[Comparative analysis of the stress-strain state of standard and individual reconstructive plates]. / Sravnitel'nyi analiz napryazhenno-deformirovannogo sostoyaniya standartnoi i individual'noi rekonstruktivnykh plastin.

OBJECTIVE: The aim of the study was to analyze a three-dimensional finite element model of a post-resection defect of the lower jaw, design and producing of an individual reconstructive plate, compare the stress-strain of this plate using standard reconstructive «CONMET¼ plate for stabilizing the lower jaw segments through a simulation of the chewing load. MATERIAL AND METHODS: The study was carried out on two identical finite elementary models with bone defects in the body of the lower jaw by fixing with a standard reconstructive «CONMET¼ plate and designed reconstructive plate. In order to simulate the biomechanical loads on the plates when chewing, an impact of force during the occlusal contact of the incisor was applied. The magnitude of the vertical load was equal to 150 N. The condylar processes were fixed in all three directions to prevent reaction forces in the temporomandibular joint. RESULTS: Comparative analysis of two fixation methods showed higher value of equivalent Von Mises stress in individual reconstructive plate than in standard plate. CONCLUSION: Individual reconstructive plate has better strength characteristics compared to the standard reconstructive «CONMET¼ plate.

[CLINICAL STUDY OF THE STATE OF RESIN-BONDED FIXED PARTIAL DENTURES IN INDIVIDUALS WITH HIGH TEETH ABRASION].

The object of the paper is a clinical assessment of the resin-bonded fixed partial dentures (RBFPD) produced by the indirect method of dental composite resin materials with various reinforcement, in patients with I degree high teeth abrasion. 80 persons with I degree high teeth abrasion and small defects in the lateral part of dental arch with a length of not more than one tooth were examined. For patients of I group, 40 RBFPDs were made of nano dental composite resin and three glass fiber tapes laid horizontally; for patients of II group, 40 RBFPDs made of hardened nano dental composite resin were reinforced with the same tapes laid by the developed method. In 12 months, fractures and fixation disorders of 9 dentures were found in patients from I group (22.5% of the initial quantity), and patients of II group had fixation disorders in 2 dentures (5.0%), and 7 (17.5%) and 32 dentures (80.0%), respectively, had no significant and insignificant disorders. In 24 months, the patients of I group had fractures and fixation disorders of another 7 dentures (22.6% of the number of RBFPDs at a given time), and patients from II group had such disorders in 3 RBFPDs (7.9%), while 3 dentures (7.5% of the initial amount) and 22 RBFPDs (55.0%), respectively, had no disorders. In order to restore the dental integrity with small bounded edentulous teeth in patients with I degree high teeth abrasion, it is possible to use RBFPDs indirect production of which requires the application of hardened nano dental composite resin with reinforcement by means of three glass fiber tapes according to the developed method, which ensures restoration efficiency within 12 and 24 months at the level of 80.0% and 55.0%.

Controllable skyrmion chirality in ferroelectrics.

Chirality, an intrinsic handedness, is one of the most intriguing fundamental phenomena in nature. Materials composed of chiral molecules find broad applications in areas ranging from nonlinear optics and spintronics to biology and pharmaceuticals. However, chirality is usually an invariable inherent property of a given material that cannot be easily changed at will. Here, we demonstrate that ferroelectric nanodots support skyrmions the chirality of which can be controlled and switched. We devise protocols for realizing control and efficient manipulations of the different types of skyrmions. Our findings open the route for controlled chirality with potential applications in ferroelectric-based information technologies.

[Microsatellite loci variation and investigation of gene flow between two karyoforms of Cricetulus barabensis sensu lato (Rodentia, Cricetidae)].

