Sleep apnoea (SA) is common in patients with hypertension. Nowadays, limited data on the prevalence of SA in nocturnal hypertension (NH) exist. Therefore, we studied the occurrence of SA in Czech patients and its association with 24-h ambulatory blood pressure monitoring (ABPM), breathing disturbances in sleep, anthropometric data, Mallampati score and Epworth sleepiness scale (ESS) using the Apnea Link device. Undiagnosed SA was found in 72.9 % patients (29.3 % mild, 26.6 % moderate, 17.0 % severe) of 188 patients with NH measured by ABPM. The median of the apnoea-hypopnoea index (AHI) was 12.0 (25th-75th percentile 5.0-23.8). Moderate/severe SA (AHI≥15) was associated with BMI, waist circumference, mean night saturation (SpO2), t90, oxygen desaturation index (ODI), ESS (daytime BP only) (p≤0.032), but not ABPM parameters and Mallampati score (p>0.09). A likelihood of moderate/severe SA was enhanced by ODI>14.5 events/h (odds ratio=57.49, 95 % CI=22.79-145.01), t90>6.5 % (8.07, 4.09-15.92), mean night SpO2<93.5 % (3.55, 1.92-6.59), BMI>29.05 kg/m2 (6.22, 3.10-12.49), circum waist>105.5 cm (3.73, 1.57-8.83), but not by any ABPM parameter. In conclusion, a high incidence of SA (72.9 %) was observed in Czech patients with NH. SA severity was associated with body characteristics and oxygenation parameters, but not with ABMP parameters and Mallampati score., M. Hobzová, K. Šonka, M. Pretl, J. Václavík, E. Kriegová, M. Radvanský, J. Zapletalová, M. Placková, V. Kolek., and Seznam literatury
The high rate of occurrence of sleep disturbances in children with attention-deficit/hyperactivity disorder (ADHD) prompted the idea that structural and neurotransmitter changes might give rise to specific sleep pattern abnormalities. The aim of this study was to evaluate the microstructure of sleep in children with ADHD who had no polysomnographically diagnosed sleep disorder, had never been treated for ADHD, and were free from any psychiatric comorbidity. Participants were 14 patients with ADHD (12 boys and 2 girls aged 7-12 years, mean age 9.6±1.6). ADHD was diagnosed according to DSM-IV criteria (Diagnostic and statistical manual of mental disorders). Psychiatric comorbidities were ruled out by detailed psychiatric examination. The patients underwent two consecutive overnight video-polysomnographic (PSG) recordings, with the sleep microstructure (cyclic alternating pattern – CAP) scoring during the second night. The data were compared with age- and sex-matched controls. Sleep microstructure analysis using CAP revealed no significant differences between the ADHD group and the controls in any of the parameters under study. In conclusions, no ADHD-specific alterations were found in the sleep microstructure., I. Příhodová ... [et al.]., and Obsahuje seznam literatury
Slow breathing training reduces resting blood pressure, probably by modifying central autonomic control, but evidence for this is lacking. The pressor response to static handgr ip exercise is a measure of autonomic control and the aim of this study was to determine whether slow breathing training modulates the pressor responses to exercise of untrained muscles. Twenty hypertensive patients trained for 8 weeks, 10 with unloaded slow breathing (Unloaded) and 10 breathing against an inspiratory load of 20 cm H 2 O (Loaded). Ten subjects were untrained controls. Subjects performed a 2 min handgrip pressor test (30 % MVC) pre - and post- training, and blood pressure and heart rate (HR) were measured before the contraction, at the end and following 2 min recovery. Resting systolic (sBP) and HR were reduced as a result of tra ining, as reported previously. After training there was both a smaller pressor response to hand grip exercise and a more rapid recovery of sBP and HR compared to pre -training. There were no changes in the Controls and no differences between the Unloaded and Loaded groups. Combining the two training groups, the sBP response to handgrip exercise after training was reduced by 10 mm Hg (95 % CI: - 7, - 13) and HR by 5 bpm (95 % CI: - 4, - 6), all p<0.05. These results are consistent with slow breathing training modifying central mechanisms regulating cardiovascular function., C. U. Jones, B. Sangthong, O. Pachirat, D. A. Jones., and Obsahuje bibliografii
