Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

Query: EC:2.7.7.49 (reverse transcriptase)
31,746 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Human immunodeficiency virus type 1 (HIV-1) infection causes immune dysfunction. Mononuclear phagocytes (MNP) are immune effector cells against some intracellular pathogens and reservoirs for HIV-1. This study determined effects of HIV-1 on MNP-mediated antifungal function. MNP from seronegative volunteers were inoculated with HIVBal or HIVIIIB. MNP were infected with an avirulent clone of Cryptococcus neoformans; 48 h later, MNP were lysed and yeasts were counted. Viral replication was determined by reverse transcriptase and by visualization of cytopathic effects. Monocytes and peritoneal macrophages exhibited reduced anticryptococcal activity 14 days after infection with HIVBal but retained normal activity when infected with HIVIIIB. Loss of anticryptococcal activity correlated with viral replication. Alveolar macrophages retained normal anticryptococcal activity whether infected with HIVBal or HIVIIIB. In vitro MNP-mediated antifungal activity may be altered by HIV-1 infection; this altered activity appears to depend on viral tropism, viral replication, and MNP tissue origin.
...
PMID:Human immunodeficiency virus (HIV)-infected human blood monocytes and peritoneal macrophages have reduced anticryptococcal activity whereas HIV-infected alveolar macrophages retain normal activity. 801 21

The synthesis as well as the antimicrobial and antiviral activities of new (N-heteroaryl)arylmethanamines and their Schiff bases are reported. None of the tested compounds shown activity against Herpes simplex virus type 2 and against Gram positive and Gram negative bacteria. Weak or moderate activity on poliovirus Sabin type 1, on reverse transcriptase and against Cryptococcus neoformans was shown by some of the tested compounds. Viceversa several synthesized compounds exhibited a moderate or good activity against strains of Candida albicans, while only some of the tested compounds were found moderately active against strains of Candida sp. Instead numerous new compounds 3 or 4 were active as control against isolates of plant pathogenic fungi. The obtained results are discussed on the basis of structure-activity relationships.
...
PMID:Synthesis and microbiological evaluations of (N-heteroaryl) arylmethanamines and their Schiff bases. 898 54

CneMDR1, a gene encoding a protein related to several eukaryotic multidrug resistance (MDR) proteins, was identified, cloned, and characterized from a clinical isolate of Cryptococcus neoformans (Cn) (strain M1-106). Polymerase chain reaction (PCR) amplification of a DNA region encompassing conserved motifs of other MDR-like proteins was initially used to identify and clone CneMDR1. Analysis of the corresponding cDNA revealed an open reading frame punctuated by 16 introns. CneMDR1 encoded a protein (CNEMDR1) containing 1408 amino acids (aa) with a predicted mass of approximately 152kDa. Protein structure predictions suggested the presence of two putative 6-transmembrane (TM) domains as well as two ATP-binding domains, structural characteristics typical of ATP-binding cassette (ABC) proteins. Members of this superfamily, which include MDR proteins, are frequently involved in active transport of a variety of substrates across the cell membrane. Pulsed-field gel electrophoresis revealed the presence of 12 chromosomal bands in this clinical isolate of Cn. CneMDR1 was detected by hybridization on chromosome IV. High-stringency hybridization detected only one MDR-like gene. However, a second MDR-like gene (CneMDR2) was discovered during reverse transcriptase-PCR (RT-PCR) amplification using cDNA.
...
PMID:Cloning and characterization of CneMDR1: a Cryptococcus neoformans gene encoding a protein related to multidrug resistance proteins. 940 67

Inducible nitric oxide synthase (iNOS) is required in immune response against infections and is involved in granuloma formation in animals; in murine macrophages, iNOS is induced by lipopolysaccharide and interferon-gamma. In contrast, the role of iNOS in human immune response against infections is still questioned, and its expression in granulomas is poorly investigated. Using Western blotting and immunohistochemistry, we investigated iNOS expression in human lymph nodes with nonspecific reactions and in tissues containing granulomas caused by mycobacteria, Toxoplasma, Cryptococcus neoformans, Leishmania, Bartonella, noninfectious granulomas (sarcoidosis, foreign body), and other hystiocitic reactions (Kikuchi's disease, Omenn syndrome). iNOS was undetectable in nonspecific reactive lymphadenitis, foreign-body granulomas, and Omenn syndrome, whereas it was strongly expressed in infectious granulomas, sarcoidosis, and Kikuchi's diseases. Immunohistochemistry demonstrated that iNOS was selectively expressed by the epithelioid and multinucleated giant cells within the granulomas. Use of an anti-nitrotyrosine antibody, recognizing nitrosilated amino acid residues derived from nitric oxide production, revealed a consistent positivity within the cells expressing iNOS, thus suggesting that iNOS is functionally active. Detection of cytokines by reverse transcriptase-polymerase chain reaction demonstrated that tissues that were positive for iNOS, also expressed the Thl-type cytokine interferon-gamma mRNA, but not the Th2-type cytokine interleukin-4. Taken together, these results indicate that iNOS is involved in different human immune reactions characterized by histiocytic/granulomatous inflammation and associated with Th1-type cytokine secretion.
...
PMID:Expression of inducible nitric oxide synthase in human granulomas and histiocytic reactions. 991 29

