Comparison of laboratory methods for identifying members of the family Mycobacteriaceae

Background

The introduction of a method based on matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-ToF mass spectrometry) into the practice of laboratories significantly increased the identification of acid-resistant bacteria (ARB).

Methods

Seventy-four nontuberculous mycobacteria (NTM) cultures identified by deoxyribonucleic acid (DNA) hybridization, polymerase chain reaction, Sanger sequencing, and MALDI-ToF mass spectrometry.

Results

Analysis of the identification results obtained by the methods of DNA hybridization and Sanger sequencing showed a complete match only for 67.6% of samples of the total number of cultures included in the study. The partial match of the identification results was 68.9%. When comparing the results of the identification of 74 samples obtained by MALDI-ToF mass spectrometry to the results obtained by sequencing, full match of identification of Mycobacterium chimaera/Mycobacterium intracelullare, Mycobacterium porcinum/Mycobacterium peregrinum and Mycobacterium tuberculosis complex was found for 90.5% of the samples; the partial match of the results - for 4.1%.. DNA hybridization as a method for identifying NTM showed acceptable sensitivity and specificity; however, for mass spectrometry, a significantly higher sensitivity with comparable specificity was determined.

Conclusions

Mass spectrometry is an important element in the modern system of species identification of microorganisms. The optimization of sample preparation protocols and assessment of the impact on the identification of new techniques of cultivation of microorganisms can significantly improve the quality of identification of microorganisms from the ARB group. In this case, accurate species identification and the development of algorithms for its application will improve the diagnosis of diseases caused by ARB.

Application of chromogenic media for preliminary identification of acid-resistant bacteria

Background

The variety of morphological and cultural characteristics of acid-resistant bacteria (ARB) makes it possible to use microscopy and estimate the growth rate and pigment formation when cultivating on solid egg media for preliminary identification only as additional indicative methods. It is necessary to develop new approaches for the cultivation and primary identification of ARB isolated from the biological material. It will allow to obtain data on the prevalence, structure, epidemiological, and clinical features of infectious processes caused by opportunistic ARB.

Methods

Three hundred and sixty strains of ARB were isolated from the various biological materials obtained from the patients during the examination for tuberculosis. All biological material samples were negative on Mycobacteria tuberculosis complex. Species identification of all bacteria was performed by matrix-assisted lazer desorption/ion-ization time-of-flight mass spectrometry. The cultural characteristics of ARB were evaluated on a universal chromogenic media. As a selective additive, a mixture of bacitracin and polymyxin sulfate which had no effect on ARB was tested to suppress concomitant Gram-positive and Gram-negative microflora.

Results

Cultural characteristics were identified and described for all tested representatives of fast-growing nontuberculous mycobacteria (NTM), as well as for all types of nocardia, gordonia, and streptomycetes. Representatives of other genera of ARB on a universal chromogenic media gave meager growth or did not show it at all. When inoculated on a universal chromogenic media with a selective addition, 100% of the strains from the ARB group showed abundant or moderate growth. Incubation time for fast-growing species was up to 7 days; for slow-growing species, it was up to 28 days. Concomitant control strains of Gram-positive and Gram-negative bacteria on universal chromogenic media with selective growth additive did not show the growth.

Conclusions

The use of a universal chromogenic media allows to preliminarily identify NTM and other ARB by cultural characteristics. The addition of bacitracin and polymyxin sulfate does not reduce the growth properties of ARB, which can be used when working with both biological materials and for the isolation of pure ARB cultures from mixtures with other bacteria.

Hematosalivarian barrier: structure, functions, study methods (review of literature)

The human body consists of various systems (blood, tissues, extracellular fluid, intracellular contents) separated by biological membranes. Physiological barriers ensure the physico-chemical composition of the internal environment remains constant and protects the body from environmental changes. The permeability of the histohematic barrier depends on the concentration of substances in the blood, the body's condition, external influences, and a number of other reasons caused by stimuli coming from the external or internal environment. Information about the state of the regulatory systems of the body has its effect on specific chemoreceptors, which leads to the emergence of local and general physiological and biochemical processes. According to their localization, they distinguish between the hematoencephalic, hemato-placental, hemato-ophthalmic, and hemato-salivary barriers. Recently, the hematosalivary barrier, through which the selective entry of substances from the blood into the oral fluid is carried out, has taken a special place in the study. Its functioning depends on the processes occurring in the body, which is carried out by selective permeability for substances that determine the composition of the main internal environment of the body - blood. Hematosalivary barrier is an important link in maintaining homeostasis, which is reflected in the metabolic parameters of oral fluid.

