[Assessment of the safety and accuracy of implantation of screws into the C2 vertebra using individual 3D-navigation matrices]. / Otsenka bezopasnosti i tochnosti implantatsii vintov v S2 pozvonok s primeneniem individual'nykh 3D-navigatsionnykh matrits.

INTRODUCTION: Individual 3D-navigation matrices are valuable to increase the safety of screw implantation into the axis. OBJECTIVE: To analyze safety and accuracy of screw deployment into the axis using individual 3D-navigation matrices compared to free hand technique. MATERIAL AND METHODS: A retrospective analysis included 23 patients (group 1) who underwent implantation of 44 screws into the axis using the «free hand¼ technique. The screws were installed along the transpedicular or pars trajectory. A prospective analysis enrolled 17 patients (group 2) who underwent installation of 34 screws using individual navigation matrices. 3D-printing technology was applied for manufacturing these matrices. Implantation results were evaluated considering postoperative CT data and SGT (Screw Guide Template) system. RESULTS: In the 1st group («free hand¼), grade 0 and 1 (no malposition or less than 50% of screw diameter) were recorded for 29 (65.91%) screws, grade 2 - for 13 (29.55%) screws, grade 3 - for 2 (4.45%) screws. Intraoperative injury of the vertebral artery without postoperative neurological deficit occurred in 4 (8.89%) patients. In the 2nd group, 97% of screws were implanted in accordance with grades 1 and 2. Deviation grade 2 was registered in 11 cases (32.35%). Mean deviation was 1.8 ± 1.0 mm. In the 2nd group, 28 (82.35%) out of 34 screws were completely within the bone structures (grade 0), 4 (11.76%) screws perforated pedicles for less than 50% of their diameter (grade 1). There were 2 cases of malposition grade 2 and 3 without vertebral artery injury. CONCLUSION: Individual 3D navigation matrix is an effective method for screw installation into the axis. This approach exceeds fluoroscopy-assisted "free hand" technique in terms of safety of implantation.

[Genetic risk factors for sporadic germ cell testicular tumors].

INTRODUCTION: Approximately 95% of all testicular cancers are testicular germ cell tumors (GCTTs), represented by seminoma and nonseminoma germ cell testicular cancer. There is a hypothesis that the formation of GCTTs begins in early embryogenesis being a part of testicular dysgenesis syndrome (TDS). AIM: To determine the role of genetic factors in the development of GCTTs. MATERIALS AND METHODS: We studied the frequency of alleles and genotypes KITLG (rs995030, rs1508595), SPRY4 (rs4624820, rs6897876) and BAK1 (rs210138) in 97 fertile men (control), and 73 patients with GCTTs (34 seminoma and 39 nonseminoma). RESULTS: GCTTs were statistically significantly associated with KITLG rs1508595 gene (p=0.0003 for allele G, p=0.0014 for genotype GG), and with rs995030 gene (p=0.0031 for genotype GG). When comparing patients with seminoma and control group, statistically significant differences were found for SPRY4 rs4624820 (p=0.0226 for the A and p=0.04 for the AA), for KITLG rs995030 (p=0.0375 for the G and p=0.0282 for GG), rs1508595 (p=0.0306 for G), for BAK1 rs210138 (p=0.0329 for the G and p=0.0219 for the GG). When comparing patients with nonseminoma and fertile men, statistically significant differences were found only for KITLG rs1508595 (p=0.0005 for the G and p=0.0021 for the GG). There was no statistically significant difference between the allele and genotype frequencies of the investigated genes from seminoma and nonseminoma GCTTs patients. However, these groups differed statistically significantly when genotype combinations of the three genes were investigated (p=0,029; OR 3,709 [1.147-11.99]). The combination of genotypes of the three genes was found to increase the risk of GCTTs by 6.5 times (p=0.0005; OR 6.526 [2.078-20.5], and the risk for seminoma was over 12-fold (p<0.0001; OR 12,68 [3,731-43,11]. CONCLUSION: A comprehensive study of genotypes associated with GCTTs in patients with manifested TDS can be used for risk stratification to identify and follow-up high-risk patients, develop approaches to family counseling and treatment, which is the basis for predictive medicine.

[Polymorphisms of KITLG, SPRY4, and BAK1 genes in patients with testicular germ cell tumors and individuals with infertility associated with AZFc deletion of the Y chromosome].

