Prospects For the Use of Loop Isothermal Amplification in the Diagnosis of Particularly Dangerous Infectious Diseases Caused by the Viruses of the Pathogenicity Group I

Dangerous viral infectious diseases pose a serious threat to human life and health, as their uncontrolled spread leads to the development of major outbreaks and epidemics. Rapid and accurate detection of the pathogen is an essential component of the fight against infectious diseases. This review is devoted to loop-mediated isothermal amplification (LAMP), which is one of the simplest and most reliable methods of molecular-genetic research that meets modern requirements. The simplicity of the analysis and registration of the obtained results, which is necessary under conditions with minimal laboratory capacities, makes it possible to consider this type of diagnostic technology as the most promising, which allows us to identify genetic markers (DNA or RNA) of pathogens of dangerous infectious diseases in the shortest possible time. Objective of the review is to summarize and systematize the data available to date on the use of LAMP for detecting RNA of dangerous infectious diseases caused by the Ebola,Marburg and Lassa viruses. The paper discusses the basic principles of the loop isothermal amplification reaction, the components that make up the reaction mixture and are used for the analysis, as well as methods for detecting the results obtained. When studying the information available in the literature sources about the advantages and disadvantages of LAMP, it is shown that in many cases, isothermal amplification is not inferior in sensitivity and specificity to the main molecular-genetic diagnostic methods currently used. Modifications that can be used for accelerated diagnostics of RNA-containing viruses are also considered

Methodology for knowledge portals development: background, foundations, experience of application, problems and prospects

The paper discusses an experience of using the methodology for the development of knowledge portals which provide systematization and integration of scientific and engineering knowledge and information resources as well as the content-based access to them. To provide a sufficiently complete and consistent representation of knowledge and information resources, their systematization and integration are performed on the basis of ontology. The suggested methodology has been successfully applied to the development of knowledge Internet portals on archaeology, computational linguistics, strength of materials and Antarctic data

Sequelae of COVID-19 at long-term follow-up after hospitalization

Aim. To assess long-term sequelae of COVID-19 in hospitalized patients at 3 to 7 months after discharge.Material and Methods. The whole of 700 patients hospitalized to the temporary COVID-19 treatment center hosted by the FSBI “National Medical Research Center of Cardiology” of the Ministry of Health of Russia from April to June 2020 were invited to participate in a follow-up study. At 3-7 months after the index hospitalization, patients or their proxies were contacted via telephone in order to obtain information on their vital status, cardiovascular and other conditions or their complications, and new hospitalizations. In addition, patients were invited to an outpatient visit under the "COVID-19-follow-up" program, encompassing physical examination and a comprehensive battery of laboratory and instrumental tests, including spirometry, chest computed tomography (CT) and the six minute walk test (6MWT). Further, dyspnea was assessed using the mMRC (Modified Medical Research Council) Dyspnea Scale. Results: We were able to contact 87.4% (612/700) of patients or their proxies. At follow-up, 4.4% (27) patients died, of which 96.3% (26) had cardiovascular diseases (CVD). A total of 213 patients aged 19 to 94 years old (mean age 56.8±12.5, median 57 years [49.0; 64.0]; men, 55.4%) agreed come for an outpatient visit and to participate in the “COVID-19-follow-up” program. Since discharge, 8% (17) of patients required new hospitalizations, and more than a half of these patients (58.8%; 10/17) had CVD-related hospitalizations. A total of 8.4% (18) patients experienced worsening of hypertension, 9 (4.2%) patients had newly diagnosed hypertension, 2 (0.9%) – coronary artery disease patients experienced new/recurrent angina symptoms. 4 (1.9%) patients had newly diagnosed coronary artery disease, and one patient had an ischemic stroke. At the outpatient visit, 114 (53.5%) patients had some symptoms, most frequently, shortness of breath (33%), fatigue (27.4%), chest pain (11.3%), and abnormal heartbeats (8.5%). Based on the mMRC Scale, 59% of patients had dyspnea of varying severity. Most patients had a normal vital capacity (VC), which was moderately reduced in 3.3% and severely reduced in 0.5% of patients. Chest CT scans were obtained in 78 (36.6%) patients, whose worst lung damage scores during hospitalization were CT3 or CT4. One in ten patients (10.8%) with severe lung damage during acute infection had persisting ground glass opacities, 35.9% developed fibrotic changes, 79.6% of patients had linear or fine focal opacities. According to the 6MWT data, 12.3% of patients walked less than 70% of the predicted distance, 67% walked 71 to 99% of the predicted distance, and 20.7% of patients were able to walk 100% of their predicted distance.Conclusion. These data suggest long-term negative sequelae of COVID-19 in more than half of hospitalized patients

