Search Results
Results 451 - 500 of 1177
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Sugimoto Y - - 2001
Oligodendrocyte precursors are produced in restricted foci of the germinative neuroepithelium in embryo brains and migrate to their sites of function, while astrocytes are produced in a wider area in the neuroepithelium. We investigated the guidance mechanisms of glial precursor (GP) cell migration in the optic nerve. GP cell migration ...
Fullen D R - - 2001
BACKGROUND: Melanocytic nevi typically show a morphologic sequence of maturation from epithelioid "type A" cells to fusiform, Schwann cell-like "type C" cells with dermal descent. Nevi may also produce Wagner-Meissner-like structures (nevic corpuscles). Previous studies have shown that this maturation of intradermal nevi recapitulates intermediate stages in Schwann cell development. ...
Tolbert D L - - 2001
Cerebellar Purkinje cells degenerate in shaker mutant rats. Glia cell line-derived neurotrophic factor (GDNF) was chronically infused intraventricularly in an attempt to rescue mutant Purkinje cells from dying. Four weeks of chronic GDNF infusion delayed the degeneration of many but not all Purkinje cells. Surviving Purkinje cells formed spatially related ...
Tu S - - 2001
Neurotransmitter expression can be regulated by both activity and neurotrophins in a number of in vitro systems. We examined whether either of these factors was likely to play a role in the in vivo optic nerve-dependent regulation of a substance P-like immunoreactive (SP-ir) population of cells in the developing optic ...
Liu Y - - 2001
Postnatal cerebellum development involves the generation of granule cells and Bergmann glias (BGs). The granule cell precursors are located in the external germinal layer (EGL) and the BG precursors are located in the Purkinje layer (PL). BGs extend their glial fibers into the EGL and facilitate granule cells' inward migration ...
Chuenkova M V - - 2001
Patients infected with Trypanosoma cruzi may remain asymptomatic for decades and show signs of neuroregeneration in the peripheral nervous system (PNS). In the absence of such neuroregeneration, patients may die in part by extensive neuronal destruction in the gastrointestinal tract. Thus, T. cruzi may, despite their invasion of the PNS, ...
Fan H - - 2001
Cerebellar Purkinje cells and granule cells have been studied extensively as models for investigating neuron-target interactions and the regulation of cell numbers in the developing central nervous system. Recent studies of transgenic mice that overexpress a human Bcl-2 transgene in Purkinje cells suggest both that programmed cell death plays an ...
Beierbach E - - 2001
Purkinje cells of different molecular phenotypes subdivide the cortex of the cerebellum both rostrocaudally into parasagittal bands and mediolaterally into transverse zones. Superimposed on the Purkinje cell compartmentation, the cerebellar cortex is pleated into a reproducible array of lobes and lobules. During cerebellar development, Purkinje cell bands are formed through ...
Feng J - - 2001
Kv3.1, a voltage-dependent potassium channel, has two forms, -a and -b, which differ in expression during development and at the onset of function in the auditory system. To determine whether cochlear nerve input could affect the expression of these two forms, cultures of the developing cochlear nucleus were explanted in ...
Perry A - - 2001
Although plexiform neurofibroma (PN) is thought to represent a benign neoplasm with the potential for malignant transformation (malignant peripheral nerve sheath tumor; MPNST), its neoplastic nature has been difficult to prove due to cellular heterogeneity, which hampers standard molecular genetic analysis. Its mixed composition typically includes Schwann cells, fibroblasts, perineurial-like ...
Gijtenbeek J M - - 2001
The authors report a patient with neurofibromatosis type 2 (NF2) presenting with an axonal mononeuropathy multiplex. Sural nerve biopsy showed small scattered groups of Schwann cells transformed into irregular branching cells with abnormal cell-cell contacts. The authors hypothesize that defective Schwann cell function, due to inactivation of the NF2 gene ...
Persson-Sjögren S - - 2001
The neuroinsular complex type 1 is composed of pancreatic endocrine islet cells and nerve cell bodies intrinsic to the islet. The details of the relation between nerve cells and between endocrine cells and nerve cells in the complex are unknown. Pancreata from newborn and 18-day-old mice were analysed by electron ...
