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

The potential role of substance abuse, especially cocaine and alcohol as co-factor in HIV infection and in the development and expression of AIDS has been suggested, but the possible biological role of substance abuse in the development of AIDS is not known. In order to better understand immune system function in chronic cocaine abuse, we have assessed primary B cell responses to helper T-cell independent (TI) and dependent (TD) antigens in inbred Fisher male rats injected with 1.25-5 mg cocaine/kg body weight for 10 days. The ability of cocaine-exposed animals to mount primary in vivo splenic plaque-forming cell (PFC) and serum antibody responses to the TI antigen, pneumococcal polysaccharide type III (SIII), was elevated several-fold when compared with controls. The degree of elevation of humoral antibody responses seemed to be directly related to the dose of cocaine. Primary in vivo B cell responses to the TD antigen, sheep red blood cells (SRBC), was elevated at lower concentrations of cocaine (1.25-2.5 mg/kg) and was found to be significantly suppressed after chronic exposure to the higher concentration (5.0 mg/kg). The elevated primary splenic immunostimulation to TI (SIII) may be attributed to a combination of loss of T suppressor cell control and direct B cell stimulation. Elevated immune responses to SRBC at lower concentrations were attributed to stimulation of T helper cells as well as loss of T suppressor cells. Immunosuppression to SRBC observed in response to 5.0 mg/kg of cocaine was most probably due to loss of T helper cell subset functions. These findings were further tested by in vitro methods, where splenic lymphocytes from cocaine-exposed animals were examined for their ability to respond to concanavalin A (Con A) in terms of the induction of antigen non-specific suppressor T cells. The addition of Con A-stimulated splenic lymphocytes from cocaine-treated animals did not inhibit the primary antibody responses of SRBC as compared with saline-treated controls, indicating that suppressor T cells malfunction after cocaine exposure. Lymphocyte subpopulation analysis using fluorescein-labelled monoclonal antibodies showed a significant increase in the B cell populations at doses of 1.25-5 mg/kg. A reciprocal change in T cell populations also took place. No significant numerical change in macrophage (NSE+) and T cell subset, T helper and T suppressor was noticed, suggesting that cocaine probably directly effects mature T cell subset functions but does not affect their differentiation.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Functional analysis of lymphocytes subpopulations in experimental cocaine abuse. I. Dose-dependent activation of lymphocyte subsets. 252 33

Oral hairy leukoplakia (HL) is a lesion that occurs predominantly on the tongue in HIV-infected persons. Evidence strongly indicates that HL is related to the presence of Epstein-Barr virus in the epithelial cells. The lesion appears on the lateral border of the tongue as a painless, white plaque varying in size from a few millimeters to extensive lingual involvement. Histopathologically, the characteristic findings are hyperparakeratosis, hyperplasia, and ballooning of prickle cells resembling koilocytosis. HL is now considered a frequent, early, and specific sign of HIV infection and a strong indicator that AIDS will develop in the patient. We report on two cases of HL with marked oral mucosal involvement with extension to the pharyngeal mucosa.
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PMID:Oral hairy leukoplakia with extensive oral mucosal involvement. Report of two cases. 254 59

A number of 2'3'-dideoxynucleosides have been reported to markedly inhibit the in vitro growth of HIV, the causative agent of acquired immunodeficiency syndrome (AIDS). Clinical trials have shown that the continued therapeutic use of these nucleoside derivatives can be associated with adverse side effects. Since these side effects include myelotoxicity, as occurs in many patients treated with zidovudine (AZT; 3'-azido'3-deoxythymidine), and AIDS patients already represent an immunologically compromised population, we examined the immunological effects of three nucleoside inhibitors, including zidovudine, 2'3'-dideoxycytidine, and 2'3'-dideoxyadenosine (DDA) in a mouse model. Additional studies were conducted to further determine and characterize the potential toxic effects associated with these drugs on the hematopoietic system. Of the three dideoxynucleosides examined, only DDA altered immune functions following a 30-day subchronic exposure in mice. This was evidenced by a marked suppression of the antibody plaque-forming cell response and a slight alteration in macrophage function. None of the nucleoside derivatives affected bone marrow function following in vivo exposure, although AZT produced a mild macrocytic anemia in vivo and was myelotoxic when added in vitro to bone marrow cell cultures. In vitro studies indicated that AZT was capable of affecting both proliferating stem cells as well as the stromal cell microenvironment, both of which play a role in hematopoiesis. These data indicate that, although the mice may not develop the identical toxicities associated with nucleoside therapy in humans, certain adverse immunological and hematological effects were readily discerned which could have relevance to humans.
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PMID:A comparison of three nucleoside analogs with anti-retroviral activity on immune and hematopoietic functions in mice: in vitro toxicity to precursor cells and microstromal environment. 255 33

