Цель работы - изучение структурных особенностей эндотелия, микрососудистого русла, интерстициальных клеток створок митрального клапана при инфекционном эндокардите (ИЭ) и оценка их роли в развитии патологического процесса. Методика. Исследовано 14 митральных клапанов, извлеченных при хирургических вмешательствах у пациентов с инфекционным эндокардитом (ИЭ). Образцы фиксировали в забуференном параформальдегиде с постфиксацией в тетраокиси осмия. После обезвоживания в спиртах возрастающей концентрации и ацетоне образцы помещали в эпоксидную смолу. После полимеризации смолы образцы шлифовали, а затем полировали до нужной глубины образца. Для повышения электронного контраста образцы обрабатывали спиртовым раствором уранилацетата в процессе обезвоживания и цитратом свинца по Рейнольдсу после полировки эпоксидных блоков. Образцы визуализировали посредством сканирующей электронной микроскопии с детекцией обратно рассеянных электронов при ускоряющем напряжении 15 кВ. Результаты. На поверхности створок были выявлены структурные изменения эндотелиальных клеток, степень изменений зависела от состояния находящихся под ними участков створок. Минимальные изменения структуры наблюдали при максимальной сохранности структуры, максимальные вблизи зон некрозов и других типовых проявлениях ИЭ. Одновременно со структурными изменениями эндотелия отмечали активацию интерстициальных клеток, которые, по мере развития патологического процесса, мигрировали в направлении эндотелия, образуя параллельный ему слой клеток. В сосудах микроциркуляторного русла обращал внимание полиморфизм эндотелиоцитов, отмечался диапедез с миграцией гранулоцитов в толщу створок. В пораженных участках створок выявлялись признаки неоангиогенеза. Заключение. Полученные результаты указывают на комплекс изменений направленных на поддержание структурной целостности эндотелия и самих створок в целом. Конечным результатом этих процессов является замещение поврежденных клеток эндотелия интерстициальными клетками и активизация неоангиогенеза в толще створок. Aim. To investigate the structural features of endothelial cells of the surface layer of the mitral valve leaflet and microvascular bed, as well as interstitial cells in infective endocarditis (IE) of the mitral valve leaflets and to discuss their role in the development of the pathological process. Methods. We examined 14 mitral valves extracted during surgical interventions for structural incompetence due to IE. The samples were fixed in buffered paraformaldehyde with post-fixation in osmium tetroxide. After dehydration in alcohols of increasing concentration and acetone, the samples were placed in epoxy resin. After resin polymerization, the specimens were ground and then polished to the desired specimen depth. To increase the electronic contrast, the samples were treated with an alcohol solution of uranyl acetate during dehydration and with lead citrate, according to Reynolds method, after polishing the epoxy blocks. The samples were visualized by scanning electron microscopy with detection of backscattered electrons at an accelerating voltage of 15 kV. Results. Structural changes in endothelial cells were evident on the surface of the valves. The degree of these changes depended on the state of the underlying valve structure. Minimal changes in endothelial structure were associated with the maximal structural preservation of the leaflet. The maximal changes in endothelial structure were near the zones of leaflet necrosis and other serious manifestations of IE. Simultaneously with structural disorders of the endothelium, activation of interstitial cells was noted. As the pathological process progressed, these cells migrated towards the endothelium, and formed a layer of cells parallel to it. In microcirculatory vessels, endothelial cell polymorphism was also observed. In these vessels, diapedesis with migration of granulocytes into the valves was noted. Neoangiogenesis in the affected areas of the valves was noted. Conclusion. The results showed processes in the cusps of mitral valves with IE that aim to maintain the structural integrity of the endothelium and of the cusps. The end result of these processes is the replacement of damaged endothelial cells with interstitial cells and activation of neoangiogenesis in the thickness of the cusps.
