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Biomedical subjects

S Slater

Publications and source records attributed to S Slater.

64 records · Page 4Linked to original sources
PubMed1977

Reduction in plasma norepinephrine during fenfluramine treatment.

Plasma norepinephrine levels were reduced to 30% of placebo levels during the administration of fenfluramine, 120 mg/day, for 10 or more days. There was also a significant reduction in plasma dopamine beta-hydroxylase activity during fenfluramine treatment, suggesting that chronic administration may induce antiadrenergic effects which may be useful in the treatment of disorders affected by circulating catecholamines.

Adult↗
PubMedDate not supplied

PHA production, from bacteria to plants.

The genes encoding the polyhydroxyalkanoate (PHA) biosynthetic pathway in Ralstonia eutropha (3-ketothiolase, phaA or bktB; acetoacetyl-CoA reductase, phaB; and PHA synthase, phaC) were engineered for plant plastid targeting and expressed using leaf (e35S) or seed-specific (7s or lesquerella hydroxylase) promoters in Arabidopsis and Brassica. PHA yields in homozygous transformants were 12-13% of the dry mass in homozygous Arabidopsis plants and approximately 7% of the seed weight in seeds from heterozygous canola plants. When a threonine deaminase was expressed in addition to bktB, phaB and phaC, a copolyester of 3-hydroxybutyrate and 3-hydroxyvalerate was produced in both Arabidopsis and Brassica.

Acetyl-CoA C-Acyltransferase↗
PubMedDate not supplied

The in vitro effects of selected environmental toxicants on two heme synthesis enzymes.

Benzene and some of its substitution products become environmental toxicants due to improper disposal procedures. Benzene has been found to alter heme and globin synthesis in anucleate rabbit reticulocytes (Forte et al., 1976; Wildman et al., 1976) and based on these findings we felt it would be useful to determine what, if any, effect these derivatives would have on heme synthesis in vitro by studying their influence on delta-aminolevulinic acid synthetase (ALAS) and ferrochelatase (FC) activities in rat liver homogenates. ALAS was measured according to Ebert et al. (1970). FC was measured after Williams et al. (1980). Final concentrations of each added compound to the reaction mixture were 10(-3) to 10(-6) M. Normal values for rat liver ALAS were 250-350 nmol ALA/g protein/30 min, mean 290 +/- 40, and for FC were 12-40 mumol heme/g protein/45 min, mean 20 +/- 7. At 10(-3) M and lower concentrations these compounds inhibited ALAS and stimulated FC activities. Their effect on ALAS activity expressed as percentage of control of three analyses performed in triplicate +/- SEM was: o- and p-dinitrobenzenes-46 +/- 2; trinitrotoluenes-55 +/- 2; dinitrotoluenes-70 +/- 2; and amino-dinitrotoluenes-171 +/- 4. The stimulatory effect of these compounds expressed as percentage of control +/- SEM on FC was: dinitrotoluenes-171 +/- 3; dinitrobenzenes-152 +/- 3; trinitrotoluenes-142 +/- 4; and amino-dinitrotoluenes-130 +/- 4. Other classes of compounds tested did not significantly affect these enzymes at the same concentrations. These in vitro techniques may prove useful for predicting in vivo toxicologic effects of pollutants on species of interest.

5-Aminolevulinate Synthetase↗