Studies of Ebola Virus persistence in the Body Fluids of a Patient at Advanced Stages of Convalescence

At present EVD epidemic, which claimed the lives of more than 10000 people, is still underway in West Africa Countries. Promptness and quality of laboratory diagnostics, alongside with delivered anti-epidemic measures predetermine efficacy of Ebola response operation. Due to a lack of means for the specific prophylaxis and treatment of the disease, asymptomatic patients are discharged from hospitals, based on criteria recommended by WHO, which might be insufficient. Viral RNA is detected in different clinical samples taken from the patients even at the advanced stages of convalescence, which requires essential investigation of peculiarities of Ebola persistence in various biological fluids. The article contains the data on the studies of biological samples, obtained from a female patient diagnosed with Ebola virus disease, applying various methods and techniques

Analysis of Ebola virus Zaire 2014 isolates

Analysis of 5 Ebola virus Zaire 2014 isolates passaged in cell cultures or in mice, demonstrated presence of unique mutations in the genome RNA in some cases. All identified nucleotide substitutions are singular, stochastically located, synonymous or fall within non-coding regions. Variability level of nucleotide sequences is equal to 0.005-0.01 %, suggesting extremely high genetic stability of Ebola virus Zaire, the causative agent of the outbreak. Confirmed is suppression of non-synonymous mutations accumulation in ebolavirus variants in the course of time. Detected are alterations in glycosilation sites and mucin-like domain of ebolavirus glycoprotein

СУБТРАКЦИОННАЯ КТ-АНГИОПУЛЬМОНОГРАФИЯ В ДИАГНОСТИКЕ ХРОНИЧЕСКОЙ ТРОМБОЭМБОЛИЧЕСКОЙ ЛЕГОЧНОЙ ГИПЕРТЕНЗИИ

Purpose. To assess the state of the vascular bed and perfusion of the lungs in patients with chronic thromboembolic pulmonary hypertension (CTEPH) by the method of subtraction computed tomography (CT).Materials and methods. Between November 2015 and May 2018, 65 patients with diagnosis of CTEPH were examined. All patients were examined on a computer tomograph Aquilion ONE 640 VISION Edition (Toshiba Medical Systems) with 320 rows of detectors, slice thickness – 0,5 mm. Assessment of perfusion disorders was carried out using new software, which allows combining contrast and noncontrast images by subtraction. Were analyzed parameters of the parenchyma, blood supply and perfusion status with the calculation of indices of obstruction and perfusion disorders. The obstruction index was compared with the index of perfusion abnormalities, a 6-minute walk test, and mean pulmonary artery pressure according to the right heart catheterization data. Results. The significant correlation was found between the obstruction index and the index of perfusion disorders in patients with CTEPH (r = 0.605; p = 0.000001). Interrelations between vascular-perfusion indices (an obstruction index and an index of perfusion disorders), mean pulmonary artery pressure and distance in a 6-minute walk test were not revealed.Conclusion. Subtraction CT pulmonary angiography allows to assess the severity of vascular lesion and perfusion disorders within a single study, also determine the effectiveness of treatment in patients with CTEPH.Цель исследования: оценить состояние сосудистого русла и перфузии легких у больных хронической тромбоэмболической легочной гипертензией (ХТЭЛГ) методом субтракционной компьютерной томографии (КТ).Материал и методы. В период с ноября 2015 г. по май 2018 г. было обследовано 65 пациентов с диагнозом ХТЭЛГ. Все пациенты были обследованы на компьютер-ном томографе Aquilion ONE 640 VISION Edition (Toshiba Medical Systems) с 320 рядами детекторов, толщина томографического среза 0,5 мм. Оценка перфузионных нарушений выполнялась с помощью нового программного обеспечения, которое позволяет совмещать контрастные и бесконтрастные изображения методом субтракции. Анализировались параметры состояния паренхимы, кровоснабжения и перфузии легких с расчетом индексов обструкции и перфузионных нарушений. Индекс обструкции был сопоставлен с индексом перфузионных нарушений, тестом 6-минутной ходьбы (Т6МХ) и средним давлением в легочной артерии (ср. ДЛА) по данным катетеризации правых отделов сердца.Результаты. Между индексом обструкции и индексом перфузионных нарушений у больных ХТЭЛГ была обнаружена статистически значимая корреляция (r = 0,605; p = 0,000001). Взаимосвязей между сосудисто-перфузионными показателями (индексом обструкции и индексом перфузионных нарушений), ср.ДЛА и пройденной дистанцией в Т6МХ выявлено не было.Заключение. Использование субтракционной КТ-ангиопульмонографии позволяет оценить выраженность сосудистого поражения и перфузионных нарушений в рамках одного исследования, а также определить эффективность лечения у пациентов с ХТЭЛГ

