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)

The polymerase chain reaction with prior reverse transcription of RNA into cDNA was applied to hepatitis C virus RNA detection in human serum samples of different origin. In order to eliminate false negative results, the following steps were optimized: RNA extraction, reverse transcription, and oligonucleotide primer selection. We compared different RNA extraction methods using guanidinium salt/detergent and proteinase K digestion/phenol extraction, and tested virus particle enrichment with polyethylene glycol precipitation and ultracentrifugation. RNA extraction with guanidinium salt/detergent was the most efficient method. Ultracentrifugation of single samples did not improve hepatitis C virus RNA detection. Polyethylene glycol precipitation performed poorly. Recombinant thermostable reverse transcriptase produced cDNA from fewer samples than did Moloney murine leukaemia virus reverse transcriptase. Nested oligonucleotide primers from the 5'-terminal non-coding region of the hepatitis C virus genome amplified cDNA from more samples than did primers from the coding regions. Thirty six anti-hepatitis C virus antibody positive samples were tested; nested primers (nucleotides 6 to 327 and 15 to 288) yielded 21 amplificates, whereas primers from the coding region produced 16 amplificates (nucleotides 4684-5276) and 5 amplificates (nucleotides 5166-5270), respectively. The most efficient combination of steps was RNA extraction with guanidinium salt solution, reverse transcription with Moloney murine leukaemia virus reverse transcriptase and nested polymerase chain reaction primed with primers from the 5'-terminal non-coding region of the hepatitis C virus genome. Other combinations produced more false negative results. Three different groups of anti-hepatitis C virus antibody positive individuals had markedly different viraemia patterns: Hepatitis C virus RNA was detected in the sera of only 10% of anti-hepatitis C virus antibody positive blood donors, but in 90% of anti-hepatitis C virus antibody positive patients with clinically manifest hepatitis C, and 90% of anti-hepatitis C virus antibody positive haemophiliacs who had received plasma products in the past which had not been virus-inactivated. No hepatitis C virus RNA could be detected in the sera of 450 anti-hepatitis C virus antibody negative blood donors with elevated serum alanine aminotransferase catalytic concentrations.
...
PMID:Improved detection of hepatitis C virus RNA by reverse transcription and polymerase chain reaction. 128 41

The prevalence of hepatitis C virus (HCV) infection among the patients of a hemodialysis unit in Taiwan was determined by an immunoblot and reverse transcriptase-polymerase chain reaction algorithm to be 58.8% (67 of 114 patients) after serological surveys with two advanced-generation enzyme-linked immunosorbent assays (ELISAs) for anti-HCV and a C 100-3 single-antigen test. The results of the second-generation ELISAs, the supplementary immunoblot test, and the test for HCV RNA were in good agreement with each other, from 86.0 to 98.2%. The first-generation C 100-3 test lacked the sensitivity of the four other systems. The two advanced-generation screening ELISAs for anti-HCV, a multiple-recombinant-antigen test, the Abbott second-generation ELISA, and a synthetic peptide multiple-antigen test, the UBI HCV EIA, provided reliable and virtually equivalent detection of potentially infected blood. Antibodies to capsid 1 and capsid 2 determinants of the Liatek immunoblot system were the most frequently detected reactivities to HCV in the HCV-infected hemodialysis patients. The percentage of HCV-infected patients with abnormal liver function (alanine aminotransferase level, greater than 100 IU/liter) was higher than that of the uninfected patients. The prevalence of HCV infection was correlated to the duration of hemodialysis treatment and the amount of blood transfused, and the most common transmission mode was thought to be patient-to-patient transmission through the dialysis equipment. Several means of reducing the frequency of transmission between hemodialysis patients are suggested.
...
PMID:Hepatitis C markers in hemodialysis patients. 768 54

