Механизмы кардиотоксического действия амитриптилина

Objective: to study the mechanisms of toxic action of amitriptyline on the myocardium. Material and methods. Investigations were conducted using the hearts from 30 outbred albino rats, which had been isolated and perfused according to the procedure described by Fallen et al. There were two series of experiments: 1) amitriptyline was added in a dose of 250 ng/ml to Krebs-Henseleit solution (Group 1); 2) the agent was added at another concentration (1250 ng/ml) to the solution passing through the coronary bed (Group 2). The animals were anesthetized with thiopental sodium (25 mg/kg) peritoneally. Results. Amitriptyline depresses myocardial contractility, which is particularly obvious with high-rate pacing. This manifests itself as reduced contractile velocity and force-power parameters and elevated left ventricular diastolic pressure. Amitriptyline lowers the efficacy of glucose and increases the release of enzymes into the coronary duct. Conclusion. Hypoergosis, membrane destruction, and cardiomyocyte ion pump failure have been shown to underlie negative chronotropic and inotropic effects in amitriptyline poisoning. Key words: amitriptyline, acute poisoning, isolated heart, myocardial damage.Цель исследования — изучить механизмы токсического действия амитриптилина на миокард. Материал и методы. Исследования проведены на изолированных, перфузируемых по методу Fallen et al. сердцах 30 белых беспородных крыс. Выполнено две серии экспериментов: в одной серии в раствор Кребса-Хензелайта был добавлен амитриптилин в дозе 250 нг/мл (I группа), в другой концентрация амитриптилина в растворе, проходившем через коронарное русло, составила 1250 нг/мл (II группа). Животных наркотизировали тиопенталом натрия (25 мг/кг внутрибрюшинно). Результаты. Амитриптилин угнетает сократительную функцию миокарда, что особенно отчетливо выражается при навязывании ритма высокой частоты. Это проявляется снижением скоростных и силовых показателей сократимости и ростом диастолического давления в левом желудочке. Амитриптилин снижает эффективность использования глюкозы и увеличивает выделение ферментов в коронарный проток. Заключение. Показано, что в основе отрицательного хроно-инотропного эффекта при отравлении амитриптилином лежит гипоергоз, мембранодеструкция и недостаточность ионных насосов кардиомиоцитов. Ключевые слова: амитриптилин, острое отравление, изолированное сердце, повреждение миокарда

Traveling through potential energy landscapes of disordered materials: the activation-relaxation technique

A detailed description of the activation-relaxation technique (ART) is presented. This method defines events in the configurational energy landscape of disordered materials, such as a-Si, glasses and polymers, in a two-step process: first, a configuration is activated from a local minimum to a nearby saddle-point; next, the configuration is relaxed to a new minimum; this allows for jumps over energy barriers much higher than what can be reached with standard techniques. Such events can serve as basic steps in equilibrium and kinetic Monte Carlo schemes.Comment: 7 pages, 2 postscript figure

Effect of Secondary Echo Signals in Spin-Systems with a Large Inhomogeneous Broadening of NMR Line

The possibility of comparatively simple and fast determination of characteristic relaxation parameters T1, T2 and T3 for nuclear spin-systems with strong Larmor and Rabi inhomogeneous broadenings of NMR lines using the secondary echo signal effect was experimentally shown. Resides, this method gives opportunity to obtain a valuable infomation on the inhomogeneous NMR broadening which reflects the character of magnetic field microscopic destribution in such systems, as example, multidomain magnetics and superconductors.Comment: 12 pages, 5 figure

Social and economic coast of suicides poisons in the Sverdlovsk Region the study period 2002-2008

The social cost of premature death relating to suicides poisons in the Sverdlovsk Region was 647 peoples for the study period 2002-2008. The economic cost of premature death relating to suicides poisons was 736,0 million rubles. The limitations of this study should be recognized when applying to its findings. Therefore they should be treated as approximations.Экономическая составляющая ущерба, обусловленного преждевременной смертностью от острых суицидальных отравлений рассчитывается исходя из соотношения количества недожитых человеко-лет с долей валового регионального продукта, приходящегося на одного жителя области (подушевой валовой региональный продукт). В работе представлены результаты расчетов экономического ущерба Свердловской области в связи с преждевременной смертностью от суицидальных отравлений. В результате расчетов, проведенных авторами данной работы было определено, что за семь лет в Свердловской области погибло от суицидальных отравлений погибло 647 пациентов, (социальный ущерб). Экономические потери региона в результате преждевременной смерти дотрудоспособного и трудоспособного населения от суицидальных отравлений за 2002-2008гг. составил 736 млн. рублей (экономический ущерб). Естественно, что при использовании полученных данных, необходимо иметь в виду определенные ограничения, которые существуют в данном исследовании. В связи с этим, полученные данные следует рассматривать как приблизительные

Analysis of acute poisonings in the region in the periods between 1996-2006

The aim is the study epidemiology of acute poisonings in the period between 1996 -2006 years. All cases of acute poisonings we analysed accodinig to the centre of Hygiene and epidemiology of Sverdlovsk region. The problems of epidemiology sitiuation of acute poisonings in Sverdlovsk region were discovered.Целью работы явилось изучение эпидемиологической ситуации в Свердловской области в период 1996 по 2006 г. Исследование построено на данных анализа экстренных извещений на каждый случай отравления с последующей компьютерной обработкой материала (токсикологический мониториг). Данные эпидемиологического анализа свидетельствуют о не благополучной ситуации в Свердловской области

