Toxigenic Cyanobacteria and Microcystins in a Large Northern Oligotrophic Lake Onego, Russia.

Toxigenic cyanobacteria and microcystins in the oligotrophic pelagic zone and mesotrophic bay of Lake Onego-the second largest lake in Europe-were found for the first time. Microscopic analysis revealed that and dominated in bloom spots in the oligotrophic zone of the lake and and OKin the eutrophic bay. The abundance of cyanobacteria in bloom spots is potentially hazardous for humans and animals.

Assessment of Microplastic Size Range and Ingestion Intensity by Gmelinoides fasciatus Stebbing, an Invasive Species of Lake Onego.

To indicate the potential role of Gmelinoides fasciatus, an invasive species of Lake Onego, in the inclusion of microplastics into food webs, several indicators were evaluated: its ability to ingest microplastics, the preferred size ranges, and the ingestion intensity. For this purpose, irregularly shaped polystyrene copolymer particles (acrylonitrile butadiene styrene plastics, artificially crushed) of four size classes (<50, 50-100, 100-250, >250 µm) were used. Gmelinoides fasciatus actively ingested microplastic particles, and in treatment with particles of 100-250 µm in size, the consumption rate was the highest.

[True polycythemia: current views of pathogenesis, diagnostics and treatment].

Current concepts of true polycythemia are reviewed. Results of numerous epidemiological studies on the prevalence of this form of myeloproliferative neoplasms are presented with special reference to recent findings concerning its pathogenesis and the role of JAK2V617F mutation that occurs in the majority of patients. The clinical picture and new diagnostic criteria are discussed The data on the incidence and prevalence of the disease and its complications are considered including venous and/or arterial thrombosis, transformation into post-polycythemic myelofibrosis and acute myeloleucosis.

[The role of T-wave alternans in prognosis of risk of sudden cardiac death].

The literature review contains data dedicated to one of tools of stratification of risk of fatal arrhythmia - detection of T-wave alternans (TWA). Methods of determination of TWA, problems of results interpretation, mechanism of the TWA genesis, and its clinical meaning in different cardiovascular diseases are considered. Special attention is paid to the role of TWA in the identification of the patients who require cardioverter-defibrillator implantation.

[Evolutionary conditioning of response to changes in ionic composition of water in hydrobionts: an example of freshwater zooplankton].

The situation in Karelian water bodies polluted with mining waste has been analyzed. As a result of technogenic wastewater discharge, the total ion content in lake waters has increased tens of times, and the concentration of potassium ions (the main component of wastewater), hundreds of times. Pollution tolerance of hydrobiont populations depends on the historically developed adaptation potential of species.

[Effect of propranolol in silent myocardial ischemia induced by anthracyclines].

Effect of propranolol on pain-free myocardial ischemia induced by exposure to anthracyclinic antibiotics were assessed by findings from Holter ECG monitoring in 36 patients with acute lymphoblast leukemia against the background of a complete clinical-and-hematological remission. In those patients having received small cumulative doses of anthracyclines (less than 550 mg/m2) in whom depression of ST-segment had an apparent tachydependent character the severity of pain-free ischemia was shown to be alleviated by a 3-week intake of propranolol. Remarkably, those patients with "silent" myocardial ischemia having received high cumulative doses of cytostatics (more than 550 mg/m2) did not derive much benefit from beta-adrenoblocker, which fact might be associated with the presence in this case of ischemic episodes unrelated to tachycardia.

[Causes of the technogenic changes in a freshwater zooplankton community].

The situation in water bodies of northwestern Karelia in 1992-2001 was analyzed. As a result of waste discharge from the mining and ore-processing works, weakly mineralized hydrocarbonate-calcium waters changed into highly mineralized waters with the prevalence of potassium ions and sulfates. The total abundance and biomass of zooplanktonic communities decreased.