This paper is devoted to yet unpublished electrode-less methods (ELM) of cell layers impedance measurement based on transformer principle. The main advantage of ELM is elimination uncertainties caused by interface between electrodes and measured electrolyte. The method of avoiding distortion caused by non-ideal transformer transfer function (“deconvolution”) and errors caused by residual voltage is described. The modification of original transformer based method allowing to measure an impedance of inserted object is proposed. Results of several calibration measurements confirming the proper function of ELM including example of transepithelial resistance of cells layer are presented. Crucial parts of measuring system and recommendation for their realization are included., J. Krůšek, S. Ďáďo., and Obsahuje bibliografii
This study has observed possible effect of ellagitannins - compounds from pomegranate on process of steroidogenesis in ovaries. The aim of the study was to investigate the possible effect of punicalagin on secretion of steroid hormones - progesterone, androstenedione, testosterone and 17β-estradiol by ovarian fragments of rabbits in vitro. Ovarian fragments from sexually mature female New Zealand white rabbits (n=20) were incubated without (control group) or with punicalagin at various doses 1, 10 and 100 μg.ml−1 for 24 h. Hormones were evaluated by ELISA (The Enzyme-Linked Immunosorbent Assay). Data showed that progesterone and 17β-estradiol (but not androstenedione and testosterone) release by rabbit ovarian fragments was significantly affected by punicalagin addition at various doses. Punicalagin (at 100 μg.ml-1) significantly (P<0.05) increased progesterone secretion. On the other hand, the release of 17β-estradiol was significantly (P<0.005) decreased by punicalagin addition (at 10 μg.ml-1). Our results suggest that punicalagin could have dose-dependent impact on secretion of steroid hormones progesterone and 17β-estradiol by rabbit ovarian fragments and it may be effector in process of ovarian steroidogenesis., D. Packova, A. A. Carbonell-Barrachina, A. Kolesarova., and Obsahuje bibliografii
There is an increasing eviden ce linking dysbalance between various proinflammatory mediators and higher risk of cardiovascular events and pathologies. Likewise, some of the cardiovascular diseases lately ap peared to have an autoimmune component. Interleukin-1 (IL-1), a master regulator of diverse inflammatory processes in higher eukaryotes and the key player in numerous autoimmune disorders including rheumatoid arthritis, diabetes mellitus or systemic sclerosis, has recently been proved to be involved in development of several cardiovascular diseases as well. This report aims to give a summary on current knowledge about the IL-1 signaling pathways and about the implication of IL-1 and the IL-1 receptor antagonist (IL-1Ra) in some of the diseases of the cardiovascular system., B. Vicenová ... [et al.]., and Obsahuje seznam literatury
The rat strain transgenic for the murine Ren-2 renin gene (TGR) is defined as a monogenic model of angiotensin II-dependent hypertension with endogenous activation of the renin-angiotensin system. Homozygous males TGR develop malignant hypertension with a strong salt-sensitive component. These animals show severe hypertension, proteinuria and high mortality. Morphological changes of renal parenchyma correspond to chronic ischemic glomerular changes. Heterozygous TGR develop only mild hypertension and thus provide a more suitable model of hypertension regarding to clinic al studies. Within the renal parenchyma, secondary focal segmental glomerulosclerosis (FSGS) predominates. High-salt diet in heterozygous animals induces transition from benign to malignant phase of hypertension. In this case, ischemic glomerular changes are superimposed on preexisting secondary FSGS. In the regression model of hypertension (late-onset treatment) the effect of salt intake is attenuated. In homozygous TGR, early selective ET A receptor blockade decreased blood pressure and ameliorated end-organ damage. Late selective ET A receptor blockade reduced podocyte injury despite final severe hypertension. Survival rate was markedly improved in both regimens with ETA selective blockade, while there was only partial improvement with early non-selective blockade. Both bosentan and atrasentan decreased ET-1 levels in both regimens. In heterozygous TGR, early and late ETA treatment substantially while ETA/ETB treatment partially improved survival rate. Significant effect on BP was found with early and late ETA blockade, while ETA/ETB blockade had no effect. Bosentan and at rasentan similarly decreased ET-1 levels on both regimens. In conclusion, selective ETA receptor blockade is superior to nonselective ETA/ETB receptor blockade in attenuating hypertension and end-organ damage. Its effect is more pronounced when applied early in the life., Z. Vernerová ... [et al.]., and Obsahuje seznam literatury
