Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.7.49 (reverse transcriptase)
 31,746 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To determine whether there was a correlation between the kinetics or frequency of antibody to mammalian-derived hepatitis C virus (HCV) second envelope protein (E2) and development of chronicity or self-limitation of HCV infections, serial sera were examined for anti-E2, anti-HCV with confirmation with Matrix 2.0 (Abbott Laboratories, Abbott Park, IL), and reverse transcriptase-polymerase chain reaction (RT-PCR) from 6 cases of self-limited infection and 6 cases of chronic infection in chimpanzees, and from 5 cases of self-limited infection and 3 cases of chronic infection in patients. Anti-E2 developed earlier, more frequently, and to higher titer in chimpanzees and patients who were developing chronic infection than in those with self-limited infections. Thus anti-E2 is unlikely to play a role in self-limitation of the infection. However, long-term persistence of anti-E2 correlates with chronic infection. There was little or no correlation between the timing of development of anti-E2 and anti-HCV.
 ...
PMID:Significance of the anti-E2 response in self-limited and chronic hepatitis C virus infections in chimpanzees and in humans. 1047 22

The Hexaplex assay (Prodesse, Inc., Milwaukee, Wis.) is a multiplex reverse transcriptase (RT)-PCR assay for the detection of parainfluenza virus types 1, 2, and 3, respiratory syncytial virus (RSV) types A and B, and influenza virus types A and B. We evaluated the Hexaplex assay in comparison with conventional viral cell cultures and rapid enzyme immunoassays (EIAs) for RSV (Directigen; Becton Dickinson Inc., Cockeysville, Md.) and influenza A virus (Abbott Test Pack; Abbott Laboratories, Abbott Park, Ill.) for the detection of respiratory viruses from pediatric respiratory specimens obtained from children seen at Children's Hospital of Wisconsin from December 1997 through May 1998. A total of 363 respiratory specimens were evaluated. The tissue culture prevalence of parainfluenza virus during this period of time was low (1.1%). The sensitivity, specificity, and positive and negative predictive value of Hexaplex compared to tissue culture for the detection of parainfluenza virus were 100, 95.8, 19.0, and 100%, respectively. Only one specimen was determined to contain influenza B virus by Hexaplex; it was tissue culture negative. A specimen was considered to contain RSV or influenza A virus when it was either culture positive or culture negative but Hexaplex and EIA positive. Prior to the analysis of discrepant results, the sensitivity, specificity, and positive and negative predictive value for the detection of RSV were 91.2, 100, 100, and 98.0%, respectively, for tissue culture; 84.5, 100, 100, and 96.6% for EIA; and 98.5, 91.5, 72.8, and 99.6% for Hexaplex, respectively. The sensitivity, specificity, and positive and negative predictive value for the detection of influenza A virus prior to the analysis of discrepant results were 100, 100, 100, and 100%, respectively, for culture, 78.0, 100, 100, and 89.4% for EIA, respectively, and 95.1, 94.1, 67.2, and 99.3% for Hexaplex, respectively. Culture- and/or EIA-negative, Hexaplex-positive specimens were analyzed by a second RT-PCR assay which used primers specific for a different genomic region than that used in the Hexaplex assay. After analysis of these discrepant results, the sensitivity, specificity, and positive and negative predictive value for the detection of RSV were 74.3, 100, 100, and 93.5%, respectively, for tissue culture; 70.3, 100, 100, and 92.5% for EIA; and 98.6, 97.4, 91.2, and 99.6% for Hexaplex. The sensitivity, specificity, and positive and negative predictive value for the detection of influenza A virus were 83.3, 100, 100, and 97.4%, respectively, for tissue culture; 69.4, 100, 100, and 83.3% for EIA; and 95.8, 98.7, 92.0, and 99.3% for Hexaplex. Hexaplex is a rapid, sensitive, and specific method for the detection of the seven most common respiratory viruses in children.
 ...
PMID:Evaluation of the Hexaplex assay for detection of respiratory viruses in children. 1132 76

