A pathology-MRI study of the short-T2 component in formalin-fixed multiple sclerosis brain.

Objective: To determine the pathologic basis of areas not exhibiting signal of the short-T2 component of the T2 relaxation distribution in MS, as studied in formalin-fixed brain.

Background: A myelin-specific MRI signal would be of great importance in assessing demyelination in patients with MS. Evidence indicates that the short-T2 (10 to 50 millisecond) component of the T2 relaxation distribution originates from water in myelin sheaths.

Cloning, chromosomal sublocalization of the human soluble aminopeptidase P gene (XPNPEP1) to 10q25.3 and conservation of the putative proton shuttle and metal ligand binding sites with XPNPEP2.

Human soluble ("cytosolic") aminopeptidase P (hsAmP) is an aminoacylprolyl hydrolase (EC 3.4.11.

Isolation of a cDNA encoding a taurine transporter in the human retinal pigment epithelium.

Reverse transcription-polymerase chain reaction (RT-PCR) was performed to amplify a cDNA encoding a taurine transporter in the human retinal pigment epithelium (HRPE). The coding region of a PCR product was found to be 1863 bp long, predicting a 620-amino acid protein (69,826 Da). This cDNA sequence is almost identical to those taurine transporters recently determined in the human thyroid and placenta: 12 and 1 base pair(s) different from the reported thyroid and placenta transporter clones, respectively.

In vivo phosphorylation of 2',3'-cyclic nucleotide 3'-phosphohydrolase (CNP): CNP in brain myelin is phosphorylated by forskolin- and phorbol ester-sensitive protein kinases.

2',3'-cyclic nucleotide 3'-phosphohydrolase (CNP) was phosphorylated in vivo, in brain slices and in a cell free system. Phosphoamino acid analysis of immunoprecipitated CNP labeled in vivo and in brain slices revealed phosphorylation of phosphoserine (94%) and phosphothreonine (5%) residues. Phosphorylation of CNP increased by 3-fold after brain slices were incubated with forskolin.

Oligodendrocyte reactions and cell proliferation markers in human demyelinating diseases.

We have carried out immunocytochemical reactions using antibodies to markers of oligodendrocytes, astrocytes, microglia and proliferating cells (PCNA) in sections of human brain in a variety of demyelinating conditions and human immunodeficiency virus (HIV) infection. In the acute phases of demyelinating diseases we found marked reactive changes in oligodendrocytes with hyperplasia and an increased cytoplasmic reaction using antibodies to enzymes involved in myelin formation. Proliferative responses were implied by the hyperplasia and the common finding of clusters of two or three adjacent oligodendrocytes at sites of acute myelin damage.

Mitochondrial schwannopathy and peripheral myelinopathy in a rabbit model of dideoxycytidine neurotoxicity.

Background: The reverse transcriptase inhibitor, 2',3'-dideoxycytidine (ddC), causes a dose-limiting peripheral neuropathy in humans, the mechanism of which is unknown. Rabbits given ddC develop peripheral myelinopathy and axonopathy, but it has not been determined if either the myelin or axonal changes are primary or if they occur concurrently.

Experimental Design: To characterize sequential development of the ddC-induced neuropathy, 40 rabbits were given either vehicle or ddC by oral intubation at a dose of 35 mg/kg per day for 24 weeks.

Chromosomal mapping of the human CNP gene using a meiotic crossover DNA panel, PCR, and allele-specific probes.

The human 2',3'-cyclic nucleotide 3'-phosphohydrolase (CNP) gene is located on chromosome 17, as determined by PCR of somatic cell hybrid DNA panels and confirmed using a mouse-human hybrid containing only human chromosome 17. A polymorphic site (C, T) was previously described at nucleotide 1215 within the most 3' intron of the gene. Nested PCR primer pairs were designed to amplify across this site, and PCR products were hybridized to end-labeled allele-specific probes.

Assignment of the human 2',3'-cyclic nucleotide 3'-phosphohydrolase gene to chromosome 17.