Microflora of sputum and autopsy material of patients with COVID-19

The rapid spread of a new coronavirus infection in the country actualizes the conduct of bacteriological studies of clinical material obtained from the respiratory tract of patients with COVID-19. During the experiments, 230 sputum samples and 260 autopsy lung samples from patients with COVID-19 were analyzed. 946 high-risk strains were isolated and identified by MALDI-ToF mass spectrometry on a Microflex LT instrument (Bruker®). According to the results of bacteriological cultures of sputum, a predominance of gram-positive ones was revealed, amounting to 50.5% (222 strains) of the total number of isolated pathogens. However, falling into this group is manifested by natural representatives of the microflora of the human mucous membranes from the genera Streptococcus, Rothia and Lactobacillus (109 strains in total), which can be manifested by the detection of improper sputum collection, causing contamination by the substance of intense salivation and nasopharyngeal discharge. In turn, the "classic" gram-positive causative agents of pneumonia were detected much less frequently: S. aureus in 5 cases, S. pneumoniae in 6 patients. The causative agents in the order Enterobacterales are represented by 42 strains, among which the most likely species are K.pneumoniae (27 strains). In the group of non-fermenting gram-negative bacteria, A. baumanii (29 strains) prevailed, and P. aeruginosa was also identified in 2 cases. When analyzing the results of a microbiological study of autopsy material (lungs) of patients with COVID-19, significant differences in the qualitative and quantitative composition of the microflora were revealed, compared with sputum. In the group of gram-positive bacteria, 15 strains of the natural microflora of the mucous membranes were identified, while sensitive species dominated among gram-negative pathogens: K. pneumoniae (102 strains), A. baumanii (75 strains), P. aeruginosa (11 strains). Regular microbiological monitoring is essential for antibiotic therapy and prevention of secondary bacterial infection. In the event of a fatal outcome, the results of microbiological analysis of autopsy material can determine the cause of death of the patient.

Newborns from women infected with COVID-19: somatic and metabolic status

To date, there are limited data regarding manifestations of new coronavirus infection in infants born of SARS-CoV-2 infected mothers, so the aim of this study is to investigate somatic and metabolic status of newborn infants born to mothers diagnosed with COVID-19. The investigation was carried out on the bases of Laboratory Diagnostic Department of Samara Regional Clinical Hospital named after V.D. Seredavin and the Department of Fundamental and Clinical Biochemistry with Laboratory Diagnostics of Samara State Medical University. Under observation were 85 newborns, including 35 born of healthy mothers and 50 born of COVID-19 mothers.The somatic status of all newborns was assessed using the Apgar scale at the 1st and 5th minutes after birth. Also all newborns had general and biochemical blood tests and newborns from mothers with COVID-19 were tested for the presence of SARS-CoV-2 RNA in oral and nasopharyngeal swabs. Thus, the study of somatic status revealed that of 50 neonates from women infected with COVID-19, only 18% were practically healthy, the rest had signs of prematurity, hypotrophy, perinatal CNS damage, diabetic fetopathy, pulmonary atelectasis, delayed intrauterine development, asphyxia. The metabolic state is characterised by decreased haemoglobin and platelets, increased concentration of total protein, including C-reactive protein, high transaminase activity, decreased sodium and chloride content. These parameters of general and biochemical blood tests can be considered as indicators for the evaluation of the condition of newborns from mothers with COVID-19.

Molecular profile of oral fluid in new coronavirus infection

Oral fluid is an alternative biological material that confirms correlations with blood parameters in various pathological conditions of the body. In order to find a non-invasive approach to stratification of patients with COVID-19 disease, molecular biomarkers of the oral fluid have been determined in patients with moderate coronavirus infection in comparison with clinically healthy individuals. It has been shown that proteomic, carbohydrate, macro- and microelement profiles of the oral fluid in coronavirus infection can be used for diagnostics. The features of protein metabolism were revealed: an increase in the content of total protein, urea; increased activity of enzymes aspartate aminotransferase, gamma glutamyl transpeptidase, creatine phosphokinase, alkaline phosphatase; changes in carbohydrate metabolism, which is expressed by an increase in glucose and lactate levels, an increase in lactate dehydrogenase activity, sodium, chloride, calcium, magnesium, iron content.

