During epidemics, the usual statistical approaches will not allow determining the readiness of the public health system to take urgent measures to counteract the increase in morbidity, spread and mortality of the population. The quality of the medical, socio-economic and managerial decisions at all levels will depend on the accuracy of statistical data and the possibility of creating adequate prognostic models. However, there are still problems with the identification of COVID-19 cases and the diagnostic accuracy of the methods used. Complex analytical efforts require in order to determine the COVID-19 impact on the health status and case fatality rate/mortality rate.

Pulmonary embolism is a life-threatening condition, which can result in respiratory insufficiency and death. Blood clots occluding branches of the pulmonary artery (PA) are traditionally considered to originate from thrombi in deep veins (usually in legs). However, growing evidence suggests that occlusion of the vessels in the lungs can develop without preceding deep vein thrombosis (DVT). In this work, we used an inferior vena cava (IVC) complete ligation model of DVT in Wistar rats to explore the possibility and mechanisms of PA thrombosis under the conditions where all routes of thrombotic mass migration from peripheral veins are blocked. We demonstrate that rats both with normal and reduced neutrophil counts developed thrombi in the IVC, although, neutropenia caused a substantial decrease in thrombus size and a shift from fresh fibrin toward mature fibrin and connective tissue inside the thrombus. Massive fibrin deposition was found in the PA branches in the majority of DVT rats with normal neutrophil counts, but in none of the neutropenic animals. Neutrophil ablation also abolished macroscopic signs of lung damage. Altogether, the results demonstrate that thrombi in the lung vasculature can form in situ by mechanisms that require local neutrophil recruitment taking place in the DVT setting.

Doxorubicin, which is widely used to treat a broad spectrum of malignancies, has pronounced dose-dependent side effects leading to chronic heart failure development. Nicotinamide riboside (NR) is one of the promising candidates for leveling the cardiotoxic effect. In the present work, we performed a comparative study of the cardioprotective and therapeutic actions of various intravenous NR administration modes in chronic doxorubicin-induced cardiomyopathy in Wistar rats. The study used 60 mature male SPF Wistar rats. The animals were randomized into four groups (a control group and three experimental groups) which determined the doxorubicin (intraperitoneally) and NR (intravenous) doses as well as the specific modes of NR administration (combined, preventive). We demonstrated the protective effect of NR on the cardiovascular system both with combined and preventive intravenous drug administration, which was reflected in a fibrous tissue formation decrease, reduced fractional-shortening decrease, and better antioxidant system performance. At the same time, it is important to note that the preventive administration of NR had a more significant protective effect on the animal organism as a whole. This was confirmed by better physical activity parameters and vascular bed conditions. Thus, the data obtained during the study can be used for further investigation into chronic doxorubicin-induced cardiomyopathy prevention and treatment approaches.

