Uvádíme a porovnáváme názory největších myslitelů antiky a středověku - Platóna, Aristotela, Augustina a Tomáše Akvinského - na povahu a vlastnosti času. Všímáme si, jak se jimi formulované názory a problémy odrážejí v současné fyzice., Pavel Macků, Jan Novotný., and Obsahuje seznam literatury
This study deals with reforms by Josef II, in particular with the abolition of the monasteries as recorded in contemporary sources supporting the reforms being carried out. The author selects some significant themes treated by the proponents of reform. The main theme is the criterion of human nature. Related themes include: monks’ asceticism, celibacy, monasteries as the quintessence of baroque piety, and mendicant orders., Petr Hasan., and Obsahuje bibliografické odkazy
The main characteristics of the Antimüllerian hormone from the points of view of biochemistry, molecular genetics, physiological functions and importance for diagnostics in reproductive endocrinology and related biomedical fields are reviewed. The role of the hormone in male and female development, its participation in oocyte maturation including selection of a dominant follicle are summarized, as well as its changes under various pathological situations in both sexes. The physiological changes of serum AMH leves in the life span in both sexes and their alterations under various pathological conditions are provided, too., R. Hampl, M. Šnajderová, T. Mardešić., and Obsahuje bibliografii a bibliografické odkazy
Research on brown adipose tissue and its hallmark protein, mitochondrial uncoupling protei n UCP1, has been conducted for half a century and has been traditionally studied in the Institute of Physiology (AS CR, Prague), likewise UCP2 residing in multiple tissues for the last two decades. Our group has significantly contributed to the elucidation of UCP uncoupling mechanism, fully dependent on free fatty acids (FFAs) within the inner mitochondrial membrane. Now we review UCP2 physiological roles emphasizing its roles in pancreatic β-cells, such as antioxidant role, possible tuning of redox homeostasis (consequently UCP2 participation in redox regulations), and fine regulation of glucose-stimulated insulin secretion (GSIS). For example, NADPH has been firmly established as being a modulator of GSIS and since UCP2 may influence redox homeostasis, it likely affects NADPH levels. We also point out the role of phospholipase iPLA2 isoform γ in providing FFAs for the UCP2 antioxidant function. Such initiation of mild uncoupling hypothetically precedes lipotoxicity in pancreatic β-cells until it reaches the pathological threshold, after which the antioxidant role of UCP2 can be no more cell-protective, for example due to oxidative stress-accumulated mutations in mtDNA. These mechanisms, together with impaired autocrine insulin function belong to important causes of Type 2 diabetes etiology., P. Ježek ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
Diabetes mellitus is characterized by oxidative stress, which in turn determines endothelial dysfunction. Gliclazide is a sulphonylurea antidiabetic drug with antioxidant effects due to its azabicyclo-octyl ring. It has been reported to potentially protect the vasculature through improvements in plasma lipid levels and platelet function. We hypothesized that gliclazide has a beneficial effect on endothelial function in Goto-Kakizaki rats (GK), an animal model of type 2 diabetes fed an atherogenic diet for 4 months. We evaluated the influence of gliclazide on both metabolic and oxidative status and NO-mediated vasodilation. GKAD rats showed increased oxidative stress and impaired endothelium-dependent vasodilation. GKAD rats treated with gliclazide showed increased sensitivity to NO-mediated vasodilation, a significant decrease in fasting glycemia and insulinemia, and a significant decrease in systemic oxidative stress. In conclusion, our results suggest that gliclazide treatment improves NO-mediated vasodilation in diabetic GK rats with dyslipidemia probably due to its antioxidant effects, although we cannot rule out substantial benefits due to a reduction in fasting blood glucose. The availability of a compound that simultaneously decreases hyperglycemia, hyperinsulinemia, and inhibits oxidative stress is a promising therapeutic candidate for the prevention of vascular complications of diabetes., C. M. Sena ... [et al.]., and Obsahuje seznam literatury