Drug resistance, the biggest problem facing medicine today, has caused recent views of anti-HIV therapies to be pessimistic. Resistance arises in HIV due to an evolutionary process involving mutations, which are passed on to viral offspring. Continuous use of antiviral agents, such as AZT, in combination with the slow course of the disease, provides time for the virus to evolve and become more resistant. There is dispute over the level of cross-resistance (how resistance to one drug affects the action of another drug). Non-nucleoside analog reverse transcriptase inhibitors (RTI's) are more prone to becoming ineffective compared to other classes of anti-HIV drugs since RTI's, while significantly reducing blood viral load, still allow enough virus to survive, thus encouraging resistance to develop. Some evidence suggests that the inhibitors MK-639, saquinavir, and the Abbott inhibitor, can be combined with each other in order to achieve greater reductions in the viral load. Merck reports, however, that a year's treatment with MK-639 has created a virus that is resistant to all protease inhibitors thus far tested. Clinical trials, designed to find other anti-HIV drugs and to avoid resistance, are beginning soon.
 ...
PMID:Resistance: how HIV evolves to survive. 1136 38

A controversy has developed, initiated by a paper in the April 1995 issue of Nature, over the use of protease inhibitors among AIDS patients. The article, written by Jon Condra and Emilio Emini, reported that HIV developed resistance to indinavir (Merck & Co.'s protease inhibitor), and all other protease inhibitors as well. In response to the study on Merck's product, Roche released information suggesting that their protease inhibitor, saquinavir, does not cause resistance nearly as quickly or as much. Merck is currently studying the combination of indinavir and AZT, and Abbott Laboratories is examining the effects of AZT, ddC, and ritonavir. These studies imply that optimal multi-drug combination therapy should delay drug resistance as well as cross-resistance. The implications are promising for patients with HIV and AIDS. Pharmaceutical companies are conducting additional studies to develop new reverse transcriptase inhibitors and to determine the effectiveness of the combination of two or more protease inhibitors. Each drug trial demonstrates the relationship between dosing and resistance; patients are advised to adhere completely to dosing instructions.
 ...
PMID:Protease inhibitors and prevention of cross resistance. 1136 75

A new generation of protease inhibitors is entering studies. Abbott Lab's ABT-378 and Pharmacia/Upjohn's PNU-140690 are beginning clinical studies and both are designed to overcome resistance problems. Several companies are developing new compounds to inhibit reverse transcriptase, such as Bristol-Myers Squibb's lobucavir and Hoechst/Bayer's HBY097. Calanolide A, which will soon begin trials, has a different resistance pattern than other non-nucleoside reverse transcriptase inhibitors, which may be an important advantage. Several groups are developing compounds to inhibit the HIV zinc finger, such as Parke-Davis' compound, CI-1012; and a Dutch company who is developing Azodicarbonamide, a drug currently in phase I/II trials for people with advanced disease in Europe. HIV drugs to date have not been successful in blocking viral fusion. However, three new fusion inhibitors are showing promise within the laboratory: Pentafuside (currently in phase I trials), Fuji ImmunoPharmaceuticals' FP-21399 (currently in phase I trials), and ISIS Pharmaceuticals' ISIS 5320. A new class of drugs known as integrase inhibitors has been of interest to pharmaceutical companies for the past several years; only one drug, Aronex Pharmaceuticals' Zintevir, has reached phase I/II trials.
 ...
PMID:Protease inhibitors and beyond. 1136 10

Current treatment strategies need to be planned carefully, because there is an inadequate supply of new types of drugs available to treat people who have failed previous therapies. It is important to fully use existing therapies so as not to limit future options. Drugs in development include: ABT-378, a protease inhibitor from Abbott Laboratories; tipranavir (PNU-140690), a protease inhibitor by Pharmacia & Upjohn; and S-1153, a non-nucleoside reverse transcriptase inhibitor from Agouron Pharmaceuticals. All were effective and well-tolerated in recent trials. A warning was issued for adefovir, a nucleoside reverse transcriptase inhibitor, regarding the development of kidney toxicity for people taking the drug more than 20 weeks. Information on expanded access programs for abacavir, adefovir, amprenavir, and efavirenz is provided.
 ...
PMID:New drugs in development. 1136 51

