138 research outputs found
A novel concept for the manufacture of individual sapphire-metallic hip joint endoprostheses.
At the present time, artificial joints made with metallic, ceramic, metal-polymeric or ceramicpolymeric
friction pairs substituting for the natural biomechanic articulations "head of the hip
joint-acetabulum" are widely used for endoprosthetic operations on hip joints. Experience
gained in the course of more than 2000 operations has shown that along with the
advantageous properties of modern endoprosthetic constructions made of metal, ceramics
and polymers, they have certain drawbacks. Among them are insufficient biological inertness
and susceptibility to excessive wear of the friction pair components. In addition, as a result of
wear of the hinge friction pair, toxic and oncologically dangerous products of degradation
accumulate in the different organs and tissues. This in turn results in severe complications and
demands correspondingly complicated corrective intervention, often leading to worse
disability than that which the original operation was designed to cure. The aim of the study
reported here was the development and clinical validation of a highly effective and long-lived
hip joint endoprosthesis with a sapphire head whose wear capacity is superior to all others.
The endoprosthesis consists of a metallic pedicle, a dismountable articulation (metallic necklayer
of supramolecular polyethylene-sapphire head) and an acetabular cup. The endoprostheses
with the sapphire head proved themselves positively in clinical trials and are
considered to be highly promising for future applications
Polymorphisms in DNA repair genes and breast cancer risk in Russian population: a case–control study
© 2014, Springer-Verlag Italia. Genetic variation in DNA repair genes can alter an individual’s capacity to repair damaged DNA and influence the risk of cancer. We tested seven polymorphisms in DNA repair genes XRCC1, ERCC2, XRCC3, XRCC2, EXOI and TP53 for a possible association with breast cancer risk in a sample of 672 case and 672 control Russian women. An association was observed for allele A of the polymorphism XRCC1 (R399Q) rs25487 (co-dominant model AA vs. GG: OR 1.76, P = 0.003; additive model OR 1.28, P = 0.005; dominant model: OR 1.29, P = 0.03; recessive model OR 1.63, P = 0.008). Allele T of the polymorphism ERCC2 (D312N) rs1799793 was also associated with breast cancer risk (co-dominant model TT vs. CC: OR 1.43, P = 0.04; additive model OR 1.21, P = 0.02; dominant model: OR 1.30, P = 0.02), but the association became insignificant after applying Bonferroni correction. No association with breast cancer was found for the remaining SNPs. In summary, our study provides evidence that polymorphisms in DNA repair genes may play a role in susceptibility to breast cancer in the population of ethnical Russians
Association of Single Nucleotide Polymorphisms in the IL-18 Gene with Production of IL-18 Protein by Mononuclear Cells from Healthy Donors
IL-18 has proinflammatory effects and participates in both innate and adaptive cellular and humoral immunity. A number of SNPs that influence IL-18 production are found in the gene promoter region. We investigated the association of SNPs in the IL-18 promoter at −607 and −137 with the level of IL-18 protein production by PBMC from healthy donors from Southwestern Siberia. The genetic distribution of these SNPs in the promoter site was established by PCR. IL-18 protein production was determined by ELISA. Our results showed that PBMC from donors carrying allele 137C have lower levels of both spontaneous and LPS-stimulated IL-18 production. In contrast, PBMC from donors carrying allele 607A showed significant increases in spontaneous and stimulated IL-18 production compared to wild type. Our study suggests that the SNPs −607 and −137 in the promoter region of the IL-18 gene influence the level of IL-18 protein production by PBMC from healthy donors in Southwestern Siberia
TERT polymorphisms rs2853669 and rs7726159 influence on prostate cancer risk in Russian population
