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Biomedical subjects

S Shibuya

Publications and source records attributed to S Shibuya.

At least 73 records · Page 4Linked to original sources
PubMed1996

Electron microscopic observations of triple immunogold labelling for dystrophin, beta-dystroglycan and adhalin in human skeletal myofibers.

Dystrophin is the Duchenne muscular dystrophy gene product and is a membrane cytoskeletal protein present in the network of the plasma membrane undercoat. Adhalin (50 kDa dystrophin-associated glycoprotein) and beta-dystroglycan (43 kDa dystrophin-associated glycoprotein) are the transmembrane components of the normal muscle plasma membrane, and beta-dystroglycan has been demonstrated to bind dystrophin at the inside surface of normal muscle plasma membrane. This investigation was undertaken to test whether the epitopes of dystrophin, beta-dystroglycan and adhalin are closely associated with each other by using triple immunogold labelling electron microscopy on normal human skeletal myofibers. Although closely associated signals of triplet immunogold particles were observed, there were less numerous than expected. However, closely associated signals of two epitopes of dystrophin and beta-dystroglycan, dystrophin and adhalin, or adhalin and beta-dystroglycan were frequently observed. These ultrastructural findings are consistent with biochemical evidence implying that dystrophin, beta-dystroglycan and adhalin are closely associated with each other at the normal muscle plasma membrane.

Cytoskeletal Proteins↗
PubMed1996

[Differentiation of extravillous trophoblast during normal pregnancy].

The implantation site in 25 pregnant uteri was studied morphologically and immunohistochemically to clarify the developmental process of extravillous trophoblasts (EVTs). 1. Dense trophoblastic invasion of the decidua was observed. Multinuclear trophoblasts appeared in the deciduo-muscular junction from the 10th week. Trophoblasts infiltrated decidual vessel walls, where extensive perivascular degeneration existed. EVTs may be indispensable for construction of the placenta. 2. In villous trophoblasts (VTs) the location of hCG and hPL was limited to multinuclear cells, whereas in EVTs hCG was present in a few mononuclear cells and hPL was observed in most mononuclear and multinuclear cells. The immunoreactivity of trophoblast-related monoclonal antibodies also differed: neither anti-Tropl (reactive with cytotrophoblasts (CTs)) nor NDOG1 (reactive with syncytiotrophoblasts (STs)) was reactive with EVTs. 3. The absence of hCG and hPL in mononuclear trophoblasts of the cell column indicates that EVTs differentiate after invading the decidua. Kurman et al. proposed the term intermediate trophoblast, indicating cells in transition from CTs to STs and EVTs, and this is based on the concept that the developmental processes of EVTs and VTs are identical. But the results of this study suggested an independent developmental process for EVTs and therefore it seemed that the term intermediate trophoblast should not be employed for EVTs.

Cell Differentiation↗
PubMed1995

[Intra-arterial 5-FU/intra-venous MTX therapy for metastatic liver lesions].

We have performed intra-arterial 5-fluorouracil (5-FU)/intra-venous methotrexate (MTX) therapy for 4 patients with multiple metastatic liver tumors at out-patient clinic. Primary lesions were of the stomach (one patient, synchronous) and colon (3 patients, two were synchronous and one was metachronous). 5-FU (250-350 mg/day) was continuously infused for two weeks into the hepatic artery through the reservoir using the Baxter Infuser (multi-day type). MTX (100 mg/m2) was infused into the peripheral vein on days 1, 8 and 15. Leucovorin calcium (15 mg) was orally administered three times after MTX infusion. All patients partially responded, and no remarkable side effect was detected. We propose that this new combination therapy, that is intra-arterial 5-FU and intra-venous MTX for metastatic liver cancer, can be useful and safe even for out-patients.

Administration, Oral↗
PubMed1995

Ultrastructural localization of the C-terminus of the 43-kd dystrophin-associated glycoprotein and its relation to dystrophin in normal murine skeletal myofiber.

We used single and double immunogold labeling electron microscopy to investigate ultrastructural localization of the C terminus of the 43-kd dystrophin-associated glycoprotein (43-DAG) and its relationship to dystrophin in normal murine skeletal myofibers. Single immunolabeling localized the antibody against the C terminus of 43-DAG to the inside surface of the muscle plasma membrane and the sarcoplasmic side of plasma membrane invaginations. Double immunolabeling co-localized antibodies against dystrophin and the C terminus of 43-DAG to the same site noted in the single immunolabeling localization of 43-DAG. In particular, dystrophin and the C-terminal 43-DAG antibody signals were often observed as doublets separated by less than 30 nm. We compared these results with those obtained from double immunogold labeling with anti-dystrophin and anti-beta-spectrin, as well as anti-C-terminal 43-DAG and anti-beta-spectrin antibodies. The antibodies against dystrophin and beta-spectrin, or beta-spectrin and 43-DAG, also co-localized to similar sites in skeletal muscle fibers. Signals of doublet formations were noted but their frequency was significantly lower than the doublet frequency of antidystrophin and anti-43-DAG antibodies. The results support the presence of dystrophin and 43-DAG linkage at the inside surface of the murine skeletal muscle plasma membrane.

