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I A Smirnova

Publications and source records attributed to I A Smirnova.

51 records · Page 3Linked to original sources
PubMedDate not supplied

[Cytogenetic changes in the Namalwa cell line of human malignant lymphoma induced by inhibitors of DNA replication and synthesis].

Namalwa cells originating from the malignant human lymphoma have been analyzed cytogenetically upon short-time exposure to subtoxic doses of inhibitors of DNA replication and synthesis, either etoposide or fludarabine. The intact cells were characterized by the modal class of the chromosomes within the diploid range with the proportion of the aberrant cells amounting to 16.0 +/- 0.5%. Upon exposure to etoposide the percentage of the aberrant cells increased amounting to 26.1 +/- 2.9 through 39.8 +/- 1.7% depending on the duration of the exposure and the dose of the drug. At the same time the number of the polyploid cells increased but the modal class retained within the diploid range. Upon exposure to fludarabine the percentage of the cells with the aberrant chromosomes increased to 57.1 +/- 2.9%. Two modal classes appeared--the first approaching the diploid number and the second being polyploid. The exposure to either etoposide or fludarabine resulted in increasing number of the chromatide aberrations with more frequent involvement of #1, #2, #5, #6, #7, #11, #13, #14, #16 and #17 chromosomes. The data obtained have shown the susceptibility of Namalwa cells to the subtoxic concentrations of the inhibitors of DNA synthesis and replication used in the study resulting in the survival of the novel clones resistant to the drugs.

Cell Line, Tumor↗
PubMedDate not supplied

[Computed tomography in the diagnosis of complications in the early postoperative period in patients with tumors of the posterior cranial fossa].

The authors analyse the results of clinico-CT studies in complicated course of the early postoperative period in 104 patients (87 adults and 17 children) with tumors of the posterior cranial fossa (PCF). According to the histological structure and predominant topography of the neoplasm, the cases were divided into 46 extracerebral parastem tumors (meningiomas, neurinomas, chordomas, cholesteatomas) among which 24 extended supratentorially and 22 to Blumenbach's clivus; 23 gliomas of the cerebellum and fourth ventricle; 16 primary gliomas of the stem; 19 other new growths (hemangioblastomas, hamartomas, choroid papillomas, germinomas). A common factor was coexistence of the main complicating condition--circulatory disorder in the stem with edema and dislocation of the stem, disturbed spatial relations between the PCF structures. Dynamic CT studies allowed the authors to differentiate 3 main variants of pathological changes differing in the character of cerebral circulatory disorders: 1st--a wide zone of reduced density in the brain stem; the extent of this zone in the orocaudal direction and its relation to the diameter of the stem (dorsal, ventral, lateral parts) varied; 2nd--combination of zones of reduced density in the stem and cerebellum with hemorrhagic inclusions--multiple "punctate" inclusions or in the form of blood clots; 3rd--in mosaic pattern of the ischemic foci in the stem and cerebellum there was a prevalence of hemorrhages in the form of multiple small extravasations of blood at different levels of the stem, in the subcortical parts, blood clots in the seat of the tumor, hemotamponade of the brain ventricles.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMedDate not supplied

[Somatic mutagenesis at T-cell receptor locus in inhabitants of radiation polluted regions as a result of the Chernobyl disaster].

In the period of 2001-2004, frequency of cells bearing mutations at T-cell receptor (TCR) locus was assessed in 553 inhabitants of radiation polluted regions of the Russian Federation and 154 unexposed control persons. The inhabitants were divided into three groups according to age at the moment of the Chernobyl disaster and 137Cs pollution density: 1) in utero, 37-555 kBq/m2; 2) 0-14 years old, 20-555 kBq/m2; 3) 18 and more years old, highest 137Cs density (185 more than 555 kBq/m2). The most intense changes of the TCR-mutant cell frequency were observed in the group of persons exposed to ionizing radiation in utero. The mean frequency of the mutant cells was higher in the first group than in age-matched control group by about 1.5-fold: 4.0 x 10(-4) vs 2.7 x 10(-4) accordingly (p < 0.0001). Elevation in the mean TCR-mutant cell frequency was less expressed in group of inhabitants aged 0-14 years at the moment of irradiation start: 1.3-fold increase in comparison to age-matched control (3.8 x 10(-4) vs 2.9 x 10(-4), p = 0.0002). It was not found significant differences in mutant cell frequencies between control group and adults consisting in the third group (18 and more years old at the moment of the Chernobyl accident). The changes of the TCR-mutant cell frequency in persons exposed in pre- and postnatal periods differ not only quantitatively, but qualitatively. In the fist case all persons react to irradiation by increasing number of the TCR-mutant cells in some degree. In the second case - only a part of population. Proportion of reacting persons depends on age at the start of irradiation and, perhaps, on dose absorbed. The TCR-mutant frequency was significantly higher in persons with benign tumors of different localizations and nodules in thyroid gland than in persons without this pathology.

Chernobyl Nuclear Accident↗
PubMedDate not supplied

[Free radical centers in the chromatophores and preparations of Rhodospirillum rubrum reaction centers].

The light-induced free radical ESR signals in chromatophores and reaction center preparation of R. rubrum were studied. It has been shown that the properties of the signals in both systems were strictly identical. At the microwave powers higher than 10 mW the ESR signal at g approximatley 2.00 is saturated and its asymmetry arises. Changes of the ESR signal shape may be explained by the superposition of P870+ signal with that from the ubisemiquinone. Addition of ferricyanide to chromatophores induces in the dark a new ESR signal characterized by a linewidth of 4.5 Oe which presumably arises from the antenna bacteriochlorophyll aggregates, because this signal is absent in the reaction center preparations.

