A5022062972- Neurogenesis and neuroplasticity mechanisms
- Neuroinflammation and Neurodegeneration Mechanisms
- Glycosylation and Glycoproteins Research
- Multiple Sclerosis Research Studies
- Nerve injury and regeneration
- Biochemical effects in animals
- Neuroscience and Neuropharmacology Research
- MicroRNA in disease regulation
- Immune Response and Inflammation
- Lipid Membrane Structure and Behavior
- Metabolism and Genetic Disorders
- Peroxisome Proliferator-Activated Receptors
- Alzheimer's disease research and treatments
- Diet and metabolism studies
- Mitochondrial Function and Pathology
- Neurological Disorders and Treatments
- Fatty Acid Research and Health
- melanin and skin pigmentation
- Pharmacological Effects of Natural Compounds
- Regulation of Appetite and Obesity
- RNA Interference and Gene Delivery
- Cytokine Signaling Pathways and Interactions
- Natural product bioactivities and synthesis
- RNA regulation and disease
- Lipid metabolism and biosynthesis
Wayne State University
2012-2023
University of Pennsylvania
1972-2019
Montreal Neurological Institute and Hospital
2019
McGill University
2019
Detroit Medical Center
1998-2012
Neurology, Inc
2007
University of North Carolina at Chapel Hill
1974-1977
Detroit R&D (United States)
1977
National Institutes of Health
1969-1977
University of Michigan–Ann Arbor
1969-1976
Methamphetamine intoxication causes long-lasting damage to dopamine nerve endings in the striatum. The mechanisms underlying this neurotoxicity are not known but oxidative stress has been implicated. Microglia major antigen-presenting cells brain and when activated, they secrete an array of factors that cause neuronal damage. Surprisingly, very little work directed at study microglial activation as part methamphetamine neurotoxic cascade. We report here activates microglia a dose-related...
Abstract— CDP‐diglyceride is converted to phosphatidyl inositol by several particulate subcellular fractions of guinea pig brain, with highest specific activity in the microsomal fraction. Optimal conditions respect pH, metal ion concentration, and substrate concentrations have been determined. The reaction was stimulated addition bovine serum albumin Tween 80. Of dl ‐CDP‐diglycerides synthesized used as substrates a spectrophoto‐metric assay for enzyme, ‐CDP‐didecanoin most active. enzyme...
B cells can be enriched within meningeal immune-cell aggregates of multiple sclerosis (MS) patients, adjacent to subpial cortical demyelinating lesions now recognized as important contributors progressive disease. This demyelination is notable for a 'surface-in' gradient neuronal loss and microglial activation, potentially reflecting the effects soluble factors secreted into CSF. We previously demonstrated that MS B-cell products are toxic oligodendrocytes neurons. The potential...
This is the first study to provide evidence that one function for surface glycolipid galactocerebroside (GalC) participation in opening of Ca2+ channels oligodendroglia culture. a unique differentiation marker myelin-producing cells; antibodies GalC have been shown markedly alter oligodendroglial morphology via disruption microtubules (Dyer, C. A., and J. A. Benjamins. 1988. Neurosci. 8:4307-4318). demonstrates extracellular EGTA blocks anti-GalC-induced disassembly membrane sheets,...
Membrane sheets elaborated by cultured murine oligodendroglia provide a unique system for examining associations between myelin proteins and cytoskeletal elements. Interactions can be observed manipulated more readily than in the multilamellar membrane vivo. Immunocytochemical staining of 2',3'-cyclic nucleotide 3'-phosphohydrolase (CNPase) shows that it is distributed diffusely some regions sheets, but colocalized with tubulin lacy networks major veins other regions. Staining phalloidin...
Abstract— Partially purified myelin from the brains of 17‐day‐old rats was separated into 4 subfractions on a three‐step sucrose gradient by virtue heterogeneity in density and particle size. Precursor‐product relationships between different membrane fractions were investigated determining specific radioactivity individual lipids each subcellular fraction 15 min after intracranial injection an appropriate precursor. Rats injected with [2‐ 3 H]glycerol. prepared, TLC. For choline ethanolamine...
