Sovremennye Tehnologii v Medicine最新文献

The aim of the study was to assess the capabilities of mRNA genes encoding CD16a (FCGR3A) and CD16b (FCGR3B) in tumor samples from patients with renal cancer, and characterize the tumor process in relation to clinical and morphological factors.

Materials and methods: We used 125 tumor samples from patients with a histologically confirmed diagnosis of renal cancer T_1-4N_0-1M_0-1. A method described by Chomczynski and Sacchi was used to isolate nucleic acids. The mRNA levels were determined using a reverse transcription polymerase chain reaction and calculated according to ΔΔCt formula, taking into account the reaction efficiency.

Results: mRNA of the FCGR3A gene was detected in all tumor tissue samples under study; in contrast, mRNA of the FCGR3B gene was found only in 92.0% (115/125) of cases. In tumors classified as pT1, the mRNA content of the FCGR3A gene was significantly lower than that in tumor samples of pT₃ size. There was the significant increase in the mRNA content of both genes with an increase in tumor grade, as well as in the cases with distant metastases. The presence of a tumor thrombus in the inferior vena cava system was accompanied by a significant increase in the mRNA content of the FCGR3A gene.

Conclusion: In tumor tissue samples from patients with clear cell renal cancer, the predominant production of the FCGR3A mRNA was observed in comparison with the FCGR3B mRNA. The revealed relationship of an increased amount of the FCGR3A mRNA and, in some cases, the FCGR3B mRNA with a number of clinical and morphological factors enables to consider the mRNA level of the genes as new monitoring biomarkers.

The aim of the study was to study the complex biomechanics of the aortic valve prosthesis and to analyze the effect of frame mobility on the stress-strain state and geometry of the valve leaflet apparatus using a numerical simulation method, which reproduces the qualitative and quantitative results of its bench tests.

Materials and methods: The object of the study was a commercial valve bioprosthesis UniLine (NeoCor, Russia), a three-dimensional mesh of which was obtained on the basis of computer microtomography with a subsequent analysis of its stress-strain state in the systole- diastole cycle by the finite element method in the Abaqus/CAE medium. The simulation was validated by comparing the results of numerical and bench simulation on the ViVitro Labs hydrodynamic system (ViVitro Labs Inc., Canada).

Results: The method proposed in this study to simulate the mobility of commissural struts by including elastic connectors of adjustable stiffness in the calculation made it possible to reproduce the qualitative effects of the valve leaflet work observed in the bench experiment. The bioprosthetic orifice area in the systolic phase corresponded to the values obtained in the hydrodynamic system throughout the entire systole-diastole cycle. The analysis of the stress-strain state has shown the fundamental difference in the distribution of the von Mises stress fields depending on the numerical experiment design: the concentration of high amplitudes in the area of commissural struts and the central part of the free edge. However, quantitatively, the stress values reached the maximum of 0.850-0.907 MPa (0.141-0.156 MPa on average), which is below the ultimate strength of the biological material.

Conclusion: The results of this study with the validation performed allowed us to conclude that adequate results of modeling the biomechanics of the heart valve leaflet bioprosthesis based on the finite element method can be achieved by using a high-resolution model with the imposition of elastic connectors in the area of commissural struts. Taking into account the mobility of the frame struts of the heart valve prosthesis is decisive in relation to the final geometry of the valve apparatus and can act as a negative factor in case of a highly elastic material of the valve apparatus. The simulation method presented can be used to optimize the leaflet apparatus geometry of heart valve prostheses from the standpoint of assessing the distribution of the stress-strain state.

The aim of the study is to develop methods for the differentiation of mutations in the BRAF codon 600 and to increase the sensitivity of the K601E mutation detection.

Materials and methods: The nucleotide sequence of the BRAF codons 592-602 was identified using the PyroMark Q24 genetic analysis system. The mutations search in codon 600 was conducted using the 600-S primer in line with the following order of adding nucleotides: GCTGTCАTCTGCTAGCTAGAC (corresponding to nucleotides 1799-1786). The K601E mutation was detected using the 601-S primer in line with the following order of nucleotide addition: GCTACTCACTGTAG (corresponding to nucleotides 1801-1793). The analytical characteristics of the proposed methods for somatic mutations' detection were determined using dilutions of plasmid DNA samples containing the BRAF gene region without mutations or with one of the following mutations: V600E, V600R, V600K, V600M, and K601E. Validation was performed on 132 samples of biological material obtained from the thyroid nodules.

