Exercise stimulates increases in heart rate (HR), stroke volume (SV) and cardiac output (CO). These adaptive mechanisms are strongly dependent on the type of exercise. Both rowing and cycling are widely used for physical training worldwide; however, evidence regarding the differences in major hemodynamic parameters during rowing and cycling remains insufficient. Ten healthy male volunteers were randomly assigned to perform either a rowing or cycling exercise. After 20 min rest, the group who had rowed first performed the cycling exercise and vice versa. Exercise was performed at a power-to-weight ratio of 2 W/kg for 2 min. HR, SV, CO and blood pressure (BP) were measured noninvasively using pulse-wave analysis at baseline and immediately after each exercise. HR, SV and CO were significantly higher after exercise than at rest. Whereas HR was comparable between rowing and cycling, SV and CO were significantly higher after rowing than after cycling. BP was comparable among all three measurements. Rowing increased SV and CO to a greater extent than cycling, whereas HR and BP were not influenced by the type of exercise. Our data suggest that rowing leads to more extensive stimulation of cardiac contractility and/or decreases in peripheral vascular resistance compared with cycling., P. Horn, P. Ostadal, B. Ostadal., and Obsahuje bibliografii
We present a review about the relationship between ryanodine receptors and voltage-gated calcium channels in myocardium, and also how both of them are related to protein kinase A. Ryanodine receptors, which have three subtypes (RyR1-3), are located on the membrane of sarcoplasmic reticulum. Different subtypes of voltage-gated calcium channels interact with ryanodine receptors in skeletal and cardiac muscle tissue. The mechanism of excitation-contraction coupling is therefore different in the skeletal and cardiac muscle. However, in both tissues ryanodine receptors and voltage-gated calcium channels seem to be physically connected. FK-506 binding proteins (FKBPs) are bound to ryanodine receptors, thus allowing their concerted activity, called coupled gating. The activity of both ryanodine receptors and voltage-gated calcium channels is positively regulated by protein kinase A. These effects are, therefore, components of the mechanism of sympathetic stimulation of myocytes. The specificity of this enzyme’s targeting is achieved by using different A kinase adapting proteins. Different diseases are related to inborn or acquired changes in ryanodine receptor activity in cardiac myocytes. Mutations in the cardiac ryanodine receptor gene can cause catecholamine-provoked ventricular tachycardia. Changes in phosphorylation state of ryanodine receptors can provide a credible explanation for the development of heart failure. The restoration of their normal level of phosphorylation could explain the positive effect of beta-blockers in the treatment of this disease. In conclusion, molecular interactions of ryanodine receptors and voltage-gated calcium channels with PKA have a significant physiological role. However, their defects and alterations can result in serious disturbances., M. M. Petrovič, K. Valeš, B. Putnikovič, V. Djulejič, D. M. Mitrovič., and Obsahuje bibliografii a bibliografické odkazy
Calcium cycling is a major determinant of cardiac function. S100A1 is the most abundant member of the calcium-binding S100 protein family in myocardial tissue. S100A1 interacts with a variety of calcium regulatory proteins such as SERCA2a, ryanodine receptors, L-type calcium channels and Na+/Ca2+ exchangers, thus enhancing calcium cycling. Aside from this major function, S100A1 has an important role in energy balance, myofilament sliding, myofilament calcium sensibility, titin-actin interaction, apoptosis and cardiac remodeling. Apart from its properties regarding cardiomyocytes, S100A1 is also important in vessel relaxation and angiogenesis. S100A1 potentiates cardiac function thus increasing the cardiomyocytes’ functional reserve; this is an important feature in heart failure. In fact, S100A1 seems to normalize cardiac function after myocardial infarction. Also, S100A1 is essential in the acute response to adrenergic stimulation. Gene therapy experiments show promising results, although further studies are still needed to reach clinical practice. In this review, we aim to describe the molecular basis and regulatory function of S100A1, exploring its interactions with a myriad of target proteins. We also explore its functional effects on systolic and diastolic function as well as its acute actions. Finally, we discuss S100A1 gene therapy and its progression so far., S. Duarte-Costa, R. Castro-Ferreira, J. S. Neves, A. F. Leite-Moreira., and Obsahuje bibliografii
