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T Inuzuka

Publications and source records attributed to T Inuzuka.

At least 73 records · Page 4Linked to original sources
PubMed1991

Structure of mouse myelin-associated glycoprotein gene.

The mouse myelin-associated glycoprotein gene was isolated from a mouse gene library. This gene was split into 13 exons distributed about 15 kb in length. Each extracellular immunoglobulin-related domain was encoded by a single exon, and RNA splicing between those exons occurred between the first and second nucleotides of the junctional codon, the features of which are conserved in most of the genes of the immunoglobulin superfamily. The sequence of the 5'-flanking region appeared to have some regions homologous to other myelin proteins, which suggested that they were possible cis-elements for specific expression of oligodendrocytes.

Animals↗
PubMed1991

Distribution of P0 protein and the myelin-associated glycoprotein in peripheral nerves from Trembler mice.

The Trembler mouse has a dysymelination of peripheral nerves that includes hypomyelination, failure of myelin compaction, and demyelination/remyelination. We have localized the myelin proteins P0 and myelin associated glycoprotein in Trembler peripheral nerve and correlated their distributions with the ultrastructure of myelin internodes. Immunocytochemically, myelin-associated glycoprotein was localized in Schwann cell periaxonal membranes, Schmidt-Lanterman incisures, paranodal loops, and internal and external mesaxons. P0 staining was located over compact myelin and regions of Schwann cell cytoplasm rich in Golgi membranes. An unusual abundance of small, P0-stained, Golgi-related vesicles was found in some Schwann cells. P0 protein was also detected in multiple spiral wraps of myelin-associated glycoprotein-positive mesaxon membranes. At some sites the periodicity of the myelin membranes was intermediate to that found in mesaxon membranes and compact myelin. The distance between apposing extracellular leaflets was similar to that found in mesaxon membranes, while the cytoplasmic leaflets were fused but twice as thick as normal major dense lines. These intermediate membranes were stained by P0 and myelin-associated glycoprotein antiserum. These studies suggest that altered transport and/or translocation of P0 and myelin-associated glycoprotein results in defective myelin compaction in Trembler peripheral nerve.

Animals↗
PubMed1991

Creutzfeldt-Jakob disease in a patient with a cadaveric dural graft.

We report a 26-year-old woman with Creutzfeldt-Jakob disease (CJD) who had received cadaveric dural material 33 months before the onset of neurologic symptoms. This is the fourth case in which a dural graft was the putative source of the CJD agent. All four cases had the grafting before changes in the sterilization procedure adopted in 1987 to inactivate the CJD agent.

Adult↗
PubMed1990

Suppressive effect of E-64c on ischemic degradation of cerebral proteins following occlusion of the middle cerebral artery in rats.

Microtubule-associated protein 2 (MAP2) levels in the left cerebral hemisphere decreased significantly 3 days after occlusion of the left middle cerebral artery in rats to 29 +/- 16.3% of control levels. Since MAP2 is one of the substrates of calpain, E-64c, a synthetic calpain inhibitor, was administered at a dose of 400 mg/kg twice a day for 3 days, with the first dose being given before the production of ischemia. This depletion was significantly inhibited in vivo by E-64c (P less than 0.05) to increase MAP2 levels to 55 +/- 25.7% of control levels. E-64c had no significant effect on the ischemia-induced depletion of myelin-associated glycoprotein. Sham-operated rats were used as controls. Our results suggest that calpain is partially involved in the degradation of MAP2, and that the use of calpain inhibitors can be a useful clinical approach to cerebral ischemia.

Animals↗
PubMed1990

The large isoform of myelin-associated glycoprotein is scarcely expressed in the quaking mouse brain.

Two polypeptide isoforms of myelin-associated glycoprotein (MAG) with molecular masses of 72 and 67 kDa are produced by alternative splicing of the exon 12 portion. Our previous work has demonstrated that in the quaking mouse brain this alternative splicing is lacking and that the mRNA coding the large MAG isoform (L-MAG) is scarcely expressed, whereas that of small MAG isoform (S-MAG) is overexpressed. In the present study, we prepared antisera specific to the S-MAG and L-MAG amino acid residues, respectively. Immunoblots showed that the L-MAG band was scarcely detectable in the quaking mouse brain, whereas the S-MAG band had an apparently higher molecular mass than in the normal control. Our immunohistochemical study also showed that L-MAG was scarcely stained in the quaking mouse brain. These results seemed to reflect a reduction in content of L-MAG mRNA and abnormal glycosylation in the quaking mouse brain.

Animals↗
PubMed1990

Changes in the concentrations of cerebral proteins following occlusion of the middle cerebral artery in rats.

