Causes of Multiple Organ Dysfunction During Cardiosurgical Operations under Extracorporeal Circulation

Objective: to reveal possible causes of postoperative multiple organ dysfunction syndrome (MODS) in patients after surgery under extracorporeal circulation (EC), by measuring the level and balance of pro- and anti-inflammatory cytokines. Subjects and methods. The investigation enrolled 162 patients who had undergone operations on the heart and thoracic aorta. The levels of interleukins (IL)-6, IL-8, and IL-10 were determined by ELISA. Results. At surgery under EC, MODS was encountered in 5.7%, mortality was 55.6%. The principal causes of MODS were prolonged EC concurrent with bleeding (23%), massive hemorrhage (16%), perioperative myocardial infarction and cardiogenic shock (15%), prolonged EC (12%), acute lung injury (12%), disseminated intravascular coagulation (10%), allergic and anaphylactic reactions (9%), and intravascular hemolysis (6%). The levels of pro- and anti-inflammatory cytokines were substantially increased in all the patients after surgery under EC irrespective of the presence of MODS in the postoperative period. The patients with MODS displayed pro- and anti-inflammatory cytokine imbalance due to a preponderance of the proinflammatory activity of a systemic response. During massive hemorrhage (more than 20 ml/kg), the patients with MODS exhibited a reduction in the two pools of cytokines. In the absence of MODS, there was a parallel increase in both pro- and anti-inflammatory cytokines. The magnitude of a change in the level of cytokines is related to the volume of blood loss. During prolonged EC (more than 170 min), the patients with MODS had a higher pro- and anti-inflammatory cytokine ratio due to the elevated levels of both pools, but the elevation of anti-inflammatory cytokines was more pronounced. In the patients without MODS, the values of both groups of interleukins were sigmficantly unchanged with longer duration of EC. Key words: multiple organ dysfunction syndrome, systemic inflammatory reaction, interleukins 6, 8, 10, extracorporeal circulation, operations on the heart and thoracic aorta

Negative magneto-resistance of electron gas in a quantum well with parabolic potential

We have studied the electrical conductivity of the electron gas in parallel electric and magnetic fields directed along the plane of a parabolic quantum well (across the profile of the potential). We found a general expression for the electrical conductivity applicable for any magnitudes of the magnetic field and the degree of degeneration of the electron gas. A new mechanism of generation of the negative magnetoresistance has been revealed. It has been shown that in a parabolic quantum well with a non-degenerated electron gas the negative magnetoresistance results from spin splitting of the levels of the size quantization.Comment: 15 pages, 3 figure

Negative Longitudinal Magneto-Thermoelectric Power in a Semiconductor Parabolic Quantum Well

We present a theoretical study of the electronic thermoelectric power of a semiconductor parabolic quantum well in a magnetic field. The case of a longitudinal magnetic field, with respect to the temperature gradient, has been considered. The calculations were carried out taking into account spin-splitting of the dimensionally quantized electronic energy levels. It has been shown that in the region of strong confinement the thermoelectric power decreases with increasing magnetic field, which is related to the downward shift of the lower Zeeman-split spin subband.Comment: 11 pages, 1 figire, MISHT-2007 The First International Conference on Material and Information Sciences in High Technologies, Baku, Azerbaijan, September 26-29, 200

Причины возникновения полиорганной недостаточности при кардиохирургических операциях в условиях искусственного кровообращения