The saccadic eye movement related potentials (SEMRPs) enable to study brain mechanisms of the sensorimotor integration. SEMRPs provide insight into various cognitive mechanisms related to planning, programming, generation and execution of the saccadic eye movements. SEMRPs can be used to investigate pathophysiological mechanisms of several disorders of the central nervous system. Here we shortly summarize basic findings concerning the significance of SEMRP components, their relationship to the functional brain asymmetry and visual attention level as well as changes related to certain neuropsychological disorders., F. Jagla, M. Jergelová, I. Riečanský., and Obsahuje bibliografii a bibliografické odkazy
To date, a single report has appeared on the use of salivary cortisol for adrenal function testing with a low dose ACTH, although 1 μg has become preferred as a more physiological stimulus than the commonly used 250 μg ACTH test. Our present study was aimed to obtain physiological data on changes of free salivary cortisol after 1 μg ACTH stimulation. This approach was compared with the common method based on the changes of total serum cortisol. Intravenous, low-dose ACTH test was performed in 15 healthy women (aged 22-40 years) with normal body weight, not using hormonal contraceptives, in the follicular phase of the menstrual cycle. Blood and saliva for determination of cortisol were collected before ACTH administration and 30 and 60 min after ACTH administration. Basal concentration of salivary cortisol (mean ± S.E.M., 15.9±1.96 nmol/l) increased after 1 μg ACTH to 29.1±2.01 nmol/l after 30 min, and to 27.4±2.15 nmol/l after 60 min. The differences between basal and stimulated values were highly significant (p<0.0001). The values of salivary cortisol displayed very little interindividual variability (p<0.04) in contrast to total serum cortisol values (p<0.0001) A comparison of areas under the curve (AUC) related to initial values indicated significantly higher AUC values for salivary cortisol than for total serum cortisol (1.89±0.88 vs. 1.22±0.19, p<0.01). Correlation analysis of serum and salivary cortisol levels showed a borderline relationship between basal levels (r=0.5183, p=0.0525); correlations after stimulation were not significant. Low-dose ACTH administration appeared as a sufficient stimulus for increasing salivary cortisol to a range considered as a normal adrenal functional reserve., K. Šimůnková, R. Hampl, M. Hill, J. Doucha, L. Stárka, K. Vondra., and Obsahuje bibliografii a bibliografické odkazy
According to European Working Group on Sarcopenia in Older People (EWGSOP) sarcopenia includes both a loss of muscle strength and a decline in functional quality in addition to the loss of muscle protein mass. In order to develop strategies to prevent and treat sarcopenia, the risk factors and causes of sarcopenia must be identified. Age-related muscle loss is characterized by the contribution of multiple factors, and there is growing evidence for a prominent role of low-grade chronic inflammation in sarcopenia. The elderly who are less physically active are more likely to have lower skeletal muscle mass and strength and are at increased risk of developing sarcopenia. Resistance training added to aerobic exercise or high-intensity interval training promote numerous changes in skeletal muscle, many of which may help to prevent or reverse sarcopenia. In this review, we provided current information on definition and monitoring, molecular mechanisms, and physical intervention to counteract sarcopenia., A. zembroń-Łacny, W. Dziubek, Ł. Rogowski, E. Skorupka, G. Dąbrowska., and Obsahuje bibliografii
The present study was undertaken to provide more information on the incidence of satellite nucleoli in developmental stages of the megakaryocytic lineage. Satellite nucleoli representing solitary silver stained nucleolus organizer regions (AgNORs) present in nuclei in addition to other nucleolar types were observed in all stages of megakaryocytic development. However, the incidence of satellite nucleoli was more frequent in mature megakaryocytes than in less differentiated immature megakaryoblasts and naked megakaryocytic nuclei representing the terminal stages of megakaryocytic development after loss of the cytoplasm transformed to thrombocytes. There is a possibility that the increased incidence of satellite nucleoli in mature megakaryocytes might be due to the loss of AgNORs from active nucleoli characteristic for immature cells. The decreased incidence of satellite nucleoli in naked megakaryocytic nuclei might reflect their disintegration in the terminal stages of the megakaryocytic development., J. Janoutová, Z. Likovský, K.Smetana., and Obsahuje bibliografii
