HIV infection induces both immune deficiency and immune stimulation. Central to the pathology of HIV infection is reduction in the numbers and function of CD4 T cells. Impaired functions include decreased proliferation, IL-2 receptor expression and production of lymphokines (IL-2 and gamma interferon (IFN]. HIV infection stimulates B cells and CD8 T cells. This is seen relatively soon after HIV infection. Increased activation and immaturity are seen in both these cell groups. In vitro studies confirm HIV stimulation of these cells. Studies have been conducted on patients with AIDS and opportunistic infection (OI) or Kaposi's sarcoma (KS), with AIDS-related complex (ARC) or with persistent generalized lymphadenopathy (PGL), as well as on asymptomatic HIV-seropositive and -seronegative homosexually active men. The latter group has been followed at 6-month intervals for the past 2-3 years. Those who seroconverted (became HIV-infected) were studied to investigate early changes following HIV infection. To delineate the immunopathology of infection with HIV, serial testing of seropositive individuals was carried out to determine the rate of CD4-T-cell reduction. Lowered CD4-T-cell number and percentage and CD4/CD8 ratio correlate with the occurrence of AIDS and with survival after AIDS-KS diagnosis. Seropositive individuals, however, differed markedly in the rate of CD4-T-cell reduction; in some, no reduction in CD4 cells occurred over a two-year period of observation. We propose that, in individuals in which CD4 levels have reached a plateau, effective host resistance to further CD4 cytoreduction has occurred.

AIDS-Related Complex↗

PubMedDate not supplied

Population attributable fraction of stroke incidence in middle-aged and elderly people: contributions of hypertension, smoking and atrial fibrillation.

We determined the population attributable fraction (PAF) of stroke due to hypertension (HT), atrial fibrillation (Af) and smoking in a Japanese community. Residents of Shibata (n = 2,302) who were surveyed initially in 1977 were followed until 1997. Two hundred and thirteen first strokes occurred. Among those 40-64 years of age, the risk ratio (RR) of Af was 11.24, followed by untreated HT (3.61), uncontrolled HT (3.69) and smoking (1.84). The PAFs, however, were 14.9% for smoking, 13.5% for untreated HT, 8.6% for uncontrolled HT and 3.6% for Af. Among those over 65 years, only Af was significant (RR 3.89) and the PAF was 6.0%. Determination of PAFs is also essential for designing effective stroke prevention programs in communities.

Adult↗

PubMedDate not supplied

Incidence of stroke in Shibata, Japan: 1976-1978.

A stroke registry was established in Shibata City, Niigata Prefecture, Japan (population 75,000) in 1976. WHO recommendations for criteria were followed. This paper reports stroke incidence for the initial 3 years of the registry: 1976 through 1978. All living patients were examined clinically by a staff physician. Only patients with a diagnosis of first stroke were included in the study. Sensitivity of the referral system was estimated at 85 + %, comparable to that in American studies. Average annual incidence per 1,000 in resident greater than or equal to 20 years was 2.61 for all strokes (3.42 for males; 1.88 for females), 0.20 for subarachnoid hemorrhage, 0.61 for cerebral hemorrhage, 1.51 for cerebral infarction - rates similar to those reported 10-20 years previously for the United States. The male-female ratio, 2:1, reflected a high rate among males, low among females. Rats among Shibata males were higher than 1972 U.S. rates reported by the Epidemiologic Study Group; rates among Shibata females were lower than corresponding U.S. rates. Incidence of all strokes combined increased with age, the age relationship being strongest for cerebral infarction. No subarachnoid hemorrhage was observed in Shibata residents greater than or equal to 70 years of age.

Adult↗