Free Biology books

Hi everybody...while searching i came across the following link...here u can find many online books for the basics in biological sciences
http://www.estrellamountain.edu/faculty/farabee/biobk/biobooktoc.html

thanks

Antiretroviral Therapy in relation with Heart Attack Risk

• People infected with HIV facenearly twice the risk of heart attack that non-infected individuals do, a new study suggests. That risk remained elevated even after researchers accounted for age, high blood pressure, high cholesterol and other cardiovascular riskfactors, suggesting that the virus itself or therapies used to treat itmight somehow be harming the heart.
• In this prospective, observational study of patients infected with HIV and other retroviral diseases, a significant association with risk of myocardial infarction was found for protease-inhibitor therapy but not for therapy with nonnucleoside reverse-transcriptase inhibitors. The relative rate of myocardial infarction per year was 1.16 (95% confidence interval, 1.10 to 1.23) for protease-inhibitor therapy. The relative risk for nonnucleoside reverse-transcriptase inhibitors was 1.05 (95% confidence interval, 0.98 to 1.13). This association, of protease inhibitors and myocardial infarction, may be partly explained by the effects of protease inhibitors on serum lipid levels.
• However, experts stressed that the danger is minimal compared to the life-extending effects of these medications, called protease inhibitors. Experts first noticed a hike in heart trouble among HIV-infected people in the 1980s and early 1990s, before the advent of life-extending "highly active antiretroviral therapy" (HAART). That suggested that HIV infection, on its own, might boost cardiovascular risks. This effect was likely explained by a complex process where untreated HIV depletes the 'good' (HDL) cholesterol.