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)

The introduction of newer technology in the past few years, especially the use of second-generation enzyme-linked immunosorbent assays, recombinant immunoblot assays, reverse transcriptase, and DNA amplification, have clearly defined the role of hepatitis C virus as the most important etiologic factor in the development of mixed cryoglobulinemia. This has led to a better understanding of the pathogenic mechanisms involved in disease expression, particularly vasculitis, and also has provided a rationale for the use of interferon alfa and other antiviral drugs in the therapy of these disorders. The clinical manifestations of the syndrome also have been well characterized, as well as some of the risk factors. There also has been an improvement in our understanding of the pathogenic mechanisms involved in multiple myeloma and related monoclonal gammopathies, as well as several attempts to improve early recognition of bone disease with magnetic resonance imaging. The susceptibility gene for familial Mediterranean fever has been better characterized, as have risk factors for colchicine toxicity. The role of cytokines has been better delineated for both monoclonal gammopathies and POEMS (polyneuropathy, organomegaly, endocrinopathy, M protein, and skin changes) syndrome.
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PMID:Cryoglobulinemia and other dysproteinemias, familial Mediterranean fever, and POEMS syndrome. 771 25

Chimpanzees are currently the only nonhuman animal model for reproducible propagation of hepatitis C virus (HCV). A chimeric mouse model was used for the induction of hepatitis C viremia, using BNX (beige/nude/X-linked immunodeficient) mice preconditioned by total body irradiation and reconstituted with SCID mouse bone marrow cells. HCV-infected liver fragments from patients with HCV RNA-positive sera were transplanted under the kidney capsule of the chimeric mice. HCV-specific RNA sequences were detected by reverse transcriptase nested polymerase chain reaction (RT-PCR) in serum of approximately 50% of grafted animals. In addition, normal liver specimens were incubated with HCV serum and transplanted into chimeric mice, leading to viremia in approximately 25% of animals. Sequential histologic evaluation of the liver implants, from day 2 to week 14 after transplantation, revealed loss of lobular architecture within the implants. However, viremia persisted for 10-50 days after transplantation. These results offer a new HCV model.
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PMID:Hepatitis C virus viremia in SCID-->BNX mouse chimera. 779 23

We present here thirteen patients (5 men and 8 women, aged 31 to 73, mean 55 years) with spastic paraparesis who showed clinical features similar to those of HTLV-1 associated myelopathy without HTLV-1 antibody, but with positive antibody to hepatitis B virus (HBV). All of these patients showed slowly progressive difficulty in walking. Five patients had previous histories of blood transfusion, of these one with history of B hepatitis. Neurologically, muscle weakness, spasticity and exaggerated deep tendon reflexes in the lower extremities were common to all the patients. Seven patients showed Babinski's reflex. Disturbance of micturition was noted in 3 patients. None showed organic changes of the spine on magnetic resonance image (MRI). None was serologically positive for syphilis and had cryoglobulin and hypergammaglobulinemia. Elevated levels of the liver enzymes were noted in two patients. All patients were positive for hepatitis B surface antibody (HBs-Ab) (EIA) but negative for hepatitis B surface antigen (HBs-Ag) (EIA). Five patients were seropositive for hepatitis C virus (HCV) (PHA). In 3 of them, reverse transcriptase polymerase chain reaction was performed but failed to detect HCV-RNA. All patients underwent spinal tap, and showed normal cell count and protein concentration in their cerebrospinal fluid (CSF). Atypical cells were not observed in all the patients. The CSFs from three patients were tested for HBs-Ag and HBs-Ab. HBs-Ag was negative in all three patients, but HBs-Ab was positive in two patients.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Hepatitis B virus antibody positive spastic paraparesis]. 795 26

A sensitive, non-isotopic method for detecting and quantifying hepatitis C virus (HCV) RNA in serum using the reverse transcriptase-polymerase chain reaction (RT-PCR) and a hybridization specific, colorimetric biotin-avidin peroxidase detection system has been developed. The sensitivity of the PCR-colorimetric system was determined using RNA synthesized from cloned HCV cDNA. The assay could detect as few as 10 molecules of HCV RNA, comparable to the sensitivity achieved with double PCR using nested primers. Thus, this colorimetric assay can detect low levels of HCV RNA in serum and appears to be quantitative, suggesting that this technique may be applied to rapid screening of large numbers of samples and to monitor the effect of antiviral therapy.
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PMID:Detection and quantitation of hepatitis C virus RNA in serum using the polymerase chain reaction and a colorimetric enzymatic detection system. 796 61

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)
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PMID:Quantitation of hepatitis C viral RNA in sera of hemodialysis patients: gender-related differences in viral load. 797 21

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.
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PMID:Correlation between hepatitis B viremia and the clinical and histological activity of chronic delta hepatitis. 799 89