Amino Acid Sequence↗
PubMed1994

Freeze-fracture analysis of muscle plasma membrane in Becker's muscular dystrophy.

The intramembranous particle (IMP), orthogonal array (OA) and orthogonal array subunit particle (OASP) densities in skeletal muscle plasma membranes from eight patients with Becker's muscular dystrophy (BMD) were analysed by the freeze-fracture technique. The results showed almost normal IMP density with the significant decrease of OA and OASP densities in BMD. The group mean densities +/- SE of IMPs on the protoplasmic faces with and without OASPs, and on extracellular faces/microns 2 were 2137 +/- 207, 1839 +/- 68 and 895 +/- 108, respectively in controls; whereas those of BMD were 1989 +/- 259, 1837 +/- 203 and 900 +/- 239, respectively (P > 0.1 by two-tailed t-test). The group median density of OAs and their pits/microns 2 was 4.89 with mid-ranges (25-75% values of the counts) of 2.66-10.18 in controls; whereas that in BMD was 2.15 with mid-ranges of 1.14-4.31 (P < 0.01 by Wilcoxon rank-sum test). The group mean density +/- SE of OASPs in controls was 15.99 +/- 1.83; whereas that in BMD was 13.47 +/- 1.07 (P < 0.01 by two-tailed t-test). However, the diminution of OA and OASP densities in BMD muscle plasma membranes was not as severe as in Duchenne's muscular dystrophy. There was a relationship between OA density and clinical severity in BMD patients; the decrease of OA density in a severe BMD patient was more marked than that in mildly affected BMD patients. Therefore, it seems that marked depletion of OA density may lead to the severe disability in muscular dystrophies.

Adolescent↗
PubMed1994

Immunoelectron microscopic localization of C-terminus of 43-kDa dystrophin-associated glycoprotein in normal human skeletal myofibers.

Ultrastructural localization of the C-terminus of a 43-kDa dystrophin-associated glycoprotein (43-DAG) and its relation to dystrophin were investigated in normal human skeletal myofibers by using single and double immunogold labelling methods. The C-terminal end of 43-DAG antibody was localized ultrastructurally at the inside surface of muscle plasma membrane and the sarcoplasmic side of the plasma membrane invaginations. Double immunolabelling electron microscopy disclosed that signals of the C-terminal end of 43-DAG and dystrophin were often associated with each other and formed a doublet at the inside surface of plasma membranes in normal human skeletal myofibers.

Cytoskeletal Proteins↗
PubMed1994

[Home chemotherapy for peritoneal carcinomatosis].

Nineteen patients diagnosed with peritoneal carcinomatosis were treated by in-home chemotherapy over a period of four years from August, 1990 to July, 1994. Primary diagnoses of the four male and 15 female patients included 12 cases gastric cancer (four males, eight females), five cases of ovarian cancer, one case (female) of appendicular cancer, and one case (female) of breast cancer. In addition to oral administration of UFT-E and 5'-DFUR, chemotherapy included weekly intravenous injection of a massive dose of 5-FU (1,000 mg/m2), subselective intraaortic infusion and intraperitoneal infusion using a reservoir. These methods were used individually and in combination. The drugs used included 5-FU, CBDCA, CPA, THP, and EPIR. Subselective intraaortic infusion was performed by low dose continuous infusion using the Baxter infusor multiday type. Six gastric cancer patients lived normally for over one year, while four died in less than a year. All ovarian and appendicular cancer patients were CR, the breast cancer patient was PR. Ten patients continued working at their jobs while receiving at home chemotherapy treatments. Diuretics were used to alleviats ascites. Although there were no side effects on digestive organs, 5-FU and CBDCA were mixed with 100 mg hydrocortisone in the infusor to improve cachexia, and promote appetite and activity. Bone marrow suppression was very slight at these dosages, and weekly checkups were adequate. The at-home rate (number of days at home/entire period since onset) of all patients was 78%.

Adult↗
PubMed1993

Size and localization of dystrophin molecule: immunoelectron microscopic and freeze etching studies of muscle plasma membranes of murine skeletal myofibers.

