Периоперационная динамика сывороточной концентрации глиального фибриллярного кислого протеина и замедленное когнитивное восстановление: экспериментальное обсервационное исследование

A number of studies have found an association between the increased concentration of glial fibrillar acid protein (GFAP) in blood serum in patients with various types of brain damage (ischemic stroke, traumatic brain injury, neurodegenerative and neuro-oncological diseases), as well as with a rapid decline in cognitive functions in elderly people with initially normal cognitive abilities.The objective: to identify the relationship between delayed cognitive recovery and changes in serum GFAP concentration in the perioperative period in patients operated for various oncological diseases.Subjects and Methods. The study included 30 patients who underwent surgical treatment for prostate cancer, colorectal cancer and pancreatic cancer under combined general anesthesia.The inclusion criteria were the expected duration of the operation over 300 minutes and the age over 60 years. GFAP was determined in plasma by enzyme immunoassay before anesthesia, the next day after surgery and on the 4th–5th day. Neuropsychological testing was performed before surgery and on the 4th–5th postoperative day. Delayed cognitive recovery was defined as a decrease in the composite z-score of more than one standard deviation (SD) compared to the preoperative assessment.Correlation analysis was performed between changes in the composite z-score (in absolute values) and the difference in GFAP concentration between the outcome and the first postoperative day, the outcome and the 4th–5th postoperative day and the first and 4th–5th postoperative days.Results. In five cases (16.6%), a decrease in the composite z-score > 1 SD was revealed indicating a delayed cognitive recovery. In the remaining 25 (83.4%) patients, changes in the composite z-score were less than one standard deviation. The median concentration of GFAP in patients with delayed cognitive recovery was 0.13 [0.1; 0.14] before surgery, 0.12 [0.09; 0.14] the day after surgery and 0.16 [0.05; 0.19] on the 4th–5th day after surgery. In patients without cognitive impairment, the concentration of GFAP was 0.15 [0.125; 0.184] before surgery, 0.15 [0.121; 0.163] 24 hours after surgery and 0.13 [0.079; 0.151] on the 4th–5th day after surgery. The correlation values between changes in the composite z-score and the difference in GFAP concentrations were: between the outcome and the first postoperative day – rs = 0.107, p = 0.37, outcome and the 4th–5th postoperative day – rs = 0.134, p = 0.37, the first and 4th‒5th postoperative days – rs = 0.21, p = 0.37.Discussion. There was no statistically significant difference in GFAP levels between patients with delayed cognitive recovery and patients without cognitive impairment. There was also no correlation between the difference in GFAP concentrations in plasma before surgery and 24 hours after, before surgery and on the 4th–5th day of the postoperative period and the composite z-score.Conclusions. The use of GFAP to predict cognitive decline associated with surgical treatment of colorectal cancer, prostate cancer and pancreatic cancer under general anesthesia is not yet possible.В ряде исследований была обнаружена связь между повышенной концентрацией глиального фибриллярного кислого протеина (GFAP) в сыворотке крови у пациентов с различными вариантами поражения головного мозга (ишемическим инсультом, травматическим повреждением головного мозга, нейродегенеративными и нейроонкологическими заболеваниями), а также с быстрым снижением когнитивных функций у пожилых людей c исходно нормальными когнитивными способностями.Цель: выявить взаимосвязь между замедленным когнитивным восстановлением и изменением концентрации GFAP сыворотки крови в периоперационном периоде у пациентов, оперированных по поводу различных онкологических заболеваний.Материал и методы. В исследование включено 30 пациентов, перенесших оперативное лечение по поводу рака предстательной железы, колоректального рака и рака поджелудочной железы в условиях комбинированной общей анестезии. Критериями включения были ожидаемая продолжительность операции более 300 мин и возраст более 60 лет. GFAP определяли в плазме иммуноферментным анализом до введения анестезии, на следующий день после операции и на 4‒5-е сут. Нейропсихологическое тестирование выполняли до операции и на 4‒5-й послеоперационный день. Замедленное когнитивное восстановление определяли как снижение композитного z-балла более одного стандартного (SD) отклонения по сравнению с предоперационной оценкой. Корреляционный анализ проводили между изменениями композитного z-балла (в абсолютных значениях) и разницей в концентрации GFAP между исходом и первым послеоперационным днем, исходом и 4‒5-м послеоперационным днем и первым и 4‒5-м послеоперационными днями.Результаты. В 5 (16,6%) случаях выявлено снижение композитного z-балла > 1 SD, что указывало на замедленное когнитивное восстановление. У остальных 25 (83,4%) пациентов изменения композитного z-балла были менее одного стандартного отклонения. Медиана концентрации GFAP у пациентов с замедленным когнитивным восстановлением составила 0,13 [0,1; 0,14] до операции, 0,12 [0,09; 0,14] на следующий день после операции и 0,16 [0,05; 0,19] на 4‒5-е сут после операции. У пациентов без когнитивных нарушений концентрация GFAP составила 0,15 [0,125; 0,184] до операции, 0,15 [0,121; 0,163] через 24 после операции и 0,13 [0,079; 0,151] на 4‒5-е сут после операции. Значения корреляции между изменениями композитного z-балла и разницей концентраций GFAP составили: между исходом и первым послеоперационным днем – rs = 0,107, p = 0,37, исходом и 4‒5-м послеоперационным днем – rs = 0,134, p = 0,37, первым и 4‒5-м послеоперационными днями – rs = 0,21, p = 0,37.Обсуждение. Не выявлено статистически значимой разницы в уровнях GFAP между пациентами с замедленным когнитивным восстановлением и пациентами без когнитивных нарушений. Также не обнаружено корреляции между разницей концентраций GFAP в плазме до операции и через 24 ч после, до операции и на 4‒5-е сут послеоперационного периода и композитным z-счетом.Выводы. Использование GFAP для прогнозирования снижения когнитивных функций, связанного с оперативным лечением колоректального рака, рака предстательной железы и рака поджелудочной железы в условиях общей анестезии, пока не представляется возможным

