INFLUENCE OF INFRALOW-FREQUENCY MAGNETIC-FIELD ON THE NERVOUS CELLS RHYTHM AND THEIR TOLERANCE TO HYPOXIA

The direct effect of infralow-frequency (0,05, 0,1, 0,25 Hz, 100 nT) magnetic fields (MF) was demonstrated on the brain cellular-tissue model-surviving slices of mouse cerebellum. MF influence is a trigger for the nervous cells. MF-5 Hz revealed two-phases response: inhibition and excitation of the impulse activity of neurons. Besides that we recorded convulsive effect of MF. The experiments with simultaneous exposure of hypoxia and MF revealed a prohypoxia effect of MF, when the oxygen concentration was very low and also after reoxygenation. The surviving slices may be used as a model for studying the fine mechanisms of influence of different intensity MF on the nervous cells

Individual resistance of the organism and nerve cell to hypoxia

The correlation between the pattern of a neuron's reaction to acute hypoxia and individual resistance to oxygen deficit is studied on rats in vivo as well as on surviving slices of their cerebellum in vitro. According to the survival time in a pressure chamber simulating an altitude of 11 km all the rats were divided into groups of high resistance, medium resistance, and low resistance to hypoxia. Survival time was 4.2 times longer in the high resistance group than in the low resistance group. In the cerebellar slices of high resistance animals 61.5% high-resistance neurons and 38.5% low-resistance neurons were recorded. On the other hand, in the high resistance animals the percentage of high-resistance neurons and low-resistance neurons was 31.2 and 68.8, respectively. The period of hypoxia development was 4.32 times longer in the high-resistance neurons as compared to low-resistance neurons. It is speculated that individual differences in the resistance to O2 deficit are of a hereditary nature and manifest themselves not only on the level of the whole organism, but also in the individual nerve cell. © 1995 Plenum Publishing Corporation

INFLUENCE OF INFRALOW-FREQUENCY MAGNETIC-FIELD ON THE NERVOUS CELLS RHYTHM AND THEIR TOLERANCE TO HYPOXIA

The direct effect of infralow-frequency (0,05, 0,1, 0,25 Hz, 100 nT) magnetic fields (MF) was demonstrated on the brain cellular-tissue model-surviving slices of mouse cerebellum. MF influence is a trigger for the nervous cells. MF-5 Hz revealed two-phases response: inhibition and excitation of the impulse activity of neurons. Besides that we recorded convulsive effect of MF. The experiments with simultaneous exposure of hypoxia and MF revealed a prohypoxia effect of MF, when the oxygen concentration was very low and also after reoxygenation. The surviving slices may be used as a model for studying the fine mechanisms of influence of different intensity MF on the nervous cells

EFFECTS OF SOME PHARMACOLOGICAL AGENTS ON ELECTRICAL-ACTIVITY OF THE CEREBELLUM SLICES UNDER HYPOXIA

[No abstract available

Effects of some pharmacological agents on electrical activity of the cerebellum slices under hypoxia

[No abstract available

Features of disorders in the hemostasis system in acute peritonitis on the background of diabetes mellitus

Background. Until now, acute peritonitis remains in the focus of attention in modern abdominal surgery, which is due to the preservation of a high level of morbidity and mortality, as well as high treatment costs. Materials and methods. 46 patients with acute appendicitis complicated by peritonitis were studied, divided into 2 groups: the first (n=28) – without concomitant diabetes mellitus; and the second (n = 18) – with diabetes mellitus (mainly of the first type). The patients were operated on: appendectomy, sanitation and drainage of the abdominal cavity were performed. Methods: assessment of the state of the hemostasis system, platelet aggregation activity, their lipid composition, the severity of oxidative processes and phospholipase activity. Follow-up period: before surgery, 2 and 5 days after surgery. Results. It was found that in acute peritonitis, there was an increase in the level of diene conjugates and malondialdehyde in the blood plasma at the observation stages by 70.8, 54.2 and 98.6, 82.3% (р < 0.05), a decrease in the activity of superoxide dismutase by 37.5 and 33.1% (р < 0.05), an increase in the activity of phospholipase A2 by 141.7 and 44.8% (р < 0.05). During hospitalization of patients to the clinic, an increase in the content of cholesterol esters, cholesterol, triglycerides in platelets was noted by 13.9, 13.6, 20.9% (р < 0.05), respectively. An increase in the degree of platelet aggregation was revealed by 18.3% (р < 0.05). Coagulation time was reduced by 21.1% (р < 0.05), clot formation – by 22.4% (р < 0.05). The fibrinolysis time was prolonged by 21.2% (р < 0.05). Comparative analysis has shown that in diabetes mellitus there are large violations in the system of hemostasis and homeostasis in general. In patients of this group, the content of diene conjugates and malondialdehyde in blood plasma exceeded those of the comparison group at all stages of observation by 22.0-23.4 and 15.1-18.0% (р < 0.05), the activity of superoxide dismutase decreased by 17.1-18.3% (р < 0.05), phospholipase A2 increased by 44.8-42.5% (р < 0.05).<0.05). Changes in the lipid spectrum of platelets increased: cholesterol levels were higher by 14.7% (р < 0.05), triglycerides – by 21.2% (р < 0.05), free fatty acids – by 19.3% (р < 0.05). Comparative analysis of the hemostasis system showed that the coagulation reaction time in this group on the 2nd and 5th days decreased by 14.2 and 26.3% (р < 0.05), the time of clot formation - by 15.1 and 13.6% (р < 0.05), the percentage of lysis – by 19.4 and 12.5% (р < 0.05). Conclusions. One of the significant factors in the modulation of the hemostasis system in comorbid pathology of patients with acute peritonitis is a significant activation of trigger agents leading to oxidative stress, excessive phospholipase activity, changes in the composition of platelet lipids, hypercoagulemia, inhibition of fibrinolytic activity, microthrombosis. This is especially evident in conditions burdened with diabetes mellitus, in which the activity of hemocoagulation triggers and their effect on the hemostasis system is detected to a greater extent