Left ventricular assist devices (LVAD), currently used in treatment of terminal heart failure, are working on principle of rotary pump, which generates continuous blood flow. Non-pulsatile flow is supposed to expose endothelial cells to high stress and potential damage. Therefore, we investigated longitudinal changes in concentration of circulating endothelial microparticles (EMP) as a possible marker of endothelial damage before and after implantation of LVAD. Study population comprised 30 patients with end-stage heart failure indicated for implantation of the Heart Mate II LVAD. Concentrations of microparticles were measured as nanomoles per liter relative to phosphatidylserine before and 3 months after implantation. At 3 months after implantation we observed significant decrease in concentration of EMP [5.89 (95 % CI 4.31-8.03) vs. 3.69 (95 % CI 2.70-5.03), p=0.03] in the whole group; there was no difference observed between patients with ischemic etiology of heart failure (n=18) and with heart failure of non-ischemic etiology (n=12). In addition, heart failure etiology had no effect on the rate of EMP concentration decrease with time. These results indicate possibility that LVAD do not cause vascular damage 3 months after implantation. Whether these results suggest improvement of vascular wall function and of endothelium is to be proved in long-term studies., P. Ivak, J. Pitha, P. Wohlfahrt, I. Kralova Lesna, P. Stavek, Z. dorazilova, J. Stepankova, J. Maly, M. Pokorny, I. Netuka., and Obsahuje bibliografii
One of the most significant insults that jeopardize cardiomyocyte homeostasis is a surge of reactive oxygen species (ROS) in the failing myocardium. Early growth response factor-1 (Egr-1) has been found to act as a transcriptional regulator in multiple biological processes known to exert deleterious effects on cardiomyocytes. We thus investigated the signaling pathways involved in its regulation by H2O2. Egr-1 mRNA levels were found to be maximally induced after 2 h in H2O2-treated H9c2 cells. Egr-1 respective response at the protein level, was found to be maximally induced after 2 h of treatment with 200 μM H2O2, remaining elevated for 6 h, and declining thereafter. H2O2- induced upregulation of Egr-1 mRNA and protein levels was ablated in the presence of agents inhibiting ERKs pathway (PD98059) and JNKs (SP600125, AS601245). Immunofluorescent experiments revealed H2O2-induced Egr-1 nuclear sequestration to be also ERK- and JNK-dependent. Overall, our results show for the first time the fundamental role of ERKs and JNKs in regulating Egr-1 response to H2O2 treatment in cardiac cells at multiple levels: mRNA, protein and subcellular distribution. Nevertheless, further studies are required to elucidate the specific physiological role of Egr-1 regarding the modulation of gene expression and determination of cell fate., I.-K. S. Aggeli, I. Beis, C. Gaitanaki., and Obsahuje bibliografii a bibliografické odkazy
a_1 We sought to examine the association between maternal erythrocyte omega-3, omega-6 and trans fatty acids and risk of preeclampsia. We conducted a case-control study of 170 women with proteinuric, pregnancy-induced hypertension and 185 normotensive pregnant women who delivered at Harare Maternity Hospital, Harare, Zimbabwe. We measured erythrocyte omega-3, omega-6 and trans fatty acid as the percentage of total fatty acids using gas chromatography. After multivariate adjustment for confounding factors, women in the highest quartile group for total omega-3 fatty acids compared with women in the lowest quartile experienced a 14 % reduction in risk of preeclampsia (odds ratio 0.86, 95 % confidence interval 0.45 to 1.63). For total omega-6 fatty acids the odds ratio was 0.46 (95 % confidence interval 0.23 to 0.92), although there was suggestion of a slight increase in risk of preeclampsia associated with high levels of arachidonic acid. Among women in the highest quartile for arachidonic acid the odds ratio was 1.29 (95 % confidence interval 0.66 to 2.54). A strong statistically significant positive association of diunsaturated fatty acids with a trans double bond with risk of preeclampsia was observed. Women in the upper quartile of 9-cis 12-trans octadecanoic acid (C18:2n6ct) compared with those in the lowest quartile experienced a 3-fold higher risk of preeclampsia (odds ratio = 3.02, 95 % confidence interval 1.41 to 6.45). Among women in the highest quartile for 9-trans 12-cis octadecanoic acid (C18:2n6tc) the odds ratio was 3.32 (95 % confidence interval 1.55 to 7.13)., a_2 Monounsaturated trans fatty acids were also positively associated with the risk of preeclampsia, although of much reduced magnitude. We observed a strong positive association of trans fatty acids, particularly diunsaturated trans fatty acids, with the risk of preeclampsia. We found little support for the hypothesized in verse association between omega-3 fatty acids and preeclampsia risk in this population. Polyunsaturated fatty acids, particularly omega-3 fatty acids, were comparatively lower in Zimbabwean than among US pregnant women. Given the limited inter-person variation in omega-3 fatty acids among Zimbabwean women, our sample size may be too small to adequately assess the relation in this population., K. Mahomed, M. A. Williams, I. B. King, S. Mudzamiri., and Obsahuje bibliografii a bibliografické odkazy
