Mid-callosal plane determination using preferred directions from diffusion tensor images

NASA Astrophysics Data System (ADS)

Costa, André L.; Rittner, Letícia; Lotufo, Roberto A.; Appenzeller, Simone

2015-03-01

The corpus callosum is the major brain structure responsible for inter{hemispheric communication between neurons. Many studies seek to relate corpus callosum attributes to patient characteristics, cerebral diseases and psychological disorders. Most of those studies rely on 2D analysis of the corpus callosum in the mid-sagittal plane. However, it is common to find conflicting results among studies, once many ignore methodological issues and define the mid-sagittal plane based on precary or invalid criteria with respect to the corpus callosum. In this work we propose a novel method to determine the mid-callosal plane using the corpus callosum internal preferred diffusion directions obtained from diffusion tensor images. This plane is analogous to the mid-sagittal plane, but intended to serve exclusively as the corpus callosum reference. Our method elucidates the great potential the directional information of the corpus callosum fibers have to indicate its own referential. Results from experiments with five image pairs from distinct subjects, obtained under the same conditions, demonstrate the method effectiveness to find the corpus callosum symmetric axis relative to the axial plane.

The Role of Corpus Callosum Development in Functional Connectivity and Cognitive Processing

PubMed Central

Findlay, Anne M.; Honma, Susanne; Jeremy, Rita J.; Strominger, Zoe; Bukshpun, Polina; Wakahiro, Mari; Brown, Warren S.; Paul, Lynn K.; Barkovich, A. James; Mukherjee, Pratik; Nagarajan, Srikantan S.; Sherr, Elliott H.

2012-01-01

The corpus callosum is hypothesized to play a fundamental role in integrating information and mediating complex behaviors. Here, we demonstrate that lack of normal callosal development can lead to deficits in functional connectivity that are related to impairments in specific cognitive domains. We examined resting-state functional connectivity in individuals with agenesis of the corpus callosum (AgCC) and matched controls using magnetoencephalographic imaging (MEG-I) of coherence in the alpha (8–12 Hz), beta (12–30 Hz) and gamma (30–55 Hz) bands. Global connectivity (GC) was defined as synchronization between a region and the rest of the brain. In AgCC individuals, alpha band GC was significantly reduced in the dorsolateral pre-frontal (DLPFC), posterior parietal (PPC) and parieto-occipital cortices (PO). No significant differences in GC were seen in either the beta or gamma bands. We also explored the hypothesis that, in AgCC, this regional reduction in functional connectivity is explained primarily by a specific reduction in interhemispheric connectivity. However, our data suggest that reduced connectivity in these regions is driven by faulty coupling in both inter- and intrahemispheric connectivity. We also assessed whether the degree of connectivity correlated with behavioral performance, focusing on cognitive measures known to be impaired in AgCC individuals. Neuropsychological measures of verbal processing speed were significantly correlated with resting-state functional connectivity of the left medial and superior temporal lobe in AgCC participants. Connectivity of DLPFC correlated strongly with performance on the Tower of London in the AgCC cohort. These findings indicate that the abnormal callosal development produces salient but selective (alpha band only) resting-state functional connectivity disruptions that correlate with cognitive impairment. Understanding the relationship between impoverished functional connectivity and cognition is a key step in identifying the neural mechanisms of language and executive dysfunction in common neurodevelopmental and psychiatric disorders where disruptions of callosal development are consistently identified. PMID:22870191

Puberty in the Corpus Callosum

PubMed Central

Chavarria, Mary C.; Sánchez, Francisco J.; Chou, Yi-Yu; Thompson, Paul M.; Luders, Eileen

2014-01-01

Adolescence is an important period for brain development. White matter growth is influenced by sex hormones such as testosterone, and the corpus callosum—the largest white matter structure in the human brain—may change structurally during the hormone-laden period of adolescence. Little is known about puberty’s relationship to structural brain development, even though pubertal stage may better predict cognitive and behavioral maturity than chronological age. We therefore aimed to establish the presence and direction of pubertal effects on callosal anatomy. For this purpose, we applied advanced surface-based mesh-modeling to map correlations between callosal thickness and pubertal stage in a large and well-matched sample of 124 children and adolescents (62 female and 62 male) aged 5–18 years from a normative database. When linking callosal anatomy to pubertal status, only positive correlations reached statistical significance, indicating that callosal growth advances with puberty. In tests of differences in callosal anatomy at different stages of puberty, callosal growth was concentrated in different locations depending on the pubertal stage. Changing levels of circulating sex hormones during different phases of puberty likely contributed to the observed effects, and further research is clearly needed. Direct quantification of sex hormone levels and regional fiber connectivity—ideally using fiber tractography—will reveal whether hormones are the main drivers of callosal change during puberty. These callosal findings may lead to hypotheses regarding cortical changes during puberty, which may promote or result from changes in interhemispheric connectivity. PMID:24468104

Midline corpus callosum is a neuroanatomical focus of fetal alcohol damage.

PubMed

Bookstein, Fred L; Sampson, Paul D; Connor, Paul D; Streissguth, Ann P

2002-06-15

Prenatal exposure to high levels of alcohol often induces birth defects that combine morphological stigmata with neurological or neuropsychological deficits. But it has proved problematic to diagnose these syndromes in adolescents and adults, in whom the morphological signs are absent or attenuated, the behavioral deficits nonspecific, and the exposure history often difficult to reconstruct. Localizing the associated brain abnormalities might circumvent most of these difficulties. To this end, three-dimensional (3D) locations were recorded for 67 homologous points on or near the corpus callosum in magnetic resonance (MR) brain images from 60 adolescents and adults who were normal, 60 diagnosed with fetal alcohol syndrome, and 60 diagnosed with fetal alcohol effects. We combined the standard statistical approach to this type of geometric data, Procrustes analysis, with a multivariate strategy focusing on differences in variability. In this data set, the shape of the corpus callosum and its vicinity proves systematically much more variable in the alcohol-affected brains than in those of the normal subjects. From this excess variability follows a promising classification rule, having both high sensitivity (100 out of 117) and high specificity (49 out of 60) in this sample. The discrimination uses four landmark points and two summary scores of callosal outline shape. The information from the corpus callosum and vicinity, as viewed in MR brain images of full-grown subjects, may serve as a permanent record of the prenatal effects of alcohol, even in patients who are first suspected of these syndromes relatively late in life or who lack the facial signs of prenatal alcohol damage. The statistical pattern underlying the callosal diagnosis also leads to speculations on mechanisms of the prenatal damage. Copyright 2002 Wiley-Liss, Inc.

Dynamic behaviors of growth cones extending in the corpus callosum of living cortical brain slices observed with video microscopy.

PubMed

Halloran, M C; Kalil, K

1994-04-01

During development, axons of the mammalian corpus callosum must navigate across the midline to establish connections with corresponding targets in the contralateral cerebral cortex. To gain insight into how growth cones of callosal axons respond to putative guidance cues along this CNS pathway, we have used time-lapse video microscopy to observe dynamic behaviors of individual callosal growth cones extending in living brain slices from neonatal hamster sensorimotor cortex. Crystals of the lipophilic dye 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate (Dil) were inserted into the cortex in vivo to label small populations of callosal axons and their growth cones. Subsequently, 400 microns brain slices that included the injection site, the corpus callosum, and the target cortex were placed in culture and viewed under low-light-level conditions with a silicon-intensified target (SIT) camera. Time-lapse video observations revealed striking differences in growth cone behaviors in different regions of the callosal pathway. In the tract, which is defined as the region of the callosal pathway from the injection site to the corresponding target cortex, growth cones advanced rapidly, displaying continual lamellipodial shape changes and filopodial exploration. Forward advance was sometimes interrupted by brief pauses or retraction. Growth cones in the target cortex had almost uniform compact shapes that were consistently smaller than those in the tract. In cortex, axons adhered to straight radial trajectories and their growth cones extended at only half the speed of those in the tract. Growth cones in subtarget regions of the callosum beneath cortical targets displayed complex behaviors characterized by long pauses, extension of transitory branches, and repeated cycles of collapse, withdrawal, and resurgence. Video observations suggested that extension of axons into cortical targets could occur by interstitial branching from callosal axons rather than by turning behaviors of the primary growth cones. These results suggest the existence of guidance cues distinct for each of these callosal regions that elicit characteristic growth cone behaviors.

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.

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.

Added Value of Fetal MRI in the Evaluation of Fetal Anomalies of the Corpus Callosum: A Retrospective Analysis of 78 Cases.

PubMed

Manevich-Mazor, Mirra; Weissmann-Brenner, Alina; Bar Yosef, Omer; Hoffmann, Chen; Mazor, Roei David; Mosheva, Mariela; Achiron, Reuven Ryszard; Katorza, Eldad

2018-06-07

 To evaluate the added value of fetal MRI to ultrasound in detecting and specifying callosal anomalies, and its impact on clinical decision making.  Fetuses with a sonographic diagnosis of an anomalous corpus callosum (CC) who underwent a subsequent fetal brain MRI between 2010 and 2015 were retrospectively evaluated and classified according to the severity of the findings. The findings detected on ultrasound were compared to those detected on MRI. An analysis was performed to assess whether fetal MRI altered the group classification, and thus the management of these pregnancies.  78 women were recruited following sonographic diagnoses of either complete or partial callosal agenesis, short, thin or thick CC. Normal MRI studies were obtained inµ19 cases (24 %). Among these, all children available for follow-up received an adequate adaptive score in their Vineland II adaptive behavior scale assessment. Analysis of the concordance between US and MRI demonstrated a substantial level of agreement for complete callosal agenesis (kappa: 0.742), moderate agreement for thin CC (kappa: 0.418) and fair agreement for all other callosal anomalies. Comparison between US and MRI-based mild/severe findings classifications revealed that MRI contributed to a change in the management for 28 fetuses (35.9 %), mostly (25 fetuses, 32.1 %) in favor of pregnancy preservation.  Fetal MRI effectively detects callosal anomalies and enables satisfactory validation of the presence or absence of callosal anomalies identified by ultrasound and adds valuable data that improves clinical decision making. © Georg Thieme Verlag KG Stuttgart · New York.

Paralinguistic Processing in Children with Callosal Agenesis: Emergence of Neurolinguistic Deficits

ERIC Educational Resources Information Center

Brown, W.S.; Symingtion, M.; VanLancker-Sidtis, D.; Dietrich, R.; Paul, L.K.

2005-01-01

Recent research revealed impaired processing of both nonliteral meaning and affective prosody in adults with agenesis of the corpus callosum (ACC) and normal intelligence. Since normal children have incomplete myelination of the corpus callosum, it was hypothesized that paralanguage deficits in children with ACC would be less apparent relative to…

Agraphia of the left hand with dysfunction of the left superior parietal region without callosal lesions.

PubMed

Kinno, Ryuta; Ohashi, Hideaki; Mori, Yukiko; Shiromaru, Azusa; Ono, Kenjiro

2018-03-01

A 28-year-old right-handed man noticed weakness in his legs, three days after an ephedrine overdose. Initial brain magnetic resonance imaging showed lesions in the parietal regions bilaterally. Computed tomography angiography showed segmental and multifocal vasoconstriction of the cerebral arteries. After treatment, clinical and radiological findings resolved, suggesting the patient had reversible cerebral vasoconstriction syndrome with posterior reversible encephalopathy syndrome. However, he had residual agraphia of the left hand. Language testing revealed no difficulties in oral expression, auditory comprehension, understanding of written language, or writing with the right hand. I-123 iodoamphetamine single-photon emission computed tomography showed residual dysfunction in the left superior parietal lobule. There were no apparent signs of other disconnection syndromes or neuroimaging abnormalities in the corpus callosum. We diagnosed left-hand agraphia due to left parietal dysfunction. Our case suggests that left superior parietal dysfunction without callosal lesions is a possible cause of left-hand agraphia. Neural mechanisms for writing with the right or left hand may be separable at the cortical level.

Callosal tracts and patterns of hemispheric dominance: a combined fMRI and DTI study.

PubMed

Häberling, Isabelle S; Badzakova-Trajkov, Gjurgjica; Corballis, Michael C

2011-01-15

Left-hemispheric dominance for language and right-hemispheric dominance for spatial processing are distinctive characteristics of the human brain. However, variations of these hemispheric asymmetries have been observed, with a minority showing crowding of both functions to the same hemisphere or even a mirror reversal of the typical lateralization pattern. Here, we used diffusion tensor imaging and functional magnetic imaging to investigate the role of the corpus callosum in participants with atypical hemispheric dominance. The corpus callosum was segmented according to the projection site of the underlying fibre tracts. Analyses of the microstructure of the identified callosal segments revealed that atypical hemispheric dominance for language was associated with high anisotropic diffusion through the corpus callosum as a whole. This effect was most evident in participants with crowding of both functions to the right. The enhanced anisotropic diffusion in atypical hemispheric dominance implies that in these individuals the two hemispheres are more heavily interconnected. Copyright © 2010 Elsevier Inc. All rights reserved.

Hemispheric specialization in spontaneous gesticulation in a patient with callosal disconnection.

PubMed

Lausberg, H; Davis, M; Rothenhäusler, A

2000-01-01

This is an investigation of spontaneous gesticulation in a left-handed patient with a callosal disconnection syndrome due to infarction of the total length of the corpus callosum. After callosal infarction, the patient gesticulated predominantly unilaterally with the left hand despite left apraxia. Bilateral gesticulation occurred later on and was presumably achieved by an increase in ipsilateral proximal control. Movement analysis further indicated that the two hemispheres are specialized for certain gesture types. Gestures with emotional connotation and batons (emphasizing prosody) were generated predominantly in the right hemisphere whereas physiographics which picture the linguistic content concretely and deictics (pointing) were of left-hemispheric origin.

Sex differences in associations between spatial ability and corpus callosum morphology.

PubMed

Kurth, Florian; Spencer, Debra; Hines, Melissa; Luders, Eileen

2018-05-10

Rotating mental representations of objects is accompanied by widespread bilateral brain activations. Thus, interhemispheric communication channels may play a relevant part when engaging in mental rotation tasks. Indeed, links between mental rotation and dimensions of the corpus callosum-the brain's main commissure system-have been reported. However, existing findings are sparse and inconsistent across studies. Here we set out to further characterize the nature of any such links, including their exact location across the corpus callosum. For this purpose, we applied an advanced image analysis approach assessing callosal thickness at 100 equidistant points in a sample of 38 healthy adults (19 men, 19 women), aged between 22 and 45 years. We detected a sex interaction, with significant structure-performance relationships in women, but not in men. Specifically, better mental rotation performance was linked to a thicker female corpus callosum within regions of the callosal splenium, posterior midbody, and anterior third. These findings may suggest sex differences in problem solving strategies where in women, more than in men, stronger interhemispheric connectivity-especially between occipitoparietal, frontal, and prefrontal regions-is associated with improved task performance. © 2018 Wiley Periodicals, Inc. © 2018 Wiley Periodicals, Inc.

A Mammalian Conserved Element Derived from SINE Displays Enhancer Properties Recapitulating Satb2 Expression in Early-Born Callosal Projection Neurons

PubMed Central

Nakanishi, Akiko; Sasaki, Takeshi; Yan, Kuo; Tarabykin, Victor; Vigier, Lisa; Sumiyama, Kenta; Hirakawa, Mika; Nishihara, Hidenori; Pierani, Alessandra; Okada, Norihiro

2011-01-01

Short interspersed repetitive elements (SINEs) are highly repeated sequences that account for a significant proportion of many eukaryotic genomes and are usually considered “junk DNA”. However, we previously discovered that many AmnSINE1 loci are evolutionarily conserved across mammalian genomes, suggesting that they may have acquired significant functions involved in controlling mammalian-specific traits. Notably, we identified the AS021 SINE locus, located 390 kbp upstream of Satb2. Using transgenic mice, we showed that this SINE displays specific enhancer activity in the developing cerebral cortex. The transcription factor Satb2 is expressed by cortical neurons extending axons through the corpus callosum and is a determinant of callosal versus subcortical projection. Mouse mutants reveal a crucial function for Sabt2 in corpus callosum formation. In this study, we compared the enhancer activity of the AS021 locus with Satb2 expression during telencephalic development in the mouse. First, we showed that the AS021 enhancer is specifically activated in early-born Satb2+ neurons. Second, we demonstrated that the activity of the AS021 enhancer recapitulates the expression of Satb2 at later embryonic and postnatal stages in deep-layer but not superficial-layer neurons, suggesting the possibility that the expression of Satb2 in these two subpopulations of cortical neurons is under genetically distinct transcriptional control. Third, we showed that the AS021 enhancer is activated in neurons projecting through the corpus callosum, as described for Satb2+ neurons. Notably, AS021 drives specific expression in axons crossing through the ventral (TAG1−/NPY+) portion of the corpus callosum, confirming that it is active in a subpopulation of callosal neurons. These data suggest that exaptation of the AS021 SINE locus might be involved in enhancement of Satb2 expression, leading to the establishment of interhemispheric communication via the corpus callosum, a eutherian-specific brain structure. PMID:22174821

Structural and Perfusion Abnormalities of Brain on MRI and Technetium-99m-ECD SPECT in Children With Cerebral Palsy: A Comparative Study.

PubMed

Rana, Kamer Singh; Narwal, Varun; Chauhan, Lokesh; Singh, Giriraj; Sharma, Monica; Chauhan, Suneel

2016-04-01

Cerebral palsy has traditionally been associated with hypoxic ischemic brain damage. This study was undertaken to demonstrate structural and perfusion brain abnormalities. Fifty-six children diagnosed clinically as having cerebral palsy were studied between 1 to 14 years of age and were subjected to 3 Tesla magnetic resonance imaging (MRI). Brain and Technetium-99m-ECD brain single-photon emission computed tomography (SPECT) scan. Male to female ratio was 1.8:1 with a mean age of 4.16 ± 2.274 years. Spastic cerebral palsy was the most common type, observed in 91%. Birth asphyxia was the most common etiology (69.6%). White matter changes (73.2%) such as periventricular leukomalacia and corpus callosal thinning were the most common findings on MRI. On SPECT all cases except one revealed perfusion impairments in different regions of brain. MRI is more sensitive in detecting white matter changes, whereas SPECT is better in detecting cortical and subcortical gray matter abnormalities of perfusion. © The Author(s) 2015.

The right inhibition? Callosal correlates of hand performance in healthy children and adolescents callosal correlates of hand performance.

PubMed

Kurth, Florian; Mayer, Emeran A; Toga, Arthur W; Thompson, Paul M; Luders, Eileen

2013-09-01

Numerous studies suggest that interhemispheric inhibition-relayed via the corpus callosum-plays an important role in unilateral hand motions. Interestingly, transcallosal inhibition appears to be indicative of a strong laterality effect, where generally the dominant hemisphere exerts inhibition on the nondominant one. These effects have been largely identified through functional studies in adult populations, but links between motor performance and callosal structure (especially during sensitive periods of neurodevelopment) remain largely unknown. We therefore investigated correlations between Purdue Pegboard performance (a test of motor function) and local callosal thickness in 170 right-handed children and adolescents (mean age: 11.5 ± 3.4 years; range, 6-17 years). Better task performance with the right (dominant) hand was associated with greater callosal thickness in isthmus and posterior midbody. Task performance using both hands yielded smaller and less significant correlations in the same regions, while task performance using the left (nondominant) hand showed no significant correlations with callosal thickness. There were no significant interactions with age and sex. These links between motor performance and callosal structure may constitute the neural correlate of interhemispheric inhibition, which is thought to be necessary for fast and complex unilateral motions and to be biased towards the dominant hand. Copyright © 2012 Wiley Periodicals, Inc., a Wiley company.

Callosal responses in a retrosplenial column.

PubMed

Sempere-Ferràndez, Alejandro; Andrés-Bayón, Belén; Geijo-Barrientos, Emilio

2018-04-01

The axons forming the corpus callosum sustain the interhemispheric communication across homotopic cortical areas. We have studied how neurons throughout the columnar extension of the retrosplenial cortex integrate the contralateral input from callosal projecting neurons in cortical slices. Our results show that pyramidal neurons in layers 2/3 and the large, thick-tufted pyramidal neurons in layer 5B showed larger excitatory callosal responses than layer 5A and layer 5B thin-tufted pyramidal neurons, while layer 6 remained silent to this input. Feed-forward inhibitory currents generated by fast spiking, parvalbumin expressing  interneurons recruited by callosal axons mimicked the response size distribution of excitatory responses across pyramidal subtypes, being larger in those of superficial layers and in the layer 5B thick-tufted pyramidal cells. Overall, the combination of the excitatory and inhibitory currents evoked by callosal input had a strong and opposed effect in different layers of the cortex; while layer 2/3 pyramidal neurons were powerfully inhibited, the thick-tufted but not thin-tufted pyramidal neurons in layer 5 were strongly recruited. We believe that these results will help to understand the functional role of callosal connections in physiology and disease.

Longitudinal magnetic resonance imaging study shows progressive pyramidal and callosal damage in Friedreich's ataxia.

PubMed

Rezende, Thiago J R; Silva, Cynthia B; Yassuda, Clarissa L; Campos, Brunno M; D'Abreu, Anelyssa; Cendes, Fernando; Lopes-Cendes, Iscia; França, Marcondes C

2016-01-01

Spinal cord and peripheral nerves are classically known to be damaged in Friedreich's ataxia, but the extent of cerebral involvement in the disease and its progression over time are not yet characterized. The aim of this study was to evaluate longitudinally cerebral damage in Friedreich's ataxia. We enrolled 31 patients and 40 controls, which were evaluated at baseline and after 1 and 2 years. To assess gray matter, we employed voxel-based morphometry and cortical thickness measurements. White matter was evaluated using diffusion tensor imaging. Statistical analyses were both cross-sectional and longitudinal (corrected for multiple comparisons). Group comparison between patients and controls revealed widespread macrostructural differences at baseline: gray matter atrophy in the dentate nuclei, brainstem, and precentral gyri; and white matter atrophy in the cerebellum and superior cerebellar peduncles, brainstem, and periventricular areas. We did not identify any longitudinal volumetric change over time. There were extensive microstructural alterations, including superior cerebellar peduncles, corpus callosum, and pyramidal tracts. Longitudinal analyses identified progressive microstructural abnormalities at the corpus callosum, pyramidal tracts, and superior cerebellar peduncles after 1 year of follow-up. Patients with Friedreich's ataxia present more widespread gray and white matter damage than previously reported, including not only infratentorial areas, but also supratentorial structures. Furthermore, patients with Friedreich's ataxia have progressive microstructural abnormalities amenable to detection in a short-term follow-up. © 2015 International Parkinson and Movement Disorder Society.

Quantitative analysis of structural variations in corpus callosum in adults with multiple system atrophy (MSA)

NASA Astrophysics Data System (ADS)

Bhattacharya, Debanjali; Sinha, Neelam; Saini, Jitender

2017-03-01

Multiple system atrophy (MSA) is a rare, non-curable, progressive neurodegenerative disorder that affects nervous system and movement, poses a considerable diagnostic challenge to medical researchers. Corpus callosum (CC) being the largest white matter structure in brain, enabling inter-hemispheric communication, quantification of callosal atrophy may provide vital information at the earliest possible stages. The main objective is to identify the differences in CC structure for this disease, based on quantitative analysis on the pattern of callosal atrophy. We report results of quantification of structural changes in regional anatomical thickness, area and length of CC between patient-groups with MSA with respect to healthy controls. The method utilizes isolating and parcellating the mid-sagittal CC into 100 segments along the length - measuring the width of each segment. It also measures areas within geometrically defined five callosal compartments of the well-known Witelson, and Hofer-Frahma schemes. For quantification, statistical tests are performed on these different callosal measurements. From the statistical analysis, it is concluded that compared to healthy controls, width is reduced drastically throughout CC for MSA group and as well as changes in area and length are also significant for MSA. The study is further extended to check if any significant difference in thickness is found between the two variations of MSA, Parkinsonian MSA and Cerebellar MSA group, using the same methodology. However area and length of this two sub-MSA group, no substantial difference is obtained. The study is performed on twenty subjects for each control and MSA group, who had T1-weighted MRI.

Involuntary masturbation and hemiballismus after bilateral anterior cerebral artery infarction.

PubMed

Bejot, Yannick; Caillier, Marie; Osseby, Guy-Victor; Didi, Roy; Ben Salem, Douraied; Moreau, Thibault; Giroud, Maurice

2008-02-01

Ischemia of the areas supplied by the anterior cerebral artery is relatively uncommon. In addition, combined hemiballismus and masturbation have rarely been reported in patients with cerebrovascular disease. We describe herein a 62-year-old right-handed man simultaneously exhibiting right side hemiballismus and involuntary masturbation with the left hand after bilateral infarction of the anterior cerebral artery territory. Right side hemiballismus was related to the disruption of afferent fibers from the left frontal lobe to the left subthalamic nucleus. Involuntary masturbation using the left hand was exclusively linked to a callosal type of alien hand syndrome secondary to infarction of the right side of the anterior corpus callosum. After 2 weeks, these abnormal behaviours were completely extinguished. This report stresses the wide diversity of clinical manifestations observed after infarction of the anterior cerebral artery territory.

Right unilateral agraphia following callosal infarction in a left-hander.

PubMed

Tei, H; Soma, Y; Maruyama, S

1994-01-01

A left-handed Japanese man is reported who presented right-hand agraphia and tactile anomia following callosal infarction. Magnetic resonance imaging revealed an ischemic lesion extending from the posterior half of the trunk to the splenium of the corpus callosum. In his right handwriting, the 'Kana' (phonogram) was more severely impaired than the 'Kanji' (ideogram), and the most frequent typewriting error was morphological followed by neographism. His visuoconstructional ability was also more impaired in the right hand than in the left. Right-hand agraphia in our case is readily explained by the right hemisphere dominance both for language and visuoconstructional ability.

Callosal disconnection syndrome in a left-handed patient due to infarction of the total length of the corpus callosum.

PubMed

Lausberg, H; Göttert, R; Münssinger, U; Boegner, F; Marx, P

1999-03-01

We report on a left-handed patient with an ischemic infarction affecting exclusively the total length of the corpus callosum. This lesion clinically correlated with an almost complete callosal disconnection syndrome as described in callosotomy subjects, including unilateral verbal anosmia, hemialexia, unilateral ideomotor apraxia, unilateral agraphia, unilateral tactile anomia, unilateral constructional apraxia, lack of somesthetic transfer and dissociative phenomena. Despite the patient's left-handedness, his pattern of deficits was similar to the disconnection syndrome found in right-handers. Our report focusses on motor dominance and praxis. We followed-up the improvement in left apraxia and investigated the ability to initiate and learn a new visuo-motor skill. The results permit two tentative assumptions: (1) that the improvement in left apraxia was due to a compensatory increase in ipsilateral proximal muscle control, and (2) that motor dominance, i.e. the competence to initiate and learn a new movement pattern, was hemispherically dissociable from manual dominance in the sense of praxis control.

Detecting functional magnetic resonance imaging activation in white matter: Interhemispheric transfer across the corpus callosum

PubMed Central

Mazerolle, Erin L; D'Arcy, Ryan CN; Beyea, Steven D

2008-01-01

Background It is generally believed that activation in functional magnetic resonance imaging (fMRI) is restricted to gray matter. Despite this, a number of studies have reported white matter activation, particularly when the corpus callosum is targeted using interhemispheric transfer tasks. These findings suggest that fMRI signals may not be neatly confined to gray matter tissue. In the current experiment, 4 T fMRI was employed to evaluate whether it is possible to detect white matter activation. We used an interhemispheric transfer task modelled after neurological studies of callosal disconnection. It was hypothesized that white matter activation could be detected using fMRI. Results Both group and individual data were considered. At liberal statistical thresholds (p < 0.005, uncorrected), group level activation was detected in the isthmus of the corpus callosum. This region connects the superior parietal cortices, which have been implicated previously in interhemispheric transfer. At the individual level, five of the 24 subjects (21%) had activation clusters that were located primarily within the corpus callosum. Consistent with the group results, the clusters of all five subjects were located in posterior callosal regions. The signal time courses for these clusters were comparable to those observed for task related gray matter activation. Conclusion The findings support the idea that, despite the inherent challenges, fMRI activation can be detected in the corpus callosum at the individual level. Future work is needed to determine whether the detection of this activation can be improved by utilizing higher spatial resolution, optimizing acquisition parameters, and analyzing the data with tissue specific models of the hemodynamic response. The ability to detect white matter fMRI activation expands the scope of basic and clinical brain mapping research, and provides a new approach for understanding brain connectivity. PMID:18789154

Gross morphology and morphometric sequelae in the hippocampus, fornix, and corpus callosum of patients with severe non-missile traumatic brain injury without macroscopically detectable lesions: a T1 weighted MRI study

PubMed Central

Tomaiuolo, F; Carlesimo, G; Di, P; Petrides, M; Fera, F; Bonanni, R; Formisano, R; Pasqualetti, P; Caltagirone, C

2004-01-01

Objective: The gross morphology and morphometry of the hippocampus, fornix, and corpus callosum in patients with severe non-missile traumatic brain injury (nmTBI) without obvious neuroradiological lesions was examined and the volumes of these structures were correlated with performance on memory tests. In addition, the predictability of the length of coma from the selected anatomical volumes was examined. Method: High spatial resolution T1 weighted MRI scans of the brain (1 mm3) and neuropsychological evaluations with standardised tests were performed at least 3 months after trauma in 19 patients. Results: In comparison with control subjects matched in terms of gender and age, volume reduction in the hippocampus, fornix, and corpus callosum of the nmTBI patients was quantitatively significant. The length of coma correlated with the volume reduction in the corpus callosum. Immediate free recall of word lists correlated with the volume of the fornix and the corpus callosum. Delayed recall of word lists and immediate recall of the Rey figure both correlated with the volume of the fornix. Delayed recall of the Rey figure correlated with the volume of the fornix and the right hippocampus. Conclusion: These findings demonstrate that in severe nmTBI without obvious neuroradiological lesions there is a clear hippocampal, fornix, and callosal volume reduction. The length of coma predicts the callosal volume reduction, which could be considered a marker of the severity of axonal loss. A few memory test scores correlated with the volumes of the selected anatomical structures. This relationship with memory performance may reflect the diffuse nature of the damage, leading to the disruption of neural circuits at multiple levels and the progressive neural degeneration occurring in TBI. PMID:15314123

Corpus callosum demyelination associated with acquired stuttering.

PubMed

Decker, Barbara McElwee; Guitar, Barry; Solomon, Andrew

2018-04-21

Compared with developmental stuttering, adult onset acquired stuttering is rare. However, several case reports describe acquired stuttering and an association with callosal pathology. Interestingly, these cases share a neuroanatomical localisation also demonstrated in developmental stuttering. We present a case of adult onset acquired stuttering associated with inflammatory demyelination within the corpus callosum. This patient's disfluency improved after the initiation of immunomodulatory therapy. © BMJ Publishing Group Ltd (unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Deposition of callose in young ovules of two Taraxacum species varying in the mode of reproduction.

PubMed

Musiał, Krystyna; Kościńska-Pająk, Maria; Antolec, Renata; Joachimiak, Andrzej J

2015-01-01

Although callose occurs during megasporogenesis in most flowering plants, the knowledge about its general function and the mechanisms by which the callose layer is formed in particular places is still not sufficient. The results of previous studies suggest a total lack of callose in the ovules of diplosporous plants in which meiosis is omitted or disturbed. This report is the first documentation of callose events in dandelions ovules. We demonstrated the pattern of callose deposition during the formation of megaspores through diplospory of Taraxacum type and during normal meiotic megasporogenesis in apomictic triploid Taraxacum atricapillum and amphimictic diploid Taraxacum linearisquameum. We found the presence of callose in the megasporocyte wall of both diplosporous and sexual dandelions. However, in a diplosporous dandelion, callose predominated at the micropylar pole of megaspore mother cell (MMC) which may be correlated with abnormal asynaptic meiosis and may indicate diplospory of the Taraxacum type. After meiotic division, callose is mainly deposited in the walls between megaspores in tetrads and in diplodyads. In subsequent stages, callose gradually disappears around the chalazal functional megaspore. However, some variations in the pattern of callose deposition within tetrad may reflect variable positioning of the functional megaspore (FM) observed in the ovules of T. linearisquameum.

Cytotoxic Lesions of the Corpus Callosum That Show Restricted Diffusion: Mechanisms, Causes, and Manifestations.

PubMed

Starkey, Jay; Kobayashi, Nobuo; Numaguchi, Yuji; Moritani, Toshio

2017-01-01

Cytotoxic lesions of the corpus callosum (CLOCCs) are secondary lesions associated with various entities. CLOCCs have been found in association with drug therapy, malignancy, infection, subarachnoid hemorrhage, metabolic disorders, trauma, and other entities. In all of these conditions, cell-cytokine interactions lead to markedly increased levels of cytokines and extracellular glutamate. Ultimately, this cascade can lead to dysfunction of the callosal neurons and microglia. Cytotoxic edema develops as water becomes trapped in these cells. On diffusion-weighted magnetic resonance (MR) images, CLOCCs manifest as areas of low diffusion. CLOCCs lack enhancement on contrast material-enhanced images, tend to be midline, and are relatively symmetric. The involvement of the corpus callosum typically shows one of three patterns: (a) a small round or oval lesion located in the center of the splenium, (b) a lesion centered in the splenium but extending through the callosal fibers laterally into the adjacent white matter, or (c) a lesion centered posteriorly but extending into the anterior corpus callosum. CLOCCs are frequently but not invariably reversible. Their pathologic mechanisms are discussed, the typical MR imaging findings are described, and typical cases of CLOCCs are presented. Although CLOCCs are nonspecific with regard to the underlying cause, additional imaging findings and the clinical findings can aid in making a specific diagnosis. Radiologists should be familiar with the imaging appearance of CLOCCs to avoid a misdiagnosis of ischemia. When CLOCCs are found, the underlying cause of the lesion should be sought and addressed. © RSNA, 2017 An earlier incorrect version of this article appeared online. This article was corrected on February 13, 2017.

Cortical brain connectivity evaluated by graph theory in dementia: a correlation study between functional and structural data.

PubMed

Vecchio, Fabrizio; Miraglia, Francesca; Curcio, Giuseppe; Altavilla, Riccardo; Scrascia, Federica; Giambattistelli, Federica; Quattrocchi, Carlo Cosimo; Bramanti, Placido; Vernieri, Fabrizio; Rossini, Paolo Maria

2015-01-01

A relatively new approach to brain function in neuroscience is the "functional connectivity", namely the synchrony in time of activity in anatomically-distinct but functionally-collaborating brain regions. On the other hand, diffusion tensor imaging (DTI) is a recently developed magnetic resonance imaging (MRI)-based technique with the capability to detect brain structural connection with fractional anisotropy (FA) identification. FA decrease has been observed in the corpus callosum of subjects with Alzheimer's disease (AD) and mild cognitive impairment (MCI, an AD prodromal stage). Corpus callosum splenium DTI abnormalities are thought to be associated with functional disconnections among cortical areas. This study aimed to investigate possible correlations between structural damage, measured by MRI-DTI, and functional abnormalities of brain integration, measured by characteristic path length detected in resting state EEG source activity (40 participants: 9 healthy controls, 10 MCI, 10 mild AD, 11 moderate AD). For each subject, undirected and weighted brain network was built to evaluate graph core measures. eLORETA lagged linear connectivity values were used as weight of the edges of the network. Results showed that callosal FA reduction is associated to a loss of brain interhemispheric functional connectivity characterized by increased delta and decreased alpha path length. These findings suggest that "global" (average network shortest path length representing an index of how efficient is the information transfer between two parts of the network) functional measure can reflect the reduction of fiber connecting the two hemispheres as revealed by DTI analysis and also anticipate in time this structural loss.

White Matter Compromise of Callosal and Subcortical Fiber Tracts in Children with Autism Spectrum Disorder: A Diffusion Tensor Imaging Study

ERIC Educational Resources Information Center

Shukla, Dinesh K.; Keehn, Brandon; Lincoln, Alan J.; Muller, Ralph-Axel

2010-01-01

Objective: Autism spectrum disorder (ASD) is increasingly viewed as a disorder of functional networks, highlighting the importance of investigating white matter and interregional connectivity. We used diffusion tensor imaging (DTI) to examine white matter integrity for the whole brain and for corpus callosum, internal capsule, and middle…

The link between callosal thickness and intelligence in healthy children and adolescents.

PubMed

Luders, Eileen; Thompson, Paul M; Narr, Katherine L; Zamanyan, Alen; Chou, Yi-Yu; Gutman, Boris; Dinov, Ivo D; Toga, Arthur W

2011-02-01

The link between brain structure and intelligence is a well-investigated topic, but existing analyses have mainly focused on adult samples. Studies in healthy children and adolescents are rare, and normative data specifically addressing the association between corpus callosum morphology and intellectual abilities are quite limited. To advance this field of research, we mapped the correlations between standardized intelligence measures and callosal thickness based on high-resolution magnetic resonance imaging (MRI) data. Our large and well-matched sample included 200 normally developing subjects (100 males, 100 females) ranging from 6 to 17 years of age. Although the strongest correlations were negative and confined to the splenium, the strength and the direction of intelligence-callosal thickness associations varied considerably. While significant correlations in females were mainly positive, significant correlations in males were exclusively negative. However, only the negative correlations in the overall sample (i.e., males and females combined) remained significant when controlling for multiple comparisons. The observed negative correlations between callosal thickness and intelligence in children and adolescents contrast with the positive correlations typically reported in adult samples. However, negative correlations are in line with reports from other pediatric studies relating cognitive measures to other brain attributes such as cortical thickness, gray matter volume, and gray matter density. Altogether, these findings suggest that relationships between callosal morphology and cognition are highly dynamic during brain maturation. Sex effects on links between callosal thickness and intelligence during childhood and adolescence are present but appear rather weak in general. Copyright © 2010 Elsevier Inc. All rights reserved.

The link between callosal thickness and intelligence in healthy children and adolescents

PubMed Central

Luders, Eileen; Thompson, Paul M.; Narr, Katherine L.; Zamanyan, Alen; Chou, Yi-Yu; Gutman, Boris; Dinov, Ivo D.; Toga, Arthur W.

2010-01-01

The link between brain structure and intelligence is a well-investigated topic, but existing analyses have mainly focused on adult samples. Studies in healthy children and adolescents are rare, and normative data specifically addressing the association between corpus callosum morphology and intellectual abilities is quite limited. To advance this field of research, we mapped the correlations between standardized intelligence measures and callosal thickness based on high-resolution magnetic resonance imaging (MRI) data. Our large and well-matched sample included 200 normally developing subjects (100 males, 100 females) ranging from 6 to 17 years of age. Although the strongest correlations were negative and confined to the splenium, the strength and the direction of intelligence-callosal thickness associations varied considerably with respect to age and sex. While significant correlations in females were mainly positive, significant correlations in males were exclusively negative. However, only the negative correlations in the overall sample (i.e., males and females combined) remained significant when controlling for multiple comparisons. The observed negative correlations between callosal thickness and intelligence in children and adolescents contrast with the positive correlations typically reported in adult samples. However, negative correlations are in line with reports from other pediatric studies relating cognitive measures to other brain attributes such as cortical thickness, gray matter volume, and gray matter density. Altogether, these findings suggest that relationships between callosal morphology and cognition are highly dynamic during brain maturation. Sex effects on links between callosal thickness and intelligence during childhood and adolescence are present but appear rather weak in general. PMID:20932920

Local-global interference is modulated by age, sex and anterior corpus callosum size

PubMed Central

Müller-Oehring, Eva M.; Schulte, Tilman; Raassi, Carla; Pfefferbaum, Adolf; Sullivan, Edith V.

2007-01-01

To identify attentional and neural mechanisms affecting global and local feature extraction, we devised a global-local hierarchical letter paradigm to test the hypothesis that aging reduces functional cerebral lateralization through corpus callosum (CC) degradation. Participants (37 men and women, 26–79 years) performed a task requiring global, local, or global+local attention and underwent structural MRI for CC measurement. Although reaction time (RT) slowed with age, all participants had faster RTs to local than global targets. This local precedence effect together with greater interference from incongruent local information and greater response conflict from local targets each correlated with older age and smaller callosal genu (anterior) areas. These findings support the hypothesis that the CC mediates lateralized local-global processes by inhibition of task-irrelevant information under selective attention conditions. Further, with advancing age smaller genu size leads to less robust inhibition, thereby reducing cerebral lateralization and permitting interference to influence processing. Sex was an additional modifier of interference, in that callosum-interference relationships were evident in women but not in men. Regardless of age, smaller splenium (posterior) areas correlated with less response facilitation from repetition priming of global targets in men, but with greater response facilitation from repetition priming of local targets in women. Our data indicate the following dissociation: Anterior callosal structure was associated with inhibitory processes (i.e., interference from incongruency and response conflict), which are vulnerable to the effects of age and sex, whereas posterior callosal structure was associated with facilitation processes from repetition priming dependent on sex and independent of age. PMID:17335783

Local-global interference is modulated by age, sex and anterior corpus callosum size.

PubMed

Müller-Oehring, Eva M; Schulte, Tilman; Raassi, Carla; Pfefferbaum, Adolf; Sullivan, Edith V

2007-04-20

To identify attentional and neural mechanisms affecting global and local feature extraction, we devised a global-local hierarchical letter paradigm to test the hypothesis that aging reduces functional cerebral lateralization through corpus callosum (CC) degradation. Participants (37 men and women, 26-79 years) performed a task requiring global, local, or global+local attention and underwent structural MRI for CC measurement. Although reaction time (RT) slowed with age, all participants had faster RTs to local than global targets. This local precedence effect together with greater interference from incongruent local information and greater response conflict from local targets each correlated with older age and smaller callosal genu (anterior) areas. These findings support the hypothesis that the CC mediates lateralized local-global processes by inhibition of task-irrelevant information under selective attention conditions. Further, with advancing age smaller genu size leads to less robust inhibition, thereby reducing cerebral lateralization and permitting interference to influence processing. Sex was an additional modifier of interference, in that callosum-interference relationships were evident in women but not in men. Regardless of age, smaller splenium (posterior) areas correlated with less response facilitation from repetition priming of global targets in men, but with greater response facilitation from repetition priming of local targets in women. Our data indicate the following dissociation: anterior callosal structure was associated with inhibitory processes (i.e., interference from incongruency and response conflict), which are vulnerable to the effects of age and sex, whereas posterior callosal structure was associated with facilitation processes from repetition priming dependent on sex and independent of age.

Altered callose deposition during embryo sac formation of multi-pistil mutant (mp1) in Medicago sativa.

PubMed

Zhou, H C; Jin, L; Li, J; Wang, X J

2016-06-03

Whether callose deposition is the cause or result of ovule sterility in Medicago sativa remains controversial, because it is unclear when and where changes in callose deposition and dissolution occur during fertile and sterile embryo sac formation. Here, alfalfa spontaneous multi-pistil mutant (mp1) and wild-type plants were used to compare the dynamics of callose deposition during embryo sac formation using microscopy. The results showed that both mutant and wild-type plants experienced megasporogenesis and megagametogenesis, and there was no significant difference during megasporogenesis. In contrast to the wild-type plants, in which the mature embryo sac was observed after three continuous cycles of mitosis, functional megaspores of mutant plants developed abnormally after the second round of mitosis, leading to degeneration of synergid, central, and antipodal cells. Callose deposition in both mutant and wild-type plants was first observed in the walls of megasporocytes, and then in the megaspore tetrad walls. After meiosis, the callose wall began to degrade as the functional megaspore underwent mitosis, and almost no callose was observed in the mature embryo sac in wild-type plants. However, callose deposition was observed in mp1 plants around the synergid, and increased with the development of the embryo sac, and was mainly deposited at the micropylar end. Our results indicate that synergid, central, and antipodal cells, which are surrounded by callose, may degrade owing to lack of nutrition. Callose accumulation around the synergid and at the micropylar end may hinder signals required for the pollen tube to enter the embryo sac, leading to abortion.

Pathology of callosal damage in ALS: An ex-vivo, 7 T diffusion tensor MRI study.

PubMed

Cardenas, Agustin M; Sarlls, Joelle E; Kwan, Justin Y; Bageac, Devin; Gala, Zachary S; Danielian, Laura E; Ray-Chaudhury, Abhik; Wang, Hao-Wei; Miller, Karla L; Foxley, Sean; Jbabdi, Saad; Welsh, Robert C; Floeter, Mary Kay

2017-01-01

The goal of this study was to better understand the changes in tissue microstructure that underlie white matter diffusion changes in ALS patients. Diffusion tensor imaging was carried out in postmortem brains of 4 ALS patients and two subjects without neurological disease on a 7 T MRI scanner using steady-state free precession sequences. Fractional anisotropy (FA) was measured in the genu, body, and splenium of the corpus callosum in formalin-fixed hemispheres. FA of the body and genu was expressed as ratio to FA of the splenium, a region unaffected in ALS. After imaging, tissue sections of the same segments of the callosum were stained for markers of different tissue components. Coded image fields were rated for pathological changes by blinded raters. The FA body/FA splenium ratio was reduced in ALS patients compared to controls. Patchy areas of myelin pallor and cells immunostained for CD68, a microglial-macrophage marker, were only observed in the body of the callosum of ALS patients. Blinded ratings showed increased CD68 + microglial cells in the body of the corpus callosum in ALS patients, especially those with C9orf72 mutations, and increased reactive astrocytes throughout the callosum. Reduced FA of the corpus callosum in ALS results from complex changes in tissue microstructure. Callosal segments with reduced FA had large numbers of microglia-macrophages in addition to loss of myelinated axons and astrogliosis. Microglial inflammation contributed to reduced FA in ALS, and may contribute to a pro-inflammatory state, but further work is needed to determine their role.

Appropriate Bmp7 levels are required for the differentiation of midline guidepost cells involved in corpus callosum formation.

PubMed

Sánchez-Camacho, Cristina; Ortega, Juan Alberto; Ocaña, Inmaculada; Alcántara, Soledad; Bovolenta, Paola

2011-05-01

Guidepost cells are essential structures for the establishment of major axonal tracts. How these structures are specified and acquire their axon guidance properties is still poorly understood. Here, we show that in mouse embryos appropriate levels of Bone Morphogenetic Protein 7 (Bmp7), a member of the TGF-β superfamily of secreted proteins, are required for the correct development of the glial wedge, the indusium griseum, and the subcallosal sling, three groups of cells that act as guidepost cells for growing callosal axons. Bmp7 is expressed in the region occupied by these structures and its genetic inactivation in mouse embryos caused a marked reduction and disorganization of these cell populations. On the contrary, infusion of recombinant Bmp7 in the developing forebrain induced their premature differentiation. In both cases, changes were associated with the disruption of callosal axon growth and, in most animals fibers did not cross the midline forming typical Probst bundles. Addition of Bmp7 to cortical explants did not modify the extent of their outgrowth nor their directionality, when explants were exposed to a focalized source of the protein. Together, these results indicate that Bmp7 is indirectly required for corpus callosum formation by controlling the timely differentiation of its guidepost cells. Copyright © 2010 Wiley Periodicals, Inc.

Neonatal White Matter Abnormalities an Important Predictor of Neurocognitive Outcome for Very Preterm Children

PubMed Central

Woodward, Lianne J.; Clark, Caron A. C.; Bora, Samudragupta; Inder, Terrie E.

2012-01-01

Background Cerebral white matter abnormalities on term MRI are a strong predictor of motor disability in children born very preterm. However, their contribution to cognitive impairment is less certain. Objective Examine relationships between the presence and severity of cerebral white matter abnormalities on neonatal MRI and a range of neurocognitive outcomes assessed at ages 4 and 6 years. Design/Methods The study sample consisted of a regionally representative cohort of 104 very preterm (≤32 weeks gestation) infants born from 1998–2000 and a comparison group of 107 full-term infants. At term equivalent, all preterm infants underwent a structural MRI scan that was analyzed qualitatively for the presence and severity of cerebral white matter abnormalities, including cysts, signal abnormalities, loss of white matter volume, ventriculomegaly, and corpus callosal thinning/myelination. At corrected ages 4 and 6 years, all children underwent a comprehensive neurodevelopmental assessment that included measures of general intellectual ability, language development, and executive functioning. Results At 4 and 6 years, very preterm children without cerebral white matter abnormalities showed no apparent neurocognitive impairments relative to their full-term peers on any of the domain specific measures of intelligence, language, and executive functioning. In contrast, children born very preterm with mild and moderate-to-severe white matter abnormalities were characterized by performance impairments across all measures and time points, with more severe cerebral abnormalities being associated with increased risks of cognitive impairment. These associations persisted after adjustment for gender, neonatal medical risk factors, and family social risk. Conclusions Findings highlight the importance of cerebral white matter connectivity for later intact cognitive functioning amongst children born very preterm. Preterm born children without cerebral white matter abnormalities on their term MRI appear to be spared many of the cognitive impairments commonly associated with preterm birth. Further follow-up will be important to assess whether this finding persists into the school years. PMID:23284800

Concomitant fractional anisotropy and volumetric abnormalities in temporal lobe epilepsy: cross-sectional evidence for progressive neurologic injury.

PubMed

Keller, Simon S; Schoene-Bake, Jan-Christoph; Gerdes, Jan S; Weber, Bernd; Deppe, Michael

2012-01-01

In patients with temporal lobe epilepsy and associated hippocampal sclerosis (TLEhs) there are brain abnormalities extending beyond the presumed epileptogenic zone as revealed separately in conventional magnetic resonance imaging (MRI) and MR diffusion tensor imaging (DTI) studies. However, little is known about the relation between macroscopic atrophy (revealed by volumetric MRI) and microstructural degeneration (inferred by DTI). For 62 patients with unilateral TLEhs and 68 healthy controls, we determined volumes and mean fractional anisotropy (FA) of ipsilateral and contralateral brain structures from T1-weighted and DTI data, respectively. We report significant volume atrophy and FA alterations of temporal lobe, subcortical and callosal regions, which were more diffuse and bilateral in patients with left TLEhs relative to right TLEhs. We observed significant relationships between volume loss and mean FA, particularly of the thalamus and putamen bilaterally. When corrected for age, duration of epilepsy was significantly correlated with FA loss of an anatomically plausible route - including ipsilateral parahippocampal gyrus and temporal lobe white matter, the thalamus bilaterally, and posterior regions of the corpus callosum that contain temporal lobe fibres - that may be suggestive of progressive brain degeneration in response to recurrent seizures. Chronic TLEhs is associated with interrelated DTI-derived and volume-derived brain degenerative abnormalities that are influenced by the duration of the disorder and the side of seizure onset. This work confirms previously contradictory findings by employing multi-modal imaging techniques in parallel in a large sample of patients.

Reorganization of Visual Callosal Connections Following Alterations of Retinal Input and Brain Damage

PubMed Central

Restani, Laura; Caleo, Matteo

2016-01-01

Vision is a very important sensory modality in humans. Visual disorders are numerous and arising from diverse and complex causes. Deficits in visual function are highly disabling from a social point of view and in addition cause a considerable economic burden. For all these reasons there is an intense effort by the scientific community to gather knowledge on visual deficit mechanisms and to find possible new strategies for recovery and treatment. In this review, we focus on an important and sometimes neglected player of the visual function, the corpus callosum (CC). The CC is the major white matter structure in the brain and is involved in information processing between the two hemispheres. In particular, visual callosal connections interconnect homologous areas of visual cortices, binding together the two halves of the visual field. This interhemispheric communication plays a significant role in visual cortical output. Here, we will first review the essential literature on the physiology of the callosal connections in normal vision. The available data support the view that the callosum contributes to both excitation and inhibition to the target hemisphere, with a dynamic adaptation to the strength of the incoming visual input. Next, we will focus on data showing how callosal connections may sense visual alterations and respond to the classical paradigm for the study of visual plasticity, i.e., monocular deprivation (MD). This is a prototypical example of a model for the study of callosal plasticity in pathological conditions (e.g., strabismus and amblyopia) characterized by unbalanced input from the two eyes. We will also discuss the findings of callosal alterations in blind subjects. Noteworthy, we will discuss data showing that inter-hemispheric transfer mediates recovery of visual responsiveness following cortical damage. Finally, we will provide an overview of how callosal projections dysfunction could contribute to pathologies such as neglect and occipital epilepsy. A particular focus will be on reviewing noninvasive brain stimulation techniques and optogenetic approaches that allow to selectively manipulate callosal function and to probe its involvement in cortical processing and plasticity. Overall, the data indicate that experience can potently impact on transcallosal connectivity, and that the callosum itself is crucial for plasticity and recovery in various disorders of the visual pathway. PMID:27895559

[Correlation between growth rate of corpus callosum and neuromotor development in preterm infants].

PubMed

Liu, Rui-Ke; Sun, Jie; Hu, Li-Yan; Liu, Fang

2015-08-01

To investigate the growth rate of corpus callosum by cranial ultrasound in very low birth weight preterm infants and to provide a reference for early evaluation and improvement of brain development. A total of 120 preterm infants under 33 weeks' gestation were recruited and divided into 26-29(+6) weeks group (n=64) and 30-32(+6) weeks group (n=56) according to the gestational age. The growth rate of corpus callosum was compared between the two groups. The correlation between the corpus callosum length and the cerebellar vermis length and the relationship of the growth rate of corpus callosum with clinical factors and the neuromotor development were analyzed. The growth rate of corpus callosum in preterm infants declined since 2 weeks after birth. Compared with the 30-32(+6) weeks group, the 26-29(+6) weeks group had a significantly lower growth rate of corpus callosum at 3-4 weeks after birth, at 5-6 weeks after birth, and from 7 weeks after birth to 40 weeks of corrected gestational age. There was a positive linear correlation between the corpus callosum length and the cerebellar vermis length. Small-for-gestational age infants had a low growth rate of corpus callosum at 2 weeks after birth. The 12 preterm infants with severe abnormal intellectual development had a lower growth rate of corpus callosum compared with the 108 preterm infants with non-severe abnormal intellectual development at 3-6 weeks after birth. The 5 preterm infants with severe abnormal motor development had a significantly lower growth rate of corpus callosum compared with the 115 preterm infants with non-severe abnormal motor development at 3-6 weeks after birth. The decline of growth rate of corpus callosum in preterm infants at 2-6 weeks after birth can increase the risk of severe abnormal neuromotor development.

Concomitant Fractional Anisotropy and Volumetric Abnormalities in Temporal Lobe Epilepsy: Cross-Sectional Evidence for Progressive Neurologic Injury

PubMed Central

Gerdes, Jan S.; Weber, Bernd; Deppe, Michael

2012-01-01

Background In patients with temporal lobe epilepsy and associated hippocampal sclerosis (TLEhs) there are brain abnormalities extending beyond the presumed epileptogenic zone as revealed separately in conventional magnetic resonance imaging (MRI) and MR diffusion tensor imaging (DTI) studies. However, little is known about the relation between macroscopic atrophy (revealed by volumetric MRI) and microstructural degeneration (inferred by DTI). Methodology/Principal Findings For 62 patients with unilateral TLEhs and 68 healthy controls, we determined volumes and mean fractional anisotropy (FA) of ipsilateral and contralateral brain structures from T1-weighted and DTI data, respectively. We report significant volume atrophy and FA alterations of temporal lobe, subcortical and callosal regions, which were more diffuse and bilateral in patients with left TLEhs relative to right TLEhs. We observed significant relationships between volume loss and mean FA, particularly of the thalamus and putamen bilaterally. When corrected for age, duration of epilepsy was significantly correlated with FA loss of an anatomically plausible route - including ipsilateral parahippocampal gyrus and temporal lobe white matter, the thalamus bilaterally, and posterior regions of the corpus callosum that contain temporal lobe fibres - that may be suggestive of progressive brain degeneration in response to recurrent seizures. Conclusions/Significance Chronic TLEhs is associated with interrelated DTI-derived and volume-derived brain degenerative abnormalities that are influenced by the duration of the disorder and the side of seizure onset. This work confirms previously contradictory findings by employing multi-modal imaging techniques in parallel in a large sample of patients. PMID:23071638

Caveolin1 Identifies a Specific Subpopulation of Cerebral Cortex Callosal Projection Neurons (CPN) Including Dual Projecting Cortical Callosal/Frontal Projection Neurons (CPN/FPN)

PubMed Central

2018-01-01

Abstract The neocortex is composed of many distinct subtypes of neurons that must form precise subtype-specific connections to enable the cortex to perform complex functions. Callosal projection neurons (CPN) are the broad population of commissural neurons that connect the cerebral hemispheres via the corpus callosum (CC). Currently, how the remarkable diversity of CPN subtypes and connectivity is specified, and how they differentiate to form highly precise and specific circuits, are largely unknown. We identify in mouse that the lipid-bound scaffolding domain protein Caveolin 1 (CAV1) is specifically expressed by a unique subpopulation of Layer V CPN that maintain dual ipsilateral frontal projections to premotor cortex. CAV1 is expressed by over 80% of these dual projecting callosal/frontal projection neurons (CPN/FPN), with expression peaking early postnatally as axonal and dendritic targets are being reached and refined. CAV1 is localized to the soma and dendrites of CPN/FPN, a unique population of neurons that shares information both between hemispheres and with premotor cortex, suggesting function during postmitotic development and refinement of these neurons, rather than in their specification. Consistent with this, we find that Cav1 function is not necessary for the early specification of CPN/FPN, or for projecting to their dual axonal targets. CPN subtype-specific expression of Cav1 identifies and characterizes a first molecular component that distinguishes this functionally unique projection neuron population, a population that expands in primates, and is prototypical of additional dual and higher-order projection neuron subtypes. PMID:29379878

Effect of growth hormone deficiency on brain structure, motor function and cognition.

PubMed

Webb, Emma A; O'Reilly, Michelle A; Clayden, Jonathan D; Seunarine, Kiran K; Chong, Wui K; Dale, Naomi; Salt, Alison; Clark, Chris A; Dattani, Mehul T

2012-01-01

The growth hormone-insulin-like growth factor-1 axis plays a role in normal brain growth but little is known of the effect of growth hormone deficiency on brain structure. Children with isolated growth hormone deficiency (peak growth hormone <6.7 µg/l) and idiopathic short stature (peak growth hormone >10 µg/l) underwent cognitive assessment, diffusion tensor imaging and volumetric magnetic resonance imaging prior to commencing growth hormone treatment. Total brain, corpus callosal, hippocampal, thalamic and basal ganglia volumes were determined using Freesurfer. Fractional anisotropy (a marker of white matter structural integrity) images were aligned and tract-based spatial statistics performed. Fifteen children (mean 8.8 years of age) with isolated growth hormone deficiency [peak growth hormone <6.7 µg/l (mean 3.5 µg/l)] and 14 controls (mean 8.4 years of age) with idiopathic short stature [peak growth hormone >10 µg/l (mean 15 µg/l) and normal growth rate] were recruited. Compared with controls, children with isolated growth hormone deficiency had lower Full-Scale IQ (P < 0.01), Verbal Comprehension Index (P < 0.01), Processing Speed Index (P < 0.05) and Movement-Assessment Battery for Children (P < 0.008) scores. Verbal Comprehension Index scores correlated significantly with insulin-like growth factor-1 (P < 0.03) and insulin-like growth factor binding protein-3 (P < 0.02) standard deviation scores in isolated growth hormone deficiency. The splenium of the corpus callosum, left globus pallidum, thalamus and hippocampus (P < 0.01) were significantly smaller; and corticospinal tract (bilaterally; P < 0.045, P < 0.05) and corpus callosum (P < 0.05) fractional anisotropy were significantly lower in the isolated growth hormone deficiency group. Basal ganglia volumes and bilateral corticospinal tract fractional anisotropy correlated significantly with Movement-Assessment Battery for Children scores, and corpus callosum fractional anisotropy with Full-Scale IQ and Processing Speed Index. In patients with isolated growth hormone deficiency, white matter abnormalities in the corpus callosum and corticospinal tract, and reduced thalamic and globus pallidum volumes relate to deficits in cognitive function and motor performance. Follow-up studies that investigate the course of the structural and cognitive deficits on growth hormone treatment are now required to confirm that growth hormone deficiency impacts significantly on brain structure, cognitive function and motor performance.

Fine motor skills and interhemispheric transfer in treatment-naive male children with Tourette syndrome.

PubMed

Buse, Judith; August, Julia; Bock, Nathalie; Dörfel, Denise; Rothenberger, Aribert; Roessner, Veit

2012-07-01

This study addressed whether Tourette syndrome is associated with an impairment of fine motor skills or altered interhemispheric transfer. We additionally investigated the association between interhemispheric transfer and size of the corpus callosum. The sample, a subsample of our larger neuroimaging sample, included 27 treatment-naive males with 'pure' Tourette syndrome (age range 10y 2mo-14y 4mo; mean age 11y 10mo, SD 1y 2mo) and 26 matched healthy comparison children (age range 10y 2mo-14y 4mo; mean age 11y 10mo, SD 1y 1mo). A finger tapping task and the Purdue Pegboard were used to assess fine motor skills. Interhemispheric transfer time (ITT) was measured with the Poffenberger paradigm. The neuroanatomical data were derived from our previous neuroimaging study. ITT was negatively correlated with the size of callosal subregion 3 (r=-0.366, p=0.028), indicating that a shorter ITT was associated with a larger corpus callosum. Our findings support the assumption that previously reported impairment of motor skills in Tourette syndrome does not directly result from tics but from other factors such as medication or comorbidities. Following the assumption that callosal subregion 3 in Tourette syndrome grows as a consequence of tic performance over years, our preliminary results suggest that this growth might accelerate interhemispheric transfer in Tourette syndrome. © The Authors. Developmental Medicine & Child Neurology © 2012 Mac Keith Press.

Extensive intracranial calcification of pseudo-TORCH syndrome with features of Dandy–Walker malformation

PubMed Central

Patnaik, Ashis; Mishra, Sudhansu Sekhar; Das, Srikanta

2017-01-01

Pseudo-TORCH syndrome or congenital infection-like syndrome is a group of conditions which resemble congenital infections such as those caused by toxoplasmosis, rubella, cytomegalovirus (CMV), herpes (TORCH) group of organisms, clinico-radiologically, but serological tests are negative for the organisms. One of the variety shows features such as microcephaly, extensive intracranial calcification showing gross resemblance to congenital CMV infection, making its other name as microcephaly intracranial calcification syndrome (MICS). Dandy–Walker malformation (DWM), in addition to posterior fossa large cyst, cerebellar vermis hypoplasia, and hydrocephalus is often associated with agenesis of the corpus callosum and callosal lipomas, dysplasia of the brainstem, and cerebellar hypoplasia or dysgenesis. But radiological features of DWM with microcephaly and intracranial calcification are very unusual and have been rarely reported in the literature.[1] We report a case of infant showing clinical features suggestive of congenital CMV infection with negative serology and radiological imaging suggestive of DWM with extensive intracranial calcification. Pseudo-TORCH syndrome with radiological features of DWM is a congenital developmental abnormality. Inspite of hydrocephalus, it does not require cerebrospinal fluid (CSF) diversionary procedure due to lack of increased intracranial pressure. Conservative management for seizure disorder is the optimal therapy. PMID:28761539

Extensive intracranial calcification of pseudo-TORCH syndrome with features of Dandy-Walker malformation.

PubMed

Patnaik, Ashis; Mishra, Sudhansu Sekhar; Das, Srikanta

2017-01-01

Pseudo-TORCH syndrome or congenital infection-like syndrome is a group of conditions which resemble congenital infections such as those caused by toxoplasmosis, rubella, cytomegalovirus (CMV), herpes (TORCH) group of organisms, clinico-radiologically, but serological tests are negative for the organisms. One of the variety shows features such as microcephaly, extensive intracranial calcification showing gross resemblance to congenital CMV infection, making its other name as microcephaly intracranial calcification syndrome (MICS). Dandy-Walker malformation (DWM), in addition to posterior fossa large cyst, cerebellar vermis hypoplasia, and hydrocephalus is often associated with agenesis of the corpus callosum and callosal lipomas, dysplasia of the brainstem, and cerebellar hypoplasia or dysgenesis. But radiological features of DWM with microcephaly and intracranial calcification are very unusual and have been rarely reported in the literature.[1] We report a case of infant showing clinical features suggestive of congenital CMV infection with negative serology and radiological imaging suggestive of DWM with extensive intracranial calcification. Pseudo-TORCH syndrome with radiological features of DWM is a congenital developmental abnormality. Inspite of hydrocephalus, it does not require cerebrospinal fluid (CSF) diversionary procedure due to lack of increased intracranial pressure. Conservative management for seizure disorder is the optimal therapy.

Callosal hyperintensities and gait speed gain from two types of mobility interventions in older adults.

PubMed

Nadkarni, Neelesh K; Perera, Subashan; Studenski, Stephanie A; Rosano, Caterina; Aizenstein, Howard J; VanSwearingen, Jessie M

2015-06-01

To assess whether the volume of callosal hyperintensities in the genu and splenium of older adults with mobility impairment is differentially associated with the degree of gain in gait speed after 2 types of gait interventions. Single-blind randomized controlled trial of 2 types of gait exercises in older adults. Research center in an academic institution. Ambulatory adults (N=44) aged ≥65 years with a slow and variable gait. Twelve-week physical therapist-guided trial of a conventional walking, endurance, balance, and strength (WEBS) intervention (n=20) versus a timing and coordination of gait (TC) intervention (n=22). Gain in gait speed after the intervention and its relation to callosal hyperintensities in the genu and splenium of the corpus callosum. Gait speed improved in both the WEBS group (mean change, 0.16m/s) and the TC group (mean change, 0.21m/s; both P<.05). The volume of white matter hypertintensities (WMHs) in the genu was differentially associated with gait speed gain (group × genual WMH interaction, P=.05). Greater genual WMH volume was related to a smaller gait speed gain in the WEBS group (P=.01) but not in the TC (P=.10) group. Splenial WMH volume was not differentially associated with gait speed gain (interaction, P=.90). Callosal hyperintensities differentially influence gait speed gain by the type of gait rehabilitation. Mobility impaired older adults with genual hyperintensities may benefit from a rehabilitation program focused on motor skill learning rather than on strength and endurance training. Copyright © 2015 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Hyperlexia and ambient echolalia in a case of cerebral infarction of the left anterior cingulate cortex and corpus callosum.

PubMed

Suzuki, Tadashi; Itoh, Shouichi; Hayashi, Mototaka; Kouno, Masako; Takeda, Katsuhiko

2009-10-01

We report the case of a 69-year-old woman with cerebral infarction in the left anterior cingulate cortex and corpus callosum. She showed hyperlexia, which was a distinctive reading phenomenon, as well as ambient echolalia. Clinical features also included complex disorders such as visual groping, compulsive manipulation of tools, and callosal disconnection syndrome. She read words written on the cover of a book and repeated words emanating from unrelated conversations around her or from hospital announcements. The combination of these two features due to a focal lesion has never been reported previously. The supplementary motor area may control the execution of established subroutines according to external and internal inputs. Hyperlexia as well as the compulsive manipulation of tools could be interpreted as faulty inhibition of preexisting essentially intact motor subroutines by damage to the anterior cingulate cortex reciprocally interconnected with the supplementary motor area.

Structural changes of the corpus callosum in tinnitus

PubMed Central

Diesch, Eugen; Schummer, Verena; Kramer, Martin; Rupp, Andre

2012-01-01

Objectives: In tinnitus, several brain regions seem to be structurally altered, including the medial partition of Heschl's gyrus (mHG), the site of the primary auditory cortex. The mHG is smaller in tinnitus patients than in healthy controls. The corpus callosum (CC) is the main interhemispheric commissure of the brain connecting the auditory areas of the left and the right hemisphere. Here, we investigate whether tinnitus status is associated with CC volume. Methods: The midsagittal cross-sectional area of the CC was examined in tinnitus patients and healthy controls in which an examination of the mHG had been carried out earlier. The CC was extracted and segmented into subregions which were defined according to the most common CC morphometry schemes introduced by Witelson (1989) and Hofer and Frahm (2006). Results: For both CC segmentation schemes, the CC posterior midbody was smaller in male patients than in male healthy controls and the isthmus, the anterior midbody, and the genou were larger in female patients than in female controls. With CC size normalized relative to mHG volume, the normalized CC splenium was larger in male patients than male controls and the normalized CC splenium, the isthmus and the genou were larger in female patients than female controls. Normalized CC segment size expresses callosal interconnectivity relative to auditory cortex volume. Conclusion: It may be argued that the predominant function of the CC is excitatory. The stronger callosal interconnectivity in tinnitus patients, compared to healthy controls, may facilitate the emergence and maintenance of a positive feedback loop between tinnitus generators located in the two hemispheres. PMID:22470322

CYCLIN-DEPENDENT KINASE G1 Is Associated with the Spliceosome to Regulate CALLOSE SYNTHASE5 Splicing and Pollen Wall Formation in Arabidopsis[C][W][OA

PubMed Central

Huang, Xue-Yong; Niu, Jin; Sun, Ming-Xi; Zhu, Jun; Gao, Ju-Fang; Yang, Jun; Zhou, Que; Yang, Zhong-Nan

2013-01-01

Arabidopsis thaliana CYCLIN-DEPEDENT KINASE G1 (CDKG1) belongs to the family of cyclin-dependent protein kinases that were originally characterized as cell cycle regulators in eukaryotes. Here, we report that CDKG1 regulates pre-mRNA splicing of CALLOSE SYNTHASE5 (CalS5) and, therefore, pollen wall formation. The knockout mutant cdkg1 exhibits reduced male fertility with impaired callose synthesis and abnormal pollen wall formation. The sixth intron in CalS5 pre-mRNA, a rare type of intron with a GC 5′ splice site, is abnormally spliced in cdkg1. RNA immunoprecipitation analysis suggests that CDKG1 is associated with this intron. CDKG1 contains N-terminal Ser/Arg (RS) motifs and interacts with splicing factor Arginine/Serine-Rich Zinc Knuckle-Containing Protein33 (RSZ33) through its RS region to regulate proper splicing. CDKG1 and RS-containing Zinc Finger Protein22 (SRZ22), a splicing factor interacting with RSZ33 and U1 small nuclear ribonucleoprotein particle (snRNP) component U1-70k, colocalize in nuclear speckles and reside in the same complex. We propose that CDKG1 is recruited to U1 snRNP through RSZ33 to facilitate the splicing of the sixth intron of CalS5. PMID:23404887

Two callose synthases, GSL1 and GSL5, play an essential and redundant role in plant and pollen development and in fertility.

PubMed

Enns, Linda C; Kanaoka, Masahiro M; Torii, Keiko U; Comai, Luca; Okada, Kiyotaka; Cleland, Robert E

2005-06-01

Callose, a beta-1,3-glucan that is widespread in plants, is synthesized by callose synthase. Arabidopsis thaliana contains a family of 12 putative callose synthase genes (GSL1-12). The role of callose and of the individual genes in plant development is still largely uncertain. We have now used TILLING and T-DNA insertion mutants (gsl1-1, gsl5-2 and gsl5-3) to study the role of two closely related and linked genes, GSL1 and GSL5, in sporophytic development and in reproduction. Both genes are expressed in all parts of the plant. Sporophytic development was nearly normal in gsl1-1 homozygotes and only moderately defective in homozygotes for either of the two gsl5 alleles. On the other hand, plants that were gsl1-1/+ gsl5/gsl5 were severely defective, with smaller leaves, shorter roots and bolts and smaller flowers. Plants were fertile when the sporophytes had either two wild-type GSL1 alleles, or one GSL5 allele in a gsl1-1 background, but gsl1-1/+ gsl5/gsl5 plants produced an extremely reduced number of viable seeds. A chromosome with mutations in both GSL1 and GSL5 rendered pollen infertile, although such a chromosome could be transmitted via the egg. As a result, it was not possible to obtain plants that were homozygous for mutations in both the GSL genes. Pollen grain development was severely affected in double mutant plants. Many pollen grains were collapsed and inviable in the gsl1-1/gsl1-1 gsl5/+ and gsl1-1/+ gsl5/gsl5 plants. In addition, gsl1-1/+ gsl5/gsl5 plants produced abnormally large pollen with unusual pore structures, and had problems with tetrad dissociation. In this particular genotype, while the callose wall formed around the pollen mother cells, no callose wall separated the resulting tetrads. We conclude that GSL1 and GSL5 play important, but at least partially redundant roles in both sporophytic development and in the development of pollen. They are responsible for the formation of the callose wall that separates the microspores of the tetrad, and also play a gametophytic role later in pollen grain maturation. Other GSL genes may control callose formation at different steps during pollen development.

Left hand tactile agnosia after posterior callosal lesion.

PubMed

Balsamo, Maddalena; Trojano, Luigi; Giamundo, Arcangelo; Grossi, Dario

2008-09-01

We report a patient with a hemorrhagic lesion encroaching upon the posterior third of the corpus callosum but sparing the splenium. She showed marked difficulties in recognizing objects and shapes perceived through her left hand, while she could appreciate elementary sensorial features of items tactually presented to the same hand flawlessly. This picture, corresponding to classical descriptions of unilateral associative tactile agnosia, was associated with finger agnosia of the left hand. This very unusual case report can be interpreted as an instance of disconnection syndrome, and allows a discussion of mechanisms involved in tactile object recognition.

The benefit of image guidance for the contralateral interhemispheric approach to the lateral ventricle.

PubMed

Fronda, Chiara; Miller, Dorothea; Kappus, Christoph; Bertalanffy, Helmut; Sure, Ulrich

2008-06-01

Recently, neurosurgeons have increasingly faced small intracerebral lesions in asymptomatic or minimally symptomatic patients. Here, we evaluated a series of four patients with nearly asymptomatic intraventricular tumors close to the corpus callosum that had been treated with the aid of an image-guided transcallosal approach. Four consecutive patients suffering from left intra- and paraventricular tumors were operated on via a contralateral interhemispheric transcallosal approach with the aid of neuronavigation. Our image-guided system directed: (1) the skin incision, (2) the interhemispheric dissection, and (3) the incision of the corpus callosum. Using the image-guided contralateral interhemispheric transcallosal approach to the left ventricle all lesions have been completely resected without the risk of damage to the dominant hemisphere. The callosal incision was kept as limited as possible (1.2-2.1cm) depending on the size of the tumor. No postoperative neurological or neuropsychological deficit was observed in our series. Neuronavigation facilitates a safe and targeted contralateral interhemispheric transcallosal approach to the dominant hemisphere's lateral ventricle. Our technique minimizes the risk of damage to the dominant hemisphere and requires only a limited opening of the corpus callosum, which might decrease the risk of neuropsychological morbidity.

Utilizing Mutual Information Analysis to Explore the Relationship Between Gray and White Matter Structural Pathologies in Schizophrenia.

PubMed

Lyall, Amanda E; Savadjiev, Peter; Del Re, Elisabetta C; Seitz, Johanna; O'Donnell, Lauren J; Westin, Carl-Fredrik; Mesholam-Gately, Raquelle I; Petryshen, Tracey; Wojcik, Joanne D; Nestor, Paul; Niznikiewicz, Margaret; Goldstein, Jill; Seidman, Larry J; McCarley, Robert W; Shenton, Martha E; Kubicki, Marek

2018-04-03

Schizophrenia has been characterized as a neurodevelopmental disorder, with structural brain abnormalities reported at all stages. However, at present, it remains unclear whether gray and white matter abnormalities represent related or independent pathologies in schizophrenia. In this study, we present findings from an integrative analysis exploring the morphological relationship between gray and white matter in 45 schizophrenia participants and 49 healthy controls. We utilized mutual information (MI), a measure of how much information two variables share, to assess the morphological dependence between gray and white matter in three segments of the corpus callsoum, and the gray matter regions these segments connect: (1) the genu and the left and right rostral middle frontal gyrus (rMFG), (2) the isthmus and the left and right superior temporal gyrus (STG), (3) the splenium and the left and right lateral occipital gyrus (LOG). We report significantly reduced MI between white matter tract dispersion of the right hemispheric callosal connections to the STG and both cortical thickness and area in the right STG in schizophrenia patients, despite a lack of group differences in cortical thickness, surface area, or dispersion. We believe that this reduction in morphological dependence between gray and white matter may reflect a possible decoupling of the developmental processes that shape morphological features of white and gray matter early in life. The present study also demonstrates the importance of studying the relationship between gray and white matter measures, as opposed to restricting analyses to gray and white matter measures independently.

Microstructure of transcallosal motor fibers reflects type of cortical (re-)organization in congenital hemiparesis.

PubMed

Juenger, Hendrik; Koerte, Inga K; Muehlmann, Marc; Mayinger, Michael; Mall, Volker; Krägeloh-Mann, Ingeborg; Shenton, Martha E; Berweck, Steffen; Staudt, Martin; Heinen, Florian

2014-11-01

Early unilateral brain lesions can lead to different types of corticospinal (re-)organization of motor networks. In one group of patients, the contralesional hemisphere exerts motor control not only over the contralateral non-paretic hand but also over the (ipsilateral) paretic hand, as the primary motor cortex is (re-)organized in the contralesional hemisphere. Another group of patients with early unilateral lesions shows "normal" contralateral motor projections starting in the lesioned hemisphere. We investigated how these different patterns of cortical (re-)organization affect interhemispheric transcallosal connectivity in patients with congenital hemiparesis. Eight patients with ipsilateral motor projections (group IPSI) versus 7 patients with contralateral motor projections (group CONTRA) underwent magnetic resonance diffusion tensor imaging (DTI). The corpus callosum (CC) was subdivided in 5 areas (I-V) in the mid-sagittal slice and volumetric information. The following diffusion parameters were calculated: fractional anisotropy (FA), trace, radial diffusivity (RD), and axial diffusivity (AD). DTI revealed significantly lower FA, increased trace and RD for group IPSI compared to group CONTRA in area III of the corpus callosum, where transcallosal motor fibers cross the CC. In the directly neighboring area IV, where transcallosal somatosensory fibers cross the CC, no differences were found for these DTI parameters between IPSI and CONTRA. Volume of callosal subsections showed significant differences for area II (connecting premotor cortices) and III, where group IPSI had lower volume. The results of this study demonstrate that the callosal microstructure in patients with congenital hemiparesis reflects the type of cortical (re-)organization. Early lesions disrupting corticospinal motor projections to the paretic hand consecutively affect the development or maintenance of transcallosal motor fibers. Copyright © 2014 European Paediatric Neurology Society. Published by Elsevier Ltd. All rights reserved.

Corpus Callosum Area in Children and Adults with Autism

ERIC Educational Resources Information Center

Prigge, Molly B. D.; Lange, Nicholas; Bigler, Erin D.; Merkley, Tricia L.; Neeley, E. Shannon; Abildskov, Tracy J.; Froehlich, Alyson L.; Nielsen, Jared A.; Cooperrider, Jason R.; Cariello, Annahir N.; Ravichandran, Caitlin; Alexander, Andrew L.; Lainhart, Janet E.

2013-01-01

Despite repeated findings of abnormal corpus callosum structure in autism, the developmental trajectories of corpus callosum growth in the disorder have not yet been reported. In this study, we examined corpus callosum size from a developmental perspective across a 30-year age range in a large cross-sectional sample of individuals with autism…

Callosal Influence on Visual Receptive Fields Has an Ocular, an Orientation-and Direction Bias.

PubMed

Conde-Ocazionez, Sergio A; Jungen, Christiane; Wunderle, Thomas; Eriksson, David; Neuenschwander, Sergio; Schmidt, Kerstin E

2018-01-01

One leading hypothesis on the nature of visual callosal connections (CC) is that they replicate features of intrahemispheric lateral connections. However, CC act also in the central part of the binocular visual field. In agreement, early experiments in cats indicated that they provide the ipsilateral eye part of binocular receptive fields (RFs) at the vertical midline (Berlucchi and Rizzolatti, 1968), and play a key role in stereoscopic function. But until today callosal inputs to receptive fields activated by one or both eyes were never compared simultaneously, because callosal function has been often studied by cutting or lesioning either corpus callosum or optic chiasm not allowing such a comparison. To investigate the functional contribution of CC in the intact cat visual system we recorded both monocular and binocular neuronal spiking responses and receptive fields in the 17/18 transition zone during reversible deactivation of the contralateral hemisphere. Unexpectedly from many of the previous reports, we observe no change in ocular dominance during CC deactivation. Throughout the transition zone, a majority of RFs shrink, but several also increase in size. RFs are significantly more affected for ipsi- as opposed to contralateral stimulation, but changes are also observed with binocular stimulation. Noteworthy, RF shrinkages are tiny and not correlated to the profound decreases of monocular and binocular firing rates. They depend more on orientation and direction preference than on eccentricity or ocular dominance of the receiving neuron's RF. Our findings confirm that in binocularly viewing mammals, binocular RFs near the midline are constructed via the direct geniculo-cortical pathway. They also support the idea that input from the two eyes complement each other through CC: Rather than linking parts of RFs separated by the vertical meridian, CC convey a modulatory influence, reflecting the feature selectivity of lateral circuits, with a strong cardinal bias.

The VPAC2 agonist peptide histidine isoleucine (PHI) up-regulates glutamate transport in the corpus callosum of a rat model of amyotrophic lateral sclerosis (hSOD1G93A) by inhibiting caspase-3 mediated inactivation of GLT-1a.

PubMed

Goursaud, Stéphanie; Focant, Marylène C; Berger, Julie V; Nizet, Yannick; Maloteaux, Jean-Marie; Hermans, Emmanuel

2011-10-01

Degeneration of corpus callosum appears in patients with amyotrophic lateral sclerosis (ALS) before clinical signs of upper motor neuron death. Considering the ALS-associated impairment of astrocytic glutamate uptake, we have characterized the expression and activity of the glutamate transporter isoforms GLT-1a and GLT-1b in the corpus callosum of transgenic rats expressing a mutated form of the human superoxide dismutase 1 (hSOD1(G93A)). We have also studied the effect of peptide histidine isoleucine (PHI), a vasoactive intestinal peptide (VIP)/pituitary adenylate cyclase-activating polypeptide (PACAP) receptor 2 (VPAC(2)) agonist on glutamate transporters both in vivo and in callosal astrocytes. Before the onset of motor symptoms, the expression of both transporter isoforms was correlated with a constitutive activity of caspase-3. This enzyme participates in the down-regulation of GLT-1 in ALS, and here we demonstrated its involvement in the selective degradation of GLT-1a in the white matter. A single stereotactic injection of PHI into the corpus callosum of symptomatic rats decreased caspase-3 activity and promoted GLT-1a expression and uptake activity. Together, with evidence for a reduced expression of prepro-VIP/PHI mRNA in the corpus callosum of transgenic animals, these data shed light on the modulatory role of the VIP/PHI system on the glutamatergic transmission in ALS.

Correlation between corpus callosum sub-segmental area and cognitive processes in school-age children.

PubMed

Moreno, Martha Beatriz; Concha, Luis; González-Santos, Leopoldo; Ortiz, Juan Jose; Barrios, Fernando Alejandro

2014-01-01

We assessed the relationship between structural characteristics (area) and microstructure (apparent diffusion coefficient; ADC) of the corpus callosum (CC) in 57 healthy children aged 7.0 to 9.1 years, with diverse cognitive and academic abilities as well as executive functions evaluated with a neuropsychological battery for children. The CC was manually delineated and sub-segmented into six regions, and their ADC and area were measured. There were no significant differences between genders in the callosal region area or in ADC. The CC area and ADC, mainly of anterior regions, correlated with different cognitive abilities for each gender. Our results suggest that the relationship between cognitive abilities and CC characteristics is different between girls and boys and between the anterior and posterior regions of the CC. Furthermore, these findings strenghten the idea that regardless of the different interhemispheric connectivity schemes per gender, the results of cognitive tasks are very similar for girls and boys throughout childhood.

Correlation between Corpus Callosum Sub-Segmental Area and Cognitive Processes in School-Age Children

PubMed Central

Moreno, Martha Beatriz; Concha, Luis; González-Santos, Leopoldo; Ortiz, Juan Jose; Barrios, Fernando Alejandro

2014-01-01

We assessed the relationship between structural characteristics (area) and microstructure (apparent diffusion coefficient; ADC) of the corpus callosum (CC) in 57 healthy children aged 7.0 to 9.1 years, with diverse cognitive and academic abilities as well as executive functions evaluated with a neuropsychological battery for children. The CC was manually delineated and sub-segmented into six regions, and their ADC and area were measured. There were no significant differences between genders in the callosal region area or in ADC. The CC area and ADC, mainly of anterior regions, correlated with different cognitive abilities for each gender. Our results suggest that the relationship between cognitive abilities and CC characteristics is different between girls and boys and between the anterior and posterior regions of the CC. Furthermore, these findings strenghten the idea that regardless of the different interhemispheric connectivity schemes per gender, the results of cognitive tasks are very similar for girls and boys throughout childhood. PMID:25170897

SPG11 Presenting with Tremor

PubMed Central

Schneider, Susanne A.; Mummery, Catherine J.; Mehrabian, Mohadeseh; Houlden, Henry; Bain, Peter G.

2012-01-01

Background Hereditary spastic paraplegias (HSPs) are a clinically and genetically heterogeneous group of neurological diseases, which typically present with progressive lower extremity weakness and spasticity causing progressive walking difficulties. Complicating neurological or extraneurological features may be present. Case Report We describe a 19-year-old male who was referred because of an action tremor of the hands; he later developed walking difficulties. Callosal atrophy was present on his cerebral magnetic resonance imaging scan, prompting genetic testing for SPG11, which revealed homozygous mutations. Discussion The clinical features, differential diagnosis and management of SPG11, the most common form of autosomal recessive complicated HSP with a thin corpus callosum are discussed. PMID:23439843

Influence of callosal transfer on visual cortical evoked response and the implication in the development of a visual prosthesis.

