Antiretroviral Therapy, Highly Active: Drug regimens, for patients with HIV INFECTIONS, that aggressively suppress HIV replication. The regimens usually involve administration of three or more different drugs including a protease inhibitor.HIV Infections: Includes the spectrum of human immunodeficiency virus infections that range from asymptomatic seropositivity, thru AIDS-related complex (ARC), to acquired immunodeficiency syndrome (AIDS).Anti-HIV Agents: Agents used to treat AIDS and/or stop the spread of the HIV infection. These do not include drugs used to treat symptoms or opportunistic infections associated with AIDS.Anti-Retroviral Agents: Agents used to treat RETROVIRIDAE INFECTIONS.CD4 Lymphocyte Count: The number of CD4-POSITIVE T-LYMPHOCYTES per unit volume of BLOOD. Determination requires the use of a fluorescence-activated flow cytometer.Viral Load: The quantity of measurable virus in a body fluid. Change in viral load, measured in plasma, is sometimes used as a SURROGATE MARKER in disease progression.HIV-1: The type species of LENTIVIRUS and the etiologic agent of AIDS. It is characterized by its cytopathic effect and affinity for the T4-lymphocyte.Acquired Immunodeficiency Syndrome: An acquired defect of cellular immunity associated with infection by the human immunodeficiency virus (HIV), a CD4-positive T-lymphocyte count under 200 cells/microliter or less than 14% of total lymphocytes, and increased susceptibility to opportunistic infections and malignant neoplasms. Clinical manifestations also include emaciation (wasting) and dementia. These elements reflect criteria for AIDS as defined by the CDC in 1993.HIV: Human immunodeficiency virus. A non-taxonomic and historical term referring to any of two species, specifically HIV-1 and/or HIV-2. Prior to 1986, this was called human T-lymphotropic virus type III/lymphadenopathy-associated virus (HTLV-III/LAV). From 1986-1990, it was an official species called HIV. Since 1991, HIV was no longer considered an official species name; the two species were designated HIV-1 and HIV-2.AIDS-Related Opportunistic Infections: Opportunistic infections found in patients who test positive for human immunodeficiency virus (HIV). The most common include PNEUMOCYSTIS PNEUMONIA, Kaposi's sarcoma, cryptosporidiosis, herpes simplex, toxoplasmosis, cryptococcosis, and infections with Mycobacterium avium complex, Microsporidium, and Cytomegalovirus.Reverse Transcriptase Inhibitors: Inhibitors of reverse transcriptase (RNA-DIRECTED DNA POLYMERASE), an enzyme that synthesizes DNA on an RNA template.Drug Resistance, Viral: The ability of viruses to resist or to become tolerant to chemotherapeutic agents or antiviral agents. This resistance is acquired through gene mutation.HIV Protease Inhibitors: Inhibitors of HIV PROTEASE, an enzyme required for production of proteins needed for viral assembly.RNA, Viral: Ribonucleic acid that makes up the genetic material of viruses.Stavudine: A dideoxynucleoside analog that inhibits reverse transcriptase and has in vitro activity against HIV.Zidovudine: A dideoxynucleoside compound in which the 3'-hydroxy group on the sugar moiety has been replaced by an azido group. This modification prevents the formation of phosphodiester linkages which are needed for the completion of nucleic acid chains. The compound is a potent inhibitor of HIV replication, acting as a chain-terminator of viral DNA during reverse transcription. It improves immunologic function, partially reverses the HIV-induced neurological dysfunction, and improves certain other clinical abnormalities associated with AIDS. Its principal toxic effect is dose-dependent suppression of bone marrow, resulting in anemia and leukopenia.South Africa: A republic in southern Africa, the southernmost part of Africa. It has three capitals: Pretoria (administrative), Cape Town (legislative), and Bloemfontein (judicial). Officially the Republic of South Africa since 1960, it was called the Union of South Africa 1910-1960.Nevirapine: A potent, non-nucleoside reverse transcriptase inhibitor used in combination with nucleoside analogues for treatment of HIV INFECTIONS and AIDS.Medication Adherence: Voluntary cooperation of the patient in taking drugs or medicine as prescribed. This includes timing, dosage, and frequency.Benzoxazines: OXAZINES with a fused BENZENE ring.HIV-Associated Lipodystrophy Syndrome: Defective metabolism leading to fat maldistribution in patients infected with HIV. The etiology appears to be multifactorial and probably involves some combination of infection-induced alterations in metabolism, direct effects of antiretroviral therapy, and patient-related factors.Infectious Disease Transmission, Vertical: The transmission of infectious disease or pathogens from one generation to another. It includes transmission in utero or intrapartum by exposure to blood and secretions, and postpartum exposure via breastfeeding.Cohort Studies: Studies in which subsets of a defined population are identified. These groups may or may not be exposed to factors hypothesized to influence the probability of the occurrence of a particular disease or other outcome. Cohorts are defined populations which, as a whole, are followed in an attempt to determine distinguishing subgroup characteristics.Drug Therapy, Combination: Therapy with two or more separate preparations given for a combined effect.HIV Seropositivity: Development of neutralizing antibodies in individuals who have been exposed to the human immunodeficiency virus (HIV/HTLV-III/LAV).Immune Reconstitution Inflammatory Syndrome: Exuberant inflammatory response towards previously undiagnosed or incubating opportunistic pathogens. It is frequently seen in AIDS patients following HAART.Ritonavir: An HIV protease inhibitor that works by interfering with the