Circulation of Lyssaviruses (Lyssavirus) among the Small Mammals in the Territory of the Republic of Guinea

Objective is to study the role of small mammals, habitant in the Republic of Guinea, in Lyssavirus circulation. Materials and methods. Investigations were conducted using RT-PCR; nucleotide sequence of Lyssavirus cDNA fragments was identified with the help of sequencing with further phylogenetic analysis. Results and conclusions. Tested have been 356 brain samples from small mammals for the presence of Lyssavirus RNA using RT-PCR with genus-specific primers. The animals were caught in the suburbs of Kindia city in 2016. The samples were obtained from wild animals pertaining to Rodentia, Chiroptera, Eulipotyphla, and Carnivora orders.Lyssavirus RNA was detected in 31 samples (8.7 %). For 14 PCR positive samples the appurtenance to Lyssavirus was confirmed through identification and analysis of nucleotide sequences of the collected short cDAN fragments of viral genome. The presence of rabies virus RNA in positive tests was excluded from PCR with the help of species specific primers. The pool of samples from black rats, Rattus rattus, positive for Lyssavirus RNA, contained RNA characteristic of Mokola lyssavirus species. Specified has been nucleotide sequence of matrix protein M gene fragment of Mokola virus. Genetic material of Mokola virus was detected in the Republic of Guinea for the first time ever

Особенности характеристик миокарда пациентов с острым инфарктом миокарда с подъемом сегмента ST и сахарным диабетом по данным магнитно-резонансной томографии сердца с контрастированием

