Previous results have suggested that orexins causes a rise of intracellular free calcium ([Ca2+]i) in cultured rat dorsal root ganglion (DRG) neurons, implicating a role in nociception, but the underlying mechanism is unknown. Hence, the aim of the present study was to investigate whether the orexins-mediated signaling involves the PKC pathways in these sensory neurons. Cultured DRG neurons were loaded with 1 μmol Fura-2 AM and [Ca2+]i responses were quantified by the changes in 340/380 ratio using fluorescence imaging system. The orexin-1 receptor antagonist SB-334867-A (1 μM) inhibited the calcium responses to orexin-A and orexin-B (59.1±5.1 % vs. 200 nM orexin-A, n=8, and 67±3.8 % vs. 200 nM orexin-B, n=12, respectively). The PKC inhibitor chelerythrine (10 and 100 μM) significantly decreased the orexin-A (200 nM)-induced [Ca2+]i increase (59.4±4.8 % P<0.01, n=10 and 4.9±1.6 %, P<0.01, n=9) versus response to orexin-A). It was also found that chelerythrine dose-dependently inhibited the [Ca2+]i response to 200 nM orexin-B. In conclusion, our results suggest that orexins activate intracellular calcium signaling in cultured rat sensory neurons through PKC-dependent pathway, which may have important implications for nociceptive modulation and pain., M. Ozcan ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
The microcirculation plays a crucial role in the interaction between blood and tissues both in physiological and pathophysiological states. Despite its critical role in numer ous diseases including diabetes, hypertension, sepsis or multiple organ failure, methods for direct visualization and quantitative assessm ent of human microcirculation at the bedside are limited. Orthogonal polarization spectral (OPS) imaging is a relatively new noninvasive method for assessment of human microcirculation without using fluorescent dyes. Recent clinical studies using OPS imaging in various pathological states have shown a wide spectrum of different clinical applications with evident impact on the diagnosis, treatment or prognosis assessment. Thus, there is a great effort to validate OPS imaging for various clinical purposes. The principles of OPS imaging, validation studies, its advantages, limitations, methods of quantitative assessment and current experience in clinical practice are discussed., V. Černý, Z. Turek, R. Pařízková., and Obsahuje bibliografii a bibliografické odkazy
It was hypothesized that an oscillation of tissue oxygen index (TOI) determined by near-infrared spectroscopy during recovery from exercise occurs due to feedback control of adenosine triphosphate and that frequency of the oscillation is affected by blood pH. In order to examine these hypotheses, we aimed 1) to determine whether there is an oscillation of TOI during recovery from exercise and 2) to determine the effect of blood pH on frequency of the oscillation of TOI. Three exercises were performed with exercise intensities of 30 % and 70 % peak oxygen uptake (Vo2peak) for 12 min and with exercise intensity of 70 % Vo2peak for 30 s. TOI during recovery from the exercise was analyzed by fast Fourier transform in order to obtain power spectra density (PSD). There was a significant difference in the frequency at which maximal PSD of TOI appeared (Fmax) between the exercises with 70 % Vo2peak for 12 min (0.0039±0 Hz) and for 30 s (0.0061±0.0028 Hz). However, there was no significant difference in Fmax between the exercises with 30 % (0.0043±0.0013 Hz) and with 70 % Vo2peak for 12 min despite differences in blood pH and blood lactate from the warmed fingertips. It is concluded that there was an oscillation in TOI during recovery from the three exercises. It was not clearly shown that there was an effect of blood pH on Fmax., T. Yano, R. Afroundeh, K. Shirakawa, C.-S. Lian, K. Shibata, Z. Xiao, T. Yunoki., and Obsahuje bibliografii
A mathematical description is presented of osmotic flows across both ideally semipermeable membranes and membranes permeable not only for the solvent but also for the solute. The principles of thermodynamics of irreversible processes used for the description are given and illustrated on the example of electroosmosis. Modern ideas about the physical basis of osmotic pressure on porous membranes are discussed and an experiment is described that models the processes of osmosis on a macroscopic level., K. Janáček, K. Sigler., and Obsahuje bibliografii
