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Biomedical subjects

Y Shibata

Publications and source records attributed to Y Shibata.

At least 19 recordsLinked to original sources
PubMed1992

Arsenic lipids in the digestive gland of the western rock lobster Panulirus cygnus: an investigation by HPLC ICP-MS.

The digestive gland of the western rock lobster, Panulirus cygnus, was shown to contain phosphatidylarsenocholine and a phosphatidyldimethylarsinylriboside by HPLC ICP-MS examination of lipid materials rendered water-soluble by hydrolysis. Water-soluble arsenic material in the digestive gland was chiefly arsenobetaine but the deacylated analogue of the phosphatidyldimethylarsinylriboside and an unidentified compound were also present.

Animals↗
PubMed1992

Endoglycosidase H digestion of Yukb (Pena) alloantigen.

We characterized a platelet specific alloantigen (Yukb). In immunoblotting, anti-Yukb antibody was found to react with both 110 kDa and 96 kDa bands under nonreducing condition. Immunoblotting followed by separation by two-dimensional electrophoresis (isoelectric focusing/SDS-PAGE) showed that the 96 kDa band had a pI of 5.1-5.8, while the 110 kDa band had a pI of 5.2-5.7. The 96 kDa band was identified as glycoprotein (GP) IIIa on the basis of periodic acid Schiff staining, but the 110 kDa band was not characterized. These results implied that it is difficult to determine differences in antigenic epitopes between Yukb and PlA1 antigens by the electrophoresis. Yukb antigen, unlike PlA1 antigen, was partially destroyed by chymotrypsin treatment. Furthermore, endoglycosidase H digestion resulted in loss of the Yukb epitope, while the PlA1 determinant was retained on the three bands with lower molecular weights after endoglycosidase H digestion. The transfer of Yukb antigens recognized by anti-Yukb antibody into the supernatant of platelets treated with endoglycosidase H was also found using mixed passive hemagglutination test. The results indicated that the Yukb epitope might be located to the endoglycosidase H digested N-linked high mannose carbohydrate chains of GP IIIa or hybrid type chains of GP IIIa, which is different from the location of PlA1 epitope.

Antibodies↗
PubMed1992

High-level resistance to ethidium bromide and antiseptics in Staphylococcus aureus.

A gene encoding high-level resistance to ethidium bromide (EB) and antiseptics was isolated from a transferable plasmid, pTZ22, in Staphylococcus aureus. DNA sequencing revealed that the plasmid has two copies of the ebr gene that normally mediates low-level resistance to EB and antiseptics. The efflux rate for EB of strains with duplicated ebr genes was twice the rate of strains with a single ebr gene. It was concluded that the duplication of ebr is responsible for the high-level resistance to EB and antiseptics.

Amino Acid Sequence↗
PubMed1992

Chemical modification of the sugar part of methyl acarviosin: synthesis and inhibitory activities of nine analogues.

Nine analogues of methyl acarviosin (1), the core structure of acarbose and its homologues, the 6-hydroxy-(2), 6-azido-(3), 6-amino- (4), 6-acetamido-(5), 6-methoxy-(6), 6-hydroxy-2-O-methyl-(8), and 6-hydroxy-3-O-methyl derivatives (9), including the 5-methoxycarbonyl analogue (7) and 3,6-anhydro derivative (10) of 2, were synthesized by chemical modification of the sugar part of 2 derived by condensation of methyl 3,4-anhydro-alpha-D-galactopyranoside (17) and 4,7:5,6-di-O-isopropylidenevalienamine (26) or by direct coupling between 26 and the 6-substituted methyl 3,4-anhydro-alpha-D-galactopyranoside derivatives. Compounds 2 and 8 show notable inhibitory activity against yeast alpha-D-glucosidase almost comparable to that of 1. Introduction of a polar substituent at C-6 of 1 decreases the inhibitory activity. Interestingly, inversion of the conformation of the sugar part of 1 by introduction of the 3,6-anhydro bridge elicits almost no effect on the inhibitory activity.

Amino Sugars↗
PubMed1992

Regulation of phospholipase A2 activation and arachidonic acid metabolism in an interleukin-3-dependent macrophage-like cell line.

