Widespread heterogeneous neuronal loss across the cerebral cortex in Huntington's disease.

PubMed

Nana, Alissa L; Kim, Eric H; Thu, Doris C V; Oorschot, Dorothy E; Tippett, Lynette J; Hogg, Virginia M; Synek, Beth J; Roxburgh, Richard; Waldvogel, Henry J; Faull, Richard L M

2014-01-01

Huntington's disease is an autosomal dominant neurodegenerative disease characterized by neuronal degeneration in the basal ganglia and cerebral cortex, and a variable symptom profile. Although progressive striatal degeneration is known to occur and is related to symptom profile, little is known about the cellular basis of symptom heterogeneity across the entire cerebral cortex. To investigate this, we have undertaken a double blind study using unbiased stereological cell counting techniques to determine the pattern of cell loss in six representative cortical regions from the frontal, parietal, temporal, and occipital lobes in the brains of 14 Huntington's disease cases and 15 controls. The results clearly demonstrate a widespread loss of total neurons and pyramidal cells across all cortical regions studied, except for the primary visual cortex. Importantly, the results show that cell loss is remarkably variable both within and between Huntington's disease cases. The results also show that neuronal loss in the primary sensory and secondary visual cortices relate to Huntington's disease motor symptom profiles, and neuronal loss across the associational cortices in the frontal, parietal and temporal lobes is related to both Huntington's disease motor and to mood symptom profiles. This finding considerably extends a previous study (Thu et al., Brain, 2010; 133:1094-1110) which showed that neuronal loss in the primary motor cortex was related specifically to the motor symptom profiles while neuronal loss in the anterior cingulate cortex was related specifically to mood symptom profiles. The extent of cortical cell loss in the current study was generally related to the striatal neuropathological grade, but not to CAG repeat length on the HTT gene. Overall our findings show that Huntington's disease is characterized by a heterogeneous pattern of neuronal cell loss across the entire cerebrum which varies with symptom profile.

Exome sequencing identifies SUCO mutations in mesial temporal lobe epilepsy.

PubMed

Sha, Zhiqiang; Sha, Longze; Li, Wenting; Dou, Wanchen; Shen, Yan; Wu, Liwen; Xu, Qi

2015-03-30

Mesial temporal lobe epilepsy (mTLE) is the main type and most common medically intractable form of epilepsy. Severity of disease-based stratified samples may help identify new disease-associated mutant genes. We analyzed mRNA expression profiles from patient hippocampal tissue. Three of the seven patients had severe mTLE with generalized-onset convulsions and consciousness loss that occurred over many years. We found that compared with other groups, patients with severe mTLE were classified into a distinct group. Whole-exome sequencing and Sanger sequencing validation in all seven patients identified three novel SUN domain-containing ossification factor (SUCO) mutations in severely affected patients. Furthermore, SUCO knock down significantly reduced dendritic length in vitro. Our results indicate that mTLE defects may affect neuronal development, and suggest that neurons have abnormal development due to lack of SUCO, which may be a generalized-onset epilepsy-related gene. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Is there a creative functional paradoxical facilitation in juvenile myoclonic epilepsy?

PubMed

Senf, Philine; Scheuren, Lena; Holtkamp, Martin

2016-09-01

In patients with juvenile myoclonic epilepsy (JME), a specific personality profile suggestive of frontal lobe dysfunctions has been described. From a neurobiological point of view, the frontal lobe seems to be crucial for creative processes, although the exact role remains unclear. The theory of creative paradoxical functional facilitation (PFF) assumes that disinhibited frontal lobe function can enhance creative abilities. The aim of the current study was to explore our hypothesis that JME is associated with higher artistic creativity based on the theory of PFF. We assessed 25 patients with JME aged 18 to 40years in regard to neuropsychological creativity testing. Results were compared with those of 25 age-, sex-, and level of education-matched healthy control subjects (HC) and patients with temporal lobe epilepsy (TLE). Creative abilities were assessed using two validated and standardized tests: 1) nonverbal: the incomplete figure task of Torrance Test of Creative Thinking and 2) verbal: verbal creativity test. Additionally, a basic assessment of fluid intelligence (test for problem solving) and frontal lobe function (trail-making test) was administered to all participants. Verbal creativity was impaired in both groups with epilepsy compared with that in HC (specific score: JME vs. HC, p=0.008; TLE vs. HC, p=0.003). In regard to nonverbal creative abilities, both groups with epilepsy exhibited fair performance. Level of fluid intelligence was even in all groups (p=0.433). Only patients with JME showed deficits in the frontal lobe test of psychomotor speed (time in seconds: 67.7 JME vs. 54.6 TLE vs. 52.8 HC; p=0.045). Overall, our study did not reveal increased creativity in JME. The current findings provide insights into creative abilities in two different epilepsy syndromes. Knowledge on specific neuropsychological strengths or deficits in patients with epilepsy may be useful for treatment or counseling. Copyright © 2016 Elsevier Inc. All rights reserved.

Highly tissue specific expression of Sphinx supports its male courtship related role in Drosophila melanogaster.

PubMed

Chen, Ying; Dai, Hongzheng; Chen, Sidi; Zhang, Luoying; Long, Manyuan

2011-04-26

Sphinx is a lineage-specific non-coding RNA gene involved in regulating courtship behavior in Drosophila melanogaster. The 5' flanking region of the gene is conserved across Drosophila species, with the proximal 300 bp being conserved out to D. virilis and a further 600 bp region being conserved amongst the melanogaster subgroup (D. melanogaster, D. simulans, D. sechellia, D. yakuba, and D. erecta). Using a green fluorescence protein transformation system, we demonstrated that a 253 bp region of the highly conserved segment was sufficient to drive sphinx expression in male accessory gland. GFP signals were also observed in brain, wing hairs and leg bristles. An additional ∼800 bp upstream region was able to enhance expression specifically in proboscis, suggesting the existence of enhancer elements. Using anti-GFP staining, we identified putative sphinx expression signal in the brain antennal lobe and inner antennocerebral tract, suggesting that sphinx might be involved in olfactory neuron mediated regulation of male courtship behavior. Whole genome expression profiling of the sphinx knockout mutation identified significant up-regulated gene categories related to accessory gland protein function and odor perception, suggesting sphinx might be a negative regulator of its target genes.

Highly Tissue Specific Expression of Sphinx Supports Its Male Courtship Related Role in Drosophila melanogaster

PubMed Central

Chen, Sidi; Zhang, Luoying; Long, Manyuan

2011-01-01

Sphinx is a lineage-specific non-coding RNA gene involved in regulating courtship behavior in Drosophila melanogaster. The 5′ flanking region of the gene is conserved across Drosophila species, with the proximal 300 bp being conserved out to D. virilis and a further 600 bp region being conserved amongst the melanogaster subgroup (D. melanogaster, D. simulans, D. sechellia, D. yakuba, and D. erecta). Using a green fluorescence protein transformation system, we demonstrated that a 253 bp region of the highly conserved segment was sufficient to drive sphinx expression in male accessory gland. GFP signals were also observed in brain, wing hairs and leg bristles. An additional ∼800 bp upstream region was able to enhance expression specifically in proboscis, suggesting the existence of enhancer elements. Using anti-GFP staining, we identified putative sphinx expression signal in the brain antennal lobe and inner antennocerebral tract, suggesting that sphinx might be involved in olfactory neuron mediated regulation of male courtship behavior. Whole genome expression profiling of the sphinx knockout mutation identified significant up-regulated gene categories related to accessory gland protein function and odor perception, suggesting sphinx might be a negative regulator of its target genes. PMID:21541324

Computed Tomographic Measures of Pulmonary Vascular Morphology in Smokers and Their Clinical Implications

PubMed Central

Estépar, Raúl San José; Kinney, Gregory L.; Black-Shinn, Jennifer L.; Bowler, Russell P.; Kindlmann, Gordon L.; Ross, James C.; Kikinis, Ron; Han, MeiLan K.; Come, Carolyn E.; Diaz, Alejandro A.; Cho, Michael H.; Hersh, Craig P.; Schroeder, Joyce D.; Reilly, John J.; Lynch, David A.; Crapo, James D.; Wells, J. Michael; Dransfield, Mark T.; Hokanson, John E.

2013-01-01

Rationale: Angiographic investigation suggests that pulmonary vascular remodeling in smokers is characterized by distal pruning of the blood vessels. Objectives: Using volumetric computed tomography scans of the chest we sought to quantitatively evaluate this process and assess its clinical associations. Methods: Pulmonary vessels were automatically identified, segmented, and measured. Total blood vessel volume (TBV) and the aggregate vessel volume for vessels less than 5 mm2 (BV5) were calculated for all lobes. The lobe-specific BV5 measures were normalized to the TBV of that lobe and the nonvascular tissue volume (BV5/TissueV) to calculate lobe-specific BV5/TBV and BV5/TissueV ratios. Densitometric measures of emphysema were obtained using a Hounsfield unit threshold of −950 (%LAA-950). Measures of chronic obstructive pulmonary disease severity included single breath measures of diffusing capacity of carbon monoxide, oxygen saturation, the 6-minute-walk distance, St George’s Respiratory Questionnaire total score (SGRQ), and the body mass index, airflow obstruction, dyspnea, and exercise capacity (BODE) index. Measurements and Main Results: The %LAA-950 was inversely related to all calculated vascular ratios. In multivariate models including age, sex, and %LAA-950, lobe-specific measurements of BV5/TBV were directly related to resting oxygen saturation and inversely associated with both the SGRQ and BODE scores. In similar multivariate adjustment lobe-specific BV5/TissueV ratios were inversely related to resting oxygen saturation, diffusing capacity of carbon monoxide, 6-minute-walk distance, and directly related to the SGRQ and BODE. Conclusions: Smoking-related chronic obstructive pulmonary disease is characterized by distal pruning of the small blood vessels (<5 mm2) and loss of tissue in excess of the vasculature. The magnitude of these changes predicts the clinical severity of disease. PMID:23656466

Biosynthesis of truncated N-linked oligosaccharides results from non-orthologous hexosaminidase-mediated mechanisms in nematodes, plants, and insects.

PubMed

Gutternigg, Martin; Kretschmer-Lubich, Dorothea; Paschinger, Katharina; Rendić, Dubravko; Hader, Josef; Geier, Petra; Ranftl, Ramona; Jantsch, Verena; Lochnit, Günter; Wilson, Iain B H

2007-09-21

In many invertebrates and plants, the N-glycosylation profile is dominated by truncated paucimannosidic N-glycans, i.e. glycans consisting of a simple trimannosylchitobiosyl core often modified by core fucose residues. Even though they lack antennal N-acetylglucosamine residues, the biosynthesis of these glycans requires the sequential action of GlcNAc transferase I, Golgi mannosidase II, and, finally, beta-N-acetylglucosaminidases. In Drosophila, the recently characterized enzyme encoded by the fused lobes (fdl) gene specifically removes the non-reducing N-acetylglucosamine residue from the alpha1,3-antenna of N-glycans. In the present study, we examined the products of five beta-N-acetylhexosaminidase genes from Caenorhabditis elegans (hex-1 to hex-5, corresponding to reading frames T14F9.3, C14C11.3, Y39A1C.4, Y51F10.5, and Y70D2A.2) in addition to three from Arabidopsis thaliana (AtHEX1, AtHEX2, and AtHEX3, corresponding to reading frames At1g65590, At3g55260, and At1g05590). Based on homology, the Caenorhabditis HEX-1 and all three Arabidopsis enzymes are members of the same sub-family as the aforementioned Drosophila fused lobes enzyme but either act as chitotriosidases or non-specifically remove N-acetylglucosamine from both N-glycan antennae. The other four Caenorhabditis enzymes are members of a distinct sub-family; nevertheless, two of these enzymes displayed the same alpha1,3-antennal specificity as the fused lobes enzyme. Furthermore, a deletion of part of the Caenorhabditis hex-2 gene drastically reduces the native N-glycan-specific hexosaminidase activity in mutant worm extracts and results in a shift in the N-glycan profile, which is a demonstration of its in vivo enzymatic relevance. Based on these data, it is hypothesized that the genetic origin of paucimannosidic glycans in nematodes, plants, and insects involves highly divergent members of the same hexosaminidase gene family.

The Pliocene-Quaternary tectonic evolution of the Cilicia and Adana basins, eastern Mediterranean: Special reference to the development of the Kozan Fault zone

NASA Astrophysics Data System (ADS)

Aksu, A. E.; Walsh-Kennedy, S.; Hall, J.; Hiscott, R. N.; Yaltırak, C.; Akhun, S. D.; Çifçi, G.

2014-05-01

A grid of high-resolution multi-channel seismic reflection profiles allows the detailed mapping of the Kozan Fault zone in the Cilicia and Adana basins. The zone is delineated by an arcuate zone consisting of several ENE-WSW and NNE-SSW striking, closely-spaced high-angle extensional faults which define an ~ 300 km long and 15-20 km-wide “lazy-S” shaped structure along the southeastern fringes of the Taurus Mountain and along the northwestern margins of the Cilicia and Adana basins. In the Cilicia Basin the zone consists of several high-angle faults which exhibit small dip separations on the M-reflector and have tip points situated mainly in the lower and middle portion of the Pliocene-Quaternary succession. In the Adana Basin a family of northeast-striking and southeast dipping extensional faults occurs along the western and northwestern margin of the basin. The faults cut down with relatively steep dip into the ~ 700 ms thick Tortonian and older Miocene successions. Multi-channel seismic reflection profiles show that three prominent seismic markers divide the uppermost Messinian-Recent successions in the Cilicia and Adana basins into three subunits: the uppermost Messinian-Lower Pliocene subunit 1C between the M- and A-reflectors, the Upper Pliocene subunit 1B between the A- and P-reflectors and the Quaternary subunit 1A between the P-reflector and the seafloor. Prominent delta lobes are identified in the seismic profiles that are correlated with the ancestral Göksu River. Isopach maps constructed using depth-converted seismic reflection profiles show clear temporal and spatial variations of the delta lobes of the Göksu River during the latest Messinian-Recent. The uppermost Messinian-Lower Pliocene delta lobe is situated furthest to the northeast whereas the youngest Quaternary lobe is situated furthest to the southwest, with 20-35 km displacement along a northeast-southwest line, which suggests a conservative estimate of 0.43-0.75 cm/yr sinistral slip for the Kozan Fault zone.

Gene expression profile differences in left and right liver lobes from mid-gestation fetal baboons: a cautionary tale

PubMed Central

Cox, Laura A; Schlabritz-Loutsevitch, Natalia; Hubbard, Gene B; Nijland, Mark J; McDonald, Thomas J; Nathanielsz, Peter W

2006-01-01

Interpretation of gene array data presents many potential pitfalls in adult tissues. Gene array techniques applied to fetal tissues present additional confounding pitfalls. The left lobe of the fetal liver is supplied with blood containing more oxygen than the right lobe. Since synthetic activity and cell function are oxygen dependent, we hypothesized major differences in mRNA expression between the fetal right and left liver lobes. Our aim was to demonstrate the need to evaluate RNA samples from both lobes. We performed whole genome expression profiling on left and right liver lobe RNA from six 90-day gestation baboon fetuses (term 180 days). Comparing right with left, we found 875 differentially expressed genes – 312 genes were up-regulated and 563 down-regulated. Pathways for damaged DNA binding, endonuclease activity, interleukin binding and receptor activity were up-regulated in right lobe; ontological pathways related to cell signalling, cell organization, cell biogenesis, development, intracellular transport, phospholipid metabolism, protein biosynthesis, protein localization, protein metabolism, translational regulation and vesicle mediated transport were down-regulated in right lobe. Molecular pathway analysis showed down-regulation of pathways related to heat shock protein binding, ion channel and transporter activities, oxygen binding and transporter activities, translation initiation and translation regulator activities. Genes involved in amino acid biosynthesis, lipid biosynthesis and oxygen transport were also differentially expressed. This is the first demonstration of RNA differences between the two lobes of the fetal liver. The data support the argument that a complete interpretation of gene expression in the developing liver requires data from both lobes. PMID:16484296

Attention improves memory by suppressing spiking-neuron activity in the human anterior temporal lobe.

PubMed

Wittig, John H; Jang, Anthony I; Cocjin, John B; Inati, Sara K; Zaghloul, Kareem A

2018-06-01

We identify a memory-specific attention mechanism in the human anterior temporal lobe, an area implicated in semantic processing and episodic memory formation. Spiking neuron activity is suppressed and becomes more reliable in preparation for verbal memory formation. Intracranial electroencephalography signals implicate this region as a source of executive control for attentional selection. Consistent with this interpretation, its surgical removal causes significant memory impairment for attended words relative to unattended words.

Temporal Lobe and “Default” Hemodynamic Brain Modes Discriminate Between Schizophrenia and Bipolar Disorder

PubMed Central

Calhoun, Vince D.; Maciejewski, Paul K.; Pearlson, Godfrey D.; Kiehl, Kent A.

2009-01-01

Schizophrenia and bipolar disorder are currently diagnosed on the basis of psychiatric symptoms and longitudinal course. The determination of a reliable, biologically-based diagnostic indicator of these diseases (a biomarker) could provide the groundwork for developing more rigorous tools for differential diagnosis and treatment assignment. Recently, methods have been used to identify distinct sets of brain regions or “spatial modes” exhibiting temporally coherent brain activity. Using functional magnetic resonance imaging (fMRI) data and a multivariate analysis method, independent component analysis, we combined the temporal lobe and the default modes to discriminate subjects with bipolar disorder, chronic schizophrenia, and healthy controls. Temporal lobe and default mode networks were reliably identified in all participants. Classification results on an independent set of individuals revealed an average sensitivity and specificity of 90 and 95%, respectively. The use of coherent brain networks such as the temporal lobe and default mode networks may provide a more reliable measure of disease state than task-correlated fMRI activity. A combination of two such hemodynamic brain networks shows promise as a biomarker for schizophrenia and bipolar disorder. PMID:17894392

Temporal lobe and "default" hemodynamic brain modes discriminate between schizophrenia and bipolar disorder.

PubMed

Calhoun, Vince D; Maciejewski, Paul K; Pearlson, Godfrey D; Kiehl, Kent A

2008-11-01

Schizophrenia and bipolar disorder are currently diagnosed on the basis of psychiatric symptoms and longitudinal course. The determination of a reliable, biologically-based diagnostic indicator of these diseases (a biomarker) could provide the groundwork for developing more rigorous tools for differential diagnosis and treatment assignment. Recently, methods have been used to identify distinct sets of brain regions or "spatial modes" exhibiting temporally coherent brain activity. Using functional magnetic resonance imaging (fMRI) data and a multivariate analysis method, independent component analysis, we combined the temporal lobe and the default modes to discriminate subjects with bipolar disorder, chronic schizophrenia, and healthy controls. Temporal lobe and default mode networks were reliably identified in all participants. Classification results on an independent set of individuals revealed an average sensitivity and specificity of 90 and 95%, respectively. The use of coherent brain networks such as the temporal lobe and default mode networks may provide a more reliable measure of disease state than task-correlated fMRI activity. A combination of two such hemodynamic brain networks shows promise as a biomarker for schizophrenia and bipolar disorder.

Wideband Low Side Lobe Aperture Coupled Patch Phased Array Antennas

NASA Astrophysics Data System (ADS)

Poduval, Dhruva

Low profile printed antenna arrays with wide bandwidth, high gain, and low Side Lobe Level (SLL) are in great demand for current and future commercial and military communication systems and radar. Aperture coupled patch antennas have been proposed to obtain wide impedance bandwidths in the past. Aperture coupling is preferred particularly for phased arrays because of their advantage of integration to other active devices and circuits, e.g. phase shifters, power amplifiers, low noise amplifiers, mixers etc. However, when designing such arrays, the interplay between array performance characteristics, such as gain, side lobe level, back lobe level, mutual coupling etc. must be understood and optimized under multiple design constraints, e.g. substrate material properties and thicknesses, element to element spacing, and feed lines and their orientation and arrangements with respect to the antenna elements. The focus of this thesis is to investigate, design, and develop an aperture coupled patch array with wide operating bandwidth (30%), high gain (17.5 dBi), low side lobe level (20 dB), and high Forward to Backward (F/B) ratio (21.8 dB). The target frequency range is 2.4 to 3 GHz given its wide application in WLAN, LTE (Long Term Evolution) and other communication systems. Notwithstanding that the design concept can very well be adapted at other frequencies. Specifically, a 16 element, 4 by 4 planar microstrip patch array is designed using HFSS and experimentally developed and tested. Starting from mutual coupling minimization a corporate feeding scheme is designed to achieve the needed performance. To reduce the SLL the corporate feeding network is redesigned to obtain a specific amplitude taper. Studies are conducted to determine the optimum location for a metallic reflector under the feed line to improve the F/B. An experimental prototype of the antenna was built and tested validating and demonstrating the performance levels expected from simulation predictions. Finally, simulated beam scanning in several angles of the array is shown considering specific phases for each antenna element in the array.

Long-term consolidation of declarative memory: insight from temporal lobe epilepsy.

PubMed

Tramoni, Eve; Felician, Olivier; Barbeau, Emmanuel J; Guedj, Eric; Guye, Maxime; Bartolomei, Fabrice; Ceccaldi, Mathieu

2011-03-01

Several experiments carried out with a subset of patients with temporal lobe epilepsy have demonstrated normal memory performance at standard delays of recall (i.e. minutes to hours) but impaired performance over longer delays (i.e. days or weeks), suggesting altered long-term consolidation mechanisms. These mechanisms were specifically investigated in a group of five adult-onset pharmaco-sensitive patients with temporal lobe epilepsy, exhibiting severe episodic memory complaints despite normal performance at standardized memory assessment. In a first experiment, the magnitude of autobiographical memory loss was evaluated using retrograde personal memory tasks based on verbal and visual cues. In both conditions, results showed an unusual U-shaped pattern of personal memory impairment, encompassing most of the patients' life, sparing however, periods of the childhood, early adulthood and past several weeks. This profile was suggestive of a long-term consolidation impairment of personal episodes, adequately consolidated over 'short-term' delays but gradually forgotten thereafter. Therefore, in a subsequent experiment, patients were submitted to a protocol specifically devised to investigate short and long-term consolidation of contextually-bound experiences (episodic memory) and context-free information (semantic knowledge and single-items). In the short term (1 h), performance at both contextually-free and contextually-bound memory tasks was intact. After a 6-week delay, however, contextually-bound memory performance was impaired while contextually-free memory performance remained preserved. This effect was independent of task difficulty and the modality of retrieval (recall and recognition). Neuroimaging studies revealed the presence of mild metabolic changes within medial temporal lobe structures. Taken together, these results show the existence of different consolidation systems within declarative memory. They suggest that mild medial temporal lobe dysfunction can impede the building and stabilization of episodic memories but leaves long-term semantic and single-items mnemonic traces intact.

Tumours of Deep Lobe of Parotid Gland: Our Experience.

PubMed

Dass, Arjun; Gupta, Nitin; Singhal, S K; Verma, Hitesh

2015-12-01

Parotidectomy surgeries are being routinely performed by ENT surgeons nowadays. Parotid tumours can present with a variety of manifestations ranging from a barely noticeable mass to a large tumour with facial paralysis. Most benign parotid tumours are located in the superficial lobe though rarely deep lobe may also be involved, while malignant tumours are generally seen to involve both the lobes of the gland. We present clinico-radiological-pathological profile of 25 patients who underwent parotid surgeries for tumours involving deep lobe alone or the whole gland, and were operated at our institute during the period from January 2011 to December 2012. This study was a retroprospective observational analysis with the aim of analyzing the epidemiology, radiological, surgical and histopathological profile of these patients. Among 25 patients who underwent parotid surgeries, 17 patients underwent total conservative parotidectomy, while 5 patients underwent radical parotidectomy. In 3 patients, extended radical parotidectomy was performed. We also report the complications and follow-up of these patients. We concluded that fine needle aspiration cytology (FNAC) findings and final histopathological report may not always correlate.

Low-Profile, Dual-Wavelength, Dual-Polarized Antenna

NASA Technical Reports Server (NTRS)

Carswell, James R.

2010-01-01

A single-aperture, low-profile antenna design has been developed that supports dual-polarization and simultaneous operation at two wavelengths. It realizes multiple beams in the elevation plane, and supports radiometric, radar, and conical scanning applications. This antenna consists of multiple azimuth sticks, with each stick being a multilayer, hybrid design. Each stick forms the h-plane pattern of the C and Ku-band vertically and horizontally polarized antenna beams. By combining several azimuth sticks together, the elevation beam is formed. With a separate transceiver for each stick, the transmit phase and amplitude of each stick can be controlled to synthesize a beam at a specific incidence angle and to realize a particular side-lobe pattern. By changing the transmit phase distribution through the transceivers, the transmit antenna beam can be steered to different incidence angles. By controlling the amplitude distribution, different side lobe patterns and efficiencies can be realized. The receive beams are formed using digital beam synthesis techniques, resulting in very little loss in the receive path, thus enabling a very-low loss receive antenna to support passive measurements.

A Numerical Model of Hercules A by Magnetic Tower

NASA Astrophysics Data System (ADS)

Nakamura, Masanori; Tregillis, I. L.; Li, H.; Li, S.

2009-01-01

We apply magnetohydrodynamic (MHD) modeling to the radio galaxy Hercules A for investigating the jet-driven shock, jet/lobe transition, wiggling, and magnetic field distribution associated with this source. The model consists of magnetic tower jets in a galaxy cluster environment. The profile of underlying ambient gas plays an important role in jet-lobe morphology. The balance between the magnetic pressure generated by axial current and the ambient gas pressure can determine the lobe radius. The jet body is confined jointly by the external pressure and gravity inside the cluster core radius, while outside this radius it expands radially to form fat lobes in a steeply decreasing ambient thermal pressure gradient. The current-carrying jets are responsible for generating a strong, tightly wound helical magnetic field. This magnetic configuration will be unstable against the current-driven kink mode and it visibly grows beyond the cluster core radius where a separation between the jet forward and return currents occurs. The reversed pinch profile of global magnetic field associated with the jet and lobes produces projected magnetic-vector distributions aligned with the jet flow and the lobe edge. AGN-driven shock powered by the expanding magnetic tower jet surrounds the jet/lobe structure and heats the ambient ICM. The lobes expand subsonically; no obvious hot spots are produced at the heads of lobes. Several key features in our MHD modeling may be qualitatively supported by the observations of Hercules A. This work was carried out under the auspices of the National Nuclear Security Administration of the U.S. Department of Energy at Los Alamos National Laboratory under Contract No. DE-AC52-06NA25396. It was supported by the Laboratory Directed Research and Development Program at LANL and by IGPP at LANL.

Pheromone-sensitive glomeruli in the primary olfactory centre of ants.

PubMed

Yamagata, Nobuhiro; Nishino, Hiroshi; Mizunami, Makoto

2006-09-07

Tremendous evolutional success and the ecological dominance of social insects, including ants, termites and social bees, are due to their efficient social organizations and their underlying communication systems. Functional division into reproductive and sterile castes, cooperation in defending the nest, rearing the young and gathering food are all regulated by communication by means of various kinds of pheromones. No brain structures specifically involved in the processing of non-sexual pheromone have been physiologically identified in any social insects. By use of intracellular recording and staining techniques, we studied responses of projection neurons of the antennal lobe (primary olfactory centre) of ants to alarm pheromone, which plays predominant roles in colony defence. Among 23 alarm pheromone-sensitive projection neurons recorded and stained in this study, eight were uniglomerular projection neurons with dendrites in one glomerulus, a structural unit of the antennal lobe, and the remaining 15 were multiglomerular projection neurons with dendrites in multiple glomeruli. Notably, all alarm pheromone-sensitive uniglomerular projection neurons had dendrites in one of five 'alarm pheromone-sensitive (AS)' glomeruli that form a cluster in the dorsalmost part of the antennal lobe. All alarm pheromone-sensitive multiglomerular projection neurons had dendrites in some of the AS glomeruli as well as in glomeruli in the anterodorsal area of the antennal lobe. The results suggest that components of alarm pheromone are processed in a specific cluster of glomeruli in the antennal lobe of ants.

1H-MRS in autism spectrum disorders: a systematic meta-analysis.

PubMed

Ipser, Jonathan C; Syal, Supriya; Bentley, Judy; Adnams, Colleen M; Steyn, Bennie; Stein, Dan J

2012-09-01

We conducted a systematic review and meta-analysis of proton magnetic resonance spectroscopy (1H-MRS) studies comparing autism spectrum disorder (ASD) patients with healthy controls, with the aim of profiling ASD-associated changes in the metabolites N-acetyl-aspartate (NAA) and Creatine (Cr). Meta-regression models of NAA and Cr levels were employed, using data from 20 eligible studies (N = 852), to investigate age-dependent differences in both global brain and region-specific metabolite levels, while controlling for measurement method (Cr-ratio versus absolute concentrations). Decreased NAA concentrations that were specific to children were found for whole-brain grey and white matter. In addition, a significant decrease in NAA was evident across age categories in the parietal cortex, the cerebellum, and the anterior cingulate cortex. Higher levels of Cr were observed for ASD adults than children in global grey matter, with specific increases for adults in the temporal lobe and decreased Cr in the occipital lobe in children. No differences were found for either NAA or Cr in the frontal lobes. These data provide some evidence that ASD is characterized by age-dependent fluctuations in metabolite levels across the whole brain and at the level of specific regions thought to underlie ASD-associated behavioural and affective deficits. Differences in Cr as a function of age and brain region suggests caution in the interpretation of Cr-based ratio measures of metabolites. Despite efforts to control for sources of heterogeneity, considerable variability in metabolite levels was observed in frontal and temporal regions, warranting further investigation.

Depositional patterns of the Mississippi Fan surface: Evidence from GLORIA II and high-resolution seismic profiles

USGS Publications Warehouse

Twichell, David C.; Kenyon, Neil H.; Parson, Lindsay M.; McGregor, Bonnie A.

1991-01-01

GLORIA long-range side-scan sonar imagery and 3.5-kHz seismic-reflection profiles depict a series of nine elongate deposits with generally high-backscatter surfaces covering most of the latest fanlobe sequence of the Mississippi Fan in the eastern Gulf of Mexico. The youngest deposit is a “slump” that covers a 250 by 100 km area of the middle and upper fan. The remaining mapped deposits, termed depositional lobes, are long (as much as 200 km) and relatively thin (less than 35 m thick) bodies. Small channels and lineations on the surface of many of these depositional lobes radiate from a single, larger main channel that is the conduit through which sediment has been supplied to these surficial deposits on the fan. The 3.5-kHz profiles show that adjacent depositional lobes overlap one another rather than interfingering, indicating that only one lobe was an active site of deposition at a time. Shifting of the depositional sites appears to be caused by both aggradation and avulsion. The chronology developed from the overlapping relations indicates the oldest of the mapped depositional lobes are on the lowermost fan, and the youngest are further up the fan. Depositional lobes on the lower fan consist of a series of smaller, elongate features with high-backscatter surfaces (540 km in length) located at the ends of previously unrecognized small channels (< 5 m deep). These small channels extend as much as 120 km from the main channel. Small channelized turbidity currents and/or debris flows, sand flows, or mud flows appear to be the dominant transport process constructing these depositional lobes. Channelized flow is an important mechanism for transporting sediment away from the main channel on this fan and the resulting facies created by these small flows are laterally discontinuous.

Widespread changes in network activity allow non-invasive detection of mesial temporal lobe seizures

PubMed Central

Zepeda, Rodrigo; Cole, Andrew J.; Cash, Sydney S.

2016-01-01

Abstract Decades of experience with intracranial recordings in patients with epilepsy have demonstrated that seizures can occur in deep cortical regions such as the mesial temporal lobes without showing any obvious signs of seizure activity on scalp electroencephalogram. Predicated on the idea that these seizures are purely focal, currently, the only way to detect these ‘scalp-negative seizures’ is with intracranial recordings. However, intracranial recordings are only rarely performed in patients with epilepsy, and are almost never performed outside of the context of epilepsy. As such, little is known about scalp-negative seizures and their role in the natural history of epilepsy, their effect on cognitive function, and their association with other neurological diseases. Here, we developed a novel approach to non-invasively identify scalp-negative seizures arising from the mesial temporal lobe based on scalp electroencephalogram network connectivity measures. We identified 25 scalp-negative mesial temporal lobe seizures in 10 patients and obtained control records from an additional 13 patients, all of whom underwent recordings with foramen ovale electrodes and scalp electroencephalogram. Scalp data from these records were used to train a scalp-negative seizure detector, which consisted of a pair of logistic regression classifiers that used scalp electroencephalogram coherence properties as input features. On cross-validation performance, this detector correctly identified scalp-negative seizures in 40% of patients, and correctly identified the side of seizure onset for each seizure detected. In comparison, routine clinical interpretation of these scalp electroencephalograms failed to identify any of the scalp-negative seizures. Among the patients in whom the detector raised seizure alarms, 80% had scalp-negative mesial temporal lobe seizures. The detector had a false alarm rate of only 0.31 per day and a positive predictive value of 75%. Of the 13 control patients, false seizure alarms were raised in only one patient. The fact that our detector specifically recognizes focal mesial temporal lobe seizures based on scalp electroencephalogram coherence features, lends weight to the hypothesis that even focal seizures are a network phenomenon that involve widespread neural connectivity. Our scalp-negative seizure detector has clear clinical utility in patients with temporal lobe epilepsy, and its potential easily translates to other neurological disorders, such as Alzheimer’s disease, in which occult mesial temporal lobe seizures are suspected to play a significant role. Importantly, our work establishes a novel approach of using computational approaches to non-invasively detect deep seizure activity, without the need for invasive intracranial recordings. PMID:27474219

Brain structural differences associated with the behavioural phenotype in children with Williams syndrome.

PubMed

Campbell, Linda E; Daly, Eileen; Toal, Fiona; Stevens, Angela; Azuma, Rayna; Karmiloff-Smith, Annette; Murphy, Declan G M; Murphy, Kieran C

2009-03-03

We investigated structural brain morphology of intellectually disabled children with Williams (WS) syndrome and its relationship to the behavioural phenotype. We compared the neuroanatomy of 15 children (mean age:13+/-2) with WS and 15 age/gender-matched healthy children using a manual region-of-interest analysis to measure bulk (white+grey) tissue volumes and unbiased fully-automated voxel-based morphometry to assess differences in grey/white matter throughout the brain. Ratings of abnormal behaviours were correlated with brain structure. Compared to controls, the brains of children with WS had a decreased volume of the right parieto-occipital regions and basal ganglia. We identified reductions of grey matter of the parieto-occipital regions, left putamen/globus pallidus and thalamus; and in white matter of the basal ganglia and right posterior cingulate gyrus. In contrast, significant increases of grey matter were identified in the frontal lobes, anterior cingulate gyrus, left temporal lobe, and of white matter bilaterally in the anterior cingulate. Inattention in WS was correlated with volumetric differences in the frontal lobes, caudate nucleus and cerebellum, and hyperactivity was related to differences in the left temporal and parietal lobes and cerebellum. Finally, ratings of peer problems were related to differences in the temporal lobes, right basal ganglia and frontal lobe. In one of the first studies of brain structure in intellectually disabled children with WS using voxel-based morphometry, our findings suggest that this group has specific differences in grey/white matter morphology. In addition, it was found that structural differences were correlated to ratings of inattention, hyperactivity and peer problems in children with WS.

A Novel RNA Editing Sensor Tool and a Specific Agonist Determine Neuronal Protein Expression of RNA-Edited Glycine Receptors and Identify a Genomic APOBEC1 Dimorphism as a New Genetic Risk Factor of Epilepsy

PubMed Central

Kankowski, Svenja; Förstera, Benjamin; Winkelmann, Aline; Knauff, Pina; Wanker, Erich E.; You, Xintian A.; Semtner, Marcus; Hetsch, Florian; Meier, Jochen C.

2018-01-01

C-to-U RNA editing of glycine receptors (GlyR) can play an important role in disease progression of temporal lobe epilepsy (TLE) as it may contribute in a neuron type-specific way to neuropsychiatric symptoms of the disease. It is therefore necessary to develop tools that allow identification of neuron types that express RNA-edited GlyR protein. In this study, we identify NH4 as agonist of C-to-U RNA edited GlyRs. Furthermore, we generated a new molecular C-to-U RNA editing sensor tool that detects Apobec-1- dependent RNA editing in HEPG2 cells and rat primary hippocampal neurons. Using this sensor combined with NH4 application, we were able to identify C-to-U RNA editing-competent neurons and expression of C-to-U RNA-edited GlyR protein in neurons. Bioinformatic analysis of 1,000 Genome Project Phase 3 allele frequencies coding for human Apobec-1 80M and 80I variants showed differences between populations, and the results revealed a preference of the 80I variant to generate RNA-edited GlyR protein. Finally, we established a new PCR-based restriction fragment length polymorphism (RFLP) approach to profile mRNA expression with regard to the genetic APOBEC1 dimorphism of patients with intractable temporal lobe epilepsy (iTLE) and found that the patients fall into two groups. Patients with expression of the Apobec-1 80I variant mostly suffered from simple or complex partial seizures, whereas patients with 80M expression exhibited secondarily generalized seizure activity. Thus, our method allows the characterization of Apobec-1 80M and 80l variants in the brain and provides a new way to epidemiologically and semiologically classify iTLE according to the two different APOBEC1 alleles. Together, these results demonstrate Apobec-1-dependent expression of RNA-edited GlyR protein in neurons and identify the APOBEC1 80I/M-coding alleles as new genetic risk factors for iTLE patients. PMID:29375302

Amino acid metabolic processes in the temporal lobes assessed by proton magnetic resonance spectroscopy (1H MRS) in children with Down syndrome.

PubMed

Śmigielska-Kuzia, Joanna; Boćkowski, Leszek; Sobaniec, Wojciech; Kułak, Wojciech; Sendrowski, Krzysztof

2010-01-01

Down syndrome (DS), or trisomy 21, is one of the most common autosomal mutations. The overexpression of the β-amyloid precursor protein gene, located on chromosome 21, causes an increased production of the specific amyloid. The current study is a continuation of our earlier investigations relating to the profile of metabolic changes in the frontal lobes of DS patients as assessed by proton magnetic resonance spectroscopy ((1)H MRS). The aims of the study were the morphological assessment of the brain using magnetic resonance imaging (MRI) and the evaluation of metabolic disorders of the temporal lobes using (1)H MRS in DS children. The study group included 20 children with DS aged 3-15 years and treated in the Department of Pediatric Neurology and Rehabilitation, Medical University of Białystok. The control group included healthy children (n = 20). MRI scans of the heads of DS children were performed using a 1.5 T MR scanner under standard conditions. (1)H MRS investigations were also carried out to assess metabolic changes in the temporal lobes. Metabolites, such as N-acetylaspartate (NAA), glutamate-glutamine complex (Glx), choline (Cho), myoinositol (mI) and γ-aminobutyric acid (GABA), were determined in both temporal lobes with reference to the internal marker creatine (Cr). Results were compared with the control group.We found a statistically significant decrease in NAA/Cr, Cho/Cr, mI/Cr and GABA/Cr ratios. The Glx/Cr ratio in both temporal lobes of DS patients did not differ from the control group. Our results indicate metabolic neurotransmitter disorders in the central nervous system in children with DS.

Primary age-related tauopathy (PART): a common pathology associated with human aging

PubMed Central

Crary, John F.; Trojanowski, John Q.; Schneider, Julie A.; Abisambra, Jose F.; Abner, Erin L.; Alafuzoff, Irina; Arnold, Steven E.; Attems, Johannes; Beach, Thomas G.; Bigio, Eileen H.; Cairns, Nigel J.; Dickson, Dennis W.; Gearing, Marla; Grinberg, Lea T.; Hof, Patrick R.; Hyman, Bradley T.; Jellinger, Kurt; Jicha, Gregory A.; Kovacs, Gabor G.; Knopman, David S.; Kofler, Julia; Kukull, Walter A.; Mackenzie, Ian R.; Masliah, Eliezer; McKee, Ann; Montine, Thomas J.; Murray, Melissa E.; Neltner, Janna H.; Santa-Maria, Ismael; Seeley, William W.; Serrano-Pozo, Alberto; Shelanski, Michael L.; Stein, Thor; Takao, Masaki; Thal, Dietmar R.; Toledo, Jonathan B.; Troncoso, Juan C.; Vonsattel, Jean Paul; White, Charles L.; Wisniewski, Thomas; Woltjer, Randall L.; Yamada, Masahito; Nelson, Peter T.

2014-01-01

We recommend a new term, “primary age-related tauopathy” (PART), to describe a pathology that is commonly observed in the brains of aged individuals. Many autopsy studies have reported brains with neurofibrillary tangles (NFT) that are indistinguishable from those of Alzheimer's disease (AD), in the absence of amyloid (Aβ) plaques. For these “NFT+/Aβ−” brains, for which formal criteria for AD neuropathologic changes are not met, the NFT are mostly restricted to structures in the medial temporal lobe, basal forebrain, brainstem, and olfactory areas (bulb and cortex). Symptoms in persons with PART usually range from normal to amnestic cognitive changes, with only a minority exhibiting profound impairment. Because cognitive impairment is often mild, existing clinicopathologic designations, such as “tangle-only dementia” and “tangle-predominant senile dementia”, are imprecise and not appropriate for most subjects. PART is almost universally detectable at autopsy among elderly individuals, yet this pathological process cannot be specifically identified pre-mortem at the present time. Improved biomarkers and tau imaging may enable diagnosis of PART in clinical settings in the future. Indeed, recent studies have identified a common biomarker profile consisting of temporal lobe atrophy and tauopathy without evidence of Aβ accumulation. For both researchers and clinicians, a revised nomenclature will raise awareness of this extremely common pathologic change while providing a conceptual foundation for future studies. Prior reports that have elucidated features of the pathologic entity we refer to as PART are discussed, and working neuropathological diagnostic criteria are proposed. PMID:25348064

Perspectives on treatment options for mesial temporal lobe epilepsy with hippocampal sclerosis.

PubMed

Palleria, Caterina; Coppola, Antonietta; Citraro, Rita; Del Gaudio, Luigi; Striano, Salvatore; De Sarro, Giovambattista; Russo, Emilio

2015-01-01

Mesial temporal lobe epilepsy associated with hippocampal sclerosis (MTLE-HS) is a syndrome that is often refractory to drug treatment. The effects on specific syndromes are not currently available from the pre-marketing clinical development of new AEDs; this does not allow the prediction of whether new drugs will be more effective in the treatment of some patients. We have reviewed all the existing literature relevant to the understanding of a potential effectiveness in MTLE-HS patients for the latest AEDs, namely brivaracetam, eslicarbazepine, lacosamide, perampanel and retigabine also including the most relevant clinical data and a brief description of their pharmacological profile. Records were identified using predefined search criteria using electronic databases (e.g., PubMed, Cochrane Library Database of Systematic Reviews). Primary peer-reviewed articles published up to the 15 June 2015 were included. All the drugs considered have the potential to be effective in the treatment of MTLE-HS; in fact, they possess proven efficacy in animal models; currently considered valuable tools for predicting drug efficacy in TLE. Furthermore, for some of these (e.g., lacosamide and eslicarbazepine) data are already available from post-marketing studies while brivaracetam acting on SV2A like levetiracetam might have the same potential effectiveness with the possibility to be more efficacious considering its ability to inhibit voltage gated sodium channels; finally, perampanel and retigabine are very effective drugs in animal models of TLE.

Passive language mapping combining real-time oscillation analysis with cortico-cortical evoked potentials for awake craniotomy.

PubMed

Tamura, Yukie; Ogawa, Hiroshi; Kapeller, Christoph; Prueckl, Robert; Takeuchi, Fumiya; Anei, Ryogo; Ritaccio, Anthony; Guger, Christoph; Kamada, Kyousuke

2016-12-01

OBJECTIVE Electrocortical stimulation (ECS) is the gold standard for functional brain mapping; however, precise functional mapping is still difficult in patients with language deficits. High gamma activity (HGA) between 80 and 140 Hz on electrocorticography is assumed to reflect localized cortical processing, whereas the cortico-cortical evoked potential (CCEP) can reflect bidirectional responses evoked by monophasic pulse stimuli to the language cortices when there is no patient cooperation. The authors propose the use of "passive" mapping by combining HGA mapping and CCEP recording without active tasks during conscious resections of brain tumors. METHODS Five patients, each with an intraaxial tumor in their dominant hemisphere, underwent conscious resection of their lesion with passive mapping. The authors performed functional localization for the receptive language area, using real-time HGA mapping, by listening passively to linguistic sounds. Furthermore, single electrical pulses were delivered to the identified receptive temporal language area to detect CCEPs in the frontal lobe. All mapping results were validated by ECS, and the sensitivity and specificity were evaluated. RESULTS Linguistic HGA mapping quickly identified the language area in the temporal lobe. Electrical stimulation by linguistic HGA mapping to the identified temporal receptive language area evoked CCEPs on the frontal lobe. The combination of linguistic HGA and frontal CCEPs needed no patient cooperation or effort. In this small case series, the sensitivity and specificity were 93.8% and 89%, respectively. CONCLUSIONS The described technique allows for simple and quick functional brain mapping with higher sensitivity and specificity than ECS mapping. The authors believe that this could improve the reliability of functional brain mapping and facilitate rational and objective operations. Passive mapping also sheds light on the underlying physiological mechanisms of language in the human brain.

Effect of Ca2+ on the promiscuous target-protein binding of calmodulin

PubMed Central

Westerlund, Annie M.

2018-01-01

Calmodulin (CaM) is a calcium sensing protein that regulates the function of a large number of proteins, thus playing a crucial part in many cell signaling pathways. CaM has the ability to bind more than 300 different target peptides in a Ca2+-dependent manner, mainly through the exposure of hydrophobic residues. How CaM can bind a large number of targets while retaining some selectivity is a fascinating open question. Here, we explore the mechanism of CaM selective promiscuity for selected target proteins. Analyzing enhanced sampling molecular dynamics simulations of Ca2+-bound and Ca2+-free CaM via spectral clustering has allowed us to identify distinct conformational states, characterized by interhelical angles, secondary structure determinants and the solvent exposure of specific residues. We searched for indicators of conformational selection by mapping solvent exposure of residues in these conformational states to contacts in structures of CaM/target peptide complexes. We thereby identified CaM states involved in various binding classes arranged along a depth binding gradient. Binding Ca2+ modifies the accessible hydrophobic surface of the two lobes and allows for deeper binding. Apo CaM indeed shows shallow binding involving predominantly polar and charged residues. Furthermore, binding to the C-terminal lobe of CaM appears selective and involves specific conformational states that can facilitate deep binding to target proteins, while binding to the N-terminal lobe appears to happen through a more flexible mechanism. Thus the long-ranged electrostatic interactions of the charged residues of the N-terminal lobe of CaM may initiate binding, while the short-ranged interactions of hydrophobic residues in the C-terminal lobe of CaM may account for selectivity. This work furthers our understanding of the mechanism of CaM binding and selectivity to different target proteins and paves the way towards a comprehensive model of CaM selectivity. PMID:29614072

Effect of Ca2+ on the promiscuous target-protein binding of calmodulin.

PubMed

Westerlund, Annie M; Delemotte, Lucie

2018-04-01

Calmodulin (CaM) is a calcium sensing protein that regulates the function of a large number of proteins, thus playing a crucial part in many cell signaling pathways. CaM has the ability to bind more than 300 different target peptides in a Ca2+-dependent manner, mainly through the exposure of hydrophobic residues. How CaM can bind a large number of targets while retaining some selectivity is a fascinating open question. Here, we explore the mechanism of CaM selective promiscuity for selected target proteins. Analyzing enhanced sampling molecular dynamics simulations of Ca2+-bound and Ca2+-free CaM via spectral clustering has allowed us to identify distinct conformational states, characterized by interhelical angles, secondary structure determinants and the solvent exposure of specific residues. We searched for indicators of conformational selection by mapping solvent exposure of residues in these conformational states to contacts in structures of CaM/target peptide complexes. We thereby identified CaM states involved in various binding classes arranged along a depth binding gradient. Binding Ca2+ modifies the accessible hydrophobic surface of the two lobes and allows for deeper binding. Apo CaM indeed shows shallow binding involving predominantly polar and charged residues. Furthermore, binding to the C-terminal lobe of CaM appears selective and involves specific conformational states that can facilitate deep binding to target proteins, while binding to the N-terminal lobe appears to happen through a more flexible mechanism. Thus the long-ranged electrostatic interactions of the charged residues of the N-terminal lobe of CaM may initiate binding, while the short-ranged interactions of hydrophobic residues in the C-terminal lobe of CaM may account for selectivity. This work furthers our understanding of the mechanism of CaM binding and selectivity to different target proteins and paves the way towards a comprehensive model of CaM selectivity.

Widespread changes in network activity allow non-invasive detection of mesial temporal lobe seizures.

PubMed

Lam, Alice D; Zepeda, Rodrigo; Cole, Andrew J; Cash, Sydney S

2016-10-01

Decades of experience with intracranial recordings in patients with epilepsy have demonstrated that seizures can occur in deep cortical regions such as the mesial temporal lobes without showing any obvious signs of seizure activity on scalp electroencephalogram. Predicated on the idea that these seizures are purely focal, currently, the only way to detect these 'scalp-negative seizures' is with intracranial recordings. However, intracranial recordings are only rarely performed in patients with epilepsy, and are almost never performed outside of the context of epilepsy. As such, little is known about scalp-negative seizures and their role in the natural history of epilepsy, their effect on cognitive function, and their association with other neurological diseases. Here, we developed a novel approach to non-invasively identify scalp-negative seizures arising from the mesial temporal lobe based on scalp electroencephalogram network connectivity measures. We identified 25 scalp-negative mesial temporal lobe seizures in 10 patients and obtained control records from an additional 13 patients, all of whom underwent recordings with foramen ovale electrodes and scalp electroencephalogram. Scalp data from these records were used to train a scalp-negative seizure detector, which consisted of a pair of logistic regression classifiers that used scalp electroencephalogram coherence properties as input features. On cross-validation performance, this detector correctly identified scalp-negative seizures in 40% of patients, and correctly identified the side of seizure onset for each seizure detected. In comparison, routine clinical interpretation of these scalp electroencephalograms failed to identify any of the scalp-negative seizures. Among the patients in whom the detector raised seizure alarms, 80% had scalp-negative mesial temporal lobe seizures. The detector had a false alarm rate of only 0.31 per day and a positive predictive value of 75%. Of the 13 control patients, false seizure alarms were raised in only one patient. The fact that our detector specifically recognizes focal mesial temporal lobe seizures based on scalp electroencephalogram coherence features, lends weight to the hypothesis that even focal seizures are a network phenomenon that involve widespread neural connectivity. Our scalp-negative seizure detector has clear clinical utility in patients with temporal lobe epilepsy, and its potential easily translates to other neurological disorders, such as Alzheimer's disease, in which occult mesial temporal lobe seizures are suspected to play a significant role. Importantly, our work establishes a novel approach of using computational approaches to non-invasively detect deep seizure activity, without the need for invasive intracranial recordings. © The Author (2016). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

The interictal language profile in adult epilepsy.

PubMed

Bartha-Doering, Lisa; Trinka, Eugen

2014-10-01

The purpose of this study was to systematically review the literature on the interictal language profile in adult patients with epilepsy. An extensive literature search was performed using MEDLINE, Embase, PsycINFO, Cochrane Central Register of Controlled Trials, PASCAL, and PSYNDEXplus databases. Key aspects of inclusion criteria were adult patients with epilepsy, patient number >10, and in-depth qualitative investigations of a specific language modality or administration of tests of at least two different language modalities, including comprehension, naming, repetition, reading, writing, and spontaneous speech. Our search strategy yielded 933 articles on epilepsy and language. Of these, 31 met final eligibility criteria. Most included articles focused on temporal lobe epilepsy; only three studies were interested in the language profile of patients with idiopathic generalized epilepsies, and one study on frontal lobe epilepsy met inclusion criteria. Study results showed a pronounced heterogeneity of language abilities in patients with epilepsy, varying from intact language profiles to impairment in several language functions. However, at least 17% of patients displayed deficits in more than one language function, with naming, reading comprehension, spontaneous speech, and discourse production being most often affected. This review underscores the need to evaluate different language functions-including spontaneous speech, discourse abilities, naming, auditory and reading comprehension, reading, writing, and repetition-individually in order to obtain a reliable profile of language functioning in patients with epilepsy. Moreover, our findings show that in contrast to the huge scientific interest of memory functions in epilepsy, the examination of language functions so far played a minor role in epilepsy research, emphasizing the need for future research activities in this field. Wiley Periodicals, Inc. © 2014 International League Against Epilepsy.

Differential gene expression in dentate granule cells in mesial temporal lobe epilepsy with and without hippocampal sclerosis.

PubMed

Griffin, Nicole G; Wang, Yu; Hulette, Christine M; Halvorsen, Matt; Cronin, Kenneth D; Walley, Nicole M; Haglund, Michael M; Radtke, Rodney A; Skene, J H Pate; Sinha, Saurabh R; Heinzen, Erin L

2016-03-01

Hippocampal sclerosis is the most common neuropathologic finding in cases of medically intractable mesial temporal lobe epilepsy. In this study, we analyzed the gene expression profiles of dentate granule cells of patients with mesial temporal lobe epilepsy with and without hippocampal sclerosis to show that next-generation sequencing methods can produce interpretable genomic data from RNA collected from small homogenous cell populations, and to shed light on the transcriptional changes associated with hippocampal sclerosis. RNA was extracted, and complementary DNA (cDNA) was prepared and amplified from dentate granule cells that had been harvested by laser capture microdissection from surgically resected hippocampi from patients with mesial temporal lobe epilepsy with and without hippocampal sclerosis. Sequencing libraries were sequenced, and the resulting sequencing reads were aligned to the reference genome. Differential expression analysis was used to ascertain expression differences between patients with and without hippocampal sclerosis. Greater than 90% of the RNA-Seq reads aligned to the reference. There was high concordance between transcriptional profiles obtained for duplicate samples. Principal component analysis revealed that the presence or absence of hippocampal sclerosis was the main determinant of the variance within the data. Among the genes up-regulated in the hippocampal sclerosis samples, there was significant enrichment for genes involved in oxidative phosphorylation. By analyzing the gene expression profiles of dentate granule cells from surgically resected hippocampal specimens from patients with mesial temporal lobe epilepsy with and without hippocampal sclerosis, we have demonstrated the utility of next-generation sequencing methods for producing biologically relevant results from small populations of homogeneous cells, and have provided insight on the transcriptional changes associated with this pathology. Wiley Periodicals, Inc. © 2016 International League Against Epilepsy.

Thalamo-Cortical Disruption Contributes to Short-Term Memory Deficits in Patients with Medial Temporal Lobe Damage.

PubMed

Voets, Natalie L; Menke, Ricarda A L; Jbabdi, Saad; Husain, Masud; Stacey, Richard; Carpenter, Katherine; Adcock, Jane E

2015-11-01

Short-term (STM) and long-term memory (LTM) have largely been considered as separate brain systems reflecting fronto-parietal and medial temporal lobe (MTL) functions, respectively. This functional dichotomy has been called into question by evidence of deficits on aspects of working memory in patients with MTL damage, suggesting a potentially direct hippocampal contribution to STM. As the hippocampus has direct anatomical connections with the thalamus, we tested the hypothesis that damage to thalamic nuclei regulating cortico-cortical interactions may contribute to STM deficits in patients with hippocampal dysfunction. We used diffusion-weighted magnetic resonance imaging-based tractography to identify anatomical subdivisions in patients with MTL epilepsy. From these, we measured resting-state functional connectivity with detailed cortical divisions of the frontal, temporal, and parietal lobes. Whereas thalamo-temporal functional connectivity reflected LTM performance, thalamo-prefrontal functional connectivity specifically predicted STM performance. Notably, patients with hippocampal volume loss showed thalamic volume loss, most prominent in the pulvinar region, not detected in patients with normal hippocampal volumes. Aberrant thalamo-cortical connectivity in the epileptic hemisphere was mirrored in a loss of behavioral association with STM performance specifically in patients with hippocampal atrophy. These findings identify thalamo-cortical disruption as a potential mechanism contributing to STM deficits in the context of MTL damage. © The Author 2015. Published by Oxford University Press.

Etomidate accurately localizes the epileptic area in patients with temporal lobe epilepsy.

PubMed

Pastor, Jesús; Wix, Rybel; Meilán, María Luisa; Martínez-Chacón, José Luís; de Dios, Eva; Domínguez-Gadea, Luis; Herrera-Peco, Iván; Sola, Rafael G

2010-04-01

A variety of drugs have been used to activate and identify the epileptogenic area in patients during presurgical evaluation. We have evaluated the safety and usefulness of etomidate in identifying the epileptic zone by measuring bioelectrical brain activity and cerebral blood flow (CBF). We studied 13 men and 9 women under presurgical evaluation for temporal lobe epilepsy. We applied etomidate (0.1 mg/kg) while patients were monitored by video-electroencephalography (VEEG) with foramen ovale electrodes. In a subset of 15 patients, we also measured CBF with single photon emission computed tomography (SPECT). (1) Etomidate induced seizures in 2 of 22 patients. (2) The main side-effects observed were myoclonus (14 of 20) and moderate pain (3 of 20). (3) No changes in capillary oxygen saturation, respiration, or heart rate were observed. (4) Irritative activity specifically increased in the temporal mesial and lateral areas. No spikes were observed in other areas, aside from those observed under baseline conditions. (5) Irritative activity induced by etomidate correctly lateralized the ictal onset zone in 19 of 20 patients. In addition, the two etomidate-induced seizures appeared in the same regions as spontaneous ones. (6) The kinetics of pharmacologically induced activity was higher in the region of the ictal-onset zone. (7) Etomidate increased the CBF in the basal ganglia and especially in the posterior hippocampus of the temporal mesial region contralateral to the ictal-onset zone. Etomidate activation is a safe, specific, and quick test that can be used to identify the epileptic region in patients evaluated as candidates for temporal lobe epilepsy surgery.

Right hepatic lobe donation adversely affects donor life insurability up to one year after donation.

PubMed

Nissing, Matthew H; Hayashi, Paul H

2005-07-01

There are no data regarding hepatic lobe donation effects on donor life insurability. Two investigators called 10 agents of 10 different large life insurance companies. One investigator gave a fictitious profile: Caucasian man, 33 years old, nonsmoker, without medical problems (control profile [CP]). The other investigator used the same profile with a history of uncomplicated right lobe donation 12 months earlier (donor profile [DP]). Investigators asked for premium quotes on a $100,000 term life policy. No medical testing or record review was allowed. Investigators were blinded to the results of each other's calls. Agents were unaware of the study. We documented underwriting decisions, premiums quoted, stipulations, number of phone calls, and phone time. All 10 companies would pursue underwriting CP at their lowest, "preferred" rate. Five would do the same for DP. Two might underwrite DP at a more expensive "standard" rate, but a "preferred" rate would be less likely. One would underwrite DP at the "standard" rate; one would not underwrite DP. One agent did not return follow-up calls (DP insurability < CP, P = 0.04). Mean quoted premiums were lower for CP vs. DP ($189/yr. vs. $202/yr., P = 0.56). Median number of phone calls required was 1 for CP and 3 for DP (P = 0.01). Mean telephone minutes were 4.2 for CP and 8.0 for DP (P = 0.004). In conclusion, right hepatic lobe donation decreases life insurability 1 year after uncomplicated donation. Donors can expect some increased difficulty obtaining life insurance, but they should find a company willing to pursue underwriting. The premium paid may be slightly higher.

Encoding and immediate retrieval tasks in patients with epilepsy: A functional MRI study of verbal and visual memory.

PubMed

Saddiki, Najat; Hennion, Sophie; Viard, Romain; Ramdane, Nassima; Lopes, Renaud; Baroncini, Marc; Szurhaj, William; Reyns, Nicolas; Pruvo, Jean Pierre; Delmaire, Christine

2018-05-01

Medial lobe temporal structures and more specifically the hippocampus play a decisive role in episodic memory. Most of the memory functional magnetic resonance imaging (fMRI) studies evaluate the encoding phase; the retrieval phase being performed outside the MRI. We aimed to determine the ability to reveal greater hippocampal fMRI activations during retrieval phase. Thirty-five epileptic patients underwent a two-step memory fMRI. During encoding phase, subjects were requested to identify the feminine or masculine gender of faces and words presented, in order to encourage stimulus encoding. One hour after, during retrieval phase, subjects had to recognize the word and face. We used an event-related design to identify hippocampal activations. There was no significant difference between patients with left temporal lobe epilepsy, patients with right temporal lobe epilepsy and patients with extratemporal lobe epilepsy on verbal and visual learning task. For words, patients demonstrated significantly more bilateral hippocampal activation for retrieval task than encoding task and when the tasks were associated than during encoding alone. Significant difference was seen between face-encoding alone and face retrieval alone. This study demonstrates the essential contribution of the retrieval task during a fMRI memory task but the number of patients with hippocampal activations was greater when the two tasks were taken into account. Copyright © 2018. Published by Elsevier Masson SAS.

Noise Reduction with Lobed Mixers: Nozzle-Length and Free-Jet Speed Effects

NASA Technical Reports Server (NTRS)

Mengle, Vinod G.; Dalton, William N.; Bridges, James C.; Boyd, Kathy C.

1997-01-01

Acoustic test results are presented for 1/4th-scaled nozzles with internal lobed mixers used for reduction of subsonic jet noise of turbofan engines with bypass ratio above 5 and jet speeds up to 830 ft/s. One coaxial and three forced lobe mixers were tested with variations in lobe penetration, cut-outs in lobe-sidewall, lobe number and nozzle-length. Measured exit flow profiles and thrusts are used to assist the inferences from acoustic data. It is observed that lobed mixers reduce the low-frequency noise due to more uniformly mixed exit flow; but they may also increase the high-frequency noise at peak perceived noise (PNL) angle and angles upstream of it due to enhanced mixing inside the nozzle. Cut-outs and low lobe penetration reduce the annoying portion of the spectrum but lead to less uniform exit flow. Due to the dominance of internal duct noise in unscalloped, high-penetration mixers their noise is not reduced as much with increase in free-jet speed as that of coaxial or cut-out lobed mixers. The latter two mixers also show no change in PNL over the wide range of nozzle-lengths tested because most of their noise sources are outside the nozzle; whereas, the former show an increase in noise with decrease in nozzle-length.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chillara, Vamshi Krishna; Pantea, Cristian; Sinha, Dipen N.

Here, we numerically investigate the resonance and vibration characteristics of radial modes of laterally stiffened piezoelectric disc transducers. Lateral stiffening is modeled using a spring and vibration characteristics of the piezo-disc are investigated with increasing lateral stiffness. It is found that the resonant frequency response of the radial modes follows an asymptotic behavior approaching that of a clamped disc with increasing lateral stiffness. The radial mode vibration pattern of the discs is also found to be affected by lateral stiffness. While the vibration pattern of a free disc corresponds to a Bessel function, laterally stiffened discs show edge-effects where theymore » depart from the Bessel-like behavior. In addition, a fully clamped piezo-disc is found to have an extra side-lobe when compared to a free disc. Ultrasonic beam profiles generated from radial modes of laterally stiffened discs are numerically investigated. It is found that the free piezo-disc generates a Bessel beam that has multiple side-lobes. Increasing the lateral stiffness results in a significant reduction of side-lobes in the beam profile. This technique of generating a collimated beam with side-lobe reduction finds significant applications in imaging through concrete, drilling mud, and other highly attenuating materials.« less

Identification of environmental sounds and melodies in syndromes of anterior temporal lobe degeneration.

PubMed

Golden, Hannah L; Downey, Laura E; Fletcher, Philip D; Mahoney, Colin J; Schott, Jonathan M; Mummery, Catherine J; Crutch, Sebastian J; Warren, Jason D

2015-05-15

Recognition of nonverbal sounds in semantic dementia and other syndromes of anterior temporal lobe degeneration may determine clinical symptoms and help to define phenotypic profiles. However, nonverbal auditory semantic function has not been widely studied in these syndromes. Here we investigated semantic processing in two key nonverbal auditory domains - environmental sounds and melodies - in patients with semantic dementia (SD group; n=9) and in patients with anterior temporal lobe atrophy presenting with behavioural decline (TL group; n=7, including four cases with MAPT mutations) in relation to healthy older controls (n=20). We assessed auditory semantic performance in each domain using novel, uniform within-modality neuropsychological procedures that determined sound identification based on semantic classification of sound pairs. Both the SD and TL groups showed comparable overall impairments of environmental sound and melody identification; individual patients generally showed superior identification of environmental sounds than melodies, however relative sparing of melody over environmental sound identification also occurred in both groups. Our findings suggest that nonverbal auditory semantic impairment is a common feature of neurodegenerative syndromes with anterior temporal lobe atrophy. However, the profile of auditory domain involvement varies substantially between individuals. Copyright © 2015. Published by Elsevier B.V.

Asymmetric Stokes-V Profiles at the Penumbral Boundary of a Sunspot

NASA Technical Reports Server (NTRS)

Choudhary, Debi Prasad; Balasubramanaim, K. S.; Suematsu, Yoshinori

2003-01-01

We present the spectropolarimetric measurements of a sunspot in the active region NOAA 6958 (15S03W), situated near the central meridian disk passage. The follower polarity sunspot was somewhat symmetrically round shaped with an elongated penumbra. There were several opposite polarity magnetic elements at, and beyond the penumbral boundary. The H-alpha images of the sunspot show the bright emission regions near the penumbral boundary towards the sun-center, which was of opposite polarity with respect to the main spot. The net-circular polarization (NCP) map shows that NCP is negative in the inner part of the spot and positive at the penumbral boundary and near the H-alpha plage. The Doppler velocities were determined by measuring the center-of-gravity (COG) of the Stokes-I profile and zero-crossing (ZC) wavelength of the Stokes-V profiles. The COG velocity map in general agrees with the Evershed flow. In addition, it shows the up flow in the penumbral region. The ZC velocities show the strong down flow at the penumbral boundary. Double-lobed Stokes-V profiles are observed at the locations, where the penumbral fibrils terminate coinciding the H-alpha plage. The Double lobed profiles had an unshifted component similar to the Stokes-V profiles of the sunspot penumbra and a shifted component with a velocity of about 5 km/s. The amplitude of the second component increases along the penumbral fibril as a function of the distance from the center of the sunspot. In this paper we discuss the role of emerging flux in generating the observed double lobed profiles. Based on our present observations, we propose to observe with the Solar-B Spectropolarimeter for understanding the nature of emerging flux near the sunspots.

How the Binding of Human Transferrin Primes the Transferrin Receptor Potentiating Iron Release at Endosomal pH

DOE Office of Scientific and Technical Information (OSTI.GOV)

B Eckenroth; A Steere; N Chasteen

2011-12-31

Delivery of iron to cells requires binding of two iron-containing human transferrin (hTF) molecules to the specific homodimeric transferrin receptor (TFR) on the cell surface. Through receptor-mediated endocytosis involving lower pH, salt, and an unidentified chelator, iron is rapidly released from hTF within the endosome. The crystal structure of a monoferric N-lobe hTF/TFR complex (3.22-{angstrom} resolution) features two binding motifs in the N lobe and one in the C lobe of hTF. Binding of Fe{sub N}hTF induces global and site-specific conformational changes within the TFR ectodomain. Specifically, movements at the TFR dimer interface appear to prime the TFR to undergomore » pH-induced movements that alter the hTF/TFR interaction. Iron release from each lobe then occurs by distinctly different mechanisms: Binding of His349 to the TFR (strengthened by protonation at low pH) controls iron release from the C lobe, whereas displacement of one N-lobe binding motif, in concert with the action of the dilysine trigger, elicits iron release from the N lobe. One binding motif in each lobe remains attached to the same {alpha}-helix in the TFR throughout the endocytic cycle. Collectively, the structure elucidates how the TFR accelerates iron release from the C lobe, slows it from the N lobe, and stabilizes binding of apohTF for return to the cell surface. Importantly, this structure provides new targets for mutagenesis studies to further understand and define this system.« less

Gas kinematics in the H II regions G351.69-1.15 and G351.63-1.25

NASA Astrophysics Data System (ADS)

Veena, V. S.; Vig, S.; Tej, A.; Kantharia, N. G.; Ghosh, S. K.

2017-03-01

We probe the structure and kinematics of two neighbouring H II regions identified as cometary and bipolar, using radio recombination lines (RRLs). The H172α RRLs from these H II regions: G351.69-1.15 and G351.63-1.25, are mapped using Giant Metrewave Radio Telescope, India. We also detect carbon RRLs C172α towards both these regions. The hydrogen RRLs display the effects of pressure and dynamical broadening in the line profiles, with the dynamical broadening (∼15 km s-1) playing a major role in the observed profile of G351.69-1.15. We investigate the kinematics of molecular gas species towards this H II region from the Millimetre Astronomy Legacy Team 90 GHz Pilot Survey. The molecular gas is mostly distributed towards the north and north-west of the cometary head. The molecular line profiles indicate signatures of turbulence and outflow in this region. The ionized gas at the cometary tail is blueshifted by ∼8 km s-1 with respect to the ambient molecular cloud, consistent with the earlier proposed champagne flow scenario. The relative velocity of ∼5 km s-1 between the northern and southern lobes of the bipolar H II region G351.63-1.25 is consistent with the premise that the bipolar morphology is a result of the expanding ionized lobes within a flat molecular cloud.

Frontal alpha asymmetry as a pathway to behavioural withdrawal in depression: Research findings and issues.

PubMed

Jesulola, Emmanuel; Sharpley, Christopher F; Bitsika, Vicki; Agnew, Linda L; Wilson, Peter

2015-10-01

Depression has been described as a process of behavioural withdrawal from overwhelming aversive stressors, and which manifests itself in the diagnostic symptomatology for Major Depressive Disorder (MDD). The underlying neurobiological pathways to that behavioural withdrawal are suggested to include greater activation in the right vs the left frontal lobes, described as frontal EEG asymmetry. However, despite a previous meta-analysis that provided overall support for this EEG asymmetry hypothesis, inconsistencies and several methodological confounds exist. The current review examines the literature on this issue, identifies inconsistencies in findings and discusses several key research issues that require addressing for this field to move towards a defensible theoretical model of depression and EEG asymmetry. In particular, the position of EEG asymmetry in the brain, measurement of severity and symptoms profiles of depression, and the effects of gender are considered as potential avenues to more accurately define the specific nature of the depression-EEG asymmetry association. Copyright © 2015 Elsevier B.V. All rights reserved.

Molecular Dynamics Simulation Reveals Correlated Inter-Lobe Motion in Protein Lysine Methyltransferase SMYD2.

PubMed

Spellmon, Nicholas; Sun, Xiaonan; Sirinupong, Nualpun; Edwards, Brian; Li, Chunying; Yang, Zhe

2015-01-01

SMYD proteins are an exciting field of study as they are linked to many types of cancer-related pathways. Cardiac and skeletal muscle development and function also depend on SMYD proteins opening a possible avenue for cardiac-related treatment. Previous crystal structure studies have revealed that this special class of protein lysine methyltransferases have a bilobal structure, and an open-closed motion may regulate substrate specificity. Here we use the molecular dynamics simulation to investigate the still-poorly-understood SMYD2 dynamics. Cross-correlation analysis reveals that SMYD2 exhibits a negative correlated inter-lobe motion. Principle component analysis suggests that this correlated dynamic is contributed to by a twisting motion of the C-lobe with respect to the N-lobe and a clamshell-like motion between the lobes. Dynamical network analysis defines possible allosteric paths for the correlated dynamics. There are nine communities in the dynamical network with six in the N-lobe and three in the C-lobe, and the communication between the lobes is mediated by a lobe-bridging β hairpin. This study provides insight into the dynamical nature of SMYD2 and could facilitate better understanding of SMYD2 substrate specificity.

Functional relevance of interindividual differences in temporal lobe callosal pathways: a DTI tractography study.

PubMed

Westerhausen, René; Grüner, Renate; Specht, Karsten; Hugdahl, Kenneth

2009-06-01

The midsagittal corpus callosum is topographically organized, that is, with regard to their cortical origin several subtracts can be distinguished within the corpus callosum that belong to specific functional brain networks. Recent diffusion tensor tractography studies have also revealed remarkable interindividual differences in the size and exact localization of these tracts. To examine the functional relevance of interindividual variability in callosal tracts, 17 right-handed male participants underwent structural and diffusion tensor magnetic resonance imaging. Probabilistic tractography was carried out to identify the callosal subregions that interconnect left and right temporal lobe auditory processing areas, and the midsagittal size of this tract was seen as indicator of the (anatomical) strength of this connection. Auditory information transfer was assessed applying an auditory speech perception task with dichotic presentations of consonant-vowel syllables (e.g., /ba-ga/). The frequency of correct left ear reports in this task served as a functional measure of interhemispheric transfer. Statistical analysis showed that a stronger anatomical connection between the superior temporal lobe areas supports a better information transfer. This specific structure-function association in the auditory modality supports the general notion that interindividual differences in callosal topography possess functional relevance.

SEMANTIC DEMENTIA AND PERSISTING WERNICKE’S APHASIA: LINGUISTIC AND ANATOMICAL PROFILES

PubMed Central

Ogar, JM; Baldo, JV; Wilson, SM; Brambati, SM; Miller, BL; Dronkers, NF; Gorno-Tempini, ML

2011-01-01

Few studies have directly compared the clinical and anatomical characteristics of patients with progressive aphasia to those of patients with aphasia caused by stroke. In the current study we examined fluent forms of aphasia in these two groups, specifically the semantic dementia (SD) and persisting Wernicke's aphasia (WA) due to stroke. We compared 10 patients with SD to 10 age- and education-matched patients with WA in three language domains: language comprehension (single words and sentences), spontaneous speech and visual semantics. Neuroanatomical involvement was analyzed using disease-specific image analysis techniques: voxel-based morphometry (VBM) for patients with SD and overlays of lesion masks in patients with WA. Patients with SD and WA were both impaired on tasks that involved visual semantics, but patients with SD were less impaired in spontaneous speech and sentence comprehension. The anatomical findings showed that different regions were most affected in the two disorders: the left anterior temporal lobe in SD and the left posterior middle temporal gyrus in chronic WA. This study highlights that the two syndromes classically associated with language comprehension deficits in aphasia due to stroke and neurodegenerative disease are clinically distinct, most likely due to distinct distributions of damage in the temporal lobe. PMID:21315437

The crystal structure of mammalian inositol 1,3,4,5,6-pentakisphosphate 2-kinase reveals a new zinc-binding site and key features for protein function

PubMed Central

Franco-Echevarría, Elsa; Sanz-Aparicio, Julia; Brearley, Charles A.; González-Rubio, Juana M.; González, Beatriz

2017-01-01

Inositol 1,3,4,5,6-pentakisphosphate 2-kinases (IP5 2-Ks) are part of a family of enzymes in charge of synthesizing inositol hexakisphosphate (IP6) in eukaryotic cells. This protein and its product IP6 present many roles in cells, participating in mRNA export, embryonic development, and apoptosis. We reported previously that the full-length IP5 2-K from Arabidopsis thaliana is a zinc metallo-enzyme, including two separated lobes (the N- and C-lobes). We have also shown conformational changes in IP5 2-K and have identified the residues involved in substrate recognition and catalysis. However, the specific features of mammalian IP5 2-Ks remain unknown. To this end, we report here the first structure for a murine IP5 2-K in complex with ATP/IP5 or IP6. Our structural findings indicated that the general folding in N- and C-lobes is conserved with A. thaliana IP5 2-K. A helical scaffold in the C-lobe constitutes the inositol phosphate-binding site, which, along with the participation of the N-lobe, endows high specificity to this protein. However, we also noted large structural differences between the orthologues from these two eukaryotic kingdoms. These differences include a novel zinc-binding site and regions unique to the mammalian IP5 2-K, as an unexpected basic patch on the protein surface. In conclusion, our findings have uncovered distinct features of a mammalian IP5 2-K and set the stage for investigations into protein-protein or protein-RNA interactions important for IP5 2-K function and activity. PMID:28450399

Electroencephalography in Mesial Temporal Lobe Epilepsy: A Review

PubMed Central

Javidan, Manouchehr

2012-01-01

Electroencephalography (EEG) has an important role in the diagnosis and classification of epilepsy. It can provide information for predicting the response to antiseizure drugs and to identify the surgically remediable epilepsies. In temporal lobe epilepsy (TLE) seizures could originate in the medial or lateral neocortical temporal region, and many of these patients are refractory to medical treatment. However, majority of patients have had excellent results after surgery and this often relies on the EEG and magnetic resonance imaging (MRI) data in presurgical evaluation. If the scalp EEG data is insufficient or discordant, invasive EEG recording with placement of intracranial electrodes could identify the seizure focus prior to surgery. This paper highlights the general information regarding the use of EEG in epilepsy, EEG patterns resembling epileptiform discharges, and the interictal, ictal and postictal findings in mesial temporal lobe epilepsy using scalp and intracranial recordings prior to surgery. The utility of the automated seizure detection and computerized mathematical models for increasing yield of non-invasive localization is discussed. This paper also describes the sensitivity, specificity, and predictive value of EEG for seizure recurrence after withdrawal of medications following seizure freedom with medical and surgical therapy. PMID:22957235

Identifying bvFTD Within the Wide Spectrum of Late Onset Frontal Lobe Syndrome: A Clinical Approach.

PubMed

Krudop, Welmoed A; Kerssens, Cora J; Dols, Annemiek; Prins, Niels D; Möller, Christiane; Schouws, Sigfried; van der Flier, Wiesje M; Scheltens, Philip; Sikkes, Sietske; Stek, Max L; Pijnenburg, Yolande A L

2015-10-01

The behavioral variant of frontotemporal dementia (bvFTD) can be difficult to diagnose because of the extensive differential diagnosis, including many other diseases presenting with a frontal lobe syndrome. We aimed to identify the diagnostic spectrum causing a late onset frontal lobe syndrome and examine the quality of commonly used instruments to distinguish between bvFTD and non-bvFTD patients, within this syndrome. A total of 137 patients fulfilling the criteria of late onset frontal lobe syndrome, aged 45 to 75 years, were included in a prospective observational study. Diagnoses were made after clinical and neuropsychological examination, and neuroimaging and cerebral spinal fluid results were taken into account. Baseline characteristics and the scores on the Mini-Mental State Exam (MMSE), frontal assessment battery (FAB), Frontal Behavioral Inventory (FBI), and Stereotypy Rating Inventory (SRI) were compared between the bvFTD and the non-bvFTD group. Fifty-five (40%) of the patients received a bvFTD diagnosis (33% probable and 7% possible bvFTD). Fifty-one patients (37%) had a psychiatric disorder, including 20 with major depressive disorder. Thirty-one patients received an alternative neurological, including neurodegenerative, diagnosis. MMSE and FAB scores were unspecific for a particular diagnosis. A score above 12 on the positive FBI subscale or a score above 5 on the SRI were indicative of a bvFTD diagnosis. A broad spectrum of both neurological and psychiatric disorders underlies late onset frontal lobe syndrome, of which bvFTD was the most prevalent diagnosis in our cohort. The commonly used MMSE and the FAB could not successfully distinguish between bvFTD and non-bvFTD, but this could be achieved with the more specific FBI and SRI. Copyright © 2015 American Association for Geriatric Psychiatry. Published by Elsevier Inc. All rights reserved.

Neuroimaging correlates of language network impairment and reorganization in temporal lobe epilepsy

PubMed Central

Balter, S.; Lin, G.; Leyden, K.M.; Paul, B.M.; McDonald, C.R.

2016-01-01

Advanced, noninvasive imaging has revolutionized our understanding of language networks in the brain and is reshaping our approach to the presurgical evaluation of patients with epilepsy. Functional magnetic resonance imaging (fMRI) has had the greatest impact, unveiling the complexity of language organization and reorganization in patients with epilepsy both pre- and postoperatively, while volumetric MRI and diffusion tensor imaging have led to a greater appreciation of structural and microstructural correlates of language dysfunction in different epilepsy syndromes. In this article, we review recent literature describing how unimodal and multimodal imaging has advanced our knowledge of language networks and their plasticity in epilepsy, with a focus on the most frequently studied epilepsy syndrome in adults, temporal lobe epilepsy (TLE). We also describe how new analytic techniques (i.e., graph theory) are leading to a refined characterization of abnormal brain connectivity, and how subject-specific imaging profiles combined with clinical data may enhance the prediction of both seizure and language outcomes following surgical interventions. PMID:27393391

Segmentation of the thalamus based on BOLD frequencies affected in temporal lobe epilepsy.

PubMed

Morgan, Victoria L; Rogers, Baxter P; Abou-Khalil, Bassel

2015-11-01

Temporal lobe epilepsy is associated with functional changes throughout the brain, particularly including a putative seizure propagation network involving the hippocampus, insula, and thalamus. We identified a specified frequency range where functional connectivity in this network was related to duration of disease. Then, to identify specific thalamic nuclei involved in seizure propagation, we determined the subregions of the thalamus that have increased resting functional oscillations in this frequency range. Resting-state functional magnetic resonance imaging (fMRI) was acquired from 20 patients with unilateral temporal lobe epilepsy (TLE; 14 right and 6 left) and 20 healthy controls who were each age and gender matched to a specific patient. Wavelet-based fMRI connectivity mapping across the network was computed at each frequency to determine those frequencies where connectivity significantly decreases with duration of disease consistent with impairment due to repeated seizures. The voxel-wise power of the spontaneous blood oxygenation fluctuations of this frequency band was computed in the thalamus of each subject. Functional connectivity was impaired in the proposed seizure propagation network over a specific range (0.0067-0.013 Hz and 0.024-0.032 Hz) of blood oxygenation oscillations. Increased power in this frequency band (<0.032 Hz) was detected bilaterally in the pulvinar and anterior nucleus of the thalamus of healthy controls, and was increased over the ipsilateral thalamus compared to the contralateral thalamus in TLE. This study identified frequencies of impaired connectivity in a TLE seizure propagation network and used them to localize the anterior nucleus and pulvinar of the thalamus as subregions most susceptible to TLE seizures. Further examinations of these frequencies in healthy and TLE subjects may provide unique information relating to the mechanism of seizure propagation and potential treatment using electrical stimulation. Wiley Periodicals, Inc. © 2015 International League Against Epilepsy.

Seismic geomorphology of the Lobed-channel System of Upper Miocene Huangliu Formation, Yinggehai Basin, Northwestern South China Sea

NASA Astrophysics Data System (ADS)

Liu, H.

2016-02-01

Three-dimensional seismic data have been widely used in interpreting ancient river systems and their associated sediment deposits. Thin-bed reservoirs of lobed-channel system in lithostratigraphic units of Dongfang (DF) area are one of the major study areas for reservoir growth in the Yinggehai basin of northwestern South China Sea. Although it is understood that the transport mechanics of parent substrate and alluvium determine the morphology of channel for lobed-channel system, the transport mechanism and regional gradient are relatively poorly understood. This study is focused on the application of various techniques in seismic geomorphology to the Yinggehai Basin at paleo-water-depth of 120m to assess influences of regional gradient and relative sea level change on lobed-channel palaeogeomorphology in shallow-water environments. The Vietnam paleo-Blue River, which located at south of modern Red River, flowed through DF area and transported turbidity deposit to DF area in the coastal environment. In 3-D seismic survey area, four fifth-order sequences in first member of upper Miocene Huangliu formation were identified using well and seismic data. Seismic inversion and 90° phasing of seismic data were used to convert seismic traces to pseudolithologic logs. Stratal slicing made it possible to interpolate and extrapolate well-data-derived sequence and identify submarine fan, channel fill, lobes and overbank deposit. Strata slices suggested that sea-floor slopes exerted main influence on channel morphology. Specifically, DF13-1 block had high gradient, which mainly distributed mud-sand-rich lobes. However, DF13-2 block established low gradient, which mostly indicated sand-rich braided channels. The values of sinuosity, channel widths, meander-belt widths in DF13-2 block are all greater than these in DF13-1 block. In addition, results of carbon isotope measurements and foraminiferal research of two blocks suggest that paleo sea level in DF13-2 block (30m 150m) was higher than that of DF13-1 block (20m 90m). It also deciphered why channels in DF13-2 incised deeply because of the stronger hydrodynamic energy in the shallow-water environments. Thus DF13-2 block was formed in a lobed-channel and sand rich system, compared with DF13-1 of channelized-lobes and mud-sand rich system.

Effects of duloxetine on microRNA expression profile in frontal lobe and hippocampus in a mouse model of depression.

PubMed

Pan, Bing; Liu, Yamei

2015-01-01

Depression is a major mood disorder affecting people worldwide. The posttranscriptional gene regulation mediated by microRNAs (miRNAs) which may have critical roles in the pathogenesis of depression. However, to date, little is known about the effects of the antidepressant drug duloxetine on miRNA expression profile in chronic unpredictable mild stress (CUMS)-induced depression model in mice. Healthy adult male Kunming mice were randomly divided into three groups: control group, model group and duloxetine group. Sucrose preference test and open field test were used to represent the behavioral change. MiRNAs levels in frontal lobe and hippocampus of mice were analyzed using miRNA microarrays assay. We observed that long-term treatment with duloxetine significantly ameliorated the CUMS procedure-induced sucrose preference decreases and mice treated with duloxetine demonstrated a reversal of the number of crossings, and rearings reduced by CUMS. A significant upregulation of miR-132 and miR-18a in hippocampus in the duloxetine treatment group compared with model group, whereas the levels of miR-134 and miR-124a were significantly downregulated. Furthermore, miR-18a showed significant upregulation in frontal lobe in the duloxetine treatment group relative to model group. Our data showed that miRNA expression profile in frontal lobe and hippocampus was affected by duloxetine in mice model of depression. The effect was especially pronounced in the hippocampus, suggesting that hippocampus might be the action site of duloxetine, which presumably worked by regulating the expression of miRNA levels.

Parietal lobe critically supports successful paired immediate and single-item delayed memory for targets.

PubMed

Krumm, Sabine; Kivisaari, Sasa L; Monsch, Andreas U; Reinhardt, Julia; Ulmer, Stephan; Stippich, Christoph; Kressig, Reto W; Taylor, Kirsten I

2017-05-01

The parietal lobe is important for successful recognition memory, but its role is not yet fully understood. We investigated the parietal lobes' contribution to immediate paired-associate memory and delayed item-recognition memory separately for hits (targets) and correct rejections (distractors). We compared the behavioral performance of 56 patients with known parietal and medial temporal lobe dysfunction (i.e. early Alzheimer's Disease) to 56 healthy control participants in an immediate paired and delayed single item object memory task. Additionally, we performed voxel-based morphometry analyses to investigate the functional-neuroanatomic relationships between performance and voxel-based estimates of atrophy in whole-brain analyses. Behaviorally, all participants performed better identifying targets than rejecting distractors. The voxel-based morphometry analyses associated atrophy in the right ventral parietal cortex with fewer correct responses to familiar items (i.e. hits) in the immediate and delayed conditions. Additionally, medial temporal lobe integrity correlated with better performance in rejecting distractors, but not in identifying targets, in the immediate paired-associate task. Our findings suggest that the parietal lobe critically supports successful immediate and delayed target recognition memory, and that the ventral aspect of the parietal cortex and the medial temporal lobe may have complementary preferences for identifying targets and rejecting distractors, respectively, during recognition memory. Copyright © 2017. Published by Elsevier Inc.

Temporal lobe anatomy: eight imaging signs to facilitate interpretation of MRI.

PubMed

Lehman, Vance T; Black, David F; Bernstein, Matt A; Welker, Kirk M

2016-05-01

The temporal lobe is anatomically and functionally complex. However, relatively few radiologic signs are described to facilitate recognition of temporal lobe sulci and gyri in clinical practice. We devised and tested 8 radiologic signs of temporal lobe anatomy. Images from volumetric magnetization-prepared rapid gradient-echo imaging were analyzed of 100 temporal lobes from 26 female and 24 male patients. Patient age ranged from 1 to 79 years (mean 19 years; standard deviation 16 years). Standardized axial, coronal, and sagittal planes were evaluated and cross-referenced. Eight signs to delineate the superior temporal gyrus, Heschl gyrus (HG), parahippocampal gyrus, rhinal sulcus, collateral sulcus proper, or the occipitotemporal sulcus, or a combination, were evaluated in the sagittal or axial plane. Two neuroradiologists independently evaluated each sign; the sign was considered present only with positive reader agreement. All 8 signs were present in most patients. The most frequent signs were the posterior insular corner to identify HG in the axial plane (100 %), pointed STG to identify STG in the axial plane (98 %), and parahippocampal Y to identify the posterior parahippocampal gyrus in the sagittal plane (98 %). The frequencies were similar between the right and left cerebral hemispheres. Temporal lobe gyri and sulci can be reliably identified in multiple planes using anatomic signs.

Radial modes of laterally stiffened piezoelectric disc transducers for ultrasonic collimated beam generation

DOE PAGES

Chillara, Vamshi Krishna; Pantea, Cristian; Sinha, Dipen N.

2017-07-15

Here, we numerically investigate the resonance and vibration characteristics of radial modes of laterally stiffened piezoelectric disc transducers. Lateral stiffening is modeled using a spring and vibration characteristics of the piezo-disc are investigated with increasing lateral stiffness. It is found that the resonant frequency response of the radial modes follows an asymptotic behavior approaching that of a clamped disc with increasing lateral stiffness. The radial mode vibration pattern of the discs is also found to be affected by lateral stiffness. While the vibration pattern of a free disc corresponds to a Bessel function, laterally stiffened discs show edge-effects where theymore » depart from the Bessel-like behavior. In addition, a fully clamped piezo-disc is found to have an extra side-lobe when compared to a free disc. Ultrasonic beam profiles generated from radial modes of laterally stiffened discs are numerically investigated. It is found that the free piezo-disc generates a Bessel beam that has multiple side-lobes. Increasing the lateral stiffness results in a significant reduction of side-lobes in the beam profile. This technique of generating a collimated beam with side-lobe reduction finds significant applications in imaging through concrete, drilling mud, and other highly attenuating materials.« less

LobeFinder: A Convex Hull-Based Method for Quantitative Boundary Analyses of Lobed Plant Cells1[OPEN

PubMed Central

Wu, Tzu-Ching; Belteton, Samuel A.; Szymanski, Daniel B.; Umulis, David M.

2016-01-01

Dicot leaves are composed of a heterogeneous mosaic of jigsaw puzzle piece-shaped pavement cells that vary greatly in size and the complexity of their shape. Given the importance of the epidermis and this particular cell type for leaf expansion, there is a strong need to understand how pavement cells morph from a simple polyhedral shape into highly lobed and interdigitated cells. At present, it is still unclear how and when the patterns of lobing are initiated in pavement cells, and one major technological bottleneck to addressing the problem is the lack of a robust and objective methodology to identify and track lobing events during the transition from simple cell geometry to lobed cells. We developed a convex hull-based algorithm termed LobeFinder to identify lobes, quantify geometric properties, and create a useful graphical output of cell coordinates for further analysis. The algorithm was validated against manually curated images of pavement cells of widely varying sizes and shapes. The ability to objectively count and detect new lobe initiation events provides an improved quantitative framework to analyze mutant phenotypes, detect symmetry-breaking events in time-lapse image data, and quantify the time-dependent correlation between cell shape change and intracellular factors that may play a role in the morphogenesis process. PMID:27288363

Lobar Emphysema Distribution Is Associated With 5-Year Radiological Disease Progression.

PubMed

Boueiz, Adel; Chang, Yale; Cho, Michael H; Washko, George R; San José Estépar, Raul; Bowler, Russell P; Crapo, James D; DeMeo, Dawn L; Dy, Jennifer G; Silverman, Edwin K; Castaldi, Peter J

2018-01-01

Emphysema has considerable variability in its regional distribution. Craniocaudal emphysema distribution is an important predictor of the response to lung volume reduction. However, there is little consensus regarding how to define upper lobe-predominant and lower lobe-predominant emphysema subtypes. Consequently, the clinical and genetic associations with these subtypes are poorly characterized. We sought to identify subgroups characterized by upper-lobe or lower-lobe emphysema predominance and comparable amounts of total emphysema by analyzing data from 9,210 smokers without alpha-1-antitrypsin deficiency in the Genetic Epidemiology of COPD (COPDGene) cohort. CT densitometric emphysema was measured in each lung lobe. Random forest clustering was applied to lobar emphysema variables after regressing out the effects of total emphysema. Clusters were tested for association with clinical and imaging outcomes at baseline and at 5-year follow-up. Their associations with genetic variants were also compared. Three clusters were identified: minimal emphysema (n = 1,312), upper lobe-predominant emphysema (n = 905), and lower lobe-predominant emphysema (n = 796). Despite a similar amount of total emphysema, the lower-lobe group had more severe airflow obstruction at baseline and higher rates of metabolic syndrome compared with subjects with upper-lobe predominance. The group with upper-lobe predominance had greater 5-year progression of emphysema, gas trapping, and dyspnea. Differential associations with known COPD genetic risk variants were noted. Subgroups of smokers defined by upper-lobe or lower-lobe emphysema predominance exhibit different functional and radiological disease progression rates, and the upper-lobe predominant subtype shows evidence of association with known COPD genetic risk variants. These subgroups may be useful in the development of personalized treatments for COPD. Copyright © 2017 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.

Parallel processing via a dual olfactory pathway in the honeybee.

PubMed

Brill, Martin F; Rosenbaum, Tobias; Reus, Isabelle; Kleineidam, Christoph J; Nawrot, Martin P; Rössler, Wolfgang

2013-02-06

In their natural environment, animals face complex and highly dynamic olfactory input. Thus vertebrates as well as invertebrates require fast and reliable processing of olfactory information. Parallel processing has been shown to improve processing speed and power in other sensory systems and is characterized by extraction of different stimulus parameters along parallel sensory information streams. Honeybees possess an elaborate olfactory system with unique neuronal architecture: a dual olfactory pathway comprising a medial projection-neuron (PN) antennal lobe (AL) protocerebral output tract (m-APT) and a lateral PN AL output tract (l-APT) connecting the olfactory lobes with higher-order brain centers. We asked whether this neuronal architecture serves parallel processing and employed a novel technique for simultaneous multiunit recordings from both tracts. The results revealed response profiles from a high number of PNs of both tracts to floral, pheromonal, and biologically relevant odor mixtures tested over multiple trials. PNs from both tracts responded to all tested odors, but with different characteristics indicating parallel processing of similar odors. Both PN tracts were activated by widely overlapping response profiles, which is a requirement for parallel processing. The l-APT PNs had broad response profiles suggesting generalized coding properties, whereas the responses of m-APT PNs were comparatively weaker and less frequent, indicating higher odor specificity. Comparison of response latencies within and across tracts revealed odor-dependent latencies. We suggest that parallel processing via the honeybee dual olfactory pathway provides enhanced odor processing capabilities serving sophisticated odor perception and olfactory demands associated with a complex olfactory world of this social insect.