Введение. Кальций-фосфатные бионы (КФБ) формируются в организме человека при перенасыщении сыворотки ионами кальция и фосфора и вызывают дисфункцию эндотелия, однако молекулярные механизмы нарушения функционирования эндотелия при воздействии КФБ не ясны. Цель исследования - выяснение роли кальций-фосфатных бионов различной формы в развитии окислительного стресса в артериальных эндотелиальных клетках (ЭК) человека. Методика. Для детекции окислительного стресса к конфлюэнтным культурам первичных ЭК коронарной и внутренней грудной артерии человека добавляли равные концентрации КФБ сферической или игольчатой формы (СКФБ и ИКФБ соответственно) с последующим культивированием в течение 1 и 4 ч, добавлением флюоресцентных индикаторов окислительного стресса MitoSOX Red и CellROX Green и конфокальной микроскопией. Измеряли концентрацию продуктов перекисного окисления липидов в культуральной жидкости через 24 ч экспозиции эндотелиальных клеток КФБ. Анализ нейтрализации цитотоксических эффектов перекисного окисления липидов проводили путем добавления к ЭК супероксиддисмутазы и каталазы на 4 или 24 ч (одновременно с КФБ). Для сравнения механизмов клеточной гибели при воздействии СКФБ и ИКФБ анализировали цитотоксичность обоих типов бионов при одновременном воздействии лизосомального ингибитора бафиломицина А1. Результаты. Значимого увеличения генерации активных форм кислорода (АФК) в результате экспозиции СКФБ (независимо от линии ЭК и продолжительности экспозиции) не было выявлено. В то же время наблюдалось повышение генерации супероксида через 4 ч, а иных свободных радикалов через 1 ч после добавления ИКФБ к ЭК. Предварительная нейтрализация АФК супероксиддисмутазой и каталазой частично защищала ЭК от индуцируемой ИКФБ гибели. При этом добавление бафиломицина А1 к ЭК частично защищало их от гибели только при воздействии СКФБ, но не ИКФБ. Заключение. Гибель ЭК при воздействии СКФБ происходит в результате первичного повреждения лизосом, а при воздействии ИКФБ - в первую очередь вследствие окислительного стресса. Background. Calcium phosphate bions (CPB) form in the human blood upon its supersaturation with calcium and phosphate and provoke endothelial dysfunction; however, the molecular mechanisms of these pathological processes remain unclear. Aim. To elucidate the role of differently shaped CPBs in induction of oxidative stress in human arterial endothelial cells (Ecs). Methods. For detection of oxidative stress, equal concentrations of spherical CPB (CPB-S) or needle-shaped CPB (CPB-N) were added to confluent cultures of primary human coronary artery and internal thoracic artery ECs for 1 and 4 h; this was followed by MitoSOX Red and CellROX Green staining and subsequent confocal microscopy. Concentration of thiobarbituric acid-reactive substances was measured in the EC culture supernatant at 24 h of the CPB exposure. The lipid peroxidation cytotoxicity was neutralized by adding superoxide dismutase and catalase to ECs for 4 or 24 h. To compare cell death subroutines induced by CPB-S and CPB-N, the effect of bafilomycin A1, a lysosomal inhibitor, on CRB cytotoxicity was studied. Results. No increase in reactive oxygen species generation was observed in the CPB-S exposure, regardless of the EC line and exposure duration. However, addition of CPB-N to ECs increased the production of superoxide and other free radicals after four- and one-hour exposure, respectively. Prior neutralization of reactive oxygen species with superoxide dismutase and catalase partially protected ECs from CPB-N- but not CPB-S-induced death while bafilomycin A1, vice versa, protected ECs from CPB-S- but not CPB-N-induced death. Conclusion. CPB-S cause cell death due to primary damage of lysosomes whereas CPB-N induce apoptosis due to oxidative stress.
AIM This study was undertaken to investigate the preoperative incidence and severity of intimal hypertrophy, as well as the level of blood supply of arterial and venous conduits for coronary artery bypass grafting. MATERIAL AND METHODS Segments of the internal thoracic artery and great saphenous vein (n=13) were harvested pairwise during coronary artery bypass grafting and were then visualized by scanning electron microscopy in back-scattered electrons. The analysis of the incidence and thickness of intimal hypertrophy, as well as the calculation of the number and the area of the vasa vasorum were performed using the programme ImageJ. RESULTS Intimal hypertrophy was more characteristic for the great saphenous vein as compared with the internal thoracic artery (9/13 (69.2%) and 7/13 (55.8%), respectively), although this difference did not reach statistical significance. The maximal-to-minimal neointimal thickness ratio correlated with the percentage of stenosis (r=0.875, p<0.0001), the area (r=0.45, p=0.023) and the number (r=0.47, p=0.015) of the vasa vasorum in the conduits, thus confirming the hypothesis on possible participation of these vessels in the development of intimal hypertrophy, with the area of the vasa vasorum being greater in the vessels with >10% stenosis (p=0.051). The number of the vasa vasorum in the great saphenous vein exceeded that in the internal thoracic artery (p=0.0005), with this difference remaining significant after adjustment for the area of the adventitia (p=0.027). The number of the vasa vasorum per the percentage of stenosis in the great saphenous vein also exceeded that in the internal thoracic artery (p=0.039) and more strongly correlated with intimal hypertrophy in the great saphenous vein as compared with that in the internal thoracic artery (r=0.53 and r=0.27, respectively). CONCLUSION Intimal hypertrophy correlates with the area and number of the vasa vasorum in conduits. The great saphenous vein is characterised by a larger number and higher density of the vasa vasorum as compared with the internal thoracic artery. The number of the vasa vasorum is correlated with stenosis of the great saphenous vein more closely than with stenosis of the internal thoracic artery. This may be suggestive of significant predisposition of the great saphenous vein to the onset of adventitial inflammation followed by the development of intimal hypertrophy.