We have investigated slow inactivation in a rat axonal K+ channel, the I channel. Using voltage steps to potentials between -70 mV and +80 mV, from a holding potential of -100 mV, we observed a marked slowing of inactivation at positive potentials: the time constant was 4.5±0.4 s at -40 mV (mean ± S.E.M.), increasing to 14.7±2.0 s at +40 mV. Slowed inactivation at positive potentials is not consistent with published descriptions of C-type inactivation, but can be explained by models in which inactivation is preferentially from closed states (which have been developed for Kv2.1 and some Ca2+ channels). We tested two predictions of preferential closed-state models: inactivation should be more rapid during a train of brief pulses than during a long pulse to the same potential, and the cumulative inactivation measured with paired pulses should be greater than the inactivation at the same time during a continuous pulse. The I channel does not behave according to these predictions, indicating that preferential closed-state inactivation does not explain the slowing of inactivation we observe at positive potentials. Inactivation of the I channel therefore differs both from C-type inactivation, as presently understood, and from the inactivation of Kv2.1., A. Babes, E. Lörinczi, V. Ristoiu, M.L. Flonta, G. Reid., and Obsahuje bibliografii
Gastrointestinal motility is an integrated process including myoelectrical and contractile activity, tone, compliance and transit. The techniques for the assessment of gastrointestinal motility are multiple and all have their advantages and disadvantages. In the case of suspected abnormal upper gut transit, gastric and small bowel transit scintigraphy followed by small intestinal (antroduodenojejunalileal) manometry is recommended. Small bowel manometry can identify patterns suggestive of myopathy, neuropathy or obstruction. Information on procedures, indications, significance, pitfalls and guidelines for small bowel manometry is provided in this paper. In this context the potentials of small intestinal manometry for scientific experimental study of neurohumoral agents, such as serotonin receptor agonists and antagonists, on small intestinal motility is presented., M. B. Hansen., and Obsahuje bibliografii
Soluble leptin receptor (SLR) is the extracellular part of the leptin receptor. This protein is released into circulation and constitutes the main circulating leptin-binding protein. The aim of our study was to measure SLR concentrations in patients with chronic renal failure (CRF) and healthy subjects and to explore the relationship of SLR to other hormones and cytokines. The patients with CRF had significantly higher serum leptin, TNF-a and insulin levels than healthy subjects (25.1±23.5 vs. 9.4±7.6 ng.ml-1 (S.D.); 14.2±4.2 vs. 4.55±2.5 ng.ml-1; 39.8±36.1 vs. 20.3±11.1 mU.l-1). Serum soluble leptin receptor levels did not differ between these groups (19.1±11.3 vs. 19.6±6.1 U.ml-1). An inverse relationship between serum SLR and leptin levels was found in both groups. In patients with CRF the inverse relationship between SLR and insulin, body fat content and total protein levels were also found, while in healthy subjects only inverse relationship of SLR with insulin and albumin concentrations were detected. We conclude that soluble leptin receptor levels in patients with chronic renal failure do not differ from those of healthy subjects despite higher serum leptin levels in CRF patients. The physiological consequences of this finding require further investigation., J. Křížová, S. Sulková, V. Bednářová, E. Kotrlíková, M. Haluzík., and Obsahuje bibliografii
The decapeptide QLNLKEYNLV corresponding to the C-terminus of Gq/G11alpha guanine nucleotide-binding proteins (G-proteins) was synthesized by the solid-phase method and conjugated to keyhole limpet hemocyanin. The rabbits were immunized with these conjugates and an antiserum that reacted specifically with the alpha subunit of Gq/G11 proteins was used in this study. The antiserum exhibited no cross-reactivity with the alpha subunits of stimulatory (Gs) or inhibitory (Gi) G-proteins associated with adenylate cyclase. Immunoblots with the antiserum showed that it specifically recognized the Gq/G11 alpha-proteins in cholate extracts of adipose tissue membranes of goats. Treatment of young castrated male goats with bST had no effect on the quantity of Gq/G11 alpha-subunits in adipose tissue and the results thus obtained did not support the idea that the bST signal in adipose tissue is transmitted via Gq/G11 alpha-proteins., V. Krbeček, H. Kovářů, J. Škarda, T. Barth, J. Velek, V. Žižkovský., and Obsahuje bibliografii
