Nitric oxide belongs to the most important factors influencing structural and functional properties of vessel wall. Both genetic and environmental factors may influence its metabolism. The aim of this study was to explore whether two common polymorphisms of endothelial nitric synthase (eNOS) may, jointly with smoking, influence the stiffness of large arteries, quantified as pulse wave velocity (PWV). One hundred ninety four subjects free of manifest atherosclerotic disease or chronic pharmacotherapy were selected from population-based postMONICA study. PWV´s were measured using Sphygmocor® device between carotic and femoral arteries (aortic PWV) and between femoral and tibialis-posterior arteries (peripheral PWV). Two common polymorphisms, T786C and G894T, were assessed. Among current smokers, homo- or heterozygous carriers of T786C mutation showed significantly higher peripheral PWV than normal genotype carriers (14.0 vs 10.7 m/s, p<0.002); the same was true for the carriers of G894T mutation (13.9 vs 11.0 m/s, p<0.015). No differences were found in non-smokers, and neither of the eNOS polymorphisms influenced aortic PWV in our setting. In conclusion, genetically determined disorder of nitric oxide metabolism was associated with increased stiffness of peripheral, muscular-type arteries in generally healthy, untreated subjects, but only in the interaction with current smoking., O. Mayer jr. ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
This comparative study of various surface treatments of commercially available implant materials is intended as guidance for orientation among particular surface treatment methods in term of the cell reaction of normal human osteoblasts and blood coagulation. The influence of physicochemical surface parameters such as roughness, surface free energy and wettability on the response of human osteoblasts in the immediate vicinity of implants and on the blood co agulation was studied. The osteoblast proliferation was monitored and the expression of tissue mediators (TNF-α , IL-8, MMP-1, bone alkaline phosphatase, VCAM-1, TGF-β ) was evaluated after the cell cultivation onto a wide range of commercially available materials (titanium and Ti6Al4V alloy with various surface treatments, CrCoMo alloy, zirconium oxide ceramics, polyethylene and carbon/carbon composite). The formation of a blood clot was investigated on the samples immersed in a freshly drawn whole rabbit blood using scanning electron microscope. The surfaces with an increased osteoblast proliferation exhibited particularly higher surface roughness (here Ra > 3.5 μm) followed by a high polar part of the surface free energy whereas the effect of wettability played a minor role. The surface roughness was also the main factor regulating the blood coagulation. The blood clot formation analys is showed a rapid coag ulum formation on the rough titanium-based surfaces. The titanium with an etching treatment was considered as th e most suitable candidate for healing into the bone tissue due to high osteoblast proliferation, the highest production of osteogenesis markers and low production of inflammatory cytokines and due to the most intensive blood clot formation., D. Kubies ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
Acetylcholinesterase inhibitors (AChEIs) are used in the treatment of myasthenia gravis (MG). We investigated the effects of AChEIs on peripheral nicotinic receptors (nAChR), which play a crucial role in the treatment of MG symptoms. The positive modulation of those receptors by AChE inhibitors could have an added value to the anti-AChE activity and might be useful in the therapy of MG. Furthermore, to estimate the potential drawbacks of the compounds, cytotoxicity has been assessed on various cell lines. The whole-cell mode of the patch-clamp method was employed. The experiments were performed on medulloblastoma/rhabdomyosarcoma cell line TE671 expressing human embryonic muscle-like receptor with subunits α2βγδ. The effect of the compounds on cell viability was measured by standard MTT assay (Sigma Aldrich) on ACHN (renal cell adenocarcinoma), HeLa (immortal cell line derived from a cervical carcinoma), HEPG2 (hepatocellular carcinoma) and BJ (skin fibroblasts) cell lines. No positive modulation by the tested AChE inhibitors was observed. Moreover, the compounds exhibited antagonistic activity on the peripheral nAChR. Standard drugs used in MG treatment were shown to be less potent inhibitors of muscle-type nAChR than the newly synthesized compounds. The new compounds showed very little effect on cell viability, and toxicities were comparable to standards. Newly synthesized AChEIs inhibited peripheral nAChR. Furthermore, the inhibition was higher than that of standards used for the treatment of MG. They could be used for the study of nAChR function, thanks to their high antagonizing potency and fast recovery of receptor activity after their removal. However, since no positive modulation was observed, the new compounds do not seem to be promising candidates for MG treatment, even though their cytotoxic effect was relatively low., V. Sepsova, J. Krusek, J. Zdarova Karasova, F. Zemek, K. Musilek, K. Kuca, O. Soukup., and Obsahuje bibliografii
Under certain conditions the isolated reaction centre (RC) of photosystem 2 (PS 2) ís highly vulnerahle to photoinduced damage. With no added secondary electron acceptors or donors tíďs damage is due to singlet oxygen generated by the P680 triplet. This triplet is formed by recombination of the radical pair PóSO+Pheo' and Ihe photoinduced damage only occurs under aerobic conditions. When an electron acceptor is present, the degradation of pigments and the Dl and D2 proteins is due to formation of P680+ and secondary oxidation processes. Under the latter but not the former condition, characteristic pattems of degradation firagments of the Dl and D2 proteins are observed. In particular 24 and 17 kDa breakdown firagments of Dl are obtained while the D2 protein yields firagments having molecular masses of 29 and 21 kDa. Experiments involving the use of antibodies, radiophosphate and speciííc proteolytic digestion indicate that all four firagments contain the C-terminal portions of their mature proteins. These findings indicate that the proteolytic cleavage sites are positioned on the lumenal side of the membrane, particularly in the region spanning transmembrane helices I and II. Related studies on the 24 lď)a Dl protein fragment generated in vivo using Synechocystis sp. PCC 6803 by photoinhibitory treatment give the same conclusion for this firagment. Such a conclusion seems to contrast with the previous suggestion that the initial cleavage of Dl protein associated with its degradatíon and tumover occurs on the outer side of membrane in the region spanning transmembrane helices IV and V.
