Diagnostic characteristics of serological tests for the detection of SARS-CoV-2 cases.

To study the diagnostic characteristics of test systems for detecting antibodies to SARS-Cov-2. We studied the diagnostic characteristics of two test systems for detecting antibodies to SARS-Cov-2, registered in the Russian Federation. The first test system is a kit for detecting total antibodies to SARS-Cov-2 using immunochemiluminescence analysis on the «Cobas e 411¼ analyzer («Roche Diagnostics¼, Germany). The second test system is a kit for detecting IgM and IgG to SARS-Cov-2 («Core Technology Co., Ltd¼, China) by immunochromatographic analysis. The biological material for the study was blood serum. We assessed: diagnostic sensitivity, diagnostic specificity, and predictive value of positive and negative results. In the test system for detecting total antibodies to SARS-CoV-2, using an IHLA, the diagnostic sensitivity and specificity were 100%; the predictive value of positive and negative results was 100%. In the test system for the detection of IgM and IgG to Sars-CoV-2, using IHA, diagnostic sensitivity for IgM and IgG were 100%; diagnostic specificity for IgM - 60%, for IgG - 72%; predictive value of a positive result for IgM - 60%, IgG - 68,18%; predictive value of negative results for IgM and IgG - 100%. The best diagnostic characteristics were found in the test system for the detection of total antibodies to SARS-Cov-2, which must be taken into account when deciding whether to purchase test systems for the detection of antibodies to SARS-Cov-2.

[Down's syndrome with congenital acute leukemia and congenital heart disease]. / Sluchai sindroma Dauna s vrozhdennym ostrym leikozom i vrozhdennym porokom serdtsa.

OBJECTIVE: To report a rare case of Down's syndrome with congenital acute leukemia and congenital heart disease. MATERIAL AND METHODS: We have retrospectively analyzed an electronic database of patients aged 0-17 years who underwent inpatient treatment of congenital heart disease at the Federal Center for Cardiovascular Surgery for the period from January 1, 2010 to December 31, 2018. Incidence of Down's syndrome in children with congenital heart defects was 5.36% of the total number of children with congenital heart defects. No gender differences were identified. The most common congenital heart defects were ventricular septal defect, atrioventricular septal defect, atrial septal defect, patent ductus arteriosus, tetralogy of Fallot. Down's syndrome and congenital heart disease were diagnosed prenatally in 33 out of 319 patients. A rare case of Down's syndrome combined with congenital heart disease and acute leukemia is described. Treatment outcome was unfavorable. CONCLUSION. S: Evere concomitant diseases in a child with Down's syndrome determine high postoperative morbidity and mortality. Prenatal diagnosis of Down's syndrome via screening of pregnant women for ultrasound and biochemical markers of this pathology is required.

Comparative analysis of the impact of blood collection systems on the results of the study of indicators hemostasis system.

Comparative analysis of the impact of blood collection systems on the results of routine coagulation tests. The aim of this study was to conduct comparative analysis of the effects of blood collection systems on the results of routine coagulation tests. The study involved practically healthy women over 18 years of age female (n=30). Inclusion criteria: practically healthy individuals. Exclusion criteria: taking non-steroidal anti-inflammatory drugs, or oral contraceptives. Blood collection was carried out in the following systems: 1 system-Vacuette Premium,2 system- Improvacuter, 3 system- BD Vacutainer® Plus. Before and after centrifugation, visual assessment of tubes was performed.No signs for the presence of clots, hemolysis, or insufficient filling was observed. In each sample we measured prothrombin time (PV, sec), activated partial thromboplastin time (APTT, sec), and fibrinogen (F, g/l) by clotting method on the automatic coagulometer «Sta Compact¼ («Diagnostica Stago¼, France). The results of laboratory analyses were processed using parametric and non - parametric statistics using The Statistica 12.0 software. At the preanalytical laboratory stage, there were no differences when using systems for blood sampling: the clots and hemolysis were not detected in the samples, the level of filling of the sistems was sufficient. Comparative analysis revealed small, though statistically significant, differences for: PT when comparing Improvacuter wiht Vacuette Premium or BD Vacutainer®; APPT when comparing Improvacuter wiht Vacuette Premium. No differences were observed for Fg levels. Our results support the data available in the literature on the effects of blood-taking systems on hemostasis , which should be taken into account when purchasing blood collection systems.

[Improving the quality of hematological studies using sigmametry.]

The purpose - evaluated the quality of the implementation of hematology studies using sigmametry. Studies were perfomed at the Federal state budgetary establishment "Federal center cardiovascular surgery". The data were collected in the period for 2017 y. The following hematology parameters were monitored daily: white cells, red blood cell, platelet, hemoglobin. For conducting laboratory quality control we used certified three-level (Level 1 (low) , Level 2 (normal)and Level 3 (High)) control material "CBC-XE Hematology control" ("R and D Systems", USA). The study of blood hematology parameters was carried out on an automatic hematology analyzer "Sysmex XT- 2000i" and "Sysmex XT- 1800i" ("Sysmex Corporation", Japan). Sigmametry values were calculated the CV (coefficient of variation), the systematic error (Bias) and the total allowable analytical error (TE max). On the analyzer «Sysmex XT- 2000i¼ sigma values for platelet were between 3 and 4. For white blood cells, red blood cells, hemoglobin the value of the sigma was greater than 4. On the analyzer «Sysmex XT- 1800i¼ for platelet, white blood cells, red blood cells, hemoglobin the value of the sigma was greater than 4. Based on the results obtained, we drew conclusions on the choice of control material and the frequency of the internal laboratory quality control. The introduction of sigmametry in the daily activities of clinic laboratory will improve the quality of the determination of platelet, which requires further observation.

