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Biomedical subjects

I J Bruce

Publications and source records attributed to I J Bruce.

27 records · Page 2Linked to original sources
PubMed1989

The effects of vanadate on the yeast Saccharomyces cerevisiae.

Growth of Saccharomyces cerevisiae on non-fermentable medium was more sensitive to inhibition by vanadate than growth on fermentable medium. The frequency of petite mutants increased in cultures grown for 18 hours in fermentable medium containing vanadate. However, oxygen uptake markedly increased in yeast cultures grown in the presence of vanadate, a similar effect being produced by phosphate. It was also found that oligomycin toxicity was relieved by vanadate. These results suggest that vanadate may interact with the mitochondria of S. cerevisiae.

Culture Media↗
PubMed1987

The effect of chloramphenicol and cycloheximide on platelet aggregation and protein synthesis.

This study investigated the role of platelet protein synthesis in platelet aggregation. Cycloheximide (Cx) and chloramphenicol (Cm) were used as inhibitors of cytoplasmic (80S ribosome directed) and mitochondrial protein synthesis respectively. The effect of these agents on human platelet aggregation and L-[U-14C]leucine incorporation into platelet protein was investigated. Cm exhibited dose-dependent inhibition of collagen, thrombin and secondary ADP aggregatory responses, but had no effect on arachidonate or primary ADP responses over a similar concentration range (3.1 X 10(-3), 3.1 X 10(-4) and 3.1 X 10(-5) M). Cm also inhibited platelet secretion associated with collagen and secondary ADP responses. Furthermore, Cm exhibited a similar dose-dependent inhibition of L-[U-14C]leucine incorporation into platelet protein reaching 80% inhibition of incorporation at 3 X 10(-3) M. At similar concentrations (3.5 X 10(-3), 3.5 X 10(-4) and 3.5 X 10(-5) M) Cx failed to show inhibition of human platelet aggregation by all agonists used with the exception of collagen where some inhibition was seen at high Cx concentration (3.5 X 10(-3) M). Cx was also found to be ineffective at inhibiting L-[U-14C]leucine incorporation into platelet protein at all concentrations tested. These results suggest that the majority of platelet protein synthesis is mitochondrial and that this protein synthesis may have a role in human platelet aggregation.

Blood Platelets↗
PubMed1984

Effect of aspirin on mitochondrial mutagens in Saccharomyces cerevisiae.

The mitochondrial mutation petite was induced in yeast cells by ethidium bromide (EB), Adriamycin (ADR) and 4-nitroquinoline-N-oxide (NQO). In the presence of aspirin in concentrations ranging from 0.1 to 1.0 mg/ml, the mutagenicity of EB and ADR was reversed but petite induction by NQO was unaffected. At these concentrations, aspirin also reversed mitochondrial inhibition by oligomycin, a non-mutagenic inhibitor of the organellar ATPase complex. Cells grown in the presence of aspirin alone showed a significantly higher rate of oxygen uptake than untreated control cultures when the drug concentration ranged from 0.05 to 1.0 mg/ml. At concentrations of 2 mg/ml and above, aspirin inhibited mitochondrial respiration.

Aspirin↗
PubMedDate not supplied

Vanadate inhibition of mitochondrial respiration and H+ ATPase activity in Saccharomyces cerevisiae.

The effects of vanadate on mitochondrial respiration and H+ ATPase activity in Saccharomyces cerevisiae were studied. A 50% inhibition of oxygen uptake in isolated mitochondria was produced by 4.4 mM-V2O5. Activity of H+ ATPase in whole mitochondria was inhibited by 50% by 5.5 microM-V2O5, in submitochondrial particles by 55 microM-V2O5; and in the chloroform-released H+ ATPase by 0.5 mM-V2O5. Vanadate was also found to relieve growth inhibition caused by the mitochondrial H+ ATPase inhibitors NN'-decyclohexylcarbodiimide and oligomycin. These results imply that vanadate could affect mitochondrial respiration by interacting with the H+ ATPase in S. cerevisiae.

Adenosine Triphosphatases↗
PubMedDate not supplied

Improved manufacture and application of an agarose magnetizable solid-phase support.

A simple, semiautomated, nonhazardous procedure for the production of a magnetizable solid-phase support (MSPS) has been developed based on the extrusion of molten agarose-iron oxide mixtures, which enables manufacture of a range of differently sized spherical agarose-iron oxide beads. This system has enabled scale-up of an original manufacture procedure and reproducible preparation of kg quantities of MSPS suitable for biomolecular purifications. An improved protocol for the isolation of plasmid DNA directly from cell lysates using this MSPS, derivatized with diethylaminoethyl (DEAE) groups, is reported. This involves a modified alkaline lysis, followed by adsorption to and elution from the support, yielding plasmid DNA of a purity comparable with, or better than, other methods of plasmid isolation. Using the same procedure, plasmid DNA can be isolated from bacterial cell culture volumes of 1.5 mL and 100 mL with equal efficiency and purity.

Chromatography, Gel↗
PubMedDate not supplied

Nucleic acid amplification mediated microbial identification.

Nucleic acid amplification techniques have and are revolutionising the way research, academia, medicine, environmental and quality control issues are dealt with. In particular, the polymerase chain reaction, (PCR), originally mentioned in 1985 has greatly modified the ways in which scientists and clinicians go about nucleic acid sequence analysis and manipulation and has great implications for molecular biology in general and diagnostics in particular. This report attempts to review the use of PCR and isothermal nucleic acid amplification techniques in the rapid identification of microorganisms. Key methodologies have been noted, their strengths and weaknesses commented upon and comparisons have been drawn between isothermal and thermally cycled nucleic amplification techniques in rapid microbial identification.

Bacteria↗