The ultrastructure and mode of existence of the dystrophin molecule and its relations to actin filaments were examined in murine skeletal myofibers. Electron microscopy of freeze-etched replicas of gold-labelled dystrophin molecules in quick-freeze, deep-etch, rotary-shadow preparations revealed rod-like structures 108.2 +/- 16.3 nm long and 3.1 +/- 1.5 nm thick. Some dystrophin molecules appeared to link their ends to form anastomosing networks; others were separate from each other. The dystrophin molecules were parallel or nearly parallel to the inner surface of the muscle plasma membrane. Double immuno-labelling transmission electron microscopy using N- and C-terminal dystrophin antibodies showed that the group mean distances of the N- and C-terminal signals from the muscle plasma membrane were 52.7 +/- 8.1 nm and 45.9 +/- 11.3 nm, respectively, which were not significantly different. Histograms of the distribution of the N- and C-terminal distances from the muscle plasma membrane had similar patterns with peaks 10-20 nm from the membrane. This was consistent with the findings of the mode of existence of dystrophin molecules seen in freeze-etched replicas. Finally, the dystrophin molecules were linked with the most peripheral sarcoplasmic actin like filaments, end to side as well as end to end.

Amino Acid Sequence↗
PubMed1992

High levels of nervous system-specific proteins in cerebrospinal fluid in patients with early stage Creutzfeldt-Jakob disease.

Concentrations of several proteins that are characteristic of the nervous system were time-sequentially analyzed by radio- and enzyme-immunoassay in the cerebrospinal fluid (CSF) of patients with Creutzfeldt-Jakob disease (CJD). We found abnormally high levels of several proteins, such as neuron-specific enolase (NSE), S-100b protein, brain-type isozyme of creatine kinase (CK-BB) and alpha subunit of GTP binding protein G0 (G0 alpha) in the early stage of the disease. Generally, these protein levels were far higher in CJD patients than in normal controls and other neurological patients in the early stage before the typical clinical manifestations were evident. These levels increased to maxima when the disease activity was most prominent and returned to normal or mildly elevated levels in the terminal stage. The results imply that these protein levels can serve as biochemical markers for the presence of an active destructive process in CJD brain and provide us with a useful indicator for early diagnosis of CJD.

Brain↗
PubMed1992

Esophageal ulcer due to ingestion of melted copper.

We report a patient with esophageal stricture as a result of the accidental swallowing of melted copper by a 49-year-old male. As a result, esophagogastric ulcers developed and left a cicatrical stricture. The patient could only manage to swallow liquid food. Radiology of the upper gastrointestinal tract showed marked stricture of the esophagus from the middle thoracic portion to the esophagogastric junction and shortening of the lesser curvature of the stomach. The patient underwent a single-session total gastrectomy, and excision of the thoracic esophagus and construction of anterior thoracic esophagocolic and duodenocolic anastomoses were performed by right thoracotomy and laparotomy, respectively. Macroscopic findings of the surgical specimens showed extensive circular ulcers at the esophagus, and microscopic findings showed deep ulcers extending to the muscle layer with marked fibrosis. The postoperative course was uneventful.

Accidents, Occupational↗
PubMed1992

Strong immunoreactivity of cathepsin L at the site of rimmed vacuoles in diseased muscles.

Skeletal muscle samples from four patients with myopathies showing autophagic vacuole formation were examined by immunohistochemical, biochemical and immunoblot analyses. Immunochemical studies demonstrated strongly positive reactions of cathepsins B and L in and around the rimmed vacuoles and weak reactions in intramyofibral portions of degenerating muscle fibres. Faint staining of cathepsin H was also seen at the sites of rimmed vacuoles. Biochemical analyses showed increased activity of cathepsin B and L in muscle specimens from the patients with rimmed vacuole formation. However, there was no remarkable cathepsin H activity in the muscle specimens from these patients. Cathepsin L immunoblot analysis of muscle extracts showed three bands with molecular masses of 30 kDa, 36 kDa and 39 kDa. The immunostaining of cathepsin L from patients with rimmed vacuole formation was stronger than that of normal controls. Cathepsin B immunoblot analysis showed only faint bands in samples from patients with rimmed vacuole formation and normal controls. This study demonstrated, for the first time, strong immunoreactivity of cathepsin L at the sites of rimmed vacuoles. Possible mechanisms of rimmed vacuole formation are discussed.

Adult↗
PubMed1991

Gold-labelled dystrophin molecule in muscle plasmalemma of mdx control mice as seen by electron microscopy of deep etching replica.

The Duchenne muscular dystrophy product 'dystrophin' has been shown to be located at the inner surface of normal muscle plasma membrane. This study was undertaken to visualize the shape of dystrophin molecules and their topographical distribution at the inner surface of murine skeletal muscle plasma membrane. The immunogold electron microscopy of plastic-embedded quadriceps femoris muscles of six mdx mice and six control mice showed the presence of gold particles along the muscle plasma membrane undercoat of all muscle samples from the control mice without any antibody reaction in the mdx mice muscles. The gold-labelled muscles of six mdx and six control mice were quickly frozen by liquid helium in a rapid-freeze apparatus. High magnification electron microscopy of the quick-freeze, deep-etch, rotary-shadow replicas of the gold-labelled muscles demonstrated the presence of dystrophin molecules associated with gold particles at the cytoplasmic surface of mdx control mice. The dystrophin molecules displayed a variety of shapes, such as rods with a reduction in diameter from one end to the other end and/or with the enlargement of their end(s). These dystrophin molecules were incorporated in the meshwork of muscle plasma membrane-associated cytoskeletons.

