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

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

Women comprise 45 percent of new HIV infections, but account for only 9 to 20 percent of clinical research participants. Hoffmann-La Roche is conducting a study to evaluate potential differences in response to antiretroviral drug therapy based on gender. The study will enroll 60 women and 20 men, all HIV-positive. It will compare the participants' responses to Saquinavir (Fortovase) in combination with two nucleoside reverse transcriptase inhibitors. Researchers will look at immunologic measures including CD4 cell count and viral suppression. The trial will also evaluate the efficacy of Saquinavir and oral contraceptives when used together. Contact information is provided.
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PMID:Study to address effects of antiretroviral therapy on women. 1136 77

This fall, ABT-378 will be available in a limited supply through Abbott Labs= compassionate use program. ABT-378 is a new protease inhibitor that may be effective in patients who have developed a resistance to other protease inhibitors, including Fortovase and Norvir. The drug will be available to 200 to 300 people with CD4 counts below 50 who do not have other treatment options. Gilead=s newest nucleotide reverse transcriptase inhibitor, PMPA, will also be available through a compassionate use program. PMPA appears to be more powerful than adefovir, PMPA's predecessor, but the potential side effects of PMPA are unknown. Contact information is provided.
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PMID:Upcoming compassionate use programs for two new antiretrovirals will begin this fall. 1136 64

A comparative study will be conducted to determine the extent to which women and men respond differently to anti-HIV treatment. The study will compare the effects of the protease inhibitor Fortavase (Saquinavir) with two nucleoside reverse transcriptase inhibitors (NRTIs). The study will examine viral suppression, CD4 cell counts, and viral levels in vaginal fluids. Additionally the interaction between Fortavase and oral contraceptives also will be analyzed. Contact information is provided.
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PMID:Do women respond differently to HIV therapy than men? 1136 87

Agouron Pharmaceuticals trial results suggest additional treatment options for people taking or considering taking Viracept in combination with other anti-HIV drugs. The clinical test results with Viracept and other drugs are presented. Viracept was tested for safety and efficacy with Fortovase (saquinavir soft gel), Norvir (ritonavir), Crixivan (indinavir), 1592 (abacavir), and non-nucleoside reverse transcriptase inhibitors.
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PMID:Protease inhibitor combos. 1136 48

HIV-1 protease inhibitors have contributed significantly to the reduction in morbidity and mortality associated with HIV-1 disease. Some of their clinical benefit may be attributed to inhibition of non-viral pathogen proteases and mammalian proteases involved in apoptosis. Our objective was to investigate the effect of HIV-1 protease inhibitors on two different mechanisms of apoptosis in cells not exposed to HIV-1. Modulation of apoptosis induced in U937 or Jurkat cells by CD95 (Fas-ligand) or TNF-alpha was measured using flow cytometry using the 7-AAD and annexin/propidium iodide methods. - HIV-1 protease inhibitors reduced TNF-alpha mediated cell death in a dose-dependent manner, with a maximum inhibition ranging between 38% and 60% observed for 100 microM indinavir. Saquinavir and ritonavir, but not nelfinavir also inhibited TNF-alpha induced cell death. Nevirapine (an HIV-1 reverse transcriptase inhibitor) showed no effect. The TNF-alpha activity was also inhibited by the caspase inhibitors Z-VAD-fmk at concentrations of 10 microM or less, and by DEVD-cmk. In contrast, HIV-1 protease inhibitors did not affect CD95 induced apoptosis in Jurkat cells at any of the concentrations tested. Our findings indicate that HIV-1 protease inhibitors may act on mammalian proteases involved in the regulation of apoptosis; whether this is relevant in the clinical setting remains to be established. Identification of the pathways involved may lead to a better understanding of the clinical impact of this drug class and their role in HAART associated toxicities.
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PMID:Inhibition of TNF-alpha mediated cell death by HIV-1 specific protease inhibitors. 1257 50

The proper implementation of combination antiretroviral treatment regimens is fundamental to successful therapeutic outcomes for patients with HIV/AIDS. Unfortunately, some patients are still being prescribed contraindicated antiretroviral regimens that include: 1. stavudine plus zidovudine; 2. Invirase plus two nucleoside analog reverse transcriptase inhibitors (NRTIS); 3. zalcitabine plus didanosine; 4. zalcitabine plus stavudine; and, 5. zalcitabine plus lamivudine. Inappropriate regimens such as these either have limited effectiveness or potential severe toxicity.
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PMID:Contraindicated antiretroviral drug combinations. 1455 2

Saquinavir hard gel capsule (hgc), the first human immunodeficiency virus (HIV) protease inhibitor (PI) used in clinical practice, has been shown to have insufficient effectiveness. A population-based cohort study assessed the long-term consequences of using saquinavir hgc as initial PI in HIV-infected patients pre-exposed to nucleoside reverse transcriptase inhibitors. 121 patients starting a regimen with saquinavir hgc were compared with 91 starting with non-boosted indinavir (n = 72) or ritonavir (n = 19). Median follow-up time was 4.6 and 4.7 y for the 2 groups. Starting with saquinavir hgc was associated with a lower overall probability of achieving an undetectable viral load [risk ratio (RR) = 0.41, 95%, confidence interval (95% CI) 0.30-0.56]. However, the lower probability of having undetectable viral load during follow-up declined over time with odds ratios (OR) = 0.27 (95%, CI 0.14-0.54), 0.35 (951% CI 0.19-0.66), 0.47 (95% CI 0.24-0.91) and 0.73 (95% CI 0.34-1.55) at 60, 120, 180 and 240 weeks, respectively, after starting HAART. Starting with saquinavir hgc was correlated with a higher risk of having the initial PI discontinued (RR = 1.89, 95% CI 1.39-2.58). The insufficient suppression of viral load in patients starting with saquinavir hgc subsided during follow-up, probably owing to the earlier discontinuation of saquinavir hcg in favour of newer and more potent HAART regimens.
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PMID:Use of the protease inhibitor saquinavir hard gel in human immunodeficiency virus-infected patients in the early period of highly active antiretroviral therapy: does it affect long-term treatment outcome? 1460 14

