129 research outputs found
Operational Management of Distributed Active Systems Based on the Cloud Approac
The paper deals with decision making in
operational management of distributed active systems.
The problem is associated with the necessity to consider a
sequence of poorly formalized decision making problems,
arising on the level of distributed system local modules. A
possibility of the problem solution based on cloud
technology and distributed innovation knowledge is
investigated
The Degree of Oxidative Stress in the Rat Brain During Ischemia and Reperfusion in Conditions of Correction of the L-Arginine-No System
brain, ischemia/reperfusion, oxidative stress, nitric oxide.The aim of the present work was to evaluate oxidative stress in the brains of rats during ischemia/reperfu-sion in conditions of correction of the L-arginine-NO system. Experiments on 128 rats with brain ischemia/perfusion in conditions of modulation of the L-arginine-NO system were used to study changes in the concentrations of (a) lipid peroxidation products, i.e., diene conjugates, malonic dialdehyde, and Schiff bases, and (b) antioxidant protection factors, i.e., retinol, a-tocopherol, and SH-groups. Administration of L-arginine and NO synthase inhibitors, i.e., the non-selective inhibitor Nm-nitro-L-argi-nine methyl ester, the selective neuronal NO synthase inhibitor 7-nitroindasole, and the selective inhibitor of inducible NO synthase S-methylisothiourea, established that oxidative stress in rats with brain ischemia/perfusion is NO-dependent. NO formed by the various isoforms of NO synthase had different roles: hyperactivation of neuronal NO synthase was responsible for oxidative stress in both periods of brain ischemia/reperfusion, while increased inducible NO synthase activity was responsible in the late period
Morphological features of parietal cortex and hippocampus neuron of rats following subtotal cerebral ischemia associated with omega-3 polyunsaturated fatty acids injection
Aim of the study was to investigate the morphological features of neurons of the parietal cortex and hippocampus of rats with subtotal cerebral ischemia (SACI) during administration of omega-3 polyunsaturated fatty acids (omega-3 PUFA). Materials and methods. The experiments were performed on 24 white outbred male rats. Surgical interventions were carried out under conditions of intravenous thiopental anesthesia (40–50 mg/kg). Acute SACI was modeled by bilateral ligation of the common carotid arteries. The animals of the main group (n = 6, SACI + omega-3 PUFA) received intragastric injections of omega-3 PUFA preparation at a dose of 5 mg/kg body weight prior to ischemia for a week. In the comparison group (n = 6, SACI), the drug was not used; the control (n = 6) was sham operated animals, which were incised without skin ligation. Animals were decapitated after 60 minutes of ischemia. In rats, morphological changes in the neurons of the parietal cortex and the CA1 field of the hippocampus were studied. For morphometric and histochemical studies, animals were quickly removed after decapitation of the brain, pieces of the anterior cortex of the cerebral hemispheres were fixed in Carnoy fluid. Serial paraffin sections were stained with 0.1 % toluidine blue according to the Nissl method. Statistical hypothesis testing was performed using the Kruskal-Wallis ANOVA test. Results and discussion. The morphological and functional disorders in the parietal cortex and hippocampus have been revealed in animals of both experimental groups. The appointment of omega-3 did not significantly affect the size and shape of neurons in both the parietal cortex and the hippocampus. In the hippocampus, the administration of omega-3 polyunsaturated fatty acids resulted in a decrease in the number of hyperchromic shriveled neurons (by 20%) and an increase in hyperchromic neurons by 31 %. The number of shadow cells in this section did not differ from the indices of the control group. In the parietal cortex, no corrective effect was noted. Conclusions. Thus, subtotal cerebral ischemia leads to the development of morphofunctional disorders of the cerebral cortex. Administration of omega-3 had a positive effect on the state of rat hippocampal neurons, reducing the number of degenerative forms of neurons. The data obtained can serve as the basis for the search for new approaches to the treatment of acute ischemic stroke, which is one of the urgent problems of experimental and clinical neurology
Effects of Experemental Cerebral Ishemia on Metabolic Characteristics of Parietal Cortex Neurons
Cerebral Ischemia, Parietal Cortex, NeuronsThe aim of the paper was to estimate the effect of experimental cerebral ischemia on metabolic characteristics ofparietal cortex neurons. The experiments were carried out on 12 laboratory male rats. Cerebral ischemia was modeled with