Thompson D M - - 2001
In the peripheral nervous system, Schwann cells are closely associated with, and play key roles in, the development, maintenance, and regeneration of peripheral neurons. Following injury, Schwann cell orientation may also play a role in guiding regenerating axons. To aid in the investigation of these interactions between Schwann cells and ...
Watabe K - - 2001
Niemann-Pick disease type C (NPC) is characterized by an accumulation of unesterified cholesterol in the endosomal/lysosomal (E/L) system, resulting in progressive neurodegeneration and death during early childhood. To investigate the cellular pathomechanism of nervous system involvement in NPC, continuous neural cell lines are desirable. In this study, we obtained neuronal ...
Graça D L - - 2001
Oligodendrocytes and Schwann cells are engaged in myelin production, maintenance and repairing respectively in the central nervous system (CNS) and the peripheral nervous system (PNS). Whereas oligodendrocytes act only within the CNS, Schwann cells are able to invade the CNS in order to make new myelin sheaths around demyelinated axons. ...
Sun X Z - - 2001
Laboratory mice carrying the nonfunctional xeroderma pigmentosum group G gene (the mouse counterpart of the human XPG gene) alleles have been generated by using gene-targeting and embryonic stem cell technology. Homozygote animals of this autosomal recessive disease exhibited signs and symptoms, such as postnatal growth retardation, reduced levels of activity, ...
Spierings E - - 2001
Peripheral nerve damage is a major complication of reversal (or type-1) reactions in leprosy. The pathogenesis of nerve damage remains largely unresolved, but detailed in situ analyses suggest that type-1 T cells play an important role. Mycobacterium leprae is known to have a remarkable tropism for Schwann cells of the ...
Weinstein D E - - 2001
Schwann cells are the glial cells of the peripheral nervous system (PNS) which both myelinate and provide trophic support for their associated axons. Their functions are critical for proper development, homeostasis, and regeneration of the PNS. Schwann cells can be isolated and expanded in culture. Such a culture can be ...
Haack H - - 2001
Proliferation and survival of Schwann cells are important for nerve development and for disease processes in peripheral nerves. We have analyzed embryos lacking alpha4- or alpha5-integrins and show here that these integrins contribute to the control of glial cell numbers. To overcome early embryonic lethality an explant and grafting system ...
Raisman G - - 2001
Several recent publications describe remarkably promising effects of transplanting olfactory ensheathing cells as a potential future method to repair human spinal cord injuries. But why were cells from the nose transplanted into the spinal cord? What are olfactory ensheathing cells, and how might they produce these beneficial effects? And more ...
Cordeiro J M - - 2001
We investigated action potentials and Ca(2+) transients in rabbit Purkinje myocytes using whole cell patch clamp recordings and a confocal microscope. Purkinje cells were loaded with 5 microM Fluo-3/AM for 30min. Action potentials were elicited by application of a stimulus delivered through the recording pipettes. When Purkinje cells were stimulated ...
Vitale P - - 2001
A transgenic mouse line expressing the lacZ reporter under the control of a regulatory region of the col6a1 gene has been used to investigate differentiation of Schwann cells. The data suggest that: (1) activation of col6a1 gene transcription in the peripheral nervous system is part of the differentiation program of ...
Meintanis S - - 2001
Neuregulins constitute a family of related growth factors that play important roles in Schwann cell development and maturation. We investigated the involvement of beta-neuregulin in Schwann cell migration, using a simple in vitro bioassay. Pure Schwann cells were prepared from the sciatic nerves of 5-day-old rats and were grown in ...
Wu R - - 2001
The POU family of transcription factors plays a vital role in controlling cell-fate determination and the timing of cellular events in a number of tissues, including the nervous system. One such POU protein, SCIP, is expressed by Schwann cells in a tightly delimited developmental window termed promyelination. In the PNS, ...
Usuki S - - 2001
We previously reported that ciliary neurotrophic factor (CNTF) increased the serum-free cell survival of immortalized motor neuron-like cells (NSC-34), and addition of the exogenous ganglioside GalNAc beta4(Neu5Ac alpha3)Gal beta4GlcCer (GM2) facilitated cell survival together with CNTF. Moreover beta 1,4 N-acetylgalactosaminyltransferase (GM2 synthase) activity increased in NSC-34 cells cultured with CNTF. ...