Objective: to reveal possible causes of postoperative multiple organ dysfunction syndrome (MODS) in patients after surgery under extracorporeal circulation (EC), by measuring the level and balance of pro- and anti-inflammatory cytokines. Subjects and methods. The investigation enrolled 162 patients who had undergone operations on the heart and thoracic aorta. The levels of interleukins (IL)-6, IL-8, and IL-10 were determined by ELISA. Results. At surgery under EC, MODS was encountered in 5.7%, mortality was 55.6%. The principal causes of MODS were prolonged EC concurrent with bleeding (23%), massive hemorrhage (16%), perioperative myocardial infarction and cardiogenic shock (15%), prolonged EC (12%), acute lung injury (12%), disseminated intravascular coagulation (10%), allergic and anaphylactic reactions (9%), and intravascular hemolysis (6%). The levels of pro- and anti-inflammatory cytokines were substantially increased in all the patients after surgery under EC irrespective of the presence of MODS in the postoperative period. The patients with MODS displayed pro- and anti-inflammatory cytokine imbalance due to a preponderance of the proinflammatory activity of a systemic response. During massive hemorrhage (more than 20 ml/kg), the patients with MODS exhibited a reduction in the two pools of cytokines. In the absence of MODS, there was a parallel increase in both pro- and anti-inflammatory cytokines. The magnitude of a change in the level of cytokines is related to the volume of blood loss. During prolonged EC (more than 170 min), the patients with MODS had a higher pro- and anti-inflammatory cytokine ratio due to the elevated levels of both pools, but the elevation of anti-inflammatory cytokines was more pronounced. In the patients without MODS, the values of both groups of interleukins were sigmficantly unchanged with longer duration of EC. Key words: multiple organ dysfunction syndrome, systemic inflammatory reaction, interleukins 6, 8, 10, extracorporeal circulation, operations on the heart and thoracic aorta.Цель исследования . Выявление возможных причин возникновения полиорганной недостаточности (ПОН) в послеоперационном периоде у больных после операций в условиях ИК, на основе изучения уровня и баланса про- и проти-воспалительных цитокинов. Материалы и методы. Исследование базируется на обследовании 162 пациентов, которым были выполнены операции на сердце и грудном отделе аорты. Исследовались уровни интерлейкинов: ИЛ — 6, 8, 10 однофазным иммуноферментным анализом по методу ELISA. Результаты. ПОН при операциях в условиях ИК встречается в 5,7%, при этом летальность составляет 55,6%. Основными причинами возникновения ПОН являются: длительный ИК в сочетании с кровотечением — 23%, массивное кровотечение — 16%, периоперационный инфаркт миокарда и кардиогенный шок — 15%, длительный ИК — 12%, синдром острого повреждения легких — 12%, ДВС-синд-ром — 10%, аллергические и анафилактические реакции — 9%, внутрисосудистый гемолиз — 6%. Уровень про- и противовоспалительных цитокинов значительно повышается у всех пациентов после операций в условиях ИК, вне зависимости от наличия ПОН в послеоперационном периоде. У больных с ПОН отмечается дисбаланс между про- и противовоспалительными пулами цитокинов, за счет преобладания активности провоспалительного звена системного ответа. При массивной кровопотере (более 20 мл/кг), у больных с ПОН, организм реагирует снижением обеих пулов цитокинов, При отсутствии ПОН отмечено параллельное увеличение как про- так и противовоспалительных цитоки-нов. Степень изменения уровня цитокинов зависит от объема кровопотери. При длительном ИК (более 170 мин), у пациентов с ПОН, индекс соотношения про- и противовоспалительных цитокинов увеличивается, за счет повышения уровня цитокинов обеих пулов. Увеличение противовоспалительных цитокинов выражено при этом сильнее. У больных без ПОН значения обеих групп интерлейкинов достоверно не изменяется при увеличении длительности ИК. Ключевые слова: синдром полиорганной недостаточности, системная воспалительная реакция, интерлейкины 6, 8, 10, искусственное кровообращение, операции на сердце и грудном отделе аорты

Analysis of NMR Spectra of Submicro-Containers with Biocide DCOIT

Nowadays, the search for and development of new forms of materials with biocides is an actual problem of the modern science of nanosized materials due to the problem of microbiological contamination, which can be solved by using nanocontainers carrying biocides. Depending on the morphology of the nanocontainers and the filled active agents, it is possible to create coatings with specially designed self-healing functionality or multifunctional properties. The purpose of this work was to produce submicro-containers (SMCs) with a shell of SiO₂ nanoparticles and a core of polymerized 3-(trimethoxysilyl) propyl methacrylate filled with 5-dichloro-2-n-octyl-4-isothiazolin-3-one (DCOIT) in an oil in water (O/W) emulsion. The chemical nature of the individual components of the system and nano-capsules were investigated using NMR spectroscopy. The size and zeta potential of the SMCs were measured by a dynamic light scattering method (d = 170–180 nm, polydispersity index PDI = 0.125 and zeta-potential = 55 mV), the morphology of their outer surface was determined using SEM. The results of NMR analysis showed that during the addition of the biocide into the SMCs, its chemical structure is retained, as is its activity. Minor changes in the chemical shifts of the ¹H NMR spectra of the SMCs with DCOIT, as well as of the biocide itself, confirm the inclusion of DCOIT inside the SMCs

Влияние плазмафереза на динамику цитокинов после операций на сердце и магистральных сосудах

