Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Anatomy (17)
- Curriculum and Instruction (17)
- Education (17)
- Educational Assessment, Evaluation, and Research (17)
- Neoplasms (17)
-
- Nervous System (17)
- Medical Specialties (11)
- Neurology (10)
- Health Services Research (2)
- Life Sciences (2)
- Pathological Conditions, Signs and Symptoms (2)
- Physical Sciences and Mathematics (2)
- Public Health (2)
- Translational Medical Research (2)
- Biochemistry (1)
- Biochemistry, Biophysics, and Structural Biology (1)
- Biophysics (1)
- Biostatistics (1)
- Cardiology (1)
- Cardiovascular Diseases (1)
- Chemicals and Drugs (1)
- Chemistry (1)
- Computational Biology (1)
- Epidemiology (1)
- Genetics and Genomics (1)
- Geriatrics (1)
- Inorganic Chemicals (1)
- Keyword
-
- Nervous System (10)
- Neoplasms (5)
- Gap junctions (4)
- Nervous System Disease (4)
- Brain (3)
-
- Male (3)
- Animals (2)
- Brain Ischemia (2)
- Cerebrovascular Circulation (2)
- Connexin (2)
- Connexin43 (2)
- Connexins (2)
- Gap junction (2)
- Gene therapy (2)
- Leukoaraiosis (2)
- Neurons (2)
- Rats (2)
- Rats, Sprague-Dawley (2)
- *Behavior, Animal (1)
- *Magnetic Resonance Imaging (1)
- *Sex Characteristics (1)
- 0-2A progenitor (1)
- Adhesion (1)
- Aged (1)
- Aged, 80 and over (1)
- Alzheimer’s disease (1)
- Amyotrophic Lateral Sclerosis (1)
- Antipsychotic (1)
- Artery (1)
- Assembly (1)
- Publication Year
Articles 1 - 30 of 31
Full-Text Articles in Nervous System Diseases
Kyphotic Progression After Thoracolumbar Burst Fractures Treated Conservatively, With Mis, Or Via Open Approach, Mark Rivkin, Howard Eisenbrock
Kyphotic Progression After Thoracolumbar Burst Fractures Treated Conservatively, With Mis, Or Via Open Approach, Mark Rivkin, Howard Eisenbrock
Mark Rivkin
Management of thoracolumbar burst fractures (AO A3) without neurological deficit is subject to debate in the literature. While TLICS provides guidance for injuries necessitating intervention, it makes little mention of best surgical approaches. Furthermore, intact patients with suspected posterior ligamentous complex injury (TLICS 4) compose an additional level of management uncertainty. Present study examined outcomes for TL burst fractures in neurologically intact patients with suspected disruption of the PLC treated with bracing, MIS, or open fixation and fusion.
Leukoaraiosis And Sex Predict The Hyperacute Ischemic Core Volume, Nils Henninger, Eugene Lin, Diogo Haussen, Laura Lehman, Deepak Takhtani, Magdy Selim, Majaz Moonis
Leukoaraiosis And Sex Predict The Hyperacute Ischemic Core Volume, Nils Henninger, Eugene Lin, Diogo Haussen, Laura Lehman, Deepak Takhtani, Magdy Selim, Majaz Moonis
Nils Henninger
BACKGROUND AND PURPOSE: Leukoaraiosis (LA) and male sex have been associated with decreased cerebrovascular reactivity, which potentially adversely affects tissue viability in acute stroke. Therefore, we aimed to elucidate the contribution of LA-severity and sex to the extent of the hyperacute ischemic core volume after intracranial large artery occlusion. METHODS: We analyzed data from 87 patients with acute intracranial large artery occlusion who had acute multimodal computed tomography-imaging. LA-severity was assessed using the van Swieten scale on noncontrast computed tomography. Computed tomography perfusion data were analyzed using automatic calculation of the mean transit time and hyperacute cerebral blood volume defects. …
Severity Of Pre-Existing Cerebral Small Vessel Disease Is Associated With Outcome After Traumatic Brain Injury, Nils Heninger, Saef Izzy, Raphael Carandang, Wiley Hall, Susanne Muehlschlegel
Severity Of Pre-Existing Cerebral Small Vessel Disease Is Associated With Outcome After Traumatic Brain Injury, Nils Heninger, Saef Izzy, Raphael Carandang, Wiley Hall, Susanne Muehlschlegel
Nils Henninger