reproductive cycle of HIV. It also inhibits CYTOCHROME P-450 CYP3A.Viremia: The presence of viruses in the blood.Patient Compliance: Voluntary cooperation of the patient in following a prescribed regimen.CD4-Positive T-Lymphocytes: A critical subpopulation of T-lymphocytes involved in the induction of most immunological functions. The HIV virus has selective tropism for the T4 cell which expresses the CD4 phenotypic marker, a receptor for HIV. In fact, the key element in the profound immunosuppression seen in HIV infection is the depletion of this subset of T-lymphocytes.Lopinavir: An HIV protease inhibitor used in a fixed-dose combination with RITONAVIR. It is also an inhibitor of CYTOCHROME P-450 CYP3A.Lamivudine: A reverse transcriptase inhibitor and ZALCITABINE analog in which a sulfur atom replaces the 3' carbon of the pentose ring. It is used to treat HIV disease.Treatment Outcome: Evaluation undertaken to assess the results or consequences of management and procedures used in combating disease in order to determine the efficacy, effectiveness, safety, and practicability of these interventions in individual cases or series.Uganda: A republic in eastern Africa, south of SUDAN and west of KENYA. Its capital is Kampala.Organophosphonates: Carbon-containing phosphonic acid compounds. Included under this heading are compounds that have carbon bound to either OXYGEN atom or the PHOSPHOROUS atom of the (P=O)O2 structure.Treatment Failure: A measure of the quality of health care by assessment of unsuccessful results of management and procedures used in combating disease, in individual cases or series.Pregnancy Complications, Infectious: The co-occurrence of pregnancy and an INFECTION. The infection may precede or follow FERTILIZATION.Indinavir: A potent and specific HIV protease inhibitor that appears to have good oral bioavailability.AIDS Dementia Complex: A neurologic condition associated with the ACQUIRED IMMUNODEFICIENCY SYNDROME and characterized by impaired concentration and memory, slowness of hand movements, ATAXIA, incontinence, apathy, and gait difficulties associated with HIV-1 viral infection of the central nervous system. Pathologic examination of the brain reveals white matter rarefaction, perivascular infiltrates of lymphocytes, foamy macrophages, and multinucleated giant cells. (From Adams et al., Principles of Neurology, 6th ed, pp760-1; N Engl J Med, 1995 Apr 6;332(14):934-40)Botswana: A republic in southern Africa, between NAMIBIA and ZAMBIA. It was formerly called Bechuanaland. Its capital is Gaborone. The Kalahari Desert is in the west and southwest.Lymphoma, AIDS-Related: B-cell lymphoid tumors that occur in association with AIDS. Patients often present with an advanced stage of disease and highly malignant subtypes including BURKITT LYMPHOMA; IMMUNOBLASTIC LARGE-CELL LYMPHOMA; PRIMARY EFFUSION LYMPHOMA; and DIFFUSE, LARGE B-CELL, LYMPHOMA. The tumors are often disseminated in unusual extranodal sites and chromosomal abnormalities are frequently present. It is likely that polyclonal B-cell lymphoproliferation in AIDS is a complex result of EBV infection, HIV antigenic stimulation, and T-cell-dependent HIV activation.Drug Resistance, Multiple, Viral: The ability of viruses to resist or to become tolerant to several structurally and functionally distinct drugs simultaneously. This resistance phenotype may be attributed to multiple gene mutation.PyrimidinonesLost to Follow-Up: Study subjects in COHORT STUDIES whose outcomes are unknown e.g., because they could not or did not wish to attend follow-up visits.(from Dictionary of Epidemiology, 5th ed.)Cytomegalovirus Retinitis: Infection of the retina by cytomegalovirus characterized by retinal necrosis, hemorrhage, vessel sheathing, and retinal edema. Cytomegalovirus retinitis is a major opportunistic infection in AIDS patients and can cause blindness.Didanosine: A dideoxynucleoside compound in which the 3'-hydroxy group on the sugar moiety has been replaced by a hydrogen. This modification prevents the formation of phosphodiester linkages which are needed for the completion of nucleic acid chains. Didanosine is a potent inhibitor of HIV replication, acting as a chain-terminator of viral DNA by binding to reverse transcriptase; ddI is then metabolized to dideoxyadenosine triphosphate, its putative active metabolite.Adenine: A purine base and a fundamental unit of ADENINE NUCLEOTIDES.Nelfinavir: A potent HIV protease inhibitor. It is used in combination with other antiviral drugs in the treatment of HIV in both adults and children.Coinfection: Simultaneous infection of a host organism by two or more pathogens. In virology, coinfection commonly refers to simultaneous infection of a single cell by two or more different viruses.Malawi: A republic in southern Africa east of ZAMBIA and MOZAMBIQUE. Its capital is Lilongwe. It was formerly called Nyasaland.Drug Administration Schedule: Time schedule for administration of a drug in order to achieve optimum effectiveness and convenience.Prospective Studies: Observation of a population for a sufficient number of persons over a sufficient number of years to generate incidence or mortality rates subsequent to the selection of the study group.Directly Observed Therapy: A treatment method in which patients are under direct observation when they take their medication or receive their treatment. This method is designed to reduce the risk of treatment interruption and to ensure patient compliance.Drug Monitoring: The process of observing, recording, or detecting the effects of a chemical substance administered to an individual therapeutically or diagnostically.HIV Reverse Transcriptase: A reverse transcriptase encoded by the POL GENE of HIV. It is a heterodimer of 66 kDa and 51 kDa subunits that are derived from a common precursor protein. The heterodimer also includes an RNAse H activity (RIBONUCLEASE H, HUMAN IMMUNODEFICIENCY VIRUS) that plays an essential role the viral replication process.