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

The rates of mother-to-child transmission of human immunodeficiency virus type 1 (HIV-1), progression to AIDS following HIV-1 infection, and AIDS-associated mortality are all inversely correlated with serum vitamin A levels (R. D. Semba, W. T. Caiaffa, N. M. H. Graham, S. Cohn, and D. Vlahov, J. Infect. Dis. 171:1196-1202, 1995; R. D. Semba, N. M. H. Graham, W. T. Caiaffa, J. B. Margolik, L. Clement, and D. Vlahov, Arch. Intern. Med. 153:2149-2154, 1993; R. D. Semba, P. G. Miotti, J. D. Chiphangwi, A. J. Saah, J. K. Canner, G. A. Dallabetta, and D. R. Hoover, Lancet 343:1593-1596, 1994). Here we show that physiological concentrations of vitamin A, as retinol or as its metabolite, all-trans retinoic acid, repressed HIV-1Ba-L replication in monocyte-derived macrophages (MDMs). Repression required retinoid treatment of peripheral monocytes during their in vitro differentiation into MDMs. Retinoids had no repressive effect if they were added after virus infection. Retinol, as well as all-trans retinoic acid and 9-cis retinoic acid, also repressed HIV-1 long terminal repeat (LTR)-directed expression up to 200-fold in transfected THP-1 monocytes. Analysis of HIV-1 LTR deletion mutants demonstrated that retinoids were able to repress activation of HIV-1 expression by both NF-kappaB and Tat. A cis-acting sequence required for retinoid-mediated repression of HIV-1 transcription was localized between nucleotides -51 and +12 of the HIV-1 LTR within the core promoter. Protein-DNA cross-linking experiments identified four proteins specific to retinoid-treated cells that bound to the core promoter. We conclude that retinoids render macrophages resistant to virus replication by modulating the interaction of cellular transcription factors with the viral core promoter.
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PMID:Retinoid-induced repression of human immunodeficiency virus type 1 core promoter activity inhibits virus replication. 962 Oct 47

Kaposi's sarcoma (KS) is a highly angiogenic lesion which frequently presents as an aggressive form in HIV-infected male patients. We have previously shown that the HIV-1 Tat protein induces endothelial cell migration and invasion in vitro and a rapid angiogenic response in vivo, suggesting that it acts as a cofactor in epidemic KS. In this study we tested beta interferon (IFN beta) and retinoic acid (RA) for the inhibition of Tat-induced angiogenesis using in vivo and in vitro models. IFN beta, at a concentration above 2500 U/ml, was an effective inhibitor of Tat-stimulated growth, migration and morphogenesis of an endothelial cell line in vitro and of angiogenesis in vivo. A strong reduction of properties associated with neovascularisation was induced by 10,000 U/ml. In vivo, RA alone was on ineffective inhibitor of angiogenesis, and in vitro gave only a limited inhibition of endothelial cell growth. However, 13-cis RA used in combination with IFN beta impressively potentiated its effects. A combination of lower doses of IFN beta (2500 U/ml) and 13-cis RA induced a virtually complete inhibition of the Tat-related angiogenic phenotype both in vivo and in vitro. The potentiation of the anti-angiogenic activity of IFN beta by 13-cis RA suggests that this combination could be a useful approach for the therapy of epidemic KS.
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PMID:beta Interferon inhibits HIV-1 Tat-induced angiogenesis: synergism with 13-cis retinoic acid. 971 11

The past several years have seen demonstrable progress in the therapy of Kaposi's sarcoma (KS). Liposomal anthracyclines and paclitaxel have been found to be highly effective chemotherapeutic agents for this disease. Recent advances in our understanding of the pathogenesis of KS have led to the consideration of various new experimental agents. Two antiangiogenesis agents, TNP-470 and thalidomide, have been determined to induce some responses in KS, and others are now in early clinical trials or in preclinical development. Oral 9-cis retinoic acid has been shown to have anti-KS activity, and preliminary studies suggest that a urinary protein found in preparations of human chorionic gonadotropin also has activity. Effective anti-HIV treatment has been shown to affect the growth of KS, and the discovery of a new herpesvirus as a causative agent for KS has offered new potential targets for attack.
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PMID:Therapy for Kaposi's sarcoma: recent advances and experimental approaches. 1043 Feb 21