Testicular cancer is the most common form of solid cancer in young men. Testicular cancer is represented by testicular germ cell tumors (TGCTs) derived from embryonic stem cells with different degrees of differentiation in about 95% of cases. The development of these tumors is related to the formation of a pool of male germ cells and gametogenesis. Clinical factors that are predisposed to the development of germ-cell tumors include cryptorchidism and testicular microlithiasis, as well as infertility associated with the gr/gr deletion within the AZFс locus. KITLG, SPRY4, and BAK1 genes affect the development of the testes and gametogenesis; mutations and polymorphisms of these genes lead to a significant increase in the risk of the TGCT development. To determine the relationship between gene polymorphisms and the development of TGCTs, we developed a system for detection and studied the allele and genotype frequencies of the KITLG (rs995030, rs1508595), SPRY4 (rs4624820, rs6897876), and BAK1 (rs210138) genes in fertile men, patients with TGCTs, and patients with infertility that have the AZFс deletion. A significant association of rs995030 of the KITLG gene with the development of TGCTs (p = 0.029 for the allele G, p = 0.0124 for the genotype GG) was revealed. Significant differences in the frequencies of the studied polymorphisms in patients with the AZFc deletion and the control group of fertile men were not found. We showed significant differences in the frequencies for the combination of all high-risk polymorphisms in the control group, patients with the AZFc deletion and patients with TGCTs (p (TGCTs-AZF-control) = 0.0207). A fivefold increase in the frequency of the combination of all genotypes in the TGCT group (p = 0.0116; OR = 5.25 [1.44-19.15]) and 3.7-fold increase was identified in patients with the AZFc deletion (p = 0.045; OR = 3.69 [1.11-12.29]) were revealed. The genotyping of patients with infertility caused by the AZFc deletion can be used to identify individuals with an increased risk of TGCTs.

[The molecular genetic alterations in mucosa of intestines as markers of oncologic progression and estimate of effectiveness of anti-reflux operations in patients with Barrett's esophagus].

The development of disease of Barrett's esophagus is based on processes of metaplasia of epithelium of esophagus when as a result of reflux of gastric juice and bile acids the normal planocellular epithelium of esophagus is replaced by cylindrical epithelium of intestinal type. Thereupon, Barrett's esophagus is progressing up to dysplasia and adenocarcinoma of esophagus. The progression from precancerous states up to tumor is related to development of genome disorders in cells associated with malignant transformation. The genetic and epigenetic alterations conditioning tumor growth can be used as markers of prognosis of clinical course of disease. To receive possible markers of progression of Barrett's esophagus the study was organized concerning methylation of such genes-suppressors of tumor growth as MGMT, CDH1, p16/CDKN2A, DAPK, RAR-ß and RUNX3 in patients with Barrett's esophagus and adenocarcinoma of esophagus. The effectiveness of applied anti-reflux surgical treatment was evaluated too. The abnormal methylation of studied genetic panel in patients with Barrett's esophagus prior to surgical treatment was observed reliably more frequently in altered epithelium as compared with unaltered epithelium (p<0.0001), under dysplasia as compared with metaplasia (p<0.0358) and in the presence of long (>3 cm) segments of altered epithelium as compared with short (<3 cm) segments (p=0.0068). In normal epithelium, prior to operation, abnormal methylation of panel of genes was detected in 7/60 (12%) of patients. Against the background of surgical treatment number of long and short segments of altered epithelium of esophagus reliably decreased (p<0.05). At that, in short segments after operation rate of methylation increased significantly (p=0.0068). Though after operation number of patients with Barrett's esophagus and dysplasia and metaplasia decreased, the rate of abnormal methylation in the other patients increased. It is demonstrated that anti-reflux operation ameliorates condition of mucous membrane of esophagus under Barrett's esophagus. However, in cases without regression significant increasing of rate of abnormal methylation of studied panel of genes is occurred. This is a proof that abnormal methylation of system of genes is related to worse response to application of anti-reflux surgical treatment.

[Reduced representation bisulfite sequencing design for assessing the methylation of human CpG islands in large samples].

The reduced representation bisulfite sequencing (RRBS) method has been developed for the high-throughput analysis of DNA methylation based on the sequencing of genomic libraries treated with sodium bisulfite by next-generation approaches. In contrast to whole-genome sequencing, the RRBS approach elaborates specific endonucleases to prepare libraries in order to produce pools of CpG-rich DNA fragments. The original RRBS technology based on the use of the MspI libraries allows one to increase the relative number of CpG islands in the pools of genomic fragments compared to whole-genome bisulfite sequencing. Nevertheless, this technology is rarely used due to the high cost compared with bisulfite methylation analysis with hybridization microarrays and significant residual amount of data represented by the sequences of genomic repeats that complicates the alignment and is not of particular interest for developing DNA methylation markers, which is often the main goal of biomedical research. We have developed an algorithm for estimating the likelihood that recognition sites of restriction endonucleases will be represented in CpG islands and present a method of reducing the effective size of the RRBS library without a significant loss of the CpG islands based on the use of the XmaI endonuclease for library preparation. In silico analysis demonstrates that the optimum range of the XmaI-RRBS fragment lengths is 110-200 base pairs. The sequencing of this library allows one to assess the methylation status of over 125000 CpG dinucleotides, of which over 90000 belong to CpG islands.

