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Biomedical subjects

T A Smirnova

Publications and source records attributed to T A Smirnova.

At least 19 recordsLinked to original sources
PubMed2006

[Clinical and laboratory evidence for effectiveness of whitening toothpastes].

The article presents clinical and laboratory data concerning application of whitening toothpastes "Rembrandt". The effects of these pastes on the soft tissues status, the content of mineral substances in enamel biopsy liquid, enamel surface were evaluated. The results confirm the necessity of differential application of agents for tooth whitening and also of using whitening toothpastes for improvement of teeth color.

Data Interpretation, Statistical↗
PubMed2004

H1 histone in developing and aging coleoptiles of etiolated wheat seedlings.

It has been established that the DNA and H1 histone contents in aged coleoptile of 8-day-old etiolated wheat seedling are about 40 and 30%, respectively, lower than those in young seedlings. H1 histone in wheat seedlings is represented as six electrophoretically different subfractions. The ratios of H1 histone subfractions in wheat coleoptile and initial leaf are similar. In contrast to some animal cells, apoptosis in wheat coleoptile is not accompanied by changes in the set and ratios of H1 histone subfractions. Aging of coleoptiles is associated with a progressive diminution of the H1 histone and DNA contents. H1 histone/DNA ratio in aged coleoptile is 1.5-2-fold higher than that in the young organs. Therefore, the content of H1 histone in chromatin of coleoptile decreases with age more slowly than DNA content.

Apoptosis↗
PubMed2002

Oxidative modification of proteins: oxidation of tryptophan and production of dityrosine in purified proteins using Fenton's system.

Specific features of metal-catalyzed oxidation (MCO) of purified proteins (human serum albumin and human erythrocyte superoxide dismutase) were analyzed by the oxidation level of tryptophan and tyrosine. The production of dityrosine cross-links and the oxidation of tryptophan residues were recorded by fluorescence. The degree of oxidative modification of the amino acid residues of the proteins depended on the concentration of the Fenton's medium components and on the incubation time. These changes were different in different proteins. By electrophoresis and gel-permeation chromatography, changes in the superoxide dismutase structure are shown to be caused by oxidative modification of the enzyme and to be accompanied by a decrease in its activity. Findings with OH* scavengers (mannitol and ethanol) suggest that oxidative modification of the proteins in Fenton's medium should be associated not only with hydroxyl radical but also with ferryl and perferryl ions and with the radical CO(-.)(3).

Albumins↗
PubMed2000

Divalent metal cation binding properties of human prothymosin alpha.

The divalent cation binding properties of human prothymosin alpha, an abundant nuclear protein involved in cell proliferation, were evaluated. By using prothymosin alpha retardation on a weak cation chelating resin charged with various divalent cations, specific binding of Zn2+ ions by prothymosin alpha was observed. This finding was further confirmed by the equilibrium dialysis analysis which demonstrated that, within the micromolar range of Zn2+ concentrations, prothymosin alpha could bind up to three zinc ions in the presence of 100 mM NaCl and up to 13 zinc ions in the absence of NaCl. Equilibrium dialysis analysis also revealed that prothymosin alpha could bind Ca2+, although the parameters of Ca2+ binding by prothymosin alpha were less pronounced than those of Zn2+ binding in terms of the number of metal ions bound, the KD values, and the resistance of the bound metal ions to 100 mM NaCl. The effects of Zn2+ and Ca2+ on the interaction of prothymosin alpha with its putative partners, Rev of HIV type 1 and histone H1, were examined. We demonstrated that Rev binds prothymosin alpha, and that prothymosin alpha binding to Rev but not to histone H1 was significantly enhanced in the presence of zinc and calcium ions. Our data suggest that the modes of prothymosin alpha interaction with Rev and histone H1 are distinct and that the observed zinc and calcium-binding properties of prothymosin alpha might be functionally relevant.

Calcium↗
PubMed1998

Insecticidal activity of Bacillus laterosporus.

The Bacillus laterosporus strains 921 and 615 were shown to have toxicity for larvae of the mosquitoes Aedes aegypti, Anopheles stephensi, and Culex pipiens. The larvicidal activity of B. laterosporus was associated with spores and crystalline inclusions. Purified B. laterosporus 615 crystals were highly toxic for Aedes aegypti and Anopheles stephensi.

Aedes↗
PubMed1998

[Primary anodontia in X-linked hidrotic ectodermal dysplasia].

Nine patients with congenital deciduous and permanent adentia are described for the first time in Russia. Published reports are reviewed and recommendations on the DNA and prenatal diagnosis offered, which permit detecting women at a high risk of giving birth to handicapped children.

Adult↗
PubMed1998

[Ethic aspects of conducting physiological-hygienic and psychological studies on human subjects as applied to the activities in extreme environments].

