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T I Solov'eva

Publications and source records attributed to T I Solov'eva.

17 recordsLinked to original sources
PubMed2004

[Detection of YMDD mutations in hepatitis B virus DNA with the use of allele specific polymerase chain reaction].

Antiviral drug lamivudine has been widely used in the treatment of hepatitis B. However, it was demonstrated recently, that therapy by the drug is related with the selection of viral strains carrying mutations in C-domain of DNA polymerase/reverse transcriptase (YMDD-mutation). The mutation is the cause of resistance to lamivudine. An increase of the mutant population in the course of a long-term lamivudine therapy makes the monotherapy by the discussed drug ineffective. Therefore, the monitoring of YMDD mutations is important in the treatment of chronic hepatitis B (CHB) by lamivudine. The results of using the allele-specific polymerase chain reaction (AS PCR) for the detection of YMDD mutations are presented in the offered case study. Sera from CHB patients were used in research. A system of allele-specific primers was designed for the HBV DNA region from base 720 to base 978, which enabled us to detect possible substitutions in an appropriate ATG-triplet, i.e. the YMDD-mutations locus--positions 741-743 of the HBV DNA nucleotide sequence. The obtained DNA fragments were analyzed by electrophoresis in the agar gel. AS PCR was used to test the sera of HBV patients. Samples were detected, which contained the "wild" virus type, different YMDD mutations and mixed (the "wild" type plus a mutation) HBV variants. It was shown that reliable AS PCR results could be obtained only in those sample, whose HBV titer is no more than 10(6) genome per ml. The offered AS PCR procedure can be applied in the detection of YMDD mutations of HBV DNA in sera of patients with hepatitis B. Sera with a high virus titer must be diluted, prior to testing, to 10(6) genomes per ml. to ensure the reliable AS PCR results.

Alleles↗
PubMed2004

[Wilson's disease and secondary copper hemochromatoses in hematological practice].

AIM: To characterize clinical, diagnostic and therapeutic syndromes of copper overloading in patients with hepatic lesion in combination with hemopoietic disorder. MATERIAL AND METHODS: Treatment results and diagnostic findings are presented for patients with clinical picture of liver cirrhosis, cytopenia and copper overloading. The examination included standard clinical and specific tests, morphological investigation of the bone marrow, copper metabolism in dynamics. RESULTS: A case of a patient is reported in whom Wilson's disease presented in debut with a picture of decompensated liver cirrhosis and immune thrombocytopania complicated by recurrent hemorrhagic syndrome. D-penicillomine treatment initiated ex juvantibus allowed verification of the diagnosis of Wilson's disease and achievement of marked clinical response. In another case laboratory signs of copper overloading were revealed in a patient with liver cirrhosis of viral etiology (HBsAg+) and deep cytopenia associated with uneffective hemopoiesis. Chelator therapy with D-penicillamine regressed cytopenic syndrome and improved functional capacity of the liver. CONCLUSION: Primary or secondary nature of copper overloading in patients with hepatic cirrhosis and critical cytopenia, pathogenesis of cytopenic syndrome, practical significance of copper hemochromatoses diagnosis are discussed.

Adult↗
PubMed1995

[Origin and properties of Pseudomonas aeruginosa PAO1 clones surviving after induction of prophages-transposons].

Various mutations cancelling the lethal effect of phage lytic development and simultaneous phenotypic modifications were found in rare clones surviving after incubation at 42 degrees C of Pseudomonas aeruginosa (D3112 cts 15), lysogenic for thermoinducible mutant cts 15 of the transposable prophage (TP) D3112. All mutations arose prior to thermal induction. Temperature induction of other bacteriophages (nontransposable) did not lead to selection of bacterial morphological mutants. Therefore, it was concluded that mutagenesis occurred upon the partial (reversible) TP derepression accompanied by coupled replication-transposition of TP, the latter being the direct cause of the mutator effect. Isolation of the P. aeruginosa PAO1 mutant R10 (this mutant is resistant to infection with TP at 42 degrees C) allowed the proper selection and examination of numerous survivors. Comparison of their types derived from lysogens with different prophage location indicated that the number of secondary sites where TP integration is possible without the loss of cell viability is limited. Several transposition events occurred in the history of some survivors (during a repeated or single derepression event). Type D clones, which produce small colonies, are of special interest, because mechanisms underlying the survival of such clones are extremely diverse, and their phenotypes indicate the possibility of stable chromosomal rearrangements in the genome of P. aeruginosa.

Cloning, Molecular↗
PubMed1995

[Mucoid clones of Pseudomonas aeruginosa PAO1, surviving after induction of prophage transposons].

The origin and properties of mucoid clones were studied. The clones were selected with high frequency after thermo-induction of Pseudomonas aeruginosa lysogenic for phage transposons (PT). The production of alginate does not promote the survival of lysogenic bacteria at 42 degrees C. Mucoid clones were shown to appear before thermo-induction; the frequency of their formation does not depend on the specificity of the mutator effect intrinsic to different PT. Phenotypic differences typical of mucoid clones can be mediated by different mutations promoting clone survival at 42 degrees C and by simultaneously arising additional mutations. The SL21 mucoid clone selected among clones of P. aeruginosa PAO1 resistant to PT of B3 possesses an additional trait of phage resistance at 42 degrees C. The presence of D3112 cts 15 prophage has no significant effect on the frequency of SL21 reversion to nonmucoidness. This means that the mutator effect of PT has made a slight contribution to this process. The appearance of mutations promoting the survival of the thermoinducible lysogen SL21 (D3112 cts 15) does not affect the frequency of the loss of mucoidness. Nonmucoid derivatives of SL21 were shown to differ in phage resistance at 42 degrees C and in the extent of the residual mucoidness manifested under specific conditions. Consequently, nonmucoid clones appear as a result of pseudo-reversions. Because some of these pseudo-revertants cannot again be converted to the mucoid form, it is concluded that they carry mutations in genes whose functions are obligatory for the production of alginate.

Alginates↗