An interleukin 3 (IL-3)-dependent macrophage-like cell line, 11-1-B3, was newly established from CBA/J mouse bone marrow cell cultures. Assay of eicosanoids in the culture supernatants of the intact and [3H]arachidonic acid (AA)-prelabeled cells showed that, after stimulation with the Ca2+ ionophore A23187, the 11-1-B3 cells synthesized and released relatively large amounts of prostaglandin E2 (PGE2) and leukotriene B4 (LTB4) but not LTC4. In addition, 11-1-B3 cells showed Ca(2+)-dependent and alkaline pH-optimal phospholipase A2 (PLA2) activity that preferentially hydrolyzed cleavage of sn-2-arachidonyl- but not sn-2-oleoylphosphatidylcholine. The cellular enzyme was distributed with 90% of the activity in the cytosol and 10% in the membrane fraction. Treatment of cells with A23187 for 5-10 min resulted in five- to sevenfold increases in the membrane-associated PLA2 but activity in the cytosol was unchanged. This increase in membrane-associated enzyme activity was transient, returning to the pretreatment distribution after 30 min. In sharp contrast, phorbol myristate acetate (PMA) stimulation failed to induce either eicosanoid release or PLA2 activation, although PMA induced translocation of protein kinase C (PKC) to the membrane fraction within 10 min. The data suggest that increases in cellular Ca2+ directly activate membrane-associated PLA2 and consequently initiate AA metabolism; PKC activation by PMA requires additional steps to activate PLA2, a mechanism that is apparently deficient in the IL-3-dependent M phi-like cells.

Animals↗
PubMed1992

Exudation of proliferative macrophages in local inflammation in the peritoneum.

Thioglycollate (TG)-elicited peritoneal macrophages (m phi s) were highly proliferative and formed m phi colonies in vitro in the presence of m phi colony-stimulating factor (M-CSF), while resident peritoneal m phi s did not. To determine whether such proliferative m phi s are immigrant or locally activated resident m phi s, mice depleted of bone marrow cells and circulating monocytes by bone-seeking radiostrontium (89Sr) were injected intraperitoneally with TG. For control (88Sr) and splenectomized (Spx) mice, more than 4 x 10(4) m phi colony-forming cells (M-CFCs) per mouse were recovered in the peritoneal lavage fluid 5 days after TG injection. 89Sr-treated mice, on the other hand, had only 20% of those in the control mice. Splenectomized and 89Sr-treated (Spx/89Sr) mice showed further depletion of bone marrow cells and monocytes and, as expected, total numbers of peritoneal M-CFCs were severely depressed to less than 1% of those in the control mice. The results suggest that levels of peritoneal M-CFCs are strongly dependent on the presence of radiosensitive bone marrow cells and circulating monocytes, and resident peritoneal m phi s activated locally by inflammatory stimuli do not form m phi colonies under the defined conditions.

Animals↗
PubMed1992

Isolation and characterization of enzymes hydrolyzing chymotrypsin synthetic substrate (Enzyme I) and trypsin synthetic substrate (Enzyme II) from the envelope of Capnocytophaga gingivalis.

Enzymes hydrolyzing chymotrypsin synthetic substrate and trypsin synthetic substrate, referred to as Enzyme I and Enzyme II, respectively, were found in the envelope fraction of Capnocytophaga gingivalis (ATCC 33624). Detergent extraction of both enzymes were purified by gel filtration, ion exchange chromatography, and affinity chromatography. The Enzyme I was a serine-containing metallo enzyme with a molecular mass of 77 kDa. The molecular mass of the Enzyme II was 83 kDa, and it was inhibited by tosyl-L-lysine chloromethyl ketone and leupeptin, and thus may be related to trypsin.

Amino Acid Sequence↗
PubMed1992

Subcutaneous use of erythropoietin in heart surgery.

