Search PubMed⌕ Search

Biomedical subjects

M Hashimoto

Publications and source records attributed to M Hashimoto.

At least 1,225 records · Page 68Linked to original sources
PubMed1977

A novel and simple colorimetric assay for human serum lipase.

A new and simple colorimetric method for human serum lipase [EC 3.1.1.3] assay has been developed, using 2,3-dimercaptopropan-1-ol tributyroate as a substrate, 5,5'-dithiobis(2-nitro-benzoic acid) as a chromogenic reagent, phenylmethylsulfonyl fluoride as an inhibitor of serum esterases, and sodium dodecylsulfate as a lipase activator. The method requires only 50 micron1X2 of serum sample and a reaction time of less than 30 min. The method is reproducible and sensitive enough to measure low levels of lipase activity in normal and abnormal sera. The gel filtration of serum samples on a Sephadex G-200 column gave one peak of lipase activity, when measured by the present method, and the molecular weight of the enzyme was identical with that of lipase of human pancreatic origin, confirming the specificity of this new method for the serum lipase.

Chromatography, Gel↗
PubMed1977

Studies on the neutralization of herpes simplex virus. VIII. Significance of viral sensitization for inactivation by complement.

Early and late IgG of rabbits immunized with herpes virus showed, respectively, 8-fold and 2-fold enhancement of neutralization endpoint in the presence of complement (C). Kinetic curve experiments employing an appropriate amount of virus revealed that both neutralization and sensitization followed first-order reaction, and each IgG possessed a certain range of concentration where neutralization was negligible while sensitization was marked. Dose responses of neutralization and sensitization velocities demonstrated that the C enhancement of late IgG was about 7-fold and that of early IgG more than 20-fold. These facts suggested that the IgGs contained two different entities of complement-requiring (CRN) and non-requiring neutralizing (N) antibodies at different proportions, only the former being responsible for sensitization. The different CRN: N ratios obtained by the endpoint and kinetic methods may mean either that the two antibodies differ in avidity for the virus or that the number of critical sites per virion for CRN antibody is greater than that for N antibody. In this interpretation, sensitization by CRN antibody as well as neutralization by N antibody is thought to result from attachment of a single antibody molecule to the viral critical site. Alternative explanations, ascribing the mechanism of neutralization to steric hindrance of critical sites or to multiple hit of those sites by antibody, were denied by analyses of the present data.

Antibodies, Viral↗
PubMed1977

Development of an enzyme-linked receptor assay (ERA) for hCG.

An enzyme-linked receptor assay (ERA) for hCG was developed using horseradish peroxidase. The 1,500 g pellets, interstitial cell fraction, and solubilized homogenate from the rat testis linked to tanned sheep red blood cells (SRBC) were used as the binding fractions for hCG. In these ERA systems, the limit of detection for hCG was 30 IU/l (3-12 mIU/tube), which was almost equal to that of radio receptor assay (RRA). The ERA using SRBC linked solubilized receptor fraction showed the most satisfactory result in accuracy, reproducibility and easiness.

Animals↗
PubMed1977

Antibody to hepatitis B core antigen in patients with hepatocellular carcinoma.

Hepatitis B surface antigen (HBsAg), anti-HBs, and anti-HB core (HBc) were measured in 124 patients with hepatocellular carcinoma (HCC) in comparison with 299 control subjects of comparable ages, and in 48 cases of chronic hepatitis and 52 cases of hepatic cirrhosis. It was found that 72.6% of the HCC patients were positive for anti-HBc, and 80.6% were positive for at least one test, whereas in the control, anti-HBc was positive in 30.1% and 34.1% were positive for at least one test, the differences between the two groups being significant (P less than 0.01). The frequencies of positive tests for HBsAg and anti-HBc were the highest in HCC followed in decreasing order by cirrhosis, chronic hepatitis and the control group. A possible role of HB virus infection in hepatocellular carcinoma is discussed in relation to other factors.

Adult↗
PubMed1977

[Absorption, distribution, excretion and metabolism of SC-11800EE, a combined steroid preparation of SC-11800 (ethynodiol diacetate) and ethinyl estradiol in rats and mice (author's transl)].

