Clinical and functional characteristics of the post-COVID period (6-month follow-up)

Respiratory symptoms and functional disorders are registered in patients who suffered from COVID-19 (COronaVIrus Disease 2019). Aim. Clinical and functional evaluation of the respiratory system during 6-month follow-up in patients who had moderate and severe COVID-19. Methods. 80 patients were included in the cohort observational prospective study. Patients were examined in 46 (36 – 60) days from the onset of symptoms of COVID-19. and in 93 (89 – 103) and 180 (135 – 196) days at the 2nd and 3rd stages respectively. At all stages, symptoms, dyspnea level, and quality of life were analyzed using validated questionnaires, and a 6-minute step test was performed. At the 2nd and 3rd stages, we assessed spirometric parameters, total lung capacity, carbon monoxide diffusing capacity (DLCO), and high resolution computed tomography scans of chest organs. Results. At the 1st stage of the study, 62% of patients complained of fatigue, muscle weakness, 61% of patients had dyspnea of variable severity. At the 3rd stage of the study, 43% and 42% of patients had the same complaints respectively. The prevalence of moderate COVID-19 form in patients with 35 (25 – 45)% lung damage and severe COVID-19 form with 75 (62 – 75)% of lung damage was established. At the 2nd stage, a DLCO < 80% level was recorded in 46% of patients with 35 (25 – 45)% lung damage and in 54% of patients with 75 (62 – 75)%. At the 3rd stage, DLCO < 80% was diagnosed in 51.9% and 48.1% of patients with of 35 (25 – 45)% and 75 (62 – 75)% lung damage respectively. The level of DLCO < 60% was found in 38,5% and 35,5% of patients with moderate and severe lung damage at the 2nd and 3rd stages of the study respectively. Conclusion. The symptoms were reported less frequently during the 6-month follow-up after COVID-19. 77% and 87% of patients had DLCO < 80% in 93 (89 – 103) and 180 (135 – 196) days after the disease onset, respectively. 38.5% and 35.5% of those patients, predominantly having suffered COVID-19 in severe form, had DLCO < 60% at 93 (89 – 103) and 180 (135 – 196) days, respectively. This calls for a continuous observation and regular examinations after COVID-19.У пациентов, перенесших COVID-19 (COronaVIrus Disease 2019), регистрируются респираторные жалобы и функциональные нарушения. Целью исследования явилась клинико-функциональная оценка респираторной системы в течение 6 мес. наблюдения у больных, перенесших COVID-19 среднетяжелой и тяжелой степени. Материалы и методы. В когортное наблюдательное проспективное исследование включены пациенты (n = 80), обследованные через 46 (36–60) дней от первых симптомов COVID-19, на 2-м и 3-м этапах – через 93 (89–103) и 180 (135–196) дней соответственно. На всех этапах анализировались жалобы, уровень одышки, качество жизни с использованием валидизированных опросников, проводился 6-минутный шаговый тест. На 2-м и 3-м этапах оценивались спирометрические показатели, общая емкость легких, диффузионная способность легких по монооксиду углерода (DLCO), данные компьютерной томографии высокого разрешения. Результаты. На 1-м этапе исследования 62 % пациентов предъявляли жалобы на усталость, мышечную слабость, 61 % – испытывали одышку различной степени выраженности. К 3-му этапу наблюдения аналогичные жалобы отмечались у 43 и 42 % пациентов соответственно. Установлено преобладание среднетяжелой формы COVID-19 при объеме поражения 35 (25–45) % легочной ткани и тяжелой формы – при поражении 75 (62–75) %. На 2-м этапе уровень DLCO < 80 % зарегистрирован у 46 % пациентов при поражении 35 (25–45) % легочной ткани, у 54 % пациентов – при 75 (62–75) %. На 3-м этапе DLCO < 80 % диагностирован у 51,9 и 48,1 % пациентов при поражении 35 (25–45) и 75 (62–75) % легких соответственно. Уровень DLCO < 60 % определялся у 38,5 и 35,5 % пациентов при среднетяжелом и тяжелом поражении легких на 2-м и 3-м этапах исследования соответственно. Заключение. В течение 6 мес. наблюдения после перенесенного COVID-19 отмечается уменьшение частоты предъявляемых жалоб. Через 93 (89–103) и 180 (135–196) дней от начала заболевания показатель уровня DLCO < 80 % установлен у 77 и 87 % пациентов соответственно. У 38,5 и 35,5 % пациентов, перенесших COVID-19 преимущественно в тяжелой форме, определяется DLCO < 60 % на 93-й (89–103) и 180-й (135–196) дни соответственно, что является показанием для дальнейшего наблюдения и обследования в постковидном периоде