Modern Challenges for Oil and Gas Education

Today, in education in general and in higher education in particular, there is no more pressing problem than the organization of the educational process in the context of a pandemic that all universities in the world are facing. Also, there are no universal recipes for how to organize educational and scientific processes in a university without losing quality. The authors share their experience on how to restructure the work of teachers with students in the context of distance communication, organize the work of an educational portal, conduct training sessions, internships, state final certification, create motivational remuneration for the teaching staff. The article concludes that the challenges of the pandemic to higher education made it possible to find algorithms for interaction between students and teachers in the online environment, showed the need to improve the methodological qualifications of teachers, motivational and psychological support for participants in the educational process, accelerate the development of digital resources

Certain aspects of using Z-score to assess cognitive disorders

Detailed psychological testing is needed to identify cognitive impairments after anesthesia and surgery. This problem can be solved by development of the program of combination psychological tests with their assessment based on the Z-score, also known as the standard deviation test.The objective: to determine reference values of psychological tests to assess the results of Z-score.Subjects and methods. The study was included 30 healthy volunteers and 43 patients who underwent surgery. The panel of psychological tests consisted of the clock drawing test, oral counting test, assessment of short-term memory, sequence set, Digit Symbol Substitution Test, and the classic Stroop test. The mean values and standard deviations were calculated for each of the groups to evaluate the test results by Z-score.Results. It was found that using standard deviations obtained in the group of healthy volunteers as reference values for Z-score resulted in a higher percentage of deterioration in the result of repeated tests compared to using reference values obtained in group of patients.Conclusion: When using Z-score for cognitive tests, it is better to use the means and SD obtained in a group of healthy volunteers taking into account the possibility of finding differences where there are none (type I error)

The role of transport corridors in Timan-North Ural Region mineral-raw-material base Development

The development of mineral-raw-material base on underdeveloped territories of the Urals North and Timan is determined by the capabilities of inter-regional cooperation on the basis of the new transport corridors creation. The failure of the «Industrial Ural — Polar Ural» project substantially defined the attitude to the mineral-raw material base of the Ural North; but the actual analysis of the project failure causes does not allow to blame the mineral-raw-material base in that fact. This paper considers the prospects of Timan — North Ural region mineral-raw-material base development and the existing problems of nowadays, The question of revaluation necessity as of the regions existing mineral resource base, as well as the possible variants of its transport development is raised

Vortex Patterns in a Cross Flow Past a Cylinder Near the Channel Wall at Moderate Reynolds Numbers

Abstract: Physical experiment and direct numerical simulation are employed to study a transitional flow of viscous fluid past a spanwise circular cylinder mounted near the wall of a rectangular channel. The Reynolds number varies in the range of 60 to 480. Spiraling tornado-like motion of fluid directed from the sidewalls toward the center of the channel behind the cylinder is discovered. The evolution of this motion with the Reynolds number is outlined. Formation of large-scale vortical structures (analogue of Karman vortex street) and their turbulent breakdown in the cylinder wake are described. The behavior of the drag coefficient of the cylinder and the nearest wall with the Reynolds number is revealed