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Sample records for adjacent brain parenchyma

  1. The use of diffusion weighted imaging to evaluate pathology outside the brain parenchyma in neuroimaging studies.

    PubMed

    Benjamin, Philip; Khan, Faraan; MacKinnon, Andrew D

    2017-04-01

    Diffusion-weighted imaging (DWI) has transformed the radiological assessment of a variety of cerebral pathologies, in particular acute stroke. In neuroimaging studies, DWI can also be used to evaluate pathology outside the brain parenchyma, although it is sometimes underutilized for this purpose. In this pictorial review, the principles of DWI are outlined, and 13 cases of abnormal diffusion outside the brain parenchyma are illustrated in order to show DWI as a useful sequence for the evaluation of the following recommended review areas: the dural venous sinuses, internal carotid arteries, meninges, ventricles, cavernous sinus and orbits, skull base and lymph nodes.

  2. The brain parenchyma has a type I interferon response that can limit virus spread

    PubMed Central

    Drokhlyansky, Eugene; Göz Aytürk, Didem; Soh, Timothy K.; Chrenek, Ryan; O’Loughlin, Elaine; Madore, Charlotte; Butovsky, Oleg; Cepko, Constance L.

    2017-01-01

    The brain has a tightly regulated environment that protects neurons and limits inflammation, designated “immune privilege.” However, there is not an absolute lack of an immune response. We tested the ability of the brain to initiate an innate immune response to a virus, which was directly injected into the brain parenchyma, and to determine whether this response could limit viral spread. We injected vesicular stomatitis virus (VSV), a transsynaptic tracer, or naturally occurring VSV-derived defective interfering particles (DIPs), into the caudate–putamen (CP) and scored for an innate immune response and inhibition of virus spread. We found that the brain parenchyma has a functional type I interferon (IFN) response that can limit VSV spread at both the inoculation site and among synaptically connected neurons. Furthermore, we characterized the response of microglia to VSV infection and found that infected microglia produced type I IFN and uninfected microglia induced an innate immune response following virus injection. PMID:27980033

  3. Correlation of neurocognitive function and brain parenchyma volumes in children surviving cancer

    NASA Astrophysics Data System (ADS)

    Reddick, Wilburn E.; White, Holly A.; Glass, John O.; Mulhern, Raymond K.

    2002-04-01

    This research builds on our hypothesis that white matter damage and associated neurocognitive symptoms, in children treated for cancer with cranial spinal irradiation, spans a continuum of severity that can be reliably probed using non-invasive MR technology. Quantitative volumetric assessments of MR imaging and psychological assessments were obtained in 40 long-term survivors of malignant brain tumors treated with cranial irradiation. Neurocognitive assessments included a test of intellect (Wechsler Intelligence Test for Children, Wechsler Adult Intelligence Scale), attention (Conner's Continuous Performance Test), and memory (California Verbal Learning Test). One-sample t-tests were conducted to evaluate test performance of survivors against age-adjusted scores from the test norms; these analyses revealed significant impairments in all apriori selected measures of intelligence, attention, and memory. Partial correlation analyses were performed to assess the relationships between brain tissues volumes (normal appearing white matter (NAWM), gray matter, and CSF) and neurocognitive function. Global intelligence (r = 0.32, p = 0.05) and global attentional (r = 0.49, p < 0.01) were significantly positively correlated with NAWM volumes, whereas global memory was significantly positively correlated with overall brain parenchyma (r = 0.38, p = 0.04). We conclude that quantitative assessment of MR examinations in survivors of childhood cancer treated with cranial irradiation reveal that loss of NAWM is associated with decreased intellectual and attentional deficits, whereas overall parenchyma loss, as reflected by increased CSF and decreased white matter, is associated with memory-related deficits.

  4. Agrin in Alzheimer's Disease: Altered Solubility and Abnormal Distribution within Microvasculature and Brain Parenchyma

    NASA Astrophysics Data System (ADS)

    Donahue, John E.; Berzin, Tyler M.; Rafii, Michael S.; Glass, David J.; Yancopoulos, George D.; Fallon, Justin R.; Stopa, Edward G.

    1999-05-01

    Agrin is a heparan sulfate proteoglycan that is widely expressed in neurons and microvascular basal lamina in the rodent and avian central nervous system. Agrin induces the differentiation of nerve-muscle synapses, but its function in either normal or diseased brains is not known. Alzheimer's disease (AD) is characterized by loss of synapses, changes in microvascular architecture, and formation of neurofibrillary tangles and senile plaques. Here we have asked whether AD causes changes in the distribution and biochemical properties of agrin. Immunostaining of normal, aged human central nervous system revealed that agrin is expressed in neurons in multiple brain areas. Robust agrin immunoreactivity was observed uniformly in the microvascular basal lamina. In AD brains, agrin is highly concentrated in both diffuse and neuritic plaques as well as neurofibrillary tangles; neuronal expression of agrin also was observed. Furthermore, patients with AD had microvascular alterations characterized by thinning and fragmentation of the basal lamina. Detergent extraction and Western blotting showed that virtually all the agrin in normal brain is soluble in 1% SDS. In contrast, a large fraction of the agrin in AD brains is insoluble under these conditions, suggesting that it is tightly associated with β -amyloid. Together, these data indicate that the agrin abnormalities observed in AD are closely linked to β -amyloid deposition. These observations suggest that altered agrin expression in the microvasculature and the brain parenchyma contribute to the pathogenesis of AD.

  5. Predictive models for pressure-driven fluid infusions into brain parenchyma

    NASA Astrophysics Data System (ADS)

    Raghavan, Raghu; Brady, Martin

    2011-10-01

    Direct infusions into brain parenchyma of biological therapeutics for serious brain diseases have been, and are being, considered. However, individual brains, as well as distinct cytoarchitectural regions within brains, vary in their response to fluid flow and pressure. Further, the tissue responds dynamically to these stimuli, requiring a nonlinear treatment of equations that would describe fluid flow and drug transport in brain. We here report in detail on an individual-specific model and a comparison of its prediction with simulations for living porcine brains. Two critical features we introduced into our model—absent from previous ones, but requirements for any useful simulation—are the infusion-induced interstitial expansion and the backflow. These are significant determinants of the flow. Another feature of our treatment is the use of cross-property relations to obtain individual-specific parameters that are coefficients in the equations. The quantitative results are at least encouraging, showing a high fraction of overlap between the computed and measured volumes of distribution of a tracer molecule and are potentially clinically useful. Several improvements are called for; principally a treatment of the interstitial expansion more fundamentally based on poroelasticity and a better delineation of the diffusion tensor of a particle confined to the interstitial spaces.

  6. Predictive models for pressure-driven fluid infusions into brain parenchyma

    PubMed Central

    Raghavan, Raghu; Brady, Martin

    2011-01-01

    Direct infusions into brain parenchyma of biological therapeutics for serious brain diseases have been, and are being, considered. However, individual brains, as well as distinct cytoarchitectural regions within brains, vary in their response to fluid flow and pressure. Further, the tissue responds dynamically to these stimuli, requiring a nonlinear treatment of equations that would describe fluid flow and drug transport in brain. We here report in detail on an individual–specific model and a comparison of its prediction with simulations for living porcine brains. Two critical features we introduced into our model — absent from previous ones, but requirements for any useful simulation — are the infusion-induced interstitial expansion and the backflow. These are significant determinants of the flow. Another feature of our treatment is the use of cross–property relations to obtain individual–specific parameters that are coefficients in the equations. The quantitative results are at least encouraging, showing a high fraction of overlap between the computed and measured volumes of distribution of a tracer molecule, and are potentially clinically useful. Several improvements are called for; principally a treatment of the interstitial expansion more fundamentally based on poroelasticity, and a better delineation of the diffusion tensor of a particle confined to the interstitial spaces. PMID:21891847

  7. Transcranial sonography (TCS) of brain parenchyma in movement disorders: quality standards, diagnostic applications and novel technologies.

    PubMed

    Walter, U; Školoudík, D

    2014-08-01

    Transcranial B-mode sonography (TCS) of brain parenchyma is being increasingly used as a diagnostic tool in movement disorders. Compared to other neuroimaging modalities such as magnetic resonance imaging (MRI) and computed tomography, TCS can be performed today with portable machines and has the advantages of noninvasiveness and high resistance to movement artifacts. In distinct brain disorders TCS detects abnormalities that cannot be visualized or can only be visualized with significant effort with other imaging methods. In the field of movement disorders, TCS has been established mainly as a tool for the early and differential diagnosis of Parkinson's disease. The postoperative position control of deep brain stimulation electrodes, especially in the subthalamic nucleus, can reliably and safely be performed with TCS.  The present update review summarizes the current methodological standards and defines quality criteria of adequate TCS imaging and assessment of diagnostically relevant deep brain structures such as substantia nigra, brainstem raphe, basal ganglia and ventricles. Finally, an overview is given on recent technological advances including TCS-MRI fusion imaging and upcoming technologies of digitized image analysis aiming at a more investigator-independent assessment of deep brain structures on TCS.

  8. Molecular crosstalk between tumour and brain parenchyma instructs histopathological features in glioblastoma

    PubMed Central

    Bougnaud, Sébastien; Golebiewska, Anna; Oudin, Anaïs; Keunen, Olivier; Harter, Patrick N.; Mäder, Lisa; Azuaje, Francisco; Fritah, Sabrina; Stieber, Daniel; Kaoma, Tony; Vallar, Laurent; Brons, Nicolaas H.C.; Daubon, Thomas; Miletic, Hrvoje; Sundstrøm, Terje; Herold-Mende, Christel; Mittelbronn, Michel; Bjerkvig, Rolf; Niclou, Simone P.

    2016-01-01

    The histopathological and molecular heterogeneity of glioblastomas represents a major obstacle for effective therapies. Glioblastomas do not develop autonomously, but evolve in a unique environment that adapts to the growing tumour mass and contributes to the malignancy of these neoplasms. Here, we show that patient-derived glioblastoma xenografts generated in the mouse brain from organotypic spheroids reproducibly give rise to three different histological phenotypes: (i) a highly invasive phenotype with an apparent normal brain vasculature, (ii) a highly angiogenic phenotype displaying microvascular proliferation and necrosis and (iii) an intermediate phenotype combining features of invasion and vessel abnormalities. These phenotypic differences were visible during early phases of tumour development suggesting an early instructive role of tumour cells on the brain parenchyma. Conversely, we found that tumour-instructed stromal cells differentially influenced tumour cell proliferation and migration in vitro, indicating a reciprocal crosstalk between neoplastic and non-neoplastic cells. We did not detect any transdifferentiation of tumour cells into endothelial cells. Cell type-specific transcriptomic analysis of tumour and endothelial cells revealed a strong phenotype-specific molecular conversion between the two cell types, suggesting co-evolution of tumour and endothelial cells. Integrative bioinformatic analysis confirmed the reciprocal crosstalk between tumour and microenvironment and suggested a key role for TGFβ1 and extracellular matrix proteins as major interaction modules that shape glioblastoma progression. These data provide novel insight into tumour-host interactions and identify novel stroma-specific targets that may play a role in combinatorial treatment strategies against glioblastoma. PMID:27049916

  9. Human Polyomavirus Receptor Distribution in Brain Parenchyma Contrasts with Receptor Distribution in Kidney and Choroid Plexus

    PubMed Central

    Haley, Sheila A.; O'Hara, Bethany A.; Nelson, Christian D.S.; Brittingham, Frances L.P.; Henriksen, Kammi J.; Stopa, Edward G.; Atwood, Walter J.

    2016-01-01

    The human polyomavirus, JCPyV, is the causative agent of progressive multifocal leukoencephalopathy, a rare demyelinating disease that occurs in the setting of prolonged immunosuppression. After initial asymptomatic infection, the virus establishes lifelong persistence in the kidney and possibly other extraneural sites. In rare instances, the virus traffics to the central nervous system, where oligodendrocytes, astrocytes, and glial precursors are susceptible to lytic infection, resulting in progressive multifocal leukoencephalopathy. The mechanisms by which the virus traffics to the central nervous system from peripheral sites remain unknown. Lactoseries tetrasaccharide c (LSTc), a pentasaccharide containing a terminal α2,6–linked sialic acid, is the major attachment receptor for polyomavirus. In addition to LSTc, type 2 serotonin receptors are required for facilitating virus entry into susceptible cells. We studied the distribution of virus receptors in kidney and brain using lectins, antibodies, and labeled virus. The distribution of LSTc, serotonin receptors, and virus binding sites overlapped in kidney and in the choroid plexus. In brain parenchyma, serotonin receptors were expressed on oligodendrocytes and astrocytes, but these cells were negative for LSTc and did not bind virus. LSTc was instead found on microglia and vascular endothelium, to which virus bound abundantly. Receptor distribution was not changed in the brains of patients with progressive multifocal leukoencephalopathy. Virus infection of oligodendrocytes and astrocytes during disease progression is LSTc independent. PMID:26056932

  10. Human polyomavirus receptor distribution in brain parenchyma contrasts with receptor distribution in kidney and choroid plexus.

    PubMed

    Haley, Sheila A; O'Hara, Bethany A; Nelson, Christian D S; Brittingham, Frances L P; Henriksen, Kammi J; Stopa, Edward G; Atwood, Walter J

    2015-08-01

    The human polyomavirus, JCPyV, is the causative agent of progressive multifocal leukoencephalopathy, a rare demyelinating disease that occurs in the setting of prolonged immunosuppression. After initial asymptomatic infection, the virus establishes lifelong persistence in the kidney and possibly other extraneural sites. In rare instances, the virus traffics to the central nervous system, where oligodendrocytes, astrocytes, and glial precursors are susceptible to lytic infection, resulting in progressive multifocal leukoencephalopathy. The mechanisms by which the virus traffics to the central nervous system from peripheral sites remain unknown. Lactoseries tetrasaccharide c (LSTc), a pentasaccharide containing a terminal α2,6-linked sialic acid, is the major attachment receptor for polyomavirus. In addition to LSTc, type 2 serotonin receptors are required for facilitating virus entry into susceptible cells. We studied the distribution of virus receptors in kidney and brain using lectins, antibodies, and labeled virus. The distribution of LSTc, serotonin receptors, and virus binding sites overlapped in kidney and in the choroid plexus. In brain parenchyma, serotonin receptors were expressed on oligodendrocytes and astrocytes, but these cells were negative for LSTc and did not bind virus. LSTc was instead found on microglia and vascular endothelium, to which virus bound abundantly. Receptor distribution was not changed in the brains of patients with progressive multifocal leukoencephalopathy. Virus infection of oligodendrocytes and astrocytes during disease progression is LSTc independent.

  11. [A Case of Transorbital Penetrating Brain Injury Caused by a Steel Wire Entirely Embedded in the Brain Parenchyma].

    PubMed

    Kin, Kyohei; Ono, Yasuhiro; Fujimori, Takeshi; Kuramoto, Satoshi; Katsumata, Atsushi; Goda, Yuji; Kawauchi, Masamitsu

    2015-10-01

    Penetrating brain injury(PBI)is very rare in Japan. Because there is a very wide variety of pathological condition of PBI, the guideline for the treatment of PBI has not been established yet. We report the unique case of PBI caused by a steel wire piece completely embedded in the brain parenchyma. A 75-year-old man was brought to the emergency department due to ocular injury caused by a steel wire piece. Neurological examination revealed only left visual disturbance. CT scan revealed a steel wire piece located intraparenchymally between the left frontal lobe and the ventricles, but digital subtraction angiography showed no significant vascular injury in the surrounding structures. We performed an open surgery and removed the steel wire piece. Because the steel wire piece was completely embedded in the brain, we used intraoperative X-ray fluoroscopy to choose a less invasive approach for the brain. The patient suffered no additional neurological deficit and no sign of cerebral infection or seizure after surgery. He was discharged after a 4-week administration of antibiotics. In most cases of PBI caused by low velocity injury, foreign bodies are not completely embedded in the brain except for remnants after surgical removal. This is the first report of low velocity PBI caused by a foreign body completely embedded in the brain.

  12. Access to the brain parenchyma using endovascular techniques and a micro-working channel.

    PubMed

    Lundberg, Johan; Johansson, Carina B; Jonsson, Stefan; Holmin, Staffan

    2017-02-01

    OBJECTIVE Several older studies report a low risk for parenchymal access to the CNS by surgical techniques. In more recent studies, including those with post-puncture CT scans, there are indications that the risk of bleeding might approach 8%. New therapies, such as those that use viral vectors, modified mRNA, or cell transplantation, will probably warrant more parenchymal access to the CNS. Other minimally invasive routes might then be tempting to explore. This study was designed in 2 parts to address the possibility of using the endovascular route. The first aim was to test the ability to create a parenchymal micro-working channel to the CNS in macaque monkeys through the vessel wall. Second, the biocompatibility of a device-associated, detached, distal securing plug that was made of nitinol was investigated in swine for 1 year. METHODS Trans-vessel wall intervention in the middle cerebral artery and associated cerebral parenchyma was performed in 4 rhesus macaque monkeys using a full clinical angiography suite. A contrast agent and methylene blue were injected to test the working channel and then detached at the distal end to act as a securing plug through the vessel wall. One-year follow-ups were also performed using angiography and histological analysis in 10 swine with 24 implants that were distributed in the external carotid artery tree. RESULTS The cerebral interventions were performed without acute bleeding. Both the contrast agent and methylene blue were infused into the brain parenchyma and subarachnoidal space via the endovascular micro-working channel (7 injections in 4 animals). In the 1-year follow-up period, the implant that was left in the external carotid vessel wall in the swine was covered by the endothelium, which was followed by dislodgement just outside the blood vessel with thin capsule formation. No stenosis in the artery was detected on 1-year angiography. The animals showed normal behavior and blood sample results during the follow

  13. Expression of klotho mRNA and protein in rat brain parenchyma from early postnatal development into adulthood.

    PubMed

    Clinton, Sarah M; Glover, Matthew E; Maltare, Astha; Laszczyk, Ann M; Mehi, Stephen J; Simmons, Rebecca K; King, Gwendalyn D

    2013-08-21

    Without the age-regulating protein klotho, mouse lifespan is shortened and the rapid onset of age-related disorders occurs. Conversely, overexpression of klotho extends mouse lifespan. Klotho is most abundant in kidney and expressed in a limited number of other organs, including the brain, where klotho levels are highest in choroid plexus. Reports vary on where klotho is expressed within the brain parenchyma, and no data is available as to whether klotho levels change across postnatal development. We used in situ hybridization to map klotho mRNA expression in the developing and adult rat brain and report moderate, widespread expression across grey matter regions. mRNA expression levels in cortex, hippocampus, caudate putamen, and amygdala decreased during the second week of life and then gradually rose to adult levels by postnatal day 21. Immunohistochemistry revealed a protein expression pattern similar to the mRNA results, with klotho protein expressed widely throughout the brain. Klotho protein co-localized with both the neuronal marker NeuN, as well as, oligodendrocyte marker olig2. These results provide the first anatomical localization of klotho mRNA and protein in rat brain parenchyma and demonstrate that klotho levels vary during early postnatal development.

  14. A Paravascular Pathway Facilitates CSF Flow Through the Brain Parenchyma and the Clearance of Interstitial Solutes, Including Amyloid β

    PubMed Central

    Iliff, Jeffrey J.; Wang, Minghuan; Liao, Yonghong; Plogg, Benjamin A.; Peng, Weiguo; Gundersen, Georg A.; Benveniste, Helene; Vates, G. Edward; Deane, Rashid; Goldman, Steven A.; Nagelhus, Erlend A.; Nedergaard, Maiken

    2013-01-01

    Because it lacks a lymphatic circulation, the brain must clear extracellular proteins by an alternative mechanism. The cerebrospinal fluid (CSF) functions as a sink for brain extracellular solutes, but it is not clear how solutes from the brain interstitium move from the parenchyma to the CSF. We demonstrate that a substantial portion of subarachnoid CSF cycles through the brain interstitial space. On the basis of in vivo two-photon imaging of small fluorescent tracers, we showed that CSF enters the parenchyma along paravascular spaces that surround penetrating arteries and that brain interstitial fluid is cleared along paravenous drainage pathways. Animals lacking the water channel aquaporin-4 (AQP4) in astrocytes exhibit slowed CSF influx through this system and a ~70% reduction in interstitial solute clearance, suggesting that the bulk fluid flow between these anatomical influx and efflux routes is supported by astrocytic water transport. Fluorescent-tagged amyloid β, a peptide thought to be pathogenic in Alzheimer’s disease, was transported along this route, and deletion of the Aqp4 gene suppressed the clearance of soluble amyloid β, suggesting that this pathway may remove amyloid β from the central nervous system. Clearance through paravenous flow may also regulate extracellular levels of proteins involved with neurodegenerative conditions, its impairment perhaps contributing to the mis-accumulation of soluble proteins. PMID:22896675

  15. Sleep and rhythm changes at the time of Trypanosoma brucei invasion of the brain parenchyma in the rat.

    PubMed

    Seke Etet, Paul F; Palomba, Maria; Colavito, Valeria; Grassi-Zucconi, Gigliola; Bentivoglio, Marina; Bertini, Giuseppe

    2012-05-01

    Human African trypanosomiasis (HAT), or sleeping sickness, is a severe disease caused by Trypanosoma brucei (T.b.). The disease hallmark is sleep alterations. Brain involvement in HAT is a crucial pathogenetic step for disease diagnosis and therapy. In this study, a rat model of African trypanosomiasis was used to assess changes of sleep-wake, rest-activity, and body temperature rhythms in the time window previously shown as crucial for brain parenchyma invasion by T.b. to determine potential biomarkers of this event. Chronic radiotelemetric monitoring in Sprague-Dawley rats was used to continuously record electroencephalogram, electromyogram, rest-activity, and body temperature in the same animals before (baseline recording) and after infection. Rats were infected with T.b. brucei. Data were acquired from 1 to 20 d after infection (parasite neuroinvasion initiates at 11-13 d post-infection in this model), and were compared to baseline values. Sleep parameters were manually scored from electroencephalographic-electromyographic tracings. Circadian rhythms of sleep time, slow-wave activity, rest-activity, and body temperature were studied using cosinor rhythmometry. Results revealed alterations of most of the analyzed parameters. In particular, sleep pattern and sleep-wake organization plus rest-activity and body temperature rhythms exhibited early quantitative and qualitative alterations, which became marked around the time interval crucial for parasite neuroinvasion or shortly after. Data derived from actigrams showed close correspondence with those from hypnograms, suggesting that rest-activity could be useful to monitor sleep-wake alterations in African trypanosomiasis.

  16. Trypanosoma brucei Invasion and T-Cell Infiltration of the Brain Parenchyma in Experimental Sleeping Sickness: Timing and Correlation with Functional Changes

    PubMed Central

    Laperchia, Claudia; Palomba, Maria; Seke Etet, Paul F.; Rodgers, Jean; Bradley, Barbara; Montague, Paul; Grassi-Zucconi, Gigliola; Bentivoglio, Marina

    2016-01-01

    Background The timing of Trypanosoma brucei entry into the brain parenchyma to initiate the second, meningoencephalitic stage of human African trypanosomiasis or sleeping sickness is currently debated and even parasite invasion of the neuropil has been recently questioned. Furthermore, the relationship between neurological features and disease stage are unclear, despite the important diagnostic and therapeutic implications. Methodology Using a rat model of chronic Trypanosoma brucei brucei infection we determined the timing of parasite and T-cell neuropil infiltration and its correlation with functional changes. Parasite DNA was detected using trypanosome-specific PCR. Body weight and sleep structure alterations represented by sleep-onset rapid eye movement (SOREM) periods, reported in human and experimental African trypanosomiasis, were monitored. The presence of parasites, as well as CD4+ and CD8+ T-cells in the neuropil was assessed over time in the brain of the same animals by immunocytochemistry and quantitative analyses. Principal findings Trypanosome DNA was present in the brain at day 6 post-infection and increased more than 15-fold by day 21. Parasites and T-cells were observed in the parenchyma from day 9 onwards. Parasites traversing blood vessel walls were observed in the hypothalamus and other brain regions. Body weight gain was reduced from day 7 onwards. SOREM episodes started in most cases early after infection, with an increase in number and duration after parasite neuroinvasion. Conclusion These findings demonstrate invasion of the neuropil over time, after an initial interval, by parasites and lymphocytes crossing the blood-brain barrier, and show that neurological features can precede this event. The data thus challenge the current clinical and cerebrospinal fluid criteria of disease staging. PMID:28002454

  17. Non-target adjacent stimuli classification improves performance of classical ERP-based brain computer interface

    NASA Astrophysics Data System (ADS)

    Ceballos, G. A.; Hernández, L. F.

    2015-04-01

    Objective. The classical ERP-based speller, or P300 Speller, is one of the most commonly used paradigms in the field of Brain Computer Interfaces (BCI). Several alterations to the visual stimuli presentation system have been developed to avoid unfavorable effects elicited by adjacent stimuli. However, there has been little, if any, regard to useful information contained in responses to adjacent stimuli about spatial location of target symbols. This paper aims to demonstrate that combining the classification of non-target adjacent stimuli with standard classification (target versus non-target) significantly improves classical ERP-based speller efficiency. Approach. Four SWLDA classifiers were trained and combined with the standard classifier: the lower row, upper row, right column and left column classifiers. This new feature extraction procedure and the classification method were carried out on three open databases: the UAM P300 database (Universidad Autonoma Metropolitana, Mexico), BCI competition II (dataset IIb) and BCI competition III (dataset II). Main results. The inclusion of the classification of non-target adjacent stimuli improves target classification in the classical row/column paradigm. A gain in mean single trial classification of 9.6% and an overall improvement of 25% in simulated spelling speed was achieved. Significance. We have provided further evidence that the ERPs produced by adjacent stimuli present discriminable features, which could provide additional information about the spatial location of intended symbols. This work promotes the searching of information on the peripheral stimulation responses to improve the performance of emerging visual ERP-based spellers.

  18. Evolutionary origins of non-adjacent sequence processing in primate brain potentials

    PubMed Central

    Milne, Alice E.; Mueller, Jutta L.; Männel, Claudia; Attaheri, Adam; Friederici, Angela D.; Petkov, Christopher I.

    2016-01-01

    There is considerable interest in understanding the ontogeny and phylogeny of the human language system, yet, neurobiological work at the interface of both fields is absent. Syntactic processes in language build on sensory processing and sequencing capabilities on the side of the receiver. While we better understand language-related ontogenetic changes in the human brain, it remains a mystery how neurobiological processes at specific human development stages compare with those in phylogenetically closely related species. To address this knowledge gap, we measured EEG event-related potentials (ERPs) in two macaque monkeys using a paradigm developed to evaluate human infant and adult brain potentials associated with the processing of non-adjacent ordering relationships in sequences of syllable triplets. Frequent standard triplet sequences were interspersed with infrequent voice pitch or non-adjacent rule deviants. Monkey ERPs show early pitch and rule deviant mismatch responses that are strikingly similar to those previously reported in human infants. This stands in contrast to adults’ later ERP responses for rule deviants. The results reveal how non-adjacent sequence ordering relationships are processed in the primate brain and provide evidence for evolutionarily conserved neurophysiological effects, some of which are remarkably like those seen at an early human developmental stage. PMID:27827366

  19. Control of a brain-computer interface using stereotactic depth electrodes in and adjacent to the hippocampus

    NASA Astrophysics Data System (ADS)

    Krusienski, D. J.; Shih, J. J.

    2011-04-01

    A brain-computer interface (BCI) is a device that enables severely disabled people to communicate and interact with their environments using their brain waves. Most research investigating BCI in humans has used scalp-recorded electroencephalography or intracranial electrocorticography. The use of brain signals obtained directly from stereotactic depth electrodes to control a BCI has not previously been explored. In this study, event-related potentials (ERPs) recorded from bilateral stereotactic depth electrodes implanted in and adjacent to the hippocampus were used to control a P300 Speller paradigm. The ERPs were preprocessed and used to train a linear classifier to subsequently predict the intended target letters. The classifier was able to predict the intended target character at or near 100% accuracy using fewer than 15 stimulation sequences in the two subjects tested. Our results demonstrate that ERPs from hippocampal and hippocampal adjacent depth electrodes can be used to reliably control the P300 Speller BCI paradigm.

  20. Peripheral osmotic stimulation inhibits the brain's innate immune response to microdialysis of acidic perfusion fluid adjacent to supraoptic nucleus

    PubMed Central

    Hu, Sanmei

    2009-01-01

    During the brain's innate immune response microglia, astroglia and ependymal cells resolve/repair damaged tissue and control infection. Released interleukin-1β (IL-1β) reaching cerebroventricles stimulates circumventricular organs (CVOs; subfornical organ, SFO; organum vasculosum lamina terminalis, OVLT), the median preoptic nucleus (MePO), and magnocellular and parvocellular neurons in the supraoptic (SON) and paraventricular (PVN) nuclei. Hypertonic saline (HS) also activates these osmosensory CVOs and neuroendocrine systems, but, in contrast to IL-1β, inhibits the peripheral immune response. To examine whether the brain's innate immune response is attenuated by osmotic stimulation, sterile acidic perfusion fluid was microdialyzed (2 μl/min) in the SON area of conscious rats for 6 h with sterile HS (1.5 M NaCl) injected subcutaneously (15 ml/kg) at 5 h. Immunohistochemistry identified cytokine sources (IL-1β+; OX-42+ microglia) and targets (IL-1R+; inducible cyclooxygenase, COX-2+; c-Fos+) near the probe, in CVOs, MePO, ependymal cells, periventricular hypothalamus, SON, and PVN. Inserting the probe stimulated magnocellular neurons (c-Fos+; SON; PVN) via the MePO (c-Fos+), a response enhanced by HS. Microdialysis activated microglia (OX-42+; amoeboid/hypertrophied; IL-1β+) in the adjacent SON and bilaterally in perivascular areas of the PVN, periventricular hypothalamus and ependyma, coincident with c-Fos expression in ependymal cells and COX-2 in the vasculature. These microglial responses were attenuated by HS, coincident with activating parvocellular and magnocellular neuroendocrine systems and elevating circulating IL-1β, oxytocin, and vasopressin. Acidosis-induced cellular injury from microdialysis activated the brain's innate immune response by a mechanism inhibited by peripheral osmotic stimulation. PMID:19759333

  1. Progenitor/Stem Cell Markers in Brain Adjacent to Glioblastoma: GD3 Ganglioside and NG2 Proteoglycan Expression.

    PubMed

    Lama, Gina; Mangiola, Annunziato; Proietti, Gabriella; Colabianchi, Anna; Angelucci, Cristiana; D' Alessio, Alessio; De Bonis, Pasquale; Geloso, Maria Concetta; Lauriola, Libero; Binda, Elena; Biamonte, Filippo; Giuffrida, Maria Grazia; Vescovi, Angelo; Sica, Gigliola

    2016-02-01

    Characterization of tissue surrounding glioblastoma (GBM) is a focus for translational research because tumor recurrence invariably occurs in this area. We investigated the expression of the progenitor/stem cell markers GD3 ganglioside and NG2 proteoglycan in GBM, peritumor tissue (brain adjacent to tumor, BAT) and cancer stem-like cells (CSCs) isolated from GBM (GCSCs) and BAT (PCSCs). GD3 and NG2 immunohistochemistry was performed in paired GBM and BAT specimens from 40 patients. Double-immunofluorescence was carried out to characterize NG2-positive cells of vessel walls. GD3 and NG2 expression was investigated in GCSCs and PCSCs whose tumorigenicity was also evaluated in Scid/bg mice. GD3 and NG2 expression was higher in tumor tissue than in BAT. NG2 decreased as the distance from tumor margin increased, regardless of the tumor cell presence, whereas GD3 correlated with neoplastic infiltration. In BAT, NG2 was coexpressed with a-smooth muscle actin (a-SMA) in pericytes and with nestin in the endothelium. Higher levels of NG2 mRNA and protein were found in GCSCs while GD3 synthase was expressed at similar levels in the 2 CSC populations. PCSCs had lower tumorigenicity than GCSCs. These data suggest the possible involvement of GD3 and NG2 in pre/pro-tumorigenic events occurring in the complex microenvironment of the tissue surrounding GBM.

  2. A mathematical model of lung parenchyma.

    PubMed

    Karakaplan, A D; Bieniek, M P; Skalak, R

    1980-05-01

    The geometry of the proposed model of the parenchyma of a mammalian lung reproduces a cluster of alveoli arranged around a lowest-level air duct. The alveolar walls are assumed to be nonlinear elastic membranes, whose properties are described in terms of a strain energy function which reflects the hardening character of the stress-strain curve. The effect of the surfactant is included in terms of a variable (area-dependent) surface tension. Analyses of various mechanical processes in the parenchyma are performed with the aid of the finite element method, with the geometric and physical nonlinearities of the problem taken into account.

  3. Effectiveness of hepatic parenchyma lithotomy of hepatolithiasis

    PubMed Central

    Li, En Liang; Feng, Qian; Yang, Qing Ping; Liao, Wen Jun; Liu, Wang Wei; Huang, Yong; Wu, Lin Quan; Yin, Xiang Bao; Shao, Jiang Hua

    2017-01-01

    Abstract To investigate the clinical significance of hepatic parenchyma incision by lithotomy near the second hepatic portal area for the treatment of complex hepatolithiasis. A retrospective study was conducted with 35 patients who had complicated hepatolithiasis in our hospital from January 2008 to December 2013, who underwent hepatic parenchyma incision by lithotomy near the second hepatic portal area. The perioperative and long-term outcomes included the stone clearance rate, operative morbidity and mortality, and the stone recurrence rate. Patients with a preoperative diagnosis of cholangiocarcinoma were excluded from the study. All patients with hepatic duct stones were mainly located at S2, S4, and S8 regions. Surgical methods included were hepatic parenchyma incision by lithotomy near the second hepatic portal area, or by combined partial hepatectomy. The mean follow-up period was 51 months. One patient died during hospitalization. The surgical morbidity was 17.6%, stone clearance rate was 88.2%, and final clearance rate was 94.1% followed by postoperative choledochoscopic lithotripsy. The stone recurrence rate was 15.6% and the occurrence of postoperative cholangitis was 11.8% during the follow-up period. Hepatic parenchyma incision by lithotomy near the second hepatic portal area is safe with satisfactory short and long-term outcome results for complicated hepatolithiasis. PMID:28272201

  4. Dissimilarity representations in lung parenchyma classification

    NASA Astrophysics Data System (ADS)

    Sørensen, Lauge; de Bruijne, Marleen

    2009-02-01

    A good problem representation is important for a pattern recognition system to be successful. The traditional approach to statistical pattern recognition is feature representation. More specifically, objects are represented by a number of features in a feature vector space, and classifiers are built in this representation. This is also the general trend in lung parenchyma classification in computed tomography (CT) images, where the features often are measures on feature histograms. Instead, we propose to build normal density based classifiers in dissimilarity representations for lung parenchyma classification. This allows for the classifiers to work on dissimilarities between objects, which might be a more natural way of representing lung parenchyma. In this context, dissimilarity is defined between CT regions of interest (ROI)s. ROIs are represented by their CT attenuation histogram and ROI dissimilarity is defined as a histogram dissimilarity measure between the attenuation histograms. In this setting, the full histograms are utilized according to the chosen histogram dissimilarity measure. We apply this idea to classification of different emphysema patterns as well as normal, healthy tissue. Two dissimilarity representation approaches as well as different histogram dissimilarity measures are considered. The approaches are evaluated on a set of 168 CT ROIs using normal density based classifiers all showing good performance. Compared to using histogram dissimilarity directly as distance in a emph{k} nearest neighbor classifier, which achieves a classification accuracy of 92.9%, the best dissimilarity representation based classifier is significantly better with a classification accuracy of 97.0% (text{emph{p" border="0" class="imgtopleft"> = 0.046).

  5. Airway-parenchyma uncoupling in nocturnal asthma.

    PubMed

    Irvin, C G; Pak, J; Martin, R J

    2000-01-01

    Airway flow resistance is well known to be dependent upon lung volume. The rise in lung volume that occurs in asthma is therefore thought to be an important mechanism that defends airway patency. The purpose of the current study was to investigate the interdependence or mechanical coupling between airways and lung parenchyma during the inflammatory processes that occur in the patient with nocturnal asthma. Five patients with documented nocturnal asthma were studied in both a vertical and a horizontal body plethysmograph. Lung volume was altered with continuous negative pressure as applied to the chest wall with a poncho cuirass in different postures and during sleep. We found during the awake phase that an increase in lung volume decreased lower pulmonary resistance (Rlp); however, within 30 min of sleep onset, functional residual capacity (FRC) fell and Rlp rose more than would be expected for the fall in FRC. Restoring FRC to presleep values either at an early (half-hour) or a late (3-h) time point did not cause Rlp to significantly fall. A second phase of the study showed that the loss of Rlp dependence on lung volume was not due to the assumption of the supine posture. Indirect measurements of lung compliance were consistent with a stiffening of the lung. We conclude that with sleep there is an immediate uncoupling of the parenchyma to the airway, resulting in a loss of interdependence that persists throughout sleep and may contribute to the morbidity and mortality associated with nocturnal asthma.

  6. Localization of phenolics in phloem parenchyma cells of Norway spruce (Picea abies).

    PubMed

    Li, Sheng-Hong; Nagy, Nina Elisabeth; Hammerbacher, Almuth; Krokene, Paal; Niu, Xue-Mei; Gershenzon, Jonathan; Schneider, Bernd

    2012-12-21

    Norway spruce (Picea abies) bark contains specialized phloem parenchyma cells that swell and change their contents upon attack by the bark beetle Ips typographus and its microbial associate, the blue stain fungus Ceratocystis polonica. These cells exhibit bright autofluorescence after treatment with standard aldehyde fixatives, and so have been postulated to contain phenolic compounds. Laser microdissection of spruce bark sections combined with cryogenic NMR spectroscopy demonstrated significantly higher concentrations of the stilbene glucoside astringin in phloem parenchyma cells than in adjacent sieve cells. After infection by C. polonica, the flavonoid (+)-catechin also appeared in phloem parenchyma cells and there was a decrease in astringin content compared to cells from uninfected trees. Analysis of whole-bark extracts confirmed the results obtained from the cell extracts and revealed a significant increase in dimeric stilbene glucosides, both astringin and isorhapontin derivatives (piceasides A to H), in fungus-infected versus uninfected bark that might explain the reduction in stilbene monomers. Phloem parenchyma cells thus appear to be a principal site of phenolic accumulation in spruce bark.

  7. Elasticity of excised dog lung parenchyma

    NASA Technical Reports Server (NTRS)

    Vawter, D. L.; Fung, Y. C.; West, J. B.

    1978-01-01

    An optical-electromechanical system is used to measure the force-deformation behavior of biaxially loaded rectangular slabs of excised dog lung parenchyma. In the course of the study, the effects of time, the consistency of reference lengths and areas, the presence of hysteresis, the necessity of preconditioning, the repeatability of results, the effects of lateral load, the effect of strain rate, the effect of pH, the influence of temperature, and the variations among specimens are considered. A new finding is that there is a change in elastic behavior when the tissue undergoes a compressive strain. When the tissue is in tension, increasing the lateral load decreases the compliance, whereas the opposite is true when compressive strain is present.

  8. Magnetization transfer and T2 quantitation in normal appearing cortical gray matter and white matter adjacent to focal abnormality in patients with traumatic brain injury.

    PubMed

    Kumar, Rajesh; Gupta, Rakesh K; Rao, Sajja B; Chawla, Sanjeev; Husain, Mazhar; Rathore, Ram K S

    2003-10-01

    Traumatic brain injury (TBI) is one of the commonest causes of morbidity and mortality in the developed countries with posttraumatic epilepsy and functional disability being its major sequelae. The purpose of this study was to test the hypothesis whether the normal appearing adjacent gray and white matter regions on T2 and T1 weighted magnetization transfer (MT) weighted images show any abnormality on quantitative imaging in patients with TBI. A total of 51 patients with TBI and 10 normal subjects were included in this study. There were significant differences in T2 and MT ratio values of T2 weighted and T1 weighted MT normal appearing gray matter regions adjacent to focal image abnormality compared to normal gray matter regions in the normal individuals as corresponding contralateral regions of the TBI patient's group (p < 0.05). However the adjoining normal appearing white matter quantitative values did not show any significant change compared to the corresponding contralateral normal white matter values. We conclude that quantitative T2 and MT ratio values provide additional abnormality in patients with TBI that is not discernable on conventional T2 weighted and T1 weighted MT imaging especially in gray matter. This additional information may be of value in overall management of these patients with TBI.

  9. Destruction of renal parenchyma at percutaneous nephrolithotripsy; experimental study.

    PubMed

    Tsujimoto, Y; Shima, H; Mori, Y; Ikoma, F

    1989-07-01

    The destruction of renal parenchyma caused by excess deflection of the sheath was examined to determine at what level of force the renal parenchyma was ruptured during PNL. The kidney obtained from right nephroureterectomy due to renal pelvic cancer (stage T2N0M0) of a 54-year-old female patient was punctured at the posterolateral portion with a puncture needle. The tract was dilated up to 26 Fr. in size with an Amplatz renal dilation set. The 26 Fr. sheath was left in the tract and fixed to the metal bar attached to Gig Boring Machine (Hydroptic-6) which could sense the change of pressure added to the renal parenchyma in the parallel movement of the metal bar. The critical angle in regard to the deflection of the renal parenchyma in order not to cause the rupture of renal parenchyma on PNL was calculated from both the resultant force and the shape of the wound of renal parenchyma at rupture. The safety angle against horizontal plane of the tract ranged from 18 to 37 degree.

  10. Improved pulmonary nodule classification utilizing lung parenchyma texture features

    NASA Astrophysics Data System (ADS)

    Dilger, S. K.; Judisch, A.; Uthoff, J.; Hammond, E.; Newell, J. D.; Sieren, J. C.

    2015-03-01

    Current computer-aided diagnosis (CAD) models, developed to determine the malignancy of pulmonary nodules, characterize the nodule's shape, density, and border. Analyzing the lung parenchyma surrounding the nodule is an area that has been minimally explored. We hypothesize that improved classification of nodules can be achieved through the inclusion of features quantified from the surrounding lung tissue. From computed tomography (CT) data, feature extraction techniques were developed to quantify the parenchymal and nodule textures, including a three-dimensional application of Laws' Texture Energy Measures. Border irregularity was investigated using ray-casting and rubber-band straightening techniques, while histogram features characterized the densities of the nodule and parenchyma. The feature set was reduced by stepwise feature selection to a few independent features that best summarized the dataset. Using leave-one-out cross-validation, a neural network was used for classification. The CAD tool was applied to 50 nodules (22 malignant, 28 benign) from high-resolution CT scans. 47 features, including 39 parenchymal features, were statistically significant, with both nodule and parenchyma features selected for classification, yielding an area under the ROC curve (AUC) of 0.935. This was compared to classification solely based on the nodule yielding an AUC of 0.917. These preliminary results show an increase in performance when the surrounding parenchyma is included in analysis. While modest, the improvement and large number of significant parenchyma features supports our hypothesis that the parenchyma contains meaningful data that can assist in CAD development.

  11. Frequent p53 mutation in brain (fetal)-type glycogen phosphorylase positive foci adjacent to human ‘de novo’olorectal carcinomas

    PubMed Central

    Shimada, S; Shiomori, K; Tashima, S; Tsuruta, J; Ogawa, M

    2001-01-01

    ‘de novo’ carcinogenesis has been advocated besides ‘adenoma carcinoma sequence’ as another dominant pathway leading to colorectal carcinoma. Our recent study has demonstrated that the distribution of brain (fetal)-type glycogen phosphorylase (BGP) positive foci (BGP foci) has a close relationship with the location of ‘de novo’ carcinoma. The aims of the present study are to investigate genetic alteration in the BGP foci and to characterize them in the ‘de novo’ carcinogenesis. 17 colorectal carcinomas without any adenoma component expressing both immunoreactive p53 and BGP protein were selected from 96 resected specimens from our previous study. Further investigations to examine the proliferating cell nuclear antigen (PCNA)-labelling index, and the p53 and the codon 12 of K-ras mutation using the polymerase chain reaction-single strand conformation polymorphism were performed in the BGP foci, BGP negative mucosa and carcinoma. The BGP foci were observed sporadically in the transitional mucosa adjacent to the carcinoma in all cases. The PCNA labelling index in the BGP foci was significantly higher than that in the BGP negative mucosa (P< 0.001). p53 mutations were observed in 8 carcinomas, but no K-ras mutation was detected. Interestingly, although none of the overexpressions of p53 protein was detected immunohistochemically in the BGP positive foci, the p53 gene frequently (41.2% of the BGP foci tested) mutated in spite of no K-ras mutation. The present study demonstrates potentially premalignant foci in the colorectal transitional mucosa with frequent p53 gene mutation. It is suggested that BGP foci are promising candidates for the further investigation of ‘de novo’ colorectal carcinogenesis. © 2001Cancer Research Campaign http://www.bjcancer.com PMID:11384100

  12. Tissue motion and strain in the human brain assessed by intraoperative ultrasound in glioma patients.

    PubMed

    Selbekk, Tormod; Brekken, Reidar; Solheim, Ole; Lydersen, Stian; Hernes, Toril A N; Unsgaard, Geirmund

    2010-01-01

    The objective of the study was to investigate tissue motion and strain imposed by cardiovascular pulsation in pathologic and normal brain parenchyma, as quantified from in vivo ultrasound data. Ultrasound acquired during surgery of 16 patients with glial tumors was retrospectively processed and analyzed. The tissue velocity was quantified at depths of 1cm, 2cm and 3cm from brain cortex to investigate spatial dependency with depth. Comparison of strain and velocity in tumor and adjacent normal parenchyma was performed by selecting two regions-of-interest in the hyperechoic tumor and two regions in the low-echogenic areas interpreted as mainly normal tissue with some degree of tumor cell infiltration. The absolute maximum tissue velocity is seen to increase with increasing depths in 14 of 16 cases (87.5%). The maximum tissue velocities in the four regions close to the ultrasound visible tumor border are not statistically different (p=0.163 to p=0.975). The strain magnitudes are significantly higher in the regions with expected normal brain parenchyma than in regions with expected glial tumor tissue, both for the two regions being closest to the tumor border (p=0.0004) and for the two regions further away from the tumor border (p=0.0009). We conclude that the velocity of the brain parenchyma imposed by arterial pulsation during a cardiac cycle is generally increasing with increasing depth from cortex. The maximum velocity appears to be similar in regions with expected normal brain and tumor tissue, thus, does not seem to be affected by pathology. Strain magnitude is, however, a suitable parameter for discrimination of glial tumor and normal brain parenchyma. (E-mail: Tormod.Selbekk@sintef.no).

  13. Rapid loss of renal parenchyma after acute obstruction.

    PubMed

    Parvex, P; Pippi-Salle, J L; Goodyer, P R

    2001-12-01

    Urinary tract obstruction (UTO) is a frequent cause of renal failure in the pediatric population. We report a patient with type I/I cystinuria, followed prospectively from birth with yearly ultrasonography, who developed acute UTO due to a cystine stone at 10 years of age. In animal models of UTO, acute obstruction produces rapid loss of renal parenchyma secondary to apoptosis of tubular cells. Since we had prospectively obtained serial ultrasonographic measurements of renal growth, we were able to document sudden decrease in kidney size and function following UTO, suggesting that programmed cell death may similarly have caused the rapid irreversible loss of renal parenchyma in our patient. Despite surgical relief of the obstruction, kidney size decreased for at least 3-4 months. We speculate that anti-apoptotic drugs might be considered as a therapeutic strategy to protect ongoing renal parenchyma loss in UTO.

  14. Improved pulmonary nodule classification utilizing quantitative lung parenchyma features.

    PubMed

    Dilger, Samantha K N; Uthoff, Johanna; Judisch, Alexandra; Hammond, Emily; Mott, Sarah L; Smith, Brian J; Newell, John D; Hoffman, Eric A; Sieren, Jessica C

    2015-10-01

    Current computer-aided diagnosis (CAD) models for determining pulmonary nodule malignancy characterize nodule shape, density, and border in computed tomography (CT) data. Analyzing the lung parenchyma surrounding the nodule has been minimally explored. We hypothesize that improved nodule classification is achievable by including features quantified from the surrounding lung tissue. To explore this hypothesis, we have developed expanded quantitative CT feature extraction techniques, including volumetric Laws texture energy measures for the parenchyma and nodule, border descriptors using ray-casting and rubber-band straightening, histogram features characterizing densities, and global lung measurements. Using stepwise forward selection and leave-one-case-out cross-validation, a neural network was used for classification. When applied to 50 nodules (22 malignant and 28 benign) from high-resolution CT scans, 52 features (8 nodule, 39 parenchymal, and 5 global) were statistically significant. Nodule-only features yielded an area under the ROC curve of 0.918 (including nodule size) and 0.872 (excluding nodule size). Performance was improved through inclusion of parenchymal (0.938) and global features (0.932). These results show a trend toward increased performance when the parenchyma is included, coupled with the large number of significant parenchymal features that support our hypothesis: the pulmonary parenchyma is influenced differentially by malignant versus benign nodules, assisting CAD-based nodule characterizations.

  15. A tree-parenchyma coupled model for lung ventilation simulation.

    PubMed

    Pozin, N; Montesantos, S; Katz, I; Pichelin, M; Vignon-Clementel, I; Grandmont, C

    2017-02-22

    In this article we develop a lung-ventilation model. The parenchyma is described as an elastic homogenized media. It is irrigated by a space-filling dyadic resistive pipe network, which represents the tracheo-bronchial tree. In this model the tree and the parenchyma are strongly coupled. The tree induces an extra viscous term in the system constitutive relation, which leads, in the finite element framework, to a full matrix. We consider an efficient algorithm that takes advantage of the tree structure to enable a fast matrix-vector product computation. This framework can be used to model both free and mechanically induced respiration, in health and disease. Patient-specific lung geometries acquired from CT scans are considered. Realistic Dirichlet boundary conditions can be deduced from surface registration on CT images. The model is compared to a more classical exit-compartment approach. Results illustrate the coupling between the tree and the parenchyma, at global and regional levels, and how conditions for the purely 0D model can be inferred. Different types of boundary conditions are tested, including a nonlinear Robin model of the surrounding lung structures.

  16. A new boundary correction method for lung parenchyma

    NASA Astrophysics Data System (ADS)

    Liang, Junfang; Jiang, Huiqin; Ma, Ling; Liu, Yumin; Toshiya, Nakaguchi

    2017-02-01

    In order to repair the boundary depressions caused by juxtapleural nodules and improve the lung segmentation accuracy, we propose a new boundary correction method for lung parenchyma. Firstly, the top-hat filter is used to enhance the image contrast; Secondly, we employ the Ostu algorithm for image binarization; Thirdly, the connected component labeling algorithm is utilized to remove the main trachea; Fourthly, the initial mask image is obtained by morphological region filling algorithm; Fifthly, the boundary tracing algorithm is applied to extract the initial lung contour; Afterwards, we design a sudden change degree algorithm to modify the initial lung contour; Finally, the complete lung parenchyma image is obtained. The novelty is that sudden change degree algorithm can detect the inflection points more accurately than other methods, which contributes to repairing lung contour efficiently. The experimental results show that the proposed method can incorporate the juxtapleural nodules into the lung parenchyma effectively, and the precision is increased by 6.46% and 2.72% respectively compared with the other two methods, providing favorable conditions for the accurate detection of pulmonary nodules and having important clinical value.

  17. Interstitial laser photocoagulation of normal lung parenchyma in rats

    PubMed Central

    Fielding, D; Buonaccorsi, G; Hanby, A; Hetzel, M; Bown, S

    1998-01-01

    BACKGROUND—Management of peripheral lung tumours may be risky in patients with poor lung function or in the elderly. A new possibility is interstitial laser photocoagulation (ILP) in which tumours are gently coagulated using thin laser fibres placed percutaneously under radiological guidance. This could have a useful palliative role in selected patients, but to be safe the effects on normal lung parenchyma must first be understood. This paper describes the creation and healing of ILP lesions in the normal rat lung.
METHODS—ILP was performed using single laser fibres placed percutaneously in the left lung of normal rats under general anaesthetic with radiological guidance (laser power 1-3 W at 805 nm, treatment time 250-1000 s). The lesion size and healing were studied in rats killed at times from three days to six months after treatment, the bursting pressure was measured, and any complications noted.
RESULTS—Zones of necrosis up to 12 mm in diameter were produced, the size depending on the laser power and treatment time. Histological examination showed typical thermal effects with complete healing with fibrosis by two months. The effect was very localised with remarkably little effect on the structure and function of the rest of the lung. Adverse effects in the lung parenchyma only occurred if the ILP lesion involved the hilar vessels or the oesophagus, causing pulmonary congestion and perforation, respectively. Pneumothorax was seen in 6% of cases.
CONCLUSIONS—ILP with a single fibre can produce a localised zone of necrosis in normal lung parenchyma which heals safely and which has little effect on the rest of the lung. Further study of this technique using multiple fibres in a larger animal model is warranted to see if it is feasible and safe to produce a large enough volume of necrosis to be of value in the treatment of small peripheral lung tumours in patients who are unsuitable for surgery or palliative radiotherapy.

 PMID:9828858

  18. Infrared Thermographic Profiles Of Vessel Sealing Devices On Thyroid Parenchyma

    PubMed Central

    Smith, Carter T.; Zarebczan, Barbara; Alhefdhi, Amal; Chen, Herbert

    2011-01-01

    Introduction During thyroid lobectomy, division of the thyroid parenchyma has traditionally been accomplished using suture ligation. Development of hemostatic techniques in the forms of ultrasonic dissection (UD) and electronic vessel sealing (EVS) have increased the usage of these devices during thyroid operations. We sought to characterize the thermal profile of each of these devices when used to divide the parenchyma of the thyroid gland. Methods Using a porcine model, the parenchyma of the gland was then sealed by alternating application of the UD and EVS devices. In each case the thermal activity was recorded using infrared thermal imaging. We performed multiple seals with each instrument and then compared the thermal profiles. Results There was no significant difference in lateral thermal spread of EVS and UD above 39, 40 or 60 degrees Celsius (2.30±0.31mm vs. 2.53±0.47mm, P=0.26; 2.22±0.27mm vs. 2.47±0.47mm, P=0.22; and 1.37±0.27mm vs. 1.54±0.26mm, P=0.22). There was no significant difference in mean time above 39, or 40 degrees Celsius (35.1±8.7s vs. 31.7±9.3s, p=0.47 and 29.9±8.1s vs. 27.3±6.7s, p=0.50). UD reached a greater maximum temperature (179.12±0.0008C vs. 96.52±5.6C, p=<0.001) and stayed over 60 degrees Celcius for longer than EVS (9.5±1.8s vs. 5.3±0.97s, p=<0.001). Conclusions The amount of lateral spread of thermal energy was not significantly different between the UD and EVS devices. However, the use of UD produced a higher maximum temperature during thyroid parenchyma sealing and remained above 60 degrees longer than EVS. This may translate into greater thermal injury to thyroid and surrounding tissues during division. PMID:21529840

  19. DMD and IL1RAPL1: two large adjacent genes localized within a common fragile site (FRAXC) have reduced expression in cultured brain tumors.

    PubMed

    McAvoy, S; Ganapathiraju, S; Perez, D S; James, C D; Smith, D I

    2007-01-01

    Common fragile sites (CFSs) are large regions of profound genomic instability found in all individuals. Spanning the center of the two most frequently expressed CFS regions, FRA3B (3p14.3) and FRA16D (16q23.2), are the 1.5 Mb FHIT gene and the 1.0 Mb WWOX gene. These genes are frequently deleted and/or altered in many different cancers. Both FHIT and WWOX have been demonstrated to function as tumor suppressors, both in vitro and in vivo. A number of other large CFS genes have been identified and are also frequently inactivated in multiple cancers. Based on these data, several additional very large genes were tested to determine if they were derived from within CFS regions, but DCC and RAD51L1 were not. However, the 2.0 Mb DMD gene and its immediately distal neighbor, the 1.8 Mb IL1RAPL1 gene are CFS genes contained within the FRAXC CFS region (Xp21.2-->p21.1). They are abundantly expressed in normal brain but were dramatically underexpressed in every brain tumor cell line and xenograft (derived from an intracranial model of glioblastoma multiforme) examined. We studied the expression of eleven other large CFS genes in the same panel of brain tumor cell lines and xenografts and found reduced expression of multiple large CFS genes in these samples. In this report we show that there is selective loss of specific large CFS genes in different cancers that does not appear to be mediated by the relative instability within different CFS regions. Further, the inactivation of multiple large CFS genes in xenografts and brain tumor cell lines may help to explain why this type of cancer is highly aggressive and associated with a poor clinical outcome.

  20. Assessing Conifer Ray Parenchyma for Ecological Studies: Pitfalls and Guidelines

    PubMed Central

    von Arx, Georg; Arzac, Alberto; Olano, José M.; Fonti, Patrick

    2015-01-01

    Ray parenchyma is an essential tissue for tree functioning and survival. This living tissue plays a major role for storage and transport of water, nutrients, and non-structural carbohydrates (NSC), thus regulating xylem hydraulics and growth. However, despite the importance of rays for tree carbon and water relations, methodological challenges hamper knowledge about ray intra- and inter-tree variability and its ecological meaning. In this study we provide a methodological toolbox for soundly quantifying spatial and temporal variability of different ray features. Anatomical ray features were surveyed in different cutting planes (cross-sectional, tangential, and radial) using quantitative image analysis on stem-wood micro-sections sampled from 41 mature Scots pines (Pinus sylvestris). The percentage of ray surface (PERPAR), a proxy for ray volume, was compared among cutting planes and between early- and latewood to assess measurement-induced variability. Different tangential ray metrics were correlated to assess their similarities. The accuracy of cross-sectional and tangential measurements for PERPAR estimates as a function of number of samples and the measured wood surface was assessed using bootstrapping statistical technique. Tangential sections offered the best 3D insight of ray integration into the xylem and provided the most accurate estimates of PERPAR, with 10 samples of 4 mm2 showing an estimate within ±6.0% of the true mean PERPAR (relative 95% confidence interval, CI95), and 20 samples of 4 mm2 showing a CI95 of ±4.3%. Cross-sections were most efficient for establishment of time series, and facilitated comparisons with other widely used xylem anatomical features. Earlywood had significantly lower PERPAR (5.77 vs. 6.18%) and marginally fewer initiating rays than latewood. In comparison to tangential sections, PERPAR was systematically overestimated (6.50 vs. 4.92%) and required approximately twice the sample area for similar accuracy. Radial cuttings

  1. Aberrant hepatic arteries running through pancreatic parenchyma encountered during pancreatoduodenectomy

    PubMed Central

    Wang, Lei; Xu, Jianwei; Sun, Dong; Zhang, Zongli

    2016-01-01

    Abstract Background: Aberrant hepatic arteries (HAs) encountered during pancreatoduodenectomy are difficult to manage. Mehtods: Two cases with rare types of aberrant HA running through the pancreatic parenchyma were reviewed. Results: The first case, a 68-year-old man, was admitted with obstructive jaundice. A tumor of the pancreatic head and aberrant HAs were suspected on computed tomography (CT) scan. At laparotomy, a new variation was identified; namely, 2 aberrant arteries—a right replaced HA and middle HA (RMHA) that both originated from the superior mesenteric artery (SMA) and ran via intrapancreatic paths posterior and anterior to the pancreatic head, respectively. Branches of the RMHA to the pancreas were ligated and severed and the trunk preserved. The RMHA was mistakenly identified as an aberrant left HA (RLHA), whereas the RLHA was overlooked and not dissected intraoperatively. CT angiography performed 11 days postoperatively identified that the RLHA originated from the left gastric artery (LGA). The second case had a variation of Michels IX. A 58-year-old woman presented with obstructive jaundice and a distal cholangiocarcinoma was suspected on the basis of enhanced CT scan. At laparotomy, the common hepatic artery (CHA) was found to originate entirely from the SMA and run posterior to the pancreatic head via an intrapancreatic path. The segment of CHA in the pancreatic parenchyma was removed and reconstructed with the LGA. Conclusions: Preoperative identification of aberrant HAs helps in planning appropriate operative procedures and minimizing unnecessary complications. Both preservation and reconstruction of these arteries are technically safe and feasible; however, preservation is preferable. PMID:27930504

  2. Low-dose high-resolution CT of lung parenchyma

    SciTech Connect

    Zwirewich, C.V.; Mayo, J.R.; Mueller, N.L. )

    1991-08-01

    To evaluate the efficacy of low-dose high-resolution computed tomography (HRCT) in the assessment of lung parenchyma, three observers reviewed the scans of 31 patients. The 1.5-mm-collimation, 2-second, 120-kVp scans were obtained at 20 and 200 mA at selected identical levels in the chest. The observers evaluated the visualization of normal pulmonary anatomy, various parenchymal abnormalities and their distribution, and artifacts. The low-dose and conventional scans were equivalent in the evaluation of vessels, lobar and segmental bronchi, and anatomy of secondary pulmonary lobules, and in characterizing the extent and distribution of reticulation, honeycomb cysts, and thickened interlobular septa. The low-dose technique failed to demonstrate ground-glass opacity in two of 10 cases (20%) and emphysema in one of nine cases (11%), in which they were evident but subtle on the high-dose scans. These differences were not statistically significant. Linear streak artifact was more prominent on images acquired with the low-dose technique, but the two techniques were judged equally diagnostic in 97% of cases. The authors conclude that HRCT images acquired at 20 mA yield anatomic information equivalent to that obtained with 200-mA scans in the majority of patients, without significant loss of spatial resolution or image degradation due to linear streak artifact.

  3. Lung parenchyma remodeling in acute respiratory distress syndrome.

    PubMed

    Rocco, P R M; Dos Santos, C; Pelosi, P

    2009-12-01

    Acute respiratory distress syndrome (ARDS), the most severe manifestation of acute lung injury (ALI), is described as a stereotyped response to lung injury with a transition from alveolar capillary damage to a fibroproliferative phase. Most ARDS patients survive the acute initial phase of lung injury and progress to either reparation of the lesion or evolution of the syndrome. Despite advances in the management of ARDS, mortality remains high (40%) and autopsies show extended pulmonary fibrosis in 55% of patients, suggesting the importance of deregulated repair in the morbidity and mortality of these patients. Factors influencing progression to fibroproliferative ARDS versus resolution and reconstitution of the normal pulmonary parenchymal architecture are poorly understood. Abnormal repair and remodeling may be profoundly affected by both environmental and genetic factors. In this line, mechanical ventilation may affect the macromolecules that constitute the extracellular matrix (collagen, elastin, fibronectin, laminin, proteoglycan and glycosaminoglycans), suffer changes and impact the biomechanical behavior of lung parenchyma. Furthermore, evidence suggests that acute inflammation and fibrosis may be partially independent and/or interacting processes that are autonomously regulated, and thus amenable to individual and specific therapies. In this review, we explore recent advances in the field of fibroproliferative ARDS/ALI, with special emphasis on 1) the physiological properties of the extracellular matrix, 2) the mechanisms of remodeling, 3) the impact of mechanical ventilation on lung fibrotic response, and (4) therapeutic interventions in the remodeling process.

  4. Parenchyma cell respiration and survival in secondary xylem: does metabolic activity decline with cell age?

    PubMed

    Spicer, R; Holbrook, N M

    2007-08-01

    Sapwood respiration often declines towards the sapwood/heartwood boundary, but it is not known if parenchyma metabolic activity declines with cell age. We measured sapwood respiration in five temperate species (sapwood age range of 5-64 years) and expressed respiration on a live cell basis by quantifying living parenchyma. We found no effect of parenchyma age on respiration in two conifers (Pinus strobus, Tsuga canadensis), both of which had significant amounts of dead parenchyma in the sapwood. In angiosperms (Acer rubrum, Fraxinus americana, Quercus rubra), both bulk tissue and live cell respiration were reduced by about one-half in the oldest relative to the youngest sapwood, and all sapwood parenchyma remained alive. Conifers and angiosperms had similar bulk tissue respiration despite a smaller proportion of parenchyma in conifers (5% versus 15-25% in angiosperms), such that conifer parenchyma respired at rates about three times those of angiosperms. The fact that 5-year-old parenchyma cells respired at the same rate as 25-year-old cells in conifers suggests that there is no inherent or intrinsic decline in respiration as a result of cellular ageing. In contrast, it is not known whether differences observed in cellular respiration rates of angiosperms are a function of age per se, or whether active regulation of metabolic rate or positional effects (e.g. proximity to resources and/or hormones) could be the cause of reduced respiration in older sapwood.

  5. Male donor-derived cells in the brains of female sex-mismatched bone marrow transplant recipients: a Y-chromosome specific in situ hybridization study.

    PubMed

    Unger, E R; Sung, J H; Manivel, J C; Chenggis, M L; Blazar, B R; Krivit, W

    1993-09-01

    In five female bone marrow transplant (BMT) recipients of sex-mismatched donor marrow, Y-chromosome specific in situ hybridization was performed on formalin-fixed, paraffin-embedded sections of the medulla to detect the male donor marrow-derived cells. Y-chromosome-bearing cells (Y-cells), thereby donor-derived, were matched with leukocyte common antigen (LCA)-reactive cells in adjacent sections immunostained with anti-LCA antibody. Y-cells included mononuclear leukocytes (MNL) within the vessel lumen and infiltrating the perivascular space and parenchyma, and "perivascular cells." We have, therefore, concluded that donor marrow-derived MNL, though limited in number, do enter the normal-appearing brain and can transform to "perivascular cells" in human BMT recipients. It remains, however, to be confirmed whether MNL entering the normal adult CNS parenchyma transform to ramified microglia.

  6. First insights into the functional role of vasicentric tracheids and parenchyma in eucalyptus species with solitary vessels: do they contribute to xylem efficiency or safety?