We evaluated the clinical significance of the antibody to hepatitis C core protein (anti-p22) analysing 147 sera from 99 patients; 45 of them had post-transfusion non A non B (NANB) hepatitis, 28 cryptogenic non A non B hepatitis, 12 chronic hepatitis B, 7 chronic hepatitis D, 6 other forms of liver disease (4 primary biliary cirrhosis, 2 autoimmune hepatitis) and 1 rheumatoid arthritis. All sera were tested by commercial 1st and 2nd-generation ELISAs and anti-p22 single antibody ELISA. We found a highly significant correspondence between anti-p22 and commercial assays (p = 0.0001). HCV-RNA was detected by reverse transcriptase polymerase chain reaction (RT-PCR) in sera showing positive or negative concordant results and in all sera (24) that showed discordant results by anti-p22 and commercial ELISAs. HCV-RNA was found in 14 of 17 (82%) anti-p22 positive sera that were negative by commercial ELISAs, in 1 of 7 (14.3%) anti-p22 negative sera that were positive by commercial ELISAs (p = 0.001) and in all control sera from patients with positive concordant results. It was undetectable in 7 sera from patients with autoimmune diseases (negative by all ELISAs). We studied follow-up sera from 16 patients treated with interferon: 8 long-term responders (with persistently normal ALT levels for at least 24 months after discontinuation of therapy and histological remission) and 8 non-responders. Sera were also tested by a 4-antigen recombinant immunoblotting assay (RIBA II).(ABSTRACT TRUNCATED AT 250 WORDS)
...
PMID:Clinical significance of the antibody to the putative core protein of hepatitis C virus in patients with chronic liver disease. 769 Aug 74

Hepatitis C virus (HCV) infection is common in hemodialysis patients, as determined by antibody assays and qualitative polymerase chain reaction (PCR) analysis of serum HCV RNA. To further characterize HCV infection in this population, we measured the viral load in infected hemodialysis patients by a quantitative, competitive PCR assay (QC-PCR) for HCV RNA. Hepatitis C virus RNA levels were correlated with serologic, biochemical, and demographic features of a cohort of hemodialysis patients. Sera from 208 hemodialysis patients were screened for HCV RNA (5' conserved region) by reverse transcriptase PCR (RT-PCR) and HCV-specific antibody. Forty-four patients were antibody positive (21%); among these patients, 34 (77%) were HCV RNA positive. No viremic, seronegative patients were identified. Hepatitis C virus RNA levels quantitated by QC-PCR ranged from 3 x 10(5) to 10(8) molecules of HCV RNA/mL. Male patients had significantly higher mean and median HCV RNA levels (10(7) molecules/mL) compared with female patients (3.6 x 10(6) molecules/mL and 3 x 10(6) molecules/mL, respectfully; P = 0.02). No other demographic or clinical feature of this cohort correlated with HCV RNA levels. Intravenous drug abuse was the most frequently identified risk factor (29% of seropositive patients) for infection with HCV in this population. No association between HCV RNA levels and hepatic enzyme levels (alanine aminotransferase, aspartate aminotransferase, gamma-glutamyl transferase, alkaline phosphatase) was apparent. Hepatitis C virus infection is highly prevalent in our hemodialysis population, and hemodialysis patients, particularly males, have high levels of HCV in serum.(ABSTRACT TRUNCATED AT 250 WORDS)
...
PMID:Quantitation of hepatitis C viral RNA in sera of hemodialysis patients: gender-related differences in viral load. 797 21

Ultrastructural studies on cell cultures derived from TSP/HAM and ATL patients, show the presence of large quantities of HTLV-I viral particles in extracellular spaces and budding at the cytoplasmic membrane. In addition, mature enveloped particles and images of endopinocytosis of virions are seen in the cytoplasm vacuoles suggesting the existence of a reinfection phenomenon. In this context, we decided to investigate some features of the replicative cycle, in particular the synthesis of unintegrated proviral forms. To increase the sensitivity of detection, we applied a procedure which combines the electrophoretic separation of closed circular forms and PCR amplification. By this procedure we produced evidence for the existence of supercoiled HTLV-I DNA in established cell lines from TSP/HAM and ATL and in patients peripheral blood mononuclear cells. These HTLV-I unintegrated proviral forms may play an important role in the physiopathology of HTLV-I associated diseases. Preliminary results of AZT/interferon treatment in ALT patients are largely superior to chemotherapy. The therapeutic effect of AZT, it known inhibitor of reverse transcriptase, may be through its inhibition of the synthesis of HTLV-I unintegrated proviral DNA.
...
PMID:Unintegrated HTLV-I proviral DNA in cell lines and uncultured peripheral blood mononuclear cells from tropical spastic paraparesis (TSP/HAM) and adult T-cell leukemia (ATL) patients. 799 13