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Retrospective Studies: Studies used to test etiologic hypotheses in which inferences about an exposure to putative causal factors are derived from data relating to characteristics of persons under study or to events or experiences in their past. The essential feature is that some of the persons under study have the disease or outcome of interest and their characteristics are compared with those of unaffected persons.Dideoxynucleosides: Nucleosides that have two hydroxy groups removed from the sugar moiety. The majority of these compounds have broad-spectrum antiretroviral activity due to their action as antimetabolites. The nucleosides are phosphorylated intracellularly to their 5'-triphosphates and act as chain-terminating inhibitors of viral reverse transcription.Oxazines: Six-membered heterocycles containing an oxygen and a nitrogen.Risk Factors: An aspect of personal behavior or lifestyle, environmental exposure, or inborn or inherited characteristic, which, on the basis of epidemiologic evidence, is known to be associated with a health-related condition considered important to prevent.Lipodystrophy: A collection of heterogenous conditions resulting from defective LIPID METABOLISM and characterized by ADIPOSE TISSUE atrophy. Often there is redistribution of body fat resulting in peripheral fat wasting and central adiposity. They include generalized, localized, congenital, and acquired lipodystrophy.Africa South of the Sahara: All of Africa except Northern Africa (AFRICA, NORTHERN).Cote d'Ivoire: A republic in western Africa, south of MALI and BURKINA FASO, bordered by GHANA on the east. Its administrative capital is Abidjan and Yamoussoukro has been the official capital since 1983. The country was formerly called Ivory Coast.Africa, Southern: The geographical area of Africa comprising ANGOLA; BOTSWANA; LESOTHO; MALAWI; MOZAMBIQUE; NAMIBIA; SOUTH AFRICA; SWAZILAND; ZAMBIA; and ZIMBABWE.Zambia: A republic in southern Africa, south of DEMOCRATIC REPUBLIC OF THE CONGO and TANZANIA, and north of ZIMBABWE. Its capital is Lusaka. It was formerly called Northern Rhodesia.HIV Wasting Syndrome: Involuntary weight loss of greater than 10 percent associated with intermittent or constant fever and chronic diarrhea or fatigue for more than 30 days in the absence of a defined cause other than HIV infection. A constant feature is major muscle wasting with scattered myofiber degeneration. A variety of etiologies, which vary among patients, contributes to this syndrome. (From Harrison's Principles of Internal Medicine, 13th ed, p1611).Cross-Sectional Studies: Studies in which the presence or absence of disease or other health-related variables are determined in each member of the study population or in a representative sample at one particular time. This contrasts with LONGITUDINAL STUDIES which are followed over a period of time.Disease Progression: The worsening of a disease over time. This concept is most often used for chronic and incurable diseases where the stage of the disease is an important determinant of therapy and prognosis.Follow-Up Studies: Studies in which individuals or populations are followed to assess the outcome of exposures, procedures, or effects of a characteristic, e.g., occurrence of disease.Tuberculosis: Any of the infectious diseases of man and other animals caused by species of MYCOBACTERIUM.HIV Protease: Enzyme of the human immunodeficiency virus that is required for post-translational cleavage of gag and gag-pol precursor polyproteins into functional products needed for viral assembly. HIV protease is an aspartic protease encoded by the amino terminus of the pol gene.Antitubercular Agents: Drugs used in the treatment of tuberculosis. They are divided into two main classes: "first-line" agents, those with the greatest efficacy and acceptable degrees of toxicity used successfully in the great majority of cases; and "second-line" drugs used in drug-resistant cases or those in which some other patient-related condition has compromised the effectiveness of primary therapy.Virus Replication: The process of intracellular viral multiplication, consisting of the synthesis of PROTEINS; NUCLEIC ACIDS; and sometimes LIPIDS, and their assembly into a new infectious particle.Prevalence: The total number of cases of a given disease in a specified population at a designated time. It is differentiated from INCIDENCE, which refers to the number of new cases in the population at a given time.CD4-CD8 Ratio: Ratio of T-LYMPHOCYTES that express the CD4 ANTIGEN to those that express the CD8 ANTIGEN. This value is commonly assessed in the diagnosis and staging of diseases affecting the IMMUNE SYSTEM including HIV INFECTIONS.AIDS-Associated Nephropathy: Renal syndrome in human immunodeficiency virus-infected patients characterized by nephrotic syndrome, severe proteinuria, focal and segmental glomerulosclerosis with distinctive tubular and interstitial changes, enlarged kidneys, and peculiar tubuloreticular structures. The syndrome is distinct from heroin-associated nephropathy as well as other forms of kidney disease seen in HIV-infected patients.Plasma: The residual portion of BLOOD that is left after removal of BLOOD CELLS by CENTRIFUGATION without prior BLOOD COAGULATION.Incidence: The number of new cases of a given disease during a given period in a specified population. It also is used for the rate at which new events occur in a defined population. It is differentiated from PREVALENCE, which refers to all cases, new or old, in the population at a given time.CD8-Positive T-Lymphocytes: A critical subpopulation of