PubMed

Siu, Timothy L; Morley, John W

2007-12-01

The development of a visual prosthesis has been limited by an incomplete understanding of functional changes of the visual cortex accompanying deafferentation. In particular, the role of the corpus callosum in modulating these changes has not been fully evaluated. Recent experimental evidence suggests that through synaptic modulation, short-term (4-5 days) visual deafferentation can induce plastic changes in the visual cortex, leading to adaptive enhancement of residual visual input. We therefore investigated whether a compensatory rerouting of visual information can occur via the indirect transcallosal linkage after deafferentation and the influence of this interhemispheric communication on the visual evoked response of each hemisphere. In albino rabbits, misrouting of uncrossed optic fibres reduces ipsilateral input to a negligible degree. We thus took advantage of this congenital anomaly to model unilateral cortical and ocular deafferentation by eliminating visual input from one eye and recorded the visual evoked potential (VEP) from the intact eye. In keeping with the chiasmal anomaly, no VEP was elicited from the hemisphere ipsilateral to the intact eye. This remained unchanged following unilateral visual deafferentation. The amplitude and latency of the VEP in the fellow hemisphere, however, were significantly decreased in the deafferented animals. Our data suggest that callosal linkage does not contribute to visual evoked responses and this is not changed after short-term deafferentation. The decrease in amplitude and latency of evoked responses in the hemisphere ipsilateral to the treated eye, however, confirms the facilitatory role of callosal transfer. This observation highlights the importance of bicortical stimulation in the future design of a cortical visual prosthesis.

Segmentation of the Canine Corpus Callosum using Diffusion Tensor Imaging Tractography

PubMed Central

Pierce, T.T.; Calabrese, E.; White, L.E.; Chen, S.D.; Platt, S.R.; Provenzale, J.M.

2014-01-01

Background We set out to determine functional white matter (WM) connections passing through the canine corpus callosum useful for subsequent studies of canine brains that serve as models for human WM pathway disease. Based on prior studies, we anticipated that the anterior corpus callosum would send projections to the anterior cerebral cortex while progressively posterior segments would send projections to more posterior cortex. Methods A post mortem canine brain was imaged using a 7T MRI producing 100 micron isotropic resolution DTI analyzed by tractography. Using ROIs within cortical locations, which were confirmed by a Nissl stain that identified distinct cortical architecture, we successfully identified 6 important WM pathways. We also compared fractional anisotropy (FA), apparent diffusion coefficient (ADC), radial diffusivity (RD), and axial diffusivity (AD) in tracts passing through the genu and splenium. Results Callosal fibers were organized based upon cortical destination, i.e. fibers from the genu project to the frontal cortex. Histologic results identified the motor cortex based on cytoarchitectonic criteria that allowed placement of ROIs to discriminate between frontal and parietal lobes. We also identified cytoarchitecture typical of the orbital frontal, anterior frontal, and occipital regions and placed ROIs accordingly. FA, ADC, RD and AD values were all higher in posterior corpus callosum fiber tracts. Conclusions Using 6 cortical ROIs, we identified 6 major white matter tracts that reflect major functional divisions of the cerebral hemispheres and we derived quantitative values that can be used for study of canine models of human WM pathological states. PMID:24370161

Inter-hemispheric wave propagation failures in traumatic brain injury are indicative of callosal damage.

PubMed

Spiegel, Daniel P; Laguë-Beauvais, Maude; Sharma, Gaurav; Farivar, Reza

2015-04-01

Approximately 3.2-5.3 million Americans live with the consequences of a traumatic brain injury (TBI), making TBI one of the most common causes of disability in the world. Visual deficits often accompany TBI but physiological and anatomical evidence for injury in mild TBI is lacking. Axons traversing the corpus callosum are particularly vulnerable to TBI. Hemifield representations of early visual areas are linked by bundles of fibers that together cross the corpus callosum while maintaining their topographic relations. Given the increased vulnerability of the long visual axons traversing the corpus callosum, we hypothesized that inter-hemispheric transmission for vision will be impaired following mild TBI. Using the travelling wave paradigm (Wilson, Blake, & Lee 2001), we measured inter-hemispheric transmission in terms of both speed and propagation failures in 14 mild TBI patients and 14 age-matched controls. We found that relative to intra-hemispheric waves, inter-hemispheric waves were faster and that the inter-hemispheric propagation failures were more common in TBI patients. Furthermore, the transmission failures were topographically distributed, with a bias towards greater failures for transmission across the upper visual field. We discuss the results in terms of increased local inhibition and topographically-selective axonal injury in mild TBI. Copyright © 2015 Elsevier Ltd. All rights reserved.

Microstructural Corpus Callosum Anomalies in Children With Prenatal Alcohol Exposure: An Extension of Previous Diffusion Tensor Imaging Findings

PubMed Central

Wozniak, Jeffrey R.; Muetzel, Ryan L.; Mueller, Bryon A.; McGee, Christie L.; Freerks, Melesa A.; Ward, Erin E.; Nelson, Miranda L.; Chang, Pi-Nian; Lim, Kelvin O.

2010-01-01

Background Several studies have now shown corpus callosum abnormalities using diffusion tensor imaging (DTI) in children with fetal alcohol spectrum disorders (FASD) in comparison with nonexposed controls. The data suggest that posterior regions of the callosum may be disproportionately affected. The current study builds on previous efforts, including our own work, and moves beyond midline corpus callosum to probe major inter-hemispheric white matter pathways with an improved DTI tractographic method. This study also expands on our prior work by evaluating a larger sample and by incorporating children with a broader range of clinical effects including full-criteria fetal alcohol syndrome (FAS). Methods Participants included 33 children with FASD (8 FAS, 23 partial FAS, 2 static encephalopathy) and 19 nonexposed controls between the ages of 10 and 17 years. Participants underwent DTI scans and intelligence testing. Groups (FASD vs. controls) were compared on fractional anisotropy (FA) and mean diffusivity (MD) in 6 white matter tracts projected through the corpus callosum. Exploratory analyses were also conducted examining the relationships between DTI measures in the corpus callosum and measures of intellectual functioning and facial dysmorphology. Results In comparison with the control group, the FASD group had significantly lower FA in 3 posterior tracts of the corpus callosum: the posterior mid-body, the isthmus, and the splenium. A trend-level finding also suggested lower FA in the genu. Measures of white matter integrity and cognition were correlated and suggest some regional specificity, in that only posterior regions of the corpus callosum were associated with visual-perceptual skills. Correlations between measures of facial dysmorphology and posterior regions of the corpus callosum were nonsignificant. Conclusions Consistent with previous DTI studies, these results suggest that microstructural posterior corpus callosum abnormalities are present in children with prenatal alcohol exposure and cognitive impairment. These abnormalities are clinically relevant because they are associated with cognitive deficits and appear to provide evidence of abnormalities associated with prenatal alcohol exposure independent of dysmorphic features. As such, they may yield important diagnostic and prognostic information not provided by the traditional facial characteristics. PMID:19645729

Diffusion tensor imaging and myelin composition analysis reveal abnormal myelination in corpus callosum of canine mucopolysaccharidosis I

PubMed Central

Provenzale, James M.; Nestrasil, Igor; Chen, Steven; Kan, Shih-hsin; Le, Steven Q.; Jens, Jacqueline K.; Snella, Elizabeth M.; Vondrak, Kristen N.; Yee, Jennifer K.; Vite, Charles H.; Elashoff, David; Duan, Lewei; Wang, Raymond Y.; Ellinwood, N. Matthew; Guzman, Miguel A.; Shapiro, Elsa G.; Dickson, Patricia I.

2015-01-01

Children with mucopolysaccharidosis I (MPS I) develop hyperintense white matter foci on T2-weighted brain magnetic resonance (MR) imaging that are associated clinically with cognitive impairment. We report here a diffusion tensor imaging (DTI) and tissue evaluation of white matter in a canine model of MPS I. We found that two DTI parameters, fractional anisotropy (a measure of white matter integrity) and radial diffusivity (which reflects degree of myelination) were abnormal in the corpus callosum of MPS I dogs compared to carrier controls. Tissue studies of the corpus callosum showed reduced expression of myelin-related genes and an abnormal composition of myelin in MPS I dogs. We treated MPS I dogs with recombinant alpha-l-iduronidase, which is the enzyme that is deficient in MPS I disease. The recombinant alpha-l-iduronidase was administered by intrathecal injection into the cisterna magna. Treated dogs showed partial correction of corpus callosum myelination. Our findings suggest that abnormal myelination occurs in the canine MPS I brain, that it may underlie clinically-relevant brain imaging findings in human MPS I patients, and that it may respond to treatment. PMID:26222335

Defining the nature of the cerebral abnormalities in the premature infant: a qualitative magnetic resonance imaging study.

PubMed

Inder, Terrie E; Wells, Scott J; Mogridge, Nina B; Spencer, Carole; Volpe, Joseph J

2003-08-01

The aim of this study was to define qualitatively the nature and extent of white and gray matter abnormalities in a longitudinal population-based study of infants with very low birth weight. Perinatal factors were then related to the presence and severity of magnetic resonance imaging (MRI) abnormalities. From November 1998 to December 2000, 100 consecutive premature infants admitted to the neonatal intensive care unit at Christchurch Women's Hospital were recruited (98% eligible) after informed parental consent to undergo an MRI scan at term equivalent. The scans were analyzed by a single neuroradiologist experienced in pediatric MRI, with a second independent scoring of the MRI using a combination of criteria for white matter (cysts, signal abnormality, loss of volume, ventriculomegaly, corpus callosal thinning, myelination) and gray matter (gray matter signal abnormality, gyration, subarachnoid space). Results were analyzed against individual item scores as well as the presence of moderate-severe white matter score, total gray matter score, and total brain score. The mean gestational age was 27.9+/-2.4 weeks (range, 23-32 weeks), and mean birth weight was 1063+/-292 g. The greatest univariate predictors for moderate-severe white matter abnormality were lower gestational age (odds ratio [OR], 1.3; 95% confidence interval [CI], 1.1-1.7; P<.01), maternal fever (OR, 2.2; 95% CI, 1.1-4.6; P<.04), proven sepsis in the infant at delivery (OR, 1.8; 95% CI, 1.1-3.6; P=0.03), inotropic support (OR, 2.7; 95% CI, 1.5-4.5; P<.001), patent ductus arteriosus (OR, 2.2; 95% CI, 1.2-3.8; P=.01), grade III/IV intraventricular hemorrhage (P=.015), and the occurrence of a pneumothorax (P=.05). There was a significant protective effect of intrauterine growth restriction (OR, 0.51; 95% CI, 0.23-0.99; P=.04). Gray matter abnormality was highly related to the presence and severity of white matter abnormality. A unique pattern of cerebral abnormality consisting of significant diffuse white matter atrophy, ventriculomegaly, immature gyral development, and enlarged subarachnoid space was found in 10 of 11 infants with birth gestation <26 weeks. Given the later outcome of these infants, this pattern may have very high risk for later global neurodevelopmental disability. This MRI study confirms a high incidence of cerebral white matter abnormality at term in an unselected population of premature infants, which is predominantly a result of noncystic injury in the extremely immature infant. We confirm that the major perinatal risk factors for white matter abnormality are related to perinatal infection, particularly maternal fever and infant sepsis, and hypotension with inotrope use. We have defined a distinct pattern of diffuse white and gray matter abnormality in the extremely immature infant.

Age-Specific Dynamics of Corpus Callosum Development in Children and its Peculiarities in Infantile Cerebral Palsy.

PubMed

Krasnoshchekova, E I; Zykin, P A; Tkachenko, L A; Aleksandrov, T A; Sereda, V M; Yalfimov, A N

2016-10-01

The age dynamics of corpus callosum development was studied on magnetic resonance images of the brain in children aged 2-11 years without neurological abnormalities and with infantile cerebral palsy. The areas of the total corpus callosum and its segments are compared in the midsagittal images. Analysis is carried out with the use of an original formula: proportion of areas of the anterior (genu, CC2; and anterior part, CC3) and posterior (isthmus, CC6 and splenium, CC7) segments: kCC=(CC2+CC3)×CC6/CC7. The results characterize age-specific dynamics of the corpus callosum development and can be used for differentiation, with high confidence, of the brain of children without neurological abnormalities from the brain patients with infantile cerebral palsy.

Segmentation of the canine corpus callosum using diffusion-tensor imaging tractography.

PubMed

Pierce, Theodore T; Calabrese, Evan; White, Leonard E; Chen, Steven D; Platt, Simon R; Provenzale, James M

2014-01-01

We set out to determine functional white matter (WM) connections passing through the canine corpus callosum; these WM connections would be useful for subsequent studies of canine brains that serve as models for human WM pathway disease. Based on prior studies, we anticipated that the anterior corpus callosum would send projections to the anterior cerebral cortex whereas progressively posterior segments would send projections to more posterior cortex. A postmortem canine brain was imaged using a 7-T MRI system producing 100-μm-isotropic-resolution diffusion-tensor imaging analyzed by tractography. Using regions of interest (ROIs) within cortical locations, which were confirmed by a Nissl stain that identified distinct cortical architecture, we successfully identified six important WM pathways. We also compared fractional anisotropy (FA), apparent diffusion coefficient (ADC), radial diffusivity, and axial diffusivity in tracts passing through the genu and splenium. Callosal fibers were organized on the basis of cortical destination (e.g., fibers from the genu project to the frontal cortex). Histologic results identified the motor cortex on the basis of cytoarchitectonic criteria that allowed placement of ROIs to discriminate between frontal and parietal lobes. We also identified cytoarchitecture typical of the orbital frontal, anterior frontal, and occipital regions and placed ROIs accordingly. FA, ADC, radial diffusivity, and axial diffusivity values were all higher in posterior corpus callosum fiber tracts. Using six cortical ROIs, we identified six major WM tracts that reflect major functional divisions of the cerebral hemispheres, and we derived quantitative values that can be used for study of canine models of human WM pathologic states.

A T1 and DTI fused 3D corpus callosum analysis in pre- vs. post-season contact sports players

NASA Astrophysics Data System (ADS)

Lao, Yi; Law, Meng; Shi, Jie; Gajawelli, Niharika; Haas, Lauren; Wang, Yalin; Leporé, Natasha

2015-01-01

Sports related traumatic brain injury (TBI) is a worldwide public health issue, and damage to the corpus callosum (CC) has been considered as an important indicator of TBI. However, contact sports players suffer repeated hits to the head during the course of a season even in the absence of diagnosed concussion, and less is known about their effect on callosal anatomy. In addition, T1-weighted and diffusion tensor brain magnetic resonance images (DTI) have been analyzed separately, but a joint analysis of both types of data may increase statistical power and give a more complete understanding of anatomical correlates of subclinical concussions in these athletes. Here, for the first time, we fuse T1 surface-based morphometry and a new DTI analysis on 3D surface representations of the CCs into a single statistical analysis on these subjects. Our new combined method successfully increases detection power in detecting differences between pre- vs. post-season contact sports players. Alterations are found in the ventral genu, isthmus, and splenium of CC. Our findings may inform future health assessments in contact sports players. The new method here is also the first truly multimodal diffusion and T1-weighted analysis of the CC, and may be useful to detect anatomical changes in the corpus callosum in other multimodal datasets.

Involvement of the central somatosensory system in restless legs syndrome: A neuroimaging study.

PubMed

Lee, Byeong-Yeul; Kim, Jongmyeong; Connor, James R; Podskalny, Gerald D; Ryu, Yeunchul; Yang, Qing X

2018-05-22

To investigate morphologic changes in the somatosensory cortex and the thickness of the corpus callosum subdivisions that provide interhemispheric connections between the 2 somatosensory cortical areas. Twenty-eight patients with severe restless legs syndrome (RLS) symptoms and 51 age-matched healthy controls were examined with high-resolution MRI at 3.0 tesla. The vertex-wise analysis in conjunction with a novel cortical surface classification method was performed to assess the cortical thickness across the whole-brain structures. In addition, the thickness of the midbody of the corpus callosum that links postcentral gyri in the 2 hemispheres was measured. We demonstrated that a morphologic change occurred in the brain somatosensory system in patients with RLS compared to controls. Patients with RLS exhibited a 7.5% decrease in average cortical thickness in the bilateral postcentral gyrus ( p < 0.0001). Accordingly, there was a substantial decrease in the corpus callosum posterior midbody ( p < 0.008) wherein the callosal fibers are connected to the postcentral gyrus, suggesting altered white matter properties in the somatosensory pathway. Our results provide in vivo evidence of morphologic changes in the primary somatosensory system, which could be responsible for the sensory functional symptoms of RLS. These results provide a better understanding of the pathophysiology underlying the RLS sensory symptoms and could lead to a potential imaging marker for RLS. © 2018 American Academy of Neurology.

Some glial progenitors in the neonatal subventricular zone migrate through the corpus callosum to the contralateral cerebral hemisphere.

PubMed

Kakita, Akiyoshi; Zerlin, Marielba; Takahashi, Hitoshi; Goldman, James E

2003-04-14

The great majority of glial cells of the mammalian forebrain are generated in the perinatal period from progenitors in the subventricular zone (SVZ). We investigated the migration of progenitors from the neonatal (postnatal day 0, P0) rat forebrain SVZ by labeling them in vivo with a green fluorescence protein (GFP) retrovirus and monitoring their movements by time-lapse video microscopy in P3 slices. We identified a small number of progenitors that migrated tangentially within the corpus callosum (CC) and crossed the midline. These cells retained a relatively uniform morphology: the leading process was extended toward the contralateral side but showed no process branching or turning away from the migratory direction. Net migration requires the elongation of the leading process and nuclear translocation, and the migrating cells in the CC showed both modes. We confirmed the presence of unmyelinated axon bundles within the P3 CC, but failed to detect any radially directed glial processes (vimentin- or GLAST-immunolabeled fibers) spanning through the CC. Confocal images showed a close proximity between neurofilament-immunolabeled axons and the leading process of the GFP-expressing progenitors in the CC. The destination of the callosal fibers was examined by applying DiI to the right cingulum; the labeled fibers ran throughout the CC and reached the left cingulate and motor areas. The distribution and final fates of the retrovirus-labeled cells were examined in P28 brains. A small proportion of the labeled cells were found in the contralateral hemisphere, where, as oligodendrocytes and astrocytes, they colonized predominantly the cortex and the underlying white matter of the cingulate and secondary motor areas. The distribution pattern appears to coincide well with the projection direction of the callosal fibers. Thus, glial progenitors migrate across the CC, presumably in conjunction with unmyelinated axons, to colonize the contralateral hemisphere. Copyright 2003 Wiley-Liss, Inc.

DTI-based response-driven modeling of mTLE laterality.

PubMed

Nazem-Zadeh, Mohammad-Reza; Elisevich, Kost; Air, Ellen L; Schwalb, Jason M; Divine, George; Kaur, Manpreet; Wasade, Vibhangini S; Mahmoudi, Fariborz; Shokri, Saeed; Bagher-Ebadian, Hassan; Soltanian-Zadeh, Hamid

2016-01-01

To develop lateralization models for distinguishing between unilateral and bilateral mesial temporal lobe epilepsy (mTLE) and determining laterality in cases of unilateral mTLE. mTLE is the most common form of medically refractory focal epilepsy. Many mTLE patients fail to demonstrate an unambiguous unilateral ictal onset. Intracranial EEG (icEEG) monitoring can be performed to establish whether the ictal origin is unilateral or truly bilateral with independent bitemporal ictal origin. However, because of the expense and risk of intracranial electrode placement, much research has been done to determine if the need for icEEG can be obviated with noninvasive neuroimaging methods, such as diffusion tensor imaging (DTI). Fractional anisotropy (FA) was used to quantify microstructural changes reflected in the diffusivity properties of the corpus callosum, cingulum, and fornix, in a retrospective cohort of 31 patients confirmed to have unilateral (n = 24) or bilateral (n = 7) mTLE. All unilateral mTLE patients underwent resection with an Engel class I outcome. Eleven were reported to have hippocampal sclerosis on pathological analysis; nine had undergone prior icEEG. The bilateral mTLE patients had undergone icEEG demonstrating independent epileptiform activity in both right and left hemispheres. Twenty-three nonepileptic subjects were included as controls. In cases of right mTLE, FA showed significant differences from control in all callosal subregions, in both left and right superior cingulate subregions, and in forniceal crura. Comparison of right and left mTLE cases showed significant differences in FA of callosal genu, rostral body, and splenium and the right posteroinferior and superior cingulate subregions. In cases of left mTLE, FA showed significant differences from control only in the callosal isthmus. Significant differences in FA were identified when cases of right mTLE were compared with bilateral mTLE cases in the rostral and midbody callosal subregions and isthmus. Based on 11 FA measurements in the cingulate, callosal and forniceal subregions, a response-driven lateralization model successfully differentiated all cases (n = 54) into groups of unilateral right (n = 12), unilateral left (n = 12), and bilateral mTLE (n = 7), and nonepileptic control (23). The proposed response-driven DTI biomarker is intended to lessen diagnostic ambiguity of laterality in cases of mTLE and help optimize selection of surgical candidates. Application of this model shows promise in reducing the need for invasive icEEG in prospective cases.

Pattern of callose deposition during the course of meiotic diplospory in Chondrilla juncea (Asteraceae, Cichorioideae).

PubMed

Musiał, Krystyna; Kościńska-Pająk, Maria

2017-07-01

Total absence of callose in the ovules of diplosporous species has been previously suggested. This paper is the first description of callose events in the ovules of Chondrilla juncea, which exhibits meiotic diplospory of the Taraxacum type. We found the presence of callose in the megasporocyte wall and stated that the pattern of callose deposition is dynamically changing during megasporogenesis. At the premeiotic stage, no callose was observed in the ovules. Callose appeared at the micropylar pole of the cell entering prophase of the first meioticdivision restitution but did not surround the megasporocyte. After the formation of a restitution nucleus, a conspicuous callose micropylar cap and dispersed deposits of callose were detected in the megasporocyte wall. During the formation of a diplodyad, the micropylar callose cap decreased and the walls of a newly formed megaspores showed scattered distribution of callose. Within the older diplodyad, callose was mainly accumulated in the wall between megaspores, as well as in the wall of the micropylar cell; however, a dotted fluorescence of callose was also visible in the wall of the chalazal megaspore. Gradual degradation of callose in the wall of the chalazal cell and intense callose accumulation in the wall of the micropylar cell were related to the selection of the functional megaspore. Thus, our findings may suggest that callose fulfills a similar role both during megasporogenesis in sexual angiosperms and in the course of meiotic diplospory in apomicts and seems to form a regulatory interface between reproductive and somatic cells.

Developing easy to perform routine MRI measurements as potential surrogates for cognitive impairment in MS.

PubMed

Morrow, Sarah A; Menon, Suresh; Rosehart, Heather; Sharma, Manas

2017-02-01

One of the most frequently disabling symptoms in Multiple Sclerosis (MS) is cognitive impairment which is often insidious in onset and therefore difficult to recognize in the early stages, for both persons with MS and clinicians. A biomarker that would help identify those at risk of cognitive impairment, or with only mild impairment, would be a useful tool for clinicians. Using MRI, already an integral tool in the diagnosis and monitoring of disease activity in MS, would be ideal. Thus, this study aimed to determine if simple measures on routine MRI could serve as potential biomarkers for cognitive impairment in MS. We retrospectively identified 51 persons with MS who had a cognitive assessment and MRI within six months of the MRI. Simple linear measurements of the hippocampi, bifrontral and third ventricular width, bicaudate width and the anterior, mid and posterior corpus callosum were made. Pearson's correlations examined the relationship between these MRI measures and cognitive tests, and MRI measures were compared in persons with MS who were either normal or cognitively impaired on objective cognitive tests using Analysis of Covariance (ANCOVA). Bicaudate span and third ventricular width were both negatively correlated, while corpus callosal measures were positive correlated with cognitive test performance. After controlling for potential confounders, bicaudate span was significant different on measures of immediate recall. Both anterior and posterior corpus collosal measure were significantly different on measures of verbal fluency, immediate recall and higher executive function; while the anterior corpus callosum was also significantly different on processing speed. The middle corpus collosal measure was significantly different on immediate recall and higher executive function. This study presents data demonstrating that simple to apply MRI measures of atrophy may serve as biomarkers for cognitive impairment in persons with MS. Further prospective studies are needed to validate these findings. Copyright © 2016 Elsevier B.V. All rights reserved.

Abnormal brain MRI signals in the splenium of the corpus callosum, basal ganglia and internal capsule in a suspected case with tuberculous meningitis.

PubMed

Hirotani, Makoto; Yabe, Ichiro; Hamada, Shinsuke; Tsuji, Sachiko; Kikuchi, Seiji; Sasaki, Hidenao

2007-01-01

A 34-year-old man visited the hospital with chief complaints of headache, fever, and disturbance of consciousness. In view of his clinical condition, the course of the disease, and results of examination, he was diagnosed with viral meningitis and treated accordingly. However, his clinical condition worsened, and MRI revealed abnormal signals in the splenium of the corpus callosum, in the basal ganglia and in the internal capsule, as well as the presence of severe inflammation in the base of the brain. Since he had a high ADA level in the cerebrospinal fluid and was consequently suspected to have tuberculous meningitis, he was placed on antitubercular agents. Then, his clinical condition began to improve. Additional steroid pulse therapy further improved his condition, and abnormal signals in the splenium of the corpus callosum and the basal ganglia resolved. This valuable case suggests that an immune mechanism contributed to the occurrence of central nervous system symptoms associated with tuberculous meningitis.

Deletion 1q43 encompassing only CHRM3 in a patient with autistic disorder.

PubMed

Petersen, Andrea Klunder; Ahmad, Ausaf; Shafiq, Mustafa; Brown-Kipphut, Brigette; Fong, Chin-To; Anwar Iqbal, M

2013-02-01

Deletions on the distal portion of the long arm of chromosome 1 result in complex and highly variable clinical phenotypes which include intellectual disability, autism, seizures, microcephaly/craniofacial dysmorphology, corpus callosal agenesis/hypogenesis, cardiac and genital anomalies, hand and foot abnormalities and short stature. Genotype-phenotype correlation reported a minimum region of 2 Mb at 1q43-q44. We report on a 3 ½ year old male patient diagnosed with autistic disorder who has social withdrawal, eating problems, repetitive stereotypic behaviors including self-injurious head banging and hair pulling, and no seizures, anxiety, or mood swings. Array comparative genomic hybridization (aCGH) showed an interstitial deletion of 473 kb at 1q43 region (239,412,391-239,885,394; NCBI build37/hg19) harboring only CHRM3 (Acetylcholine Receptor, Muscarinic, 3; OMIM: 118494). Recently, another case with a de novo interstitial deletion of 911 kb at 1q43 encompassing three genes including CHRM3 was reported. The M3 muscarinic receptor influences a multitude of central and peripheral nervous system processes via its interaction with acetylcholine and may be an important modulator of behavior, learning and memory. We propose CHRM3 as a candidate gene responsible for our patient's specific phenotype as well as the overlapping phenotypic features of other patients with 1q43 or 1q43-q44 deletions. Copyright © 2013. Published by Elsevier Masson SAS.

Magnetic resonance features of cerebral malaria.

PubMed

Yadav, P; Sharma, R; Kumar, S; Kumar, U

2008-06-01

Cerebral malaria is a major health hazard, with a high incidence of mortality. The disease is endemic in many developing countries, but with a greater increase in tourism, occasional cases may be detected in countries where the disease in not prevalent. Early diagnosis and evaluation of cerebral involvement in malaria utilizing modern imaging modalities have an impact on the treatment and clinical outcome. To evaluate the magnetic resonance (MR) features of patients with cerebral malaria presenting with altered sensorium. We present the findings in three patients with cerebral malaria presenting with altered sensorium. MR imaging using a 1.5-Tesla unit was carried out. The sequences performed were 5-mm-thick T1-weighted, T2-weighted, fluid-attenuated inversion-recovery (FLAIR), and T2-weighted gradient-echo axial sequences, and sagittal and coronal FLAIR. Diffusion-weighted imaging was performed with b values of 0 and 1000 s/mm(2), and apparent diffusion coefficient (ADC) maps were obtained. Focal hyperintensities in the bilateral periventricular white matter, corpus callosum, occipital subcortex, and bilateral thalami were noticed on T2-weighted and FLAIR sequences. The lesions were more marked in the splenium of the corpus callosum. No enhancement on postcontrast T1-weighted MR images was observed. There was no evidence of restricted diffusion on the diffusion-weighted sequence and ADC map. MR is a sensitive imaging modality, with a role in the assessment of cerebral lesions in malaria. Focal white matter and corpus callosal lesions without any restricted diffusion were the key findings in our patients.

Determination of stress responses induced by aluminum in maize (Zea mays).

PubMed

Vardar, Filiz; Ismailoğlu, Işil; Inan, Deniz; Unal, Meral

2011-06-01

To assess the alternative responses to aluminum toxicity, maize (Zea mays L. cv Karadeniz yıldızı) roots were exposed to different concentrations of AlCl3 (150, 300 and 450 μM). Aluminum reduced the root elongation by 39.6% in 150 μM, 44.1% in 300 μM, 50.1% in 450 μM AlCl3 after 96 h period. To correlate the root elongation with the alternative stress responses including aluminum accumulation, lipid peroxidation, mitotic abnormalities, reduction of starch content, intracellular Ca2+ accumulation, callose formation, lignin deposition and peroxidase activity, cytochemical and biochemical tests were performed. The results indicated that aluminum accumulation and lipid peroxidation were observed more densely on the root cap and the outer cortex cells. In addition to morphological deformations, cytochemical analysis displayed cellular deformations. Furthermore, mitotic abnormalities were observed such as c-mitosis, micronuclei, bi- and trinucleated cells in aluminum treated root tips. Aluminum treatment induced starch reduction, callose formation, lignin accumulation and intracellular Ca2+ increase. Moreover, the peroxidase activity increased significantly by 3, 4.4 and 7.7 times higher than in that of control after 96 h, respectively. In conclusion, aluminum is significantly stressful in maize culminating in morphological and cellular alterations.

The magnetic resonance imaging spectrum of Pelizaeus-Merzbacher disease: A multicenter study of 19 patients.

PubMed

Sumida, Kaoru; Inoue, Ken; Takanashi, Jun-Ichi; Sasaki, Masayuki; Watanabe, Kenji; Suzuki, Motomasa; Kurahashi, Hirokazu; Omata, Taku; Tanaka, Manabu; Yokochi, Kenji; Iio, Jun; Iyoda, Kuniaki; Kurokawa, Toru; Matsuo, Muneaki; Sato, Tamotu; Iwaki, Akiko; Osaka, Hitoshi; Kurosawa, Kenji; Yamamoto, Toshiyuki; Matsumoto, Naomichi; Maikusa, Norihide; Matsuda, Hiroshi; Sato, Noriko

2016-06-01

We retrospectively evaluated the imaging spectrum of Pelizaeus-Merzbacher disease (PMD) in correlation with the clinical course and genetic abnormality. We collected the magnetic resonance imaging (MRI) findings of 19 genetically proven PMD patients (all males, aged 0-29years old) using our integrated web-based MRI data collection system from 14 hospitals. The patterns of hypomyelination were determined mainly by the signals of the cerebrum, corticospinal tract, and brainstem on T2-weighted images (T2WI). We assessed the degree of myelination age on T1-weighted images (T1WI) and T2WI independently, and we evaluated cerebellar and callosal atrophy. The clinical severity and genetic abnormalities (causal mutations of the proteolipid protein gene PLP1) were analyzed together with the imaging findings. The clinical stage tended to be more severe when the whole brainstem, or corticospinal tract in the internal capsule showed abnormally high intensity on T2WI. Diffuse T2-high signal of brainstem was observed only in the patients with PLP1 point mutation. Myelination age "before birth" on T1WI is a second manifestation correlated with the clinically severe phenotypes. On the other hand, eight patients whose myelination ages were > 4months on T1WI were associated with mild clinical phenotypes. Four of them showed almost complete myelination on T1WI with a discrepancy in myelination age between T1WI and T2WI. A random and patchy pattern of myelination on T2WI was noted in one patient with PLP1 point mutation. Advanced myelination was observed in three of the seven followed-up patients. Four patients had atrophy of the cerebellum, and 17 patients had atrophy of the corpus callosum. Our multicenter study has demonstrated a wide variety of imaging findings of PMD. Signal intensity of brainstem and corticospinal tract of internal capsule would be the points to presume clinical severity in PMD patients. The spectrum of MRI findings should be kept in mind to diagnose PMD and to differentiate from other demyelinating leukodystrophies. Copyright © 2015 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.

Callosal degeneration topographically correlated with cognitive function in amnestic mild cognitive impairment and Alzheimer's disease dementia.

PubMed

Wang, Pei-Ning; Chou, Kun-Hsien; Chang, Ni-Jung; Lin, Ker-Neng; Chen, Wei-Ta; Lan, Gong-Yau; Lin, Ching-Po; Lirng, Jiing-Feng

2014-04-01

Degeneration of the corpus callosum (CC) is evident in the pathogenesis of Alzheimer's disease (AD). However, the correlation of microstructural damage in the CC on the cognitive performance of patients with amnestic mild cognitive impairment (aMCI) and AD dementia is undetermined. We enrolled 26 normal controls, 24 patients with AD dementia, and 40 single-domain aMCI patients with at least grade 1 hippocampal atrophy and isolated memory impairment. Diffusion tensor imaging (DTI) with fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (DA), and radial diffusivity (DR) were measured. The entire CC was parcellated based on fiber trajectories to specific cortical Brodmann areas using a probabilistic tractography method. The relationship between the DTI measures in the subregions of the CC and cognitive performance was examined. Although the callosal degeneration in the patients with aMCI was less extended than in the patients with AD dementia, degeneration was already exhibited in several subregions of the CC at the aMCI stage. Scores of various neuropsychological tests were correlated to the severity of microstructural changes in the subregional CC connecting to functionally corresponding cortical regions. Our results confirm that CC degeneration is noticeable as early as the aMCI stage of AD and the disconnection of the CC subregional fibers to the corresponding Brodmann areas has an apparent impact on the related cognitive performance. Copyright © 2013 Wiley Periodicals, Inc.

[Case of callosal disconnection syndrome with a chief complaint of right-hand disability, despite presence of left-hand diagonistic dyspraxia].

PubMed

Okamoto, Yoko; Saida, Hisako; Yamamoto, Toru

2009-04-01

e report the case of 48-year-old right-handed male patient with an infarction affecting most part of the body and the splenium of the left half of the corpus callosum. Neuropsychological examination revealed typical signs of callosal disconnection including left-sided apraxia, diagonistic dyspraxia, left-sided agraphia, left-hand tactile anomia, left hemialexia, and right-sided constructional disability. Moreover, he complained of impairment in activities involving the right hand disability and agraphia. He could not stop behaving with his right hand when he had a vague idea. For example, he involuntarily picked up a tea bottle with his right hand when he had a desire to drink, although the action was not appropriate to that occasion. The imitation and utilization behavior did not imply this case, because his right hand behaviors were not exaggerated in response to external stimuli, such as the gestures of the examiner or the subjects in front of the patient. Unexpectedly, he complained about impairment of the activity of his right hand and was unaware of left hand apraxia or diagonistic dyspraxia; this trend continued for 6 months, at the time of this writing. We argue that the patient may have been subconsciouly aware of the symptoms of his left hand but had not verbalized them.

Visual search and the aging brain: discerning the effects of age-related brain volume shrinkage on alertness, feature binding, and attentional control.

PubMed

Müller-Oehring, Eva M; Schulte, Tilman; Rohlfing, Torsten; Pfefferbaum, Adolf; Sullivan, Edith V

2013-01-01

Decline in visuospatial abilities with advancing age has been attributed to a demise of bottom-up and top-down functions involving sensory processing, selective attention, and executive control. These functions may be differentially affected by age-related volume shrinkage of subcortical and cortical nodes subserving the dorsal and ventral processing streams and the corpus callosum mediating interhemispheric information exchange. Fifty-five healthy adults (25-84 years) underwent structural MRI and performed a visual search task to test perceptual and attentional demands by combining feature-conjunction searches with "gestalt" grouping and attentional cueing paradigms. Poorer conjunction, but not feature, search performance was related to older age and volume shrinkage of nodes in the dorsolateral processing stream. When displays allowed perceptual grouping through distractor homogeneity, poorer conjunction-search performance correlated with smaller ventrolateral prefrontal cortical and callosal volumes. An alerting cue attenuated age effects on conjunction search, and the alertness benefit was associated with thalamic, callosal, and temporal cortex volumes. Our results indicate that older adults can capitalize on early parallel stages of visual information processing, whereas age-related limitations arise at later serial processing stages requiring self-guided selective attention and executive control. These limitations are explained in part by age-related brain volume shrinkage and can be mitigated by external cues.

Diffusion Tensor Imaging in Children with Fetal Alcohol Spectrum Disorders

PubMed Central

Wozniak, Jeffrey R.; Mueller, Bryon A.; Chang, Pi-Nian; Muetzel, Ryan L.; Caros, Lydia; Lim, Kelvin O.

2010-01-01

Background Prenatal alcohol exposure, which is associated with macrostructural brain abnormalities, neurocognitive deficits, and behavioral disturbances, is characterized as fetal alcohol syndrome (FAS) in severe cases. The only published study thus far using diffusion tensor imaging (DTI) showed microstructural abnormalities in patients with FAS. The current study investigated whether similar abnormalities are present in less severely affected, prenatally exposed patients who did not display all of the typical FAS physical stigmata. Methods Subjects included 14 children, ages 10 to 13, with fetal alcohol spectrum disorders (FASD) and 13 matched controls. Cases with full-criteria FAS, mental retardation, or microcephaly were excluded. Subjects underwent MRI scans including DTI. Results Although cases with microcephaly were excluded, there was a trend toward smaller total cerebral volume in the FASD group (p = 0.057, Cohen’s d effect size = 0.73). Subjects with FASD had greater mean diffusivity (MD) in the isthmus of the corpus callosum than controls (p = 0.013, effect size = 1.05), suggesting microstructural abnormalities in this region. There were no group differences in 5 other regions of the corpus callosum. Correlations between MD in the isthmus and facial dysmorphology were nonsignificant. Conclusions These results suggest that even relatively mild forms of fetal alcohol exposure may be associated with microstructural abnormalities in the posterior corpus callosum that are detectable with DTI. PMID:17010147

Fatty acid composition of the postmortem corpus callosum of patients with schizophrenia, bipolar disorder, or major depressive disorder.

PubMed

Hamazaki, K; Maekawa, M; Toyota, T; Dean, B; Hamazaki, T; Yoshikawa, T

2017-01-01

Studies investigating the relationship between n-3 polyunsaturated fatty acid (PUFA) levels and psychiatric disorders have thus far focused mainly on analyzing gray matter, rather than white matter, in the postmortem brain. In this study, we investigated whether PUFA levels showed abnormalities in the corpus callosum, the largest area of white matter, in the postmortem brain tissue of patients with schizophrenia, bipolar disorder, or major depressive disorder. Fatty acids in the phospholipids of the postmortem corpus callosum were evaluated by thin-layer chromatography and gas chromatography. Specimens were evaluated for patients with schizophrenia (n=15), bipolar disorder (n=15), or major depressive disorder (n=15) and compared with unaffected controls (n=15). In contrast to some previous studies, no significant differences were found in the levels of PUFAs or other fatty acids in the corpus callosum between patients and controls. A subanalysis by sex gave the same results. No significant differences were found in any PUFAs between suicide completers and non-suicide cases regardless of psychiatric disorder diagnosis. Patients with psychiatric disorders did not exhibit n-3 PUFAs deficits in the postmortem corpus callosum relative to the unaffected controls, and the corpus callosum might not be involved in abnormalities of PUFA metabolism. This area of research is still at an early stage and requires further investigation. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Shape analysis of corpus callosum in autism subtype using planar conformal mapping

NASA Astrophysics Data System (ADS)

He, Qing; Duan, Ye; Yin, Xiaotian; Gu, Xianfeng; Karsch, Kevin; Miles, Judith

2009-02-01

A number of studies have documented that autism has a neurobiological basis, but the anatomical extent of these neurobiological abnormalities is largely unknown. In this study, we aimed at analyzing highly localized shape abnormalities of the corpus callosum in a homogeneous group of autism children. Thirty patients with essential autism and twenty-four controls participated in this study. 2D contours of the corpus callosum were extracted from MR images by a semiautomatic segmentation method, and the 3D model was constructed by stacking the contours. The resulting 3D model had two openings at the ends, thus a new conformal parameterization for high genus surfaces was applied in our shape analysis work, which mapped each surface onto a planar domain. Surface matching among different individual meshes was achieved by re-triangulating each mesh according to a template surface. Statistical shape analysis was used to compare the 3D shapes point by point between patients with autism and their controls. The results revealed significant abnormalities in the anterior most and anterior body in essential autism group.

Altered white matter integrity and development in children with autism: a combined voxel-based morphometry and diffusion imaging study.

PubMed

Mengotti, Paola; D'Agostini, Serena; Terlevic, Robert; De Colle, Cristina; Biasizzo, Elsa; Londero, Danielle; Ferro, Adele; Rambaldelli, Gianluca; Balestrieri, Matteo; Zanini, Sergio; Fabbro, Franco; Molteni, Massimo; Brambilla, Paolo

2011-02-01

A combined protocol of voxel-based morphometry (VBM) and diffusion-weighted imaging (DWI) was applied to investigate the neurodevelopment of gray and white matter in autism. Twenty children with autism (mean age= 7 ± 2.75 years old; age range: 4-14; 2 girls) and 22 matched normally developing children (mean age = 7.68 ± 2.03 years old; age range: 4-11; 2 girls) underwent magnetic resonance imaging (MRI). VBM was employed by applying the Template-o-Matic toolbox (TOM), a new approach which constructs the age-matched customized template for tissue segmentation. Also, the apparent diffusion coefficients (ADC) of water molecules were obtained from the analysis of DWI. Regions of interests (ROIs), standardized at 5 pixels, were placed in cortical lobes and corpus callosum on the non-diffusion weighted echo-planar images (b = 0) and were then automatically transferred to the corresponding maps to obtain the ADC values. Compared to normal children, individuals with autism had significantly: (1) increased white matter volumes in the right inferior frontal gyrus, the right fusiform gyrus, the left precentral and supplementary motor area and the left hippocampus, (2) increased gray matter volumes in the inferior temporal gyri bilaterally, the right inferior parietal cortex, the right superior occipital lobe and the left superior parietal lobule, and (3) decreased gray matter volumes in the right inferior frontal gyrus and the left supplementary motor area. Abnormally increased ADC values in the bilateral frontal cortex and in the left side of the genu of the corpus callosum were also reported in autism. Finally, age correlated negatively with lobar and callosal ADC measurements in individuals with autism, but not in children with normal development. These findings suggest cerebral dysconnectivity in the early phases of autism coupled with an altered white matter maturation trajectory during childhood potentially taking place in the frontal and parietal lobes, which may represent a neurodevelopmental marker of the disorder, possibly accounting for the cognitive and social deficits. Copyright © 2010 Elsevier Inc. All rights reserved.

Aicardi's syndrome: (agenesis of the corpus callosum, infantile spasms, and ocular anomalies).

PubMed

Dinani, S; Jancar, J

1984-06-01

A case of Aicardi's syndrome is reported. A 12-year-old mentally handicapped female has all the characteristics of the syndrome: agenesis of the Corpus callosum; female infant with mental handicap, epilepsy, characteristic eye lesions, vertebral anomalies and abnormal EEG pattern. The results of supporting examination and investigations are noted.

Distribution of Callose Synthase, Cellulose Synthase, and Sucrose Synthase in Tobacco Pollen Tube Is Controlled in Dissimilar Ways by Actin Filaments and Microtubules1[W

PubMed Central

Cai, Giampiero; Faleri, Claudia; Del Casino, Cecilia; Emons, Anne Mie C.; Cresti, Mauro

2011-01-01

Callose and cellulose are fundamental components of the cell wall of pollen tubes and are probably synthesized by distinct enzymes, callose synthase and cellulose synthase, respectively. We examined the distribution of callose synthase and cellulose synthase in tobacco (Nicotiana tabacum) pollen tubes in relation to the dynamics of actin filaments, microtubules, and the endomembrane system using specific antibodies to highly conserved peptide sequences. The role of the cytoskeleton and membrane flow was investigated using specific inhibitors (latrunculin B, 2,3-butanedione monoxime, taxol, oryzalin, and brefeldin A). Both enzymes are associated with the plasma membrane, but cellulose synthase is present along the entire length of pollen tubes (with a higher concentration at the apex) while callose synthase is located in the apex and in distal regions. In longer pollen tubes, callose synthase accumulates consistently around callose plugs, indicating its involvement in plug synthesis. Actin filaments and endomembrane dynamics are critical for the distribution of callose synthase and cellulose synthase, showing that enzymes are transported through Golgi bodies and/or vesicles moving along actin filaments. Conversely, microtubules appear to be critical in the positioning of callose synthase in distal regions and around callose plugs. In contrast, cellulose synthases are only partially coaligned with cortical microtubules and unrelated to callose plugs. Callose synthase also comigrates with tubulin by Blue Native-polyacrylamide gel electrophoresis. Membrane sucrose synthase, which expectedly provides UDP-glucose to callose synthase and cellulose synthase, binds to actin filaments depending on sucrose concentration; its distribution is dependent on the actin cytoskeleton and the endomembrane system but not on microtubules. PMID:21205616

[Callose accumulation during treatment of tomato (Lycopersicon esculentum L.) cells with biotic elicitors].

PubMed

Emel'ianov, V I; Kravchuk, Zh N; Poliakovskiĭ, S A; Dmitriev, A P

2008-01-01

Time-course of induced accumulation of callose in tomato cells has been studied. Localization of callose in L. esculenthum cells was investigated by fluorescent microscopy technique, and the optimal time for its determination was found. Callose accumulation in tomato cells treated with different biotic elicitors was determined. Nonlinear dependence between callose accumulation and concentration of chitin oligomers (with 3-5 N-acetylglucosamine fragments) was established. Increasing of callose accumulation in tomato cells was proportional to the increase of concentration ofchitin dimer and chitosan in the culture medium.

Callose biosynthesis in Arabidopsis with a focus on pathogen response: what we have learned within the last decade.

PubMed

Ellinger, Dorothea; Voigt, Christian A

2014-10-01

(1,3)-β-Glucan callose is a cell wall polymer that is involved in several fundamental biological processes, ranging from plant development to the response to abiotic and biotic stresses. Despite its importance in maintaining plant integrity and plant defence, knowledge about the regulation of callose biosynthesis at its diverse sites of action within the plant is still limited. The moderately sized family of GSL (GLUCAN SYNTHASE-LIKE) genes is predicted to encode callose synthases with a specific biological function and subcellular localization. Phosphorylation and directed translocation of callose synthases seem to be key post-translational mechanisms of enzymatic regulation, whereas transcriptional control of GSL genes might only have a minor function in response to biotic or abiotic stresses. Among the different sites of callose biosynthesis within the plant, particular attention has been focused on the formation of callose in response to pathogen attack. Here, callose is deposited between the plasma membrane and the cell wall to act as a physical barrier to stop or slow invading pathogens. Arabidopsis (Arabidopsis thaliana) is one of the best-studied models not only for general plant defence responses but also for the regulation of pathogen-induced callose biosynthesis. Callose synthase GSL5 (GLUCAN SYNTHASE-LIKE5) has been shown to be responsible for stress-induced callose deposition. Within the last decade of research into stress-induced callose, growing evidence has been found that the timing of callose deposition in the multilayered system of plant defence responses could be the key parameter for optimal effectiveness. This timing seems to be achieved through co-ordinated transport and formation of the callose synthase complex. © The Author 2014. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Differences in Callosal and Forniceal Diffusion between Patients with and without Postconcussive Migraine.

PubMed

Alhilali, L M; Delic, J; Fakhran, S

2017-04-01

Posttraumatic migraines are common after mild traumatic brain injury. The purpose of this study was to determine if a specific axonal injury pattern underlies posttraumatic migraines after mild traumatic brain injury utilizing Tract-Based Spatial Statistics analysis of diffusion tensor imaging. DTI was performed in 58 patients with mild traumatic brain injury with posttraumatic migraines. Controls consisted of 17 patients with mild traumatic brain injury without posttraumatic migraines. Fractional anisotropy and diffusivity maps were generated to measure white matter integrity and were evaluated by using Tract-Based Spatial Statistics regression analysis with a general linear model. DTI findings were correlated with symptom severity, neurocognitive test scores, and time to recovery with the Pearson correlation coefficient. Patients with mild traumatic brain injury with posttraumatic migraines were not significantly different from controls in terms of age, sex, type of injury, or neurocognitive test performance. Patients with posttraumatic migraines had higher initial symptom severity ( P = .01) than controls. Compared with controls, patients with mild traumatic brain injury with posttraumatic migraines had decreased fractional anisotropy in the corpus callosum ( P = .03) and fornix/septohippocampal circuit ( P = .045). Injury to the fornix/septohippocampal circuit correlated with decreased visual memory ( r = 0.325, P = .01). Injury to corpus callosum trended toward inverse correlation with recovery ( r = -0.260, P = .05). Injuries to the corpus callosum and fornix/septohippocampal circuit were seen in patients with mild traumatic brain injury with posttraumatic migraines, with injuries in the fornix/septohippocampal circuit correlating with decreased performance on neurocognitive testing. © 2017 by American Journal of Neuroradiology.

[Behavioral and cognitive profile of corpus callosum agenesia - Review].

PubMed

Lábadi, Beatrix; Beke, Anna Maria

2016-11-30

Agenesis of corpus callosum is a relatively frequent congenital cerebral malformation including dysplasia, total or partial absence of corpus callosum. The agenesis of corpus callosum can be occured in isolated form without accompanying somatic or central nervous system abnormalities and it can be associated with other central nervus system malformations. The behavioral and cognitive outcome is more favorable for patients with isolated agenesis of corpus callous than syndromic form of corpus callosum. The aim of this study is to review recent research on behavioral and social-cognitive functions in individuals with agenesis of corpus callosum. Developmental delay is common especially in higher-order cognitive and social functions. An internet database search was performed to identify publications on the subject. Fifty-five publications in English corresponded to the criteria. These studies reported deficits in language, social cognition and emotions in individuals with agenesis of corpus callosum which is known as primary corpus callous syndrome. The results indicate that individuals with agenesis of corpus callosum have deficiency in social-cognitive domain (recognition of emotions, weakness in paralinguistic aspects of language and mentalizing abilities). The impaired social cognition can be manifested in behavioral problems like autism and attention deficit hyperactivity disorder.

Abnormal Corpus Callosum Connectivity, Socio-Communicative Deficits, and Motor Deficits in Children with Autism Spectrum Disorder: A Diffusion Tensor Imaging Study

ERIC Educational Resources Information Center

Hanaie, Ryuzo; Mohri, Ikuko; Kagitani-Shimono, Kuriko; Tachibana, Masaya; Matsuzaki, Junko; Watanabe, Yoshiyuki; Fujita, Norihiko; Taniike, Masako

2014-01-01

In addition to social and communicative deficits, many studies have reported motor deficits in autism spectrum disorder (ASD). This study investigated the macro and microstructural properties of the corpus callosum (CC) of 18 children with ASD and 12 typically developing controls using diffusion tensor imaging tractography. We aimed to explore…

Quantitative Analysis of the Shape of the Corpus Callosum in Patients with Autism and Comparison Individuals

ERIC Educational Resources Information Center

Casanova, Manuel F.; El-Baz, Ayman; Elnakib, Ahmed; Switala, Andrew E.; Williams, Emily L.; Williams, Diane L.; Minshew, Nancy J.; Conturo, Thomas E.

2011-01-01

Multiple studies suggest that the corpus callosum in patients with autism is reduced in size. This study attempts to elucidate the nature of this morphometric abnormality by analyzing the shape of this structure in 17 high-functioning patients with autism and an equal number of comparison participants matched for age, sex, IQ, and handedness. The…

Callose deposition during gravitropism of Zea mays and Pisum sativum and its inhibition by 2-deoxy-D-glucose

NASA Technical Reports Server (NTRS)

Jaffe, M. J.; Leopold, A. C.

1984-01-01

In etiolated corn (Zea mays L.) and etiolated pea (Pisum sativum L.) seedlings, a gravitropic stimulation induces the deposition of callose. In the corn coleoptiles this occurs within 5 min of gravity stimulation, and prior to the beginning of curvature. Both gravitropic curvature and callose deposition reach their maxima by 12 h. Within the first 2 h more callose is deposited on the upper (concave) side, but after 2-3 h, this deposition pattern is reversed. An inhibitor of protein glycosylation, 2-deoxy-D-glucose (DDG), inhibits callose production and considerably retards gravitropic bending in both species of plants. Mannose can relieve the inhibition of gravitropic bending by DDG. The pea mutant "Ageotropum", which does not respond to gravity when etiolated, also fails to produce callose in response to a gravitic stimulus. These correlations indicate that callose deposition may be a biochemical component of gravitropism in plant shoots.

Unplugging the callose plug from sieve pores.

PubMed

Xie, Bo; Hong, Zonglie

2011-04-01

The presence of callose in sieve plates has been known for a long time, but how this polysaccharide plug is synthesized has remained unsolved. Two independent laboratories have recently reported the identification of callose synthase 7 (CalS7), also known as glucan synthase-like 7 (GSL7), as the enzyme responsible for callose deposition in sieve plates. Mutant plants defective in this enzyme failed to synthesize callose in developing sieve plates during phloem formation and were unable to accumulate callose in sieve pores in response to stress treatments. The mutant plants developed less open pores per sieve plate and the pores were smaller in diameter. As a result, phloem conductivity was reduced significantly and the mutant plants were shorter and set fewer seeds.

Unplugging the callose plug from sieve pores

PubMed Central

Xie, Bo

2011-01-01

The presence of callose in sieve plates has been known for a long time, but how this polysaccharide plug is synthesized has remained unsolved. Two independent laboratories have recently reported the identification of callose synthase 7 (CalS7), also known as glucan synthase-like 7 (GSL7), as the enzyme responsible for callose deposition in sieve plates. Mutant plants defective in this enzyme failed to synthesize callose in developing sieve plates during phloem formation and were unable to accumulate callose in sieve pores in response to stress treatments. The mutant plants developed less open pores per sieve plate and the pores were smaller in diameter. As a result, phloem conductivity was reduced significantly and the mutant plants were shorter and set fewer seeds. PMID:21386663

Human Cytomegalovirus IE2 Protein Disturbs Brain Development by the Dysregulation of Neural Stem Cell Maintenance and the Polarization of Migrating Neurons.

PubMed

Han, Dasol; Byun, Sung-Hyun; Kim, Juwan; Kwon, Mookwang; Pleasure, Samuel J; Ahn, Jin-Hyun; Yoon, Keejung

2017-09-01

Despite the high incidence of severe defects in the central nervous system caused by human cytomegalovirus (HCMV) congenital infection, the mechanism of HCMV neuropathogenesis and the roles of individual viral genes have not yet been fully determined. In this study, we show that the immediate-early 2 (IE2) protein may play a key role in HCMV-caused neurodevelopmental disorders. IE2-transduced neural progenitor cells gave rise to neurospheres with a lower frequency and produced smaller neurospheres than control cells in vitro , indicating reduction of self-renewal and expansion of neural progenitors by IE2. At 2 days after in utero electroporation into the ventricle of the developing brain, a dramatically lower percentage of IE2-expressing cells was detected in the ventricular zone (VZ) and cortical plate (CP) compared to control cells, suggesting that IE2 concurrently dysregulates neural stem cell maintenance in the VZ and neuronal migration to the CP. In addition, most IE2 + cells in the lower intermediate zone either showed multipolar morphology with short neurites or possessed nonradially oriented processes, whereas control cells had long, radially oriented monopolar or bipolar neurites. IE2 + callosal axons also failed to cross the midline to form the corpus callosum. Furthermore, we provide molecular evidence that the cell cycle arrest and DNA binding activities of IE2 appear to be responsible for the increased neural stem cell exit from the VZ and cortical migrational defects, respectively. Collectively, our results demonstrate that IE2 disrupts the orderly process of brain development in a stepwise manner to further our understanding of neurodevelopmental HCMV pathogenesis. IMPORTANCE HCMV brain pathogenesis has been studied in limited experimental settings, such as in vitro HCMV infection of neural progenitor cells or in vivo murine CMV infection of the mouse brain. Here, we show that IE2 is a pivotal factor that contributes to HCMV-induced abnormalities in the context of the embryonic brain using an in utero gene transfer tool. Surprisingly, IE2, but not HCMV IE1 or murine CMV ie3, interferes pleiotropically with key neurodevelopmental processes, including neural stem cell regulation, proper positioning of migrating neurons, and the callosal axon projections important for communication between the hemispheres. Our data suggest that the wide spectrum of clinical outcomes, ranging from mental retardation to microcephaly, caused by congenital HCMV infection can be sufficiently explained in terms of IE2 action alone. Copyright © 2017 American Society for Microbiology.

The role of white matter abnormalities in treatment-resistant depression: a systematic review.

PubMed

Serafini, Gianluca; Pompili, Maurizio; Borgwardt, Stefan; Giuffra, Enrico; Howes, Oliver; Girardi, Paolo; Amore, Mario

2015-01-01

Patients with treatment-resistant depression (TRD) commonly report significant disability together with an increased risk of functional impairment. Neuroimaging techniques have been used to investigate the neuropathology of this complex illness, but it is still quite unknown whether abnormalities in the integrity of white matter (WM) of specific brain areas may be considered as trait markers of TRD. Electronic databases were searched from 1980 to 2013. Nine studies - comprising a total of 228 subjects and 171 controls - fulfilled our inclusion criteria and were analyzed in the present overview. Several cross-sectional studies showed the association between WM abnormalities and TRD. According to the selected studies, sub-callosal cingulated cortex (SCC) WM abnormalities were largely implicated in the pathogenesis of both major depressive disorder and TRD. However, alterations in cortical-limbic or cortical-subcortical circuits, particularly the left middle frontal gyrus (which is thought to have a major role in emotional regulation) may also be involved in the pathophysiology of TRD. TRD may be related to the presence of specific microstructural WM abnormalities. WM abnormalities of specific brain regions such as SCC may have a major involvement in the pathogenesis of TRD.

Functional expansion of sensorimotor representation and structural reorganization of callosal connections in lower limb amputees.

PubMed

Simões, Elington L; Bramati, Ivanei; Rodrigues, Erika; Franzoi, Ana; Moll, Jorge; Lent, Roberto; Tovar-Moll, Fernanda

2012-02-29

Previous studies have indicated that amputation or deafferentation of a limb induces functional changes in sensory (S1) and motor (M1) cortices, related to phantom limb pain. However, the extent of cortical reorganization after lower limb amputation in patients with nonpainful phantom phenomena remains uncertain. In this study, we combined functional magnetic resonance (fMRI) and diffusion tensor imaging (DTI) to investigate the existence and extent of cortical and callosal plasticity in these subjects. Nine "painless" patients with lower limb amputation and nine control subjects (sex- and age-matched) underwent a 3-T MRI protocol, including fMRI with somatosensory stimulation. In amputees, we observed an expansion of activation maps of the stump in S1 and M1 of the deafferented hemisphere, spreading to neighboring regions that represent the trunk and upper limbs. We also observed that tactile stimulation of the intact foot in amputees induced a greater activation of ipsilateral S1, when compared with controls. These results demonstrate a functional remapping of S1 in lower limb amputees. However, in contrast to previous studies, these neuroplastic changes do not appear to be dependent on phantom pain but do also occur in those who reported only the presence of phantom sensation without pain. In addition, our findings indicate that amputation of a limb also induces changes in the cortical representation of the intact limb. Finally, DTI analysis showed structural changes in the corpus callosum of amputees, compatible with the hypothesis that phantom sensations may depend on inhibitory release in the sensorimotor cortex.

Tetrad pollen formation in Annona (Annonaceae): proexine formation andbinding mechanism.

PubMed

Tsou, Chih-Hua; Fu, Yu-Lan

2002-05-01

Meiotic tetrads of Annona glabra and A. montana build up a well-developed proexine (protectum, probaculum, and pronexine) at the proximal side but only a thin pronexine at the distal side during the tetrad stage. The callosic envelope is only partially digested by the end of tetrad stage. The remaining, undigested part is composed of the intersporal mass and thin peripheral layers, and the latter is conjunct with the distal pronexine of the microspore. In this remaining callosic structure celluloses are also present. Later on, due to the continuous slow decomposition of this callose-cellulose structure and microspore expansion, microspores break up the callose-cellulose envelope. Because all the four microspores are bound together by the callose-cellulose structure, they move out of the chamber in rotation. Eventually the thin pronexine is pulled toward the center of the tetrad and the well-developed proexine becomes the distal wall. These descriptions of the partial digestion of callosic envelope, the transformation from a callose-cellulose structure to the binding system of tetrad pollen, and microspore rotation in Annona are unusual in the angiosperms.

Regional Brain Biometrics at Term-Equivalent Age and Developmental Outcome in Extremely Low-Birth-Weight Infants.

PubMed

Melbourne, Launice; Murnick, Jonathan; Chang, Taeun; Glass, Penny; Massaro, An N

2015-10-01

This study aims to evaluate individual regional brain biometrics and their association with developmental outcome in extremely low-birth-weight (ELBW) infants. This is a retrospective study evaluating term-equivalent magnetic resonance imaging (TE-MRI) from 27 ELBW infants with known developmental outcomes beyond 12 months corrected age. Regional biometric measurements were performed by a pediatric neuroradiologist blinded to outcome data. Measures included biparietal width, transcerebellar diameter (TCD), deep gray matter area (DGMA), ventricular dilatation, corpus callosum, and interhemispheric distance. The relationship between regional biometrics and Bayley-II developmental scores were evaluated with linear regression models. The study cohort had an average±standard deviation birth weight of 684±150 g, gestational age of 24.6±2 weeks and 48% males. DGMA was significantly associated with both cognitive and motor outcomes. Significant associations were also observed between TCD and corpus callosum splenium with cognitive and motor outcomes, respectively. Other biometric measures were not associated with outcome (p>0.05). DGMA<10.26 cm2 was highly specific for poor motor and cognitive outcome. TE-MRI biometrics reflecting impaired deep gray matter, callosal, and cerebellar size is associated with worse early childhood cognitive and motor outcomes. DGMA may be the most robust single biometric measure to predict adverse developmental outcome in preterm survivors. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Elevated Early Callose Deposition Results in Complete Penetration Resistance to Powdery Mildew in Arabidopsis1[C][W][OA

PubMed Central

Ellinger, Dorothea; Naumann, Marcel; Falter, Christian; Zwikowics, Claudia; Jamrow, Torsten; Manisseri, Chithra; Somerville, Shauna C.; Voigt, Christian A.

2013-01-01

A common response by plants to fungal attack is deposition of callose, a (1,3)-β-glucan polymer, in the form of cell wall thickenings called papillae, at site of wall penetration. While it has been generally believed that the papillae provide a structural barrier to slow fungal penetration, this idea has been challenged in recent studies of Arabidopsis (Arabidopsis thaliana), where fungal resistance was found to be independent of callose deposition. To the contrary, we show that callose can strongly support penetration resistance when deposited in elevated amounts at early time points of infection. We generated transgenic Arabidopsis lines that express POWDERY MILDEW RESISTANT4 (PMR4), which encodes a stress-induced callose synthase, under the control of the constitutive 35S promoter. In these lines, we detected callose synthase activity that was four times higher than that in wild-type plants 6 h post inoculation with the virulent powdery mildew Golovinomyces cichoracearum. The callose synthase activity was correlated with enlarged callose deposits and the focal accumulation of green fluorescent protein-tagged PMR4 at sites of attempted fungal penetration. We observed similar results from infection studies with the nonadapted powdery mildew Blumeria graminis f. sp. hordei. Haustoria formation was prevented in resistant transgenic lines during both types of powdery mildew infection, and neither the salicylic acid-dependent nor jasmonate-dependent pathways were induced. We present a schematic model that highlights the differences in callose deposition between the resistant transgenic lines and the susceptible wild-type plants during compatible and incompatible interactions between Arabidopsis and powdery mildew. PMID:23335625

Studies on callose and cutin during the expression of competence and determination for organogenic nodule formation from internodes of Humulus lupulus var. Nugget.

PubMed

Fortes, Ana M; Testillano, Pilar S; Del Carmen Risueño, Maria; Pais, Maria S

2002-09-01

Callose and cutin deposition were followed by staining with Aniline Blue and Nile Red and by immunolocalization using antibodies raised against callose. Along with morphogenesis induction from internodes of Humulus lupulus var. Nugget, a temporal and spatial differential deposition of callose and cutin was observed. A cutin layer showing bright yellow autofluorescence appears, surrounding cells or groups of cells committed to express morphogenic competence. This cutin layer that evolves to a randomly organized network appeared underneath a callose layer and may create a specific cellular environment with altered permeability and altered receptors providing conditions for entering the cell cycle. The incipient callose accumulation in control explants cultured on basal medium suggests the involvement of callose in the initiation of the morphogenic programme leading to nodule formation. A scanning electron microscopic study during the organogenic process showed that before shoot bud regeneration, the cutin layer increases in thickness and acquires a smooth texture. This cutin layer is specific to nodular organogenic regions and disappeared with plantlet regeneration. This layer may control permeability to water and solute transfer throughout plantlet regeneration.

Localization and Quantification of Callose in the Streptophyte Green Algae Zygnema and Klebsormidium: Correlation with Desiccation Tolerance

PubMed Central

Herburger, Klaus; Holzinger, Andreas

2015-01-01

Freshwater green algae started to colonize terrestrial habitats about 460 million years ago, giving rise to the evolution of land plants. Today, several streptophyte green algae occur in aero-terrestrial habitats with unpredictable fluctuations in water availability, serving as ideal models for investigating desiccation tolerance. We tested the hypothesis that callose, a β-d-1,3-glucan, is incorporated specifically in strained areas of the cell wall due to cellular water loss, implicating a contribution to desiccation tolerance. In the early diverging genus Klebsormidium, callose was drastically increased already after 30 min of desiccation stress. Localization studies demonstrated an increase in callose in the undulating cross cell walls during cellular water loss, allowing a regulated shrinkage and expansion after rehydration. This correlates with a high desiccation tolerance demonstrated by a full recovery of the photosynthetic yield visualized at the subcellular level by Imaging-PAM. Furthermore, abundant callose in terminal cell walls might facilitate cell detachment to release dispersal units. In contrast, in the late diverging Zygnema, the callose content did not change upon desiccation for up to 3.5 h and was primarily localized in the corners between individual cells and at terminal cells. While these callose deposits still imply reduction of mechanical damage, the photosynthetic yield did not recover fully in the investigated young cultures of Zygnema upon rehydration. The abundance and specific localization of callose correlates with the higher desiccation tolerance in Klebsormidium when compared with Zygnema. PMID:26412780

Prenatal and postnatal evaluation of polymicrogyria with band heterotopia.

PubMed

Nagaraj, Usha D; Hopkin, Robert; Schapiro, Mark; Kline-Fath, Beth

2017-09-01

The coexistence of band heterotopia and polymicrogyria is extremely rare though it has been reported in the presence of corpus callosum anomalies and megalencephaly. We present prenatal and postnatal MRI findings of a rare case of diffuse cortical malformation characterized by polymicrogyria and band heterotopia. Agenesis of the corpus callosum and megalencephaly were also noted. In addition, bilateral closed-lip schizencephaly was identified on postnatal MRI, which has not been previously reported with this combination of imaging findings. Polymicrogyria with band heterotopia can occur and can be diagnosed with fetal MRI. The coexistence of corpus callosum anomalies and megalencephaly comprises a rare phenotype that has been previously described, suggesting an underlying genetic abnormality.

Topographic organization, number, and laminar distribution of callosal cells connecting visual cortical areas 17 and 18 of normally pigmented and Siamese cats.

PubMed

Berman, N E; Grant, S

1992-07-01

The callosal connections between visual cortical areas 17 and 18 in adult normally pigmented and "Boston" Siamese cats were studied using degeneration methods, and by transport of WGA-HRP combined with electrophysiological mapping. In normal cats, over 90% of callosal neurons were located in the supragranular layers. The supragranular callosal cell zone spanned the area 17/18 border and extended, on average, some 2-3 mm into both areas to occupy a territory which was roughly co-extensive with the distribution of callosal terminations in these areas. The region of the visual field adjoining the vertical meridian that was represented by neurons in the supragranular callosal cell zone was shown to increase systematically with decreasing visual elevation. Thus, close to the area centralis, receptive-field centers recorded from within this zone extended only up to 5 deg into the contralateral hemifield but at elevations of -10 deg and -40 deg they extended as far as 8 deg and 14 deg, respectively, into this hemifield. This suggests an element of visual non-correspondence in the callosal pathway between these cortical areas, which may be an essential substrate for "coarse" stereopsis at the visual midline. In the Siamese cats, the callosal cell and termination zones in areas 17 and 18 were expanded in width compared to the normal animals, but the major components were less robust. The area 17/18 border was often devoid of callosal axons and, in particular, the number of supragranular layer neurons participating in the pathway were drastically reduced, to only about 25% of those found in the normally pigmented adults. The callosal zones contained representations of the contralateral and ipsilateral hemifields that were roughly mirror-symmetric about the vertical meridian, and both hemifield representations increased with decreasing visual elevation. The extent and severity of the anomalies observed were similar across individual cats, regardless of whether a strabismus was also present. The callosal pathway between these visual cortical areas in the Siamese cat has been considered "silent," since nearly all neurons within its territory are activated only by the contralateral eye. The paucity of supragranular pyramidal neurons involved in the pathway may explain this silence.

Ophthalmologic abnormalities in Mowat-Wilson syndrome and a mutation in ZEB2.

PubMed

Ariss, Michelle; Natan, Kristina; Friedman, Neil; Traboulsi, Elias I

2012-09-01

Mowat-Wilson syndrome is a genetic disorder characterized by a distinct facial appearance, moderate-to-severe mental retardation, microcephaly, agenesis of the corpus callosum, Hirschsprung disease, congenital heart disease, and genital anomalies. Ophthalmological abnormalities have been rarely described in patients with this condition which is caused by mutations in the ZEB2 gene. We report a 9-year-old female with this syndrome who has severe ocular abnormalities including bilateral microphthalmia, cataract, and retinal aplasia.

Magnetic resonance imaging (MRI) findings among children with fetal alcohol syndrome (FAS), partial fetal alcohol syndrome (pFAS) and alcohol related neurodevelopmental disorders (ARND).

PubMed

Anna Dyląg, Katarzyna; Sikora-Sporek, Aleksanda; Bańdo, Bożena; Boroń-Zyss, Joanna; Drożdż, Dorota; Dumnicka, Paulina; Przybyszewska, Katarzyna; Sporek, Mateusz; Walocha, Jerzy W; Wojciechowski, Wadim; Urbanik, Andrzej

The aim of the study was to analyze the findings in MRI (magnetic resonance imaging) of the brain amongst children diagnosed with fetal alcohol syndrome (FAS), partial fetal alcohol syndrome (pFAS) or alcohol related neurodevelopmental disorders (ARND). The issue has been studied in several researches previously but the experts agree that there is still few data on the MRI results in the group of younger children. MRI results of 121 patients with either FAS or pFAS or ARND diagnosed with Canadian criteria were analyzed regarding the presence of abnormalities. The group consisted of 71 patients diagnosed with FAS, 33 diagnosed with pFAS and 17 diagnosed with ARND. The mean age of the patients was 8.03 years (standard deviation 4.07). In the total group of FASD patients 61.98% of the patients’ MRI results were abnormal. The most common abnormality in MRI of the patients were demyelination plaques (incidence 23.1%) and corpus callosum narrowing (20.7%) as well as ventricular asymmetry (18.8%).The demyelination plaques and corpus callosum narrowing were more frequent among children ≤4 years old (41.7% vs 18.6%; p=0.016 and 50.0% vs.13.4%; p<0.001, respectively). Age ≤4 years predicted the presence of demyelination plaques and corpus callosum narrowing independently of FAS diagnosis. Among younger children, multiple central nervous system abnormalities were observed more often than in the older age group (54.2% vs. 14.4%; p<0.001). Odds ratio for multiple changes was 0.84 per one-year increase in age (95% CI 0.73-0.97), p=0.016. Furthermore, in the analysis according to the specific diagnosis, among the patients diagnosed with FAS, multiple anomalies were more common than in pFAS and ARND. Both age ≤4 years and FAS diagnosis were independent predictors for multiple anomalies in multiple logistic regression. In structural brain MRI of younger children, multiple anomalies were found more frequently than among older children. Demyelination plaques and corpus callosum narrowing were more common in younger FASD patients than in older ones.

D-(/sup 3/H)aspartate retrograde labelling of callosal and association neurons of somatosensory areas I and II of cats

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

Barbaresi, P.; Fabri, M.; Conti, F.

Experiments were carried out on cats to ascertain whether corticocortical neurons of somatosensory areas I (SI) and II (SII) could be labelled by retrograde axonal transport of D-(/sup 3/H)aspartate (D-(/sup 3/H)Asp). This tritiated enantiomer of the amino acid aspartate is (1) taken up selectively by axon terminals of neurons releasing aspartate and/or glutamate as excitatory neurotransmitter, (2) retrogradely transported and accumulated in perikarya, (3) not metabolized, and (4) visualized by autoradiography. A solution of D-(/sup 3/H)Asp was injected in eight cats in the trunk and forelimb zones of SI (two cats) or in the forelimb zone of SII (six cats).more » In order to compare the labelling patterns obtained with D-(/sup 3/H)Asp with those resulting after injection of a nonselective neuronal tracer, horseradish peroxidase (HRP) was delivered mixed with the radioactive tracer in seven of the eight cats. Furthermore, six additional animals received HRP injections in SI (three cats; trunk and forelimb zones) or SII (three cats; forelimb zone). D-(/sup 3/H)Asp retrograde labelling of perikarya was absent from the ipsilateral thalamus of all cats injected with the radioactive tracer but a dense terminal plexus of anterogradely labelled corticothalamic fibers from SI and SII was observed, overlapping the distribution area of thalamocortical neurons retrogradely labelled with HRP from the same areas. D-(/sup 3/H)Asp-labelled neurones were present in ipsilateral SII (SII-SI association neurones) in cats injected in SI. In these animals a bundle of radioactive fibres was observed in the rostral portion of the corpus callosum entering the contralateral hemisphere. There, neurones retrogradely labelled with silver grains were present in SI (SI-SI callosal neurons).« less

The roles of callose, elicitors and ethylene in thigmomorphogenesis and gravitropism

NASA Technical Reports Server (NTRS)

Jaffe, M. J.

1984-01-01

A correlation (both temporal and through the inhibitor, 2-deoxy-D-glucose) of callose deposition and ethylene evolution in mechanically perturbed (MP) bean or pine stems or in gravitationally stimulated corn shoots was demonstrated. It was suggested that the callose, which is deposited on the inside of the cell wall, and adjacent to the plasma membrane causes, in some way, the ethylene production. A hypothesis explaining the mechanism is discussed which states that there is a chemical activation of the enzyme system by the callose which is being deposited in apposition with it. Experimental data supporting the hypothesis are presented.

Proverb comprehension in individuals with agenesis of the corpus callosum.

PubMed

Rehmel, Jamie L; Brown, Warren S; Paul, Lynn K

2016-09-01

Comprehension of non-literal language involves multiple neural systems likely involving callosal connections. We describe proverb comprehension impairments in individuals with isolated agenesis of the corpus callosum (AgCC) and normal-range general intelligence. Experiment 1 compared Gorham Proverb Test (Gorham, 1956) performance in 19 adults with AgCC and 33 neurotypical control participants of similar age, sex, and intelligence. Experiment 2 used the Proverbs subtest of the Delis-Kaplan Executive Function System (D-KEFS, 2001) to compare 19 adults with AgCC and 17 control participants with similar age, sex, and intelligence. Gorham Proverbs performance was impaired in the AgCC group for both the free-response and multiple-choice tasks. On the D-KEFS proverbs test, the AgCC group performed significantly worse on the free-response task (and all derivative scores) despite normal levels of performance on the multiple-choice task. Covarying verbal intelligence did not alter these outcomes. However, covarying a measure of non-literal language comprehension considerably reduced group differences in proverb comprehension on the Gorham test, but had little effect on the D-KEFS group differences. The difference between groups seemed to be greatest when participants had to generate their own interpretation (free response), or in the multiple choice format when the test included many proverbs that were likely to be less familiar. Taken together, the results of this study clearly show that proverb comprehension is diminished in individuals with AgCC compared to their peers. Copyright © 2016 Elsevier Inc. All rights reserved.

Perinatal exposure to music protects spatial memory against callosal lesions.

PubMed

Amagdei, Anca; Balteş, Felicia Rodica; Avram, Julia; Miu, Andrei C

2010-02-01

Several studies have indicated that the exposure of rodents to music modulates brain development and neuroplasticity, by mechanisms that involve facilitated hippocampal neurogenesis, neurotrophin synthesis and glutamatergic signaling. This study focused on the potential protection that the perinatal exposure to music, between postnatal days 2 and 32, could offer against functional deficits induced by neonatal callosotomy in rats. The spontaneous alternation and marble-burying behaviors were longitudinally measured in callosotomized and control rats that had been exposed to music or not. The results indicated that the neonatal callosotomy-induced spontaneous alternation deficits that became apparent only after postnatal day 45, about the time when the rat corpus callosum reaches its maximal levels of myelination. The perinatal exposure to music efficiently protected the spontaneous alternation performance against the deficits induced by callosotomy. The present findings may offer important insights into music-induced neuroplasticity, relevant to brain development and neurorehabilitation. Copyright 2009 ISDN. Published by Elsevier Ltd. All rights reserved.

Marchiafava-Bignami Disease with Cortical Involvement.

PubMed

Zhao, Panpan; Zhang, Hongliang; Zhang, Ying; Sun, Li

2018-06-01

Marchiafava-Bignami disease (MBD) is a neurological degenerative disorder with a pathognomonic hallmark of symmetric demyelination in the corpus callosum (CC). Most reported cases were chronic alcoholics and some showed cortical lesions related to poor clinical prognosis. Herein we report a case of a chronic alcoholic who presented with confusion and generalized weakness. Nerve fiber integrity and metabolic changes were evaluated with Magnetic resonance imaging (MRI) sequences including diffusion tensor imaging (DTI) and MRS. MRI revealed the typical callosal lesions of MBD with bilateral frontoparietal cortical lesions. DTI and MRS showed both impaired myelin integrity and axonal density in the CC. The cortical lesions partly disappeared after intravenous administration of high-dose multivitamins and corticosteroids. The patient regained consciousness 3 months later while dysarthria and quadriplegia persisted. Three years later, the patient can interact occasionally with people and the functional activities of both upper and lower limbs have no improvement. To our knowledge, this is the first report of DTI together with MRS assisting in evaluating the prognosis of MBD.

White versus gray matter: fMRI hemodynamic responses show similar characteristics, but differ in peak amplitude

PubMed Central

2012-01-01

Background There is growing evidence for the idea of fMRI activation in white matter. In the current study, we compared hemodynamic response functions (HRF) in white matter and gray matter using 4 T fMRI. White matter fMRI activation was elicited in the isthmus of the corpus callosum at both the group and individual levels (using an established interhemispheric transfer task). Callosal HRFs were compared to HRFs from cingulate and parietal activation. Results Examination of the raw HRF revealed similar overall response characteristics. Finite impulse response modeling confirmed that the WM HRF characteristics were comparable to those of the GM HRF, but had significantly decreased peak response amplitudes. Conclusions Overall, the results matched a priori expectations of smaller HRF responses in white matter due to the relative drop in cerebral blood flow (CBF) and cerebral blood volume (CBV). Importantly, the findings demonstrate that despite lower CBF and CBV, white matter fMRI activation remained within detectable ranges at 4 T. PMID:22852798

Genetics Home Reference: acrocallosal syndrome

MedlinePlus

... callosum occurs when the tissue that connects the left and right halves of the brain (the corpus callosum ) fails to form normally during the early stages of development before birth. Other brain abnormalities, including the growth ...

Reversible splenial lesion syndrome associated with lobar pneumonia

PubMed Central

Li, Chunrong; Wu, Xiujuan; Qi, Hehe; Cheng, Yanwei; Zhang, Bing; Zhou, Hongwei; Lv, Xiaohong; Liu, Kangding; Zhang, Hong-Liang

2016-01-01

Abstract Background: Reversible splenial lesion syndrome (RESLES) is a rare clinico-radiological disorder with unclear pathophysiology. Clinically, RESLES is defined as reversible isolated splenial lesions in the corpus callosum, which can be readily identified by magnetic resonance imaging (MRI) and usually resolve completely over a period of time. RESLES could be typically triggered by infection, antiepileptic drugs (AEDs), poisoning, etc. More factors are increasingly recognized. Methods and results: We reported herein an 18-year-old female patient with lobar pneumonia who developed mental abnormalities during hospitalization. An isolated splenial lesion in the corpus callosum was found by head MRI and the lesion disappeared 15 days later. Based on her clinical manifestations and radiological findings, she was diagnosed with lobar pneumonia associated RESLES. We further summarize the up-to-date knowledge about the etiology, possible pathogenesis, clinical manifestations, radiological features, treatment, and prognosis of RESLES. Conclusion: This report contributes to the clinical understanding of RESLES which may present with mental abnormalities after infection. The characteristic imaging of reversible isolated splenial lesions in the corpus callosum was confirmed in this report. The clinical manifestations and lesions on MRI could disappear naturally after 1 month without special treatment. PMID:27684805

The function of the corpus luteum of pregnancy in ovulatory dysfunction and luteal phase deficiency.

PubMed

Soules, M R; Hughes, C L; Aksel, S; Tyrey, L; Hammond, C B

1981-07-01

Relatively little knowledge exists of corpus luteum function in early pregnancy after the successful treatment of ovulatory dysfunction or luteal phase deficiency. To assess the activity of the corpus luteum of such patients, human chorionic gonadotropin (hCG) and 17-hydroxyprogesterone (17-OH-P) levels were determined in serum samples obtained from normal women (44 patients), women with ovulatory dysfunction (10 patients), and women with luteal phase deficiency (7 patients); all determinations were made during conceptive cycles, and sampling continued into the first trimester of pregnancy. There were no statistically significant abnormalities of hCG levels when infertility patients were compared with control patients. According to the premise that 17-OH-P levels reflect corpus luteal function, there appeared to be adequate function in pregnancies after progesterone treatment of luteal phase deficiency. In pregnancies following ovulation induction with clomiphene, the corpus luteum function, on the basis of 17-OH-P levels, was significantly increased in magnitude and duration. These results have clinical implications with regard to supplemental hormone therapy in early pregnancy.

Reactive amyloidosis associated with ischial callosititis: a report with histology of ischial callosities in rhesus macaques (Macaca mulatta).

PubMed

Liu, David X; Gilbert, Margaret H; Wang, Xiaolei; Didier, Peter J; Veazey, Ronald S

2012-11-01

Ischial callosities have received little attention in veterinary medicine even though they are distinguishing anatomic organs. The organs are characterized by a pair of hairless pads of thickened epidermis, located bilaterally in the gluteal region, which overlay the tuberosities of the ischia of all Old World monkeys, gibbons, and siamangs. The current report describes a case of reactive amyloidosis associated with ischial callosititis in a rhesus macaque (Macaca mulatta). Amyloid A (AA) protein was found in the liver, spleen, small intestine, mesenteric lymph nodes, and ischial callosities by histology, Congo red stain, and immunohistochemistry. Confocal microscopy showed that many cluster of differentiation (CD)68-positive macrophages within the ischial callosities contained intracellular AA protein, which suggests that CD68-positive macrophages have an important role in the pathogenesis of reactive amyloidosis in nonhuman primates. The normal histology of ischial callosities of rhesus macaques is also documented in this report.

Agenesis of Corpus Callosum and Emotional Information Processing in Schizophrenia

PubMed Central

Lungu, Ovidiu; Stip, Emmanuel

2012-01-01

Corpus callosum (CC) is essential in providing the integration of information related to perception and action within a subcortico-cortical network, thus supporting the generation of a unified experience about and reaction to changes in the environment. Its role in schizophrenia is yet to be fully elucidated, but there is accumulating evidence that there could be differences between patients and healthy controls regarding the morphology and function of CC, especially when individuals face emotionally laden information. Here, we report a case study of a patient with partial agenesis of corpus callosum (agCC patient with agenesis of the anterior aspect, above the genu) and we provide a direct comparison with a group of patients with no apparent callosal damage (CC group) regarding the brain activity during the processing of emotionally laden information. We found that although the visual cortex activation in response to visual stimuli regardless of their emotional content was comparable in agCC patient and CC group both in terms of localization and intensity of activation, we observed a very large, non-specific and non-lateralized cerebral activation in the agCC patient, in contrast with the CC group, which showed a more lateralized and spatially localized activation, when the emotional content of the stimuli was considered. Further analysis of brain activity in the regions obtained in the CC group revealed that the agCC patient actually had an opposite activation pattern relative to most participants with no CC agenesis, indicating a dysfunctional response to these kind of stimuli, consistent with the clinical presentation of this particular patient. Our results seem to give support to the disconnection hypothesis which posits that the core symptoms of schizophrenia are related to aberrant connectivity between distinct brain areas, especially when faced with emotional stimuli, a fact consistent with the clinical tableau of this particular patient. PMID:22347194

Agenesis of corpus callosum and emotional information processing in schizophrenia.

