Autologous vein grafts used as aortocoronary bypasses are often prone to intimal hyperplasia, which results in stenosis and occlusion of the vein. The aim of this study was to prevent intimal hyperplasia using a newly developed perivascular system with sustained release of sirolimus. This system of controlled drug release consists of a polyester mesh coated with a copolymer of L-lactic acid and ε -caprolactone that releases sirolimus. The mesh is intended for wrapping around the vein graft during surgery. The mesh releasing sirolimus was implanted in periadventitial position onto arteria carotis communis of rabbits, and neointimal hyperplasia was then assessed. We found that implanted sirolimus-releasing meshes reduced intima thickness by 47±10 % compared to a vein graft after 3 weeks. The pure polyester mesh decreased vein intima thickness by 35±9 %. Thus, our periadventitial system for controlled release of sirolimus prevented the develo pment of intimal hyperplasia in autologous vein grafts in vivo in rabbits. A perivascularly applied mesh releasing sirolimus is a promising device for preventing stenosis of autologous vein grafts., I. Skalský ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
We have assessed the phylogenetic status of the Leishmania genome project Friedlin reference strain by MLEE and multiprimer RAPD including a set of 9 stocks representative of the main Leishmania species and of the whole genetic diversity of the Leishmania genus. To our knowledge, the detailed genetic characterization of the Friedlin strain has never been published before. As previously recorded (Tibayrenc et al. 1993), MLEE and RAPD data gave congruent phylogenetic results. The Friedlin reference strain was definitely attributed to Leishmania (Leishmania) major Yakimoff et Schokhor, 1914. Five specific RAPD patterns made it possible to distinguish between the Friedlin strain and the 2 other L. (L.) major stocks included in the study. Various specific MLEE and RAPD characters permitted to distinguish between the Leishmania species included in the study. All these characters are usable to detect accidental laboratory mix-ups involving the Friedlin reference strain. In confirmation with previous studies involving a more limited set of genetic markers, the general genetic diversity of the Leishmania genus proved to be considerable. It must be made clear that only one strain cannot be considered as representative of the whole genetic variability of the genus Leishmania. In the future, it is therefore advisable to complement the results obtained in the framework of the Leishmania genome project with data from other strains that should be selected on a criterion of important genetic differences with the Friedlin strain.
Diabetic nephropathy (DN), the most serious complication of Type 1 diabetes (DM1), has a strong genetic component. Cyclooxygenase-2 (COX-2), an in ducible enzyme by a number of stimuli, has been implicated in pathophysiology of cardiovascular and renal disease, including DN. The allele -765C, of the -765G>C polymorphism (rs20417) in the COX-2 promoter has lower promoter activity compared with the -765G allele and protective effects in cardiovascular disease. This polymorphism was not investigated in patients with DM1 and nephropathy. The study was conducted in 779 Caucasian patients with DM1 and compared to a representative sample of healthy Czech population. The patients demonstr ated lower frequencies of the CC genotype (P=0.005). From th e DM1 cohort, 153 patients met the criteria for low risk of the development of DN (LRDN, duration of DM1>10 years, normoalbuminuria, normotension) and 139 patients had manifest DN. There were no differences in -765G>C polymorphisms between LRDN and DN patients. Moreover, the C/G allele frequenc ies did not also differ between the groups. In conclusion, patients with DM1 display lower freqencies of the protective CC genotype as compared to healthy subjects. However, the study did not reveal associations of -765G>C polymorphism with the risk of DN., J. A. Hubáček ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
Chronic sojourn in hypoxic environment results in the structural remodeling of peripheral pulmonary arteries and pulmonary hypertension. We hypothesize that the pathogenesis of changes in pulmonary vascular structure is related to the increase of radical production induced by lung tissue hypoxia. Hypoxia primes alveolar macrophages to produce more hydrogen peroxide. Furthermore, the increased release of oxygen radicals by other hypoxic lung cells cannot be excluded. Several recent reports demonstrate the oxidant damage of lungs exposed to chronic hypoxia. The production of nitric oxide is high in animals with hypoxic pulmonary hypertension and the serum concentration of nitrotyrosine (radical product of nitric oxide and superoxide interaction) is also increased in chronically hypoxic rats. Antioxidants were shown to be effective in the prevention of hypoxia induced pulmonary hypertension. We suppose that the mechanism by which the radicals stimulate of the vascular remodeling is due to their effect on the metabolism of vascular wall matrix proteins. Non-enzymatic protein alterations and/or activation of collagenolytic matrix metalloproteinases may also participate. The presence of low-molecular weight cleavage products of matrix proteins stimulates the mesenchymal proliferation in the wall of distal pulmonary arteries. Thickened and less compliant peripheral pulmonary vasculature is then more resistant to the blood flow and the hypoxic pulmonary hypertension is developed., J. Herget, J. Wilhelm, J. Novotná, A. Eckhardt, R. Vytášek, L. Mrázková, M. Ošťádal., and Obsahuje bibliografii
Tzv. teorie optimality patří к nejnovějším směrům současného lingvistického bádání. Nejdříve nalezla uplatnění ve fonologii, později v syntaxi a nejnověji i v sémantice. Naše stať naznačuje možnosti a meze uplatnění tohoto pohledu na oblast aktuálního členění věty.