[Blood group and human diseases (review of literature).]

AB0 blood group antigens were discovered over a century ago; however, it is still important to study their role in development of various pathological conditions. Today it is known that antigenic determinants of this blood group are present not only on erythrocyte membrane but also on other cells and tissues: platelets, gastrointestinal epithelium and salivary glands, respiratory system cells. In the last decade, a large number of studies have appeared to reveal the relationship between a specific disease and blood group type, meta-analyses have been published. Previously, the authors have studied the metabolic status, cell composition and coagulation profile of clinically healthy individuals for more than on 180,000 donations, that allowed to identify groupspecific features for each blood group. This review presents generalized data on the association of such pathological conditions as coronary heart disease, thromboembolic complications, tumors of various localizations, inflammatory and destructive oral diseases, psychiatric and some infectious diseases with the presence or absence of antigenic determinants A and B. Carriers of blood group 0 (I) are generally more resistant to diseases, with the exception of H.pylori-associated gastrointestinal diseases. Carriers of «antigenic» blood groups A (II), B (III), AB (IV) are more susceptible to development of infectious, cardiovascular and cancer diseases. The presented data demonstrate clinical significance of the definition of group typing not only for selection of blood and its components during transfusion and transplantation, but also for diagnostics, determination of risk group and tactics for treatment patients with different nosologies.

[The structure of conditionally pathogenic microflora, isolated from the urogenital tract of women with pathological course of pregnancy.]

The structure of the microflora of the urogenital tract of a woman is variable and diverse, changing its qualitative and quantitative composition can affect various physiological processes in the body of a woman, including the course of pregnancy. In this study, the results of cultures of 1415 samples of urine and cervical canal discharge of pregnant women were analyzed. Species identification was carried out by MALDI-ToF mass spectrometry using Microflex LT (Bruker) mass spectrometer. Gram-positive bacteria (69.5%) dominated the structure of the cervical canal microflora, among which Staphylococcus spp prevailed., Enterococcus spp. and Lactobacillus spp. Among gram-negative bacteria most often encountered microorganisms of the order Enterobacteriales, the predominant species among which was E. coli. Also, yeast-like fungi were isolated from the material of the cervical canal, their number was 11% of the total number of crops. Qualitative microbiological composition of urine was represented by gram-positive flora (68.7%), gram-negative flora (30.1%) and Candida fungi (1.2%). There is a significant predominance of coagulase-negative staphylococci (97.3%) over coagulase-positive (2.7%) in the structure of gram-positive microorganisms. The composition of gram-negative flora is mainly represented by bacteria of the order Enterobacteriales (71.4%). The study identified microorganisms that can cause postpartum complications and the development of inflammatory diseases of the newborn, which suggests the need for regular microbiological examination for pregnant women.

[Features of the metabolic composition of spermal plasma in different morphofunctional pathologies of the ejaculate.]

As part of the work, an assessment was made of the state of the metabolic characteristics of sperm plasma in various morphofunctional ejaculate pathologies. Physico-chemical, metabolic and morphological parameters of the ejaculate were evaluated. The diagnostic protocol included a standard sperm analysis with classification of ejaculate parameters and determination of biochemical parameters of sperm plasma on an automatic biochemical analyzer. The study of the qualitative and quantitative characteristics of metabolic parameters. The total number of surveyed was XX people. After studying the morphological features of the cell composition, the obtained samples were divided into four groups: samples with normospermia, samples with oligoasthenoteratozoospermia, samples with azoospermia, and samples with cryptozoospermia. In each group, the parameters of protein, carbohydrate, lipid and mineral metabolism were studied. As a result, it was found that with the progression of pathology, the catabolic mechanism of energy consumption begins to prevail, due to a decrease in the concentration in the sperm plasma of protein components, transaminases, as well as the growth of non-protein nitrogenous inclusions. It is noted that the growth of glucose, despite the inhibition of transmembrane routes of intake by reducing the concentration of alkaline phosphatase and lipid-transport systems, is associated with the forced inclusion of insulating mechanisms for the penetration of glucose into the sperm plasma from the blood through the hemato-sperm barrier. At the same time, an increase in the content of lipids in the sperm plasma, as well as the growth of creatinine in the initial stages of the development of pathology, can be characterized by a compensatory response aimed at maintaining the viability of minimal amounts of spermatozoa. Well, the disorder of mineral metabolism in general characterizes the violation of metabolic processes in all forms of ejaculate pathology. Identified features of the metabolism in the sperm plasma may further allow to identify more informative laboratory markers of male infertility.

