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

Stable transfection of H4 neuroglioma cells with the Epstein-Barr virus-based eucaryotic CD4 expression vector pKS286 generated the cell line, H4/CD4, in which greater than 90% of cells express surface CD4 receptors. Optimal conditions for infection of H4/CD4 cells with HIV-1 were determined; these included a cocultivation with growth-arrested, chronically infected T cells. Under these conditions, 3-days after infection up to 50% of H4/CD4 cells expressed HIV-1 antigens as detected by immunofluorescence assay, the number of intracellular HIV-1 RNA copies reached 10(3) molecules per cell as determined by liquid hybridization, and virus production ranged from 0.2 to 1.0 micrograms HIV-1 p24 core antigen per ml of culture supernatant, comparable to that measured under the same conditions in HIV-1 infected T cells. Giant cells and cytolysis were common. Inhibition of HIV-1 infection by nucleoside analogues in H4/CD4 cells was comparable to that in T cells, suggesting that the early stages of HIV-1 infection were similar in both cell systems. Infection in the presence of soluble CD4 reduced HIV-1 expression to the levels determined in CD4-negative H4 cells. This system may be useful for screening of drugs intended to block HIV-1 replication in the brain and for the evaluation of the HIV-1 life cycle in brain cells.
 ...
PMID:A system for the high efficiency replication of HIV-1 in neural cells and its application to anti-viral evaluation. 130 76

Human foamy virus (HFV) encodes the transcriptional transactivator bel1. The bel1 protein transactivates HFV long terminal repeat (LTR)-directed gene expression by recognizing a region in U3. It also transactivates human immunodeficiency virus type 1 (HIV-1) LTR-directed gene expression in transient transfection assays. To identify the specific region in HIV-1 LTR responsible for bel1 action, we examined the effect of bel1 on chloramphenicol acetyltransferase (CAT) gene expression in transfected cells with a series of mutant HIV-1 LTR/CAT plasmids. The region between -158 and -118 from the transcription initiation site, immediately upstream of the core enhancer element, was identified as responsible for the transactivation by bel1. In addition, bel1 transactivated a heterologous promoter when this region was positioned upstream of it in the sense and antisense orientations. Optimal transactivation of the HIV-1 LTR by bel1 did not require an intact TAR sequence, suggesting that the binding of tat to the TAR sequence is not a prerequisite for bel1 function in HIV-1 LTR-directed gene expression. In the region of the HIV-1 LTR that is necessary for the bel1-mediated transactivation, we have found a sequence which is conserved between HIV-1 and HFV. Our results suggest that the bel1 action on HIV-1 seems to be mediated by a specific DNA sequence which is shared by both the HIV-1 LTR and HFV LTR.
 ...
PMID:Transactivation of human immunodeficiency virus type 1 long terminal repeat-directed gene expression by the human foamy virus bel1 protein requires a specific DNA sequence. 131 28

The antiviral drug used in the treatment of acquired immunodeficiency syndrome, zidovudine, has proved effective in ameliorating the morbidity and mortality associated with human immunodeficiency virus infection. However, associated with zidovudine is the development of severe bone marrow toxicity manifested by anemia, neutropenia, and occasionally thrombocytopenia. We report the results of studies that demonstrate the ability of basic fibroblast growth factor (B-FGF) to reduce zidovudine toxicity to several classes of hematopoietic progenitors (granulocyte-macrophage, CFU-GM; megakaryocyte. CFU-Meg; and erythroid, BFU-E) from normal murine, human, and murine retrovirus-infected bone marrow cells when cocultured with zidovudine in vitro. Optimal response to B-FGF was observed at a dose concentration of 10 ng/ml. The specificity of B-FGF was demonstrated in the presence of protamine sulfate, an effective inhibitor of B-FGF mitogenic activity. In addition, synergistic activity of B-FGF on zidovudine-induced hematopoietic stem cell toxicity was observed in the presence of interleukin 1 (IL-1) (30 ng/ml). These studies demonstrate that B-FGF is capable of reducing the hematopoietic toxicity associated with zidovudine and that such an effect can be amplified in the presence of IL-1.
 ...
PMID:In vitro modulation of the toxicity associated with the use of zidovudine on normal murine, human, and murine retrovirus-infected hematopoietic progenitor stem cells with basic fibroblast growth factor and synergistic activity with interleukin-1. 131 78