PubMed

Lungu, Ovidiu; Stip, Emmanuel

2012-01-01

Corpus callosum (CC) is essential in providing the integration of information related to perception and action within a subcortico-cortical network, thus supporting the generation of a unified experience about and reaction to changes in the environment. Its role in schizophrenia is yet to be fully elucidated, but there is accumulating evidence that there could be differences between patients and healthy controls regarding the morphology and function of CC, especially when individuals face emotionally laden information. Here, we report a case study of a patient with partial agenesis of corpus callosum (agCC patient with agenesis of the anterior aspect, above the genu) and we provide a direct comparison with a group of patients with no apparent callosal damage (CC group) regarding the brain activity during the processing of emotionally laden information. We found that although the visual cortex activation in response to visual stimuli regardless of their emotional content was comparable in agCC patient and CC group both in terms of localization and intensity of activation, we observed a very large, non-specific and non-lateralized cerebral activation in the agCC patient, in contrast with the CC group, which showed a more lateralized and spatially localized activation, when the emotional content of the stimuli was considered. Further analysis of brain activity in the regions obtained in the CC group revealed that the agCC patient actually had an opposite activation pattern relative to most participants with no CC agenesis, indicating a dysfunctional response to these kind of stimuli, consistent with the clinical presentation of this particular patient. Our results seem to give support to the disconnection hypothesis which posits that the core symptoms of schizophrenia are related to aberrant connectivity between distinct brain areas, especially when faced with emotional stimuli, a fact consistent with the clinical tableau of this particular patient.

G-Protein-Coupled Receptor Gpr17 Expression in Two Multiple Sclerosis Remyelination Models.

PubMed

Nyamoya, Stella; Leopold, Patrizia; Becker, Birte; Beyer, Cordian; Hustadt, Fabian; Schmitz, Christoph; Michel, Anne; Kipp, Markus

2018-06-05

In multiple sclerosis patients, demyelination is prominent in both the white and gray matter. Chronic clinical deficits are known to result from acute or chronic injury to the myelin sheath and inadequate remyelination. The underlying molecular mechanisms of remyelination and its failure remain currently unclear. Recent studies have recognized G protein-coupled receptor 17 (GPR17) as an important regulator of oligodendrocyte development and remyelination. So far, the relevance of GPR17 for myelin repair was mainly tested in remyelinating white matter lesions. The relevance of GPR17 for gray matter remyelination as well as remyelination of chronic white matter lesions was not addressed so far. Here, we provide a detailed characterization of GPR17 expression during experimental de- and remyelination. Experimental lesions with robust and limited endogenous remyelination capacity were established by either acute or chronic cuprizone-induced demyelination. Furthermore, remyelinating lesions were induced by the focal injection of lysophosphatidylcholine (LPC) into the corpus callosum. GPR17 expression was analyzed by complementary techniques including immunohistochemistry, in situ hybridization, and real-time PCR. In control animals, GPR17 + cells were evenly distributed in the corpus callosum and cortex and displayed a highly ramified morphology. Virtually all GPR17 + cells also expressed the oligodendrocyte-specific transcription factor OLIG2. After acute cuprizone-induced demyelination, robust endogenous remyelination was evident in the white matter corpus callosum but not in the gray matter cortex. Endogenous callosal remyelination was paralleled by a robust induction of GPR17 expression which was absent in the gray matter cortex. Higher numbers of GPR17 + cells were as well observed after LPC-induced focal white matter demyelination. In contrast, densities of GPR17 + cells were comparable to control animals after chronic cuprizone-induced demyelination indicating quiescence of this cell population. Our findings demonstrate that GPR17 expression induction correlates with acute demyelination and sufficient endogenous remyelination. This strengthens the view that manipulation of this receptor might be a therapeutic opportunity to support endogenous remyelination.

Developmental evolution of flowering plant pollen tube cell walls: callose synthase (CalS) gene expression patterns

PubMed Central

2011-01-01

Background A number of innovations underlie the origin of rapid reproductive cycles in angiosperms. A critical early step involved the modification of an ancestrally short and slow-growing pollen tube for faster and longer distance transport of sperm to egg. Associated with this shift are the predominantly callose (1,3-β-glucan) walls and septae (callose plugs) of angiosperm pollen tubes. Callose synthesis is mediated by callose synthase (CalS). Of 12 CalS gene family members in Arabidopsis, only one (CalS5) has been directly linked to pollen tube callose. CalS5 orthologues are present in several monocot and eudicot genomes, but little is known about the evolutionary origin of CalS5 or what its ancestral function may have been. Results We investigated expression of CalS in pollen and pollen tubes of selected non-flowering seed plants (gymnosperms) and angiosperms within lineages that diverged below the monocot/eudicot node. First, we determined the nearly full length coding sequence of a CalS5 orthologue from Cabomba caroliniana (CcCalS5) (Nymphaeales). Semi-quantitative RT-PCR demonstrated low CcCalS5 expression within several vegetative tissues, but strong expression in mature pollen. CalS transcripts were detected in pollen tubes of several species within Nymphaeales and Austrobaileyales, and comparative analyses with a phylogenetically diverse group of sequenced genomes indicated homology to CalS5. We also report in silico evidence of a putative CalS5 orthologue from Amborella. Among gymnosperms, CalS5 transcripts were recovered from germinating pollen of Gnetum and Ginkgo, but a novel CalS paralog was instead amplified from germinating pollen of Pinus taeda. Conclusion The finding that CalS5 is the predominant callose synthase in pollen tubes of both early-diverging and model system angiosperms is an indicator of the homology of their novel callosic pollen tube walls and callose plugs. The data suggest that CalS5 had transient expression and pollen-specific functions in early seed plants and was then recruited to novel expression patterns and functions within pollen tube walls in an ancestor of extant angiosperms. PMID:21722365

Callose biosynthesis regulates symplastic trafficking during root development.

PubMed

Vatén, Anne; Dettmer, Jan; Wu, Shuang; Stierhof, York-Dieter; Miyashima, Shunsuke; Yadav, Shri Ram; Roberts, Christina J; Campilho, Ana; Bulone, Vincent; Lichtenberger, Raffael; Lehesranta, Satu; Mähönen, Ari Pekka; Kim, Jae-Yean; Jokitalo, Eija; Sauer, Norbert; Scheres, Ben; Nakajima, Keiji; Carlsbecker, Annelie; Gallagher, Kimberly L; Helariutta, Ykä

2011-12-13

Plant cells are connected through plasmodesmata (PD), membrane-lined channels that allow symplastic movement of molecules between cells. However, little is known about the role of PD-mediated signaling during plant morphogenesis. Here, we describe an Arabidopsis gene, CALS3/GSL12. Gain-of-function mutations in CALS3 result in increased accumulation of callose (β-1,3-glucan) at the PD, a decrease in PD aperture, defects in root development, and reduced intercellular trafficking. Enhancement of CALS3 expression during phloem development suppressed loss-of-function mutations in the phloem abundant callose synthase, CALS7 indicating that CALS3 is a bona fide callose synthase. CALS3 alleles allowed us to spatially and temporally control the PD aperture between plant tissues. Using this tool, we are able to show that movement of the transcription factor SHORT-ROOT and microRNA165 between the stele and the endodermis is PD dependent. Taken together, we conclude that regulated callose biosynthesis at PD is essential for cell signaling. Copyright © 2011 Elsevier Inc. All rights reserved.

Reactive amyloidosis associated with ischial callosititis: a report with histology of ischial callosities in rhesus macaques (Macaca mulatta)

PubMed Central

Liu, David X.; Gilbert, Margaret H.; Wang, Xiaolei; Didier, Peter J.; Veazey, Ronald S.

2014-01-01

Ischial callosities have received little attention in veterinary medicine even though they are distinguishing anatomic organs. The organs are characterized by a pair of hairless pads of thickened epidermis, located bilaterally in the gluteal region, which overlay the tuberosities of the ischia of all Old World monkeys, gibbons, and siamangs. The current report describes a case of reactive amyloidosis associated with ischial callosititis in a rhesus macaque (Macaca mulatta). Amyloid A (AA) protein was found in the liver, spleen, small intestine, mesenteric lymph nodes, and ischial callosities by histology, Congo red stain, and immunohistochemistry. Confocal microscopy showed that many cluster of differentiation (CD)68-positive macrophages within the ischial callosities contained intracellular AA protein, which suggests that CD68-positive macrophages have an important role in the pathogenesis of reactive amyloidosis in nonhuman primates. The normal histology of ischial callosities of rhesus macaques is also documented in this report. PMID:23104953

The Interhemispheric Transcallosal-Transversal Approach to the Lesions of the Anterior and Middle Third Ventricle: Surgical Validity and Neuropsychological Evaluation of the Outcome

ERIC Educational Resources Information Center

Mazza, M.; Di Rienzo, A.; Costagliola, C.; Roncone, R.; Casacchia, M.; Ricci, A.; Galzio, R.J.

2004-01-01

Based on the observation of the course of callosal fibres and of their artero-venous support as appearing in a microanatomic study, the Authors propose a variant of standard callosotomy procedure by the introduction of the transverse section of callosal fibres. This technique would allow the surgeon to spare a larger number of callosal fibres by…

Magnetic resonance findings of the corpus callosum in canine and feline lysosomal storage diseases.

PubMed

Hasegawa, Daisuke; Tamura, Shinji; Nakamoto, Yuya; Matsuki, Naoaki; Takahashi, Kimimasa; Fujita, Michio; Uchida, Kazuyuki; Yamato, Osamu

2013-01-01

Several reports have described magnetic resonance (MR) findings in canine and feline lysosomal storage diseases such as gangliosidoses and neuronal ceroid lipofuscinosis. Although most of those studies described the signal intensities of white matter in the cerebrum, findings of the corpus callosum were not described in detail. A retrospective study was conducted on MR findings of the corpus callosum as well as the rostral commissure and the fornix in 18 cases of canine and feline lysosomal storage diseases. This included 6 Shiba Inu dogs and 2 domestic shorthair cats with GM1 gangliosidosis; 2 domestic shorthair cats, 2 familial toy poodles, and a golden retriever with GM2 gangliosidosis; and 2 border collies and 3 chihuahuas with neuronal ceroid lipofuscinoses, to determine whether changes of the corpus callosum is an imaging indicator of those diseases. The corpus callosum and the rostral commissure were difficult to recognize in all cases of juvenile-onset gangliosidoses (GM1 gangliosidosis in Shiba Inu dogs and domestic shorthair cats and GM2 gangliosidosis in domestic shorthair cats) and GM2 gangliosidosis in toy poodles with late juvenile-onset. In contrast, the corpus callosum and the rostral commissure were confirmed in cases of GM2 gangliosidosis in a golden retriever and canine neuronal ceroid lipofuscinoses with late juvenile- to early adult-onset, but were extremely thin. Abnormal findings of the corpus callosum on midline sagittal images may be a useful imaging indicator for suspecting lysosomal storage diseases, especially hypoplasia (underdevelopment) of the corpus callosum in juvenile-onset gangliosidoses.

Magnetic Resonance Findings of the Corpus Callosum in Canine and Feline Lysosomal Storage Diseases

PubMed Central

Hasegawa, Daisuke; Tamura, Shinji; Nakamoto, Yuya; Matsuki, Naoaki; Takahashi, Kimimasa; Fujita, Michio; Uchida, Kazuyuki; Yamato, Osamu

2013-01-01

Several reports have described magnetic resonance (MR) findings in canine and feline lysosomal storage diseases such as gangliosidoses and neuronal ceroid lipofuscinosis. Although most of those studies described the signal intensities of white matter in the cerebrum, findings of the corpus callosum were not described in detail. A retrospective study was conducted on MR findings of the corpus callosum as well as the rostral commissure and the fornix in 18 cases of canine and feline lysosomal storage diseases. This included 6 Shiba Inu dogs and 2 domestic shorthair cats with GM1 gangliosidosis; 2 domestic shorthair cats, 2 familial toy poodles, and a golden retriever with GM2 gangliosidosis; and 2 border collies and 3 chihuahuas with neuronal ceroid lipofuscinoses, to determine whether changes of the corpus callosum is an imaging indicator of those diseases. The corpus callosum and the rostral commissure were difficult to recognize in all cases of juvenile-onset gangliosidoses (GM1 gangliosidosis in Shiba Inu dogs and domestic shorthair cats and GM2 gangliosidosis in domestic shorthair cats) and GM2 gangliosidosis in toy poodles with late juvenile-onset. In contrast, the corpus callosum and the rostral commissure were confirmed in cases of GM2 gangliosidosis in a golden retriever and canine neuronal ceroid lipofuscinoses with late juvenile- to early adult-onset, but were extremely thin. Abnormal findings of the corpus callosum on midline sagittal images may be a useful imaging indicator for suspecting lysosomal storage diseases, especially hypoplasia (underdevelopment) of the corpus callosum in juvenile-onset gangliosidoses. PMID:24386203

Adult severe encephalitis/encephalopathy with a reversible splenial lesion of the corpus callosum: A case report.

PubMed

Mao, Xi-Jing; Zhu, Bo-Chi; Yu, Ting-Min; Yao, Gang

2018-06-01

Clinically mild encephalitis/encephalopathy with a reversible splenial lesion of the corpus callosum (MERS) is a recently identified clinically and radiologically distinct syndrome. Clinical symptoms and lesions on the magnetic resonance imaging (MRI) often disappear in 1 week or a few weeks. However, MERS manifesting as a severe clinical course with significant sequela has not yet been reported. A 42-year-old male presented with a 3-day history of headache, fever, and irrational speech. Physical examination showed a body temperature of 39.5°C, dysarthria, dyscalculia, recent memory disturbance, and otherwise normal vital signs. The patient developed status epilepticus and progressive consciousness disturbance. MRI showed abnormal patchy signals in the splenium of the corpus callosum. The clinical feature and the characteristic of MRI are mostly consistent with MERS. At the same time, we made a differential diagnosis by testing the NMDARAb, AMPA1Ab, AMPA2Ab, LG1Ab, CASPR2Ab, GABABRAb in CSF and serum. The subject was treated with ganciclovir, antiepileptic, and antipyretic therapy. The subject was living a virtually normal life with persistent mild memory disturbance. MRI showed that the abnormal signals in the splenium of the corpus callosum had disappeared, but hyperintensity on T2-weighted and FLAIR imaging was noted in the centrum semiovale. MERS is a rare clinicoradiological syndrome, which can manifest as severe symptoms as well. Early diagnosis and treatment should be emphasized, and the diagnostic value of MRI is highlighted. Clinicians should be alert to the potential sequela.

Dichotic listening in patients with splenial and nonsplenial callosal lesions.

PubMed

Pollmann, Stefan; Maertens, Marianne; von Cramon, D Yves; Lepsien, Joeran; Hugdahl, Kenneth

2002-01-01

The authors found splenial lesions to be associated with left ear suppression in dichotic listening of consonant-vowel syllables. This was found in both a rapid presentation dichotic monitoring task and a standard dichotic listening task, ruling out attentional limitations in the processing of high stimulus loads as a confounding factor. Moreover, directed attention to the left ear did not improve left ear target detection in the patients, independent of callosal lesion location. The authors' data may indicate that auditory callosal fibers pass through the splenium more posterior than previously thought. However, further studies should investigate whether callosal fibers between primary and secondary auditory cortices, or between higher level multimodal cortices, are vital for the detection of left ear targets in dichotic listening.

Cross-Hemispheric Collaboration and Segregation Associated with Task Difficulty as Revealed by Structural and Functional Connectivity

PubMed Central

Cabeza, Roberto

2015-01-01

Although it is known that brain regions in one hemisphere may interact very closely with their corresponding contralateral regions (collaboration) or operate relatively independent of them (segregation), the specific brain regions (where) and conditions (how) associated with collaboration or segregation are largely unknown. We investigated these issues using a split field-matching task in which participants matched the meaning of words or the visual features of faces presented to the same (unilateral) or to different (bilateral) visual fields. Matching difficulty was manipulated by varying the semantic similarity of words or the visual similarity of faces. We assessed the white matter using the fractional anisotropy (FA) measure provided by diffusion tensor imaging (DTI) and cross-hemispheric communication in terms of fMRI-based connectivity between homotopic pairs of cortical regions. For both perceptual and semantic matching, bilateral trials became faster than unilateral trials as difficulty increased (bilateral processing advantage, BPA). The study yielded three novel findings. First, whereas FA in anterior corpus callosum (genu) correlated with word-matching BPA, FA in posterior corpus callosum (splenium-occipital) correlated with face-matching BPA. Second, as matching difficulty intensified, cross-hemispheric functional connectivity (CFC) increased in domain-general frontopolar cortex (for both word and face matching) but decreased in domain-specific ventral temporal lobe regions (temporal pole for word matching and fusiform gyrus for face matching). Last, a mediation analysis linking DTI and fMRI data showed that CFC mediated the effect of callosal FA on BPA. These findings clarify the mechanisms by which the hemispheres interact to perform complex cognitive tasks. PMID:26019335

Abnormal brain connectivity in first-episode psychosis: A diffusion MRI tractography study of the corpus callosum

PubMed Central

Price, Gary; Cercignani, Mara; Parker, Geoffrey J.M.; Altmann, Daniel R.; Barnes, Thomas R.E.; Barker, Gareth J.; Joyce, Eileen M.; Ron, Maria A.

2007-01-01

A model of disconnectivity involving abnormalities in the cortex and connecting white matter pathways may explain the clinical manifestations of schizophrenia. Recently, diffusion imaging tractography has made it possible to study white matter pathways in detail and we present here a study of patients with first-episode psychosis using this technique. We selected the corpus callosum for this study because there is evidence that it is abnormal in schizophrenia. In addition, the topographical organization of its fibers makes it possible to relate focal abnormalities to specific cortical regions. Eighteen patients with first-episode psychosis and 21 healthy subjects took part in the study. A probabilistic tractography algorithm (PICo) was used to study fractional anisotropy (FA). Seed regions were placed in the genu and splenium to track fiber tracts traversing these regions, and a multi-threshold approach to study the probability of connection was used. Multiple linear regressions were used to explore group differences. FA, a measure of tract coherence, was reduced in tracts crossing the genu, and to a lesser degree the splenium, in patients compared with controls. FA was also lower in the genu in females across both groups, but there was no gender-by-group interaction. The FA reduction in patients may be due to aberrant myelination or axonal abnormalities, but the similar tract volumes in the two groups suggest that severe axonal loss is unlikely at this stage of the illness. PMID:17275337

Brief Report: Acrocallosal Syndrome and Autism

ERIC Educational Resources Information Center

Steiner, Carlos Eduardo; Guerreiro, Marilisa Mantovani; Marques-de-Faria, Antonia Paula

2004-01-01

The authors describe a boy presenting with acrocallosal syndrome and autism. Clinical features included craniofacial dysmorphisms, polydactyly, and mental retardation, besides behavioral symptoms compatible with autism. Neuroimaging revealed hypoplasia of the corpus callosum and cerebellar abnormalities. The role of this entity and other…

Callosal connections of dorso-lateral premotor cortex.

PubMed

Marconi, B; Genovesio, A; Giannetti, S; Molinari, M; Caminiti, R

2003-08-01

This study investigated the organization of the callosal connections of the two subdivisions of the monkey dorsal premotor cortex (PMd), dorso-rostral (F7) and dorso-caudal (F2). In one animal, Fast blue and Diamidino yellow were injected in F7 and F2, respectively; in a second animal, the pattern of injections was reversed. F7 and F2 receive a major callosal input from their homotopic counterpart. The heterotopic connections of F7 originate mainly from F2, with smaller contingent from pre-supplementary motor area (pre-SMA, F6), area 8 (frontal eye fields), and prefrontal cortex (area 46), while those of F2 originate from F7, with smaller contributions from ventral premotor areas (F5, F4), SMA-proper (F3), and primary motor cortex (M1). Callosal cells projecting homotopically are mostly located in layers II-III, those projecting heterotopically occupy layers II-III and V-VI. A spectral analysis was used to characterize the spatial fluctuations of the distribution of callosal neurons, in both F7 and F2, as well as in adjacent cortical areas. The results revealed two main periodic components. The first, in the domain of the low spatial frequencies, corresponds to periodicities of cell density with peak-to-peak distances of approximately 10 mm, and suggests an arrangement of callosal cells in the form of 5-mm wide bands. The second corresponds to periodicities of approximately 2 mm, and probably reflects a 1-mm columnar-like arrangement. Coherency and phase analyses showed that, although similar in their spatial arrangements, callosal cells projecting to dorsal premotor areas are segregated in the tangential cortical domain.

Secreted Fungal Effector Lipase Releases Free Fatty Acids to Inhibit Innate Immunity-Related Callose Formation during Wheat Head Infection[W][OPEN

PubMed Central

Blümke, Antje; Falter, Christian; Herrfurth, Cornelia; Sode, Björn; Bode, Rainer; Schäfer, Wilhelm; Feussner, Ivo; Voigt, Christian A.

2014-01-01

The deposition of the (1,3)-β-glucan cell wall polymer callose at sites of attempted penetration is a common plant defense response to intruding pathogens and part of the plant’s innate immunity. Infection of the Fusarium graminearum disruption mutant Δfgl1, which lacks the effector lipase FGL1, is restricted to inoculated wheat (Triticum aestivum) spikelets, whereas the wild-type strain colonized the whole wheat spike. Our studies here were aimed at analyzing the role of FGL1 in establishing full F. graminearum virulence. Confocal laser-scanning microscopy revealed that the Δfgl1 mutant strongly induced the deposition of spot-like callose patches in vascular bundles of directly inoculated spikelets, while these callose deposits were not observed in infections by the wild type. Elevated concentrations of the polyunsaturated free fatty acids (FFAs) linoleic and α-linolenic acid, which we detected in F. graminearum wild type-infected wheat spike tissue compared with Δfgl1-infected tissue, provided clear evidence for a suggested function of FGL1 in suppressing callose biosynthesis. These FFAs not only inhibited plant callose biosynthesis in vitro and in planta but also partially restored virulence to the Δfgl1 mutant when applied during infection of wheat spikelets. Additional FFA analysis confirmed that the purified effector lipase FGL1 was sufficient to release linoleic and α-linolenic acids from wheat spike tissue. We concluded that these two FFAs have a major function in the suppression of the innate immunity-related callose biosynthesis and, hence, the progress of F. graminearum wheat infection. PMID:24686113

Callose homeostasis at plasmodesmata: molecular regulators and developmental relevance

PubMed Central

De Storme, Nico; Geelen, Danny

2014-01-01

Plasmodesmata are membrane-lined channels that are located in the plant cell wall and that physically interconnect the cytoplasm and the endoplasmic reticulum (ER) of adjacent cells. Operating as controllable gates, plasmodesmata regulate the symplastic trafficking of micro- and macromolecules, such as endogenous proteins [transcription factors (TFs)] and RNA-based signals (mRNA, siRNA, etc.), hence mediating direct cell-to-cell communication and long distance signaling. Besides this physiological role, plasmodesmata also form gateways through which viral genomes can pass, largely facilitating the pernicious spread of viral infections. Plasmodesmatal trafficking is either passive (e.g., diffusion) or active and responses both to developmental and environmental stimuli. In general, plasmodesmatal conductivity is regulated by the controlled build-up of callose at the plasmodesmatal neck, largely mediated by the antagonistic action of callose synthases (CalSs) and β-1,3-glucanases. Here, in this theory and hypothesis paper, we outline the importance of callose metabolism in PD SEL control, and highlight the main molecular factors involved. In addition, we also review other proteins that regulate symplastic PD transport, both in a developmental and stress-responsive framework, and discuss on their putative role in the modulation of PD callose turn-over. Finally, we hypothesize on the role of structural sterols in the regulation of (PD) callose deposition and outline putative mechanisms by which this regulation may occur. PMID:24795733

A membrane-associated form of sucrose synthase and its potential role in synthesis of cellulose and callose in plants.

PubMed Central

Amor, Y; Haigler, C H; Johnson, S; Wainscott, M; Delmer, D P

1995-01-01

Sucrose synthase (SuSy; EC 2.4.1.13; sucrose + UDP reversible UDPglucose + fructose) has always been studied as a cytoplasmic enzyme in plant cells where it serves to degrade sucrose and provide carbon for respiration and synthesis of cell wall polysaccharides and starch. We report here that at least half of the total SuSy of developing cotton fibers (Gossypium hirsutum) is tightly associated with the plasma membrane. Therefore, this form of SuSy might serve to channel carbon directly from sucrose to cellulose and/or callose synthases in the plasma membrane. By using detached and permeabilized cotton fibers, we show that carbon from sucrose can be converted at high rates to both cellulose and callose. Synthesis of cellulose or callose is favored by addition of EGTA or calcium and cellobiose, respectively. These findings contrast with the traditional observation that when UDPglucose is used as substrate in vitro, callose is the major product synthesized. Immunolocalization studies show that SuSy can be localized at the fiber surface in patterns consistent with the deposition of cellulose or callose. Thus, these results support a model in which SuSy exists in a complex with the beta-glucan synthases and serves to channel carbon from sucrose to glucan. Images Fig. 1 Fig. 3 Fig. 4 PMID:7568131

Proximal Hypospadias

PubMed Central

Kraft, Kate H.; Shukla, Aseem R.; Canning, Douglas A.

2011-01-01

Hypospadias results from abnormal development of the penis that leaves the urethral meatus proximal to its normal glanular position. Meatal position may be located anywhere along the penile shaft, but more severe forms of hypospadias may have a urethral meatus located at the scrotum or perineum. The spectrum of abnormalities may also include ventral curvature of the penis, a dorsally redundant prepuce, and atrophic corpus spongiosum. Due to the severity of these abnormalities, proximal hypospadias often requires more extensive reconstruction in order to achieve an anatomically and functionally successful result. We review the spectrum of proximal hypospadias etiology, presentation, correction, and possible associated complications. PMID:21516286

Diffusion tensor imaging with tract-based spatial statistics reveals local white matter abnormalities in preterm infants.

PubMed

Anjari, Mustafa; Srinivasan, Latha; Allsop, Joanna M; Hajnal, Joseph V; Rutherford, Mary A; Edwards, A David; Counsell, Serena J

2007-04-15

Infants born preterm have a high incidence of neurodevelopmental impairment in later childhood, often associated with poorly defined cerebral white matter abnormalities. Diffusion tensor imaging quantifies the diffusion of water within tissues and can assess microstructural abnormalities in the developing preterm brain. Tract-based spatial statistics (TBSS) is an automated observer-independent method of aligning fractional anisotropy (FA) images from multiple subjects to allow groupwise comparisons of diffusion tensor imaging data. We applied TBSS to test the hypothesis that preterm infants have reduced fractional anisotropy in specific regions of white matter compared to term-born controls. We studied 26 preterm infants with no evidence of focal lesions on conventional magnetic resonance imaging (MRI) at term equivalent age and 6 healthy term-born control infants. We found that the centrum semiovale, frontal white matter and the genu of the corpus callosum showed significantly lower FA in the preterm group. Infants born at less than or equal to 28 weeks gestational age (n=11) displayed additional reductions in FA in the external capsule, the posterior aspect of the posterior limb of the internal capsule and the isthmus and middle portion of the body of the corpus callosum. This study demonstrates that TBSS provides an observer-independent method of identifying white matter abnormalities in the preterm brain at term equivalent age in the absence of focal lesions.

Right-hemispheric dominance for visual remapping in humans.

PubMed

Pisella, L; Alahyane, N; Blangero, A; Thery, F; Blanc, S; Pelisson, D

2011-02-27

We review evidence showing a right-hemispheric dominance for visuo-spatial processing and representation in humans. Accordingly, visual disorganization symptoms (intuitively related to remapping impairments) are observed in both neglect and constructional apraxia. More specifically, we review findings from the intervening saccade paradigm in humans--and present additional original data--which suggest a specific role of the asymmetrical network at the temporo-parietal junction (TPJ) in the right hemisphere in visual remapping: following damage to the right dorsal posterior parietal cortex (PPC) as well as part of the corpus callosum connecting the PPC to the frontal lobes, patient OK in a double-step saccadic task exhibited an impairment when the second saccade had to be directed rightward. This singular and lateralized deficit cannot result solely from the patient's cortical lesion and, therefore, we propose that it is due to his callosal lesion that may specifically interrupt the interhemispheric transfer of information necessary to execute accurate rightward saccades towards a remapped target location. This suggests a specialized right-hemispheric network for visuo-spatial remapping that subsequently transfers target location information to downstream planning regions, which are symmetrically organized.

Right-hemispheric dominance for visual remapping in humans

PubMed Central

Pisella, L.; Alahyane, N.; Blangero, A.; Thery, F.; Blanc, S.; Pelisson, D.

2011-01-01

We review evidence showing a right-hemispheric dominance for visuo-spatial processing and representation in humans. Accordingly, visual disorganization symptoms (intuitively related to remapping impairments) are observed in both neglect and constructional apraxia. More specifically, we review findings from the intervening saccade paradigm in humans—and present additional original data—which suggest a specific role of the asymmetrical network at the temporo-parietal junction (TPJ) in the right hemisphere in visual remapping: following damage to the right dorsal posterior parietal cortex (PPC) as well as part of the corpus callosum connecting the PPC to the frontal lobes, patient OK in a double-step saccadic task exhibited an impairment when the second saccade had to be directed rightward. This singular and lateralized deficit cannot result solely from the patient's cortical lesion and, therefore, we propose that it is due to his callosal lesion that may specifically interrupt the interhemispheric transfer of information necessary to execute accurate rightward saccades towards a remapped target location. This suggests a specialized right-hemispheric network for visuo-spatial remapping that subsequently transfers target location information to downstream planning regions, which are symmetrically organized. PMID:21242144

Callosal involvement in a lateralized stroop task in alcoholic and healthy subjects.

PubMed

Schulte, T; Müller-Oehring, E M; Salo, R; Pfefferbaum, A; Sullivan, E V

2006-11-01

To investigate the role of interhemispheric attentional processes, 25 alcoholic and 28 control subjects were tested with a Stroop match-to-sample task and callosal areas were measured with magnetic resonance imaging. Stroop color-word stimuli were presented to the left or right visual field (VF) and were preceded by a color cue that did or did not match the word's color. For matching colors, both groups showed a right VF advantage; for nonmatching colors, controls showed a left VF advantage, whereas alcoholic subjects showed no VF advantage. For nonmatch trials, VF advantage correlated with callosal splenium area in controls but not alcoholic subjects, supporting the position that information presented to the nonpreferred hemisphere is transmitted via the splenium to the hemisphere specialized for efficient processing. The authors speculate that alcoholism-associated callosal thinning disrupts this processing route.

Effect of hypothyroidism on the purinergic responses of corpus cavernosal smooth muscle in rabbits.

PubMed

Yildirim, M K; Bagcivan, I; Sarac, B; Kilicarslan, H; Yildirim, S; Kaya, T

2008-01-01

Several studies have reported evidence of hormonal abnormalities in 25-35% of impotent men. Hypothyroidism has been reported to occur in 6% of impotent men. In the present study, we examined purinergic relaxation responses in hypothyroidism in an experimental rabbit model and compared them with controls to evaluate the possible involvement of the purinergic pathway. The study comprised 20 male New Zealand white rabbits. The rabbits were divided into two equal groups. We tested the effects of ATP, alpha beta ATP, and adenosine precontracted with phenylephrine on the isolated corpus cavernosum preparations from control and hypothyroid rabbits. We also evaluated the effects of ATP, alpha beta ATP, and adenosine on the cGMP levels in the isolated corpus cavernosum preparations from control and hypothyroid rabbits. T3, T4, and testosterone levels were significantly lower in hypothyroid rabbits. ATP, alpha beta ATP, carbachol, and electrical field stimulation (EFS)-induced frequency-dependent relaxation responses in the isolated rabbit corpus cavernosum strips precontracted with phenylephrine reduced significantly (P<0.05). Adenosine-induced relaxation responses did not change significantly in hypothyroid rabbits. Reduction of relaxation response in hypothyroid rabbits corpus cavernosum can depend on a decreased release of nitric oxide (NO) from nitrergic nerves and endothelium.

Molecular genetics in fetal neurology.

PubMed

Huang, Jin; Wah, Isabella Y M; Pooh, Ritsuko K; Choy, Kwong Wai

2012-12-01

Brain malformations, particularly related to early brain development, are a clinically and genetically heterogeneous group of fetal neurological disorders. Fetal cerebral malformation, predominantly of impaired prosencephalic development namely agenesis of the corpus callosum and septo-optic dysplasia, is the main pathological feature in fetus, and causes prominent neurodevelopmental retardation, and associated with congenital facial anomalies and visual disorders. Differential diagnosis of brain malformations can be extremely difficult even through magnetic resonance imaging. Advances in genomic and molecular genetics technologies have led to the identification of the sonic hedgehog pathways and genes critical to the normal brain development. Molecular cytogenetic and genetic studies have identified numeric and structural chromosomal abnormalities as well as mutations in genes important for the etiology of fetal neurological disorders. In this review, we update the molecular genetics findings of three common fetal neurological abnormalities, holoprosencephaly, lissencephaly and agenesis of the corpus callosum, in an attempt to assist in perinatal and prenatal diagnosis. Copyright © 2012 Elsevier Ltd. All rights reserved.

Boomerang sign: Clinical significance of transient lesion in splenium of corpus callosum.

PubMed

Malhotra, Hardeep Singh; Garg, Ravindra Kumar; Vidhate, Mukund R; Sharma, Pawan Kumar

2012-04-01

Transient signal abnormality in the splenium of corpus callosum on magnetic resonance imaging (MRI) is occasionally encountered in clinical practice. It has been reported in various clinical conditions apart from patients with epilepsy. We describe 4 patients with different etiologies presenting with signal changes in the splenium of corpus callosum. They were diagnosed as having progressive myoclonic epilepsy (case 1), localization-related epilepsy (case 2), hemicrania continua (case 3), and postinfectious parkinsonism (case 4). While three patients had complete involvement of the splenium on diffusion-weighted image ("boomerang sign"), the patient having hemicrania continua showed semilunar involvement ("mini-boomerang") on T2-weighted and FLAIR image. All the cases had noncontiguous involvement of the splenium. We herein, discuss these cases with transient splenial involvement and stress that such patients do not need aggressive diagnostic and therapeutic interventions. An attempt has been made to review the literature regarding the pathophysiology, etiology, and outcome of such lesions.

Further delineation of the clinical spectrum in RNU4ATAC related microcephalic osteodysplastic primordial dwarfism type I.

PubMed

Abdel-Salam, Ghada M H; Abdel-Hamid, Mohamed S; Hassan, Nihal A; Issa, Mahmoud Y; Effat, Laila; Ismail, Samira; Aglan, Mona S; Zaki, Maha S

2013-08-01

We describe five patients from three different families with microcephalic osteodysplastic primordial dwarfism type I (MOPD I), which was molecularly confirmed by homozygosity for the g.51G >A and g.55G >A mutations in RNU4ATAC, respectively. The patients showed the classical phenotype and demonstrated in addition variable degrees of gyration abnormalities and malformations of the callosal body with an interhemispheric cyst. One patient also showed underdevelopment of the cerebellar vermis. This confirms that cortical malformations should be considered cardinal manifestations of MOPD I. Oculocutaneous albinism, brain hemorrhage and chilblains have been found to be associated with MOPD I. The present study showed lack of retinal pigmentation in three patients of whom two had an unusually fair complexion of hair and skin. One patient was found to have a hematoma in the left thalamus. This may indicate that both pigmentary abnormalities and vascular anomalies may be part of the phenotype of MOPD I as well. Copyright © 2013 Wiley Periodicals, Inc.

White matter microstructural properties correlate with sensorimotor synchronization abilities.

PubMed

Blecher, Tal; Tal, Idan; Ben-Shachar, Michal

2016-09-01

Sensorimotor synchronization (SMS) to an external auditory rhythm is a developed ability in humans, particularly evident in dancing and singing. This ability is typically measured in the lab via a simple task of finger tapping to an auditory beat. While simplistic, there is some evidence that poor performance on this task could be related to impaired phonological and reading abilities in children. Auditory-motor synchronization is hypothesized to rely on a tight coupling between auditory and motor neural systems, but the specific pathways that mediate this coupling have not been identified yet. In this study, we test this hypothesis and examine the contribution of fronto-temporal and callosal connections to specific measures of rhythmic synchronization. Twenty participants went through SMS and diffusion magnetic resonance imaging (dMRI) measurements. We quantified the mean asynchrony between an auditory beat and participants' finger taps, as well as the time to resynchronize (TTR) with an altered meter, and examined the correlations between these behavioral measures and diffusivity in a small set of predefined pathways. We found significant correlations between asynchrony and fractional anisotropy (FA) in the left (but not right) arcuate fasciculus and in the temporal segment of the corpus callosum. On the other hand, TTR correlated with FA in the precentral segment of the callosum. To our knowledge, this is the first demonstration that relates these particular white matter tracts with performance on an auditory-motor rhythmic synchronization task. We propose that left fronto-temporal and temporal-callosal fibers are involved in prediction and constant comparison between auditory inputs and motor commands, while inter-hemispheric connections between the motor/premotor cortices contribute to successful resynchronization of motor responses with a new external rhythm, perhaps via inhibition of tapping to the previous rhythm. Our results indicate that auditory-motor synchronization skills are associated with anatomical pathways that have been previously related to phonological awareness, thus offering a possible anatomical basis for the behavioral covariance between these abilities. Copyright © 2016 Elsevier Inc. All rights reserved.

Prominent periventricular fiber system related to ganglionic eminence and striatum in the human fetal cerebrum.

PubMed

Vasung, L; Jovanov-Milošević, N; Pletikos, M; Mori, S; Judaš, M; Kostović, Ivica

2011-01-01

Periventricular pathway (PVP) system of the developing human cerebrum is situated medial to the intermediate zone in the close proximity to proliferative cell compartments. In order to elucidate chemical properties and developing trajectories of the PVP we used DTI in combination with acetylcholinesterase histochemistry, SNAP-25 immunocytochemistry and axonal cytoskeletal markers (SMI312, MAP1b) immunocytochemistry on postmortem paraformaldehyde-fixed brains of 30 human fetuses ranging in age from 10 to 38 postconceptional weeks (PCW), 2 infants (age 1-3 months) and 1 adult brain. The PVP appears in the early fetal period (10-13 PCW) as two defined fibre bundles: the corpus callosum (CC) and the fetal fronto-occipital fascicle (FOF). In the midfetal period (15-18 PCW), all four components of the PVP can be identified: (1) the CC, which at rostral levels forms a voluminous callosal plate; (2) the FOF, with SNAP-25-positive fibers; (3) the fronto-pontine pathway (FPP) which for a short distance runs within the PVP; and (4) the subcallosal fascicle of Muratoff (SFM) which contains cortico-caudate projections. The PVPs are situated medial to the internal capsule at the level of the cortico-striatal junction; they remain prominent during the late fetal and early preterm period (19-28 PCW) and represent a portion of the wider periventricular crossroad of growing associative, callosal and projection pathways. In the perinatal period, the PVPs change their topographical relationships, decrease in size and the FOF looses its SNAP-25-reactivity. In conclusion, the hitherto undescribed PVP of the human fetal cerebrum contains forerunners of adult associative and projection pathways. Its transient chemical properties and relative exuberance suggest that the PVP may exert influence on the development of cortical connectivity (intermediate targeting) and other neurogenetic events such as neuronal proliferation. The PVP's topographical position also indicates that it is a major site of vulnerability in hypoxic-ischaemic perinatal brain injury. © Springer-Verlag 2010

White Matter Microstructural Abnormalities in Type 2 Diabetes Mellitus: A Diffusional Kurtosis Imaging Analysis.

PubMed

Xie, Y; Zhang, Y; Qin, W; Lu, S; Ni, C; Zhang, Q

2017-03-01

Increasing DTI studies have demonstrated that white matter microstructural abnormalities play an important role in type 2 diabetes mellitus-related cognitive impairment. In this study, the diffusional kurtosis imaging method was used to investigate WM microstructural alterations in patients with type 2 diabetes mellitus and to detect associations between diffusional kurtosis imaging metrics and clinical/cognitive measurements. Diffusional kurtosis imaging and cognitive assessments were performed on 58 patients with type 2 diabetes mellitus and 58 controls. Voxel-based intergroup comparisons of diffusional kurtosis imaging metrics were conducted, and ROI-based intergroup comparisons were further performed. Correlations between the diffusional kurtosis imaging metrics and cognitive/clinical measurements were assessed after controlling for age, sex, and education in both patients and controls. Altered diffusion metrics were observed in the corpus callosum, the bilateral frontal WM, the right superior temporal WM, the left external capsule, and the pons in patients with type 2 diabetes mellitus compared with controls. The splenium of the corpus callosum and the pons had abnormal kurtosis metrics in patients with type 2 diabetes mellitus. Additionally, altered diffusion metrics in the right prefrontal WM were significantly correlated with disease duration and attention task performance in patients with type 2 diabetes mellitus. With both conventional diffusion and additional kurtosis metrics, diffusional kurtosis imaging can provide additional information on WM microstructural abnormalities in patients with type 2 diabetes mellitus. Our results indicate that WM microstructural abnormalities occur before cognitive decline and may be used as neuroimaging markers for predicting the early cognitive impairment in patients with type 2 diabetes mellitus. © 2017 by American Journal of Neuroradiology.

Phenotype and management of Aicardi syndrome: new findings from a survey of 69 children

USDA-ARS?s Scientific Manuscript database

Aicardi syndrome is a rare neurodevelopmental disorder characterized by agenesis of the corpus callosum, other developmental brain abnormalities, chorioretinal lacunae, and severe seizures. Current clinical knowledge is derived from small series that focus on these major defects. The authors perform...

Vocabulary, Grammar, Sex, and Aging

ERIC Educational Resources Information Center

Moscoso del Prado Martín, Fermín

2017-01-01

Understanding the changes in our language abilities along the lifespan is a crucial step for understanding the aging process both in normal and in abnormal circumstances. Besides controlled experimental tasks, it is equally crucial to investigate language in unconstrained conversation. I present an information-theoretical analysis of a corpus of…

Macrostructural abnormalities in Korsakoff syndrome compared with uncomplicated alcoholism.

PubMed

Pitel, A-L; Chételat, G; Le Berre, A P; Desgranges, B; Eustache, F; Beaunieux, H

2012-04-24

To distinguish, in patients with Korsakoff syndrome (KS), the structural brain abnormalities shared with alcoholic patients without KS (AL), from those specific to KS. MRI data were collected in 11 alcoholic patients with KS, 34 alcoholic patients without KS, and 25 healthy control subjects (CS). Gray and white matter volumes were compared in the 3 groups using a voxel-based approach. A conjunction analysis indicated a large pattern of shared gray and white matter volume deficits in AL and KS. There were graded effects of volume deficits (KS < AL < CS) in the medial portion of the thalami, hypothalamus (mammillary bodies), left insula, and genu of the corpus callosum. Abnormalities in the left thalamic radiation were observed only in KS. Our results indicate considerable similarities in the pattern of gray and white matter damage in AL and KS. This finding confirms the widespread neurotoxic effect of chronic alcohol consumption. Only a few cerebral regions, including the medial thalami, mammillary bodies, and corpus callosum, were more severely damaged in KS than in AL. The continuum of macrostructural damage from AL to KS is therefore restricted to key brain structures. Longitudinal investigations are required to determine whether alcoholic patients with medial thalamic volumes that are comparable to those of patients with KS are at increased risk of developing KS.

Receptor subtypes involved in callosally-induced postsynaptic potentials in rat frontal agranular cortex in vitro.

PubMed

Kawaguchi, Y

1992-01-01

A slice preparation of rat frontal agranular cortex preserving commissural inputs has been used for intracellular recording from layer V pyramidal cells, in order to characterize the synaptic potentials induced by stimulation of the corpus callosum and to reveal the subtypes of amino acid receptors involved. Stimulation of the corpus callosum induced EPSPs followed by early IPSPs with a peak latency of 30 +/- 2 ms and late IPSPs with a peak latency of 185 +/- 18 ms. Reversal potentials for early and late IPSPs were -75 +/- 5 mV (early) and -96 +/- 5 mV (late). Late IPSPs were more dependent on extracellular K+ concentration. The early IPSPs were blocked by GABAA antagonists, bicuculline and picrotoxin, whereas the late IPSPs were reduced by the GABAB antagonist, phaclofen. CNQX (6-cyano-7-nitroquinoxaline-2,3-dione), an antagonist of non-NMDA (N-methyl-D-aspartate) receptors, suppressed both EPSPs and late IPSPs at 5 microM. Early IPSPs remained at this concentration but were suppressed by 20 microM CNQX. In Mg(2+)-free solution, EPSPs were larger and more prolonged than in control solution. These enhanced EPSPs persisted after 5 to 20 microM CNQX, but were reduced in amplitude, and their onset was delayed by 3.6 +/- 0.8 ms. The remaining EPSPs were suppressed by 50 microM APV (DL-2-amino-5-phosphono-valeric acid), an antagonist of NMDA receptors. In Mg(2+)-free solution containing 5 to 20 microM CNQX, the late IPSPs were not diminished. The remaining late IPSPs were suppressed by APV or by phaclofen.(ABSTRACT TRUNCATED AT 250 WORDS)

New insights in the homotopic and heterotopic connectivity of the frontal portion of the human corpus callosum revealed by microdissection and diffusion tractography.

PubMed

De Benedictis, Alessandro; Petit, Laurent; Descoteaux, Maxime; Marras, Carlo Efisio; Barbareschi, Mattia; Corsini, Francesco; Dallabona, Monica; Chioffi, Franco; Sarubbo, Silvio

2016-12-01

Extensive studies revealed that the human corpus callosum (CC) plays a crucial role in providing large-scale bi-hemispheric integration of sensory, motor and cognitive processing, especially within the frontal lobe. However, the literature lacks of conclusive data regarding the structural macroscopic connectivity of the frontal CC. In this study, a novel microdissection approach was adopted, to expose the frontal fibers of CC from the dorsum to the lateral cortex in eight hemispheres and in one entire brain. Post-mortem results were then combined with data from advanced constrained spherical deconvolution in 130 healthy subjects. We demonstrated as the frontal CC provides dense inter-hemispheric connections. In particular, we found three types of fronto-callosal fibers, having a dorso-ventral organization. First, the dorso-medial CC fibers subserve homotopic connections between the homologous medial cortices of the superior frontal gyrus. Second, the ventro-lateral CC fibers subserve homotopic connections between lateral frontal cortices, including both the middle frontal gyrus and the inferior frontal gyrus, as well as heterotopic connections between the medial and lateral frontal cortices. Third, the ventro-striatal CC fibers connect the medial and lateral frontal cortices with the contralateral putamen and caudate nucleus. We also highlighted an intricate crossing of CC fibers with the main association pathways terminating in the lateral regions of the frontal lobes. This combined approach of ex vivo microdissection and in vivo diffusion tractography allowed demonstrating a previously unappreciated three-dimensional architecture of the anterior frontal CC, thus clarifying the functional role of the CC in mediating the inter-hemispheric connectivity. Hum Brain Mapp 37:4718-4735, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Effect of high-potency cannabis on corpus callosum microstructure.

PubMed

Rigucci, S; Marques, T R; Di Forti, M; Taylor, H; Dell'Acqua, F; Mondelli, V; Bonaccorso, S; Simmons, A; David, A S; Girardi, P; Pariante, C M; Murray, R M; Dazzan, P

2016-03-01

The use of cannabis with higher Δ9-tetrahydrocannabinol content has been associated with greater risk, and earlier onset, of psychosis. However, the effect of cannabis potency on brain morphology has never been explored. Here, we investigated whether cannabis potency and pattern of use are associated with changes in corpus callosum (CC) microstructural organization, in patients with first-episode psychosis (FEP) and individuals without psychosis, cannabis users and non-users. The CC of 56 FEP (37 cannabis users) and 43 individuals without psychosis (22 cannabis users) was virtually dissected and segmented using diffusion tensor imaging tractography. The diffusion index of fractional anisotropy, mean diffusivity (MD), axial diffusivity (AD) and radial diffusivity was calculated for each segment. Across the whole sample, users of high-potency cannabis had higher total CC MD and higher total CC AD than both low-potency users and those who never used (p = 0.005 and p = 0.004, respectively). Daily users also had higher total CC MD and higher total CC AD than both occasional users and those who never used (p = 0.001 and p < 0.001, respectively). However, there was no effect of group (patient/individuals without psychosis) or group x potency interaction for either potency or frequency of use. The within-group analysis showed in fact that the effects of potency and frequency were similar in FEP users and in users without psychosis. Frequent use of high-potency cannabis is associated with disturbed callosal microstructural organization in individuals with and without psychosis. Since high-potency preparations are now replacing traditional herbal drugs in many European countries, raising awareness about the risks of high-potency cannabis is crucial.

Novel FGF8 Mutations Associated with Recessive Holoprosencephaly, Craniofacial Defects, and Hypothalamo-Pituitary Dysfunction

PubMed Central

McCabe, Mark J.; Gaston-Massuet, Carles; Tziaferi, Vaitsa; Gregory, Louise C.; Alatzoglou, Kyriaki S.; Signore, Massimo; Puelles, Eduardo; Gerrelli, Dianne; Farooqi, I. Sadaf; Raza, Jamal; Walker, Joanna; Kavanaugh, Scott I.; Tsai, Pei-San; Pitteloud, Nelly; Martinez-Barbera, Juan-Pedro

2011-01-01

Context: Fibroblast growth factor (FGF) 8 is important for GnRH neuronal development with human mutations resulting in Kallmann syndrome. Murine data suggest a role for Fgf8 in hypothalamo-pituitary development; however, its role in the etiology of wider hypothalamo-pituitary dysfunction in humans is unknown. Objective: The objective of this study was to screen for FGF8 mutations in patients with septo-optic dysplasia (n = 374) or holoprosencephaly (HPE)/midline clefts (n = 47). Methods: FGF8 was analyzed by PCR and direct sequencing. Ethnically matched controls were then screened for mutated alleles (n = 480–686). Localization of Fgf8/FGF8 expression was analyzed by in situ hybridization in developing murine and human embryos. Finally, Fgf8 hypomorphic mice (Fgf8loxPNeo/−) were analyzed for the presence of forebrain and hypothalamo-pituitary defects. Results: A homozygous p.R189H mutation was identified in a female patient of consanguineous parentage with semilobar HPE, diabetes insipidus, and TSH and ACTH insufficiency. Second, a heterozygous p.Q216E mutation was identified in a female patient with an absent corpus callosum, hypoplastic optic nerves, and Moebius syndrome. FGF8 was expressed in the ventral diencephalon and anterior commissural plate but not in Rathke's pouch, strongly suggesting early onset hypothalamic and corpus callosal defects in these patients. This was consolidated by significantly reduced vasopressin and oxytocin staining neurons in the hypothalamus of Fgf8 hypomorphic mice compared with controls along with variable hypothalamo-pituitary defects and HPE. Conclusion: We implicate FGF8 in the etiology of recessive HPE and potentially septo-optic dysplasia/Moebius syndrome for the first time to our knowledge. Furthermore, FGF8 is important for the development of the ventral diencephalon, hypothalamus, and pituitary. PMID:21832120

Microstructural White Matter Alterations in the Corpus Callosum of Girls With Conduct Disorder.

PubMed

Menks, Willeke Martine; Furger, Reto; Lenz, Claudia; Fehlbaum, Lynn Valérie; Stadler, Christina; Raschle, Nora Maria

2017-03-01

Diffusion tensor imaging (DTI) studies in adolescent conduct disorder (CD) have demonstrated white matter alterations of tracts connecting functionally distinct fronto-limbic regions, but only in boys or mixed-gender samples. So far, no study has investigated white matter integrity in girls with CD on a whole-brain level. Therefore, our aim was to investigate white matter alterations in adolescent girls with CD. We collected high-resolution DTI data from 24 girls with CD and 20 typically developing control girls using a 3T magnetic resonance imaging system. Fractional anisotropy (FA) and mean diffusivity (MD) were analyzed for whole-brain as well as a priori-defined regions of interest, while controlling for age and intelligence, using a voxel-based analysis and an age-appropriate customized template. Whole-brain findings revealed white matter alterations (i.e., increased FA) in girls with CD bilaterally within the body of the corpus callosum, expanding toward the right cingulum and left corona radiata. The FA and MD results in a priori-defined regions of interest were more widespread and included changes in the cingulum, corona radiata, fornix, and uncinate fasciculus. These results were not driven by age, intelligence, or attention-deficit/hyperactivity disorder comorbidity. This report provides the first evidence of white matter alterations in female adolescents with CD as indicated through white matter reductions in callosal tracts. This finding enhances current knowledge about the neuropathological basis of female CD. An increased understanding of gender-specific neuronal characteristics in CD may influence diagnosis, early detection, and successful intervention strategies. Copyright © 2017 American Academy of Child and Adolescent Psychiatry. Published by Elsevier Inc. All rights reserved.

Impact of Early and Late Visual Deprivation on the Structure of the Corpus Callosum: A Study Combining Thickness Profile with Surface Tensor-Based Morphometry.

PubMed

Shi, Jie; Collignon, Olivier; Xu, Liang; Wang, Gang; Kang, Yue; Leporé, Franco; Lao, Yi; Joshi, Anand A; Leporé, Natasha; Wang, Yalin

2015-07-01

Blindness represents a unique model to study how visual experience may shape the development of brain organization. Exploring how the structure of the corpus callosum (CC) reorganizes ensuing visual deprivation is of particular interest due to its important functional implication in vision (e.g., via the splenium of the CC). Moreover, comparing early versus late visually deprived individuals has the potential to unravel the existence of a sensitive period for reshaping the CC structure. Here, we develop a novel framework to capture a complete set of shape differences in the CC between congenitally blind (CB), late blind (LB) and sighted control (SC) groups. The CCs were manually segmented from T1-weighted brain MRI and modeled by 3D tetrahedral meshes. We statistically compared the combination of local area and thickness at each point between subject groups. Differences in area are found using surface tensor-based morphometry; thickness is estimated by tracing the streamlines in the volumetric harmonic field. Group differences were assessed on this combined measure using Hotelling's T(2) test. Interestingly, we observed that the total callosal volume did not differ between the groups. However, our fine-grained analysis reveals significant differences mostly localized around the splenium areas between both blind groups and the sighted group (general effects of blindness) and, importantly, specific dissimilarities between the LB and CB groups, illustrating the existence of a sensitive period for reorganization. The new multivariate statistics also gave better effect sizes for detecting morphometric differences, relative to other statistics. They may boost statistical power for CC morphometric analyses.

[A case of left hand agraphia without callosal apraxia].

PubMed

Tsuzuki, S; Indo, T; Takahashi, A

1989-01-01

A 65-year-old male who had agraphia confined to the left hand was reported. The patient was admitted to the neurological department of Kasugai city Hospital because of suddenly-developed mild right-sided hemiparesis with central facial palsy. Computerized tomography of the brain was performed 2 and 14 days after admission. As a result, low-density regions were found in the left cingulate and medial frontal gyri and the trunk of the corpus callosum. Magnetic resonance imaging of the saggital plane more clearly visualized a localized infarction affecting both the trunk of the corpus callosum and its leftward outflow. Neuropsychological findings of the patient were summarized as follows. 1) He had no difficulty in any of the actual use of object, copying the manipulation of objects, and proper use of objects according to verbal commands. 2) With the eyes closed, he could correctly name the objects handed over to the right hand, while he could do only 15 out of 20 objects handed over to the left hand. However, whichever hand an object was handed to, he could explain how to use the object. 3) He could write Hiragana, Katakana, and Kanji correctly with his right hand in accordance with verbal commands, whereas with his left hand he could do only for 20% of Hiragana, 20% of Katakana, and 90% of Kanji. 4) He could copy Kanji, Hiragana, and figures with either right or left hand. 5) He could point out verbally-presented letters using letter cards whether with the right hand or with the left hand, and could also select the letter card corresponding to the letter visually-presented.(ABSTRACT TRUNCATED AT 250 WORDS)

Corpus callosum damage predicts disability progression and cognitive dysfunction in primary-progressive MS after five years.

PubMed

Bodini, Benedetta; Cercignani, Mara; Khaleeli, Zhaleh; Miller, David H; Ron, Maria; Penny, Sophie; Thompson, Alan J; Ciccarelli, Olga

2013-05-01

We aim to identify specific areas of white matter (WM) and grey matter (GM), which predict disability progression and cognitive dysfunction after five years in patients with primary-progressive multiple sclerosis (PPMS). Thirty-two patients with early PPMS were assessed at baseline and after five years on the Expanded Disability Status Scale (EDSS), and EDSS step-changes were calculated. At year five, a subgroup of 25 patients and 31 healthy controls underwent a neuropsychological assessment. Baseline imaging consisted of dual-echo (proton density and T2-weighted), T1-weighted volumetric, and diffusion tensor imaging. Fractional anisotropy (FA) maps were created, and fed into tract-based spatial statistics. To compensate for the potential bias introduced by WM lesions, the T1 volumes underwent a lesion-filling procedure before entering a voxel-based morphometry protocol. To investigate whether FA and GM volume predicted EDSS step-changes over five years and neuropsychological tests scores at five years, voxelwise linear regression analyses were performed. Lower FA in the splenium of the corpus callosum (CC) predicted a greater progression of disability over the follow-up. Lower FA along the entire CC predicted worse verbal memory, attention and speed of information processing, and executive function at five years. GM baseline volume did not predict any clinical variable. Our findings highlight the importance of damage to the interhemispheric callosal pathways in determining physical and cognitive disability in PPMS. Disruption of these pathways, which interconnect motor and cognitive networks between the two hemispheres, may result in a disconnection syndrome that contributes to long-term physical and cognitive disability. Copyright © 2011 Wiley Periodicals, Inc.

IMPACT OF EARLY AND LATE VISUAL DEPRIVATION ON THE STRUCTURE OF THE CORPUS CALLOSUM: A STUDY COMBINING THICKNESS PROFILE WITH SURFACE TENSOR-BASED MORPHOMETRY

PubMed Central

Shi, Jie; Collignon, Olivier; Xu, Liang; Wang, Gang; Kang, Yue; Leporé, Franco; Lao, Yi; Joshi, Anand A.

2015-01-01

Blindness represents a unique model to study how visual experience may shape the development of brain organization. Exploring how the structure of the corpus callosum (CC) reorganizes ensuing visual deprivation is of particular interest due to its important functional implication in vision (e.g. via the splenium of the CC). Moreover, comparing early versus late visually deprived individuals has the potential to unravel the existence of a sensitive period for reshaping the CC structure. Here, we develop a novel framework to capture a complete set of shape differences in the CC between congenitally blind (CB), late blind (LB) and sighted control (SC) groups. The CCs were manually segmented from T1-weighted brain MRI and modeled by 3D tetrahedral meshes. We statistically compared the combination of local area and thickness at each point between subject groups. Differences in area are found using surface tensor-based morphometry; thickness is estimated by tracing the streamlines in the volumetric harmonic field. Group differences were assessed on this combined measure using Hotelling’s T2 test. Interestingly, we observed that the total callosal volume did not differ between the groups. However, our fine-grained analysis reveals significant differences mostly localized around the splenium areas between both blind groups and the sighted group (general effects of blindness) and, importantly, specific dissimilarities between the LB and CB groups, illustrating the existence of a sensitive period for reorganization. The new multivariate statistics also gave better effect sizes for detecting morphometric differences, relative to other statistics. They may boost statistical power for CC morphometric analyses. PMID:25649876

Regional Microstructural and Volumetric Magnetic Resonance Imaging (MRI) Abnormalities in the Corpus Callosum of Neonates With Congenital Heart Defect Undergoing Cardiac Surgery.

PubMed

Hagmann, Cornelia; Singer, Jitka; Latal, Beatrice; Knirsch, Walter; Makki, Malek

2016-03-01

The purpose of the study is to investigate the structural development of the corpus callosum in term neonates with congenital heart defect before and after surgery using diffusion tensor imaging and 3-dimensional T1-weighted magnetic resonance imaging (MRI). We compared parallel and radial diffusions, apparent diffusion coefficient (ADC), fractional anisotropy, and volume of 5 substructures of the corpus callosum: genu, rostral body, body, isthmus, and splenium. Compared to healthy controls, we found a significantly lower volume of the splenium and total corpus callosum and a higher radial diffusion and lower fractional anisotropy in the splenium of patients presurgery; a lower volume in all substructures in the postsurgery group; higher radial diffusion in the rostral body, body, and splenium; and a higher apparent diffusion coefficient in the splenium of postsurgery patients. Similar fractional anisotropy changes in congenital heart defect patients were reported in preterm infants. Our findings in apparent diffusion coefficient in the splenium of these patients (pre and postsurgery) are comparable to findings in preterm neonates with psychomotor delay. Delayed maturation of the isthmus was also reported in preterm infants. © The Author(s) 2015.

Acute alcohol intoxication, diffuse axonal injury and intraventricular bleeding in patients with isolated blunt traumatic brain injury.

PubMed

Matsukawa, Hidetoshi; Shinoda, Masaki; Fujii, Motoharu; Takahashi, Osamu; Murakata, Atsushi; Yamamoto, Daisuke

2013-01-01

The influence of blood alcohol level (BAL) on outcome remains unclear. This study investigated the relationships between BAL, type and number of diffuse axonal injury (DAI), intraventricular bleeding (IVB) and 6-month outcome. This study reviewed 419 patients with isolated blunt traumatic brain injury. First, it compared clinical and radiological characteristics between patients with good recovery and disability. Second, it compared BAL among DAI lesions. Third, it evaluated the correlation between the BAL and severity of IVB, number of DAI and corpus callosum injury lesions. Regardless of BAL, older age, male gender, severe Glasgow Coma Scale score (<9), abnormal pupil, IVB and lesion on genu of corpus callosum were significantly related to disability. There were no significant differences between the BAL and lesions of DAI. Simple regression analysis revealed that there were no significant correlation between BAL and severity of IVB, number of DAI and corpus callosum injury lesions. Acute alcohol intoxication was not associated with type and number of DAI lesion, IVB and disability. This study suggested that a specific type of traumatic lesion, specifically lesion on genu of corpus callosum and IVB, might be more vital for outcome.

Language comprehension in nonspeaking children with severe cerebral palsy: Neuroanatomical substrate?

PubMed

Geytenbeek, Joke J; Oostrom, Kim J; Harlaar, Laurike; Becher, Jules G; Knol, Dirk L; Barkhof, Frederik; Pinto, Pedro S; Vermeulen, R Jeroen

2015-09-01

To identify relations between brain abnormalities and spoken language comprehension, MRI characteristics of 80 nonspeaking children with severe CP were examined. MRI scans were analysed for patterns of brain abnormalities and scored for specific MRI measures: white matter (WM) areas; size of lateral ventricles, WM abnormality/reduction, cysts, subarachnoid space, corpus callosum thinning and grey matter (GM) areas; cortical GM abnormalities, thalamus, putamen, globus pallidus and nucleus caudatus and cerebellar abnormalities. Language comprehension was assessed with a new validated instrument (C-BiLLT). MRI scans of 35 children were classified as a basal ganglia necrosis (BGN) pattern, with damage to central GM areas; in 60% of these children damage to WM areas was also found. MRI scans of 13 children were classified as periventricular leukomalacia (PVL) with little concomitant damage to central GM areas, 13 as malformations and 19 as miscellaneous. Language comprehension was best in children with BGN, followed by malformations and miscellaneous, and was poorest in PVL. Linear regression modelling per pattern group (malformations excluded), with MRI measures as independent variables, revealed that corpus callosum thinning in BGN and parieto-occipital WM reduction in PVL were the most important explanatory factors for poor language comprehension. No MRI measures explained outcomes in language comprehension in the miscellaneous group. Comprehension of spoken language differs between MRI patterns of severe CP. In children with BGN and PVL differences in language comprehension performance is attributed to damage in the WM areas. Language comprehension was most affected in children with WM lesions in the subcortical and then periventricular areas, most characteristic for children with PVL. Copyright © 2015 European Paediatric Neurology Society. Published by Elsevier Ltd. All rights reserved.

Homozygosity mapping and targeted genomic sequencing reveal the gene responsible for cerebellar hypoplasia and quadrupedal locomotion in a consanguineous kindred

PubMed Central

Gulsuner, Suleyman; Tekinay, Ayse Begum; Doerschner, Katja; Boyaci, Huseyin; Bilguvar, Kaya; Unal, Hilal; Ors, Aslihan; Onat, O. Emre; Atalar, Ergin; Basak, A. Nazli; Topaloglu, Haluk; Kansu, Tulay; Tan, Meliha; Tan, Uner; Gunel, Murat; Ozcelik, Tayfun

2011-01-01

The biological basis for the development of the cerebro-cerebellar structures required for posture and gait in humans is poorly understood. We investigated a large consanguineous family from Turkey exhibiting an extremely rare phenotype associated with quadrupedal locomotion, mental retardation, and cerebro-cerebellar hypoplasia, linked to a 7.1-Mb region of homozygosity on chromosome 17p13.1–13.3. Diffusion weighted imaging and fiber tractography of the patients' brains revealed morphological abnormalities in the cerebellum and corpus callosum, in particular atrophy of superior, middle, and inferior peduncles of the cerebellum. Structural magnetic resonance imaging showed additional morphometric abnormalities in several cortical areas, including the corpus callosum, precentral gyrus, and Brodmann areas BA6, BA44, and BA45. Targeted sequencing of the entire homozygous region in three affected individuals and two obligate carriers uncovered a private missense mutation, WDR81 p.P856L, which cosegregated with the condition in the extended family. The mutation lies in a highly conserved region of WDR81, flanked by an N-terminal BEACH domain and C-terminal WD40 beta-propeller domains. WDR81 is predicted to be a transmembrane protein. It is highly expressed in the cerebellum and corpus callosum, in particular in the Purkinje cell layer of the cerebellum. WDR81 represents the third gene, after VLDLR and CA8, implicated in quadrupedal locomotion in humans. PMID:21885617

Larger corpus callosum and reduced orbitofrontal cortex homotopic connectivity in codeine cough syrup-dependent male adolescents and young adults.

PubMed

Qiu, Ying-Wei; Lv, Xiao-Fei; Jiang, Gui-Hua; Su, Huan-Huan; Ma, Xiao-Fen; Tian, Jun-Zhang; Zhuo, Fu-Zhen

2017-03-01

To characterize interhemispheric functional and anatomical connectivity and their relationships with impulsive behaviour in codeine-containing cough syrup (CCS)-dependent male adolescents and young adults. We compared volumes of corpus callosum (CC) and its five subregion and voxel-mirrored homotopic functional connectivity (VMHC) in 33 CCS-dependent male adolescents and young adults and 38 healthy controls, group-matched for age, education and smoking status. Barratt impulsiveness scale (BIS.11) was used to assess participant impulsive behaviour. Abnormal CC subregions and VMHC revealed by group comparison were extracted and correlated with impulsive behaviour and duration of CCS use. We found selective increased mid-posterior CC volume in CCS-dependent male adolescents and young adults and detected decreased homotopic interhemispheric functional connectivity of medial orbitofrontal cortex (OFC). Moreover, impairment of VMHC was associated with the impulsive behaviour and correlated with the duration of CCS abuse in CCS-dependent male adolescents and young adults. These findings reveal CC abnormalities and disruption of interhemispheric homotopic connectivity in CCS-dependent male adolescents and young adults, which provide a novel insight into the impact of interhemispheric disconnectivity on impulsive behaviour in substance addiction pathophysiology. • CCS-dependent individuals (patients) had selective increased volumes of mid-posterior corpus callosum • Patients had attenuated interhemispheric homotopic FC (VMHC) of bilateral orbitofrontal cortex • Impairment of VMHC correlated with impulsive behaviour in patients • Impairment of VMHC correlated with the CCS duration in patients.

Femoral-facial syndrome with malformations in the central nervous system.

PubMed

Leal, Evelia; Macías-Gómez, Nelly; Rodríguez, Lisa; Mercado, F Miguel; Barros-Núñez, Patricio

2003-01-01

The femoral hypoplasia-unusual facies syndrome (FFS) is a very rare association of femoral and facial abnormalities. Maternal diabetes mellitus has been mainly involved as the causal agent. We report the second case of FFS with anomalies in the central nervous system (CNS) including corticosubcortical atrophy, colpocephaly, partial agenesis of corpus callosum, hypoplasia of the falx cerebri and absent septum pellucidum. The psychomotor development has been normal. We propose that the CNS defects observed in these patients are part of the spectrum of abnormalities in the FFS.

Evolutionary history of callose synthases in terrestrial plants with emphasis on proteins involved in male gametophyte development

PubMed Central

Honys, David

2017-01-01

Callose is a plant-specific polysaccharide (β-1,3-glucan) playing an important role in angiosperms in many developmental processes and responses to biotic and abiotic stresses. Callose is synthesised at the plasma membrane of plant cells by callose synthase (CalS) and, among others, represents the main polysaccharide in the callose wall surrounding the tetrads of developing microspores and in the growing pollen tube wall. CalS proteins involvement in spore development is a plesiomorphic feature of terrestrial plants, but very little is known about their evolutionary origin and relationships amongst the members of this protein family. We performed thorough comparative analyses of callose synthase family proteins from major plant lineages to determine their evolutionary history across the plant kingdom. A total of 1211 candidate CalS sequences were identified and compared amongst diverse taxonomic groups of plants, from bryophytes to angiosperms. Phylogenetic analyses identified six main clades of CalS proteins and suggested duplications during the evolution of specialised functions. Twelve family members had previously been identified in Arabidopsis thaliana. We focused on five CalS subfamilies directly linked to pollen function and found that proteins expressed in pollen evolved twice. CalS9/10 and CalS11/12 formed well-defined clades, whereas pollen-specific CalS5 was found within subfamilies that mostly did not express in mature pollen vegetative cell, although were found in sperm cells. Expression of five out of seven mature pollen-expressed CalS genes was affected by mutations in bzip transcription factors. Only three subfamilies, CalS5, CalS10, and CalS11, however, formed monophyletic, mostly conserved clades. The pairs CalS9/CalS10, CalS11/CalS12 and CalS3 may have diverged after angiosperms diversified from lycophytes and bryophytes. Our analysis of fully sequenced plant proteins identified new evolutionary lineages of callose synthase subfamilies and has established a basis for understanding their functional evolution in terrestrial plants. PMID:29131847

NEURONS COMPRISING A HETEROTOPIA INDUCED BY DEVELOPMENTAL HYPOTHYROIDISM ARE BORN LATE IN GESTATION.

EPA Science Inventory

We previously described an abnormal cluster of neurons, a heterotopia, located in the corpus callosum in rat pups born to dams exposed to the goitrogen, propylthiouracil (PTU, Goodman et al., SfN 2004). In this study we determined 1) whether the formation of the heterotopia was u...

Boomerang sign: Clinical significance of transient lesion in splenium of corpus callosum

PubMed Central

Malhotra, Hardeep Singh; Garg, Ravindra Kumar; Vidhate, Mukund R.; Sharma, Pawan Kumar

2012-01-01

Transient signal abnormality in the splenium of corpus callosum on magnetic resonance imaging (MRI) is occasionally encountered in clinical practice. It has been reported in various clinical conditions apart from patients with epilepsy. We describe 4 patients with different etiologies presenting with signal changes in the splenium of corpus callosum. They were diagnosed as having progressive myoclonic epilepsy (case 1), localization-related epilepsy (case 2), hemicrania continua (case 3), and postinfectious parkinsonism (case 4). While three patients had complete involvement of the splenium on diffusion-weighted image (“boomerang sign”), the patient having hemicrania continua showed semilunar involvement (“mini-boomerang”) on T2-weighted and FLAIR image. All the cases had noncontiguous involvement of the splenium. We herein, discuss these cases with transient splenial involvement and stress that such patients do not need aggressive diagnostic and therapeutic interventions. An attempt has been made to review the literature regarding the pathophysiology, etiology, and outcome of such lesions. PMID:22566735

Herbivore-induced callose deposition on the sieve plates of rice: an important mechanism for host resistance.

PubMed

Hao, Peiying; Liu, Caixiang; Wang, Yuanyuan; Chen, Rongzhi; Tang, Ming; Du, Bo; Zhu, Lili; He, Guangcun

2008-04-01

The brown planthopper (Nilaparvata lugens Stål; BPH) is a specialist herbivore on rice (Oryza sativa) that ingests phloem sap from the plant through its stylet mouthparts. Electronic penetration graphs revealed that BPH insects spent more time wandering over plants carrying the resistance genes Bph14 and Bph15, but less time ingesting phloem than they did on susceptible plants. They also showed that their feeding was frequently interrupted. Tests with [(14)C]sucrose showed that insects ingested much less phloem sap from the resistant than the susceptible plants. BPH feeding up-regulated callose synthase genes and induced callose deposition in the sieve tubes at the point where the stylet was inserted. The compact callose remained intact in the resistant plants, but genes encoding beta-1,3-glucanases were activated, causing unplugging of the sieve tube occlusions in susceptible plants. Continuing ingestion led to a remarkable reduction in the susceptible plants' sucrose content and activation of the RAmy3D gene, leading to starch hydrolysis and ultimately carbohydrate deprivation in the plants. Our results demonstrate that BPH feeding induces the deposition of callose on sieve plates in rice and that this is an important defense mechanism that prevents insects from ingesting phloem sap. In response, however, the BPH can unplug sieve tube occlusions by activating beta-1,3-glucanase genes in rice plants.

Reduced ventral cingulum integrity and increased behavioral problems in children with isolated optic nerve hypoplasia and mild to moderate or no visual impairment.

PubMed

Webb, Emma A; O'Reilly, Michelle A; Clayden, Jonathan D; Seunarine, Kiran K; Dale, Naomi; Salt, Alison; Clark, Chris A; Dattani, Mehul T

2013-01-01

To assess the prevalence of behavioral problems in children with isolated optic nerve hypoplasia, mild to moderate or no visual impairment, and no developmental delay. To identify white matter abnormalities that may provide neural correlates for any behavioral abnormalities identified. Eleven children with isolated optic nerve hypoplasia (mean age 5.9 years) underwent behavioral assessment and brain diffusion tensor imaging, Twenty four controls with isolated short stature (mean age 6.4 years) underwent MRI, 11 of whom also completed behavioral assessments. Fractional anisotropy images were processed using tract-based spatial statistics. Partial correlation between ventral cingulum, corpus callosum and optic radiation fractional anisotropy, and child behavioral checklist scores (controlled for age at scan and sex) was performed. Children with optic nerve hypoplasia had significantly higher scores on the child behavioral checklist (p<0.05) than controls (4 had scores in the clinically significant range). Ventral cingulum, corpus callosum and optic radiation fractional anisotropy were significantly reduced in children with optic nerve hypoplasia. Right ventral cingulum fractional anisotropy correlated with total and externalising child behavioral checklist scores (r = -0.52, p<0.02, r = -0.46, p<0.049 respectively). There were no significant correlations between left ventral cingulum, corpus callosum or optic radiation fractional anisotropy and behavioral scores. Our findings suggest that children with optic nerve hypoplasia and mild to moderate or no visual impairment require behavioral assessment to determine the presence of clinically significant behavioral problems. Reduced structural integrity of the ventral cingulum correlated with behavioral scores, suggesting that these white matter abnormalities may be clinically significant. The presence of reduced fractional anisotropy in the optic radiations of children with mild to moderate or no visual impairment raises questions as to the pathogenesis of these changes which will need to be addressed by future studies.

Adolescent toluene inhalation in rats affects white matter maturation with the potential for recovery following abstinence.

PubMed

Duncan, Jhodie Rubina; Dick, Alec Lindsay Ward; Egan, Gary; Kolbe, Scott; Gavrilescu, Maria; Wright, David; Lubman, Dan Ian; Lawrence, Andrew John

2012-01-01

Inhalant misuse is common during adolescence, with ongoing chronic misuse associated with neurobiological and cognitive abnormalities. While human imaging studies consistently report white matter abnormalities among long-term inhalant users, longitudinal studies have been lacking with limited data available regarding the progressive nature of such abnormalities, including the potential for recovery following periods of sustained abstinence. We exposed adolescent male Wistar rats (postnatal day 27) to chronic intermittent inhaled toluene (3,000 ppm) for 1 hour/day, 3 times/week for 8 weeks to model abuse patterns observed in adolescent and young adult human users. This dosing regimen resulted in a significant retardation in weight gain during the exposure period (p<0.05). In parallel, we performed longitudinal magnetic resonance imaging (T₂-weighted) and diffusion tensor imaging prior to exposure, and after 4 and 8 weeks, to examine the integrity of white matter tracts, including the anterior commissure and corpus callosum. We also conducted imaging after 8 weeks of abstinence to assess for potential recovery. Chronic intermittent toluene exposure during adolescence and early adulthood resulted in white matter abnormalities, including a decrease in axial (p<0.05) and radial (p<0.05) diffusivity. These abnormalities appeared region-specific, occurring in the anterior commissure but not the corpus callosum and were not present until after at least 4 weeks of exposure. Toluene-induced effects on both body weight and white matter parameters recovered following abstinence. Behaviourally, we observed a progressive decrease in rearing activity following toluene exposure but no difference in motor function, suggesting cognitive function may be more sensitive to the effects of toluene. Furthermore, deficits in rearing were present by 4 weeks suggesting that toluene may affect behaviour prior to detectable white matter abnormalities. Consequently, exposure to inhalants that contain toluene during adolescence and early adulthood appear to differentially affect white matter maturation and behavioural outcomes, although recovery can occur following abstinence.

Adolescent Toluene Inhalation in Rats Affects White Matter Maturation with the Potential for Recovery Following Abstinence

PubMed Central

Egan, Gary; Kolbe, Scott; Gavrilescu, Maria; Wright, David; Lubman, Dan Ian; Lawrence, Andrew John

2012-01-01

Inhalant misuse is common during adolescence, with ongoing chronic misuse associated with neurobiological and cognitive abnormalities. While human imaging studies consistently report white matter abnormalities among long-term inhalant users, longitudinal studies have been lacking with limited data available regarding the progressive nature of such abnormalities, including the potential for recovery following periods of sustained abstinence. We exposed adolescent male Wistar rats (postnatal day 27) to chronic intermittent inhaled toluene (3,000 ppm) for 1 hour/day, 3 times/week for 8 weeks to model abuse patterns observed in adolescent and young adult human users. This dosing regimen resulted in a significant retardation in weight gain during the exposure period (p<0.05). In parallel, we performed longitudinal magnetic resonance imaging (T2-weighted) and diffusion tensor imaging prior to exposure, and after 4 and 8 weeks, to examine the integrity of white matter tracts, including the anterior commissure and corpus callosum. We also conducted imaging after 8 weeks of abstinence to assess for potential recovery. Chronic intermittent toluene exposure during adolescence and early adulthood resulted in white matter abnormalities, including a decrease in axial (p<0.05) and radial (p<0.05) diffusivity. These abnormalities appeared region-specific, occurring in the anterior commissure but not the corpus callosum and were not present until after at least 4 weeks of exposure. Toluene-induced effects on both body weight and white matter parameters recovered following abstinence. Behaviourally, we observed a progressive decrease in rearing activity following toluene exposure but no difference in motor function, suggesting cognitive function may be more sensitive to the effects of toluene. Furthermore, deficits in rearing were present by 4 weeks suggesting that toluene may affect behaviour prior to detectable white matter abnormalities. Consequently, exposure to inhalants that contain toluene during adolescence and early adulthood appear to differentially affect white matter maturation and behavioural outcomes, although recovery can occur following abstinence. PMID:23028622

Hemispheric connectivity and the visual-spatial divergent-thinking component of creativity.

PubMed

Moore, Dana W; Bhadelia, Rafeeque A; Billings, Rebecca L; Fulwiler, Carl; Heilman, Kenneth M; Rood, Kenneth M J; Gansler, David A

2009-08-01

Divergent thinking is an important measurable component of creativity. This study tested the postulate that divergent thinking depends on large distributed inter- and intra-hemispheric networks. Although preliminary evidence supports increased brain connectivity during divergent thinking, the neural correlates of this characteristic have not been entirely specified. It was predicted that visuospatial divergent thinking would correlate with right hemisphere white matter volume (WMV) and with the size of the corpus callosum (CC). Volumetric magnetic resonance imaging (MRI) analyses and the Torrance Tests of Creative Thinking (TTCT) were completed among 21 normal right-handed adult males. TTCT scores correlated negatively with the size of the CC and were not correlated with right or, incidentally, left WMV. Although these results were not predicted, perhaps, as suggested by Bogen and Bogen (1988), decreased callosal connectivity enhances hemispheric specialization, which benefits the incubation of ideas that are critical for the divergent-thinking component of creativity, and it is the momentary inhibition of this hemispheric independence that accounts for the illumination that is part of the innovative stage of creativity. Alternatively, decreased CC size may reflect more selective developmental pruning, thereby facilitating efficient functional connectivity.

Size Matters: Cerebral Volume Influences Sex Differences in Neuroanatomy

PubMed Central

Towler, Stephen; Welcome, Suzanne; Halderman, Laura K.; Otto, Ron; Eckert, Mark A.; Chiarello, Christine

2008-01-01

Biological and behavioral differences between the sexes range from obvious to subtle or nonexistent. Neuroanatomical differences are particularly controversial, perhaps due to the implication that they might account for behavioral differences. In this sample of 200 men and women, large effect sizes (Cohen's d > 0.8) were found for sex differences in total cerebral gray and white matter, cerebellum, and gray matter proportion (women had a higher proportion of gray matter). The only one of these sex differences that survived adjustment for the effect of cerebral volume was gray matter proportion. Individual differences in cerebral volume accounted for 21% of the difference in gray matter proportion, while sex accounted for an additional 4%. The relative size of the corpus callosum was 5% larger in women, but this difference was completely explained by a negative relationship between relative callosal size and cerebral volume. In agreement with Jancke et al., individuals with higher cerebral volume tended to have smaller corpora callosa. There were few sex differences in the size of structures in Broca's and Wernicke's area. We conclude that individual differences in brain volume, in both men and women, account for apparent sex differences in relative size. PMID:18440950

Shifting brain asymmetry: the link between meditation and structural lateralization

PubMed Central

Kurth, Florian; MacKenzie-Graham, Allan; Toga, Arthur W.

2015-01-01

Previous studies have revealed an increased fractional anisotropy and greater thickness in the anterior parts of the corpus callosum in meditation practitioners compared with control subjects. Altered callosal features may be associated with an altered inter-hemispheric integration and the degree of brain asymmetry may also be shifted in meditation practitioners. Therefore, we investigated differences in gray matter asymmetry as well as correlations between gray matter asymmetry and years of meditation practice in 50 long-term meditators and 50 controls. We detected a decreased rightward asymmetry in the precuneus in meditators compared with controls. In addition, we observed that a stronger leftward asymmetry near the posterior intraparietal sulcus was positively associated with the number of meditation practice years. In a further exploratory analysis, we observed that a stronger rightward asymmetry in the pregenual cingulate cortex was negatively associated with the number of practice years. The group difference within the precuneus, as well as the positive correlations with meditation years in the pregenual cingulate cortex, suggests an adaptation of the default mode network in meditators. The positive correlation between meditation practice years and asymmetry near the posterior intraparietal sulcus may suggest that meditation is accompanied by changes in attention processing. PMID:24643652

Corpus callosum differences assessed by fetal MRI in late-onset intrauterine growth restriction and its association with neurobehavior.

PubMed

Egaña-Ugrinovic, Gabriela; Sanz-Cortés, Magdalena; Couve-Pérez, Constanza; Figueras, Francesc; Gratacós, Eduard

2014-09-01

The aim of this study is to evaluate corpus callosum (CC) development by Magnetic Resonance Imaging (MRI) in late-onset intrauterine growth restricted (IUGR) fetuses compared to appropriate for gestational age and its association with neurobehavioral outcome. One hundred and seventeen late-onset IUGR and 73 control fetuses were imaged using a 3T MRI scanner at term, obtaining T2 half-Fourier acquisition single-shot turbo spin-echo anatomical slices. CC length, thickness, total area and the areas after a subdivision in 7 portions were assessed. Neonatal Behavioral Assessment Scale test was performed on IUGR newborns at 42 ± 1 weeks. IUGR fetuses showed significantly smaller CC (Total CC Area IUGR: 1.3996 ± 0.26 vs. AGA: 1.664 ± 0.31; p < 0.01) and smaller subdivision areas as compared with controls. The differences were slightly more pronounced in fetuses with very low birth weight and/or abnormal brain and/or abnormal uterine Doppler. CC measurements were significantly associated with neurobehavioral outcome in IUGR cases. CC development was significantly altered in late-onset IUGR fetuses and correlated with worse neurobehavioral performance. CC could be further explored as a potential imaging biomarker to predict abnormal neurodevelopment in pregnancies at risk. © 2014 John Wiley & Sons, Ltd.

Brain MRI and MR Spectroscopy Findings in Children with Nutritional Vitamin B12 Deficiency.

PubMed

Ekici, F; Tekbas, G; Hattapoğlu, S; Yaramış, A; Önder, H; Bilici, A

2016-06-01

Our aim in this study was to analyze the findings of brain magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) of children with vitamin B12 deficiency. This study included 14 cases. The findings of brain MRI and MRS in all cases were investigated. Four patients had been followed up and mean follow-up time 71.8 (59-85) day. Eight patients of the cases (57 %) had at least one abnormal MRI finding. The most commonly found MRI findings were thinning of the corpus callosum and brain atrophy, respectively. The mean ratio of NAA/Cr and Cho/Cr were measured in MRS, with values of 1.31 ± 0.17 and 1.04 ± 0.27, respectively. In two of three patients with abnormal MRI studies at presentation, subsequent MRI showed improvement while one patient remained unchanged. An increase in the ratios of metabolites were found in one case with control MRS. There was no lactate peak. Brain MRI was abnormal in more than half of the cases of children with vitamin B12 deficiency. Our radiologic findings similar with literature. There was no identifiable lactate peak. B12 deficiency could be the cause of the thinning of the corpus callosum and brain atrophy in the children that were given a brain MRI.