Aim of the study was to identify the mechanism of specific endothelial toxicity related to calcium phosphate bions (CPB). Material and methods . CPB and magnesium phosphate bions (MPB) were artificially synthesised through supersaturation of culture medium with respective salts and then added to human endothelial cells (EA.hy 926) and murine endothelial cells (2H-11) to study: 1) spatiotemporal aspects of bion internalisation by means of transmission electron microscopy and confocal microscopy; 2) whether blocking of H+-ATPase by lysosomal inhibitor bafilomycin A1 affects endothelial toxicity of bions; 3) expression of caspase-3 and its substrate poly(ADP-ribose) polymerase (PARP-1). Results . CPB were internalized by endothelial cells as early as 1 h upon their addition and were localized in lysosomes; after 4 h, we detected release of calcium ions (Ca2+) from lysosomes to cytosol accompanied by multifold increase in cleaved caspase 3 and its substrate PARP-1. Bafilomycin A1 rescued endothelial cells from death induced by slightly soluble CPB regardless of exposure time and dose; however, freely soluble MPB did not evince endothelial toxicity regardless of bafilomycin A1 addition. Conclusion . Upon internalization by endothelial cells, CPB cause their death due to dissolution in lysosomes and subsequent release of calcium ions into the cytosol, ultimately leading to cleavage of executioner caspases. MPB lack endothelial toxicity because their dissolution does not lead to release of calcium ions. Therefore, specific endothelial toxicity of CPB is defined by lysosome-dependent cell death.
Aim of the study was to identify the mechanism of specific endothelial toxicity related to calcium phosphate bions (CPB). Material and methods . CPB and magnesium phosphate bions (MPB) were artificially synthesised through supersaturation of culture medium with respective salts and then added to human endothelial cells (EA.hy 926) and murine endothelial cells (2H-11) to study: 1) spatiotemporal aspects of bion internalisation by means of transmission electron microscopy and confocal microscopy; 2) whether blocking of H+-ATPase by lysosomal inhibitor bafilomycin A1 affects endothelial toxicity of bions; 3) expression of caspase-3 and its substrate poly(ADP-ribose) polymerase (PARP-1). Results . CPB were internalized by endothelial cells as early as 1 h upon their addition and were localized in lysosomes; after 4 h, we detected release of calcium ions (Ca2+) from lysosomes to cytosol accompanied by multifold increase in cleaved caspase 3 and its substrate PARP-1. Bafilomycin A1 rescued endothelial cells from death induced by slightly soluble CPB regardless of exposure time and dose; however, freely soluble MPB did not evince endothelial toxicity regardless of bafilomycin A1 addition. Conclusion . Upon internalization by endothelial cells, CPB cause their death due to dissolution in lysosomes and subsequent release of calcium ions into the cytosol, ultimately leading to cleavage of executioner caspases. MPB lack endothelial toxicity because their dissolution does not lead to release of calcium ions. Therefore, specific endothelial toxicity of CPB is defined by lysosome-dependent cell death.
В данной работе освещена методика синтеза однослойных углеродных нанотрубок и формирования функционально активного комплекса с антиоксидантными свойствами на основе иммобилизации супероксиддисмутазы на их поверхности. Спектрофотометрический анализ продемонстрировал, что увеличение добавляемой концентрации данного комплекса ускоряло торможение образования адренохрома. Это свидетельствовало об успешной иммобилизации фермента и функциональной активности комплекса, который может применяться в наномедицине с целью доставки активной супероксиддисмутазы в ткани и клетки.