Examination of the genetic basis for sexual dimorphism in the Aedes aegypti (dengue vector mosquito) pupal brain

PubMed Central

2014-01-01

Background Most animal species exhibit sexually dimorphic behaviors, many of which are linked to reproduction. A number of these behaviors, including blood feeding in female mosquitoes, contribute to the global spread of vector-borne illnesses. However, knowledge concerning the genetic basis of sexually dimorphic traits is limited in any organism, including mosquitoes, especially with respect to differences in the developing nervous system. Methods Custom microarrays were used to examine global differences in female vs. male gene expression in the developing pupal head of the dengue vector mosquito, Aedes aegypti. The spatial expression patterns of a subset of differentially expressed transcripts were examined in the developing female vs. male pupal brain through in situ hybridization experiments. Small interfering RNA (siRNA)-mediated knockdown studies were used to assess the putative role of Doublesex, a terminal component of the sex determination pathway, in the regulation of sex-specific gene expression observed in the developing pupal brain. Results Transcripts (2,527), many of which were linked to proteolysis, the proteasome, metabolism, catabolic, and biosynthetic processes, ion transport, cell growth, and proliferation, were found to be differentially expressed in A. aegypti female vs. male pupal heads. Analysis of the spatial expression patterns for a subset of dimorphically expressed genes in the pupal brain validated the data set and also facilitated the identification of brain regions with dimorphic gene expression. In many cases, dimorphic gene expression localized to the optic lobe. Sex-specific differences in gene expression were also detected in the antennal lobe and mushroom body. siRNA-mediated gene targeting experiments demonstrated that Doublesex, a transcription factor with consensus binding sites located adjacent to many dimorphically expressed transcripts that function in neural development, is required for regulation of sex-specific gene expression in the developing A. aegypti brain. Conclusions These studies revealed sex-specific gene expression profiles in the developing A. aegypti pupal head and identified Doublesex as a key regulator of sexually dimorphic gene expression during mosquito neural development. PMID:25729562

Morphology, structure, composition and build-up processes of the active channel-mouth lobe complex of the Congo deep-sea fan with inputs from remotely operated underwater vehicle (ROV) multibeam and video surveys

NASA Astrophysics Data System (ADS)

Dennielou, Bernard; Droz, Laurence; Babonneau, Nathalie; Jacq, Céline; Bonnel, Cédric; Picot, Marie; Le Saout, Morgane; Saout, Yohan; Bez, Martine; Savoye, Bruno; Olu, Karine; Rabouille, Christophe

2017-08-01

The detailed structure and composition of turbiditic channel-mouth lobes is still largely unknown because they commonly lie at abyssal water depths, are very thin and are therefore beyond the resolution of hull-mound acoustic tools. The morphology, structure and composition of the Congo turbiditic channel-mouth lobe complex (90×40 km; 2525 km2) were investigated with hull-mounted swath bathymetry, air gun seismics, 3.5 kHz sub-bottom profiler, sediment piston cores and also with high-resolution multibeam bathymetry and video acquired with a Remote Operating Vehicle (ROV). The lobe complex lies 760 km off the Congo River mouth in the Angola abyssal plain between 4740 and 5030 m deep. It is active and is fed by turbidity currents that deposit several centimetres of sediment per century. The lobe complex is subdivided into five lobes that have prograded. The lobes are dominantly muddy. Sand represents ca. 13% of the deposits and is restricted to the feeding channel and distributaries. The overall lobe body is composed of thin muddy to silty turbidites. The whole lobe complex is characterized by in situ mass wasting (slumps, debrites). The 1-m-resolution bathymetry shows pervasive slidings and block avalanches on the edges of the feeding channel and the channel mouth indicating that sliding occurs early and continuously in the lobe build-up. Mass wasting is interpreted as a consequence of very-high accumulation rates, over-steepening and erosion along the channels and is therefore an intrinsic process of lobe building. The bifurcation of feeding channels is probably triggered when the gradient in the distributaries at the top of a lobe becomes flat and when turbidity currents find their way on the higher gradient on the lobe side. It may also be triggered by mass wasting on the lobe side. When a new lobe develops, the abandoned lobes continue to collect significant turbiditic deposits from the feeding channel spillover, so that the whole lobe complex remains active. A conceptual lithostratigraphic model is proposed for five morpho-sedimentary environments: lobe rims, lobe body, distributaries, levees, feeding channel. This study shows that high-resolution bathymetry ROV observations are necessary to fully understand the build-up processes of modern channel-mouth lobes.

Ice-Sheet Glaciation of the Puget lowland, Washington, during the Vashon Stade (late pleistocene)

USGS Publications Warehouse

Thorson, R.M.

1980-01-01

During the Vashon Stade of the Fraser Glaciation, about 15,000-13,000 yr B.P., a lobe of the Cordilleran Ice Sheet occupied the Puget lowland of western Washington. At its maximum extent about 14,000 yr ago, the ice sheet extended across the Puget lowland between the Cascade Range and Olympic Mountains and terminated about 80 km south of Seattle. Meltwater streams drained southwest to the Pacific Ocean and built broad outwash trains south of the ice margin. Reconstructed longitudinal profiles for the Puget lobe at its maximum extent are similar to the modern profile of Malaspina Glacier, Alaska, suggesting that the ice sheet may have been in a near-equilibrium state at the glacial maximum. Progressive northward retreat from the terminal zone was accompanied by the development of ice-marginal streams and proglacial lakes that drained southward during initial retreat, but northward during late Vashon time. Relatively rapid retreat of the Juan de Fuca lobe may have contributed to partial stagnation of the northwestern part of the Puget lobe. Final destruction of the Puget lobe occurred when the ice retreated north of Admiralty Inlet. The sea entered the Puget lowland at this time, allowing the deposition of glacial-marine sediments which now occur as high as 50 m altitude. These deposits, together with ice-marginal meltwater channels presumed to have formed above sea level during deglaciation, suggest that a significant amount of postglacial isostatic and(or) tectonic deformation has occurred in the Puget lowland since deglaciation. ?? 1980.

Measurement and Computation of Supersonic Flow in a Lobed Diffuser-Mixer for Trapped Vortex Combustors

NASA Technical Reports Server (NTRS)

Brankovic, Andreja; Ryder, Robert C., Jr.; Hendricks, Robert C.; Liu, Nan-Suey; Gallagher, John R.; Shouse, Dale T.; Roquemore, W. Melvyn; Cooper, Clayton S.; Burrus, David L.; Hendricks, John A.

2002-01-01

The trapped vortex combustor (TVC) pioneered by Air Force Research Laboratories (AFRL) is under consideration as an alternative to conventional gas turbine combustors. The TVC has demonstrated excellent operational characteristics such as high combustion efficiency, low NO(x) emissions, effective flame stabilization, excellent high-altitude relight capability, and operation in the lean-burn or rich burn-quick quench-lean burn (RQL) modes of combustion. It also has excellent potential for lowering the engine combustor weight. This performance at low to moderate combustor mach numbers has stimulated interest in its ability to operate at higher combustion mach number, and for aerospace, this implies potentially higher flight mach numbers. To this end, a lobed diffuser-mixer that enhances the fuel-air mixing in the TVC combustor core was designed and evaluated, with special attention paid to the potential shock system entering the combustor core. For the present investigation, the lobed diffuser-mixer combustor rig is in a full annular configuration featuring sixfold symmetry among the lobes, symmetry within each lobe, and plain parallel, symmetric incident flow. During hardware cold-flow testing, significant discrepancies were found between computed and measured values for the pitot-probe-averaged static pressure profiles at the lobe exit plane. Computational fluid dynamics (CFD) simulations were initiated to determine whether the static pressure probe was causing high local flow-field disturbances in the supersonic flow exiting the diffuser-mixer and whether shock wave impingement on the pitot probe tip, pressure ports, or surface was the cause of the discrepancies. Simulations were performed with and without the pitot probe present in the modeling. A comparison of static pressure profiles without the probe showed that static pressure was off by nearly a factor of 2 over much of the radial profile, even when taking into account potential axial displacement of the probe by up to 0.25 in. (0.64 cm). Including the pitot probe in the CFD modeling and data interpretation lead to good agreement between measurement and prediction. Graphical inspection of the results showed that the shock waves impinging on the probe surface were highly nonuniform, with static pressure varying circumferentially among the pressure ports by over 10 percent in some cases. As part of the measurement methodology, such measurements should be routinely supplemented with CFD analyses that include the pitot probe as part of the flow-path geometry.

Brain volume change and cognitive trajectories in aging.

PubMed

Fletcher, Evan; Gavett, Brandon; Harvey, Danielle; Farias, Sarah Tomaszewski; Olichney, John; Beckett, Laurel; DeCarli, Charles; Mungas, Dan

2018-05-01

Examine how longitudinal cognitive trajectories relate to brain baseline measures and change in lobar volumes in a racially/ethnically and cognitively diverse sample of older adults. Participants were 460 older adults enrolled in a longitudinal aging study. Cognitive outcomes were measures of episodic memory, semantic memory, executive function, and spatial ability derived from the Spanish and English Neuropsychological Assessment Scales (SENAS). Latent variable multilevel modeling of the four cognitive outcomes as parallel longitudinal processes identified intercepts for each outcome and a second order global change factor explaining covariance among the highly correlated slopes. We examined how baseline brain volumes (lobar gray matter, hippocampus, and white matter hyperintensity) and change in brain volumes (lobar gray matter) were associated with cognitive intercepts and global cognitive change. Lobar volumes were dissociated into global and specific components using latent variable methods. Cognitive change was most strongly associated with brain gray matter volume change, with strong independent effects of global gray matter change and specific temporal lobe gray matter change. Baseline white matter hyperintensity and hippocampal volumes had significant incremental effects on cognitive decline beyond gray matter change. Baseline lobar gray matter was related to cognitive decline, but did not contribute beyond gray matter change. Cognitive decline was strongly influenced by gray matter volume change and, especially, temporal lobe change. The strong influence of temporal lobe gray matter change on cognitive decline may reflect involvement of temporal lobe structures that are critical for late life cognitive health but also are vulnerable to diseases of aging. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Evaluation of S-values and dose distributions for {sup 90}Y, {sup 131}I, {sup 166}Ho, and {sup 188}Re in seven lobes of the rat liver

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xie Tianwu; Liu Qian; Zaidi, Habib

2012-03-15

Purpose: Rats have been widely used in radionuclide therapy research for the treatment of hepatocellular carcinoma (HCC). This has created the need to assess rat liver absorbed radiation dose. In most dose estimation studies, the rat liver is considered as a homogeneous integrated target organ with a tissue composition assumed to be similar to that of human liver tissue. However, the rat liver is composed of several lobes having different anatomical and chemical characteristics. To assess the overall impact on rat liver dose calculation, the authors use a new voxel-based rat model with identified suborgan regions of the liver. Methods:more » The liver in the original cryosectional color images was manually segmented into seven individual lobes and subsequently integrated into a voxel-based computational rat model. Photon and electron particle transport was simulated using the MCNPX Monte Carlo code to calculate absorbed fractions and S-values for {sup 90}Y, {sup 131}I, {sup 166}Ho, and {sup 188}Re for the seven liver lobes. The effect of chemical composition on organ-specific absorbed dose was investigated by changing the chemical composition of the voxel filling liver material. Radionuclide-specific absorbed doses at the voxel level were further assessed for a small spherical hepatic tumor. Results: The self-absorbed dose for different liver lobes varied depending on their respective masses. A maximum difference of 3.5% was observed for the liver self-absorbed fraction between rat and human tissues for photon energies below 100 keV. {sup 166}Ho and {sup 188}Re produce a uniformly distributed high dose in the tumor and relatively low absorbed dose for surrounding tissues. Conclusions: The authors evaluated rat liver radiation doses from various radionuclides used in HCC treatments using a realistic computational rat model. This work contributes to a better understanding of all aspects influencing radiation transport in organ-specific radiation dose evaluation for preclinical therapy studies, from tissue composition to organ morphology and activity distribution.« less

Dementia of frontal lobe type.

PubMed Central

Neary, D; Snowden, J S; Northen, B; Goulding, P

1988-01-01

A significant proportion of patients with presenile dementia due to primary cerebral atrophy do not have Alzheimer's disease. One form of non-Alzheimer dementia may be designated as dementia of frontal lobe type (DFT), on the basis of a characteristic neuropsychological picture suggestive of frontal lobe disorder, confirmed by findings on single photon emission tomography. The case histories of seven patients exemplify the disorder: a presentation of social misconduct and personality change, unconcern and disinhibition, in the presence of physical well-being and few neurological signs. Assessment revealed economic and concrete speech with verbal stereotypes, variable memory impairment, and marked abnormalities on tasks sensitive to frontal lobe function. Visuo-spatial disorder was invariably absent. Comparisons of DFT and Alzheimer patients revealed qualitative differences in clinical presentation, neurological signs, profile of psychological disability, electroencephalography, single photon emission tomography and demography. DFT, which may represent forms of Pick's disease, may be more common than is often recognised. PMID:3258902

Sexual dimorphism and phenotypic plasticity in the antennal lobe of a stingless bee, Melipona scutellaris.

PubMed

Roselino, Ana Carolina; Hrncir, Michael; da Cruz Landim, Carminda; Giurfa, Martin; Sandoz, Jean-Christophe

2015-07-01

Among social insects, the stingless bees (Apidae, Meliponini), a mainly tropical group of highly eusocial bees, present an intriguing variety of well-described olfactory-dependent behaviors showing both caste- and sex-specific adaptations. By contrast, little is known about the neural structures underlying such behavioral richness or the olfactory detection and processing abilities of this insect group. This study therefore aimed to provide the first detailed description and comparison of the brains and primary olfactory centers, the antennal lobes, of the different members of a colony of the stingless bee Melipona scutellaris. Global neutral red staining, confocal laser scanning microscopy, and 3D reconstructions were used to compare the brain structures of males, workers, and virgin queens with a special emphasis on the antennal lobe. We found significant differences between both sexes and castes with regard to the relative volumes of olfactory and visual neuropils in the brain and also in the number and volume of the olfactory glomeruli. In addition, we identified one (workers, queens) and three or four (males) macroglomeruli in the antennal lobe. In both sexes and all castes, the largest glomerulus (G1) was located at a similar position relative to four identified landmark glomeruli, close to the entrance of the antennal nerve. This similarity in position suggests that G1s of workers, virgin queens, and males of M. scutellaris may correspond to the same glomerular entity, possibly tuned to queen-emitted volatiles since all colony members need this information. © 2015 Wiley Periodicals, Inc.

Hippocampal and Parahippocampal Volumes in Schizophrenia: A Structural MRI Study

PubMed Central

Sim, Kang; DeWitt, Iain; Ditman, Tali; Zalesak, Martin; Greenhouse, Ian; Goff, Donald; Weiss, Anthony P; Heckers, Stephan

2006-01-01

Smaller medial temporal lobe volume is a frequent finding in studies of patients with schizophrenia, but the relative contributions of the hippocampus and three surrounding cortical regions (entorhinal cortex, perirhinal cortex, and parahippocampal cortex) are poorly understood. We tested the hypothesis that the volumes of medial temporal lobe regions are selectively changed in schizophrenia. We studied 19 male patients with schizophrenia and 19 age-matched male control subjects. Hippocampal and cortical volumes were estimated using a three-dimensional morphometric protocol for the analysis of high-resolution structural magnetic resonance images, and repeated measures ANOVA was used to test for region-specific differences. Patients had smaller overall medial temporal lobe volumes compared to controls. The volume difference was not specific for either region or hemisphere. The finding of smaller medial temporal lobe volumes in the absence of regional specificity has important implications for studying the functional role of the hippocampus and surrounding cortical regions in schizophrenia. PMID:16319377

Semantic dementia and persisting Wernicke's aphasia: linguistic and anatomical profiles.

PubMed

Ogar, J M; Baldo, J V; Wilson, S M; Brambati, S M; Miller, B L; Dronkers, N F; Gorno-Tempini, M L

2011-04-01

Few studies have directly compared the clinical and anatomical characteristics of patients with progressive aphasia to those of patients with aphasia caused by stroke. In the current study we examined fluent forms of aphasia in these two groups, specifically semantic dementia (SD) and persisting Wernicke's aphasia (WA) due to stroke. We compared 10 patients with SD to 10 age- and education-matched patients with WA in three language domains: language comprehension (single words and sentences), spontaneous speech and visual semantics. Neuroanatomical involvement was analyzed using disease-specific image analysis techniques: voxel-based morphometry (VBM) for patients with SD and overlays of lesion digitized lesion reconstructions in patients with WA. Patients with SD and WA were both impaired on tasks that involved visual semantics, but patients with SD were less impaired in spontaneous speech and sentence comprehension. The anatomical findings showed that different regions were most affected in the two disorders: the left anterior temporal lobe in SD and the left posterior middle temporal gyrus in chronic WA. This study highlights that the two syndromes classically associated with language comprehension deficits in aphasia due to stroke and neurodegenerative disease are clinically distinct, most likely due to distinct distributions of damage in the temporal lobe. Copyright © 2010 Elsevier Inc. All rights reserved.

Effects of nitric oxide on expressions of nitrosocysteine and calcium-activated potassium channels in the supraoptic nuclei and neural lobe of dehydrated rats

PubMed Central

Kadekaro, Massako; Su, Guangxiao; Chu, Rong; Lei, Yongzhong; Li, Junfa; Fang, Li

2007-01-01

Nitric oxide (NO) is an important gas mediator in the signal transduction cascade regulating osmotic function in the hypothalamo-neurohypophysial system. We previously found that increased nitric oxide synthase (NOS) activity in the supraoptic nuclei (SON) and neural lobe following osmotic stimulation and NO could regulate the expression of Ca2+-activated K+ channel (BK channels) protein in the magnocellular system during dehydration. The aim of the current study is to examine the role of NO in the regulation of nitrosocysteine and BK channel protein in the magnocellular system in dehydrated animals. Using Western blot analysis and quantitative immunofluorescent staining study, we found that water deprivation in rats significantly enhanced the expression of nitrosocysteine protein in SON and neural lobes. Immunohistochemistry study indicated that dehydration significantly increased the profiles of SON neurons co-expressing nitrosocysteine with BK-channel protein. Intracerebroventricular administration of L-NAME (an inhibitor of NO synthase) significantly reduced the neuronal profiles of nitrosocysteine, as well as their co-expression with BK-channel in SON of dehydrated rats. However, treatment of sodium nitroprusside (a donor of NO) increased this co-expression. Our results indicate that NO signaling cascade may control the expression of BK channels through the regulation of nitrosocysteine in SON and neural lobe of rats during osmotic regulation. PMID:17098363

Sensitivity and specificity of memory and naming tests for identifying left temporal-lobe epilepsy.

PubMed

Umfleet, Laura Glass; Janecek, Julie K; Quasney, Erin; Sabsevitz, David S; Ryan, Joseph J; Binder, Jeffrey R; Swanson, Sara J

2015-01-01

The sensitivity and specificity of the Selective Reminding Test (SRT) Delayed Recall, Wechsler Memory Scale (WMS) Logical Memory, the Boston Naming Test (BNT), and two nonverbal memory measures for detecting lateralized dysfunction in association with side of seizure focus was examined in a sample of 143 patients with left or right temporal-lobe epilepsy (TLE). Scores on the SRT and BNT were statistically significantly lower in the left TLE group compared with the right TLE group, whereas no group differences emerged on the Logical Memory subtest. No significant group differences were found with nonverbal memory measures. When the SRT and BNT were both entered as predictors in a logistic regression, the BNT, although significant, added minimal value to the model beyond the variance accounted for by the SRT Delayed Recall. Both variables emerged as significant predictors of side of seizure focus when entered into separate regressions. Sensitivity and specificity of the SRT and BNT ranged from 56% to 65%. The WMS Logical Memory and nonverbal memory measures were not significant predictors of the side of seizure focus.

Complementary Hemispheric Asymmetries in Object Naming and Recognition: A Voxel-Based Correlational Study

ERIC Educational Resources Information Center

Acres, K.; Taylor, K. I.; Moss, H. E.; Stamatakis, E. A.; Tyler, L. K.

2009-01-01

Cognitive neuroscientific research proposes complementary hemispheric asymmetries in naming and recognising visual objects, with a left temporal lobe advantage for object naming and a right temporal lobe advantage for object recognition. Specifically, it has been proposed that the left inferior temporal lobe plays a mediational role linking…

Elaboration versus suppression of cued memories: influence of memory recall instruction and success on parietal lobe, default network, and hippocampal activity.

PubMed

Gimbel, Sarah I; Brewer, James B

2014-01-01

Functional imaging studies of episodic memory retrieval consistently report task-evoked and memory-related activity in the medial temporal lobe, default network and parietal lobe subregions. Associated components of memory retrieval, such as attention-shifts, search, retrieval success, and post-retrieval processing also influence regional activity, but these influences remain ill-defined. To better understand how top-down control affects the neural bases of memory retrieval, we examined how regional activity responses were modulated by task goals during recall success or failure. Specifically, activity was examined during memory suppression, recall, and elaborative recall of paired-associates. Parietal lobe was subdivided into dorsal (BA 7), posterior ventral (BA 39), and anterior ventral (BA 40) regions, which were investigated separately to examine hypothesized distinctions in sub-regional functional responses related to differential attention-to-memory and memory strength. Top-down suppression of recall abolished memory strength effects in BA 39, which showed a task-negative response, and BA 40, which showed a task-positive response. The task-negative response in default network showed greater negatively-deflected signal for forgotten pairs when task goals required recall. Hippocampal activity was task-positive and was influenced by memory strength only when task goals required recall. As in previous studies, we show a memory strength effect in parietal lobe and hippocampus, but we show that this effect is top-down controlled and sensitive to whether the subject is trying to suppress or retrieve a memory. These regions are all implicated in memory recall, but their individual activity patterns show distinct memory-strength-related responses when task goals are varied. In parietal lobe, default network, and hippocampus, top-down control can override the commonly identified effects of memory strength.

Elaboration versus Suppression of Cued Memories: Influence of Memory Recall Instruction and Success on Parietal Lobe, Default Network, and Hippocampal Activity

PubMed Central

Gimbel, Sarah I.; Brewer, James B.

2014-01-01

Functional imaging studies of episodic memory retrieval consistently report task-evoked and memory-related activity in the medial temporal lobe, default network and parietal lobe subregions. Associated components of memory retrieval, such as attention-shifts, search, retrieval success, and post-retrieval processing also influence regional activity, but these influences remain ill-defined. To better understand how top-down control affects the neural bases of memory retrieval, we examined how regional activity responses were modulated by task goals during recall success or failure. Specifically, activity was examined during memory suppression, recall, and elaborative recall of paired-associates. Parietal lobe was subdivided into dorsal (BA 7), posterior ventral (BA 39), and anterior ventral (BA 40) regions, which were investigated separately to examine hypothesized distinctions in sub-regional functional responses related to differential attention-to-memory and memory strength. Top-down suppression of recall abolished memory strength effects in BA 39, which showed a task-negative response, and BA 40, which showed a task-positive response. The task-negative response in default network showed greater negatively-deflected signal for forgotten pairs when task goals required recall. Hippocampal activity was task-positive and was influenced by memory strength only when task goals required recall. As in previous studies, we show a memory strength effect in parietal lobe and hippocampus, but we show that this effect is top-down controlled and sensitive to whether the subject is trying to suppress or retrieve a memory. These regions are all implicated in memory recall, but their individual activity patterns show distinct memory-strength-related responses when task goals are varied. In parietal lobe, default network, and hippocampus, top-down control can override the commonly identified effects of memory strength. PMID:24586492

Lesion evidence for a critical role of left posterior but not frontal areas in alpha-beta power decreases during context-driven word production.

PubMed

Piai, Vitória; Rommers, Joost; Knight, Robert T

2017-09-09

Different frequency bands in the electroencephalogram are postulated to support distinct language functions. Studies have suggested that alpha-beta power decreases may index word-retrieval processes. In context-driven word retrieval, participants hear lead-in sentences that either constrain the final word ('He locked the door with the') or not ('She walked in here with the'). The last word is shown as a picture to be named. Previous studies have consistently found alpha-beta power decreases prior to picture onset for constrained relative to unconstrained sentences, localised to the left lateral-temporal and lateral-frontal lobes. However, the relative contribution of temporal versus frontal areas to alpha-beta power decreases is unknown. We recorded the electroencephalogram from patients with stroke lesions encompassing the left lateral-temporal and inferior-parietal regions or left-lateral frontal lobe and from matched controls. Individual participant analyses revealed a behavioural sentence context facilitation effect in all participants, except for in the two patients with extensive lesions to temporal and inferior parietal lobes. We replicated the alpha-beta power decreases prior to picture onset in all participants, except for in the two same patients with extensive posterior lesions. Thus, whereas posterior lesions eliminated the behavioural and oscillatory context effect, frontal lesions did not. Hierarchical clustering analyses of all patients' lesion profiles, and behavioural and electrophysiological effects identified those two patients as having a unique combination of lesion distribution and context effects. These results indicate a critical role for the left lateral-temporal and inferior parietal lobes, but not frontal cortex, in generating the alpha-beta power decreases underlying context-driven word production. © 2017 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

IMAGING OF BRAIN FUNCTION BASED ON THE ANALYSIS OF FUNCTIONAL CONNECTIVITY - IMAGING ANALYSIS OF BRAIN FUNCTION BY FMRI AFTER ACUPUNCTURE AT LR3 IN HEALTHY INDIVIDUALS.

PubMed

Zheng, Yu; Wang, Yuying; Lan, Yujun; Qu, Xiaodong; Lin, Kelin; Zhang, Jiping; Qu, Shanshan; Wang, Yanjie; Tang, Chunzhi; Huang, Yong

2016-01-01

This Study observed the relevant brain areas activated by acupuncture at the Taichong acupoint (LR3) and analyzed the functional connectivity among brain areas using resting state functional magnetic resonance imaging (fMRI) to explore the acupoint specificity of the Taichong acupoint. A total of 45 healthy subjects were randomly divided into the Taichong (LR3) group, sham acupuncture group and sham acupoint group. Subjects received resting state fMRI before acupuncture, after true (sham) acupuncture in each group. Analysis of changes in connectivity among the brain areas was performed using the brain functional connectivity method. The right cerebrum temporal lobe was selected as the seed point to analyze the functional connectivity. It had a functional connectivity with right cerebrum superior frontal gyrus, limbic lobe cingulate gyrus and left cerebrum inferior temporal gyrus (BA 37), inferior parietal lobule compared by before vs. after acupuncture at LR3, and right cerebrum sub-lobar insula and left cerebrum middle frontal gyrus, medial frontal gyrus compared by true vs. sham acupuncture at LR3, and right cerebrum occipital lobe cuneus, occipital lobe sub-gyral, parietal lobe precuneus and left cerebellum anterior lobe culmen by acupuncture at LR3 vs. sham acupoint. Acupuncture at LR3 mainly specifically activated the brain functional network that participates in visual function, associative function, and emotion cognition, which are similar to the features on LR3 in tradition Chinese medicine. These brain areas constituted a neural network structure with specific functions that had specific reference values for the interpretation of the acupoint specificity of the Taichong acupoint.

Simulation of a circular phased array for a portable ultrasonic polar scan

NASA Astrophysics Data System (ADS)

Daemen, Jannes; Kersemans, Mathias; Martens, Arvid; Verboven, Erik; Delrue, Steven; Van Paepegem, Wim; Degrieck, Joris; Van Den Abeele, Koen

2018-04-01

The development of new composite materials, often anisotropic in nature, requires intricate approaches to characterize these materials and to detect internal defects. The Ultrasonic Polar Scan (UPS) is able to achieve both goals. During an UPS experiment, a material spot is insonified at several angles Ψ(θ,ϕ), after which the reflected or transmitted signal is recorded. While excellent results have been obtained using an in-house developed 5-axis scanner, UPS measurements with the current set-up are too lengthy and cumbersome for in-situ industrial application. Therefore, we propose to replace the complex mechanical steering of the transducers by a hemispherical phased array consisting of small PZT elements. This allows to create a compact and portable setup without compromising the current data quality. By successively activating a specific set of elements of the array and choosing appropriate inter-element time delays, the beam can be electronically steered from any angle to a fixed position on the targeted sample. Consequently, UPS reflection measurements can be performed at this position from a wide range of angles in a timeframe of seconds. Additionally, by using apodization windows, it is possible to efficiently reduce the intensity of unwanted side lobes and to create a phase profile which closely resembles that of a bounded plane wave, leading to an easier interpretation of the recorded data. The appropriate time delays and apodization parameters can be found though a multi-objective inverse problem in which both the phase profile and the side lobe reduction are optimized. This approach enables the creation of an effective beam profile to be used during UPS experiments for the characterization and inspection of composite materials. Our simulation approach is a crucial step towards a next-generation UPS device for industrial applications and in-field measurements.

Limits to lichenometry

NASA Astrophysics Data System (ADS)

Rosenwinkel, Swenja; Korup, Oliver; Landgraf, Angela; Dzhumabaeva, Atyrgul

2015-12-01

Lichenometry is a straightforward and inexpensive method for dating Holocene rock surfaces. The rationale is that the diameter of the largest lichen scales with the age of the originally fresh rock surface that it colonised. The success of the method depends on finding the largest lichen diameters, a suitable lichen-growth model, and a robust calibration curve. Recent critique of the method motivates us to revisit the accuracy and uncertainties of lichenometry. Specifically, we test how well lichenometry is capable of resolving the ages of different lobes of large active rock glaciers in the Kyrgyz Tien Shan. We use a bootstrapped quantile regression to calibrate local growth curves of Xanthoria elegans, Aspicilia tianshanica, and Rhizocarpon geographicum, and report a nonlinear decrease in dating accuracy with increasing lichen diameter. A Bayesian type of an analysis of variance demonstrates that our calibration allows discriminating credibly between rock-glacier lobes of different ages despite the uncertainties tied to sample size and correctly identifying the largest lichen thalli. Our results also show that calibration error grows with lichen size, so that the separability of rock-glacier lobes of different ages decreases, while the tendency to assign coeval ages increases. The abundant young (<200 yr) specimen of fast-growing X. elegans are in contrast with the fewer, slow-growing, but older (200-1500 yr) R. geographicum and A. tianshanica, and record either a regional reactivation of lobes in the past 200 years, or simply a censoring effect of lichen mortality during early phases of colonisation. The high variance of lichen sizes captures the activity of rock-glacier lobes, which is difficult to explain by regional climatic cooling or earthquake triggers alone. Therefore, we caution against inferring palaeoclimatic conditions from the topographic position of rock-glacier lobes. We conclude that lichenometry works better as a tool for establishing a relative, rather than an absolute, chronology of rock-glacier lobes in the northern Tien Shan.

Asymmetric mismatch in strain-specific genital morphology causes increased harm to Drosophila females.

PubMed

Masly, John P; Kamimura, Yoshitaka

2014-08-01

Although several evolutionary forces have been proposed to contribute to genital morphological diversification, it is unclear which might act early during the evolution of novel structural traits. We test the hypothesis that mismatch between interacting male and female secondary sexual structures gives rise to increased harm to females, consistent with the outcome predicted from a history of sexual conflict. We mate Drosophila sechellia females to males from a collection of D. mauritiana-D. sechellia interspecific genetic introgression lines that possess quantitative morphological variation in the posterior lobe of the genital arch, an external genital structure that can cause wounds to the female abdomen during mating. We find that males with smaller posterior lobes, and those that possess lobes with similarities in shape to D. mauritiana, cause more severe wounding compared to either D. sechellia males with strain-specific morphologies or introgression males that possess larger lobes or lobes with more pronounced D. sechellia features. These results suggest a possible history of sexual conflict during the evolution of the posterior lobe in D. sechellia, but also suggest a potential contribution of divergence in sensory recognition mechanisms to posterior lobe evolution. © 2014 The Author(s). Evolution © 2014 The Society for the Study of Evolution.

Determinants of Autobiographical Memory in Patients with Unilateral Temporal Lobe Epilepsy or Excisions

ERIC Educational Resources Information Center

St-Laurent, Marie; Moscovitch, Morris; Levine, Brian; McAndrews, Mary Pat

2009-01-01

Patients with unilateral temporal lobe epilepsy from hippocampal origin and patients with unilateral surgical excision of an epileptic focus located in the medial temporal lobe were compared to healthy controls on a version of the Autobiographical Interview (AI) adapted to assess memory for event-specific and generic personal episodes. For both…

Material-Specific Lateralization of Working Memory in the Medial Temporal Lobe

ERIC Educational Resources Information Center

Wagner, Dylan D.; Sziklas, Viviane; Garver, Krista E.; Jones-Gotman, Marilyn

2009-01-01

Mnemonic deficits in patients with medial temporal lobe (MTL) damage arising from temporal lobe epilepsy (TLE) are traditionally constrained to long-term episodic memory, sparing short-term and working memory (WM). This view of WM as being independent of MTL structures has recently been challenged by a small number of patient and neuroimaging…

Clinical and imaging correlates of amyloid deposition in dementia with Lewy bodies.

PubMed

Donaghy, Paul C; Firbank, Michael J; Thomas, Alan J; Lloyd, Jim; Petrides, George; Barnett, Nicola; Olsen, Kirsty; O'Brien, John T

2018-04-19

Amyloid deposition is common in dementia with Lewy bodies, but its pathophysiological significance is unclear. The objective of this study was to investigate the relationship between amyloid deposition and clinical profile, gray matter volume, and brain perfusion in dementia with Lewy bodies. Dementia with Lewy bodies (n = 37), Alzheimer's disease (n = 20), and controls (n = 20) underwent a thorough clinical assessment, 3T MRI, and early- and late-phase 18 F-Florbetapir PET-CT to assess cortical perfusion and amyloid deposition, respectively. Amyloid scans were visually categorized as positive or negative. Image analysis was carried out using statistical parametric mapping (SPM) 8. There were no significant differences between amyloid-positive and amyloid-negative dementia with Lewy bodies cases in age (P = .78), overall cognitive impairment (P = .83), level of functional impairment (P = .80), or any other clinical or cognitive scale. There were also no significant differences in hippocampal or gray matter volumes. However, amyloid-positive dementia with Lewy bodies cases had lower medial temporal lobe perfusion (P = .03) than amyloid-negative cases, although a combination of medial temporal lobe perfusion, hippocampal volume, and cognitive measures was unable to accurately predict amyloid status in dementia with Lewy bodies. Amyloid deposition was not associated with differences in clinical or neuropsychological profiles in dementia with Lewy bodies, but was associated with imaging evidence of medial temporal lobe dysfunction. The presence of amyloid in dementia with Lewy bodies cannot be identified on the basis of clinical and other imaging features and will require direct assessment via PET imaging or CSF. © 2018 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society. © 2018 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.

Distal turbidite fan/lobe succession of the Late Oligocene Zuberec Fm. - architecture and hierarchy (Central Western Carpathians, Orava-Podhale basin)

NASA Astrophysics Data System (ADS)

Starek, Dušan; Fuksi, Tomáš

2017-08-01

A part of the Upper Oligocene sand-rich turbidite systems of the Central Carpathian Basin is represented by the Zuberec Formation. Sand/mud-mixed deposits of this formation are well exposed in the northern part of the basin, allowing us to interpret the turbidite succession as terminal lobe deposits of a submarine fan. This interpretation is based on the discrimination of three facies associations that are comparable to different components of distributive lobe deposits in deep-water fan systems. They correspond to the lobe off-axis, lobe fringe and lobe distal fringe depositional subenvironments, respectively. The inferences about the depositional paleoenvironment based on sedimentological observations are verified by statistical analyses. The bed-thickness frequency distributions and vertical organization of the facies associations show cyclic trends at different hierarchical levels that enable us to reconstruct architectural elements of a turbidite fan. First, small-scale trends correspond with shift in the lobe element centroid between successive elements. Differences in the distribution and frequency of sandstone bed thicknesses as well as differences in the shape of bed-thickness frequency distributions between individual facies associations reflect a gradual fining and thinning in a down-dip direction. Second, meso-scale trends are identified within lobes and they generally correspond to the significant periodicity identified by the time series analysis of the bed thicknesses. The meso-scale trends demonstrate shifts in the position of the lobe centroid within the lobe system. Both types of trends have a character of a compensational stacking pattern and could be linked to autogenic processes. Third, a largescale trend documented by generally thickening-upward stacking pattern of beds, accompanied by a general increase of the sandstones/mudstones ratio and by a gradual change of percentage of individual facies, could be comparable to lobe-system scale. This trend probably indicates a gradual basinward progradation of lobe system controlled by allogenic processes related to tectonic activity of sources and sea-level fluctuations.

Examining Brain Morphometry Associated with Self-Esteem in Young Adults Using Multilevel-ROI-Features-Based Classification Method

PubMed Central

Peng, Bo; Lu, Jieru; Saxena, Aditya; Zhou, Zhiyong; Zhang, Tao; Wang, Suhong; Dai, Yakang

2017-01-01

Purpose: This study is to exam self-esteem related brain morphometry on brain magnetic resonance (MR) images using multilevel-features-based classification method. Method: The multilevel region of interest (ROI) features consist of two types of features: (i) ROI features, which include gray matter volume, white matter volume, cerebrospinal fluid volume, cortical thickness, and cortical surface area, and (ii) similarity features, which are based on similarity calculation of cortical thickness between ROIs. For each feature type, a hybrid feature selection method, comprising of filter-based and wrapper-based algorithms, is used to select the most discriminating features. ROI features and similarity features are integrated by using multi-kernel support vector machines (SVMs) with appropriate weighting factor. Results: The classification performance is improved by using multilevel ROI features with an accuracy of 96.66%, a specificity of 96.62%, and a sensitivity of 95.67%. The most discriminating ROI features that are related to self-esteem spread over occipital lobe, frontal lobe, parietal lobe, limbic lobe, temporal lobe, and central region, mainly involving white matter and cortical thickness. The most discriminating similarity features are distributed in both the right and left hemisphere, including frontal lobe, occipital lobe, limbic lobe, parietal lobe, and central region, which conveys information of structural connections between different brain regions. Conclusion: By using ROI features and similarity features to exam self-esteem related brain morphometry, this paper provides a pilot evidence that self-esteem is linked to specific ROIs and structural connections between different brain regions. PMID:28588470

Examining Brain Morphometry Associated with Self-Esteem in Young Adults Using Multilevel-ROI-Features-Based Classification Method.

PubMed

Peng, Bo; Lu, Jieru; Saxena, Aditya; Zhou, Zhiyong; Zhang, Tao; Wang, Suhong; Dai, Yakang

2017-01-01

Purpose: This study is to exam self-esteem related brain morphometry on brain magnetic resonance (MR) images using multilevel-features-based classification method. Method: The multilevel region of interest (ROI) features consist of two types of features: (i) ROI features, which include gray matter volume, white matter volume, cerebrospinal fluid volume, cortical thickness, and cortical surface area, and (ii) similarity features, which are based on similarity calculation of cortical thickness between ROIs. For each feature type, a hybrid feature selection method, comprising of filter-based and wrapper-based algorithms, is used to select the most discriminating features. ROI features and similarity features are integrated by using multi-kernel support vector machines (SVMs) with appropriate weighting factor. Results: The classification performance is improved by using multilevel ROI features with an accuracy of 96.66%, a specificity of 96.62%, and a sensitivity of 95.67%. The most discriminating ROI features that are related to self-esteem spread over occipital lobe, frontal lobe, parietal lobe, limbic lobe, temporal lobe, and central region, mainly involving white matter and cortical thickness. The most discriminating similarity features are distributed in both the right and left hemisphere, including frontal lobe, occipital lobe, limbic lobe, parietal lobe, and central region, which conveys information of structural connections between different brain regions. Conclusion: By using ROI features and similarity features to exam self-esteem related brain morphometry, this paper provides a pilot evidence that self-esteem is linked to specific ROIs and structural connections between different brain regions.

Frontal networks in adults with autism spectrum disorder

PubMed Central

Catani, Marco; Dell’Acqua, Flavio; Budisavljevic, Sanja; Howells, Henrietta; Thiebaut de Schotten, Michel; Froudist-Walsh, Seán; D’Anna, Lucio; Thompson, Abigail; Sandrone, Stefano; Bullmore, Edward T.; Suckling, John; Baron-Cohen, Simon; Lombardo, Michael V.; Wheelwright, Sally J.; Chakrabarti, Bhismadev; Lai, Meng-Chuan; Ruigrok, Amber N. V.; Leemans, Alexander; Ecker, Christine; Consortium, MRC AIMS; Craig, Michael C.

2016-01-01

Abstract It has been postulated that autism spectrum disorder is underpinned by an ‘atypical connectivity’ involving higher-order association brain regions. To test this hypothesis in a large cohort of adults with autism spectrum disorder we compared the white matter networks of 61 adult males with autism spectrum disorder and 61 neurotypical controls, using two complementary approaches to diffusion tensor magnetic resonance imaging. First, we applied tract-based spatial statistics, a ‘whole brain’ non-hypothesis driven method, to identify differences in white matter networks in adults with autism spectrum disorder. Following this we used a tract-specific analysis, based on tractography, to carry out a more detailed analysis of individual tracts identified by tract-based spatial statistics. Finally, within the autism spectrum disorder group, we studied the relationship between diffusion measures and autistic symptom severity. Tract-based spatial statistics revealed that autism spectrum disorder was associated with significantly reduced fractional anisotropy in regions that included frontal lobe pathways. Tractography analysis of these specific pathways showed increased mean and perpendicular diffusivity, and reduced number of streamlines in the anterior and long segments of the arcuate fasciculus, cingulum and uncinate—predominantly in the left hemisphere. Abnormalities were also evident in the anterior portions of the corpus callosum connecting left and right frontal lobes. The degree of microstructural alteration of the arcuate and uncinate fasciculi was associated with severity of symptoms in language and social reciprocity in childhood. Our results indicated that autism spectrum disorder is a developmental condition associated with abnormal connectivity of the frontal lobes. Furthermore our findings showed that male adults with autism spectrum disorder have regional differences in brain anatomy, which correlate with specific aspects of autistic symptoms. Overall these results suggest that autism spectrum disorder is a condition linked to aberrant developmental trajectories of the frontal networks that persist in adult life. PMID:26912520

Frontal networks in adults with autism spectrum disorder.

PubMed

Catani, Marco; Dell'Acqua, Flavio; Budisavljevic, Sanja; Howells, Henrietta; Thiebaut de Schotten, Michel; Froudist-Walsh, Seán; D'Anna, Lucio; Thompson, Abigail; Sandrone, Stefano; Bullmore, Edward T; Suckling, John; Baron-Cohen, Simon; Lombardo, Michael V; Wheelwright, Sally J; Chakrabarti, Bhismadev; Lai, Meng-Chuan; Ruigrok, Amber N V; Leemans, Alexander; Ecker, Christine; Consortium, Mrc Aims; Craig, Michael C; Murphy, Declan G M

2016-02-01

It has been postulated that autism spectrum disorder is underpinned by an 'atypical connectivity' involving higher-order association brain regions. To test this hypothesis in a large cohort of adults with autism spectrum disorder we compared the white matter networks of 61 adult males with autism spectrum disorder and 61 neurotypical controls, using two complementary approaches to diffusion tensor magnetic resonance imaging. First, we applied tract-based spatial statistics, a 'whole brain' non-hypothesis driven method, to identify differences in white matter networks in adults with autism spectrum disorder. Following this we used a tract-specific analysis, based on tractography, to carry out a more detailed analysis of individual tracts identified by tract-based spatial statistics. Finally, within the autism spectrum disorder group, we studied the relationship between diffusion measures and autistic symptom severity. Tract-based spatial statistics revealed that autism spectrum disorder was associated with significantly reduced fractional anisotropy in regions that included frontal lobe pathways. Tractography analysis of these specific pathways showed increased mean and perpendicular diffusivity, and reduced number of streamlines in the anterior and long segments of the arcuate fasciculus, cingulum and uncinate--predominantly in the left hemisphere. Abnormalities were also evident in the anterior portions of the corpus callosum connecting left and right frontal lobes. The degree of microstructural alteration of the arcuate and uncinate fasciculi was associated with severity of symptoms in language and social reciprocity in childhood. Our results indicated that autism spectrum disorder is a developmental condition associated with abnormal connectivity of the frontal lobes. Furthermore our findings showed that male adults with autism spectrum disorder have regional differences in brain anatomy, which correlate with specific aspects of autistic symptoms. Overall these results suggest that autism spectrum disorder is a condition linked to aberrant developmental trajectories of the frontal networks that persist in adult life. © The Author (2016). Published by Oxford University Press on behalf of the Guarantors of Brain.

Neuropsychological functioning in children with temporal lobe epilepsy and hippocampal atrophy without mesial temporal sclerosis: a distinct clinical entity?

PubMed

Schmidt, Charlotte S M; Lassonde, Maryse; Gagnon, Louise; Sauerwein, Catherine H; Carmant, Lionel; Major, Philippe; Paquette, Natacha; Lepore, Franco; Gallagher, Anne

2015-03-01

Unilateral hippocampal atrophy (HA) is considered as a precursor of mesial temporal sclerosis (MTS) in some patients with temporal lobe epilepsy. However, in other cases, it has been suggested that HA without MTS may constitute a distinct epileptic entity. Hippocampal atrophy without MTS was defined as HA without T2-weighted hyperintensity, loss of internal architecture, or associated lesion seen on the MRI data. To date, no study has focused on the cognitive pattern of children with epilepsy with HA without MTS. The objectives of the present study were to characterize the cognitive profile of these children and to investigate the presence (or the absence) of material-specific memory deficits in these young patients, as found in patients with MTS. Toward this end, 16 young patients with epilepsy with either left or right HA without MTS completed a set of neuropsychological tests, assessing overall intelligence, verbal memory and nonverbal memory, and some aspects of attention and executive functions. Results showed normal intellectual functioning without specific memory deficits in these patients. Furthermore, comparison between patients with left HA and patients with right HA failed to reveal a material-specific lateralized memory pattern. Instead, attention and executive functions were found to be impaired in most patients. These results suggest that HA may constitute a distinct epileptic entity, and this information may help health-care providers initiate appropriate and timely interventions. Copyright © 2014 Elsevier Inc. All rights reserved.

DTI-measured white matter abnormalities in adolescents with Conduct Disorder

PubMed Central

Haney-Caron, Emily; Caprihan, Arvind; Stevens, Michael C.

2013-01-01

Emerging research suggests that antisocial behavior in youth is linked to abnormal brain white matter microstructure, but the extent of such anatomical connectivity abnormalities remain largely untested because previous Conduct Disorder (CD) studies typically have selectively focused on specific frontotemporal tracts. This study aimed to replicate and extend previous frontotemporal diffusion tensor imaging (DTI) findings to determine whether noncomorbid CD adolescents have white matter microstructural abnormalities in major white matter tracts across the whole brain. Seventeen CD-diagnosed adolescents recruited from the community were compared to a group of 24 non-CD youth which did not differ in average age (12–18) or gender proportion. Tract-based spatial statistics (TBSS) fractional anisotropy (FA), axial diffusivity (AD), and radial diffusivity (RD) measurements were compared between groups using FSL nonparametric two-sample t test, clusterwise whole-brain corrected, p<.05. CD FA and AD deficits were widespread, but unrelated to gender, verbal ability, or CD age of onset. CD adolescents had significantly lower FA and AD values in frontal lobe and temporal lobe regions, including frontal lobe anterior/superior corona radiata, and inferior longitudinal and fronto-occpital fasciculi passing through the temporal lobe. The magnitude of several CD FA deficits was associated with number of CD symptoms. Because AD, but not RD, differed between study groups, abnormalities of axonal microstructure in CD rather than myelination are suggested. This study provides evidence that adolescent antisocial disorder is linked to abnormal white matter microstructure in more than just the uncinate fasciulcus as identified in previous DTI studies, or frontotemporal brain structures as suggested by functional neuroimaging studies. Instead, neurobiological risk specific to antisociality in adolescence is linked to microstructural abnormality in numerous long-range white matter connections among many diverse different brain regions. PMID:24139595

Constraining the sedimentology and stratigraphy of submarine intraslope lobe deposits using exhumed examples from the Karoo Basin, South Africa

NASA Astrophysics Data System (ADS)

Spychala, Y. T.; Hodgson, D. M.; Flint, S. S.; Mountney, N. P.

2015-06-01

Intraslope lobe deposits provide a process record of the infill of accommodation on submarine slopes and their recognition enables the accurate reconstruction of the stratigraphic evolution of submarine slope systems. Extensive exposures of discrete sand-prone packages in Units D/E and E, Fort Brown Formation, Karoo Basin, South Africa, permit analysis of the sedimentology and stacking patterns of three intraslope lobe complexes and their palaeogeographic reconstruction via bed-scale analysis and physical correlation of key stratal surfaces. The sand-prone packages comprise tabular, aggradationally to slightly compensationally stacked lobe deposits with constituent facies associations that can be attributed to lobe axis, lobe off-axis, lobe-fringe and distal lobe-fringe environments. Locally, intraslope lobe deposits are incised by low aspect ratio channels that mark basinward progradation of the deepwater system. The origin of accommodation on the slope for lobe deposition is interpreted to be due to differential compaction or healing of scars from mass wasting processes. The stacking patterns and sedimentary facies arrangement identified in this study are distinct from those of more commonly recognized basin-floor lobe deposits, thereby enabling the establishment of recognition criteria for intraslope lobe deposits in other less well exposed and studied fine-grained systems. Compared to basin floor lobes, intraslope lobes are smaller in volume, influenced by higher degrees of confinement, and tend to show aggradational stacking patterns.

Sedimentary response to ice stream advance and retreat on the Storfjorden Trough Mouth Fan (NW Barents Sea), during Late Weichselian

NASA Astrophysics Data System (ADS)

Pedrosa, Mayte; Camerlengui, Angelo; de Mol, Ben; Lucchi, Renata. G.; Úrgeles, Roger; Rebesco, Michele; Winsborrow, Monica; Laberg, Jan. S.; Andreassen, Karin; Accettella, Daniela

2010-05-01

This seafloor morphological study of the Storfjorden Trough Mouth Fan (TMF) (offshore Svalbard, NW Barents Sea) is based on new multibeam bathymetry and chirp sub-bottom profiler data acquired in 2007 during the BIO Hespérides cruise SVAIS that provides an unprecedented image of the sedimentary processes that accompanied the last advance and retreat of the Storfjorden Ice Stream. Compared to other glacial-marine sedimentary systems (such as the adjacent Bjørnøyrenna TMF), the Storfjorden TMF system is small and associated to a relatively small terrestrial ice sheet, approximately 40.000 km2, with local provenance from Svalbard and the Spitsbergen Bank. Due to this short distance from the ice source to the calving areas and the resulting short residence time of ice in the ice sheet, therefore the glacio -marine system of the Storfjorden reacts rapidly to climatic changes. The Storfjorden continental slope is characterized by three depositional lobes, produced by focused sedimentation at the terminus of ice streams that have changed their location with time. The superficial morphology features associated to the two northernmost lobes are straight gullies in the upper slope, and debris lobes starting from the midslope onwards. The seafloor expression of the southernmost lobe, adjacent to the much smaller Kveithola TMF, demonstrate almost no gully incisions and is dominated by the widespread occurrence of small-scale submarine landslides. The subbottom profiles illustrate that sediment failures occurred throughout the Late Neogene evolution of the southern Storfjorden and Kveithola margin, including large-scale mass transport deposits of up to 200 m thick. Seismic facies of the Neogene sequence shows an alternation of glacigenic debris flows and laminated sediment drape inferred to be plumites. Gullies incising glacigenic debris flows at the surface and subsurface and are filled by an interglacial drape sequence. The gullies are formed during each deglaciation phase, most likely by the erosive action of short-lived high density currents originated by sediment-loaded subglacial melt water discharge.At the outer continental shelf of the southernmost lobe a striking fresh linear straight, which has a width of 1, 5 kilometres and cut the morainal deposits. These features are interpreted as mega-scale glacial lineations, which are tentatively attributed to mega-iceberg scours. These lineations are witness the latest advances of the Storfjorden ice streams before the final retreat which was located at the southernmost lobe. One of the main pre-conditioning factors to slope instability on the southern part of the Storfjorden TMF is identified as high sedimentation rate plumites deposited on the middle-upper continental slope by glacial melt water plumes. This study is part of the SVAIS project (funded by the Spanish IPY), that has a main objective to improve the understanding and the relationship between sedimentation and ice sheet dynamics under natural climatic changes.

Semantic memory is impaired in patients with unilateral anterior temporal lobe resection for temporal lobe epilepsy.

PubMed

Lambon Ralph, Matthew A; Ehsan, Sheeba; Baker, Gus A; Rogers, Timothy T

2012-01-01

Contemporary clinical and basic neuroscience studies have increasingly implicated the anterior temporal lobe regions, bilaterally, in the formation of coherent concepts. Mounting convergent evidence for the importance of the anterior temporal lobe in semantic memory is found in patients with bilateral anterior temporal lobe damage (e.g. semantic dementia), functional neuroimaging and repetitive transcranial magnetic stimulation studies. If this proposal is correct, then one might expect patients with anterior temporal lobe resection for long-standing temporal lobe epilepsy to be semantically impaired. Such patients, however, do not present clinically with striking comprehension deficits but with amnesia and variable anomia, leading some to conclude that semantic memory is intact in resection for temporal lobe epilepsy and thus casting doubt over the conclusions drawn from semantic dementia and linked basic neuroscience studies. Whilst there is a considerable neuropsychological literature on temporal lobe epilepsy, few studies have probed semantic memory directly, with mixed results, and none have undertaken the same type of systematic investigation of semantic processing that has been conducted with other patient groups. In this study, therefore, we investigated the semantic performance of 20 patients with resection for chronic temporal lobe epilepsy with a full battery of semantic assessments, including more sensitive measures of semantic processing. The results provide a bridge between the current clinical observations about resection for temporal lobe epilepsy and the expectations from semantic dementia and other neuroscience findings. Specifically, we found that on simple semantic tasks, the patients' accuracy fell in the normal range, with the exception that some patients with left resection for temporal lobe epilepsy had measurable anomia. Once the semantic assessments were made more challenging, by probing specific-level concepts, lower frequency/more abstract items or measuring reaction times on semantic tasks versus those on difficulty-matched non-semantic assessments, evidence of a semantic impairment was found in all individuals. We conclude by describing a unified, computationally inspired framework for capturing the variable degrees of semantic impairment found across different patient groups (semantic dementia, temporal lobe epilepsy, glioma and stroke) as well as semantic processing in neurologically intact participants.

Semantic memory is impaired in patients with unilateral anterior temporal lobe resection for temporal lobe epilepsy

PubMed Central

Ehsan, Sheeba; Baker, Gus A.; Rogers, Timothy T.

2012-01-01

Contemporary clinical and basic neuroscience studies have increasingly implicated the anterior temporal lobe regions, bilaterally, in the formation of coherent concepts. Mounting convergent evidence for the importance of the anterior temporal lobe in semantic memory is found in patients with bilateral anterior temporal lobe damage (e.g. semantic dementia), functional neuroimaging and repetitive transcranial magnetic stimulation studies. If this proposal is correct, then one might expect patients with anterior temporal lobe resection for long-standing temporal lobe epilepsy to be semantically impaired. Such patients, however, do not present clinically with striking comprehension deficits but with amnesia and variable anomia, leading some to conclude that semantic memory is intact in resection for temporal lobe epilepsy and thus casting doubt over the conclusions drawn from semantic dementia and linked basic neuroscience studies. Whilst there is a considerable neuropsychological literature on temporal lobe epilepsy, few studies have probed semantic memory directly, with mixed results, and none have undertaken the same type of systematic investigation of semantic processing that has been conducted with other patient groups. In this study, therefore, we investigated the semantic performance of 20 patients with resection for chronic temporal lobe epilepsy with a full battery of semantic assessments, including more sensitive measures of semantic processing. The results provide a bridge between the current clinical observations about resection for temporal lobe epilepsy and the expectations from semantic dementia and other neuroscience findings. Specifically, we found that on simple semantic tasks, the patients’ accuracy fell in the normal range, with the exception that some patients with left resection for temporal lobe epilepsy had measurable anomia. Once the semantic assessments were made more challenging, by probing specific-level concepts, lower frequency/more abstract items or measuring reaction times on semantic tasks versus those on difficulty-matched non-semantic assessments, evidence of a semantic impairment was found in all individuals. We conclude by describing a unified, computationally inspired framework for capturing the variable degrees of semantic impairment found across different patient groups (semantic dementia, temporal lobe epilepsy, glioma and stroke) as well as semantic processing in neurologically intact participants. PMID:22287382

Perfusion-related stimuli for compensatory lung growth following pneumonectomy

PubMed Central

Dane, D. Merrill; Yilmaz, Cuneyt; Gyawali, Dipendra; Iyer, Roshni; Ravikumar, Priya; Estrera, Aaron S.

2016-01-01

Following pneumonectomy (PNX), two separate mechanical forces act on the remaining lung: parenchymal stress caused by lung expansion, and microvascular distension and shear caused by increased perfusion. We previously showed that parenchymal stress and strain explain approximately one-half of overall compensation; the remainder was presumptively attributed to perfusion-related factors. In this study, we directly tested the hypothesis that perturbation of regional pulmonary perfusion modulates post-PNX lung growth. Adult canines underwent banding of the pulmonary artery (PAB) to the left caudal (LCa) lobe, which caused a reduction in basal perfusion to LCa lobe without preventing the subsequent increase in its perfusion following right PNX while simultaneously exaggerating the post-PNX increase in perfusion to the unbanded lobes, thereby creating differential perfusion changes between banded and unbanded lobes. Control animals underwent sham pulmonary artery banding followed by right PNX. Pulmonary function, regional pulmonary perfusion, and high-resolution computed tomography of the chest were analyzed pre-PNX and 3-mo post-PNX. Terminally, the remaining lobes were fixed for detailed morphometric analysis. Results were compared with corresponding lobes in two control (Sham banding and normal unoperated) groups. PAB impaired the indices of post-PNX extravascular alveolar tissue growth by up to 50% in all remaining lobes. PAB enhanced the expected post-PNX increase in alveolar capillary formation, measured by the prevalence of double-capillary profiles, in both unbanded and banded lobes. We conclude that perfusion distribution provides major stimuli for post-PNX compensatory lung growth independent of the stimuli provided by lung expansion and parenchymal stress and strain. PMID:27150830

Metabolic profiling of Alzheimer's disease brains

NASA Astrophysics Data System (ADS)

Inoue, Koichi; Tsutsui, Haruhito; Akatsu, Hiroyasu; Hashizume, Yoshio; Matsukawa, Noriyuki; Yamamoto, Takayuki; Toyo'Oka, Toshimasa

2013-08-01

Alzheimer's disease (AD) is an irreversible, progressive brain disease and can be definitively diagnosed after death through an examination of senile plaques and neurofibrillary tangles in several brain regions. It is to be expected that changes in the concentration and/or localization of low-molecular-weight molecules are linked to the pathological changes that occur in AD, and determining their identity would provide valuable information regarding AD processes. Here, we propose definitive brain metabolic profiling using ultra-performance liquid chromatography coupled with electrospray time-of-flight mass spectrometry analysis. The acquired data were subjected to principal components analysis to differentiate the frontal and parietal lobes of the AD/Control groups. Significant differences in the levels of spermine and spermidine were identified using S-plot, mass spectra, databases and standards. Based on the investigation of the polyamine metabolite pathway, these data establish that the downstream metabolites of ornithine are increased, potentially implicating ornithine decarboxylase activity in AD pathology.

Atlasing the frontal lobe connections and their variability due to age and education: a spherical deconvolution tractography study.

PubMed

Rojkova, K; Volle, E; Urbanski, M; Humbert, F; Dell'Acqua, F; Thiebaut de Schotten, M

2016-04-01

In neuroscience, there is a growing consensus that higher cognitive functions may be supported by distributed networks involving different cerebral regions, rather than by single brain areas. Communication within these networks is mediated by white matter tracts and is particularly prominent in the frontal lobes for the control and integration of information. However, the detailed mapping of frontal connections remains incomplete, albeit crucial to an increased understanding of these cognitive functions. Based on 47 high-resolution diffusion-weighted imaging datasets (age range 22-71 years), we built a statistical normative atlas of the frontal lobe connections in stereotaxic space, using state-of-the-art spherical deconvolution tractography. We dissected 55 tracts including U-shaped fibers. We further characterized these tracts by measuring their correlation with age and education level. We reported age-related differences in the microstructural organization of several, specific frontal fiber tracts, but found no correlation with education level. Future voxel-based analyses, such as voxel-based morphometry or tract-based spatial statistics studies, may benefit from our atlas by identifying the tracts and networks involved in frontal functions. Our atlas will also build the capacity of clinicians to further understand the mechanisms involved in brain recovery and plasticity, as well as assist clinicians in the diagnosis of disconnection or abnormality within specific tracts of individual patients with various brain diseases.

Frontal lobe epilepsy.

PubMed

Kellinghaus, Christoph; Lüders, Hans O

2004-12-01

Frontal lobe epilepsy accounts for only 10-20% of the patients in surgical series, but the incidence in non-surgical patient cohorts seems to be much higher. The typical clinical presentation of the seizures includes contralateral clonic movements, uni- or bilateral tonic motor activity as well as complex automatism. The yield of surface EEG may be limited due to the difficulty in detection of mesial or basal foci, and the patient may be misdiagnosed as having non-epileptic events. In addition, in patients with mesial frontal foci the epileptiform discharges may be mislateralized ("paradoxical lateralization"). Therefore, epilepsy surgery has been commonly considered as less promising in patients with frontal lobe epilepsy. However, the advent of sophisticated neuroimaging techniques, particularly MRI with epilepsy-specific sequences, has made it possible to delineate the epileptogenic lesion and detect a specific etiology, in an increasing number of patients. Thus, the success rate of epilepsy surgery in frontal lobe epilepsy is currently comparable to temporal lobe epilepsy, if the candidates are carefully selected. Patients with frontal lobe epilepsy who do not respond to anticonvulsive medication, and who are not eligible for epilepsy surgery may benefit from alternative approaches such as electrical brain stimulation.

Lung Volume Reduction After Stereotactic Ablative Radiation Therapy of Lung Tumors: Potential Application to Emphysema

DOE Office of Scientific and Technical Information (OSTI.GOV)

Binkley, Michael S.; Shrager, Joseph B.; Stanford Cancer Institute, Stanford University School of Medicine, Stanford, California

2014-09-01

Purpose: Lung volume reduction surgery (LVRS) improves dyspnea and other outcomes in selected patients with severe emphysema, but many have excessive surgical risk for LVRS. We analyzed the dose-volume relationship for lobar volume reduction after stereotactic ablative radiation therapy (SABR) of lung tumors, hypothesizing that SABR could achieve therapeutic volume reduction if applied in emphysema. Methods and Materials: We retrospectively identified patients treated from 2007 to 2011 who had SABR for 1 lung tumor, pre-SABR pulmonary function testing, and ≥6 months computed tomographic (CT) imaging follow-up. We contoured the treated lobe and untreated adjacent lobe(s) on CT before and after SABRmore » and calculated their volume changes relative to the contoured total (bilateral) lung volume (TLV). We correlated lobar volume reduction with the volume receiving high biologically effective doses (BED, α/β = 3). Results: 27 patients met the inclusion criteria, with a median CT follow-up time of 14 months. There was no grade ≥3 toxicity. The median volume reduction of the treated lobe was 4.4% of TLV (range, −0.4%-10.8%); the median expansion of the untreated adjacent lobe was 2.6% of TLV (range, −3.9%-11.6%). The volume reduction of the treated lobe was positively correlated with the volume receiving BED ≥60 Gy (r{sup 2}=0.45, P=.0001). This persisted in subgroups determined by high versus low pre-SABR forced expiratory volume in 1 second, treated lobe CT emphysema score, number of fractions, follow-up CT time, central versus peripheral location, and upper versus lower lobe location, with no significant differences in effect size between subgroups. Volume expansion of the untreated adjacent lobe(s) was positively correlated with volume reduction of the treated lobe (r{sup 2}=0.47, P<.0001). Conclusions: We identified a dose-volume response for treated lobe volume reduction and adjacent lobe compensatory expansion after lung tumor SABR, consistent across multiple clinical parameters. These data serve to inform our ongoing prospective trial of stereotactic ablative volume reduction (SAVR) for severe emphysema in poor candidates for LVRS.« less

Simulation of Cooling and Pressure Effects on Inflated Pahoehoe Lava Flows

NASA Technical Reports Server (NTRS)

Glaze, Lori S.; Baloga, Stephen M.

2016-01-01

Pahoehoe lobes are often emplaced by the advance of discrete toes accompanied by inflation of the lobe surface. Many random effects complicate modeling lobe emplacement, such as the location and orientation of toe breakouts, their dimensions, mechanical strength of the crust, micro-topography and a host of other factors. Models that treat the movement of lava parcels as a random walk have explained some of the overall features of emplacement. However, cooling of the surface and internal pressurization of the fluid interior has not been modeled. This work reports lobe simulations that explicitly incorporate 1) cooling of surface lava parcels, 2) the propensity of breakouts to occur at warmer margins that are mechanically weaker than cooler ones, and 3) the influence of internal pressurization associated with inflation. The surface temperature is interpreted as a surrogate for the mechanic strength of the crust at each location and is used to determine the probability of a lava parcel transfer from that location. When only surface temperature is considered, the morphology and dimensions of simulated lobes are indistinguishable from equiprobable simulations. However, inflation within a lobe transmits pressure to all connected fluid locations with the warmer margins being most susceptible to breakouts and expansion. Simulations accounting for internal pressurization feature morphologies and dimensions that are dramatically different from the equiprobable and temperature-dependent models. Even on flat subsurfaces the pressure-dependent model produces elongate lobes with distinct directionality. Observables such as topographic profiles, aspect ratios, and maximum extents should be readily distinguishable in the field.

Dosimetric evaluation of the feasibility of stereotactic body radiotherapy for primary lung cancer with lobe-specific selective elective nodal irradiation

PubMed Central

Komatsu, Tetsuya; Kunieda, Etsuo; Kitahara, Tadashi; Akiba, Takeshi; Nagao, Ryuta; Fukuzawa, Tsuyoshi

2016-01-01

More than 10% of all patients treated with stereotactic body radiotherapy (SBRT) for primary lung cancer develop regional lymph node recurrence. We evaluated the dosimetric feasibility of SBRT with lobe-specific selective elective nodal irradiation (ENI) on dose–volume histograms. A total of 21 patients were treated with SBRT for Stage I primary lung cancer between January 2010 and June 2012 at our institution. The extents of lobe-specific selective ENI fields were determined with reference to prior surgical reports. The ENI fields included lymph node stations (LNS) 3 + 4 + 11 for the right upper lobe tumors, LNS 7 + 11 for the right middle or lower lobe tumors, LNS 5 + 11 for the left upper lobe tumors, and LNS 7 + 11 for the left lower lobe tumors. A composite plan was generated by combining the ENI plan and the SBRT plan and recalculating for biologically equivalent doses of 2 Gy per fraction, using a linear quadratic model. The V20 of the lung, D1cm3 of the spinal cord, D1cm3 and D10cm3 of the esophagus and D10cm3 of the tracheobronchial wall were evaluated. Of the 21 patients, nine patients (43%) could not fulfill the dose constraints. In all these patients, the distance between the planning target volume (PTV) of ENI (PTVeni) and the PTV of SBRT (PTVsrt) was ≤2.0 cm. Of the three patients who developed regional metastasis, two patients had isolated lymph node failure, and the lymph node metastasis was included within the ENI field. When the distance between the PTVeni and PTVsrt is >2.0 cm, SBRT with selective ENI may therefore dosimetrically feasible. PMID:26566656

Patient-specific connectivity pattern of epileptic network in frontal lobe epilepsy

PubMed Central

Luo, Cheng; An, Dongmei; Yao, Dezhong; Gotman, Jean

2014-01-01

There is evidence that focal epilepsy may involve the dysfunction of a brain network in addition to the focal region. To delineate the characteristics of this epileptic network, we collected EEG/fMRI data from 23 patients with frontal lobe epilepsy. For each patient, EEG/fMRI analysis was first performed to determine the BOLD response to epileptic spikes. The maximum activation cluster in the frontal lobe was then chosen as the seed to identify the epileptic network in fMRI data. Functional connectivity analysis seeded at the same region was also performed in 63 healthy control subjects. Nine features were used to evaluate the differences of epileptic network patterns in three connection levels between patients and controls. Compared with control subjects, patients showed overall more functional connections between the epileptogenic region and the rest of the brain and higher laterality. However, the significantly increased connections were located in the neighborhood of the seed, but the connections between the seed and remote regions actually decreased. Comparing fMRI runs with interictal epileptic discharges (IEDs) and without IEDs, the patient-specific connectivity pattern was not changed significantly. These findings regarding patient-specific connectivity patterns of epileptic networks in FLE reflect local high connectivity and connections with distant regions differing from those of healthy controls. Moreover, the difference between the two groups in most features was observed in the strictest of the three connection levels. The abnormally high connectivity might reflect a predominant attribute of the epileptic network, which may facilitate propagation of epileptic activity among regions in the network. PMID:24936418

Birthdating Studies Reshape Models for Pituitary Gland Cell Specification

PubMed Central

Davis, Shannon W.; Mortensen, Amanda H.; Camper, Sally A.

2011-01-01

The intermediate and anterior lobes of the pituitary gland are derived from an invagination of oral ectoderm that forms Rathke’s pouch. During gestation proliferating cells are enriched around the pouch lumen, and they appear to delaminate as they exit the cell cycle and differentiate. During late mouse gestation and the post-natal period, anterior lobe progenitors re-enter the cell cycle and expand the populations of specialized, hormone-producing cells. At birth, all cell types are present, and their localization appears stratified based on cell type. We conducted a birth dating study of Rathke’s pouch derivatives to determine whether the location of specialized cells at birth is correlated with the timing of cell cycle exit. We find that all of the anterior lobe cell types initiate differentiation concurrently with a peak between e11.5 and e13.5. Differentiation of intermediate lobe melanotropes is delayed relative to anterior lobe cell types. We discovered that specialized cell types are not grouped together based on birth date and are dispersed throughout the anterior lobe. Thus, the apparent stratification of specialized cells at birth is not correlated with cell cycle exit. Thus, the currently popular model of cell specification, dependent upon timing of extrinsic, directional gradients of signaling molecules, needs revision. We propose that signals intrinsic to Rathke’s pouch are necessary for cell specification between e11.5 and e13.5 and that cell-cell communication likely plays an important role in regulating this process. PMID:21262217

Birthdating studies reshape models for pituitary gland cell specification.

PubMed

Davis, Shannon W; Mortensen, Amanda H; Camper, Sally A

2011-04-15

The intermediate and anterior lobes of the pituitary gland are derived from an invagination of oral ectoderm that forms Rathke's pouch. During gestation proliferating cells are enriched around the pouch lumen, and they appear to delaminate as they exit the cell cycle and differentiate. During late mouse gestation and the postnatal period, anterior lobe progenitors re-enter the cell cycle and expand the populations of specialized, hormone-producing cells. At birth, all cell types are present, and their localization appears stratified based on cell type. We conducted a birth dating study of Rathke's pouch derivatives to determine whether the location of specialized cells at birth is correlated with the timing of cell cycle exit. We find that all of the anterior lobe cell types initiate differentiation concurrently with a peak between e11.5 and e13.5. Differentiation of intermediate lobe melanotropes is delayed relative to anterior lobe cell types. We discovered that specialized cell types are not grouped together based on birth date and are dispersed throughout the anterior lobe. Thus, the apparent stratification of specialized cells at birth is not correlated with cell cycle exit. Thus, the currently popular model of cell specification, dependent upon timing of extrinsic, directional gradients of signaling molecules, needs revision. We propose that signals intrinsic to Rathke's pouch are necessary for cell specification between e11.5 and e13.5 and that cell-cell communication likely plays an important role in regulating this process. Copyright © 2011 Elsevier Inc. All rights reserved.

Hyperphosphorylated tau in patients with refractory epilepsy correlates with cognitive decline: a study of temporal lobe resections.

PubMed

Tai, Xin You; Koepp, Matthias; Duncan, John S; Fox, Nick; Thompson, Pamela; Baxendale, Sallie; Liu, Joan Y W; Reeves, Cheryl; Michalak, Zuzanna; Thom, Maria

2016-09-01

SEE BERNASCONI DOI101093/AWW202 FOR A SCIENTIFIC COMMENTARY ON THIS ARTICLE: Temporal lobe epilepsy, the most prevalent form of chronic focal epilepsy, is associated with a high prevalence of cognitive impairment but the responsible underlying pathological mechanisms are unknown. Tau, the microtubule-associated protein, is a hallmark of several neurodegenerative diseases including Alzheimer's disease and chronic traumatic encephalopathy. We hypothesized that hyperphosphorylated tau pathology is associated with cognitive decline in temporal lobe epilepsy and explored this through clinico-pathological study. We first performed pathological examination on tissue from 33 patients who had undergone temporal lobe resection between ages 50 and 65 years to treat drug-refractory temporal lobe epilepsy. We identified hyperphosphorylated tau protein using AT8 immunohistochemistry and compared this distribution to Braak patterns of Alzheimer's disease and patterns of chronic traumatic encephalopathy. We quantified tau pathology using a modified tau score created specifically for analysis of temporal lobectomy tissue and the Braak staging, which was limited without extra-temporal brain areas available. Next, we correlated tau pathology with pre- and postoperative cognitive test scores and clinical risk factors including age at time of surgery, duration of epilepsy, history of secondary generalized seizures, history of head injury, handedness and side of surgery. Thirty-one of 33 cases (94%) showed hyperphosphorylated tau pathology in the form of neuropil threads and neurofibrillary tangles and pre-tangles. Braak stage analysis showed 12% of our epilepsy cohort had a Braak staging III-IV compared to an age-matched non-epilepsy control group from the literature (8%). We identified a mixture of tau pathology patterns characteristic of Alzheimer's disease and chronic traumatic encephalopathy. We also found unusual patterns of subpial tau deposition, sparing of the hippocampus and co-localization with mossy fibre sprouting, a feature of temporal lobe epilepsy. We demonstrated that the more extensive the tau pathology, the greater the decline in verbal learning (Spearman correlation, r = -0.63), recall (r = -0.44) and graded naming test scores (r = -0.50) over 1-year post-temporal lobe resection (P < 0.05). This relationship with tau burden was also present when examining decline in verbal learning from 3 months to 1 year post-resection (r = -0.54). We found an association between modified tau score and history of secondary generalized seizures (likelihood-ratio χ(2), P < 0.05) however there was no clear relationship between tau pathology and other clinical risk factors assessed. Our findings suggest an epilepsy-related tauopathy in temporal lobe epilepsy, which contributes to accelerated cognitive decline and has diagnostic and treatment implications. © The Author (2016). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Hyperphosphorylated tau in patients with refractory epilepsy correlates with cognitive decline: a study of temporal lobe resections

PubMed Central

Tai, Xin You; Koepp, Matthias; Duncan, John S.; Fox, Nick; Thompson, Pamela; Baxendale, Sallie; Liu, Joan Y. W.; Reeves, Cheryl; Michalak, Zuzanna

2016-01-01

Abstract See Bernasconi (doi:10.1093/aww202) for a scientific commentary on this article. Temporal lobe epilepsy, the most prevalent form of chronic focal epilepsy, is associated with a high prevalence of cognitive impairment but the responsible underlying pathological mechanisms are unknown. Tau, the microtubule-associated protein, is a hallmark of several neurodegenerative diseases including Alzheimer’s disease and chronic traumatic encephalopathy. We hypothesized that hyperphosphorylated tau pathology is associated with cognitive decline in temporal lobe epilepsy and explored this through clinico-pathological study. We first performed pathological examination on tissue from 33 patients who had undergone temporal lobe resection between ages 50 and 65 years to treat drug-refractory temporal lobe epilepsy. We identified hyperphosphorylated tau protein using AT8 immunohistochemistry and compared this distribution to Braak patterns of Alzheimer’s disease and patterns of chronic traumatic encephalopathy. We quantified tau pathology using a modified tau score created specifically for analysis of temporal lobectomy tissue and the Braak staging, which was limited without extra-temporal brain areas available. Next, we correlated tau pathology with pre- and postoperative cognitive test scores and clinical risk factors including age at time of surgery, duration of epilepsy, history of secondary generalized seizures, history of head injury, handedness and side of surgery. Thirty-one of 33 cases (94%) showed hyperphosphorylated tau pathology in the form of neuropil threads and neurofibrillary tangles and pre-tangles. Braak stage analysis showed 12% of our epilepsy cohort had a Braak staging III-IV compared to an age-matched non-epilepsy control group from the literature (8%). We identified a mixture of tau pathology patterns characteristic of Alzheimer’s disease and chronic traumatic encephalopathy. We also found unusual patterns of subpial tau deposition, sparing of the hippocampus and co-localization with mossy fibre sprouting, a feature of temporal lobe epilepsy. We demonstrated that the more extensive the tau pathology, the greater the decline in verbal learning (Spearman correlation, r = −0.63), recall (r = −0.44) and graded naming test scores (r = −0.50) over 1-year post-temporal lobe resection (P < 0.05). This relationship with tau burden was also present when examining decline in verbal learning from 3 months to 1 year post-resection (r = −0.54). We found an association between modified tau score and history of secondary generalized seizures (likelihood-ratio χ2, P < 0.05) however there was no clear relationship between tau pathology and other clinical risk factors assessed. Our findings suggest an epilepsy-related tauopathy in temporal lobe epilepsy, which contributes to accelerated cognitive decline and has diagnostic and treatment implications. PMID:27497924

Brain metabolite alterations in infants born preterm with intrauterine growth restriction: association with structural changes and neurodevelopmental outcome.

PubMed

Simões, Rui V; Muñoz-Moreno, Emma; Cruz-Lemini, Mónica; Eixarch, Elisenda; Bargalló, Núria; Sanz-Cortés, Magdalena; Gratacós, Eduard

2017-01-01

Intrauterine growth restriction and premature birth represent 2 independent problems that may occur simultaneously and contribute to impaired neurodevelopment. The objective of the study was to assess changes in the frontal lobe metabolic profiles of 1 year old intrauterine growth restriction infants born prematurely and adequate-for-gestational-age controls, both premature and term adequate for gestational age and their association with brain structural and biophysical parameters and neurodevelopmental outcome at 2 years. A total of 26 prematurely born intrauterine growth restriction infants (birthweight <10th centile for gestational age), 22 prematurely born but adequate for gestational age controls, and 26 term adequate-for-gestational-age infants underwent brain magnetic resonance imaging and magnetic resonance spectroscopy at 1 year of age during natural sleep, on a 3 Tesla scanner. All brain T1-weighted and diffusion-weighted images were acquired along with short echo time single-voxel proton spectra from the frontal lobe. Magnetic resonance imaging/magnetic resonance spectroscopy data were processed to derive structural, biophysical, and metabolic information, respectively. Neurodevelopment was evaluated at 2 years of age using the Bayley Scales 3rd edition, assessing cognitive, language, motor, socioemotional, and adaptive behavior. Prematurely born intrauterine growth restriction infants had slightly smaller brain volumes and increased frontal lobe white matter mean diffusivity compared with both prematurely born but adequate for gestational age and term adequate for gestational age controls. Frontal lobe N-acetylaspartate levels were significantly lower in prematurely born intrauterine growth restriction than in prematurely born but adequate for gestational age infants but increased in prematurely born but adequate for gestational age compared with term adequate-for-gestational-age infants. The prematurely born intrauterine growth restriction group also showed slightly lower choline compounds, borderline decrements of estimated glutathione levels, and increased myoinositol to choline ratios, compared with prematurely born but adequate for gestational age controls. These specific metabolite changes were locally correlated to lower gray matter content and increased mean diffusivity and reduced white matter fraction and fractional anisotropy. Prematurely born intrauterine growth restriction infants also showed a tendency for poorer neurodevelopmental outcome at 2 years, associated with lower levels of frontal lobe N-acetylaspartate at 1 year within the preterm subset. Preterm intrauterine growth restriction infants showed altered brain metabolite profiles during a critical stage of brain maturation, which correlate with brain structural and biophysical parameters and neurodevelopmental outcome. Our results suggest altered neurodevelopmental trajectories in preterm intrauterine growth restriction and adequate-for-gestational-age infants, compared with term adequate-for-gestational-age infants, which require further characterization. Copyright © 2016 Elsevier Inc. All rights reserved.

Comparison between computed tomography and (99m)TC- pertechnetate scintigraphy characteristics of the thyroid gland in cats with hyperthyroidism.

PubMed

Lautenschlaeger, Ines E; Hartmann, Antje; Sicken, Julia; Mohrs, Sabrina; Scholz, Volkher B; Neiger, Reto; Kramer, Martin

2013-01-01

Scintigraphy is currently the reference standard for diagnosing feline hyperthyroidism; however, computed tomography (CT) is more widely available in veterinary practice. The purposes of this prospective study were to describe the CT appearance of thyroid glands in cats with hyperthyroidism and compare CT findings with findings from (99m) Tc-pertechnetate scintigraphy. Twenty-five adult hyperthyroid cats were included. Plain CT images were acquired for each cat and the following characteristics recorded for each thyroid lobe: visibility, delineation, position, attenuation, shape, and subjective size. Scintigraphic images were also acquired and the following characteristics recorded: radiopharmaceutical uptake, delineation, ectopic foci, shape, and subjective size. In CT images, thyroid lobes were most commonly found between the second and fourth cervical vertebrae, dorsolateral to the trachea. Affected thyroid lobes (based on scintigraphy reference standard) were most commonly oval and moderately enlarged in CT images. A heterogeneous attenuation pattern (isoattenuating to adjacent soft tissues with hypo- and hyperattenuating foci) was most commonly found in affected thyroid lobes. A positive correlation (P < 0.01) was identified between CT and scintigraphy for left-to-right thyroid lobe size relationship and subjective size of the larger thyroid lobe. The CT estimated mass was significantly higher (median = 148.8; range = [0;357.6]) for the more active thyroid lobe compared to the less active thyroid lobe (median = 84.6; range = [0;312.3]); (W = 154; P < 0.01). Findings indicated that CT may not reliably differentiate unilateral vs. bilateral hyperthyroidism in cats; however, CT may be a reliable alternative test for correctly identifying the more active thyroid lobe. © 2013 Veterinary Radiology & Ultrasound.

Temporal lobe structures and facial emotion recognition in schizophrenia patients and nonpsychotic relatives.

PubMed

Goghari, Vina M; Macdonald, Angus W; Sponheim, Scott R

2011-11-01

Temporal lobe abnormalities and emotion recognition deficits are prominent features of schizophrenia and appear related to the diathesis of the disorder. This study investigated whether temporal lobe structural abnormalities were associated with facial emotion recognition deficits in schizophrenia and related to genetic liability for the disorder. Twenty-seven schizophrenia patients, 23 biological family members, and 36 controls participated. Several temporal lobe regions (fusiform, superior temporal, middle temporal, amygdala, and hippocampus) previously associated with face recognition in normative samples and found to be abnormal in schizophrenia were evaluated using volumetric analyses. Participants completed a facial emotion recognition task and an age recognition control task under time-limited and self-paced conditions. Temporal lobe volumes were tested for associations with task performance. Group status explained 23% of the variance in temporal lobe volume. Left fusiform gray matter volume was decreased by 11% in patients and 7% in relatives compared with controls. Schizophrenia patients additionally exhibited smaller hippocampal and middle temporal volumes. Patients were unable to improve facial emotion recognition performance with unlimited time to make a judgment but were able to improve age recognition performance. Patients additionally showed a relationship between reduced temporal lobe gray matter and poor facial emotion recognition. For the middle temporal lobe region, the relationship between greater volume and better task performance was specific to facial emotion recognition and not age recognition. Because schizophrenia patients exhibited a specific deficit in emotion recognition not attributable to a generalized impairment in face perception, impaired emotion recognition may serve as a target for interventions.

Identifying the Cognitive Decrements Caused By HIV

DTIC Science & Technology

1994-06-10

critical analyses 46 pointed to further assessment of frontal lobe structures. Most of the 15 different tests yielded more than on* dependent variable...is also one of the tests included in the Multicenter AIDS Cohort Study longitudinal research on the progression of HIV infection. Left frontal lobe ...structures underlie verbal fluency performance and the particular sensitivity of frontal lobe structures to perturbations with HIV infection would

Morphologic Response of the Pulmonary Vasculature to Endoscopic Lung Volume Reduction.

PubMed

Rahaghi, Farbod N; Come, Carolyn E; Ross, James; Harmouche, Rola; Diaz, Alejandro A; Estepar, Raul San Jose; Washko, George

Endoscopic Lung Volume Reduction has been used to reduce lung hyperinflation in selected patients with severe emphysema. Little is known about the effect of this procedure on the intraparenchymal pulmonary vasculature. In this study we used CT based vascular reconstruction to quantify the effect of the procedure on the pulmonary vasculature. Intraparenchymal vasculature was reconstructed and quantified in 12 patients with CT scans at baseline and 12 weeks following bilateral introduction of sealants in the upper lobes. The volume of each lung and each lobe was measured, and the vascular volume profile was calculated for both lower lobes. The detected vasculature was further labeled manually as arterial or venous in the right lower lobe. There was an increase in the volume of the lower lobes (3.14L to 3.25L, p=0.0005). There was an increase in BV5, defined as the volume of blood vessels with cross sectional area of less than 5mm 2 , (53.2ml to 57.9ml, p=0.03). This was found to be correlated with the increase in lower lobe volumes (R=0.65, p=0.02). The changes appear to be symmetric for veins and arteries with a correlation coefficient of 0.87 and a slope of near identity. In the subjects studied, there was an increase, from baseline, in BV5 in the lower lobes that correlated with the change in the volume of the lower lobes. The change appeared to be symmetric for both arteries and veins. The study illustrates the use of intraparenchymal pulmonary vascular reconstruction to study morphologic changes in response to interventions.

Histone Deacetylase Rpd3 Regulates Olfactory Projection Neuron Dendrite Targeting via the Transcription Factor Prospero

PubMed Central

Tea, Joy S.; Chihara, Takahiro; Luo, Liqun

2010-01-01

Compared to the mechanisms of axon guidance, relatively little is known about the transcriptional control of dendrite guidance. The Drosophila olfactory system with its stereotyped organization provides an excellent model to study the transcriptional control of dendrite wiring specificity. Each projection neuron (PN) targets its dendrites to a specific glomerulus in the antennal lobe and its axon stereotypically to higher brain centers. Using a forward genetic screen, we identified a mutation in Rpd3 that disrupts PN targeting specificity. Rpd3 encodes a class I histone deacetylase (HDAC) homologous to mammalian HDAC1 and HDAC2. Rpd3−/− PN dendrites that normally target to a dorsolateral glomerulus mistarget to medial glomeruli in the antennal lobe, and axons exhibit a severe overbranching phenotype. These phenotypes can be rescued by postmitotic expression of Rpd3 but not HDAC3, the only other class I HDAC in Drosophila. Furthermore, disruption of the atypical homeodomain transcription factor Prospero (Pros) yields similar phenotypes, which can be rescued by Pros expression in postmitotic neurons. Strikingly, overexpression of Pros can suppress Rpd3−/− phenotypes. Our study suggests a specific function for the general chromatin remodeling factor Rpd3 in regulating dendrite targeting in neurons, largely through the postmitotic action of the Pros transcription factor. PMID:20660276

Network specific change in white matter integrity in mesial temporal lobe epilepsy.

PubMed

Imamura, Hisaji; Matsumoto, Riki; Takaya, Shigetoshi; Nakagawa, Tomokazu; Shimotake, Akihiro; Kikuchi, Takayuki; Sawamoto, Nobukatsu; Kunieda, Takeharu; Mikuni, Nobuhiro; Miyamoto, Susumu; Fukuyama, Hidenao; Takahashi, Ryosuke; Ikeda, Akio

2016-02-01

To identify the specific change of white matter integrity that occurs in the brain network related to epileptic activity in patients with mesial temporal lobe epilepsy (MTLE). We recruited 18 patients with MTLE and 18 healthy subjects. In MTLE patients, the remote functional-deficit zone was delineated using fluorodeoxyglucose positron emission tomography as an extratemporal region showing glucose hypometabolism. Using diffusion magnetic resonance imaging tractography, we defined a seizure propagation tract (PT) as a white matter pathway that connects the focus with a remote functional deficit zone. We also used the corticospinal tract (CST) and inferior longitudinal fasciculus (ILF) as control tracts in the hemisphere ipsilateral to the focus. Fractional anisotropy (FA), mean diffusivity (MD), and volume of the tracts were compared among PT, CST, and ILF. Tractographic analysis identified the uncinate fasciculus, arcuate fasciculus, and fornix as PTs. A decrease in FA was found in MTLE patients compared with healthy subjects in all tracts, but PTs showed a more significant decrease in FA than did the two control tracts. Although the change in MD was also found in MTLE patients compared with healthy controls, a tract-specific change was not observed. Although white-matter damage was observed in all candidate tracts examined, the integrity of white matter was most significantly decreased in PTs in MTLE. The change in white matter integrity occurs specifically in the pathways that connect the focus and remote functional deficit zones in patients with MTLE, i.e., the pathways that are assume to be associated with seizure propagation. Copyright © 2015 Elsevier B.V. All rights reserved.

Near-death experiences and the temporal lobe.

PubMed

Britton, Willoughby B; Bootzin, Richard R

2004-04-01

Many studies in humans suggest that altered temporal lobe functioning, especially functioning in the right temporal lobe, is involved in mystical and religious experiences. We investigated temporal lobe functioning in individuals who reported having transcendental "near-death experiences" during life-threatening events. These individuals were found to have more temporal lobe epileptiform electroencephalographic activity than control subjects and also reported significantly more temporal lobe epileptic symptoms. Contrary to predictions, epileptiform activity was nearly completely lateralized to the left hemisphere. The near-death experience was not associated with dysfunctional stress reactions such as dissociation, posttraumatic stress disorder, and substance abuse, but rather was associated with positive coping styles. Additional analyses revealed that near-death experiencers had altered sleep patterns, specifically, a shorter duration of sleep and delayed REM sleep relative to the control group. These results suggest that altered temporal lobe functioning may be involved in the near-death experience and that individuals who have had such experiences are physiologically distinct from the general population.

Facies-dependent variations in sediment physical properties on the Mississippi River Delta Front, USA: evidence for depositional and post-depositional processes

NASA Astrophysics Data System (ADS)

Smith, J. E., IV; Bentley, S. J.; Courtois, A. J.; Obelcz, J.; Chaytor, J. D.; Maloney, J. M.; Georgiou, I. Y.; Xu, K.; Miner, M. D.

2017-12-01

Recent studies on Mississippi River Delta have documented sub-aerial land loss, driven in part by declining sediment load over the past century. Impacts of changing sediment load on the subaqueous delta are less well known. The subaqueous Mississippi River Delta Front is known to be shaped by extensive submarine mudflows operating at a range of temporal and spatial scales, however impacts of changing sediment delivery on mudflow deposits have not been investigated. To better understand seabed morphology and stratigraphy as impacted by plume sedimentation and mudflows, an integrated geological/geophysical study was undertaken in delta front regions offshore the three main passes of the Mississippi River Delta. This study focuses on stratigraphy and physical properties of 30 piston cores (5-9 m length) collected in June 2017. Coring locations were selected in gully, lobe and prodelta settings based on multibeam bathymetry and seismic profiles collected in mid-May 2017. Cores were analyzed for density, magnetic susceptibility, P-wave speed, and resistivity using a Geotek multi sensor core logger; here, we focus on density data. Core density profiles generally vary systematically across facies. Density profiles of gully cores are nearly invariant with some downward stepwise increases delineating units meters thick, and abundant gaps likely caused by gas expansion. Lobe cores generally have subtle downward increases in density, some stepwise density increases, and fewer gaps. Prodelta cores show more pronounced downward density increases, decimeter-scale peaks and valleys in density profiles, but stepwise increases are less evident. We hypothesize that density profiles in gully and lobe settings (uniform profiles except for stepwise increases) reflect remolding by mudflows, whereas density variations in prodelta settings instead reflect grain size variations (decimeter-scale) and more advanced consolidation (overall downward density increase) consistent with slower sediment deposition. These hypotheses will be evaluated by a more detailed study of seismic stratigraphy and core properties, including geochronology, grain size distribution and X-radiographic imaging, to further relate important sedimentary processes with resulting deposits.

The Contribution of the Parietal Lobes to Speaking and Writing

PubMed Central

Wise, Richard J. S.

2010-01-01

The left parietal lobe has been proposed as a major language area. However, parietal cortical function is more usually considered in terms of the control of actions, contributing both to attention and cross-modal integration of external and reafferent sensory cues. We used positron emission tomography to study normal subjects while they overtly generated narratives, both spoken and written. The purpose was to identify the parietal contribution to the modality-specific sensorimotor control of communication, separate from amodal linguistic and memory processes involved in generating a narrative. The majority of left and right parietal activity was associated with the execution of writing under visual and somatosensory control irrespective of whether the output was a narrative or repetitive reproduction of a single grapheme. In contrast, action-related parietal activity during speech production was confined to primary somatosensory cortex. The only parietal area with a pattern of activity compatible with an amodal central role in communication was the ventral part of the left angular gyrus (AG). The results of this study indicate that the cognitive processing of language within the parietal lobe is confined to the AG and that the major contribution of parietal cortex to communication is in the sensorimotor control of writing. PMID:19531538

Serotonergic Modulation Differentially Targets Distinct Network Elements within the Antennal Lobe of Drosophila melanogaster

PubMed Central

Sizemore, Tyler R.; Dacks, Andrew M.

2016-01-01

Neuromodulation confers flexibility to anatomically-restricted neural networks so that animals are able to properly respond to complex internal and external demands. However, determining the mechanisms underlying neuromodulation is challenging without knowledge of the functional class and spatial organization of neurons that express individual neuromodulatory receptors. Here, we describe the number and functional identities of neurons in the antennal lobe of Drosophila melanogaster that express each of the receptors for one such neuromodulator, serotonin (5-HT). Although 5-HT enhances odor-evoked responses of antennal lobe projection neurons (PNs) and local interneurons (LNs), the receptor basis for this enhancement is unknown. We used endogenous reporters of transcription and translation for each of the five 5-HT receptors (5-HTRs) to identify neurons, based on cell class and transmitter content, that express each receptor. We find that specific receptor types are expressed by distinct combinations of functional neuronal classes. For instance, the excitatory PNs express the excitatory 5-HTRs, while distinct classes of LNs each express different 5-HTRs. This study therefore provides a detailed atlas of 5-HT receptor expression within a well-characterized neural network, and enables future dissection of the role of serotonergic modulation of olfactory processing. PMID:27845422

Development of the uncinate fasciculus: Implications for theory and developmental disorders.