Clinical, cognitive, and behavioural correlates of white matter damage in progressive supranuclear palsy.

PubMed

Agosta, Federica; Galantucci, Sebastiano; Svetel, Marina; Lukić, Milica Ječmenica; Copetti, Massimiliano; Davidovic, Kristina; Tomić, Aleksandra; Spinelli, Edoardo G; Kostić, Vladimir S; Filippi, Massimo

2014-05-01

White matter (WM) tract alterations were assessed in patients with progressive supranuclear palsy (PSP) relative to healthy controls and patients with idiopathic Parkinson's disease (PD) to explore the relationship of WM tract damage with clinical disease severity, performance on cognitive tests, and apathy. 37 PSP patients, 41 PD patients, and 34 healthy controls underwent an MRI scan and clinical testing to evaluate physical disability, cognitive impairment, and apathy. In PSP, the contribution of WM tract damage to global disease severity and cognitive and behavioural disturbances was assessed using Random Forest analysis. Relative to controls, PSP patients showed diffusion tensor (DT) MRI abnormalities of the corpus callosum, superior cerebellar peduncle (SCP), cingulum and uncinate fasciculus bilaterally, and right inferior longitudinal fasciculus. Corpus callosum and SCP DT MRI measures distinguished PSP from PD patients with high accuracy (area under the curve ranging from 0.89 to 0.72). In PSP, DT MRI metrics of the corpus callosum and superior cerebellar peduncles were the best predictors of global disease severity scale scores. DT MRI metrics of the corpus callosum, right superior longitudinal and inferior longitudinal fasciculus, and left uncinate were the best predictors of executive dysfunction. In PSP, apathy severity was related to the damage to the corpus callosum, right superior longitudinal, and uncinate fasciculi. In conclusion, WM tract damage contributes to the motor, cognitive, and behavioural deficits in PSP. DT MRI offers markers for PSP diagnosis, assessment, and monitoring.

Agnosia, apraxia, callosal disconnection and other specific cognitive disorders.

PubMed

Acciarresi, Monica

2012-01-01

Cortical function deficits have long been studied by anatomoclinic correlations. Recent functional imaging studies have allowed scientists to better understand which cerebral areas and which networks are involved in cognitive function deficit. This chapter will review the current knowledge on agnosia, apraxia and callosal disconnection syndromes. Copyright © 2012 S. Karger AG, Basel.

Low sociability is associated with reduced size of the corpus callosum in the BALB/cJ inbred mouse strain.

PubMed

Fairless, Andrew H; Dow, Holly C; Toledo, Monica M; Malkus, Kristen A; Edelmann, Michele; Li, Hongzhe; Talbot, Konrad; Arnold, Steven E; Abel, Ted; Brodkin, Edward S

2008-09-16

The behavioral manifestations of autism, including reduced sociability (reduced tendency to seek social interaction), may be related to underdevelopment of the corpus callosum (CC). The BALB/cJ inbred mouse strain is a useful model system for testing the relationship between reduced sociability and CC underdevelopment. BALB/cJ mice show low levels of sociability, on average, but substantial intrastrain variability in sociability, as well as striking variability in CC development. This study tested the hypothesis that sociability is positively correlated with CC size within the BALB/cJ inbred strain. 30-day-old BALB/cJ and C57BL/6J mice were tested for sociability towards gonadectomized A/J stimulus mice in a social choice task. The size of the corpus callosum was measured histologically at the midsagittal plane. BALB/cJ mice showed a significant positive correlation between the tendency to sniff the stimulus mouse and size of the CC relative to brain weight. C57BL/6J mice showed consistently high levels of sociability and normal corpus callosum development. These results suggest that abnormal white matter structure is associated with deficits in sociability in BALB/cJ mice. Additional studies are warranted to elucidate the relationship between brain connectivity and sociability in this model system.

Megasporogenesis and programmed cell death in Tillandsia (Bromeliaceae).

PubMed

Papini, Alessio; Mosti, Stefano; Milocani, Eva; Tani, Gabriele; Di Falco, Pietro; Brighigna, Luigi

2011-10-01

The degeneration of three of four meiotic products is a very common process in the female gender of oogamous eukaryotes. In Tillandsia (and many other angiosperms), the surviving megaspore has a callose-free wall in chalazal position while the other three megaspores are completely embedded in callose. Therefore, nutrients and signals can reach more easily the functional megaspore from the nucellus through the chalazal pole with respect to the other megaspores. The abortion of three of four megaspores was already recognized as the result of a programmed cell death (PCD) process. We investigated the process to understand the modality of this specific type of PCD and its relationship to the asymmetric callose deposition around the tetrad. The decision on which of the four megaspores will be the supernumerary megaspores in angiosperms, and hence destined to undergo programmed cell death, appears to be linked to the callose layer deposition around the tetrad. During supernumerary megaspores degeneration, events leading to the deletion of the cells do not appear to belong to a single type of cell death. The first morphological signs are typical of autophagy, including the formation of autophagosomes. The TUNEL positivity and a change in morphology of mitochondria and chloroplasts indicate the passage to an apoptotic-like PCD phase, while the cellular remnants undergo a final process resembling at least partially (ER swelling) necrotic morphological syndromes, eventually leading to a mainly lipidic cell corpse still separated from the functional megaspore by a callose layer.

EPG5-related Vici syndrome: a paradigm of neurodevelopmental disorders with defective autophagy.

PubMed

Byrne, Susan; Jansen, Lara; U-King-Im, Jean-Marie; Siddiqui, Ata; Lidov, Hart G W; Bodi, Istvan; Smith, Luke; Mein, Rachael; Cullup, Thomas; Dionisi-Vici, Carlo; Al-Gazali, Lihadh; Al-Owain, Mohammed; Bruwer, Zandre; Al Thihli, Khalid; El-Garhy, Rana; Flanigan, Kevin M; Manickam, Kandamurugu; Zmuda, Erik; Banks, Wesley; Gershoni-Baruch, Ruth; Mandel, Hanna; Dagan, Efrat; Raas-Rothschild, Annick; Barash, Hila; Filloux, Francis; Creel, Donnell; Harris, Michael; Hamosh, Ada; Kölker, Stefan; Ebrahimi-Fakhari, Darius; Hoffmann, Georg F; Manchester, David; Boyer, Philip J; Manzur, Adnan Y; Lourenco, Charles Marques; Pilz, Daniela T; Kamath, Arveen; Prabhakar, Prab; Rao, Vamshi K; Rogers, R Curtis; Ryan, Monique M; Brown, Natasha J; McLean, Catriona A; Said, Edith; Schara, Ulrike; Stein, Anja; Sewry, Caroline; Travan, Laura; Wijburg, Frits A; Zenker, Martin; Mohammed, Shehla; Fanto, Manolis; Gautel, Mathias; Jungbluth, Heinz

2016-03-01

Vici syndrome is a progressive neurodevelopmental multisystem disorder due to recessive mutations in the key autophagy gene EPG5. We report genetic, clinical, neuroradiological, and neuropathological features of 50 children from 30 families, as well as the neuronal phenotype of EPG5 knock-down in Drosophila melanogaster. We identified 39 different EPG5 mutations, most of them truncating and predicted to result in reduced EPG5 protein. Most mutations were private, but three recurrent mutations (p.Met2242Cysfs*5, p.Arg417*, and p.Gln336Arg) indicated possible founder effects. Presentation was mainly neonatal, with marked hypotonia and feeding difficulties. In addition to the five principal features (callosal agenesis, cataracts, hypopigmentation, cardiomyopathy, and immune dysfunction), we identified three equally consistent features (profound developmental delay, progressive microcephaly, and failure to thrive). The manifestation of all eight of these features has a specificity of 97%, and a sensitivity of 89% for the presence of an EPG5 mutation and will allow informed decisions about genetic testing. Clinical progression was relentless and many children died in infancy. Survival analysis demonstrated a median survival time of 24 months (95% confidence interval 0-49 months), with only a 10th of patients surviving to 5 years of age. Survival outcomes were significantly better in patients with compound heterozygous mutations (P = 0.046), as well as in patients with the recurrent p.Gln336Arg mutation. Acquired microcephaly and regression of skills in long-term survivors suggests a neurodegenerative component superimposed on the principal neurodevelopmental defect. Two-thirds of patients had a severe seizure disorder, placing EPG5 within the rapidly expanding group of genes associated with early-onset epileptic encephalopathies. Consistent neuroradiological features comprised structural abnormalities, in particular callosal agenesis and pontine hypoplasia, delayed myelination and, less frequently, thalamic signal intensity changes evolving over time. Typical muscle biopsy features included fibre size variability, central/internal nuclei, abnormal glycogen storage, presence of autophagic vacuoles and secondary mitochondrial abnormalities. Nerve biopsy performed in one case revealed subtotal absence of myelinated axons. Post-mortem examinations in three patients confirmed neurodevelopmental and neurodegenerative features and multisystem involvement. Finally, downregulation of epg5 (CG14299) in Drosophila resulted in autophagic abnormalities and progressive neurodegeneration. We conclude that EPG5-related Vici syndrome defines a novel group of neurodevelopmental disorders that should be considered in patients with suggestive features in whom mitochondrial, glycogen, or lysosomal storage disorders have been excluded. Neurological progression over time indicates an intriguing link between neurodevelopment and neurodegeneration, also supported by neurodegenerative features in epg5-deficient Drosophila, and recent implication of other autophagy regulators in late-onset neurodegenerative disease. © The Author (2016). Published by Oxford University Press on behalf of the Guarantors of Brain.

EPG5-related Vici syndrome: a paradigm of neurodevelopmental disorders with defective autophagy

PubMed Central

Byrne, Susan; Jansen, Lara; U-King-Im, Jean-Marie; Siddiqui, Ata; Lidov, Hart G. W.; Bodi, Istvan; Smith, Luke; Mein, Rachael; Cullup, Thomas; Dionisi-Vici, Carlo; Al-Gazali, Lihadh; Al-Owain, Mohammed; Bruwer, Zandre; Al Thihli, Khalid; El-Garhy, Rana; Flanigan, Kevin M.; Manickam, Kandamurugu; Zmuda, Erik; Banks, Wesley; Gershoni-Baruch, Ruth; Mandel, Hanna; Dagan, Efrat; Raas-Rothschild, Annick; Barash, Hila; Filloux, Francis; Creel, Donnell; Harris, Michael; Hamosh, Ada; Kölker, Stefan; Ebrahimi-Fakhari, Darius; Hoffmann, Georg F.; Manchester, David; Boyer, Philip J.; Manzur, Adnan Y.; Lourenco, Charles Marques; Pilz, Daniela T.; Kamath, Arveen; Prabhakar, Prab; Rao, Vamshi K.; Rogers, R. Curtis; Ryan, Monique M.; Brown, Natasha J.; McLean, Catriona A.; Said, Edith; Schara, Ulrike; Stein, Anja; Sewry, Caroline; Travan, Laura; Wijburg, Frits A.; Zenker, Martin; Mohammed, Shehla; Fanto, Manolis; Gautel, Mathias

2016-01-01

Vici syndrome is a progressive neurodevelopmental multisystem disorder due to recessive mutations in the key autophagy gene EPG5. We report genetic, clinical, neuroradiological, and neuropathological features of 50 children from 30 families, as well as the neuronal phenotype of EPG5 knock-down in Drosophila melanogaster. We identified 39 different EPG5 mutations, most of them truncating and predicted to result in reduced EPG5 protein. Most mutations were private, but three recurrent mutations (p.Met2242Cysfs*5, p.Arg417*, and p.Gln336Arg) indicated possible founder effects. Presentation was mainly neonatal, with marked hypotonia and feeding difficulties. In addition to the five principal features (callosal agenesis, cataracts, hypopigmentation, cardiomyopathy, and immune dysfunction), we identified three equally consistent features (profound developmental delay, progressive microcephaly, and failure to thrive). The manifestation of all eight of these features has a specificity of 97%, and a sensitivity of 89% for the presence of an EPG5 mutation and will allow informed decisions about genetic testing. Clinical progression was relentless and many children died in infancy. Survival analysis demonstrated a median survival time of 24 months (95% confidence interval 0–49 months), with only a 10th of patients surviving to 5 years of age. Survival outcomes were significantly better in patients with compound heterozygous mutations (P = 0.046), as well as in patients with the recurrent p.Gln336Arg mutation. Acquired microcephaly and regression of skills in long-term survivors suggests a neurodegenerative component superimposed on the principal neurodevelopmental defect. Two-thirds of patients had a severe seizure disorder, placing EPG5 within the rapidly expanding group of genes associated with early-onset epileptic encephalopathies. Consistent neuroradiological features comprised structural abnormalities, in particular callosal agenesis and pontine hypoplasia, delayed myelination and, less frequently, thalamic signal intensity changes evolving over time. Typical muscle biopsy features included fibre size variability, central/internal nuclei, abnormal glycogen storage, presence of autophagic vacuoles and secondary mitochondrial abnormalities. Nerve biopsy performed in one case revealed subtotal absence of myelinated axons. Post-mortem examinations in three patients confirmed neurodevelopmental and neurodegenerative features and multisystem involvement. Finally, downregulation of epg5 (CG14299) in Drosophila resulted in autophagic abnormalities and progressive neurodegeneration. We conclude that EPG5-related Vici syndrome defines a novel group of neurodevelopmental disorders that should be considered in patients with suggestive features in whom mitochondrial, glycogen, or lysosomal storage disorders have been excluded. Neurological progression over time indicates an intriguing link between neurodevelopment and neurodegeneration, also supported by neurodegenerative features in epg5-deficient Drosophila, and recent implication of other autophagy regulators in late-onset neurodegenerative disease. PMID:26917586

[Structural change of the corpus callosum fibers in toddlers with autism spectrum disorder: two-year follow-up].

PubMed

Chang, C; Qiu, N N; Xiao, T; Xiao, X; Chu, K K; Li, Y; Wu, Q R; Fang, H; Ke, X Y

2017-12-02

Objective: To conduct a follow-up investigation of structural changes of the corpus callosum fibers of toddlers (2 to 5 years of age) with autism spectrum disorder(ASD) and to explore the associations with clinical symptoms. Method: In this prospective randomized controlled study, ASD children who were diagnosed in the Child Mental Health Research Center, Nanjing Brain Hospital Affiliated to Nanjing Medical University from May 2011 to November 2012 were included in the ASD group, and developmentally delayed children were included in the control group (DD group). Diffusion tensor imaging (DTI) data from the two groups were obtained at two age levels: 2-3 years of age, and 4-5 years of age. Region of interest analysis was applied to assess characteristic values of total area and sub-regions of corpus callosum: the fraction anisotropy (FA), the mean diffusivity (MD), the radial diffusivity (RD) and the axial diffusivity (AD). All children were assessed using the Autism Diagnostic Interview-Revised (ADI-R) and Autism Treatment Evaluation Checklist (ATEC). The characteristic values of total area and sub-regions of corpus callosum of ASD group at two age levels were analyzed by paired sample t test; the characteristic values of total area and sub-regions of corpus callosum of ASD group and DD group were analyzed by independent-sample t test; the correlations between FA values of the total area and sub-regions of corpus callosum and ADI-R or ATEC scores were analyzed by Pearson correlation analysis. Result: Forty cases meeting inclusion criteria were enrolled in ASD group, and 31 eligible cases were enrolled in the control group. Four children in the ASD group were lost to follow-up, and 5 children in the control group were lost to follow-up. Longitudinal comparison between the two age subgroups of ASD patients showed that the FA values of the total corpus callosum increased (0.499 55±0.027 59 vs . 0.505 83±0.086 64, t= 4.88, P <0.05), but MD values, RD values and AD values of the total corpus callosum area decreased (0.000 89±0.000 03 vs . 0.000 81±0.000 14, 0.000 61±0.000 04 vs. 0.000 55±0.000 09, 0.001 43±0.000 03 vs . 0.001 38±0.000 03, t= 9.31, 7.90, 8.66, P <0.05 for all comparisons). In the area of corpus callosum genu, FA and AD values increased ( t= 5.59, 8.48, P <0.05 for both comparisons), but MD and RD values decreased ( t= 12.67, 11.28, P <0.05 for both comparisns). In the area of corpus callosum body, FA and RD values increased( t= 5.46, 8.48, P <0.05 for both comparisons), but MD and AD values decreased ( t= 8.08, 6.22, P <0.05 for both comparisons). In the area of corpus callosum splenium, MD, RD and AD values decreased ( t= 6.81, 4.44, 5.51, P < 0.05 for all comparisons). Among the participants 2 to 3 years of age, there were no significantly differences in FA values of total area and sub-regions of corpus callosum between ASD group and the DD group ( P > 0.05 for all comparisons); as compared with the DD group, ASD group had higher AD values of total area and splenium of corpus callosum (0.001 43±0.000 03 vs . 0.001 40±0.000 04, 0.001 34±0.000 03 vs . 0.001 32±0.000 04, t= 1.56, 1.14, P < 0.05 for both comparisons); ASD group had lower AD values but higher RD and MD values of corpus callosum genu ( t= 0.07, 0.55, 0.07, P < 0.05 for all comparisons); ASD group had lower RD values of corpus callosum body ( t= 0.07, P < 0.05). Among the participants 4 to 5 years of age, as compared with the DD group, ASD group had higher FA value of total corpus callosum area(0.505 83±0.086 64 vs . 0.483 77±0.099 30, t= 8.56, P < 0.05), lower RD value of total corpus callosum(0.000 55±0.000 09 vs . 0.000 56±0.000 12, t= 14.44, P < 0.05), lower RD values of corpus callosum body ( t= 2.20, P < 0.05), higher FA values ( t= 3.35, P < 0.05) but lower AD values of corpus callosum splenium ( t= 2.20, P < 0.05). A correlation analysis between FA values of total area and sub-regions of corpus callosum and clinical variables showed that the FA values of total area and splenium of corpus callosum in ASD group at 2 to 3 years of age were negatively correlated with the scores of language skills in ATEC ( r=- 0.35,-0.36, P < 0.05 for both comparisons). And after two years, FA values of total corpus callosum were positively correlated with the scores of social communication in ATEC ( r= 0.34, P < 0.05). There was no significant correlation between FA values of sub-regions of corpus callosum and the scores of ATEC ( P > 0.05 for all comparisons). There was no significant correlation between FA values of total area and sub-regions of corpus callosum and the scores of ADI-R ( P > 0.05 for all comparisons). Conclusion: The fiber structure of corpus callosum was still in the process of maturing during the age of 2 to 5 years; however, compared with DD group, ASD group had more extensive structural abnormalities of the corpus callosum fibers as age increased, and the structural abnormalities had correlation with the core symptoms of ASD. Trial registration Chinese Clinical Trial Registry, ChiCTR-OPC-17011995.

Convergence of Cortical, Thalamocortical, and Callosal Pathways during Human Fetal Development Revealed by Diffusion MRI Tractography.

PubMed

Wang, Rongpin; Wilkinson, Molly; Kane, Tara; Takahashi, Emi

2017-01-01

There has been evidence that during brain development, emerging thalamocortical (TC) and corticothalamic (CT) pathways converge in some brain regions and follow each other's trajectories to their final destinations. Corpus callosal (CC) pathways also emerge at a similar developmental stage, and are known to converge with TC pathways in specific cortical regions in mature brains. Given the functional relationships between TC and CC pathways, anatomical convergence of the two pathways are likely important for their functional integration. However, it is unknown (1) where TC and CT subcortically converge in the human brain, and (2) where TC and CC converge in the cortex of the human brain, due to the limitations of non-invasive methods. The goals of this study were to describe the spatio-temporal relationships in the development of the TC/CT and CC pathways in the human brain, using high-angular resolution diffusion MR imaging (HARDI) tractography. Emerging cortical, TC and CC pathways were identified in postmortem fetal brains ranging from 17 gestational weeks (GW) to 30 GW, as well as in vivo 34-40 GW newborns. Some pathways from the thalami were found to be converged with pathways from the cerebral cortex as early as 17 GW. Such convergence was observed mainly in anterior and middle regions of the brain until 21 GW. At 22 GW and onwards, posterior pathways from the thalami also converged with cortical pathways. Many CC pathways reached the full length up to the cortical surface as early as 17 GW, while pathways linked to thalami (not only TC axons but also including pathways linked to thalamic neuronal migration) reached the cortical surface at and after 20 GW. These results suggest that CC pathways developed earlier than the TC pathways. The two pathways were widespread at early stages, but by 40 GW they condensed and formed groups of pathways that projected to specific regions of the cortex and overlapped in some brain regions. These results suggest that HARDI tractography has the potential to identify developing TC/CT and CC pathways with the timing and location of their convergence in fetal stages persisting in postnatal development.

Convergence of Cortical, Thalamocortical, and Callosal Pathways during Human Fetal Development Revealed by Diffusion MRI Tractography

PubMed Central

Wang, Rongpin; Wilkinson, Molly; Kane, Tara; Takahashi, Emi

2017-01-01

There has been evidence that during brain development, emerging thalamocortical (TC) and corticothalamic (CT) pathways converge in some brain regions and follow each other's trajectories to their final destinations. Corpus callosal (CC) pathways also emerge at a similar developmental stage, and are known to converge with TC pathways in specific cortical regions in mature brains. Given the functional relationships between TC and CC pathways, anatomical convergence of the two pathways are likely important for their functional integration. However, it is unknown (1) where TC and CT subcortically converge in the human brain, and (2) where TC and CC converge in the cortex of the human brain, due to the limitations of non-invasive methods. The goals of this study were to describe the spatio-temporal relationships in the development of the TC/CT and CC pathways in the human brain, using high-angular resolution diffusion MR imaging (HARDI) tractography. Emerging cortical, TC and CC pathways were identified in postmortem fetal brains ranging from 17 gestational weeks (GW) to 30 GW, as well as in vivo 34–40 GW newborns. Some pathways from the thalami were found to be converged with pathways from the cerebral cortex as early as 17 GW. Such convergence was observed mainly in anterior and middle regions of the brain until 21 GW. At 22 GW and onwards, posterior pathways from the thalami also converged with cortical pathways. Many CC pathways reached the full length up to the cortical surface as early as 17 GW, while pathways linked to thalami (not only TC axons but also including pathways linked to thalamic neuronal migration) reached the cortical surface at and after 20 GW. These results suggest that CC pathways developed earlier than the TC pathways. The two pathways were widespread at early stages, but by 40 GW they condensed and formed groups of pathways that projected to specific regions of the cortex and overlapped in some brain regions. These results suggest that HARDI tractography has the potential to identify developing TC/CT and CC pathways with the timing and location of their convergence in fetal stages persisting in postnatal development. PMID:29163000

The transcription factor Nfix is essential for normal brain development.

PubMed

Campbell, Christine E; Piper, Michael; Plachez, Céline; Yeh, Yu-Ting; Baizer, Joan S; Osinski, Jason M; Litwack, E David; Richards, Linda J; Gronostajski, Richard M

2008-05-13

The Nuclear Factor I (NFI) multi-gene family encodes site-specific transcription factors essential for the development of a number of organ systems. We showed previously that Nfia-deficient mice exhibit agenesis of the corpus callosum and other forebrain defects; Nfib-deficient mice have defects in lung maturation and show callosal agenesis and forebrain defects resembling those seen in Nfia-deficient animals, while Nfic-deficient mice have defects in tooth root formation. Recently the Nfix gene has been disrupted and these studies indicated that there were largely uncharacterized defects in brain and skeletal development in Nfix-deficient mice. Here we show that disruption of Nfix by Cre-recombinase mediated excision of the 2nd exon results in defects in brain development that differ from those seen in Nfia and Nfib KO mice. In particular, complete callosal agenesis is not seen in Nfix-/- mice but rather there appears to be an overabundance of aberrant Pax6- and doublecortin-positive cells in the lateral ventricles of Nfix-/- mice, increased brain weight, expansion of the cingulate cortex and entire brain along the dorsal ventral axis, and aberrant formation of the hippocampus. On standard lab chow Nfix-/- animals show a decreased growth rate from ~P8 to P14, lose weight from ~P14 to P22 and die at ~P22. If their food is supplemented with a soft dough chow from P10, Nfix-/- animals show a lag in weight gain from P8 to P20 but then increase their growth rate. A fraction of the animals survive to adulthood and are fertile. The weight loss correlates with delayed eye and ear canal opening and suggests a delay in the development of several epithelial structures in Nfix-/- animals. These data show that Nfix is essential for normal brain development and may be required for neural stem cell homeostasis. The delays seen in eye and ear opening and the brain morphology defects appear independent of the nutritional deprivation, as rescue of perinatal lethality with soft dough does not eliminate these defects.

Corpus callosum volumes in the 5 years following the first-episode of schizophrenia: Effects of antipsychotics, chronicity and maturation.

PubMed

de Moura, Mariana T M; Zanetti, Marcus V; Duran, Fabio L S; Schaufelberger, Maristela S; Menezes, Paulo R; Scazufca, Marcia; Busatto, Geraldo F; Serpa, Mauricio H

2018-01-01

White matter (WM) structural changes, particularly affecting the corpus callosum (CC), seem to be critically implicated in psychosis. Whether such abnormalities are progressive or static is still a matter of debate in schizophrenia research. Aberrant maturation processes might also influence the longitudinal trajectory of age-related CC changes in schizophrenia patients. We investigated whether patients with first-episode schizophrenia-related psychoses (FESZ) would present longitudinal CC and whole WM volume changes over the 5 years after disease onset. Thirty-two FESZ patients and 34 controls recruited using a population-based design completed a 5-year assessment protocol, including structural MRI scanning at baseline and follow-up. The linear effects of disease duration, clinical outcome and antipsychotic (AP) use over time on WM and CC volumes were studied using both voxelwise and volume-based morphometry analyses. We also examined maturation/aging abnormalities through cross-sectional analyses of age-related trajectories of total WM and CC volume changes. No interaction between diagnosis and time was observed, and clinical outcome did not influence CC volumes in patients. On the other hand, FESZ patients continuously exposed to AP medication showed volume increase over time in posterior CC. Curve-estimation analyses revealed a different aging pattern in FESZ patients versus controls: while patients displayed a linear decline of total WM and anterior CC volumes with age, a non-linear trajectory of total WM and relative preservation of CC volumes were observed in controls. Continuous AP exposure can influence CC morphology during the first years after schizophrenia onset. Schizophrenia is associated with an abnormal pattern of total WM and anterior CC aging during non-elderly adulthood, and this adds complexity to the discussion on the static or progressive nature of structural abnormalities in psychosis.

Importance of correctly interpreting magnetic resonance imaging to diagnose posterior reversible encephalopathy syndrome associated with HELLP syndrome: a case report.

PubMed

Tetsuka, Syuichi; Nonaka, Hiroaki

2017-05-25

Severe haemolysis, elevated liver enzyme levels, and low platelet count (HELLP) syndrome in pregnancy are possible underlying trigger factors for posterior reversible encephalopathy syndrome (PRES). Magnetic resonance imaging (MRI) shows diffuse signal abnormalities involving the subcortical white matter in the parieto-occipital lobes. Although the diagnosis of RPES was clearly established by the distinctive reversibility of clinical and radiological abnormalities, it is difficult to distinguish from differential diagnosis. Thus, it is important to correctly interpret MRI. We describe a case of HELLP syndrome with PRES. A 38-year-old pregnant woman was admitted to our hospital as an emergency case with a complaint of upper abdominal pain and headache at 29 weeks of pregnancy and the development of HELLP syndrome. An emergency caesarean section was immediately performed. After the operation, the patient received intravenous corticosteroids, and her blood pressure was controlled. Thereafter, she showed an altered mental status. MRI showed hypersignal intense lesions in the cortical and subcortical white matter in the occipital lobes, basal ganglia and callosal splenium in both the fluid-attenuated inversion recovery (FLAIR) sequence and apparent diffusion coefficient (ADC), but these lesions were not recognized in diffusion-weighted imaging (DWI). These images were suggestive of PRES. The patient was kept in the hospital and received the appropriate treatment, after which the patient's level of consciousness improved and all laboratory tests and imaging examinations returned normal. The MRI findings were useful for the prompt diagnosis of PRES, characterized by hypersignals in FLAIR and ADC, but not in DWI. Additionally, there was an "atypical" MRI appearance of basal ganglial and callosal splenial involvement in this case, which may mistakenly lead clinicians to diagnose other aetiologies than typical PRES. It is considered that vasogenic oedema is the main pathology of PRES according to the MRI image findings. MRI is the gold standard for diagnosing PRES because it can provide information about cerebral involvement earlier than CT; further, it can be a useful tool in the differential diagnosis. This technique facilitated the prompt diagnosis and treatment of the said patient, ultimately resulting in a good outcome.

Callosally projecting neurons in the macaque monkey V1/V2 border are enriched in nonphosphorylated neurofilament protein

NASA Technical Reports Server (NTRS)

Hof, P. R.; Ungerleider, L. G.; Adams, M. M.; Webster, M. J.; Gattass, R.; Blumberg, D. M.; Morrison, J. H.; Bloom, F. E. (Principal Investigator)

1997-01-01

Previous immunohistochemical studies combined with retrograde tracing in macaque monkeys have demonstrated that corticocortical projections can be differentiated by their content of neurofilament protein. The present study analyzed the distribution of nonphosphorylated neurofilament protein in callosally projecting neurons located at the V1/V2 border. All of the retrogradely labeled neurons were located in layer III at the V1/V2 border and at an immediately adjacent zone of area V2. A quantitative analysis showed that the vast majority (almost 95%) of these interhemispheric projection neurons contain neurofilament protein immunoreactivity. This observation differs from data obtained in other sets of callosal connections, including homotypical interhemispheric projections in the prefrontal, temporal, and parietal association cortices, that were found to contain uniformly low proportions of neurofilament protein-immunoreactive neurons. Comparably, highly variable proportions of neurofilament protein-containing neurons have been reported in intrahemispheric corticocortical pathways, including feedforward and feedback visual connections. These results indicate that neurofilament protein is a prominent neurochemical feature that identifies a particular population of interhemispheric projection neurons at the V1/V2 border and suggest that this biochemical attribute may be critical for the function of this subset of callosal neurons.

Early white matter abnormalities, progressive brain pathology and motor deficits in a novel knock-in mouse model of Huntington's disease

PubMed Central

Jin, Jing; Peng, Qi; Hou, Zhipeng; Jiang, Mali; Wang, Xin; Langseth, Abraham J.; Tao, Michael; Barker, Peter B.; Mori, Susumu; Bergles, Dwight E.; Ross, Christopher A.; Detloff, Peter J.; Zhang, Jiangyang; Duan, Wenzhen

2015-01-01

White matter abnormalities have been reported in premanifest Huntington's disease (HD) subjects before overt striatal neuronal loss, but whether the white matter changes represent a necessary step towards further pathology and the underlying mechanism of these changes remains unknown. Here, we characterized a novel knock-in mouse model that expresses mouse HD gene homolog (Hdh) with extended CAG repeat- HdhQ250, which was derived from the selective breeding of HdhQ150 mice. HdhQ250 mice manifest an accelerated and robust phenotype compared with its parent line. HdhQ250 mice exhibit progressive motor deficits, reduction in striatal and cortical volume, accumulation of mutant huntingtin aggregation, decreased levels of DARPP32 and BDNF and altered striatal metabolites. The abnormalities detected in this mouse model are reminiscent of several aspects of human HD. In addition, disturbed myelination was evident in postnatal Day 14 HdhQ250 mouse brain, including reduced levels of myelin regulatory factor and myelin basic protein, and decreased numbers of myelinated axons in the corpus callosum. Thinner myelin sheaths, indicated by increased G-ratio of myelin, were also detected in the corpus callosum of adult HdhQ250 mice. Moreover, proliferation of oligodendrocyte precursor cells is altered by mutant huntingtin both in vitro and in vivo. Our data indicate that this model is suitable for understanding comprehensive pathogenesis of HD in white matter and gray matter as well as developing therapeutics for HD. PMID:25609071

Correlation between morphological MRI findings and specific diagnostic categories in fetal alcohol spectrum disorders.

PubMed

Boronat, S; Sánchez-Montañez, A; Gómez-Barros, N; Jacas, C; Martínez-Ribot, L; Vázquez, E; Del Campo, M

2017-01-01

Fetal alcohol spectrum disorders (FASD) include physical and neurodevelopmental abnormalities related to prenatal alcohol exposure. Some neuroimaging findings have been clearly related to FASD, including corpus callosum and cerebellar anomalies. However, detailed studies correlating with specific FASD categories, that is, the fetal alcohol syndrome (FAS), partial FAS (pFAS) and alcohol related neurodevelopmental disorders (ARND), are lacking. We prospectively performed clinical assessment and brain MR imaging to 72 patients with suspected FASD, and diagnosis was confirmed in 62. The most frequent findings were hypoplasia of the corpus callosum and/or of the cerebellar vermis. Additional findings were vascular anomalies, gliosis, prominent perivascular spaces, occipito-cervical junction and cervical vertebral anomalies, pituitary hypoplasia, arachnoid cysts, and cavum septum pellucidum. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

White matter microstructural abnormalities in the frontal lobe of adults with antisocial personality disorder.

PubMed

Sundram, Frederick; Deeley, Quinton; Sarkar, Sagari; Daly, Eileen; Latham, Richard; Craig, Michael; Raczek, Malgorzata; Fahy, Tom; Picchioni, Marco; Barker, Gareth J; Murphy, Declan G M

2012-02-01

Antisocial personality disorder (ASPD) and psychopathy involve significant interpersonal and behavioural impairments. However, little is known about their underlying neurobiology and in particular, abnormalities in white matter (WM) microstructure. A preliminary diffusion tensor magnetic resonance imaging (DT-MRI) study of adult psychopaths employing tractography revealed abnormalities in the right uncinate fasciculus (UF) (Craig et al., 2009), indicating fronto-limbic disconnectivity. However, it is not clear whether WM abnormalities are restricted to this tract or are or more widespread, including other tracts which are involved in connectivity with the frontal lobe. We performed whole brain voxel-based analyses on WM fractional anisotropy (FA) and mean diffusivity (MD) maps acquired with DT-MRI to compare 15 adults with ASPD and healthy age, handedness and IQ-matched controls. Also, within ASPD subjects we related differences in FA and MD to measures of psychopathy. Significant WM FA reduction and MD increases were found respectively in ASPD subjects relative to controls. FA was bilaterally reduced in the genu of corpus callosum while in the right frontal lobe FA reduction was found in the UF, inferior fronto-occipital fasciculus (IFOF), anterior corona radiata and anterior limb and genu of the internal capsule. These differences negatively correlated with measures of psychopathy. Also in the right frontal lobe, increased MD was found in the IFOF and UF, and the corpus callosum and anterior corona radiata. There was a significant positive correlation between MD and psychopathy scores. The present study confirms a previous report of reduced FA in the UF. Additionally, we report for the first time, FA deficits in tracts involved in interhemispheric as well as frontal lobe connectivity in conjunction with MD increases in the frontal lobe. Hence, we provide evidence of significant WM microstructural abnormalities in frontal brain regions in ASPD and psychopathy. Copyright © 2011 Elsevier Srl. All rights reserved.

Brain abnormalities in murderers indicated by positron emission tomography.

PubMed

Raine, A; Buchsbaum, M; LaCasse, L

1997-09-15

Murderers pleading not guilty by reason of insanity (NGRI) are thought to have brain dysfunction, but there have been no previous studies reporting direct measures of both cortical and subcortical brain functioning in this specific group. Positron emission tomography brain imaging using a continuous performance challenge task was conducted on 41 murderers pleading not guilty by reason of insanity and 41 age- and sex-matched controls. Murderers were characterized by reduced glucose metabolism in the prefrontal cortex, superior parietal gyrus, left angular gyrus, and the corpus callosum, while abnormal asymmetries of activity (left hemisphere lower than right) were also found in the amygdala, thalamus, and medial temporal lobe. These preliminary findings provide initial indications of a network of abnormal cortical and subcortical brain processes that may predispose to violence in murderers pleading NGRI.

Local differentiation of cell wall matrix polysaccharides in sinuous pavement cells: its possible involvement in the flexibility of cell shape.

PubMed

Sotiriou, P; Giannoutsou, E; Panteris, E; Galatis, B; Apostolakos, P

2018-03-01

The distribution of homogalacturonans (HGAs) displaying different degrees of esterification as well as of callose was examined in cell walls of mature pavement cells in two angiosperm and two fern species. We investigated whether local cell wall matrix differentiation may enable pavement cells to respond to mechanical tension forces by transiently altering their shape. HGA epitopes, identified with 2F4, JIM5 and JIM7 antibodies, and callose were immunolocalised in hand-made or semithin leaf sections. Callose was also stained with aniline blue. The structure of pavement cells was studied with light and transmission electron microscopy (TEM). In all species examined, pavement cells displayed wavy anticlinal cell walls, but the waviness pattern differed between angiosperms and ferns. The angiosperm pavement cells were tightly interconnected throughout their whole depth, while in ferns they were interconnected only close to the external periclinal cell wall and intercellular spaces were developed between them close to the mesophyll. Although the HGA epitopes examined were located along the whole cell wall surface, the 2F4- and JIM5- epitopes were especially localised at cell lobe tips. In fern pavement cells, the contact sites were impregnated with callose and JIM5-HGA epitopes. When tension forces were applied on leaf regions, the pavement cells elongated along the stretching axis, due to a decrease in waviness of anticlinal cell walls. After removal of tension forces, the original cell shape was resumed. The presented data support that HGA epitopes make the anticlinal pavement cell walls flexible, in order to reversibly alter their shape. Furthermore, callose seems to offer stability to cell contacts between pavement cells, as already suggested in photosynthetic mesophyll cells. © 2017 German Society for Plant Sciences and The Royal Botanical Society of the Netherlands.

Frequency of brain MRI abnormalities in neuromyelitis optica spectrum disorder at presentation: A cohort of Latin American patients.

PubMed

Carnero Contentti, Edgar; Daccach Marques, Vanessa; Soto de Castillo, Ibis; Tkachuk, Veronica; Antunes Barreira, Amilton; Armas, Elizabeth; Chiganer, Edson; de Aquino Cruz, Camila; Di Pace, José Luis; Hryb, Javier Pablo; Lavigne Moreira, Carolina; Lessa, Carmen; Molina, Omaira; Perassolo, Monica; Soto, Arnoldo; Caride, Alejandro

2018-01-01

Brain magnetic resonance imaging (BMRI) lesions were classically not reported in neuromyelitis optica (NMO). However, BMRI lesions are not uncommon in NMO spectrum disorder (NMOSD) patients. To report BMRI characteristic abnormalities (location and configuration) in NMOSD patients at presentation. Medical records and BMRI characteristics of 79 patients with NMOSD (during the first documented attack) in Argentina, Brazil and Venezuela were reviewed retrospectively. BMRI abnormalities were observed in 81.02% of NMOSD patients at presentation. Forty-two patients (53.1%) showed typical-NMOSD abnormalities. We found BMRI abnormalities at presentation in the brainstem/cerebellum (n = 26; 32.9%), optic chiasm (n = 16; 20.2%), area postrema (n = 13; 16.4%), thalamus/hypothalamus (n = 11; 13.9%), corpus callosum (n = 11; 13.9%), periependymal-third ventricle (n = 9; 11.3%), corticospinal tract (n = 7; 8.8%), hemispheric white matter (n = 1; 1.2%) and nonspecific areas (n = 49; 62.03%). Asymptomatic BMRI lesions were more common. The frequency of brain MRI abnormalities did not differ between patients who were positive and negative for aquaporin 4 antibodies at presentation. Typical brain MRI abnormalities are frequent in NMOSD at disease onset. Copyright © 2017 Elsevier B.V. All rights reserved.

Mirror writing ability is genetic and probably transmitted as a sex-linked dominant trait: it is hypothesised that mirror writers have bilateral language centres with a callosal interconnection.

PubMed

Mathewson, Iain

2004-01-01

Mirror writing is the ability to write from right to left, reversing each letter so that when held to a mirror the script appears normal. There is no information on the prevalence of this trait but a suggestion was received that it may be hereditary. A newspaper survey was carried out to discover the approximate prevalence and whether a hereditary factor is involved. The results indicated a prevalence of 1 in 6500. There is strong evidence that the trait is hereditary and is associated with non-right-handedness'. It is hypothesised that mirror writers may comprise a very small group of people who not only have bilateral language centres but also have an interconnecting pathway between these centres via the corpus callosum. The surprising genetic nature of a trait with no obvious evolutionary consequences is discussed. The data can best be explained on the basis of the trait being the phenotypic expression of an X-linked dominant gene, which does have evolutionary consequences. Similarities are noted between the proposed genetics of mirror writing and those of synaesthesia and of a few pathological X-linked dominant syndromes such as Rett syndrome. Other similarities and contrasts between mirror writing and synaesthesia are noted.

Layer 5 Callosal Parvalbumin-Expressing Neurons: A Distinct Functional Group of GABAergic Neurons

PubMed Central

Zurita, Hector; Feyen, Paul L. C.; Apicella, Alfonso Junior

2018-01-01

Previous studies have shown that parvalbumin-expressing neurons (CC-Parv neurons) connect the two hemispheres of motor and sensory areas via the corpus callosum, and are a functional part of the cortical circuit. Here we test the hypothesis that layer 5 CC-Parv neurons possess anatomical and molecular mechanisms which dampen excitability and modulate the gating of interhemispheric inhibition. In order to investigate this hypothesis we use viral tracing to determine the anatomical and electrophysiological properties of layer 5 CC-Parv and parvalbumin-expressing (Parv) neurons of the mouse auditory cortex (AC). Here we show that layer 5 CC-Parv neurons had larger dendritic fields characterized by longer dendrites that branched farther from the soma, whereas layer 5 Parv neurons had smaller dendritic fields characterized by shorter dendrites that branched nearer to the soma. The layer 5 CC-Parv neurons are characterized by delayed action potential (AP) responses to threshold currents, lower firing rates, and lower instantaneous frequencies compared to the layer 5 Parv neurons. Kv1.1 containing K+ channels are the main source of the AP repolarization of the layer 5 CC-Parv and have a major role in determining both the spike delayed response, firing rate and instantaneous frequency of these neurons. PMID:29559891

Layer 5 Callosal Parvalbumin-Expressing Neurons: A Distinct Functional Group of GABAergic Neurons.

PubMed

Zurita, Hector; Feyen, Paul L C; Apicella, Alfonso Junior

2018-01-01

Previous studies have shown that parvalbumin-expressing neurons (CC-Parv neurons) connect the two hemispheres of motor and sensory areas via the corpus callosum, and are a functional part of the cortical circuit. Here we test the hypothesis that layer 5 CC-Parv neurons possess anatomical and molecular mechanisms which dampen excitability and modulate the gating of interhemispheric inhibition. In order to investigate this hypothesis we use viral tracing to determine the anatomical and electrophysiological properties of layer 5 CC-Parv and parvalbumin-expressing (Parv) neurons of the mouse auditory cortex (AC). Here we show that layer 5 CC-Parv neurons had larger dendritic fields characterized by longer dendrites that branched farther from the soma, whereas layer 5 Parv neurons had smaller dendritic fields characterized by shorter dendrites that branched nearer to the soma. The layer 5 CC-Parv neurons are characterized by delayed action potential (AP) responses to threshold currents, lower firing rates, and lower instantaneous frequencies compared to the layer 5 Parv neurons. Kv1.1 containing K + channels are the main source of the AP repolarization of the layer 5 CC-Parv and have a major role in determining both the spike delayed response, firing rate and instantaneous frequency of these neurons.

Shifting brain asymmetry: the link between meditation and structural lateralization.

PubMed

Kurth, Florian; MacKenzie-Graham, Allan; Toga, Arthur W; Luders, Eileen

2015-01-01

Previous studies have revealed an increased fractional anisotropy and greater thickness in the anterior parts of the corpus callosum in meditation practitioners compared with control subjects. Altered callosal features may be associated with an altered inter-hemispheric integration and the degree of brain asymmetry may also be shifted in meditation practitioners. Therefore, we investigated differences in gray matter asymmetry as well as correlations between gray matter asymmetry and years of meditation practice in 50 long-term meditators and 50 controls. We detected a decreased rightward asymmetry in the precuneus in meditators compared with controls. In addition, we observed that a stronger leftward asymmetry near the posterior intraparietal sulcus was positively associated with the number of meditation practice years. In a further exploratory analysis, we observed that a stronger rightward asymmetry in the pregenual cingulate cortex was negatively associated with the number of practice years. The group difference within the precuneus, as well as the positive correlations with meditation years in the pregenual cingulate cortex, suggests an adaptation of the default mode network in meditators. The positive correlation between meditation practice years and asymmetry near the posterior intraparietal sulcus may suggest that meditation is accompanied by changes in attention processing. © The Author (2014). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

Independent and Collaborative Contributions of the Cerebral Hemispheres to Emotional Processing

PubMed Central

Shobe, Elizabeth R.

2014-01-01

Presented is a model suggesting that the right hemisphere (RH) directly mediates the identification and comprehension of positive and negative emotional stimuli, whereas the left hemisphere (LH) contributes to higher level processing of emotional information that has been shared via the corpus callosum. RH subcortical connections provide initial processing of emotional stimuli, and their innervation to cortical structures provides a secondary pathway by which the hemispheres process emotional information more fully. It is suggested that the LH contribution to emotion processing is in emotional regulation, social well-being, and adaptation, and transforming the RH emotional experience into propositional and verbal codes. Lastly, it is proposed that the LH has little ability at the level of emotion identification, having a default positive bias and no ability to identify a stimulus as negative. Instead, the LH must rely on the transfer of emotional information from the RH to engage higher-order emotional processing. As such, either hemisphere can identify positive emotions, but they must collaborate for complete processing of negative emotions. Evidence presented draws from behavioral, neurological, and clinical research, including discussions of subcortical and cortical pathways, callosal agenesis, commissurotomy, emotion regulation, mood disorders, interpersonal interaction, language, and handedness. Directions for future research are offered. PMID:24795597

Lipid Peroxidation Is an Early Symptom Triggered by Aluminum, But Not the Primary Cause of Elongation Inhibition in Pea Roots1

PubMed Central

Yamamoto, Yoko; Kobayashi, Yukiko; Matsumoto, Hideaki

2001-01-01

Pea (Pisum sativum) roots were treated with aluminum in a calcium solution, and lipid peroxidation was investigated histochemically and biochemically, as well as other events caused by aluminum exposure. Histochemical stainings were observed to distribute similarly on the entire surface of the root apex for three events (aluminum accumulation, lipid peroxidation, and callose production), but the loss of plasma membrane integrity (detected by Evans blue uptake) was localized exclusively at the periphery of the cracks on the surface of root apex. The enhancement of four events (aluminum accumulation, lipid peroxidation, callose production, and root elongation inhibition) displayed similar aluminum dose dependencies and occurred by 4 h. The loss of membrane integrity, however, was enhanced at lower aluminum concentrations and after longer aluminum exposure (8 h). The addition of butylated hydroxyanisole (a lipophilic antioxidant) during aluminum treatment completely prevented lipid peroxidation and callose production by 40%, but did not prevent or slow the other events. Thus lipid peroxidation is a relatively early symptom induced by the accumulation of aluminum and appears to cause, in part, callose production, but not the root elongation inhibition; by comparison, the loss of plasma membrane integrity is a relatively late symptom caused by cracks in the root due to the inhibition of root elongation. PMID:11154329

Hexanoic Acid Treatment Prevents Systemic MNSV Movement in Cucumis melo Plants by Priming Callose Deposition Correlating SA and OPDA Accumulation.

PubMed

Fernández-Crespo, Emma; Navarro, Jose A; Serra-Soriano, Marta; Finiti, Iván; García-Agustín, Pilar; Pallás, Vicente; González-Bosch, Carmen

2017-01-01

Unlike fungal and bacterial diseases, no direct method is available to control viral diseases. The use of resistance-inducing compounds can be an alternative strategy for plant viruses. Here we studied the basal response of melon to Melon necrotic spot virus (MNSV) and demonstrated the efficacy of hexanoic acid (Hx) priming, which prevents the virus from systemically spreading. We analysed callose deposition and the hormonal profile and gene expression at the whole plant level. This allowed us to determine hormonal homeostasis in the melon roots, cotyledons, hypocotyls, stems and leaves involved in basal and hexanoic acid-induced resistance (Hx-IR) to MNSV. Our data indicate important roles of salicylic acid (SA), 12-oxo-phytodienoic acid (OPDA), jasmonic-isoleucine, and ferulic acid in both responses to MNSV. The hormonal and metabolites balance, depending on the time and location associated with basal and Hx-IR, demonstrated the reprogramming of plant metabolism in MNSV-inoculated plants. The treatment with both SA and OPDA prior to virus infection significantly reduced MNSV systemic movement by inducing callose deposition. This demonstrates their relevance in Hx-IR against MNSV and a high correlation with callose deposition. Our data also provide valuable evidence to unravel priming mechanisms by natural compounds.

Hexanoic Acid Treatment Prevents Systemic MNSV Movement in Cucumis melo Plants by Priming Callose Deposition Correlating SA and OPDA Accumulation

PubMed Central

Fernández-Crespo, Emma; Navarro, Jose A.; Serra-Soriano, Marta; Finiti, Iván; García-Agustín, Pilar; Pallás, Vicente; González-Bosch, Carmen

2017-01-01

Unlike fungal and bacterial diseases, no direct method is available to control viral diseases. The use of resistance-inducing compounds can be an alternative strategy for plant viruses. Here we studied the basal response of melon to Melon necrotic spot virus (MNSV) and demonstrated the efficacy of hexanoic acid (Hx) priming, which prevents the virus from systemically spreading. We analysed callose deposition and the hormonal profile and gene expression at the whole plant level. This allowed us to determine hormonal homeostasis in the melon roots, cotyledons, hypocotyls, stems and leaves involved in basal and hexanoic acid-induced resistance (Hx-IR) to MNSV. Our data indicate important roles of salicylic acid (SA), 12-oxo-phytodienoic acid (OPDA), jasmonic-isoleucine, and ferulic acid in both responses to MNSV. The hormonal and metabolites balance, depending on the time and location associated with basal and Hx-IR, demonstrated the reprogramming of plant metabolism in MNSV-inoculated plants. The treatment with both SA and OPDA prior to virus infection significantly reduced MNSV systemic movement by inducing callose deposition. This demonstrates their relevance in Hx-IR against MNSV and a high correlation with callose deposition. Our data also provide valuable evidence to unravel priming mechanisms by natural compounds. PMID:29104580

Magnetic resonance imaging spectrum of succinate dehydrogenase-related infantile leukoencephalopathy.

PubMed

Helman, Guy; Caldovic, Ljubica; Whitehead, Matthew T; Simons, Cas; Brockmann, Knut; Edvardson, Simon; Bai, Renkui; Moroni, Isabella; Taylor, J Michael; Van Haren, Keith; Taft, Ryan J; Vanderver, Adeline; van der Knaap, Marjo S

2016-03-01

Succinate dehydrogenase-deficient leukoencephalopathy is a complex II-related mitochondrial disorder for which the clinical phenotype, neuroimaging pattern, and genetic findings have not been comprehensively reviewed. Nineteen individuals with succinate dehydrogenase deficiency-related leukoencephalopathy were reviewed for neuroradiological, clinical, and genetic findings as part of institutional review board-approved studies at Children's National Health System (Washington, DC) and VU University Medical Center (Amsterdam, the Netherlands). All individuals had signal abnormalities in the central corticospinal tracts and spinal cord where imaging was available. Other typical findings were involvement of the cerebral hemispheric white matter with sparing of the U fibers, the corpus callosum with sparing of the outer blades, the basis pontis, middle cerebellar peduncles, and cerebellar white matter, and elevated succinate on magnetic resonance spectroscopy (MRS). The thalamus was involved in most studies, with a predilection for the anterior nucleus, pulvinar, and geniculate bodies. Clinically, infantile onset neurological regression with partial recovery and subsequent stabilization was typical. All individuals had mutations in SDHA, SDHB, or SDHAF1, or proven biochemical defect. Succinate dehydrogenase deficiency is a rare leukoencephalopathy, for which improved recognition by magnetic resonance imaging (MRI) in combination with advanced sequencing technologies allows noninvasive diagnostic confirmation. The MRI pattern is characterized by cerebral hemispheric white matter abnormalities with sparing of the U fibers, corpus callosum involvement with sparing of the outer blades, and involvement of corticospinal tracts, thalami, and spinal cord. In individuals with infantile regression and this pattern of MRI abnormalities, the differential diagnosis should include succinate dehydrogenase deficiency, in particular if MRS shows elevated succinate. © 2016 American Neurological Association.

[Ocular coloboma and results of brain MRI: preliminary results].

PubMed

Denis, D; Girard, N; Levy-Mozziconacci, A; Berbis, J; Matonti, F

2013-03-01

Congenital ocular colobomas are the result of a failure in closure of the embryonal fissure. We present a prospective study (2007-2011) in which we report brain MRI findings in children with ocular coloboma. Thirty-five children (54 eyes) were included; 15 boys, 20 girls with a median age of 24.0 months (1.0-96.0) at first presentation. Within 2 to 3 months following complete ophthalmologic examination, brain MRI was performed. Colobomas were bilateral in 19 cases and unilateral in 16 cases. Eleven different types of coloboma were identified. Of 54 eyes, 74% demonstrated optic nerve coloboma, of which 28 were severe. Of 35 MRI's performed, abnormalities were present in 86%: gyration abnormalities (n=21), lateral ventricular dilatation (n=17), dilatation of the Virchow-Robin and subarachnoid spaces (n=14), signal abnormalities and brain stem malformations (n=14), white matter signal abnormalities (n=11), corpus callosum abnormalities (n=10). Most of these abnormalities were related. Gyration abnormalities were the most frequent. There was no significant association between the severity of the coloboma and the abnormalities found (P=1.0). Likewise, there was no significant association of gyration abnormalities with the severity of coloboma in children (P=1.0). This study shows, for the first time, the existence of frequent cerebral abnormalities on MRI in children with ocular coloboma. The most common abnormality being gyration abnormalities, in 60% of cases. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

The PTI1-like kinase ZmPti1a from maize (Zea mays L.) co-localizes with callose at the plasma membrane of pollen and facilitates a competitive advantage to the male gametophyte.

PubMed

Herrmann, Markus M; Pinto, Sheena; Kluth, Jantjeline; Wienand, Udo; Lorbiecke, René

2006-10-06

The tomato kinase Pto confers resistance to bacterial speck disease caused by Pseudomonas syringae pv. tomato in a gene for gene manner. Upon recognition of specific avirulence factors the Pto kinase activates multiple signal transduction pathways culminating in induction of pathogen defense. The soluble cytoplasmic serine/threonine kinase Pti1 is one target of Pto phosphorylation and is involved in the hypersensitive response (HR) reaction. However, a clear role of Pti1 in plant pathogen resistance is uncertain. So far, no Pti1 homologues from monocotyledonous species have been studied. Here we report the identification and molecular analysis of four Pti1-like kinases from maize (ZmPti1a, -b, -c, -d). These kinase genes showed tissue-specific expression and their corresponding proteins were targeted to different cellular compartments. Sequence similarity, expression pattern and cellular localization of ZmPti1b suggested that this gene is a putative orthologue of Pti1 from tomato. In contrast, ZmPti1a was specifically expressed in pollen and sequestered to the plasma membrane, evidently owing to N-terminal modification by myristoylation and/or S-acylation. The ZmPti1a:GFP fusion protein was not evenly distributed at the pollen plasma membrane but accumulated as an annulus-like structure which co-localized with callose (1,3-beta-glucan) deposition. In addition, co-localization of ZmPti1a and callose was observed during stages of pollen mitosis I and pollen tube germination. Maize plants in which ZmPti1a expression was silenced by RNA interference (RNAi) produced pollen with decreased competitive ability. Hence, our data provide evidence that ZmPti1a plays an important part in a signalling pathway that accelerates pollen performance and male fitness. ZmPti1a from maize is involved in pollen-specific processes during the progamic phase of reproduction, probably in crucial signalling processes associated with regions of callose deposition. Pollen-sporophyte interactions and pathogen induced HR show certain similarities. For example, HR has been shown to be associated with cell wall reinforcement through callose deposition. Hence, it is hypothesized that Pti1 kinases from maize act as general components in evolutionary conserved signalling processes associated with callose, however during different developmental programs and in different tissue types.

Complete trisomy 9 with unusual phenotypic associations: Dandy-Walker malformation, cleft lip and cleft palate, cardiovascular abnormalities.

PubMed

Tonni, Gabriele; Lituania, Mario; Chitayat, David; Bonasoni, Maria Paola; Keating, Sarah; Thompson, Megan; Shannon, Patrick

2014-12-01

Trisomy 9 is a rare chromosomal abnormality usually associated with first-trimester miscarriage; few fetuses survive until the second trimester. We report two new cases of complete trisomy 9 that both present unusual phenotypic associations, and we analyze the genetic pathway involved in this chromosomal abnormality. The first fetus investigated showed Dandy-Walker malformation, cleft lip, and cleft palate) at the second trimester scan. Cardiovascular abnormalities were characterized by a right-sided, U-shaped aortic arch associated with a ventricular septal defect (VSD). Symmetrical intrauterine growth restriction and multicystic dysplastic kidney disease were associated findings. The second fetus showed a dysmorphic face, bilateral cleft lip, hypoplastic corpus callosum, and a Dandy-Walker malformation. Postmortem examination revealed cardiovascular abnormalities such as persistent left superior vena cava draining into the coronary sinus, membranous ventricular septal defect, overriding aorta, pulmonary valve with two cusps and three sinuses, and the origin of the left subclavian artery distal to the junction of ductus arteriosus and aortic arch. Complete trisomy 9 may result in a wide spectrum of congenital abnormalities, and the presented case series contributes further details on the phenotype of this rare aneuploidy. Copyright © 2014. Published by Elsevier B.V.

A Strategy to Validate the Role of Callose-mediated Plasmodesmal Gating in the Tropic Response.

PubMed

Kumar, Ritesh; Wu, Shu Wei; Iswanto, Arya Bagus Boedi; Kumar, Dhinesh; Han, Xiao; Kim, Jae-Yean

2016-04-17

The plant hormone auxin plays an important role in many growth and developmental processes, including tropic responses to light and gravity. The establishment of an auxin gradient is a key event leading to phototropism and gravitropism. Previously, polar auxin transport (PAT) was shown to establish an auxin gradient in different cellular domains of plants. However, Han et al. recently demonstrated that for proper auxin gradient formation, plasmodesmal callose-mediated symplasmic connectivity between the adjacent cells is also a critical factor. In this manuscript, the strategy to elucidate the role of particular genes, which can affect phototropism and gravitropism by altering the symplasmic connectivity through modulating plasmodesmal callose synthesis, is discussed. The first step is to screen aberrant tropic responses from 3-day-old etiolated seedlings of mutants or over-expression lines of a gene along with the wild type. This preliminary screening can lead to the identification of a range of genes functioning in PAT or controlling symplasmic connectivity. The second screening involves the sorting of candidates that show altered tropic responses by affecting symplasmic connectivity. To address such candidates, the movement of a symplasmic tracer and the deposition of plasmodesmal callose were examined. This strategy would be useful to explore new candidate genes that can regulate symplasmic connectivity directly or indirectly during tropic responses and other developmental processes.

[Cerebral and ocular abnormalities with anterior pituitary insufficiency of familial nature].

PubMed

Weill, J; Boudailliez, B; Piussan, C; Ponte, C

1985-01-01

Three families presenting one or several cases of brain or ophthalmic abnormalities and an hypopituitarism at least by one of the members have been observed. In the first family, the mother and one of her sons present bilateral choroidoretineal coloboma with amblyopia; one of these two suffers as well from panhypopituitarism. In the second family two premature twins, a brother and his sister, present a syndrome with hypophyseal dwarfism and ophthalmic abnormalities, consisting in the boy's case in an peripapillary depigmentation with no visible sight trouble whereas girl's is showing an extreme microphthalmia with major mental retardation. In the third family two 2nd degree cousins present a panhypopituitarism but only one of the two reveals through neuroradiological investigations corpus callosum and septum lucidum agenesia. The karyotype is normal in all the cases. An hereditary mechanism appears clearly in the first family. It is possible in the second, probable in the third one.

Trisomy 8 syndrome owing to isodicentric 8p chromosomes: regional assignment of a presumptive gene involved in corpus callosum development.

PubMed Central

Digilio, M C; Giannotti, A; Floridia, G; Uccellatore, F; Mingarelli, R; Danesino, C; Dallapiccola, B; Zuffardi, O

1994-01-01

Two patients with trisomy 8 syndrome owing to an isodicentric 8p;8p chromosome are described. Case 1 had a 46,XX/46,XX,-8,+idic(8)(p23) karyotype while case 2, a male, had the same abnormal karyotype without evidence of mosaicism. In situ hybridisation, performed in case 1, showed that the isochromosome was asymmetrical. Agenesis of the corpus callosum (ACC), which is a feature of trisomy 8 syndrome, was found in both patients. Although ACC is associated with aneuploidies for different chromosomes, a review of published reports indicates that, when associated with chromosome 8, this defect is the result of duplication of a gene located within 8p21-pter. Molecular analysis in one of our patients led us to exclude the distal 23 Mb of 8p from this ACC region. Images PMID:8014974

Sexually dimorphic white matter geometry abnormalities in adolescent onset schizophrenia.

PubMed

Savadjiev, P; Whitford, T J; Hough, M E; Clemm von Hohenberg, C; Bouix, S; Westin, C-F; Shenton, M E; Crow, T J; James, A C; Kubicki, M

2014-05-01

The normal human brain is characterized by a pattern of gross anatomical asymmetry. This pattern, known as the "torque", is associated with a sexual dimorphism: The male brain tends to be more asymmetric than that of the female. This fact, along with well-known sex differences in brain development (faster in females) and onset of psychosis (earlier with worse outcome in males), has led to the theory that schizophrenia is a disorder in which sex-dependent abnormalities in the development of brain torque, the correlate of the capacity for language, cause alterations in interhemispheric connectivity, which are causally related to psychosis (Crow TJ, Paez P, Chance SE. 2007. Callosal misconnectivity and the sex difference in psychosis. Int Rev Psychiatry. 19(4):449-457.). To provide evidence toward this theory, we analyze the geometry of interhemispheric white matter connections in adolescent-onset schizophrenia, with a particular focus on sex, using a recently introduced framework for white matter geometry computation in diffusion tensor imaging data (Savadjiev P, Kindlmann GL, Bouix S, Shenton ME, Westin CF. 2010. Local white geometry from diffusion tensor gradients. Neuroimage. 49(4):3175-3186.). Our results reveal a pattern of sex-dependent white matter geometry abnormalities that conform to the predictions of Crow's torque theory and correlate with the severity of patients' symptoms. To the best of our knowledge, this is the first study to associate geometrical differences in white matter connectivity with torque in schizophrenia.

Molecular insights into Cassava brown streak virus susceptibility and resistance by profiling of the early host response.

PubMed

Anjanappa, Ravi B; Mehta, Devang; Okoniewski, Michal J; Szabelska-Berȩsewicz, Alicja; Gruissem, Wilhelm; Vanderschuren, Hervé

2018-02-01

Cassava brown streak virus (CBSV) and Ugandan cassava brown streak virus (UCBSV) are responsible for significant cassava yield losses in eastern sub-Saharan Africa. To study the possible mechanisms of plant resistance to CBSVs, we inoculated CBSV-susceptible and CBSV-resistant cassava varieties with a mixed infection of CBSVs using top-cleft grafting. Transcriptome profiling of the two cassava varieties was performed at the earliest time point of full infection (28 days after grafting) in the susceptible scions. The expression of genes encoding proteins in RNA silencing, salicylic acid pathways and callose deposition was altered in the susceptible cassava variety, but transcriptional changes were limited in the resistant variety. In total, the expression of 585 genes was altered in the resistant variety and 1292 in the susceptible variety. Transcriptional changes led to the activation of β-1,3-glucanase enzymatic activity and a reduction in callose deposition in the susceptible cassava variety. Time course analysis also showed that CBSV replication in susceptible cassava induced a strong up-regulation of RDR1, a gene previously reported to be a susceptibility factor in other potyvirus-host pathosystems. The differences in the transcriptional responses to CBSV infection indicated that susceptibility involves the restriction of callose deposition at plasmodesmata. Aniline blue staining of callose deposits also indicated that the resistant variety displays a moderate, but significant, increase in callose deposition at the plasmodesmata. Transcriptome data suggested that resistance does not involve typical antiviral defence responses (i.e. RNA silencing and salicylic acid). A meta-analysis of the current RNA-sequencing (RNA-seq) dataset and selected potyvirus-host and virus-cassava RNA-seq datasets revealed that the conservation of the host response across pathosystems is restricted to genes involved in developmental processes. © 2017 THE AUTHORS. MOLECULAR PLANT PATHOLOGY PUBLISHED BY BRITISH SOCIETY FOR PLANT PATHOLOGY AND JOHN WILEY & SONS LTD.

The Center for Advanced Food Technology: Food Related Studies.

DTIC Science & Technology

1992-11-16

Glucan (Callose) Synthase from Beta Vulgaris L. by Product-Entrapment," Entrapment Mechanisms and Polypeptide Characterization. Elant MU g. 97:684...Na3HGe7O16 xH20, xaO 0-6. 1," Chemiatr of Materials, 4:388. FRost, D.L, Drake, R.R., and B.P. Wasserman (1992) ’(1,3)-- glucan Synthase from Saccbaro...Wu, A., and R.W. Harriman (1992) "Probing the Molecular Architecture of (1,3-- Glucan (Callose) Synthase: Polypeptide Depletion Studies," Biochemical

Cell-to-cell communication via plasmodesmata in vascular plants

PubMed Central

Sevilem, Iris; Miyashima, Shunsuke; Helariutta, Ykä

2013-01-01

In plant development, cell-to-cell signaling is mediated by mobile signals, including transcription factors and small RNA molecules. This communication is essential for growth and patterning. Short-range movement of signals occurs in the extracellular space via the apoplastic pathway or directly from cell-to-cell via the symplastic pathway. Symplastic transport is mediated by plant specific structures called plasmodesmata, which are plasma membrane-lined pores that traverse the cell walls of adjacent cells thus connecting their cytoplasms. However, a thorough understanding of molecules moving via plasmodesmata and regulatory networks relying on symplastic signaling is lacking. Traffic via plasmodesmata is highly regulated, and callose turnover is known to be one mechanism. In Arabidopsis, plasmodesmata apertures can be regulated in a spatially and temporally specific manner with the icals3m, an inducible vector system expressing the mutated CalS3 gene encoding a plasmodesmata localized callose synthase that increases callose deposition at plasmodesmata. We discuss strategies to use the icals3m system for global analyses on symplastic signaling in plants. PMID:23076211

Lipid Raft, Regulator of Plasmodesmal Callose Homeostasis.

PubMed

Iswanto, Arya Bagus Boedi; Kim, Jae-Yean

2017-04-03

A bstract: The specialized plasma membrane microdomains known as lipid rafts are enriched by sterols and sphingolipids. Lipid rafts facilitate cellular signal transduction by controlling the assembly of signaling molecules and membrane protein trafficking. Another specialized compartment of plant cells, the plasmodesmata (PD), which regulates the symplasmic intercellular movement of certain molecules between adjacent cells, also contains a phospholipid bilayer membrane. The dynamic permeability of plasmodesmata (PDs) is highly controlled by plasmodesmata callose (PDC), which is synthesized by callose synthases (CalS) and degraded by β-1,3-glucanases (BGs). In recent studies, remarkable observations regarding the correlation between lipid raft formation and symplasmic intracellular trafficking have been reported, and the PDC has been suggested to be the regulator of the size exclusion limit of PDs. It has been suggested that the alteration of lipid raft substances impairs PDC homeostasis, subsequently affecting PD functions. In this review, we discuss the substantial role of membrane lipid rafts in PDC homeostasis and provide avenues for understanding the fundamental behavior of the lipid raft-processed PDC.

Identification of Eye-Specific Domains and Their Relation to Callosal Connections in Primary Visual Cortex of Long Evans Rats

PubMed Central

Laing, R.J.; Turecek, J.; Takahata, T.; Olavarria, J.F.

2015-01-01

Ocular dominance columns (ODCs) exist in many primates and carnivores, but it is believed that they do not exist in rodents. Using a combination of transneuronal tracing, in situ hybridization for Zif268 and electrophysiological recordings, we show that inputs from both eyes are largely segregated in the binocular region of V1 in Long Evans rats. We also show that, interposed between this binocular region and the lateral border of V1, there lies a strip of cortex that is strongly dominated by the contralateral eye. Finally, we show that callosal connections colocalize primarily with ipsilateral eye domains in the binocular region and with contralateral eye input in the lateral cortical strip, mirroring the relationship between patchy callosal connections and specific sets of ODCs described previously in the cat. Our results suggest that development of cortical modular architecture is more conserved among rodents, carnivores, and primates than previously thought. PMID:24969475

Global gene expression profiles in brain regions reflecting abnormal neuronal and glial functions targeting myelin sheaths after 28-day exposure to cuprizone in rats

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

Abe, Hajime

Both developmental and postpubertal cuprizone (CPZ) exposure impairs hippocampal neurogenesis in rats. We previously found that developmental CPZ exposure alters the expression of genes related to neurogenesis, myelination, and synaptic transmission in specific brain regions of offspring. Here, we examined neuronal and glial toxicity profiles in response to postpubertal CPZ exposure by using expression microarray analysis in the hippocampal dentate gyrus, corpus callosum, cerebral cortex, and cerebellar vermis of 5-week-old male rats exposed to 0, 120, and 600 mg/kg CPZ for 28 days. Genes showing transcript upregulation were subjected to immunohistochemical analysis. We found transcript expression alterations at 600 mg/kgmore » for genes related to synaptic transmission, Ache and Prima1, and cell cycle regulation, Tfap4 and Cdkn1a, in the dentate gyrus, which showed aberrant neurogenesis in the subgranular zone. This dose downregulated myelination-related genes in multiple brain regions, whereas KLOTHO{sup +} oligodendrocyte density was decreased only in the corpus callosum. The corpus callosum showed an increase in transcript levels for inflammatory response-related genes and in the number of CD68{sup +} microglia, MT{sup +} astrocytes, and TUNEL{sup +} apoptotic cells. These results suggest that postpubertal CPZ exposure targets synaptic transmission and cell cycle regulation to affect neurogenesis in the dentate gyrus. CPZ suppressed myelination in multiple brain regions and KLOTHO-mediated oligodendrocyte maturation only in the corpus callosum. The increased number of CD68{sup +} microglia, MT{sup +} astrocytes, and TUNEL{sup +} apoptotic cells in the corpus callosum may be involved in the induction of KLOTHO{sup +} oligodendrocyte death and be a protective mechanism against myelin damage following CPZ exposure. - Highlights: • Target gene expression profiles were examined in rats after 28-day CPZ exposure. • Multiple brain region-specific global gene expression profiling was performed. • CPZ affected synaptic function and cell cycling in the hippocampal dentate gyrus. • CPZ suppressed KLOTHO-mediated oligodendrocyte maturation in the corpus callosum. • CPZ increased metallothionein-mediated protective mechanism against myelin damage.« less

Congenital cerebral malformations and dysfunction in fetuses and newborns following the 2013 to 2014 Zika virus epidemic in French Polynesia.

PubMed

Besnard, Marianne; Eyrolle-Guignot, Dominique; Guillemette-Artur, Prisca; Lastère, Stéphane; Bost-Bezeaud, Frédérique; Marcelis, Ludivine; Abadie, Véronique; Garel, Catherine; Moutard, Marie-Laure; Jouannic, Jean-Marie; Rozenberg, Flore; Leparc-Goffart, Isabelle; Mallet, Henri-Pierre

2016-01-01

We detected an unusual increase in congenital cerebral malformations and dysfunction in fetuses and newborns in French Polynesia, following an epidemic of Zika virus (ZIKV), from October 2013 to March 2014. A retrospective review identified 19 cases, including eight with major brain lesions and severe microcephaly, six with severe cerebral lesions without microcephaly and five with brainstem dysfunction without visible malformations. Imaging revealed profound neurological lesions (septal and callosal disruption, ventriculomegaly, abnormal neuronal migration, cerebellar hypoplasia, occipital pseudocysts, brain calcifications). Amniotic fluid was drawn from seven cases at gestation weeks 20 to 29. ZIKV RNA was detected by RT-PCR and infectious ZIKV isolates were obtained in four of five microcephalic, but not in two non-microcephalic cases with severe brain lesions. Medical termination of pregnancy was performed in eleven cases; two cases with brainstem dysfunction died in the first months of life; six cases are alive, with severe neurological impairment. The results show that four of seven tested fetuses with major neurological injuries were infected with ZIKV in utero. For other non-microcephalic, congenital abnormalities we were not able to prove or exclude ZIKV infection retrospectively. The unusual occurrence of brain malformations or dysfunction without microcephaly following a ZIKV outbreak needs further studies.

Value of brain MRI when sonography raises suspicion of agenesis of the corpus callosum in fetuses.

PubMed

Jarre, A; Llorens Salvador, R; Montoliu Fornas, G; Montoya Filardi, A

To evaluate the role of magnetic resonance imaging (MRI) in fetuses with a previous sonographic suspicion of agenesis of the corpus callosum (ACC) to confirm the diagnosis and to detect associated intracranial anomalies. Single-center retrospective and descriptive observational study of the brain MRI performed in 78 fetuses with ACC sonographic suspicion between January 2006 and December 2015. Two experts in fetal imaging reviewed the MRI findings to evaluate the presence and morphology of the corpus callosum. When ACC was detected the whole fetal brain anatomy was thoroughly studied to determine the presence of associated anomalies. Prenatal MR imaging findings were compared to postnatal brain MRI or necropsy findings when available. Fetal MRI diagnosed 45 cases of ACC, 12 were partial (26.7%) and 33 complete (73.3%). In 28 cases (62,2%) associated intracranial anomalies were identified. The most often abnormality was ventriculomegaly (78,6%), followed by cortical malformations (53,6%), posterior fossa (25%) and midline anomalies (10,7%). Fetal brain MRI has an important role in the diagnosis of ACC and detection of associated anomalies. To perform a fetal brain MRI is important in fetuses with sonographic suspicion of ACC. Copyright © 2017 SERAM. Publicado por Elsevier España, S.L.U. All rights reserved.

Diffusion tensor imaging of cingulum bundle and corpus callosum in schizophrenia vs. bipolar disorder.

PubMed

Nenadić, Igor; Hoof, Anna; Dietzek, Maren; Langbein, Kerstin; Reichenbach, Jürgen R; Sauer, Heinrich; Güllmar, Daniel

2017-08-30

Both schizophrenia and bipolar disorder show abnormalities of white matter, as seen in diffusion tensor imaging (DTI) analyses of major brain fibre bundles. While studies in each of the two conditions have indicated possible overlap in anatomical location, there are few direct comparisons between the disorders. Also, it is unclear whether phenotypically similar subgroups (e.g. patients with bipolar disorder and psychotic features) might share white matter pathologies or be rather similar. Using region-of-interest (ROI) analysis of white matter with diffusion tensor imaging (DTI) at 3 T, we analysed fractional anisotropy (FA), radial diffusivity (RD), and apparent diffusion coefficient (ADC) of the corpus callosum and cingulum bundle in 33 schizophrenia patients, 17 euthymic (previously psychotic) bipolar disorder patients, and 36 healthy controls. ANOVA analysis showed significant main effects of group for RD and ADC (both elevated in schizophrenia). Across the corpus callosum ROIs, there was not group effect on FA, but for RD (elevated in schizophrenia, lower in bipolar disorder) and ADC (higher in schizophrenia, intermediate in bipolar disorder). Our findings show similarities and difference (some gradual) across regions of the two major fibre tracts implicated in these disorders, which would be consistent with a neurobiological overlap of similar clinical phenotypes. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

The role of abnormalities in the corpus callosum in social cognition deficits after Traumatic Brain Injury.

PubMed

McDonald, Skye; Rushby, Jacqueline A; Dalton, Katie I; Allen, Samantha K; Parks, Nicklas

2018-08-01

The corpus callosum (CC) is vulnerable to severe traumatic brain injury (TBI). Social cognition requires integration of non-verbal and verbal information in order to understand social behaviour and may be compromised if the CC is damaged. 17 adults with severe, chronic TBI and 17 control participants underwent structural MRI and Diffusion Tensor Imaging. A region of interest analysis examined fractional anisotropy (FA) and mean diffusivity (MD) across regions of the CC. Performance on The Awareness of Social Inference Test (TASIT): part 1 (emotion recognition) and parts 2 and 3 (social inference), was examined in relation to FA and MD. Across participants, higher genu FA values were related to higher TASIT part 3 scores. Increased splenium FA was associated with better performance for TASIT parts 1-3. There was no association between DTI values and TASIT in the controls alone. In the TBI group, FA of the genu and splenium was correlated with TASIT part 3. The pattern of performance was similar when controlling for non-social cognitive ability. In conclusion, social information is complex and multi-modal requiring inter-hemispheric connection. People with TBI, regardless of focal grey matter injury, may lose social cognitive ability due to trauma related changes to the corpus callosum.

The PTI1-like kinase ZmPti1a from maize (Zea mays L.) co-localizes with callose at the plasma membrane of pollen and facilitates a competitive advantage to the male gametophyte

PubMed Central

Herrmann, Markus M; Pinto, Sheena; Kluth, Jantjeline; Wienand, Udo; Lorbiecke, René

2006-01-01

Background The tomato kinase Pto confers resistance to bacterial speck disease caused by Pseudomonas syringae pv. tomato in a gene for gene manner. Upon recognition of specific avirulence factors the Pto kinase activates multiple signal transduction pathways culminating in induction of pathogen defense. The soluble cytoplasmic serine/threonine kinase Pti1 is one target of Pto phosphorylation and is involved in the hypersensitive response (HR) reaction. However, a clear role of Pti1 in plant pathogen resistance is uncertain. So far, no Pti1 homologues from monocotyledonous species have been studied. Results Here we report the identification and molecular analysis of four Pti1-like kinases from maize (ZmPti1a, -b, -c, -d). These kinase genes showed tissue-specific expression and their corresponding proteins were targeted to different cellular compartments. Sequence similarity, expression pattern and cellular localization of ZmPti1b suggested that this gene is a putative orthologue of Pti1 from tomato. In contrast, ZmPti1a was specifically expressed in pollen and sequestered to the plasma membrane, evidently owing to N-terminal modification by myristoylation and/or S-acylation. The ZmPti1a:GFP fusion protein was not evenly distributed at the pollen plasma membrane but accumulated as an annulus-like structure which co-localized with callose (1,3-β-glucan) deposition. In addition, co-localization of ZmPti1a and callose was observed during stages of pollen mitosis I and pollen tube germination. Maize plants in which ZmPti1a expression was silenced by RNA interference (RNAi) produced pollen with decreased competitive ability. Hence, our data provide evidence that ZmPti1a plays an important part in a signalling pathway that accelerates pollen performance and male fitness. Conclusion ZmPti1a from maize is involved in pollen-specific processes during the progamic phase of reproduction, probably in crucial signalling processes associated with regions of callose deposition. Pollen-sporophyte interactions and pathogen induced HR show certain similarities. For example, HR has been shown to be associated with cell wall reinforcement through callose deposition. Hence, it is hypothesized that Pti1 kinases from maize act as general components in evolutionary conserved signalling processes associated with callose, however during different developmental programs and in different tissue types. PMID:17022830

Reducing contralateral SI activity reveals hindlimb receptive fields in the SI forelimb-stump representation of neonatally amputated rats.

PubMed

Pluto, Charles P; Chiaia, Nicolas L; Rhoades, Robert W; Lane, Richard D

2005-09-01

In adult rats that sustained forelimb amputation on the day of birth, >30% of multiunit recording sites in the forelimb-stump representation of primary somatosensory cortex (SI) also respond to cutaneous hindlimb stimulation when cortical GABA(A+B) receptors are blocked (GRB). This study examined whether hindlimb receptive fields could also be revealed in forelimb-stump sites by reducing one known source of excitatory input to SI GABAergic neurons, the contralateral SI cortex. Corpus callosum projection neurons connect homotopic SI regions, making excitatory contacts onto pyramidal cells and interneurons. Thus in addition to providing monosynaptic excitation in SI, callosal fibers can produce disynaptic inhibition through excitatory synapses with inhibitory interneurons. Based on the latter of these connections, we hypothesized that inactivating the contralateral (intact) SI forelimb region would "unmask" normally suppressed hindlimb responses by reducing the activity of SI GABAergic neurons. The SI forelimb-stump representation was first mapped under normal conditions and then during GRB to identify stump/hindlimb responsive sites. After GRB had dissipated, the contralateral (intact) SI forelimb region was mapped and reversibly inactivated with injections of 4% lidocaine, and selected forelimb-stump sites were retested. Contralateral SI inactivation revealed hindlimb responses in approximately 60% of sites that were stump/hindlimb responsive during GRB. These findings indicate that activity in the contralateral SI contributes to the suppression of reorganized hindlimb receptive fields in neonatally amputated rats.

Compensation or inhibitory failure? Testing hypotheses of age-related right frontal lobe involvement in verbal memory ability using structural and diffusion MRI

PubMed Central

Cox, Simon R.; Bastin, Mark E.; Ferguson, Karen J.; Allerhand, Mike; Royle, Natalie A.; Maniega, Susanna Muñoz; Starr, John M.; MacLullich, Alasdair M.J.; Wardlaw, Joanna M.; Deary, Ian J.; MacPherson, Sarah E.

2015-01-01

Functional neuroimaging studies report increased right prefrontal cortex (PFC) involvement during verbal memory tasks amongst low-scoring older individuals, compared to younger controls and their higher-scoring contemporaries. Some propose that this reflects inefficient use of neural resources through failure of the left PFC to inhibit non-task-related right PFC activity, via the anterior corpus callosum (CC). For others, it indicates partial compensation – that is, the right PFC cannot completely supplement the failing neural network, but contributes positively to performance. We propose that combining structural and diffusion brain MRI can be used to test predictions from these theories which have arisen from fMRI studies. We test these hypotheses in immediate and delayed verbal memory ability amongst 90 healthy older adults of mean age 73 years. Right hippocampus and left dorsolateral prefrontal cortex (DLPFC) volumes, and fractional anisotropy (FA) in the splenium made unique contributions to verbal memory ability in the whole group. There was no significant effect of anterior callosal white matter integrity on performance. Rather, segmented linear regression indicated that right DLPFC volume was a significantly stronger positive predictor of verbal memory for lower-scorers than higher-scorers, supporting a compensatory explanation for the differential involvement of the right frontal lobe in verbal memory tasks in older age. PMID:25241394

Association of brain metabolism with sulcation and corpus callosum development assessed by MRI in late-onset small fetuses.

PubMed

Sanz-Cortes, Magdalena; Egaña-Ugrinovic, Gabriela; Simoes, Rui V; Vazquez, Lucia; Bargallo, Nuria; Gratacos, Eduard

2015-06-01

We sought to determine the relationship between fetal brain metabolism and microstructure expressed by brain sulcation, and corpus callosum (CC) development assessed by fetal brain magnetic resonance (MR) imaging and proton MR spectroscopy ((1)H-MRS). A total of 119 fetuses, 64 that were small for gestational age (estimated fetal weight <10th centile and normal umbilical artery Doppler) and 55 controls underwent a 3T MR imaging/(1)H-MRS exam at 37 weeks. Anatomical T2-weighted images were obtained in the 3 orthogonal planes and long echo time (TE) (1)H-MRS acquired from the frontal lobe. Head biometrics, cortical fissure depths (insula, Sylvian, parietooccipital, cingulate, and calcarine), and CC area and biometries were blindly performed by manual and semiautomated delineation using Analyze software and corrected creating ratios for biparietal diameter and frontooccipital diameter, respectively, for group comparison. Spectroscopic data were processed using LCModel software and analyzed as metabolic ratios of N-acetylaspartate (NAA) to choline (Cho), Cho to creatine (Cr), and myo-inositol (Ino) to Cho. Differences between cases and controls were assessed. To test for the association between metabolic ratios and microstructural parameters, bivariate correlation analyses were performed. Spectroscopic findings showed decreased NAA/Cho and increased Cho/Cr ratios in small fetuses. They also presented smaller head biometrics, shorter and smaller CC, and greater insular and cingulate depths. Frontal lobe NAA/Cho significantly correlated with biparietal diameter (r = 0.268; P = .021), head circumference (r = 0.259; P = .026), CC length (r = 0.265; P = .026), CC area (r = 0.317; P = .007), and the area of 6 from the 7 CC subdivisions. It did not correlate with any of the cortical sulcation parameters evaluated. None of the other metabolic ratios presented significant correlations with cortical development or CC parameters. Frontal lobe NAA/Cho levels-which are considered a surrogate marker of neuronal activity-show a strong association with CC development. These results suggest that both metabolic and callosal alterations may be part of the same process of impaired brain development associated with intrauterine growth restriction. Copyright © 2015 Elsevier Inc. All rights reserved.

Effects of tissue-preparation-induced callose synthesis on estimates of plasmodesma size exclusion limits.