Results: The developed methods allow to determine 2% of the V600E or V600M mutations, 1% of the V600K and V600R mutations, and 3% of the K601E mutations in samples with high DNA concentration; it is also possible to confidently detect at least 5% of the mutant allele for all mutations in low concentration samples (less than 500 copies/PCR). During biological material testing, 53 samples with the V600E mutation were detected; the proportion of the mutant allele was 4.9-50.0%.

Conclusion: A complex of methods for determination of the nucleotide sequence of the BRAF codons 592-601 and the algorithm for testing samples and analyzing mutations in the BRAF codons 600-601 was developed. The method provides sufficient sensitivity to detect frequent mutations in codons 600 and 601 and allows them to be precisely differentiated.

The aim of the study was to select the optimal method for creating surgical porcine dermis-based biomaterials and to assess their biological safety.

Materials and methods: To create xenodermal biomaterials, the native skin of a 4-month-old Landrace pig was used. The porcine dermis was processed with saline (protocol No.1), peroxide-alkaline (protocol No.2), and alkaline (protocol No.3) solutions. The obtained samples were stained with hematoxylin-eosin and a DAPI fluorescent dye. Quantitative DNA analysis and assessment of cytotoxicity by the LIVE/DEAD assay were also performed. Samples were implanted/injected subcutaneously to 6-month-old male Wistar rats (n=30) weighing 260±20 g and explanted on day 14 of the experiment. Histological sections were stained with hematoxylin-eosin. Computer morphometry was performed using GraphPad Prism v. 6.04.

Results: Samples of surgical materials obtained according to the three protocols had different physical characteristics: dermis treated according to protocol No.1 was dense and white in color after processing; samples processed by protocol No.2 were transparent and dense, and samples treated according to protocol No.3 had transparent gel-like structures. Histological analysis has shown oxyphilicity and extracellular matrix structure loss in all samples, and DAPI staining has revealed the destruction of cell nuclei. Nevertheless, DNA amount in the samples processed according to protocol No.1 did not meet the established quality criterion for decellularization (50 ng/mg dry weight). Further cytotoxicity assessment in vitro and in vivo was carried out only for samples fabricated according to protocols No.2 and No.3. According to the LIVE/DEAD analysis, both samples were not cytotoxic. On day 14 after the subcutaneous sample implantation, no signs of suppuration and immune rejection were found in the animals.

Conclusion: To obtain surgical materials in the form of bioplastic coatings, it is recommended to use alkaline-peroxide treatment of the dermis, while hydrogel coatings are produced by alkaline hydrolysis.

Schizophrenia is a socially significant mental disorder resulting frequently in severe forms of disability. Diagnosis, choice of treatment tactics, and rehabilitation in clinical psychiatry are mainly based on the assessment of behavioral patterns, socio-demographic data, and other investigations such as clinical observations and neuropsychological testing including examination of patients by the psychiatrist, self-reports, and questionnaires. In many respects, these data are subjective and therefore a large number of works have appeared in recent years devoted to the search for objective characteristics (indices, biomarkers) of the processes going on in the human body and reflected in the behavioral and psychoneurological patterns of patients. Such biomarkers are based on the results of instrumental and laboratory studies (neuroimaging, electro-physiological, biochemical, immunological, genetic, and others) and are successfully being used in neurosciences for understanding the mechanisms of the emergence and development of nervous system pathologies. Presently, with the advent of new effective neuroimaging, laboratory, and other methods of investigation and also with the development of modern methods of data analysis, machine learning, and artificial intelligence, a great number of scientific and clinical studies is being conducted devoted to the search for the markers which have diagnostic and prognostic value and may be used in clinical practice to objectivize the processes of establishing and clarifying the diagnosis, choosing and optimizing treatment and rehabilitation tactics, predicting the course and outcome of the disease. This review presents the analysis of the works which describe the correlates between the diagnosis of schizophrenia, established by health professionals, various manifestations of the psychiatric disorder (its subtype, variant of the course, severity degree, observed symptoms, etc.), and objectively measured characteristics/quantitative indicators (anatomical, functional, immunological, genetic, and others) obtained during instrumental and laboratory examinations of patients. A considerable part of these works has been devoted to correlates/biomarkers of schizophrenia based on the data of structural and functional (at rest and under cognitive load) MRI, EEG, tractography, and immunological data. The found correlates/biomarkers reflect anatomic disorders in the specific brain regions, impairment of functional activity of brain regions and their interconnections, specific microstructure of the brain white matter and the levels of connectivity between the tracts of various structures, alterations of electrical activity in various parts of the brain in different EEG spectral ranges, as well as changes in the innate and adaptive links of immunity. Current methods of data analysis and machine learning to search for schizophrenia biomarkers using the data of diverse modalities and their application during building and i