[Blood group as a predictor of glycemia and lactatemia in critical condition patients.]

Hyperlactatemia is a dangerous metabolic shift, manifested in an increase in the blood lactate content above 2.2 mmol / l. Changes in the content of lactate affect the function of vital organs and systems, disrupting the course of biochemical processes. This condition accompanies a large number of clinical situations, also it is a major factor, worsening the clinical outcome and the patient's condition. The study of the characteristics of its occurrence and metabolic relationships helps to fulfill the diagnostic criteria for assessing the likelihood of an adverse outcome. The purpose of this study is to assess the variability of the content of lactate and glucose, as well as the glucose/lactate ratio, depending on the group of blood in the ABO system and the nosology of patients. 250 patients with various diseases whose condition required intensive care were examined, the middle age was 61.08 ± 13.6 years, and 446 practically healthy individuals who did not have acute somatic and infectious diseases, the middle age was 26.83 ± 1.46 years . We investigated the content of lactate and glucose, the glucose/lactate ratio, determined the belonging of the blood to ABO system. Statistical processing of the results was performed in the IBM SPSS Statistica 23.0. The data obtained indicate that patients with B (III) blood group have the highest lactate content in venous blood compared to the general population, and patients with AB (IV) blood group have the highest blood glucose level. In the group of patients with the highest median lactate content, the lowest glucose content was observed. The data presented demonstrate the importance of measuring and monitoring glucose, lactate, and their ratio in the management of patients in a life-threatening condition. Evaluation of metabolic variability depending on the different blood grouping of the ABO system in critical conditions involving hyperlactataemia can serve as an important tool in modeling a personalized approach to the patient.

Influence of dental prosthetics technology on the dynamics of early predictors of destructive inflammatory process in the periimplant zone

An objective assessment of the morphofunctional characteristics of the state of soft tissues and bone structures adjacent to the dental implant allows to control the dynamics of the processes of osseointegration in the jaw-dental implant system. The aim of the work was to investigate the level of the β-CrossLaps, С-reactive protein (CRP), osteocalcin markers after orthopedic treatment of patients using dental implant supported advanced dental restoration technologies, to perform a biochemical analysis of the oral fluid of patients after restoration using dental implants and new two-part dental implants. In patients of the index group (52 people), the removable prostheses with metal frame and fixing elements or the commercially available dental implant supported removable prostheses were installed. For the patients of the control group (12 people), the commercially available dental implant supported removable prostheses of acrylic plastics were constructed. For all the patients after 6 months the level of β-CrossLaps, CRP, osteocalcin markers in the oral fluid was analysed. In patients of the index group, the average content of β-CrossLaps was 0.0126 ± 0.002 ng/ml, in the control group it was 0.0147 ± 0.002 ng/ml. The average content of the CRP in patients of the index group was 0.358 ± 0.019 mg/l, in patients of the control group it was 0.78 ± 0.01 mg/l. In patients of the index group, the average content of osteocalcin was 1.46 ± 0.25 ng/ml, in the control group it was 1.98 ± 0.31 ng/ml. It has been shown that biochemical markers of the oral fluid can be used to predict complications after the dental implants installation. Restoration with two-part dental implants of modern design is associated with fewer complications.

[The indicators of basal metabolism in inflammatory syndrome bacterial origin: predictors of prognosis or the need for timely correction?]