regulatory T-lymphocytes involved in MHC Class I-restricted interactions. They include both cytotoxic T-lymphocytes (T-LYMPHOCYTES, CYTOTOXIC) and CD8+ suppressor T-lymphocytes.Sarcoma, Kaposi: A multicentric, malignant neoplastic vascular proliferation characterized by the development of bluish-red cutaneous nodules, usually on the lower extremities, most often on the toes or feet, and slowly increasing in size and number and spreading to more proximal areas. The tumors have endothelium-lined channels and vascular spaces admixed with variably sized aggregates of spindle-shaped cells, and often remain confined to the skin and subcutaneous tissue, but widespread visceral involvement may occur. Kaposi's sarcoma occurs spontaneously in Jewish and Italian males in Europe and the United States. An aggressive variant in young children is endemic in some areas of Africa. A third form occurs in about 0.04% of kidney transplant patients. There is also a high incidence in AIDS patients. (From Dorland, 27th ed & Holland et al., Cancer Medicine, 3d ed, pp2105-7) HHV-8 is the suspected cause.Developing Countries: Countries in the process of change with economic growth, that is, an increase in production, per capita consumption, and income. The process of economic growth involves better utilization of natural and human resources, which results in a change in the social, political, and economic structures.HIV Long-Term Survivors: Persons who have experienced prolonged survival of HIV infection. This includes the full spectrum of untreated, HIV-infected long-term asymptomatics to those with AIDS who have survived due to successful treatment.Longitudinal Studies: Studies in which variables relating to an individual or group of individuals are assessed over a period of time.Saquinavir: An HIV protease inhibitor which acts as an analog of an HIV protease cleavage site. It is a highly specific inhibitor of HIV-1 and HIV-2 proteases, and also inhibits CYTOCHROME P-450 CYP3A.Antiviral Agents: Agents used in the prophylaxis or therapy of VIRUS DISEASES. Some of the ways they may act include preventing viral replication by inhibiting viral DNA polymerase; binding to specific cell-surface receptors and inhibiting viral penetration or uncoating; inhibiting viral protein synthesis; or blocking late stages of virus assembly.Zimbabwe: A republic in southern Africa, east of ZAMBIA and BOTSWANA and west of MOZAMBIQUE. Its capital is Harare. It was formerly called Rhodesia and Southern Rhodesia.Pregnancy: The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.Lymphocyte Count: The number of LYMPHOCYTES per unit volume of BLOOD.Virus Latency: The ability of a pathogenic virus to lie dormant within a cell (latent infection). In eukaryotes, subsequent activation and viral replication is thought to be caused by extracellular stimulation of cellular transcription factors. Latency in bacteriophage is maintained by the expression of virally encoded repressors.HIV Seronegativity: Immune status consisting of non-production of HIV antibodies, as determined by various serological tests.Acidosis, Lactic: Acidosis caused by accumulation of lactic acid more rapidly than it can be metabolized. It may occur spontaneously or in association with diseases such as DIABETES MELLITUS; LEUKEMIA; or LIVER FAILURE.Cameroon: A republic in central Africa lying east of CHAD and the CENTRAL AFRICAN REPUBLIC and west of NIGERIA. The capital is Yaounde.Treatment Refusal: Patient or client refusal of or resistance to medical, psychological, or psychiatric treatment. (APA, Thesaurus of Psychological Index Terms, 8th ed.)Thailand: Formerly known as Siam, this is a Southeast Asian nation at the center of the Indochina peninsula. Bangkok is the capital city.Withholding Treatment: Withholding or withdrawal of a particular treatment or treatments, often (but not necessarily) life-prolonging treatment, from a patient or from a research subject as part of a research protocol. The concept is differentiated from REFUSAL TO TREAT, where the emphasis is on the health professional's or health facility's refusal to treat a patient or group of patients when the patient or the patient's representative requests treatment. Withholding of life-prolonging treatment is usually indexed only with EUTHANASIA, PASSIVE, unless the distinction between withholding and withdrawing treatment, or the issue of withholding palliative rather than curative treatment, is discussed.Substance Abuse, Intravenous: Abuse, overuse, or misuse of a substance by its injection into a vein.DNA, Viral: Deoxyribonucleic acid that makes up the genetic material of viruses.Haiti: A republic in the Greater Antilles in the West Indies. Its capital is Port-au-Prince. With the Dominican Republic it forms the island of Hispaniola - Haiti occupying the western third and the Dominican Republic, the eastern two thirds. Haiti belonged to France from 1697 until its rule was challenged by slave insurrections from 1791. It became a republic in 1820. It was virtually an American protectorate from 1915 to 1934. It adopted its present constitution in 1964 and amended it in 1971. The name may represent either of two Caribbean words, haiti, mountain land, or jhaiti, nest. (From Webster's New Geographical Dictionary, 1988, p481 & Room, Brewer's Dictionary of Names, 1992, p225)Kenya: A republic in eastern Africa, south of ETHIOPIA, west of SOMALIA with TANZANIA to its south, and coastline on the Indian Ocean. Its capital is Nairobi.Hepatitis C: INFLAMMATION of the LIVER in humans caused by HEPATITIS C VIRUS, a single-stranded RNA virus. Its incubation period is 30-90 days. Hepatitis C is transmitted primarily by contaminated blood parenterally, and is often associated with transfusion and intravenous drug abuse. However, in a significant number of cases, the