530 research outputs found

    Endothelial function assessment in atherosclerosis: Comparison of brachial artery flow‑mediated vasodilation and peripheral arterial tonometry

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    INTRODUCTION Endothelial dysfunction, characterized by the loss of nitric oxide bioavailability, is a key element in the pathogenesis of atherosclerosis and an important prognostic factor in cardiovascular diseases. Therefore, the development of reliable, safe, and noninvasive methods of endothelial function assessment is important for their use in cardiovascular risk stratification. Brachial artery flow‑mediated dilation (FMD) is widely used in research but technical difficulties and problems with calibration between laboratories limit its clinical use. Reactive hyperemia–peripheral artery tonometry (RH‑PAT, EndoPAT) has been developed as a simpler, cheaper, and potentially more reproducible method. OBJECTIVES We aimed to investigate associations between RH‑PAT and FMD in relation to atherosclerotic risk factor profile. PATIENTS AND METHODS The study involved 80 subjects (52 men, 28 women) aged 43.6 ±14.8 years, with moderate‑to‑low cardiovascular risk (mean SCORE, 2.2% ±2%), in whom FMD, RH‑PAT, and intima–media thickness (IMT) were determined. RESULTS The reactive hyperemia index (RHI) measured by RH‑PAT correlated with FMD (r = 0.35, P <0.01). However, no significant correlation was observed between RHI and IMT, SCORE, or the number of classical atherosclerotic risk factors (hypertension, smoking, diabetes, hypercholesterolemia), while FMD was significantly correlated with IMT (r = –0.53, P <0.001), risk factors (r = –0.55, P <0.05), and SCORE (r = –0.4, P <0.05). CONCLUSIONS Despite its technical requirements, FMD is a more sensitive method than RH‑PAT in evaluating the effect of classical atherosclerotic risk factors on vascular endothelial function. Microvasculature response during RH‑PAT needs to be further studied, including the assessment of nonendothelial factors that may affect the measurements, before RH‑PAT becomes the universal tool for the evaluation of the endothelial cells

    The role of rivers and streams in the migration of alien plants into the Polish Carpathians

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    The Carpathians are among the regions of Poland that are generally less susceptible to invasive alien plants. The factor limiting the spread of the species of this group is, above all, the mountain climate. Even species originating from other mountain regions, e.g. the Himalayan Impatiens glandulifera, have their localities only at low elevations, in the Carpathian foothills. In most cases, alien plant species migrate into the Carpathians from the lowlands. The river valleys provide the migration corridors used by alien species in the course of their progress into new territories of the upper mountain localities. The situation along some mountain rivers, where invasive alien species dominate the native vegetation, is dramatic. Their spread is facilitated not only by easy diaspore transport but also by some anthropogenic factors, such as, river engineering and the transformation of riparian habitats and progressing devastation. Currently, we can observe some invasive alien plants Ñin statu nascendiî, developing a new, secondary range in the Carpathians (e.g. Chaerophyllum aureum) or at the foothills, along the Wis≥a (Vistula) and San river valleys (e.g. Eragrostis albensis). For some species, cities were the destination for the first stage of future migration, e.g. Acer negundo. In the Carpathians, where many national parks and nature reserves are located, the continuous monitoring of the spread of invasive alien plants should be one of the principal activities of botanists

    Extinct and endangered archaeophytes and the dynamics of their diversity in Poland

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    A full list of extinct and endangered archaeophyte species for Poland is presented according to IUCN categories. The species are analysed in respect of their origin and syntaxonomic classification. Endangered archaeophytes should be cultivated in botanical gardens and open-air museums, and next reintroduced to natural sites

    Zmiany w składzie tkankowym obserwowane w trakcie terapii ciężkich zaburzeń funkcji tarczycy

