High prevalence of HIV infection among homeless and street-involved Aboriginal youth in a Canadian setting

Aboriginal people experience a disproportionate burden of HIV infection among the adult population in Canada; however, less is known regarding the prevalence and characteristics of HIV positivity among drug-using and street-involved Aboriginal youth. We examined HIV seroprevalence and risk factors among a cohort of 529 street-involved youth in Vancouver, Canada. At baseline, 15 (2.8%) were HIV positive, of whom 7 (46.7%) were Aboriginal. Aboriginal ethnicity was a significant correlate of HIV infection (odds ratio = 2.87, 95%CI: 1.02 – 8.09). Of the HIV positive participants, 2 (28.6%) Aboriginals and 6 (75.0%) non-Aboriginals reported injection drug use; furthermore, hepatitis C co-infection was significantly less common among Aboriginal participants (p = 0.041). These findings suggest that factors other than injection drug use may promote HIV transmission among street-involved Aboriginal youth, and provide further evidence that culturally appropriate and evidence-based interventions for HIV prevention among Aboriginal young people are urgently required.     

Evidence for endogenous formation of tobacco-specific nitrosamines in rats treated with tobacco alkaloids and sodium nitrite

Carcinogenic tobacco-specific nitrosamines are present in tobacco products and are believed to play a significant role in human cancers associated with tobacco use. Additional amounts of tobacco-specific nitrosamines could be formed endogenously. We tested this hypothesis by treating rats with nicotine and sodium nitrite and analyzing their urine. Initially, we treated groups of rats with (S)-nicotine (60 micromol/kg) and NaNO2 (180 micromol/kg), (S)-nicotine alone, NaNO2 alone or 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK, 12 nmol/kg) by gavage twice daily for 4 days. We collected urine and analyzed for two metabolites of NNK; 4-(methylnitrosamino)-1-(3- pyridyl)-1-butanol and its glucuronide. We did not detect these metabolites in the urine of rats treated with nicotine alone or nicotine plus NaNO2, indicating that endogenous conversion of nicotine to NNK did not occur. However, the urine did contain N'- nitrosonornicotine (NNN), N'-nitrosoanabasine (NAB) and N'- nitrosoanatabine (NAT). Analysis of the (S)-nicotine used in this experiment demonstrated that it contained trace amounts of nornicotine, anabasine and anatabine. In a second experiment, we used an identical protocol to compare the endogenous nitrosation of this (S)-nicotine with that of synthetic (R,S)-nicotine, which did not contain detectable amounts of nornicotine, anabasine or anatabine. NNN (0.53 x 10(-3)% of nicotine dose), NAB (0.68%) and NAT (2.1%) were detected in the urine of the rats treated with the (S)-nicotine and NaNO2. NNN (0.47 x 10(- 3)% of dose), but not NAB or NAT, was present in the urine of the rats treated with synthetic (R,S)-nicotine and NaNO2. NNN probably formed via nitrosation of metabolically formed nornicotine. These results demonstrate for the first time that endogenous formation of tobacco- specific nitrosamines occurs in rats treated with tobacco alkaloids and NaNO2. The potential significance of the results with respect to nitrosamine formation in people who use tobacco products or nicotine replacement therapy is discussed.      

Anerkennung als Belegarzt

Ohne Zusammenfassung     

Prekallikrein-Kallikrein conversion rate as a predictor of contrast material catastrophies

An in vitro is described that attempts to detect patients with a potential for adverse systemic reactions to contrast material. This test involves measuring the rate of conversion of prekallikrein to kallikrein under certain standard conditions. In a preliminary retrospective study, the test could be used to identify such patients with a sensitivity of 88%, a specificity of 82%, and a predictive value of 79%.     

Social inequalities and disability in older men: prospective findings from the British regional heart study

The independent association of socio-economic position with self-reported disability was assessed. The effect of home and car ownership as additional indices of socio-economic position within occupational social classes was explored. Data from a prospective study of a cohort of 7735 men aged 40-59 years at recruitment and representative of the occupational social class distribution of middle-aged men in Great Britain were used. Men were selected from one general practice in each of 24 towns in England, Wales and Scotland in 1978-1980. The present study concerns 5773 (88.4% of those able to take part) men aged 52-73 years at follow up in 1992 who completed the disability section of a postal questionnaire. A quarter (1453) of men reported disability. Socio-economic position measured as both occupational class (social class I vs. V: age-adjusted OR 5.0, 95% CI 3.4-7.5) and ownership of home and car (both vs. neither: age-adjusted OR 2.8, 95% CI 2.3-3.4) showed a graded relationship with likelihood of reporting disability in 1992. Within all social class groups, those owning both home and car had a lower risk of disability than those who owned neither, even after adjustment for a wide range of risk factors. Men from manual occupations were more likely than those in non-manual occupations to report disability on developing chronic diseases. The relationship between socio-economic position and severe, but not milder, disability appeared to be independent of disease status. Socio-economic position is a strong predictor of disability in later life independent of a wide range of lifestyle factors and presence of diagnosed disease. The likelihood of reporting disability between and within social class groups is influenced by material wealth.     

