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Biomedical subjects

D E Pleasure

Publications and source records attributed to D E Pleasure.

At least 37 records · Page 2Linked to original sources
PubMed1985

Transfer of experimental allergic neuritis with P2-reactive T-cell lines.

Experimental allergic neuritis (EAN) was induced in normal Lewis rats by systemic passive transfer of T-cell lines responding to P2 protein. These cells had predominantly helper phenotype and could induce EAN within 7 days following adoptive transfer. There was no anti-P2 antibody response in the recipients of the P2-reactive cells recovered from donors with high anti-P2 antibody levels. This study provides direct evidence that T cells are important for the induction of EAN. Furthermore, there was no evidence of a pathogenic role for anti-P2 antibody in passive EAN.

Animals↗
PubMed1984

Generation and biological properties of a monoclonal antibody to galactocerebroside.

Galactocerebroside ( GalC ) is a major glycolipid of myelin and myelin-forming cells. We have generated a mouse IgM monoclonal antibody to GalC (M-anti- GalC ) which bound only to oligodendrocytes in rat and bovine central nervous system cultures as assessed by immunofluorescence. Double staining with rabbit anti-glial fibrillary acidic protein and anti-fibronectin antisera revealed no binding of M-anti- GalC to astrocytes or fibroblasts. Schwann cells, but not fibroblasts, were stained in short-term cultures of rat Schwann cells. M-anti- GalC exhibited in vitro cytotoxicity to rat and bovine oligodendrocytes in the presence of complement. This monoclonal antibody with its monospecificity, consistent titer, and capacity to induce cell lysis should be useful for in vitro and in vivo investigations concerning myelination and demyelination.

Animals↗
PubMed1984

The role of myelin P2 protein in the production of experimental allergic neuritis.

Myelin P2 protein has been proposed as the primary antigen in whole myelin-induced experimental allergic neuritis (EAN). We investigated the neuritogenic properties of P2 by sensitizing Lewis rats with complete Freund's adjuvant (CFA) containing P2, P2 plus phosphatidyl serine, or whole myelin containing an equivalent amount of P2. Animals were examined using a battery of clinical, electrophysiological, immunological, and morphological methods. Myelin-immunized rats developed the characteristic features of EAN. P2-sensitized rats developed a similar but much less intense disorder. When rats were sensitized with P2 in the presence of phosphatidyl serine, however, they developed radiculoneuropathy that was indistinguishable from myelin-induced EAN. Inoculation with phosphatidyl serine plus complete Freund's adjuvant or complete Freund's adjuvant alone had no detectable effect on peripheral nerves. These studies demonstrate that sensitization of rats with a single myelin antigen, P2 protein, is sufficient to induce the clinical, electrophysiological, and neuropathological features of EAN.

Animals↗
PubMed1984

Long-term cultures of human adult Schwann cells isolated from autopsy materials.

Enriched populations of adult human Schwann cells were obtained from trigeminal ganglia and roots of autopsy material. The cells, isolated by enzymatic procedure, were seeded on rat tail collagen-coated coverslips. Subcultures were established several weeks later, and secondary cells were grown on polylysine-coated coverslips and maintained in vitro for as long as 5 months. The Schwann cells in culture displayed the same light- and electron-microscopic features and arrangement as those cells observed in vivo. The addition of bovine pituitary glial growth factor in the medium induced a 3-5-fold increase in Schwann cell division.

Adult↗
PubMed1984

Erythrocyte calcium transport in myotonic and facioscapulohumeral muscular dystrophy.

We studied calcium transport in inside-out erythrocyte vesicles from patients with myotonic or facioscapulohumeral dystrophy and age- and sex-matched controls. No significant difference was noted in the affinity of the transporter for calcium or the maximum reaction velocity. Under identical conditions, we previously found that Duchenne dystrophy membranes differed from controls in affinity for calcium and maximum velocity. The results reported here imply that the abnormality in Duchenne dystrophy is specific and not an abnormality found in all forms of dystrophy.

Adult↗
PubMed1983

Cultured human and rat oligodendrocytes and rat Schwann cells do not have immune response gene associated antigen (Ia) on their surface.

In order to determine if oligodendrocytes or Schwann cells had surface immune response gene associated antigen (Ia), we studied the binding of: (a) mouse monoclonal antibodies to rat Ia, to cultures of rat oligodendrocytes and Schwann cells; and, (b) mouse monoclonal antibodies to human Ia, to cultures of human oligodendrocytes employing radioimmunoassay and indirect immunofluorescence. Cells were identified using phenotypic markers; rabbit anti-galactocerebroside (GalC) for oligodendrocytes; rabbit anti-GalC and rabbit anti-Schwann cell for Schwann cells; rabbit anti-glial fibrillary acidic protein for astrocytes; rabbit anti-fibronectin for fibro-blasts and leptomeningeal cells, and the capacity to ingest latex particles for macrophage-microglia. Ia could not be detected on the surface of oligodendrocytes, Schwann cells, astrocytes, fibroblasts, or leptomeningeal cells. A small number of latex ingesting cells bound anti-Ia even after blocking of surface Fc receptors.

