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1.
Large-scale DNA sequencing is creating a sequence infrastructure of great benefit to protein biochemistry. Concurrent with the application of large-scale DNA sequencing to whole genome analysis, mass spectrometry has attained the capability to rapidly, and with remarkable sensitivity, determine weights and amino acid sequences of peptides. Computer algorithms have been developed to use the two different types of data generated by mass spectrometers to search sequence databases. When a protein is digested with a site-specific protease, the molecular weights of the resulting collection of peptides, the mass map or fingerprint, can be determined using mass spectrometry. The molecular weights of the set of peptides derived from the digestion of a protein can then be used to identify the protein. Several different approaches have been developed. Protein identification using peptide mass mapping is an effective technique when studying organisms with completed genomes. A second method is based on the use of data created by tandem mass spectrometers. Tandem mass spectra contain highly specific information in the fragmentation pattern as well as sequence information. This information has been used to search databases of translated protein sequences as well as nucleotide databases such as expressed sequence tag (EST) sequences. The ability to search nucleotide databases is an advantage when analyzing data obtained from organisms whose genomes are not yet completed, but a large amount of expressed gene sequence is available (e.g., human and mouse). Furthermore, a strength of using tandem mass spectra to search databases is the ability to identify proteins present in fairly complex mixtures.  相似文献   

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Hepatitis C virus (HCV) is an important cause of liver injury following liver transplantation in adults. We hypothesized that the prevalence of HCV infection in children following liver transplantation would be lower than the prevalence in adults after liver transplantation because HCV-related liver disease leading to liver transplantation in children is low and children require less blood products than adults during transplantation. We therefore performed a cross-sectional study to determine the prevalence of HCV infection in children who had undergone liver transplantation. Serum samples were obtained from 62 of 65 (95.4%) consecutive patients surviving for more than six months after transplantation. Using a second-generation enzyme-linked, immunosorbent assay (ELISA-2) and a second-generation recombinant immunoblot assay (RIBA-II), antibodies to HCV were detected in 5.1% (3 of 59) of the subjects. Using a single-step, polymerase chain reaction (PCR), HCV RNA was detected in 6.2% (4 of 62). All HCV-positive children had undergone liver transplantation before the initiation of routine screening for HCV in blood donors; overall 30 patients were transplanted prior to routine screening of blood products for HCV. The prevalence of HCV in infants and children after liver transplantation in our study is substantially less than the rates reported in adults. This difference may be due, in part, to the lower volume of blood product exposure and to the fact that children, as opposed to adults, rarely have chronic HCV infection as a cause of end-stage liver disease.  相似文献   

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Hepatitis G virus (HGV) is a newly described RNA virus that is parenterally transmitted and has been found frequently in patients with chronic hepatitis C infection. To determine the impact of hepatitis G virus co-infection on morbidity and mortality following liver transplantation, we measured HGV RNA by polymerase chain reaction in pre and posttransplantation sera from a cohort of patients transplanted for chronic hepatitis C and a control group of patients transplanted for nonviral causes who were negative for hepatitis C virus (HCV) RNA in serum. The overall prevalence rate of HGV RNA in transplanted patients with chronic hepatitis C was 20.7%. HGV infection was present before transplantation in 13% while it appeared to have been acquired at the time of transplantation in 7.4%. Mean serum alanine aminotransferase activity, hepatic histological activity, and patient and graft survival were similar between HGV-positive and HGV-negative patients. The prevalence rate of HGV RNA in transplanted controls was 64% (P < .01) with a significantly higher rate of acquisition of HGV infection following transplantation (53%, P < .001) when compared with patients with chronic hepatitis C. Mean serum alanine aminotransferase activity was significantly lower in the control patients with HGV infection alone following transplantation than in patients co-infected with hepatitis C (37 +/- 9 vs. 70 +/- 33 U/L, P < .01). Thus, HGV is frequently found in transplantation patients co-infected with hepatitis C although it appears to have minimal clinical impact. In patients transplanted for nonviral causes of end-stage liver disease, a high rate of hepatitis G acquisition at the time of transplantation may occur but does not appear to predispose to chronic hepatitis.  相似文献   