[DNA methylation in the promoter regions of the laminin family genes in normal and breast carcinoma tissues].

Extracellular glycoproteins of the laminin family are essential components of basement membranes involved in a number of biological processes, including tissue differentiation, wound healing, and tumorigenesis. We present the first comprehensive study of promoter methylation status of the genes encoding laminin chains in normal tissues (peripheral blood leucocytes, buccal epithelial cells, autopsy breast tissue samples) and in breast carcinoma samples. Based on the results of this study, we divide laminin genes into three categories. Genes, constitutively methylated in breast tissues include LAMA3A, LAMB2, LAMB3, and LAMC2. Genes prone to abnormal methylation in breast carcinoma include LAMA1, LAMA2, LAMA3B, LAMA4, LAMB1, and LAMC3. Genes that are rarely if ever methylated in breast carcinoma include LAMA5 and LAMC1. The constitutively methylated group includes all of the genes that encode subunits of laminin-5 (the historical name of laminin 332), the promoters of which were previously considered unmethylated in normal tissues and prone to abnormal methylation in breast cancer.

[Sensorineural hearing impairment in combination with mycoplasma infection].

The objective of the present study was to elucidate the incidence of mycoplasma infection concomitant with sensorineural hearing impairment and its clinical manifestations with special reference to the methods for its diagnostics and treatment. The main method for the detection of mycoplasma infection is PCR in real time and the auxiliary one is the immunoenzymatic assay. The study revealed mycoplasma infection in 15 (13.9%) of the examined patients. The results of our investigations give evidence of the necessity to further study the clinical symptoms of mycoplasma infection associated with sensorineural hearing impairment and to search for the methods of the management of this condition.

[Structural and functional analysis of tumor genomes and the development of test systems for early diagnosis, prognosis and cancer therapy optimization].

The article discusses results of the structural and functional analysis of molecular genetic abnormalities in various malignant tumors. Investigations have discovered more than 20 new markers for sporadic breast cancer. Several of them formed the test system, allowing the diagnosis with a specificity of 100%. Appearance of TMPRSS2/ERG4 chimeric gene is a frequent tumor-specific event, its expression is correlated with more aggressive forms of prostate cancer, may serve as a molecular marker for tumor cells and androgen assessment of tumor response to hormonal therapy. The effective systems for the early diagnosis of cervix and endometrium cancer were developed as well. Mutations in the VHL, deletions of chromosome 3 and methylation of several genes can predict the course and selection of effective therapy of clear cell kidney cancer, a number of molecular markers were identified for early diagnosis and prognosis of recurrence of bladder cancer. For diagnosis, prognosis and treatment of brain tumors we developed an effective complex system of markers. Protocol of molecular genetics investigation reveals the cause of the disease by more than 90% of patients with retinoblastoma. In order to study abnormal methylation in tumor genomes an innovative technology AFLOAT has been developed that allows to efficiently identify new markers with diagnostic value. Test systems of molecular genetic and epigenetic markers for early diagnosis and prognosis as well as for cancer therapy optimization have shown to be effective, have been approved for use in clinical practice and are being introduced into practical healthcare.

[Chlamygial and mycoplasmal infections in otorhinolaryngology (a systematic review)].

The objective of the present study was to analyse clinical manifestations of chlamydial and mycoplasmal infections of ENT organs as well as the methods of their diagnostics and therapeutic modalities used for their management. The authors illustrate, based on the results published in the domestic and foreign literature, the currently available diagnostic and therapeutic methods for the treatment of the above pathological conditions in otorhinolaryngology. A rationale for the further investigations of the clinical symptoms of chlamydial and mycoplasmal infections encountered in otorhinolaryngological practice has been developed.

[Age-related peculiarities of glutathione content changes in the brain of rats during immobilization stress].

The work is aimed at studying age-related peculiarities as regards glutathione content changes in the brain of rats under immobilization stress. It has been established that some changes in the content of reduced glutathione take place in the brain in the process of ontogenesis. During immobilization stress the content of this metabolite decreases in the brain of all age groups of rats under study. To a greater extent this shift manifests itself in 2- and 24-month-old rats which are characterized by more active stress-stimulated free-radical processes in the brain and by an initially higher level of reduced glutathione.