The effect of subcutaneous administration of recombinant human erythropoietin (rHuEPO) in ameliorating anemia resulting from autologous blood donation was compared with intravenous administration of rHuEPO. Forty patients undergoing coronary artery bypass procedures were divided into three groups. Group I (12 patients) received intravenous administration of rHuEPO (100 U.kg-1.day-1) and intravenous iron preparations for 14 days before operation; group II (14 patients) had subcutaneous administration of rHuEPO (600 U/kg) on preoperative days 14 and 7 and oral iron preparations for 14 days; and group III (14 patients) received oral iron preparations alone and served as the controls. Each patient predonated 800 mL of blood in the 2 weeks before operation. The reticulocyte count increased significantly in groups I and II (p less than 0.01), but little in group III. The hemoglobin level just before operation was higher in groups I (p less than 0.01) and II (p less than 0.05) compared with group III. Four patients (29%) in group III required homologous blood transfusion versus none in groups I and II (p less than 0.05). Subcutaneous administration of rHuEPO once a week was as effective as daily intravenous administration. Preoperative autologous blood donation can be performed over a short period on an outpatient basis with subcutaneous administration of rHuEPO.

Aged↗
PubMed1992

Stimulation by interleukin-1 of interleukin-6 production by human periodontal ligament cells.

Interleukin-1(IL-1), a cytokine present in the gingiva and crevicular fluid of patients with periodontitis and in the periodontal ligament (PDL) of experimentally moved teeth, has multiple biological activities, including the ability to elicit bone resorption. Interleukin-6, also found in the gingiva of patients with periodontitis, may induce osteoclastic bone resorption through an effect on osteoclastogenesis. Here IL-6 production and its gene expression in response to recombinant IL-1 beta were examined in primary cultures of PDL cells. IL-1 beta stimulated IL-6 production by these cells in a dose- and time-dependent manner; this increase in IL-6 production was much higher than that in human gingival fibroblasts. In situ hybridization, using a synthetic oligonucleotide DNA probe of the IL-6 gene, revealed that most PDL cells expressed IL-6 mRNA in response to IL-1 beta treatment. The finding that IL-6 is produced by PDL cells and is regulated by IL-1 beta has revealed a potentially important mechanism for controlling alveolar bone resorption.

Cells, Cultured↗
PubMed1992

Selenium and arsenic in biology: their chemical forms and biological functions.

Based on the recent development of analytical methods, sensitive systems for the analysis and speciation of selenium and arsenic have been established. A palladium addition technique was developed for the accurate determination of selenium in biological samples using graphite furnace atomic absorption analysis. For the speciation of the elements, combined methods of HPLC either with ICP-AES or with ICP-MS were found to work well. These systems were applied to the elucidation of the chemical form of the elements in natural samples. Some chemical properties of the selenium-mercury complex in dolphin liver were elucidated: i.e., it was a cationic, water-soluble, low molecular weight compound containing selenium and mercury in a 1:1 molar ratio, and was shown to be different from a known selenium-mercury complex, bis(methylmercuric)selenide. The major selenium compound excreted in human urine was revealed to be other than any of those previously identified (TMSe, selenate, and selenite). TMSe, a suspected major metabolite in urine, was found, if at all, in low levels. The major water-soluble, and lipid-soluble arsenic compounds in a brown seaweed, U. pinnatifida (WAKAME), were rigorously identified, and the results were compared with other data on marine algae and animals. The major organic arsenic compounds (termed "arseno-sugars") in marine algae commonly contain 5-deoxy-5-dimethylarsinyl-ribofuranoside moiety. There are various kinds of arseno-sugar derivatives containing different side-chains attached to the anomeric position of the sugar, and the distribution of each arsenic species seems to be related to algal species. The arseno-sugar (A-XI) is present in every alga so far examined, is metabolized to lipids, and possibly may play some specific role in the algal cells. On the other hand, the major arsenic compound in fish, crustacea and molluscs has been identified as arsenobetaine, which is an arseno-analog of glycinebetaine, a very common osmo-regulator in living organisms. Arsenobetaine is not detected in marine algae while arseno-sugars are not present in marine animals except for some molluscs which contain both compounds in considerable amounts. Arsenobetaine is present in the urine of human beings who have eaten foods derived from marine animals.