The purpose of this study was to determine the effect of a 15-week omega-3 rich diet on age-related differences in myocardial antioxidant defense and inflammation. 20 mature (M) (6 mo.) and 20 old (O) (15 mo.) male Fisher 344 rats were assigned to two diet groups: Control (CON) or Fish Oil (FO). Following the diet, animals were sacrificed and left ventricular (LV) heart tissue was harvested for biochemical assays and western blot analysis. No differences were observed in expression of LV interleukin-6 (IL-6) and tumor necrosis factor-α as well as hydrogen peroxide (H2O2) production between MCON and OCON. However, LV catalase protein expression and activity were increased in OCON vs. MCON and accompanied by increased expression of superoxide dismutase (SOD)-1. In contrast, LV IL-6 was lower in MFO vs. old rats, and LV H2O2 was decreased in MFO and OFO relative to respective control groups. Protein expression and activity of LV catalase and SOD-1 expression were increased in OFO similarly to OCON, but LV SOD activity was also increased in OFO vs. mature rats. In summary, FO supplementation increased myocardial antioxidant defense in all animals and augmented age-associated increases in antioxidant capacity in the absence of changes in inflammation., S. Lennon-Edwards, T. A. Schellhardt, J. M. Kuczmarski., and Obsahuje bibliografii
Hyperglycemia is known to cause oxidative stress that leads mainly to enhanced production of mitochondrial reactive oxygen species (ROS). It has been demonstrated that hyperbaric oxygen (HBO) treatment also increases the formation of ROS. There are, however, no comprehensive evaluations of such oxidative effects in diabetes which requires HBO treatment. The purpose of this study is to investigate the influence of a clinically-recommended HBO treatment on glucose homeostasis and oxidative stress in rats with streptozotocin (STZ)-induced diabetes. Under the clinically-used HBO exposure protocol, the levels of blood glucose, thiobarbituric acid reactive substances (TBARS) as a lipid peroxidation marker, and the activity of superoxide dismutase (SOD) as an antioxidant enzyme marker were investigated in the erythrocytes, liver, pancreas, skeletal muscle, and brain of rats with STZ-induced diabetes. The levels of blood glucose and TBARS increased significantly (p<0.05), and the activity of SOD decreased significantly (p<0.05) in the erythrocytes and all organs of rats with diabetes subjected to HBO exposure. These results suggested that HBO exposure might boost glucose autoxidation and increase ROS production in STZ-induced diabetes as side-effects of administering HBO treatment for the first time., T. Matsunami ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
Plant-based n-3 polyunsaturated fatty acids (PUFA) possess a prospective antiatherogenic potential. Currant oil from Ribes nigrum L. is one of the few plant oils containing PUFAn-3 (15.3 mol%) in addition to PUFAn-6 (60.5 mol%). This study was aimed at comparing the effects of currant oil with those of lard fat, rich in saturated (43.8 mol%) and monounsaturated (47.0 mol%) fatty acids, on antioxidant parameters, the lipoprotein profile and liver lipids in rats fed on 1 % (w/w) cholesterol diets containing either 10 % of currant oil (COD) or lard fat (LFD). After 3 weeks of feeding, the COD induced a significant decrease in blood glutathione (GSH) and an increase in Cu2+ induced oxidizability of serum lipids, but did not affect liver GSH and t-butyl hydroperoxide-induced lipoperoxidation of liver microsomes. Although the COD did not cause accumulation of liver triacylglycerols as LFD, the lipoprotein profile (VLDL, LDL, HDL) was not significantly improved after COD. The consumption of PUFAn-3 was reflected in LDL as an increase in eicosapentaenoic and docosahexaenoic acid. These results suggest that currant oil affects positively the lipid metabolism in the liver, above all it does not cause the development of a fatty liver. However, adverse effects of currant oil on the antioxidant status in the blood still remain of concern., R. Večeřa, N. Škottová, P. Váňa, L. Kazdová, Z. Chmela, Z. Švagera, D. Walterová, J. Ulrichová, V. Šimánek., and Obsahuje bibliografii