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Biomedical subjects

S J Barton

Publications and source records attributed to S J Barton.

7 recordsLinked to original sources

Reproductive toxicity studies of ademetionine.

S-Adenosyl-L-methionine sulphate-p-toluene sulphonate (ademetionine, SAMe), a donor of methyl groups, was examined for effects upon embryofoetal toxicity following both premating treatment and treatment during pregnancy and for peri- and post-natal toxicity in the rat at dosages of 0, 100, 200 and 400 mg/kg/d SAMe ion by subcutaneous or intravenous administration. Embryofoetal toxicity was also examined in the New Zealand White rabbit at dosages of 0, 10, 20 and 40 mg/kg/d SAMe by intravenous administration. Treatment was considered to be without adverse effect upon any of the reproductive parameters examined on either F0 or on the untreated F1 generations. There was no indication that treatment adversely affected the litter parameters including the incidences of malformations, anomalies and skeletal variants. Some slight changes in the activity of the F1 females derived from F0 animals given 400 mg/kg/d were considered to be of minimal importance. In contrast to the above, adverse effects upon the parents were noted at 400 mg/kg/d including local tissue reaction at the injection sites and retardation of body weight gain. In the intravenous studies some rigidity and dyspnoea were noted following administration. Following subcutaneous premating treatment there was also evidence of histopathological change to the kidney of the female rat. Increased water consumption was noted in this latter study and amongst females rearing offspring in the embryo foetal toxicity study in which the compound was administered intravenously. At the lower dosages administered to the rat some local tissue reaction was evident as was some retardation of body weight gain, minimal at the lowest intravenous dose.(ABSTRACT TRUNCATED AT 250 WORDS)

Abnormalities, Drug-Induced

Delineation of human prometaphase paracentromeric regions using sequential GTG- and C-banding.

The centromeric-paracentromeric regions of high-resolution human chromosomes have not been examined in detail. It is not clear which bands in the paracentromeric regions are included within the heterochromatin and are therefore not clinically meaningful, and which bands are excluded. This makes breakpoint analysis in these regions difficult. Using sequential G- and C-banding of high-resolution chromosome preparations from four clinically normal subjects and from one patient with a very small interstitial deletion of the chromosome 16 long arm, we have made a detailed analysis of the centromeric-paracentromeric regions of each chromosome and of the entire Y chromosome at the 400, 550, and 800-850 band stages. We present here the results of analysis of preparations at the 800-850 band stage.

Amino Acid Metabolism, Inborn Errors

Reproductive toxicity studies of rentiapril.

(2R,4R)-2-(o-Hydroxyphenyl)-3-(3-mercaptopropionyl)-4- thiazolidinecarboxylic acid (rentiapril, SA 446), an orally active inhibitor of angiotensin converting enzyme, was examined for effects upon general reproductive performance, for embryofoetal toxicity and for peri- and postnatal toxicity in the rat at dosages of 0, 20, 100 and 500 mg/kg/d. Embryofoetal toxicity was also examined in the New Zealand White rabbit at dosages of 0, 1, 2 and 4 mg/kg/d. The compound was administered by gastric intubation. Prolonged treatment at 100 and 500 mg/kg/d during the fertility study was associated with some slight depression of body weight gain of males. Body weight gain of females during gestation was significantly depressed at 500 mg/kg/d. There was salivation in both sexes at 500 mg/kg/d and also in males receiving 100 mg/kg/d. Following this prolonged treatment in the fertility study. Fo male and female kidney weights were increased at all dosages. Although there was no obvious effect upon fertility there was an increased incidence of total litter loss at 500 mg/kg/d and mean pup weights to day 21 post partum were reduced at this dosage and at 100 mg/kg/d with delays in the attainment of some of the developmental landmarks. In the rat treatment at 500 mg/kg/d from day 7 to 17 of pregnancy did not adversely effect embryofoetal development. Subsequent development and reproductive performance of the F1 offspring was also unimpaired. During this treatment period signs of salivation were seen at 500 mg/kg/d. Slight retardation of maternal body weight gain was noted at 500 mg/kg/d and at 100 mg/kg/d but not at 20 mg/kg/d.(ABSTRACT TRUNCATED AT 250 WORDS)

3-Mercaptopropionic Acid

Prenatal cocaine exposure: implications for practice, policy development, and needs for future research.

Terms such as coke babies and crack babies are appearing with increased frequency in the popular literature. Although the number of babies exposed to cocaine in utero has increased, synthesis of the literature to help determine the manifestations of cocaine exposure or to direct research on the problems experienced by cocaine-exposed infants and their care givers has yet to occur. In this analysis a synthesis of the literature related to the effects of perinatal cocaine exposure is provided. The manifestations, effects, and sequelae of cocaine exposure are explicated and a model is proposed to explain the mechanisms underlying physiologic and psychosocial expressions of exposure. Both time of exposure during gestation and dose relationships were identified as major predictor variables. Recommendations include the need for (1) an individualized intervention protocol and (2) prevention programs directed at pregnant women and women of childbearing age.

Cocaine