Search results for "Strand"
showing 10 items of 222 documents
Genotype and phenotype analysis of Friedreich's ataxia compound heterozygous patients
2000
Friedreich's ataxia is caused by mutations in the FRDA gene that encodes frataxin, a nuclear-encoded mitochondrial protein. Most patients are homozygous for the expansion of a GAA triplet repeat within the FRDA gene, but a few patients show compound heterozygosity for a point mutation and the GAA-repeat expansion. We analyzed DNA samples from a cohort of 241 patients with autosomal recessive or isolated spinocerebellar ataxia for the GAA triplet expansion. Patients heterozygous for the GAA expansion were screened for point mutations within the FRDA coding region. Molecular analyses included the single-strand conformation polymorphism analysis, direct sequencing, and linkage analysis with FR…
Blood levels of nitric oxide and DNA breaks assayed in whole blood and isolated peripheral blood mononucleated cells in patients with multiple sclero…
2019
Abstract Oxidative stress, especially overproduction of nitric oxide (NO), is considered to be one of the crucial factors in the pathogenesis of multifactorial multiple sclerosis (MS). DNA breaks could be one of the consequences of oxidative stress; however, data on DNA breakage in MS are very few and contradictory. There are no data on direct measurements of NO production in the blood of MS patients. The goal of this study was to determine the level of single-stranded DNA breaks in whole blood or isolated peripheral blood mononuclear cells (PBMNCs) by means of alkaline single cell gel electrophoresis (comet assay) and to evaluate production of NO in the human blood by applying electron par…
Increasing rates of DNA single-strand breaks in lymphocytes of clinical personnel handling cytostatic drugs
1993
A total of 27 persons, working in cancer stations with exposure to cytostatics, and 40 healthy control persons were examined for DNA single-strand breaks in peripheral lymphocytes. Non-smoking personnel from cancer stations were found to have an increased rate of DNA single-strand breaks compared to the non-smoking control subjects. In the case of smokers an increased rate of DNA single-strand breaks could be recorded for those working in cancer stations as well as with the controls. DNA single-strand breaks indicate reversible damage to DNA. As DNA repair is not perfect in every case, an increased number of DNA single-strand breaks leads to irreversible DNA damage.
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…
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…
Evaluation of clinical diagnosis criteria of familial ligand defective apoB 100 and lipoprotein phenotype comparison between LDL receptor gene mutati…
2007
Familial hypercholesterolemia (FH) and familial defective apoB 100 (FDB) are characterized by increased plasma low-density lipoprotein cholesterol (LDLc) levels and risk of coronary heart disease (CHD). FDB is clinically indistinguishable from FH. The aims of this study were to evaluate clinical diagnosis criteria for FDB and to compare the lipoprotein phenotype between carriers of LDL receptor (LDLR) gene mutations that affect the ligand-binding domain and subjects with the R3500Q mutation in apoB gene. We studied 213 subjects (113 probands) with FH and 19 heterozygous FDB subjects. Genetic diagnosis was determined by following a protocol based on Southern blot and polymerase chain reactio…
Molecular analysis of the erythropoietin receptor system in patients with polycythaemia vera
1994
Summary Erythropoietin (EPO) is a potent regulator of the viability, proliferation and differentiation of erythroid progenitor cells. Its effect is mediated by binding to the erythropoietin receptor (EPO-R), a member of a new cytokine receptor family. Alterations of the EPO/EPO-R system have recently been shown to be involved in the pathogenesis of familial erythrocytosis and polycythaemia vera (PV). In order to define whether genetic changes in the EPO-R gene and its ligand play a role in the development of PV, the structure and expression levels of the EPO-R and EPO genes were examined in samples from bone marrow and/or peripheral blood mononuclear cells of 24 patients with PV. As expecte…
Gly114Asp mutation of rhodopsin in autosomal dominant retinitis pigmentosa
1995
Two autosomal dominant retinitis pigmentosa families of different origin were screened for rhodopsin mutations using the method of single strand conformation polymorphism and direct sequencing. We found a CGG-CAG substitution in codon 114 of rhodopsin in both families. This change predicted the replacement of a glycine by an aspartic acid and suggested that this change is the cause of the disease in these families.
DNA single strand break analysis in mononuclear blood cells of petrol pump attendants
1995
DNA single strand breaks, including DNA adducts that lead to alkali-labile sites, were measured in peripheral mononuclear blood cells of 35 petrol pump attendants by alkaline filter elution. Blood samples from petrol pump attendants were taken on Monday and Friday. Additionally, DNA single strand breaks of smoking and non-smoking control persons were examined. For the smoking (n = 12) and the non-smoking controls (n = 20) a mean normalized elution rate of 1.49 +/- 0.52 (mean value +/- 95% confidence interval) and 1.32 +/- 0.28, respectively, was obtained. The difference between smoking and non-smoking controls was not statistically significant (U test). An increase in DNA single strand brea…