Клинико-функциональная характеристика постковидного периода (6-месячное наблюдение)

Respiratory symptoms and functional disorders are registered in patients who suffered from COVID-19 (COronaVIrus Disease 2019). Aim. Clinical and functional evaluation of the respiratory system during 6-month follow-up in patients who had moderate and severe COVID-19. Methods. 80 patients were included in the cohort observational prospective study. Patients were examined in 46 (36 - 60) days from the onset of symptoms of COVID-19 and in 93 (89 - 103) and 180 (135 - 196) days at the 2nd and 3rd stages respectively. At all stages, symptoms, dyspnea level, and quality of life were analyzed using validated questionnaires, and a 6-minute step test was performed. At the 2nd and 3rd stages, we assessed spirometric parameters, total lung capacity, carbon monoxide diffusing capacity (DLCO), and high resolution computed tomography scans of chest organs. Results. At the 1st stage of the study, 62% of patients complained of fatigue, muscle weakness, 61% of patients had dyspnea of variable severity. At the 3rd stage of the study, 43% and 42% of patients had the same complaints respectively. The prevalence of moderate COVID-19 form in patients with 35 (25 - 45)% lung damage and severe COVID-19 form with 75 (62 - 75)% of lung damage was established. At the 2nd stage, a DLCO &lt; 80% level was recorded in 46% of patients with 35 (25 - 45)% lung damage and in 54% of patients with 75 (62 - 75)%. At the 3rd stage, DLCO &lt; 80% was diagnosed in 51.9% and 48.1% of patients with of 35 (25 - 45)% and 75 (62 - 75)% lung damage respectively. The level of DLCO &lt; 60% was found in 38,5% and 35,5% of patients with moderate and severe lung damage at the 2nd and 3rd stages of the study respectively. Conclusion. The symptoms were reported less frequently during the 6-month follow-up after COVID-19. 77% and 87% of patients had DLCO &lt; 80% in 93 (89 - 103) and 180 (135 - 196) days after the disease onset, respectively. 38.5% and 35.5% of those patients, predominantly having suffered COVID-19 in severe form, had DLCO &lt; 60% at 93 (89 - 103) and 180 (135 - 196) days, respectively. This calls for a continuous observation and regular examinations after COVID-19.У пациентов, перенесших COVID-19 (COronaVIrus Disease 2019), регистрируются респираторные жалобы и функциональные нарушения. Целью исследования явилась клинико-функциональная оценка респираторной системы в течение 6 мес. наблюдения у больных, перенесших COVID-19 среднетяжелой и тяжелой степени. Материалы и методы. В когортное наблюдательное проспективное исследование включены пациенты (n = 80), обслсеюванные через 46 (36—60) дней от первых симптомов COVID-19, на 2-м и 3-м этапах — через 93 (89—103) и 180 (135—196) дней соответственно. На всех этапах анализировались жалобы, уровень одышки, качество жизни с использованием валидизированных опросников, проводился 6-минутный шаговый тест. На 2-м и 3-м этапах оценивались спирометрические показатели, общая емкость легких, диффузионная способность легких по монооксиду углерода (DLCO), данные компьютерной томографии высокого разрешения. Результаты. На 1-м этапе исследования 62 % пациентов предъявляли жалобы на усталость, мышечную слабость, 61 % — испытывали одышку различной степени выраженности. К 3-му этапу наблюдения аналогичные жалобы отмечались у 43 и 42 % пациентов соответственно. Установлено преобладание среднетяжелой формы COVID-19 при объеме поражения 35 (25—45) % легочной ткани и тяжелой формы — при поражении 75 (62—75) %. На 2-м этапе уровень DLCO &lt; 80 % зарегистрирован у 46 % пациентов при поражении 35 (25-45) % легочной ткани, у 54 % пациентов - при 75 (62-75) %. На 3-м этапе DLCO &lt; 80 % диагностирован у 51,9 и 48,1 % пациентов при поражении 35 (25-45) и 75 (62-75) % легких соответственно. Уровень DLCO &lt; 60 % определялся у 38,5 и 35,5 % пациентов при среднетяжелом и тяжелом поражении легких на 2-м и 3-м этапах исследования соответственно. Заключение. В течение 6 мес. наблюдения после перенесенного COVID-19 отмечается уменьшение частоты предъявляемых жалоб. Через 93 (89-103) и 180 (135-196) дней от начала заболевания показатель уровня DLCO &lt; 80 % установлен у 77 и 87 % пациентов соответственно. У 38,5 и 35,5 % пациентов, перенесших COVID-19 преимущественно в тяжелой форме, определяется DLCO &lt; 60 % на 93-й (89-103) и 180-й (135-196) дни соответственно, что является показанием для дальнейшего наблюдения и обследования в постковидном периоде