Animals↗
PubMed1991

The presence of cis-9,10-methylene hexadecanoic acid in Yersinia enterocolitica.

The fatty acids of Yersinia enterocolitica were investigated by Abbas and Card. In their report, they stated that the major fatty acids were C16:0, C16:1, C17:0 and C18:1 and branched or cyclopropane side-chain fatty acids could not be detected. We, however, found a moderate amount of cyclopropane side-chain fatty acid. We could determine that this fatty acid was cis-9, 10-methylene hexadecanoic acid by gas-liquid chromatography, gas chromatography-mass spectrometry, silver-nitrate-treated TLC and PtO2 catalyzing hydrogenation method.

Chromatography↗
PubMed1991

Adaptational changes of fatty acid composition and the physical state of membrane lipids following the change of growth temperature in Yersinia enterocolitica.

Yersinia enterocolitica is capable of growing in a broad range of temperatures from 4 to 45 C. How this organism alters its membrane lipids in response to the change of growth temperature is very interesting. The fatty acids of membrane lipids of cells cultured at 5, 15, 25 and 37 C were analyzed and the physical states of these membrane lipids were characterized. The major phospholipids of this bacterium were phosphatidylethanolamine, phosphatidylglycerol, cardiolipin, lysophosphatidylglycerol and lysophosphatidylethanolamine. No significant difference in phospholipid composition in response to culture temperatures was observed. It was reported in our previous paper that the major fatty acids of membrane phospholipids of Y. enterocolitica were C15:0, C16:0, C16:1, cyclopropane C17:0 and C18:0. Some differences in the fatty acid composition were, however, observed with the change of culture temperature. When the culture temperature was raised, the saturated and cyclopropane fatty acids substantially increased and the unsaturated ones decreased. A reverse phenomenon was observed when culture temperature was lowered. From the viewpoints of membrane physical state, adaptational changes were analyzed using a nylon microcapsule method. Phase transition in membrane lipids of cells grown at each culture temperature took place in the range of about 5 C below and about 10 C above the culture temperature. It is, therefore, considered that Y. enterocolitica maintains its membrane rigidity and fluidity in response to growth temperature by changing the membrane fatty acid composition.

Capsules↗
PubMed1991

Changes in muscle plasma membranes in young mice with X chromosome-linked muscular dystrophy: a freeze-fracture study.

The structure of the muscle plasma membrane of tibialis anterior muscles of X chromosome-linked muscular dystrophy (mdx) mice was studied by the freeze-fracture technique at 3, 7 and 14 days after birth. The ultrastructural features of the freeze-fracture replicas of the muscle plasma membrane alterations in young mdx mice showed a decrease of orthogonal array, orthogonal array subunit particle and intramembranous particle densities on the protoplasmic face. The results are consistent with the previous studies which have shown that the orthogonal arrays are significantly decreased in number in muscle plasma membranes of adult mdx mice and in those of Duchenne dystrophy. However, the immature mdx mouse membranes at 3 days after birth contained as many orthogonal arrays as controls and did not show a statistically significant decrease (P greater than 0.1 by the Wilcoxon rank-sum test). Moreover, the orthogonal arrays were also numerous in young mdx mouse muscle plasma membranes at 7 and 14 days after birth, although the density was less than that of the control mice (P less than 0.01 by the Wilcoxon rank-sum test). These changes in young mdx mouse plasma membranes may precede the later muscle fibre degeneration in this mouse dystrophy and may provide us with an additional clue to the mechanism why mdx mice scarcely show any disability despite the absence of dystrophyn.

Animals↗
PubMed1991

Antibody-decorated dystrophin molecule of murine skeletal myofiber as seen by freeze-etching electron microscopy.

Dystrophin is the protein product of Duchenne muscular dystrophy gene which is defective in this genetic disorder. Here we identified ultrastructurally the dystrophin molecule from the various cytoskeletons at the cytoplasmic surface of murine myofiber plasma membrane by using quick-freeze, deep-etch, rotary-shadow replica of anti-dystrophin antibody-decorated muscle samples. The molecule was really cytoskeleton and incorporated in the meshwork of the plasma membrane-associated cytoskeletons. The molecule appeared to connect directly and/or through another cytoskeletal molecule with actin filament.

Actins↗