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T E Ivashchenko

Publications and source records attributed to T E Ivashchenko.

33 records · Page 2Linked to original sources
PubMed1993

[A simple and reliable method for detection of the R408W mutation in exon 12 of the phenylalanine hydroxylase gene in the molecular diagnosis of phenylketonuria].

A new method for identification of R408W mutation common in phenylketonuria (PKU) patients in Russia and Eastern Europe is presented. The method is based on restriction of amplified exon 12. Amplification was achieved by PCR and was followed by restriction with StyI endonuclease. This enzyme specifically recognized allele R408W (C-T change in the position 1444 of the PAH gene) but not the normal allele. The method is easily reproduced both in DNA samples and in blood spots on the blotting paper (Gathrie cards) as well as in native cells from chorionic villi samples and amniocytes without preliminary DNA extraction. The method is very reliable and quick and has obvious advantages over other methods (ASO, ARMS) routinely used for identification of R408W mutation in the PKU high risk families.

Alleles↗
PubMed1992

[Molecular-genetic analysis of tandem repeats in intron 6B of the CFTR gene in various populations and in cystic fibrosis patients].

Frequencies of hexa- and heptatandem tetrameric repeats in Russian slavonians from the North-Western part of the country were found to be 0.19 and 0.81, respectively, with the frequency of heterozygotes estimated as 0.31. Similar values of allelic frequencies were found for uzbek and azerbaijan populations (0.24 and 0.76; 0.22 and 0.78, respectively). These data assess the existence of genetic equilibrium of both alleles in the populations studied. Hexa TTR is present twice more often in the CF chromosomes than hepta TTR common for normal chromosomes. Absolute genetic disequilibrium of both TTR alleles was observed for CF chromosomes bearing the F508 mutation. The latter was exclusively detected in a conjunction with hexa TTR allele. Combined application of the F508 test and TTR alleles assay significantly increased the number of totally informative CF-high risk families, and thus might be highly beneficial for a subsequent prenatal diagnosis of CF.

Alleles↗
PubMed1991

[Complex biochemical and molecular approach to prenatal diagnosis of mucoviscidosis].

Prenatal diagnosis of 62 cases of cystic fibrosis was performed in high-risk families at 18-21 gestational weeks using biochemical and molecular tests. The diagnosis was ruled out in 42 and confirmed in 20 cases. The incidence of false-positive results was 8.3% (5 of 62) and that of false-negative results 3.7% (2 of 62). Reliability of prenatal diagnosis in concomitant use of biochemical and molecular tests was over 95%. Advantages of prenatal diagnosis of cystic fibrosis using DNA probes and requirements for its wider adoption in the first trimester are discussed.

Acid Phosphatase↗
PubMed1991

[Allele polymorphism of the DNA loci MET, D7S8, D7S23, linked to the cystic fibrosis gene in some populations of the USSR, in high risk families and in cystic fibrosis patients].

RELP analysis of DNA loci MET, D7S8 and D7S23 was carried out in Leningrad population and partially in populations of Moscow, Azerbaijan, Ukraine, Buryatia as well as in individuals from high risk families and in cystic fibrosis (CF) patients by means of blot hybridization and polymerase chain reaction. Allelic polymorphism of all loci studied in these three groups was found to be quite similar to that in the North-Western Europe and in whites of the North America. Linkage disequilibrium of the alleles studied with the CF gene was especially pronounced for alleles of the D7S23 locus and gradually decreases from KM-19 through CS-7 to XV-2c DNA probes. The data witness genetic homogeneity of the CF mutation in European populations of the USSR and its similarity to this mutation in Western Europe. The significance of these data for potential diagnosis of CF and for heterozygous carrier detection is discussed.

Alleles↗
PubMed1990

[Cytologic diagnosis of recurrences of epithelial tumors of the bladder].

The cytologic method for urinalysis is available, inexpensive, and permits multiple examinations over the course of treatment. Cytologic analyses of the urine in 300 patients with bladder tumors have revealed relapses after the course of treatment in 30 cases, no clinical symptoms being detectable. A trefoil-shaped grouping of cells in cytologic preparations was found to be characteristic of transitional-cell papilloma and therefore fit to serve as a diagnostic sign. Cellular polymorphism is not so manifest in bladder carcinoma relapses, though the cells essentially differ from those of transitional-cell papilloma. Therefore, cytologic analysis of the urine is an effective method for the diagnosis of epithelial tumors of the bladder.

Carcinoma↗
PubMed1990

[Polymorphism of nucleotide sequences of human genomic DNA linked to a mucoviscidosis locus].

Polymorphism in the restriction fragments length of human DNA sequences linked to mucoviscidosis locus was studied in the healthy control group and in the families affected by mucoviscidosis. The plasmid clones metH, pJ3.11,XV-2c and pKM.19 were used as hybridization probes. The allelic frequencies of the polymorphic loci were determined for total population and for affected families. The linkage disequilibrium between the disease locus and linked polymorphic loci detectable with XV-2c (TaqI endonuclease) and pKM.19 (PstI endonuclease) was demonstrated. The high informational value of DNA-diagnosis of mucoviscidosis in the family studies with the use of four DNA probes combination has been demonstrated.

Cystic Fibrosis↗
PubMed1990

[Use of molecular and genetic approaches in prenatal diagnosis and prevention of hemophilia A and Duchenne muscular dystrophy].