T-lymphocyte helper and suppressor functions were assessed in 61 hemophilia patients. Twenty one patients were HIV-negative (Group 1), 27 were HIV-positive without having AIDS-related complex (ARC)/AIDS (Group 2), and 13 had ARC/AIDS (Group 3). T, CD4-positive, or CD8-positive T lymphocytes were cocultured with B lymphocytes and pokeweed mitogen for 6 days and immunoglobulin producing cells were assessed in a reverse hemolytic plaque assay. In HIV-infected patients, T cells as well as the CD4-positive T cell subset exhibited reduced helper (P less than .01, Group 2; P less than .0005, Group 3) and elevated suppressor activity (P less than .02, Group 2; P less than .005, Group 3), whereas no significant difference was found between HIV-negative patients and controls. The number of CD4-positive cells was not correlated with CD4 cell function. CD4-positive cells showed no helper activity (less than 10% of control T cells) in 8/11 (73%), but an excessive suppressor activity (greater than 80% suppression of plaque formation) in 6/11 (55%) Group 3 patients. Our results show that defective helper and elevated suppressor functions of T cells in HIV-infected patients are caused not only by a change in the CD4/CD8 cell counts but also by functional abnormalities of the CD4-positive T-cell subset. These abnormal helper and suppressor functions may play a role in the development of the immunodeficiency state of AIDS patients.
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PMID:Helper and suppressor T-cell function in HIV-infected hemophilia patients. 256 59

Genital Kaposi's sarcoma (KS) before the AIDS epidemic was rarely seen in Uganda although a case was seen in 1973, 1982, 1983 and 1985. Eight cases were seen in 1986 and another 17 cases have been documented since the beginning of 1987. Of the 29 patients, 23 were males, 6 females (M:F = 3.8:1); median age 29 years (range 7-70 years). All except 8 males were under 40 years. Six patients had pure nodular disease, while the rest had mixed clinical type. The external genitalia was involved in nodular disease in 15 patients, 12 had infiltrative disease and 6 had ulcerative disease. Florid and plaque were seen in one case each. Mixed cellularity was typed in 13 patients. 19(70.4%) were positive for HIV serology (ELISA Wellcome kit) of whom 13(61.9%) were males. All females were positive. The patient who presented in 1973 remains alive and disease free 13.5 years making it unlikely that he had AIDS. It appears therefore that genital KS is a feature of HIV associated KS and this mode of presentation is new in Uganda.
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PMID:Diagnostic implications of genital Kaposi's sarcoma. 260 33

More than 10(4) plaque-forming units (pfu)/ml of HIV are inactivated during the alcohol fractionation step from plasma to fraction (Fr)-II+III, greater than 10(4) pfu/ml is inactivated from Fr-II+III to Fr-II and greater than 10(4) pfu/ml is inactivated during the polyethylene glycol (PEG) fractionation process from Fr-II+III to intravenous IgG (IVIG). The total inactivation rate from plasma to IVIG via Fr-II+III or Fr-II was calculated to be greater than 10(8) or 10(12), respectively. The PEG fractionation method produces an intact and unmodified IVIG. In addition, the PEG fractionation method at a low ionic strength was found to be effective for the elimination of greater than 10(5) units of other viruses, including hepatitis B, vesicular stomatitis and Sindbis viruses.
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PMID:Elimination of viruses (human immunodeficiency, hepatitis B, vesicular stomatitis and Sindbis viruses) from an intravenous immunoglobulin preparation. 282 31

