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Query: UMLS:C0019693 (HIV)
 170,526 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The immune deficiency induced by HIV has its origin in the interaction of the outer envelope glycoprotein gp120/gp41 with receptors present on human immunocytes. Virus binding to cells, virus entry and subsequent compartmentalization resulting in productive infection depends on the interaction of gp120/gp41 with CD4 and other accessory molecules. Gp120 and HIV are markedly immunosuppressive of T-cell responses and, in addition, HIV can functionally delete antigen responsiveness of T cells. Abolition of CD4 binding, by denaturation of gp120, allows study of T-cell epitopes in gp120 and shows the denatured molecule is highly immunogenic even in naive subjects (F. Manca, unpublished). The gp120-binding site of CD4 is shared with MHC class II molecules and the reaction of antibodies within this region of CD4 induces conformational changes that may be significant for virus entry into cells or for syncytial formation. The HIV envelope contains sites of sequence homology with monomorphic human MHC class II sites that do not appear to be naturally immunogenic in humans. In addition to the properties of gp120, it is hypothesized that HIV envelope may also represent an 'alloepitope' of class II to the human T-cell repertoire, and is therefore able to induce a chronic allogeneic response not dissimilar to experimentally induced GVHD. These features are of potential importance both for primary vaccination against HIV, and for the long-term treatment of HIV seropositive patients. Induction of effective T-cell responses to gp120 require use of a denatured or otherwise modified product lacking CD4-binding capacity. The potential distortion of the TCR repertoire by the class-II-homologous and CD4-interactive sequences must be assessed.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:AIDS pathogenesis: HIV envelope and its interaction with cell proteins. 187 30

Lymphokine-activated killer (LAK) activity was analyzed in 31 human immune deficiency virus 1 (HIV-1)-infected patients. It was found to be reduced in all groups of patients, being more pronounced in those with acquired immune deficiency syndrome (AIDS) and AIDS-related complex compared to HIV-1-seropositive, asymptomatic individuals. Only high doses of interleukin-2 were able to restore LAK activity comparable to that of normal controls. In addition, HIV-1 gp41 synthetic peptide sequences 735-752 and 846-860 were able to significantly inhibit normal LAK activity at all the effector:target ratios tested. HIV-1-positive serum and the supernatant fluids from cultured peripheral-blood mononuclear cells from HIV-1-infected patients had the same inhibitory effect on normal LAK activity. These data provide evidence that (1) LAK activity appears to be impaired during the course of HIV-1 infection and (2) HIV-1-positive serum and HIV-1 components could exert a profound inhibition of this functional activity.
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PMID:Inhibition of lymphokine-activated killer activity during HIV infection: role of HIV-1 gp41 synthetic peptides. 208 45

Antibodies to human immune deficiency (HIV) virus were studied in 2000 individuals including cases of non-Hodgkin's lymphoma, systemic lupus erythematosus (SLE), leprosy, chronic renal failure on haemodialysis and patients attending STD clinics. A group of blood donors was also screened, ELISA kits provided by Wellcome Diagnostics were used. Results indicate that the ELISA values were far above the cut off figure in all except in a couple where the husband who had stayed in Uganda for several years, and had features of full blown AIDS died 4 months after the diagnosis. The spouse contacted AIDS within a relatively short incubation period and died within 6 months of diagnosis. The North Indian population thus appears to be free of this virus so far. This observation will be an important lead mark in the future epidemiology of HIV infection in India.
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PMID:HIV-I antibodies in health and disease. 209

