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S Shibuya

Publications and source records attributed to S Shibuya.

At least 55 records · Page 3Linked to original sources
PubMed1999

Expression of selectin families and their ligand sialyl Lewis X in the muscles of inflammatory myopathies: an immunohistochemical study.

OBJECT: Adhesion molecules are suggested to play important roles in the pathogenesis of inflammatory diseases. We examined the expression of adhesion molecules in the muscles of human inflammatory myopathies. METHODS: We immunohistochemically studied the expression and distribution of two molecules in the selectin family (E- and P-selectin) and their common ligand sialyl Lewis X in 18 inflammatory myopathies, 13 disease controls, and 16 normal controls. RESULTS: In inflammatory myopathies, E- and P-selectin were upregulated on the surface of blood vessels, especially on the endothelial cells of the venules. Sialyl Lewis X was upregulated in the blood vessels, infiltrating leukocytes, and the surface of some atrophic myofibers. Some control muscles also showed weakly positive staining with these molecules, however, expression of these molecules was most striking in the muscles of inflammatory myopathies. CONCLUSION: The results suggested that these molecules are upregulated in inflammatory myopathies and might play a role in the pathogenesis of inflammatory myopathies.

Cell Adhesion Molecules↗
PubMed1999

[Infectious complications in patients with ulcerative colitis].

Several infectious disease play a role in altering the clinical course of ulcerative colitis(UC). Such infections are considered to be opportunistic infections. Especially cytomegalovirus(CMV) infection is a famous exacerbating factor. We describe a case of fulminant ulcerative colitis with methicillin-resistant staphylococcus aureus (MRSA) infection. A 55-year-old man was admitted to the hospital because of yellowish watery diarrhea. Antibiotics were administered, but the patient's condition was not improved. On the 9th hospital day, a stool culture yielded MRSA. On the 12th hospital day the patient developed toxic megacolon. Colonoscopic examination revealed the characteristic signs of UC. He underwent the emergency total colectomy and ileostomy. We emphasize in this article that MRSA infections should be recognized as an exacerbating factor of UC.

Colitis↗
PubMed1998

Codon 219 Lys allele of PRNP is not found in sporadic Creutzfeldt-Jakob disease.

The polymorphism at codon 219 of the prion protein gene (PRNP) was found in the general Japanese population with 6% allele frequency. Herein, we examined 85 cases of sporadic Creutzfeldt-Jakob disease (CJD) for the codon 219 polymorphism. The codon 219Glu/Lys heterozygous polymorphism was not found in these CJD cases. In addition, we examined 43 patients with dementia of non-CJD origin, and 4 were found to have the codon 219Glu/Lys heterozygous polymorphism with a similar allele frequency as in the general population. Thus, the codon 219Glu/Lys heterozygous polymorphism might be uniquely excluded from sporadic CJD.

Alanine↗
PubMed1998

Synthesis of 1,1-difluoro-5-(1H-9-purinyl)-2-pentenylphosphonic acids and the related methano analogues. Remarkable effect of the nucleobases and the cyclopropane rings on inhibitory activity toward purine nucleoside phosphorylase.

A series of 1,1-difluoro-5-(1H-9-purinyl)-2-pentenylphosphonic acids, (E)-2a,b and (Z)-2a,b, as well as the related methano analogues (+/-)-3a,b and (+/-)-4a,b were prepared for evaluation of their PNP inhibitory activities. The cyclopopane ring and the hypoxanthine residue were found to increase the profile of inhibitory activity. The IC50 and Ki values of difluoro¿(1R*,2S*)-2-[2-(6-oxo-6,9-dihydro-1H-9-purinyl)ethyl]cycl opropyl¿methylphosphonic acid (+/-)-3b toward PNP purified from Cellulomonas sp. were determined to be 70 nM and 8.8 nM, respectively.

Binding Sites↗
PubMed1998

[A management for severe acquired stuttering in a case of pure akinesia syndrome].