Aged↗
PubMed1983

Culture of purified rat astrocytes in serum-free medium supplemented with mitogen.

We have obtained a highly purified astrocyte population in cultures originating from neonatal (2-5 days) rat cerebrum by use of the selection process provided by a serum-free chemically defined medium (DM). The addition of a glial growth factor isolated from bovine pituitary glands to DM induced in these astrocyte cultures both a stimulation of astrocytic proliferation and a morphological transformation of the astrocytes from flat fibroblastic form to multipolar stellate form.

Animals↗
PubMed1983

Absence of expression of OKT8 antigen on cultured human, calf and rat oligodendrocytes.

Monoclonal antibodies which recognize human suppressor T cells (OKT8) have been reported by Oger and co-workers to bind to cultured sheep oligodendrocytes. These authors speculated that an immune response directed at determinants shared by suppressor lymphocytes and oligodendrocytes could explain the decrease in both circulating blood suppressor T cells and oligodendrocytes in patients with multiple sclerosis. In view of the vital issue of potential cross-reactivity between oligodendrocytes and lymphocytes, we studied the binding of viable cultured calf, rat and human oligodendrocytes using monoclonal antibodies to human T cells and monocytes. We report here that we were unable to confirm the presence of shared determinants among oligodendrocytes and any leukocytes, including human T cells or monocytes. As the reported observations of lymphocyte-oligodendrocyte shared determinants could not be identified in three other species, including man, we found no evidence to support the hypothesis that such shared determinants are of importance in the pathogenesis of multiple sclerosis.

Animals↗
PubMed1983

P2 protein-induced experimental allergic neuritis. An ultrastructural study.

Experimental allergic neuritis (EAN) was induced in 2 groups of inbred Lewis rats by sensitization with P2 protein and peripheral nervous system (PNS) myelin, both purified from bovine intradural roots. Light- and electronmicroscopic study of P2-induced EAN revealed demyelinative lesions in spinal ganglia and root nerves and less frequently in peripheral nerves and root entry zones. Both small and large myelinated fibers were demyelinated, contradictory to the reported selective binding of anti-P2 antibodies to myelin of large fibers. The early lesions were characterised by perivenular lymphocytic infiltration, and subsequent "dissolution" of myelin sheath was associated with invasive of phagocytic cells. The distribution of demyelinative lesions and patterns of demyelination resembled those of PNS myelin-induced EAN except that the disease was milder and dissolution of myelin and intramyelinic edema were more frequently found in P2-induced EAN. The abundance of demyelination in P2-induced EAN strikes contrast to the scarcity of myelin change in experimental allergic encephalomyelitis (EAE) induced by myelin basic protein immunization.

Animals↗
PubMed1983

Long-term culture of human oligodendrocytes. Isolation, growth and identification.

Oligodendrocytes were isolated from adult human brains obtained at autopsy. The cells were prepared by Percoll density gradient centrifugation, seeded on plastic coverslips and were cultured for a period up to 6 months. The oligodendrocytes in culture expressed cell-type specific markers, galactocerebroside and myelin basic protein and revealed the ultrastructure of mature oligodendrocytes.

Adult↗
PubMed1983

Immune reactions to P2 protein in human inflammatory demyelinative neuropathies.

The significance of immune reactions against peripheral nervous system antigens in the human inflammatory polyneuropathies is still uncertain. Using a very sensitive assay, we found greatly increased levels of anti-P2 antibodies in sera of animals with experimental allergic neuritis (EAN) but no increases in humans with acute Guillain-Barré syndrome (GBS), chronic relapsing polyneuritis (CRIP), axonal neuropathy, or normals. P2 protein and CNS basic protein did not induce any increased proliferation in lymphocytes of GBS or CRIP patients. We conclude that P2 and BP appear unlikely to be targets for humoral or cellular immune reactivity in GBS or CRIP.

Adolescent↗
PubMed1982

Antibodies to P2 and P1 myelin antigens in experimental allergic neuritis and allergic encephalomyelitis.

We confirmed earlier observations that experimental allergic neuritis (EAN) in Lewis rats induced by injection of bovine peripheral nerve myelin in complete Freund's adjuvant is not accompanied by development of experimental allergic encephalomyelitis. However, sera of these animals contained elevated titers of antibodies against central nervous system myelin basic protein (BP), likely induced by peripheral nerve P1 protein. Anti-BP antibodies were not seen in sera of rats with EAN induced by peripheral nerve P2 protein. Lack of encephalogenicity of bovine myelin in Lewis rats does not reflect simply lack of immune responses induced against BP.

