ИЗУЧЕНИЕ КАРДИОТОКСИЧНОСТИ ПРОДУКТОВ ГИДРОЛИТИЧЕСКОЙ ДЕГРАДАЦИИ ТРУБЧАТЫХ ПОЛИМЕРНЫХ МАТРИКСОВ, ПРИГОДНЫХ ВЫСТУПИТЬ В КАЧЕСТВЕ СОСУДИСТОГО ИМПЛАНТА МАЛОГО ДИАМЕТРА

The evaluation of cardiotoxicity of the degradation products of electrospunpolyhydroxybutyrate-valerate and polycaprolactone tubular matrices, subjected to 6-month hydrolytic degradation in sterile phosphate buffered saline (PBS) at 37 ºC, was performed. After matrices incubation in PBS, high performance liquid chromatography was used to analyze individual analytes for the presence of monomers and other compounds each month. Cardiotoxicity of analytes was evaluated in a model of isolated perfused rat heart (male Wistar rats) using the Langendorff technique. The rate of coronary flow and enzymatic activity of creatine phosphokinase and lactate dehydrogenase myocardial fractions were measured during the analytes injections. Both, polyhydroxybutyrate-valerate and polycaprolactone, had no significant signs of hydrolytic degradation of polymers into monomers after 6-month storage time. PBS after 6-month incubation of the studied samples did not produce any cardiotoxic effect in the experiments on isolated rat heart and did not demonstrate any significant increase of enzyme activity in the perfusate.Проведен анализ кардиотоксичности продуктов деградации полимеров полигидроксибутирата/валерата и поликапролактона, явившихся основой для изготовления трубчатого каркаса методом электроспиннинга и подвергнутых 6-месячной гидролитической деградации в стерильном фосфатно-солевом буфере при температуре 37 ºС. Исследование состава аналитов на наличие мономеров и прочих соединений после инкубации матриксов в буфере проводили ежемесячно с помощью жидкостной хроматографии. Кардиотоксичность аналитов оценивали на модели изолированного сердца крыс-самцов линии Wistar методом Langendorff. На фоне введения аналитов измеряли скорость коронарного протока и изучали ферментативную активность миокардиальной фракции креатинфосфокиназы и лактатдегидрогиназы. Полигидроксибутират/валерат и поликапролактон не имели достоверных признаков распада до мономеров через 6 месяцев гидролитической деградации, а фосфатно-солевой буфер, в котором инкубировали данные образцы в течение 6 месяцев, не вызывал кардиотоксического эффекта в экспериментах на модели изолированного сердца и достоверного повышения активности ферментов в перфузате

Polar tree line beyond todays Arctic Siberian mainland coast during the last Interglacial: the paleontological evidence

Remains of fossil organisms, including plants, insects (beetles, chironomids), ostracods and gastropods, preserved in frozen deposits of a shallow paleo-lake indicate boreal climate at todays Arctic mainland coast of Oyogos Yar, Yakutia during the last interglacial about 125.000 years BP. Terrestrial beetle and plant remains prove the former existence of open forest tundra with Dahurian larch (Larix dahurica), grey alder (Alnus incana) and boreal shrubs (Duschekia fruticosa, Betula fruticosa, B. divaricata, B. nana) interspersed with patches of steppes and meadows. Consequently, the tree line was shifted northward up to todays mainland coast, and probably beyond, thus at least 270 km off its current position. Low net precipitation is shown by steppe plants and beetles. Aquatic organisms such as chironomids, ostracods, gastropods and hydrophytes indicate lake formation as result of thermokarst processes. Many of the lacustrine organisms are very warmth sensitive indicating a mean temperature of the warmest month near 13 °C, which is above the minimum requirement of tree growth and in contrast to modern values of less than 4 °C (Voeikov Main Geophysical Observatory, 1980). Littoral pioneer plants and chironomids indicate intense lake level fluctuations due to high evaporation. The results suggest that modern Arctic tundra, lacking woody plants and bound to constantly wet ground under cool and moist summer conditions, did obviously not exist in Arctic Siberia in warm stages prior to the Holocene

Multipotent Mesenchymal Stromal Cells for the Prophylaxis of Acute Graft-versus-Host Disease—A Phase II Study

The efficacy and the safety of the administration of multipotent mesenchymal stromal cells (MMSCs) for acute graft-versus-host disease (aGVHD) prophylaxis following allogeneic hematopoietic cell transplantation (HSCT) were studied. This prospective clinical trial was based on the random patient allocation to the following two groups receiving (1) standard GVHD prophylaxis and (2) standard GVHD prophylaxis combined with MMSCs infusion. Bone marrow MMSCs from hematopoietic stem cell donors were cultured and administered to the recipients at doses of 0.9–1.3×106/kg when the blood counts indicated recovery. aGVHD of stage II–IV developed in 38.9% and 5.3% of patients in group 1 and group 2, respectively, (=0.002). There were no differences in the graft rejection rates, chronic GVHD development, or infectious complications. Overall mortality was 16.7% for patients in group 1 and 5.3% for patients in group 2. The efficacy and the safety of MMSC administration for aGVHD prophylaxis were demonstrated in this study

Paleontological records indicate the occurrence of open woodlands in a dry inland climate at the present-day Arctic coast in western Beringia during the Last Interglacial

Permafrost records, accessible at outcrops along the coast of Oyogos Yar at the Dmitry Laptev Strait, NE-Siberia, provide unique insights into the environmental history of Western Beringia during the Last Interglacial. The remains of terrestrial and freshwater organisms, including plants, coleopterans, chironomids, cladocerans, ostracods and molluscs, have been preserved in the frozen deposits of a shallow paleo-lake and indicate a boreal climate at the present-day arctic mainland coast during the Last Interglacial. Terrestrial beetle and plant remains suggest the former existence of open forest-tundra with larch (Larix dahurica), tree alder (Alnus incana), birch and alder shrubs (Duschekia fruticosa, Betula fruticosa, Betula divaricata, Betula nana), interspersed with patches of steppe and meadows. Consequently, the tree line was shifted to at least 270 km north of its current position. Aquatic organisms, such as chironomids, cladocerans, ostracods, molluscs and hydrophytes, indicate the formation of a shallow lake as the result of thermokarst processes. Steppe plants and beetles suggest low net precipitation. Littoral pioneer plants and chironomids indicate intense lake level fluctuations due to high evaporation. Many of the organisms are thermophilous, indicating a mean air temperature of the warmest month that was greater than 13 °C, which is above the minimum requirements for tree growth. These temperatures are in contrast to the modern values of less than 4 °C in the study area. The terrestrial and freshwater organism remains were found at a coastal exposure that was only 3.5 m above sea level and in a position where they should have been under sea during the Last Interglacial when the global sea level was 6–10 m higher than the current levels. The results suggest that during the last warm stage, the site was inland, and its modern coastal situation is the result of tectonic subsidence