Objective. To assess the impact of plasmapheresis on the time course of changes in pro- and anti-inflammatory interleukins and the results of treatment in patients after complicated operations on the heart and great vessels.Material and methods. 44 patients were examined. In 33 patients, the intra- and postoperative period was complicated by a prolonged extracorporeal circulation (EC), massive blood loss, acute hemolysis, the development of disseminated intravascular coagulation. The above complications gave grounds to perform plasmapheresis (PA) in different postoperative periods. The patients were equally divided into 4 groups (each containing 11 patients): 1) patients with multiple organ dysfunction (MOD), in whom PA was conducted within 2—6 hours after surgery; 2) those without MOD, in whom PA was also performed within 2—6 hours after surgery; 3) those with MOD in whom PA was made 16-20 hours after surgery; 4) a control group (receiving no PA), the early postoperative period was normal. Interleukins (IL) 6, 8, and 10 and the oxygenation index (OI) after surgery and in the first 24 postoperative hours, the duration of EC, the volume of blood loss, and a postoperative clinical period were studied.Results. The duration of EC was highest in Group 1 patients and 37 and 130% greater in Groups 2 and 3, respectively. The elevated levels of IL-6 were noted in all the patients. In the early post-PA periods, the content of IL-6 was decreased by 30% in Groups 1 and 2 patients. In Group 3, the level of IL-6 remained unchanged within the first 24 hours. The postoperative concentration of IL-8 was increased in all the patients. There were no changes in the content of IL-8 after surgery and within the first 12 hours. In Group 3 patients, the level of IL-8 within the first 24 hours was 5 times higher than that observed just after surgery. In patients with developed MOD, a correlation was found between IL-8 and OI postoperatively and within the first 24 hours after surgery. The level of IL-10 was higher in patients without developed MOD. Groups 1, 2, and 4 showed a significant decrease in the concentration of IL-10 by the first 24 postoperative hours as compared with the baseline values. The content of LI-10 remained unchanged in Group 3 patients.Conclusion. A systemic inflammatory response accompanied by the elevated levels of pro- and anti-inflammatory IL develops in all the patients undergoing surgery under EC. The subsequent development of MOD is determined by the imbalance between the alternative pools of cytokines. The correlation between the levels of IL-8 and OI suggests that this cytokine plays an important role in the development of postoperative respiratory failure. Indications for the use of PA are high risk factors of MOD (blood loss, more than 26 ml/kg; the duration of EC, more than 165 min). PA performed in early postoperative periods prevents the development of MOD and reduces mortality rates up to 2%. With subsequent progression of MOD, the mortality rates are 28 and 42% with early and late PA, respectively.Цель исследования. Изучить влияние плазмафереза на динамику про- и противовоспалительных интерлейкинов и результаты лечения больных после осложненных операций на сердце и магистральных сосудах.Материалы и методы. Обследовано 44 пациента. У 33 пациентов интра- и послеоперационный период осложнился длительным искусственным кровообращением, массивной кровопотерей, острым гемолизом, развитием ДВС — синдрома. Перечисленные осложнения послужили основанием для проведения плазмафереза (ПА) в различные сроки послеоперационного периода. Группы пациентов (по 11 больных): 1-я — со СПОН, ПА выполнялся в течение 2 — 6 часов после операции (п/о); 2-я — без СПОН, ПА проводился так же в течение 2 — 6 часов п/о; 3-я — со СПОН, ПА осуществлялся через 16 — 20 часов п/о; 4-я — контрольная (без ПА), ранний п/о период протекал без особенностей. Исследовали интерлейкины (ИЛ) 6, 8 и 10, индекс ок-сигенации (ИО) после операции (п/о) и в первые послеоперационные (1п/о) сутки, длительность ИК, объемом кровопотери и клиническим течением п/о периода.Результаты. Длительность ИК была наибольшей у пациентов 1 группы и превышала этот показатель у больных 2 и 3 групп на 37%, а контрольной — на 130%. Увеличение ИЛ 6 отмечается у всех пациентов. После проведения ПА в ранние сроки ИЛ 6 у пациентов 1 и 2 групп уменьшился на 30 %. В 3 группе содержание ИЛ 6 в 1 п/о сутки не изменяется. ИЛ 8 был повышен после операции у всех пациентов. В 1 и 2 группе изменений ИЛ 8 при сравнении значении п/о и в 1 п/о сутки не найдено. Содержание ИЛ 8 в 1 п/о сутки у пациентов 3 группы превышало п/о уровень в 5 раз. Выявлена корреляция между уровнем ИЛ 8 и ИО п/о и в 1 п/о сутки у пациентов с развитием СПОН. Уровень ИЛ 10 был выше у пациентов без развития СПОН. К 1 п/о суткам в 1, 2 и 4 группе выявлено достоверное уменьшение концентрации ИЛ 10 по сравнению с п/о уровнем. У больных 3 группы содержание ИЛ 10 не изменяется.Заключение. Системный воспалительный ответ, сопровождающийся увеличением про- и противовоспалительных ИЛ, развивается у всех пациентов, перенесших операцию в условиях ИК. Последующее развитие СПОН определяется выраженностью дисбаланса между альтернативными пулами цитокинов. Корреляция между ИЛ 8 и ИО свидетельствует о важной роли этого цитокина в развитии послеоперационной дыхательной недостаточности. Показаниями к проведению ПА являются факторы высокого риска развития СПОН (кровопотеря более 26 мл/кг, длительный период ИК — более 165 мин). Проведение ПА в ранние сроки препятствует развитию СПОН и снижает летальность до 2%. При последующем прогрес-сировании СПОН летальность при раннем ПА составляет 28%, при отсроченном — 42%

Modulation of endogenous antioxidant defense and the progression of kidney disease in multi-heritage groups of patients with type 2 diabetes: PRospective EValuation of Early Nephropathy and its Treatment (PREVENT).