We examine the diversity of six microsatellite loci and partial RAG1 exon of "barabensis" and "pseudogriseus" karyoforms in Cricetulus barabensis sensu lato species complex. A total of 435 specimens from 68 localities ranging from Altai to the Far East are investigated. The results of the population structure analysis (factor analysis and NJ tree based on Nei genetic distances) support subdivision into two well-differentiated clusters corresponding to the two karyoforms. These karyoforms are also well differentiated by the level of microsatellite variability. In several "barabensis" specimens, we found microsatellite alleles that are common in "pseudogriseus" populations but are otherwise absent in "barabensis." Most of these specimens originate from a single population in one of the zones of potential contact between karyoforms, Kharkhorin in Central Mongolia. These molecular results are consistent with previously published karyological data in suggesting that rare hybridization events between the two chromosomal races occur in nature.

[Features of the B chromosome in Korean wood mice Apodemus peninsulae (Thomas, 1906) from Transbaikalia and the Far East identified by the FISH method].

Korean field mice (Apodemus peninsulae) are widely distributed throughout northeastern Asia, including the Russian Far East, northern China, the Korean peninsula, Sakhalin, and Hokkaido. This mouse species is characterized by a high frequency of animals with B chromosomes differing in their number, morphology, and DNA composition in different geographical regions. For the first time a comparative analysis of DNA probes from B chromosomes with metaphase chromosomes of mice from Transbaikalia, the Far East (including the Russian Far East), Japan, and South Korea was conducted by in situ hybridization. B chromosomes in mice from the Russian Far East were shown to exhibit low variability in DNA content; however, the DNA composition of B chromosomes in species from Transbaikalia and Japan were highly variable. B chromosomes in A. peninsulae from the South Korean population demonstrate minor differences from those from the Russian Far East. We discuss the origin of B chromosomes in the studied region in comparison with previously obtained data for mice from Siberia and the Baikal region, as well as the dispersal routes of the Korean field mouse.

[Diversity of the mitochondrial DNA cytochrome B gene of the field mouse Apodemus Agrarius Pallas, 1771 in the south of the Russian far east].

We studied the variability of a fragment of the cytochrome b gene and the corresponding amino acid sequence of the field mouse Apodemus agrarius (Pallas, 1771) in the South of Primorskii krai (Far East of Russia). A significant polymorphism of these traits was detected. High indices of molecular diversity were obtained. The topology of the phylogenetic tree and the median networks suggest that the population of field mice in the south of Primorskii krai originated from three maternal lines. It was noted that clustering of haplotypes on a territorial basis is absent, and the field mouse population in southern Primorskii krai can be considered as one of the key points in maintaining a high genetic diversity of the species.

[Genetic diversity and phylogenetic relationships of the Manchurian zokor Myospalax psilurus (Rodentia, Muridae) according to RAPD-PCR analysis].

The population structuring and low genetic diversity of the Manchurian zokor Myospalax psilurus Milne-Edwards, 1874, an East Asian endemic included in the Red List of Russia, were demonstrated. Two separate geographical groups differing in the level of their genetic diversity were found on the territory of the Primorskii krai. The subpopulation located closest to the main area of this species was determined as ancestral. A subspecies differentiation of the Primorskii krai and Transbaikal M. psilurus populations was shown, as was the monophyletic origin of M. psilurus and its high divergence from M. aspalax. The animals from northern localities are recommended for reintroduction in nature under species recovery programs in Primorskii krai.

[Genetic diversity and phylogenetic relationships in the zokor subfamily Myospalacinae (Rodentia, Muridae) inferred from RAPD-PCR].

Zokors (Myospalacinae) is a group of rodents specialized for underground life, endemics of eastern Asia, which is taxonomically and evolutionarily poorly studied. We examined genetic diversity and phylogenetic relationships among zokors (Myospalax myospalax, Myospalax aspalax, Myospalax armandii, Myospalax psilurus, Myospalax smithii) using RAPD-PCR. The subfamily Myospalacinae was shown to be monophyletic and contain four evolutionary branches: M. myospalax, M. aspalax-M. armandii, M. smithii and M. psilurus. Genetic differences and high differentiation were found among the species and between two geographic forms of Manjurian zokor M. psilurus from the marginal parts of the range, Transbaikalia and Primorye. The psiluris phylogroup was shown to be dichotomically divided into two clades according to the geographical distribution of animals from Transbaikalia and Primorye. The genetic differentiation between the geographic forms of M. psilurus corresponded to the differentiation between morphologically similar species M. aspalax and M. armandii. M. armandii is a sister taxon with regard to M. aspalax. This new evidence on the evolutionary relationships among zokors does not contradict the traditional views inferred from morphological, karyological, and allozyme data, on isolation of M. myospalax and the character of form development in this group. The species status of Myospalax psilurus Milne-Edwards, 1874, M. epsilanus Thomas, 1912, M. armandii Milne-Edwards, 1867, which had been suggested earlier on the basis of biochemical and karyological data, was confirmed.

