Negotiating a maze of unpaved roads in Jackson in the company car, a 13-year-old Ford Expedition with cracked seats and chipped paint, he stopped to drop off H.I.V. medication at a couple’s home. One of the men was H.I.V.-positive, the other negative; they lived in neighborhood locals call the Bottom, where every fifth or sixth home is abandoned, with broken windows, doors hanging off hinges, downed limbs and dry leaves blanketing front yards. Sturdevant banged on the door of a small house, its yard overgrown with weeds; he knew not to leave the package on the doorstep, where it could be stolen. After a while a young man emerged, shirtless, shrugging off sleep. He had just gotten out of jail. Sturdevant handed him the package, shook his hand and told him to “stay out of trouble.”
One community-based study targeting areas where men who have sex with men (MSM) meet demonstrated that an average of 44% of study participants appeared unaware of their HIV-positive status. High rates of positivity and unawareness of positive status were associated with younger participants, men of black non-Hispanic race, and lower education levels.
Several classes of antiretroviral drugs are used together to treat HIV infection. These drugs block HIV from entering human cells or block the activity of one of the enzymes HIV needs to replicate inside human cells and/or integrate its genetic material into human DNA.
Jump up ^ Barbaro, G; Barbarini, G (December 2011). “Human immunodeficiency virus & cardiovascular risk”. The Indian journal of medical research. 134 (6): 898–903. doi:10.4103/0971-5916.92634. PMC 3284097 . PMID 22310821.
Shortly after the viral capsid enters the cell, an enzyme called reverse transcriptase liberates the positive-sense single-stranded RNA genome from the attached viral proteins and copies it into a complementary DNA (cDNA) molecule. The process of reverse transcription is extremely error-prone, and the resulting mutations may cause drug resistance or allow the virus to evade the body’s immune system. The reverse transcriptase also has ribonuclease activity that degrades the viral RNA during the synthesis of cDNA, as well as DNA-dependent DNA polymerase activity that creates a sense DNA from the antisense cDNA. Together, the cDNA and its complement form a double-stranded viral DNA that is then transported into the cell nucleus. The integration of the viral DNA into the host cell’s genome is carried out by another viral enzyme called integrase.
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The final step of the viral cycle, assembly of new HIV-1 virions, begins at the plasma membrane of the host cell. The Env polyprotein (gp160) goes through the endoplasmic reticulum and is transported to the Golgi complex where it is cleaved by furin resulting in the two HIV envelope glycoproteins, gp41 and gp120. These are transported to the plasma membrane of the host cell where gp41 anchors gp120 to the membrane of the infected cell. The Gag (p55) and Gag-Pol (p160) polyproteins also associate with the inner surface of the plasma membrane along with the HIV genomic RNA as the forming virion begins to bud from the host cell. The budded virion is still immature as the gag polyproteins still need to be cleaved into the actual matrix, capsid and nucleocapsid proteins. This cleavage is mediated by the packaged viral protease and can be inhibited by antiretroviral drugs of the protease inhibitor class. The various structural components then assemble to produce a mature HIV virion. Only mature virions are then able to infect another cell.
Jump up ^ Campbell GR, Pasquier E, Watkins J, et al. (2004). “The glutamine-rich region of the HIV-1 Tat protein is involved in T-cell apoptosis”. J. Biol. Chem. 279 (46): 48197–48204. doi:10.1074/jbc.M406195200. PMID 15331610.
The course of HIV infection involves three stages: primary HIV infection, the asymptomatic phase, and AIDS. During the first stage the transmitted HIV replicates rapidly, and some persons may experience an acute flulike illness that usually persists for one to two weeks. During that time a variety of symptoms may occur, such as fever, enlarged lymph nodes, sore throat, muscle and joint pain, rash, and malaise. Standard HIV tests, which measure antibodies to the virus, are initially negative, because HIV antibodies generally do not reach detectable levels in the blood until a few weeks after the onset of the acute illness. As the immune response to the virus develops, the level of HIV in the blood decreases.
Bangui definition A points-based system used to define AIDS in countries where HIV testing is not available. It was developed by workers from the CDC and WHO at a conference held in Bangui, Central African Republic, in 1985, and gives the most points for severe weight loss, protracted asthenia, recalcitrant fever and diarrhoea. AIDS is diagnosed with scores of 12 or more.
Because many HIV-positive pregnant women are treated or take prophylactic drugs, the incidence of AIDS in children is decreasing in many countries (see Human Immunodeficiency Virus (HIV) Infection in Infants and Children).
DHHS Panel on Antiretroviral Guidelines for Adults and Adolescents. “Guidelines for the Use of Antiretroviral Agents in HIV-1 Infected Adults and Adolescents.” Washington D.C.: Department of Health and Human Services, 2017.
During viral replication, the integrated DNA provirus is transcribed into RNA, some of which then undergo RNA splicing to produce mature mRNAs. These mRNAs are exported from the nucleus into the cytoplasm, where they are translated into the regulatory proteins Tat (which encourages new virus production) and Rev. As the newly produced Rev protein is produced it moves to the nucleus, where it binds to full-length, unspliced copies of virus RNAs and allows them to leave the nucleus. Some of these full-length RNAs function as new copies of the virus genome, while others function as mRNAs that are translated to produce the structural proteins Gag and Env. Gag proteins bind to copies of the virus RNA genome to package them into new virus particles.
^ Jump up to: a b Keele BF, Jones JH, Terio KA, Estes JD, Rudicell RS, Wilson ML, Li Y, Learn GH, Beasley TM, Schumacher-Stankey J, Wroblewski E, Mosser A, Raphael J, Kamenya S, Lonsdorf EV, Travis DA, Mlengeya T, Kinsel MJ, Else JG, Silvestri G, Goodall J, Sharp PM, Shaw GM, Pusey AE, Hahn BH (2009). “Increased mortality and AIDS-like immunopathology in wild chimpanzees infected with SIVcpz”. Nature. 460 (7254): 515–519. Bibcode:2009Natur.460..515K. doi:10.1038/nature08200. PMC 2872475 . PMID 19626114.
Resistance of HIV to protease inhibitors. After the administration of a single protease inhibitor to a patient with HIV there is a precipitous fall in viral RNA levels in plasma with a half-life of approximately 2 days (top panel). This is accompanied (more…)
Many opportunistic infections that complicate HIV are reactivations of latent infections. Thus, epidemiologic factors that determine the prevalence of latent infections also influence risk of specific opportunistic infections. In many developing countries, prevalence of latent TB and toxoplasmosis in the general population is higher than that in developed countries. Dramatic increases in reactivated TB and toxoplasmic encephalitis have followed the epidemic of HIV-induced immunosuppression in these countries. Similarly in the US, incidence of coccidioidomycosis, common in the Southwest, and histoplasmosis, common in the Midwest, has increased because of HIV infection. [redirect url=’http://penetratearticles.info/bump’ sec=’7′]