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Biomedical subjects

A Yamaoka

Publications and source records attributed to A Yamaoka.

15 recordsLinked to original sources
PubMed1979

Radioimmunoassay for pyrazolone derivatives.

The determination of pyrazolone derivatives by radioimmunoassay has been reported. Anti-antipyrine antisera were obtained by repeated immunization of rabbits with 4-azoantipyrine-conjugated bovine serum albumin. The level at least as low as 1.0 ng of antipyrine could be detected by this procedure. Various substituents on the carbon 4 position of the pyrazolone ring as well as the lack of methyl group on the nitrogen 2 position decreased the affinity for the antibody, and the antibody showed no cross-reaction with any pyrazolidine derivatives.

Ampyrone↗
PubMed1979

Determination of phenobarbital by radioimmunoassay.

A radioimmunoassay for phenobarbital has been studied. Antiphenobarbital antisera were obtained by repeated immunization of rabbits with p-succinamidophenobarbital conjugated to bovine serum albumin. Less than 0.2 pmol of phenobarbital could be measured by this procedure. The specificity of the antibodies was directed to substituents on the nitrogen atoms of the barbituric ring as well as to substituents at the carbon 5-position of the ring.

Antibody Formation↗
PubMed1979

Effects of phenylmethylsulphonylfluoride on activities of cholesteryl ester synthesis and hydrolysis in testes of rats, and on serum testosterone and LH levels.

PMSF was injected subcutaneously to male rats once a day for 10 days at a dose of 10 mg/day. There was an increase in the concentrations of free and esterified cholesterol in the testes, a decrease in activities of cholesteryl ester synthesis and hydrolysis but no change in activity of cholesterol side-chain cleavage enzyme. Serum testosterone and LH levels were significantly decreased. The only effect of PMSF on the lipids of the testes was a marked elevation of docosapentaenoic (22:5) acid and the cholesteryl esters.

Animals↗
PubMed1978

Effects of prostaglandins on the metabolism of cholesteryl ester in rat testes: changes in the synthesis and hydrolysis of cholesteryl ester and the activity of cholesterol side-chain cleavage enzyme.

The effects of prostaglandins on testicular synthesis and hydrolysis of cholesteryl esters, the activity of the enzyme involved in cleavage of the cholesterol side-chain and on serum levels of testosterone and LH have been studied. Subcutaneous administration of prostaglandins to male rats caused an increase in the concentration of cholesteryl esters in the testes, a decrease in testicular synthesis and hydrolysis of cholesteryl esters but no change in the activity of the cholesterol side-chain cleavage enzyme. There was also a significant decrease in the serum level of testosterone, but the level of LH was raised. Prostaglandins also affected the fatty acid composition of lipids in rat testicular tissue; cholesteryl esters were found to contain greater amounts of arachidonic (C20:4) and docosapentaenoic (C22:5) acids. These findings suggest that prostaglandins are involved in the turnover of cholesteryl esters in rat testicular tissue and regulate the production of androgens.

Animals↗
PubMedDate not supplied

The mechanism of adipocere formation 1. Identification and chemical properties of hydroxy fatty acids in adipocere.

The hydroxy fatty acid purified from the adipocere, m.p. 78.5 degrees -79.0 degrees C, was optically inactive and the adipocere contained about 3 to 20% hydroxy fatty acid of the total fatty acids. The melting point of the hydroxy fatty acid was nearly identical with that of the 10-D, L-hydroxyoctadecanoic acid synthesized organically, suggesting that the hydroxy fatty acid in the adipocere appears to be converted non-enzymatically. In the adipocere two hydroxy fatty acid components were detected by gas-liquid chromatography (GLC). The major and minor components were identified as 10-hydroxyoctadecanoic and 10-hydroxyhexadecanoic acids, respectively, by gas chromatography-mass spectrometry (GC-MS). These hydroxy fatty acids found in the adipocere appear to play an important role on the formation of adipocere.

Adipose Tissue↗
PubMedDate not supplied

Separation and identification of 9-chloro-10-methoxy (9-methoxy-10-chloro)hexadecanoic and octadecanoic acids in adipocere.

Two homologs of 9-chloro-10-methoxy(9-methoxy-10-chloro) fatty acids were found in adipocere from the human neonate, and identified as 9-chloro-10-methoxy(9-methoxy-10-chloro)hexadecanoic acid and 9-chloro-10-methoxy(9-methoxy-10-chloro)-octadecanoic acid. The chemical structures of these compounds were confirmed by thin-layer chromatography, gas-liquid chromatography, gas chromatography--mass spectrometry, nuclear magnetic resonance spectrometry and elemental analysis. The adipocere contained approximately 7.2% 9-chloro-10-methoxy(9-methoxy-10-chloro) fatty acids in the total fatty acids.

Chromatography, Gas↗