© 2014, International Society of Oncology and BioMarkers (ISOBM). Telomere length and telomerase activity have been hypothesized to play a role in cancer development. The aim of our study was to investigate the association of allelic variants of three functional polymorphisms rs2853669, rs2736100, and rs7726159 in the telomerase reverse transcriptase (TERT) gene with the risk of the breast cancer and prostate cancer in Russian population. Six hundred sixty women with breast cancer, 372 men with prostate cancer, and corresponding control groups of 523 women and 363 men were included in the present case–control study. We observed an association of allele rs2853669 C with increased risk of prostate cancer (co-dominant model TC vs. TT OR = 1.65, P = 0.002; additive model OR = 1.42, P = 0.005; dominant model: OR = 1.64, P = 0.001) and allele rs7726159 A with reduced risk of this malignancy (сo-dominant model: AA vs. CC OR = 0.42, P = 0.002; additive model: OR = 0.69, P = 0.002; dominant model: OR = 0.67, P = 0.01; recessive model: OR = 0.48, P = 0.005). None of the studied polymorphisms showed an association with the risk of breast cancer. Our results provide evidence that the TERT gene variability modulate prostate cancer predisposition in ethnical Russians
TCF7L2 gene polymorphism in populations of f ive Siberian ethnic groups
Investigation of the frequencies of functionally signif icant gene variants in the context of medical biology and gene geography is a relevant issue for studying the genetic structure of human populations. The transition from a traditional to an urbanized lifestyle leads to a higher incidence of civilizational diseases associated with metabolic disorders, including type 2 diabetes mellitus. The goal of the present paper is to analyze the frequencies of functionally signif icant gene alleles in the metabolic prof iles of indigenous Siberian peoples to identify the gene pool resilience, evaluate the susceptibility of various ethnic groups to metabolic disorders under changing environmental conditions, and predict the epidemiological situation that may occur in the near future. The study was performed in the monoethnic samples of eastern and western Buryats, Teleuts, Dolgans, and two territorial groups of Yakuts. A real-time PCR was used to determine the frequencies of single nucleotide polymorphisms (SNPs) G103894T, rs12255372, and C53341T, rs7903146 in the TCF7L2 gene. The results obtained were compared to the frequencies identif ied for Russians from Eastern Siberia and the values available in the literature. The frequencies of the polymorphic variants studied in the samples from the indigenous Siberian peoples place them in between Caucasian and East Asian populations, following the geographic gradient of polymorphism distribution. A signif icantly lower occurrence of type 2 diabetes risk alleles TCF7L2 (103894T) and TCF7L2 (53341T) in the samples of indigenous Siberian peoples compared to Russians was observed, which agrees with their lower susceptibility to metabolic disorders compared to the newcomer Caucasian population. Taking into account urbanization, a reduced growth in type 2 diabetes incidence may be predicted in indigenous Siberian peoples, i. e. Buryats, Yakuts, Dolgans, and Teleuts, compared to the newcomer Caucasian population. A further study of population structure with respect to different metabolic prof ile genes is required to better understand the molecular genetic foundations of the adaptive potential of indigenous Siberian peoples
Genotoxic agents promote the nuclear accumulation of annexin A2: role of annexin A2 in mitigating DNA damage
Annexin A2 is an abundant cellular protein that is mainly localized in the cytoplasm and plasma membrane, however a small population has been found in the nucleus, suggesting a nuclear function for the protein. Annexin A2 possesses a nuclear export sequence (NES) and inhibition of the NES is sufficient to cause nuclear accumulation. Here we show that annexin A2 accumulates in the nucleus in response to genotoxic agents including gamma-radiation, UV radiation, etoposide and chromium VI and that this event is mediated by the nuclear export sequence of annexin A2. Nuclear accumulation of annexin A2 is blocked by the antioxidant agent N-acetyl cysteine (NAC) and stimulated by hydrogen peroxide (H2O2), suggesting that this is a reactive oxygen species dependent event. In response to genotoxic agents, cells depleted of annexin A2 show enhanced phospho-histone H2AX and p53 levels, increased numbers of p53-binding protein 1 nuclear foci and increased levels of nuclear 8-oxo-2'-deoxyguanine, suggesting that annexin A2 plays a role in protecting DNA from damage. This is the first report showing the nuclear translocation of annexin A2 in response to genotoxic agents and its role in mitigating DNA damage.Natural Sciences and Engineering Research Council of Canada (NSERC); European Union [PCOFUND-GA-2009-246542]; Foundation for Science and Technology of Portugal; Beatrice Hunter Cancer Research Institute; Terry Fox Foundationinfo:eu-repo/semantics/publishedVersio