    PubMed

    Barotto, Antonio José; Fernandez, María Elena; Gyenge, Javier; Meyra, Ariel; Martinez-Meier, Alejandro; Monteoliva, Silvia

    2016-12-01

    The relationship between hydraulic specific conductivity (ks) and vulnerability to cavitation (VC) with size and number of vessels has been studied in many angiosperms. However, few of the studies link other cell types (vasicentric tracheids (VT), fibre-tracheids, parenchyma) with these hydraulic functions. Eucalyptus is one of the most important genera in forestry worldwide. It exhibits a complex wood anatomy, with solitary vessels surrounded by VT and parenchyma, which could serve as a good model to investigate the functional role of the different cell types in xylem functioning. Wood anatomy (several traits of vessels, VT, fibres and parenchyma) in conjunction with maximum ks and VC was studied in adult trees of commercial species with medium-to-high wood density (Eucalyptus globulus Labill., Eucalyptus viminalis Labill. and Eucalyptus camaldulensis Dehnh.). Traits of cells accompanying vessels presented correlations with functional variables suggesting that they contribute to both increasing connectivity between adjacent vessels-and, therefore, to xylem conduction efficiency-and decreasing the probability of embolism propagation into the tissue, i.e., xylem safety. All three species presented moderate-to-high resistance to cavitation (mean P50 values = -2.4 to -4.2 MPa) with no general trade-off between efficiency and safety at the interspecific level. The results in these species do not support some well-established hypotheses of the functional meaning of wood anatomy.

  7. Role of intracellular contents to facilitate supercooling capability in beech (Fagus crenata) xylem parenchyma cells.

    PubMed

    Kasuga, Jun; Mizuno, Kaoru; Miyaji, Natsuko; Arakawa, Keita; Fujikawa, Seizo

    2006-01-01

    In order to find the possible role of intracellular contents in facilitating the supercooling capability of xylem parenchyma cells, changes in the temperature of supercooling levels were compared before and after the release of intracellular substances from beech xylem parenchyma cells by DTA. Various methods were employed to release intracellular substances from xylem parenchyma cells and all resulted in a reduction of supercooling ability. It was concluded that the reduction of supercooling ability primarily resulted from changes of intracellular conditions, including the release of intracellular contents or their mixing with extracellular solutions, rather than due to changes of cell wall structures. It is therefore suggested that any unidentified intracellular contents may function to facilitate supercooling capability in xylem parenchyma cells.

  8. Hepatitis C virus load in parenchyma cells correlates with hepatic injury in infected patients

    PubMed Central

    Xu, Zhen; Lin, Ji-Zong; Lin, Guo-Li; Wei, Fang-Fang; Liu, Jing; Zhao, Zhi-Xin; Zhang, Ying; Ke, Wei-Ming; Zhang, Xiao-Hong

    2017-01-01

    The association between serum hepatitis C virus (HCV) load and hepatic injury in HCV-infected patients has been extensively investigated. The present study aimed to investigate the association between HCV load in hepatic parenchyma cells and hepatic injury in HCV-infected patients. A total of 56 HCV-infected patients were included in the present retrospective study. The serum HCV mRNA was determined using quantitative polymerase chain reaction, while the hepatic parenchyma cell volume and HCV mRNA in hepatic parenchyma cells were also determined. Hepatic injury was evaluated on the basis of the severity of inflammation and fibrosis. The results demonstrated that there were evident differences in the mean serum HCV RNA levels and the HCV load/parenchyma cell volume among the various grades of hepatic inflammation (G1-G4) when groups with the least and most inflammation were compared (G1 vs. G4; P<0.05). Significant differences in the HCV load existed between groups divided according to the fibrosis grade; in addition, differences existed between fibrosis grades S1 and S2, and S2 and S4 when comparing serum HCV RNA levels (P<0.05). Similarly, differences existed between every two fibrosis stages (S0 vs. S4, S2 vs. S3, and S2 vs. S4; P<0.05) when viral loads and parenchyma cell volumes were compared (F=2.860, P<0.05). Furthermore, the fibrosis staging was correlated with the viral load/parenchyma cell volume (F=2.670, P<0.05). In conclusion, hepatic fibrosis grade was found to be associated with HCV load in parenchyma cells. The results of the present study demonstrated that the viral load in parenchyma cells is a more appropriate index compared with the serum viral load for evaluating HCV replication in hepatocytes, and may function as an important factor in HCV-infected hepatic injury evaluation. PMID:28123484

  9. Hepatitis C virus load in parenchyma cells correlates with hepatic injury in infected patients.

    PubMed

    Xu, Zhen; Lin, Ji-Zong; Lin, Guo-Li; Wei, Fang-Fang; Liu, Jing; Zhao, Zhi-Xin; Zhang, Ying; Ke, Wei-Ming; Zhang, Xiao-Hong

    2017-01-01

    The association between serum hepatitis C virus (HCV) load and hepatic injury in HCV-infected patients has been extensively investigated. The present study aimed to investigate the association between HCV load in hepatic parenchyma cells and hepatic injury in HCV-infected patients. A total of 56 HCV-infected patients were included in the present retrospective study. The serum HCV mRNA was determined using quantitative polymerase chain reaction, while the hepatic parenchyma cell volume and HCV mRNA in hepatic parenchyma cells were also determined. Hepatic injury was evaluated on the basis of the severity of inflammation and fibrosis. The results demonstrated that there were evident differences in the mean serum HCV RNA levels and the HCV load/parenchyma cell volume among the various grades of hepatic inflammation (G1-G4) when groups with the least and most inflammation were compared (G1 vs. G4; P<0.05). Significant differences in the HCV load existed between groups divided according to the fibrosis grade; in addition, differences existed between fibrosis grades S1 and S2, and S2 and S4 when comparing serum HCV RNA levels (P<0.05). Similarly, differences existed between every two fibrosis stages (S0 vs. S4, S2 vs. S3, and S2 vs. S4; P<0.05) when viral loads and parenchyma cell volumes were compared (F=2.860, P<0.05). Furthermore, the fibrosis staging was correlated with the viral load/parenchyma cell volume (F=2.670, P<0.05). In conclusion, hepatic fibrosis grade was found to be associated with HCV load in parenchyma cells. The results of the present study demonstrated that the viral load in parenchyma cells is a more appropriate index compared with the serum viral load for evaluating HCV replication in hepatocytes, and may function as an important factor in HCV-infected hepatic injury evaluation.

  10. The Effect of Sunlight in Parenchyma Pith Cells Diameter of Manihot esculenta

    NASA Astrophysics Data System (ADS)

    Susanti, D.; Aziz, D. N.; Astuti, W.; Nuraeni, E.

    2017-03-01

    Sunlight is one of the factors that effect on the grow of a plant. Manihot esculenta is one of the plants that easily found in Indonesia because its role as staple food. The aim of this research is to know the correlation between sunlight the grow of parenchyma pith cells diameter of Manihot esculenta. Independent variable in this research is sunlight, and dependent variable is the parenchyma pith cells diameter of Manihot esculenta. Data was collected is in qualitative and quantitative form. Qualitative data gotten gained by morphology observation. The parenchyma pith cells of Manihot esculenta that is affected by sunlight in 1310 x 10 Lux, morphologically has hexagon, cell walls thick, solid state, and regular composition. Meanwhile, the parenchyma pith cells that has less sunlight (363 x 10 Lux) has a hexagon shape, thin cell walls thin, soft state, and irregular composition. Qualitative data suported by quantitative data. The size of parenchyma pith cells diameter that is affected by sunlight in 1310 x 10 Lux 96,4 µm. While, the stem parenchyma pith cells diameter empulur that has less sunlight (363 x 10 Lux) is 129,8 µm.

  11. High accumulation of soluble sugars in deep supercooling Japanese white birch xylem parenchyma cells.

    PubMed

    Kasuga, Jun; Arakawa, Keita; Fujikawa, Seizo

    2007-01-01

    Seasonal changes in the accumulation of soluble sugars in extracellular freezing cortical parenchyma cells and deep supercooling xylem parenchyma cells in Japanese white birch (Betula platyphylla var. japonica) were compared to identify the effects of soluble sugars on the mechanism of deep supercooling, which keeps the liquid state of water in cells under extremely low temperatures for long periods. Soluble sugars in both tissues were analyzed by high-performance liquid chromatography (HPLC), and the concentrations of sugars in cells were estimated by histological observation of occupancy rates of parenchyma cells in each tissue. Relative and equilibrium melting points of parenchyma cells were measured by differential thermal analysis and cryoscanning electron microscopy, respectively. In both xylem and cortical parenchyma cells, amounts of sucrose, raffinose and stachyose increased in winter, but amounts of fructose and glucose exhibited little change throughout the entire year. In addition, no sugars were found to be specific for either tissue. Combined results of HPLC analyses, histological observation and melting point analyses confirmed that the concentration of sugars was much higher in xylem cells than in cortical cells. It is thought that the higher concentration of soluble sugars in xylem cells may contribute to facilitation of deep supercooling in xylem cells by depressing the nucleation temperature.

  12. Pulsed ultrasound expands the extracellular and perivascular spaces of the brain.

    PubMed

    Hersh, David S; Nguyen, Ben A; Dancy, Jimena G; Adapa, Arjun R; Winkles, Jeffrey A; Woodworth, Graeme F; Kim, Anthony J; Frenkel, Victor

    2016-09-01

    Diffusion within the extracellular and perivascular spaces of the brain plays an important role in biological processes, therapeutic delivery, and clearance mechanisms within the central nervous system. Recently, ultrasound has been used to enhance the dispersion of locally administered molecules and particles within the brain, but ultrasound-mediated effects on the brain parenchyma remain poorly understood. We combined an electron microscopy-based ultrastructural analysis with high-resolution tracking of non-adhesive nanoparticles in order to probe changes in the extracellular and perivascular spaces of the brain following a non-destructive pulsed ultrasound regimen known to alter diffusivity in other tissues. Freshly obtained rat brain neocortical slices underwent sham treatment or pulsed, low intensity ultrasound for 5min at 1MHz. Transmission electron microscopy revealed intact cells and blood vessels and evidence of enlarged spaces, particularly adjacent to blood vessels, in ultrasound-treated brain slices. Additionally, ultrasound significantly increased the diffusion rate of 100nm, 200nm, and 500nm nanoparticles that were injected into the brain slices, while 2000nm particles were unaffected. In ultrasound-treated slices, 91.6% of the 100nm particles, 20.7% of the 200nm particles, 13.8% of the 500nm particles, and 0% of the 2000nm particles exhibited diffusive motion. Thus, pulsed ultrasound can have meaningful structural effects on the brain extracellular and perivascular spaces without evidence of tissue disruption.

  13. Developmental changes in cell and tissue water relations parameters in storage parenchyma of sugarcane

    SciTech Connect

    Moore, P.H. ); Cosgrove, D.J. )

    1991-07-01

    The osmotic pressure of the cell sap of stalk storage parenchyma of sugarcane (Saccharum spp. hybrids) increases by an order of magnitude during ontogeny to reach molar concentrations of sucrose at maturity. Stalk parenchyma cells must either experience very high turgor at maturation of have an ability to regulate turgor. The authors tested this hypothesis by using pressure probe techniques to quantify parameters of cell and tissue water relations of sugarcane storage parenchyma during ontogeny. The largest developmental change was in the volumetric elastic modulus, which increased from 6 bars in immature tissue to 43 bars in mature tissue. Turgor was maintained relatively low during sucrose accumulation by the partitioning of solutes between the cell and wall compartments. Membrane hydraulic conductivity decreased from about 12 {times} 10{sup {minus}7} centimeters per second per bar down to 4.4 {times} 10{sup {minus}7} centimeters per second per bar. The 2.7-fold decrease in membrane hydraulic conductivity during tissue maturation was accompanied by a 7.8-fold increase in wall elasticity. Integration of the cell and wall membrane properties appears to be by the opposing effects of turgor on hydraulic conductivity and elastic modulus. The changes in these properties during development of sugarcane stalk tissue may be a way for parenchyma cells to develop a capacity for expansive growth and still serve as a strong sink for storing high concentrations of sucrose.

  14. The functional role of xylem parenchyma cells and aquaporins during recovery from severe water stress.

    PubMed

    Secchi, Francesca; Pagliarani, Chiara; Zwieniecki, Maciej A

    2016-09-15

    Xylem parenchyma cells [vessel associated cells (VACs)] constitute a significant fraction of the xylem in woody plants. These cells are often closely connected with xylem vessels or tracheids via simple pores (remnants of plasmodesmata fields). The close contact and biological activity of VACs during times of severe water stress and recovery from stress suggest that they are involved in the maintenance of xylem transport capacity and responsible for the restoration of vessel/tracheid functionality following embolism events. As recovery from embolism requires the transport of water across xylem parenchyma cell membranes, an understanding of stem-specific aquaporin expression patterns, localization and activity is a crucial part of any biological model dealing with embolism recovery processes in woody plants. In this review, we provide a short overview of xylem parenchyma cell biology with a special focus on aquaporins. In particular we address their distributions and activity during the development of drought stress, during the formation of embolism and the subsequent recovery from stress that may result in refilling. Complemented by the current biological model of parenchyma cell function during recovery from stress, this overview highlights recent breakthroughs on the unique ability of long-lived perennial plants to undergo cycles of embolism-recovery related to drought/rewetting or freeze/thaw events.

  15. A global analysis of parenchyma tissue fractions in secondary xylem of seed plants.

    PubMed

    Morris, Hugh; Plavcová, Lenka; Cvecko, Patrick; Fichtler, Esther; Gillingham, Mark A F; Martínez-Cabrera, Hugo I; McGlinn, Daniel J; Wheeler, Elisabeth; Zheng, Jingming; Ziemińska, Kasia; Jansen, Steven

    2016-03-01

    Parenchyma is an important tissue in secondary xylem of seed plants, with functions ranging from storage to defence and with effects on the physical and mechanical properties of wood. Currently, we lack a large-scale quantitative analysis of ray parenchyma (RP) and axial parenchyma (AP) tissue fractions. Here, we use data from the literature on AP and RP fractions to investigate the potential relationships of climate and growth form with total ray and axial parenchyma fractions (RAP). We found a 29-fold variation in RAP fraction, which was more strongly related to temperature than with precipitation. Stem succulents had the highest RAP values (mean ± SD: 70.2 ± 22.0%), followed by lianas (50.1 ± 16.3%), angiosperm trees and shrubs (26.3 ± 12.4%), and conifers (7.6 ± 2.6%). Differences in RAP fraction between temperate and tropical angiosperm trees (21.1 ± 7.9% vs 36.2 ± 13.4%, respectively) are due to differences in the AP fraction, which is typically three times higher in tropical than in temperate trees, but not in RP fraction. Our results illustrate that both temperature and growth form are important drivers of RAP fractions. These findings should help pave the way to better understand the various functions of RAP in plants.

  16. Comparative analysis of inhaled particles contained in human bronchoalveolar lavage fluids, lung parenchyma and lymph nodes.

    PubMed Central

    Dumortier, P; De Vuyst, P; Yernault, J C

    1994-01-01

    Translocation of inhaled particles from the alveolar spaces to lung parenchyma and lymph nodes is one of the mechanisms that determine the biopersistence of particles. This study compares the nonfibrous particulate burden in bronchoalveolar lavage (BAL) fluids, lung parenchyma, and thoracic lymph nodes and attempts to detect the degree of differentiation, if any, based on particle size or type. This comparison can only be done on BAL, lung parenchyma, and lymph node samples collected from the same subject over a short time. Patients undergoing surgical lung resection are suitable for this purpose. Particles recovered by digestion-filtration were counted, sized, and analyzed by analytical transmission electron microscopy. Total particle load ranges grossly between 10(5) to 10(7) p/ml in BAL, 10(9) to 10(10) p/g dry tissue in parenchyma and 10(10) to 10(11) p/g dry tissue in lymph nodes. Diameters are log-normally distributed and mean diameters range between 0.5 to 0.9 micron. Nonlamellar silicate particles have a significantly larger diameter in lymph nodes. Differences in particle type between the three sampling sites are small and nonsystematic. PMID:7882946

  17. Developmental changes in cell and tissue water relations parameters in storage parenchyma of sugarcane.

    PubMed

    Moore, P H; Cosgrove, D J

    1991-01-01

    The osmotic pressure of the cell sap of stalk storage parenchyma of sugarcane (Saccharum spp. hybrids) increases by an order of magnitude during ontogeny to reach molar concentrations of sucrose at maturity. Stalk parenchyma cells must either experience very high turgor at maturation or have an ability to regulate turgor. We tested this hypothesis by using pressure probe techniques to quantify parameters of cell and tissue water relations of sugarcane storage parenchyma during ontogeny. The largest developmental change was in the volumetric elastic modulus, which increased from 6 bars in immature tissue to 43 bars in mature tissue. Turgor was maintained relatively low during sucrose accumulation by the partitioning of solutes between the cell and wall compartments. Membrane hydraulic conductivity decreased from about 12 x 10(-7) centimeters per second per bar down to 4.4 x 10(-7) centimeters per second per bar. The 2.7-fold decrease in membrane hydraulic conductivity during tissue maturation was accompanied by a 7.8-fold increase in wall elasticity. Integration of the cell wall and membrane properties appears to be by the opposing effects of turgor on hydraulic conductivity and elastic modulus. The changes in these properties during development of sugarcane stalk tissue may be a way for parenchyma cells to develop a capacity for expansive growth and still serve as a strong sink for storing high concentrations of sucrose.

  18. Comparison of celery (Apium graveolens L.) collenchyma and parenchyma cell wall polysaccharides enabled by solid-state (13)C NMR.

    PubMed

    Zujovic, Zoran; Chen, Da; Melton, Laurence D

    2016-02-01

    Collenchyma cells with their thickened walls are one of specific mechanical support tissues for plants, while parenchyma cells are thin walled and serve multiple functions. The parenchyma tissue is what you enjoy eating, while collenchyma, because of its fibrous nature, is not so attractive. Celery is a useful model for comparing the cell walls (CWs) of the two cell types such as collenchyma and parenchyma. However, to date, the structural characteristics of collenchyma and parenchyma cell walls from the same plant have not been compared. Monosaccharide composition suggested the collenchyma cell walls contained less pectin but more hemicellulose in comparison to parenchyma. High-resolution solid-state NMR spectra of highly mobile pectins revealed that the arabinan signals were more evident in the collenchyma spectrum, while galactan showed a much stronger resonance in the parenchyma spectrum. In addition, methyl esterified and non-esterified galacturonic acid signals were observed in parenchyma CWs, but only the latter one appeared in the collenchyma. The ratio of cellulose surface/interior obtained from CP/MAS spectra for collenchyma suggested the cellulose microfibrils were ~2.4 nm, while in the parenchyma, these were somewhat larger. X-ray diffraction indicated the size of the cellulose microfibrils were the same for both types of CWs.

  19. Isolation and characterization of cellulose nanocrystals from parenchyma and vascular bundle of oil palm trunk (Elaeis guineensis).

    PubMed

    Lamaming, Junidah; Hashim, Rokiah; Leh, Cheu Peng; Sulaiman, Othman; Sugimoto, Tomoko; Nasir, Mohammed

    2015-12-10

    In this study cellulose nanocrystals were isolated through acid hydrolysis process from parenchyma and vascular bundle of oil palm trunk (Elaeis guineensis). The morphological properties of obtained cellulose nanocrystals were studied by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The microscopy images showed smoother and cleaner surface of parenchyma cellulose nanocrystals when compared to vascular bundle cellulose nanocrystals. The TEM image shows a higher length and diameter for parenchyma cellulose nanocrystals compared to vascular bundle cellulose nanocrystals. The Fourier transform infrared (FTIR) spectra showed changes in functional groups after acid hydrolysis due to removal of lignin, hemicelluloses and other impurities in both type of cellulose nanocrystals. Crystallinity index of cellulose nanocrystals was observed higher for vascular bundle as compared to parenchyma. Thermogravimetric analysis (TGA) was performed to study the thermal stability of cellulose nanocrystals and it was observed higher for parenchyma cellulose nanocrystals compared to vascular bundle.

  20. In vivo quantification of motion in liver parenchyma and its application in shistosomiasis tissue characterization

    NASA Astrophysics Data System (ADS)

    Badawi, Ahmed M.; Hashem, Ahmed M.; Youssef, Abou-Bakr M.; Abdel-Wahab, Mohamed F.

    1995-03-01

    Schistosomiasis is a major problem in Egypt, despite an active control program it is estimated to exist in about 1/3 of the population. Deposition of less functioning fibrous tissues in the liver is the major contributory factor to the hepatic pathology. Fibrous tissues consist of a complex array of connective matrix material and a variety of collagen isotopes. As a result of an increased stromal density (collagen content), the parenchyma became more ectogenic and less elastic (hard). In this study we investigated the effect of cardiac mechanical impulses from the heart and aorta on the kinetics of the liver parenchyma. Under conditions of controlled patient movements and suspended respiration, a 30 frame per second of 588 X 512 ultrasound images (cineloop, 32 pels per cm) are captured from an aTL ultrasound machine then digitized. The image acquisition is triggered by the R wave of the ECG of the patient. The motion that has a forced oscillation form in the liver parenchyma is quantified by tracking of small box (20 - 30 pels) in 16 directions for all the successive 30 frames. The tracking was done using block matching techniques (the max correlation between boxes in time, frequency domains, and the minimum SAD (sum absolute difference) between boxes). The motion is quantified for many regions at different positions within the liver parenchyma for 80 cases of variable degrees of schisto., cirrhotic livers, and for normal livers. The velocity of the tissue is calculated from the displacement (quantified motion), time between frames, and the scan time for the ultrasound scanner. We found that the motion in liver parenchyma is small in the order of very few millimeters, and the attenuation of the mechanical wave for one ECG cycle is higher in the schisto. and cirrhotic livers than in the normal ones. Finally quantification of motion in liver parenchyma due to cardiac impulses under controlled limb movement and respiration may be of value in the characterization of

  1. Computational modeling of an endovascular approach to deep brain stimulation

    NASA Astrophysics Data System (ADS)

    Teplitzky, Benjamin A.; Connolly, Allison T.; Bajwa, Jawad A.; Johnson, Matthew D.

    2014-04-01

    Objective. Deep brain stimulation (DBS) therapy currently relies on a transcranial neurosurgical technique to implant one or more electrode leads into the brain parenchyma. In this study, we used computational modeling to investigate the feasibility of using an endovascular approach to target DBS therapy. Approach. Image-based anatomical reconstructions of the human brain and vasculature were used to identify 17 established and hypothesized anatomical targets of DBS, of which five were found adjacent to a vein or artery with intraluminal diameter ≥1 mm. Two of these targets, the fornix and subgenual cingulate white matter (SgCwm) tracts, were further investigated using a computational modeling framework that combined segmented volumes of the vascularized brain, finite element models of the tissue voltage during DBS, and multi-compartment axon models to predict the direct electrophysiological effects of endovascular DBS. Main results. The models showed that: (1) a ring-electrode conforming to the vessel wall was more efficient at neural activation than a guidewire design, (2) increasing the length of a ring-electrode had minimal effect on neural activation thresholds, (3) large variability in neural activation occurred with suboptimal placement of a ring-electrode along the targeted vessel, and (4) activation thresholds for the fornix and SgCwm tracts were comparable for endovascular and stereotactic DBS, though endovascular DBS was able to produce significantly larger contralateral activation for a unilateral implantation. Significance. Together, these results suggest that endovascular DBS can serve as a complementary approach to stereotactic DBS in select cases.

  2. MR imaging of pulmonary parenchyma and emboli by paramagnetic and superparamagnetic contrast agents.

    PubMed

    Thakur, M L; Vinitski, S; Mitchell, D G; Consigny, P M; Lin, S; DeFulvio, J; Rifkin, M

    1990-01-01

    Using experimentally induced pulmonary emboli in an animal model, three intravenously administered contrast agents, Gd-DTPA-albumin microspheres (8-15 microns, 0.2 M particles/mg protein, 39-106 micrograms Gd/mg, 50 mg/ml), Gd-DTPA-liposomes (15-30 microns, 130 micrograms/mg lipid, 6 mg Gd/ml) and superparamagnetic ferrosome, (60 nm, 100 mM iron and 20 mg lipid/ml) were examined for MR imaging. Gd-DTPA entrapped in lung capillaries did not enhance the signal intensity of lung parenchyma, but liposomes (5 ml) served as better Gd-DTPA carriers and increased the parenchymal signal intensity by up to a factor of 2.3. However, neither agent improved delineation of pulmonary emboli. Ferrosome decreased the intensity of lung parenchyma, improving detectability of pulmonary emboli by several factors.

  3. Performance assessment of an opto-fluidic phantom mimicking porcine liver parenchyma

    NASA Astrophysics Data System (ADS)

    Akl, Tony J.; King, Travis J.; Long, Ruiqi; McShane, Michael J.; Nance Ericson, M.; Wilson, Mark A.; Coté, Gerard L.

    2012-07-01

    An implantable, optical oxygenation and perfusion sensor to monitor liver transplants during the two-week period following the transplant procedure is currently being developed. In order to minimize the number of animal experiments required for this research, a phantom that mimics the optical, anatomical, and physiologic flow properties of liver parenchyma is being developed as well. In this work, the suitability of this phantom for liver parenchyma perfusion research was evaluated by direct comparison of phantom perfusion data with data collected from in vivo porcine studies, both using the same prototype perfusion sensor. In vitro perfusion and occlusion experiments were performed on a single-layer and on a three-layer phantom perfused with a dye solution possessing the absorption properties of oxygenated hemoglobin. While both phantoms exhibited response patterns similar to the liver parenchyma, the signal measured from the multilayer phantom was three times higher than the single layer phantom and approximately 21 percent more sensitive to in vitro changes in perfusion. Although the multilayer phantom replicated the in vivo flow patterns more closely, the data suggests that both phantoms can be used in vitro to facilitate sensor design.

  4. A rare extramedullary involvement in myeloma: lung parenchyma and association with unfavorable chromosomal abnormalities.

    PubMed

    Şahin Balçık, Özlem; Albayrak, Murat; Dağdaş, Simten; Ceran, Funda; Özet, Gülsüm; Demirağ, Funda; Yokuş, Osman

    2010-06-05

    Although pulmonary complications developing secondary to lung infections and involvement in ribs occur frequently in multiple myeloma (MM), involvement of the lung parenchyma is quite rare. In clinical studies, the involvement of lung parenchyma has been found to be associated with unfavorable prognosis. Here, a MM case in whom involvement of lung parenchyma was accompanied by unfavorable prognostic cytogenetic markers is presented. A 62-year-old male presented with complaint of cough, and heterogeneous hypodense mass was detected in thorax computerized tomography. The patient underwent bronchoscopic biopsy. Pathological examination revealed diffuse plasma cell infiltration staining with kappa immunohistochemically. In bone marrow biopsy, plasma cell infiltration was observed. In conventional cytogenetic examination, hypodiploidy was established. In cytogenetic examination carried out with fluorescence in situ hybridization, deletion (13q) was determined. In conclusion, in patients diagnosed with MM and presenting with pulmonary mass lesion, lung involvement associated with plasma cell infiltration should also be considered in the differential diagnosis. As overall survival is low in these cases, more aggressive treatment approaches such as high-dose treatment should be immediately considered.

  5. Brachypodium as an experimental system for the study of stem parenchyma biology in grasses.

    PubMed

    Jensen, Jacob Krüger; Wilkerson, Curtis Gene

    2017-01-01

    Stem parenchyma is a major cell type that serves key metabolic functions for the plant especially in large grasses, such as sugarcane and sweet sorghum, where it serves to store sucrose or other products of photosynthesis. It is therefore desirable to understand the metabolism of this cell type as well as the mechanisms by which it provides its function for the rest of the plant. Ultimately, this information can be used to selectively manipulate this cell type in a controlled manner to achieve crop improvement. In this study, we show that Brachypodium distachyon is a useful model system for stem pith parenchyma biology. Brachypodium can be grown under condition where it resembles the growth patterns of important crops in that it produces large amounts of stem material with the lower leaves senescing and with significant stores of photosynthate located in the stem parenchyma cell types. We further characterize stem plastid morphology as a function of tissue types, as this organelle is central for a number of metabolic pathways, and quantify gene expression for the four main classes of starch biosynthetic genes. Notably, we find several of these genes differentially regulated between stem and leaf. These studies show, consistent with other grasses, that the stem functions as a specialized storage compartment in Brachypodium.

  6. Brachypodium as an experimental system for the study of stem parenchyma biology in grasses

    PubMed Central

    Wilkerson, Curtis Gene

    2017-01-01

    Stem parenchyma is a major cell type that serves key metabolic functions for the plant especially in large grasses, such as sugarcane and sweet sorghum, where it serves to store sucrose or other products of photosynthesis. It is therefore desirable to understand the metabolism of this cell type as well as the mechanisms by which it provides its function for the rest of the plant. Ultimately, this information can be used to selectively manipulate this cell type in a controlled manner to achieve crop improvement. In this study, we show that Brachypodium distachyon is a useful model system for stem pith parenchyma biology. Brachypodium can be grown under condition where it resembles the growth patterns of important crops in that it produces large amounts of stem material with the lower leaves senescing and with significant stores of photosynthate located in the stem parenchyma cell types. We further characterize stem plastid morphology as a function of tissue types, as this organelle is central for a number of metabolic pathways, and quantify gene expression for the four main classes of starch biosynthetic genes. Notably, we find several of these genes differentially regulated between stem and leaf. These studies show, consistent with other grasses, that the stem functions as a specialized storage compartment in Brachypodium. PMID:28248997

  7. MAGNETIC RESONANCE ELASTOGRAPHY OF HUMAN LUNG PARENCHYMA: TECHNICAL DEVELOPMENT, THEORETICAL MODELING AND IN VIVO VALIDATION

    PubMed Central

    Mariappan, Yogesh K; Glaser, Kevin J; Hubmayr, Rolf D; Manduca, Armando; Ehman, Richard L; McGee, Kiaran P

    2011-01-01

    Purpose To develop a novel MR-based method for visualizing the elastic properties of human lung parenchyma in vivo and to evaluate the ability of this method to resolve differences in parenchymal stiffness at different respiration states in healthy volunteers. Materials and Methods A spin-echo MR Elastography (MRE) pulse sequence was developed to provide both high shear wave motion sensitivity and short TE for improved visualization of lung parenchyma. The improved motion sensitivity of this approach was modeled and tested with phantom experiments. In vivo testing was then performed on ten healthy volunteers at the respiratory states of residual volume (RV) and total lung capacity (TLC). Results Shear wave propagation was visualized within the lungs of all volunteers and was processed to provide parenchymal shear stiffness maps of all ten subjects. Density corrected stiffness values at TLC (1.83 ± 0.22 kPa) were higher than those at the RV (1.14 ± 0.14 kPa) with the difference being statistically significant (p<0.0001). Conclusion 1H-based MR Elastography can noninvasively measure the shear stiffness of human lung parenchyma in vivo and can quantitate the change in shear stiffness due to respiration. The values obtained were consistent with previously reported in vitro assessments of cadaver lungs. Further work is required to increase the flexibility of the current acquisition and to investigate the clinical potential of lung MRE. PMID:21591003

  8. A Segmentation Method for Lung Parenchyma Image Sequences Based on Superpixels and a Self-Generating Neural Forest

    PubMed Central

    Liao, Xiaolei; Zhao, Juanjuan; Jiao, Cheng; Lei, Lei; Qiang, Yan; Cui, Qiang

    2016-01-01

    Background Lung parenchyma segmentation is often performed as an important pre-processing step in the computer-aided diagnosis of lung nodules based on CT image sequences. However, existing lung parenchyma image segmentation methods cannot fully segment all lung parenchyma images and have a slow processing speed, particularly for images in the top and bottom of the lung and the images that contain lung nodules. Method Our proposed method first uses the position of the lung parenchyma image features to obtain lung parenchyma ROI image sequences. A gradient and sequential linear iterative clustering algorithm (GSLIC) for sequence image segmentation is then proposed to segment the ROI image sequences and obtain superpixel samples. The SGNF, which is optimized by a genetic algorithm (GA), is then utilized for superpixel clustering. Finally, the grey and geometric features of the superpixel samples are used to identify and segment all of the lung parenchyma image sequences. Results Our proposed method achieves higher segmentation precision and greater accuracy in less time. It has an average processing time of 42.21 seconds for each dataset and an average volume pixel overlap ratio of 92.22 ± 4.02% for four types of lung parenchyma image sequences. PMID:27532214

  9. Multimodal Imaging of Pathophysiological Changes and Their Role in Development of Breast Cancer Brain Metastasis

    DTIC Science & Technology

    2010-09-01

    time when systemic disease is under good control. In part, this may be du e to the fact that chemotherapeutic agents that show efficacy against...systemic disease , may have p oor penetration of the blood-brain barrier (BBB), which means that breast cancer metastasis in the brain may remain untreated...located betw een parenchyma and leptomeninges Metastatic lesions at brain parenchyma sho wed significan tly more perfusion, as compared to those l

  10. Viscoelastic Model for Lung Parenchyma for Multi-Scale Modeling of Respiratory System, Phase II: Dodecahedral Micro-Model

    SciTech Connect

    Freed, Alan D.; Einstein, Daniel R.; Carson, James P.; Jacob, Rick E.

    2012-03-01

    In the first year of this contractual effort a hypo-elastic constitutive model was developed and shown to have great potential in modeling the elastic response of parenchyma. This model resides at the macroscopic level of the continuum. In this, the second year of our support, an isotropic dodecahedron is employed as an alveolar model. This is a microscopic model for parenchyma. A hopeful outcome is that the linkage between these two scales of modeling will be a source of insight and inspiration that will aid us in the final year's activity: creating a viscoelastic model for parenchyma.

  11. Blood-brain barrier and blood-cerebrospinal fluid barrier in normal and pathological conditions.

    PubMed

    Ueno, Masaki; Chiba, Yoichi; Murakami, Ryuta; Matsumoto, Koichi; Kawauchi, Machi; Fujihara, Ryuji

    2016-04-01

    Blood-borne substances can invade into the extracellular spaces of the brain via endothelial cells in sites without the blood-brain barrier (BBB), and can travel through the interstitial fluid (ISF) of the brain parenchyma adjacent to non-BBB sites. It has been shown that cerebrospinal fluid (CSF) drains directly into the blood via the arachnoid villi and also into lymph nodes via the subarachnoid spaces of the brain, while ISF drains into the cervical lymph nodes through perivascular drainage pathways. In addition, the glymphatic pathway of fluids, characterized by para-arterial pathways, aquaporin4-dependent passage through astroglial cytoplasm, interstitial spaces, and paravenous routes, has been established. Meningeal lymphatic vessels along the superior sagittal sinus were very recently discovered. It is known that, in mice, blood-borne substances can be transferred to areas with intact BBB function, such as the medial regions of the hippocampus, presumably through leaky vessels in non-BBB sites. In the present paper, we review the clearance mechanisms of interstitial substances, such as amyloid-β peptides, as well as summarize models of BBB deterioration in response to different types of insults, including acute ischemia followed by reperfusion, hypertension, and chronic hypoperfusion. Lastly, we discuss the relationship between perivascular clearance and brain disorders.

  12. Outdoor air pollution and risk for kidney parenchyma cancer in 14 European cohorts.

    PubMed

    Raaschou-Nielsen, Ole; Pedersen, Marie; Stafoggia, Massimo; Weinmayr, Gudrun; Andersen, Zorana J; Galassi, Claudia; Sommar, Johan; Forsberg, Bertil; Olsson, David; Oftedal, Bente; Krog, Norun H; Aasvang, Gunn Marit; Pyko, Andrei; Pershagen, Göran; Korek, Michal; De Faire, Ulf; Pedersen, Nancy L; Östenson, Claes-Göran; Fratiglioni, Laura; Sørensen, Mette; Eriksen, Kirsten T; Tjønneland, Anne; Peeters, Petra H; Bueno-de-Mesquita, H B As; Plusquin, Michelle; Key, Timothy J; Jaensch, Andrea; Nagel, Gabriele; Föger, Bernhard; Wang, Meng; Tsai, Ming-Yi; Grioni, Sara; Marcon, Alessandro; Krogh, Vittorio; Ricceri, Fulvio; Sacerdote, Carlotta; Migliore, Enrica; Tamayo, Ibon; Amiano, Pilar; Dorronsoro, Miren; Sokhi, Ranjeet; Kooter, Ingeborg; de Hoogh, Kees; Beelen, Rob; Eeftens, Marloes; Vermeulen, Roel; Vineis, Paolo; Brunekreef, Bert; Hoek, Gerard

    2017-04-01

    Several studies have indicated weakly increased risk for kidney cancer among occupational groups exposed to gasoline vapors, engine exhaust, polycyclic aromatic hydrocarbons and other air pollutants, although not consistently. It was the aim to investigate possible associations between outdoor air pollution at the residence and the incidence of kidney parenchyma cancer in the general population. We used data from 14 European cohorts from the ESCAPE study. We geocoded and assessed air pollution concentrations at baseline addresses by land-use regression models for particulate matter (PM10 , PM2.5 , PMcoarse , PM2.5 absorbance (soot)) and nitrogen oxides (NO2 , NOx ), and collected data on traffic. We used Cox regression models with adjustment for potential confounders for cohort-specific analyses and random effects models for meta-analyses to calculate summary hazard ratios (HRs). The 289,002 cohort members contributed 4,111,908 person-years at risk. During follow-up (mean 14.2 years) 697 incident cancers of the kidney parenchyma were diagnosed. The meta-analyses showed higher HRs in association with higher PM concentration, e.g. HR = 1.57 (95%CI: 0.81-3.01) per 5 μg/m(3) PM2.5 and HR = 1.36 (95%CI: 0.84-2.19) per 10(-5) m(-1) PM2.5 absorbance, albeit never statistically significant. The HRs in association with nitrogen oxides and traffic density on the nearest street were slightly above one. Sensitivity analyses among participants who did not change residence during follow-up showed stronger associations, but none were statistically significant. Our study provides suggestive evidence that exposure to outdoor PM at the residence may be associated with higher risk for kidney parenchyma cancer; the results should be interpreted cautiously as associations may be due to chance.

  13. The diagnostic value of cytokeratins expression in the renal parenchyma tumors.

    PubMed

    Alexa, Aurora; Baderca, Flavia; Lighezan, Rodica; Izvernariu, D; Raica, M

    2010-01-01

    Renal carcinomas are a heterogeneous group of tumors, difficult to classify and identify precisely. Since their prognosis depends very much upon their type, precise diagnosis might mean the difference between therapeutic success and patient death. Cytokeratins are particularly useful for the identification of the epithelial nature of the tumors, because their expression is maintained even in poorly differentiated tumors. Monoclonal cytokeratins such as CK7 and CK20 stain different components of the renal tubular system and are a useful duo for the identification of the origin of the different tumors that might arise in the kidney. Along with polyclonal cytokeratins such as AE1/AE3 and high molecular weight cytokeratin antibodies (34betaE12, Cam 5.2), epithelial membrane antigen (EMA) and vimentin, they are included in every diagnostic panel for renal tumors. We have selected 138 renal parenchyma tumor specimens, performed morphological diagnosis and then stained them with polyclonal cytokeratin antibody AE1/AE3, and monoclonal antibodies to CK7 and CK20. AE1/AE3 was expressed in 61.7% of the renal parenchyma tumors, with high intensity and percentage of positive cases in the papillary carcinomas (100%), and with rare and weakly positive cells in chromophobic cells carcinomas, clear cells carcinomas and sarcomatous carcinomas. CK7 was positive in 68% of the renal parenchyma tumors, with positive reaction in 100% of the cases of chromophobic cells and sarcomatous carcinomas. Clear cells carcinomas had the less percentage of positive cells, whereas papillary carcinomas were positive in seven out of eight cases. No difference in the staining pattern was noticed between type I and type II papillary carcinomas. CK20 was negative in all cases studied.

  14. Evaluation of airway measurements in phantom parenchyma and soft tissue regions

    NASA Astrophysics Data System (ADS)

    Ochs, Robert A.; Kim, Hyun J.; Goldin, Jonathan G.; McNitt-Gray, Michael F.; Brown, Matthew S.

    2008-03-01

    The purpose of this work was to develop a 3D airway measurement technique that can be initialized at a single point (either automatically or user defined) and to evaluate the measurement accuracy with varying imaging parameters as well as in synthetic parenchyma and soft tissue regions. This approach may have advantages over existing methods that require segmentation of the entire airway branch. METHODS: Rays are cast spherically from the initial measurement point and a range image is created of the distance to the edge of the airway lumen. The trajectory of the airway is estimated from the range image, and can be used to re-construct a 2D slice perpendicular to the airway for cross-sectional measurements. The evaluation phantom consisted of 5 tubes (3.18 to 19.05 mm in diameter and 1.59 to 3.18 mm in wall thickness) embedded in synthetic lung parenchyma and soft tissue. Images were acquired at 10 and 100 mAs at three tube orientations (0°, 45°, 90°) and were reconstructed at 0.6 and 1.5 mm slice thicknesses with both smooth and standard reconstruction kernels. RESULTS: The overall diameter and wall thickness accuracy was 0.43 +/- 0.19 mm and 0.28 +/- 0.15 mm respectively in parenchyma regions and 0.46 +/- 0.16 mm and 0.49 +/- 0.40 mm respectively in the soft tissue regions. The overall accuracy of the trajectory estimate was 0.64 +/- 0.51°. The proposed technique may allow a potentially larger number of airways to be measured for research and clinical analysis than with current methods.

  15. A large sialolith on the parenchyma of the submandibular gland: A case report

    PubMed Central

    JUNG, JAE-HOON; HONG, SUNG OK; NOH, KWANTAE; LEE, DEOK-WON

    2014-01-01

    A 45-year-old female was referred to the Department of Oral and Maxillofacial Surgery with the complaint of pain in the right submandibular region and a dry mouth, which had started one week previously. A clinical examination revealed a swelling and tenderness in the right submandibular region. Panoramic radiography and computed tomography identified a sialolith in the submandibular gland. Surgery on the sialolith was subsequently completed under general anesthesia extraorally. A brownish stone was present in the parenchyma of the submandibular gland, measuring 14×10 mm. PMID:25009613

  16. New star on the stage: amount of ray parenchyma in tree rings shows a link to climate.

    PubMed

    Olano, José Miguel; Arzac, Alberto; García-Cervigón, Ana I; von Arx, Georg; Rozas, Vicente

    2013-04-01

    Tree-ring anatomy reflects the year-by-year impact of environmental factors on tree growth. Up to now, research in this field has mainly focused on the hydraulic architecture, with ray parenchyma neglected despite the growing recognition of its relevance for xylem function. Our aim was to address this gap by exploring the potential of the annual patterns of xylem parenchyma as a climate proxy. We constructed ring-width and ray-parenchyma chronologies from 1965 to 2004 for 20 Juniperus thurifera trees growing in a Mediterranean continental climate. Chronologies were related to climate records by means of correlation, multiple regression and partial correlation analyses. Ray parenchyma responded to climatic conditions at critical stages during the xylogenetic process; namely, at the end of the previous year's xylogenesis (October) and at the onset of earlywood (May) and latewood formation (August). Ray parenchyma-based chronologies have potential to complement ring-width chronologies as a tool for climate reconstructions. Furthermore, medium- and low-frequency signals in the variation of ray parenchyma may improve our understanding of how trees respond to environmental fluctuations and to global change.

  17. [Effects of cadmium on the ovarian parenchyma in Swiss albino mice].

    PubMed

    Lubo-Palma, Adonías; Nava-Leal, Carmen; Villasmil, Víctor; Quevedo, Ana Luisa; Montiel, Maria; Simoes, David; Faría, Clarisa

    2006-09-01

    The aim of this work was to evaluate the effects of cadmium on the ovarian parenchyma. An experimental study was designed with 25 Swiss albino mice (healthy females) living 50 days under controlled laboratory conditions. For the experimental group, 21 mice were selected at random and divided into 3 groups (B, C, and D) of 7 animals each; thereafter they were exposed, respectively, to 50, 100 and 150 ppm of cadmium chloride dissolved in water offered ad libitum. They were compared with the control group A (6 remaining mice). Beginning on week three, physical and behavioral changes were observed: darkening of the eyes, yellowish discoloration of hair, flaccid and hypotonic muscles, irritability, aggressiveness and indifference. Ovaric histological findings were compared among the groups through optic microscopy and they were the following in cadmium exposed mice: 1) in the epithelium, proliferation, finger-like projections, hyperplasia, degeneration and necrosis; 2) in the ovary cortex, increased numbers of atresic follicles, decreased number of follicles in different stages of maturation, disorganization, edema and decreased number of yellow bodies; 3) in the interfollicular zone, areas of disorganization, edema and necrosis, mainly in the samples belonging to group D; 4) in the ovaric medulla, congestion, hyperemia and large sanguineous vasodilatation tending to haemorrhage. Since these effects increased with increasing concentrations of cadmium chloride, we may conclude that cadmium chloride is a highly toxic agent on the ovaric parenchyma of Swiss albino mice.

  18. The diagnostic value of EMA expression in the renal parenchyma tumors.

    PubMed

    Alexa, Aurora; Baderca, Flavia; Lighezan, Rodica; Zăhoi, Delia Elena; Izvernariu, D

    2011-01-01

    Renal parenchyma tumors are a heterogeneous group of malignancies that are difficult to diagnose and classify. Immunohistochemistry begun to be routinely used for the diagnosis of these tumors. Panels of antibodies are developed for the diagnostic assessment of these tumors, which include cytokeratins, epithelial membrane antigen and vimentin. Epithelial membrane antigen (EMA) is expressed by most of the tumor cell types. Forty-seven specimens of renal parenchyma tumors were studied immunohistochemically for the expression of EMA. In the majority of the cases, clear cells carcinoma was positive for EMA (25/33, 75.70%). All of the papillary carcinomas were positive, with different staining patterns between the two subtypes. The two cases of chromophobe cells carcinomas were intensely positive with a granular cytoplasmic staining pattern. The mixed epithelial-stromal tumor was negative for EMA in both of the components. Out of the three cases of sarcomatoid carcinomas, one was negative, one was weakly positive (+1) and the last was positive (+2). Intensely positive normal tubes were caught by the tumor proliferation in the negative case and in the negative stained areas of the weakly positive case.

  19. Biomechanics of the lung parenchyma: critical roles of collagen and mechanical forces.

    PubMed

    Suki, Béla; Ito, Satoru; Stamenovic, Dimitrije; Lutchen, Kenneth R; Ingenito, Edward P

    2005-05-01

    The biomechanical properties of connective tissues play fundamental roles in how mechanical interactions of the body with its environment produce physical forces at the cellular level. It is now recognized that mechanical interactions between cells and the extracellular matrix (ECM) have major regulatory effects on cellular physiology and cell-cycle kinetics that can lead to the reorganization and remodeling of the ECM. The connective tissues are composed of cells and the ECM, which includes water and a variety of biological macromolecules. The macromolecules that are most important in determining the mechanical properties of these tissues are collagen, elastin, and proteoglycans. Among these macromolecules, the most abundant and perhaps most critical for structural integrity is collagen. In this review, we examine how mechanical forces affect the physiological functioning of the lung parenchyma, with special emphasis on the role of collagen. First, we overview the composition of the connective tissue of the lung and their complex structural organization. We then describe how mechanical properties of the parenchyma arise from its composition as well as from the architectural organization of the connective tissue. We argue that, because collagen is the most important load-bearing component of the parenchymal connective tissue, it is also critical in determining the homeostasis and cellular responses to injury. Finally, we overview the interactions between the parenchymal collagen network and cellular remodeling and speculate how mechanotransduction might contribute to disease propagation and the development of small- and large-scale heterogeneities with implications to impaired lung function in emphysema.

  20. Coupled heterocellular arrays in the brain.

    PubMed

    Fróes, M M; Menezes, J R L

    2002-11-01

    Gap junctions are transcellular pathways that enable a dynamic metabolic coupling and a selective exchange of biological signaling mediators. Throughout the course of the brain development these intercellular channels are assembled into regionally and temporally defined patterns. The present review summarizes the possibilities of heterocellular gap junctional pairing in the brain parenchyma, involving glial cells, neurons and neural precursors as well as it highlights on the meaningfulness of these coupled arrays to the concept of brain functional compartments.

  1. Compositional analysis of Chinese water chestnut (Eleocharis dulcis) cell-wall material from parenchyma, epidermis, and subepidermal tissues.

    PubMed

    Grassby, Terri; Jay, Andrew J; Merali, Zara; Parker, Mary L; Parr, Adrian J; Faulds, Craig B; Waldron, Keith W

    2013-10-09

    Chinese water chestnut (Eleocharis dulcis (Burman f.) Trin ex Henschel) is a corm consumed globally in Oriental-style cuisine. The corm consists of three main tissues, the epidermis, subepidermis, and parenchyma; the cell walls of which were analyzed for sugar, phenolic, and lignin content. Sugar content, measured by gas chromatography, was higher in the parenchyma cell walls (931 μg/mg) than in the subepidermis (775 μg/mg) or epidermis (685 μg/mg). The alkali-extractable phenolic content, measured by high-performance liquid chromatography, was greater in the epidermal (32.4 μg/mg) and subepidermal cell walls (21.7 μg/mg) than in the cell walls of the parenchyma (12.3 μg/mg). The proportion of diferulic acids was higher in the parenchyma. The Klason lignin content of epidermal and subepidermal cell walls was ~15%. Methylation analysis of Chinese water chestnut cell-wall polysaccharides identified xyloglucan as the predominant hemicellulose in the parenchyma for the first time, and also a significant pectin component, similar to other nongraminaceous monocots.

  2. The lung strip: evaluation of a method to study contractility of pulmonary parenchyma.

    PubMed

    Evans, J N; Adler, K B

    1981-08-01

    Isolated strips of rabbit lung were examined as an in vitro model for assessment of the direct effect of pharmacologic agents on the pulmonary parenchyma. Changes in force of the strip were measured with an isometric force transducer. Histamine, acetylcholine and epinephrine elicited dose-related contractile responses. Morphological and immunohistochemical examination revealed three possible sources of force generation within the strip: airway smooth muscle, vascular smooth muscle, and interstitial actin-containing cells. Generation of force by the strip could reflect contraction of any combination of these three elements. Therefore, ascription of such contraction to peripheral airway smooth muscle alone is questionable. In order to assess the properties of the contractile elements within the strip, it is necessary to isolate and study them individually.

  3. Larch (Larix kaempferi) xylem parenchyma cells respond to subfreezing temperature by deep supercooling.

    PubMed

    Kasuga, Jun; Takata, Naoki; Yamane, Kenichi; Kuroda, Katsushi; Arakawa, Keita; Fujikawa, Seizo

    2007-01-01

    In previous studies, xylem parenchyma cells (XPCs) in the boreal softwood species larch, which has thick and rigid walls similar to those of XPCs in boreal hardwood species, were shown to respond to subfreezing temperature by deep supercooling during summer but change their freezing behavior to extracellular freezing during winter. In this study, we re-examined freezing behavior of XPCs in larch by observation of deep etching of frozen samples as well as observation of re-warmed samples after freezing using a cryo-scanning electron microscope. The results showed that XPCs in larch adapts to subfreezing temperature by deep supercooling throughout all seasons. Such freezing behavior is the same as that of XPCs in boreal hardwood species.

  4. Material characterization of liver parenchyma using specimen-specific finite element models.

    PubMed

    Untaroiu, Costin D; Lu, Yuan-Chiao

    2013-10-01

    The liver is one of the most frequently injured abdominal organs during motor vehicle crashes. Realistic car crash simulations require incorporating strain-rate dependent mechanical properties of soft tissue in finite element (FE) material models. This study presents a total of 30 tension tests performed on fresh bovine liver parenchyma at various loading rates in order to characterize the biomechanical and failure properties of liver parenchyma. Each specimen, cut in a standard dog-bone shape, was tested until failure at one of three loading rates (0.01 s(-1), 0.1s(-1), 1 s(-1)) using a tensile testing setup. Load and acceleration recorded from each specimen grip were employed to calculate the time history of force at specimen ends. The shapes of all specimens were reconstructed from laser scans recorded prior to each test and then used to develop specimen-specific FE models. A first-order Ogden material model and the time histories of specimen end displacement were assigned to each specimen FE model. The failure Green-Lagrangian strain showed averages around 50% and no significant dependence on loading rates, but the failure 2nd Piola-Kirchhoff stress showed rate-dependence with average values ranging from 33 kPa to 94 kPa. The FE models with material model parameters identified using a simulation-based optimization replicated well the time history of load recorded during the test. The FE simulations with model parameters identified using an analytical approach or based on the displacement of optical markers showed a significantly stiffer response and lower failure stress/strain than the FE specimen-specific models. This study provides novel biomechanical and failure data which can be easily implemented in FE models and used to assess injury risk in automobile collisions.

  5. Vascular defense responses in rice: peroxidase accumulation in xylem parenchyma cells and xylem wall thickening

    NASA Technical Reports Server (NTRS)

    Hilaire, E.; Young, S. A.; Willard, L. H.; McGee, J. D.; Sweat, T.; Chittoor, J. M.; Guikema, J. A.; Leach, J. E.

    2001-01-01

    The rice bacterial blight pathogen Xanthomonas oryzae pv. oryzae is a vascular pathogen that elicits a defensive response through interaction with metabolically active rice cells. In leaves of 12-day-old rice seedlings, the exposed pit membrane separating the xylem lumen from the associated parenchyma cells allows contact with bacterial cells. During resistant responses, the xylem secondary walls thicken within 48 h and the pit diameter decreases, effectively reducing the area of pit membrane exposed for access by bacteria. In susceptible interactions and mock-inoculated controls, the xylem walls do not thicken within 48 h. Xylem secondary wall thickening is developmental and, in untreated 65-day-old rice plants, the size of the pit also is reduced. Activity and accumulation of a secreted cationic peroxidase, PO-C1, were previously shown to increase in xylem vessel walls and lumen. Peptide-specific antibodies and immunogold-labeling were used to demonstrate that PO-C1 is produced in the xylem parenchyma and secreted to the xylem lumen and walls. The timing of the accumulation is consistent with vessel secondary wall thickening. The PO-C1 gene is distinct but shares a high level of similarity with previously cloned pathogen-induced peroxidases in rice. PO-C1 gene expression was induced as early as 12 h during resistant interactions and peaked between 18 and 24 h after inoculation. Expression during susceptible interactions was lower than that observed in resistant interactions and was undetectable after infiltration with water, after mechanical wounding, or in mature leaves. These data are consistent with a role for vessel secondary wall thickening and peroxidase PO-C1 accumulation in the defense response in rice to X. oryzae pv. oryzae.

  6. Gene expression associated with increased supercooling capability in xylem parenchyma cells of larch (Larix kaempferi).

    PubMed

    Takata, Naoki; Kasuga, Jun; Takezawa, Daisuke; Arakawa, Keita; Fujikawa, Seizo

    2007-01-01

    Xylem parenchyma cells (XPCs) in larch adapt to subfreezing temperatures by deep supercooling, while cortical parenchyma cells (CPCs) undergo extracellular freezing. The temperature limits of supercooling in XPCs changed seasonally from -30 degrees C during summer to -60 degrees C during winter as measured by freezing resistance. Artificial deacclimation of larch twigs collected in winter reduced the supercooling capability from -60 degrees C to -30 degrees C. As an approach to clarify the mechanisms underlying the change in supercooling capability of larch XPCs, genes expressed in association with increased supercooling capability were examined. By differential screening and differential display analysis, 30 genes were found to be expressed in association with increased supercooling capability in XPCs. These 30 genes were categorized into several groups according to their functions: signal transduction factors, metabolic enzymes, late embryogenesis abundant proteins, heat shock proteins, protein synthesis and chromatin constructed proteins, defence response proteins, membrane transporters, metal-binding proteins, and functionally unknown proteins. All of these genes were expressed most abundantly during winter, and their expression was reduced or disappeared during summer. The expression of all of the genes was significantly reduced or disappeared with deacclimation of winter twigs. Interestingly, all but one of the genes were expressed more abundantly in the xylem than in the cortex. Eleven of the 30 genes were thought to be novel cold-induced genes. The results suggest that change in the supercooling capability of XPCs is associated with expression of genes, including genes whose functions have not been identified, and also indicate that gene products that have been thought to play a role in dehydration tolerance by extracellular freezing also have a function by deep supercooling.

  7. Analysis of radiation therapy in a model of triple-negative breast cancer brain metastasis.

    PubMed

    Smart, DeeDee; Garcia-Glaessner, Alejandra; Palmieri, Diane; Wong-Goodrich, Sarah J; Kramp, Tamalee; Gril, Brunilde; Shukla, Sudhanshu; Lyle, Tiffany; Hua, Emily; Cameron, Heather A; Camphausen, Kevin; Steeg, Patricia S

    2015-10-01

    Most cancer patients with brain metastases are treated with radiation therapy, yet this modality has not yet been meaningfully incorporated into preclinical experimental brain metastasis models. We applied two forms of whole brain radiation therapy (WBRT) to the brain-tropic 231-BR experimental brain metastasis model of triple-negative breast cancer. When compared to sham controls, WBRT as 3 Gy × 10 fractions (3 × 10) reduced the number of micrometastases and large metastases by 87.7 and 54.5 %, respectively (both p < 0.01); whereas a single radiation dose of 15 Gy × 1 (15 × 1) was less effective, reducing metastases by 58.4 % (p < 0.01) and 47.1 % (p = 0.41), respectively. Neuroinflammation in the adjacent brain parenchyma was due solely to a reaction from metastases, and not radiotherapy, while adult neurogenesis in brains was adversely affected following both radiation regimens. The nature of radiation resistance was investigated by ex vivo culture of tumor cells that survived initial WBRT ("Surviving" cultures). The Surviving cultures surprisingly demonstrated increased radiosensitivity ex vivo. In contrast, re-injection of Surviving cultures and re-treatment with a 3 × 10 WBRT regimen significantly reduced the number of large and micrometastases that developed in vivo, suggesting a role for the microenvironment. Micrometastases derived from tumor cells surviving initial 3 × 10 WBRT demonstrated a trend toward radioresistance upon repeat treatment (p = 0.09). The data confirm the potency of a fractionated 3 × 10 WBRT regimen and identify the brain microenvironment as a potential determinant of radiation efficacy. The data also nominate the Surviving cultures as a potential new translational model for radiotherapy.

  8. The role of the parenchyma sheath and PCD during the development of oil cavities in Pterodon pubescens (Leguminosae-Papilionoideae).

    PubMed

    Rodrigues, Tatiane Maria; Santos, Daniela Carvalho Dos; Machado, Silvia Rodrigues

    2011-07-01

    Pterodon pubescens cavities are constituted by lumen and uniseriated epithelium surrounded by multiseriate parenchyma sheath. We studied the development of secretory cavities, including the role of parenchyma sheath, using light and transmission electron microscopy. A Tunel assay was performed to verify whether programmed cell death (PCD) occurs during the process. The lumen is formed by schizogeny and lysigeny occur in later developmental stages of the secretory cavities. Ultrastructurally, epithelial cells in later developmental stages become dark and with sinuous walls; the protoplast becomes retracted and the cytoplasm shows low organelle definition. Degenerated cells are released toward the lumen. Our results showed that PCD occurs during later developmental stages of cavities and plays a critical role in functioning of these glands. New cells originated from the parenchyma sheath differentiate into secretory cells and replace those degenerated ones. This fact associated to PCD guarantees epithelium renovation during the secretory cycle and the maintenance of secretory activity of cavities.

  9. 46 CFR 148.445 - Adjacent spaces.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Adjacent spaces. 148.445 Section 148.445 Shipping COAST... THAT REQUIRE SPECIAL HANDLING Additional Special Requirements § 148.445 Adjacent spaces. When... following requirements must be met: (a) Each space adjacent to a cargo hold must be ventilated by...

  10. 46 CFR 148.445 - Adjacent spaces.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Adjacent spaces. 148.445 Section 148.445 Shipping COAST... THAT REQUIRE SPECIAL HANDLING Additional Special Requirements § 148.445 Adjacent spaces. When... following requirements must be met: (a) Each space adjacent to a cargo hold must be ventilated by...

  11. 46 CFR 148.445 - Adjacent spaces.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Adjacent spaces. 148.445 Section 148.445 Shipping COAST... THAT REQUIRE SPECIAL HANDLING Additional Special Requirements § 148.445 Adjacent spaces. When... following requirements must be met: (a) Each space adjacent to a cargo hold must be ventilated by...

  12. 46 CFR 148.445 - Adjacent spaces.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Adjacent spaces. 148.445 Section 148.445 Shipping COAST... THAT REQUIRE SPECIAL HANDLING Additional Special Requirements § 148.445 Adjacent spaces. When... following requirements must be met: (a) Each space adjacent to a cargo hold must be ventilated by...

  13. Texture-learning-based system for three-dimensional segmentation of renal parenchyma in abdominal CT images

    NASA Astrophysics Data System (ADS)

    Peng, Cong-Qi; Chang, Yuan-Hsiang; Wang, Li-Jen; Wong, Yon-Choeng; Chiang, Yang-Jen; Jiang, Yan-Yau

    2009-02-01

    Abdominal CT images are commonly used for the diagnosis of kidney diseases. With the advances of CT technology, processing of CT images has become a challenging task mainly because of the large number of CT images being studied. This paper presents a texture-learning based system for the three-dimensional (3D) segmentation of renal parenchyma in abdominal CT images. The system is designed to automatically delineate renal parenchyma and is based on the texturelearning and the region-homogeneity-based approaches. The first approach is achieved with the texture analysis using the gray-level co-occurrence matrix (GLCM) features and an artificial neural network (ANN) to determine if a pixel in the CT image is likely to fall within the renal parenchyma. The second approach incorporates a two-dimensional (2D) region growing to segment renal parenchyma in single CT image slice and a 3D region growing to propagate the segmentation results to neighboring CT image slices. The criterion for the region growing is a test of region-homogeneity which is defined by examining the ANN outputs. In system evaluation, 10 abdominal CT image sets were used. Automatic segmentation results were compared with manually segmentation results using the Dice similarity coefficient. Among the 10 CT image sets, our system has achieved an average Dice similarity coefficient of 0.87 that clearly shows a high correlation between the two segmentation results. Ultimately, our system could be incorporated in applications for the delineation of renal parenchyma or as a preprocessing in a CAD system of kidney diseases.

  14. Celery (Apium graveolens) parenchyma cell walls: cell walls with minimal xyloglucan.

    PubMed

    Thimm, Julian C.; Burritt, David J.; Sims, Ian M.; Newman, Roger H.; Ducker, William A.; Melton, Laurence D.

    2002-10-01

    The primary walls of celery (Apium graveolens L.) parenchyma cells were isolated and their polysaccharide components characterized by glycosyl linkage analysis, cross-polarization magic-angle spinning solid-state 13C nuclear magnetic resonance (CP/MAS 13C NMR) and X-ray diffraction. Glycosyl linkage analysis showed that the cell walls consisted of mainly cellulose (43 mol%) and pectic polysaccharides (51 mol%), comprising rhamnogalacturonan (28 mol%), arabinan (12 mol%) and galactan (11 mol%). The amounts of xyloglucan (2 mol%) and xylan (2 mol%) detected in the cell walls were strikingly low. The small amount of xyloglucan present means that it cannot coat the cellulose microfibrils. Solid-state 13C NMR signals were consistent with the constituents identified by glycosyl linkage analysis and allowed the walls to be divided into three domains, based on the rigidity of the polymers. Cellulose (rigid) and rhamnogalacturonan (semi-mobile) polymers responded to the CP/MAS 13C NMR pulse sequence and were distinguished by differences in proton spin relaxation time constants. The arabinans, the most mobile polymers, responded to single-pulse excitation (SPE), but not CP/MAS 13C NMR. From solid-state 13C NMR of the cell walls the diameter of the crystalline cellulose microfibrils was determined to be approximately 3 nm while X-ray diffraction of the cell walls gave a value for the diameter of approximately 2 nm.

  15. Efficient ethanol production from separated parenchyma and vascular bundle of oil palm trunk.

    PubMed

    Prawitwong, Panida; Kosugi, Akihiko; Arai, Takamitsu; Deng, Lan; Lee, Kok Chang; Ibrahim, Darah; Murata, Yoshinori; Sulaiman, Othman; Hashim, Rokiah; Sudesh, Kumar; Ibrahim, Wan Asma Bt; Saito, Masayoshi; Mori, Yutaka

    2012-12-01

    For efficient utilization of both starchy and cellulosic materials, oil palm trunk was separated into parenchyma (PA) and vascular bundle (VB). High solid-state simultaneous saccharification and fermentation (HSS-SSF) using 30% (w/v) PA, containing 46.7% (w/w) starch, supplemented with amylases and Saccharomyces cerevisiae K3, produced 6.1% (w/v) ethanol. Subsequent alkali-pretreatment using sodium hydroxide was carried out with starch-free PA (sfPA) and VB. Enzymatic digestibility of 5% (w/v) pretreated sfPA and VB was 92% and 97%, respectively, using 18 FPU of commercial cellulase supplemented with 10 U of Novozyme-188 per gram of substrate. Likewise, HSS-SSF using 30% (w/v) alkali-pretreated sfPA and VB, with cellulases and yeast, resulted in high ethanol production (8.2% and 8.5% (w/v), respectively). These results show that HSS-SSF using separated PA and VB is a useful fermentation strategy, without loss of starchy and cellulosic materials, for oil palm trunk.

  16. Biochemical and Cytological Analyses of RNA Synthesis in Kinetin-treated Pea Root Parenchyma 1

    PubMed Central

    Shininger, Terry L.