Deformation Behavior under Static and Cyclic Tension of Polymer Grafts without and after Modification by RGD Peptides

The structure, mechanical properties, and deformation behavior under static and cyclic tension of biofunctionalized biodegradable vascular grafts based on polyhydroxybutyrate/valerate and polycaprolactone were studied. It is shown that the modification gives rise to an almost twofold decrease of the elongation at break as well as the ultimate strength. It is shown that under cyclic loading the modification of grafts results in decreasing cyclic durability by more than twice. In doing so, the level of deforming stress decreases to a much lesser extent and is practically inferior to that for unmodified material. The analysis of principal strain [epsilon]1 and [epsilon]2 component distribution patterns in grafts of both types is carried out while the reason for the observed changes is discussed

Структура кальцификатов в биопротезах клапанов сердца, консервированных диглицидиловым эфиром этиленгликоля

Highlights. The morphology and elemental composition of calcium deposits formed in the tissues of epoxytreated aortic and mitral bioprostheses do not differ from those in the mineralized matrix of stenotic human aortic valve leaflets. Despite similar elemental composition of mineral deposits in the KemCor and UniLine bioprostheses, the morphology of these calcifications differs between bioprosthetic heart valve substitutes and, apparently, is associated with the specific structure of the fibrous matrix of the biological tissues that are used for their manufacturing.Aim. To analyze the morphology and elemental composition of mineral deposits formed in epoxy-treated aortic and mitral bioprosthetic heart valves made from xenoaortic or xenopericardial material and to compare the obtained findings with the data on calcified human aortic valve.Methods. Leaflets of the mitral and aortic bioprosthetic heart valves KemCor and UniLine (NeoKor, L Russia, Kemerovo) that were explanted due to their failure, as well as leaflets of the calcified native aortic valve were evaluated. The morphology of calcifications was studied by scanning electron microscopy using an S-3400N microscope (Hitachi, Japan). The elemental composition of calcium deposits was studied by electron probe microanalysis using Hitachi S-3400N microscope with energy dispersive spectrometer Bruker XFlash 4010 (Bruker, Germany).Results. Large calcifications located at the internal layers of samples were surrounded by collagen fibers commonly with evident signs of the onset of mineralization. Calcium deposits in the native aortic valve and xenoartic bioprostheses KemCor were located mainly at the spongy layer and had a loose structure, while dense lamellar deposits were found at the leaflets of pericardial bioprostheses UniLine. The elemental composition of calcium deposits showed the presence of Ca, P, O, Mg, and Na in the mineralized regions and the presence of S in the regions of low electron density. The calcium to phosphorus ratio (Ca:P) in the calcifications of the aortic valve leaflets was 1.81 (1.79-1.84; min - 1.48; max - 2.05), whereas the Ca:P ratios in the UniLine and KemCor bioprostheses were 1.78 (1.75-1.86; min - 1.52; max - 2.03) and 1.82 (1.81-1.88; min - 1.71; max - 2.06), respectively. There were no significant differences in the Ca:P ratios between calcifications in the study groups (p&gt;0.05).Conclusion. Calcium deposits detected in epoxy-treated bioprostheses and human aortic valve appeared to be formed under dystrophic calcification. The morphology of calcifications in bioprostheses depended on the type of biological tissue. None correlations between the morphological structure of calcifications and the implantation position were found in bioprosthetic leaflets. The elemental composition of mineral deposits was similar in all study samples.