This article reviews the development of artificial bone substitutes from their older single-phase forms to novel multi-phase composites, mimicking the composition and architecture of natural bone tissue. The new generation of bone implants should be bioactive, i.e. they should induce the desired cellular responses, leading to integration of the material into the natural tissue and stimulating self-healing processes. Therefore, the first part of the review explains the common principles of the cellmaterial interaction and summarizes the strategies how to improve the biocompatibility and bioactivity of the materials by modifying the physico-chemical properties of the material surface, such as surface chemistry, wettability, electrical charge, rigidity, microroughness and especially nanoroughness. The latter has been shown to stimulate preferentially the growth of osteoblasts in comparison with other competitive cell types, such as fibroblasts, which could prevent fibrous tissue formation upon implantation. The second more specialized part of the review deals with materials suitable for bone contact and substitution, particularly novel polymer-based composites reinforced with fibres or inorganic particles and containing bioactive components, such as crystals of hydroxyapatite or other calcium phosphates, synthetic ligands for cell adhesion receptors or growth factors. Moreover, if they are degradable, they can be gradually replaced with a regenerating tissue., B. Vagaská ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
Mesenchymal stem cells (MSCs) have been repeatedly shown to be able to repair bone defects. The aim of this study was to characterize the osteog enic differentiation of miniature pig MSCs and markers of this differentiation in vitro . Flow-cytometrically characterized MSCs were seeded on cultivation plastic (collagen I and vitronectin coated/uncoated) or plasma clot (PC)/plasma- alginate clot (PAC) scaffolds and differentiated in osteogenic medium. During three weeks of differentiation, the formation of nodules and deposition of calcium were visualized by Alizarin Red Staining. In addition, the production of alkaline phosphatase (ALP) activity was quantitatively detected by fluorescence. The expression of osteopontin, osteonectin and osteocalcin were assayed by immunohistochemistry and Western Blot analysis. We revealed a decrease of osteopontin expression in 2D and 3D environment during differentiation. The weak initial osteonectin signal, culminating on 7th or 14th day of differentiation, depends on collagen I and vitronectin coating in 2D system. The highest activity of ALP was detected on 21th day of osteogenic differentiation. The PC scaffolds provided better conditions for osteogenic differentiation of MSCs than PAC scaffolds in vitro . We also observed expected effects of collagen I and vitronectin on the acceleration of osteogenic differentiation of miniature pig MSC. Our results indicate similar ability of miniature pig MSCs osteogenic differentiation in 2D and 3D environment, but the expression of osteogenic marker s in scaffolds and ECM coated monolayers started earlier than in the monolayers without ECM., J. Juhásová ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
Osteoporosis in chronic diseases is very frequent and pathogenetically varied. It complicates the course of the underlying disease by the occurrence of fractures, which aggravate the quality of life and increase the mortality of patients from the underlying disease. The secondary deterioration of bone quality in chronic diseases, such as diabetes of type 1 and type 2 and/or other endocrine and metabolic disorders, as well as inflammatory diseases, including rheumatoid arthritis - are mostly associated with structural changes to collagen, altered bone turnover, increased cortical porosity and damage to the trabecular and cortical microarchitecture. Mechanisms of development of osteoporosis in some inborn or acquired disorders are discussed., I. Zofkova, P. Nemcikova., and Obsahuje bibliografii