[Association of the serum level of apolipoprotein E with coronary artery disease and carotid artery atherosclerosis in Kyrgyz men with dyslipidemia].

AIM: To study an association of the serum level of apolipoprotein E (apo-E) with risk factors for coronary heart disease (CHD), blood lipids and that with CHD and carotid artery (CA) atherosclerotic lesion in Kyrgyz men with dyslipidemia. SUBJECTS AND METHODS: One hundred and three Kyrgyz men, including 48 with CHD and 55 without this disease, were examined. A clinical examination was performed and blood lipid composition and serum glucose and apo-E levels were determined. The diagnosis of CHD was established in accordance with the conventional criteria. Whether atherosclerosis was present was determined by ultrasound duplex scanning. RESULTS: Low serum apo-E concentrations were associated with the presence of obesity, the higher blood levels of glucose and triglycerides. There was no correlation with other lipid metabolic parameters and the presence of CHD. A nonlinear relationship was noted between serum apo-E levels and CA atherosclerotic lesion, which was more frequently observed in patients with the apo-E level in the lower and upper quartiles. CONCLUSION: Low serum apo-E content is a poor factor and associated with obesity, hypertriglyceridemia, elevated serum glucose levels, and the development of CA atherosclerosis.

[Microfluorimetric analysis of dynamics of genomic changes of Chinese hamster fibroblasts CHL V-79 RJK with multidrug resistance].

Results of karyological analysis of cells CHL V-79 RJK selected for resistance to ethidium bromide (EB) causing multidrug resistance (MDR) (line Vebr-5) were compared with the data of microfluorimetric determination of DNA content in individual chromosomes of the karyotype. The analysis was performed at the 11th and 88th passages. Karyotyping of Vebr-5 has shown the presence of an additional genetic material (ADM) in the form of homogenously or differentially stained regions (HSRs and DSRs, respectively) in two chromosomes (Z1 and Z6, loci 1 p29-31 and 1q26, respectively). HSRs in Z6, in the region of localization of the wild type of gene mdr, had unstable length and structure characteristic of morphological markers of amplification of genes of the family mdr. During long cultivation of Vebr-5 in the presence of EB (88 passages), the instability of HSRs in Z6 increased. Results of microfluorimetric analysis of Vebr-5 at the 11th passage have shown an increase in the DNA content not only in chromosomes Z1 and Z6 marked by HSRs, but also in three chromosomes (Z5, Z12 and Z13) that have no visual morphological changes. The corresponding analysis at the 88th passage has also revealed non-random changes in the DNA content in four more chromosomes: an increase in Z14, while a decrease in chromosomes 8, Z7, and Z9. A decrease of the DNA content in chromosomes is considered to be a result of a partial loss of genetic material, while its increase is a result of its translocation and (or) amplification. Coefficient of variation of the DNA content changes for large chromosomes amounted to about 9%. while for small chromosomes it is about 26%, which indicates that small chromosomes have greater potential for instability than the large ones. The data obtained not only confirm, but also enlarge the concept of directions and character of destabilization of the cell genetic apparatus in the process of neoplastic transformation due to the MDR acquisition by cells.

A phase I trial of DNA vaccination with a plasmid expressing prostate-specific antigen in patients with hormone-refractory prostate cancer.