An accurate, sensitive, and specific reverse-phase high-performance liquid chromatography (HPLC) assay for the simultaneous quantitative determination of HIV-protease inhibitors (PIs) (indinavir, IDV; amprenavir, APV; saquinavir, SQV; nelfinavir, NFV; ritonavir, RTV; and lopinavir, LPV) and non-nucleoside reverse transcriptase inhibitors (NNRTIs) (nevirapine, NVP; delavirdine, DLV; and efavirenz, EFV) in human blood plasma is described. The method provides excellent resolution and peak shape for nine analytes through a linear gradient (36-86%) of 25% phosphate buffer (pH 4.5), 60% acetonitrile, 15% methanol, and 0.75 ml TFA, with a gradient mobile phase flow rate (0.9-1.1 ml) over 30 min run time. The optimized solid phase extraction (SPE) extraction method using (1.0 ml, 100mg BOND ELUT-C18 Varian) column provides a clean base line and high extraction efficiency using a 550 microl plasma sample. The method was validated over the range of 10-10,000 ng/ml for NVP, IDV, and SQV; 10-5000 ng/ml for EFV; 25-10000 ng/ml for APV; and 25-5000 ng/ml for DLV, NFV, RTV, and LPV. This method is accurate (average accuracies of three different concentrations ranged from 91 to 112%), and precise (within- and between-day precision measures ranged from 0.2 to 5.7% and 0.1 to 5.4%, respectively). This method is suitable for use in clinical pharmacokinetic studies as well as in therapeutic drug monitoring (TDM).
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PMID:High-performance liquid chromatography assay for the quantification of HIV protease inhibitors and non-nucleoside reverse transcriptase inhibitors in human plasma. 1513 96

The aim of this study was to evaluate the genotypic resistance profiles of HIV-1 in children failing highly active antiretroviral therapy (HAART). Forty-one children (median age = 67 months) receiving HAART were submitted to genotypic testing when virological failure was detected. cDNA was extracted from PBMCs and amplified by nested PCR for the reverse transcriptase and protease regions of the pol gene. Drug resistance genotypes were determined from DNA sequencing. According to the genotypic analysis, 12/36 (33.3%) and 6/36 (16.6%) children showed resistance and possible resistance, respectively, to ZDV; 5/36 (14%) and 4/36 (11.1%), respectively, showed resistance and possible resistance to ddI; 4/36 (11.1%) showed resistance to 3TC and D4T; and 3/36 (8.3%) showed resistance to Abacavir. A high percentage (54%) of children exhibited mutations conferring resistance to NNRTI class drugs. Respective rates of resistance and possible resistance to PIs were: RTV (12.2%, 7.3%); APV (2.4%, 12.1%); SQV(0%, 12.1%); IDV (14.6%, 4.9%), NFV (22%, 4.9%), LPV/RTV (2.4%, 12.1%). Overall, 37/41 (90%) children exhibited virus with mutations related to drug resistance, while 9% exhibited resistance to all three antiretroviral drug classes.
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PMID:Analysis of HIV- type 1 protease and reverse transcriptase in Brazilian children failing highly active antiretroviral therapy (HAART). 1572 67

We describe a 50-year-old Caucasian man with a family history of myoclonic epilepsy associated with ragged red fibers (MERRF) and a diagnosis of Human Immunodeficiency Virus (HIV). The patient had multiple risk factors for contracting HIV and was being followed in our clinic at the time of his diagnosis. Initial testing following seroconversion revealed a baseline CD4+ T-lymphocyte count of 652 x 10(6)cells/l and a HIV-1 RNA of 14,781 copies/ml. He reported exercise intolerance and had mild neurologic deficits, which worsened around the time of HIV seroconversion. These symptoms led to his subsequent diagnosis of MERRF by the detection of the A8344G point mutation in the tRNA(Lys) gene of mitochondrial DNA (mtDNA). The baseline estimated proportion of mutant genome was 39%. He showed a rapid course of HIV disease progression with a CD4+ T-lymphocyte nadir of 174 x 10(6) cells/l associated with a HIV-1 RNA of 238,178 copies/ml, within 17 months following HIV seroconversion. To avoid further mitochondrial insult, which could result from the use of a standard nucleoside reverse transcriptase inhibitor-containing regimen, a protease inhibitor regimen consisting of hard-gel saquinavir (Invirase), and lopinavir/ritonavir (Kaletra) was chosen for this patient. The patient's CD4+ T-lymphocyte count increased to 282 x 10(6)cells/l and his viral load became undetectable 7 months following the initiation of antiretroviral therapy. His neurologic symptoms did not worsen on this antiretroviral regimen. When initiating HIV therapy in individuals with metabolic myopathies related to mitochondrial dysfunction, it may be important to design an antiviral regimen that minimizes mitochondrial damage, yet effectively maintains durable viral suppression.
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PMID:HIV disease progression and limited antiretroviral treatment options for a HIV-1 infected individual with myoclonic epilepsy associated with ragged red fibers. 1612 Mar 82


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