PubMed

Olson, Ingrid R; Von Der Heide, Rebecca J; Alm, Kylie H; Vyas, Govinda

2015-08-01

The uncinate fasciculus (UF) is a long-range white matter tract that connects limbic regions in the temporal lobe to the frontal lobe. The UF is one of the latest developing tracts, and continues maturing into the third decade of life. As such, individual differences in the maturational profile of the UF may serve to explain differences in behavior. Indeed, atypical macrostructure and microstructure of the UF have been reported in numerous studies of individuals with developmental and psychiatric disorders such as social deprivation and maltreatment, autism spectrum disorders, conduct disorder, risk taking, and substance abuse. The present review evaluates what we currently know about the UF's developmental trajectory and reviews the literature relating UF abnormalities to specific disorders. Additionally, we take a dimensional approach and critically examine symptoms and behavioral impairments that have been demonstrated to cluster with UF aberrations, in an effort to relate these impairments to our speculations regarding the functionality of the UF. We suggest that developmental disorders with core problems relating to memory retrieval, reward and valuation computation, and impulsive decision making may be linked to aberrations in uncinate microstructure. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Segmentation of the Thalamus Based on BOLD Frequencies Affected in Temporal Lobe Epilepsy

PubMed Central

Morgan, Victoria L.; Rogers, Baxter P.; Abou-Khalil, Bassel

2015-01-01

Objective Temporal lobe epilepsy is associated with functional changes throughout the brain, particularly including a putative seizure propagation network involving the hippocampus, insula and thalamus. We identified a specified frequency range where functional connectivity in this network was related to duration of disease. Then, to identify specific thalamic nuclei involved in seizure propagation, we determined the subregions of the thalamus that have increased resting functional oscillations in this frequency range. Methods Resting-state functional MRI (fMRI) was acquired from twenty unilateral TLE (14 right, 6 left) patients and twenty healthy controls who were each age and gender matched to a specific patient. Wavelet based functional MRI connectivity mapping across the network was computed at each frequency to determine those frequencies where connectivity significantly decreases with duration of disease consistent with impairment due to repeated seizures. The voxel-wise power of the spontaneous blood oxygenation fluctuations of this frequency band was computed in the thalamus of each subject. Results Functional connectivity was impaired in the proposed seizure propagation network over a specific range (0.0067–0.013 Hz and 0.024–0.032 Hz) of blood oxygenation oscillations. Increased power in this frequency band (<0.032 Hz) was detected bilaterally in the pulvinar and anterior nucleus of the thalamus of healthy controls, and was increased over the ipsilateral thalamus compared to the contralateral thalamus in TLE. Significance This study identified frequencies of impaired connectivity in a TLE seizure propagation network and used them to localize the anterior nucleus and pulvinar of the thalamus as subregions most susceptible to TLE seizures. Further examinations of these frequencies in healthy and TLE subjects may provide unique information relating to the mechanism of seizure propagation and potential treatment using electrical stimulation. PMID:26360535

Nedley Depression Hit Hypothesis: Identifying Depression and Its Causes.

PubMed

Nedley, Neil; Ramirez, Francisco E

2016-11-01

Depression is often diagnosed using the Diagnostic and Statistical Manual of Mental Disorders Fifth Edition (DSM-5) criteria. We propose how certain lifestyle choices and non-modifiable factors can predict the development of depression. We identified 10 cause categories (hits or "blows" to the brain) and theorize that four or more active hits could trigger a depression episode. Methods. A sample of 4271 participants from our community-based program (70% female; ages 17-94 years) was assessed at baseline and at the eighth week of the program using a custom test. Ten cause categories were examined as predictors of depression are (1) Genetic, (2)Developmental, (3)Lifestyle, (4)Circadian Rhythm, (5)Addiction, (6)Nutrition, (7)Toxic, (8)Social/Complicated Grief, (9)Medical Condition, and (10)Frontal Lobe. Results. The relationship between the DSM-5 score and a person having four hits categories in the first program week showed a sensitivity of 89.98 % (95% CI: 89.20 % - 90.73%), specificity 48.84% (CI 45.94-51.75) and Matthew Correlation Coefficient (MCC) .41 . For the eight-week test, the results showed a sensitivity 83.6% (CI 81.9-85.5), specificity 53.7% (CI 51.7-55.6) and MCC .38. Overall, the hits that improved the most from baseline after the eighth week were: Nutrition (47%), Frontal lobe (36%), Addiction (24%), Circadian rhythm (24%), Lifestyle (20%), Social (12%) and Medical (10%). Conclusions. The Nedley four-hit hypothesis seems to predict a depressive episode and correlates well with the DSM-5 criteria with good sensitivity and MCC but less specificity. Identifying these factors and applying lifestyle therapies could play an important role in the treatment of depressed individuals.

Emplacement of inflated Pāhoehoe flows in the Naude's Nek Pass, Lesotho remnant, Karoo continental flood basalt province: use of flow-lobe tumuli in understanding flood basalt emplacement

NASA Astrophysics Data System (ADS)

Jay, Anne E.; Marsh, Julian S.; Fluteau, Frédéric; Courtillot, Vincent

2018-02-01

Physical volcanological features are presented for a 710-m-thick section, of the Naude's Nek Pass, within the lower part of the Lesotho remnant of the Karoo Large Igneous Province. The section consists of inflated pāhoehoe lava with thin, impersistent sedimentary interbeds towards the base. There are seven discreet packages of compound and hummocky pāhoehoe lobes containing flow-lobe tumuli, making up approximately 50% of the section. Approximately 45% of the sequence consists of 14 sheet lobes, between 10 and 52-m-thick. The majority of the sheet lobes are in two packages indicating prolonged periods of lava supply capable of producing thick sheet lobes. The other sheet lobes are as individual lobes or pairs, within compound flows, suggesting brief increases in lava supply rate. We suggest, contrary to current belief, that there is no evidence that compound flows are proximal to source and sheet lobes (simple flows) are distal to source and we propose that the presence of flow-lobe tumuli in compound flows could be an indicator that a flow is distal to source. We use detailed, previously published, studies of the Thakurvadi Formation (Deccan Traps) as an example. We show that the length of a lobe and therefore the sections that are `medial or distal to source' are specific to each individual lobe and are dependent on the lava supply of each eruptive event, and as such flow lobe tumuli can be used as an indicator of relative distance from source.

Identification of Amnestic Mild Cognitive Impairment Using Multi-Modal Brain Features: A Combined Structural MRI and Diffusion Tensor Imaging Study.

PubMed

Xie, Yunyan; Cui, Zaixu; Zhang, Zhongmin; Sun, Yu; Sheng, Can; Li, Kuncheng; Gong, Gaolang; Han, Ying; Jia, Jianping

2015-01-01

Identifying amnestic mild cognitive impairment (aMCI) is of great clinical importance because aMCI is a putative prodromal stage of Alzheimer's disease. The present study aimed to explore the feasibility of accurately identifying aMCI with a magnetic resonance imaging (MRI) biomarker. We integrated measures of both gray matter (GM) abnormalities derived from structural MRI and white matter (WM) alterations acquired from diffusion tensor imaging at the voxel level across the entire brain. In particular, multi-modal brain features, including GM volume, WM fractional anisotropy, and mean diffusivity, were extracted from a relatively large sample of 64 Han Chinese aMCI patients and 64 matched controls. Then, support vector machine classifiers for GM volume, FA, and MD were fused to distinguish the aMCI patients from the controls. The fused classifier was evaluated with the leave-one-out and the 10-fold cross-validations, and the classifier had an accuracy of 83.59% and an area under the curve of 0.862. The most discriminative regions of GM were mainly located in the medial temporal lobe, temporal lobe, precuneus, cingulate gyrus, parietal lobe, and frontal lobe, whereas the most discriminative regions of WM were mainly located in the corpus callosum, cingulum, corona radiata, frontal lobe, and parietal lobe. Our findings suggest that aMCI is characterized by a distributed pattern of GM abnormalities and WM alterations that represent discriminative power and reflect relevant pathological changes in the brain, and these changes further highlight the advantage of multi-modal feature integration for identifying aMCI.

Pre- and post-operative Wisconsin card sorting test performance in patients with temporal lobe epilepsy due to hippocampal sclerosis

PubMed Central

Tisser, Luciana; Palmini, Andre; Paglioli, Eliseu; Portuguez, Mirna; Azambuja, Ney; da Costa, Jaderson Costa; Paglioli, Eduardo; Torres, Carolina; Martinez, Jose Victor

2007-01-01

Patients with temporal lobe epilepsy due to hippocampal sclerosis (TLE/HS) have a distinct neuropsychological profile, but there is still debate on whether executive dysfunction is part of this profile and also whether temporal lobe surgery can modify this dysfunction. Objective To study the presence and reversibility of executive dysfunction in patients with unilateral TLE/HS. Methods Twenty-five patients with refractory seizures due to TLE/HS underwent presurgical evaluation which included the application of the Wiconsin Card Sorting Test (WCST). Nineteen were re-evaluated in follow up, at least 6 months after selective amygdalo-hippocampectomy (SAH). Twenty-two control subjects matched for age and education also performed the WCST. Results Sixteen of the 25 patients (64%) completed fewer than four categories in the WCST whereas only 4 of the 22 controls (18%) did not complete at least four categories (p<0.005). In addition, the performance of the patients involved significantly more perseverative responses and errors compared to controls. The patient group demonstrated significant post-operative improvement in many measures of the WCST following SAH. Conclusions These findings support the presence of executive dysfunction in patients with TLE/HS and suggest that such dysfunction can be partially reversed by selective resection of epileptogenic mesial temporal structures. PMID:29213385

Vascular anatomy of canine hepatic venous system: a basis for liver surgery.

PubMed

Mari, L; Acocella, F

2015-06-01

Detailed knowledge of the vascular anatomy is important for improving surgical approaches to the liver. Twelve canine livers were skeletonized to describe the anatomy of their portal and hepatic veins in details. Our data suggest that the liver can be divided into two sections, three divisions, seven lobes and two to four sub-lobes. This differs from the classic division into four lobes, four sub-lobes and two processes. The right section was perfused by the right portal branch and drained by independent hepatic veins, while most of the left section, perfused by the left portal branch, was drained by the main hepatic vein deriving from the middle and the left hepatic vein confluence. Part of the right medial lobe, and in some cases the papillary process of the caudate lobe, drained directly into the caudal vena cava. A proper right hepatic vein draining blood from more than one lobe was never observed. Portal connections between the quadrate and the left medial lobe were frequently recorded. Two sub-lobes with different portal blood supply and venous drainage could be identified in the right lateral (33.3% of cases) and the left lateral (100% of cases) lobes. From our results, the classic nomenclature of the liver lobes does not reflect their vascularization. Based on similarities between canine lobes and human segments, a new nomenclature is possible and may be less confounding in surgical settings. © 2014 Blackwell Verlag GmbH.

White matter integrity in dyskinetic cerebral palsy: Relationship with intelligence quotient and executive function.

PubMed

Laporta-Hoyos, Olga; Pannek, Kerstin; Ballester-Plané, Júlia; Reid, Lee B; Vázquez, Élida; Delgado, Ignacio; Zubiaurre-Elorza, Leire; Macaya, Alfons; Póo, Pilar; Meléndez-Plumed, Mar; Junqué, Carme; Boyd, Roslyn; Pueyo, Roser

2017-01-01

Dyskinetic cerebral palsy (CP) is one of the most disabling motor types of CP and has been classically associated with injury to the basal ganglia and thalamus. Although cognitive dysfunction is common in CP, there is a paucity of published quantitative analyses investigating the relationship between white matter (WM) microstructure and cognition in this CP type. This study aims (1) to compare brain WM microstructure between people with dyskinetic CP and healthy controls, (2) to identify brain regions where WM microstructure is related to intelligence and (3) to identify brain regions where WM microstructure is related to executive function in people with dyskinetic CP and (4) to identify brain regions where the correlations are different between controls and people with CP in IQ and executive functions. Thirty-three participants with dyskinetic CP (mean ± SD age: 24.42 ± 12.61, 15 female) were age and sex matched with 33 controls. Participants underwent a comprehensive neuropsychological battery to assess intelligence quotient (IQ) and four executive function domains (attentional control, cognitive flexibility, goal setting and information processing). Diffusion weighted MRI scans were acquired at 3T. Voxel-based whole brain groupwise analyses were used to compare fractional anisotropy (FA) and of the CP group to the matched controls using a general lineal model. Further general linear models were used to identify regions where white matter FA correlated with IQ and each of the executive function domains. White matter FA was significantly reduced in the CP group in all cerebral lobes, predominantly in regions connected with the parietal and to a lesser extent the temporal lobes. There was no significant correlation between IQ or any of the four executive function domains and WM microstructure in the control group. In participants with CP, lower IQ was associated with lower FA in all cerebral lobes, predominantly in locations that also showed reduced FA compared to controls. Attentional control, goal setting and information processing did not correlate with WM microstructure in the CP group. Cognitive flexibility was associated with FA in regions known to contain connections with the frontal lobe (such as the superior longitudinal fasciculus and cingulum) as well as regions not known to contain tracts directly connected with the frontal lobe (such as the posterior corona radiata, posterior thalamic radiation, retrolenticular part of internal capsule, tapetum, body and splenium of corpus callosum). The widespread loss in the integrity of WM tissue is mainly located in the parietal lobe and related to IQ in dyskinetic CP. Unexpectedly, executive functions are only related with WM microstructure in regions containing fronto-cortical and posterior cortico-subcortical pathways, and not being specifically related to the state of fronto-striatal pathways which might be due to brain reorganization. Further studies of this nature may improve our understanding of the neurobiological bases of cognitive impairments after early brain insult.

Structural isoforms of the circadian neuropeptide PDF expressed in the optic lobes of the cricket Gryllus bimaculatus: immunocytochemical evidence from specific monoclonal antibodies.

PubMed

Honda, Takeshi; Matsushima, Ayami; Sumida, Kazunori; Chuman, Yoshiro; Sakaguchi, Kazuyasu; Onoue, Hitoshi; Meinertzhagen, Ian A; Shimohigashi, Yasuyuki; Shimohigashi, Miki

2006-11-20

Pigment-dispersing factor (PDF) is an 18-mer peptide that acts as a principal neurotransmitter of the insect circadian clock. Our previous study, utilizing anti-Uca beta-PDH polyclonal antibody (pAb) to immunolabel the optic lobe of the cricket Gryllus bimaculatus, suggested the existence of an alternative PDF-like peptide in the outer cells of the first neuropile, or lamina (La), which were much less immunoreactive than the inner cells of the second neuropile, the medulla (Me). To obtain structural information about such a PDF-like peptide, we prepared 10 anti-Gryllus PDF monoclonal (mAb) and pAb antibodies and analyzed their detailed epitope specificities. The PDFMe and PDFLa inner cells and their axonal projections were clearly immunoreactive to all these antibodies, revealing the widespread immunocytochemical organization of the PDF system in the optic lobe, as seen previously with anti-Uca beta-PDH pAb and anti-Gryllus PDF mAb, the epitope structures of which were also clarified in this study. The lamina outer cells, which we found lacked a target pdf mRNA, displayed specific immunoreactivities, indicating that the cells contain a distinct PDF-like peptide possessing both N- and C-terminal structures. These cells were not immunolabeled by some other monoclonal antibodies, however, implying that the PDFLa outer cells have a PDF isoform peptide devoid of Asn at positions 6 and 16. This isoform was also identified in a varicose arborization in the lamina. These results suggest not only the structure of the peptide, but also the possibility of additional functions of this novel PDF isoform.

Familial temporal lobe epilepsy due to focal cortical dysplasia type IIIa.

PubMed

Fabera, Petr; Krijtova, Hana; Tomasek, Martin; Krysl, David; Zamecnik, Josef; Mohapl, Milan; Jiruska, Premysl; Marusic, Petr

2015-09-01

Focal cortical dysplasia (FCD) represents a common cause of refractory epilepsy. It is considered a sporadic disorder, but its occasional familial occurrence suggests the involvement of genetic mechanisms. Siblings with intractable epilepsy were referred for epilepsy surgery evaluation. Both patients were examined using video-EEG monitoring, MRI examination and PET imaging. They underwent left anteromedial temporal lobe resection. Electroclinical features pointed to left temporal lobe epilepsy and MRI examination revealed typical signs of left-sided hippocampal sclerosis and increased white matter signal intensity in the left temporal pole. PET examination confirmed interictal hypometabolism in the left temporal lobe. Histopathological examination of resected tissue demonstrated the presence FCD type IIIa, i.e. hippocampal sclerosis and focal cortical dysplasia in the left temporal pole. We present a unique case of refractory mesial temporal lobe epilepsy in siblings, characterized by an identical clinical profile and histopathology of FCD type IIIa, who were successfully treated by epilepsy surgery. The presence of such a high concordance between the clinical and morphological data, together with the occurrence of epilepsy and febrile seizures in three generations of the family pedigree points towards a possible genetic nature of the observed FCD type IIIa. Copyright © 2015 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.

Chandra Observation of the WAT Radio Source/ICM Interaction in Abell 623

NASA Astrophysics Data System (ADS)

Anand, Gagandeep; Blanton, Elizabeth L.; Randall, Scott W.; Paterno-Mahler, Rachel; Douglass, Edmund

2017-01-01

Galaxy clusters are important objects for studying the physics of the intracluster medium (ICM), galaxy formation and evolution, and cosmological parameters. Clusters containing wide-angle tail (WAT) radio sources are particularly valuable for studies of the interaction between these sources and the surrounding ICM. These sources are thought to form when the ram pressure from the ICM caused by the relative motion between the host radio galaxy and the cluster bends the radio lobes into a distinct wide-angle morphology. We present our results from the analysis of a Chandra observation of the nearby WAT hosting galaxy cluster Abell 623. A clear decrement in X-ray emission is coincident with the southern radio lobe, consistent with being a cavity carved out by the radio source. We present profiles of surface brightness, temperature, density, and pressure and find evidence for a possible shock. Based on the X-ray pressure in the vicinity of the radio lobes and assumptions about the content of the lobes, we estimate the relative ICM velocity required to bend the lobes into the observed angle. We also present spectral model fits to the overall diffuse cluster emission and see no strong signature for a cool core. The sum of the evidence indicates that Abell 623 may be undergoing a large scale cluster-cluster merger.

Predictors of pneumothorax following endoscopic valve therapy in patients with severe emphysema.

PubMed

Gompelmann, Daniela; Lim, Hyun-Ju; Eberhardt, Ralf; Gerovasili, Vasiliki; Herth, Felix Jf; Heussel, Claus Peter; Eichinger, Monika

2016-01-01

Endoscopic valve implantation is an effective treatment for patients with advanced emphysema. Despite the minimally invasive procedure, valve placement is associated with risks, the most common of which is pneumothorax. This study was designed to identify predictors of pneumothorax following endoscopic valve implantation. Preinterventional clinical measures (vital capacity, forced expiratory volume in 1 second, residual volume, total lung capacity, 6-minute walk test), qualitative computed tomography (CT) parameters (fissure integrity, blebs/bulla, subpleural nodules, pleural adhesions, partial atelectasis, fibrotic bands, emphysema type) and quantitative CT parameters (volume and low attenuation volume of the target lobe and the ipsilateral untreated lobe, target air trapping, ipsilateral lobe volume/hemithorax volume, collapsibility of the target lobe and the ipsilateral untreated lobe) were retrospectively evaluated in patients who underwent endoscopic valve placement (n=129). Regression analysis was performed to compare those who developed pneumothorax following valve therapy (n=46) with those who developed target lobe volume reduction without pneumothorax (n=83). Low attenuation volume% of ipsilateral untreated lobe (odds ratio [OR] =1.08, P=0.001), ipsilateral untreated lobe volume/hemithorax volume (OR =0.93, P=0.017), emphysema type (OR =0.26, P=0.018), pleural adhesions (OR =0.33, P=0.012) and residual volume (OR =1.58, P=0.012) were found to be significant predictors of pneumothorax. Fissure integrity (OR =1.16, P=0.075) and 6-minute walk test (OR =1.05, P=0.077) were also indicative of pneumothorax. The model including the aforementioned parameters predicted whether a patient would experience a pneumothorax 84% of the time (area under the curve =0.84). Clinical and CT parameters provide a promising tool to effectively identify patients at high risk of pneumothorax following endoscopic valve therapy.

Predictors of pneumothorax following endoscopic valve therapy in patients with severe emphysema

PubMed Central

Gompelmann, Daniela; Lim, Hyun-ju; Eberhardt, Ralf; Gerovasili, Vasiliki; Herth, Felix JF; Heussel, Claus Peter; Eichinger, Monika

2016-01-01

Background Endoscopic valve implantation is an effective treatment for patients with advanced emphysema. Despite the minimally invasive procedure, valve placement is associated with risks, the most common of which is pneumothorax. This study was designed to identify predictors of pneumothorax following endoscopic valve implantation. Methods Preinterventional clinical measures (vital capacity, forced expiratory volume in 1 second, residual volume, total lung capacity, 6-minute walk test), qualitative computed tomography (CT) parameters (fissure integrity, blebs/bulla, subpleural nodules, pleural adhesions, partial atelectasis, fibrotic bands, emphysema type) and quantitative CT parameters (volume and low attenuation volume of the target lobe and the ipsilateral untreated lobe, target air trapping, ipsilateral lobe volume/hemithorax volume, collapsibility of the target lobe and the ipsilateral untreated lobe) were retrospectively evaluated in patients who underwent endoscopic valve placement (n=129). Regression analysis was performed to compare those who developed pneumothorax following valve therapy (n=46) with those who developed target lobe volume reduction without pneumothorax (n=83). Finding Low attenuation volume% of ipsilateral untreated lobe (odds ratio [OR] =1.08, P=0.001), ipsilateral untreated lobe volume/hemithorax volume (OR =0.93, P=0.017), emphysema type (OR =0.26, P=0.018), pleural adhesions (OR =0.33, P=0.012) and residual volume (OR =1.58, P=0.012) were found to be significant predictors of pneumothorax. Fissure integrity (OR =1.16, P=0.075) and 6-minute walk test (OR =1.05, P=0.077) were also indicative of pneumothorax. The model including the aforementioned parameters predicted whether a patient would experience a pneumothorax 84% of the time (area under the curve =0.84). Interpretation Clinical and CT parameters provide a promising tool to effectively identify patients at high risk of pneumothorax following endoscopic valve therapy. PMID:27536088

Genetic mapping of the LOBED LEAF 1 (ClLL1) gene to a 127.6-kb region in watermelon (Citrullus lanatus L.)

PubMed Central

Wei, Chunhua; Chen, Xiner; Wang, Zhongyuan; Liu, Qiyan; Li, Hao; Zhang, Yong; Ma, Jianxiang; Yang, Jianqiang

2017-01-01

The lobed leaf character is a unique morphologic trait in crops, featuring many potential advantages for agricultural productivity. Although the majority of watermelon varieties feature lobed leaves, the genetic factors responsible for lobed leaf formation remain elusive. The F2:3 leaf shape segregating population offers the opportunity to study the underlying mechanism of lobed leaf formation in watermelon. Genetic analysis revealed that a single dominant allele (designated ClLL1) controlled the lobed leaf trait. A large-sized F3:4 population derived from F2:3 individuals was used to map ClLL1. A total of 5,966 reliable SNPs and indels were identified genome-wide via a combination of BSA and RNA-seq. Using the validated SNP and indel markers, the location of ClLL1 was narrowed down to a 127.6-kb region between markers W08314 and W07061, containing 23 putative ORFs. Expression analysis via qRT-PCR revealed differential expression patterns (fold-changes above 2-fold or below 0.5-fold) of three ORFs (ORF3, ORF11, and ORF18) between lobed and non-lobed leaf plants. Based on gene annotation and expression analysis, ORF18 (encoding an uncharacterized protein) and ORF22 (encoding a homeobox-leucine zipper-like protein) were considered as most likely candidate genes. Furthermore, sequence analysis revealed no polymorphisms in cDNA sequences of ORF18; however, two notable deletions were identified in ORF22. This study is the first report to map a leaf shape gene in watermelon and will facilitate cloning and functional characterization of ClLL1 in future studies. PMID:28704497

Genetic mapping of the LOBED LEAF 1 (ClLL1) gene to a 127.6-kb region in watermelon (Citrullus lanatus L.).

PubMed

Wei, Chunhua; Chen, Xiner; Wang, Zhongyuan; Liu, Qiyan; Li, Hao; Zhang, Yong; Ma, Jianxiang; Yang, Jianqiang; Zhang, Xian

2017-01-01

The lobed leaf character is a unique morphologic trait in crops, featuring many potential advantages for agricultural productivity. Although the majority of watermelon varieties feature lobed leaves, the genetic factors responsible for lobed leaf formation remain elusive. The F2:3 leaf shape segregating population offers the opportunity to study the underlying mechanism of lobed leaf formation in watermelon. Genetic analysis revealed that a single dominant allele (designated ClLL1) controlled the lobed leaf trait. A large-sized F3:4 population derived from F2:3 individuals was used to map ClLL1. A total of 5,966 reliable SNPs and indels were identified genome-wide via a combination of BSA and RNA-seq. Using the validated SNP and indel markers, the location of ClLL1 was narrowed down to a 127.6-kb region between markers W08314 and W07061, containing 23 putative ORFs. Expression analysis via qRT-PCR revealed differential expression patterns (fold-changes above 2-fold or below 0.5-fold) of three ORFs (ORF3, ORF11, and ORF18) between lobed and non-lobed leaf plants. Based on gene annotation and expression analysis, ORF18 (encoding an uncharacterized protein) and ORF22 (encoding a homeobox-leucine zipper-like protein) were considered as most likely candidate genes. Furthermore, sequence analysis revealed no polymorphisms in cDNA sequences of ORF18; however, two notable deletions were identified in ORF22. This study is the first report to map a leaf shape gene in watermelon and will facilitate cloning and functional characterization of ClLL1 in future studies.

Variability in the impairment of recognition memory in patients with frontal lobe lesions.

PubMed

Bastin, Christine; Van der Linden, Martial; Lekeu, Françoise; Andrés, Pilar; Salmon, Eric

2006-10-01

Fourteen patients with frontal lobe lesions and 14 normal subjects were tested on a recognition memory task that required discriminating between target words, new words that are synonyms of the targets and unrelated distractors. A deficit was found in 12 of the patients. Moreover, three different patterns of recognition impairment were identified: (I) poor memory for targets, (II) normal hits but increased false recognitions for both types of distractors, (III) normal hit rates, but increased false recognitions for synonyms only. Differences in terms of location of the damage and behavioral characteristics between these subgroups were examined. An encoding deficit was proposed to explain the performance of patients in subgroup I. The behavioral patterns of the patients in subgroups II and III could be interpreted as deficient post-retrieval verification processes and an inability to recollect item-specific information, respectively.

Peri-ictal ECG changes in childhood epilepsy: implications for detection systems.

PubMed

Jansen, Katrien; Varon, Carolina; Van Huffel, Sabine; Lagae, Lieven

2013-10-01

Early detection of seizures could reduce associated morbidity and mortality and improve the quality of life of patients with epilepsy. In this study, the aim was to investigate whether ictal tachycardia is present in focal and generalized epileptic seizures in children. We sought to predict in which type of seizures tachycardia can be identified before actual seizure onset. Electrocardiogram segments in 80 seizures were analyzed in time and frequency domains before and after the onset of epileptic seizures on EEG. These ECG parameters were analyzed to find the most informative ones that can be used for seizure detection. The algorithm of Leutmezer et al. was used to find the temporal relationship between the change in heart rate and seizure onset. In the time domain, the mean RR shows a significant difference before compared to after onset of the seizure in focal seizures. This can be observed in temporal lobe seizures as well as frontal lobe seizures. Calculation of mean RR interval has a high specificity for detection of ictal heart rate changes. Preictal heart rate changes are observed in 70% of the partial seizures. Ictal heart rate changes are present only in partial seizures in this childhood epilepsy study. The changes can be observed in temporal lobe seizures as well as in frontal lobe seizures. Heart rate changes precede seizure onset in 70% of the focal seizures, making seizure detection and closed-loop systems a possible therapeutic alternative in the population of children with refractory epilepsy. © 2013.

Dosimetric evaluation of the feasibility of stereotactic body radiotherapy for primary lung cancer with lobe-specific selective elective nodal irradiation.

PubMed

Komatsu, Tetsuya; Kunieda, Etsuo; Kitahara, Tadashi; Akiba, Takeshi; Nagao, Ryuta; Fukuzawa, Tsuyoshi

2016-01-01

More than 10% of all patients treated with stereotactic body radiotherapy (SBRT) for primary lung cancer develop regional lymph node recurrence. We evaluated the dosimetric feasibility of SBRT with lobe-specific selective elective nodal irradiation (ENI) on dose-volume histograms. A total of 21 patients were treated with SBRT for Stage I primary lung cancer between January 2010 and June 2012 at our institution. The extents of lobe-specific selective ENI fields were determined with reference to prior surgical reports. The ENI fields included lymph node stations (LNS) 3 + 4 + 11 for the right upper lobe tumors, LNS 7 + 11 for the right middle or lower lobe tumors, LNS 5 + 11 for the left upper lobe tumors, and LNS 7 + 11 for the left lower lobe tumors. A composite plan was generated by combining the ENI plan and the SBRT plan and recalculating for biologically equivalent doses of 2 Gy per fraction, using a linear quadratic model. The V20 of the lung, D(1cm3) of the spinal cord, D(1cm3) and D(10cm3) of the esophagus and D(10cm3) of the tracheobronchial wall were evaluated. Of the 21 patients, nine patients (43%) could not fulfill the dose constraints. In all these patients, the distance between the planning target volume (PTV) of ENI (PTVeni) and the PTV of SBRT (PTVsrt) was ≤2.0 cm. Of the three patients who developed regional metastasis, two patients had isolated lymph node failure, and the lymph node metastasis was included within the ENI field. When the distance between the PTVeni and PTVsrt is >2.0 cm, SBRT with selective ENI may therefore dosimetrically feasible. © The Author 2015. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology.

Pore-fluid chemistry along the main axis of an active lobe at the Congo deep-sea fan

NASA Astrophysics Data System (ADS)

Croguennec, C.; Ruffine, L.; Guyader, V.; Le Bruchec, J.; Ruesch, B.; Caprais, J.; Cathalot, C.; de Prunelé, A.; Germain, Y.; Bollinger, C.; Dennielou, B.; Olu, K.; Rabouille, C.

2013-12-01

The distal lobes of the Congo deep-sea fan constitute a unique in situ laboratory to study early diagenesis of marine sediments. They are located at water depth of about 5000 m and result from the deposition of sediment transported by turbidity currents along the channel-levee systems and submarine canyon connected to the Congo River. Thus, a huge amount of organic matter, transported from the river to the lobes, undergoes decomposition processes involving different oxidants present within the sedimentary column. This drastically changes the chemistry of the pore fluids, allowing the occurence of a succession of biogeochemical processes. The present study is part of an ongoing project which aims at better understanding the role and the fate of organic matter transported to the lobe systems, as well as its implication in the distribution of the living communities encountered there. Thus, pore fluids have been sampled from 8 Calypso cores in order to determine the concentration of dissolved elements. Five sites have been investigated: four of them are located along the main axis of a currently active lobe, the last one being located on a lobe disconnected from the chenals. The analyses of methane, major (Cl, SO4, Mg, Ca, K, Na) and minor (Sr, Ba, B, Li, Mn) elements have been carried out along with total alkalinity determination. The resulting profiles show a highly heterogeneous pore-fluid chemistry. Sulphate concentration near the seawater/sediment interface varies from 3 to 29 mM, indicating intense sulphate reduction. Surprisingly the lowest values are found at the site which is disconnected from the active lobe. The manganese cycle is well defined for all cores. The core recovered at the more distal lobe exhibits very peculiar pore-fluid profiles which are likely related to a geological event, most likely sediment slide and remobilization. References: Babonneau, N., Savoye, B., Cremer, M. & Klein, B., 2002. Morphology and architecture of the present canyon and channel system of the Zaire deep-sea fan, Mar. Pet. Geol., 19, 445-467. Savoye, B., Babonneau, N., Dennielou, B. & Bez, M., 2009. Geological overview of the Angola-Congo margin, the Congo deep-sea fan and its submarine valleys, Deep-Sea Res. Part II-Top. Stud. Oceanogr., 56, 2169-2182. Vangriesheim, A., Khripounoff, A. & Crassous, P., 2009. Turbidity events observed in situ along the Congo submarine channel, Deep-Sea Res. Part II-Top. Stud. Oceanogr., 56, 2208-2222. Zabel, M. & Schulz, H.D., 2001. Importance of submarine landslides for non-steady state conditions in pore water systems - lower Zaire (Congo) deep-sea fan, Mar. Geol., 176, 87-99.

Association of Hippocampal Substructure Resting-State Functional Connectivity with Memory Performance in Older Adults.

PubMed

Smagula, Stephen F; Karim, Helmet T; Rangarajan, Anusha; Santos, Fernando Pasquini; Wood, Sossena C; Santini, Tales; Jakicic, John M; Reynolds, Charles F; Cameron, Judy L; Vallejo, Abbe N; Butters, Meryl A; Rosano, Caterina; Ibrahim, Tamer S; Erickson, Kirk I; Aizenstein, Howard J

2018-06-01

Hippocampal hyperactivation marks preclinical dementia pathophysiology, potentially due to differences in the connectivity of specific medial temporal lobe structures. Our aims were to characterize the resting-state functional connectivity of medial temporal lobe sub-structures in older adults, and evaluate whether specific substructural (rather than global) functional connectivity relates to memory function. In 15 adults (mean age: 69 years), we evaluated the resting state functional connectivity of medial temporal lobe substructures: dentate/Cornu Ammonis (CA) 4, CA1, CA2/3, subiculum, the molecular layer, entorhinal cortex, and parahippocampus. We used 7-Tesla susceptibility weighted imaging and magnetization-prepared rapid gradient echo sequences to segment substructures of the hippocampus, which were used as structural seeds for examining functional connectivity in a resting BOLD sequence. We then assessed correlations between functional connectivity with memory performance (short and long delay free recall on the California Verbal Learning Test [CVLT]). All the seed regions had significant connectivity within the temporal lobe (including the fusiform, temporal, and lingual gyri). The left CA1 was the only seed with significant functional connectivity to the amygdala. The left entorhinal cortex was the only seed to have significant functional connectivity with frontal cortex (anterior cingulate and superior frontal gyrus). Only higher left dentate-left lingual connectivity was associated with poorer CVLT performance (Spearman r = -0.81, p = 0.0003, Benjamini-Hochberg false discovery rate: 0.01) after multiple comparison correction. Rather than global hyper-connectivity of the medial temporal lobe, left dentate-lingual connectivity may provide a specific assay of medial temporal lobe hyper-connectivity relevant to memory in aging. Copyright © 2018 American Association for Geriatric Psychiatry. Published by Elsevier Inc. All rights reserved.

The effect of white matter hyperintensities on verbal memory: Mediation by temporal lobe atrophy.

PubMed

Swardfager, Walter; Cogo-Moreira, Hugo; Masellis, Mario; Ramirez, Joel; Herrmann, Nathan; Edwards, Jodi D; Saleem, Mahwesh; Chan, Parco; Yu, Di; Nestor, Sean M; Scott, Christopher J M; Holmes, Melissa F; Sahlas, Demetrios J; Kiss, Alexander; Oh, Paul I; Strother, Stephen C; Gao, Fuqiang; Stefanovic, Bojana; Keith, Julia; Symons, Sean; Swartz, Richard H; Lanctôt, Krista L; Stuss, Donald T; Black, Sandra E

2018-02-20

To determine the relationship between white matter hyperintensities (WMH) presumed to indicate disease of the cerebral small vessels, temporal lobe atrophy, and verbal memory deficits in Alzheimer disease (AD) and other dementias. We recruited groups of participants with and without AD, including strata with extensive WMH and minimal WMH, into a cross-sectional proof-of-principle study (n = 118). A consecutive case series from a memory clinic was used as an independent validation sample (n = 702; Sunnybrook Dementia Study; NCT01800214). We assessed WMH volume and left temporal lobe atrophy (measured as the brain parenchymal fraction) using structural MRI and verbal memory using the California Verbal Learning Test. Using path modeling with an inferential bootstrapping procedure, we tested an indirect effect of WMH on verbal recall that depends sequentially on temporal lobe atrophy and verbal learning. In both samples, WMH predicted poorer verbal recall, specifically due to temporal lobe atrophy and poorer verbal learning (proof-of-principle -1.53, 95% bootstrap confidence interval [CI] -2.45 to -0.88; and confirmation -0.66, 95% CI [-0.95 to -0.41] words). This pathway was significant in subgroups with (-0.20, 95% CI [-0.38 to -0.07] words, n = 363) and without (-0.71, 95% CI [-1.12 to -0.37] words, n = 339) AD. Via the identical pathway, WMH contributed to deficits in recognition memory (-1.82%, 95% CI [-2.64% to -1.11%]), a sensitive and specific sign of AD. Across dementia syndromes, WMH contribute indirectly to verbal memory deficits considered pathognomonic of Alzheimer disease, specifically by contributing to temporal lobe atrophy. © 2018 American Academy of Neurology.

Cognitive functioning in bilateral perisylvian polymicrogyria (BPP): clinical and radiological correlations.

PubMed

Jansen, An C; Leonard, Gabriel; Bastos, Alexandre C; Esposito-Festen, Josée E; Tampieri, Donatella; Watkins, Kate; Andermann, Frederick; Andermann, Eva

2005-05-01

Bilateral perisylvian polymicrogyria (BPP) is a malformation of cortical development, frequently associated with severe dysarthria or anarthria. BPP patients are therefore often labeled as severely retarded, but a detailed neuropsychological profile has not been reported to date. In a series of 14 patients, we demonstrated that only a minority had extremely low intelligence, and that some aspects of cognitive function correlated with the extent of the cortical disorganization. Early age at seizure onset correlated positively with Performance IQ scores (P<0.05) and negatively with the extent of the lesion (P<0.01), reflecting that patients with more severe BPP are more likely to have early seizure onset, resulting in greater interference with ongoing cognitive development. Receptive and expressive language skills were found to be equally poor. Frontal lobe function and memory abilities were relatively well preserved, suggesting that the observed cognitive profiles were related, at least in part, to specific areas of cortical dysfunction and not only to global dysfunction.

Distinct anatomical subtypes of the behavioural variant of frontotemporal dementia: a cluster analysis study.

PubMed

Whitwell, Jennifer L; Przybelski, Scott A; Weigand, Stephen D; Ivnik, Robert J; Vemuri, Prashanthi; Gunter, Jeffrey L; Senjem, Matthew L; Shiung, Maria M; Boeve, Bradley F; Knopman, David S; Parisi, Joseph E; Dickson, Dennis W; Petersen, Ronald C; Jack, Clifford R; Josephs, Keith A

2009-11-01

The behavioural variant of frontotemporal dementia is a progressive neurodegenerative syndrome characterized by changes in personality and behaviour. It is typically associated with frontal lobe atrophy, although patterns of atrophy are heterogeneous. The objective of this study was to examine case-by-case variability in patterns of grey matter atrophy in subjects with the behavioural variant of frontotemporal dementia and to investigate whether behavioural variant of frontotemporal dementia can be divided into distinct anatomical subtypes. Sixty-six subjects that fulfilled clinical criteria for a diagnosis of the behavioural variant of frontotemporal dementia with a volumetric magnetic resonance imaging scan were identified. Grey matter volumes were obtained for 26 regions of interest, covering frontal, temporal and parietal lobes, striatum, insula and supplemental motor area, using the automated anatomical labelling atlas. Regional volumes were divided by total grey matter volume. A hierarchical agglomerative cluster analysis using Ward's clustering linkage method was performed to cluster the behavioural variant of frontotemporal dementia subjects into different anatomical clusters. Voxel-based morphometry was used to assess patterns of grey matter loss in each identified cluster of subjects compared to an age and gender-matched control group at P < 0.05 (family-wise error corrected). We identified four potentially useful clusters with distinct patterns of grey matter loss, which we posit represent anatomical subtypes of the behavioural variant of frontotemporal dementia. Two of these subtypes were associated with temporal lobe volume loss, with one subtype showing loss restricted to temporal lobe regions (temporal-dominant subtype) and the other showing grey matter loss in the temporal lobes as well as frontal and parietal lobes (temporofrontoparietal subtype). Another two subtypes were characterized by a large amount of frontal lobe volume loss, with one subtype showing grey matter loss in the frontal lobes as well as loss of the temporal lobes (frontotemporal subtype) and the other subtype showing loss relatively restricted to the frontal lobes (frontal-dominant subtype). These four subtypes differed on clinical measures of executive function, episodic memory and confrontation naming. There were also associations between the four subtypes and genetic or pathological diagnoses which were obtained in 48% of the cohort. The clusters did not differ in behavioural severity as measured by the Neuropsychiatric Inventory; supporting the original classification of the behavioural variant of frontotemporal dementia in these subjects. Our findings suggest behavioural variant of frontotemporal dementia can therefore be subdivided into four different anatomical subtypes.

Ecdysone-dependent and ecdysone-independent programmed cell death in the developing optic lobe of Drosophila.

PubMed

Hara, Yusuke; Hirai, Keiichiro; Togane, Yu; Akagawa, Hiromi; Iwabuchi, Kikuo; Tsujimura, Hidenobu

2013-02-01

The adult optic lobe of Drosophila develops from the primordium during metamorphosis from mid-3rd larval stage to adult. Many cells die during development of the optic lobe with a peak of the number of dying cells at 24 h after puparium formation (h APF). Dying cells were observed in spatio-temporal specific clusters. Here, we analyzed the function of a component of the insect steroid hormone receptor, EcR, in this cell death. We examined expression patterns of two EcR isoforms, EcR-A and EcR-B1, in the optic lobe. Expression of each isoform altered during development in isoform-specific manner. EcR-B1 was not expressed in optic lobe neurons from 0 to 6h APF, but was expressed between 9 and 48 h APF and then disappeared by 60 h APF. In each cortex, its expression was stronger in older glia-ensheathed neurons than in younger ones. EcR-B1 was also expressed in some types of glia. EcR-A was expressed in optic lobe neurons and many types of glia from 0 to 60 h APF in a different pattern from EcR-B1. Then, we genetically analyzed EcR function in the optic lobe cell death. At 0 h APF, the optic lobe cell death was independent of any EcR isoforms. In contrast, EcR-B1 was required for most optic lobe cell death after 24 h APF. It was suggested that cell death cell-autonomously required EcR-B1 expressed after puparium formation. βFTZ-F1 was also involved in cell death in many dying-cell clusters, but not in some of them at 24 h APF. Altogether, the optic lobe cell death occurred in ecdysone-independent manner at prepupal stage and ecdysone-dependent manner after 24 h APF. The acquisition of ecdysone-dependence was not directly correlated with the initiation or increase of EcR-B1 expression. Copyright © 2012 Elsevier Inc. All rights reserved.

Temporal lobe epilepsy in a cat with a pyriform lobe oligodendroglioma and hippocampal necrosis.

PubMed

Vanhaesebrouck, An E; Posch, Barbara; Baker, Sam; Plessas, Ioannis N; Palmer, Anthony C; Constantino-Casas, Fernando

2012-12-01

A 14-year-old male domestic shorthair cat presented with an acute onset of aggressive behaviour, fear and hypersalivation. Neurological examination revealed bilateral mydriasis and left-sided facial twitching and hemiparesis. Magnetic resonance imaging (MRI) showed moderate bilateral symmetrical T2-hyperintensity along the entire hippocampus and bilateral asymmetric T2-hyperintensity in the pyriform lobes. Marked bilateral contrast enhancement of the hippocampus was evident on post-contrast T1-weighted images. The partial complex seizures were refractory to medical treatment and the cat was euthanased 4 days after admission. The clinical and MRI findings were consistent with feline hippocampal necrosis (FHN). On histopathology, neuronal necrosis and astrocytosis were present in the hippocampi and pyriform lobes. In addition, an oligodendroglioma was detected in the right pyriform lobe. Contrary to previous reports of FHN in which no underlying cause could be identified, we believe that in this case the seizure focus arose from a neoplastic lesion within the right pyriform lobe. This unique case report represents the so-called 'dual pathology' of temporal lobe epilepsy in humans, in which an extrahippocampal lesion within the temporal lobe results in hippocampal sclerosis.

Linking DMN connectivity to episodic memory capacity: What can we learn from patients with medial temporal lobe damage?

PubMed Central

McCormick, Cornelia; Protzner, Andrea B.; Barnett, Alexander J.; Cohn, Melanie; Valiante, Taufik A.; McAndrews, Mary Pat

2014-01-01

Computational models predict that focal damage to the Default Mode Network (DMN) causes widespread decreases and increases of functional DMN connectivity. How such alterations impact functioning in a specific cognitive domain such as episodic memory remains relatively unexplored. Here, we show in patients with unilateral medial temporal lobe epilepsy (mTLE) that focal structural damage leads indeed to specific patterns of DMN functional connectivity alterations, specifically decreased connectivity between both medial temporal lobes (MTLs) and the posterior part of the DMN and increased intrahemispheric anterior–posterior connectivity. Importantly, these patterns were associated with better and worse episodic memory capacity, respectively. These distinct patterns, shown here for the first time, suggest that a close dialogue between both MTLs and the posterior components of the DMN is required to fully express the extensive repertoire of episodic memory abilities. PMID:25068108

Visual interhemispheric communication and callosal connections of the occipital lobes.

PubMed

Berlucchi, Giovanni

2014-07-01

Callosal connections of the occipital lobes, coursing in the splenium of the corpus callosum, have long been thought to be crucial for interactions between the cerebral hemispheres in vision in both experimental animals and humans. Yet the callosal connections of the temporal and parietal lobes appear to have more important roles than those of the occipital callosal connections in at least some high-order interhemispheric visual functions. The partial intermixing and overlap of temporal, parietal and occipital callosal connections within the splenium has made it difficult to attribute the effects of splenial pathological lesions or experimental sections to splenial components specifically related to select cortical areas. The present review describes some current contributions from the modern techniques for the tracking of commissural fibers within the living human brain to the tentative assignation of specific visual functions to specific callosal tracts, either occipital or extraoccipital. Copyright © 2013 Elsevier Ltd. All rights reserved.

Frontal lobe seizures: from clinical semiology to localization.

PubMed

Bonini, Francesca; McGonigal, Aileen; Trébuchon, Agnès; Gavaret, Martine; Bartolomei, Fabrice; Giusiano, Bernard; Chauvel, Patrick

2014-02-01

Frontal lobe seizures are difficult to characterize according to semiologic and electrical features. We wished to establish whether different semiologic subgroups can be identified and whether these relate to anatomic organization. We assessed all seizures from 54 patients with frontal lobe epilepsy that were explored with stereoelectroencephalography (SEEG) during presurgical evaluation. Semiologic features and concomitant intracerebral EEG changes were documented and quantified. These variables were examined using Principal Component Analysis and Cluster Analysis, and semiologic features correlated with anatomic localization. Four main groups of patients were identified according to semiologic features, and correlated with specific patterns of anatomic seizure localization. Group 1 was characterized clinically by elementary motor signs and involved precentral and premotor regions. Group 2 was characterized by a combination of elementary motor signs and nonintegrated gestural motor behavior, and involved both premotor and prefrontal regions. Group 3 was characterized by integrated gestural motor behavior with distal stereotypies and involved anterior lateral and medial prefrontal regions. Group 4 was characterized by seizures with fearful behavior and involved the paralimbic system (ventromedial prefrontal cortex ± anterior temporal structures). The groups were organized along a rostrocaudal axis, representing bands within a spectrum rather than rigid categories. The more anterior the seizure organization, the more likely was the occurrence of integrated behavior during seizures. Distal stereotypies were associated with the most anterior prefrontal localizations, whereas proximal stereotypies occurred in more posterior prefrontal regions. Meaningful categorization of frontal seizures in terms of semiology is possible and correlates with anatomic organization along a rostrocaudal axis, in keeping with current hypotheses of frontal lobe hierarchical organization. The proposed electroclinical categorization offers pointers as to the likely zone of organization of networks underlying semiologic production, thus aiding presurgical localization. Furthermore, analysis of ictal motor behavior in prefrontal seizures, including stereotypies, leads to deciphering the cortico-subcortical networks that produce such behaviors. Wiley Periodicals, Inc. © 2013 International League Against Epilepsy.

Cluster-specific small airway modeling for imaging-based CFD analysis of pulmonary air flow and particle deposition in COPD smokers

NASA Astrophysics Data System (ADS)

Haghighi, Babak; Choi, Jiwoong; Choi, Sanghun; Hoffman, Eric A.; Lin, Ching-Long

2017-11-01

Accurate modeling of small airway diameters in patients with chronic obstructive pulmonary disease (COPD) is a crucial step toward patient-specific CFD simulations of regional airflow and particle transport. We proposed to use computed tomography (CT) imaging-based cluster membership to identify structural characteristics of airways in each cluster and use them to develop cluster-specific airway diameter models. We analyzed 284 COPD smokers with airflow limitation, and 69 healthy controls. We used multiscale imaging-based cluster analysis (MICA) to classify smokers into 4 clusters. With representative cluster patients and healthy controls, we performed multiple regressions to quantify variation of airway diameters by generation as well as by cluster. The cluster 2 and 4 showed more diameter decrease as generation increases than other clusters. The cluster 4 had more rapid decreases of airway diameters in the upper lobes, while cluster 2 in the lower lobes. We then used these regression models to estimate airway diameters in CT unresolved regions to obtain pressure-volume hysteresis curves using a 1D resistance model. These 1D flow solutions can be used to provide the patient-specific boundary conditions for 3D CFD simulations in COPD patients. Support for this study was provided, in part, by NIH Grants U01-HL114494, R01-HL112986 and S10-RR022421.

High-Throughput Data of Circular RNA Profiles in Human Temporal Cortex Tissue Reveals Novel Insights into Temporal Lobe Epilepsy.

PubMed

Li, Jiaxin; Lin, Haijun; Sun, Zhenrong; Kong, Guanyi; Yan, Xu; Wang, Yujiao; Wang, Xiaoxuan; Wen, Yanhua; Liu, Xiang; Zheng, Hongkun; Jia, Mei; Shi, Zhongfang; Xu, Rong; Yang, Shaohua; Yuan, Fang

2018-01-01

Circular RNAs (circRNAs) are a class of long noncoding RNAs with a closed loop structure that regulate gene expression as microRNA sponges. CircRNAs are more enriched in brain tissue, but knowledge of the role of circRNAs in temporal lobe epilepsy (TLE) has remained limited. This study is the first to identify the global expression profiles and characteristics of circRNAs in human temporal cortex tissue from TLE patients. Temporal cortices were collected from 17 TLE patients and 17 non-TLE patients. Total RNA was isolated, and high-throughput sequencing was used to profile the transcriptome of dysregulated circRNAs. Quantitative PCR was performed for the validation of changed circRNAs. In total, 78983 circRNAs, including 15.29% known and 84.71% novel circRNAs, were detected in this study. Intriguingly, 442 circRNAs were differentially expressed between the TLE and non-TLE groups (fold change≥2.0 and FDR≤0.05). Of these circRNAs, 188 were up-regulated, and 254 were down-regulated in the TLE patient group. Eight circRNAs were validated by real-time PCR. Remarkably, circ-EFCAB2 was intensely up-regulated, while circ-DROSHA expression was significantly lower in the TLE group than in the non-TLE group (P<0.05). Bioinformatic analysis revealed that circ-EFCAB2 binds to miR-485-5p to increase the expression level of the ion channel CLCN6, while circ-DROSHA interacts with miR-1252-5p to decrease the expression level of ATP1A2. The dysregulations of circRNAs may reflect the pathogenesis of TLE and circ-EFCAB2 and circ-DROSHA might be potential therapeutic targets and biomarkers in TLE patients. © 2018 The Author(s). Published by S. Karger AG, Basel.

Frontal Lobe Contusion in Mice Chronically Impairs Prefrontal-Dependent Behavior

PubMed Central

Rosi, Susanna

2016-01-01

Traumatic brain injury (TBI) is a major cause of chronic disability in the world. Moderate to severe TBI often results in damage to the frontal lobe region and leads to cognitive, emotional, and social behavioral sequelae that negatively affect quality of life. More specifically, TBI patients often develop persistent deficits in social behavior, anxiety, and executive functions such as attention, mental flexibility, and task switching. These deficits are intrinsically associated with prefrontal cortex (PFC) functionality. Currently, there is a lack of analogous, behaviorally characterized TBI models for investigating frontal lobe injuries despite the prevalence of focal contusions to the frontal lobe in TBI patients. We used the controlled cortical impact (CCI) model in mice to generate a frontal lobe contusion and studied behavioral changes associated with PFC function. We found that unilateral frontal lobe contusion in mice produced long-term impairments to social recognition and reversal learning while having only a minor effect on anxiety and completely sparing rule shifting and hippocampal-dependent behavior. PMID:26964036

Painful Heat Reveals Hyperexcitability of the Temporal Pole in Interictal and Ictal Migraine States

PubMed Central

Moulton, E. A.; Becerra, L.; Maleki, N.; Pendse, G.; Tully, S.; Hargreaves, R.; Burstein, R.

2011-01-01

During migraine attacks, alterations in sensation accompanying headache may manifest as allodynia and enhanced sensitivity to light, sound, and odors. Our objective was to identify physiological changes in cortical regions in migraine patients using painful heat and functional magnetic resonance imaging (fMRI) and the structural basis for such changes using diffusion tensor imaging (DTI). In 11 interictal patients, painful heat threshold + 1°C was applied unilaterally to the forehead during fMRI scanning. Significantly greater activation was identified in the medial temporal lobe in patients relative to healthy subjects, specifically in the anterior temporal pole (TP). In patients, TP showed significantly increased functional connectivity in several brain regions relative to controls, suggesting that TP hyperexcitability may contribute to functional abnormalities in migraine. In 9 healthy subjects, DTI identified white matter connectivity between TP and pulvinar nucleus, which has been related to migraine. In 8 patients, fMRI activation in TP with painful heat was exacerbated during migraine, suggesting that repeated migraines may sensitize TP. This article investigates a nonclassical role of TP in migraineurs. Observed temporal lobe abnormalities may provide a basis for many of the perceptual changes in migraineurs and may serve as a potential interictal biomarker for drug efficacy. PMID:20562317

Bilingualism Alters Children's Frontal Lobe Functioning for Attentional Control

ERIC Educational Resources Information Center

Arredondo, Maria M.; Hu, Xiao-Su; Satterfield, Teresa; Kovelman, Ioulia

2017-01-01

Bilingualism is a typical linguistic experience, yet relatively little is known about its impact on children's cognitive and brain development. Theories of bilingualism suggest that early dual-language acquisition can improve children's cognitive abilities, specifically those relying on frontal lobe functioning. While behavioral findings present…

Utility of Neurodiagnostic Studies in the Diagnosis of Autoimmune Encephalitis in Children.

PubMed

Albert, Dara V; Pluto, Charles P; Weber, Amanda; Vidaurre, Jorge; Barbar-Smiley, Fatima; Abdul Aziz, Rabheh; Driest, Kyla; Bout-Tabaku, Sharon; Ruess, Lynne; Rusin, Jerome A; Morgan-Followell, Bethanie

2016-02-01

Autoimmune encephalitis is currently a clinical diagnosis without widely accepted diagnostic criteria, often leading to a delay in diagnosis. The utility of magnetic resonance imaging (MRI) and electroencephalography (EEG) in this disease is unknown. The objective of this study was to identify disease-specific patterns of neurodiagnostic studies (MRI and EEG) for autoimmune encephalitis in children. We completed a retrospective chart review of encephalopathic patients seen at a large pediatric hospital over a four year interval. Clinical presentation, autoantibody status, and MRI and EEG findings were identified and compared. Individuals with autoantibodies were considered "definite" cases, whereas those without antibodies or those with only thyroperoxidase antibodies were characterized as "suspected." Eighteen patients met the inclusion criteria and autoantibodies were identified in nine of these. The patients with definite autoimmune encephalitis had MRI abnormalities within limbic structures, most notably the anteromedial temporal lobes (56%). Only individuals with suspected disease had nontemporal lobe cortical lesions. Sixteen patients had an EEG and 13 (81%) of these were abnormal. The most common findings were abnormal background rhythm (63%), generalized slowing (50%), focal slowing (43%), and focal epileptiform discharges (31%). Sleep spindle abnormalities occurred in 38% of patients. There were no specific differences in the EEG findings between the definite and suspected cases. Focal EEG findings only correlated with a focal lesion on MRI in a single definite case. Pediatric patients with definite autoimmune encephalitis have a narrow spectrum of MRI abnormalities. Conversely, EEG abnormalities are mostly nonspecific. All patients in our cohort had abnormalities on one or both of these neurodiagnostic studies. Copyright © 2016 Elsevier Inc. All rights reserved.

Three-dimensional flow structure and patterns of bed shear stress in an evolving compound meander bend

USGS Publications Warehouse

Engel, Frank; Rhoads, Bruce L.

2016-01-01

Compound meander bends with multiple lobes of maximum curvature are common in actively evolving lowland rivers. Interaction among spatial patterns of mean flow, turbulence, bed morphology, bank failures and channel migration in compound bends is poorly understood. In this paper, acoustic Doppler current profiler (ADCP) measurements of the three-dimensional (3D) flow velocities in a compound bend are examined to evaluate the influence of channel curvature and hydrologic variability on the structure of flow within the bend. Flow structure at various flow stages is related to changes in bed morphology over the study timeframe. Increases in local curvature within the upstream lobe of the bend reduce outer bank velocities at morphologically significant flows, creating a region that protects the bank from high momentum flow and high bed shear stresses. The dimensionless radius of curvature in the upstream lobe is one-third less than that of the downstream lobe, with average bank erosion rates less than half of the erosion rates for the downstream lobe. Higher bank erosion rates within the downstream lobe correspond to the shift in a core of high velocity and bed shear stresses toward the outer bank as flow moves through the two lobes. These erosion patterns provide a mechanism for continued migration of the downstream lobe in the near future. Bed material size distributions within the bend correspond to spatial patterns of bed shear stress magnitudes, indicating that bed material sorting within the bend is governed by bed shear stress. Results suggest that patterns of flow, sediment entrainment, and planform evolution in compound meander bends are more complex than in simple meander bends. Moreover, interactions among local influences on the flow, such as woody debris, local topographic steering, and locally high curvature, tend to cause compound bends to evolve toward increasing planform complexity over time rather than stable configurations.

Systematic Review of Cognitive Function in Euthymic Bipolar Disorder and Pre-Surgical Temporal Lobe Epilepsy.

PubMed

Bostock, Emmanuelle C S; Kirkby, Kenneth C; Garry, Michael I; Taylor, Bruce V M

2017-01-01

Bipolar disorder (BD) and temporal lobe epilepsy (TLE) overlap in domains including epidemiology, treatment response, shared neurotransmitter involvement and temporal lobe pathology. Comparison of cognitive function in both disorders may indicate temporal lobe mediated processes relevant to BD. This systematic review examines neuropsychological test profiles in euthymic bipolar disorder type I (BD-I) and pre-surgical TLE and compares experimental designs used. A search of PubMed, PsychINFO, and Scopus using Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines was conducted. Inclusion criteria were comparison group or pre- to post-surgical patients; reported neuropsychological tests; participants aged 18-60 years. Fifty six studies met criteria: 27 BD-I; 29 TLE. Deficits in BD-I compared to healthy controls (HC) were in executive function, attention span and verbal memory. Deficits in TLE compared to HC were in executive function and memory. In the pre- to post-surgical comparisons, verbal memory in left temporal lobe (LTL) and, less consistently, visuospatial memory in right temporal lobe (RTL) epilepsy declined following surgery. BD-I studies used comprehensive test batteries in well-defined euthymic patients compared to matched HC groups. TLE studies used convenience samples pre- to post-surgery, comparing LTL and RTL subgroups, few included comparisons to HC (5 studies). TLE studies typically examined a narrow range of known temporal lobe-mediated neuropsychological functions, particularly verbal and visuospatial memory. Both disorders exhibit deficits in executive function and verbal memory suggestive of both frontal and temporal lobe involvement. However, deficits in TLE are measured pre- to post-surgery and not controlled at baseline pre-surgery. Further research involving a head-to-head comparison of the two disorders on a broad range of neuropsychological tests is needed to clarify the nature and extent of cognitive deficits and potential overlaps.

Herpes zoster chronification to postherpetic neuralgia induces brain activity and grey matter volume change

PubMed Central

Cao, Song; Qin, Bangyong; Zhang, Yi; Yuan, Jie; Fu, Bao; Xie, Peng; Song, Ganjun; Li, Ying; Yu, Tian

2018-01-01

Objective: Herpes zoster (HZ) can develop into postherpetic neuralgia (PHN), which is a chronic neuropathic pain (NP). Whether the chronification from HZ to PHN induced brain functional or structural change is unknown and no study compared the changes of the same brains of patients who transited from HZ to PHN. We minimized individual differences and observed whether the chronification of HZ to PHN induces functional and pain duration dependent grey matter volume (GMV) change in HZ-PHN patients. Methods: To minimize individual differences induced error, we enrolled 12 patients with a transition from HZ to PHN. The functional and structural changes of their brains between the two states were identified with resting-state functional MRI (rs-fMRI) technique (i.e., the regional homogeneity (ReHo) and fractional aptitude of low-frequency fluctuation (fALFF) method) and the voxel based morphometry (VBM) technology respectively. The correlations between MRI parameters (i.e., ΔReHo, ΔfALFF and ΔVBM) and Δpain duration were analyzed too. Results: Compared with HZ brains, PHN brains exhibited abnormal ReHo, fALFF and VBM values in pain matrix (the frontal lobe, parietal lobe, thalamus, limbic lobe and cerebellum) as well as the occipital lobe and temporal lobe. Nevertheless, the activity of vast area of cerebellum and frontal lobe significantly increased while that of occipital lobe and limbic lobe showed apparent decrease when HZ developed to PHN. In addition, PHN brain showed decreased GMV in the frontal lobe, the parietal lobe and the occipital lobe but increased in the cerebellum and the temporal lobe. Correlation analyses showed that some of the ReHo, fALFF and VBM differential areas (such as the cerebellum posterior lobe, the thalamus extra-nuclear and the middle temporal gyrus) correlated well with Δpain duration. Conclusions: HZ chronification induced functional and structural change in cerebellum, occipital lobe, temporal lobe, parietal lobe and limbic lobe. These changes may be correlated with HZ-PHN chronification. In addition, these changes could be reasons of refractory chronic pain of PHN. PMID:29423004

Abnormal cholesterol is associated with prefrontal white matter abnormalities among obese adults, a diffusion tensor imaging study

PubMed Central

Cohen, Jessica I.; Cazettes, Fanny; Convit, Antonio

2011-01-01

The brain is the most cholesterol-rich organ in the body. Although most of the cholesterol in the brain is produced endogenously, some studies suggest that systemic cholesterol may be able to enter the brain. We investigated whether abnormal cholesterol profiles correlated with diffusion-tensor-imaging-based estimates of white matter microstructural integrity of lean and overweight/obese (o/o) adults. Twenty-two lean and 39 obese adults underwent magnetic resonance imaging, kept a 3-day food diary, and had a standardized assessment of fasting blood lipids. The lean group ate less cholesterol rich food than o/o although both groups ate equivalent servings of food per day. Voxelwise correlational analyses controlling for age, diabetes, and white matter hyperintensities, resulted in two significant clusters of negative associations between abnormal cholesterol profile and fractional anisotropy, located in the left and right prefrontal lobes. When the groups were split, the lean subjects showed no associations, whereas the o/o group expanded the association to three significant clusters, still in the frontal lobes. These findings suggest that cholesterol profile abnormalities may explain some of the reductions in white matter microstructural integrity that are reported in obesity. PMID:22163070

Memory Functions following Surgery for Temporal Lobe Epilepsy in Children

ERIC Educational Resources Information Center

Jambaque, Isabelle; Dellatolas, Georges; Fohlen, Martine; Bulteau, Christine; Watier, Laurence; Dorfmuller, Georg; Chiron, Catherine; Delalande, Olivier

2007-01-01

Surgical treatment appears to improve the cognitive prognosis in children undergoing surgery for temporal lobe epilepsy (TLE). The beneficial effects of surgery on memory functions, particularly on material-specific memory, are more difficult to assess because of potentially interacting factors such as age range, intellectual level,…

Content-Specific Source Encoding in the Human Medial Temporal Lobe

ERIC Educational Resources Information Center

Awipi, T.; Davachi, L.

2008-01-01

Although the medial temporal lobe (MTL) is known to be essential for episodic encoding, the contributions of individual MTL subregions remain unclear. Data from recognition memory studies have provided evidence that the hippocampus supports relational encoding important for later episodic recollection, whereas the perirhinal cortex has been linked…

Microencephaloceles: another dual pathology of intractable temporal lobe epilepsy in childhood.

PubMed

Aquilina, Kristian; Clarke, Dave F; Wheless, James W; Boop, Frederick A

2010-04-01

Temporal lobe encephaloceles can be associated with temporal lobe epilepsy. The authors report on the case of an adolescent with multiple microencephaloceles, in the anterolateral middle fossa floor, identified at surgery (temporal lobectomy) for intractable partial-onset seizures of temporal origin. Magnetic resonance imaging revealed only hippocampal atrophy. Subdural electrodes demonstrated ictal activity arising primarily from the anterior and lateral temporal lobe, close to the microencephaloceles, spreading to the anterior and posterior mesial structures. Pathological examination revealed diffuse temporal gliosis involving the hippocampus, together with microdysgenesis of the amygdala. The literature on epilepsy secondary to encephaloceles is reviewed and the contribution of the microencephaloceles to the seizure disorder in this patient is discussed.

Submarine fans: Characteristics, models, classification, and reservoir potential

NASA Astrophysics Data System (ADS)

Shanmugam, G.; Moiola, R. J.

1988-02-01

Submarine-fan sequences are important hydrocarbon reservoirs throughout the world. Submarine-fan sequences may be interpreted from bed-thickness trends, turbidite facies associations, log motifs, and seismic-reflection profiles. Turbidites occurring predominantly in channels and lobes (or sheet sands) constitute the major portion of submarine-fan sequences. Thinning- and thickening-upward trends are suggestive of channel and lobe deposition, respectively. Mounded seismic reflections are commonly indicative of lower-fan depositional lobes. Fan models are discussed in terms of modern and ancient fans, attached and detached lobes, highly efficient and poorly efficient systems, and transverse and longitudinal fans. In general, depositional lobes are considered to be attached to feeder channels. Submarine fans can be classified into four types based on their tectonic settings: (1) immature passive-margin fans (North Sea type); (2) mature passive-margin fans (Atlantic type); (3) active-margin fans (Pacific type); and (4) mixed-setting fans. Immature passive-margin fans (e.g., Balder, North Sea), and active-margin fans (e.g., Navy, Pacific Ocean) are usually small, sand-rich, and possess well developed lobes. Mature passive-margin fans (e.g., Amazon, Atlantic Ocean) are large, mud-rich, and do not develop typical lobes. However, sheet sands are common in the lower-fan regions of mature passive-margin fans. Mixed-setting fans display characteristics of either Atlantic type (e.g., Bengal, Bay of Bengal), or Pacific type (Orinoco, Caribbean), or both. Conventional channel-lobe models may not be applicable to fans associated with mature passive margins. Submarine fans develop primarily during periods of low sea level on both active- and passive-margin settings. Consequently, hydrocarbon-bearing fan sequences are associated generally with global lowstands of sea level. Channel-fill sandstones in most tectonic settings are potential reservoirs. Lobes exhibit the most favorable reservoir quality in terms of sand content, lateral continuity, and porosity development. Lower-fan sheet sands may also make good reservoirs. Quartz-rich sandstones of mature passive-margin fans are most likely to preserve depositional porosity, whereas lithic sandstones of active-margin fans may not.

Profiles of Reactivity in Cocaine-Exposed Children

ERIC Educational Resources Information Center

Schuetze, Pamela; Molnar, Danielle S.; Eiden, Rina D.

2012-01-01

This study explored the possibility that specific, theoretically consistent profiles of reactivity could be identified in a sample of cocaine-exposed infants and whether these profiles were associated with a range of infant and/or maternal characteristics. Cluster analysis was used to identify distinct groups of infants based on physiological,…

Memory in autistic spectrum disorder.

PubMed

Boucher, Jill; Mayes, Andrew; Bigham, Sally

2012-05-01

Behavioral evidence concerning memory in forms of high-functioning autism (HFA) and in moderately low-functioning autism (M-LFA) is reviewed and compared. Findings on M-LFA are sparse. However, it is provisionally concluded that memory profiles in HFA and M-LFA (relative to ability-matched controls) are similar but that declarative memory impairments are more extensive in M-LFA than in HFA. Specifically, both groups have diminished memory for emotion- or person-related stimuli. Regarding memory for nonsocial stimuli, both groups probably have mental-age-appropriate nondeclarative memory, and within declarative memory, both groups have mental-age-appropriate immediate free recall of within-span or supraspan lists of unrelated items, as well as cued recall and paired associate learning. By contrast, recognition is largely unimpaired in HFA but moderately impaired in M-LFA, and free recall of meaningful or structured stimuli is moderately impaired in HFA but more severely impaired in M-LFA. Theoretical explanations of data on declarative memory in HFA identify problems in the integrative processing, or the consolidation and storage, of complex stimuli or a specific problem of recollection. Proposed neural substrates include the following: disconnectivity of primary sensory and association areas; dysfunctions of medial prefrontal cortex, hippocampus, or posterior parietal lobe; or combinations of these associated with neural disconnectivity. Hypothetically, perirhinal dysfunction might explain the more extensive declarative memory impairments in M-LFA. Foreseeable consequences of uneven memory abilities in HFA and M-LFA are outlined, including possible effects on language and learning in M-LFA. Finally, priorities for future research are identified, highlighting the urgent need for research on memory in lower functioning individuals. 2012 APA, all rights reserved

Dynamical control of the emission of a square microlaser via symmetry classes

NASA Astrophysics Data System (ADS)

Bittner, S.; Loirette-Pelous, A.; Lafargue, C.; Gozhyk, I.; Ulysse, C.; Dietz, B.; Zyss, J.; Lebental, M.

2018-04-01

A major objective in photonics is to tailor the emission properties of microcavities which is usually achieved with specific cavity shapes. Yet the dynamical change of the emission properties during operation would often be advantageous. The implementation of such a method is still a challenging issue. We present an effective procedure for the dynamical control of the emission lobes which relies on the selection of a specific coherent superposition of degenerate modes belonging to different symmetry classes. It is generally applicable to systems exhibiting pairs of degenerate modes. We explored it experimentally and analytically with organic square microlasers, which emit narrow lobes parallel to their sidewalls. By means of the pump polarization, emission lobes are switched on and off selectively with an extinction ratio better than 1 /50 .

Deformation of the Batestown till of the Lake Michigan lobe, Laurentide ice sheet

USGS Publications Warehouse

Thomason, J.F.; Iverson, N.R.

2009-01-01

Deep, pervasive shear deformation of the bed to high strains (>100) may have been primarily responsible for flow and sediment transport of the Lake Michigan lobe of the Laurentide ice sheet. To test this hypothesis, we sampled at 0.2 m increments a basal till from one advance of the lobe (Batestown till) along vertical profiles and measured fabrics due to both anisotropy of magnetic susceptibility and sand-grain preferred orientation. Unlike past fabric studies, interpretations were guided by results of laboratory experiments in which this till was deformed in simple shear to high strains. Fabric strengths indicate that more than half of the till sampled has a <5% probability of having been sheared to moderate strains (7-30). Secular changes in fabric azimuth over the thickness of the till, probably due to changing ice-flow direction as the lobe receded, indicate that the bed accreted with time and that the depth of deformation of the bed did not exceed a few decimeters. Orientations of principal magnetic susceptibilities show that the state of strain was commonly complex, deviating from bed-parallel simple shear. Deformation is inferred to have been focused in shallow, temporally variable patches during till deposition from ice.

Bacterial microflora of normal and telangiectatic livers in cattle.

PubMed

Stotland, E I; Edwards, J F; Roussel, A J; Simpson, R B

2001-07-01

To identify potential bacterial pathogens in normal and telangiectatic livers of mature cattle at slaughter and to identify consumer risk associated with hepatic telangiectasia. 50 normal livers and 50 severely telangiectatic livers. Normal and telangiectatic livers were collected at slaughter for aerobic and anaerobic bacterial culture. Isolates were identified, and patterns of isolation were analyzed. Histologic examination of all livers was performed. Human pathogens isolated from normal and telangiectatic livers included Escherichia coli O157:H7 and group-D streptococci. Most livers in both groups contained bacteria in low numbers; however, more normal livers yielded negative culture results. More group-D streptococci were isolated from the right lobes of telangiectatic livers than from the left lobes, and more gram-negative anaerobic bacteria were isolated from left lobes of telangiectatic livers than from right lobes. All telangiectatic lesions were free of fibrosis, active necrotizing processes, and inflammation. The USDA regulation condemning telangiectatic livers is justified insofar as these livers contain more bacteria than normal livers do; however, normal livers contain similar species of microflora. Development of telangiectasia could not be linked to an infectious process. The finding of E coli O157:H7 in bovine livers suggests that information regarding bacterial content of other offal and muscle may identify sources of this and other potential foodborne pathogens and assist in establishing critical control points for the meat industry.

Parent Prevention Communication Profiles and Adolescent Substance Use: A Latent Profile Analysis and Growth Curve Model

PubMed Central

Choi, Hye Jeong; Miller-Day, Michelle; Shin, YoungJu; Hecht, Michael L.; Pettigrew, Jonathan; Krieger, Janice L.; Lee, JeongKyu; Graham, John W.

2017-01-01

This current study identifies distinct parent prevention communication profiles and examines whether youth with different parental communication profiles have varying substance use trajectories over time. Eleven schools in two rural school districts in the Midwestern United States were selected, and 784 students were surveyed at three time points from the beginning of 7th grade to the end of 8th grade. A series of latent profile analyses were performed to identify discrete profiles/subgroups of substance-specific prevention communication (SSPC). The results revealed a 4-profile model of SSPC: Active-Open, Passive-Open, Active-Silent, and Passive-Silent. A growth curve model revealed different rates of lifetime substance use depending on the youth’s SSPC profile. These findings have implications for parenting interventions and tailoring messages for parents to fit specific SSPC profiles. PMID:29056872

Robust pulmonary lobe segmentation against incomplete fissures

NASA Astrophysics Data System (ADS)

Gu, Suicheng; Zheng, Qingfeng; Siegfried, Jill; Pu, Jiantao

2012-03-01

As important anatomical landmarks of the human lung, accurate lobe segmentation may be useful for characterizing specific lung diseases (e.g., inflammatory, granulomatous, and neoplastic diseases). A number of investigations showed that pulmonary fissures were often incomplete in image depiction, thereby leading to the computerized identification of individual lobes a challenging task. Our purpose is to develop a fully automated algorithm for accurate identification of individual lobes regardless of the integrity of pulmonary fissures. The underlying idea of the developed lobe segmentation scheme is to use piecewise planes to approximate the detected fissures. After a rotation and a global smoothing, a number of small planes were fitted using local fissures points. The local surfaces are finally combined for lobe segmentation using a quadratic B-spline weighting strategy to assure that the segmentation is smooth. The performance of the developed scheme was assessed by comparing with a manually created reference standard on a dataset of 30 lung CT examinations. These examinations covered a number of lung diseases and were selected from a large chronic obstructive pulmonary disease (COPD) dataset. The results indicate that our scheme of lobe segmentation is efficient and accurate against incomplete fissures.

A comparative study of Ligophorus uruguayense and L. saladensis (Monogenea: Ancyrocephalidae) from Mugil liza (Teleostei: Mugilidae) in southern Brazil.

PubMed

Marchiori, Natalia C; Pariselle, Antoine; Pereira, Joaber; Agnese, Jean-Francois; Durand, Jean-Dominique; Vanhove, Maarten P M

2015-01-01

Representatives of Ligophorus Euzet et Suriano, 1977 were found on the gills of Mugil liza Valenciennes caught in southern Brazil. They were identified as Ligophorus uruguayense Failla Siquier et Ostrowski de Núñez, 2009 and Ligophorus saladensis Marcotegui et Martorelli, 2009, even though specific identification proved to be difficult due to inconsistencies in some diagnostic features reported for these two species. Therefore, a combined morphological and molecular approach was used to critically review the validity of these species, by means of phase contrast and confocal fluorescence microscopical examination of sclerotised hard parts, and assessing the genetic divergence between L. saladensis, L. uruguayense and their congeners using rDNA sequences. The main morphological differences between the two species relate to the shape of the accessory piece of the penis and the median process of the ventral bar. The accessory piece in L. uruguayense is shorter than in L. saladensis, has a cylindrical, convex upper lobe and straight lower lobe (vs with the distal tip of the lower lobe turning away from the upper lobe in the latter species). The ventral bar has a V-shaped anterior median part in L. uruguayense (vs U-shaped in L. saladensis). The two species are suggested to be part of a species complex together with L. mediterraneus Sarabeev, Balbuena et Euzet, 2005. We recommend to generalise such comparative assessment of species of Ligophorus for a reliable picture of the diversity and diversification mechanisms within the genus, and to make full use of its potential as an additional marker for mullet taxonomy and systematics.

The Temporal Lobes Differentiate between the Voices of Famous and Unknown People: An Event-Related fMRI Study on Speaker Recognition

PubMed Central

Bethmann, Anja; Scheich, Henning; Brechmann, André

2012-01-01

It is widely accepted that the perception of human voices is supported by neural structures located along the superior temporal sulci. However, there is an ongoing discussion to what extent the activations found in fMRI studies are evoked by the vocal features themselves or are the result of phonetic processing. To show that the temporal lobes are indeed engaged in voice processing, short utterances spoken by famous and unknown people were presented to healthy young participants whose task it was to identify the familiar speakers. In two event-related fMRI experiments, the temporal lobes were found to differentiate between familiar and unfamiliar voices such that named voices elicited higher BOLD signal intensities than unfamiliar voices. Yet, the temporal cortices did not only discriminate between familiar and unfamiliar voices. Experiment 2, which required overtly spoken responses and allowed to distinguish between four familiarity grades, revealed that there was a fine-grained differentiation between all of these familiarity levels with higher familiarity being associated with larger BOLD signal amplitudes. Finally, we observed a gradual response change such that the BOLD signal differences between unfamiliar and highly familiar voices increased with the distance of an area from the transverse temporal gyri, especially towards the anterior temporal cortex and the middle temporal gyri. Therefore, the results suggest that (the anterior and non-superior portions of) the temporal lobes participate in voice-specific processing independent from phonetic components also involved in spoken speech material. PMID:23112826

Abstract Representations of Object-Directed Action in the Left Inferior Parietal Lobule.

PubMed

Chen, Quanjing; Garcea, Frank E; Jacobs, Robert A; Mahon, Bradford Z

2018-06-01

Prior neuroimaging and neuropsychological research indicates that the left inferior parietal lobule in the human brain is a critical substrate for representing object manipulation knowledge. In the present functional MRI study we used multivoxel pattern analyses to test whether action similarity among objects can be decoded in the inferior parietal lobule independent of the task applied to objects (identification or pantomime) and stimulus format in which stimuli are presented (pictures or printed words). Participants pantomimed the use of objects, cued by printed words, or identified pictures of objects. Classifiers were trained and tested across task (e.g., training data: pantomime; testing data: identification), stimulus format (e.g., training data: word format; testing format: picture) and specific objects (e.g., training data: scissors vs. corkscrew; testing data: pliers vs. screwdriver). The only brain region in which action relations among objects could be decoded across task, stimulus format and objects was the inferior parietal lobule. By contrast, medial aspects of the ventral surface of the left temporal lobe represented object function, albeit not at the same level of abstractness as actions in the inferior parietal lobule. These results suggest compulsory access to abstract action information in the inferior parietal lobe even when simply identifying objects.

Dissociable Contributions within the Medial Temporal Lobe to Encoding of Object-Location Associations

ERIC Educational Resources Information Center

Sommer, Tobias; Rose, Michael; Glascher, Jan; Wolbers, Thomas; Buchel, Christian

2005-01-01

The crucial role of the medial temporal lobe (MTL) in episodic memory is well established. Although there is little doubt that its anatomical subregions--the hippocampus, peri-, entorhinal and parahippocampal cortex (PHC)--contribute differentially to mnemonic processes, their specific functions in episodic memory are under debate. Data from…

Is déjà vu a symptom of temporal lobe epilepsy?

PubMed

Neppe, V M

1981-12-05

The definition and conceptualization of the déjà vu phenomenon are interpreted in various ways. The common occurrence of déjà vu is the general population stresses the need for the development of specific qualitative features which will be valuable in the diagnosis of temporal lobe epilepsy.

Charting the Maturation of the Frontal Lobe: An Electrophysiological Strategy

ERIC Educational Resources Information Center

Segalowitz, S. J.; Davies, Patricia L.

2004-01-01

Tracking the functional development of specific regions of the prefrontal cortex in children using event-related potentials (ERPs) is challenging for both technical and conceptual reasons. In this paper we outline our strategy for studying frontal lobe development and present preliminary results from children aged 7-17 years and young adults using…

Violence and Personality in Forensic Patients: Is There a Forensic Patient-Specific Personality Profile?

ERIC Educational Resources Information Center

Stupperich, Alexandra; Ihm, Helga; Strack, Micha

2009-01-01

Concerning the discussion about the connection of personality traits, personality disorders, and mental illness, this study focused on the personality profiles of male forensic patients, prison inmates, and young men without criminal reports. The main topic centered on group-specific personality profiles and identifying personality facets…

Differences in visual vs. verbal memory impairments as a result of focal temporal lobe damage in patients with traumatic brain injury.

PubMed

Ariza, Mar; Pueyo, Roser; Junqué, Carme; Mataró, María; Poca, María Antonia; Mena, Maria Pau; Sahuquillo, Juan

2006-09-01

The aim of the present study was to determine whether the type of lesion in a sample of moderate and severe traumatic brain injury (TBI) was related to material-specific memory impairment. Fifty-nine patients with TBI were classified into three groups according to whether the site of the lesion was right temporal, left temporal or diffuse. Six-months post-injury, visual (Warrington's Facial Recognition Memory Test and Rey's Complex Figure Test) and verbal (Rey's Auditory Verbal Learning Test) memories were assessed. Visual memory deficits assessed by facial memory were associated with right temporal lobe lesion, whereas verbal memory performance assessed with a list of words was related to left temporal lobe lesion. The group with diffuse injury showed both verbal and visual memory impairment. These results suggest a material-specific memory impairment in moderate and severe TBI after focal temporal lesions and a non-specific memory impairment after diffuse damage.

Exploring the roles of spectral detail and intonation contour in speech intelligibility: an FMRI study.

PubMed

Kyong, Jeong S; Scott, Sophie K; Rosen, Stuart; Howe, Timothy B; Agnew, Zarinah K; McGettigan, Carolyn

2014-08-01

The melodic contour of speech forms an important perceptual aspect of tonal and nontonal languages and an important limiting factor on the intelligibility of speech heard through a cochlear implant. Previous work exploring the neural correlates of speech comprehension identified a left-dominant pathway in the temporal lobes supporting the extraction of an intelligible linguistic message, whereas the right anterior temporal lobe showed an overall preference for signals clearly conveying dynamic pitch information [Johnsrude, I. S., Penhune, V. B., & Zatorre, R. J. Functional specificity in the right human auditory cortex for perceiving pitch direction. Brain, 123, 155-163, 2000; Scott, S. K., Blank, C. C., Rosen, S., & Wise, R. J. Identification of a pathway for intelligible speech in the left temporal lobe. Brain, 123, 2400-2406, 2000]. The current study combined modulations of overall intelligibility (through vocoding and spectral inversion) with a manipulation of pitch contour (normal vs. falling) to investigate the processing of spoken sentences in functional MRI. Our overall findings replicate and extend those of Scott et al. [Scott, S. K., Blank, C. C., Rosen, S., & Wise, R. J. Identification of a pathway for intelligible speech in the left temporal lobe. Brain, 123, 2400-2406, 2000], where greater sentence intelligibility was predominately associated with increased activity in the left STS, and the greatest response to normal sentence melody was found in right superior temporal gyrus. These data suggest a spatial distinction between brain areas associated with intelligibility and those involved in the processing of dynamic pitch information in speech. By including a set of complexity-matched unintelligible conditions created by spectral inversion, this is additionally the first study reporting a fully factorial exploration of spectrotemporal complexity and spectral inversion as they relate to the neural processing of speech intelligibility. Perhaps surprisingly, there was little evidence for an interaction between the two factors-we discuss the implications for the processing of sound and speech in the dorsolateral temporal lobes.

Persistent post-traumatic headache vs. migraine: an MRI study demonstrating differences in brain structure.

PubMed

Schwedt, Todd J; Chong, Catherine D; Peplinski, Jacob; Ross, Katherine; Berisha, Visar

2017-08-22

The majority of individuals with post-traumatic headache have symptoms that are indistinguishable from migraine. The overlap in symptoms amongst these individuals raises the question as to whether post-traumatic headache has a unique pathophysiology or if head trauma triggers migraine. The objective of this study was to compare brain structure in individuals with persistent post-traumatic headache (i.e. headache lasting at least 3 months following a traumatic brain injury) attributed to mild traumatic brain injury to that of individuals with migraine. Twenty-eight individuals with persistent post-traumatic headache attributed to mild traumatic brain injury and 28 individuals with migraine underwent brain magnetic resonance imaging on a 3 T scanner. Regional volumes, cortical thickness, surface area and curvature measurements were calculated from T1-weighted sequences and compared between subject groups using ANCOVA. MRI data from 28 healthy control subjects were used to interpret the differences in brain structure between migraine and persistent post-traumatic headache. Differences in regional volumes, cortical thickness, surface area and brain curvature were identified when comparing the group of individuals with persistent post-traumatic headache to the group with migraine. Structure was different between groups for regions within the right lateral orbitofrontal lobe, left caudal middle frontal lobe, left superior frontal lobe, left precuneus and right supramarginal gyrus (p < .05). Considering these regions only, there were differences between individuals with persistent post-traumatic headache and healthy controls within the right lateral orbitofrontal lobe, right supramarginal gyrus, and left superior frontal lobe and no differences when comparing the migraine cohort to healthy controls. In conclusion, persistent post-traumatic headache and migraine are associated with differences in brain structure, perhaps suggesting differences in their underlying pathophysiology. Additional studies are needed to further delineate similarities and differences in brain structure and function that are associated with post-traumatic headache and migraine and to determine their specificity for each of the headache types.

Identification of cancer-specific motifs in mimotope profiles of serum antibody repertoire.

PubMed

Gerasimov, Ekaterina; Zelikovsky, Alex; Măndoiu, Ion; Ionov, Yurij

2017-06-07

For fighting cancer, earlier detection is crucial. Circulating auto-antibodies produced by the patient's own immune system after exposure to cancer proteins are promising bio-markers for the early detection of cancer. Since an antibody recognizes not the whole antigen but 4-7 critical amino acids within the antigenic determinant (epitope), the whole proteome can be represented by a random peptide phage display library. This opens the possibility to develop an early cancer detection test based on a set of peptide sequences identified by comparing cancer patients' and healthy donors' global peptide profiles of antibody specificities. Due to the enormously large number of peptide sequences contained in global peptide profiles generated by next generation sequencing, the large number of cancer and control sera is required to identify cancer-specific peptides with high degree of statistical significance. To decrease the number of peptides in profiles generated by nextgen sequencing without losing cancer-specific sequences we used for generation of profiles the phage library enriched by panning on the pool of cancer sera. To further decrease the complexity of profiles we used computational methods for transforming a list of peptides constituting the mimotope profiles to the list motifs formed by similar peptide sequences. We have shown that the amino-acid order is meaningful in mimotope motifs since they contain significantly more peptides than motifs among peptides where amino-acids are randomly permuted. Also the single sample motifs significantly differ from motifs in peptides drawn from multiple samples. Finally, multiple cancer-specific motifs have been identified.

Contributions of the Medial Temporal Lobe to Declarative Memory Retrieval: Manipulating the Amount of Contextual Retrieval

ERIC Educational Resources Information Center

Tendolkar, Indira; Arnold, Jennifer; Petersson, Karl Magnus; Weis, Susanne; Brockhaus-Dumke, Anke; van Eijndhoven, Philip; Buitelaar, Jan; Fernandez, Guillen

2008-01-01

We investigated how the hippocampus and its adjacent mediotemporal structures contribute to contextual and noncontextual declarative memory retrieval by manipulating the amount of contextual information across two levels of the same contextual dimension in a source memory task. A first analysis identified medial temporal lobe (MTL) substructures…

Morphology and morphometry of the caudate lobe of the liver in two populations.

PubMed

Sagoo, Mandeep Gill; Aland, R Claire; Gosden, Edward

2018-01-01

The caudate lobe of the liver has portal blood supply and hepatic vein drainage independent of the remainder of the liver and may be differentially affected in liver pathologies. Ultrasonographic measurement of the caudate lobe can be used to generate hepatic indices that may indicate cirrhosis. This study investigated the relationship of metrics of the caudate lobe and other morphological features of human livers from a northwest Indian Punjabi population (n = 50) and a UK Caucasian population (n = 25), which may affect the calculation of hepatic indices. The width of the right lobe of the liver was significantly smaller, while the anteroposterior diameter of the caudate lobe and both Harbin's Index and the Hess Index scores were significantly larger in NWI livers than in UKC livers. The Hess Index score, in particular, is much larger in the NWI population (265 %, p < 0.005). Two caudate lobe features were significantly different between the two populations-the shape of the caudate lobe and the development of the caudate process. This study shows significant population differences exist in several metrics and morphological features of the liver. These differences may affect the calculation of hepatic indices, resulting in a greater percentage of false positives of cirrhosis in the NWI population. Population-specific data are required to correctly determine normal ranges.

Thalamic functional connectivity predicts seizure laterality in individual TLE patients: application of a biomarker development strategy.

PubMed

Barron, Daniel S; Fox, Peter T; Pardoe, Heath; Lancaster, Jack; Price, Larry R; Blackmon, Karen; Berry, Kristen; Cavazos, Jose E; Kuzniecky, Ruben; Devinsky, Orrin; Thesen, Thomas

2015-01-01

Noninvasive markers of brain function could yield biomarkers in many neurological disorders. Disease models constrained by coordinate-based meta-analysis are likely to increase this yield. Here, we evaluate a thalamic model of temporal lobe epilepsy that we proposed in a coordinate-based meta-analysis and extended in a diffusion tractography study of an independent patient population. Specifically, we evaluated whether thalamic functional connectivity (resting-state fMRI-BOLD) with temporal lobe areas can predict seizure onset laterality, as established with intracranial EEG. Twenty-four lesional and non-lesional temporal lobe epilepsy patients were studied. No significant differences in functional connection strength in patient and control groups were observed with Mann-Whitney Tests (corrected for multiple comparisons). Notwithstanding the lack of group differences, individual patient difference scores (from control mean connection strength) successfully predicted seizure onset zone as shown in ROC curves: discriminant analysis (two-dimensional) predicted seizure onset zone with 85% sensitivity and 91% specificity; logistic regression (four-dimensional) achieved 86% sensitivity and 100% specificity. The strongest markers in both analyses were left thalamo-hippocampal and right thalamo-entorhinal cortex functional connection strength. Thus, this study shows that thalamic functional connections are sensitive and specific markers of seizure onset laterality in individual temporal lobe epilepsy patients. This study also advances an overall strategy for the programmatic development of neuroimaging biomarkers in clinical and genetic populations: a disease model informed by coordinate-based meta-analysis was used to anatomically constrain individual patient analyses.

Bronchovascular anatomy of the upper lobes: evaluation with thin-section CT.

PubMed

Lee, K S; Bae, W K; Lee, B H; Kim, I Y; Choi, E W; Lee, B H

1991-12-01

The anatomy of the bronchovascular trees of the upper lobes was evaluated with thin-section computed tomography (CT) in 50 patients. In all patients, the subsegmental bronchi could be seen, except the right B2b, left B1 + 2c, and left B3c. Regular anatomic relationships were seen between the right A3b and B3b (A3b was seen along the medial aspect of B3b in 45 patients [90%]), right A2a and B2a (A2a was seen along the posteromedial aspect of B2a in 45 patients [90%]), and left A1 + 2c and B1 + 2c (A1 + 2c was seen along the posterior aspect of B1 + 2c in 41 patients [82%]). Four patterns of bronchial branching were seen in the left upper lobe. The lateral branch of the posterior segmental vein of the upper lobes was an anatomic landmark dividing the anterior and posterior segments of the upper lobes. Three kinds of venous drainage patterns were identified in both the right and left upper lobes.

Preserving lung after traumatic transection of left lower lobe bronchus from bullet injury.

PubMed

Hanif, Muhammad Shoaib; Mishwani, A H; Oparka, J; Buchan, K

2015-06-01

A 22-year-old soldier was shot in the left chest by a bullet from close range. He was found to have a left haemothorax and remained shocked despite aggressive resuscitation. Due to difficult terrain and night time movement restrictions, there were limitations to the transfer of patient. So he was attended at a peripheral hospital. At emergency thoracotomy, three segmental arteries to left upper lobe were ligated and haemostasis was secured. The level of transection of left lower lobe bronchus was identified to be below the origin of the apical segmental bronchus. The lower lobe bronchus was successfully re-attached and followed up with a daily bronchoscopic clearance of distal airway. The patient made a full recovery. Anastomosis of left lower lobe bronchus after traumatic transection is a viable option for preserving an amputated lobe, in trauma settings, provided haemostatic control has been adequately achieved. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

MRI Neuroanatomy in Young Girls with Autism: A Preliminary Study

ERIC Educational Resources Information Center

Bloss, Cinnamon S.; Courchesne, Eric

2007-01-01

Objective: To test the hypothesis that young girls and boys with autism exhibit different profiles of neuroanatomical abnormality relative to each other and relative to typically developing children. Method: Structural magnetic resonance imaging was used to measure gray and white matter volumes (whole cerebrum, cerebral lobes, and cerebellum) and…

Cell type-specific localization of Ephs pairing with ephrin-B2 in the rat postnatal pituitary gland.