We reported a 73-year-old man with pure akinesia syndrome who showed severe acquired stuttering and paradoxical kinesia on speech. He was evaluated in another hospital for bradykinesia and frozen gait at age of 67 when his cranial MRI disclosed ischemic changes in bilateral basal ganglia and periventricular deep white matter. The treatment with L-dopa and L-threo DOPS was not effective. His symptoms were slowly progressive and got worse gradually. At age of 72, he began to have difficulty in speech due to severe acquired stuttering, and one year later, he visited our hospital. The diagnosis of pure akinesia syndrome was made because of akinesia, micrographia, marked frozen gait with paradoxical kinesia and disturbance of postural reflex without tremor and rigidity. His speech showed severe acquired stuttering with marked blocking and repetition of initial phonemes at the beginning of speech. But intelligible speech recurred with pointing the characters by his finger or with writing an initial letter of word, although his speech was small and monotonous. Surface EMG findings of muscles participating speech in acquired stuttering showed the similar tonic discharge to those of muscles of lower extremity in frozen gait. These results implied that freezing phenomenon and festination of muscles participating speech in our patient may result in acquired stuttering.

Aged↗
PubMed1997

Excretion and uptake of putrescine by the PotE protein in Escherichia coli.

The structure and function of the polyamine transport protein PotE was studied. Uptake of putrescine by PotE was dependent on the membrane potential. In contrast, the putrescine-ornithine antiporter activity of PotE studied with inside-out membrane vesicles was not dependent on the membrane potential (Kashiwagi, K., Miyamoto, S., Suzuki, F., Kobayashi, H., and Igarashi, K. (1992) Proc. Natl. Acad. Sci. U. S. A. 89, 4529-4533). The Km values for putrescine uptake and for putrescine-ornithine antiporter activity were 1.8 and 73 microM, respectively. Uptake of putrescine was inhibited by high concentrations of ornithine. This effect of ornithine appears to be due to putrescine-ornithine antiporter activity because it occurs only after accumulation of putrescine within cells and because ornithine causes excretion of putrescine. Thus, PotE can function not only as a putrescine-ornithine antiporter to excrete putrescine but also as a putrescine uptake protein. Both the NH2 and COOH termini of PotE were located in the cytoplasm, as determined by the activation of alkaline phosphatase and beta-galactosidase by various PotE-fusion proteins. The activities of putrescine uptake and excretion were studied using mutated PotE proteins. It was found that glutamic acid 207 was essential for both the uptake and excretion of putrescine by the PotE protein and that glutamic acids 77 and 433 were also involved in both activities. These three glutamic acids are located on the cytoplasmic side of PotE, and the function of these three residues could not be replaced by other amino acids. Putrescine transport activities did not change significantly with mutations at the other 13 glutamic acid or aspartic acid residues in PotE.

Amino Acid Sequence↗
PubMed1997

Immunogold and freeze etch electron microscopic studies of merosin localization in basal lamina of human skeletal muscle fibers.

Merosin is a basement-membrane-associated protein found in striated muscle, peripheral nerve and placenta, the deficiency of which causes the muscle wasting condition in C57BL/6J-dy/dy, so-called dy/dy mouse. Moreover, merosin is the binding protein of 156 kDa alpha-dystroglycan which binds dystrophin by way of 43 kDa beta-dystroglycan. Therefore, merosin is an important component of the basal lamina of normal skeletal myofibers. We investigated the ultrastructural localization of merosin antibody in normal human skeletal myofibers by using immunogold electron microscopy and freeze etch electron microscopy. The ultrastructure of the basal lamina showed the presence of the lamina lucida, lamina densa and lamina reticularis. The lamina lucida appeared electron translucent with the exception of fuzzy fibrils. The immunogold electron microscopy disclosed that the merosin was present at the innermost layer (lamina lucida) of the basal lamina of normal human skeletal myofibers. With freeze etch replica electron microscopy, short cross-bridge fine fibrils were noted in the lamina lucida, connecting the basal lamina to the outer leaflet of the muscle plasma membrane. They measured 3-13 nm in diameter, 20-90 nm in length and were distributed with a spacing of 30-40 nm. The immunogold particles showing the presence of the merosin epitope were associated with these connecting structures.

Basement Membrane↗
PubMed1997

Ultrastructural localization of alpha 1-syntrophin and neuronal nitric oxide synthase in normal skeletal myofiber, and their relation to each other and to dystrophin.