PubMed

Radford, J E; White, R G

2001-01-01

Plasmodesmata are often characterised by their size exclusion limit (SEL), which is the molecular weight of the largest dye, introduced by microinjection, that will move from cell to cell. In this study, we investigated whether commonly used techniques for isolation and manipulation of tissues, and microinjection of fluorescent dyes, affected the SEL, and whether any such effects could be ameliorated by inhibiting callose deposition. We examined young root epidermal cells of Arabidopsis thaliana and staminal hair cells of Tradescantia virginiana, two tissues often used in experiments on symplastic transport. Transport in root tips dissected from the main plant body and in stamen hairs removed from the base of the stamen filament was compared with transport in undissected roots and stamen hairs attached to the base of the filament, respectively. Tissues were microinjected with fluorescent dyes (457 Da to > 3 kDa) with or without prior incubation in the callose deposition inhibitors 2-deoxy-D-glucose or aniline blue fluorochrome. In both tissues, dissection reduced the SEL, which was largely prevented by prior incubation in 2-deoxy-D-glucose but not by incubation in aniline blue fluorochrome. Thus, standard methods for tissue preparation can cause sufficient callose deposition to reduce cell-to-cell transport, and this needs to be considered in studies employing microinjection. Introduction of the dyes by pressure injection rather than iontophoresis decreased the SEL in A. thaliana but increased it in T. virginiana, showing that these two injection techniques do not necessarily give identical results and that plasmodesmata in different tissues may respond differently to similar experimental procedures.

Surface-based brain morphometry and diffusion tensor imaging in schizoaffective disorder.

PubMed

Landin-Romero, Ramón; Canales-Rodríguez, Erick J; Kumfor, Fiona; Moreno-Alcázar, Ana; Madre, Mercè; Maristany, Teresa; Pomarol-Clotet, Edith; Amann, Benedikt L

2017-01-01

The profile of grey matter abnormalities and related white-matter pathology in schizoaffective disorder has only been studied to a limited extent. The aim of this study was to identify grey- and white-matter abnormalities in patients with schizoaffective disorder using complementary structural imaging techniques. Forty-five patients meeting Diagnostic and Statistical Manual of Mental Disorders-Fourth Edition criteria and Research Diagnostic Criteria for schizoaffective disorder and 45 matched healthy controls underwent structural-T1 and diffusion magnetic resonance imaging to enable surface-based brain morphometry and diffusion tensor imaging analyses. Analyses were conducted to determine group differences in cortical volume, cortical thickness and surface area, as well as in fractional anisotropy and mean diffusivity. At a threshold of p = 0.05 corrected, all measures revealed significant differences between patients and controls at the group level. Spatial overlap of abnormalities was observed across the various structural neuroimaging measures. In grey matter, patients with schizoaffective disorder showed abnormalities in the frontal and temporal lobes, striatum, fusiform, cuneus, precuneus, lingual and limbic regions. White-matter abnormalities were identified in tracts connecting these areas, including the corpus callosum, superior and inferior longitudinal fasciculi, anterior thalamic radiation, uncinate fasciculus and cingulum bundle. The spatial overlap of abnormalities across the different imaging techniques suggests widespread and consistent brain pathology in schizoaffective disorder. The abnormalities were mainly detected in areas that have commonly been reported to be abnormal in schizophrenia, and to some extent in bipolar disorder, which may explain the clinical and aetiological overlap in these disorders.

Local cerebral glucose metabolism in patients with long-term behavioral and cognitive deficits following mild traumatic brain injury.

PubMed

Gross, H; Kling, A; Henry, G; Herndon, C; Lavretsky, H

1996-01-01

A retrospective study of 20 patients with mild traumatic brain injury (MTBI) examined brain regions of interest by comparing [18F]-2-deoxyglucose PET, neuropsychological test results, and continuing behavioral dysfunction. Abnormal local cerebral metabolic rates (rLCMs) were most prominent in midtemporal, anterior cingulate, precuneus, anterior temporal, frontal white, and corpus callosum brain regions. Abnormal rLCMs were significantly correlated statistically with 1) overall clinical complaints, most specifically with inconsistent attention/concentration and 2) overall neuropsychological test results. The authors conclude that 1) even mild TBI may result in continuing brain behavioral deficits; 2) PET can help elucidate dysfunctional brain circuitry in neurobehavioral disorders; and 3) specific brain areas may correlate with deficits in daily neurobehavioral functioning and neuropsychological test findings.

Interhemispheric Effective and Functional Cortical Connectivity Signatures of Spina Bifida Are Consistent with Callosal Anomaly

PubMed Central

Malekpour, Sheida; Li, Zhimin; Cheung, Bing Leung Patrick; Castillo, Eduardo M.; Papanicolaou, Andrew C.; Kramer, Larry A.; Fletcher, Jack M.

2012-01-01

Abstract The impact of the posterior callosal anomalies associated with spina bifida on interhemispheric cortical connectivity is studied using a method for estimating cortical multivariable autoregressive models from scalp magnetoencephalography data. Interhemispheric effective and functional connectivity, measured using conditional Granger causality and coherence, respectively, is determined for the anterior and posterior cortical regions in a population of five spina bifida and five control subjects during a resting eyes-closed state. The estimated connectivity is shown to be consistent over the randomly selected subsets of the data for each subject. The posterior interhemispheric effective and functional connectivity and cortical power are significantly lower in the spina bifida group, a result that is consistent with posterior callosal anomalies. The anterior interhemispheric effective and functional connectivity are elevated in the spina bifida group, a result that may reflect compensatory mechanisms. In contrast, the intrahemispheric effective connectivity is comparable in the two groups. The differences between the spina bifida and control groups are most significant in the θ and α bands. PMID:22571349

Sieve tube geometry in relation to phloem flow.

PubMed

Mullendore, Daniel L; Windt, Carel W; Van As, Henk; Knoblauch, Michael

2010-03-01

Sieve elements are one of the least understood cell types in plants. Translocation velocities and volume flow to supply sinks with photoassimilates greatly depend on the geometry of the microfluidic sieve tube system and especially on the anatomy of sieve plates and sieve plate pores. Several models for phloem translocation have been developed, but appropriate data on the geometry of pores, plates, sieve elements, and flow parameters are lacking. We developed a method to clear cells from cytoplasmic constituents to image cell walls by scanning electron microscopy. This method allows high-resolution measurements of sieve element and sieve plate geometries. Sieve tube-specific conductivity and its reduction by callose deposition after injury was calculated for green bean (Phaseolus vulgaris), bamboo (Phyllostachys nuda), squash (Cucurbita maxima), castor bean (Ricinus communis), and tomato (Solanum lycopersicum). Phloem sap velocity measurements by magnetic resonance imaging velocimetry indicate that higher conductivity is not accompanied by a higher velocity. Studies on the temporal development of callose show that small sieve plate pores might be occluded by callose within minutes, but plants containing sieve tubes with large pores need additional mechanisms.

The life of phi: the development of phi thickenings in roots of the orchids of the genus Miltoniopsis.

PubMed

Idris, Nurul A; Collings, David A

2015-02-01

Phi thickenings, bands of secondary wall thickenings that reinforce the primary wall of root cortical cells in a wide range of species, are described for the first time in the epiphytic orchid Miltoniopsis. As with phi thickenings found in other plants, the phi thickenings in Miltoniopsis contain highly aligned cellulose running along the lengths of the thickenings, and are lignified but not suberized. Using a combination of histological and immunocytochemical techniques, thickening development can be categorized into three different stages. Microtubules align lengthwise along the thickening during early and intermediate stages of development, and callose is deposited within the thickening in a pattern similar to the microtubules. These developing thickenings also label with the fluorescently tagged lectin wheat germ agglutinin (WGA). These associations with microtubules and callose, and the WGA labeling, all disappear when the phi thickenings are mature. This pattern of callose and WGA deposition show changes in the thickened cell wall composition and may shed light on the function of phi thickenings in plant roots, a role for which has yet to be established.

Plasmodesmata-mediated intercellular signaling during plant growth and development.

PubMed

Yadav, Shri R; Yan, Dawei; Sevilem, Iris; Helariutta, Ykä

2014-01-01

Plasmodesmata (PD) are cytoplasmic channels that connect neighboring cells for cell-to-cell communication. PD structure and function vary temporally and spatially to allow formation of symplastic domains during different stages of plant development. Reversible deposition of callose at PD plays an important role in controlling molecular trafficking through PD by regulating their size exclusion limit. Previously, we reported several semi-dominant mutants for CALLOSE SYNTHASE 3 (CALS3) gene, which overproduce callose at PD in Arabidopsis. By combining two of these mutations in a LexA-VP16-ER (XVE)-based estradiol inducible vector system, a tool known as the "icals3m system" was developed to temporally obstruct the symplastic connections in a specified spatial domain. The system has been successfully tested and used, in combination with other methods, to investigate the route for mobile signals such as the SHR protein, microRNA165/6, and cytokinins in Arabidopsis roots, and also to understand the role of symplastic domain formation during lateral root development. We envision that this tool may also be useful for identifying tissue-specific symplastic regulatory networks and to analyze symplastic movement of metabolites.

Identification of Eye-Specific Domains and Their Relation to Callosal Connections in Primary Visual Cortex of Long Evans Rats.

PubMed

Laing, R J; Turecek, J; Takahata, T; Olavarria, J F

2015-10-01

Ocular dominance columns (ODCs) exist in many primates and carnivores, but it is believed that they do not exist in rodents. Using a combination of transneuronal tracing, in situ hybridization for Zif268 and electrophysiological recordings, we show that inputs from both eyes are largely segregated in the binocular region of V1 in Long Evans rats. We also show that, interposed between this binocular region and the lateral border of V1, there lies a strip of cortex that is strongly dominated by the contralateral eye. Finally, we show that callosal connections colocalize primarily with ipsilateral eye domains in the binocular region and with contralateral eye input in the lateral cortical strip, mirroring the relationship between patchy callosal connections and specific sets of ODCs described previously in the cat. Our results suggest that development of cortical modular architecture is more conserved among rodents, carnivores, and primates than previously thought. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Sieve Tube Geometry in Relation to Phloem Flow

PubMed Central

Mullendore, Daniel L.; Windt, Carel W.; Van As, Henk; Knoblauch, Michael

2010-01-01

Sieve elements are one of the least understood cell types in plants. Translocation velocities and volume flow to supply sinks with photoassimilates greatly depend on the geometry of the microfluidic sieve tube system and especially on the anatomy of sieve plates and sieve plate pores. Several models for phloem translocation have been developed, but appropriate data on the geometry of pores, plates, sieve elements, and flow parameters are lacking. We developed a method to clear cells from cytoplasmic constituents to image cell walls by scanning electron microscopy. This method allows high-resolution measurements of sieve element and sieve plate geometries. Sieve tube–specific conductivity and its reduction by callose deposition after injury was calculated for green bean (Phaseolus vulgaris), bamboo (Phyllostachys nuda), squash (Cucurbita maxima), castor bean (Ricinus communis), and tomato (Solanum lycopersicum). Phloem sap velocity measurements by magnetic resonance imaging velocimetry indicate that higher conductivity is not accompanied by a higher velocity. Studies on the temporal development of callose show that small sieve plate pores might be occluded by callose within minutes, but plants containing sieve tubes with large pores need additional mechanisms. PMID:20354199

Seizures and electroencephalography findings in 61 patients with fetal alcohol spectrum disorders.

PubMed

Boronat, S; Vicente, M; Lainez, E; Sánchez-Montañez, A; Vázquez, E; Mangado, L; Martínez-Ribot, L; Del Campo, M

2017-01-01

Fetal alcohol spectrum disorders (FASD) cause neurodevelopmental abnormalities. However, publications about epilepsy and electroencephalographic features are scarce. In this study, we prospectively performed electroencephalography (EEG) and brain magnetic resonance (MR) imaging in 61 patients with diagnosis of FASD. One patient had multiple febrile seizures with normal EEGs. Fourteen children showed EEG anomalies, including slow background activity and interictal epileptiform discharges, focal and/or generalized, and 3 of them had epilepsy. In one patient, seizures were first detected during the EEG recording and one case had an encephalopathy with electrical status epilepticus during slow sleep (ESES). Focal interictal discharges in our patients did not imply the presence of underlying visible focal brain lesions in the neuroimaging studies, such as cortical dysplasia or polymicrogyria. However, they had nonspecific brain MR abnormalities, including corpus callosum hypoplasia, vermis hypoplasia or cavum septum pellucidum. The latter was significantly more frequent in the group with EEG abnormal findings (p < 0.01). Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Effect of HIF-1a/VEGF signaling pathway on plasma progesterone and ovarian prostaglandin F₂a secretion during luteal development of pseudopregnant rats.

PubMed

Pan, X Y; Zhang, Z H; Wu, L X; Wang, Z C

2015-08-03

The corpus luteum is a temporary endocrine structure in mammals that plays an important role in the female reproductive cycle and is formed from a ruptured and ovulated follicle with rapid angiogenesis. Vascular endothelial growth factor (VEGF) is thought to be vital in normal and abnormal angiogenesis in the ovary, but the molecular regulation of luteal VEGF expression during corpus luteum development in vivo is still poorly understood at present. Therefore, we examined whether hypoxia-inducible factor-1a (HIF-1a) is induced and regulates VEGF expression and luteal function in vivo using a pseudopregnant rat model treated with a small-molecule inhibitor of HIF-1a, echinomycin. Corpus luteum development in the pseudopregnant rat ovary was determined after measuring plasma progesterone concentration and ovarian prostaglandin F2a content to reflect changes in HIF-1a and VEGF on different days of this developmental process. At day 7, the corpus luteum was formed and the expression of HIF- 1a/VEGF reached a maximum, while a significant decrease in HIF-1a/ VEGF expression was observed when luteolysis occurred at day 13. Additionally, echinomycin blocked luteal development by inhibiting VEGF expression mediated by HIF-1a and following luteal function by detecting the progesterone changes at day 7. These results demonstrated that HIF-1a-mediated VEGF expression might be an important mechanism regulating ovarian luteal development in mammals in vivo, which may provide new strategies for fertility control and for treating some types of ovarian dysfunction, such as polycystic ovarian syndrome, ovarian hyperstimulation syndrome, and ovarian neoplasia.

Effect of hypothyroidism on the nitrergic relaxant responses of corpus cavernosal smooth muscle in rabbits.

PubMed

Sarac, Bulent; Yildirim, Mustafa K; Bagcivan, Ihsan; Kaya, Kemal; Kilicarslan, Hakan; Yildirim, Sahin

2006-01-01

The incidence of hormonal dysfunction as a cause of impotence remains controversial. However, several recent studies have reported evidence of hormonal abnormalities in 25-35% of impotent men. Hypothyroidism has been reported to occur in 6% of impotent men. In the present study, we examined nitrergic responses in hypothyroidism in rabbit corpus cavernosum and compared them with controls. Carbachol-induced relaxation responses and electrical field stimulation (EFS)-induced frequency-dependent relaxations decreased significantly in hypothyroid rabbits. Papaverine and sodium nitroprusside (SNP)-induced relaxation responses did not change significantly in hypothyroid rabbits. The contraction responses of phenylephrine and EFS-induced frequency-dependent contractions were significantly decreased in the hypothyroid group. We can speculate that the reduction of relaxant responses to EFS and carbachol in hypothyroid rabbits can depend on a decreased release of nitric oxide (NO) from nitrergic nerves and endothelium or a reduction of muscarinic receptor density. Also, decreases in contraction responses may depend on diminished adrenoceptor density.

[Metronidazole-Induced Encephalopathy during Brain Abscess Treatment:Two Case Reports].

PubMed

Yokoyama, Yuka; Asaoka, Katsuyuki; Sugiyama, Taku; Uchida, Kazuki; Shimbo, Daisuke; Kobayashi, Satoshi; Itamoto, Koji

2015-10-01

Metronidazole is a widely used antibiotic against anaerobic bacteria and protozoa. We report two cases of metronidazole-induced encephalopathy(MIE)during treatment of a brain abscess with metronidazole. The patients developed mental disturbance, and brain MRI showed reversible signals on DWI, FLAIR, and T2. Case 1: A 48-year-old woman was admitted to our hospital with a cerebellar abscess. We initiated treatment with oral metronidazole. After taking the medication, she developed mental disturbance, and her brain MRI showed a hyperintensity within the corpus callosum. We suspected metronidazole toxicity and discontinued metronidazole treatment. The symptoms resolved rapidly within a week, and the hyperintensity on the MRI disappeared. Case 2: A 22-year-old man was admitted to our hospital with a brain abscess. We initiated treatment with oral metronidazole. On day 38, he developed mental disturbance, and his MRI showed hyperintensities within the bilateral dentate nuclei and corpus callosum. These symptoms were consistent with MIE. After cessation of metronidazole, his symptoms and abnormal MRI signals completely disappeared.

Reduced Integrity of Right Lateralized White Matter in Patients with Primary Insomnia: A Diffusion-Tensor Imaging Study.

PubMed

Li, Shumei; Tian, Junzhang; Bauer, Andreas; Huang, Ruiwang; Wen, Hua; Li, Meng; Wang, Tianyue; Xia, Likun; Jiang, Guihua

2016-08-01

Purpose To analyze the integrity of white matter (WM) tracts in primary insomnia patients and provide better characterization of abnormal WM integrity and its relationship with disease duration and clinical features of primary insomnia. Materials and Methods This prospective study was approved by the ethics committee of the Guangdong No. 2 Provincial People's Hospital. Tract-based spatial statistics were used to compare changes in diffusion parameters of WM tracts from 23 primary insomnia patients and 30 healthy control (HC) participants, and the accuracy of these changes in distinguishing insomnia patients from HC participants was evaluated. Voxel-wise statistics across subjects was performed by using a 5000-permutation set with family-wise error correction (family-wise error, P < .05). Multiple regressions were used to analyze the associations between the abnormal fractional anisotropy (FA) in WM with disease duration, Pittsburgh Sleep Quality Index, insomnia severity index, self-rating anxiety scale, and the self-rating depression scale in primary insomnia. Characteristics for abnormal WM were also investigated in tract-level analyses. Results Primary insomnia patients had lower FA values mainly in the right anterior limb of the internal capsule, right posterior limb of the internal capsule, right anterior corona radiata, right superior corona radiata, right superior longitudinal fasciculus, body of the corpus callosum, and right thalamus (P < .05, family-wise error correction). The receiver operating characteristic areas for the seven regions were acceptable (range, 0.60-0.74; 60%-74%). Multiple regression models showed abnormal FA values in the thalamus and body corpus callosum were associated with the disease duration, self-rating depression scale, and Pittsburgh Sleep Quality Index scores. Tract-level analysis suggested that the reduced FA values might be related to greater radial diffusivity. Conclusion This study showed that WM tracts related to regulation of sleep and wakefulness, and limbic cognitive and sensorimotor regions, are disrupted in the right brain in patients with primary insomnia. The reduced integrity of these WM tracts may be because of loss of myelination. (©) RSNA, 2016.

Age-dependent long-term structural and functional effects of early life seizures: evidence for a hippocampal critical period influencing plasticity in adulthood

PubMed Central

Meyerand, M.E.; Sutula, T.

2015-01-01

Neural activity promotes circuit formation in developing systems and during critical periods permanently modifies circuit organization and functional properties. These observations suggest that excessive neural activity, as occurs during seizures, might influence developing neural circuitry with long-term outcomes that depend on age at the time of seizures. We systematically examined long-term structural and functional consequences of seizures induced in rats by kainic acid, pentylenetetrazol, and hyperthermia across postnatal ages from birth through postnatal day 90 in adulthood (P90). Magnetic resonance imaging (MRI), diffusion tensor imaging (DTI), and electrophysiological methods at ≥P95 following seizures induced from P1 to P90 demonstrated consistent patterns of gross atrophy, microstructural abnormalities in the corpus callosum and hippocampus, and functional alterations in hippocampal circuitry at ≥P95 that were independent of the method of seizure induction and varied systematically as a function of age at the time of seizures. Three distinct epochs were observed in which seizures resulted in distinct long-term structural and functional outcomes at ≥P95. Seizures prior to P20 resulted in DTI abnormalities in corpus callosum and hippocampus in the absence of gross cerebral atrophy, and increased paired pulse inhibition (PPI) in the dentate gyrus at ≥P95. Seizures after P30 induced a different pattern of DTI abnormalities in the fimbria and hippocampus accompanied by gross cerebral atrophy with increases in lateral ventricular volume, as well as increased PPI in the dentate gyrus at ≥P95. In contrast, seizures between P20-P30 did not result in cerebral atrophy or significant imaging abnormalities in the hippocampus or white matter, but irreversibly decreased PPI in the dentate gyrus compared to normal adult controls. These age-specific long-term structural and functional outcomes identify P20-P30 as a potential critical period in hippocampal development defined by distinctive long-term structural and functional properties in adult hippocampal circuitry, including loss of capacity for seizure-induced plasticity in adulthood that could influence epileptogenesis and other hippocampal – dependent behaviors and functional properties. PMID:25555928

MRI or not to MRI! Should brain MRI be a routine investigation in children with autistic spectrum disorders?

PubMed

Zeglam, Adel M; Al-Ogab, Marwa F; Al-Shaftery, Thouraya

2015-09-01

To evaluate the routine usage of Magnetic Resonance Imaging (MRI) of brain and estimate the prevalence of brain abnormalities in children presenting to the Neurodevelopment Clinic of Al-Khadra Hospital (NDC-KH), Tripoli, Libya with autistic spectrum disorders (ASD). The records of all children with ASD presented to NDC-KH over 4-year period (from January 2009 to December 2012) were reviewed. All MRIs were acquired with a 1.5-T Philips (3-D T1, T2, FLAIR coronal and axial sequences). MRIs were reported to be normal, abnormal or no significant abnormalities by a consultant neuroradiologist. One thousand and seventy-five children were included in the study. Seven hundred and eighty-two children (72.7 %) had an MRI brain of whom 555 (71 %) were boys. 26 children (24 males and 2 females) (3.3 %) demonstrated MRI abnormalities (8 leukodystrophic changes, 4 periventricular leukomalacia, 3 brain atrophy, 2 tuberous sclerosis, 2 vascular changes, 1 pineoblastoma, 1 cerebellar angioma, 1 cerebellar hypoplasia, 3 agenesis of corpus callosum, 1 neuro-epithelial cyst). An unexpectedly high rate of MRI abnormalities was found in the first large series of clinical MRI investigations in children with autism. These results could contribute to further research into the pathogenesis of autistic spectrum disorder.

Tocopherol deficiency reduces sucrose export from salt-stressed potato leaves independently of oxidative stress and symplastic obstruction by callose

PubMed Central

Asensi-Fabado, María Amparo; Ammon, Alexandra; Sonnewald, Uwe; Munné-Bosch, Sergi; Voll, Lars M.

2015-01-01

Tocopherol cyclase, encoded by the gene SUCROSE EXPORT DEFECTIVE1, catalyses the second step in the synthesis of the antioxidant tocopherol. Depletion of SXD1 activity in maize and potato leaves leads to tocopherol deficiency and a ‘sugar export block’ phenotype that comprises massive starch accumulation and obstruction of plasmodesmata in paraveinal tissue by callose. We grew two transgenic StSXD1:RNAi potato lines with severe tocopherol deficiency under moderate light conditions and subjected them to salt stress. After three weeks of salt exposure, we observed a strongly reduced sugar exudation rate and a lack of starch mobilization in leaves of salt-stressed transgenic plants, but not in wild-type plants. However, callose accumulation in the vasculature declined upon salt stress in all genotypes, indicating that callose plugging of plasmodesmata was not the sole cause of the sugar export block phenotype in tocopherol-deficient leaves. Based on comprehensive gene expression analyses, we propose that enhanced responsiveness of SnRK1 target genes in mesophyll cells and altered redox regulation of phloem loading by SUT1 contribute to the attenuation of sucrose export from salt-stressed SXD:RNAi source leaves. Furthermore, we could not find any indication that elevated oxidative stress may have served as a trigger for the salt-induced carbohydrate phenotype of SXD1:RNAi transgenic plants. In leaves of the SXD1:RNAi plants, sodium accumulation was diminished, while proline accumulation and pools of soluble antioxidants were increased. As supported by phytohormone contents, these differences seem to increase longevity and prevent senescence of SXD:RNAi leaves under salt stress. PMID:25428995

Encephalopathy and Neuropathy due to Glue, Paint Thinner, and Gasoline Sniffing in Trinidad and Tobago-MRI Findings.

PubMed

Ramcharan, Kanterpersad; Ramesar, Amrit; Ramdath, Moshanti; Teelucksingh, Joel; Gosein, Maria

2014-01-01

A 29-year-old male petrol station pump attendant was admitted with ataxia and clinical evidence of a sensorimotor polyneuropathy which developed over the preceding 3 months. He had cognitive dysfunction, hearing loss, and cerebellar clinical abnormalities that came on slowly over the three years. He had a fifteen-year history of sniffing mostly glue, occasionally paint thinners, and, in the recent two years, gasoline. Magnetic resonance brain imaging showed abnormalities of the cerebral cortex, cerebral white matter, corpus callosum, hippocampus, brainstem and cerebellar atrophy, hypointensities of basal ganglia, red nuclei, and substantia nigra as previously described in toluene sniffing. Abstinence for six months led to partial clinical improvement. Clinicians need to be aware of this preventable entity which has peculiar radiological findings which are being increasingly accepted as typical.

Encephalopathy and Neuropathy due to Glue, Paint Thinner, and Gasoline Sniffing in Trinidad and Tobago-MRI Findings

PubMed Central

Ramcharan, Kanterpersad; Ramesar, Amrit; Ramdath, Moshanti; Teelucksingh, Joel; Gosein, Maria

2014-01-01

A 29-year-old male petrol station pump attendant was admitted with ataxia and clinical evidence of a sensorimotor polyneuropathy which developed over the preceding 3 months. He had cognitive dysfunction, hearing loss, and cerebellar clinical abnormalities that came on slowly over the three years. He had a fifteen-year history of sniffing mostly glue, occasionally paint thinners, and, in the recent two years, gasoline. Magnetic resonance brain imaging showed abnormalities of the cerebral cortex, cerebral white matter, corpus callosum, hippocampus, brainstem and cerebellar atrophy, hypointensities of basal ganglia, red nuclei, and substantia nigra as previously described in toluene sniffing. Abstinence for six months led to partial clinical improvement. Clinicians need to be aware of this preventable entity which has peculiar radiological findings which are being increasingly accepted as typical. PMID:25045557

The Effects of Age, Memory Performance, and Callosal Integrity on the Neural Correlates of Successful Associative Encoding

PubMed Central

Wang, Tracy H.; Minton, Brian; Muftuler, L. Tugan; Rugg, Michael D.

2011-01-01

This functional magnetic resonance imaging study investigated the relationship between the neural correlates of associative memory encoding, callosal integrity, and memory performance in older adults. Thirty-six older and 18 young subjects were scanned while making relational judgments on word pairs. Neural correlates of successful encoding (subsequent memory effects) were identified by contrasting the activity elicited by study pairs that were correctly identified as having been studied together with the activity elicited by pairs wrongly judged to have come from different study trials. Subsequent memory effects common to the 2 age groups were identified in several regions, including left inferior frontal gyrus and bilateral hippocampus. Negative effects (greater activity for forgotten than for remembered items) in default network regions in young subjects were reversed in the older group, and the amount of reversal correlated negatively with memory performance. Additionally, older subjects' subsequent memory effects in right frontal cortex correlated positively with anterior callosal integrity and negatively with memory performance. It is suggested that recruitment of right frontal cortex during verbal memory encoding may reflect the engagement of processes that compensate only partially for age-related neural degradation. PMID:21282317

Validation of In utero Tractography of Human Fetal Commissural and Internal Capsule Fibers with Histological Structure Tensor Analysis

PubMed Central

Mitter, Christian; Jakab, András; Brugger, Peter C.; Ricken, Gerda; Gruber, Gerlinde M.; Bettelheim, Dieter; Scharrer, Anke; Langs, Georg; Hainfellner, Johannes A.; Prayer, Daniela; Kasprian, Gregor

2015-01-01

Diffusion tensor imaging (DTI) and tractography offer the unique possibility to visualize the developing white matter macroanatomy of the human fetal brain in vivo and in utero and are currently under investigation for their potential use in the diagnosis of developmental pathologies of the human central nervous system. However, in order to establish in utero DTI as a clinical imaging tool, an independent comparison between macroscopic imaging and microscopic histology data in the same subject is needed. The present study aimed to cross-validate normal as well as abnormal in utero tractography results of commissural and internal capsule fibers in human fetal brains using postmortem histological structure tensor (ST) analysis. In utero tractography findings from two structurally unremarkable and five abnormal fetal brains were compared to the results of postmortem ST analysis applied to digitalized whole hemisphere sections of the same subjects. An approach to perform ST-based deterministic tractography in histological sections was implemented to overcome limitations in correlating in utero tractography to postmortem histology data. ST analysis and histology-based tractography of fetal brain sections enabled the direct assessment of the anisotropic organization and main fiber orientation of fetal telencephalic layers on a micro- and macroscopic scale, and validated in utero tractography results of corpus callosum and internal capsule fiber tracts. Cross-validation of abnormal in utero tractography results could be achieved in four subjects with agenesis of the corpus callosum (ACC) and in two cases with malformations of internal capsule fibers. In addition, potential limitations of current DTI-based in utero tractography could be demonstrated in several brain regions. Combining the three-dimensional nature of DTI-based in utero tractography with the microscopic resolution provided by histological ST analysis may ultimately facilitate a more complete morphologic characterization of axon guidance disorders at prenatal stages of human brain development. PMID:26732460

Neuroanatomical Heterogeneity of Essential Tremor According to Propranolol Response

PubMed Central

Chung, Seok Jong; Kwon, Hunki; Lee, Dong-Kyun; Hong, Jin Yong; Sunwoo, Mun-Kyung; Sohn, Young H.; Lee, Jong-Min; Lee, Phil Hyu

2013-01-01

Background Recent studies have suggested that essential tremor (ET) is a more complex and heterogeneous clinical entity than initially thought. In the present study, we assessed the pattern of cortical thickness and diffusion tensor white matter (WM) changes in patients with ET according to the response to propranolol to explore the pathogenesis underlying the clinical heterogeneity of ET. Methods A total of 32 patients with drug naive ET were recruited prospectively from the Movement Disorders outpatient clinic. The patients were divided into a propranolol-responder group (n = 18) and a non-responder group (n = 14). We analyzed the pattern of cortical thickness and diffusion tensor WM changes between these two groups and performed correlation analysis between imaging and clinical parameters. Results There were no significant differences in demographic characteristics, general cognition, or results of detailed neuropsychological tests between the groups. The non-responder group showed more severe cortical atrophy in the left orbitofrontal cortex and right temporal cortex relative to responders. However, the responders exhibited significantly lower fractional anisotropy values in the bilateral frontal, corpus callosal, and right parietotemporal WM compared with the non-responder group. There were no significant clusters where the cortical thickness or WM alterations were significantly correlated with initial tremor severity or disease duration. Conclusions The present data suggest that patients with ET have heterogeneous cortical thinning and WM alteration with respect to responsiveness to propranolol, suggesting that propranolol responsiveness may be a predictive factor to determine ET subtypes in terms of neuroanatomical heterogeneity. PMID:24358327

Transcallosal Projections Require Glycoprotein M6-Dependent Neurite Growth and Guidance.

PubMed

Mita, Sakura; de Monasterio-Schrader, Patricia; Fünfschilling, Ursula; Kawasaki, Takahiko; Mizuno, Hidenobu; Iwasato, Takuji; Nave, Klaus-Armin; Werner, Hauke B; Hirata, Tatsumi

2015-11-01

The function of mature neurons critically relies on the developmental outgrowth and projection of their cellular processes. It has long been postulated that the neuronal glycoproteins M6a and M6b are involved in axon growth because these four-transmembrane domain-proteins of the proteolipid protein family are highly enriched on growth cones, but in vivo evidence has been lacking. Here, we report that the function of M6 proteins is required for normal axonal extension and guidance in vivo. In mice lacking both M6a and M6b, a severe hypoplasia of axon tracts was manifested. Most strikingly, the corpus callosum was reduced in thickness despite normal densities of cortical projection neurons. In single neuron tracing, many axons appeared shorter and disorganized in the double-mutant cortex, and some of them were even misdirected laterally toward the subcortex. Probst bundles were not observed. Upon culturing, double-mutant cortical and cerebellar neurons displayed impaired neurite outgrowth, indicating a cell-intrinsic function of M6 proteins. A rescue experiment showed that the intracellular loop of M6a is essential for the support of neurite extension. We propose that M6 proteins are required for proper extension and guidance of callosal axons that follow one of the most complex trajectories in the mammalian nervous system. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Apparent Fibre Density: a novel measure for the analysis of diffusion-weighted magnetic resonance images.

PubMed

Raffelt, David; Tournier, J-Donald; Rose, Stephen; Ridgway, Gerard R; Henderson, Robert; Crozier, Stuart; Salvado, Olivier; Connelly, Alan

2012-02-15

This article proposes a new measure called Apparent Fibre Density (AFD) for the analysis of high angular resolution diffusion-weighted images using higher-order information provided by fibre orientation distributions (FODs) computed using spherical deconvolution. AFD has the potential to provide specific information regarding differences between populations by identifying not only the location, but also the orientations along which differences exist. In this work, analytical and numerical Monte-Carlo simulations are used to support the use of the FOD amplitude as a quantitative measure (i.e. AFD) for population and longitudinal analysis. To perform robust voxel-based analysis of AFD, we present and evaluate a novel method to modulate the FOD to account for changes in fibre bundle cross-sectional area that occur during spatial normalisation. We then describe a novel approach for statistical analysis of AFD that uses cluster-based inference of differences extended throughout space and orientation. Finally, we demonstrate the capability of the proposed method by performing voxel-based AFD comparisons between a group of Motor Neurone Disease patients and healthy control subjects. A significant decrease in AFD was detected along voxels and orientations corresponding to both the corticospinal tract and corpus callosal fibres that connect the primary motor cortices. In addition to corroborating previous findings in MND, this study demonstrates the clear advantage of using this type of analysis by identifying differences along single fibre bundles in regions containing multiple fibre populations. Copyright © 2011 Elsevier Inc. All rights reserved.

Fatal pediatric head injury due to toppled television: does the injury pattern overlap with abusive head trauma?

PubMed

Kodikara, Sarathchandra; Pollanen, Michael

2012-07-01

Pediatric head injuries can occur from abusive head trauma (AHT) or accidents. Accidental pediatric head injuries caused by cathode-ray tube televisions (CRTT) toppling have become a 'silent epidemic'. Differentiation between a fatal case of AHT and CRTT toppling could be vexing when the historical and scene evidence are subtle. A 2-year-old girl was found unresponsive in her house and could not be resuscitated. A 27" CRTT was found fallen from its stand onto the floor at the scene. The siblings report that the deceased was climbing on the television stand when it toppled. Autopsy revealed a spectrum of head injuries including, contusions, fractures, bilateral acute subdural hemorrhages, subarachnoid hemorrhages, brain contusion-lacerations and corpus callosal hemorrhages. Microscopy of the eyes revealed bilateral acute retinal hemorrhages. The cause of death was given as crushing injuries of head and brain. The skull fracture pattern is compatible with an accident causing crush injury due to the toppled CRTT rather than AHT. The injury pattern reconfirms that the head is the most vulnerable site in case of CRTT tipover. Although there may be an overlap between the injury pattern in AHT and in CRTT tipover cases, a careful evaluation of the history and scene and autopsy findings such as the crushing nature of the skull fractures and distribution of injury, can solve this problem. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Neuroimaging in normal pressure hydrocephalus

PubMed Central

Damasceno, Benito Pereira

2015-01-01

Normal pressure hydrocephalus (NPH) is a syndrome characterized by the triad of gait disturbance, mental deterioration and urinary incontinence, associated with ventriculomegaly and normal cerebrospinal fluid (CSF) pressure. The clinical presentation (triad) may be atypical or incomplete, or mimicked by other diseases, hence the need for supplementary tests, particularly to predict postsurgical outcome, such as CSF tap-tests and computed tomography (CT) or magnetic resonance imaging (MRI). The CSF tap-test, especially the 3 to 5 days continuous external lumbar drainage of at least 150 ml/day, is the only procedure that simulates the effect of definitive shunt surgery, with high sensitivity (50-100%) and high positive predictive value (80-100%). According to international guidelines, the following are CT or MRI signs decisive for NPH diagnosis and selection of shunt-responsive patients: ventricular enlargement disproportionate to cerebral atrophy (Evans index >0.3), and associated ballooning of frontal horns; periventricular hyperintensities; corpus callosum thinning and elevation, with callosal angle between 40º and 90º; widening of temporal horns not fully explained by hippocampal atrophy; and aqueductal or fourth ventricular flow void; enlarged Sylvian fissures and basal cistern, and narrowing of sulci and subarachnoid spaces over the high convexity and midline surface of the brain. On the other hand, other imaging methods such as radionuclide cisternography, SPECT, PET, and also DTI or resting-state functional MRI, although suitable for NPH diagnosis, do not yet provide improved accuracy for identifying shunt-responsive cases. PMID:29213984

The brain in myotonic dystrophy 1 and 2: evidence for a predominant white matter disease

PubMed Central

Weber, Bernd; Schoene-Bake, Jan-Christoph; Roeske, Sandra; Mirbach, Sandra; Anspach, Christian; Schneider-Gold, Christiane; Betz, Regina C.; Helmstaedter, Christoph; Tittgemeyer, Marc; Klockgether, Thomas; Kornblum, Cornelia

2011-01-01

Myotonic dystrophy types 1 and 2 are progressive multisystemic disorders with potential brain involvement. We compared 22 myotonic dystrophy type 1 and 22 myotonic dystrophy type 2 clinically and neuropsychologically well-characterized patients and a corresponding healthy control group using structural brain magnetic resonance imaging at 3 T (T1/T2/diffusion-weighted). Voxel-based morphometry and diffusion tensor imaging with tract-based spatial statistics were applied for voxel-wise analysis of cerebral grey and white matter affection (Pcorrected < 0.05). We further examined the association of structural brain changes with clinical and neuropsychological data. White matter lesions rated visually were more prevalent and severe in myotonic dystrophy type 1 compared with controls, with frontal white matter most prominently affected in both disorders, and temporal lesions restricted to myotonic dystrophy type 1. Voxel-based morphometry analyses demonstrated extensive white matter involvement in all cerebral lobes, brainstem and corpus callosum in myotonic dystrophy types 1 and 2, while grey matter decrease (cortical areas, thalamus, putamen) was restricted to myotonic dystrophy type 1. Accordingly, we found more prominent white matter affection in myotonic dystrophy type 1 than myotonic dystrophy type 2 by diffusion tensor imaging. Association fibres throughout the whole brain, limbic system fibre tracts, the callosal body and projection fibres (e.g. internal/external capsules) were affected in myotonic dystrophy types 1 and 2. Central motor pathways were exclusively impaired in myotonic dystrophy type 1. We found mild executive and attentional deficits in our patients when neuropsychological tests were corrected for manual motor dysfunctioning. Regression analyses revealed associations of white matter affection with several clinical parameters in both disease entities, but not with neuropsychological performance. We showed that depressed mood and fatigue were more prominent in patients with myotonic dystrophy type 1 with less white matter affection (early disease stages), contrary to patients with myotonic dystrophy type 2. Thus, depression in myotonic dystrophies might be a reactive adjustment disorder rather than a direct consequence of structural brain damage. Associations of white matter affection with age/disease duration as well as patterns of cerebral water diffusion parameters pointed towards an ongoing process of myelin destruction and/or axonal loss in our cross-sectional study design. Our data suggest that both myotonic dystrophy types 1 and 2 are serious white matter diseases with prominent callosal body and limbic system affection. White matter changes dominated the extent of grey matter changes, which might argue against Wallerian degeneration as the major cause of white matter affection in myotonic dystrophies. PMID:22131273

Representation and disconnection in imaginal neglect.

PubMed

Rode, G; Cotton, F; Revol, P; Jacquin-Courtois, S; Rossetti, Y; Bartolomeo, P

2010-08-01

Patients with neglect failure to detect, orient, or respond to stimuli from a spatially confined region, usually on their left side. Often, the presence of perceptual input increases left omissions, while sensory deprivation decreases them, possibly by removing attention-catching right-sided stimuli (Bartolomeo, 2007). However, such an influence of visual deprivation on representational neglect was not observed in patients while they were imagining a map of France (Rode et al., 2007). Therefore, these patients with imaginal neglect either failed to generate the left side of mental images (Bisiach & Luzzatti, 1978), or suffered from a co-occurrence of deficits in automatic (bottom-up) and voluntary (top-down) orienting of attention. However, in Rode et al.'s experiment visual input was not directly relevant to the task; moreover, distraction from visual input might primarily manifest itself when representation guides somatomotor actions, beyond those involved in the generation and mental exploration of an internal map (Thomas, 1999). To explore these possibilities, we asked a patient with right hemisphere damage, R.D., to explore visual and imagined versions of a map of France in three conditions: (1) 'imagine the map in your mind' (imaginal); (2) 'describe a real map' (visual); and (3) 'list the names of French towns' (propositional). For the imaginal and visual conditions, verbal and manual pointing responses were collected; the task was also given before and after mental rotation of the map by 180 degrees . R.D. mentioned more towns on the right side of the map in the imaginal and visual conditions, but showed no representational deficit in the propositional condition. The rightward inner exploration bias in the imaginal and visual conditions was similar in magnitude and was not influenced by mental rotation or response type (verbal responses or manual pointing to locations on a map), thus suggesting that the representational deficit was robust and independent of perceptual input in R.D. Structural and diffusion MRI demonstrated damage to several white matter tracts in the right hemisphere and to the splenium of corpus callosum. A second right-brain damaged patient (P.P.), who showed signs of visual but not imaginal neglect, had damage to the same intra-hemispheric tracts, but the callosal connections were spared. Imaginal neglect in R.D. may result from fronto-parietal dysfunction impairing orientation towards left-sided items and posterior callosal disconnection preventing the symmetrical processing of spatial information from long-term memory. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

Central nervous system abnormalities in Fanconi anaemia: patterns and frequency on magnetic resonance imaging

PubMed Central

Alston, Robert; Wright, Neville B; Chandler, Kate; Bonney, Denise; Wynn, Robert F; Will, Andrew M; Punekar, Maqsood; Loughran, Sean; Kilday, John-Paul; Schindler, Detlev; Patel, Leena; Meyer, Stefan

2015-01-01

Objective: Fanconi anaemia (FA) is an inherited disease associated with congenital and developmental abnormalities resulting from the disruption of a multigenic DNA damage response pathway. This study aimed to define the MRI appearances of the brain in patients with FA in correlation with their genetic and clinical features. Methods: A review of the brain MRI in 20 patients with FA was performed. Pituitary size and frequencies of the radiological findings of individuals with FA and age-matched controls were determined. Results: Abnormalities were identified in 18 (90%) patients with FA, the commonest being a small pituitary (68%, p < 0.01 females and p < 0.001 males). In five cases (25%, p = 0.02), the pituitary morphology was also abnormal. Posterior fossa abnormalities were seen in six cases (30%, p = 0.01) including Chiari I malformation (n = 3), Dandy–Walker variant (n = 2) and cerebellar atrophy (n = 2). Six patients (30%, p = 0.01) had morphological structural variation of the corpus callosum (CC). Conclusion: The incidence of central nervous system (CNS) abnormalities in FA is higher than previously reported, with a midline predominance that points to impact in the early stages of CNS development. MRI brain imaging is important for endocrine assessment and pre-transplant evaluation and can make an important contribution to clinical decision-making. Advances in knowledge: The incidence of brain structural abnormalities in FA is higher than previously reported, with abnormalities of the posterior fossa, CC and pituitary being common. There is an association with gender and reduction in pituitary size which does not strongly correlate with biochemically evident endocrine abnormality. PMID:26369989

Exploratory analysis of diffusion tensor imaging in children with attention deficit hyperactivity disorder: evidence of abnormal white matter structure.

PubMed

Pastura, Giuseppe; Doering, Thomas; Gasparetto, Emerson Leandro; Mattos, Paulo; Araújo, Alexandra Prüfer

2016-06-01

Abnormalities in the white matter microstructure of the attentional system have been implicated in the aetiology of attention deficit hyperactivity disorder (ADHD). Diffusion tensor imaging (DTI) is a promising magnetic resonance imaging (MRI) technology that has increasingly been used in studies of white matter microstructure in the brain. The main objective of this work was to perform an exploratory analysis of white matter tracts in a sample of children with ADHD versus typically developing children (TDC). For this purpose, 13 drug-naive children with ADHD of both genders underwent MRI using DTI acquisition methodology and tract-based spatial statistics. The results were compared to those of a sample of 14 age- and gender-matched TDC. Lower fractional anisotropy was observed in the splenium of the corpus callosum, right superior longitudinal fasciculus, bilateral retrolenticular part of the internal capsule, bilateral inferior fronto-occipital fasciculus, left external capsule and posterior thalamic radiation (including right optic radiation). We conclude that white matter tracts in attentional and motor control systems exhibited signs of abnormal microstructure in this sample of drug-naive children with ADHD.

Magnetic resonance imaging findings and prognosis of gastric-type mucinous adenocarcinoma (minimal deviation adenocarcinoma or adenoma malignum) of the uterine corpus: Two case reports.

PubMed

Hino, Mayo; Yamaguchi, Ken; Abiko, Kaoru; Yoshioka, Yumiko; Hamanishi, Junzo; Kondoh, Eiji; Koshiyama, Masafumi; Baba, Tsukasa; Matsumura, Noriomi; Minamiguchi, Sachiko; Kido, Aki; Konishi, Ikuo

2016-05-01

Our group previously documented the first, very rare case of primary gastric-type mucinous adenocarcinoma of the uterine corpus. Although this type of endometrial cancer appears to be similar to the gastric-type adenocarcinoma of the uterine cervix, its main symptoms, appearance on magnetic resonance imaging (MRI) and prognosis have not been fully elucidated due to its rarity. We herein describe an additional case of gastric-type mucinous adenocarcinoma of the endometrium and review the relevant literature. The two cases at our institution (Kyoto University Hospital, Kyoto, Japan) involved postmenopausal women with a primary complaint of abnormal genital bleeding. Microscopic examination of the hysterectomy specimens indicated a highly differentiated mucinous adenocarcinoma with a desmoplastic stromal reaction. Immunohistochemistry for HIK1083 and/or MUC6 was positive in both cases, suggesting a gastric phenotype. Both patients were diagnosed at an advanced stage, they relapsed or recurred immediately after adjuvant chemotherapy, and eventually succumbed to the disease. The main symptom of gastric-type mucinous adenocarcinoma of the uterine cervix is watery discharge, whereas abnormal genital bleeding in addition to watery discharge is mainly observed in the mucinous type of endometrial adenocarcinoma. Cystic cavities in the tumor are present on MRI in cases of endometrial origin, and prognosis is very poor due to resistance to chemotherapy. Thus, gastric-type mucinous adenocarcinoma of the uterine endometrium exhibits a clinical behavior that is similar to tumors originating from the uterine cervix, but is associated with distinguishing clinical symptoms. The incidence of gastric-type endometrial adenocarcinoma may be higher than expected.

Corpus callosum vasculature predicts white matter microstructure abnormalities following pediatric mild traumatic brain injury.

PubMed

Wendel, Kara M; Lee, Jeong Bin; Affeldt, Bethann; Hamer, Mary; Harahap-Carrillo, Indira S; Pardo, Andrea C; Obenaus, Andre

2018-05-09

Emerging data suggest that pediatric traumatic brain injury (TBI) is associated with impaired developmental plasticity and poorer neuropsychological outcomes than adults with similar head injuries. Unlike adult mild TBI (mTBI), the effects of mTBI on white matter (WM) microstructure and vascular supply are not well-understood in the pediatric population. The cerebral vasculature plays an important role providing necessary nutrients and removing waste. To address this critical element, we examined the microstructure of the corpus callosum (CC) following pediatric mTBI using diffusion tensor imaging (DTI), and investigated myelin, oligodendrocytes, and vasculature of WM with immunohistochemistry. We hypothesized that pediatric mTBI leads to abnormal WM microstructure and impacts the vasculature within the CC, and that these alterations to WM vasculature contribute to the long-term altered microstructure. We induced a closed head injury mTBI at postnatal day 14, then at 4, 14, and 60 days post injury (DPI) mice were sacrificed for analysis. We observed persistent changes in apparent diffusion coefficient (ADC) within the ipsilateral CC following mTBI, indicating microstructural changes, but surprisingly changes in myelin and oligodendrocyte densities were minimal. However, vasculature features of the ipsilateral CC such as vessel density, length, and number of junctions were persistently altered following mTBI. Correlative analysis showed a strong inverse relationship between ADC and vessel density at 60 DPI, suggesting increased vessel density following mTBI may restrict WM diffusion characteristics. Our findings suggest that WM vasculature contributes to the long-term microstructural changes within the ipsilateral CC following mTBI.

Distributed abnormalities of brain white matter architecture in patients with dominant optic atrophy and OPA1 mutations.

PubMed

Rocca, Maria A; Bianchi-Marzoli, Stefania; Messina, Roberta; Cascavilla, Maria Lucia; Zeviani, Massimo; Lamperti, Costanza; Milesi, Jacopo; Carta, Arturo; Cammarata, Gabriella; Leocani, Letizia; Lamantea, Eleonora; Bandello, Francesco; Comi, Giancarlo; Falini, Andrea; Filippi, Massimo

2015-05-01

Using advanced MRI techniques, we investigated the presence and topographical distribution of brain grey matter (GM) and white matter (WM) alterations in dominant optic atrophy (DOA) patients with genetically proven OPA1 mutation as well as their correlation with clinical and neuro-ophthalmologic findings. Nineteen DOA patients underwent neurological, neuro-ophthalmologic and brainstem auditory evoked potentials (BAEP) evaluations. Voxel-wise methods were applied to assess regional GM and WM abnormalities in patients compared to 20 healthy controls. Visual acuity was reduced in 16 patients. Six DOA patients (4 with missense mutations) had an abnormal I peripheral component (auditory nerve) at BAEP. Compared to controls, DOA patients had significant atrophy of the optic nerves (p < 0.0001). Voxel-based morphometry (VBM) analysis showed that, compared to controls, DOA patients had significant WM atrophy of the chiasm and optic tracts; whereas no areas of GM atrophy were found. Tract-based spatial statistics (TBSS) analysis showed that compared to controls, DOA patients had significantly lower mean diffusivity, axial and radial diffusivity in the WM of the cerebellum, brainstem, thalamus, fronto-occipital-temporal lobes, including the cingulum, corpus callosum, corticospinal tract and optic radiation bilaterally. No abnormalities of fractional anisotropy were detected. No correlations were found between volumetric and diffusivity abnormalities quantified with MRI and clinical and neuro-ophthalmologic measures of disease severity. Consistently with pathological studies, tissue loss in DOA patients is limited to anterior optic pathways reflecting retinal ganglion cell degeneration. Distributed abnormalities of diffusivity indexes might reflect abnormal intracellular mitochondrial morphology as well as alteration of protein levels due to OPA1 mutations.

Volume reduction of the corpus callosum and its relationship with deficits in interhemispheric transfer of information in recent-onset psychosis.

PubMed

Chaim, Tiffany M; Schaufelberger, Maristela S; Ferreira, Luiz K; Duran, Fábio L S; Ayres, Adriana M; Scazufca, Marcia; Menezes, Paulo R; Amaro, Edson; Leite, Claudia C; Murray, Robin M; McGuire, Philip K; Rushe, Teresa M; Busatto, Geraldo F

2010-10-30

The present study aimed to investigate the presence of corpus callosum (CC) volume deficits in a population-based recent-onset psychosis (ROP) sample, and whether CC volume relates to interhemispheric communication deficits. For this purpose, we used voxel-based morphometry comparisons of magnetic resonance imaging data between ROP (n =122) and healthy control (n = 94) subjects. Subgroups (38 ROP and 39 controls) were investigated for correlations between CC volumes and performance on the Crossed Finger Localization Test (CFLT). Significant CC volume reductions in ROP subjects versus controls emerged after excluding substance misuse and non-right-handedness. CC reductions retained significance in the schizophrenia subgroup but not in affective psychoses subjects. There were significant positive correlations between CC volumes and CFLT scores in ROP subjects, specifically in subtasks involving interhemispheric communication. From these results, we can conclude that CC volume reductions are present in association with ROP. The relationship between such deficits and CFLT performance suggests that interhemispheric communication impairments are directly linked to CC abnormalities in ROP. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Endocrinology of recurrent pregnancy loss.

PubMed

Arredondo, Francisco; Noble, Luis S

2006-02-01

Following implantation, the maintenance of the pregnancy is dependent on a multitude of endocrinological events that will eventually aid in the successful growth and development of the fetus. Although the great majority of pregnant women have no pre-existing endocrine abnormalities, a small number of women can have certain endocrine alterations that could potentially lead to recurrent pregnancy losses. It is estimated that approximately 8 to 12% of all pregnancy losses are the result of endocrine factors. During the preimplantation period, the uterus undergoes important developmental changes stimulated by estrogen, and more importantly, progesterone. Progesterone is essential for the successful implantation and maintenance of pregnancy. Therefore, disorders related to inadequate progesterone secretion by the corpus luteum are likely to affect the outcome of the pregnancy. Luteal phase deficiency, hyperprolactinemia, and polycystic ovarian syndrome are some examples. Several other endocrinological abnormalities such as thyroid disease, hypoparathyroidism, uncontrolled diabetes, and decreased ovarian reserve have been implicated as etiologic factors for recurrent pregnancy loss.

Ethanol specifically decreases peroxisome proliferator activated receptor beta in B12 oligodendrocyte-like cells.

PubMed

Leisewitz, Andrea V; Jung, Juan E; Perez-Alzola, Patricia; Fuenzalida, Karen M; Roth, Alejandro; Inestrosa, Nibaldo C; Bronfman, Miguel

2003-04-01

Peroxisome proliferator activated receptors (PPARs) are nuclear receptors that control important genes involved in lipid metabolism. Their role in nerve cells is uncertain, although anomalous myelination of the corpus callosum has been described in the PPARbeta-null mouse, and abnormalities of this tissue have been documented in fetal alcohol syndrome in humans. We report here that ethanol treatment of B12 oligodendrocyte-like cells induces a concentration- and time-dependent decrease in the mRNA and protein levels of PPARbeta, with no effect on PPARalpha or PPARgamma. The effect on PPARbeta is seen as an increase in mRNA degradation, as assessed by run-off assays, due to a significant decrease in PPARbeta mRNA half-life, with no observed changes in intracellular localization. Our results suggest a possible link between PPARbeta function and ethanol-induced abnormal myelination in oligodendrocytes.

Lysosomal abnormalities in hereditary spastic paraplegia types SPG15 and SPG11

PubMed Central

Renvoisé, Benoît; Chang, Jaerak; Singh, Rajat; Yonekawa, Sayuri; FitzGibbon, Edmond J; Mankodi, Ami; Vanderver, Adeline; Schindler, Alice B; Toro, Camilo; Gahl, William A; Mahuran, Don J; Blackstone, Craig; Pierson, Tyler Mark

2014-01-01

Objective Hereditary spastic paraplegias (HSPs) are among the most genetically diverse inherited neurological disorders, with over 70 disease loci identified (SPG1-71) to date. SPG15 and SPG11 are clinically similar, autosomal recessive disorders characterized by progressive spastic paraplegia along with thin corpus callosum, white matter abnormalities, cognitive impairment, and ophthalmologic abnormalities. Furthermore, both have been linked to early-onset parkinsonism. Methods We describe two new cases of SPG15 and investigate cellular changes in SPG15 and SPG11 patient-derived fibroblasts, seeking to identify shared pathogenic themes. Cells were evaluated for any abnormalities in cell division, DNA repair, endoplasmic reticulum, endosomes, and lysosomes. Results Fibroblasts prepared from patients with SPG15 have selective enlargement of LAMP1-positive structures, and they consistently exhibited abnormal lysosomal storage by electron microscopy. A similar enlargement of LAMP1-positive structures was also observed in cells from multiple SPG11 patients, though prominent abnormal lysosomal storage was not evident. The stabilities of the SPG15 protein spastizin/ZFYVE26 and the SPG11 protein spatacsin were interdependent. Interpretation Emerging studies implicating these two proteins in interactions with the late endosomal/lysosomal adaptor protein complex AP-5 are consistent with shared abnormalities in lysosomes, supporting a converging mechanism for these two disorders. Recent work with Zfyve26−/− mice revealed a similar phenotype to human SPG15, and cells in these mice had endolysosomal abnormalities. SPG15 and SPG11 are particularly notable among HSPs because they can also present with juvenile parkinsonism, and this lysosomal trafficking or storage defect may be relevant for other forms of parkinsonism associated with lysosomal dysfunction. PMID:24999486

Physical Activity Behavioral Intervention in Obese Endometrial Cancer Survivors

ClinicalTrials.gov

2015-10-14

Stage IA Uterine Corpus Cancer; Stage IB Uterine Corpus Cancer; Stage II Uterine Corpus Cancer; Stage IIIA Uterine Corpus Cancer; Stage IIIB Uterine Corpus Cancer; Stage IIIC Uterine Corpus Cancer; Stage IVA Uterine Corpus Cancer; Stage IVB Uterine Corpus Cancer

Auditory cortex asymmetry, altered minicolumn spacing and absence of ageing effects in schizophrenia

PubMed Central

Casanova, Manuel F.; Switala, Andy E.; Crow, Timothy J.

2008-01-01

The superior temporal gyrus, which contains the auditory cortex, including the planum temporale, is the most consistently altered neocortical structure in schizophrenia (Shenton ME, Dickey CC, Frumin M, McCarley RW. A review of MRI findings in schizophrenia. Schizophr Res 2001; 49: 1–52). Auditory hallucinations are associated with abnormalities in this region and activation in Heschl's gyrus. Our review of 34 MRI and 5 post-mortem studies of planum temporale reveals that half of those measuring region size reported a change in schizophrenia, usually consistent with a reduction in the left hemisphere and a relative increase in the right hemisphere. Furthermore, female subjects are under-represented in the literature and insight from sex differences may be lost. Here we present evidence from post-mortem brain (N = 21 patients, compared with 17 previously reported controls) that normal age-associated changes in planum temporale are not found in schizophrenia. These age-associated differences are reported in an adult population (age range 29–90 years) and were not found in the primary auditory cortex of Heschl's gyrus, indicating that they are selective to the more plastic regions of association cortex involved in cognition. Areas and volumes of Heschl's gyrus and planum temporale and the separation of the minicolumns that are held to be the structural units of the cerebral cortex were assessed in patients. Minicolumn distribution in planum temporale and Heschl's gyrus was assessed on Nissl-stained sections by semi-automated microscope image analysis. The cortical surface area of planum temporale in the left hemisphere (usually asymmetrically larger) was positively correlated with its constituent minicolumn spacing in patients and controls. Surface area asymmetry of planum temporale was reduced in patients with schizophrenia by a reduction in the left hemisphere (F = 7.7, df 1,32, P < 0.01). The relationship between cortical asymmetry and the connecting, interhemispheric callosal white matter was also investigated; minicolumn asymmetry of both Heschl's gyrus and planum temporale was correlated with axon number in the wrong subregions of the corpus callosum in patients. The spacing of minicolumns was altered in a sex-dependent manner due to the absence of age-related minicolumn thinning in schizophrenia. This is interpreted as a failure of adult neuroplasticity that maintains neuropil space. The arrested capacity to absorb anomalous events and cognitive demands may confer vulnerability to schizophrenic symptoms when adult neuroplastic demands are not met. PMID:18819990

Mechanisms of callose deposition in rice regulated by exogenous abscisic acid and its involvement in rice resistance to Nilaparvata lugens Stål (Hemiptera: Delphacidae).

PubMed

Liu, Jinglan; Du, Haitao; Ding, Xu; Zhou, Yaodong; Xie, Pengfei; Wu, Jincai

2017-12-01

Callose is a plant cell wall polysaccharide controlled by β-1,3-glucanase and synthase. Abscisic acid (ABA) is an important plant hormone. Exogenous ABA promotes rice resistance to pests. Whether exogenous ABA could reduce the decline in rice yield after brown planthopper (Nilaparvata lugens Stål; BPH) feeding is an important question, however, the mechanisms behind rice resistance induced by ABA remain obscure. Electronic penetration graph (EPG) recording indicated a significant increase in rice resistance to BPH, and the number of BPH eggs decreased significantly upon application of exogenous ABA. As the concentration of ABA increased, the reduction in rice yield decreased significantly after BPH feeding. Further studies showed that β-1,3-glucanase activity was significantly lower, but synthase activity was higher after ABA treatment than in controls. Our results demonstrated that exogenous ABA suppressed β-1,3-glucanase and induced synthase activity, and promoted callose deposition. This is an important defense mechanism that prevents BPH from ingesting phloem sap. These studies provide support for an insect-resistance mechanism after ABA treatment and provide a reference for the integrated management of other piercing-sucking pests. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

AUXIN RESPONSE FACTOR17 Is Essential for Pollen Wall Pattern Formation in Arabidopsis1[C][W][OA

PubMed Central

Yang, Jun; Tian, Lei; Sun, Ming-Xi; Huang, Xue-Yong; Zhu, Jun; Guan, Yue-Feng; Jia, Qi-Shi; Yang, Zhong-Nan

2013-01-01

In angiosperms, pollen wall pattern formation is determined by primexine deposition on the microspores. Here, we show that AUXIN RESPONSE FACTOR17 (ARF17) is essential for primexine formation and pollen development in Arabidopsis (Arabidopsis thaliana). The arf17 mutant exhibited a male-sterile phenotype with normal vegetative growth. ARF17 was expressed in microsporocytes and microgametophytes from meiosis to the bicellular microspore stage. Transmission electron microscopy analysis showed that primexine was absent in the arf17 mutant, which leads to pollen wall-patterning defects and pollen degradation. Callose deposition was also significantly reduced in the arf17 mutant, and the expression of CALLOSE SYNTHASE5 (CalS5), the major gene for callose biosynthesis, was approximately 10% that of the wild type. Chromatin immunoprecipitation and electrophoretic mobility shift assays showed that ARF17 can directly bind to the CalS5 promoter. As indicated by the expression of DR5-driven green fluorescent protein, which is an synthetic auxin response reporter, auxin signaling appeared to be specifically impaired in arf17 anthers. Taken together, our results suggest that ARF17 is essential for pollen wall patterning in Arabidopsis by modulating primexine formation at least partially through direct regulation of CalS5 gene expression. PMID:23580594

Human Brain Abnormalities Associated With Prenatal Alcohol Exposure and Fetal Alcohol Spectrum Disorder

PubMed Central

Jarmasz, Jessica S.; Basalah, Duaa A.; Chudley, Albert E.; Del Bigio, Marc R.

2017-01-01

Abstract Fetal alcohol spectrum disorder (FASD) is a common neurodevelopmental problem, but neuropathologic descriptions are rare and focused on the extreme abnormalities. We conducted a retrospective survey (1980–2016) of autopsies on 174 individuals with prenatal alcohol exposure or an FASD diagnosis. Epidemiologic details and neuropathologic findings were categorized into 5 age groups. Alcohol exposure was difficult to quantify. When documented, almost all mothers smoked tobacco, many abused other substances, and prenatal care was poor or nonexistent. Placental abnormalities were common (68%) in fetal cases. We identified micrencephaly (brain weight <5th percentile) in 31, neural tube defects in 5, isolated hydrocephalus in 6, corpus callosum defects in 6 (including some with complex anomalies), probable prenatal ischemic lesions in 5 (excluding complications of prematurity), minor subarachnoid heterotopias in 4, holoprosencephaly in 1, lissencephaly in 1, and cardiac anomalies in 26 cases. The brain abnormalities associated with prenatal alcohol exposure are varied; cause–effect relationships cannot be determined. FASD is likely not a monotoxic disorder. The animal experimental literature, which emphasizes controlled exposure to ethanol alone, is therefore inadequate. Prevention must be the main societal goal, however, a clear understanding of the neuropathology is necessary for provision of care to individuals already affected. PMID:28859338

Radiation Therapy, Paclitaxel, and Carboplatin in Treating Patients With High-Risk Endometrial Cancer

ClinicalTrials.gov

2016-01-11

Endometrial Adenocarcinoma; Stage IA Uterine Corpus Cancer; Stage IB Uterine Corpus Cancer; Stage II Uterine Corpus Cancer; Stage IIIA Uterine Corpus Cancer; Stage IIIB Uterine Corpus Cancer; Stage IIIC Uterine Corpus Cancer; Stage IVA Uterine Corpus Cancer; Stage IVB Uterine Corpus Cancer

Early local differentiation of the cell wall matrix defines the contact sites in lobed mesophyll cells of Zea mays.

PubMed

Giannoutsou, E; Sotiriou, P; Apostolakos, P; Galatis, B

2013-10-01

The morphogenesis of lobed mesophyll cells (MCs) is highly controlled and coupled with intercellular space formation. Cortical microtubule rings define the number and the position of MC isthmi. This work investigated early events of MC morphogenesis, especially the mechanism defining the position of contacts between MCs. The distributions of plasmodesmata, the hemicelluloses callose and (1 → 3,1 → 4)-β-d-glucans (MLGs) and the pectin epitopes recognized by the 2F4, JIM5, JIM7 and LM6 antibodies were studied in the cell walls of Zea mays MCs. Matrix cell wall polysaccharides were immunolocalized in hand-made sections and in sections of material embedded in LR White resin. Callose was also localized using aniline blue in hand-made sections. Plasmodesmata distribution was examined by transmission electron microscopy. Before reorganization of the dispersed cortical microtubules into microtubule rings, particular bands of the longitudinal MC walls, where the MC contacts will form, locally differentiate by selective (1) deposition of callose and the pectin epitopes recognized by the 2F4, LM6, JIM5 and JIM7 antibodies, (2) degradation of MLGs and (3) formation of secondary plasmodesmata clusterings. This cell wall matrix differentiation persists in cell contacts of mature MCs. Simultaneously, the wall bands between those of future cell contacts differentiate with (1) deposition of local cell wall thickenings including cellulose microfibrils, (2) preferential presence of MLGs, (3) absence of callose and (4) transient presence of the pectins identified by the JIM5 and JIM7 antibodies. The wall areas between cell contacts expand determinately to form the cell isthmi and the cell lobes. The morphogenesis of lobed MCs is characterized by the early patterned differentiation of two distinct cell wall subdomains, defining the sites of the future MC contacts and of the future MC isthmi respectively. This patterned cell wall differentiation precedes cortical microtubule reorganization and may define microtubule ring disposition.

Cabozantinib and Nivolumab in Treating Patients With Advanced, Recurrent or Metastatic Endometrial Cancer

ClinicalTrials.gov

2018-06-13

Recurrent Uterine Corpus Carcinoma; Stage III Uterine Corpus Cancer AJCC v7; Stage IIIA Uterine Corpus Cancer AJCC v7; Stage IIIB Uterine Corpus Cancer AJCC v7; Stage IIIC Uterine Corpus Cancer AJCC v7; Stage IIIC1 Uterine Corpus Cancer AJCC v7; Stage IIIC2 Uterine Corpus Cancer AJCC v7; Stage IV Uterine Corpus Cancer AJCC v7; Stage IVA Uterine Corpus Cancer AJCC v7; Stage IVB Uterine Corpus Cancer AJCC v7

Nervous System Abnormalities and Legionnaire's Disease.

PubMed

Halperin, John J

2017-03-01

Although patients with Legionnaire's disease frequently develop alterations of consciousness, this is no more frequent than in patients hospitalized with other, equally severe forms of bacterial pneumonia. Legionella meningitis occurs rarely, if ever. Patients with Legionnaire's are susceptible to critical illness polyneuropathy/myopathy, as are other critically ill patients. Legionnaire's patients may develop MRI hyperdensities in the splenium of the corpus callosum, as may other patients with severe infections. Patients with Legionnaire's may be at increased risk of, and rarely develop, immune-mediated multifocal brain (acute disseminated encephalomyelitis) or peripheral nerve disease (Guillain-Barré syndrome). Copyright © 2016 Elsevier Inc. All rights reserved.

Microtubule-Actin Crosslinking Factor 1 Is Required for Dendritic Arborization and Axon Outgrowth in the Developing Brain.

PubMed

Ka, Minhan; Kim, Woo-Yang

2016-11-01

Dendritic arborization and axon outgrowth are critical steps in the establishment of neural connectivity in the developing brain. Changes in the connectivity underlie cognitive dysfunction in neurodevelopmental disorders. However, molecules and associated mechanisms that play important roles in dendritic and axon outgrowth in the brain are only partially understood. Here, we show that microtubule-actin crosslinking factor 1 (MACF1) regulates dendritic arborization and axon outgrowth of developing pyramidal neurons by arranging cytoskeleton components and mediating GSK-3 signaling. MACF1 deletion using conditional mutant mice and in utero gene transfer in the developing brain markedly decreased dendritic branching of cortical and hippocampal pyramidal neurons. MACF1-deficient neurons showed reduced density and aberrant morphology of dendritic spines. Also, loss of MACF1 impaired the elongation of callosal axons in the brain. Actin and microtubule arrangement appeared abnormal in MACF1-deficient neurites. Finally, we found that GSK-3 is associated with MACF1-controlled dendritic differentiation. Our findings demonstrate a novel role for MACF1 in neurite differentiation that is critical to the creation of neuronal connectivity in the developing brain.

Callosal Function in Pediatric Traumatic Brain Injury Linked to Disrupted White Matter Integrity

PubMed Central

Dennis, Emily L.; Ellis, Monica U.; Marion, Sarah D.; Jin, Yan; Moran, Lisa; Olsen, Alexander; Kernan, Claudia; Babikian, Talin; Mink, Richard; Babbitt, Christopher; Johnson, Jeffrey; Giza, Christopher C.; Asarnow, Robert F.

2015-01-01

Traumatic brain injury (TBI) often results in traumatic axonal injury and white matter (WM) damage, particularly to the corpus callosum (CC). Damage to the CC can lead to impaired performance on neurocognitive tasks, but there is a high degree of heterogeneity in impairment following TBI. Here we examined the relation between CC microstructure and function in pediatric TBI. We used high angular resolution diffusion-weighted imaging (DWI) to evaluate the structural integrity of the CC in humans following brain injury in a sample of 32 children (23 males and 9 females) with moderate-to-severe TBI (msTBI) at 1–5 months postinjury, compared with well matched healthy control children. We assessed CC function through interhemispheric transfer time (IHTT) as measured using event-related potentials (ERPs), and related this to DWI measures of WM integrity. Finally, the relation between DWI and IHTT results was supported by additional results of neurocognitive performance assessed using a single composite performance scale. Half of the msTBI participants (16 participants) had significantly slower IHTTs than the control group. This slow IHTT group demonstrated lower CC integrity (lower fractional anisotropy and higher mean diffusivity) and poorer neurocognitive functioning than both the control group and the msTBI group with normal IHTTs. Lower fractional anisotropy—a common sign of impaired WM—and slower IHTTs also predicted poor neurocognitive function. This study reveals that there is a subset of pediatric msTBI patients during the post-acute phase of injury who have markedly impaired CC functioning and structural integrity that is associated with poor neurocognitive functioning. SIGNIFICANCE STATEMENT Traumatic brain injury (TBI) is the primary cause of death and disability in children and adolescents. There is considerable heterogeneity in postinjury outcome, which is only partially explained by injury severity. Imaging biomarkers may help explain some of this variance, as diffusion weighted imaging is sensitive to the white matter disruption that is common after injury. The corpus callosum (CC) is one of the most commonly reported areas of disruption. In this multimodal study, we discovered a divergence within our pediatric moderate-to-severe TBI sample 1–5 months postinjury. A subset of the TBI sample showed significant impairment in CC function, which is supported by additional results showing deficits in CC structural integrity. This subset also had poorer neurocognitive functioning. Our research sheds light on postinjury heterogeneity. PMID:26180196

Thick corpus callosum in the second trimester can be transient and is of uncertain significance.

PubMed

Shinar, S; Har-Toov, J; Lerman-Sagie, T; Malinger, G

2016-10-01

Depiction of a thick corpus callosum (CC) in utero is rare, and is generally associated with severe brain anomalies. Our aim was to describe a group of fetuses diagnosed during second-trimester ultrasound examination as having an apparently isolated thick CC, which normalized subsequently in the cases followed to term. Among 59 fetuses referred to the Ob-Gyn Ultrasound Division of Lis Maternity Hospital with suspected callosal anomalies between January 2013 and June 2014, we identified nine cases with an apparently isolated thick CC for inclusion in this retrospective cohort study. Length and body thickness of the CC were compared with previously published nomograms. Fetuses with a suspected isolated thick CC were identified and followed until delivery or termination of pregnancy (TOP). Evaluation consisted of chromosomal analysis, at least one magnetic resonance imaging (MRI) examination and repeat ultrasound examinations. Postnatal evaluation included brain ultrasound examination, MRI when indicated and neurodevelopmental assessment through validated pediatric questionnaires. The nine fetuses were diagnosed with an apparently isolated thick CC at a mean gestational age of 23 + 5 (range, 21-29) weeks. Eight exhibited a CC body thickness ≥ 2SD above the mean for gestational age and one exhibited only a thickened genu. Six also exhibited a relatively short CC. Two patients opted for TOP but declined autopsy. In five of the seven remaining fetuses, the CC thickness normalized during follow-up. In the remaining two, the increased CC thickness was a variant of the cingulate sulcus. The CC length remained ≤ 2SD in five of the six fetuses with a short CC. Fetal MRI was performed and confirmed the diagnosis in six fetuses. The karyotype was normal in all fetuses. Short-term neurodevelopmental outcome was reported as normal in all six children with complete follow-up. Although the number of fetuses in our study is relatively small, it seems that an apparently isolated thick CC is not necessarily associated with poor prognosis. In such cases, a definitive diagnosis should not be reached based on a single measurement and repeat follow-up examinations during the third trimester are recommended. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.

Intrahemispheric white matter asymmetries: the missing link between brain structure and functional lateralization?

PubMed

Ocklenburg, Sebastian; Friedrich, Patrick; Güntürkün, Onur; Genç, Erhan

2016-07-01

Hemispheric asymmetries are a central principle of nervous system architecture and shape the functional organization of most cognitive systems. Structural gray matter asymmetries and callosal interactions have been identified as contributing neural factors but always fell short to constitute a full explanans. Meanwhile, recent advances in in vivo white matter tractography have unrevealed the asymmetrical organization of many intrahemispheric white matter pathways, which might serve as the missing link to explain the substrate of functional lateralization. By taking into account callosal interactions, gray matter asymmetries and asymmetrical interhemispheric pathways, we opt for a new triadic model that has the potential to explain many observations which cannot be elucidated within the current frameworks of lateralized cognition.

Clinical and mutational spectrum in Korean patients with Rubinstein-Taybi syndrome: the spectrum of brain MRI abnormalities.

PubMed

Lee, Jin Sook; Byun, Christine K; Kim, Hunmin; Lim, Byung Chan; Hwang, Hee; Choi, Ji Eun; Hwang, Yong Seung; Seong, Moon-Woo; Park, Sung Sup; Kim, Ki Joong; Chae, Jong-Hee

2015-04-01

Rubinstein-Taybi syndrome (RSTS) is one of the neurodevelopmental disorders caused by mutations of epigenetic genes. The CREBBP gene is the most common causative gene, encoding the CREB-binding protein with histone acetyltransferase (HAT) activity, an epigenetic modulator. To date, there have been few reports on the structural abnormalities of the brain in RSTS patients. In addition, there are no reports on the analysis of CREBBP mutations in Korean RSTS patients. We performed mutational analyses on 16 unrelated patients with RSTS, with diagnosis based on the typical clinical features. Their medical records and brain MRI images were reviewed retrospectively. Ten of 16 patients (62.5%) had mutations in the CREBBP gene. The mutations included five frameshift mutations (31.2%), two nonsense mutations (12.5%), and three multiexon deletions (18.8%). There were no remarkable significant differences in the clinical features between those with and without a CREBBP mutation, although brain MRI abnormalities were more frequently observed in those with a CREBBP mutation. Seven of 10 patients in whom brain imaging was performed had structural abnormalities, including Chiari malformation type 1, thinning of the corpus callosum, and delayed myelination. There were no differences in delayed development or cognitive impairment between those with and without abnormal brain images, while epilepsy was involved in two patients who had abnormalities on brain MRI images. We investigated the spectrum of CREBBP mutations in Korean patients with RSTS for the first time. Eight novel mutations extended the genetic spectrum of CREBBP mutations in RSTS patients. This is also the first study showing the prevalence and spectrum of abnormalities on brain MRI in RSTS patients. Copyright © 2014 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.

Temsirolimus With or Without Megestrol Acetate and Tamoxifen Citrate in Treating Patients With Advanced, Persistent, or Recurrent Endometrial Cancer

ClinicalTrials.gov

2017-04-11

Endometrial Carcinoma; Recurrent Uterine Corpus Carcinoma; Stage IIIA Uterine Corpus Cancer; Stage IIIB Uterine Corpus Cancer; Stage IIIC1 Uterine Corpus Cancer; Stage IIIC2 Uterine Corpus Cancer; Stage IVA Uterine Corpus Cancer; Stage IVB Uterine Corpus Cancer

Hypospadias anatomy: Elastosonographic evaluation of the normal and hypospadic penis.

PubMed

Camoglio, Francesco Saverio; Bruno, Costanza; Zambaldo, Silvia; Zampieri, Nicola

2016-08-01

Hypospadias is one of the most common congenital anomalies in childhood. The aim of this study is to apply elastosonography on normal and hypospadic penis to verify the structural differences in tissues composition and stiffness. We analyzed medical chart of patients treated at our Institution for hypospadias during the period December 2005 and December 2014 (group 1). Other two groups were enrolled for this study: group 2- patients with hypospadias waiting for surgery and group 3-patients without hypospadias. Inclusion and exclusion criteria were created; all patients underwent penile ultrasound and elastosonography. Elastographic index of elasticity was defined as soft, medium-hard or hard. We assigned the value 1 to soft tissue, 2 and 3 to medium-hard and hard respectively. During the study period 294 patients were treated for hypospadias. After reviewing medical chart 115 patients were considered for analysis (group 1). 22 patients were enrolled in group 2 and 38 patients were enrolled in group 3. Group 1: 7 proximal hypospadias, 29 penile hypospadias, 79 distal hypospadias. Patients with hypospadias had malformation also at corpus spongiosum and cavernosum respect to controls. Elastography showed a corpus spongiosum stiffness defined as medium-hard or hard in all cases of the pathologic group and soft in all the subjects of the control group (p < 0.05). Elastosonography showed how the hypospadia anatomy is deeply altered, even in an anatomical area far from meatal abnormality: corpus spongiosum in hypospadic penis seems to be globally stiffer and less elastic and cavernous corpora are less developed. Copyright © 2016 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.

Evidence for impaired plasticity after traumatic brain injury in the developing brain.

PubMed

Li, Nan; Yang, Ya; Glover, David P; Zhang, Jiangyang; Saraswati, Manda; Robertson, Courtney; Pelled, Galit

2014-02-15

The robustness of plasticity mechanisms during brain development is essential for synaptic formation and has a beneficial outcome after sensory deprivation. However, the role of plasticity in recovery after acute brain injury in children has not been well defined. Traumatic brain injury (TBI) is the leading cause of death and disability among children, and long-term disability from pediatric TBI can be particularly devastating. We investigated the altered cortical plasticity 2-3 weeks after injury in a pediatric rat model of TBI. Significant decreases in neurophysiological responses across the depth of the noninjured, primary somatosensory cortex (S1) in TBI rats, compared to age-matched controls, were detected with electrophysiological measurements of multi-unit activity (86.4% decrease), local field potential (75.3% decrease), and functional magnetic resonance imaging (77.6% decrease). Because the corpus callosum is a clinically important white matter tract that was shown to be consistently involved in post-traumatic axonal injury, we investigated its anatomical and functional characteristics after TBI. Indeed, corpus callosum abnormalities in TBI rats were detected with diffusion tensor imaging (9.3% decrease in fractional anisotropy) and histopathological analysis (14% myelination volume decreases). Whole-cell patch clamp recordings further revealed that TBI results in significant decreases in spontaneous firing rate (57% decrease) and the potential to induce long-term potentiation in neurons located in layer V of the noninjured S1 by stimulation of the corpus callosum (82% decrease). The results suggest that post-TBI plasticity can translate into inappropriate neuronal connections and dramatic changes in the function of neuronal networks.

Regional variation of white matter development in the cat brain revealed by ex vivo diffusion MR tractography.

PubMed

Dai, Guangping; Das, Avilash; Hayashi, Emiko; Chen, Qin; Takahashi, Emi

2016-11-01

Three-dimensional reconstruction of developing fiber pathways is essential to assessing the developmental course of fiber pathways in the whole brain. We applied diffusion spectrum imaging (DSI) tractography to five juvenile ex vivo cat brains at postnatal day (P) 35, when the degree of myelination varies across brain regions. We quantified diffusion properties (fractional anisotropy [FA] and apparent diffusion coefficient [ADC]) and other measurements (number, volume, and voxel count) on reconstructed pathways for projection (cortico-spinal and thalamo-cortical), corpus callosal, limbic (cingulum and fornix), and association (cortico-cortical) pathways, and characterized regional differences in maturation patterns by assessing diffusion properties. FA values were significantly higher in cortico-cortical pathways within the right hemisphere compared to those within the left hemisphere, while the other measurements for the cortico-cortical pathways within the hemisphere did not show asymmetry. ADC values were not asymmetric in both types of pathways. Interestingly, tract count and volume were significantly larger in the left thalamo-cortical pathways compared to the right thalamo-cortical pathways. The bilateral thalamo-cortical pathways showed high FA values compared to the other fiber pathways. On the other hand, ADC values did not show any differences across pathways studied. These results demonstrate that DSI tractography successfully depicted regional variations of white matter tracts during development when myelination is incomplete. Low FA and high ADC values in the cingulum bundle suggest that the cingulum bundle is less mature than the others at this developmental stage. Copyright © 2016 ISDN. Published by Elsevier Ltd. All rights reserved.

Voltage-sensitive-dye imaging of microstimulation-evoked neural activity through intracortical horizontal and callosal connections in cat visual cortex.

PubMed

Suzurikawa, Jun; Tani, Toshiki; Nakao, Masayuki; Tanaka, Shigeru; Takahashi, Hirokazu

2009-12-01

Recently, intrinsic signal optical imaging has been widely used as a routine procedure for visualizing cortical functional maps. We do not, however, have a well-established imaging method for visualizing cortical functional connectivity indicating spatio-temporal patterns of activity propagation in the cerebral cortex. In the present study, we developed a novel experimental setup for investigating the propagation of neural activities combining the intracortical microstimulation (ICMS) technique with voltage sensitive dye (VSD) imaging, and demonstrated the feasibility of this setup applying to the measurement of time-dependent intra- and inter-hemispheric spread of ICMS-evoked excitation in the cat visual cortices, areas 17 and 18. A microelectrode array for the ICMS was inserted with a specially designed easy-to-detach electrode holder around the 17/18 transition zones (TZs), where the left and right hemispheres were interconnected via the corpus callosum. The microelectrode array was stably anchored in agarose without any holder, which enabled us to visualize evoked activities even in the vicinity of penetration sites as well as in a wide recording region that covered a part of both hemispheres. The VSD imaging could successfully visualize ICMS-evoked excitation and subsequent propagation in the visual cortices contralateral as well as ipsilateral to the ICMS. Using the orientation maps as positional references, we showed that the activity propagation patterns were consistent with previously reported anatomical patterns of intracortical and interhemispheric connections. This finding indicates that our experimental system can serve for the investigation of cortical functional connectivity.

Whole-brain voxel-based morphometry in Kallmann syndrome associated with mirror movements.

PubMed

Koenigkam-Santos, M; Santos, A C; Borduqui, T; Versiani, B R; Hallak, J E C; Crippa, J A S; Castro, M

2008-10-01

There are 2 main hypotheses concerning the cause of mirror movements (MM) in Kallmann syndrome (KS): abnormal development of the primary motor system, involving the ipsilateral corticospinal tract; and lack of contralateral motor cortex inhibitory mechanisms, mainly through the corpus callosum. The purpose of our study was to determine white and gray matter volume changes in a KS population by using optimized voxel-based morphometry (VBM) and to investigate the relationship between the abnormalities and the presence of MM, addressing the 2 mentioned hypotheses. T1-weighted volumetric images from 21 patients with KS and 16 matched control subjects were analyzed with optimized VBM. Images were segmented and spatially normalized, and these deformation parameters were then applied to the original images before the second segmentation. Patients were divided into groups with and without MM, and a t test statistic was then applied on a voxel-by-voxel basis between the groups and controls to evaluate significant differences. When considering our hypothesis a priori, we found that 2 areas of increased gray matter volume, in the left primary motor and sensorimotor cortex, were demonstrated only in patients with MM, when compared with healthy controls. Regarding white matter alterations, no areas of altered volume involving the corpus callosum or the projection of the corticospinal tract were demonstrated. The VBM study did not show significant white matter changes in patients with KS but showed gray matter alterations in keeping with a hypertrophic response to a deficient pyramidal decussation in patients with MM. In addition, gray matter alterations were observed in patients without MM, which can represent more complex mechanisms determining the presence or absence of this symptom.