    1980-01-01

    Excised cortical parenchyma from the pea root (cv. Little Marvel) responds to kinetin/auxin treatment with an increased rate of RNA synthesis well before reinitiating DNA synthesis. Few cells synthesize RNA in the 1st hour of culture. In the presence of kinetin/auxin, the nuclear labeling index increases 2.5-fold as compared to control cultures. The RNA synthesis response has an apparent lag period of 2-4 hours as shown by double label ([3H]adenosine/[14C]adenosine) experiments. Qualitatively, the RNA synthesized at 4-6 hours sediments between 18S and 5S. The RNA synthesized at 14-16 hours and 24-26 hours is primarily ribosomal RNA when kinetin is present. In the absence of kinetin, no clear pattern of RNA synthesis emerges. The data are interpreted to mean that kinetin treatment elicits RNA synthesis in a small proportion of the population initially and this may involve messenger-like RNA. Later, more cells synthesize RNA and this is primarily rRNA. Images PMID:16661292

  17. Neutrophils Infiltrate the Spinal Cord Parenchyma of Rats with Experimental Diabetic Neuropathy

    PubMed Central

    Newton, Victoria L.; Guck, Jonathan D.; Cotter, Mary A.

    2017-01-01

    Spinal glial cell activation and cytokine secretion have been implicated in the etiology of neuropathic pain in a number of experimental models, including diabetic neuropathy. In this study, streptozotocin- (STZ-) induced diabetic rats were either untreated or treated with gabapentin (50 mg/kg/day by gavage for 2 weeks, from 6 weeks after STZ). At 8 weeks after STZ, hypersensitivity was confirmed in the untreated diabetic rats as a reduced response threshold to touch, whilst mechanical thresholds in gabapentin-treated diabetic rats were no different from controls. Diabetes-associated thermal hypersensitivity was also ameliorated by gabapentin. We performed a cytokine profiling array in lumbar spinal cord samples from control and diabetic rats. This revealed an increase in L-selectin, an adhesion molecule important for neutrophil transmigration, in the spinal cord of diabetic rats but not diabetic rats treated with gabapentin. Furthermore, we found an increase in the number of neutrophils present in the parenchyma of the spinal cord, which was again ameliorated in gabapentin-treated diabetic rats. Therefore, we suggest that dysregulated spinal L-selectin and neutrophil infiltration into the spinal cord could contribute to the pathogenesis of painful diabetic neuropathy. PMID:28293643

  18. Resistance to alveolar shape change limits range of force propagation in lung parenchyma.

    PubMed

    Ma, Baoshun; Smith, Bradford J; Bates, Jason H T

    2015-06-01

    We have recently shown that if the lung parenchyma is modeled in 2 dimensions as a network of springs arranged in a pattern of repeating hexagonal cells, the distortional forces around a contracting airway propagate much further from the airway wall than classic continuum theory predicts. In the present study we tested the hypothesis that this occurs because of the negligible shear modulus of a hexagonal spring network. We simulated the narrowing of an airway embedded in a hexagonal network of elastic alveolar walls when the hexagonal cells of the network offered some resistance to a change in shape. We found that as the forces resisting shape change approach about 10% of the forces resisting length change of an individual spring the range of distortional force propagation in the spring network fell of rapidly as in an elastic continuum. We repeated these investigations in a 3-dimensional spring network composed of space-filling polyhedral cells and found similar results. This suggests that force propagation away from a point of local parenchymal distortion also falls off rapidly in real lung tissue.

  19. Revisiting nanoparticle technology for blood-brain barrier transport: Unfolding at the endothelial gate improves the fate of transferrin receptor-targeted liposomes.

    PubMed

    Johnsen, Kasper Bendix; Moos, Torben

    2016-01-28

    An unmet need exists for therapeutic compounds to traverse the brain capillary endothelial cells that denote the blood-brain barrier (BBB) to deliver effective treatment to the diseased brain. The use of nanoparticle technology for targeted delivery to the brain implies that targeted liposomes encapsulating a drug of interest will undergo receptor-mediated uptake and transport through the BBB with a subsequent unfolding of the liposomal content inside the brain, hence revealing drug release to adjacent drug-demanding neurons. As transferrin receptors (TfRs) are present on brain capillary endothelial, but not on endothelial cells elsewhere in the body, the use of TfR-targeted liposomes - colloidal particulates with a phospholipid bilayer membrane - remains the most relevant strategy to obtain efficient drug delivery to the brain. However, many studies have failed to provide sufficient quantitative data to proof passage of the BBB and significant appearance of drugs inside the brain parenchyma. Here, we critically evaluate the current evidence on the use of TfR-targeted liposomes for brain drug delivery based on a thorough investigation of all available studies within this research field. We focus on issues with respect to experimental design and data analysis that may provide an explanation to conflicting reports, and we discuss possible explanations for the current lack of sufficient transcytosis across the BBB for implementation in the design of TfR-targeted liposomes. We finally provide a list of suggestions for strategies to obtain substantial uptake and transport of drug carriers at the BBB with a concomitant transport of therapeutics into the brain.

  20. Bradykinin enhances invasion of malignant glioma into the brain parenchyma by inducing cells to undergo amoeboid migration

    PubMed Central

    Seifert, Stefanie; Sontheimer, Harald

    2014-01-01

    Abstract The molecular and cellular mechanisms governing cell motility and directed migration in response to the neuropeptide bradykinin are largely unknown. Here, we demonstrate that human glioma cells whose migration is guided by bradykinin generate bleb-like protrusions. We found that activation of the B2 receptor leads to a rise in free Ca2+ from internal stores that activates actomyosin contraction and subsequent cytoplasmic flow into protrusions forming membrane blebs. Furthermore Ca2+ activates Ca2+-dependent K+ and Cl− channels, which participate in bleb regulation. Treatment of gliomas with bradykinin in situ increased glioma growth by increasing the speed of cell migration at the periphery of the tumour mass. To test if bleb formation is related to bradykinin-promoted glioma invasion we blocked glioma migration with blebbistatin, a blocker of myosin kinase II, which is necessary for proper bleb retraction. Our findings suggest a pivotal role of bradykinin during glioma invasion by stimulating amoeboid migration of glioma cells. PMID:25194042

  1. Acoustic radiation force impulse imaging for evaluation of renal parenchyma elasticity in diabetic nephropathy.

    PubMed

    Goya, Cemil; Kilinc, Faruk; Hamidi, Cihad; Yavuz, Alpaslan; Yildirim, Yasar; Cetincakmak, Mehmet Guli; Hattapoglu, Salih

    2015-02-01

    OBJECTIVE. The goal of this study is to evaluate the changes in the elasticity of the renal parenchyma in diabetic nephropathy using acoustic radiation force impulse imaging. SUBJECTS AND METHODS. The study included 281 healthy volunteers and 114 patients with diabetic nephropathy. In healthy volunteers, the kidney elasticity was assessed quantitatively by measuring the shear-wave velocity using acoustic radiation force impulse imaging based on age, body mass index, and sex. The changes in the renal elasticity were compared between the different stages of diabetic nephropathy and the healthy control group. RESULTS. In healthy volunteers, there was a statistically significant correlation between the shear-wave velocity values and age and sex. The shear-wave velocity values for the kidneys were 2.87, 3.14, 2.95, 2.68, and 2.55 m/s in patients with stage 1, 2, 3, 4, and 5 diabetic nephropathy, respectively, compared with 2.35 m/s for healthy control subjects. Acoustic radiation force impulse imaging was able to distinguish between the different diabetic nephropathy stages (except for stage 5) in the kidneys. The threshold value for predicting diabetic nephropathy was 2.43 m/s (sensitivity, 84.1%; specificity, 67.3%; positive predictive value, 93.1%; negative predictive value 50.8%; accuracy, 72.1%; positive likelihood ratio, 2.5; and negative likelihood ratio, 0.23). CONCLUSION. Acoustic radiation force impulse imaging could be used for the evaluation of the renal elasticity changes that are due to secondary structural and functional changes in diabetic nephropathy.

  2. Thermodynamic Battle for Photosynthate Acquisition between Sieve Tubes and Adjoining Parenchyma in Transport Phloem1

    PubMed Central

    Hafke, Jens B.; van Amerongen, Jan-Kees; Kelling, Frits; Furch, Alexandra C.U.; Gaupels, Frank; van Bel, Aart J.E.

    2005-01-01

    In transport phloem, photoassimilates escaping from the sieve tubes are released into the apoplasmic space between sieve element (SE)/companion cell (CC) complexes (SE/CCs) and phloem parenchyma cells (PPCs). For uptake respective retrieval, PPCs and SE/CCs make use of plasma membrane translocators energized by the proton motive force (PMF). Their mutual competitiveness, which essentially determines the amount of photoassimilates translocated through the sieve tubes, therefore depends on the respective PMFs. We measured the components of the PMF, membrane potential and ΔpH, of SE/CCs and PPCs in transport phloem. Membrane potentials of SE/CCs and PPCs in tissue slices as well as in intact plants fell into two categories. In the first group including apoplasmically phloem-loading species (e.g. Vicia, Solanum), the membrane potentials of the SEs are more negative than those of the PPCs. In the second group including symplasmically phloem-loading species (e.g. Cucurbita, Ocimum), membrane potentials of SEs are equal to or slightly more positive than those of PPCs. Pure sieve tube sap collected from cut aphid stylets was measured with H+-selective microelectrodes. Under our experimental conditions, pH of the sieve tube saps was around 7.5, which is comparable to the pH of cytoplasmic compartments in parenchymatous cells. In conclusion, only the membrane potential appears to be relevant for the PMF-determined competition between SE/CCs and PPCs. The findings may imply that the axial sinks along the pathway withdraw more photoassimilates from the sieve tubes in symplasmically loading species than in apoplasmically loading species. PMID:15980202

  3. Ultrastructure of Fibre and Parenchyma Cell Walls During Early Stages of Culm Development in Dendrocalamus asper

    PubMed Central

    GRITSCH, CRISTINA SANCHIS; MURPHY, RICHARD J.

    2005-01-01

    • Background and Aims The anatomy of bamboo culms and the multilayered structure of fibre cell walls are known to be the main determinant factors for its physical and mechanical properties. Studies on the bamboo cell wall have focussed mainly on fully elongated and mature fibres. The main aim of this study was to describe the ultrastructure of primary and secondary cell walls in culm tissues of Dendrocalamus asper at different stages of development. • Methods The development of fibre and parenchyma tissues was classified into four stages based on light microscopy observations made in tissues from juvenile plants. The stages were used as a basis for transmission electron microscopy study on the ultrastructure of the cell wall during the process of primary and early secondary cell wall formation. Macerations and phloroglucinol–HCl staining were employed to investigate fibre cell elongation and fibre cell wall lignification, respectively. • Key Results The observations indicated that the primary wall is formed by the deposition of two distinct layers during the elongation of the internode and that secondary wall synthesis may begin before the complete cessation of internode and fibre elongation. Elongation was followed by a maturation phase characterized by the deposition of multiple secondary wall layers, which varied in number according to the cell type, location in the culm tissue and stage of shoot development. Lignification of fibre cell walls started at the period prior to the cessation of internode elongation. • Conclusions The structure of the primary cell wall was comprised of two layers. The fibre secondary cell wall began to be laid down while the cells were still undergoing some elongation, suggesting that it may act to cause the slow-down and eventual cessation of cell elongation. PMID:15665037

  4. 43 CFR 420.3 - Adjacent lands.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 43 Public Lands: Interior 1 2014-10-01 2014-10-01 false Adjacent lands. 420.3 Section 420.3 Public Lands: Interior Regulations Relating to Public Lands BUREAU OF RECLAMATION, DEPARTMENT OF THE INTERIOR OFF-ROAD VEHICLE USE § 420.3 Adjacent lands. When administratively feasible, the regulation of...

  5. 43 CFR 420.3 - Adjacent lands.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 43 Public Lands: Interior 1 2012-10-01 2011-10-01 true Adjacent lands. 420.3 Section 420.3 Public Lands: Interior Regulations Relating to Public Lands BUREAU OF RECLAMATION, DEPARTMENT OF THE INTERIOR OFF-ROAD VEHICLE USE § 420.3 Adjacent lands. When administratively feasible, the regulation of...

  6. 43 CFR 420.3 - Adjacent lands.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 43 Public Lands: Interior 1 2013-10-01 2013-10-01 false Adjacent lands. 420.3 Section 420.3 Public Lands: Interior Regulations Relating to Public Lands BUREAU OF RECLAMATION, DEPARTMENT OF THE INTERIOR OFF-ROAD VEHICLE USE § 420.3 Adjacent lands. When administratively feasible, the regulation of...

  7. 43 CFR 420.3 - Adjacent lands.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Adjacent lands. 420.3 Section 420.3 Public Lands: Interior Regulations Relating to Public Lands BUREAU OF RECLAMATION, DEPARTMENT OF THE INTERIOR OFF-ROAD VEHICLE USE § 420.3 Adjacent lands. When administratively feasible, the regulation of...

  8. 43 CFR 420.3 - Adjacent lands.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 1 2011-10-01 2011-10-01 false Adjacent lands. 420.3 Section 420.3 Public Lands: Interior Regulations Relating to Public Lands BUREAU OF RECLAMATION, DEPARTMENT OF THE INTERIOR OFF-ROAD VEHICLE USE § 420.3 Adjacent lands. When administratively feasible, the regulation of...

  9. Celery (Apium graveolens L.) parenchyma cell walls examined by atomic force microscopy: effect of dehydration on cellulose microfibrils.

    PubMed

    Thimm, J C; Burritt, D J; Ducker, W A; Melton, L D

    2000-12-01

    Atomic force microscopy (AFM) was used to image celery (Apium graveolens L.) parenchyma cell walls in situ. Cellulose microfibrils could clearly be distinguished in topographic images of the cell wall. The microfibrils of the hydrated walls appeared smaller, more uniformly distributed, and less enmeshed than those of dried peels. In material that was kept hydrated at all times and imaged under water, the microfibril diameter was mainly in the range 6-25 nm. The cellulose microfibril diameters were highly dependent on the water content of the specimen. As the water content was decreased, by mixing ethanol with the bathing solution, the microfibril diameters increased. Upon complete dehydration of the specimen we observed a significant increase in microfibril diameter. The procedure used to dehydrate the parenchyma cells also influenced the size of cellulose microfibrils with freeze-dried material having larger diameters than air-dried material.

  10. Accidental aspiration of head scarf pin in left bronchus piercing the lung parenchyma: A rare case in a child

    PubMed Central

    Parvez, Yusuf; Kandath, Mohammed Ashraf

    2016-01-01

    Foreign body (FB) aspiration is commonly seen in children but less commonly in adolescents. Headscarf pin aspiration is common in Muslim girls, who inappropriately place the pins between their lips while securing the scarf on the head. Bronchoscopy is the treatment modality of choice, and surgery is rarely required. An 11-year-old girl was admitted as a case of accidental aspiration of headscarf pin. X-ray chest showed a radiopaque object in the left bronchus piercing the lung parenchyma. Computed tomography (CT) chest confirmed the diagnosis. The headscarf pin was removed by flexible bronchoscopy as the ear, nose, and throat (ENT) surgeon failed to remove it by rigid bronchoscopy. The FB was removed successfully and the patient was discharged home. Removal of a sharp pin by bronchoscopy is difficult, especially if it pierces the lung parenchyma. In our case, the pin was bent by forceps and then removed by a flexible bronchoscope, which requires a highly skilled professional. PMID:27578937

  11. Accidental aspiration of head scarf pin in left bronchus piercing the lung parenchyma: A rare case in a child.

    PubMed

    Parvez, Yusuf; Kandath, Mohammed Ashraf

    2016-01-01

    Foreign body (FB) aspiration is commonly seen in children but less commonly in adolescents. Headscarf pin aspiration is common in Muslim girls, who inappropriately place the pins between their lips while securing the scarf on the head. Bronchoscopy is the treatment modality of choice, and surgery is rarely required. An 11-year-old girl was admitted as a case of accidental aspiration of headscarf pin. X-ray chest showed a radiopaque object in the left bronchus piercing the lung parenchyma. Computed tomography (CT) chest confirmed the diagnosis. The headscarf pin was removed by flexible bronchoscopy as the ear, nose, and throat (ENT) surgeon failed to remove it by rigid bronchoscopy. The FB was removed successfully and the patient was discharged home. Removal of a sharp pin by bronchoscopy is difficult, especially if it pierces the lung parenchyma. In our case, the pin was bent by forceps and then removed by a flexible bronchoscope, which requires a highly skilled professional.

  12. Diffuse renal parenchyma uptake with bone scintigraphy in a patient with paroxysmal nocturnal hemoglobinuria and normal kidney function.

    PubMed

    Balink, Hans; Hoogendoorn, Mels; Hemmelder, Marc

    2014-03-01

    A 41-year-old woman with a Harrington spondylodesis presented with lower back pain. Bone scintigraphy showed diffusely increased parenchymal uptake in both kidneys. She reported 2 previous periods of dark, almost black, urine. Additional flow cytometric analysis confirmed the diagnosis of paroxysmal nocturnal hemoglobinuria. The increased renal parenchyma uptake is very probably due to paroxysmal nocturnal hemoglobinuria-related renal hemosiderosis. Remarkably, the patient did not develop any abnormality of renal function.

  13. Infarction and Laceration of Liver Parenchyma Caused by Wedged CO{sub 2} Venography Before TIPS Insertion

    SciTech Connect

    Theuerkauf, Ingo; Strunk, Holger; Brensing, Karl August; Schild, Hans Heinz; Pfeifer, Ulrich

    2001-01-15

    We describe the fatal outcome of an elective TIPS procedure performed in a 43-year-old man with alcoholic cirrhosis. Wedged hepatic venography with CO{sub 2} was the reason for infarction and laceration of liver parenchyma resulting in a subcapsular hematoma and subsequent intra-abdominal bleeding. This is the first report of this complication after the use of CO{sub 2} in a cirrhotic patient.

  14. Quantitative computed tomography of lung parenchyma in patients with emphysema: analysis of higher-density lung regions

    NASA Astrophysics Data System (ADS)

    Lederman, Dror; Leader, Joseph K.; Zheng, Bin; Sciurba, Frank C.; Tan, Jun; Gur, David

    2011-03-01

    Quantitative computed tomography (CT) has been widely used to detect and evaluate the presence (or absence) of emphysema applying the density masks at specific thresholds, e.g., -910 or -950 Hounsfield Unit (HU). However, it has also been observed that subjects with similar density-mask based emphysema scores could have varying lung function, possibly indicating differences of disease severity. To assess this possible discrepancy, we investigated whether density distribution of "viable" lung parenchyma regions with pixel values > -910 HU correlates with lung function. A dataset of 38 subjects, who underwent both pulmonary function testing and CT examinations in a COPD SCCOR study, was assembled. After the lung regions depicted on CT images were automatically segmented by a computerized scheme, we systematically divided the lung parenchyma into different density groups (bins) and computed a number of statistical features (i.e., mean, standard deviation (STD), skewness of the pixel value distributions) in these density bins. We then analyzed the correlations between each feature and lung function. The correlation between diffusion lung capacity (DLCO) and STD of pixel values in the bin of -910HU <= PV < -750HU was -0.43, as compared with a correlation of -0.49 obtained between the post-bronchodilator ratio (FEV1/FVC) measured by the forced expiratory volume in 1 second (FEV1) dividing the forced vital capacity (FVC) and the STD of pixel values in the bin of -1024HU <= PV < -910HU. The results showed an association between the distribution of pixel values in "viable" lung parenchyma and lung function, which indicates that similar to the conventional density mask method, the pixel value distribution features in "viable" lung parenchyma areas may also provide clinically useful information to improve assessments of lung disease severity as measured by lung functional tests.

  15. Dissection of the Process of Brain Metastasis Reveals Targets and Mechanisms for Molecular-based Intervention.

    PubMed

    Weidle, Ulrich H; Birzele, Fabian; Kollmorgen, Gwendlyn; Rüger, Rüdiger

    2016-01-01

    Brain metastases outnumber the incidence of brain tumors by a factor of ten. Patients with brain metastases have a dismal prognosis and current treatment modalities achieve only a modest clinical benefit. We discuss the process of brain metastasis with respect to mechanisms and involved targets to outline options for therapeutic intervention and focus on breast and lung cancer, as well as melanoma. We describe the process of penetration of the blood-brain-barrier (BBB) by disseminated tumor cells, establishment of a metastatic niche, colonization and outgrowth in the brain parenchyma. Furthermore, the role of angiogenesis in colonization of the brain parenchyma, interactions of extravasated tumor cells with microglia and astrocytes, as well as their propensity for neuromimicry, is discussed. We outline targets suitable for prevention of metastasis and summarize targets suitable for treatment of established brain metastases. Finally, we highlight the implications of findings revealing druggable mutations in brain metastases that cannot be identified in matching primary tumors.

  16. Fractal analysis of two-dimensional vascularity in primary prostate cancer and surrounding non-tumoral parenchyma.

    PubMed

    Taverna, Gianluigi; Colombo, Piergiuseppe; Grizzi, Fabio; Franceschini, Barbara; Ceva-Grimaldi, Giorgia; Seveso, Mauro; Giusti, Guido; Piccinelli, Alessandro; Graziotti, Pierpaolo

    2009-01-01

    Prostate cancer is the fifth most frequent cancer in the world. However, none of the actual prognostic factors provide a valid index for predicting patient outcome. Here, we evaluate the two-dimensional vascularity in primary prostate tumors and surrounding non-tumoral parenchyma by means of fractal geometry, and assess any correlations between the results and some clinical and pathological parameters of prostate carcinoma. Prostate sections from 27 carcinoma patients were treated with CD34 antibodies. Two >10mm(2) areas of tumoral and surrounding non-tumoral parenchyma were digitized using an image analysis system that automatically quantified the fractal dimension of the vascular surface. Data were correlated with patient's age, PSA level, clinical and pathological stage, Gleason score, tumor volume, vascular invasion, surgical margins, and biochemical relapse. Two groups of patients were distinguished on the basis of whether the fractal dimension of their tumoral vascular surface was higher (group 1) or lower (group 2) than that of the surrounding non-tumoral parenchyma. Statistically significant between-group differences were found in terms of serum PSA levels (p=0.0061), tumor volume (p=0.0017), and biochemical relapse (p=0.031). The patients in group 2 had a poorer outcome. Our findings suggest a group of prostate cancer patients with a poor outcome, and the vascular surface fractal dimension as a helpful geometrical index in clinical practice.

  17. Functional units in rainbow trout (Salmo gairdneri, Richardson) liver: III. Morphometric analysis of parenchyma, stroma, and component cell types.

    PubMed

    Hampton, J A; Lantz, R C; Hinton, D E

    1989-05-01

    Hepatic stroma and parenchyma with its component cell types were quantitatively described in adult male and female actively-spawning 5-year-old rainbow trout (Salmo gairdneri, Richardson). Point-count morphometry of glycol methacrylate sections estimated volume compartments for stroma and parenchyma. Veins composed 85% of the stroma while arteries and bile ducts occupied approximately 6-7% each. Parenchyma accounted for 95% of hepatic volume. Point-count morphometry of transmission electron micrographs estimated volume compartments as well as numerical and surface density measurements for parenchymal components. Within the hepatic parenchymal compartment, hepatocytes occupied 85% and showed significant sex differences. Female hepatocytes were significantly more numerous but were smaller, only 60% of the volume of male hepatocytes. Since hepatocyte nuclear volume was equal in both sexes, differences were due to reduced cytoplasmic volume in females. Perisinusoidal macrophages of females occupied larger volumes of their respective parenchymal compartments, and their larger mean cytoplasmic volumes suggested activation. Biliary epithelial cells of preductules and ductules were numerous. Ratios of numerical density of hepatocytes to biliary epithelial cells were consistent with a tubular arrangement of hepatocytes. Factors possibly mediating the sexual dimorphism are discussed.

  18. Isolation of rice dwarf mutants with ectopic deposition of phenolic components including lignin in parenchyma cell walls of internodes.

    PubMed

    Sato, Kanna; Kawamura, Asuka; Obara, Tsukasa; Kawai, Shinya; Kajita, Shinya; Kitano, Hidemi; Katayama, Yoshihiro

    2011-12-01

    Rice internodes must have the proper shape to support high-yielding panicles. The shape of internodes is controlled by various factors involved in their formation, such as developmental patterns, cell division, cell elongation, and cell wall biosynthesis. To understand the regulation of internode development, we screened dwarf mutants to identify those with a phenotype of ectopic deposits of phenolic components in parenchyma cell walls of internodes. We named these mutants ectopic deposition of phenolic components1 (edp1). Two alleles were identified, edp1-1 and edp1-2. Furthermore, these mutants showed disordered cell files in internode parenchyma. These abnormal phenotypes were very similar to that of a previously reported dwarf50 (d50) mutant. Genetic analyses of edp1 mutants revealed that the edp1 loci are distinct from d50. Our results indicate that analyses of edp1 mutants as well as the d50 mutant will be useful for understanding the molecular mechanisms behind ectopic deposition of cell wall phenolic components in internode parenchyma cells and the regulation of internode development.

  19. Acoustic Radiation Force Impulse Imaging for Noninvasive Evaluation of Renal Parenchyma Elasticity: Preliminary Findings

    PubMed Central

    Xu, Hui-Xiong; Peng, Ai; Zhang, Yi-Feng; Liu, Lin-Na

    2013-01-01

    Objective To evaluate the diagnostic value of acoustic radiation force impulse (ARFI) to test the elasticity of renal parenchyma by measuring the shear wave velocity (SWV) which might be used to detect chronic kidney disease (CKD). Methods 327 healthy volunteers and 64 CKD patients were enrolled in the study. The potential influencing factors and measurement reproducibility were evaluated in the healthy volunteers. Correlations between SWV and laboratory tests were analyzed in CKD patients.?Receiver-operating characteristic curve (ROC) analyses were performed to assess the diagnostic performance of ARFI. Results The SWV of healthy volunteers correlated significantly to age (r = −0.22, P<0.001, n = 327) and differed significantly between men and women (2.06±0.48 m/s vs. 2.2±0.52 m/s, P = 0.018, n = 327). However, it did not correlate significantly to height, weight, body mass index, waistline, kidney dimension and the depth for SWV measurement (n = 30). Inter- and intraobserver agreement expressed as intraclass coefficient correlation were 0.64 (95% CI: 0.13 to 0.82, P = 0.011) and 0.6 (95% CI: 0.31 to 0.81, P = 0.001) (n = 40). The mean SWV in healthy volunteers was 2.15±0.51 m/s, while was 1.81±0.43 m/s, 1.79±0.29 m/s, 1.81±0.44 m/s, 1.64±0.55 m/s, and 1.36±0.17 m/s for stage 1, 2, 3, 4 and 5 in CKD patients respectively. The SWV was significantly higher for healthy volunteers compared with each stage in CKD patients. ARFI could not predict the different stages of CKD except stage 5. In CKD patients, SWV correlated to e-GFR (r = 0.3, P = 0.018), to urea nitrogen (r =  −0.3, P = 0.016), and to creatinine (r =  −0.41, P = 0.001). ROC analyses indicated that the area under the ROC curve was 0.752 (95% CI: 0.704 to 0.797) (P<0.001). The cut-off value for predicting CKD was 1.88 m/s (sensitivity 71.87% and specificity 69.69%). Conclusion ARFI may be a potentially useful tool in detecting CKD. PMID

  20. Lipid-laden cells differentially distributed in the aging brain are functionally active and correspond to distinct phenotypes.

    PubMed

    Shimabukuro, Marilia Kimie; Langhi, Larissa Gutman Paranhos; Cordeiro, Ingrid; Brito, José M; Batista, Claudia Maria de Castro; Mattson, Mark P; Mello Coelho, Valeria de

    2016-03-31

    We characterized cerebral Oil Red O-positive lipid-laden cells (LLC) of aging mice evaluating their distribution, morphology, density, functional activities and inflammatory phenotype. We identified LLC in meningeal, cortical and neurogenic brain regions. The density of cerebral LLC increased with age. LLC presenting small lipid droplets were visualized adjacent to blood vessels or deeper in the brain cortical and striatal parenchyma of aging mice. LLC with larger droplets were asymmetrically distributed in the cerebral ventricle walls, mainly located in the lateral wall. We also found that LLC in the subventricular region co-expressed beclin-1 or LC3, markers for autophagosome or autophagolysosome formation, and perilipin (PLIN), a lipid droplet-associated protein, suggesting lipophagic activity. Some cerebral LLC exhibited β galactosidase activity indicating a senescence phenotype. Moreover, we detected production of the pro-inflammatory cytokine TNF-α in cortical PLIN(+) LLC. Some cortical NeuN(+) neurons, GFAP(+) glia limitans astrocytes, Iba-1(+) microglia and S100β(+) ependymal cells expressed PLIN in the aging brain. Our findings suggest that cerebral LLC exhibit distinct cellular phenotypes and may participate in the age-associated neuroinflammatory processes.

  1. Divergent viral presentation among human tumors and adjacent normal tissues

    PubMed Central

    Cao, Song; Wendl, Michael C.; Wyczalkowski, Matthew A.; Wylie, Kristine; Ye, Kai; Jayasinghe, Reyka; Xie, Mingchao; Wu, Song; Niu, Beifang; Grubb, Robert; Johnson, Kimberly J.; Gay, Hiram; Chen, Ken; Rader, Janet S.; Dipersio, John F.; Chen, Feng; Ding, Li

    2016-01-01

    We applied a newly developed bioinformatics system called VirusScan to investigate the viral basis of 6,813 human tumors and 559 adjacent normal samples across 23 cancer types and identified 505 virus positive samples with distinctive, organ system- and cancer type-specific distributions. We found that herpes viruses (e.g., subtypes HHV4, HHV5, and HHV6) that are highly prevalent across cancers of the digestive tract showed significantly higher abundances in tumor versus adjacent normal samples, supporting their association with these cancers. We also found three HPV16-positive samples in brain lower grade glioma (LGG). Further, recurrent HBV integration at the KMT2B locus is present in three liver tumors, but absent in their matched adjacent normal samples, indicating that viral integration induced host driver genetic alterations are required on top of viral oncogene expression for initiation and progression of liver hepatocellular carcinoma. Notably, viral integrations were found in many genes, including novel recurrent HPV integrations at PTPN13 in cervical cancer. Finally, we observed a set of HHV4 and HBV variants strongly associated with ethnic groups, likely due to viral sequence evolution under environmental influences. These findings provide important new insights into viral roles of tumor initiation and progression and potential new therapeutic targets. PMID:27339696

  2. Novel B19-Like Parvovirus in the Brain of a Harbor Seal

    PubMed Central

    Bodewes, Rogier; Rubio García, Ana; Wiersma, Lidewij C. M.; Getu, Sarah; Beukers, Martijn; Schapendonk, Claudia M. E.; van Run, Peter R. W. A.; van de Bildt, Marco W. G.; Poen, Marjolein J.; Osinga, Nynke; Sánchez Contreras, Guillermo J.; Kuiken, Thijs; Smits, Saskia L.; Osterhaus, Albert D. M. E.

    2013-01-01

    Using random PCR in combination with next-generation sequencing, a novel parvovirus was detected in the brain of a young harbor seal (Phoca vitulina) with chronic non-suppurative meningo-encephalitis that was rehabilitated at the Seal Rehabilitation and Research Centre (SRRC) in the Netherlands. In addition, two novel viruses belonging to the family Anelloviridae were detected in the lungs of this animal. Phylogenetic analysis of the coding sequence of the novel parvovirus, tentatively called Seal parvovirus, indicated that this virus belonged to the genus Erythrovirus, to which human parvovirus B19 also belongs. Although no other seals with similar signs were rehabilitated in SRRC in recent years, a prevalence study of tissues of seals from the same area collected in the period 2008-2012 indicated that the Seal parvovirus has circulated in the harbor seal population at least since 2008. The presence of the Seal parvovirus in the brain was confirmed by real-time PCR and in vitro replication. Using in situ hybridization, we showed for the first time that a parvovirus of the genus Erythrovirus was present in the Virchow-Robin space and in cerebral parenchyma adjacent to the meninges. These findings showed that a parvovirus of the genus Erythrovirus can be involved in central nervous system infection and inflammation, as has also been suspected but not proven for human parvovirus B19 infection. PMID:24223918

  3. Novel B19-like parvovirus in the brain of a harbor seal.

    PubMed

    Bodewes, Rogier; Rubio García, Ana; Wiersma, Lidewij C M; Getu, Sarah; Beukers, Martijn; Schapendonk, Claudia M E; van Run, Peter R W A; van de Bildt, Marco W G; Poen, Marjolein J; Osinga, Nynke; Sánchez Contreras, Guillermo J; Kuiken, Thijs; Smits, Saskia L; Osterhaus, Albert D M E

    2013-01-01

    Using random PCR in combination with next-generation sequencing, a novel parvovirus was detected in the brain of a young harbor seal (Phoca vitulina) with chronic non-suppurative meningo-encephalitis that was rehabilitated at the Seal Rehabilitation and Research Centre (SRRC) in the Netherlands. In addition, two novel viruses belonging to the family Anelloviridae were detected in the lungs of this animal. Phylogenetic analysis of the coding sequence of the novel parvovirus, tentatively called Seal parvovirus, indicated that this virus belonged to the genus Erythrovirus, to which human parvovirus B19 also belongs. Although no other seals with similar signs were rehabilitated in SRRC in recent years, a prevalence study of tissues of seals from the same area collected in the period 2008-2012 indicated that the Seal parvovirus has circulated in the harbor seal population at least since 2008. The presence of the Seal parvovirus in the brain was confirmed by real-time PCR and in vitro replication. Using in situ hybridization, we showed for the first time that a parvovirus of the genus Erythrovirus was present in the Virchow-Robin space and in cerebral parenchyma adjacent to the meninges. These findings showed that a parvovirus of the genus Erythrovirus can be involved in central nervous system infection and inflammation, as has also been suspected but not proven for human parvovirus B19 infection.

  4. Perivascular Spaces--MRI Marker of Inflammatory Activity in the Brain?

    ERIC Educational Resources Information Center

    Wuerfel, Jens; Haertle, Mareile; Waiczies, Helmar; Tysiak, Eva; Bechmann, Ingo; Wernecke, Klaus D.; Zipp, Frauke; Paul, Friedemann

    2008-01-01

    The Virchow-Robin spaces (VRS), perivascular compartments surrounding small blood vessels as they penetrate the brain parenchyma, are increasingly recognized for their role in leucocyte trafficking as well as for their potential to modulate immune responses. In the present study, we investigated VRS numbers and volumes in different brain regions…

  5. Improving parenchyma segmentation by simultaneous estimation of tissue property T1 map and group-wise registration of inversion recovery MR breast images.

    PubMed

    Xing, Ye; Xue, Zhong; Englander, Sarah; Schnall, Mitchell; Shen, Dinggang

    2008-01-01

    The parenchyma tissue in the breast has a strong relation with predictive biomarkers of breast cancer. To better segment parenchyma, we perform segmentation on estimated tissue property T1 map. To improve the estimation of tissue property (T1) which is the basis for parenchyma segmentation, we present an integrated algorithm for simultaneous T1 map estimation, T1 map based parenchyma segmentation and group-wise registration on series of inversion recovery magnetic resonance (MR) breast images. The advantage of using this integrated algorithm is that the simultaneous T1 map estimation (E-step) and group-wise registration (R-step) could benefit each other and jointly improve parenchyma segmentation. In particular, in E-step, T1 map based segmentation could help perform an edge-preserving smoothing on the tentatively estimated noisy T1 map, and could also help provide tissue probability maps to be robustly registered in R-step. Meanwhile, the improved estimation of T1 map could help segment parenchyma in a more accurate way. In R-step, for robust registration, the group-wise registration is performed on the tissue probability maps produced in E-step, rather than the original inversion recovery MR images, since tissue probability maps are the intrinsic tissue property which is invariant to the use of different imaging parameters. The better alignment of images achieved in R-step can help improve T1 map estimation and indirectly the T1 map based parenchyma segmentation. By iteratively performing E-step and R-step, we can simultaneously obtain better results for T1 map estimation, T1 map based segmentation, group-wise registration, and finally parenchyma segmentation.

  6. The effects of ductal ligation on the parenchyma of salivary glands of cat studied by enzyme histochemical methods.

    PubMed

    Harrison, J D; Garrett, J R

    1976-01-01

    Submandibular, sublingual and parotid glands of cat have been studied following periods of ductal ligation ranging from 1 day to 1 year. An increased prominence of granules of acid phosphatase, beta-glucuronidase and E600-resistant esterase reaction products was sometimes seen in acinar cells and atropic striated ductal cells, and probably represents increased lysosomal enzymic activity, which may be of importance in the adapation of the parenchyma to the altered environment. Other reaction products often appeared to be at normal levels in parenchymal structures that were not very atrophic, and at reduced levels in those that were very atrophic, suggesting a reduction of functional activity in these structures.

  7. On the time-course of adjacent and non-adjacent transposed-letter priming

    PubMed Central

    Ktori, Maria; Kingma, Brechtsje; Hannagan, Thomas; Holcomb, Phillip J.; Grainger, Jonathan

    2014-01-01

    We compared effects of adjacent (e.g., atricle-ARTICLE) and non-adjacent (e.g., actirle-ARTICLE) transposed-letter (TL) primes in an ERP study using the sandwich priming technique. TL priming was measured relative to the standard double-substitution condition. We found significantly stronger priming effects for adjacent transpositions than non-adjacent transpositions (with 2 intervening letters) in behavioral responses (lexical decision latencies), and the adjacent priming effects emerged earlier in the ERP signal, at around 200 ms post-target onset. Non-adjacent priming effects emerged about 50 ms later and were short-lived, being significant only in the 250-300 ms time-window. Adjacent transpositions on the other hand continued to produce priming in the N400 time-window (300-500 ms post-target onset). This qualitatively different pattern of priming effects for adjacent and non-adjacent transpositions is discussed in the light of different accounts of letter transposition effects, and the utility of drawing a distinction between positional flexibility and positional noise. PMID:25364497

  8. Effect of Macerase, Oxalic Acid, and EGTA on Deep Supercooling and Pit Membrane Structure of Xylem Parenchyma of Peach

    PubMed Central

    Wisniewski, Michael; Davis, Glen; Arora, Rajeev

    1991-01-01

    The object of this study was to determine if calcium cross-linking of pectin in the pit membrane of xylem parenchyma restricts water movement which results in deep supercooling. Current year shoots of `Loring' peach (Prunus persica) were infiltrated with oxalic acid or EGTA solutions for 24 or 48 hours and then either prepared for ultrastructural analysis or subjected to differential thermal analysis. The effect of 0.25 to 1.0% pectinase (weight/volume) on deep supercooling was also investigated. The use of 5 to 50 millimolar oxalic acid and pectinase resulted in a significant reduction (flattening) of the low temperature exotherm and a distinct swelling and partial degradation of the pit membrane. EGTA (10 millimolar) for 24 or 48 hours shifted the low temperature exotherm to warmer temperatures and effected the outermost layer of the pit membrane. A hypothesis is presented on pectin-mediated regulation of deep supercooling of xylem parenchyma. ImagesFigure 3Figure 4Figure 5Figure 6Figure 7Figure 8 PMID:16668341

  9. Absence of fibromodulin affects matrix composition, collagen deposition and cell turnover in healthy and fibrotic lung parenchyma

    PubMed Central

    Rydell-Törmänen, Kristina; Andréasson, Kristofer; Hesselstrand, Roger; Westergren-Thorsson, Gunilla

    2014-01-01

    The ECM exerts great effects on cells, and changed composition may therefore have profound impact. Small leucine-rich proteoglycans, e.g. fibromodulin, are essential in collagen assembly. Our aim was to investigate the role of fibromodulin in healthy and fibrotic lung parenchyma, theorizing that fibromodulin-deficient animals would be protected against fibrosis. Repeated subcutaneous bleomycin-injections were given to wild type and fibromodulin-deficient mice, inducing pulmonary fibrosis. Development of fibrosis, ECM composition, cell turnover and inflammatory responses were investigated. Fibromodulin-deficient animals were not protected from fibrosis, but the composition of the matrix was affected, with decreased Collagen I in fibromodulin-deficient animals, both in controls (0.07 ± 0.04% vs. 0.18 ± 0.07% tissue area) and after bleomycin (0.37 ± 0.16% vs. 0.61 ± 0.21% tissue area). Biglycan was increased in fibromodulin-deficient animals, whereas decorin was decreased. Furthermore, bleomycin increased cell turnover in wild type, but only proliferation in fibromodulin-deficient animals, resulting in hyperplasia. In addition, the bleomycin-induced immune response was affected in fibromodulin-deficient animals. We thus conclude that fibromodulin has a profound effect on ECM, both in healthy and fibrotic lung parenchyma, and may be providing a permissive microenvironment affecting cell turnover. Furthermore, this study highlights the need to acknowledge specific ECM components, when assessing tissue properties and ultimately cell behaviour. PMID:25230586

  10. Read-through transcripts in normal human lung parenchyma are down-regulated in lung adenocarcinoma

    PubMed Central

    Cotroneo, Chiara E.; Galvan, Antonella; Noci, Sara; Piazza, Rocco; Pirola, Alessandra; Spinelli, Roberta; Incarbone, Matteo; Palleschi, Alessandro; Rosso, Lorenzo; Santambrogio, Luigi; Dragani, Tommaso A.; Colombo, Francesca

    2016-01-01

    Read-through transcripts result from the continuous transcription of adjacent, similarly oriented genes, with the splicing out of the intergenic region. They have been found in several neoplastic and normal tissues, but their pathophysiological significance is unclear. We used high-throughput sequencing of cDNA fragments (RNA-Seq) to identify read-through transcripts in the non-involved lung tissue of 64 surgically treated lung adenocarcinoma patients. A total of 52 distinct read-through species was identified, with 24 patients having at least one read-through event, up to a maximum of 17 such transcripts in one patient. Sanger sequencing validated 28 of these transcripts and identified an additional 15, for a total of 43 distinct read-through events involving 35 gene pairs. Expression levels of 10 validated read-through transcripts were measured by quantitative PCR in pairs of matched non-involved lung tissue and lung adenocarcinoma tissue from 45 patients. Higher expression levels were observed in normal lung tissue than in the tumor counterpart, with median relative quantification ratios between normal and tumor varying from 1.90 to 7.78; the difference was statistically significant (P < 0.001, Wilcoxon's signed-rank test for paired samples) for eight transcripts: ELAVL1–TIMM44, FAM162B–ZUFSP, IFNAR2–IL10RB, INMT–FAM188B, KIAA1841–C2orf74, NFATC3–PLA2G15, SIRPB1–SIRPD, and SHANK3–ACR. This report documents the presence of read-through transcripts in apparently normal lung tissue, with inter-individual differences in patterns and abundance. It also shows their down-regulation in tumors, suggesting that these chimeric transcripts may function as tumor suppressors in lung tissue. PMID:27058892

  11. Wood anatomical correlates with theoretical conductivity and wood density across China: evolutionary evidence of the functional differentiation of axial and radial parenchyma

    PubMed Central

    Zheng, Jingming; Martínez-Cabrera, Hugo I.

    2013-01-01

    Background and Aims In recent years considerable effort has focused on linking wood anatomy and key ecological traits. Studies analysing large databases have described how these ecological traits vary as a function of wood anatomical traits related to conduction and support, but have not considered how these functions interact with cells involved in storage of water and carbohydrates (i.e. parenchyma cells). Methods We analyzed, in a phylogenetic context, the functional relationship between cell types performing each of the three xylem functions (conduction, support and storage) and wood density and theoretical conductivity using a sample of approx. 800 tree species from China. Key Results Axial parenchyma and rays had distinct evolutionary correlation patterns. An evolutionary link was found between high conduction capacity and larger amounts of axial parenchyma that is probably related to water storage capacity and embolism repair, while larger amounts of ray tissue have evolved with increased mechanical support and reduced hydraulic capacity. In a phylogenetic principal component analysis this association of axial parenchyma with increased conduction capacity and rays with wood density represented orthogonal axes of variation. In multivariate space, however, the proportion of rays might be positively associated with conductance and negatively with wood density, indicating flexibility in these axes in species with wide rays. Conclusions The findings suggest that parenchyma types may differ in function. The functional axes represented by different cell types were conserved across lineages, suggesting a significant role in the ecological strategies of the angiosperms. PMID:23904446

  12. Fully automatized renal parenchyma volumetry using a support vector machine based recognition system for subject-specific probability map generation in native MR volume data

    NASA Astrophysics Data System (ADS)

    Gloger, Oliver; Tönnies, Klaus; Mensel, Birger; Völzke, Henry

    2015-11-01

    In epidemiological studies as well as in clinical practice the amount of produced medical image data strongly increased in the last decade. In this context organ segmentation in MR volume data gained increasing attention for medical applications. Especially in large-scale population-based studies organ volumetry is highly relevant requiring exact organ segmentation. Since manual segmentation is time-consuming and prone to reader variability, large-scale studies need automatized methods to perform organ segmentation. Fully automatic organ segmentation in native MR image data has proven to be a very challenging task. Imaging artifacts as well as inter- and intrasubject MR-intensity differences complicate the application of supervised learning strategies. Thus, we propose a modularized framework of a two-stepped probabilistic approach that generates subject-specific probability maps for renal parenchyma tissue, which are refined subsequently by using several, extended segmentation strategies. We present a three class-based support vector machine recognition system that incorporates Fourier descriptors as shape features to recognize and segment characteristic parenchyma parts. Probabilistic methods use the segmented characteristic parenchyma parts to generate high quality subject-specific parenchyma probability maps. Several refinement strategies including a final shape-based 3D level set segmentation technique are used in subsequent processing modules to segment renal parenchyma. Furthermore, our framework recognizes and excludes renal cysts from parenchymal volume, which is important to analyze renal functions. Volume errors and Dice coefficients show that our presented framework outperforms existing approaches.

  13. Relationship of nuclease activity and synthesis to senescence of corn (Zea mays L.) stalk pith, cob parenchyma and first developed leaf tissues.

    PubMed

    BeMiller, J N; Liu TU, Y S; Liu, C R; Pappelis, A J

    1976-01-01

    An increase in total RNase activity was associated with three patterns of cell senescence in corn (Zea mays L.) (cv. WF9 X 38-11) cob parenchyma during the first two weeks following silking, stalk pith tissue after internode elongation and the first developed leaf of seedlings. Stalk pith tissue had two RNase activities, one inhibited by EDTA and one not. Both remained in approximately equal amounts in young to old pith tissue. In the first developed leaf of seedlings, the activity not inhibited by EDTA remained at a constant low level during the period studied, while the other activity varied. No inhibition by EDTA was found in cob parenchyma tissue. Incubation of sections of cob parenchyma and stalk pith tissues suggested that the total RNase activity of cob parenchyma is very stable and that of stalk pith tissue is relatively stable. An age-related increase in DNase activity was found in stalk pith tissue and in the first developed leaf of seedlings, but not in cob parenchyma tissue.

  14. Detecting gas‐induced vasomotor changes via blood oxygenation level‐dependent contrast in healthy breast parenchyma and breast carcinoma

    PubMed Central

    Wallace, Tess E.; Patterson, Andrew J.; Abeyakoon, Oshaani; Bedair, Reem; Manavaki, Roido; McLean, Mary A.; O'Connor, James P.B.; Graves, Martin J.

    2016-01-01

    Purpose To evaluate blood oxygenation level‐dependent (BOLD) contrast changes in healthy breast parenchyma and breast carcinoma during administration of vasoactive gas stimuli. Materials and Methods Magnetic resonance imaging (MRI) was performed at 3T in 19 healthy premenopausal female volunteers using a single‐shot fast spin echo sequence to acquire dynamic T 2‐weighted images. 2% (n = 9) and 5% (n = 10) carbogen gas mixtures were interleaved with either medical air or oxygen in 2‐minute blocks, for four complete cycles. A 12‐minute medical air breathing period was used to determine background physiological modulation. Pixel‐wise correlation analysis was applied to evaluate response to the stimuli in breast parenchyma and these results were compared to the all‐air control. The relative BOLD effect size was compared between two groups of volunteers scanned in different phases of the menstrual cycle. The optimal stimulus design was evaluated in five breast cancer patients. Results Of the four stimulus combinations tested, oxygen vs. 5% carbogen produced a response that was significantly stronger (P < 0.05) than air‐only breathing in volunteers. Subjects imaged during the follicular phase of their cycle when estrogen levels typically peak exhibited a significantly smaller BOLD response (P = 0.01). Results in malignant tissue were variable, with three out of five lesions exhibiting a diminished response to the gas stimulus. Conclusion Oxygen vs. 5% carbogen is the most robust stimulus for inducing BOLD contrast, consistent with the opposing vasomotor effects of these two gases. Measurements may be confounded by background physiological fluctuations and menstrual cycle changes. J. Magn. Reson. Imaging 2016;44:335–345. PMID:26898173

  15. Differential permeability of the blood-brain barrier in experimental brain metastases produced by human neoplasms implanted into nude mice.

    PubMed Central

    Zhang, R. D.; Price, J. E.; Fujimaki, T.; Bucana, C. D.; Fidler, I. J.

    1992-01-01

    This study clarified whether and when the blood-brain barrier in experimental brain metastases is impaired by using hydrosoluble sodium fluorescein (MW 376) as a blood-brain barrier function indicator. Cells from eight human tumor lines (four melanomas, two breast carcinomas, one colon carcinoma, and one renal carcinoma) were inoculated into the internal carotid artery of nude mice. Brain metastases at different stages of development were sampled and the permeability of the blood-brain barrier around the metastases determined. Histologic examination showed two patterns of tumor growth. In the first, tumor cells formed isolated, well-defined nodules in the parenchyma of the brain. In lesions smaller than 0.2 mm2, the blood-brain barrier was intact. In the second, small diffuse nests of tumor cells were distributed throughout the brain parenchyma. The blood-brain barrier was intact until the small tumor cell colonies coalesced to form large tumor masses. These results suggest that the permeability of the blood-brain barrier varies among different experimental brain metastases and that its function is related to the growth pattern and size of the lesions. Images Figure 1 Figure 5 Figure 6 PMID:1443046

  16. Adjacent Segment Pathology after Anterior Cervical Fusion

    PubMed Central

    Chung, Jae Yoon; Park, Jong-Beom; Seo, Hyoung-Yeon

    2016-01-01

    Anterior cervical fusion has become a standard of care for numerous pathologic conditions of the cervical spine. However, subsequent development of clinically significant disc disease at levels adjacent to fused discs is a serious long-term complication of this procedure. As more patients live longer after surgery, it is foreseeable that adjacent segment pathology (ASP) will develop in increasing numbers of patients. Also, ASP has been studied more intensively with the recent popularity of motion preservation technologies like total disc arthroplasty. The true nature and scope of ASP remains poorly understood. The etiology of ASP is most likely multifactorial. Various factors including altered biomechanical stresses, surgical disruption of soft tissue and the natural history of cervical disc disease contribute to the development of ASP. General factors associated with disc degeneration including gender, age, smoking and sports may play a role in the development of ASP. Postoperative sagittal alignment and type of surgery are also considered potential causes of ASP. Therefore, a spine surgeon must be particularly careful to avoid unnecessary disruption of the musculoligamentous structures, reduced risk of direct injury to the disc during dissection and maintain a safe margin between the plate edge and adjacent vertebrae during anterior cervical fusion. PMID:27340541

  17. Superresolution Imaging of Aquaporin-4 Cluster Size in Antibody-Stained Paraffin Brain Sections.

    PubMed

    Smith, Alex J; Verkman, Alan S

    2015-12-15

    The water channel aquaporin-4 (AQP4) forms supramolecular clusters whose size is determined by the ratio of M1- and M23-AQP4 isoforms. In cultured astrocytes, differences in the subcellular localization and macromolecular interactions of small and large AQP4 clusters results in distinct physiological roles for M1- and M23-AQP4. Here, we developed quantitative superresolution optical imaging methodology to measure AQP4 cluster size in antibody-stained paraffin sections of mouse cerebral cortex and spinal cord, human postmortem brain, and glioma biopsy specimens. This methodology was used to demonstrate that large AQP4 clusters are formed in AQP4(-/-) astrocytes transfected with only M23-AQP4, but not in those expressing only M1-AQP4, both in vitro and in vivo. Native AQP4 in mouse cortex, where both isoforms are expressed, was enriched in astrocyte foot-processes adjacent to microcapillaries; clusters in perivascular regions of the cortex were larger than in parenchymal regions, demonstrating size-dependent subcellular segregation of AQP4 clusters. Two-color superresolution imaging demonstrated colocalization of Kir4.1 with AQP4 clusters in perivascular areas but not in parenchyma. Surprisingly, the subcellular distribution of AQP4 clusters was different between gray and white matter astrocytes in spinal cord, demonstrating regional specificity in cluster polarization. Changes in AQP4 subcellular distribution are associated with several neurological diseases and we demonstrate that AQP4 clustering was preserved in a postmortem human cortical brain tissue specimen, but that AQP4 was not substantially clustered in a human glioblastoma specimen despite high-level expression. Our results demonstrate the utility of superresolution optical imaging for measuring the size of AQP4 supramolecular clusters in paraffin sections of brain tissue and support AQP4 cluster size as a primary determinant of its subcellular distribution.

  18. Superresolution Imaging of Aquaporin-4 Cluster Size in Antibody-Stained Paraffin Brain Sections

    PubMed Central

    Smith, Alex J.; Verkman, Alan S.

    2015-01-01

    The water channel aquaporin-4 (AQP4) forms supramolecular clusters whose size is determined by the ratio of M1- and M23-AQP4 isoforms. In cultured astrocytes, differences in the subcellular localization and macromolecular interactions of small and large AQP4 clusters results in distinct physiological roles for M1- and M23-AQP4. Here, we developed quantitative superresolution optical imaging methodology to measure AQP4 cluster size in antibody-stained paraffin sections of mouse cerebral cortex and spinal cord, human postmortem brain, and glioma biopsy specimens. This methodology was used to demonstrate that large AQP4 clusters are formed in AQP4−/− astrocytes transfected with only M23-AQP4, but not in those expressing only M1-AQP4, both in vitro and in vivo. Native AQP4 in mouse cortex, where both isoforms are expressed, was enriched in astrocyte foot-processes adjacent to microcapillaries; clusters in perivascular regions of the cortex were larger than in parenchymal regions, demonstrating size-dependent subcellular segregation of AQP4 clusters. Two-color superresolution imaging demonstrated colocalization of Kir4.1 with AQP4 clusters in perivascular areas but not in parenchyma. Surprisingly, the subcellular distribution of AQP4 clusters was different between gray and white matter astrocytes in spinal cord, demonstrating regional specificity in cluster polarization. Changes in AQP4 subcellular distribution are associated with several neurological diseases and we demonstrate that AQP4 clustering was preserved in a postmortem human cortical brain tissue specimen, but that AQP4 was not substantially clustered in a human glioblastoma specimen despite high-level expression. Our results demonstrate the utility of superresolution optical imaging for measuring the size of AQP4 supramolecular clusters in paraffin sections of brain tissue and support AQP4 cluster size as a primary determinant of its subcellular distribution. PMID:26682810

  19. Brain iron homeostasis.

    PubMed

    Moos, Torben

    2002-11-01

    deficiency altered the cellular content of these proteins so that transferrin receptors were higher and ferritin lower. The transport of iron from brain to blood was addressed in the last part of the thesis. It was found that in the case of iron and transferrin, there is no evidence showing other significant routes of transport from the brain extracellular fluid into the blood than drainage to the ventricular system followed by export to the blood via the arachnoid villi. The turnover of transferrin in the CSF was found to be very high. For reasons mentioned above, transferrin of the CSF is of little significance for transport and cellular delivery of iron to transferrin receptor-expressing neurons. Instead, transferrin of the CSF probably plays a significant role for neutralization and export to the blood of metals, including iron. Once appearing in blood, transferrin of the CSF was degraded at the same rate as intravenously injected transferrin, which indicates that the transferrin of CSF is not altered to an extent that changes its catabolism during the passage from CSF to blood plasma. The metabolism of iron in the developing brain was found to differ markedly when compared to that of the adult brain. A developing regulated transfer of iron to the brain was reflected morphologically by a higher content of transferrin receptors and non-heme iron in endothelial cells of the developing rat brain than in the adult. Neurons had a very low level of transferrin receptors. After about 20 days of age, iron transport into the brain decreased rapidly, and transferrin receptors appeared on neurons. Iron and transferrin injected into the ventricular system of the developing brain were much more widely distributed in the brain parenchyma than in the adult brain. This high accumulation of substances injected into the ventricles in young animals is probably due to the lower rate of production and turnover of CSF, which will increase the time available for diffusion of proteins into the

  20. Adjacent-level arthroplasty following cervical fusion.

    PubMed

    Rajakumar, Deshpande V; Hari, Akshay; Krishna, Murali; Konar, Subhas; Sharma, Ankit

    2017-02-01

    OBJECTIVE Adjacent-level disc degeneration following cervical fusion has been well reported. This condition poses a major treatment dilemma when it becomes symptomatic. The potential application of cervical arthroplasty to preserve motion in the affected segment is not well documented, with few studies in the literature. The authors present their initial experience of analyzing clinical and radiological results in such patients who were treated with arthroplasty for new or persistent arm and/or neck symptoms related to neural compression due to adjacent-segment disease after anterior cervical discectomy and fusion (ACDF). METHODS During a 5-year period, 11 patients who had undergone ACDF anterior cervical discectomy and fusion (ACDF) and subsequently developed recurrent neck or arm pain related to adjacent-level cervical disc disease were treated with cervical arthroplasty at the authors' institution. A total of 15 devices were implanted (range of treated levels per patient: 1-3). Clinical evaluation was performed both before and after surgery, using a visual analog scale (VAS) for pain and the Neck Disability Index (NDI). Radiological outcomes were analyzed using pre- and postoperative flexion/extension lateral radiographs measuring Cobb angle (overall C2-7 sagittal alignment), functional spinal unit (FSU) angle, and range of motion (ROM). RESULTS There were no major perioperative complications or device-related failures. Statistically significant results, obtained in all cases, were reflected by an improvement in VAS scores for neck/arm pain and NDI scores for neck pain. Radiologically, statistically significant increases in the overall lordosis (as measured by Cobb angle) and ROM at the treated disc level were observed. Three patients were lost to follow-up within the first year after arthroplasty. In the remaining 8 cases, the duration of follow-up ranged from 1 to 3 years. None of these 8 patients required surgery for the same vertebral level during the follow

  1. Experimental COPD induced by solid combustible burn smoke in rats: a study of the emphysematous changes of the pulmonary parenchyma.

    PubMed

    Murărescu, Elena Doina; Eloae-Zugun, Fl; Mihailovici, Maria Sultana

    2008-01-01

    According to the GOLD 2006 definition, COPD is a preventable and treatable pathological situation characterized by the partially reversible airflow limitation determined by a variable proportion mixture of small airways disease (obliterative bronchiolitis) and parenchyma destruction (emphysema). A major impediment in the study of the COPD is represented by the fact the fundamental morphological changes that determine the major pulmonary dysfunction take place in the small, peripheral, airways, at the bronchiolo-alveolar attachments. That is why the experimental model of COPD developed progressively to the transgenic mouse. There are many experimental studies on the animal models that have obtained emphysema rapidly through intratraheal instillation of elastasis or bronchitis/bronchiolitis through intratraheal instillation of particles. It is accepted that the unnatural character of aggression, that does not permit the natural evolution of the inflammatory phenomenon, limits these models and tissue remodeling that take place in COPD patients. It is well known that cigarette smoking is a major cause of COPD. There have been reported some cases of COPD in never smoking patients exposed to air pollutants. We aimed to create an experimental model of COPD in rat through exposure to smoke resulted from solid combustibles burn for the same period and in the same conditions of cigarette smoke exposure and to compare the pulmonary morphological changes. Thirty Wistar rats were divided into three groups (n = 10): (1) the control group (C), (2) the cigarette smoke group (CS), and (3) the solid combustible smoke group (SCS). Apart from the control group, these were treated with solid combustibles smoke (SCS group) or cigarette smoke (CS group) for six months. Morphological and morphometry studies have been assessed. We have established a rat COPD model based on natural cigarette smoke exposure versus solid combustible burn resulted smoke, usable for a further approach in human

  2. Spatiotemporal morphometry of adjacent tissue layers with application to the study of sulcal formation

    PubMed Central

    Rajagopalan, Vidya; Scott, Julia; Habas, Piotr A.; Kim, Kio; Rousseau, Francois; Glenn, Orit A.; Barkovich, A. James; Studholme, Colin

    2012-01-01

    The process of brain growth involves the expansion of tissue at different rates at different points within the brain. As the layers within the developing brain evolve they can thicken or increase in area as the brain surface begins to fold. In this work we propose a new spatiotemporal formulation of tensor based volume morphometry that is derived in relation to tissue boundaries. This allows the study of the directional properties of tissue growth by separately characterizing the changes in area and thickness of the adjacent layers. The approach uses temporally weighted, local regression across a population of anatomies with different ages to model changes in components of the growth radial and tangential to the boundary between tissue layers. The formulation is applied to the study of sulcal formation from in-utero MR imaging of human fetal brain anatomy. Results show that the method detects differential growth of tissue layers adjacent to the cortical surface, particularly at sulcal locations, as early as 22 gestational weeks. PMID:21995063

  3. Morphologic Effect of Dimethyl Sulfoxide on the Blood-Brain Barrier

    NASA Astrophysics Data System (ADS)

    Broadwell, Richard D.; Salcman, Michael; Kaplan, Richard S.

    1982-07-01

    Dimethyl sulfoxide (DMSO) opens the blood-brain barrier of mice to the enzymatic tracer horseradish peroxidase. A single injection of horseradish peroxidase in 10 to 15 percent DMSO into the tail vein along with 10 to 15 percent DMSO delivered intraperitoneally allowed horseradish peroxidase to fill the extracellular clefts throughout the brain within 2 hours. In the absence of DMSO, peroxidase failed to enter brain parenchyma except through the circumventricular organs. Opening of the blood-brain barrier by DMSO is reversible. Dimethyl sulfoxide stimulated the pinocytosis of horseradish peroxidase by the cerebral endothelium; the peroxidase was then directed to lysosomal dense bodies for degradation. Vesicular transport of horseradish peroxidase from the luminal to the abluminal wall of the endothelial cell was not observed. Dimethyl sulfoxide did not alter the morphology of endothelial cells or brain parenchyma.

  4. Noninvasive delivery of stealth, brain-penetrating nanoparticles across the blood-brain barrier using MRI-guided focused ultrasound

    PubMed Central

    Miller, G. Wilson; Song, Ji; Louttit, Cameron; Klibanov, Alexander L; Shih, Ting-Yu; Swaminathan, Ganesh; Tamargo, Rafael J.; Woodworth, Graeme F.; Hanes, Justin; Price, Richard J.

    2014-01-01

    The blood-brain barrier (BBB) presents a significant obstacle for the treatment of many central nervous system (CNS) disorders, including invasive brain tumors, Alzheimer’s, Parkinson’s and stroke. Therapeutics must be capable of bypassing the BBB and also penetrate the brain parenchyma to achieve a desired effect within the brain. In this study, we test the unique combination of a noninvasive approach to BBB permeabilization with a therapeutically relevant polymeric nanoparticle platform capable of rapidly penetrating within the brain microenvironment. MR-guided focused ultrasound (FUS) with intravascular microbubbles (MBs) is able to locally and reversibly disrupt the BBB with submillimeter spatial accuracy. Densely poly(ethylene-co-glycol) (PEG) coated, brain-penetrating nanoparticles (BPNs) are long-circulating and diffuse 10-fold slower in normal rat brain tissue compared to diffusion in water. Following intravenous administration of model and biodegradable BPN in normal healthy rats, we demonstrate safe, pressure-dependent delivery of 60 nm BPNs to the brain parenchyma in regions where the BBB is disrupted by FUS and MBs. Delivery of BPNs with MR-guided FUS has the potential to improve efficacy of treatments for many CNS diseases, while reducing systemic side effects by providing sustained, well-dispersed drug delivery into select regions of the brain. PMID:24979210

  5. Mannitol-enhanced, fluid-phase endocytosis in storage parenchyma cells of celery (Apium graveolens; Apiaceae) petioles.

    PubMed

    Etxeberria, Ed; Gonzalez, Pedro; Pozueta-Romero, Javier

    2007-06-01

    We recently demonstrated the occurrence of a sucrose-enhanced, fluid-phase endocytic (FPE) mechanism of nutrient uptake in heterotrophic cells. In the present work, the possible enhancement/induction of FPE by photoassimilates other than sucrose was investigated by measuring the incorporation of the fluorescent endocytosis marker d-TR (dextran-Texas red, 3000 mw) into celery (Apium graveolens) petiole storage parenchyma (CSP), a tissue that transports and accumulates mannitol. Mannitol uptake in these cells is biphasic, with a hyperbolic phase at concentrations below 20 mM and a linear phase above 20 mM external solute concentration. In the absence of mannitol, or in its presence at concentrations within the hyperbolic phase, CSP cells accumulated low levels of d-TR. Conversely, d-TR accumulation by CSP cells was greatly enhanced in the presence of mannitol at concentrations within the linear phase. At high external mannitol concentration, d-TR accumulation was prevented by the endocytic inhibitors LY294002 and latrunculin B. In addition, d-TR uptake was temperature dependent under high mannitol concentration. Microscopic observations revealed that d-TR accumulated in the vacuole. These data support the occurrence of an FPE mechanism in CSP cells that participates in trapping and transport of photoassimilates to the vacuole. The FPE mechanism is enhanced by high mannitol concentrations.

  6. Phloem as capacitor: radial transfer of water into xylem of tree stems occurs via symplastic transport in ray parenchyma.