Two-pulse stimulated echo in magnets

The results of experimental study of two-pulse stimulated echo in ferromagnets of two types are presented. Ferromagnet Co and half-metal Co MnSi 2, in which a single-pulse echo formed by the distortion mechanism of the fronts of exciting pulse is also observed, are classified among the first type. Lithium ferrite and intermetal compound MnSb characterized by the absence of single-pulse echo in them - belong to the second type. For signals of two-pulse stimulated echo in the materials of the first type a short time and a long time of relaxations are observed. The short time is about the order of value shorter less than the spin-spin relaxation time. The long time is close to the transverse relaxation time of single-pulse echo formed by the distortion mechanism. The mechanisms that provide the possible interpretations of the peculiarities of the processes of nuclear magnetic relaxation are discussed.Comment: 10 pages, 7 figure

Application of 3D Zernike descriptors to shape-based ligand similarity searching

Background: The identification of promising drug leads from a large database of compounds is an important step in the preliminary stages of drug design. Although shape is known to play a key role in the molecular recognition process, its application to virtual screening poses significant hurdles both in terms of the encoding scheme and speed. Results: In this study, we have examined the efficacy of the alignment independent three-dimensional Zernike descriptor (3DZD) for fast shape based similarity searching. Performance of this approach was compared with several other methods including the statistical moments based ultrafast shape recognition scheme (USR) and SIMCOMP, a graph matching algorithm that compares atom environments. Three benchmark datasets are used to thoroughly test the methods in terms of their ability for molecular classification, retrieval rate, and performance under the situation that simulates actual virtual screening tasks over a large pharmaceutical database. The 3DZD performed better than or comparable to the other methods examined, depending on the datasets and evaluation metrics used. Reasons for the success and the failure of the shape based methods for specific cases are investigated. Based on the results for the three datasets, general conclusions are drawn with regard to their efficiency and applicability

TERMS OF WINTER WHEAT TREATMENT BY FUNGICIDES TO CONTROL DEVELOPMENT OF BROWN RUST PATHOGEN

The terms of winter wheat treatment against brown rust pathogens (PucciniareconditeRob. exDesmf. sp. tritici) can greatly differ depending on climatic conditions and applied materials. The question is not studied enough for the Tambov region. In the production brown rust control fungicides are often used at the early periods of plant development (tillering, stem-extension stage). It makes the second treatment necessary as the preparation effect finishes at the maximum manifestation of disease (plant development phase-milky ripeness of kernels). In the Tambov region, the first pustules of brown rust appear on winter wheat plants in the beginning of the earing phase. This period occurs at the end of May/beginning of June. It is logical to assume that the maximum suppression of the disease on wheat will be achieved by spraying precisely at these times. To test this assumption, the field trials were conducted using the preparations ‘Reks duo’ and ‘Abakus’. They were used in the stem-extension stage and earing phase of winter wheat. Biological efficiency of fungicide spraying in earing phase of wheat was significantly larger (98.2–98.8%). Application of fungicides spraying in stem-extension stage was 85.6-86.5%. The amount of the saved yield was 0.60–0.81 t/ha (14.2–19.1%). Maximum values of winter wheat productivity (5.05 t/ha) was obtained when the preparation ‘Abakus’ was applied in earing phase. Wheat treatment by the preparations ‘Reks duo’ and ‘Abakus’ in earing phase was found more economically profitable, and the level of profitability was 130.9 and 55.0%, in stem-extension stage it was 109.2 and 35.4% respectively. The results of the trials showed that fungicides spraying in earing phase is the most optimal

Biological assessment of fungicides in vitro

During the testing of plant protection methods on the fields we need a longer period of time, large expenditure of material and labor. It’s not always possible to evaluate the efficiency of chemical drugs to one definite type of pathogen. On the naturally infected fields the plants are infected by some kinds of fungi, that produce the same symptoms of the disease. Thus it is essential to study the efficiency of fungicides to some kinds of phyto pathogens in the artificial conditions or to use laboratory methods with the application of pure cultures of fungi. One of these methods is Plate Count Agar (PCA) (also called Standard Methods Agar (SMA)). It has been established that this method can be used for biological assessment of fungicides (in vitro) for the fungi Fusarium, and also for other species which grow in the artificial conditions. The method consists in the following: in the experimental variants, a suspension of conidia of the fungus and a solution of the chemical drug are applied to the agar plate, in the control variant sterile water is applied instead of the fungicide. After the process of incubation in the thermostat, a number of formed fungal colonies and their diameter are assessed. The application of Plate Count Agar (PCA) (also called Standard Methods Agar (SMA)) gave the opportunity to reveal the most efficient (92.2-100.0%) for the fungi Fusarium semitectum, F. tricinctum and Bipolaris sorokiniana chemical drugs ‘Kinto Duo’, ‘Vitaros’, ‘Vintsit’, ‘Maksim’, ‘Vial TT’ and ‘Maksim ekstrim’. The fungicides ‘Kolfugo super’ and ‘Falkon’ showed their largest inhibitory effect (with the efficiency of 97.3-98.6%) for the fungus Fusarium graminearum