PubMed

Yoshida, Saishu; Kato, Takako; Kanno, Naoko; Nishimura, Naoto; Nishihara, Hiroto; Horiguchi, Kotaro; Kato, Yukio

2017-10-01

Sox2-expressing stem/progenitor cells in the anterior lobe of the pituitary gland form two types of micro-environments (niches): the marginal cell layer and dense cell clusters in the parenchyma. In relation to the mechanism of regulation of niches, juxtacrine signaling via ephrin and its receptor Eph is known to play important roles in various niches. The ephrin and Eph families are divided into two subclasses to create ephrin/Eph signaling in co-operation with confined partners. Recently, we reported that ephrin-B2 localizes specifically to both pituitary niches. However, the Ephs interacting with ephrin-B2 in these pituitary niches have not yet been identified. Therefore, the present study aims to identify the Ephs interacting with ephrin-B2 and the cells that produce them in the rat pituitary gland. In situ hybridization and immunohistochemistry demonstrated cell type-specific localization of candidate interacting partners for ephrin-B2, including EphA4 in cells located in the posterior lobe, EphB1 in gonadotropes, EphB2 in corticotropes, EphB3 in stem/progenitor cells and EphB4 in endothelial cells in the adult pituitary gland. In particular, double-immunohistochemistry showed cis-interactions between EphB3 and ephrin-B2 in the apical cell membranes of stem/progenitor cell niches throughout life and trans-interactions between EphB2 produced by corticotropes and ephrin-B2 located in the basolateral cell membranes of stem/progenitor cells in the early postnatal pituitary gland. These data indicate that ephrin-B2 plays a role in pituitary stem/progenitor cell niches by selective interaction with EphB3 in cis and EphB2 in trans.

Deformation of the Calabrian accretionary wedge and relative kinematics of the Calabrian and Peloritan backstops: Insights from multibeam bathymetry, high-resolution reflection and wide-angle seismics and analog modeling

NASA Astrophysics Data System (ADS)

Dellong, David; Gutscher, Marc-Andre; Klingelhoefer, Frauke; Graindorge, David; Kopp, Heidrun; Moretti, Milena; Marsset, Bruno; Mercier de Lepinay, Bernard; Dominguez, Stephane; Malavieille, Jacques

2016-04-01

Recently acquired swath bathymetric data in the Ionian Sea document in unprecedented detail the morphostructure and dynamics of the Calabrian accretionary wedge. A boundary zone between the eastern and western lobes of the accretionary wedge is examined here. Relative displacement between the Calabrian and Peloritan backstops is expected to cause dextral strike-slip deformation between the lobes. A wide-angle seismic profile was acquired in Oct. 2014 with the R/V Meteor (DIONYSUS survey) recorded by 25 Ocean-bottom seismometers (Geomar and Ifremer instruments) and 3 land-stations (INGV stations). Inversion and forward modeling of these seismic data reveal a 5-10 km deep asymmetric rift zone between the Malta Escarpment and the SW tip of Calabria. Analog modeling was performed to test if the origin of this rift could be related to the relative kinematics of the Calabrian and Peloritan backstops. Modeling, using two independently moving backstops, produces a zone of dextral transtension and subsidence in the accretionary wedge between two lobes. This corresponds well to the asymmetric rift observed in the southward prolongation of the straits of Messina faults. Paradoxically however, this dextral displacement does not appear to traverse the external Calabrian accretionary wedge, where prominent curved lineaments observed indicate a sinistral sense of motion. One possible explanation is that the dextral kinematic motion is transferred into a region of crisscrossing faults in the internal portion of the Eastern lobe. The bathymetry and high-resolution reflection seismic images indicate ongoing compression at the deformation front of both the western and eastern lobes. Together with the analog modeling results, these observations unambiguously demonstrate that the western lobe remains tectonically active.

Neural correlates of inhibitory control in adult ADHD: Evidence from the Milwaukee longitudinal sample

PubMed Central

Mulligan, Richard C.; Knopik, Valerie S.; Sweet, Lawrence H.; Fischer, Mariellen; Seidenberg, Michael; Rao, Stephen M.

2011-01-01

Only a few studies have investigated the neural substrate of response inhibition in adult ADHD using Stop-Signal and Go/No-Go tasks. Inconsistencies and methodological limitations in the existing literature have resulted in limited conclusions regarding underlying pathophysiology. We examined the neural basis of response inhibition in a group of adults diagnosed with ADHD in childhood and who continue to meet criteria for ADHD while addressing limitations present in earlier studies. Adults with ADHD (n=12) and controls (n=12) were recruited from an ongoing longitudinal study and were matched for age, IQ, and education. Individuals with comorbid conditions were excluded. Functional MRI was used to identify and compare the brain activation patterns during correct trials of a response inhibition task (Go/No-Go). Our results showed that the control group recruited a more extensive network of brain regions than the ADHD group during correct inhibition trials. Adults with ADHD showed reduced brain activation in the right frontal eye field, pre-supplementary motor area, left precentral gyrus, and the inferior parietal lobe bilaterally. During successful inhibition of an inappropriate response, adults with ADHD display reduced activation in fronto-parietal networks previously implicated in working memory, goal-oriented attention, and response selection. This profile of brain activation may be specifically associated with ADHD in adulthood. PMID:21937201

Use of Clinical and Neuroimaging Characteristics to Distinguish Temporal Lobe Herpes Simplex Encephalitis From Its Mimics

PubMed Central

Chow, Felicia C.; Glaser, Carol A.; Sheriff, Heather; Xia, Dongxiang; Messenger, Sharon; Whitley, Richard; Venkatesan, Arun

2015-01-01

Background. We describe the spectrum of etiologies associated with temporal lobe (TL) encephalitis and identify clinical and radiologic features that distinguish herpes simplex encephalitis (HSE) from its mimics. Methods. We reviewed all adult cases of encephalitis with TL abnormalities on magnetic resonance imaging (MRI) from the California Encephalitis Project. We evaluated the association between specific clinical and MRI characteristics and HSE compared with other causes of TL encephalitis and used multivariate logistic modeling to identify radiologic predictors of HSE. Results. Of 251 cases of TL encephalitis, 43% had an infectious etiology compared with 16% with a noninfectious etiology. Of infectious etiologies, herpes simplex virus was the most commonly identified agent (n = 60), followed by tuberculosis (n = 8) and varicella zoster virus (n = 7). Of noninfectious etiologies, more than half (n = 21) were due to autoimmune disease. Patients with HSE were older (56.8 vs 50.2 years; P = .012), more likely to be white (53% vs 35%; P = .013), more likely to present acutely (88% vs 64%; P = .001) and with a fever (80% vs 49%; P < .001), and less likely to present with a rash (2% vs 15%; P = .010). In a multivariate model, bilateral TL involvement (odds ratio [OR], 0.38; 95% confidence interval [CI], .18–.79; P = .010) and lesions outside the TL, insula, or cingulate (OR, 0.37; 95% CI, .18–.74; P = .005) were associated with lower odds of HSE. Conclusions. In addition to HSE, other infectious and noninfectious etiologies should be considered in the differential diagnosis for TL encephalitis, depending on the presentation. Specific clinical and imaging features may aid in distinguishing HSE from non-HSE causes of TL encephalitis. PMID:25637586

Polarized skylight navigation in insects: model and electrophysiology of e-vector coding by neurons in the central complex.

PubMed

Sakura, Midori; Lambrinos, Dimitrios; Labhart, Thomas

2008-02-01

Many insects exploit skylight polarization for visual compass orientation or course control. As found in crickets, the peripheral visual system (optic lobe) contains three types of polarization-sensitive neurons (POL neurons), which are tuned to different ( approximately 60 degrees diverging) e-vector orientations. Thus each e-vector orientation elicits a specific combination of activities among the POL neurons coding any e-vector orientation by just three neural signals. In this study, we hypothesize that in the presumed orientation center of the brain (central complex) e-vector orientation is population-coded by a set of "compass neurons." Using computer modeling, we present a neural network model transforming the signal triplet provided by the POL neurons to compass neuron activities coding e-vector orientation by a population code. Using intracellular electrophysiology and cell marking, we present evidence that neurons with the response profile of the presumed compass neurons do indeed exist in the insect brain: each of these compass neuron-like (CNL) cells is activated by a specific e-vector orientation only and otherwise remains silent. Morphologically, CNL cells are tangential neurons extending from the lateral accessory lobe to the lower division of the central body. Surpassing the modeled compass neurons in performance, CNL cells are insensitive to the degree of polarization of the stimulus between 99% and at least down to 18% polarization and thus largely disregard variations of skylight polarization due to changing solar elevations or atmospheric conditions. This suggests that the polarization vision system includes a gain control circuit keeping the output activity at a constant level.

Implantation of healthy matrix-embedded endothelial cells rescues dysfunctional endothelium and ischemic tissue in liver engraftment

PubMed Central

Melgar-Lesmes, Pedro; Balcells, Mercedes; Edelman, Elazer R.

2017-01-01

Objective Liver transplantation is limited by ischemic injury which promotes endothelial cell and hepatocyte dysfunction and eventually organ failure. We sought to understand how endothelial state determines liver recover after hepatectomy and engraftment. Design Matrix-embedded endothelial cells (MEECs) with retained healthy phenotype or control acellular matrices were implanted in direct contact with the remaining median lobe of donor mice undergoing partial hepatectomy (70%), or in the interface between the remaining median lobe and an autograft or isograft from the left lobe in hepatectomized recipient mice. Hepatic vascular architecture, DNA fragmentation and apoptosis in the median lobe and grafts, serum markers of liver damage and phenotype of macrophage and lymphocyte subsets in the liver after engraftment were analyzed 7 days post-op. Results Healthy MEECs create a functional vascular splice in donor and recipient liver after 70% hepatectomy in mouse protecting these livers from ischemic injury, hepatic congestion and inflammation. Macrophages recruited adjacent to the vascular nodes into the implants switched to an anti-inflammatory and regenerative profile M2. MEECs improved liver function and the rate of liver regeneration and prevented apoptosis in donor liver lobes, autologous grafts, and allogeneic engraftment. Conclusions Implants with healthy endothelial cells rescue liver donor and recipient endothelium and parenchyma from ischemic injury after major hepatectomy and engraftment. This study highlights endothelial-hepatocyte crosstalk in hepatic repair and provides a promising new approach to improve regenerative medicine outcomes and liver transplantation. PMID:26851165

Subcomponents and Connectivity of the Inferior Fronto-Occipital Fasciculus Revealed by Diffusion Spectrum Imaging Fiber Tracking

PubMed Central

Wu, Yupeng; Sun, Dandan; Wang, Yong; Wang, Yibao

2016-01-01

The definitive structure and functional role of the inferior fronto-occipital fasciculus (IFOF) are still controversial. In this study, we aimed to investigate the connectivity, asymmetry, and segmentation patterns of this bundle. High angular diffusion spectrum imaging (DSI) analysis was performed on 10 healthy adults and a 90-subject DSI template (NTU-90 Atlas). In addition, a new tractography approach based on the anatomic subregions and two regions of interest (ROI) was evaluated for the fiber reconstructions. More widespread anterior-posterior connections than previous “standard” definition of the IFOF were found. This distinct pathway demonstrated a greater inter-subjects connective variability with a maximum of 40% overlap in its central part. The statistical results revealed no asymmetry between the left and right hemispheres and no significant differences existed in distributions of the IFOF according to sex. In addition, five subcomponents within the IFOF were identified according to the frontal areas of originations. As the subcomponents passed through the anterior floor of the external capsule, the fibers radiated to the posterior terminations. The most common connection patterns of the subcomponents were as follows: IFOF-I, from frontal polar cortex to occipital pole, inferior occipital lobe, middle occipital lobe, superior occipital lobe, and pericalcarine; IFOF-II, from orbito-frontal cortex to occipital pole, inferior occipital lobe, middle occipital lobe, superior occipital lobe, and pericalcarine; IFOF-III, from inferior frontal gyrus to inferior occipital lobe, middle occipital lobe, superior occipital lobe, occipital pole, and pericalcarine; IFOF-IV, from middle frontal gyrus to occipital pole, and inferior occipital lobe; IFOF-V, from superior frontal gyrus to occipital pole, inferior occipital lobe, and middle occipital lobe. Our work demonstrates the feasibility of high resolution diffusion tensor tractography with sufficient sensitivity to elucidate more anatomical details of the IFOF. And we provides a new framework for subdividing the IFOF for better understanding its functional role in the human brain. PMID:27721745

Selective Familiarity Deficits after Left Anterior Temporal-Lobe Removal with Hippocampal Sparing Are Material Specific

ERIC Educational Resources Information Center

Martin, Chris B.; Bowles, Ben; Mirsattari, Seyed M.; Kohler, Stefan

2011-01-01

Research has firmly established a link between recognition memory and the functional integrity of the medial temporal lobes (MTL). Dual-process models of MTL organization maintain that there is a division of labour within the MTL, with the hippocampus (HC) supporting recollective processes and perirhinal cortex (PRc) supporting familiarity…

Cerebellar Directed Optogenetic Intervention Inhibits Spontaneous Hippocampal Seizures in a Mouse Model of Temporal Lobe Epilepsy1 2

PubMed Central

Szabo, Gergely G.; Armstrong, Caren; Oijala, Mikko; Soltesz, Ivan

2014-01-01

Abstract Cover Figure Krook-Magnuson et al. report a bidirectional functional connectivity between the hippocampus and the cerebellum in a mouse model of temporal lobe epilepsy, and demonstrate that cerebellar directed on-demand optogenetic intervention can stop seizures recorded from the hippocampus. Temporal lobe epilepsy is often medically refractory and new targets for intervention are needed. We used a mouse model of temporal lobe epilepsy, on-line seizure detection, and responsive optogenetic intervention to investigate the potential for cerebellar control of spontaneous temporal lobe seizures. Cerebellar targeted intervention inhibited spontaneous temporal lobe seizures during the chronic phase of the disorder. We further report that the direction of modulation as well as the location of intervention within the cerebellum can affect the outcome of intervention. Specifically, on-demand optogenetic excitation or inhibition of parvalbumin-expressing neurons, including Purkinje cells, in the lateral or midline cerebellum results in a decrease in seizure duration. In contrast, a consistent reduction in spontaneous seizure frequency occurs uniquely with on-demand optogenetic excitation of the midline cerebellum, and was not seen with intervention directly targeting the hippocampal formation. These findings demonstrate that the cerebellum is a powerful modulator of temporal lobe epilepsy, and that intervention targeting the cerebellum as a potential therapy for epilepsy should be revisited. PMID:25599088

Ionic residues of human serum transferrin affect binding to the transferrin receptor and iron release.

PubMed

Steere, Ashley N; Miller, Brendan F; Roberts, Samantha E; Byrne, Shaina L; Chasteen, N Dennis; Smith, Valerie C; MacGillivray, Ross T A; Mason, Anne B

2012-01-17

Efficient delivery of iron is critically dependent on the binding of diferric human serum transferrin (hTF) to its specific receptor (TFR) on the surface of actively dividing cells. Internalization of the complex into an endosome precedes iron removal. The return of hTF to the blood to continue the iron delivery cycle relies on the maintenance of the interaction between apohTF and the TFR after exposure to endosomal pH (≤6.0). Identification of the specific residues accounting for the pH-sensitive nanomolar affinity with which hTF binds to TFR throughout the cycle is important to fully understand the iron delivery process. Alanine substitution of 11 charged hTF residues identified by available structures and modeling studies allowed evaluation of the role of each in (1) binding of hTF to the TFR and (2) TFR-mediated iron release. Six hTF mutants (R50A, R352A, D356A, E357A, E367A, and K511A) competed poorly with biotinylated diferric hTF for binding to TFR. In particular, we show that Asp356 in the C-lobe of hTF is essential to the formation of a stable hTF-TFR complex: mutation of Asp356 in the monoferric C-lobe hTF background prevented the formation of the stoichiometric 2:2 (hTF:TFR monomer) complex. Moreover, mutation of three residues (Asp356, Glu367, and Lys511), whether in the diferric or monoferric C-lobe hTF, significantly affected iron release when in complex with the TFR. Thus, mutagenesis of charged hTF residues has allowed identification of a number of residues that are critical to formation of and release of iron from the hTF-TFR complex.

Re-evaluating TTF-1 immunohistochemistry in diffuse gliomas: Expression is clone-dependent and associated with tumor location.

PubMed

Pratt, Drew; Afsar, Nina; Allgauer, Michael; Fetsch, Patricia; Palisoc, Maryknoll; Pittaluga, Stefania; Quezado, Martha

TTF-1 is widely used as a marker in routine surgical pathology in the work-up of malignancy. Aberrant expression of TTF-1 in extrapulmonary and extrathyroidal malignancies is a frequently reported phenomenon. In addition to the recently characterized pituicyte-derived tumors of the sella, immunoreactivity has been reported in diffuse gliomas with the SPT24 clone. Here, we sought to evaluate TTF-1 expression with three commercially available clones in a large series of gliomas. Expression was compared across the newly defined diagnostic entities in the 2016 WHO Classification of CNS Tumors. Using tissue microarrays (TMA), 212 diffuse gliomas (WHO grades II - IV) were systematically evaluated with TTF-1 immunohistochemistry using three clones: SPT24, 8G7G3/1, and SP141, and results correlated with clinicopathologic features. 14 high-grade diffuse gliomas demonstrated nuclear staining with the SP141 and SPT24 clones. Two tumors showed weak positivity with the 8G7G3/1 clone. All tumors were high grade by histology (WHO grades III and IV). 86% (12/14) of TTF-1-positive gliomas involved the frontal lobes at diagnosis. No relationship with IDH R132H, ATRX, p53, H3K27M, or EGFR immunohistochemistry was identified. TTF-1 expression in gliomas was not independently prognostic of overall survival. TTF-1 expression in diffuse gliomas is a rare but potentially misleading occurrence. In our cohort, staining occurred with both the SPT24 and SP141 clones at equal intensity and frequency. Clustering of TTF-1-positive tumors in the frontal lobe(s) suggests lineage-specific expression. Due to clone-specific expression in diffuse gliomas, caution must be exercised in the work-up of intracranial tumors with TTF-1.
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Amyloid and Tau PET Demonstrate Region-Specific Associations in Normal Older People

PubMed Central

Lockhart, Samuel N.; Schöll, Michael; Baker, Suzanne L.; Ayakta, Nagehan; Swinnerton, Kaitlin N.; Bell, Rachel K.; Mellinger, Taylor J.; Shah, Vyoma D.; O’Neil, James P.; Janabi, Mustafa; Jagust, William J.

2017-01-01

β-amyloid (Aβ) and tau pathology become increasingly prevalent with age, however, the spatial relationship between the two pathologies remains unknown. We examined local (same region) and non-local (different region) associations between these 2 aggregated proteins in 46 normal older adults using [18F]AV-1451 (for tau) and [11C]PiB (for Aβ) positron emission tomography (PET) and 1.5T magnetic resonance imaging (MRI) images. While local voxelwise analyses showed associations between PiB and AV-1451 tracer largely in the temporal lobes, k-means clustering revealed that some of these associations were driven by regions with low tracer retention. We followed this up with a whole-brain region-by-region (local and non-local) partial correlational analysis. We calculated each participant’s mean AV-1451 and PiB uptake values within 87 regions of interest (ROI). Pairwise ROI analysis demonstrated many positive PiB—AV-1451 associations. Importantly, strong positive partial correlations (controlling for age, sex, and global gray matter fraction, p < .01) were identified between PiB in multiple regions of association cortex and AV-1451 in temporal cortical ROIs. There were also less frequent and weaker positive associations of regional PiB with frontoparietal AV-1451 uptake. Particularly in temporal lobe ROIs, AV-1451 uptake was strongly predicted by PiB across multiple ROI locations. These data indicate that Aβ and tau pathology show significant local and non-local regional associations among cognitively normal elderly, with increased PiB uptake throughout the cortex correlating with increased temporal lobe AV-1451 uptake. The spatial relationship between Aβ and tau accumulation does not appear to be specific to Aβ location, suggesting a regional vulnerability of temporal brain regions to tau accumulation regardless of where Aβ accumulates. PMID:28232190

Thalamocortical Connections and Executive Function in Pediatric Temporal and Frontal Lobe Epilepsy.

PubMed

Law, N; Smith, M L; Widjaja, E

2018-06-07

Largely accepted in the literature is the role the interconnections between the thalamus and cortex play in generalized epilepsy. However, thalamocortical involvement is less understood in focal epilepsy in terms of the effect of seizures on thalamocortical circuitry in the developing brain and subsequent cognitive outcome. We investigated thalamocortical pathway microstructure in pediatric frontal lobe epilepsy and temporal lobe epilepsy and examined the associations between pathway microstructure and measures of executive function. We examined thalamocortical connections in 24 children with frontal lobe epilepsy, 17 patients with temporal lobe epilepsy, and 25 healthy children using DTI. We investigated several executive function measures in patients and controls, which were distilled into latent executive function components to compare among groups, and the associations between measures of thalamocortical microstructure and executive function. We found no differences in thalamocortical pathway microstructure between the groups, but aspects of executive function (mental flexibility/inhibition/shifting) were impaired in the frontal lobe epilepsy group compared with controls. In patients with frontal lobe epilepsy, younger age at seizure onset and a greater number of antiepileptic drugs were associated with DTI indices indicative of damaged/less developed thalamocortical pathways. In patients with temporal lobe epilepsy, poorer performance on all measures of executive function was associated with DTI indices reflective of damaged/less developed pathways. Our results give insight into vulnerable neural networks in pediatric focal epilepsy and suggest thalamocortical pathway damage as a potential mechanism of executive function impairment in temporal lobe epilepsy but not frontal lobe epilepsy. Identifying structure-function relations can help inform how we measure functional and cognitive/behavioral outcomes in these populations. © 2018 by American Journal of Neuroradiology.

Lung lobe torsion in dogs: 22 cases (1981-1999).

PubMed

Neath, P J; Brockman, D J; King, L G

2000-10-01

To identify breed disposition, postoperative complications, and outcome in dogs with lung lobe torsion. Retrospective study. 22 client-owned dogs. Information on signalment; history; clinical findings; results of clinicopathologic testing, diagnostic imaging, and pleural fluid analysis; surgical treatment; intra- and postoperative complications; histologic findings; and outcome were obtained from medical records. All 22 dogs had pleural effusion; dyspnea was the most common reason for examination. Fifteen dogs were large deep-chested breeds; 5 were toy breeds. Afghan Hounds were overrepresented, compared with the hospital population. One dog was euthanatized without treatment; the remaining dogs underwent exploratory thoracotomy and lung lobectomy. Eleven dogs recovered from surgery without complications, but 3 of these later died of thoracic disease. Four dogs survived to discharge but had clinically important complications within 2 months, including chylothorax, mediastinal mesothelioma, gastric dilatation, and a second lung lobe torsion. Six dogs died or were euthanatized within 2 weeks after surgery because of acute respiratory distress syndrome, pneumonia, septic shock, pneumothorax, or chylothorax. Chylothorax was diagnosed in 8 of the 22 dogs, including 4 Afghan Hounds. Results suggest that lung lobe torsion is rare in dogs and develops most frequently in large deep-chested dogs, particularly Afghan Hounds. Other predisposing causes were not identified, but an association with chylothorax was evident, especially in Afghan Hounds. Prognosis for dogs with lung lobe torsion was fair to guarded.

Computed tomography of partial anomalous pulmonary venous connection in adults.

PubMed

Haramati, Linda B; Moche, Ilana E; Rivera, Vivian T; Patel, Pavni V; Heyneman, Laura; McAdams, H Page; Issenberg, Henry J; White, Charles S

2003-01-01

To systematically describe the imaging features and clinical correlates of a partial anomalous pulmonary venous connection diagnosed on computed tomography (CT) in adults. Twenty-nine adults with a partial anomalous pulmonary venous connection on CT were retrospectively identified. There were 19 women and 10 men, with a mean age of 53 (range: 19-83) years. Four cases were identified by review of 1825 consecutive chest CT reports from July 2000-July 2001, and 25 cases were culled from chest radiology teaching files at 3 institutions. Inclusion criteria were availability of CT images and medical charts. Chest radiographs (25 of 29 cases) were reviewed for mediastinal contour abnormalities, heart size, and pulmonary vascular pattern. Chest CT scans were reviewed for location, size, and drainage site of the anomalous vein; presence or absence of a pulmonary vein in the normal location; cardiac size and configuration; and pulmonary vasculature. Charts were reviewed for evidence of pulmonary and cardiovascular disease, history of congenital heart disease, and results of other cardiac imaging. The prevalence of a partial anomalous pulmonary venous connection was 0.2% (4 of 1825 chest CT reports). Seventy-nine percent (23 of 29 patients) had an anomalous left upper lobe vein connecting to a persistent left vertical vein, only 5% (1 of 23 patients) of whom had a left upper lobe vein in the normal location. Seventeen percent (5 of 29 patients) had an anomalous right upper lobe vein draining into the superior vena cava, 60% (3 of 5 patients) of whom also had a right upper lobe pulmonary vein in the normal location. One patient (3%) had an anomalous right lower lobe vein draining into the suprahepatic inferior vena cava. Chest radiographic findings were abnormal left mediastinal contour in 64% (15 of 25 patients), abnormal right mediastinal contour in 8% (2 of 25 patients), and cardiomegaly in 24% (6 of 25 patients). Computed tomography findings were cardiomegaly in 48% (14 of 29 patients), right atrial enlargement in 31% (9 of 29 patients), right ventricular enlargement in 31% (9 of 29 patients), and pulmonary artery enlargement in 14% (4 of 29 patients). Pulmonary or cardiovascular symptoms were present in 69% (20 of 29 patients), 55% (11 of 20 patients) of whom had specific alternative diagnoses (excluding congestive heart failure and pulmonary hypertension) to explain the symptoms. Only 1 patient (3%) was diagnosed with a secundum atrial septal defect. A partial anomalous pulmonary venous connection was seen in 0.2% of adults on CT. In contrast to previous series focusing on children, the anomalous vein in adults was most commonly from the left upper lobe, in women, and infrequently associated with atrial septal defects.

SOX10-positive cells emerge in the rat pituitary gland during late embryogenesis and start to express S100β.

PubMed

Ueharu, Hiroki; Yoshida, Saishu; Kanno, Naoko; Horiguchi, Kotaro; Nishimura, Naoto; Kato, Takako; Kato, Yukio

2018-04-01

In the pituitary gland, S100β-positive cells localize in the neurohypophysis and adenohypophysis but the lineage of the two groups remains obscure. S100β is often observed in many neural crest-derived cell types. Therefore, in this study, we investigate the origin of pituitary S100β-positive cells by immunohistochemistry for SOX10, a potent neural crest cell marker, using S100β-green fluorescence protein-transgenic rats. On embryonic day 21.5, a SOX10-positive cell population, which was also positive for the stem/progenitor cell marker SOX2, emerged in the pituitary stalk and posterior lobe and subsequently expanded to create a rostral-caudal gradient on postnatal day 3 (P3). Thereafter, SOX10-positive cells appeared in the intermediate lobe by P15, localizing to the boundary facing the posterior lobe, the gap between the lobule structures and the marginal cell layer, a pituitary stem/progenitor cell niche. Subsequently, there was an increase in SOX10/S100β double-positive cells; some of these cells in the gap between the lobule structures showed extended cytoplasm containing F-actin, indicating a feature of migration activity. The proportion of SOX10-positive cells in the postnatal anterior lobe was lower than 0.025% but about half of them co-localized with the pituitary-specific progenitor cell marker PROP1. Collectively, the present study identified that one of the lineages of S100β-positive cells is a SOX10-positive one and that SOX10-positive cells express pituitary stem/progenitor cell marker genes.

The role of SISCOM in preoperative evaluation for patients with epilepsy surgery: A meta-analysis.

PubMed

Chen, Tong; Guo, Liang

2016-10-01

To assess the specific value of subtraction ictal and inter-ictal SPECT co-registered to MRI (SISCOM) in identifying the epileptogenic zone (EZ) and predicting postoperative outcomes in epileptic surgical patients. A meta-analysis of studies published from January 1995 to June 2015 was conducted through a comprehensive literature search, and 11 studies were included. R software was first used to calculate a pooled positive rate, concordant rate and positive predictive value (PPV) for good outcomes. Stata software was then used to explore the relationship between SISCOM localization and surgical outcomes, including a subgroup analysis for extra-temporal lobe epilepsy. The unweighted positive and concordant rates of SISCOM were 85.9% and 65.3%, respectively. In 142 MRI-negative patients, the SISCOM positive rate was 83.8%. The pooled PPV of 178 surgical patients with concordant SISCOM was 56%. In the meta-analysis of 275 surgical patients, the seizure-free odds ratio was 3.28-times higher in concordant than in non-concordant SISCOM patients [95%CI (1.90, 5.67)]. For extra-temporal lobe epilepsy, the seizure-free odds ratio was 2.44-times higher in concordant than in non-concordant SISCOM patients [95%CI (1.34, 4.43)]. Our data indicate that SISCOM has moderate sensitivity in localizing the epileptogenic zone and can provide complementary information when MRI is negative. Furthermore, SISCOM localization concordant with the gold standard demonstrates slightly higher predictive value for good surgical outcomes. Further research is required to explore the influence of SISCOM localization results in temporal lobe versus extra-temporal lobe epilepsy. Copyright © 2016 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.

Is the lymphatic drainage of lung cancer lobe-specific? A surgical appraisal.

PubMed

Riquet, Marc; Rivera, Caroline; Pricopi, Ciprian; Arame, Alex; Mordant, Pierre; Foucault, Christophe; Dujon, Antoine; Le Pimpec-Barthes, Françoise

2015-03-01

Nowadays, early-stage lung cancers are more frequently encountered. Selective lymph node (LN) dissection based on lobe-specific lymphatic pathway has been proposed. Our aim was to study nodal involvement according to tumour location. We reviewed 1779 lobectomized patients and analysed their pathological characteristics according to tumour location: Group 1 (G1), right upper lobe; Group 2 (G2), right middle lobe; Group 3 (G3), right lower lobe; Group 4 (G4), left upper division; Group 5 (G5), lingula; Group 6 (G6), left lower lobe. The pN status was recorded for each group to analyse the lymphatic spread of non-small-cell lung cancer (NSCLC) according to tumour location. The numbers and proportions of lobectomies in each group were 613 patients in G1 (59.2%), 64 in G2 (6.4%), 359 in G3 (34.6%), 404 in G4 (54.3%), 54 in G5 (7.3%) and 286 in G6 (38.4%). The rates of pN2 involvement were similar, whatever the group was, even when deciphering single- and multistation diseases. on the right side, single-station N2 disease was mainly found in the superior mediastinum (SM) for G1 (95%), and in the inferior for G3 (90%). On the left side, single-station N2 was mainly found in the SM in G4 (94%), and the inferior in G6 (48%). Whatever the side, in case of two-station involvement, both mediastina were concerned in 40% (in G4) to 81% of the case (in G3). Long-term survival rates were different in skip metastasis, single- and multistation involvement, but not between lobes. Tumour location is not a predictor of nodal metastasis pattern. In surgical treatment of NSCLC, complete systematic mediastinal LN dissection remains the only acceptable procedure from an oncological point of view. © The Author 2014. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

LMI1-like genes involved in leaf margin development of Brassica napus.

PubMed

Ni, Xiyuan; Liu, Han; Huang, Jixiang; Zhao, Jianyi

2017-06-01

In rapeseed (Brassica napus L.), leaf margins are variable and can be entire, serrate, or lobed. In our previous study, the lobed-leaf gene (LOBED-LEAF 1, BnLL1) was mapped to a 32.1 kb section of B. napus A10. Two LMI1-like genes, BnaA10g26320D and BnaA10g26330D, were considered the potential genes that controlled the lobed-leaf trait in rapeseed. In the present study, these two genes and another homologous gene (BnaC04g00850D) were transformed into Arabidopsis thaliana (L.) Heynh. plants to identify their functions. All three LMI1-like genes of B. napus produced serrate leaf margins. The expression analysis indicated that the expression level of BnaA10g26320D determined the difference between lobed- and entire-leaved lines in rapeseed. Therefore, it is likely that BnaA10g26320D corresponds to BnLL1.

Compound-specific isotope analysis: Questioning the origins of a trichloroethene plume

USGS Publications Warehouse

Eberts, S.M.; Braun, C.; Jones, S.

2008-01-01

Stable carbon isotope ratios of trichloroethene (TCE), cis-1,2- dichloroethene, and trans-1,2-dichloroethene were determined by use of gas chromatography-combustion-isotope ratio mass spectroscopy to determine whether compound-specific stable carbon isotopes could be used to help understand the origin and history of a TCE groundwater plume in Fort Worth, TX. Calculated ??13C values for total chlorinated ethenes in groundwater samples, which can approximate the ??13C of a spilled solvent if all degradation products are accounted for, were useful for determining whether separate lobes of the plume resulted from different sources. Most notably, values for one lobe, where tetrachloroethene (PCE) has been detected periodically, were outside the range for manufactured TCE but within the range for manufactured PCE, whereas values for a separate lobe, which is downgradient of reported TCE spills, were within the range for manufactured TCE. Copyright ?? Taylor & Francis Group, LLC.

THE RADIO CONTINUUM STRUCTURE OF CENTAURUS A AT 1.4 GHz

DOE Office of Scientific and Technical Information (OSTI.GOV)

Feain, I. J.; Cornwell, T. J.; Ekers, R. D.

2011-10-10

A 45 deg{sup 2} radio continuum imaging campaign of the nearest radio galaxy, Centaurus A, is reported. Using the Australia Telescope Compact Array and the Parkes 64 m radio telescope at 1.4 GHz, the spatial resolution of the resultant image is {approx}600 pc ({approx}50''), resolving the {approx}>500 kpc giant radio lobes with approximately five times better physical resolution compared to any previous image, and making this the most detailed radio continuum image of any radio galaxy to date. In this paper, we present these new data and discuss briefly some of the most interesting morphological features that we have discoveredmore » in the images. The two giant outer lobes are highly structured and considerably distinct. The southern part of the giant northern lobe naturally extends out from the northern middle lobe with uniformly north-streaming emission. The well known northern loop is resolved into a series of semi-regular shells with a spacing of approximately 25 kpc. The northern part of the giant northern lobe also contains identifiable filaments and partial ring structures. As seen in previous single-dish images at lower angular resolution, the giant southern lobe is not physically connected to the core at radio wavelengths. Almost the entirety of the giant southern lobe is resolved into a largely chaotic and mottled structure which appears considerably different (morphologically) to the diffuse regularity of the northern lobe. We report the discovery of a vertex and a vortex near the western boundary of the southern lobe, two striking, high surface brightness features that are named based on their morphology and not their dynamics (which are presently unknown). The vortex and vertex are modeled as reaccelerated lobe emission due to shocks from the active galactic nucleus itself or from the passage of a dwarf elliptical galaxy through the lobe. Preliminary polarimetric and spectral index studies support a plasma reacceleration model and could explain the origin of the Faraday rotation structure detected in the southern lobe. In addition, there are a series of low surface brightness wisps detected around the edges of both the giant lobes.« less

Changes in flip/flop splicing of astroglial AMPA receptors in human temporal lobe epilepsy.

PubMed

Seifert, Gerald; Schröder, Wolfgang; Hinterkeuser, Stefan; Schumacher, Thekla; Schramm, Johannes; Steinhäuser, Christian

2002-01-01

Recent data suggested a role for glial cells in epilepsy. This study sought to identify and functionally characterize AMPA receptors expressed by astrocytes in human hippocampal tissue resected from patients with intractable temporal lobe epilepsy. Patch-clamp and fast application methods were combined to investigate astrocytes in situ and after fresh isolation from the stratum radiatum of the hippocampal CA1 subfield. Relying on presurgical and histopathologic analysis, we divided human specimens into two groups, Ammon's horn sclerosis (AHS) and lesion-associated epilepsy. Fast application of glutamate and kainate evoked receptor currents in all cells studied. Reversal-potential analysis revealed an intermediate Ca2+ permeability of the receptor channels that did not vary between the two groups of patients. However, preapplication of the AMPA receptor-specific modulator, cyclothiazide, disclosed differences in flip-flop splicing. This treatment considerably enhanced the receptor conductance, with potentiation being significantly stronger in cells from AHS specimens compared with lesion-associated cells, suggesting upregulation of AMPA receptor flip splice variants in astrocytes of the sclerotic tissue. Compelling evidence has been accumulated showing direct and rapid signaling between neurons and glial cells. Our data suggest that in AHS patients, neuronally released glutamate will lead to an enhanced and prolonged depolarization of astrocytes, which might be involved in seizure generation and spread in this particular condition of human temporal lobe epilepsy.

Functional Similarity of Medial Superior Parietal Areas for Shift-Selective Attention Signals in Humans and Monkeys.

PubMed

Caspari, Natalie; Arsenault, John T; Vandenberghe, Rik; Vanduffel, Wim

2018-06-01

We continually shift our attention between items in the visual environment. These attention shifts are usually based on task relevance (top-down) or the saliency of a sudden, unexpected stimulus (bottom-up), and are typically followed by goal-directed actions. It could be argued that any species that can covertly shift its focus of attention will rely on similar, evolutionarily conserved neural substrates for processing such shift-signals. To address this possibility, we performed comparative fMRI experiments in humans and monkeys, combining traditional, and novel, data-driven analytical approaches. Specifically, we examined correspondences between monkey and human brain areas activated during covert attention shifts. When "shift" events were compared with "stay" events, the medial (superior) parietal lobe (mSPL) and inferior parietal lobes showed similar shift sensitivities across species, whereas frontal activations were stronger in monkeys. To identify, in a data-driven manner, monkey regions that corresponded with human shift-selective SPL, we used a novel interspecies beta-correlation strategy whereby task-related beta-values were correlated across voxels or regions-of-interest in the 2 species. Monkey medial parietal areas V6/V6A most consistently correlated with shift-selective human mSPL. Our results indicate that both species recruit corresponding, evolutionarily conserved regions within the medial superior parietal lobe for shifting spatial attention.

Effect of out-of-roundness on the performance of a diesel engine connecting-rod bearing

NASA Technical Reports Server (NTRS)

Vijayaraghavan, D.; Brewe, D. E.; Keith, T. G., Jr.

1993-01-01

In this paper, the dynamic performance of the Ruston and Hornsby VEB diesel engine connecting-rod bearing with circular and out-of-round profiles is analyzed. The effect of cavitation is considered by using a cavitation algorithm, which mimics JFO boundary conditions. The effect of mass inertia is accounted for by solving coupled nonlinear equations of motion. The journal profiles considered are circular, elliptical, semi-elliptical, and three lobe epicycloid. The predicted journal trajectory and other performance parameters for one complete load cycle are presented for all of the out-of-round profiles and are also compared with the predictions for the circular bearing.

Effect of out-of-roundness on the performance of a diesel engine connecting-rod bearing

NASA Technical Reports Server (NTRS)

Vijayaraghavan, D.; Brewe, D. E.; Keith, T. G., Jr.

1991-01-01

In this paper, the dynamic performance of the Ruston and Hornsby VEB diesel engine connecting-rod bearing with circular and out-of-round profiles is analyzed. The effect of cavitation is considered by using a cavitation algorithm, which mimics JFO boundary conditions. The effect of mass inertia is accounted for by solving coupled nonlinear equations of motion. The journal profiles considered are circular, elliptical, semi-elliptical, and three lobe epicycloid. The predicted journal trajectory and other performance parameters for one complete load cycle are presented for all of the out-of-round profiles and are also compared with the predictions for the circular bearing.

Integrated Analysis and Visualization of Group Differences in Structural and Functional Brain Connectivity: Applications in Typical Ageing and Schizophrenia.

PubMed

Langen, Carolyn D; White, Tonya; Ikram, M Arfan; Vernooij, Meike W; Niessen, Wiro J

2015-01-01

Structural and functional brain connectivity are increasingly used to identify and analyze group differences in studies of brain disease. This study presents methods to analyze uni- and bi-modal brain connectivity and evaluate their ability to identify differences. Novel visualizations of significantly different connections comparing multiple metrics are presented. On the global level, "bi-modal comparison plots" show the distribution of uni- and bi-modal group differences and the relationship between structure and function. Differences between brain lobes are visualized using "worm plots". Group differences in connections are examined with an existing visualization, the "connectogram". These visualizations were evaluated in two proof-of-concept studies: (1) middle-aged versus elderly subjects; and (2) patients with schizophrenia versus controls. Each included two measures derived from diffusion weighted images and two from functional magnetic resonance images. The structural measures were minimum cost path between two anatomical regions according to the "Statistical Analysis of Minimum cost path based Structural Connectivity" method and the average fractional anisotropy along the fiber. The functional measures were Pearson's correlation and partial correlation of mean regional time series. The relationship between structure and function was similar in both studies. Uni-modal group differences varied greatly between connectivity types. Group differences were identified in both studies globally, within brain lobes and between regions. In the aging study, minimum cost path was highly effective in identifying group differences on all levels; fractional anisotropy and mean correlation showed smaller differences on the brain lobe and regional levels. In the schizophrenia study, minimum cost path and fractional anisotropy showed differences on the global level and within brain lobes; mean correlation showed small differences on the lobe level. Only fractional anisotropy and mean correlation showed regional differences. The presented visualizations were helpful in comparing and evaluating connectivity measures on multiple levels in both studies.

The Impact of Sex and Language Dominance on Material-Specific Memory Before and After Left Temporal Lobe Surgery

ERIC Educational Resources Information Center

Helmstaedter, C.; Brosch, T.; Kurthen, M.; Elger, C. E.

2004-01-01

Recent findings raised evidence that in early-onset left temporal lobe epilepsy, women show greater functional plasticity for verbal memory than men. In particular, women with lesion- or epilepsy-driven atypical language dominance show an advantage over men. The question asked in this study was whether there is evidence of sex- and language…

Disordered high-frequency oscillation in face processing in schizophrenia patients

PubMed Central

Liu, Miaomiao; Pei, Guangying; Peng, Yinuo; Wang, Changming; Yan, Tianyi; Wu, Jinglong

2018-01-01

Abstract Schizophrenia is a complex disorder characterized by marked social dysfunctions, but the neural mechanism underlying this deficit is unknown. To investigate whether face-specific perceptual processes are influenced in schizophrenia patients, both face detection and configural analysis were assessed in normal individuals and schizophrenia patients by recording electroencephalogram (EEG) data. Here, a face processing model was built based on the frequency oscillations, and the evoked power (theta, alpha, and beta bands) and the induced power (gamma bands) were recorded while the subjects passively viewed face and nonface images presented in upright and inverted orientations. The healthy adults showed a significant face-specific effect in the alpha, beta, and gamma bands, and an inversion effect was observed in the gamma band in the occipital lobe and right temporal lobe. Importantly, the schizophrenia patients showed face-specific deficits in the low-frequency beta and gamma bands, and the face inversion effect in the gamma band was absent from the occipital lobe. All these results revealed face-specific processing in patients due to the disorder of high-frequency EEG, providing additional evidence to enrich future studies investigating neural mechanisms and serving as a marked diagnostic basis. PMID:29419668

Profiles of drug addicts in relation to personality variables and disorders.

PubMed

Carou, María; Romero, Estrella; Luengo, Mª Ángeles

2016-10-07

In recent decades, research has identified a set of impulsive/disinhibited personality variables closely associated with drug addiction. As well as this, disorders linked with these variables, such as ADHD and personality disorders, are being closely studied in the field of drug addiction. Although much knowledge has been accumulated about the relation of these variables and disorders taken separately, less is known about how these constructs allow identify-specific profiles within the drug dependent population to be identified. This work, on the basis of data collected on a sample of drug addicts in treatment, analyzes how impulsiveness, sensation seeking, self-control, ADHD and personality disorders contribute to identifying specific profiles of addicts. Cluster analysis allowed two profiles to be outlined according to these personality and psychopathology characteristics. Self-control, impulsiveness, impulsive and antisocial personality disorders, as well as scores in ADHD, emerge as the variables that contribute more to profile differentiation. One of these profiles (56.1% of participants) with a high disinhibition pattern, is associated with severe indicators of consumption and criminal career patterns. These results allow us to emphasize the role of personality and impulsiveness-related disorders in the identification of distinctive profiles within the addict population, and suggest the need to generate treatment strategies adapted to personal/psychopathology configurations of drug addicts.

Local Brain Activity Differences Between Herpes Zoster and Postherpetic Neuralgia Patients: A Resting-State Functional MRI Study.

PubMed

Cao, Song; Li, Ying; Deng, Wenwen; Qin, Bangyong; Zhang, Yi; Xie, Peng; Yuan, Jie; Yu, Buwei; Yu, Tian

2017-07-01

Herpes zoster (HZ) can develop into postherpetic neuralgia (PHN), both of which are painful diseases. PHN patients suffer chronic pain and emotional disorders. Previous studies showed that the PHN brain displayed abnormal activity and structural change, but the difference in brain activity between HZ and PHN is still not known. To identify regional brain activity changes in HZ and PHN brains with resting-state functional magnetic resonance imaging (rs-fMRI) technique, and to observe the differences between HZ and PHN patients. Observational study. University hospital. Regional homogeneity (ReHo) and fractional aptitude of low-frequency fluctuation (fALFF) methods were employed to analysis resting-state brain activity. Seventy-three age and gender matched patients (50 HZ, 23 PHN) and 55 healthy controls were enrolled. ReHo and fALFF changes were analyzed to detect the functional abnormality in HZ and PHN brains. Compared with healthy controls, HZ and PHN patients exhibited abnormal ReHo and fALFF values in classic pain-related brain regions (such as the frontal lobe, thalamus, insular, and cerebellum) as well as the brainstem, limbic lobe, and temporal lobe. When HZ developed to PHN, the activity in the vast area of the cerebellum significantly increased while that of some regions in the occipital lobe, temporal lobe, parietal lobe, and limbic lobe showed an apparent decrease. (a) Relatively short pain duration (mean 12.2 months) and small sample size (n = 23) for PHN group. (b) Comparisons at different time points (with paired t-tests) for each patient may minimize individual differences. HZ and PHN induced local brain activity changed in the pain matrix, brainstem, and limbic system. HZ chronification induced functional change in the cerebellum, occipital lobe, temporal lobe, parietal lobe, and limbic lobe. These brain activity changes may be correlated with HZ-PHN transition. Herpes zoster, postherpetic neuralgia, resting-state fMRI (rs-fMRI), regional homogeneity (ReHo), fractional aptitude of low-frequency fluctuation (fALFF).

The promise of subtraction ictal SPECT co-registered to MRI for improved seizure localization in pediatric epilepsies: Affecting factors and relationship to the surgical outcome

PubMed Central

Stamoulis, Catherine; Verma, Nishant; Kaulas, Himanshu; Halford, Jonathan J.; Duffy, Frank H.; Pearl, Phillip L.; Treves, S. Ted

2016-01-01

Objective Ictal SPECT is promising for accurate non-invasive localization of the epileptogenic brain tissue in focal epilepsies. However, high quality ictal scans require meticulous attention to the seizure onset. In a relatively large cohort of pediatric patients, this study investigated the impact of the timing of radiotracer injection, MRI findings and seizure characteristics on ictal SPECT localizations, and the relationship between concordance of ictal SPECT, scalp EEG and resected area with seizure freedom following epilepsy surgery. Methods Scalp EEG and ictal SPECT studies from 95 patients (48 males and 47 females, median age = 11 years, (25th, 75th) quartiles = (6.0, 14.75) years) with pharmacoresistant focal epilepsy and no prior epilepsy surgery were reviewed. The ictal SPECT result was examined as a function of the radiotracer injection delay, seizure duration, epilepsy etiology, cerebral lobe of seizure onset identified by EEG and MRI findings. Thirty two patients who later underwent epilepsy surgery had postoperative seizure freedom data at <1, 6 and 12 months. Results Sixty patients (63.2%) had positive SPECT localizations - 51 with a hyperperfused region that was concordant with the cerebral lobe of seizure origin identified by EEG and 9 with discordant localizations. Of these, 35 patients (58.3%) had temporal and 25 (41.7%) had extratemporal seizures. The ictal SPECT result was significantly correlated with the injection delay (p<0.01) and cerebral lobe of seizure onset (specifically frontal versus temporal; p = 0.02) but not MRI findings (p = 0.33), epilepsy etiology (p ≥ 0.27) or seizure duration (p = 0.20). Concordance of SPECT, scalp EEG and resected area was significantly correlated with seizure freedom at 6 months after surgery (p=0.04). Significance Ictal SPECT holds promise as a powerful source imaging tool for presurgical planning in pediatric epilepsies. To optimize the SPECT result the radiotracer injection delay should be minimized to ≤ 25 s, although the origin of seizure onset (specifically temporal versus frontal) also significantly impacts the localization. PMID:27918961

Comparison of brain volume abnormalities between ADHD and conduct disorder in adolescence

PubMed Central

Stevens, Michael C.; Haney-Caron, Emily

2012-01-01

Background Previous studies of brain structure abnormalities in conduct disorder and attention-deficit/hyperactivity disorder (ADHD) samples have been limited owing to cross-comorbidity, preventing clear understanding of which structural brain abnormalities might be specific to or shared by each disorder. To our knowledge, this study was the first direct comparison of grey and white matter volumes in diagnostically “pure” (i.e., no comorbidities) conduct disorder and ADHD samples. Methods Groups of adolescents with noncormobid conduct disorder and with noncomorbid, combined-subtype ADHD were compared with age- and sex-matched controls using DARTEL voxel-based analysis of T1-weighted brain structure images. Analysis of variance with post hoc analyses compared whole brain grey and white matter volumes among the groups. Results We included 24 adolescents in each study group. There was an overall 13% reduction in grey matter volume in adolescents with conduct disorder, reflecting numerous frontal, temporal, parietal and subcortical deficits. The same grey matter regions typically were not abnormal in those with ADHD. Deficits in frontal lobe regions previously identified in studies of patients with ADHD either were not detected, or group differences from controls were not as strong as those between the conduct disorder and control groups. White matter volume measurements did not differentiate conduct disorder and ADHD. Limitations Our modest sample sizes prevented meaningful examination of individual features of ADHD or conduct disorder, such as aggression, callousness, or hyperactive versus inattentive symptom subtypes. Conclusion The evidence supports theories of frontotemporal abnormalities in adolescents with conduct disorder, but raises questions about the prominence of frontal lobe and striatal structural abnormalities in those with noncomorbid, combined-subtype ADHD. The latter point is clinically important, given the widely held belief that ADHD is associated with numerous frontal lobe structural deficits, a conclusion that is not strongly supported following direct comparison of diagnostically pure groups. The results are important for future etiological studies, particularly those seeking to identify how early expression of specific brain structure abnormalities could potentiate the risk for antisocial behaviour. PMID:22663946

The promise of subtraction ictal SPECT co-registered to MRI for improved seizure localization in pediatric epilepsies: Affecting factors and relationship to the surgical outcome.

PubMed

Stamoulis, Catherine; Verma, Nishant; Kaulas, Himanshu; Halford, Jonathan J; Duffy, Frank H; Pearl, Phillip L; Treves, S Ted

2017-01-01

Ictal SPECT is promising for accurate non-invasive localization of the epileptogenic brain tissue in focal epilepsies. However, high quality ictal scans require meticulous attention to the seizure onset. In a relatively large cohort of pediatric patients, this study investigated the impact of the timing of radiotracer injection, MRI findings and seizure characteristics on ictal SPECT localizations, and the relationship between concordance of ictal SPECT, scalp EEG and resected area with seizure freedom following epilepsy surgery. Scalp EEG and ictal SPECT studies from 95 patients (48 males and 47 females, median age=11years, (25th, 75th) quartiles=(6.0, 14.75) years) with pharmacoresistant focal epilepsy and no prior epilepsy surgery were reviewed. The ictal SPECT result was examined as a function of the radiotracer injection delay, seizure duration, epilepsy etiology, cerebral lobe of seizure onset identified by EEG and MRI findings. Thirty two patients who later underwent epilepsy surgery had postoperative seizure freedom data at <1, 6 and 12 months. Sixty patients (63.2%) had positive SPECT localizations - 51 with a hyperperfused region that was concordant with the cerebral lobe of seizure origin identified by EEG and 9 with discordant localizations. Of these, 35 patients (58.3%) had temporal and 25 (41.7%) had extratemporal seizures. The ictal SPECT result was significantly correlated with the injection delay (p<0.01) and cerebral lobe of seizure onset (specifically frontal versus temporal; p=0.02) but not MRI findings (p=0.33), epilepsy etiology (p≥0.27) or seizure duration (p=0.20). Concordance of SPECT, scalp EEG and resected area was significantly correlated with seizure freedom at 6 months after surgery (p=0.04). Ictal SPECT holds promise as a powerful source imaging tool for presurgical planning in pediatric epilepsies. To optimize the SPECT result the radiotracer injection delay should be minimized to≤25s, although the origin of seizure onset (specifically temporal versus frontal) also significantly impacts the localization. Copyright © 2016 Elsevier B.V. All rights reserved.

Some Surprising Findings on the Involvement of the Parietal Lobe in Human Memory

PubMed Central

Olson, Ingrid R.; Berryhill, Marian

2009-01-01

The posterior parietal lobe is known to play some role in a far-flung list of mental processes: linking vision to action (saccadic eye movements, reaching, grasping), attending to visual space, numerical calculation, and mental rotation. Here we review findings from humans and monkeys that illuminate an untraditional function of this region: memory. Our review draws on neuroimaging findings that have repeatedly identified parietal lobe activations associated with short-term or working memory and episodic memory. We also discuss recent neuropsychological findings showing that individuals with parietal lobe damage exhibit both working memory and long-term memory deficits. These deficits are not ubiquitous; they are only evident under certain retrieval demands. Our review elaborates on these findings and evaluates various theories about the mechanistic role of the posterior parietal lobe in memory. The available data point towards the conclusion that the posterior parietal lobe plays an important role in memory retrieval irrespective of elapsed time. The two models that are best supported by existing data are the Attention to Memory Model and the Subjective Memory Model. We conclude by formalizing several open questions that are intended to encourage future research. PMID:18848635

Interval analysis of interictal EEG: pathology of the alpha rhythm in focal epilepsy

NASA Astrophysics Data System (ADS)

Pyrzowski, Jan; Siemiński, Mariusz; Sarnowska, Anna; Jedrzejczak, Joanna; Nyka, Walenty M.

2015-11-01

The contemporary use of interictal scalp electroencephalography (EEG) in the context of focal epilepsy workup relies on the visual identification of interictal epileptiform discharges. The high-specificity performance of this marker comes, however, at a cost of only moderate sensitivity. Zero-crossing interval analysis is an alternative to Fourier analysis for the assessment of the rhythmic component of EEG signals. We applied this method to standard EEG recordings of 78 patients divided into 4 subgroups: temporal lobe epilepsy (TLE), frontal lobe epilepsy (FLE), psychogenic nonepileptic seizures (PNES) and nonepileptic patients with headache. Interval-analysis based markers were capable of effectively discriminating patients with epilepsy from those in control subgroups (AUC~0.8) with diagnostic sensitivity potentially exceeding that of visual analysis. The identified putative epilepsy-specific markers were sensitive to the properties of the alpha rhythm and displayed weak or non-significant dependences on the number of antiepileptic drugs (AEDs) taken by the patients. Significant AED-related effects were concentrated in the theta interval range and an associated marker allowed for identification of patients on AED polytherapy (AUC~0.9). Interval analysis may thus, in perspective, increase the diagnostic yield of interictal scalp EEG. Our findings point to the possible existence of alpha rhythm abnormalities in patients with epilepsy.

Huntington's disease accelerates epigenetic aging of human brain and disrupts DNA methylation levels.

PubMed

Horvath, Steve; Langfelder, Peter; Kwak, Seung; Aaronson, Jeff; Rosinski, Jim; Vogt, Thomas F; Eszes, Marika; Faull, Richard L M; Curtis, Maurice A; Waldvogel, Henry J; Choi, Oi-Wa; Tung, Spencer; Vinters, Harry V; Coppola, Giovanni; Yang, X William

2016-07-01

Age of Huntington's disease (HD) motoric onset is strongly related to the number of CAG trinucleotide repeats in the huntingtin gene, suggesting that biological tissue age plays an important role in disease etiology. Recently, a DNA methylation based biomarker of tissue age has been advanced as an epigenetic aging clock. We sought to inquire if HD is associated with an accelerated epigenetic age. DNA methylation data was generated for 475 brain samples from various brain regions of 26 HD cases and 39 controls. Overall, brain regions from HD cases exhibit a significant epigenetic age acceleration effect (p=0.0012). A multivariate model analysis suggests that HD status increases biological age by 3.2 years. Accelerated epigenetic age can be observed in specific brain regions (frontal lobe, parietal lobe, and cingulate gyrus). After excluding controls, we observe a negative correlation (r=-0.41, p=5.5×10-8) between HD gene CAG repeat length and the epigenetic age of HD brain samples. Using correlation network analysis, we identify 11 co-methylation modules with a significant association with HD status across 3 broad cortical regions. In conclusion, HD is associated with an accelerated epigenetic age of specific brain regions and more broadly with substantial changes in brain methylation levels.

Huntington's disease accelerates epigenetic aging of human brain and disrupts DNA methylation levels

PubMed Central

Horvath, Steve; Langfelder, Peter; Kwak, Seung; Aaronson, Jeff; Rosinski, Jim; Vogt, Thomas F.; Eszes, Marika; Faull, Richard L.M.; Curtis, Maurice A.; Waldvogel, Henry J.; Choi, Oi-Wa; Tung, Spencer; Vinters, Harry V.; Coppola, Giovanni; Yang, X. William

2016-01-01

Age of Huntington's disease (HD) motoric onset is strongly related to the number of CAG trinucleotide repeats in the huntingtin gene, suggesting that biological tissue age plays an important role in disease etiology. Recently, a DNA methylation based biomarker of tissue age has been advanced as an epigenetic aging clock. We sought to inquire if HD is associated with an accelerated epigenetic age. DNA methylation data was generated for 475 brain samples from various brain regions of 26 HD cases and 39 controls. Overall, brain regions from HD cases exhibit a significant epigenetic age acceleration effect (p=0.0012). A multivariate model analysis suggests that HD status increases biological age by 3.2 years. Accelerated epigenetic age can be observed in specific brain regions (frontal lobe, parietal lobe, and cingulate gyrus). After excluding controls, we observe a negative correlation (r=−0.41, p=5.5×10−8) between HD gene CAG repeat length and the epigenetic age of HD brain samples. Using correlation network analysis, we identify 11 co-methylation modules with a significant association with HD status across 3 broad cortical regions. In conclusion, HD is associated with an accelerated epigenetic age of specific brain regions and more broadly with substantial changes in brain methylation levels. PMID:27479945

Analysis of the Human Prostate-Specific Proteome Defined by Transcriptomics and Antibody-Based Profiling Identifies TMEM79 and ACOXL as Two Putative, Diagnostic Markers in Prostate Cancer

PubMed Central

O'Hurley, Gillian; Busch, Christer; Fagerberg, Linn; Hallström, Björn M.; Stadler, Charlotte; Tolf, Anna; Lundberg, Emma; Schwenk, Jochen M.; Jirström, Karin; Bjartell, Anders; Gallagher, William M.; Uhlén, Mathias; Pontén, Fredrik

2015-01-01

To better understand prostate function and disease, it is important to define and explore the molecular constituents that signify the prostate gland. The aim of this study was to define the prostate specific transcriptome and proteome, in comparison to 26 other human tissues. Deep sequencing of mRNA (RNA-seq) and immunohistochemistry-based protein profiling were combined to identify prostate specific gene expression patterns and to explore tissue biomarkers for potential clinical use in prostate cancer diagnostics. We identified 203 genes with elevated expression in the prostate, 22 of which showed more than five-fold higher expression levels compared to all other tissue types. In addition to previously well-known proteins we identified two poorly characterized proteins, TMEM79 and ACOXL, with potential to differentiate between benign and cancerous prostatic glands in tissue biopsies. In conclusion, we have applied a genome-wide analysis to identify the prostate specific proteome using transcriptomics and antibody-based protein profiling to identify genes with elevated expression in the prostate. Our data provides a starting point for further functional studies to explore the molecular repertoire of normal and diseased prostate including potential prostate cancer markers such as TMEM79 and ACOXL. PMID:26237329

Temporal Lobe Epilepsy and the Selective Reminding Test: The Conventional 30-Minute Delay Suffices

ERIC Educational Resources Information Center

Bell, Brian D.; Fine, Jason; Dow, Christian; Seidenberg, Michael; Hermann, Bruce P.

2005-01-01

Conventional memory assessment may fail to identify memory dysfunction characterized by intact recall for a relatively brief period but rapid forgetting thereafter. This study assessed learning and retention after 30-min and 24-hr delays on auditory and visual selective reminding tests (SRTs) in right (n=20) and left (n=22) temporal lobe epilepsy…

Temporal Lobe Epilepsy Surgery Failures: A Review

PubMed Central

Harroud, Adil; Bouthillier, Alain; Weil, Alexander G.; Nguyen, Dang Khoa

2012-01-01

Patients with temporal lobe epilepsy (TLE) are refractory to antiepileptic drugs in about 30% of cases. Surgical treatment has been shown to be beneficial for the selected patients but fails to provide a seizure-free outcome in 20–30% of TLE patients. Several reasons have been identified to explain these surgical failures. This paper will address the five most common causes of TLE surgery failure (a) insufficient resection of epileptogenic mesial temporal structures, (b) relapse on the contralateral mesial temporal lobe, (c) lateral temporal neocortical epilepsy, (d) coexistence of mesial temporal sclerosis and a neocortical lesion (dual pathology); and (e) extratemporal lobe epilepsy mimicking TLE or temporal plus epilepsy. Persistence of epileptogenic mesial structures in the posterior temporal region and failure to distinguish mesial and lateral temporal epilepsy are possible causes of seizure persistence after TLE surgery. In cases of dual pathology, failure to identify a subtle mesial temporal sclerosis or regions of cortical microdysgenesis is a likely explanation for some surgical failures. Extratemporal epilepsy syndromes masquerading as or coexistent with TLE result in incomplete resection of the epileptogenic zone and seizure relapse after surgery. In particular, the insula may be an important cause of surgical failure in patients with TLE. PMID:22934162

Clinical and imaging features in lung torsion and description of a novel imaging sign.

PubMed

Hammer, Mark M; Madan, Rachna

2018-04-01

We set out to identify the clinical and imaging features seen in lung torsion, a rare but emergent diagnosis leading to vascular compromise of a lobe or entire lung. We retrospectively identified 10 patients with torsion who underwent chest CT. We evaluated each case for the presence of bronchial obstruction and abnormal fissure orientation. In seven patients who underwent contrast-enhanced CTs, we assessed for the presence of the antler sign, a novel sign seen on axial images demonstrating abnormal curvature of the artery and branches originating on one side. Five patients had right middle lobe (RML) torsion after right upper lobectomy, and the remaining occurred following thoracentesis, aortic surgery, or spontaneously. Chest CTs demonstrated bronchial obstruction in eight cases and presence of abnormal fissure orientation in four patients. The antler sign was present in three patients with whole-lung torsion and one patient with lobar torsion; vascular swirling was seen on 3-D images in all seven patients with contrast-enhanced CTs. Lung parenchymal imaging findings in lung torsion may be non-specific. Identification of the antler sign on contrast-enhanced chest CT, in combination with other signs such as bronchial obstruction and abnormal fissure orientation, indicates rotation of the bronchovascular pedicle. The presence of this sign should prompt further evaluation with 3-dimensional reconstructions.

Structural and functional analyses reveal the contributions of the C- and N-lobes of Argonaute protein to selectivity of RNA target cleavage.

PubMed

Dayeh, Daniel M; Kruithoff, Bradley C; Nakanishi, Kotaro

2018-04-27

Some gene transcripts have cellular functions as regulatory noncoding RNAs. For example, ∼23-nucleotide (nt)-long siRNAs are loaded into Argonaute proteins. The resultant ribonucleoprotein assembly, the RNA-induced silencing complex (RISC), cleaves RNAs that are extensively base-paired with the loaded siRNA. To date, base complementarity is recognized as the major determinant of specific target cleavage (or slicing), but little is known about how Argonaute inspects base pairing before cleavage. A hallmark of Argonaute proteins is their bilobal structure, but despite the significance of this structure for curtailing slicing activity against mismatched targets, the molecular mechanism remains elusive. Here, our structural and functional studies of a bilobed yeast Argonaute protein and its isolated catalytic C-terminal lobe (C-lobe) revealed that the C-lobe alone retains almost all properties of bilobed Argonaute: siRNA-duplex loading, passenger cleavage/ejection, and siRNA-dependent RNA cleavage. A 2.1 Å-resolution crystal structure revealed that the catalytic C-lobe mirrors the bilobed Argonaute in terms of guide-RNA recognition and that all requirements for transitioning to the catalytically active conformation reside in the C-lobe. Nevertheless, we found that in the absence of the N-terminal lobe (N-lobe), target RNAs are scanned for complementarity only at positions 5-14 on a 23-nt guide RNA before endonucleolytic cleavage, thereby allowing for some off-target cleavage. Of note, acquisition of an N-lobe expanded the range of the guide RNA strand used for inspecting target complementarity to positions 2-23. These findings offer clues to the evolution of the bilobal structure of catalytically active Argonaute proteins. © 2018 by The American Society for Biochemistry and Molecular Biology, Inc.

Verbal memory after temporal lobe epilepsy surgery in children: Do only mesial structures matter?

PubMed

Law, Nicole; Benifla, Mony; Rutka, James; Smith, Mary Lou

2017-02-01

Previous findings have been mixed regarding verbal memory outcome after left temporal lobectomy in children, and there are few studies comparing verbal memory change after lateral versus mesial temporal lobe resections. We compared verbal memory outcome associated with sparing or including the mesial structures in children who underwent left or right temporal lobe resection. We also investigated predictors of postsurgical verbal memory change. We retrospectively assessed verbal memory change approximately 1 year after unilateral temporal lobe epilepsy surgery using a list learning task. Participants included 23 children who underwent temporal lobe surgery with sparing of the mesial structures (13 left), and 40 children who had a temporal lobectomy that included resection of mesial structures (22 left). Children who underwent resection from the left lateral and mesial temporal lobe were the only group to show decline in verbal memory. Furthermore, when we considered language representation in the left temporal resection group, patients with left language representation and spared mesial structures showed essentially no change in verbal memory from preoperative to follow-up, whereas those with left language representation and excised mesial structures showed a decline. Postoperative seizure status had no effect on verbal memory change in children after left temporal lobe surgery. Finally, we found that patients with intact preoperative verbal memory experienced a significant decline compared to those with below average preoperative verbal memory. Our findings provide evidence of significant risk factors for verbal memory decline in children, specific to left mesial temporal lobe epilepsy. Children who undergo left temporal lobe surgery that includes mesial structures may be most vulnerable for verbal memory decline, especially when language representation is localized to the left hemisphere and when preoperative verbal memory is intact. Wiley Periodicals, Inc. © 2016 International League Against Epilepsy.

Comparative modelling of lower hybrid current drive with two launcher designs in the Tore Supra tokamak

NASA Astrophysics Data System (ADS)

Nilsson, E.; Decker, J.; Peysson, Y.; Artaud, J.-F.; Ekedahl, A.; Hillairet, J.; Aniel, T.; Basiuk, V.; Goniche, M.; Imbeaux, F.; Mazon, D.; Sharma, P.

2013-08-01

Fully non-inductive operation with lower hybrid current drive (LHCD) in the Tore Supra tokamak is achieved using either a fully active multijunction (FAM) launcher or a more recent ITER-relevant passive active multijunction (PAM) launcher, or both launchers simultaneously. While both antennas show comparable experimental efficiencies, the analysis of stability properties in long discharges suggest different current profiles. We present comparative modelling of LHCD with the two different launchers to characterize the effect of the respective antenna spectra on the driven current profile. The interpretative modelling of LHCD is carried out using a chain of codes calculating, respectively, the global discharge evolution (tokamak simulator METIS), the spectrum at the antenna mouth (LH coupling code ALOHA), the LH wave propagation (ray-tracing code C3PO), and the distribution function (3D Fokker-Planck code LUKE). Essential aspects of the fast electron dynamics in time, space and energy are obtained from hard x-ray measurements of fast electron bremsstrahlung emission using a dedicated tomographic system. LHCD simulations are validated by systematic comparisons between these experimental measurements and the reconstructed signal calculated by the code R5X2 from the LUKE electron distribution. An excellent agreement is obtained in the presence of strong Landau damping (found under low density and high-power conditions in Tore Supra) for which the ray-tracing model is valid for modelling the LH wave propagation. Two aspects of the antenna spectra are found to have a significant effect on LHCD. First, the driven current is found to be proportional to the directivity, which depends upon the respective weight of the main positive and main negative lobes and is particularly sensitive to the density in front of the antenna. Second, the position of the main negative lobe in the spectrum is different for the two launchers. As this lobe drives a counter-current, the resulting driven current profile is also different for the FAM and PAM launchers.

Astrocyte uncoupling as a cause of human temporal lobe epilepsy

PubMed Central

Bedner, Peter; Dupper, Alexander; Hüttmann, Kerstin; Müller, Julia; Herde, Michel K.; Dublin, Pavel; Deshpande, Tushar; Schramm, Johannes; Häussler, Ute; Haas, Carola A.; Henneberger, Christian; Theis, Martin

2015-01-01

Glial cells are now recognized as active communication partners in the central nervous system, and this new perspective has rekindled the question of their role in pathology. In the present study we analysed functional properties of astrocytes in hippocampal specimens from patients with mesial temporal lobe epilepsy without (n = 44) and with sclerosis (n = 75) combining patch clamp recording, K+ concentration analysis, electroencephalography/video-monitoring, and fate mapping analysis. We found that the hippocampus of patients with mesial temporal lobe epilepsy with sclerosis is completely devoid of bona fide astrocytes and gap junction coupling, whereas coupled astrocytes were abundantly present in non-sclerotic specimens. To decide whether these glial changes represent cause or effect of mesial temporal lobe epilepsy with sclerosis, we developed a mouse model that reproduced key features of human mesial temporal lobe epilepsy with sclerosis. In this model, uncoupling impaired K+ buffering and temporally preceded apoptotic neuronal death and the generation of spontaneous seizures. Uncoupling was induced through intraperitoneal injection of lipopolysaccharide, prevented in Toll-like receptor4 knockout mice and reproduced in situ through acute cytokine or lipopolysaccharide incubation. Fate mapping confirmed that in the course of mesial temporal lobe epilepsy with sclerosis, astrocytes acquire an atypical functional phenotype and lose coupling. These data suggest that astrocyte dysfunction might be a prime cause of mesial temporal lobe epilepsy with sclerosis and identify novel targets for anti-epileptogenic therapeutic intervention. PMID:25765328

Quantification of mu and non-mu opiate receptors in temporal lobe epilepsy using positron emission tomography.

PubMed

Mayberg, H S; Sadzot, B; Meltzer, C C; Fisher, R S; Lesser, R P; Dannals, R F; Lever, J R; Wilson, A A; Ravert, H T; Wagner, H N

1991-07-01

Alterations in a variety of neurotransmitter systems have been identified in experimental models of epilepsy and in brain tissue from patients with intractable temporal lobe seizures. The availability of new high-affinity radioligands permits the study of some neuroreceptors in vivo with positron emission tomography (PET). We previously characterized the in vivo binding of 11C-carfentanil, a potent and selective mu opiate receptor agonist, and described increases in 11C-carfentanil binding in the temporal neocortex of patients with unilateral temporal lobe epilepsy. These studies have been extended to 11C-diprenorphine, which labels mu, kappa, and delta opiate receptor subtypes. Paired measurements of opiate receptor binding were performed with PET using 11C-carfentanil and 11C-diprenorphine in patients with unilateral temporal lobe seizures. Carfentanil binding, reflecting changes in mu opiate receptors, was increased in the temporal neocortex and decreased in the amygdala on the side of the epileptic focus. Diprenorphine binding, reflecting mu as well as non-mu opiate subtypes, was not significantly different among regions in the focus and nonfocus temporal lobes. Regional glucose metabolism, measured using 18F-2-fluoro-2-deoxyglucose, was decreased in the mesial and lateral aspects of the temporal lobe ipsilateral to the epileptogenic focus. The variation in pattern of carfentanil and diprenorphine binding supports a differential regulation of opiate subtypes in unilateral temporal lobe epilepsy.

On the Processing of Semantic Aspects of Experience in the Anterior Medial Temporal Lobe: An Event-Related fMRI Study

ERIC Educational Resources Information Center

Meyer, Patric; Mecklinger, Axel; Friederici, Angela D.

2010-01-01

Recognition memory based on familiarity judgments is a form of declarative memory that has been repeatedly associated with the anterior medial temporal lobe. It has been argued that this region sustains familiarity-based recognition not only by retrieving item-specific information but also by coding for those semantic aspects of an event that…

Comprehension of Concrete and Abstract Words in Patients with Selective Anterior Temporal Lobe Resection and in Patients with Selective Amygdalo-Hippocampectomy

ERIC Educational Resources Information Center

Loiselle, Magalie; Rouleau, Isabelle; Nguyen, Dang Khoa; Dubeau, Francois; Macoir, Joel; Whatmough, Christine; Lepore, Franco; Joubert, Sven

2012-01-01

The role of the anterior temporal lobe (ATL) in semantic memory is now firmly established. There is still controversy, however, regarding the specific role of this region in processing various types of concepts. There have been reports of patients suffering from semantic dementia (SD), a neurodegenerative condition in which the ATL is damaged…

Auditory aura in nocturnal frontal lobe epilepsy: a red flag to suspect an extra-frontal epileptogenic zone.

PubMed

Ferri, Lorenzo; Bisulli, Francesca; Nobili, Lino; Tassi, Laura; Licchetta, Laura; Mostacci, Barbara; Stipa, Carlotta; Mainieri, Greta; Bernabè, Giorgia; Provini, Federica; Tinuper, Paolo

2014-11-01

To describe the anatomo-electro-clinical findings of patients with nocturnal hypermotor seizures (NHS) preceded by auditory symptoms, to evaluate the localizing value of auditory aura. Our database of 165 patients with nocturnal frontal lobe epilepsy (NFLE) diagnosis confirmed by videopolysomnography (VPSG) was reviewed, selecting those who reported an auditory aura as the initial ictal symptom in at least two NHS during their lifetime. Eleven patients were selected (seven males, four females). According to the anatomo-electro-clinical data, three groups were identified. Group 1 [defined epileptogenic zone (EZ)]: three subjects were studied with stereo-EEG. The EZ lay in the left superior temporal gyrus in two cases, whereas in the third case seizures arose from a dysplastic lesion located in the left temporal lobe. One of these three patients underwent left Heschl's gyrus resection, and is currently seizure-free. Group 2 (presumed EZ): three cases in which a presumed EZ was identified; in the left temporal lobe in two cases and in the left temporal lobe extending to the insula in one subject. Group 3 (uncertain EZ): five cases had anatomo-electro-clinical correlations discordant. This work suggests that auditory aura may be a helpful anamnestic feature suggesting an extra-frontal seizure origin. This finding could guide secondary investigations to improve diagnostic definition and selection of candidates for surgical treatment. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

Brain regions underlying word finding difficulties in temporal lobe epilepsy.

PubMed

Trebuchon-Da Fonseca, Agnes; Guedj, Eric; Alario, F-Xavier; Laguitton, Virginie; Mundler, Olivier; Chauvel, Patrick; Liegeois-Chauvel, Catherine

2009-10-01

Word finding difficulties are often reported by epileptic patients with seizures originating from the language dominant cerebral hemisphere, for example, in temporal lobe epilepsy. Evidence regarding the brain regions underlying this deficit comes from studies of peri-operative electro-cortical stimulation, as well as post-surgical performance. This evidence has highlighted a role for the anterior part of the dominant temporal lobe in oral word production. These conclusions contrast with findings from activation studies involving healthy speakers or acute ischaemic stroke patients, where the region most directly related to word retrieval appears to be the posterior part of the left temporal lobe. To clarify the neural basis of word retrieval in temporal lobe epilepsy, we tested forty-three drug-resistant temporal lobe epilepsy patients (28 left, 15 right). Comprehensive neuropsychological and language assessments were performed. Single spoken word production was elicited with picture or definition stimuli. Detailed analysis allowed the distinction of impaired word retrieval from other possible causes of naming failure. Finally, the neural substrate of the deficit was assessed by correlating word retrieval performance and resting-state brain metabolism in 18 fluoro-2-deoxy-d-glucose-Positron Emission Tomography. Naming difficulties often resulted from genuine word retrieval failures (anomic states), both in picture and in definition tasks. Left temporal lobe epilepsy patients showed considerably worse performance than right temporal lobe epilepsy patients. Performance was poorer in the definition than in the picture task. Across patients and the left temporal lobe epilepsy subgroup, frequency of anomic state was negatively correlated with resting-state brain metabolism in left posterior and basal temporal regions (Brodmann's area 20-37-39). These results show the involvement of posterior temporal regions, within a larger antero-posterior-basal temporal network, in the specific process of word retrieval in temporal lobe epilepsy. A tentative explanation for these findings is that epilepsy induces functional deafferentation between anterior temporal structures devoted to semantic processing and neocortical posterior temporal structures devoted to lexical processing.

Identified Serotonergic Modulatory Neurons Have Heterogeneous Synaptic Connectivity within the Olfactory System of Drosophila.

PubMed

Coates, Kaylynn E; Majot, Adam T; Zhang, Xiaonan; Michael, Cole T; Spitzer, Stacy L; Gaudry, Quentin; Dacks, Andrew M

2017-08-02

Modulatory neurons project widely throughout the brain, dynamically altering network processing based on an animal's physiological state. The connectivity of individual modulatory neurons can be complex, as they often receive input from a variety of sources and are diverse in their physiology, structure, and gene expression profiles. To establish basic principles about the connectivity of individual modulatory neurons, we examined a pair of identified neurons, the "contralaterally projecting, serotonin-immunoreactive deutocerebral neurons" (CSDns), within the olfactory system of Drosophila Specifically, we determined the neuronal classes providing synaptic input to the CSDns within the antennal lobe (AL), an olfactory network targeted by the CSDns, and the degree to which CSDn active zones are uniformly distributed across the AL. Using anatomical techniques, we found that the CSDns received glomerulus-specific input from olfactory receptor neurons (ORNs) and projection neurons (PNs), and networkwide input from local interneurons (LNs). Furthermore, we quantified the number of CSDn active zones in each glomerulus and found that CSDn output is not uniform, but rather heterogeneous, across glomeruli and stereotyped from animal to animal. Finally, we demonstrate that the CSDns synapse broadly onto LNs and PNs throughout the AL but do not synapse upon ORNs. Our results demonstrate that modulatory neurons do not necessarily provide purely top-down input but rather receive neuron class-specific input from the networks that they target, and that even a two cell modulatory network has highly heterogeneous, yet stereotyped, pattern of connectivity. SIGNIFICANCE STATEMENT Modulatory neurons often project broadly throughout the brain to alter processing based on physiological state. However, the connectivity of individual modulatory neurons to their target networks is not well understood, as modulatory neuron populations are heterogeneous in their physiology, morphology, and gene expression. In this study, we use a pair of identified serotonergic neurons within the Drosophila olfactory system as a model to establish a framework for modulatory neuron connectivity. We demonstrate that individual modulatory neurons can integrate neuron class-specific input from their target network, which is often nonreciprocal. Additionally, modulatory neuron output can be stereotyped, yet nonuniform, across network regions. Our results provide new insight into the synaptic relationships that underlie network function of modulatory neurons. Copyright © 2017 the authors 0270-6474/17/377318-14$15.00/0.

Focal retrograde amnesia and the episodic-semantic distinction.

PubMed

Wheeler, M A; McMillan, C T

2001-03-01

This article reports a review of focal retrograde amnesia (FRA), or the phenomenon of organically based severe memory loss restricted to retrograde, or pretraumatic, memory. Cases of FRA are classified according to the type of memory loss: episodic, semantic, or both. A few different clusters of the disorder were identified. Lesions to either the anterior temporal lobes or the posterior/visual cortex can result in an FRA that devastates retrograde episodic memory, while having smaller effects on semantic memory. A number of left-hemisphere patients have FRA confined to semantic memory. There are several additional examples of FRA following minor cerebral trauma that disrupts either episodic memory alone or both episodic and semantic memory that are not accompanied by evidence of structural brain lesions. We discuss these different profiles of FRA and their implications for the understanding of memory retrieval.

Wisconsin Card Sorting Test performance and impulsivity in patients with temporal lobe epilepsy: suicidal risk and suicide attempts.

PubMed

Garcia Espinosa, Arlety; Andrade Machado, René; Borges González, Susana; García González, María Eugenia; Pérez Montoto, Ariadna; Toledo Sotomayor, Guillermo

2010-01-01

The goal of the study described here was to determine if executive dysfunction and impulsivity are related to risk for suicide and suicide attempts in patients with temporal lobe epilepsy. Forty-two patients with temporal lobe epilepsy were recruited. A detailed medical history, neurological examination, serial EEGs, Mini-International Neuropsychiatric Interview, executive function, and MRI were assessed. Multiple regression analysis was carried out to examine predictive associations between clinical variables and Wisconsin Card Sorting Test measures. Patients' scores on the Risk for Suicide Scale (n=24) were greater than 7, which means they had the highest relative risk for suicide attempts. Family history of psychiatric disease, current major depressive episode, left temporal lobe epilepsy, and perseverative responses and total errors on the Wisconsin Card Sorting Test increased by 6.3 and 7.5 suicide risk and suicide attempts, respectively. Executive dysfunction (specifically perseverative responses and more total errors) contributed greatly to suicide risk. Executive performance has a major impact on suicide risk and suicide attempts in patients with temporal lobe epilepsy. 2009 Elsevier Inc. All rights reserved.

Evidence for a left-over-right inhibitory mechanism during figural creative thinking in healthy nonartists.

PubMed

Huang, Peiyu; Qiu, Lihua; Shen, Lin; Zhang, Yong; Song, Zhe; Qi, Zhiguo; Gong, Qiyong; Xie, Peng

2013-10-01

As a complex mental process, creativity requires the coordination of multiple brain regions. Previous pathological research on figural creativity has indicated that there is a mechanism by which the left side of the brain inhibits the activities of the right side of the brain during figural creative thinking, but this mechanism has not been directly demonstrated. In this study, we used functional magnetic resonance imaging (fMRI) to demonstrate the existence of this inhibitory mechanism in young adults (15 women, 11 men, mean age: 22 years) that were not artists. By making comparisons between brain activity during creative and uncreative tasks, we found increased activity in the left middle and inferior frontal lobe and strong decreases in activity in the right middle frontal lobe and the left inferior parietal lobe. As such, these data suggest that the left frontal lobe may inhibit the right hemisphere during figural creative thinking in normal people. Moreover, removal of this inhibition by practicing artistry or through specific damage to the left frontal lobe may facilitate the emergence of artistic creativity. Copyright © 2012 Wiley Periodicals, Inc.

Personal semantic memory: insights from neuropsychological research on amnesia.

PubMed

Grilli, Matthew D; Verfaellie, Mieke

2014-08-01

This paper provides insight into the cognitive and neural mechanisms of personal semantic memory, knowledge that is specific and unique to individuals, by reviewing neuropsychological research on stable amnesia secondary to medial temporal lobe damage. The results reveal that personal semantic memory does not depend on a unitary set of cognitive and neural mechanisms. Findings show that autobiographical fact knowledge reflects an experience-near type of personal semantic memory that relies on the medial temporal lobe for retrieval, albeit less so than personal episodic memory. Additional evidence demonstrates that new autobiographical fact learning likely relies on the medial temporal lobe, but the extent to which remains unclear. Other findings show that retrieval of personal traits/roles and new learning of personal traits/roles and thoughts/beliefs are independent of the medial temporal lobe and thus may represent highly conceptual types of personal semantic memory that are stored in the neocortex. Published by Elsevier Ltd.

Enhancing the efficiency of a three-lobe roots blower by means of by-passing gas to the working cavity through an ejector adaptor

NASA Astrophysics Data System (ADS)

Vizgalov, S. V.; Volkov, M. V.; Chekushkin, G. N.; Khisameev, I. G.

2017-08-01

A positive displacement Roots blower with two- or three-lobe straight-tooth or twisted rotors demonstrates high performance with small specific dimensions and is used to boost internal combustion engines, aerate tanks of treatment facilities, is employed in air and gas transport systems in the food, petrochemical and metallurgical industry. It is common knowledge that several solutions have been implemented in Roots blower designs with straight-tooth with three-lobe or more-lobes rotors. It is more practical to bypass a portion of the compressed gas to the working cavity of the blower through an ejector. The purpose of developing a mathematical model for a blower working in conjunction with an ejector adapter and the further research is to determine the efficiency of this scheme un-der different discharge pressure conditions and different ejector active flow temperatures (the gas cooling effect before the nozzle).

A Pencil Rescues Impaired Performance on a Visual Discrimination Task in Patients with Medial Temporal Lobe Lesions

ERIC Educational Resources Information Center

Knutson, Ashley R.; Hopkins, Ramona O.; Squire, Larry R.

2013-01-01

We tested proposals that medial temporal lobe (MTL) structures support not just memory but certain kinds of visual perception as well. Patients with hippocampal lesions or larger MTL lesions attempted to identify the unique object among twin pairs of objects that had a high degree of feature overlap. Patients were markedly impaired under the more…

Anterior temporal cortex and semantic memory: reconciling findings from neuropsychology and functional imaging.

PubMed

Rogers, Timothy T; Hocking, Julia; Noppeney, Uta; Mechelli, Andrea; Gorno-Tempini, Maria Luisa; Patterson, Karalyn; Price, Cathy J

2006-09-01

Studies of semantic impairment arising from brain disease suggest that the anterior temporal lobes are critical for semantic abilities in humans; yet activation of these regions is rarely reported in functional imaging studies of healthy controls performing semantic tasks. Here, we combined neuropsychological and PET functional imaging data to show that when healthy subjects identify concepts at a specific level, the regions activated correspond to the site of maximal atrophy in patients with relatively pure semantic impairment. The stimuli were color photographs of common animals or vehicles, and the task was category verification at specific (e.g., robin), intermediate (e.g., bird), or general (e.g., animal) levels. Specific, relative to general, categorization activated the antero-lateral temporal cortices bilaterally, despite matching of these experimental conditions for difficulty. Critically, in patients with atrophy in precisely these areas, the most pronounced deficit was in the retrieval of specific semantic information.

Visual Scanning Patterns and Executive Function in Relation to Facial Emotion Recognition in Aging

PubMed Central

Circelli, Karishma S.; Clark, Uraina S.; Cronin-Golomb, Alice

2012-01-01

Objective The ability to perceive facial emotion varies with age. Relative to younger adults (YA), older adults (OA) are less accurate at identifying fear, anger, and sadness, and more accurate at identifying disgust. Because different emotions are conveyed by different parts of the face, changes in visual scanning patterns may account for age-related variability. We investigated the relation between scanning patterns and recognition of facial emotions. Additionally, as frontal-lobe changes with age may affect scanning patterns and emotion recognition, we examined correlations between scanning parameters and performance on executive function tests. Methods We recorded eye movements from 16 OA (mean age 68.9) and 16 YA (mean age 19.2) while they categorized facial expressions and non-face control images (landscapes), and administered standard tests of executive function. Results OA were less accurate than YA at identifying fear (p<.05, r=.44) and more accurate at identifying disgust (p<.05, r=.39). OA fixated less than YA on the top half of the face for disgust, fearful, happy, neutral, and sad faces (p’s<.05, r’s≥.38), whereas there was no group difference for landscapes. For OA, executive function was correlated with recognition of sad expressions and with scanning patterns for fearful, sad, and surprised expressions. Conclusion We report significant age-related differences in visual scanning that are specific to faces. The observed relation between scanning patterns and executive function supports the hypothesis that frontal-lobe changes with age may underlie some changes in emotion recognition. PMID:22616800

Comparative Transcriptional Profiling of the Axolotl Limb Identifies a Tripartite Regeneration-Specific Gene Program

PubMed Central

Knapp, Dunja; Schulz, Herbert; Rascon, Cynthia Alexander; Volkmer, Michael; Scholz, Juliane; Nacu, Eugen; Le, Mu; Novozhilov, Sergey; Tazaki, Akira; Protze, Stephanie; Jacob, Tina; Hubner, Norbert; Habermann, Bianca; Tanaka, Elly M.

2013-01-01

Understanding how the limb blastema is established after the initial wound healing response is an important aspect of regeneration research. Here we performed parallel expression profile time courses of healing lateral wounds versus amputated limbs in axolotl. This comparison between wound healing and regeneration allowed us to identify amputation-specific genes. By clustering the expression profiles of these samples, we could detect three distinguishable phases of gene expression – early wound healing followed by a transition-phase leading to establishment of the limb development program, which correspond to the three phases of limb regeneration that had been defined by morphological criteria. By focusing on the transition-phase, we identified 93 strictly amputation-associated genes many of which are implicated in oxidative-stress response, chromatin modification, epithelial development or limb development. We further classified the genes based on whether they were or were not significantly expressed in the developing limb bud. The specific localization of 53 selected candidates within the blastema was investigated by in situ hybridization. In summary, we identified a set of genes that are expressed specifically during regeneration and are therefore, likely candidates for the regulation of blastema formation. PMID:23658691

Epilepsy in multiple sclerosis: The role of temporal lobe damage.

PubMed

Calabrese, M; Castellaro, M; Bertoldo, A; De Luca, A; Pizzini, F B; Ricciardi, G K; Pitteri, M; Zimatore, S; Magliozzi, R; Benedetti, M D; Manganotti, P; Montemezzi, S; Reynolds, R; Gajofatto, A; Monaco, S

2017-03-01

Although temporal lobe pathology may explain some of the symptoms of multiple sclerosis (MS), its role in the pathogenesis of seizures has not been clarified yet. To investigate the role of temporal lobe damage in MS patients suffering from epilepsy, by the application of advanced multimodal 3T magnetic resonance imaging (MRI) analysis. A total of 23 relapsing remitting MS patients who had epileptic seizures (RRMS/E) and 23 disease duration matched RRMS patients without any history of seizures were enrolled. Each patient underwent advanced 3T MRI protocol specifically conceived to evaluate grey matter (GM) damage. This includes grey matter lesions (GMLs) identification, evaluation of regional cortical thickness and indices derived from the Neurite Orientation Dispersion and Density Imaging model. Regional analysis revealed that in RRMS/E, the regions most affected by GMLs were the hippocampus (14.2%), the lateral temporal lobe (13.5%), the cingulate (10.0%) and the insula (8.4%). Cortical thinning and alteration of diffusion metrics were observed in several regions of temporal lobe, in insular cortex and in cingulate gyrus of RRMS/E compared to RRMS ( p< 0.05 for all comparisons). Compared to RRMS, RRMS/E showed more severe damage of temporal lobe, which exceeds what would be expected on the basis of the global GM damage observed.

Epigenetic control of learning and memory in Drosophila by Tip60 HAT action.

PubMed

Xu, Songjun; Wilf, Rona; Menon, Trisha; Panikker, Priyalakshmi; Sarthi, Jessica; Elefant, Felice

2014-12-01

Disruption of epigenetic gene control mechanisms in the brain causes significant cognitive impairment that is a debilitating hallmark of most neurodegenerative disorders, including Alzheimer's disease (AD). Histone acetylation is one of the best characterized of these epigenetic mechanisms that is critical for regulating learning- and memory- associated gene expression profiles, yet the specific histone acetyltransferases (HATs) that mediate these effects have yet to be fully characterized. Here, we investigate an epigenetic role for the HAT Tip60 in learning and memory formation using the Drosophila CNS mushroom body (MB) as a well-characterized cognition model. We show that Tip60 is endogenously expressed in the Kenyon cells, the intrinsic neurons of the MB, and in the MB axonal lobes. Targeted loss of Tip60 HAT activity in the MB causes thinner and shorter axonal lobes while increasing Tip60 HAT levels cause no morphological defects. Functional consequences of both loss and gain of Tip60 HAT levels in the MB are evidenced by defects in immediate-recall memory. Our ChIP-Seq analysis reveals that Tip60 target genes are enriched for functions in cognitive processes, and, accordingly, key genes representing these pathways are misregulated in the Tip60 HAT mutant fly brain. Remarkably, we find that both learning and immediate-recall memory deficits that occur under AD-associated, amyloid precursor protein (APP)-induced neurodegenerative conditions can be effectively rescued by increasing Tip60 HAT levels specifically in the MB. Together, our findings uncover an epigenetic transcriptional regulatory role for Tip60 in cognitive function and highlight the potential of HAT activators as a therapeutic option for neurodegenerative disorders. Copyright © 2014 by the Genetics Society of America.

Social cognition dysfunctions in patients with epilepsy: Evidence from patients with temporal lobe and idiopathic generalized epilepsies.

PubMed

Realmuto, Sabrina; Zummo, Leila; Cerami, Chiara; Agrò, Luigi; Dodich, Alessandra; Canessa, Nicola; Zizzo, Andrea; Fierro, Brigida; Daniele, Ornella

2015-06-01

Despite an extensive literature on cognitive impairments in focal and generalized epilepsy, only a few number of studies specifically explored social cognition disorders in epilepsy syndromes. The aim of our study was to investigate social cognition abilities in patients with temporal lobe epilepsy (TLE) and in patients with idiopathic generalized epilepsy (IGE). Thirty-nine patients (21 patients with TLE and 18 patients with IGE) and 21 matched healthy controls (HCs) were recruited. All subjects underwent a basic neuropsychological battery plus two experimental tasks evaluating emotion recognition from facial expression (Ekman-60-Faces test, Ek-60F) and mental state attribution (Story-based Empathy Task, SET). In particular, the latter is a newly developed task that assesses the ability to infer others' intentions (i.e., intention attribution - IA) and emotions (i.e., emotion attribution - EA) compared with a control condition of physical causality (i.e., causal inferences - CI). Compared with HCs, patients with TLE showed significantly lower performances on both social cognition tasks. In particular, all SET subconditions as well as the recognition of negative emotions were significantly impaired in patients with TLE vs. HCs. On the contrary, patients with IGE showed impairments on anger recognition only without any deficit at the SET task. Emotion recognition deficits occur in patients with epilepsy, possibly because of a global disruption of a pathway involving frontal, temporal, and limbic regions. Impairments of mental state attribution specifically characterize the neuropsychological profile of patients with TLE in the context of the in-depth temporal dysfunction typical of such patients. Impairments of socioemotional processing have to be considered as part of the neuropsychological assessment in both TLE and IGE in view of a correct management and for future therapeutic interventions. Copyright © 2015 Elsevier Inc. All rights reserved.