bilateral joint carotid arteries with durations of 60 minutes under intravenous thiopental anesthesia (40-50 mg / kg). The ratswere decapitated and the samples of the brain parietal cortex were prepared for histological and histochemical examination incombination with morphometry to examine the 5th layer inner pyramidal neurons. It was increased the number of pathological forms and shrinkage of the 5th layer inner pyramidal neurons after cerebral ischemia in rats. The histochemical examination was revealed the inhibition of NADH-, glucose-6-phosphate dehydrogenase and succinate dehydrogenases as well as activation of lactate dehydrogenase and acid phosphatase. Cerebral ischemia induces deep histological and histochemical changes in the parietal cortex neurons in rats, including shrinkage of parietal cortex neurons and disturbances of their energy
metabolism
Association of prooxidant-antioxidant disorders with the development of morphofunctional disorders in rats with subtotal cerebral ischemia
The aim of the study was to investigate morphofunctional disorders of neurons in the cerebral cortex and changes in the prooxidant-antioxidant state in rats after subtotal cerebral ischemia. Material and methods. The experiments were performed on 20 white outbred male rats. Surgical interventions were carried out under intravenous thiopental anesthesia (40–50 mg/kg). Subtotal cerebral ischemia was simulated by both common carotid arteries ligation. Animals were decapitated after 60 minutes of ischemia. Morphological and functional changes in the neurons of the parietal cortex and hippocampal CA1 field, and intensity of free radical oxidative processes (content of thiobarbituric acid reactive substances and thiol-disulfide system components) in brain homogenates were studied. Results and discussion. Brain ischemia has been followed by oxidative stress in brain tissue. The cellular metabolism has been disturbed under the oxidative stress that leads to a water-electrolyte imbalance, manifested by deformation of neuron bodies, wrinkling, and swelling. The changes in parietal cortex are to a greater extent expressed, as the neurons are more sensitive to oxygen deficiency
Bangladesh Agro-Climatic Environmental Monitoring Project
The Agro-Climatic Environmental Monitoring Project (ACEMP) is based on a Participating Agency Service Agreement (PASA) between the Agency for International Development (AID) and the National Oceanic and Atmospheric Administration (NOAA). In FY80, the Asia Bureau and Office of Federal Disaster Assistance (OFDA), worked closely to develop a funding mechanism which would meet Bangladesh's needs both for flood and cyclone warning capability and for application of remote sensing data to development problems. In FY90, OFDA provided for a High Resolution Picture Transmission (HRPT) receiving capability to improve their forecasting accuracy for cyclones, flooding and storm surges. That equipment is primarily intended as a disaster prediction and preparedness measure. The ACEM Project was designed to focus on the development applications of remote sensing technology. Through this Project, AID provided to the Bangladesh Government (BDG) the equipment, technical assistance, and training necessary to collect and employ remote sensing data made available by satellites as well as hydrological data obtained from data collection platforms placed in major rivers. The data collected will enable the BDG to improve the management of its natural resources
Morphological disturbances of rat parietal cortex and hippocampus neurons in the dynamics steady subtotal ischemia of the brain
The purpose of the work is to analyze changes in the morphological characteristics of neurons of phylogenetical different parts of the cerebral cortex (parietal cortex and hippocampus) of rats at different periods in the dynamics of stepwise subtotal experimental cerebral ischemia. Methods. The experiments were performed on 42 males of outbred white rats. Step subtotal cerebral ischemia was performed as follows: first, one common carotid artery was ligated, simulating partial ischemia. Then, with an interval of 1 day (subgroup 1), 3 days (subgroup 2) or 7 days (subgroup 3), the second common carotid artery was ligated. Results. A microscopic study of the size, shape, degree of chromatophilia of the cytoplasm and the content of ribonucleoproteins in pyramidal neurons of phylogenetically different parts of the cerebral cortex have shown the dependence of the severity of brain damage on the interval between the cessation of blood flow in both carotid artery. Adaptation was better with a 7-day interval between dressings, while the ligation with an interval of 1 day, the degree of morphological changes was maximum indicating a lack of resources for the implementation of adaptation mechanisms
Levels of Free Amino Acids and their Derivatives in the Brain Cortex of Rats During Unilateral Ischemia
amino acids, brain, ischemia.The efficiency of treatment of ischemic brain damage depends upon integrity of sofisticated conceptions of its pathogenesis. One of the prospective approaches in the development of most comprehensive treatment can be the study of the pool of free amino acids (AAs) as a possible target for the correction in such pathology. Available information does not provide a complete view on the changes of their
content under ischemia of various severity.
The aim of the study was to evaluate changes in the content of free amino acids and their derivatives in the frontal cortex of the cerebral hemispheres of rats at different terms of unilateral ischemia.