source of hepatitis C infection is unknown.Multivariate Analysis: A set of techniques used when variation in several variables has to be studied simultaneously. In statistics, multivariate analysis is interpreted as any analytic method that allows simultaneous study of two or more dependent variables.Proportional Hazards Models: Statistical models used in survival analysis that assert that the effect of the study factors on the hazard rate in the study population is multiplicative and does not change over time.CambodiaGenotype: The genetic constitution of the individual, comprising the ALLELES present at each GENETIC LOCUS.pol Gene Products, Human Immunodeficiency Virus: Proteins encoded by the POL GENE of the HUMAN IMMUNODEFICIENCY VIRUS.British Columbia: A province of Canada on the Pacific coast. Its capital is Victoria. The name given in 1858 derives from the Columbia River which was named by the American captain Robert Gray for his ship Columbia which in turn was named for Columbus. (From Webster's New Geographical Dictionary, 1988, p178 & Room, Brewer's Dictionary of Names, 1992, p81-2)Toxoplasmosis, Cerebral: Infections of the BRAIN caused by the protozoan TOXOPLASMA gondii that primarily arise in individuals with IMMUNOLOGIC DEFICIENCY SYNDROMES (see also AIDS-RELATED OPPORTUNISTIC INFECTIONS). The infection may involve the brain diffusely or form discrete abscesses. Clinical manifestations include SEIZURES, altered mentation, headache, focal neurologic deficits, and INTRACRANIAL HYPERTENSION. (From Joynt, Clinical Neurology, 1998, Ch27, pp41-3)Lesotho: A kingdom in southern Africa, within the republic of SOUTH AFRICA. Its capital is Maseru.Survival Analysis: A class of statistical procedures for estimating the survival function (function of time, starting with a population 100% well at a given time and providing the percentage of the population still well at later times). The survival analysis is then used for making inferences about the effects of treatments, prognostic factors, exposures, and other covariates on the function.BrazilDrug Interactions: The action of a drug that may affect the activity, metabolism, or toxicity of another drug.Meningitis, Cryptococcal: Meningeal inflammation produced by CRYPTOCOCCUS NEOFORMANS, an encapsulated yeast that tends to infect individuals with ACQUIRED IMMUNODEFICIENCY SYNDROME and other immunocompromised states. The organism enters the body through the respiratory tract, but symptomatic infections are usually limited to the lungs and nervous system. The organism may also produce parenchymal brain lesions (torulomas). Clinically, the course is subacute and may feature HEADACHE; NAUSEA; PHOTOPHOBIA; focal neurologic deficits; SEIZURES; cranial neuropathies; and HYDROCEPHALUS. (From Adams et al., Principles of Neurology, 6th ed, pp721-2)Health Services Accessibility: The degree to which individuals are inhibited or facilitated in their ability to gain entry to and to receive care and services from the health care system. Factors influencing this ability include geographic, architectural, transportational, and financial considerations, among others.United StatesRwanda: A republic in eastern Africa, south of UGANDA, east of DEMOCRATIC REPUBLIC OF THE CONGO, west of TANZANIA. Its capital is Kigali. It was formerly part of the Belgian trust territory of Ruanda-Urund.Pneumonia, Pneumocystis: A pulmonary disease in humans occurring in immunodeficient or malnourished patients or infants, characterized by DYSPNEA, tachypnea, and HYPOXEMIA. Pneumocystis pneumonia is a frequently seen opportunistic infection in AIDS. It is caused by the fungus PNEUMOCYSTIS JIROVECII. The disease is also found in other MAMMALS where it is caused by related species of Pneumocystis.Chemoprevention: The use of chemical compounds to prevent the development of a specific disease.Pyrrolidinones: A group of compounds that are derivatives of oxo-pyrrolidines. A member of this group is 2-oxo pyrrolidine, which is an intermediate in the manufacture of polyvinylpyrrolidone. (From Merck Index, 11th ed)Protease Inhibitors: Compounds which inhibit or antagonize biosynthesis or actions of proteases (ENDOPEPTIDASES).Leukoencephalopathy, Progressive Multifocal: An opportunistic viral infection of the central nervous system associated with conditions that impair cell-mediated immunity (e.g., ACQUIRED IMMUNODEFICIENCY SYNDROME and other IMMUNOLOGIC DEFICIENCY SYNDROMES; HEMATOLOGIC NEOPLASMS; IMMUNOSUPPRESSION; and COLLAGEN DISEASES). The causative organism is JC Polyomavirus (JC VIRUS) which primarily affects oligodendrocytes, resulting in multiple areas of demyelination. Clinical manifestations include DEMENTIA; ATAXIA; visual disturbances; and other focal neurologic deficits, generally progressing to a vegetative state within 6 months. (From Joynt, Clinical Neurology, 1996, Ch26, pp36-7)Mozambique: A republic in southern Africa, south of TANZANIA, east of ZAMBIA and ZIMBABWE, bordered on the west by the Indian Ocean. Its capital is Maputo. It was formerly called Portuguese East Africa.Logistic Models: Statistical models which describe the relationship between a qualitative dependent variable (that is, one which can take only certain discrete values, such as the presence or absence of a disease) and an independent variable. A common application is in epidemiology for estimating an individual's risk (probability of a disease) as a function of a given risk factor.Mutation: Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.IndiaTrimethoprim-Sulfamethoxazole Combination: This drug combination has proved to be an effective therapeutic agent with broad-spectrum antibacterial activity against both gram-positive and gram-negative organisms. It is effective in the treatment of many infections, including PNEUMOCYSTIS PNEUMONIA in