Animals↗
PubMed1992

Expression of blood group-related antigens, ABH, Lewis(a), Lewis(b), Lewis(x), Lewis(y), CA19-9, and CSLEX1 in early cancer, intestinal metaplasia, and uninvolved mucosa of the stomach.

The expression of blood group-related antigens, A, B, H type 2, Lewis type 1 (Lewis(a) [Le(a)] and Lewis(b) [Le(b)]), Lewis type 2 (Lewis(x) [Le(x)] and Lewis(y) [Le(y)]), sialylated Le(a) (CA19-9), and sialylated Le(x) (CSLEX1), was analyzed sequentially with immunohistochemical methods in early gastric cancer, intestinal metaplasia, and uninvolved gastric mucosa obtained from 35 surgical specimens of patients who underwent gastrectomy. The high incidence of the inappropriate expression of Lewis type 1 antigens and the deletion of H and Lewis type 2 antigens was observed similarly in patients with cancer and intestinal metaplasia. The acquisition of CA19-9 and CSLEX1 and the deletion of B antigen frequently were found in intestinal-type cancer and all types of intestinal metaplasia. The simultaneous deletion of A antigen was detected only in the combination of intestinal-type cancer and incomplete-type intestinal metaplasia. Thus the present study shows that similar changes of tissue antigenicities exist in early gastric cancer and intestinal metaplasia.

ABO Blood-Group System↗
PubMed1992

Effects of chronic oral administration of nifedipine and diltiazem on occlusive thrombus of small coronary arteries in (NZW x BXSB)F1 male mice.

OBJECTIVE: (NZWxBXSB)F1 male mice were used as a model to study the effects of chronic administration of nifedipine and diltiazem on small coronary artery disease and mortality. METHODS: 16 week old (NZWxBXSB)F1 male mice were given either nifedipine (n = 29) at 20 mg.kg-1.d-1 orally or diltiazem (n = 28) at 100 mg.kg-1.d-1 orally in two divided doses until they were 24 weeks old (ie, for 60 d). Age matched control mice were given an equivalent volume of vehicle (n = 30). Mice that died received immediate necropsy. After 60 d, all surviving mice were killed and hearts and kidneys were examined histologically. RESULTS: The survival rate at 24 weeks was significantly higher in mice given nifedipine than in the controls (71% and 47%, respectively, p less than 0.05). The number of mice with myocardial necrosis, scar formation, or both, the percentage of areas of the ventricular wall with myocardial necrosis and scar formation, and the number of mice with small intramyocardial arteries showing greater than or equal to 75% stenosis were all significantly lower in the mice given nifedipine than in the controls. In the mice given diltiazem, there were no such differences from the controls. There was no evidence of significant stenosis or thrombosis in the extramyocardial coronary arteries in any of the mice. Systolic blood pressure and the rate-pressure product at 24 weeks of age, as well as the histological score for glomerulonephritis changes, were significantly lower in mice given nifedipine or diltiazem than in the controls. CONCLUSIONS: Despite an equivalent improvement of systolic blood pressure, the double product, and renal disease in nifedipine treated and diltiazem treated mice, only nifedipine prevented small coronary artery disease and increased the survival of (NZWxBXSB)F1 male mice, suggesting that nifedipine prevents occlusive thrombi of small coronary arteries better than diltiazem.

Administration, Oral↗
PubMed1992

Structural studies of peptidoglycans in Campylobacter species.

Peptidoglycans (PG) from Campylobacter coli, Campylobacter jejuni, and Campylobacter fetus were composed of muramic acid, glucosamine, alanine, glutamic acid, and diaminopimelic acid in a molar ratio of 1.1:1:1.7:1.1:09. Thirty percent of the amino groups of diaminopimelic acid were involved in cross-linkages between peptides. During cultivation, C. coli and C. jejuni changed from a spiral to a coccoid form. In C. coli, we could isolate PG only from the spiral forms in yields of 0.8-1.2% by dry weight. C. fetus did not change to a coccoid form, and always contained PG. Thus, it is possible that the morphological transformation from the spirals to the coccoid forms of C. coli and C. jejuni is accompanied by, and probably due to, the degradation of PG.