Introduction. The presence of diabetes mellitus in patients with acute infarction significantly worsens short- and long-term prognosis, but the features of the course of the infarction in this category of patients have not been fully studied.Objective. To compare clinical, functional and structural myocardial characteristics of patients with acute ST-segment elevation myocardial infarction with and without diabetes mellitus.Materials and methods. The study included 91 patients with revascularized ST-segment elevation myocardial infarction (41 patients with diabetes mellitus). All patients underwent cardiac MRI with contrast, including myocardial T1 mapping, tissue analysis of left ventricular myocardium with determination of infarct zone, heterogeneous zone, edema zone, pre- and post-contrast T1 values, extracellular volume values of healthy myocardium and infarct zone.Results. The presence of diabetes in patients with AMI was associated with increased EDV LV: 153 ± 38 and 181 ± 58 ml (p = 0.007), increased ESV LV: 76 ml [54–93] and 87 ml [71–122] (p = 0.035). Infarct size was significantly larger in patients with diabetes than in those without diabetes: 37 ± 15 g (95% CI: 33–41) and 47 ± 21 g (95% CI: 40–53), p = 0.017. Patients with acute infarction and diabetes mellitus had higher extracellular volume values in both healthy myocardium: 24% [22–27] and 28% [24–30], p = 0.002, and in the infarct zone: 48% [40–58] and 58% [50–61], p = 0.016.Conclusions. In patients with ST-segment elevation myocardial infarction with diabetes mellitus, the infarct size, the edema area, and the value of the extracellular volume fraction both in the infarct area and in the preserved myocardium were larger than in patients without diabetes, which may underlie the development of myocardial dysfunction and further progression of heart failure.Введение. Наличие сахарного диабета (СД) у пациентов с острым инфарктом миокарда (ОИМ) существенно ухудшает краткосрочный и долгосрочный прогноз, однако особенности течения инфаркта у данной категории пациентов до конца не изучены.Цель. Сравнить клинические, функциональные и структурные характеристики миокарда пациентов с ОИМ с подъемом сегмента ST с СД и без СД.Материалы и методы. В исследование включен 91 пациент с реваскуляризированным острым инфарктом миокарда с подъемом сегмента ST (41 пациент с СД, 50 пациентов без СД). Всем пациентам выполнена МРТ сердца с контрастированием, в том числе Т1-картирование миокарда, проведен тканевой анализ миокарда левого желудочка с определением зоны инфаркта, гетерогенной зоны, зоны отека, значений до- и постконтрастного Т1, фракции внеклеточного объема здорового миокарда и инфарктной зоны.Результаты. Наличие СД у пациентов с ОИМ ассоциировалось с увеличенным конечным диастолическим объемом левого желудочка: 153 ± 38 и 181 ± 58 мл (р = 0,007), увеличенным конечным систолическим объемом левого желудочка: 76 мл [54–93] и 87 мл [71– 122] (р = 0,035). Размер инфаркта у пациентов с СД был достоверно больше, чем у пациентов без СД: 37 ± 15 г (95% ДИ 33–41) и 47 ± 21 г (95% ДИ 40–53), р = 0,017. У пациентов с ОИМ и СД фракция внеклеточного объема была выше и в здоровом миокарде: 24% [22–27] и 28% [24–30], р = 0,002, и в инфарктной зоне: 48% [40–58] и 58% [50–61], р = 0,016.Заключение. У пациентов с инфарктом миокарда с подъемом сегмента ST и СД размер инфаркта, зона отека, а также значение фракции внеклеточного объема как в зоне инфаркта, так и в сохранном миокарде были больше, чем у пациентов без СД, что может лежать в основе развития дисфункции миокарда и дальнейшего прогрессирования сердечной недостаточности

Диагностическая эффективность перфузионной компьютерной томографии миокарда с чреспищеводной электрокардиостимуляцией у больных с исходным диагнозом «острый коронарный синдром»

