ИВЛИНДУЦИРОВАННЫЕ ПОВРЕЖДЕНИЯ ЛЕГКИХ (ЭКСПЕРИМЕНТАЛЬНОЕ ИССЛЕДОВАНИЕ)

Objective: to evaluate the impact of highfrequency jet ventilation (HFJV) and traditional positive endexpiratory pressure (PEEP) ventilation on blood oxygenation, gas exchange, and hemodynamics on an experimental model of acute lung injury.Material and methods. Thirty albino outbred laboratory male rats weighing 200—300 g were randomly selected for investigations and further divided into groups: 1) traditional ventilation (TV) (n=15); 2) HFJV (n=15). The rats were anesthetized with intraabdominal ketamine (6—8 mg/kg) and sibasone (15—45 mg). Anesthesia was maintained by the bolus administration of ketamine (1 mg/kg every 15—20 min). Tracheostomy was carried outwith a 0.2—0.4 mm diameter endotracheal tube that was then fixed using surgical thread 2—2.5 cm deep to the cricoid cartilage.Results. Acute respiratory distress syndrome (ARDS) has clear histological criteria for lung tissue structural injury; it is widely prevalent in clinical practice and associated with high mortality rates. The paper describes anexperimental ARDS model, the essence of which is 45—55% aspiration of the circulating blood volume for 10—15 minutes. A Reosorbilact® solution was used to compensate for the volume of blood loss, which was followed by the administration of autothromboplastin (16—20 mg/kg animal weight). PEEP was studied for its impact on gasexchange, hemodynamics, and blood oxygenation during HFJV and TV. Gas exchange parameters during TV and HFJV were comparatively analyzed.Conclusion. The use of PEEP for ARDS was ascertained to improve blood oxygenation due to decreased pulmonary shunt, better respiratory muscle performance, lower infiltrated and atelectatic tissue volumes, and higher lung functional residual capacityЦель исследования. Изучить влияние ВЧС ИВЛ и ТИВЛ с ПДКВ на оксигенацию крови, газообмен и гемодинамику на экспериментальной модели острого повреждения легких.Материал и методы. для проведения исследований на животных были отобраны в случайном порядке 30 самцов белых беспородных лабораторных крыс весом 200—300 г, с последующим разделением их на группы. 1 группа — для ТИВЛ (n=15). 2 группа — для ВЧС ИВЛ (n=15). Крысы были наркотизированы внутрибрюшинным введением кетамина (6—8 мг/кг) и сибазона (15—45 мг). Анестезию поддерживали болюсным введением кетамина (1 мг/кг каждые 15—20 мин.). Была произведена трахеостомия для установки эндотрахеальной трубки диаметром 0,2—0,4 мм, которая затем была фиксирована хирургической нитью на глубине 2—2,5 см от перстневидного хряща.Результаты. Острый респираторный дистресссиндром (ОРДС) имеет четкие гистологические критерии повреждения структур ткани легкого, широко распространен в клинической практике и сопровождается высокой летальностью. В статье описана экспериментальная модель ОРДС, сущность которой состоитв аспирации 45—55% от объема циркулирующей крови в течение 10—15 минут. Объем потери крови восполняли раствором Реосорбилакта® с последующим введением аутотромбопластина (16—20 мг/кг веса животного). Проведено исследование влияния положительного давления в конце выдоха (ПДКВ) на газообмен, гемодинамику и оксигенацию крови при высокочастотной струйной вентиляции легких (ВЧС ИВЛ) и традиционной искусственной вентиляции легких (ТИВЛ). Проведен сравнительный анализ параметров газообмена при применении ТИВЛ и ВЧС ИВЛ.Заключение. Выявлено, что применение ПДКВ при ОРДС улучшает оксигенацию крови вследствие уменьшения легочного шунта, облегчения работы дыхательных мышц, уменьшения объемов инфильтрированных и ателектатических тканей, а также повышения функциональной остаточной емкости легких

Clinical and neurophysiological analysis of correction of mild cognitive impairment in patients with dyscirculatory encephalopathy