AIDS.Infant, Newborn: An infant during the first month after birth.San FranciscoProviruses: Duplex DNA sequences in eukaryotic chromosomes, corresponding to the genome of a virus, that are transmitted from one cell generation to the next without causing lysis of the host. Proviruses are often associated with neoplastic cell transformation and are key features of retrovirus biology.Leukocytes, Mononuclear: Mature LYMPHOCYTES and MONOCYTES transported by the blood to the body's extravascular space. They are morphologically distinguishable from mature granulocytic leukocytes by their large, non-lobed nuclei and lack of coarse, heavily stained cytoplasmic granules.Tanzania: A republic in eastern Africa, south of UGANDA and north of MOZAMBIQUE. Its capital is Dar es Salaam. It was formed in 1964 by a merger of the countries of TANGANYIKA and ZANZIBAR.AfricaHealth Resources: Available manpower, facilities, revenue, equipment, and supplies to produce requisite health care and services.Virus Shedding: The expelling of virus particles from the body. Important routes include the respiratory tract, genital tract, and intestinal tract. Virus shedding is an important means of vertical transmission (INFECTIOUS DISEASE TRANSMISSION, VERTICAL).Genes, pol: DNA sequences that form the coding region for retroviral enzymes including reverse transcriptase, protease, and endonuclease/integrase. "pol" is short for polymerase, the enzyme class of reverse transcriptase.Biological Markers: Measurable and quantifiable biological parameters (e.g., specific enzyme concentration, specific hormone concentration, specific gene phenotype distribution in a population, presence of biological substances) which serve as indices for health- and physiology-related assessments, such as disease risk, psychiatric disorders, environmental exposure and its effects, disease diagnosis, metabolic processes, substance abuse, pregnancy, cell line development, epidemiologic studies, etc.Simian Acquired Immunodeficiency Syndrome: Acquired defect of cellular immunity that occurs naturally in macaques infected with SRV serotypes, experimentally in monkeys inoculated with SRV or MASON-PFIZER MONKEY VIRUS; (MPMV), or in monkeys infected with SIMIAN IMMUNODEFICIENCY VIRUS.Kaplan-Meier Estimate: A nonparametric method of compiling LIFE TABLES or survival tables. It combines calculated probabilities of survival and estimates to allow for observations occurring beyond a measurement threshold, which are assumed to occur randomly. Time intervals are defined as ending each time an event occurs and are therefore unequal. (From Last, A Dictionary of Epidemiology, 1995)Pilot Projects: Small-scale tests of methods and procedures to be used on a larger scale if the pilot study demonstrates that these methods and procedures can work.Lymphocyte Activation: Morphologic alteration of small B LYMPHOCYTES or T LYMPHOCYTES in culture into large blast-like cells able to synthesize DNA and RNA and to divide mitotically. It is induced by INTERLEUKINS; MITOGENS such as PHYTOHEMAGGLUTININS, and by specific ANTIGENS. It may also occur in vivo as in GRAFT REJECTION.Viral Tropism: The specificity of a virus for infecting a particular type of cell or tissue.Dyslipidemias: Abnormalities in the serum levels of LIPIDS, including overproduction or deficiency. Abnormal serum lipid profiles may include high total CHOLESTEROL, high TRIGLYCERIDES, low HIGH DENSITY LIPOPROTEIN CHOLESTEROL, and elevated LOW DENSITY LIPOPROTEIN CHOLESTEROL.Ambulatory Care Facilities: Those facilities which administer health services to individuals who do not require hospitalization or institutionalization.Molecular Sequence Data: Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.Receptors, CCR5: CCR receptors with specificity for CHEMOKINE CCL3; CHEMOKINE CCL4; and CHEMOKINE CCL5. They are expressed at high levels in T-LYMPHOCYTES; B-LYMPHOCYTES; MACROPHAGES; MAST CELLS; and NK CELLS. The CCR5 receptor is used by the HUMAN IMMUNODEFICIENCY VIRUS to infect cells.Mycobacterium avium-intracellulare Infection: A nontuberculous infection when occurring in humans. It is characterized by pulmonary disease, lymphadenitis in children, and systemic disease in AIDS patients. Mycobacterium avium-intracellulare infection of birds and swine results in tuberculosis.Socioeconomic Factors: Social and economic factors that characterize the individual or group within the social structure.Homosexuality, Male: Sexual attraction or relationship between males.Anus Neoplasms: Tumors or cancer of the ANAL CANAL.Drugs, Generic: Drugs whose drug name is not protected by a trademark. They may be manufactured by several companies.World Health Organization: A specialized agency of the United Nations designed as a coordinating authority on international health work; its aim is to promote the attainment of the highest possible level of health by all peoples.Case-Control Studies: Studies which start with the identification of persons with a disease of interest and a control (comparison, referent) group without the disease. The relationship of an attribute to the disease is examined by comparing diseased and non-diseased persons with regard to the frequency or levels of the attribute in each group.Rural Population: The inhabitants of rural areas or of small towns classified as rural.Tuberculosis, Pulmonary: MYCOBACTERIUM infections of the lung.Ethiopia: An independent state in eastern Africa. Ethiopia is located in the Horn of Africa and is bordered on the north and northeast by Eritrea, on the east by Djibouti and Somalia, on the south by Kenya, and on the west and southwest by Sudan. Its capital is Addis Ababa.HIV Antibodies: Antibodies reactive with HIV ANTIGENS.Drug Costs: The amount that a health care institution or organization pays for its drugs. It is one