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

In order to increase the virus safety of a solvent/detergent-treated Factor VIII concentrate in regard to non-lipid coated viruses and to respond to the continuous discussion about reports on hepatitis A transmission by Factor VIII preparations, we have investigated the effect of a terminal dry heat treatment (30 min 100 degrees C) on HAV and various other viruses. By this treatment Hepatitis A virus was inactivated below detectable level after a few minutes (> 5.3 log10). Other RNA viruses such as the Human Immunodeficiency Virus (> 6.6 log10), bovine viral diarrhoea virus (> 6.6 log10) and vesicular stomatitis virus (> 5.8 log10) were also inactivated below detectable level. Pseudo rabies virus and reovirus Type 3 are inactivated by 5.7 and > 6.0 log10, respectively. SV40 and bovine parvo virus showed significant resistance to dry heat treatment. We conclude that the involvement of two strong virus inactivation steps, acting by different mechanisms, improves the virus safety of Factor VIII concentrates without destroying the Factor VIII activity. Moreover, the terminal 100 degrees C heat treatment for 30 min represents an effective measure to inactivate non-lipid enveloped viruses, in particular hepatitis A, which is resistant to solvent/detergent treatment.
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PMID:Improvement of virus safety of a S/D-treated factor VIII concentrate by additional dry heat treatment at 100 degrees C. 888 59

Systemic non-Hodgkin's lymphoma and Kaposi's sarcoma occur in approximately 4% and 30% of patients with HIV infection, respectively. Single-agent or combination chemotherapy is often indicated for such patients. Combination chemotherapy produces a significant decrease in CD4 lymphocytes and significantly increases the risk of opportunistic infection. Supportive care should include prophylaxis against Pneumocystis carinii pneumonia and esophageal candidiasis. Herpes labialis frequently occurs, may be confused with chemotherapy-induced stomatitis, and it requires appropriate treatment and secondary prophylaxis once recognized. Antiretroviral therapy should be continued during chemotherapy, if possible, and should be selected based on the patient's prior antiretroviral exposure, the toxicity profile of the antiretroviral agent, the toxicity of the chemotherapy, and the potential for drug interaction. The use of hematopoietic growth factors as primary prophylaxis may be reasonable for patients at high risk for febrile neutropenia, although the information about their use in this population is limited.
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PMID:Infection prophylaxis and antiretroviral therapy in patients with HIV infection and malignancy. 891 6

The use of Moloney murine leukemia virus (Mo-MLV)-based vectors to deliver therapeutic genes into target cells is limited by their inability to transduce nondividing cells. To test the capacity of HIV-based vectors to deliver genes into nondividing cells, we have generated replication-defective HIV type 1 (HIV-1) reporter vectors carrying neomycin phosphotransferase or mouse heat stable antigen, replacing the HIV-1 sequences encoding gp160. These vectors also harbor inactive vpr, vpu, and nef coding regions. Pseudotyped HIV-1 particles carrying either the ecotropic or the amphotropic Mo-MLV envelope proteins or the vesicular stomatitis virus G protein were released after single or double transfections of either human 293T or monkey COS-7 cells with titers of up to 10(7) colony-forming units per milliliter. A simple ultrafiltration procedure resulted in an additional 10- to 20-fold concentration of the pseudotyped particles. These vectors along with Mo-MLV-based vectors were used to transduce primary human skin fibroblasts and human peripheral blood CD34+ cells. The HIV-1 vector system was significantly more efficient than its Mo-MLV-based counterpart in transducing human skin fibroblasts arrested at the G0/G1 stage of the cell cycle by density-dependent inhibition of growth. Human CD34+ cells were transduced efficiently using HIV-1 pseudotype particles without prior stimulation with cytokines.
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PMID:Transduction of nondividing cells using pseudotyped defective high-titer HIV type 1 particles. 898 99

Gene transfer into haematopoietic stem cells (HSC) has been investigated for treatment of genetic disorders, conferral of chemotherapy resistance and insertion of genes to inhibit HIV-1 replication. Methods have been available for almost a decade to transduce murine HSC using high-titre retroviral vectors and stimulation of HSC proliferation with cytokines such as IL-3 and IL-6. Unfortunately, attempts to replicate the high efficiency of gene transfer using canine or simian gene transfer/bone marrow transplantation models have consistently shown that only a small fraction (0.1-1%) of reconstituting HSC are transduced using protocols similar to those which are successful in murine models. Initial clinical trials using retroviral-mediated gene transfer into human HSC also produced minimal transduction frequencies. The dicotomous results may reflect differences in the cell cycle kinetics of murine HSC versus those of larger mammals or the density of receptors for the retroviral vectors on the cells. Attempts to increase the fraction of HSC which are in active cell cycle, a prerequisite for retroviral-mediated transduction, have used either combinations of recombinant cytokines, culture on marrow stromal layers, or alternative sources for HSC, such as mobilized peripheral blood stem cells or umbilical cord blood. Other efforts have used retroviral vectors packaged with either the Gibbon Ape Leukemia virus envelope or the Vesicular Stomatitis Virus G protein. To date, none of these methods has produced a significantly increased frequency of long-term reconstituting HSC. Results using adeno-associated virus (AAV)-based vectors for HSC transduction have been conflicting, with the stable persistence of non-integrated virus particles making interpretation of results difficult using in vitro assays. Therefore, clinical trials may best be directed toward disorders that may benefit from a small fraction of genetically corrected HSC. These would include disorders where progeny of corrected HSC would be expected to have a selective survival advantage (e.g. SCID, WAS, HIV, chemoresistance) or where a small fraction of corrected cells can have a direct clinical benefit (e.g. CGD, MPS). Further basic research into HSC biology and gene delivery vectors must continue for wider application, such as haemoglobinopathies and some lysosomal storage diseases.
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PMID:Gene therapy for haematopoietic and lymphoid disorders. 902 Sep 37