Polar rain: Solar coronal electrons in the Earth's magnetosphere

NASA Technical Reports Server (NTRS)

Fairfield, D. H.; Scudder, J. D.

1984-01-01

Low energy electron measurements collected by ISEE 1 reveal the frequent presence of field-aligned fluxes of few hundred eV electrons in he geomagnetic tail lobes. In the northern tail lobe these electrons are most prominent when the interplanetary magnetic field is directed away from the Sun. This characteristic helps identify the electrons as polar rain electrons. By mapping the tail lobe velocity distribution function into the solar wind, previous suggestions that the polar rain is indeed of solar wind origin and is due to the access of electrons to the magnetotail lobe were confirmed. It was demonstrated that the moe energetic component of the polar rain is composed of electrons from the solar wind strahl - a field-aligned component of the solar wind which is difficult to measure but which is thought to be caused by the collisionless transit of hundred eV electrons from the inner solar corona to 1 AU.

Ultralow frequency waves in the magnetotails of the earth and the outer planets

NASA Technical Reports Server (NTRS)

Khurana, Krishan K.; Chen, Sheng H.; Hammond, C. M.; Kivelson, Margaret G.

1992-01-01

Ultralow frequency waves with periods greater than two minutes are characteristic features of planetary magnetotails. At Jupiter, changes in the wave characteristics across the boundary between the plasma sheet and the lobe have been used to identify this important plasma boundary. In the terrestrial lobes the wave amplitude can be relatively large, especially during intervals of intense geomagnetic activity. The wave power seen in the lobes of the magnetotails of the earth, Jupiter, Saturn and Uranus is evaluated to evaluate a proposal by Smith et al. that the propagating waves generated by the Kelvin-Helmholtz instability on the magnetopause can heat the plasma through a resonant absorption of these waves. The results indicate that the wave power in the lobes is generally small and can be easily understood in the framework of coupled MHD waves generated in the plasma sheet.

Association between lesion location and language function in adult glioma using voxel-based lesion-symptom mapping.

PubMed

Banerjee, Pia; Leu, Kevin; Harris, Robert J; Cloughesy, Timothy F; Lai, Albert; Nghiemphu, Phioanh L; Pope, Whitney B; Bookheimer, Susan Y; Ellingson, Benjamin M

2015-01-01

Management of language difficulties is an important aspect of clinical care for glioma patients, and accurately identifying the possible language deficits in patients based on lesion location would be beneficial to clinicians. To that end, we examined the relationship between lesion presence and language performance on tests of receptive language and expressive language using a highly specific voxel-based lesion-symptom mapping (VLSM) approach in glioma patients. 98 adults with primary glioma, who were pre-surgical candidates, were administered seven neurocognitive tests within the domains of receptive language and expressive language. The association between language performance and lesion presence was examined using VLSM. Statistical parametric maps were created for each test, and composite maps for both receptive language and expressive language were created to display the significant voxels common to all tests within these language domains. We identified clusters of voxels with a significant relationship between lesion presence and language performance. All tasks were associated with several white matter pathways. The receptive language tasks were additionally all associated with regions primarily within the lateral temporal lobe and medial temporal lobe. In contrast, the expressive language tasks shared little overlap, despite each task being independently associated with large anatomic areas. Our findings identify the key anatomic structures involved in language functioning in adult glioma patients using an innovative lesion analysis technique and suggest that expressive language abilities may be more task-dependent and distributed than receptive language abilities.

Abnormal regional cerebral blood flow in childhood autism.

PubMed

Ohnishi, T; Matsuda, H; Hashimoto, T; Kunihiro, T; Nishikawa, M; Uema, T; Sasaki, M

2000-09-01

Neuroimaging studies of autism have shown abnormalities in the limbic system and cerebellar circuits and additional sites. These findings are not, however, specific or consistent enough to build up a coherent theory of the origin and nature of the brain abnormality in autistic patients. Twenty-three children with infantile autism and 26 non-autistic controls matched for IQ and age were examined using brain-perfusion single photon emission computed tomography with technetium-99m ethyl cysteinate dimer. In autistic subjects, we assessed the relationship between regional cerebral blood flow (rCBF) and symptom profiles. Images were anatomically normalized, and voxel-by-voxel analyses were performed. Decreases in rCBF in autistic patients compared with the control group were identified in the bilateral insula, superior temporal gyri and left prefrontal cortices. Analysis of the correlations between syndrome scores and rCBF revealed that each syndrome was associated with a specific pattern of perfusion in the limbic system and the medial prefrontal cortex. The results confirmed the associations of (i) impairments in communication and social interaction that are thought to be related to deficits in the theory of mind (ToM) with altered perfusion in the medial prefrontal cortex and anterior cingulate gyrus, and (ii) the obsessive desire for sameness with altered perfusion in the right medial temporal lobe. The perfusion abnormalities seem to be related to the cognitive dysfunction observed in autism, such as deficits in ToM, abnormal responses to sensory stimuli, and the obsessive desire for sameness. The perfusion patterns suggest possible locations of abnormalities of brain function underlying abnormal behaviour patterns in autistic individuals.

Executive functioning and depressed mood before and after unilateral frontal lobe resection for intractable epilepsy.

PubMed

Dulay, Mario F; Busch, Robyn M; Chapin, Jessica S; Jehi, Lara; Najm, Imad

2013-06-01

Executive dysfunction occurs in a variety of patients who have sustained damage to the frontal lobes. In individuals with frontal lobe epilepsy (FLE) or after unilateral frontal lobe resection (FLR), a unique neuropsychological profile linking executive functions (EF) with the frontal lobe has been elusive, with conflicting findings in the literature. Some studies show greater risk of executive impairment with left-sided FLE or FLR, while others report greater risk for right-sided patients. Some studies report no relationship between FLE and EF impairment, while others show EF impairment regardless of side of seizure foci or surgery. In patients with temporal lobe epilepsy, executive dysfunction is associated with depressed mood possibly reflecting disruption of cortical-limbic pathways and/or frontal-striatal circuitry. Although not previously examined, depression level may affect executive functioning in those with FLE or FLR. We hypothesized that FLE patients with poor mood state would show greater executive dysfunction than FLE patients without poor mood state. The relationship among EF, side of surgery and depressed mood before and 8 months after unilateral FLR was evaluated in 64 patients using validated measures of EF and mood state (Beck Depression Inventory-II). Results indicated that individuals with depressed mood before surgery had greater difficulty on a task of mental flexibility compared to patients without preoperative depressed mood. Further, individuals with depressed mood before surgery had significant increases in perseverative responding and completed fewer categories on a card-sorting task after surgery compared to patients without preoperative depressed mood. Regression analyses showed that among side of surgery, seizure freedom status after surgery and depression status, only pre-surgical depression status explained a significant amount of variance in executive functioning performance after surgery. Results suggest that clinically elevated depressive symptoms before surgery are a risk factor for moderate declines in EF after surgery. Results may be attributable to reduced cognitive reserve in patients with depressive symptoms, or may reflect a common cause attributable to damage to unilateral dorsal and ventral lateral frontal lobe. Copyright © 2012 Elsevier Ltd. All rights reserved.

Impaired social cognition in patients with interictal epileptiform discharges in the frontal lobe.

PubMed

Hu, Ying; Jiang, Yubao; Hu, Panpan; Ma, Huijuan; Wang, Kai

2016-04-01

Patients with epilepsy frequently experience cognitive impairments, including impairments in social cognition. However, there is a lack of direct examinations of the affective and cognitive aspects of social cognition in such patients. The neural correlates remain to be identified. The present study was designed to examine the degree of impairments in different aspects of social cognition including empathy, emotion recognition, and Theory of Mind (ToM) in patients with epilepsy. In addition, we further explored factors related to the impairments, highlighting the specific importance of the frontal region. After 24-hour EEG monitoring, 53 patients with epilepsy were administered a neuropsychological battery of tests for basic intelligence assessment and then were tested with the Interpersonal Reactive Index, the "Yoni" task, the Emotion Recognition Test, the Reading the Mind in the Eyes test, and other neuropsychological tests. The clinical variables potentially affecting the ability to accomplish these tests were taken into account. We divided the patients into those having frontal lobe interictal epileptiform discharges (group with frontal IEDs) and those with seizures originating outside the frontal or temporal lobes (group with extrafrontal IEDs). Sixty healthy individuals served as controls. The group with frontal IEDs achieved the most severe deficits in emotion recognition, ToM, and cognitive empathy, while affective empathy was intact. Moreover, the performance scores of empathy in the group with frontal IEDs were selectively correlated with their executive function scores, which are believed to be associated with orbitofrontal functioning. In contrast, patients with epilepsies not originating from the frontal or temporal lobes may also be at risk of impairments in social cognition, albeit to a lesser extent. The preliminary findings suggest that patients with epilepsy, especially those having frontal lobe interictal epileptiform discharges, have associated general social cognition deficits. At the clinical level, these results are in line with previous findings regarding social cognition and the importance of the prefrontal area in the integration of cognition and affect. At the theoretical level, our findings also provide evidence for the functional independence of cognitive from affective aspects of empathy. Copyright © 2016 Elsevier Inc. All rights reserved.

Analysis of the Metabolic and Structural Brain Changes in Patients With Torture-Related Post-Traumatic Stress Disorder (TR-PTSD) Using 18F-FDG PET and MRI

PubMed Central

Zandieh, Shahin; Bernt, Reinhard; Knoll, Peter; Wenzel, Thomas; Hittmair, Karl; Haller, Joerg; Hergan, Klaus; Mirzaei, Siroos

2016-01-01

Abstract Many people exposed to torture later suffer from torture-related post-traumatic stress disorder (TR-PTSD). The aim of this study was to analyze the morphologic and functional brain changes in patients with TR-PTSD using magnetic resonance imaging (MRI) and positron emission tomography (PET). This study evaluated 19 subjects. Thirteen subcortical brain structures were evaluated using FSL software. On the T1-weighted images, normalized brain volumes were measured using SIENAX software. The study compared the volume of the brain and 13 subcortical structures in 9 patients suffering from TR-PTSD after torture and 10 healthy volunteers (HV). Diffusion-weighted imaging (DWI) was performed in the transverse plane. In addition, the 18F-FDG PET data were evaluated to identify the activity of the elected regions. The mean left hippocampal volume for the TR-PTSD group was significantly lower than in the HV group (post hoc test (Bonferroni) P < 0.001). There was a significant difference between the gray matter volume of the patients with TR-PTSD and the HV group (post hoc test (Bonferroni) P < 0.001). The TR-PTSD group showed low significant expansion of the ventricles in contrast to the HV group (post hoc test (Bonferroni) P < 0.001). Diffusion-weighted imaging revealed significant differences in the right frontal lobe and the left occipital lobe between the TR-PTSD and HV group (post hoc test (Bonferroni) P < 0.001). Moderate hypometabolism was noted in the occipital lobe in 6 of the 9 patients with TR-PTSD, in the temporal lobe in 1 of the 9 patients, and in the caudate nucleus in 5 of the 9 patients. In 2 cases, additional hypometabolism was observed in the posterior cingulate cortex and in the parietal and frontal lobes. The findings from this study show that TR-PTSD might have a deleterious influence on a set of specific brain structures. This study also demonstrated that PET combined with MRI is sensitive in detecting possible metabolic and structural brain changes in TR-PTSD. PMID:27082610

Analysis of the Metabolic and Structural Brain Changes in Patients With Torture-Related Post-Traumatic Stress Disorder (TR-PTSD) Using ¹⁸F-FDG PET and MRI.

PubMed

Zandieh, Shahin; Bernt, Reinhard; Knoll, Peter; Wenzel, Thomas; Hittmair, Karl; Haller, Joerg; Hergan, Klaus; Mirzaei, Siroos

2016-04-01

Many people exposed to torture later suffer from torture-related post-traumatic stress disorder (TR-PTSD). The aim of this study was to analyze the morphologic and functional brain changes in patients with TR-PTSD using magnetic resonance imaging (MRI) and positron emission tomography (PET). This study evaluated 19 subjects. Thirteen subcortical brain structures were evaluated using FSL software. On the T1-weighted images, normalized brain volumes were measured using SIENAX software. The study compared the volume of the brain and 13 subcortical structures in 9 patients suffering from TR-PTSD after torture and 10 healthy volunteers (HV). Diffusion-weighted imaging (DWI) was performed in the transverse plane. In addition, the 18F-FDG PET data were evaluated to identify the activity of the elected regions. The mean left hippocampal volume for the TR-PTSD group was significantly lower than in the HV group (post hoc test (Bonferroni) P < 0.001). There was a significant difference between the gray matter volume of the patients with TR-PTSD and the HV group (post hoc test (Bonferroni) P < 0.001). The TR-PTSD group showed low significant expansion of the ventricles in contrast to the HV group (post hoc test (Bonferroni) P < 0.001). Diffusion-weighted imaging revealed significant differences in the right frontal lobe and the left occipital lobe between the TR-PTSD and HV group (post hoc test (Bonferroni) P < 0.001). Moderate hypometabolism was noted in the occipital lobe in 6 of the 9 patients with TR-PTSD, in the temporal lobe in 1 of the 9 patients, and in the caudate nucleus in 5 of the 9 patients. In 2 cases, additional hypometabolism was observed in the posterior cingulate cortex and in the parietal and frontal lobes. The findings from this study show that TR-PTSD might have a deleterious influence on a set of specific brain structures. This study also demonstrated that PET combined with MRI is sensitive in detecting possible metabolic and structural brain changes in TR-PTSD.

DEPDC5 mutations are not a frequent cause of familial temporal lobe epilepsy.

PubMed

Striano, Pasquale; Serioli, Elena; Santulli, Lia; Manna, Ida; Labate, Angelo; Dazzo, Emanuela; Pasini, Elena; Gambardella, Antonio; Michelucci, Roberto; Striano, Salvatore; Nobile, Carlo

2015-10-01

Mutations in the DEPDC5 (DEP domain-containing protein 5) gene are a major cause of familial focal epilepsy with variable foci (FFEVF) and are predicted to account for 12-37% of families with inherited focal epilepsies. To assess the clinical impact of DEPDC5 mutations in familial temporal lobe epilepsy, we screened a collection of Italian families with either autosomal dominant lateral temporal epilepsy (ADLTE) or familial mesial temporal lobe epilepsy (FMTLE). The probands of 28 families classified as ADLTE and 17 families as FMTLE were screened for DEPDC5 mutations by whole exome or targeted massive parallel sequencing. Putative mutations were validated by Sanger sequencing. We identified a DEPDC5 nonsense mutation (c.918C>G; p.Tyr306*) in a family with two affected members, clinically classified as FMTLE. The proband had temporal lobe seizures with prominent psychic symptoms (déjà vu, derealization, and forced thoughts); her mother had temporal lobe seizures, mainly featuring visceral epigastric auras and anxiety. In total, we found a single DEPDC5 mutation in one of (2.2%) 45 families with genetic temporal lobe epilepsy, a proportion much lower than that reported in other inherited focal epilepsies. © 2015 The Authors. Epilepsia published by Wiley Periodicals Inc. on behalf of International League Against Epilepsy.

Transcriptional profiles of supragranular-enriched genes associate with corticocortical network architecture in the human brain

PubMed Central

Krienen, Fenna M.; Yeo, B. T. Thomas; Ge, Tian; Buckner, Randy L.; Sherwood, Chet C.

2016-01-01

The human brain is patterned with disproportionately large, distributed cerebral networks that connect multiple association zones in the frontal, temporal, and parietal lobes. The expansion of the cortical surface, along with the emergence of long-range connectivity networks, may be reflected in changes to the underlying molecular architecture. Using the Allen Institute’s human brain transcriptional atlas, we demonstrate that genes particularly enriched in supragranular layers of the human cerebral cortex relative to mouse distinguish major cortical classes. The topography of transcriptional expression reflects large-scale brain network organization consistent with estimates from functional connectivity MRI and anatomical tracing in nonhuman primates. Microarray expression data for genes preferentially expressed in human upper layers (II/III), but enriched only in lower layers (V/VI) of mouse, were cross-correlated to identify molecular profiles across the cerebral cortex of postmortem human brains (n = 6). Unimodal sensory and motor zones have similar molecular profiles, despite being distributed across the cortical mantle. Sensory/motor profiles were anticorrelated with paralimbic and certain distributed association network profiles. Tests of alternative gene sets did not consistently distinguish sensory and motor regions from paralimbic and association regions: (i) genes enriched in supragranular layers in both humans and mice, (ii) genes cortically enriched in humans relative to nonhuman primates, (iii) genes related to connectivity in rodents, (iv) genes associated with human and mouse connectivity, and (v) 1,454 gene sets curated from known gene ontologies. Molecular innovations of upper cortical layers may be an important component in the evolution of long-range corticocortical projections. PMID:26739559

Transcriptional profiles of supragranular-enriched genes associate with corticocortical network architecture in the human brain.

PubMed

Krienen, Fenna M; Yeo, B T Thomas; Ge, Tian; Buckner, Randy L; Sherwood, Chet C

2016-01-26

The human brain is patterned with disproportionately large, distributed cerebral networks that connect multiple association zones in the frontal, temporal, and parietal lobes. The expansion of the cortical surface, along with the emergence of long-range connectivity networks, may be reflected in changes to the underlying molecular architecture. Using the Allen Institute's human brain transcriptional atlas, we demonstrate that genes particularly enriched in supragranular layers of the human cerebral cortex relative to mouse distinguish major cortical classes. The topography of transcriptional expression reflects large-scale brain network organization consistent with estimates from functional connectivity MRI and anatomical tracing in nonhuman primates. Microarray expression data for genes preferentially expressed in human upper layers (II/III), but enriched only in lower layers (V/VI) of mouse, were cross-correlated to identify molecular profiles across the cerebral cortex of postmortem human brains (n = 6). Unimodal sensory and motor zones have similar molecular profiles, despite being distributed across the cortical mantle. Sensory/motor profiles were anticorrelated with paralimbic and certain distributed association network profiles. Tests of alternative gene sets did not consistently distinguish sensory and motor regions from paralimbic and association regions: (i) genes enriched in supragranular layers in both humans and mice, (ii) genes cortically enriched in humans relative to nonhuman primates, (iii) genes related to connectivity in rodents, (iv) genes associated with human and mouse connectivity, and (v) 1,454 gene sets curated from known gene ontologies. Molecular innovations of upper cortical layers may be an important component in the evolution of long-range corticocortical projections.

Frontal lobe function in elderly patients with Alzheimer's disease and caregiver burden.

PubMed

Hashimoto, Akiko; Matsuoka, Kiwamu; Yasuno, Fumihiko; Takahashi, Masato; Iida, Junzo; Jikumaru, Kiyoko; Kishimoto, Toshifumi

2017-07-01

Understanding of the relationship between caregiver burden and the degree of behavioural deficits in patients with Alzheimer's disease (AD) is relatively limited. Therefore, it is worthwhile to examine the correlations between the various relevant factors to improve the efficacy of care for patients with AD. The aim of this study was to investigate the specific contributions of frontal lobe dysfunction in AD patients to caregiver burden, while controlling for other predictor variables. Participants included 30 pairs of caregivers and patients with AD. The Zarit Burden Interview and Frontal Assessment Battery were used to measure the caregiver burden and patients' frontal lobe function, respectively. To investigate the effects of frontal lobe dysfunction on caregiver burden, hierarchical regression equations with steps incorporating additional predictor variables were fitted. We also performed a correlation analysis between the individual subdomains of the Zarit Burden Interview and the predictor variables. Our study suggests that the degree of frontal lobe dysfunction in AD patients predicts their caregiver burden, when other factors of daily functional limitations and neuropsychiatric symptoms are controlled. Daily functional limitations and neuropsychiatric symptoms affected caregivers' psychosocial burden, whereas frontal lobe dysfunction affected caregivers' burden due to the increase in the dependency of the patients. Our findings indicate that to ameliorate the disabilities of patients and reduce caregiver burden, there is a need for interventions that focus on psychosocial burdens, as shown in previous studies, as well as on excessive dependency due to frontal lobe dysfunction. © 2017 Japanese Psychogeriatric Society.

Structures of Ca(V) Ca**2+/CaM-IQ Domain Complexes Reveal Binding Modes That Underlie Calcium-Dependent Inactivation And Facilitation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, E.Y.; Rumpf, C.H.; Fujiwara, Y.

2009-05-20

Calcium influx drives two opposing voltage-activated calcium channel (Ca{sub V}) self-modulatory processes: calcium-dependent inactivation (CDI) and calcium-dependent facilitation (CDF). Specific Ca{sup 2+}/calmodulin (Ca{sup 2+}/CaM) lobes produce CDI and CDF through interactions with the Ca{sub V}{alpha}{sub 1} subunit IQ domain. Curiously, Ca{sup 2+}/CaM lobe modulation polarity appears inverted between Ca{sub V}1s and Ca{sub V}2s. Here, we present crystal structures of Ca{sub V}2.1, Ca{sub V}2.2, and Ca{sub V}2.3 Ca{sup 2+}/CaM-IQ domain complexes. All display binding orientations opposite to Ca{sub V}1.2 with a physical reversal of the CaM lobe positions relative to the IQ {alpha}-helix. Titration calorimetry reveals lobe competition for a high-affinitymore » site common to Ca{sub V}1 and Ca{sub V}2 IQ domains that is occupied by the CDI lobe in the structures. Electrophysiological experiments demonstrate that the N-terminal Ca{sub V}2 Ca{sup 2+}/C-lobe anchors affect CDF. Together, the data unveil the remarkable structural plasticity at the heart of Ca{sub V} feedback modulation and indicate that Ca{sub V}1 and Ca{sub V}2 IQ domains bear a dedicated CDF site that exchanges Ca{sup 2+}/CaM lobe occupants.« less

Frontal versus dysexecutive syndromes: relevance of an interactionist approach in a case series of patients with prefrontal lobe damage.

PubMed

Besnard, Jérémy; Allain, Philippe; Lerma, Vanesa; Aubin, Ghislaine; Chauviré, Valérie; Etcharry-Bouyx, Frédérique; Le Gall, Didier

2016-07-19

The concepts of "frontal" and "dysexecutive" syndromes are still a matter of debate in the literature. These terms are often used interchangeably but can be distinguished when considering specific frontal behavioural deficits which occur during social interaction. Despite being of interest for the clinical assessment and care management of patients with anterior brain damage, few studies have tried to disentangle the specificity of each syndrome. We report the case of eight patients with frontal lobe damage who were assigned to one of two groups based on whether or not they showed a dysexecutive syndrome. The nondysexecutive group differed from the dysexecutive group in showing environmental dependency phenomena, behavioural disorders triggered by social interaction. By adopting an interactionist perspective, this pilot study contributes to defining more precisely the distinction between "frontal" and "dysexecutive" syndromes. The discussion focuses on the potential interest of the interactionist approach in designing appropriate methodologies of assessment and rehabilitation of patients with frontal lobe syndrome.

Dissociating the semantic function of two neighbouring subregions in the left lateral anterior temporal lobe

PubMed Central

Sanjuán, Ana; Hope, Thomas M.H.; Parker Jones, 'Ōiwi; Prejawa, Susan; Oberhuber, Marion; Guerin, Julie; Seghier, Mohamed L.; Green, David W.; Price, Cathy J.

2015-01-01

We used fMRI in 35 healthy participants to investigate how two neighbouring subregions in the lateral anterior temporal lobe (LATL) contribute to semantic matching and object naming. Four different levels of processing were considered: (A) recognition of the object concepts; (B) search for semantic associations related to object stimuli; (C) retrieval of semantic concepts of interest; and (D) retrieval of stimulus specific concepts as required for naming. During semantic association matching on picture stimuli or heard object names, we found that activation in both subregions was higher when the objects were semantically related (mug–kettle) than unrelated (car–teapot). This is consistent with both LATL subregions playing a role in (C), the successful retrieval of amodal semantic concepts. In addition, one subregion was more activated for object naming than matching semantically related objects, consistent with (D), the retrieval of a specific concept for naming. We discuss the implications of these novel findings for cognitive models of semantic processing and left anterior temporal lobe function. PMID:25496810

The inferior, anterior temporal lobes and semantic memory clarified: novel evidence from distortion-corrected fMRI.

PubMed

Visser, M; Embleton, K V; Jefferies, E; Parker, G J; Ralph, M A Lambon

2010-05-01

The neural basis of semantic memory generates considerable debate. Semantic dementia results from bilateral anterior temporal lobe (ATL) atrophy and gives rise to a highly specific impairment of semantic memory, suggesting that this region is a critical neural substrate for semantic processing. Recent rTMS experiments with neurologically-intact participants also indicate that the ATL are a necessary substrate for semantic memory. Exactly which regions within the ATL are important for semantic memory are difficult to detect from these methods (because the damage in SD covers a large part of the ATL). Functional neuroimaging might provide important clues about which specific areas exhibit activation that correlates with normal semantic performance. Neuroimaging studies, however, have not consistently found anterior temporal lobe activation in semantic tasks. A recent meta-analysis indicates that this inconsistency may be due to a collection of technical limitations associated with previous studies, including a reduced field-of-view and magnetic susceptibility artefacts associated with standard gradient echo fMRI. We conducted an fMRI study of semantic memory using a combination of techniques which improve sensitivity to ATL activations whilst preserving whole-brain coverage. As expected from SD patients and ATL rTMS experiments, this method revealed bilateral temporal activation extending from the inferior temporal lobe along the fusiform gyrus to the anterior temporal regions, bilaterally. We suggest that the inferior, anterior temporal lobe region makes a crucial contribution to semantic cognition and utilising this version of fMRI will enable further research on the semantic role of the ATL. 2010 Elsevier Ltd. All rights reserved.

Region-specific reduction in brain volume in young adults with perinatal hypoxic-ischaemic encephalopathy.

PubMed

Bregant, Tina; Rados, Milan; Vasung, Lana; Derganc, Metka; Evans, Alan C; Neubauer, David; Kostovic, Ivica

2013-11-01

A severe form of perinatal hypoxic-ischaemic encephalopathy (HIE) carries a high risk of perinatal death and severe neurological sequelae while in mild HIE only discrete cognitive disorders may occur. To compare total brain volumes and region-specific cortical measurements between young adults with mild-moderate perinatal HIE and a healthy control group of the same age. MR imaging was performed in a cohort of 14 young adults (9 males, 5 females) with a history of mild or moderate perinatal HIE. The control group consisted of healthy participants, matched with HIE group by age and gender. Volumetric analysis was done after the processing of MR images using a fully automated CIVET pipeline. We measured gyrification indexes, total brain volume, volume of grey and white matter, and of cerebrospinal fluid. We also measured volume, thickness and area of the cerebral cortex in the parietal, occipital, frontal, and temporal lobe, and of the isthmus cinguli, parahippocampal and cingulated gyrus, and insula. The HIE patient group showed smaller absolute volumetric data. Statistically significant (p < 0.05) reductions of gyrification index in the right hemisphere, of cortical areas in the right temporal lobe and parahippocampal gyrus, of cortical volumes in the right temporal lobe and of cortical thickness in the right isthmus of the cingulate gyrus were found. Comparison between the healthy group and the HIE group of the same gender showed statistically significant changes in the male HIE patients, where a significant reduction was found in whole brain volume; left parietal, bilateral temporal, and right parahippocampal gyrus cortical areas; and bilateral temporal lobe cortical volume. Our analysis of total brain volumes and region-specific corticometric parameters suggests that mild-moderate forms of perinatal HIE lead to reductions in whole brain volumes. In the study reductions were most pronounced in temporal lobe and parahippocampal gyrus. Copyright © 2013 European Paediatric Neurology Society. All rights reserved.

Mechanisms of oocyte development in European sea bass (Dicentrarchus labrax L.): investigations via application of unilateral ovariectomy.

PubMed

García-López, Ángel; Sánchez-Amaya, María I; Tyler, Charles R; Prat, Francisco

2011-08-01

Unilateral ovariectomy (ULO) was performed in European sea bass (Dicentrarchus labrax L.) during late pre-vitellogenesis/early vitellogenesis. Plasma steroid levels and the expression of a suite of potential oogenesis-relevant genes in the ovary, brain, and pituitary were evaluated with the aim of understanding their involvement in the compensatory oocyte development occurring within the remaining ovarian lobe. After 69 days of surgery the remaining ovarian lobe in ULO fish was gravimetrically equivalent to an intact-paired ovary of sham operated, control fish. This compensatory ovarian growth was based on an increased number of early perinucleolar oocytes and mid-late stage vitellogenic follicles without an apparent recruitment of primary oocytes into the secondary growth phase. Plasma steroid levels were similar in ULO and control females at all time points analyzed, suggesting an increased steroid production of the remaining ovarian lobe in hemi-castrated females. Results of the gene expression survey conducted indicate that the signaling pathways mediated by Fsh and Gnrh1 constitute the central axes orchestrating the observed ovarian compensatory growth. In addition, steroid receptors, Star protein, Igfs, and members of the transforming growth factor beta superfamily including anti-Mullerian hormone and bone morphogenetic protein 4 were identified as potentially relevant players within this process, although their specific actions and interactions remain to be established. Our results demonstrate that ULO provides an excellent in vivo model for elucidating the interconnected endocrine and molecular mechanisms controlling oocyte development in European sea bass.

Localized Ablation of Thyroid Tissue by High-Intensity Focused Ultrasound: an Alternative to Surgery?

NASA Astrophysics Data System (ADS)

Esnault, Olivier; Franc, Brigitte; Chapelon, Jean-Yves; Lacoste, Francois

2006-05-01

PURPOSE: The aim of this study was to evaluate the feasibility of using a High-intensity focused ultrasound (HIFU) device to obtain a localised destruction of the thyroid with no damage to adjacent tissues. MATERIALS AND METHODS: The ewe model was used because its thyroid gland is easily accessible with ultrasound. The animals were anaesthetised with 10 mg / kg IV injection of Penthothal. The HIFU pulses were generated by a 3-MHz spherical transducer under ultrasound guidance. Macroscopic and microscopic tissue lesions were identified after formalin fixation of the anterior part of the ewe's neck. RESULTS: After determining the optimal instrument settings to obtain localized thyroid ablation, the repeatability of the method was evaluated using a HIFU prototype designed specifically for human use: in 13 ewes (26 treated lobes), an average of 20 (range: 14-27) ultrasound pulses (pulse duration: 3 s) per lobe covering a mean volume of 0.5 cm3 (range: 0.3-0.7 cm3) were delivered. The ewes were sacrificed 2-5 weeks after treatment delivery. No damage to the nerves, trachea, esophagus or muscle was observed. Only 3 ewes suffered superficial skin burns. The desired thyroid lesions were obtained in 25/26 treated lobes, as demonstrated by fibrotic tissues, which replaced necrotic areas. CONCLUSION: These results obtained in the ewe model show that thyroid lesions of defined volume can be induced safely and suggest that the HIFU device is now ready for human trials.

Subregional neuroanatomical change as a biomarker for Alzheimer's disease

PubMed Central

Holland, Dominic; Brewer, James B.; Hagler, Donald J.; Fennema-Notestine, Christine; Dale, Anders M.; Weiner, Michael; Thal, Leon; Petersen, Ronald; Jack, Clifford R.; Jagust, William; Trojanowki, John; Toga, Arthur W.; Beckett, Laurel; Green, Robert C.; Gamst, Anthony; Potter, William Z.; Montine, Tom; Anders, Dale; Bernstein, Matthew; Felmlee, Joel; Fox, Nick; Thompson, Paul; Schuff, Norbert; Alexander, Gene; Bandy, Dan; Koeppe, Robert A.; Foster, Norm; Reiman, Eric M.; Chen, Kewei; Shaw, Les; Lee, Virginia M.-Y.; Korecka, Magdalena; Crawford, Karen; Neu, Scott; Harvey, Danielle; Kornak, John; Kachaturian, Zaven; Frank, Richard; Snyder, Peter J.; Molchan, Susan; Kaye, Jeffrey; Vorobik, Remi; Quinn, Joseph; Schneider, Lon; Pawluczyk, Sonia; Spann, Bryan; Fleisher, Adam S.; Vanderswag, Helen; Heidebrink, Judith L.; Lord, Joanne L.; Johnson, Kris; Doody, Rachelle S.; Villanueva-Meyer, Javier; Chowdhury, Munir; Stern, Yaakov; Honig, Lawrence S.; Bell, Karen L.; Morris, John C.; Mintun, Mark A.; Schneider, Stacy; Marson, Daniel; Griffith, Randall; Badger, Beverly; Grossman, Hillel; Tang, Cheuk; Stern, Jessica; deToledo-Morrell, Leyla; Shah, Raj C.; Bach, Julie; Duara, Ranjan; Isaacson, Richard; Strauman, Silvia; Albert, Marilyn S.; Pedroso, Julia; Toroney, Jaimie; Rusinek, Henry; de Leon, Mony J.; De Santi, Susan M.; Doraiswamy, P. Murali; Petrella, Jeffrey R.; Aiello, Marilyn; Clark, Christopher M.; Pham, Cassie; Nunez, Jessica; Smith, Charles D.; Given, Curtis A.; Hardy, Peter; DeKosky, Steven T.; Oakley, MaryAnn; Simpson, Donna M.; Ismail, M. Saleem; Porsteinsson, Anton; McCallum, Colleen; Cramer, Steven C.; Mulnard, Ruth A.; McAdams-Ortiz, Catherine; Diaz-Arrastia, Ramon; Martin-Cook, Kristen; DeVous, Michael; Levey, Allan I.; Lah, James J.; Cellar, Janet S.; Burns, Jeffrey M.; Anderson, Heather S.; Laubinger, Mary M.; Bartzokis, George; Silverman, Daniel H. S.; Lu, Po H.; Fletcher, Rita; Parfitt, Francine; Johnson, Heather; Farlow, Martin; Herring, Scott; Hake, Ann M.; van Dyck, Christopher H.; MacAvoy, Martha G.; Bifano, Laurel A.; Chertkow, Howard; Bergman, Howard; Hosein, Chris; Black, Sandra; Graham, Simon; Caldwell, Curtis; Feldman, Howard; Assaly, Michele; Hsiung, Ging-Yuek R.; Kertesz, Andrew; Rogers, John; Trost, Dick; Bernick, Charles; Gitelman, Darren; Johnson, Nancy; Mesulam, Marsel; Sadowsky, Carl; Villena, Teresa; Mesner, Scott; Aisen, Paul S.; Johnson, Kathleen B.; Behan, Kelly E.; Sperling, Reisa A.; Rentz, Dorene M.; Johnson, Keith A.; Rosen, Allyson; Tinklenberg, Jared; Ashford, Wes; Sabbagh, Marwan; Connor, Donald; Obradov, Sanja; Killiany, Ron; Norbash, Alex; Obisesan, Thomas O.; Jayam-Trouth, Annapurni; Wang, Paul; Auchus, Alexander P.; Huang, Juebin; Friedland, Robert P.; DeCarli, Charles; Fletcher, Evan; Carmichael, Owen; Kittur, Smita; Mirje, Seema; Johnson, Sterling C.; Borrie, Michael; Lee, T.-Y.; Asthana, Sanjay; Carlsson, Cynthia M.; Potkin, Steven G.; Highum, Diane; Preda, Adrian; Nguyen, Dana; Tariot, Pierre N.; Hendin, Barry A.; Scharre, Douglas W.; Kataki, Maria; Beversdorf, David Q.; Zimmerman, Earl A.; Celmins, Dzintra; Brown, Alice D.; Gandy, Sam; Marenberg, Marjorie E.; Rovner, Barry W.; Pearlson, Godfrey; Blank, Karen; Anderson, Karen; Saykin, Andrew J.; Santulli, Robert B.; Pare, Nadia; Williamson, Jeff D.; Sink, Kaycee M.; Potter, Huntington; Ashok Raj, B.; Giordano, Amy; Ott, Brian R.; Wu, Chuang-Kuo; Cohen, Ronald; Wilks, Kerri L.; Safirstein, Beth E.

2009-01-01

Regions of the temporal and parietal lobes are particularly damaged in Alzheimer's disease (AD), and this leads to a predictable pattern of brain atrophy. In vivo quantification of subregional atrophy, such as changes in cortical thickness or structure volume, could lead to improved diagnosis and better assessment of the neuroprotective effects of a therapy. Toward this end, we have developed a fast and robust method for accurately quantifying cerebral structural changes in several cortical and subcortical regions using serial MRI scans. In 169 healthy controls, 299 subjects with mild cognitive impairment (MCI), and 129 subjects with AD, we measured rates of subregional cerebral volume change for each cohort and performed power calculations to identify regions that would provide the most sensitive outcome measures in clinical trials of disease-modifying agents. Consistent with regional specificity of AD, temporal-lobe cortical regions showed the greatest disease-related changes and significantly outperformed any of the clinical or cognitive measures examined for both AD and MCI. Global measures of change in brain structure, including whole-brain and ventricular volumes, were also elevated in AD and MCI, but were less salient when compared to changes in normal subjects. Therefore, these biomarkers are less powerful for quantifying disease-modifying effects of compounds that target AD pathology. The findings indicate that regional temporal lobe cortical changes would have great utility as outcome measures in clinical trials and may also have utility in clinical practice for aiding early diagnosis of neurodegenerative disease. PMID:19996185

Perfusion deficits and functional connectivity alterations in patients with post-traumatic stress disorder

NASA Astrophysics Data System (ADS)

Liu, Yang; Li, Baojuan; Zhang, Xi; Zhang, Linchuan; Li, Liang; Lu, Hongbing

2016-03-01

To explore the alteration in cerebral blood flow (CBF) and functional connectivity between survivors with recent onset post-traumatic stress disorder (PTSD) and without PTSD, survived from the same coal mine flood disaster. In this study, a processing pipeline using arterial spin labeling (ASL) sequence was proposed. Considering low spatial resolution of ASL sequence, a linear regression method was firstly used to correct the partial volume (PV) effect for better CBF estimation. Then the alterations of CBF between two groups were analyzed using both uncorrected and PV-corrected CBF maps. Based on altered CBF regions detected from the CBF analysis as seed regions, the functional connectivity abnormities in PTSD patients was investigated. The CBF analysis using PV-corrected maps indicates CBF deficits in the bilateral frontal lobe, right superior frontal gyrus and right corpus callosum of PTSD patients, while only right corpus callosum was identified in uncorrected CBF analysis. Furthermore, the regional CBF of the right superior frontal gyrus exhibits significantly negative correlation with the symptom severity in PTSD patients. The resting-state functional connectivity indicates increased connectivity between left frontal lobe and right parietal lobe. These results indicate that PV-corrected CBF exhibits more subtle perfusion changes and may benefit further perfusion and connectivity analysis. The symptom-specific perfusion deficits and aberrant connectivity in above memory-related regions may be putative biomarkers for recent onset PTSD induced by a single prolonged trauma exposure and help predict the severity of PTSD.

Subregional neuroanatomical change as a biomarker for Alzheimer's disease.

PubMed

Holland, Dominic; Brewer, James B; Hagler, Donald J; Fennema-Notestine, Christine; Fenema-Notestine, Christine; Dale, Anders M

2009-12-08

Regions of the temporal and parietal lobes are particularly damaged in Alzheimer's disease (AD), and this leads to a predictable pattern of brain atrophy. In vivo quantification of subregional atrophy, such as changes in cortical thickness or structure volume, could lead to improved diagnosis and better assessment of the neuroprotective effects of a therapy. Toward this end, we have developed a fast and robust method for accurately quantifying cerebral structural changes in several cortical and subcortical regions using serial MRI scans. In 169 healthy controls, 299 subjects with mild cognitive impairment (MCI), and 129 subjects with AD, we measured rates of subregional cerebral volume change for each cohort and performed power calculations to identify regions that would provide the most sensitive outcome measures in clinical trials of disease-modifying agents. Consistent with regional specificity of AD, temporal-lobe cortical regions showed the greatest disease-related changes and significantly outperformed any of the clinical or cognitive measures examined for both AD and MCI. Global measures of change in brain structure, including whole-brain and ventricular volumes, were also elevated in AD and MCI, but were less salient when compared to changes in normal subjects. Therefore, these biomarkers are less powerful for quantifying disease-modifying effects of compounds that target AD pathology. The findings indicate that regional temporal lobe cortical changes would have great utility as outcome measures in clinical trials and may also have utility in clinical practice for aiding early diagnosis of neurodegenerative disease.

Validation of diagnostic tests for depressive disorder in drug-resistant mesial temporal lobe epilepsy.

PubMed

de Lemos Zingano, Bianca; Guarnieri, Ricardo; Diaz, Alexandre Paim; Schwarzbold, Marcelo Liborio; Bicalho, Maria Alice Horta; Claudino, Lucia Sukys; Markowitsch, Hans J; Wolf, Peter; Lin, Katia; Walz, Roger

2015-09-01

This study aimed to evaluate the diagnostic accuracy of the Hamilton Rating Scale for Depression (HRSD), the Beck Depression Inventory (BDI), the Hospital Anxiety and Depression Scale (HADS), and the Hospital Anxiety and Depression Scale-Depression subscale (HADS-D) as diagnostic tests for depressive disorder in drug-resistant mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS). One hundred three patients with drug-resistant MTLE-HS were enrolled. All patients underwent a neurological examination, interictal and ictal video-electroencephalogram (V-EEG) analyses, and magnetic resonance imaging (MRI). Psychiatric interviews were based on DSM-IV-TR criteria and ILAE Commission of Psychobiology classification as a gold standard; HRSD, BDI, HADS, and HADS-D were used as psychometric diagnostic tests, and receiver operating characteristic (ROC) curves were used to determine the optimal threshold scores. For all the scales, the areas under the curve (AUCs) were approximately 0.8, and they were able to identify depression in this sample. A threshold of ≥9 on the HRSD and a threshold of ≥8 on the HADS-D showed a sensitivity of 70% and specificity of 80%. A threshold of ≥19 on the BDI and HADS-D total showed a sensitivity of 55% and a specificity of approximately 90%. The instruments showed a negative predictive value of approximately 87% and a positive predictive value of approximately 65% for the BDI and HADS total and approximately 60% for the HRSD and HADS-D. HRSD≥9 and HADS-D≥8 had the best balance between sensitivity (approximately 70%) and specificity (approximately 80%). However, with these thresholds, these diagnostic tests do not appear useful in identifying depressive disorder in this population with epilepsy, and their specificity (approximately 80%) and PPV (approximately 55%) were lower than those of the other scales. We believe that the BDI and HADS total are valid diagnostic tests for depressive disorder in patients with MTLE-HS, as both scales showed acceptable (though not high) specificity and PPV for this type of study. Copyright © 2015 Elsevier Inc. All rights reserved.

Evolution reversed: the ability to bind iron restored to the N-lobe of the murine inhibitor of carbonic anhydrase by strategic mutagenesis.

PubMed

Mason, Anne B; Judson, Gregory L; Bravo, Maria Cristina; Edelstein, Andrew; Byrne, Shaina L; James, Nicholas G; Roush, Eric D; Fierke, Carol A; Bobst, Cedric E; Kaltashov, Igor A; Daughtery, Margaret A

2008-09-16

The murine inhibitor of carbonic anhydrase (mICA) is a member of the superfamily related to the bilobal iron transport protein transferrin (TF), which binds a ferric ion within a cleft in each lobe. Although the gene encoding ICA in humans is classified as a pseudogene, an apparently functional ICA gene has been annotated in mice, rats, cows, pigs, and dogs. All ICAs lack one (or more) of the amino acid ligands in each lobe essential for high-affinity coordination of iron and the requisite synergistic anion, carbonate. The reason why ICA family members have lost the ability to bind iron is potentially related to acquiring a new function(s), one of which is inhibition of certain carbonic anhydrase (CA) isoforms. A recombinant mutant of the mICA (W124R/S188Y) was created with the goal of restoring the ligands required for both anion (Arg124) and iron (Tyr188) binding in the N-lobe. Absorption and fluorescence spectra definitively show that the mutant binds ferric iron in the N-lobe. Electrospray ionization mass spectrometry confirms the presence of both ferric iron and carbonate. At the putative endosomal pH of 5.6, iron is released by two slow processes indicative of high-affinity coordination. Induction of specific iron binding implies that (1) the structure of mICA resembles those of other TF family members and (2) the N-lobe can adopt a conformation in which the cleft closes when iron binds. Because the conformational change in the N-lobe indicated by metal binding does not impact the inhibitory activity of mICA, inhibition of CA was tentatively assigned to the C-lobe. Proof of this assignment is provided by limited trypsin proteolysis of porcine ICA.

Searching for Tomorrow's Innovators: Profiling Creative Adolescents

ERIC Educational Resources Information Center

Kerr, Barbara; McKay, Robyn

2013-01-01

Profiling may be a viable means of identifying those creative adolescents who can benefit from specialized guidance and exploration of science, technology, engineering, and mathematics (STEM) fields, arts, and human services. The experimenters developed 1 general and 5 specific profiles including interest, personality, and achievement variables…

Normalization for sparse encoding of odors by a wide-field interneuron.

PubMed

Papadopoulou, Maria; Cassenaer, Stijn; Nowotny, Thomas; Laurent, Gilles

2011-05-06

Sparse coding presents practical advantages for sensory representations and memory storage. In the insect olfactory system, the representation of general odors is dense in the antennal lobes but sparse in the mushroom bodies, only one synapse downstream. In locusts, this transformation relies on the oscillatory structure of antennal lobe output, feed-forward inhibitory circuits, intrinsic properties of mushroom body neurons, and connectivity between antennal lobe and mushroom bodies. Here we show the existence of a normalizing negative-feedback loop within the mushroom body to maintain sparse output over a wide range of input conditions. This loop consists of an identifiable "giant" nonspiking inhibitory interneuron with ubiquitous connectivity and graded release properties.

The neural correlates of specific versus general autobiographical memory construction and elaboration

PubMed Central

Holland, Alisha C.; Addis, Donna Rose; Kensinger, Elizabeth A.

2011-01-01

We examined the neural correlates of specific (i.e., unique to time and place) and general (i.e., extended in or repeated over time) autobiographical memories (AMs) during their initial construction and later elaboration phases. The construction and elaboration of specific and general events engaged a widely distributed set of regions previously associated with AM recall. Specific (vs. general) event construction preferentially engaged prefrontal and medial temporal lobe regions known to be critical for memory search and retrieval processes. General event elaboration was differentiated from specific event elaboration by extensive right-lateralized prefrontal cortex (PFC) activity. Interaction analyses confirmed that PFC activity was disproportionately engaged by specific AMs during construction, and general AMs during elaboration; a similar pattern was evident in regions of the left lateral temporal lobe. These neural differences between specific and general AM construction and elaboration were largely unrelated to reported differences in the level of detail recalled about each type of event. PMID:21803063

Thalamotemporal impairment in temporal lobe epilepsy: a combined MRI analysis of structure, integrity, and connectivity.

PubMed

Keller, Simon S; O'Muircheartaigh, Jonathan; Traynor, Catherine; Towgood, Karren; Barker, Gareth J; Richardson, Mark P

2014-02-01

Thalamic abnormality in temporal lobe epilepsy (TLE) is well known from imaging studies, but evidence is lacking regarding connectivity profiles of the thalamus and their involvement in the disease process. We used a novel multisequence magnetic resonance imaging (MRI) protocol to elucidate the relationship between mesial temporal and thalamic pathology in TLE. For 23 patients with TLE and 23 healthy controls, we performed T1 -weighted (for analysis of tissue structure), diffusion tensor imaging (tissue connectivity), and T1 and T2 relaxation (tissue integrity) MRI across the whole brain. We used connectivity-based segmentation to determine connectivity patterns of thalamus to ipsilateral cortical regions (occipital, parietal, prefrontal, postcentral, precentral, and temporal). We subsequently determined volumes, mean tractography streamlines, and mean T1 and T2 relaxometry values for each thalamic segment preferentially connecting to a given cortical region, and of the hippocampus and entorhinal cortex. As expected, patients had significant volume reduction and increased T2 relaxation time in ipsilateral hippocampus and entorhinal cortex. There was bilateral volume loss, mean streamline reduction, and T2 increase of the thalamic segment preferentially connected to temporal lobe, corresponding to anterior, dorsomedial, and pulvinar thalamic regions, with no evidence of significant change in any other thalamic segments. Left and right thalamotemporal segment volume and T2 were significantly correlated with volume and T2 of ipsilateral (epileptogenic), but not contralateral (nonepileptogenic), mesial temporal structures. These convergent and robust data indicate that thalamic abnormality in TLE is restricted to the area of the thalamus that is preferentially connected to the epileptogenic temporal lobe. The degree of thalamic pathology is related to the extent of mesial temporal lobe damage in TLE. © 2014 The Authors. Epilepsia published by Wiley Periodicals, Inc. on behalf of International League Against Epilepsy.

Integrated analysis of rice transcriptomic and metabolomic responses to elevated night temperatures identifies sensitivity- and tolerance-related profiles.

PubMed

Glaubitz, Ulrike; Li, Xia; Schaedel, Sandra; Erban, Alexander; Sulpice, Ronan; Kopka, Joachim; Hincha, Dirk K; Zuther, Ellen

2017-01-01

Transcript and metabolite profiling were performed on leaves from six rice cultivars under high night temperature (HNT) condition. Six genes were identified as central for HNT response encoding proteins involved in transcription regulation, signal transduction, protein-protein interactions, jasmonate response and the biosynthesis of secondary metabolites. Sensitive cultivars showed specific changes in transcript abundance including abiotic stress responses, changes of cell wall-related genes, of ABA signaling and secondary metabolism. Additionally, metabolite profiles revealed a highly activated TCA cycle under HNT and concomitantly increased levels in pathways branching off that could be corroborated by enzyme activity measurements. Integrated data analysis using clustering based on one-dimensional self-organizing maps identified two profiles highly correlated with HNT sensitivity. The sensitivity profile included genes of the functional bins abiotic stress, hormone metabolism, cell wall, signaling, redox state, transcription factors, secondary metabolites and defence genes. In the tolerance profile, similar bins were affected with slight differences in hormone metabolism and transcription factor responses. Metabolites of the two profiles revealed involvement of GABA signaling, thus providing a link to the TCA cycle status in sensitive cultivars and of myo-inositol as precursor for inositol phosphates linking jasmonate signaling to the HNT response specifically in tolerant cultivars. © 2016 John Wiley & Sons Ltd.

Quantification of incidental mediastinal and hilar irradiation delivered during definitive stereotactic body radiation therapy for peripheral non-small cell lung cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Martin, Kate L.; Gomez, Jorge; Nazareth, Daryl P.

2012-07-01

To determine the amount of incidental radiation dose received by the mediastinal and hilar nodes for patients with non-small cell lung cancer (NSCLC) treated with stereotactic body radiation therapy (SBRT). Fifty consecutive patients with NSCLC, treated using an SBRT technique, were identified. Of these patients, 38 had a prescription dose of 60 Gy in 20-Gy fractions and were eligible for analysis. For each patient, ipsilateral upper (level 2) and lower (level 4) paratracheal, and hilar (level 10) nodal regions were contoured on the planning computed tomography (CT) images. Using the clinical treatment plan, dose and volume calculations were performed retrospectivelymore » for each nodal region. SBRT to upper lobe tumors resulted in an average total ipsilateral mean dose of between 5.2 and 7.8 Gy for the most proximal paratracheal nodal stations (2R and 4R for right upper lobe lesions, 2L and 4L for left upper lobe lesions). SBRT to lower lobe tumors resulted in an average total ipsilateral mean dose of between 15.6 and 21.5 Gy for the most proximal hilar nodal stations (10R for right lower lobe lesions, 10 l for left lower lobe lesions). Doses to more distal nodes were substantially lower than 5 Gy. The often substantial incidental irradiation, delivered during SBRT for peripheral NSCLC of the lower lobes to the most proximal hilar lymph nodes may be therapeutic for low-volume, subclinical nodal disease. Treatment of peripheral upper lobe lung tumors delivers less incidental irradiation to the paratracheal lymph nodes with lower likelihood of therapeutic benefit.« less

Structure and Function of the Superior Temporal Plane in Adult Males with Cleft Lip and Palate: Pathologic Enlargement with No Relationship to Childhood Hearing Deficits

ERIC Educational Resources Information Center

Shriver, A. S.; Canady, J.; Richman, L.; Andreasen, N. C.; Nopoulos, P.

2006-01-01

Background: In a previous study from our lab, adult males with non-syndromic cleft lip and/or palate (NSCLP) were shown to have significantly lower temporal lobe gray matter volume than matched controls. The current study was designed to begin a regional analysis of specific subregions of the temporal lobe. The superior temporal plane (STP) is a…

A male and female RNA marker to infer sex in forensic analysis.

PubMed

van den Berge, M; Sijen, T

2017-01-01

In forensics, DNA profiling is used for the identification of the donor of a trace, while messenger RNA (mRNA) profiling can be applied to identify the cellular origin such as body fluids or organ tissues. The presence of male cell material can be readily assessed by the incorporation of Y-chromosomal markers in quantitation or STR profiling systems. However, no forensic marker exists to positively identify female cell material; merely the presence of female DNA is deduced from the absence of a Y peak, or unbalanced X-Y signals at the Amelogenin locus or unbalanced response of the total and Y-specific quantifier. The presence of two X-chromosomes in female cells invokes dosage compensation, which is achieved through inactivation of one of the X-chromosomes in females. Since this process involves specific RNA molecules, identification of female cellular material may be possible through RNA profiling. Additionally, male material may be identified through RNAs expressed from the Y-chromosome. RNAs preferentially expressed in either sex were assessed for their potential to act as sex markers in forensic RNA assays. To confirm sex-specificity, body fluids and organ tissues of multiple donors of either sex were tested. Additionally, sensitivity of the markers and the suitability of positively identifying male-female mixtures were assessed and degraded samples were used to assess performance of the markers in forensic settings. The addition of sex-specific markers is of added informative value in any RNA profiling system and both markers were incorporated into existing RNA assays that either target body fluids or organs. These are the first forensic assays that enable positive identification of female cellular material. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

CAVITIES AND SHOCKS IN THE GALAXY GROUP HCG 62 AS REVEALED BY CHANDRA, XMM-NEWTON, AND GIANT METREWAVE RADIO TELESCOPE DATA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gitti, Myriam; O'Sullivan, Ewan; Giacintucci, Simona

2010-05-01

We report on the results of an analysis of Chandra, XMM-Newton, and new Giant Metrewave Radio Telescope (GMRT) data of the X-ray bright compact group of galaxies HCG 62, which is one of the few groups known to possess clear, small X-ray cavities in the inner regions. This is part of an ongoing X-ray/low-frequency radio study of 18 groups, initially chosen for the availability of good-quality X-ray data and evidence for active galactic nucleus/hot gas interaction. At higher frequency (1.4 GHz), the HCG 62 cavity system shows minimal if any radio emission, but the new GMRT observations at 235 MHzmore » and 610 MHz clearly detect extended low-frequency emission from radio lobes corresponding to the cavities. By means of the synergy of X-ray and low-frequency radio observations, we compare and discuss the morphology, luminosity, and pressure of the gas and of the radio source. We find that the radio source is radiatively inefficient, with a ratio of radio luminosity to mechanical cavity power of {approx}10{sup -4}, and that the radio pressure of the lobes is about 1 order of magnitude lower than the X-ray pressure of the surrounding thermal gas. Thanks to the high spatial resolution of the Chandra surface brightness and temperature profiles, we also identify a shock front located at 36 kpc to the southwest of the group center, close to the southern radio lobe, with a Mach number {approx}1.5 and a total power which is about 1 order of magnitude higher than the cavity power. Such a shock may have heated the gas in the southern region, as indicated by the temperature map. The shock may also explain the arc-like region of enriched gas seen in the iron abundance map, as this may be produced by a non-Maxwellian electron distribution near its front.« less

Spatial distribution and morphometry of permafrost-related landforms in the Central Pyrenees

NASA Astrophysics Data System (ADS)

Fernandes, Marcelo; Oliva, Marc; Lopes, Luís; Ruiz-Fernández, Jesus; Palma, Pedro; Pereira, Paulo

2017-04-01

Present and past permafrost distribution in the Pyrenees is still under discussion. As in other mid-latitude mountain regions, rock glaciers and protalus lobes are the min indicators of permafrost conditions. In this study, we examine the distribution of these landforms in the Boí valley, a formerly glaciated U-shaped valley ranging from 850 to 3000 m a.s.l. The valley encompasses a surface of 247 km2, mainly composed of granite and shales. The spatial distribution of rock glaciers and protalus lobes and their chronostratigraphic position within the valley allow a better understanding of the climatic and environmental conditions necessary for their development. Geomorphological mapping of these landforms was built using high resolution imagery provided by the Institut Cartogràfic i Geologic de Catalunya, complemented with Basemap ESRI images and Google Earth Pro, and subsequently improved with field observations. The map was generated in a GIS environment following the RCP 77 mapping system of the Centre National de la Recherche Scientifique (CNRS) (Joly, 1997). Several parameters of each landform have been measured (Table 1): area (ha), altitude (maximum, minimum, mean), length (L), width (W), aspect and slope. This information provides accurate characterization of the morphometric properties of these landforms as well as a detailed identification of their spatial distribution. Up to 121 permafrost-related landforms were identified in the Boí valley, including 84 rock glaciers and 37 protalus lobes. Most of the landforms (93% for rock glaciers and 95% for protalus lobes) are located inside the glacial cirques, while the rest is distributed in the valley bottom or slopes of the formerly glaciated valleys. The lowest elevation of both forms is situated at 2100 m a.s.l. Therefore, this altitude may be indicative of the lowest level recording permafrost conditions during the period in which these landforms formed. The maximum elevation of the landforms usually corresponds to the highest parts of the cirques, oscillating between 2700 m a.s.l. for protalus lobes and 2900 m a.s.l. for rock glaciers. Nevertheless, 77% of the rock glaciers and 78% of the protalus lobes are located in the elevation belt ranging from 2200 to 2600 m a.s.l., which is assumed to be the optimal elevation range for their development in the study area. Aspect does not show any prevailing orientation in the case of rock glaciers, though protalus lobe formed preferably on SW aspects (27%), being almost absent in the S, SE and E aspects (only 5%). Regarding morphometry, the average area occupied by the rock glaciers decreases with altitude (6.4 ha to 1.2 ha). This trend is not observed in the case of protalus lobes, which show the largest surfaces between 2200 and 2600 m a.s.l. The W/L ratio reveals that the rock glaciers distributed at lower altitudes are more elongated (W/L ratio > 2), while those at higher elevations are shorter. No clear patterns are observed when comparing the morphology of protalus lobes and the altitude. The average slope of both landforms lies between 21-22°, with a maximum of 29° for rock glaciers and 31° for protalus lobes. The minimum slope necessary for the development of these two landforms is 11°. The geomorphological mapping of the glacial landforms that is being now conducted will allow identifying the chronology of the development of these landforms based on its chronostratigraphic position within the valley and with respect to the four moraine complexes (glacial stages) identified in the area.

[Murder. Italy-USA comparative profiles].

PubMed

Palermo, George B; Mastronardi, Vincenzo

2012-01-01

This paper, through illustrative cases of homicidal typologies, examines the generally accepted theories on the subject: 1) sociological ones by Lorenz to Sutherland and Cressey, by Berkowitz to Wolfgang and Ferracuti and others; 2) neurobiological ones, which include the involvement of the limbic, hippocampal and parietal lobes of the brain; 3) the psychological (psychodynamic) ones which are not disjoint from the types of individual criminal homicide and related aspects. In the discussion of the types of murders, family and extrafamilial murders are then taken into consideration, with the various meanings of revenge, challenge, other reasons linked to robbery, theft, settling scores leading to youth gangs and drive-by-shootings of marginalized adolescents, crimes related to drugs and to mental disorders. Infanticide and multiple murder, including mass murder and serial killer, conclude the work together with the statistics of murders and family murders in Italy compared to USA, specifically to the crime clock.

Functional retrograde amnesia: a multiple case study.

PubMed

Fujiwara, Esther; Brand, Matthias; Kracht, Lutz; Kessler, Josef; Diebel, Andrea; Netz, Johannes; Markowitsch, Hans J

2008-01-01

Functional retrograde amnesia (RA) is a rare pathology and has been rarely studied in detail across different patients. We extensively examined five functional RA patients and compared their neuropsychological profile including anterograde and retrograde memory performance, executive functions, emotional processing, and formally assessed psychiatric symptoms. Across patients, neuropsychological deficits beyond RA were most consistently seen in executive functions and attention suggesting that these dysfunctions contribute to the remote memory deficit. In a majority of the patients, problems in social cognition and emotional behaviour were reflected in Theory of Mind deficits and accompanying psychiatric symptoms. Aberrances in a measure of social desirability were detected, pointing to repressive tendencies in three out of the five patients. Future studies of functional RA patients may investigate more specifically which frontal-lobe associated (dys-) functions contribute to the memory retrieval deficit. Moreover, studying more closely the interaction between social cognition, repressive personality style and memory inhibition in this disease seems worthwhile pursuing.

Levels of word processing and incidental memory: dissociable mechanisms in the temporal lobe.

PubMed

Castillo, E M; Simos, P G; Davis, R N; Breier, J; Fitzgerald, M E; Papanicolaou, A C

2001-11-16

Word recall is facilitated when deep (e.g. semantic) processing is applied during encoding. This fact raises the question of the existence of specific brain mechanisms supporting different levels of information processing that can modulate incidental memory performance. In this study we obtained spatiotemporal brain activation profiles, using magnetic source imaging, from 10 adult volunteers as they performed a shallow (phonological) processing task and a deep (semantic) processing task. When phonological analysis of the word stimuli into their constituent phonemes was required, activation was largely restricted to the posterior portion of the left superior temporal gyrus (area 22). Conversely, when access to lexical/semantic representations was required, activation was found predominantly in the left middle temporal gyrus and medial temporal cortex. The differential engagement of each mechanism during word encoding was associated with dramatic changes in subsequent incidental memory performance.

Clinical and radiological features of Marchiafava–Bignami disease

PubMed Central

Dong, Xiaoyu; Bai, Chaobo; Nao, Jianfei

2018-01-01

Abstract Marchiafava–Bignami disease (MBD) is a rare neurological disease usually associated with chronic alcoholism and characterized by demyelination and necrosis. Our aims were to describe the clinicoradiological features and identify factors that may affect the prognosis of patients with MBD. We examined clinical manifestations, laboratory results, and neuroradiological features of 9 patients with MBD. The patients were classified into 2 subgroups (favorable and poor outcome subgroups) based on the Modified Oxford Handicap Scale (MOSH). In addition, we compared the clinical and neuroimaging features between the 2 subgroups. Nine adult male patients (age of onset range 37–62 years, with a mean age of 47.00 ± 14.50 years) were included in this study. According to MOSH, 4 patients were placed in the poor outcome subgroup (MOHS ≥ 3), 5 patients were placed in the favorable outcome subgroup (MOHS ≤ 2). Relatively high score of MAST-C (≥6) (P = .008), extracallosal lesions (P = .048), GCS (P = .026), cerebral lobe impairment (P = .048) was significantly more common in the poor outcome subgroup. Clinical manifestations of MBD are variable and lack specificity. Early diagnosis by relatively specific performance of bisymmetric lesions in corpus callosum of diffusion-weighted imaging (DWI) may affect the prognosis. The prognosis of patients with severe disturbance of consciousness, heavy alcohol consumption, extracallosal lesions, cerebral lobe impairment is probably unfavorable. PMID:29384842

Lack of association between temporal lobe epilepsy and a novel polymorphism in the alpha 2 subunit gene (ATP1A2) of the sodium potassium transporting ATPase.

PubMed

Buono, R J; Ferraro, T N; O'Connor, M J; Sperling, M R; Abbey, M; Finanger, E; Lohoff, F; Mulholland, N; Berrettini, W H

2000-02-07

Genetic linkage studies in rodents and humans have identified specific chromosomal regions harboring seizure susceptibility genes. We have identified a novel polymorphism in the human alpha 2 subunit gene (ATP1A2) of the sodium potassium transporting ATPase (NaK-pump), a candidate gene for human temporal lobe epilepsy (TLE) based on its chromosomal location and function in ion homeostasis. The polymorphism consists of a four base pair insertion 12 base pairs upstream of the start of exon 2. We performed an association study between this polymorphism and TLE. Our study did not find a significant difference in the frequency of this polymorphism between TLE patients and controls, indicating that this variation is not a major susceptibility factor. However, since the number of patients studied so far is small and the functional consequence of the polymorphism is unknown, the variation may yet be found to play a minor role in increased risk for seizure susceptibility. In contrast to the findings in TLE patients and controls, we did find a significant difference in the frequency of the variation between African Americans and persons of European descent. This finding demonstrates the potential effect of population stratification on studies of this type and supports the growing use of parental and familial samples for controls in association studies. Further study of this polymorphism is warranted as it may be involved in other disease processes for which there are known ethnic-specific susceptibilities. Am. J. Med. Genet. (Neuropsychiatr. Genet.) 96:79-83, 2000. Copyright 2000 Wiley-Liss, Inc.

The magnetospheric lobe at geosynchronous orbit

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thomsen, M.F.; Bame, S.J.; McComas, D.J.

1994-09-01

On rare occasions, satellites at geosynchronous altitude enter the magnetospheric lobe, characterized by extremely low ion fluxes between 1 eV and 40 keV and electron fluxes above a few hundred eV. One year of plasma observations from two simultaneously operating spacecraft at synchronous orbit is surveyed for lobe encounters. A total of 34 full encounters and 56 apparent near encounters are identified, corresponding to {approximately}0.06% of the total observation time. Unlike energetic particle (E>40 keV) dropouts studied earlier, there is a strong tendency for the lobe encounters to occur postmidnight, as late as 07 local time. The two spacecraft encountermore » the lobe with different rates and in different seasons. These occurrence properties are not simply explicable in terms of the orbital geometry in either the solar magnetic or the geocentric solar magnetospheric coordinate system. A composite coordinate system which previously organized more energetic particle dropouts is somewhat more successful in organizing the lobe encounters, suggesting that solar wind distortion of the magnetic equatorial plane away from the dipole location and toward the antisolar direction may be largely responsible for these dropouts. The authors results further suggest that this distortion persists even sunward of the dawn-dusk terminator. However, a simple dawn-dusk symmetric distortion does not fully account for all the seasonal and local time asymmetries in the occurrence of the lobe encounters; thus there is probably an additional dawn-dusk asymmetry in the distorted field. The lobe encounters are strongly associated with magnetospheric activity and tend to occur in association with rare magnetosheath encounters at synchronous orbit. It thus appears that the presence of the lobe at geosynchronous orbit is the result of major, probably asymmetric modifications of the magnetospheric field geometry in times of strong disturbance. 19 refs., 7 figs., 1 tab.« less

Microwave Transversal Equalizer.

DTIC Science & Technology

1980-05-01

AD-AO?7 603 EATONCORP MELVILLE NY AIL DIV F/6 9/5 MICROWAVE TRANSVERSAL EQUALIZER .(U) MAY 80 J WOLCZOK. 6 KANISCHAK F 3 0602-T8-C-0352 UNCLASSIFIED... Equalizer (MTE) Side-lobe distortion Equalization II Automation ABSTRACT (Continue on revere side It necesary and identify by block numb.r) A...Microwave Transversal Equalizer has been designed, fabricated, and installed at RADC and is capable of reducing side-lobe distortion levels of -18 dBm to

Automated MRI parcellation of the frontal lobe

PubMed Central

Ranta, Marin E.; Chen, Min; Crocetti, Deana; Prince, Jerry L.; Subramaniam, Krish; Fischl, Bruce; Kaufmann, Walter E.; Mostofsky, Stewart H.

2014-01-01

Examination of associations between specific disorders and physical properties of functionally relevant frontal lobe sub-regions is a fundamental goal in neuropsychiatry. Here we present and evaluate automated methods of frontal lobe parcellation with the programs FreeSurfer(FS) and TOADS-CRUISE(T-C), based on the manual method described in Ranta et al. (2009) in which sulcal-gyral landmarks were used to manually delimit functionally relevant regions within the frontal lobe: i.e., primary motor cortex, anterior cingulate, deep white matter, premotor cortex regions (supplementary motor complex, frontal eye field and lateral premotor cortex) and prefrontal cortex (PFC) regions (medial PFC, dorsolateral PFC, inferior PFC, lateral orbitofrontal cortex (OFC) and medial OFC). Dice's coefficient, a measure of overlap, and percent volume difference were used to measure the reliability between manual and automated delineations for each frontal lobe region. For FS, mean Dice's coefficient for all regions was 0.75 and percent volume difference was 21.2%. For T-C the mean Dice's coefficient was 0.77 and the mean percent volume difference for all regions was 20.2%. These results, along with a high degree of agreement between the two automated methods (mean Dice's coefficient = 0.81, percent volume difference = 12.4%) and a proof-of-principle group difference analysis that highlights the consistency and sensitivity of the automated methods, indicate that the automated methods are valid techniques for parcellation of the frontal lobe into functionally relevant sub-regions. Thus, the methodology has the potential to increase efficiency, statistical power and reproducibility for population analyses of neuropsychiatric disorders with hypothesized frontal lobe contributions. PMID:23897577

Epilepsy diagnostic and treatment needs identified with a collaborative database involving tertiary centers in France.

PubMed

Chipaux, Mathilde; Szurhaj, William; Vercueil, Laurent; Milh, Mathieu; Villeneuve, Nathalie; Cances, Claude; Auvin, Stéphane; Chassagnon, Serge; Napuri, Sylvia; Allaire, Catherine; Derambure, Philippe; Marchal, Cécile; Caubel, Isabelle; Ricard-Mousnier, Brigitte; N'Guyen The Tich, Sylvie; Pinard, Jean-Marc; Bahi-Buisson, Nadia; de Baracé, Claire; Kahane, Philippe; Gautier, Agnès; Hamelin, Sophie; Coste-Zeitoun, Delphine; Rosenberg, Sarah-Dominique; Clerson, Pierre; Nabbout, Rima; Kuchenbuch, Mathieu; Picot, Marie-Christine; Kaminska, Anna

2016-05-01

To obtain perspective on epilepsy in patients referred to tertiary centers in France, and describe etiology, epilepsy syndromes, and identify factors of drug resistance and comorbidities. We performed a cross-sectional analysis of the characteristics of 5,794 pediatric and adult patients with epilepsy included in a collaborative database in France between 2007 and 2013. Comparisons between groups used Student's t-test or Fisher's exact test for binary or categorical variables. Factors associated with drug resistance and intellectual disability were evaluated in multi-adjusted logistic regression models. Mean age at inclusion was 17.9 years; children accounted for 67%. Epilepsy was unclassified in 20% of patients, and etiology was unknown in 65%, including those with idiopathic epilepsies. Etiologies differed significantly in adult- when compared to pediatric-onset epilepsy; however, among focal structural epilepsies, mesial temporal lobe epilepsy with hippocampal sclerosis began as often in the pediatric as in adult age range. Drug resistance concerned 53% of 4,210 patients evaluable for seizure control and was highest in progressive myoclonic epilepsy (89%), metabolic diseases (84%), focal cortical dysplasia (70%), other cortical malformations (69%), and mesial temporal lobe epilepsy with hippocampal sclerosis (67%). Fifty-nine percent of patients with focal structural epilepsy and 69% with epileptic encephalopathies were drug resistant; however, 40-50% of patients with West syndrome and epileptic encephalopathy with continuous spike-and-waves during sleep were seizure-free. Ages at onset in infancy and in young adults shared the highest risk of drug resistance. Epilepsy onset in infancy comprised the highest risk of intellectual disability, whereas specific cognitive impairment affected 36% of children with idiopathic focal epilepsy. Our study provides a snapshot on epilepsy in patients referred to tertiary centers and discloses needs for diagnosis and treatment. Large databases help identify patients with rare conditions that could benefit from specific prospective studies. Wiley Periodicals, Inc. © 2016 International League Against Epilepsy.

Use of clinical and neuroimaging characteristics to distinguish temporal lobe herpes simplex encephalitis from its mimics.

PubMed

Chow, Felicia C; Glaser, Carol A; Sheriff, Heather; Xia, Dongxiang; Messenger, Sharon; Whitley, Richard; Venkatesan, Arun

2015-05-01

We describe the spectrum of etiologies associated with temporal lobe (TL) encephalitis and identify clinical and radiologic features that distinguish herpes simplex encephalitis (HSE) from its mimics. We reviewed all adult cases of encephalitis with TL abnormalities on magnetic resonance imaging (MRI) from the California Encephalitis Project. We evaluated the association between specific clinical and MRI characteristics and HSE compared with other causes of TL encephalitis and used multivariate logistic modeling to identify radiologic predictors of HSE. Of 251 cases of TL encephalitis, 43% had an infectious etiology compared with 16% with a noninfectious etiology. Of infectious etiologies, herpes simplex virus was the most commonly identified agent (n = 60), followed by tuberculosis (n = 8) and varicella zoster virus (n = 7). Of noninfectious etiologies, more than half (n = 21) were due to autoimmune disease. Patients with HSE were older (56.8 vs 50.2 years; P = .012), more likely to be white (53% vs 35%; P = .013), more likely to present acutely (88% vs 64%; P = .001) and with a fever (80% vs 49%; P < .001), and less likely to present with a rash (2% vs 15%; P = .010). In a multivariate model, bilateral TL involvement (odds ratio [OR], 0.38; 95% confidence interval [CI], .18-.79; P = .010) and lesions outside the TL, insula, or cingulate (OR, 0.37; 95% CI, .18-.74; P = .005) were associated with lower odds of HSE. In addition to HSE, other infectious and noninfectious etiologies should be considered in the differential diagnosis for TL encephalitis, depending on the presentation. Specific clinical and imaging features may aid in distinguishing HSE from non-HSE causes of TL encephalitis. © The Author 2015. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Urine protein profiling identified alpha-1-microglobulin and haptoglobin as biomarkers for early diagnosis of acute allograft rejection following kidney transplantation.

PubMed

Stubendorff, Beatrice; Finke, Stephanie; Walter, Martina; Kniemeyer, Olaf; von Eggeling, Ferdinand; Gruschwitz, Torsten; Steiner, Thomas; Ott, Undine; Wolf, Gunter; Wunderlich, Heiko; Junker, Kerstin

2014-12-01

Early diagnosis of acute rejection and effective immunosuppressive therapy lead to improvement in graft survival following kidney transplantation. In this study, we aimed to establish a urinary protein profile suitable to distinguish between patients with rejection and stable graft function and to predict acute rejection based on postoperatively collected urine samples. A further objective was to identify candidate proteins for the use as biomarkers in clinical practice. Urine samples of 116 kidney recipients were included. Rejection was proven by biopsy (n = 58), and stable transplant function was monitored for at least 2 years (n = 58). Postoperative urine samples were collected between 3rd and 10th day following transplantation. Urinary protein profiles were obtained by surface-enhanced laser desorption/ionization time-of-flight mass spectrometry. Protein identification and validation were performed using multiplex fluorescence 2DE, peptide mass fingerprinting and enzyme-linked immunosorbent assay. A protein profile including four mass peaks differentiated acute rejection from stable transplants at the time point of rejection and at the postoperative state with 73 % sensitivity and 88 % specificity. Alpha-1-microglobulin (A1MG) and Haptoglobin (Hp) were identified as putative rejection biomarkers. Protein levels were significantly higher in postoperative urine from patients with rejection (A1MG 29.13 vs. 22.06 μg/ml, p = 0.001; Hp 628.34 vs. 248.57 ng/ml, p = 0.003). The combination of both proteins enabled the diagnosis of early rejection with 85 % sensitivity and 80 % specificity. Protein profiling using mass spectrometry is suitable for noninvasive detection of rejection-specific changes following kidney transplantation. A specific protein profile enables the prediction of early acute allograft rejection in the immediate postoperative period. A1MG and Hp appear to be reliable rejection biomarkers.

Context sensitive formulations of antenna pattern correction and side lobe compensation for NOSS/LAMMR real time processing

NASA Technical Reports Server (NTRS)

Chin, R. T.; Beaudet, P. R.

1981-01-01

Large antenna multi-channel microwave radiometer (LAMMR) software specifications were written for LAMMR ground processing. There is a need to determine more computationally-efficient antenna temperature correction methods in compensating side lobe contributions especially near continents, islands and weather fronts. One of the major conclusions was that the antenna pattern corrections (APC) processes did not accomplish the implied goals of compensating for the antenna side lobe influences on brightness temperature. A-priori knowledge of land/water locations was shown to be needed and had to be incorporated in a context sensitive APC process if the artifacts caused by land presence is to be avoided. The high temperatures in land regions can severely bias the lower ocean response.

Entorhinal Tau Pathology, Episodic Memory Decline, and Neurodegeneration in Aging.

PubMed

Maass, Anne; Lockhart, Samuel N; Harrison, Theresa M; Bell, Rachel K; Mellinger, Taylor; Swinnerton, Kaitlin; Baker, Suzanne L; Rabinovici, Gil D; Jagust, William J

2018-01-17

The medial temporal lobe (MTL) is an early site of tau accumulation and MTL dysfunction may underlie episodic-memory decline in aging and dementia. Postmortem data indicate that tau pathology in the transentorhinal cortex is common by age 60, whereas spread to neocortical regions and worsening of cognition is associated with β-amyloid (Aβ). We used [ 18 F]AV-1451 and [ 11 C]PiB positron emission tomography, structural MRI, and neuropsychological assessment to investigate how in vivo tau accumulation in temporal lobe regions, Aβ, and MTL atrophy contribute to episodic memory in cognitively normal older adults ( n = 83; age, 77 ± 6 years; 58% female). Stepwise regressions identified tau in MTL regions known to be affected in old age as the best predictor of episodic-memory performance independent of Aβ status. There was no interactive effect of MTL tau with Aβ on memory. Higher MTL tau was related to higher age in the subjects without evidence of Aβ. Among temporal lobe subregions, episodic memory was most strongly related to tau-tracer uptake in the parahippocampal gyrus, particularly the posterior entorhinal cortex, which in our parcellation includes the transentorhinal cortex. In subjects with longitudinal MRI and cognitive data ( n = 57), entorhinal atrophy mirrored patterns of tau pathology and their relationship with memory decline. Our data are consistent with neuropathological studies and further suggest that entorhinal tau pathology underlies memory decline in old age even without Aβ. SIGNIFICANCE STATEMENT Tau tangles and β-amyloid (Aβ) plaques are key lesions in Alzheimer's disease (AD) but both pathologies also occur in cognitively normal older people. Neuropathological data indicate that tau tangles in the medial temporal lobe (MTL) underlie episodic-memory impairments in AD dementia. However, it remains unclear whether MTL tau pathology also accounts for memory impairments often seen in elderly people and how Aβ affects this relationship. Using tau-specific and Aβ-specific positron emission tomography tracers, we show that in vivo MTL tau pathology is associated with episodic-memory performance and MTL atrophy in cognitively normal adults, independent of Aβ. Our data point to MTL tau pathology, particularly in the entorhinal cortex, as a substrate of age-related episodic-memory loss. Copyright © 2018 the authors 0270-6474/18/380530-14$15.00/0.

Altered temporal lobe white matter lipid ion profiles in an experimental model of sporadic Alzheimer's disease.

PubMed

Tong, Ming; Leão, Raiane; Vimbela, Gina V; Yalcin, Emine B; Kay, Jared; Krotow, Alexander; de la Monte, Suzanne M

2017-07-01

White matter is an early and important yet under-evaluated target of Alzheimer's disease (AD). Metabolic impairments due to insulin and insulin-like growth factor resistance contribute to white matter degeneration because corresponding signal transduction pathways maintain oligodendrocyte function and survival. This study utilized a model of sporadic AD in which adult Long Evans rats administered intracerebral streptozotocin (i.c. STZ) developed AD-type neurodegeneration. Temporal lobe white matter lipid ion profiles were characterized by matrix-assisted laser desorption/ionization-imaging mass spectrometry (MALDI-IMS). Although the lipid ion species expressed in the i.c. STZ and control groups were virtually identical, i.c. STZ mainly altered the abundances of various lipid ions. Correspondingly, the i.c. STZ group was distinguished from control by principal component analysis and data bar plots. i.c. STZ mainly reduced expression of lipid ions with low m/z's (less than 810) as well as the upper range m/z lipids (m/z 964-986), and increased expression of lipid ions with m/z's between 888 and 937. Phospholipids were mainly included among the clusters inhibited by i.c. STZ, while both sulfatides and phospholipids were increased by i.c. STZ. However, Chi-Square analysis demonstrated significant i.c. STZ-induced trend reductions in phospholipids and increases in sulfatides (P<0.00001). The i.c. STZ model of sporadic AD is associated with broad and sustained abnormalities in temporal lobe white matter lipids. The findings suggest that the i.c. STZ model could be used for pre-clinical studies to assess therapeutic measures for their ability to restore white matter integrity in AD. Copyright © 2017 Elsevier Inc. All rights reserved.

Long-Term Seizure, Quality of Life, Depression, and Verbal Memory Outcomes in a Controlled Mesial Temporal Lobe Epilepsy Surgical Series Using Portuguese-Validated Instruments.

PubMed

Dias, Luis Augusto; Angelis, Geisa de; Teixeira, Wagner Afonso; Casulari, Luiz Augusto

2017-08-01

We aimed to evaluate long-term surgical outcomes in patients treated for mesial temporal lobe epilepsy compared with a similar group of patients who underwent a preoperative evaluation. Patient interviews were conducted by an independent neuropsychologist and included a sociodemographic questionnaire and validated versions of the Beck Depression Inventory-II, Adverse Events Profile, Quality of Life in Epilepsy-31, and Rey Auditory Verbal Learning Test. Seventy-one patients who underwent surgery and 20 who underwent mesial temporal lobe epilepsy preoperative evaluations were interviewed. After an 81-month mean postoperative follow-up, 44% of the surgical patients achieved complete seizure relief according to the Engel classification and 68% according to the International League Against Epilepsy classification. The surgical group had a significantly lower prevalence of depression (P = 0.002) and drug-related adverse effects (P = 0.002). Improvement on unemployment (P = 0.02) was achieved but not on driving or education. Delayed verbal memory recall was impaired in 76% of the surgical and 65% of the control cases (P = 0.32). Regarding the Quality of Life in Epilepsy-31, the operated patients scored higher in their total score (mean, 75.44 vs. mean, 60.08; P < 0.001) and in all but the cognitive functioning domain irrespective of the follow-up length. Seizure control, Beck Depression Score, and Adverse Events Profile severity explained 73% of the variance in the surgical group quality of life. Our study found that, although surgical treatment was effective, its impact on social indicators was modest. Moreover, the self-reported quality of life relied not only on seizure control but also on depressive symptoms and antiepileptic drug burden. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

Developmental trajectories of the fronto-temporal lobes from infancy to early adulthood in healthy individuals.

PubMed

Tanaka, Chiaki; Matsui, Mie; Uematsu, Akiko; Noguchi, Kyo; Miyawaki, Toshio

2012-01-01

Brain development during early life in healthy individuals is rapid and dynamic, indicating that this period plays a very important role in neural and functional development. The frontal and temporal lobes are known to play a particularly important role in cognition. The study of healthy frontal and temporal lobe development in children is therefore of considerable importance. A better understanding of how these brain regions develop could also aid in the diagnosis and treatment of neurodevelopmental disorders. Some developmental studies have used magnetic resonance imaging (MRI) to examine infant brains, but it remains the case that relatively little is known about cortical brain development in the first few years of life. In the present study we examined whole brain, temporal lobe and frontal lobe developmental trajectories from infancy to early adulthood in healthy individuals, considering gender and brain hemisphere differences. We performed a cross-sectional, longitudinal morphometric MRI study of 114 healthy individuals (54 females and 60 males) aged 1 month to 25 years old (mean age ± SD 8.8 ± 6.9). We measured whole brain, temporal and frontal lobe gray matter (GM)/white matter (WM) volumes, following previously used protocols. There were significant non-linear age-related volume changes in all regions. Peak ages of whole brain, temporal lobe and frontal lobe development occurred around pre-adolescence (9-12 years old). GM volumes for all regions increased significantly as a function of age. Peak age was nevertheless lobe specific, with a pattern of earlier peak ages for females in both temporal and frontal lobes. Growth change in whole brain GM volume was larger in males than in females. However, GM volume growth changes for the temporal and frontal lobes showed a somewhat different pattern. GM volume for both temporal and frontal lobes showed a greater increase in females until around 5-6 years old, at which point this tendency reversed (GM volume changes in males became greater), with male GM volume increasing for a longer time than that of females. WM volume growth changes were similar across regions, all increasing rapidly until early childhood but slowing down thereafter. All regions displayed significant rightward volumetric asymmetry regardless of sex. Furthermore, the right temporal and frontal lobes showed a greater volumetric increase than the left for the first several years, with this tendency reversing at around 6 years of age. In addition, the left frontal and temporal lobes increased in volume for a longer period of time. Taken together, these findings indicated that brain developmental trajectories differ depending on brain region, sex and brain hemisphere. Gender-related factors such as sex hormones and functional laterality may affect brain development. Copyright © 2012 S. Karger AG, Basel.

Associative episodic memory and recollective processes in childhood temporal lobe epilepsy.

PubMed

Martins, Sylvie; Guillery-Girard, Bérengère; Clochon, Patrice; Bulteau, Christine; Hertz-Pannier, Lucie; Chiron, Catherine; Eustache, Francis; Jambaqué, Isabelle

2015-03-01

While the current literature on children suffering from temporal lobe epilepsy (CTLE) mostly focuses on material-related episodic memory deficits according to seizure-onset lateralization, the present study examined associative episodic memory according to the type of information to memorize (e.g., factual, spatial, and sequential) and further investigated subjective and objective recollection. Eleven children with left temporal lobe epilepsy (LTLE), 10 children with right temporal lobe epilepsy (RTLE), among whom 9 displayed hippocampal sclerosis (HS), and 42 healthy controls completed the WHAT-WHEN-WHERE protocol (Guillery-Girard et al., 2013). Group comparisons were first conducted according to the affected side and second according to the underlying pathology. Results showed associative memory impairments in patients irrespective of the affected side. Moreover, this study revealed that HS is particularly deleterious to associative and subjective recollection in CTLE. In addition, this study emphasizes the need for assessing episodic memory in childhood TLE beyond material specificity. Copyright © 2015 Elsevier Inc. All rights reserved.

Rethinking cognition and behavior in the new classification for childhood epilepsy: Examples from frontal lobe and temporal lobe epilepsies.

PubMed

Smith, Mary Lou

2016-11-01

The new approach to classification of the epilepsies emphasizes the role of dysfunction in networks in defining types of epilepsies. This paper reviews the structural and neuropsychological deficits in two types of childhood epilepsy: frontal lobe and temporal lobe epilepsy. The evidence for and against a pattern of specificity of deficits in executive function and memory associated with these two types of epilepsies is presented. The evidence varies with the methodologies used in the studies, but direct comparison of the two types of epilepsies does not suggest a clear-cut mapping of function onto structure. These findings are discussed in light of the concept of network dysfunction. The evidence supports the conceptualization of epilepsy as a network disease. Implications for future work in the neuropsychology of pediatric epilepsy are suggested. This article is part of a Special Issue entitled "The new approach to classification: Rethinking cognition and behavior in epilepsy". Copyright © 2016 Elsevier Inc. All rights reserved.

Longitudinal positron emission tomography imaging of glial cell activation in a mouse model of mesial temporal lobe epilepsy: Toward identification of optimal treatment windows.

PubMed

Nguyen, Duc-Loc; Wimberley, Catriona; Truillet, Charles; Jego, Benoit; Caillé, Fabien; Pottier, Géraldine; Boisgard, Raphaël; Buvat, Irène; Bouilleret, Viviane

2018-06-01

Mesiotemporal lobe epilepsy is the most common type of drug-resistant partial epilepsy, with a specific history that often begins with status epilepticus due to various neurological insults followed by a silent period. During this period, before the first seizure occurs, a specific lesion develops, described as unilateral hippocampal sclerosis (HS). It is still challenging to determine which drugs, administered at which time point, will be most effective during the formation of this epileptic process. Neuroinflammation plays an important role in pathophysiological mechanisms in epilepsy, and therefore brain inflammation biomarkers such as translocator protein 18 kDa (TSPO) can be potent epilepsy biomarkers. TSPO is associated with reactive astrocytes and microglia. A unilateral intrahippocampal kainate injection mouse model can reproduce the defining features of human temporal lobe epilepsy with unilateral HS and the pattern of chronic pharmacoresistant temporal seizures. We hypothesized that longitudinal imaging using TSPO positron emission tomography (PET) with 18 F-DPA-714 could identify optimal treatment windows in a mouse model during the formation of HS. The model was induced into the right dorsal hippocampus of male C57/Bl6 mice. Micro-PET/computed tomographic scanning was performed before model induction and along the development of the HS at 7 days, 14 days, 1 month, and 6 months. In vitro autoradiography and immunohistofluorescence were performed on additional mice at each time point. TSPO PET uptake reached peak at 7 days and mostly related to microglial activation, whereas after 14 days, reactive astrocytes were shown to be the main cells expressing TSPO, reflected by a continuing increased PET uptake. TSPO-targeted PET is a highly potent longitudinal biomarker of epilepsy and could be of interest to determine the therapeutic windows in epilepsy and to monitor response to treatment. Wiley Periodicals, Inc. © 2018 International League Against Epilepsy.

Identification of a pathway for intelligible speech in the left temporal lobe

PubMed Central

Scott, Sophie K.; Blank, C. Catrin; Rosen, Stuart; Wise, Richard J. S.

2017-01-01

Summary It has been proposed that the identification of sounds, including species-specific vocalizations, by primates depends on anterior projections from the primary auditory cortex, an auditory pathway analogous to the ventral route proposed for the visual identification of objects. We have identified a similar route in the human for understanding intelligible speech. Using PET imaging to identify separable neural subsystems within the human auditory cortex, we used a variety of speech and speech-like stimuli with equivalent acoustic complexity but varying intelligibility. We have demonstrated that the left superior temporal sulcus responds to the presence of phonetic information, but its anterior part only responds if the stimulus is also intelligible. This novel observation demonstrates a left anterior temporal pathway for speech comprehension. PMID:11099443

Thalamotemporal alteration and postoperative seizures in temporal lobe epilepsy

PubMed Central

Richardson, Mark P.; Schoene‐Bake, Jan‐Christoph; O'Muircheartaigh, Jonathan; Elkommos, Samia; Kreilkamp, Barbara; Goh, Yee Yen; Marson, Anthony G.; Elger, Christian; Weber, Bernd

2015-01-01

Objective There are competing explanations for persistent postoperative seizures after temporal lobe surgery. One is that 1 or more particular subtypes of mesial temporal lobe epilepsy (mTLE) exist that are particularly resistant to surgery. We sought to identify a common brain structural and connectivity alteration in patients with persistent postoperative seizures using preoperative quantitative magnetic resonance imaging and diffusion tensor imaging (DTI). Methods We performed a series of studies in 87 patients with mTLE (47 subsequently rendered seizure free, 40 who continued to experience postoperative seizures) and 80 healthy controls. We investigated the relationship between imaging variables and postoperative seizure outcome. All patients had unilateral temporal lobe seizure onset, had ipsilateral hippocampal sclerosis as the only brain lesion, and underwent amygdalohippocampectomy. Results Quantitative imaging factors found not to be significantly associated with persistent seizures were volumes of ipsilateral and contralateral mesial temporal lobe structures, generalized brain atrophy, and extent of resection. There were nonsignificant trends for larger amygdala and entorhinal resections to be associated with improved outcome. However, patients with persistent seizures had significant atrophy of bilateral dorsomedial and pulvinar thalamic regions, and significant alterations of DTI‐derived thalamotemporal probabilistic paths bilaterally relative to those patients rendered seizure free and controls, even when corrected for extent of mesial temporal lobe resection. Interpretation Patients with bihemispheric alterations of thalamotemporal structural networks may represent a subtype of mTLE that is resistant to temporal lobe surgery. Increasingly sensitive multimodal imaging techniques should endeavor to transform these group‐based findings to individualize prediction of patient outcomes. Ann Neurol 2015;77:760–774 PMID:25627477

Increased Prevalence of Bent Lobes for Double-lobed Radio Galaxies in Dense Environments

NASA Astrophysics Data System (ADS)

Silverstein, Ezekiel M.; Anderson, Michael E.; Bregman, Joel N.

2018-01-01

Double-lobed radio galaxies (DLRGs) often have radio lobes that subtend an angle of less than 180°, and these bent DLRGs have been shown to associate preferentially with galaxy clusters and groups. In this study, we utilize a catalog of DLRGs in SDSS quasars with radio lobes visible in VLA FIRST 20 cm radio data. We cross-match this catalog against three catalogs of galaxies over the redshift range 0< z< 0.70, obtaining 81 tentative matches. We visually examine each match and apply a number of selection criteria, eventually obtaining a sample of 44 securely detected DLRGs, which are paired to a nearby massive galaxy, galaxy group, or galaxy cluster. Most of the DLRGs identified in this manner are not central galaxies in the systems to which they are matched. Using this sample, we quantify the projected density of these matches as a function of projected separation from the central galaxy, finding a very steep decrease in matches as the impact parameter increases (for {{Σ }}\\propto {b}-m we find m={2.5}-0.3+0.4) out to b∼ 2 Mpc. In addition, we show that the fraction of DLRGs with bent lobes also decreases with radius, so that if we exclude DLRGs associated with the central galaxy in the system, the bent fraction is 78% within 1 Mpc and 56% within 2 Mpc, compared to just 29% in the field; these differences are significant at 3.6σ and 2.8σ , respectively. This behavior is consistent with ram pressure being the mechanism that causes the lobes to bend.

Astrocyte uncoupling as a cause of human temporal lobe epilepsy.

