HIV infection
Scientists have piggybacked antibodies onto radioactive payloads to deliver doses of radiation that selectively target and destroy microbial and HIV-infected cells
An investigational vaginal gel intended to prevent HIV infection in women has demonstrated encouraging signs of success in a clinical trial conducted in Africa and the United States.
Scientists have shown that HIV faces a genetic "bottleneck" when the virus is transmitted heterosexually from one person to another, by way of the genital mucosa. The results, published January 23 in the open-access journal PLoS Pathogens, explain why prior infection by other sexually-transmitted diseases (STDs) makes individuals more susceptible to HIV infection.
A topical microbicide that silences two genes can safely protect against genital herpes infection for as long as one week.
The results of the world's first phase 3 HIV vaccine efficacy trial are reported in the March 1 issue of The Journal of Infectious Diseases, now available online. Although the vaccine was ineffective in preventing HIV infection, the trial represents a landmark in the fight against HIV and offers the scientific community a foundation on which to build future trials. The multi-centered trial, conducted in the United States and the Netherlands and completed in 2003, is described in two papers by the rgp120 HIV Vaccine Study Group, and Peter B. Gilbert and colleagues, which address the vaccine efficacy results and the immunologic responses of the study participants.
The Centers for Disease Control and Prevention (CDC), an agency of the Department of Health and Human Services, today announced new federal guidelines for the use of antiretroviral drugs to prevent HIV infection after exposure to HIV through sexual intercourse, sexual assault, injection drug use, or accidents. "Using antiretroviral drugs after exposure is an important safety net to prevent HIV infection in certain cases," said Ronald O. Valdiserri, MD, MPH, deputy director of CDC's National Center for HIV, STD and TB Prevention. "But the drugs are not a substitute for abstinence, mutual monogamy, or consistent and correct condom use, and should not be viewed as a quick fix."
The first study to examine the probability of HIV infection per act of heterosexual sex among a population with multiple sexual partners has found that uncircumcised men have more than twice the risk of acquiring HIV than do circumcised men. In the study, published in the Feb. 15 issue of The Journal of Infectious Diseases, now available online, Jared Baeten and colleagues from the United States and Kenya collected detailed sexual data from a group of male Kenyan truckers and, using statistical models, developed infectivity measures that estimate the per-sexual-act probability of HIV transmission. The study is the first to calculate the probability of infection for men who have multiple, concurrent heterosexual partners, which was found to be significantly higher than infectivity rates calculated in the past from studies of monogamous couples. Their results may help explain the rapid spread of HIV in settings where circumcision is not common and multiple sexual partnerships are.
The risk of tuberculosis infection doubles within one year of HIV infection, according to a study published in the Jan. 15 issue of The Journal of Infectious Diseases, now available online. Scientists previously assumed that there was no increase in tuberculosis risk within the first few years of HIV infection. Pam Sonnenberg of the London School of Hygiene and Tropical Medicine and colleagues were therefore surprised by the results of their research on the two infections, which they conducted in South African gold miners.
A team of researchers based partly in South Africa has identified a key set of immune system molecules that helps determine how effectively a person resists infection with human immunodeficiency virus (HIV). Their work shows that mothers with a specific type of genetic makeup may be less likely to pass HIV to their offspring. The finding has important implications for the development of vaccines to combat the AIDS epidemic.
Scientists at the U.S. Department of Energy's Brookhaven National Laboratory have discovered a key mechanism in the brains of people with human immunodeficiency virus (HIV) dementia. The study is the first to document decreases in the neurotransmitter dopamine in those with the condition, and may lead to new, more effective therapies. HIV dementia is a type of cognitive decline that is more common in the later stages of HIV infection.
Scientists have for the first time found AIDS patients infected simultaneously with two different forms of drug-resistant HIV. This infection with a second HIV virus is called superinfection. ''These emerging drug resistant viruses present a treatment challenge and the existing drug cocktails will need to be tailored accordingly.''
Researchers have discovered new information about how human immunodeficiency virus, the virus that causes acquired immune deficiency, possibly evades eradication from the body. In a new study, scientists identified several possible gene targets and two drugs to flush out long-lasting HIV reservoirs that current treatments do not affect. They also established a connection between HIV and several other genes not previously associated with the virus and found new possible targets for blocking HIV replication.
A government policy of providing HIV-infected citizens with free access to potent regimens of antiretroviral drugs reduced the rate of HIV transmission by 53% in Taiwan, according to a new study. Using public health surveillance data, investigators led by Chi-Tai Fang and Jung-Der Wang of National Taiwan University evaluated how cost-free provision of an anti-HIV regimen known as highly active antiretroviral therapy (HAART) affected the evolution of the HIV epidemic in Taiwan. Previous research has shown that HAART, which suppresses the level of HIV, prolongs the survival of HIV-infected individuals and reduces rates of mother-to-child and heterosexual transmission of the virus.
A protein that the body uses to attack the AIDS virus is actually a stealthy defense mechanism that evolved 32 million years before the emergence of HIV, according to new findings. The work hinges on a recently discovered protein called Apobec3G, which has been generating some buzz in the scientific community for its potential in shedding light on the genetic mechanisms of HIV prevention. The protein defends cells from HIV infection by causing mutations in the genetic material within the virus.
Increasing the body's production of growth hormone may be an effective treatment for HIV lipodystrophy, a syndrome involving the redistribution of fat and other metabolic changes in those receiving combination drug therapy for HIV infection. Researchers from Massachusetts General Hospital (MGH) report that administration of growth-hormone-releasing hormone to a group of men with HIV lipodystrophy significantly improved fat distribution with no negative side effects.