Materials and methods: The changes of pool of A As and their derivatives in the frontal cortex of the cerebral hemispheres at different duration of unilateral cerebral ischemia (UCI) (1 hour, 3 hours, 1 day) were studied in 18 rats. The analyses of the levels of AAs and their derivatives were carried out in the supernatant of protein-free tissue homogenates by reversed-phase liquid chromatography using chromatograph Agilent 1100.
Results: Shifts of AAs content after 3 h of UCI observed included the raise of lysine, branched chain AAs (BCAA) – valine and leucine, depletion of the aromatic AAs (AAA) — tyrosine and tryptophan with the doubled ratio of BCAA/AAA. Moreover, we observed the decrease in the content of asparagine and essential/nonessential AAs and glycogenic/ketogenic AAs ratios. These changes were disappeared
after 1 day of UCI.
Conclusions: These results show possible mechanisms of development of the energy and neurotransmitter imbalances and their implications in the function of the brain with pathology studied. It is feasible that limitation on BCAA in this pathology will reduce consequences of mediator disturbancies caused by the deficiency of the precursors of biogenic amines – tyrosine and tryptophan
Development of fever under combined administration of substrate and inhibitor of inducible NO-syntase in experimental peritonitis
The purpose of the study was to study the development of fever under combined administration of a substrate and an inhibitor of inducible NO-synthase in experimental peritonitis.Цель исследования – изучение развития лихорадки в условиях сочетанного введения субстрата и ингибитора индуцируемой NO-синтазы при экспериментальном перитоните
Изменения аминокислотного пула в теменной доле и гиппокампе крыс при неполной церебральной ишемии
Introduction. Amino acids and their derivatives are involved in synaptic transmission as neurotransmitters and neuromodulators, and some of them are involved in the formation of neurotransmitters of the nervous system. Therefore, the study of the state of the amino acid pool in incomplete cerebral ischemia plays a significant role.The objective was to assess the nature of changes in amino acid pool and evaluate their participation in oxidative processes in rats with incomplete cerebral ischemia.Methods and materials. The experiments were carried out on 16 male outbred white rats weighing 260±20 g in compliance with the requirements of the Directive of the European Parliament and of the Council No. 2010/63/EU of September 22, 2010 on the protection of animals used for scientific purposes.Results. Compared with the indicators in the control group, rats with an ischemic period of 1 hour in the parietal lobe had a decrease in the content of sulfur-containing amino acids: methionine by 12 % and cysteate by 28 %. In addition, there was an increase of L-arginine in the parietal lobe by 39 %, and in the hippocampus – by 56 %.Conclusions. The following changes are characteristic for one-hour incomplete cerebral ischemia: a decrease in the content of sulfur-containing amino acids, with a decrease in both methionine and an increase in the content of L-arginine. Changes in the parietal lobe and hippocampus had a similar nature, except for the absence of a drop in the level of cysteate in the hippocampus, as a reflection of the higher sensitivity of the parietal lobe to oxygen deficiency, compared with the hippocampus.Введение. Аминокислоты и их дериваты принимают участие в синаптической передаче как нейротрансмиттеры и нейромодуляторы, а некоторые из них участвуют в образовании медиаторов нервной системы. Поэтому изучение состояния аминокислотного пула при неполной ишемии головного мозга играет значимую роль.Цель – оценить характер изменения пула аминокислот и оценить их участие в оксидативных процессах у крыс с неполной ИГМ.Методы и материалы. Опыты выполнялись на 16 самцах беспородных белых крыс массой 260±20 г с соблюдением требований Директивы Европейского Парламента и Совета № 2010/63/EU от 22.09.2010 г. о защите животных, использующихся для научных целей.Результаты. По сравнению с показателями в группе «контроль» у крыс с продолжительностью ишемического периода 1 час в теменной доле происходило уменьшение содержания серосодержащих аминокислот: метионина на 12 % и цистеата на 28 %. Наряду с этим отмечалось увеличение L-аргинина в теменной доле на 39 %, а в гиппокампе – на 56 %.Выводы. Для одночасовой неполной ишемии головного мозга характерны следующие изменения: уменьшение содержания серосодержащих аминокислот со снижением метионина и повышение содержания L-аргинина. Изменения в теменной доле и гиппокампе носили аналогичный характер, за исключением отсутствия падения уровня цистеата в гиппокампе, как отражение более высокой чувствительности теменной доли к дефициту кислорода по сравнению с гиппокампом
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