The aim of the study was to determine the comparative significance of basal metabolism indicators and inflammatory process markers for the closest prognosis of patients in ICUs with systemic inflammation syndrome caused with infectious genesis. The paper presents the results of a retrospective analysis of the plan of treatment of 198 patients with confirmed clinical and laboratory signs of bacterial infection. The number of leukocytes, platelets, the percentage of lymphocytes, the concentration of procalcitonin, creatinine, bilirubin, C-reactive protein, acid-base balance values were determined in patients. Patients were assessed on a SOFA scale. The type of biomaterial for microbiological research was determined depending on the intended source of infectious inflammation. Identification of the isolated microorganisms was carried out using the MALDI ToF mass spectrometry method, followed by determination of antibiotic resistance. Empirical antibiotic therapy was prescribed upon admission of the patient to the ICU. Patients were switched to etiotropic antibacterial therapy after 48 hours, taking into account the results of a microbiological study. Determination of basal metabolic rate was carried out using the method of indirect calorimetry (CCM Express, Medical Graphics) with the calculation of basal metabolism, respiratory coefficient, absolute and relative amount of macronutrients. The calculation of the protein was made on the basis of the nitrogen level of the daily urine urea. Logistic analysis (ROC analysis) revealed that the antibacterial therapy strategy used, age, gender of patients, tinctorial properties of microorganisms isolated from patients, do not affect the nearest prognosis of the disease. On the contrary, SOFA score, the concentration of procalcitonin in the blood, and such parameters of the metabolic status as the need for kilocalories per kilogram of actual body weight and the percentage of protein calories significantly affect the nearest prognosis of the disease. The percentage of calories derived from protein metabolism, in the main exchange has a high reliable predictive value. The results of the study confirm the importance of adequate nutritional therapy in the treatment of patients with infectious inflammatory syndrome, including the calculation and correction of protein loss and total daily calorie.

[Diagnostic possibilities of modern biochemical study of sputum from patients with cystic fibrosis (literature review).]

The review presents the pathobiochemical and molecular mechanisms of sputum formation in patients with cystic fibrosis associated with the pathophysiological features of the disease. Statistical data on the prevalence of this pathology in the world and in the Russian Federation are presented. The mechanisms of sputum formation and disorders of the mucociliary apparatus, leading to the accumulation of viscous bronchopulmonary secret in cystic fibrosis, are considered. The principles of the relationship between the rheological properties of sputum and the formation of inflammation in the lungs with the addition of a concomitant specific microflora in the bronchopulmonary system in patients with cystic fibrosis are presented. Describes the opportunities for biochemical studies of sputum of patients with this pathology: determining the activity of enzymes (myeloperoxidase), the content of proteinase inhibitors (α2-macroglobulin and α1-antitrypsin) and proinflammatory cytokines (IL-8 and TNFa), concentrations of iron and ferriferous proteins (lactoferrin and ferritin), which makes biochemical studies of sputum available, non-invasive, quick and cost-effective method of diagnosis, which can be widely used as an auxiliary laboratory method and makes it possible to use these metabolites as diagnostic markers to assess the severity of inflammation and infection of the lower respiratory tract and predict the development of respiratory complications in patients with cystic fibrosis.

[Polyresistent microflora in the structure of microorganisms divided from blood of patients of the general hospital.]

The aim of our research was to evaluate the structure and the determination of the phenotypes of antibiotic resistance of microflora isolated from patients' blood in a multidisciplinary hospital during the period from 2013 to 2017. The material was taken into BacT / ALERT bottles containing nutrient media, followed by incubation of blood. In case of a positive result, the material from the vials was dispersed into dense nutrient media. Species identification was carried out using commercial biochemical API test systems and MALDITOF mass spectrometry. The antibiotic resistance of the isolated microorganisms was evaluated by a classical disc-diffusion method. From 2013 to 2017, 3504 blood tests were performed, of which 16.8% were positive. Of the isolated strains, 69.6% were Gram-positive, 27% were Gram-negative, and 3.4% were fungi. The structure of Gram-positive bacteria included Staphylococcus spp - 71.46%, Enterococcus spp. - 21.22% and Streptococcus spp - 7.32%. Staphylococcus aureus (47,8%) prevailed among staphylococci (in 62.14% were methicillin-resistant) and coagulase-negative staphylococci. Among the genus Enterococcus spp, Enterococcus faecalis prevailed (27% resistant to macrolides, 14% to fluoroquinolones) and Enterococcus faecium (69% resistant to penicillins, fluoroquinolones, macrolides). Streptococcus pneumoniae, Streptococcus pyogenes and streptococci from the group of alpha-greening were isolated from streptococci. Clinically significant types of streptococci in 33.3% were resistant to macrolides and fluoroquinolones. In the structure of gram-negative bacteria, Enterobacteriaceae prevailed - 71.07% (Klebsiella pneumoniae, E. coli); the proportion of non-fermenting Gram-negative bacteria (NFGOB) was 28.93%. Most Gram-negative bacteria were producers of extended-spectrum beta-lactamases (BLBRs). In NFGOB structure allocated Acinetobacter baumanii - 56,5% (81% polyresistant), Pseudomonas aeruginosa - 30,4% (50% - Carbapenemase Producing Organisms), Stenotrophomonas maltophilia - 10,9%. Thus, microbiological research in septic blood conditions is an integral part of the diagnostic search, selection of etiotropic therapy and monitoring of its effectiveness.