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BACKGROUND: It is known that in patients with porphyria cutanea tarda (PCT) there is an increased prevalence of the hepatitis B virus (HBV) and the hepatitis C virus (HCV). The incidence of anti-HCV in PCT in our country is 21.7% in estimations by the second generation method, however, the incidence of HBV in PCT was not assessed so far. METHODS AND RESULTS: In 60 patients with PCT antigens and antibodies against HBV and HCV were assessed (by the anti-HCV third generation ELISA method) and in subjects with signs of HBV or HCV. HBV DNA and HCV RNA were assessed by the method of the polymerase chain reaction. PCT without detectable HBV or HCV infection was found in 45 subjects (68%). HBV infection only was confirmed in seven subjects (10.6%), however none of the patients had positive HBsAg in serum. All had only antibodies against HBV. HCV infection only was detected in seven patients (10.6%) and HBV and HCV co-infection also in seven patients (10.6%). In the group of patients with HBV and HCV co-infection there was not a single HBsAg positive subject. The mean ALT serum activity was significantly higher as compared with subjects with HBV or HCV infection only (p < 0.05) and the histological finding on liver biopsy was more serious. CONCLUSION: HBV (21%) and HCV (21%) infection participates significantly in the clinical picture of PCT. A special subgroup is formed by patients with PCT and HBV and HCV co-infection who have as a rule a higher ALT activity and more severe histological changes in the liver. The incidence of HBV and HCV infection in PCT in the Czech Republic is double as compared with Germany or Great Britain.  相似文献   

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Cutaneous necrosis may occur as a complication of treatment with interferon. Here we report the first case of cutaneous necrosis developing in a patient receiving interferon alpha-2b for the treatment of chronic hepatitis C viral infection. The patient developed two necrotic lesions while receiving high doses of interferon. We suggest that discontinuation of treatment may be necessary to permit healing of such lesions. Although the exact mechanism involved in cutaneous necrosis remains unknown, our observations support earlier findings suggesting that intraarterial injection may be a factor.  相似文献   

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Hepatitis G virus (HGV) is prevalent in patients with chronic liver disease and has been previously detected in liver specimens. However, it is unknown whether the virus is replicating in the liver or is simply a contaminant from serum. We sought to determine whether HGV was hepatotropic and to determine whether coinfection with HGV and hepatitis C virus (HCV) influenced the level of either virus. Virus was quantitated using branched DNA (bDNA) assay for both HGV and HCV in the liver explants and pretransplant serum samples from 30 transplant recipients: Group I, HGV/HCV coinfection (n = 10); group II, HCV infection alone, (n = 8); group III, HGV alone (n = 12). In patients with coinfection HCV (RNA) titers in liver were consistently higher than those for HGV RNA (median 1.13 x 10(8) and 360,000 Eq/g respectively, P < .01). The ratio of liver/serum viral RNA was significantly higher for HCV than for HGV (median 129 and 0.3 respectively, P < .01). Levels of HCV RNA were similar in patients with HCV infection alone versus those with HGV/HCV coinfection (median; liver = 1.15 x 10(7) vs. 1.13 x 10(8) Eq/g, serum = 500,000 vs. 200,000 Eq/mL) and levels of HGV RNA in liver and serum were similar in patients with HGV infection alone compared to those with HGV/HCV coinfection (median; liver = 1.2 x 10(6) vs. 4.0 x 10(5) Eq/g, serum = 4.5 x 106 vs. 2.6 x 10(6) Eq/mL). Levels of either virus appeared unaffected by the presence of an additional virus. The high ratio of HCV RNA levels in liver compared to serum is consistent with its known hepatotropism, but this pattern was not observed for HGV. The median liver/serum ratio of HGV RNA was less than unity, a finding consistent with serum contamination of liver tissue. Thus we conclude that the liver is not the main site of HGV replication.  相似文献   

