HIV seroprevalence among participants at a Supervised Injection Facility in Vancouver, Canada: implications for prevention, care and treatment

North America's first government sanctioned medically supervised injection facility (SIF) was opened during September 2003 in Vancouver, Canada. This was in response to a large open public drug scene, high rates of HIV and hepatitis C transmission, fatal drug overdoses, and poor health outcomes among the city's injection drug users. Between December 2003 and April 2005, a representative sample of 1,035 SIF participants were enrolled in a prospective cohort that required completing an interviewer-administered questionnaire and providing a blood sample for HIV testing. HIV infection was detected in 170/1007 (17%) participants and was associated with Aboriginal ethnicity (adjusted Odds Ratio [aOR], 2.70, 95% Confidence Interval [95% CI], 1.84–3.97), a history of borrowing used needles/syringes (aOR, 2.0, 95% CI, 1.37–2.93), previous incarceration (aOR, 1.87, 95% CI, 1.11–3.14), and daily injection cocaine use (aOR, 1.42, 95% CI, 1.00–2.03). The SIF has attracted a large number of marginalized injection drug users and presents an excellent opportunity to enhance HIV prevention through education, the provision of sterile injecting equipment, and a supervised environment to self-inject. In addition, the SIF is an important point of contact for HIV positive individuals who may not be participating in HIV care and treatment.     

Inflammatory bowel disease in children and adolescents in Sweden, 1984-1995

BACKGROUND: A prospective study of inflammatory bowel disease (IBD) in Sweden was performed to investigate whether the incidence and morbidity have changed from 1984 through 1995. METHODS: Children 15 years of age or less with IBD were included--i.e., those with a definite diagnosis of ulcerative colitis (UC) and Crohn's disease (CD) and those classified as having indeterminate colitis (IC) and probable Crohn's disease (PCD). The study covered 56.5% of the pediatric population of Sweden. RESULTS: The diagnosis of IBD was made in 639 children, which corresponds to a mean annual incidence of 5.8 per 100,000. The incidence increased from 4.6 per 100,000 per year from 1984 through 1986 to 7.0 from 1993 through 1995. It reflected an increase in UC from 1.4 to 3.2 per 100,000 per year, which is a significant yearly percentage of increase (8%; confidence interval, 2-14%; P < 0.05). In contrast, no change occurred in the incidence of CD (1.2-1.3 per 100,000). The incidence of IC and PCD also remained fairly stable. The percentages of children who underwent surgery decreased from 17.3% in the first 6 years to 4.6% in the last 6 years (P < 0.001). Surgery was performed in 27.7% of CD and 5.3% of UC cases. The median age at diagnosis was 12.2 years for UC, 13.0 years for CD, 11.2 for IC, and 11.2 for PCD. At diagnosis, 48 children (7.5%) were 5 years of age or less, whereas most of the patients were 11 years of age or more (398 children, 62.3%). CONCLUSIONS: In Sweden, the incidence of UC has increased, whereas that of CD remains the same. A significant number of children were classified with IC and PCD. In most children, IBD was diagnosed when they were 11 years old or more, but some cases were detected even in those below 6 years of age. A decrease in the frequency of surgery occurred during the study.     

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.      

EFFECTS OF LIFESTYLE, COPING AND WORK-RELATED STRESS ON BLOOD PRESSURE IN OFFICE WORKERS

1. The relative importance of perceived stress compared with coping behaviours and ‘lifestyle’ characteristics known to influence blood pressure were studied in 337 male and 317 female office workers. 2. Males had significantly higher mean systolic (P<0.01; t-test, 652 d.f.) and diastolic (P<0.01; t-test, 652 d.f.) blood pressure and unhealthier lifestyles than females, particularly in the areas of alcohol intake (P<0.01; t-test, 653 d.f.) and diet (P= 0.01; t-test, 663 d.f.). 3. In males drinking alcohol was correlated to job and home/work stress (P<0.05), and eating more atherogenic foods was correlated to home/work stress (P<0.05). 4. Coping by food and drug consumption was correlated with job and home/work stress (P <0.05) in males; avoidance/ denial coping was correlated with job stress in both males and females (P<0.001) and to home/work stress (P<0.001) in males only. Blood pressure was not correlated with stress in males or females. 5. In age-adjusted regression analyses body mass index (BMI) and lifestyle (physical inactivity, alcohol consumption and diet) made significant contributions to systolic (P= 0.02) and diastolic (P<0.01) blood pressure and, in separate analyses, coping contributed significantly to diastolic blood pressure (P<0.01) in males. Stress made no additional contribution to blood pressure in either analysis. 6. After including age, BMI, lifestyle and coping in males ‘lifestyle’ still contributed to systolic and diastolic blood pressure and coping made a significant additional contribution to diastolic blood pressure. Neither lifestyle or coping contributed significantly to blood pressure in females. 7. Thus obesity, alcohol, physical activity and diet had dominant effects on blood pressure; while any effects of job stress were indirect and related to maladaptive coping, particularly in males.     

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Postradiation volume changes in gamma unit-treated cerebral arteriovenous malformations

Postradiation changes in angiographically determined nidus volume were quantitatively studied in 22 arteriovenous malformation (AVM) cases treated by gamma unit radiosurgery. The postradiosurgical decrease was statistically significant by post-treatment year 2 (p < .05). In children, AVMs tended to be obliterated more quickly than in adults. Volume reduction was more rapid in nidi receiving 25 Gy or more than in those receiving less than 25 Gy (p < .01). However, there were no significant differences in nidus volume decrease between these two dose groups at the second or third postradiosurgical year. Dose response curves were obtained 1, 2, and 3 years following treatment.