The incorporation of fatty acid into myelin proteolipid protein (PLP) was studied by incubating brain slices from 17-day-old rats with [9,10-3H]palmitic acid. Myelin proteins were analyzed gel electrophoresis. As in vivo (Agrawal, H. C., Randle, C. L., and Agrawal, D. (1982) J. Biol. Chem. 257, 4588-4592) most the radioactivity co-migrated PLP, also appearing regions DM-20 Wolfgram proteins. Treatment or purified PLP 1 M hydroxylamine released radioactivity, indicating that [3H]palmitic...
Abstract Centrifugation of isolated myelin on discontinuous sucrose gradients resulted in a separation into three bands and pellet. The were morphologically identical to myelin, whereas the pellet consisted primarily vesicular membranes. These four fractions differed from one another their lipid‐to‐protein ratios molar cholesterol:phospholipid:galactolipid. All contained proteins typical although proportions varied, with being lowest basic protein proteolipid protein. High activity...
Abstract Antibodies to galactocerebroside (GalC) cause patching of this surface glycolipid over internal domains myelin basic protein (MBP), which are demarcated by a network microtubules. The occurs whether or not second antibody is present, but the process accelerated presence antibody. GalC results in disruption microtubules lacy networks oligodendroglial membrane sheets and eventual fusion MBP domains, similar effects colchicine (Dyer Benjamins, 1989). also disrupt F‐actin networks....
Abstract Brain slices were prepared from 17‐day old rats, and incubated with [ 3 H]glycine or H]‐leucine to label proteins. Myelin was isolated the slices, proteins separated by discontinuous gel electrophoresis in buffers containing sodium dodecyl sulfate. Radioactive basic Wolfgram appeared myelin at similar initial rates, their entry nearly linear between 15 120 min no detectable lag. proteolipid protein one‐fourth rate of 0 30 min, then entered a comparable other 45 min. When...
Abstract— Partially purified myelin from brains of 17‐day‐old rats was separated into 4 subfractions on a discontinuous sucrose gradient by virtue heterogeneity in density and particle size. The protein composition each subfraction determined densitometry following separation proteins polyacrylamide gels buffers containing sodium dodecyl sulphate. major studied included two basic proteins, proteolipid protein, the high molecular weight (W) group proteins. percentage decreased sequentially...
Abstract— Explants of rat cerebellum obtained 12‐24 h after birth were maintained in culture Maximow assemblies. About 90 per cent the cultures myelinated 10–12 days vitro . Cultures for varying periods time exposed to [ 35 S]Na 2 SO 4 ; labelled sulphatide was recovered from total homogenate. Preparation a subcellular fraction with density properties corresponding those myelin indicated that appeared this fraction. which poorly‐myelinated always exhibited lower rate inccrpomtion than...
Interactions between cytokines and Schwann cells (SC) are important in development, repair, disorders of the peripheral nervous system (PNS). Tumor necrosis factor-α (TNF-α) transforming growth factor-β (TGF-β) two prominent which may be involved these processes their gene products upregulated some experimental neuropathies. This study focuses on thein vitro effects cytokines, both singly combination, cultured SC. Expression Type I II TNF-α receptors was demonstrated SC surface by...
Abstract Galactocerebroside (GalC) and sulfated galactocerebroside (sulfatide) are sphingolipids highly enriched in myelin. The binding of antibodies reactive with either sulfatide Or GalC to cultured Oligodendrocytes causes a Ca 2+ influx, followed by microtubule depo lymerization; however, antisulfatide is less effective than anti‐GalC altering cytoskeleton. Typical responses delayed for both but transient sulfatide‐reactive contrast the sustained previously reported (Dyer Benjamins, J...
Type 1 neurofibromatosis (NF1) is a common autosomal dominant disorder that results in neuroectodermal tumors. The NF1 tumor-suppressor gene encodes neurofibromin, which includes GTPase-activating domain for Ras inactivation. Affinity purification showed N-Ras to be the predominant activated isoform of two independent neurofibrosarcoma cell lines from patients (lines ST88-14 and NF90-8). These cells also demonstrated increased constitutive activity extracellular signal-regulated kinases 2...
Immunocytochemistry and thymidine autoradiography were combined to determine the time elapsed between cell division expression of proteolipid protein (PLP) in individual oligodendrocytes normal mouse brain. In jimpy (jp) brains, was used an oligodendrocyte evidence death. Oligodendrocytes brain do not express PLP until 72 h after a single injection [3H]-thymidine. contrast, jp brains begin die within 9-11 thymidine. The is one several X-linked, hypomyelinated mutants which defect has been...