Introduction. Computed tomography angiography (CTA) is widely used to detect atherosclerotic changes in coronary arteries (CA). However, the method is limited by the impossibility to perform functional assessment of detected stenoses. Perfusion computed tomography of the myocardium (PCT) can be used for this purpose.Aim of the study. To assess diagnostic accuracy of PCT of the myocardium with transesophageal electrocardiostimulation (TEES) and stress-echocardiography (stress-echoCG) with veloergometry (VEM) in detection of transient ischemia in patients with initial diagnosis of “acute coronary syndrome” (ACS) with borderline stenoses (50–75%) in CA in relation to measurements of fractional flow reserve (FFR).Materials and Methods. The study included 30 patients with the initial diagnosis of ACS with borderline (50–75%) stenoses in CA according to CTA or coronary angiography (CAG). Subsequently, they underwent myocardial PCT with 320-row detector with TEES, as well as stress-echoCG with VEM. Invasive FFR measurement was used as a reference method. FFR value < 0.8 indicated hemodynamic significance of stenosis. Myocardial perfusion was assessed visually. Regional myocardial contractility of the left ventricle was assessed by stress-echoCG.Results. All patients were examined according to the stated protocol. PCT with TEES revealed FFR-significant stenoses with sensitivity, specificity, prognostic value of positive result and prognostic value of negative result 56, 93, 90, 65% respectively, stress-echoCG with VEM 62, 93, 91, 68% respectively.Conclusion. Myocardial PCT with TEES enables to detect perfusion defects associated with transient ischemia, and the diagnostic accuracy of the method in comparison with FFR is comparable with the already well-proven stress-echoCG. The use of PCT with TEES in combination with CTA can be considered as a promising diagnostic tool in patients without known coronary anatomy and with suspected ACS.Введение. Компьютерная томографическая ангиография (КТА) широко используется для выявления атеросклеротических изменений в коронарных артериях (КА). Однако метод ограничен невозможностью проведения функциональной оценки выявленных стенозов. С этой целью может использоваться перфузионная компьютерная томография миокарда (ПКТ).Цель исследования. Оценить диагностическую точность методов ПКТ миокарда с чреспищеводной электрокардиостимуляцией (ЧПЭС) и стресс-эхокардиографии (стресс-ЭхоКГ) с велоэргометрией (ВЭМ) в выявлении преходящей ишемии у больных с исходным диагнозом «острый коронарный синдром» (ОКС) с пограничными стенозами (50–75%) в КА по отношению к измерениям фракционного резерва кровотока (ФРК).Материалы и методы. В исследование были включены 30 больных с исходным диагнозом ОКС с пограничными (50–75%) стенозами в КА по данным КТА или коронарной ангиографии (КАГ). Впоследствии им были выполнены ПКТ миокарда на томографе с 320-рядным детектором с ЧПЭС, а также стресс-ЭхоКГ с ВЭМ. В качестве референтного метода использовалось инвазивное измерение ФРК. Значение показателя ФРК < 0,8 указывало на гемодинамическую значимость стеноза. Перфузия миокарда оценивалась визуально. При проведении стресс-ЭхоКГ оценивалась региональная сократимость миокарда левого желудочка.Результаты. Все больные обследованы согласно заявленному протоколу. ПКТ с ЧПЭС выявила ФРК-значимые стенозы с чувствительностью, специфичностью, прогностической ценностью положительного результата и прогностической ценностью отрицательного результата 56, 93, 90, 65% соответственно, стресс-ЭхоКГ с ВЭМ 62, 93, 91, 68% соответственно.Выводы. ПКТ миокарда с ЧПЭС позволяет выявить дефекты перфузии, ассоциированные с преходящей ишемией, а диагностическая точность метода при сравнении с ФРК сопоставима с уже хорошо зарекомендовавшей себя стресс-ЭхоКГ. Использование ПКТ с ЧПЭС в комбинации с КТА можно рассматривать как перспективный диагностический инструмент у больных без известной коронарной анатомии и с подозрением на ОКС

THE PERSISTENT TRIGEMINAL ARTERY AS EVIDENCED BY MULTISLICE SPIRAL COMPUTED TOMOGRAPHIC ANGIOGRAPHY

Objective: to determine the incidence of the persistent trigeminal artery (PTA) and to reveal its relationship to cerebral aneurysms, as well as the concomitant anatomic features of cerebral arteries according to the data of multislice spiral computed tomographic angiography (CTA).Material and methods. A total of 1041 patients underwent brachiocephalic artery CTA according to different clinical indications. PTA and cerebral arterial aneurysms were found on the computed tomographic angiograms and the anatomic features of the structure of the circle of Willis were assessed.Results. PTA was identified in 6 (0.58%) of the 1041 patients. Cerebral aneurysm was present in only one patient with PTA and concurrent with hypoplasia of the contralateral A1 segment of the anterior cerebral artery. Hypoplasia of the basilar artery (BA) and both vertebral arteries (VA) was observed in 3 (60%) cases, with the diameter of PTA at its confluence with BA exceeding 3 mm. When the diameter of BA was normal, that of PTA was less than 2 mm. All PTAs were wider at their base, by decreasing in diameters distally.Conclusion. CTA showed that the incidence of PTA was 0.58% and its lateral type according to the Salas classification and Saltzman’s type 1 were more common (5/6). In 4 cases, PTA was concurrent with VA and BA hypoplasia, with its degree being inversely related to the distal diameter of PTA. There was no convincing evidence for a relationship of PTA to cerebral aneurysms