    PubMed

    Pfautsch, Sebastian; Renard, Justine; Tjoelker, Mark G; Salih, Anya

    2015-03-01

    The transfer of water from phloem into xylem is thought to mitigate increasing hydraulic tension in the vascular system of trees during the diel cycle of transpiration. Although a putative plant function, to date there is no direct evidence of such water transfer or the contributing pathways. Here, we trace the radial flow of water from the phloem into the xylem and investigate its diel variation. Introducing a fluorescent dye (0.1% [w/w] fluorescein) into the phloem water of the tree species Eucalyptus saligna allowed localization of the dye in phloem and xylem tissues using confocal laser scanning microscopy. Our results show that the majority of water transferred between the two tissues is facilitated via the symplast of horizontal ray parenchyma cells. The method also permitted assessment of the radial transfer of water during the diel cycle, where changes in water potential gradients between phloem and xylem determine the extent and direction of radial transfer. When injected during the morning, when xylem water potential rapidly declined, fluorescein was translocated, on average, farther into mature xylem (447 ± 188 µm) compared with nighttime, when xylem water potential was close to zero (155 ± 42 µm). These findings provide empirical evidence to support theoretical predictions of the role of phloem-xylem water transfer in the hydraulic functioning of plants. This method enables investigation of the role of phloem tissue as a dynamic capacitor for water storage and transfer and its contribution toward the maintenance of the functional integrity of xylem in trees.

  7. Presence of supercooling-facilitating (anti-ice nucleation) hydrolyzable tannins in deep supercooling xylem parenchyma cells in Cercidiphyllum japonicum.

    PubMed

    Wang, Donghui; Kasuga, Jun; Kuwabara, Chikako; Endoh, Keita; Fukushi, Yukiharu; Fujikawa, Seizo; Arakawa, Keita

    2012-04-01

    Xylem parenchyma cells (XPCs) in trees adapt to subzero temperatures by deep supercooling. Our previous study indicated the possibility of the presence of diverse kinds of supercooling-facilitating (SCF; anti-ice nucleation) substances in XPCs of katsura tree (Cercidiphyllum japonicum), all of which might have an important role in deep supercooling of XPCs. In the previous study, a few kinds of SCF flavonol glycosides were identified. Thus, in the present study, we tried to identify other kinds of SCF substances in XPCs of katsura tree. SCF substances were purified from xylem extracts by silica gel column chromatography and Sephadex LH-20 column chromatography. Then, four SCF substances isolated were identified by UV, mass and nuclear magnetic resonance analyses. The results showed that the four kinds of hydrolyzable gallotannins, 2,2',5-tri-O-galloyl-α,β-D-hamamelose (trigalloyl Ham or kurigalin), 1,2,6-tri-O-galloyl-β-D-glucopyranoside (trigalloyl Glc), 1,2,3,6-tetra-O-galloyl-β-D-glucopyranoside (tetragalloyl Glc) and 1,2,3,4,6-penta-O-galloyl-β-D-glucopyranoside (pentagalloyl Glc), in XPCs exhibited supercooling capabilities in the range of 1.5-4.5°C, at a concentration of 1 mg mL⁻¹. These SCF substances, including flavonol glycosides and hydrolyzable gallotannins, may contribute to the supercooling in XPCs of katsura tree.

  8. Anti-ice nucleation activity in xylem extracts from trees that contain deep supercooling xylem parenchyma cells.

    PubMed

    Kasuga, Jun; Mizuno, Kaoru; Arakawa, Keita; Fujikawa, Seizo

    2007-12-01

    Boreal hardwood species, including Japanese white birch (Betula platyphylla Sukat. var. japonica Hara), Japanese chestnut (Castanea crenata Sieb. et Zucc.), katsura tree (Cercidiphyllum japonicum Sieb. et Zucc.), Siebold's beech (Fagus crenata Blume), mulberry (Morus bombycis Koidz.), and Japanese rowan (Sorbus commixta Hedl.), had xylem parenchyma cells (XPCs) that adapt to subfreezing temperatures by deep supercooling. Crude extracts from xylem in all these trees were found to have anti-ice nucleation activity that promoted supercooling capability of water as measured by a droplet freezing assay. The magnitude of increase in supercooling capability of water droplets in the presence of ice-nucleation bacteria, Erwinia ananas, was higher in the ranges from 0.1 to 1.7 degrees C on addition of crude xylem extracts than freezing temperature of water droplets on addition of glucose in the same concentration (100 mosmol/kg). Crude xylem extracts from C. japonicum provided the highest supercooling capability of water droplets. Our additional examination showed that crude xylem extracts from C. japonicum exhibited anti-ice nucleation activity toward water droplets containing a variety of heterogeneous ice nucleators, including ice-nucleation bacteria, not only E. ananas but also Pseudomonas syringae (NBRC3310) or Xanthomonas campestris, silver iodide or airborne impurities. However, crude xylem extracts from C. japonicum did not affect homogeneous ice nucleation temperature as analyzed by emulsified micro-water droplets. The possible role of such anti-ice nucleation activity in crude xylem extracts in deep supercooling of XPCs is discussed.

  9. Roles of cell walls and intracellular contents in supercooling capability of xylem parenchyma cells of boreal trees.

    PubMed

    Kasuga, Jun; Endoh, Keita; Yoshiba, Megumi; Taido, Ippei; Arakawa, Keita; Uemura, Matsuo; Fujikawa, Seizo

    2013-05-01

    The supercooling capability of xylem parenchyma cells (XPCs) in boreal hardwood species differs depending not only on species, but also season. In this study, the roles of cell walls and intracellular contents in supercooling capability of XPCs were examined in three boreal hardwood species, Japanese beech, katsura tree and mulberry, whose supercooling capability differs largely depending on species and season. XPCs in these species harvested in winter and summer were treated by rapid freezing and thawing (RFT samples) or by RFT with further washing (RFTW samples) to remove intracellular contents from XPCs in order to examine the roles of cell walls in supercooling. RFT samples were also treated with glucose solution (RFTG samples) to examine roles of intracellular contents in supercooling. The supercooling capabilities of these samples were examined by differential thermal analysis after ultrastructural observation of XPCs by a cryo-scanning electron microscope to confirm effects of the above treatments. XPCs in RFTW samples showed a large reduction in supercooling capability to similar temperatures regardless of species or season. On the other hand, XPCs in RFTG samples showed a large increase in supercooling capability to similar temperatures regardless of species or season. These results indicate that although cell walls have an important role in maintenance of supercooling, change in supercooling capability of XPCs is induced by change in intracellular contents, but not by change in cell wall properties.

  10. Immunolocalization of solanaceous SUT1 proteins in companion cells and xylem parenchyma: new perspectives for phloem loading and transport.

    PubMed

    Schmitt, Bianca; Stadler, Ruth; Sauer, Norbert

    2008-09-01

    Leaf sucrose (Suc) transporters are essential for phloem loading and long-distance partitioning of assimilates in plants that load their phloem from the apoplast. Suc loading into the phloem is indispensable for the generation of the osmotic potential difference that drives phloem bulk flow and is central for the long-distance movement of phloem sap compounds, including hormones and signaling molecules. In previous analyses, solanaceous SUT1 Suc transporters from tobacco (Nicotiana tabacum), potato (Solanum tuberosum), and tomato (Solanum lycopersicum) were immunolocalized in plasma membranes of enucleate sieve elements. Here, we present data that identify solanaceous SUT1 proteins with high specificity in phloem companion cells. Moreover, comparisons of SUT1 localization in the abaxial and adaxial phloem revealed higher levels of SUT1 protein in the abaxial phloem of all three solanaceous species, suggesting different physiological roles for these two types of phloem. Finally, SUT1 proteins were identified in files of xylem parenchyma cells, mainly in the bicollateral veins. Together, our data provide new insight into the role of SUT1 proteins in solanaceous species.

  11. Interleukin-1beta, -6, -12 and tumor necrosis factor-alpha expression in brains of dogs with canine distemper virus infection.

    PubMed

    Gröne, A; Alldinger, S; Baumgärtner, W

    2000-10-02

    Canine distemper virus infection in dogs is commonly associated with demyelinating central nervous system lesions. Investigations on viral protein expression by studying mRNA and protein distribution together with the characterization of CD4 and CD8 inflammatory cells and MHC class II up-regulation revealed a biphasic disease process. To further investigate the cellular interactions in the different plaque types the cerebella of 14 dogs with confirmed distemper infection were investigated for expression of interleukin (IL)-1beta, -6, -12 and tumor necrosis factor-alpha (TNF) by immunohistochemistry using rabbit polyclonal anti-cytokine antibodies. T-cells and astrocytes were identified with rabbit anti CD3- and GFAP-monoclonal and polyclonal antibodies, respectively; and microglia/macrophages were characterized by their ability to bind lectin from Bandeiraea simplicifolia (BS-1). To further name the cytokine expressing cells immunoenzymatic double staining using DAB and New Fuchsin was performed. White matter lesions were classified according to histopathological criteria into acute, subacute and chronic. Canine distemper virus nucleoprotein antigen was demonstrated in nearly all plaques, except in older plaques where virus was not present within the plaque but adjacent to the lesion. IL-1 expression was observed to varying degrees in all types of lesions. Most often IL-1 was present in CD3 and BS-1 positive cells in the brain parenchyma in earlier plaques and comprising perivascular cuffs found in chronic plaques. IL-6 expression was present in all lesions, and followed a similar distribution pattern as IL-1. IL-12 displayed very often a granular extracellular pattern of immunoreactivity, especially in the brain parenchyma, and was found only in individual perivascular cells. TNF staining, predominantly found in astrocytes, was present in lesions of various types; however, staining appeared to be stronger in acute lesions and decreased in chronic plaques. In the

  12. 30 CFR 56.9103 - Clearance on adjacent tracks.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Clearance on adjacent tracks. 56.9103 Section..., Hauling, and Dumping Traffic Safety § 56.9103 Clearance on adjacent tracks. Railcars shall not be left on side tracks unless clearance is provided for traffic on adjacent tracks....

  13. 30 CFR 57.9103 - Clearance on adjacent tracks.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Clearance on adjacent tracks. 57.9103 Section..., Hauling, and Dumping Traffic Safety § 57.9103 Clearance on adjacent tracks. Railcars shall not be left on side tracks unless clearance is provided for traffic on adjacent tracks....

  14. 49 CFR 236.404 - Signals at adjacent control points.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ..., INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Traffic Control Systems Standards § 236.404 Signals at adjacent control points. Signals at adjacent controlled... 49 Transportation 4 2011-10-01 2011-10-01 false Signals at adjacent control points....

  15. 49 CFR 236.404 - Signals at adjacent control points.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Traffic Control Systems Standards § 236.404 Signals at adjacent control points. Signals at adjacent controlled... 49 Transportation 4 2010-10-01 2010-10-01 false Signals at adjacent control points....

  16. 33 CFR 80.1395 - Puget Sound and adjacent waters.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Puget Sound and adjacent waters... INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Thirteenth District § 80.1395 Puget Sound and adjacent waters. The 72 COLREGS shall apply on all waters of Puget Sound and adjacent waters, including Lake...

  17. 33 CFR 80.1395 - Puget Sound and adjacent waters.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Puget Sound and adjacent waters... INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Thirteenth District § 80.1395 Puget Sound and adjacent waters. The 72 COLREGS shall apply on all waters of Puget Sound and adjacent waters, including Lake...

  18. 33 CFR 80.1395 - Puget Sound and adjacent waters.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Puget Sound and adjacent waters... INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Thirteenth District § 80.1395 Puget Sound and adjacent waters. The 72 COLREGS shall apply on all waters of Puget Sound and adjacent waters, including Lake...

  19. 33 CFR 80.1395 - Puget Sound and adjacent waters.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Puget Sound and adjacent waters... INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Thirteenth District § 80.1395 Puget Sound and adjacent waters. The 72 COLREGS shall apply on all waters of Puget Sound and adjacent waters, including Lake...

  20. 33 CFR 80.1395 - Puget Sound and adjacent waters.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Puget Sound and adjacent waters... INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Thirteenth District § 80.1395 Puget Sound and adjacent waters. The 72 COLREGS shall apply on all waters of Puget Sound and adjacent waters, including Lake...

  1. Plasmonics-enhanced and optically modulated delivery of gold nanostars into brain tumor.

    PubMed

    Yuan, Hsiangkuo; Wilson, Christy M; Xia, Jun; Doyle, Sarah L; Li, Shuqin; Fales, Andrew M; Liu, Yang; Ozaki, Ema; Mulfaul, Kelly; Hanna, Gabi; Palmer, Gregory M; Wang, Lihong V; Grant, Gerald A; Vo-Dinh, Tuan

    2014-04-21

    Plasmonics-active gold nanostars exhibiting strong imaging contrast and efficient photothermal transduction were synthesized for a novel pulsed laser-modulated plasmonics-enhanced brain tumor microvascular permeabilization. We demonstrate a selective, optically modulated delivery of nanoprobes into the tumor parenchyma with minimal off-target distribution.

  2. Plasmonics-enhanced and optically modulated delivery of gold nanostars into brain tumor

    PubMed Central

    Yuan, Hsiangkuo; Wilson, Christy M.; Xia, Jun; Doyle, Sarah L.; Li, Shuqin; Fales, Andrew M; Liu, Yang; Ozaki, Ema; Mulfaul, Kelly; Hanna, Gabi; Palmer, Gregory M.; Wang, Lihong V.; Grant, Gerald A.

    2014-01-01

    Plasmonics-active gold nanostars exhibiting strong imaging contrast and efficient photothermal transduction were synthesized for a novel pulsed laser-modulated plasmonics-enhanced brain tumor microvascular permeabilization. We demonstrate a selective, optically modulated delivery of nanoprobes into the tumor parenchyma with minimal off-target distribution. PMID:24619405

  3. The excessively small ventricle on computed axial tomography of the brain.

    PubMed

    Hahn, F J; Schapiro, R L

    1976-01-01

    Computed axial tomography has made it possible to observe excessively small ventricles in a variety of disorders of the CNS. This finding is presumably due to non-specific and diffuse swelling of brain parenchyma, and is illustrated in cases of trauma, neoplasm, encephalitis, pseudotumor cerebri, metabolic disorder, and probable dilantin effect. It is likely that other causes will be encountered in the future.

  4. Seismicity in Azerbaijan and Adjacent Caspian Sea

    SciTech Connect

    Panahi, Behrouz M.

    2006-03-23

    So far no general view on the geodynamic evolution of the Black Sea to the Caspian Sea region is elaborated. This is associated with the geological and structural complexities of the region revealed by geophysical, geochemical, petrologic, structural, and other studies. A clash of opinions on geodynamic conditions of the Caucasus region, sometimes mutually exclusive, can be explained by a simplified interpretation of the seismic data. In this paper I analyze available data on earthquake occurrences in Azerbaijan and the adjacent Caspian Sea region. The results of the analysis of macroseismic and instrumental data, seismic regime, and earthquake reoccurrence indicate that a level of seismicity in the region is moderate, and seismic event are concentrated in the shallow part of the lithosphere. Seismicity is mostly intra-plate, and spatial distribution of earthquake epicenters does not correlate with the plate boundaries.

  5. CT brain findings in a patient with elevated brain cesium levels.

    PubMed

    Khangure, Simon R; Williams, Eric S; Welman, Christopher J

    2013-12-01

    We describe the CT findings in the brain of a woman with pathologically proven elevated levels of blood and tissue cesium. The 42-year-old woman had been receiving cesium chloride as a non-mainstream treatment for metastatic breast carcinoma. She presented to hospital following a seizure, and died 48 hours after admission. A brain CT performed on hospital admission showed a diffuse increase in attenuation of brain parenchyma. Autopsy revealed elevated levels of cesium in blood and solid organs including the brain. We hypothesize that the imaging findings are attributable to the abnormally elevated level of brain cesium at the time of the CT scan. To our knowledge, this is the first reported case of this imaging finding.

  6. A particle-based model to simulate the micromechanics of single-plant parenchyma cells and aggregates

    NASA Astrophysics Data System (ADS)

    Van Liedekerke, P.; Ghysels, P.; Tijskens, E.; Samaey, G.; Smeedts, B.; Roose, D.; Ramon, H.

    2010-06-01

    This paper is concerned with addressing how plant tissue mechanics is related to the micromechanics of cells. To this end, we propose a mesh-free particle method to simulate the mechanics of both individual plant cells (parenchyma) and cell aggregates in response to external stresses. The model considers two important features in the plant cell: (1) the cell protoplasm, the interior liquid phase inducing hydrodynamic phenomena, and (2) the cell wall material, a viscoelastic solid material that contains the protoplasm. In this particle framework, the cell fluid is modeled by smoothed particle hydrodynamics (SPH), a mesh-free method typically used to address problems with gas and fluid dynamics. In the solid phase (cell wall) on the other hand, the particles are connected by pairwise interactions holding them together and preventing the fluid to penetrate the cell wall. The cell wall hydraulic conductivity (permeability) is built in as well through the SPH formulation. Although this model is also meant to be able to deal with dynamic and even violent situations (leading to cell wall rupture or cell-cell debonding), we have concentrated on quasi-static conditions. The results of single-cell compression simulations show that the conclusions found by analytical models and experiments can be reproduced at least qualitatively. Relaxation tests revealed that plant cells have short relaxation times (1 µs-10 µs) compared to mammalian cells. Simulations performed on cell aggregates indicated an influence of the cellular organization to the tissue response, as was also observed in experiments done on tissues with a similar structure.

  7. Deep supercooling xylem parenchyma cells of katsura tree (Cercidiphyllum japonicum) contain flavonol glycosides exhibiting high anti-ice nucleation activity.

    PubMed

    Kasuga, Jun; Hashidoko, Yasuyuki; Nishioka, Atsushi; Yoshiba, Megumi; Arakawa, Keita; Fujikawa, Seizo

    2008-09-01

    Xylem parenchyma cells (XPCs) of boreal hardwood species adapt to sub-freezing temperatures by deep supercooling to maintain a liquid state of intracellular water near -40 degrees C. Our previous study found that crude xylem extracts from such tree species exhibited anti-ice nucleation activity to promote supercooling of water. In the present study, thus, we attempted to identify the causative substances of supercooling. Crude xylem extracts from katsura tree (Cercidiphyllum japonicum), of which XPCs exhibited deep supercooling to -40 degrees C, were prepared by methanol extraction. The crude extracts were purified by liquid-liquid extraction and then by silica gel column chromatography. Although all the fractions obtained after each purification step exhibited some levels of anti-ice nucleation activity, only the most active fraction was retained to proceed to the subsequent level of purification. High-performance liquid chromatography (HPLC) analysis of a fraction with the highest level of activity revealed four peaks with high levels of anti-ice nucleation activity in the range of 2.8-9.0 degrees C. Ultraviolet (UV), mass and nuclear magnetic resonance (NMR) spectra revealed that these four peaks corresponded to quercetin-3-O-beta-glucoside (Q3G), kaempferol-7-O-beta-glucoside (K7G), 8-methoxykaempferol-3-O-beta-glucoside (8MK3G) and kaempferol-3-O-beta-glucoside (K3G). Microscopic observations confirmed the presence of flavonoids in cytoplasms of XPCs. These results suggest that diverse kinds of anti-ice nucleation substances, including flavonol glycosides, may have important roles in deep supercooling of XPCs.

  8. A particle-based model to simulate the micromechanics of single-plant parenchyma cells and aggregates.

    PubMed

    Van Liedekerke, P; Ghysels, P; Tijskens, E; Samaey, G; Smeedts, B; Roose, D; Ramon, H

    2010-05-26

    This paper is concerned with addressing how plant tissue mechanics is related to the micromechanics of cells. To this end, we propose a mesh-free particle method to simulate the mechanics of both individual plant cells (parenchyma) and cell aggregates in response to external stresses. The model considers two important features in the plant cell: (1) the cell protoplasm, the interior liquid phase inducing hydrodynamic phenomena, and (2) the cell wall material, a viscoelastic solid material that contains the protoplasm. In this particle framework, the cell fluid is modeled by smoothed particle hydrodynamics (SPH), a mesh-free method typically used to address problems with gas and fluid dynamics. In the solid phase (cell wall) on the other hand, the particles are connected by pairwise interactions holding them together and preventing the fluid to penetrate the cell wall. The cell wall hydraulic conductivity (permeability) is built in as well through the SPH formulation. Although this model is also meant to be able to deal with dynamic and even violent situations (leading to cell wall rupture or cell-cell debonding), we have concentrated on quasi-static conditions. The results of single-cell compression simulations show that the conclusions found by analytical models and experiments can be reproduced at least qualitatively. Relaxation tests revealed that plant cells have short relaxation times (1 micros-10 micros) compared to mammalian cells. Simulations performed on cell aggregates indicated an influence of the cellular organization to the tissue response, as was also observed in experiments done on tissues with a similar structure.

  9. A mathematical model of blood, cerebrospinal fluid and brain dynamics.

    PubMed

    Linninger, Andreas A; Xenos, Michalis; Sweetman, Brian; Ponkshe, Sukruti; Guo, Xiaodong; Penn, Richard

    2009-12-01

    Using first principles of fluid and solid mechanics a comprehensive model of human intracranial dynamics is proposed. Blood, cerebrospinal fluid (CSF) and brain parenchyma as well as the spinal canal are included. The compartmental model predicts intracranial pressure gradients, blood and CSF flows and displacements in normal and pathological conditions like communicating hydrocephalus. The system of differential equations of first principles conservation balances is discretized and solved numerically. Fluid-solid interactions of the brain parenchyma with cerebral blood and CSF are calculated. The model provides the transitions from normal dynamics to the diseased state during the onset of communicating hydrocephalus. Predicted results were compared with physiological data from Cine phase-contrast magnetic resonance imaging to verify the dynamic model. Bolus injections into the CSF are simulated in the model and found to agree with clinical measurements.

  10. Convection-enhanced delivery of liposomes to primate brain.

    PubMed

    Krauze, Michal T; Forsayeth, John; Yin, Dali; Bankiewicz, Krystof S

    2009-01-01

    Direct delivery of therapeutic agents to the human central nervous system remains an inadequately studied field. Our group has extensively studied and refined a powerful method for distributing various macromolecules and nanoparticles into the parenchyma by means of a procedure called convection-enhanced delivery (CED). First, we developed an improved design of infusion cannula that greatly decreased the likelihood of reflux of infusate up the outside of the cannula. Second, we began to use liposomes loaded with the MRI contrast reagent, Gadoteridol (Gd), to track infusions into brain parenchyma in real time. This innovation generated a wealth of quantitative and qualitative data that in turn drove further improvements in CED. In this chapter, we review many of the recently devised methods needed to ensure controlled distribution of therapeutic agents in the brain.

  11. Rice sucrose transporter1 (OsSUT1) up-regulation in xylem parenchyma is caused by aphid feeding on rice leaf blade vascular bundles.

    PubMed

    Ibraheem, O; Botha, C E J; Bradley, G; Dealtry, G; Roux, S

    2014-07-01

    The role of the sucrose transporter OsSUT1 in assimilate retrieval via the xylem, as a result of damage to and leakage from punctured phloem was examined after rusty plum aphid (Hysteroneura setariae, Thomas) infestation on leaves from 3-week-old rice (Oryza sativa L. cv Nipponbare) plants. Leaves were examined over a 1- to 10-day infestation time course, using a combination of gene expression and β-glucuronidase (GUS) reporter gene analyses. qPCR and Western blot analyses revealed differential expression of OsSUT1 during aphid infestation. Wide-field fluorescence microscopy was used to confirm the expression of OsSUT1-promoter::GUS reporter gene in vascular parenchyma associated with xylem elements, as well as in companion cells associated with phloem sieve tubes of large, intermediate and small vascular bundles within the leaf blade, in regions where the aphids had settled and were feeding. Of great interest was up-regulation of OsSUT1 expression associated with the xylem parenchyma cells, abutting the metaxylem vessels, which confirmed that OsSUT1 was not only involved in loading of sugars into the phloem under normal physiological conditions, but was apparently involved in the retrieval of sucrose leaked into the xylem conduits, which occurred as a direct result of aphid feeding, probing and puncturing of vascular bundles. The up-regulation of OsSUT1 in xylem vascular parenchyma thus provides evidence in support of the location within the xylem parenchyma cells of an efficient mechanism to ensure sucrose recovery after loss to the apoplast (xylem) after aphid-related feeding damage and its transfer back to the symplast (phloem) in O. sativa leaves.

  12. [Dynamic expression profile of HBsAg according to hepatic parenchyma cells' volume at different liver fibrosis stages in the immune clearance phase].

    PubMed

    Wu, Zhe-bin; Cao, Hong; Liu, Ting; Wu, Ze-qian; Ke, Wei-min; Gao, Zhi-liang

    2012-10-01

    The aim of this study was to determine the dynamic expression profile of hepatitis B surface antigen (HBsAg) according to hepatic parenchyma cells' volume at different stages of liver fibrosis during the immune clearance phase. Eighty-nine patients with HBeAg-positive chronic hepatitis B (CHB) in the immune clearance stage were recruited for study. Each patient's serum HBsAg levels were detected by electrochemiluminescence. The serum HBsAg levels were apportioned according to hepatic parenchyma cells' volume at liver fibrosis stages 1, 2, 3, and 4 and compared by ANOVA. The unapportioned serum HBsAg levels (IU/mL) at liver fibrosis stages 1 (227.2+/-237.7), 2 (211.0+/-131.4), 3(300.1+/-144.6), and 4 (278.7+/-148.8) were not significantly different (all comparisons, P range: 0.061 to 0.759). However, when the serum HBsAg levels were apportioned by the same hepatic parenchyma cells' volume at liver fibrosis stages 1 (343.9+/-359.8), 2 (336.4+/-209.5), 3 (508.7+/-245.1), and 4 (525.2+/-274.8), the levels were significantly different (all comparisons, F = 3.045 and P = 0.033; stage 1 vs. 3, P = 0.041; stage 1 vs. 4, P = 0.046; stage 2 vs. 3, P = 0.028; stage 2 vs. 4, P = 0.034). During the immune clearance phase of chronic hepatitis B, increased HBsAg expression is associated with increased hepatic parenchyma cells' volume and progressive liver fibrosis stage.

  13. Heterogeneous echogenicity of the thyroid parenchyma does not influence the detection of multi-focality in papillary thyroid carcinoma on preoperative ultrasound staging.

    PubMed

    Herh, Sun Jin; Kim, Eun-Kyung; Sung, Ji Min; Yoon, Jung Hyun; Moon, Hee Jung; Kwak, Jin Young

    2014-05-01

    Heterogeneous echogenicity and micro-nodulations of diffuse thyroid disease on ultrasonography (US) might influence the diagnostic performance of pre-operative US staging, especially the detection of multi-focality. This study was designed to determine whether heterogeneous echogenicity of the thyroid parenchyma influences the diagnostic performance of US in the detection of multi-focality in papillary thyroid carcinoma. Between December 2010 and April 2011, 811 patients underwent pre-operative staging US for papillary thyroid carcinoma and surgery. Twelve radiologists performed the pre-operative US for T and N staging. Underlying parenchymal echogenicity and unilateral and bilateral multi-focality of the thyroid nodules were also evaluated. Patients were divided into two groups on the basis of the underlying echogenicity of the thyroid gland. To evaluate the diagnostic accuracy of US with respect to underlying echogenicity, the sensitivity, specificity, positive predictive value, negative predictive value and accuracy were calculated and compared between the two groups. Among the 811 patients included, US revealed underlying heterogeneous echogenicity of the thyroid parenchyma in 204 (25.2%) and underlying homogeneous echogenicity of the thyroid parenchyma in 607 (74.8%). There were no significant differences between the two groups in the diagnostic performance of pre-operative staging US in predicting unilateral multi-focality and bilaterality. Underlying heterogeneous echogenicity in a thyroid gland with Hashimoto's thyroiditis does not significantly influence the detection of multi-focality in papillary thyroid cancer on pre-operative US staging.

  14. Distinct roles for matrix metalloproteinase-2 and alpha4 integrin in autoimmune T cell extravasation and residency in brain parenchyma during experimental autoimmune encephalomyelitis.

    PubMed

    Graesser, D; Mahooti, S; Madri, J A

    2000-09-22

    Expression of alpha4 integrin by auto-reactive T cells is critical for their ability to induce EAE, an autoimmune disease of the central nervous system in mice, used as a model to study human multiple sclerosis. Having previously identified one role for alpha4 integrin in adhesion-mediated induction of matrix metalloproteinase-2 (MMP-2), an enzyme that degrades the subendothelial basement membrane matrix, we investigated independent roles for MMP-2 and alpha4 integrin during EAE. The data suggest that expression of alpha4 integrin by auto-reactive T cells is important not only in mediating MMP-2 induction to facilitate entry into the CNS, but also plays a role in maintaining residency within the CNS.

  15. Regulation of brain copper homeostasis by the brain barrier systems: Effects of Fe-overload and Fe-deficiency

    SciTech Connect

    Monnot, Andrew D.; Behl, Mamta; Ho, Sanna; Zheng, Wei

    2011-11-15

    Maintaining brain Cu homeostasis is vital for normal brain function. The role of systemic Fe deficiency (FeD) or overload (FeO) due to metabolic diseases or environmental insults in Cu homeostasis in the cerebrospinal fluid (CSF) and brain tissues remains unknown. This study was designed to investigate how blood-brain barrier (BBB) and blood-SCF barrier (BCB) regulated Cu transport and how FeO or FeD altered brain Cu homeostasis. Rats received an Fe-enriched or Fe-depleted diet for 4 weeks. FeD and FeO treatment resulted in a significant increase (+ 55%) and decrease (- 56%) in CSF Cu levels (p < 0.05), respectively; however, neither treatment had any effect on CSF Fe levels. The FeD, but not FeO, led to significant increases in Cu levels in brain parenchyma and the choroid plexus. In situ brain perfusion studies demonstrated that the rate of Cu transport into the brain parenchyma was significantly faster in FeD rats (+ 92%) and significantly slower (- 53%) in FeO rats than in controls. In vitro two chamber Transwell transepithelial transport studies using primary choroidal epithelial cells revealed a predominant efflux of Cu from the CSF to blood compartment by the BCB. Further ventriculo-cisternal perfusion studies showed that Cu clearance by the choroid plexus in FeD animals was significantly greater than control (p < 0.05). Taken together, our results demonstrate that both the BBB and BCB contribute to maintain a stable Cu homeostasis in the brain and CSF. Cu appears to enter the brain primarily via the BBB and is subsequently removed from the CSF by the BCB. FeD has a more profound effect on brain Cu levels than FeO. FeD increases Cu transport at the brain barriers and prompts Cu overload in the CNS. The BCB plays a key role in removing the excess Cu from the CSF.

  16. Brain herniation

    MedlinePlus

    ... herniation; Uncal herniation; Subfalcine herniation; Tonsillar herniation; Herniation - brain ... Brain herniation occurs when something inside the skull produces pressure that moves brain tissues. This is most ...

  17. Non-invasive delivery of stealth, brain-penetrating nanoparticles across the blood-brain barrier using MRI-guided focused ultrasound.

    PubMed

    Nance, Elizabeth; Timbie, Kelsie; Miller, G Wilson; Song, Ji; Louttit, Cameron; Klibanov, Alexander L; Shih, Ting-Yu; Swaminathan, Ganesh; Tamargo, Rafael J; Woodworth, Graeme F; Hanes, Justin; Price, Richard J

    2014-09-10

    The blood-brain barrier (BBB) presents a significant obstacle for the treatment of many central nervous system (CNS) disorders, including invasive brain tumors, Alzheimer's, Parkinson's and stroke. Therapeutics must be capable of bypassing the BBB and also penetrate the brain parenchyma to achieve a desired effect within the brain. In this study, we test the unique combination of a non-invasive approach to BBB permeabilization with a therapeutically relevant polymeric nanoparticle platform capable of rapidly penetrating within the brain microenvironment. MR-guided focused ultrasound (FUS) with intravascular microbubbles (MBs) is able to locally and reversibly disrupt the BBB with submillimeter spatial accuracy. Densely poly(ethylene-co-glycol) (PEG) coated, brain-penetrating nanoparticles (BPNs) are long-circulating and diffuse 10-fold slower in normal rat brain tissue compared to diffusion in water. Following intravenous administration of model and biodegradable BPNs in normal healthy rats, we demonstrate safe, pressure-dependent delivery of 60nm BPNs to the brain parenchyma in regions where the BBB is disrupted by FUS and MBs. Delivery of BPNs with MR-guided FUS has the potential to improve efficacy of treatments for many CNS diseases, while reducing systemic side effects by providing sustained, well-dispersed drug delivery into select regions of the brain.

  18. Learning Non-Adjacent Regularities at Age 0 ; 7

    ERIC Educational Resources Information Center

    Gervain, Judit; Werker, Janet F.

    2013-01-01

    One important mechanism suggested to underlie the acquisition of grammar is rule learning. Indeed, infants aged 0 ; 7 are able to learn rules based on simple identity relations (adjacent repetitions, ABB: "wo fe fe" and non-adjacent repetitions, ABA: "wo fe wo", respectively; Marcus et al., 1999). One unexplored issue is…

  19. View of north side from exterior stairs of adjacent building, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of north side from exterior stairs of adjacent building, bottom cut off by fringed buildings, view facing south-southwest - U.S. Naval Base, Pearl Harbor, Industrial X-Ray Building, Off Sixth Street, adjacent to and south of Facility No. 11, Pearl City, Honolulu County, HI

  20. A Study of the Pronunciation of Words Containing Adjacent Vowels.

    ERIC Educational Resources Information Center

    Greif, Ivo P.

    To determine the usefulness of the commonly taught phonics rule, "only pronounce the first vowel in words that contain adjacent vowels" (the VV rule, with the first "v" pronounced with the long vowel sound), two new studies applied it to words with adjacent vowels in several lists and dictionaries. The first study analyzed words containing…

  1. 47 CFR 90.221 - Adjacent channel power limits.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 5 2013-10-01 2013-10-01 false Adjacent channel power limits. 90.221 Section 90.221 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES General Technical Standards § 90.221 Adjacent channel...

  2. 47 CFR 90.221 - Adjacent channel power limits.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 5 2014-10-01 2014-10-01 false Adjacent channel power limits. 90.221 Section 90.221 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES General Technical Standards § 90.221 Adjacent channel...

  3. 30 CFR 57.14109 - Unguarded conveyors with adjacent travelways.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Unguarded conveyors with adjacent travelways... conveyors with adjacent travelways. Unguarded conveyors next to travelways shall be equipped with— (a) Emergency stop devices which are located so that a person falling on or against the conveyor can...

  4. 30 CFR 56.14109 - Unguarded conveyors with adjacent travelways.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Unguarded conveyors with adjacent travelways... MINES Machinery and Equipment Safety Devices and Maintenance Requirements § 56.14109 Unguarded conveyors with adjacent travelways. Unguarded conveyors next to the travelways shall be equipped with—...

  5. 30 CFR 56.14109 - Unguarded conveyors with adjacent travelways.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Unguarded conveyors with adjacent travelways... MINES Machinery and Equipment Safety Devices and Maintenance Requirements § 56.14109 Unguarded conveyors with adjacent travelways. Unguarded conveyors next to the travelways shall be equipped with—...

  6. 30 CFR 57.14109 - Unguarded conveyors with adjacent travelways.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Unguarded conveyors with adjacent travelways... conveyors with adjacent travelways. Unguarded conveyors next to travelways shall be equipped with— (a) Emergency stop devices which are located so that a person falling on or against the conveyor can...

  7. 30 CFR 56.14109 - Unguarded conveyors with adjacent travelways.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Unguarded conveyors with adjacent travelways... MINES Machinery and Equipment Safety Devices and Maintenance Requirements § 56.14109 Unguarded conveyors with adjacent travelways. Unguarded conveyors next to the travelways shall be equipped with—...

  8. 30 CFR 57.14109 - Unguarded conveyors with adjacent travelways.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Unguarded conveyors with adjacent travelways... conveyors with adjacent travelways. Unguarded conveyors next to travelways shall be equipped with— (a) Emergency stop devices which are located so that a person falling on or against the conveyor can...

  9. 30 CFR 56.14109 - Unguarded conveyors with adjacent travelways.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Unguarded conveyors with adjacent travelways... MINES Machinery and Equipment Safety Devices and Maintenance Requirements § 56.14109 Unguarded conveyors with adjacent travelways. Unguarded conveyors next to the travelways shall be equipped with—...

  10. 30 CFR 56.14109 - Unguarded conveyors with adjacent travelways.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Unguarded conveyors with adjacent travelways... MINES Machinery and Equipment Safety Devices and Maintenance Requirements § 56.14109 Unguarded conveyors with adjacent travelways. Unguarded conveyors next to the travelways shall be equipped with—...

  11. 30 CFR 57.14109 - Unguarded conveyors with adjacent travelways.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Unguarded conveyors with adjacent travelways... conveyors with adjacent travelways. Unguarded conveyors next to travelways shall be equipped with— (a) Emergency stop devices which are located so that a person falling on or against the conveyor can...

  12. 30 CFR 57.14109 - Unguarded conveyors with adjacent travelways.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Unguarded conveyors with adjacent travelways... conveyors with adjacent travelways. Unguarded conveyors next to travelways shall be equipped with— (a) Emergency stop devices which are located so that a person falling on or against the conveyor can...

  13. Mortality of passerines adjacent to a North Carolina corn field treated with granular carbofuran.

    USGS Publications Warehouse

    Augspurger, Tom; Smith, Milton R.; Meteyer, Carol U.; Converse, Kathryn A.

    1996-01-01

    Red-winged blackbirds (Agelaius phoeniceus) were collected during an epizootic in southeastern North Carolina (USA). Activity of brain cholinesterase (ChE) was inhibited by 14 to 48% in three of five specimens, and returned to normal levels after incubation. Gastrointestinal tracts were analyzed for 30 anti-ChE agents. Carbofuran, the only compound detected, was present in all specimens at levels from 5.44 to 72.7 μg/g wet weight. Application of granular carbofuran in an adjacent corn field, results of necropsy examinations, and chemical analyses are consistent with a diagnosis of carbofuran poisoning in these specimens.

  14. Image segmentation by EM-based adaptive pulse coupled neural networks in brain magnetic resonance imaging.

    PubMed

    Fu, J C; Chen, C C; Chai, J W; Wong, S T C; Li, I C

    2010-06-01

    We propose an automatic hybrid image segmentation model that integrates the statistical expectation maximization (EM) model and the spatial pulse coupled neural network (PCNN) for brain magnetic resonance imaging (MRI) segmentation. In addition, an adaptive mechanism is developed to fine tune the PCNN parameters. The EM model serves two functions: evaluation of the PCNN image segmentation and adaptive adjustment of the PCNN parameters for optimal segmentation. To evaluate the performance of the adaptive EM-PCNN, we use it to segment MR brain image into gray matter (GM), white matter (WM) and cerebrospinal fluid (CSF). The performance of the adaptive EM-PCNN is compared with that of the non-adaptive EM-PCNN, EM, and Bias Corrected Fuzzy C-Means (BCFCM) algorithms. The result is four sets of boundaries for the GM and the brain parenchyma (GM+WM), the two regions of most interest in medical research and clinical applications. Each set of boundaries is compared with the golden standard to evaluate the segmentation performance. The adaptive EM-PCNN significantly outperforms the non-adaptive EM-PCNN, EM, and BCFCM algorithms in gray mater segmentation. In brain parenchyma segmentation, the adaptive EM-PCNN significantly outperforms the BCFCM only. However, the adaptive EM-PCNN is better than the non-adaptive EM-PCNN and EM on average. We conclude that of the three approaches, the adaptive EM-PCNN yields the best results for gray matter and brain parenchyma segmentation.

  15. Extravasation of blood-borne immunoglobulin G through blood-brain barrier during adrenaline-induced transient hypertension in the rat.

    PubMed

    Kuang, Fang; Wang, Bai-Ren; Zhang, Ping; Fei, Ling-Ling; Jia, Yi; Duan, Xiao-Li; Wang, Xi; Xu, Zhen; Li, Gai-Li; Jiao, Xi-Ying; Ju, Gong

    2004-06-01

    The effect of transient hypertension on blood-brain barrier (BBB) permeability, particularly on extravasation of immunoglobulin G (IgG), has not been fully understood. In the present experiment, we investigated the time course of endogenous albumin and IgG extravasation through BBB and the localization of extravasated IgG in brain parenchyma during adrenaline(AD)-induced transient hypertension in the rat by using Evans blue fluorescence, immunohistochemistry, and Western blot. The results showed that a bolus injection of AD (10 microg/kg) induced a transient elevation of arterial pressure lasting about 1 min. The endogenous albumin and IgG entered the brain parenchyma via BBB only when hypertension occurred. Electron microscopically, the IgG-like immunoreactivities were predominantly seen in the cytoplasm of endothelia of capillaries, pericytes, extracellular space of parenchyma, and the cytoplasm of glial cells. The results suggest that circulating IgG or antibodies might contact the structures of brain parenchyma through passage of BBB when its permeability is temporally changed by transient hypertension. This phenomenon implies a possible mechanism of pathogenesis for immune-mediated diseases in the brain.

  16. Magnetic resonance elastography of the lung parenchyma in an in situ porcine model with a noninvasive mechanical driver: correlation of shear stiffness with trans-respiratory system pressures.

    PubMed

    Mariappan, Yogesh K; Kolipaka, Arunark; Manduca, Armando; Hubmayr, Rolf D; Ehman, Richard L; Araoz, Philip; McGee, Kiaran P

    2012-01-01

    Quantification of the mechanical properties of lung parenchyma is an active field of research due to the association of this metric with normal function, disease initiation and progression. A phase contrast MRI-based elasticity imaging technique known as magnetic resonance elastography is being investigated as a method for measuring the shear stiffness of lung parenchyma. Previous experiments performed with small animals using invasive drivers in direct contact with the lungs have indicated that the quantification of lung shear modulus with (1) H based magnetic resonance elastography is feasible. This technique has been extended to an in situ porcine model with a noninvasive mechanical driver placed on the chest wall. This approach was tested to measure the change in parenchymal stiffness as a function of airway opening pressure (P(ao) ) in 10 adult pigs. In all animals, shear stiffness was successfully quantified at four different P(ao) values. Mean (±STD error of mean) pulmonary parenchyma density corrected stiffness values were calculated to be 1.48 (±0.09), 1.68 (±0.10), 2.05 (±0.13), and 2.23 (±0.17) kPa for P(ao) values of 5, 10, 15, and 20 cm H2O, respectively. Shear stiffness increased with increasing P(ao) , in agreement with the literature. It is concluded that in an in situ porcine lung shear stiffness can be quantitated with (1) H magnetic resonance elastography using a noninvasive mechanical driver and that it is feasible to measure the change in shear stiffness due to change in P(ao) .

  17. Temporary Arterial Embolization of Liver Parenchyma with Degradable Starch Microspheres (EmboCept{sup ®}S) in a Swine Model

    SciTech Connect

    Pieper, Claus C. Meyer, Carsten; Vollmar, Brigitte; Hauenstein, Karlheinz; Schild, Hans H.; Wilhelm, Kai E.

    2015-04-15

    BackgroundThis study aimed to evaluate the embolic properties, time to reperfusion, and histologic changes in temporary embolization of liver tissue with degradable starch microspheres (DSM) in a swine model.MethodsIn four adult minipigs, DSMs were injected into the right or left hepatic artery on the lobar level until complete stasis of the blood flow was detectable angiographically. The time required to complete angiographically determined reperfusion was noted. The animals were killed 3 h after complete reperfusion, and samples were taken from the liver. Histologic examinations of the embolized liver parenchyma and untreated tissue were performed.ResultsHepatic arterial embolization using DSMs was technically successful in all cases, with complete blood flow stasis shown by control angiography. A single vial of DSMs (450 mg/7.5 ml) was sufficient to embolize a whole liver lobe in all cases. Angiography showed complete reconstitution of hepatic arterial perfusion after a mean time to reperfusion of 32 ± 6.1 min (range, 26–39 min). Hematoxylin and eosin staining showed no histologically detectable differences between untreated tissue and parenchyma embolized with DSMs except for mild sinusoidal congestion in one case. Indirect in situ DNA nick end labeling staining (TUNEL) showed only single positive hepatocytes, indicating apoptosis.ConclusionTemporary embolization of the hepatic artery using DSMs is feasible with complete reperfusion after 30 min in pigs. Even after complete arterial blood flow stasis, no extensive tissue damage to the embolized liver parenchyma was observed at histologic examinations in this short-term study.

  18. The Parenchyma of Secondary Xylem and Its Critical Role in Tree Defense against Fungal Decay in Relation to the CODIT Model.

    PubMed

    Morris, Hugh; Brodersen, Craig; Schwarze, Francis W M R; Jansen, Steven

    2016-01-01

    This review examines the roles that ray and axial parenchyma (RAP) plays against fungal pathogens in the secondary xylem of wood within the context of the CODIT model (Compartmentalization of Decay in Trees), a defense concept first conceived in the early 1970s by Alex Shigo. This model, simplistic in its design, shows how a large woody perennial is highly compartmented. Anatomical divisions in place at the time of infection or damage, (physical defense) alongside the 'active' response by the RAP during and after wounding work together in forming boundaries that function to restrict air or decay spread. The living parenchyma cells play a critical role in all of the four walls (differing anatomical constructs) that the model comprises. To understand how living cells in each of the walls of CODIT cooperate, we must have a clear vision of their complex interconnectivity from a three-dimensional perspective, along with knowledge of the huge variation in ray parenchyma (RP) and axial parenchyma (AP) abundance and patterns. Crucial patterns for defense encompass the symplastic continuum between both RP and AP and the dead tissues, with the latter including the vessel elements, libriform fibers, and imperforate tracheary elements (i.e., vasicentric and vascular tracheids). Also, the heartwood, a chemically altered antimicrobial non-living substance that forms the core of many trees, provides an integral part of the defense system. In the heartwood, dead RAP can play an important role in defense, depending on the genetic constitution of the species. Considering the array of functions that RAP are associated with, from capacitance, through to storage, and long-distance water transport, deciding how their role in defense fits into this suite of functions is a challenge for plant scientists, and likely depends on a range of factors. Here, we explore the important role of RAP in defense against fungal pathogens and the trade-offs involved from a viewpoint for structure

  19. The Parenchyma of Secondary Xylem and Its Critical Role in Tree Defense against Fungal Decay in Relation to the CODIT Model

    PubMed Central

    Morris, Hugh; Brodersen, Craig; Schwarze, Francis W. M. R.; Jansen, Steven

    2016-01-01

    This review examines the roles that ray and axial parenchyma (RAP) plays against fungal pathogens in the secondary xylem of wood within the context of the CODIT model (Compartmentalization of Decay in Trees), a defense concept first conceived in the early 1970s by Alex Shigo. This model, simplistic in its design, shows how a large woody perennial is highly compartmented. Anatomical divisions in place at the time of infection or damage, (physical defense) alongside the ‘active’ response by the RAP during and after wounding work together in forming boundaries that function to restrict air or decay spread. The living parenchyma cells play a critical role in all of the four walls (differing anatomical constructs) that the model comprises. To understand how living cells in each of the walls of CODIT cooperate, we must have a clear vision of their complex interconnectivity from a three-dimensional perspective, along with knowledge of the huge variation in ray parenchyma (RP) and axial parenchyma (AP) abundance and patterns. Crucial patterns for defense encompass the symplastic continuum between both RP and AP and the dead tissues, with the latter including the vessel elements, libriform fibers, and imperforate tracheary elements (i.e., vasicentric and vascular tracheids). Also, the heartwood, a chemically altered antimicrobial non-living substance that forms the core of many trees, provides an integral part of the defense system. In the heartwood, dead RAP can play an important role in defense, depending on the genetic constitution of the species. Considering the array of functions that RAP are associated with, from capacitance, through to storage, and long-distance water transport, deciding how their role in defense fits into this suite of functions is a challenge for plant scientists, and likely depends on a range of factors. Here, we explore the important role of RAP in defense against fungal pathogens and the trade-offs involved from a viewpoint for structure

  20. Usefulness of basic renal function tests in decision-making in children with loss of renal parenchyma and/or dilation of the urinary tract.

    PubMed

    García Nieto, Víctor M; Luis Yanes, Maria Isabel; Arango Sancho, Pedro; Sotoca Fernandez, Jorge V

    2016-01-01

    Basic renal function tests such as maximum urine osmolality and urinary elimination of albumin and N-acetyl-glucosaminidase often reveal abnormalities in clinical cases involving hyperpressure in the urinary tract or loss of renal parenchyma. However, in all the available algorithms dedicated to the study of children with urinary tract infection or dilation, the benefit of using these functional parameters is not mentioned. In this review, we provide information about the practical usefulness of assessing the basic renal function parameters. From these data, we propose an algorithm that combines morphological and functional parameters to make a reasoned case for voiding cystourethrography.

  1. Electrophysiological approach to determine kinetic parameters of sucrose uptake by single sieve elements or phloem parenchyma cells in intact Vicia faba plants

    PubMed Central

    Hafke, Jens B.; Höll, Sabina-Roxana; Kühn, Christina; van Bel, Aart J. E.

    2013-01-01

    Apart from cut aphid stylets in combination with electrophysiology, no attempts have been made thus far to measure in vivo sucrose-uptake properties of sieve elements. We investigated the kinetics of sucrose uptake by single sieve elements and phloem parenchyma cells in Vicia faba plants. To this end, microelectrodes were inserted into free-lying phloem cells in the main vein of the youngest fully-expanded leaf, half-way along the stem, in the transition zone between the autotrophic and heterotrophic part of the stem, and in the root axis. A top-to-bottom membrane potential gradient of sieve elements was observed along the stem (−130 mV to −110 mV), while the membrane potential of the phloem parenchyma cells was stable (approx. −100 mV). In roots, the membrane potential of sieve elements dropped abruptly to −55 mV. Bathing solutions having various sucrose concentrations were administered and sucrose/H+-induced depolarizations were recorded. Data analysis by non-linear least-square data fittings as well as by linear Eadie–Hofstee (EH) -transformations pointed at biphasic Michaelis–Menten kinetics (2 MM, EH: Km1 1.2–1.8 mM, Km2 6.6–9.0 mM) of sucrose uptake by sieve elements. However, Akaike's Information Criterion (AIC) favored single MM kinetics. Using single MM as the best-fitting model, Km values for sucrose uptake by sieve elements decreased along the plant axis from 1 to 7 mM. For phloem parenchyma cells, higher Km values (EH: Km1 10 mM, Km2 70 mM) as compared to sieve elements were found. In preliminary patch-clamp experiments with sieve-element protoplasts, small sucrose-coupled proton currents (−0.1 to −0.3 pA/pF) were detected in the whole-cell mode. In conclusion (a) Km values for sucrose uptake measured by electrophysiology are similar to those obtained with heterologous systems, (b) electrophysiology provides a useful tool for in situ determination of Km values, (c) As yet, it remains unclear if one or two uptake systems are involved

  2. Electrophysiological approach to determine kinetic parameters of sucrose uptake by single sieve elements or phloem parenchyma cells in intact Vicia faba plants.

    PubMed

    Hafke, Jens B; Höll, Sabina-Roxana; Kühn, Christina; van Bel, Aart J E

    2013-01-01

    Apart from cut aphid stylets in combination with electrophysiology, no attempts have been made thus far to measure in vivo sucrose-uptake properties of sieve elements. We investigated the kinetics of sucrose uptake by single sieve elements and phloem parenchyma cells in Vicia faba plants. To this end, microelectrodes were inserted into free-lying phloem cells in the main vein of the youngest fully-expanded leaf, half-way along the stem, in the transition zone between the autotrophic and heterotrophic part of the stem, and in the root axis. A top-to-bottom membrane potential gradient of sieve elements was observed along the stem (-130 mV to -110 mV), while the membrane potential of the phloem parenchyma cells was stable (approx. -100 mV). In roots, the membrane potential of sieve elements dropped abruptly to -55 mV. Bathing solutions having various sucrose concentrations were administered and sucrose/H(+)-induced depolarizations were recorded. Data analysis by non-linear least-square data fittings as well as by linear Eadie-Hofstee (EH) -transformations pointed at biphasic Michaelis-Menten kinetics (2 MM, EH: K m1 1.2-1.8 mM, K m2 6.6-9.0 mM) of sucrose uptake by sieve elements. However, Akaike's Information Criterion (AIC) favored single MM kinetics. Using single MM as the best-fitting model, K m values for sucrose uptake by sieve elements decreased along the plant axis from 1 to 7 mM. For phloem parenchyma cells, higher K m values (EH: K m1 10 mM, K m2 70 mM) as compared to sieve elements were found. In preliminary patch-clamp experiments with sieve-element protoplasts, small sucrose-coupled proton currents (-0.1 to -0.3 pA/pF) were detected in the whole-cell mode. In conclusion (a) K m values for sucrose uptake measured by electrophysiology are similar to those obtained with heterologous systems, (b) electrophysiology provides a useful tool for in situ determination of K m values, (c) As yet, it remains unclear if one or two uptake systems are involved in sucrose

  3. PIXE analysis of elements in gastric cancer and adjacent mucosa

    NASA Astrophysics Data System (ADS)

    Liu, Qixin; Zhong, Ming; Zhang, Xiaofeng; Yan, Lingnuo; Xu, Yongling; Ye, Simao

    1990-04-01

    The elemental regional distributions in 20 resected human stomach tissues were obtained using PIXE analysis. The samples were pathologically divided into four types: normal, adjacent mucosa A, adjacent mucosa B and cancer. The targets for PIXE analysis were prepared by wet digestion with a pressure bomb system. P, K, Fe, Cu, Zn and Se were measured and statistically analysed. We found significantly higher concentrations of P, K, Cu, Zn and a higher ratio of Cu compared to Zn in cancer tissue as compared with normal tissue, but statistically no significant difference between adjacent mucosa and cancer tissue was found.

  4. Thermoelastic response of thin metal films and their adjacent materials

    SciTech Connect

    Kang, S.; Yoon, Y.; Kim, J.; Kim, W.

    2013-01-14

    A pulsed laser beam applied to a thin metal film is capable of launching an acoustic wave due to thermal expansion. Heat transfer from the thin metal film to adjacent materials can also induce thermal expansion; thus, the properties of these adjacent materials (as well as the thin metal film) should be considered for a complete description of the thermoelastic response. Here, we show that adjacent materials with a small specific heat and large thermal expansion coefficient can generate an enhanced acoustic wave and we demonstrate a three-fold increase in the peak pressure of the generated acoustic wave on substitution of parylene for polydimethylsiloxane.

  5. Massive pneumatic expansion of lymphatic vessel resulting in cystic lesions in the pulmonary parenchyma: a rare case of persistent interstitial pulmonary emphysema in a non-ventilated infant.

    PubMed

    Fujishiro, Jun; Komuro, Hiroaki; Ono, Kentaro; Urita, Yasuhisa; Shinkai, Toko; Minami, Yuko; Kawabata, Yoshinori; Kishimoto, Hiroshi; Masumoto, Kouji

    2012-12-01

    We report the case of 2-week-old female infant with cystic lung disease who presented with mild tachypnea and had no history of mechanical ventilation. Chest CT demonstrated multiple air-filled cystic lesions in right upper lobe, and the patient subsequently underwent a right upper lobectomy. Histology revealed cystic lesions located in the pulmonary parenchyma and showed that the lesions were lined by lymphatic endothelium and were communicating with dilated lymphatic vessels in the interstitium. Additionally, multinucleated foreign body giant cells were attached to the lumen of the cyst. On the basis of these findings, we considered this a case of persistent interstitial pulmonary emphysema (PIPE) with massive pneumatic expansion of the lymphatic vessels, resulting in cystic lesions with lymphatic endothelium in the pulmonary parenchyma. While PIPE is extremely rare in term non-ventilated infants, our case demonstrated that this disease should be added to the differential diagnosis of cystic lung diseases with lymphatic endothelium even in infants without mechanical ventilation. When cystic lesions and symptoms persist despite conservative treatment, open or thoracoscopic resection is an appropriate option for diagnosis and treatment.

  6. Sensitivity and specificity of 3-D texture analysis of lung parenchyma is better than 2-D for discrimination of lung pathology in stage 0 COPD

    NASA Astrophysics Data System (ADS)

    Xu, Ye; Sonka, Milan; McLennan, Geoffrey; Guo, Junfeng; Hoffman, Eric

    2005-04-01

    Lung parenchyma evaluation via multidetector-row CT (MDCT), has significantly altered clinical practice in the early detection of lung disease. Our goal is to enhance our texture-based tissue classification ability to differentiate early pathologic processes by extending our 2-D Adaptive Multiple Feature Method (AMFM) to 3-D AMFM. We performed MDCT on 34 human volunteers in five categories: emphysema in severe Chronic Obstructive Pulmonary Disease (COPD) as EC, emphysema in mild COPD (MC), normal appearing lung in COPD (NC), non-smokers with normal lung function (NN), smokers with normal function (NS). We volumetrically excluded the airway and vessel regions, calculated 24 volumetric texture features for each Volume of Interest (VOI); and used Bayesian rules for discrimination. Leave-one-out and half-half methods were used for testing. Sensitivity, specificity and accuracy were calculated. The accuracy of the leave-one-out method for the four-class classification in the form of 3-D/2-D is: EC: 84.9%/70.7%, MC: 89.8%/82.7%; NC: 87.5.0%/49.6%; NN: 100.0%/60.0%. The accuracy of the leave-one-out method for the two-class classification in the form of 3-D/2-D is: NN: 99.3%/71.6%; NS: 99.7%/74.5%. We conclude that 3-D AMFM analysis of the lung parenchyma improves discrimination compared to 2-D analysis of the same images.

  7. Stereotactic radiotherapy for spinal intradural metastases developing within or adjacent to the previous irradiation field--report of three cases.

    PubMed

    Mori, Yoshimasa; Hashizume, Chisa; Shibamoto, Yuta; Kobayashi, Tatsuya; Nakazawa, Hisato; Hagiwara, Masahiro; Tsugawa, Takahiko

    2013-08-01

    Results of stereotactic radiotherapy (SRT) for spinal intradural metastases developing inside or adjacent to the previous external-beam radiation therapy (EBRT) field are shown in 3 cases. One case of spinal intramedullary metastasis and two cases of intradural extramedullary metastases were treated using a Novalis shaped-beam SRT. Case 1 developed an intramedullary metastatic tumor in the C1 spinal medulla inside the previous whole brain EBRT field and another lesion adjacent to the field in the C2 spinal medulla. Case 2 developed intradural extramedullary metastasis around C6-8 inside the previous EBRT field for the primary lung adenocarcinoma. Case 3 developed multiple spinal intradural extramedullary metastatic deposits after surgical resection and following whole brain EBRT for brain metastasis. We delivered 24 to 36 Gy in 5 to 12 fractions. The treated tumors were stable or decreased in size until the patients' death from the primary cancer (10, 22, and 5 months). Neurological symptoms were stable or improved in all 3 patients. Palliative SRT using Novalis is expected to be safe and effective even if the patient develops spinal intradural metastases within or adjacent to the previous irradiation field.

  8. Overall view of tower and adjacent aircraft shelters on flight ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Overall view of tower and adjacent aircraft shelters on flight line. View to east. - Plattsburgh Air Force Base, Security Guard Tower, Florida Street at Aircraft Shelters Area, Plattsburgh, Clinton County, NY

  9. Interior building details of Building A, dungeon cell adjacent to ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Interior building details of Building A, dungeon cell adjacent to northwest cell: granite and brick threshold, poured concrete floors, plastered finished walls, vaulted veiling; northwesterly view - San Quentin State Prison, Building 22, Point San Quentin, San Quentin, Marin County, CA

  10. 10. View north from the adjacent B & O railroad ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. View north from the adjacent B & O railroad bridge of portion of the Main truss span over the reservoir of the Augustine Paper Mills, National Register Site. - Augustine Bridge, Brandywine River,Augustine Cutoff, Wilmington, New Castle County, DE

  11. Lock 4 View east of lock wall and adjacent ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Lock 4 - View east of lock wall and adjacent roadway built atop tow path. The gate pocket can be seen at center. - Savannah & Ogeechee Barge Canal, Between Ogeechee & Savannah Rivers, Savannah, Chatham County, GA

  12. 1. A BRICK AND CONCRETE FAN HOUSING ADJACENT TO ONE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. A BRICK AND CONCRETE FAN HOUSING ADJACENT TO ONE OF THE ADIT OPENINGS (VIEW TO THE NORTH). - Foster Gulch Mine, Fan Housing, Bear Creek 1 mile Southwest of Town of Bear Creek, Red Lodge, Carbon County, MT

  13. 1. VIEW FROM ROOFTOP OF BUILDING (MOTEL) ADJACENT TO TECHWOOD ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. VIEW FROM ROOFTOP OF BUILDING (MOTEL) ADJACENT TO TECHWOOD HOMES, LOOKING SOUTH. GARAGE TO EXTREME LEFT, BUILDING 1 TO EXTREME RIGHT. - Techwood Homes (Public Housing), Bounded by North Avenue, Parker Street, William Street & Lovejoy Street, Atlanta, Fulton County, GA

  14. VIEW FROM ROOFTOP OF BUILDING (MOTEL) ADJACENT TO TECHWOOD HOMES, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW FROM ROOFTOP OF BUILDING (MOTEL) ADJACENT TO TECHWOOD HOMES, LOOKING SOUTH. GARAGE TO EXTREME LEFT, BUILDING 1 TO EXTREME RIGHT. - Techwood Homes, Building No. 16, 488-514 Techwood Drive, Atlanta, Fulton County, GA

  15. View from water showing south facade and adjacent boat slips ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View from water showing south facade and adjacent boat slips (Facility Nos. S375 & S376) - U.S. Naval Base, Pearl Harbor, Boat House, Hornet Avenue at Independence Street, Pearl City, Honolulu County, HI

  16. Cement Leakage into Adjacent Vertebral Body Following Percutaneous Vertebroplasty.

    PubMed

    Park, Jae Hoo; Kim, Hyeun Sung; Kim, Seok Won

    2016-06-01

    Percutaneous vertebroplasty (PV) is a minimally invasive procedure for osteoporotic vertebral compression fractures that fail to respond to conventional conservative treatment. It significantly improves intolerable back pain within hours, and has a low complication rate. Although rare, PV is not free of complications, most of which are directly related to cement leakage. Because of its association with new adjacent fracture, the importance of cement leakage into the adjacent disc space is paramount. Here, we report an interesting case of cement leakage into the adjacent upper vertebral body as well as disc space following PV. To the best of our knowledge, there has been no report of cement leakage into the adjacent vertebral body following PV. This rare case is presented along with a review of the literature.

  17. 15. View north from the adjacent B & O railroad ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    15. View north from the adjacent B & O railroad bridge of Pier No. 5 and portion of the deck and super-structure. - Augustine Bridge, Brandywine River,Augustine Cutoff, Wilmington, New Castle County, DE

  18. 7. View north from the adjacent B & O railroad ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. View north from the adjacent B & O railroad bridge of Pier No. 1 and portions of the deck and super-structure. - Augustine Bridge, Brandywine River,Augustine Cutoff, Wilmington, New Castle County, DE

  19. 8. View north from the adjacent B & O railroad ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. View north from the adjacent B & O railroad bridge of Pier No. 2 and portions of the deck and super-structure. - Augustine Bridge, Brandywine River,Augustine Cutoff, Wilmington, New Castle County, DE

  20. VIEW OF NORTHERN AND EASTERN SIDES FROM PARKING LOT ADJACENT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF NORTHERN AND EASTERN SIDES FROM PARKING LOT ADJACENT TO BUILDING 199 (POLICE STATION) - U.S. Naval Base, Pearl Harbor, Post Office, Avenue A near Eleventh Avenue, Pearl City, Honolulu County, HI

  1. Basement, room 23, looking southwest into two adjacent offices with ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Basement, room 23, looking southwest into two adjacent offices with soundproof walls and pedestal flooring - March Air Force Base, Strategic Air Command, Combat Operations Center, 5220 Riverside Drive, Moreno Valley, Riverside County, CA

  2. 3. View of north side of house facing from adjacent ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. View of north side of house facing from adjacent vacant property. Original wood lap siding and trim is covered by aluminum siding. Recessed side porch is in middle. - 645 South Eighteenth Street (House), Louisville, Jefferson County, KY

  3. View of viaduct, looking SE from roof of adjacent parking ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of viaduct, looking SE from roof of adjacent parking garage. - Mulberry Street Viaduct, Spanning Paxton Creek & Cameron Street (State Route 230) at Mulberry Street (State Route 3012), Harrisburg, Dauphin County, PA

  4. 1. Ninth Street (west) facade. Adjacent on the north is ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. Ninth Street (west) facade. Adjacent on the north is the 9th Street facade of 816 E Street. Both buildings were originally one property. - Riley Building, Rendezvous Adult Magazines & Films, 437 Ninth Street, Northwest, Washington, District of Columbia, DC

  5. 6. Detail, vertical guides adjacent to east portal of Tunnel ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. Detail, vertical guides adjacent to east portal of Tunnel 28, view to southwest, 135mm lens with electronic flash fill. - Central Pacific Transcontinental Railroad, Tunnel No. 28, Milepost 134.75, Applegate, Placer County, CA

  6. VIEW OF LAMP FIXTURE (EXTERIOR) ADJACENT TO ENTRANCE AT SOUTHWEST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF LAMP FIXTURE (EXTERIOR) ADJACENT TO ENTRANCE AT SOUTHWEST CORNER OF BUILDING 23, FACING NORTH - Roosevelt Base, Auditorium-Gymnasium, West Virginia Street between Richardson & Reeves Avenues, Long Beach, Los Angeles County, CA

  7. 73. PASSAGE ADJACENT TO ROOM 232, EAST WING, SECOND FLOOR, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    73. PASSAGE ADJACENT TO ROOM 232, EAST WING, SECOND FLOOR, LOOKING WEST BY NORTHWEST, SHOWING EASTERNMOST ARCH OF FORMER GREAT HALL NORTH ARCADE - Smithsonian Institution Building, 1000 Jefferson Drive, between Ninth & Twelfth Streets, Southwest, Washington, District of Columbia, DC

  8. Detail exterior view looking north showing piping system adjacent to ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Detail exterior view looking north showing piping system adjacent to engine house. Gas cooling system is on far right. - Burnsville Natural Gas Pumping Station, Saratoga Avenue between Little Kanawha River & C&O Railroad line, Burnsville, Braxton County, WV

  9. 52. EASTSIDE PLANT: GENERAL VIEW OF GOVERNOR ADJACENT TO GENERATOR ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    52. EASTSIDE PLANT: GENERAL VIEW OF GOVERNOR ADJACENT TO GENERATOR - American Falls Water, Power & Light Company, Island Power Plant, Snake River, below American Falls Dam, American Falls, Power County, ID

  10. OBLIQUE OF SOUTHWEST END AND SOUTHEAST SIDE, WITH ADJACENT FACILITY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    OBLIQUE OF SOUTHWEST END AND SOUTHEAST SIDE, WITH ADJACENT FACILITY 391 IN THE FOREGROUND. - U.S. Naval Base, Pearl Harbor, Joint Intelligence Center, Makalapa Drive in Makalapa Administration Area, Pearl City, Honolulu County, HI

  11. Brick incinerator structure located adjacent to "motor courts." This example ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Brick incinerator structure located adjacent to "motor courts." This example is located between Buildings 26 and 27. Facing northeast - Harbor Hills Housing Project, 26607 Western Avenue, Lomita, Los Angeles County, CA

  12. 7. August, 1970 9 ORANGE STREET, ADJACENT TO UNITARIAN CHURCH ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. August, 1970 9 ORANGE STREET, ADJACENT TO UNITARIAN CHURCH (NOT IN STUDY AREA) - Orange & Union Streets Neighborhood Study, 8-31 Orange Street, 9-21 Union Street & Stone Alley, Nantucket, Nantucket County, MA

  13. VIEW FROM ROOFTOP OF BUILDING (MOTEL) ADJACENT TO TECHWOOD HOME, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW FROM ROOFTOP OF BUILDING (MOTEL) ADJACENT TO TECHWOOD HOME, LOOKING WEST. GEORGIA TECH DORMITORY BUILDING, 581-587 TECHWOOD DRIVE, IN FOREGROUND. - Techwood Homes, Building No. 16, 488-514 Techwood Drive, Atlanta, Fulton County, GA

  14. 72. View of reservoir adjacent to south wall of blowing ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    72. View of reservoir adjacent to south wall of blowing engine house where water from furnaces was allowed to cool. - Sloss-Sheffield Steel & Iron, First Avenue North Viaduct at Thirty-second Street, Birmingham, Jefferson County, AL

  15. Repeated intratracheal instillation of PM10 induces lipid reshaping in lung parenchyma and in extra-pulmonary tissues.

