Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0019693 (HIV)
 170,526 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Substance P (sP) and Somatostatin (SOM), so as other neuropeptides can modulate neurologic and immunologic functions. sP has been described to enhance both in vitro and in vivo immunoglobulin synthesis. On the contrary, SOM has an inhibitory effect on the same activity. The modulating effect is more evident on IgA isotype. Hypergammaglobulinemia and in particular high levels of IgA is a common finding in pediatric AIDS and an imbalance among regulatory effects of neuropeptides might be suggested. In order to evaluate the plasma levels of sP in pediatric AIDS we studied 15 children with HIV infection (status P2), 10 seronegative children born to HIV positive mothers and 10 healthy children of the same age. All the HIV positive children had high plasma levels of IgG and IgA. The plasma level of sP was extremely higher in HIV positive children while no significant difference was found between seronegative children born to HIV positive mothers and healthy children. SOM was decreased in HIV positive children when compared to control groups but a significant difference was not reached. It might be supposed that HIV infection, through a dysregulation among neuropeptides interferes on immune functions and in particular on IgA synthesis. On the other hand it might be suggested that the imbalance between sP and SOM depends on the viral infection of immune cells since it has been demonstrated that SOM and other neuropeptide are synthesized by lymphoid tissue. Further studied relevance of neuropeptide disorders in pediatric AIDS.
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PMID:[Changed levels of substance P and somatostatin in HIV-positive children]. 128 55

We have previously demonstrated that acidic medium inhibits the replication of HIV-1. The present study was designed to examine the effects of other growth conditions and infection of fibroblasts by coculture with HIV infected lymphoid cells. Several lymphoblastoid cell lines normally grown in RPMI-1640 were grown in Eagle's MEM. These cells supported virus replication to higher titres than did RPMI-1640. Peak viral titres were achieved within 24-48 h after newly infected or chronically infected cells were placed in fresh medium. When virus was stored in liquid medium either frozen or at higher temperatures, virus titres were retained for several months while frozen but decreased upon storage at 4 degrees C or higher. If cells were passaged after trypsinization in Ca(++)-depleted medium, then a decreased susceptibility of cells for HIV-1 by 2 log10 at 24 h post infection was observed. Infectivity of cell-free and cell-associated HIV-1 was measured using syncytium formation, reverse transcriptase activity and p24 antigen. No fusion between HIV-1 infected CD4+ lymphoblasts and CD4- fibroblasts was observed but HIV-1 infected lymphoid cells, even in the absence of syncytium formation, exerted a strong toxic effect on fibroblasts. This study extends previous findings that medium acidity was inhibitory to virus replication and survival. Thus, conditions for study of HIV must be well controlled in buffered medium so that misleading results are not obtained regarding virus multiplication and possibly regarding transmission to and pathogenesis in CD4- cells.
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PMID:The influence of cell culture and storage conditions on HIV-1 infectivity and fusogenic activity. 128 37

There is an increasingly body of evidence, obtained both in vitro and in vivo, showing that exogenous opioids have a variety of effects on cells of the immune system. The consequence is that opiates at pharmacological concentrations suppress cell-mediated immunity, as reflected by depressed T-dependent antibody production by B lymphocytes, altered T lymphocyte functions such as proliferation, delayed-type hypersensitivity, graft-versus-host responses and decreased cytotoxic NK cell activity. The macrophage/monocyte oxidative burst and phagocytosis are also impaired, effects probably mediated by various opioid receptor types as they are blocked or reversed by naloxone, an opioid antagonist. Other possible mechanisms of interaction remain to be elucidated: exogenous opioids can act on neurons of the central nervous system, thereby activating the neuroendocrine system with a subsequent increase in serum glucocorticoid levels. Another potential link between the central nervous system and lymphoid tissue is the sympathetic nervous system, via which opioid-induced activation could result in noradrenergic inhibition of the immune system. The clinical consequences of these suppressive effects on the immune system are seen in the striking increase in the incidence of infections in intravenous opioid addicts. The advent of AIDS and the identification of intravenous drug abusers as a critical risk group have propelled interest in this area. Data obtained both in vitro and in vivo with various experimental models shows that morphine increases susceptibility to bacterial and viral infections, the latter effect possibly being related to a depressive effect of opioids on gamma-interferon levels. The dosage and time of administration strongly influence the results: it appears that chronic opioid treatment in vivo induces a state of immune tolerance, with normal resistance to viral infections, whereas short or single administration has a detrimental effect. In the former context, other factors such as a morphine-induced increase in CD4+ cell numbers may tend to enhance the infectivity of HIV-infected subjects.
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PMID:Opiates and immune function. Consequences on infectious diseases with special reference to AIDS. 130 43