Magnetic resonance imaging findings and prognosis of gastric-type mucinous adenocarcinoma (minimal deviation adenocarcinoma or adenoma malignum) of the uterine corpus: Two case reports

PubMed Central

HINO, MAYO; YAMAGUCHI, KEN; ABIKO, KAORU; YOSHIOKA, YUMIKO; HAMANISHI, JUNZO; KONDOH, EIJI; KOSHIYAMA, MASAFUMI; BABA, TSUKASA; MATSUMURA, NORIOMI; MINAMIGUCHI, SACHIKO; KIDO, AKI; KONISHI, IKUO

2016-01-01

Our group previously documented the first, very rare case of primary gastric-type mucinous adenocarcinoma of the uterine corpus. Although this type of endometrial cancer appears to be similar to the gastric-type adenocarcinoma of the uterine cervix, its main symptoms, appearance on magnetic resonance imaging (MRI) and prognosis have not been fully elucidated due to its rarity. We herein describe an additional case of gastric-type mucinous adenocarcinoma of the endometrium and review the relevant literature. The two cases at our institution (Kyoto University Hospital, Kyoto, Japan) involved postmenopausal women with a primary complaint of abnormal genital bleeding. Microscopic examination of the hysterectomy specimens indicated a highly differentiated mucinous adenocarcinoma with a desmoplastic stromal reaction. Immunohistochemistry for HIK1083 and/or MUC6 was positive in both cases, suggesting a gastric phenotype. Both patients were diagnosed at an advanced stage, they relapsed or recurred immediately after adjuvant chemotherapy, and eventually succumbed to the disease. The main symptom of gastric-type mucinous adenocarcinoma of the uterine cervix is watery discharge, whereas abnormal genital bleeding in addition to watery discharge is mainly observed in the mucinous type of endometrial adenocarcinoma. Cystic cavities in the tumor are present on MRI in cases of endometrial origin, and prognosis is very poor due to resistance to chemotherapy. Thus, gastric-type mucinous adenocarcinoma of the uterine endometrium exhibits a clinical behavior that is similar to tumors originating from the uterine cervix, but is associated with distinguishing clinical symptoms. The incidence of gastric-type endometrial adenocarcinoma may be higher than expected. PMID:27123265

White Matter Damage Relates to Oxygen Saturation in Children With Sickle Cell Anemia Without Silent Cerebral Infarcts.

PubMed

Kawadler, Jamie M; Kirkham, Fenella J; Clayden, Jonathan D; Hollocks, Matthew J; Seymour, Emma L; Edey, Rosanna; Telfer, Paul; Robins, Andrew; Wilkey, Olu; Barker, Simon; Cox, Tim C S; Clark, Chris A

2015-07-01

Sickle cell anemia is associated with compromised oxygen-carrying capability of hemoglobin and a high incidence of overt and silent stroke. However, in children with no evidence of cerebral infarction, there are changes in brain morphometry relative to healthy controls, which may be related to chronic anemia and oxygen desaturation. A whole-brain tract-based spatial statistics analysis was carried out in 25 children with sickle cell anemia with no evidence of abnormality on T2-weighted magnetic resonance imaging (13 male, age range: 8-18 years) and 14 age- and race-matched controls (7 male, age range: 10-19 years) to determine the extent of white matter injury. The hypotheses that white matter damage is related to daytime peripheral oxygen saturation and steady-state hemoglobin were tested. Fractional anisotropy was found to be significantly lower in patients in the subcortical white matter (corticospinal tract and cerebellum), whereas mean diffusivity and radial diffusivity were higher in patients in widespread areas. There was a significant negative relationship between radial diffusivity and oxygen saturation (P<0.05) in the anterior corpus callosum and a trend-level negative relationship between radial diffusivity and hemoglobin (P<0.1) in the midbody of the corpus callosum. These data show widespread white matter abnormalities in a sample of asymptomatic children with sickle cell anemia, and provides for the first time direct evidence of a relationship between brain microstructure and markers of disease severity (eg, peripheral oxygen saturation and steady-state hemoglobin). This study suggests that diffusion tensor imaging metrics may serve as a biomarker for future trials of reducing hypoxic exposure. © 2015 American Heart Association, Inc.

Vanishing white matter disease with a novel EIF2B5 mutation: A 10-year follow-up.

PubMed

Bektaş, Gonca; Yeşil, Gözde; Özkan, Melis Ulak; Yıldız, Edibe Pembegül; Uzunhan, Tuğçe Aksu; Çalışkan, Mine

2018-06-19

Vanishing white matter disease is a heterogeneous disorder caused by mutation in one of the five genes encoding subunits of the eukaryotic initiation factor eIF2B. It is a heterogeneous disorder due to phenotypic variation and a clear genotype-phenotype correlation could not be established so far. We describe a novel mutation in the EIF2B5 gene by analyzing the clinical phenotype and the progression of brain lesions for 10 years. A novel mutation in the EIF2B5 gene was detected in the heterozygous state; c.1688G > A (p. Arg563Gln) mutation in exon 12, accompanied by a previously detected c.806G > A (p. Arg269Gln) mutation in exon 6, leading to substitution of arginine for a glutamine. This compound heterozygous mutation was associated with disease onset at early childhood and relatively slow progression of neurological deterioration. In contrast to previous findings indicated the association of c.806G > A mutation and peripheral neuropathy in patients with vanishing white matter disease, electromyography of our case was normal. The corpus callosum inner rim was the affected area at early stages, which may be remarkable for early diagnosis of vanishing white matter disease. Serial follow-up magnetic resonance imaging revealed the white matter signal abnormality, subsequently cystic degeneration and decrease in white matter volume. The novel mutation c.1688G > A in compound heterozygous state leads to intermediate phenotype of the vanishing white matter disease. In the early stages of the disease the signal abnormality in the corpus callosum inner rim might be remarkable. Copyright © 2018 Elsevier B.V. All rights reserved.

Disruption of the Zdhhc9 intellectual disability gene leads to behavioural abnormalities in a mouse model.

PubMed

Kouskou, Marianna; Thomson, David M; Brett, Ros R; Wheeler, Lee; Tate, Rothwelle J; Pratt, Judith A; Chamberlain, Luke H

2018-06-23

Protein S-acylation is a widespread post-translational modification that regulates the trafficking and function of a diverse array of proteins. This modification is catalysed by a family of twenty-three zDHHC enzymes that exhibit both specific and overlapping substrate interactions. Mutations in the gene encoding zDHHC9 cause mild-to-moderate intellectual disability, seizures, speech and language impairment, hypoplasia of the corpus callosum and reduced volume of sub-cortical structures. In this study, we have undertaken behavioural phenotyping, magnetic resonance imaging (MRI) and isolation of S-acylated proteins to investigate the effect of disruption of the Zdhhc9 gene in mice in a C57BL/6 genetic background. Zdhhc9 mutant male mice exhibit a range of abnormalities compared with their wild-type littermates: altered behaviour in the open-field test, elevated plus maze and acoustic startle test that is consistent with a reduced anxiety level; a reduced hang time in the hanging wire test that suggests underlying hypotonia but which may also be linked to reduced anxiety; deficits in the Morris water maze test of hippocampal-dependent spatial learning and memory; and a 36% reduction in corpus callosum volume revealed by MRI. Surprisingly, membrane association and S-acylation of H-Ras was not disrupted in either whole brain or hippocampus of Zdhhc9 mutant mice, suggesting that other substrates of this enzyme are linked to the observed changes. Overall, this study highlights a key role for zDHHC9 in brain development and behaviour, and supports the utility of the Zdhhc9 mutant mouse line to investigate molecular and cellular changes linked to intellectual disability and other deficits in the human population. Copyright © 2018. Published by Elsevier Inc.

The ligation of the male reproductive organs and the role of the spermatic cyst.

PubMed

Kuwahara, M; Frick, J

1975-01-01

The effects of ligation of the vas deferens, the corpus epididymis and the vasa efferentia on spermatozoa and testicular morphology were studied in sexually mature rats. Following the ligation of the vas deferens, headless and immotile spermatozoa were observed on the second day in the vas deferens. Decapitation occured in more than ninty per cent of the spermatozoa on the sixth day and the motility became almost zero. On the contrary, in the epididymis normal spermatozoa were observed for a relatively long period. Even three weeks after the vas ligation, more than ninty per cent of spermatozoa showed normal morphology. Spermatic cyst formation was observed so early as four days following ligation of the vas. By the third week cysts were observed in most rats, either unilaterally or bilaterally. In addition, ligation of the corpus epididymis resulted also in the formation of a spermatic cyst on the proximal site of the ligature. A strong correlation was observed between spermatic cyst formation and the occurrence of morphological changes in the testis, as well as the motility and the normality of spermatozoa. When the spermatic cyst was formed, the testis showed almost normal morphology for a long period as well as spermatozoa in the ductal system. When a spermatic cyst was not formed, degenerative changes took place promptly and abnormal spermatozoa were observed in the ductal system. These observations suggest that the seminiferous tubules may be very sensitivie to the increase in intratubular pressure and in such instances the spermatic cyst acts as a "shock absorber" to prevent the abnormal increase of pressure within the ductal system, especially the seminiferous tubules. In addition, the result suggests further that a need for caution and careful follow-up are necessary in the vasectomized man.

The myelinated fiber loss in the corpus callosum of mouse model of schizophrenia induced by MK-801.

PubMed

Xiu, Yun; Kong, Xiang-ru; Zhang, Lei; Qiu, Xuan; Gao, Yuan; Huang, Chun-xia; Chao, Feng-lei; Wang, San-rong; Tang, Yong

2015-04-01

Previous magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI) investigations have shown that the white matter volume and fractional anisotropy (FA) were decreased in schizophrenia (SZ), which indicated impaired white matter integrity in SZ. However, the mechanism underlying these abnormalities has been less studied. The current study was designed to investigate the possible reasons for white matter abnormalities in the mouse model of SZ induced by NMDA receptor antagonist using the unbiased stereological methods and transmission electron microscope technique. We found that the mice treated with MK-801 demonstrated a series of schizophrenia-like behaviors including hyperlocomotor activity and more anxiety. The myelinated fibers in the corpus callosum (CC) of the mice treated with MK-801 were impaired with splitting lamellae of myelin sheaths and segmental demyelination. The CC volume and the total length of the myelinated fibers in the CC of the mice treated with MK-801 were significantly decreased by 9.4% and 16.8% when compared to those of the mice treated with saline. We further found that the loss of the myelinated fibers length was mainly due to the marked loss of the myelinated nerve fibers with the diameter of 0.4-0.5 μm. These results indicated that the splitting myelin sheaths, demyelination and the loss of myelinated fibers with small diameter might provide one of the structural bases for impaired white matter integrity of CC in the mouse model of SZ. These results might also provide a baseline for further studies searching for the treatment of SZ through targeting white matter. Copyright © 2015 Elsevier Ltd. All rights reserved.

Neuroimaging abnormalities in clade C HIV are independent of Tat genetic diversity.

PubMed

Paul, Robert H; Phillips, Sarah; Hoare, Jacqueline; Laidlaw, David H; Cabeen, Ryan; Olbricht, Gayla R; Su, Yuqing; Stein, Dan J; Engelbrecht, Susan; Seedat, Soraya; Salminen, Lauren E; Baker, Laurie M; Heaps, Jodi; Joska, John

2017-04-01

Controversy remains regarding the neurotoxicity of clade C human immunodeficiency virus (HIV-C). When examined in preclinical studies, a cysteine to serine substitution in the C31 dicysteine motif of the HIV-C Tat protein (C31S) results in less severe brain injury compared to other viral clades. By contrast, patient cohort studies identify significant neuropsychological impairment among HIV-C individuals independent of Tat variability. The present study clarified this discrepancy by examining neuroimaging markers of brain integrity among HIV-C individuals with and without the Tat substitution. Thirty-seven HIV-C individuals with the Tat C31S substitution, 109 HIV-C individuals without the Tat substitution (C31C), and 34 HIV- controls underwent 3T structural magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI). Volumes were determined for the caudate, putamen, thalamus, corpus callosum, total gray matter, and total white matter. DTI metrics included fractional anisotropy (FA), radial diffusivity (RD), and axial diffusivity (AD). Tracts of interest included the anterior thalamic radiation (ATR), cingulum bundle (CING), uncinate fasciculus (UNC), and corpus callosum (CC). HIV+ individuals exhibited smaller volumes in subcortical gray matter, total gray matter and total white matter compared to HIV- controls. HIV+ individuals also exhibited DTI abnormalities across multiple tracts compared to HIV- controls. By contrast, neither volumetric nor diffusion indices differed significantly between the Tat C31S and C31C groups. Tat C31S status is not a sufficient biomarker of HIV-related brain integrity in patient populations. Clinical attention directed at brain health is warranted for all HIV+ individuals, independent of Tat C31S or clade C status.

Carboplatin and Paclitaxel With or Without Cisplatin and Radiation Therapy in Treating Patients With Stage I, Stage II, Stage III, or Stage IVA Endometrial Cancer

ClinicalTrials.gov

2018-01-09

Endometrial Clear Cell Adenocarcinoma; Endometrial Serous Adenocarcinoma; Stage IA Uterine Corpus Cancer; Stage IB Uterine Corpus Cancer; Stage II Uterine Corpus Cancer; Stage IIIA Uterine Corpus Cancer; Stage IIIB Uterine Corpus Cancer; Stage IIIC Uterine Corpus Cancer; Stage IVA Uterine Corpus Cancer

Medroxyprogesterone in Treating Patients With Endometrioid Adenocarcinoma of the Uterine Corpus

ClinicalTrials.gov

2016-03-17

Endometrial Adenocarcinoma; Endometrial Adenosquamous Carcinoma; Endometrial Endometrioid Adenocarcinoma, Variant With Squamous Differentiation; Recurrent Uterine Corpus Carcinoma; Stage I Uterine Corpus Cancer; Stage II Uterine Corpus Cancer; Stage III Uterine Corpus Cancer; Stage IV Uterine Corpus Cancer

Additive effects of two quantitative trait loci that confer Rhopalosiphum maidis (corn leaf aphid) resistance in maize inbred line Mo17

PubMed Central

Betsiashvili, Mariam; Ahern, Kevin R.; Jander, Georg

2015-01-01

Plants show considerable within-species variation in their resistance to insect herbivores. In the case of Zea mays (cultivated maize), Rhopalosiphum maidis (corn leaf aphids) produce approximately twenty times more progeny on inbred line B73 than on inbred line Mo17. Genetic mapping of this difference in maize aphid resistance identified quantitative trait loci (QTL) on chromosomes 4 and 6, with the Mo17 allele reducing aphid reproduction in each case. The chromosome 4 QTL mapping interval includes several genes involved in the biosynthesis of DIMBOA (2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one), a maize defensive metabolite that also is required for callose accumulation in response to aphid feeding. Consistent with the known association of callose with plant defence against aphids, R. maidis reproduction on B73×Mo17 recombinant inbred lines was negatively correlated with both DIMBOA content and callose formation. Further genetic mapping, as well as experiments with near-isogenic lines, confirmed that the Mo17 allele causes increased DIMBOA accumulation relative to the B73 allele. The chromosome 6 aphid resistance QTL functions independently of DIMBOA accumulation and has an effect that is additive to that of the chromosome 4 QTL. Thus, at least two separate defence mechanisms account for the higher level of R. maidis resistance in Mo17 compared with B73. PMID:25249072

Specific membrane lipid composition is important for plasmodesmata function in Arabidopsis.

PubMed

Grison, Magali S; Brocard, Lysiane; Fouillen, Laetitia; Nicolas, William; Wewer, Vera; Dörmann, Peter; Nacir, Houda; Benitez-Alfonso, Yoselin; Claverol, Stéphane; Germain, Véronique; Boutté, Yohann; Mongrand, Sébastien; Bayer, Emmanuelle M

2015-04-01

Plasmodesmata (PD) are nano-sized membrane-lined channels controlling intercellular communication in plants. Although progress has been made in identifying PD proteins, the role played by major membrane constituents, such as the lipids, in defining specialized membrane domains in PD remains unknown. Through a rigorous isolation of "native" PD membrane fractions and comparative mass spectrometry-based analysis, we demonstrate that lipids are laterally segregated along the plasma membrane (PM) at the PD cell-to-cell junction in Arabidopsis thaliana. Remarkably, our results show that PD membranes display enrichment in sterols and sphingolipids with very long chain saturated fatty acids when compared with the bulk of the PM. Intriguingly, this lipid profile is reminiscent of detergent-insoluble membrane microdomains, although our approach is valuably detergent-free. Modulation of the overall sterol composition of young dividing cells reversibly impaired the PD localization of the glycosylphosphatidylinositol-anchored proteins Plasmodesmata Callose Binding 1 and the β-1,3-glucanase PdBG2 and altered callose-mediated PD permeability. Altogether, this study not only provides a comprehensive analysis of the lipid constituents of PD but also identifies a role for sterols in modulating cell-to-cell connectivity, possibly by establishing and maintaining the positional specificity of callose-modifying glycosylphosphatidylinositol proteins at PD. Our work emphasizes the importance of lipids in defining PD membranes. © 2015 American Society of Plant Biologists. All rights reserved.

Specific Membrane Lipid Composition Is Important for Plasmodesmata Function in Arabidopsis

PubMed Central

Grison, Magali S.; Brocard, Lysiane; Fouillen, Laetitia; Nicolas, William; Wewer, Vera; Dörmann, Peter; Nacir, Houda; Benitez-Alfonso, Yoselin; Claverol, Stéphane; Germain, Véronique; Boutté, Yohann; Mongrand, Sébastien; Bayer, Emmanuelle M.

2015-01-01

Plasmodesmata (PD) are nano-sized membrane-lined channels controlling intercellular communication in plants. Although progress has been made in identifying PD proteins, the role played by major membrane constituents, such as the lipids, in defining specialized membrane domains in PD remains unknown. Through a rigorous isolation of “native” PD membrane fractions and comparative mass spectrometry-based analysis, we demonstrate that lipids are laterally segregated along the plasma membrane (PM) at the PD cell-to-cell junction in Arabidopsis thaliana. Remarkably, our results show that PD membranes display enrichment in sterols and sphingolipids with very long chain saturated fatty acids when compared with the bulk of the PM. Intriguingly, this lipid profile is reminiscent of detergent-insoluble membrane microdomains, although our approach is valuably detergent-free. Modulation of the overall sterol composition of young dividing cells reversibly impaired the PD localization of the glycosylphosphatidylinositol-anchored proteins Plasmodesmata Callose Binding 1 and the β-1,3-glucanase PdBG2 and altered callose-mediated PD permeability. Altogether, this study not only provides a comprehensive analysis of the lipid constituents of PD but also identifies a role for sterols in modulating cell-to-cell connectivity, possibly by establishing and maintaining the positional specificity of callose-modifying glycosylphosphatidylinositol proteins at PD. Our work emphasizes the importance of lipids in defining PD membranes. PMID:25818623

Novelties of the flowering plant pollen tube underlie diversification of a key life history stage.

PubMed

Williams, Joseph H

2008-08-12

The origin and rapid diversification of flowering plants has puzzled evolutionary biologists, dating back to Charles Darwin. Since that time a number of key life history and morphological traits have been proposed as developmental correlates of the extraordinary diversity and ecological success of angiosperms. Here, I identify several innovations that were fundamental to the evolutionary lability of angiosperm reproduction, and hence to their diversification. In gymnosperms pollen reception must be near the egg largely because sperm swim or are transported by pollen tubes that grow at very slow rates (< approximately 20 microm/h). In contrast, pollen tube growth rates of taxa in ancient angiosperm lineages (Amborella, Nuphar, and Austrobaileya) range from approximately 80 to 600 microm/h. Comparative analyses point to accelerated pollen tube growth rate as a critical innovation that preceded the origin of the true closed carpel, long styles, multiseeded ovaries, and, in monocots and eudicots, much faster pollen tube growth rates. Ancient angiosperm pollen tubes all have callosic walls and callose plugs (in contrast, no gymnosperms have these features). The early association of the callose-walled growth pattern with accelerated pollen tube growth rate underlies a striking repeated pattern of faster and longer-distance pollen tube growth often within solid pathways in phylogenetically derived angiosperms. Pollen tube innovations are a key component of the spectacular diversification of carpel (flower and fruit) form and reproductive cycles in flowering plants.

β-1,3-Glucans are components of brown seaweed (Phaeophyceae) cell walls.

PubMed

Raimundo, Sandra Cristina; Pattathil, Sivakumar; Eberhard, Stefan; Hahn, Michael G; Popper, Zoë A

2017-03-01

LAMP is a cell wall-directed monoclonal antibody (mAb) that recognizes a β-(1,3)-glucan epitope. It has primarily been used in the immunolocalization of callose in vascular plant cell wall research. It was generated against a brown seaweed storage polysaccharide, laminarin, although it has not often been applied in algal research. We conducted in vitro (glycome profiling of cell wall extracts) and in situ (immunolabeling of sections) studies on the brown seaweeds Fucus vesiculosus (Fucales) and Laminaria digitata (Laminariales). Although glycome profiling did not give a positive signal with the LAMP mAb, this antibody clearly detected the presence of the β-(1,3)-glucan in situ, showing that this epitope is a constituent of these brown algal cell walls. In F. vesiculosus, the β-(1,3)-glucan epitope was present throughout the cell walls in all thallus parts; in L. digitata, the epitope was restricted to the sieve plates of the conductive elements. The sieve plate walls also stained with aniline blue, a fluorochrome used as a probe for callose. Enzymatic digestion with an endo-β-(1,3)-glucanase removed the ability of the LAMP mAb to label the cell walls. Thus, β-(1,3)-glucans are structural polysaccharides of F. vesiculosus cell walls and are integral components of the sieve plates in these brown seaweeds, reminiscent of plant callose.

Congenital Dandy Walker malformation associated with first trimester warfarin: a case report and literature review.

PubMed

Kaplan, L C

1985-12-01

While the warfarin embryopathy is well defined, central nervous system abnormalities associated with gestational warfarin exposure require further definition. Based on the timing of warfarin exposure in humans, it has been proposed that second- and third-trimester exposure predisposes to CNS abnormalities while first-trimester exposure more typically is associated with the warfarin embryopathy. A case is presented of a liveborn male with Dandy Walker malformation, agenesis of the corpus callosum, and Peter anomaly of the right eye who was exposed to warfarin between the 8th and 12th weeks of gestation who had none of the stigmata of the warfarin embryopathy. His is the first known case of exposure confined to the first trimester, and the fifth case of Dandy Walker malformation among a total of 15 CNS cases associated with this drug. This case offers evidence that Dandy Walker malformation may represent a distinct complication of in utero first-trimester exposure, and consideration of these particular abnormalities with exposure limited to a period prior to the known appearance of vitamin K-dependent clotting factors suggests that warfarin has a direct teratogenic effect on central nervous system morphogenesis.

Disorganization of white matter architecture in major depressive disorder: a meta-analysis of diffusion tensor imaging with tract-based spatial statistics.

PubMed

Chen, Guangxiang; Hu, Xinyu; Li, Lei; Huang, Xiaoqi; Lui, Su; Kuang, Weihong; Ai, Hua; Bi, Feng; Gu, Zhongwei; Gong, Qiyong

2016-02-24

White matter (WM) abnormalities have long been suspected in major depressive disorder (MDD). Tract-based spatial statistics (TBSS) studies have detected abnormalities in fractional anisotropy (FA) in MDD, but the available evidence has been inconsistent. We performed a quantitative meta-analysis of TBSS studies contrasting MDD patients with healthy control subjects (HCS). A total of 17 studies with 18 datasets that included 641 MDD patients and 581 HCS were identified. Anisotropic effect size-signed differential mapping (AES-SDM) meta-analysis was performed to assess FA alterations in MDD patients compared to HCS. FA reductions were identified in the genu of the corpus callosum (CC) extending to the body of the CC and left anterior limb of the internal capsule (ALIC) in MDD patients relative to HCS. Descriptive analysis of quartiles, sensitivity analysis and subgroup analysis further confirmed these findings. Meta-regression analysis revealed that individuals with more severe MDD were significantly more likely to have FA reductions in the genu of the CC. This study provides a thorough profile of WM abnormalities in MDD and evidence that interhemispheric connections and frontal-striatal-thalamic pathways are the most convergent circuits affected in MDD.

Doxorubicin Hydrochloride, Cisplatin, and Paclitaxel or Carboplatin and Paclitaxel in Treating Patients With Stage III-IV or Recurrent Endometrial Cancer

ClinicalTrials.gov

2018-03-23

Recurrent Uterine Corpus Carcinoma; Stage IIIA Uterine Corpus Cancer; Stage IIIB Uterine Corpus Cancer; Stage IIIC Uterine Corpus Cancer; Stage IVA Uterine Corpus Cancer; Stage IVB Uterine Corpus Cancer

Magnetic resonance imaging (MRI) evaluation of developmental delay in pediatric patients.

PubMed

Ali, Althaf S; Syed, Naziya P; Murthy, G S N; Nori, Madhavi; Abkari, Anand; Pooja, B K; Venkateswarlu, J

2015-01-01

Developmental delay is defined as significant delay in one or more developmental domains. Magnetic Resonance Imaging (MRI) is the best modality to investigate such patients. Evaluation of a child with developmental delay is important not only because it allows early diagnosis and treatment but also helpful for parental counseling regarding the outcome of their child and to identify any possible risk of recurrence in the siblings. Thus this study was undertaken to evaluate the developmental delay in Indian children which will help the clinicians in providing an estimation of the child's ultimate developmental potential and organize specific treatment requirement and also relieve parental apprehension. To study the prevalence of normal and abnormal MRI in pediatric patients presenting with developmental delay and further categorize the abnormal MRI based on its morphological features. It is a prospective, observational & descriptive study of MRI Brain in 81 paediatric patients (46 Males and 35 Females), aged between three months to 12 years; presenting with developmental delay in Deccan College of Medical Sciences, Hyderabad; over a period of three years (Sept 2011 to Sept 2014). MRI brain was done on 1.5T Siemens Magnetom Essenza & 0.35T Magnetom C with appropriate sequences and planes after making the child sleep/sedated/ anesthetized. Various anatomical structures like Ventricles, Corpus callosum, etc were systematically assessed. The MRI findings were divided into various aetiological subgroups. Normal MRI findings were seen in 32% cases and 68% had abnormal findings of which the proportion of Traumatic/ Neurovascular Diseases, Congenital & Developmental, Metabolic and Degenerative, neoplastic and non specific were 31%, 17%, 10%, 2.5% and 7.5% respectively. The ventricles and white matter mainly the corpus callosum were the most commonly affected anatomical structures. The diagnostic yield was found to be 68% and higher yield was seen in patients presenting with developmental delay plus. The clinical diagnosis of developmental delay should not be the end point, but rather a springboard for an effective search for causal factors. MRI is the best investigation with a high yield in such patients.

Magnetic Resonance Imaging (MRI) Evaluation of Developmental Delay in Pediatric Patients

PubMed Central

Syed, Naziya P.; Murthy, G.S.N.; Nori, Madhavi; Abkari, Anand; Pooja, B.K.; Venkateswarlu, J.

2015-01-01

Introduction: Developmental delay is defined as significant delay in one or more developmental domains. Magnetic Resonance Imaging (MRI) is the best modality to investigate such patients. Evaluation of a child with developmental delay is important not only because it allows early diagnosis and treatment but also helpful for parental counseling regarding the outcome of their child and to identify any possible risk of recurrence in the siblings. Thus this study was undertaken to evaluate the developmental delay in Indian children which will help the clinicians in providing an estimation of the child’s ultimate developmental potential and organize specific treatment requirement and also relieve parental apprehension. Aims and Objectives: To study the prevalence of normal and abnormal MRI in pediatric patients presenting with developmental delay and further categorize the abnormal MRI based on its morphological features. Materials and Methods: It is a prospective, observational & descriptive study of MRI Brain in 81 paediatric patients (46 Males and 35 Females), aged between three months to 12 years; presenting with developmental delay in Deccan College of Medical Sciences, Hyderabad; over a period of three years (Sept 2011 to Sept 2014). MRI brain was done on 1.5T Siemens Magnetom Essenza & 0.35T Magnetom C with appropriate sequences and planes after making the child sleep/sedated/ anesthetized. Various anatomical structures like Ventricles, Corpus callosum, etc were systematically assessed. The MRI findings were divided into various aetiological subgroups. Results: Normal MRI findings were seen in 32% cases and 68% had abnormal findings of which the proportion of Traumatic/ Neurovascular Diseases, Congenital & Developmental, Metabolic and Degenerative, neoplastic and non specific were 31%, 17%, 10%, 2.5% and 7.5% respectively. The ventricles and white matter mainly the corpus callosum were the most commonly affected anatomical structures. The diagnostic yield was found to be 68% and higher yield was seen in patients presenting with developmental delay plus. Conclusion: The clinical diagnosis of developmental delay should not be the end point, but rather a springboard for an effective search for causal factors. MRI is the best investigation with a high yield in such patients. PMID:25738057

Short Course Vaginal Cuff Brachytherapy in Treating Patients With Stage I-II Endometrial Cancer

ClinicalTrials.gov

2018-04-17

Endometrial Clear Cell Adenocarcinoma; Endometrial Endometrioid Adenocarcinoma; Endometrial Serous Adenocarcinoma; Stage I Uterine Corpus Cancer; Stage IA Uterine Corpus Cancer; Stage IB Uterine Corpus Cancer; Stage II Uterine Corpus Cancer; Uterine Corpus Carcinosarcoma; Uterine Corpus Sarcoma

Paclitaxel and Carboplatin With or Without Metformin Hydrochloride in Treating Patients With Stage III, IV, or Recurrent Endometrial Cancer

ClinicalTrials.gov

2018-03-07

Endometrial Adenocarcinoma; Endometrial Clear Cell Adenocarcinoma; Endometrial Serous Adenocarcinoma; Endometrial Undifferentiated Carcinoma; Recurrent Uterine Corpus Carcinoma; Stage III Uterine Corpus Cancer AJCC v7; Stage IIIA Uterine Corpus Cancer AJCC v7; Stage IIIB Uterine Corpus Cancer AJCC v7; Stage IIIC Uterine Corpus Cancer AJCC v7; Stage IV Uterine Corpus Cancer AJCC v7; Stage IVA Uterine Corpus Cancer AJCC v7; Stage IVB Uterine Corpus Cancer AJCC v7

Paclitaxel and Intraperitoneal Carboplatin Followed by Radiation Therapy in Treating Patients With Stage IIIC-IV Uterine Cancer

ClinicalTrials.gov

2015-02-10

Endometrial Serous Adenocarcinoma; Stage IIIA Uterine Corpus Cancer; Stage IIIB Uterine Corpus Cancer; Stage IIIC1 Uterine Corpus Cancer; Stage IIIC2 Uterine Corpus Cancer; Stage IVA Uterine Corpus Cancer; Stage IVB Uterine Corpus Cancer

Liver X receptor β is essential for the differentiation of radial glial cells to oligodendrocytes in the dorsal cortex.

PubMed

Xu, P; Xu, H; Tang, X; Xu, L; Wang, Y; Guo, L; Yang, Z; Xing, Y; Wu, Y; Warner, M; Gustafsson, J-A; Fan, X

2014-08-01

Several psychiatric disorders are associated with aberrant white matter development, suggesting oligodendrocyte and myelin dysfunction in these diseases. There are indications that radial glial cells (RGCs) are involved in initiating myelination, and may contribute to the production of oligodendrocyte progenitor cells (OPCs) in the dorsal cortex. Liver X receptors (LXRs) are involved in maintaining normal myelin in the central nervous system (CNS), however, their function in oligodendrogenesis and myelination is not well understood. Here, we demonstrate that loss of LXRβ function leads to abnormality in locomotor activity and exploratory behavior, signs of anxiety and hypomyelination in the corpus callosum and optic nerve, providing in vivo evidence that LXRβ deletion delays both oligodendrocyte differentiation and maturation. Remarkably, along the germinal ventricular zone-subventricular zone and corpus callosum there is reduced OPC production from RGCs in LXRβ(-/-) mice. Conversely, in cultured RGC an LXR agonist led to increased differentiation into OPCs. Collectively, these results suggest that LXRβ, by driving RGCs to become OPCs in the dorsal cortex, is critical for white matter development and CNS myelination, and point to the involvement of LXRβ in psychiatric disorders.

Reduced striatal dopamine transporters in people with internet addiction disorder.

PubMed

Hou, Haifeng; Jia, Shaowe; Hu, Shu; Fan, Rong; Sun, Wen; Sun, Taotao; Zhang, Hong

2012-01-01

In recent years, internet addiction disorder (IAD) has become more prevalent worldwide and the recognition of its devastating impact on the users and society has rapidly increased. However, the neurobiological mechanism of IAD has not bee fully expressed. The present study was designed to determine if the striatal dopamine transporter (DAT) levels measured by (99m)Tc-TRODAT-1 single photon emission computed tomography (SPECT) brain scans were altered in individuals with IAD. SPECT brain scans were acquired on 5 male IAD subjects and 9 healthy age-matched controls. The volume (V) and weight (W) of bilateral corpus striatum as well as the (99m)Tc-TRODAT-1 uptake ratio of corpus striatum/the whole brain (Ra) were calculated using mathematical models. It was displayed that DAT expression level of striatum was significantly decreased and the V, W, and Ra were greatly reduced in the individuals with IAD compared to controls. Taken together, these results suggest that IAD may cause serious damages to the brain and the neuroimaging findings further illustrate IAD is associated with dysfunctions in the dopaminergic brain systems. Our findings also support the claim that IAD may share similar neurobiological abnormalities with other addictive disorders.

Dasatinib, Paclitaxel, and Carboplatin in Treating Patients With Stage III-IV or Recurrent Endometrial Cancer

ClinicalTrials.gov

2018-04-04

Endometrial Adenocarcinoma; Endometrial Clear Cell Adenocarcinoma; Endometrial Mucinous Adenocarcinoma; Endometrial Serous Adenocarcinoma; Endometrial Squamous Cell Carcinoma; Endometrial Transitional Cell Carcinoma; Endometrial Undifferentiated Carcinoma; Endometrioid Adenocarcinoma; Recurrent Uterine Corpus Carcinoma; Stage III Uterine Corpus Cancer AJCC v7; Stage IIIA Uterine Corpus Cancer AJCC v7; Stage IIIB Uterine Corpus Cancer AJCC v7; Stage IIIC Uterine Corpus Cancer AJCC v7; Stage IV Uterine Corpus Cancer AJCC v7; Stage IVA Uterine Corpus Cancer AJCC v7; Stage IVB Uterine Corpus Cancer AJCC v7

Intensity-Modulated Radiation Therapy, Cisplatin, and Bevacizumab Followed by Carboplatin and Paclitaxel in Treating Patients Who Have Undergone Surgery for Endometrial Cancer

ClinicalTrials.gov

2018-02-15

Endometrial Adenocarcinoma; Endometrial Adenosquamous Carcinoma; Endometrial Clear Cell Adenocarcinoma; Endometrial Serous Adenocarcinoma; Stage IA Uterine Corpus Cancer AJCC v7; Stage IB Uterine Corpus Cancer AJCC v7; Stage II Uterine Corpus Cancer AJCC v7; Stage IIIA Uterine Corpus Cancer AJCC v7; Stage IIIB Uterine Corpus Cancer AJCC v7; Stage IIIC Uterine Corpus Cancer AJCC v7; Stage IVA Uterine Corpus Cancer AJCC v7; Stage IVB Uterine Corpus Cancer AJCC v7

Lissencephaly with brainstem and cerebellar hypoplasia and congenital cataracts.

PubMed

Abumansour, Iman S; Wrogemann, Jens; Chudley, Albert E; Chodirker, Bernard N; Salman, Michael S

2014-06-01

Classical lissencephaly may be associated with cerebellar hypoplasia and when significant cerebellar abnormalities occur, defects in proteins encoded by TUBA1A, RELN, and very-low-density lipoprotein receptor (VLDLR) genes have been reported. We present a neonate with a severe neurologic phenotype associated with hypotonia, oropharyngeal incoordination that required a gastric tube for feeding, intractable epilepsy, and congenital cataracts. Her brain magnetic resonance imaging (MRI) showed classical lissencephaly, ventriculomegaly, absent corpus callosum, globular and vertical hippocampi, and severe cerebellar and brainstem hypoplasia. She died at 6 weeks of age. No specific molecular diagnosis was made. This likely represents a previously undescribed genetic lissencephaly syndrome. © The Author(s) 2013.

Human TUBB3 mutations perturb microtubule dynamics, kinesin interactions, and axon guidance

PubMed Central

Tischfield, Max A.; Baris, Hagit N.; Wu, Chen; Rudolph, Guenther; Van Maldergem, Lionel; He, Wei; Chan, Wai-Man; Andrews, Caroline; Demer, Joseph L.; Robertson, Richard L.; Mackey, David A.; Ruddle, Jonathan B.; Bird, Thomas D.; Gottlob, Irene; Pieh, Christina; Traboulsi, Elias I.; Pomeroy, Scott L.; Hunter, David G.; Soul, Janet S.; Newlin, Anna; Sabol, Louise J.; Doherty, Edward J.; de Uzcátegui, Clara E.; de Uzcátegui, Nicolas; Collins, Mary Louise Z.; Sener, Emin C.; Wabbels, Bettina; Hellebrand, Heide; Meitinger, Thomas; de Berardinis, Teresa; Magli, Adriano; Schiavi, Costantino; Pastore-Trossello, Marco; Koc, Feray; Wong, Agnes M.; Levin, Alex V.; Geraghty, Michael T.; Descartes, Maria; Flaherty, Maree; Jamieson, Robyn V.; Møller, H. U.; Meuthen, Ingo; Callen, David F.; Kerwin, Janet; Lindsay, Susan; Meindl, Alfons; Gupta, Mohan L.; Pellman, David; Engle, Elizabeth C.

2011-01-01

We report that eight heterozygous missense mutations in TUBB3, encoding the neuron-specific β-tubulin isotype III, result in a spectrum of human nervous system disorders we now call the TUBB3 syndromes. Each mutation causes the ocular motility disorder CFEOM3, whereas some also result in intellectual and behavioral impairments, facial paralysis, and/or later-onset axonal sensorimotor polyneuropathy. Neuroimaging reveals a spectrum of abnormalities including hypoplasia of oculomotor nerves, and dysgenesis of the corpus callosum, anterior commissure, and corticospinal tracts. A knock-in disease mouse model reveals axon guidance defects without evidence of cortical cell migration abnormalities. We show the disease-associated mutations can impair tubulin heterodimer formation in vitro, although folded mutant heterodimers can still polymerize into microtubules. Modeling each mutation in yeast tubulin demonstrates that all alter dynamic instability whereas a subset disrupts the interaction of microtubules with kinesin motors. These findings demonstrate normal TUBB3 is required for axon guidance and maintenance in mammals. PMID:20074521

Neonatal brain structure on MRI and diffusion tensor imaging, sex, and neurodevelopment in very-low-birthweight preterm children.

PubMed

Rose, Jessica; Butler, Erin E; Lamont, Lauren E; Barnes, Patrick D; Atlas, Scott W; Stevenson, David K

2009-07-01

The neurological basis of an increased incidence of cerebral palsy (CP) in preterm males is unknown. This study examined neonatal brain structure on magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI) at term-equivalent age, sex, and neurodevelopment at 1 year 6 months on the basis of the Amiel-Tison neurological examination, Gross Motor Function Classification System, and Bayley Scales of Infant Development in 78 very-low-birthweight preterm children (41 males, 37 females; mean gestational age 27.6 wks, SD 2.5; mean birthweight 1021 g, SD 339). Brain abnormalities on MRI and DTI were not different between males and females except in the splenium of the corpus callosum, where males had lower DTI fractional anisotropy (p=0.025) and a higher apparent diffusion coefficient (p=0.013), indicating delayed splenium development. In the 26 infants who were at higher risk on the basis of DTI, males had more abnormalities on MRI (p=0.034) and had lower fractional anisotropy and a higher apparent diffusion coefficient in the splenium (p=0.049; p=0.025) and right posterior limb of the internal capsule (PLIC; p=0.003; p=0.033). Abnormal neurodevelopment was more common in males (n=9) than in females (n=2; p=0.036). Children with abnormal neurodevelopment had more abnormalities on MRI (p=0.014) and reduced splenium and right PLIC fractional anisotropy (p=0.001; p=0.035). In children with abnormal neurodevelopment, right PLIC fractional anisotropy was lower than left (p=0.035), whereas in those with normal neurodevelopment right PLIC fractional anisotropy was higher than left (p=0.001). Right PLIC fractional anisotropy correlated to neurodevelopment (rho=0.371, p=0.002). Logistic regression predicted neurodevelopment with 94% accuracy; only right PLIC fractional anisotropy was a significant logistic coefficient. Results indicate that the higher incidence of abnormal neurodevelopment in preterm males relates to greater incidence and severity of brain abnormalities, including reduced PLIC and splenium development.

Large national series of patients with Xq28 duplication involving MECP2: Delineation of brain MRI abnormalities in 30 affected patients.

PubMed

El Chehadeh, Salima; Faivre, Laurence; Mosca-Boidron, Anne-Laure; Malan, Valérie; Amiel, Jeanne; Nizon, Mathilde; Touraine, Renaud; Prieur, Fabienne; Pasquier, Laurent; Callier, Patrick; Lefebvre, Mathilde; Marle, Nathalie; Dubourg, Christèle; Julia, Sophie; Sarret, Catherine; Francannet, Christine; Laffargue, Fanny; Boespflug-Tanguy, Odile; David, Albert; Isidor, Bertrand; Le Caignec, Cédric; Vigneron, Jacqueline; Leheup, Bruno; Lambert, Laetitia; Philippe, Christophe; Cuisset, Jean-Marie; Andrieux, Joris; Plessis, Ghislaine; Toutain, Annick; Goldenberg, Alice; Cormier-Daire, Valérie; Rio, Marlène; Bonnefont, Jean-Paul; Thevenon, Julien; Echenne, Bernard; Journel, Hubert; Afenjar, Alexandra; Burglen, Lydie; Bienvenu, Thierry; Addor, Marie-Claude; Lebon, Sébastien; Martinet, Danièle; Baumann, Clarisse; Perrin, Laurence; Drunat, Séverine; Jouk, Pierre-Simon; Devillard, Françoise; Coutton, Charles; Lacombe, Didier; Delrue, Marie-Ange; Philip, Nicole; Moncla, Anne; Badens, Catherine; Perreton, Nathalie; Masurel, Alice; Thauvin-Robinet, Christel; Des Portes, Vincent; Guibaud, Laurent

2016-01-01

Xq28 duplications encompassing MECP2 have been described in male patients with a severe neurodevelopmental disorder associated with hypotonia and spasticity, severe learning disability, stereotyped movements, and recurrent pulmonary infections. We report on standardized brain magnetic resonance imaging (MRI) data of 30 affected patients carrying an Xq28 duplication involving MECP2 of various sizes (228 kb to 11.7 Mb). The aim of this study was to seek recurrent malformations and attempt to determine whether variations in imaging features could be explained by differences in the size of the duplications. We showed that 93% of patients had brain MRI abnormalities such as corpus callosum abnormalities (n = 20), reduced volume of the white matter (WM) (n = 12), ventricular dilatation (n = 9), abnormal increased hyperintensities on T2-weighted images involving posterior periventricular WM (n = 6), and vermis hypoplasia (n = 5). The occipitofrontal circumference varied considerably between >+2SD in five patients and <-2SD in four patients. Among the nine patients with dilatation of the lateral ventricles, six had a duplication involving L1CAM. The only patient harboring bilateral posterior subependymal nodular heterotopia also carried an FLNA gene duplication. We could not demonstrate a correlation between periventricular WM hyperintensities/delayed myelination and duplication of the IKBKG gene. We thus conclude that patients with an Xq28 duplication involving MECP2 share some similar but non-specific brain abnormalities. These imaging features, therefore, could not constitute a diagnostic clue. The genotype-phenotype correlation failed to demonstrate a relationship between the presence of nodular heterotopia, ventricular dilatation, WM abnormalities, and the presence of FLNA, L1CAM, or IKBKG, respectively, in the duplicated segment. © 2015 Wiley Periodicals, Inc.

MRI as a tool to study brain structure from mouse models for mental retardation

NASA Astrophysics Data System (ADS)

Verhoye, Marleen; Sijbers, Jan; Kooy, R. F.; Reyniers, E.; Fransen, E.; Oostra, B. A.; Willems, Peter; Van der Linden, Anne-Marie

1998-07-01

Nowadays, transgenic mice are a common tool to study brain abnormalities in neurological disorders. These studies usually rely on neuropathological examinations, which have a number of drawbacks, including the risk of artefacts introduced by fixation and dehydration procedures. Here we present 3D Fast Spin Echo Magnetic Resonance Imaging (MRI) in combination with 2D and 3D segmentation techniques as a powerful tool to study brain anatomy. We set up MRI of the brain in mouse models for the fragile X syndrome (FMR1 knockout) and Corpus callosum hypoplasia, mental Retardation, Adducted thumbs, Spastic paraplegia and Hydrocephalus (CRASH) syndrome (L1CAM knockout). Our major goal was to determine qualitative and quantitative differences in specific brain structures. MRI of the brain of fragile X and CRASH patients has revealed alterations in the size of specific brain structures, including the cerebellar vermis and the ventricular system. In the present MRI study of the brain from fragile X knockout mice, we have measured the size of the brain, cerebellum and 4th ventricle, which were reported as abnormal in human fragile X patients, but found no evidence for altered brain regions in the mouse model. In CRASH syndrome, the most specific brain abnormalities are vermis hypoplasia and abnormalities of the ventricular system with some degree of hydrocephalus. With the MRI study of L1CAM knockout mice we found vermis hypoplasia, abnormalities of the ventricular system including dilatation of the lateral and the 4th ventricles. These subtle abnormalities were not detected upon standard neuropathological examination. Here we proved that this sensitive MRI technique allows to measure small differences which can not always be detected by means of pathology.

Paclitaxel, Carboplatin, and Bevacizumab or Paclitaxel, Carboplatin, and Temsirolimus or Ixabepilone, Carboplatin, and Bevacizumab in Treating Patients With Stage III, Stage IV, or Recurrent Endometrial Cancer

ClinicalTrials.gov

2018-01-29

Endometrial Adenocarcinoma; Endometrial Adenosquamous Carcinoma; Endometrial Clear Cell Adenocarcinoma; Endometrial Serous Adenocarcinoma; Recurrent Uterine Corpus Carcinoma; Stage IIIA Uterine Corpus Cancer; Stage IIIB Uterine Corpus Cancer; Stage IIIC Uterine Corpus Cancer; Stage IVA Uterine Corpus Cancer; Stage IVB Uterine Corpus Cancer

76 FR 18395 - Safety Zone; Naval Air Station Corpus Christi Air Show, Oso Bay, Corpus Christi, TX

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-04

...-AA00 Safety Zone; Naval Air Station Corpus Christi Air Show, Oso Bay, Corpus Christi, TX AGENCY: Coast... zone on the navigable waters of Oso Bay in Corpus Christi, Texas in support of the 2011 Naval Air Station Corpus Christi Air Show. This temporary safety zone is necessary to provide for the safety of...

Structural abnormalities of corpus callosum and cortical axonal tracts accompanied by decreased anxiety-like behavior and lowered sociability in spock3- mutant mice.

PubMed

Yamamoto, Ayako; Uchiyama, Koji; Nara, Tomoka; Nishimura, Naomichi; Hayasaka, Michiko; Hanaoka, Kazunori; Yamamoto, Tatsuro

2014-01-01

Spock3/Testican-3 is a nervous system-expressed heparan sulfate proteoglycan belonging to a subgroup of the BM-40/SPARC/osteonectin family, the role of which in brain development is unclear. Because Spock1, a member of the Spock family, inhibits their attachment to substrates and the neurite outgrowth of cultured neuronal cells, Spock3 is also thought to be similarly involved in the neuronal development. In the present study, we established a Spock3-mutant mouse harboring a deletion extending from the presumptive upstream regulatory region to exon 4 of the Spock3 locus and performed histological and behavioral studies on these mutant mice. In wild-type (WT) mice, all Spock members were clearly expressed during brain development. In adults, intense Spock1 and Spock2 expressions were observed throughout the entire brain; whereas, Spock3 expression was no longer visible except in the thalamic nuclei. Thus, Spock3 expression is mostly confined to the developmental stage of the brain. In adult mutant mice, the cells of all cortical layers were swollen. The corpus callosum was narrowed around the central region along the rostral-caudal axis and many small spaces were observed without myelin sheaths throughout the entire corpus callosum. In addition, the cortical input and output fibers did not form into thick bundled fibers as well as the WT counterparts did. Moreover, a subpopulation of corticospinal axonal fibers penetrated into the dorsal striatum with moderately altered orientations. Consistent with these modifications of brain structures, the mutant mice exhibited decreased anxiety-like behavior and lowered sociability. Together, these results demonstrate that Spock3 plays an important role in the formation or maintenance of major neuronal structures in the brain. © 2014 S. Karger AG, Basel.

White Matter Abnormalities Track Disease Progression in PSEN1 Autosomal Dominant Alzheimer's Disease.

PubMed

Sánchez-Valle, Raquel; Monté, Gemma C; Sala-Llonch, Roser; Bosch, Beatriz; Fortea, Juan; Lladó, Albert; Antonell, Anna; Balasa, Mircea; Bargalló, Nuria; Molinuevo, José Luis

2016-01-01

PSEN1 mutations are the most frequent cause of autosomal dominant Alzheimer's disease (ADAD), and show nearly full penetrance. There is presently increasing interest in the study of biomarkers that track disease progression in order to test therapeutic interventions in ADAD. We used white mater (WM) volumetric characteristics and diffusion tensor imaging (DTI) metrics to investigate correlations with the normalized time to expected symptoms onset (relative age ratio) and group differences in a cohort of 36 subjects from PSEN1 ADAD families: 22 mutation carriers, 10 symptomatic (SMC) and 12 asymptomatic (AMC), and 14 non-carriers (NC). Subjects underwent a 3T MRI. WM morphometric data and DTI metrics were analyzed. We found that PSEN1 MC showed significant negative correlation between fractional anisotropy (FA) and the relative age ratio in the genus and body of corpus callosum and corona radiate (p <  0.05 Family-wise error correction (FWE) at cluster level) and positive correlation with mean diffusivity (MD), axial diffusivity (AxD), and radial diffusivity (RD) in the splenium of corpus callosum. SMC presented WM volume loss, reduced FA and increased MD, AxD, and RD in the anterior and posterior corona radiate, corpus callosum (p <  0.05 FWE) compared with NC. No significant differences were observed between AMC and NC in WM volume or DTI measures. These findings suggest that the integrity of the WM deteriorates linearly in PSEN1 ADAD from the early phases of the disease; thus DTI metrics might be useful to monitor the disease progression. However, the lack of significant alterations at the preclinical stages suggests that these indexes might not be good candidates for early markers of the disease.

Effects of luteectomy in early pregnancy on the maintenance of gestation and plasma progesterone concentrations in the viviparous temperate lizard Barisia imbricata imbricata

PubMed Central

2010-01-01

Background Several studies have shown that the corpus luteum is the principal source of progesterone during the gravidity period in reptiles; however, its participation in the maintenance of gestation in the viviparous squamata is in dispute. The effects of ovariectomy or luteectomy vary according to the species and the time at which the procedure is performed. In this paper, we describe the effects of luteectomy during early pregnancy on the maintenance of gestation and progesterone concentrations in the temperate Mexican viviparous lizard Barisia imbricata imbricata. Methods Twenty-four lizards were subjected to three different treatments: luteectomy, sham luteectomy or non-surgical treatment, and blood samples were obtained before and after surgical treatment at different stages of gestation to determine the effects of luteectomy on the maintenance of gestation and progesterone concentrations. Results Spontaneous abortion was not observed in any of the females. However, luteectomy provoked abnormal parturition and a significant reduction in the number of young born alive. Parturition was normal in untreated females as well as those submitted to sham luteectomy. The surgical treatment also caused a significant reduction in progesterone concentrations in luteectomised females during early and middle gestation. However, no significant differences in hormone concentrations were observed among the three groups during late gestation or immediately post-parturition. Conclusions Our observations indicate that the presence of the corpus luteum is not necesary for the maintenance of gestation, but that it does participate in parturition control. Moreover, the corpus luteum of the viviparous lizard B. i. imbricata produces progesterone, at least during the first half of pregnancy, and that an extra-ovarian source of progesterone must maintain gestation in the absence of luteal tissue. PMID:20184772

Identification of histone modifications in biomedical text for supporting epigenomic research

PubMed Central

Kolářik, Corinna; Klinger, Roman; Hofmann-Apitius, Martin

2009-01-01

Background Posttranslational modifications of histones influence the structure of chromatine and in such a way take part in the regulation of gene expression. Certain histone modification patterns, distributed over the genome, are connected to cell as well as tissue differentiation and to the adaption of organisms to their environment. Abnormal changes instead influence the development of disease states like cancer. The regulation mechanisms for modifying histones and its functionalities are the subject of epigenomics investigation and are still not completely understood. Text provides a rich resource of knowledge on epigenomics and modifications of histones in particular. It contains information about experimental studies, the conditions used, and results. To our knowledge, no approach has been published so far for identifying histone modifications in text. Results We have developed an approach for identifying histone modifications in biomedical literature with Conditional Random Fields (CRF) and for resolving the recognized histone modification term variants by term standardization. For the term identification F1 measures of 0.84 by 10-fold cross-validation on the training corpus and 0.81 on an independent test corpus have been obtained. The standardization enabled the correct transformation of 96% of the terms from training and 98% from test the corpus. Due to the lack of terminologies exhaustively covering specific histone modification types, we developed a histone modification term hierarchy for use in a semantic text retrieval system. Conclusion The developed approach highly improves the retrieval of articles describing histone modifications. Since text contains context information about performed studies and experiments, the identification of histone modifications is the basis for supporting literature-based knowledge discovery and hypothesis generation to accelerate epigenomic research. PMID:19208128

Identification of histone modifications in biomedical text for supporting epigenomic research.

PubMed

Kolárik, Corinna; Klinger, Roman; Hofmann-Apitius, Martin

2009-01-30

Posttranslational modifications of histones influence the structure of chromatine and in such a way take part in the regulation of gene expression. Certain histone modification patterns, distributed over the genome, are connected to cell as well as tissue differentiation and to the adaption of organisms to their environment. Abnormal changes instead influence the development of disease states like cancer. The regulation mechanisms for modifying histones and its functionalities are the subject of epigenomics investigation and are still not completely understood. Text provides a rich resource of knowledge on epigenomics and modifications of histones in particular. It contains information about experimental studies, the conditions used, and results. To our knowledge, no approach has been published so far for identifying histone modifications in text. We have developed an approach for identifying histone modifications in biomedical literature with Conditional Random Fields (CRF) and for resolving the recognized histone modification term variants by term standardization. For the term identification F1 measures of 0.84 by 10-fold cross-validation on the training corpus and 0.81 on an independent test corpus have been obtained. The standardization enabled the correct transformation of 96% of the terms from training and 98% from test the corpus. Due to the lack of terminologies exhaustively covering specific histone modification types, we developed a histone modification term hierarchy for use in a semantic text retrieval system. The developed approach highly improves the retrieval of articles describing histone modifications. Since text contains context information about performed studies and experiments, the identification of histone modifications is the basis for supporting literature-based knowledge discovery and hypothesis generation to accelerate epigenomic research.

EDS1 contributes to nonhost resistance of Arabidopsis thaliana against Erwinia amylovora.

PubMed

Moreau, Manon; Degrave, Alexandre; Vedel, Régine; Bitton, Frédérique; Patrit, Oriane; Renou, Jean-Pierre; Barny, Marie-Anne; Fagard, Mathilde

2012-03-01

Erwinia amylovora causes fire blight in rosaceous plants. In nonhost Arabidopsis thaliana, E. amylovora triggers necrotic symptoms associated with transient bacterial multiplication, suggesting either that A. thaliana lacks a susceptibility factor or that it actively restricts E. amylovora growth. Inhibiting plant protein synthesis at the time of infection led to an increase in necrosis and bacterial multiplication and reduced callose deposition, indicating that A. thaliana requires active protein synthesis to restrict E. amylovora growth. Analysis of the callose synthase-deficient pmr4-1 mutant indicated that lack of callose deposition alone did not lead to increased sensitivity to E. amylovora. Transcriptome analysis revealed that approximately 20% of the genes induced following E. amylovora infection are related to defense and signaling. Analysis of mutants affected in NDR1 and EDS1, two main components of the defense-gene activation observed, revealed that E. amylovora multiplied ten times more in the eds1-2 mutant than in the wild type but not in the ndr1-1 mutant. Analysis of mutants affected in three WRKY transcription factors showing EDS1-dependent activation identified WRKY46 and WRKY54 as positive regulators and WRKY70 as a negative regulator of defense against E. amylovora. Altogether, we show that EDS1 is a positive regulator of nonhost resistance against E. amylovora in A. thaliana and hypothesize that it controls the production of several effective defenses against E. amylovora through the action of WRKY46 and WRKY54, while WRKY70 acts as a negative regulator.

Signalling requirements for Erwinia amylovora-induced disease resistance, callose deposition and cell growth in the non-host Arabidopsis thaliana.

PubMed

Hamdoun, Safae; Gao, Min; Gill, Manroop; Kwon, Ashley; Norelli, John L; Lu, Hua

2018-05-01

Erwinia amylovora is the causal agent of the fire blight disease in some plants of the Rosaceae family. The non-host plant Arabidopsis serves as a powerful system for the dissection of mechanisms of resistance to E. amylovora. Although not yet known to mount gene-for-gene resistance to E. amylovora, we found that Arabidopsis activated strong defence signalling mediated by salicylic acid (SA), with kinetics and amplitude similar to that induced by the recognition of the bacterial effector avrRpm1 by the resistance protein RPM1. Genetic analysis further revealed that SA signalling, but not signalling mediated by ethylene (ET) and jasmonic acid (JA), is required for E. amylovora resistance. Erwinia amylovora induces massive callose deposition on infected leaves, which is independent of SA, ET and JA signalling and is necessary for E. amylovora resistance in Arabidopsis. We also observed tumour-like growths on E. amylovora-infected Arabidopsis leaves, which contain enlarged mesophyll cells with increased DNA content and are probably a result of endoreplication. The formation of such growths is largely independent of SA signalling and some E. amylovora effectors. Together, our data reveal signalling requirements for E. amylovora-induced disease resistance, callose deposition and cell fate change in the non-host plant Arabidopsis. Knowledge from this study could facilitate a better understanding of the mechanisms of host defence against E. amylovora and eventually improve host resistance to the pathogen. © 2017 BSPP AND JOHN WILEY & SONS LTD.

Activation of pollen tube callose synthase by detergents. Evidence for different mechanisms of action.

PubMed Central

Li, H; Bacic, A; Read, S M

1997-01-01

In pollen tubes of Nicotiana alata, a membrane-bound, Ca(2+)-independent callose synthase (CalS) is responsible for the biosynthesis of the (1,3)-beta-glucan backbone of callose, the main cell wall component. Digitonin increases CalS activity 3- to 4-fold over a wide range of concentrations, increasing the maximum initial velocity without altering the Michaelis constant for UDP-glucose. The CalS activity that requires digitonin for assay (the latent CalS activity) is not inhibited by the membrane-impermeant, active site-directed reagent UDP-pyridoxal when the reaction is conducted in the absence of digitonin. This is consistent with digitonin increasing CalS activity by the permeabilization of membrane vesicles. A second group of detergents, including 3-[(3-cholamidopropyl)dimethylammonio]-1-propane-sulfonate (CHAPS), Zwittergent 3-16, and 1-alpha-lysolecithin, activate pollen tube CalS 10- to 15-fold, but only over a narrow range of concentrations just below their respective critical micellar concentrations. This activation could not be attributed to any particular chemical feature of these detergents. CHAPS increases maximum initial velocity and decreases the Michaelis constant for UDP-glucose and activates CalS even in the presence of permeabilizing concentrations of digitonin. Inhibition studies with UDP-pyridoxal indicate that activation by CHAPS occurs by recruitment of previously inactive CalS molecules to the pool of active enzyme. The activation of pollen tube CalS by these detergents therefore resembles activation of the enzyme by trypsin. PMID:9276948

Tie-dyed2 Encodes a Callose Synthase That Functions in Vein Development and Affects Symplastic Trafficking within the Phloem of Maize Leaves12[C][W][OA

PubMed Central

Slewinski, Thomas L.; Baker, R. Frank; Stubert, Adam; Braun, David M.

2012-01-01

The tie-dyed2 (tdy2) mutant of maize (Zea mays) displays variegated green and yellow leaves. Intriguingly, the yellow leaf tissues hyperaccumulate starch and sucrose, the soluble sugar transported long distance through the phloem of veins. To determine the molecular basis for Tdy2 function, we cloned the gene and found that Tdy2 encodes a callose synthase. RNA in situ hybridizations revealed that in developing leaves, Tdy2 was most highly expressed in the vascular tissue. Comparative expression analysis with the vascular marker maize PINFORMED1a-yellow fluorescent protein confirmed that Tdy2 was expressed in developing vein tissues. To ascertain whether the defect in tdy2 leaves affected the movement of sucrose into the phloem or its long-distance transport, we performed radiolabeled and fluorescent dye tracer assays. The results showed that tdy2 yellow leaf regions were defective in phloem export but competent in long-distance transport. Furthermore, transmission electron microscopy of tdy2 yellow leaf regions showed incomplete vascular differentiation and implicated a defect in cell-to-cell solute movement between phloem companion cells and sieve elements. The disruption of sucrose movement in the phloem in tdy2 mutants provides evidence that the Tdy2 callose synthase functions in vascular maturation and that the vascular defects result in impaired symplastic trafficking into the phloem translocation stream. PMID:22932757

Novelties of the flowering plant pollen tube underlie diversification of a key life history stage

PubMed Central

Williams, Joseph H.

2008-01-01

The origin and rapid diversification of flowering plants has puzzled evolutionary biologists, dating back to Charles Darwin. Since that time a number of key life history and morphological traits have been proposed as developmental correlates of the extraordinary diversity and ecological success of angiosperms. Here, I identify several innovations that were fundamental to the evolutionary lability of angiosperm reproduction, and hence to their diversification. In gymnosperms pollen reception must be near the egg largely because sperm swim or are transported by pollen tubes that grow at very slow rates (< ≈20 μm/h). In contrast, pollen tube growth rates of taxa in ancient angiosperm lineages (Amborella, Nuphar, and Austrobaileya) range from ≈80 to 600 μm/h. Comparative analyses point to accelerated pollen tube growth rate as a critical innovation that preceded the origin of the true closed carpel, long styles, multiseeded ovaries, and, in monocots and eudicots, much faster pollen tube growth rates. Ancient angiosperm pollen tubes all have callosic walls and callose plugs (in contrast, no gymnosperms have these features). The early association of the callose-walled growth pattern with accelerated pollen tube growth rate underlies a striking repeated pattern of faster and longer-distance pollen tube growth often within solid pathways in phylogenetically derived angiosperms. Pollen tube innovations are a key component of the spectacular diversification of carpel (flower and fruit) form and reproductive cycles in flowering plants. PMID:18678915

Grain setting defect1, Encoding a Remorin Protein, Affects the Grain Setting in Rice through Regulating Plasmodesmatal Conductance1[W

PubMed Central

Gui, Jinshan; Liu, Chang; Shen, Junhui; Li, Laigeng

2014-01-01

Effective grain filling is one of the key determinants of grain setting in rice (Oryza sativa). Grain setting defect1 (GSD1), which encodes a putative remorin protein, was found to affect grain setting in rice. Investigation of the phenotype of a transfer DNA insertion mutant (gsd1-Dominant) with enhanced GSD1 expression revealed abnormalities including a reduced grain setting rate, accumulation of carbohydrates in leaves, and lower soluble sugar content in the phloem exudates. GSD1 was found to be specifically expressed in the plasma membrane and plasmodesmata (PD) of phloem companion cells. Experimental evidence suggests that the phenotype of the gsd1-Dominant mutant is caused by defects in the grain-filling process as a result of the impaired transport of carbohydrates from the photosynthetic site to the phloem. GSD1 functioned in affecting PD conductance by interacting with rice ACTIN1 in association with the PD callose binding protein1. Together, our results suggest that GSD1 may play a role in regulating photoassimilate translocation through the symplastic pathway to impact grain setting in rice. PMID:25253885

Microtubule-Actin Crosslinking Factor 1 is required for dendritic arborization and axon outgrowth in the developing brain

PubMed Central

Ka, Minhan; Kim, Woo-Yang

2015-01-01

Dendritic arborization and axon outgrowth are critical steps in the establishment of neural connectivity in the developing brain. Changes in the connectivity underlie cognitive dysfunction in neurodevelopmental disorders. However, molecules and associated mechanisms that play important roles in dendritic and axon outgrowth in the brain are only partially understood. Here, we show that Microtubule-Actin Crosslinking Factor 1 (MACF1) regulates dendritic arborization and axon outgrowth of developing pyramidal neurons by arranging cytoskeleton components and mediating GSK-3 signaling. MACF1 deletion using conditional mutant mice and in utero gene transfer in the developing brain markedly decreased dendritic branching of cortical and hippocampal pyramidal neurons. MACF1-deficient neurons showed reduced density and aberrant morphology of dendritic spines. Also, loss of MACF1 impaired the elongation of callosal axons in the brain. Actin and microtubule arrangement appeared abnormal in MACF1-deficient neurites. Finally, we found that GSK-3 is associated with MACF1-controlled dendritic differentiation. Our findings demonstrate a novel role for MACF1 in neurite differentiation that is critical to the creation of neuronal connectivity in the developing brain. PMID:26526844

Boron Toxicity Causes Multiple Effects on Malus domestica Pollen Tube Growth.

PubMed

Fang, Kefeng; Zhang, Weiwei; Xing, Yu; Zhang, Qing; Yang, Liu; Cao, Qingqin; Qin, Ling

2016-01-01

Boron is an important micronutrient for plants. However, boron is also toxic to cells at high concentrations, although the mechanism of this toxicity is not known. This study aimed to evaluate the effect of boron toxicity on Malus domestica pollen tube growth and its possible regulatory pathway. Our results showed that a high concentration of boron inhibited pollen germination and tube growth and led to the morphological abnormality of pollen tubes. Fluorescent labeling coupled with a scanning ion-selective electrode technique detected that boron toxicity could decrease [Ca(2+)]c and induce the disappearance of the [Ca(2+)]c gradient, which are critical for pollen tube polar growth. Actin filaments were therefore altered by boron toxicity. Immuno-localization and fluorescence labeling, together with fourier-transform infrared analysis, suggested that boron toxicity influenced the accumulation and distribution of callose, de-esterified pectins, esterified pectins, and arabinogalactan proteins in pollen tubes. All of the above results provide new insights into the regulatory role of boron in pollen tube development. In summary, boron likely plays a structural and regulatory role in relation to [Ca(2+)]c, actin cytoskeleton and cell wall components and thus regulates Malus domestica pollen germination and tube polar growth.

Boron Toxicity Causes Multiple Effects on Malus domestica Pollen Tube Growth

PubMed Central

Fang, Kefeng; Zhang, Weiwei; Xing, Yu; Zhang, Qing; Yang, Liu; Cao, Qingqin; Qin, Ling

2016-01-01

Boron is an important micronutrient for plants. However, boron is also toxic to cells at high concentrations, although the mechanism of this toxicity is not known. This study aimed to evaluate the effect of boron toxicity on Malus domestica pollen tube growth and its possible regulatory pathway. Our results showed that a high concentration of boron inhibited pollen germination and tube growth and led to the morphological abnormality of pollen tubes. Fluorescent labeling coupled with a scanning ion-selective electrode technique detected that boron toxicity could decrease [Ca2+]c and induce the disappearance of the [Ca2+]c gradient, which are critical for pollen tube polar growth. Actin filaments were therefore altered by boron toxicity. Immuno-localization and fluorescence labeling, together with fourier-transform infrared analysis, suggested that boron toxicity influenced the accumulation and distribution of callose, de-esterified pectins, esterified pectins, and arabinogalactan proteins in pollen tubes. All of the above results provide new insights into the regulatory role of boron in pollen tube development. In summary, boron likely plays a structural and regulatory role in relation to [Ca2+]c, actin cytoskeleton and cell wall components and thus regulates Malus domestica pollen germination and tube polar growth. PMID:26955377

A comparison of aphasic and non-brain-injured adults on a dichotic CV-syllable listening task.

PubMed

Shanks, J; Ryan, W

1976-06-01

A dichotic CV-syllable listening task was administered to a group of eleven non-brain-injured adults and to a group of eleven adult aphasics. The results of this study may be summarized as follows: 1)The group of non-brain-injured adults showed a slight right ear advantage for dichotically presented CV-syllables. 2)In comparison with the control group the asphasic group showed a bilateral deficit in response to the dichotic CV-syllables, superimposed on a non-significant right ear advantage. 3) The asphasic group demonstrated a great deal of intersubject variability on the dichotic task with six aphasics showing a right ear preference for the stimuli. The non-brain-injured subjects performed more homogeneously on the task. 4) The two subgroups of aphasics, a right ear advantage group and a left ear advantage group, performed significantly different on the dichotic listening task. 5) Single correct data analysis proved valuable by deleting accuracy of report for an examination of trials in which there was true competition for the single left hemispheric speech processor. These results were analyzed in terms of a functional model of auditory processing. In view of this model, the bilateral deficit in dichotic performance of the asphasic group was accounted for by the presence of a lesion within the dominant left hemisphere, where the speech signals from both ears converge for final processing. The right ear advantage shown by one asphasic subgroup was explained by a lesion interfering with the corpus callosal pathways from the left hemisphere; the left ear advantage observed within the other subgroup was explained by a lesion in the area of the auditory processor of the left hemisphere.

Alterations of parenchymal microstructure, neuronal connectivity and cerebrovascular resistance at adolescence following mild to moderate traumatic brain injury in early development.

PubMed

Parent, Maxime; Li, Ying; Santhakumar, Vijayalakshmi; Hyder, Fahmeed; Sanganahalli, Basavaraju G; Kannurpatti, Sridhar

2018-06-01

TBI is a leading cause of morbidity in children. To investigate outcome of early developmental TBI during adolescence, a rat model of fluid percussion injury was developed, where previous work reported deficits in sensorimotor behavior and cortical blood flow at adolescence. 1 Based on the non-localized outcome, we hypothesized that multiple neurophysiological components of brain function, namely neuronal connectivity, synapse/axonal microstructural integrity and neurovascular function are altered and magnetic resonance imaging (MRI) methods could be used to determine regional alterations. Adolescent outcomes of developmental TBI were studied 2-months after injury, using functional MRI (fMRI) and Diffusion Tensor Imaging (DTI). fMRI based resting state functional connectivity (RSFC), representing neural connectivity, was significantly altered between sham and TBI. RSFC strength decreased in the cortex, hippocampus and thalamus accompanied by decrease in the spatial extent of their corresponding RSFC networks and inter-hemispheric asymmetry. Cerebrovascular reactivity to arterial CO2 changes diminished after TBI across both hemispheres, with a more pronounced decrease in the ipsilateral hippocampus, thalamus and motor cortex. DTI measures of fractional anisotropy (FA) and apparent diffusion coefficient (ADC), reporting on axonal and microstructural integrity of the brain, indicated similar inter-hemispheric asymmetry, with highest change in the ipsilateral hippocampus and regions adjoining the ipsilateral thalamus, hypothalamus and amygdala. TBI-induced corpus callosal microstructural alterations indicated measurable changes in inter-hemispheric structural connectivity. Hippocampus, thalamus and select cortical regions were most consistently affected in multiple imaging markers. The multi-modal MRI results demonstrate cortical and subcortical alterations in neural connectivity, cerebrovascular resistance and parenchymal microstructure in the adolescent brain, indicating the highly diffuse and persistent nature of the lateral fluid percussion TBI early in development.

Role of testosterone and Y chromosome genes for the masculinization of the human brain.

PubMed

Savic, Ivanka; Frisen, Louise; Manzouri, Amirhossein; Nordenstrom, Anna; Lindén Hirschberg, Angelica

2017-04-01

Women with complete androgen insensitivity syndrome (CAIS) have a male (46,XY) karyotype but no functional androgen receptors. Their condition, therefore, offers a unique model for studying testosterone effects on cerebral sex dimorphism. We present MRI data from 16 women with CAIS and 32 male (46,XY) and 32 female (46,XX) controls. FreeSurfer software was employed to measure cortical thickness and subcortical structural volumes. Axonal connections, indexed by fractional anisotropy, (FA) were measured with diffusion tensor imaging, and functional connectivity with resting state fMRI. Compared to men, CAIS women displayed a "female" pattern by having thicker parietal and occipital cortices, lower FA values in the right corticospinal, superior and inferior longitudinal tracts, and corpus callosum. Their functional connectivity from the amygdala to the medial prefrontal cortex, was stronger and amygdala-connections to the motor cortex weaker than in control men. CAIS and control women also showed stronger posterior cingulate and precuneus connections in the default mode network. Thickness of the motor cortex, the caudate volume, and the FA in the callosal body followed, however, a "male" pattern. Altogether, these data suggest that testosterone modulates the microstructure of somatosensory and visual cortices and their axonal connections to the frontal cortex. Testosterone also influenced functional connections from the amygdala, whereas the motor cortex could, in agreement with our previous reports, be moderated by processes linked to X-chromosome gene dosage. These data raise the question about other genetic factors masculinizing the human brain than the SRY gene and testosterone. Hum Brain Mapp 38:1801-1814, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Callosotomy affects performance IQ: A meta-analysis of individual participant data.

PubMed

Westerhausen, René; Karud, Celine M R

2018-02-05

Morphometric neuroimaging studies on healthy adult individuals regularly report a positive association between intelligence test performance (IQ) and structural properties of the corpus callosum (CC). At the same time, studies examining the effect of callosotomy on epilepsy patients report only negligible changes in IQ as result of the surgery, partially contradicting the findings of the morphometry studies. Objective of the present meta-analysis of individual participant data (IPD) of 87 cases from 16 reports was to re-investigate the effect of callosotomy on full scale IQ as well as on the verbal and performance subscale under special consideration of two possible moderating factors: pre-surgical IQ levels and the extent of the surgery (complete vs. anterior transsection). The main finding was that callosotomy selectively affects performance IQ, whereby the effect is modulated by the pre-surgical level of performance. Patients with an above-median pre-surgery performance IQ level show a significant average decrease of -5.44 (CI 95% : - 8.33 to - 2.56) IQ points following the surgery, while the below-median group does not reveal a significant change in IQ (mean change: 1.01 IQ points; CI 95% : -1.83 to 3.86). Thus, the present analyses support the notion that callosotomy has a negative effect on the patients' performance IQ, but only in those patients, who at least have an average performance levels before the surgery. This observation also lends support to the findings of previous morphometry studies, indicating that the frequently observed CC-IQ correlation might indeed reflect a functional contribution of callosal interhemispheric connectivity to intelligence-test performance. Copyright © 2017 The Author(s). Published by Elsevier B.V. All rights reserved.

Structural integrity of callosal midbody influences intermanual transfer in a motor reaction-time task.

PubMed

Bonzano, Laura; Tacchino, Andrea; Roccatagliata, Luca; Mancardi, Giovanni Luigi; Abbruzzese, Giovanni; Bove, Marco

2011-02-01

Training one hand on a motor task results in performance improvements in the other hand, also when stimuli are randomly presented (nonspecific transfer). Corpus callosum (CC) is the main structure involved in interhemispheric information transfer; CC pathology occurs in patients with multiple sclerosis (PwMS) and is related to altered performance of tasks requiring interhemispheric transfer of sensorimotor information. To investigate the role of CC in nonspecific transfer during a pure motor reaction-time task, we combined motor behavior with diffusion tensor imaging analysis in PwMS. Twenty-two PwMS and 10 controls, all right-handed, were asked to respond to random stimuli with appropriate finger opposition movements with the right (learning) and then the left (transfer) hand. PwMS were able to improve motor performance reducing response times with practice with a trend similar to controls and preserved the ability to transfer the acquired motor information from the learning to the transfer hand. A higher variability in the transfer process, indicated by a significantly larger standard deviation of mean nonspecific transfer, was found in the PwMS group with respect to the control group, suggesting the presence of subtle impairments in interhemispheric communication in some patients. Then, we correlated the amount of nonspecific transfer with mean fractional anisotropy (FA) values, indicative of microstructural damage, obtained in five CC subregions identified on PwMS's FA maps. A significant correlation was found only in the subregion including posterior midbody (Pearson's r = 0.74, P = 0.003), which thus seems to be essential for the interhemispheric transfer of information related to pure sensorimotor tasks. Copyright © 2010 Wiley-Liss, Inc.

Hypomelanosis of Ito: neurological and psychiatric pictures in developmental age.

PubMed

Parisi, L; Di Filippo, T; Roccella, M

2012-02-01

Hypomelanosis of Ito (HOI) is a multisystem neurocutaneous disorder. In the described cases, cutaneous manifestations (unilateral or bilateral streaks and swirls of hypomelanosis with regular and confluent borders) and extracutaneous abnormalities are often associated. Extracutaneous abnormalities involve the musculoskeletal system (scoliosis, vertebral anomalies, cranial-facial malformations) and other organs, as well as the central nervous system (CNS). The most significant anomalies of the CNS are psychomotor retardation and cognitive deficit. Autism, epilepsy, language disorders, cerebral malformations (neural migration disorders, cerebral hypoplasia, cortical atrophy, agenesis of the corpus callosum) are sometimes present. Numerous abnormal chromosomal patterns have been observed. HOI is usually a sporadic disorder; though autosomal dominant transmission has been suggested, recessive and X-linked inheritance patterns have also been reported. This study describes five children with HOI presenting with various features of the clinical spectrum of the syndrome. Some of these cases were referred for psychomotor therapy as part of an integrated neuropsychologic and psychomotor treatment support program. In this view, psychomotor treatment aims to promote the emotional-relational component, to overcome rigid divisions, and to integrate learning-related cognitive aspects with psychodynamic concepts. Finally, the goals of psychological and social support are to help the parents accept their child's handicap, understand the child's behavior, plan future pregnancies, and foster an environment for their child's integration.

Health and Recovery Program in Increasing Physical Activity Level in Stage IA-IIIA Endometrial Cancer Survivors

ClinicalTrials.gov

2018-03-05

Cancer Survivor; Endometrial Carcinoma; Stage I Uterine Corpus Cancer AJCC v7; Stage IA Uterine Corpus Cancer AJCC v7; Stage IB Uterine Corpus Cancer AJCC v7; Stage II Uterine Corpus Cancer AJCC v7; Stage IIIA Uterine Corpus Cancer AJCC v7

The Corpus Callosum and Reading: An MRI Volumetric Study

ERIC Educational Resources Information Center

Fine, Jodene Goldenring

2006-01-01

Researchers have long been interested in the role of the corpus callosum in reading disorder, but existing studies have yielded inconsistent results. Some have found larger corpus callosa in those with reading disorder, others have found smaller corpus callosa, and some have found no differences in the corpus callosa of persons with and without…

The epileptology of Koolen-de Vries syndrome: Electro-clinico-radiologic findings in 31 patients.

PubMed

Myers, Kenneth A; Mandelstam, Simone A; Ramantani, Georgia; Rushing, Elisabeth J; de Vries, Bert B; Koolen, David A; Scheffer, Ingrid E

2017-06-01

This study was designed to describe the spectrum of epilepsy phenotypes in Koolen-de Vries syndrome (KdVS), a genetic syndrome involving dysmorphic features, intellectual disability, hypotonia, and congenital malformations, that occurs secondary to 17q21.31 microdeletions and heterozygous mutations in KANSL1. We were invited to attend a large gathering of individuals with KdVS and their families. While there, we recruited individuals with KdVS and seizures, and performed thorough phenotyping. Additional subjects were included who approached us after the family support group brought attention to our research via social media. Inclusion criteria were genetic testing results demonstrating 17q21.31 deletion or KANSL1 mutation, and at least one seizure. Thirty-one individuals were studied, aged 2-35 years. Median age at seizure onset was 3.5 years, and 9 of 22 had refractory seizures 2 years after onset. Focal impaired awareness seizures were the most frequent seizure type occurring in 20 of 31, usually with prominent autonomic features. Twenty-one patients had prolonged seizures and, at times, refractory status epilepticus. Electroencephalography (EEG) showed focal/multifocal epileptiform discharges in 20 of 26. MRI studies of 13 patients were reviewed, and all had structural anomalies. Corpus callosum dysgenesis, abnormal hippocampi, and dilated ventricles were the most common, although periventricular nodular heterotopia, focal cortical dysplasia, abnormal sulcation, and brainstem and cerebellum abnormalities were also observed. One patient underwent epilepsy surgery for a lesion that proved to be an angiocentric glioma. The typical epilepsy phenotype of KdVS involves childhood-onset focal seizures that are prolonged and have prominent autonomic features. Multifocal epileptiform discharges are the typical EEG pattern. Structural brain abnormalities may be universal, including signs of abnormal neuroblast migration and abnormal axonal guidance. Epilepsy surgery should be undertaken with care given the widespread neuroanatomic abnormalities; however, tumors are a rare, yet important, occurrence. Wiley Periodicals, Inc. © 2017 International League Against Epilepsy.

Prenatal neurologic anomalies: sonographic diagnosis and treatment.

PubMed

De Catte, Luc; De Keersmaeker, Bart; Claus, Filip

2012-06-01

The low prevalence of fetal CNS anomalies results in a restricted level of exposure to, and limited experience for most obstetricians involved in, prenatal ultrasound. Sonographic guidelines for screening the fetal brain in a systematic way may increase the detection rate of fetal CNS anomalies, thus promoting correct referral to tertiary care centers offering patients a multidisciplinary approach to the condition. The aim of this review is to elaborate on the prenatal sonographic diagnosis and outcome of various CNS malformations. Detailed neurosonographic investigation has become available through high-resolution vaginal ultrasound probes and the development of a variety of 3-dimensional (3D) ultrasound modalities, such as ultrasound tomographic imaging. In addition, fetal magnetic resonance imaging is particularly helpful in the detection of gyration and neurulation anomalies, and disorders of the gray and white matter. Isolated mild ventriculomegaly is a rather common finding with good overall outcome. With an increasing diameter of the atria, however, and especially with the presence of associated malformations, long-term neurodevelopmental and behavioral outcome is disturbed in about 15% or more of cases. In view of recent developments in fetal therapy for neural tube defects, there is a clear need for a high level of ultrasound screening, work-up and counseling in tertiary care centers to identify those cases that might benefit from in utero intervention. The failure of prosencephalic midline induction and development results in midline defects ranging from alobar holoprosencephaly to isolated corpus callosum defects. The detection of callosal abnormaties is enhanced by 3D ultrasound, but counseling on neurodevelopmental outcome remains challenging. The Dandy-Walker spectrum includes isolated megacisterna magna, Blake's pouch cyst, hypoplasia of the vermis and Dandy-Walker malformation. Except for complete agenesis of the vermis associated with fourth ventricle cyst formation, data on long-term outcomes for the various conditions is largely lacking. Congenital cytomegalovirus (CMV) results in the highest incidence of children born with, or developing, long-term neurologic conditions. If proof of fetal infection has been delivered, microcephaly, cortical malformations, and intraparenchymal cysts show a strong correlation with poor outcome. Fetuses with CMV-related ultrasound abnormalities might benefit from maternal transplacental treatment. The aneurysm of the vein of Galen, a vascular malformation of the brain, often results in high cardiac output failure. After neonatal arterial embolization, survival is about 50% with normal neurologic development in 36% of cases. Over 50% of intracranial tumors are teratomata, presenting as fast-growing heterogeneous solid-cystic masses with calcifications. Most intracranial hemorrhages are related to the ventricular system, and prognosis is often poor, particularly in cases involving parenchymal and subdural bleeding. Proliferation disorders of the brain are often characterized by microcephaly. Their etiology is heterogeneous and prenatal diagnosis is often made late in gestation.

[Congenital mydriasis as an initial sign of septo-optic dysplasia].

PubMed

Carrascosa-Romero, M C; Ruiz-Cano, R; Martínez-López, F; Alfaro-Ponce, B; Pérez-Pardo, A

2013-10-01

Septo-optic dysplasia (SOD)[MIM182230] consisting of a heterogeneous and uncommon condition characterised by the classictriad: optic nerve hypoplasia, abnormalities of pituitary hormone, and defects of thebrain midline (including agenesis of the septum pellucidum and/or the corpus callosum; ithas also been described associated cortical malformations, it was referred to as SOD plus syndrome).We report the first known case in which the initial diagnostic sign of SOD was a bilateralmydriasis as a manifestation ofhypoplasia of both optic nerves, pituitary hypoplasia andcerebral dysgenesis with neuronal migration disorder.We discuss thedifferential diagnosis of congenital mydriasis. Copyright © 2010 Sociedad Española de Oftalmología. Published by Elsevier Espana. All rights reserved.

Correlations of diffusion tensor imaging values and symptom scores in patients with schizophrenia.

PubMed

Michael, Andrew M; Calhoun, Vince D; Pearlson, Godfrey D; Baum, Stefi A; Caprihan, Arvind

2008-01-01

Abnormalities in white matter (WM) brain regions are attributed as a possible biomarker for schizophrenia (SZ). Diffusion tensor imaging (DTI) is used to capture WM tracts. Psychometric tests that evaluate the severity of symptoms of SZ are clinically used in the diagnosis process. In this study we investigate the correlates of scalar DTI measures, such as fractional anisotropy, mean diffusivity, axial diffusivity, and radial diffusivity with behavioral test scores. The correlations were found by different schemes: mean correlation with WM atlas regions and multiple regression of DTI values with test scores. The corpus callosum, superior longitudinal fasciculus right and inferior longitudinal fasciculus left were found to be having high correlations with test scores.

Multimodal voxel-based meta-analysis of white matter abnormalities in obsessive-compulsive disorder.