Campylobacter↗
PubMed1992

Comparative studies of three proteases of Porphyromonas gingivalis.

Three thiol-activated proteases, designated Qa, Ra, and Sa, in the soluble fraction of the cell extract of Porphyromonas gingivalis ATCC 33277 were purified by combinations of gel filtration, ion exchange chromatography and electrophoresis, and characterized. The molecular weights estimated by gel filtration method were 43 kDa (Sa), 87 kDa (Ra), and 170 kDa (Qa). However, they were found to have the same molecular weight (43 kDa), when estimated by SDS-PAGE, indicating that Sa is a monomeric, Ra is a dimeric and Qa is a tetrameric form. The 3 enzymes showed quite similar biochemical properties, and they could degrade not only the synthetic substrates but immunoglobulins, fibrinogen and albumin.

Bacterial Proteins↗
PubMed1992

Isolation and properties of the Capnocytophaga ochracea bacteriocin.

A bacteriocin from a subgingival plaque isolate of Capnocytophaga ochracea was purified and characterized. It was isolated from cell extract and had a molecular weight of 100,000. Streptococcus sanguis, Streptococcus mitis, Streptococcus mutans and Propionibacterium acnes were susceptible to the bacteriocin.

Actinomyces↗
PubMed1992

Protein p67. A calcium-binding protein localized at the sarcolemma of secretory atrial myocytes.

Bovine heart 67-kd protein (p67) was coisolated with calpactin I complex by cycles of Ca(2+)-dependent precipitation followed by solubilization with EGTA-containing buffer. Using affinity-purified anti-p67 antibody and anti-p36 (36-kd subunit of calpactin I) antibody, we examined the localization of the two proteins in secretory atrial myocytes and other endocrine tissues of adult rats. Immunofluorescence microscopy showed that p67 was expressed both in the atrial myocytes in situ and in cultured atrial myocytes in which we failed to detect p36 and that p67 appeared to be closely associated with the cell surface. We also found that p67 was colocalized with p36 in the thyroid follicle epithelium and zona reticularis of the adrenal gland. On the other hand, neither p67 nor p36 was detectable in pancreas islet cells. Immunoelectron microscopy revealed that p67 was localized at the sarcolemma in the atrial myocytes in situ. The p67, which was shown to be a globular molecule with a diameter of 18-25 nm by a low-angle rotary shadowing method, bound radioactive Ca2+ on a nitrocellulose membrane. The results suggest that Ca(2+)-binding proteins expressed in endocrine cells seem to vary from tissue to tissue and that p67 may function in Ca(2+)-mediated events at the plasma membrane of secretory atrial myocytes and some types of endocrine cells expressing this protein.

Amino Acids↗
PubMed1992

Light microscopic immunohistochemical analysis of the distribution of group II phospholipase A2 in human digestive organs.

The light microscopic and immunohistochemical distribution of human Group II phospholipase A2 (M-PLA2) in digestive organs of both human fetus and adult, with a new monoclonal antibody (MAb) against M-PLA2, was investigated semiquantitatively. The immunoreactivity was distributed similarly in the adult and fetal epithelium of the esophagus, duodenum, and small intestine, and in the acinar, islet, and duct cells of the pancreas. The epithelium of adult gallbladder was immunoreactive. Paneth cells, especially the secretory apparatus, were strongly immunoreactive. Hepatic Küpffer cells and macrophages of the adult spleen were also immunoreactive. These results suggest that these cells contain secretory-type Group II PLA2, which may be involved in host defensive mechanisms, such as phagocytosis in human digestive organs. In the adult colon, the immunoreactivity was observed only in the ascending colon and was not found in the transverse, descending, sigmoid, or rectal colon. The immunoreactivity was not found in fetal colon. Similarly, immunoreactivity was found in hepatocytes and Küpffer cells of adult liver but not in fetal liver. By contrast, strong immunoreactivity was observed in the epithelium of the fetal stomach but not in adult stomach except in gastric neck cells. This suggests that the expression of M-PLA2 may be related to cell differentiation in particular organs.

Adult↗