Clinical factors of possible importance for the greater than two-fold rise in the incidence of Kaposi sarcoma of the elderly in Sweden before the AIDS epidemic were reviewed in 63 regional patients. 5 patients had lymphoproliferative disease before or at the time of Kaposi sarcoma, and 4 patients had been receiving steroids (including 1 with lymphoma) at diagnosis. 2 of these 9 patients plus 2 additional patients had received blood transfusions 1-9 years before diagnosis. None of 17 patients tested was positive for HIV-1, and none had signs of an unexplained progressive immune defect. Of the evaluable cases, 27% had diabetes mellitus and 7% had had previous myocardial infarction. However, only the frequency of congestive heart failure (47%) was significantly greater than that of an ambulatory control group (P = 0.001) in the age group 75-84 years. Exposure to cytomegalovirus (CMV) was not more common in 15 Kaposi sarcoma patients than in an age and sex matched control group. No single factor could account for increased Kaposi sarcoma among the elderly. If the classical form has an infectious aetiology, the tumour could arise after effective transmission of the agent (as by a transfusion), especially combined with some degree of immune deficiency or perhaps congestive failure late in life.
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PMID:Increased incidence of Kaposi sarcoma in Sweden before the AIDS epidemic. 214 57

Infection with the human immunodeficiency virus (HIV) results in a progressive immune deficiency involving many components of the immune system. The major target cells for infection are CD-4 antigen-bearing cells which include predominantly, but not exclusively, the helper T-cell subset and the monocyte/macrophage cell system. Defective cell-mediated immunity occurs in association with hypergammaglobulinemia, which is a common and early feature of HIV infection. Ability to mount specific antibody responses is often impaired and the in vitro B-cell differentiation responses to T-dependent and T-independent stimuli are depressed. Our investigations with HIV envelope proteins suggest that the viral proteins can exert both stimulatory and suppressive influences on B and T lymphocytes. In addition to the opportunistic infections, children with HIV disease frequently develop serious bacterial infections. Among the currently available immunotherapeutic strategies, iv immunoglobulin therapy has received the most attention as a means to provide antibody replacement in children with recurrent bacterial infections. This modality is likely to be most valuable as adjunctive therapy in treatment protocols directed at HIV and its disease complications.
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PMID:Immune defects in pediatric AIDS, their pathogenesis, and role of immunotherapy. 215 3

High rates of immunologic abnormalities in asymptomatic, clinically healthy urban homosexual men have been associated with promiscuous, unprotected receptive rectal intercourse, and related to infection by the human immunodeficiency virus (HIV), Epstein-Barr virus (EBV) and cytomegalovirus (CMV). In cohort studies in Israel, which is still a low risk country for HIV infection and AIDS, about 40% of asymptomatic, clinically healthy male homosexuals consistently showed T cell defects that were not correlated with anal-receptive sexual behavior and were independent of HIV antibody status. Since pre-existing immune impairments in HIV-seronegative individuals have been implicated as a risk factor for seroconversion, we have attempted to investigate more precisely the role of anal-receptive homosexual activity as a risk factor for the acquisition of immune defects. We compared T lymphocyte profiles and mean geometric titers of EBV and CMV in a homogeneous group of 14 transvestite and male anal-receptive homosexual prostitutes with those of 77 HIV-seronegative male homosexuals who were not exclusively anally passive with multiple sex partners. While 44% of the control group showed a decrease of total T cells or their subpopulations as compared with normal heterosexual men (P less than 0.001), T lymphocyte values of the anal-receptive prostitutes were within the normal range. In the prostitutes, serum antibodies to HIV were detected in only 1 individual, to CMV in 12 of 13, and to EBV in all. Despite high mean geometric titers of antibodies to CMV (86.6) and EBV (25.8), frequent anal-receptive intercourse was not sufficient, in itself, to cause immune impairment in this unique group. The results suggest that the problem of cofactors contributing to immune deficiency in male homosexuals should be reexamined in countries with a low incidence for HIV seropositivity and AIDS.
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PMID:Absence of T cell impairments in a unique group of anal-receptive transvestite and male prostitutes in Israel. 215 85

The production and characterization of Jurkat cell lines that constitutively express functional human immune deficiency virus type 1 (HIV-1) tat protein, using a BK virus plasmid expression vector and HIV-1 tat cDNA, is described. An increased growth rate of these Jurkat-tat cell lines as compared with control cell lines was observed.
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PMID:Constitutive expression of HIV-1 tat protein in human Jurkat T cells using a BK virus vector. 215 43