Follicular dendritic cells (FDC) are involved in the trapping and retention of antigen-antibody complexes in lymphoid follicles. This FDC immobilized antigen is thought to be involved in the generation of memory B-lymphocytes. Follicular trapping of both Aleutian disease virus and HIV particles has been demonstrated. However as far as known their affects on FDC and follicular B-cells are completely different. It is hypothesized that the trapping of (antibody-complexed) virus particles by the FDC-network may have an important role in several virus diseases.
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PMID:Follicular dendritic cell-B cell interactions in virus disease. Common localization but different cell damage caused by antibody immobilized virus? 130 42

Murine acquired immunodeficiency syndrome (MAIDS) develops when C57B1/6 mice are inoculated with LP-BM5 murine leukemia viruses. Disease progression in these animals is characterized by lymphadenopathy, polyclonal B-cell activation, severe immunodeficiency, and death. Mice with MAIDS have been used to examine the efficacy of antiretroviral therapies for possible use in AIDS patients. In the present work, MAIDS mice were employed to test the hypothesis that established retroviral infection might be cured by the combined use of a cytotoxic agent (cyclophosphamide) and total body irradiation--a regimen reported to have successfully cured HIV-1 infection in one AIDS patient. Results indicate that the ablation of retrovirus-infected lymphoid cells reduced but did not eliminate LP-BM5 infection. Moreover, this regimen was no more effective at controlling virus proliferation or preventing the polyclonal IgG activation characteristic of murine AIDS than was AZT alone.
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PMID:Effect of cyclophosphamide, total body irradiation, and zidovudine on retrovirus proliferation and disease progression in murine AIDS. 131 Jun 3

Persistent generalized lymphadenopathy (PGL) and polyclonal B cell activation are features of infection with HIV. Epstein-Barr virus (EBV) and HIV are known to activate B cells in vitro, but whether they are important B cell activators in patients infected with HIV is less clear. In this study, lymph node tissue was obtained from 10 patients with PGL and assessed for evidence of EBV and HIV gene sequences. DNA was extracted and specific viral gene sequences identified using the polymerase chain reaction (PCR). EBV sequences were difficult to detect in the PGL tissue, with a signal intensity similar to that of other benign and malignant lymphoid conditions not associated with EBV. HIV sequences were also rare in the PGL tissue, consistent with HIV infection of the small number of peripheral blood cells and nodal T cells likely to be present in such a sample. These findings suggest that the polyclonal B cell activation typical of HIV is not driven by direct EBV or HIV infection of B cells.
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PMID:Epstein-Barr virus and HIV play no direct role in persistent generalized lymphadenopathy syndrome. 131 93

Human immunodeficiency virus type 1 (HIV-1) prototype, HIV1 LAV, and a Zairian virus HIV1 NDK, an isolate highly cytopathic for CD4+ lymphocytes, were used to infect eleven different CD4 negative non-lymphoid human cell lines. Eight of the lines were derived from carcinomas wherein human papillomavirus was thought to have been etiologic. All these cell lines lacked CD4 receptor and CD4 specific mRNA. After cocultivation with sensitive CEM cells, HIV-1 LAV was rescued from six infected cell lines and HIV-1 NDK from nine. Shedding of free virus into the culture medium was observed in three cell lines infected by HIV-1 NDK and in only one cell line infected by HIV-1 LAV. The infectibility of CD4 negative cell lines indicates that both HIV-1 strains were able to use a CD4 independent mechanism to infect the cells; however, HIV-1 NDK showed the higher efficiency of infection. This virus was also able to overcome the intracellular block of viral reproduction. These results suggest that a broader spectrum of cell types of non-lymphoid origin lacking the CD4 receptor can serve as a viral reservoir. In some cases they are direct producers of infectious HIV-1 particles. This suggests, that in addition to immunosuppressive mechanisms, HIV-1 could play a more direct role in induction of neoplastic changes.
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PMID:HIV-1 infectivity of human carcinoma cell lines lacking CD4 receptors. 131 32