Bermingham J R JR - - 2001
Many aspects of the response of Schwann cells to axonal cues can be induced in vitro by the adenylyl cyclase activator forskolin, yet the role of cAMP signaling in regulating Schwann cell differentiation remains unclear. To define better the relationship between cAMP signaling and Schwann cell differentiation, we used a ...
Hadj-Sahraoui N - - 2001
Staggerer (Rora(sg/sg)) is an autosomal mutation in an orphan nuclear hormone receptor gene, RORalpha, that acts intrinsically within the Purkinje cells and causes dysgenesis of the cerebellar cortex. Purkinje cell number is severely reduced, and the surviving cells are small with poorly developed dendrites. In contrast, the cytoarchitecture of the ...
Schneider S - - 2001
The expression of the 330 kDa AN2 glycoprotein was studied in the rodent peripheral nervous system. AN2 is expressed by immature Schwann cells in vitro and in vivo and downregulated as the cells upregulate myelin genes. A subpopulation of nonmyelinating Schwann cells in the adult sciatic nerve retains expression of ...
Rambukkana A - - 2001
Mycobacterium leprae, the causative organism of leprosy, has a unique predilection for Schwann cells, the glial cells of the peripheral nervous system. M. leprae invasion of Schwann cells leads to the neurological damage that underlies the sensory motor loss and subsequent deformity and disability associated with this disease. Recent studies ...
Young D B - - 2001
A recent study has demonstrated that the species-specific phenolic glycolipid of Mycobacterium leprae triggers uptake into Schwann cells by interaction with laminin-2 and the alpha-dystroglycan receptor. This finding emphasizes the importance of lipids in the biology of mycobacterial infection and suggests possible strategies to combat nerve damage in leprosy.
Abromson-Leeman S - - 2001
CD40 ligand-CD40 interactions are important in the development of experimental autoimmune encephalomyelitis (EAE), but it is unclear whether this interaction is critical for de novo recruitment of T cells, entry of T cells into the central nervous system (CNS), or effector function of T cells in vivo. In this report ...
Hartell N A - - 2001
cGMP is thought to play a role in cerebellar signalling yet its production within Purkinje cells has never been detected. In the present study, the hydrolysis of a fluorescent substrate analogue, 2'-O-anthranyloyl cyclic GMP, by type 5 phosphodiesterase was monitored within Purkinje cells in slices and in culture. Nitric oxide, ...
Brierley C M - - 2001
Areas of demyelination can be remyelinated by transplanting myelin-forming cells. Schwann cells are the naturally remyelinating cells of the peripheral nervous system and have a number of features that may make them attractive for cell implantation therapies in multiple sclerosis, in which spontaneous but limited Schwann cell remyelination has been ...
Hadlock T A - - 2001
This study hypothesized that introducing high numbers of Schwann cells in monolayers via a novel rolled graft architecture would promote robust nerve regeneration. The objective was to place adherent Schwann cells in artificial nerve grafts and to assess regeneration through the Schwann cell-laden grafts compared with that through acellular grafts ...
Stark B B Department of Reconstructive Plastic Surgery, Karolinska Hospital, Stockholm, Sweden. - - 2001
The neurotrophin family mediates effects of growth, cell differentiation and cell death through low- and high-affinity transmembrane receptors. The Pacinian corpuscle (PC) is the largest peripheral mechanoreceptor in mammals and was studied by immuno-histochemistry and immuno-electron microscopy with regard to the distribution of neurotrophin receptors, p75; p140 trkA, p145 trkB ...
Hu M - - 2000
Hyaluronic acid (HyA) has the intrinsic ability to promote cell proliferation and reduce scar formation. However, the clinical use of HyA has so far been limited because of its water solubility and nonadhesive characteristics. Increasing interest in HyA as a clinically useful biomaterial has prompted our study of altering HyA's ...
Spierings E - - 2000
Damage to peripheral nerves is the major complication of reversal (type I) reactions in leprosy. The underlying mechanism of nerve damage remains largely unresolved; however, an important role for type-1 T cells has been suggested. Mycobacterium leprae has a remarkable tropism for the Schwann cells that surround peripheral axons. Because ...
Keilhoff G - - 2000
Schwann cells are used in combination with biological matrices as tissue engineered nerve grafts in animal models offering a new therapeutic approach for treatment of lesions of the peripheral nervous system. A high yield of human Schwann cells from adult donors is only achieved by pharmacological stimulation, which should, however, ...