Основные положения. Морфология и элементный состав кальциевых депозитов, сформированных в тканях эпоксиобработанных биопротезов в аортальной и митральной позициях, не отличались от кальцификатов, выявленных в минерализованном матриксе створок стенозированного аортального клапана человека. Элементный состав минеральных отложений в биопротезах «КемКор» и «ЮниЛайн» одинаковый, тогда как морфология кальцификатов различалась между рассматриваемыми моделями клапанных заменителей и, по-видимому, обусловлена специфичностью строения волокнистого матрикса биоткани, использованной при их изготовлении.Цель. Сравнительный анализ морфологии и элементного состава минеральных отложений, образованных в створках эпоксиобработанных биопротезов, в зависимости от позиции имплантации (аортальной или митральной) и типа биоматериала (ксеноаортальный или ксеноперикардиальный); оценка кальциевых депозитов, сформированных в тканях протезных клапанов, относительно кальцификатов из пораженного клапана аорты человека.Материалы и методы. В исследовании использованы створки клапанных биопротезов «КемКор» и «ЮниЛайн» (ЗАО «НеоКор», Кемерово, Россия), эксплантированных из митральной и аортальной позиций по причине дисфункций, а также створки кальцинированного аортального клапана (АК), удаленного при его протезировании. Морфологию кальцификатов изучали методом сканирующей электронной микроскопии с использованием микроскопа S-3400N (Hitachi, Япония), их элементный состав - методом электронно-зондового микроанализа с помощью энергодисперсионного спектрометра XFlash 4010 (Bruker, Германия), входящего в конструкцию указанного микроскопа.Результаты. В изученных образцах обнаружены крупные внутренние кальцификаты, окруженные коллагеновыми волокнами, как правило, с признаками начала минерализации. В створках нативного клапана аорты и ксеноаортальных биопротезов «КемКор» кальциевые отложения располагались преимущественно в спонгиозном слое и имели рыхлую структуру, тогда как в створках перикардиальных протезов «ЮниЛайн» присутствовали плотные кальцификаты пластинчатой формы. Анализ элементного состава кальциевых депозитов показал присутствие Са, Р, O, Mg и Na в минерализованных участках и наличие S в областях с меньшей электронной плотностью. Соотношение Са/Р для кальцификатов в створках АК составило 1,81 (1,79-1,84; min - 1,48; max - 2,05), в створках биопротезов «ЮниЛайн» и «КемКор» - 1,78 (1,751,86; min - 1,52; max - 2,03) и 1,82 (1,81-1,88; min - 1,71; max - 2,06) соответственно. Достоверных различий в соотношении Са/Р между кальцификатами в исследованных группах не выявлено (р&gt;0,05).Заключение. Кальциевые депозиты, выявленные в ткани эпоксиобработанных биопротезов и АК человека, по-видимому, образованы посредством дистрофической минерализации. Морфология кальцификатов в биопротезах зависит от типа биологической ткани, в которой они сформированы. Связь между морфологической структурой кальцификатов, обнаруженных в створках биопротезов, и позицией имплантации изделий не выявлена. Элементный состав минеральных отложений не различался во всех изученных образцах

