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

DNA amplification assays such as the polymerase chain reaction are being developed for the amplification of small quantities of microbial nucleic acids. These assays offer the potential for a great deal of sensitivity. However, the high level of sensitivity increases the likelihood of cross-contamination of amplified products and the generation of false-positive reactions. In addition, substances in body fluids can inhibit the efficient performance of the amplification reactions. We have developed an assay format in which microbial nucleic acids are specifically bound to a solid phase surface. Contaminating DNA and enzyme inhibitors present in the sample are removed by washing prior to the performance of the amplification reaction. We could use this system to amplify and detect small amounts of HIV DNA diluted in whole blood. The assay system could distinguish target DNA from contaminating DNA fragments generated by prior amplification reactions.
Mol Cell Probes 1991 Apr
PMID:Solid phase capture method for the specific amplification of microbial nucleic acids--avoidance of false-positive and false-negative reactions. 207 36

We describe inosine-substituted 'consensus' primers for the detection of HIV-1 envelope sequences by the polymerase chain reaction. The primers, modifications of SK68 and SK69, are highly specific (100%) and sensitive (greater than 94%) and they prevent false-negative results due to variation in the HIV-1 genome. Consensus primers are needed to ensure the detection of most, if not all, variants of HIV-1 including American, African and newly emerging strains.
Mol Cell Probes 1991 Apr
PMID:Improved detection of HIV-1 envelope sequences using optimized PCR and inosine-substituted primers. 207 37

Monkey kidney cells CV-1 were infected with recombinant vaccinia virus carrying HIV-1 gag gene with a deletion of 230 nucleotide pairs from the 3'-terminus. The main gene product detected in the lysates of infected cells was the gag precursor rp50. The protein was accumulated on the cell membranes suggesting that it had a myristylated N-terminus, and was cleaved by a recombinant virus specific protease with the formation of two proteins, p17 and p24 corresponding in molecular masses to mature gag proteins. Virus-like particles similar to immature HIV virions were budding from the surface of infected cells. They look like the ring of optically dense material covered with a lipid bilayer, of the same size (100-120 nm) and of the same density in a sucrose gradient (1.16-1.18 g/ml) as HIV-1 virions. The particles contained rp50 and cellular heterogeneous RNA. Thus, the unprocessed gag precursor with deleted 77 amino acid residues from the C-terminus is able to form virus-like particles in the absence of env proteins and virus-specific RNA, and these particles are budding from the cell surface. The question about the use of extracellular Gag-particles for AIDS diagnostic work and construction of vaccines is discussed.
Mol Biol (Mosk)
PMID:[Formation of virus-like particles by HIV-1 Gag proteins, expressed by a recombinant vaccinia virus]. 209 14

A synthetic peptide corresponding to the third complementarity determining region (CDR) of the heavy chain (CDR3VH) of anti-Leu3a, a monoclonal anti-CD4 antibody which inhibits HIV gp120 binding to CD4, was used to elicit specific anti-peptide antibodies in rabbits. The anti-peptide antisera showed anti-idiotypic antibody (anti-Id) activity and recognized both the immunizing peptide and the intact cognate protein by ELISA. In addition, the antisera reacted with isolated heavy chains of anti-Leu3a by Western blot analysis. The lack of reactivity with a panel of monoclonal anti-CD4 antibodies suggested that the anti-peptide antisera recognize a private idiotype (Id) associated with the anti-Leu3a CDR3VH region. Further studies demonstrated the inability of the rabbit antisera to inhibit the binding of anti-Leu3a to the CD4 molecule. In addition, soluble recombinant CD4 was unable to inhibit the binding of the rabbit anti-peptide antisera to anti-Leu3a indicating that the CDR3VH region may not be involved in CD4 recognition. Anti-Id containing sera from mice, rabbits and nonhuman primates immunized with the intact anti-Leu3a molecule did not bind the CDR3VH synthetic peptide, suggesting that the corresponding region of anti-Leu3a may not represent an immunodominant idiotypic determinant in thes e species. These results suggest the potential use of synthetic peptides corresponding to immunoglobulin variable (V) region amino acid sequences in generating anti-Id reagents of a predefined specificity. In addition, V-region synthetic peptides may be useful in mapping the idiotopes recognized by an anti-Id response to the cognate molecule.
Mol Immunol 1990 Jun
PMID:Anti-idiotypic antibodies of a predefined specificity generated against CDR3VH synthetic peptides define a private anti-CD4 idiotype. 211 95

We have devised a sensitive and convenient hybridization technique by combining the polymerase chain reaction (PCR) with affinity-based hybrid collection. In this method 5'-biotinylated primers are used to introduce biotin residues into the DNA fragments during the amplification. The amplified DNA fragments are detected by liquid hybridization using a 32P- or 35S-labelled oligonucleotide as probe. For measurement the hybrids are collected on polystyrene microparticles or onto microtitre wells taking advantage of the biotinavidin interaction. The method is highly sensitive allowing the detection of 30 molecules of DNA. It involves few and simple operations, and is thus suitable for routine diagnostics. The applicability of the method to the detection of HIV-1 DNA from blood, HCMV DNA from urine and HPV-16 DNA from cervical scrapes was evaluated.
Mol Cell Probes 1990 Jun
PMID:Affinity-based collection of amplified viral DNA: application to the detection of human immunodeficiency virus type 1, human cytomegalovirus and human papillomavirus type 16. 216 37

Regulation of eukaryotic genes is largely governed by multiple cis-acting DNA sequences recognized by specific transcription factors. The transcription factor NF-kappa B has been implicated as an important regulator of cellular and viral genes, including those of immunoglobulin kappa light chain, interleukin-2, beta-interferon, HIV-1 and cytomegalovirus. We have analyzed the effect of increasing the number of NF-kappa B sites, located directly upstream from the TATA box. Four copies of the sequence gave a more than 100-fold stimulation relative to a single copy, suggesting that NF-kappa B proteins act synergistically to bring about this dramatic increase in transcription. By DNase I footprinting we demonstrated factor binding to two adjacent NF-kappa B sites in vitro. However, we found no evidence for co-operative binding to these DNA sites. We propose that the high transcriptional activity results from another type of co-operation, based on multiple weak interactions of the NF-kappa B factors with another component of the transcription apparatus, perhaps RNA polymerase II itself.
J Mol Biol 1990 Jul 20
PMID:Synergistic activation of transcription by multiple binding sites for NF-kappa B even in absence of co-operative factor binding to DNA. 219 80

3'-Azido-2',3'-dideoxyuridine (AzdU, CS-87) is a potent inhibitor of human immunodeficiency virus replication in human peripheral blood mononuclear cells (PBMC) with limited toxicity for human bone marrow cells (BMC). In the present study, metabolism of AzdU was investigated in human PBMC and BMC after exposure of cells to 2 or 10 microM [3H]AzdU. 3'-Azido-2',3'-dideoxyuridine-5'-monophosphate (AzdU-MP) was the predominant metabolite, representing approximately 55 to 65% of intracellular radioactivity in both PBMC and BMC at all times. The AzdU-5'-diphosphate and -5'-triphosphate intracellular levels were 10- to 100-fold lower than the AzdU-MP levels and, of note, AzdU-5'-triphosphate was not detected in human BMC. Using anion exchange chromatography, a new peak of radioactivity, distinct from any known anabolites, was detected. This chromatographic peak was found to be resistant to alkaline phosphatase but was hydrolyzed by 5'-phosphodiesterase, yielding AzdU-MP. Incubation of [3H]AzdU and D-[1-14C]glucose in PBMC and BMC produced a double-labeled peak with the same retention time as the anabolite, suggesting formation of a hexose derivative of AzdU. A novel high performance liquid chromatography method was developed that allowed for the separation of nucleosides, nucleotides, and carbohydrate derivatives thereof. Using this highly specific method, the putative AzdU-hexose actually was separated into two chromatographic peaks. These novel metabolites were identified as 3'-azido-2',3'-dideoxyuridine-5'-O-diphosphoglucose and 3'-azido-2',3'-dideoxyuridine-5'-O-diphospho-N-acetylglucosamine. Following 48 hr of incubation with [3H] AzdU, as much as 20 and 30% of these AzdU metabolites accumulated in PBMC and BMC, respectively. When AzdU was removed from the cell cultures, intracellular AzdU diphosphohexose concentrations decayed in a monophasic manner, with an elimination half-life of 14.3 hr. By 48 hr, levels of 0.3 pmol/10(6) cells were still detected, reflecting a gradual anabolism of these metabolites. Elimination of AzdU-MP and AzdU-5'-diphosphate was characterized by a two-phase process, with a short initial half-life of 0.83 and 0.24 hr and a long terminal half-life of 14.10 and 8.24 hr, respectively. Similar diphosphohexoses of deoxyuridine (dUrd) were also detected in human PBMC and BMC after exposure to [3H]dUrd, suggesting that dUrd derivatives are metabolized in a similar manner. In summary, the discovery of novel metabolic pathways for dUrd analogs demonstrates that AzdU has unique metabolic features that may contribute to the low toxicity of this anti-HIV agent in human BMC and also affect its mechanism of action.(ABSTRACT TRUNCATED AT 400 WORDS)
Mol Pharmacol 1990 Dec
PMID:Cellular metabolism of 3'-azido-2',3'-dideoxyuridine with formation of 5'-O-diphosphohexose derivatives by previously unrecognized metabolic pathways for 2'-deoxyuridine analogs. 225 Jun 66

A monoclonal IgG antibody directed against gp 41 from the human immunodeficiency virus (HIV-1) has been crystallized in both intact and Fab forms. Crystals of the intact antibody grow as tetragonal-like prisms too small for conventional X-ray analysis. However, the Fab portion of the antibody produces suitable plate-like crystals which belong to the space group P2(1)2(1)2(1) with unit cell constants of a = 66.5 A, b = 74.3 A and c = 105.3 A. There is one molecule of Fab in the asymmetric unit. The Fab crystals show diffraction to d-spacings less than 3.0 A.
J Mol Biol 1990 Dec 05
PMID:Crystallization of the Fab from a human monoclonal antibody against gp 41 of human immunodeficiency virus type I. 225 26

Carbovir (CBV) is a highly selective carbocyclic nucleoside inhibitor of HIV replication in human lymphocytes and is potentially useful in the treatment of AIDS [Vince et al. (1988) Biochem. Biophys. Res. Commun. 156, 1046-1053]. Using human lymphoid cells severely deficient in nucleoside kinases, we were able to identify the route of activation of CBV metabolism. The present studies have demonstrated that CBV is anabolized to the mono-, di-, and triphosphates and to guanosine 5'-triphosphate in CCRF-CEM cells. Conversion to GTP amounted to 15-20% of the total analogue nucleotides formed in the cells and may arise from CBV through depurination and salvage via HGPRT. Evidence was obtained that neither deoxycytidine kinase, adenosine kinase, or mitochondrial deoxyguanosine kinase is primarily involved in the initial step of phosphorylation of CBV in CCRF-CEM cells. In contrast, earlier studies [Johnson & Fridland (1989) Mol. Pharmacol. 36, 291-295] showed that a cytosolic 5'-nucleotidase catalyzes the activation of CBV to the monosphosphate. Other biochemical effects examined showed that the nucleobases hypoxanthine and adenine, but not guanine, their respective nucleosides, and the dideoxynucleosides 2',3'-dideoxyinosine, 2',3'-dideoxyguanosine, and 3'-azido-3'-deoxythymidine produced significant increased accumulation of CBV nucleotides in CEM cells. The exact mechanism for this potentiation of CBV phosphorylation has not been elucidated but may be due to a modulating effect of intracellular nucleotides on 5'-nucleotidase activity.
 ...
PMID:Metabolism of the carbocyclic nucleoside analogue carbovir, an inhibitor of human immunodeficiency virus, in human lymphoid cells. 227 22

Human immunodeficiency virus type 1 (HIV-1) can be isolated from lymphocytes and tissues of symptomatic and asymptomatic seropositive subjects. However, in some individuals, virus isolation is not always positive, especially in asymptomatics. In this paper we report the results of HIV-1 DNA detection by means of polymerase chain reaction (PCR), a new technique that permits the amplification of specific DNA sequences. PCR was carried out to amplify two highly conserved env regions on samples from 20 normal individuals used as controls, 20 seropositive patients at different stages of HIV disease and 25 seronegative individuals at high risk for infection, such as sexual partners of seropositive patients and intravenous drug addicts. Eighteen out of 20 seropositive subjects were positive by PCR while among seronegatives HIV DNA was detected in 7/25 individuals. Virus isolation was positive only in 2/7. These subjects, followed for HIV antibody production for a period of 10-12 months, remained seronegative except one case who seroconverted after a few weeks. Long latency of HIV infection without detectable antibodies seems prevalent in these subjects. PCR assay represents a useful technique for identifying proviral sequences in seronegative high-risk individuals, to confirm the infection during its early phases and during the follow-up of patients with HIV disease.
Mol Cell Probes 1990 Apr
PMID:Proviral sequences detection of human immunodeficiency virus in seronegative subjects by polymerase chain reaction. 236 63


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