We have recently demonstrated that IL-12 induced cellular inflammatory responses consisting mainly of accumulation of mononuclear leucocytes in the lungs of mice infected with Cryptococcus neoformans and protected mice against fulminant infection. We examined the involvement of endogenously synthesized IFN-gamma in such a response by investigating the effects of a neutralizing monoclonal antibody against this cytokine. The latter treatment completely abrogated the positive effects of IL-12 on survival of infected mice and prevented IL-12-induced elimination of microbials from the lungs. Histopathological examination showed that accumulation of mononuclear leucocytes in the infected lungs caused by IL-12 was clearly inhibited by anti-IFN-gamma MoAb. We also examined the local production of mononuclear cell-attracting chemokines such as monocyte chemotactic protein-1 (MCP-1), regulated upon activation, normal T cell expressed and secreted (RANTES), macrophage inflammatory protein-1alpha (MIP-1alpha), MIP-1beta and IFN-gamma-inducible protein 10 (IP-10) in the lungs using a reverse transcriptase-polymerase chain reaction (RT-PCR) method. We found that these chemokines were not synthesized in the infected lungs, while IL-12 treatment markedly induced their production. Interestingly, neutralizing anti-IFN-gamma MoAb strongly suppressed IL-12-induced production of these chemokines. Similar results were obtained with MCP-1 and MIP-1alpha when their synthesis was measured at the protein level using respective ELISA kits. Our results indicate that IFN-gamma plays a central role in the protective effects of IL-12 by inducing mononuclear leucocyte-attracting chemokines and cellular inflammatory responses.
...
PMID:Interferon-gamma (IFN-gamma)-dependent protection and synthesis of chemoattractants for mononuclear leucocytes caused by IL-12 in the lungs of mice infected with Cryptococcus neoformans. 1040 24

The opportunistic fungal pathogen, Cryptococcus neoformans, shows a marked predilection for the central nervous system (CNS). This can be partially explained by its ability to synthesize melanin starting from the catecholamines, highly concentrated at the CNS level. Two cryptococcal strains, the avirulent non-melanogenic strain Sb26 and the virulent melanogenic revertant strain Sb26Rev, were used in a murine model of intracerebral (i.c.) infection, in order to evaluate their virulence and immunomodulating properties at the cerebral level. We found that, unlike Sb26Rev, Sb26 i.c. infection was never lethal regardless of the challenging dose. Sb26Rev infection resulted in massive CNS tissue damage, associated with little or no cytokine response, as established by semi-quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA). Differently, Sb26 infection failed to alter CNS structure, while inducing IL-12 p40, TNF-alpha, IL-1beta, IFN-gamma and iNOS specific-gene expression as well as IL-12, TNF-alpha and IL-1beta cytokine production. Interestingly, all Sb26 infected mice survived a subsequent lethal challenge with Sb26Rev. The phenomenon was associated with enhanced IL-12, TNF-alpha and IL-1beta production and was strictly specific, as shown by heterologous challenges and delayed type of hypersensitivity assay. Overall, we provide evidence that protective immunity against cerebral cryptococcosis is established by means of an avirulent strain of C. neoformans.
...
PMID:Establishment of protective immunity against cerebral cryptococcosis by means of an avirulent, non melanogenic Cryptococcus neoformans strain. 1099 9

Suppression subtractive hybridization analysis in our laboratory recently revealed that transferrin mRNA may be elevated in Sedeficient rat liver. In this work, we compared expression in rat liver of genes for transferrin, transferrin receptor, ferritin light and heavy chains, and iron-regulatory proteins 1 and 2 in Se adequacy and deficiency. Weanling male Sprague-Dawley rats were fed Torula yeast diets supplemented with 0 or 0.15 microg Se/kg diet as sodium selenite for 15 wk. Activity of cellular glutathione peroxidase was virtually abolished in Se-deficient rat liver, whereas activity of glutathione S-transferase was 43% higher than in Se-adequate liver. There were no differences in hematocrit, hemoglobin, or liver iron content. To examine differential gene expression, we used a multiplex relative reverse transcriptase-polymerase chain reaction method. Three of the six genes examined showed modest but consistent upregulation in Se deficiency. Transferrin mRNA was 30% more abundant in Se-deficient than in Se-adequate liver. For the transferrin receptor, the difference was 32%, and for iron regulatory protein 1, it was 63%. No consistent differences were observed for iron regulatory protein 2 or for ferritin light or heavy chain. These findings suggest a possible role for dietary Se in moderating iron metabolism.
...
PMID:Selenium regulates expression in rat liver of genes for proteins involved in iron metabolism. 1104

