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Biomedical subjects

I Toyoshima

Publications and source records attributed to I Toyoshima.

At least 55 records · Page 3Linked to original sources
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

Detection and isolation of a 30 kDa abnormal protein in avian dystrophic muscle.

We have studied the protein composition of the pectoralis superficialis muscle of genetically dystrophic (New Hampshire line 413) and normal control (line 412) chickens by one- and two-dimensional gel electrophoresis. A protein, referred to hereafter as the 30 kDa abnormal protein, was specifically detected in the affected muscle. It was purified to homogeneity, and its molecular properties were studied. It is a monomer with a molecular mass of approximately 30 kDa and an isoelectric point of about pI 8.4. We have screened by Western blotting a variety of muscles from line 412 and line 413 chickens for the presence of the 30 kDa protein. While the pattern of total protein is very similar in all cases, the 30 kDa protein was not detected in the pectoralis superficialis muscle of line 412 chickens. However, the immunoreactive bands were detected in the sartorius muscle and the tensor fasciae latae muscle from dystrophic and normal chickens. Interestingly, the immunoreactive bands of normal skeletal muscles are smaller in molecular weight than those of dystrophic skeletal muscles. To determine the early time sequence of the appearance of the abnormal protein, we studied muscles from embryos and post-hatched chickens at various ages. The abnormal protein was detected in dystrophic muscles as early as 15 days ex ovo and occurred throughout development up to six months ex ovo. Although the implication of the dystrophy-associated appearance of the 30 kDa protein in the affected muscle is not clear at present, it would be of particular interest to elucidate the biochemical functions of the 30 kDa protein in the affected muscle (pectoralis superficialis muscle) of genetically dystrophic chicken.

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↗
PubMed1990

[A new autoantibody, anti-210kDa microtubule associated protein antibody, detected in the serum of patients with various liver diseases and SLE].

A new autoantibody to 210kDa microtubule associated protein (MAP) obtained from rabbit liver excrude was detected in the serum with various liver diseases and SLE. As there were no reports concerning autoantibodies to MAPs in animals and human, it may say that anti-210kDa MAP autoantibody we detected was a new cytoskeleton antibody. Using western blotting method, the anti-210kDa MAP autoantibody was frequently found in the patients with alcoholic liver diseases (52.5%), PBC (55.6%), autoimmune hepatitis (83.3%), SLE (71.4%) but rarely in the patients with viral liver diseases (26.4%) and none in normal controls at a serum dilution of 1:10. In addition, at a serum dilution of 1:100, the anti-210kDa MAP autoantibody was found in the patients with alcoholic liver diseases (22.5%), PBC (44.4%), autoimmune hepatitis (66.7%), SLE (71.4%), viral liver diseases (17.0%) and none in normal controls. It was confirmed that the anti-210kDa MAP autoantibody was frequently detected in cases of alcoholic liver diseases, PBC, autoimmune hepatitis and SLE than in those of viral liver diseases and normal control.

Autoantibodies↗
PubMed1989

Phosphorylation of neurofilament proteins and localization of axonal swellings in motor neuron disease.

Seven lumbosacral spinal cords with motor neuron disease were examined immunocytochemically with monoclonal antibodies (MAb) directed against neurofilament proteins (NFP). Each of the 5 MAbs used in this study was monospecific to one of the triplet of NFP. Two of them were specific to the highly phosphorylated form of high molecular weight peptide of NFP (NFP-H). All 5 MAbs stained all axonal swellings examined. In 2 spinal cords examined, some axonal swellings were found in the anterolateral funiculus and some of these were as far as 1000 microns from the grey matter. This localization of axonal swellings suggests that a high degree of phosphorylation of NFP is not the cause of accumulation of NFP in axonal swellings in motor neuron disease.

Adult↗
PubMed1989

[Studies of microtubule associated proteins in the liver--isolation of a 210 kDa microtubule associated protein from rabbit liver].

The biochemical characteristics and cellular localization of microtubule associated proteins (MAPs) were studied using rabbit liver. The MAPs fraction, isolated from rabbit liver crude extract by a modification of Vallee's method, consisted of several proteins, as identified by SDS-polyacrylamide gel electrophoresis. The most prominent of these was a 210 kDa protein (rabbit 210 kDa MAP). The molecular weight of rabbit 210 kDa MAP was distinct from that of the major brain MAPs, MAP1, MAP2 and Tau, isolated from rabbit brain crude extract by same method. Monoclonal antibodies (mAb) to this rabbit 210 kDa MAP were raised. Using immunoblotting method, we confirmed that anti-rabbit 210 kDa MAP mAb reacted to 210 kDa protein from rabbit liver excrude, while this mAb also reacted to 210 kDa protein from rabbit brain excrude. Immunofluorescent staining using fixed rabbit liver was carried out using these mAb. In frozen sections of the rabbit liver, the antigen related to mAb 7B10 was localised in the hepatic cells and epithelial cells of the bile duct but not in the smooth muscle cells and endothelial cells.

Animals↗
PubMed1988

Processing of neurofilament proteins from perikaryal to axonal type.

In previous studies, neuronal cell bodies, excised by hand from bovine spinal ganglia, were analyzed and heterogeneous intermediate and high molecular weight neurofilament proteins that differed in electrophoretic mobility from their axonal counterparts were demonstrated. In the present experiment, intermediate and high molecular weight neurofilament proteins of the axonal type were treated with alkaline phosphatase, and neurofilament proteins enriched in perikaryal type proteins were labeled with 32P. Results showed that neurofilament proteins were phosphorylated after their translation, in the perikarya and the proximal portion of the axon, and suggested that phosphorylation was responsible for the differences between axonal and perikaryal neurofilament proteins.

