The aldosterone synthase gene (CYP11B2) is an important candidate gene region in essential hypertension. We therefore studied the association of -344T/C polymorphism of the CYP11B2 gene with the presence and severity of hypertension in a case-control study. We studied 369 individuals, of whom 213 were hypertensive patients (139 controlled hypertensive, 74 resistant hypertensive) and 156 were healthy normotensive subjects. The -344T/C polymorphism of the CYP11B2 gene was determined using polymerase chain reaction - restriction fragment length polymorphism analysis. The distribution of genotypes in normotensive controls and hypertensive subjects were: TT 25.6 vs. 31.9 %, TC 51.9 vs. 57.3 % and CC 22.4 vs. 10.8 %. The -344T/C variant was associated with hypertension. Subjects carrying the -344T allele had a greater risk of hypertension compared to those having C allele (χ2=5.89, p<0.05). The frequency of CC genotype was significantly lower in hypertensive patients than in normotensive controls ( χ2=9.44, p<0.01). A stepwise logistic regression analysis confirmed these findings. We did not find an association of -344T/C variant with the resistance of hypertensive patients to combination therapy, but we observed an association of -344T/C polymorphism of aldosterone synthase gene with increased risk of hypertension. These results support a potential role of -344T/C CYP11B2 gene polymorphism in genetic predisposition to develop hypertension., Z. Hlubocká ... [et al.]., and Obsahuje seznam literatury
Increasing the biodiversity in plantations of trees is an important issue because plantations have replaced many natural and semi-natural ecosystems worldwide. Therefore, identifying appropriate management techniques and key factors for enhancing biodiversity in plantations is required. We surveyed butterfly assemblages along forest trails in both plantations and natural forests and measured various environmental variables, including canopy, sub canopy and shrub stem densities, percentage of deciduous trees, flower plant richness, host plant richness, canopy openness and distance to forest edge. We hypothesized that (1) flower and host plant richness increase with an increase in the percentage of deciduous trees and canopy openness; (2) butterfly richness and abundance increase with an increase in forest structural complexity, butterfly resources, canopy openness and distance to forest edge; (3) the responses of plants and butterflies to canopy openness differ in plantations and natural forests; and (4) in plantations, tree-feeding butterflies respond to canopy openness less strongly than herbaceous plant feeding butterflies do because of the low diversity of trees in plantations. Our results generally support these hypotheses. Butterfly resources and butterfly richness and abundance all increase with increasing canopy openness; however, the increases were usually more dramatic in natural forests than in plantations and other factors are less important. In plantations, herbaceous plant feeding butterflies responded to increasing canopy openness more strongly than tree-feeding butterflies. The results of the present study indicate the importance of sunlit forest trails in enhancing butterfly resources, butterfly richness and abundance in plantations. Because at the stand-level management is labour- and cost-intensive, labour- and cost-saving trail management options need to be explored further in terms their effectiveness in increasing biodiversity in plantations.
Atrial fibrosis is considered as the basis in the development of long-standing atrial fibrillation (AF). However, in advanced heart failure (HF), the independent role of fibrosis for AF development is less clear since HF itself leads to atrial scarring. Our study aimed to differentiate patients with AF from patients without AF in a population consisting of patients with advanced HF. Myocardial samples from the right atrial and the left ventricular wall were obtained during he art transplantation from the explanted hearts of 21 male patients with advanced HF. Long- standing AF was present in 10 of them and the remaining 11 patients served as sinus rhythm controls. Echocardiographic and hemodynamic measurements were recorded prior to heart transplantation. Collagen volume fraction (CVF), transforming growth factor-beta (TGF- β ), and connective tissue growth factor (CTGF) expression in myocardial specimens were assessed histologically and immunohistochemically. The groups were well matched according to age (51. 9±8.8 vs. 51.3±9.3 y) and co- morbidities. The AF group had high er blood pressure in the right atrium (13.6±7.7 vs. 6.0±5.0 mmHg; p=0.02), larger left atrium diameter (56.1±7.7 vs. 50±5.1 mm; p=0.043), higher left atrium wall stress (18.1±2.1 vs. 16.1±1.7 kdynes/m 2 ; p=0.04), and longer duration of HF (5.0±2.9 vs. 2.0±1.6 y, p=0.008). There were no significant differences in CVF (p=0.12), in CTGF (p=0.60), and in TGF- β expression (p=0.66) in the atrial myocardium between the two study groups. In conclusions, in advanced HF, atrial fibrosis expressed by CVF is invariably present regardless of occurrence of AF. In addition to atrial wall fibrosis, increased wall stress might contribute to AF development in long-standing AF., B. Aldhoon, ... [et al.]., and Obsahuje seznam literatury