2',3'-Cyclic nucleotide 3'-phosphohydrolase (CNP) has been used as a general oligodendrocyte and Schwann cell marker enzyme within the nervous system and has been the intense target of a number of recent studies. In this report, we determined the chromosomal localization of the human CNP gene using PCR on two somatic cell DNA panels. PCR amplification, using four primer pairs across an intron, confirms that the CNP gene is localized to chromosome 17.

2',3'cyclic nucleotide-3'-phosphodiesterase in peripheral nerve myelin is phosphorylated by a phorbol ester-sensitive protein kinase.

2',3' cyclic nucleotide-3'-phosphodiesterase (CNP) is phosphorylated in the peripheral nervous system after immunoprecipitation of myelin proteins radiolabeled in vivo, in nerve slices and in a cell-free system. Only radiolabeled phosphoserine was detected after partial acid hydrolysis of immunoprecipitated CNP. Two major phosphopeptides were resolved by two dimensional electrophoresis-chromatography after digestion with trypsin of CNP phosphorylated in the nerve slices.

2',3'-cyclic nucleotide-3'-phosphodiesterase in the central nervous system is fatty-acylated by thioester linkage.

2',3'-Cyclic nucleotide-3'-phosphodiesterase (CNP1 and CNP2 with Mr of 46,000 and 48,000, respectively) is the major enzyme of central nervous system myelin. It is associated with oligodendroglial plasma membrane and uncompacted myelin (myelin-like fraction), which are in contact with glial cytoplasm. Proteins of the myelin-like fraction were labeled with [3H]palmitic acid in brain slices from 17-day-old rats and immunoprecipitated with anti-CNP antiserum.

Binding of a Staphylococcus aureus bone pathogen to type I collagen.

We contrasted the collagen-binding potential of the experimental osteomyelitis pathogen, Staphylococcus aureus strain SMH, to several other strains. These included Cowan 1 (binder), Wood 46 (non-binder) and six capsular variants. These measurements were made using an 125I-collagen binding assay.

Multiple sclerosis. Oligodendrocyte proliferation and differentiation in fresh lesions.

Fresh lesions in the brain and spinal cord of patients with multiple sclerosis who died shortly after the onset of symptoms were examined immunocytochemically for myelin and oligodendrocyte antigens that are known to be sequentially expressed during normal development. Cells with oligodendrocyte-like morphology that appear in large numbers throughout fresh lesions after acute myelin breakdown and before new myelin formation were found to express galactocerebroside, carbonic anhydrase, and 2',3'-cyclic nucleotide 3'-phosphohydrolase but not myelin-associated glycoprotein or myelin basic protein. They also exhibit intense surface reactivity for a carbohydrate epitope associated with the family of cell adhesion molecules recognized by the monoclonal antibody HNK-1.

2',3'-cyclic nucleotide 3'-phosphodiesterase, an oligodendrocyte-Schwann cell and myelin-associated enzyme of the nervous system.

2',3'-Cyclic nucleotide 3'-phosphohydrolase (E.C. 3.

Differential expression of galactocerebroside, myelin basic protein, and 2',3'-cyclic nucleotide 3'-phosphohydrolase during development of oligodendrocytes in vitro.

This paper describes the differential expression and localization of myelin components within membrane sheets produced by oligodendrocytes in vitro. In double-labeling experiments using antibodies to the myelin antigens 2',3'-cyclic nucleotide 3'-phosphohydrolase (CNP) and galactocerebroside (GC), the two antigens were coexpressed in at least 95% of oligodendrocytes at all ages examined. A small population of relatively undifferentiated cells expressed one antigen before the other.

Oligodendrocyte substratum adhesion modulates expression of adenylate cyclase-linked receptors.

The molecular mechanisms of myelin formation/reformation in the central nervous system are unknown. In previous work we have demonstrated that mature oligodendrocytes (OLG) respond to a signal(s), elicited by their adhesion to a substratum, by turning on a myelinogenic metabolism. Events occurring within 24 hr of adhesion include generation of diacylglycerol, activation of protein kinase C, phosphorylation of myelin basic protein, and enhanced synthesis of myelin lipids and proteins.

Monoclonal antibody production to human and bovine 2':3'-cyclic nucleotide 3'-phosphodiesterase (CNPase): high-specificity recognition in whole brain acetone powders and conservation of sequence between CNP1 and CNP2.