Prostate-specific antigen (PSA) is a serine protease secreted at low levels by normal luminal epithelial cells of the prostate and in significantly higher levels by prostate cancer cells. Therefore, PSA is a potential target for various immunotherapeutical approaches against prostate cancer. DNA vaccination has been investigated as immunotherapy for infectious diseases in patients and for specific treatment of cancer in certain animal models. In animal studies, we have demonstrated that vaccination with plasmid vector pVAX/PSA results in PSA-specific cellular response and protection against tumour challenge. The purpose of the trial was to evaluate the safety, feasibility and biological efficacy of pVAX/PSA vaccine in the clinic. A phase I trial of pVAX/PSA, together with cytokine granulocyte/macrophage-colony stimulating factor (GM-CSF) (Molgramostim) and IL-2 (Aldesleukin) as vaccine adjuvants, was carried out in patients with hormone-refractory prostate cancer. To evaluate the biologically active dose, the vaccine was administered during five cycles in doses of 100, 300 and 900 microg, with three patients in each cohort. Eight patients were evaluable. A PSA-specific cellular immune response, measured by IFN-gamma production against recombinant PSA protein, and a rise in anti-PSA IgG were detected in two of three patients after vaccination in the highest dose cohort. A decrease in the slope of PSA was observed in the two patients exhibiting IFN-gamma production to PSA. No adverse effects (WHO grade >2) were observed in any dose cohort. We demonstrate that DNA vaccination with a PSA-coding plasmid vector, given with GM-CSF and IL-2 to patients with prostate cancer, is safe and in doses of 900 microg the vaccine can induce cellular and humoral immune responses against PSA protein.

[Gene-geographical variation and genetic differentiation in red-backed voles of the genus Clethrionomys (Rodentia, Cricetidae) in the Okhotskii region]. / Genogeograficheskaia izmenchivost' i geneticheskaia differentsiatsiia lesnykh polevok roda Clethrionomys (Rodentia, Cricetidae) Priokhot'ia.

Thirteen enzyme systems and three nonenzyme proteins were electrophoretically analyzed in red-backed voles of the genus Clethrionomys. In total, 25 loci were interpreted. Gene-geographic variation was studied and indices of genetic variability and differentiation were determined. By the distribution of electrophoretic variants of hemoglobin, C. rutilus was shown to be divided into two geographical groups (northern and southern). A low level of genetic differentiation was revealed in the island isolates of C. rutilus and C. rufocanus. Separation of C. rufocanus, C. rex, and C. sicotanensis into a superspecies complex was confirmed. A study of differential G- and C-banding on C. rutilus and C. rufocanus chromosomes did not reveal intraspecific variation of autosomes. In these species, karyotypes of voles from Kamchatka Peninsula were studied for the first time. They appeared to be morphologically similar to the karyotypes continental voles by both autosomes and sex chromosomes.

Altered expression of DNA-topoisomerase IIalpha is associated with increased rate of spontaneous polyploidization in etoposide resistant K562 cells.

Molecular mechanisms of drug resistance and alterations in chromosome number were studied in two independently etoposide selected clonal cell lines, K562-VP16-1 and K562-W16-2, and in bulk cell line K562-VPI6. In all cell lines was observed down-regulation of topo IIalpha gene expression, while topo IIbeta mRNA content was unchanged compared to parental cell line. Antiapoptotic bcl-2 mRNA content was decreased in all drug resistant cell variants, the level of bcl-X(L) mRNA was greatly diminished only in one of cell lines, K562-VP16-1. Proapoptotic bax mRNA was down regulated to an undetectable level in all resistant cell lines analysed. These data indicate that abrogation of bax-mediated apoptosis can be implicated in development of etoposide resisance. Cytogenetic analysis revealed increased rate of spontaneous polyploidization in K562-VPI6 bulk and K562-VP-16-2 cells, while in K562-VP-16-1 cells was observed only moderate accumulation of polyploid cells. The degree of changes in topo IIa but not bcl-2 family members expression correlated positively with dynamics of accumulation of polyploid cells. Our findings suggest that down regulation of topo IIalpha in association with p53 deficiency can confer chromosomal instability in etoposide-resistant K562 cells.

[Chromosomal variability of the field mouse Apodemus agarius (Rodentia, Muridae)]. / Khromosomnaia izmenchivost' polevoi myshi Apodemus agarius (Rodentia, Muridae).