[The impact of lipid metabolism on the rate of aging of patients with arterial hypertension.]

Now atherosclerosis is even more often positioned as the natural hereditary determined process determining the rate of aging of an organism and life expectancy. Research objective: to study correlation interrelations between indicators of a lipidic profile and rate of aging of men with an arterial hypertension. We have conducted a one-stage research of 123 male patients (middle age 52,4±0,60 years). The main group (I) was made by patients with the arterial hypertension (AH) of the II stage of high risk. The control (II) group was made by 60 patients without kliniko-tool symptoms of cardiovascular pathology. The research of a lipid profile was conducted on the biochemical autoanalyzer «Humastar 600» (Human GMBH, Germany) with studying of the general cholesterol (OHS), lipoproteid of the low density (LDL), lipoproteid of the high density (LPVP), triglycerides (TG), calculation of the aterogennost coefficient (AC) was also carried out. Rate of aging decided on the basis of integrated assessment of the biological age (BA) on use of a technique of the Kiev Scientific Research Institute Gerontology. Patients with AG have a direct correlation dependence of moderate force between biological age and lipid exchange traces with OHS indicators (r=0,364, p=0,003), LDL (r=0,359, p=0,004), TG (r=0,324, p=0,010) and KA (r=0,488, p<0,001). The return correlation communication is noted with LPVP (-0,446, р<0,001). Patients have groups of control the direct correlation dependence of moderate force of BV and lipidic range is noted also for atherogenous fractions of lipoproteid and KA, feedback - for LPVP (-0,623, р<0,001). On the basis of the carried-out mathematical modeling formulas for determination of biological age of the considered groups of patients taking into account indicators of a lipidic profile have been made. The correlation analysis which is carried out by us reflects a dislipidemiya contribution to development of the accelerated aging of an organism, and the executed mathematical modeling allows to carry out diagnostics of the accelerated aging of patients by means of indicators of lipid exchange.

[Molecular markers of the oral mucosa damage in patients with leukemia.]

The criteria for early manifestations of mucosal lesions in patients with acute and chronic leukemia are distinguished: in the absence of complaints and changes in the index assessment of the oral cavity, a block of initial dental signs in the form of edema of the tongue and the smoothness of its papillae, pallor of the oral mucosa in patients with leukemia. In theoral fluid of patients with the initial signs of dental pathology in acute leukemia, a specific spectrum of disorders was established in the form of the lowest antibody level of immunoglobulin A class to transglutaminase in combination with a high amount of Ig G antibodies to transglutaminase - 8.73 ± 0.92 U / ml, which maximal level exceeds the reference limits by almost 4 times (38.80 U / ml) - that indicates structural changes in the connective tissues of the oral cavity. Under the influence of chemotherapy in these patients, the inversion of clinical manifestations of dental pathology was noted: stomatitis II (medium) severity is formed, bypassing I degree, accompanied by a 4-fold increase of IgA antibodies to transglutaminase (4.03 ± 0, 77 U / ml, p < 0.05) in the oral fluid of patients with acute leukemia and 2.5 times for chronic leukemias (3.24 ± 0.47 U / ml, p < 0.05) compared to pre-treatment period. In this regard, it is recommended to determine the content in the oral fluid for antibodies to transglutaminase in patients with leukemia for verification of the degree of inflammatory-destructive process and its recovery. The peculiarity of immunological shifts in stomatitis of the 1st degree of severity is the highest level of IgG antibodies to transglutaminase (9.98 ± 1.50 U / ml) in the oral fluid, and at II-III degree the molecular manifestations of damage are smoother, which indicates the depression of immune processes.

[Coagulation test features depending on the AB0-blood groups system antigenic composition.]