To determine the effect of saturated hydrogen saline on lipopolysaccharide (LPS)-induced acute liver dysfunction, rats were divided into control, LPS, and LPS plus saturated hydrogen saline (LPS+H 2 ) groups. Treatment with saturated hydrogen saline prolonged the median su rvival time and reduced liver dysfunction. Moreover, saturated hydrogen saline significantly reduced pathological alterations in liver tissues, the number of ballooned hepatocytes, serum tumor necrosis factor (TNF)- α and interleukin (IL)-6 levels, and myeloperoxidase (MPO) and malondialdehyde (MDA) levels in liver tissues (P<0.05). Cell apoptosis was detected in liver tissues after LPS treatment, and attenuated by saturated hydrogen saline treatment. Saturated hydrogen saline also decreased phosphorylated extracellular signal-regulated kinase (p-ERK), phosphorylated Jun kinase (p-JNK), nuclear factor-kappa B (NF- κ B), and second mitochondria-derived activator of caspase (Smac) levels, and increased p38 activation (P<0.05). Thus, saturated hydrogen saline may attenuate LPS-induced acute liver dysfunction in rats, possibly by reducing inflammation and cell apoptosis. Mitogen- activated protein kinase (MAPK), NF- κ B, and Smac may contribute to saturated hydrogen saline-mediated liver protection., X.-F. Xu, J. Zhang., and Obsahuje seznam literatury
Glucokinase (GCK) plays a key role in glucose metabolism. GCK mutations are known as a pathogenic cause of maturity-onset diabetes of the young type 2 (MODY2). These mutations are also found in gestational diabetics. The aim of our study was to assess the variability of the GCK gene in the Czech diabetic and control populations. We screened all 10 exons specific for the pancreatic isoform of glucokin ase (1a and 2-10) including the intron flanking regions in 722 subjects (in 12 patients with an unrecognised type of MODY and their 10 family members, 313 patients with diabetes mellitus type 2 (DM2), 141 gestational diabetics (GDM), 130 healthy offspring of diabetic parents, and 116 healthy controls without family history of DM2). In two MODY families we identified two mutations in exon 2 of the GCK gene: a novel mutation Val33Ala and the previously described mutation Glu40Lys. In other subgroups (excluding MODY families) we detected only intronic variants and previously described polymorphisms in exons 6 (Tyr215Tyr) and 7 (Ser263Ser), we did not find any known GCK pathogenic mutation. We observed no difference in the frequencies of GCK polymorphisms between Czech diabetic (DM2, GDM) and non- diabetic populations., P. Lukášová, J. Včelák, M. Vaňková, D. Vejražková, K. Andělová, B. Bendlová., and Obsahuje bibliografii a bibliografické odkazy
This article describes the evolution of our understanding of familial hypercholesterolemia (FH) in the Central, Eastern, and Southern Europe (CESE) region, and the dissemination of this understanding to other count ries. Using the ScreenPro FH project as an example, we would like to illustrate the progression from national objectives, to regional networking and, finally, to international collaboration via the Familial Hypercholesterolemia Studies Collaboration (FHSC) project under the leadership of the European Atherosclerosis Society (EAS). It is essential to improve our ability to diagnose FH. In this regard, the EAS and its FHSC project must be commended for their educational and organizational activities which, ab ove all, are dedicated to the creation of a global FH patient registry. In the CESE region, FH diagnostics and treatment situation are markedly different than in Western Europe or North America. Since the Czech MedPed project (Make Early Diagnoses to Preve nt Early Deaths in Medical Pedigrees) has been so successful (with results not only comparable to, but, for some parameters, even surpassing the results of many Western countries) we decided to apply the Czech experience to the CESE region. Thus, the ScreenPro FH project was created. The aim of ScreenPro FH is to create a specialist network in the CESE region. The primary objective of the ScreenPro FH project was to dramatically reduce the number of premature deaths due to clinical complications of atherosc lerosis in FH patients. At present, ScreenPro FH comprises 18 member countries with a total population of 500,000,000; which, in terms of the FH population, represents 1-2 million patients., R. Ceska, T. Freiberger, M. Vaclova, T. Aleksicova, L. Votavova, M. Vrablik., and Obsahuje bibliografii