It is generally accepted that human immunodeficiency virus (HIV) is the etiologic agent of the acquired immunodeficiency syndrome and related diseases. In this report, we demonstrate the antiviral effect of nucleoside analogs 2',3'-didehydro-2',3'-dideoxythymidine (DHT) and 2',3'-didehydro-2',3'-dideoxycytidine (DHC) by using human T-cell lymphotropic virus type I-carrying MT-4 cells, which are extremely susceptible to HIV infection. These agents efficiently inhibited the cytopathic effects and expression of HIV-specific antigens in MT-4 cells after infection of the virus. Both DHT and DHC also strongly blocked viral replication as determined by our quantitative bioassay system using a plaque-forming assay. These antiviral effects were obtained at concentrations at which the drugs produced little or no toxicity and were comparable to those with 3'-azido-3'-deoxythymidine and 2',3'-dideoxynucleosides. These findings warrant further investigation of the use of DHT and DHC for the treatment of the acquired immunodeficiency syndrome and related diseases.
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PMID:Inhibitory effect of 2',3'-didehydro-2',3'-dideoxynucleosides on infectivity, cytopathic effects, and replication of human immunodeficiency virus. 303 11

Thirty residents of north-central Tanzania with various forms of Kaposi's sarcoma (KS) were evaluated. The absolute number of peripheral blood OKT4 lymphocytes in patients and Tanzanian control subjects tended to be low (in comparison with healthy young American adults), and many had inverted T4/T8 ratios. Plasma polyclonal beta- and gamma-globulin concentrations were increased in many patients with KS and in control patients in Tanzania with chronic dermatopathies, but not in African hospital employees and patients undergoing elective surgery. Three of nine patients with locally aggressive KS possessed antibodies to human T-cell lymphotropic virus type III/lyphadenopathy-associated virus (HIV), but none had evidence of the acquired immunodeficiency syndrome (AIDS) or the AIDS-related complex. Three patients with disseminated, rapidly progressive KS and high HIV-antibody titers had an immunologic and clinical picture consistent with AIDS. Two of 13 patients with the classic plaque/nodular form of KS had low plasma titers of HIV antibody, but the significance of these serologic findings is not known. The evidence suggests that HIV plays a role in the pathogenesis of some cases of KS in East Africa, but most patients with KS in East Africa have no evidence of overt immunologic deficiency or HIV infection.
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PMID:Pathogenetic role of HIV infection in Kaposi's sarcoma of equatorial East Africa. 325 65

The effect of weak bases (NH4Cl and amantadine) and carboxylic ionophores (monensin) on the infection of CD4 (T4) positive human cell lines by HIV-1 is examined. These reagents, which raise the pH of acidic intracellular organelles, fail to inhibit HIV-1 entry and the events leading to viral protein synthesis at concentrations inhibitory for low pH-dependent fusogenic enveloped viruses. The infectivity of VSV (HIV-1) pseudotypes is unaffected by weak bases at concentrations causing 95% plaque reduction of VSV in its own envelope. HIV-1 dependent cell--cell fusion (syncytium formation) occurs in medium maintained at pH 7.4-7.6, and virions are not irreversibly inactivated by incubation in acid medium. Our results show that HIV-1 entry and membrane fusion do not require exposure to low pH. The production of infectious HIV-1 particles, however, is inhibited in cells treated with NH4Cl.
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PMID:Human immunodeficiency virus infection of CD4-bearing cells occurs by a pH-independent mechanism. 325 78

Glycyrrhizin (GL), one of the plant extracts, was investigated for its antiviral action on the human immunodeficiency virus [HIV (HTLV-III/LAV)] in vitro, using cytopathic effect and plaque forming assay system in MT-4 cells (a HTLV-I-carrying cell line). Cloned Molt-4 cells (clone No. 8), which are sensitive to HIV and fuse to giant cells after infection, were also used as a parameter for cytopathic effect of HIV. GL completely inhibited HIV-induced plaque formation in MT-4 cells at a concentration of 0.6 mM, the 50% inhibitory dose being 0.15 mM. GL completely inhibited the cytopathic effect of HIV and the HIV-specific antigen expression in MT-4 cells at a concentration of 0.3 and 0.6 mM, respectively. Furthermore, GL inhibited giant cell formation of HIV-infected Molt-4 clone No. 8 cells. GL had no direct effect on the reverse transcriptase of HIV. Its mechanism of anti-HIV action remains to be elucidated.
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PMID:Inhibitory effect of glycyrrhizin on the in vitro infectivity and cytopathic activity of the human immunodeficiency virus [HIV (HTLV-III/LAV)]. 347 37


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