Monoclonal antibodies against human and bovine 2':3'-cyclic nucleotide 3'-phosphodiesterase (CNPase) were generated by fusing FOX-NY myeloma cells with spleen cells from RBF/Dn mice previously immunized with the purified brain antigens. The enzyme isolated from bovine brain was quite basic, with an isoelectric point of 9.71 and both the bovine and human enzymes consisted of a closely spaced doublet at approximately 44 and 46 kDa on SDS-PAGE.

Inhibition of bovine and human brain 2':3'-cyclic nucleotide 3'-phosphodiesterase by heparin and polyribonucleotides and evidence for an associated 5'-polynucleotide kinase activity.

The present paper establishes a 5'-polynucleotide kinase activity associated with the bovine and human brain enzyme 2':3'-cyclic nucleotide 3'-phosphodiesterase (EC 3.1.4.

Differential expression of 2':3'-cyclic nucleotide 3'-phosphodiesterase in cultured central, peripheral, and extraneural cells.

The relative levels of the central nervous system myelin marker enzyme 2':3'-cyclic nucleotide 3'-phosphodiesterase (EC 3.1.4.

Induction of myelin components: cyclic AMP increases the synthesis rate of 2',3'-cyclic nucleotide 3'-phosphohydrolase in C6 glioma cells.

In an effort to determine the factors that stimulate myelin synthesis, we investigated the mechanism by which dibutyryl cyclic AMP induces the activity of the myelin enzyme, 2',3'-cyclic nucleotide 3'-phosphohydrolase (CNP; EC 3.1.4.

Localization of 2',3'-cyclic nucleotide 3'-phosphodiesterase on cultured Schwann cells.

Primary cultures of Schwann cells were labeled by indirect immunofluorescence using an antibody directed against 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNPase). Schwann cells which had been maintained in culture for 8 weeks were labeled with this antibody. Immunoblot analysis of Schwann cell homogenates revealed a single band with a molecular weight of 54,000 daltons which corresponded to a single immunoreactive polypeptide present in myelin prepared from rat sciatic nerve.

The distribution of 2':3'-cyclic nucleotide 3'-phosphodiesterase (CNP) in the CNS of normal (+/+) and shiverer (Shi/Shi) mice.

Immunohistochemical techniques were utilized to localize the putative myelin enzyme 2':3'-cyclic nucleotide 3'-phosphodiesterase (CNP) in the central nervous system (CNS) of normal (+/+) and Shiverer (Shi/Shi) mice (Mus musculus). CNP appeared to be only associated with myelinated nerve fibers in the CNS (corpus callosum, subcortical white matter, caudate nucleus, cerebellum and medulla oblongata) of +/+ mice. However, little or no immunostaining was observed in the same regions of the CNS of Shi/Shi mice, although these mice have normal levels of a CNS CNP activity.

An immunochemical investigation of 2':3'-cyclic nucleotide 3'-phosphodiesterase (CNP) in bovine cerebrum and human oligodendroglioma.

Bovine cerebrum, including the corpus callosum, and a human oligodendroglioma were investigated by an immunohistochemical technique to determine the distribution of 2':3'-cyclic nucleotide 3'-phosphodiesterase (CNP). Also, three human oligodendrogliomas (ODG) were characterized by an immunoblot procedure to identify a protein(s) with cross-reacting determinants to CNP and assayed for CNP activity. CNP was localized to oligodendrocytes in the corpus callosum and subcortical white matter and gray matter.

Immunofluorescence demonstration of 2':3'-cyclic-nucleotide 3'-phosphodiesterase in cultured oligodendrocytes of mouse, rat, calf and human.

Previous biochemical studies have shown that high enzyme activity of 2':3'-cyclic-nucleotide 3'-phosphodiesterase (CNP) is found in isolated myelin and oligodendrocytes. We report here the specific and intense immunofluorescence staining of cultured oligodendrocytes obtained from the brains of mouse, rat, calf and human by rabbit antiserum specific for purified bovine CNP. Astrocytes and fibroblasts present in the cultures were negative for the immunostaining.