    PubMed

    Rizzo, Angela Maria; Corsetto, Paola Antonia; Farina, Francesca; Montorfano, Gigliola; Pani, Giuseppe; Battaglia, Cristina; Sancini, Giulio; Palestini, Paola

    2014-01-01

    Adverse health effects of air pollution attributed mainly to airborne particulate matter have been well documented in the last couple of decades. Short term exposure, referring to a few hours exposure, to high ambient PM10 concentration is linked to increased hospitalization rates for cardiovascular events, typically 24 h after air pollution peaks. Particulate matter exposure is related to pulmonary and cardiovascular diseases, with increased oxidative stress and inflammatory status. Previously, we have demonstrated that repeated intratracheal instillation of PM10sum in BALB/c mice leads to respiratory tract inflammation, creating in lung a condition which could potentially evolve in a systemic toxic reaction. Additionally, plasma membrane and tissue lipids are easily affected by oxidative stress and directly correlated with inflammatory products. With this aim, in the present investigation using the same model, we analyzed the toxic potential of PM10sum exposure on lipid plasma membrane composition, lipid peroxidation and the mechanisms of cells protection in multiple organs such as lung, heart, liver and brain. Obtained results indicated that PM10 exposure led to lung lipid reshaping, in particular phospholipid and cholesterol content increases; concomitantly, the generation of oxidative stress caused lipid peroxidation. In liver we found significant changes in lipid content, mainly due to an increase of phosphatidylcholine, and in total fatty acid composition with a more pronounced level of docosahexaenoic acid; these changes were statistically correlated to lung molecular markers. Heart and brain were similarly affected; heart was significantly enriched in triglycerides in half of the PM10sum treated mice. These results demonstrated a direct involvement of PM10sum in affecting lipid metabolism and oxidative stress in peripheral tissues that might be related to the serious systemic air-pollution effects on human health.

  16. Metal content of biopsies adjacent to dental cast alloys.

    PubMed

    Garhammer, Pauline; Schmalz, G; Hiller, K-A; Reitinger, T

    2003-06-01

    Single case reports indicate that components of dental alloys accumulate in the adjacent soft tissue of the oral cavity. However, data on a wider range of dental alloys and patient groups are scarce. Therefore, the aim of the present study was to examine the metal content of oral tissues adjacent to dental alloys showing persisting signs of inflammation or other discoloration (affected sites) and of healthy control sites with no adjacent metal restoration in 28 patients. The composition of the adjacent alloys was analyzed and compared to the alloy components in the affected sites. Tissue analysis was performed using atomic absorption spectroscopy. Alloy analysis was performed with energy-dispersive X-ray analysis. In the affected sites, the metals Ag, Au, Cu, and Pd prevailed compared to control sites, reflecting the frequency distribution of single metals in the adjacent alloys. In most cases (84%), at least one of the analyzed metals was a component of the alloy and also detected in the tissue. Metal components from almost all dental cast alloys can be detected in adjacent tissue.

  17. Metal-based nanoparticle interactions with the nervous system: The challenge of brain entry and the risk of retention in the organism

    EPA Science Inventory

    This review of metal and metal-oxide based nanoparticles focuses on factors that influence their distribution into the nervous system, evidence that they enter brain parenchyma, and nervous system responses. Emphasis is placed on gold as a model metal-based nanoparticle and for r...

  18. In vivo transport of a dynorphin-like analgesic peptide, E-2078, through the blood-brain barrier: an application of brain microdialysis.

    PubMed

    Terasaki, T; Deguchi, Y; Sato, H; Hirai, K; Tsuji, A

    1991-07-01

    In vivo transport through the blood-brain barrier (BBB) has been demonstrated for a dynorphin-like analgesic peptide, CH3-[125I]Tyr-Gly-Gly-Phe-Leu-Arg-CH3Arg-D-Leu-NHC2H5 ( [125I]E-2078). A remarkable time-dependent increase in the distribution volume of [125I]E-2078 in the brain parenchyma separated from blood vessels and capillaries was observed during a brain perfusion. The distribution volume of [125I]E-2078 in the brain parenchyma after 20 min of perfusion was 2.18 +/- 0.09 microliters/g brain (mean +/- SE) and was significantly greater than the distribution volume of [3H]inulin (0.994 +/- 0.138 microliters/g brain), providing in vivo evidence for the penetration of [125I]E-2078 into the brain parenchyma. Brain microdialysis was carried out to collect directly the brain interstitial fluid (ISF) during the brain perfusion of [125I]E-2078. No metabolite of [125I]E-2078 in the brain ISF was found by high-performance liquid chromatographic analysis of the brain dialysate. The concentrations of [125I]E-2078 and [14C]sucrose in the brain ISF were estimated based on an in vitro evaluation of dialysis clearance. The concentration ratio of [125I]E-2078 between the brain ISF and the brain perfusate was determined to be 2.92 x 10(-1) +/- 0.50 x 10(-1) and was approximately 100 times higher than that of [14C]sucrose (2.71 x 10(-3) +/- 1.43 x 10(-3), demonstrating transport of [125I]E-2078 through the BBB in vivo. On the other hand, no remarkable difference in the cerebrospinal fluid (CSF)-to-perfusate concentration ratios of [125I]E-2078 and [14C]sucrose was observed, indicating little contribution of the blood-CSF barrier (BCSF barrier) transport to the penetration of [125I]E-2078 into the brain.

  19. Brain Tumors

    MedlinePlus

    A brain tumor is a growth of abnormal cells in the tissues of the brain. Brain tumors can be benign, with no cancer cells, ... cancer cells that grow quickly. Some are primary brain tumors, which start in the brain. Others are ...

  20. A peptide for targeted, systemic delivery of imaging and therapeutic compounds into acute brain injuries

    PubMed Central

    Mann, Aman P.; Scodeller, Pablo; Hussain, Sazid; Joo, Jinmyoung; Kwon, Ester; Braun, Gary B.; Mölder, Tarmo; She, Zhi-Gang; Kotamraju, Venkata Ramana; Ranscht, Barbara; Krajewski, Stan; Teesalu, Tambet; Bhatia, Sangeeta; Sailor, Michael J.; Ruoslahti, Erkki

    2016-01-01

    Traumatic brain injury (TBI) is a major health and socio-economic problem, but no pharmacological agent is currently approved for the treatment of acute TBI. Thus, there is a great need for advances in this field. Here, we describe a short peptide (sequence CAQK) identified by in vivo phage display screening in mice with acute brain injury. The CAQK peptide selectively binds to injured mouse and human brain, and systemically injected CAQK specifically homes to sites of brain injury in mouse models. The CAQK target is a proteoglycan complex upregulated in brain injuries. Coupling to CAQK increased injury site accumulation of systemically administered molecules ranging from a drug-sized molecule to nanoparticles. CAQK-coated nanoparticles containing silencing oligonucleotides provided the first evidence of gene silencing in injured brain parenchyma by systemically administered siRNA. These findings present an effective targeting strategy for the delivery of therapeutics in clinical management of acute brain injuries. PMID:27351915

  1. A peptide for targeted, systemic delivery of imaging and therapeutic compounds into acute brain injuries

    NASA Astrophysics Data System (ADS)

    Mann, Aman P.; Scodeller, Pablo; Hussain, Sazid; Joo, Jinmyoung; Kwon, Ester; Braun, Gary B.; Mölder, Tarmo; She, Zhi-Gang; Kotamraju, Venkata Ramana; Ranscht, Barbara; Krajewski, Stan; Teesalu, Tambet; Bhatia, Sangeeta; Sailor, Michael J.; Ruoslahti, Erkki

    2016-06-01

    Traumatic brain injury (TBI) is a major health and socio-economic problem, but no pharmacological agent is currently approved for the treatment of acute TBI. Thus, there is a great need for advances in this field. Here, we describe a short peptide (sequence CAQK) identified by in vivo phage display screening in mice with acute brain injury. The CAQK peptide selectively binds to injured mouse and human brain, and systemically injected CAQK specifically homes to sites of brain injury in mouse models. The CAQK target is a proteoglycan complex upregulated in brain injuries. Coupling to CAQK increased injury site accumulation of systemically administered molecules ranging from a drug-sized molecule to nanoparticles. CAQK-coated nanoparticles containing silencing oligonucleotides provided the first evidence of gene silencing in injured brain parenchyma by systemically administered siRNA. These findings present an effective targeting strategy for the delivery of therapeutics in clinical management of acute brain injuries.

  2. Brain surgery

    MedlinePlus

    Craniotomy; Surgery - brain; Neurosurgery; Craniectomy; Stereotactic craniotomy; Stereotactic brain biopsy; Endoscopic craniotomy ... cut depends on where the problem in the brain is located. The surgeon creates a hole in ...

  3. Brain Malformations

    MedlinePlus

    Most brain malformations begin long before a baby is born. Something damages the developing nervous system or causes it ... medicines, infections, or radiation during pregnancy interferes with brain development. Parts of the brain may be missing, ...

  4. Brain components

    MedlinePlus Videos and Cool Tools

    The brain is composed of more than a thousand billion neurons. Specific groups of them, working in concert, provide ... of information. The 3 major components of the brain are the cerebrum, cerebellum, and brain stem. The ...

  5. Dimethyl sulfoxide (DMSO) as a potential contrast agent for brain tumors.

    PubMed

    Delgado-Goñi, T; Martín-Sitjar, J; Simões, R V; Acosta, M; Lope-Piedrafita, S; Arús, C

    2013-02-01

    Dimethyl sulfoxide (DMSO) is commonly used in preclinical studies of animal models of high-grade glioma as a solvent for chemotherapeutic agents. A strong DMSO signal was detected by single-voxel MRS in the brain of three C57BL/6 control mice during a pilot study of DMSO tolerance after intragastric administration. This led us to investigate the accumulation and wash-out kinetics of DMSO in both normal brain parenchyma (n=3 control mice) by single-voxel MRS, and in 12 GL261 glioblastomas (GBMs) by single-voxel MRS (n=3) and MRSI (n=9). DMSO accumulated differently in each tissue type, reaching its highest concentration in tumors: 6.18 ± 0.85 µmol/g water, 1.5-fold higher than in control mouse brain (p<0.05). A faster wash-out was detected in normal brain parenchyma with respect to GBM tissue: half-lives of 2.06 ± 0.58 and 4.57 ± 1.15 h, respectively. MRSI maps of time-course DMSO changes revealed clear hotspots of differential spatial accumulation in GL261 tumors. Additional MRSI studies with four mice bearing oligodendrogliomas (ODs) revealed similar results as in GBM tumors. The lack of T(1) contrast enhancement post-gadolinium (gadopentetate dimeglumine, Gd-DTPA) in control mouse brain and mice with ODs suggested that DMSO was fully able to cross the intact blood-brain barrier in both normal brain parenchyma and in low-grade tumors. Our results indicate a potential role for DMSO as a contrast agent for brain tumor detection, even in those tumors 'invisible' to standard gadolinium-enhanced MRI, and possibly for monitoring heterogeneities associated with progression or with therapeutic response.

  6. Biomechanical effects of pedicle screw fixation on adjacent segments.

    PubMed

    Kyaw, Thein Aung; Wang, Zhuo; Sakakibara, Toshihiko; Yoshikawa, Takamasa; Inaba, Tadashi; Kasai, Yuichi

    2014-07-01

    Various biomechanical investigations have attempted to clarify the aetiology of adjacent segment disease (ASD). However, no biomechanical study has examined in detail the deformation behaviour of the adjacent segments when both pure torque and an angular displacement load are applied to the vertebrae along multiple segments. The purpose of this study is to investigate the biomechanical effects of pedicle screw fixation on adjacent segments. Ten cadaveric lumbar spines (L2-L5) of boars were used. Control and fusion models were prepared by disc damage and pedicle screw fixation of each specimen, and then, bending and rotation tests were performed using a six-axis material tester. In the biomechanical tests regulated by an angular displacement load, the range of motion (ROM) of the cranial and caudal adjacent segments in antero-posterior flexion and lateral bending was increased by about 20 % (p < 0.05), and the maximal torque in the fusion model was about threefold (p < 0.05) that in the control model. And in axial rotation, the ROM of cranial and caudal adjacent segments was increased by about 100 % (p < 0.001), and the maximal torque was about sixfold (p < 0.01) that in the control model. The ROM of adjacent segments was significantly increased after pedicle screw fixation as assessed by biomechanical tests regulated by an angular displacement load, but not in those regulated by torque. We present the results of biomechanical tests regulated by torque and angular displacement and show that the maximum torque of the fusion model was larger than that of the control model in the biomechanical test regulated by an angular displacement load, suggesting that mechanical stress on the segments adjacent to the fused segment is large. We think that ASD arises after spinal fusion surgery as a mechanism to compensate for the ROM lost due to excessive fusion by pedicle screw fixation, so that a large torque may be applied to adjacent segments within a physiologically

  7. Brain injury associated with widely abused amphetamines: neuroinflammation, neurogenesis and blood-brain barrier.

    PubMed

    Silva, Ana P; Martins, Tânia; Baptista, Sofia; Gonçalves, Joana; Agasse, Fabienne; Malva, João O

    2010-12-01

    Over the course of the 20(th) century, it became increasingly clear that amphetamine-like psychostimulants carried serious abuse liability that has resulted in sociological use patterns that have been described as epidemics. In fact, drug addiction is a brain disease with a high worldwide prevalence, and is considered the most expensive of the neuropsychiatric disorders. This review goes beyond the previously well-documented evidence demonstrating that amphetamines cause neuronal injury. Cellular and molecular mechanisms involved in the neurotoxicity of psychostimulants drugs have been extensively described giving particular attention to the role of oxidative stress and metabolic compromise. Recently, it was shown that the amphetamine class of drugs of abuse triggers an inflammatory process, emerging as a critical concept to understand the toxic effects of these drugs. Moreover, it has been suggested that psychostimulants compromise the capacity of the brain to generate new neurons (neurogenesis), and can also lead to blood-brain barrier (BBB) dysfunction. Together, these effects may contribute to brain damage, allowing the entry of pathogens into the brain parenchyma and thus decreasing the endogenous brain repair resources. The overall objective of this review is to highlight experimental evidence in an attempt to clarify the role of neuroinflammation in amphetamines-induced brain dysfunction and the effect of these drugs on both neurogenesis and BBB integrity.

  8. Viscoelastic Model for Lung Parenchyma for Multi-Scale Modeling of Respiratory System Phase I: Hypo-Elastic Model for CFD Implementation

    SciTech Connect

    Freed, Alan D.; Einstein, Daniel R.

    2011-04-14

    An isotropic constitutive model for the parenchyma of lung has been derived from the theory of hypo-elasticity. The intent is to use it to represent the mechanical response of this soft tissue in sophisticated, computational, fluid-dynamic models of the lung. This demands that the continuum model be accurate, yet simple and effcient. An objective algorithm for its numeric integration is provided. The response of the model is determined for several boundary-value problems whose experiments are used for material characterization. The effective elastic, bulk, and shear moduli, and Poisson’s ratio, as tangent functions, are also derived. The model is characterized against published experimental data for lung. A bridge between this continuum model and a dodecahedral model of alveolar geometry is investigated, with preliminary findings being reported.

  9. Evaluation of liver parenchyma and perfusion using dynamic contrast-enhanced computed tomography and contrast-enhanced ultrasonography in captive green iguanas (Iguana iguana) under general anesthesia

    PubMed Central

    2014-01-01

    Background Contrast-enhanced diagnostic imaging techniques are considered useful in veterinary and human medicine to evaluate liver perfusion and focal hepatic lesions. Although hepatic diseases are a common occurrence in reptile medicine, there is no reference to the use of contrast-enhanced ultrasound (CEUS) and contrast-enhanced computed tomography (CECT) to evaluate the liver in lizards. Therefore, the aim of this study was to evaluate the pattern of change in echogenicity and attenuation of the liver in green iguanas (Iguana iguana) after administration of specific contrast media. Results An increase in liver echogenicity and density was evident during CEUS and CECT, respectively. In CEUS, the mean ± SD (median; range) peak enhancement was 19.9% ± 7.5 (18.3; 11.7-34.6). Time to peak enhancement was 134.0 ± 125.1 (68.4; 59.6-364.5) seconds. During CECT, first visualization of the contrast medium was at 3.6 ± 0.5 (4; 3-4) seconds in the aorta, 10.7 ± 2.2 (10.5; 7-14) seconds in the hepatic arteries, and 15 ± 4.5 (14.5; 10-24) seconds in the liver parenchyma. Time to peak was 14.1 ± 3.4 (13; 11-21) and 31 ± 9.6 (29; 23-45) seconds in the aorta and the liver parenchyma, respectively. Conclusion CEUS and dynamic CECT are practical means to determine liver hemodynamics in green iguanas. Distribution of contrast medium in iguana differed from mammals. Specific reference ranges of hepatic perfusion for diagnostic evaluation of the liver in iguanas are necessary since the use of mammalian references may lead the clinician to formulate incorrect diagnostic suspicions. PMID:24885935

  10. Infusion of hypertonic saline into the lung parenchyma during radiofrequency ablation of the lungs with multitined expandable electrodes: results using a porcine model.

    PubMed

    Iishi, Tatsuhiko; Hiraki, Takao; Mimura, Hidefumi; Gobara, Hideo; Kurose, Taichi; Fujiwara, Hiroyasu; Sakurai, Jun; Yanai, Hiroyuki; Yoshino, Tadashi; Kanazawa, Susumu

    2009-06-01

    The present study was performed to clarify the effect of hypertonic saline infusion into the lung parenchyma on radiofrequency ablation (RFA) of the lungs. A total of 20 ablation zones were created in 3 pigs. The ablation zones were divided into 3 groups. Group 1 (n=6) consisted of ablation zones created by applying smaller radiofrequency (RF) power without saline infusion; group 2 (n=5) zones were created by applying greater RF power without saline infusion;and group 3 (n=9) zones were created by applying greater RF power with saline infusion. The techniques of saline infusion included administration of hypertonic saline 1 ml before RFA, followed by continuous administration at a rate of 1 ml/min during the first 2 min after the initiation of RFA. The ablation parameters and coagulation necrosis volumes were compared among the groups. Group 3 had a tendency toward smaller mean impedance than group 1 (p=0.059) and group 2 (p=0.053). Group 3 showed significantly longer RF application time than group 2 (p=0.004) and significantly greater maximum RF power than group 1 (p=0.001) and group 2 (p=0.004). Group 3 showed significantly larger coagulation necrosis volume (mean, 1,421mm3) than group 2 (mean, 858 mm3, p=0.039) and had a tendency toward larger necrosis volume than group 1 (mean, 878 mm3, p=0.077). Although this small study had limited statistical power, hypertonic saline infusion during RFA appeared to enlarge coagulation necrosis of the lung parenchyma.

  11. Laplacian versus adjacency matrix in quantum walk search

    NASA Astrophysics Data System (ADS)

    Wong, Thomas G.; Tarrataca, Luís; Nahimov, Nikolay

    2016-10-01

    A quantum particle evolving by Schrödinger's equation contains, from the kinetic energy of the particle, a term in its Hamiltonian proportional to Laplace's operator. In discrete space, this is replaced by the discrete or graph Laplacian, which gives rise to a continuous-time quantum walk. Besides this natural definition, some quantum walk algorithms instead use the adjacency matrix to effect the walk. While this is equivalent to the Laplacian for regular graphs, it is different for non-regular graphs and is thus an inequivalent quantum walk. We algorithmically explore this distinction by analyzing search on the complete bipartite graph with multiple marked vertices, using both the Laplacian and adjacency matrix. The two walks differ qualitatively and quantitatively in their required jumping rate, runtime, sampling of marked vertices, and in what constitutes a natural initial state. Thus the choice of the Laplacian or adjacency matrix to effect the walk has important algorithmic consequences.

  12. Modeling fires in adjacent ship compartments with computational fluid dynamics

    SciTech Connect

    Wix, S.D.; Cole, J.K.; Koski, J.A.

    1998-05-10

    This paper presents an analysis of the thermal effects on radioactive (RAM) transportation packages with a fire in an adjacent compartment. An assumption for this analysis is that the adjacent hold fire is some sort of engine room fire. Computational fluid dynamics (CFD) analysis tools were used to perform the analysis in order to include convective heat transfer effects. The analysis results were compared to experimental data gathered in a series of tests on tile US Coast Guard ship Mayo Lykes located at Mobile, Alabama.

  13. Management of adjacent segment disease after cervical spinal fusion.

    PubMed

    Kepler, Christopher K; Hilibrand, Alan S

    2012-01-01

    Adjacent segment disease (ASD) was described after long-term follow-up of patients treated with cervical fusion. The term describes new-onset radiculopathy or myelopathy referable to a motion segment adjacent to previous arthrodesis and often attributed to alterations in the biomechanical environment after fusion. Evidence suggests that ASD affects between 2% and 3% of patients per year. Although prevention of ASD was one major impetus behind the development of motion-sparing surgery, the literature does not yet clearly distinguish a difference in the rate of ASD between fusion and disk replacement. Surgical techniques during index surgery may reduce the rate of ASD.

  14. Blood-brain barrier transport machineries and targeted therapy of brain diseases

    PubMed Central

    Barar, Jaleh; Rafi, Mohammad A.; Pourseif, Mohammad M.; Omidi, Yadollah

    2016-01-01

    Introduction: Desired clinical outcome of pharmacotherapy of brain diseases largely depends upon the safe drug delivery into the brain parenchyma. However, due to the robust blockade function of the blood-brain barrier (BBB), drug transport into the brain is selectively controlled by the BBB formed by brain capillary endothelial cells and supported by astrocytes and pericytes. Methods: In the current study, we have reviewed the most recent literature on the subject to provide an insight upon the role and impacts of BBB on brain drug delivery and targeting. Results: All drugs, either small molecules or macromolecules, designated to treat brain diseases must adequately cross the BBB to provide their therapeutic properties on biological targets within the central nervous system (CNS). However, most of these pharmaceuticals do not sufficiently penetrate into CNS, failing to meet the intended therapeutic outcomes. Most lipophilic drugs capable of penetrating BBB are prone to the efflux functionality of BBB. In contrast, all hydrophilic drugs are facing severe infiltration blockage imposed by the tight cellular junctions of the BBB. Hence, a number of strategies have been devised to improve the efficiency of brain drug delivery and targeted therapy of CNS disorders using multimodal nanosystems (NSs). Conclusions: In order to improve the therapeutic outcomes of CNS drug transfer and targeted delivery, the discriminatory permeability of BBB needs to be taken under control. The carrier-mediated transport machineries of brain capillary endothelial cells (BCECs) can be exploited for the discovery, development and delivery of small molecules into the brain. Further, the receptor-mediated transport systems can be recruited for the delivery of macromolecular biologics and multimodal NSs into the brain. PMID:28265539

  15. Lymphatic Clearance of the Brain: Perivascular, Paravascular and Significance for Neurodegenerative Diseases.

    PubMed

    Bakker, Erik N T P; Bacskai, Brian J; Arbel-Ornath, Michal; Aldea, Roxana; Bedussi, Beatrice; Morris, Alan W J; Weller, Roy O; Carare, Roxana O

    2016-03-01

    The lymphatic clearance pathways of the brain are different compared to the other organs of the body and have been the subject of heated debates. Drainage of brain extracellular fluids, particularly interstitial fluid (ISF) and cerebrospinal fluid (CSF), is not only important for volume regulation, but also for removal of waste products such as amyloid beta (Aβ). CSF plays a special role in clinical medicine, as it is available for analysis of biomarkers for Alzheimer's disease. Despite the lack of a complete anatomical and physiological picture of the communications between the subarachnoid space (SAS) and the brain parenchyma, it is often assumed that Aβ is cleared from the cerebral ISF into the CSF. Recent work suggests that clearance of the brain mainly occurs during sleep, with a specific role for peri- and para-vascular spaces as drainage pathways from the brain parenchyma. However, the direction of flow, the anatomical structures involved and the driving forces remain elusive, with partially conflicting data in literature. The presence of Aβ in the glia limitans in Alzheimer's disease suggests a direct communication of ISF with CSF. Nonetheless, there is also the well-described pathology of cerebral amyloid angiopathy associated with the failure of perivascular drainage of Aβ. Herein, we review the role of the vasculature and the impact of vascular pathology on the peri- and para-vascular clearance pathways of the brain. The different views on the possible routes for ISF drainage of the brain are discussed in the context of pathological significance.

  16. Kinetics of functionalised carbon nanotube distribution in mouse brain after systemic injection: Spatial to ultra-structural analyses

    PubMed Central

    Wang, Julie T.-W.; Rubio, Noelia; Kafa, Houmam; Venturelli, Enrica; Fabbro, Chiara; Ménard-Moyon, Cécilia; Da Ros, Tatiana; Sosabowski, Jane K.; Lawson, Alastair D.; Robinson, Martyn K.; Prato, Maurizio; Bianco, Alberto; Festy, Frederic; Preston, Jane E.; Kostarelos, Kostas; Al-Jamal, Khuloud T.

    2016-01-01

    Earlier studies proved the success of using chemically functionalised multi-walled carbon nanotubes (f-MWNTs) as nanocarriers to the brain. Little insight into the kinetics of brain distribution of f-MWNTs in vivo has been reported. This study employed a wide range of qualitative and quantitative techniques with the aim of shedding the light on f-MWNT's brain distribution following intravenous injection. γ-Scintigraphy quantified the uptake of studied radiolabelled f-MWNT in the whole brain parenchyma and capillaries while 3D-single photon emission computed tomography/computed tomography imaging and autoradiography illustrated spatial distribution within various brain regions. Raman and multiphoton luminescence together with transmission electron microscopy confirmed the presence of intact f-MWNT in mouse brain, in a label-free manner. The results evidenced the presence of f-MWNT in mice brain parenchyma, in addition to brain endothelium. Such information on the rate and extent of regional and cellular brain distribution is needed before further implementation into neurological therapeutics can be made. PMID:26742944

  17. Beta-endorphin chimeric peptides: Transport through the blood-brain barrier in vivo and cleavage of disulfide linkage by brain

    SciTech Connect

    Pardridge, W.M.; Triguero, D.; Buciak, J.L. )

    1990-02-01

    Water soluble peptides are normally not transported through the blood-brain barrier (BBB). Chimeric peptides may be transportable through the BBB and are formed by the covalent coupling of a nontransportable peptide to a transportable peptide vector, e.g. cationized albumin, using disulfide-based coupling reagents such as N-succinimidyl 3-(2-pyridyldithio(propionate)) (SPDP). The transcytosis of peptide into brain parenchyma, as opposed to vascular sequestration of blood-borne peptide, was quantified using an internal carotid artery perfusion/capillary depletion method. It is shown that (125I)beta-endorphin is not transported through the BBB, but is rapidly cleaved to free (125I) tyrosine via capillary peptidase. Therefore, chimeric peptide was prepared using (125I) (D-Ala2)beta-endorphin (DABE), owing to the resistance of this analogue to peptidase degradation. The (125I) DABE-cationized albumin chimeric peptide is shown to enter brain parenchyma at a rate comparable to that reported previously for unconjugated cationized albumin. When the (125I) DABE-cationized albumin chimeric peptide was incubated with rat brain homogenate at 37 C, the free (125I) DABE was liberated from the cationized albumin conjugate prior to its subsequent degradation into free (125I) tyrosine. Approximately 50% of the chimeric peptide was cleaved within 60 sec of incubation at 37 C. These studies demonstrate that (1) (125I)beta-endorphin is not transported through the BBB in its unconjugated form, (2) a (125I) DABE-cationized albumin chimeric peptide is transported through the BBB into brain parenchyma at a rate comparable to the unconjugated cationized albumin, and (3) brain contains the necessary disulfide reductases for rapid cleavage of the chimeric peptide into free beta-endorphin and this cleavage occurs before degradation of the (125I) DABE into (125I) tyrosine.

  18. Replacement of osmotic minipumps to extend the intracerebral infusion time of compounds into the mouse brain.

    PubMed

    Grathwohl, Stefan A; Jucker, Mathias

    2013-08-01

    Osmotic minipumps represent a convenient and established method for targeted delivery of agents into the brain of small rodents. Agents unable to cross the blood brain barrier can be directly infused into the brain parenchyma or lateral ventricle through implanted cannulas. The small volume of the minipump reservoir typically limits the infusion time to 4-6 weeks. Pump changes with reattachment of a new pump reservoir to the cannula might lead to brain tissue irritation or increased intracranial pressure associated with hydrocephalus. Here, we describe a pump reservoir exchange technique using a Y-shaped connection piece (Y-con) between the infusion cannula and the pump reservoir. This allows repeated replacement of a subcutaneously installed pump reservoir for brain delivery of agents in mice. Experimental evaluation of Y-con pump replacement revealed no signs of tissue irritation or hydrocephalus and allowed extended controlled delivery of infusion agents in the brain.

  19. [Meningitis and brain abscess caused by Streptococcus intermedius in a patient infected with HIV-1].

    PubMed

    Vallalta Morales, M; Solaz Moreno, E; Lacruz Rodrigo, J; Salavert Lletí, M; Silla Burdalo, G; Pérez-Bellés, C

    2005-06-01

    Streptococcus milleri group have been recognized as an important pathogens for abscess formation in various organs. Streptococci other than Streptococcus pneumoniae are a rare cause of bacterial meningitis in adults and can be associated with the presence of an undiagnosed brain abscess. Brain abscess is a focal collection within the brain parenchyma which can arise as a complication of a variety of infections. The most common etiologic organisms in clinical series have been microaerophilic streptococci and anaerobic bacteria. Although intracranial mass lesions that occur as a result of infection have commonly been reported in patients infected with the human immunodeficiency virus, brain abscess due to the common bacterial pathogens are rarely described in HIV infected patients and Toxoplasma gondii is the organism most frequently isolated from stereotactic brain biopsy in these patients. We report a patient with both HIV-1 infection and streptococcal meningitis secondary to brain abscess caused by S. intermedius.

  20. A Quantitative Analysis of Brain Soluble Tau and the Tau Secretion Factor.

    PubMed

    Han, Pengcheng; Serrano, Geidy; Beach, Thomas G; Caselli, Richard J; Yin, Junxiang; Zhuang, Ningning; Shi, Jiong

    2017-01-09

    Neurofibrillary tangles (NFTs) represent products of insoluble tau protein in the brains of patients with Alzheimer disease (AD). The cerebrospinal fluid (CSF) tau level is a biomarker in AD diagnosis. The soluble portion of tau protein in brain parenchyma is presumably the source for CSF tau but this has not previously been quantified. We measured CSF tau and soluble brain tau at autopsy in temporal and frontal brain tissue samples from 7 cognitive normal, 12 mild cognitively impaired, and 19 AD subjects. Based on the measured brain soluble tau, we calculated the whole brain tau load and estimated tau secretion factor. Our results suggest that the increase in NFT in AD is likely attributable to post-translational processes; the increase in CSF tau in AD patients is due to an accelerated carrier-based secretion. Moreover, cognitive dysfunction assessed by final Mini-Mental State Examination scores correlated with the secretion factor but not with the soluble tau.

  1. Aquaporin-4 expression contributes to decreases in brain water content during mouse postnatal development.

    PubMed

    Li, Xiumiao; Gao, Junying; Ding, Jiong; Hu, Gang; Xiao, Ming

    2013-05-01

    The water channel protein aquaporin-4 (AQP4) is implicated to facilitate water efflux from the brain parenchyma into the blood and CSF, playing a critical role in maintaining brain water homeostasis. Nevertheless, its contribution to decreases in brain water content during postnatal development remains unknown. A quantitative Western blot analysis was performed to investigate developmental expression of AQP4 in the whole mouse brain and showed that AQP4 expression level in 1 week-old brain was only 21.3% of that in the adult brain, but significantly increased to 67.4% of the adult level by 2 weeks after birth. Statistical analysis demonstrated that increased AQP4 expression partially relates to decreased brain water content in postnatal mice (r(2)=0.92 and P=0.002). Moreover, AQP4 null mice had greater brain water content than littermate controls from 2 weeks up to adult age. Consistently, mature pattern of AQP4 localization at the brain-blood and brain-CSF interfaces were completed at approximately at 2 weeks after birth. In addition, AQP4 expression in the brain stem and hypothalamus was earlier than that in the cerebral cortex and cerebellum, suggesting a brain regional variation in developmental expression of AQP4. These results characterize the developmental feature of AQP4 expression in the postnatal brain and provide direct evidence for a role of AQP4 in postnatal brain water uptake.

  2. LEHR NO. 2 AND LEHR NO. 3 ADJACENT TO FURNACE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    LEHR NO. 2 AND LEHR NO. 3 ADJACENT TO FURNACE ROOM; THE PIPES AT THE BOTTOM ARE PART OF THE RADIANT HEATING SYSTEM USED FOR HEATING THE FACTORY DURING COLD WEATHER. - Westmoreland Glass Company, Seventh & Kier Streets, Grapeville, Westmoreland County, PA

  3. Biogeochemistry of hydrothermally and adjacent non-altered soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    As a field/lab project, students in the Soil Biogeochemistry class of the University of Nevada, Reno described and characterized seven pedons, developed in hydrothermally and adjacent non-hydrothermally altered andesitic parent material near Reno, NV. Hydrothermally altered soils had considerably lo...

  4. 12. LOG FOUNDATION ELEMENTS OF THE SAWMILL ADJACENT TO THE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. LOG FOUNDATION ELEMENTS OF THE SAWMILL ADJACENT TO THE CANAL, LOOKING EAST. BARREN AREA IN FOREGROUND IS DECOMPOSING SAWDUST. DIRT PILE IN BACKGROUND IS THE EDGE OF THE SUMMIT COUNTY LANDFILL. - Snake River Ditch, Headgate on north bank of Snake River, Dillon, Summit County, CO

  5. Measurement Methods to Determine Air Leakage Between Adjacent Zones

    SciTech Connect

    Hult, Erin L.; Dickerhoff, Darryl J.; Price, Phillip N.

    2012-09-01

    Air leakage between adjacent zones of a building can lead to indoor air quality and energy efficiency concerns, however there is no existing standard for measuring inter-zonal leakage. In this study, synthesized data and field measurements are analyzed in order to explore the uncertainty associated with different methods for collecting and analyzing fan pressurization measurements to calculate interzone leakage.

  6. 1. OVERVIEW SHOWING FIRING CONTROL BLOCKHOUSE 0502 AND ADJACENT OBSERVATION ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. OVERVIEW SHOWING FIRING CONTROL BLOCKHOUSE 0502 AND ADJACENT OBSERVATION TOWER. WATER BRAKE TROUGH SEGMENT AT LOWER RIGHT. Looking north northeast. - Edwards Air Force Base, South Base Sled Track, Firing & Control Blockhouse for 10,000-foot Track, South of Sled Track at midpoint of 20,000-foot track, Lancaster, Los Angeles County, CA

  7. 45. 1915 CLOTH ROOM ADJACENT TO PICKER ROOM, SECOND FLOOR, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    45. 1915 CLOTH ROOM ADJACENT TO PICKER ROOM, SECOND FLOOR, NORTH END OF MILL NO. 2, WALL ON LEFT DIVIDING CLOTH ROOM ADDED LATER (PROBABLY C. 1970s). - Prattville Manufacturing Company, Number One, 242 South Court Street, Prattville, Autauga County, AL

  8. 11. View north from the adjacent B & O railroad ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    11. View north from the adjacent B & O railroad bridge of portion of the Main truss span over the reservoir of the Augustine Paper Mills, National Register Site, including Pier No. 4. - Augustine Bridge, Brandywine River,Augustine Cutoff, Wilmington, New Castle County, DE

  9. 12. View north from the adjacent B & O railroad ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. View north from the adjacent B & O railroad bridge of portion of the Main truss span over the reservoir of the Augustine Paper Mills, National Register Site, including Pier No. 4. - Augustine Bridge, Brandywine River,Augustine Cutoff, Wilmington, New Castle County, DE

  10. 10. Detail and contextual view of bridge and adjacent farmstead ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. Detail and contextual view of bridge and adjacent farmstead setting. Note laced vertical compression members, latticed portal strut, decorative strut bracing, and lightness of diagonal and lateral tension members. View to southeast through southeast portal from truss mid-span. - Red Bank Creek Bridge, Spanning Red Bank Creek at Rawson Road, Red Bluff, Tehama County, CA

  11. 47 CFR 73.810 - Third adjacent channel interference.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... RADIO BROADCAST SERVICES Low Power FM Broadcast Stations (LPFM) § 73.810 Third adjacent channel... power FM, FM translator or FM booster station to such affected station and to the Commission. (ii) A full power FM, FM translator or FM booster station shall review all complaints it receives,...

  12. 47 CFR 73.810 - Third adjacent channel interference.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... RADIO BROADCAST SERVICES Low Power FM Broadcast Stations (LPFM) § 73.810 Third adjacent channel... power FM, FM translator or FM booster station to such affected station and to the Commission. (ii) A full power FM, FM translator or FM booster station shall review all complaints it receives,...

  13. 8. Exterior view, showing tank and associated piping adjacent to ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. Exterior view, showing tank and associated piping adjacent to Test Cell 6, Systems Integration Laboratory Building (T-28), looking south. - Air Force Plant PJKS, Systems Integration Laboratory, Systems Integration Laboratory Building, Waterton Canyon Road & Colorado Highway 121, Lakewood, Jefferson County, CO

  14. VIEW FROM ATOP ADJACENT RESIDENTIAL TOWER, SHOWING RECREATION AREA ON ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW FROM ATOP ADJACENT RESIDENTIAL TOWER, SHOWING RECREATION AREA ON RIGHT, AND HOUSING AREA ON LEFT. VIEW FACING EAST/NORTHEAST - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Intersection of Acacia Road and Brich Circle, Pearl City, Honolulu County, HI

  15. VIEW FROM ATOP ADJACENT RESIDENTIAL TOWER, SHOWING RECREATION AREA AND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW FROM ATOP ADJACENT RESIDENTIAL TOWER, SHOWING RECREATION AREA AND ENTRY TO NEIGHBORHOOD. VIEW FACING SOUTHEAST - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Intersection of Acacia Road and Brich Circle, Pearl City, Honolulu County, HI

  16. VIEW FROM ATOP ADJACENT RESIDENTIAL TOWER, SHOWING WESTERN SIDE OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW FROM ATOP ADJACENT RESIDENTIAL TOWER, SHOWING WESTERN SIDE OF NEIGHBORHOOD. VIEW FACING NORTHWEST - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Intersection of Acacia Road and Brich Circle, Pearl City, Honolulu County, HI

  17. VIEW FROM ATOP ADJACENT RESIDENTIAL TOWER, SHOWING INTERSECTION OF ACACIA ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW FROM ATOP ADJACENT RESIDENTIAL TOWER, SHOWING INTERSECTION OF ACACIA ROAD WITH BIRCH CIRCLE. VIEW FACING NORTHEAST - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Intersection of Acacia Road and Brich Circle, Pearl City, Honolulu County, HI

  18. 3. View of side of house facing north from adjacent ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. View of side of house facing north from adjacent property. Original wood siding and trim is visible. Note: later addition to rear of house is shown in right side of photograph. - 322 South Fifteenth Street (House), Louisville, Jefferson County, KY

  19. 22. Float located adjacent to entry stair in filtration bed. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    22. Float located adjacent to entry stair in filtration bed. The float actuates a valve that maintains water level over the bed. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

  20. How subaerial salt extrusions influence water quality in adjacent aquifers

    NASA Astrophysics Data System (ADS)

    Mehdizadeh, Razieh; Zarei, Mehdi; Raeisi, Ezzat

    2015-12-01

    Brines supplied from salt extrusions cause significant groundwater salinization in arid and semi-arid regions where salt rock is exposed to dissolution by episodic rainfalls. Here we focus on 62 of the 122 diapirs of Hormuz salt emergent in the southern Iran. To consider managing the degradation effect that salt extrusions have on the quality of adjoining aquifers, it is first necessary to understand how they influence adjacent water resources. We evaluate here the impacts that these diapirs have on adjacent aquifers based on investigating their geomorphologies, geologies, hydrologies and hydrogeologies. The results indicate that 28/62 (45%) of our sample of salt diapirs have no significant impact on the quality of groundwater in adjoining aquifers (namely Type N), while the remaining 34/62 (55%) degrade nearby groundwater quality. We offer simple conceptual models that account for how brines flowing from each of these types of salt extrusions contaminate adjacent aquifers. We identify three main mechanisms that lead to contamination: surface impact (Type A), subsurface intrusion (Type B) and indirect infiltration (Type C). A combination of all these mechanisms degrades the water quality in nearby aquifers in 19/62 (31%) of the salt diapirs studied. Having characterized the mechanism(s) by which each diapir affects the adjacent aquifer, we suggest a few possible remediation strategies to be considered. For instance, engineering the surface runoff of diapirs Types A and C into nearby evaporation basins would improve groundwater quality.

  1. MTR COOLING TOWER. BASIN IS ADJACENT TO PUMP HOUSE. CAMERA ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    MTR COOLING TOWER. BASIN IS ADJACENT TO PUMP HOUSE. CAMERA FACES SOUTHEAST TOWARD NORTH SIDE OF PUMP HOUSE. INL NEGATIVE NO. 2690. Unknown Photographer, 6/1951. - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  2. 1. VIEW FROM SOUTHWEST SHOWING SOUTH (FRONT) ELEVATION, ADJACENT LOUGHRAN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. VIEW FROM SOUTHWEST SHOWING SOUTH (FRONT) ELEVATION, ADJACENT LOUGHRAN BUILDING (BASSIN'S RESTAURANT) (HABS No. DC-357), 501-511 14TH STREET (THE LOCKER ROOM) HABS No. DC-356) ON CORNER, AND MUNSEY BUILDING (HABS No. DC-358) - William J. Stone Building, 1345 E Street Northwest, Washington, District of Columbia, DC

  3. 2. VIEW FROM ROOFTOP OF BUILDING (MOTEL) ADJACENT TO TECHWOOD ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. VIEW FROM ROOFTOP OF BUILDING (MOTEL) ADJACENT TO TECHWOOD HOMES, LOOKING WEST. GEORGIA TECH DORMITORY BUILDING, 581-587 TECHWOOD DRIVE, IN FOREGROUND. - Techwood Homes (Public Housing), Bounded by North Avenue, Parker Street, William Street & Lovejoy Street, Atlanta, Fulton County, GA

  4. 7. VIEW OF WATER TREATMENT PLANT, ADJACENT TO THE COAL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. VIEW OF WATER TREATMENT PLANT, ADJACENT TO THE COAL CONVEYOR; IN THE DISTANCE IS THE FREQUENCY CHANGER HOUSE, WHICH IS ATTACHED TO SWITCH HOUSE NO. 1; LOOKING WEST. - Commonwealth Electric Company, Fisk Street Electrical Generating Station, 1111 West Cermak Avenue, Chicago, Cook County, IL

  5. Implementation of non-invasive brain physiological monitoring concepts.

    PubMed

    Ragauskas, Arminas; Daubaris, Gediminas; Ragaisis, Vytautas; Petkus, Vytautas

    2003-10-01

    The paper presents innovative methods and technology for non-invasive intracranial hemodynamics monitoring based on the measurement of brain parenchyma acoustic properties. The clinical investigation of new technology shows the similarity between the invasively recorded intracranial pressure (ICP) and non-invasively recorded intracranial blood volume (IBV) pulse waves, slow waves and slow trends under intensive care unit (ICU) conditions. Also, the applicability of the non-invasive IBV slow wave monitoring technique for cerebrovascular autoregulation non-invasive long-term monitoring is demonstrated by theoretical and experimental studies.

  6. Characterization of brain inflammation during primary amoebic meningoencephalitis.

    PubMed

    Cervantes-Sandoval, Isaac; Serrano-Luna, José de Jesús; García-Latorre, Ethel; Tsutsumi, Víctor; Shibayama, Mineko

    2008-09-01

    Naegleria fowleri is a free-living amoeba and the etiologic agent of primary amoebic meningoencephalitis (PAM). Trophozoites reach the brain by penetrating the olfactory epithelium, and invasion of the olfactory bulbs results in an intense inflammatory reaction. The contribution of the inflammatory response to brain damage in experimental PAM has not been delineated. Using both optical and electron microscopy, we analyzed the morphologic changes in the brain parenchyma due to inflammation during experimental PAM. Several N. fowleri trophozoites were observed in the olfactory bulbs 72 h post-inoculation, and the number of amoebae increased rapidly over the next 24 h. Eosinophils and neutrophils surrounding the amoebae were then noted at later times during infection. Electron microscopic examination of the increased numbers of neutrophils and the interactions with trophozoites indicated an active attempt to eliminate the amoebae. The extent of inflammation increased over time, with a predominant neutrophil response indicating important signs of damage and necrosis of the parenchyma. These data suggest a probable role of inflammation in tissue damage. To test the former hypothesis, we used CD38-/- knockout mice with deficiencies in chemotaxis to compare the rate of mortality with the parental strain, C57BL/6J. The results showed that inflammation and mortality were delayed in the knockout mice. Based on these results, we suggest that the host inflammatory response and polymorphonuclear cell lysis contribute to a great extent to the central nervous system tissue damage.

  7. Adrenomedullin and the blood-brain barrier.

    PubMed

    Kastin, A J; Akerstrom, V; Hackler, L; Pan, W

    2001-01-01

    Adrenomedullin (ADM) is present both in the periphery and brain. In addition to its peripheral effects, this peptide can exert central effects such as decreasing food ingestion. We used multiple-time regression analysis to determine that labeled ADM can cross from blood to brain with an apparent influx constant (K(I)) of 5.83 +/- 1.44 x 10(-4) ml/g-min, much faster than that of albumin, the vascular control. HPLC showed that almost all of the injected 125I-ADM in the brain was intact, and capillary depletion showed that it could reach the parenchyma of the brain. However, more 125I-ADM was reversibly associated with the brain vasculature than we have seen with any other peptide tested by these methods. After intracerebroventricular injection, 125I-ADM exited the brain with the bulk reabsorption of cerebrospinal fluid at an efflux rate comparable to that of albumin. Although there was no blood-to-brain saturation, in situ brain perfusion of 125I-ADM in blood-free physiological buffer showed self-inhibition by excess unlabeled ADM. This, along with evidence of the lack of protein binding shown by capillary zone electrophoresis, indicated competition for the binding site of ADM at the BBB. The low lipophilicity of ADM determined by the octanol/buffer partition coefficient was also consistent with the prominent reversible association of ADM with the vasculature of the BBB. This suggests a function for ADM at the cerebral blood vessels, such as altering cerebral blood flow and perfusion, without disruption of the BBB.

  8. Determination of regional brain temperature using proton magnetic resonance spectroscopy to assess brain-body temperature differences in healthy human subjects.

    PubMed

    Childs, Charmaine; Hiltunen, Yrjö; Vidyasagar, Rishma; Kauppinen, Risto A

    2007-01-01

    Proton magnetic resonance spectroscopy ((1)H MRS) was used to determine brain temperature in healthy volunteers. Partially water-suppressed (1)H MRS data sets were acquired at 3T from four different gray matter (GM)/white matter (WM) volumes. Brain temperatures were determined from the chemical-shift difference between the CH(3) of N-acetyl aspartate (NAA) at 2.01 ppm and water. Brain temperatures in (1)H MRS voxels of 2 x 2 x 2 cm(3) showed no substantial heterogeneity. The volume-averaged temperature from single-voxel spectroscopy was compared with body temperatures obtained from the oral cavity, tympanum, and temporal artery regions. The mean brain parenchyma temperature was 0.5 degrees C cooler than readings obtained from three extra-brain sites (P < 0.01). (1)H MRS imaging (MRSI) data were acquired from a slice encompassing the single-voxel volumes to assess the ability of spectroscopic imaging to determine regional brain temperature within the imaging slice. Brain temperature away from the center of the brain determined by MRSI differed from that obtained by single-voxel MRS in the same brain region, possibly due to a poor line width (LW) in MRSI. The data are discussed in the light of proposed brain-body temperature gradients and the use of (1)H MRSI to monitor brain temperature in pathologies, such as brain trauma.

  9. Trafficking of Endogenous Immunoglobulins by Endothelial Cells at the Blood-Brain Barrier

    PubMed Central

    Villaseñor, Roberto; Ozmen, Laurence; Messaddeq, Nadia; Grüninger, Fiona; Loetscher, Hansruedi; Keller, Annika; Betsholtz, Christer; Freskgård, Per-Ola; Collin, Ludovic

    2016-01-01

    The Blood-Brain Barrier (BBB) restricts access of large molecules to the brain. The low endocytic activity of brain endothelial cells (BECs) is believed to limit delivery of immunoglobulins (IgG) to the brain parenchyma. Here, we report that endogenous mouse IgG are localized within intracellular vesicles at steady state in BECs in vivo. Using high-resolution quantitative microscopy, we found a fraction of endocytosed IgG in lysosomes. We observed that loss of pericytes (key components of the BBB) in pdgf-bret/ret mice affects the intracellular distribution of endogenous mouse IgG in BECs. In these mice, endogenous IgG was not detected within lysosomes but instead accumulate at the basement membrane and brain parenchyma. Such IgG accumulation could be due to reduced lysosomal clearance and increased sorting to the abluminal membrane of BECs. Our results suggest that, in addition to low uptake from circulation, IgG lysosomal degradation may be a downstream mechanism by which BECs further restrict IgG access to the brain. PMID:27149947

  10. SU-E-T-56: Brain Metastasis Treatment Plans for Contrast-Enhanced Synchrotron Radiation Therapy

    SciTech Connect

    Obeid, L; Adam, J; Tessier, A; Vautrin, M; Benkebil, M; Sihanath, R

    2014-06-01

    Purpose: Iodine-enhanced radiotherapy is an innovative treatment combining the selective accumulation of an iodinated contrast agent in brain tumors with irradiations using monochromatic medium energy x-rays. The aim of this study is to compare dynamic stereotactic arc-therapy and iodineenhanced SSRT. Methods: Five patients bearing brain metastasis received a standard helical 3D-scan without iodine. A second scan was acquired 13 min after an 80 g iodine infusion. Two SSRT treatment plans (with/without iodine) were performed for each patient using a dedicated Monte Carlo (MC) treatment planning system (TPS) based on the ISOgray TPS. Ten coplanar beams (6×6 cm2, shaped with collimator) were simulated. MC statistical error objective was less than 5% in the 50% isodose. The dynamic arc-therapy plan was achieved on the Iplan Brainlab TPS. The treatment plan validation criteria were fixed such that 100% of the prescribed dose is delivered at the beam isocentre and the 70% isodose contains the whole target volume. The comparison elements were the 70% isodose volume, the average and maximum doses delivered to organs at risk (OAR): brainstem, optical nerves, chiasma, eyes, skull bone and healthy brain parenchyma. Results: The stereotactic dynamic arc-therapy remains the best technique in terms of dose conformation. Iodine-enhanced SSRT presents similar performances to dynamic arc-therapy with increased brainstem and brain parenchyma sparing. One disadvantage of SSRT is the high dose to the skull bone. Iodine accumulation in metastasis may increase the dose by 20–30%, allowing a normal tissue sparing effect at constant prescribed dose. Treatment without any iodine enhancement (medium-energy stereotactic radiotherapy) is not relevant with degraded HDVs (brain, parenchyma and skull bone) comparing to stereotactic dynamic arc-therapy. Conclusion: Iodine-enhanced SSRT exhibits a good potential for brain metastasis treatment regarding the dose distribution and OAR criteria.

  11. Blood-brain barrier transport kinetics of the cyclic depsipeptide mycotoxins beauvericin and enniatins.

    PubMed

    Taevernier, Lien; Bracke, Nathalie; Veryser, Lieselotte; Wynendaele, Evelien; Gevaert, Bert; Peremans, Kathelijne; De Spiegeleer, Bart

    2016-09-06

    The cyclic depsipeptide mycotoxins beauvericin and enniatins are capable of reaching the systemic circulation through various routes of exposure and are hence capable of exerting central nervous system (CNS) effects, if they are able to pass the blood-brain barrier (BBB), which was the main objective of this study. Quantification of the mycotoxins was performed using an in-house developed and validated bio-analytical UHPLC-MS/MS method. Prior to the BBB experiments, the metabolic stability of the mycotoxins was evaluated in vitro in mouse serum and brain homogenate. The BBB permeation kinetics of beauvericin and enniatins were studied using an in vivo mice model, applying multiple time regression for studying the blood-to-brain influx. Additionally, capillary depletion was applied to obtain the fraction of the peptides really entering the brain parenchyma and the fraction loosely adhered to the brain capillary wall. Finally, also the brain-to-blood efflux transport kinetics was studied. Metabolic stability data indicated that the investigated mycotoxins were stable during the duration of the in vivo study. The brain influx study showed that beauvericin and enniatins are able to cross the blood-brain barrier in mice: using the Gjedde-Patlak biphasic model, it was shown that all investigated mycotoxins exert a high initial influx rate into the brain (K1 ranging from 11 to 53μL/(g×min)), rapidly reaching a plateau. After penetration, the mycotoxins reached the brain parenchyma (95%) with only a limited amount residing in the capillaries (5%). Negligible efflux (<0.005min(-1)) from the brain was observed in the 15min post-intracerebroventricular injection.

  12. Surgical treatment of complex axis fractures with adjacent segment instability.

    PubMed

    Wang, Lei; Xia, Tian; Dong, Shuanghai; Zhao, Qinghua; Tian, Jiwei

    2012-03-01

    This study investigates the clinical and radiographic characteristics of complex axis fractures with adjacent segment instability and describes the outcome of surgical treatment. Twenty-one patients (14 male, seven female; mean age=34 years) with complex axis fractures and adjacent segment instability who were treated between August 2003 and June 2009 were retrospectively reviewed. Treatment selection was based on fracture type and stability of the upper cervical segments. All patients were immobilized with a hard collar for three months after surgery. The mean follow-up period was 12 months (range=6-36 months). No intraoperative surgery-related complications were observed and fusion was achieved in all patients. The outcome was excellent for 17 patients, good for two patients, fair for one patient, and poor for one patient. The upper cervical segments that can become unstable due to complex axis fractures include the atlantoaxial and C2-3 joints. Recommended surgical treatments produce good results.

  13. On the Circulation Manifold for Two Adjacent Lifting Sections

    NASA Technical Reports Server (NTRS)

    Zannetti, Luca; Iollo, Angelo

    1998-01-01

    The circulation functional relative to two adjacent lifting sections is studied for two cases. In the first case we consider two adjacent circles. The circulation is computed as a function of the displacement of the secondary circle along the axis joining the two centers and of the angle of attack of the secondary circle, The gradient of such functional is computed by deriving a set of elliptic functions with respect both to their argument and to their Period. In the second case studied, we considered a wing-flap configuration. The circulation is computed by some implicit mappings, whose differentials with respect to the variation of the geometrical configuration in the physical space are found by divided differences. Configurations giving rise to local maxima and minima in the circulation manifold are presented.

  14. Brain Diseases

    MedlinePlus

    The brain is the control center of the body. It controls thoughts, memory, speech, and movement. It regulates the function of many organs. When the brain is healthy, it works quickly and automatically. However, ...

  15. Brain Aneurysm

    MedlinePlus

    ... tests don't provide enough information. Screening for brain aneurysms The use of imaging tests to screen ... and occupational therapy to relearn skills. Treating unruptured brain aneurysms Surgical clipping or endovascular coiling can be ...

  16. Brain Development

    MedlinePlus

    ... developed the f… Series Healthy Minds: Nurturing Your Child's Development Each of these age-based handouts are based ... report from the National Academy of Sciences on child and brain development. Podcast Nurturing Brain Development From Birth to Three ...

  17. Brain Fog

    MedlinePlus

    ... friendships and relationships. • Take your body to the gym and don’t forget to visit the “BRAIN SPA” – both will improve brain function. • Recent scientific data show that longevity ...

  18. Brain Power.

    ERIC Educational Resources Information Center

    Albrecht, Karl

    2002-01-01

    Reviews significant findings of recent brain research, including the concept of five minds: automatic, subconscious, practical, creative, and spiritual. Suggests approaches to training the brain that are related to this hierarchy of thinking. (JOW)

  19. Osmium complex binding to mismatched methylcytosine: effect of adjacent bases.

    PubMed

    Nomura, Akiko; Tainaka, Kazuki; Okamoto, Akimitsu

    2009-01-01

    We investigated the efficiency of osmium complex formation at 5-methylcytosine in mismatched DNA duplexes. Osmium complexation was not observed in fully matched duplexes, whereas the complexation site and efficiency in mismatched duplexes depended on the 5'-neighboring base of the 5-methylcytosine. In particular, when the base adjacent to the 5' side of the mismatched base pair was thymine, a unique side reaction was observed. However, the mismatched base pairs did not influence the selectivity of osmium complexation with methylated DNA.

  20. Conference room 211, adjacent to commander's quarters, with vault door ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Conference room 211, adjacent to commander's quarters, with vault door at right. Projection area at center is equipped with automatic security drapes. Projection room uses a 45 degree mirror to reflect the image onto the frosted glass screen. Door on far left leads to display area senior battle staff viewing bridge, and the commander's quarters - March Air Force Base, Strategic Air Command, Combat Operations Center, 5220 Riverside Drive, Moreno Valley, Riverside County, CA

  1. 20. Interior view of fuel storage pit or vault adjacent ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    20. Interior view of fuel storage pit or vault adjacent to Test Cell 9 in Component Test Laboratory (T-27), looking west. Photograph shows upgraded instrumentation, piping, tanks, and technological modifications installed in 1997-99 to accommodate component testing requirements for the Atlas V missile. - Air Force Plant PJKS, Systems Integration Laboratory, Components Test Laboratory, Waterton Canyon Road & Colorado Highway 121, Lakewood, Jefferson County, CO

  2. Four-body central configurations with adjacent equal masses

    NASA Astrophysics Data System (ADS)

    Deng, Yiyang; Li, Bingyu; Zhang, Shiqing

    2017-04-01

    For any convex non-collinear central configuration of the planar Newtonian 4-body problem with adjacent equal masses m1 =m2 ≠m3 =m4, with equal lengths for the two diagonals, we prove it must possess a symmetry and must be an isosceles trapezoid; furthermore, which is also an isosceles trapezoid when the length between m1 and m4 equals the length between m2 and m3.

  3. Processing multiple non-adjacent dependencies: evidence from sequence learning.

    PubMed

    de Vries, Meinou H; Petersson, Karl Magnus; Geukes, Sebastian; Zwitserlood, Pienie; Christiansen, Morten H

    2012-07-19

    Processing non-adjacent dependencies is considered to be one of the hallmarks of human language. Assuming that sequence-learning tasks provide a useful way to tap natural-language-processing mechanisms, we cross-modally combined serial reaction time and artificial-grammar learning paradigms to investigate the processing of multiple nested (A(1)A(2)A(3)B(3)B(2)B(1)) and crossed dependencies (A(1)A(2)A(3)B(1)B(2)B(3)), containing either three or two dependencies. Both reaction times and prediction errors highlighted problems with processing the middle dependency in nested structures (A(1)A(2)A(3)B(3)_B(1)), reminiscent of the 'missing-verb effect' observed in English and French, but not with crossed structures (A(1)A(2)A(3)B(1)_B(3)). Prior linguistic experience did not play a major role: native speakers of German and Dutch-which permit nested and crossed dependencies, respectively-showed a similar pattern of results for sequences with three dependencies. As for sequences with two dependencies, reaction times and prediction errors were similar for both nested and crossed dependencies. The results suggest that constraints on the processing of multiple non-adjacent dependencies are determined by the specific ordering of the non-adjacent dependencies (i.e. nested or crossed), as well as the number of non-adjacent dependencies to be resolved (i.e. two or three). Furthermore, these constraints may not be specific to language but instead derive from limitations on structured sequence learning.

  4. 38. VIEW OF COTTRELL MAGNETIC IMPULSE GENERATOR ADJACENT TO SIX ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    38. VIEW OF COTTRELL MAGNETIC IMPULSE GENERATOR ADJACENT TO SIX GAP ROTARY RECTIFIER. THIS UNIT GENERATED A MAGNETIC PULSE WHICH WAS TRANSMITTED TO THE COLLECTION PLATES IN THE ELECTROSTATIC PRECIPITATOR CHAMBER. THESE PERIODIC PULSES VIBRATE THE PLATES AND CAUSE PRECIPITATED ARTICLES OF SMOKE AND FLY ASH TO FALL TO THE BOTTOM OF THE PRECIPITATOR CHAMBER. - New York, New Haven & Hartford Railroad, Cos Cob Power Plant, Sound Shore Drive, Greenwich, Fairfield County, CT

  5. Characterization of AgMaT2, a plasma membrane mannitol transporter from celery, expressed in phloem cells, including phloem parenchyma cells.

    PubMed

    Juchaux-Cachau, Marjorie; Landouar-Arsivaud, Lucie; Pichaut, Jean-Philippe; Campion, Claire; Porcheron, Benoit; Jeauffre, Julien; Noiraud-Romy, Nathalie; Simoneau, Philippe; Maurousset, Laurence; Lemoine, Rémi

    2007-09-01

    A second mannitol transporter, AgMaT2, was identified in celery (Apium graveolens L. var. dulce), a species that synthesizes and transports mannitol. This transporter was successfully expressed in two different heterologous expression systems: baker's yeast (Saccharomyces cerevisiae) cells and tobacco (Nicotiana tabacum) plants (a non-mannitol-producing species). Data indicated that AgMaT2 works as an H(+)/mannitol cotransporter with a weak selectivity toward other polyol molecules. When expressed in tobacco, AgMaT2 decreased the sensitivity to the mannitol-secreting pathogenic fungi Alternaria longipes, suggesting a role for polyol transporters in defense mechanisms. In celery, in situ hybridization showed that AgMaT2 was expressed in the phloem of leaflets, petioles from young and mature leaves, floral stems, and roots. In the phloem of petioles and leaflets, AgMaT2, as localized with specific antibodies, was present in the plasma membrane of three ontologically related cell types: sieve elements, companion cells, and phloem parenchyma cells. These new data are discussed in relation to the physiological role of AgMaT2 in regulating mannitol fluxes in celery petioles.