Herein we have provided a panorama of the clinical, histopathologic, and molecular biologic mechanisms of EBV-induced LPD particularly in immunosuppressed individuals. A listing of EBV-related diseases is shown in Table 4. We have stressed the frequent need to use multiple diagnostic methods for detecting EBV genome, particularly in immunodeficient patients who may fail to mount antibody responses to EBV. Given that we now recognize some of the immunocompromised patient populations at high risk for EBV-induced LPD, and have developed techniques for detecting EBV genome and early LPD, we may eventually prevent the occurrence of some of these life-threatening diseases. For example, we have learned to recognize and distinguish hepatic allograft rejection from EBV-induced LPD in hepatic biopsies (154). A periportal and sinusoidal infiltrate of small and large lymphoid cells, immunoblasts, and plasma cells, alert us to stain frozen liver sections for EBNA. Finding EBV guides the clinicians to reducing immunosuppression which then allows the restoration of immunosurveillance against the EBV-infected B cells. Whether an EBV vaccine can be successful in immunosuppressed individuals remains to be seen. As for other vaccines, many logistical problems prevail, such as the early occurrence of EBV infection during infancy in regions where BL is endemic. Surely, with the menacing threat that approximately 10% of patients with AIDS will develop NHL, new anti-viral therapy against EBV and the causative agent of AIDS and HIV, will be developed. The pathologist and virologist play essential roles in the recognition of EBV infection by performing clinical laboratory determinations. The characteristic histopathologic features of EBV-induced LPD are now recognized and when confirmed with molecular hybridization and immunofluorescent techniques will provide a solid diagnostic approach and, thus, a foundation for developing a sound therapeutic strategy.
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PMID:Epstein-Barr virus-associated lymphoproliferative disorders. 132 Jul 11

Tissue samples of 21 HIV-positive patients have been studied for the presence and distribution of Epstein-Barr virus (EBV) subtypes A and B. This was done by PCR, EBER in situ hybridization, and immunohistochemical detection of EBV latent membrane protein (LMP) in AIDS-associated malignant lymphomas (16 cases) and lymphatic organs of patients without lymphoma (5 cases). Eleven cases were considered to be EBV-positive, with type A in four, and type B virus in four other cases. In patients with malignant lymphoma, EBV was localized in tumour tissue exclusively. One patient without lymphoma presented with multiple EBV genome type B-positive cells in all the lymphoid tissue samples examined. In HIV-positive patients, both subtypes of EBV, A and B, may play a role in the pathogenesis of lymphoproliferative lesions.
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PMID:Distribution and localization of Epstein-Barr virus subtypes A and B in AIDS-related lymphomas and lymphatic tissue of HIV-positive patients. 133 41

The biochemical mechanisms underlying blood lymphoid cell genome destabilization in patients with HIV infection have been analyzed. Lymphocytes from HIV patients are characterized by increasing intensity of free radical oxidation together with activation of the xanthine oxidase D-form conversion into the O-form, enhanced activity of UV-endonuclease, and intensification of prooxidant-induced proteolysis. These changes increasing with the progress of the disease with a maximum at the AIDS stage form a metabolic basis for labilization of the lymph cell genome. The degree of biochemical manifestations of genome instability (levels of chromatin degradation products and intensity of formation of one-filament nicks of DNA) increase in the dynamics of HIV-infection. The data obtained are discussed in terms of the author's conception on the origin of AIDS from retroposons (retrotransposons?). A hypothesis is postulated on accumulation of autonomous genetic information on the basis of genome labilization under the influence of genotoxic factors. Clinico-biochemical data on the appearance of HIV proteins (p17, p24) in the blood of patients (previously negative for all HIV markers) in the presence of transfusions of HIV-negative blood and UV-irradiation of the autoblood are also discussed from this standpoint.
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PMID:[Genomic instability and AIDS]. 133 9


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