The maintenance of normal blood flow through the vessels is the result of the coordinated work of the coagulation and anticoagulation systems of our body. The balance of this system depends on many factors, including endothelial, humoral, platelet ones, however, we still lack knowledge about the effect of antigenic determinants on the state of the hemostatic system. This study is devoted to assessing the effect of the presence and absence of antigens on the AB0 system, presented on erythrocyte and platelet membranes, on hemostatic parameters. The study was conducted in the Clinics of Samara State Medical University and consisted of127 clinically healthy individuals who underwent a general analysis and biochemical blood analysis, 52 people with the most stable indicators of cell composition and metabolic profile were selected for a coagulation test, including determination of the activity of coagulation factors and routine tests. A significant decrease in the activity of the VIII and VII coagulation factors was revealed, as well as an increase in the prothrombin time in patients with 0 (I) blood group compared to the "antigenic" blood groups. The presence of biological variation for indicators of external and internal coagulation paths was noted, depending on the group of blood belonging to the AB0 system. The findings suggest that there is an increased susceptibility to bleeding in patients with 0 (I) blood groups due to the absence of antigenic determinants on the cell membrane, while for "antigenic" blood groups, on the contrary, there is a susceptibility to thrombosis due to increased activity of the components of the coagulation system.

[Metabolism processes and mechanisms of regulation of platelet activity (review of literature).]

Platelets play fundamental role in ensuring the hemostatic function in blood. In addition to this canonical function, the blood plates play angiotrophic, immunological, transport role, participate in the activation of plasma hemostasis, retraction of a blood clot, and can record circulating immune complexes. The review article presents current data on the structure and conjugation of molecular rearrangements of platelet ultrastructures associated with the functioning of an open canalicular platelet system, a dense tubular system, and a platelet cytoplasmic membrane. The main types of resting platelet metabolism, and the processes underlying the activation of platelets associated with the enhancement of carbohydrate and fatty acid catabolism are characterized, as well as some signaling pathways that regulate processes of induction of platelet aggregation. The data show the value of lipid components of activated platelet membranes, including phospholipids of various classes, glycolipids and cholesterol. The role of regulatory processes associated with the non-covalent modification of certain platelet proteins with fatty acids is reflected. Fundamental questions of platelet metabolism are relevant nowadays and require a combined approach of studying them, which can potentially solve many problems of clinical laboratory diagnostics, pathobiochemistry, and pharmacology. In preparing the review, we used sources from international and russian databases: Scopus, Web of Science, RSCI.

[The effect of hyperglycemia on indices of biochemical blood analysis in vitro.]

The purpose of study was to detect possible deviations between the results of biochemical analysis of blood and true values in conditions of hyperglycemia in vitro and dependences of the given alterations from group belonging of analyzed blood. The biochemical analysis was applied to blood samples of patients with various blood groups according system AB0 in conditions of normo- and hyperglycemia in vitro. The criterion for choice was established the content of main biochemical indices of blood (total protein, total bilirubin, glucose, total cholesterol, urea, creatinine, activity of hylaninamitotransferase (ALT), aspartataminotransferase (AST), lactatedehydrogenase (LDG)) within the reference limits. The hyperglycemia was developed in vitro using 5% glucose solution and corresponded to 20,49±0,05 and 46,37±0,63 mmol/l. The content of total protein and total cholesterol turned out to be the most stable indices. The effect of increased level of glucose to following analytes was established: total bilirubin (+10,5%), ALT activity (±13,4%), AST activity (+11,1%) and creatinine (+51,4%). The alterations of indices up to level of ±10% and higher are clinically significant and have to be taking into account by physicians of clinical laboratory diagnostic and clinical physicians during interpretations of the results of biochemical analysis of blood for evaluation of true picture of condition of patient. The AB0-group specific characteristics of biochemical analysis of blood are established in conditions of hyperglycemia. The hyperglycemia is an interfering factor during implementation of laboratory analysis that is especially actual at interpretations of results of biochemical analysis of blood in patients of reanimation department and individuals suffering of persistent and severe diabetes mellitus with its complication with nephropathy. Besides, the established group-specific characteristics of hyperglycemia effecting the results of biochemical analysis of blood can be accounted in development of standards and guidelines of personified medicine.