Background and purpose: It is now well accepted that traumatic white matter injury constitutes a critical determinant of post-traumatic functional impairment. However, the contribution of pre-existing white matter rarefaction on outcome following traumatic brain injury (TBI) is unknown. Hence, we sought to determine whether the burden of pre-existing cerebral small vessel disease related white matter rarefaction (leukoaraiosis) is independently associated with outcome after TBI. Methods: We retrospectively analyzed consecutive, prospectively enrolled patients of ≥50 years (n=136) that were admitted to a single neurological-trauma intensive care unit. Supratentorial white matter hypoattenuation on head CT was graded on a 5-point scale (range …
Traumatic Brain Injury: Translation From Animal Models And Genetics To Improving Outcomes, Susanne Muehlschlegel, Nils Henninger, Raphael Carandang, Constance Moore
Traumatic Brain Injury: Translation From Animal Models And Genetics To Improving Outcomes, Susanne Muehlschlegel, Nils Henninger, Raphael Carandang, Constance Moore
Nils Henninger
This presentation offers background information on traumatic brain injury (TBI), a public health problem which affects approximately 1.7 million Americans each year. The presentation is part of a mini-symposium highlighting the interdisciplinary and translational nature of TBI research at the University of Massachusetts Medical School.
Long-Term Changes Of Functional Mri-Based Brain Function, Behavioral Status, And Histopathology After Transient Focal Cerebral Ischemia In Rats, Kenneth Sicard, Nils Henninger, Marc Fisher, Timothy Duong, Craig Ferris
Long-Term Changes Of Functional Mri-Based Brain Function, Behavioral Status, And Histopathology After Transient Focal Cerebral Ischemia In Rats, Kenneth Sicard, Nils Henninger, Marc Fisher, Timothy Duong, Craig Ferris
Nils Henninger
BACKGROUND AND PURPOSE: The relation between recovery of brain function and neurological status after clinical and experimental cerebral ischemia is incompletely characterized. We assessed the evolution of ischemic injury, behavioral status, and brain activity at acute to chronic periods after transient middle cerebral artery occlusion (tMCAO) in rats. METHODS: Male Sprague-Dawley rats were subjected to 20-minute tMCAO (n=10) or sham operation (n=10). Sensorimotor behavioral testing and multimodal (diffusion, perfusion, T2, and functional) MRI, as well as postmortem hematoxylin-eosin staining, were performed before and up to 21 days after tMCAO. MRI and histological parameters were evaluated in 5 regions of interest …
Stimulating Circle Of Willis Nerve Fibers Preserves The Diffusion-Perfusion Mismatch In Experimental Stroke, Nils Henninger, Marc Fisher
Stimulating Circle Of Willis Nerve Fibers Preserves The Diffusion-Perfusion Mismatch In Experimental Stroke, Nils Henninger, Marc Fisher
Nils Henninger
BACKGROUND AND PURPOSE: Stimulation of the nerves traversing the ethmoidal foramen (including postsynaptic, parasympathetic projections from the sphenopalatine ganglion [SPG], henceforth referred to as "SPG-stimulation") has been shown to elevate cerebral blood flow (CBF) and to be neuroprotective after permanent, middle cerebral artery occlusion (pMCAO). METHODS: Employing diffusion (DWI)- and perfusion (PWI) weighted MRI, the effect of SPG-stimulation (started at 60 minutes post-MCAO) on the spatiotemporal evolution of ischemia during and after pMCAO was investigated. In an additional experiment, regional CBF changes were investigated in the nonischemic brain. RESULTS: In the nonischemic brain, SPG stimulation significantly elevated CBF predominantly within …
Leukoaraiosis Predicts Poor 90-Day Outcome After Acute Large Cerebral Artery Occlusion, Nils Henninger, Eugene Lin, Stephen Baker, Ajay Wakhloo, Deepak Takhtani, Majaz Moonis
Leukoaraiosis Predicts Poor 90-Day Outcome After Acute Large Cerebral Artery Occlusion, Nils Henninger, Eugene Lin, Stephen Baker, Ajay Wakhloo, Deepak Takhtani, Majaz Moonis
Nils Henninger