Genetic polymorphism of CYP1A1 and CYP2D6 in populations of Buryats, Teleuts and Russians of Eastern Siberia
The study of the gene polymorphism of the system of biotransformation of xenobiotics is an important area of modern medical and genetic research. The aim of this work is to study the frequency of the alleles of the CYP1A1 (A2455G (*2C), rs1048943), CYP2D6 (A2549del (*3), rs35742686); G1846A (*4), rs3892097) genes of Teleuts (n = 115), Eastern Buryats (n = 132), Western Buryats (n = 280), their Métis (n = 56), and Russians of East Siberia (n = 122). Genotyping was performed using real-time PCR with competitive TaqMan allele-specific probes. The frequency of the CYP1A1*2C (2455G) allele was 28.8 % in the Eastern Buryat, 34.6 % in the Western Buryat, 16.7 % in the Teleut, and 31.3 % in the Métis cohort. The frequency of CYP1A1*2C (2455G) in the Russians of Eastern Siberia (4.1 %) corresponds to the frequency range found in European populations. A high-frequency occurrence of CYP1A1*2C (2455G) among Buryats and Teleuts may be indicative of a higher population-wide risk of diseases influenced by technogenic pollutants – substrates of CYP1A1. The CYP2D6*3 (2549del) allele was not detected in cohorts of indigenous populations, among Russians it was 0.4 %, and it was 2.7 % among Métis. The frequency of CYP2D6*4 (1846A) in Eastern and Western Buryats was 5.3 % and 4.3 %, respectively, for Teleuts it was 7.4 %. It was significantly higher in the Russian population (12 %), and among Métis (9.8 %). The obtained data makes it possible to predict a reduced risk of side effects of drugs and cancer associated with CYP2D6*3 (2549del) and CYP2D6*4 (1846A) in the Buryat and Teleut populations. However, metisation introduces new polymorphic variants into indigenous populations, shifts gene frequencies and changes the degree of risks
Massive parallel sequencing for diagnostic genetic testing of BRCA genes - A single center experience
The aim of this study was to implement massive parallel sequencing (MPS) technology in clinical genetics testing. We developed and tested an amplicon-based method for resequencing the BRCA1 and BRCA2 genes on an Illumina MiSeq to identify disease-causing mutations in patients with hereditary breast or ovarian cancer (HBOC). The coding regions of BRCA1 and BRCA2 were resequenced in 96 HBOC patient DNA samples obtained from different sample types: peripheral blood leukocytes, whole blood drops dried on paper, and buccal wash epithelia. A total of 16 random DNA samples were characterized using standard Sanger sequencing and applied to optimize the variant calling process and evaluate the accuracy of the MPS-method. The best bioinformatics workflow included the filtration of variants using GATK with the following cut-offs: variant frequency > 14%, coverage ( > 25×) and presence in both the forward and reverse reads. The MPS method had 100% sensitivity and 94.4% specificity. Similar accuracy levels were achieved for DNA obtained from the different sample types. The workflow presented herein requires low amounts of DNA samples (170 ng) and is cost-effective due to the elimination of DNA and PCR product normalization steps
The ILE462VAL polymorphism of the cytochrome P450 CYP1A1 gene among Tundra Nenets in Yamalo-Nenets Autonomous Okrug, Nganasans in the Taimyr Peninsula and Russians in Siberia