Using an immunoblotting technique, we investigated changes in the concentrations of microtubule-associated protein 2, 200-kDa neurofilament, tubulin, myelin-associated glycoprotein, and 2':3'-cyclic nucleotide 3'-phosphodiesterase in the brains of 40 rats following occlusion of the left middle cerebral artery or sham operation. Compared with those 4 hours after surgery, concentrations of all proteins decreased significantly in the left hemisphere 3 days after surgery (p less than 0.01). Microtubule-associated protein 2 was the most susceptible to ischemia, and its mean +/- SEM concentration decreased to 23 +/- 9.4% of that in concurrent sham-operated controls. Degradation products of microtubule-associated protein 2 and myelin-associated glycoprotein were detected on the blots. Furthermore, in the contralateral hemisphere (where calpain might be activated), concentrations of these two proteins decreased to 57 +/- 12.0% and 83 +/- 4.3% of those in concurrent sham-operated controls, respectively, 3 days after surgery. Changes in the concentrations of cerebral proteins in the contralateral hemisphere are important for understanding clinical symptoms not attributable solely to the ipsilateral lesion following a focal cerebral stroke.

Animals↗
PubMed1989

cDNA cloning of mouse myelin-associated glycoprotein: a novel alternative splicing pattern.

The structures of three forms of mouse myelin-associated glycoprotein mRNAs were determined from full-length cDNA clones. Two forms of mRNAs have been reported to be different by alternate inclusion of exon 2 and 12 in rat brain. One of the three forms of clones obtained here appeared to be a novel mRNA which lacked both the exon 2 and 12 portions, although others were identical splicing patterns to those of rat. Northern blot analysis using specific probes to mRNAs with or without the exon 2 portion in normal and quaking mouse confirmed that the splicing of exon 2 and 12 occurred independently.

Amino Acid Sequence↗
PubMed1989

Antibodies to human spinal cord proteins in sera from patients with motor neuron disease and other neurological diseases.

Antibodies to human spinal-cord proteins in sera from patients with motor neuron disease (MND) and other neurological diseases were detected by the immunoblotting method. IgG in serum from a patient with amyotrophic lateral sclerosis reacted with insoluble proteins in the crude nuclear subfraction but the IgG in serum from other patients reacted with soluble proteins. The molecular weights of the antigens on the blots differed among the cases. The significance of the antibodies to neural tissue in sera from MND remains unknown. The etiology of MND is thought to be heterogenous and some types of MND may be closely related to humoral immunity.

Antibodies↗
PubMed1988

Developmentally regulated alternative splicing of brain myelin-associated glycoprotein mRNA is lacking in the quaking mouse.

Evidence is presented that expression of the two myelin-associated glycoprotein mRNAs is developmentally regulated in mouse brain. In quaking mouse, the mRNA without a 45-nucleotide exon portion was scarcely expressed throughout development. We conclude that the mechanism of splicing out the 45-nucleotide exon portion is lacking in quaking mouse.

Amino Acid Sequence↗
PubMed1988

Analysis of myelin proteins in sympathetic peripheral nerve of adult rats.

Biochemical analyses of myelin proteins in rat sympathetic peripheral nerve were correlated with morphological observations. Myelin proteins in superior cervical ganglia (SCG) and the paravertebral (thoraco-lumbar) chain of ganglia were quantitated by immunoassays and examined qualitatively by Western blotting. The results were compared to those obtained on sciatic nerves from the same animals. In rats aged one year, the concentrations of PO glycoprotein and myelin basic protein (MBP) in SCG were about 1% of those in sciatic nerve, consistent with the relatively low numbers of myelinated fibers in sympathetic nerve. The relative concentration of myelin-associated glycoprotein (MAG) was higher, being 6.7% of that in sciatic nerve. The latter finding is probably due to the greater proportion of MAG-containing membranes (periaxonal, paranodal, and Schmitt-Lanterman incisures) in myelinated fibers of the SCG, in which the internodes are both short and thinly myelinated. The proportion of the 21 kDa, 18 kDa and 17 kDa forms of MBP relative to the 14 kDa form was much higher in SCG than in sciatic nerve, probably reflecting the fact that myelin formation continues actively during adult life in the ganglia, whereas the deposition of myelin is complete at a much earlier age in somatic nerves. The levels of myelin proteins were 2- to 3-fold higher in the paravertebral chain ganglia. These studies indicate that quantitation of myelin proteins in sparsely myelinated sympathetic nerve tissue is feasible and provide a baseline for further studies on the control of myelination in sympathetic nerve during adult life.

Animals↗
PubMed1988

Suppressive effect of camostat mesilate (FOY 305) on acute experimental allergic encephalomyelitis (EAE).

Camostat mesilate (FOY305), a synthetic serine protease inhibitor and has been developed as a drug for pancreatitis, is effective in suppressing acute experimental allergic encephalomyelitis in Lewis rats. Loss of weight, clinical score and yield of myelin protein from brain stem were improved by daily injection of FOY305 compared with saline from day 6 after inoculation with homogenate of guinea pig spinal cord. A significant decrease of yield of myelin has been shown here for the first time in acute EAE in Lewis rat. This is in accord with myelin breakdown demonstrated morphologically. Our study also demonstrates a significant improvement of yield of myelin protein by FOY305. Our results suggest the possibility of a clinical application of this protease inhibitor for human demyelinating diseases such as multiple sclerosis.