BACKGROUND: To date limited information regarding outcome-modifying factors in patients with acute intracranial large artery occlusion (ILAO) in the anterior circulation is available. Leukoaraiosis (LA) is a common finding among patients with ischemic stroke and has been associated with poor post-stroke outcomes but its association with ILAO remains poorly characterized. This study sought to clarify the contribution of baseline LA and other common risk factors to 90-day outcome (modified Rankin Scale, mRS) after stroke due to acute anterior circulation ILAO. METHODS: We retrospectively analyzed 1,153 consecutive patients with imaging-confirmed ischemic stroke during a 4-year period (2007-2010) at a single academic …
Dementia And Risk Of Adverse Warfarin-Related Events In The Nursing Home Setting, Jennifer Tjia, Terry Field, Kathleen Mazor, Jennifer Donovan, Abir Kanaan, George Reed, Peter Doherty, Leslie Harrold, Jerry Gurwitz
Dementia And Risk Of Adverse Warfarin-Related Events In The Nursing Home Setting, Jennifer Tjia, Terry Field, Kathleen Mazor, Jennifer Donovan, Abir Kanaan, George Reed, Peter Doherty, Leslie Harrold, Jerry Gurwitz
Jennifer Tjia
BACKGROUND: Little attention has been focused on the safety of medications administered to treat non illnesses in nursing home residents with dementia. It is unclear whether this population is at increased risk of adverse drug events. OBJECTIVES: To test the hypotheses that in nursing home residents with dementia prescribed warfarin have less time in therapeutic range and a higher incidence of nonpreventable and preventable adverse warfarin events compared to nursing home residents without dementia after controlling for facility and patient characteristics. METHODS: A prospective cohort embedded in a clinical trial of nursing home residents prescribed warfarin in 26 nursing homes …
Association Of Ubqln1 Mutation With Brown-Vialetto-Van Laere Syndrome But Not Typical Als, Paloma Gonzalez-Perez, Yubing Lu, Ru-Ju Chian, Peter Sapp, Rudolph Tanzi, Lars Bertram, Diane Mckenna-Yasek, Fen-Biao Gao, Robert Brown
Association Of Ubqln1 Mutation With Brown-Vialetto-Van Laere Syndrome But Not Typical Als, Paloma Gonzalez-Perez, Yubing Lu, Ru-Ju Chian, Peter Sapp, Rudolph Tanzi, Lars Bertram, Diane Mckenna-Yasek, Fen-Biao Gao, Robert Brown
Dr Robert Brown
Genetic variants in UBQLN1 gene have been linked to neurodegeneration and mutations in UBQLN2 have recently been identified as a rare cause of amyotrophic lateral sclerosis (ALS). OBJECTIVE: To test if genetic variants in UBQLN1 are involved in ALS. METHODS: 102 and 94 unrelated patients with familial and sporadic forms of ALS were screened for UBQLN1 gene mutations. Single nucleotide variants were further screened in a larger set of sporadic ALS (SALS) patients and unrelated control subjects using high-throughput Taqman genotyping; variants were further assessed for novelty using the 1000Genomes and NHLBI databases. In vitro studies tested the effect of …
Gene And Stem Cell Therapies For Treating Epilepsy., Janice Naegele, Xu Maisano
Gene And Stem Cell Therapies For Treating Epilepsy., Janice Naegele, Xu Maisano
Janice R Naegele
No abstract provided.
Long-Term Cardiac Rhythm And Repolarization Abnormalities In Refractory Focal And Generalized Epilepsy, Maromi Nei
Long-Term Cardiac Rhythm And Repolarization Abnormalities In Refractory Focal And Generalized Epilepsy, Maromi Nei
maromi nei
This prospective study evaluated 19 individuals with refractory focal or generalized epilepsy utilizing an implantable cardiac loop recorder. Recording averaged 15 months (range 12–19 months) in 18 patients and 1.5 months in one patient. A median of 37 seizures per patient (range 3–657) occurred, with 1,477 seizures total. Cardiac arrhythmias and repolarization abnormalities occurred frequently (in 42% of patients) in refractory epilepsy, particularly during generalized tonic–clonic and tonic seizures. Patients with Lennox-Gastaut syndrome may be at high risk for cardiac abnormalities.