We investigated the ultrastructural localization of alpha 1-syntrophin and neuronal nitric oxide synthase (nNOS) in normal human skeletal myofibers and analyzed their relation to each other and to dystrophin using single and double immunogold-labeling electron microscopy. Single immunolabeling showed antibodies to alpha 1-syntrophin and nNOS on the inner surface of the muscle plasma membrane, the sarcoplasmic side of plasma membrane invaginations, and the sarcoplasm near mitochondria of subsarcolemmal areas. The epitopes of alpha 1-syntrophin and nNOS tended to be present in clusters. Double immunolabeling revealed that epitope combinations of alpha 1-syntrophin-dystrophin, alpha 1-syntrophin-nNOS, and nNOS-dystrophin occurred more frequently in doublet form than did other epitope combinations, such as alpha 1-syntrophin-beta- spectrin and nNOS-beta-spectrin. These increased frequencies were noted both at the muscle plasma membrane undercoat and near mitochondria of subsarcolemmal areas. A significantly higher percentage of doublets comprised antibodies against alpha 1-syntrophin and dystrophin (28.5 +/- 1.5%, group mean +/- SE) than those against alpha 1-syntrophin and beta-spectrin (9.2 +/- 0.8%, P < 0.01). Furthermore, nNOS formed doublets significantly more frequently with dystrophin (25.2 +/- 3.3%) and alpha 1-syntrophin (26.0 +/- 4.1%) than with beta-spectrin (13.9 +/- 2.3%; P < 0.05). These data support the association of dystrophin, alpha 1-syntrophin, and nNOS at the inner surface of the muscle plasma membrane and near mitochondria of subsarcolemmal areas of normal human skeletal myofibers.

Amino Acid Sequence↗
PubMed1997

A comparative freeze-fracture study of plasma membrane of dystrophic skeletal muscles in dy/dy mice with merosin (laminin 2) deficiency and mdx mice with dystrophin deficiency.

The intramembranous particle (IMP), orthogonal array (OA) and orthogonal array subunit particle (OASP) densities of skeletal muscle plasma membranes of merosin deficient dy/dy mice and their control mice at 7, 14 and 28 days after birth were analysed by freeze-fracture electron microscopy. Similar studies were performed on dystrophin-deficient mdx mice with mild muscle weakness at 28 days after birth for the comparison with those of dy/dy mice with severe muscle weakness at the same age. In the pre-clinical stage of dy/dy mice at 14 days after birth, the membranes showed a significantly decreased density of OAs (P<0.01 by Wilcoxon rank-sum test) as compared with control mice, while those in the clinical stage of dy/dy mice at 28 days after birth showed normal IMP density but a marked depletion of OA density (P<0.01). Moreover, at 28 days after birth, the reduction of OAs in the plasma membranes of dy/dy mice was more marked than that of mdx mice (P<0.05 by Wilcoxon rank-sum test). These results provided us with the information that the OA density was affected more severely with merosin deficiency than with dystrophin deficiency, and again supported our previously proposed concept that the clinical severity in muscular dystrophies correlated with the OA density.

Animals↗
PubMed1997

An improved endoscopic variceal ligation for esophageal and solitary gastric varices--three-O-band-shooter.

We have reported a 16.0 mm long new type of instrument with the inner diameter of inner cylinder of 10.3 mm for endoscopic variceal ligation which could shoot 3 elastic O bands continuously in short period of time without removing the endoscope. The suction volume of new instrument is larger than that of the Stiegmann's ligator. We performed endoscopic variceal ligation (EVL) in 17 cases of the esophageal varix and 8 cases of the solitary gastric varix. EVL was performed as prophylaxis as all the cases. The esophageal varices were eliminated in all the cases after ulcer formation. The procedure was performed one time in 15 cases and two times in the remaining 2 cases. Three patients died one to hepatic failure during the follow-up period between 4 and 16 months. Six and twelve months cumulative recurrence rates were 30% and 48% respectively. On the other hand all the gastric varices disappeared after one sitting of the treatment. There was one variceal recurrence during the follow-up period. Computed tomography and/or arterioportography performed before had showed patent gastro-renal shunt in five cases. No change in the shunt was observed after the treatment. No serious complications due to EVL was encountered in all the cases. Therefore, it is thought that this method can be used for the treatment of not only esophageal varices but also gastric varices.

Endoscopes↗
PubMed1997

Hepatic coma recovered after interventional obliteration for ileocecal-inferior vena cava shunt--report of one case.

