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Biomedical subjects

S Shibata

Publications and source records attributed to S Shibata.

At least 739 records · Page 41Linked to original sources
PubMed1984

Nephritogenic glycoprotein X. Correlation between the purity of nephritogenic glycopeptide, nephritogenoside, and morphological manifestation of glomerulonephritis.

When triglycosyl glycopeptide ( nephritogenoside ) was contaminated with glucosyl, galactosyl, mannosyl, and heteropolysaccharide glycopeptide, a mixed lesion of proliferative glomerulonephritis ( PGN ) with immunofluorescent mesangial pattern and membranous glomerulonephritis (MG) with immunofluorescent granular pattern resulted. It was concluded that PGN was caused by the presence of nephritogenoside and MG by the presence of the heteropolysaccharide glycopeptide in the crude nephritogenic glycopeptide mixtures derived from various solubilization steps used to treat the kidney extracts. Trichloroacetic acid treatment of crude nephritogenic glycopeptide mixtures precipitated the heteropolysaccharide glycopeptide of the MG-inducing factor, thus permitting the separation of nephritogenoside from the heteropolysaccharide glycopeptide by a rather simple technique. Both the heteropolysaccharide glycopeptide and Heymann's antigen (so-called tubular antigen) have a common antigenic substance, but we cannot conclude, at the present state, that both substances are chemically the same. The degree of contamination of pure nephritogenoside by this substance that is antigenically the same as Heymann's antigen (in pure nephritogenoside ) can be chemically and accurately determined, based on the evidence that pure nephritogenoside is a glycopeptide having only three glucose residues as the sugar moiety, that is, by estimating the amount of contaminated monosaccharide components such as galactose, mannose, and N-acetylglucosamine.

Animals↗
PubMed1984

Behavioral effects of brotizolam, a new thienotriazolodiazepine derivative.

The behavioral effect of brotizolam was investigated in mice and rats, in comparison with those of diazepam, nitrazepam and estazolam. Locomotor activity of rats in an open field situation was slightly increased with smaller doses of brotizolam and estazolam and with larger doses of nitrazepam, while it was decreased with large doses of brotizolam and estazolam. The anticonflict effect of brotizolam in rats was approximately as potent as that of diazepam and was augmented following chronic administration for 10 days. In suppressing hyperemotionality and muricide of olfactory bulbectomized rats, brotizolam was more potent than diazepam, being approximately equipotent to nitrazepam and estazolam. Brotizolam, diazepam, nitrazepam and estazolam prevented both maximal electroshock and pentetrazol convulsions in mice, the effects on the latter being much more potent than those on the former. In impairing rotarod performance, brotizolam was as potent as estazolam and nitrazepam and was much more potent than diazepam in mice, but was less potent than estazolam and nitrazepam in rats. These results indicate that brotizolam possesses pharmacological properties characteristic to benzodiazepines and that the activity is more potent than that of diazepam and approximately as potent as those of nitrazepam and estazolam.

Aggression↗
PubMed1984

[Observations on mortality in selected working populations].

Mortality among employees of selected enterprises in which excellent health care programmes are carried on, was observed to evaluate employees' health levels and to establish objectives for future health care programmes. Also, these data were compared with those for all Japanese and for Japanese employees belonging to the corresponding occupational groups. Seventy-three enterprises which continuously participated in the mortality survey implemented by the Japan Research Organization of Industrial Health Care for the period between 1976 and 1980, were subjected to this study. The observed employees amounted to 3,502,580 person-years. Sex and age distributions of the employees were available for 47 enterprises and the observed employees totalled 2,598,672 person-years. The main results are as follows: Mortality rate (per 100,000) is stable between 140 and 150 throughout the observed period and the average value is 145.0. The average mortality rate for males, aged 40 to 54, is 272.6. Malignant neoplasms were the main cause of death and account for 37-38%. In second place and below are heart diseases, cerebrovascular diseases, accidents, suicide and liver cirrhosis. Malignant neoplasms, especially of the stomach, lung and pancreas, show a trend to increase, and cerebrovascular diseases and liver cirrhosis show a trend to decrease. Among heart diseases, ischemic heart disease accounts for about 40% and shows no marked fluctuation. Among cerebrovascular diseases, the relative frequency of subarachnoid hemorrhage is increasing. Comparing the mortality rates for males aged 40 to 54 by industry, "Iron, steel & nonferrous metal manufacturing" and "Electricity and gas supply" show significantly higher values, and "Finance & insurance" and "Communications" show significantly lower values than the total. The distribution of main causes of death for males, aged 40 to 54, was compared by major occupational groups using Proportional Mortality Ratio (PMR). A significantly high frequency of malignant neoplasms (especially of the stomach) is observed for "Professional & technical workers, managers and officials" and that of suicide for "Craftmen, production process workers and labourers" and that of cerebrovascular diseases (especially cerebral hemorrhage) for "Protective service workers." Standardized Mortality Ratio (SMR) for males, aged 20 to 54, from all causes of death, calculated on the basis of all Japanese males in 1978 is 0.57. SMR for this population from malignant neoplasms is 0.89.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1984