Mnestic and mental disorders in cerebrovascular diseases are of great interest not only for neurologists, but also for medical specialists in related areas - neurosurgeons, therapists, psychiatrists. Cognitive disorders often complicate the course and prognosis of acute and chronic cerebrovascular disease [5]. According to the classification of E.V. Schmidt (1975), the term "dyscirculatory encephalopathy" (DE) is traditionally used to define the chronic form of cerebral vascular insufficiency [10]. Different stages of the disease are characterized by different degree of severity and type of cognitive impairment. The presence of such disorders in patients with DE is a criterion for a more accurate staging of the disease. In our opinion, if the degree of cognitive impairment is compared with the severity of cerebrovascular disease, then mild cognitive impairment corresponds to stage I-II DE [11]

Conversion of resins and asphaltenes under thermo-catalytic influence of magnetite at 200°C

© 2020 IOP Publishing Ltd. All rights reserved. This paper discusses the influence of magnetite on conversion of Ashal'cha heavy oil under the temperature of 200°C. The role of catalyst in in-situ upgrading of heavy oil is directed on the content reduction of high-molecular components such as resins and asphaltenes, as well as their molecular masses. The significant increase (10%) in the content of aromatic fraction and decrease in high-molecular hydrocarbons (8%) is observed. The results of measurements indicate the positive influence of catalyst on the rheology. Magnetite participates in destruction of associated complexes in resins and thereby decreases the viscosity of crude oil. The destruction products increase the content of light hydrocarbons, particularly saturates and aromatics. Investigation of temperature-dependent rheology characteristics revealed significant viscosity reduction in the products of catalytic aquathermolysis

Analysis of K-ras codon 12 and TP53 mutations in patients with advanced colorectal carcinoma

Background. Colorectal cancer (CRC) is one of the most common types of cancer, affecting 3 - 5% of the global population. K-ras protooncogene and TP53 tumour suppressor gene mutations are among the most common genetic alterations detected in advanced colorectaltumours.Objective. To investigate the role of K-ras codon 12 and TP53 exons 5 - 9 mutations in late-stage CRC patients.Methods. Blood samples were collected from 249 CRC patients, of whom 147 presented with advanced carcinoma. K-ras codon 12 mutations were analysed using polymerase chain reaction-restriction fragment length polymorphism, while direct sequencing was used in screening for TP53 exons 5 - 9 mutations.Results. No significant changes were observed in TP53 exons 5 - 9, except for two cases in which nucleotide replacements were observed in the non-coding regions in intron 4 (c.376-19C>T) and intron 9 (c.993+12T>C). Heterozygous mutations in K-ras codon 12 were observed in 79 individuals suffering from advanced CRC (53.7%). Colon and rectal tumours were equally distributed among the heterozygotes, but colon tumours were mostly present in wild-type homozygotes (84.6%). There was also a predominance of Caucasians among heterozygotes and a predominance of Asians among the wild-type homozygotes.Conclusion. Analysis of peripheral blood samples of CRC patients suffering from advanced carcinoma has prognostic value only for K-ras codon 12 mutations, and not for TP53 mutations

The Composition and Structure of Ultra-Dispersed Mixed Oxide (II, III) Particles and Their Influence on In-Situ Conversion of Heavy Oil

This paper discusses the role of magnetite in the conversion of heavy oil from the Ashal’cha reservoir. The effect of catalysts on the in-situ upgrading of heavy oil is directed on the reduction of high-molecular components of oil such as resins and asphaltenes and their molecular masses. Moreover, it is directed on the significant increase in saturates and aromatic fractions. Measuring the temperature-dependent viscosity characteristics revealed the tremendous viscosity decrease of the obtained catalytic aquathermolysis products. X-ray analysis exposed the composition of the initial catalyst that consisted of mixed iron oxides (II, III), as well as catalysts that were extracted from the treated crude oil. The particle size of the catalysts was investigated by scanning electron microscopy. According to the SEM data, aggregates of 200 nm were formed that were in the range of ultra-dispersed particles (200 to 500 nm)