omega-Acryloyl anionic surfactants, whose polar heads are derived from amino acids, have been telomerized to prepare polyanions of a predetermined molecular weight. The main goal of this study was to verify whether the antiviral activity is influenced by the degree of polymerization of the polyanions. The oligomeric polyanions were evaluated for their activity against human immunodeficiency virus (HIV-1 or HIV-2) and various other RNA and DNA viruses. With regard to their anti-HIV activity, a minimum number of anionic groups was necessary to achieve an inhibitory effect. Moreover, to be active the overall conformation of the polyanion must be such that the anionic groups are located on the external site of the molecule. With some of the polyanions, a 50% inhibition concentration (IC50) as low as 1 microgram/ mL, or even 0.1 microgram/mL, was noted against HIV-1 in CEM-4 and MT-4 cells, respectively. The most potent polyanions also proved active against human cytomegalovirus and herpex simplex virus at concentrations of 5-10 and 20-40 micrograms/mL, respectively. No activity was observed against any of the other viruses tested (i.e., vesicular stomatitis, Sindbis, Semliki forest, parainfluenza, Junin, Tacaribe, Coxsackie, polio, reo, and vaccinia). No toxicity for the host cells was observed at concentrations up to 200 micrograms/mL.
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PMID:Polyanion inhibitors of human immunodeficiency virus and other viruses. 5. Telomerized anionic surfactants derived from amino acids. 902

A new class of polyanionic compounds, inhibitors of human immunodeficiency virus, was obtained from radical addition of mercapto acid or mercapto ester on a perallylated carbohydrate under UV irradiation with a catalytic amount of AIBN. Unlike the polyanions that we have previously prepared by polymerization reactions, the compounds are structurally well defined. Polyanions bearing 16 carboxylate groups showed a 50% inhibitory concentration (IC50) of 0.1-4.1 micrograms/mL against HIV-1 in MT-4 cells while not being toxic to the host cells at concentrations up to 125 micrograms/mL. The most potent polyanions also proved active against human cytomegalovirus at concentrations of 1-14 micrograms/mL. No activity was observed against any of the other viruses tested (i.e., herpes simplex virus, vesicular stomatitis virus, Sindbis, Semliki forest, parainfluenza-3, Junin, Tacaribe, Coxsackie B4, polio-1, reo-1, or vaccinia virus).
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PMID:Polyanion inhibitors of human immunodeficiency virus and other viruses. 6. Micelle-like anti-HIV polyanionic compounds based on a carbohydrate core. 902 1

The human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein was expressed by a vaccinia vector that encodes the late promotor P11. The envelope protein synthesized mediated syncytia formation with SupT1 cells and was efficiently cleaved to produce mature gp120 and gp41 in CV-1 cells. gp 160 precursor processing was neither affected by a change in culture medium nor by a heterologous vesicular stomatitis virus coinfection. These results suggest that the proteolytic cleavage of gp160 is an efficient process and that coinfection with other viruses may not affect precursor processing of the HIV-1 Env protein.
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PMID:Expression and processing of the human immunodeficiency virus type 1 envelope glycoprotein. 907 65

