In order to investigate the contribution of histamine to bronchoconstriction provoked by inhaled allergen and adenosine monophosphate (AMP), we have observed the effects of prior treatment with the potent H1-receptor antagonists, terfenadine and astemizole. Nine mild, atopic asthmatics underwent inhalation challenge tests on 6 separate days with histamine, allergen extract, and AMP using single concentrations previously shown to produce a 30% fall in FEV1. For each agonist, bronchoprovocation was performed 3 h after treatment with either terfenadine 180 mg or matched placebo, and airway caliber assessed by measurement of FEV1 over a period of 45 min. AMP challenge was also performed after prior treatment with astemizole. After placebo, histamine produced rapid bronchoconstriction, reaching a maximum within 5 min and returning to within 10% of baseline at 25 min. Pretreatment with terfenadine abolished the bronchoconstrictor response to histamine completely. In contrast, bronchoconstriction provoked by allergen after placebo was slower in onset and sustained during the 45 min of observation. Terfenadine only partially inhibited this response to allergen by 50 +/- 10% (mean +/- SEM) with the maximal effect being observed within the first 5 to 8 min of challenge. AMP inhalation provoked rapid bronchoconstriction similar in time course to that of histamine, and this reaction was inhibited by 86 +/- 8.1% by terfenadine. Astemizole produced inhibition of the response to AMP that was almost identical to that of terfenadine. On the basis of in vitro studies, we interpret these differential effects of terfenadine as reflecting the contribution of histamine to the various airway challenges.(ABSTRACT TRUNCATED AT 250 WORDS)

The problems associated with pulmonary aspergilloma were assessed retrospectively in 23 patients presenting from 1953 to 1982. Haemoptysis occurred in over half the patients and in two it was fatal. Invasive aspergillosis occurred in five patients, a higher proportion than in earlier reports, and two of these died. Amphotericin B in combination with either flucytosine or natamycin and, more recently, ketoconazole have proved useful in the treatment of this condition.

In this study we investigated the effect of the selective and potent thromboxane A2 (TxA2) receptor antagonist GR32191 on smooth muscle contraction induced by the TxA2 analogue U46619, prostaglandin (PG) D2, PGF2 alpha, and methacholine (MCh) in guinea pig airways in vitro and the airways response provoked by inhaled PGD2 and MCh in asthmatic subjects in vivo. GR32191 antagonized competitively the contractile responses of all three prostanoids to a similar degree but had no effect on MCh-induced contractions. In asthmatic subjects GR32191, in a single oral dose of 80 mg, did not affect base-line airway caliber or MCh-induced broncho-constriction but caused significant inhibition of PGD2-induced bronchoconstriction, displacing the concentration-response curves to the right by greater than 10-fold. The effect of the same oral dose of GR32191 on allergen-induced immediate bronchoconstriction was subsequently investigated in allergic asthmatic subjects. In individual subjects, GR32191 inhibited to varying degrees the overall bronchoconstrictor response, with the maximum effect occurring between 10 and 30 min after allergen challenge. These studies suggest that prostanoids contribute to the immediate bronchoconstriction induced by inhaled allergen in allergic asthmatics, and that this effect is mediated by stimulation of a thromboxane receptor.

We present the updated British Association for Sexual Health and HIV guidelines for HIV post-exposure prophylaxis following sexual exposure (PEPSE). This document includes a review of the current data to support the use of PEPSE, considers how to calculate the risks of infection after a potential exposure, and provides recommendations on when PEPSE should and should not be considered. We also review which medications to use for PEPSE, provide a checklist for initial assessment, and make recommendations for monitoring individuals receiving PEPSE. Special scenarios, cost-effectiveness of PEPSE, and issues relating to service provision are also discussed. Throughout the document, the place of PEPSE within the broader context of other HIV prevention strategies is considered.

The effect of flurbiprofen, a potent cyclo-oxygenase inhibitor, on histamine and methacholine reactivity was assessed in seven atopic subjects with asthma. Flurbiprofen 150 mg daily for three days displaced the histamine-FEV, concentration-response curve to the right by 1.5 doubling doses, whereas no effect was observed on the response to methacholine. Subsequently the effects of flurbiprofen and terfenadine, a specific H, histamine receptor antagonist, on allergen induced bronchoconstriction were studied in seven atopic but non-asthmatic subjects. The subjects inhaled the concentration of grass pollen allergen that had previously been shown to produce a 20% fall in FEV, on separate occasions after prior treatment with placebo, flurbiprofen 150 mg daily for three days, terfenadine 180 mg three hours before challenge, and the combination of flurbiprofen and terfenadine. After placebo, allergen challenge caused a mean (SEM) maximum fall in FEV, of 37-6% (2 6%) after 20 (3 7) minutes, followed by a gradual recovery to within 1 5 % of baseline at 60 minutes. Terfenadine reduced the maximum allergen provoked fall in FEV, to 21-5% (2-2%) and reduced the area under the time-response curve (AUC) by 50% (6%). Flurbiprofen alone reduced the mean maximum fall in FEV, to 29-6% (3-2%) and reduced the AUC by 26%. The effect of the combination of flurbiprofen and terfenadine did not differ significantly from that of terfenadine alone. We conclude that histamine and prostaglandins contribute to immediate allergen induced bronchoconstriction and that a complex interaction occurs between the two classes of mediators.