Poly-(lactide-co-glycolide) (PLGA) is an FDA-approved biodegradable polymer which has been widely used as a scaffold for tissue engineering applications. Collagen has been used as a coating material for bone contact materials, but relatively little interest has focused on biomimetic coating of PLGA with extracellular matrix components such as collagen and the glycosaminoglycan chondroitin sulfate (CS). In this study, PLGA films were coated with collagen type I or collagen I with CS (collagen I/CS) to investigate the effect of CS on the behaviour of the osteoblastic cell line MG 63. Collagen I/CS coatings promoted a significant increase in cell number after 3 days (in comparison to PLGA) and after 7 days (in co mparison to PLGA and collagen-coated PLGA). No influence of collagen I or collagen I/CS coatings on the spreading area after 1 day of culture was observed. However, the cells on collagen I/CS formed numerous filopodia and displayed well developed vinculin-containing focal adhesion plaques. Moreover, thes e cells contained a significantly higher concentration of osteocalcin, measured per mg of protein, than the cells on the pure collagen coating. Thus, it can be concluded that collagen I/CS coatings promote MG 63 cell proliferation, improve cell adhesion and enhance osteogenic cell differentiation., M. Vandrovcová ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
The effects of inclusion of sesamin / episesamin in Baltic Atlantic salmon ( Salmo salar L.) diets based on vegetable oils were studied. The study was designed as a dose response study with two control diets, one diet based on fish oil (FO) and one diet based on a mixture of linseed and sunflower oil (6:4 by vol.) (MO). As experimental diets three different levels of inclusion of sesamin / episesamin (hereafter named sesamin) to the MO based diet and one diet based on sesame oil and linseed oil (SesO) (1:1 by vol.) were used. Th e dietary oils were mirrored in the fatty acid profile of the white muscle. Sesamin significantly decreased the levels of 18:3n-3 in the white muscle phospholipid (PL) fraction of all groups fed sesamin, no significant differences were found in the triacylglycerol fraction (TAG). Slightly increased levels of docosahexaenoic acid (22:6n-3, DHA) in PL and TAG were found in some of the sesamin fed groups. Sesamin significantly affected the expressi on of peroxisome proliferator- activated receptor α , scavenger receptor type B and hormone sensitive lipase, in agreement wi th previous studies on rainbow trout ( Oncorhynchus mykiss ) and Atlantic salmon ( Salmo salar L.) hepatocytes published by our group. No significant effects on toxicological response measured as ethoxyresorufin O-deethylase activity was found. The total cytochrome P450 enzymes were significantly higher in MO 0.29 and SesO group. The amount of α - and γ -tocopherols in liver and the amount of γ -tocopherol in white muscle were significantly lower in fish fed the FO diet compared to the MO diet, but no difference after inclusion of sesamin was found in this study. Increased inclusion of sesamin increased the levels of sesamin and episesamin in the liver, but did not affect the amounts in white muscle., S. Trattner ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
Oxygen supply was corrected in rabbits during the hepatic ischemia/reperfusion by means of different breathing mixtures: hypoxic (14.8 % O2+85.2 % N2), hyperoxic (78 % O2+20.2 % N2+ 1.8 % CO2), or hypercapnic (5 % CO2 in air). Hepatic ischemia was induced for 30 min by ligation of hepatic artery, reperfusion period lasted 120 min. Indices of blood oxygen transport (p50act, pCO2, pH, pO2, etc.) and prooxidant-antioxidant balance (Schiff bases, conjugated dienes, catalase, retinol, a-tocopherol) were measured in the blood and liver. The severity of reperfusion damage was evaluated by the activities of alanine and aspartate aminotransferases (ALT, AST) in the blood. Hepatic ischemia/reperfusion resulted in higher p50act in hepatic venous and mixed venous blood in all experimental groups. The changes of p50act were most marked in the hypercapnic group and were the weakest in the hypoxic group. The rise in p50act was accompanied by higher levels of lipid peroxidation products, ALT and AST in blood and liver homogenates, and by a simultaneous fall of α-tocopherol and retinol concentrations, except in the hypoxic group. Catalase activity at the end of reperfusion increased under normoxia, decreased under hyperoxia or hypercapnia and did not change under hypoxia. The moderate hypoxia during reperfusion was accompanied by a better balance between the mechanisms of reactive oxygen species production and inactivation that may be observed by optimal changes in p50act and reduced the hepatic damage in this pathological condition., V. V. Zinchuk, M. N. Khodosovsky, D. A. Maslakov., and Obsahuje bibliografii
