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Biomedical subjects

S Trojan

Publications and source records attributed to S Trojan.

At least 91 records · Page 5Linked to original sources
PubMed1990

[The practicum in physiology: from Laufberger to today].

An outline of Prof. Laufberger's concept of practical exercises in physiology, proposed just after the Second World War, is given. Especially, his new pedagogical approach is emphasized, here. Further, the development of the organization of practical courses in the Institute of Physiology in Prague is described: e.g. the modernization of the methods used, and of the educational process in early 70 s'. Today, the importance of biocybernetics is growing.

Czechoslovakia↗
PubMed1990

[Survival and differentiation of pyramidal cells of the hippocampus after transplantation].

Pyramidal neurons of the CA3 hippocampal area were eliminated by means of the kainic acid. Subsequent transplantation of the embryonal hippocampal tissue suspension brought about an increase of the number of neurons. Groups of nerve cells were located at the tips of the implantation tracts. Neurons formed dendritic trees of various complexity. Most of them had an irregular dendritic branching pattern. Only those located within the pyramidal layer, had the typical arrangement of several basal and one apical dendrite.

Animals↗
PubMed1990

[Effect of the sequelae of acute hypobaric hypoxia on epileptic seizures in laboratory rats. Ontogenic studies].

Male rats of the Wistar strain were exposed at the age of 9, 14 and 18 days for a period of 30 minutes to hypobaric hypoxia corresponding to an altitude of 9,000 m. Twenty-four hours after exposure the right sensoric motor area of the cerebral cortex was repeatedly stimulated (rectangular pulses, 8 Hz, 20 s). Contrary to controls, the 10-day-old animals responded to this stimulation by an epileptic self-sustained after-discharge. In older animals the fits were shorter than in controls. Prolongation of the fits in conjunction with repeated stimulation was preserved. Contrary to controls, after the fourth stimulation the lengthening does not occur. In conjunction with older findings after chronic hypoxia, the authors discuss the possible affection of the monoaminergic mediator system.

Acute Disease↗
PubMed1990

[The effect of ethosuximide on epileptic after-discharges induced by thalamic stimulation in young laboratory rats].

An influence of ethosuximide on thalamically induced epileptic afterdischarges was studied in 47 rats aged 12 and 18 days. An afterdischarge formed by spike-and-wave rhythm was induced only in 18-day-old rats. It exhibited a tendency to progressive prolongation with repeated stimulations (with 15 min intervals). Ethosuximide in a dose of 125 mg/kg i.p. immediately after the first afterdischarge did not change the duration of subsequent afterdischarges. The second type of epileptic afterdischarge formed by spikes and/or serrated waves could be induced in both age groups studied. Ethosuximide even worsened the tendency to progression of epileptic afterdischarges in 12- as well as 18-day-old animals. Ethosuximide did not exhibit an anticonvulsant action against the spike-and-wave afterdischarge in 18-day-old rats. On the contrary, it aggravated the course of progressive changes with repeated stimulations in both age groups.

Aging↗
PubMed1990

[The importance of neuronal plasticity for regeneration and transplantation in the CNS].

In the CA3 area of the hippocampus the pyramidal neurons were destroyed by intraventricular application of kainic acid. After transplantation of a suspension of embryonic hippocampal cells agglomerations of cells at the site of injection were observed. Some of them were in the layer of the destroyed neuronal population. These neurons formed dendritic branches and dendritic spines. As compared with control areas with a normal neuronal population, the neurons at the site of transplantation had less regular branching of dendrites and some of the branches were quite chaotic.

Animals↗
PubMed1990

[The effect of ascorbic acid administration on its levels in the brain tissue in intact and hypoxic 18-day-old rats].

A single dose of ascorbic acid, 1 mg/g of body weight by the i.p. route, caused a marked increase of its content in five areas of the brain in 18-day-old laboratory rats, as compared with intact animals. Acute hypoxia at 9000 m mitigated this increase. Conversely a combination of chronic intermittent hypoxia and ascorbic acid administration led in all investigated areas of the brain to a mild but insignificant rise of values except for the vermis cerebelli, where a significant rise at the 5% level of significance occurred.

Animals↗
PubMed1990

[Reactive hyperemia in the brain of rats after high altitude hypoxia].

Using radioactive microparticles of Sr85 the authors assessed the cardiac minute volume and blood flow through the medulla oblongata, cerebellum, subcortical portions and cerebral cortex in adult laboratory rats 20 hours after 8-hour exposure to high altitude hypoxia of 7000 m. The local blood supply is increased in all parts of the brain, in particular in the medulla oblongata and cerebellum.

Altitude↗
PubMed1990

Influence of hypoxanthine, allopurinol and adenine on resistance of rats and hamsters to hypobaric hypoxia.

The survival time of rats and hamsters in lethal hypoxia was measured after a sublethal exposure and a normoxia break, at the beginning of which purines were administered intraperitoneally in the following dosages: 25 mg/kg hypoxanthine, 50 mg/kg allopurinol, 25 mg/kg adenine. In rats, administration of hypoxanthine decreased the survival time by 20%, administration of allopurinol increased it by 25%. Oxygen overpressure of 5 kPa between the two hypoxic doses resulted in larger differences after hypoxanthine and allopurinol application as compared to normoxia break. In hamsters, the effect of allopurinol, hypoxanthine and oxygen was similar, but smaller than that in rats. Adenine did not significantly affect the survival time of rats or hamsters. If hypoxia was applied only once, the purines had no effect on the survival time of rats or hamsters. No measurable XOD activity was observed in hamsters, whereas in adult rats, 99.46 +/- 13.85 nkat/l were found.

Adenine↗