Factors influencing the choice of the pole pitch of linear inductors of electrodynamic separators

Features of the choice of pole pitch of linear induction machines of electrodynamic separators are considered. As criteria for this choice, indicators are used: operability, energy efficiency, selectivity of separation

Pathogenetic and Prognostic Significance of Thrombocytopenia in Patients With Necrotizing Soft Tissue Infections

Necrotizing soft tissue infection (NSTI) is a severe surgical infection which can result in sepsis and septic shock when generalized.The aim of the study was to determine the frequency of thrombocytopenia in patients with generalized NSTI, the factors promoting its development, and its association with septic shock.Materials and Methods. We examined 129 patients with NSTI treated between 09.2015 and 12.2019 at St. George Hospital in St. Petersburg, Russia. Surgical treatment, hematological and biochemical examinations, and bacteriological analysis of blood and wound discharge were performed in each patient. The studied group included 22 patients with systemic inflammatory reaction syndrome, 63 patients with sepsis, and 44 patients with septic shock.Results. We found a decrease in platelet count in NSTI patients with septic shock as early as on the first day of the disease and its further decrease within the next 3 days, with the mean platelet volume (MPV) increasing during the same period and significantly exceeding that in patients with sepsis and systemic inflammatory response syndrome. In NSTI patients with thrombocytopenia on admission, we found a significant correlation between the platelet count and the percentage of segmented neutrophils (r=0.349; P<0.001; n=40). The maximum incidenсe of septic shock was observed in patients infected with Klebsiella pneumoniae (13 out of 19, 65%). These patients had the highest MPV but did not develop thrombocytopenia. Maximum frequency of thrombocytopenia and elevation of MPV and platelet distribution width (PDW) was found in patients with NSTI and underlying chronic viral hepatitis C. However, the relative frequency of septic shock in these patients was not increased.Conclusion. The development of septic shock in NSTI is associated with a specific platelet activation patter

Impact of transfusion of blood components on the recipient immune system

Transfusions of blood provide essential therapeutic measures in a number of pathological conditions. However, when carrying out blood component therapy, it is important to consider probability of post-transfusion complications. Most of them are immune-mediated side effects. The unfavorable consequences of blood transfusions can manifest at long-range time periods, and pathogenesis of these phenomena may be associated not only with the presence of alloantibodies. They may be caused by alloimmunization to HLA antigens, leukocyte factors, including cytokines, products of leukocyte degranulation, as well as storage-related erythrocyte damage («storage lesion»), immunomodulatory properties of extracellular vesicles or microparticles derived from blood components, and other factors. Despite significant number of publications on this issue, a lot of unresolved issues still remain, concerning transfusion-related effects of blood components on the immune system of recipients. The review article provides the results of current studies in this area. We present and discuss the results of current studies and the features of transfusion-mediated immunomodulation (TRIM) revealed over recent years, when transfusing different blood components. The role of plasma factors, microparticles, platelets and erythrocytes, HLA sensitization and microchimerism in the development of TRIM is highlighted, the data on occurrence and clinical features of TRIM in perioperative period are presented. A separate section of the review provides information about recent clinical studies, devoted to the issues of TRIM in different clinical cohorts, including newborns, patients with malignant neoplasms, immunocompromised patients after heart and vascular surgery. The data on TRIM incidence in the patients with exhausted immune system due to previous disease or treatment, severe comorbidity, extensive surgical thoracic/abdominal intervention and artificial circulation are also in scope. As based on the studies performed, the role of distinct measures, e.g., washing of erythrocyte concentrates, leukodepletion, and gamma irradiation are discussed in view of potential TRIM prevention. The results of published research do not allow us to draw definite conclusions about the effects of blood component transfusion on the immune system of recipients with respect to differences between the studied groups of patients, characteristics of the studied disorders and clinical situations, diversity of hemocomponents, as well as varying standards of transfusion therapy adopted in different countries. However, the systematic literature review may provide some guidance in transfusion-mediated immune modulation

Патогенетическое и прогностическое значение тромбоцитопении у пациентов с некротизирующими инфекциями мягких тканей