Animals↗
PubMed1988

Effect of tetrahydrobiopterin and 5-hydroxytryptophan on hereditary progressive dystonia with marked diurnal fluctuation: a suggestion of the serotonergic system involvement.

A daughter and her mother developed hereditary progressive dystonia with marked diurnal fluctuation (HPD) at the age of 4 and 34, respectively. L-Dopa, tetrahydrobiopterin (BH4) or 5-hydroxytryptophan (5-HTP) was orally administered to them. L-Dopa cured completely their symptoms. 5-HTP as well as BH4 improved their symptoms, especially dystonic movements. Biopterin and 5-hydroxyindoleacetic acid concentrations in CSF increased during BH4 medication. These findings suggest that the serotonergic system of the central nervous system might play some role in the pathogenesis of dystonia in HPD.

5-Hydroxytryptophan↗
PubMed1988

Serum antibodies to brain proteins in a patient with parkinsonism associated with IgM paraproteinemia.

We report a 58 year-old man with various neurological symptoms as parkinsonism, autonomic dysfunction, mental deterioration and lower motor neuron involvement associated with IgM gammopathy whose serum showed antibody activities to human brain proteins. His serum reacted with 156kDa protein from substantia nigra and 130kDa of cerebral cortical grey matter, cerebellar cortex, putamen, thalamus or pallidum by immunoblotting method. The serum of this patient reacted with proteins widely distributed in the central nervous system, and this antibody in his serum might be the cause of his various neurological symptoms.

Autoantibodies↗
PubMed1986

Antibodies to brain proteins in paraneoplastic cerebellar degeneration.

A 68-year-old man had subacute cerebellar degeneration and a non-Hodgkin's lymphoma. Using an immunoblotting method, we found serum antibodies to rat cerebral 250-kd and 110-kd and cerebellar 110-kd acidic cytoplasmic proteins. The antibodies did not react unless the antigens were prepared soon after death with protease inhibitors. Two hundred fifty-kd and 110-kd proteins are minor components of soluble cytoplasmic proteins of the brain. The molecular weights differed from other soluble brain-specific proteins already characterized.

Aged↗
PubMed1984

Carrier detection of sialidosis with partial beta-galactosidase deficiency by the assay of lysosomal sialidase in lymphocytes.

Lysosomal and plasma membrane sialidase activities in lymphocytes were studied in four patients with sialidosis with partial beta-galactosidase deficiency, four obligate heterozygotes, and three siblings of a patient. Lysosomal sialidase activity in homozygotes was absent, and that in heterozygotes was significantly decreased to 70% of control level. The results indicate that carriers can be detected by the assay of lysosomal sialidase activity of lymphocytes.

Adult↗
PubMed1984

[An electrophoretic study of the muscle proteins in nemaline myopathy: a new method using type-defined freeze-dried sections].

The characteristic features observed in the muscle fibers of nemaline myopathy are the presence of rods mainly in type I fibers, and the predominance and atrophy of type I fibers. In order to detect the abnormal proteins in the rods and clarify whether type I or II fibers have abnormal structural protein, we examined proteins in the muscles of patients with nemaline myopathy by one and two-dimensional gel electrophoresis (2-D). These freshly frozen muscles were cut to 20 microns thick and freeze-dried. Pieces were chosen and teased under a dissecting microscope with reference to the stained specimens of the same part, and electrophoresed. At first, we examined the proteins of the type I and II fibers in normal and type grouping fibers of patients with motor neuron disease by SDS gel electrophoresis and found no abnormality of the protein pattern in this disease. Then we examined each of the following fibers of the nemaline muscle; type I fibers with many rods and type II fibers with no rods. Each of the electrophoresed gel patterns of the nemaline muscle was compared with those of grouping type I and II fibers. The SDS gel electrophoresis showed and increase of the intensity of 55 K band in nemaline myopathy, especially in type I fibers with rods, which was thought as desmin. In 2-D, the pattern of type I fibers with rods were identical to that of the grouping type I fibers except the 55 K spot which showed a slow form of tropomyosin alpha-subunit (TM-alpha), troponin-C (TN-C) and myosin light chains (LC) although both contained small amounts of fast form LC2 and LC3.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1983

[Electrophoresis of proteins of muscle fibers with rimmed vacuoles].

This is the first report on the analysis of the proteins in the single muscle fibers with rimmed vacuoles. A new method was developed to analyse single muscle fibers which had been histologically characterized in the freeze-dried sections of muscles. Muscle biopsy was performed in three patients with distal myopathy and one patient with Kearns-Sayre-like syndrome associated with rimmed vacuoles (Table 1). Ten (30 micron thick) frozen serial sections were dried according to Lowry and Passonneau, and further five consecutive sections were cut and stained with usual histochemical methods including Gomori trichrome and NADH-TR staining. Each muscle fiber in the freeze-dried sections could be identified with the corresponding one in the stained sections, and it was possible to determine whether the fiber had rimmed vacuoles or not (Fig. 2). Particular fibers were identified in the consecutive freeze-dried sections and cut out from three sections with no contamination of the interstitial tissue, and they were subjected to SDS gel electrophoresis. Resultant gel patterns showed substantial increase of 55 k dalton band, the extent of which was much more larger in that of the fiber with rimmed vacuoles than that without vacuoles (Fig. 3). This feature was common to all of the gels from four patients. A portion containing a number of muscle fibers of a freeze-dried section from each of the four patients and the two controls was subjected to two-dimensional gel electrophoresis (2-D). Of 55 k dalton proteins, three spots around the isoelectric point of alpha-actin were found to be increased (Fig. 4).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