Conformational differences between mouse contrapsin and alpha-1-antitrypsin as studied by ultraviolet absorption and circular dichroism spectroscopy.

We have compared the conformation of mouse contrapsin , a novel trypsin inhibitor ( Takahara , H. and Sinohara , H. (1982) J. biol. Chem., 257, 2438-2446), and alpha-1-antitrypsin by UV absorption and CD spectroscopy. The two mouse inhibitors share a similar secondary structure, i.e., 24-29% alpha-helix, 31% beta-sheet, and 10-11% beta-turn. The corresponding values for human alpha-1-antitrypsin are 48, 25, and 9%, respectively. These results suggest that peptide backbone structures of the two mouse inhibitors resemble each other, but differ slightly from that of human alpha-1-antitrypsin. On the other hand, evidence is accumulated that the microenvironments of aromatic side chains are considerably different in mouse contrapsin and alpha-1-antitrypsin: (i) An unusual fine vibrational structure was seen in the UV absorption spectra of murine and human alpha-1- antitrypsins , but not in that of contrapsin . (ii) CD bands in contrapsin which may be assigned to phenylalanyl residues were several-fold greater in intensity than those in the two alpha-1- antitrypins . (iii) The above-mentioned bands in contrapsin were more susceptible to pH changes than those in alpha-1-antitrypsin. (iv) CD bands in contrapsin which may contain unresolved contributions from tyrosyl and tryptophanyl residues also markedly differed from those in the two alpha-1- antitrypsins . These differences were, however, largely diminished in the presence of 50 mM sodium dodecyl sulfate, suggesting that mouse contrapsin and alpha-1-antitrypsin have a similar structure in the presence of this perturbant .

Animals↗
PubMed1984

[Nephritogenic glycoprotein isolated from human placenta--purification and isolation by sonication].

Previously, we reported that we succeeded in isolating from human placenta a substance comparable to human renal nephritogenic glycoprotein prepared from glomerular basement membrane (GBM). This time we purified a sample isolated from human placental trophoblast basement membrane (TrBM) with the methods for purifying renal nephritogenic glycoprotein and clarified its chemical composition. To purify the sample prepared from human placental TrBM, we fractionated the sample by Zone Electrophoresis, Concanavalin A(Con A) affinity column chromatography and Bio Gel P200 column chromatography. As the active fraction of the sample purified from human placental TrBM bound specifically with Con A, it proved to be a glycoprotein. The monosaccharide composition of this glycoprotein was rich in glucose (glucose, galactose and mannose were in the ratio of 1.00:0.30:0.33) and the amino acid composition of this glycoprotein contained no collagenous components. Ouchterlony gel diffusion demonstrated the existence of a common precipitin line between antiserum to human renal nephritogenic glycoprotein prepared from GBM and human renal nephritogenic glycoprotein prepared from GBM, purified human placental glycoprotein, the sample prepared from human placental TrBM by sonication and nephritogenic glycoprotein prepared from urine of S.L.E. patient.

Amino Acids↗
PubMed1983

Development of the circadian rhythm of neuronal activity in suprachiasmatic nucleus of rat hypothalamic slices.

Development of the circadian rhythm of neuronal activity in the suprachiasmatic nucleus (SCN) was studied in rat hypothalamic slices. The firing rate of SCN neurons of 7- and 11-day-old rat pups was low during all of the day, whereas that of 14- and 21-day-old pups was high during daytime and low during nighttime. The present results suggest that the circadian rhythm of SCN neuronal activity is established between 11 and 14 days of age, corresponding closely to the time of onset of the other various hormonal and behavioral circadian rhythms.