Pipe and cigar smoking and major cardiovascular events, cancer incidence and all-cause mortality in middle-aged British men

BACKGROUND: Pipe and cigar smoking are still regarded by many as less hazardous to health than cigarette smoking. METHODS: Prospective study of 7735 men aged 40-59 years drawn from general practices in 24 British towns with mean follow-up of 21.8 years. The outcome measures include major coronary heart disease (CHD) and stroke events, cancer incidence, and deaths from all causes. RESULTS: There were 1133 major CHD events and 440 stroke events, 919 new cancers and 1994 deaths from all causes in the 7121 men with no diagnosed CHD, stroke, diabetes, or cancer at screening. Compared with never smokers, pipe/cigar smokers (primary and secondary combined) showed significantly higher risk of major CHD events (relative risk [RR] = 1.69, 95% CI: 1.32, 2.14) and stroke events (RR = 1.62, 95% CI: 1.08, 2.41) and of cardiovascular, non-cardiovascular, and total mortality (RR = 1.49, 95% CI: 1.13, 1.96, RR = 1.40, 95% CI: 1.08, 1.83 and RR = 1.44, 95% CI: 1.19, 1.74, respectively), after adjustment for lifestyle and biological characteristics. They also showed a significantly higher incidence of smoking-related cancers (RR = 2.67, 95% CI: 1.70, 4.26), largely due to lung cancer (RR = 4.35, 95% CI: 2.05, 8.94). Overall, the effects in pipe/cigar smokers were intermediate between never-smokers and light cigarette smokers, although risks for lung cancer were similar to light cigarette smokers. CONCLUSION: Pipe and cigar smoking, whether primary or secondary, carries significant risk of smoking-related ill health.     

The effects of different alcoholic drinks on lipids, insulin and haemostatic and inflammatory markers in older men

Light to moderate drinking is associated with lower risk of coronary heart (CHD) than non-drinkers. We have examined the relationships between total alcohol intake and type of alcoholic beverage and several potential biological mechanisms. We carried out the study in 3158 men aged 60-79 years drawn from general practices in 24 British towns with no history of myocardial infarction, stroke or diabetes and who were not on warfarin. Total alcohol consumption showed a significant positive dose-response relationship with high density lipoprotein cholesterol (HDL-C), coagulation factor IX, haematocrit, blood viscosity, and tissue plasminogen (t-PA) antigen, and an inverse dose-response relationship with insulin, fibrinogen, von Willebrand factor (vWF) and triglycerides after adjustment for possible confounders. Total alcohol consumption showed weak associations with plasma viscosity and fibrin D-dimer, and no association with factors VII, VIII, or C-reactive protein (CRP). Wine was specifically associated with lower CRP, plasma viscosity, factor VIII and triglycerides. The findings are consistent with the suggestion that HDL-C in particular but also insulin and haemostatic factors may contribute to the beneficial effect of light to moderate drinking on risk of CHD. Wine has effects that may confer greater protection than other alcoholic beverages.     

Alcohol,body weight,and weight gain in middle-aged men

BACKGROUND: There is uncertainty as to whether regular alcohol consumption contributes directly to weight gain and the risk of obesity. OBJECTIVE: We examined the relation between alcohol intake and body weight and the association between changes in alcohol intake and in body weight over 5 y of follow-up. DESIGN: This was a prospective study of 7608 men aged 40-59 y drawn from general practices in 24 British towns, excluding persons with known diabetes. Five years after screening, 6832 men then aged 45-64 y and without diabetes completed a postal questionnaire on changes in alcohol intake and body weight. RESULTS: Mean body mass index (BMI; in kg/m(2)) and the prevalence of men with a high BMI (>or= 28; top quintile of the BMI distribution) increased significantly from the light-moderate to the very heavy alcohol intake group even after adjustment for potential confounders. Similar patterns were seen for all types and combinations of alcohol. After 5 y of follow-up, stable and new heavy drinkers (including very heavy drinkers of >or= 30 g/d) showed the greatest weight gain and had the highest prevalence rates of high BMI. Weight change patterns in heavy drinkers at baseline who reduced their intake were not significantly different from those in the stable none-occasional group but showed more weight loss and less weight gain than in the stable or new heavy drinkers. CONCLUSION: Heavy alcohol intake (>or= 30 g/d) contributes directly to weight gain and obesity, irrespective of the type of alcohol consumed.