A simple, rapid, reproducible and sensitive peptide-Time-Resolved-Fluoroimmunoassay (TR-FIA) method is described which allows the detection of antibodies to the Human Immunodeficiency Virus type 1 (HIV-1). By using a panel of synthetic peptide antigens that covered env, gag and pol amino acid sequences, a 20 amino acid peptide (GIWGCSGKLICTTAVPWNAS) describing an immunodominant and conserved domain on the gp41 region of the BH10 clone was found to be the most reactive in this study. Optimal conditions for antigen concentration, serum dilution and incubation time were established. The peptide-TR-FIA is specific, as assessed by testing HIV-1 positive sera which included samples from AIDS, ARC patients and HIV-positive drug users. The test was used to detect HIV antibodies in 250 well characterized HIV-1 positive sera and 50 normal sera. Peptide-TR-FIA results indicate that the env peptide was highly reactive with HIV-positive sera showing a sensitivity of 100%. None of the 50 control sera showed positive reactivity against the synthetic peptide. Furthermore the peptide-TR-FIA allowed a fine titration of antibodies to defined epitopes of immunodominant HIV structural proteins that usually cannot be achieved by peptide-ELISA assays.
 ...
PMID:Detection of antibodies to human immunodeficiency virus type I by using synthetic peptides and time-resolved fluoroimmunoassay (TR-FIA). 164 52

To determine whether HIV-1 tat can transactivate a heterologous promoter lacking HIV sequences other than the TAR element, TAR was placed downstream of the chicken beta-actin promoter. Tat increased expression directed by the actin-TAR promoter to a degree equal to tat induction of the HIV-1 LTR. Optimal transactivation was observed when TAR was positioned downstream of the actin promoter such that the expected cap site of transcripts from this promoter would be the same as in transcripts directed by the HIV-1 LTR. Tat was able to transactivate, though to a lesser extent, a promoter consisting solely of a TATA element fused to TAR. Thus, tat induction does not require HIV-1 LTR promoter sequences other than TAR. Tat, when fused to the DNA binding domain of BPV-1 E2, was able to transactivate a truncated SV40 promoter containing upstream E2 binding sites, indicating that tat may be capable of transactivation when directed by a DNA binding protein to an upstream site in a heterologous promoter lacking all HIV sequences. Substitution of Ala for Lys at position 41 of tat in the tat-E2 fusion, a mutation which dramatically decreases tat transactivation of the HIV-1 LTR, eliminated this transactivation.
 ...
PMID:Transactivation of heterologous promoters by HIV-1 tat. 166 14

Optimal management of human immunodeficiency virus type 1 (HIV-1) infections may require combinations of anti-HIV-1 agents. Zidovudine (AZT, 3'-azido-3'-deoxythymidine), didanosine (ddI, 2',3'-dideoxyinosine), and recombinant interferon-alpha A (rIFN-alpha A) were evaluated in two-drug regimens against replication of AZT-resistant HIV-1 in vitro. AZT-sensitive and AZT-resistant isolate pairs derived from two individuals before and after extended AZT monotherapy were studied. Drug interactions using peripheral blood mononuclear cells infected with HIV-1 were evaluated mathematically. Synergistic interactions were seen among AZT, ddI, and rIFN-alpha A in two-drug regimens against AZT-resistant HIV-1 in vitro, even when AZT was included in the treatment regimen. Mixtures of wild-type and mutant reverse transcriptase genes were found in one of the late-AZT therapy isolates, suggesting that the mechanism of synergy of AZT-containing regimens may involve inhibition of AZT-sensitive viruses in the viral pool. These studies suggest that AZT may be useful in drug combination regimens, even when AZT-resistant viruses are isolated in vitro.
 ...
PMID:Two-drug combinations of zidovudine, didanosine, and recombinant interferon-alpha A inhibit replication of zidovudine-resistant human immunodeficiency virus type 1 synergistically in vitro. 171 49

