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Biomedical subjects

S Shimada

Publications and source records attributed to S Shimada.

At least 415 records · Page 23Linked to original sources
PubMed1982

Rapid changes of serum vasoactive intestinal peptide after removal of ganglioneuroblastoma with watery-diarrhea-hypokalemia-achlorhydria syndrome in a child.

A 23-month-old girl with intractable diarrhea that had persisted for the past 6 months showed typical evidence of water-diarrhea-hypokalemia-achlorhydria (WDHA) syndrome. Serum vasoactive intestinal peptide (VIP)-like immunoactivity was very high, and urine homovanillic acid and noradrenaline were also abnormally increased. A calcified tumor in the right paravertebral region was noted radiologically. Soon after resection of the tumor, the diarrhea dramatically improved. A ganglioneuroblastoma was histologically confirmed. Serum VIP decreased to normal level at 1 h after the removal of the tumor. VIP activity in the tumor was extraordinarily high, and the cells were stained by the indirect immunofluorescence technique with anti-VIP serum. This is to report the rapid turnover of serum level of VIP after resection of ganglioneuroblastoma with WDHA syndrome in a child.

Achlorhydria↗
PubMed1982

Antiviral activity of sodium 5-aminosulfonyl-2,4-dichlorobenzoate (M12325).

Sodium 5-aminosulfonyl-2,4-dichlorobenzoate (M12325) was evaluated for antiviral activity in tissue culture and infected mice. At concentrations ranging from 2.5 to 75.8 micrograms/ml, M12325 inhibited the cytopathic effects of 10 mean tissue culture infective doses of influenza virus A/WSN, A/FM, A/Kumamoto, and B/Great Lakes; parainfluenza virus; rhinovirus; echovirus; respiratory syncytial virus; and vesicular stomatitis virus. Concentrations up to 150 micrograms/ml did not inhibit the cytopathic effects of herpes simplex virus, vaccinia virus, or adenovirus. Concentrations up to 3,160 micrograms/ml did not inhibit the growth of MDCK, Vero, or HEL cells in culture. Single oral doses of M12325, ranging from 10 to 300 mg/kg, administered 1 h before and 1 h after challenge, reduced mortality in mice inoculated intranasally with influenza A/WSN virus. Twice daily oral doses for 14 days effected significant reductions in the mortality of mice infected intranasally with influenza A/WSN, A/FM, A/Kumamoto, and B/Great Lakes, and parainfluenza virus, but they were not effective in mice infected with herpes simplex virus. Multiple doses of 10 and 30 mg/kg, administered intraperitoneally, reduced lung consolidation and virus titer. M12325 was well tolerated in multiple doses up to 1 g/kg orally. These observations support the conclusions that M12325 has a broad spectrum of activity against RNA viruses in vitro and in vivo, selective toxicity, and a large margin of safety.

Amantadine↗
PubMed1981

beta-lactamase from Streptomyces cacaoi. Purification and properties.

A beta-lactamase was purified to an apparently homogeneous state from Streptomyces cacaoi. The molecular weight calculated from the mobility in sodium dodecyl sulfate polyacrylamide gel electrophoresis was 34,000. pI was 4.7 and the optimal pH was 6.5. The optimum temperature was found to be between 40 degrees C and 45 degrees C, but the enzyme lost activity above 50 degrees C. N-Bromosuccinimide was the strongest inhibitor among the reagents tested, followed by iodine. p-Chloromercuribenzoate showed a weak inhibitory effect. Diisopropylfluorophosphate and sodium chloride did not show any inhibitory effect on the enzyme. The beta-lactamase catalyzed the hydrolysis of methicillin and cloxacillin at two-thirds to one-third the rate of benzylpenicillin. On the other hand, the enzyme hydrolyzed cephalosporins and 7-methoxycephalosporin only slowly. With benzylpenicillin as a substrate, the Km increased sharply with decreasing pH and the pK alpha estimated from the Km versus pH curve was 6.5 to 7.0. In contrast, with cloxacillin as a substrate, the Km showed a minimum at pH 7.5. The Vmax changed with pH in a bell-shaped curve in the case of benzylpenicillin, but the Vmax for cloxacillin changed only within a small range. In addition, the ratio of the hydrolysis rate of benzylpenicillin and cloxacillin at 30 degrees C and 20 degrees C (V30 degrees/V20 degrees) was found to be 1.23 and 1.55, respectively. These results indicate that the S. cacaoi beta-lactamase behaves differently toward benzylpenicillin and cloxacillin, although both are penicillins. S. cacaoi seems to release beta-lactamase into the culture medium soon after its biosynthesis without retaining it in the membrane and the soluble fraction. The possible relationships between beta-lactamases from Streptomyces and those from pathogenic bacteria are discussed.

Hydrogen-Ion Concentration↗
PubMed1981

Soluble and particle-bound trehalase in the silk glands during larval-pupal development of the silkworm, Bombyx mori.

Trehalase localization in silk glands of the silkworm, Bombyx mori has been studied during larval-pupal development. Subcellular distribution of the silk gland trehalase depends upon larval-pupal development. The activity increases in the soluble fraction with a concomitant decrease in the particle-bound fraction during larval-pupal development. The pH-optimum value of trehalase activity in the particle-bound fraction changes from 6.5 to 6.0, and in the soluble fraction from 5.5 to 4.5 in the course of the silk gland degeneration during metamorphosis.

Animals↗