The paper deals with ethic concerns of biomedical research involving human subjects aimed at mitigating risks for and raising the effectiveness of humans in extreme environments. Cited are the main principles of the Nuremberg Code, Helsinki Declaration, Convention of the European Council on Bioethics and other international and national documents regulating ethic implementation of research with participation of human subjects. The 6-year experience of the Bioethics Commission convened at SRC RF--IBMP is summarised.

Environmental Exposure↗
PubMed1996

The crystal-forming strains of Bacillus laterosporus.

Bacillus laterosporus is a spore-forming bacterium characterized by its ability to produce a canoe-shaped lamellar parasporal inclusion, adjacent to the spore. In some B. laterosporus strains crystalline inclusions of various shapes and sizes, which are released separately from spores during the lysis of the sporangium, were also produced. The morphological characteristics of two crystal-forming strains, B. laterosporus BL 16-92 and LAT 006, were investigated.

Animals↗
PubMed1995

[The determination of oral care habits by surveying the children of Russia and Finland].

Questionnaires were distributed among 1187 children aged 7, 9 and 12 living in Moscow, St. Petersburg, Helsinki and Kuopio and dental examinations of these children were carried out. Children together with their parents answered the questions concerning tooth cleaning, consumption of sweets, parents' education. Analysis of the results helped detect the population motivation to proper care of the oral cavity and time course of this motivation.

Child↗
PubMed1991

Subspecies-specific haemagglutination patterns of fimbriated Bacillus thuringiensis spores.

Electron microscopy revealed fimbrial appendages (pili) of three types on the surface of Bacillus thuringiensis spores. Fimbriated spores induced mannose-resistant agglutination of rat, guinea pig and/or chicken red blood cells. Each haemagglutination pattern correlated with the subspecies of a given B. thuringiensis strain, rather than with its flagellar serotype. Fimbriation and haemagglutination patterns of B. thuringiensis spores are considered to be of possible taxonomic value.

Animals↗
PubMed1991

Background factors of enamel focal demineralization in groups of Finnish and Russian children.

The aim of this study was to analyze the occurrence of EFD lesions in relation to some background factors in Finnish and Soviet children. Children aged 7, 9 and 12 years (n = 1187) were examined clinically in Helsinki, Kuopio (Finland), Moscow and Leningrad (USSR). A questionnaire sent to the parents was used to collect data on toothbrushing frequency, use of sweets, cakes, soft drinks, sugar-sweetened tea/coffee and mother's education. In addition to bivariate analysis, log-linear regression models were used for comparing the simultaneous association in two ethnic groups. In general, the Finnish children had more EFD lesions than the Soviet children did. Among the Finns no consistent associations were found between the number of EFD lesions and the use of different sugar products or differences in toothbrushing habits. The number of EFD lesions decreased consistently according to mother's education with the Finnish children, but not with the Soviet children. The final multivariate model for Finnish children included age, toothbrushing frequency, place of residence (Kuopio) and use of soft drinks. The respective model for the Soviet children included age and place of residence (Leningrad). Evidently, the demineralization process or tooth resistance differs in these two ethnic groups.

Carbonated Beverages↗
PubMed1991

[Genetic properties of the nonflagellar Bacillus thuringiensis mutant].

The nonflagellar mutant has been selected in Bacillus thuringiensis strain 33-69 var. galleriae. The absence of flagella in the mutant cells is confirmed by electron microscopy, by the specific "trench transit" test. The mutant preserved the biochemical characteristics of the parent strain, possesses the same phage sensitivity but lower sporulation ability. Fla+ phenotype is cotransduced with the His+ one in general transduction.

Bacillus thuringiensis↗
PubMed1991

Surface-specific effect of a mineralizing agent on the permanent teeth and on periodontal status.

In a two-year clinical trial the surface-specific effect of a mineralizing agent on selected permanent teeth was evaluated as well as the effect of this agent on periodontal health in children. Compared with positive controls (Control group, n = 123, biweekly mouthrinsing with placebo and 0.2% NaF solutions), among children in the test group (n = 123, biweekly mouthrinsing with 2% Remodent and 0.2% NaF solutions) the mineralizing agent clearly affected periodontal health (as determined by the prevalence of subjects with gingival bleeding and occurrence of affected sextants at risk) positively, in addition to having a positive effect on the incidence of EFD lesions. The mineralizing agent tested was not found to have adverse effects (as determined by the prevalence of subjects with dental calculus and occurrence of affected sextants at risk). Use of the mineralizing agent is recommended especially during posteruptive maturation of permanent teeth.

Cariostatic Agents↗
PubMed1990

Mineralizing agents in caries prevention: a review of the effects of Remodent.

Caries reduction from tooth brushing with Remodent occurs according to age, from 37.8% to 83.7% during a two to three year follow-up. The highest reduction was gained when the program was started at the age of 2. When Remodent-solution and -varnish were tested in one to three year follow-up, reductions in caries occurred from 20% to 91%. These studies also showed that the effect was best when the preventive treatment was started early.

Cariostatic Agents↗