The effects of gemfibrozil (GFZ), an antihyperlipidemic agent, on the anionic transport of the human red blood cells (RBC) during the oxygenation-deoxygenation cycle were examined. Gemfibrozil clearly plays a role in the modulation of the anionic flux in erythrocytes; in fact it causes a strong increment of anions transport when the RBCs are in the high-oxygenation state (HOS). Such an effect is remarkably reduced in the low-oxygenation state (LOS). With the aim of identifying the dynamics of fibrate action, this effect has been investigated also in human ghost and chicken erythrocytes. These latter, in fact, are known to possess a B3 (anion transporter or Band 3) modified at the cytoplasmic domain (cdb3) which plays a significant role in the metabolic modulation of red blood cells. The results were analyzed taking into account the well-known interactions between fibrates and both conformational states of hemoglobin i.e. the T state (deoxy-conformation) and the R state (oxy-conformation). The effect of gemfibrozil on anionic influx appears to be due to a wide interaction involving a “multimeric” Hb-GFZ-cdb3 macromolecular complex. and Obsahuje bibliografii a bibliografické odkazy
Surgical Plethysmographic Index (SPI), calculated from pulse photo-plethysmographic amplitude oscillations, has been proposed as a tool to measure nociception anti-nociception balance during general anesthesia, but it is affected by several confounding factor that alter the autonomic nervous system (ANS) modulation. We hypothesized that SPI may be mainly affected by sympathetic stimulation independently from nociception. We studied the effects of two sympathetic stimuli on SPI, delivered through passive head-up tilt at 45 and 90 degrees angles, in nine awake healthy adults. The sympathetic modulation was assessed by means of heart rate variability (HRV) analysis. Mean (SD) SPI significantly increased from baseline to 45 degrees [from 38.6 (13.7) to 60.8 (7.6), p<0.001)] and to 90 degrees angle tilt [82.3 (5.4), p<0.001]. The electrocardiographic mean R-to-R interval significantly shortened during both passive tilts, whereas systolic arterial pressure did not change during the study protocol. HRV changed significantly during the study protocol towards a predominance of sympathetic modulation during passive tilt. Gravitational sympathetic stimulation at two increasing angles, in absence of any painful stimuli, affects SPI in awake healthy volunteers. SPI seems to reflect the sympathetic outflow directed to peripheral vessels., R. Colombo, A. Marchi, B. Borghi, T. Fossali, E. Tobaldini, S. Guzzetti, F. Raimondi., and Obsahuje bibliografii
Histidine (HIS) is an essential amino acid investigated for therapy of various diseases, used for tissue protection in transplantation and cardiac surgery, and as a supplement to increase muscle performance. The data presented in the review show that HIS administration may increase ammonia and affect the level of several amino acids. The most common are increased levels of alanine, glutamine, and glutamate and decreased levels of glycine and branched-chain amino acids (BCAA, valine, leucine, and isoleucine). The suggested pathogenic mechanisms include increased flux of HIS through HIS degradation pathway (increases in ammonia and glutamate), increased ammonia detoxification to glutamine and exchange of the BCAA with glutamine via L-transporter system in muscles (increase in glutamine and decrease in BCAA), and tetrahydrofolate depletion (decrease in glycine). Increased alanine concentration is explained by enhanced synthesis in extrahepatic tissues and impaired transamination in the liver. Increased ammonia and glutamine and decreased BCAA levels in HIS-treated subjects indicate that HIS supplementation is inappropriate in patients with liver injury. The studies investigating the possibilities to elevate carnosine (β-alanyl-L-histidine) content in muscles show positive effects of β-alanine and inconsistent effects of HIS supplementation. Several studies demonstrate HIS depletion due to enhanced availability of methionine, glutamine, or β-alanine., Milan Holeček., and Obsahuje bibliografii