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      Introduction: Hyper- and hypothyroidism are accompanied by altered metabolic rate, thermogenesis, and body weight. The aim of this study was to estimate the relation between treatment-induced changes in thyroid function, and the accompanying body composition in patients with either severe hypo- or hyperthyroidism. Material and methods: Body composition analysis and hormonal assessment were measured at the initial diagnosis of thyroid disorder, after three-month treatment, and finally after complete recovery from hyperthyroidism (n = 18) or hypothyroidism (n = 27). Nonparametric Spearman correlation was used to analyse the relation between thyroid hormones and body composition as well as their respective changes. Results: In hypothyroid patients applied treatment significantly reduced (p < 0.05) total body weight, mainly due to a decrease in fat mass, whereas in hyperthyroid patients it caused a weight gain, with a simultaneous increase in muscle, water and fat mass. Total body weight and fat mass were significantly correlated with thyroid hormones’ concentrations in all patients. Changes of fat, water, or muscle mass were strongly correlated with the changes in the patients’ hormonal status. Conclusions: Body composition is related to the concentration of thyroid hormones in thyroid dysfunction. Treatment-induced changes in thyroid hormones concentrations are correlated with the magnitude of the change of body weight, including muscle, water, and fat amount. (Endokrynol Pol 2016; 67 (4): 359–366)    Wstęp: Zarówno nadczynność, jak i niedoczynność tarczycy charakteryzują się zaburzeniami podstawowej przemiany materii, termogenezy oraz masy ciała. Celem pracy była ocena związku między zmianami funkcji tarczycy oraz zmianami składu tkankowego ciała u pacjentów w trakcie terapii ciężkich zaburzeń funkcji tarczycy. Materiał i metody: Badanie składu ciała oraz badanie biochemicznych wykładników funkcji tarczycy przeprowadzono u 18 chorych z pełnoobjawową nadczynnością tarczycy oraz u 27 chorych z niedoczynnością tarczycy, w okresie rozpoznania choroby, po około trzech miesiącach leczenia oraz po całkowitym wyrównaniu funkcji tarczycy, w okresie eutyreozy. Ponadto przeprowadzono analizę związku między zmianami funkcji tarczycy oraz zmianami w składzie ciała przeprowadzono nieparametryczną analizę Spearmana. Wyniki: W grupie chorych leczonych z powodu niedoczynności tarczycy zaobserwowano statystycznie istotny spadek masy, głównie kosztem masy tkanki tłuszczowej (p< 0,05), podczas gdy w grupie chorych z pierwotnie rozpoznaną nadczynnością tarczycy stwierdzono istotny wzrost masy tkanki tłuszczowej, mięśniowej oraz wody całkowitej (p < 0,05). W obu grupach zaobserwowano ponadto istotne korelacje między stężeniem hormonów tarczycy a masą tkanki tłuszczowej na wszystkich etapach leczenia (p < 0,05). Jednocześnie zmiany wszystkich parametrów składu tkankowego ciała (Δ) silnie korelowały ze zmianami biochemicznych wykładników funkcji tarczycy(Δ) (p < 0,05). Wnioski: W zaburzeniach funkcji tarczycy obserwuje się silne zależności między składem tkankowym ciała a stężeniem hormonów tarczycy. Zmiany w składzie tkankowym ciała są jednocześnie silnie skorelowane ze zmianami stężenia hormonów tarczycy obserwowanymi w trakcie terapii. (Endokrynol Pol 2016; 67 (4): 359–366)

    Biominerals and waxes of Calamagrostis epigejos and Phragmites australis leaves from post-industrial habitats

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    Vascular plants are able to conduct biomineralization processes and collect synthesized compounds in their internal tissues or to deposit them on their epidermal surfaces. This mechanism protects the plant from fluctuations of nutrient levels caused by different levels of supply and demand for them. The biominerals reflect both the metabolic characteristics of a vascular plant species and the environmental conditions of the plant habitat. The SEM/EDX method was used to examine the surface and cross-sections of the Calamagrostis epigejos and Phragmites australis leaves from post-industrial habitats (coal and zinc spoil heaps). The results from this study have showed the presence of mineral objects on the surfaces of leaves of both grass species. The calcium oxalate crystals, amorphous calcium carbonate spheres, and different silica forms were also found in the inner tissues. The high variety of mineral forms in the individual plants of both species was shown. The waxes observed on the leaves of the studied plants might be the initializing factor for the crystalline forms and structures that are present. For the first time, wide range of crystal forms is presented for C. epigejos. The leaf samples of P. australis from the post-industrial areas showed an increased amount of mineral forms with the presence of sulfur

    An evaluation of the reproducibility of the measurement of the intima-media thickness of carotid arteries

