The sequence of changes in circulating immune cells and in free radical production was studied during the small intestine reperfusion. Rat small intestine ischemia/reperfusion was induced by a 45 min superior mesenteric artery occlusion followed by a 4-hour reperfusion. Samples of peripheral blood were collected every 20 min during reperfusion. While the number of polymorphonuclear leukocytes increased significantly both in the sham-operated controls and the experimental group (about 400 % at the end of reperfusion), a decrease in lymphocyte counts to 60 % was observed in the experimental group only. Although there were no changes in the counts of total T lymphocytes, a significant reduction in B cell counts was observed. Flow-cytometrical measurements showed no changes in the Tc subpopulation, while the Th subpopulation increased in the experimental group only. Free radical generation in blood (luminometric measurements) increased gradually and reached an eight-fold level by the end of reperfusion in both groups. Thus, it has been shown that the increase in free radical production is mainly due to the increased number of polymorphonuclear leukocytes mobilized already at the initial stages of reperfusion. The reduction in B lymphocyte population is probably due to homing mechanisms., J. Hamar, I. Rácz, M. Číž, A. Lojek, É. Pállinger, J. Fűrész., and Obsahuje bibliografii
Leptin is produced by white adipose tissue and other cell types and is involved in both short- and long-term appetite control. Here we studied effects of star vation on serum, pituitary and hypothalamic levels of leptin during 72 h period. Each of the starved groups was sacrificed simultaneously with the group of ad libitum fed animals. The progression of the discrete starvation response phases was monitored by testing the blood glucose, free fatty acid, urea and corticosterone levels. Starvation caused biphasic increase in corticosterone and free fatty acid levels, and significant but transient decrease in urea and glucose levels. Starvation also abolished diurnal rhythm of changes in leptin concentrations in serum and hypothalamic and pituitary tissues. Only 6 h starving period was sufficient to lock serum leptin at low levels, whereas 12 h were needed to silence leptin production/secretion in hypothalamus for the whole examined period. In contrast, leptin production by pituitary tissues of starved animals required 24 h to reach minimum, followed by full recovery by the end of starvation period. These resu lts indicate the tissue specific pattern of leptin release and suggest that the locally produced leptin could activate its receptor in pituitary cells independently of serum levels of this hormone., P. Vujovic ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
The impact of blasting operations is accompanied by both positive and negative after-effects. Vibrations, activated by explosion, help to disintegrate the rocks representing a positive effect on one hand and a negative effect on the other and they endanger the surrounding buildings and other properties. If the vibrations are large enough, then the ambient objects could be damaged or destroyed. The negative effects depend on their range and strength. Vibration intensity of seismic waves is generally proportional to the weight of the explosive used. Recently, negative effects of the blasting operations and quantification of the seismic safety have been highly actual and stand for a challenging problem. The article highlights the results of the blasting operation monitoring in some quarry in Slovakia., Julián Kondela and Blažej Pandula., and Obsahuje bibliografické odkazy