In Search of Possible Associations between Planetary Nebulae and Open Clusters

We consider the possibility of cluster membership for 13 planetary nebulae that are located in close proximity to open clusters lying in their lines of sight. The short lifetimes and low sample size of intermediate-mass planetary nebulae with respect to nearby open clusters conspire to reduce the probability of observing a true association. Not surprisingly, line of sight coincidences almost certainly exist for 7 of the 13 cases considered. Additional studies are advocated, however, for 6 planetary nebula/open cluster coincidences in which a physical association is not excluded by the available evidence, namely M 1-80/Berkeley 57, NGC 2438/NGC 2437, NGC 2452/NGC 2453, VBRC 2 & NGC 2899/IC 2488, and HeFa 1/NGC 6067. A number of additional potential associations between planetary nebulae and open clusters is tabulated for reference purposes. It is noteworthy that the strongest cases involve planetary nebulae lying in cluster coronae, a feature also found for short-period cluster Cepheids, which are themselves potential progenitors of planetary nebulae.Comment: Accepted for publication in PASP (December 2007

Method for non-invasive assessment of the structure of a heart valve bioprosthesis

Background. The study of explanted heart valve bioprostheses is a valuable source of information about the destructive processes in their components that develop as a result of prolonged contact with the recipient’s body. An analysis of the morphology, staging and degree of involvement of various valve prosthesis materials in the prevalence of pathological processes – calcification, mechanical damage, growth of the connective tissue capsule, is the basis for developing potential methods for increasing the service life of these products and reducing the risk of re-interventions. The aim of the study was to evaluate the potential of computed microtomography to analyze the internal structure of a biological prosthetic heart valve explanted due to dysfunction. Material and methods. In this work, we investigated the prevalence of pathological mineralization of the PeriCor bioprosthesis, explanted as a result of the developed dysfunction of the leaflet apparatus with a clinical picture of grade 2B prosthetic insufficiency. The material was described macroscopically, after which it was subjected to high-resolution computed microtomography. In the structure of the sample, X-ray dense areas of pathological mineralization were identified and described, and the volume of the material involved in calcification was assessed. Results. It was shown that the main pathological changes that led to prosthetic dysfunction were degenerative changes in the biomaterial with signs of calcification, thickening and rupture of the leaflets. It was quantitatively determined that the areas of radiologically dense inclusions (calcifications) occupy 11.1 % of the volume of the material. It has been established that the described areas are associated with the sheathing of the frame and with the elements of the suture material used in the production of this bioprosthesis. Conclusion. The method of non-destructive analysis of the internal structure of altered materials of a biological prosthesis studied in this work has demonstrated the possibility of а qualitative and quantitative assessment of areas of pathological mineralization, their distribution and connection with other processes leading to the development of prosthetic dysfunction. The method makes it possible to visualize macro- and microsites of calcification and can become a valuable tool to complement existing approaches to the study of explanted bioprostheses

IN SITU VASCULAR TISSUE REMODELING USING BIODEGRADABLE TUBULAR SCAFFOLDS WITH INCORPORATED GROWTH FACTORS AND CHEMOATTRACTANT MOLECULES

Background Currently, the search for the bioactive molecules capable of promoting formation of the vascular tissue is still ongoing. We have previously demonstrated that incorporation of the growth factors and chemoattractant molecules into the biodegradable tubular scaffolds can increase their primary patency upon the implantation into rat abdominal aorta. However, further studies are required to investigate tissue remodeling using functionalized vascular grafts with the same diameter as a replaced native vessel. Aim To investigate the specific aspects of de novo vascular tissue formation and calcification employing rat abdominal aorta interposition model and vascular grafts with 1.5 mm diameter with incorporated vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), and stromal cell-derived factor (SDF)-1α. Methods Tubular grafts with a diameter of 1.5 mm were blended of poly(3-hydroxybutyrateco-3-hydroxyvalerate) and poly(ε-caprolactone) (PHBV/PCL). Grafts without growth factors were fabricated using standard electrospinning technique whilst grafts with incorporated growth factors were prepared utilizing emulsion electrospinning. VEGF was incorporated into the inner third, whereas bFGF and SDF-1α were incorporated into the outer two-thirds of the graft. Grafts were implanted into the abdominal aortas of Wistar rats for 1, 3, 6, and 12 months following scanning electron microscopy along with histological and immunofluorescent examination. Results Primary patency of the grafts with VEGF, bFGF, and SDF-1α reached 93% indicative of structural integrity of the vascular tissue. Neither signs of inflammation nor severe calcification was detected. Conclusion As in 2 mm diameter vascular grafts, incorporation of bioactive factors into 1.5 mm diameter grafts increased their long-term primary patency and improved vascular tissue formation in comparison with non-modified grafts.  Background Currently, the search for the bioactive molecules capable of promoting formation of the vascular tissue is still ongoing. We have previously demonstrated that incorporation of the growth factors and chemoattractant molecules into the biodegradable tubular scaffolds can increase their primary patency upon the implantation into rat abdominal aorta. However, further studies are required to investigate tissue remodeling using functionalized vascular grafts with the same diameter as a replaced native vessel. Aim To investigate the specific aspects of de novo vascular tissue formation and calcification employing rat abdominal aorta interposition model and vascular grafts with 1.5 mm diameter with incorporated vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), and stromal cell-derived factor (SDF)-1α. Methods Tubular grafts with a diameter of 1.5 mm were blended of poly(3-hydroxybutyrateco-3-hydroxyvalerate) and poly(ε-caprolactone) (PHBV/PCL). Grafts without growth factors were fabricated using standard electrospinning technique whilst grafts with incorporated growth factors were prepared utilizing emulsion electrospinning. VEGF was incorporated into the inner third, whereas bFGF and SDF-1α were incorporated into the outer two-thirds of the graft. Grafts were implanted into the abdominal aortas of Wistar rats for 1, 3, 6, and 12 months following scanning electron microscopy along with histological and immunofluorescent examination. Results Primary patency of the grafts with VEGF, bFGF, and SDF-1α reached 93% indicative of structural integrity of the vascular tissue. Neither signs of inflammation nor severe calcification was detected. Conclusion As in 2 mm diameter vascular grafts, incorporation of bioactive factors into 1.5 mm diameter grafts increased their long-term primary patency and improved vascular tissue formation in comparison with non-modified grafts