Over the last 20 years of experience with the AIDS epidemic, we have accumulated a great body of knowledge on Kaposi's sarcoma (KS), a major cause of morbidity and mortality in AIDS patients, especially among homosexual and bisexual men. New antiretroviral therapies, in particular the protease inhibitors, appear to be changing the clinical course of KS. Now, it is not unusual to observe a complete resolution and control of KS with the use of these new agents. As we have begun to unravel the pathogenesis of KS, new treatment modalities have merged targeting some of its pathogenic pathways. Although, chemotherapy remains the cornerstone of its treatment, in particular with the new liposomal preparations, new agents may soon change our approach to KS. Experimental therapies being evaluated in ongoing clinical trials include angiogenesis inhibitors, hormonal therapies, retinoic acid derivatives, and immune modulators such as interleukin 12. Better treatment for HIV, and new experimental therapies targeting the pathogenic mechanisms of KS allow us to envision the future treatment of KS with a certain degree of optimism.
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PMID:Kaposi's sarcoma. New treatment modalities. 1062 22

Studies have demonstrated that human immunodeficiency virus type 1 (HIV-1) infection of central nervous system (CNS)-based cells in vivo results in a series of devastating clinical conditions collectively termed acquired immune deficiency syndrome (AIDS) dementia complex (ADC). Gene therapy for these neurovirological disorders necessitates utilization of a vector system that can mediate in vivo delivery and long-term expression of an antiretroviral transgene in nondividing/postmitotic CNS cellular elements. The present studies focus on the transfer of an anti-HIV-1 gene to primary isolated CNS microvascular endothelial cells (MVECs) and neuronal-based cells, for its effects in protecting these cells from HIV-1 infection. By using an HIV-1-based vector system, it was possible to efficiently transduce and maintain expression of a marker transgene, beta-galactosidase (beta-Gal), in human CNS MVECs, human fetal astrocytes, plus immature and mature (differentiated) NT2 cells. Significant transduction of the marker gene, beta-Gal, in CNS-based cells prompted the utilization of this system with an anti-HIV-1 gene therapeutic construct, RevM10, a trans-dominant negative mutant Rev protein. Initially, it was not possible to generate any HIV-1 vector particles with the RevM10 gene in the transducing construct, because of inhibitory effects on the HIV-1 vector by this gene product. However, the vector could be partially rescued by adding an additional construct that supplied wild-type rev, in trans, during a multiple construct transfection in the packaging 293T cells. Thus, it was possible to significantly improve the titer of RevM10-expressing viral particles generated from these cells. Moreover, this RevM10 vector transduced the neuronal precursor cell line NT2, retinoic acid-differentiated human neurons (hNT) from the precursor cells, and primary isolated human brain MVECs with high efficiency. RevM10 generated from the HIV-1-based vector system potently inhibited replication of diverse HIV-1 strains in human CNS MVECs and neuronal cells. The data generated from these studies represent an initial approach for future development of anti-HIV-1 gene therapy in the CNS.
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PMID:Anti-human immunodeficiency virus type 1 gene therapy in human central nervous system-based cells: an initial approach against a potential viral reservoir. 1068 Aug 47

HIV protease inhibitors (PIs) are effective drugs for the treatment of AIDS. However, PI therapy is sometimes associated with side-effects including increased plasma lipids and altered body fat distribution, although fat redistribution may occur in some patients not treated with PIs. Overdosage with vitamin A(1) acid (all-trans-retinoic acid, ATRA) or its metabolites may cause similar changes in lipid metabolism. Moreover, the PI indinavir and retinoids have been associated with nail, skin, and hair defects, suggesting that indinavir and retinoids may exert their effects through similar molecular mechanisms. This hypothesis was tested by examining the effects of PIs on retinoid signaling in vitro. Mesenchymal stem cells (C3H10T1/2) were cultured in the presence of various PIs (amprenavir, indinavir, nelfinavir, ritonavir, and saquinavir) and synthetic retinoids, and the metabolic response was assessed by measuring the activity of a retinoid-regulated protein, alkaline phosphatase (ALP). Of the PIs tested, only indinavir stimulated ATRA-dependent ALP activity and altered stem cell morphology; the effects of indinavir occurred in the presence of ATRA, but not in its absence. Moreover, indinavir increased the effects of ATRA on lipid accumulation during fat cell differentiation. AGN 193109 (4-[[5,6-dihydro-5, 5-dimethyl-8-(4-methylphenyl)-2-naphthalenyl]ethynyl]-benzoic acid), a retinoic acid receptor (RAR) antagonist, inhibited the synergistic effects of indinavir and ATRA, indicating that indinavir increases RAR signaling. However, indinavir did not potentiate ALP activity in the presence of the RAR agonist CH55 (3,5-di-tert-butylchalcone 4'-carboxylic acid). Unlike ATRA, CH55 does not bind to cytosolic retinoic acid binding protein (CRABP), suggesting that CRABP may regulate the effects of indinavir on RAR signaling. These observations support the proposal that altered retinoid signaling promotes some of the adverse reactions associated with indinavir therapy, such as altered lipid metabolism.
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PMID:Stimulation of vitamin A(1) acid signaling by the HIV protease inhibitor indinavir. 1070 35