Allele polymorphism has been evaluated using blot hybridization and a polymerase cascade of DNA synthesis in 40 families at high risk of hemophilia A (a total of 147 subjects) and in 15 families with Duchenne's myodystrophy, Heterozygous carriage of hemophilia A was identified or confirmed in 18 and ruled out in 4 close female relatives of probands. Prenatal tests for fetal hemophilia A were performed in 5 women from families with hemophilia A (in the 1st trimester in 2 and in the 2nd trimester in 3). Four diagnoses of hemophilia A were confirmed and 1 was ruled out. The DNA methods proved revealing in 34 of 40 families with hemophilia A and in 11 of 15 families with Duchenne's myodystrophy. Three of 9 probands were found to have a deletion of the proximal gene for Duchenne's myodystrophy in the DNA probe area of XY 1.1. Prospects of screening for heterozygous carriage and prenatal identification of hemophilia A and Duchenne's myodystrophy are discussed.

Chorionic Villi Sampling↗
PubMed1990

[The importance of medical genetics study for the early diagnosis of mucoviscidosis].

The method of specific DNA amplification was used to study the polymorphism of the length of restriction fragment in the system CS-7 and KM-19 locus D7S23 in the family C. It is shown that cohesion of alleles A2 and B2 with mutation of mucoviscidosis and presence of a mucoviscidosis gene occurred in a healthy sibling. The family C, is prospective for prenatal diagnosis of mucoviscidosis by the method of specific DNA amplification in the system KM-19 restrictase Pst-1 and CS-7-Hinf-6-1.

Chromosomes, Human, Pair 7↗
PubMed1989

[Detection of the heterozygote carrier state and prenatal diagnosis of hemophilia A using DNA probes].

Southern blot analysis of DNA samples from 110 persons related to 30 high risk hemophilia A families was carried out using intergenic probe St-14 and intergenic probes p 51-61 and p 1.8. Thirty-five hemophilia A patients, 24--their mothers--obligatory carriers and 51 close proband relatives were studied altogether. 16 female proband relatives were diagnosed as hemophilia A carriers, hemophilia A heterozygosity was rejected in three persons. Twenty five families were found to be at risk for prenatal hemophilia A diagnosis. One case of hemophilia A diagnosis in a 10-week fetus has been presented.

Blotting, Southern↗
PubMedDate not supplied

[Suppression of nonsense mutations in the Dystrophin gene by a suppressor tRNA gene].

Nonsense mutations in the dystrophin gene are the cause of Duchenne muscular dystrophy (DMD) in 10-15% of patients. In such an event, one approach to gene therapy for DMD is the use of suppressor tRNAs to overcome the premature termination of translation of the mutant mRNA. We have carried out cotransfection of the HeLa cell culture with constructs containing a suptRNA gene (pcDNA3suptRNA) and a marker LacZ gene (pNTLacZhis) using their polymer VSST-525 complexes. It was found that the number of cells producing beta-galactosidase depends inversely on the dose of the suptRNA gene. A single in vivo injection of the construct providing for expression of the suptRNAochre gene into mdx mouse muscle resulted in the production of dystrophin in 2.5% of fibers. This suggests that suppressor tRNAs are applicable in gene therapy for hereditary diseases caused by nonsense mutations.

Animals↗
PubMedDate not supplied

[The mutation spectrum of the CFTR gene in mucoviscidosis patients from Bashkortostan].

Mutations of CFTR were studied in patients with cystic fibrosis (CF) from Bashkortostan. In total, 15 mutations were observed and 51% of all mutant alleles identified. The most diagnostically significant mutations were delF508 (33.8%), 394delTT (3.52%), CFTRdele2.3(21 kb) (1.41%), R334W (1.41%), 3849+ 10 kbC-->T (1.41%), and N1303K (1.41%). Mutations G542X, 2184insA, S1196X, and W1282X were each found in less than 1% patients. Five new mutations and two neutral substitutions were revealed. These were I488M (exon 10), 1811 + 12A-->C (intron 11), T663S (exon 13), I1226R (exon 19), 4005 + 9A-->C (intron 20), 2097A-->C (A655A, exon 13), and 3996G-->C (V1288V, exon 20). Bashkortostan was shown to differ in CFTR mutation spectrum from other regions of Russia. The results will allow direct DNA diagnostics of CF in far more families. Molecular screening of probands' relatives will contribute to identification and medical genetic counseling of heterozygous carriers, which is essential for CF prevention.

Bashkiria↗
PubMedDate not supplied

[Biochip development for polymorphism analysis in biotransformation system genes].

Large-scale population researches, diagnostics of genetic predisposition to multifactorial diseases, screening of the polymorphic loci associated with individual sensitivity to pharmaceutical preparations, require the development of effective, exact and rapid methods of analysis for detection of many mutations simultaneously. One of the most perspective methods to solve these problems is a method of allele-specific hybridization with biochips. Taking the analysis of mutations in genes CYP1A1, CYP2D6, GSTM1, GSTT1, NAT2, CYP2C9, CYP2C19 and MTHFR as an example we showed the efficiency of using the approach for identification of individual genetic polymorphism. We believe that the biochips can be also a convenient tool in pharmacogenetics researches.

Biotransformation↗