The work concerns a polymorphism of the cytochrome Р450 CYP1A1 gene, the CYP1A1*2C variant (Ile462Val, rs1048943). This substitution results in a two- fold increase in enzyme activity, which leads to accumulation of active intermediates and increases the risk of DNA mutations and chemically induced carcinogenesis. It has been demonstrated that the 462Val allele may be a risk factor in some oncological and other multifactorial diseases. This study was performed on Tundra Nenets in Yamalo-Nenets Autonomous Okrug (N = 271), Nganasans in the Taimyr Peninsula (N = 186) and Russians in North Siberia (N = 267). The cohorts did not include descendants of mixed marriages. Genotyping was performed using Real-Time PCR with competitive TaqMan allele-specific probes. The frequency of the 462Val allele in the Tundra Nenets cohort was 23.8 % (95 % CI 20.4–27.6 %), which corresponds to the frequency range found in East Asian populations and is higher than the values typical of European populations. The 462Val allele frequency in the Russian cohort was 5.8 % (95 % CI 4.1–8.1 %), which corresponds to the frequency range of European populations. The 462Val allele frequency in the Nganasans cohort was 39.0 % (95 % CI 34.2–44.0 %), which is higher than the frequencies found in European, Asian and African populations. Frequencies of the 462Val variant close to that in Nganasans have been observed in Greenland Inuits, native Americans as a whole and the Southern Chinese. A high-frequency occurrence of the 462Val allele among Tundra Nenets and Nganasans may be indicative of a populationwide risk of diseases influenced by this genetic polymorphism, especially when traditional mainstays are gone or previously unknown ecotoxicants appear in the areas
Study of relationships between HLA-G gene polymorphism, intrauterine infection and recurrent miscarriage in women
The relationship between the HLA-G gene polymorphism (rs41551813, rs12722477, rs41557518), intrauterine infection and recurrent miscarriage (RM) in women were studied. The case group consisted of 180 patients with RM, defined as two or more consecutive miscarriages (min = 2; max = 8) at up to 20 weeks of gestation, and with clinically confirmed pregnancies and non-viable fetuses. At the time of examination. the women were enrolled from the Genetic Counseling Center at the Kemerovo Regional Clinical Hospital, Kemerovo, Russia, and were not pregnant. Each patient underwent a gynecological examination. We excluded women with a history of medical abortion, birth, and ectopic pregnancies. In addition, we excluded women with endocrine (e.g. diabetes) disorders. To exclude other known causes of spontaneous abortion, the following tests were performed: ultrasound examination of pelvic organs, and karyotyping in women and men. The women’s mean age in the RM group, was 29.6±4.8 (SD) years. The control group comprised 408 fertile women. These women didn’t have a history of spontaneous abortion, or a family history of congenital malformations. They have born, at least, 1-2 healthy children. Women’s mean age at birth of last child was 26.8±5.2 (SD) years. Influence of the intrauterine infection was analyzed on the basis of laboratory tests. Diagnostics of bacterial vaginosis and vulvo-vaginal candidiasis by microscopic examination was conducted. Viral agent infections (herpes simplex virus type 2, cytomegalovirus, human papilloma virus type 16/18), Chlamydia trachomatis, Mycoplasma hominis, Ureaplasma urealyticum, Gardnerella vaginalis and Trichomonas vaginalis were detected by enzyme-linked immunoassay and polymerase chain reaction (PCR). The data were obtained from the medical cards of the surveyed women. All the women gave a written informed consent before participating in the study. Typing of polymorphisms of Thr31Ser (rs41551813, HLA-G*01:03) in exon 2, Leu110Ile (rs12722477, HLA-G*01:04) and 1597 delС (rs41557518, HLA-G*01:05N) in exon 3 HLA-G genes were performed by realtime PCR followed by melting analysis. The study showed that the intrauterine infection was not a risk factor for RM (p = 0.30) in the examined women. It was found that the 110 Ile allele (HLA-G *01:04) was a risk factor for RM both in women with intrauterine infection [ORa = 4.50 (2.41-8.38), p = 2.09e-06], and in women without infection [ORa = 2.46 (1.44-4.21), p = 0.0009]. The cooperative influence of genetic and infections factors with the risk of RM in women was revealed [ORa+f = 3.50 (2.01-6.09), p = 8.78e-06]. Our results will be useful in understanding the molecular mechanisms of immune disorders in fetomaternal interface, and for choosing the strategy of management and treatment in women with RM
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