Effects of ETB receptor stimulation and its subcellular pathways were evaluated in carbachol pre-contracted rabbit iris sphincter muscles (n=51). ETB stimulation with sarafotoxin (SRTX-c; 10-10-10-6 M) was tested in the absence (n=7) or presence of 10-5 M of: BQ-788 (ETB2 receptor antagonist; n=6), L-NA (NOS inhibitor; n=7) or indomethacin (cyclooxygenase inhibitor; n=10). Effects of ETB stimulation by endothelin-1 (ET-1; 10-10–10-7 M) in the presence of an ETA receptor antagonist (BQ-123; 10-5 M; n=7) and of ETB1 stimulation by IRL-1620 (10-10–10-7 M; n=7) were also tested. Finally, the effects of SRTX-c (10 -9 –10 -7 M) in electric field stimulation (EFS) contraction were evaluated (n=7). ETB receptor stimulation by SRTX-c or ET-1 in presence of BQ-123 promoted a concentration-dependent relaxation of the rabbit iris sphincter muscle by 10.8±2.0 % and 9.4±1.8 %, respectively. This effect was blocked by BQ-788 (-2.3±2.0 %), L-NA (4.5±2.3 %) or indomethacin (2.3±2.9 %). Selective ETB1 stimulation by IRL-1620 did not relax the iris sphincter muscle (0.9±5.4 %). EFS elicited contraction was not altered by SRTX-c. In conclusion, ETB receptor stimulation relaxes the carbachol precontracted iris sphincter muscle, an effect that is mediated by the ETB2 receptor subtype, through NO and the release of prostaglandins., A. Rocha-Sousa ... [et al.]., and Obsahuje seznam literatury
The aim of this study was to investigate the effects of calcium channel blockers on tertbutyl hydroperoxide (TBH) induced liver injury using isolated perfused rat hepatocytes. Rat hepatocytes were immobilized in agarose threads and perfused with Williams E medium. Hepatocyte injury was induced by the addition of tertbutyl hydroperoxide (1 mM) to the perfusion medium 30 min after the addition of either verapamil or diltiazim. Hepatocyte injury was observed by monitoring the functional and metabolic competence of hepatocytes or by ultrastructural morphological examination of hepatocytes. Verapamil (0.5 mM) reduced lactate dehydrogenase leakage in TBH-injured hepatocytes as compared to the controls (154± 11 % vs. 247± 30 %). Lipid peroxides production was reduced after verapamil pretreatment as compared to the controls and oxygen consumption was increased by pretreatment of hepatocytes with verapamil. Verapamil pretreatment increased the protein synthesis activity at both levels of granular endoplasmic reticulum and free polysomes in cytoplasm and decreased ATPase activity. Diltiazem was qualitatively effective as verapamil. It is concluded that in hepatocyte oxidative injury, calcium channel blockers exhibited hepatoprotective properties. The hepatoprotective effect of calcium channel blockers was accompanied by a decrease in ATPase activity, which may implicate a normalization of Ca2+i after TBH intoxication., H. Farghali, E. Kmoníčková, H. Lotková, J. Martínek., and Obsahuje bibliografii
The aim of this study was to analyze the ECG time intervals in the course of the development of chronic anthracycline cardiomyopathy in rabbits. Furthermore, this approach was employed to study the effects of a model cardioprotective drug (dexrazoxane) and two novel iron chelating compounds - salicylaldehyde isonicotinoyl hydrazone (SIH) and pyridoxal 2-chlorobenzoyl hydrazone (o-108). Repeated daunorubicin administration induced a significant and progressive prolongation of the QRS complex commencing with the 8th week of administration. At the end of the study, we identified a significant correlation between QRS duration and the contractility index dP/dtmax (r=-0.81; P<0.001) as well as with the plasma concentrations of cardiac troponin T (r=0.78; P<0.001). In contrast, no alterations in ECG time intervals were revealed in the groups co-treated with either dexrazoxane or both novel cardioprotective drugs (SIH, o-108). Hence, in this study, the QRS duration is for the first time shown as a parameter suitable for the non-invasive evaluation of the anthracycline cardiotoxicity and cardioprotective effects of both well established and investigated drugs. Moreover, our results strongly suggest that novel iron chelators (SIH and o-108) merit further study as promising cardioprotective drugs against anthracycline cardiotoxicity., A. Potáčová, M. Adamcová, H. Čajnáková, L. Hrbatová, M. Štěrba, O. Popelová, T. Šimůnek, P. Poňka, V. Geršl., and Obsahuje bibliografii a bibliografické odkazy