Postmortem neuropathologic reports for a consecutive series of 436 HIV-seropositive patients who died between 1985 and 1999 were matched with clinical data for 371 of them. Cases were divided into four groups depending on the date of death. The chosen time periods reflected the type of antiretroviral therapy available: before 1987 (before zidovudine); 1987-1992, the period of monotherapy (nucleoside analog reverse transcriptase inhibitors [NRTIs]); 1993-1995, the era of the use of dual NRTI combinations; and 1996-1999, the era of highly active antiretroviral therapy (HAART) containing protease inhibitors. Fifty-seven percent of our cases in this group had been prescribed HAART. In our study population, accessibility to the latest antiretroviral therapy was widespread. The total number of HIV autopsies declined after the advent of combination therapy. The prevalence of opportunistic infections-cytomegalovirus, toxoplasmosis, cryptococcosis, and central nervous system lymphoma-decreased over time. Cerebral tuberculosis, aspergillosis, herpes, and progressive multifocal leukoencephalopathy showed a downward trend, but the numbers were too low for statistical analyses. The incidence of HIV encephalopathy increased over time (p =.014). The rising prevalence of HIV encephalopathy at time of death may reflect a longer survival time after initial HIV infection in the HAART era. Although combination therapies decrease overall mortality and prevalence of CNS opportunistic infections, these therapies may be less active in preventing direct HIV-1 effects on the brain.
...
PMID:HIV-related neuropathology, 1985 to 1999: rising prevalence of HIV encephalopathy in the era of highly active antiretroviral therapy. 1239 95

The antifungal pentapeptide auristatin PHE was recently shown to interfere with microtubule dynamics and nuclear and cellular division in the opportunistic pathogen Cryptococcus neoformans. To gain a broader understanding of the cellular response of C. neoformans to auristatin PHE, mRNA differential display (DD) and reverse transcriptase PCR (RT-PCR) were applied. Examination of approximately 60% of the cell transcriptome from cells treated with 1.5 times the MIC (7.89 micro M) of auristatin PHE for 90 min revealed 29 transcript expression differences between control and drug-treated populations. Differential expression of seven of the transcripts was confirmed by RT-PCR, as was drug-dependent modulation of an additional seven transcripts by RT-PCR only. Among genes found to be differentially expressed were those encoding proteins involved in transport, cell cycle regulation, signal transduction, cell stress, DNA repair, nucleotide metabolism, and capsule production. For example, RHO1 and an open reading frame (ORF) encoding a protein with 91% similarity to the Schizophyllum commune 14-3-3 protein, both involved in cell cycle regulation, were down-regulated, as was the gene encoding the multidrug efflux pump Afr1p. An ORF encoding a protein with 57% identity to the heat shock protein HSP104 in Pleurotus sajor-caju was up-regulated. Also, three transcripts of unknown function were responsive to auristatin PHE, which may eventually contribute to the elucidation of the function of their gene products. Further study of these differentially expressed genes and expression of their corresponding proteins are warranted to evaluate how they may be involved in the mechanism of action of auristatin PHE. This information may also contribute to an explanation of the selectivity of auristatin PHE for C. neoformans. This is the first report of drug action using DD in C. neoformans.
...
PMID:Differential gene expression in auristatin PHE-treated Cryptococcus neoformans. 1474 10

The objective of the present study was to evaluate human immunodeficiency virus (HIV) levels in the aqueous humor and vitreous fluid in patients with and those without ocular involvement due to AIDS-related cryptococcosis. We also assessed whether cryptococcosis infection in the central nervous system (CNS) was associated with elevated HIV levels in the cerebrospinal fluid (CSF). From 1993 to 2003, we obtained 16 CSF samples from 9 AIDS patients with cryptococcal meningitis and 7 AIDS patients without CNS opportunistic infection. Samples of intraocular fluids were obtained from all 9 patients with cryptococcal meningitis. Five cases presented with ocular involvement in patients with meningitis. By using the method of reverse transcriptase-polymerase chain reaction, we detected higher HIV loads in aqueous humor (27,244+/-4,123 copies/ml) and vitreous fluid (84,930+/-5,071 copies/ml) in patients with concomitant CNS and ocular involvement due to AIDS-related cryptococcosis (p<0.05). HIV levels in the vitreous fluid were correlated with levels in CSF (r=0.77). Mean HIV level in the CSF (209,761+/-18,787 copies/ml) was significantly elevated in AIDS patients with cryptococcoal meningitis (p<0.05). To our knowledge, this is the first report to study the level of HIV loads in the CSF and intraocular fluid simultaneously in AIDS patients with cryptococcosis. Our results revealed the intrathecal and intraocular HIV replication in patients with cryptococcosis.
...
PMID:Detection of HIV RNA levels in intraocular and cerebrospinal fluids in patients with AIDS-related cryptococcosis. 1580 35


1 2 Next >>

---