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OBJECTIVE--To describe the human immunodeficiency virus (HIV) epidemic among socially and educationally disadvantaged young persons in the United States. DESIGN.-We analyzed demographic and geographic findings from the screening of Job Corps students for antibody to HIV. SETTING--The Job Corps is a federal training program for disadvantaged, out-of-school youth. POPULATION SCREENED--Residential students aged 16 to 21 years who entered the Job Corps from October 1987 through February 1990. MAIN OUTCOME MEASURE--Rates of observed HIV infection in entering students, stratified by demographic and geographic features. RESULTS--Of 137,209 Job Corps students screened, 488 were HIV seropositive (3.6 per 1000), a seroprevalence rate higher than that among military applicants of the same age. Overall seroprevalence was slightly higher in male (3.7 per 1000) than in female (3.2 per 1000) Job Corps students, but among those students aged 16 and 17 years, seroprevalence was higher among females (2.3 per 1000) than among males (1.5 per 1000) (P less than .05). For students aged 16 to 21 years, seroprevalence increased with year of age: 1.8 per 1000 per year for males and 0.7 per 1000 per year for females. Among those aged 21 years, HIV prevalence was 8.9 per 1000. For black and Hispanic students from large Northeastern cities, seroprevalence increased by 4.3 per 1000 per year of age and reached 24.8 per 1000 (one of 40) in students aged 21 years. However, among students from rural areas and small towns, HIV seroprevalence was disproportionately high in the Southeast. Compared with recently described US patients with the acquired immunodeficiency syndrome, HIV-infected students who entered the Job Corps were much more likely to be female. CONCLUSIONS--These findings show that disadvantaged, out-of-school adolescents are at high risk for HIV infection. The screening results identified surprisingly high seroprevalence in the southeastern United States and demonstrated a marked shift in the HIV epidemic to young women. Controlling the HIV epidemic among teenagers must include interventions that will reach adolescents early and outside of the formal educational system.  相似文献   
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Muscle biopsies from the apex of both sides of the curve of 31 patients with idiopathic scoliosis showed abnormalities in fiber-type distribution in 68 per cent and in fiber size in 55 per cent. There was no preference for either side. Type 1 fiber predominance was as common as type 1 fiber deficiency. Atrophy occurred in 33 per cent and affected mainly type 1 fibers: atrophy of type 2 fibers was rare. Hypertrophy was limited to type 2 fibers, and occurred in 26 per cent. The strength factor for type 1 fibers exceeded that for type 2. Type 2A fibers were no larger than 2B fibers: there was a large type 2A predominance, more so on the convex side. Most of the muscle changes appear to be secondary and compensatory: none suggests a pathogenesis for the curve.  相似文献   
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