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Abnormal depletion or accumulation of islet lipid may be important for the development of pancreatic cell failure. Long-term lipid sensing by cells may be co-ordinated via peroxisome proliferator-activated receptors (PPARs). We investigated whether PPAR activation in vivo for 24 h affects basal and glucose-stimulated insulin secretion in vivo after intravenous glucose administration and ex vivo in isolated perifused islets. Insulin secretion after intravenous glucose challenge was greatly increased by high-fat feeding (4 weeks) but glucose tolerance was minimally perturbed, demonstrating insulin hypersecretion compensated for insulin resistance. The effect of high-fat feeding to enhance glucose-stimulated insulin secretion was retained in perifused islets demonstrating a stable, long-term effect of high-fat feeding to potentiate islet glucose stimulussecretion coupling. Treatment of high-fat-fed rats with WY14,643 for 24 h reversed insulin hypersecretion in vivo without impairing glucose tolerance, suggesting improved insulin action, and ex vivo in perfused islets. PPAR activation only affected hypersecretion of insulin since glucose-stimulated insulin secretion was unaffected by WY14,643 treatment in vivo in control rats or in perifused islets from control rats. Our data demonstrate that activation of PPAR for 24 h can oppose insulin hypersecretion elicited by high-fat feeding via stable long-term effects exerted on islet function. PPAR could, therefore, participate in ameliorating abnormal glucose homeostasis and hyperinsulinaemia in dietary insulin resistance via modulation of islet function, extending the established requirement for PPAR for normal islet lipid homeostasis.

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The objective was to determine how often gonococcal (GC) infection is accompanied by chlamydial co-infection and to determine risk factors for dual infection. All GC-positive cultures were identified between 24 April and 9 September 1998, among patients seen at the three genitourinary medicine (GUM) clinics across the Chelsea and Westminster Directorate. Chlamydia trachomatis was diagnosed using an enzyme-linked immunosorbent assay (ELISA) (Dade-Behring). One hundred and fifty-three episodes of gonorrhoea were identified. Information on chlamydial infection was available for 149 cases of GC of whom 16 (10.7%) were found to be co-infected with C. trachomatis. In univariate analysis, chlamydial co-infection was exclusively diagnosed in heterosexuals, and was more likely to be diagnosed among females, in younger individuals and in individuals of black Caribbean ethnic group. In multivariable analyses, however, only the sex and age of the individual were independently associated with chlamydial co-infection. The rate of co-infection was 10.7%. Independent risk factors were being less than 20 years old and being female.

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