Oxidative stress is a phenomenon associated with pathogenetic mechanisms of several diseases including atherosclerosis, neurodegenerative diseases, such as Alzheimer’s and Parkinson’s disease, cancer, diabetes mellitus, inflammatory diseases, as well as psychological diseases or aging processes. Oxidative stress is defined as an imbalance between production of free radicals and reactive metabolites, so-called oxidants, and their elimination by protective mechanisms, referred to as antioxidative systems. This imbalance leads to damage of important biomolecules and organs with potential impact on the whole organism. Oxidative and antioxidative processes are associated with electron transfer influencing the redox state of cells and the organism. The changed redox state stimulates or inhibits activities of various signal proteins, resulting in a changed ability of signal pathways to influence the fate of cells. At present, the opinion that oxidative stress is not always harmful, has been accepted. Depending on the type of oxidants, intensity and time of redox imbalance as well as on the type of cells, oxidative stress can play a role in the regulation of other important processes through modulation of signal pathways, influencing synthesis of antioxidant enzymes, repair processes, inflammation, apoptosis and cell proliferation, and thus processes of malignity. Imprudent administration of antioxidants may therefore have a negative impact on the organism., Z. Ďuračková., and Obsahuje bibliografii a bibliografické odkazy
In the present in vitro experiments we examined FSH- and ghrelin-induced changes in ovarian hormone secretion by transgenic rabbits. Fragments of ovaries isolated from adult transgenic (carrying mammary gland-specific mWAP-hFVIII gene) and non-transgenic rabbits from the same litter were cultured with and without FSH or ghrelin (both at 0, 1, 10 or 100 ng/ml medium). The secretion of progesterone (P4), estradiol (E2) and insulin-like growth factor I (IGF-I) was assessed by RIA. It was observed that ovaries isolated from transgenic rabbits secreted much less P4, E2 and IGF-I than the ovaries of non-transgenic animals. In control animals FSH reduced E2 (at doses 1-100 ng/ml medium) and IGF-I (at 1-100 ng/ml), but not P4 secretion, whereas ghrelin promoted P4 (at 1 ng/ml) and IGF-I (at 100 ng/ml), but not E2 output. In transgenic animals, the effects were reversed: FSH had a stimulatory effect on E2 (at 100 ng/ml) and ghrelin had an inhibitory effect on P4 (at 10 ng/ml). No differences in the pattern of influence of FSH on P4 and IGF-I and of ghrelin on E2 and IGF-I were found between control and transgenic animals. The present observations suggest that 1) both FSH and ghrelin are involved in rabbit ovarian hormone secretion, 2) transgenesis in rabbits is associated with a reduction in ovarian secretory activity, and 3) transgenesis can affect the response of ovarian cells to hormonal regulators., A. V. Sirotkin, P. Chrenek, K. Darlak, F. Valenzuela, Ž. Kuklová., and Obsahuje bibliografii a bibliografické odkazy
Spatial navigation and memory is considered to be a part of the declarative memory system and it is widely used as an animal model of human declarative me mory. However, spatial tests typically involve only static settings, despite the dynamic nature of the real world. Animals, as well as people constantly need to interact with moving objects, other subjects or even with entire moving environments (flowing water, running stairway). Therefore, we design novel spatial tests in dynamic environments to study brain mechanisms of spatial processing in more natural settings with an interdisciplinary approach including neuropharmacology. We also translate data from neuropharmacological studies and animal models into development of novel therapeutic approaches to neuropsychiatric disorders and more sensitive screening tests for impairments of memory, thought, and behavior., A. Stuchlik ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy