Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Reverse transcriptase (RT) was first discovered as an essential catalyst in the biological cycle of retroviruses. However, in the past years evidence has accumulated showing that RTs are involved in a surprisingly large number of RNA-mediated transpositional events that include both viral and nonviral genetic entities. Although it is probable that some RT-bearing genetic elements like the different types of AIDS viruses and the mammalian LINE family have arisen in recent geological times, the possibility that reverse transcription first took place in the early Archean is supported by (1) the hypothesis that RNA preceded DNA as cellular genetic material; (2) the existence of homologous regions of the subunit tau of the E. coli DNA polymerase III with the simian immunodeficiency virus RT, the hepatitis B virus RT, and the beta' subunit of the E. coli RNA polymerase (McHenry et al. 1988); (3) the presence of several conserved motifs, including a 14-amino-acid segment that consists of an Asp-Asp pair flanked by hydrophobic amino acids, which are found in all RTs and in most cellular and viral RNA polymerases. However, whether extant RTs descend from the primitive polymerase involved in the RNA-to-DNA transition remains unproven. Substrate specificity of the AMV and HIV-1 RTs can be modified in the presence of Mn2+, a cation which allows them to add ribonucleotides to an oligo (dG) primer in a template-dependent reaction. This change in specificity is comparable to that observed under similar conditions in other nucleic acid polymerases. This experimentally induced change in RT substrate specificity may explain previous observations on the misincorporation of ribonucleotides by the Maloney murine sarcoma virus RT in the minus and plus DNA of this retrovirus (Chen and Temin 1980). Our results also suggest that HIV-infected macrophages and T-cell cells may contain mixed polynucleotides containing both ribo- and deoxyribonucleotides. The evolutionary significance of these changes in substrate specificities of nucleic acid polymerases is also discussed.
J Mol Evol 1992 Dec
PMID:On the early emergence of reverse transcription: theoretical basis and experimental evidence. 128 61

We report a 39-year-old man who had AIDS and who presented with an unusual cutaneous vascular lesion, which was clinically thought to be Kaposi's sarcoma. Histologically, the lesion was characterized by capillary proliferation and a mixed inflammatory infiltrate that included numerous histiocytes. The lesion was found to contain slender intracellular acid-fast bacilli, as well as plump extracellular Warthin-Starry-positive bacilli. The acid-fast bacilli were confirmed to be Mycobacterium avium-intracellulare by subsequent positive blood cultures for this organism. To further investigate the lesion, polymerase chain reaction DNA amplification and sequencing was performed, and the lesion was found to contain DNA sequences identical to those previously established for the agent of bacillary angiomatosis. The lesion is thought to represent a lesion of bacillary angiomatosis with secondary involvement by M. avium-intracellulare.
Diagn Mol Pathol 1992 Sep
PMID:Localization of Mycobacterium avium-intracellulare within a skin lesion of bacillary angiomatosis in a patient with AIDS. 128 77

The low copy number of human immunodeficiency virus 1 (HIV-1) DNA infected cells precludes routine detection by in situ hybridization. The inability to detect cells latently infected by HIV-1 makes difficult the study of factors that induce viral transcription, an essential factor in the development of the acquired immune deficiency syndrome (AIDS). A sensitive and rapid technique to detect HIV-1 DNA could be used as a diagnostic test for AIDS and to differentiate latent versus active viral infection. We describe a 3-h technique whereby HIV-1 DNA is amplified by hot start polymerase chain reaction (PCR) and detected directly in infected cells. The specificity of the assay was demonstrated by double labeling the positive cells with CD4. Using a CR10 HIV-1-infected cell line, the 90% of cells that were HIV-1 DNA positive could be distinguished from the 10% that were actively expressing HIV-1 RNA. The PCR in situ technique should allow for the direct localization of DNA sequences in cells that would otherwise be undetectable by conventional in situ analysis.
Diagn Mol Pathol 1992 Jun
PMID:Rapid in situ detection of PCR-amplified HIV-1 DNA. 136 73

Five strains of human immunodeficiency virus type 1 (HIV-1) were isolated from five Japanese hemophilia patients. Two isolates, HIV-1[GUN-1] and HIV-1[GUN-2], were from brother patients with hemophilia B and the other three isolates, HIV-1[GUN-3], HIV-1[GUN-4], and HIV-1[GUN-5], were from hemophilia A patients. Another HIV-1 strain, HIV-1[GUN-6], was isolated from a Canadian male homosexual with AIDS. The restriction endonuclease cleavage maps of the proviral genomes of these six HIV-1 strains revealed that they were apparently different from each other. The phylogenetic trees constructed using restriction maps and nucleotide sequences were quite similar, indicating that phylogenetic analyses of Japanese HIV-1 isolates can be done using restriction maps of the proviruses. Phylogenetic analyses showed that they were more closely related to HIV-1s which had been reported to be isolated from homosexual patients in the United States than those isolated from African patients. In particular, GUN-1 and GUN-2 isolates were on the branch of a San Francisco isolate, ARV2, while GUN-5 and GUN-6 isolates were on the branch of HTLV-IIIB-related isolates.
J Mol Evol 1992 Oct
PMID:Six strains of human immunodeficiency virus type 1 isolated in Japan and their molecular phylogeny. 140 18

The restriction-modification system, named RMMunI, has been purified and characterised from Friend murine erythroleukemia cells. The site-specific endonuclease recognizes and cleaves the 5'C1AATTG nucleotide sequence. RMunI is an isoschizomer of RMfeI from Mycoplasma fermentans. Site-specific methylase modifies the second adenine residue in the same sequence (5'Cam6ATTG). It was established that the discovered enzymatic system is from mycoplasma which contaminates cell lines. Mycoplasma's DNA hybridizes with species-specific DNA probed for Mycoplasma fermentans and Mycoplasma arginini. The possible role of mycoplasmic restriction-modification enzymes in the process of acquired immune deficiency syndrome are discussed.
Mol Biol (Mosk)
PMID:[Mycoplasma restriction-modification system MunI and its possible role in pathogenesis processes]. 140 10

Specificity of anti-p25 antibodies produced against either whole Human Immunodeficiency Virus type 1 (HIV-1) particles in humans and chimpanzees, or against soluble forms of the protein in chimpanzees and rabbits was analyzed by ELISA using a panel of 37 long (> or = 30 residues) or shorter (9-21 residues) overlapping peptides covering the entire p25 sequence. Antibodies elicited by intact virions presented similar reactivity patterns in HIV-1-infected humans and in HIV-1-infected or immunized chimpanzees and recognized only a limited region mostly the C-terminus of the molecule. Moreover, 8 of the human sera (36%), which nonetheless reacted with high titers and avidity with native p25, did not bind to any long or short peptide. These results suggest that the majority of antibodies elicited by viral particles are presumably directed to conformational epitopes. In contrast, antibodies raised against soluble forms of p25 could react against all long peptides but one (residues 211-245) and against some short peptides, indicating that most of p25 sequence may be immunogenic under these conditions. These results suggest that the reactivity spectrum of anti p25 antibodies is rather different if they are produced against intact HIV-1 particles or the soluble protein. They also indicate that it may be possible to manipulate the specificity of the humoral immune response by using either intact virions or purified proteins.
Mol Immunol 1992 Nov
PMID:Specificity of anti-P25 antibodies produced against whole HIV-1 particles or soluble forms of the protein. 140 19

Disseminated Mycobacterium avium/Mycobacterium intracellulare complex (MAC) disease is a frequent complication in patients with the acquired immune deficiency syndrome (AIDS). In this report, we present the nucleotide sequence of the M. intracellulare MI22 gene. Computer sequence comparisons reveal that the MI22 gene, which encodes a serologically active protein, has 78% DNA sequence identity and 77% protein sequence identity with the seroreactive 19 kDa Mycobacterium tuberculosis lipoprotein antigen. Southern blot hybridizations indicate that an MI22 gene probe binds similar-sized restriction fragments in M. tuberculosis and M. intracellular genomic DNA. In addition, immunoblot analyses demonstrate that MI22 is recognized by sera from tuberculosis patients. These data further support the existence of 19 kDa MAC and M. tuberculosis protein homologues. Phase partitioning experiments and the presence of a consensus lipid modification site in the deduced MI22 protein sequence strongly suggest that M122 is also a lipoprotein. Comparative analyses of these mycobacterial antigenic homologues may provide the basis for the design of species-specific diagnostic reagents.
Mol Microbiol 1992 Jun
PMID:Nucleotide sequence analysis and serologic characterization of the Mycobacterium intracellulare homologue of the Mycobacterium tuberculosis 19 kDa antigen. 144 68

In our search for therapeutic agents from natural sources with potential for the treatment of opportunistic infections in patients afflicted with acquired immunodeficiency syndrome (AIDS), we investigated antibacterial and antifungal activities of water extracts of Cassia alata (C. alata). The extracts are traditionally used in Ivory Coast, West Africa to treat bacterial infections caused by Escherichia coli (E. coli), and fungal infections caused by Candida albicans (C. albicans) and dermatophytes. Our working hypothesis was that the extract contains active ingredient(s) which can be isolated, identified and developed into useful antimicrobial/antifungal agents for the treatment of opportunistic infections in patients with AIDS. We used the broth dilution and agar dilution methods. Specifically, we focused on E. coli and C. albicans and the effectiveness of the extracts was evaluated relative to those of standard antibacterial agent chloramphenicol and antifungal agent amphotericin B. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) for the water extract of C. alata against E. coli were 1.6 mg/ml and 60 mg/ml respectively; corresponding data for chloramphenicol were 2 ug/ml. Similarly, the MIC and minimum fungicidal concentration (MFC) for the extract against C. albicans were 0.39 mg/ml and 60 mg/ml in contrast to 0.58 ug/ml and 0.98 ug/ml for amphotericin B. From the dose-response curve plots, the extract had an IC50 of 31 mg/ml for E. coli and 28 mg/ml for C. albicans. The data suggest that C. alata extracts contain agent(s) which have therapeutic potential and might be useful if isolated and developed for the treatment of opportunistic infections of AIDS patients.
Cell Mol Biol 1992 Aug
PMID:Cassia alata and the preclinical search for therapeutic agents for the treatment of opportunistic infections in AIDS patients. 146 10

In our search for therapeutic agents from natural sources with potential for the treatment of opportunistic infections in patients afflicted with acquired immunodeficiency syndrome (AIDS), we investigated antibacterial and antifungal activities of water extracts of Cassia alata (C. alata). The extracts are traditionally used in Ivory Coast, West Africa to treat bacterial infections caused by Escherichia coli (E. coli), and fungal infections caused by Candida albicans (C. albicans) and dermatophytes. Our working hypothesis was that the extract contains active ingredient(s) which can be isolated, identified and developed into useful antibacterial/antifungal agents for the treatment of opportunistic infections in patients with AIDS. We used the broth dilution and agar dilution methods. Specifically, we focused on E. coli and C. albicans and the effectiveness of the extracts was evaluated relative to those of standard antibacterial agent chloramphenicol and antifungal agent amphotericin B. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) for the water extract of C. alata against E. coli were 1.6 mg/ml and 60 mg/ml, respectively; corresponding data for chloramphenicol were 2 micrograms/ml and 10 micrograms/ml. Similarly, the MIC and minimum fungicidal concentration (MFC) for the extract against C. albicans were 0.39 mg/ml and 60 mg/ml in contrast to 0.58 micrograms/ml and 0.98 micrograms/ml for amphotericin B. From the dose-response curve plots, the extract had an IC50 of 31 mg/ml for E. coli and 28 mg/ml for C. albicans. The data suggest that C. alata extracts contain agent(s) which have therapeutic potential and might be useful if isolated and developed for the treatment of opportunistic infections of AIDS patients.
Cell Mol Biol (Noisy-le-grand) 1992 Nov
PMID:Cassia alata and the preclinical search for therapeutic agents for the treatment of opportunistic infections in AIDS patients. 147 6

An improved protocol for PCR analysis of Mycobacterium leprae-infected tissues, based on enzymatic lysis, has been developed and used to demonstrate the feasibility of using PCR for detecting M. leprae in routine skin biopsies taken from leprosy patients throughout the clinical spectrum. Of 92 multibacillary patients tested, 99% were PCR-positive using gel electrophoresis or DNA hybridization to detect the amplified product. Similar analysis of paucibacillary patients, in which only one of 27 biopsies had demonstrable AFB microscopically, gave a positivity rate of 74%. No PCR signals were demonstrated from skin biopsies from seven patients with non-leprosy dermatoses and one AIDS patient with a disseminated atypical mycobacteriosis. Evaluation of leprosy patients with antileprosy drug therapy prior to biopsy demonstrated that PCR signals were either greatly diminished or absent after 2 months of continuous antibiotic therapy. PCR was also able to detect the presence of M. leprae in tissues of patients receiving antibacterial therapy when patients were suspected of harbouring drug-resistant M. leprae.
Mol Cell Probes 1992 Oct
PMID:Detection of Mycobacterium leprae and the potential for monitoring antileprosy drug therapy directly from skin biopsies by PCR. 147 78


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