To analyze the serological, clinical and histological significance of hepatitis B virus (HBV) replication among a group of patients with chronic delta hepatitis (CDH), we have studied the clinical and the histological activity in 49 patients with CDH. The HBV-DNA was analyzed by dot-blot and polymerase chain reaction (PCR). Concomitant infection with hepatitis C virus (HCV) was analyzed by reverse transcriptase (RT)-PCR, HDV replication by dot-blot, and human immunodeficiency virus (HIV) infection by enzyme-linked immunosorbent assay. The subjects were divided into three groups according to HBV-DNA status: group I: 14 patients HBV-DNA dot-blot positive; group II: 29 patients HBV-DNA positive only by PCR, and group III: 6 patients HBV-DNA negative by dot-blot and PCR. We have found HBV-DNA by dot-blot in 28.5% of patients, and by PCR in 87.7%. Also 22 patients were anti-HCV positive (86.3% had HCV-RNA by RT-PCR). The first group (HBV-DNA dot-blot positive) had significantly higher serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) than those in the second and third groups. Likewise, serum ALT and AST were significantly higher in the second group (HBV-DNA positive by PCR) than in those of the third group. Histological inflammatory activity was significantly higher in the group of patients with HBV-DNA detectable by dot-blot. The prevalence of serum HDV-RNA and IgM anti-HDV were similar in the three groups. These results were similar in the anti-HCV-positive and -negative patients. In conclusion, these data suggest that: (1) persistence of HBV replication is a major determinant of severe liver damage in chronic delta hepatitis, and (2) HCV and HIV infections do not influence the natural history of CDH.
...
PMID:Correlation between hepatitis B viremia and the clinical and histological activity of chronic delta hepatitis. 799 89

The infectivity titer of a standard stock of the SAR-55 strain of hepatitis E virus (HEV) was determined in cynomolgus macaques (Macaca fascicularis) and the effect of dose on the course of the infection was examined by weekly monitoring of alanine aminotransferase (ALT) and anti-HEV levels. Antibody to HEV (anti-HEV) was measured with ELISAs based on ORF-2 recombinant antigens consisting of either a 55 kDa region expressed in insect cells or shorter regions expressed as fusion proteins in bacteria. The ELISA based on the 55 kDa antigen was generally more sensitive. The infectivity titer of SAR-55 was 10(6) cynomolgus 50% infectious doses per gram of feces. The infectivity titer corresponded to the HEV genome titer of the inoculum as determined by reverse transcriptase-polymerase chain reaction (RT-PCR). Anti-HEV IgM was detected in only a portion of the animals that had an anti-HEV IgG response. Biochemical evidence of hepatitis was most prominent in animals that were inoculated with the higher concentrations of virus and the incubation period to seroconversion was prolonged in animals that received the lower doses.
...
PMID:Infectivity titration of a prototype strain of hepatitis E virus in cynomolgus monkeys. 808 60