[Evaluation of vitamin status of workers of oil-processing enterprises (Samara Region) according to the data on vitamin consumption and blood serum level]

Vitamin status of 77 employees of oil refineries (39 men and 38 women aged 22 to 62 years, body mass index - 25.0±4.7 kg/m²) has been assessed in autumn. The sufficiency with vitamins A, E, D, B₂, B₁₂, folate and beta-carotene was evaluated by determination in blood plasma, daily intake of vitamins B1, B2, niacin, C, A and betacarotene was calculated by frequency of food consumption during previous month. All surveyed were sufficiently supplied with vitamins A, B12 and folate (reduced level was detected in 0-2.6%). The content of tocopherols referred to triglycerides was reduced in 33% of the workers, in men it was 2 fold more likely (p<0.05) than in women (43.6 vs 21.1%). Vitamin D insufficiency took place in 23.4% of individuals, vitamin B₂ and beta-carotene - in 44.2%. A reduced blood plasma content of one vitamin was detected in 39.0% of the surveyed, while two vitamins - in 24.7% persons, 2.2 fold more often (p<0.05) in men than in women. Multivitamin insufficiency was detected in 10.4% of workers. Reduced blood plasma level of at least one vitamin-antioxidant was detected in 46.8% (in 61.5% of men and 31.6% of women, p<0.05). 26.0% of surveyed were provided with all 6 vitamins and beta-carotene. Reduced relative to RDA daily intake of antioxidant vitamins (ascorbic acid and beta-carotene) was observed in 64.9 and 100% of individuals, B group vitamins (niacin, B₂ and B₁) - in 48.1-64.9%, vitamin A - in 42.9%.

[Assessment of vitamin status of the workers of Samara thermal power plant according to data on vitamin intake and their levels in blood]

Sufficiency of 58 employees of a thermal power plant (47 men and 11 women aged 21 to 64 years, body mass index - 27.0±5.8 kg/m²), with vitamins A, E, D, B₆, B₁₂, folic acid and carotenoids (content in the blood plasma) and vitamin C (urinary excretion) was conducted in winter (February 2015). All surveyed workers were sufficiently supplied with vitamins A, B₆, B₁₂ and folic acid (a reduced level was detected in 0-9%). Insufficient supplying with vitamin E had 19% of the workers (and only men), vitamin C - 44%, vitamin D - 61%, carotenoids - 93%. Only 5% persons were sufficiently provided with all 6 vitamins. A combined deficiency of two vitamins had 38% of them, three - 22%, four - 16%. Simultaneously reduced plasma level of two antioxidants was observed in 36% of subjects, three - in 12%. Significant positive correlation (p <0.05) was detected between plasma levels: total cholesterol and retinol and β-carotene; tocopherol and total cholesterol, triglycerides, low density lipoprotein cholesterol; between the concentration of vitamin D, and high density lipoproteins; levels of retinol and tocopherol and β-carotene. In parallel intake of vitamins C, A, B₁, B₂ and niacin has been assessed by calculation of the frequency of food consumption during the previous month. Reduced relatively recommended daily intake of vitamins A, C has been found in approximately half of the surveyed, niacin, vitamin B1 and B₂ - in 70-80%. Comparison of the data on the availability of vitamins C and A, obtained by calculation of vitamin intake and biochemical methods gave identical results in 55 and 60% of cases, correspondingly. The lack of vitamins has been detected more frequently by assessing dietary intake.

[Modeling role of pyruvate in the processes of protein-protein interaction]

Using the ABO antibody-antigen model the influence of natural metabolite pyruvate on the antibody interaction with of erythrocyte antigens, defining their group specificity has been investigated. Before agglutination reaction erythrocytes of A(II)-AB(IV) blood groups, monoclonal anti-A and anti-B antibodies were incubated with sodium pyruvate. Visualization of agglutinates was performed by means of flow cytometry and laser scanning confocal microscopy. Computer-aided prediction of the spectrum of biological activity of pyruvate by a PASS program proposed major regulatory pathways, in which pyruvate may be involved. It has been demonstrated that pyruvate can regulate the intensity of antigen-antibody interaction. These results suggest the possibility of using small molecules, for example pyruvate, as molecular probes and prospects of the use of erythrocytes with antigenic determinants of the ABO system expressed on their membranes for studies of protein-protein interactions due to convenient visualization and possibility of quantitative evaluation of this process.