The aim of the study is to substantiate the efficacy of new prognostic criteria in diagnosing non-alcoholic hepatic steatosis at early stages of its development.

Materials and methods: Patients with excessive body mass (n=26) and obesity (n=28) having different concomitant pathologies of the digestive organs have undergone a comprehensive examination including assessment of biochemical blood indices, ultrasound examination of the abdominal organs, dynamic hepatobiliscintigraphy, assessment of the comorbidity level as a whole (calculation of CIRS) and by the available pathology of the digestive organs.

Results: The ultrasound signs of hepatic steatosis have been found in all patients with obesity stage II and III, in 69.2% of the examined patients (95% CI: 42.37-87.32) with obesity stage I, in 30.8% (95% CI: 16.50-49.99) with excessive body mass, and in 13.9% of patients (95% CI: 6.08-28.66) with normal body mass. According to the ROC analysis, the predictors of hepatic steatosis development in patients with excessive body mass and obesity are BMI (>31, р<0.0001) and the number of digestive organ illnesses (more than 4 diseases, p<0.0001). On the basis of the data obtained, a logistic model has been developed in the form of the regression equation permitting us to predict the groups of patients with a low or high degree of risk of hepatic steatosis. The analysis of dynamic hepatobiliscintigraphy has revealed deceleration of the absorbing function of hepatocytes in patients with normal ultrasound images of the liver even in case of excessive body mass. The obtained results made it possible to develop a method of diagnosing fatty hepatosis with subsequent calculation of the functional hepatocyte activity index (FHAI) which helps not only establish functional disorders but identify the group of patients having the risk of developing these disorders. Normal ultrasound imaging of the liver and absence of the biochemical changes in the blood are not indicators of preservation of its functional activity, since the risk of functional disorders was found in 32.3% of cases (95% CI: 18.57-49.86) and reversible disorders in 19.3% (95% CI: 9.19-36.28) when FHAI was calculated for patients with normal body mass. With the increase of body mass, irreversible functional disorders of hepatocytes are observed in 80-100% of patients.Thus, the results obtained in the course of the investigation have confirmed the possibility of using new prognostic markers of hepatic steatosis for early diagnosis of non-alcoholic fatty liver disease.

Cerebral stroke is one of the leading disability causes among adult population worldwide. The number of post-stroke patients, who need rehabilitation including motor recovery, keeps growing annually. Standard motor rehabilitation techniques have a limited effect on recovering extremity motor defunctionalization. In this regard, in recent years, new technologies of post-stroke rehabilitation are being suggested. The present review summarizes the existing literature data on current techniques applied in patients with motor disorders at an early rehabilitation period of cerebral stroke. The current modern technologies are divided into the methods based on "interhemispheric inhibition" theory (repetitive transcranial magnetic stimulation, transcranial direct current stimulation), and on "mirror neurons" theory (virtual reality systems and brain-computer interfaces). The authors present the neurophysiological causes and feasible protocols of using the techniques in clinical practice, the clinical research findings due to the initial severity level of motor disorders and stroke age, as well as the factors contributing to the motor rehabilitation efficiency when using these methods.

The aim of this study was to evaluate the efficiency of local and integral methods of the assessment of the hemostasiological profile in sheep at various stages of implantation of a biodegradable vascular graft.

Materials and methods: The object of the study was the whole blood of sheep collected at the stage of premedication, during the intraoperative period, and in the early postoperative period. Thromboelastography was used to assess the kinetics of clot formation and changes in its viscoelastic properties in whole blood samples. The thrombin generation test was performed in platelet-rich plasma (PRP) and platelet-poor plasma (PPP) with the assessment of quantitative and temporal parameters. The platelet factor 4 concentration in PRP and PPP was measured by the enzyme immunoassay. The functional activity of platelets in PPP was assessed with inductors and without additional stimulation. Prothrombin complex activity, APTT values, thrombin time, fibrinogen concentration, antithrombin III and protein C activity, soluble fibrin monomer complexes, and fibrinolysis were determined in blood plasma.

