Search results for "Polymerase"
showing 10 items of 2127 documents
Rare pre-core stop-codon mutant nt. 1897 predominates over wide-spread mutant nt. 1896 in an unusual course of chronic hepatitis B
1996
We present a patient with an unusual course of hepatitis B e antigen (HBeAg)-negative chronic hepatitis B who had repeated reactivations of his disease progressing to cirrhosis with terminal liver failure. Each flare up presented like an acute hepatitis with very high titres of hepatitis B virus (HBV) and high inflammatory activity followed by rapid clearance of viraemia. The pre-core genome of HBV isolated from sera during 5 years of follow up was analysed. Direct sequencing of polymerase chain reaction (PCR) products derived from consecutive sera showed a rare pre-core stop-codon mutation at nucleotide (nt.) 1897 G --> A with an accompanying mutation nt. 1857 C --> T as well as a stop-cod…
Hepatitis B virus markers among family contacts of asymptomatic HBsAg carriers.
1979
A study was undertaken to establish the risk of family contacts of HBsAg carriers acquiring a hepatitis B virus (HBV) infection. About one-third of all household contacts of asymptomatic HBsAg carriers had signs of past or ongoing HBV infection. Family contacts of HBsAg carriers with high numbers of circulating Dane particles were shown to have a higher risk of developing HBV infection than family contacts of HBsAg carriers without serological evidence of HBV synthesis. The probability of acquiring HBV infection was not different between spouses, parents, children, and brothers and sisters, respectively of asymptomatic HBsAg carriers.
No detection of occult HBV-DNA in patients with various rheumatic diseases treated with anti-TNF agents: a two-year prospective study.
2013
OBJECTIVES: The widespread use of tumour necrosis factor (TNF)-targeted therapies in patients with rheumatic, digestive and dermatologic diseases has been associated with reports of reactivation of HBV replication and ensuing hepatitis flares both in asymptomatic HBsAg carriers and in subjects with occult HBV infection. The aim of our work was to investigate in a two-year prospective study the potential for HBV reactivation in patients with inflammatory joint diseases undergoing anti-TNF treatment from a southern Mediterranean area. METHODS: Fifty-seven consecutive outpatients attending the Academic Unit of Rheumatology at the University of Palermo (12 with rheumatoid arthritis, 17 with pso…
Serum hepatitis C virus (HCV)-RNA and response to alpha-interferon in anti-HCV positive chronic hepatitis
1992
Hepatitis C virus (HCV) replication was assessed before and during alpha-interferon (IFN) treatment in 22 anti-HCV positive patients with posttransfusion or sporadic chronic hepatitis (CH). Eleven patients were “responders” and 11 patients “non-responders” to IFN. Thirteen anti-HCV negative healthy subjects and five anti-HCV negative patients with autoimmune CH served as controls. Serum HCV-RNA was detected by the polymerase chain reaction (PCR) in all untreated anti-HCV positive patients but in none of the anti-HCV negative subjects. PCR primers from the 5′-non-coding (NC) region were more sensitive than primers from a non-structural (NS5) region in detecting HCV-RNA (21/22, 95% vs. 7/22, …
Characterization of non-expressed C4 genes in a case of complete C4 deficiency: identification of a novel point mutation leading to a premature stop …
1998
The genetic basis of complete C4 deficiency in a patient with SLE was investigated. Previous studies have demonstrated that this patient has two different major histocompatibility complex (MHC) haplotypes that each contain a major deletion and a non-expressed C4 gene. In the present study, non-expression of the C4 genes was explained by the finding of two distinct C4 gene mutations. A previously described two base pair insertion in exon 29 of the C4 gene was detected in the paternal MHC haplotype [HLA-A2, B40, SC00, DR6]. The maternal haplotype [HLA-A30, B18, F1C00, DR3] carried a C4 gene with a one base pair deletion in exon 20 generating a premature stop codon. This mutation was neither f…
Mutation screening for the prothrombin variant G20210A by melting point analysis with the Light Cycler system: atypical results, detection of the var…
2005
In the differential diagnosis of thrombophilic disorders genotyping of prothrombin and factor V are nowadays performed as a routine analysis. In the following we describe the unusual results of the mutation screening using melting point analysis for two patients and the consecutive detection of the mutation C20209T by sequencing the corresponding gene fragments. The molecular result is discussed with special respect to the medical history, ethnic background and clinical findings of both patients.
Natural history of cytomegalovirus infection in a series of patients diagnosed with moderate-severe ulcerative colitis
2011
AIM: To evaluate the natural history of human cytomegalovirus (HCMV) infection in a series of 28 ulcerative colitis patients in whom the search for HCMV was positive. METHODS: A series of 85 patients with moderate-severe ulcerative colitis flare-up were evaluated for a HCMV search by performing a haematoxylin and eosin stain, immunohistochemical assay and nested polymerase chain reaction on rectal biopsies. Among 85 screened patients (19 of whom were steroid resistant/dependant), 28 were positive for HCMV; after remission the patients were followed up clinically and histologically. RESULTS: Among the 22 patients with complete follow-up, in 8 (36%) patients HCMV-DNA persisted in the intestin…
Molecular basis of a new type of C1q-deficiency associated with a non-functional low molecular weight (LMW) C1q: parallels and differences to other k…
1998
Analysis of an abnormal C1q molecule of individuals of a Moroccan family by ultracentrifugation in sucrose gradients revealed a low molecular weight C1q (LMW-C1q). We investigated the molecular basis of this defect by sequencing all six exons of the three C1q genes. One point mutation in the codon for Gly at position 15 (GGT) of the B chain was found resulting in an amino acid substitution to Asp (GAT). The exchange not only leads to an interruption of the collagen-like motif Gly-X-Y, but also introduces one negatively charged residue per B chain which results in two additional charges per structural subunit (A-B, C-C, A-B). The mutation which has been identified by DNA-sequencing in the C1…
Differential association of polymorphisms in the TNFalpha region with psoriatic arthritis but not psoriasis.
2002
To investigate the potential association of tumour necrosis factor alpha (TNFalpha) microsatellite and promoter alleles with psoriatic arthritis (PsA).DNA from 89 white patients with PsA, 65 patients with psoriasis, and 99 healthy white controls was investigated for two TNFalpha promoter (-238 and -308) and three microsatellite polymorphisms (TNFa, c, and d). Patients had previously been studied by serology for HLA class I antigens and by sequence-specific polymerase chain reaction for DRB1* alleles. In addition, TNFalpha production of Ficoll separated peripheral blood mononuclear cells (PBMC) into culture supernatants after stimulation with lipopolysaccharide, alphaCD3 antibodies, phytohae…
Preferential splenic CD8+ T-cell activation in rituximab-nonresponder patients with immune thrombocytopenia
2013
The pathogenic role of B cells in immune thrombocytopenia (ITP) has justified the therapeutic use of anti-CD20 antibodies such as rituximab (RTX). However, 60% of ITP patients do not respond to RTX. To decipher the mechanisms implicated in the failure of RTX, and because the spleen plays a well-recognized role in ITP pathogenesis, 12 spleens from ITP patients who had been nonresponders to RTX therapy were compared with 11 spleens from RTX-untreated ITP patients and 9 controls. We here demonstrate that in RTX-nonresponder ITP patients, preferential Th1 and Tc1 T lymphocyte polarizations occur, associated with an increase in splenic effector memory CD8(+) T-cell frequency. Moreover, in the RT…