Biomedical subjects

P K Herman

Publications and source records attributed to P K Herman.

21 records · Page 2Linked to original sources

PubMed1988

Human myelin basic protein peptide 69-89: immunochemical features and use in immunoassays of cerebrospinal fluid.

The characteristics and heterogeneity of the myelin basic protein (MBP)-like material appearing in cerebrospinal fluid (CSF) after acute central nervous system (CNS) myelin injury are unresolved. Antigenic material containing an epitope in the carboxyl-terminal portion of human MBP peptide 45-89 (from the intact molecule of 170 residues) is a prominent species of the MBP-like material present. In an effort to define further the MBP-like material in CSF and to enhance its detection, a modified double-antibody radioimmunoassay has been developed using a radioligand of human MBP synthetic peptide 69-89. This assay is more sensitive with results paralleling those of previously used MBP assays for CNS myelin damage. Results with this assay provide additional confirmation of the presence of an epitope of MBP in the decapeptide of MBP 80-89 but in a conformation simulating that of intact MBP in CSF after CNS myelin injury. Unexpected buffer effects were noted to influence the immunochemical behavior of some of the small peptides of MBP.

Binding, Competitive↗

PubMed1988

Myelin basic protein and magnetic resonance imaging for diagnosing radiation myelopathy.

The identification of radiation myelopathy using biochemical assays and imaging techniques has not previously been accomplished but has clear clinical application. Measurement of myelin basic protein (MBP) in the cerebrospinal fluid (CSF) and visualization of the spinal cord using magnetic resonance imaging (MRI) gives a potentially accurate diagnosis of radiation myelopathy. Female New Zealand white rabbits were irradiated to the thoracic spinal cord with single doses of 15-45 Gy. Animals receiving higher doses (greater than or equal to 22 Gy) generally demonstrated an early paresis (4-8 weeks) that temporarily improved, and then progressed to complete paralysis by 14-18 weeks. MBP levels in the CSF became strikingly elevated to 100-1000 times the normal value. Subsequent, experiments in which rabbits were serially assessed for MBP levels demonstrated a transient elevation, which corresponded to the transient paresis, followed by dramatic elevations concurrent with the onset of paralysis. Magnetic resonance imaging (MRI) of the irradiated spinal cord showed a geographically distinct region of abnormality that corresponded to the radiation field. Histopathology demonstrated demyelination, focal astrocytosis, erythrodiapedesis, and perineuronal edema in the irradiated sections. It appears that MBP levels in the CSF reflect not only radiation-induced myelopathy but also transient demyelination, and that MRI may have the potential to indicate the region of damage.

Animals↗

PubMed1987

Myelin basic protein-specific RNA levels in interleukin-2-stimulated oligodendrocytes.

In the immune system, T- and B-cell proliferation, as well as B-cell immunoglobulin secretion, is induced by interleukin-2 (IL-2), a T-cell-derived lymphokine. IL-2 also influences the growth of glial cells, specifically, the proliferation and maturation of oligodendrocytes. Studies were conducted to investigate further IL-2-induced maturation of oligodendrocytes through its effect on the regulation of the myelin basic protein (MBP) gene. A cDNA probe specific for rat MBP and a double-antibody radioimmunoassay for MBP were used to quantitate MBP mRNA and protein levels in oligodendrocytes under different experimental conditions. We demonstrate that both MBP mRNA and protein levels are increased in IL-2-stimulated oligodendrocytes. MBP mRNA levels increase within 8 h after IL-2 stimulation, peak between 24 and 48 h, and then decline slightly. MBP protein levels increase 24 h after stimulation and peak at 72 h. MBP mRNA transcripts in the range of 2.0-2.4 kilobases are present in cultured rat oligodendrocytes, which are similar to the MBP mRNA transcripts detected in whole rat and mouse brain. These mRNA transcripts are specifically increased in quantity after oligodendrocyte stimulation with IL-2. These results suggest that one component of oligodendrocyte differentiation/maturation--MBP mRNA and protein expression--can be regulated in part by IL-2.

Animals↗