This study was directed to use the genetically developed isoprenaline-sensitive (S), isoprenaline-resistant (R) and spontaneous hypertensive rats (SHR) as standard diseased animal models for in vitro liver function evaluation of drug biotransformation. Hepatic hexobarbital hydroxylase and glutathione transferase (GST) were evaluated by using hexobarbital and l-chloro-2,4-dinitrobenzene (CDNB) as substrates, at concentrations of 0.21 mmol/l and 1 mmol/l, respectively. The assay was conducted by using isolated hepatocytes in suspension and hepatocytes in a bioreactor configuration. The data demonstrate that there are certain cellular pharmacokinetic differénces in hexobarbital hydroxylase and GST activities in hepatocytes obtained from Wistar, SHR, R and S strains which can be better demonstrated, when using the model of perfused and immobilized hepatocytes.
The purpose of the present study was to examine the role of the T-786C endothelial nitric oxide synthase (eNOS) gene polymorphism on changes in renal hemodynamics and blood pressure due to Na+ loading. Twenty-eight older (63±1 years), moderately obese (39±2 % fat) hypertensives had th eir glomerular filtration rate (GFR), renal plasma flow (RPF), blood pressure (BP) and plasma nitric oxide (NOx) levels determined after eight days of low (20 mEq) and high (200 mEq) Na+ diets. The two Na+ diets were separated by a 1-week washout period. Subjects were genotyped for the eNOS-786 site and were grouped on whether they were homozygous or heterozygous for the C allele (TC+CC, n=13) or only homozygous for the T allele (TT, n=15). The TC+CC genotype group had a significantly greater increase in diastolic (P=0.021) and mean arterial (P=0.018) BP and a significant decline in both RPF (P=0.007) and GFR (P=0.029) compared to the TT genotype group with Na+ loading. Furthermore, Na+ loading resulted in a significant (P=0.036) increase in plasma NOx in the TT, but not in the TC+CC genotype group as well as a trend (P=0.051) for an increase in urine NOx in TC+CC, but not in the TT genotype group. The increase in BP during Na+ loading in older hypertensives was associated with the eNOS genotype and may be related to changes in renal hemodynamics due to changes in NO metabolism., D. R. Dengel, M. D. Brown, R. E. Ferrell, T. H. Reynolds, M. A. Supiano., and Obsahuje bibliografii a bibliografické odkazy
We obtain a principal topology and some related results. We also give some hints of possible applications. Some mathematical systems are both lattice and topological space. We show that a topology defined on the any bounded lattice is definable in terms of uninorms. Also, we see that these topologies satisfy the condition of the principal topology. These topologies can not be metrizable except for the discrete metric case. We show an equivalence relation on the class of uninorms on a bounded lattice based on equality of the topologies induced by uninorms.
Ve svém článku se zabýváme srovnáním sémantického pole příbuzenských vztahů ve francouzštině, španělštině a Češtině na základě pěti binárních sémantických opozic. Na základě tohoto srovnání docházíme к závěru, že francouzské termíny vytvářející sémantické pole příbuzenských vztahů jsou sémanticky mnohem vágnější a jejich význam závisí mnohem více na kontextu, než je tomu v případě jejich českých ekvivalentů. Sémantické pole příbuzenských vztahů ve španělštině je založeno na velmi propracovaném systému pojmů označujících příbuzné v linii přímé a na velkém významu protikladu mezi pokrevními a nepokrevními příbuznými. Pro sémantické pole příbuzenských vztahů v češtině je naopak typické mnohem výraznější zastoupení lexikální substituce a menší počet lexikálních jednotek vzniklých derivací a kompozicí. K šémům vytvářejícím pole příbuzenských vztahů ve francouzštině je potřeba připojit v češtině a španělštině sém "předchozí nebo další manželství" pro rozlišení vlastních a nevlastních příbuzných.