Complex formation with protamine prolongs the thrombin-inhibiting effect of DNA aptamer in vivo.

Antithrombin DNA aptamersRE31 are single-chain oligonucleotides that fold into three-dimensional forms allowing them to bind the enzyme with high affinity and inhibit its activity in vivo. They are rapidly degraded by a nonspecific nuclease, and, to prolong the lifetime of the aptamer DNA in the bloodstream, it is necessary to coat it with a polymer envelope. A new approach to solving this problem based on preparation of DNA-polyelectrolyte complexes with a minimal particle size that can circulate with blood flow. In our experiments, the negatively charged aptamer DNA RE31 was coated step-by-step with positively charged protamine. They had protamine/aptamer ratios of 0.2/1 and 0.4/1 by charge, with particle size being determined by dynamic light scattering. The aptamer DNA-protamine complexes were administered to rats, followed by ex vivo analysis of blood samples. The results showed that prothrombin time (PT) increased by a factor of 5.6-6.7 within 2 h after injection and remained at approximately the same level for 6 h, while injections of pure protamine did not lead to any noticeable change in clotting time. Thus, complexation with protamine proved to prolong the inhibitory activity of the RE31 DNA aptamer.

[Novel immunoassay for laboratory assessment of the erythron state].

The paper presents the results of a study of embryonic or primitive hemoglobin (HbP), by using the authors' developed immunodiffusion monovalent test system in the neonatal umbilical blood and in girls than in the boys. HbP was also detected in patients with erythema (66.7%) and acute myeloleukemia (22.22%), it was absent in those with chronic lympholeukemia. The findings suggest that the early antenatal type of hemoglobin is likely to be of diagnostic value in assessing the degree of hypoxia in the differential diagnosis of hemoblastoses.

[Steroid-binding protein levels in breast cancer patients].

Blood levels of sex hormone-binding globulin (SHBG), transcortin and pregnancy-related alpha2-glycoprotein (PalphaGP) were assayed using commercial kits for alpha-protein analysis in 223 breast cancer patients and 180 healthy women. Elevated concentration of SHBG was characteristic of both the luteal stage of menstrual cycle and menopause. It occurred chiefly in patients under 59 whereas at older age no differences from control were observed. Blood- transcortin in tumor patients was significantly lower than in control; conversely, PalphaGP concentration was higher irrespective of age. Since steroid-binding protein levels in the blood of breast cancer patients appeared to differ from those in healthy women, relevant data should be considered when hormone-metabolic status of reproductive and menopausal patients is identified.

[Immunochemical tests for the risk of inflammatory diseases]. / Immunokhimicheskie testy riska vospalitel'nykh zabolevanii.

Immunochemical measurements of the blood serum acute-phase proteins (APP)--C-reactive, pregnancy-related alpha 2-glycoprotein, lactoferrin, immunoglobulins A, M, and G, carried out in 153 healthy men and 46 children, has revealed that an elevated level of at least one, and, more so, of two or three APP evidences the presence of an inflammatory process in the examinee. In a number of cases enhanced APP production correlated with a marked reduction of IgA and IgG concentrations. Measurements of APP may be employed as available laboratory screening markers of nonspecific latent inflammation in adults and children.

[Clinical significance of the immunochemical study of serum and tissue proteins of the sputum in pulmonary pathology]. / Klinicheskoe znachenie immunokhimicheskogo issledovaniia syvorotochnykh i tkanevykh belkov v mokrote pri legochnoi patologii.

The content of normal serum proteins, acute phase (C-reactive protein, pregnancy-associated alpha 2-glycoprotein) and tissue proteins (ferritin, nonspecific tissue esterase) was studied in the sputum of 256 patients with different pulmonary pathology, over time using immunochemical methods. Protein elimination with the sputum was shown to depend upon the nature and gravity of bronchitis and pulmonary destruction. Analysis of the qualitative composition of the sputum proteins and their content can be used in pulmonology for differential diagnosis and assessment of a course of pulmonary diseases.

[Physicochemical characteristics of a specific beta 1-globulin in the blood serum of pregnant women]. / Fiziko-khimicheskaia kharakteristika spetsificheskogo beta 1-globulina syvorotki krovi beremennykh zhenshchin.

Some physico-chemical properties of beta1-globulin (BGG) (the protein specific for pregnancy) were estimated. BGG was shown to be glycoprotein, possessing the antigenic individuality. The heterogeneity of the protein studied was observed in salt fractionation, polyacrylamide gel electrophoresis, ion exchange chromatography and isoelectrofocusing; this demonstrates the existence of various BGG fractions.