Animals↗
PubMed1981

Long term culture of bovine oligodendroglia isolated with a Percoll gradient.

Oligodendroglia were isolated from calf central nervous system (CNS) white matter by trypsinization in phosphate buffered saline and separation by centrifugation through Percoll. Using antisera to phenotypic markers and double labelling experiments we were able to identify essentially all cells in the cultures. The cells obtained were: (1) viable; (2) had intact plasma membranes and well preserved organelles, ribosomes and mitochondria; and (3) were greater than or equal to 95% oligodendroglia 16-20 h after isolation as determined by ability to bind antigalactocerebroside antibodies (anti-GalC). Oligodendroglia could be cultured for several weeks to months. Oligodendroglia established and maintained processes which bound anti-GalC. Myelin basic protein could be demonstrated in the cytoplasm of 40-60% of oligodendroglia cell bodies but not in the processes.

Animals↗
PubMed1981

Radioimmunoassay for detection of anti-oligodendrocyte antibodies.

A solid phase radioimmunoassay (RIA) for detection and quantitation of rabbit anti-oligodendrocyte antibody has been developed using bovine oligodendroglia preparation. The assay is simple, rapid, reproducible and economical. It is approximately 150 x as sensitive as immunofluorescence. Specificity has been established by using different bovine tissue antigens as substrate and absorption studies. This assay represents a potentially powerful tool for the detection and quantitation of anti-oligodendroglial antibodies and oligodendroglial antigens in serum and CSF of man and experimental animals.

Animals↗
PubMed1981

Enrichment of Schwann cell cultures from neonatal rat sciatic nerve by differential adhesion.

A novel method of Schwann cell purification from neonatal rat sciatic nerve has been developed using differential adhesion. After enzymatic and mechanical dissociation, the cell digest is allowed to settle on polylysine-coated glass coverslips for 30 min with intermittent shaking. After an 18-h incubation, bipolar cells comprise greater than 95% of the non-adherent population. Indirect immunofluorescence with the cell-specific markers rabbit anti-galactocerebroside and rabbit anti-bovine-P-2 basic protein antiserum confirmed light microscopic identification of these bipolar cells as Schwann cells. Rabbit anti-human fibronectin specifically labeled fibroblasts which comprised less than 5% of the cell population, but did not bind to Schwann cells. Schwann cells isolated by differential adhesion were injected into a rabbit. When absorbed with cultured rat skin fibroblasts, serum from this rabbit specifically surface labeled greater than 99% of the bipolar and round cells after 18 h and 5 days in vitro and also labeled Schwann cells in fetal rat dorsal root ganglia cultures, but not fibroblasts or neurons.

Animals↗
PubMed1980

Calcium transport in human inside-out erythrocyte vesicles.

Inside-out vesicles from human erythrocytes were used to study the kinetics of calcium transport. The amounts of total ATP, MgCl2, and CaCl2 required to yield particular concentrations of MgATP2-, free Mg2+, and free Ca2+ were determined mathematically, and the final concentration of free Ca2+ was confirmed using the calcium indicator dye arsenazo III. Calcium accumulation was linear for 40 min in the presence of ATP and for at least 60 min in the presence of ATP and oxalate. When the calcium ionophore A-23187 was added at the end of an uptake experiment, 95% of accumulated calcium was released. There was a single affinity for calcium with a Km of 3.4 +/- 0.4 microM. Rduced glutathione in the assay medium increased the Vmax but did not alter the Km. The optimal pH was 6.9 to 7.3, and the optimal temperature was 40 degrees C with an Ea of 14.3 kcal/mol. The dependence of calcium accumulation on [MgATP2-] and [ATP4-] could not be measured separately in this assay system. At half-maximal transport rate [MgATP2-] = 1.0 MM and [ATP4-] = 0.1 mM. The data suggest a complex kinetic mechanism.

Adenosine Triphosphate↗
PubMed1980

Antisera to bovine oligodendroglia raised in guinea pigs bind to surface of rat oligodendroglia and Schwann cells.

Antisera against bulk isolated bovine oligodendrocytes was raised in 2 guinea pigs (GPaBO). The sera bound only to surface of rat oligodendrocytes in dissociated rat corpus callosum and cerebellar cultures and only to surface of Schwann cells in primary and secondary sciatic nerve and dorsal root ganglia cultures as determined by indirect immunofluorescence. No cells in muscle or retinal cultures bound the guinea pig antisera. The shared antigen does not seem to be either galactocerebroside (GalC) or a myelin basic protein. GPaBO can serve as a useful marker in double-label experiments to identify oligodendrocytes and Schwann cells in dissociated cultures.

Animals↗