Most of the functions of vitamin A are mediated through the binding of retinoic acid to specific nuclear receptors that regulate genomic expression. Recent experimental work in transgenic mice showed clearly that normal embryonic development depends on the correct spatial and temporal expression of the receptors in the differentiating cells and on the binding of specific forms of retinoic acid. This implies that the parent compound, vitamin A, is available in adequate forms and quantities. Excessive dietary intake of vitamin A has been associated with teratogenicity in humans in <20 reported cases over 30 y. However, caution must be exercised to avoid unnecessary supplementation of women of childbearing age. Hypovitaminosis A affects millions of women and children worldwide. The main consequence of a poor vitamin A supply during pregnancy is a low vitamin A status at birth and in the next few months. Vitamin A deficiency is strongly associated with depressed immune function and higher morbidity and mortality due to infectious diseases such as diarrhea, measles, and respiratory infections. Vitamin A deficiency is often associated with an increased mother-to-child transmission of HIV-1. The initiation of vitamin A supplementation should be carefully examined in each case according to the risk-to-benefit ratio. The final decision should take into account the estimated vitamin A status of the woman, the availability of vitamin A-rich foods in her diet, and whether supplementation can be supervised.
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PMID:Vitamin A in pregnancy: requirements and safety limits. 1079 10

Discussions from a recent cancer conference held in May of 1995 are summarized in the following areas: 1) the effect of mitoguazone in relapsed non-Hodgkin's lymphoma; 2) the addition of ddI or ddC to chemo for advanced Kaposi's sarcoma (KS); 3) progress in use of three new anti-KS agents; 4) the effectiveness of phototherapy as palliation for KS; and 5) reasons why HIV prevalence is probably underestimated in women. Additionally, the paper reviews the Lymphoma Project Report which analyzed the epidemiology, pathogenesis, diagnosis, clinical manifestations, molecular characteristics, prognostic factors, and treatment of AIDS lymphoma. The following were among the findings: a regimen of doxorubicin, bleomycin, and vincristine with either ddI or ddC was well tolerated and evoked antitumor responses in patients with KS; 9-cis-retinoic acid and beta-human chorionic gonadotropin can induce remission of KS lesions; photodynamic therapy is an effective palliative therapy for some people with KS, but doses above 300 joules/cm2 result in scarring; and most American women who die of cervical cancer probably also have HIV infection according to a clinician from State University of New York in Brooklyn. The article concludes with a discussion of the differences between the focus of HIV research and HIV meetings for the ASCO assembly and the AIDS community.
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PMID:Oncologists scout new directions for KS and lymphoma therapies. 1136

Ligand Pharmaceuticals is seeking the Food and Drug Administration's (FDA) approval of Panretin gel (9-cis retinoic acid) to topically treat Kaposi's sarcoma (KS). Data indicate that the response rate to Panretin gel is independent of the strength of concurrent anti-HIV therapy. A capsule form of the drug is also being developed, and it has had a 37 percent response rate after 16 or more weeks of treatment, while the topical form resulted in improvement in about 35 percent of KS patients. The capsule form will be easier to use for patients with large numbers of lesions, and it may also be more effective against KS involving internal organs.
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PMID:KS drug goes to FDA. Food and Drug Administration. 1136 79

All-trans-retinoic acid (RA) has been shown either to activate or repress human immunodeficiency virus type 1 (HIV-1) replication in primary monocyte-derived-macrophages (MDMs). We systematically investigated the contribution that cell donor and virus differences make to this variability. We found that the effect of RA was cell donor dependent. In addition, the ability of RA to repress HIV-1 replication varied between different virus stocks. In no case did RA affect either virus entry or integration but instead affected the accumulation of viral mRNAs in infected cells. Despite the complex variability in RA responsiveness in untreated cells, we found that RA consistently repressed virus replication when the MDMs were treated with concentrations of interleukin 1 beta (IL-1 beta) and IL-6 that are expected at local sites of infection, where HIV-1-infected macrophages reside in vivo.
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PMID:Interleukin 1 beta and interleukin 6 potentiate retinoic acid-mediated repression of human immunodeficiency virus type 1 replication in macrophages. 1207 60


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