  6. Characterization of AgMaT2, a Plasma Membrane Mannitol Transporter from Celery, Expressed in Phloem Cells, Including Phloem Parenchyma Cells[OA

    PubMed Central

    Juchaux-Cachau, Marjorie; Landouar-Arsivaud, Lucie; Pichaut, Jean-Philippe; Campion, Claire; Porcheron, Benoit; Jeauffre, Julien; Noiraud-Romy, Nathalie; Simoneau, Philippe; Maurousset, Laurence; Lemoine, Rémi

    2007-01-01

    A second mannitol transporter, AgMaT2, was identified in celery (Apium graveolens L. var. dulce), a species that synthesizes and transports mannitol. This transporter was successfully expressed in two different heterologous expression systems: baker's yeast (Saccharomyces cerevisiae) cells and tobacco (Nicotiana tabacum) plants (a non-mannitol-producing species). Data indicated that AgMaT2 works as an H+/mannitol cotransporter with a weak selectivity toward other polyol molecules. When expressed in tobacco, AgMaT2 decreased the sensitivity to the mannitol-secreting pathogenic fungi Alternaria longipes, suggesting a role for polyol transporters in defense mechanisms. In celery, in situ hybridization showed that AgMaT2 was expressed in the phloem of leaflets, petioles from young and mature leaves, floral stems, and roots. In the phloem of petioles and leaflets, AgMaT2, as localized with specific antibodies, was present in the plasma membrane of three ontologically related cell types: sieve elements, companion cells, and phloem parenchyma cells. These new data are discussed in relation to the physiological role of AgMaT2 in regulating mannitol fluxes in celery petioles. PMID:17631523

  7. Immunolocalization of Solanaceous SUT1 Proteins in Companion Cells and Xylem Parenchyma: New Perspectives for Phloem Loading and Transport1[W][OA

    PubMed Central

    Schmitt, Bianca; Stadler, Ruth; Sauer, Norbert

    2008-01-01

    Leaf sucrose (Suc) transporters are essential for phloem loading and long-distance partitioning of assimilates in plants that load their phloem from the apoplast. Suc loading into the phloem is indispensable for the generation of the osmotic potential difference that drives phloem bulk flow and is central for the long-distance movement of phloem sap compounds, including hormones and signaling molecules. In previous analyses, solanaceous SUT1 Suc transporters from tobacco (Nicotiana tabacum), potato (Solanum tuberosum), and tomato (Solanum lycopersicum) were immunolocalized in plasma membranes of enucleate sieve elements. Here, we present data that identify solanaceous SUT1 proteins with high specificity in phloem companion cells. Moreover, comparisons of SUT1 localization in the abaxial and adaxial phloem revealed higher levels of SUT1 protein in the abaxial phloem of all three solanaceous species, suggesting different physiological roles for these two types of phloem. Finally, SUT1 proteins were identified in files of xylem parenchyma cells, mainly in the bicollateral veins. Together, our data provide new insight into the role of SUT1 proteins in solanaceous species. PMID:18614713

  8. Phloem as Capacitor: Radial Transfer of Water into Xylem of Tree Stems Occurs via Symplastic Transport in Ray Parenchyma[OPEN

    PubMed Central

    Renard, Justine; Tjoelker, Mark G.; Salih, Anya

    2015-01-01

    The transfer of water from phloem into xylem is thought to mitigate increasing hydraulic tension in the vascular system of trees during the diel cycle of transpiration. Although a putative plant function, to date there is no direct evidence of such water transfer or the contributing pathways. Here, we trace the radial flow of water from the phloem into the xylem and investigate its diel variation. Introducing a fluorescent dye (0.1% [w/w] fluorescein) into the phloem water of the tree species Eucalyptus saligna allowed localization of the dye in phloem and xylem tissues using confocal laser scanning microscopy. Our results show that the majority of water transferred between the two tissues is facilitated via the symplast of horizontal ray parenchyma cells. The method also permitted assessment of the radial transfer of water during the diel cycle, where changes in water potential gradients between phloem and xylem determine the extent and direction of radial transfer. When injected during the morning, when xylem water potential rapidly declined, fluorescein was translocated, on average, farther into mature xylem (447 ± 188 µm) compared with nighttime, when xylem water potential was close to zero (155 ± 42 µm). These findings provide empirical evidence to support theoretical predictions of the role of phloem-xylem water transfer in the hydraulic functioning of plants. This method enables investigation of the role of phloem tissue as a dynamic capacitor for water storage and transfer and its contribution toward the maintenance of the functional integrity of xylem in trees. PMID:25588734

  9. Xylem ray parenchyma cells in boreal hardwood species respond to subfreezing temperatures by deep supercooling that is accompanied by incomplete desiccation.

    PubMed

    Kuroda, Katsushi; Kasuga, Jun; Arakawa, Keita; Fujikawa, Seizo

    2003-02-01

    It has been accepted that xylem ray parenchyma cells (XRPCs) in hardwood species respond to subfreezing temperatures either by deep supercooling or by extracellular freezing. Present study by cryo-scanning electron microscopy examined the freezing responses of XRPCs in five boreal hardwoods: Salix sachalinensis Fr. Schmit, Populus sieboldii Miq., Betula platyphylla Sukat. var japonica Hara, Betula pubescens Ehrh., and red osier dogwood (Cornus sericea), in which XRPCs have been reported to respond by extracellular freezing. Cryo-scanning electron microscopy observations revealed that slow cooling of xylem to -80 degrees C resulted in intracellular freezing in the majority of XRPCs in S. sachalinensis, an indication that these XRPCs had been deep supercooled. In contrast, in the majority of XRPCs in P. sieboldii, B. platyphylla, B. pubescens, and red osier dogwood, slow cooling to -80 degrees C produced slight cytorrhysis without clear evidence of intracellular freezing, suggesting that these XRPCs might respond by extracellular freezing. In these XRPCs exhibited putative extracellular freezing; however, deep etching revealed the apparent formation of intracellular ice crystals in restricted local areas. To confirm the occurrence of intracellular freezing, we rewarmed these XRPCs after cooling and observed very large intracellular ice crystals as a result of the recrystallization. Thus, the XRPCs in all the boreal hardwoods that we examined responded by deep supercooling that was accompanied with incomplete desiccation. From these results, it seems possible that limitations to the deep-supercooling ability of XRPCs might be a limiting factor for adaptation of hardwoods to cold climates.

  10. The delivery of salts to the xylem. Three types of anion conductance in the plasmalemma of the xylem parenchyma of roots of barley.

    PubMed

    Köhler, B; Raschke, K

    2000-01-01

    To explore possible pathways for anions to enter the xylem in the root during the transport of salts to the shoot, we used the patch-clamp method on protoplasts prepared from the xylem parenchyma of barley (Hordeum vulgare L.) plants. K(+) currents were suppressed by tetraethylammonium or N-methylglucamine in the solutions in the pipette and the bath, and the permeating anions were Cl(-) or NO(3)(-). We recorded the activities of three distinct anion conductances: (a) an inwardly rectifying anion channel (X-IRAC), characterized by activation at hyperpolarization and open times of up to several seconds; (b) a quickly activating anion conductance (X-QUAC), important for anion efflux at voltages between -50 mV and the equilibrium potential of the prevailing anion; and (c) a slowly activating anion conductance (X-SLAC), activating above -100 mV. Both X-IRAC and X-QUAC were permeable for Cl(-) and NO(3)(-); X-QUAC was also permeable for malate. The occurrence of X-IRAC became more frequent with an increase in cytoplasmic Ca(2+), while the occurrence of X-QUAC decreased. Anion currents through X-SLAC, and particularly through X-QUAC, were estimated to be large enough to account for reported rates of xylem loading, which is in accordance with the notion that xylem loading is a passive process.

  11. Predicting Agenesis of the Mandibular Second Premolar from Adjacent Teeth

    PubMed Central

    2015-01-01

    Early diagnosis of agenesis of the mandibular second premolar (P2) enhances management of the dental arch in the growing child. The aim of this study was to explore the relationship in the development of the mandibular first molar (M1) and first premolar (P1) at early stages of P2 (second premolar). Specifically, we ask if the likelihood of P2 agenesis can be predicted from adjacent developing teeth. We selected archived dental panoramic radiographs with P2 at crown formation stages (N = 212) and calculated the likelihood of P2 at initial mineralisation stage ‘Ci’ given the tooth stage of adjacent teeth. Our results show that the probability of observing mandibular P2 at initial mineralisation stage ‘Ci’ decreased as both the adjacent P1 and M1 matured. The modal stage at P2 ‘Ci’ was P1 ‘Coc’ (cusp outline complete) and M1 ‘Crc’ (crown complete). Initial mineralisation of P2 was observed up to P1 ‘Crc’ and M1 stage ‘R½’ (root half). The chance of observing P2 at least ‘Coc’ (coalescence of cusps) was considerably greater prior to these threshold stages compared to later stages of P1 and M1. These findings suggest that P2 is highly unlikely to develop if P1 is beyond ‘Crc’ and M1 is beyond ‘R½’. PMID:26673218

  12. Adjacent Segment Disease in the Cervical and Lumbar Spine.

    PubMed

    Tobert, Daniel G; Antoci, Valentin; Patel, Shaun P; Saadat, Ehsan; Bono, Christopher M

    2017-04-01

    Adjacent segment disease (ASD) is disappointing long-term outcome for both the patient and clinician. In contrast to adjacent segment degeneration, which is a common radiographic finding, ASD is less common. The incidence of ASD in both the cervical and lumbar spine is between 2% and 4% per year, and ASD is a significant contributor to reoperation rates after spinal arthrodesis. The etiology of ASD is multifactorial, stemming from existing spondylosis at adjacent levels, predisposed risk to degenerative changes, and altered biomechanical forces near a previous fusion site. Numerous studies have sought to identify both patient and surgical risk factors for ASD, but a consistent, sole predictor has yet to be found. Spinal arthroplasty techniques seek to preserve physiological biomechanics, thereby minimizing the risk of ASD, and long-term clinical outcome studies will help quantify its efficacy. Treatment strategies for ASD are initially nonoperative, provided a progressive neurological deficit is not present. The spine surgeon is afforded many surgical strategies once operative treatment is elected. The goal of this manuscript is to consider the etiologies of ASD, review its manifestations, and offer an approach to treatment.

  13. Fouling assemblages on offshore wind power plants and adjacent substrata

    NASA Astrophysics Data System (ADS)

    Wilhelmsson, Dan; Malm, Torleif

    2008-09-01

    A significant expansion of offshore wind power is expected in the near future, with thousands of turbines in coastal waters, and various aspects of how this may influence the coastal ecology including disturbance effects from noise, shadows, electromagnetic fields, and changed hydrological conditions are accordingly of concern. Further, wind power plants constitute habitats for a number of organisms, and may locally alter assemblage composition and biomass of invertebrates, algae and fish. In this study, fouling assemblages on offshore wind turbines were compared to adjacent hard substrate. Influences of the structures on the seabed were also investigated. The turbines differed significantly from adjacent boulders in terms of assemblage composition of epibiota and motile invertebrates. Species number and Shannon-Wiener diversity were, also, significantly lower on the wind power plants. It was also indicated that the turbines might have affected assemblages of invertebrates and algae on adjacent boulders. Off shore wind power plant offer atypical substrates for fouling assemblages in terms of orientation, depth range, structure, and surface texture. Some potential ecological implications of the addition of these non-natural habitats for coastal ecology are discussed.

  14. Perceptual processing of adjacent and nonadjacent tactile nontargets.

    PubMed

    Evans, P M; Craig, J C; Rinker, M A

    1992-11-01

    Previous research has shown that subjects appear unable to restrict processing to a single finger and ignore a stimulus presented to an adjacent finger. Furthermore, the evidence suggests that, at least for moving stimuli, an adjacent nontarget is fully processed to the level of incipient response activation. The present study replicated and expanded upon these original findings. The results of Experiment 1 showed that an equally large response-competition effect occurred when the nontarget was presented to adjacent and nonadjacent fingers (on the same hand). The results of Experiment 2 showed that the effects observed in Experiment 1 (and in previous studies) were also obtained with stationary stimuli. Although small, there was some indication in the results of Experiment 2 that interference may dissipate more rapidly with distance with stationary stimuli. An additional finding was that interference effects were observed in both experiments with temporal separations between the target and nontarget of up to 100 msec. In Experiment 3, target and nontarget stimuli were presented to opposite hands. Although reduced, interference was still evident with target and nontarget stimuli presented to opposite hands. Varying the physical distance between hands did not produce any change in the amount of interference. The results suggest that the focus of attention on the skin extends nearly undiminished across the fingers of one hand and is not dependent upon the physical distance between sites of stimulation.

  15. Using BRDFs for accurate albedo calculations and adjacency effect corrections

    SciTech Connect

    Borel, C.C.; Gerstl, S.A.W.

    1996-09-01

    In this paper the authors discuss two uses of BRDFs in remote sensing: (1) in determining the clear sky top of the atmosphere (TOA) albedo, (2) in quantifying the effect of the BRDF on the adjacency point-spread function and on atmospheric corrections. The TOA spectral albedo is an important parameter retrieved by the Multi-angle Imaging Spectro-Radiometer (MISR). Its accuracy depends mainly on how well one can model the surface BRDF for many different situations. The authors present results from an algorithm which matches several semi-empirical functions to the nine MISR measured BRFs that are then numerically integrated to yield the clear sky TOA spectral albedo in four spectral channels. They show that absolute accuracies in the albedo of better than 1% are possible for the visible and better than 2% in the near infrared channels. Using a simplified extensive radiosity model, the authors show that the shape of the adjacency point-spread function (PSF) depends on the underlying surface BRDFs. The adjacency point-spread function at a given offset (x,y) from the center pixel is given by the integral of transmission-weighted products of BRDF and scattering phase function along the line of sight.

  16. Brain Aneurysm

    MedlinePlus

    A brain aneurysm is an abnormal bulge or "ballooning" in the wall of an artery in the brain. They are sometimes called berry aneurysms because they ... often the size of a small berry. Most brain aneurysms produce no symptoms until they become large, ...

  17. Brain Lesions

    MedlinePlus

    ... MRI scans, brain lesions appear as dark or light spots that don't look like normal brain tissue. Usually, a brain lesion is an incidental finding unrelated to the condition or symptom that led to the imaging test in the first place. ...

  18. The Brain.

    ERIC Educational Resources Information Center

    Hubel, David H.

    1979-01-01

    This article on the brain is part of an entire issue about neurobiology and the question of how the human brain works. The brain as an intricate tissue composed of cells is discussed based on the current knowledge and understanding of its composition and structure. (SA)

  19. Left Brain. Right Brain. Whole Brain

    ERIC Educational Resources Information Center

    Farmer, Lesley S. J.

    2004-01-01

    As the United States student population is becoming more diverse, library media specialists need to find ways to address these distinctive needs. However, some of these differences transcend culture, touching on variations in the brain itself. Most people have a dominant side of the brain, which can affect their personality and learning style.…

  20. Role of nuclear receptors in the regulation of drug transporters in the brain.

    PubMed

    Chan, Gary N Y; Hoque, Md Tozammel; Bendayan, Reina

    2013-07-01

    ATP-binding cassette membrane-associated drug efflux transporters and solute carrier influx transporters, expressed at the blood-brain barrier, blood-cerebrospinal fluid barrier, and in brain parenchyma, are important determinants of drug disposition in the central nervous system. Targeting the regulatory pathways that govern the expression of these transporters could provide novel approaches to selectively alter drug permeability into the brain. Nuclear receptors are ligand-activated transcription factors which regulate the gene expression of several metabolic enzymes and drug efflux/influx transporters. Although efforts have primarily been focused on investigating these regulatory pathways in peripheral organs (i.e., liver and intestine), recent findings demonstrate their significance in the brain. This review addresses the role of nuclear receptors in the regulation of drug transporter functional expression in the brain. An in-depth understanding of these pathways could guide the development of novel pharmacotherapy with either enhanced efficacy in the central nervous system or minimal associated neurotoxicity.

  1. Brain to music to brain!

    PubMed

    Azizi, S Ausim

    2009-07-31

    It has been implicitly understood that culture and music as collective products of human brain in turn influence the brain itself. Now, imaging and anatomical data add substance to this notion. The impact of playing piano on the brain of musicians and its possible effects on cultural and neurological evolution are briefly discussed.

  2. The Involvement of Pial Microvessels in Leukocyte Invasion after Mild Traumatic Brain Injury

    PubMed Central

    Shan, Rongzi; Thomasian, Nicole; Chodobski, Adam

    2016-01-01

    The pathophysiological mechanisms underlying mild traumatic brain injury (mTBI) are not well understood, but likely involve neuroinflammation. Here the controlled cortical impact model of mTBI in rats was used to test this hypothesis. Mild TBI caused a rapid (within 6 h post-mTBI) upregulation of synthesis of TNF-α and IL-1β in the cerebral cortex and hippocampus, followed by an increase in production of neutrophil (CXCL1–3) and monocyte (CCL2) chemoattractants. While astrocytes were not a significant source of CXC chemokines, they highly expressed CCL2. An increase in production of CXC chemokines coincided with the influx of neutrophils into the injured brain. At 6 h post-mTBI, we observed a robust influx of CCL2-expressing neutrophils across pial microvessels into the subarachnoid space (SAS) near the injury site. Mild TBI was not accompanied by any significant influx of neutrophils into the brain parenchyma until 24 h after injury. This was associated with an early induction of expression of intercellular adhesion molecule 1 on the endothelium of the ipsilateral pial, but not intraparenchymal, microvessels. At 6 h post-mTBI, we also observed a robust influx of neutrophils into the ipsilateral cistern of velum interpositum (CVI), a slit-shaped cerebrospinal fluid space located above the 3rd ventricle with highly vascularized pia mater. From SAS and CVI, neutrophils appeared to move along the perivascular spaces to enter the brain parenchyma. The monocyte influx was not observed until 24 h post-mTBI, and these inflammatory cells predominantly entered the ipsilateral SAS and CVI, with a limited invasion of brain parenchyma. These observations indicate that the endothelium of pial microvessels responds to injury differently than that of intraparenchymal microvessels, which may be associated with the lack of astrocytic ensheathment of cerebrovascular endothelium in pial microvessels. These findings also suggest that neuroinflammation represents the potential

  3. Brain abscess and granuloma formation as late complications of retained ventricular catheter.

    PubMed

    Khan, S A; Gretchel, A; Govender, H; Hartzenberg, B

    2009-01-01

    This report presents a rare complication of ventriculoperitoneal shunt, delayed development of brain abscess and foreign body granuloma formation adjacent to the intraventricular catheter. Both the complications occurring in the same patient is unusual.

  4. Investigations of initial airtightness after non-anatomic resection of lung parenchyma using a thulium-doped laser with different optical fibres.

    PubMed

    Kirschbaum, Andreas; Höchsmann, N; Steinfeldt, T; Seyfer, P; Pehl, A; Bartsch, D K; Palade, E

    2016-08-01

    Lung metastases in healthy patients should be removed non-anatomically whenever possible. This can be done with a laser. Lung parenchyma can be cut very well, because of its high energy absorption at a wavelength of 1940 nm. A coagulation layer is created on the resected surface. It is not clear, whether this surface also needs to be sutured to ensure that it remains airtight even at higher ventilation pressures. It would be helpful, if suturing could be avoided, because the lung can become too puckered, especially with multiple resections, resulting in considerable restriction. We carried out our experiments on isolated and ventilated paracardiac lung lobes of pigs. Non-anatomic resection was carried out reproducibly using three different thulium laser fibres (230, 365 and 600 μm) at two different laser power levels (10 W, 30 W) and three different resection depths (0.5, 1.0 and 2.0 cm). Initial airtightness was investigated while ventilating at normal frequency. We also investigated the bursting pressures of the resected areas by increasing the inspiratory pressure. When 230- and 365-μm fibres were used with a power of 10 W, 70 % of samples were initially airtight up to a resection depth of 1 cm. This rate fell at depths of up to 2 cm. All resected surfaces remained airtight during ventilation when 600-μm fibres were used at both laser power levels (10 and 30 W). The bursting pressures achieved with 600-μm fibres were higher than with the other fibres used: 0.5 cm, 41.6 ± 3.2 mbar; 1 cm, 38.2 ± 2.5 mbar; 2 cm, 33.7 ± 4.8 mbar. As laser power and thickness of laser fibre increased, so the coagulation zone became thicker. With a 600-μm fibre, it measured 145.0 ± 8.2 μm with 10 W power and 315.5 ± 6.4 μm with 30 W power. Closure with sutures after non-anatomic resection of lung parenchyma is not necessary when a thulium laser is used provided a 600-μm fibre and adequate laser power (30 W) are employed. At deeper

  5. Impact of adjacent land use on coastal wetland sediments.

    PubMed

    Karstens, Svenja; Buczko, Uwe; Jurasinski, Gerald; Peticzka, Robert; Glatzel, Stephan

    2016-04-15

    Coastal wetlands link terrestrial with marine ecosystems and are influenced from both land and sea. Therefore, they are ecotones with strong biogeochemical gradients. We analyzed sediment characteristics including macronutrients (C, N, P, K, Mg, Ca, S) and heavy metals (Mn, Fe, Cu, Zn, Al, Co, Cr, Ni) of two coastal wetlands dominated by Phragmites australis at the Darss-Zingst Bodden Chain, a lagoon system at the Southern Baltic Sea, to identify the impact of adjacent land use and to distinguish between influences from land or sea. In the wetland directly adjacent to cropland (study site Dabitz) heavy metal concentrations were significantly elevated. Fertilizer application led to heavy metal accumulation in the sediments of the adjacent wetland zones. In contrast, at the other study site (Michaelsdorf), where the hinterland has been used as pasture, heavy metal concentrations were low. While the amount of macronutrients was also influenced by vegetation characteristics (e.g. carbon) or water chemistry (e.g. sulfate), the accumulation of heavy metals is regarded as purely anthropogenic influence. A principal component analysis (PCA) based on the sediment data showed that the wetland fringes of the two study sites are not distinguishable, neither in their macronutrient status nor in their concentrations of heavy metals, whereas the interior zones exhibit large differences in terms of heavy metal concentrations. This suggests that seaside influences are minor compared to influences from land. Altogether, heavy metal concentrations were still below national precautionary and action values. However, if we regard the macronutrient and heavy metal concentrations in the wetland fringes as the natural background values, an accumulation of trace elements from agricultural production in the hinterland is apparent. Thus, coastal wetlands bordering croplands may function as effective pollutant buffers today, but the future development has to be monitored closely to avoid

  6. Adjacent segment disease and C-ADR: promises fulfilled?

    PubMed Central

    Riew, K Daniel; Schenk-Kisser, Jeannette M.; Skelly, Andrea C.

    2012-01-01

    Study design: Systematic review. Clinical question: Do the rates and timing of adjacent segment disease (ASD) differ between cervical total disc arthroplasty (C-ADR) and anterior cervical discectomy and fusion (ACDF) in patients treated for cervical degenerative disc disease? Methods: A systematic search of MEDLINE/PubMed and bibliographies of key articles was done to identify studies with long-term follow-up for symptomatic and/or radiographic ASD comparing C-ADR with fusion for degenerative disc disease of the cervical spine. The focus was on studies with longer follow-up (48–60 months) of primary US Food and Drug Administration trials of Prestige ST, Prodisc-C, and Bryan devices as available. Trials of other discs with a minimum of 24 months follow-up were considered for inclusion. Studies evaluating lordosis/angle changes at adjacent segments and case series were excluded. Results: From 14 citations identified, four reports from three randomized controlled trials and four nonrandomized studies are summarized. Risk differences between C-ADR and ACF for symptomatic ASD were 1.5%–2.3% and were not significant across RCT reports. Time to development of ASD did not significantly differ between treatments. Rates of radiographic ASD were variable. No meaningful comparison of ASD rates based on disc design was possible. No statistical differences in adjacent segment range of motion were noted between treatment groups. Conclusion: Our analysis reveals that, to date, there is no evidence that arthroplasty decreases ASD compared with ACDF; the promise of arthroplasty decreasing ASD has not been fulfilled. PMID:23236312

  7. Change of supercooling capability in solutions containing different kinds of ice nucleators by flavonol glycosides from deep supercooling xylem parenchyma cells in trees.

    PubMed

    Kuwabara, Chikako; Kasuga, Jun; Wang, Donghui; Fukushi, Yukiharu; Arakawa, Keita; Koyama, Toshie; Inada, Takaaki; Fujikawa, Seizo

    2011-12-01

    Deep supercooling xylem parenchyma cells (XPCs) in Katsura tree contain flavonol glycosides with high supercooling-facilitating capability in solutions containing the ice nucleation bacterium (INB) Erwinia ananas, which is thought to have an important role in deep supercooling of XPCs. The present study, in order to further clarify the roles of these flavonol glycosides in deep supercooling of XPCs, the effects of these supercooling-facilitating (anti-ice nucleating) flavonol glycosides, kaempferol 3-O-β-D-glucopyranoside (K3Glc), kaempferol 7-O-β-D-glucopyranoside (K7Glc) and quercetin 3-O-β-D-glucopyranoside (Q3Glc), in buffered Milli-Q water (BMQW) containing different kinds of ice nucleators, including INB Xanthomonas campestris, silver iodide and phloroglucinol, were examined by a droplet freezing assay. The results showed that all of the flavonol glycosides promoted supercooling in all solutions containing different kinds of ice nucleators, although the magnitudes of supercooling capability of each flavonol glycoside changed in solutions containing different kinds of ice nucleators. On the other hand, these flavonol glycosides exhibited complicated nucleating reactions in BMQW, which did not contain identified ice nucleators but contained only unidentified airborne impurities. Q3Glc exhibited both supercooling-facilitating and ice nucleating capabilities depending on the concentrations in such water. Both K3Glc and K7Glc exhibited only ice nucleation capability in such water. It was also shown by an emulsion freezing assay in BMQW that K3Glc and Q3Glc had no effect on homogeneous ice nucleation temperature, whereas K7Glc increased ice nucleation temperature. The results indicated that each flavonol glycoside affected ice nucleation by very complicated and varied reactions. More studies are necessary to determine the exact roles of these flavonol glycosides in deep supercooling of XPCs in which unidentified heterogeneous ice nucleators may exist.

  8. Long-lasting morphofunctional remodelling of liver parenchyma and stroma after a single exposure to low and moderate doses of cadmium in rats

    PubMed Central

    Cupertino, Marli C; Costa, Kyvia L C; Santos, Daiane C M; Novaes, Rômulo D; Condessa, Suellen S; Neves, Ana C; Oliveira, Juraci A; Matta, Sérgio L P

    2013-01-01

    Frequent exposure to cadmium (Cd) in low doses is common; however, the long-lasting effects of this exposure are still poorly understood. Therefore in this study we have evaluated long-lasting hepatic morphofunctional adaptations in rats exposed to low and moderate doses of Cd. Five experimental groups were tested: control (0.9% saline) and other four receiving single intraperitoneal doses of 0.67, 0.74, 0.86 and 1.1 mg of Cd/kg. The animals were killed after eight weeks and the following parameters were analysed: biometrics, oedema, Cd bio-accumulation, collagen, glycogen, lipid droplets, superoxide dismutase (SOD) and catalase (CAT), serum transaminases, liver histopathology and stereology. In all groups exposed to Cd there was significant increase in SOD and CAT activities, ALP levels, proportion of binucleated hepatocytes, nuclei/cytoplasm ratio, macrophages (Kupffer cells) and collagen fibres. In these groups, glycogen accumulation by hepatocytes and the proportion of sinusoidal capillaries were significantly reduced compared with controls. The liver somatic index was increased, and liver oedema was evident in animals exposed to higher dose of Cd. Areas of necrosis were found in animals exposed to the three highest doses. These results indicate that Cd is an extremely toxic bioactive heavy metal, which even at low doses is able to disrupt liver homeostasis. At low and moderate doses, Cd exposure induces morphofunctional pathological remodelling of the hepatic stroma and parenchyma, which remain active after eight weeks. In response to injury, the liver tissue triggers a reactive process by enhancing activation of antioxidant enzymes and collagenogenesis. PMID:24020407

  9. CLOUD PEAK PRIMITIVE AREA AND ADJACENT AREAS, WYOMING.

    USGS Publications Warehouse

    Kiilsgaard, Thor H.; Patten, Lowell L.

    1984-01-01

    The results of a mineral survey of the Cloud Peak Primitive Area and adjacent areas in Wyoming indicated little promise for the occurrence of mineral resources. There are some prospect workings, particularly in the northern part of the area, but in none of them were there indications that ore had been mined. Samples from the workings, from nearby rocks and sediments from streams that drain the area did not yield any metal values of significance. The crystalline rocks that underlie the area do not contain oil and gas or coal, products that are extracted from the younger rocks that underlie basins on both sides of the study area.

  10. Stereoselective Organocatalytic Synthesis of Oxindoles with Adjacent Tetrasubstituted Stereocenters.

    PubMed

    Engl, Oliver D; Fritz, Sven P; Wennemers, Helma

    2015-07-06

    Oxindoles with adjacent tetrasubstituted stereocenters were obtained in high yields and stereoselectivities by organocatalyzed conjugate addition reactions of monothiomalonates (MTMs) to isatin-derived N-Cbz ketimines. The method requires only a low catalyst loading (2 mol %) and proceeds under mild reaction conditions. Both enantiomers are accessible in good yields and excellent stereoselectivities by using either Takemoto's catalyst or a cinchona alkaloid derivative. The synthetic methodology allowed establishment of a straightforward route to derivatives of the gastrin/cholecystokinin-B receptor antagonist AG-041R.

  11. Interaction of Cracks Between Two Adjacent Indents in Glass

    NASA Technical Reports Server (NTRS)

    Choi, S. R.; Salem, J. A.

    1993-01-01

    Experimental observations of the interaction behavior of cracks between two adjacent indents were made using an indentation technique in soda-lime glass. It was specifically demonstrated how one indent crack initiates and propagates in the vicinity of another indent crack. Several types of crack interactions were examined by changing the orientation and distance of one indent relative to the other. It was found that the residual stress field produced by elastic/plastic indentation has a significant influence on controlling the mode of crack interaction. The interaction of an indent crack with a free surface was also investigated for glass and ceramic specimens.

  12. Astronaut Charles Duke stands at rock adjacent to 'House Rock'

    NASA Technical Reports Server (NTRS)

    1972-01-01

    Astronaut Charles M. Duke Jr., Apollo 16 lunar module pilot, stands at a rock adjacent (south) to the huge 'House Rock' (barely out of view at right edge). Note shadow at extreme right center where the two moon-exploring crewmen of the mission sampled what they referred to as the 'eastwest split of House Rock' or the open space between this rock and 'House Rock'. Duke has a sample bag in his hand, and a lunar surface rake leans against the large boulder.

  13. Empires and percolation: stochastic merging of adjacent regions

    NASA Astrophysics Data System (ADS)

    Aldous, D. J.; Ong, J. R.; Zhou, W.

    2010-01-01

    We introduce a stochastic model in which adjacent planar regions A, B merge stochastically at some rate λ(A, B) and observe analogies with the well-studied topics of mean-field coagulation and of bond percolation. Do infinite regions appear in finite time? We give a simple condition on λ for this hegemony property to hold, and another simple condition for it to not hold, but there is a large gap between these conditions, which includes the case λ(A, B) ≡ 1. For this case, a non-rigorous analytic argument and simulations suggest hegemony.

  14. Brain surgery - discharge

    MedlinePlus

    ... to take these medicines. If you had a brain aneurysm , you may also have other symptoms or problems. ... chap 28. Read More Acoustic neuroma Brain abscess Brain aneurysm repair Brain surgery Brain tumor - children Brain tumor - ...

  15. Stress Wave Interaction Between Two Adjacent Blast Holes

    NASA Astrophysics Data System (ADS)

    Yi, Changping; Johansson, Daniel; Nyberg, Ulf; Beyglou, Ali

    2016-05-01

    Rock fragmentation by blasting is determined by the level and state of stress in the rock mass subjected to blasting. With the application of electronic detonators, some researchers stated that it is possible to achieve improved fragmentation through stress wave superposition with very short delay times. This hypothesis was studied through theoretical analysis in the paper. First, the stress in rock mass induced by a single-hole shot was analyzed with the assumptions of infinite velocity of detonation and infinite charge length. Based on the stress analysis of a single-hole shot, the stress history and tensile stress distribution between two adjacent holes were presented for cases of simultaneous initiation and 1 ms delayed initiation via stress superposition. The results indicated that the stress wave interaction is local around the collision point. Then, the tensile stress distribution at the extended line of two adjacent blast holes was analyzed for a case of 2 ms delay. The analytical results showed that the tensile stress on the extended line increases due to the stress wave superposition under the assumption that the influence of neighboring blast hole on the stress wave propagation can be neglected. However, the numerical results indicated that this assumption is unreasonable and yields contrary results. The feasibility of improving fragmentation via stress wave interaction with precise initiation was also discussed. The analysis in this paper does not support that the interaction of stress waves improves the fragmentation.

  16. Coexistence Analysis of Adjacent Long Term Evolution (LTE) Systems

    SciTech Connect

    Aulama, Mohannad M.; Olama, Mohammed M

    2013-01-01

    As the licensing and deployment of Long term evolution (LTE) systems are ramping up, the study of coexistence of LTE systems is an essential topic in civil and military applications. In this paper, we present a coexistence study of adjacent LTE systems aiming at evaluating the effect of inter-system interference on system capacity and performance as a function of some of the most common mitigation techniques: frequency guard band, base station (BS) antenna coupling loss, and user equipment (UE) antenna spacing. A system model is constructed for two collocated macro LTE networks. The developed model takes into consideration the RF propagation environment, power control scheme, and adjacent channel interference. Coexistence studies are performed for a different combination of time/frequency division duplex (TDD/FDD) systems under three different guard-bands of 0MHz, 5MHz, and 10MHz. Numerical results are presented to advice the minimum frequency guard band, BS coupling loss, and UE antenna isolation required for a healthy system operation.

  17. Ion Channels in the Xylem Parenchyma of Barley Roots (A Procedure to Isolate Protoplasts from This Tissue and a Patch-Clamp Exploration of Salt Passageways into Xylem Vessels.

    PubMed Central

    Wegner, L. H.; Raschke, K.

    1994-01-01

    To identify mechanisms for the simultaneous release of anions and cations into the xylem sap in roots, we investigated voltage-dependent ion conductances in the plasmalemma of xylem parenchyma cells. We applied the patch-clamp technique to protoplasts isolated from the xylem parenchyma by differential enzymic digestion of steles of barley roots (Hordeum vulgare L. cv Apex). In the whole-cell configuration, three types of cation-selective rectifiers could be identified: (a) one activated at membrane potentials above about -50 mV; (b) a second type of outward current appeared at membrane potentials above +20 to +40 mV; (c) below a membrane potential of approximately -110 mV, an inward rectifier could be distinguished. In addition, an anion-specific conductance manifested itself in single-channel activity in a voltage range extending from about -100 to +30 mV, with remarkably slow gating. In excised patches, K+ channels activated at hyperpolarization as well as at depolarization. We suggest that salt is released from the xylem parenchyma into the xylem apoplast by simultaneous flow of cations and anions through channels, following electrochemical gradients set up by the ion uptake processes in the cortex and, possibly, the release and reabsorption of ions on their way to the xylem. PMID:12232243

  18. Convection Enhanced Delivery of Recombinant Adeno-associated Virus into the Mouse Brain.

    PubMed

    Nash, Kevin R; Gordon, Marcia N

    2016-01-01

    Recombinant adeno-associated virus (rAAV) has become an extremely useful tool for the study of gene over expression or knockdown in the central nervous system of experimental animals. One disadvantage of intracranial injections of rAAV vectors into the brain parenchyma has been restricted distribution to relatively small volumes of the brain. Convection enhanced delivery (CED) is a method for delivery of clinically relevant amounts of therapeutic agents to large areas of the brain in a direct intracranial injection procedure. CED uses bulk flow to increase the hydrostatic pressure and thus improve volume distribution. The CED method has shown robust gene transfer and increased distribution within the CNS and can be successfully used for different serotypes of rAAV for increased transduction of the mouse CNS. This chapter details the surgical injection of rAAV by CED into a mouse brain.

  19. 49 CFR 214.107 - Working over or adjacent to water.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... conditions, including weather, water speed, and terrain, merit additional protection, the skiff or boat shall... 49 Transportation 4 2012-10-01 2012-10-01 false Working over or adjacent to water. 214.107 Section... Working over or adjacent to water. (a) Bridge workers working over or adjacent to water with a depth...

  20. 49 CFR 214.107 - Working over or adjacent to water.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... conditions, including weather, water speed, and terrain, merit additional protection, the skiff or boat shall... 49 Transportation 4 2010-10-01 2010-10-01 false Working over or adjacent to water. 214.107 Section... Working over or adjacent to water. (a) Bridge workers working over or adjacent to water with a depth...

  1. 49 CFR 214.107 - Working over or adjacent to water.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... conditions, including weather, water speed, and terrain, merit additional protection, the skiff or boat shall... 49 Transportation 4 2011-10-01 2011-10-01 false Working over or adjacent to water. 214.107 Section... Working over or adjacent to water. (a) Bridge workers working over or adjacent to water with a depth...

  2. 49 CFR 214.107 - Working over or adjacent to water.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... conditions, including weather, water speed, and terrain, merit additional protection, the skiff or boat shall... 49 Transportation 4 2013-10-01 2013-10-01 false Working over or adjacent to water. 214.107 Section... Working over or adjacent to water. (a) Bridge workers working over or adjacent to water with a depth...

  3. 49 CFR 214.107 - Working over or adjacent to water.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... conditions, including weather, water speed, and terrain, merit additional protection, the skiff or boat shall... 49 Transportation 4 2014-10-01 2014-10-01 false Working over or adjacent to water. 214.107 Section... Working over or adjacent to water. (a) Bridge workers working over or adjacent to water with a depth...

  4. 27 CFR 19.162 - Operations bond for distilled spirits plant and adjacent bonded wine cellar.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... distilled spirits plant and adjacent bonded wine cellar. 19.162 Section 19.162 Alcohol, Tobacco Products and... bond for distilled spirits plant and adjacent bonded wine cellar. (a) One bond satisfying two requirements. A proprietor who operates a bonded wine cellar that is adjacent to the proprietor's...

  5. 27 CFR 19.162 - Operations bond for distilled spirits plant and adjacent bonded wine cellar.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... distilled spirits plant and adjacent bonded wine cellar. 19.162 Section 19.162 Alcohol, Tobacco Products and... bond for distilled spirits plant and adjacent bonded wine cellar. (a) One bond satisfying two requirements. A proprietor who operates a bonded wine cellar that is adjacent to the proprietor's...

  6. 27 CFR 19.162 - Operations bond for distilled spirits plant and adjacent bonded wine cellar.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... distilled spirits plant and adjacent bonded wine cellar. 19.162 Section 19.162 Alcohol, Tobacco Products and... bond for distilled spirits plant and adjacent bonded wine cellar. (a) One bond satisfying two requirements. A proprietor who operates a bonded wine cellar that is adjacent to the proprietor's...

  7. 27 CFR 19.162 - Operations bond for distilled spirits plant and adjacent bonded wine cellar.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... distilled spirits plant and adjacent bonded wine cellar. 19.162 Section 19.162 Alcohol, Tobacco Products and... bond for distilled spirits plant and adjacent bonded wine cellar. (a) One bond satisfying two requirements. A proprietor who operates a bonded wine cellar that is adjacent to the proprietor's...

  8. Visualization and Quantitative Assessment of the Brain Distribution of Insulin through Nose-to-Brain Delivery Based on the Cell-Penetrating Peptide Noncovalent Strategy.

    PubMed

    Kamei, Noriyasu; Shingaki, Tomotaka; Kanayama, Yousuke; Tanaka, Misa; Zochi, Riyo; Hasegawa, Koki; Watanabe, Yasuyoshi; Takeda-Morishita, Mariko

    2016-03-07

    Our recent work suggested that intranasal coadministration with the cell-penetrating peptide (CPP) penetratin increased the brain distribution of the peptide drug insulin. The present study aimed to distinctly certify the ability of penetratin to facilitate the nose-to-brain delivery of insulin by quantitatively evaluating the distribution characteristics in brain using radioactive (64)Cu-NODAGA-insulin. Autoradiography and analysis using a gamma counter of brain areas demonstrated that the accumulation of radioactivity was greatest in the olfactory bulb, the anterior part of the brain closest to the administration site, at 15 min after intranasal administration of (64)Cu-NODAGA-insulin with l- or d-penetratin. The brain accumulation of (64)Cu-NODAGA-insulin with penetratin was confirmed by ELISA using unlabeled insulin in which intact insulin was delivered to the brain after intranasal coadministration with l- or d-penetratin. By contrast, quantification of cerebrospinal fluid (CSF) samples showed increased insulin concentration in only the anterior portion of the CSF at 15 min after intranasal coadministration with l-penetratin. This study gives the first concrete proof that penetratin can accelerate the direct transport of insulin from the nasal cavity to the brain parenchyma. Further optimization of intranasal administration with CPP may increase the efficacy of delivery of biopharmaceuticals to the brain while reducing the risk of systemic drug exposure.

  9. Neuroinflammation and brain infections: historical context and current perspectives.

    PubMed

    Bentivoglio, Marina; Mariotti, Raffaella; Bertini, Giuseppe

    2011-01-07

    An overview of current concepts on neuroinflammation and on the dialogue between neurons and non-neuronal cells in three important infections of the central nervous systems (rabies, cerebral malaria, and human African trypanosomiasis or sleeping sickness) is here presented. Large numbers of cases affected by these diseases are currently reported. In the context of an issue dedicated to Camillo Golgi, historical notes on seminal discoveries on these diseases are also presented. Neuroinflammation is currently closely associated with pathogenetic mechanisms of chronic neurodegenerative diseases. Neuroinflammatory signaling in brain infections is instead relatively neglected in the neuroscience community, despite the fact that the above infections provide paradigmatic examples of alterations of the intercellular crosstalk between neurons and non-neuronal cells. In rabies, strategies of immune evasion of the host lead to silencing neuroinflammatory signaling. In the intravascular pathology which characterizes cerebral malaria, leukocytes and Plasmodium do not enter the brain parenchyma. In sleeping sickness, leukocytes and African trypanosomes invade the brain parenchyma at an advanced stage of infection. Both the latter pathologies leave open many questions on the targeting of neuronal functions and on the pathogenetic role of non-neuronal cells, and in particular astrocytes and microglia, in these diseases. All three infections are hallmarked by very severe clinical pictures and relative sparing of neuronal structure. Multidisciplinary approaches and a concerted action of the neuroscience community are needed to shed light on intercellular crosstalk in these dreadful brain diseases. Such effort could also lead to new knowledge on non-neuronal mechanisms which determine neuronal death or survival.

  10. 38. METAL WORKING TOOLS AND MACHINES ADJACENT TO THE CIRCA ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    38. METAL WORKING TOOLS AND MACHINES ADJACENT TO THE CIRCA 1900 MICHIGAN MACHINERY MFG. CO. PUNCH PRESS NEAR THE CENTER OF THE FACTORY BUILDING. AT THE LEFT FOREGROUND IS A MOVABLE TIRE BENDER FOR SHAPING ELI WINDMILL WHEEL RIMS. AT THE CENTER IS A FLOOR-MOUNTED CIRCA 1900 SNAG GRINDER OF THE TYPE USED FOR SMOOTHING ROUGH CASTINGS. ON THE WHEELED WORK STATION IS A SUNNEN BUSHING GRINDER, BEHIND WHICH IS A TRIPOD CHAIN VICE. IN THE CENTER BACKGROUND IS A WOODEN CHEST OF DRAWERS WHICH CONTAINS A 'RAG DRAWER' STILL FILLED WITH CLOTH RAGS PLACED IN THE FACTORY BUILDING AT THE INSISTENCE OF LOUISE (MRS. ARTHUR) KREGEL FOR THE CONVENIENCE AND CLEANLINESS OF WORKERS. IN THE LEFT BACKGROUND IS A CIRCA 1900 CROSS-CUTOFF CIRCULAR SAW. - Kregel Windmill Company Factory, 1416 Central Avenue, Nebraska City, Otoe County, NE

  11. Air bubble-shock wave interaction adjacent to gelantine surface

    NASA Astrophysics Data System (ADS)

    Lush, P. A.; Tomita, Y.; Onodera, O.; Takayama, K.; Sanada, N.; Kuwahara, M.; Ioritani, N.; Kitayama, O.

    1990-07-01

    The interaction between a shock wave and an air bubble-adjacent to a gelatine surface is investigated in order to simulate human tissue damage resulting from extracorporeal shock wave lithotripsy. Using high speed cine photography it is found that a shock wave of strength 11 MPa causes 1-3 mm diameter bubbles to produce high velocity microjets with penetration rates of approximately 110 m/s and penetration depths approximately equal to twice the initial bubble diameter. Theoretical considerations for liquid impact on soft solid of similar density indicate that microjet velocities will be twice the penetration rate, i.e. 220 m/s in the present case. Such events are the probable cause of observed renal tissue damage.

  12. Laser ablation of human atherosclerotic plaque without adjacent tissue injury

    NASA Technical Reports Server (NTRS)

    Grundfest, W. S.; Litvack, F.; Forrester, J. S.; Goldenberg, T.; Swan, H. J. C.

    1985-01-01

    Seventy samples of human cadaver atherosclerotic aorta were irradiated in vitro using a 308 nm xenon chloride excimer laser. Energy per pulse, pulse duration and frequency were varied. For comparison, 60 segments were also irradiated with an argon ion and an Nd:YAG laser operated in the continuous mode. Tissue was fixed in formalin, sectioned and examined microscopically. The Nd:YAG and argon ion-irradiated tissue exhibited a central crater with irregular edges and concentric zones of thermal and blast injury. In contrast, the excimer laser-irradiated tissue had narrow deep incisions with minimal or no thermal injury. These preliminary experiments indicate that the excimer laser vaporizes tissue in a manner different from that of the continuous wave Nd:YAG or argon ion laser. The sharp incision margins and minimal damage to adjacent normal tissue suggest that the excimer laser is more desirable for general surgical and intravascular uses than are the conventionally used medical lasers.

  13. Scolopendromorpha of New Guinea and adjacent islands (Myriapoda, Chilopoda).

    PubMed

    Schileyko, Arkady A; Stoev, Pavel E

    2016-08-04

    The centipede fauna of the second largest island in the world, New Guinea, and its adjacent islands, is poorly known, with most information deriving from the first half of the 20th century. Here we present new data on the order Scolopendromorpha based on material collected in the area in the last 40 years, mainly by Bulgarian and Latvian zoologists. The collections comprise eleven species of six genera and three families. The diagnosis of Cryptops (Trigonocryptops) is emended in the light of the recent findings. The old and doubtful record of Scolopendra multidens Newport, 1844 from New Guinea is referred to S. subspinipes Leach, 1815 and the species is here excluded from the present day list of New Guinean scolopendromorphs. Cryptops nepalensis Lewis, 1999 is here recorded from New Guinea for the first time. An annotated list and an identification key to the scolopendromorphs of the studied region are presented.

  14. GOAT ROCKS WILDERNESS AND ADJACENT ROADLESS AREAS, WASHINGTON.

    USGS Publications Warehouse

    Church, S.E.; Close, T.J.

    1984-01-01

    The Goat Rocks Wilderness and adjacent roadless areas are a rugged, highly forested, scenic area located on the crest of the Cascade Range in south-central Washington. Several mineral claims have been staked in the area. Mineral surveys were conducted. Geochemical, geophysical, and geologic investigations indicate that three areas have probable mineral-resource potential for base metals in porphyry-type deposits. Available data are not adequate to permit definition of the potential for oil and gas. There is little likelihood for the occurrence of other kinds of energy resources in the area. Evaluation of resource potential in the three areas identified as having probable mineral-resource potential could be improved by more detailed geochemical studies and geologic mapping.

  15. Reconnaissance geologic map of Kodiak Island and adjacent islands, Alaska

    USGS Publications Warehouse

    Wilson, Frederic H.

    2013-01-01

    Kodiak Island and its adjacent islands, located on the west side of the Gulf of Alaska, contain one of the largest areas of exposure of the flysch and melange of the Chugach terrane of southern Alaska. However, in the past 25 years, only detailed mapping covering small areas in the archipelago has been done. This map and its associated digital files (Wilson and others, 2005) present the best available mapping compiled in an integrated fashion. The map and associated digital files represent part of a systematic effort to release geologic map data for the United States in a uniform manner. The geologic data have been compiled from a wide variety of sources, ranging from state and regional geologic maps to large-scale field mapping. The map data are presented for use at a nominal scale of 1:500,000, although individual datasets (see Wilson and others, 2005) may contain data suitable for use at larger scales.

  16. Fungal Infection in the Brain: What We Learned from Intravital Imaging

    PubMed Central

    Shi, Meiqing; Mody, Christopher H.

    2016-01-01

    Approximately 1.2 billion people suffer from fungal diseases worldwide. Arguably, the most serious manifestation occurs when pathogenic fungi infect the brain, often causing fatal meningoencephalitis. For most fungi, infection occurs via the vascular route. The organism must first be arrested in the brain microvasculature and transmigrate into the brain parenchyma across the blood–brain barrier. As a result, host immune cells are recruited into the brain to contain the fungi. However, it remains poorly understood how fungi traffic to, and migrate into the brain and how immune cells interact with invading fungi in the brain. A new era of intravital fluorescence microscopy has begun to provide insights. We are able to employ this powerful approach to study dynamic interactions of disseminating fungi with brain endothelial cells as well as resident and recruited immune cells during the brain infection. In this review, with a focus on Cryptococcus neoformans, we will provide an overview of the application of intravital imaging in fungal infections in the brain, discuss recent findings and speculate on possible future research directions. PMID:27532000

  17. Shear-Induced Amyloid Formation in the Brain: I. Potential Vascular and Parenchymal Processes

    PubMed Central

    Trumbore, Conrad N.

    2016-01-01

    Shear distortion of amyloid-beta (Aβ) solutions accelerates amyloid cascade reactions that may yield different toxic oligomers than those formed in quiescent solutions. Recent experiments indicate that cerebrospinal fluid (CSF) and interstitial fluid (ISF) containing Aβ flow through narrow brain perivascular pathways and brain parenchyma. This paper suggests that such flow causes shear distortion of Aβ molecules involving conformation changes that may be one of the initiating events in the etiology of Alzheimer’s disease. Aβ shearing can occur in or around brain arteries and arterioles and is suggested as the origin of cerebral amyloid angiopathy deposits in cerebrovascular walls. Comparatively low flow rates of ISF within the narrow extracellular spaces (ECS) of the brain parenchyma are suggested as a possible initiating factor in both the formation of neurotoxic Aβ42 oligomers and amyloid fibrils. Aβ42 in slow-flowing ISF can gain significant shear energy at or near the walls of tortuous brain ECS flow paths, promoting the formation of a shear-distorted, excited state hydrophobic Aβ42* conformation. This Aβ42* molecule could possibly be involved in one of two paths, one involving rapid adsorption to a brain membrane surface, ultimately forming neurotoxic oligomers on membranes, and the other ultimately forming plaque within the ECS flow pathways. Rising Aβ concentrations combined with shear at or near critical brain membranes are proposed as contributing factors to Alzheimer’s disease neurotoxicity. These hypotheses may be applicable in other neurodegenerative diseases, including tauopathies and alpha-synucleinopathies, in which shear-distorted proteins also may form in the brain ECS. PMID:27567812

  18. Shear-Induced Amyloid Formation in the Brain: I. Potential Vascular and Parenchymal Processes.

    PubMed

    Trumbore, Conrad N

    2016-09-06

    Shear distortion of amyloid-beta (Aβ) solutions accelerates amyloid cascade reactions that may yield different toxic oligomers than those formed in quiescent solutions. Recent experiments indicate that cerebrospinal fluid (CSF) and interstitial fluid (ISF) containing Aβ flow through narrow brain perivascular pathways and brain parenchyma. This paper suggests that such flow causes shear distortion of Aβ molecules involving conformation changes that may be one of the initiating events in the etiology of Alzheimer's disease. Aβ shearing can occur in or around brain arteries and arterioles and is suggested as the origin of cerebral amyloid angiopathy deposits in cerebrovascular walls. Comparatively low flow rates of ISF within the narrow extracellular spaces (ECS) of the brain parenchyma are suggested as a possible initiating factor in both the formation of neurotoxic Aβ42 oligomers and amyloid fibrils. Aβ42 in slow-flowing ISF can gain significant shear energy at or near the walls of tortuous brain ECS flow paths, promoting the formation of a shear-distorted, excited state hydrophobic Aβ42* conformation. This Aβ42* molecule could possibly be involved in one of two paths, one involving rapid adsorption to a brain membrane surface, ultimately forming neurotoxic oligomers on membranes, and the other ultimately forming plaque within the ECS flow pathways. Rising Aβ concentrations combined with shear at or near critical brain membranes are proposed as contributing factors to Alzheimer's disease neurotoxicity. These hypotheses may be applicable in other neurodegenerative diseases, including tauopathies and alpha-synucleinopathies, in which shear-distorted proteins also may form in the brain ECS.

  19. Brain investigation and brain conceptualization

    PubMed Central

    Redolfi, Alberto; Bosco, Paolo; Manset, David; Frisoni, Giovanni B.

    Summary The brain of a patient with Alzheimer’s disease (AD) undergoes changes starting many years before the development of the first clinical symptoms. The recent availability of large prospective datasets makes it possible to create sophisticated brain models of healthy subjects and patients with AD, showing pathophysiological changes occurring over time. However, these models are still inadequate; representations are mainly single-scale and they do not account for the complexity and interdependence of brain changes. Brain changes in AD patients occur at different levels and for different reasons: at the molecular level, changes are due to amyloid deposition; at cellular level, to loss of neuron synapses, and at tissue level, to connectivity disruption. All cause extensive atrophy of the whole brain organ. Initiatives aiming to model the whole human brain have been launched in Europe and the US with the goal of reducing the burden of brain diseases. In this work, we describe a new approach to earlier diagnosis based on a multimodal and multiscale brain concept, built upon existing and well-characterized single modalities. PMID:24139654

  20. Neural Correlates of Speech Segregation Based on Formant Frequencies of Adjacent Vowels

    PubMed Central

    Alain, Claude; Arsenault, Jessica S.; Garami, Linda; Bidelman, Gavin M.; Snyder, Joel S.

    2017-01-01

    The neural substrates by which speech sounds are perceptually segregated into distinct streams are poorly understood. Here, we recorded high-density scalp event-related potentials (ERPs) while participants were presented with a cyclic pattern of three vowel sounds (/ee/-/ae/-/ee/). Each trial consisted of an adaptation sequence, which could have either a small, intermediate, or large difference in first formant (Δf1) as well as a test sequence, in which Δf1 was always intermediate. For the adaptation sequence, participants tended to hear two streams (“streaming”) when Δf1 was intermediate or large compared to when it was small. For the test sequence, in which Δf1 was always intermediate, the pattern was usually reversed, with participants hearing a single stream with increasing Δf1 in the adaptation sequences. During the adaptation sequence, Δf1-related brain activity was found between 100–250 ms after the /ae/ vowel over fronto-central and left temporal areas, consistent with generation in auditory cortex. For the test sequence, prior stimulus modulated ERP amplitude between 20–150 ms over left fronto-central scalp region. Our results demonstrate that the proximity of formants between adjacent vowels is an important factor in the perceptual organization of speech, and reveal a widely distributed neural network supporting perceptual grouping of speech sounds. PMID:28102300

  1. [Brain concussion].

    PubMed

    Pälvimäki, Esa-Pekka; Siironen, Jari; Pohjola, Juha; Hernesniemi, Juha

    2011-01-01

    Brain concussion is a common disturbance caused by external forces or acceleration affecting the head. It may be accompanied by transient loss of consciousness and amnesia. Typical symptoms include headache, nausea and dizziness; these may remain for a week or two. Some patients may experience transient loss of inability to create new memories or other brief impairment of mental functioning. Treatment is symptomatic. Some patients may suffer from prolonged symptoms, the connection of which with brain concession is difficult to show. Almost invariably the prognosis of brain concussion is good.

  2. Cell proliferation and death in the brain of active and hibernating frogs

    PubMed Central

    Cerri, Silvia; Bottiroli, Giovanni; Bottone, Maria Grazia; Barni, Sergio; Bernocchi, Graziella

    2009-01-01

    ‘Binomial’ cell proliferation and cell death have been studied in only a few non-mammalian vertebrates, such as fish. We thought it of interest to map cell proliferation/apoptosis in the brain of the frog (Rana esculenta L.) as this animal species undergoes, during the annual cycle, physiological events that could be associated with central nervous system damage. Therefore, we compared the active period and the deep underground hibernation of the frog. Using western blot analysis for proliferating cell nuclear antigen (PCNA), we revealed a positive 36 kDa band in all samples and found higher optical density values in the hibernating frogs than in active frogs. In both active and hibernating frogs, we found regional differences in PCNA-immunoreactive cells and terminal transferase dUTP nick-end labelling apoptotic cells in the ventricular zones and parenchyma areas of the main encephalon subdivisions. During the active period of the frogs, the highest concentration of PCNA-immunoreactive cells was found in the ventricle dorsal zone of the cerebral hemispheres but only some of the cells were apoptotic. By contrast, the tectal and cerebellar ventricular zones had a small or medium amount of PCNA-immunoreactive cells, respectively, and a higher number of apoptotic cells. During hibernation, an increased PCNA-immunoreactive cell number was observed in both the brain ventricles and parenchyma compared with active frogs. This increase was primarily evident in the lateral ventricles, a region known to be a proliferation ‘hot spot’. Although differences existed among the brain areas, a general increase of apoptotic cell death was found in hibernating frogs, with the highest number of apoptotic cells being detected in the parenchyma of the cerebral hemispheres and optic tectum. In particular, the increased number of apoptotic cells in the hibernating frogs compared with active frogs in the parenchyma of these brain areas occurred when cell proliferation was higher in

  3. Targeted polymeric magnetic nanoparticles for brain imaging

    NASA Astrophysics Data System (ADS)

    Kirthivasan, Bharat; Singh, Dhirender; Raut, Sangram; Bommana, Murali Mohan; Squillante, Emilio, III; Sadoqi, Mostafa

    2012-03-01

    The purpose of this study was to develop targeted polymeric magnetic nanoparticle system for brain imaging. Near infrared dye indocyanine green (ICG) or p-gycoprotein substrate rhodamine 123 (Rh123) were encapsulated along with oleic acid coated magnetic nanoparticles (OAMNP) in a matrix of poly(lactide-co-glycolide) (PLGA) and methoxy poly(ethyleneglycol)-poly(lactide) (Met-PEG-PLA). The nanoparticles were evaluated for morphology, particle size, dye content and magnetite content. The in vivo biodistribution study was carried out using three groups of six male Sprague Dawley rats each. Group I received a saline solution containing the dye, group II received dye-loaded polymeric magnetic nanoparticles without the aid of a magnetic field, and group III received dye-loaded polymeric magnetic nanoparticles with a magnet (8000 G) placed on the head of the rat. After a preset exposure period, the animals were sacrificed and dye concentration was measured in the brain, liver, kidney, lungs and spleen homogenates. Brain sections were fixed, cryotomed and visualized using fluorescence microscopy. The particles were observed to be spherical and had a mean size of 220 nm. The encapsulation efficiency for OAMNP was 57%, while that for ICG was 56% and for Rh123 was 45%. In the biodistribution study, while the majority of the dose for all animals was found in the liver, kidneys and spleen, group III showed a significantly higher brain concentration than the other two groups (p < 0.001). This result was corroborated by the fluorescence microscopy studies, which showed enhanced dye penetration into the brain tissue for group III. Further studies need to be done to elucidate the exact mechanism responsible for the increased brain uptake of dye to help us understand if the magnetic nanoparticles actually penetrate the blood brain barrier or merely deliver a massive load of dye just outside it, thereby triggering passive diffusion into the brain parenchyma. These results reinforce

  4. Real-time imaging of trapping and urease-dependent transmigration of Cryptococcus neoformans in mouse brain

    PubMed Central

    Shi, Meiqing; Li, Shu Shun; Zheng, Chunfu; Jones, Gareth J.; Kim, Kwang Sik; Zhou, Hong; Kubes, Paul; Mody, Christopher H.

    2010-01-01

    Infectious meningitis and encephalitis is caused by invasion of circulating pathogens into the brain. It is unknown how the circulating pathogens dynamically interact with brain endothelium under shear stress, leading to invasion into the brain. Here, using intravital microscopy, we have shown that Cryptococcus neoformans, a yeast pathogen that causes meningoencephalitis, stops suddenly in mouse brain capillaries of a similar or smaller diameter than the organism, in the same manner and with the same kinetics as polystyrene microspheres, without rolling and tethering to the endothelial surface. Trapping of the yeast pathogen in the mouse brain was not affected by viability or known virulence factors. After stopping in the brain, C. neoformans was seen to cross the capillary wall in real time. In contrast to trapping, viability, but not replication, was essential for the organism to cross the brain microvasculature. Using a knockout strain of C. neoformans, we demonstrated that transmigration into the mouse brain is urease dependent. To determine whether this could be amenable to therapy, we used the urease inhibitor flurofamide. Flurofamide ameliorated infection of the mouse brain by reducing transmigration into the brain. Together, these results suggest that C. neoformans is mechanically trapped in the brain capillary, which may not be amenable to pharmacotherapy, but actively transmigrates to the brain parenchyma with contributions from urease, suggesting that a therapeutic strategy aimed at inhibiting this enzyme could help prevent meningitis and encephalitis caused by C. neoformans infection. PMID:20424328

  5. Extracellular vesicles of the blood-brain barrier: Role in the HIV-1 associated amyloid beta pathology.

    PubMed

    András, Ibolya E; Leda, Ana; Contreras, Marta Garcia; Bertrand, Luc; Park, Minseon; Skowronska, Marta; Toborek, Michal

    2017-03-01

    HIV-infected brains are characterized by increased amyloid beta (Aβ) deposition. It is believed that the blood-brain barrier (BBB) is critical for Aβ homeostasis and contributes to Aβ accumulation in the brain. Extracellular vesicles (ECV), like exosomes, recently gained a lot of attention as potentially playing a significant role in Aβ pathology. In addition, HIV-1 hijacks the exosomal pathway for budding and release. Therefore, we investigated the involvement of BBB-derived ECV in the HIV-1-induced Aβ pathology in the brain. Our results indicate that HIV-1 increases ECV release from brain endothelial cells as well as elevates their Aβ cargo when compared to controls. Interestingly, brain endothelial cell-derived ECV transferred Aβ to astrocytes and pericytes. Infusion of brain endothelial ECV carrying fluorescent Aβ into the internal carotid artery of mice resulted in Aβ fluorescence associated with brain microvessels and in the brain parenchyma. These results suggest that ECV carrying Aβ can be successfully transferred across the BBB into the brain. Based on these observations, we conclude that HIV-1 facilitates the shedding of brain endothelial ECV carrying Aβ; a process that may increase Aβ exposure of cells of neurovascular unit, and contribute to amyloid deposition in HIV-infected brain.

  6. Brain radiation - discharge

    MedlinePlus

    Radiation - brain - discharge; Cancer-brain radiation; Lymphoma - brain radiation; Leukemia - brain radiation ... Decadron) while you are getting radiation to the brain. It may make you hungrier, cause leg swelling ...

  7. Brain Stimulation Therapies

    MedlinePlus

    ... Magnetic Seizure Therapy Deep Brain Stimulation Additional Resources Brain Stimulation Therapies Overview Brain stimulation therapies can play ... for a shorter recovery time than ECT Deep Brain Stimulation Deep brain stimulation (DBS) was first developed ...

  8. Brain tumor - primary - adults

    MedlinePlus

    ... Vestibular schwannoma (acoustic neuroma) - adults; Meningioma - adults; Cancer - brain tumor (adults) ... Primary brain tumors include any tumor that starts in the brain. Primary brain tumors can start from brain cells, ...

  9. Right Hemisphere Brain Damage

    MedlinePlus

    ... Language and Swallowing / Disorders and Diseases Right Hemisphere Brain Damage [ en Español ] What is right hemisphere brain ... right hemisphere brain damage ? What is right hemisphere brain damage? Right hemisphere brain damage (RHD) is damage ...

  10. Anatomy of the Brain

    MedlinePlus

    ... Young Adult Guidelines For brain tumor information and support Call: 800-886-ABTA (2282) or Complete our contact form Brain Tumor Information Brain Anatomy Brain Structure Neuron Anatomy Brain Tumor Symptoms Diagnosis Types of ...

  11. Transport of cargo from periphery to brain by circulating monocytes.

    PubMed

    Cintron, Amarallys F; Dalal, Nirjari V; Dooyema, Jeromy; Betarbet, Ranjita; Walker, Lary C

    2015-10-05

    The misfolding and aggregation of the Aβ peptide - a fundamental event in the pathogenesis of Alzheimer׳s disease - can be instigated in the brains of experimental animals by the intracranial infusion of brain extracts that are rich in aggregated Aβ. Recent experiments have found that the peripheral (intraperitoneal) injection of Aβ seeds induces Aβ deposition in the brains of APP-transgenic mice, largely in the form of cerebral amyloid angiopathy. Macrophage-type cells normally are involved in pathogen neutralization and antigen presentation, but under some circumstances, circulating monocytes have been found to act as vectors for the transport of pathogenic agents such as viruses and prions. The present study assessed the ability of peripheral monocytes to transport Aβ aggregates from the peritoneal cavity to the brain. Our initial experiments showed that intravenously delivered macrophages that had previously ingested fluorescent nanobeads as tracers migrate primarily to peripheral organs such as spleen and liver, but that a small number also reach the brain parenchyma. We next injected CD45.1-expressing monocytes from donor mice intravenously into CD45.2-expressing host mice; after 24h, analysis by fluorescence-activated cell sorting (FACS) and histology confirmed that some CD45.1 monocytes enter the brain, particularly in the superficial cortex and around blood vessels. When the donor monocytes are first exposed to Aβ-rich brain extracts from human AD cases, a subset of intravenously delivered Aβ-containing cells migrate to the brain. These experiments indicate that, in mouse models, circulating monocytes are potential vectors by which exogenously delivered, aggregated Aβ travels from periphery to brain, and more generally support the hypothesis that macrophage-type cells can participate in the dissemination of proteopathic seeds.