We performed interventional angiography (IVA) in a patient with liver cirrhosis (LC) and hepatoma (HCC) who experienced repeated attacks of unconsciousness due to hyperammonemia caused by ileocecal-inferior vena cava (IC-IVC) shunt and succeeded in the treatment. We report the results below. The patient, 53-year-old male, underwent endoscopic injection sclerotherapy for esophageal varix due to LC followed by splenectomy for pancytopenia in 1986. He made good progress. However intraarterial anticancer therapy was conducted for HCC in 1994. From that time hepatic coma began to appear and its frequency gradually increased. Hepatic coma occurred once every 3 weeks from June 1996. He was thus admitted to our hospital. Hematobiochemical testes showed that ammonia level was 297 mcg/dl. Albumin 2.8d/dl, and Total-Bilirubin 10.78 mg/dl. Arterioportography from superior mesenteric artery showed most of portal blood flowed away from the liver though the ileocolic vein to IVC. We decided to conduct IVA for treatment. Specially, a 6Fr balloon catheter was inserted from the right inguinal region into a shunt to the portal vein though IVC by the Seldinger technique. The balloon was inflated in the shunt to close the shunt. Six ml of 5% ethanolamime oleate with iopamidol was injected because retrograde angiography showed that iopamidol was flowed out via testicular vein to IVC. The balloon catheter was retained for 24 hours. Angiography, conducted from the catheter again 24 hours later, showed that the shunt was occluded, blood ammonia level was 71 mcg/dl after occlusion. Hepatic coma was not observed after treatment. We encountered a very rare case who repeated hepatic comas due to IC-IVC shunt and recovered dramatically after IVA.

Angiography↗
PubMed1996

Humanized prion protein knock-in by Cre-induced site-specific recombination in the mouse.

To establish humanized mice with a knock-in (gene replacement) technique, we constructed a targeting vector which consists of the human prion protein and the loxP sequences. The introduced human prion protein with the loxP system in the embryonic stem cells was transmitted through the mouse germ line. Transient expression of Cre recombinase in the fertilized eggs resulted in the prion protein humanized mice. The Cre-loxP-mediated gene replacement is a simple and efficient method which is generally applicable to make humanized animal models.

Animals↗
PubMed1996

Spermidine-preferential uptake system in Escherichia coli. Identification of amino acids involved in polyamine binding in PotD protein.

Spermidine-binding sites on PotD protein, substrate-binding protein in periplasm, in the spermidine-preferential uptake system in Escherichia coli were studied by measuring polyamine transport activities of right-side-out membrane vesicles with mutated PotD proteins prepared by site-directed mutagenesis of the potD gene and by measuring polyamine binding activities of these mutated PotD proteins. Polyamine transport activities of the mutated PotD proteins paralleled their polyamine binding activities. It was found that Trp-34, Thr-35, Glu-36, Tyr-37, Ser-83, Tyr-85, Asp-168, Glu-171, Trp-229, Trp-255, Asp-257, Tyr-293, and Gln-327 of PotD protein were involved in the binding to spermidine. When spermidine uptake activities were measured in intact cells expressing the mutated PotD proteins, it was found that Glu-171, Trp-255, and Asp-257 were more strongly involved in the binding of spermidine to PotD protein than the other amino acids listed above. The dissociation constants of spermidine for the mutated PotD proteins at Glu-171, Trp-255, and Asp-257 increased greatly in comparison with those for the other mutated PotD proteins. Since these three amino acids clearly interact with the diaminopropane moiety of spermidine, the results are in accordance with the finding that PotD protein has a higher affinity for spermidine than for putrescine. Putrescine was found to bind at the position of the diaminobutane moiety of spermidine.

Amino Acid Sequence↗
PubMed1996

Ultrastructural localization of adhalin in normal murine skeletal myofiber.

The ultrastructural localization of adhalin and its relations to dystrophin, beta-dystroglycan, and beta-spectrin were studied in normal murine skeletal myofibers. The C-terminal peptides of adhalin and beta-dystroglycan were synthesized based on their cDNAs, and the affinity-purified antibodies against these peptides were produced. Single-immunolabeling electron microscopy showed that the adhalin was located just inside the muscle plasma membrane or inside the myofiber a short distance from the plasma membrane. The adhalin signal was also noted at the sarcoplasmic side of plasmalemmal invaginations or at vesicular structures in subsarcolemmal areas. Double-immunogold-labeling electron microscopy disclosed a similar localization of dystrophin, beta-dystroglycan, and beta-spectrin. The close association of adhalin with dystrophin or beta-dystroglycan was demonstrated by formation of doublets by signals of antibodies of adhalin with those of dystrophin or beta-dystroglycan and was confirmed by statistical analyses. This study demonstrated that the location of adhalin is close to that of dystrophin and beta-dystroglycan at the muscle plasma membrane.

Animals↗