Necrotizing soft tissue infection (NSTI) is a severe surgical infection which can result in sepsis and septic shock when generalized.The aim of the study was to determine the frequency of thrombocytopenia in patients with generalized NSTI, the factors promoting its development, and its association with septic shock.Materials and Methods. We examined 129 patients with NSTI treated between 09.2015 and 12.2019 at St. George Hospital in St. Petersburg, Russia. Surgical treatment, hematological and biochemical examinations, and bacteriological analysis of blood and wound discharge were performed in each patient. The studied group included 22 patients with systemic inflammatory reaction syndrome, 63 patients with sepsis, and 44 patients with septic shock.Results. We found a decrease in platelet count in NSTI patients with septic shock as early as on the first day of the disease and its further decrease within the next 3 days, with the mean platelet volume (MPV) increasing during the same period and significantly exceeding that in patients with sepsis and systemic inflammatory response syndrome. In NSTI patients with thrombocytopenia on admission, we found a significant correlation between the platelet count and the percentage of segmented neutrophils (r=0.349; P<0.001; n=40). The maximum incidenсe of septic shock was observed in patients infected with Klebsiella pneumoniae (13 out of 19, 65%). These patients had the highest MPV but did not develop thrombocytopenia. Maximum frequency of thrombocytopenia and elevation of MPV and platelet distribution width (PDW) was found in patients with NSTI and underlying chronic viral hepatitis C. However, the relative frequency of septic shock in these patients was not increased.Conclusion. The development of septic shock in NSTI is associated with a specific platelet activation patternНекротизирующая инфекция мягких тканей (НИМТ) — тяжелая хирургическая инфекция, при генерализации которой часто развивается сепсис и септический шок.Цель исследования — определить частоту тромбоцитопении у больных с генерализованными формами НИМТ, факторы, способствующие ее развитию и связь с развитием септического шока.Материал и методы. Обследовали 129 больных c НИМТ, лечившихся с 09.2015 по 12.2019 гг. в больнице Св. Великомученика Георгия Санкт-Петербурга. Всем пациентам провели хирургическое лечение, лабораторное гематологическое и биохимическое обследование и бактериологическое исследование крови и отделяемого из раны. Всего больных с синдромом системной воспалительной реакции было 22, с сепсисом — 63, септическим шоком — 44 человека.Результаты. Выявили снижение количества тромбоцитов у больных НИМТ с септическим шоком уже в первые сутки заболевания и дальнейшее его снижение в течение 3-х дней, причем средний объем тромбоцитов (MPV) в эти же сроки возрастал и существенно превосходил таковой у больных с сепсисом и синдромом системной воспалительной реакции. У больных НИМТ, имевших при поступлении тромбоцитопению, выявили статистически значимую корреляцию количества тромбоцитов с долей сегментоядерных нейтрофилов (r=0,349; р<0,001; n=40). Максимальную частоту септического шока отметили у больных, инфицированных Klebsiella pneumoniaе (13 из 19, 65%). У этих больных тромбоциты имели наибольший MPV, однако тромбоцитопения не развивалась. Максимальную частоту тромбоцитопении, увеличение MPV и анизоцитоз (относительную ширину распределения тромбоцитов по объему — PDW) выявили у больных с развитием НИМТ на фоне хронического вирусного гепатита С. Однако, сравнительная частота развития септического шока у этих больных не была повышена.Заключение. Развитие септического шока при НИМТ обусловлено определенным типом активации тромбоцито

RELATIONSHIP BETWEEN SINGLE NUCLEOTIDE POLYMORPHISMS IN CYTOKINE GENES AND CLINICAL LABORATORY PARAMETERS IN PATIENTS WITH MULTIPLE MYELOMA

Multiple myeloma is the most common form of paraproteinemic hemoblastosis, which is characterized by variability of clinical manifestations, forms, and variants. Limited efficiency of antitumor immune protection in the patient plays an important role in progression of this disease. Survival of myeloma cells is promoted by some growth factors, including a number of interleukins. Cytokines and chemokines are secreted in response to intercellular interactions and stimulate tumor growth, inhibition of osteoblasts and increase of the osteoclastic activity. Cytokine genes show a significant allelic polymorphism. A single gene may exhibit numerous polymorphic sites located in exons, introns and promoter regulatory areas. Single nucleotide substitutions in the promoter region of cytokine genes are known to have a huge impact upon secretion and biological activity of these factors. Therefore, a study of allelic gene variants determining the levels of cytokine production will allow of establishing new immunogenetic factors associated with a high risk of disease development, including multiple myeloma. We have studied single nucleotide polymorphism in cytokine genes (IL-1α -889 TT, IL-1β +3962 TT, IL-6 -174 GG, and IL-6 nt565 GG), and clinical laboratory parameters (serum levels of albumin, β2-microglobulin, and hemoglobin) determining severity grade of multiple myeloma in 80 patients living in the North-Western region of Russia. It was found that the presence of certain cytokine gene variants, i.e., IL-1α -889 TT, IL-1β +3962 TT, IL-6 -174 GG, IL-6 nt565 GG or IL-1α -889 TT, IL- 1β +3962 TT or IL-6 -174 GG, IL-6 nt565 GG was associated with low albumin levels (< 3.5 g/DL), and high levels of β2-microglobulin (> 5.5 mg/l). A combination of all the four negative variants in homozygous state (IL- 1α TT -889, IL-1β +3962 TT, IL-6 -174 GG and IL-6 nt565 GG) increases the chance of six-fold reduction of albumin levels (p < 0.05); combinations of homozygous IL-1α TT -889, IL-1β +3962 TT, IL-6-174 GG. and IL-6 nt565 GG are associated with increased chance of high-level β2-microglobulin (> 5.5 mg/l) by more than two times. This data allow to consider IL-1α -889 TT, IL-1β +3962 TT, IL-6 -174 GG, and IL-6 nt565 GG genotypes additional negative immunogenetic factors in the prognosis of multiple myeloma

