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Biomedical subjects

J N Green

Publications and source records attributed to J N Green.

5 recordsLinked to original sources

The metabolism of isamoxole in the rat and guinea-pig.

1. The absorption, metabolism and excretion of isamoxole, (2-methyl-N-butyl-N-(4-methyloxazol-2-yl)propanamide), a compound with anti-allergy properties, has been studied in the rat and guinea-pig. 2. The compound was well-absorbed by both species after oral doses of 50 to 150 mg/kg. It underwent extensive first-pass metabolism in the liver, and was excreted as a mixture of metabolites, predominantly in the urine, within 48 h. 3. Three major routes of metabolism were involved, namely deacylation, oxidative ring scission and alkyl oxidation. 4. A major plasma and urine metabolite was 1-butyl-3-(1-carboxyethyl)urea, and this was accompanied by low levels of its cyclized product 3-butyl-5-methylhydantoin.

Animals

The value of amniocentesis in prolonged pregnancy.

A total of 2702 transabdominal amniocenteses performed at the Los Angeles County--University of Southern California Medical Center were reviewed, with particular emphasis on 392 samples performed beyong 41 weeks' gestation. A significant rise in the percent of amniocenteses with meconium staining was found to occur at an beyond 39 weeks. Meconium-stained fluid at amniocentesis was found to be associated with an increased incidence of babies weighing greater than 4000 g, maternal diabetes mellitus, and cesarean deliveries, in comparison to samples with clear amniotic fluid. Infants with meconium-stained fluid had an increased incidence of low 1-minute Apgar scores, but all 5-minute Apgar scores were 7 or greater. Ten perinatal deaths occurred after an amniocentesis with clear fluid in prolonged pregnancy, with four of these occurring within 7 days of amniocentesis. Lecithin/sphingomyelin (L/S) ratios less than 2.0 were found in 6% of amniocenteses performed beyond 41 weeks. However, none of the newborns with low L/S ratios develop subsequent neonatal respiratory distress syndrome. Amniotic fluid creatine values or blood-contaminated fluid were not found to be correlated with fetal outcome. No fetal mortality was attributable to amniocentesis. In view of the significant amount of false-positive and false-negative results, and the rare inherent danger associated with amniocentesis, its use solely to demonstrate the presence or absence of meconium staining appears to be of questionable value in the management of prolonged pregnancy.

Amniocentesis

Disposition and metabolism of benoxaprofen in laboratory animals and man.

1. The absorption, distribution, metabolism and excretion of benoxaprofen, a novel anti-inflammatory compound, has been studied in the dog, mouse, rat, rabbit, rhesus monkey and man. 2. Benoxaprofen was well absorbed after oral administration of doses of 1 to 10 mg/kg in all six species. Only unchanged drug was detected in plasma. It was extensively bound to plasma proteins, the highest binding occurring in man (99.8%) and rhesus monkey (99.6%). 3. Species differences were observed in the plasma elimination half-life, the longest being in man (33 h). The rat and mouse also had high values (28 and 24 h respectively) whereas in the other species, values were less than 13 h. 4. After an oral dose of [14C]benoxaprofen (20 mg/kg) to female rats, tissue concn. was highest in liver, kidney, lungs, adrenals and ovaries. Tissue distribution in the pregnant rat was identical to the normal female. The compound was found in the foetus but at a concn. lower than in all maternal organs. 5. There was a marked species difference in the route of excretion. In man, rhesus monkey and rabbit, excretion in the urine was a major route, whilst biliary--faecal excretion was the only effective route in the rat and dog. 6. No major metabolic transformation of benoxaprofen was observed. Man and dog excreted the compound predominantly as the ester glucuronide whereas the rat, mouse, rabbit and rhesus monkey excreted a large proportion of the dose unchanged.

Administration, Oral