Brennan A - - 2000
Schwann cell precursors, derivatives of the neural crest, generate Schwann cells in a process that is tightly timed, well characterized, and directly controlled by axonal signals, in particular beta-neuregulins. Here we provide evidence that endothelins (ETs) are also important for survival and lineage progression in this system. We show that ...
Garratt A N - - 2000
The signalling system comprising the ligand Neuregulin-1, and its receptors, ErbB2 and ErbB3, plays multiple and important roles in glial development. These include functions in early development of neural crest cells, in expansion of the Schwann cell precursor pool and in myelination. Neuregulin is one of the crucial axon-derived signals ...
Barski J J - - 2000
The cerebellar cortex and its sole output, the Purkinje cell, have been implicated in motor coordination, learning and cognitive functions. Therefore, the ability to generate Purkinje cell-specific mutations in physiologically relevant genes is of particular neurobiological interest. A suitable approach is the Cre/loxP strategy that allows temporally and spatially controlled ...
Hirata K - - 2000
Schwann cells participate in myelin phagocytosis in the early stage of Wallerian degeneration, prior to the recruitment of macrophages. This is the first report that Schwann cells induce heme oxygenase-1 (HO-1), a 32-kDa heat shock protein, only when they have transformed into myelin-phagocytosing cells from myelinating cells (days 2-3) immediately ...
Tipold A - - 2000
An unusual form of cerebellar granuloprival degeneration was observed in three male Coton de Tuléar puppies between 12 and 14 weeks of age from different litters showing progressive cerebellar signs beginning at 8 weeks after birth. Pathological examinations revealed a shrunken cerebellum. Histopathologically the granular cells were diminished or almost ...
Ristori G - - 2000
A case with stable multiple sclerosis (MS) and T cell responses which initially focused on peptide 16-38 of myelin basic protein (MBP) allowed us to investigate the dynamics of the MBP-specific T cell repertoire and its relationship with disease progression. Epitope mapping experiments and T cell receptor usage of MBP-reactive ...
Ruano D - - 2000
We analyzed the expression of native GABA(A) receptors in choline acetyltransferase and glutamic acid decarboxilase positive cells, from lamina IX of the lumbar region of rat spinal cord. More than one isoform of each subunit was detected within a single cell. The alpha3, alpha5, alpha1, beta3 and gamma2 subunit was ...
Kindler-Röhrborn A - - 2000
Contrary to the response of rats of the highly sensitive inbred strain BDIX, BDIV rats are resistant to the induction of malignant schwannomas by exposure to the alkylating N-nitroso carcinogen N-ethyl-N-nitrosourea (EtNU). In BDIX rats, a point mutation at nucleotide 2012 in the transmembrane region of the neu/erbB-2 gene has ...
Iwashita Y - - 2000
If Schwann cell transplantation is to be used as a therapy for demyelinating disease, it is important to know if the number of transplanted cells and their transplantation site affects the extent of remyelination. Primary Schwann cell cultures were obtained from neonatal rat sciatic nerve, purified, and expanded using bovine ...
Brancolini C - - 2000
Gas3/PMP22 is a tetraspan membrane protein highly expressed in myelinating Schwann cells. Point mutations in the gas3/PMP22 gene account for the dominant inherited peripheral neuropathies Charcot-Marie-Tooth type 1A disease (CMT1A) and Dejerine-Sottas syndrome (DSS). Gas3/PMP22 can regulate apoptosis and cell spreading in cultured cells. Gas3/PMP22 point mutations, which are responsible ...
Ghoumari A M - - 2000
Neuronal cell death is an essential feature of nervous system development and neurodegenerative diseases. Most Purkinje cells in murine cerebellar organotypic culture die when taken from 1-5-day-old mice (P1-P5), whereas they survive when taken before or after these ages. Using DNA gel electrophoresis, terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling (TUNEL) ...
Rosenbaum C - - 2000
Neurofibromatosis type 2 (NF2) is an autosomal dominant disease that is characterized mainly by schwannomas, as well as menigiomas and gliomas. The NF2 gene product merlin/schwannomin acts as a tumor suppressor. Schwann cells derived from NF2 schwannomas showed an enhanced proliferation rate, and electrophysological studies revealed larger K(+) outward currents ...
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