Chromosome sets of 114 Apodemus agrarius mice from 29 localities in Moldova, Ukraine, Siberia, and Far East were studied by means of G-, C-, and NOR-banding. In all populations studied, the Y chromosome was shown to be a medium-size acrocentric chromosome consisting of heterochromatin. Chromosome polymorphism observed in populations from Primorskii krai concerned (1) the morphology of the first two autosome pairs (variants A/A, A/ST, and ST/ST), (2) the number of metacentric chromosomes (from 6 to 8), and (3) heterochromatin localization in the pericentromeric regions of two metacentric chromosome pairs. A karyotype with an additional heterochromatic microchromosome found in all the metaphases studied was described in one mouse from a locality of western Primorye that has not been studied previously. In the karyotype of 15 mice from four populations of Primorye, the pool of nucleolus organizer regions is distributed over three autosome pairs rather than over four, as is the case A. agrarius from Europe. Based on the analysis of literature sources and our own data, the problem of chromosome polymorphism in the field mouse is discussed.

[Mechanisms of drug resistance of two cell lines of human chronic promyelocytic leukemia K562, resistant to DNA topoisomerase II inhibitors adriamycin and etoposide]. / Issledovanie mekhanizmov lekarstvennoi ustoichivosti dvukh kletochnykh linii khronicheskogo promieloleikoza cheloveka linii K562, rezistentnykh k ingibitoram DNK-topoizomerazy II adriamitsinu i etopozidu.

Mechanisms of drug-resistance in two K562 cell lines selected for adriamycin and etoposide resistance (K562-ADR and K562-VP16, respectively) were studied. In K562-ADR cells, overexpression of mdr 1 gene and two-fold reduction of topoisomerase II alpha mRNA content were found, while topoisomerase II beta expression remained unchanged, compared to the parental cell line. Antiapoptotic bcl-2 mRNA level was four-fold decreased in K562-ADR cells, while the expression of other members of bcl-2 family was unaffected. In K562-VP16 cells five-fold reduction of topoisomerase II alpha expression was found with the absence of mdr 1 gene overexpression. The expression of antiapoptotic bcl-2 and proapoptotic bax genes was reduced in K562-VP16 cell line, while the content of bcl-2 mRNA was increased. Cytogenetic analysis of K562-VP16 cells revealed morphological changes in their cell karyotype and susceptibility of these cells to spontaneous polyploidization. Possible effects of etoposite on mitotic control in K562-VP16 cells are discussed.

[Pleiotropic changes in karyotype structure of Chinese hamster fibroblast cell lint CHL V-79 RJK in relation to their acquisition of resistance to etoposide, an inducer of apoptosis]. / Pleiotropnye izmeneniia struktury kariotipa fibroblastov kitaiskogo khomiachka linii CHL V-79 RJK v sviazi s priobreteniem imi ustoichivosti k étopozidu-induktory apoptoza.

Chinese hamster fibroblasts CHL V-79 RJK were subjected to multistep selection in the presence of etoposide, known as an inhibitor of topoisomerase II and inductor of apoptosis. The karyotype of cells stably resistant to etoposide was analysed at progressive stages of selection using G-type staining of metaphase chromosomes. Multiple changes in the karyotype of resistant cells were observed at an early stage of selection (0.2 mg/ml of etoposide) and included: random chromosome breaks leading to formation of new chromosome markers, high frequency of aneuploid and polyploid cells, morphological instability and extracopy of q-shoulder of chromosome 1. On advanced stages of selection we observed an increased frequency of specific minute chromosome and the appearance of chromosomes with homogeneously or differentially stained regions (HSR and DSR). These data suggest that different mechanisms may be involved in developing cellular resistance to etoposide at progressive stages of selection.

Resistance to adriamycin in human chronic promyeloleukemia line K562 correlates with directed genome destabilization--amplification of MDR1 gene and nonrandom changes in karyotype structure. / Ustoichivost' kletok khronicheskogo promieloleikoza cheloveka linii K562 k adriamitsinu korreliruet s napravlennoi destabilizatsiei genoma--amplifikatsiei gena MDR1 i ne sluchainymi izmeneniiami v strukture genotipa.

