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)

A reverse transcriptase PCR was developed to detect 50 or 5,000 RNA copies of influenza A virus per ml in throat swab specimens. The assay was more sensitive than the Directigen Flu A test. The technique was also used to detect amantadine-resistant isolates.
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PMID:Utility of reverse transcriptase PCR for rapid diagnosis of influenza a virus infection and detection of amantadine-resistant influenza a virus isolates. 1518 74

Proinflammatory cytokines, including tumor necrosis factor (TNF)alpha, have been recognized as important physiopathogenetic factors in the initiation and continuation of inflammatory cardiomyopathies. Experimental and preliminary human studies have demonstrated that TNFalpha plays a crucial role in enteroviral-induced myocarditis. In this study, we investigated the expression of TNFalpha and both its receptors (TNFRI and TNFRII) in both viral and nonviral myocarditis. Myocardial expression of TNFalpha was then correlated with different clinical and pathologic findings. TNFalpha expression was investigated in endomyocardial biopsies obtained from 38 patients with myocarditis and from eight control subjects by using reverse transcriptase-polymerase chain reaction (PCR) and immunohistochemistry. Viral etiology was diagnosed by PCR in 20 cases: enterovirus in seven, Epstein-Barr virus in four, hepatitis C virus in three, adenovirus in two, influenza virus in two, cytomegalovirus in one, and double infection adenovirus and enterovirus in one. Immunohistochemistry was also used to analyze both TNFalpha receptors (RI and RII). A semiquantitative analysis was employed (score 0-3) for necrosis, inflammation, fibrosis and immunohistochemical findings. TNFalpha mRNA and TNFalpha protein were significantly more present in viral myocarditis than in nonviral myocarditis (16/20 vs 3/18, P=0.001). Remarkable immunostaining was observed for both receptors, particularly TNFRI. Histological analysis revealed that myocardial necrosis (mean score 1.89 vs 1.15, P=0.01) and cellular infiltration (mean score 2.26 vs 1.78, P=0.05) were more prominent in TNFalpha-positive cases. Among TNFalpha-positive cases, the greater TNFalpha mRNAs, the more impaired was cardiac function. Our findings suggest that the expression of TNFalpha may play an important role in the pathogenesis of viral myocarditis of any etiology and may influence the severity of cardiac dysfunction. Cytokine effects are more strictly linked to overexpression of TNFRI.
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PMID:Overexpression of tumor necrosis factor (TNF)alpha and TNFalpha receptor I in human viral myocarditis: clinicopathologic correlations. 1521 6

Surfactant protein D (SP-D) is a collagenous calcium-dependent lectin constitutively expressed by alveolar type II pneumocytes and non-ciliated bronchiolar epithelial (Clara) cells. It binds to surface glycoconjugates expressed by a wide variety of microorganisms such as Gram-negative bacteria, influenza A virus, and various fungi, leading to pathogen inactivation or enhanced neutrophil and macrophage activity. Since a hallmark of bronchopneumonia is the initiation of inflammation in the bronchi and bronchoalveolar junction, we chose a classic ruminant model of bronchopneumonia caused by Mannheimia haemolytica to study the expression of SP-D within the bronchioles of infected lambs. Healthy weaned lambs were inoculated with either pyrogen-free saline (controls) or M. haemolytica intrabronchially using a fiber-optic bronchoscope. SP-D protein and mRNA expression in lung was detected by immunohistochemistry (IHC) and fluorogenic real-time relative quantitative reverse transcriptase polymerase chain reaction (real-time RT-PCR), respectively, during acute (1 day), subacute (15 days), and chronic (45 days) bronchopneumonia. At 15 and 45 days post-inoculation, areas of lung had peribronchiolar inflammatory cell infiltrate, epithelial cell hyperplasia, tortuosity of the airway lumens, and decreased intensity of SP-D protein staining and number of positive cells. The levels of SP-D mRNA were not increased or significantly altered by M. haemolytica infection when compared to control animals. In conclusion, cell-associated SP-D protein expression significantly decreases within hyperplastic epithelium of lungs from infected animals during chronic bronchopneumonia. Exhaustion of SP-D protein reserves and absence of SP-D gene upregulation during the progression of bacterial pneumonia into chronicity may result in failure to clear the pathogen from the lung and/or cause animals to be more susceptible to re-infection.
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PMID:Surfactant protein D expression in normal and pneumonic ovine lung. 1535 Jul 53