Exploring The Role Of The Solvent In The Denaturation Of A Protein: A Molecular Dynamics Study Of The Dna Binding Domain Of The 434 Repressor, Celia Schiffer, Volker Dötsch, Kurt Wuthrich, Wilfred Van Gunsteren
Exploring The Role Of The Solvent In The Denaturation Of A Protein: A Molecular Dynamics Study Of The Dna Binding Domain Of The 434 Repressor, Celia Schiffer, Volker Dötsch, Kurt Wuthrich, Wilfred Van Gunsteren
Celia A. Schiffer
Molecular dynamics simulations of the DNA binding domain of 434 repressor are presented which aim at unraveling the role of solvent in protein denaturation. Four altered solvent models, each mimicking various possible aspects of the addition of a denaturant to the aqueous solvent, were used in the simulations to analyze their effects on the stability of the protein. The solvent was altered by selectively changing the Coulombic interaction between water and protein atoms and between different water molecules. The use of a modified solvent model has the advantage of mimicking the presence of denaturant without having denaturant molecules present in …
Does Inorganic Mercury Play A Role In Alzheimer's Disease? A Systematic Review And An Integrated Molecular Mechanism, Joachim Mutter, Annika Curth, Johannes Naumann, Richard Deth, Harald Walach
Does Inorganic Mercury Play A Role In Alzheimer's Disease? A Systematic Review And An Integrated Molecular Mechanism, Joachim Mutter, Annika Curth, Johannes Naumann, Richard Deth, Harald Walach
Richard Deth
Mercury is one of the most toxic substances known to humans. It has been introduced into the human environment and has also been widely used in medicine. Since circumstantial evidence exists that the pathology of Alzheimer’s disease (AD) might be in part caused or exacerbated by inorganic mercury, we conducted a systematic review using a comprehensive search strategy. Studies were screened according to a predefined protocol. Two reviewers extracted relevant data independent of each other. One thousand and forty one references were scrutinized, and 106 studies fulfilled the inclusion criteria. Most studies were case control or comparative cohort studies. Thirty-two …
Pkc Inhibition Increases Gap Junction Intercellular Communication And Cell Adhesion In Human Neuroblastoma, M. Morley, C. Jones, M. Sidhu, V. Gupta, S. Bernier, W. Rushlow, Daniel Belliveau
Pkc Inhibition Increases Gap Junction Intercellular Communication And Cell Adhesion In Human Neuroblastoma, M. Morley, C. Jones, M. Sidhu, V. Gupta, S. Bernier, W. Rushlow, Daniel Belliveau
Daniel J. Belliveau
Abstract Gap junction intercellular communication and cell–cell adhesion are essential for maintaining a normal cellular phenotype, including the control of growth and proliferation. Loss of either cell–cell adhesion or communication is common in cancers, while restoration of function is associated with tumor suppression. Protein kinase C (PKC) isozymes regulate a broad spectrum of cellular functions including growth and proliferation, and their overexpression has been correlated with carcinogenesis. Consequently, PKC inhibitors are currently undergoing clinical trials as an anti-cancer agents although the precise cellular alterations induced by PKC inhibitors remain to be elucidated. In the current study, the effects of PKC …
Connexin Overexpression Differentially Suppresses Glioma Growth And Contributes To The Bystander Effect Following Hsv-Thymidine Kinase Gene Therapy, T. Jiminez, W. Fox, C. Naus, J. Galipeau, Daniel Belliveau
Connexin Overexpression Differentially Suppresses Glioma Growth And Contributes To The Bystander Effect Following Hsv-Thymidine Kinase Gene Therapy, T. Jiminez, W. Fox, C. Naus, J. Galipeau, Daniel Belliveau
Daniel J. Belliveau