Objective. To evaluate the effect of NO added to the sweep gas of the oxygenator during cardiopulmonary bypass (CPB) on the liver and kidneys in pigs. Methods. An experiment was carried out on 10 pigs undergoing cardiac surgery using CPB. NO was added to the sweep gas of the oxygenator at a concentration of 100 ppm for the animals in the experimental group (CPB-NO, n = 5). Animals in the control group (CPB-contr, n = 5) did not receive NO in the sweep gas of the oxygenator. The CPB lasted 4 h, followed by postoperative monitoring for 12 h. To assess the injury to the liver and kidneys, the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), bilirubin, creatinine, and neutrophil gelatinase-associated lipocalin (NGAL) were determined initially, at weaning from the CPB, and 6 and 12 h after weaning from the CPB. The glomerular filtration rate (GFR) was evaluated initially, at weaning from the CPB, and 6 and 12 h after weaning from the CPB. A pathomorphological study of the liver and kidneys was performed using semiquantitative morphometry. Results. The long four-hour period of CPB deliberately used in our experiment caused liver and kidney injury. In the CPB-contr group, an increase in the ALT concentration was found: 43 (34; 44) U/L at baseline to 82 (53; 99) U/L 12 h after CPB, p < 0.05. The AST concentration in the CPB-contr group increased from 25 (17; 26) U/L at baseline to 269 (164; 376) U/L 12 h after CPB, p < 0.05. We found no significant increase in the ALT and AST concentrations in the CPB-NO group. There were no significant differences in ALT and AST concentrations between the CPB-NO and CPB-contr groups at all the study time-points. In the CPB-contr group, an increase in the creatinine level was found from 131 (129; 133) µmol/L at baseline to 273 (241; 306) µmol/L 12 h after CPB, p < 0.05. We found no significant increase in creatinine level in the CPB-NO group. Creatinine levels in the CPB-NO group were significantly lower than in the CPB-contr group 12 h after weaning from CPB: 183 (168; 196) vs. 273 (241; 306) µmol/L; p = 0.008. The GFR in the CPB-NO group was significantly higher than in the CPB-contr group 6 h after weaning from CPB: 78.9 (77.8; 82.3) vs. 67.9 (62.3; 69.2) mL/min; p = 0.016. GFR was significantly higher in the CPB-NO group than in the CPB-contr group 12 h after weaning from CPB: 67.7 (65.5; 68.0) vs. 50.3 (48.7; 54.9) mL/min; p = 0.032. We found no significant differences between the study groups in the level of NGAL. We found several differences between the groups in the pathomorphological study. Conclusions. NO added to the sweep gas of the oxygenator reduces creatinine levels and increases GFR during prolonged CPB injury. Further research is required.

Туберкулез занимает лидирующее положение среди вторичных инфекций в структуре смертности пациентов с ВИЧ. При этом морфологическая диагностика при сочетании таких заболеваний часто сопряжена со значительными трудностями ввиду нетипичного течения туберкулеза на фоне иммуносупрессии. Цель исследования — оценка клинико-морфологических особенностей туберкулеза в сочетании с ВИЧ-инфекцией. Материал и методы. Проанализирован аутопсийный материал, полученный из Клинической инфекционной больницы им. С.П. Боткина (КИБ им. С.П. Боткина), за 2018 г. Детально изучено 8 образцов с использованием окрасок гематоксилином и эозином, карболовым фуксином по Цилю—Нильсену, аурамин-родамином (с последующей люминесцентной микроскопией), проведено иммуногистохимическое исследование. Результаты. По результатам 736 вскрытий за 2018 г. в КИБ им. С.П. Боткина смерть от ВИЧ-инфекции установлена в 357 случаях, в 86 (24%) из которых выявлено сочетание ВИЧ-инфекции и туберкулеза. Во всех наблюдениях определена крайне разнообразная и неоднородная картина, значительно отличающаяся от таковой при классическом гранулематозном воспалении при туберкулезе. При окраске по Цилю—Нильсену обнаружены единичные скопления кислотоустойчивых бактерий общим числом не более 1000 в препарате преимущественно палочковидной формы. При окраске аурамин-родамином выявлены очаговые скопления микобактерий общим числом от 1000 до 2000 в препарате преимущественно палочковидных, а также кокковидных. При ИГХ-исследовании найдены скопления микобактерий общим числом более 2000 в препарате, характеризовавшихся умеренным разнообразием форм: встречались палочковидные, кокковидные, гранулы, булавовидные и ветвящиеся. Во всех исследованных случаях микобактерии были расположены внеклеточно. Выводы. Туберкулез сохраняет важнейшее место в структуре причин смерти при ВИЧ-инфекции, составляя 24%. Прижизненная диагностика туберкулеза остается не вполне удовлетворительной. Чаще преобладает альтеративный компонент воспаления, хотя и без полной утраты способности к формированию гранулем. Одновременное сочетание различных морфологических форм туберкулеза делает крайне желательным уточнение и/или дополнение существующих классификаций. Ни один из использованных методов выявления микобактерий туберкулеза в тканях не позволил обнаружить внутриклеточную локализацию возбудителя. Большинство микобактерий имели типичную палочковидную морфологию.