Concentrations of numerous hormones decrease with age. Some authors imply that a syndrome of partial endocrine deficiency may occur in the aging men. Among many lifestyle factors that influence hormonal status is physical activity. Especially interesting are relations between physical activity and the androgenic/estrogenic status of men. The aim of this study was to evaluate age-related changes of serum androgens, estradiol and SHBG in men presenting different levels of physical activity. Hormonal parameters were measured in a cohort of 387 healthy Caucasian men (aged from 24 to 72 years) from one administrative region of Poland. Their level of physical activity was determined by means of the International Physical Activity Questionnaire (IPAQ). We have found that contrary to SHBG concentration, total testosterone, free testosterone, bioavailable testosterone, calculated free testosterone and estradiol were negatively associated with age in the investigated subjects. Apart from estradiol, physical activity did not influence concentrations of the studied parameters. In younger (24-48 years), physically active males estradiol was significantly higher than in subjects characterized by a low level of physical activity. The situation was opposite in older males (48-72 years). In this age group low level of physical activity was associated with lower concentration of estradiol. Undertaking physical effort increased the decline of estradiol level with age., M. Slowinska-Lisowska, P. Jozkow, M. Medras., and Obsahuje bibliografii a bibliografické odkazy
This work describes ocular astigmatism and factors which affect it. Further, total and corneal astigmatism are described and it is analyzed their relationship. An analysis of a diameter of a geometric circle of confusion is performed for the case of defocus and astigmatism. The formulas for modeling fundamental image characteristics of an eye are described. The paper is completed with an example of an experimental analysis of corneal and total astigmatism measured by aberrometry and an analysis of the influence of astigmatism on visual acuity. and V práci je popsána stručně problematika astigmatismu oka a faktorů, které jej ovlivňují. Je charakterizován celkový astigmatismus a tzv. rohovkový astigmatismus. Dále je provedena analýza průměru geometrického rozptylového kroužku na sítnici pro případ defokusace a astigmatismu a jsou popsány vztahy, kterými lze modelovat základní obrazové charakteristiky v důsledku aberací optické soustavy oka. Článek je doplněn příkladem experimentální analýzy astigmatismu při aberometrickém měření a vlivu astigmatismu na zrakovou ostrost.
Slovenský asronom a politik generál dr. Milan Rastislav Štefánik prožil většinu svého života ve Francii. Původně se do této země odebral se záměrem pracovat jako astronom na observatoři v Meudonu. Osud ho však zavedl mnohem dále - až do Jižní Ameriky a na tichooceánský ostrov Tahiti. Celá jeho odborná práce v astronomii je protkána nezměrným úsilím jdoucí ruku v ruce s četnými nesplněnými plány a s trvale podlomeným zdravím. Předmětem jeho zájmu byla především sluneční astrofyzika. Po stránce organizační usiloval o vybudování nejprve vysokohorské hvězdárny, později o zajištění pozorovacího místa poblíž rovníku s možnostmi pohledu do vyšších jižních zeměpisných šířek.
Při příležitosti 90. výročí Štefánikovy tragické smrti je obsahem tohoto příspěvku jen práce na poli astronomie. Nechť tím není nijak snížen Štefánkův význam na poli politickém ve prospěch vznikající Československé republiky., František Jáchim., and Obsahuje bibliografii
Astronom a pedagog prof. PhDr. Jindřich Svoboda (1884-1941) patří k významným osobnostem našeho vědeckého a akademického života. Dlouhá léta působil jako profesor na ČVUT, třikrát byl děkanem Vysoké školy speciálních nauk při ČVUT a v akademickém roce 1935/36 stanul jako rektor v čele techniky. Jeho působení především na ČVUT v Praze je spojeno s budováním a rozvojem samostatného vysokého školství nově vzniklého československého státu. V oblasti vědecké je prof. J. Svoboda zakladatelem naší moderní meteoritické astronomie. Do tohoto oboru zavedl vlastní matematické metody zpracování napozorovaných dat a vyvinul řadu pozorovacích metod s využitím jím navržených přístrojů. Přispěl k trvalému rozvoji astronomie malých těles, v níž naše země i dnes zcela vyniká. Prof. J. Svoboda byl uznávanou osobností také v zahraničí. Patřil k nositelům vysokého francouzského vyznamenání Řádu důstojníka Čestné legie., František Jáchim., Součástí článku jsou Svobodovy publikované práce, and Obsahuje seznam literatury