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Biomedical subjects

B Crowe

Publications and source records attributed to B Crowe.

8 recordsLinked to original sources

The effects of ropivacaine hydrochloride on platelet function: an assessment using the platelet function analyser (PFA-100).

Amide local anaesthetics impair blood clotting in a concentration-dependent manner by inhibition of platelet function and enhanced fibrinolysis. We hypothesised that the presence of ropivacaine in the epidural space could decrease the efficacy of an epidural blood patch, as this technique requires that the injected blood can clot in order to be effective. Ropivacaine is an aminoamide local anaesthetic used increasingly for epidural analgesia during labour. The concentration of local anaesthetic in blood achieved in the epidural space during the performance of an epidural blood patch is likely to be the greatest which occurs (intentionally) in any clinical setting. This study was undertaken to investigate whether concentrations of ropivacaine in blood, which could occur: (i) clinically in the epidural space and (ii) in plasma during an epidural infusion of ropivacaine, alter platelet function. A platelet function analyser (Dade PFA-100, Miami) was employed to assess the effects of ropivacaine-treated blood on platelet function. The greater concentrations of ropivacaine studied (3.75 and 1.88 mg x ml(-1)), which correspond to those which could occur in the epidural space, produced significant inhibition of platelet aggregation. We conclude that the presence of ropivacaine in the epidural space may decrease the efficacy of an early or prophylactic epidural blood patch.

Adult↗

Improvement of the immune response against plasmid DNA encoding OspC of Borrelia by an ER-targeting leader sequence.

The present study outlines the characterization of a DNA-based immune response against the OspC antigen, one of the most promising candidates for a Borrelia vaccine. Balb/c mice were injected intradermally with plasmid DNA encoding the OspC gene (lacking the natural leader sequence) under transcriptional control of the cytomegalovirus (CMV) promotor. Immunization with this construct elicited only a marginal response, which was drastically improved by a fusion construct containing the human tissue plasminogen activator (hTPA) signal sequence. The results indicate that for DNA-based immunization against OspC an ER-targeting signal may be necessary for both antibody production as well as cellular immune responses.

Amino Acid Sequence↗

Return to work following coronary artery bypass surgery or percutaneous transluminal coronary angioplasty.

Return to work (RTW) and other treatment outcomes of coronary artery bypass graft (CABG) and percutaneous transluminal coronary angioplasty (PTCA) patients were compared. Consecutive patients at one centre (n = 112 CABG and 119 PTCA patients) were interviewed 6-18 months following treatment (groups were similar in sex and social class). Pre-treatment employment levels were similar (41 and 38% for CABG and PTCA groups, respectively). PTCA patients were more likely to smoke, have angina, have less advanced cardiovascular disease and have been advised to stop working for medical reasons pre-treatment. Post-treatment levels of employment increased significantly. RTW rates were similar for CABG and PTCA groups (59 and 68% respectively). Both groups had reduced smoking to similar levels. The PTCA group continued to have higher levels of angina. For those without angina, PTCA patients were significantly more likely to return to work (73 vs 55%, P < 0.01). Both CABG and PTCA resulted in increased employment post-treatment.

Angina Pectoris↗

A comparison of the variable antigens expressed by clone IV-1 and subgroup III of Neisseria meningitidis serogroup A.

Serogroup A Neisseria meningitidis of subgroup III has caused two pandemics of meningococcal meningitis since 1966 and recently spread to East Africa. The last epidemics in West Africa in the early 1980s were caused by clone IV-1. Surface antigens of clone IV-1 strains from West Africa and subgroup III strains from both pandemic waves were analyzed. Lipopolysaccharide was stable within clone IV-1 but variable in subgroup III. Pili from clone IV-1 possessed class I epitopes, while those from subgroup III also possessed class IIa epitopes. Certain class 5 protein variants were expressed by both bacterial clones, possibly reflecting either inheritance of primeval genes or horizontal transmission. Exposure of Gambians to clone IV-1 bacteria stimulated production of bactericidal antibodies cross-reactive with subgroup III bacteria in some individuals but of type-specific antibodies in others. Gambians without bactericidal antibodies usually became healthy carriers rather than developing meningococcal disease on exposure to virulent meningococci.

Africa, Western↗

Preliminary trial of the effect of general practice based nutritional advice.

Despite formal recommendations for dietary change to reduce the incidence of ischaemic heart disease, the acceptability and effectiveness of the proposed diets have not been well investigated in population based studies. In this preliminary investigation of nutritional advice in a well population, subjects in one group practice were randomized to receive either dietary instruction or simple follow up without instruction. The dietary recommendations were well received, and a substantial proportion of subjects reported altering their diets in accordance with them. There were modest beneficial changes in plasma lipid levels among men. Thus, using general practice as an avenue for promoting dietary change is feasible, and may be effective among men.

Adult↗