The earthquakes of magnitudes ML=5.0 and 5.3 in the Kaliningrad enclave of Russia on September 21, 2004 were unexpected in a very low-seismicity area. The earthquakes caused minor damage in the Kaliningrad enclave, in northern Poland and in southwestern Lithuania, and macroseismic intensities of 6-7 (EMS) close to the epicenters. The earthquakes were felt up to 800 km distance. The events have been located under the central-northern part of the Sambia Penninsula at 16 and 20 km depth. Their source mechanism has been found to be a right lateral strike slip on a direction parallel to the edge of the Fennoscandian Shield and the East European Craton. The possible cause of the earthquakes is discussed. With the glaciotectonic cause unlikely, it seems the earthquakes evidence tectonic patterns, possibly resulting from stress propagating all across Europe from the Mediterranean region. Historical information seems to evidence past seismic activity in the region, which together with the 2004 earthquakes show the need to reassess seismic hazard in the area., Paweł Wiejacz., and Obsahuje bibliografii
The detection of the Kautsky effect, i.e. the chlorophyll (Chl) fluorescence índuction kínetics induced in the dark-adapted leaves because of a sudden irradiation, by Hans Kautsky and his students is reviewed here on the occasíon of the 60* anniversary of this CW fluorescence transient discovery and oftBě 100* birth anniversary of Hans Kautsky in 1991.
The study investigates the relationship between the labile iron pool (LIP) in circulating monocytes and markers of iron metabolism, inflammation, oxidative stress, endothelial dysfunction and arterial elasticity in patients with chronic cardiovascular disease and in healthy volunteers. The patie nts with a history of CVEs had significantly higher LIP values tha n did the control group (1.94± 0.46 μM vs. 1.62 ±0.49 μM, p=0.02). Except for the leukocyte number (WBCs), the groups did not differ in other inflammatory markers (CRPus, CD 163, MPO, MMP-1). Similarly, there were no differences in the markers of endothelial dysfunction (ICAM, VCAM, E-selectin, vWF). The CVE group had higher pulse pressures, levels of markers of impaired arterial elasticity (AI, Young's modulus, pulsatility, stiffness index), I MT values and ABI values. The LIP concentration was significantly correlated with the transferrin receptor⁄ferritin ratio, hepcidin levels, VFT content and the ABI and ET values. Patients with a history of CVE have significantly higher concentrations of ir on in their intracellular LIP in circulating monocytes than do healthy controls. The independent and significant correlation of LIP with markers of the progression of atherosclerosis and arterial stiffness suggests LIP as a possible novel marker of atheros clerotic activity., P. Riško, J. Pláteník, R. Buchal, J. Potočková, P. J. Kraml., and Obsahuje bibliografii
a1_The Miocene Ishim Formation is characterized by a considerable distribution area within the southwestern Siberia. These deposits are highly dispersed and are composed mainly of angular quartz grains of aleuritic and pelitic fractions. The study of the Ishim Formation is of interest both for investigating the origin of the sediments, and for justifying these rocks as a new type of mineral raw material for the local construction materials industry. This paper presents the results of first complex studies of the Ishim Formation deposits from two outcrops Masali and Bigila. The studies included determination of the particle size distribution on the laser particle analyzer, semiquantitative determination of the mineral composition (X-ray diffraction analysis), as well as, determination of contents of sesquioxides (X-ray fluorescence analysis), rare and trace elements (Inductively Coupled Plasma Mass Spectrometry) and measurement of specific surface area. The most representative samples were chosen for petrographic studies. In certain extent these deposits are characterized by quite high degree of homogeneity of the mineral, chemical, and granulometric compositions. The main component is SiO2 (about 70 %); other most important components are Al2O3 (about 14 %) and Fe2O3 (2-5 %). At the same time, deposits of the upper part of the Ishim Formation are depleted in CaO, MnO, MgO, TiO2, and P2O5. This is probably due to the fact that the proportion of clayey minerals in the upper part of the formation is lower than that in the lower one. The contents of trace elements in the Ishim Formation are lower or close to their clarke values in the Earth's crust. This is with the exception of such elements as Eu, Tb, Cr, and Sb, which form a strong anomaly and, to a lesser extent, a number of other elements that is probably related to the tectonic setting during the period of sedimentation., a2_The CIA values vary from 68-70 in the lower unit of the Ishim Formation at the transition to the sandy facies to 75-80 in the upper one, which indicates a moderate weathering of rocks. The results obtained testify to the fact that these deposits were formed under the conditions of degrading shallow water bodies. A distinct geomorphological confinement to boundaries of the Neogene river paleovalleys, continuity, high dispersion and, predominantly, quartz composition allow us to consider these deposits as a promising type of filler for construction materials industry., Alexander O. Konstantinov, Pavel V. Smirnov, Olga B. Kuzmina, Irina V. Khazina, Georgii A. Batalin and Bulat I. Gareev., and Obsahuje bibliografii