Muscarinc receptor-mediated signaling takes part in many physiological functions ranging from complex higher nervous activity to vegetative responses. Specificity of action of the natural muscarinic agon ist acetylcholine is effected by action on five muscarinic receptor subtypes with particular tissue and cellular localization, and coupling preference with different G-proteins and their signalin g pathways. In addition to physiological roles it is also implicated in pathologic events like promotion of carcinoma cells growth, early pathogenesis of neurodegenerative diseases in th e central nervous system like Alzheimer's disease and Parkinson's disease, schizophrenia, intoxications resulting in drug addiction, or overactive bladder in the periphery. All of these disturbances demonstrate involvement of specific muscarinic receptor subtypes and point to the importance to develop selective pharmacotherapeutic interventions. Because of the high homology of the orthosteric binding site of muscarinic receptor subtypes there is virtually no subtype selective agonist that binds to this site. Activation of specific receptor subtypes may be achieved by developing allosteric modulators of acetylcholine binding, since ectopic binding domains on the receptor are less conserved compared to the orthosteric site. Potentiation of the effects of acetylcholine by allosteric modulators would be beneficial in cases where acetylcholine release is reduced due to pathological conditions. When presynaptic function is severly compromised, the utilization of ectopic agonists can be a thinkable solution., J. Jakubík ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
According to several studies, women with Crohn's disease (CD) had reduced fertility, which is mostly due to voluntary decisions and reduced ovarian reserve. In our study, we aimed to compare reproductive health parameters (RHP), previous pregnancy complications and outcomes, and ovarian reserve (OR) assessed by the anti-Mullerian hormone (AMH) in CD patients with healthy controls. In CD patients, we also compared OR according to disease phenotypes. Consecutive pre-menopausal women with CD from two IBD centers were included. The control group consisted of age and BMI-matched healthy controls. We used a questionnaire that included RHP, CD phenotype, and CD activity. Serum AMH was assessed by the Elecsys AMH plus essay. We enrolled 50 patients and 56 controls with a median age of 31 years. All CD patients were in clinical remission. We observed no difference in RHP or AMH (median 2.6 vs. 2.1 ug/l, p = 0.98), or the proportion of low OR (AMH<1,77, 38 vs. 41.1 %, p=0.84). The slope of age-related decrease did not differ between the groups. The subgroup of CD patients after surgery and those older than 30 years with CD for >5years had a steeper decrease in AMH (slope -0.12 vs. -0.29, p = 0.04 and - 0.31 vs. -0.2, p = 0.029). In a multivariate analysis, age was the single independent predictor of low OR (OR=1.25). In women with Crohn’s disease, once the disease activity is under control, the reproductive health and ovarian reserve do not substantially differ from healthy controls., Tomáš Koller, Jana Kollerová, Tibor Hlavatý, Barbora Kadlečková, Juraj Payer., and Obsahuje bibliografii
Beneficial effects of Sambucus nigra L. (black elder) as a traditional medicine have been associated with the phytoconstituents including polyphenols, terpenes and lectins. Various antioxidant rich natural products have also been implicated with improvement of reproductive health and fertility, however, the effect of Sambucus nigra on the ovarian cell functions has not been investigated yet. The objectives of the present study were to screen the polyphenols in the elderflower and elderberry extracts, and to examine the secretion activity of steroid hormones 17β-estradiol and progesterone by human ovarian granulosa cells HGL5 after supplementation of the extracts at a concentration range of 12.5 to 100 µg.ml-1 . Qualitative as well as quantitative screening of polyphenols by high-performance liquid chromatography with diode-array detector (HPLC-DAD) analysis revealed rutin to be the most abundant polyphenol in both elderflower and elderberry extracts. In culture, neither elderflower nor elderberry extract caused any significant impact (p>0.05) in cell viability as studied by AlamarBlue assay in comparison to control. However, a dosedependent stimulation of 17β-estradiol release was detected by ELISA after supplementation of elderflower (at 50 µg.ml-1 ; p<0.01) and elderberry (at 100 µg.ml-1 ; p<0.05) extracts at higher doses used in the study. On the other hand, both elderflower and elderberry extracts stimulated the secretion of progesterone by HGL5 cells at a lower dose (12.5 µg.ml-1 ; p<0.05), as compared to control. Therefore, elderflower and elderberry extracts may have the potential to regulate steroidogenesis in ovarian cells., Simona Baldovska, Shubhadeep Roychoudhury, Marek Bandik, Michal Mihal, Erika Mnahoncakova, Julius Arvay, Ales Pavlik, Petr Slama, Adriana Kolesarova., and Obsahuje bibliografii