component of the final price that is charged to the consumer (FEES, PHARMACEUTICAL or PRESCRIPTION FEES).Cost-Benefit Analysis: A method of comparing the cost of a program with its expected benefits in dollars (or other currency). The benefit-to-cost ratio is a measure of total return expected per unit of money spent. This analysis generally excludes consideration of factors that are not measured ultimately in economic terms. Cost effectiveness compares alternative ways to achieve a specific set of results.HIV Integrase Inhibitors: Inhibitors of HIV INTEGRASE, an enzyme required for integration of viral DNA into cellular DNA.Drug Combinations: Single preparations containing two or more active agents, for the purpose of their concurrent administration as a fixed dose mixture.Life Expectancy: Based on known statistical data, the number of years which any person of a given age may reasonably expected to live.Cyclohexanes: Six-carbon alicyclic hydrocarbons.HIV-2: An HIV species related to HIV-1 but carrying different antigenic components and with differing nucleic acid composition. It shares serologic reactivity and sequence homology with the simian Lentivirus SIMIAN IMMUNODEFICIENCY VIRUS and infects only T4-lymphocytes expressing the CD4 phenotypic marker.HIV Fusion Inhibitors: Inhibitors of the fusion of HIV to host cells, preventing viral entry. This includes compounds that block attachment of HIV ENVELOPE PROTEIN GP120 to CD4 RECEPTORS.Regression Analysis: Procedures for finding the mathematical function which best describes the relationship between a dependent variable and one or more independent variables. In linear regression (see LINEAR MODELS) the relationship is constrained to be a straight line and LEAST-SQUARES ANALYSIS is used to determine the best fit. In logistic regression (see LOGISTIC MODELS) the dependent variable is qualitative rather than continuously variable and LIKELIHOOD FUNCTIONS are used to find the best relationship. In multiple regression, the dependent variable is considered to depend on more than a single independent variable.Sequence Analysis, DNA: A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.HIV Core Protein p24: A major core protein of the human immunodeficiency virus encoded by the HIV gag gene. HIV-seropositive individuals mount a significant immune response to p24 and thus detection of antibodies to p24 is one basis for determining HIV infection by ELISA and Western blot assays. The protein is also being investigated as a potential HIV immunogen in vaccines.Drug-Induced Liver Injury: A spectrum of clinical liver diseases ranging from mild biochemical abnormalities to ACUTE LIVER FAILURE, caused by drugs, drug metabolites, and chemicals from the environment.Drug Users: People who take drugs for a non-therapeutic or non-medical effect. The drugs may be legal or illegal, but their use often results in adverse medical, legal, or social consequences for the users.AIDS Vaccines: Vaccines or candidate vaccines containing inactivated HIV or some of its component antigens and designed to prevent or treat AIDS. Some vaccines containing antigens are recombinantly produced.T-Lymphocyte Subsets: A classification of T-lymphocytes, especially into helper/inducer, suppressor/effector, and cytotoxic subsets, based on structurally or functionally different populations of cells.Sexual Behavior: Sexual activities of humans.Age Factors: Age as a constituent element or influence contributing to the production of a result. It may be applicable to the cause or the effect of a circumstance. It is used with human or animal concepts but should be differentiated from AGING, a physiological process, and TIME FACTORS which refers only to the passage of time.Phylogeny: The relationships of groups of organisms as reflected by their genetic makeup.Epidemics: Sudden outbreaks of a disease in a country or region not previously recognized in that area, or a rapid increase in the number of new cases of a previous existing endemic disease. Epidemics can also refer to outbreaks of disease in animal or plant populations.Simian immunodeficiency virus: Species of the genus LENTIVIRUS, subgenus primate immunodeficiency viruses (IMMUNODEFICIENCY VIRUSES, PRIMATE), that induces acquired immunodeficiency syndrome in monkeys and apes (SAIDS). The genetic organization of SIV is virtually identical to HIV.Clinical Trials as Topic: Works about pre-planned studies of the safety, efficacy, or optimum dosage schedule (if appropriate) of one or more diagnostic, therapeutic, or prophylactic drugs, devices, or techniques selected according to predetermined criteria of eligibility and observed for predefined evidence of favorable and unfavorable effects. This concept includes clinical trials conducted both in the U.S. and in other countries.Epidemiologic Methods: Research techniques that focus on study designs and data gathering methods in human and animal populations.Substance-Related Disorders: Disorders related to substance abuse.Statistics, Nonparametric: A class of statistical methods applicable to a large set of probability distributions used to test for correlation, location, independence, etc. In most nonparametric statistical tests, the original scores or observations are replaced by another variable containing less information. An important class of nonparametric tests employs the ordinal properties of the data. Another class of tests uses information about whether an observation is above or below some fixed value such as the median, and a third class is based on the frequency of the occurrence of runs in the data. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed, p1284; Corsini, Concise Encyclopedia of Psychology, 1987, p764-5)Candidiasis, Oral: Infection of the mucous membranes of the mouth by a fungus of the genus CANDIDA. (Dorland, 27th ed)Mouth DiseasesNigeria: A republic in western Africa, south of NIGER between BENIN and CAMEROON. Its capital is Abuja.Mutation, Missense: A mutation in which a codon is mutated to one directing the incorporation of a different amino acid. This substitution may result in an inactive or unstable product. (From A Dictionary of Genetics, King & Stansfield, 5th ed)Risk-Taking: Undertaking a task involving a challenge for achievement or a desirable goal in which there is a lack of certainty or a fear of failure. It may also include the exhibiting of certain behaviors whose outcomes may present a risk to the individual or to those associated with him or her.Models, Statistical: Statistical formulations or analyses which, when applied to data and found to fit the data, are then used to verify the assumptions and parameters used in the analysis. Examples of statistical models are the linear model, binomial model, polynomial model, two-parameter model, etc.Flow Cytometry: Technique using an instrument system for making, processing, and displaying one or more measurements on individual cells obtained from a cell suspension. Cells are usually stained with one or more fluorescent dyes specific to cell components of interest, e.g., DNA, and fluorescence of each cell is measured as it rapidly transverses the excitation beam (laser or mercury arc lamp). Fluorescence provides a quantitative measure of various biochemical and biophysical properties of the cell, as well as a basis for cell sorting. Other measurable optical parameters include light absorption and light scattering, the latter being applicable to the measurement of cell size, shape, density, granularity, and stain uptake.Lymphoma, Non-Hodgkin: Any of a group of malignant tumors of lymphoid tissue that differ from HODGKIN DISEASE, being more heterogeneous with respect to malignant cell lineage, clinical course, prognosis, and therapy. The only common feature among these tumors is the absence of giant REED-STERNBERG CELLS, a characteristic of Hodgkin's disease.France: A country in western Europe bordered by the Atlantic Ocean, the English Channel, the Mediterranean Sea, and the countries of Belgium, Germany, Italy, Spain, Switzerland, the principalities of Andorra and Monaco, and by the duchy of Luxembourg. Its capital is Paris.Delivery of Health Care: The concept concerned with all aspects of providing and distributing health services to a patient population.Togo: A republic in western Africa, lying between GHANA on its west and BENIN on its east. Its capital is Lome.Social Stigma: A perceived attribute that is deeply discrediting and is considered to be a violation of social norms.Sex Factors: Maleness or femaleness as a constituent element or influence contributing to the production of a result. It may be applicable to the cause or effect of a circumstance. It is used with human or animal concepts but should be differentiated from SEX CHARACTERISTICS, anatomical or physiological manifestations of sex, and from SEX DISTRIBUTION, the number of males and females in given circumstances.Patient Dropouts: Discontinuance of care received by patient(s) due to reasons other than full recovery from the disease.Gene Products, pol: Retroviral proteins coded by the pol gene. They are usually synthesized as a protein precursor (POLYPROTEINS) and later cleaved into final products that include reverse transcriptase, endonuclease/integrase, and viral protease. Sometimes they are synthesized as a gag-pol fusion protein (FUSION PROTEINS, GAG-POL). pol is short for polymerase, the enzyme class of reverse transcriptase.Neopterin: A pteridine derivative present in body fluids; elevated levels result from immune system activation, malignant disease, allograft rejection, and viral infections. (From Stedman, 26th ed) Neopterin also serves as a precursor in the biosynthesis of biopterin.Antigens, CD38: A bifunctional enzyme that catalyzes the synthesis and HYDROLYSIS of CYCLIC ADP-RIBOSE (cADPR) from NAD+ to ADP-RIBOSE. It is a cell surface molecule which is predominantly expressed on LYMPHOID CELLS and MYELOID CELLS.Questionnaires: Predetermined sets of questions used to collect data - clinical data, social status, occupational group, etc. The term is often applied to a self-completed survey instrument.Polymerase Chain Reaction: In vitro method for producing large amounts of specific DNA or RNA fragments of defined length and sequence from small amounts of short oligonucleotide flanking sequences (primers). The essential steps include thermal denaturation of the double-stranded target molecules, annealing of the primers to their complementary sequences, and extension of the annealed primers by enzymatic synthesis with DNA polymerase. The reaction is efficient, specific, and extremely sensitive. Uses for the reaction include disease diagnosis, detection of difficult-to-isolate pathogens, mutation analysis, genetic testing, DNA sequencing, and analyzing evolutionary relationships.Hepatitis B: INFLAMMATION of the LIVER in humans caused by a member of the ORTHOHEPADNAVIRUS genus, HEPATITIS B VIRUS. It is primarily transmitted by parenteral exposure, such as transfusion of contaminated blood or blood products, but can also be transmitted via sexual or intimate personal contact.Asia: The largest of the continents. It was known to the Romans more specifically as what we know today as Asia Minor. The name comes from at least two possible sources: from the Assyrian asu (to rise) or from the Sanskrit usa (dawn), both with reference to its being the land of the rising sun, i.e., eastern as opposed to Europe, to the west. (From Webster's New Geographical Dictionary, 1988, p82 & Room, Brewer's Dictionary of Names, 1992, p34)Prisons: Penal institutions, or places of confinement for war prisoners.