(17/4722) Prevalence of Mycobacterium tuberculosis infection among injection drug users in Toronto.

BACKGROUND: Injection drug users are at increased risk of Mycobacterium tuberculosis infection and active tuberculosis (TB). The primary objective of this study was to determine the prevalence of M. tuberculosis infection among injection drug users in Toronto, as indicated by a positive tuberculin skin test result. An additional objective was to identify predictors of a positive skin test result in this population. METHODS: A cross-sectional study was carried out involving self-selected injection drug users in the city of Toronto. A total of 171 participants were recruited through a downtown Toronto needle-exchange program from June 1 to Oct. 31, 1996. RESULTS: Of 167 subjects tested, 155 (92.8%) returned for interpretation of their skin test result within the designated timeframe (48 to 72 hours). Using a 5-mm cut-off, the prevalence rate of positive tuberculin skin test results was 31.0% (95% confidence interval 23.8% to 38.9%). Birth outside of Canada and increasing age were both predictive of a positive result. INTERPRETATION: There is a high burden of M. tuberculosis infection in this population of injection drug users. The compliance observed with returning for interpretation of skin test results indicates that successful TB screening is possible among injection drug users.  (+info)

(18/4722) Neuropsychological and stress evaluation of a residential mercury exposure.

Residents of a former factory building converted to apartments were exposed to mercury over a 2-year period. The neurobehavioral and emotional health effects of this exposure and subsequent evacuation are presented. Urine mercury levels were measured before (urine1) and 3-10 weeks after evacuation (urine2) of the building, when neurobehavioral and psychological measures were also completed. Performance on neurobehavioral and psychologic measures were compared between subjects above and below the median for urine1 (>=19 microg/g creatinine) and were correlated with urine1 mercury levels. The high urine mercury group made more errors on a test of fine motor function and 84% of the residents reported clinically significant elevations in somatic and psychologic symptoms. Although subclinical tremor from mercury exposure may have affected subtle hand-eye coordination, other tests of motor function were not affected. Therefore, the observation of reduced hand-eye coordination may be due to chance. Significant levels of psychosocial stress were more closely associated with the evacuation necessitated by mercury exposure rather than a direct effect of mercury exposure.  (+info)

(19/4722) Cataract, glaucoma and season of birth amongst patients born on the Indian subcontinent.

The relation between the prevalence of open-angle glaucoma and of different types of cataract on the one hand and the patient's season of birth on the other was studied with special reference to natives of the Indian Subcontinent. Partial comparisons were made with results obtained on British-born patients. Both primary open-angle glaucoma (POAG) and the mixed nuclear/posterior-subcapsular type (NP) showed a statistically significant variation with the month of birth for the Asian patients, but only NP showed significant variation for the European patients in a month-by-month analysis. The Asian data are examined from the point of view of seasonal variations in maternal nutrition and of low birth-weight babies.  (+info)

(20/4722) Power-frequency electric and magnetic fields and risk of childhood leukemia in Canada.

In a case-control study of childhood leukemia in relation to exposure to power-frequency electric and magnetic fields (EMF), 399 children resident in five Canadian provinces who were diagnosed at ages 0-14 years between 1990 and 1994 (June 1995 in British Columbia and Quebec) were enrolled, along with 399 controls. Exposure assessment included 48-hour personal EMF measurement, wire coding and magnetic field measurements for subjects' residences from conception to diagnosis/reference date, and a 24-hour magnetic field bedroom measurement. Personal magnetic fields were not related to risk of leukemia (adjusted odds ratio (OR) = 0.95, p for trend = 0.73) or acute lymphatic leukemia (OR = 0.93, p for trend = 0.64). There were no clear associations with predicted magnetic field exposure 2 years before the diagnosis/reference date or over the subject's lifetime or with personal electric field exposure. A statistically nonsignificant elevated risk of acute lymphatic leukemia was observed with very high wiring configurations among residences of subjects 2 years before the diagnosis/reference date (OR = 1.72 compared with underground wiring, 95% confidence interval 0.54-5.45). These results provide little support for a relation between power-frequency EMF exposure and risk of childhood leukemia.  (+info)

(21/4722) Changing patterns of drug use among US military recruits before and after enlistment.