Results: Multidirectional changes in the hemostasiological profile at various stages of vascular prosthesis implantation have been revealed. On the one hand, it is an increased prothrombogenic status, on the other hand, it is the development of hypocoagulation. Shortening of the R (blood coagulation time) and K (clot formation time) intervals and an increase in the angle parameter and maximum amplitude on the thromboelastogram in all the studied periods relative to the reference values, a significant increase in platelet factor 4 in PRP and increased platelet aggregation testified in favor of hypercoagulation. However, the quantitative parameters of the thrombin generation test and a number of coagulogram indicators pointed to hypocoagulation in the intraoperative and early postoperative periods.

Conclusion: The comparative analysis of local tests characterizing the state of hemostasis and indicators of integral methods demonstrated the advantages of the latter in assessing thrombotic risks during implantation of vascular grafts. Local tests are not sufficient to assess the dynamics of the coagulation process in real time and are not always sensitive to hypercoagulation. The use of integral methods will help to fill these gaps, make a timely diagnosis of hypercoagulability and minimize the risks associated with the implantation of vascular grafts in future.

The current clinical practice of assessing the quality and suitability of a donor liver for human transplantation does not exclude cases of primary graft dysfunction of the transplanted organ and, at the same time, leads to an unreasonable refusal to transplant a significant number of functionally suitable organs. In this regard, searching for new methods for additional objective assessment and monitoring of the state of donor organs in the peritransplant period is relevant. The aim of the study was to determine the clinical utility of monitoring interstitial concentrations of glucose and its metabolites to assess the viability and functional state of a donor liver before and after human transplantation.

Materials and methods: A retrospective observational single-center study included 32 cases of liver transplantation. Along with standard methods for assessing the initial function of grafts during the first week after surgery, interstitial (in the transplanted liver) concentrations of glucose and its metabolites were monitored. In 18 cases, the interstitial glucose metabolism was also studied during static cold storage (SCS).

Results: With the development of early allograft dysfunction (EAD), compared with the uneventful post-transplant period, statistically significantly higher interstitial lactate concentrations were observed as early as 3 h after reperfusion: 12.3 [10.1; 15.6] mmol/L versus 7.2 [3.9; 9.9] mmol/L (p=0.003). A value above 8.8 mmol/L may be considered as a criterion for the immediate diagnosis of EAD (sensitivity - 89%, specificity - 65%).Interstitial lactate concentration at the end of SCS and the area under the "lactate concentration-SCS duration" curve were associated with the initial graft function. Values of these parameters greater than 15.4 mmol/L and 76.1 mmol/L·h, respectively, with a sensitivity of 100% in both cases and a specificity of 77 and 85%, may be used to assess the risk of primary EAD.

Conclusion: Monitoring of interstitial concentrations of glucose and its metabolites, primarily, lactate, is an objective additional method for the assessment of the donor liver viability both during SCS and in the early postoperative period.

Chronic resuscitation patients who have survived the acute phase of a disease represent a fast-growing cohort of patients requiring specialized medical assistant in intensive care and resuscitation units (ICRU) for several months or years. The term "chronic critical illness" (CCI) was proposed for such patients in the mid-80s of the last century. Patients with CCI make up from 5 to 20% of ICRU. Over time, they develop homeostasis disorders resulting in multiple organ failure and death. Mortality in CCI exceeds that of the majority of malignant neoplasms and functional dependence remains in most of survivors. In the present review, the attempt is made to show the main links of CCI pathogenesis which, if acted upon, can prevent unfavorable outcome. The publications describing epidemiology of CCI, its outcomes, and clinical phenotype have been analyzed. Several researchers consider CCI as a result of persistent inflammation, immunosuppression, and catabolism syndrome. Some works show the importance of nutrition for ICRU patients. The role of gastrointestinal tract in CCI formation has been noted. The effect of intensive therapy on microbiota of the ICRU patients has been demonstrated. Microbiome disturbances in dysbiosis and sepsis have been considered, as well as the effect of intestinal microbiome on the distant organs. Post-intensive care syndrome is a significant constituent of CCI. The main sequelae of the syndrome, as well as the general questions of its prevention and treatment, have been denoted.