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This paper considers the contributions by age of the various major groups of deaths to the increase in life expectancy at birth between 1980 and 1990 for both sexes in Singapore. Sixteen cause groups were used in the study. The data were analysed using LIFETIME, a personal computer package with a wide variety of methods for mortality investigations. Respiratory diseases made the largest contribution to the increase in life expectancy for both sexes. In contrast, ischaemic heart disease made a negative contribution of 1% in the gain in female life expectancy but contributed 12% improvement for males. Life tables for Singaporean males and females in the year 2000 were projected by extrapolating the mortality trends observed in earlier periods. The calculations show that the life expectancy at birth in the year 2000 to be 74.72 years for males and 79.48 years for females.  相似文献   

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As the importance of the right ventricle in many diseases and conditions has been realized, the need for quantitative assessment of the motion and contraction of the right ventricular free wall (RVFW) has become apparent. This study applied the myocardial tagging magnetic resonance imaging (MRI) technique to the normal RVFW to elucidate normal heterogeneity in RV motion and contractile patterns. The RVFW was divided into three segments (inferior, mid and superior) in each of three slices (apical, mid and basal) to allow for a detailed analysis of the motion and contraction. Percent segmental shortening (PSS) was used to measure the amount of contraction, and a vector analysis was used to quantitate the trajectory of the RVFW through systole. PSS increased monotonically through time to an average across all segments of 12% in the basal slice, 14% in the mid-ventricular slice, and 16% in the apical slice of the heart. The trajectory of the RVFW was characterized by a wave of motion toward the septum and outflow tract. The data provided in this study provide a better understanding of normal RV kinematics and can serve as a comparison for disease states.  相似文献   

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Hepatitis frequently recurs after liver transplantation for hepatitis C. However, the histological progression of disease, predictors of recurrence and disease severity, and patient survival remain uncertain. Fifty-five patients with cirrhosis caused by chronic hepatitis C underwent liver transplantation between January 1990 and December 1993. Hepatitis C genotype was determined, and liver biopsies were performed at frequent intervals posttransplantation. The median follow-up time was 40.4 months. The cumulative rate of survival was no different in liver transplant recipients for hepatitis C than in liver transplant recipients for other chronic liver diseases (P = .62). Histological recurrent hepatitis C developed in 33 of 50 patients assessable for disease recurrence; the median recurrence-free survival time was 13.4 months. Histological activity and stage were mild in most cases. Only 2 patients developed cirrhosis, and no patient required a second transplantation for recurrent disease. Patients with acute cellular rejection had a shorter recurrence-free survival (P = .0141). In patients with recurrent hepatitis, rejection also was correlated with increased histological grade 2 years after transplantation (P = .0061). Recurrence-free survival was decreased in patients infected with genotype 1 (1a and 1b combined) compared with genotypes 2 and 3 combined (P = .02), whereas there was no difference between genotypes 1a and 1b (P > .80). Only patients infected with genotype 1a or 1b developed bridging fibrosis or cirrhosis. In addition, patients who had an early recurrence had a greater risk of progressing to bridging fibrosis or cirrhosis (hazard ratio, 5.1; P = .0473). In our experience, recurrent hepatitiS C after liver transplantation in most cases is mild and survival is unaffected. Both acute cellular rejection and infection with genotype 1 are independent risk factors for reduced recurrence-free survival, and early recurrence is associated with a higher risk of disease progression.  相似文献   