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    The intima-media thickness (IMT) of carotid arteries was demonstrated to be a reliable measure for early stages of atherosclerosis. B-mode ultrasound may be used to measure carotid IMT. The measurements of the IMT of the carotid artery (CA) conducted by different investigators can be comparable and enable the implementation of clinical trial successfully while maintaining a high reproducibility value. The objective of the study was to evaluate the reproducibility of the measurements made by the same investigator on two separate occasions (intraobserver variability) and the reproducibility of the off-line measurements between four sonographers in our laboratory (interobserver variability). The IMT of CA in 25 subjects (15 post stroke and 10 healthy persons) was investigated with the use of high-resolution ultrasonography. The CA subdivided into the common, bulbs and internal segments were scanned twice with a 3-week interval. Additionally three other readers with different levels of experience and skills in ultrasonography were asked to perform the same measurements in duplicate with at least a 3-week interval between. A high concurrence for intraobserver variability was detected with a correlation coefficient ranging from 0.92 to 0.95; p < 0.0001, and maximal bias 0.019 mm. Interobserver variability for all four readers also demonstrated a high correlation coefficient ranging from 0.72 to 0.83; p < 0.0001, and the maximal bias of measurements did not exceed 0.08 mm. The analogue measurements performed by the team demonstrate a reliable reproducibility in terms of the results of morphologic measurements. The differences obtained in the study were less than the error of the method (i.e. 0.1 mm) and should not influence clinical decision-making. Additionally, this study demonstrated that interobserver concurrence increases with the increasing experience of the investigators

    Critical behaviour of the mean-field ferromagnet Cu1.02[Cr 1.77Ti0.24]Se4

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    Magnetization, M, and susceptibility, , measurements showed both strong lowering of magnetic moment in comparison with CuCr2Se4 matrix and zero- eld-cooling eld-cooling susceptibility splitting characteristic for the spin-glass behaviour. Isothermal magnetization curves, M(H), easy saturate and large values both of the Curie TC = 253 K and Curie Weiss = 283:5 K temperatures indicate the ferromagnetic order which coexists with the spin-glass state. The critical behaviour investigated around the paramagnetic ferromagnetic phase transition revealed that the values of critical exponents are close to those predicted by the mean eld model for long-range magnetic interactions

    Specific heat and magnetic structure of GdT2X2 compounds (T=Cu,Ni,X=Sn,Sb)

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    The magnetic specific heat of GdΝi 2 Sn2 , GdΝi2 Sb2 and GdCu2 Sb2 shows a λ-type anomaly at TN with a noticeable reduction of the discontinuity compared to that expected for a simple antiferromagnet. It can be associated with the existence of amplitude modulated magnetic structure just below TN. Above TN a weak magnetic contribution is observed, evidencing the short-range ordering. From neutron diffraction studies it can be also concluded that investigated compounds have not simple antiferromagnetic structures. For GdΝi2Sn2 the propagation vector Q = (0.3, 1/2, 1/2) was found with the magnetic moments along the [1,0,0] axis

    The flora and vegetation of an old solvay process tip in Jaworzno (Upper Silesia, Poland)

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    This paper demonstrates the flora, plant communities and substrates of an old soivay process spoil tip in Upper Silesia, Poland. In an area of 15 000 m2 there are growing 136 vascular plant species. The flora is characterised by the preponderance of Asteraceae - species and long-lived perennial herbs, many of them coming from meadows and grasslands. Ninety-five percent of species are apophytes despite the anthropogenic origin of the site. A majority of species are associated with moderately dry, base-rich soils with low or moderate levels of nitrogen. The site is shown to be an important refuge for some protected species, montane species and other elements uncommon in the local flora. An analysis of a series of samples used a methodology based on the assessment of percentage cover of particular species and multivariate analysis based on TWINSPAN. Both suggested a relatively high overall similarity between the samples with minor variations associated with moister substrates. Elemental analysis and pH determinations of soil samples associated with the releves revealed a narrow range of pH and an absence of any strong concentrations of heavy metals. A redundancy analysis of the soil-plant relationships suggested that the strongest trend of differentiation was most closely associated with a phosphate gradient, and the next strongest was pH and possibly waterlogging. The most species-rich vegetation was associated with low phosphate and high pH levels. The results could be interpreted to suggest that processes of soil development and plant succession are slow but nevertheless perceptible, with implications for future loss of diversity. The vegetation constitutes an assemblage essentially of one type showing only weak relationships with described vegetation types such as Molinio-Arrhenatheretea meadow, Festuco- Brometea grassland and Caricetalia davallianae mire. The results also suggest that the vegetation of the site is of considerable value for nature conservation. The site should be protected and be the subject of further research
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