The aim of the study was to evaluate the efficacy of lecithin/cholesterol liposomes in the therapy of experimental venous congestion-induced chronic liver insufficiency. The effects of the empty liposomes, ATP and phosphocreatine-containing liposomes and alpha-tocopherol and superoxide dismutase-containing liposomes were studied. It was found that liposomal drugs have a hepatoprotective effect, i.e. they decrease blood enzyme activity (cytolysis markers), reduce oxidative stress and preserve histologic integrity of the liver.
В работе исследовано влияние перфоторана в свободной и липосомальной формах на активность различных стадий перекисного окисления липидов. Показано, что при введении перфторана, пустых липосом и липосомальной формы перфторана животным, с моделированным хроническим панкреатитом, наблюдали снижение проявлений окислительного стресса. Различные препараты отличались по степени торможения и накопления первичных и вторичных продуктов липопероксидации и влиянию на активность ферментов антиоксидантной защиты. Наилучшим протективным действием обладали пустые липосомы и лисомальный перфторан. Липосомальная форма перфторана, в отличие от пустых липосом, не только увеличивала суммарную антиоксидантную активность, но и активизировала собственные антиоксидантые ферменты крови и тканей. Высокая эффективность липосомальных композиций в отношении снижения проявлений окислительного стресса, показывает перспективность исследований направленных на создание на их базе высокоэффективных фармакологических препаратов для терапии панкреатита.
Aim. To assess the toxicity of calcium-phosphate bions (CPB) for epithelium in vitro and in vivo . Materials and methods. Artificial CPB synthesis, standard methods for cell culturing, phase-contrast microscopy, transmission electronic microscopy, annexin-V/7-aminoactinomycin D-test, 3-(4,5-dimethylthiazol-2-il)-2,5-diphenyltetrazolium bromide (MTT-test), immune-enzyme assay, original experimental model of rat aortal angioplasty using balloons for coronary angioplasty, hematoxylin-eosin stain and Van Gieson’s stain, histological analysis, statistical analysis were used. Results. CPB were internalized by endothelial cells of the EA.hy 926 line. The share of cells exposed to late apoptosis/necrosis was significantly higher, whereas, the share of bioplasts was significantly lower in the cultures of CPB-exposed cells as compared to the control cultures; no dose-dependence was revealed. The levels of interleukin-6 and interleukin-8 were significantly higher in the supernatant from CPB-exposed cells versus the control cultures. There was also observed a significant hyperplasia of intima in 3 CPB- exposed rats, but not in the controls. The intima to media ratio in the abdominal aorta wall was also significantly higher in CPB-exposed rates in comparison with the control rats. Conclusions. Calcium-phosphate bions have a toxic effect on endothelial cells.
Проведен анализ эффективности применения сосудисто-эндотелиального фактора роста (VEGF) для стимуляции ангиогенеза в постинфарктном миокарде. Использовали сосудисто-эндотелиальный фактор роста в различной дозировке (2,5; 12,5 нг) в свободной форме и в составе липосом. Эффективность доставки препарата к миокарду и стимуляции ангиогенеза оценивали на основании анализа экспрессии VEGF и плотности сосудистой сети в миокарде. Показано, что введение препаратов VEGF сопровождается увеличением его экспрессии в миокарде. Однако только при введении липосомальной формы VEGF в более высокой дозировке (12,5 нг) достигали непрерывного повышенного содержания ростового фактора в течение длительного времени (до 7 суток). Это сопровождалось значительным увеличением плотности сосудистой сети. Меньшая концентрация VEGF в составе липосом и ростовой фактор в свободной форме не оказывали выраженного действия.
This publishing is the particular matter to help for a performance of perfusion of the isolated heart by Langendorff and Neely methods. The publishing represents and describes the fundamental plan of an installation for the perfusion of the isolated heart by these methods, determines a specific succession of action while executing a perfusion (by current experience of these authors) and explores possibilities of using the model of perfusion of the isolated heart in the scientific research.
In the experiments on the isolated perfused rat heart we studied the effects of liposomes containing different concentrations (0.25 and 0.1 mg/ml) of emoxipine on coronary flow, contractive and pump function of the isolated heart, which was effected by total normothermical ischemia and reperfusion. The parameters of the contractile activity of hearts, coronary flow and pump function of the hearts were assessed. It was detected that the introduction of the liposomal emoxipine during ischemia provides a protective effect against ischemic and reperfusion myocardial damage and smaller concentration of the emoxipin (0.1 mg/ml) in composition with the liposomes promote the best recovery of contractile activity and the pumping function of the ischemic heart in the period of the reperfusion.