Absorption, distribution, excretion and metabolism of SC-11800EE, a combined steroid preparation consisting of SC-11800(ethynodiol diacetate)as gestagen and ethinyl estradiol (EE)as estrogen in 20:1 (w:w), were studied with the use of 14C-SC-11800 and 3H-EE by radiometry in female rats and by the whole body autoradiography in female normal and pregnant mice. The gestagen orally given with EE was rapidly absorbed from digestive tracts and distributed in tissues in various levels. Gestagen levels in liver and kidney exceeded that in plasma. About 75% of dosed radioactivity was excreted in feces largely via bile and more than 20% in urine within 72 hr after administration. The gestagen was metabolized extensively to more polar products and their conjugates. The pharmacokinetic behavior of the gestagen given with EE did not alter after repeated administrations for 7 days, but was slightly different from that without EE, possibly due to the estrogen effect. The pharmacokinetic behavior of the estrogen was independent from the gestagen given simultaneously. The distribution of the gestagen given with EE revealed by the whole body autoradiography in normal mice were essentially consistent with the radiometric results in rats and that in the pregnant mice showed that the gestagen in fetus was virtually nil under the present conditions.

Animals↗
PubMed1976

Relationship between the structures of S-acyl thiol compounds and their rates of hydrolysis by pancreatic lipase and hepatic carboxylic esterase.

About 100 S-fatty acyl thiol compounds designed as substrates for pancreatic lipase [EC 3.1.1.3] were synthesized and tested for susceptibility to hydrolysis by hog pancreatic lipase and hog hepatic carboxylic esterase [EC 3.1.1.1] using 5,5'-dithiobis(2-nitrobenzoic acid) as a chromogenic reagent to determine the hydrolytic rates of their S-acyl bonds. In general, the hydrolytic rates of S-acyl bonds by the lipase were fast with thioglycerol type thiol moieties, slow with dithioethyleneglycol type or monothiol type, and negligible with thiopolyol type. As for the acyl moieties, the hydrolysis of the S-acyl bonds was fast with C3-5 acyl groups, followed by C6-8 acyl groups, and the rate decreased as the acyl chain length deviated from these values or branched. On the other hand, the hydrolysis of S-acyl bonds by the esterase occurred with all types of S-acyl esters except for esters of long S-acyl chains. Of all the compounds tested with the lipase, the rate of hydrolysis of S-acyl bond was maximum with 2,3-dimercaptopropan-1-ol tributyroate [I], high with 3-mercaptopropane-1,2-diol tributyroate [II], but negligible with the analogous compound, 1,3-dimercaptopropan-2-ol tributyroate. Compounds [I] and [II] may be practically useful as substrates for lipase assay in human serum samples pretreated with phenylmethylsulfonyl fluoride, a potent inhibitor against both serum arylesterase [EC 3.1.1.2] and hepatic esterase, which attack [I] and [II].

Alcohols↗
PubMed1976

Alteration of the in vitro host range of rabies virus after serial chick embryo cell passage using alkaline maintenance medium.

HEP Flury strain of rabies virus maintained by 7-day chicken egg passage (parent line) and the same strain serially passaged in primary chick embryo (CE) cells using alkaline maintenance medium (AM line) were inoculated to cells of various species. Growth was negative in primary mouse embryo, L and HeLa cells, and positive in primary hamster kidney and BHK21 cells with both lines. An all-or-none difference between the two lines was observed in primary monkey kidney and Vero cells. The parent line did not multiply in these monkey cells, whereas the AM line grew to high titers. In the case of Vero cells a unique cytopathic effect (CPE) was induced by the AM line. After five consecutive passages in Vero cells, the CPE-inducing agent was identified as rabies virus by a neutralization test. It was infective to intracerebrally inoculated suckling mice but not to adult mice, and its Vero cell-infective titer determined by CPE induction was about 1 log lower than the baby mouse-infective and CE plaque-forming titers. In contrast to the AM line, HEP Flury strain receiving 150 CE cell passages under neutral maintenance medium and three other strains receiving similar CE cell passages all failed to grow in Vero cells.

Animals↗