PubMed

Bedner, Peter; Dupper, Alexander; Hüttmann, Kerstin; Müller, Julia; Herde, Michel K; Dublin, Pavel; Deshpande, Tushar; Schramm, Johannes; Häussler, Ute; Haas, Carola A; Henneberger, Christian; Theis, Martin; Steinhäuser, Christian

2015-05-01

Glial cells are now recognized as active communication partners in the central nervous system, and this new perspective has rekindled the question of their role in pathology. In the present study we analysed functional properties of astrocytes in hippocampal specimens from patients with mesial temporal lobe epilepsy without (n = 44) and with sclerosis (n = 75) combining patch clamp recording, K(+) concentration analysis, electroencephalography/video-monitoring, and fate mapping analysis. We found that the hippocampus of patients with mesial temporal lobe epilepsy with sclerosis is completely devoid of bona fide astrocytes and gap junction coupling, whereas coupled astrocytes were abundantly present in non-sclerotic specimens. To decide whether these glial changes represent cause or effect of mesial temporal lobe epilepsy with sclerosis, we developed a mouse model that reproduced key features of human mesial temporal lobe epilepsy with sclerosis. In this model, uncoupling impaired K(+) buffering and temporally preceded apoptotic neuronal death and the generation of spontaneous seizures. Uncoupling was induced through intraperitoneal injection of lipopolysaccharide, prevented in Toll-like receptor4 knockout mice and reproduced in situ through acute cytokine or lipopolysaccharide incubation. Fate mapping confirmed that in the course of mesial temporal lobe epilepsy with sclerosis, astrocytes acquire an atypical functional phenotype and lose coupling. These data suggest that astrocyte dysfunction might be a prime cause of mesial temporal lobe epilepsy with sclerosis and identify novel targets for anti-epileptogenic therapeutic intervention. © The Author (2015). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

SU-E-J-122: Detecting Treatment-Induced Metabolic Abnormalities in Craniopharyngioma Patients Undergoing Surgery and Proton Therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hua, C; Shulkin, B; Li, Y

Purpose: To identify treatment-induced defects in the brain of children with craniopharyngioma receiving surgery and proton therapy using fluorodeoxyglucose positron emission tomography (FDG PET). Methods: Forty seven patients were enrolled on a clinical trial for craniopharyngioma with serial imaging and functional evaluations. Proton therapy was delivered using the double-scattered beams with a prescribed dose of 54 Cobalt Gray Equivalent. FDG tracer uptake in each of 63 anatomical regions was computed after warping PET images to a 3D reference template in Talairach coordinates. Regional uptake was deemed significantly low or high if exceeding two standard deviations of normal population from themore » mean. For establishing the normal ranges, 132 children aged 1–20 years with noncentral nervous system related diseases and normal-appearing cerebral PET scans were analyzed. Age- and gender-dependent regional uptake models were developed by linear regression and confidence intervals were calculated. Results: Most common PET abnormality before proton therapy was significantly low uptake in the frontal lobe, the occipital lobe (particularly in cuneus), the medial and ventral temporal lobe, cingulate gyrus, caudate nuclei, and thalamus. They were related to injury from surgical corridors, tumor mass effect, insertion of a ventricular catheter, and the placement of an Ommaya reservoir. Surprisingly a significantly high uptake was observed in temporal gyri and the parietal lobe. In 13 patients who already completed 18-month PET scans, metabolic abnormalities improved in 11 patients from baseline. One patient had persistent abnormalities. Only one revealed new uptake abnormalities in thalamus, brainstem, cerebellum, and insula. Conclusion: Postoperative FDG PET of craniopharyngioma patients revealed metabolic abnormalities in specific regions of the brain. Proton therapy did not appear to exacerbate these surgery- and tumor-induced defects. In patients with persistent and new abnormalities, continued investigation on clinical symptoms and cognitive outcomes is ongoing to establish the association and predictive values of metabolic imaging.« less

Genital automatisms: Reappraisal of a remarkable but ignored symptom of focal seizures.

PubMed

Dede, Hava Özlem; Bebek, Nerses; Gürses, Candan; Baysal-Kıraç, Leyla; Baykan, Betül; Gökyiğit, Ayşen

2018-03-01

Genital automatisms (GAs) are uncommon clinical phenomena of focal seizures. They are defined as repeated fondling, grabbing, or scratching of the genitals. The aim of this study was to determine the lateralizing and localizing value and associated clinical characteristics of GAs. Three hundred thirteen consecutive patients with drug-resistant seizures who were referred to our tertiary center for presurgical evaluation between 2009 and 2016 were investigated. The incidence of specific kinds of behavior, clinical semiology, associated symptoms/signs with corresponding ictal electroencephalography (EEG) findings, and their potential role in seizure localization and lateralization were evaluated. Fifteen (4.8%) of 313 patients had GAs. Genital automatisms were identified in 19 (16.4%) of a total 116 seizures. Genital automatisms were observed to occur more often in men than in women (M/F: 10/5). Nine of fifteen patients (60%) had temporal lobe epilepsy (right/left: 4/5) and three (20%) had frontal lobe epilepsy (right/left: 1/2), whereas the remaining two patients could not be classified. One patient was diagnosed as having Rasmussen encephalitis. Genital automatisms were ipsilateral to epileptic focus in 12 patients and contralateral in only one patient according to ictal-interictal EEG and neuroimaging findings. Epileptic focus could not be lateralized in the last 2 patients. Genital automatisms were associated with unilateral hand automatisms such as postictal nose wiping or manual automatisms in 13 (86.7%) of 15 and contralateral dystonia was seen in 6 patients. All patients had amnesia of the performance of GAs. Genital automatisms are more frequent in seizures originating from the temporal lobe, and they can also be seen in frontal lobe seizures. Genital automatisms seem to have a high lateralizing value to the ipsilateral hemisphere and are mostly concordant with other unilateral hand automatisms. Men exhibit GAs more often than women. Copyright © 2017 Elsevier Inc. All rights reserved.

Impairments in proverb interpretation following focal frontal lobe lesions☆

PubMed Central

Murphy, Patrick; Shallice, Tim; Robinson, Gail; MacPherson, Sarah E.; Turner, Martha; Woollett, Katherine; Bozzali, Marco; Cipolotti, Lisa

2013-01-01

The proverb interpretation task (PIT) is often used in clinical settings to evaluate frontal “executive” dysfunction. However, only a relatively small number of studies have investigated the relationship between frontal lobe lesions and performance on the PIT. We compared 52 patients with unselected focal frontal lobe lesions with 52 closely matched healthy controls on a proverb interpretation task. Participants also completed a battery of neuropsychological tests, including a fluid intelligence task (Raven’s Advanced Progressive Matrices). Lesions were firstly analysed according to a standard left/right sub-division. Secondly, a finer-grained analysis compared the performance of patients with medial, left lateral and right lateral lesions with healthy controls. Thirdly, a contrast of specific frontal subgroups compared the performance of patients with medial lesions with patients with lateral frontal lesions. The results showed that patients with left frontal lesions were significantly impaired on the PIT, while in patients with right frontal lesions the impairments approached significance. Medial frontal patients were the only frontal subgroup impaired on the PIT, relative to healthy controls and lateral frontal patients. Interestingly, an error analysis indicated that a significantly higher number of concrete responses were found in the left lateral subgroup compared to healthy controls. We found no correlation between scores on the PIT and on the fluid intelligence task. Overall our results suggest that specific regions of the frontal lobes contribute to the performance on the PIT. PMID:23850600

Voxel-based morphometry in Alzheimers disease and mild cognitive impairment: Systematic review of studies addressing the frontal lobe.

PubMed

Ribeiro, Luís Gustavo; Busatto, Geraldo

2016-01-01

Voxel-based morphometry (VBM) is a useful approach for investigating neurostructural brain changes in dementia. We systematically reviewed VBM studies of Alzheimer's disease (AD) and mild cognitive impairment (MCI), specifically focusing on grey matter (GM) atrophy in the frontal lobe. Two searches were performed on the Pubmed database. A set of exclusion criteria was applied to ensure the selection of only VBM studies that directly investigated GM volume abnormalities in AD and/or MCI patients compared to cognitively normal controls. From a total of 46 selected articles, 35 VBM studies reported GM volume reductions in the frontal lobe. The frontal subregions, where most of the volume reductions were reported, included the inferior, superior and middle frontal gyri, as well as the anterior cingulate gyrus. We also found studies in which reduced frontal GM was detected in MCI patients who converted to AD. In a minority of studies, correlations between frontal GM volumes and behavioural changes or cognitive deficits in AD patients were investigated, with variable findings. Results of VBM studies indicate that the frontal lobe should be regarded as an important brain area when investigating GM volume deficits in association with AD. Frontal GM loss might not be a feature specific to late AD only. Future VBM studies involving large AD samples are warranted to further investigate correlations between frontal volume deficits and both cognitive impairment and neuropsychiatric symptoms.

Defining the Human Macula Transcriptome and Candidate Retinal Disease Genes UsingEyeSAGE

PubMed Central

Rickman, Catherine Bowes; Ebright, Jessica N.; Zavodni, Zachary J.; Yu, Ling; Wang, Tianyuan; Daiger, Stephen P.; Wistow, Graeme; Boon, Kathy; Hauser, Michael A.

2009-01-01

Purpose To develop large-scale, high-throughput annotation of the human macula transcriptome and to identify and prioritize candidate genes for inherited retinal dystrophies, based on ocular-expression profiles using serial analysis of gene expression (SAGE). Methods Two human retina and two retinal pigment epithelium (RPE)/choroid SAGE libraries made from matched macula or midperipheral retina and adjacent RPE/choroid of morphologically normal 28- to 66-year-old donors and a human central retina longSAGE library made from 41- to 66-year-old donors were generated. Their transcription profiles were entered into a relational database, EyeSAGE, including microarray expression profiles of retina and publicly available normal human tissue SAGE libraries. EyeSAGE was used to identify retina- and RPE-specific and -associated genes, and candidate genes for retina and RPE disease loci. Differential and/or cell-type specific expression was validated by quantitative and single-cell RT-PCR. Results Cone photoreceptor-associated gene expression was elevated in the macula transcription profiles. Analysis of the longSAGE retina tags enhanced tag-to-gene mapping and revealed alternatively spliced genes. Analysis of candidate gene expression tables for the identified Bardet-Biedl syndrome disease gene (BBS5) in the BBS5 disease region table yielded BBS5 as the top candidate. Compelling candidates for inherited retina diseases were identified. Conclusions The EyeSAGE database, combining three different gene-profiling platforms including the authors’ multidonor-derived retina/RPE SAGE libraries and existing single-donor retina/RPE libraries, is a powerful resource for definition of the retina and RPE transcriptomes. It can be used to identify retina-specific genes, including alternatively spliced transcripts and to prioritize candidate genes within mapped retinal disease regions. PMID:16723438

Defining the human macula transcriptome and candidate retinal disease genes using EyeSAGE.

PubMed

Bowes Rickman, Catherine; Ebright, Jessica N; Zavodni, Zachary J; Yu, Ling; Wang, Tianyuan; Daiger, Stephen P; Wistow, Graeme; Boon, Kathy; Hauser, Michael A

2006-06-01

To develop large-scale, high-throughput annotation of the human macula transcriptome and to identify and prioritize candidate genes for inherited retinal dystrophies, based on ocular-expression profiles using serial analysis of gene expression (SAGE). Two human retina and two retinal pigment epithelium (RPE)/choroid SAGE libraries made from matched macula or midperipheral retina and adjacent RPE/choroid of morphologically normal 28- to 66-year-old donors and a human central retina longSAGE library made from 41- to 66-year-old donors were generated. Their transcription profiles were entered into a relational database, EyeSAGE, including microarray expression profiles of retina and publicly available normal human tissue SAGE libraries. EyeSAGE was used to identify retina- and RPE-specific and -associated genes, and candidate genes for retina and RPE disease loci. Differential and/or cell-type specific expression was validated by quantitative and single-cell RT-PCR. Cone photoreceptor-associated gene expression was elevated in the macula transcription profiles. Analysis of the longSAGE retina tags enhanced tag-to-gene mapping and revealed alternatively spliced genes. Analysis of candidate gene expression tables for the identified Bardet-Biedl syndrome disease gene (BBS5) in the BBS5 disease region table yielded BBS5 as the top candidate. Compelling candidates for inherited retina diseases were identified. The EyeSAGE database, combining three different gene-profiling platforms including the authors' multidonor-derived retina/RPE SAGE libraries and existing single-donor retina/RPE libraries, is a powerful resource for definition of the retina and RPE transcriptomes. It can be used to identify retina-specific genes, including alternatively spliced transcripts and to prioritize candidate genes within mapped retinal disease regions.

Auditory connections and functions of prefrontal cortex

PubMed Central

Plakke, Bethany; Romanski, Lizabeth M.

2014-01-01

The functional auditory system extends from the ears to the frontal lobes with successively more complex functions occurring as one ascends the hierarchy of the nervous system. Several areas of the frontal lobe receive afferents from both early and late auditory processing regions within the temporal lobe. Afferents from the early part of the cortical auditory system, the auditory belt cortex, which are presumed to carry information regarding auditory features of sounds, project to only a few prefrontal regions and are most dense in the ventrolateral prefrontal cortex (VLPFC). In contrast, projections from the parabelt and the rostral superior temporal gyrus (STG) most likely convey more complex information and target a larger, widespread region of the prefrontal cortex. Neuronal responses reflect these anatomical projections as some prefrontal neurons exhibit responses to features in acoustic stimuli, while other neurons display task-related responses. For example, recording studies in non-human primates indicate that VLPFC is responsive to complex sounds including vocalizations and that VLPFC neurons in area 12/47 respond to sounds with similar acoustic morphology. In contrast, neuronal responses during auditory working memory involve a wider region of the prefrontal cortex. In humans, the frontal lobe is involved in auditory detection, discrimination, and working memory. Past research suggests that dorsal and ventral subregions of the prefrontal cortex process different types of information with dorsal cortex processing spatial/visual information and ventral cortex processing non-spatial/auditory information. While this is apparent in the non-human primate and in some neuroimaging studies, most research in humans indicates that specific task conditions, stimuli or previous experience may bias the recruitment of specific prefrontal regions, suggesting a more flexible role for the frontal lobe during auditory cognition. PMID:25100931

EEG-fMRI in the presurgical evaluation of temporal lobe epilepsy.

PubMed

Coan, Ana C; Chaudhary, Umair J; Frédéric Grouiller; Campos, Brunno M; Perani, Suejen; De Ciantis, Alessio; Vulliemoz, Serge; Diehl, Beate; Beltramini, Guilherme C; Carmichael, David W; Thornton, Rachel C; Covolan, Roberto J; Cendes, Fernando; Lemieux, Louis

2016-06-01

Drug-resistant temporal lobe epilepsy (TLE) often requires thorough investigation to define the epileptogenic zone for surgical treatment. We used simultaneous interictal scalp EEG-fMRI to evaluate its value for predicting long-term postsurgical outcome. 30 patients undergoing presurgical evaluation and proceeding to temporal lobe (TL) resection were studied. Interictal epileptiform discharges (IEDs) were identified on intra-MRI EEG and used to build a model of haemodynamic changes. In addition, topographic electroencephalographic correlation maps were calculated between the average IED during video-EEG and intra-MRI EEG, and used as a condition. This allowed the analysis of all data irrespective of the presence of IED on intra-MRI EEG. Mean follow-up after surgery was 46 months. International League Against Epilepsy (ILAE) outcomes 1 and 2 were considered good, and 3-6 poor, surgical outcome. Haemodynamic maps were classified according to the presence (Concordant) or absence (Discordant) of Blood Oxygen Level-Dependent (BOLD) change in the TL overlapping with the surgical resection. The proportion of patients with good surgical outcome was significantly higher (13/16; 81%) in the Concordant than in the Discordant group (3/14; 21%) (χ(2) test, Yates correction, p=0.003) and multivariate analysis showed that Concordant BOLD maps were independently related to good surgical outcome (p=0.007). Sensitivity and specificity of EEG-fMRI results to identify patients with good surgical outcome were 81% and 79%, respectively, and positive and negative predictive values were 81% and 79%, respectively. The presence of significant BOLD changes in the area of resection on interictal EEG-fMRI in patients with TLE retrospectively confirmed the epileptogenic zone. Surgical resection including regions of haemodynamic changes in the TL may lead to better postoperative outcome. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Famous face identification in temporal lobe epilepsy: Support for a multimodal integration model of semantic memory

PubMed Central

Drane, Daniel L.; Ojemann, Jeffrey G.; Phatak, Vaishali; Loring, David W.; Gross, Robert E.; Hebb, Adam O.; Silbergeld, Daniel L.; Miller, John W.; Voets, Natalie L.; Saindane, Amit M.; Barsalou, Lawrence; Meador, Kimford J.; Ojemann, George A.; Tranel, Daniel

2012-01-01

This study aims to demonstrate that the left and right anterior temporal lobes (ATLs) perform critical but unique roles in famous face identification, with damage to either leading to differing deficit patterns reflecting decreased access to lexical or semantic concepts but not their degradation. Famous face identification was studied in 22 presurgical and 14 postsurgical temporal lobe epilepsy (TLE) patients and 20 healthy comparison subjects using free recall and multiple choice (MC) paradigms. Right TLE patients exhibited presurgical deficits in famous face recognition, and postsurgical deficits in both famous face recognition and familiarity judgments. However, they did not exhibit any problems with naming before or after surgery. In contrast, left TLE patients demonstrated both pre-and postsurgical deficits in famous face naming but no significant deficits in recognition or familiarity. Double dissociations in performance between groups were alleviated by altering task demands. Postsurgical right TLE patients provided with MC options correctly identified greater than 70% of famous faces they initially rated as unfamiliar. Left TLE patients accurately chose the name for nearly all famous faces they recognized (based on their verbal description) but initially failed to name, although they tended to rapidly lose access to this name. We believe alterations in task demands activate alternative routes to semantic and lexical networks, demonstrating that unique pathways to such stored information exist, and suggesting a different role for each ATL in identifying visually presented famous faces. The right ATL appears to play a fundamental role in accessing semantic information from a visual route, with the left ATL serving to link semantic information to the language system to produce a specific name. These findings challenge several assumptions underlying amodal models of semantic memory, and provide support for the integrated multimodal theories of semantic memory and a distributed representation of concepts. PMID:23040175

Famous face identification in temporal lobe epilepsy: support for a multimodal integration model of semantic memory.

PubMed

Drane, Daniel L; Ojemann, Jeffrey G; Phatak, Vaishali; Loring, David W; Gross, Robert E; Hebb, Adam O; Silbergeld, Daniel L; Miller, John W; Voets, Natalie L; Saindane, Amit M; Barsalou, Lawrence; Meador, Kimford J; Ojemann, George A; Tranel, Daniel

2013-06-01

This study aims to demonstrate that the left and right anterior temporal lobes (ATLs) perform critical but unique roles in famous face identification, with damage to either leading to differing deficit patterns reflecting decreased access to lexical or semantic concepts but not their degradation. Famous face identification was studied in 22 presurgical and 14 postsurgical temporal lobe epilepsy (TLE) patients and 20 healthy comparison subjects using free recall and multiple choice (MC) paradigms. Right TLE patients exhibited presurgical deficits in famous face recognition, and postsurgical deficits in both famous face recognition and familiarity judgments. However, they did not exhibit any problems with naming before or after surgery. In contrast, left TLE patients demonstrated both pre- and postsurgical deficits in famous face naming but no significant deficits in recognition or familiarity. Double dissociations in performance between groups were alleviated by altering task demands. Postsurgical right TLE patients provided with MC options correctly identified greater than 70% of famous faces they initially rated as unfamiliar. Left TLE patients accurately chose the name for nearly all famous faces they recognized (based on their verbal description) but initially failed to name, although they tended to rapidly lose access to this name. We believe alterations in task demands activate alternative routes to semantic and lexical networks, demonstrating that unique pathways to such stored information exist, and suggesting a different role for each ATL in identifying visually presented famous faces. The right ATL appears to play a fundamental role in accessing semantic information from a visual route, with the left ATL serving to link semantic information to the language system to produce a specific name. These findings challenge several assumptions underlying amodal models of semantic memory, and provide support for the integrated multimodal theories of semantic memory and a distributed representation of concepts. Copyright © 2012 Elsevier Ltd. All rights reserved.

Temporal lobe surgery in childhood and neuroanatomical predictors of long-term declarative memory outcome

PubMed Central

Skirrow, Caroline; Cross, J. Helen; Harrison, Sue; Cormack, Francesca; Harkness, William; Coleman, Rosie; Meierotto, Ellen; Gaiottino, Johanna; Vargha-Khadem, Faraneh

2015-01-01

The temporal lobes play a prominent role in declarative memory function, including episodic memory (memory for events) and semantic memory (memory for facts and concepts). Surgical resection for medication-resistant and well-localized temporal lobe epilepsy has good prognosis for seizure freedom, but is linked to memory difficulties in adults, especially when the removal is on the left side. Children may benefit most from surgery, because brain plasticity may facilitate post-surgical reorganization, and seizure cessation may promote cognitive development. However, the long-term impact of this intervention in children is not known. We examined memory function in 53 children (25 males, 28 females) who were evaluated for epilepsy surgery: 42 underwent unilateral temporal lobe resections (25 left, 17 right, mean age at surgery 13.8 years), 11 were treated only pharmacologically. Average follow-up was 9 years (range 5–15). Post-surgical change in visual and verbal episodic memory, and semantic memory at follow-up were examined. Pre- and post-surgical T1-weighted MRI brain scans were analysed to extract hippocampal and resection volumes, and evaluate post-surgical temporal lobe integrity. Language lateralization indices were derived from functional magnetic resonance imaging. There were no significant pre- to postoperative decrements in memory associated with surgery. In contrast, gains in verbal episodic memory were seen after right temporal lobe surgery, and visual episodic memory improved after left temporal lobe surgery, indicating a functional release in the unoperated temporal lobe after seizure reduction or cessation. Pre- to post-surgical change in memory function was not associated with any indices of brain structure derived from MRI. However, better verbal memory at follow-up was linked to greater post-surgical residual hippocampal volumes, most robustly in left surgical participants. Better semantic memory at follow-up was associated with smaller resection volumes and greater temporal pole integrity after left temporal surgery. Results were independent of post-surgical intellectual function and language lateralization. Our findings indicate post-surgical, hemisphere-dependent material-specific improvement in memory functions in the intact temporal lobe. However, outcome was linked to the anatomical integrity of the temporal lobe memory system, indicating that compensatory mechanisms are constrained by the amount of tissue which remains in the operated temporal lobe. Careful tailoring of resections for children undergoing epilepsy surgery may enhance long-term memory outcome. PMID:25392199

The morphology, processes, and evolution of Monterey Fan: a revisit

USGS Publications Warehouse

Gardner, James V.; Bohannon, Robert G.; Field, Michael E.; Masson, Douglas G.

2010-01-01

Long-range (GLORIA) and mid-range (TOBI) sidescan imagery and seismic-reflection profiles have revealed the surface morphology and architecture of the complete Monterey Fan. The fan has not developed a classic wedge shape because it has been blocked for much of its history by Morro Fracture Zone. The barrier has caused the fan to develop an upper-fan and lower-fan sequence that are distinctly different from one another. The upper-fan sequence is characterized by Monterey and Ascension Channels and associated Monterey Channel-levee system. The lower-fan sequence is characterized by depositional lobes of the Ascension, Monterey, and Sur-Parkington-Lucia systems, with the Monterey depositional lobe being the youngest. Presently, the Monterey depositional lobe is being downcut because the system has reached a new, lower base level in the Murray Fracture Zone. A five-step evolution of Monterey Fan is presented, starting with initial fan deposition in the Late Miocene, about 5.5 Ma. This first stage was one of filling bathymetric lows in the oceanic basement in what was to become the upper-fan segment. The second stage involved filling the bathymetric low on the north side of Morro Fracture Zone, and probably not much sediment was transported beyond the fracture zone. The third stage witnessed sediment being transported around both ends of Morro Fracture Zone and initial sedimentation on the lower-fan segment. During the fourth stage Ascension Channel was diverted into Monterey Channel, thereby cutting off sedimentation to the Ascension depositional lobe.

Robotic resection of the liver caudate lobe: technical description and initial consideration.

PubMed

Marino, Marco Vito; Glagolieva, Anastasiia; Guarrasi, Domenico

2018-03-01

Firstly described in 2002, the robotic liver surgery has not spread widely due to its high cost and the lack of a standardized training program. Still being considered as a 'development in progress' technique, it has however a potential to overcome the traditional limitations of the laparoscopic approach in liver interventions. We analyzed the postoperative outcomes of 10 patients who had undergone robotic partial resection of the caudate lobe (Spiegel lobe) from March 2014 to May 2016 in order to evaluate the advantages of robotic technique in hands of a young surgeon. The mean operative time was 258min (150-522) and the estimated blood loss 137ml (50-359), in none of the cases a blood transfusion was required. No patient underwent a conversion to open surgery; the overall morbidity was 2/10 (20%) and all the complications occurred (biliary fistula and pleural effusion) did not require a surgical revision. At histological examination, the mean tumour size was 2.63cm and we achieved R0-resection rate of 100%. The 90-day mortality rate was null. The 1-year overall and disease free-survival rates were 100% and 80%, respectively. Despite several concerns regarding the cost-effectiveness, a fully robotic partial resection of caudate lobe is an advantageous, implementable technique providing promising short-term postoperative outcomes with acceptable benefit-risk profile. Copyright © 2018 AEC. Publicado por Elsevier España, S.L.U. All rights reserved.

Multivariate Pattern Analysis Reveals Category-Related Organization of Semantic Representations in Anterior Temporal Cortex.

PubMed

Malone, Patrick S; Glezer, Laurie S; Kim, Judy; Jiang, Xiong; Riesenhuber, Maximilian

2016-09-28

The neural substrates of semantic representation have been the subject of much controversy. The study of semantic representations is complicated by difficulty in disentangling perceptual and semantic influences on neural activity, as well as in identifying stimulus-driven, "bottom-up" semantic selectivity unconfounded by top-down task-related modulations. To address these challenges, we trained human subjects to associate pseudowords (TPWs) with various animal and tool categories. To decode semantic representations of these TPWs, we used multivariate pattern classification of fMRI data acquired while subjects performed a semantic oddball detection task. Crucially, the classifier was trained and tested on disjoint sets of TPWs, so that the classifier had to use the semantic information from the training set to correctly classify the test set. Animal and tool TPWs were successfully decoded based on fMRI activity in spatially distinct subregions of the left medial anterior temporal lobe (LATL). In addition, tools (but not animals) were successfully decoded from activity in the left inferior parietal lobule. The tool-selective LATL subregion showed greater functional connectivity with left inferior parietal lobule and ventral premotor cortex, indicating that each LATL subregion exhibits distinct patterns of connectivity. Our findings demonstrate category-selective organization of semantic representations in LATL into spatially distinct subregions, continuing the lateral-medial segregation of activation in posterior temporal cortex previously observed in response to images of animals and tools, respectively. Together, our results provide evidence for segregation of processing hierarchies for different classes of objects and the existence of multiple, category-specific semantic networks in the brain. The location and specificity of semantic representations in the brain are still widely debated. We trained human participants to associate specific pseudowords with various animal and tool categories, and used multivariate pattern classification of fMRI data to decode the semantic representations of the trained pseudowords. We found that: (1) animal and tool information was organized in category-selective subregions of medial left anterior temporal lobe (LATL); (2) tools, but not animals, were encoded in left inferior parietal lobe; and (3) LATL subregions exhibited distinct patterns of functional connectivity with category-related regions across cortex. Our findings suggest that semantic knowledge in LATL is organized in category-related subregions, providing evidence for the existence of multiple, category-specific semantic representations in the brain. Copyright © 2016 the authors 0270-6474/16/3610089-08$15.00/0.

Primary intrapulmonary solitary fibrous tumours

PubMed Central

Lin, Xia; Xiang, Yingming; Shi, Hongcan; Zhang, Fangbiao

2018-01-01

Due to the extreme rarity of primary intrapulmonary solitary fibrous tumours (SFTs), their clinical course, imaging characteristics, diagnosis, treatment and prognosis are poorly understood. The present study therefore assessed the diagnosis and management of primary intrapulmonary SFTs and systematically reviewed previously reported cases in the literature. A total of 5 patients who underwent resection for primary intrapulmonary SFTs were enrolled in the present study and their clinical course, tumour characteristics, management and survival were assessed in this retrospective study. Relevant studies regarding primary intrapulmonary SFTs were searched using PubMed and tumour characteristics, clinicopathologic features, therapeutic strategy and survival outcomes were reviewed. Of the 5 cases, all were males, with a mean age of 57.6 years (range, 37–68 years). All patients were asymptomatic and were identified incidentally on routine computed tomography examination. A total of 3 patients underwent thoracotomy and 2 patients underwent video-assisted thoracoscopic surgery. All tumours were completely resected. Postoperative haemorrhage occurred in 1 patient and he received surgical intervention for haemostasis. The average hospital stay was 15 (4–22) days, and no mortality occurred. The mean length of the postoperative follow-up was 37.6 (1–67) months. One patient was lost to follow-up, and 4 patients were asymptomatic. A total of 19 studies were identified from database searches. They included a total of 45 patients: Twenty-three males and 22 females (mean age, 59.4 years; range, 7–81 years). A total of 12 patients were asymptomatic, and pain and coughing were the major symptoms. Five, one, two, four, and 17 tumours occurred in the right upper lobe, right middle lobe, right lower lobe, left upper lobe and left lower lobe, respectively. A total of 39 patients underwent surgery, 1 patient underwent radiotherapy, and 1 patient underwent radiofrequency ablation. A total of 22 patients were followed up and the mean length of the postoperative follow-up was 48 (1–168) months. One patient was diagnosed with chest wall metastases, and 5 patients succumbed to mortality. To conclude, primary intrapulmonary SFTs are extremely rare and typically identified incidentally. The present findings indicated that the left lower lobe was the most common site location and complete surgical resection is a safe and effective treatment. PMID:29467886

Deep Proteome Profiling Reveals Common Prevalence of MZB1-Positive Plasma B Cells in Human Lung and Skin Fibrosis.

PubMed

Schiller, Herbert B; Mayr, Christoph H; Leuschner, Gabriela; Strunz, Maximilian; Staab-Weijnitz, Claudia; Preisendörfer, Stefan; Eckes, Beate; Moinzadeh, Pia; Krieg, Thomas; Schwartz, David A; Hatz, Rudolf A; Behr, Jürgen; Mann, Matthias; Eickelberg, Oliver

2017-11-15

Analyzing the molecular heterogeneity of different forms of organ fibrosis may reveal common and specific factors and thus identify potential future therapeutic targets. We sought to use proteome-wide profiling of human tissue fibrosis to (1) identify common and specific signatures across end-stage interstitial lung disease (ILD) cases, (2) characterize ILD subgroups in an unbiased fashion, and (3) identify common and specific features of lung and skin fibrosis. We collected samples of ILD tissue (n = 45) and healthy donor control samples (n = 10), as well as fibrotic skin lesions from localized scleroderma and uninvolved skin (n = 6). Samples were profiled by quantitative label-free mass spectrometry, Western blotting, or confocal imaging. We determined the abundance of more than 7,900 proteins and stratified these proteins according to their detergent solubility profiles. Common protein regulations across all ILD cases, as well as distinct ILD subsets, were observed. Proteomic comparison of lung and skin fibrosis identified a common upregulation of marginal zone B- and B1-cell-specific protein (MZB1), the expression of which identified MZB1 + /CD38 + /CD138 + /CD27 + /CD45 - /CD20 - plasma B cells in fibrotic lung and skin tissue. MZB1 levels correlated positively with tissue IgG and negatively with diffusing capacity of the lung for carbon monoxide. Despite the presumably high molecular and cellular heterogeneity of ILD, common protein regulations are observed, even across organ boundaries. The surprisingly high prevalence of MZB1-positive plasma B cells in tissue fibrosis warrants future investigations regarding the causative role of antibody-mediated autoimmunity in idiopathic cases of organ fibrosis, such as idiopathic pulmonary fibrosis.

A new method for finding and characterizing galaxy groups via low-frequency radio surveys

NASA Astrophysics Data System (ADS)

Croston, J. H.; Ineson, J.; Hardcastle, M. J.; Mingo, B.

2017-09-01

We describe a new method for identifying and characterizing the thermodynamic state of large samples of evolved galaxy groups at high redshifts using high-resolution, low-frequency radio surveys, such as those that will be carried out with LOFAR and the Square Kilometre Array. We identify a sub-population of morphologically regular powerful [Fanaroff-Riley type II (FR II)] radio galaxies and demonstrate that, for this sub-population, the internal pressure of the radio lobes is a reliable tracer of the external intragroup/intracluster medium (ICM) pressure, and that the assumption of a universal pressure profile for relaxed groups enables the total mass and X-ray luminosity to be estimated. Using a sample of well-studied FR II radio galaxies, we demonstrate that our method enables the estimation of group/cluster X-ray luminosities over three orders of magnitude in luminosity to within a factor of ˜2 from low-frequency radio properties alone. Our method could provide a powerful new tool for building samples of thousands of evolved galaxy groups at z > 1 and characterizing their ICM.

True memory, false memory, and subjective recollection deficits after focal parietal lobe lesions.

PubMed

Drowos, David B; Berryhill, Marian; André, Jessica M; Olson, Ingrid R

2010-07-01

There is mounting evidence that the posterior parietal cortex (PPC) plays an important role in episodic memory. We previously found that patients with PPC damage exhibit retrieval-related episodic memory deficits. Here we assess whether parietal lobe damage affects episodic memory on a different task: the Deese-Roediger-McDermott (DRM) false-memory paradigm. Two patients with bilateral PPC damage and a group of matched controls were tested. In Experiment 1, the task was to remember words; in Experiment 2 the task was to remember pictures of common objects. Prior studies have shown that normal participants have high levels of false memory to words, low levels to pictures. The patients exhibited significantly lower levels of false memory to words. One patient showed significantly elevated levels of false memory to pictures. The patients' false memories were accompanied by reduced levels of recollection, as tested by a Remember/Know procedure. PPC damage causes decreased levels of false memories and an abnormal Remember/Know profile. Their false memory rate is similar to the rate exhibited by patients with medial temporal lobe damage. These results support the view that portions of the PPC play a critical role in objective and subjective aspects of recollection.

Implementation of the 3D edge plasma code EMC3-EIRENE on NSTX

DOE PAGES

Lore, J. D.; Canik, J. M.; Feng, Y.; ...

2012-05-09

The 3D edge transport code EMC3-EIRENE has been applied for the first time to the NSTX spherical tokamak. A new disconnected double null grid has been developed to allow the simulation of plasma where the radial separation of the inner and outer separatrix is less than characteristic widths (e.g. heat flux width) at the midplane. Modelling results are presented for both an axisymmetric case and a case where 3D magnetic field is applied in an n = 3 configuration. In the vacuum approximation, the perturbed field consists of a wide region of destroyed flux surfaces and helical lobes which aremore » a mixture of long and short connection length field lines formed by the separatrix manifolds. This structure is reflected in coupled 3D plasma fluid (EMC3) and kinetic neutral particle (EIRENE) simulations. The helical lobes extending inside of the unperturbed separatrix are filled in by hot plasma from the core. The intersection of the lobes with the divertor results in a striated flux footprint pattern on the target plates. As a result, profiles of divertor heat and particle fluxes are compared with experimental data, and possible sources of discrepancy are discussed.« less

Ex vivo MRI transverse relaxation in community based older persons with and without Alzheimer's dementia.

PubMed

Yu, Lei; Dawe, Robert J; Buchman, Aron S; Boyle, Patricia A; Schneider, Julie A; Arfanakis, Konstantinos; Bennett, David A

2017-03-30

Alterations of the transverse relaxation rate, R 2 , measured using MRI, are observed in older persons with Alzheimer's (AD) dementia. However, the spatial pattern of these alterations and the degree to which they reflect the accumulation of common age-related neuropathologies are unknown. In this study, we characterized the profile of R 2 alterations in post-mortem brains of persons with clinical diagnosis of AD dementia and investigated how the profile differs after accounting for neuropathologic indices of AD, cerebral infarcts, Lewy body disease, hippocampal sclerosis and transactive response DNA-binding protein 43. Data came from 567 post-mortem brains donated by participants in two cohort studies of aging and dementia. R 2 was quantified using fast spin echo imaging. Voxelwise linear regression examined R 2 alterations between subjects diagnosed with AD dementia at death and those with no cognitive impairment. Voxels showing significant R 2 alterations were clustered into regions of interest (ROIs). Three R 2 profiles were compared, which were adjusted for (1) demographics only; (2) demographics and AD pathology; (3) demographics, AD pathology and other common neuropathologies. R 2 alterations were observed throughout the hemisphere, most commonly in white matter. Of the distinct ROIs identified, the largest region encompassed large portions of white matter in all lobes. This ROI became smaller in size but remained largely intact after adjusting for AD and other neuropathologic indices. Further, R 2 alterations identify AD dementia with improved accuracy, above and beyond demographics and neuropathologic indices (p<0.0001). In conclusion, R 2 alterations in AD dementia are not solely reflective of common age-related neuropathologies, suggesting that other mechanisms are at work. Copyright © 2016 Elsevier B.V. All rights reserved.

The Role of Fine Needle Aspiration in the Diagnosis of Parotid Gland Tumors: Correlation With Preoperative Computerized Tomography Tumor Size.

PubMed

Ghantous, Yasmine; Naddaf, Raja; Barak, Michal; Abd-Elraziq, Murad; Abu Eln-Naaj, Imad

2016-03-01

The role of fine needle aspiration cytology (FNAC) in the diagnosis of parotid gland masses is still controversial, regarding its sensitivity and specificity that vary between 41% and 100% and between 86% and 100% respectively.The aim of this study was to identify the specificity and sensitivity of FNAC of parotid gland tumors in relation to the tumor size as characterized preoperatively by computer tomography. The medical files of 79 patients whom were referred to the MaxilloFacila Surgery Department, Rambam medical center, over a 10.5-year period (2000-2010) were analyzed retrospectively.The extensity of the operation was determined by the location of the tumor as presented in computed tomography (CT) radiography, and preoperative FNAC examination.The majority of the masses were located in the superficial lobe (88.52%), and only 11.48% of the patients were located in the deep lobe (8:1 ratio). FNAC results were nondiagnostic in 7 patients (8.86%), 62 patients were diagnosed as inflammatory and benign lesion in (78.48%), malignant tumors were diagnosed in 10 patients (12.65%).The sensitivity in our study was 90%, the specificity was 98%, positive predictive value was 90%, negative predictive value was 98%, and diagnostic accuracy was 88%. The positive predictive value was 90%, the negative predictive value was 98%.Analyzing the effect of the preoperative CT size upon the accuracy of the FNAC diagnosis, we found that lesion with preoperative CT size greater than 24 mm has a more accurate FNAC result (P = 0.034).

Animacy and real-world size shape object representations in the human medial temporal lobes.

PubMed

Blumenthal, Anna; Stojanoski, Bobby; Martin, Chris B; Cusack, Rhodri; Köhler, Stefan

2018-06-26

Identifying what an object is, and whether an object has been encountered before, is a crucial aspect of human behavior. Despite this importance, we do not yet have a complete understanding of the neural basis of these abilities. Investigations into the neural organization of human object representations have revealed category specific organization in the ventral visual stream in perceptual tasks. Interestingly, these categories fall within broader domains of organization, with reported distinctions between animate, inanimate large, and inanimate small objects. While there is some evidence for category specific effects in the medial temporal lobe (MTL), in particular in perirhinal and parahippocampal cortex, it is currently unclear whether domain level organization is also present across these structures. To this end, we used fMRI with a continuous recognition memory task. Stimuli were images of objects from several different categories, which were either animate or inanimate, or large or small within the inanimate domain. We employed representational similarity analysis (RSA) to test the hypothesis that object-evoked responses in MTL structures during recognition-memory judgments also show evidence for domain-level organization along both dimensions. Our data support this hypothesis. Specifically, object representations were shaped by either animacy, real-world size, or both, in perirhinal and parahippocampal cortex, and the hippocampus. While sensitivity to these dimensions differed across structures when probed individually, hinting at interesting links to functional differentiation, similarities in organization across MTL structures were more prominent overall. These results argue for continuity in the organization of object representations in the ventral visual stream and the MTL. © 2018 Wiley Periodicals, Inc.

Common and unique gray matter correlates of episodic memory dysfunction in frontotemporal dementia and Alzheimer's disease.

PubMed

Irish, Muireann; Piguet, Olivier; Hodges, John R; Hornberger, Michael

2014-04-01

Conflicting evidence exists regarding the integrity of episodic memory in the behavioral variant of frontotemporal dementia (bvFTD). Recent converging evidence suggests that episodic memory in progressive cases of bvFTD is compromised to the same extent as in Alzheimer's disease (AD). The underlying neural substrates of these episodic memory deficits, however, likely differ contingent on dementia type. In this study we sought to elucidate the neural substrates of episodic memory performance, across recall and recognition tasks, in both patient groups using voxel-based morphometry (VBM) analyses. We predicted that episodic memory dysfunction would be apparent in both patient groups but would relate to divergent patterns of neural atrophy specific to each dementia type. We assessed episodic memory, across verbal and visual domains, in 19 bvFTD, 18 AD patients, and 19 age- and education-matched controls. Behaviorally, patient groups were indistinguishable for immediate and delayed recall, across verbal and visual domains. Whole-brain VBM analyses revealed regions commonly implicated in episodic retrieval across groups, namely the right temporal pole, right frontal lobe, left paracingulate gyrus, and right anterior hippocampus. Divergent neural networks specific to each group were also identified. Whereas a widespread network including posterior regions such as the posterior cingulate cortex, parietal and occipital cortices was exclusively implicated in AD, the frontal and anterior temporal lobes underpinned the episodic memory deficits in bvFTD. Our results point to distinct neural changes underlying episodic memory decline specific to each dementia syndrome. Copyright © 2013 Wiley Periodicals, Inc.

Isomer-specific profiling of N-glycans derived from human serum for potential biomarker discovery in pancreatic cancer.

PubMed

Liu, Yufei; Wang, Chang; Wang, Ran; Wu, Yike; Zhang, Liang; Liu, Bi-Feng; Cheng, Liming; Liu, Xin

2018-06-15

Glycosylation is one of the most important post-translational modifications of protein. Recently, global profiling of human serum glycomics has become a noninvasive method for cancer-related biomarker discovery and many studies have focused on compositional glycan profiling. In contrast, structure-specific glycan profiling may provide more potential biomarkers with higher specificity than compositional profiling. In this work, N-glycans released from human serum were neutralized with methylamine and reduced by ammonia-borane complex prior to profiling using nanoLC-ESI-MS with porous graphitized carbon (PGC) and relative abundances of over 280 isomers were compared between pancreatic cancer (PC) cases (n = 32) and healthy controls (n = 32). Statistical analysis identified 25 specific-isomeric biomarkers with significant differences (p-value < 0.05). ROC and PCA analysis were performed to assess the potential biomarkers which were identified as being significantly altered in cancer. The AUCs of the significantly changed specific-isomers were ranging from 0.712 to 0.949. In addition, with the combination of all potential biomarkers, a higher AUC of 0.976 with sensitivity (93.5%) and specificity (90.6%) was obtained. Overall, the proposed strategy coupled to relative quantitative analysis of isomeric glycans make it possible to discover new biomarkers for the diagnosis of PC. Pancreatic cancer (PC) has a poor prognosis with a five-year survival rate <5%. Therefore, a strategy for accurate diagnosis of PC is indeed required. In this paper, a dual-derivatized strategy for structure-specific glycan profiling has been used and according to our best knowledge, this is the first application of this strategy for PC biomarker discovery, in which the separation, identification and relative quantification of isomeric glycans can be simultaneously obtained. In addition, by in-depth analysis of isomeric glycans, the full description of the stereo- and region- diversity of glycans can also be achieved, which might provide more potential information for PC biomarker discovery. Copyright © 2018 Elsevier B.V. All rights reserved.

Generation of scalable terahertz radiation from cylindrically focused two-color laser pulses in air

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kuk, D.; Yoo, Y. J.; Rosenthal, E. W.

2016-03-21

We demonstrate scalable terahertz (THz) generation by focusing terawatt, two-color laser pulses in air with a cylindrical lens. This focusing geometry creates a two-dimensional air plasma sheet, which yields two diverging THz lobe profiles in the far field. This setup can avoid plasma-induced laser defocusing and subsequent THz saturation, previously observed with spherical lens focusing of high-power laser pulses. By expanding the plasma source into a two-dimensional sheet, cylindrical focusing can lead to scalable THz generation. This scheme provides an energy conversion efficiency of 7 × 10{sup −4}, ∼7 times better than spherical lens focusing. The diverging THz lobes are refocused withmore » a combination of cylindrical and parabolic mirrors to produce strong THz fields (>21 MV/cm) at the focal point.« less

3 Tesla proton MRI for the diagnosis of pneumonia/lung infiltrates in neutropenic patients with acute myeloid leukemia: initial results in comparison to HRCT.

PubMed

Attenberger, U I; Morelli, J N; Henzler, T; Buchheidt, D; Fink, C; Schoenberg, S O; Reichert, M

2014-01-01

To evaluate the diagnostic accuracy of 3 Tesla proton MRI for the assessment of pneumonia/lung infiltrates in neutropenic patients with acute myeloid leukemia. In a prospective study, 3 Tesla MRI was performed in 19 febrile neutropenic patients (5 women, 14 men; mean age 61 years ± 14.2; range 23-77 years). All patients underwent high-resolution CT less than 24h prior to MRI. The MRI protocol (Magnetom Tim Trio, Siemens) included a T2-weighted HASTE sequence (TE/TR: 49 ms/∞, slice thickness 6mm) and a high-resolution 3D VIBE sequence with an ultra-short TE<1 ms (TE/TR 0.8/2.9 ms, slice thickness 2mm). The VIBE sequence was examined before and after intravenous injection of 0.1 mmol/kg gadoterate meglumine (Dotarem, Guerbet). The presence of pulmonary abnormalities, their location within the lung, and lesion type (nodules, consolidations, glass opacity areas) were analyzed by one reader and compared to the findings of HRCT, which was evaluated by a second independent radiologist who served as the reference standard. The findings were compared per lobe in each patient and rated as true positive (TP) findings if all three characteristics (presence, location, and lesion type) listed above were concordant to HRCT. Pulmonary abnormalities were characterized by 3 Tesla MRI with a sensitivity of 82.3% and a specificity of 78.6%, resulting in an overall accuracy of 88% (NPV/PPV 66.7%/89.5%). In 51 lobes (19 of 19 patients), pulmonary abnormalities visualized by MR were judged to be concordant in their location and in the lesion type identified by both readers. In 22 lobes (11 of 19 patients), no abnormalities were present on either MR or HRCT (true negative). In 6 lobes (5 of 19 patients), ground glass opacity areas were detected on MRI but were not visible on HRCT (false positives). In 11 lobes (7 of 19 patients), MRI failed to detect ground glass opacity areas identified by HRCT. However, since the abnormalities were disseminated in these patients, accurate treatment decisions were possible in every case based on MRI. In one case MRI showed a central area of cavitation, which was not visualized by HRCT. Infectious nodules and consolidations can be detected in neutropenic patients with acute myeloid leukemia with a sufficient diagnostic accuracy by 3 Tesla MRI. Detection of ground glass opacity areas is the main limitation of 3-Tesla MRI when compared to HRCT. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

A Comprehensive Approach to Sequence-oriented IsomiR annotation (CASMIR): demonstration with IsomiR profiling in colorectal neoplasia.

PubMed

Wu, Chung Wah; Evans, Jared M; Huang, Shengbing; Mahoney, Douglas W; Dukek, Brian A; Taylor, William R; Yab, Tracy C; Smyrk, Thomas C; Jen, Jin; Kisiel, John B; Ahlquist, David A

2018-05-25

MicroRNA (miRNA) profiling is an important step in studying biological associations and identifying marker candidates. miRNA exists in isoforms, called isomiRs, which may exhibit distinct properties. With conventional profiling methods, limitations in assay and analysis platforms may compromise isomiR interrogation. We introduce a comprehensive approach to sequence-oriented isomiR annotation (CASMIR) to allow unbiased identification of global isomiRs from small RNA sequencing data. In this approach, small RNA reads are maintained as independent sequences instead of being summarized under miRNA names. IsomiR features are identified through step-wise local alignment against canonical forms and precursor sequences. Through customizing the reference database, CASMIR is applicable to isomiR annotation across species. To demonstrate its application, we investigated isomiR profiles in normal and neoplastic human colorectal epithelia. We also ran miRDeep2, a popular miRNA analysis algorithm to validate isomiRs annotated by CASMIR. With CASMIR, specific and biologically relevant isomiR patterns could be identified. We note that specific isomiRs are often more abundant than their canonical forms. We identify isomiRs that are commonly up-regulated in both colorectal cancer and advanced adenoma, and illustrate advantages in targeting isomiRs as potential biomarkers over canonical forms. Studying miRNAs at the isomiR level could reveal new insight into miRNA biology and inform assay design for specific isomiRs. CASMIR facilitates comprehensive annotation of isomiR features in small RNA sequencing data for isomiR profiling and differential expression analysis.

Cognitive consequences of coexisting temporal lobe developmental malformations and hippocampal sclerosis.

PubMed

Martin, R; Dowler, R; Gilliam, F; Faught, E; Morawetz, R; Kuzniecky, R

1999-09-11

To characterize patterns of cognitive functioning in a well-defined group of patients with MRI-identified coexisting left temporal lobe developmental malformations (TLDM) and mesial temporal sclerosis (MTS), and to examine neuropsychological outcome in this dual-pathology group following epilepsy surgery. Cognitive functioning in patients with left TLDM and MTS (n = 15) was compared with patients with isolated left MTS (n = 40). TLDM and MTS were identified by high-quality MRI protocol. Patients were administered a battery of neuropsychology tests as part of their presurgical workup for possible epilepsy surgery. Unilateral temporal lobe resection was performed on 10 of the dual-pathology patients and 34 of the isolated MTS patients. Postoperative cognitive performance was also assessed. Both groups displayed impairments in verbal and visual memory, language, and academic achievement. Performance on measures of psychometric intelligence, executive function, and attention were not impaired and were similar between groups. Presence of dual pathology was associated with a significantly less efficient verbal encoding strategy on the word list learning task. Postoperatively, declines were noted for both groups across tasks of verbal memory and language. Groups were not different significantly in terms of neuropsychological outcome after surgery. Patients with coexisting TLDM and MTS have impaired cognitive functioning similar to MTS patients-in particular, with regard to episodic memory and language deficits. Temporal lobe resection produces similar cognitive changes in both groups.

[Local brain activity in different motor subtypes of Parkinson's disease with fMRI].

PubMed

Hou, Ya'nan; Zhang, Jiarong; Chen, Biao; Wu, Tao

2015-02-17

To explore the changes of local brain activity in motor subtypes of Parkinson's disease (PD) with functional magnetic resonance imaging (fMRI). A total of 60 idiopathic PD and 30 age- and gender-matched normal controls were examined with resting-state fMRI from January 2013 to March 2014. All subjects gave their written informed consent for the study. The amplitude of low-frequency fluctuation (ALFF) was calculated to measure local brain activity. The PD patients were divided into two groups of tremor dominant (TD) and postural instability/gait difficulty (PIGD) (n = 30 each). All subjects gave their written in formed consent for the study.One-way ANOVA and post-hoc t-test were performed to detect the differences of local brain activity between PD and normal subjects. And the correlations were examined between ALFF, scores and levodopa dose. Compared with normal subjects, the TD group showed increased activity in bilateral cerebellums (-37, -47, -38), thalamus (-18, -17,0), pons (-3, -23, -37) and left precentral gyrus (-41, -30, 46) versus decreased activity in bilateral frontal lobes (-13, 69, 6), temporal lobes (-42, 18, -21), left insula (-32, 22, 2) and left anterior cingulated (-7, 32, -5). The PIGD group showed increased activity in right postcentral gyrus (63, -18, 39) and decreased activity in bilateral putamens (-24, 12, 3), pre-supplementary motor area (10, 10, 58), frontal lobes (15, -15, 57), temporal lobes (-39, 18, -3) and left insula (-29, 20, 11). Compared with PIGD, the TD group showed increased activity in temporal lobes, but decreased activity in frontal lobes. Additionally, ALFF in bilateral cerebellums and frontal lobes was positively correlated with TD scores while ALFF in left precentral gyrus, bilateral putamens and temporal lobes negatively correlated with TD scores. ALFF in bilateral frontal lobes and left temporal lobe was positively correlated with PIGD scores.However, in right postcentral gyrus and bilateral putamens, ALFF was negatively correlated with PIGD scores. The levodopa dose was positively correlated with frontal lobes and temporal lobe in TD and cerebellums and inferior parietal lobule in PIGD. A specific pattern of intrinsic activity in TD and PIGD may provide insights into neurophysiological mechanisms of PD motor subtypes. The changes of brain activity in TD are caused by the interaction between cerebello-thalamo-cortical circuit and basal ganglia loop while the changes in PIGD result largely from damaged basal ganglia loop.

Phased Array Theory and Technology

DTIC Science & Technology

1981-07-01

Generalized Array Coordinates 2. Linear, Planar and Circular Art -ays 3. Periodic fwo Dimensional ^rras 4. Grating Lobe Lattices 5. 1’llenienl...formal and low profile antennas, antennas for limited sector coverage, and wide- band array feeds. To aid designers, there is an attempt to give ...ol Vol. 2, Elliott gives convenient formulas lor the directivity of Imear dipole arrays, and derives an especially simple form tor arrays

Identity Profiles in Lesbian, Gay, and Bisexual Youth: The Role of Family Influences

PubMed Central

Bregman, Hallie R.; Malik, Neena M.; Page, Matthew J. L.; Makynen, Emily; Lindahl, Kristin M.

2012-01-01

Sexual identity development is a central task of adolescence and young adulthood and can be especially challenging for sexual minority youth. Recent research has moved from a stage model of identity development in lesbian, gay, and bisexual (LGB) youth to examining identity in a non-linear, multidimensional manner. In addition, although families have been identified as important to youth's identity development, limited research has examined the influence of parental responses to youth's disclosure of their LGB sexual orientation on LGB identity. The current study examined a multidimensional model of LGB identity and its links with parental support and rejection. One hundred and sixty-nine LGB adolescents and young adults (ages 14–24, 56% male, 48% gay, 31% lesbian, 21% bisexual) described themselves on dimensions of LGB identity and reported on parental rejection, sexuality-specific social support, and non-sexuality-specific social support. Using latent profile analysis (LPA), two profiles were identified, indicating that youth experience both affirmed and struggling identities. Results indicated that parental rejection and sexuality-specific social support from families were salient links to LGB identity profile classification, while non-sexuality specific social support was unrelated. Parental rejection and sexuality-specific social support may be important to target in interventions for families to foster affirmed LGB identity development in youth. PMID:22847752

Exuberant and inhibited children: Person-centered profiles and links to social adjustment.

PubMed

Dollar, Jessica M; Stifter, Cynthia A; Buss, Kristin A

2017-07-01

The current study aimed to substantiate and extend our understanding regarding the existence and developmental pathways of 3 distinct temperament profiles-exuberant, inhibited, and average approach-in a sample of 3.5-year-old children (n = 121). The interactions between temperamental styles and specific types of effortful control, inhibitory control and attentional control, were also examined in predicting kindergarten peer acceptance. Latent profile analysis identified 3 temperamental styles: exuberant, inhibited, and average approach. Support was found for the adaptive role of inhibitory control for exuberant children and attentional control for inhibited children in promoting peer acceptance in kindergarten. These findings add to our current understanding of temperamental profiles by using sophisticated methodology in a slightly older, community sample, as well as the importance of examining specific types of self-regulation to identify which skills lower risk for children of different temperamental styles. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Volcanic ash leachate compositions and assessment of health and agricultural hazards from 2012 hydrothermal eruptions, Tongariro, New Zealand

NASA Astrophysics Data System (ADS)

Cronin, S. J.; Stewart, C.; Zernack, A. V.; Brenna, M.; Procter, J. N.; Pardo, N.; Christenson, B.; Wilson, T.; Stewart, R. B.; Irwin, M.

2014-10-01

After almost 80 years of quiescence, the upper Te Maari vent on Mt. Tongariro erupted suddenly at 2352 h (NZ time) on 6 August 2012. The short-lived hydrothermal eruption distributed a fine ash of minor volume (~ 5 × 105 m3) over 200 km from source. The threat of further eruptions prompted an investigation of the possible health and agricultural impacts of any future eruptions from this volcano, particularly since the most recent large-scale ash falls in New Zealand in 1995-1996 had generated significant agricultural problems, including livestock deaths. Deposited ash was sampled between 5 and 200 km from the volcano as soon as possible after the eruption. Two sub-lobes of ash were identified from different vent areas and displayed subtly different leaching properties. The first was an initial small lobe directed NNE, likely formed from drifting low-level clouds associated with the initial lateral explosive blast and surges. The main fall lobe, directed eastward, was sourced from a short-lived vertical plume that rose up to c. 8 km. Ash from the initial fall lobe had higher concentrations of F and Al, in single-step leaches as well as in the totals of three, sequential extractions. Further, the initial lobe showed a higher proportion of soluble F and Al extracted in the first leach, compared to totals. A linear relationship between concentrations of Al and F in single leaches from the 6 August eruption was highly significant (Pearson correlation coefficient r = 0.987 for 1:20 leaching ratios and r = 0.971 for 1:100), suggesting the presence of soluble alumino-fluoride complexes (AlFx+ 3 - x). An even more significant 1:1 ratio is displayed for the largest concentration leached ions of Ca and SO4, which correspond to the presence of crystalline gypsum throughout the newly excavated hydrothermal system. Although no fresh magma was erupted in this event, a shallow intrusion prior to the hydrothermal explosion apparently provided significant contents of volcanic gas that was dissolved within the hydrothermal fluids and adhering to ejected particles. This and the ubiquitous presence of gypsum dominated the soluble components of these ash deposits leading to a complex leaching profile. The leaching study carried out here showed that agricultural and human health hazard assessment (particularly of F and S) is not straightforward, particularly because F solubility may be complex and not well characterised by simple leaching studies. In the case of S, which is agriculturally important, saturation effects are apparent using normal leaching protocols and also imply a need for modification of standard methods.

[Thin-section computed tomography of the bronchi; 2. Right upper lobe and left upper division].

PubMed

Matsuoka, Y; Ookubo, T; Ohtomo, K; Nishikawa, J; Kojima, K; Oyama, K; Yoshikawa, K; Iio, M

1990-02-01

Thin (2mm) section contiguous computed tomographic (CT) scans were obtained through the bronchi of the right upper lobe and the left upper division in 30 patients. All segmental bronchi were identified. The right subsegmental bronchi were identified in 100%, and the left subsegmental bronchi in 97%. The type of the orifice of the right bronchus was trifurcated (53%), the extension of B1 was apicoanterior (50%), and the size of B2b was equal to B3a (63%). The extension of the left B3 was subapicoanterior (38%), and the size of B1+2c was equal to B3a (62%).

Submarine landslides in the Santa Barbara Channel as potential tsunami sources

USGS Publications Warehouse

Greene, H. Gary; Murai, L.Y.; Watts, P.; Maher, N.A.; Fisher, M.A.; Paull, C.E.; Eichhubl, P.

2006-01-01

Recent investigations using the Monterey Bay Aquarium Research Institutes (MBARI) Remotely Operated Vehicles (ROVs) "Ventana" and "Tiburon" and interpretation of MBARI's EM 300 30 kHz multibeam bathymetric data show that the northern flank of the Santa Barbara Basin has experienced massive slope failures. Of particular concern is the large (130 km2) Goleta landslide complex located off Coal Oil Point near the town of Goleta, that measures 14.6-km long extending from a depth of 90 m to nearly 574 m deep and is 10.5 km wide. We estimate that approximately 1.75 km3 has been displaced by this slide during the Holocene. This feature is a complex compound submarine landslide that contains both surfical slump blocks and mud flows in three distinct segments. Each segment is composed of a distinct head scarp, down-dropped head block and a slide debris lobe. The debris lobes exhibit hummocky topography in the central areas that appear to result from compression during down slope movement. The toes of the western and eastern lobes are well defined in the multibeam image, whereas the toe of the central lobe is less distinct. Continuous seismic reflection profiles show that many buried slide debris lobes exist and comparison of the deformed reflectors with ODP Drill Site 149, Hole 893 suggest that at least 200 000 years of failure have occurred in the area (Fisher et al., 2005a). Based on our interpretation of the multibeam bathymetry and seismic reflection profiles we modeled the potential tsunami that may have been produced from one of the three surfical lobes of the Goleta slide. This model shows that a 10 m high wave could have run ashore along the cliffs of the Goleta shoreline. Several other smaller (2 km2 and 4 km2) slides are located on the northern flank of the Santa Barbara Basin, both to the west and east of Goleta slide and on the Concepcion fan along the western flank of the basin. One slide, named the Gaviota slide, is 3.8 km2, 2.6 km long and 1.7 km wide. A distinct narrow scar extends from near the eastern head wall of this slide for over 2 km eastward toward the Goleta slide and may represent either an incipient failure or a remnant of a previous failure. Push cores collected within the main head scar of this slide consisted of hydrogen sulfide bearing mud, possibly suggesting active fluid seepage and a vibra-core penetrated ???50 cm of recent sediment overlying colluvium or landslide debris confirming the age of ???300 years as proposed by Lee et al. (2004). However, no seeps or indications of recent movement were observed during our ROV investigation within this narrow head scar indicating that seafloor in the scar is draped with mud. ?? 2006 Author(s). This work is licensed under a Creative Commons License.

Subcellular proteome profiles of different latex fractions revealed washed solutions from rubber particles contain crucial enzymes for natural rubber biosynthesis.

PubMed

Wang, Dan; Sun, Yong; Chang, Lili; Tong, Zheng; Xie, Quanliang; Jin, Xiang; Zhu, Liping; He, Peng; Li, Hongbin; Wang, Xuchu

2018-06-30

Rubber particle (RP) is a specific organelle for natural rubber biosynthesis (NRB) and storage in rubber tree Hevea brasiliensis. NRB is processed by RP membrane-localized proteins, which were traditionally purified by repeated washing. However, we noticed many proteins in the discarded washing solutions (WS) from RP. Here, we compared the proteome profiles of WS, C-serum (CS) and RP by 2-DE, and identified 233 abundant proteins from WS by mass spectrometry. Many spots on 2-DE gels were identified as different protein species. We further performed shotgun analysis of CS, WS and RP and identified 1837, 1799 and 1020 unique proteins, respectively. Together with 2-DE, we finally identified 1825 proteins from WS, 246 were WS-specific. These WS-specific proteins were annotated in Gene Ontology, indicating most abundant pathways are organic substance metabolic process, protein degradation, primary metabolic process, and energy metabolism. Protein-protein interaction analysis revealed these WS-specific proteins are mainly involved in ribosomal metabolism, proteasome system, vacuolar protein sorting and endocytosis. Label free and Western blotting revealed many WS-specific proteins and protein complexes are crucial for NRB initiation. These findings not only deepen our understanding of WS proteome, but also provide new evidences on the roles of RP membrane proteins in NRB. Natural rubber is stored in rubber particle from the rubber tree. Rubber particles were traditionally purified by repeated washing, but many proteins were identified from the washing solutions (WS). We obtained the first visualization proteome profiles with 1825 proteins from WS, including 246 WS-specific ones. These WS proteins contain almost all enzymes for polyisoprene initiation and may play important roles in rubber biosynthesis. Copyright © 2018 Elsevier B.V. All rights reserved.

Hippocampal hypometabolism in older adults with memory complaints and increased amyloid burden.

PubMed

Vannini, Patrizia; Hanseeuw, Bernard; Munro, Catherine E; Amariglio, Rebecca E; Marshall, Gad A; Rentz, Dorene M; Pascual-Leone, Alvaro; Johnson, Keith A; Sperling, Reisa A

2017-05-02

To identify the functional and pathologic correlates underlying subjective memory complaints (SMCs) in cognitively normal older adults. Two hundred fifty-one older adults underwent resting-state fluorodeoxyglucose (FDG)-PET and Pittsburg compound B-PET β-amyloid (Aβ) imaging and filled out a questionnaire regarding SMCs. Participants were classified into 2 groups based on their Aβ burden. Age-adjusted voxel-wise correlations were used to examine SMCs, amyloid status (Aβ + vs Aβ - ), and the interaction between SMCs and Aβ status as predictors of metabolism. Region-of-interest (ROI) analyses were performed to confirm the whole-brain analyses and to test for additional covariates. Greater SMCs correlated with decreased FDG metabolism in the bilateral precuneus, bilateral inferior parietal lobes, right inferior temporal lobe, right medial frontal gyrus, and right orbitofrontal gyrus. A significant interaction effect between SMCs and amyloid burden was found such that Aβ + individuals with increased complaints had decreased FDG metabolism in the bilateral medial temporal lobes. ROI analyses confirmed the voxel-wise analyses result in that decreased precuneus metabolism was associated with greater SMCs regardless of Aβ status, age, or thickness, whereas the relationship between hippocampal metabolism and SMCs was a function of Aβ, even after adjustment for age, hippocampal volume, or depressive symptoms. These data show the relevant role of posterior and anterior midline regions in SMCs in older individuals. Decreased hippocampal metabolism may be a specific marker of subclinical changes in cognition due to amyloid pathology. However, longitudinal studies are needed to determine whether our findings foreshadow clinical decline. © 2017 American Academy of Neurology.

NMR spectroscopy of the ligand binding core of ionotropic glutamate receptor 2 bound to 5-substituted willardiine partial agonists

PubMed Central

Fenwick, Michael K.; Oswald, Robert E.

2008-01-01

Glutamate receptors mediate neuronal intercommunication in the central nervous system by coupling extracellular neurotransmitter-receptor interactions to ion channel conductivity. To gain insight into structural and dynamical factors that underlie this coupling, solution NMR experiments were performed on the bi-lobed ligand-binding core of glutamate receptor 2 in complexes with a set of willardiine partial agonists. These agonists are valuable for studying structure-function relationships because their 5-position substituent size is correlated with ligand efficacy and extent of receptor desensitization whereas the substituent electronegativity is correlated with ligand potency. NMR results show that the protein backbone amide chemical shift deviations correlate mainly with efficacy and extent of desensitization. Pronounced deviations occur at specific residues in the ligand-binding site and in the two helical segments that join the lobes by a disulfide bond. Experiments detecting conformational exchange show that micro- to millisecond timescale motions also occur near the disulfide bond and vary largely with efficacy and extent of desensitization. These results thus identify regions displaying structural and dynamical dissimilarity arising from differences in ligand-protein interactions and lobe closure which may play a critical role in receptor response. Furthermore, measures of line broadening and conformational exchange for a portion of the ligand-binding site correlate with ligand EC50 data. These results do not have any correlate in the currently available crystal structures and thus provide a novel view of ligand-binding events that may be associated with agonist potency differences. PMID:18387631

Unique and shared areas of cognitive function in children with intractable frontal or temporal lobe epilepsy.

PubMed

Law, Nicole; Widjaja, Elysa; Smith, Mary Lou

2018-03-01

Previous findings have been mixed in terms of identifying a distinct pattern of neuropsychological deficits in children with frontal lobe epilepsy (FLE) and in those with temporal lobe epilepsy (TLE). The current study investigated the neuropsychological similarities and differences across these two pediatric medically intractable localization-related epilepsies. Thirty-eight children with FLE, 20 children with TLE, and 40 healthy children (HC) participated in this study. A comprehensive battery of standardized tests assessed five neuropsychological domains including intelligence, language, memory, executive function, and motor function. A principal component analysis (PCA) was used to distill our neuropsychological measures into latent components to compare between groups. Principal component analysis extracted 5 latent components: executive function (F1), verbal semantics (F2), motor (F3), nonverbal cognition/impulsivity (F4), and verbal cognition/attention (F5). The group with FLE differed from the HC group on F1, F2, F4, and F5, and had worse performance than the group with TLE on F1; the group with TLE had lower performance relative to the HC group on F2. Our findings suggest that, in comparison with neurotypically developing children, children with medically intractable FLE have more widespread neuropsychological impairments than do children with TLE. The differences between the two patient groups were greatest for the factor score most clearly related to executive function. The results provide mixed support for the concept of specificity in neuropsychological dysfunction among different subtypes of localization-related medically intractable childhood epilepsies. Copyright © 2018 Elsevier Inc. All rights reserved.

Semantic and episodic memory in children with temporal lobe epilepsy: do they relate to literacy skills?

PubMed

Lah, Suncica; Smith, Mary Lou

2014-01-01

Children with temporal lobe epilepsy are at risk for deficits in new learning (episodic memory) and literacy skills. Semantic memory deficits and double dissociations between episodic and semantic memory have recently been found in this patient population. In the current study we investigate whether impairments of these 2 distinct memory systems relate to literacy skills. 57 children with unilateral temporal lobe epilepsy completed tests of verbal memory (episodic and semantic) and literacy skills (reading and spelling accuracy, and reading comprehension). For the entire group, semantic memory explained over 30% of variance in each of the literacy domains. Episodic memory explained a significant, but rather small proportion (< 10%) of variance in reading and spelling accuracy, but not in reading comprehension. Moreover, when children with opposite patterns of specific memory impairments (intact semantic/impaired episodic, intact episodic/impaired semantic) were compared, significant reductions in literacy skills were evident only in children with semantic memory impairments, but not in children with episodic memory impairments relative to the norms and to children with temporal lobe epilepsy who had intact memory. Our study provides the first evidence for differential relations between episodic and semantic memory impairments and literacy skills in children with temporal lobe epilepsy. As such, it highlights the urgent need to consider semantic memory deficits in management of children with temporal lobe epilepsy and undertake further research into the nature of reading difficulties of children with semantic memory impairments.

Neuropsychological deficits in temporal lobe epilepsy: A comprehensive review

PubMed Central

Zhao, Fengqing; Kang, Hai; You, LIbo; Rastogi, Priyanka; Venkatesh, D.; Chandra, Mina

2014-01-01

Temporal lobe epilepsy (TLE) is the most prevalent form of complex partial seizures with temporal lobe origin of electrical abnormality. Studies have shown that recurrent seizures affect all aspects of cognitive functioning, including memory, language, praxis, executive functions, and social judgment, among several others. In this article, we will review these cognitive impairments along with their neuropathological correlates in a comprehensive manner. We will see that neuropsychological deficits are prevalent in TLE. Much of the effort has been laid on memory due to the notion that temporal lobe brain structures involved in TLE play a central role in consolidating information into memory. It seems that damage to the mesial structure of the temporal lobe, particularly the amygdale and hippocampus, has the main role in these memory difficulties and the neurobiological plausibility of the role of the temporal lobe in different aspects of memory. Here, we will cover the sub-domains of working memory and episodic memory deficits. This is we will further proceed to evaluate the evidences of executive function deficits in TLE and will see that set-shifting among other EFs is specifically affected in TLE as is social cognition. Finally, critical components of language related deficits are also found in the form of word-finding difficulties. To conclude, TLE affects several of cognitive function domains, but the etiopathogenesis of all these dysfunctions remain elusive. Further well-designed studies are needed for a better understanding of these disorders. PMID:25506156

Postencephalitic focal retrograde amnesia after bilateral anterior temporal lobe damage.

PubMed

Tanaka, Y; Miyazawa, Y; Hashimoto, R; Nakano, I; Obayashi, T

1999-07-22

Marked retrograde amnesia with no or almost no anterograde amnesia is rare. Recently, a combination of ventrolateral prefrontal and temporopolar cortical lesions has been suggested as the cause of such isolated or focal retrograde amnesia. It is also assumed that when the right-sided cortical structures are damaged, autobiographical episodic memories are affected. To search for new anatomic substrates for focal retrograde amnesia. We performed extensive neuropsychological tests and obtained detailed neuroimages on a 43-year-old woman who showed a severe, persistent retrograde amnesia but only a limited anterograde amnesia after probable herpes simplex encephalitis. Tests of autobiographical memory revealed that she had a memory loss extending back to her childhood for both semantics and incidents; however, the ability to recall specific episodes appeared much more severely impaired than the ability to recall factual information about her past. The patient also showed profound impairments in recalling public memories; however, her scores improved nearly to a control level on forced-choice recognition memory tasks, although the recall of memories for a decade just before her illness remained mildly impaired. MRI revealed focal pathologies in the temporal poles and the anterior parts of the inferotemporal lobes on both sides, predominantly on the left, with some extension to the anterior parts of the medial temporal lobes. There was additional damage to the left insular cortex and its surrounding structures but no evidence of frontal lobe damage on MRIs or cognitive tests. A profound retrograde amnesia may be produced by damage to the bilateral temporal poles and anterior inferotemporal lobes in the absence of frontal lobe pathologies, and a dense and persistent episodic old memory loss can arise even with a relatively small lesion in the right anterior temporal lobe if it is combined with extensive damage to the left.

Automated MRI parcellation of the frontal lobe.

PubMed

Ranta, Marin E; Chen, Min; Crocetti, Deana; Prince, Jerry L; Subramaniam, Krish; Fischl, Bruce; Kaufmann, Walter E; Mostofsky, Stewart H

2014-05-01

Examination of associations between specific disorders and physical properties of functionally relevant frontal lobe sub-regions is a fundamental goal in neuropsychiatry. Here, we present and evaluate automated methods of frontal lobe parcellation with the programs FreeSurfer(FS) and TOADS-CRUISE(T-C), based on the manual method described in Ranta et al. [2009]: Psychiatry Res 172:147-154 in which sulcal-gyral landmarks were used to manually delimit functionally relevant regions within the frontal lobe: i.e., primary motor cortex, anterior cingulate, deep white matter, premotor cortex regions (supplementary motor complex, frontal eye field, and lateral premotor cortex) and prefrontal cortex (PFC) regions (medial PFC, dorsolateral PFC, inferior PFC, lateral orbitofrontal cortex [OFC] and medial OFC). Dice's coefficient, a measure of overlap, and percent volume difference were used to measure the reliability between manual and automated delineations for each frontal lobe region. For FS, mean Dice's coefficient for all regions was 0.75 and percent volume difference was 21.2%. For T-C the mean Dice's coefficient was 0.77 and the mean percent volume difference for all regions was 20.2%. These results, along with a high degree of agreement between the two automated methods (mean Dice's coefficient = 0.81, percent volume difference = 12.4%) and a proof-of-principle group difference analysis that highlights the consistency and sensitivity of the automated methods, indicate that the automated methods are valid techniques for parcellation of the frontal lobe into functionally relevant sub-regions. Thus, the methodology has the potential to increase efficiency, statistical power and reproducibility for population analyses of neuropsychiatric disorders with hypothesized frontal lobe contributions. Copyright © 2013 Wiley Periodicals, Inc.

Scale independence of décollement thrusting

USGS Publications Warehouse

McBride, John H.; Pugin, Andre J.M.; Hatcher, Robert D.

2007-01-01

Orogen-scale décollements (detachment surfaces) are an enduring subject of investigation by geoscientists. Uncertainties remain as to how crustal convergence processes maintain the stresses necessary for development of low-angle fault surfaces above which huge slabs of rock are transported horizontally for tens to hundreds of kilometers. Seismic reflection profiles from the southern Appalachian crystalline core and several foreland fold-and-thrust belts provide useful comparisons with high-resolution shallow-penetration seismic reflection profiles acquired over the frontal zone of the Michigan lobe of the Wisconsinan ice sheet northwest of Chicago, Illinois. These profiles provide images of subhorizontal and overlapping dipping reflections that reveal a ramp-and-flat thrust system developed in poorly consolidated glacial till. The system is rooted in a master décollement at the top of bedrock. These 2–3 km long images contain analogs of images observed in seismic reflection profiles from orogenic belts, except that the scale of observation in the profiles in glacial materials is two orders of magnitude less. Whereas the décollement beneath the ice lobe thrust belt lies ∼70 m below thrusted anticlines having wavelengths of tens of meters driven by an advancing ice sheet, seismic images from overthrust terranes are related to lithospheric convergence that produces décollements traceable for thousands of kilometers at depths ranging from a few to over 10 km. Dual vergence or reversals in vergence (retrocharriage) that developed over abrupt changes in depth to the décollement can be observed at all scales. The strikingly similar images, despite the contrast in scale and driving mechanism, suggest a scale- and driving mechanism–independent behavior for décollement thrust systems. All these systems initially had the mechanical properties needed to produce very similar geometries with a compressional driving mechanism directed subparallel to Earth's surface. Subduction-related accretionary complexes also produce thrust systems with similar geometries in semi- to unconsolidated materials.

Errors on the Trail Making Test Are Associated with Right Hemispheric Frontal Lobe Damage in Stroke Patients

PubMed Central

Kopp, Bruno; Rösser, Nina; Tabeling, Sandra; Stürenburg, Hans Jörg; de Haan, Bianca; Karnath, Hans-Otto; Wessel, Karl

2015-01-01

Measures of performance on the Trail Making Test (TMT) are among the most popular neuropsychological assessment techniques. Completion time on TMT-A is considered to provide a measure of processing speed, whereas completion time on TMT-B is considered to constitute a behavioral measure of the ability to shift between cognitive sets (cognitive flexibility), commonly attributed to the frontal lobes. However, empirical evidence linking performance on the TMT-B to localized frontal lesions is mostly lacking. Here, we examined the association of frontal lesions following stroke with TMT-B performance measures (i.e., completion time and completion accuracy measures) using voxel-based lesion-behavior mapping, with a focus on right hemispheric frontal lobe lesions. Our results suggest that the number of errors, but not completion time on the TMT-B, is associated with right hemispheric frontal lesions. This finding contradicts common clinical practice—the use of completion time on the TMT-B to measure cognitive flexibility, and it underscores the need for additional research on the association between cognitive flexibility and the frontal lobes. Further work in a larger sample, including left frontal lobe damage and with more power to detect effects of right posterior brain injury, is necessary to determine whether our observation is specific for right frontal lesions. PMID:26074673

An unusual association of headache, epilepsy, and late-onset Kleist's pseudodepression syndrome in frontal lobe cavernoma of the cerebral left hemisphere.

PubMed

Chirchiglia, Domenico; Della Torre, Attilio; Murrone, Domenico; Chirchiglia, Pasquale; Marotta, Rosa

2017-01-01

Cerebral cavernous angioma or cavernoma is a benign vascular malformation, usually asymptomatic. It is infrequent and often its discovery is incidental, a so-called incidentaloma. However, these lesions can be symptomatic, causing headaches, epilepsy, cerebral hemorrhage and other neurological signs depending on the brain area involved. Frontal localization is responsible for psychiatric disorders, particularly the prefrontal region, leading to prefrontal syndrome, a condition common in all frontal lobe tumors. Psychopathological syndrome can be depression-type, pseudodepression syndrome or maniac-type, pseudomaniac syndrome. Surgical treatment of lesions like this may not always be possible due to their location in eloquent areas. In this study, we describe an unusual association of migraine-like headache, epilepsy and frontal lobe pseudodepression late-onset syndrome in the same patient. We have considered this case interesting mainly for the rarity of both a headache with migraine features and for the late onset of pseudodepression syndrome. Pathophysiology underlying migraine-like headache and that concerning the late-onset pseudodepression frontal lobe syndrome seems to be unclear. This case leads to further hypotheses about the mechanisms responsible for headache syndromes and psychopathological disorders, in the specific case when caused by a cerebral frontal lobe lesion.

Dorsolateral Frontal Lobe Epilepsy

PubMed Central

Lee, Ricky W.; Worrell, Greg A.

2012-01-01

Dorsolateral frontal lobe seizures often present as a diagnostic challenge. The diverse semiologies may not produce lateralizing or localizing signs, and can appear bizarre and suggest psychogenic events. Unfortunately, scalp EEG and MRI are often unsatisfactory. It is not uncommon that these traditional diagnostic studies are either unhelpful or even misleading. In some cases SPECT and PET imaging can be an effective tool to identify the origin of seizures. However, these techniques and other emerging techniques all have limitations, and new approaches are needed to improve source localization. PMID:23027094

Discovery of a suspected giant radio galaxy with the KAT-7 array

NASA Astrophysics Data System (ADS)

Colafrancesco, S.; Mhlahlo, N.; Jarrett, T.; Oozeer, N.; Marchegiani, P.

2016-02-01

We detect a new suspected giant radio galaxy (GRG) discovered by KAT-7. The GRG core is identified with the Wide-field Infrared Survey Explorer source J013313.50-130330.5, an extragalactic source based on its infrared colours and consistent with a misaligned active galactic nuclei-type spectrum at z ≈ 0.3. The multi-ν spectral energy distribution (SED) of the object associated with the GRG core shows a synchrotron peak at ν ≈ 1014 Hz consistent with the SED of a radio galaxy blazar-like core. The angular size of the lobes are ˜4 arcmin for the NW lobe and ˜1.2 arcmin for the SE lobe, corresponding to projected linear distances of ˜1078 kpc and ˜324 kpc, respectively. The best-fitting parameters for the SED of the GRG core and the value of jet boosting parameter δ = 2, indicate that the GRG jet has maximum inclination θ ≈ 30 deg with respect to the line of sight, a value obtained for δ = Γ, while the minimum value of θ is not constrained due to the degeneracy existing with the value of Lorentz factor Γ. Given the photometric redshift z ≈ 0.3, this GRG shows a core luminosity of P1.4 GHz ≈ 5.52 × 1024 W Hz-1, and a luminosity P1.4 GHz ≈ 1.29 × 1025 W Hz-1 for the NW lobe and P1.4 GHz ≈ 0.46 × 1025 W Hz-1 for the SE lobe, consistent with the typical GRG luminosities. The radio lobes show a fractional linear polarization ≈9 per cent consistent with typical values found in other GRG lobes.

[INCIDENCE AND SURGICAL IMPORTANCE OF PYRAMIDAL LOBE AND TUBERCLE OF THE THYROID GLAND: A PROSPECTIVE STUDY].

PubMed

Kovacić, Marijan; Kovadcić, Ivan

2015-01-01

The pyramidal lobe and tubercles are common anatomic variations of the thyroid gland, and their frequency is highly represented. While pyramidal lobe requires additional seriousness in identifying and its removal, especially in patients with hyperthyroidism and thyroid cancer, the presence of tubercles is desirable. Tubercle is covered by recurrent laryngeal nerve and directs the surgeon in his search and besides this, serves to facilitate detection of the upper parathyroid glands. In this prospective study we analysed 342 patients who underwent total thyroidectomy in the period from January 2009 to March 2015. We looked at the incidence and anatomic characteristics of pyramidal lobe and tubercles of the thyroid gland. The pyramidal lobe was present in 52.3% of the patients with more frequent central and left placement. Bilateral tubercles were present in 14.9%, while position right-sided phenomenon was represented in 39.5% and 18.5% in lower left (64.3% patients). Their prevalence by gender showed no significant difference (p = 0.59; p = 0.2). Associated presence of pyramidal lobe and tubercles on one or both sides is highly represented in our group of patients (34%), also with no differences by gender (p = 0.29). Length of the pyramidal lobe ranged from 1.3 to 4.7 cm (average 2.3 cm), and the size of tubercles in 36% of patients was over 1 cm. Recurrent laryngeal nerve was only in 1.8% placed laterally of tubercles, and the upper parathyroid gland in 95.4% was located above tubercle. Considering that only 16.5% of our patients did not have any of these anatomical variations, their presence during surgery is the rule, not the exception.

Correlation between white matter damage and gray matter lesions in multiple sclerosis patients.

PubMed

Han, Xue-Mei; Tian, Hong-Ji; Han, Zheng; Zhang, Ce; Liu, Ying; Gu, Jie-Bing; Bakshi, Rohit; Cao, Xia

2017-05-01

We observed the characteristics of white matter fibers and gray matter in multiple sclerosis patients, to identify changes in diffusion tensor imaging fractional anisotropy values following white matter fiber injury. We analyzed the correlation between fractional anisotropy values and changes in whole-brain gray matter volume. The participants included 20 patients with relapsing-remitting multiple sclerosis and 20 healthy volunteers as controls. All subjects underwent head magnetic resonance imaging and diffusion tensor imaging. Our results revealed that fractional anisotropy values decreased and gray matter volumes were reduced in the genu and splenium of corpus callosum, left anterior thalamic radiation, hippocampus, uncinate fasciculus, right corticospinal tract, bilateral cingulate gyri, and inferior longitudinal fasciculus in multiple sclerosis patients. Gray matter volumes were significantly different between the two groups in the right frontal lobe (superior frontal, middle frontal, precentral, and orbital gyri), right parietal lobe (postcentral and inferior parietal gyri), right temporal lobe (caudate nucleus), right occipital lobe (middle occipital gyrus), right insula, right parahippocampal gyrus, and left cingulate gyrus. The voxel sizes of atrophic gray matter positively correlated with fractional anisotropy values in white matter association fibers in the patient group. These findings suggest that white matter fiber bundles are extensively injured in multiple sclerosis patients. The main areas of gray matter atrophy in multiple sclerosis are the frontal lobe, parietal lobe, caudate nucleus, parahippocampal gyrus, and cingulate gyrus. Gray matter atrophy is strongly associated with white matter injury in multiple sclerosis patients, particularly with injury to association fibers.

Temporal lobe origin is common in patients who have undergone epilepsy surgery for hypermotor seizures.

PubMed

Arain, Amir M; Azar, Nabil J; Lagrange, Andre H; McLean, Michael; Singh, Pradumna; Sonmezturk, Hasan; Konrad, Peter; Neimat, Joseph; Abou-Khalil, Bassel

2016-11-01

Hypermotor seizures are most often reported from the frontal lobe but may also have temporal, parietal, or insular origin. We noted a higher proportion of patients with temporal lobe epilepsy in our surgical cohort who had hypermotor seizures. We evaluated the anatomic localization and surgical outcome in patient with refractory hypermotor seizures who had epilepsy surgery in our center. We identified twenty three patients with refractory hypermotor seizures from our epilepsy surgery database. We analyzed demographics, presurgical evaluation including semiology, MRI, PET scan, interictal/ictal scalp video-EEG, intracranial recording, and surgical outcomes. We evaluated preoperative variables as predictors of outcome. Most patients (65%) had normal brain MRI. Intracranial EEG was required in 20 patients (86.9%). Based on the presurgical evaluation, the resection was anterior temporal in fourteen patients, orbitofrontal in four patients, cingulate in four patients, and temporoparietal in one patient. The median duration of follow-up after surgery was 76.4months. Fourteen patients (60%) had been seizure free at the last follow up while 3 patients had rare disabling seizures. Hypermotor seizures often originated from the temporal lobe in this series of patients who had epilepsy surgery. This large proportion of temporal lobe epilepsy may be the result of a selection bias, due to easier localization and expected better outcome in temporal lobe epilepsy. With extensive presurgical evaluation, including intracranial EEG when needed, seizure freedom can be expected in the majority of patients. Copyright © 2016. Published by Elsevier Inc.

New theoretical framework for designing nonionic surfactant mixtures that exhibit a desired adsorption kinetics behavior.

PubMed

Moorkanikkara, Srinivas Nageswaran; Blankschtein, Daniel

2010-12-21

How does one design a surfactant mixture using a set of available surfactants such that it exhibits a desired adsorption kinetics behavior? The traditional approach used to address this design problem involves conducting trial-and-error experiments with specific surfactant mixtures. This approach is typically time-consuming and resource-intensive and becomes increasingly challenging when the number of surfactants that can be mixed increases. In this article, we propose a new theoretical framework to identify a surfactant mixture that most closely meets a desired adsorption kinetics behavior. Specifically, the new theoretical framework involves (a) formulating the surfactant mixture design problem as an optimization problem using an adsorption kinetics model and (b) solving the optimization problem using a commercial optimization package. The proposed framework aims to identify the surfactant mixture that most closely satisfies the desired adsorption kinetics behavior subject to the predictive capabilities of the chosen adsorption kinetics model. Experiments can then be conducted at the identified surfactant mixture condition to validate the predictions. We demonstrate the reliability and effectiveness of the proposed theoretical framework through a realistic case study by identifying a nonionic surfactant mixture consisting of up to four alkyl poly(ethylene oxide) surfactants (C(10)E(4), C(12)E(5), C(12)E(6), and C(10)E(8)) such that it most closely exhibits a desired dynamic surface tension (DST) profile. Specifically, we use the Mulqueen-Stebe-Blankschtein (MSB) adsorption kinetics model (Mulqueen, M.; Stebe, K. J.; Blankschtein, D. Langmuir 2001, 17, 5196-5207) to formulate the optimization problem as well as the SNOPT commercial optimization solver to identify a surfactant mixture consisting of these four surfactants that most closely exhibits the desired DST profile. Finally, we compare the experimental DST profile measured at the surfactant mixture condition identified by the new theoretical framework with the desired DST profile and find good agreement between the two profiles.

Motion and volumetric change as demonstrated by 4DCT: The effects of abdominal compression on the GTV, lungs, and heart in lung cancer patients.

PubMed

Rasheed, Abdullah; Jabbour, Salma K; Rosenberg, Stephen; Patel, Ajay; Goyal, Sharad; Haffty, Bruce G; Yue, Ning J; Khan, Alvin

2016-01-01

Lung tumors move during respiration, complicating radiation therapy. The abdominal compression plate (ACP) is thought to reduce respiratory motion. This study quantifies ACP efficacy on respiratory-induced motion by using 4-dimensional computed tomography to evaluate volume and displacement changes of the heart, lungs, and tumor with and without ACP. Lung cancer patients (n = 17) received 4-dimensional computed tomography simulations (10 computed tomography scans from 0% to 90% breathing phases) with and without ACP under maximally tolerated diaphragmatic pressure. Gross tumor volume (GTV), heart, and lungs were contoured in treatment planning software for each phase. Structures were exported for analysis. For each phase, with and without ACP, tumor and organ absolute centroid range of motion and volume were calculated. ACP did not significantly affect GTV, heart, or lung motion on the sample as a whole, but instead demonstrated patient-specific results. ACP reduced GTV motion in 3 (17.6%; 3 upper lobe tumors) by 2.9 mm (P < .01), increased motion in 5 (29.4%; 3 upper lobe tumors, 1 middle lobe, 1 lower lobe) by 1.9 mm (P < .03), and did not significantly change 9. Of the 3 patients exhibiting significantly decreased GTV motion, GTV, heart, and lung range of motion was 7.4 mm, 11.8 mm, and 11.9 mm, respectively, without compression and 4.5 mm, 8.4 mm, and 10.9 mm, respectively, with compression. Averaged across the sample, ACP did not exhibit any axis-specific effect. ACP efficacy was patient-specific, possibly because of pre-existing factors including chronic obstructive pulmonary disease severity, chest wall elasticity, tumor location, and patient comfort. Tumor lobe location does not predetermine compression efficacy; therefore, patients should be simulated with and without ACP, regardless of tumor location. GTV motion seems most important in determining suitability for compression. Alternative motion control should be considered in patients not benefited by compression. In patients who benefited, ACP may enhance tumor coverage while minimizing toxicity. Larger scale studies are necessary for definitive treatment recommendations. Copyright © 2016 American Society for Radiation Oncology. Published by Elsevier Inc. All rights reserved.

Heterogeneity of neuroanatomical patterns in prodromal Alzheimer's disease: links to cognition, progression and biomarkers.

PubMed

Dong, Aoyan; Toledo, Jon B; Honnorat, Nicolas; Doshi, Jimit; Varol, Erdem; Sotiras, Aristeidis; Wolk, David; Trojanowski, John Q; Davatzikos, Christos

2017-03-01

See Coulthard and Knight (doi:10.1093/aww335) for a scientific commentary on this article.Individuals with mild cognitive impairment and Alzheimer's disease clinical diagnoses can display significant phenotypic heterogeneity. This variability likely reflects underlying genetic, environmental and neuropathological differences. Characterizing this heterogeneity is important for precision diagnostics, personalized predictions, and recruitment of relatively homogeneous sets of patients into clinical trials. In this study, we apply state-of-the-art semi-supervised machine learning methods to the Alzheimer's disease Neuroimaging cohort (ADNI) to elucidate the heterogeneity of neuroanatomical differences between subjects with mild cognitive impairment (n = 530) and Alzheimer's disease (n = 314) and cognitively normal individuals (n = 399), thereby adding to an increasing literature aiming to establish neuroanatomical and neuropathological (e.g. amyloid and tau deposition) dimensions in Alzheimer's disease and its prodromal stages. These dimensional approaches aim to provide surrogate measures of heterogeneous underlying pathologic processes leading to cognitive impairment. We relate these neuroimaging patterns to cerebrospinal fluid biomarkers, white matter hyperintensities, cognitive and clinical measures, and longitudinal trajectories. We identified four such atrophy patterns: (i) individuals with largely normal neuroanatomical profiles, who also turned out to have the least abnormal cognitive and cerebrospinal fluid biomarker profiles and the slowest clinical progression during follow-up; (ii) individuals with classical Alzheimer's disease neuroanatomical, cognitive, cerebrospinal fluid biomarkers and clinical profile, who presented the fastest clinical progression; (iii) individuals with a diffuse pattern of atrophy with relatively less pronounced involvement of the medial temporal lobe, abnormal cerebrospinal fluid amyloid-β1-42 values, and proportionally greater executive impairment; and (iv) individuals with notably focal involvement of the medial temporal lobe and a slow steady progression, likely representing in early Alzheimer's disease stages. These four atrophy patterns effectively define a 4-dimensional categorization of neuroanatomical alterations in mild cognitive impairment and Alzheimer's disease that can complement existing dimensional approaches for staging Alzheimer's disease using a variety of biomarkers, which offer the potential for enabling precision diagnostics and prognostics, as well as targeted patient recruitment of relatively homogeneous subgroups of subjects for clinical trials. © The Author (2016). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Identification and substrate prediction of new Fragaria x ananassa aquaporins and expression in different tissues and during strawberry fruit development.

PubMed

Merlaen, Britt; De Keyser, Ellen; Van Labeke, Marie-Christine

2018-01-01

The newly identified aquaporin coding sequences presented here pave the way for further insights into the plant-water relations in the commercial strawberry ( Fragaria x ananassa ). Aquaporins are water channel proteins that allow water to cross (intra)cellular membranes. In Fragaria x ananassa , few of them have been identified hitherto, hampering the exploration of the water transport regulation at cellular level. Here, we present new aquaporin coding sequences belonging to different subclasses: plasma membrane intrinsic proteins subtype 1 and subtype 2 (PIP1 and PIP2) and tonoplast intrinsic proteins (TIP). The classification is based on phylogenetic analysis and is confirmed by the presence of conserved residues. Substrate-specific signature sequences (SSSSs) and specificity-determining positions (SDPs) predict the substrate specificity of each new aquaporin. Expression profiling in leaves, petioles and developing fruits reveals distinct patterns, even within the same (sub)class. Expression profiles range from leaf-specific expression over constitutive expression to fruit-specific expression. Both upregulation and downregulation during fruit ripening occur. Substrate specificity and expression profiles suggest that functional specialization exists among aquaporins belonging to a different but also to the same (sub)class.