INFLUENCE OF HLA-DRB1* ALLELIC SETS ON THE DEVELOPMENT OF TUBERCULOSIS IN CHILDREN

According to the WHO data, tuberculosis still represents a serious public health problem worldwide. Deterioration of socio-economic conditions in the population complicates epidemic situation for tuberculosis inRussia, thus leading to increase in acute progressive and complicated forms of tuberculosis in children and, consequently, to worsening structure of its clinical forms. Objectives: to determine associations between certain HLA-DRB1 alleles and risk of tuberculosis development in children. We examined 188 children aged from 3 to 14 years with various manifestations of tuberculous infection. Along with thorough examination of the patients, including multi-spiral CT scans of chest, we undertook genotyping of HLA-DRB1 alleles. Activity of tuberculous infection was determined by a set of immunological tests, i.e., tuberculin skin test, DIASKINTEST® (recombinant allergen of tuberculosis DIASKINTEST®). X ray diagnostics was performed with multi-spiral «Aquilion-32» computed tomograph (Toshiba), according to standard procedures. Molecular genetic typing of HLA-DRB1 alleles was performed by polymerase chain reaction (PCR-SSP), using standard commercial kits PROTRANS Ceclerplate System Protrans HLA-DRB1*. The children were divided into two groups: I group, 90 healthy children, II group, 98 children with tuberculosis. A comparisons group consisted of healthy donors (n = 346). Statistical processing of genetic material included evauation and analysis of the following parameters: frequency distribution of the antigen (F), χ2 criterion for significance (chi-square), the relative risk ratio (RR), etiologic fraction (EF), preventive fraction (PF). Children of the II group had significantly higher *04 allele HLADRB1*, as compared with control group (36.7% vs. 21.1%, χ2 = 10.08; р < 0.01). This finding may suppose a predisposal of these allele carriers to development of tuberculosis. At the same time, the rates of *07 (14.3% vs. 27.5%, χ2 = 7.15, р < 0.01) and *15 (18.4% vs. 28.3%, χ2 = 3.92; р < 0.01) HLA-DRB1* alleles were significantly lower, thus suggesting a protective effect of this allele. *04 allele seems to be a predisposing factor, whereas *07 and *15 alleles are protective for development of tuberculosis in children

Comparative analysis of immunogenetic characteristics of potential hematopoietic stem cell donors from the registries of two Russian megapolises