Neoplastic transformation is frequently associated with a loss of gap junctional intercellular communication and reduced expression of connexins. The introduction of connexin genes into tumor cells reverses the proliferative characteristics of such cells. However, there is very little comparative information on the effects of different connexins on cancer cell growth. We hypothesized that Cx26, Cx32, or Cx43 would display differential growth suppression of C6 glioma cells and uniquely modulate the bystander effect following transduction of C6 cells with HSVtk followed by suicide gene therapy. The bystander phenomenon is the death of a greater number of tumor cells than are expressing …
Enhanced Neurite Outgrowth In Pc12 Cells Mediated By Connexin Hemichannels And Atp, Daniel Belliveau, M. Bani-Yagoub, R. Mcgirr, C. Naus, W. Rushlow
Enhanced Neurite Outgrowth In Pc12 Cells Mediated By Connexin Hemichannels And Atp, Daniel Belliveau, M. Bani-Yagoub, R. Mcgirr, C. Naus, W. Rushlow
Daniel J. Belliveau
Gap junctions have traditionally been described as transmembrane channels that facilitate intercellular communication via the passage of small molecules. Connexins, the basic building blocks of gap junctions, are expressed in most mammalian tissues including the developing and adult central nervous system. During brain development, connexins are temporally and spatially regulated suggesting they play an important role in the proper formation of the central nervous system. In the current study, connexins 32 and 43 were overexpressed in PC12 cells to determine whether connexins are involved in neuronal differentiation. Both connexin 32 and 43 were appropriately trafficked to the cell membrane following …
Changes In Calcineurin Expression Induced In The Rat Brain By The Administration Of Antipsychotics, W. Rushlow, Y. Seah, Daniel Belliveau, N. Rajakumar
Changes In Calcineurin Expression Induced In The Rat Brain By The Administration Of Antipsychotics, W. Rushlow, Y. Seah, Daniel Belliveau, N. Rajakumar
Daniel J. Belliveau
Calcineurin (CN) was recently identified as a susceptibility gene for schizophrenia as well as showing altered RNA expression levels in the post-mortem brains of individuals with schizophrenia. CN knockout mice show a number of behaviours associated with schizophrenia, including deficits in sensorimotor gating, suggesting a link between CN and psychosis. Concurrently, we found, using genome screening techniques, that antipsychotics alter CN expression levels. Therefore, western blotting, in situ hybridization, immunocytochemistry and phosphatase assays were employed to determine what effect antipsychotics have on CN. The results indicate that clozapine, risperidone and haloperidol cause substantial reductions in the A subunit of CN …
Nerve Growth Factor Increases Connexin43 Phosphorylation And Gap Junctional Intercellular Communication, P. Cushing, R. Bhalla, A. Johnson, W. Rushlow, S. Meakin, Daniel Belliveau
Nerve Growth Factor Increases Connexin43 Phosphorylation And Gap Junctional Intercellular Communication, P. Cushing, R. Bhalla, A. Johnson, W. Rushlow, S. Meakin, Daniel Belliveau
Daniel J. Belliveau
The function of gap junctions is regulated by the phosphorylation state of their connexin subunits. Numerous growth factors are known to regulate connexin phosphorylation; however, the effect of nerve growth factor on gap junction function is not understood. The phosphorylation of connexin subunits is a key event during many aspects of the lifecycle of a connexin, including open/close states, assembly/trafficking, and degradation, and thus affects the functionality of the channel. PC12 cells infected with connexin43 (Cx43) retrovirus were used as a neuronal model to characterize the signal transduction pathways activated by nerve growth factor (NGF) that potentially affect the functional …
Retroviral Delivery Of Connexin Genes To Human Breast Tumor Cells Inhibits In Vivo Tumor Growth By A Mechanism That Is Independent Of Significant Gap Junctional Intercellular Communication, H. Qin, Q. Shao, H. Curtis, J. Galipeau, Daniel Belliveau, T. Wang, M. Alaoui-Jamali, D. Laird