Midline thalamic neurons are differentially engaged during hippocampus network oscillations.

PubMed

Lara-Vásquez, Ariel; Espinosa, Nelson; Durán, Ernesto; Stockle, Marcelo; Fuentealba, Pablo

2016-07-14

The midline thalamus is reciprocally connected with the medial temporal lobe, where neural circuitry essential for spatial navigation and memory formation resides. Yet, little information is available on the dynamic relationship between activity patterns in the midline thalamus and medial temporal lobe. Here, we report on the functional heterogeneity of anatomically-identified thalamic neurons and the differential modulation of their activity with respect to dorsal hippocampal rhythms in the anesthetized mouse. Midline thalamic neurons expressing the calcium-binding protein calretinin, irrespective of their selective co-expression of calbindin, discharged at overall low levels, did not increase their activity during hippocampal theta oscillations, and their firing rates were inhibited during hippocampal sharp wave-ripples. Conversely, thalamic neurons lacking calretinin discharged at higher rates, increased their activity during hippocampal theta waves, but remained unaffected during sharp wave-ripples. Our results indicate that the midline thalamic system comprises at least two different classes of thalamic projection neuron, which can be partly defined by their differential engagement by hippocampal pathways during specific network oscillations that accompany distinct behavioral contexts. Thus, different midline thalamic neuronal populations might be selectively recruited to support distinct stages of memory processing, consistent with the thalamus being pivotal in the dialogue of cortical circuits.

Examining Neural Correlates of Psychopathology Using a Lesion-Based Approach.

PubMed

Calamia, Matthew; Markon, Kristian E; Sutterer, Matthew J; Tranel, Daniel

2018-06-22

Studies of individuals with focal brain damage have long been used to expand understanding of the neural basis of psychopathology. However, most previous studies were conducted using small sample sizes and relatively coarse methods for measuring psychopathology or mapping brain-behavior relationships. Here, we examined the factor structure and neural correlates of psychopathology in 232 individuals with focal brain damage, using their responses to the Minnesota Multiphasic Personality Inventory-2-Restructured Form (MMPI-2-RF). Factor analysis and voxel-based lesion symptom mapping were used to examine the structure and neural correlates of psychopathology in this sample. Consistent with existing MMPI-2-RF literature, separate internalizing, externalizing, and psychotic symptom dimensions were found. In addition, a somatic dimension likely reflecting neurological symptoms was identified. Damage to the medial temporal lobe, including the hippocampus, was associated with scales related to both internalizing problems and psychoticism. Damage to the medial temporal lobe and orbitofrontal cortex was associated with both a general distrust of others and beliefs that one is being personally targeted by others. These findings provide evidence for the critical role of dysfunction in specific frontal and temporal regions in the development of psychopathology. Copyright © 2018. Published by Elsevier Ltd.

Automated volumetry for unilateral hippocampal sclerosis detection in patients with temporal lobe epilepsy.

PubMed

Martins, Cristina; Moreira da Silva, Nadia; Silva, Guilherme; Rozanski, Verena E; Silva Cunha, Joao Paulo

2016-08-01

Hippocampal sclerosis (HS) is the most common cause of temporal lobe epilepsy (TLE) and can be identified in magnetic resonance imaging as hippocampal atrophy and subsequent volume loss. Detecting this kind of abnormalities through simple radiological assessment could be difficult, even for experienced radiologists. For that reason, hippocampal volumetry is generally used to support this kind of diagnosis. Manual volumetry is the traditional approach but it is time consuming and requires the physician to be familiar with neuroimaging software tools. In this paper, we propose an automated method, written as a script that uses FSL-FIRST, to perform hippocampal segmentation and compute an index to quantify hippocampi asymmetry (HAI). We compared the automated detection of HS (left or right) based on the HAI with the agreement of two experts in a group of 19 patients and 15 controls, achieving 84.2% sensitivity, 86.7% specificity and a Cohen's kappa coefficient of 0.704. The proposed method is integrated in the "Advanced Brain Imaging Lab" (ABrIL) cloud neurocomputing platform. The automated procedure is 77% (on average) faster to compute vs. the manual volumetry segmentation performed by an experienced physician.

Gastric injury from (90)Y to left hepatic lobe tumors adjacent to the stomach: fact or fiction?

PubMed

Gates, Vanessa L; Hickey, Ryan; Marshall, Karen; Williams, Melissa; Salzig, Krystina; Lewandowski, Robert J; Salem, Riad

2015-12-01

Radioembolization with (90)Y microspheres is a locoregional radiation therapy for unresectable hepatic neoplasm. Non-target delivery of (90)Y microspheres resulting in gastrointestinal (GI) symptoms is a recognized complication; there is minimal knowledge regarding the radiation effect to the gastric wall from left hepatic lobe (90)Y treatments. Our aim was to study the incidence of GI complications when the target tissue (hepatic parenchyma ± tumor) is in close proximity to the gastric wall. We hypothesized that liver (tumor) to stomach proximity does not correlate with increased toxicity. Between November 2011 and September 2013, we studied all patients who underwent left lobe radioembolization with (90)Y glass microspheres. With Institutional Review Board (IRB) approval, we retrospectively reviewed MRI/CT images of these patients, identifying a subset of patients with the left hepatic lobe <1 cm from the gastric wall. Patients were seen in clinic 1 month posttreatment and subsequently at 3-month intervals. Short- and long-term gastric adverse events were tabulated. Ninety-seven patients successfully underwent left hepatic lobe (90)Y microsphere radioembolization in which the average distance from the liver to the stomach wall was 1.0 ± 2.8 mm. The average dose for patients who received radioembolization to the left hepatic lobe was 109 ± 57 Gy. Fifty patients had tumor within 1 cm of the gastric wall. The average dose for patients who received radioembolization to the left hepatic lobe with tumor within 1 cm of the gastric wall was 121 ± 41 Gy. There were no reportable or recordable medical events. Of the patients, 34% reported abdominal pain that was grade 1-2; 65% of the patients reported no abdominal pain. None of the 97 patients developed a clinically evident GI ulcer. Patients with left lobe tumors adjacent to or abutting the stomach do not exhibit acute or chronic radiation effects following radioembolization with glass microspheres.

[Clinical characteristics of epileptic seizures in insular gliomas].

PubMed

Buklina, S B; Bykanov, A E; Pitskhelauri, D I

To study the characteristics of epileptic seizures in insular gliomas. Forty-five patients with insular gliomas were examined. The spread of a tumor was established by MRI results and intraoperational findings. A tumor within the insular only was found in 9 out of 45 patients (7 left-sided and 2 right-sided). In 36 patients, a tumor slightly spread into temporal lobe pole and medial-basal regions of the frontal lobe (27 left-sided and 18 right-sided). The control group consisted of 50 patients with tumors of temporal and frontal lobes. Paroxysmal symptoms were similar in patients with tumors of the insular and patients with tumors of temporal lobes. Seizures in patients with frontal lobe tumors differed significantly from insular and temporal tumors, with the exception of a tumor localized in the opercula area. The following quantitative differences were identified: different forms of unconsciousness were significantly less frequent in symptomatic epilepsy in patients with insular tumor than in epilepsy caused by temporal lobe tumors (36% of patients vs 84% in temporal tumors (p<0.0001)). In patients with insular tumors, olfactory and taste hallucinations occur more often compared to temporal lobe tumors (51% vs 16% (p<0.003). The frequency of paroxysmal seizures of fear and anxiety in patients with those tumors was similar (20% with insular tumors and 14 with temporal tumors). An autonomic component of episeizures did not differ between tumors of both localizations. Olfactory and taste hallucinations were qualitatively similar in insular and temporal lobe tumors: smell and taste were unpleasant or associated with a danger: smell of burning, gas, something spoiled, sour, tart chemistry, taste of somethong metallic, chemical, sour. No pleasant smell or taste were reported. Epileptic seizures in insular tumors had similarities and certain differences compared with temporal seizures that well reflect function of the insula and its links, in the first turn, with limbic system structures.

Frontal and temporal lobe involvement on verbal fluency measures in amyotrophic lateral sclerosis.

PubMed

Lepow, Lauren; Van Sweringen, James; Strutt, Adriana M; Jawaid, Ali; MacAdam, Claire; Harati, Yadollah; Schulz, Paul E; York, Michele K

2010-11-01

Amyotrophic lateral sclerosis (ALS) has been associated with changes in frontal and temporal lobe-mediated cognitive and behavioral functions. Verbal fluency, a sensitive measure to these changes, was utilized to investigate phonemic and semantic abilities in 49 ALS patients and 25 healthy controls (HCs). A subset of the ALS patients was classified as ALS-intact, ALS with mild cognitive impairments (ALS-mild), and ALS with fronto-temporal dementia (ALS-FTD) based on a comprehensive neuropsychological evaluation. Clustering and switching, the underlying component processes of verbal fluency, were analyzed using Troyer's (Troyer, Moscovitch, & Winocur, 1997) and Abwender's (Abwender, Swan, Bowerman, & Connolly, 2001) scoring systems. ALS patients exhibited decreased fluency versus HCs. For phonemic fluency, the intact ALS sample generated fewer clusters and more switches than the ALS-mild and ALS-FTD patients using both scoring systems. This suggests temporal involvement in ALS patients, with increasing frontal lobe involvement in patients with greater cognitive dysfunction. For semantic fluency, similar results were obtained with a greater emphasis on declines in clustering or increased temporal lobe dysfunction. These results suggest that verbal fluency measures identify frontal and temporal lobe involvement in the cognitive decline associated with ALS, particularly when the component processes are evaluated. The clinical utility of these scoring systems with ALS patients is also discussed.

Proteomic analysis and comparison of the biopsy and autopsy specimen of human brain temporal lobe.

PubMed

He, Sizhi; Wang, Qingsong; He, Jintang; Pu, Hai; Yang, Wei; Ji, Jianguo

2006-09-01

The proteomic study on human temporal lobe can help us to understand the physiological function of CNS in normal as well as in pathological state. Proteomic tools are potent for the assessment of protein stability post mortem. In this pilot study, the human temporal lobe biopsy specimen with chronic pharmacoresistant temporal lobe epilepsy (TLE) and autopsy specimen in control were separated by 2-DE. Using MALDI-TOF-MS and MS/MS, 375 protein spots were identified which were the products of 267 genes. Six down-regulated and 23 up-regulated protein spots in the autopsy specimen were ascertained after the gel image analysis with the ImageMaster software. A number of proteins that include neurotransmitter metabolic and glycolytic enzymes, cytoprotective proteins and cytoskeleton were found decreased while the precursor of apolipoprotein A-I increased in the TLE brain. We tried several methods to prepare the protein samples and found that DNase and RNase treatment, ultracentrifugation and Amersham clean-up kit purification can improve gel separation quality. This work optimized the sample preparation method and constructed a primary protein database of human temporal lobe and found some proteins with remarkable level change probably involved in the post-mortem process and chronic pharmacoresistant TLE pathogenesis.

Tamoxifen-induced non-alcoholic steatohepatitis in patients with breast cancer: determination of a suitable biopsy site for diagnosis.

PubMed

Murata, Yoriko; Ogawa, Yasuhiro; Saibara, Toshiji; Nishioka, Akihito; Takeuchi, Naoko; Kariya, Shinji; Onishi, Saburo; Yoshida, Shoji

2003-01-01

We have evaluated the distribution of fatty infiltration in the liver for determination of a suitable biopsy site for diagnosis of tamoxifen-induced non-alcoholic steatohepatitis (NASH) in patients with breast cancer. Thirty-eight consecutive breast cancer patients undergoing tamoxifen treatment were analyzed by CT to identify hepatic steatosis (HS) via calculation of the liver/spleen CT ratio in Couinaud's 8 areas. We defined hepatic fatty infiltration as a liver/spleen ratio of less than 0.9. The extent and distribution of the fatty infiltration was assessed using the liver/spleen ratio of the patients who had the lowest CT ratio below 0.9 in the 8 areas. Thirteen (34.2%) of the 38 patients had hepatic fatty infiltration. The liver/spleen ratios of each area differed significantly in all patients (p<0.0001). The CT ratio of these 13 patients was significantly lower in the right lobe than the left lobe (p<0.0001), although the ratios did not differ significantly among the 4 areas of the right lobe (p=0.52). Needle biopsy for diagnosis of NASH should be performed at the right lobe, which contains significantly more infiltrated fat than the left lobe in the liver.

Upper lobe fibrosis: a novel manifestation of chronic allograft dysfunction in lung transplantation.

PubMed

Pakhale, Smita Sakha; Hadjiliadis, Denis; Howell, David N; Palmer, Scott M; Gutierrez, Carlos; Waddell, Thomas K; Chaparro, Cecilia; Davis, R Duane; Keshavjee, Shaf; Hutcheon, Michael A; Singer, Lianne G

2005-09-01

Lung transplantation is an established treatment modality for a number of chronic lung diseases. Long-term survival after lung transplantation is limited by chronic allograft dysfunction, usually manifested by bronchiolitis obliterans syndrome. We describe a case series with upper lobe fibrosis, a novel presentation of chronic allograft dysfunction. We reviewed lung transplants at the Toronto General Hospital and Duke University Hospital from 1990 to 2002 and identified patients with upper lobe fibrosis. Thirteen of 686 patients (6 women) developed upper lobe fibrosis (Toronto, 9; Duke, 4); 12 of 13 had bilateral transplants. The median age at diagnosis was 42 years (range, 19-70). Primary diagnoses were cystic fibrosis, 6; emphysema, 4; sarcoidosis, 1; and pulmonary fibrosis, 2 patients. Radiographic diagnosis was made at a median of 700 days post-transplant (range, 150-2,920). Pulmonary function tests demonstrated predominantly a progressively worsening restrictive pattern. Open lung biopsy specimens revealed dense interstitial fibrosis, with occasional features of obliterative bronchitis, bronchiolitis obliterans obstructive pneumonia, and aspiration. Nine patients died at a median follow-up of 2,310 days (range, 266-3,740), 8 due to respiratory failure. Upper lobe fibrosis is a novel presentation of chronic allograft dysfunction in lung transplant recipients and is differentiated from bronchiolitis obliterans syndrome on the basis of physiologic and radiologic findings.

A multilevel-ROI-features-based machine learning method for detection of morphometric biomarkers in Parkinson's disease.

PubMed

Peng, Bo; Wang, Suhong; Zhou, Zhiyong; Liu, Yan; Tong, Baotong; Zhang, Tao; Dai, Yakang

2017-06-09

Machine learning methods have been widely used in recent years for detection of neuroimaging biomarkers in regions of interest (ROIs) and assisting diagnosis of neurodegenerative diseases. The innovation of this study is to use multilevel-ROI-features-based machine learning method to detect sensitive morphometric biomarkers in Parkinson's disease (PD). Specifically, the low-level ROI features (gray matter volume, cortical thickness, etc.) and high-level correlative features (connectivity between ROIs) are integrated to construct the multilevel ROI features. Filter- and wrapper- based feature selection method and multi-kernel support vector machine (SVM) are used in the classification algorithm. T1-weighted brain magnetic resonance (MR) images of 69 PD patients and 103 normal controls from the Parkinson's Progression Markers Initiative (PPMI) dataset are included in the study. The machine learning method performs well in classification between PD patients and normal controls with an accuracy of 85.78%, a specificity of 87.79%, and a sensitivity of 87.64%. The most sensitive biomarkers between PD patients and normal controls are mainly distributed in frontal lobe, parental lobe, limbic lobe, temporal lobe, and central region. The classification performance of our method with multilevel ROI features is significantly improved comparing with other classification methods using single-level features. The proposed method shows promising identification ability for detecting morphometric biomarkers in PD, thus confirming the potentiality of our method in assisting diagnosis of the disease. Copyright © 2017 Elsevier B.V. All rights reserved.

Voxel-based morphometry in Alzheimers disease and mild cognitive impairment: Systematic review of studies addressing the frontal lobe

PubMed Central

Ribeiro, Luís Gustavo; Busatto, Geraldo

2016-01-01

ABSTRACT Voxel-based morphometry (VBM) is a useful approach for investigating neurostructural brain changes in dementia. We systematically reviewed VBM studies of Alzheimer's disease (AD) and mild cognitive impairment (MCI), specifically focusing on grey matter (GM) atrophy in the frontal lobe. Methods: Two searches were performed on the Pubmed database. A set of exclusion criteria was applied to ensure the selection of only VBM studies that directly investigated GM volume abnormalities in AD and/or MCI patients compared to cognitively normal controls. Results: From a total of 46 selected articles, 35 VBM studies reported GM volume reductions in the frontal lobe. The frontal subregions, where most of the volume reductions were reported, included the inferior, superior and middle frontal gyri, as well as the anterior cingulate gyrus. We also found studies in which reduced frontal GM was detected in MCI patients who converted to AD. In a minority of studies, correlations between frontal GM volumes and behavioural changes or cognitive deficits in AD patients were investigated, with variable findings. Conclusion: Results of VBM studies indicate that the frontal lobe should be regarded as an important brain area when investigating GM volume deficits in association with AD. Frontal GM loss might not be a feature specific to late AD only. Future VBM studies involving large AD samples are warranted to further investigate correlations between frontal volume deficits and both cognitive impairment and neuropsychiatric symptoms. PMID:29213441

Impairments in proverb interpretation following focal frontal lobe lesions.

PubMed

Murphy, Patrick; Shallice, Tim; Robinson, Gail; MacPherson, Sarah E; Turner, Martha; Woollett, Katherine; Bozzali, Marco; Cipolotti, Lisa

2013-09-01

The proverb interpretation task (PIT) is often used in clinical settings to evaluate frontal "executive" dysfunction. However, only a relatively small number of studies have investigated the relationship between frontal lobe lesions and performance on the PIT. We compared 52 patients with unselected focal frontal lobe lesions with 52 closely matched healthy controls on a proverb interpretation task. Participants also completed a battery of neuropsychological tests, including a fluid intelligence task (Raven's Advanced Progressive Matrices). Lesions were firstly analysed according to a standard left/right sub-division. Secondly, a finer-grained analysis compared the performance of patients with medial, left lateral and right lateral lesions with healthy controls. Thirdly, a contrast of specific frontal subgroups compared the performance of patients with medial lesions with patients with lateral frontal lesions. The results showed that patients with left frontal lesions were significantly impaired on the PIT, while in patients with right frontal lesions the impairments approached significance. Medial frontal patients were the only frontal subgroup impaired on the PIT, relative to healthy controls and lateral frontal patients. Interestingly, an error analysis indicated that a significantly higher number of concrete responses were found in the left lateral subgroup compared to healthy controls. We found no correlation between scores on the PIT and on the fluid intelligence task. Overall our results suggest that specific regions of the frontal lobes contribute to the performance on the PIT. © 2013 The Authors. Published by Elsevier Ltd. All rights reserved.

Profiling Performance in L1 and L2 Observed in Greek-English Bilingual Aphasia Using the Bilingual Aphasia Test: A Case Study from Cyprus

ERIC Educational Resources Information Center

Kambanaros, Maria; Grohmann, Kleanthes K.

2011-01-01

The Greek and the English versions of the Bilingual Aphasia Test (BAT) were used to assess the linguistic abilities of a premorbidly highly proficient late bilingual female after a haemorrhagic cerebrovascular accident involving the left temporo-parietal lobe. The BAT was administered in the two languages on separate occasions by the first author,…

A New Polarimetric Study of Cygnus A Using JVLA from 2-18GHz

NASA Astrophysics Data System (ADS)

Lerato Sebokolodi, Makhuduga; Perley, Rick; Carilli, Chris; Smirnov, Oleg M.; Makhathini, Sphesihle

2018-01-01

Polarimetric studies of Cygnus A [5, 1, 2, 3] have shown that this radio galaxy has unusually large rotation measures ranging from -4000 to +3000 rad m -2 for the eastern lobe (E-lobe) and -2000 to +1300 rad m -2 for western lobe(W-lobe). A challenge since then has been to identify the medium(s) responsible for these high Faraday rotations (FR). Although a majority of the FR must arise from the surrounding cluster gas, an unknown portion may arise either in the sheath or within the lobes. In these cases, some depolarization must result, along with a non λ 2 rotation of the plane of polarization. Detecting such a depolarization will enable an estimate of the internal (and/or sheath) thermal gas density. [1] found significant depolarization associated with the inner regions of the E-lobe and no depolarization associated with the W-lobe. This depolarization could be either internal to the source (Faraday depolarization) or due to unresolved small-scale fluctuations in the foreground screen (beam depolarization) [1]. The former is expected to impose significant deviations in the λ2 -law, none of which have been found to date, nor could have been found due to the limited number of frequencies employed in these studies.Since 2015, new JVLA polarimetric observations of Cygnus A have been taken, in all four configurations, covering the frequency range from 2 to 18GHz. These new data provide thousands of frequency channels at high resolution and sensitivity – opening a new opportunity to study in great detail the physics of the jets, lobes and the magnetic field of the X-ray cluster medium and lobes. Our objective is to analyze these new polarimetric data with the expectation of extending the previous work and more importantly, to investigate the possibility of any significantdeviations from the λ2-law. Initial analysis shows significant deviations from λ2 -law associated with the W-lobe. We will present these results in detail, and also the results from RM-synthesis [6, 4] and other model fitting techniques.[1] Perley et.al, 1996, 168[2] Carilli et.al, 1988, APJL, 334, L73[3] Dreher et.al, 1987, AJ, 316, 611[4] Brentjens et.al 2005, A&A, 441, 1217[5] Perley et.al. 1984, APJL, 285, L35[6] Burn 1966, MNRAS 133, 67

When two are better than one: Bilateral mesial temporal lobe contributions associated with better vocabulary skills in children and adolescents.

PubMed

Bartha-Doering, Lisa; Novak, Astrid; Kollndorfer, Kathrin; Kasprian, Gregor; Schuler, Anna-Lisa; Berl, Madison M; Fischmeister, Florian Ph S; Gaillard, William D; Alexopoulos, Johanna; Prayer, Daniela; Seidl, Rainer

2018-06-15

This study considered the involvement of the mesial temporal lobe (MTL) in language and verbal memory functions in healthy children and adolescents. We investigated 30 healthy, right-handed children and adolescents, aged 7-16, with a fMRI language paradigm and a comprehensive cognitive test battery. We found significant MTL activations during language fMRI in all participants; 63% of them had left lateralized MTL activations, 20% exhibited right MTL lateralization, and 17% showed bilateral MTL involvement during the fMRI language paradigm. Group analyses demonstrated a strong negative correlation between the lateralization of MTL activations and language functions. Specifically, children with less lateralized MTL activation showed significantly better vocabulary skills. These findings suggest that the mesial temporal lobes of both hemispheres play an important role in language functioning, even in right-handers. Our results furthermore show that bilateral mesial temporal lobe involvement is advantageous for vocabulary skills in healthy, right-handed children and adolescents. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

Disorganized behavior on Link's cube test is sensitive to right hemispheric frontal lobe damage in stroke patients

PubMed Central

Kopp, Bruno; Rösser, Nina; Tabeling, Sandra; Stürenburg, Hans Jörg; de Haan, Bianca; Karnath, Hans-Otto; Wessel, Karl

2014-01-01

One of Luria's favorite neuropsychological tasks for challenging frontal lobe functions was Link's cube test (LCT). The LCT is a cube construction task in which the subject must assemble 27 small cubes into one large cube in such a manner that only the painted surfaces of the small cubes are visible. We computed two new LCT composite scores, the constructive plan composite score, reflecting the capability to envisage a cubical-shaped volume, and the behavioral (dis-) organization composite score, reflecting the goal-directedness of cube construction. Voxel-based lesion-behavior mapping (VLBM) was used to test the relationship between performance on the LCT and brain injury in a sample of stroke patients with right hemisphere damage (N = 32), concentrated in the frontal lobe. We observed a relationship between the measure of behavioral (dis-) organization on the LCT and right frontal lesions. Further work in a larger sample, including left frontal lobe damage and with more power to detect effects of right posterior brain injury, is necessary to determine whether this observation is specific for right frontal lesions. PMID:24596552

The relationship between theory of mind and the executive functions: Evidence from patients with frontal lobe damage.

PubMed

Yeh, Zai-Ting; Tsai, Ming-Cheng; Tsai, Ming-Dar; Lo, Chiao-Yu; Wang, Kaw-Chen

2017-01-01

"Theory of mind" (ToM) refers to the ability to predict others' thoughts, intentions, beliefs, and feelings. Evidence from neuropsychology and functional imaging indicates that ToM is a domain-specific or modular architecture; however, research in development psychology has suggested that ToM is the full development of the executive functions in individuals. Therefore, the relationship between ToM and the executive functions needs to be clarified. Since the frontal lobe plays a critical role in the abilities of ToM and the executive functions, patients with frontal lobe damage were recruited for the present study. Assessments of ToM and the executive functions were performed on 23 patients with frontal lobe damage and 20 healthy controls. When controlling for the executive functions, significant differences between the patient and normal groups were found in the affective component of ToM, but not in the cognitive component. The present study suggests that in various social situations, executing ToM abilities requires logical reasoning processes provided by the executive functions. However, the reasoning processes of affective ToM are independent of executive functions.

Nonlinear focusing of ultrasonic waves by an axisymmetric diffraction grating embedded in water

NASA Astrophysics Data System (ADS)

Jiménez, N.; Romero-García, V.; Picó, R.; Garcia-Raffi, L. M.; Staliunas, K.

2015-11-01

We report the nonlinear focusing of ultrasonic waves by an axisymmetric diffraction grating immersed in water. In the linear regime, the system presents high focal gain (32 dB), with a narrow beam-width and intense side lobes as it is common in focusing by Fresnel-like lenses. Activating the nonlinearity of the host medium by using high amplitude incident waves, the focusing properties of the lens dramatically change. Theoretical predictions show that the focal gain of the system extraordinary increases in the strongly nonlinear regime (Mach number of 6.1 × 10-4). Particularly, the harmonic generation is locally activated at the focal spot, and the second harmonic beam is characterized by strongly reduced side-lobes and an excellent beam profile as experiments show in agreement with theory. The results can motivate applications in medical therapy or second harmonic imaging.

Performance Evaluation of a Biometric System Based on Acoustic Images

PubMed Central

Izquierdo-Fuente, Alberto; del Val, Lara; Jiménez, María I.; Villacorta, Juan J.

2011-01-01

An acoustic electronic scanning array for acquiring images from a person using a biometric application is developed. Based on pulse-echo techniques, multifrequency acoustic images are obtained for a set of positions of a person (front, front with arms outstretched, back and side). Two Uniform Linear Arrays (ULA) with 15 λ/2-equispaced sensors have been employed, using different spatial apertures in order to reduce sidelobe levels. Working frequencies have been designed on the basis of the main lobe width, the grating lobe levels and the frequency responses of people and sensors. For a case-study with 10 people, the acoustic profiles, formed by all images acquired, are evaluated and compared in a mean square error sense. Finally, system performance, using False Match Rate (FMR)/False Non-Match Rate (FNMR) parameters and the Receiver Operating Characteristic (ROC) curve, is evaluated. On the basis of the obtained results, this system could be used for biometric applications. PMID:22163708

Functional and Structural Correlates of Motor Speed in the Cerebellar Anterior Lobe

PubMed Central

Wenzel, Uwe; Taubert, Marco; Ragert, Patrick; Krug, Jürgen; Villringer, Arno

2014-01-01

In athletics, motor performance is determined by different abilities such as technique, endurance, strength and speed. Based on animal studies, motor speed is thought to be encoded in the basal ganglia, sensorimotor cortex and the cerebellum. The question arises whether there is a unique structural feature in the human brain, which allows “power athletes” to perform a simple foot movement significantly faster than “endurance athletes”. We acquired structural and functional brain imaging data from 32 track-and-field athletes. The study comprised of 16 “power athletes” requiring high speed foot movements (sprinters, jumpers, throwers) and 16 endurance athletes (distance runners) which in contrast do not require as high speed foot movements. Functional magnetic resonance imaging (fMRI) was used to identify speed specific regions of interest in the brain during fast and slow foot movements. Anatomical MRI scans were performed to assess structural grey matter volume differences between athletes groups (voxel based morphometry). We tested maximum movement velocity of plantarflexion (PF-Vmax) and acquired electromyographical activity of the lateral and medial gastrocnemius muscle. Behaviourally, a significant difference between the two groups of athletes was noted in PF-Vmax and fMRI indicates that fast plantarflexions are accompanied by increased activity in the cerebellar anterior lobe. The same region indicates increased grey matter volume for the power athletes compared to the endurance counterparts. Our results suggest that speed-specific neuro-functional and -structural differences exist between power and endurance athletes in the peripheral and central nervous system. PMID:24800742

Patterns of verbal learning and memory in children with intractable temporal lobe or frontal lobe epilepsy.

PubMed

Fuentes, Amanda; Smith, Mary Lou

2015-12-01

The objective of this study was to provide a better understanding of the verbal learning and memory (VLM) patterns that might differentiate children with frontal lobe epilepsy (FLE) from children with temporal lobe epilepsy (TLE) and to examine the impact of variables thought to influence outcomes (seizure laterality, age at seizure onset, age at assessment, epilepsy duration, number of antiepileptic drugs). Retrospective analyses were carried out for children with intractable unilateral TLE (n=100) and FLE (n=27) who completed standardized measures of VLM entailing lists of single words or lists of word pairs. Mean intelligent quotients and VLM scores on single words fell within the average range for both groups, whereas scores fell within the low average to borderline range on word pairs. No significant overall differences in VLM were found between the group with TLE and the group with FLE. Older age at assessment and older age at seizure onset were generally associated with better VLM in both groups but were related to better performance in a number of indices in the group with TLE and only fewer intrusions in the group with FLE. The VLM profiles of children with TLE and FLE are generally similar. Older age at assessment and older age at seizure onset have a favorable impact on both groups but are related to better encoding, retrieval, and monitoring processes for the group with TLE and improved memory monitoring (i.e., as indicated by fewer intrusions) in the group with FLE. Copyright © 2015 Elsevier Inc. All rights reserved.

Early diagenesis in the Congo deep-sea fan sediments dominated by massive terrigenous deposits: Part I - Oxygen consumption and organic carbon mineralization using a micro-electrode approach

NASA Astrophysics Data System (ADS)

Pozzato, Lara; Cathalot, Cécile; Berrached, Chabha; Toussaint, Flora; Stetten, Elsa; Caprais, Jean-Claude; Pastor, Lucie; Olu, Karine; Rabouille, Christophe

2017-08-01

Organic matter (OM) transfer from the continent to the ocean occurs across margins which constitute a major area of OM recycling and burial. The lobe complex of the Congo deep-sea fan is connected to the river mouth by a canyon and alimented by recurrent turbidity currents, containing a large proportion of labile terrigenous OM and producing high sedimentation rates. These inputs support the development of ecosystems harboring rich assemblages of vesicomyid bivalves and bacterial mats, called Habitats. Here, we present O2 microprofiles and diffusive oxygen uptake rates (DOUs) obtained during the CONGOLOBE project at six sites of this active lobe complex by in situ and on-board methods based on micro-electrode profiling. The dataset is used to determine remineralization rates and study the biogeochemical dynamics of different ecosystems of the lobe area, in order to compare levee and background sediments to the Habitats developed on the flanks of the main turbiditic channel. Levee and background sediments are characterized by significantly higher DOUs than abyssal sediments at 5000 m meters depth (2-5 mmol O2 m-2 d-1versus 1.5-2.5 mmol O2 m-2 d-1) and the Habitats are hotspots of OM remineralization with DOU values ranging between 8 and 40 mmol O2 m-2 d-1. By comparing sites near the active channel to a site located 50 km away, we show that the lobe connection to the main turbiditic channel is vital to the dense benthic communities.

Individual Neurons Confined to Distinct Antennal-Lobe Tracts in the Heliothine Moth: Morphological Characteristics and Global Projection Patterns

PubMed Central

Ian, Elena; Zhao, Xin C.; Lande, Andreas; Berg, Bente G.

2016-01-01

To explore fundamental principles characterizing chemosensory information processing, we have identified antennal-lobe projection neurons in the heliothine moth, including several neuron types not previously described. Generally, odor information is conveyed from the primary olfactory center of the moth brain, the antennal lobe, to higher brain centers via projection neuron axons passing along several parallel pathways, of which the medial, mediolateral, and lateral antennal-lobe tract are considered the classical ones. Recent data have revealed the projections of the individual tracts more in detail demonstrating three main target regions in the protocerebrum; the calyces are innervated mainly by the medial tract, the superior intermediate protocerebrum by the lateral tract exclusively, and the lateral horn by all tracts. In the present study, we have identified, via iontophoretic intracellular staining combined with confocal microscopy, individual projection neurons confined to the tracts mentioned above, plus two additional ones. Further, using the visualization software AMIRA, we reconstructed the stained neurons and registered the models into a standard brain atlas, which allowed us to compare the termination areas of individual projection neurons both across and within distinct tracts. The data demonstrate a morphological diversity of the projection neurons within distinct tracts. Comparison of the output areas of the neurons confined to the three main tracts in the lateral horn showed overlapping terminal regions for the medial and mediolateral tracts; the lateral tract neurons, on the contrary, targeted mostly other output areas in the protocerebrum. PMID:27822181

The relationship of seizure focus with depression, anxiety, and health-related quality of life in children and adolescents with epilepsy.

PubMed

Schraegle, William A; Titus, Jeffrey B

2017-03-01

For youth with epilepsy, comorbid psychiatric conditions, such as depression and anxiety, require further examination as they carry increased risk for reduced health-related quality of life (HRQOL). The current study assessed whether rates of depression, anxiety, and withdrawal behaviors differed based on seizure location. Data included parental ratings on the Behavior Assessment System for Children (BASC-2) and the Quality of Life in Childhood Epilepsy (QOLCE) questionnaire for 132 children and adolescents (mean age=11.34, SD=3.95) with generalized or partial (i.e., frontal [FLE] or temporal lobe epilepsy [TLE]) epilepsy. Our results identified clinically significant internalizing psychopathology in nearly half of our sample (41%). Although rates of internalizing behavior were similar between generalized and partial groups, children and adolescents with TLE demonstrated higher rates of depression compared to youth with FLE. No effects of laterality on internalizing behaviors were identified between TLE and FLE groups. Finally, for youth with TLE, parental depression ratings along with current number of antiepileptic medications (AEDs) were found to be significant barriers to HRQOL above and beyond anxiety, withdrawal, and epilepsy-specific variables. Temporal lobe epilepsy was associated with a two-fold risk of clinically significant depression ratings. These findings highlight the high prevalence of internalizing psychopathology features in pediatric epilepsy and offer further support for the relationship between depression and TLE in children and adolescents with epilepsy. Copyright © 2016 Elsevier Inc. All rights reserved.

Insights into the conformational switching mechanism of the human vascular endothelial growth factor receptor type 2 kinase domain.

PubMed

Chioccioli, Matteo; Marsili, Simone; Bonaccini, Claudia; Procacci, Piero; Gratteri, Paola

2012-02-27

Human vascular endothelial growth factor receptor type 2 (h-VEFGR2) is a receptor tyrosine kinase involved in the angiogenesis process and regarded as an interesting target for the design of anticancer drugs. Its activation/inactivation mechanism is related to conformational changes in its cytoplasmatic kinase domain, involving first among all the αC-helix in N-lobe and the A-loop in C-lobe. Affinity of inhibitors for the active or inactive kinase form could dictate the open or closed conformation of the A-loop, thus making the different conformations of the kinase domain receptor (KDR) domain different drug targets in drug discovery. In this view, a detailed knowledge of the conformational landscape of KDR domain is of central relevance to rationalize the efficiency and selectivity of kinase inhibitors. Here, molecular dynamics simulations were used to gain insight into the conformational switching activity of the KDR domain and to identify intermediate conformations between the two limiting active and inactive conformations. Specific energy barriers have been selectively removed to induce, and hence highlight at the atomistic level, the regulation mechanism of the A-loop opening. The proposed strategy allowed to repeatedly observe the escape of the KDR domain from the DFG-out free energy basin and to identify rare intermediate conformations between the DFG-out and the DFG-in structures to be employed in a structure-based drug discovery process.

[Simultanagnosia and scene agnosia induced by right posterior cerebral artery infarction: a case report].

PubMed

Kobayashi, Yasutaka; Muramatsu, Tomoko; Sato, Mamiko; Hayashi, Hiromi; Miura, Toyoaki

2015-01-01

A 68-year-old man was admitted to our hospital for rehabilitation of topographical disorientation. Brain magnetic resonance imaging revealed infarction in the right medial side of the occipital lobe. On neuropsychological testing, he scored low for the visual information-processing task; however, his overall cognitive function was retained. He could identify parts of the picture while describing the context picture of the Visual Perception Test for Agnosia but could not explain the contents of the entire picture, representing so-called simultanagnosia. Further, he could morphologically perceive both familiar and new scenes, but could not identify them, representing so-called scene agnosia. We report this case because simultanagnosia associated with a right occipital lobe lesion is rare.

Structural Analysis of Silicic Lavas Reveals the Importance of Endogenous Flow During Emplacement

NASA Astrophysics Data System (ADS)

Andrews, G. D.; Martens, A.; Isom, S.; Maxwell, A.; Brown, S. R.

2017-12-01

Recent observations of silicic lava flows in Chile strongly suggest sustained, endogeneous flow beneath an insulating carapace, where the flow advances through breakouts at the flow margin. New mapping of vertical exposures around the margin of Obsidian Dome, California, has identified discreet lobe structures in cross-section, suggesting that flow-front breakouts occured there during emplacement. The flow lobes are identified through structural measurements of flow-banding orientation and the stretching directions of vesicles. Newly acquired lidar of the Inyo Domes, including Obsidian Dome, is being analyzed to better understand the patterns of folding on the upper surface of the lavas, and to test for fold vergence patterns that may distinguish between endogenous and exogenous flow.

Explicit memory and implicit memory in occipital lobe stroke patients.

PubMed

Gong, Liang; Wang, JiHua; Feng, Lei; Wang, MeiHong; Li, Xiu; Hu, JiaYun; Wang, Kai

2015-03-01

Occipital stroke patients mainly showed cortical blindness and unilateral vision loss; memory is generally reserved. Recent reports from neuroimaging show the occipital lobe may be involved in the processing of implicit memory (IM), especially the perception type of IM processing. In this study, we explored the explicit memory (EM) and IM damage in occipital lobe stroke patients. A total of 25 occipital strokes and 29 years of age, educational level equivalent healthy controls (HCs), evaluated by using immediate recall, delayed recall, recognition for EM tasks, picture identification, and category exemplar generation for IM tasks. There was no significant difference between occipital stroke patients and HCs in EM tasks and category exemplar generation task. In the picture identification task, occipital lobe stroke group score was poorer than HC group, the results were statistically significant, but in the pictures identify rate, occipital stroke patients and normal control group had no significant difference. The occipital stroke patients may have IM damage, primarily damage the perception type of IM priming effects, which was unrelated with their cortical blindness. Copyright © 2015 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Uplift, Feedback, and Buoyancy: Radio Lobe Dynamics in NGC 4472

NASA Astrophysics Data System (ADS)

Gendron-Marsolais, M.; Kraft, R. P.; Bogdan, A.; Hlavacek-Larrondo, J.; Forman, W. R.; Jones, C.; Su, Y.; Nulsen, P.; Randall, S. W.; Roediger, E.

2017-10-01

We present results from deep (380 ks) Chandra observations of the active galactic nucleus (AGN) outburst in the massive early-type galaxy NGC 4472. We detect cavities in the gas coincident with the radio lobes and estimate the eastern and western lobe enthalpy to be (1.1+/- 0.5)× {10}56 erg and (3+/- 1)× {10}56 erg and the average power required to inflate the lobes to be (1.8+/- 0.9)× {10}41 erg s-1 and (6+/- 3)× {10}41 erg s-1, respectively. We also detect enhanced X-ray rims around the radio lobes with sharp surface brightness discontinuities between the shells and the ambient gas. The temperature of the gas in the shells is less than that of the ambient medium, suggesting that they are not AGN-driven shocks but rather gas uplifted from the core by the buoyant rise of the radio bubbles. We estimate the energy required to lift the gas to be up to (1.1+/- 0.3)× {10}56 erg and (3+/- 1)× {10}56 erg for the eastern and western rims, respectively, constituting a significant fraction of the total outburst energy. A more conservative estimate suggests that the gas in the rim was uplifted at a smaller distance, requiring only 20%-25% of this energy. In either case, if a significant fraction of this uplift energy is thermalized via hydrodynamic instabilities or thermal conduction, our results suggest that it could be an important source of heating in cool core clusters and groups. We also find evidence for a central abundance drop in NGC 4472. The iron abundance profile shows that the region along the cavity system has a lower metallicity than the surrounding undisturbed gas, similar to the central region. This also shows that bubbles have lifted low-metallicity gas from the center.

Neurodevelopmental profile of Fetal Alcohol Spectrum Disorder: A systematic review.

PubMed

Lange, Shannon; Rovet, Joanne; Rehm, Jürgen; Popova, Svetlana

2017-06-23

In an effort to improve the screening and diagnosis of individuals with Fetal Alcohol Spectrum Disorder (FASD), research has focused on the identification of a unique neurodevelopmental profile characteristic of this population. The objective of this review was to identify any existing neurodevelopmental profiles of FASD and review their classification function in order to identify gaps and limitations of the current literature. A systematic search for studies published up to the end of December 2016 reporting an identified neurodevelopmental profile of FASD was conducted using multiple electronic bibliographic databases. The search was not limited geographically or by language of publication. Original research published in a peer-reviewed journal that involved the evaluation of the classification function of an identified neurodevelopmental profile of FASD was included. Two approaches have been taken to determine the pathognomonic neurodevelopmental features of FASD, namely the utilization of i) behavioral observations/ratings by parents/caregivers and ii) subtest scores from standardized test batteries assessing a variety of neurodevelopmental domains. Both approaches show some promise, with the former approach (which is dominated by research on the Neurobehavioral Screening Tool) having good sensitivity (63% to 98%), but varying specificity (42% to 100%), and the latter approach having good specificity (72% to 96%), but varying sensitivity (60% to 88%). The current review revealed that research in this area remains limited and a definitive neurodevelopmental profile of FASD has not been established. However, the identification of a neurodevelopmental profile will aid in the accurate identification of individuals with FASD, by adding to the armamentarium of clinicians. The full review protocol is available in PROSPERO ( http://www.crd.york.ac.uk/PROSPERO/ ); registration number CRD42016039326; registered 20 May 2016.

Early seizures and temporal lobe trauma predict post-traumatic epilepsy: A longitudinal study.

PubMed

Tubi, Meral A; Lutkenhoff, Evan; Blanco, Manuel Buitrago; McArthur, David; Villablanca, Pablo; Ellingson, Benjamin; Diaz-Arrastia, Ramon; Van Ness, Paul; Real, Courtney; Shrestha, Vikesh; Engel, Jerome; Vespa, Paul M; Agoston, Denes; Au, Alicia; Bell, Michael J; Branch, Craig; Buitrago Blanco, Manuel; Bullock, Ross; Claassen, Jan; Clarke, Robert; Cloyd, James; Coles, Lisa; Crawford, Karen; Diaz-Arrastia, Ramon; Duncan, Dominique; Ellingson, Benjamin; Engel, Jerome; Foreman, Brandon; Galanopoulou, Aristea; Gilmore, Emily; Olli, Grohn; Harris, Neil; Hartings, Jed; Lawrence, Hirsch; Hunn, Martin; Jette, Nathalie; Johnston, Leigh; Jones, Nigel; Kanner, Andres; McArthur, David; Monti, Martin; Morokoff, Andrew; Moshe, Solomon; Mowrey, Wenzhu; Naughton, Tomas; O'Brien, Terence; O'Phelan, Kristine; Pitkanen, Asla; Raman, Rema; Robertson, Courtney; Rosenthal, Eric; Shultz, Sandy; Snutch, Terrance; Staba, Richard; Toga, Arthur; Van Horn, Jack; Vespa, Paul; Willyerd, Frederick; Zimmermann, Lara

2018-05-31

Injury severity after traumatic brain injury (TBI) is a well-established risk factor for the development of post-traumatic epilepsy (PTE). However, whether lesion location influences the susceptibility of seizures and development of PTE longitudinally has yet to be defined. We hypothesized that lesion location, specifically in the temporal lobe, would be associated with an increased incidence of both early seizures and PTE. As secondary analysis measures, we assessed the degree of brain atrophy and functional recovery, and performed a between-group analysis, comparing patients who developed PTE with those who did not develop PTE. We assessed early seizure incidence (n = 90) and longitudinal development of PTE (n = 46) in a prospective convenience sample of patients with moderate-severe TBI. Acutely, patients were monitored with prospective cEEG and a high-resolution Magnetic Resonance Imaging (MRI) scan for lesion location classification. Chronically, patients underwent a high-resolution MRI, clinical assessment, and were longitudinally monitored for development of epilepsy for a minimum of 2 years post-injury. Early seizures, occurring within the first week post-injury, occurred in 26.7% of the patients (n = 90). Within the cohort of subjects who had evidence of early seizures (n = 24), 75% had a hemorrhagic temporal lobe injury on admission. For longitudinal analyses (n = 46), 45.7% of patients developed PTE within a minimum of 2 years post-injury. Within the cohort of subjects who developed PTE (n = 21), 85.7% had a hemorrhagic temporal lobe injury on admission and 38.1% had early (convulsive or non-convulsive) seizures on cEEG monitoring during their acute ICU stay. In a between-group analysis, patients with PTE (n = 21) were more likely than patients who did not develop PTE (n = 25) to have a hemorrhagic temporal lobe injury (p < 0.001), worse functional recovery (p = 0.003), and greater temporal lobe atrophy (p = 0.029). Our results indicate that in a cohort of patients with a moderate-severe TBI, 1) lesion location specificity (e.g. the temporal lobe) is related to both a high incidence of early seizures and longitudinal development of PTE, 2) early seizures, whether convulsive or non-convulsive in nature, are associated with an increased risk for PTE development, and 3) patients who develop PTE have greater chronic temporal lobe atrophy and worse functional outcomes, compared to those who do not develop PTE, despite matched injury severity characteristics. This study provides the foundation for a future prospective study focused on elucidating the mechanisms and risk factors for epileptogenesis. Copyright © 2017. Published by Elsevier Inc.

Molecular identification and cluster analysis of homofermentative thermophilic lactobacilli isolated from dairy products.

PubMed

Andrighetto, C; De Dea, P; Lombardi, A; Neviani, E; Rossetti, L; Giraffa, G

1998-10-01

Twenty-five strains of thermophilic lactobacilli isolated from yoghurt and from semi-hard and hard cheeses (in parallel with nine type or reference strains) were identified and grouped according to their genetic relatedness. Strains were identified by sugar fermentation patterns using the "API 50 CHL" galleries, by species-specific DNA probes in dot-blot hybridization experiments, by amplification and restriction analysis of the 16S rRNA gene (ARDRA) and by polymerase chain reaction (PCR) using species-specific oligonucleotide primers. Strains were classified as Lactobacillus delbrueckii subsp. lactis and subsp. bulgaricus, L. helveticus, and L. acidophilus. Strains which were atypical by sugar fermentation patterns were also identified. Most of the strains could not be grouped using carbohydrate fermentation profiles. PCR fingerprinting was used to identify DNA profiles for the 25 lactobacilli. Experimentally obtained PCR profiles enabled discrimination of all strains, which were grouped according to the similarities in their combined patterns. In general, the clustering of the strains corresponded well with species delineation obtained by molecular identification. The dendrogram of genetic relatedness enabled the unambiguous identification of most of the strains which were shown to be atypical by the sugar fermentation profile, except for a discrepancy in one L. delbrueckii subsp. lactis strain and one atypical Lactobacillus sp. strain.

Deletion of OTX2 in neural ectoderm delays anterior pituitary development

PubMed Central

Mortensen, Amanda H.; Schade, Vanessa; Lamonerie, Thomas; Camper, Sally A.

2015-01-01

OTX2 is a homeodomain transcription factor that is necessary for normal head development in mouse and man. Heterozygosity for loss-of-function alleles causes an incompletely penetrant, haploinsufficiency disorder. Affected individuals exhibit a spectrum of features that range from developmental defects in eye and/or pituitary development to acephaly. To investigate the mechanism underlying the pituitary defects, we used different cre lines to inactivate Otx2 in early head development and in the prospective anterior and posterior lobes. Mice homozygous for Otx2 deficiency in early head development and pituitary oral ectoderm exhibit craniofacial defects and pituitary gland dysmorphology, but normal pituitary cell specification. The morphological defects mimic those observed in humans and mice with OTX2 heterozygous mutations. Mice homozygous for Otx2 deficiency in the pituitary neural ectoderm exhibited altered patterning of gene expression and ablation of FGF signaling. The posterior pituitary lobe and stalk, which normally arise from neural ectoderm, were extremely hypoplastic. Otx2 expression was intact in Rathke's pouch, the precursor to the anterior lobe, but the anterior lobe was hypoplastic. The lack of FGF signaling from the neural ectoderm was sufficient to impair anterior lobe growth, but not the differentiation of hormone-producing cells. This study demonstrates that Otx2 expression in the neural ectoderm is important intrinsically for the development of the posterior lobe and pituitary stalk, and it has significant extrinsic effects on anterior pituitary growth. Otx2 expression early in head development is important for establishing normal craniofacial features including development of the brain, eyes and pituitary gland. PMID:25315894

Autobiographical memory of the recent past following frontal cortex or temporal lobe excisions.

PubMed

Thaiss, Laila; Petrides, Michael

2008-08-01

Previous research has raised questions regarding the necessity of the frontal cortex in autobiographical memory and the role that it plays in actively retrieving contextual information associated with personally relevant events. Autobiographical memory was studied in patients with unilateral excisions restricted to the frontal cortex or temporal lobe involving the amygdalo-hippocampal region and in normal controls using an event-sampling method. We examined accuracy of free recall, use of strategies during retrieval and memory for specific aspects of the autobiographical events, including temporal order. Patients with temporal lobe excisions were impaired in autobiographical recall. By contrast, patients with frontal cortical excisions exhibited normal autobiographical recall but were less likely to use temporal order spontaneously to organize event retrieval. Instruction to organize retrieval by temporal order failed to improve recall in temporal lobe patients and increased the incidence of plausible intrusion errors in left temporal patients. In contrast, patients with frontal cortical excisions now surpassed control subjects in recall of autobiographical events. Furthermore, the retrieval accuracy for the temporal order of diary events was not impaired in these patients. In a subsequent cued recall test, temporal lobe patients were impaired in their memory for the details of the diary events and their context. In conclusion, a basic impairment in autobiographical memory (including memory for temporal context) results from damage to the temporal lobe and not the frontal cortex. Patients with frontal excisions fail to use organizational strategies spontaneously to aid retrieval but can use these effectively if instructed to do so.

Distinct patterns of brain atrophy in Genetic Frontotemporal Dementia Initiative (GENFI) cohort revealed by visual rating scales.

PubMed

Fumagalli, Giorgio G; Basilico, Paola; Arighi, Andrea; Bocchetta, Martina; Dick, Katrina M; Cash, David M; Harding, Sophie; Mercurio, Matteo; Fenoglio, Chiara; Pietroboni, Anna M; Ghezzi, Laura; van Swieten, John; Borroni, Barbara; de Mendonça, Alexandre; Masellis, Mario; Tartaglia, Maria C; Rowe, James B; Graff, Caroline; Tagliavini, Fabrizio; Frisoni, Giovanni B; Laforce, Robert; Finger, Elizabeth; Sorbi, Sandro; Scarpini, Elio; Rohrer, Jonathan D; Galimberti, Daniela

2018-05-24

In patients with frontotemporal dementia, it has been shown that brain atrophy occurs earliest in the anterior cingulate, insula and frontal lobes. We used visual rating scales to investigate whether identifying atrophy in these areas may be helpful in distinguishing symptomatic patients carrying different causal mutations in the microtubule-associated protein tau (MAPT), progranulin (GRN) and chromosome 9 open reading frame (C9ORF72) genes. We also analysed asymptomatic carriers to see whether it was possible to visually identify brain atrophy before the appearance of symptoms. Magnetic resonance imaging of 343 subjects (63 symptomatic mutation carriers, 132 presymptomatic mutation carriers and 148 control subjects) from the Genetic Frontotemporal Dementia Initiative study were analysed by two trained raters using a protocol of six visual rating scales that identified atrophy in key regions of the brain (orbitofrontal, anterior cingulate, frontoinsula, anterior and medial temporal lobes and posterior cortical areas). Intra- and interrater agreement were greater than 0.73 for all the scales. Voxel-based morphometric analysis demonstrated a strong correlation between the visual rating scale scores and grey matter atrophy in the same region for each of the scales. Typical patterns of atrophy were identified: symmetric anterior and medial temporal lobe involvement for MAPT, asymmetric frontal and parietal loss for GRN, and a more widespread pattern for C9ORF72. Presymptomatic MAPT carriers showed greater atrophy in the medial temporal region than control subjects, but the visual rating scales could not identify presymptomatic atrophy in GRN or C9ORF72 carriers. These simple-to-use and reproducible scales may be useful tools in the clinical setting for the discrimination of different mutations of frontotemporal dementia, and they may even help to identify atrophy prior to onset in those with MAPT mutations.

A diagnostic dilemma of right lower lobe collapse caused by pulmonary bilharsiasis.

PubMed

Sersar, Sameh Ibrahim; Abulmaaty, Reda Ahmed; Elnahas, Hala Ahmed; Moussa, Sherif Abdou; Shiha, Usama A; Ghafar, Wael A Abdel; Elmotawaly, Raed A

2006-02-01

A 32-year-old male was presented with massive haemoptysis. An urgent chest X-ray (Fig. 1a) and CT chest (Fig. 1b-e) was done revealing a right lower lobe consolidation collapse. An urgent rigid bronchoscopy was performed to localize the source of bleeding and try to control it. A right lower lobectomy was done using a double-lumen endotracheal tube. Preoperative and intraoperative impressions of non-specific inflammation were accused to be the aetiology. Histopathology revealed pulmonary venous congestion with bilharsial ova.

Parallel processing in the honeybee olfactory pathway: structure, function, and evolution.

PubMed

Rössler, Wolfgang; Brill, Martin F

2013-11-01

Animals face highly complex and dynamic olfactory stimuli in their natural environments, which require fast and reliable olfactory processing. Parallel processing is a common principle of sensory systems supporting this task, for example in visual and auditory systems, but its role in olfaction remained unclear. Studies in the honeybee focused on a dual olfactory pathway. Two sets of projection neurons connect glomeruli in two antennal-lobe hemilobes via lateral and medial tracts in opposite sequence with the mushroom bodies and lateral horn. Comparative studies suggest that this dual-tract circuit represents a unique adaptation in Hymenoptera. Imaging studies indicate that glomeruli in both hemilobes receive redundant sensory input. Recent simultaneous multi-unit recordings from projection neurons of both tracts revealed widely overlapping response profiles strongly indicating parallel olfactory processing. Whereas lateral-tract neurons respond fast with broad (generalistic) profiles, medial-tract neurons are odorant specific and respond slower. In analogy to "what-" and "where" subsystems in visual pathways, this suggests two parallel olfactory subsystems providing "what-" (quality) and "when" (temporal) information. Temporal response properties may support across-tract coincidence coding in higher centers. Parallel olfactory processing likely enhances perception of complex odorant mixtures to decode the diverse and dynamic olfactory world of a social insect.

Distinctive Structural and Effective Connectivity Changes of Semantic Cognition Network across Left and Right Mesial Temporal Lobe Epilepsy Patients.

PubMed

Fan, Xiaotong; Yan, Hao; Shan, Yi; Shang, Kun; Wang, Xiaocui; Wang, Peipei; Shan, Yongzhi; Lu, Jie; Zhao, Guoguang

2016-01-01

Occurrence of language impairment in mesial temporal lobe epilepsy (mTLE) patients is common and left mTLE patients always exhibit a primary problem with access to names. To explore different neuropsychological profiles between left and right mTLE patients, the study investigated both structural and effective functional connectivity changes within the semantic cognition network between these two groups and those from normal controls. We found that gray matter atrophy of left mTLE patients was more severe than that of right mTLE patients in the whole brain and especially within the semantic cognition network in their contralateral hemisphere. It suggested that seizure attacks were rather targeted than random for patients with hippocampal sclerosis (HS) in the dominant hemisphere. Functional connectivity analysis during resting state fMRI revealed that subregions of the anterior temporal lobe (ATL) in the left HS patients were no longer effectively connected. Further, we found that, unlike in right HS patients, increased causal linking between ipsilateral regions in the left HS epilepsy patients cannot make up for their decreased contralateral interaction. It suggested that weakened contralateral connection and disrupted effective interaction between subregions of the unitary, transmodal hub of the ATL may be the primary cause of anomia in the left HS patients.

Distinctive Structural and Effective Connectivity Changes of Semantic Cognition Network across Left and Right Mesial Temporal Lobe Epilepsy Patients

PubMed Central

Fan, Xiaotong; Shang, Kun; Wang, Xiaocui; Wang, Peipei; Shan, Yongzhi; Lu, Jie

2016-01-01

Occurrence of language impairment in mesial temporal lobe epilepsy (mTLE) patients is common and left mTLE patients always exhibit a primary problem with access to names. To explore different neuropsychological profiles between left and right mTLE patients, the study investigated both structural and effective functional connectivity changes within the semantic cognition network between these two groups and those from normal controls. We found that gray matter atrophy of left mTLE patients was more severe than that of right mTLE patients in the whole brain and especially within the semantic cognition network in their contralateral hemisphere. It suggested that seizure attacks were rather targeted than random for patients with hippocampal sclerosis (HS) in the dominant hemisphere. Functional connectivity analysis during resting state fMRI revealed that subregions of the anterior temporal lobe (ATL) in the left HS patients were no longer effectively connected. Further, we found that, unlike in right HS patients, increased causal linking between ipsilateral regions in the left HS epilepsy patients cannot make up for their decreased contralateral interaction. It suggested that weakened contralateral connection and disrupted effective interaction between subregions of the unitary, transmodal hub of the ATL may be the primary cause of anomia in the left HS patients. PMID:28018680

Face shape and face identity processing in behavioral variant fronto-temporal dementia: A specific deficit for familiarity and name recognition of famous faces.

PubMed

De Winter, François-Laurent; Timmers, Dorien; de Gelder, Beatrice; Van Orshoven, Marc; Vieren, Marleen; Bouckaert, Miriam; Cypers, Gert; Caekebeke, Jo; Van de Vliet, Laura; Goffin, Karolien; Van Laere, Koen; Sunaert, Stefan; Vandenberghe, Rik; Vandenbulcke, Mathieu; Van den Stock, Jan

2016-01-01

Deficits in face processing have been described in the behavioral variant of fronto-temporal dementia (bvFTD), primarily regarding the recognition of facial expressions. Less is known about face shape and face identity processing. Here we used a hierarchical strategy targeting face shape and face identity recognition in bvFTD and matched healthy controls. Participants performed 3 psychophysical experiments targeting face shape detection (Experiment 1), unfamiliar face identity matching (Experiment 2), familiarity categorization and famous face-name matching (Experiment 3). The results revealed group differences only in Experiment 3, with a deficit in the bvFTD group for both familiarity categorization and famous face-name matching. Voxel-based morphometry regression analyses in the bvFTD group revealed an association between grey matter volume of the left ventral anterior temporal lobe and familiarity recognition, while face-name matching correlated with grey matter volume of the bilateral ventral anterior temporal lobes. Subsequently, we quantified familiarity-specific and name-specific recognition deficits as the sum of the celebrities of which respectively only the name or only the familiarity was accurately recognized. Both indices were associated with grey matter volume of the bilateral anterior temporal cortices. These findings extent previous results by documenting the involvement of the left anterior temporal lobe (ATL) in familiarity detection and the right ATL in name recognition deficits in fronto-temporal lobar degeneration.

Superficial Temporal Artery-Superior Cerebellar Artery Bypass with Anterior Petrosectomy.

PubMed

Hokari, Masaaki; Asaoka, Katsuyuki; Shimbo, Daisuke; Uchida, Kazuki; Itamoto, Koji

2018-06-01

Superficial temporal artery (STA) to superior cerebellar artery (SCA) bypass is associated with a relatively high risk of surgical complications, such as hematoma and/or edema caused by temporal lobe retraction. Therefore, the right side is typically used to avoid retraction of the left temporal lobe. In this report, we present a case of left STA-SCA bypass with anterior petrosectomy to avoid retraction of dominant-side temporal lobe and describe the surgical technique in detail. A 69-year-old man presented with gradual worsening of dysarthria and gait disturbance. Magnetic resonance imaging showed no signs of acute infarction, but digital subtraction angiography showed severe stenosis of basilar artery and faint flow in the distal basilar artery. On 3-dimensional computed tomography angiography, posterior communicating arteries were not visualized; we could identify the left SCA, but not the right SCA. Despite dual antiplatelet therapy, a small fresh brainstem infarct was detected 10 days after admission. To avert fatal brainstem infarction and further enlargement of the infarct, we performed left STA-SCA bypass with anterior petrosectomy to avoid retraction of the dominant-side temporal lobe. Postoperative imaging revealed no new lesions, such as infarction or temporal lobe contusional hematoma, and confirmed the patency of the bypass. Postoperative single-photon emission computed tomography demonstrated improved cerebral blood flow in the posterior circulation. The patient was transferred to another hospital for rehabilitation. This method helps minimize the risk of injury to the temporal lobe, especially that of the dominant side. Copyright © 2018. Published by Elsevier Inc.

Architecture and emplacement of flood basalt flow fields: case studies from the Columbia River Basalt Group, NW USA

NASA Astrophysics Data System (ADS)

Vye-Brown, C.; Self, S.; Barry, T. L.

2013-03-01

The physical features and morphologies of collections of lava bodies emplaced during single eruptions (known as flow fields) can be used to understand flood basalt emplacement mechanisms. Characteristics and internal features of lava lobes and whole flow field morphologies result from the forward propagation, radial spread, and cooling of individual lobes and are used as a tool to understand the architecture of extensive flood basalt lavas. The features of three flood basalt flow fields from the Columbia River Basalt Group are presented, including the Palouse Falls flow field, a small (8,890 km2, ˜190 km3) unit by common flood basalt proportions, and visualized in three dimensions. The architecture of the Palouse Falls flow field is compared to the complex Ginkgo and more extensive Sand Hollow flow fields to investigate the degree to which simple emplacement models represent the style, as well as the spatial and temporal developments, of flow fields. Evidence from each flow field supports emplacement by inflation as the predominant mechanism producing thick lobes. Inflation enables existing lobes to transmit lava to form new lobes, thus extending the advance and spread of lava flow fields. Minimum emplacement timescales calculated for each flow field are 19.3 years for Palouse Falls, 8.3 years for Ginkgo, and 16.9 years for Sand Hollow. Simple flow fields can be traced from vent to distal areas and an emplacement sequence visualized, but those with multiple-layered lobes present a degree of complexity that make lava pathways and emplacement sequences more difficult to identify.

Wind-driven angular momentum loss in binary systems. I - Ballistic case

NASA Technical Reports Server (NTRS)

Brookshaw, Leigh; Tavani, Marco

1993-01-01

We study numerically the average loss of specific angular momentum from binary systems due to mass outflow from one of the two stars for a variety of initial injection geometries and wind velocities. We present results of ballistic calculations in three dimensions for initial mass ratios q of the mass-losing star to primary star in the range q between 10 exp -5 and 10. We consider injection surfaces close to the Roche lobe equipotential surface of the mass-losing star, and also cases with the mass-losing star underfilling its Roche lobe. We obtain that the orbital period is expected to have a negative time derivative for wind-driven secular evolution of binaries with q greater than about 3 and with the mass-losing star near filling its Roche lobe. We also study the effect of the presence of an absorbing surface approximating an accretion disk on the average final value of the specific angular momentum loss. We find that the effect of an accretion disk is to increase the wind-driven angular momentum loss. Our results are relevant for evolutionary models of high-mass binaries and low-mass X-ray binaries.

Performance on the Frontal Assessment Battery is sensitive to frontal lobe damage in stroke patients.

PubMed

Kopp, Bruno; Rösser, Nina; Tabeling, Sandra; Stürenburg, Hans Jörg; de Haan, Bianca; Karnath, Hans-Otto; Wessel, Karl

2013-11-16

The Frontal Assessment Battery (FAB) is a brief battery of six neuropsychological tasks designed to assess frontal lobe function at bedside [Neurology 55:1621-1626, 2000]. The six FAB tasks explore cognitive and behavioral domains that are thought to be under the control of the frontal lobes, most notably conceptualization and abstract reasoning, lexical verbal fluency and mental flexibility, motor programming and executive control of action, self-regulation and resistance to interference, inhibitory control, and environmental autonomy. We examined the sensitivity of performance on the FAB to frontal lobe damage in right-hemisphere-damaged first-ever stroke patients based on voxel-based lesion-behavior mapping. Voxel-based lesion-behavior mapping of FAB performance revealed that the integrity of the right anterior insula (BA13) is crucial for the FAB global composite score, for the FAB conceptualization score, as well as for the FAB inhibitory control score. Furthermore, the FAB conceptualization and mental flexibility scores were sensitive to damage of the right middle frontal gyrus (MFG; BA9). Finally, the FAB inhibitory control score was sensitive to damage of the right inferior frontal gyrus (IFG; BA44/45). These findings indicate that several FAB scores (including composite and item scores) provide valid measures of right hemispheric lateral frontal lobe dysfunction, specifically of focal lesions near the anterior insula, in the MFG and in the IFG.

Performance on the Frontal Assessment Battery is sensitive to frontal lobe damage in stroke patients

PubMed Central

2013-01-01

Background The Frontal Assessment Battery (FAB) is a brief battery of six neuropsychological tasks designed to assess frontal lobe function at bedside [Neurology 55:1621-1626, 2000]. The six FAB tasks explore cognitive and behavioral domains that are thought to be under the control of the frontal lobes, most notably conceptualization and abstract reasoning, lexical verbal fluency and mental flexibility, motor programming and executive control of action, self-regulation and resistance to interference, inhibitory control, and environmental autonomy. Methods We examined the sensitivity of performance on the FAB to frontal lobe damage in right-hemisphere-damaged first-ever stroke patients based on voxel-based lesion-behavior mapping. Results Voxel-based lesion-behavior mapping of FAB performance revealed that the integrity of the right anterior insula (BA13) is crucial for the FAB global composite score, for the FAB conceptualization score, as well as for the FAB inhibitory control score. Furthermore, the FAB conceptualization and mental flexibility scores were sensitive to damage of the right middle frontal gyrus (MFG; BA9). Finally, the FAB inhibitory control score was sensitive to damage of the right inferior frontal gyrus (IFG; BA44/45). Conclusions These findings indicate that several FAB scores (including composite and item scores) provide valid measures of right hemispheric lateral frontal lobe dysfunction, specifically of focal lesions near the anterior insula, in the MFG and in the IFG. PMID:24237624

Formation of the Dayside Magnetopause and Its Boundary Layers Under the Radial IMF

NASA Astrophysics Data System (ADS)

Pi, Gilbert; Němeček, Zdeněk.; Å afránková, Jana; Grygorov, Kostiantyn; Shue, Jih-Hong

2018-05-01

The global structure of magnetopause boundary layers under the radial interplanetary magnetic field (IMF) conditions is studied by a comparison of experimental and simulation results. In magnetohydrodynamic simulations, the hemispherical asymmetry of the reconnection locations was found. The draped field adjacent to the magnetopause points northward in the Northern Hemisphere, but it is oriented southward in the Southern Hemisphere at the beginning of the simulation for negative IMF Bx. The magnetopause region affected by the positive IMF Bz component enlarges over time, and the density profile exhibit a north-south asymmetry near the magnetopause. The experimental part of the study uses the Time History of Events and Macroscale Interactions during Substorm data. We analyze profiles of the plasma parameters and magnetic field as well as the ion pitch-angle distributions. The nonsimultaneous appearance of parallel and antiparallel aligned flows suggests two spatially separated sources of these flows. We have identified (1) the inner part of the low-latitude boundary layer (LLBL) on closed magnetic field lines; (2) the outer LLBL on open field lines; (3) the inner part of the magnetosheath boundary layer (MSBL) formed by dayside reconnection in the Southern Hemisphere; and (4) the outer MSBL resulting from lobe reconnection in the Northern Hemisphere.

Motor Speech Phenotypes of Frontotemporal Dementia, Primary Progressive Aphasia, and Progressive Apraxia of Speech.

PubMed

Poole, Matthew L; Brodtmann, Amy; Darby, David; Vogel, Adam P

2017-04-14

Our purpose was to create a comprehensive review of speech impairment in frontotemporal dementia (FTD), primary progressive aphasia (PPA), and progressive apraxia of speech in order to identify the most effective measures for diagnosis and monitoring, and to elucidate associations between speech and neuroimaging. Speech and neuroimaging data described in studies of FTD and PPA were systematically reviewed. A meta-analysis was conducted for speech measures that were used consistently in multiple studies. The methods and nomenclature used to describe speech in these disorders varied between studies. Our meta-analysis identified 3 speech measures which differentiate variants or healthy control-group participants (e.g., nonfluent and logopenic variants of PPA from all other groups, behavioral-variant FTD from a control group). Deficits within the frontal-lobe speech networks are linked to motor speech profiles of the nonfluent variant of PPA and progressive apraxia of speech. Motor speech impairment is rarely reported in semantic and logopenic variants of PPA. Limited data are available on motor speech impairment in the behavioral variant of FTD. Our review identified several measures of speech which may assist with diagnosis and classification, and consolidated the brain-behavior associations relating to speech in FTD, PPA, and progressive apraxia of speech.

Auditory brainstem response (ABR) profiling tests as diagnostic support for schizophrenia and adult attention-deficit hyperactivity disorder (ADHD).

PubMed

Juselius Baghdassarian, Eva; Nilsson Markhed, Maria; Lindström, Eva; Nilsson, Björn M; Lewander, Tommy

2018-06-01

To evaluate the performances of two auditory brainstem response (ABR) profiling tests as potential biomarkers and diagnostic support for schizophrenia and adult attention-deficit hyperactivity disorder (ADHD), respectively, in an investigator-initiated blinded study design. Male and female patients with schizophrenia (n=26) and adult ADHD (n=24) meeting Diagnostic and Statistical Manual of Mental Disorders Fourth Edition (DSM IV) diagnostic criteria and healthy controls (n=58) comprised the analysis set (n=108) of the total number of study participants (n=119). Coded sets of randomized ABR recordings were analysed by an independent party blinded to clinical diagnoses before a joint code-breaking session. The ABR profiling test for schizophrenia identified schizophrenia patients versus controls with a sensitivity of 84.6% and a specificity of 93.1%. The ADHD test identified patients with adult ADHD versus controls with a sensitivity of 87.5% and a specificity of 91.4%. The ABR profiling tests discriminated schizophrenia and ADHD versus healthy controls with high sensitivity and specificity. The methods deserve to be further explored in larger clinical studies including a broad range of psychiatric disorders to determine their utility as potential diagnostic biomarkers.

Dorsolateral frontal lobe epilepsy.

PubMed

Lee, Ricky W; Worrell, Greg A

2012-10-01

Dorsolateral frontal lobe seizures often present as a diagnostic challenge. The diverse semiologies may not produce lateralizing or localizing signs and can appear bizarre and suggest psychogenic events. Unfortunately, scalp electroencephalographic (EEG) and magnetic resonance imaging (MRI) are often unsatisfactory. It is not uncommon that these traditional diagnostic studies are either unhelpful or even misleading. In some cases, SPECT and positron emission tomography imaging can be an effective tool to identify the origin of seizures. However, these techniques and other emerging techniques all have limitations, and new approaches are needed to improve source localization.

The CF-Sputum Induction Trial (CF-SpIT) to assess lower airway bacterial sampling in young children with cystic fibrosis: a prospective internally controlled interventional trial.

PubMed

Ronchetti, Katherine; Tame, Jo-Dee; Paisey, Christopher; Thia, Lena P; Doull, Iolo; Howe, Robin; Mahenthiralingam, Eshwar; Forton, Julian T

2018-06-01

Pathogen surveillance is challenging but crucial in children with cystic fibrosis-who are often non-productive of sputum even if actively coughing-because infection and lung disease begin early in life. The role of sputum induction as a diagnostic tool for infection has not previously been systematically addressed in young children with cystic fibrosis. We aimed to assess the pathogen yield from sputum induction compared with that from cough swab and single-lobe, two-lobe, and six-lobe bronchoalveolar lavage. This prospective internally controlled interventional trial was done at the Children's Hospital for Wales (Cardiff, UK) in children with cystic fibrosis aged between 6 months and 18 years. Samples from cough swab, sputum induction, and single-lobe, two-lobe, and six-lobe bronchoalveolar lavage were matched for within-patient comparisons. Primary outcomes were comparative pathogen yield between sputum induction and cough swab for stage 1, and between sputum induction, and single-lobe, two-lobe, and six-lobe bronchoalveolar lavage for stage 2. Data were analysed as per protocol. This study is registered with the UK Clinical Research Network (14615) and with the International Standard Randomised Controlled Trial Network Registry (12473810). Between Jan 23, 2012, and July 4, 2017, 124 patients were prospectively recruited to the trial and had 200 sputum induction procedures for stage 1. 167 (84%) procedures were successful and the procedure was well tolerated. Of the 167 paired samples, 63 (38%) sputum-induction samples were pathogen positive compared with 24 (14%) cough swabs (p<0·0001; odds ratio [OR] 7·5; 95% CI 3·19-17·98). More pathogens were isolated from sputum induction than cough swab (79 [92%] of 86 vs 27 [31%] of 86; p<0·0001). For stage 2, 35 patients had a total of 41 paired sputum-induction and bronchoalveolar lavage procedures. Of the 41 paired samples, 28 (68%) were positive for at least one of the concurrent samples. 39 pathogens were isolated. Sputum induction identified 27 (69%) of the 39 pathogens, compared with 22 (56%; p=0·092; OR 3·3, 95% CI 0·91-12·11) on single-lobe, 28 (72%; p=1·0; OR 1·1, 95% CI 0·41-3·15) on two-lobe, and 33 (85%; p=0·21; OR 2·2, 95% CI 0·76-6·33) on six-lobe bronchoalveolar lavage. Sputum induction is superior to cough swab for pathogen detection, is effective at sampling the lower airway, and is a credible surrogate for bronchoalveolar lavage in symptomatic children. A substantial number of bronchoscopies could be avoided if sputum induction is done first and pathogens are appropriately treated. Both sputum induction and six-lobe bronchoalveolar lavage provide independent, sizeable gains in pathogen detection compared with the current gold-standard two-lobe bronchoalveolar lavage. We propose that sputum induction and six-lobe bronchoalveolar lavage combined are used as standard of care for comprehensive lower airway pathogen detection in children with cystic fibrosis. Health and Care Research Wales-Academic Health Science Collaboration and Wellcome Trust Institutional Strategic Support Fund. Copyright © 2018 The Author(s). Published by Elsevier Ltd. Open Access article under the CC BY 4.0 license. Published by Elsevier Ltd.. All rights reserved.

Pediatric Temporal Lobe Epilepsy Surgery in Bonn and Review of the Literature.

PubMed

Ormond, D Ryan; Clusmann, Hans; Sassen, Robert; Hoppe, Christian; Helmstaedter, Christoph; Schramm, Johannes; Grote, Alexander

2018-04-13

Epilepsy surgery is well established as safe and successful for children with temporal lobe epilepsy (TLE). Despite evidence from available data, there remains some reluctance to refer children with medically refractory epilepsy for preoperative evaluation and workup for possible surgery. To present the largest case series of pediatric (TLE) patients thus far, in order to better understand the predictability of preoperative evaluation on seizure outcome, and to better understand longitudinal outcomes in a large pediatric cohort. One hundred eighty-three pediatric patients with TLE who underwent surgical treatment between 1988 and 2012 were retrospectively reviewed. Preoperative seizure history, noninvasive and invasive preoperative evaluation, surgical results, pathological results, long-term seizure outcomes, and complications were evaluated. A review of pediatric TLE in the literature was also undertaken to better understand reported complications and long-term outcomes. Mean follow-up was 42 mo (range 12-152 mo); 155 patients had good seizure outcomes (Engel I/II; 84.8%) and 28 patients had poor seizure outcomes (Engel III/IV; 15.2%); 145 patients were Engel I (78.8%). Only 10 patients did not have worthwhile improvement (Engel class IV; 5.4%). A review of the literature identified 2089 unique cases of pediatric TLE. Satisfactory seizure outcomes occurred in 1629 patients (79%) with unsatisfactory outcomes in 433 patients (21%). Pediatric patients benefit from surgery for medically refractory TLE with an acceptable safety profile regardless of histopathological diagnosis, seizure frequency, or seizure type. Seizure freedom appears to have extensive durability in a significant proportion of surgically treated patients.

Phased-Array Study of Dual-Flow Jet Noise: Effect of Nozzles and Mixers

NASA Technical Reports Server (NTRS)

Soo Lee, Sang; Bridges, James

2006-01-01

A 16-microphone linear phased-array installed parallel to the jet axis and a 32-microphone azimuthal phased-array installed in the nozzle exit plane have been applied to identify the noise source distributions of nozzle exhaust systems with various internal mixers (lobed and axisymmetric) and nozzles (three different lengths). Measurements of velocity were also obtained using cross-stream stereo particle image velocimetry (PIV). Among the three nozzle lengths tested, the medium length nozzle was the quietest for all mixers at high frequency on the highest speed flow condition. Large differences in source strength distributions between nozzles and mixers occurred at or near the nozzle exit for this flow condition. The beamforming analyses from the azimuthal array for the 12-lobed mixer on the highest flow condition showed that the core flow and the lobe area were strong noise sources for the long and short nozzles. The 12 noisy spots associated with the lobe locations of the 12-lobed mixer with the long nozzle were very well detected for the frequencies 5 KHz and higher. Meanwhile, maps of the source strength of the axisymmetric splitter show that the outer shear layer was the most important noise source at most flow conditions. In general, there was a good correlation between the high turbulence regions from the PIV tests and the high noise source regions from the phased-array measurements.

THE COMPLEX NORTH TRANSITION REGION OF CENTAURUS A: RADIO STRUCTURE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Neff, Susan G.; Eilek, Jean A.; Owen, Frazer N., E-mail: susan.g.neff@nasa.gov

2015-04-01

We present deep radio images of the inner ∼50 kpc of Centaurus A, taken with the Karl G. Jansky Very Large Array at 90 cm. We focus on the Transition Regions between the inner galaxy—including the active nucleus, inner radio lobes, and star-forming disk—and the outer radio lobes. We detect previously unknown extended emission around the Inner Lobes, including radio emission from the star-forming disk. We find that the radio-loud part of the North Transition Region (NTR), known as the North Middle Lobe, is significantly overpressured relative to the surrounding interstellar medium. We see no evidence for a collimated flow from themore » active galactic nucleus through this region. Our images show that the structure identified by Morganti et al. as a possible large-scale jet appears to be part of a narrow ridge of emission within the broader, diffuse, radio-loud region. This knotty radio ridge is coincident with other striking phenomena: compact X-ray knots, ionized gas filaments, and streams of young stars. Several short-lived phenomena in the NTR, as well as the frequent re-energization required by the Outer Lobes, suggest that energy must be flowing through both Transition Regions at the present epoch. We suggest that the energy flow is in the form of a galactic wind.« less

Altered functional connectivity in early Alzheimer's disease: a resting-state fMRI study.

PubMed

Wang, Kun; Liang, Meng; Wang, Liang; Tian, Lixia; Zhang, Xinqing; Li, Kuncheng; Jiang, Tianzi

2007-10-01

Previous studies have led to the proposal that patients with Alzheimer's disease (AD) may have disturbed functional connectivity between different brain regions. Furthermore, recent resting-state functional magnetic resonance imaging (fMRI) studies have also shown that low-frequency (<0.08 Hz) fluctuations (LFF) of the blood oxygenation level-dependent signals were abnormal in several brain areas of AD patients. However, few studies have investigated disturbed LFF connectivity in AD patients. By using resting-state fMRI, this study sought to investigate the abnormal functional connectivities throughout the entire brain of early AD patients, and analyze the global distribution of these abnormalities. For this purpose, the authors divided the whole brain into 116 regions and identified abnormal connectivities by comparing the correlation coefficients of each pair. Compared with healthy controls, AD patients had decreased positive correlations between the prefrontal and parietal lobes, but increased positive correlations within the prefrontal lobe, parietal lobe, and occipital lobe. The AD patients also had decreased negative correlations (closer to zero) between two intrinsically anti-correlated networks that had previously been found in the resting brain. By using resting-state fMRI, our results supported previous studies that have reported an anterior-posterior disconnection phenomenon and increased within-lobe functional connectivity in AD patients. In addition, the results also suggest that AD may disturb the correlation/anti-correlation effect in the two intrinsically anti-correlated networks. Wiley-Liss, Inc.

Naming and recognizing famous faces in temporal lobe epilepsy.

PubMed

Glosser, G; Salvucci, A E; Chiaravalloti, N D

2003-07-08

To assess naming and recognition of faces of familiar famous people in patients with epilepsy before and after anterior temporal lobectomy (ATL). Color photographs of famous people were presented for naming and description to 63 patients with temporal lobe epilepsy (TLE) either before or after ATL and to 10 healthy age- and education-matched controls. Spontaneous naming of photographed famous people was impaired in all patient groups, but was most abnormal in patients who had undergone left ATL. When allowed to demonstrate knowledge of the famous faces through verbal descriptions, rather than naming, patients with left TLE, left ATL, and right TLE improved to normal levels, but patients with right ATL were still impaired, suggesting a new deficit in identifying famous faces. Naming of famous people was related to naming of other common objects, verbal memory, and perceptual discrimination of faces. Recognition of the identity of pictured famous people was more related to visuospatial perception and memory. Lesions in anterior regions of the right temporal lobe impair recognition of the identities of familiar faces, as well as the learning of new faces. Lesions in the left temporal lobe, especially in anterior regions, disrupt access to the names of known people, but do not affect recognition of the identities of famous faces. Results are consistent with the hypothesized role of lateralized anterior temporal lobe structures in facial recognition and naming of unique entities.

Profiles of Reactivity in Cocaine-Exposed Children

PubMed Central

Schuetze, Pamela; Molnar, Danielle S.; Eiden, Rina D.

2012-01-01

This study explored the possibility that specific, theoretically consistent profiles of reactivity could be identified in a sample of cocaine-exposed infants and whether these profiles were associated with a range of infant and/or maternal characteristics. Cluster analysis was used to identify distinct groups of infants based on physiological, behavioral and maternal reported measures of reactivity. Five replicable clusters were identified which corresponded to 1) Dysregulated/High Maternal Report Reactors, 2) Low Behavioral Reactors, 3) High Reactors, 4) Optimal Reactors and 5) Dysregulated/Low Maternal Report Reactors. These clusters were associated with differences in prenatal cocaine exposure status, birthweight, maternal depressive symptoms, and maternal negative affect during mother-infant interactions. These results support the presence of distinct reactivity profiles among high risk infants recruited on the basis of prenatal cocaine exposure and demographically similar control group infants not exposed to cocaine. PMID:23204615

A high resolution computer tomography scoring system to predict culture-positive pulmonary tuberculosis in the emergency department.

PubMed

Yeh, Jun-Jun; Neoh, Choo-Aun; Chen, Cheng-Ren; Chou, Christine Yi-Ting; Wu, Ming-Ting

2014-01-01

This study evaluated the use of high-resolution computed tomography (HRCT) to predict the presence of culture-positive pulmonary tuberculosis (PTB) in adult patients with pulmonary lesions in the emergency department (ED). The study included a derivation phase and validation phase with a total of 8,245 patients with pulmonary disease. There were 132 patients with culture-positive PTB in the derivation phase and 147 patients with culture-positive PTB in the validation phase. Imaging evaluation of pulmonary lesions included morphology and segmental distribution. The post-test probability ratios between both phases in three prevalence areas were analyzed. In the derivation phase, a multivariate analysis model identified cavitation, consolidation, and clusters/nodules in right or left upper lobe (except anterior segment) and consolidation of the superior segment of the right or left lower lobe as independent positive factors for culture-positive PTB, while consolidation of the right or left lower lobe (except superior segment) were independent negative factors. An ideal cutoff point based on the receiver operating characteristic (ROC) curve analysis was obtained at a score of 1. The sensitivity, specificity, positivity predictive value, and negative predictive value from derivation phase were 98.5% (130/132), 99.7% (3997/4008), 92.2% (130/141), and 99.9% (3997/3999). Based on the predicted positive likelihood ratio value of 328.33 in derivation phase, the post-test probability was observed to be 91.5% in the derivation phase, 92.5% in the validation phase, 94.5% in a high TB prevalence area, 91.0% in a moderate prevalence area, and 76.8% in moderate-to-low prevalence area. Our model using HRCT, which is feasible to perform in the ED, can promptly diagnose culture-positive PTB in moderate and moderate-to-low prevalence areas.

New Learning of Music after Bilateral Medial Temporal Lobe Damage: Evidence from an Amnesic Patient

PubMed Central

Valtonen, Jussi; Gregory, Emma; Landau, Barbara; McCloskey, Michael

2014-01-01

Damage to the hippocampus impairs the ability to acquire new declarative memories, but not the ability to learn simple motor tasks. An unresolved question is whether hippocampal damage affects learning for music performance, which requires motor processes, but in a cognitively complex context. We studied learning of novel musical pieces by sight-reading in a newly identified amnesic, LSJ, who was a skilled amateur violist prior to contracting herpes simplex encephalitis. LSJ has suffered virtually complete destruction of the hippocampus bilaterally, as well as extensive damage to other medial temporal lobe structures and the left anterior temporal lobe. Because of LSJ’s rare combination of musical training and near-complete hippocampal destruction, her case provides a unique opportunity to investigate the role of the hippocampus for complex motor learning processes specifically related to music performance. Three novel pieces of viola music were composed and closely matched for factors contributing to a piece’s musical complexity. LSJ practiced playing two of the pieces, one in each of the two sessions during the same day. Relative to a third unpracticed control piece, LSJ showed significant pre- to post-training improvement for the two practiced pieces. Learning effects were observed both with detailed analyses of correctly played notes, and with subjective whole-piece performance evaluations by string instrument players. The learning effects were evident immediately after practice and 14 days later. The observed learning stands in sharp contrast to LSJ’s complete lack of awareness that the same pieces were being presented repeatedly, and to the profound impairments she exhibits in other learning tasks. Although learning in simple motor tasks has been previously observed in amnesic patients, our results demonstrate that non-hippocampal structures can support complex learning of novel musical sequences for music performance. PMID:25232312

Dopamine- and Tyrosine Hydroxylase-Immunoreactive Neurons in the Brain of the American Cockroach, Periplaneta americana

PubMed Central

Hamanaka, Yoshitaka; Minoura, Run; Nishino, Hiroshi; Miura, Toru; Mizunami, Makoto

2016-01-01

The catecholamine dopamine plays several vital roles in the central nervous system of many species, but its neural mechanisms remain elusive. Detailed neuroanatomical characterization of dopamine neurons is a prerequisite for elucidating dopamine’s actions in the brain. In the present study, we investigated the distribution of dopaminergic neurons in the brain of the American cockroach, Periplaneta americana, using two antisera: 1) an antiserum against dopamine, and 2) an antiserum against tyrosine hydroxylase (TH, an enzyme required for dopamine synthesis), and identified about 250 putatively dopaminergic neurons. The patterns of dopamine- and TH-immunoreactive neurons were strikingly similar, suggesting that both antisera recognize the same sets of “dopaminergic” neurons. The dopamine and TH antibodies intensively or moderately immunolabeled prominent brain neuropils, e.g. the mushroom body (memory center), antennal lobe (first-order olfactory center) and central complex (motor coordination center). All subdivisions of the mushroom body exhibit both dopamine and TH immunoreactivity. Comparison of immunolabeled neurons with those filled by dye injection revealed that a group of immunolabeled neurons with cell bodies near the calyx projects into a distal region of the vertical lobe, which is a plausible site for olfactory memory formation in insects. In the antennal lobe, ordinary glomeruli as well as macroglomeruli exhibit both dopamine and TH immunoreactivity. It is noteworthy that the dopamine antiserum labeled tiny granular structures inside the glomeruli whereas the TH antiserum labeled processes in the marginal regions of the glomeruli, suggesting a different origin. In the central complex, all subdivisions excluding part of the noduli and protocerebral bridge exhibit both dopamine and TH immunoreactivity. These anatomical findings will accelerate our understanding of dopaminergic systems, specifically in neural circuits underlying aversive memory formation and arousal, in insects. PMID:27494326

Multimodal data and machine learning for surgery outcome prediction in complicated cases of mesial temporal lobe epilepsy.

PubMed

Memarian, Negar; Kim, Sally; Dewar, Sandra; Engel, Jerome; Staba, Richard J

2015-09-01

This study sought to predict postsurgical seizure freedom from pre-operative diagnostic test results and clinical information using a rapid automated approach, based on supervised learning methods in patients with drug-resistant focal seizures suspected to begin in temporal lobe. We applied machine learning, specifically a combination of mutual information-based feature selection and supervised learning classifiers on multimodal data, to predict surgery outcome retrospectively in 20 presurgical patients (13 female; mean age±SD, in years 33±9.7 for females, and 35.3±9.4 for males) who were diagnosed with mesial temporal lobe epilepsy (MTLE) and subsequently underwent standard anteromesial temporal lobectomy. The main advantage of the present work over previous studies is the inclusion of the extent of ipsilateral neocortical gray matter atrophy and spatiotemporal properties of depth electrode-recorded seizures as training features for individual patient surgery planning. A maximum relevance minimum redundancy (mRMR) feature selector identified the following features as the most informative predictors of postsurgical seizure freedom in this study's sample of patients: family history of epilepsy, ictal EEG onset pattern (positive correlation with seizure freedom), MRI-based gray matter thickness reduction in the hemisphere ipsilateral to seizure onset, proportion of seizures that first appeared in ipsilateral amygdala to total seizures, age, epilepsy duration, delay in the spread of ipsilateral ictal discharges from site of onset, gender, and number of electrode contacts at seizure onset (negative correlation with seizure freedom). Using these features in combination with a least square support vector machine (LS-SVM) classifier compared to other commonly used classifiers resulted in very high surgical outcome prediction accuracy (95%). Supervised machine learning using multimodal compared to unimodal data accurately predicted postsurgical outcome in patients with atypical MTLE. Published by Elsevier Ltd.

Demonstration of vesicular glutamate transporter-1 in corticotroph cells in the anterior pituitary of the rat.

PubMed

Kocsis, Zsuzsa S; Molnár, Csilla S; Watanabe, Masahiko; Daneels, Guy; Moechars, Dieder; Liposits, Zsolt; Hrabovszky, Erik

2010-02-01

Recent immunohistochemical studies of the rat adenohypophysis identified type-2 vesicular glutamate transporter (VGLUT2), a marker for glutamatergic neuronal phenotype, in high percentages of adenohypophysial gonadotrophs and thyrotrophs. The presence and molecular identity of amino acid neurotransmitters in the remaining hormone producing cell types are unknown. In the present study we addressed the putative synthesis of another glutamatergic marker, VGLUT1 by adenohypophysial cells. Immunohistochemical studies revealed VGLUT1 immunoreactivity in a small subset of polygonal medium-sized cells in the anterior lobe. Western blot analysis revealed a single major 60 kDa protein band in the adenohypophysis. Furthermore, the expression of VGLUT1 mRNA was confirmed by reverse transcription-polymerase chain reaction followed by sequence analysis of the amplicon. In contrast with rats which only showed VGLUT1 signal in the anterior lobe of the pituitary, mice contained high levels of VGLUT1 immunoreactivity in the intermediate, in addition to the anterior lobe. No signal was present in VGLUT1-knockout mice, providing evidence for specificity. In rats, results of colocalization studies with dual-immunofluorescent labeling provided evidence for VGLUT1 immunoreactivity in 45.9% of corticotrophs and 7.7% of luteinizing hormone beta-immunopositive gonadotrophs. Cells of the other peptide hormone phenotypes were devoid of VGLUT1 signal. A few cells in the adenohypophysis expressed both VGLUT1 and VGLUT2 immunoreactivities. The presence of the glutamate markers VGLUT1 and VGLUT2 in distinct populations of peptide hormone-secreting hypophysial cells highly indicates the involvement of endogenous glutamate release in autocrine/paracrine regulatory mechanisms. The biological function of adenohypophysial glutamate will require clarification. Copyright (c) 2009 Elsevier Ltd. All rights reserved.

Music Recognition in Frontotemporal Lobar Degeneration and Alzheimer Disease

PubMed Central

Johnson, Julene K; Chang, Chiung-Chih; Brambati, Simona M; Migliaccio, Raffaella; Gorno-Tempini, Maria Luisa; Miller, Bruce L; Janata, Petr

2013-01-01

Objective To compare music recognition in patients with frontotemporal dementia, semantic dementia, Alzheimer disease, and controls and to evaluate the relationship between music recognition and brain volume. Background Recognition of familiar music depends on several levels of processing. There are few studies about how patients with dementia recognize familiar music. Methods Subjects were administered tasks that assess pitch and melody discrimination, detection of pitch errors in familiar melodies, and naming of familiar melodies. Results There were no group differences on pitch and melody discrimination tasks. However, patients with semantic dementia had considerable difficulty naming familiar melodies and also scored the lowest when asked to identify pitch errors in the same melodies. Naming familiar melodies, but not other music tasks, was strongly related to measures of semantic memory. Voxel-based morphometry analysis of brain MRI showed that difficulty in naming songs was associated with the bilateral temporal lobes and inferior frontal gyrus, whereas difficulty in identifying pitch errors in familiar melodies correlated with primarily the right temporal lobe. Conclusions The results support a view that the anterior temporal lobes play a role in familiar melody recognition, and that musical functions are affected differentially across forms of dementia. PMID:21617528

Physiogenomic analysis of localized FMRI brain activity in schizophrenia.