The present paper reports of the comparison between three rapid virus detection systems and virus isolation (VI) from pooled tracheal swabs collected from naturally and experimentally infected birds with a low pathogenicity avian influenza virus of the H7N3 subtype. The relative sensitivity, specificity and agreement (K value) were calculated for a commercial antigen capture enzyme immunoassay (AC-EIA) and for two nucleic acid detection tests, a one-step reverse transcriptase-polymerase chain reaction (RT-PCR) and a real-time RT-PCR (RRT-PCR), both targeting the M gene. The results indicate that in experimentally infected turkeys VI was positive from the pooled tracheal swabs collected from day 3 to day 10. One-step RT-PCR was able to detect influenza RNA from samples collected from day 3 to day 12, while RRT-PCR amplified influenza RNA in swabs collected from day 3 to day 15. The AC-EIA test yielded positive results between day 5 and day 10 post-infection. On field samples, the K value between the AC-EIA and VI tests was 0.82. Compared with VI, the relative sensitivity of this test was 88.9% (CI95 = 85.2-92.6) and the relative specificity was 95.7% (CI95 = 93.7-97.7). The K value between the RT-PCR and VI tests was 0.88. Compared with virus isolation, the relative sensitivity of the one-step RT-PCR was 95.6% (CI95 = 93.1-98.0) and the relative specificity was 96.3% (CI95 = 94.4-98.1). The K value between the RRT-PCR and VI tests was 0.92. Compared with virus isolation, the relative sensitivity and specificity of RRT-PCR was 93.3% (CI95 = 90.4-96.3) and 98.4% (CI95 = 97.2-99.6), respectively. Generally speaking, comparison between virus isolation, the AC-EIA test and the two nucleic acid detection methods indicated excellent agreement. Data obtained from both experimental and field study suggest a higher sensitivity of the PCR-based methods compared with the AC-EIA. The economical and practical implications of using one of the rapid tests as an alternative to VI during an avian influenza epidemic are discussed.
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PMID:Comparison of three rapid detection systems for type A influenza virus on tracheal swabs of experimentally and naturally infected birds. 1537 41

In February 2003, the highly pathogenic avian influenza-A virus, subtype H7N7, was the causative agent of a large outbreak of fowl plague in the Netherlands. Two days after visiting a poultry farm that was infected by fowl plague, a 57-year-old male veterinarian developed malaise, headache and fever. After 8 days he was admitted to hospital with signs of pneumonia. Five days later, his condition deteriorated alarmingly. Despite extensive pharmacotherapy he died 4 days later of acute pneumonia. Influenza-A virus, subtype H7N7, was identified by means of reverse transcriptase/PCR in broncho-alveolar washings that had been obtained earlier; routine virus culture yielded the isolate A/Nederland/219/03, which differs by 14 amino-acid substitutions from the first isolate in a chicken (A/kip/Nederland/1/03). Partly as a result of this case, the preventive measures were then adjusted; people who came into contact with infected poultry were given increased possibilities for vaccination and the administration of oseltamivir.
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PMID:[A fatal infection due to avian influenza-A (H7N7) virus and adjustment of the preventive measures]. 1555 15

The search for inhibitors of viral replication is dependent on understanding the events taking place at the molecular level during viral infection. All the essential steps during the viral life cycle are potential targets for antiviral drugs. Classical inhibitors of herpesvirus replication cause chain termination during viral DNA replication. Similarly, the HIV reverse transcriptase is the major target of anti-HIV compounds. The broad-spectrum antiviral agent ribavirin affects viral nucleic acid replication by multiple mechanisms. Another major enzyme encoded by many viruses is a protease responsible for the processing of virus-encoded polyproteins. The HIV protease has been very successfully targeted, and hepatitis C virus and rhinovirus protease inhibitors are being actively developed. The complex series of interactions during virus entry is a rapidly emerging and promising target for inhibitors of HIV and many other viruses. New anti-influenza drugs inhibit virus release from infected cells. Several stages of the viral life cycle remain incompletely characterized and are therefore poorly exploited in antiviral strategies. These include, among others, the RNA capping reactions catalyzed by many viruses, as well as the membrane association of replication complexes which is common to all positive-strand RNA viruses.
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PMID:Inhibitors of virus replication: recent developments and prospects. 1559 28

Since the role of respiratory viruses in lung exacerbations of patients with cystic fibrosis has been hampered by the difficulty of detecting viruses in viscous sputum specimens, a multiplex reverse transcriptase PCR (RT-PCR) assay combined with colorimetric amplicon detection was tested for the identification of seven common respiratory viruses in the sputa of cystic fibrosis patients. Of 52 sputa from 38 patients, 12 (23%) samples from 12 patients were positive for a respiratory virus (4 for influenza B, 3 for parainfluenza 1, 3 for influenza A and 2 for respiratory syncytial virus). These results suggest that the RT-PCR method carried out on sputum may provide a convenient means of investigating the role of virus infection in lung exacerbations of cystic fibrosis patients.
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PMID:Method for detection of respiratory viruses in the sputa of patients with cystic fibrosis. 1561 37