Retroviral Delivery Of Connexin Genes To Human Breast Tumor Cells Inhibits In Vivo Tumor Growth By A Mechanism That Is Independent Of Significant Gap Junctional Intercellular Communication, H. Qin, Q. Shao, H. Curtis, J. Galipeau, Daniel Belliveau, T. Wang, M. Alaoui-Jamali, D. Laird
Daniel J. Belliveau
The mechanism by which gap junction proteins, connexins, act as potent tumor suppressors remains poorly understood. In this study human breast tumor cells were found to exhibit diverse gap junction phenotypes including (a) undetectable Cx43 and no intercellular communication (HBL100); (b) low levels of Cx43 and sparse intercellular communication (MDA-MB-231); and (c) significant levels of Cx43 and moderate intercellular communication (Hs578T). Although retroviral delivery of Cx43 and Cx26 cDNAs to MDA-MB-231 cells did not achieve an expected substantial rescue of intercellular communication, overexpression of connexin genes did result in a dramatic suppression of tumor growth when connexin-expressing MDA-MB-231 cells were …
Aggregated Dsred-Tagged Cx43 And Over-Expressed Cx43 Are Targeted To Lysosomes In Human Breast Cancer Cells, H. Qin, Q. Shao, Daniel Belliveau, D. Laird
Aggregated Dsred-Tagged Cx43 And Over-Expressed Cx43 Are Targeted To Lysosomes In Human Breast Cancer Cells, H. Qin, Q. Shao, Daniel Belliveau, D. Laird
Daniel J. Belliveau
To investigate if either wild-type or aggregated Cx43 is abnormally targeted to lysosomes in human breast tumor cells, we examined the fate of DsRed-tagged Cx43 and over-expressed Cx43 in communication-deficient HBL-100 and MDA-MB-231 cells. DsRed-tagged Cx43 was assembled into gap junctions in control normal rat kidney cells that express endogenous Cx43 but not in Cx43-negative HBL-100 cells. However, when HBL-100 cells were engineered to coexpress wild-type Cx43 a population of DsRed-tagged Cx43 was rescued and assembled into gap junctions. Co-expression of wild-type Cx26 failed to rescue the assembly of DsRed-tagged Cx43 into gap junctions. Immunolocalization studies revealed that DsRed-tagged Cx43 …
Viral Shedding And Biodistribution Of G207, A Multimutated, Conditionally Replicating Herpes Simplex Virus Type 1, After Intracerebral Inoculation In Aotus, T. Todo, F. Feigenbaum, S. Rabkin, F. Lakeman, J. Newsome, P. Johnson, E. Mitchell, Daniel Belliveau, J. Ostrove, R. Martuza
Viral Shedding And Biodistribution Of G207, A Multimutated, Conditionally Replicating Herpes Simplex Virus Type 1, After Intracerebral Inoculation In Aotus, T. Todo, F. Feigenbaum, S. Rabkin, F. Lakeman, J. Newsome, P. Johnson, E. Mitchell, Daniel Belliveau, J. Ostrove, R. Martuza
Daniel J. Belliveau
G207 is a multimutated, conditionally replicating herpes simplex virus type 1 (HSV-1) that is currently in clinical trial for patients with malignant glioma. G207 exhibits an efficient oncolytic activity in tumor cells, yet minimal toxicity in normal tissue when injected into the brains of HSV-susceptible mice or nonhuman primates. In this study, we evaluated the shedding and biodistribution of clinical-grade G207 after intracerebral inoculation (3 × 107 pfu) in four New World owl monkeys (Aotus nancymae). Using PCR analyses and viral cultures, neither infectious virus nor viral DNA was detected from tear, saliva, or vaginal secretion samples at any time …
Neuropsychiatry Of Movement Disorders, Kevin J. Black, Jonathan W. Mink
Neuropsychiatry Of Movement Disorders, Kevin J. Black, Jonathan W. Mink
Kevin J. Black, MD
Movement disorders include both psychiatric illnesses with neurologic features and neurologic illnesses with frequent psychiatric complications. During 1998, neuropsychiatric progress was made on several fronts, notably in parkinsonism and tic disorders. This remains an exciting area for research, with many unsolved, clinically important problems, but with increasing neurobiologic knowledge and sophistication.
