Sexual behaviour and desire to discuss mental health as reported by HIV-infected men who have sex with men.

We assessed sexually transmitted infection risk behaviours and desire to discuss mental health, as reported by 426 HIV-infected men who have sex with men receiving HIV care in eight urban clinics. Most of these patients (90%) had begun HIV care >1 year ago. In the past year, 74% had multiple sexual partners, 75% engaged in anal intercourse, 48% had >1 HIV-uninfected partner and 82% used illegal psychoactive drugs. Among those reporting anal intercourse, approximately 61% reported using a condom during the most recent episode. Among all patients, 70% wanted to talk with their clinicians about how they felt mentally or emotionally. Using a two-tailed chi-squared test, we found that patients who engaged in unprotected receptive anal sex were more likely to want such a conversation than those who did not (80% versus 62%, P < 0.01); and those who engaged in unprotected insertive anal sex were also more likely to want such a conversation (81% versus 63%, P < 0.01). The findings highlight the prevalence of risky sexual behaviour and of mental health concerns in the participating patient population. Patients reporting risky sexual behaviour were more likely to want to discuss how they felt mentally or emotionally than those not reporting such behaviour.

Vasoconstrictor action of angiotensin I-convertase and the synthetic substrate (Pro11,D-Ala12)-angiotensin I.

A chymase (also referred to as angiotensin I-convertase) specific for the conversion of angiotensin (Ang) I to Ang II has been identified in human heart. This serine protease is also present in dog and marmoset vasculature. We examined the vasoconstrictor effects of Ang II putatively generated from an angiotensin-converting enzyme (ACE)-resistant convertase synthetic substrate (SUB) in vivo and in vitro. In marmosets, SUB (7 to 700 micrograms/kg i.v.) or Ang I (0.1 to 30 micrograms/kg) caused similar dose-dependent increases in mean arterial pressure (10 to 100 mm Hg) and decreases in heart rate. Pressor effects of SUB were slightly attenuated at low (but not high) doses by captopril (CAP, 1 mg/kg i.v.) and blocked by losartan (5 mg/kg i.v.); in contrast Ang I pressor effects were substantially blocked by both. In isolated canine superior mesenteric artery, Ang I-induced contraction was eliminated by losartan and reduced but not eliminated by 10 mumol/L CAP. When combined with the serine protease inhibitor chymostatin, CAP eliminated Ang I-induced contraction, but chymostatin alone had no effect. SUB-induced contraction was not blocked by CAP but was equally blocked by chymostatin (25 mumol/L) alone or by the combination of CAP (10 mumol/L) and chymostatin (25 mumol/L); losartan (10 mumol/L) eliminated SUB-induced responses. Previous studies have suggested that Ang I-convertase is important for production of Ang II in the heart. Our results are consistent with a potential role for Ang I-convertase in the production of Ang II in the vasculature, resulting in Ang II-mediated vasoconstriction.

Effects of doxazosin and other antihypertensives on serum lipid levels and lipoprotein lipase in the C57BR/cdJ mouse.

Doxazosin has been shown to lower serum cholesterol levels in the cholesterol-fed (0.75% in a synthetic diet that contains sucrose and cholic acid) C57BR/cdJ mouse. These studies show that the drug's main effect is to lower low-density lipoprotein (LDL) cholesterol and leave high-density lipoprotein (HDL) cholesterol levels unchanged. The drug had cholesterol-lowering effects in this model at doses down to 3 mg/kg. In order to determine if these effects are unique to selective alpha 1-inhibitors, other antihypertensives including hydralazine, papaverine, and captopril were investigated. None of the drugs has any effects on the plasma lipid metabolite levels. The effects of propranolol and polythiazide on plasma lipid levels were also examined in these mice. Propranolol had no effect, whereas the diuretic increased plasma cholesterol levels. Both propranolol and polythiazide increased plasma triglycerides. Doxazosin has been shown to inhibit cGMP phosphodiesterase in the laboratory. The effects of zaprinast, a cGMP phosphodiesterase inhibitor, were tested in order to determine if this property of the drug could be responsible for its lipid-lowering activity. The data show that there are no effects on plasma lipids in zaprinast-treated animals. Doxazosin treatment increased heparin-releasable lipoprotein lipase in fasted chow-fed mice. The drug was without effect on the activity of hepatic lipase present in the plasma after heparin release. No effects were observed on the tissue levels of either hepatic or lipoprotein lipases (heart or adipose tissue).

Benoxaprofen photosensitization of cell membrane disruption.

Benoxaprofen (BXP) is a nonsteroidal anti-inflammatory drug which causes cutaneous phototoxicity. Because the in vivo phototoxicity may involve photosensitized damage to mast cell membranes, the mechanism for photosensitized damage was studied in a single model system, the red blood cell. Oxygen-dependent and oxygen-independent mechanisms for membrane disruption were detected. Oxygen-dependent lysis was not quenched by superoxide dismutase and was quenched only at high sodium azide concentrations. A two-step mechanism is proposed involving initial photodecarboxylation of BXP to form a lipophilic photoproduct which subsequently photosensitizes membrane damage. Human serum albumin at 0.03% totally inhibited BXP-photosensitized lysis.