Повышение кардиального тропонина-Т у больных без инфаркта миокарда

There have been recently reports on elevated levels of cardiac troponins in patients without acute myocardial infarction (AMI). The purpose of the study was to analyze final diagnoses in patients with elevated cardiac troponin-T levels without clinical manifestations and characteristic ECG changes in AMI. Subjects and materials. The study included 72 patients (48 males and 24 females whose age ranged from 54 to 87 years (mean 69.8±11.2 years)). The criterion for inclusion was increased cardiac troponin-T; the primary criteria for exclusion were AMI-specific anginal pains and characteristic ECG changes (ST-segment elevation, abnormal Q waves). The definitive diagnosis of AMI was established only in 29 (40.3%) patients; the remaining 43 patients were diagnosed as having the following diseases: sepsis (n=21), cancer (n=10), diabetic nephropathy with chronic renal failure (n=6), cerebral infarction (n=4), and B12-deficiency anemia (n=2). In deceased patients, the level of troponin-T was higher than that in those who was discharged from hospital irrespective of the underlying disease. Results. There was a direct correlation between the level of cardiac troponin-T and the SAPS II index that reflects the general condition of a patient (r=0.44; p=0.0001) and an inverse correlation between the former and the left ventricular ejection fraction (r=-0.45; p=0.003). Conclusion. Thus, despite its cardiac specificity and its detection in the blood of critically ill patients without other manifestations of AMI, cardiac troponin-T is not a specific symptom of AMI, but suggests the severity of the disease, possibly, with the involvement of the myocardium in the pathological process. Key words: cardiac troponins, myocardial infarction, multiple organ dysfunction, systemic inflammatory reaction.В настоящее время появляются сообщения о повышении уровня кардиальных тропонинов у больных без острого инфаркта миокарда (ОИМ). Цель настоящего исследования — анализ заключительных диагнозов у больных с повышением уровня кардиального тропонина-T без клинической картины и характерных изменений ЭКГ при ОИМ. Материал и методы. В исследование было включено 72 больных (48 мужчин, 24 — женщин, в возрасте от 54 до 87 лет, в среднем — 69,8±11,2). Критерием включения было повышение кардиального тропонина-Т, основными критериями исключения были — типичные для ОИМ ангинозные боли и характерные изменения ЭКГ (элевация сегмента ST, появление патологических зубцов Q). Окончательный диагноз ОИМ был установлен только у 29 больных (40,3%), у остальных 43-х больных были диагностированы следующие заболевания: у 21 — септическое состояние, у 10 — онкопатология, у 6 — диабетическая нефропа-тия с ХПН, у 4-х — инфаркт головного мозга, у 2-х — В12-дефицитная анемия. У умерших больных уровень тропонина-Т был достоверно выше, чем у выписанных из стационара, независимо от основного заболевания. Результаты. Была выявлена прямая корреляционная связь между уровнем кардиального тропонина-Т и индексом SAPS II, отражающим тяжесть общего состояния больного (r=0,44, р=0,0001) и обратная корреляционная связь между уровнем кардиального тро-понина и фракцией выброса левого желудочка (r=-0,45 р=0,003). Заключение. Таким образом, несмотря на кардиоспецифичность тропонина-Т, обнаружение его в крови пациентов, находящихся в крайне тяжелом состоянии, при отсутствии других проявлений ОИМ, не является специфическим симптомом ОИМ, а свидетельствует о тяжести заболевания, возможно с вовлечением миокарда в патологический процесс. Ключевые слова: кардиальные тропонины, инфаркт миокарда, полиорганная недостаточность, системная воспалительная реакция

Prevention and Mitigation of Acute Radiation Syndrome in Mice by Synthetic Lipopeptide Agonists of Toll-Like Receptor 2 (TLR2)

Bacterial lipoproteins (BLP) induce innate immune responses in mammals by activating heterodimeric receptor complexes containing Toll-like receptor 2 (TLR2). TLR2 signaling results in nuclear factor-kappaB (NF-κB)-dependent upregulation of anti-apoptotic factors, anti-oxidants and cytokines, all of which have been implicated in radiation protection. Here we demonstrate that synthetic lipopeptides (sLP) that mimic the structure of naturally occurring mycoplasmal BLP significantly increase mouse survival following lethal total body irradiation (TBI) when administered between 48 hours before and 24 hours after irradiation. The TBI dose ranges against which sLP are effective indicate that sLP primarily impact the hematopoietic (HP) component of acute radiation syndrome. Indeed, sLP treatment accelerated recovery of bone marrow (BM) and spleen cellularity and ameliorated thrombocytopenia of irradiated mice. sLP did not improve survival of irradiated TLR2-knockout mice, confirming that sLP-mediated radioprotection requires TLR2. However, sLP was radioprotective in chimeric mice containing TLR2-null BM on a wild type background, indicating that radioprotection of the HP system by sLP is, at least in part, indirect and initiated in non-BM cells. sLP injection resulted in strong transient induction of multiple cytokines with known roles in hematopoiesis, including granulocyte colony-stimulating factor (G-CSF), keratinocyte chemoattractant (KC) and interleukin-6 (IL-6). sLP-induced cytokines, particularly G-CSF, are likely mediators of the radioprotective/mitigative activity of sLP. This study illustrates the strong potential of LP-based TLR2 agonists for anti-radiation prophylaxis and therapy in defense and medical scenarios

Drivers of treeline shift in different European mountains

A growing body of evidence suggests that processes of upward treeline expansion and shifts in vegetation zones may occur in response to climate change. However, such shifts can be limited by a variety of non-climatic factors, such as nutrient availability, soil conditions, landscape fragmentation and some species-specific traits. Many changes in species distributions have been observed, although no evidence of complete community replacement has been registered yet. Climatic signals are often confounded with the effects of human activity, for example, forest encroachment at the treeline owing to the coupled effect of climate change and highland pasture abandonment. Data on the treeline ecotone, barriers to the expected treeline or dominant tree species shifts due to climate and land use change, and their possible impacts on biodiversity in 11 mountain areas of interest, from Italy to Norway and from Spain to Bulgaria, are reported. We investigated the role of environmental conditions on treeline ecotone features with a focus on treeline shift. The results showed that treeline altitude and the altitudinal width of the treeline ecotone, as well as the significance of climatic and soil parameters as barriers against tree species shift, significantly decreased with increasing latitude. However, the largest part of the commonly observed variability in mountain vegetation near the treeline in Europe seems to be caused by geomorphological, geological, pedological and microclimatic variability in combination with different land use history and present socio-economic relation Vegetation zone shift · Climate change · Climate models · Treeline ecotone · European mountains · Ecosystem service