Search results for " DNA"
showing 10 items of 2475 documents
Effect of antiviral treatment and host susceptibility on positive selection in hepatitis C virus (HCV).
2007
Abstract We have conducted a large sequence study of the E1–E2 and NS5A regions of the HCV, subtypes 1a and b, both in patients previously treated with interferon, and untreated patients, who later responded, or not, to a combination therapy based on interferon plus ribavirin. We have examined the role played by the number of positively selected sites on disease progression and its relationship with several variables such as patients’ age, sex and their risk of acquiring the disease. We have detected three groups of patients that respond or not to combination therapy: responders of intermediate age, older non-responders and young non-responders, they possess an increasing average number of …
Trends for genetic variation of Hepatitis C Virus quasispecies in Human Immunodeficiency virus-1 coinfected patients
2007
Chronic infection by Hepatitis C Virus (HCV) causes liver fibrosis, which is accelerated by unknown mechanisms in patients with HIV-1 coinfection. The evolution of HCV quasispecies in this setting of coinfection is not fully understood. To compare HCV quasispecies between HIV-HCV coinfection and HCV monoinfection, we sequenced 340 HCV clones from the HVR-1 and NS3 regions at two different time points in two groups of treatment-naive patients with HCV-1a infection: (1) HIV-HCV positive (n=6); and (2) HIV negative-HCV positive (n=3). In HCV/HIV coinfection, we found a trend for reduced HCV genetic complexity and diversity, and a trend towards reduced dN/dS ratios in the HVR-1 region, especial…
Analysis of translocations that involve theNUP98 gene in patients with 11p15 chromosomal rearrangements
2004
The NUP98 gene has been reported to be fused with at least 15 partner genes in leukemias with 11p15 translocations. We report the results of screening of cases with cytogenetically documented rearrangements of 11p15 and the subsequent identification of involvement of NUP98 and its partner genes. We identified 49 samples from 46 hematology patients with 11p15 (including a few with 11p14) abnormalities, and using fluorescence in situ hybridization (FISH), we found that NUP98 was disrupted in 7 cases. With the use of gene-specific FISH probes, in 6 cases, we identified the partner genes, which were PRRX1 (PMX1; in 2 cases), HOXD13, RAP1GDS1, HOXC13, and TOP1. In the 3 cases for which RNA was a…
Cholinesterase variants: rapid characterisation by PCR/SSCP and evidence for molecular homogeneity.
1995
We have applied the technique of PCR-SSCP (polymerase chain reaction-single stranded conformation polymorphism) to characterise the molecular basis of cholinesterase deficiency and variants in a Jordanian family. PCR-SSCP proved to be a quick and sensitive method of screening cholinesterase variants in a clinical setting. An AG insertion at position 351 was found to cause a silent allele, for which the parents were heterozygous and three children homozygous. In addition, the father and two sons were heterozygous for an A to G transition at position 209, known to cause the dibucaine resistant variant. No linkage to the K variant was found, which has been reported previously in white populati…
A study on occupational exposure of Sicilian farmers to Giardia and Cryptosporidium
2013
Introduction. A cross-sectional study was undertaken to deter- mine the prevalence of Giardia and Cryptosporidium in calves of Palermo area (Sicily) and to evaluate the occupational risk associated with occurrence of zoonotic genotypes. Methods. A total of 217 faecal samples, from 149 calves (between 2 and 240 days of age) and 68 farmers, were collected in 19 cattle- farms of Palermo area. A questionnaire regarding demographic characteristics and personal hygienic measures was submitted to all farmers. All faecal samples were analyzed by Immunoflu- orescence assay and Polimerase Chain Reaction (PCR); geno- types were determined by DNA sequencing of Triose Phosphate Isomerase gene for Giardi…
Can the serological status of anti-HBc alone be considered a sentinel marker for detection of occult HBV infection?
2008
Some individuals have “occult” infection with hepatitis B virus (HBV), defined as presence of HBV genome in the serum or liver tissue without HBV surface antigen (HBsAg) in the serum. The aim of this study was to investigate whether serum antibodies against HBV core antigen in isolation (“anti-HBc alone”) are a useful marker of “occult” HBV in patients with or without hepatitis C virus (HCV) infection. “Anti-HBc alone” was detected in the sera of 119/6,544 (1.8%) asymptomatic outpatients referred to the diagnostic laboratory for routine testing for viral hepatitis, 62/607 (10.2%) drug users, and 42/195 (21.5%) patients with hepatocellular carcinoma. Using three in-house nested-PCR amplifica…
HBV DNA suppression and HBsAg clearance in HBeAg negative chronic hepatitis B patients on lamivudine therapy for over 5 years
2012
Background & Aims In long-term responder patients, it is unclear whether lamivudine (LAM) monotherapy should be continued or switched to a high-genetic-barrier analogue. This study aims at assessing LAM efficacy over a 5-year period and the residual risk of drug resistance. The rate of HBsAg clearance and LAM long-term safety profile were also evaluated. Methods One hundred and ninety-one patients with chronic HBeAg-negative hepatitis B successfully treated with LAM monotherapy for at least 5years were included. Biochemical and virological tests were assessed every 3months in all patients and HBsAg quantification was performed in 45/191. Reverse-transcriptase (RT) region was directly sequen…
Detection of Epstein-Barr virus (EBV) DNA and antigens in oral mucosa of renal transplant patients without clinical evidence of oral hairy leukoplaki…
1998
The use of the polymerase chain reaction (PCR) to detect the presence of Epstein-Barr virus (EBV) DNA in oral mucosa in the absence of specific lesions gives rise to the problem of identifying the real viral replication sites. To verify whether the detection of EBV is due to salivary contamination or its true replicative capacity in oral mucosa, saliva samples and exfoliated cells from four different oral mucosa sites were taken from 40 renal transplant patients and 20 normal subjects for examination by PCR using two pairs of primers specific for the BamHI-L and BamHI-K genomic regions. EBV-specific sequences were detected in one or more of the oral mucosa samples from 29 transplant patient…
Hepatitis B and C virus variants in long-term immunosuppressed renal transplant patients in Latvia.
2004
The incidence of genome variants of hepatitis B and hepatitis C viruses among 38 long-term (2–15 years) immunosuppressed patients after renal transplantation and 10 patients undergoing dialysis was investigated. Twelve patients had only HBV infection, 9 had only HCV infection and 14 were co-infected. Regions corresponding to the HBV X/EnII/BCP, preC/C, preS/S and to the HCV core were sequenced for molecular characterization of the HBV and HCV genomes. Fifty-seven percent of HBV DNA isolates belonged to genotype D and 42% to genotype A, whereas 77% of HCV RNA isolates belonged to genotype 1b and only 17% to genotype 3a. One sample (6%) was of genotype 2c. Detailed analysis of the above-menti…
Occult hepatitis B virus in liver tissue of individuals without hepatic disease
2008
Abstract BACKGROUND/AIMS: While many data are available concerning occult hepatitis B virus (HBV) infection in patients with hepatic disorders, there is little information about this cryptic infection in individuals without liver disease. The aim of this study was to investigate the prevalence of occult HBV in the general population by examining liver specimens from a large series of HBV-surface-antigen negative individuals with no clinical and biochemical evidence of liver disease. METHODS: The presence of HBV DNA was evaluated by testing, through polymerase chain reaction techniques, DNA extracts from 98 liver-disease-free individuals who underwent liver resection or needle biopsy during …