Autocrine Hepatocyte Growth Factor Provides A Local Mechanism For Promoting Axonal Growth, X. Yang, J. Toma, S. Bamji, Daniel Belliveau, J. Kohn, M. Park, F. Miller
Autocrine Hepatocyte Growth Factor Provides A Local Mechanism For Promoting Axonal Growth, X. Yang, J. Toma, S. Bamji, Daniel Belliveau, J. Kohn, M. Park, F. Miller
Daniel J. Belliveau
In this report, we describe a novel local mechanism necessary for optimal axonal growth that involves hepatocyte growth factor (HGF). Sympathetic neurons of the superior cervical ganglion coexpress bioactive HGF and its receptor, the Met tyrosine kinase, both in vivo and in vitro. Exogenous HGF selectively promotes the growth but not survival of cultured sympathetic neurons; the magnitude of this growth effect is similar to that observed with exogenous NGF. Conversely, HGF antibodies that inhibit endogenous HGF decrease sympathetic neuron growth but have no effect on survival. This autocrine HGF is required locally by sympathetic axons for optimal growth, as …
Differential Expression Of Gap Junctions In Neurons And Astrocytes Dervied From P19 Embryonal Carcinoma Cells, Daniel Belliveau, J. Bechberger, K. Rodgers, C. Naus
Differential Expression Of Gap Junctions In Neurons And Astrocytes Dervied From P19 Embryonal Carcinoma Cells, Daniel Belliveau, J. Bechberger, K. Rodgers, C. Naus
Daniel J. Belliveau
The P19 embryonal carcinoma cell line represents a pluripotential stem cell that can differentiate along the neural or muscle cell lineage when exposed to different environments. Exposure to retinoic acid induces P19 cells to differentiate into neurons and astrocytes that express similar developmental markers as their embryonic counterparts. We examined the expression of gap junction genes during differentiation of these stem cells into neurons and astrocytes. Untreated P19 cells express at least two gap junction proteins, connexins 26 and 43. Connexin32 could not be detected in these cells. Treatment for 96 hr with 0.3 mM retinoic acid induced the P19 …
Blocking Nerve Growth Factor Binding To The P75 Neurotrophin Receptor On Sympathetic Neurons Transiently Reduces Trka Activation But Does Not Affect Neuronal Survival, C. Lachance, Daniel Belliveau, P. Barker
Blocking Nerve Growth Factor Binding To The P75 Neurotrophin Receptor On Sympathetic Neurons Transiently Reduces Trka Activation But Does Not Affect Neuronal Survival, C. Lachance, Daniel Belliveau, P. Barker
Daniel J. Belliveau
Nerve growth factor interacts with the trkA tyrosine kinase receptor and with the p75 neurotrophin receptor. It is clear that trkA mediates most, if not all, of the stereotypical responses of sympathetic neurons to nerve growth factor but the role of the p75 neurotrophin receptor is unclear. In this study, we have asked whether a functional interaction between p75 neurotrophin receptor and trkA exists in primary sympathetic neurons by disrupting nerve growth factor binding to p75 neurotrophin receptor. Acute assays reveal that blocking antibodies directed against p75 neurotrophin receptor reduce nerve growth factor-mediated trkA tyrosine phosphorylation and reduce the amount …
Transgenic Mice Expressing The Intracellular Domain Of The P75 Neurotrophin Receptor Undergo Neuronal Apoptosis, M. Majdan, C. Lachance, A. Gloster, R. Aloyz, C. Zeindler, S. Bamji, A. Bhakar, Daniel Belliveau, J. Fawcett, F. Miller, P. Barker
Transgenic Mice Expressing The Intracellular Domain Of The P75 Neurotrophin Receptor Undergo Neuronal Apoptosis, M. Majdan, C. Lachance, A. Gloster, R. Aloyz, C. Zeindler, S. Bamji, A. Bhakar, Daniel Belliveau, J. Fawcett, F. Miller, P. Barker
Daniel J. Belliveau
We have asked whether p75NTR may play a role in neuronal apoptosis by producing transgenic mice that express the p75NTR intracellular domain within peripheral and central neurons. These animals showed profound reductions in numbers of sympathetic and peripheral sensory neurons as well as cell loss in the neocortex, where there is normally little or no p75NTR expression. Developmental loss of facial motor neurons was not observed, but induced expression of the p75NTR intracellular domain within adult animals led to increased motor neuron death after axotomy. Biochemical analyses suggest that these effects were not attributable to a p75NTR-dependent reduction in trk …