OBJECTIVES: The US armed forces adopted "zero tolerance" policies concerning illicit drug use in 1980 and later developed policies to discourage tobacco and alcohol abuse. This article examines drug use among young active-duty recruits both before and after enlistment, compared with nonmilitary age-mates, and documents historical shifts in such drug use across 2 decades. METHODS: Analyses employed longitudinal panel data from 20 nationally representative samples of high school seniors (cohorts of 1976-1995), each surveyed just before graduation and again within 2 years. Separate analyses for men (n = 12,082) and women (n = 15,345) contrasted those who entered military service, college, and civilian employment. RESULTS: Illicit drug use declined more among young military recruits than among their civilian counterparts. Analyses of male recruits at multiple time periods showed (1) declines in the prevalence of marijuana use and cocaine use after the initiation of routine military drug testing and (2) lower proportions of smokers of half a pack or more of cigarettes per day who entered service after the initiation of tobacco bans during basic training. CONCLUSIONS: Recent military drug policies appear to deter illicit drug use among enlistees and discourage some smokers from enlisting.  (+info)

(22/4722) Drinking and driving among US high school seniors, 1984-1997.

OBJECTIVES: This article reports the prevalence of, and trends in, driving after drinking and riding in a car with a driver who has been drinking among American high school seniors, based on data from more than a decade (1984-1997) of annual national surveys. METHODS: Logistic regressions were used to assess the effects of demographic factors (gender, region of country, population density, parental education, and race/ethnicity) and selected "lifestyle" factors (religious commitment, high school grades, truancy, illicit drug use, evenings out per week, and miles driven per week). RESULTS: Rates of adolescent driving after drinking and riding with a driver who had been drinking declined significantly from the mid-1980s to the early or mid-1990s, but the declines have not continued in recent years. Rates of driving or riding after drinking were higher among high school seniors who are male. White, living in the western and northeastern regions of the United States, and living in rural areas. Truancy, number of evenings out, and illicit drug use all related significantly positively with the dependent variables, whereas grade point average and religious commitment had a negative relationship. Miles driven per week related positively to driving after drinking.  (+info)

(23/4722) Cardiovascular risk factors in Mexican American adults: a transcultural analysis of NHANES III, 1988-1994.

OBJECTIVES: This study examined the extent to which cardiovascular disease risk factors differ among subgroups of Mexican Americans living in the United States. METHODS: Using data from a national sample (1988-1994) of 1387 Mexican American women and 1404 Mexican American men, aged 25 to 64 years, we examined an estimate of coronary heart disease mortality risk and 5 primary cardiovascular disease risk factors: systolic blood pressure, body mass index, cigarette smoking, non-high-density lipoprotein cholesterol, and type 2 diabetes mellitus. Differences in risk were evaluated by country of birth and primary language spoken. RESULTS: Estimated 10-year coronary heart disease mortality risk per 1000 persons, adjusted for age and education, was highest for US-born Spanish-speaking men and women (27.5 and 11.4, respectively), intermediate for US-born English-speaking men and women (22.5 and 7.0), and lowest for Mexican-born men and women (20.0 and 6.6). A similar pattern of higher risk among US-born Spanish-speaking men and women was demonstrated for each of the 5 cardiovascular disease risk factors. CONCLUSIONS: These findings illustrate the heterogeneity of the Mexican American population and identify a new group at substantial risk for cardiovascular disease and in need of effective heart disease prevention programs.  (+info)

(24/4722) Studies in adaption to ambient oxidant air pollution: effects of ozone exposure in Los Angeles residents vs. new arrivals.

To test the hypothesis that adaptation protecting against acute effects of ambient ozone (O3) exposures develops in Los Angeles residents, human volunteers were exposed to 0.4 ppm O3 under conditions simulating ambient pollution exposures. Blood biochemical, pulmonary physiological, and clinical responses were assessed. Los Angeles residents (N = 6) showed only minimal clinical or physiological response to O3, while new arrivals (N = 9) showed significant losses in pulmonary function and a tendency toward increased symptoms. Most biochemical responses did not differ significantly between residents and new arrivals. These results agree with others in suggesting that exposures to elevated ambient concentrations of O3 produce adaptation in a least some residents of photochemical pollution areas. The underlying mechanisms and long-term consequences of such adaptation are unknown.  (+info)