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Biomedical subjects

A Watanabe

Publications and source records attributed to A Watanabe.

At least 1,009 records · Page 56Linked to original sources
PubMed1981

Impaired metabolism of azathioprine in carbon tetrachloride-injured rats.

The metabolism of 6-(1-methyl-4-nitro-5-imidazolyl) thiopurine (azathioprine) in liver-injured rats was studied in vivo by measuring the clearance rate (K) of the drug from the blood, and its excretion in the urine. The K values in probenecid, diethyl maleate and carbon tetrachloride (CC14)-treated rats were much smaller than those in control rats. Probenecid, a known inhibitor of glutathione S-transferase, inhibited the urine excretion of azathioprine, and diethyl maleate produced a prompt depletion of hepatic reduced glutathione (GSH). Reduced levels of both GSH and glutathione S-transferase activity were observed in rats treated with CC14. Pretreatment with GSH, producing a slight and temporal increase of GSH in liver, resulted in no significant change of the K value. These findings, together with the reported kinetic data of the transferase, indicate that the conversion of azathioprine to 6-mercaptopurine (6-MP) in vivo may be catalyzed largely enzymatically by glutathione S-transferase in the liver.

Animals↗
PubMed1980

Gas chromatographic determination of nitrite in foods as trimethylsilyl derivative of 1H-benzotriazole.

1,2-Diaminobenzene reacts with nitrite in acidic solution to form 1H-benzotriazole, which can be extracted into ethyl acetate. After evaporation of the ethyl acetate, 1H-benzotriazole is determined as its trimethylsilyl derivative by gas--liquid chromatography on a column of 15% SE-30 on chromosorb G HP at 200 degrees C with flame-ionization detection. The nitrite concentration is calculated from the peak height. Amounts of 0.5--10 microgram of nitrite-nitrogen can be determined. For the determintion of nitrite in foods, clean-up of the crude extracts by ion-exchange column chromatography allows the satisfactory elimination of interferents and permits concentrations down to 0.41 ppm to be determined. The recovery of the nitrite added to foods at the 4.1 ppm level ranges from 94.6 to 98.7% and at the 8.2 ppm level it ranges from 95.2 to 98.8%. The trimethylsilyl derivative of 1H-benzotriazole was identified as 1-trimethylsilylbenzotriazole by combined gas chromatographic--mass spectrometric examination and nuclear magnetic resonance spectrometry.

Food Analysis↗
PubMed1980

Nutritional management of patients with severe liver disease by using intravenous hyperalimentation and elemental diet.

Management of protein-calorie malnutrition found in 32 patients with severe liver diseases such as fulminant hepatitis and cirrhosis of the liver was carried out using 2 types of synthetic amino acid solution (Hep-OU and Fischer solution) for intravenous and enteral alimentations with rapid monitoring of serum aminogram. Intravenous hyperalimentation of these cases resulted in maintenance of nutritional status with improvement of nitrogen balance and normalization of impaired serum aminogram. During this study, however, nutritional support was initiated only when intractable ascites, upper gastrointestinal bleeding and hepatic encephalopathy were observed. In 2 cases of fulminant hepatitis with sepsis and 3 hepatoma patients with ascites, elemental diet containing maltose and amino acids was used to supply sufficient amounts of nutrients in a minimum volume of water. These techniques with simultaneous monitoring of urinary excretion of 3-methylhistidine and creatinine height index as nutritional parameters make nutritional management easy for patients with liver disease.

Amino Acids↗
PubMed1980

Plasma cyclic AMP level in psychiatric diseases of childhood.

Determinations were made of the plasma cyclic AM level to examine its relationship with hyperkinesis (Werry-Weiss-Peters Activity Scale, WWPAS) and other features of mental disorders in 80 children, of whom 21 had early infantile autism, 15 hyperkinetic mental retardation, 12 minimal brain dysfunction and 32 Down's syndrome. In autistic and hyperkinetic mentally retarded children, the plasma cyclic AMP levels were higher than in normal children and were positively correlated with the WWPAS score. In children with minimal brain dysfunction, the plasma cyclic AMP level was significantly lower than in normal children and was not correlated with the WWPAS score. In children with Down's syndrome, the plasma cyclic AMP level was somewhat higher than in normal children.

Adult↗
PubMed1980

Altered pharmacodynamics of 1-(2-tetrahydrofuryl)-5-fluorouracil by pretreatment of rats with phenobarbital, indomethacin, diclofenac sodium and carbon tetrachloride.

The disappearance curves of 1-(2-tetrahydrofuryl)-5-fluorouracil (FT-207) from the circulating blood were divided into three different phases, K1, K2 and K3 after its intravenous administration to rats. The relationship between the activity of liver microsomal drug-metabolizing enzymes and K3 values, which were obtained by measuring FT-207 levels between 5 and 24 h after the injection, was observed with phenobarbital, indomethacin, diclofenac sodium and carbon tetrachloride-pretreated rats. Therefore, the blood disappearance rate of K3 was suggested to be an effective parameter for estimating FT-207 metabolism in the liver.

Animals↗