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Sera of 658 patients who had completed treatment for pediatric malignancy were analyzed by a second-generation enzyme-linked immunosorbent assay and recombinant immunoblot assay test to assess the prevalence of hepatitis C virus (HCV)-seropositivity. All HCV-seropositive patients underwent detailed clinical, laboratory, virologic, and histologic study to analyze the course of HCV infection. One hundred seventeen of the 658 patients (17.8%) were positive for HCV infection markers. Among the 117 anti-HCV+ patients, 41 (35%) were also positive for markers of hepatitis B virus infection with or without delta virus infection markers, 91 (77.8%) had previously received blood product transfusions, and 25 (21.4%) showed a normal alanine aminotransferase (ALT) level during the last 5-year follow-up (11 of them never had abnormal ALT levels). The remaining 92 patients showed ALT levels higher than the upper limit of normal range. Eighty-one of 117 (70%) anti-HCV+ patients were HCV-RNA+, with genotype 1b being present in most patients (54%). In univariate analysis, no risk factor for chronic liver disease was statistically significant. In this study, the prevalence of HCV infection was high in patients who were treated for a childhood malignancy. In about 20% of anti-HCV+ patients, routes other than blood transfusions are to be considered in the epidemiology of HCV infection. After a 14-year median follow-up, chronic liver disease of anti-HCV+ positive patients did not show progression to liver failure.  相似文献   

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Long-term effects after blood or bone marrow transplantation (BMT) are emerging as an important issue, as more patients are included in BMT programmes and as this procedure becomes more successful. Long-term liver dysfunction, mainly due to chronic graft-versus-host disease or hepatitis C virus infection, is a well-known complication. Nevertheless, the diagnosis of liver disease in this patient group is sometimes difficult and, despite adequate studies, it may remain undetected. A novel hepatitis-associated virus, hepatitis G virus (HGV), has recently been identified. The virus belongs to the Flaviviridae family and is known to be parenterally transmitted, although there is no clear evidence to implicate this agent in causing acute or chronic hepatitis. We report a patient who developed mild, but persistent, abnormalities in transaminases for 2 years after an autologous BMT. HGV RNA was detected in both serum and liver. HGV RNA persisted in serum for at least 8 months. No other known hepatitis virus was found. This report provides the first direct evidence of a patient with long-term liver abnormalities after a BMT in whom the only known hepatitis virus isolated was the HGV.  相似文献   

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BACKGROUND: Indication of liver transplantation for patients infected with hepatitis B virus (HBV) remains controversial because of the high incidence of posttransplant HBV recurrence and aggressive involvement of the allograft. In this article, we provide evidence that the introduction of lamivudine may favorably alter the prognosis of these patients. METHODS: Lamivudine was used in 40 HBV-infected adult patients suffering from chronic end-stage liver disease who underwent liver transplantation. The drug was used in the following settings: failure of prolonged passive immunoprophylaxis, elective conversion from immunoprophylaxis, de novo posttransplant HBV infection, and primary treatment with lamivudine which started before and continued after transplantation. Twenty patients (50%) had viral replication at the time lamivudine was started. Posttransplant and antiviral treatment follow-ups were 8-64 months (median follow-up: 27.5 months) and 9-39 months (median follow-up: 19 months), respectively. RESULTS: The patient and graft survival rates were 97.5% (39/40). Thirty-three patients (82.5%) have remained free of viral recurrence. In the seven re-infected patients, the manifestations of HBV involvement of the allograft have been mild. There have been no side effects related to lamivudine, and the treatment is substantially less costly than with other anti-HBV agents. CONCLUSIONS: Compared with historic series utilizing other modalities of treatment, the use of lamivudine has, so far, yielded superior results. This drug may be an important acquisition for antiviral prophylaxis in HBV-infected liver recipients. Because of the risk of viral mutations, however, efforts should proceed to achieve more efficacious methods for prevention and control of HBV recurrence.  相似文献   

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The antiphospholipid syndrome, disorder in which venous and arterial thrombosis may occur, has been described in association with systemic lupus erythematosus and later in a great variety of entities, including infectious diseases. It has been described recently a high frequency of antiphospholipid syndrome in patients with chronic hepatitis C. We present a case of cirrhosis with hepatitis C virus markers and criteria for antiphospholipid syndrome, and we review the literature.  相似文献   

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