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.
 ...
PMID:Upcoming compassionate use programs for two new antiretrovirals will begin this fall. 1136 64

Abbott Laboratories has approximately 300 slots available in the expanded access program for ABT-378/ritonavir. ABT-378/ritonavir is an experimental protease inhibitor combined with a small amount of ritonavir to increase bioavailability. There is a limited supply of ABT-378/ritonavir and the drug is only available to individuals most in need. Eligibility requirements for the program are listed. All participants will continue to receive the drug until it is approved. People who meet eligibility requirements may already have developed resistance to all currently approved regimens. Other drugs may soon be available, including the fusion inhibitor, T-20, and the nucleotide reverse transcriptase inhibitor, tenofovir (PMPA). These drugs may be used to construct a new regimen, if current medications will not work. Contact information is provided.
 ...
PMID:Expanded access program for ABT-378 under way. 1136 22

By using a rapid test for respiratory syncytial virus (RSV) detection (Abbott TestPack RSV), a number of patients were observed, showing repeatedly positive results over a period of up to 10 weeks. A prospective study was initiated to compare the rapid test with an antigen capture enzyme immunoassay (EIA) and a nested reverse transcriptase PCR (RT-PCR) protocol for detection of RSV serotypes A and B. Only respiratory samples from children exhibiting the prolonged presence of RSV (> or =5 days) as determined by the rapid test were considered. A total of 134 specimens from 24 children was investigated by antigen capture EIA and nested RT-PCR. Using RT-PCR as the reference method, we determined the RSV rapid test to have a specificity of 63% and a sensitivity of 66% and the antigen capture EIA to have a specificity of 96% and a sensitivity of 69% for acute-phase samples and the homologous virus serotype A. In 7 (29%) of 24 patients, the positive results of the RSV rapid test could not be confirmed by either nested RT-PCR or antigen capture EIA. In these seven patients a variety of other respiratory viruses were detected. For general screening the RSV rapid test was found to be a reasonable tool to get quick results. However, its lack of specificity in some patients requires confirmation by additional tests to rule out false-positive results and/or detection of other respiratory viruses.
 ...
PMID:Reliable detection of respiratory syncytial virus infection in children for adequate hospital infection control management. 1152 41

Epidemiological data, especially population-based data, on respiratory syncytial virus (RSV)-related hospitalizations in Germany have been lacking to date. Since Palivizumab (Synagis, Abbott, USA) is already available and new vaccines for active immunization are under development, these data are urgently needed. From July 1996 to June 1999, nasopharyngeal aspirates of children hospitalized in Kiel with an acute respiratory tract infection were tested by multiplex reverse transcriptase polymerase chain reaction. Of 1,241 patients, 150 (12.1%) were RSV positive. RSV was the predominant pathogen detected through the end of the second year. In 37 (25%) children an underlying condition was present. For the city of Kiel and close surroundings, the cumulative incidence of RSV-positive hospitalizations in infants was 1,214/10(5) (725/10(5) in children less than 2 years). For those children less than 2 years old born with a gestational age of less than 32 weeks or 32-37 weeks, the cumulative incidence was 2,025/10(5) and 1,202/10(5), respectively (dose-effect response). For the group less than 32 weeks of age, bronchopulmonary dysplasia (BPD) as an underlying condition carried a relative risk of 17.8. The RSV season began between the end of September and January and ended between March and July. The population-based incidence of RSV-positive hospitalizations in Kiel is close to that reported from the UK and Scandinavia. Throughout Germany, approximately 10.000 RSV-related hospitalizations in infants can be expected annually. Prematurity is an effect modifier and BPD a strong risk factor for RSV-positive hospitalization in population-based studies. There is considerable variation in the start and end of the yearly epidemic.
 ...
PMID:Incidence of respiratory syncytial virus-positive hospitalizations in Germany. 1156


<< Previous 1 2 3 4 5 Next >>