PubMed

Windemuth, Andreas; Calhoun, Vince D; Pearlson, Godfrey D; Kocherla, Mohan; Jagannathan, Kanchana; Ruaño, Gualberto

2008-06-01

The search for genetic factors associated with disease is complicated by the complexity of the biological pathways linking genotype and phenotype. This analytical complexity is particularly concerning in diseases historically lacking reliable diagnostic biological markers, such as schizophrenia and other mental disorders. We investigate the use of functional magnetic resonance imaging (fMRI) as an intermediate phenotype (endophenotype) to identify physiogenomic associations to schizophrenia. We screened 99 subjects, 30 subjects diagnosed with schizophrenia, 13 unaffected relatives of schizophrenia patients, and 56 unrelated controls, for gene polymorphisms associated with fMRI activation patterns at two locations in temporal and frontal lobes previously implied in schizophrenia. A total of 22 single nucleotide polymorphisms (SNPs) in 15 genes from the dopamine and serotonin neurotransmission pathways were genotyped in all subjects. We identified three SNPs in genes that are significantly associated with fMRI activity. SNPs of the dopamine beta-hydroxylase (DBH) gene and of the dopamine receptor D4 (DRD4) were associated with activity in the temporal and frontal lobes, respectively. One SNP of serotonin-3A receptor (HTR3A) was associated with temporal lobe activity. The results of this study support the physiogenomic analysis of neuroimaging data to discover associations between genotype and disease-related phenotypes.

Attention-Induced Deactivations in Very Low Frequency EEG Oscillations: Differential Localisation According to ADHD Symptom Status

PubMed Central

Broyd, Samantha J.; Helps, Suzannah K.; Sonuga-Barke, Edmund J. S.

2011-01-01

Background The default-mode network (DMN) is characterised by coherent very low frequency (VLF) brain oscillations. The cognitive significance of this VLF profile remains unclear, partly because of the temporally constrained nature of the blood oxygen-level dependent (BOLD) signal. Previously we have identified a VLF EEG network of scalp locations that shares many features of the DMN. Here we explore the intracranial sources of VLF EEG and examine their overlap with the DMN in adults with high and low ADHD ratings. Methodology/Principal Findings DC-EEG was recorded using an equidistant 66 channel electrode montage in 25 adult participants with high- and 25 participants with low-ratings of ADHD symptoms during a rest condition and an attention demanding Eriksen task. VLF EEG power was calculated in the VLF band (0.02 to 0.2 Hz) for the rest and task condition and compared for high and low ADHD participants. sLORETA was used to identify brain sources associated with the attention-induced deactivation of VLF EEG power, and to examine these sources in relation to ADHD symptoms. There was significant deactivation of VLF EEG power between the rest and task condition for the whole sample. Using s-LORETA the sources of this deactivation were localised to medial prefrontal regions, posterior cingulate cortex/precuneus and temporal regions. However, deactivation sources were different for high and low ADHD groups: In the low ADHD group attention-induced VLF EEG deactivation was most significant in medial prefrontal regions while for the high ADHD group this deactivation was predominantly localised to the temporal lobes. Conclusions/Significance Attention-induced VLF EEG deactivations have intracranial sources that appear to overlap with those of the DMN. Furthermore, these seem to be related to ADHD symptom status, with high ADHD adults failing to significantly deactivate medial prefrontal regions while at the same time showing significant attenuation of VLF EEG power in temporal lobes. PMID:21408092

Perfusion network shift during seizures in medial temporal lobe epilepsy.

PubMed

Sequeira, Karen M; Tabesh, Ali; Sainju, Rup K; DeSantis, Stacia M; Naselaris, Thomas; Joseph, Jane E; Ahlman, Mark A; Spicer, Kenneth M; Glazier, Steve S; Edwards, Jonathan C; Bonilha, Leonardo

2013-01-01

Medial temporal lobe epilepsy (MTLE) is associated with limbic atrophy involving the hippocampus, peri-hippocampal and extra-temporal structures. While MTLE is related to static structural limbic compromise, it is unknown whether the limbic system undergoes dynamic regional perfusion network alterations during seizures. In this study, we aimed to investigate state specific (i.e. ictal versus interictal) perfusional limbic networks in patients with MTLE. We studied clinical information and single photon emission computed tomography (SPECT) images obtained with intravenous infusion of the radioactive tracer Technetium- Tc 99 m Hexamethylpropyleneamine Oxime (Tc-99 m HMPAO) during ictal and interictal state confirmed by video-electroencephalography (VEEG) in 20 patients with unilateral MTLE (12 left and 8 right MTLE). Pair-wise voxel-based analyses were used to define global changes in tracer between states. Regional tracer uptake was calculated and state specific adjacency matrices were constructed based on regional correlation of uptake across subjects. Graph theoretical measures were applied to investigate global and regional state specific network reconfigurations. A significant increase in tracer uptake was observed during the ictal state in the medial temporal region, cerebellum, thalamus, insula and putamen. From network analyses, we observed a relative decreased correlation between the epileptogenic temporal region and remaining cortex during the interictal state, followed by a surge of cross-correlated perfusion in epileptogenic temporal-limbic structures during a seizure, corresponding to local network integration. These results suggest that MTLE is associated with a state specific perfusion and possibly functional organization consisting of a surge of limbic cross-correlated tracer uptake during a seizure, with a relative disconnection of the epileptogenic temporal lobe in the interictal period. This pattern of state specific shift in metabolic networks in MTLE may improve the understanding of epileptogenesis and neuropsychological impairments associated with MTLE.

Meigo governs dendrite targeting specificity by modulating Ephrin level and N-glycosylation

PubMed Central

Sekine, Sayaka U; Haraguchi, Shuka; Chao, Kinhong; Kato, Tomoko; Luo, Liqun; Miura, Masayuki; Chihara, Takahiro

2016-01-01

Neural circuit assembly requires precise dendrite and axon targeting. We identified an evolutionarily conserved endoplasmic reticulum (ER) protein, Meigo, from a mosaic genetic screen in Drosophila melanogaster. Meigo was cell-autonomously required in olfactory receptor neurons and projection neurons to target their axons and dendrites to the lateral antennal lobe and to refine projection neuron dendrites into individual glomeruli. Loss of Meigo induced an unfolded protein response and reduced the amount of neuronal cell surface proteins, including Ephrin. Ephrin overexpression specifically suppressed the projection neuron dendrite refinement defect present in meigo mutant flies, and ephrin knockdown caused a similar projection neuron dendrite refinement defect. Meigo positively regulated the level of Ephrin N-glycosylation, which was required for its optimal function in vivo. Thus, Meigo, an ER-resident protein, governs neuronal targeting specificity by regulating ER folding capacity and protein N-glycosylation. Furthermore, Ephrin appears to be an important substrate that mediates Meigo’s function in refinement of glomerular targeting. PMID:23624514

Intrahepatic Size Regulation in a Surgical Model: Liver Resection-Induced Liver Regeneration Counteracts the Local Atrophy following Simultaneous Portal Vein Ligation.

PubMed

Wei, Weiwei; Zhang, Tianjiao; Fang, Haoshu; Dirsch, Olaf; Schenk, Andrea; Homeyer, André; Gremse, Felix; Zafarnia, Sara; Settmacher, Utz; Dahmen, Uta

2016-01-01

Liver size regulation is based on the balance between hepatic regeneration and atrophy. To achieve a better understanding of intrahepatic size regulation, we explored the size regulation of a portally deprived liver lobe on a liver subjected to concurrent portal vein ligation (PVL) and partial hepatectomy (PHx). Using a surgical rat model consisting of right PVL (rPVL) plus 70% PHx, we evaluated the size regulation of liver lobes 1, 2, 3, and 7 days after the operation in terms of liver weight and hepatocyte proliferation. Portal hyperperfusion was confirmed by measuring portal flow. The portal vascular tree was visualized by injection of a contrast agent followed by CT imaging of explanted livers. Control groups consisted of 70% PHx, rPVL, and sham operation. The size of the ligated right lobe increased to 1.4-fold on postoperative day 7 when subjected to rPVL + 70% PHx. The right lobe increased to 3-fold when subjected to 70% PHx alone and decreased to 0.3-fold when subjected to rPVL only. The small but significant increase in liver weight after the combined procedure was accompanied by a low proliferative response. In contrast, hepatocyte proliferation was undetectable in the right lobe undergoing atrophy after PVL only. The caudate lobe in the rPVL + 70% PHx group increased to 4.6-fold, which is significantly more than in the other groups. This increase in liver weight was paralleled by persisting portal hyperperfusion and a prolonged proliferative phase of 3 days. A discontinued portal blood supply does not always result in atrophy of the ligated lobe. The concurrent regenerative stimulus induced by 70% PHx seemed to counteract the local atrophy after a simultaneously performed rPVL, leading to a low but prolonged regenerative response of the portally deprived liver lobe. This observation supports the conclusion that portal flow is not necessary for liver regeneration. The persisting portal hyperperfusion may be crucial for the specific kinetics of prolonged liver regeneration after rPVL + 70% PHx in the portally supplied caudate lobe. Both observations deserve more attention regarding the underlying mechanism in further studies. © 2016 S. Karger AG, Basel.

Losing sight of the future: Impaired semantic prospection following medial temporal lobe lesions

PubMed Central

Race, Elizabeth; Keane, Margaret M.; Verfaellie, Mieke

2012-01-01

The ability to imagine the future (prospection) relies on many of the same brain regions that support memory for the past. To date, scientific research has primarily focused on the neural substrates of episodic forms of prospection (mental simulation of spatiotemporally specific future events) whereas little is known about the neural substrates of semantic prospection (mental simulation of future nonpersonal facts). Of particular interest is the role of the medial temporal lobes, and specifically the hippocampus. While the hippocampus has been proposed to play a key role in episodic prospection, recent evidence suggests that it may not play a similar role in semantic prospection. To examine this possibility, amnesic patients with medial temporal lobe (MTL) lesions were asked to imagine future issues occurring in the public domain. The results showed that patients could list general semantic facts about the future, but when probed to elaborate, patients produced impoverished descriptions that lacked semantic detail. This impairment occurred despite intact performance on standard neuropsychological tests of semantic processing, and did not simply reflect deficits in narrative construction. The performance of a patient with damage limited to the hippocampus was similar to that of the remaining MTL patients and amnesic patients’ impaired elaboration of the semantic future correlated with their impaired elaboration of the semantic past. Together, these results provide novel evidence from MTL amnesia that memory and prospection are linked in the semantic domain and reveal that the medial temporal lobes play a critical role in the construction of detailed, multi-element semantic simulations. PMID:23197413

On the definition and interpretation of voice selective activation in the temporal cortex

PubMed Central

Bethmann, Anja; Brechmann, André

2014-01-01

Regions along the superior temporal sulci and in the anterior temporal lobes have been found to be involved in voice processing. It has even been argued that parts of the temporal cortices serve as voice-selective areas. Yet, evidence for voice-selective activation in the strict sense is still missing. The current fMRI study aimed at assessing the degree of voice-specific processing in different parts of the superior and middle temporal cortices. To this end, voices of famous persons were contrasted with widely different categories, which were sounds of animals and musical instruments. The argumentation was that only brain regions with statistically proven absence of activation by the control stimuli may be considered as candidates for voice-selective areas. Neural activity was found to be stronger in response to human voices in all analyzed parts of the temporal lobes except for the middle and posterior STG. More importantly, the activation differences between voices and the other environmental sounds increased continuously from the mid-posterior STG to the anterior MTG. Here, only voices but not the control stimuli excited an increase of the BOLD response above a resting baseline level. The findings are discussed with reference to the function of the anterior temporal lobes in person recognition and the general question on how to define selectivity of brain regions for a specific class of stimuli or tasks. In addition, our results corroborate recent assumptions about the hierarchical organization of auditory processing building on a processing stream from the primary auditory cortices to anterior portions of the temporal lobes. PMID:25071527

Squamous cell carcinoma of the lung with highly proliferating fibromatosis-like stroma: a rare phenomenon.

PubMed

Tajima, Shogo; Takanashi, Yusuke; Koda, Kenji

2015-01-01

Few cases of carcinoma with exuberant stromal proliferation have been documented, apart from scirrhous carcinoma. To the best of our knowledge, previous cases of carcinoma exhibiting exuberant stromal proliferation have exclusively been reported in the thyroid gland, specifically as papillary carcinoma. The exuberant stromal proliferation has been recognized to be similar to either fibromatosis or nodular fasciitis. Herein, we report a case of a 74-year-old Japanese man whose tumor in the upper lobe of his right lung displayed highly proliferating stroma with dispersed, poorly differentiated squamous cell carcinoma nests. The stromal spindle cells (fibroblasts/myofibroblasts) had similar molecular profiles to those typically observed in fibromatosis rather than nodular fasciitis, resulting in the designation of "fibromatosis-like" stroma. The presence of carcinoma cells, along with stromal cells, expressing TGF-β in this case likely fostered continuous stromal proliferation, presumably in conjunction with the unique microenvironment in which the carcinoma cells were present.

Comparative study of bearing loads for different twin screw compressor rotor configurations

NASA Astrophysics Data System (ADS)

Buckney, D.; Anderson, C.

2017-08-01

Designing rotor geometry is a critical stage in the design of a twin screw compressor which has a significant impact on: capacity; leakage characteristics; thermodynamics; rotor stiffness; dynamics; and loading on the bearings. The focus of this paper is on bearing loads. In order to design screw compressors that can operate at higher pressures the bearings quickly become a limiting factor. With the need to house the bearings adjacent to one another on each of the parallel rotor shafts at a given centre distance there is an inherent limit to the bearing geometry envelope. In this investigation the ‘rotor configuration’ refers to the rotor lobe combination, length to diameter ratio (L/D), and wrap angle. The geometry of the transverse rotor profiles is kept constant, as far as possible, allowing conclusions to be drawn based on a manageable number of variables. A procedure to calculate bearing specific loads based on results from a thermodynamic chamber model is presented and results for a range of rotor configurations are discussed.

Preoperative automated fibre quantification predicts postoperative seizure outcome in temporal lobe epilepsy.

PubMed

Keller, Simon S; Glenn, G Russell; Weber, Bernd; Kreilkamp, Barbara A K; Jensen, Jens H; Helpern, Joseph A; Wagner, Jan; Barker, Gareth J; Richardson, Mark P; Bonilha, Leonardo

2017-01-01

Approximately one in every two patients with pharmacoresistant temporal lobe epilepsy will not be rendered completely seizure-free after temporal lobe surgery. The reasons for this are unknown and are likely to be multifactorial. Quantitative volumetric magnetic resonance imaging techniques have provided limited insight into the causes of persistent postoperative seizures in patients with temporal lobe epilepsy. The relationship between postoperative outcome and preoperative pathology of white matter tracts, which constitute crucial components of epileptogenic networks, is unknown. We investigated regional tissue characteristics of preoperative temporal lobe white matter tracts known to be important in the generation and propagation of temporal lobe seizures in temporal lobe epilepsy, using diffusion tensor imaging and automated fibre quantification. We studied 43 patients with mesial temporal lobe epilepsy associated with hippocampal sclerosis and 44 healthy controls. Patients underwent preoperative imaging, amygdalohippocampectomy and postoperative assessment using the International League Against Epilepsy seizure outcome scale. From preoperative imaging, the fimbria-fornix, parahippocampal white matter bundle and uncinate fasciculus were reconstructed, and scalar diffusion metrics were calculated along the length of each tract. Altogether, 51.2% of patients were rendered completely seizure-free and 48.8% continued to experience postoperative seizure symptoms. Relative to controls, both patient groups exhibited strong and significant diffusion abnormalities along the length of the uncinate bilaterally, the ipsilateral parahippocampal white matter bundle, and the ipsilateral fimbria-fornix in regions located within the medial temporal lobe. However, only patients with persistent postoperative seizures showed evidence of significant pathology of tract sections located in the ipsilateral dorsal fornix and in the contralateral parahippocampal white matter bundle. Using receiver operating characteristic curves, diffusion characteristics of these regions could classify individual patients according to outcome with 84% sensitivity and 89% specificity. Pathological changes in the dorsal fornix were beyond the margins of resection, and contralateral parahippocampal changes may suggest a bitemporal disorder in some patients. Furthermore, diffusion characteristics of the ipsilateral uncinate could classify patients from controls with a sensitivity of 98%; importantly, by co-registering the preoperative fibre maps to postoperative surgical lacuna maps, we observed that the extent of uncinate resection was significantly greater in patients who were rendered seizure-free, suggesting that a smaller resection of the uncinate may represent insufficient disconnection of an anterior temporal epileptogenic network. These results may have the potential to be developed into imaging prognostic markers of postoperative outcome and provide new insights for why some patients with temporal lobe epilepsy continue to experience postoperative seizures. © The Author (2016). Published by Oxford University Press on behalf of the Guarantors of Brain.

Preoperative automated fibre quantification predicts postoperative seizure outcome in temporal lobe epilepsy

PubMed Central

Keller, Simon S; Glenn, G Russell; Weber, Bernd; Kreilkamp, Barbara A K; Jensen, Jens H; Helpern, Joseph A; Wagner, Jan; Barker, Gareth J; Richardson, Mark P; Bonilha, Leonardo

2017-01-01

Abstract Approximately one in every two patients with pharmacoresistant temporal lobe epilepsy will not be rendered completely seizure-free after temporal lobe surgery. The reasons for this are unknown and are likely to be multifactorial. Quantitative volumetric magnetic resonance imaging techniques have provided limited insight into the causes of persistent postoperative seizures in patients with temporal lobe epilepsy. The relationship between postoperative outcome and preoperative pathology of white matter tracts, which constitute crucial components of epileptogenic networks, is unknown. We investigated regional tissue characteristics of preoperative temporal lobe white matter tracts known to be important in the generation and propagation of temporal lobe seizures in temporal lobe epilepsy, using diffusion tensor imaging and automated fibre quantification. We studied 43 patients with mesial temporal lobe epilepsy associated with hippocampal sclerosis and 44 healthy controls. Patients underwent preoperative imaging, amygdalohippocampectomy and postoperative assessment using the International League Against Epilepsy seizure outcome scale. From preoperative imaging, the fimbria-fornix, parahippocampal white matter bundle and uncinate fasciculus were reconstructed, and scalar diffusion metrics were calculated along the length of each tract. Altogether, 51.2% of patients were rendered completely seizure-free and 48.8% continued to experience postoperative seizure symptoms. Relative to controls, both patient groups exhibited strong and significant diffusion abnormalities along the length of the uncinate bilaterally, the ipsilateral parahippocampal white matter bundle, and the ipsilateral fimbria-fornix in regions located within the medial temporal lobe. However, only patients with persistent postoperative seizures showed evidence of significant pathology of tract sections located in the ipsilateral dorsal fornix and in the contralateral parahippocampal white matter bundle. Using receiver operating characteristic curves, diffusion characteristics of these regions could classify individual patients according to outcome with 84% sensitivity and 89% specificity. Pathological changes in the dorsal fornix were beyond the margins of resection, and contralateral parahippocampal changes may suggest a bitemporal disorder in some patients. Furthermore, diffusion characteristics of the ipsilateral uncinate could classify patients from controls with a sensitivity of 98%; importantly, by co-registering the preoperative fibre maps to postoperative surgical lacuna maps, we observed that the extent of uncinate resection was significantly greater in patients who were rendered seizure-free, suggesting that a smaller resection of the uncinate may represent insufficient disconnection of an anterior temporal epileptogenic network. These results may have the potential to be developed into imaging prognostic markers of postoperative outcome and provide new insights for why some patients with temporal lobe epilepsy continue to experience postoperative seizures. PMID:28031219

Bilingualism Alters Children's Frontal Lobe Functioning for Attentional Control

PubMed Central

Arredondo, Maria M.; Hu, Xiao-Su; Satterfield, Teresa; Kovelman, Ioulia

2017-01-01

Bilingualism is a typical linguistic experience, yet relatively little is known about its impact on children's cognitive and brain development. Theories of bilingualism suggest early dual-language acquisition can improve children's cognitive abilities, specifically those relying on frontal lobe functioning. While behavioral findings present much conflicting evidence, little is known about its effects on children's frontal lobe development. Using functional Near-Infrared Spectroscopy (fNIRS), the findings suggest that Spanish-English bilingual children (n=13, ages 7-13) had greater activation in left prefrontal cortex during a non-verbal attentional control task relative to age-matched English monolinguals. In contrast, monolinguals (n=14) showed greater right prefrontal activation than bilinguals. The present findings suggest early bilingualism yields significant changes to the functional organization of children's prefrontal cortex for attentional control and carry implications for understanding how early life experiences impact cognition and brain development. PMID:26743118

Adiabatic Mass Loss Model in Binary Stars

NASA Astrophysics Data System (ADS)

Ge, H. W.

2012-07-01

Rapid mass transfer process in the interacting binary systems is very complicated. It relates to two basic problems in the binary star evolution, i.e., the dynamically unstable Roche-lobe overflow and the common envelope evolution. Both of the problems are very important and difficult to be modeled. In this PhD thesis, we focus on the rapid mass loss process of the donor in interacting binary systems. The application to the criterion of dynamically unstable mass transfer and the common envelope evolution are also included. Our results based on the adiabatic mass loss model could be used to improve the binary evolution theory, the binary population synthetic method, and other related aspects. We build up the adiabatic mass loss model. In this model, two approximations are included. The first one is that the energy generation and heat flow through the stellar interior can be neglected, hence the restructuring is adiabatic. The second one is that he stellar interior remains in hydrostatic equilibrium. We model this response by constructing model sequences, beginning with a donor star filling its Roche lobe at an arbitrary point in its evolution, holding its specific entropy and composition profiles fixed. These approximations are validated by the comparison with the time-dependent binary mass transfer calculations and the polytropic model for low mass zero-age main-sequence stars. In the dynamical time scale mass transfer, the adiabatic response of the donor star drives it to expand beyond its Roche lobe, leading to runaway mass transfer and the formation of a common envelope with its companion star. For donor stars with surface convection zones of any significant depth, this runaway condition is encountered early in mass transfer, if at all; but for main sequence stars with radiative envelopes, it may be encountered after a prolonged phase of thermal time scale mass transfer, so-called delayed dynamical instability. We identify the critical binary mass ratio for the onset of dynamical time scale mass transfer; if the ratio of donor to accretor masses exceeds this critical value, the dynamical time scale mass transfer ensues. The grid of criterion for all stars can be used to be the basic input as the binary population synthetic method, which will be improved absolutely. In common envelope evolution, the dissipation of orbital energy of the binary provides the energy to eject the common envelope; the energy budget for this process essentially consists of the initial orbital energy of the binary and the initial binding energies of the binary components. We emphasize that, because stellar core and envelope contribute mutually to each other's gravitational potential energy, proper evaluation of the total energy of a star requires integration over the entire stellar interior, not the ejected envelope alone as commonly assumed. We show that the change in total energy of the donor star, as a function of its remaining mass along an adiabatic mass-loss sequence, can be calculated. This change in total energy of the donor star, combined with the requirement that both remnant donor and its companion star fit within their respective Roche lobes, then circumscribes energetically possible survivors of common envelope evolution. It is the first time that we can calculate the accurate total energy of the donor star in common envelope evolution, while the results with the old method are inconsistent with observations.

Ngc7538 Irs1 - A Highly Collimated Ionized Wind Source Powered By Accretion

NASA Astrophysics Data System (ADS)

Sandell, Goran H. L.; Wright, M.; Goss, W.; Corder, S.

2009-01-01

Recent images show that NGC7538 IRS1 is not a conventional Ultracompact or Hypercompact HII region, but is completely wind-excited (other broad recombination line hypercompact HII regions may be similar to IRS1). NGC 7538 IRS1 is a well studied young high-mass star (L 2 10^5 L_Sun).VLA images at 6 and 2 cm (Cambell 1984; ApJ, 282, L27) showed a compact bipolar core (lobe separation 0.2") with more extended faint lobes. Recombination line observations (Gaume et al. 1995, ApJ, 438, 776) show extremely wide line profiles indicating substantial mass motion of the ionized gas. We re-analyzed high angular resolution VLA archive data from 6 cm to 7 mm, and measured the flux from the compact core and the extended (1.5 - 2") bipolar lobes. We find that the compact core has a spectral index, alpha 0.6, which could be explained by an optically thick hypercompact core with a density gradient. However, the size of the core shrinks with increasing frequency; from 0.24" at 6 cm to 0.1" at 7 mm, consistent with that expected for a collimated jet (Reynolds 1986, ApJ, 304, 713). If we do a crude size correction so that we compare emission from the optically thick inner part of the jet for a set of 2 cm and 7 mm observations we get alpha 1.6, i.e. close to the optically thick value. BIMA and CARMA continuum observations at 3 mm show some dust excess, while. HCO+ J=1-0 observations combined with FCRAO single dish data show a clear inverse P Cygni profile towards IRS1. These observations confirm that IRS1 is heavily accreting with an accretion rate 2 10^-4 M_Sun/year, sufficient to quench the formation of an HII region.

Lactoferrin-derived Peptides Active towards Influenza: Identification of Three Potent Tetrapeptide Inhibitors.

PubMed

Scala, Maria Carmina; Sala, Marina; Pietrantoni, Agostina; Spensiero, Antonia; Di Micco, Simone; Agamennone, Mariangela; Bertamino, Alessia; Novellino, Ettore; Bifulco, Giuseppe; Gomez-Monterrey, Isabel M; Superti, Fabiana; Campiglia, Pietro

2017-09-06

Bovine lactoferrin is a biglobular multifunctional iron binding glycoprotein that plays an important role in innate immunity against infections. We have previously demonstrated that selected peptides from bovine lactoferrin C-lobe are able to prevent both Influenza virus hemagglutination and cell infection. To deeper investigate the ability of lactoferrin derived peptides to inhibit Influenza virus infection, in this study we identified new bovine lactoferrin C-lobe derived sequences and corresponding synthetic peptides were synthesized and assayed to check their ability to prevent viral hemagglutination and infection. We identified three tetrapeptides endowed with broad anti-Influenza activity and able to inhibit viral infection in a concentration range femto- to picomolar. Our data indicate that these peptides may constitute a non-toxic tool for potential applications as anti-Influenza therapeutics.

Processing Stages Underlying Word Recognition in the Anteroventral Temporal Lobe

PubMed Central

Halgren, Eric; Wang, Chunmao; Schomer, Donald L.; Knake, Susanne; Marinkovic, Ksenija; Wu, Julian; Ulbert, Istvan

2006-01-01

The anteroventral temporal lobe integrates visual, lexical, semantic and mnestic aspects of word-processing, through its reciprocal connections with the ventral visual stream, language areas, and the hippocampal formation. We used linear microelectrode arrays to probe population synaptic currents and neuronal firing in different cortical layers of the anteroventral temporal lobe, during semantic judgments with implicit priming, and overt word recognition. Since different extrinsic and associative inputs preferentially target different cortical layers, this method can help reveal the sequence and nature of local processing stages at a higher resolution than was previously possible. The initial response in inferotemporal and perirhinal cortices is a brief current sink beginning at ~120ms, and peaking at ~170ms. Localization of this initial sink to middle layers suggests that it represents feedforward input from lower visual areas, and simultaneously increased firing implies that it represents excitatory synaptic currents. Until ~800ms, the main focus of transmembrane current sinks alternates between middle and superficial layers, with the superficial focus becoming increasingly dominant after ~550ms. Since superficial layers are the target of local and feedback associative inputs, this suggests an alternation in predominant synaptic input between feedforward and feedback modes. Word repetition does not affect the initial perirhinal and inferotemporal middle layer sink, but does decrease later activity. Entorhinal activity begins later (~200ms), with greater apparent excitatory postsynaptic currents and multiunit activity in neocortically-projecting than hippocampal-projecting layers. In contrast to perirhinal and entorhinal responses, entorhinal responses are larger to repeated words during memory retrieval. These results identify a sequence of physiological activation, beginning with a sharp activation from lower level visual areas carrying specific information to middle layers. This is followed by feedback and associative interactions involving upper cortical layers, which are abbreviated to repeated words. Following bottom-up and associative stages, top-down recollective processes may be driven by entorhinal cortex. Word processing involves a systematic sequence of fast feedforward information transfer from visual areas to anteroventral temporal cortex, followed by prolonged interactions of this feedforward information with local associations, and feedback mnestic information from the medial temporal lobe. PMID:16488158

Expression and function of the metabotropic purinergic P2Y receptor family in experimental seizure models and patients with drug-refractory epilepsy.

PubMed

Alves, Mariana; Gomez-Villafuertes, Rosa; Delanty, Norman; Farrell, Michael A; O'Brien, Donncha F; Miras-Portugal, Maria Teresa; Hernandez, Miguel Diaz; Henshall, David C; Engel, Tobias

2017-09-01

ATP is released into the extracellular space during pathologic processes including increased neuronal firing. Once released, ATP acts on P2 receptors including ionotropic P2X and metabotropic P2Y receptors, resulting in changes to glial function and neuronal network excitability. Evidence suggests an involvement of P2Y receptors in the pathogenesis of epilepsy, but there has been no systematic effort to characterize the expression and function of the P2Y receptor family during seizures and in experimental and human epilepsy. Status epilepticus was induced using either intra-amygdala kainic acid or pilocarpine to characterize the acute- and long-term changes in hippocampal P2Y expression. P2Y expression was also investigated in brain tissue from patients with temporal lobe epilepsy. Finally, we analyzed the effects of two specific P2Y agonists, ADP and UTP, on seizure severity and seizure-induced cell death. Both intra-amygdala kainic acid and pilocarpine-induced status epilepticus increased the transcription of the uracil-sensitive P2Y receptors P2ry 2 , P2ry 4 , and P2ry 6 and decreased the transcription of the adenine-sensitive P2Y receptors P2ry 1 , P2ry 12 , P2ry 13 . Protein levels of P2Y 1 , P2Y 2 , P2Y 4 , and P2Y 6 were increased after status epilepticus, whereas P2Y 12 expression was decreased. In the chronic phase, P2ry 1 , P2ry 2 , and P2ry 6 transcription and P2Y 1 , P2Y 2 , and P2Y 12 protein levels were increased with no changes for the other P2Y receptors. In hippocampal samples from patients with temporal lobe epilepsy, P2Y 1 and P2Y 2 protein expression was increased, whereas P2Y 13 levels were lower. Demonstrating a functional contribution of P2Y receptors to seizures, central injection of ADP exacerbated seizure severity, whereas treatment with UTP decreased seizure severity during status epilepticus in mice. The present study is the first to establish the specific hippocampal expression profile and function of the P2Y receptor family after experimental status epilepticus and in human temporal lobe epilepsy and offers potential new targets for seizure control and disease modification. Wiley Periodicals, Inc. © 2017 International League Against Epilepsy.

High resolution anatomical and quantitative MRI of the entire human occipital lobe ex vivo at 9.4T.

PubMed

Sengupta, S; Fritz, F J; Harms, R L; Hildebrand, S; Tse, D H Y; Poser, B A; Goebel, R; Roebroeck, A

2018-03-01

Several magnetic resonance imaging (MRI) contrasts are sensitive to myelin content in gray matter in vivo which has ignited ambitions of MRI-based in vivo cortical histology. Ultra-high field (UHF) MRI, at fields of 7T and beyond, is crucial to provide the resolution and contrast needed to sample contrasts over the depth of the cortex and get closer to layer resolved imaging. Ex vivo MRI of human post mortem samples is an important stepping stone to investigate MRI contrast in the cortex, validate it against histology techniques applied in situ to the same tissue, and investigate the resolutions needed to translate ex vivo findings to in vivo UHF MRI. Here, we investigate key technology to extend such UHF studies to large human brain samples while maintaining high resolution, which allows investigation of the layered architecture of several cortical areas over their entire 3D extent and their complete borders where architecture changes. A 16 channel cylindrical phased array radiofrequency (RF) receive coil was constructed to image a large post mortem occipital lobe sample (~80×80×80mm 3 ) in a wide-bore 9.4T human scanner with the aim of achieving high-resolution anatomical and quantitative MR images. Compared with a human head coil at 9.4T, the maximum Signal-to-Noise ratio (SNR) was increased by a factor of about five in the peripheral cortex. Although the transmit profile with a circularly polarized transmit mode at 9.4T is relatively inhomogeneous over the large sample, this challenge was successfully resolved with parallel transmit using the kT-points method. Using this setup, we achieved 60μm anatomical images for the entire occipital lobe showing increased spatial definition of cortical details compared to lower resolutions. In addition, we were able to achieve sufficient control over SNR, B 0 and B 1 homogeneity and multi-contrast sampling to perform quantitative T 2 * mapping over the same volume at 200μm. Markov Chain Monte Carlo sampling provided maximum posterior estimates of quantitative T 2 * and their uncertainty, allowing delineation of the stria of Gennari over the entire length and width of the calcarine sulcus. We discuss how custom RF receive coil arrays built to specific large post mortem sample sizes can provide a platform for UHF cortical layer-specific quantitative MRI over large fields of view. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Two-photon calcium imaging from head-fixed Drosophila during optomotor walking behavior.

PubMed

Seelig, Johannes D; Chiappe, M Eugenia; Lott, Gus K; Dutta, Anirban; Osborne, Jason E; Reiser, Michael B; Jayaraman, Vivek

2010-07-01

Drosophila melanogaster is a model organism rich in genetic tools to manipulate and identify neural circuits involved in specific behaviors. Here we present a technique for two-photon calcium imaging in the central brain of head-fixed Drosophila walking on an air-supported ball. The ball's motion is tracked at high resolution and can be treated as a proxy for the fly's own movements. We used the genetically encoded calcium sensor, GCaMP3.0, to record from important elements of the motion-processing pathway, the horizontal-system lobula plate tangential cells (LPTCs) in the fly optic lobe. We presented motion stimuli to the tethered fly and found that calcium transients in horizontal-system neurons correlated with robust optomotor behavior during walking. Our technique allows both behavior and physiology in identified neurons to be monitored in a genetic model organism with an extensive repertoire of walking behaviors.

Clinical utility of flumazenil-PET versus [18F]fluorodeoxyglucose-PET and MRI in refractory partial epilepsy. A prospective study in 100 patients.

PubMed

Ryvlin, P; Bouvard, S; Le Bars, D; De Lamérie, G; Grégoire, M C; Kahane, P; Froment, J C; Mauguière, F

1998-11-01

We assessed the clinical utility of [11C]flumazenil-PET (FMZ-PET) prospectively in 100 epileptic patients undergoing a pre-surgical evaluation, and defined the specific contribution of this neuro-imaging technique with respect to those of MRI and [18F]fluorodeoxyglucose-PET (FDG-PET). All patients benefited from a long term video-EEG monitoring, whereas an intracranial EEG investigation was performed in 40 cases. Most of our patients (73%) demonstrated a FMZ-PET abnormality; this hit rate was significantly higher in temporal lobe epilepsy (94%) than in other types of epilepsy (50%) (P < 0.001). Most FMZ-PET findings coexisted with a MRI abnormality (81%), including hippocampal atrophy (35%) and focal hypometabolism on FDG-PET (89%). The area of decreased FMZ binding was often smaller than that of glucose hypometabolism (48%) or larger than that of the MRI abnormality (28%). FMZ-PET did not prove superior to FDG-PET in assessing the extent of the ictal onset zone, as defined by intracranial EEG recordings. However, it provided useful data which were complementary to those of MRI and FDG-PET in three situations: (i) in temporal lobe epilepsy associated with MRI signs of hippocampal sclerosis, FMZ-PET abnormalities delineated the site of seizure onset precisely, whenever they were coextensive with FDG-PET abnormalities; (ii) in bi-temporal epilepsy, FMZ-PET helped to confirm the bilateral origin of seizures by showing a specific pattern of decreased FMZ binding in both temporal lobes in 33% of cases; (iii) in patients with a unilateral cryptogenic frontal lobe epilepsy, FMZ-PET provided further evidence of the side and site of seizure onset in 55% of cases. Thus, FMZ-PET deserves to be included in the pre-surgical evaluation of these specific categories of epileptic patients, representing approximately half of the population considered for epilepsy surgery.

Emotion recognition and social cognition in temporal lobe epilepsy and the effect of epilepsy surgery.

PubMed

Amlerova, Jana; Cavanna, Andrea E; Bradac, Ondrej; Javurkova, Alena; Raudenska, Jaroslava; Marusic, Petr

2014-07-01

The abilities to identify facial expression from another person's face and to attribute mental states to others refer to preserved function of the temporal lobes. In the present study, we set out to evaluate emotion recognition and social cognition in presurgical and postsurgical patients with unilateral refractory temporal lobe epilepsy (TLE). The aim of our study was to investigate the effects of TLE surgery and to identify the main risk factors for impairment in these functions. We recruited 30 patients with TLE for longitudinal data analysis (14 with right-sided and 16 with left-sided TLE) and 74 patients for cross-sectional data analysis (37 with right-sided and 37 with left-sided TLE) plus 20 healthy controls. Besides standard neuropsychological assessment, we administered an analog of the Ekman and Friesen test and the Faux Pas Test to assess emotion recognition and social cognition, respectively. Both emotion recognition and social cognition were impaired in the group of patients with TLE, irrespective of the focus side, compared with healthy controls. The performance in both tests was strongly dependent on the intelligence level. Beyond intelligence level, earlier age at epilepsy onset, longer disease duration, and history of early childhood brain injury predicted social cognition problems in patients with TLE. Epilepsy surgery within the temporal lobe seems to have neutral effect on patients' performances in both domains. However, there are a few individual patients who appear to be at risk of postoperative decline, even when seizure freedom is achieved following epilepsy surgery. Copyright © 2014 Elsevier Inc. All rights reserved.

Psychosocial and Cognitive Functioning of Children with Specific Profiles of Maltreatment

ERIC Educational Resources Information Center

Pears, Katherine C.; Kim, Hyoun K.; Fisher, Philip A.

2008-01-01

Objective: Up to 90% of child welfare system cases involve multiple types of maltreatment; however, studies have rarely incorporated multiple dimensions of maltreatment. The present study employed a latent profile analysis to identify naturally occurring subgroups of children who had experienced maltreatment. Methods: Reports of maltreatment…

Generalized Roche potential for misaligned binary systems - Properties of the critical lobe

NASA Technical Reports Server (NTRS)

Avni, Y.; Schiller, N.

1982-01-01

The paper considers the Roche potential for binary systems where the stellar rotation axis is not aligned with the orbital revolution axis. It is shown that, as the degree of misalignment varies, internal Lagrangian points and external Lagrangian points may switch their roles. A systematic method to identify the internal Lagrangian point and to calculate the volume of the critical lobe is developed, and numerical results for a wide range of parameters of binary systems with circular orbits are presented. For binary systems with large enough misalignment, discrete changes occur in the topological structure of the equipotential surfaces as the orbital phase varies. The volume of the critical lobe has minima, as a function of orbital phase, at the two instances when the secondary crosses the equatorial plane of the primary. In semidetached systems, mass transfer may be confined to the vicinity of these two instances.

Decreased subcortical cholinergic arousal in focal seizures

PubMed Central

Motelow, Joshua E.; Li, Wei; Zhan, Qiong; Mishra, Asht M.; Sachdev, Robert N. S.; Liu, Geoffrey; Gummadavelli, Abhijeet; Zayyad, Zaina; Lee, Hyun Seung; Chu, Victoria; Andrews, John P.; Englot, Dario J.; Herman, Peter; Sanganahalli, Basavaraju G.; Hyder, Fahmeed; Blumenfeld, Hal

2015-01-01

SUMMARY Impaired consciousness in temporal lobe seizures has a major negative impact on quality of life. The prevailing view holds that this disorder impairs consciousness by seizure spread to the bilateral temporal lobes. We propose instead that seizures invade subcortical regions and depress arousal, causing impairment through decreases rather than through increases in activity. Using functional magnetic resonance imaging in a rodent model, we found increased activity in regions known to depress cortical function including lateral septum and anterior hypothalamus. Importantly, we found suppression of intralaminar thalamic and brainstem arousal systems and suppression of the cortex. At a cellular level, we found reduced firing of identified cholinergic neurons in the brainstem pedunculopontine tegmental nucleus and basal forebrain. Finally, we used enzyme-based amperometry to demonstrate reduced cholinergic neurotransmission in both cortex and thalamus. Decreased subcortical arousal is a novel mechanism for loss of consciousness in focal temporal lobe seizures. PMID:25654258

Design of multi-modal obstruction to control tonal fan noise using modulation principles

NASA Astrophysics Data System (ADS)

Gérard, Anthony; Moreau, Stéphane; Berry, Alain; Masson, Patrice

2015-11-01

The approach presented in this paper uses a combination of obstructions in the upstream flow of subsonic axial fans with B blades to destructively interfere with the primary tonal noise at the blade passage frequency. The first step of the proposed experimental method consists in identifying the independent radiation of B - 1 and B lobed obstructions at the control microphones. During this identification step, rotating obstructions allow for the frequencies of primary and secondary tonal noise to be slightly shifted in the spectrum due to modulation principles. The magnitude of the secondary tonal noise generated by each obstruction can be adjusted by varying the size of the lobes of the obstruction, and the phase of the secondary tonal noise is related to the angular position of the obstruction. The control obstructions are then optimized by combining the B - 1 and B lobed obstructions to significantly reduce the acoustic power at blade passage frequency.

Applications of nutrient profiling: potential role in diet-related chronic disease prevention and the feasibility of a core nutrient-profiling system.

PubMed

Sacks, G; Rayner, M; Stockley, L; Scarborough, P; Snowdon, W; Swinburn, B

2011-03-01

A number of different nutrient-profiling models have been proposed and several applications of nutrient profiling have been identified. This paper outlines the potential role of nutrient-profiling applications in the prevention of diet-related chronic disease (DRCD), and considers the feasibility of a core nutrient-profiling system, which could be modified for purpose, to underpin the multiple potential applications in a particular country. The 'Four 'P's of Marketing' (Product, Promotion, Place and Price) are used as a framework for identifying and for classifying potential applications of nutrient profiling. A logic pathway is then presented that can be used to gauge the potential impact of nutrient-profiling interventions on changes in behaviour, changes in diet and, ultimately, changes in DRCD outcomes. The feasibility of a core nutrient-profiling system is assessed by examining the implications of different model design decisions and their suitability to different purposes. There is substantial scope to use nutrient profiling as part of the policies for the prevention of DRCD. A core nutrient-profiling system underpinning the various applications is likely to reduce discrepancies and minimise the confusion for regulators, manufacturers and consumers. It seems feasible that common elements, such as a standard scoring method, a core set of nutrients and food components, and defined food categories, could be incorporated as part of a core system, with additional application-specific criteria applying. However, in developing and in implementing such a system, several country-specific contextual and technical factors would need to be balanced.

Biologic lung volume reduction in advanced upper lobe emphysema: phase 2 results.

PubMed

Criner, Gerard J; Pinto-Plata, Victor; Strange, Charlie; Dransfield, Mark; Gotfried, Mark; Leeds, William; McLennan, Geoffrey; Refaely, Yael; Tewari, Sanjiv; Krasna, Mark; Celli, Bartolome

2009-05-01

Biologic lung volume reduction (BioLVR) is a new endobronchial treatment for advanced emphysema that reduces lung volume through tissue remodeling. Assess the safety and therapeutic dose of BioLVR hydrogel in upper lobe predominant emphysema. Open-labeled, multicenter phase 2 dose-ranging studies were performed with BioLVR hydrogel administered to eight subsegmental sites (four in each upper lobe) involving: (1) low-dose treatment (n = 28) with 10 ml per site (LD); and (2) high-dose treatment (n = 22) with 20 ml per site (HD). Safety was assessed by the incidence of serious medical complications. Efficacy was assessed by change from baseline in pulmonary function tests, dyspnea score, 6-minute walk distance, and health-related quality of life. After treatment there were no deaths and four serious treatment-related complications. A reduction in residual volume to TLC ratio at 12 weeks (primary efficacy outcome) was achieved with both LD (-6.4 +/- 9.3%; P = 0.002) and HD (-5.5 +/- 9.4%; P = 0.028) treatments. Improvements in pulmonary function in HD (6 mo: DeltaFEV(1) = +15.6%; P = 0.002; DeltaFVC = +9.1%; P = 0.034) were greater than in LD patients (6 mo: DeltaFEV(1) = +6.7%; P = 0.021; DeltaFVC = +5.1%; P = 0.139). LD- and HD-treated groups both demonstrated improved symptom scores and health-related quality of life. BioLVR improves physiology and functional outcomes up to 6 months with an acceptable safety profile in upper lobe predominant emphysema. Overall improvement was greater and responses more durable with 20 ml per site than 10 ml per site dosing. Clinical trial registered with www.clinicaltrials.gov (NCT 00435253 and NCT 00515164).

The Ionian and Alfeo-Etna fault zones: New segments of an evolving plate boundary in the central Mediterranean Sea?

NASA Astrophysics Data System (ADS)

Polonia, A.; Torelli, L.; Artoni, A.; Carlini, M.; Faccenna, C.; Ferranti, L.; Gasperini, L.; Govers, R.; Klaeschen, D.; Monaco, C.; Neri, G.; Nijholt, N.; Orecchio, B.; Wortel, R.

2016-04-01

The Calabrian Arc is a narrow subduction-rollback system resulting from Africa/Eurasia plate convergence. While crustal shortening is taken up in the accretionary wedge, transtensive deformation accounts for margin segmentation along transverse lithospheric faults. One of these structures is the NNW-SSE transtensive fault system connecting the Alfeo seamount and the Etna volcano (Alfeo-Etna Fault, AEF). A second, NW-SE crustal discontinuity, the Ionian Fault (IF), separates two lobes of the CA subduction complex (Western and Eastern Lobes) and impinges on the Sicilian coasts south of the Messina Straits. Analysis of multichannel seismic reflection profiles shows that: 1) the IF and the AEF are transfer crustal tectonic features bounding a complex deformation zone, which produces the downthrown of the Western lobe along a set of transtensive fault strands; 2) during Pleistocene times, transtensive faulting reactivated structural boundaries inherited from the Mesozoic Tethyan domain which acted as thrust faults during the Messinian and Pliocene; and 3) the IF and the AEF, and locally the Malta escarpment, accommodate a recent tectonic event coeval and possibly linked to the Mt. Etna formation. Regional geodynamic models show that, whereas AEF and IF are neighboring fault systems, their individual roles are different. Faulting primarily resulting from the ESE retreat of the Ionian slab is expressed in the northwestern part of the IF. The AEF, on the other hand, is part of the overall dextral shear deformation, resulting from differences in Africa-Eurasia motion between the western and eastern sectors of the Tyrrhenian margin of northern Sicily, and accommodating diverging motions in the adjacent compartments, which results in rifting processes within the Western Lobe of the Calabrian Arc accretionary wedge. As such, it is primarily associated with Africa-Eurasia relative motion.

Clinical characteristics, surgical and neuropsychological outcomes in drug resistant tumoral temporal lobe epilepsy.

PubMed

Ravat, Sangeeta; Iyer, Vivek; Muzumdar, Dattatraya; Shah, Urvashi; Pradhan, Pranjali; Jain, Neeraj; Godge, Yogesh

2016-12-01

Glioneuronal tumors are found in nearly one third patients who undergo surgery for pharmacoresistant epilepsy with temporal lobe being the most common location. Few studies, however have concentrated on the neurological and neuropsychological outcomes after surgery, hitherto none from India. We studied 34 patients with temporal lobe tumors and drug resistant epilepsy. These patients underwent anterior temporal lobectomy or lesionectomy based on the involvement of the hippocampus and mesial temporal structures. The clinical history, EEG, neuropsychology profile and MRI were compared. Seizure outcome was categorized using Engel's classification. At a mean follow up of 62 months, 85.29% of the patients were seizure free (Engel's Class I). All 8 patients with intraoperative electrocorticography (ECoG) guided resection were seizure free. Presence of a residual lesion was significantly associated with persistence of seizures post surgery (p = 0.002). Group analysis revealed no significant shifts in IQ and memory scores postoperatively. There was a significant improvement in the quality of life scores (total and across all subdomains) in all patients (p < 0.001). Postoperative EEG abnormalities predicted unfavorable ​seizure outcome. Surgery for temporal lobe tumors and refractory epilepsy offers complete seizure freedom in majority. Complete surgical excision of the epileptogenic zone is of paramount importance in achieving seizure freedom. Intraoperative electrocorticography (EcoG) is a useful adjunct to ensure complete removal of epileptogenic zone, thus achieving optimal seizure freedom. There is a significant improvement in the quality of life scores (p < 0.001) with no negative impact of surgery on memory and intelligence. Even the patients who are not seizure free can achieve worthwhile improvement post surgery. Copyright © 2015 IJS Publishing Group Ltd. Published by Elsevier Ltd. All rights reserved.

The Energetic Neutral Atoms of the "Croissant" Heliosphere with Jets

NASA Astrophysics Data System (ADS)

Kornbleuth, M. Z.; Opher, M.; Michael, A.

2017-12-01

Opher et al. (2015) suggests the heliosphere may have two jets in the tail-ward direction driven to the north and south. This new model, the "Croissant Heliosphere", is in contrast to the classically accepted view of a comet-like tail. We investigate the effect of the heliosphere with jets model on energetic neutral atom (ENA) maps. Regardless of the existence of a split tail, other models show heliosheath plasma confined by the toroidal magnetic field in a "slinky" structure, similar to astrophysical jets bent by the interstellar medium. Therefore, the confinement of the plasma should appear in the ENA maps. ENA maps from the Interstellar Boundary Explorer (IBEX) have recently shown two high latitude lobes with excess ENA flux at higher energies in the tail of the heliosphere. These lobes could be a signature of the two jet structure of the heliosphere, while some have argued they are cause by the fast/slow solar wind profile. Here we present the ENA maps of the "Croissant Heliosphere" using initially a uniform solar wind. We incorporate pick-up ions (PUIs) into our model based on the kinetic modeling of Malama et al. (2006). We include the extinction of PUIs in the heliosheath and describe a locally created PUI population resulting from this extinction process. Additionally, we include the angular dependence of the PUIs based on the work of Vasyliunas & Siscoe (1976). With our model, we find that, in the presence of a uniform solar wind, the "heliosphere with jets" model is able to qualitatively reproduce the lobe structure of the tail seen in IBEX measurements. Turbulence also manifests itself within the lobes of the simulated ENA maps on the order of years. Finally we will present ENA maps using a time-dependent model of the heliosphere with the inclusion of solar cycle.

The thermal structure of Titan’s upper atmosphere, I: Temperature profiles from Cassini INMS observations

NASA Astrophysics Data System (ADS)

Snowden, D.; Yelle, R. V.; Cui, J.; Wahlund, J.-E.; Edberg, N. J. T.; Ågren, K.

2013-09-01

We derive vertical temperature profiles from Ion Neutral Mass Spectrometer (INMS) N2 density measurements from 32 Cassini passes. We find that the average temperature of Titan’s thermosphere varies significantly from pass-to-pass between 112 and 175 K. The temperatures from individual temperature profiles also varies considerably, with many passes exhibiting wave-like temperature perturbations and large temperature gradients. Wave-like temperature perturbations have wavelengths between 150 and 420 km and amplitudes between 3% and 22% and vertical wave power spectra of the INMS data and HASI data have a slope between -2 and -3, which is consistent with vertically propagating atmospheric waves. The lack of a strong correlation between temperature and latitude, longitude, solar zenith angle, or local solar time indicates that the thermal structure of Titan’s thermosphere is not primarily determined by the absorption of solar EUV flux. At N2 densities greater than 108 cm-3, Titan’s thermosphere is colder when Titan is observed in Saturn’s magnetospheric lobes compared to Saturn’s plasma sheet as proposed by Westlake et al. (Westlake, J.H. et al. [2011]. J. Geophys. Res. 116, A03318. http://dx.doi.org/10.1029/2010JA016251). This apparent correlation suggests that magnetospheric particle precipitation causes the temperature variability in Titan’s thermosphere; however, at densities smaller than 108 cm-3 the lobe passes are hotter than the plasma sheet passes and we find no correlation between the temperature of Titan’s thermosphere and ionospheric signatures of enhanced particle precipitation, which suggests that the correlation is not indicative of a physical connection. The temperature of Titan’s thermosphere also may have decreased by ∼10 K around mid-2007. Finally, we classify the vertical temperature profiles to show which passes are hot and cold and which passes have the largest temperature variations. In a companion paper (Part II), we estimate the strength of energy sources and sinks in Titan’s thermosphere.

Pleuroparenchymal fibroelastosis: report of two cases in Brazil.

PubMed

Gomes, Paula Silva; Shiang, Christina; Szarf, Gilberto; Coletta, Ester Nei Aparecida Martins; Pereira, Carlos Alberto de Castro

2017-01-01

Pleuroparenchymal fibroelastosis (PPFE) is a rare lung disease. It can be idiopathic or associated with any one of various conditions. To our knowledge, this is the first report of two cases of PPFE in Brazil. Our first patient presented with pleural and subpleural fibrosis in the upper lobes; a spiculated nodule in the left upper lobe; and a mild reticular pattern in the lower lobes. Surgical lung biopsy revealed PPFE in the upper lobes, including the nodule, and unclassified interstitial pneumonia in the left lower lobe. Our second patient had a history of exposure to domestic birds, indicating a risk of hypersensitivity pneumonitis, and presented with advanced lung disease, predominantly in the upper lobes, together with subpleural fibrosis.That patient underwent lung transplantation. In the explant specimen, PPFE and granulomas were identified, suggesting hypersensitivity pneumonitis as an associated cause. RESUMO A fibroelastose pleuroparenquimatosa (FEPP) é uma doença pulmonar rara, podendo ser idiopática ou associada a diversas condições. Pelo que sabemos, este é o primeiro relato de dois casos de FEPP no Brasil. Nosso primeiro paciente apresentava fibrose pleural e subpleural nos lobos superiores, um nódulo espiculado no lobo superior esquerdo e um padrão reticular discreto nos lobos inferiores. A biópsia pulmonar cirúrgica demonstrou FEPP nos lobos superiores, incluindo no nódulo, e pneumonia intersticial não classificada no lobo inferior esquerdo. Nosso segundo paciente tinha história de exposição a aves domésticas, indicando um risco de pneumonite de hipersensibilidade, e doença pulmonar avançada predominando em lobos superiores, com fibrose subpleural. Esse paciente foi submetido a transplante pulmonar. No espécime do explante, FEPP e granulomas foram identificados, sugerindo pneumonite de hipersensibilidade como causa associada.

An improved schlieren method for measurement and automatic reconstruction of the far-field focal spot

PubMed Central

Wang, Zhengzhou; Hu, Bingliang; Yin, Qinye

2017-01-01

The schlieren method of measuring far-field focal spots offers many advantages at the Shenguang III laser facility such as low cost and automatic laser-path collimation. However, current methods of far-field focal spot measurement often suffer from low precision and efficiency when the final focal spot is merged manually, thereby reducing the accuracy of reconstruction. In this paper, we introduce an improved schlieren method to construct the high dynamic-range image of far-field focal spots and improve the reconstruction accuracy and efficiency. First, a detection method based on weak light beam sampling and magnification imaging was designed; images of the main and side lobes of the focused laser irradiance in the far field were obtained using two scientific CCD cameras. Second, using a self-correlation template matching algorithm, a circle the same size as the schlieren ball was dug from the main lobe cutting image and used to change the relative region of the main lobe cutting image within a 100×100 pixel region. The position that had the largest correlation coefficient between the side lobe cutting image and the main lobe cutting image when a circle was dug was identified as the best matching point. Finally, the least squares method was used to fit the center of the side lobe schlieren small ball, and the error was less than 1 pixel. The experimental results show that this method enables the accurate, high-dynamic-range measurement of a far-field focal spot and automatic image reconstruction. Because the best matching point is obtained through image processing rather than traditional reconstruction methods based on manual splicing, this method is less sensitive to the efficiency of focal-spot reconstruction and thus offers better experimental precision. PMID:28207758

CLINICAL AND IMAGING FEATURES OF OTHELLO'S SYNDROME

PubMed Central

Graff-Radford, Jonathan; Whitwell, Jennifer L.; Geda, Yonas E.; Josephs, Keith A.

2011-01-01

Background Our objective was to document the clinical and imaging features of Othello's syndrome (delusional jealousy). Methods The study design was a retrospective case series of 105 patients with Othello's syndrome that were identified by using the Electronic Medical Record system of Mayo Clinic. Results The average age at onset of Othello's syndrome was 68 (25–94) years with 61.9% of patients being male. Othello's syndrome was most commonly associated with a neurological disorder (73/105) compared with psychiatric disorders (32/105). Of the patients with a neurological disorder, 76.7% had a neurodegenerative disorder. Seven of eight patients with a structural lesion associated with Othello's syndrome had right frontal lobe pathology. Voxel-based morphometry showed greater grey matter loss predominantly in the dorsolateral frontal lobes in the neurodegenerative patients with Othello's compared to matched patients with neurodegenerative disorders without Othello's syndrome. Treatment success was notable for patients with dopamine agonist induced Othello's syndrome in which all six patients had improvement in symptoms following decrease in medication. Conclusions This study demonstrates that Othello's syndrome occurs most frequently with neurological disorders. This delusion appears to be associated with dysfunction of the frontal lobes, especially right frontal lobe. PMID:21518145

Laparoscopic left hepatectomy in swine: a safe and feasible technique.

PubMed

Zhang, Hua; Liu, Tao; Wang, Yue; Liu, Hai-Feng; Zhang, Jian-Tao; Wu, Yan-Shuang; Lei, Lei; Wang, Hong-Bin

2014-01-01

A purely laparoscopic four-port approach was created for left hepatectomy in pigs. A polyethylene loop was placed on the left two hepatic lobes for traction and lift. Next, penetrating ligation of the lobes using of a double row of silk sutures was performed to control bleeding. A direct hepatic transection was completed using a monopolar hook electrode without meticulous dissection of the left hepatic vein. The raw surface of the liver was coagulated and sealed with fibrin glue. Lobes were retrieved through an enlarged portal. Laparoscopic hepatic lobectomy was completed in all pigs without the use of specialized instruments and with a mean operative time of 179 ± 9 min. No significant perioperative complications were observed. The average weight of each resected lobe was 180 ± 51 g. Complete blood count as well as serum organics and enzyme levels normalized after about 2 weeks. During necropsy, adhesion of the hepatic raw surface to the gastric wall and omentum were observed. No other abnormalities were identified. This minimally invasive left hepatectomy technique in swine could serve as a useful model for investigating liver diseases and regeneration, and offer preclinical information to improve hepatobiliary surgical procedures.

The pattern of parallel edge plasma flows due to pressure gradients, recycling, and resonant magnetic perturbations in DIII-D

DOE PAGES

Frerichs, H.; Schmitz, Oliver; Evans, Todd; ...

2015-07-13

High resolution plasma transport simulations with the EMC3-EIRENE code have been performed to address the parallel plasma flow structure in the boundary of a poloidal divertor configuration with non-axisymmetric perturbations at DIII-D. Simulation results show that a checkerboard pattern of flows with alternating direction is generated inside the separatrix. This pattern is aligned with the position of the main resonances (i.e. where the safety factor is equal to rational values q = m/n for a perturbation field with base mode number n): m pairs of alternating forward and backward flow channel exist for each resonance. The poloidal oscillations are alignedmore » with the subharmonic Melnikov function, which indicates that the plasma flow is generated by parallel pressure gradients along perturbed field lines. Lastly, an additional scrape-off layer-like domain is introduced by the perturbed separatrix which guides field lines from the interior to the divertor targets, resulting in an enhanced outward flow that is consistent with the experimentally observed particle pump-out effect. However, while the lobe structure of the perturbed separatrix is very well reflected in the temperature profile, the same lobes can appear to be smaller in the flow profile due to a competition between high upstream pressure and downstream particle sources driving flows in opposite directions.« less

Proteomic Analysis Reveals Age-related Changes in Tendon Matrix Composition, with Age- and Injury-specific Matrix Fragmentation*

PubMed Central

Peffers, Mandy J.; Thorpe, Chavaunne T.; Collins, John A.; Eong, Robin; Wei, Timothy K. J.; Screen, Hazel R. C.; Clegg, Peter D.

2014-01-01

Energy storing tendons, such as the human Achilles and equine superficial digital flexor tendon (SDFT), are highly prone to injury, the incidence of which increases with aging. The cellular and molecular mechanisms that result in increased injury in aged tendons are not well established but are thought to result in altered matrix turnover. However, little attempt has been made to fully characterize the tendon proteome nor determine how the abundance of specific tendon proteins changes with aging and/or injury. The aim of this study was, therefore, to assess the protein profile of normal SDFTs from young and old horses using label-free relative quantification to identify differentially abundant proteins and peptide fragments between age groups. The protein profile of injured SDFTs from young and old horses was also assessed. The results demonstrate distinct proteomic profiles in young and old tendon, with alterations in the levels of proteins involved in matrix organization and regulation of cell tension. Furthermore, we identified several new peptide fragments (neopeptides) present in aged tendons, suggesting that there are age-specific cleavage patterns within the SDFT. Proteomic profile also differed between young and old injured tendon, with a greater number of neopeptides identified in young injured tendon. This study has increased the knowledge of molecular events associated with tendon aging and injury, suggesting that maintenance and repair of tendon tissue may be reduced in aged individuals and may help to explain why the risk of injury increases with aging. PMID:25077967

Beyond the double banana: improved recognition of temporal lobe seizures in long-term EEG.

PubMed

Rosenzweig, Ivana; Fogarasi, András; Johnsen, Birger; Alving, Jørgen; Fabricius, Martin Ejler; Scherg, Michael; Neufeld, Miri Y; Pressler, Ronit; Kjaer, Troels W; van Emde Boas, Walter; Beniczky, Sándor

2014-02-01

To investigate whether extending the 10-20 array with 6 electrodes in the inferior temporal chain and constructing computed montages increases the diagnostic value of ictal EEG activity originating in the temporal lobe. In addition, the accuracy of computer-assisted spectral source analysis was investigated. Forty EEG samples were reviewed by 7 EEG experts in various montages (longitudinal and transversal bipolar, common average, source derivation, source montage, current source density, and reference-free montages) using 2 electrode arrays (10-20 and the extended one). Spectral source analysis used source montage to calculate density spectral array, defining the earliest oscillatory onset. From this, phase maps were calculated for localization. The reference standard was the decision of the multidisciplinary epilepsy surgery team on the seizure onset zone. Clinical performance was compared with the double banana (longitudinal bipolar montage, 10-20 array). Adding the inferior temporal electrode chain, computed montages (reference free, common average, and source derivation), and voltage maps significantly increased the sensitivity. Phase maps had the highest sensitivity and identified ictal activity at earlier time-point than visual inspection. There was no significant difference concerning specificity. The findings advocate for the use of these digital EEG technology-derived analysis methods in clinical practice.

Accelerated long-term forgetting and autobiographical memory disorders in temporal lobe epilepsy: One entity or two?

PubMed

Lemesle, B; Planton, M; Pagès, B; Pariente, J

Temporal lobe epilepsy (TLE) is a type of epilepsy that often has a negative impact on patients' memory. Despite the importance of patients' complaints in this regard, the difficulties described by these patients are often not easy to demonstrate through a standard neuropsychological assessment. Accelerated long-term forgetting and autobiographical memory disorders are the two main memory impairments reported in the literature in patients with TLE. However, the methods used by different authors to evaluate long-term memory and autobiographical memory are heterogeneous. This heterogeneity can lead to differences in the observed results as well as how they are interpreted. Yet, despite the methodological differences, objectification of such memory deficits appears to be both specific and robust within this patient population. Analysis of the literature shows that accelerated long-term forgetting and autobiographical memory disorders share the same clinical characteristics. This leads to the assumption that they are, in fact, only one entity and that their evaluation may be done through a single procedure. Our proposal is to place this evaluation within the context of memory consolidation disorders. With such a perspective, evaluation of accelerated forgetting in autobiographical memory should consist of identifying a disorder in the formation and/or recovery of new memory traces. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Suicidality in temporal lobe epilepsy: measuring the weight of impulsivity and depression.

PubMed

de Oliveira, Guilherme Nogueira M; Kummer, Arthur; Salgado, João Vinícius; Filho, Gerardo Maria de Araújo; David, Anthony S; Teixeira, Antônio Lúcio

2011-12-01

The aim of the work described here was to measure the role of psychopathological features, specifically impulsivity and depression, in suicidality in patients with temporal lobe epilepsy (TLE). Neuropsychiatric evaluation of 66 outpatients with TLE was performed with the following instruments: a structured clinical interview (Mini International Neuropsychiatric Interview Plus), the Barratt Impulsiveness Scale, the Hamilton Anxiety Scale, the Beck Depression Inventory, and the Brief Psychiatric Rating Scale. A current Axis I psychiatric diagnosis, mainly mood and anxiety disorders, was assigned to 37 subjects (56.1%) Presence of suicide risk was identified in 19 patients (28.8%), and 14 (21.2%) had attempted suicide. Frequency of seizures (P=0.012), current major depression (P=0.001), and motor impulsivity (P=0.005) were associated with suicide risk on univariate analysis. Logistic regression stressed the main relevance of major depression (OR=12.82, 95% CI=2.58-63.76, P=0.002) and motor impulsivity (OR=1.21, 95% CI=1.06-1.38, P=0.005) to suicide risk. Depression has a major influence on suicidality in epilepsy. Motor impulsivity is also relevant and may be an important component of depression in TLE associated with suicide risk. Copyright © 2011 Elsevier Inc. All rights reserved.

Multichannel continuous electroencephalography-functional near-infrared spectroscopy recording of focal seizures and interictal epileptiform discharges in human epilepsy: a review

PubMed Central

Peng, Ke; Pouliot, Philippe; Lesage, Frédéric; Nguyen, Dang Khoa

2016-01-01

Abstract. Functional near-infrared spectroscopy (fNIRS) has emerged as a promising neuroimaging technique as it allows noninvasive and long-term monitoring of cortical hemodynamics. Recent work by our group and others has revealed the potential of fNIRS, combined with electroencephalography (EEG), in the context of human epilepsy. Hemodynamic brain responses attributed to epileptic events, such as seizures and interictal epileptiform discharges (IEDs), are routinely observed with a good degree of statistical significance and in concordance with clinical presentation. Recording done with over 100 channels allows sufficiently large coverage of the epileptic focus and other areas. Three types of seizures have been documented: frontal lobe seizures, temporal lobe seizures, and posterior seizures. Increased oxygenation was observed in the epileptic focus in most cases, while rapid but similar hemodynamic variations were identified in the contralateral homologous region. While investigating IEDs, it was shown that their hemodynamic effect is observable with fNIRS, that their response is associated with significant (inhibitive) nonlinearities, and that the sensitivity and specificity of fNIRS to localize the epileptic focus can be estimated in a sample of 40 patients. This paper first reviews recent EEG-fNIRS developments in epilepsy research and then describes applications to the study of focal seizures and IEDs. PMID:26958576

Brain system for mental orientation in space, time, and person.

PubMed

Peer, Michael; Salomon, Roy; Goldberg, Ilan; Blanke, Olaf; Arzy, Shahar

2015-09-01

Orientation is a fundamental mental function that processes the relations between the behaving self to space (places), time (events), and person (people). Behavioral and neuroimaging studies have hinted at interrelations between processing of these three domains. To unravel the neurocognitive basis of orientation, we used high-resolution 7T functional MRI as 16 subjects compared their subjective distance to different places, events, or people. Analysis at the individual-subject level revealed cortical activation related to orientation in space, time, and person in a precisely localized set of structures in the precuneus, inferior parietal, and medial frontal cortex. Comparison of orientation domains revealed a consistent order of cortical activity inside the precuneus and inferior parietal lobes, with space orientation activating posterior regions, followed anteriorly by person and then time. Core regions at the precuneus and inferior parietal lobe were activated for multiple orientation domains, suggesting also common processing for orientation across domains. The medial prefrontal cortex showed a posterior activation for time and anterior for person. Finally, the default-mode network, identified in a separate resting-state scan, was active for all orientation domains and overlapped mostly with person-orientation regions. These findings suggest that mental orientation in space, time, and person is managed by a specific brain system with a highly ordered internal organization, closely related to the default-mode network.

The emplacement of long lava flows in Mare Imbrium, the Moon

NASA Astrophysics Data System (ADS)

Garry, W. B.

2012-12-01

Lava flow margins are scarce on the lunar surface. The best developed lava flows on the Moon occur in Mare Imbrium where flow margins are traceable nearly their entire flow length. The flow field originates in the southwest part of the basin from a fissure or series of fissures and cones located in the vicinity of Euler crater and erupted in three phases (Phases I, II, III) over a period of 0.5 Billion years (3.0 - 2.5 Ga). The flow field was originally mapped with Apollo and Lunar Orbiter data by Schaber (1973) and shows the flow field extends 200 to 1200 km from the presumed source area and covers an area of 2.0 x 10^5 km^2 with an estimated eruptive volume of 4 x 10^4 km^3. Phase I flows extend 1200 km and have the largest flow volume, but interestingly do not exhibit visible topography and are instead defined by difference in color from the surrounding mare flows. Phases II and III flows have well-defined flow margins (10 - 65 m thick) and channels (0.4 - 2.0 km wide, 40 - 70 m deep), but shorter flow lengths, 600 km and 400 km respectively. Recent missions, including Lunar Reconnaissance Orbiter (LRO), Kaguya (Selene), and Clementine, provide high resolution data sets of these lava flows. Using a combination of data sets including images from LRO Wide-Angle-Camera (WAC)(50-100 m/pixel) and Narrow-Angle-Camera (NAC) (up to 0.5m/pixel), Kaguya Terrain Camera (TC) (10 m/pixel), and topography from LRO Lunar Orbiter Laser Altimeter (LOLA), the morphology has been remapped and topographic measurements of the flow features have been made in an effort to reevaluate the emplacement of the flow field. Morphologic mapping reveals a different flow path for Phase I compared to the original mapping completed by Schaber (1973). The boundaries of the Phase I flow field have been revised based on Moon Mineralogy Mapper color ratio images (Staid et al., 2011). This has implications for the area covered and volume erupted during this stage, as well as, the age of Phase I. Flow features and margins have been identified in the Phase I flow within the LROC WAC mosaic and in Narrow Angle Camera (NAC) images. These areas have a mottled appearance. LOLA profiles over the more prominent flow lobes in Phase I reveal these margins are less 10 m thick. Phase II and III morphology maps are similar to previous flow maps. Phase III lobes near Euler are 10-12 km wide and 20-30 m thick based on measurements of the LOLA 1024ppd Elevation Digital Terrain Model (DTM) in JMoon. One of the longer Phase III lobes varies between 15 to 50 km wide and 25 to 60 m thick, with the thickest section at the distal end of the lobe. The Phase II lobe is 15 to 25 m thick and up to 35 km wide. The eruptive volume of the Mare Imbrium lava flows has been compared to terrestrial flood basalts. The morphology of the lobes in Phase II and III, which includes levees, thick flow fronts, and lobate margins suggests these could be similar to terrestrial aa-style flows. The Phase I flows might be more representative of sheet flows, pahoehoe-style flows, or inflated flows. Morphologic comparisons will be made with terrestrial flows at Askja volcano in Iceland, a potential analog to compare different styles of emplacement for the flows in Mare Imbrium.

Multidimensional Characterization of Sexual Minority Adolescents’ Sexual Safety Strategies

PubMed Central

Masters, N. Tatiana; Beadnell, Blair; Morrison, Diane M.; Hoppe, Marilyn J.; Wells, Elizabeth A.

2013-01-01

Young adults have high rates of sexually transmitted infections (STIs). Sexual minority youths’ risk for STIs, including HIV, is as high as or higher than sexual majority peers’. Sexual safety, while often treated as a single behavior such as condom use, can be best conceptualized as the result of multiple factors. We used latent class analysis to identify profiles based on ever-used sexual safety strategies and lifetime number of partners among 425 self-identified LGBTQ youth aged 14-19. Data collection took place anonymously online. We identified four specific subgroup profiles for males and three for females, with each subgroup representing a different level and type of sexual safety. Profiles differed from each other in terms of age and outness for males, and in outness, personal homonegativity, and amount of education received about sexual/romantic relationships for females. Youths’ sexual safety profiles have practice implications for sexuality educators, health care professionals, and parents. PMID:24011111

Specific retention of the protostome-specific PsGEF may parallel with the evolution of mushroom bodies in insect and lophotrochozoan brains.

PubMed

Higuchi, Nozomu; Kohno, Keigo; Kadowaki, Tatsuhiko

2009-05-07

Gene gain and subsequent retention or loss during evolution may be one of the underlying mechanisms involved in generating the diversity of metazoan nervous systems. However, the causal relationships acting therein have not been studied extensively. We identified the gene PsGEF (protostome-specific GEF), which is present in all the sequenced genomes of insects and limpet but absent in those of sea anemones, deuterostomes, and nematodes. In Drosophila melanogaster, PsGEF encodes a short version of a protein with the C2 and PDZ domains, as well as a long version with the C2, PDZ, and RhoGEF domains through alternative splicing. Intriguingly, the exons encoding the RhoGEF domain are specifically deleted in the Daphnia pulex genome, suggesting that Daphnia PsGEF contains only the C2 and PDZ domains. Thus, the distribution of PsGEF containing the C2, PDZ, and RhoGEF domains among metazoans appears to coincide with the presence of mushroom bodies. Mushroom bodies are prominent neuropils involved in the processing of multiple sensory inputs as well as associative learning in the insect, platyhelminth, and annelid brains. In the adult Drosophila brain, PsGEF is expressed in mushroom bodies, antennal lobe, and optic lobe, where it is necessary for the correct axon branch formation of alpha/beta neurons in mushroom bodies. PsGEF genetically interacts with Rac1 but not other Rho family members, and the RhoGEF domain of PsGEF induces actin polymerization in the membrane, thus resulting in the membrane ruffling that is observed in cultured cells with activated forms of Rac. The specific acquisition of PsGEF by the last common ancestor of protostomes followed by its retention or loss in specific animal species during evolution demonstrates that there are some structural and/or functional features common between insect and lophotrochozoan nervous systems (for example, mushroom bodies), which are absent in all deuterostomes and cnidarians. PsGEF is therefore one of genes associated with the diversity of metazoan nervous systems.

Immunocytochemical Mapping of an RDL-Like GABA Receptor Subunit and of GABA in Brain Structures Related to Learning and Memory in the Cricket Acheta domesticus

PubMed Central

Strambi, Colette; Cayre, Myriam; Sattelle, David B.; Augier, Roger; Charpin, Pierre; Strambi, Alain

1998-01-01

The distribution of putative RDL-like GABA receptors and of γ-aminobutyric acid (GABA) in the brain of the adult house cricket Acheta domesticus was studied using specific antisera. Special attention was given to brain structures known to be related to learning and memory. The main immunostaining for the RDL-like GABA receptor was observed in mushroom bodies, in particular the upper part of mushroom body peduncle and the two arms of the posterior calyx. Weaker immunostaining was detected in the distal part of the peduncle and in the α and β lobes. The dorso- and ventrolateral protocerebrum neuropils appeared rich in RDL-like GABA receptors. Staining was also detected in the glomeruli of the antennal lobe, as well as in the ellipsoid body of the central complex. Many neurons clustered in groups exhibit GABA-like immunoreactivity. Tracts that were strongly immunostained innervated both the calyces and the lobes of mushroom bodies. The glomeruli of the antennal lobe, the ellipsoid body, as well as neuropils of the dorso- and ventrolateral protocerebrum were also rich in GABA-like immuno- reactivity. The data demonstrated a good correlation between the distribution of the GABA-like and of the RDL-like GABA receptor immunoreactivity. The prominent distribution of RDL-like GABA receptor subunits, in particular areas of mushroom bodies and antennal lobes, underlines the importance of inhibitory signals in information processing in these major integrative centers of the insect brain. PMID:10454373

Crystal structure of an SH2-kinase construct of c-Abl and effect of the SH2 domain on kinase activity.

PubMed

Lorenz, Sonja; Deng, Patricia; Hantschel, Oliver; Superti-Furga, Giulio; Kuriyan, John

2015-06-01

Constitutive activation of the non-receptor tyrosine kinase c-Abl (cellular Abelson tyrosine protein kinase 1, Abl1) in the Bcr (breakpoint cluster region)-Abl1 fusion oncoprotein is the molecular cause of chronic myeloid leukaemia (CML). Recent studies have indicated that an interaction between the SH2 (Src-homology 2) domain and the N-lobe (N-terminal lobe) of the c-Abl kinase domain (KD) has a critical role in leukaemogenesis [Grebien et al. (2011) Cell 147, 306-319; Sherbenou et al. (2010) Blood 116, 3278-3285]. To dissect the structural basis of this phenomenon, we studied c-Abl constructs comprising the SH2 and KDs in vitro. We present a crystal structure of an SH2-KD construct bound to dasatinib, which contains the relevant interface between the SH2 domain and the N-lobe of the KD. We show that the presence of the SH2 domain enhances kinase activity moderately and that this effect depends on contacts in the SH2/N-lobe interface and is abrogated by specific mutations. Consistently, formation of the interface decreases slightly the association rate of imatinib with the KD. That the effects are small compared with the dramatic in vivo consequences suggests an important function of the SH2-N-lobe interaction might be to help disassemble the auto-inhibited conformation of c-Abl and promote processive phosphorylation, rather than substantially stimulate kinase activity.

Fibrosis in nonalcoholic fatty liver disease: Noninvasive assessment using computed tomography volumetry.

PubMed

Fujita, Nobuhiro; Nishie, Akihiro; Asayama, Yoshiki; Ishigami, Kousei; Ushijima, Yasuhiro; Takayama, Yukihisa; Okamoto, Daisuke; Shirabe, Ken; Yoshizumi, Tomoharu; Kotoh, Kazuhiro; Furusyo, Norihiro; Hida, Tomoyuki; Oda, Yoshinao; Fujioka, Taisuke; Honda, Hiroshi

2016-10-28

To evaluate the diagnostic performance of computed tomography (CT) volumetry for discriminating the fibrosis stage in patients with nonalcoholic fatty liver disease (NAFLD). A total of 38 NAFLD patients were enrolled. On the basis of CT imaging, the volumes of total, left lateral segment (LLS), left medial segment, caudate lobe, and right lobe (RL) of the liver were calculated with a dedicated liver application. The relationship between the volume percentage of each area and fibrosis stage was analyzed using Spearman's rank correlation coefficient. A receiver operating characteristic (ROC) curve analysis was performed to determine the accuracy of CT volumetry for discriminating fibrosis stage. The volume percentages of the caudate lobe and the LLS significantly increased with the fibrosis stage ( r = 0.815, P < 0.001; and r = 0.465, P = 0.003, respectively). Contrarily, the volume percentage of the RL significantly decreased with fibrosis stage ( r = -0.563, P < 0.001). The volume percentage of the caudate lobe had the best diagnostic accuracy for staging fibrosis, and the area under the ROC curve values for discriminating fibrosis stage were as follows: ≥ F1, 0.896; ≥ F2, 0.929; ≥ F3, 0.955; and ≥ F4, 0.923. The best cut-off for advanced fibrosis (F3-F4) was 4.789%, 85.7% sensitivity and 94.1% specificity. The volume percentage of the caudate lobe calculated by CT volumetry is a useful diagnostic parameter for staging fibrosis in NAFLD patients.

[Differences and similarities between the competencies of a nursing supervisor and an advanced clinical nurse specialist].

PubMed

del Barrio-Linares, M; Pumar-Méndez, M J

2015-01-01

With the aim of contributing to the development of a more specific professional regulation, the present study was to identify differences and similarities between the competencies of the nursing supervisor and clinical nurse specialist in an intensive care unit. A critical analysis of the literature published between 2003 and 2013 was conducted, identified through systematic searches in electronic databases, health management and practitioner journals and reference lists of the 17 items included. «Management and administration» and «direct clinical practice» were identified as specific competencies of nursing supervisor and clinical nurse specialist respectively. «Collaboration», «leadership» and «research» emerged as competencies shared by both profiles, but with different a operationalization way of conducting it. These findings imply that regulation, education and implementation of these profiles must address their specific skills as the distinctive approach taken in operationalizing shared. Copyright © 2014 Elsevier España, S.L.U. y SEEIUC. All rights reserved.

Identification of osteosarcoma-related specific proteins in serum samples using surface-enhanced laser desorption/ionization-time-of-flight mass spectrometry.

PubMed

Gu, Jianli; Li, Jitian; Huang, Manyu; Zhang, Zhiyong; Li, Dongsheng; Song, Guoying; Ding, Xingpo; Li, Wuyin

2014-01-01

Osteosarcoma (OS) is the most common malignant bone tumor. To identify OS-related specific proteins for early diagnosis of OS, a novel approach, surface-enhanced laser desorption/ionization-time-of-flight mass spectrometry (SELDI-TOF-MS) to serum samples from 25 OS patients, 16 osteochondroma, and 26 age-matched normal human volunteers as controls, was performed. Two proteins showed a significantly different expression in OS serum samples from control groups. Proteomic profiles and external leave-one-out cross-validation analysis showed that the correct rate of allocation, the sensitivity, and the specificity of diagnosis were 100%. These two proteins were further identified by searching the EPO-KB database, and one of the proteins identified as Serine rich region profile is involved in various cellular signaling cascades and tumor genesis. The presence of these two proteins in OS patients but absence from premalignant and normal human controls implied that they can be potential biomarkers for early diagnosis of OS.

Mental hoop diaries: Emotional memories of a college basketball game in rival fans

PubMed Central

Botzung, Anne; Rubin, David C.; Miles, Amanda; Cabeza, Roberto; LaBar, Kevin S.

2012-01-01

The rivalry between the men’s basketball teams of Duke University and the University of North Carolina-Chapel Hill (UNC) is one of the most storied traditions in college sports. A subculture of students at each university form social bonds with fellow fans, develop expertise in college basketball rules, team statistics, and individual players, and self-identify as a member of a fan group. The present study capitalized on the high personal investment of these fans and the strong affective tenor of a Duke-UNC basketball game to examine the neural correlates of emotional memory retrieval for a complex sporting event. Male fans watched a competitive, archived game in a social setting. During a subsequent functional magnetic resonance imaging session, participants viewed video clips depicting individual plays of the game that ended with the ball being released towards the basket. For each play, participants recalled whether or not the shot went into the basket. Hemodynamic signal changes time-locked to correct memory decisions were analyzed as a function of emotional intensity and valence, according to the fan’s perspective. Results showed intensity-modulated retrieval activity in midline cortical structures, sensorimotor cortex, the striatum, and the medial temporal lobe, including the amygdala. Positively-valent memories specifically recruited processing in dorsal frontoparietal regions, and additional activity in the insula and medial temporal lobe for positively-valent shots recalled with high confidence. This novel paradigm reveals how brain regions implicated in emotion, memory retrieval, visuomotor imagery, and social cognition contribute to the recollection of specific plays in the mind of a sports fan. PMID:20147540

Are numbers grounded in a general magnitude processing system? A functional neuroimaging meta-analysis.

PubMed

Sokolowski, H Moriah; Fias, Wim; Bosah Ononye, Chuka; Ansari, Daniel

2017-10-01

It is currently debated whether numbers are processed using a number-specific system or a general magnitude processing system, also used for non-numerical magnitudes such as physical size, duration, or luminance. Activation likelihood estimation (ALE) was used to conduct the first quantitative meta-analysis of 93 empirical neuroimaging papers examining neural activation during numerical and non-numerical magnitude processing. Foci were compiled to generate probabilistic maps of activation for non-numerical magnitudes (e.g. physical size), symbolic numerical magnitudes (e.g. Arabic digits), and nonsymbolic numerical magnitudes (e.g. dot arrays). Conjunction analyses revealed overlapping activation for symbolic, nonsymbolic and non-numerical magnitudes in frontal and parietal lobes. Contrast analyses revealed specific activation in the left superior parietal lobule for symbolic numerical magnitudes. In contrast, small regions in the bilateral precuneus were specifically activated for nonsymbolic numerical magnitudes. No regions in the parietal lobes were activated for non-numerical magnitudes that were not also activated for numerical magnitudes. Therefore, numbers are processed using both a generalized magnitude system and format specific number regions. Copyright © 2017 Elsevier Ltd. All rights reserved.

Hippocampal and prefrontal cortex contributions to learning and memory: analysis of lesion and aging effects on maze learning in rats.

PubMed

Winocur, G; Moscovitch, M

1990-08-01

Young adult rats with bilateral lesions to the hippocampus or prefrontal cortex, young operated controls, and normal old rats were tested on two complex mazes in the Hebb-Williams series. Approximately half the animals were previously trained on one of the mazes; the remainder received no previous training. The trained hippocampal rats showed sparing of memory for the general skill of maze learning but poor recall of the specific maze on which they had been previously trained. The opposite pattern was observed in trained prefrontal rats. In contrast, the aged rats' memory for maze-specific and maze-general information was impaired. The results confirmed the importance of the hippocampus for recalling highly specific information and pointed to a possible role for the frontal lobes in learning and remembering nonspecific skill-related information. The generalized deficit of the aged rats indicates that both types of memory were compromised and offers further evidence of frontal lobe and hippocampal dysfunction in normal aging.

Mindfulness and Psychological Health Outcomes: A Latent Profile Analysis among Military Personnel and College Students.

PubMed

Bravo, Adrian J; Pearson, Matthew R; Kelley, Michelle L

2018-02-01

Previous research on trait mindfulness facets using person-centered analyses (e.g., latent profile analysis [LPA]) has identified four distinct mindfulness profiles among college students: a high mindfulness group (high on all facets of the Five-Factor Mindfulness Questionnaire [FFMQ]), a judgmentally observing group (highest on observing, but low on non-judging of inner experience and acting with awareness), a non-judgmentally aware group (high on non-judging of inner experience and acting with awareness, but very low on observing), and a low mindfulness group (low on all facets of the FFMQ). In the present study, we used LPA to identify distinct mindfulness profiles in a community based sample of U.S. military personnel (majority veterans; n = 407) and non-military college students ( n = 310) and compare these profiles on symptoms of psychological health outcomes (e.g., suicidality, PTSD, anxiety, rumination) and percentage of participants exceeding clinically significant cut-offs for depressive symptoms, substance use, and alcohol use. In the subsample of college students, we replicated previous research and found four distinct mindfulness profiles; however, in the military subsample we found three distinct mindfulness profiles (a combined low mindfulness/judgmentally observing class). In both subsamples, we found that the most adaptive profile was the "high mindfulness" profile (i.e., demonstrated the lowest scores on all psychological symptoms and the lowest probability of exceeding clinical cut-offs). Based on these findings, we purport that the comprehensive examination of an individual's mindfulness profile could help clinicians tailor interventions/treatments that capitalize on individual's specific strengths and work to address their specific deficits.

New Members in the Galaxy Group Around Giant Radio Galaxy DA 240

NASA Astrophysics Data System (ADS)

Chen, Ru-Rong; Peng, Bo; Strom, Richard

2018-05-01

With new spectroscopic observations of group candidates around the giant radio galaxy DA 240, we have identified five new group members, increasing the number to twenty-five. While all the new members are located some distance from the host galaxy, two of them lie in one of the radio lobes, and the rest are found at a distance from the radio components. The new group members reinforce our earlier conclusion that the distribution of the DA 240 group with respect to the radio lobes is unusual among giant radio galaxy host environments.

The frontal lobe and aggression

PubMed Central

Séguin, Jean R.

2014-01-01

Frontal lesions often lead to psychosocial problems. It is not surprising that frontal lobe dysfunctions have been proposed to underlie antisocial behaviour in individuals without apparent lesions. However, physical aggression and violence have never been systematically related to acquired lesions. Whereas, traditional neuropsychological testing identifies problems in cognitive and emotional information processing, recent brain-imaging studies have revealed both the frontal structural and functional underpinnings of antisocial behaviour. Careful characterization of antisocial behaviour subtypes seems to indicate that cognitive-neuropsychological function is systematically poor in physical aggression and hyperactivity. Recent refinements point to biological and genetic moderators of that association. PMID:24976846

Dlx1 and Rgs5 in the Ductus Arteriosus: Vessel-Specific Genes Identified by Transcriptional Profiling of Laser-Capture Microdissected Endothelial and Smooth Muscle Cells

PubMed Central

Bökenkamp, Regina; van Brempt, Ronald; van Munsteren, Jacoba Cornelia; van den Wijngaert, Ilse; de Hoogt, Ronald; Finos, Livio; Goeman, Jelle; Groot, Adriana Cornelia Gittenberger-de; Poelmann, Robert Eugen; Blom, Nicolaas Andreas; DeRuiter, Marcus Cornelis

2014-01-01

Closure of the ductus arteriosus (DA) is a crucial step in the transition from fetal to postnatal life. Patent DA is one of the most common cardiovascular anomalies in children with significant clinical consequences especially in premature infants. We aimed to identify genes that specify the DA in the fetus and differentiate it from the aorta. Comparative microarray analysis of laser-captured microdissected endothelial (ECs) and vascular smooth muscle cells (SMCs) from the DA and aorta of fetal rats (embryonic day 18 and 21) identified vessel-specific transcriptional profiles. We found a strong age-dependency of gene expression. Among the genes that were upregulated in the DA the regulator of the G-protein coupled receptor 5 (Rgs5) and the transcription factor distal-less homeobox 1 (Dlx1) exhibited the highest and most significant level of differential expression. The aorta showed a significant preferential expression of the Purkinje cell protein 4 (Pcp4) gene. The results of the microarray analysis were validated by real-time quantitative PCR and immunohistochemistry. Our study confirms vessel-specific transcriptional profiles in ECs and SMCs of rat DA and aorta. Rgs5 and Dlx1 represent novel molecular targets for the regulation of DA maturation and closure. PMID:24489801

Investigations regarding the evaluation of specific intellectual property production risks within Quality Management System

NASA Astrophysics Data System (ADS)

Pakocs, R.; Lupulescu, N. B.

2016-11-01

This paper is a theoretical research concerning methods for risk assessment of specific intellectual property production risks that are identified in the product achievement stage within the Quality Management System. In order to realize this, we will start by identifying the specific intellectual property production risks and by proposing some new calculating formulas for minimalizing their negative effects. The theoretical model proposed assessment of specific intellectual property production risks, will be realized based on 3 hypothetical situations. This study intends to reduce the intellectual property risks identified in the production process of commercial societies that have an industrial profile.

Segmentation of the Cingulum Bundle in the Human Brain: A New Perspective Based on DSI Tractography and Fiber Dissection Study.

PubMed

Wu, Yupeng; Sun, Dandan; Wang, Yong; Wang, Yibao; Ou, Shaowu

2016-01-01

The cingulum bundle (CB) is a critical white matter fiber tract in the brain, which forms connections between the frontal lobe, parietal lobe and temporal lobe. In non-human primates, the CB is actually divided into distinct subcomponents on the basis of corticocortical connections. However, at present, no study has verified similar distinct subdivisions in the human brain. In this study, we reconstructed these distinct subdivisions in the human brain, and determined their exact cortical connections using high definition fiber tracking (HDFT) technique on 10 healthy adults and a 488-subject template from the Human Connectome Project (HCP-488). Fiber dissections were performed to verify tractography results. Five CB segments were identified. CB-I ran from the subrostral areas to the precuneus and splenium, encircling the corpus callosum (CC). CB-II arched around the splenium and extended anteriorly above the CC to the medial aspect of the superior frontal gyrus (SFG). CB-III connected the superior parietal lobule (SPL) and precuneus with the medial aspect of the SFG. CB-IV was a relatively minor subcomponent from the SPL and precuneus to the frontal region. CB-V, the para-hippocampal cingulum, stemmed from the medial temporal lobe and fanned out to the occipital lobes. Our findings not only provide a more accurate and detailed description on the associated architecture of the subcomponents within the CB, but also offer new insights into the functional role of the CB in the human brain.

Perirhinal cortex and temporal lobe epilepsy

PubMed Central

Biagini, Giuseppe; D'Antuono, Margherita; Benini, Ruba; de Guzman, Philip; Longo, Daniela; Avoli, Massimo

2013-01-01

The perirhinal cortex—which is interconnected with several limbic structures and is intimately involved in learning and memory—plays major roles in pathological processes such as the kindling phenomenon of epileptogenesis and the spread of limbic seizures. Both features may be relevant to the pathophysiology of mesial temporal lobe epilepsy that represents the most refractory adult form of epilepsy with up to 30% of patients not achieving adequate seizure control. Compared to other limbic structures such as the hippocampus or the entorhinal cortex, the perirhinal area remains understudied and, in particular, detailed information on its dysfunctional characteristics remains scarce; this lack of information may be due to the fact that the perirhinal cortex is not grossly damaged in mesial temporal lobe epilepsy and in models mimicking this epileptic disorder. However, we have recently identified in pilocarpine-treated epileptic rats the presence of selective losses of interneuron subtypes along with increased synaptic excitability. In this review we: (i) highlight the fundamental electrophysiological properties of perirhinal cortex neurons; (ii) briefly stress the mechanisms underlying epileptiform synchronization in perirhinal cortex networks following epileptogenic pharmacological manipulations; and (iii) focus on the changes in neuronal excitability and cytoarchitecture of the perirhinal cortex occurring in the pilocarpine model of mesial temporal lobe epilepsy. Overall, these data indicate that perirhinal cortex networks are hyperexcitable in an animal model of temporal lobe epilepsy, and that this condition is associated with a selective cellular damage that is characterized by an age-dependent sensitivity of interneurons to precipitating injuries, such as status epilepticus. PMID:24009554

Memory loss and memory reorganization patterns in temporal lobe epilepsy patients undergoing anterior temporal lobe resection, as demonstrated by pre-versus post-operative functional MRI.

PubMed

Limotai, Chusak; McLachlan, Richard S; Hayman-Abello, Susan; Hayman-Abello, Brent; Brown, Suzan; Bihari, Frank; Mirsattari, Seyed M

2018-06-19

This study was aimed to longitudinally assess memory function and whole-brain memory circuit reorganization in patients with temporal lobe epilepsy (TLE) by comparing activation potentials before versus after anterior temporal lobe (ATL) resection. Nineteen patients with medically-intractable TLE (10 left TLE, 9 right TLE) and 15 healthy controls were enrolled. Group analyses were conducted pre- and post-ATL of a novelty complex scene-encoding paradigm comparing areas of blood oxygen-level-dependent (BOLD) signal activations on functional magnetic resonance imaging (fMRI). None of the pre-operative patient characteristics we studied predicted the extent of pre- to post-operative memory loss. On fMRI, extra-temporal activations were detected pre-operatively in both LTLE and RTLE, particularly in the frontal lobe. Greater activations also were noted in the contralateral hippocampus and parahippocampus in both groups. Performing within-subject comparisons, post-op relative to pre-op, pronounced ipsilateral activations were identified in the left parahippocampal gyrus in LTLE, versus the right middle temporal gyrus in RTLE patients. Memory function was impaired pre-operatively but declined after ATL resection in both RTLE and LTLE patients. Post-operative fMRI results indicate possible functional adaptations to ATL loss, primarily occurring within the left parahippocampal gyrus versus right middle temporal gyrus in LTLE versus RTLE patients, respectively. Copyright © 2018 Elsevier Ltd. All rights reserved.