  12. Fragile Brains.

    ERIC Educational Resources Information Center

    Jensen, Eric

    2001-01-01

    Describes three types of brain disorders: the sluggish, the oppositional, and the depressed. Explains how to identify these disorders and offers educators strategies for dealing with each. (Contains 11 references.) (PKP)

  13. Brain abscess

    MedlinePlus

    ... small abscess (less than 2 cm) An abscess deep in the brain An abscess and meningitis Several ... or MRI scan may be needed for a deep abscess. During this procedure, medicines may be injected ...

  14. Brain Basics

    MedlinePlus Videos and Cool Tools

    ... genes and epigenetics may one day lead to genetic testing for people at risk for mental disorders. ... brain. DNA —The "recipe of life," containing inherited genetic information that helps to define physical and some ...

  15. Brain Autopsy

    MedlinePlus

    ... Monthly Donation Named Funds Planned Giving Gifts of Stock Business Partnerships Host an Event AFTD-Team Races ... family members to reach a closure after a long struggle. Brain autopsy is often done in conjunction ...

  16. Systemic hyperosmolality improves beta-glucuronidase distribution and pathology in murine MPS VII brain following intraventricular gene transfer.

    PubMed

    Ghodsi, A; Stein, C; Derksen, T; Martins, I; Anderson, R D; Davidson, B L

    1999-11-01

    Mucopolysaccharidosis VII, a classical lysosomal storage disease, is caused by deficiency of the enzyme beta-glucuronidase. Central nervous system (CNS) manifestations are severe with accumulations of storage vacuoles in all cell types. Intraventricular gene transfer can lead to transduction of the ependyma, with production and secretion of beta-glucuronidase into the cerebral spinal fluid and underlying cortex resulting in reversal of disease pathology restricted to the periventricular areas. We tested if systemic hyperosmolality would increase the distribution of beta-glucuronidase in brain parenchyma after intraventricular virus injection. Mice were administered mannitol, intraperitoneally, 20 days after gene transfer and 1 day prior to sacrifice. Mannitol-induced systemic hyperosmolality caused a marked penetration of beta-glucuronidase into the brain parenchyma. If mannitol was administered at the time of the intraventricular injection of virus, there was penetration of vector across the ependymal cell layer, with infection of cells in the subependymal region. This also resulted in increased beta-glucuronidase activity throughout the brain. Sections of brains from beta-glucuronidase-deficient mice showed correction of cellular pathology in the subependymal region plus cortical structures away from the ventricular wall. These data indicate that virus-mediated gene transfer to the brain via the ventricles, coupled with systemic mannitol administration, can lead to extensive CNS distribution of beta-glucuronidase with concomitant correction of the storage defect. Our findings have positive therapeutic implications for the treatment of CNS disorders with gene transfer vectors and recombinant proteins.

  17. Infra-red thermometry: the reliability of tympanic and temporal artery readings for predicting brain temperature after severe traumatic brain injury

    PubMed Central

    Kirk, Danielle; Rainey, Timothy; Vail, Andy; Childs, Charmaine

    2009-01-01

    Introduction Temperature measurement is important during routine neurocritical care especially as differences between brain and systemic temperatures have been observed. The purpose of the study was to determine if infra-red temporal artery thermometry provides a better estimate of brain temperature than tympanic membrane temperature for patients with severe traumatic brain injury. Methods Brain parenchyma, tympanic membrane and temporal artery temperatures were recorded every 15–30 min for five hours during the first seven days after admission. Results Twenty patients aged 17–76 years were recruited. Brain and tympanic membrane temperature differences ranged from -0.8 °C to 2.5 °C (mean 0.9 °C). Brain and temporal artery temperature differences ranged from -0.7 °C to 1.5 °C (mean 0.3 °C). Tympanic membrane temperature differed from brain temperature by an average of 0.58 °C more than temporal artery temperature measurements (95% CI 0.31 °C to 0.85 °C, P < 0.0001). Conclusions At temperatures within the normal to febrile range, temporal artery temperature is closer to brain temperature than is tympanic membrane temperature. PMID:19473522

  18. Brain imaging and brain function

    SciTech Connect

    Sokoloff, L.

    1985-01-01

    This book is a survey of the applications of imaging studies of regional cerebral blood flow and metabolism to the investigation of neurological and psychiatric disorders. Contributors review imaging techniques and strategies for measuring regional cerebral blood flow and metabolism, for mapping functional neural systems, and for imaging normal brain functions. They then examine the applications of brain imaging techniques to the study of such neurological and psychiatric disorders as: cerebral ischemia; convulsive disorders; cerebral tumors; Huntington's disease; Alzheimer's disease; depression and other mood disorders. A state-of-the-art report on magnetic resonance imaging of the brain and central nervous system rounds out the book's coverage.

  19. Pulsatile cerebrospinal fluid dynamics in the human brain.

    PubMed

    Linninger, Andreas A; Tsakiris, Cristian; Zhu, David C; Xenos, Michalis; Roycewicz, Peter; Danziger, Zachary; Penn, Richard

    2005-04-01

    Disturbances of the cerebrospinal fluid (CSF) flow in the brain can lead to hydrocephalus, a condition affecting thousands of people annually in the US. Considerable controversy exists about fluid and pressure dynamics, and about how the brain responds to changes in flow patterns and compression in hydrocephalus. This paper presents a new model based on the first principles of fluid mechanics. This model of fluid-structure interactions predicts flows and pressures throughout the brain's ventricular pathways consistent with both animal intracranial pressure (ICP) measurements and human CINE phase-contrast magnetic resonance imaging data. The computations provide approximations of the tissue deformations of the brain parenchyma. The model also quantifies the pulsatile CSF motion including flow reversal in the aqueduct as well as the changes in ICPs due to brain tissue compression. It does not require the existence of large transmural pressure differences as the force for ventricular expansion. Finally, the new model gives an explanation of communicating hydrocephalus and the phenomenon of asymmetric hydrocephalus.

  20. Transcranial amelioration of inflammation and cell death after brain injury

    NASA Astrophysics Data System (ADS)

    Roth, Theodore L.; Nayak, Debasis; Atanasijevic, Tatjana; Koretsky, Alan P.; Latour, Lawrence L.; McGavern, Dorian B.

    2014-01-01

    Traumatic brain injury (TBI) is increasingly appreciated to be highly prevalent and deleterious to neurological function. At present, no effective treatment options are available, and little is known about the complex cellular response to TBI during its acute phase. To gain insights into TBI pathogenesis, we developed a novel murine closed-skull brain injury model that mirrors some pathological features associated with mild TBI in humans and used long-term intravital microscopy to study the dynamics of the injury response from its inception. Here we demonstrate that acute brain injury induces vascular damage, meningeal cell death, and the generation of reactive oxygen species (ROS) that ultimately breach the glial limitans and promote spread of the injury into the parenchyma. In response, the brain elicits a neuroprotective, purinergic-receptor-dependent inflammatory response characterized by meningeal neutrophil swarming and microglial reconstitution of the damaged glial limitans. We also show that the skull bone is permeable to small-molecular-weight compounds, and use this delivery route to modulate inflammation and therapeutically ameliorate brain injury through transcranial administration of the ROS scavenger, glutathione. Our results shed light on the acute cellular response to TBI and provide a means to locally deliver therapeutic compounds to the site of injury.

  1. Systemic Delivery of Blood-Brain Barrier Targeted Polymeric Nanoparticles Enhances Delivery to Brain Tissue

    PubMed Central

    Saucier-Sawyer, Jennifer K.; Deng, Yang; Seo, Young-Eun; Cheng, Christopher J.; Zhang, Junwei; Quijano, Elias; Saltzman, W. Mark

    2016-01-01

    Delivery of therapeutic agents to the central nervous system is a significant challenge, hindering progress in the treatment of diseases such as glioblastoma. Due to the presence of the blood-brain barrier (BBB), therapeutic agents do not readily transverse the brain endothelium to enter the parenchyma. Previous reports suggest that surface modification of polymer nanoparticles can improve their ability to cross the BBB, but it is unclear whether the observed enhancements in transport are large enough to enhance therapy. In this study, we synthesized two degradable polymer nanoparticle systems surface-modified with ligands previously suggested to improve BBB transport, and tested their ability to cross the BBB after intravenous injection in mice. All nanoparticle preparations were able to cross the BBB, although generally in low amounts (<0.5% of the injected dose), which was consistent with prior reports. One nanoparticle produced significantly higher brain uptake (~0.8% of the injected dose): a block copolymer of polylactic acid and hyperbranched polyglycerol, surface modified with adenosine (PLA-HPG-Ad). PLA-HPG-Ad nanoparticles provided controlled release of camptothecin, killing U87 glioma cells in culture. When administered intravenously in mice with intracranial U87 tumors, they failed to increase survival. These results suggest that enhancing nanoparticle transport across the BBB does not necessarily yield proportional pharmacological effects. PMID:26453169

  2. SRC family kinases as novel therapeutic targets to treat breast cancer brain metastases.

    PubMed

    Zhang, Siyuan; Huang, Wen-Chien; Zhang, Lin; Zhang, Chenyu; Lowery, Frank J; Ding, Zhaoxi; Guo, Hua; Wang, Hai; Huang, Suyun; Sahin, Aysegul A; Aldape, Kenneth D; Steeg, Patricia S; Yu, Dihua

    2013-09-15

    Despite better control of early-stage disease and improved overall survival of patients with breast cancer, the incidence of life-threatening brain metastases continues to increase in some of these patients. Unfortunately, other than palliative treatments there is no effective therapy for this condition. In this study, we reveal a critical role for Src activation in promoting brain metastasis in a preclinical model of breast cancer and we show how Src-targeting combinatorial regimens can treat HER2(+) brain metastases in this model. We found that Src was hyperactivated in brain-seeking breast cancer cells derived from human cell lines or from patients' brain metastases. Mechanistically, Src activation promoted tumor cell extravasation into the brain parenchyma via permeabilization of the blood-brain barrier. When combined with the EGFR/HER2 dual-targeting drug lapatinib, an Src-targeting combinatorial regimen prevented outgrowth of disseminated breast cancer cells through the induction of cell-cycle arrest. More importantly, this combinatorial regimen inhibited the outgrowth of established experimental brain metastases, prolonging the survival of metastases-bearing mice. Our results provide a rationale for clinical evaluation of Src-targeting regimens to treat patients with breast cancer suffering from brain metastasis.

  3. Hydrocarbon provinces and productive trends in Libya and adjacent areas

    SciTech Connect

    Missallati, A.A. Ltd., Tripoli )

    1988-08-01

    According to the age of major reservoirs, hydrocarbon occurrences in Libya and adjacent areas can be grouped into six major systems which, according to their geographic locations, can be classified into two major hydrocarbon provinces: (1) Sirte-Pelagian basins province, with major reservoirs ranging from middle-late Mesozoic to early Tertiary, and (2) Murzog-Ghadames basins province, with major reservoirs ranging from early Paleozoic to early Mesozoic. In the Sirte-Pelagian basins province, hydrocarbons have been trapped in structural highs or in stratigraphic wedge-out against structural highs and in carbonate buildups. Here, hydrocarbon generation is characterized by the combined effect of abundant structural relief and reservoir development in the same hydrocarbon systems of the same age, providing an excellent example of hydrocarbon traps in sedimentary basins that have undergone extensive tensional fracturing in a shallow marine environment. In the Murzog-Ghadames basins province, hydrocarbons have been trapped mainly in structural highs controlled by paleostructural trends as basement arches which acted as focal points for oil migration and accumulation.

  4. Tissue microenvironments within functional cortical subdivisions adjacent to focal stroke.

    PubMed

    Katsman, Diana; Zheng, Jian; Spinelli, Kateri; Carmichael, S Thomas

    2003-09-01

    Stroke produces a region of complete cell death and areas of partial damage, injury, and gliosis. The spatial relationship of these regions of damage to the infarct core and within spared neuronal circuits has not been identified. A model of cortical stroke was developed within functional subsets of the somatosensory cortex. Infarct size, regions of apoptosis, oxidative DNA damage, heat shock protein induction, and subtypes of reactive gliosis were precisely mapped with the somatosensory body map, quantified, and interrelated. Three tissue microenvironments were recognized: zones of partial ischemic damage, heat shock protein induction, and distributed gliosis. These three zones involved progressively more distant cortical regions, each larger than the infarct core. The zone of partial ischemic damage represents an overlap region of apoptotic cell death, oxidative DNA damage, loss of synaptic connections, and local reactive gliosis. The zone of distributed gliosis occupies distinct functional areas of the somatosensory cortex. The tissue reorganization induced by stroke is much larger than the stroke site itself. Adjacent tissue microenvironments are sites of distinct reactive cellular signaling and may serve as a link between the processes of acute cell death and delayed neuronal plasticity after focal stroke.

  5. Varied interactions between proviruses and adjacent host chromatin.

    PubMed Central

    Conklin, K F; Groudine, M

    1986-01-01

    Retroviruses integrated at unique locations in the host genome can be expressed at different levels. We have analyzed the preintegration sites of three transcriptionally competent avian endogenous proviruses (evs) to determine whether the various levels of provirus expression correlate with their location in active or inactive regions of chromatin. Our results show that in three of four cell types, the chromatin conformation (as defined by relative nuclease sensitivity) of virus preintegration sites correlates with the level of expression of the resident provirus in ev+ cells: two inactive proviruses (ev-1 and ev-2) reside in nuclease-resistant chromatin domains and one active provirus (ev-3) resides in a nuclease-sensitive domain. Nuclear runoff transcription assays reveal that the preintegration sites of the active and inactive viruses are not transcribed. However, in erythrocytes of 15-day-old chicken embryos (15d RBCs), the structure and activity of the ev-3 provirus is independent of the conformation of its preintegration site. In this cell type, the ev-3 preintegration site is organized in a nuclease-resistant conformation, while the ev-3 provirus is in a nuclease-sensitive conformation and is transcribed. In addition, the nuclease sensitivity of host sequences adjacent to ev-3 is altered in ev-3+ 15d RBCs relative to that found in 15d RBCs that lack ev-3. These data suggest that the relationship between preintegration site structure and retrovirus expression is more complex than previously described. Images PMID:3025623

  6. Light scattering by adjacent red blood cells: a mathematical model

    NASA Astrophysics Data System (ADS)

    Uzunoglou, Nikolaos K.; Stamatakos, Georgios; Koutsouris, Dimitrios; Yova-Loukas, Dido M.

    1995-01-01

    Simple approximate scattering theories such as the Rayleigh-Gans theory are not generally applicable to the case of light scattering by red blood cell (RBC) aggregates, including thrombus. This is mainly due to the extremely short distance separating erythrocytes in the aggregates (of the order of 25 nm) as well as to the substantial size of the aggregates. Therefore, in this paper a new mathematical model predicting the electromagnetic field produced by the scattering of a plane electromagnetic wave by a system of two adjacent RBCs is presented. Each RBC is modeled as a homogeneous dielectric ellipsoid of complex index of refraction surrounded by transparent plasma. The relative position and orientation of the ellipsoids are arbitrary. Scattering is formulated in terms of an integral equation which, however, contains two singular kernels. The singular equation is transformed into a pair of nonsingular integral equations for the Fourier transform of the internal field of each RBC. The latter equations are solved by reducing them by quadrature into a matrix equation. The resulting solutions are used to estimate the scattering amplitude. Convergence aspects concerning the numerical calculation of the matrix elements originating from the interaction between the RBCs are also presented.

  7. Stereotactic radiotherapy using Novalis for craniopharyngioma adjacent to optic pathways.

    PubMed

    Hashizume, Chisa; Mori, Yoshimasa; Kobayashi, Tatsuya; Shibamoto, Yuta; Nagai, Aiko; Hayashi, Naoki

    2010-06-01

    Craniopharyngioma has benign histological character. However, because of proximity to optic pathways, pituitary gland, and hypothalamus, it may cause severe and permanent damage to such critical structures and can even be life threatening. Total surgical resection is often difficult. This study aims to evaluate treatment results of Novalis stereotactic radiotherapy (SRT) for craniopharyngioma adjacent to optic pathways. Ten patients (six men, four women) with craniopharyngioma and median age of 56.5 years (range 10-74 years) were treated by SRT using Novalis from July 2006 through March 2009. Median volume of tumor was 7.9 ml (range 1.1-21 ml). Three-dimensional noncoplanar five- or seven-beam SRT or coplanar five-beam SRT with intensity modulation was performed. Total dose of 30-39 Gy in 10-15 fractions (median 33 Gy) was delivered to the target. Ten patients were followed up for 9-36 months (median 25.5 months). Response rate was 80% (8/10), and control rate was 100%. Improvement of neurological symptoms was observed in five patients. No serious complications due to SRT were found. SRT for craniopharyngioma may be a safe and effective treatment. Longer follow-up is necessary to determine long-term tumor control or late complications.

  8. Congenital stenosis and adjacent segment disease in the cervical spine.

    PubMed

    Eubanks, Jason David; Belding, Jon; Schnaser, Erik; Rowan, Andrew; Moffitt, Gable; Weaver, John; Reich, Michael S; Bechtel, Chris; Xie, Ke; Gande, Abhiram; Hohl, Justin; Braly, Brett; Hilibrand, Alan; Kang, James D

    2013-10-01

    Symptomatic adjacent segment disease (ASD) after anterior cervical fusion (ACF) is reported in 25% of patients at 10 years postoperatively. Debate continues as to whether this degeneration is due to the natural history of the disk or the changed biomechanics after ACF. This study explored whether congenital stenosis predisposes patients to an increased incidence of ASD after ACF. A retrospective review of 635 patients with myelopathy or radiculopathy was performed; 364 patients had complete records for review. Patients underwent 1- to 5-level ACF (94 one-level, 145 two-level, 79 three-level, 45 four-level, and 1 five-level). Radiographs were evaluated for bony congenital stenosis using validated parameters, and ASD was measured according to Hilibrand's criteria and correlated with symptomatic ASD. Congenital stenosis was found in 21.7% of patients and radiographic ASD in 33.5%, with a significant association between these parameters. However, symptomatic ASD occurred in 11.8% of patients; no association between congenital stenosis and symptomatic ASD or myelopathy and ASD was found. Clinical results demonstrated excellent or good Robinson scores in 86.2% of patients and Odom scores in 87% of patients. Despite mostly excellent to good outcomes, symptomatic ASD is common after ACF. Although congenital stenosis appears to increase the incidence of radiographic ASD, it does not appear to predict symptomatic ASD.

  9. The hydraulics of exchange flow between adjacent confined building zones

    NASA Astrophysics Data System (ADS)

    Nabi, Saleh; Flynn, Morris

    2012-11-01

    Buoyancy-driven flow between two finite zones containing fluid of slightly different density is investigated. The two zones are connected through a common opening that spans the channel width so that a two layer exchange flow develops once it is removed. In the zone that initially contained dense fluid, a buoyant plume of light fluid mixes with the dense fluid leading, over time, to the development of a nontrivial ambient density stratification. Meanwhile, dense fluid flows as a gravity current into the zone that initially contained light fluid. This gravity current reflects from the end wall and propagates back toward the opening in the form of an internal bore. When the bore reaches the opening, the dynamics of the exchange flow (and consequently the source conditions of the buoyant plume) are substantially altered. Such dynamics are modeled by combining elements of gravity current, internal bore, plume and exchange flow theory; model predictions, such as that the density jump across the first front steadily decreases once the exchange flow becomes transient, are corroborated by salt-bath laboratory experiments. Substantially different predictions arise when either or both of the adjacent zones are assumed to be well-mixed so that no vertical gradient of density is allowed.

  10. The Thermomagnetic Instability in Superconducting Films with Adjacent Metal Layer

    NASA Astrophysics Data System (ADS)

    Vestgården, J. I.; Galperin, Y. M.; Johansen, T. H.

    2013-12-01

    Dendritic flux avalanches is a frequently encountered consequence of the thermomagnetic instability in type-II superconducting films. The avalanches, which are potentially harmful for superconductor-based devices, can be suppressed by an adjacent normal metal layer, even when the two layers are not in thermal contact. The suppression of the avalanches in this case is due to so-called magnetic braking, caused by eddy currents generated in the metal layer by propagating magnetic flux. We develop a theory of magnetic braking by analyzing coupled electrodynamics and heat flow in a superconductor-normal metal bilayer. The equations are solved by linearization and by numerical simulation of the avalanche dynamics. We find that in an uncoated superconductor, even a uniform thermomagnetic instability can develop into a dendritic flux avalanche. The mechanism is that a small non-uniformity caused by the electromagnetic non-locality induces a flux-flow hot spot at a random position. The hot spot quickly develops into a finger, which at high speeds penetrates into the superconductor, forming a branching structure. Magnetic braking slows the avalanches, and if the normal metal conductivity is sufficiently high, it can suppress the formation of the dendritic structure. During avalanches, the braking by the normal metal layer prevents the temperature from exceeding the transition temperature of the superconductor. Analytical criteria for the instability threshold are developed using the linear stability analysis. The criteria are found to match quantitatively the instability onsets obtained in simulations.

  11. Snow Distribution Patterns in Clearings and Adjacent Forest

    NASA Astrophysics Data System (ADS)

    Golding, Douglas L.; Swanson, Robert H.

    1986-12-01

    Snow accumulation patterns were determined for clearings and adjacent forest at Marmot Creek experimental watershed and James River, Alberta. At maximum accumulation snow water equivalent (SWE) was greater in clearings than in forest whether clearings were large, as in 8- to 13-ha blocks where SWE averaged 20% more than in the forest, or small as in the ¼ to 6-H (height) diameter circular clearings where SWE was 13-45% greater than in the forest. SWE was 42 to 52% less in north than in south sectors of 2-6 H clearings. These differences increased with clearing size and time since beginning of accumulation period and are caused by snow ablation (melt and evaporation), a function of direct solar radiation reaching the snowpack. In such situations the snow that has accumulated on the ground cannot be considered a measure of the snow that has actually fallen there. For water balances and hydrologic modeling, snow measurements in partially cleared watersheds must be adjusted for temporal and spatial factors specific to the watershed.

  12. Nanoparticle-based evaluation of blood brain-barrier leakage during the foreign body response

    PubMed Central

    Sawyer, Andrew J.; Kyriakides, Themis R.

    2013-01-01

    Objective The brain foreign body response (FBR) is an important process that limits the functionality of electrodes that comprise the brain-machine interface. Associated events in this process include leakage of the blood brain barrier (BBB), reactive astrogliosis, recruitment and activation of microglia, and neuronal degeneration. Proper BBB function is also integral to maintaining neuronal health and function. Previous attempts to characterize BBB integrity have shown homogeneous leakage of macromolecules up to 10 nm in size. In the present study, we describe a new method of measuring BBB permeability during the foreign body response in a mouse model. Approach Fluorescent nanoparticles were delivered via the tail vein into implant-bearing mice. Tissue sections were then analyzed using fluorescence microscopy to observe nanoparticles in the tissue. Gold nanoparticles were also used in conjunction with TEM to confirm the presence of nanoparticles in the brain parenchyma. Main results By using polymer nanoparticle tracers, which are significantly larger than conventional macromolecular tracers, we show near-implant BBB gaps of up to 500 nm in size that persist for at least 4 weeks after implantation. Further characterization of the BBB illustrates that leakage during the brain FBR is heterogeneous with gaps between at least 10 and 500 nm. Moreover, electron microscopy was used to confirm that the nanoparticle tracers enter into the brain parenchyma near chronic brain implants. Significance Taken together, our findings demonstrate that the FBR-induced BBB leakage is characterized by larger gaps and is of longer duration than previously thought. This technique can be applied to examine the BBB in other disease states as well as during induced, transient, BBB opening. PMID:23337399

  13. Continuous infusion of proinflammatory cytokines into the brain to study brain cytokine induced local and systemic immune effects.

    PubMed

    Schöning, B; Elepfandt, P; Lanksch, W R; Volk, H D; Woiciechowsky, C

    1999-07-01

    Proinflammatory cytokines are produced in the brain after various kinds of insult (ischemia, trauma, infection). In this process interleukin (IL)-1beta, IL-6 and tumor necrosis factor (TNF)-alpha are most important. These cytokines are key mediators of inflammation. Furthermore, these cytokines can act as neurotransmitters and develop direct effects on the central nervous system (CNS) including fever, sleep and stimulation of the neuroendocrine as well as sympathetic nervous system. Moreover, IL-1beta and TNF-alpha may also be involved in brain repair and regenerating processes. However, most of the data about the role of cytokines in the brain have been obtained from either in vitro studies or bolus injections into the brain parenchyma or cerebroventricular system. On the other hand, it is known that cytokines are released continuously into the brain after a cerebral insult over a period of 24 to 48 h. In order to further complete the knowledge about the interactions between neural and immune cells to overcome the primary insult and initiate repair and regeneration in the CNS, a new animal model of local inflammation reaction was established using chronic intracerebral infusion of rat recombinant cytokines.

  14. Magnetic resonance Elastography of the Lung parenchyma in an in situ porcine model with a non-invasive mechanical driver: Correlation of Shear Stiffness with Trans-respiratory system Pressures

    PubMed Central

    Mariappan, Yogesh K; Kolipaka, Arunark; Manduca, Armando; Hubmayr, Rolf D; Ehman, Richard L; Araoz, Philip; McGee, Kiaran P

    2011-01-01

    Quantification of the mechanical properties of lung parenchyma is an active field of research due to the association of this metric with normal function, disease initiation and progression. A phase contrast MRI-based elasticity imaging technique known as magnetic resonance elastography (MRE) is being investigated as a method for measuring the shear stiffness of lung parenchyma. Previous experiments performed with small animals using invasive drivers in direct contact with the lungs have indicated that the quantification of lung shear modulus with 1H based MRE is feasible. This technique has been extended to an in situ porcine model with a noninvasive mechanical driver placed on the chest wall. This approach was tested to measure the change in parenchymal stiffness as a function of airway opening pressure (Pao) in 10 adult pigs. In all animals, shear stiffness was successfully quantified at four different Pao values. Mean (± std error of mean) pulmonary parenchyma density corrected stiffness values were calculated to be 1.48 (±0.09), 1.68 (±0.10), 2.05 (±0.13) and 2.23 (±0.17) kPa for Pao values of 5, 10, 15 and 20 cm H2O respectively. Shear stiffness increased with increasing Pao, in agreement with the literature. It is concluded that in an in situ porcine lung shear stiffness can be quantitated with 1H MRE using a noninvasive mechanical driver, and that it is feasible to measure the change in shear stiffness due to change in Pao. PMID:21590723

  15. Anti-IL-6 neutralizing antibody modulates blood-brain barrier function in the ovine fetus.

    PubMed

    Zhang, Jiyong; Sadowska, Grazyna B; Chen, Xiaodi; Park, Seon Yeong; Kim, Jeong-Eun; Bodge, Courtney A; Cummings, Erin; Lim, Yow-Pin; Makeyev, Oleksandr; Besio, Walter G; Gaitanis, John; Banks, William A; Stonestreet, Barbara S

    2015-05-01

    Impaired blood-brain barrier function represents an important component of hypoxic-ischemic brain injury in the perinatal period. Proinflammatory cytokines could contribute to ischemia-related blood-brain barrier dysfunction. IL-6 increases vascular endothelial cell monolayer permeability in vitro. However, contributions of IL-6 to blood-brain barrier abnormalities have not been examined in the immature brain in vivo. We generated pharmacologic quantities of ovine-specific neutralizing anti-IL-6 mAbs and systemically infused mAbs into fetal sheep at 126 days of gestation after exposure to brain ischemia. Anti-IL-6 mAbs were measured by ELISA in fetal plasma, cerebral cortex, and cerebrospinal fluid, blood-brain barrier permeability was quantified using the blood-to-brain transfer constant in brain regions, and IL-6, tight junction proteins, and plasmalemma vesicle protein (PLVAP) were detected by Western immunoblot. Anti-IL-6 mAb infusions resulted in increases in mAb (P < 0.05) in plasma, brain parenchyma, and cerebrospinal fluid and decreases in brain IL-6 protein. Twenty-four hours after ischemia, anti-IL-6 mAb infusions attenuated ischemia-related increases in blood-brain barrier permeability and modulated tight junction and PLVAP protein expression in fetal brain. We conclude that inhibiting the effects of IL-6 protein with systemic infusions of neutralizing antibodies attenuates ischemia-related increases in blood-brain barrier permeability by inhibiting IL-6 and modulates tight junction proteins after ischemia.

  16. Intracranial Intra-arachnoid Diverticula and Cyst-like Abnormalities of the Brain.

    PubMed

    Platt, Simon; Hicks, Jill; Matiasek, Lara

    2016-03-01

    Primary intracranial cystic or cyst-like lesions include intra-arachnoid, epidermoid, dermoid, and choroid plexus cysts. Differentiation of these cystic lesions can usually be accomplished by imaging studies alone; however, some cysts are similar in appearance and require histopathology for definitive diagnosis. Clinical signs often reflect the location of the cysts within the intracranial cavity rather than the type of cyst. If clinical signs are significant and progressive, surgical removal is warranted and may be successful, although cystic contents could be harmful if allowed to contact surrounding brain parenchyma or meninges.

  17. Delivery of local therapeutics to the brain: working toward advancing treatment for malignant gliomas.

    PubMed

    Chaichana, Kaisorn L; Pinheiro, Leon; Brem, Henry

    2015-03-01

    Malignant gliomas, including glioblastoma and anaplastic astrocytomas, are characterized by their propensity to invade surrounding brain parenchyma, making curative resection difficult. These tumors typically recur within two centimeters of the resection cavity even after gross total removal. As a result, there has been an emphasis on developing therapeutics aimed at achieving local disease control. In this review, we will summarize the current developments in the delivery of local therapeutics, namely direct injection, convection-enhanced delivery and implantation of drug-loaded polymers, as well as the application of these therapeutics in future methods including microchip drug delivery and local gene therapy.

  18. Brain death.

    PubMed

    Wijdicks, Eelco F M

    2013-01-01

    The diagnosis of brain death should be based on a simple premise. If every possible confounder has been excluded and all possible treatments have been tried or considered, irreversible loss of brain function is clinically recognized as the absence of brainstem reflexes, verified apnea, loss of vascular tone, invariant heart rate, and, eventually, cardiac standstill. This condition cannot be reversed - not even partly - by medical or surgical intervention, and thus is final. Many countries in the world have introduced laws that acknowledge that a patient can be declared brain-dead by neurologic standards. The U.S. law differs substantially from all other brain death legislation in the world because the U.S. law does not spell out details of the neurologic examination. Evidence-based practice guidelines serve as a standard. In this chapter, I discuss the history of development of the criteria, the current clinical examination, and some of the ethical and legal issues that have emerged. Generally, the concept of brain death has been accepted by all major religions. But patients' families may have different ideas and are mostly influenced by cultural attitudes, traditional customs, and personal beliefs. Suggestions are offered to support these families.

  19. Seismotectonics of Northeastern United States and adjacent Canada

    SciTech Connect

    Yang, J.; Aggarwal, Y.P.

    1981-06-10

    Data for local earthquakes recorded by a network of stations in northeastern United States and adjacent Canada were analyzed to study the seismicity, the relationship between earthquakes and known faults, the state of stress, and crustal and upper mantle velocity structure. In addition, portable seismographs were deployed in the field to study aftershocks. As a result, accurate locations for about 364 local earthquakes (2< or =m/sub b/< or =5) and 22 focal mechanism solutions were determined. A comparison of the spatial distribution of these events (1970--1979) with historical earthquakes (1534--1959) reveals that seismic activity in the northeast is relatively stationary in space: those areas that have had little or no seismicity historically are relatively aseismic today, whereas the historically active areas are also active today. The instrumental locations, historical seismicity, and focal mechanism solutions show an internal consistency that help us distinguish two distinct seismogenic provinces. (1) The Adirondack-western Quebec province is a northwesterly trending zone of seismic activity, about 200 km wide and at least 500 km long, extending from the SE Adirondacks into western Quebec, Canada. Thrust faulting on planes striking NNW to NW appears to predominate, and the inferred axis of maximum horizontal compression is largely uniform and trends WSW, nearly parallel to the calculated absolute plate motion of North America. Little or no seismicity is found where anorthosite outcrops at the surface. Correlations between gravity anomalies and earthquake locations suggest that seismic activity in this zone is localized to regions of steep NE or SW gradient in Bouguer anomalies. This zone does not appear to extend southeastward to Boston, as proposed by some workers. (2) The Appalachian province is a northeasterly trending zone of seismic activity extending from northern Virginia to New Brunswick, Canada.

  20. Tidally influenced alongshore circulation at an inlet-adjacent shoreline

    USGS Publications Warehouse

    Hansen, Jeff E.; Elias, Edwin P.L.; List, Jeffrey H.; Erikson, Li H.; Barnard, Patrick L.

    2013-01-01

    The contribution of tidal forcing to alongshore circulation inside the surfzone is investigated at a 7 km long sandy beach adjacent to a large tidal inlet. Ocean Beach in San Francisco, CA (USA) is onshore of a ∼150 km2 ebb-tidal delta and directly south of the Golden Gate, the sole entrance to San Francisco Bay. Using a coupled flow-wave numerical model, we find that the tides modulate, and in some cases can reverse the direction of, surfzone alongshore flows through two separate mechanisms. First, tidal flow through the inlet results in a barotropic tidal pressure gradient that, when integrated across the surfzone, represents an important contribution to the surfzone alongshore force balance. Even during energetic wave conditions, the tidal pressure gradient can account for more than 30% of the total alongshore pressure gradient (wave and tidal components) and up to 55% during small waves. The wave driven component of the alongshore pressure gradient results from alongshore wave height and corresponding setup gradients induced by refraction over the ebb-tidal delta. Second, wave refraction patterns over the inner shelf are tidally modulated as a result of both tidal water depth changes and strong tidal flows (∼1 m/s), with the effect from currents being larger. These tidally induced changes in wave refraction result in corresponding variability of the alongshore radiation stress and pressure gradients within the surfzone. Our results indicate that tidal contributions to the surfzone force balance can be significant and important in determining the direction and magnitude of alongshore flow.

  1. Morphology of pineal glands in human foetuses and infants with brain lesions.

    PubMed

    Laure-Kamionowska, Milena; Maślińska, Danuta; Deregowski, Krzysztof; Czichos, Elzbieta; Raczkowska, Barbara

    2003-01-01

    The pineal gland is an organ involved in regulation of homeostasis and body rhythms. It plays an important role in the growth foetuses and adaptation of newborns to new environmental conditions. The requirements of foetuses and newborns progressively change during development. The purpose of the study was to evaluate morphological changes of pineal glands in foetuses and infants with brain lesions. The results of our study showed that parenchyma of developing pineal glands was susceptible to injury in most autopsied foetal and infantile cases. Morphological changes in pineal glands were found in 90% of autopsied brains but 100% of the cases had infections. The lesions in the pineal included mainly haemorrhagic, necrotic and cystic changes. In our autopsied foetuses and children, morphological changes in pineal glands were concomitant with various lesions of brain parenchyma. All results of our study lead to the conclusion that the pineal gland during its development is very susceptible to injury. The failure of normal pineal gland development and subsequent impaired production of melatonin decrease resistance of newborns and children to various environmental harmful agents.

  2. A 4D CT digital phantom of an individual human brain for perfusion analysis

    PubMed Central

    Brune, Christoph; van Ginneken, Bram; Prokop, Mathias

    2016-01-01

    Brain perfusion is of key importance to assess brain function. Modern CT scanners can acquire perfusion maps of the cerebral parenchyma in vivo at submillimeter resolution. These perfusion maps give insights into the hemodynamics of the cerebral parenchyma and are critical for example for treatment decisions in acute stroke. However, the relations between acquisition parameters, tissue attenuation curves, and perfusion values are still poorly understood and cannot be unraveled by studies involving humans because of ethical concerns. We present a 4D CT digital phantom specific for an individual human brain to analyze these relations in a bottom-up fashion. Validation of the signal and noise components was based on 1,000 phantom simulations of 20 patient imaging data. This framework was applied to quantitatively assess the relation between radiation dose and perfusion values, and to quantify the signal-to-noise ratios of penumbra regions with decreasing sizes in white and gray matter. This is the first 4D CT digital phantom that enables to address clinical questions without having to expose the patient to additional radiation dose. PMID:27917312

  3. Understanding brain, mind and soul: contributions from neurology and neurosurgery.

    PubMed

    Pandya, Sunil K

    2011-01-01

    Treatment of diseases of the brain by drugs or surgery necessitates an understanding of its structure and functions. The philosophical neurosurgeon soon encounters difficulties when localising the abstract concepts of mind and soul within the tangible 1300-gram organ containing 100 billion neurones. Hippocrates had focused attention on the brain as the seat of the mind. The tabula rasa postulated by Aristotle cannot be localised to a particular part of the brain with the confidence that we can localise spoken speech to Broca's area or the movement of limbs to the contralateral motor cortex. Galen's localisation of imagination, reasoning, judgement and memory in the cerebral ventricles collapsed once it was evident that the functional units-neurones-lay in the parenchyma of the brain. Experiences gained from accidental injuries (Phineas Gage) or temporal lobe resection (William Beecher Scoville); studies on how we see and hear and more recent data from functional magnetic resonance studies have made us aware of the extensive network of neurones in the cerebral hemispheres that subserve the functions of the mind. The soul or atman, credited with the ability to enliven the body, was located by ancient anatomists and philosophers in the lungs or heart, in the pineal gland (Descartes), and generally in the brain. When the deeper parts of the brain came within the reach of neurosurgeons, the brainstem proved exceptionally delicate and vulnerable. The concept of brain death after irreversible damage to it has made all of us aware of 'the cocktail of brain soup and spark' in the brainstem so necessary for life. If there be a soul in each of us, surely, it is enshrined here.

  4. Understanding Brain, Mind and Soul: Contributions from Neurology and Neurosurgery

    PubMed Central

    Pandya, Sunil K.

    2011-01-01

    Treatment of diseases of the brain by drugs or surgery necessitates an understanding of its structure and functions. The philosophical neurosurgeon soon encounters difficulties when localising the abstract concepts of mind and soul within the tangible 1300-gram organ containing 100 billion neurones. Hippocrates had focused attention on the brain as the seat of the mind. The tabula rasa postulated by Aristotle cannot be localised to a particular part of the brain with the confidence that we can localise spoken speech to Broca’s area or the movement of limbs to the contralateral motor cortex. Galen’s localisation of imagination, reasoning, judgement and memory in the cerebral ventricles collapsed once it was evident that the functional units–neurones–lay in the parenchyma of the brain. Experiences gained from accidental injuries (Phineas Gage) or temporal lobe resection (William Beecher Scoville); studies on how we see and hear and more recent data from functional magnetic resonance studies have made us aware of the extensive network of neurones in the cerebral hemispheres that subserve the functions of the mind. The soul or atman, credited with the ability to enliven the body, was located by ancient anatomists and philosophers in the lungs or heart, in the pineal gland (Descartes), and generally in the brain. When the deeper parts of the brain came within the reach of neurosurgeons, the brainstem proved exceptionally delicate and vulnerable. The concept of brain death after irreversible damage to it has made all of us aware of ‘the cocktail of brain soup and spark’ in the brainstem so necessary for life. If there be a soul in each of us, surely, it is enshrined here. PMID:21694966

  5. Effects of colistin on amino acid neurotransmitters and blood-brain barrier in the mouse brain.

    PubMed

    Wang, Jian; Yi, Meishuang; Chen, Xueping; Muhammad, Ishfaq; Liu, Fangping; Li, Rui; Li, Jian; Li, Jichang

    2016-01-01

    Neurotoxicity is one of the major potential side effects of colistin therapy. However, the mechanistic aspects of colistin-induced neurotoxicity remain largely unknown. The objective of this study was to examine the effects of colistin on the blood-brain barrier (BBB) and amino acid neurotransmitters in the cerebral cortex of mouse. Mice were divided into four groups (n=5) and were administrated intravenously with 15mg/kg/day of colistin sulfate for 1, 3 and 7days successively while the control group was administrated intravenously with saline solution. The permeability and ultrastructure of the BBB were detected using the Evans blue (EB) dye and transmission electron microscopy (TEM), and the expression of Claudin-5 were determined by real-time PCR examination and western blotting. The brain uptake of colistin was measured by high-performance liquid chromatography (HPLC). The effects of colistin on amino acid neurotransmitters and their receptors were also examined by HPLC and real-time PCR. The results of EB extravasation, TEM and expression of Claudin-5 showed that colistin treatment did not affect the BBB integrity. In addition, multiple doses of colistin could induce accumulation of this compound in the brain parenchyma although there was poor brain uptake of colistin. Moreover, colistin exposure significantly increased the contents of glutamate (Glu) and gamma aminobutyric acid (GABA), and enhanced the mRNA expression levels of gamma aminobutyric acid type A receptor (GABAAR), gamma aminobutyric acid type B receptor (GABABR), N-methyl-d-aspartate 1 receptor (NR1), N-methyl-d-aspartate 2A receptor (NR2A) and N-methyl-d-aspartate 2B receptor (NR2B) in the cerebral cortex. Our data demonstrate that colistin is able to accumulate in the mouse brain and elevate the levels of amino acid neurotransmitters. These findings may be associated with colistin-induced neurotoxicity.

  6. Quantitative Perfusion and Permeability Biomarkers in Brain Cancer from Tomographic CT and MR Images

    PubMed Central

    Eilaghi, Armin; Yeung, Timothy; d’Esterre, Christopher; Bauman, Glenn; Yartsev, Slav; Easaw, Jay; Fainardi, Enrico; Lee, Ting-Yim; Frayne, Richard

    2016-01-01

    Dynamic contrast-enhanced perfusion and permeability imaging, using computed tomography and magnetic resonance systems, are important techniques for assessing the vascular supply and hemodynamics of healthy brain parenchyma and tumors. These techniques can measure blood flow, blood volume, and blood–brain barrier permeability surface area product and, thus, may provide information complementary to clinical and pathological assessments. These have been used as biomarkers to enhance the treatment planning process, to optimize treatment decision-making, and to enable monitoring of the treatment noninvasively. In this review, the principles of magnetic resonance and computed tomography dynamic contrast-enhanced perfusion and permeability imaging are described (with an emphasis on their commonalities), and the potential values of these techniques for differentiating high-grade gliomas from other brain lesions, distinguishing true progression from posttreatment effects, and predicting survival after radiotherapy, chemotherapy, and antiangiogenic treatments are presented. PMID:27398030

  7. The gut microbiota influences blood-brain barrier permeability in mice.

    PubMed

    Braniste, Viorica; Al-Asmakh, Maha; Kowal, Czeslawa; Anuar, Farhana; Abbaspour, Afrouz; Tóth, Miklós; Korecka, Agata; Bakocevic, Nadja; Ng, Lai Guan; Guan, Ng Lai; Kundu, Parag; Gulyás, Balázs; Halldin, Christer; Hultenby, Kjell; Nilsson, Harriet; Hebert, Hans; Volpe, Bruce T; Diamond, Betty; Pettersson, Sven

    2014-11-19

    Pivotal to brain development and function is an intact blood-brain barrier (BBB), which acts as a gatekeeper to control the passage and exchange of molecules and nutrients between the circulatory system and the brain parenchyma. The BBB also ensures homeostasis of the central nervous system (CNS). We report that germ-free mice, beginning with intrauterine life, displayed increased BBB permeability compared to pathogen-free mice with a normal gut flora. The increased BBB permeability was maintained in germ-free mice after birth and during adulthood and was associated with reduced expression of the tight junction proteins occludin and claudin-5, which are known to regulate barrier function in endothelial tissues. Exposure of germ-free adult mice to a pathogen-free gut microbiota decreased BBB permeability and up-regulated the expression of tight junction proteins. Our results suggest that gut microbiota-BBB communication is initiated during gestation and propagated throughout life.

  8. Adjacent tooth trauma in complicated mandibular third molar surgery: Risk degree classification and digital surgical simulation

    PubMed Central

    Ye, Zhou-Xi; Yang, Chi; Ge, Jing

    2016-01-01

    Analysis of adjacent tooth resistance is essential in wisdom teeth extraction to prevent adjacent tooth trauma, however it lacks adequate attention nowadays. This study aims at suggesting special extraction methods based on adjacent tooth resistance analysis for prevention of adjacent tooth damage. In this study, 136 complicated mandibular third molars extracted using piezosurgery were reviewed and classified based on the adjacent teeth resistances shown in orthopantomogram (OPG) during their mesio-distal rotations: degree I refers to teeth with no adjacent teeth resistance; degree II refers to teeth with resistance released after mesial-half crown sectioning; degree III refers to teeth which still had resistance after mesial-half crown sectioning. With the use of surgical simulations using cone beam computerized tomography (CBCT) reconstruction, all teeth in degree I were designed to rotate mesio-distally; 86.36%(38/44) teeth in degree II were designed to rotate mesio-distally after mesio-half crown sectioning; 69.09%(36/55) teeth in degree III were designed to rotate bucco-lingually. All teeth were extracted successfully, and only one adjacent tooth was subluxated due to the incomplete bone removal. Our study suggested that in order to prevent adjacent teeth trauma, complete bone removal is of importance, and impacted teeth with higher adjacent teeth trauma risks should consider bucco-lingual rotations. PMID:27974819

  9. Assessment of polycyclic aromatic hydrocarbon input to urban wetlands in relation to adjacent land use.

    PubMed

    Kimbrough, K L; Dickhut, R M

    2006-11-01

    The relationship between polycyclic aromatic hydrocarbons (PAHs) in wetland surface sediments and adjacent land use was assessed in the Elizabeth River, VA, an urbanized sub-estuary of the Chesapeake Bay. Significant differences (p<0.05) in surface sediment PAH concentration between sites indicated adjacent land use had a substantial influence on PAH concentration in wetland sediments. Wetlands adjacent to parking lots and petroleum industrial sites exhibited the highest PAH concentrations of all wetlands examined. Overall, commercial land uses had the highest PAH concentrations and automotive sources dominated (52-69%) PAH input to wetland surface sediments irrespective of adjacent land use.

  10. Mangroves as a major source of soil carbon storage in adjacent seagrass meadows

    PubMed Central

    Chen, Guangcheng; Azkab, Muhammad Husni; Chmura, Gail L.; Chen, Shunyang; Sastrosuwondo, Pramudji; Ma, Zhiyuan; Dharmawan, I. Wayan Eka; Yin, Xijie; Chen, Bin

    2017-01-01

    Mangrove forests have the potential to export carbon to adjacent ecosystems but whether mangrove-derived organic carbon (OC) would enhance the soil OC storage in seagrass meadows adjacent to mangroves is unclear. In this study we examine the potential for the contribution of mangrove OC to seagrass soils on the coast of North Sulawesi, Indonesia. We found that seagrass meadows adjacent to mangroves had significantly higher soil OC concentrations, soil OC with lower δ 13C, and lower bulk density than those at the non-mangrove adjacent meadows. Soil OC storage to 30 cm depth ranged from 3.21 to 6.82 kg C m−2, and was also significantly higher at the mangrove adjacent meadows than those non-adjacent meadows. δ13C analyses revealed that mangrove OC contributed 34 to 83% to soil OC at the mangrove adjacent meadows. The δ13C value of seagrass plants was also different between the seagrasses adjacent to mangroves and those which were not, with lower values measured at the seagrasses adjacent to mangroves. Moreover, we found significant spatial variation in both soil OC concentration and storage, with values decreasing toward sea, and the contribution of mangrove-derived carbon also reduced with distance from the forest. PMID:28186151

  11. Mangroves as a major source of soil carbon storage in adjacent seagrass meadows

    NASA Astrophysics Data System (ADS)

    Chen, Guangcheng; Azkab, Muhammad Husni; Chmura, Gail L.; Chen, Shunyang; Sastrosuwondo, Pramudji; Ma, Zhiyuan; Dharmawan, I. Wayan Eka; Yin, Xijie; Chen, Bin

    2017-02-01

    Mangrove forests have the potential to export carbon to adjacent ecosystems but whether mangrove-derived organic carbon (OC) would enhance the soil OC storage in seagrass meadows adjacent to mangroves is unclear. In this study we examine the potential for the contribution of mangrove OC to seagrass soils on the coast of North Sulawesi, Indonesia. We found that seagrass meadows adjacent to mangroves had significantly higher soil OC concentrations, soil OC with lower δ 13C, and lower bulk density than those at the non-mangrove adjacent meadows. Soil OC storage to 30 cm depth ranged from 3.21 to 6.82 kg C m‑2, and was also significantly higher at the mangrove adjacent meadows than those non-adjacent meadows. δ13C analyses revealed that mangrove OC contributed 34 to 83% to soil OC at the mangrove adjacent meadows. The δ13C value of seagrass plants was also different between the seagrasses adjacent to mangroves and those which were not, with lower values measured at the seagrasses adjacent to mangroves. Moreover, we found significant spatial variation in both soil OC concentration and storage, with values decreasing toward sea, and the contribution of mangrove-derived carbon also reduced with distance from the forest.

  12. Brain heterotopia.

    PubMed

    Modarresifar, Homayoun; Ho, Linh

    2009-03-01

    We present a case with intractable partial complex seizures in a 14-year-old girl who was found to have brain heterotopia on MRI and PET-CT. The patient presented with intractable partial complex seizures and a normal electroencephalogram. Her brain magnetic resonance imaging showed heterotopic gray matter lining the ventricular margin of the right occipital horn. Subsequent PET-CT demonstrated moderate tracer localization in the heterotopic gray matter surrounding the ventricular margin of the right occipital horn. Heterotopia may demonstrate normal or increased FDG uptake on PET, therefore its appearance may be deceiving when other pathologies are being considered.

  13. Impairment of Glymphatic Pathway Function Promotes Tau Pathology after Traumatic Brain Injury

    PubMed Central

    Chen, Michael J.; Plog, Benjamin A.; Zeppenfeld, Douglas M.; Soltero, Melissa; Yang, Lijun; Singh, Itender; Deane, Rashid; Nedergaard, Maiken

    2014-01-01

    Traumatic brain injury (TBI) is an established risk factor for the early development of dementia, including Alzheimer's disease, and the post-traumatic brain frequently exhibits neurofibrillary tangles comprised of aggregates of the protein tau. We have recently defined a brain-wide network of paravascular channels, termed the “glymphatic” pathway, along which CSF moves into and through the brain parenchyma, facilitating the clearance of interstitial solutes, including amyloid-β, from the brain. Here we demonstrate in mice that extracellular tau is cleared from the brain along these paravascular pathways. After TBI, glymphatic pathway function was reduced by ∼60%, with this impairment persisting for at least 1 month post injury. Genetic knock-out of the gene encoding the astroglial water channel aquaporin-4, which is importantly involved in paravascular interstitial solute clearance, exacerbated glymphatic pathway dysfunction after TBI and promoted the development of neurofibrillary pathology and neurodegeneration in the post-traumatic brain. These findings suggest that chronic impairment of glymphatic pathway function after TBI may be a key factor that renders the post-traumatic brain vulnerable to tau aggregation and the onset of neurodegeneration. PMID:25471560

  14. Extensive vascular mineralization in the brain of a chimpanzee (Pan troglodytes).

    PubMed

    Connor-Stroud, Fawn R; Hopkins, William D; Preuss, Todd M; Johnson, Zachary; Zhang, Xiaodong; Sharma, Prachi

    2014-06-01

    Spontaneous vascular mineralization (deposition of iron or calcium salts) has been observed in marble brain syndrome, mineralizing microangiopathy, hypothyroidism, Fahr syndrome, Sturge-Weber syndrome, cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy, and calciphylaxis in humans and as an aging or idiopathic lesion in the brains of horses, cats, nonhuman primates, mice, rats, cattle, white-tailed deer, and dogs. Here we present a 27-y-old, adult male chimpanzee (Pan troglodytes) with spontaneous, extensive vascular mineralization localized solely to the brain. The chimpanzee exhibited tremors and weakness of the limbs, which progressed to paralysis before euthanasia. Magnetic resonance brain imaging in 2002 and 2010 (immediately before euthanasia) revealed multiple hypointense foci, suggestive of iron- and calcium-rich deposits. At necropsy, the brain parenchyma had occasional petechial hemorrhage, and microscopically, the cerebral, cerebellar and brain stem, gray and white matter had moderate to severe mural aggregates of a granular, basophilic material (mineral) in the blood vessels. In addition, these regions often had moderate to severe medial to transmural deposition of mature collagen in the blood vessels. We ruled out common causes of brain mineralization in humans and animals, but an etiology for the mineralization could not be determined. To our knowledge, mineralization in brain has been reported only once to occur in a chimpanzee, but its chronicity in our case makes it particularly interesting.

  15. Seismotectonics of northeastern United States and adjacent Canada

    NASA Astrophysics Data System (ADS)

    Yang, Jih-Ping; Aggarwal, Yash Pal

    1981-06-01

    Data for local earthquakes recorded by a network of stations in northeastern United States and adjacent Canada were analyzed to study the seismicity, the relationship between earthquakes and known faults, the state of stress, and crustal and upper mantle velocity structure. In addition, portable seismographs were deployed in the field to study aftershocks. As a result, accurate locations for about 364 local earthquakes (2 ≤ mb ≤ 5) and 22 focal mechanism solutions were determined. A comparison of the spatial distribution of these events (1970-1979) with historical earthquakes (1534-1959) reveals that seismic activity in the northeast is relatively stationary in space: those areas that have had little or no seismicity historically are relatively aseismic today, whereas the historically active areas are also active today. The instrumental locations, historical seismicity, and focal mechanism solutions show an internal consistency that help us distinguish two distinct seismogenic provinces. (1) The Adirondack-western Quebec province is a northwesterly trending zone of seismic activity, about 200 km wide and at least 500 km long, extending from the SE Adirondacks into western Quebec, Canada. Thrust faulting on planes striking NNW to NW appears to predominate, and the inferred axis of maximum horizontal compression is largely uniform and trends WSW, nearly parallel to the calculated absolute plate motion of North America. Little or no seismicity is found where anorthosite outcrops at the surface. Correlations between gravity anomalies and earthquake locations suggest that seismic activity in this zone is localized to regions of steep NE or SW gradient in Bouguer anomalies. This zone does not appear to extend southeastward to Boston, as proposed by some workers. (2) The Appalachian province is a northeasterly trending zone of seismic activity extending from northern Virginia to New Brunswick, Canada. Highangle reverse or thrust faulting on N to NE trending planes

  16. Whole-brain black-blood imaging with magnetization-transfer prepared spin echo-like contrast: a novel sequence for contrast-enhanced brain metastasis screening at 3T.

    PubMed

    Yoneyama, Masami; Nakamura, Masanobu; Tabuchi, Takashi; Takemura, Atsushi; Obara, Makoto; Tatsuno, Satoshi; Sawano, Seishi

    2013-07-01

    In contrast-enhanced (CE) brain metastasis screening, coexistence of enhanced blood vessel suppression and higher tumor-to-parenchyma contrast may improve radiologists' performances in detecting brain metastases compared with conventional sequences. In this study, we propose a new scheme, allowing both suppression of blood signals and improvement of tumor-to-parenchyma contrast, using motion-sensitized driven equilibrium prepared 3D low-refocusing flip-angle turbo spin echo (TSE) ("magnetization transfer prepared spin echo"-like contrast volume examination: MATLVE) for brain metastasis screening at 3.0 T, and we compare MATLVE to conventional three-dimensional (3D)-gradient recalled echo (GRE) and 3D-TSE sequences. With the use of MATLVE, the signal intensity of CE blood decreased substantially. Furthermore, the contrast ratio of tumor-to-white matter was significantly higher than in either conventional 3D-GRE or 3D-TSE. MATLVE can be used for 3D volumetric post-CE black-blood imaging, and it may be effective in detecting small brain metastases by selectively enhancing tumor signals while suppressing blood signals.

  17. Smart Brains.

    ERIC Educational Resources Information Center

    Jones, Rebecca

    1995-01-01

    New techniques have opened windows to the brain. Although the biochemistry of learning remains largely a mystery, the following findings seem to have clear implications for education: (1) the importance of early-learning opportunities for the very young; (2) the connection between music and abstract reasoning; and (3) the importance of good…

  18. Animating Brains.

    PubMed

    Borck, Cornelius

    2016-07-01

    A recent paper famously accused the rising field of social neuroscience of using faulty statistics under the catchy title 'Voodoo Correlations in Social Neuroscience'. This Special Issue invites us to take this claim as the starting point for a cross-cultural analysis: in which meaningful ways can recent research in the burgeoning field of functional imaging be described as, contrasted with, or simply compared to animistic practices? And what light does such a reading shed on the dynamics and effectiveness of a century of brain research into higher mental functions? Reviewing the heated debate from 2009 around recent trends in neuroimaging as a possible candidate for current instances of 'soul catching', the paper will then compare these forms of primarily image-based brain research with older regimes, revolving around the deciphering of the brain's electrical activity. How has the move from a decoding paradigm to a representational regime affected the conceptualisation of self, psyche, mind and soul (if there still is such an entity)? And in what ways does modern technoscience provide new tools for animating brains?

  19. Exploring the Biomechanical Properties of Brain Malignancies and their Pathological Determinants In Vivo with Magnetic Resonance Elastography

    PubMed Central

    Popov, Sergey; Garteiser, Philippe; Ulloa, Jose L.; Cummings, Craig; Box, Gary; Eccles, Suzanne A.; Jones, Chris; Waterton, John C.; Bamber, Jeffrey C.; Sinkus, Ralph; Robinson, Simon P.

    2015-01-01

    Malignant tumors are typically associated with altered rigidity relative to normal host tissue. Magnetic resonance elastography (MRE) enables the noninvasive quantitation of the mechanical properties of deep-seated tissue following application of an external vibrational mechanical stress to that tissue. In this preclinical study, we used MRE to quantify (kPa) the elasticity modulus Gd and viscosity modulus Gl of three intracranially implanted glioma and breast metastatic tumor models. In all these brain tumors, we found a notable softness characterized by lower elasticity and viscosity than normal brain parenchyma, enabling their detection on Gd and Gl parametric maps. The most circumscribed tumor (U-87 glioma) was the stiffest whereas the most infiltrative tumor (MDA-MB-231 metastatic breast carcinoma) was the softest. Tumor cell density and microvessel density correlated positively with elasticity and viscosity significantly, whereas there was no association with the extent of collagen deposition or myelin fiber entrapment. In conclusion, while malignant tumors tend to exhibit increased rigidity, intracranial tumors presented as remarkably softer than normal brain parenchyma. Our findings reinforce the case for MRE use in diagnosing and staging brain malignancies, based on the association of different tumor phenotypes with different mechanical properties. PMID:25672978

  20. Gene Transfer into Rat Brain Using Adenoviral Vectors

    PubMed Central

    Puntel, Mariana; Kroeger, Kurt M.; Sanderson, Nicholas S.R.; Thomas, Clare E.; Castro, Maria G.; Lowenstein, Pedro R.

    2010-01-01

    Viral vector–mediated gene delivery is an attractive procedure for introducing genes into the brain, both for purposes of basic neuroscience research and to develop gene therapy for neurological diseases. Replication-defective adenoviruses possess many features which make them ideal vectors for this purpose—efficiently transducing terminally differentiated cells such as neurons and glial cells, resulting in high levels of transgene expression in vivo. Also, in the absence of anti-adenovirus immunity, these vectors can sustain very long-term transgene expression within the brain parenchyma. This unit provides protocols for the stereotactic injection of adenoviral vectors into the brain, followed by protocols to detect transgene expression or infiltrates of immune cells by immunocytochemistry or immunofluorescence. ELISPOT and neutralizing antibody assay methodologies are provided to quantitate the levels of cellular and humoral immune responses against adenoviruses. Quantitation of adenoviral vector genomes within the rat brain using qPCR is also described. Curr. Protoc. Neurosci. 50:4.24.1–4.24.49. © 2010 by John Wiley & Sons, Inc. PMID:20066657

  1. Neuroimaging of Cerebrovascular Disease in the Aging Brain

    PubMed Central

    Gupta, Ajay; Nair, Sreejit; Schweitzer, Andrew D.; Kishore, Sirish; Johnson, Carl E.; Comunale, Joseph P.; Tsiouris, Apostolos J.; Sanelli, Pina C.

    2012-01-01

    Cerebrovascular disease remains a significant public health burden with its greatest impact on the elderly population. Advances in neuroimaging techniques allow detailed and sophisticated evaluation of many manifestations of cerebrovascular disease in the brain parenchyma as well as in the intracranial and extracranial vasculature. These tools continue to contribute to our understanding of the multifactorial processes that occur in the age-dependent development of cerebrovascular disease. Structural abnormalities related to vascular disease in the brain and vessels have been well characterized with CT and MRI based techniques. We review some of the pathophysiologic mechanisms in the aging brain and cerebral vasculature and the related structural abnormalities detectable on neuroimaging, including evaluation of age-related white matter changes, atherosclerosis of the cerebral vasculature, and cerebral infarction. In addition, newer neuroimaging techniques, such as diffusion tensor imaging, perfusion techniques, and assessment of cerebrovascular reserve, are also reviewed, as these techniques can detect physiologic alterations which complement the morphologic changes that cause cerebrovascular disease in the aging brain.Further investigation of these advanced imaging techniques has potential application to the understanding and diagnosis of cerebrovascular disease in the elderly. PMID:23185721

  2. Brain mast cell relationship to neurovasculature during development.

    PubMed

    Khalil, Mona; Ronda, Jocelyn; Weintraub, Michael; Jain, Kim; Silver, Rae; Silverman, Ann-Judith

    2007-09-26

    Mast cells, derived from the hematopoietic stem cell, are present in the brain from birth. During development, mast cells occur in two locations, namely the pia and the brain parenchyma. The current hypothesis regarding their origin states that brain mast cells (or their precursors) enter the pia and access the thalamus by traveling along the abluminal wall of penetrating blood vessels. The population in the pia reaches a maximum at postnatal (PN) day 11, and declines rapidly thereafter. Chromatin fragmentation suggests that this cell loss is due to apoptosis. In contrast, the thalamic population expands from PN8 to reach adult levels at PN30. Stereological analysis demonstrates that mast cells home to blood vessels. More than 96% of mast cells are inside the blood-brain barrier, with ~90% contacting the blood vessel wall or its extracellular matrix. Mast cells express alpha4 integrins -- a potential mechanism for adhesion to the vascular wall. Despite the steady increase in the volume of microvasculature, at all ages studied, mast cells are preferentially located on large diameter vessels (>16 microm; possibly arteries), and contact only those maturing blood vessels that are ensheathed by astroglial processes. Mast cells not only home to large vessels but also maintain a preferential position at branch points, sites of vessel growth. This observation presents the possibility that mast cells participate in and/or regulate vasculature growth or differentiation. The biochemical and molecular signals that induce mast cell homing in the CNS is an area of active investigation.

  3. Critical Care Management of Cerebral Edema in Brain Tumors.

    PubMed

    Esquenazi, Yoshua; Lo, Victor P; Lee, Kiwon

    2017-01-01

    Cerebral edema associated with brain tumors is extremely common and can occur in both primary and metastatic tumors. The edema surrounding brain tumors results from leakage of plasma across the vessel wall into the parenchyma secondary to disruption of the blood-brain barrier. The clinical signs of brain tumor edema depend on the location of the tumor as well as the extent of the edema, which often exceeds the mass effect induced by the tumor itself. Uncontrolled cerebral edema may result in increased intracranial pressure and acute herniation syndromes that can result in permanent neurological dysfunction and potentially fatal herniation. Treatment strategies for elevated intracranial pressure consist of general measures, medical interventions, and surgery. Alhough the definitive treatment for the edema may ultimately be surgical resection of the tumor, the impact of the critical care management cannot be underestimated and thus patients must be vigilantly monitored in the intensive care unit. In this review, we discuss the pathology, pathophysiology, and clinical features of patients presenting with cerebral edema. Imaging findings and treatment modalities used in the intensive care unit are also discussed.

  4. Brain Tumors (For Parents)

    MedlinePlus

    ... Old Feeding Your 1- to 2-Year-Old Brain Tumors KidsHealth > For Parents > Brain Tumors Print A ... radiation therapy or chemotherapy, or both. Types of Brain Tumors There are many different types of brain ...

  5. Understanding Brain Tumors

    MedlinePlus

    ... to Know About Brain Tumors . What is a Brain Tumor? A brain tumor is an abnormal growth
 ... Tumors” from Frankly Speaking Frankly Speaking About Cancer: Brain Tumors Download the full book Questions to ask ...

  6. Brain tumor - children

    MedlinePlus

    ... children; Neuroglioma - children; Oligodendroglioma - children; Meningioma - children; Cancer - brain tumor (children) ... The cause of primary brain tumors is unknown. Primary brain tumors may ... (spread to nearby areas) Cancerous (malignant) Brain tumors ...

  7. Brain Tumors (For Parents)

    MedlinePlus

    ... Old Feeding Your 1- to 2-Year-Old Brain Tumors KidsHealth > For Parents > Brain Tumors A A ... radiation therapy or chemotherapy, or both. Types of Brain Tumors There are many different types of brain ...

  8. Brain Tumor Diagnosis

    MedlinePlus

    ... Types of Brain Scans X-rays Laboratory Tests DNA Profiling Biopsy Procedure Malignant and Benign Brain Tumors Tumor ... Types of Brain Scans X-rays Laboratory Tests DNA Profiling Biopsy Procedure Malignant and Benign Brain Tumors Tumor ...