Zalcitabine is a dideoxynucleoside antiretroviral agent that is phosphorylated to the active metabolite 2',3'-dideoxycytidine 5'-triphosphate (ddCTP) within both uninfected and HIV-infected cells. At therapeutic concentrations, ddCTP inhibits HIV replication by inhibiting the enzyme reverse transcriptase and terminating elongation of the proviral DNA chain. The results of 3 large pivotal trials comparing zidovudine monotherapy with combination therapy have now clearly established that zalcitabine plus zidovudine combination with an improvement in viral load and CD4+ cell count compared with zidovudine monotherapy. More recently, clinical end-point and surrogate marker data have established the efficacy of zalcitabine in combination with the protease inhibitor saquinavir in zidovudine-experienced patients. Other studies have demonstrated the utility of zalcitabine in combination with ritonavir and the nucleoside analogue lamivudine. Importantly, early use of zalcitabine in the treatment sequence does not appear to limit the therapeutic efficacy of subsequent therapy with other nucleoside analogues such as lamivudine. Peripheral neuropathy is the most frequent dose-limiting adverse effect associated with zalcitabine therapy and is generally reversible on discontinuation of treatment. Stomatitis and mouth ulcers may occur frequently with zalcitabine therapy but tend to resolve with continuing treatment. Haematological toxicity, which is a common adverse effect associated with zidovudine, is reported infrequently with zalcitabine. Overall, combination therapy with zalcitabine plus zidovudine or saquinavir has been shown to have a tolerability profile comparable to that of either agent alone, although treatment with zidovudine plus zalcitabine was associated with a significant increase in the incidence of haematological toxicity compared with zidovudine monotherapy in one study. Therefore, current data suggest that zalcitabine is a useful antiretroviral agent for inclusion as a component of initial double combination therapy with zidovudine or as part of triple combination therapy including zidovudine plus a protease inhibitor in the management of patients with HIV infection.
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PMID:Zalcitabine. An update of its pharmacodynamic and pharmacokinetic properties and clinical efficacy in the management of HIV infection. 917 31

Human immunodeficiency virus type 1 (HIV-1) normally enters cells by direct fusion with the plasma membrane. In this report, HIV-1 particles capable of infecting cells through an endocytic pathway are described. Chimeric viruses composed of the HIV-1 core and the envelope glycoprotein of vesicular stomatitis virus (VSV-G) were constructed and are herein termed HIV-1(VSV) pseudotypes. HIV-1(VSV) pseudotypes were 20- to 130-fold more infectious than nonpseudotyped HIV-1. Infection by HIV-1(VSV) pseudotypes was markedly diminished by ammonium chloride and concanamycin A, a selective inhibitor of vacuolar H+ ATPases, demonstrating that these viruses require endosomal acidification to achieve productive infection. HIV-1 is thus capable of performing all of the viral functions necessary for infection when entry is targeted to an endocytic route. Maximal HIV-1 infectivity requires the presence of the viral Nef protein and the cellular protein cyclophilin A (CyPA) during virus assembly. Pseudotyping by VSV-G markedly suppressed the requirement for Nef. HIV-1(VSV) particles were also resistant to inhibition by cyclosporin A; however, the deleterious effect of a gag mutation inhibiting CyPA incorporation was not relieved by VSV-G. These results suggest that Nef acts at a step of the HIV-1 life cycle that is either circumvented or facilitated by targeting virus entry to an endocytic pathway. The findings also support the hypothesis that Nef and CyPA enhance HIV-1 infectivity through independent processes and demonstrate a mechanistic difference between reduction of HIV-1 infectivity by cyclosporin A and gag mutations that decrease HIV-1 incorporation of CyPA.
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PMID:Pseudotyping human immunodeficiency virus type 1 (HIV-1) by the glycoprotein of vesicular stomatitis virus targets HIV-1 entry to an endocytic pathway and suppresses both the requirement for Nef and the sensitivity to cyclosporin A. 922 76

We previously reported that in vitro culture of human peripheral blood monocytes resulted in a time-dependent differentiation into macrophages and in an enhanced capacity for producing certain cytokines [i.e., tumor necrosis factor alpha, interleukin-6 (IL-6), and interferon-beta (IFN-beta)] in response to bacterial lipopolysaccharide (LPS). HIV-1 infection or gp120 treatment of monocyte/macrophages resulted in the induction of low levels of IFN-beta, which were very effective in restricting viral replication in 7-day cultured macrophages but not in freshly isolated cells. This enhanced response of macrophages was due to a higher sensitivity of these cells to the antiviral effect of IFN-beta. Consistent with this finding, 7-day cultured macrophages exhibited higher levels of type I IFN receptors than 1-day cultured monocytes. Treatment of monocyte/macrophages with gp120 also caused a marked increase in IL-10 secretion, regardless of the differentiation state. No IL-12 secretion was detected in monocyte/macrophage cultures treated with gp120 alone. However, consistent IL-12 secretion was found in 7-day cultured macrophages primed with IFN-beta and subsequently stimulated with gp120. Macrophages responded more efficiently than monocytes to the priming effect of IFN-beta for IL-12 production. This was consistent with a stronger antiviral response against vesicular stomatitis virus by these cells as well as with a higher expression of IFN-beta receptors. The finding that the acquisition of the macrophage phenotype is associated with an increased capacity to respond to environmental signals (such as type I and type II IFNs) underlines the importance of the differentiation process for the selection of a certain repertoire of responses that may allow these cells to have important functions in vivo.
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PMID:Induction of cytokines by HIV-1 and its gp120 protein in human peripheral blood monocyte/macrophages and modulation of cytokine response during differentiation. 922 92


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