Bacterial Chromatophores↗
PubMedDate not supplied

[Polyadenylated RNA and poly-A segments in the splenic cells of mice with virus-induced Rauscher leukemia].

In spleen cells of mice with Rauscher++ leukosis polyadenilation of RNA was impaired: an increase in content of Gya poly(A)+ RNA and a change in the composition of poly-A-segments were observed. In DNA of leukemic and normal cells dA-fragments were found content of which was increased in leukemic cells as compared with normal ones. Leukemic transformation appears to be accompanied by appearance of the additional poly-A-fragments in the cells.

Animals↗
PubMedDate not supplied

[Kinetics of the generation of a photo-induced electric potential in chromatophores of photosynthetizing bacteria].

Flash-induced formation of an electric potential difference (delta psi) was monitored by a direct method in chromatophores associated with the collodion phospholipid membrane. In Rhodospirillum rubrum and Rhodopseudomonas sphaeriodes chromatophores, the kinetics of delta psi generation exhibit fast (tau less than or equal to 0.3 microseconds) and slow (tau congruent to 200 microseconds) phases, the latter observed in the presence of exogenous quinones. Comparison of the kinetic and potentiometric characteristics of the process with those of electron transport reactions suggests that the fast phase of delta psi rise is due to charge separation between the primary electron donor, P870, and primary electron acceptor QIFe; the slow phase, which is inhibited by o-phenanthroline, is due to electron donation from QIFe to the secondary acceptor, quinone QII. The kinetics of delta psi decay include components arising form the recombination of primary separated charges (tau congruent to 30 ms) and from the passive discharge of the membrane (tau congruent to 400 ms; tau congruent to 1400 ms). From a redox titration of the photo-induced electric signal and the photo-induced absorption changes of P870 at different pH meanings, the value of pK for the primary acceptor FeQI was found to be 7.4 in Rps. sphaeroides chromatophores. In Chromatium minutissimum, a phase ( tau congruent to 20 microseconds) was observed in addition to those seen in Rps. sphaeroids and R. rubrum which was explained by the reduction of P890+ from the high potential cytochrome c555. Possible distribution of the electron transport components in the chromatophore membrane are discussed.

Bacterial Chromatophores↗
PubMedDate not supplied

[Characteristics of metabolism in fast-labelling nuclear RNA spleen cells of mice with Rauscher leukemia].

A component of quickly labelling D-RNA with a sedimentation coefficient of 35 S is revealed in spleen cell nuclei of mice infected with the leukemogenic Rauscher virus. The component is absent in healthy animals. It is labelled for 5 min of incubation with the label and under conditions of chase experiment disappears from the nucleus 2 h later differing from the rest of leukemic cell D-RNA in a higher metabolic activity. [3H] RNA with a sedimentation coefficient of 35 S is detected in cytoplasm of RNA synthetizing in leukemic cells under the effect of leukemogenic virus. It is the RNA of messenger type though it seems possible that a part of it remains in the nucleus and performs intranuclear functions.

Animals↗
PubMedDate not supplied

[Effect of histone H5 on the development of virus-induced leukemia and RNA synthesis in leukemic cells].

Development of virus-induced Rauscher leukosis was studied after administration into mice of histone H5 isolated from chicken erythrocyte nuclei by means of gel filtration through Sephadex G-75. Histone H5, administered intraperitoneally at a dose of 100 mg/kg into mice treated with Rauscher virus, inhibited the leukosis development (T = 29.7%). Inhibitory effect of histone H5 on synthesis of 35S RNA, characteristic for leukemic cells, was found. The most distinct efficiency of the histone was exhibited within early periods of the infection in experimental animals.

Animals↗
PubMedDate not supplied

[Expression and function of x-mla genes associated with leukemic transformation of cells].

Expression of genes, associated with leukemic transformation and called x-mla, was studied in cells of various types of experimental leukemia and in homologous normal cells. Augmentation of x-mla expression in malignant haemopoietic cells and lack or very low expression in normal tissues and non-haemopoietic tumors of mice and rats has been revealed. The involving of x-mla in proliferation control of leukemic but not normal cells has been shown. Product of x-mla--p46 was synthesized in cell-free translational system and purified. Its amino acid composition was determined and its mitogenic, RNAase activities, and ability to phosphorylation have been investigated.

Amino Acids↗
PubMedDate not supplied

[Genomic disorders in the mononuclear blood cells of those who worked in the cleanup of the accident at the Chernobyl Atomic Electric Power Station].

The results of molecular investigations of blood mononuclears from 120 clean-up workers after 7-9 years of Chernobyl accident with the total exposure radiation doses ranging from 5 to 76 cGr are presented. Structural polymorphism of the leukemia associated bcr and ribosomal RNA (rRNA) genes were studied using Southern blot hybridization. Allelic polymorphism of bcr gene with characteristic for leukemia allele distribution was detected in 16.6%. Rearrangements of rRNA genes were observed in 13% of Chernobyl accident clean-up workers.

Alleles↗
PubMedDate not supplied

[The viral genome status studied under the conditions of a mixed infection in lymphoblastoid cells by adenovirus and the Epstein-Barr virus].

Some indices have been studied which characterized the state of Epstein-Barr virus genome and adenovirus in the implanted lines of lymphoblastoid cells of B and T phenotype under the mixed or monoinfection. It has been shown that super infection by type 2 adenovirus rather sharply affects the state of Epstein-Barr virus genome in the Raji cells containing integrated Epstein-Barr virus genome. The state of adenovirus genome in the studied cells is less subject to changes. Its early area is revealed by hybridization using DNA-DNA method in a form of two fragments of different intensity which is maximum in the Raji and Jurkat cells, which evidences for the more expressivity of adenovirus genome in these cells.

Adenovirus Infections, Human↗