Ngf And Neurotrophin-3 Both Activate Trka On Sympathetic Neurons But Differentially Regulate Survival And Neuritogenesis, Daniel Belliveau, I. Krivko, C. Lachance, J. Kohn, D. Rusakov, D. Kaplan, F. Miller
Ngf And Neurotrophin-3 Both Activate Trka On Sympathetic Neurons But Differentially Regulate Survival And Neuritogenesis, Daniel Belliveau, I. Krivko, C. Lachance, J. Kohn, D. Rusakov, D. Kaplan, F. Miller
Daniel J. Belliveau
In this report we examine the biological and molecular basis of the control of sympathetic neuron differentiation and survival by NGF and neurotrophin-3 (NT-3). NT-3 is as efficient as NGF in mediating neuritogenesis and expression of growth-associated genes in NGF-dependent sympathetic neurons, but it is 20-40-fold less efficient in supporting their survival. Both NT-3 and NGF induce similar sustained, long-term activation of TrkA, while NGF is 10-fold more efficient than NT-3 in mediating acute, short-term TrkA activity. At similar acute levels of TrkA activation, NT-3 still mediates neuronal survival two- to threefold less well than NGF. However, a mutant NT-3 …
Adenovirus-Mediated Gene Transfer Of The Tumor Suppressor, P53, Induces Apoptosis In Postmitotic Neurons, R. Slack, Daniel Belliveau, M. Rosenberg, J. Atwal, H. Lochmuller, R. Aloyz, A. Haghighi, B. Lach, P. Seth, E. Cooper, F. Miller
Adenovirus-Mediated Gene Transfer Of The Tumor Suppressor, P53, Induces Apoptosis In Postmitotic Neurons, R. Slack, Daniel Belliveau, M. Rosenberg, J. Atwal, H. Lochmuller, R. Aloyz, A. Haghighi, B. Lach, P. Seth, E. Cooper, F. Miller
Daniel J. Belliveau
Programmed cell death is an ongoing process in both the developing and the mature nervous system. The tumor suppressor gene, p53, can induce apoptosis in a number of different cell types. Recently, the enhanced expression of p53 has been observed during acute neurological disease. To determine whether p53 overexpression could influence neuronal survival, we used a recombinant adenovirus vector carrying wild type p53 to transduce postmitotic neurons. A control consisting of the same adenovirus vector background but carrying the lacZ reporter expression cassette was used to establish working parameters for the effective genetic manipulation of sympathetic neurons. We have found …
Cortical Type 2 Astrocytes Are Not Dye Coupled Nor Do They Express The Major Gap Junction Genes Found In The Central Nervous System, Daniel Belliveau, C. Naus
Cortical Type 2 Astrocytes Are Not Dye Coupled Nor Do They Express The Major Gap Junction Genes Found In The Central Nervous System, Daniel Belliveau, C. Naus
Daniel J. Belliveau
The O‐2A progenitor cell first described from the rat optic nerve is a bipotential precursor of oligodendrocytes and type 2 astrocytes. Each cell expresses specific markers that distinguish them as unique cell types. O‐2A progenitors cultured in high serum preferentially differntiate into type 2 astrocytes and when exposed to defined medium or low serum develop along the oligodendrocyte lineage. We analyzed the gap junction gene expression of type 2 astrocytes to determine if they are coupled to form a syncytium, like their type 1 astrocyte counterparts. Dye coupling experiments demonstrated that cortical type 2 astrocytes are not coupled, while type …
In Vivo Growth Of C6 Glioma Cells Transfected With Connexin43 Cdna, C. Naus, K. Elisevich, D. Zhu, Daniel Belliveau, R. Del Maestro
In Vivo Growth Of C6 Glioma Cells Transfected With Connexin43 Cdna, C. Naus, K. Elisevich, D. Zhu, Daniel Belliveau, R. Del Maestro
Daniel J. Belliveau
In order to examine the possible role of intercellular communication via gap junctions in the control of tumor growth, we have transfected C6 glioma cells with connexin43 cDNA. We obtained several clones with variable expression of connexin43. The growth rate of these clones in culture was inversely related to the degree of expression of the transfected cDNA. To examine the growth of these transfected cells in vivo, cells were grown in spinner culture flasks to form spheroids 250–300 µm in diameter. Spheroids of nontransfected C6 cells produced large gliomas. Immunohistochemical and in situ hybridization analyses revealed relatively high levels of …