Analysis of hepatitis C virus (HCV) replication has been hampered due to the difficulty encountered in in vitro cultivation of the virus in conventional tissue culture systems. In this study, primary chimpanzee hepatocyte cultures maintained in a serum-free medium formulation were susceptible to in vitro infection with HCV. In order to document infection, two new methods of reverse transcription/polymerase chain reaction were developed that permit accurate distinction between positive and negative strand HCV RNA. One method relied upon the use of a tagged cDNA primer, while the second method employed a thermostable reverse transcriptase. Following inoculation of chimpanzee hepatocytes with HCV, intracellular positive and negative strand HCV RNA were detectable 4 days postinfection and throughout the remainder of the experimental period, 25 days. Analysis of HCV-inoculated baboon hepatocytes revealed a total absence of negative strand HCV RNA, while residual positive strand RNA from the inoculum could be detected for up to 11 days. The in vitro replication of HCV RNA in chimpanzee hepatocytes could be suppressed by alpha-interferon. This system should be amenable to the study of HCV replication, antiviral compounds, and the development of neutralization assays.
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PMID:Demonstration of in vitro infection of chimpanzee hepatocytes with hepatitis C virus using strand-specific RT/PCR. 803 Feb 25

To investigate mother-to-infant transmission of hepatitis C virus, serial follow-up of anti-HCV and hepatitis C virus RNA was undertaken in 11 infants born to hepatitis C virus-infected mothers who had been screened from 11,688 pregnant women. None of the hepatitis C virus-infected mothers was infected by human immunodeficiency virus. Anti-HCV was checked by the second-generation enzyme immunoassay kit, and hepatitis C virus RNA was examined by reverse transcriptase-nested polymerase chain reaction. Hepatitis C virus RNA was found in more than two serum samples in two of these 11 infants; those two infants were regarded as hepatitis C virus-infected. One of the two had hepatitis C virus RNA at the age of 1, 3, and 6 months, but not later. The course of hepatitis C virus RNA and anti-HCV in this baby may reflect fluctuating viral replication in chronic infectious disease or viral clearance in acute infection. The other infant had hepatitis C virus RNA detectable at the age of 3 months and at 15, 18 and 24 months. In the other nine non-hepatitis C virus-infected infants, maternally acquired anti-HCV gradually disappeared by the age of 6 months. The liver function profile fell to the normal range in all the infants, including the two hepatitis C virus-infected infants. This may indicate the subclinical nature of hepatitis C virus infection in infancy. Seven fathers and four siblings of these 11 infants were checked for anti-HCV and liver function tests; none had evidence of hepatitis C virus infection.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Temporal profile of hepatitis C virus antibody and genome in infants born to mothers infected with hepatitis C virus but without human immunodeficiency virus coinfection. 807 41

The presence of hepatitis C virus (HCV) RNA in serum and liver tissue was examined in seven patients with hepatocellular carcinoma (HCC), using the reverse transcriptase-polymerase chain reaction method with primers for the 5'-noncoding region. Plus-strand HCV-RNA was detected in the serum and liver tissue (both cancerous and noncancerous tissue) of all five patients who were positive for anti-HCV antibodies (C100-3 and P22) and was not detected in both of two patients who were negative for anti-HCV antibodies. Minus-strand HCV-RNA was only detected in the liver tissue (cancerous and noncancerous portion) of the five anti-HCV antibody-positive patients. The relative liver tissue content of minus-strand HCV-RNA ranged from 1 to 100 time less than that of plus strand HCV-RNA in cancerous and noncancerous tissue in each patient, respectively. There was no similar tendency in the HCV-RNA content between the cancerous and noncancerous portions of the liver in each patient. These results suggest that HCV exists and replicates in HCC tissue and may have some role in the development of HCC.
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PMID:Hepatitis C virus plus- and minus- strand RNA in hepatocellular carcinoma and adjoining nontumorous liver. 810 65

Quantitation of the hepatitis C virus (HCV) provides a powerful epidemiologic and therapeutic method for the evaluation of infected patients. In this study semiquantitative reverse transcriptase polymerase chain reaction (PCR) is compared with a new branched DNA signal amplification methodology. Samples from HCV-infected patients as well as from human immunodeficiency virus-infected patients were evaluated. Reverse transcriptase PCR correlated well with the branched DNA assay (r = 0.7036, P < 0.05). HCV RNA was found to occur at significantly higher titers (P < 0.05) in patients coinfected with the human immunodeficiency virus compared with titers in those infected with HCV alone. Immune status as defined by the CD4+ count was not associated with the observed difference in viral titer.
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PMID:Quantitative evaluation of hepatitis C virus RNA in patients with concurrent human immunodeficiency virus infections. 825 65


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