A total of 166 consecutive clinical episodes of pneumonitis in patients with acquired immune deficiency syndrome (AIDS) or antibody positive for human immune deficiency virus (HIV) were investigated for evidence of cytomegalovirus (CMV) infection in their lungs and at peripheral sites to determine the pathogenicity of this virus in the lung and its relationship to peripheral CMV shedding. Evidence of CMV infection was sought in bronchoalveolar lavage (BAL) fluid, blood, saliva, and urine using a specific monoclonal antibody to antigens produced by CMV-infected cells within 24 h. Although CMV was detected in 31 (19%) of BAL fluid specimens, in only six episodes was this the sole pathologic finding. In the remaining episodes either another infectious agent, Kaposi's sarcoma, or lymphoid interstitial pneumonitis was found or no pathogen was detected. None of the patients were given specific anti-CMV treatment, and all but two recovered, including those patients in whom CMV was the sole finding at BAL. The presence of peripheral shedding of CMV did not have any significance in mortality or morbidity. Our findings are in direct contrast to those in recipients of allogeneic bone marrow transplants, in whom CMV pneumonitis is associated with a high mortality. We postulate that this difference is because AIDS patients cannot mount the destructive immune response to CMV in the lung, which we believe to be the basis of the pathology seen in the former group. We conclude that CMV is not a pathogen in the lungs of patients with HIV infection, and we suggest that its presence at this site does not warrant specific therapy in these patients.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Cytomegalovirus in the lungs of patients with AIDS. Respiratory pathogen or passenger? 216 29

The lesions observed in biopsy and autopsy material from children with the acquired immunodeficiency syndrome (AIDS) can be divided into three pathogenetic categories: primary lesions related to infection by human immunodeficiency virus (HIV) (e.g., lymphoreticular system and brain); lesions due to the sequelae of HIV infection (e.g., opportunistic infections, pulmonary lymphoid lesions, etc.); and lesions of undetermined pathogenesis (e.g., renal lesions, cardiomyopathy, etc.). The role of morphologic studies in AIDS in understanding the pathogenesis of the various lesions and their clinical implications are discussed by describing the following examples among others. Study of the thymus enabled us to distinguish AIDS from some congenital immune deficiency syndromes. Thymic injury contributes to immunodeficiency in AIDS. Its apparent irreversibility will have to be considered in the long-term management of children with AIDS when specific effective therapy for HIV becomes available. Demonstration of HIV--like particles in the characteristic giant cells in the brain has been instrumental in the recognition of HIV encephalopathy. Biopsy is helpful in the rapid diagnosis of opportunistic infections (OIs). Autopsy study of OIs has shown involvement of clinically unsuspected organs, such as the adrenals. Characterization of the pulmonary lymphoid lesions led to their inclusion as a diagnostic criterion for AIDS in children. Progression of pulmonary lymphoid lesions to a lymphoproliferative disorder was demonstrated at autopsy. Recognition of lesions such as cardiomyopathy and arteriopathy at autopsy should alert clinicians to suspect these disorders during life.
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PMID:Morphologic findings in children with acquired immune deficiency syndrome: pathogenesis and clinical implications. 217 17

The incidence of HIV infection continues to increase in the United States especially among injection drug users and women. HIV is a retrovirus that infects selected cells in the immune system and under certain conditions replicates and forms new virus capable of infecting other host cells. The infection produces a continuum of conditions ranging from an asymptomatic carrier state through a series of mild or early diseases (ARC) to devastating immune deficiency and organ dysfunction (AIDS). The virus is transmitted via sex, blood, and from mother to fetus. Immune physiology, effects of HIV on the immune system, and tests to demonstrate the presence of the infection are included.
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PMID:Epidemiology and transmission of infection by human immunodeficiency virus. 219 58


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