  9. Intrathecal antibodies and brain damage in autoimmune MRL mice.

    PubMed

    Stanojcic, Mile; Loheswaran, Genane; Xu, Li; Hoffman, Steven A; Sakic, Boris

    2010-02-01

    Neuropsychiatric (NP) manifestations and brain pathology are poorly understood and potentially fatal concomitants of systemic lupus erythematosus (SLE). For many years, autoantibodies to brain tissue (i.e., brain-reactive antibodies, BRA) were proposed as a key factor in pathogenesis of CNS manifestations. Recent evidence suggests that intrathecal BRA, rather than serum autoantibodies, are a better predictor of disturbed brain morphology and function. We presently test this hypothesis by examining the relationship among BRA in cerebrospinal fluid (CSF), behavioral deficits, and brain pathology in a well-established animal model of CNS lupus. We showed earlier that significant diversity in disease manifestations within genetically homogenous MRL-lpr mice allows for constructive and informative correlational analysis. Therefore, levels of CSF antibodies were presently correlated with behavioral, neuropathological and immune measures in a cohort of diseased MRL-lpr males (N=40). ELISA, Western Blotting, standardized behavioral battery, digital planimetry, HE staining, and immunohistochemistry were employed in overall data collection. The IgG antibodies from CSF were binding to different regions of brain parenchyma, with dentate gyrus, amygdale, and subventricular zones showing enhanced immunoreactivity. High levels of CSF antibodies correlated with increased immobility in the forced-swim test and density of HE(+) cells in the paraventricular nucleus. Peripheral measures of autoimmunity were associated with other deficits in behavior and neuropathology. This correlation pattern suggests that etiology of brain damage in lupus-prone mice is multifactorial. Intrathecal BRA may be important in altering motivated responses and activity of major neuroendocrine axes at the onset of SLE-like disease.

  10. Histamine Induces Alzheimer's Disease-Like Blood Brain Barrier Breach and Local Cellular Responses in Mouse Brain Organotypic Cultures

    PubMed Central

    Sedeyn, Jonathan C.; Wu, Hao; Hobbs, Reilly D.; Levin, Eli C.; Nagele, Robert G.; Venkataraman, Venkat

    2015-01-01

    Among the top ten causes of death in the United States, Alzheimer's disease (AD) is the only one that cannot be cured, prevented, or even slowed down at present. Significant efforts have been exerted in generating model systems to delineate the mechanism as well as establishing platforms for drug screening. In this study, a promising candidate model utilizing primary mouse brain organotypic (MBO) cultures is reported. For the first time, we have demonstrated that the MBO cultures exhibit increased blood brain barrier (BBB) permeability as shown by IgG leakage into the brain parenchyma, astrocyte activation as evidenced by increased expression of glial fibrillary acidic protein (GFAP), and neuronal damage-response as suggested by increased vimentin-positive neurons occur upon histamine treatment. Identical responses—a breakdown of the BBB, astrocyte activation, and neuronal expression of vimentin—were then demonstrated in brains from AD patients compared to age-matched controls, consistent with other reports. Thus, the histamine-treated MBO culture system may provide a valuable tool in combating AD. PMID:26697497

  11. Novel use of polymerase chain reaction to amplify cellular DNA adjacent to an integrated provirus.

    PubMed Central

    Silver, J; Keerikatte, V

    1989-01-01

    We describe a modification of the polymerase chain reaction technique which allows amplification of cellular DNA adjacent to an integrated provirus given sequence information for the provirus only. The modified technique should be generally useful for studies of insertional mutagenesis and other situations in which one wishes to isolate DNA adjacent to a region of known sequence. Images PMID:2704070

  12. 33 CFR 162.215 - Lake Tahoe, Nev.; restricted area adjacent to Nevada Beach.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Lake Tahoe, Nev.; restricted area adjacent to Nevada Beach. 162.215 Section 162.215 Navigation and Navigable Waters COAST GUARD, DEPARTMENT... § 162.215 Lake Tahoe, Nev.; restricted area adjacent to Nevada Beach. (a) The restricted area....

  13. 33 CFR 162.215 - Lake Tahoe, Nev.; restricted area adjacent to Nevada Beach.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Lake Tahoe, Nev.; restricted area adjacent to Nevada Beach. 162.215 Section 162.215 Navigation and Navigable Waters COAST GUARD, DEPARTMENT... § 162.215 Lake Tahoe, Nev.; restricted area adjacent to Nevada Beach. (a) The restricted area....

  14. 33 CFR 162.215 - Lake Tahoe, Nev.; restricted area adjacent to Nevada Beach.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Lake Tahoe, Nev.; restricted area adjacent to Nevada Beach. 162.215 Section 162.215 Navigation and Navigable Waters COAST GUARD, DEPARTMENT... § 162.215 Lake Tahoe, Nev.; restricted area adjacent to Nevada Beach. (a) The restricted area....

  15. 33 CFR 162.215 - Lake Tahoe, Nev.; restricted area adjacent to Nevada Beach.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Lake Tahoe, Nev.; restricted area adjacent to Nevada Beach. 162.215 Section 162.215 Navigation and Navigable Waters COAST GUARD, DEPARTMENT... § 162.215 Lake Tahoe, Nev.; restricted area adjacent to Nevada Beach. (a) The restricted area....

  16. 33 CFR 162.215 - Lake Tahoe, Nev.; restricted area adjacent to Nevada Beach.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Lake Tahoe, Nev.; restricted area adjacent to Nevada Beach. 162.215 Section 162.215 Navigation and Navigable Waters COAST GUARD, DEPARTMENT... § 162.215 Lake Tahoe, Nev.; restricted area adjacent to Nevada Beach. (a) The restricted area....

  17. 47 CFR 101.1421 - Coordination of adjacent area MVDDS stations.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... and architecture of their systems, in order to ensure that no harmful interference occurs between...) Cooperate fully and in good faith to resolve interference and transmission problems that are present on adjacent and co-channel operations in adjacent areas. (b) Harmful interference to public safety...

  18. 47 CFR 101.1421 - Coordination of adjacent area MVDDS stations.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... and architecture of their systems, in order to ensure that no harmful interference occurs between...) Cooperate fully and in good faith to resolve interference and transmission problems that are present on adjacent and co-channel operations in adjacent areas. (b) Harmful interference to public safety...

  19. 47 CFR 101.1421 - Coordination of adjacent area MVDDS stations.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... and architecture of their systems, in order to ensure that no harmful interference occurs between...) Cooperate fully and in good faith to resolve interference and transmission problems that are present on adjacent and co-channel operations in adjacent areas. (b) Harmful interference to public safety...

  20. Variable length adjacent partitioning for PTS based PAPR reduction of OFDM signal

    SciTech Connect

    Ibraheem, Zeyid T.; Rahman, Md. Mijanur; Yaakob, S. N.; Razalli, Mohammad Shahrazel; Kadhim, Rasim A.

    2015-05-15

    Peak-to-Average power ratio (PAPR) is a major drawback in OFDM communication. It leads the power amplifier into nonlinear region operation resulting into loss of data integrity. As such, there is a strong motivation to find techniques to reduce PAPR. Partial Transmit Sequence (PTS) is an attractive scheme for this purpose. Judicious partitioning the OFDM data frame into disjoint subsets is a pivotal component of any PTS scheme. Out of the existing partitioning techniques, adjacent partitioning is characterized by an attractive trade-off between cost and performance. With an aim of determining effects of length variability of adjacent partitions, we performed an investigation into the performances of a variable length adjacent partitioning (VL-AP) and fixed length adjacent partitioning in comparison with other partitioning schemes such as pseudorandom partitioning. Simulation results with different modulation and partitioning scenarios showed that fixed length adjacent partition had better performance compared to variable length adjacent partitioning. As expected, simulation results showed a slightly better performance of pseudorandom partitioning technique compared to fixed and variable adjacent partitioning schemes. However, as the pseudorandom technique incurs high computational complexities, adjacent partitioning schemes were still seen as favorable candidates for PAPR reduction.

  1. 33 CFR 165.1303 - Puget Sound and adjacent waters, WA-regulated navigation area.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Puget Sound and adjacent waters... § 165.1303 Puget Sound and adjacent waters, WA—regulated navigation area. (a) The following is a... Light to New Dungeness Light and all points in the Puget Sound area north and south of these lights....

  2. 33 CFR 165.1303 - Puget Sound and adjacent waters, WA-regulated navigation area.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Puget Sound and adjacent waters... § 165.1303 Puget Sound and adjacent waters, WA—regulated navigation area. (a) The following is a... Light to New Dungeness Light and all points in the Puget Sound area north and south of these lights....

  3. 33 CFR 165.1303 - Puget Sound and adjacent waters, WA-regulated navigation area.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Puget Sound and adjacent waters... § 165.1303 Puget Sound and adjacent waters, WA—regulated navigation area. (a) The following is a... Light to New Dungeness Light and all points in the Puget Sound area north and south of these lights....

  4. 33 CFR 165.1303 - Puget Sound and adjacent waters, WA-regulated navigation area.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Puget Sound and adjacent waters... § 165.1303 Puget Sound and adjacent waters, WA—regulated navigation area. (a) The following is a... Light to New Dungeness Light and all points in the Puget Sound area north and south of these lights....

  5. 33 CFR 165.1303 - Puget Sound and adjacent waters, WA-regulated navigation area.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Puget Sound and adjacent waters... § 165.1303 Puget Sound and adjacent waters, WA—regulated navigation area. (a) The following is a... Light to New Dungeness Light and all points in the Puget Sound area north and south of these lights....

  6. Let's Not Waste Time: Using Temporal Information in Clustered Activity Estimation with Spatial Adjacency Restrictions (CAESAR) for Parcellating FMRI Data.

    PubMed

    Janssen, Ronald J; Jylänki, Pasi; van Gerven, Marcel A J

    2016-01-01

    We have proposed a Bayesian approach for functional parcellation of whole-brain FMRI measurements which we call Clustered Activity Estimation with Spatial Adjacency Restrictions (CAESAR). We use distance-dependent Chinese restaurant processes (dd-CRPs) to define a flexible prior which partitions the voxel measurements into clusters whose number and shapes are unknown a priori. With dd-CRPs we can conveniently implement spatial constraints to ensure that our parcellations remain spatially contiguous and thereby physiologically meaningful. In the present work, we extend CAESAR by using Gaussian process (GP) priors to model the temporally smooth haemodynamic signals that give rise to the measured FMRI data. A challenge for GP inference in our setting is the cubic scaling with respect to the number of time points, which can become computationally prohibitive with FMRI measurements, potentially consisting of long time series. As a solution we describe an efficient implementation that is practically as fast as the corresponding time-independent non-GP model with typically-sized FMRI data sets. We also employ a population Monte-Carlo algorithm that can significantly speed up convergence compared to traditional single-chain methods. First we illustrate the benefits of CAESAR and the GP priors with simulated experiments. Next, we demonstrate our approach by parcellating resting state FMRI data measured from twenty participants as taken from the Human Connectome Project data repository. Results show that CAESAR affords highly robust and scalable whole-brain clustering of FMRI timecourses.

  7. The Creative Brain.

    ERIC Educational Resources Information Center

    Herrmann, Ned

    1982-01-01

    Outlines the differences between left-brain and right-brain functioning and between left-brain and right-brain dominant individuals, and concludes that creativity uses both halves of the brain. Discusses how both students and curriculum can become more "whole-brained." (Author/JM)

  8. Assessment of heavy metal levels in surface sediments of estuaries and adjacent coastal areas in China

    NASA Astrophysics Data System (ADS)

    Liu, Xianbin; Li, Deliang; Song, Guisheng

    2017-03-01

    This article investigates the variations of contamination levels of heavy metals such as copper, lead, chromium, cadmium, zinc, arsenic, and mercury over time in surface sediments of the Changjiang River Estuary (CRE), Yellow River Estuary (YRE), Pearl River Estuary (PRE), and their adjacent coastal areas in China. The contamination factor (CF), pollution load index (PLI), and geoaccumulation index ( I geo) are used to evaluate the quality of the surface sediments in the study areas. The results showed that the CRE, YRE, and their adjacent coastal areas were at a low risk of contamination in terms of heavy metals, while the PRE and its adjacent coastal area were at a moderate level. By comparison, the concentrations of heavy metals in the surface sediments of the YRE and its adjacent coastal area were relatively lower than those in the CRE, PRE, and their adjacent coastal areas.

  9. Assessment of heavy metal levels in surface sediments of estuaries and adjacent coastal areas in China

    NASA Astrophysics Data System (ADS)

    Liu, Xianbin; Li, Deliang; Song, Guisheng

    2016-05-01

    This article investigates the variations of contamination levels of heavy metals such as copper, lead, chromium, cadmium, zinc, arsenic, and mercury over time in surface sediments of the Changjiang River Estuary (CRE), Yellow River Estuary (YRE), Pearl River Estuary (PRE), and their adjacent coastal areas in China. The contamination factor (CF), pollution load index (PLI), and geoaccumulation index (I geo) are used to evaluate the quality of the surface sediments in the study areas. The results showed that the CRE, YRE, and their adjacent coastal areas were at a low risk of contamination in terms of heavy metals, while the PRE and its adjacent coastal area were at a moderate level. By comparison, the concentrations of heavy metals in the surface sediments of the YRE and its adjacent coastal area were relatively lower than those in the CRE, PRE, and their adjacent coastal areas.

  10. Seismic analysis of adjacent buildings subjected to double pounding considering soil-structure interaction

    NASA Astrophysics Data System (ADS)

    Farghaly, Ahmed Abdelraheem

    2017-02-01

    A 2D model of two adjacent buildings with different heights (6 and 12 floors) and foundation levels without separation distance under seismic load and considering SSI is investigated. A special arrangement of contact elements (gap elements) each 1 m of the low height building in the contact zone is taken into consideration to fulfill all possible deformation contact modes which take place under seismic load (earthquake). Soil is modeled by 2D shell elements in contact with foundations of the two adjacent buildings. This paper focuses on the study of double pounding that takes place between the two adjacent buildings in some upper points at superstructure in the contact zone and also at foundation level. The forces of double pounding between the two adjacent buildings, which increase by softening of the soil, give a valuable assessment of straining actions of the two adjacent buildings and change the behavior of soil under the foundations and around basement floor.

  11. Seismic analysis of adjacent buildings subjected to double pounding considering soil-structure interaction

    NASA Astrophysics Data System (ADS)

    Farghaly, Ahmed Abdelraheem

    2017-03-01

    A 2D model of two adjacent buildings with different heights (6 and 12 floors) and foundation levels without separation distance under seismic load and considering SSI is investigated. A special arrangement of contact elements (gap elements) each 1 m of the low height building in the contact zone is taken into consideration to fulfill all possible deformation contact modes which take place under seismic load (earthquake). Soil is modeled by 2D shell elements in contact with foundations of the two adjacent buildings. This paper focuses on the study of double pounding that takes place between the two adjacent buildings in some upper points at superstructure in the contact zone and also at foundation level. The forces of double pounding between the two adjacent buildings, which increase by softening of the soil, give a valuable assessment of straining actions of the two adjacent buildings and change the behavior of soil under the foundations and around basement floor.

  12. Martian 'Brain'

    NASA Technical Reports Server (NTRS)

    2004-01-01

    5 May 2004 Most middle-latitude craters on Mars have strange landforms on their floors. Often, the floors have pitted and convoluted features that lack simple explanation. In this case, the central part of the crater floor shown in this 2004 Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image bears some resemblance to the folded nature of a brain. Or not. It depends upon the 'eye of the beholder,' perhaps. The light-toned 'ring' around the 'brain' feature is more easily explained--windblown ripples and dunes. The crater occurs near 33.1oS, 91.2oW, and is illuminated from the upper left. The picture covers an area about 3 km (1.9 mi) across.

  13. Silicon Brains

    NASA Astrophysics Data System (ADS)

    Hoefflinger, Bernd

    Beyond the digital neural networks of Chap. 16, the more radical mapping of brain-like structures and processes into VLSI substrates has been pioneered by Carver Mead more than 30 years ago [1]. The basic idea was to exploit the massive parallelism of such circuits and to create low-power and fault-tolerant information-processing systems. Neuromorphic engineering has recently seen a revival with the availability of deep-submicron CMOS technology, which allows for the construction of very-large-scale mixed-signal systems combining local analog processing in neuronal cells with binary signalling via action potentials. Modern implementations are able to reach the complexity-scale of large functional units of the human brain, and they feature the ability to learn by plasticity mechanisms found in neuroscience. Combined with high-performance programmable logic and elaborate software tools, such systems are currently evolving into user-configurable non-von-Neumann computing systems, which can be used to implement and test novel computational paradigms. The chapter introduces basic properties of biological brains with up to 200 Billion neurons and their 1014 synapses, where action on a synapse takes ˜10 ms and involves an energy of ˜10 fJ. We outline 10x programs on neuromorphic electronic systems in Europe and the USA, which are intended to integrate 108 neurons and 1012 synapses, the level of a cat's brain, in a volume of 1 L and with a power dissipation <1 kW. For a balanced view on intelligence, we references Hawkins' view to first perceive the task and then design an intelligent technical response.

  14. Brain imaging

    SciTech Connect

    Bradshaw, J.R.

    1989-01-01

    This book presents a survey of the various imaging tools with examples of the different diseases shown best with each modality. It includes 100 case presentations covering the gamut of brain diseases. These examples are grouped according to the clinical presentation of the patient: headache, acute headache, sudden unilateral weakness, unilateral weakness of gradual onset, speech disorders, seizures, pituitary and parasellar lesions, sensory disorders, posterior fossa and cranial nerve disorders, dementia, and congenital lesions.

  15. Animating Brains

    PubMed Central

    Borck, Cornelius

    2016-01-01

    A recent paper famously accused the rising field of social neuroscience of using faulty statistics under the catchy title ‘Voodoo Correlations in Social Neuroscience’. This Special Issue invites us to take this claim as the starting point for a cross-cultural analysis: in which meaningful ways can recent research in the burgeoning field of functional imaging be described as, contrasted with, or simply compared to animistic practices? And what light does such a reading shed on the dynamics and effectiveness of a century of brain research into higher mental functions? Reviewing the heated debate from 2009 around recent trends in neuroimaging as a possible candidate for current instances of ‘soul catching’, the paper will then compare these forms of primarily image-based brain research with older regimes, revolving around the deciphering of the brain’s electrical activity. How has the move from a decoding paradigm to a representational regime affected the conceptualisation of self, psyche, mind and soul (if there still is such an entity)? And in what ways does modern technoscience provide new tools for animating brains? PMID:27292322

  16. Ischemia-reperfusion impairs blood-brain barrier function and alters tight junction protein expression in the ovine fetus.

    PubMed

    Chen, X; Threlkeld, S W; Cummings, E E; Juan, I; Makeyev, O; Besio, W G; Gaitanis, J; Banks, W A; Sadowska, G B; Stonestreet, B S

    2012-12-13

    The blood-brain barrier is a restrictive interface between the brain parenchyma and the intravascular compartment. Tight junctions contribute to the integrity of the blood-brain barrier. Hypoxic-ischemic damage to the blood-brain barrier could be an important component of fetal brain injury. We hypothesized that increases in blood-brain barrier permeability after ischemia depend upon the duration of reperfusion and that decreases in tight junction proteins are associated with the ischemia-related impairment in blood-brain barrier function in the fetus. Blood-brain barrier function was quantified with the blood-to-brain transfer constant (K(i)) and tight junction proteins by Western immunoblot in fetal sheep at 127 days of gestation without ischemia, and 4, 24, or 48 h after ischemia. The largest increase in K(i) (P<0.05) was 4 h after ischemia. Occludin and claudin-5 expressions decreased at 4 h, but returned toward control levels 24 and 48 h after ischemia. Zonula occludens-1 and -2 decreased after ischemia. Inverse correlations between K(i) and tight junction proteins suggest that the decreases in tight junction proteins contribute to impaired blood-brain barrier function after ischemia. We conclude that impaired blood-brain barrier function is an important component of hypoxic-ischemic brain injury in the fetus, and that increases in quantitatively measured barrier permeability (K(i)) change as a function of the duration of reperfusion after ischemia. The largest increase in permeability occurs 4 h after ischemia and blood-brain barrier function improves early after injury because the blood-brain barrier is less permeable 24 and 48 than 4 h after ischemia. Changes in the tight junction molecular composition are associated with increases in blood-brain barrier permeability after ischemia.

  17. Brain delivery of insulin boosted by intranasal coadministration with cell-penetrating peptides.

    PubMed

    Kamei, Noriyasu; Takeda-Morishita, Mariko

    2015-01-10

    Intranasal administration is considered as an alternative route to enable effective drug delivery to the central nervous system (CNS) by bypassing the blood-brain barrier. Several reports have proved that macromolecules can be transferred directly from the nasal cavity to the brain. However, strategies to enhance the delivery of macromolecules from the nasal cavity to CNS are needed because of their low delivery efficiencies via this route in general. We hypothesized that the delivery of biopharmaceuticals to the brain parenchyma can be facilitated by increasing the uptake of drugs by the nasal epithelium including supporting and neuronal cells to maximize the potentiality of the intranasal pathway. To test this hypothesis, the CNS-related model peptide insulin was intranasally coadministered with the cell-penetrating peptide (CPP) penetratin to mice. As a result, insulin coadministered with l- or d-penetratin reached the distal regions of the brain from the nasal cavity, including the cerebral cortex, cerebellum, and brain stem. In particular, d-penetratin could intranasally deliver insulin to the brain with a reduced risk of systemic insulin exposure. Thus, the results obtained in this study suggested that CPPs are potential tools for the brain delivery of peptide- and protein-based pharmaceuticals via intranasal administration.

  18. Convection enhanced delivery of cisplatin-loaded brain penetrating nanoparticles cures malignant glioma in rats.

    PubMed

    Zhang, Clark; Nance, Elizabeth A; Mastorakos, Panagiotis; Chisholm, Jane; Berry, Sneha; Eberhart, Charles; Tyler, Betty; Brem, Henry; Suk, Jung Soo; Hanes, Justin

    2017-03-07

    Glioblastoma multiforme (GBM) is highly invasive and uniformly fatal, with median survival<20months after diagnosis even with the most aggressive treatment that includes surgery, radiation, and systemic chemotherapy. Cisplatin is a particularly potent chemotherapeutic agent, but its use to treat GBM is limited by severe systemic toxicity and inefficient penetration of brain tumor tissue even when it is placed directly in the brain within standard delivery systems. We describe the development of cisplatin-loaded nanoparticles that are small enough (70nm in diameter) to move within the porous extracellular matrix between cells and that possess a dense polyethylene glycol (PEG) corona that prevents them from being trapped by adhesion as they move through the brain tumor parenchyma. As a result, these "brain penetrating nanoparticles" penetrate much deeper into brain tumor tissue compared to nanoparticles without a dense PEG corona following local administration by either manual injection or convection enhanced delivery. The nanoparticles also provide controlled release of cisplatin in effective concentrations to kill the tumor cells that they reach without causing toxicity-related deaths that were observed when cisplatin was infused into the brain without a delivery system. Median survival time of rats bearing orthotopic glioma was significantly enhanced when cisplatin was delivered in brain penetrating nanoparticles (median survival not reached; 80% long-term survivors) compared to cisplatin in conventional un-PEGylated particles (median survival=40days), cisplatin alone (median survival=12days) or saline-treated controls (median survival=28days).

  19. Synthesis and characterization of a PAMAM dendrimer nanocarrier functionalized by SRL peptide for targeted gene delivery to the brain.

    PubMed

    Zarebkohan, Amir; Najafi, Farhood; Moghimi, Hamid Reza; Hemmati, Mohammad; Deevband, Mohammad Reza; Kazemi, Bahram

    2015-10-12

    Blood-brain barrier inhibits most of drugs and genetic materials from reaching the brain. So, developing high efficiency carriers for gene and drug delivery to the brain, is the challenging area in pharmaceutical sciences. This investigation aimed to target DNA to brain using Serine-Arginine-Leucine (SRL) functionalized PAMAM dendrimers as a novel gene delivery system. The SRL peptide was linked on G4 PAMAM dendrimers using bifunctional PEG. DNA was then loaded in these functionalized nanoparticles and their physicochemical properties and cellular uptake/distribution evaluated by AFM, NMR, FTIR and fluorescence and confocal microscopy. Also, biodistribution and brain localization of nanoparticles were studied after IV injection of nanoparticles into rat tail. Unmodified nanoparticles were used as control in all evaluations. In vitro studies showed that SRL-modified nanoparticles have good transfection efficacy and low toxicity. Results also showed that SRL is a LRP ligand and SRL-modified nanoparticles internalized by clathrin/caveolin energy-dependent endocytosis to brain capillary endothelial cells. After intravenous administration, the SRL-modified nanoparticles were able to cross the blood-brain barrier and enter the brain parenchyma. Our result showed that, SRL-modified nanoparticles provide a safe and effective nanocarrier for brain gene delivery.

  20. In vivo magnetic resonance imaging investigating the development of experimental brain metastases due to triple negative breast cancer.

    PubMed

    Hamilton, Amanda M; Foster, Paula J

    2017-02-01

    Triple negative breast cancer (TNBC), when associated with poor outcome, is aggressive in nature with a high incidence of brain metastasis and the shortest median overall patient survival after brain metastasis development compared to all other breast cancer subtypes. As therapies that control primary cancer and extracranial metastatic sites improve, the incidence of brain metastases is increasing and the management of patients with breast cancer brain metastases continues to be a significant clinical challenge. Mouse models have been developed to permit in depth evaluation of breast cancer metastasis to the brain. In this study, we compare the efficiency and metastatic potential of two experimental mouse models of TNBC. Longitudinal MRI analysis and end point histology were used to quantify initial cell arrest as well as the number and volume of metastases that developed in mouse brain over time. We showed significant differences in MRI appearance, tumor progression and model efficiency between the syngeneic 4T1-BR5 model and the xenogeneic 231-BR model. Since TNBC does not respond to many standard breast cancer treatments and TNBC brain metastases lack effective targeted therapies, these preclinical TNBC models represent invaluable tools for the assessment of novel systemic therapeutic approaches. Further pursuits of therapeutics designed to bypass the blood tumor barrier and permit access to the brain parenchyma and metastatic cells within the brain will be paramount in the fight to control and treat lethal metastatic cancer.

  1. Circumventing the Blood-Brain Barrier with Autonomic Ganglion Transplants

    NASA Astrophysics Data System (ADS)

    Rosenstein, Jeffrey M.; Brightman, Milton W.

    1983-08-01

    Superior cervical ganglia, whose vessels are fenestrated and permeable to protein tracers such as horseradish peroxidase, were transplanted to undamaged surfaces in the fourth ventricle of rat pup brains. Horseradish peroxidase, infused systemically into the host, was exuded from the graft's vessels into the graft's extracellular stroma within 1 minute. At later times the glycoprotein reached the extracellular clefts of adjacent brain tissue, the vessels of which appeared to retain their impermeability. The blood-brain barrier to horseradish peroxide was thus bypassed where the extracellular compartments of graft and brain became confluent. The graft of autonomic ganglia can serve as a portal through which peptides, hormones, and immunoglobulins may likewise enter the brain.

  2. Factors predisposing to adjacent 2 and 3:1 disjunctions: study of 161 human reciprocal translocations.

    PubMed Central

    Jalbert, P; Sele, B

    1979-01-01

    Reciprocal translocations produce imbalances by three types of disjunction which are, in decreasing frequency, adjacent 1, 3:1, and adjacent 2. Adjacent 1 disjunction produces duplication deficiencies of inverse topography to those of adjacent 2. The imbalanced chromosome segments in one of these types are balanced in the other. The disjunction 3:1 produces pure trisomies and monosomies. The following situations predispose to adjacent 2 disjunction: translocations between the long arms of two acrocentric chromosomes or between one of these and that of a No 9 chromosome; centric segments, either short or carrying a heterochromatic zone (9qh); a balanced translocation in the mother. The factors predisposing to the disjunction adjacent 2 operate by selection, or directly on the meiotic configuration. Some of them (shortness of the interstitial segment, shortness of the short arms of translocation chromosomes) act in both these ways. Their influence is probably responsible for the repetitive and exclusive character of this disjunction. The conditions for the occurrence of the 3:1 disjunctions seem less strict than those for adjacent 2, although they should be of the same nature (involvement of acrocentrics or a chromosome 9 in the translocation, maternal origin). Images PMID:395305

  3. Distribution and characterization of doublecortin-expressing cells and fibers in the brain of the adult pigeon (Columba livia).

    PubMed

    Melleu, F F; Santos, T S; Lino-de-Oliveira, C; Marino-Neto, J

    2013-01-01

    Doublecortin (DCX) is a microtubule-associated protein essential for the migration of immature neurons in the developing and adult vertebrate brain. Herein, the distribution of DCX-immunoreactive (DCX-ir) cells in the prosencephalon of the adult pigeon (Columba livia) is described, in order to collect the evidence of their immature neural phenotype and to investigate their putative place of origin. Bipolar and multipolar DCX-ir cells were observed to be widespread throughout the parenchyma of the adult pigeon forebrain. Small, bipolar and fusiform DCX-ir cells were especially concentrated at the tips of the lateral walls of the lateral ventricles (VZ) and sparsely distributed in the remaining ependyma. Multipolar DCX-ir cells populated the pallial regions. None of these DCX-ir cells seemed to co-express NeuN or GFAP, suggesting that they were immature neurons. Two different migratory-like routes of DCX-ir cells from the VZ toward different targets in the parenchyma were putatively identified: (i) rostral migratory-like bundle; and (ii) lateral migratory-like bundle. In addition, pial surface bundles and intra-ependymal fascicles were also observed. Pigeons treated with 5-bromo-desoxyuridine (BrdU, 3 intraperitoneal injections of 100mg/kg 2h apart, sacrificed 2h after last injection) displayed BrdU-immunoreactive cells (BrdU-ir) in VZ and ependyma whereas the parenchyma was free of such cells. Despite the regional overlapping, there was no evidence of double-labeling between BrdU and DCX. Therefore, the VZ in the brain of adult pigeons seems to have rapidly dividing cells as putative progenitors of newborn neurons populating the forebrain. The distribution of the newborn neurons in the avian prosencephalon and their migration pathways appear to be larger than in mammals, suggesting that the morphological turnover of forebrain circuits is an important mechanism for brain plasticity in avian species during adulthood.

  4. Effects of Cadmium on the Glial Architecture in Lizard Brain

    PubMed Central

    Favorito, Rossana; Monaco, Antonio; Grimaldi, Maria C.; Ferrandino, Ida

    2017-01-01

    The glial cells are positioned to be the first cells of the brain parenchyma to face molecules crossing the blood-brain barrier with a relevant neuroprotective role from cytotoxic action of heavy metals on the nervous system. Cadmium is a highly toxic metal and its levels in the environment are increasing due to industrial activities. This element can pass the blood-brain barrier and have neurotoxic activity. For this reason we have studied the effects of cadmium on the glial architecture in the lizard Podarcis siculus, a significant bioindicator of chemical exposure due to its persistence in a variety of habitats. The study was performed on two groups of lizards. The first group of P. siculus was exposed to an acute treatment by a single i.p. injection (2 mg/kg-BW) of CdCl2 and sacrificed after 2, 7 and 16 days. The second one was used as control. The histology of the brain was studied by Hematoxylin/Eosin and Cresyl/Violet stains while the glial structures were analyzed by immunodetection of the glial fibrillary acidic protein (GFAP), the most widely accepted marker for astroglial cells. Evident morphological alterations of the brain were observed at 7 and 16 days from the injection, when we revealed also a decrease of the GFAP-immunopositive structures in particular in the rhombencephalic ventricle, telencephalon and optic tectum. These results show that in the lizards an acute exposure to cadmium provokes morphological cellular alterations in the brain but also a decrement of the expression of GFAP marker with possible consequent damage of glial cells functions. PMID:28348417

  5. Brain Imaging

    PubMed Central

    Racine, Eric; Bar-Ilan, Ofek; Illes, Judy

    2007-01-01

    Advances in neuroscience are increasingly intersecting with issues of ethical, legal, and social interest. This study is an analysis of press coverage of an advanced technology for brain imaging, functional magnetic resonance imaging, that has gained significant public visibility over the past ten years. Discussion of issues of scientific validity and interpretation dominated over ethical content in both the popular and specialized press. Coverage of research on higher order cognitive phenomena specifically attributed broad personal and societal meaning to neuroimages. The authors conclude that neuroscience provides an ideal model for exploring science communication and ethics in a multicultural context. PMID:17330151

  6. Exogenous arachidonic acid mediates permeability of human brain microvessel endothelial cells through prostaglandin E2 activation of EP3 and EP4 receptors.

    PubMed

    Dalvi, Siddhartha; Nguyen, Hieu H; On, Ngoc; Mitchell, Ryan W; Aukema, Harold M; Miller, Donald W; Hatch, Grant M

    2015-12-01

    The blood-brain barrier, formed by microvessel endothelial cells, is the restrictive barrier between the brain parenchyma and the circulating blood. Arachidonic acid (ARA; 5,8,11,14-cis-eicosatetraenoic acid) is a conditionally essential polyunsaturated fatty acid [20:4(n-6)] and is a major constituent of brain lipids. The current study examined the transport processes for ARA in confluent monolayers of human brain microvascular endothelial cells (HBMEC). Addition of radioactive ARA to the apical compartment of HBMEC cultured on Transwell(®) inserts resulted in rapid incorporation of radioactivity into the basolateral medium. Knock down of fatty acid transport proteins did not alter ARA passage into the basolateral medium as a result of the rapid generation of prostaglandin E2 (PGE2 ), an eicosanoid known to facilitate opening of the blood-brain barrier. Permeability following ARA or PGE2 exposure was confirmed by an increased movement of fluorescein-labeled dextran from apical to basolateral medium. ARA-mediated permeability was attenuated by specific cyclooxygenase-2 inhibitors. EP3 and EP4 receptor antagonists attenuated the ARA-mediated permeability of HBMEC. The results indicate that ARA increases permeability of HBMEC monolayers likely via increased production of PGE2 which acts upon EP3 and EP4 receptors to mediate permeability. These observations may explain the rapid influx of ARA into the brain previously observed upon plasma infusion with ARA. The blood-brain barrier, formed by microvessel endothelial cells, is a restrictive barrier between the brain parenchyma and the circulating blood. Radiolabeled arachidonic acid (ARA) movement across, and monolayer permeability in the presence of ARA, was examined in confluent monolayers of primary human brain microvessel endothelial cells (HBMECs) cultured on Transwell(®) plates. Incubation of HBMECs with ARA resulted in a rapid increase in HBMEC monolayer permeability. The mechanism was mediated, in part

  7. Exogenous fms-like tyrosine kinase 3 ligand overrides brain immune privilege and facilitates recognition of a neo-antigen without causing autoimmune neuropathology

    PubMed Central

    Larocque, Daniel; Sanderson, Nicholas S. R.; Bergeron, Josée; Curtin, James F.; Girton, Joe; Wibowo, Mia; Bondale, Niyati; Kroeger, Kurt M.; Yang, Jieping; Lacayo, Liliana M.; Reyes, Kevin C.; Farrokhi, Catherine; Pechnick, Robert N.; Castro, Maria G.; Lowenstein, Pedro R.

    2010-01-01

    Soluble antigens diffuse out of the brain and can thus stimulate a systemic immune response, whereas particulate antigens (from infectious agents or tumor cells) remain within brain tissue, thus failing to stimulate a systemic immune response. Immune privilege describes how the immune system responds to particulate antigens localized selectively within the brain parenchyma. We believe this immune privilege is caused by the absence of antigen presenting dendritic cells from the brain. We tested the prediction that expression of fms-like tyrosine kinase ligand 3 (Flt3L) in the brain will recruit dendritic cells and induce a systemic immune response against exogenous influenza hemagglutinin in BALB/c mice. Coexpression of Flt3L with HA in the brain parenchyma induced a robust systemic anti-HA immune response, and a small response against myelin basic protein and proteolipid protein epitopes. Depletion of CD4+CD25+ regulatory T cells (Tregs) enhanced both responses. To investigate the autoimmune impact of these immune responses, we characterized the neuropathological and behavioral consequences of intraparenchymal injections of Flt3L and HA in BALB/c and C57BL/6 mice. T cell infiltration in the forebrain was time and strain dependent, and increased in animals treated with Flt3L and depleted of Tregs; however, we failed to detect widespread defects in myelination throughout the forebrain or spinal cord. Results of behavioral tests were all normal. These results demonstrate that Flt3L overcomes the brain's immune privilege, and supports the clinical development of Flt3L as an adjuvant to stimulate clinically effective immune responses against brain neo-antigens, for example, those associated with brain tumors. PMID:20660723

  8. Enalapril attenuates ischaemic brain oedema and protects the blood-brain barrier in rats via an anti-oxidant action.

    PubMed

    Panahpour, Hamdollah; Dehghani, Gholam Abbas; Bohlooli, Shahab

    2014-03-01

    1. In the present study, we investigated the effects of postischaemic angiotensin-converting enzyme (ACE) inhibition with enalapril on vasogenic oedema formation and blood-brain barrier (BBB) integrity following transient focal cerebral ischaemia in rats. 2. Cerebral ischaemia was induced by 60 min occlusion of the right middle cerebral artery, followed by 24 h reperfusion. Vehicle and a non-hypotensive dose of enalapril (0.03 mg/kg) were administered at the beginning of the reperfusion period. A neurological deficit score (NDS) was determined for all rats at the end of the reperfusion period. Then, brain oedema formation was investigated using the wet-dry weight method and BBB permeability was evaluated on the basis of extravasation of Evans blue (EB) dye. In addition, oxidative stress was assessed by measuring reduced glutathione (GSH) and malondialdehyde (MDA) in brain homogenates. 3. Inhibition of ACE by enalapril significantly reduced NDS and decreased brain oedema formation (P < 0.05 for both). Disruption of the BBB following ischaemia resulted in considerable leakage of EB dye into the brain parenchyma of the ipsilateral hemispheres of vehicle-treated rats. Enalapril significantly (P < 0.05) decreased EB extravasation into the lesioned hemisphere. Enalapril also augmented anti-oxidant activity in ischaemic brain tissue by increasing GSH concentrations and significantly (P < 0.05) attenuating the increased MDA levels in response to ischaemia. 4. In conclusion, inhibition of ACE with a non-hypotensive dose of enalapril may protect BBB function and attenuate oedema formation via anti-oxidant actions.

  9. Blood-brain barrier permeability of ginkgolide: Comparison of the behavior of PET probes 7α-[(18)F]fluoro- and 10-O-p-[(11)C]methylbenzyl ginkgolide B in monkey and rat brains.

    PubMed

    Doi, Hisashi; Sato, Kengo; Shindou, Hideo; Sumi, Kengo; Koyama, Hiroko; Hosoya, Takamitsu; Watanabe, Yasuyoshi; Ishii, Satoshi; Tsukada, Hideo; Nakanishi, Koji; Suzuki, Masaaki

    2016-11-01

    The blood-brain barrier permeability of ginkgolide B was examined using positron emission tomography (PET) probes of a (18)F-incorporated ginkgolide B ([(18)F]-2) and a (11)C-incorporated methylbenzyl-substituted ginkgolide B ([(11)C]-3). PET studies in monkeys showed low uptake of [(18)F]-2 into the brain, but small amounts of [(11)C]-3 were accumulated in the parenchyma. Furthermore, when cyclosporine A was preadministered to rats, the accumulation of [(18)F]-2 in the rat brain did not significantly change, however, the accumulation of [(11)C]-3 was five times higher than that in the control rat. These results provide effective approaches for investigating the drug potential of ginkgolides.

  10. Dexamethasone effects on (/sup 125/I)albumin distribution in experimental RG-2 gliomas and adjacent brain

    SciTech Connect

    Nakagawa, H.; Groothuis, D.R.; Owens, E.S.; Fenstermacher, J.D.; Patlak, C.S.; Blasberg, R.G.

    1987-12-01

    A total of 72 RG-2 transplanted gliomas were studied in 58 rats at three time points (1, 30, 240 min) after intravenous injection of (/sup 125/I)radioiodinated serum albumin ((/sup 125/I)RISA). The animals were divided into two groups: a control group that received no treatment and a second group that was treated with five doses of 1.5 mg/kg of dexamethasone over 2.5 days. Local tissue concentrations of (/sup 125/I)RISA were measured with quantitative autoradiography based on morphological features of the tumors and used to calculate the tissue distribution space. Two models were used to analyze the data. A two compartment model yielded estimates of local blood-to-tissue influx constants (K1), lower limit extracellular volumes (Ve), and plasma vascular volumes (Vp) in different tumor regions. Treatment with dexamethasone consistently reduced the RISA distribution space in the RG-2 tumors; the reduction in Ve was statistically significant in almost all tumor regions: whole tumor Ve (mean +/- SE) was reduced from 0.14 +/- 0.02 ml g-1 in control animals to 0.08 +/- 0.01 ml g-1 in dexamethasone treated animals. K1 and Vp were also decreased in all tumor regions after treatment with dexamethasone (whole tumor K1 decreased from 2.36 +/- 0.89 to 0.83 +/- 0.29 microliter g-1 min-1 and Vp decreased slightly from 0.016 +/- 0.013 to 0.010 +/- 0.005 ml g-1 after dexamethasone treatment), but these changes were not statistically significant. A comparison of the tumor influx constants in control animals and the aqueous diffusion constants of two different size molecules (RISA and aminoisobutyric acid) suggests that the ''pores'' across RG-2 capillaries are large and may not restrict the free diffusion of RISA (estimated minimum pore diameter greater than 36 nm) and that the total pore area is approximately 6.2 X 10(-5) cm2 g-1 in RG-2 tumor tissue.

  11. Brain tissue pressure measurements in perinatal and adult rabbits.

    PubMed

    Hornig, G W; Lorenzo, A V; Zavala, L M; Welch, K

    1987-12-01

    Brain tissue pressure (BTP) in pre- and post-natal anesthetized rabbits, held in a stereotactic head holder, was measured with a fluid filled 23 gauge open-ended cannula connected distally to a pressure transducer. By advancing the cannula step wise through a hole in the cranium it was possible to sequentially measure pressure from the cranial subarachnoid space, cortex, ventricle and basal ganglia. Separate cannulas and transducers were used to measure CSFP from the cisterna magna and arterial and/or venous pressure. Pressure recordings obtained when the tip of the BTP cannula was located in the cranial subarachnoid space or ventricle exhibited respiratory and blood pressure pulsations equivalent to and in phase with CSF pulsations recorded from the cisterna magna. When the tip was advanced into brain parenchymal sites such pulsations were suppressed or non-detectable unless communication with a CSF compartment had been established inadvertently. Although CSF pressures in the three spinal fluid compartments were equivalent, in most animals BTP was higher than CSFP. However, after momentary venting of the system BTP equilibrated at a pressure below that of CSFP. We speculate that venting of the low compliance system (1.20 x 10(-5) ml/mmHg) relieves the isometric pressure build-up due to insertion of the cannula into brain parenchyma. Under these conditions, and at all ages examined, BTP in the rabbit is consistently lower than CSFP and, as with CSFP, it increases as the animal matures.

  12. The proteome of mouse brain microvessel membranes and basal lamina

    PubMed Central

    Chun, Hyun Bae; Scott, Michael; Niessen, Sherry; Hoover, Heather; Baird, Andrew; Yates, John; Torbett, Bruce E; Eliceiri, Brian P

    2011-01-01

    The blood–brain barrier (BBB) is a multicellular vascular structure separating blood from the brain parenchyma that is composed of endothelial cells with tight intercellular junctions, surrounded by a basal lamina, astrocytes, and pericytes. Previous studies have generated detailed databases of the microvessel transcriptome; however, less information is available on the BBB at the protein level. In this study, we specifically focused on characterization of the membrane fraction of cells within the BBB to generate a more complete understanding of membrane transporters, tight junction proteins, and associated extracellular matrix proteins that are functional hallmarks of the BBB. We used Multidimensional Protein Identification Technology to identify a total of 1,143 proteins in mouse brain microvessels, of which 53% were determined to be membrane associated. Analyses of specific classes of BBB-associated proteins in the context of recent transcriptome reports provide a unique database to assess the relative contribution of genes at the level of both RNA and protein in the maintenance of normal BBB integrity. PMID:21792245

  13. Fortress brain.

    PubMed

    Royall, Donald R

    2013-02-01

    Neurodegenerative diseases are associated with neuronal inclusions, comprised of protein aggregates. In Alzheimer's Disease (AD) and Lewy Body Disease (LBD) such lesions are distributed in a hierarchical retrograde transynaptic spatial pattern. This implies a retrograde transynaptic temporal propagation as well. There can be few explanations for this other than infectious agents (prions and viruses). This suggests that AD and LBD (at least) may have infectious origins. Transynaptic infiltration of the CNS along cranial nerve or other major projections, by one or more infectious agents has important implications. The clinical syndrome and natural history of each neurodegenerative disorder will reflect its portal of entry. There may be a different neurodegenerative syndrome for each cranial nerve or other portal of entry, and not all may manifest as "dementia". Each syndrome may be associated with more than one pathological lesion. Each pathology may be associated with several clinical syndromes. Host-parasite interactions are species specific. This may explain the rarity of AD-like pathology in most other older mammals. Over evolutionary timescales, the human brain should be adapted to predation by neurotropic agents. Viewed from this perspective, the prion-like pro-inflammatory and pro-apoptotic properties of β-amyloid and other proteins may be adaptive, and anti-microbial. Reductions in synaptic density may slow the progress of invading pathogens, while perineuronal nets and other structures may guard the gates. This suggests a defense in depth of a structure, the brain, that is inherently vulnerable to invasion along its neural networks.

  14. 33 CFR 334.70 - Buzzards Bay, and adjacent waters, Mass.; danger zones for naval operations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... REGULATIONS § 334.70 Buzzards Bay, and adjacent waters, Mass.; danger zones for naval operations. (a) Atlantic Ocean in vicinity of No Mans Land—(1) The area. The waters surrounding No Mans Land within an...

  15. Numerical Simulation of Salinity and Dissolved Oxygen at Perdido Bay and Adjacent Coastal Ocean

    EPA Science Inventory

    Environmental Fluid Dynamic Code (EFDC), a numerical estuarine and coastal ocean circulation hydrodynamic model, was used to simulate the distribution of the salinity, temperature, nutrients and dissolved oxygen (DO) in Perdido Bay and adjacent Gulf of Mexico. External forcing fa...

  16. 7. WALKWAY/ENTRANCE TO ADMINSITRATIVE SITE ADJACENT TO ENTRANCE ROAD AND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. WALKWAY/ENTRANCE TO ADMINSITRATIVE SITE ADJACENT TO ENTRANCE ROAD AND INTERNAL POLICE POST, LOOKING SOUTHEAST - Manzanar War Relocation Center, Owens Valley off U.S. Highway 395, 6 miles South of Independence, Independence, Inyo County, CA

  17. Divergent parasite faunas in adjacent populations of West Greenland caribou: suggested natural and anthropogenic influences

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Gastrointestinal parasite diversity was characterized for two adjacent populations of west Greenland caribou (Rangifer tarandus groenlandicus) through examinations of abomasa and small intestines of adult and subadult females collected during late winter. Three trichostrongyline (Trichostrongylina: ...

  18. 5. Former P&LE tracks (now CSXT) adjacent to trestle towards ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. Former P&LE tracks (now CSXT) adjacent to trestle towards west. - Monongahela Connecting Railroad Company, Y Trestle, South side of Monongahela River between Thirty-fourth & Twenty-ninth Streets, Pittsburgh, Allegheny County, PA

  19. New neurons clear the path of astrocytic processes for their rapid migration in the adult brain.

    PubMed

    Kaneko, Naoko; Marín, Oscar; Koike, Masato; Hirota, Yuki; Uchiyama, Yasuo; Wu, Jane Y; Lu, Qiang; Tessier-Lavigne, Marc; Alvarez-Buylla, Arturo; Okano, Hideyuki; Rubenstein, John L R; Sawamoto, Kazunobu

    2010-07-29

    In the long-range neuronal migration of adult mammals, young neurons travel from the subventricular zone to the olfactory bulb, a long journey (millimeters to centimeters, depending on the species). How can these neurons migrate through the dense meshwork of neuronal and glial processes of the adult brain parenchyma? Previous studies indicate that young neurons achieve this by migrating in chains through astrocytic tunnels. Here, we report that young migrating neurons actively control the formation and maintenance of their own migration route. New neurons secrete the diffusible protein Slit1, whose receptor, Robo, is expressed on astrocytes. We show that the Slit-Robo pathway is required for morphologic and organizational changes in astrocytes that result in the formation and maintenance of the astrocytic tunnels. Through this neuron-glia interaction, the new neurons regulate the formation of the astrocytic meshwork that is needed to enable their rapid and directional migration in adult brain.

  20. Viral nanoparticles associate with regions of inflammation and blood brain barrier disruption during CNS infection

    PubMed Central

    Shriver, Leah P.; Koudelka, Kristopher J.; Manchester, Marianne

    2010-01-01

    Targeted treatment of inflammatory diseases of the central nervous system (CNS) remains problematic due to the complex pathogenesis of these disorders and difficulty in drug delivery. The plant virus, cow pea mosaic virus (CPMV), has recently been explored as a nanoparticle delivery system for therapeutics targeting a number of diseases including cancer and neurodegeneration. To understand the biodistribution of CPMV in the CNS, we examined CPMV uptake during infection of mice with neurotropic mouse hepatitis virus (MHV). CPMV localized mainly to the CNS endothelium in areas that contained an intact blood brain barrier. However, in inflammatory lesions containing macrophage/microglial cell infiltration and IgG, CPMV could be detected in the brain parenchyma. Furthermore, CPMV showed rapid internalization in an in vitro model of the BBB. These results suggest that CPMV particles could be used to a vehicle to deliver therapeutics to the damaged CNS during neurodegenerative and infectious diseases of the CNS. PMID:19394707

  1. Minimally invasive treatment for esthetic enhancement of white spot lesion in adjacent tooth

    PubMed Central

    Lee, Ji-Hye; Kim, Dae-Gon; Park, Chan-Jin

    2013-01-01

    This article describes the treatment provided to a patient with the maxillary anterior teeth exhibiting severe secondary caries beneath the previous restoration and a white spot lesion on the adjacent incisor. Two implants were placed after extraction of hopeless teeth with the guided bone regeneration technique. A white spot lesion of the adjacent incisor was treated with minimally invasive treatment. This clinical report describes the multidisciplinary treatment for the white spot lesion and esthetic restoration of missing anterior teeth. PMID:24049579

  2. Novel functionalization strategies of polymeric nanoparticles as carriers for brain medications.

    PubMed

    Portioli, Corinne; Bovi, Michele; Benati, Donatella; Donini, Marta; Perduca, Massimiliano; Romeo, Alessandro; Dusi, Stefano; Monaco, Hugo L; Bentivoglio, Marina

    2017-03-01

    For targeted brain delivery, nanoparticles (NPs) should bypass the blood-brain barrier (BBB). Novel functionalization strategies, based on low-density lipoprotein receptor (LDLR) binding domain, have been here tested to increase the brain targeting efficacy of poly d,l-lactic-co-glycolic acid (PLGA) NPs, biodegradable and suited for biomedical applications. Custom-made PLGA NPs were functionalized with an apolipoprotein E modified peptide (pep-apoE) responsible for LDLR binding, or with lipocalin-type prostaglandin-d-synthase (L-PGDS), highly expressed in the brain. At the comparison of pep-apoE and L-PGDS sequences, a highly homologs region was here identified, indicating that also L-PGDS could bind LDLR. Non-functionalized and functionalized NPs did not affect the viability of cultured human dendritic cells, protagonists of the immune response, and did not activate them to a proinflammatory profile. At 2 h after intravenous injection in mice, functionalized, but not the non-functionalized ones, fluorescent-tagged NPs were observed in the cerebral cortex parenchyma. The NPs were mostly internalized by neurons and microglia; glial cells showed a weak activation. The findings indicate that the tested functionalization strategies do not elicit adverse immune responses and that the peptidic moieties enable BBB traversal of the NPs, thus providing potential brain drug carriers. These could be especially effective for brain diseases in which LDLR is involved. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 847-858, 2017.

  3. Expression of the Astrocyte Water Channel Aquaporin-4 in the Mouse Brain.

    PubMed

    Hubbard, Jacqueline A; Hsu, Mike S; Seldin, Marcus M; Binder, Devin K

    2015-01-01

    Aquaporin-4 (AQP4) is a bidirectional water channel that is found on astrocytes throughout the central nervous system. Expression is particularly high around areas in contact with cerebrospinal fluid, suggesting that AQP4 plays a role in fluid exchange between the cerebrospinal fluid compartments and the brain. Despite its significant role in the brain, the overall spatial and region-specific distribution of AQP4 has yet to be fully characterized. In this study, we used Western blotting and immunohistochemical techniques to characterize AQP4 expression and localization throughout the mouse brain. We observed AQP4 expression throughout the forebrain, subcortical areas, and brainstem. AQP4 protein levels were highest in the cerebellum with lower expression in the cortex and hippocampus. We found that AQP4 immunoreactivity was profuse on glial cells bordering ventricles, blood vessels, and subarachnoid space. Throughout the brain, AQP4 was expressed on astrocytic end-feet surrounding blood vessels but was also heterogeneously expressed in brain tissue parenchyma and neuropil, often with striking laminar specificity. In the cerebellum, we showed that AQP4 colocalized with the proteoglycan brevican, which is synthesized by and expressed on cerebellar astrocytes. Despite the high abundance of AQP4 in the cerebellum, its functional significance has yet to be investigated. Given the known role of AQP4 in synaptic plasticity in the hippocampus, the widespread and region-specific expression pattern of AQP4 suggests involvement not only in fluid balance and ion homeostasis but also local synaptic plasticity and function in distinct brain circuits.

  4. Evaluation of brain toxicity following near infrared light exposure after indocyanine green dye injection.

    PubMed

    Keller, Emanuela; Ishihara, Hideyuki; Nadler, Andreas; Niederer, Peter; Seifert, Burkhardt; Yonekawa, Yasuhiro; Frei, Karl

    2002-05-30

    Indocyanine green (ICG) has excellent safety records and is widely used in medical diagnosis. Recently, a new method has been developed to estimate cerebral blood flow (CBF) using ICG in combination with near-infrared spectroscopy (NIRS). The new technique may be of wide clinical interest, as it is noninvasive and easy to perform at the bedside in stroke patients. Additionally, ICG with the use of specific wavelength lasers is documented to be effective in photodynamic therapy (PDT). Under normal conditions ICG does not cross the intact blood brain barrier (BBB). However, in patients with brain injuries where the BBB may be disturbed, ICG could accumulate in brain parenchyma and in combination with NIR-light exposure, phototoxicity could occur. The aim of the present study was to examine the possible toxicity of ICG in combination with NIRS in a specific setting for CBF measurements. In five rats with mannitol induced BBB breakdown no traces of ICG were found during spectrophotometric analysis of the brain cell suspensions. In ten rats with disrupted BBB there were no significant increases of brain temperature or histological signs of brain damage following 1 h NIR-light exposure after ICG injection. The existing literature concerning the application of ICG in combination with NIR light is reviewed.

  5. Targeted delivery of antibody-based therapeutic and imaging agents to CNS tumors: Crossing the blood-brain-barrier divide

    PubMed Central

    Chacko, Ann-Marie; Li, Chunsheng; Pryma, Daniel A.; Brem, Steven; Coukos, George; Muzykantov, Vladimir R.

    2014-01-01

    Introduction Brain tumors are inherently difficult to treat in large part due to the cellular blood-brain barriers (BBB) that limit the delivery of therapeutics to the tumor tissue from the systemic circulation. Virtually no large-molecules, including antibody-based proteins, can penetrate the BBB. With antibodies fast becoming attractive ligands for highly specific molecular targeting to tumor antigens, a variety of methods are being investigated to enhance the access of these agents to intracranial tumors for imaging or therapeutic applications. Areas covered This review describes the characteristics of the BBB and the vasculature in brain tumors, described as the blood-brain tumor barrier (BBTB). Antibodies targeted to molecular markers of CNS tumors will be highlighted, and current strategies for enhancing the delivery of antibodies across these cellular barriers into the brain parenchyma to the tumor will be discussed. Non-invasive imaging approaches to assess BBB/BBTB permeability and/or antibody targeting will be presented as a means of guiding the optimal delivery of targeted agents to brain tumors. Expert Opinion Pre-clinical and clinical studies highlight the potential of several approaches in increasing brain tumor delivery across the blood-brain barrier divide. However, each carries its own risks and challenges. There is tremendous potential in using neuroimaging strategies to assist in understanding and defining the challenges to translating and optimizing molecularly-targeted antibody delivery to CNS tumors to improve clinical outcomes. PMID:23751126

  6. The psychopath magnetized: insights from brain imaging

    PubMed Central

    Anderson, Nathaniel E.; Kiehl, Kent A.

    2014-01-01

    Psychopaths commit a disproportionate amount of violent crime, and this places a substantial economic and emotional burden on society. Elucidation of the neural correlates of psychopathy may lead to improved management and treatment of the condition. Although some methodological issues remain, the neuroimaging literature is generally converging on a set of brain regions and circuits that are consistently implicated in the condition: the orbitofrontal cortex, amygdala, and the anterior and posterior cingulate and adjacent (para)limbic structures. We discuss these findings in the context of extant theories of psychopathy and highlight the potential legal and policy implications of this body of work. PMID:22177031

  7. Histological Architecture Underlying Brain-Immune Cell-Cell Interactions and the Cerebral Response to Systemic Inflammation.

    PubMed

    Shimada, Atsuyoshi; Hasegawa-Ishii, Sanae

    2017-01-01

    Although the brain is now known to actively interact with the immune system under non-inflammatory conditions, the site of cell-cell interactions between brain parenchymal cells and immune cells has been an open question until recently. Studies by our and other groups have indicated that brain structures such as the leptomeninges, choroid plexus stroma and epithelium, attachments of choroid plexus, vascular endothelial cells, cells of the perivascular space, circumventricular organs, and astrocytic endfeet construct the histological architecture that provides a location for intercellular interactions between bone marrow-derived myeloid lineage cells and brain parenchymal cells under non-inflammatory conditions. This architecture also functions as the interface between the brain and the immune system, through which systemic inflammation-induced molecular events can be relayed to the brain parenchyma at early stages of systemic inflammation during which the blood-brain barrier is relatively preserved. Although brain microglia are well known to be activated by systemic inflammation, the mechanism by which systemic inflammatory challenge and microglial activation are connected has not been well documented. Perturbed brain-immune interaction underlies a wide variety of neurological and psychiatric disorders including ischemic brain injury, status epilepticus, repeated social defeat, and neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease. Proinflammatory status associated with cytokine imbalance is involved in autism spectrum disorders, schizophrenia, and depression. In this article, we propose a mechanism connecting systemic inflammation, brain-immune interface cells, and brain parenchymal cells and discuss the relevance of basic studies of the mechanism to neurological disorders with a special emphasis on sepsis-associated encephalopathy and preterm brain injury.

  8. Brain aneurysm repair - discharge

    MedlinePlus

    ... gov/pubmed/22556195 . Szeder V, Tateshima S, Duckwiler GR. Intracranial aneurysms and subarachnoid hemorrhage. In: Daroff RB, Jankovic J, ... chap 67. Read More Aneurysm in the brain Brain aneurysm repair Brain surgery Recovering after stroke Seizures Smoking - ...

  9. Traumatic Brain Injury

    MedlinePlus

    Traumatic brain injury (TBI) happens when a bump, blow, jolt, or other head injury causes damage to the brain. Every year, millions of people in the U.S. suffer brain injuries. More than half are bad enough that ...

  10. Pediatric Brain Tumor Foundation

    MedlinePlus

    ... you insights into your child's treatment. LEARN MORE Brain tumors and their treatment can be deadly so ... Pediatric Brain Tumor Foundation Board Read more >> Pediatric Brain Tumor Foundation 302 Ridgefield Court, Asheville, NC 28806 ...

  11. Brain-based Learning.

    ERIC Educational Resources Information Center

    Weiss, Ruth Palombo

    2000-01-01

    Discusses brain research and how new imaging technologies allow scientists to explore how human brains process memory, emotion, attention, patterning, motivation, and context. Explains how brain research is being used to revise learning theories. (JOW)

  12. Special Report: Brain Chemistry.

    ERIC Educational Resources Information Center

    Krassner, Michael B.

    1983-01-01

    Chemical actions in the brain result in cognitive, emotional, neuroendocrine, neuromuscular, and/or neurocirculatory effects. Developments in understanding brain chemistry are discussed, considering among others, neurotransmitter chemistry, neuropeptides, drugs and the brain, antidepressants, and actions of minor tranquilizers. (JN)

  13. Mild Traumatic Brain Injury

    MedlinePlus

    ... Questions Glossary Contact Us Visitor Feedback mild Traumatic Brain Injury mild Traumatic Brain Injury VIDEO STORIES What is TBI Measuring Severity ... most common deployment injuries is a mild Traumatic Brain Injury (TBI). A mild TBI is an injury ...

  14. Traumatic Brain Injury

    MedlinePlus

    ... brain to bump against the inside of your skull. Common TBIs, such as concussions, can happen during ... an object, like a bullet or piece of skull, pierces your brain. Symptoms of a traumatic brain ...

  15. That's Using Your Brain!

    ERIC Educational Resources Information Center

    Visser, Dana R.

    1996-01-01

    Discusses new adult learning theories, including those of Roger Sperry (left brain/right brain), Paul McLean (triune brain), and Howard Gardner (multiple intelligences). Relates adult learning theory to training. (JOW)

  16. American Brain Tumor Association

    MedlinePlus

    ... Molecule Read More ABTA News April 6, 2017 Chicago-Based American Brain Tumor Association’s Breakthrough for Brain ... Association 8550 W. Bryn Mawr Ave. Ste 550 Chicago, IL 60631 © 2014 American Brain Tumor Association Phone: ...

  17. Testing wetland axioms at a watershed scale: Case studies of the aggregate hydrologic effects of non-adjacent wetlands

    EPA Science Inventory

    Wetlands not adjacent to streams (i.e. “non-adjacent wetlands”) are hypothesized to affect downgradient hydrology in a number of ways. Non-adjacent wetlands may, for example, attenuate peak flows, serve as focal points for groundwater recharge, and decrease streamflow...

  18. Nourish Your Brain

    MedlinePlus

    ... Tags: brain, brain-healthy, cognitive decline, dementia, diet, exercise, health, lifestyle Family Health, Prevention and Wellness, Seniors, Staying Healthy December 2010 Copyright © American Academy of ...

  19. Optically enhanced blood-brain-barrier crossing of plasmonic-active nanoparticles in preclinical brain tumor animal models

    NASA Astrophysics Data System (ADS)

    Yuan, Hsiangkuo; Wilson, Christy M.; Li, Shuqin; Fales, Andrew M.; Liu, Yang; Grant, Gerald; Vo-Dinh, Tuan

    2014-02-01

    Nanotechnology provides tremendous biomedical opportunities for cancer diagnosis, imaging, and therapy. In contrast to conventional chemotherapeutic agents where their actual target delivery cannot be easily imaged, integrating imaging and therapeutic properties into one platform facilitates the understanding of pharmacokinetic profiles, and enables monitoring of the therapeutic process in each individual. Such a concept dubbed "theranostics" potentiates translational research and improves precision medicine. One particular challenging application of theranostics involves imaging and controlled delivery of nanoplatforms across blood-brain-barrier (BBB) into brain tissues. Typically, the BBB hinders paracellular flux of drug molecules into brain parenchyma. BBB disrupting agents (e.g. mannitol, focused ultrasound), however, suffer from poor spatial confinement. It has been a challenge to design a nanoplatform not only acts as a contrast agent but also improves the BBB permeation. In this study, we demonstrated the feasibility of plasmonic gold nanoparticles as both high-resolution optical contrast agent and focalized tumor BBB permeation-inducing agent. We specifically examined the microscopic distribution of nanoparticles in tumor brain animal models. We observed that most nanoparticles accumulated at the tumor periphery or perivascular spaces. Nanoparticles were present in both endothelial cells and interstitial matrices. This study also demonstrated a novel photothermal-induced BBB permeation. Fine-tuning the irradiating energy induced gentle disruption of the vascular integrity, causing short-term extravasation of nanomaterials but without hemorrhage. We conclude that our gold nanoparticles are a powerful biocompatible contrast agent capable of inducing focal BBB permeation, and therefore envision a strong potential of plasmonic gold nanoparticle in future brain tumor imaging and therapy.

  20. Influence of time to achieve substrate distribution equilibrium between brain tissue and blood on quantitation of the blood-brain barrier P-glycoprotein effect.

    PubMed

    Padowski, Jeannie M; Pollack, Gary M

    2011-12-02

    Active efflux transport processes at the blood-brain barrier (BBB), such as P-glycoprotein (P-gp)-mediated efflux, can limit brain uptake of therapeutics. Accurate determination of the consequent impact on brain uptake is assumed to require sampling post-attainment of brain-to-blood distribution equilibrium. Because this approach is not always feasible, understanding the relationship between apparent degree of efflux (e.g., calculated BBB P-gp effect) and the fraction of time remaining until distribution equilibrium is achieved (FTDE) would be advantageous. This study employed simulation strategies to explore this relationship in the simplest relevant system (absence of protein binding, saturable uptake, or metabolism at the BBB). Concentration-time profiles were simulated with a 4-compartment system (blood, peripheral tissues, BBB endothelium and brain parenchyma). A unidirectional endothelium-to-blood rate constant, PS(e), represented P-gp-mediated efflux. A parameter space was selected to simulate an 18-fold P-gp effect, (K(p,brain) at distribution equilibrium in the absence [K(p,brain)=82] vs. presence [K(p,brain)=4.5] of P-gp-mediated flux), as observed for paclitaxel in P-gp-deficient vs. P-gp-competent mice. Hypothetical compounds with different P-gp effects, peripheral compartment distribution kinetics, or times to achieve distribution equilibrium were simulated by perturbing the values of relevant model parameters. P-gp effects calculated prior to attainment of distribution equilibrium may be substantially erroneous. However, reasonably accurate estimates can be obtained relatively early in the net distributional phase (under 20% error at FTDE>0.36 or 0.11 for bolus or infusion administration, respectively). Potential errors associated with non-equilibrium calculations are dependent on both P-gp-mediated and P-gp-independent components of flux across the BBB.