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Biomedical subjects

A Tait

Publications and source records attributed to A Tait.

160 records · Page 9Linked to original sources
PubMedDate not supplied

Self-fertilisation in Trypanosoma brucei.

We have investigated whether Trypanosoma brucei can undergo self-fertilisation. A group of 27 metacyclic clones derived from the tsetse transmission of a mixture of two genetically marked stocks was analysed and 22 clones were observed to be of non-hybrid phenotype. A group of 10 clones from this non-hybrid subset were then analysed for one isoenzyme, one restriction fragment length polymorphism and three karyotype markers potentially informative for the detection of self-fertilisation. Five of the 10 clones were found to be recombinant for at least one marker and we interpret these recombination events as indicating the clones to be products of self-fertilisation. We have also analysed a limited number of metacyclic clones from stocks of T. brucei each singly transmitted through tsetse flies but, so far, no evidence of recombination has been detected. We conclude that T. brucei is able to self-fertilise but there may be a requirement for the presence of dissimilar stocks to initiate such an event.

Animals↗
PubMedDate not supplied

Hybrid formation between African trypanosomes during cyclical transmission.

Trypanosomes of the species Trypanosoma brucei reproduce primarily by binary fission, but the frequency of enzyme electrophoretic variants in natural populations of T. brucei has provided indirect evidence for the existence of a sexual cycle. These studies, coupled with studies of restriction fragment length polymorphisms of genes encoding glycolytic enzymes, have also provided evidence for T. brucei being diploid. Here we report direct evidence of gene exchange between two different clones of trypanosomes after mixed infection and full cyclical development in the tsetse fly vector.

Animals↗
PubMedDate not supplied

Reactivity toward cysteine of antimicrobial carbamimidothioic acid phenylalkylesters salts.

The rates of reaction toward cysteine of a series of carbamimidothioic acid phenylmethylesters halides were investigated in phosphate buffer pH 7.4 at 37 degrees C under pseudo-first-order conditions. The reaction involves nucleophilic attack of cysteine on the C-S bond of isothiouronium mojety and corresponding benzenemethanethiols were detected as product of the reaction. Apparent first-order rate constants were determined.

Anti-Infective Agents↗
PubMedDate not supplied

Metabolism of diazepam in vitro by human liver. Independent variability of N-demethylation and C3-hydroxylation.

The interindividual variability of diazepam metabolism was studied using human livers. The formation of N-desmethyldiazepam (NDZ) and 3-hydroxydiazepam (temazepam, TMZ), was monitored by gas chromatography. In 10 livers, Km values for NDZ and TMZ formation varied independently from each other, each by a factor of 4, from 100 to 400 microM. This variability is consistent with the presence of at least two different cytochrome P-450 species controlling formation of these metabolites. In the same livers, Vmax for NDZ and TMZ production varied 6-fold and 15-fold, respectively.

Anti-Anxiety Agents↗