PubMed

Radua, Joaquim; Grau, Mar; van den Heuvel, Odile A; Thiebaut de Schotten, Michel; Stein, Dan J; Canales-Rodríguez, Erick J; Catani, Marco; Mataix-Cols, David

2014-06-01

White matter (WM) abnormalities have long been suspected in obsessive-compulsive disorder (OCD) but the available evidence has been inconsistent. We conducted the first multimodal meta-analysis of WM volume (WMV) and fractional anisotropy (FA) studies in OCD. All voxel-wise studies comparing WMV or FA between patients with OCD and healthy controls in the PubMed, ScienceDirect, Google Scholar, Web of Knowledge and Scopus databases were retrieved. Manual searches were also conducted and authors were contacted soliciting additional data. Thirty-four data sets were identified, of which 22 met inclusion criteria (five of them unpublished; comprising 537 adult and pediatric patients with OCD and 575 matched healthy controls). Whenever possible, raw statistical parametric maps were also obtained from the authors. Peak and raw WMV and FA data were combined using novel multimodal meta-analytic methods implemented in effect-size signed differential mapping. Patients with OCD showed widespread WM abnormalities, but findings were particularly robust in the anterior midline tracts (crossing between anterior parts of cingulum bundle and body of corpus callosum), which showed both increased WMV and decreased FA, possibly suggesting an increase of fiber crossing in these regions. This finding was also observed when the analysis was limited to adult participants, and especially pronounced in samples with a higher proportion of medicated patients. Therefore, patients with OCD may have widespread WM abnormalities, particularly evident in anterior midline tracts, although these changes might be, at least in part, attributable to the effects of therapeutic drugs.

Pyridoxine-Dependent Epilepsy: An Expanding Clinical Spectrum.

PubMed

van Karnebeek, Clara D M; Tiebout, Sylvia A; Niermeijer, Jikkemien; Poll-The, Bwee Tien; Ghani, Aisha; Coughlin, Curtis R; Van Hove, Johan L K; Richter, Jost Wigand; Christen, Hans Juergen; Gallagher, Renata; Hartmann, Hans; Stockler-Ipsiroglu, Sylvia

2016-06-01

Pyridoxine-dependent epilepsy is a rare autosomal recessive epileptic encephalopathy caused by antiquitin (ALDH7A1) deficiency. In spite of adequate seizure control, 75% of patients suffer intellectual developmental disability. Antiquitin deficiency affects lysine catabolism resulting in accumulation of α-aminoadipic semialdehyde/pyrroline 6' carboxylate and pipecolic acid. Beside neonatal refractory epileptic encephalopathy, numerous neurological manifestations and metabolic/biochemical findings have been reported. We present a phenotypic spectrum of antiquitin deficiency based on a literature review (2006 to 2015) of reports (n = 49) describing the clinical presentation of confirmed patients (n > 200) and a further six patient vignettes. Possible presentations include perinatal asphyxia; neonatal withdrawal syndrome; sepsis; enterocolitis; hypoglycemia; neuroimaging abnormalities (corpus callosum and cerebellar abnormalities, hemorrhage, white matter lesions); biochemical abnormalities (lactic acidosis, electrolyte disturbances, neurotransmitter abnormalities); and seizure response to pyridoxine, pyridoxal-phosphate, and folinic acid dietary interventions. The phenotypic spectrum of pyridoxine-dependent epilepsy is wide, including a myriad of neurological and systemic symptoms. Its hallmark feature is refractory seizures during the first year of life. Given its amenability to treatment with lysine-lowering strategies in addition to pyridoxine supplementation for optimal seizure control and developmental outcomes, early diagnosis of pyridoxine-dependent epilepsy is essential. All infants presenting with unexplained seizures should be screened for antiquitin deficiency by determination of α-aminoadipic semialdehyde/pyrroline 6' carboxylate (in urine, plasma or cerebrospinal fluid) and ALDH7A1 molecular analysis. Copyright © 2016 Elsevier Inc. All rights reserved.

Comprehensive Patient Questionnaires in Predicting Complications in Older Patients With Gynecologic Cancer Undergoing Surgery

ClinicalTrials.gov

2018-02-14

Endometrial Serous Adenocarcinoma; Fallopian Tube Carcinoma; Ovarian Carcinoma; Primary Peritoneal Carcinoma; Stage IIIA Uterine Corpus Cancer AJCC v7; Stage IIIB Uterine Corpus Cancer AJCC v7; Stage IIIC Uterine Corpus Cancer AJCC v7; Stage IVA Uterine Corpus Cancer AJCC v7; Stage IVB Uterine Corpus Cancer AJCC v7

Microstructural Changes to the Brain of Mice after Methamphetamine Exposure as Identified with Diffusion Tensor Imaging

PubMed Central

McKenna, Benjamin S.; Brown, Gregory G.; Archibald, Sarah; Scadeng, Miriam; Bussell, Robert; Kesby, James P.; Markou, Athina; Soontornniyomkij, Virawudh; Achim, Cristian; Semenova, Svetlana

2016-01-01

Methamphetamine (METH) is an addictive psychostimulant inducing neurotoxicity. Human magnetic resonance imaging and diffusion tensor imaging (DTI) of METH-dependent participants find various structural abnormities. Animal studies demonstrate immunohistochemical changes in multiple cellular pathways after METH exposure. Here, we characterized the long-term effects of METH on brain microstructure in mice exposed to an escalating METH binge regimen using in vivo DTI, a methodology directly translatable across species. Results revealed four patterns of differential fractional anisotropy (FA) and mean diffusivity (MD) response when comparing METH-exposed (n=14) to saline-treated mice (n=13). Compared to the saline group, METH-exposed mice demonstrated: 1) decreased FA with no change in MD [corpus callosum (posterior forceps), internal capsule (left), thalamus (medial aspects), midbrain], 2) increased MD with no change in FA [posterior isocortical regions, caudate-putamen, hypothalamus, cerebral peduncle, internal capsule (right)], 3) increased FA with decreased MD [frontal isocortex, corpus callosum (genu)], and 4) increased FA with no change or increased MD [hippocampi, amygdala, lateral thalamus]. MD was negatively associated with calbindin-1 in hippocampi and positively with dopamine transporter in caudate-putamen. These findings highlight distributed and differential METH effects within the brain suggesting several distinct mechanisms. Such mechanisms likely change brain tissue differentially dependent upon neural location. PMID:27000304

Detecting corpus callosum abnormalities in autism based on anatomical landmarks

PubMed Central

He, Qing; Duan, Ye; Karsch, Kevin; Miles, Judith

2010-01-01

Autism is a severe developmental disorder whose neurological basis is largely unknown. Autism is a subtype of autism that displays more homogeneous features within group. The aim of this study was to identify the shape differences of the corpus callosum between patients with autism and the controls. Anatomical landmarks were collected from mid-sagittal MRI of 25 patients and 18 controls. Euclidean distance matrix analysis and thin-plate spline were used to analyze the landmark forms. Point-by-point shape comparison was performed both globally and locally. A new local shape comparison scheme was proposed which compared each part of the shape in its local coordinate system. Point correspondence was established among individual shapes based on the inherent landmark correspondence. No significant difference was found in the landmark form between patients and controls, but the distance between interior genu and posterior most was found significantly shorter in patients. Thin-plate spline analysis showed significant group difference between the landmark configurations in terms of the deformation from the overall mean configuration. Significant global shape differences were found in the anterior lower body and posterior bottom, and local shape difference existed in the anterior bottom. This study can serve as both clinical reference and a detailed procedure guideline for similar studies in the future. PMID:20620032

Acute infarction of corpus callosum due to transient obstructive hydrocephalus.

PubMed

Kaymakamzade, Bahar; Eker, Amber

2016-01-01

Acute ischemia of the corpus callosum (CC) is not a well-known feature in patients with acute hydrocephalus. Herein, we describe a case with acute CC infarction due to another rare entity; transient obstructive hydrocephalus. A 66-year-old male was admitted with sudden onset right-sided hemiparesia. CT demonstrated a hematoma on the left basal ganglia with extension to all ventricles. The following day, the patient's neurological status progressed to coma and developed bilateral pyramidal signs. MRI demonstrated obstructive hydrocephalus and acute diffuse infarction accompanied by elevation of the CC. On the same day there was improvement in his neurological status with significant decrease in ventricular size and complete resolution of the clot in the third ventricle. The mechanism of signal abnormalities is probably related with the neural compression of the CC against the falx. Presumably, the clot causing obstruction in the third ventricle dissolved or decayed by the help of fibrinolytic activity of CSF, which was raised after IVH and caused spontaneous improvement of hydrocephalus. Bilateral neurological symptoms suggest diffuse axonal damage and normalization of the intracranial pressure should be performed on the early onset of clinical detorioration in order to prevent axonal injury. Copyright © 2016 Polish Neurological Society. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

Diffuse corpus callosum infarction - Rare vascular entity with differing etiology.

PubMed

Mahale, Rohan; Mehta, Anish; Buddaraju, Kiran; John, Aju Abraham; Javali, Mahendra; Srinivasa, Rangasetty

2016-01-15

Infarctions of the corpus callosum are rare vascular events. It is relatively immune to vascular insult because of its rich vascular supply from anterior and posterior circulations of brain. Report of 3 patients with largely diffuse acute corpus callosum infarction. 3 patients with largely diffuse acute corpus callosum infarction were studied and each of these 3 patients had 3 different aetiologies. The 3 different aetiologies of largely diffuse acute corpus callosum infarction were cardioembolism, tuberculous arteritis and takayasu arteritis. Diffuse corpus callosum infarcts are rare events. This case series narrates the three different aetiologies of diffuse acute corpus callosum infarction which is a rare vascular event. Copyright © 2015 Elsevier B.V. All rights reserved.

77 FR 34034 - Corpus Christi Liquefaction, LLC; Cheniere Corpus Christi Pipeline, L.P.; Notice of Intent To...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-08

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. PF12-3-000] Corpus Christi Liquefaction, LLC; Cheniere Corpus Christi Pipeline, L.P.; Notice of Intent To Prepare an Environmental Assessment for the Planned Corpus Christi LNG Terminal and Pipeline Project, Request for Comments on Environmental Issues, and Notice of Public...

Suppressing a Putative Sterol Carrier Gene Reduces Plasmodesmal Permeability and Activates Sucrose Transporter Genes during Cotton Fiber Elongation.

PubMed

Zhang, Zhiyuan; Ruan, Yong-Ling; Zhou, Na; Wang, Fang; Guan, Xueying; Fang, Lei; Shang, Xiaoguang; Guo, Wangzhen; Zhu, Shuijin; Zhang, Tianzhen

2017-08-01

Plasmodesmata (PDs) play vital roles in cell-to-cell communication and plant development. Emerging evidence suggests that sterols are involved in PD activity during cytokinesis. However, whether sterols contribute to PD gating between established cells remains unknown. Here, we isolated GhSCP2D , a putative sterol carrier protein gene from elongating cotton ( Gossypium hirsutum ) fibers. In contrast to wild-type fiber PDs, which opened at 5 to 10 d postanthesis (DPA) and closed only at 15 to 25 DPA, plants with suppressed GhSCP2D expression had reduced sterol contents and closed PDs at 5 through 25 DPA The GhSCP2D- suppressed fibers exhibited callose deposition at the PDs, likely due to reduced expression of GhPdBG3-2A/D , which encodes a PD-targeting β-1,3-glucanase. Both GhPdBG3-2A/D expression and callose deposition were sensitive to a sterol biosynthesis inhibitor. Moreover, suppressing GhSCP2D upregulated a cohort of SUT and SWEET sucrose transporter genes in fiber cells. Collectively, our results indicate that (1) GhSCP2D is required for GhPdBG3-2A/D expression to degrade callose at the PD, thereby contributing to the establishment of the symplasmic pathway; and (2) blocking the symplasmic pathway by downregulating GhSCP2D activates or increases the expression of SUTs and SWEETs , leading to the switch from symplasmic to apoplasmic pathways. © 2017 American Society of Plant Biologists. All rights reserved.

Arabidopsis ARF-GTP exchange factor, GNOM, mediates transport required for innate immunity and focal accumulation of syntaxin PEN1

PubMed Central

Nielsen, Mads Eggert; Feechan, Angela; Böhlenius, Henrik; Ueda, Takashi; Thordal-Christensen, Hans

2012-01-01

Penetration resistance to powdery mildew fungi, conferred by localized cell wall appositions (papillae), is one of the best-studied processes in plant innate immunity. The syntaxin PENETRATION (PEN)1 is required for timely appearance of papillae, which contain callose and extracellular membrane material, as well as PEN1 itself. Appearance of membrane material in papillae suggests secretion of exosomes. These are potentially derived from multivesicular bodies (MVBs), supported by our observation that ARA6-labeled organelles assemble at the fungal attack site. However, the trafficking components that mediate delivery of extracellular membrane material are unknown. Here, we show that the delivery is independent of PEN1 function. Instead, we find that application of brefeldin (BF)A blocks the papillary accumulation of GFP-PEN1–labeled extracellular membrane and callose, while impeding penetration resistance. We subsequently provide evidence indicating that the responsible BFA-sensitive ADP ribosylation factor–GTP exchange factor (ARF-GEF) is GNOM. Firstly, analysis of the transheterozygote gnomB4049/emb30-1 (gnomB/E) mutant revealed a delay in papilla formation and reduced penetration resistance. Furthermore, a BFA-resistant version of GNOM restored the BFA-sensitive papillary accumulation of GFP-PEN1 and callose. Our data, therefore, provide a link between GNOM and disease resistance. We suggest that papilla formation requires rapid reorganization of material from the plasma membrane mediated by GNOM. The papilla material is subsequently presumed to be sorted into MVBs and directed to the site of fungal attack, rendering the epidermal plant cell inaccessible for the invading powdery mildew fungus. PMID:22733775

Chilling of Dormant Buds Hyperinduces FLOWERING LOCUS T and Recruits GA-Inducible 1,3-β-Glucanases to Reopen Signal Conduits and Release Dormancy in Populus[W][OA

PubMed Central

Rinne, Päivi L.H.; Welling, Annikki; Vahala, Jorma; Ripel, Linda; Ruonala, Raili; Kangasjärvi, Jaakko; van der Schoot, Christiaan

2011-01-01

In trees, production of intercellular signals and accessibility of signal conduits jointly govern dormancy cycling at the shoot apex. We identified 10 putative cell wall 1,3-β-glucanase genes (glucan hydrolase family 17 [GH17]) in Populus that could turn over 1,3-β-glucan (callose) at pores and plasmodesmata (PD) and investigated their regulation in relation to FT and CENL1 expression. The 10 genes encode orthologs of Arabidopsis thaliana BG_ppap, a PD-associated glycosylphosphatidylinositol (GPI) lipid-anchored protein, the Arabidopsis PD callose binding protein PDCB, and a birch (Betula pendula) putative lipid body (LB) protein. We found that these genes were differentially regulated by photoperiod, by chilling (5°C), and by feeding of gibberellins GA3 and GA4. GA3 feeding upregulated all LB-associated GH17s, whereas GA4 upregulated most GH17s with a GPI anchor and/or callose binding motif, but only GA4 induced true bud burst. Chilling upregulated a number of GA biosynthesis and signaling genes as well as FT, but not CENL1, while the reverse was true for both GA3 and GA4. Collectively, the results suggest a model for dormancy release in which chilling induces FT and both GPI lipid-anchored and GA3-inducible GH17s to reopen signaling conduits in the embryonic shoot. When temperatures rise, the reopened conduits enable movement of FT and CENL1 to their targets, where they drive bud burst, shoot elongation, and morphogenesis. PMID:21282527

Effects of Exogenous Plant Growth Regulator Abscisic Acid-Induced Resistance in Rice on the Expression of Vitellogenin mRNA in Nilaparvata lugens (Hemiptera: Delphacidae) Adult Females

PubMed Central

Liu, Jing-Lan; Chen, Xiao; Zhang, Hong-Mei; Yang, Xia; Wong, Andrew

2014-01-01

Abstract Recent study showed that exogenous abscisic acid (ABA) acts as a regulator of plant resistance. This study investigated average injury scale and callose contents of rice, and vitellogenin ( Nlvg ) mRNA expression in Nilaparvata lugens (Stål) (Hemiptera: Delphacidae) adult females after third instar nymphs fed on exogenous ABA-treated susceptible [Taichung Native one (TN1)] and moderately resistant (IR42) rice cultivars. The results showed that exogenous ABA significantly decreased average injury scale of rice and Nlvg mRNA expression in N. lugens adults compared with the control (without ABA spraying). Nlvg mRNA expression in N. lugens adults decreased significantly after third instar nymphs fed on ABA-treated (5, 20, and 40 mg/liter) TN1 for 1 and 2 d, and for IR42, after fed on ABA-treated (20 and 40 mg/liter) rice plants for 1 d and after fed on ABA-treated (5, 20, and 40 mg/liter) rice for 2 d decreased significantly. The callose contents showed no significant change for TN1, while for IR42, significantly increased in roots and sheathes after N. lugens infestation under ABA treatments (20 and 40 mg/liter) compared with the control. The decrease of Nlvg mRNA expression may be partially attributed to the increase of callose content of plants. The results provide a profile for concerning the effects of ABA-induced rice plants’ defenses on phloem-feeding insects. PMID:25502025

Patient, Physician, and Nurse Factors Associated With Entry Onto Clinical Trials and Finishing Treatment in Patients With Primary or Recurrent Uterine, Endometrial, or Cervical Cancer

ClinicalTrials.gov

2018-04-11

Recurrent Cervical Carcinoma; Recurrent Uterine Corpus Carcinoma; Recurrent Uterine Corpus Sarcoma; Stage I Uterine Corpus Cancer; Stage I Uterine Sarcoma; Stage IA Cervical Cancer; Stage IB Cervical Cancer; Stage II Uterine Corpus Cancer; Stage II Uterine Sarcoma; Stage IIA Cervical Cancer; Stage IIB Cervical Cancer; Stage III Cervical Cancer; Stage III Uterine Corpus Cancer; Stage III Uterine Sarcoma; Stage IV Uterine Corpus Cancer; Stage IV Uterine Sarcoma; Stage IVA Cervical Cancer; Stage IVB Cervical Cancer

Axonal abnormalities in vanishing white matter.

PubMed

Klok, Melanie D; Bugiani, Marianna; de Vries, Sharon I; Gerritsen, Wouter; Breur, Marjolein; van der Sluis, Sophie; Heine, Vivi M; Kole, Maarten H P; Baron, Wia; van der Knaap, Marjo S

2018-04-01

We aimed to study the occurrence and development of axonal pathology and the influence of astrocytes in vanishing white matter. Axons and myelin were analyzed using electron microscopy and immunohistochemistry on Eif2b4 and Eif2b5 single- and double-mutant mice and patient brain tissue. In addition, astrocyte-forebrain co-culture studies were performed. In the corpus callosum of Eif2b5- mutant mice, myelin sheath thickness, axonal diameter, and G-ratio developed normally up to 4 months. At 7 months, however, axons had become thinner, while in control mice axonal diameters had increased further. Myelin sheath thickness remained close to normal, resulting in an abnormally low G-ratio in Eif2b5- mutant mice. In more severely affected Eif2b4-Eif2b5 double-mutants, similar abnormalities were already present at 4 months, while in milder affected Eif2b4 mutants, few abnormalities were observed at 7 months. Additionally, from 2 months onward an increased percentage of thin, unmyelinated axons and increased axonal density were present in Eif2b5 -mutant mice. Co-cultures showed that Eif2b5 mutant astrocytes induced increased axonal density, also in control forebrain tissue, and that control astrocytes induced normal axonal density, also in mutant forebrain tissue. In vanishing white matter patient brains, axons and myelin sheaths were thinner than normal in moderately and severely affected white matter. In mutant mice and patients, signs of axonal transport defects and cytoskeletal abnormalities were minimal. In vanishing white matter, axons are initially normal and atrophy later. Astrocytes are central in this process. If therapy becomes available, axonal pathology may be prevented with early intervention.

Abnormal morphology of the penis in male rats exposed neonatally to diethylstilbestrol is associated with altered profile of estrogen receptor-alpha protein, but not of androgen receptor protein: a developmental and immunocytochemical study.

PubMed

Goyal, H O; Braden, T D; Williams, C S; Dalvi, P; Mansour, M M; Mansour, M; Williams, J W; Bartol, F F; Wiley, A A; Birch, L; Prins, G S

2004-05-01

Objectives of the study were to determine developmental changes in morphology and expression of androgen receptor (AR) and estrogen receptor (ER)alpha in the body of the rat penis exposed neonatally to diethylstilbestrol (DES). Male pups received DES at a dose of 10 microg per rat on alternate days from Postnatal Day 2 to Postnatal Day 12. Controls received olive oil vehicle only. Tissue samples were collected on Days 18 (prepuberty), 41 (puberty), and 120 (adult) of age. DES-induced abnormalities were evident at 18 days of age and included smaller, lighter, and thinner penis, loss of cavernous spaces and associated smooth muscle cells, and increased deposition of fat cells in the corpora cavernosa penis. Fat cells virtually filled the entire area of the corpora cavernosa at puberty and adulthood. Plasma testosterone (T) was reduced to an undetectable level, while LH was unaltered in all treated groups. AR-positive cells were ubiquitous and their profile (incidence and staining intensity) did not differ between control and treated rats of the respective age groups. Conversely, ERalpha-positive cells were limited to the stroma of corpus spongiosus in all age groups of both control and treated rats, but the expression in treated rats at 18 days was up-regulated in stromal cells of corpora cavernosa, coincident with the presence of morphological abnormalities. Hence, this study reports for the first time DES-induced developmental, morphological abnormalities in the body of the penis and suggests that these abnormalities may have resulted from decreased T and/or overexpression of ERalpha.

Progression from isolated growth hormone deficiency to combined pituitary hormone deficiency.

PubMed

Cerbone, Manuela; Dattani, Mehul T

2017-12-01

Growth hormone deficiency (GHD) can present at any time of life from the neonatal period to adulthood, as a result of congenital or acquired insults. It can present as an isolated problem (IGHD) or in combination with other pituitary hormone deficiencies (CPHD). Pituitary deficits can evolve at any time from GHD diagnosis. The number, severity and timing of occurrence of additional endocrinopathies are highly variable. The risk of progression from IGHD to CPHD in children varies depending on the etiology (idiopathic vs organic). The highest risk is displayed by children with abnormalities in the Hypothalamo-Pituitary (H-P) region. Heterogeneous data have been reported on the type and timing of onset of additional pituitary hormone deficits, with TSH deficiency being most frequent and Diabetes Insipidus the least frequent additional deficit in the majority, but not all, of the studies. ACTH deficiency may gradually evolve at any time during follow-up in children or adults with childhood onset IGHD, particularly (but not only) in presence of H-P abnormalities and/or TSH deficiency. Hence there is a need in these patients for lifelong monitoring for ACTH deficiency. GH treatment unmasks central hypothyroidism mainly in patients with organic GHD, but all patients starting GH should have their thyroid function monitored closely. Main risk factors for development of CPHD include organic etiology, H-P abnormalities (in particular pituitary stalk abnormalities, empty sella and ectopic posterior pituitary), midline brain (corpus callosum) and optic nerves abnormalities, genetic defects and longer duration of follow-up. The current available evidence supports longstanding recommendations for the need, in all patients diagnosed with IGHD, of a careful and indefinite follow-up for additional pituitary hormone deficiencies. Copyright © 2017 Elsevier Ltd. All rights reserved.

Corpus-based Customization for an Ontology

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

2010-09-14

CCAT scans a corpus of text for terms, and computes lexical similarity between corpus terms and taxonomy terms. Based on a set of metrics and a learning algorithm, the system inserts corpus terms into the taxonomy. Conversely, terms from the taxonomy are disambiguated based on the text in the corpus. Unused terms are discarded, and infrequently used senses of terms are collapsed to make the taxonomy more manageable.

Building a comprehensive syntactic and semantic corpus of Chinese clinical texts.

PubMed

He, Bin; Dong, Bin; Guan, Yi; Yang, Jinfeng; Jiang, Zhipeng; Yu, Qiubin; Cheng, Jianyi; Qu, Chunyan

2017-05-01

To build a comprehensive corpus covering syntactic and semantic annotations of Chinese clinical texts with corresponding annotation guidelines and methods as well as to develop tools trained on the annotated corpus, which supplies baselines for research on Chinese texts in the clinical domain. An iterative annotation method was proposed to train annotators and to develop annotation guidelines. Then, by using annotation quality assurance measures, a comprehensive corpus was built, containing annotations of part-of-speech (POS) tags, syntactic tags, entities, assertions, and relations. Inter-annotator agreement (IAA) was calculated to evaluate the annotation quality and a Chinese clinical text processing and information extraction system (CCTPIES) was developed based on our annotated corpus. The syntactic corpus consists of 138 Chinese clinical documents with 47,426 tokens and 2612 full parsing trees, while the semantic corpus includes 992 documents that annotated 39,511 entities with their assertions and 7693 relations. IAA evaluation shows that this comprehensive corpus is of good quality, and the system modules are effective. The annotated corpus makes a considerable contribution to natural language processing (NLP) research into Chinese texts in the clinical domain. However, this corpus has a number of limitations. Some additional types of clinical text should be introduced to improve corpus coverage and active learning methods should be utilized to promote annotation efficiency. In this study, several annotation guidelines and an annotation method for Chinese clinical texts were proposed, and a comprehensive corpus with its NLP modules were constructed, providing a foundation for further study of applying NLP techniques to Chinese texts in the clinical domain. Copyright © 2017. Published by Elsevier Inc.

Genetic and neurodevelopmental influences in autistic disorder.

PubMed

Nicolson, Rob; Szatmari, Peter

2003-09-01

In the past, autism was considered to be largely psychogenic. However, research in the last 2 decades indicates that autism is largely caused by genetic factors that lead to abnormal brain development. This article reviews research into the genetic and neurodevelopmental factors underlying autism. We review the findings from genetic and brain-imaging studies of autism over the past 15 years and synthesize these findings as a guide for future research. Genome scans and association studies have suggested potential genomic regions and genes, respectively, that may be involved in the etiology of autism, and there have been some replications of these results. Similarly, the findings that brain volume is exaggerated in autism and corpus callosum size is reduced have also been independently replicated. Unfortunately, studies of other subcortical structures remain inconclusive or contradictory. Overwhelming evidence now supports a neurobiological basis for autism. However, further refinements will be needed to guide future studies, particularly to identify the most informative phenotypes to investigate. Additionally, studies examining the role of genetic factors in the brain abnormalities underlying autism will likely lead to further findings that will enhance our understanding of autism's causes.

Neuroimaging evidence of gray and white matter damage and clinical correlates in progressive supranuclear palsy.

PubMed

Piattella, Maria Cristina; Upadhyay, N; Bologna, M; Sbardella, E; Tona, F; Formica, A; Petsas, N; Berardelli, A; Pantano, P

2015-08-01

To evaluate gray matter (GM) and white matter (WM) abnormalities and their clinical correlates in patients with progressive supranuclear palsy (PSP). Sixteen PSP patients and sixteen age-matched healthy subjects underwent a clinical evaluation and multimodal magnetic resonance imaging, including three-dimensional T1-weighted imaging and diffusion tensor imaging (DTI). Volumetric and DTI analyses were computed using SPM and FSL tools. PSP patients showed GM volume decrease, involving the frontal cortex, putamen, pallidum, thalamus and accumbens nucleus, cerebellum, and brainstem. Additionally, they had widespread changes in WM bundles, mainly affecting cerebellar peduncles, thalamic radiations, corticospinal tracts, corpus callosum, and longitudinal fasciculi. GM volumes did not correlate with WM abnormalities. DTI indices of WM damage, but not GM volumes, correlated with clinical scores of disease severity and cognitive impairment. The neurodegenerative changes that occur in PSP involve both GM and WM structures and develop concurrently though independently. WM damage in PSP correlates with clinical scores of disease severity and cognitive impairment, thus providing further insight into the pathophysiology of the disease.

Ocular dermoid in Pai Syndrome: A review.

PubMed

Tormey, Peter; Bilic Cace, Iva; Boyle, Michael A

2017-04-01

Pai Syndrome is a rare congenital malformation syndrome of unknown cause with hypertelorism, midline cleft lip, nasal and facial polyps, ocular anomalies and the presence of distinctive lipomas adjacent to the corpus callosum. Herein, we present an infant girl with Pai Syndrome diagnosed in the first week of life with typical facial findings and associated pericallosal lipoma identified on cranial ultrasound and brain MRI. These typical features identified included median cleft of the upper lip (in her case as a forme fruste) with a cleft alveolus and a mid-anterior alveolar process congenital polyp. In addition to these findings there was mild hypertelorism and an ocular abnormality on the right eye. An ophthalmology assessment on day 5 identified the ocular lesion as a limbal dermoid. Several ocular anomalies have been reported in association with Pai Syndrome, however, dermoids have not been frequently described in this Syndrome and not before in a limbal location. Increasing identification of previously unreported ocular abnormalities in Pai Syndrome may improve diagnosis and may prove useful in future work attempting to elucidate the aetiology of this rare syndrome. Copyright © 2017. Published by Elsevier Masson SAS.

Trial of Cisplatin Plus Radiation Followed by Carbo and Taxol Vs. Sandwich Therapy of Carbo and Taxol Followed Radiation Then Further Carbo and Taxol

ClinicalTrials.gov

2017-10-30

Endometrial Clear Cell Adenocarcinoma; Endometrial Serous Adenocarcinoma; Stage IIIA Uterine Corpus Cancer; Stage IIIB Uterine Corpus Cancer; Stage IIIC Uterine Corpus Cancer; Stage IVA Uterine Corpus Cancer

Carevive Survivor Care Planning System in Improving Quality of Life in Breast Cancer Survivors

ClinicalTrials.gov

2018-02-20

Stage I Breast Cancer; Stage I Cervical Cancer; Stage I Ovarian Cancer; Stage I Uterine Corpus Cancer; Stage IA Breast Cancer; Stage IA Cervical Cancer; Stage IA Ovarian Cancer; Stage IA Uterine Corpus Cancer; Stage IB Breast Cancer; Stage IB Cervical Cancer; Stage IB Ovarian Cancer; Stage IB Uterine Corpus Cancer; Stage IC Ovarian Cancer; Stage II Breast Cancer; Stage II Cervical Cancer; Stage II Ovarian Cancer; Stage II Uterine Corpus Cancer; Stage IIA Breast Cancer; Stage IIA Cervical Cancer; Stage IIA Ovarian Cancer; Stage IIB Breast Cancer; Stage IIB Cervical Cancer; Stage IIB Ovarian Cancer; Stage IIC Ovarian Cancer; Stage III Breast Cancer; Stage III Cervical Cancer; Stage III Ovarian Cancer; Stage III Uterine Corpus Cancer; Stage IIIA Breast Cancer; Stage IIIA Cervical Cancer; Stage IIIA Ovarian Cancer; Stage IIIA Uterine Corpus Cancer; Stage IIIB Breast Cancer; Stage IIIB Cervical Cancer; Stage IIIB Ovarian Cancer; Stage IIIB Uterine Corpus Cancer; Stage IIIC Breast Cancer; Stage IIIC Ovarian Cancer; Stage IIIC Uterine Corpus Cancer

Developing an International Corpus of Creative English

ERIC Educational Resources Information Center

Hassall, Peter John

2006-01-01

This paper proposes an International Corpus of Creative English (ICCE) as a worldwide corpus particularly suitable for implementation in countries which have tertiary institutions with well-defined populations of students possessing similar cultural and/or linguistic backgrounds. The ICCE is contextualized as a world Englishes corpus with…

Imaging of pediatric pituitary endocrinopathies

PubMed Central

Chaudhary, Vikas; Bano, Shahina

2012-01-01

Accurate investigation of the hypothalamic-pituitary area is required in pediatric patients for diagnosis of endocrine-related disorders. These disorders include hypopituitarism, growth failure, diencephalic syndrome, delayed puberty, precocious puberty, diabetes insipidus, syndrome of inappropriate antidiuretic hormone (SIADH) secretion, and hyperpituitarism. Magnetic resonance imaging (MRI) is the modality of choice to visualize hypothalamic-pituitary axis and associated endocrinopathies. Neuroimaging can be normal or disclose abnormalities related to pituitary-hypothalamic axis like (i) congenital and developmental malformations; (ii) tumors; (iii) cystic lesions; and (iv) infectious and inflammatory conditions. Classical midline anomalies like septo-optic dysplasias or corpus callosum agenesis are commonly associated with pituitary endocrinopathies and also need careful evaluation. In this radiological review, we will discuss neuroendocrine disorders related to hypothalamic pituitary-axis. PMID:23087850

Common pathophysiological mechanisms involved in luteal phase deficiency and polycystic ovary syndrome. Impact on fertility.

PubMed

Boutzios, Georgios; Karalaki, Maria; Zapanti, Evangelia

2013-04-01

Luteal phase deficiency (LPD) is a consequence of the corpus luteum (CL) inability to produce and preserve adequate levels of progesterone. This is clinically manifested by short menstrual cycles and infertility. Abnormal follicular development, defects in neo-angiogenesis or inadequate steroidogenesis in the lutein cells of the CL have been implicated in CL dysfunction and LPD. LPD and polycystic ovary syndrome (PCOS) are independent disorders sharing common pathophysiological profiles. Factors such as hyperinsulinemia, AMH excess, and defects in angiogenesis of CL are at the origin of both LPD and PCOS. In PCOS ovulatory cycles, infertility could result from dysfunctional CL. The aim of this review was to investigate common mechanisms of infertility in CL dysfunction and PCOS.

The Hebrew CHILDES corpus: transcription and morphological analysis

PubMed Central

Albert, Aviad; MacWhinney, Brian; Nir, Bracha

2014-01-01

We present a corpus of transcribed spoken Hebrew that reflects spoken interactions between children and adults. The corpus is an integral part of the CHILDES database, which distributes similar corpora for over 25 languages. We introduce a dedicated transcription scheme for the spoken Hebrew data that is sensitive to both the phonology and the standard orthography of the language. We also introduce a morphological analyzer that was specifically developed for this corpus. The analyzer adequately covers the entire corpus, producing detailed correct analyses for all tokens. Evaluation on a new corpus reveals high coverage as well. Finally, we describe a morphological disambiguation module that selects the correct analysis of each token in context. The result is a high-quality morphologically-annotated CHILDES corpus of Hebrew, along with a set of tools that can be applied to new corpora. PMID:25419199

Towards a Computable Data Corpus of Temporal Correlations between Drug Administration and Lab Value Changes

PubMed Central

Newe, Axel; Wimmer, Stefan; Neubert, Antje; Becker, Linda; Prokosch, Hans-Ulrich; Ganslandt, Thomas

2015-01-01

Background The analysis of electronic health records for an automated detection of adverse drug reactions is an approach to solve the problems that arise from traditional methods like spontaneous reporting or manual chart review. Algorithms addressing this task should be modeled on the criteria for a standardized case causality assessment defined by the World Health Organization. One of these criteria is the temporal relationship between drug intake and the occurrence of a reaction or a laboratory test abnormality. Appropriate data that would allow for developing or validating related algorithms is not publicly available, though. Methods In order to provide such data, retrospective routine data of drug administrations and temporally corresponding laboratory observations from a university clinic were extracted, transformed and evaluated by experts in terms of a reasonable time relationship between drug administration and lab value alteration. Result The result is a data corpus of 400 episodes of normalized laboratory parameter values in temporal context with drug administrations. Each episode has been manually classified whether it contains data that might indicate a temporal correlation between the drug administration and the change of the lab value course, whether such a change is not observable or whether a decision between those two options is not possible due to the data. In addition, each episode has been assigned a concordance value which indicates how difficult it is to assess. This is the first open data corpus of a computable ground truth of temporal correlations between drug administration and lab value alterations. Discussion The main purpose of this data corpus is the provision of data for further research and the provision of a ground truth which allows for comparing the outcome of other assessments of this data with the outcome of assessments made by human experts. It can serve as a contribution towards systematic, computerized ADR detection in retrospective data. With this lab value curve data as a basis, algorithms for detecting temporal relationships can be developed, and with the classification made by human experts, these algorithms can immediately be validated. Due to the normalization of the lab value data, it allows for a generic approach rather than for specific or solitary drug/lab value combinations. PMID:26301507

Prenatal and Neonatal Brain Structure and White Matter Maturation in Children at High Risk for Schizophrenia

PubMed Central

Gilmore, John H.; Kang, Chaeryon; Evans, Dianne D.; Wolfe, Honor M.; Smith, J. Keith; Lieberman, Jeffrey A.; Lin, Weili; Hamer, Robert M.; Styner, Martin; Gerig, Guido

2011-01-01

Objective Schizophrenia is a neurodevelopmental disorder associated with abnormalities of brain structure and white matter, although little is known about when these abnormalities arise. This study was conducted to identify structural brain abnormalities in the prenatal and neonatal periods associated with genetic risk for schizophrenia. Method Prenatal ultrasound scans and neonatal structural magnetic resonance imaging (MRI) and diffusion tensor imaging were prospectively obtained in the offspring of mothers with schizophrenia or schizoaffective disorder (N=26) and matched comparison mothers without psychiatric illness (N=26). Comparisons were made for prenatal lateral ventricle width and head circumference, for neonatal intracranial, CSF, gray matter, white matter, and lateral ventricle volumes, and for neonatal diffusion properties of the genu and splenium of the corpus callosum and corticospinal tracts. Results Relative to the matched comparison subjects, the offspring of mothers with schizophrenia did not differ in prenatal lateral ventricle width or head circumference. Overall, the high-risk neonates had nonsignificantly larger intracranial, CSF, and lateral ventricle volumes. Subgroup analysis revealed that male high-risk infants had significantly larger intracranial, CSF, total gray matter, and lateral ventricle volumes; the female high-risk neonates were similar to the female comparison subjects. There were no group differences in white matter diffusion tensor properties. Conclusions Male neonates at genetic risk for schizophrenia had several larger than normal brain volumes, while females did not. To the authors' knowledge, this study provides the first evidence, in the context of its limitations, that early neonatal brain development may be abnormal in males at genetic risk for schizophrenia. PMID:20516153

75 FR 43886 - Proposed Amendment of Class E Airspace; Corpus Christi, TX

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-27

...-0404; Airspace Docket No. 10-ASW-7] Proposed Amendment of Class E Airspace; Corpus Christi, TX AGENCY... action proposes to amend Class E airspace in the Corpus Christi, TX area. Additional controlled airspace is necessary to accommodate new Standard Instrument Approach Procedures (SIAPs) at Corpus Christi...

75 FR 31677 - Amendment of Class E Airspace; Corpus Christi, TX

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-04

...-0089; Airspace Docket No. 10-ASW-1] Amendment of Class E Airspace; Corpus Christi, TX AGENCY: Federal... the Corpus Christi, TX area. Additional controlled airspace is necessary to accommodate new Standard... E airspace for the Corpus Christi, TX area, reconfiguring controlled airspace at Aransas County...

75 FR 66301 - Amendment of Class E Airspace; Corpus Christi, TX

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-28

... the Corpus Christi, TX, area. Additional controlled airspace is necessary to accommodate new Standard Instrument Approach Procedures (SIAP) at Corpus Christi International Airport, Corpus Christi, TX. The FAA is taking this action to enhance the safety and management of Instrument Flight Rule (IFR) operations at the...

VSV-hIFNbeta-NIS in Treating Patients With Stage IV or Recurrent Endometrial Cancer

ClinicalTrials.gov

2018-05-09

Endometrial Clear Cell Adenocarcinoma; Endometrial Mixed Adenocarcinoma; Endometrial Serous Adenocarcinoma; Endometrial Undifferentiated Carcinoma; Metastatic Endometrioid Adenocarcinoma; Ovarian Endometrioid Adenocarcinoma; Recurrent Endometrial Serous Adenocarcinoma; Recurrent Uterine Corpus Carcinoma; Stage IV Uterine Corpus Cancer; Stage IVA Uterine Corpus Cancer; Stage IVB Uterine Corpus Cancer

The Effect of Corpus-Based Instruction on Pragmatic Routines

ERIC Educational Resources Information Center

Bardovi-Harlig, Kathleen; Mossman, Sabrina; Su, Yunwen

2017-01-01

This study compares the effect of using corpus-based materials and activities for the instruction of pragmatic routines under two conditions: implementing direct corpus searches by learners during classroom instruction and working with teacher-developed corpus-based materials. The outcome is compared to a repeated-test control group. Pragmatic…

Abnormal brain magnetic resonance imaging in two patients with Smith-Magenis syndrome.

PubMed

Maya, Idit; Vinkler, Chana; Konen, Osnat; Kornreich, Liora; Steinberg, Tamar; Yeshaya, Josepha; Latarowski, Victoria; Shohat, Mordechai; Lev, Dorit; Baris, Hagit N

2014-08-01

Smith-Magenis syndrome (SMS) is a clinically recognizable contiguous gene syndrome ascribed to an interstitial deletion in chromosome 17p11.2. Seventy percent of SMS patients have a common deletion interval spanning 3.5 megabases (Mb). Clinical features of SMS include characteristic mild dysmorphic features, ocular anomalies, short stature, brachydactyly, and hypotonia. SMS patients have a unique neurobehavioral phenotype that includes intellectual disability, self-injurious behavior and severe sleep disturbance. Little has been reported in the medical literature about anatomical brain anomalies in patients with SMS. Here we describe two patients with SMS caused by the common deletion in 17p11.2 diagnosed using chromosomal microarray (CMA). Both patients had a typical clinical presentation and abnormal brain magnetic resonance imaging (MRI) findings. One patient had subependymal periventricular gray matter heterotopia, and the second had a thin corpus callosum, a thin brain stem and hypoplasia of the cerebellar vermis. This report discusses the possible abnormal MRI images in SMS and reviews the literature on brain malformations in SMS. Finally, although structural brain malformations in SMS patients are not a common feature, we suggest baseline routine brain imaging in patients with SMS in particular, and in patients with chromosomal microdeletion/microduplication syndromes in general. Structural brain malformations in these patients may affect the decision-making process regarding their management. © 2014 Wiley Periodicals, Inc.

White matter abnormalities of microstructure and physiological noise in schizophrenia.

PubMed

Cheng, Hu; Newman, Sharlene D; Kent, Jerillyn S; Bolbecker, Amanda; Klaunig, Mallory J; O'Donnell, Brian F; Puce, Aina; Hetrick, William P

2015-12-01

White matter abnormalities in schizophrenia have been revealed by many imaging techniques and analysis methods. One of the findings by diffusion tensor imaging is a decrease in fractional anisotropy (FA), which is an indicator of white matter integrity. On the other hand, elevation of metabolic rate in white matter was observed from positron emission tomography (PET) studies. In this report, we aim to compare the two structural and functional effects on the same subjects. Our comparison is based on the hypothesis that signal fluctuation in white matter is associated with white matter functional activity. We examined the variance of the signal in resting state fMRI and found significant differences between individuals with schizophrenia and non-psychiatric controls specifically in white matter tissue. Controls showed higher temporal signal-to-noise ratios clustered in regions including temporal, frontal, and parietal lobes, cerebellum, corpus callosum, superior longitudinal fasciculus, and other major white matter tracts. These regions with higher temporal signal-to-noise ratio agree well with those showing higher metabolic activity reported by studies using PET. The results suggest that individuals with schizophrenia tend to have higher functional activity in white matter in certain brain regions relative to healthy controls. Despite some overlaps, the distinct regions for physiological noise are different from those for FA derived from diffusion tensor imaging, and therefore provide a unique angle to explore potential mechanisms to white matter abnormality.

Relationship between characteristics on magnetic resonance imaging and motor outcomes in children with cerebral palsy and white matter injury.

PubMed

Reid, Susan M; Ditchfield, Michael R; Bracken, Jenny; Reddihough, Dinah S

2015-01-01

In a population cohort of children with white matter injury (WMI) and cerebral palsy (CP), we aimed to describe the magnetic resonance imaging (MRI) characteristics, identify key structure-function relationships, and classify the severity of WMI in a clinically relevant way. Stratified on MRI laterality/symmetry, variables indicating the extent and location of cerebral abnormalities for 272 children with CP and WMI on chronic-phase MRI were related to gross motor function and motor topography using univariable and multivariable approaches. We found that symmetrical involvement, severe WM loss in the hemispheres and corpus callosum, and cerebellar involvement were the strongest predictors of poor gross motor function, but the final model explained only a small proportion of the variability. Bilateral, extensive WM loss was more likely to result in quadriplegia, whereas volume loss in the posterior-mid WM more frequently resulted in diplegia. The extent and location of MRI abnormalities differed according to laterality/symmetry; asymmetry was associated with less extensive hemispheric involvement than symmetrical WMI, and unilateral lesions were more focal and located more anteriorly. In summary, laterality/symmetry of WMI, possibly reflecting different pathogenic mechanisms, together with extent of WM loss and cerebellar abnormality predicted gross motor function in CP, but to a limited extent. Copyright © 2015 Elsevier Ltd. All rights reserved.

Prevalence of prenatal brain abnormalities in fetuses with congenital heart disease: a systematic review.

PubMed

Khalil, A; Bennet, S; Thilaganathan, B; Paladini, D; Griffiths, P; Carvalho, J S

2016-09-01

Studies have shown an association between congenital heart defects (CHDs) and postnatal brain abnormalities and neurodevelopmental delay. Recent evidence suggests that some of these brain abnormalities are present before birth. The primary aim of this study was to perform a systematic review to quantify the prevalence of prenatal brain abnormalities in fetuses with CHDs. MEDLINE, EMBASE and The Cochrane Library were searched electronically. Reference lists within each article were hand-searched for additional reports. The outcomes observed included structural brain abnormalities (on magnetic resonance imaging (MRI)) and changes in brain volume (on MRI, three-dimensional (3D) volumetric MRI, 3D ultrasound and phase-contrast MRI), brain metabolism or maturation (on magnetic resonance spectroscopy and phase-contrast MRI) and brain blood flow (on Doppler ultrasound, phase-contrast MRI and 3D power Doppler ultrasound) in fetuses with CHDs. Cohort and case-control studies were included and cases of chromosomal or genetic abnormalities, case reports and editorials were excluded. Proportion meta-analysis was used for analysis. Between-study heterogeneity was assessed using the I(2) test. The search yielded 1943 citations, and 20 studies (n = 1175 cases) were included in the review. Three studies reported data on structural brain abnormalities, while data on altered brain volume, metabolism and blood flow were reported in seven, three and 14 studies, respectively. The three studies (221 cases) reporting on structural brain abnormalities were suitable for inclusion in a meta-analysis. The prevalence of prenatal structural brain abnormalities in fetuses with CHD was 28% (95% CI, 18-40%), with a similar prevalence (25% (95% CI, 14-39%)) when tetralogy of Fallot was considered alone. These abnormalities included ventriculomegaly (most common), agenesis of the corpus callosum, ventricular bleeding, increased extra-axial space, vermian hypoplasia, white-matter abnormalities and delayed brain development. Fetuses with CHD were more likely than those without CHD to have reduced brain volume, delay in brain maturation and altered brain circulation, most commonly in the form of reduced middle cerebral artery pulsatility index and cerebroplacental ratio. These changes were usually evident in the third trimester, but some studies reported them from as early as the second trimester. In the absence of known major aneuploidy or genetic syndromes, fetuses with CHD are at increased risk of brain abnormalities, which are discernible prenatally. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Foot and ankle problems in Muay Thai kickboxers.

PubMed

Vaseenon, Tanawat; Intharasompan, Piyapong; Wattanarojanapom, Thongaek; Theeraamphon, Nipon; Auephanviriyakul, Sansanee; Phisitkul, Phinit

2015-01-01

Muay Thai kickboxing is a common sport that uses the foot and ankle in fighting. Muay Thai kickboxing trainees usually receive training in Thailand Foot and ankle problems in this group ofpeople who usually train barefoot remain unexplored To evaluate the prevalence of common foot and ankle problems in Muay Thai kick boxers. The present study is a cross-sectional survey of Muay Thai kick boxers practicing in northern Thailand. Interviews were conducted and foot and ankle examinations were evaluated Foot morphology was examined using a Harris mat footprint. One hundred and twenty-three Muay Thai kickbox ersinnine training gyms were included in this study. Common foot and ankle problems found in the Muay Thai kick boxers were callosity (59%), gastrocnemius contracture (57%), toe deformities (49.3%), wounds (10%) and heel pain (9%). Callosity was most commonly found on the forefoot (77.5%), on the plantar first metatarsal (55.3%) and on the big toe (33.3%). An association was found between a tight heel cord and a history of foot injury with prolonged periods of weekly training. Toe deformities such as hallux rigidus (37.6%) were also associated with prolonged periods of training (p = 0.001). No correlation was found between type of foot arch and foot and ankle problems. Plantar forefoot callosities and wounds as well as toe deformities including tight heel cords are some of the foot and ankle problems commonly found in Muay Thai kick boxers. They are associated with prolonged periods of barefoot training. The unique pattern of training and of the kicks in Muay Thai might be a path mechanism, leading to the development of foot and ankle problems.

Effect of lead (Pb) on the systemic movement of RNA viruses in tobacco (Nicotiana tabacum var. Turkish).

PubMed

Alkhatib, Rami; Creamer, Rebecca; Lartey, Robert T; Ghoshroy, Soumitra

2011-08-01

Effect of various lead (Pb) concentrations on the systemic movement of RNA viruses was examined in tobacco plants. Prior to inoculation, plants were grown hydroponically for 6 days in Hoagland's solution supplemented with five concentrations of lead nitrate [Pb(NO(3))(2)]: 0.0 (control), 10, 15, 50, and 100 μM. Four different RNA viruses with different cell-to-cell movement mechanisms were used. Two weeks after inoculation lower and upper leaves of each treatment were harvested and examined for the presence of viral coat protein. In plants inoculated with Tobacco mosaic virus, Potato virus X, and Tobacco etch virus, TEM images and western blot assays confirmed the presence of viral coat proteins in the upper leaves of all lead treatments. However, in plants inoculated with Turnip vein-clearing virus (TVCV), no signs of viral particles were detected in the upper leaves of plants treated with 10 μM or 15 μM lead nitrate. In contrast, plants treated with high concentrations of lead nitrate (50 μM or 100 μM) showed viral particles in their upper leaves. In plants treated with 10 μM or 15 μM lead nitrate, callose accumulation was the same as in control plants. This suggests that non-toxic concentrations of lead nitrate may trigger the production of putative cellular factors in addition to callose that interfere with the TVCV systemic movement. In contrast, plants treated with 100 μM lead nitrate showed less callose as compared to control plants, facilitating the systemic movement of TVCV.

White matter fiber compromise contributes differentially to attention and emotion processing impairment in alcoholism, HIV-infection, and their comorbidity.

PubMed

Schulte, T; Müller-Oehring, E M; Sullivan, E V; Pfefferbaum, A

2012-10-01

Alcoholism (ALC) and HIV-1 infection (HIV) each affects emotional and attentional processes and integrity of brain white matter fibers likely contributing to functional compromise. The highly prevalent ALC+HIV comorbidity may exacerbate compromise. We used diffusion tensor imaging (DTI) and an emotional Stroop Match-to-Sample task in 19 ALC, 16 HIV, 15 ALC+HIV, and 15 control participants to investigate whether disruption of fiber system integrity accounts for compromised attentional and emotional processing. The task required matching a cue color to that of an emotional word with faces appearing between the color cue and the Stroop word in half of the trials. Nonmatched cue-word color pairs assessed selective attention, and face-word pairs assessed emotion. Relative to controls, DTI-based fiber tracking revealed lower inferior longitudinal fasciculus (ilf) integrity in HIV and ALC+HIV and lower uncinate fasciculus (uf) integrity in all three patient groups. Controls exhibited Stroop effects to positive face-word emotion, and greater interference was related to greater callosal, cingulum and ilf integrity. By contrast, HIV showed greater interference from negative Stroop words during color-nonmatch trials, correlating with greater uf compromise. For face trials, ALC and ALC+HIV showed greater Stroop-word interference, correlating with lower cingulate and callosal integrity. Thus, in HIV, conflict resolution was diminished when challenging conditions usurped resources needed to manage interference from negative emotion and to disengage attention from wrongly cued colors (nonmatch). In ALC and ALC+HIV, poorer callosal integrity was related to enhanced emotional interference suggesting curtailed interhemispheric exchange needed between preferentially right-hemispheric emotion and left-hemispheric Stroop-word functions. Copyright © 2012 Elsevier Ltd. All rights reserved.

Effects of exogenous plant growth regulator abscisic acid-induced resistance in rice on the expression of vitellogenin mRNA in Nilaparvata lugens (Hemiptera: Delphacidae) adult females.

PubMed

Liu, Jing-Lan; Chen, Xiao; Zhang, Hong-Mei; Yang, Xia; Wong, Andrew

2014-01-01

Recent study showed that exogenous abscisic acid (ABA) acts as a regulator of plant resistance. This study investigated average injury scale and callose contents of rice, and vitellogenin (Nlvg) mRNA expression in Nilaparvata lugens (Stål) (Hemiptera: Delphacidae) adult females after third instar nymphs fed on exogenous ABA-treated susceptible [Taichung Native one (TN1)] and moderately resistant (IR42) rice cultivars. The results showed that exogenous ABA significantly decreased average injury scale of rice and Nlvg mRNA expression in N. lugens adults compared with the control (without ABA spraying). Nlvg mRNA expression in N. lugens adults decreased significantly after third instar nymphs fed on ABA-treated (5, 20, and 40 mg/liter) TN1 for 1 and 2 d, and for IR42, after fed on ABA-treated (20 and 40 mg/liter) rice plants for 1 d and after fed on ABA-treated (5, 20, and 40 mg/liter) rice for 2 d decreased significantly. The callose contents showed no significant change for TN1, while for IR42, significantly increased in roots and sheathes after N. lugens infestation under ABA treatments (20 and 40 mg/liter) compared with the control. The decrease of Nlvg mRNA expression may be partially attributed to the increase of callose content of plants. The results provide a profile for concerning the effects of ABA-induced rice plants' defenses on phloem-feeding insects. © The Author 2014. Published by Oxford University Press on behalf of the Entomological Society of America.

Surgery and Chemotherapy With or Without Chemotherapy After Surgery in Treating Patients With Ovarian, Fallopian Tube, Uterine, or Peritoneal Cancer

ClinicalTrials.gov

2018-04-26

Recurrent Uterine Corpus Cancer; Recurrent Fallopian Tube Cancer; Recurrent Ovarian Cancer; Recurrent Primary Peritoneal Cancer; Stage IIIA Uterine Corpus Cancer; Stage IIIA Fallopian Tube Cancer; Stage IIIA Ovarian Cancer; Stage IIIA Primary Peritoneal Cavity Cancer; Stage IIIB Uterine Corpus Cancer; Stage IIIB Fallopian Tube Cancer; Stage IIIB Ovarian Cancer; Stage IIIB Primary Peritoneal Cavity Cancer; Stage IIIC Uterine Corpus Cancer; Stage IIIC Fallopian Tube Cancer; Stage IIIC Ovarian Cancer; Stage IIIC Primary Peritoneal Cavity Cancer; Stage IV Fallopian Tube Cancer; Stage IV Ovarian Cancer; Stage IV Primary Peritoneal Cavity Cancer; Stage IVA Uterine Corpus Cancer; Stage IVB Uterine Corpus Cancer

Evaluating Corpus Literacy Training for Pre-Service Language Teachers: Six Case Studies

ERIC Educational Resources Information Center

Heather, Julian; Helt, Marie

2012-01-01

Corpus literacy is the ability to use corpora--large, principled databases of spoken and written language--for language analysis and instruction. While linguists have emphasized the importance of corpus training in teacher preparation programs, few studies have investigated the process of initiating teachers into corpus literacy with the result…

75 FR 13453 - Proposed Amendment of Class E Airspace; Corpus Christi, TX

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-22

...-0089; Airspace Docket No. 10-ASW-1] Proposed Amendment of Class E Airspace; Corpus Christi, TX AGENCY... action proposes to amend Class E airspace in the Corpus Christi, TX area. Additional controlled airspace... adding additional Class E airspace extending upward from 700 feet above the surface in the Corpus Christi...

Corpus-Based Research and Pedagogy in EAP: From Lexis to Genre

ERIC Educational Resources Information Center

Flowerdew, Lynne

2015-01-01

This plenary paper showcases current corpus-based research on written academic English, illustrating the tight links that exist between corpus research and pedagogic applications. I first explicate Sinclair's concept of the "lexical approach", which underpins much corpus research and pedagogy. I then discuss studies which focus on…

EFL Students' Perceptions of Corpus-Tools as Writing References

ERIC Educational Resources Information Center

Lai, Shu-Li

2015-01-01

A number of studies have suggested the potentials of corpus tools in vocabulary learning. However, there are still some concerns. Corpus tools might be too complicated to use; example sentences retrieved from corpus tools might be too difficult to understand; processing large number of sample sentences could be challenging and time-consuming;…

Adavosertib, External Beam Radiation Therapy, and Cisplatin in Treating Patients With Cervical, Vaginal, or Uterine Cancer

ClinicalTrials.gov

2018-06-06

Endometrioid Adenocarcinoma; Recurrent Cervical Carcinoma; Stage I Uterine Corpus Cancer AJCC v7; Stage I Vaginal Cancer AJCC v6 and v7; Stage IA Uterine Corpus Cancer AJCC v7; Stage IB Cervical Cancer AJCC v6 and v7; Stage IB Uterine Corpus Cancer AJCC v7; Stage IB2 Cervical Cancer AJCC v6 and v7; Stage II Cervical Cancer AJCC v7; Stage II Uterine Corpus Cancer AJCC v7; Stage II Vaginal Cancer AJCC v6 and v7; Stage IIA Cervical Cancer AJCC v7; Stage IIB Cervical Cancer AJCC v6 and v7; Stage III Cervical Cancer AJCC v6 and v7; Stage III Uterine Corpus Cancer AJCC v7; Stage III Vaginal Cancer AJCC v6 and v7; Stage IIIA Cervical Cancer AJCC v6 and v7; Stage IIIA Uterine Corpus Cancer AJCC v7; Stage IIIB Cervical Cancer AJCC v6 and v7; Stage IIIB Uterine Corpus Cancer AJCC v7; Stage IIIC Uterine Corpus Cancer AJCC v7

Midline cystic malformations of the brain: imaging diagnosis and classification based on embryologic analysis.

PubMed

Utsunomiya, Hidetsuna; Yamashita, Shinichi; Takano, Koichi; Ueda, Yukiyo; Fujii, Akira

2006-07-01

This article describes a classification and imaging diagnosis of intracranial midline cystic malformations based on neuroembryologic analysis. Midline cystic malformations are classified into two categories from an embryologic point of view. In one category, the cyst represents expansion of the roof plate of the brain vesicle, and in the other the cyst consists of extraaxial structures such as an arachnoid membrane or migrating ependymal cells. Infratentorial cysts, such as the Dandy-Walker cyst or Blake's pouch cyst, and supratentorial cysts, such as a communicating interhemispheric cyst with callosal agenesis or a dorsal cyst with holoprosencephaly, are included in the first category. Infratentorial arachnoid cavities, such as the arachnoid cyst, arachnoid pouch, and mega cisterna magna, are in the second category. Noncommunicating interhemispheric cysts, such as interhemispheric arachnoid cyst or ependymal cyst, with callosal agenesis are also in the second category. A careful review of embryologic development is essential for understanding these midline cysts and for making a more accurate radiologic diagnosis.

Corpus Linguistics and the Design of a Response Message

NASA Astrophysics Data System (ADS)

Atwell, E.

2002-01-01

Most research related to SETI, the Search for Extra-Terrestrial Intelligence, is focussed on techniques for detection of possible incoming signals from extra-terrestrial intelligent sources (e.g. Turnbull et al. 1999), and algorithms for analysis of these signals to identify intelligent language-like characteristics (e.g. Elliott and Atwell 1999, 2000). However, another issue for research and debate is the nature of our response, should a signal arrive and be detected. The design of potentially the most significant communicative act in history should not be decided solely by astrophysicists; the Corpus Linguistics research community has a contribution to make to what is essentially a Corpus design and implementation project. (Vakoch 1998) advocated that the message constructed to transmit to extraterrestrials should include a broad, representative collection of perspectives rather than a single viewpoint or genre; this should strike a chord with Corpus Linguists for whom a central principle is that a corpus must be "balanced" to be representative (Meyer 2001). One idea favoured by SETI researchers is to transmit an encyclopaedia summarising human knowledge, such as the Encyclopaedia Britannica, to give ET communicators an overview and "training set" key to analysis of subsequent messages. Furthermore, this should be sent in several versions in parallel: the text; page-images, to include illustrations left out of the text-file and perhaps some sort of abstract linguistic representation of the text, using a functional or logic language (Ollongren 1999, Freudenthal 1960). The idea of "enriching" the message corpus with annotations at several levels should also strike a chord with Corpus Linguists who have long known that Natural language exhibits highly complex multi-layering sequencing, structural and functional patterns, as difficult to model as sequences and structures found in more traditional physical and biological sciences. Some corpora have been annotated with several levels or layers of linguistic knowledge, for example the SEC corpus (Taylor and Knowles 1988), the ISLE corpus (Menzel et al. 2000). Tagged and parsed corpus can be used by corpus linguists as a testbed to guide their development of grammars (e.g. Souter and Atwell 1994); and they can be used to train Natural Language Learning or data-mining models of complex sequence data (e.g. Brill 1993, Hughes 1993, Atwell 1996). Corpus linguists have a range of standards and tools for design and annotation of representative corpus resources, and experience of which annotation types are more amenable to Natural Language Learning algorithms. An Advisory panel of corpus linguists could help design and implement an extended Multi-annotated Interstellar Corpus of English, incorporating ideas from Corpus Linguistics such as: - Augment the Encyclopaedia Britannica with a collection of samples representing the diversity of language in real use. - As an additional "key", transmit a dictionary aimed at language learners which has also been a rich source for NLP - Supply our ET communicators with several levels of linguistic annotation, to give them a richer training set for their - Add translations of the English text into other human languages: Humanity should not be represented by English alone, This calls for a large-scale corpus annotation project, requiring an Interstellar Corpus Advisory Panel, analogous to the BNC or MATE advisory panels, to include experts in English grammar and semantics, English language learning, computational Natural language Learning algorithms, and corpus design, implementation, annotation, standardisation, and analysis.

Microstructural changes to the brain of mice after methamphetamine exposure as identified with diffusion tensor imaging.

PubMed

McKenna, Benjamin S; Brown, Gregory G; Archibald, Sarah; Scadeng, Miriam; Bussell, Robert; Kesby, James P; Markou, Athina; Soontornniyomkij, Virawudh; Achim, Cristian; Semenova, Svetlana

2016-03-30

Methamphetamine (METH) is an addictive psychostimulant inducing neurotoxicity. Human magnetic resonance imaging and diffusion tensor imaging (DTI) of METH-dependent participants find various structural abnormities. Animal studies demonstrate immunohistochemical changes in multiple cellular pathways after METH exposure. Here, we characterized the long-term effects of METH on brain microstructure in mice exposed to an escalating METH binge regimen using in vivo DTI, a methodology directly translatable across species. Results revealed four patterns of differential fractional anisotropy (FA) and mean diffusivity (MD) response when comparing METH-exposed (n=14) to saline-treated mice (n=13). Compared to the saline group, METH-exposed mice demonstrated: 1) decreased FA with no change in MD [corpus callosum (posterior forceps), internal capsule (left), thalamus (medial aspects), midbrain], 2) increased MD with no change in FA [posterior isocortical regions, caudate-putamen, hypothalamus, cerebral peduncle, internal capsule (right)], 3) increased FA with decreased MD [frontal isocortex, corpus callosum (genu)], and 4) increased FA with no change or increased MD [hippocampi, amygdala, lateral thalamus]. MD was negatively associated with calbindin-1 in hippocampi and positively with dopamine transporter in caudate-putamen. These findings highlight distributed and differential METH effects within the brain suggesting several distinct mechanisms. Such mechanisms likely change brain tissue differentially dependent upon neural location. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Has Corpus-Based Instruction Reached a Tipping Point? Practical Applications and Pointers for Teachers

ERIC Educational Resources Information Center

Huang, Li-Shih

2017-01-01

This article provides an easy introduction into corpus-based instruction by explaining what the approach entails. It also presents key terms and discusses key theoretical concepts drawn from the literature; from these, practical applications and pointers are offered for those practitioners wishing to use corpus data or implement corpus-based…

Motivating College Students' Learning English for Specific Purposes Courses through Corpus Building

ERIC Educational Resources Information Center

Wu, Lin-Fang

2014-01-01

This study was conducted to determine how to motivate technical college students to learn English for specific purposes (ESP) courses through corpus building and enhance their language proficiency during the coursework for their majors. This study explores corpus building skills, how to simplify ESP courses by corpus building for English as second…

Corpus Linguistics and Language Testing: Navigating Uncharted Waters

ERIC Educational Resources Information Center

Egbert, Jesse

2017-01-01

The use of corpora and corpus linguistic methods in language testing research is increasing at an accelerated pace. The growing body of language testing research that uses corpus linguistic data is a testament to their utility in test development and validation. Although there are many reasons to be optimistic about the future of using corpus data…

33 CFR 165.808 - Corpus Christi Ship Channel, Corpus Christi, TX, safety zone.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Corpus Christi Ship Channel, Corpus Christi, TX, safety zone. 165.808 Section 165.808 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PORTS AND WATERWAYS SAFETY REGULATED NAVIGATION AREAS AND LIMITED ACCESS AREAS Specific Regulated Navigatio...

Corpus Based Authenicity Analysis of Language Teaching Course Books

ERIC Educational Resources Information Center

Peksoy, Emrah; Harmaoglu, Özhan

2017-01-01

In this study, the resemblance of the language learning course books used in Turkey to authentic language spoken by native speakers is explored by using a corpus-based approach. For this, the 10-million-word spoken part of the British National Corpus was selected as reference corpus. After that, all language learning course books used in high…

Using a Corpus in a 300-Level Spanish Grammar Course

ERIC Educational Resources Information Center

Benavides, Carlos

2015-01-01

The present study examined the use and effectiveness of a large corpus--the Corpus del Español (Davies, 2002)--in a 300-level Spanish grammar university course. Students conducted hands-on corpus searches with the goal of finding concordances containing particular types of collocations (combinations of words that tend to co-occur) and tokens (any…

Computer-assisted Lemmatisation of a Cornish Text Corpus for Lexicographical Purposes

ERIC Educational Resources Information Center

Mills, Jon

2002-01-01

This project sets out to discover and develop techniques for the lemmatisation of a historical corpus of the Cornish language in order that a lemmatised dictionary macrostructure can be generated from the corpus. The system should be capable of uniquely identifying every lexical item that is attested in the corpus. A survey of published and…

31 CFR 358.19 - Who is responsible for any loss resulting from the conversion of a bearer corpus missing callable...

Code of Federal Regulations, 2012 CFR

2012-07-01

... resulting from the conversion of a bearer corpus missing callable coupons? 358.19 Section 358.19 Money and... corpus missing callable coupons? The submitting depository institution shall indemnify the United States against any loss resulting from the conversion of a bearer corpus that is missing one or more associated...

31 CFR 358.19 - Who is responsible for any loss resulting from the conversion of a bearer corpus missing callable...

Code of Federal Regulations, 2011 CFR

2011-07-01

... resulting from the conversion of a bearer corpus missing callable coupons? 358.19 Section 358.19 Money and... corpus missing callable coupons? The submitting depository institution shall indemnify the United States against any loss resulting from the conversion of a bearer corpus that is missing one or more associated...

31 CFR 358.19 - Who is responsible for any loss resulting from the conversion of a bearer corpus missing callable...

Code of Federal Regulations, 2010 CFR

2010-07-01

... resulting from the conversion of a bearer corpus missing callable coupons? 358.19 Section 358.19 Money and... corpus missing callable coupons? The submitting depository institution shall indemnify the United States against any loss resulting from the conversion of a bearer corpus that is missing one or more associated...

31 CFR 358.19 - Who is responsible for any loss resulting from the conversion of a bearer corpus missing callable...

Code of Federal Regulations, 2014 CFR

2014-07-01

... resulting from the conversion of a bearer corpus missing callable coupons? 358.19 Section 358.19 Money and... corpus missing callable coupons? The submitting depository institution shall indemnify the United States against any loss resulting from the conversion of a bearer corpus that is missing one or more associated...

31 CFR 358.19 - Who is responsible for any loss resulting from the conversion of a bearer corpus missing callable...

Code of Federal Regulations, 2013 CFR

2013-07-01

... resulting from the conversion of a bearer corpus missing callable coupons? 358.19 Section 358.19 Money and... corpus missing callable coupons? The submitting depository institution shall indemnify the United States against any loss resulting from the conversion of a bearer corpus that is missing one or more associated...

Separating Fact and Fiction: The Real Story of Corpus Use in Language Teaching

ERIC Educational Resources Information Center

Boulton, Alex

2013-01-01

This paper investigates uses of corpora in language learning ("data-driven learning") through analysis of a 600K-word corpus of empirical research papers in the field. The corpus can tell us much--the authors and the countries the studies are conducted in, the types of publication, and so on. The corpus investigation itself starts with…

Recent Developments in Corpus Linguistics and Corpus-Based Research/Department of Linguistics and Modern Language Studies at the Hong Kong Institute of Education

ERIC Educational Resources Information Center

Xie, Qin

2015-01-01

Corpus linguistics has transformed the landscape of empirical research on languages in recent decades. The proliferation of corpus technology has enabled researchers worldwide to conduct research in their own geographical locations with few hindrances. It has become increasingly commonplace for researchers to compile their own corpora for specific…

The Effects of Utilizing Corpus Resources to Correct Collocation Errors in L2 Writing--Students' Performance, Corpus Use and Perceptions

ERIC Educational Resources Information Center

Wu, Yi-ju

2016-01-01

Data-Driven Learning (DDL), in which learners "confront [themselves] directly with the corpus data" (Johns, 2002, p. 108), has shown to be effective in collocation learning in L2 writing. Nevertheless, there have been only few research studies of this type examining the relationship between English proficiency and corpus consultation.…

Contrast radiographic study of venous drainage of the corpus cavernosum and the corpus spongiosum of the cat penis.

PubMed

Amiri, Ali Akbar; Gilanpour, Hassan; Veshkini, Abbas

2014-01-01

The aim of this study was to determine the drainage routes of the corpus cvernosum penis and the corpus spongiosum penis in the cat using contrast cavernosography. Five male cats, 1.5-2.5 years old, weighing between 4.5 and 5.5 kg were investigated. The cats were anesthetized and the root and the proximal part of the penis were exposed by an incision on the perineum reaching the scrotum. Each cat was radiographed in lateral and dorsal recumbency before and during injection of contrast medium into the erectile bodies. The corpus spongiosum penis was injected at the bulb of the penis and the corpus cavernosum penis at the root. Injection of contrast media into the cavernous bodies showed that both the external and internal iliac veins drain the erectile bodies into the caudal vena cava. Drainage from the corpus spongiosum penis was from the bulb for the proximal part and from the glans for the distal part. The corpus cavernosum penis was drained only proximally, from the crura. There was a network of veins above the pelvic symphysis and the drainage of erectile bodies where through various routes into the internal and external iliac veins.

A corpus of full-text journal articles is a robust evaluation tool for revealing differences in performance of biomedical natural language processing tools

PubMed Central

2012-01-01

Background We introduce the linguistic annotation of a corpus of 97 full-text biomedical publications, known as the Colorado Richly Annotated Full Text (CRAFT) corpus. We further assess the performance of existing tools for performing sentence splitting, tokenization, syntactic parsing, and named entity recognition on this corpus. Results Many biomedical natural language processing systems demonstrated large differences between their previously published results and their performance on the CRAFT corpus when tested with the publicly available models or rule sets. Trainable systems differed widely with respect to their ability to build high-performing models based on this data. Conclusions The finding that some systems were able to train high-performing models based on this corpus is additional evidence, beyond high inter-annotator agreement, that the quality of the CRAFT corpus is high. The overall poor performance of various systems indicates that considerable work needs to be done to enable natural language processing systems to work well when the input is full-text journal articles. The CRAFT corpus provides a valuable resource to the biomedical natural language processing community for evaluation and training of new models for biomedical full text publications. PMID:22901054

Acceptance and Commitment Therapy in Improving Well-Being in Patients With Stage III-IV Cancer and Their Partners

ClinicalTrials.gov

2018-02-06

Malignant Female Reproductive System Neoplasm; Malignant Hepatobiliary Neoplasm; Partner; Stage III Breast Cancer; Stage III Cervical Cancer; Stage III Colorectal Cancer; Stage III Lung Cancer; Stage III Prostate Cancer; Stage III Skin Melanoma; Stage III Uterine Corpus Cancer; Stage IIIA Breast Cancer; Stage IIIA Cervical Cancer; Stage IIIA Colorectal Cancer; Stage IIIA Lung Carcinoma; Stage IIIA Skin Melanoma; Stage IIIA Uterine Corpus Cancer; Stage IIIB Breast Cancer; Stage IIIB Cervical Cancer; Stage IIIB Colorectal Cancer; Stage IIIB Lung Carcinoma; Stage IIIB Skin Melanoma; Stage IIIB Uterine Corpus Cancer; Stage IIIC Breast Cancer; Stage IIIC Colorectal Cancer; Stage IIIC Skin Melanoma; Stage IIIC Uterine Corpus Cancer; Stage IV Breast Cancer; Stage IV Cervical Cancer; Stage IV Colorectal Cancer; Stage IV Lung Cancer; Stage IV Prostate Cancer; Stage IV Skin Melanoma; Stage IV Uterine Corpus Cancer; Stage IVA Cervical Cancer; Stage IVA Colorectal Cancer; Stage IVA Uterine Corpus Cancer; Stage IVB Cervical Cancer; Stage IVB Colorectal Cancer; Stage IVB Uterine Corpus Cancer

A corpus and a concordancer of academic journal articles.

PubMed

Kwary, Deny A

2018-02-01

This data article presents a corpus (i.e. a selection of a big number of words in an electronic form) and a concordancer (i.e. a tool to show the word in its context of use) of academic journal articles. As the title suggests, the data were collected from research articles published in academic journals. The corpus contains 5,686,428 words selected from 895 journal articles published by Elsevier in 2011-2015. The corpus is classified into four subject areas: Health sciences, Life sciences, Physical Sciences, and Social Sciences, following the classifications of Scopus, which is the largest abstract and citation database of peer-reviewed scientific journals, books and conference proceedings. To ease the access and utilization of the corpus, a program to produce the key word in context (KWIC) and word frequency was created and placed on the website: corpus.kwary.net. The corpus is a valuable resource for researchers, teachers, and translators working on academic English.

Hemoperitoneum from corpus luteum rupture in patients with aplastic anemia.

PubMed

Wang, Huaquan; Guo, Lifang; Shao, Zonghong

2015-01-01

Aplastic anemia is a rare hematopoietic stem-cell disorder that results in pancytopenia and hypocellular bone marrow. Women with aplastic anemia usually are at increased risk of corpus luteum rupture due to thrombocytopenia and infection. Here we report two cases had hemoperitoneum from corpus luteum rupture in patients with aplastic anemia in our center. Case 1 involved two episodes of hemoperitoneum resulting from rupture of the corpus luteum in a 23-year-old unmarried female with severe aplastic anemia. This patient was managed conservatively with platelet and packed red cell transfusion. Case 2 involved two episodes of hemoperitoneum resulting from rupture of the corpus luteum in a 33-year-old married patient with aplastic anemia. Emergency laparoscopy revealed massive hemoperitoneum. Bilateral salpingo-oophorectomy were performed successively with platelet and packed red cell transfusion. Hemoperitoneum resulting from a ruptured corpus luteum is a life-threatening condition in patients with aplastic anemia. Prompt and appropriate evaluation of corpus luteum rupture and emergent therapy are needed.

Flexitouch® Home Maintenance Therapy or Standard Home Maintenance Therapy in Treating Patients With Lower-Extremity Lymphedema Caused by Treatment for Cervical Cancer, Vulvar Cancer, or Endometrial Cancer

ClinicalTrials.gov

2014-12-29

Lymphedema; Stage 0 Cervical Cancer; Stage 0 Uterine Corpus Cancer; Stage 0 Vulvar Cancer; Stage I Uterine Corpus Cancer; Stage I Vulvar Cancer; Stage IA Cervical Cancer; Stage IB Cervical Cancer; Stage II Uterine Corpus Cancer; Stage II Vulvar Cancer; Stage IIA Cervical Cancer; Stage IIB Cervical Cancer; Stage III Cervical Cancer; Stage III Uterine Corpus Cancer; Stage III Vulvar Cancer; Stage IV Uterine Corpus Cancer; Stage IVA Cervical Cancer; Stage IVB Cervical Cancer; Stage IVB Vulvar Cancer

The Wildcat Corpus of Native- and Foreign-Accented English: Communicative Efficiency across Conversational Dyads with Varying Language Alignment Profiles

ERIC Educational Resources Information Center

Van Engen, Kristin J.; Baese-Berk, Melissa; Baker, Rachel E.; Choi, Arim; Kim, Midam; Bradlow, Ann R.

2010-01-01

This paper describes the development of the Wildcat Corpus of native- and foreign-accented English, a corpus containing scripted and spontaneous speech recordings from 24 native speakers of American English and 52 non-native speakers of English. The core element of this corpus is a set of spontaneous speech recordings, for which a new method of…

An Analysis of the Application of Wikipedia Corpus on the Lexical Learning in the Second Language Acquisition

ERIC Educational Resources Information Center

Shi, Jing

2015-01-01

Corpus linguistics has transformed linguistic research but has a slightly moderate impact on the ESL teaching and learning. The Wikipedia Corpus, designed by Mark Davis is introduced in this essay. The corpus allows teachers to search Wikipedia in a powerful way: they can search by word, phrase, part of speech, and synonyms. Teachers can also find…

Training ESP Students in Corpus Use--Challenges of Using Corpus-Based Exercises with Students of Non-Philological Studies

ERIC Educational Resources Information Center

Marinov, Sanja

2013-01-01

This paper focuses on planning a series of activities to train learners of undergraduate, non-philological studies in using a small specialised ad hoc corpus and the results they achieved in doing them. The procedure discussed in this paper is a part of a larger project which investigates the possibility of using a small specialised corpus with…

Effects of citicoline therapy on the network connectivity of the corpus callosum in patients with leukoaraiosis

PubMed Central

Feng, Liang; Jiang, Hong; Li, Yunxia; Teng, Fei; He, Yusheng

2017-01-01

Abstract This study aimed to investigate the effects of citicoline therapy on the network connectivity of the corpus callosum in patients with leukoaraiosis (LA) by diffusion tension imaging (DTI). A total of 30 LA patients with Fazekas score of 2 to 3 were voluntarily assigned into citicoline group (n = 14) and control group (n = 16). In citicoline group, citicoline was administered at 0.6 g/d for 1 year. In control group, central nervous system drugs should not be used, except for sleeping pills and antidepressants. Interventions for pre-existing diseases should be conducted in both groups. During the periods of citicoline therapy and post-treatment follow-up, cranial magnetic resonance imaging and DTI were routinely performed in these patients, and the genu, body, and splenium of corpus callosum were selected as the regions of interest (ROIs). The fractional anisotropy (FA) and mean diffusivity (MD) of each ROI were determined with PANDA software. On recruitment, there were no significant differences in the general characteristics, blood biochemical results, cognition function, and the FA and MD of the corpus callosum between 2 groups (P > 0.05). After 1-year treatment, the FA of the corpus callosum reduced gradually, but the MD of the corpus callosum tended to increased in both group, although significant differences were not observed. However, the reductions in FA of genu and splenium of corpus callosum in citicoline group were significantly lower than in control group (P < 0.05); the reductions in MD of genu, body, and splenium of corpus callosum in citicoline group were significantly lower than in control group (P < 0.05). In LA patients, the disruption of the network connectivity of the corpus callosum deteriorates over time. Citicoline treatment may delay the reduction in FA of corpus callosum, which might be beneficial for the improvement of network connectivity of the corpus callosum. PMID:28121935

Modifications of Erectile Tissue Components in the Penis during the Fetal Period

PubMed Central

Gallo, Carla B. M.; Costa, Waldemar S.; Furriel, Angelica; Bastos, Ana L.; Sampaio, Francisco J. B.

2014-01-01

Background The penile erectile tissue has a complex microscopic anatomy with important functions in the mechanism of penile erection. The knowledge of such structures is necessary for understanding the normal physiology of the adult penis. Therefore, it is important to know the changes of these penile structures during fetal development. This study aims to analyze the development of the main components of the erectile tissue, such as collagen, smooth muscle fibers and elastic system fibers, in human fetuses. Methodology/Principal Findings We studied the penises of 56 human fetuses aged 13 to 36 weeks post-conception (WPC). We used histochemical and immunohistochemical staining, as well as morphometric techniques to analyze the collagen, smooth muscle fibers and elastic system fibers in the corpus cavernosum and in the corpus spongiosum. These elements were identified and quantified as percentage by using the Image J software (NIH, Bethesda, USA). From 13 to 36 WPC, in the corpus cavernosum, the amount of collagen, smooth muscle fibers and elastic system fibers varied from 19.88% to 36.60%, from 4.39% to 29.76% and from 1.91% to 8.92%, respectively. In the corpus spongiosum, the amount of collagen, smooth muscle fibers and elastic system fibers varied from 34.65% to 45.89%, from 0.60% to 11.90% and from 3.22% to 11.93%, respectively. Conclusions We found strong correlation between the elements analyzed with fetal age, both in corpus cavernosum and corpus spongiosum. The growth rate of these elements was more intense during the second trimester (13 to 24 WPC) of gestation, both in corpus cavernosum and in corpus spongiosum. There is greater proportional amount of collagen in the corpus spongiosum than in corpus cavernosum during all fetal period. In the corpus spongiosum, there is about four times more collagen than smooth muscle fibers and elastic system fibers, during all fetal period studied. PMID:25170760

Language Lateralization in Individuals with Callosal Agenesis: An fMRI Study

ERIC Educational Resources Information Center

Pelletier, Isabelle; Paquette, Natacha; Lepore, Franco; Rouleau, Isabelle; Sauerwein, Catherine H.; Rosa, Christine; Leroux, Jean-Maxime; Gravel, Pierre; Valois, Katja; Andermann, Frederick; Saint-Amour, Dave; Lassonde, Maryse

2011-01-01

Since the seminal work of Broca in 1861, it is well established that language is essentially processed in the left hemisphere. However, the origin of hemispheric specialization remains controversial. Some authors posit that language lateralization is genetically determined, while others have suggested that hemispheric specialization develops with…

Effects of castration on penile extracellular matrix morphology in domestic cats.

PubMed

Borges, Nathalia Cs; Pereira-Sampaio, Marco A; Pereira, Vivian Alves; Abidu-Figueiredo, Marcelo; Chagas, Maurício Alves

2017-12-01

Objectives This study was undertaken to verify the possible modifications caused by hormonal deprivation in the extracellular matrix in the penises of neutered cats. Methods Twenty-seven penises from domestic shorthair cats were collected: 14 samples from intact cats and 13 from neutered cats. Sections were stained with Weigert's resorcin-fuchsin, hematoxylin and eosin, and picrosirius red. Histomorphometric analysis was performed using light microscopy and image analysis software. The following parameters were analyzed: density of the elastic fibers and collagen fibers in the corpus spongiosum; density of the elastic fibers in the tunica albuginea of the corpus cavernosum and the tunica albuginea of the corpus spongiosum; luminal area of the urethra; area of the corpus spongiosum; area of the corpus cavernosum; and thickness of the urethral epithelium. The data were analyzed using the Shapiro-Wilk test to verify the normal distribution, and groups were compared using Student's t-test; P <0.05 indicated statistically significant differences. Results Significant differences were observed between intact cats and neutered cats in the density of elastic fibers in the tunica albuginea of the corpus cavernosum (8.13% ± 1.38% vs 3.11% ± 0.66%), tunica albuginea of the corpus spongiosum (4.37% ± 1.08% vs 3.30% ± 1.01%) and corpus spongiosum (6.28% ± 3.03% vs 4.10% ± 2.19%), and density of collagen fibers in the corpus spongiosum (34.11% ± 10.86% vs 44.21% ± 12.72%). Conclusions and relevance The results show a significant decrease in the density of the elastic fibers and a significant increase of the density of the collagen fibers in the corpus spongiosum in neutered animals. This suggests that the compliance of the periurethral region is reduced, and these changes could be a predisposing factor for urethral obstructive disease.

Adams-Oliver Syndrome with Unusual Central Nervous System Findings and an Extrahepatic Portosystemic Shunt

PubMed Central

Pérez-García, Carlos; Martín, Yolanda Ruíz; del Hoyo, Alejandra Aguado; Rodríguez, Carlos Marín; Domínguez, Minia Campos

2017-01-01

We report a case of a premature neonate girl with scalp and skull defects and brachydactyly of the feet consistent with an Adams-Oliver syndrome (AOS). The patient had central nervous system abnormalities, such as periventricular calcifications, hypoplastic corpus callosum, and bilateral hemispheric corticosubcortical hemorrhagic lesions. A muscular ventricular septal defect and a portosystemic shunt were diagnosed. To our knowledge, this is the first report of congenital supratentorial grey-white matter junction lesions without dural sinus thrombosis in association with AOS. Some of these lesions may be secondary to birth trauma (given the skull defect) whilst others have a watershed location, perhaps as further evidence of vascular disruption and decreased perfusion during critical periods of fetal brain development as the previously proposed pathogenesis of this syndrome. PMID:28706620

Sexual dimorphism and handedness in the human corpus callosum based on magnetic resonance imaging.

