Levels of HIV-infected peripheral blood cells remain stable throughout the natural history of HIV-1 infection. Swiss HIV Cohort Study.

To clarify the relationship between the number of provirus-bearing peripheral blood mononuclear cells (PBMC) and HIV-1 disease progression during the natural history of infection. Twenty-four HIV-1-infected subjects with known seroconversion dates and long-term follow-up were retrospectively identified using the Swiss HIV Cohort Database. PBMC specimens from this cohort were retrieved from storage for analysis. Infected PBMC equivalents were determined by HIV-1 DNA quantitative competitive (QC)-PCR. The results were analysed with respect to HIV-1 disease stage and compared with a mathematical model of long-term HIV-1 disease progression. PBMC HIV-1 DNA did not correlate with major indices of disease progression, including time following primary infection, time before reaching a CD4 cell count less than 200 x 10(6)/l, and time before death. The number of PBMC harbouring HIV-1 provirus was relatively constant throughout the clinical stages of HIV-1 infection, consistent with simulated data from a mathematical model of long-term HIV-1 infection. We also showed that a biased interpretation of the QC-PCR data may arise when the values are expressed as HIV-1 DNA copies per PBMC or per CD4 cell. This analysis suggests that levels of provirus-bearing PBMC remain constant during the natural course of HIV-1 infection, whereas plasma virus load typically increases logarithmically during the same period. The hypothesis that plasma virus levels are directly related to the number of infected cells may deserve reconsideration

Highly active antiretroviral therapy during early HIV infection reverses T-cell activation and maturation abnormalities. Swiss HIV Cohort Study.

To evaluate the impact of early initiation of highly active antiretroviral therapy (HAART) on disease-induced T-cell activation and maturation abnormalities during asymptomatic HIV infection. A prospective open-label trial of zidovudine, lamivudine and ritonavir in treatment-naive asymptomatic HIV-infected individuals with CD4 cells > or = 400 x 10(6)/l. Peripheral blood CD4+ and CD8+ T cells derived from 15 asymptomatic HIV-infected individuals (median baseline CD4+ cells, 608 x 10(6)/l; CD8+ cells, 894 x 10(6)/l; plasma HIV RNA, 3.93 log10 copies/ml) undergoing therapy with zidovudine (300 mg twice daily), lamivudine (150 mg twice daily), and ritonavir (600 mg twice daily) were assessed for changes in expression of phenotypic markers of T-cell activation (HLA-DR and CD38) and maturation (CD45RA and CD45RO). At weeks 0, 2, 4, 8, 12, 16, 20 and 24, T-cell subsets were quantified by flow cytometry and plasma HIV viral loads determined using reverse transcription PCR. HAART-induced decrease in plasma HIV RNA levels coincided with a significant reduction in numbers of activated CD4+/HLA-DR+ (maximum change, -36%; P < or = 0.05), CD8+/HLA-DR+ (maximum change, -66%; P < or = 0.005) and CD8+/CD38+ (maximum change, -51%; P < or = 0.01) T cells. A concomitant significant increase in numbers of naive CD4+/CD45RA+ (maximum change, +12%; P < or = 0.005) and memory CD4+/CD45RO+ (maximum change, +6%; P < or = 0.05) T cells was also evident, which contrasted with a significant decrease in memory CD8+/CD45RO+ cells (maximum change, -42%; P < or = 0.005). The observed ability of HAART during early asymptomatic HIV infection to initiate rapid reversal of disease-induced T-cell activation and maturation abnormalities, while preserving pretherapy levels of immune function, supports the concept that therapeutic advantage is to be gained by commencing early aggressive antiretroviral therapy

Social Psychology and the Stimulation of Recycling Behaviors: The Block Leader Approach

Recycling has been touted as an important part of the solution to solid waste problems, yet most citizens still do not recycle, even when recycling is made easy by curbside pickups. This field experiment was designed to increase participation in a city-sponsored curbside recycling program. Citizens who consistently recycled with the city program were approached and asked to be recycling block leaders. Those who agreed were instructed to give approximately 10 nonrecycling neighbors a persuasive communication advocating recycling and special recycling bags. A second treatment group (of nonrecycling households) had bags and the communication left at their door. Results indicated that the curbside recycling of the two experimental groups differed significantly from one another (with the block leader group recycling more), and both differed significantly from a control group receiving no treatment. A discussion of past recycling intervention research and its feasibility for community application is included