Three independent subclones (B2, B3 and C9) of human myelogenous leukemia cell line K562 selected with adriamycin (ADM) were analysed. Cross-resistance of these ADM-resistant cells was examined for a resistance to the number of drugs including colchicine, actinomycin D and ethidium bromide. MDR 1 gene amplification in B3 and C9 subclones was detected using Southern-hybridization with specific probe. Additional genetical material was found in genomes of resistant cells by analysis of G-banded metaphase chromosomes. An extraordinarily long marker chromosome was observed in every C9 metaphase plate. The character of this chromosome G-banding suggests that it may be a derivative of chromosome 5 containing a large homogeneously staining region (HSR) in locus 5q15. Both B2 and B3 subclones expressed double minute chromosomes (DMs) in 5% of cells. In the course of a prolonged cultivation (about 2 years) of C9 cells in the presence of ADM a progressive karyotype destabilization was observed: the frequency of new markers formation in C9 cells increased, cells having additional copies of marker chromosome with HSR appeared, the length of HSR varied, coexistence of HSR and DMs being found in several C9 cells. These karyotypical changes may be regarded as patterns of genome destabilization due to the multidrug resistance of K562/ADM cells.

[Chromosome variation and anomalous karyotypes in the red-backed mouse Clethrionomys rufocanus (Rodentia, Microtinae)]. / Khromosomnaia izmenchivost' i anomal'nye kariotipy u krasno-seroi polevki Clthrionomys rufocanus (Rodentia, Microtinae).

G-banding and C-banding of chromosomes were studied in populations of the red-backed mouse Clethrionomys rufocanus from 11 localities of eastern Russia. Intrapopulation polymorphism of autosome 3 caused by the deletion-duplication of the short-arm heterochromatin (2n = 56; NFa = 56-58) was demonstrated. The karyotype of Cl. rufocanus from continental populations and Sakhalin Island was shown to have a large subtelocentric chromosome of pair 3 (NFa = 58), whereas in the population from Kunashir Island, chromosomes of this pair were acrocentric (NFa = 56). One animal from the population of the Kedrovaya Pad' Reserve (Primorsk krai) had a pericentric inversion (acrocentric morphology) of the Y chromosome. In two animals, a female from the Ussuriiskii Reserve (Primorsk krai) and a male captured near the Tomari Settlement (Sakhalin Island), a pericentric inversion of one chromosome of pair 6 was found (NFa = 59). The inversion detected in the animal from the Sakhalin population was accompanied by the loss of the centromeric heterochromatin. In contrast, the inversion of the chromosome pair 6, which was found in the mouse from the Primorsk krai population, did not involve the loss of centromeric heterochromatin. Analysis of our results and data from the literature showed that the karyotype of Cl. rufocanus is not constant, as was thought earlier. The percentage of animals with abnormal karyotype (1.6%) was higher than in other groups of red-backed mice studied (0.12-0.7%).

[Genetic differentiation of Caucasian wood mice: comparison of isozymic, chromosomal and molecular divergence]. / Geneticheskaia differentsiatsiia lesnykh myshei Kavkaza: sravnenie izozimnoi, khromosomnoi i molekuliarnoi divergentsii.

Data on the complex genetic analysis of three sympatric species of Caucasian wood mice, Apodemus ponticus, A. fulvipectus, and A. uralensis are presented. A high degree of genetic differentiation at the isozymic, karyological and molecular (nuclear DNA) levels was revealed. The genetic distances between each pair of species varied significantly within a wide range depending on the analyzed level of the organization of genetic material. Mean values of genetic divergence from one species to another were also variable. These findings indicated that evolution of chromosomes was slower than that of isozymes, and the degree of species divergence was similar on cytogenetic and molecular levels. They also suggested that the rates of species evolution could vary in different phyletic lineages and on different levels of organization. Some phyletic lineages of Apodemus could be distinguished by different directions of evolution.