A low birth weight is a new risk factor for the development of premature atherosclerosis. The effect of intrauterine undernutrition on hypercholesterolemia in later life was studied in an experimental model using the Prague Hereditary Hypercholesterolemic (PHHC) rat. Compared to animals in the control group (Wistar rats), animals with an increased sensitivity to high-cholesterol diet (PHHC rats) display hypercholesterolemia. Only in PHHC animals, individuals undernourished in their intrauterine life (hypotrophic group, HG) had a significantly higher total cholesterol, compared with individuals without food restriction in pregnancy (eutrophic group, EG). Restricted food intake in pregnancy led to smaller nests and a decreased number of pups in each litter. We found no significant diferences in birth weight between HG and EG. In spite of similar birth weights in PHHC and Wistar rats, intrauterine undernutrition caused an increase in cholesterolemia in the HG group of the PHHC rats. The effect of intrauterine undernutrition on the development of hypercholesterolemia will most likely play a role in individuals with geneticaly determined increased susceptibility to a high-cholesterol diet. The use of this model of intrauterine undernutrition for the study of hypercholesterolemia has proved to be feasible., P. Szitányi, J. Hanzlová, R. Poledne., and Obsahuje bibliografii
Consumption of seafood containing toxin domoic acid (DA) causes an alteration of glutamatergic signaling pathways and could lead to various signs of neurotoxicity in animals and humans. Neonatal treatment with domoic acid was suggested as valuable model of schizophrenia and epilepsy. We tested how repeated early postnatal DA administration influences the spontaneous behavior of rats in adulthood. Rats were injected with 30 μg DA/kg from postnatal day (PND) 10 until PND 14. Their behavior was observed in the open field test for one hour (Laboras, Metris) at PND 35, PND 42 and PND 112. We did not find any difference between DA treated rats and animals injected with equivalent volume of saline in both test sessions at PND 35 and PND 42. DA rats at PND 112 exhibited significantly higher vertical and horizontal exploratory activity (tested parameters: locomotion, distance travelled, average speed reached during test, grooming and rearing) between the 30th-40th min of the test session and habituated over 10 min later. We conclude that at least in the given experimental design, neonatal DA treatment results in alteration of the spontaneous behavior of rats in adulthood., K. Jandová, P. Kozler, M. Langmeier, D. Marešová, J. Pokorný, V. Riljak., and Obsahuje bibliografii
High blood pressure (BP) of L-NAME hypertensive rats is maintained not only by the absence of nitric oxide (NO)-dependent vasodilatation but also by the enhancement of both sympathetic and angiotensin II-dependent vasoconstriction. The aim of the present study was to evaluate the role of inhibitory G (Gi) proteins, which are involv ed in tonic sympathetic vasoconstriction, in the pathogenesis of NO-deficient hypertension. We therefore studied BP response to chronic L-NAME administration (60 mg/kg/day for 4 weeks) in rats in which the in vivo inactivation of Gi proteins was induced by injection of pertussis toxin (PTX, 10 μg/kg i.v.). The impairment of sympathetic vasoconstriction due to PTX-induced Gi protein inactivation prevents the full development of NO-deficient hypertension because BP of PTX-treated rats subjected to chronic L-NAME administration did not reach hypertensive values. Nevertheless, chronic NO synthase inhibition per se is capable to increase moderately BP even in PTX-treated rats. Our data suggest that the sympathetic vasoconstriction is essential for the development of established NO-deficient hypertension., J. Zicha ... [et al.]., and Obsahuje seznam literatury
An ethanol vapor concentration of 1.6 mmol/l was used to test the diurnal variations of the olfactory response in two groups of snails, which were adapted to different light-dark cycles. The results revealed that the olfactory sensitivity to stimulation with ethanol was significantly increased during the day-time, which corresponds to the scotophase of the light-dark cycle, to which the animals had been adapted (c2-test, P < 0.01)., M. Voss, C. Büchert, C. Missfelder., and Obsahuje bibliografii