Animals↗
PubMed1988

IgM binding to sialosyllactosaminylparagloboside in a patient with polyradiculoneuropathy due to Mycoplasma pneumoniae infection.

IgM in serum without paraprotein in a patient with polyradiculoneuropathy due to a Mycoplasma pneumoniae infection reacted specifically with a ganglioside, sialosyllactosaminylparagroboside (SLPG), in a human peripheral nerve on a thin-layer chromatogram plate by an immunostaining technique. This finding suggests the possibility that anti-SLPG antibody in the patient's serum may play a role in the pathogenesis of neuropathy.

Female↗
PubMed1987

Murine monoclonal antibodies to the myelin-associated glycoprotein (MAG) recognize Leu-7-reactive molecules on human mononuclear cells.

It is known that the antibody to human myelin-associated glycoprotein (MAG) reacts with a subset of human mononuclear cells (MNC) mediating a natural killer (NK) activity. The properties of the target molecule of the anti-MAG antibody, however, have not yet been elucidated. Three (GC-J4, MC-P2, and MC-P4) of five murine monoclonal antibodies (mAb) to MAG bound to human MNC. Moreover, MC-P2 and MC-P4 inhibited the binding of 125I-labeled anti-Leu-7 to MNC in a dose-dependent fashion. Conversely, anti-Leu-7 inhibited the binding of MC-P2 and MC-P4 to MNC, but did not inhibit the binding of GC-J4. Therefore, it is possible that MC-P2 and MC-P4 bind directly to or close to the Leu-7 epitope, and that GC-J4 binds to the epitope which is distinct from the Leu-7 epitope. The electrophoretic patterns of immunoprecipitates with GC-J4, MC-P2 and anti-Leu-7 from detergent lysates of surface-labeled human MNC were very similar. The target molecules of anti-Leu-7 and anti-MAG mAb have apparent m.w. of 205, 170, 150, 135, 110, 85, 65, and 55 kDa. All of the molecules precipitated by these mAb are monomeric or noncovalently associated proteins, because the electrophoretic mobilities of the proteins remained unchanged whether the samples were reduced or not. MC-P4 may have a higher affinity for the 65 kDa molecule than the other mAb, and precipitates the 58 kDa molecule as well. Therefore, the fine antigenic specificity of MC-P4 is slightly different from those of anti-Leu-7 or MC-P2. The implication of these results is that mAb, whose specificity is directed to the carbohydrate part of human MAG, reacts with the Leu-7 reactive molecules on human MNC, and that at least two epitopes detected by anti-MAG mAb coexist on the surface molecules with various apparent m.w.

Animals↗
PubMed1987

Developmental changes of myelin-associated glycoprotein in rat brain: study on experimental hyperphenylalaninemia.

We examined developmental changes of myelin-associated glycoprotein (MAG), basic protein (BP), and proteolipid protein (PLP) in central nervous system myelin isolated from experimental hyperphenylalaninemic rats (PKU rats) and controls. Higher amounts of MAG, including high-molecular-weight MAG in myelin, were found in 12- to 21-day-old control rats than in adult rats. MAG in developing myelin was at a maximum in 18-day-old rats and began to decrease in 21-day-old rats, while PLP and BP in developing myelin increased at these developmental stages. The level of high-molecular-weight MAG decreased in myelin prepared from 21-day-old rats. These results suggest that the decreasing high-molecular-weight MAG is important for compaction of myelin in the early stage of myelination. In myelin from 12- to 18-day-old PKU rats, the ratio of each protein such as MAG, PLP, or BP to that of control was about 0.5 at 12 days, and increased to almost 1.0 at 18 days. The myelination seems to be initially delayed but to be close to that of controls in PKU rats about 18 days old.

Animals↗
PubMed1987

Shared carbohydrate antigenic determinant between the myelin-associated glycoprotein (MAG) and lung cancers. An immunohistochemical study by an anti-MAG IgM monoclonal antibody.

An immunochemical study has shown that monoclonal anti-myelin-associated glycoprotein (MAG) antibodies identify some membrane glycoproteins from cell lines of small cell lung cancer. We investigated immunohistochemically 85 specimens of lung cancer from resection and autopsy using one of the monoclonal antibodies against MAG. One adenocarcinoma was highly reactive with the anti-MAG antibody, and in three small cell carcinomas immunostained tumor cells were distributed either singly or in occasional small clusters. These results show that a shared antigenic determinant with MAG appears on the tumor cells. MAG is believed to play the role of antigen in the development of carcinomatous polyneuropathy, and contributes to cancer development by its reduction of natural killer (NK) cell activity.

Antibodies, Monoclonal↗