Age Factors↗
PubMed1983

Inhibitory and excitatory effects of histamine on suprachiasmatic neurons in rat hypothalamic slice preparation.

The effects of histamine (HA) and serotonin (5-HT) on single neurons of the suprachiasmatic nucleus (SCN) in hypothalamic slices were investigated by iontophoretic application. Sixty-two of 181 cells were inhibited by HA, whereas 30 were excited. Forty-nine of 163 cells were inhibited by 5-HT, whereas 9 were excited. Pyrilamine, an H1-antagonist, slightly (2/7), and cimetidine, an H2-antagonist, strongly (10/13) antagonized the inhibitory effect of HA. The excitatory effect of HA was not antagonized by cimetidine (0/4), but was perfectly antagonized by pyrilamine (5/5). The present results suggest that HA and 5-HT play mainly an inhibitory role in the SCN neuronal activity, and that inhibition and excitation induced by HA may be mediated by H2- and H1-receptors, respectively.

Animals↗
PubMed1983

Different effects of amino acids, acetylcholine and monoamines on neuronal activity of suprachiasmatic nucleus in rat pups and adults.

A study was undertaken of the effects of iontophoretically applied amino acids, acetylcholine and monoamines on suprachiasmatic nucleus (SCN) neurons of rat pups, at the 11th postnatal day, using a hypothalamic slice preparation. GABA and taurine inhibited 97 and 42% of SCN neurons, respectively, while glycine had no effect. Glutamate excited 68% of them. These effects were similar to those in adult rats. Serotonin and noradrenaline inhibited 6 and 10% of SCN neurons, respectively, in rat pups, whereas 32 and 26% of them were inhibited in adult rats. Acetylcholine excited 7% but inhibited 26% of SCN neurons in rat pups and these values were almost the same as those of adult rats. These results reveal that acetylcholine and amino acids regulate SCN neurons even in rat pups, whereas monoamines play an important regulatory role in SCN activity in adult rats only.

Acetylcholine↗
PubMed1983

Structure of a water-insoluble D-glucan isolated from a streptococcal organism.

The structure of the extracellular polysaccharide (water-insoluble D-glucan) from an anaerobic, Gram-positive coccus organism (Streptococcus) has been investigated. Acid hydrolysis of the methylated glucan yielded 2,3,4,6-tetra-, 2,3,4-tri-, 2,4,6-tri, and 2,4-di-O-methyl-D-glucose in the molar ratios of 1.13:3.99:1.00:1.02, indicating that the D-glucan has a branched structure containing (1 leads to 6)- and (1 leads to 3)-alpha-D-glucosidic bonds with an average repeating unit of seven sugar residues. The D-glucan-polyalcohol, derived by successive periodate oxidation and borohydride reduction, gave, on complete hydrolysis with acid, glycerol and D-glucose (molar ratio, 2.2:1.0). Methylation of the D-glucan-polyalcohol yielded, upon hydrolysis, 2,4,6-tri-, and 2,4-di-O-methyl-D-glucose (molar ratio, 1.0:1.1). Methylation of the D-glucan-polyalcohol following Smith degradation (mild acid hydrolysis) gave 2,4,6-tri-O-methyl-D-glucose as the principal hydrolysis product, in addition to a trace of 2,3,4,6-tetra-O-methyl-D-glucose.

Carbohydrate Conformation↗
PubMed1983

Palytoxin isolated from marine coelenterates. The inhibitory action on (Na,K)-ATPase.

Palytoxin (PTX), C129H223N3O54, a highly toxic substance isolated from zoanthids of Palythoa tuberculosa, inhibited (Na,K)-ATPase (ATP phosphohydrolase, EC 3.6.1.3) prepared from guinea pig heart and hog cerebral cortex in a dose-dependent manner at concentrations greater than 10(-8) M. In the presence of Na (100 mM) and K (20 mM), PTX showed potency nearly equal to that of ouabain. When the ATPase was activated by the various Na concentrations at a constant K concentration, both PTX and ouabain inhibited the ATPase activity noncompetitively. On the other hand, when K concentration was changed at a constant Na concentration, PTX caused a competitive inhibition in all ranges of K concentrations employed, whereas ouabain caused a competitive inhibition at low concentrations and a noncompetitive inhibition at high concentrations.

Acrylamides↗