Proficiency assessments are important elements in quality control for diagnostic laboratories. Traditionally, proficiency testing for polymerase chain reaction (PCR)-based assays has involved the use of clinical samples, samples "spiked" with live agents or DNA plasmids. Because of government regulations and biosecurity concerns, distribution of live high-consequence pathogens of livestock and poultry, such as avian influenza, is not possible, and DNA plasmids are not technically suitable for evaluating RNA virus detection. Therefore, a proficiency testing panel using whole avian influenza in a diluent containing a phenolic disinfectant that inactivates the virus while preserving the RNA for at least 8 weeks at -70 C was developed and used in a multicenter proficiency assessment for a type A influenza real-time reverse transcriptase (RT)-PCR test. The test, which was highly standardized, except for variation in the real-time RT-PCR equipment used, was shown to be highly reproducible by proficiency testing in 12 laboratories in the United States, Canada, and Hong Kong. Variation in cycle threshold values among 35 data sets and 490 samples was minimal (CV = 5.19%), and sample identifications were highly accurate (96.7% correct identifications) regardless of real-time PCR instrumentation.
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PMID:Use of a novel virus inactivation method for a multicenter avian influenza real-time reverse transcriptase-polymerase chain reaction proficiency study. 1569 Sep 58

The ability to rapidly diagnose influenza virus infections is of the utmost importance in the evaluation of patients with upper respiratory tract infections. It is also important for the influenza surveillance activities performed by national influenza centers. In the present study we modified a multiplex real-time reverse transcriptase PCR (RT-PCR) assay (which uses TaqMan chemistry) and evaluated it for its ability to detect and concomitantly differentiate influenza viruses A and B in 370 patient samples collected during the 2001-2002 influenza season in Israel. The performance of the TaqMan assay was compared to those of a multiplex one-step RT-PCR with gel detection, a shell vial immunofluorescence assay, and virus isolation in tissue culture. The TaqMan assay had an excellent sensitivity for the detection of influenza viruses compared to that of tissue culture. The overall sensitivity and specificity of the TaqMan assay compared to the results of culture were 98.4 and 85.5%, respectively. The sensitivity and specificity of the TaqMan assay for the detection of influenza virus A alone were 100 and 91.1%, respectively. On the other hand, the sensitivity and specificity for the detection of influenza virus B alone were 95.7 and 98.7%, respectively. The rapid turnaround time for the performance of the TaqMan assay (4.5 h) and the relatively low direct cost encourage the routine use of this assay in place of tissue culture. We conclude that the multiplex TaqMan assay is highly suitable for the rapid diagnosis of influenza virus infections both in well-established molecular biology laboratories and in reference clinical laboratories.
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PMID:Evaluation of a multiplex real-time reverse transcriptase PCR assay for detection and differentiation of influenza viruses A and B during the 2001-2002 influenza season in Israel. 1569 50

Treating Hepatitis C among HIV patients under antiretroviral drug therapy requires a high degree of vigilance and continuous monitoring because of frequent problems with intolerance and/or drug interactions. Recent studies, including three therapeutic trials, on Ribavic, APRICOT, and ACTG A5671, have given some insights on following these patients up. The adverse effects are relatively similar in HCV-HIV-co-infected patients and patients infected by HCV only. Their frequency is, on the other hand, higher among HCV-HIV-Co-infected patients. The adverse-effects are consistent, in a non-exhaustive way, with pseudo influenza-like symptoms, fever, myalgia, cephalgia, with psychiatric disorders (irritability, depression, etc.); endocrine disorders (thyroid dysfunction, diabetes...); and with hematological anomalies especially anemia and leucopenia. But the percentage of lymphocyte T CD4 is not modified, therefore there is no risk of opportunistic infection. Pharmacokinetic interactions between antiretroviral drugs and treatment for HCV infection including ribavirin plus interferon alpha (IFN-alpha) or pegylated IFN are described. They are almost exclusively due to the combination of ribavirin and of nucleoside analogue reverse transcriptase inhibitors. One of the principal consequences is the emergence of mitochondrial toxicity defined by the occurrence of hyperlactatemia, or acute pancreatitis). Thus, some combinations should be avoided such as ddI+ribavirin and ddI+d4T+ribavirin. The d4T+ribavirin combination must also be used with caution.
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PMID:[Intolerance to and/or drug interactions of anti-HIV and anti-HVC therapy]. 1591 Nov 83


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