PubMed

Tuncer, M C; Hatipoğlu, E S; Ozateş, M

2005-08-01

The corpus callosum (CC) is a major anatomical and functional commissure linking the two cerebral hemispheres. With MR imaging in the sagittal plane, the corpus callosum can be depicted in great detail. Mid-sagittal magnetic resonance images of 80 normal individuals were analyzed to assess whether or not the morphology of the corpus callosum and its parts are related to sex and handedness. The subjects were 40 males (20 right-handers and 20 left-handers) and 40 females (20 right-handers and 20 left-handers). The midsagittal area of the corpus callosum was divided into seven sub-areas using Witelson's method. The most striking morphological changes concerned left-handers, who had larger areas of the anterior body, posterior body and isthmus than right-handers. In addition, right-handed males had larger rostrums and isthmuses than right-handed females. These significantly increased areas were related to handedness in right-handed males. However, left-handed males had larger anterior and posterior bodies than right-handed males. In contrast, there was no significant difference between left-handers and right-handers in females. The areas of the rostrum and posterior body of the corpus callosum increased significantly with sex in males. Moreover, there were no significant age-related changes in the total corpus callosum and sub-areas of the corpus callosum. In conclusion, these anatomical changes in corpus callosum morphology require taking the sexual definition and dominant handedness into consideration.

Vaccine Therapy With or Without Sirolimus in Treating Patients With NY-ESO-1 Expressing Solid Tumors

ClinicalTrials.gov

2016-10-03

Anaplastic Astrocytoma; Anaplastic Oligoastrocytoma; Anaplastic Oligodendroglioma; Estrogen Receptor Negative; Estrogen Receptor Positive; Glioblastoma; Hormone-Resistant Prostate Cancer; Metastatic Prostate Carcinoma; Metastatic Renal Cell Cancer; Recurrent Adult Brain Neoplasm; Recurrent Bladder Carcinoma; Recurrent Breast Carcinoma; Recurrent Colorectal Carcinoma; Recurrent Esophageal Carcinoma; Recurrent Gastric Carcinoma; Recurrent Hepatocellular Carcinoma; Recurrent Lung Carcinoma; Recurrent Melanoma; Recurrent Ovarian Carcinoma; Recurrent Prostate Carcinoma; Recurrent Renal Cell Carcinoma; Recurrent Uterine Corpus Carcinoma; Resectable Hepatocellular Carcinoma; Sarcoma; Stage IA Breast Cancer; Stage IA Ovarian Cancer; Stage IA Uterine Corpus Cancer; Stage IB Breast Cancer; Stage IB Ovarian Cancer; Stage IB Uterine Corpus Cancer; Stage IC Ovarian Cancer; Stage II Uterine Corpus Cancer; Stage IIA Breast Cancer; Stage IIA Lung Carcinoma; Stage IIA Ovarian Cancer; Stage IIB Breast Cancer; Stage IIB Esophageal Cancer; Stage IIB Lung Carcinoma; Stage IIB Ovarian Cancer; Stage IIB Skin Melanoma; Stage IIC Ovarian Cancer; Stage IIC Skin Melanoma; Stage IIIA Breast Cancer; Stage IIIA Esophageal Cancer; Stage IIIA Lung Carcinoma; Stage IIIA Ovarian Cancer; Stage IIIA Skin Melanoma; Stage IIIA Uterine Corpus Cancer; Stage IIIB Breast Cancer; Stage IIIB Esophageal Cancer; Stage IIIB Ovarian Cancer; Stage IIIB Skin Melanoma; Stage IIIB Uterine Corpus Cancer; Stage IIIC Breast Cancer; Stage IIIC Esophageal Cancer; Stage IIIC Ovarian Cancer; Stage IIIC Skin Melanoma; Stage IIIC Uterine Corpus Cancer; Stage IV Bladder Urothelial Carcinoma; Stage IV Esophageal Cancer; Stage IV Ovarian Cancer; Stage IV Prostate Cancer; Stage IV Skin Melanoma; Stage IVA Uterine Corpus Cancer; Stage IVB Uterine Corpus Cancer

KCC3 axonopathy: neuropathological features in the central and peripheral nervous system.

PubMed

Auer, Roland N; Laganière, Janet L; Robitaille, Yves O; Richardson, John; Dion, Patrick A; Rouleau, Guy A; Shekarabi, Masoud

2016-09-01

Hereditary motor and sensory neuropathy associated with agenesis of the corpus callosum (HMSN/ACC) is an autosomal recessive disease of the central and peripheral nervous system that presents as early-onset polyneuropathy. Patients are hypotonic and areflexic from birth, with abnormal facial features and atrophic muscles. Progressive peripheral neuropathy eventually confines them to a wheelchair in the second decade of life, and death occurs by the fourth decade. We here define the neuropathologic features of the disease in autopsy tissues from eight cases. Both developmental and neurodegenerative features were found. Hypoplasia or absence of the major telencephalic commissures and a hypoplasia of corticospinal tracts to half the normal size, were the major neurodevelopmental defects we observed. Despite being a neurodegenerative disease, preservation of brain weight and a conspicuous absence of neuronal or glial cell death were signal features of this disease. Small tumor-like overgrowths of axons, termed axonomas, were found in the central and peripheral nervous system, indicating attempted axonal regeneration. We conclude that the neurodegenerative deficits in HMSN/ACC are primarily caused by an axonopathy superimposed upon abnormal development, affecting peripheral but also central nervous system axons, all ultimately because of a genetic defect in the axonal cotransporter KCC3.

A homozygous mutation in RNU4ATAC as a cause of microcephalic osteodysplastic primordial dwarfism type I (MOPD I) with associated pigmentary disorder.

PubMed

Abdel-Salam, Ghada M H; Miyake, Noriko; Eid, Maha M; Abdel-Hamid, Mohamed S; Hassan, Nihal A; Eid, Ola M; Effat, Laila K; El-Badry, Tarek H; El-Kamah, Ghada Y; El-Darouti, Mohamed; Matsumoto, Naomichi

2011-11-01

The designation microcephalic osteodysplastic primordial dwarfism (MOPD) refers to a group of autosomal recessive disorders, comprising microcephaly, growth retardation, and a skeletal dysplasia. The different types of MOPD have been delineated on the basis of clinical, radiological, and genetic criteria. We describe two brothers, born to healthy, consanguineous parents, with intrauterine and postnatal growth retardation, microcephaly with abnormal gyral pattern and partial agenesis of corpus callosum, and skeletal anomalies reminiscent of those described in MOPD type I. This was confirmed by the identification of the homozygous g.55G > A mutation of RNU4ATAC encoding U4atac snRNA. The sibs had yellowish-gray hair, fair skin, and deficient retinal pigmentation. Skin biopsy showed abnormal melanin function but OCA genes were normal. The older sib had an intracranial hemorrhage at 1 week after birth, the younger developed chilblains-like lesions at the age 2½ years old but analysis of the SAMHD1 and TREX1 genes did not show any mutations. To the best of our knowledge, vasculopathy and pigmentary disorders have not been reported in MOPD I. Copyright © 2011 Wiley Periodicals, Inc.

Profound microcephaly, primordial dwarfism with developmental brain malformations: a new syndrome.

PubMed

Abdel-Salam, Ghada M H; Abdel-Hamid, Mohamed S; Saleem, Sahar N; Ahmed, Mahmoud K H; Issa, Mahmoud; Effat, Laila K; Kayed, Hisham F; Zaki, Maha S; Gaber, Khaled R

2012-08-01

We describe two sibs with a lethal form of profound congenital microcephaly, intrauterine and postnatal growth retardation, subtle skeletal changes, and poorly developed brain. The sibs had striking absent cranial vault with sloping of the forehead, large beaked nose, relatively large ears, and mandibular micro-retrognathia. Brain magnetic resonance imaging (MRI) revealed extremely simplified gyral pattern, large interhemispheric cyst and agenesis of corpus callosum, abnormally shaped hippocampus, and proportionately affected cerebellum and brainstem. In addition, fundus examination showed foveal hypoplasia with optic nerve atrophy. No abnormalities of the internal organs were found. This profound form of microcephaly was identified at 17 weeks gestation by ultrasound and fetal brain MRI helped in characterizing the developmental brain malformations in the second sib. Molecular analysis excluded mutations in potentially related genes such as RNU4ATAC, SLC25A19, and ASPM. These clinical and imaging findings are unlike that of any recognized severe forms of microcephaly which is believed to be a new microcephalic primordial dwarfism (MPD) with developmental brain malformations with most probably autosomal recessive inheritance based on consanguinity and similarly affected male and female sibs. Copyright © 2012 Wiley Periodicals, Inc.

Neuroimaging findings of congenital Zika virus infection: a pictorial essay.

PubMed

Zare Mehrjardi, Mohammad; Poretti, Andrea; Huisman, Thierry A G M; Werner, Heron; Keshavarz, Elham; Araujo Júnior, Edward

2017-03-01

Zika virus (ZIKV) is a mosquito-borne arbovirus from the Flaviviridae family. It had caused several epidemics since its discovery in 1947, but there was no significant attention to this virus until the recent outbreak in Brazil in 2015. The main concern is the causal relationship between prenatal ZIKV infection and congenital microcephaly, which has been confirmed recently. Moreover, ZIKV may cause other central nervous system abnormalities such as brain parenchymal atrophy with secondary ventriculomegaly, intracranial calcification, malformations of cortical development (such as polymicrogyria, and lissencephaly-pachygyria), agenesis/hypoplasia of the corpus callosum, cerebellar and brainstem hypoplasia, sensorineural hearing-loss, and ocular abnormalities as well as arthrogryposis in the infected fetuses. Postnatal (acquired) ZIKV infection usually has an asymptomatic or mildly symptomatic course, while prenatal (congenital) ZIKV infection has a more severe course and may cause severe brain anomalies that are described as congenital Zika syndrome. In this pictorial essay, we aim to illustrate the prenatal and postnatal neuroimaging findings that may be seen in fetuses and neonates with congenital Zika syndrome, and will discuss possible radiological differential diagnoses. A detailed knowledge of these findings is paramount for an early correct diagnosis, prognosis determination, and counseling of the affected children and families.

A myelin gene causative of a catatonia-depression syndrome upon aging

PubMed Central

Hagemeyer, Nora; Goebbels, Sandra; Papiol, Sergi; Kästner, Anne; Hofer, Sabine; Begemann, Martin; Gerwig, Ulrike C; Boretius, Susann; Wieser, Georg L; Ronnenberg, Anja; Gurvich, Artem; Heckers, Stephan H; Frahm, Jens; Nave, Klaus-Armin; Ehrenreich, Hannelore

2012-01-01

Severe mental illnesses have been linked to white matter abnormalities, documented by postmortem studies. However, cause and effect have remained difficult to distinguish. CNP (2′,3′-cyclic nucleotide 3′-phosphodiesterase) is among the oligodendrocyte/myelin-associated genes most robustly reduced on mRNA and protein level in brains of schizophrenic, bipolar or major depressive patients. This suggests that CNP reduction might be critical for a more general disease process and not restricted to a single diagnostic category. We show here that reduced expression of CNP is the primary cause of a distinct behavioural phenotype, seen only upon aging as an additional ‘pro-inflammatory hit’. This phenotype is strikingly similar in Cnp heterozygous mice and patients with mental disease carrying the AA genotype at CNP SNP rs2070106. The characteristic features in both species with their partial CNP ‘loss-of-function’ genotype are best described as ‘catatonia-depression’ syndrome. As a consequence of perturbed CNP expression, mice show secondary low-grade inflammation/neurodegeneration. Analogously, in man, diffusion tensor imaging points to axonal loss in the frontal corpus callosum. To conclude, subtle white matter abnormalities inducing neurodegenerative changes can cause/amplify psychiatric diseases. PMID:22473874

Novel Compound Heterozygous Spatacsin Mutations in a Greek Kindred with Hereditary Spastic Paraplegia SPG11 and Dementia.

PubMed

Fraidakis, Matthew J; Brunetti, Maura; Blackstone, Craig; Filippi, Massimo; Chiò, Adriano

2016-01-01

SPG11 belongs to the autosomal recessive hereditary spastic paraplegias (HSP) and presents during childhood or puberty with a complex clinical phenotype encompassing learning difficulties, ataxia, peripheral neuropathy, amyotrophy, and mental retardation. We hereby present the case of a 30-year-old female patient with complex autosomal recessive HSP with thinning of the corpus callosum (TCC) and dementia that was compound heterozygous with two novel mutations in the SPG11 gene. Sequence analysis of the SPG11 gene revealed two novel mutations in a compound heterozygous state in the index patient (c.2431C>T/p.Gln811Ter and c.6755_6756insT/p.Glu2252Aspfs*88). MRI showed abnormal TCC, white matter (WM) hyperintensities periventricularly, and the 'ears of the lynx' sign. Diffusion tensor imaging showed a mild-to-moderate decrease in fractional anisotropy and an increase in mean diffusivity in WM compared to age-matched controls, while magnetic resonance spectroscopy showed abnormal findings in affected WM with a decrease in N-acetyl-aspartate in WM regions of interest. This is the first SPG11 kindred from the Greek population to be reported in the medical literature. © 2016 S. Karger AG, Basel.

Gray matter and white matter abnormalities in online game addiction.

PubMed

Weng, Chuan-Bo; Qian, Ruo-Bing; Fu, Xian-Ming; Lin, Bin; Han, Xiao-Peng; Niu, Chao-Shi; Wang, Ye-Han

2013-08-01

Online game addiction (OGA) has attracted greater attention as a serious public mental health issue. However, there are only a few brain magnetic resonance imaging studies on brain structure about OGA. In the current study, we used voxel-based morphometry (VBM) analysis and tract-based spatial statistics (TBSS) to investigate the microstructural changes in OGA and assessed the relationship between these morphology changes and the Young's Internet Addiction Scale (YIAS) scores within the OGA group. Compared with healthy subjects, OGA individuals showed significant gray matter atrophy in the right orbitofrontal cortex, bilateral insula, and right supplementary motor area. According to TBSS analysis, OGA subjects had significantly reduced FA in the right genu of corpus callosum, bilateral frontal lobe white matter, and right external capsule. Gray matter volumes (GMV) of the right orbitofrontal cortex, bilateral insula and FA values of the right external capsule were significantly positively correlated with the YIAS scores in the OGA subjects. Our findings suggested that microstructure abnormalities of gray and white matter were present in OGA subjects. This finding may provide more insights into the understanding of the underlying neural mechanisms of OGA. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Automated Identification of Abnormal Adult EEGs

PubMed Central

López, S.; Suarez, G.; Jungreis, D.; Obeid, I.; Picone, J.

2016-01-01

The interpretation of electroencephalograms (EEGs) is a process that is still dependent on the subjective analysis of the examiners. Though interrater agreement on critical events such as seizures is high, it is much lower on subtler events (e.g., when there are benign variants). The process used by an expert to interpret an EEG is quite subjective and hard to replicate by machine. The performance of machine learning technology is far from human performance. We have been developing an interpretation system, AutoEEG, with a goal of exceeding human performance on this task. In this work, we are focusing on one of the early decisions made in this process – whether an EEG is normal or abnormal. We explore two baseline classification algorithms: k-Nearest Neighbor (kNN) and Random Forest Ensemble Learning (RF). A subset of the TUH EEG Corpus was used to evaluate performance. Principal Components Analysis (PCA) was used to reduce the dimensionality of the data. kNN achieved a 41.8% detection error rate while RF achieved an error rate of 31.7%. These error rates are significantly lower than those obtained by random guessing based on priors (49.5%). The majority of the errors were related to misclassification of normal EEGs. PMID:27195311

Clinical features and neuroimaging (CT and MRI) findings in presumed Zika virus related congenital infection and microcephaly: retrospective case series study.

PubMed

de Fatima Vasco Aragao, Maria; van der Linden, Vanessa; Brainer-Lima, Alessandra Mertens; Coeli, Regina Ramos; Rocha, Maria Angela; Sobral da Silva, Paula; Durce Costa Gomes de Carvalho, Maria; van der Linden, Ana; Cesario de Holanda, Arthur; Valenca, Marcelo Moraes

2016-04-13

To report radiological findings observed in computed tomography (CT) and magnetic resonance imaging (MRI) scans of the first cases of congenital infection and microcephaly presumably associated with the Zika virus in the current Brazilian epidemic. Retrospective study with a case series. Association for Assistance of Disabled Children (AACD), Pernambuco state, Brazil. 23 children with a diagnosis of congenital infection presumably associated with the Zika virus during the Brazilian microcephaly epidemic. Types of abnormalities and the radiological pattern of lesions identified on CT and MRI brain scans. Six of the 23 children tested positive for IgM antibodies to Zika virus in cerebrospinal fluid. The other 17 children met the protocol criteria for congenital infection presumably associated with the Zika virus, even without being tested for IgM antibodies to the virus--the test was not yet available on a routine basis. Of the 23 children, 15 underwent CT, seven underwent both CT and MRI, and one underwent MRI. Of the 22 children who underwent CT, all had calcifications in the junction between cortical and subcortical white matter, 21 (95%) had malformations of cortical development, 20 (91%) had a decreased brain volume, 19 (86%) had ventriculomegaly, and 11 (50%) had hypoplasia of the cerebellum or brainstem. Of the eight children who underwent MRI, all had calcifications in the junction between cortical and subcortical white matter, malformations of cortical development occurring predominantly in the frontal lobes, and ventriculomegaly. Seven of the eight (88%) children had enlarged cisterna magna, seven (88%) delayed myelination, and six each (75%) a moderate to severe decrease in brain volume, simplified gyral pattern, and abnormalities of the corpus callosum (38% hypogenesis and 38% hypoplasia). Malformations were symmetrical in 75% of the cases. Severe cerebral damage was found on imaging in most of the children in this case series with congenital infection presumably associated with the Zika virus. The features most commonly found were brain calcifications in the junction between cortical and subcortical white matter associated with malformations of cortical development, often with a simplified gyral pattern and predominance of pachygyria or polymicrogyria in the frontal lobes. Additional findings were enlarged cisterna magna, abnormalities of corpus callosum (hypoplasia or hypogenesis), ventriculomegaly, delayed myelination, and hypoplasia of the cerebellum and the brainstem. 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.

Clinical features and neuroimaging (CT and MRI) findings in presumed Zika virus related congenital infection and microcephaly: retrospective case series study

PubMed Central

van der Linden, Vanessa; Brainer-Lima, Alessandra Mertens; Coeli, Regina Ramos; Rocha, Maria Angela; Sobral da Silva, Paula; Durce Costa Gomes de Carvalho, Maria; van der Linden, Ana; Cesario de Holanda, Arthur; Valenca, Marcelo Moraes

2016-01-01

Objective To report radiological findings observed in computed tomography (CT) and magnetic resonance imaging (MRI) scans of the first cases of congenital infection and microcephaly presumably associated with the Zika virus in the current Brazilian epidemic. Design Retrospective study with a case series. Setting Association for Assistance of Disabled Children (AACD), Pernambuco state, Brazil. Participants 23 children with a diagnosis of congenital infection presumably associated with the Zika virus during the Brazilian microcephaly epidemic. Main outcome measures Types of abnormalities and the radiological pattern of lesions identified on CT and MRI brain scans. Results Six of the 23 children tested positive for IgM antibodies to Zika virus in cerebrospinal fluid. The other 17 children met the protocol criteria for congenital infection presumably associated with the Zika virus, even without being tested for IgM antibodies to the virus—the test was not yet available on a routine basis. Of the 23 children, 15 underwent CT, seven underwent both CT and MRI, and one underwent MRI. Of the 22 children who underwent CT, all had calcifications in the junction between cortical and subcortical white matter, 21 (95%) had malformations of cortical development, 20 (91%) had a decreased brain volume, 19 (86%) had ventriculomegaly, and 11 (50%) had hypoplasia of the cerebellum or brainstem. Of the eight children who underwent MRI, all had calcifications in the junction between cortical and subcortical white matter, malformations of cortical development occurring predominantly in the frontal lobes, and ventriculomegaly. Seven of the eight (88%) children had enlarged cisterna magna, seven (88%) delayed myelination, and six each (75%) a moderate to severe decrease in brain volume, simplified gyral pattern, and abnormalities of the corpus callosum (38% hypogenesis and 38% hypoplasia). Malformations were symmetrical in 75% of the cases. Conclusion Severe cerebral damage was found on imaging in most of the children in this case series with congenital infection presumably associated with the Zika virus. The features most commonly found were brain calcifications in the junction between cortical and subcortical white matter associated with malformations of cortical development, often with a simplified gyral pattern and predominance of pachygyria or polymicrogyria in the frontal lobes. Additional findings were enlarged cisterna magna, abnormalities of corpus callosum (hypoplasia or hypogenesis), ventriculomegaly, delayed myelination, and hypoplasia of the cerebellum and the brainstem. PMID:27075009

Insights from a Learner Corpus as Opposed to a Native Corpus about Cohesive Devices in an Academic Writing Context

ERIC Educational Resources Information Center

Ersanli, Ceylan Yangin

2015-01-01

This study reports on the insights from an EFL learner corpora (a total of 151 essays and 49,690 words) generated from essays collected over the years in a Turkish state university from freshmen students enrolling in the Advanced Writing course. The comparison of cohesive devices in the non-native corpus (NNC) with those in a native corpus (NC)…

Patterns of magnetic resonance imaging abnormalities in symptomatic patients with Krabbe disease correspond to phenotype.

PubMed

Abdelhalim, Ahmed N; Alberico, Ronald A; Barczykowski, Amy L; Duffner, Patricia K

2014-02-01

Initial magnetic resonance imaging studies of individuals with Krabbe disease were analyzed to determine whether the pattern of abnormalities corresponded to the phenotype. This was a retrospective, nonblinded study. Families/patients diagnosed with Krabbe disease submitted medical records and magnetic resonance imaging discs for central review. Institutional review board approval/informed consents were obtained. Sixty-four magnetic resonance imaging scans were reviewed by two neuroradiologists and a child neurologist according to phenotype: early infantile (onset 0-6 months) = 39 patients; late infantile (onset 7-12 months) = 10 patients; later onset (onset 13 months-10 years) = 11 patients; adolescent (onset 11-20 years) = one patient; and adult (21 years or greater) = three patients. Local interpretations were compared with central review. Magnetic resonance imaging abnormalities differed among phenotypes. Early infantile patients had a predominance of increased intensity in the dentate/cerebellar white matter as well as changes in the deep cerebral white matter. Later onset patients did not demonstrate involvement in the dentate/cerebellar white matter but had extensive involvement of the deep cerebral white matter, parieto-occipital region, and posterior corpus callosum. Late infantile patients exhibited a mixed pattern; 40% had dentate/cerebellar white matter involvement while all had involvement of the deep cerebral white matter. Adolescent/adult patients demonstrated isolated corticospinal tract involvement. Local and central reviews primarily differed in interpretation of the early infantile phenotype. Analysis of magnetic resonance imaging in a large cohort of symptomatic patients with Krabbe disease demonstrated imaging abnormalities correspond to specific phenotypes. Knowledge of these patterns along with typical clinical signs/symptoms should promote earlier diagnosis and facilitate treatment. Copyright © 2014 Elsevier Inc. All rights reserved.

Aetiological differences in neuroanatomy of the vegetative state: insights from diffusion tensor imaging and functional implications.

PubMed

Newcombe, Virginia F J; Williams, Guy B; Scoffings, Daniel; Cross, Justin; Carpenter, T Adrian; Pickard, John D; Menon, David K

2010-05-01

An improved in vivo understanding of variations in neuropathology in the vegetative state (VS) may aid diagnosis, improve prognostication and help refine the selection of patients for particular treatment regimes. The authors have used diffusion tensor imaging (DTI) to characterise the extent and location of white matter loss in VS secondary to traumatic brain injury (TBI) and ischaemic-hypoxic injury. Twelve patients with VS (seven TBI, five ischaemic/hypoxic injuries) underwent MRI including DTI at a minimum of 3 months postinjury. Mean apparent diffusion coefficient, fractional anisotropy and eigenvalues were obtained for whole-brain grey and white matter, the pons, thalamus, ventral midbrain, dorsal midbrain and the corpus callosum. DTI measures of supratentorial damage were compared with a summed measure from the JFK modified Coma Recovery Scale (CRS-R) and with a three-point scale of functional magnetic resonance imaging (fMRI) response to an auditory paradigm to assess whether residual integrity of supratentorial white matter connectivity correlated with cortical processing. Conventional radiological approaches did not detect lesions in regions where quantitative DTI demonstrated abnormalities. There was evidence of marked, broadly similar, abnormalities in the supratentorial grey- and white-matter compartments from both aetiologies. In contrast, discordant findings were found in the infratentorial compartment, with DTI abnormalities in the brainstem confined to the TBI group. Supratentorial DTI abnormalities correlated with the CRS-R as well as responses to an fMRI paradigm that detected convert cognitive processing. DTI may help to characterise differences in patients in VS. These findings may have implications for response to therapies, and should be taken into account in trials of interventions aimed at arousal in VS.

Brain magnetic resonance imaging findings in Smith-Lemli-Opitz syndrome.

PubMed

Lee, Ryan W Y; Conley, Sandra K; Gropman, Andrea; Porter, Forbes D; Baker, Eva H

2013-10-01

Smith-Lemli-Opitz syndrome (SLOS) is a neurodevelopmental disorder caused by inborn errors of cholesterol metabolism resulting from mutations in 7-dehydrocholesterol reductase (DHCR7). There are only a few studies describing the brain imaging findings in SLOS. This study examines the prevalence of magnetic resonance imaging (MRI) abnormalities in the largest cohort of patients with SLOS to date. Fifty-five individuals with SLOS (27 M, 28 F) between age 0.17 years and 25.4 years (mean = 6.2, SD = 5.8) received a total of 173 brain MRI scans (mean = 3.1 per subject) on a 1.5T GE scanner between September 1998 and December 2003, or on a 3T Philips scanner between October 2010 and September 2012; all exams were performed at the Clinical Center of the National Institutes of Health. We performed a retrospective review of these imaging studies for both major and minor brain anomalies. Aberrant MRI findings were observed in 53 of 55 (96%) SLOS patients, with abnormalities of the septum pellucidum the most frequent (42/55, 76%) finding. Abnormalities of the corpus callosum were found in 38 of 55 (69%) patients. Other findings included cerebral atrophy, cerebellar atrophy, colpocephaly, white matter lesions, arachnoid cysts, Dandy-Walker variant, and type I Chiari malformation. Significant correlations were observed when comparing MRI findings with sterol levels and somatic malformations. Individuals with SLOS commonly have anomalies involving the midline and para-midline structures of the brain. Further studies are required to examine the relationship between structural brain abnormalities and neurodevelopmental disability in SLOS. © 2013 The Authors. American Journal of Medical Genetics Part A Published by U.S. Government Work.

Classic infantile Pompe patients approaching adulthood: a cohort study on consequences for the brain.

PubMed

Ebbink, Berendine J; Poelman, Esther; Aarsen, Femke K; Plug, Iris; Régal, Luc; Muentjes, Carsten; van der Beek, Nadine A M E; Lequin, Maarten H; van der Ploeg, Ans T; van den Hout, Johanna M P

2018-06-01

To examine the long-term consequences of glycogen storage in the central nervous system (CNS) for classic infantile Pompe disease using enzyme replacement therapy. Using neuropsychological tests and brain magnetic resonance imaging (MRI), we prospectively assessed a cohort of 11 classic infantile Pompe patients aged up to 17 years. From approximately age 2 years onwards, brain MRI showed involvement of the periventricular white matter and centrum semiovale. After 8 years of age, additional white-matter abnormalities occurred in the corpus callosum, internal and external capsule, and subcortical areas. From 11 years of age, white-matter abnormalities were also found in the brainstem. Although there seemed to be a characteristic pattern of involvement over time, there were considerable variations between patients, reflected by variations in neuropsychological development. Cognitive development ranged from stable and normal to declines that lead to intellectual disabilities. As treatment enables patients with classic infantile Pompe disease to reach adulthood, white-matter abnormalities are becoming increasingly evident, affecting the neuropsychological development. Therefore, we advise follow-up programs are expanded to capture CNS involvement in larger, international patient cohorts, to incorporate our findings in the counselling of parents before the start of treatment, and to include the brain as an additional target in the development of next-generation therapeutic strategies for classic infantile Pompe disease. In our long-term survivors treated intravenously with enzyme replacement therapy, we found slowly progressive symmetric white-matter abnormalities. Cognitive development varied from stable and normal to declines towards intellectual disabilities. © 2018 The Authors. Developmental Medicine & Child Neurology published by John Wiley & Sons Ltd on behalf of Mac Keith Press.

The relationship between white matter abnormalities and cognitive functions in new-onset juvenile myoclonic epilepsy.

PubMed

Ekmekci, Burcu; Bulut, Hacı Taner; Gümüştaş, Funda; Yıldırım, Adem; Kuştepe, Ali

2016-09-01

Diffusion tensor imaging (DTI) has revealed evidence of subcortical white matter abnormalities in the frontal area in juvenile myoclonic epilepsy (JME). Decreased fractional anisotropy (FA) and increased mean diffusivity (MD) in the corticothalamic pathway have been detected in adult patients with JME. It has been demonstrated that, in adult patients with JME, frontal dysfunction is related to subcortical white matter damage and decreased volume in frontal cortical gray matter and the thalamus. Many studies have focused on adult patients. Twenty-four patients and 28 controls were evaluated. The group with JME had significantly worse results for the word fluency, trail-B, and Stroop tests that assessed executive functions. A significant decrease in FA values in the dorsolateral prefrontal cortex (DLPFC), the supplementary motor area (SMA), the right thalamus, the posterior cingulate, the corpus callosum anterior, the corona radiata, and the middle frontal white matter (MFWM) and an increase in ADC values in patients with JME were detected. The correlation between FA values in DLPFC and the letter fluency test results was positive, and the correlation with the Stroop and trail-B test results was negative. We found a negative correlation between SMA, anterior thalamus, and MFWM FA values and the trail-B test results and a positive correlation between the SMA, anterior thalamus, and MFWM FA values and the letter fluency test results. We detected white matter and gray matter abnormalities in patients with new-onset JME using DTI. In addition, we determined the relationship between cognitive deficit and microstructural abnormalities by evaluating the correlation between the neuropsychological test battery results and DTI parameters. We evaluated newly diagnosed patients with JME in our study. That leads us to believe that microstructural abnormalities exist from the very beginning of the disease and that they result from the genetic basis of the disease. Copyright © 2016 Elsevier Inc. All rights reserved.

MRI anatomy of schizophrenia.

PubMed

McCarley, R W; Wible, C G; Frumin, M; Hirayasu, Y; Levitt, J J; Fischer, I A; Shenton, M E

1999-05-01

Structural magnetic resonance imaging (MRI) data have provided much evidence in support of our current view that schizophrenia is a brain disorder with altered brain structure, and consequently involving more than a simple disturbance in neurotransmission. This review surveys 118 peer-reviewed studies with control group from 1987 to May 1998. Most studies (81%) do not find abnormalities of whole brain/intracranial contents, while lateral ventricle enlargement is reported in 77%, and third ventricle enlargement in 67%. The temporal lobe was the brain parenchymal region with the most consistently documented abnormalities. Volume decreases were found in 62% of 37 studies of whole temporal lobe, and in 81% of 16 studies of the superior temporal gyrus (and in 100% with gray matter separately evaluated). Fully 77% of the 30 studies of the medial temporal lobe reported volume reduction in one or more of its constituent structures (hippocampus, amygdala, parahippocampal gyrus). Despite evidence for frontal lobe functional abnormalities, structural MRI investigations less consistently found abnormalities, with 55% describing volume reduction. It may be that frontal lobe volume changes are small, and near the threshold for MRI detection. The parietal and occipital lobes were much less studied; about half of the studies showed positive findings. Most studies of cortical gray matter (86%) found volume reductions were not diffuse, but more pronounced in certain areas. About two thirds of the studies of subcortical structures of thalamus, corpus callosum and basal ganglia (which tend to increase volume with typical neuroleptics), show positive findings, as do almost all (91%) studies of cavum septi pellucidi (CSP). Most data were consistent with a developmental model, but growing evidence was compatible also with progressive, neurodegenerative features, suggesting a "two-hit" model of schizophrenia, for which a cellular hypothesis is discussed. The relationship of clinical symptoms to MRI findings is reviewed, as is the growing evidence suggesting structural abnormalities differ in affective (bipolar) psychosis and schizophrenia.

Frequency Analysis of the Words in the Academic Word List (AWL) and Non-AWL Content Words in Applied Linguistics Research Papers

ERIC Educational Resources Information Center

Vongpumivitch, Viphavee; Huang, Ju-yu; Chang, Yu-Chia

2009-01-01

This study is a corpus-based lexical study that aims to explore the use of words in Coxhead's (2000) Academic Word List (AWL) in journal articles in the field of applied linguistics. A 1.5 million-word corpus called the Applied Linguistics Research Articles Corpus (ALC) was created for this study. The corpus consists of 200 research articles that…

The Ubuntu Chat Corpus for Multiparticipant Chat Analysis

DTIC Science & Technology

2013-03-01

Intelligence (www.aaai.org). All rights reserved. the # LINUX corpus (Elsner and Charniak 2010), and the #IPHONE/#PHYSICS/#PYTHON corpus (Adams 2008). For many...made publicly available, making it difficult to comparatively evaluate dif- ferent techniques. Corpus Description Ubuntu, a Linux -based operating...Kubuntu (Ubuntu with KDE ) support #ubuntu-devel 2 112 074 12 140 53.7 2004-10-01 Developmental team coordination #ubuntu+1 1 621 680 26 805 52.6 2007-04-04

Abnormal electroretinogram associated with developmental brain anomalies.

PubMed Central

Cibis, G W; Fitzgerald, K M

1995-01-01

PURPOSE: We have encountered abnormal ERGs associated with optic nerve hypoplasia, macular, optic nerve and chorioretinal colobomata and developmental brain anomalies. Brain anomalies include cortical dysgenesis, lissencephaly, porencephaly, cerebellar and corpus callosum hypoplasia. We describe six exemplar cases. METHODS: Scotopic and photopic ERGs adherent to international standards were performed as well as photopic ERGs to long-duration stimuli. CT or MRI studies were also done. The ERGs were compared to age-matched normal control subjects. RESULTS: ERG changes include reduced amplitude b-waves to blue and red stimuli under scotopic testing conditions. Implicit times were often delayed. The photopic responses also showed reduced amplitude a- and b-waves with implicit time delays. The long-duration photopic ERG done in one case shows attenuation of both ON- and OFF-responses. CONCLUSIONS: Common underlying developmental genetic or environmental unifying casualties are speculated to be at fault in causing these cases of associated retinal and brain abnormalities. No single etiology is expected. Multiple potential causes acting early in embryogenesis effecting neuronal induction, migration and differentiation are theorized. These occur at a time when brain and retinal cells are sufficiently undifferentiated to be similarly effected. We call these cases examples of Brain Retina Neuroembryodysgenesis (BRNED). Homeobox and PAX genes with global neuronal developmental influences are gene candidates to unify the observed disruption of brain and retinal cell development. The ERG can provide a valuable clinical addition in understanding and ultimately classifying these disorders. Images FIGURE 1 FIGURE 4 FIGURE 5 FIGURE 6 FIGURE 7 FIGURE 8 PMID:8719676

Converging evidence for abnormalities of the prefrontal cortex and evaluation of midsagittal structures in pediatric PTSD: an MRI study

PubMed Central

Carrion, Victor G.; Weems, Carl F.; Watson, Christa; Eliez, Stephan; Menon, Vinod; Reiss, Allan L.

2009-01-01

Objective Volumetric imaging research has shown abnormal brain morphology in posttraumatic stress disorder (PTSD) when compared to controls. We present results on a study of brain morphology in the prefrontal cortex (PFC) and midline structures, via indices of gray matter volume and density, in pediatric PTSD. We hypothesized that both methods would demonstrate aberrant morphology in the PFC. Further, we hypothesized aberrant brainstem anatomy and reduced corpus collosum volume in children with PTSD. Methods Twenty-four children (aged 7-14) with history of interpersonal trauma and 24 age, and gender matched controls underwent structural magnetic resonance imaging. Images of the PFC and midline brain structures were first analyzed using volumetric image analysis. The PFC data were then compared with whole-brain voxel-based techniques using statistical parametric mapping (SPM). Results The PTSD group showed significant increased gray matter volume in the right and left inferior and superior quadrants of the prefrontal cortex and smaller gray matter volume in pons, and posterior vermis areas by volumetric image analysis. The voxel-byvoxel group comparisons demonstrated increased gray matter density mostly localized to ventral PFC as compared to the control group. Conclusions Abnormal frontal lobe morphology, as revealed by separate-complementary image analysis methods, and reduced pons and posterior vermis areas are associated with pediatric PTSD. Voxel-based morphometry may help to corroborate and further localize data obtained by volume of interest methods in PTSD. PMID:19349151

Cutis tricolor: a literature review and report of five new cases

PubMed Central

Polizzi, Agata; Schepis, Carmelo; Morano, Massimiliano; Strano, Serena; Belfiore, Giuseppe; Palmucci, Stefano; Foti, Pietro Valerio; Pirrone, Concetta; Roggini, Mario; David, Emanule; Salpietro, Vincenzo; Milone, Pietro

2016-01-01

Background Cutis tricolor is a skin abnormality consisting in a combination of congenital hyper- and hypopigmented skin lesions (in the form of paired macules, patches or streaks) in close proximity to each other in a background of normal skin. It is currently regarded as a twin-spotting (mosaic) phenomenon and today is clear that not all cases of cutis tricolor represent one single entity. This phenomenon has been reported so far either: (I) as an purely cutaneous trait; (II) as a part of a complex malformation phenotype (Ruggieri-Happle syndrome, RHS) including distinct facial features, eye (cataract), skeletal (skull and vertebral defects, and long bones dysplasia), nervous system (corpus callosum, cerebellar and white matter anomalies, cavum vergae and holoprosencephaly) and systemic abnormalities; (III) as a distinct type with multiple, disseminated smaller skin macules (cutis tricolor parvimaculata); and (IV) in association with other skin disturbances [e.g., cutis marmorata telangectasica congenita (phacomatosis achromico-melano-marmorata)] or in the context of other skin (e.g., ataxia-telangiectasia and phacomatosis pigmentovascularis, PPV) or complex malformation phenotypes (e.g., microcephaly and dwarfism). Methods (I) Review of the existing literature; and (II) information on our personal experience (clinical, laboratory and imaging data) on new cases with cutis tricolor seen and followed-up at our institutions during years 2010–2016. Results The existing literature revealed 19 previous studies (35 cases) with pure cutaneous or syndromic cutis tricolor phenomena. Our personal experience included 5 unpublished patients (3 boys; 2 girls; currently aged 2 to 14 years) seen and followed-up at our Institutions in Italy who had: (I) skin manifestations of the cutis tricolor type (N=5); (II) skeletal abnormalities including small skull (n=2), obtuse angle of mandible (n=3), mild to moderate scoliosis (n=3), vertebral defects (n=3), and long bones bowing (n=3); mild psychomotor delay (n=3); epilepsy (n=2); anomalies of the corpus callosum (n=3); and cavum vergae (n =2). Conclusions This study further confirms and expands the overall phenotype of cutis tricolor. By literature review and personal experience we conclude that the skin abnormalities of the cutis tricolor type are stable over time; the skeletal defects are mild to moderate and do not progress or cause relevant orthopaedic complications; the neurological/behavioural phenotype does not progress and the paroxysmal events (when present) tend to decrease over time; there is a typical facial phenotype in some patients (long, elongated face, thick and brushy eyebrows, hypertelorism, deep nasal bridge with large bulbous nose and anteverted nostrils), which characterizes a somewhat distinct syndromic phenotype; some patients may develop early onset cataracts. The allelic dydymotic hypothesis of post-zygotic mutations likely involving the same gene loci could well explain the overall skin, bone, lens and nervous system phenomena of migration of different streaks of clones in the different tissues. PMID:27942472

Computation of term dominance in text documents

DOEpatents

Bauer, Travis L [Albuquerque, NM; Benz, Zachary O [Albuquerque, NM; Verzi, Stephen J [Albuquerque, NM

2012-04-24

An improved entropy-based term dominance metric useful for characterizing a corpus of text documents, and is useful for comparing the term dominance metrics of a first corpus of documents to a second corpus having a different number of documents.

76 FR 18391 - Safety Zone; Texas International Boat Show Power Boat Races; Corpus Christi Marina, Corpus...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-04

... temporary safety zone in the Corpus Christi, Texas for North American Tri-Hull Championship scheduled to take place during the Texas International Boat Show. The North American Tri-Hull Championship will...

A multicenter tractography study of deep white matter tracts in bipolar I disorder: psychotic features and interhemispheric disconnectivity.

PubMed

Sarrazin, Samuel; Poupon, Cyril; Linke, Julia; Wessa, Michèle; Phillips, Mary; Delavest, Marine; Versace, Amelia; Almeida, Jorge; Guevara, Pamela; Duclap, Delphine; Duchesnay, Edouard; Mangin, Jean-François; Le Dudal, Katia; Daban, Claire; Hamdani, Nora; D'Albis, Marc-Antoine; Leboyer, Marion; Houenou, Josselin

2014-04-01

Tractography studies investigating white matter (WM) abnormalities in patients with bipolar disorder have yielded heterogeneous results owing to small sample sizes. The small size limits their generalizability, a critical issue for neuroimaging studies of biomarkers of bipolar I disorder (BPI). To study WM abnormalities using whole-brain tractography in a large international multicenter sample of BPI patients and to compare these alterations between patients with or without a history of psychotic features during mood episodes. A cross-sectional, multicenter, international, Q-ball imaging tractography study comparing 118 BPI patients and 86 healthy control individuals. In addition, among the patient group, we compared those with and without a history of psychotic features. University hospitals in France, Germany, and the United States contributed participants. Participants underwent assessment using the Diagnostic Interview for Genetic Studies at the French sites or the Structured Clinical Interview for DSM-IV at the German and US sites. Diffusion-weighted magnetic resonance images were acquired using the same acquisition parameters and scanning hardware at each site. We reconstructed 22 known deep WM tracts using Q-ball imaging tractography and an automatized segmentation technique. Generalized fractional anisotropy values along each reconstructed WM tract. Compared with controls, BPI patients had significant reductions in mean generalized fractional anisotropy values along the body and the splenium of the corpus callosum, the left cingulum, and the anterior part of the left arcuate fasciculus when controlling for age, sex, and acquisition site (corrected for multiple testing). Patients with a history of psychotic features had a lower mean generalized fractional anisotropy value than those without along the body of the corpus callosum (corrected for multiple testing). In this multicenter sample, BPI patients had reduced WM integrity in interhemispheric, limbic, and arcuate WM tracts. Interhemispheric pathways are more disrupted in patients with than in those without psychotic symptoms. Together these results highlight the existence of an anatomic disconnectivity in BPI and further underscore a role for interhemispheric disconnectivity in the pathophysiological features of psychosis in BPI.

Impaired diffusion tensor imaging findings in the corpus callosum and cingulum may underlie impaired learning and memory abilities in systemic lupus erythematosus.

PubMed

Shapira-Lichter, I; Weinstein, M; Lustgarten, N; Ash, E; Litinsky, I; Aloush, V; Anouk, M; Caspi, D; Hendler, T; Paran, D

2016-10-01

Memory impairment is prevalent in systemic lupus erythematosus (SLE); however, its pathogenesis is unknown. In a previous functional magnetic resonance imaging (fMRI) study we demonstrated altered brain activity dynamics and less brain deactivation in patients with SLE as compared with healthy controls, when performing a learning and memory task. Our findings localized this impairment to the default mode network (DMN), and particularly to its anterior medial prefrontal cortex node. In addition, altered networking of the hippocampal subsystem of the DMN was seen in patients with SLE when performing this task, as well as atrophy of the left hippocampus. The present study aimed to search for a structural substrate for the altered recruitment pattern observed in fMRI studies using diffusion tensor imaging (DTI). Using DTI, we characterized brain diffusivity in 10 patients with SLE and nine healthy controls. Two tracts associated with the DMN were reconstructed: the corpus callosum (CC) and the cingulum bundle. The CC was segmented according to the Witelson segmentation scheme and the cingulum was segmented into superior and descending bundles. A significant increase in mean diffusivity (MD) was seen in patients with SLE without neuropsychiatric SLE (NPSLE) as compared with healthy controls in all five segments of the CC (segment 1: p = 0.043; segment 2: p = 0.005; segment 3: p = 0.003; segment 4: p = 0.012; segment 5: p = 0.023) as well as in the descending portion of the left cingulum bundle (p = 0.026). Increased MD values in the CC and the left cingulum may indicate impaired organization/reduced integrity of these tracts, which may underlie the abnormal pattern of brain activity recruitment of the DMN observed during a verbal learning and memory task. Taking into account the central role of the left hippocampus in verbal memory, the abnormal integrity of the left cingulum may contribute to the reduced performance of patients with SLE on verbal memory tasks. © The Author(s) 2016.

A Choice Reaction Time Index of Callosal Anatomical Homotopy

ERIC Educational Resources Information Center

Desjardins, Sameul; Braun, Claude M. J.; Achim, Andre; Roberge, Carl

2009-01-01

Tachistoscopically presented bilateral stimulus pairs not parallel to the meridian produced significantly longer RTs on a task requiring discrimination of shapes (Go/no-Go) than pairs emplaced symmetrically on each side of the meridian in Desjardins and Braun [Desjardins, S., & Braun, C. M. J. (2006). Homotopy and heterotopy and the bilateral…

Eribulin Mesylate and Gemcitabine Hydrochloride in Treating Patients With Metastatic Solid Tumors or Solid Tumors That Cannot be Removed by Surgery

ClinicalTrials.gov

2017-09-19

Adult Solid Neoplasm; Recurrent Ovarian Carcinoma; Recurrent Uterine Corpus Carcinoma; Stage III Ovarian Cancer; Stage III Uterine Corpus Cancer; Stage IV Ovarian Cancer; Stage IV Uterine Corpus Cancer

Enhancement of Phloem Exudation from Fraxinus uhdei Wenz. (Evergreen Ash) using Ethylenediaminetetraacetic Acid 1

PubMed Central

Costello, L. R.; Bassham, James A.; Calvin, Melvin

1982-01-01

Ethylenediaminetetraacetic acid (EDTA) enhanced the exudation of 14C-labeled assimilates from excised leaflets and whole plant specimens of Fraxinus uhdei Wenz. A 2 millimolar EDTA concentration was found to be most effective in promoting exudation from excised leaflets, while 10 millimolar EDTA was most effective in whole plants experiments. Exudation rate reached a maximum after 24 hours in both experiments. The continuous presence of EDTA throughout the treatment period was required for maximum exudation from excised leaflets. Stachyose, raffinose, verbascose, and sucrose were the principal compounds found to occur in exudate samples. These compounds are typically transported in sieve elements of various Fraxinus species suggesting the exudate was of phloem origin. Electron microscope studies of petiolule sieve plate pores from excised leaflets showed substantially less callose appearing after treatment with EDTA than after H2O treatment. It is suggested that EDTA enhances phloem exudation by inhibiting or reducing callose formation in sieve plate pores. The exudation enhancement technique described for whole plant specimens is suggested as a useful means of collecting phloem sap and studying translocation in woody plants. Images PMID:16662189

A network of genetic repression and derepression specifies projection fates in the developing neocortex.

PubMed

Srinivasan, Karpagam; Leone, Dino P; Bateson, Rosalie K; Dobreva, Gergana; Kohwi, Yoshinori; Kohwi-Shigematsu, Terumi; Grosschedl, Rudolf; McConnell, Susan K

2012-11-20

Neurons within each layer in the mammalian cortex have stereotypic projections. Four genes-Fezf2, Ctip2, Tbr1, and Satb2-regulate these projection identities. These genes also interact with each other, and it is unclear how these interactions shape the final projection identity. Here we show, by generating double mutants of Fezf2, Ctip2, and Satb2, that cortical neurons deploy a complex genetic switch that uses mutual repression to produce subcortical or callosal projections. We discovered that Tbr1, EphA4, and Unc5H3 are critical downstream targets of Satb2 in callosal fate specification. This represents a unique role for Tbr1, implicated previously in specifying corticothalamic projections. We further show that Tbr1 expression is dually regulated by Satb2 and Ctip2 in layers 2-5. Finally, we show that Satb2 and Fezf2 regulate two disease-related genes, Auts2 (Autistic Susceptibility Gene2) and Bhlhb5 (mutated in Hereditary Spastic Paraplegia), providing a molecular handle to investigate circuit disorders in neurodevelopmental diseases.

The tolerance of feline corpus and cauda spermatozoa to cryostress.

PubMed

Kunkitti, Panisara; Bergqvist, Ann-Sofi; Sjunnesson, Ylva; Johannisson, Anders; Axnér, Eva

2016-02-01

Epididymal sperm preservation can be used to avoid the total loss of genetic material in threatened species. Spermatozoa from the corpus, as from the cauda, are motile and can undergo capacitation. Thus, they can potentially be preserved for assisted reproductive technologies. However, cryopreservation of spermatozoa has a direct detrimental effect on sperm quality. The aim of this study was to compare the chromatin stability and the survival rate of spermatozoa from the corpus and cauda epididymis after cryopreservation. Epididymal spermatozoa were collected and cryopreserved from the corpus and cauda of 12 domestic cats. Sperm motility, progressive motility, membrane integrity, acrosome integrity, and DNA integrity were evaluated before and after freezing thawing. The average total number of spermatozoa collected from the corpus was lower (10.2 × 10(6) ± 7.4) than that from the cauda epididymis (24.9 × 10(6) ± 14.4; P = 0.005). The percentage of spermatozoa with intact DNA did not differ significantly whether it was collected from the corpus or cauda regions and did not decrease after freezing thawing in either region. However, motility of spermatozoa from both regions was affected by the freezing thawing process with a significant decline in motility after thaw compared with fresh spermatozoa. A significant difference in the percentage of motile sperm between the corpus and cauda was observed after the freezing thawing process (P < 0.001). Although sperm motility was lower in postthaw spermatozoa from the corpus epididymidis than from the cauda, the rate of the reduction did not differ between regions. This study indicates that the cryopreservation process does not have a negative effect on chromatin stability of feline epididymal spermatozoa. Spermatozoa from the corpus region have a similar freezability as spermatozoa from the cauda region. Therefore, preservation of spermatozoa from the corpus and the cauda epididymidis might be of value in preserving genetic material from endangered or valuable felids. Copyright © 2016 Elsevier Inc. All rights reserved.

Effects of insulin resistance on white matter microstructure in middle-aged and older adults

PubMed Central

Coutu, Jean-Philippe; Rosas, H. Diana; Salat, David H.

2014-01-01

Objective: To investigate the potential relationship between insulin resistance (IR) and white matter (WM) microstructure using diffusion tensor imaging in cognitively healthy middle-aged and older adults. Methods: Diffusion tensor imaging was acquired from 127 individuals (age range 41–86 years). IR was evaluated by the homeostasis model assessment of IR (HOMA-IR). Participants were divided into 2 groups based on HOMA-IR values: “high HOMA-IR” (≥2.5, n = 27) and “low HOMA-IR” (<2.5, n = 100). Cross-sectional voxel-based comparisons were performed using Tract-Based Spatial Statistics and anatomically defined regions of interest analysis. Results: The high HOMA-IR group demonstrated decreased axial diffusivity broadly throughout the cerebral WM in areas such as the corpus callosum, corona radiata, cerebral peduncle, posterior thalamic radiation, and right superior longitudinal fasciculus, and WM underlying the frontal, parietal, and temporal lobes, as well as decreased fractional anisotropy in the body and genu of corpus callosum and parts of the superior and anterior corona radiata, compared with the low HOMA-IR group, independent of age, WM signal abnormality volume, and antihypertensive medication status. These regions additionally demonstrated linear associations between diffusion measures and HOMA-IR across all subjects, with higher HOMA-IR values being correlated with lower axial diffusivity. Conclusions: In generally healthy adults, greater IR is associated with alterations in WM tissue integrity. These cross-sectional findings suggest that IR contributes to WM microstructural alterations in middle-aged and older adults. PMID:24771537

Spatial patterns of whole brain grey and white matter injury in patients with occult spastic diplegic cerebral palsy.

PubMed

Mu, Xuetao; Nie, Binbin; Wang, Hong; Duan, Shaofeng; Zhang, Zan; Dai, Guanghui; Ma, Qiaozhi; Shan, Baoci; Ma, Lin

2014-01-01

Spastic diplegic cerebral palsy (SDCP) is a common type of cerebral palsy (CP), which presents as a group of motor-impairment syndromes. Previous conventional MRI studies have reported abnormal structural changes in SDCP, such as periventricular leucomalacia. However, there are roughly 27.8% SDCP patients presenting normal appearance in conventional MRI, which were considered as occult SDCP. In this study, sixteen patients with occult SDCP and 16 age- and sex-matched healthy control subjects were collected and the data were acquired on a 3T MR system. We applied voxel-based morphometry (VBM) and tract-based spatial statistics (TBSS) analysis to investigate whole brain grey and white matter injury in occult SDCP. By using VBM method, the grey matter volume reduction was revealed in the bilateral basal ganglia regions, thalamus, insula, and left cerebral peduncle, whereas the white matter atrophy was found to be located in the posterior part of corpus callosum and right posterior corona radiata in the occult SDCP patients. By using TBSS, reduced fractional anisotropy (FA) values were detected in multiple white matter regions, including bilateral white matter tracts in prefrontal lobe, temporal lobe, internal and external capsule, corpus callosum, cingulum, thalamus, brainstem and cerebellum. Additionally, several regions of white matter tracts injury were found to be significantly correlated with motor dysfunction. These results collectively revealed the spatial patterns of whole brain grey and white matter injury in occult SDCP.

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.

Limbic and corpus callosum aberrations in adolescents with bipolar disorder: a tract-based spatial statistics analysis.

PubMed

Barnea-Goraly, Naama; Chang, Kiki D; Karchemskiy, Asya; Howe, Meghan E; Reiss, Allan L

2009-08-01

Bipolar disorder (BD) is a common and debilitating condition, often beginning in adolescence. Converging evidence from genetic and neuroimaging studies indicates that white matter abnormalities may be involved in BD. In this study, we investigated white matter structure in adolescents with familial bipolar disorder using diffusion tensor imaging (DTI) and a whole brain analysis. We analyzed DTI images using tract-based spatial statistics (TBSS), a whole-brain voxel-by-voxel analysis, to investigate white matter structure in 21 adolescents with BD, who also were offspring of at least one parent with BD, and 18 age- and IQ-matched control subjects. Fractional anisotropy (FA; a measure of diffusion anisotropy), trace values (average diffusivity), and apparent diffusion coefficient (ADC; a measure of overall diffusivity) were used as variables in this analysis. In a post hoc analysis, we correlated between FA values, behavioral measures, and medication exposure. Adolescents with BD had lower FA values than control subjects in the fornix, the left mid-posterior cingulate gyrus, throughout the corpus callosum, in fibers extending from the fornix to the thalamus, and in parietal and occipital corona radiata bilaterally. There were no significant between-group differences in trace or ADC values and no significant correlation between behavioral measures, medication exposure, and FA values. Significant white matter tract alterations in adolescents with BD were observed in regions involved in emotional, behavioral, and cognitive regulation. These results suggest that alterations in white matter are present early in the course of disease in familial BD.

A new heterozygous mutation of the FOXL2 gene is associated with a large ovarian cyst and ovarian dysfunction in an adolescent girl with blepharophimosis/ptosis/epicanthus inversus syndrome.

PubMed

Raile, K; Stobbe, H; Tröbs, R B; Kiess, W; Pfäffle, R

2005-09-01

Blepharophimosis/ptosis/epicanthus inversus syndrome (BPES), an autosomal dominant syndrome in which eyelid malformation is associated with (type I BPES) or without premature ovarian failure (type II BPES). Mutations of a putative winged helix/forkhead transcription factor FOXL2 account for both types of BPES. We report on a 16-year-old adolescent girl with blepharophimosis and ptosis. Subsequently she developed oligomenorrhea, secondary amenorrhea for 6 months, and an extremely large cyst of one ovary. The cyst contained 8 l of cyst fluid and histopathology displayed a large corpus luteum cyst. Following laparotomy, gonadotropin levels were elevated (LH 17.2 U/l, FSH 29.4 U/l) and estradiol levels decreased (67 pmol/l). Because of clinical aspects of BPES and abnormal ovarian function we suspected a mutation of her FOXL2 gene and found a new in-frame mutation (904_939dup36) on one allele, leading to a 12 alanine expansion within the polyalanine domain. We conclude that the FOXL2 mutation 904_939dup36 may account not only for blepharophimosis and ptosis but also for ovarian dysfunction and growth of the large corpus luteum cyst. In contrast to known FOXL2 mutations with polyalanine expansions and association with BPES type II, clinical aspects of our girl may indicate some degree of ovarian dysfunction that might finally lead to BPES type I with premature ovarian failure.

Nudging oligodendrocyte intrinsic signaling to remyelinate and repair: Estrogen receptor ligand effects.

PubMed

Khalaj, Anna J; Hasselmann, Jonathan; Augello, Catherine; Moore, Spencer; Tiwari-Woodruff, Seema K

2016-06-01

Demyelination in multiple sclerosis (MS) leads to significant, progressive axonal and neuronal degeneration. Currently existing immunosuppressive and immunomodulatory therapies alleviate MS symptoms and slow, but fail to prevent or reverse, disease progression. Restoration of damaged myelin sheath by replenishment of mature oligodendrocytes (OLs) should not only restore saltatory axon conduction, but also provide a major boost to axon survival. Our previous work has shown that therapeutic treatment with the modestly selective generic estrogen receptor (ER) β agonist diarylpropionitrile (DPN) confers functional neuroprotection in a chronic experimental autoimmune encephalomyelitis (EAE) mouse model of MS by stimulating endogenous remyelination. Recently, we found that the more potent, selective ERβ agonist indazole-chloride (Ind-Cl) improves clinical disease and motor performance. Importantly, electrophysiological measures revealed improved corpus callosal conduction and reduced axon refractoriness. This Ind-Cl treatment-induced functional remyelination was attributable to increased OL progenitor cell (OPC) and mature OL numbers. At the intracellular signaling level, transition of early to late OPCs requires ERK1/2 signaling, and transition of immature to mature OLs requires mTOR signaling; thus, the PI3K/Akt/mTOR pathway plays a major role in the late stages of OL differentiation and myelination. Indeed, therapeutic treatment of EAE mice with various ERβ agonists results in increased brain-derived neurotrophic factor (BDNF) and phosphorylated (p) Akt and p-mTOR levels. It is notable that while DPN's neuroprotective effects occur in the presence of peripheral and central inflammation, Ind-Cl is directly neuroprotective, as demonstrated by remyelination effects in the cuprizone-induced demyelination model, as well as immunomodulatory. Elucidating the mechanisms by which ER agonists and other directly remyelinating agents modulate endogenous OPC and OL regulatory signaling is critical to the development of effective remyelinating drugs. The discovery of signaling targets to induce functional remyelination will valuably contribute to the treatment of demyelinating neurological diseases, including MS, stroke, and traumatic brain and spinal cord injury. Published by Elsevier Ltd.

Nudging Oligodendrocyte Intrinsic Signaling to Remyelinate and Repair: Estrogen Receptor Ligand Effects

PubMed Central

Khalaj, Anna J.; Hasselmann, Jonathan; Augello, Catherine; Moore, Spencer; Tiwari-Woodruff, Seema K.

2017-01-01

Demyelination in multiple sclerosis (MS) leads to significant, progressive axonal and neuronal degeneration. Currently existing immunosuppressive and immunomodulatory therapies alleviate MS symptoms and slow, but fail to prevent or reverse, disease progression. Restoration of damaged myelin sheath by replenishment of mature oligodendrocytes (OLs) should not only restore saltatory axon conduction, but also provide a major boost to axon survival. Our previous work has shown that therapeutic treatment with the modestly selective generic estrogen receptor (ER) β agonist diarylpropionitrile (DPN) confers functional neuroprotection in a chronic experimental autoimmune encephalomyelitis (EAE) mouse model of MS by stimulating endogenous myelination. Recently, we found that the more potent, selective ERβ agonist indazole-chloride (Ind-Cl) improves clinical disease and motor performance. Importantly, electrophysiological measures revealed improved corpus callosal conduction and reduced axon refractoriness. This Ind-Cl treatment-induced functional remyelination was attributable to increased OL progenitor cell (OPC) and mature OL numbers. At the intracellular signaling level, transition of early to late OPCs requires Erk1/2 signaling, and transition of immature to mature OLs requires mTOR signaling; thus, the PI3K/Akt/mTOR pathway plays a major role in the late stages of OL differentiation and myelination. Indeed, therapeutic treatment of EAE mice with various ERβ agonists results in increased brain-derived neurotrophic factor (BDNF) and phosphorylated (p) Akt and p-mTOR levels. It is notable that while DPN’s neuroprotective effects occur in the presence of peripheral and central inflammation, Ind-Cl is directly neuroprotective, as demonstrated by remyelination effects in the cuprizone-induced demyelination model, as well as anti-inflammatory. Elucidating the mechanisms by which ER agonists and other directly remyelinating agents modulate endogenous OPC and OL regulatory signaling is critical to the development of effective remyelinating drugs. The discovery of signaling targets to induce functional remyelination will valuably contribute to the treatment of demyelinating neurological diseases, including MS, stroke, and traumatic brain and spinal cord injury. PMID:26776441

TwiMed: Twitter and PubMed Comparable Corpus of Drugs, Diseases, Symptoms, and Their Relations

PubMed Central

Miyao, Yusuke; Collier, Nigel

2017-01-01

Background Work on pharmacovigilance systems using texts from PubMed and Twitter typically target at different elements and use different annotation guidelines resulting in a scenario where there is no comparable set of documents from both Twitter and PubMed annotated in the same manner. Objective This study aimed to provide a comparable corpus of texts from PubMed and Twitter that can be used to study drug reports from these two sources of information, allowing researchers in the area of pharmacovigilance using natural language processing (NLP) to perform experiments to better understand the similarities and differences between drug reports in Twitter and PubMed. Methods We produced a corpus comprising 1000 tweets and 1000 PubMed sentences selected using the same strategy and annotated at entity level by the same experts (pharmacists) using the same set of guidelines. Results The resulting corpus, annotated by two pharmacists, comprises semantically correct annotations for a set of drugs, diseases, and symptoms. This corpus contains the annotations for 3144 entities, 2749 relations, and 5003 attributes. Conclusions We present a corpus that is unique in its characteristics as this is the first corpus for pharmacovigilance curated from Twitter messages and PubMed sentences using the same data selection and annotation strategies. We believe this corpus will be of particular interest for researchers willing to compare results from pharmacovigilance systems (eg, classifiers and named entity recognition systems) when using data from Twitter and from PubMed. We hope that given the comprehensive set of drug names and the annotated entities and relations, this corpus becomes a standard resource to compare results from different pharmacovigilance studies in the area of NLP. PMID:28468748

TwiMed: Twitter and PubMed Comparable Corpus of Drugs, Diseases, Symptoms, and Their Relations.

PubMed

Alvaro, Nestor; Miyao, Yusuke; Collier, Nigel

2017-05-03

Work on pharmacovigilance systems using texts from PubMed and Twitter typically target at different elements and use different annotation guidelines resulting in a scenario where there is no comparable set of documents from both Twitter and PubMed annotated in the same manner. This study aimed to provide a comparable corpus of texts from PubMed and Twitter that can be used to study drug reports from these two sources of information, allowing researchers in the area of pharmacovigilance using natural language processing (NLP) to perform experiments to better understand the similarities and differences between drug reports in Twitter and PubMed. We produced a corpus comprising 1000 tweets and 1000 PubMed sentences selected using the same strategy and annotated at entity level by the same experts (pharmacists) using the same set of guidelines. The resulting corpus, annotated by two pharmacists, comprises semantically correct annotations for a set of drugs, diseases, and symptoms. This corpus contains the annotations for 3144 entities, 2749 relations, and 5003 attributes. We present a corpus that is unique in its characteristics as this is the first corpus for pharmacovigilance curated from Twitter messages and PubMed sentences using the same data selection and annotation strategies. We believe this corpus will be of particular interest for researchers willing to compare results from pharmacovigilance systems (eg, classifiers and named entity recognition systems) when using data from Twitter and from PubMed. We hope that given the comprehensive set of drug names and the annotated entities and relations, this corpus becomes a standard resource to compare results from different pharmacovigilance studies in the area of NLP. ©Nestor Alvaro, Yusuke Miyao, Nigel Collier. Originally published in JMIR Public Health and Surveillance (http://publichealth.jmir.org), 03.05.2017.

The Brazilian Portuguese Lexicon: An Instrument for Psycholinguistic Research

PubMed Central

Estivalet, Gustavo L.; Meunier, Fanny

2015-01-01

In this article, we present the Brazilian Portuguese Lexicon, a new word-based corpus for psycholinguistic and computational linguistic research in Brazilian Portuguese. We describe the corpus development, the specific characteristics on the internet site and database for user access. We also perform distributional analyses of the corpus and comparisons to other current databases. Our main objective was to provide a large, reliable, and useful word-based corpus with a dynamic, easy-to-use, and intuitive interface with free internet access for word and word-criteria searches. We used the Núcleo Interinstitucional de Linguística Computacional’s corpus as the basic data source and developed the Brazilian Portuguese Lexicon by deriving and adding metalinguistic and psycholinguistic information about Brazilian Portuguese words. We obtained a final corpus with more than 30 million word tokens, 215 thousand word types and 25 categories of information about each word. This corpus was made available on the internet via a free-access site with two search engines: a simple search and a complex search. The simple engine basically searches for a list of words, while the complex engine accepts all types of criteria in the corpus categories. The output result presents all entries found in the corpus with the criteria specified in the input search and can be downloaded as a.csv file. We created a module in the results that delivers basic statistics about each search. The Brazilian Portuguese Lexicon also provides a pseudoword engine and specific tools for linguistic and statistical analysis. Therefore, the Brazilian Portuguese Lexicon is a convenient instrument for stimulus search, selection, control, and manipulation in psycholinguistic experiments, as also it is a powerful database for computational linguistics research and language modeling related to lexicon distribution, functioning, and behavior. PMID:26630138

The Brazilian Portuguese Lexicon: An Instrument for Psycholinguistic Research.

PubMed

Estivalet, Gustavo L; Meunier, Fanny

2015-01-01

In this article, we present the Brazilian Portuguese Lexicon, a new word-based corpus for psycholinguistic and computational linguistic research in Brazilian Portuguese. We describe the corpus development, the specific characteristics on the internet site and database for user access. We also perform distributional analyses of the corpus and comparisons to other current databases. Our main objective was to provide a large, reliable, and useful word-based corpus with a dynamic, easy-to-use, and intuitive interface with free internet access for word and word-criteria searches. We used the Núcleo Interinstitucional de Linguística Computacional's corpus as the basic data source and developed the Brazilian Portuguese Lexicon by deriving and adding metalinguistic and psycholinguistic information about Brazilian Portuguese words. We obtained a final corpus with more than 30 million word tokens, 215 thousand word types and 25 categories of information about each word. This corpus was made available on the internet via a free-access site with two search engines: a simple search and a complex search. The simple engine basically searches for a list of words, while the complex engine accepts all types of criteria in the corpus categories. The output result presents all entries found in the corpus with the criteria specified in the input search and can be downloaded as a.csv file. We created a module in the results that delivers basic statistics about each search. The Brazilian Portuguese Lexicon also provides a pseudoword engine and specific tools for linguistic and statistical analysis. Therefore, the Brazilian Portuguese Lexicon is a convenient instrument for stimulus search, selection, control, and manipulation in psycholinguistic experiments, as also it is a powerful database for computational linguistics research and language modeling related to lexicon distribution, functioning, and behavior.

The CHEMDNER corpus of chemicals and drugs and its annotation principles.

PubMed

Krallinger, Martin; Rabal, Obdulia; Leitner, Florian; Vazquez, Miguel; Salgado, David; Lu, Zhiyong; Leaman, Robert; Lu, Yanan; Ji, Donghong; Lowe, Daniel M; Sayle, Roger A; Batista-Navarro, Riza Theresa; Rak, Rafal; Huber, Torsten; Rocktäschel, Tim; Matos, Sérgio; Campos, David; Tang, Buzhou; Xu, Hua; Munkhdalai, Tsendsuren; Ryu, Keun Ho; Ramanan, S V; Nathan, Senthil; Žitnik, Slavko; Bajec, Marko; Weber, Lutz; Irmer, Matthias; Akhondi, Saber A; Kors, Jan A; Xu, Shuo; An, Xin; Sikdar, Utpal Kumar; Ekbal, Asif; Yoshioka, Masaharu; Dieb, Thaer M; Choi, Miji; Verspoor, Karin; Khabsa, Madian; Giles, C Lee; Liu, Hongfang; Ravikumar, Komandur Elayavilli; Lamurias, Andre; Couto, Francisco M; Dai, Hong-Jie; Tsai, Richard Tzong-Han; Ata, Caglar; Can, Tolga; Usié, Anabel; Alves, Rui; Segura-Bedmar, Isabel; Martínez, Paloma; Oyarzabal, Julen; Valencia, Alfonso

2015-01-01

The automatic extraction of chemical information from text requires the recognition of chemical entity mentions as one of its key steps. When developing supervised named entity recognition (NER) systems, the availability of a large, manually annotated text corpus is desirable. Furthermore, large corpora permit the robust evaluation and comparison of different approaches that detect chemicals in documents. We present the CHEMDNER corpus, a collection of 10,000 PubMed abstracts that contain a total of 84,355 chemical entity mentions labeled manually by expert chemistry literature curators, following annotation guidelines specifically defined for this task. The abstracts of the CHEMDNER corpus were selected to be representative for all major chemical disciplines. Each of the chemical entity mentions was manually labeled according to its structure-associated chemical entity mention (SACEM) class: abbreviation, family, formula, identifier, multiple, systematic and trivial. The difficulty and consistency of tagging chemicals in text was measured using an agreement study between annotators, obtaining a percentage agreement of 91. For a subset of the CHEMDNER corpus (the test set of 3,000 abstracts) we provide not only the Gold Standard manual annotations, but also mentions automatically detected by the 26 teams that participated in the BioCreative IV CHEMDNER chemical mention recognition task. In addition, we release the CHEMDNER silver standard corpus of automatically extracted mentions from 17,000 randomly selected PubMed abstracts. A version of the CHEMDNER corpus in the BioC format has been generated as well. We propose a standard for required minimum information about entity annotations for the construction of domain specific corpora on chemical and drug entities. The CHEMDNER corpus and annotation guidelines are available at: http://www.biocreative.org/resources/biocreative-iv/chemdner-corpus/.

The CHEMDNER corpus of chemicals and drugs and its annotation principles

PubMed Central

2015-01-01

The automatic extraction of chemical information from text requires the recognition of chemical entity mentions as one of its key steps. When developing supervised named entity recognition (NER) systems, the availability of a large, manually annotated text corpus is desirable. Furthermore, large corpora permit the robust evaluation and comparison of different approaches that detect chemicals in documents. We present the CHEMDNER corpus, a collection of 10,000 PubMed abstracts that contain a total of 84,355 chemical entity mentions labeled manually by expert chemistry literature curators, following annotation guidelines specifically defined for this task. The abstracts of the CHEMDNER corpus were selected to be representative for all major chemical disciplines. Each of the chemical entity mentions was manually labeled according to its structure-associated chemical entity mention (SACEM) class: abbreviation, family, formula, identifier, multiple, systematic and trivial. The difficulty and consistency of tagging chemicals in text was measured using an agreement study between annotators, obtaining a percentage agreement of 91. For a subset of the CHEMDNER corpus (the test set of 3,000 abstracts) we provide not only the Gold Standard manual annotations, but also mentions automatically detected by the 26 teams that participated in the BioCreative IV CHEMDNER chemical mention recognition task. In addition, we release the CHEMDNER silver standard corpus of automatically extracted mentions from 17,000 randomly selected PubMed abstracts. A version of the CHEMDNER corpus in the BioC format has been generated as well. We propose a standard for required minimum information about entity annotations for the construction of domain specific corpora on chemical and drug entities. The CHEMDNER corpus and annotation guidelines are available at: http://www.biocreative.org/resources/biocreative-iv/chemdner-corpus/ PMID:25810773

Cell wall matrix polysaccharide distribution and cortical microtubule organization: two factors controlling mesophyll cell morphogenesis in land plants

PubMed Central

Sotiriou, P.; Giannoutsou, E.; Panteris, E.; Apostolakos, P.; Galatis, B.

2016-01-01

Background and aims This work investigates the involvement of local differentiation of cell wall matrix polysaccharides and the role of microtubules in the morphogenesis of mesophyll cells (MCs) of three types (lobed, branched and palisade) in the dicotyledon Vigna sinensis and the fern Asplenium nidus. Methods Homogalacturonan (HGA) epitopes recognized by the 2F4, JIM5 and JIM7 antibodies and callose were immunolocalized in hand-made leaf sections. Callose was also stained with aniline blue. We studied microtubule organization by tubulin immunofluorescence and transmission electron microscopy. Results In both plants, the matrix cell wall polysaccharide distribution underwent definite changes during MC differentiation. Callose constantly defined the sites of MC contacts. The 2F4 HGA epitope in V. sinensis first appeared in MC contacts but gradually moved towards the cell wall regions facing the intercellular spaces, while in A. nidus it was initially localized at the cell walls delimiting the intercellular spaces, but finally shifted to MC contacts. In V. sinensis, the JIM5 and JIM7 HGA epitopes initially marked the cell walls delimiting the intercellular spaces and gradually shifted in MC contacts, while in A. nidus they constantly enriched MC contacts. In all MC types examined, the cortical microtubules played a crucial role in their morphogenesis. In particular, in palisade MCs, cortical microtubule helices, by controlling cellulose microfibril orientation, forced these MCs to acquire a truncated cone-like shape. Unexpectedly in V. sinensis, the differentiation of colchicine-affected MCs deviated completely, since they developed a cell wall ingrowth labyrinth, becoming transfer-like cells. Conclusions The results of this work and previous studies on Zea mays (Giannoutsou et al., Annals of Botany 2013; 112: 1067–1081) revealed highly controlled local cell wall matrix differentiation in MCs of species belonging to different plant groups. This, in coordination with microtubule-dependent cellulose microfibril alignment, spatially controlled cell wall expansion, allowing MCs to acquire their particular shape. PMID:26802013

Second Metatarsal Transfer Lesions Due to First Metatarsal Shortening After Distal Chevron Metatarsal Osteotomy for Hallux Valgus.

PubMed

Ahn, Jiyong; Lee, Ho Seong; Seo, Jeong Ho; Kim, Ju Yeong

2016-06-01

The first metatarsal bone can shorten after a distal chevron metatarsal osteotomy (DCMO). This shortening can result in a postoperative second metatarsal transfer lesion. The aim of the present study was to investigate the occurrence of second metatarsal transfer lesions after DCMO. This study involved 185 feet (138 patients), with hallux valgus (HV) deformity, treated with DCMO with Akin osteotomy. The mean patient age was 51.7 years (range, 21 to 74). Patients were followed for an average of 28 months, between June 2004 and June 2010. We measured the length of first metatarsal relative to second metatarsal preoperatively and postoperatively, using Morton's and Hardy-Clapham's methods. A second metatarsal transfer lesion was defined as a newly developed lesion, including metatarsalgia, a painful callosity, or a painless callosity, which was not present prior to the DCMO. The relation of the shortened first metatarsal after DCMO with the occurrence of second metatarsal transfer lesion was evaluated. Second metatarsal transfer lesions (painless callosity) developed in 5 feet (2.7%) of 185 feet. Twenty-four preoperative second metatarsal lesions were improved postoperatively. The median shortening of the first metatarsal bone after DCMO was 0.6 mm according to Morton's method (range, -6.4 to 6.4), and 1.9 according to Hardy-Clapham's method (range, -5.8 to 5.8). According to the extent of first metatarsal shortening after DCMO by Hardy-Clapham's method and Morton's method, there was no significant difference of the occurrence of second transfer metatarsal lesions (P = .259 and P = .176, respectively). In our study, second metatarsal transfer lesions developed in 2.7% of feet after DCMO. The occurrence of second metatarsal transfer lesions did not appear to be correlated with the degree of first metatarsal shortening in cases with less than 5.8 mm shortening. Level IV, retrospective case series. © The Author(s) 2016.

Sugarcane smut: shedding light on the development of the whip-shaped sorus

PubMed Central

Marques, João Paulo R.; Appezzato-da-Glória, Beatriz; Piepenbring, Meike; Massola Jr, Nelson S.; Monteiro-Vitorello, Claudia B.

2017-01-01

Background and Aims Sugarcane smut is caused by the fungus Sporisorium scitamineum (Ustilaginales/Ustilaginomycotina/Basidiomycota), which is responsible for losses in sugarcane production worldwide. Infected plants show a profound metabolic modification resulting in the development of a whip-shaped structure (sorus) composed of a mixture of plant tissues and fungal hyphae. Within this structure, ustilospores develop and disseminate the disease. Despite the importance of this disease, a detailed histopathological analysis of the plant–pathogen interaction is lacking. Methods The whip-shaped sorus was investigated using light microscopy, scanning and transmission electron microscopy, histochemical tests and epifluorescence microscopy coupled with deconvolution. Key Results Sorus growth is mediated by intercalary meristem activity at the base of the sorus, where the fungus causes partial host cell wall degradation and formation of intercellular spaces. Sporogenesis in S. scitamineum is thallic, with ustilospore initials in intercalary or terminal positions, and mostly restricted to the base of the sorus. Ustilospore maturation is centrifugal in relation to the ground parenchyma and occurs throughout the sorus median region. At the apex of the sorus, the fungus produces sterile cells and promotes host cell detachment. Hyphae are present throughout the central axis of the sorus (columella). The plant cell produces callose around the intracellular hyphae as well as inside the papillae at the infection site. Conclusions The ontogeny of the whip-shaped sorus suggests that the fungus can cause the acropetal growth in the intercalary meristem. The sporogenesis of S. scitamineum was described in detail, demonstrating that the spores are formed exclusively at the base of the whip. Light was also shed on the nature of the sterile cells. The presence of the fungus alters the host cell wall composition, promotes its degradation and causes the release of some peripheral cells of the sorus. Finally, callose was observed around fungal hyphae in infected cells, suggesting that deposition of callose by the host may act as a structural response to fungal infection. PMID:27568298

Diffusion Tensor Imaging of Frontal White Matter and Executive Functioning in Cocaine-Exposed Children

PubMed Central

Warner, Tamara Duckworth; Behnke, Marylou; Eyler, Fonda Davis; Padgett, Kyle; Leonard, Christiana; Hou, Wei; Garvan, Cynthia Wilson; Schmalfuss, Ilona M.; Blackband, Stephen J.

2011-01-01

BACKGROUND Although animal studies have demonstrated frontal white matter and behavioral changes resulting from prenatal cocaine exposure, no human studies have associated neuropsychological deficits in attention and inhibition with brain structure. We used diffusion tensor imaging to investigate frontal white matter integrity and executive functioning in cocaine-exposed children. METHODS Six direction diffusion tensor images were acquired using a Siemens 3T scanner with a spin-echo echo-planar imaging pulse sequence on right-handed cocaine-exposed (n = 28) and sociodemographically similar non-exposed children (n = 25; mean age: 10.6 years) drawn from a prospective, longitudinal study. Average diffusion and fractional anisotropy were measured in the left and right frontal callosal and frontal projection fibers. Executive functioning was assessed using two well-validated neuropsychological tests (Stroop color-word test and Trail Making Test). RESULTS Cocaine-exposed children showed significantly higher average diffusion in the left frontal callosal and right frontal projection fibers. Cocaine-exposed children were also significantly slower on a visual-motor set-shifting task with a trend toward lower scores on a verbal inhibition task. Controlling for gender and intelligence, average diffusion in the left frontal callosal fibers was related to prenatal exposure to alcohol and marijuana and an interaction between cocaine and marijuana exposure. Performance on the visual-motor set-shifting task was related to prenatal cocaine exposure and an interaction between cocaine and tobacco exposure. Significant correlations were found between test performance and fractional anisotropy in areas of the frontal white matter. CONCLUSIONS Prenatal cocaine exposure, alone and in combination with exposure to other drugs, is associated with slightly poorer executive functioning and subtle microstructural changes suggesting less mature development of frontal white matter pathways. The relative contribution of postnatal environmental factors, including characteristics of the caregiving environment and stressors associated with poverty and out-of-home placement, on brain development and behavioral functioning in polydrug-exposed children awaits further research. PMID:17079574

Diffusion tensor imaging of frontal white matter and executive functioning in cocaine-exposed children.

PubMed

Warner, Tamara Duckworth; Behnke, Marylou; Eyler, Fonda Davis; Padgett, Kyle; Leonard, Christiana; Hou, Wei; Garvan, Cynthia Wilson; Schmalfuss, Ilona M; Blackband, Stephen J

2006-11-01

Although animal studies have demonstrated frontal white matter and behavioral changes resulting from prenatal cocaine exposure, no human studies have associated neuropsychological deficits in attention and inhibition with brain structure. We used diffusion tensor imaging to investigate frontal white matter integrity and executive functioning in cocaine-exposed children. Six direction diffusion tensor images were acquired using a Siemens 3T scanner with a spin-echo echo-planar imaging pulse sequence on right-handed cocaine-exposed (n = 28) and sociodemographically similar non-exposed children (n = 25; mean age: 10.6 years) drawn from a prospective, longitudinal study. Average diffusion and fractional anisotropy were measured in the left and right frontal callosal and frontal projection fibers. Executive functioning was assessed using two well-validated neuropsychological tests (Stroop color-word test and Trail Making Test). Cocaine-exposed children showed significantly higher average diffusion in the left frontal callosal and right frontal projection fibers. Cocaine-exposed children were also significantly slower on a visual-motor set-shifting task with a trend toward lower scores on a verbal inhibition task. Controlling for gender and intelligence, average diffusion in the left frontal callosal fibers was related to prenatal exposure to alcohol and marijuana and an interaction between cocaine and marijuana exposure. Performance on the visual-motor set-shifting task was related to prenatal cocaine exposure and an interaction between cocaine and tobacco exposure. Significant correlations were found between test performance and fractional anisotropy in areas of the frontal white matter. Prenatal cocaine exposure, alone and in combination with exposure to other drugs, is associated with slightly poorer executive functioning and subtle microstructural changes suggesting less mature development of frontal white matter pathways. The relative contribution of postnatal environmental factors, including characteristics of the caregiving environment and stressors associated with poverty and out-of-home placement, on brain development and behavioral functioning in polydrug-exposed children awaits further research.

[A case of a collision tumor comprising mucosa-associated lymphoid tissue lymphoma and early gastric cancer].

PubMed

Isosaka, Mai; Adachi, Takeya; Iida, Tomoya; Mitsuhashi, Kei; Tanaka, Michihiro; Kondou, Yoshihiro; Suzuki, Takashi; Tanuma, Tokuma; Kasai, Kiyoshi

2014-07-01

A 60-year-old woman underwent upper gastrointestinal endoscopy for an abnormality identified during routine examination. The lower gastric corpus showed a type 0-I elevated lesion with a faded mucosa and an area of converging mucosal folds in contact with the lesion. Biopsy indicated the former to be a high-grade adenoma and the latter to be a mucosa-associated lymphoid tissue (MALT) lymphoma. At the same time, Helicobacter pylori infection was diagnosed. Eradication therapy was administered to manage the MALT lymphoma; this resulted in improvement after 3 months. Endoscopic submucosal dissection was performed for the elevated lesion, and subsequent histopathology showed contact between the MALT lymphoma and gastric cancer. Therefore, the patient was diagnosed with a collision tumor. Concurrent cancers are increasingly reported and should be considered during examination.

Immunohistochemical characterization of endometrial carcinomas: endometrioid, serous and clear cell adenocarcinomas in association with genetic analysis.

PubMed

Yasuda, Masanori

2014-12-01

Developments in immunohistochemistry, which are closely linked with the advances in the analyses of genetic abnormalities and their associated molecular disorders as early and late histogenetic events, have contributed greatly to the improvement of pathological diagnostic confirmation and validation. Immunohistochemistry has also generated great benefit to the innovation of therapeutic strategies for various kinds of cancers. In this article, the three representative histological types of corpus cancer, namely, endometrioid adenocarcinoma, serous adenocarcinoma and clear cell adenocarcinoma, will be histologically approached in association with their immunohistochemical profiles as well as genetic disorders. First, the focus will be on 'Conventional/prototypic features,' followed by 'Controversy over conventional histological subclassification,' and subsequently 'Tumorigenesis and re-subclassification'. © 2014 The Author. Journal of Obstetrics and Gynaecology Research © 2014 Japan Society of Obstetrics and Gynecology.

Use of "Google Scholar" in Corpus-Driven EAP Research

ERIC Educational Resources Information Center

Brezina, Vaclav

2012-01-01

This primarily methodological article makes a proposition for linguistic exploration of textual resources available through the "Google Scholar" search engine. These resources ("Google Scholar virtual corpus") are significantly larger than any existing corpus of academic writing. "Google Scholar", however, was not designed for linguistic searches…

Corpus Approaches to Language Ideology

ERIC Educational Resources Information Center

Vessey, Rachelle

2017-01-01

This paper outlines how corpus linguistics--and more specifically the corpus-assisted discourse studies approach--can add useful dimensions to studies of language ideology. First, it is argued that the identification of words of high, low, and statistically significant frequency can help in the identification and exploration of language ideologies…