Endocrine manifestations of HIV infection include both pathological changes and disturbances in function. Mechanisms include direct infection of glands by HIV or opportunistic organisms, infiltration by neoplasms, side effects of drugs, and production of humoral factors that may alter metabolism. The adrenal gland is most often affected, but virtually every endocrine system may be involved. Dysfunction is often subtle, with symptoms overlapping those of the HIV infection itself. Endocrine manifestations may be found at any time in the course of the disease, from the asymptomatic HIV-positive stage through full-blown AIDS. Optimal management of these patients may include a careful search for, and appropriate treatment of, associated endocrine abnormalities.
 ...
PMID:Endocrine manifestations of human immunodeficiency virus (HIV) infection. 189 56

In a prospective study 21 patients suffering from HIV-1 infection underwent MR imaging. The following tumours were found: eight Kaposi's sarcomas, four lymphomas, two squamous-cell carcinomas, and three cases of lymphoid hyperplasia. Furthermore, three cases with lymphoepithelial cysts and one case of inflammatory changes of the parotid glands were studied. Optimal diagnostic results were obtained by using T1- and T2-weighted sequences plain and Gd-DTPA enhanced. Different signal intensities enabled the differentiation of lesions such as inflammation, lymphomas and lymphoid hyperplasia. Besides clinical examination modalities, MR imaging proves to be an important tool in investigating solid, cystic or inflamed processes in HIV-positive patients in the head and neck area.
 ...
PMID:[NMR tomographic diagnosis with Gd-DTPA in HIV-associated diseases in the head-neck area]. 191 38

There is a paucity of published information available on extrapulmonary cryptococcosis (EC) in children infected with human immunodeficiency virus, the etiologic agent of the acquired immunodeficiency syndrome. We surveyed investigators in pediatric acquired immunodeficiency syndrome around the country regarding their experience with EC. Investigators from 33 (87%) of 38 institutions responded and information on 13 patients from 11 institutions was analyzed. EC was the acquired immunodeficiency syndrome indicator disease in 9 (69%) of 13 patients. Median age was 8 years with a range of 2 to 17 years. Human immunodeficiency virus risk factors were transfusion (5 patients), hemophilia (4 patients) and perinatal exposure (4 patients). Meningitis, seen in 62% of patients, was the most common clinical manifestation. Although 2 patients with fulminant disease died before therapy was started, 10 (91%) of 11 had a clinical response to amphotericin B with or without flucytosine. Our study indicates a spectrum of EC in pediatric human immunodeficiency virus infection ranging from fulminant, fatal fungemia to chronic meningitis and fever of unknown origin. Cryptococcosis was generally not the cause of death in patients who initially responded to amphotericin B therapy. Optimal antifungal therapy, including the role of fluconazole, warrants further study.
 ...
PMID:Extrapulmonary cryptococcosis in children with acquired immunodeficiency syndrome. 192 78

We have investigated the optimal reaction conditions and the limiting sensitivity for detection of HIV-1 DNA by PCR. The amplification systems studied were gag (SK38/SK39); pol (P3/P4); and two other systems described here for the first time, LTR (LTR1/LTR2) and nef (Nef1/Nef2), which amplify fragments of 115 bp, 308 bp, 632 bp and 643 bp, respectively. Two PCR profiles were assayed, and the requirements for deoxynucleoside triphosphate and MgCl2 concentrations for each amplification reaction were determined. Optimal reaction conditions were oriented toward selecting maximal amplification of the expected size fragment. Limiting sensitivity was estimated by testing the decreasing copy number of a plasmid containing HIV-1 genome and obtaining a positive amplification signal with at least 5, 5, 10 and 5 copies for LTR, gag, pol and nef, respectively. We conclude that the establishment of the detection sensitivity on a PCR is an important parameter to be considered for the interpretation of results on HIV-1 infection.
 ...
PMID:Influence of PCR parameters on amplifications of HIV-1 DNA: establishment of limiting sensitivity. 193 Oct 39


1 2 3 4 5 6 7 8 9 10 Next >>