BACKGROUND: Diabetes is the western world's leading cause of end-stage renal disease. Glucose-dependent, oxidative stress is linked to the development of renal inflammation and sclerosis, which, in animal models of diabetes, can be prevented by anti-oxidative treatment. Patients of non-Caucasian heritage have low activity of the selenoprotein, antioxidant enzyme, glutathione peroxidase (GPx) and its co-factor vitamin E, which may be linked to their increased propensity to developing end-stage renal disease. RESEARCH DESIGN AND METHODS: We have designed a double-blind, randomized, placebo controlled study with selenium and/or vitamin E versus placebo as the interventions for patients with type 2 diabetes and chronic kidney disease (CKD) stages 1-3. A 2 × 2 factorial design will allow a balanced representation of the heritage groups exposed to each intervention. The primary biochemical outcome is change in GPx activity, and clinical outcome measure is the actual, rate of-and/or percentage change in estimated glomerular filtration rate (eGFR) from baseline. Analysis will be with a marginal model for longitudinal data using Generalized Estimating Equations corrected for measures of baseline serum antioxidant enzyme activities (GPx, superoxide dismutase and catalase), micronutrient levels (vitamins E and C), measures of inflammation (interleukin 6, c-reactive protein and monocyte chemoattractant protein-1) and markers of oxidative damage (plasma 8-isoprostaglandin F2α and urinary 8-hydroxydeoxyguanosine). EXPECTED RESULTS: The study will assess the relationship between GPx activity, oxidative stress, inflammation and eGFR. It will test the null hypothesis that antioxidant therapy does not influence the activity of GPx or other antioxidant enzymes and/or alter the rate of change in eGFR in these patient groups. CONCLUSIONS: Outcome data on the effect of antioxidants in human diabetic renal disease is limited. Previous post hoc analyses have not shown a beneficial effect of vitamin E on renal function. A recent trial of a pharmaceutical antioxidant agent, improved eGFR, but in patients with advanced diabetes-related chronic kidney disease its use was associated with an increased incidence of cardiovascular events. We will explore whether the nutritional antioxidants, vitamin E and selenium alone, or in combination in patients at high risk of renal disease progression, forestalls a reduction in eGFR. The study will describe whether endogenous antioxidant enzyme defenses can be safely modified by this intervention and how this is associated with changes in markers of oxidative stress. Trial registration ISRCTN 97358113. Registered 21st September 2009

Ethnic minority disparities in progression and mortality of pre-dialysis chronic kidney disease : a systematic scoping review

Background: There are a growing number of studies on ethnic differences in progression and mortality for pre-dialysis chronic kidney disease (CKD), but this literature has yet to be synthesised, particularly for studies on mortality. Methods: This scoping review synthesized existing literature on ethnic differences in progression and mortality for adults with pre-dialysis CKD, explored factors contributing to these differences, and identified gaps in the literature. A comprehensive search strategy using search terms for ethnicity and CKD was taken to identify potentially relevant studies. Nine databases were searched from 1992 to June 2017, with an updated search in February 2020. Results: 8059 articles were identified and screened. Fifty-five studies (2 systematic review, 7 non-systematic reviews, and 46 individual studies) were included in this review. Most were US studies and compared African-American/Afro-Caribbean and Caucasian populations, and fewer studies assessed outcomes for Hispanics and Asians. Most studies reported higher risk of CKD progression in Afro-Caribbean/African-Americans, Hispanics, and Asians, lower risk of mortality for Asians, and mixed findings on risk of mortality for Afro-Caribbean/African-Americans and Hispanics, compared to Caucasians. Biological factors such as hypertension, diabetes, and cardiovascular disease contributed to increased risk of progression for ethnic minorities but did not increase risk of mortality in these groups. Conclusions: Higher rates of renal replacement therapy among ethnic minorities may be partly due to increased risk of progression and reduced mortality in these groups. The review identifies gaps in the literature and highlights a need for a more structured approach by researchers that would allow higher confidence in single studies and better harmonization of data across studies to advance our understanding of CKD progression and mortality