The hepatitis C virus (HCV) genome was sought in the saliva of 76 chronic HCV carriers (mean age nearly 60 years) in a rural Japanese town, who had high serum titers of c-100 and anti-core second generation antibodies. In 27 samples (27 cases, 36%), the HCV-RNA genome was detected by the reverse transcriptase - polymerase chain reaction with either of two sets of primers covering two regions of the HCV genome: the 5'noncoding region and the region encompassing the putative envelope (E1). Transaminase values at the time of sampling were higher in the patients with than in those without detectable HCV RNA in saliva (p = 0.04 for alanine aminotransferase, p = 0.04 for aspartate aminotransferase; Wilcoxon test). The prevalence of the positivity was higher by 5'noncoding primers (14/59 vs. 15/68). Our data show that the severity and duration of hepatic dysfunction influence the detectability of the HCV genome in the saliva. This has been a controversial point among investigators.
...
PMID:Correlation of detectability of hepatitis C virus genome in saliva of elderly Japanese symptomatic HCV carriers with their hepatic function. 855 81

The hepatitis G virus (HGV) has recently been identified as a new member of the Flaviviridae family. Infection by this virus is thought to be associated with blood borne hepatitis. In this study, the presence of HCV- and HGV-RNAs in serum or plasma (175 patients) and in peripheral blood mononuclear cells (PBMC) (133 patients) was investigated in patients with clotting disorders using a sensitive reverse transcriptase polymerase chain reaction (RT-PCR). HGV-RNA was detected in serum of 26 patients (14.8%). In apparently healthy blood donors, serum HGV-RNA was detected in 4 of 358 individuals investigated (1.12%). Ninety two percent of the 26 serum HGV-RNA positive patients had coinfection with the hepatitis C virus (HCV), especially with HCV genotype 1b, the most common genotype in Belgium. Of these coinfected patients, 15 (62.5%) showed elevated serum ALT levels. Two patients who were solely infected with HGV had normal serum ALT.HGV-RNA in PBMC was found in 18 patients, of whom 3 were negative for serum HGV-RNA. As in case of HCV, HGV-RNA in PBMC is preferentially sensitive to interferon treatment. Nevertheless, rapid reappearance of HGV-RNA in PBMC was observed after cessation of treatment. In one patient, persistent serum ALT elevation seems to be associated with continued HGV viremia, despite the disappearance of serum HCV-RNA.
...
PMID:Hepatitis G viral RNA in serum and in peripheral blood mononuclear cells and its relation to HCV-RNA in patients with clotting disorders. 918 94

Isolation and cloning of abundant reverse transcriptase-polymerase chain reaction (RT-PCR) products from the filarial nematode Brugia malayi using the conserved nematode spliced leader sequence and poly A as amplification targets has allowed us to identify abundant, stage specific transcripts from infective and post-infective larvae. The predicted protein products of the most prominent full-length transcripts from mosquito-derived L3 parasites are: (i) Bm-ALT-1, a homologue of a Dirofilaria immitis abundant larval protein: (ii) Bm-CPI-1, a cystatin-type cysteine protease inhibitor; (iii) Bm-ALT-3, a novel predicted 6 kDa glycine/tyrosine-rich protein; and (iv) Bm-TPH-1, a homologue of a mammalian translationally-controlled tumour protein. Some transcripts were not full-length but had mis-primed at A-rich stretches of coding sequence: the most abundant of these was Bm-col-3, a which encodes a collagen homologous to Bp-COL-1 of Brugia pahangi. Similar analysis of abundant spliced leader (SL)/oligo-dT products from fourth-stage larvae 9 days post-infection yielded two dominant transcripts: (i) Bm-cdd-1, which encodes a protein with homology to cytidine deaminase, differing at only one amino acid position from its homologue described in Brugia pahangi; and (ii) the same truncated form of Bm-col-3 found in L3 preparations. Expression of the major transcripts was assessed by PCR amplification of cDNA libraries derived from each stage of the life cycle. alt1, alt-3 and cpi-1 were all found to be specific to the L3 stage, while cdd-1 was found only in the L4 cDNA library. Expression of these larval-specific transcripts was not detected in either microfilarial or adult libraries.
...
PMID:Differentially expressed, abundant trans-spliced cDNAs from larval Brugia malayi. 923 76


1 2 3 4 5 6 7 8 9 10 Next >>

---