Efficacy of search for the unrelated compatible transplant donors depends on a number of factors. Of most importance are the standards of primary HLA typing, and the immunogenetic diversity of the donor pool. Timely donor selection guarantees the optimal timing for stem cell transplantation. This factor exerts positive influence upon the transplantation outcomes. In 2019, The Bone Marrow Donors Registry at the Russian Research Institute of Haematology and Transfusiology has implemented HLA-typing for HLA-A, HLA-B, HLA-C, HLA-DRB1, HLA-DQB1 genes as a standard for primary immunogenetic examination, in order to reduce the donor search period. The aim of our study was to evaluate the HLA typing results for potential stem cell donors at our Registry as compared with immunogenetic profile of donors at the Registries arranged in two Russian megapolises. All currently known groups of HLA-C, HLA-DRB1, HLA-DQB1 gene alleles, 19 of 21 open groups of HLA-A gene alleles, 34 of 36 known groups of HLA-B gene alleles were screened in the donors from our Registry. The most common HLA alleles groups were as follows: A*02 (0.2957), A*03 (0.1432), A*01 (0.1155), A*24 (0.1128); B*07 (0.1282), B*35 (0.1084), B*44 (0.0921), B*18 (0.0745); C*07 (0.2738), C*04 (0.1361), C*12 (0.1202), C*03 (0.1134), C*06 (0.1127); DRB1*15 (0.1445), DRB1*07 (0.1420), DRB1*13 (0.1271), DRB1*01 (0.1269), DRB1*11 (0.1216); DQB1*03 (0.3517), DQB1*06 (0.2269). A total of 1702 HLA-A*-B*-C*-DRB1*-DQB1*-haplotypes were revealed in our donor pool. The frequency of nine HLA-haplotypes exceeded 0.01: A*01-B*08-C*07-DRB1*03-DQB1*02 (0.0366), A*03-B*07-C*07-DRB1*15-DQB1*06 (0.0269), A*03-B*35-C*04-DRB1*01-DQB1*05 (0.0238), A*02-B*13-C*06-DRB1*07-DQB1*02 (0.0204), A*02-B*07-C*07-DRB1*15-DQB1*06 (0.0184), A*25-B*18-C*12-DRB1*15-DQB1*06 (0.0127), A*02-B*18-C*07-DRB1*11-DQB1*03 (0.0126), A*02-B*15-C*03-DRB1*04-DQB1*03 (0.0123), A*02-B*41-C*17-DRB1*13-DQB1*03 (0.0109). We carried out a comparative analysis of the HLA-haplotypes distribution for the donors of three Russian registers: Russian Research Institute of Haematology and Transfusiology (St. Petersburg); First St. Petersburg State I. Pavlov Medical University (St. Petersburg); National Medical Research Center for Hematology (Moscow). The six most common HLA-haplotypes among the donors from three Russian registers had the same rank positions and frequencies. The differences of some less common HLA-haplotypes distribution were determined. The results of our study indicate the immunogenetic diversity of the donor pool the Registry of Russian Research Institute of Haematology and Transfusiology. This fact, along with usage of international standards for primary immunogenetic examination is a prerequisite for effective donor search for the patients requiring stem cell transplantation

Analysis of the Dynamics of Tick-Borne Encephalitis Incidence and the Number of People who Appealed to Medical Organizations about Tick Bites in the European North of Russia

In recent decades, a significant increase in the incidence of tick-borne viral encephalitis (TBVE) and the number of people attacked by ticks has been recorded in the European North of Russia.The aim of the study was to analyze the dynamics of the TBVE incidence and the number of people who appealed to medical organizations regarding tick bites in the European North of Russia.Materials and methods. We used the Form No. 2 “Information on infectious and parasitic diseases”, the results of operational seasonal monitoring of TBVE, presented by the Rospotrebnadzor Administrations of the respective territories for our study. Statistical data processing was performed using the Microsoft Excel program. Display of the results on the map was carried out in the geographic information system ESRI ArcMap.Results and discussion. Combined analysis of the data on the number of cases and TBVE incidence, the number of people who appealed to medical organizations about tick bites and the number of people seeking advice about tick bites per 100 thousand population for the Arkhangelsk Region, the Republics of Karelia and Komi and their municipal districts has been performed. The mean values and gradients of the number of cases, incidence (2010–2020), the number of people who appealed to medical organizations regarding tick bites, and the number of people seeking treatment for tick bites per 100 000 population (2002–2020) have been calculated; maps of average values and gradients constructed. The incidence and the number of cases remain at the high level, exceeding the national average, but have been declining in the last decade. The number of people who appealed to medical organizations and the appealability of the population about tick bites per 100 000 of the population remain at a consistently high level and show no downward trend. The incidence and appealability of the population due to tick bites per 100 thousand of the population is spreading in a northerly direction, covering new territories in the Arctic zone. The main driving force behind the observed epidemic situation in the European North of Russia is the natural processes of climate change

Hybrid silicon nanostructures with conductive ligands and their microscopic conductivities

Silicon nanoparticles (SiNPs) functionalized with conjugated molecules promise a potential pathway to generate a new category of thermoelectric materials. While the thermoelectric performance of materials based on phenyl-acetylene capped SiNPs has been proven, their low conductivity is still a problem for their general application. A muon study of phenyl-acetylene capped SiNPs has been recently carried out using the HiFi spectrometer at the Rutherford Appleton Laboratory, measuring the ALC spectra as a function of temperature. The results show a reduction in the measured line width of the resonance above room temperature, suggesting an activated behaviour for this system. This study shows that the muon study could be a powerful method to investigate microscopic conductivity of hybrid thermoelectric materials