Estimating the number of people at risk for and living with HIV in China in 2005: methods and results.

BACKGROUND: No new estimates of HIV infection have been available for China since 2003. However, since then, data availability has increased dramatically. OBJECTIVES: To use internationally recommended methods to make new estimates of the number of people exposed to HIV in China, the number living with HIV, and the number of new HIV infections and deaths in 2005. METHODS: The UNAIDS Workbook method was adapted to meet the needs of China. Local data were used to estimate the size of each risk population and HIV prevalence by risk group for every prefecture. These estimates were combined into provincial and national estimates. The UNAIDS Estimates and Projections Package and Spectrum were used to derive estimates of incidence and mortality from prevalence data, taking into account treatment. RESULTS: It was estimated that 650,000 people are living with HIV/AIDS in China (range 540,000-760,000), of whom 70,000 were newly infected in 2005 (range 60,000-80,000). Between 20,000 and 30,000 people are estimated to have died of HIV in 2005. The new estimate compares with an estimate of 840,000 people living with HIV/AIDS in 2003 (range 650,000-1,020,000). The estimated number of infected former plasma donors fell from 199,000 to 55,000. Infections remain concentrated among drug injectors, those buying and selling sex, and men who have sex with men. CONCLUSION: The new estimates are based on a much wider range of surveillance data as well as mass screening of former plasma donors, and are made at the prefecture level. More limited data from high prevalence provincial surveillance sites led to past estimates that now seem too high. New infections outpace death, and the HIV epidemic in China is still growing.

Differences in HIV disease progression by injection drug use and by sex in the era of highly active antiretroviral therapy.

BACKGROUND: The advent of highly active antiretroviral therapy (HAART) has reduced the incidence of most AIDS-related opportunistic illnesses (OI) and death in HIV-infected individuals. We investigated whether there are demographic disparities in HIV disease progression in the HAART era compared with before. METHODS: HIV-infected patients in an urban HIV clinical practice in the USA were compared using survival methods for time to a new AIDS-defining OI or death in therapeutic era 1 (monotherapy and combination therapy; 1990--1995; n = 2016) versus era 2 (HAART; 1996--1999; n = 2165). RESULTS: A total of 1037 (51.4%) events occurred in era 1; 666 (30.8%) events occurred in era 2. In women, the median disease-free survival time increased by 14% (CD4 cell counts > 200 cells/mm(3) at baseline) and 34% (CD4 cell counts < or = 200) in era 2 compared with era 1, whereas for men it increased by 43 and 100%. The relative hazard (RH) of progression for women compared with men in era 2 compared with era 1 was 1.34. For injecting drug use (IDU), disease-free survival time increased by 16% and 34% in era 2 compared with era 1, whereas non-IDU improved by 65 and 135%. The RH of progression for IDU compared with non-IDU in era 2 compared with era 1 was 1.39. No significant differences were detected by race or other HIV transmission risk group. CONCLUSION: Disease-free survival time was extended with the use of HAART, but these gains were not equally distributed by sex and IDU in our cohort.

Allosteric intermediates indicate R2 is the liganded hemoglobin end state.

Hemoglobin has been a long-standing paradigm for understanding protein allostery. Here, the x-ray structures of two chemically crosslinked, fully liganded hemoglobins, alpha2beta82CA82beta and alpha2beta82ND82beta, are described at 2.3 A and 2.6 A resolution, respectively. Strikingly, these crosslinked hemoglobins assume intermediate conformations that lie between those of R and the controversial liganded hemoglobin state R2 rather than between R and T. Thus, these structures support only a T left and right arrow R left and right arrow R2 allosteric pathway and underscore the physiological importance of the R2 conformation.