Mechanisms underlying atrial fibrillation (AF), the most common cardiac arrhythmia, particularly in aged population, are not fully elucidated. We have previously shown an increased propensity of old guinea pigs (GPs) heart to inducible AF when comparing to young animals. This study aimed to verify our hypothesis that susceptibility of aged heart to AF may be attributed to abnormalities in myocardial connexin-43 (Cx43) and extracellular matrix that affect cardiac electrical properties. Experiments were conducted on male and female 4-week-old and 24-week-old GPs. Atrial tissue was processed for analysis of Cx43 topology using immunohistochemistry, expression of Cx43 protein using immunobloting, and expression of mRNA of Cx43 and extracellular matrix metalloproteinase-2 (MMP-2) using real time PCR. Immunohistochemistry revealed uniform Cx43 distribution predominantly on lateral sides of the cardiomyocytes of young male and female GP atria. In contrast, non-uniform distribution, mislocalization and reduced immunolabeling of Cx43 were detected in atria of old GPs. In parallel, the atrial tissue levels of Cx43 mRNA were significantly decreased, while mRNA expression of MMP-2 was significantly increased in old versus young GPs. The changes were more pronounced in old GPs males comparing to females. Findings indicate that age-related down-regulation of atrial Cx43 and up-regulation of MMP-2 as well as disordered Cx43 distribution can facilitate development of AF in old guinea pig hearts., V. Nagibin, T. Egan Benova, C. Viczenczova, B. Szeiffova Bacova, I. Dovinova, M. Barancik, N. Tribulova., and Obsahuje bibliografii
Konečné produkty pokročilé glykace (advanced glycation end products – AGEs) hrají významnou roli v patogenezi řady chronických onemocnění a jejich komplikací, především diabetických komplikací, aterosklerózy, komplikací chronických onemocnění ledvin a neurodegenerativních onemocnění. Tyto látky vznikají neenzymatickou glykací a jejich tvorba je potencována vlivem karbonylového stresu. AGEs tvoří heterogenní skupinu látek a patří mezi ně např. karboxymetyllyzin, pentozin, metylglyoxallyzin dimer, vesperlyzin, imidazolony a další. AGEs jednak modifikují proteiny a mění jejich fyzikální a chemické vlastnosti, jednak mají účinky zprostředkované přes receptory, z nichž nejznámější, ale ne jediný, je receptor RAGE (receptor pro konečné produkty pokročilé glykace). RAGE je receptor multiligandový, váže také HMGB1 (high mobility group box protein 1), S100 proteiny či amyloidové fibrily. Vazba ligand na tento receptor má za následek aktivaci řady signálních cest včetně indukce oxidačního stresu a aktivace nukleárního faktoru κB a následnou prozánětlivou odpověď v závislosti na buněčném typu. AGEs a RAGE se spolu s dalšími mechanizmy – hexosaminovou cestou, polyolovou cestou, poruchou metabolizmu lipidů, aktivací proteinkinázy C, oxidačním stresem a zánětlivou reakcí spoluúčastní v patogenezi diabetických komplikací. Terapeuticky je možné snižovat endogenní tvorbu AGEs, ovlivnit přísun AGEs do organizmu stravou a jejich absorpci ve střevě či stimulovat jejich degradaci. Klíčová slova: AGEs – diabetes mellitus – karbonylový stres – konečné produkty pokročilé glykace – oxidační stres – RAGE – receptor pro AGEs – sRAGE – zánět, Advanced glycation end products (AGEs) play an important role in the pathogenesis of chronic diseases and their complications, especially diabetic complications, atherosclerosis, complications of chronic kidney diseases and neurodegenerative diseases. These substances are formed via non-enzymatic glycation and their formation is potentiated in case of carbonyl stress. AGEs are represented by a heterogeneous group of compounds, e.g. carboxymethyllysine, pentosine, methylglyoxallysin dimer, vesperlysine, imidazolones etc. AGEs can modify proteins and so change their physical and chemical properties and can act also via specific receptors, among them RAGE (receptor for advanced glycation end products) is the best known but not the unique one. RAGE is a multiligand receptor capable to bind also HMGB1 (high mobility group box protein 1), S100 proteins or amyloid fibrils. RAGE – ligand interactions results to activation of a variety of signaling pathways including oxidative stress and activation of nuclear factor κB and subsequent proinflammatory response depending on the cell type. AGEs and RAGE together with further mechanisms – hexosamine pathway, polyol pathway, lipid metabolism disorder, activation of proteinkinase C, oxidative stress and inflammatory reaction take part in the pathogenesis of diabetic complications. Terapeuticaly it is possible to decrease endogenous formation of AGEs, influence the AGEs intake to the organism and their absorption in the intestine or stimulate their degradation. Key words: AGEs – advanced glycation end-products – carbonyl stress – diabetes mellitus – inflammation – oxidative stress – RAGE – receptor for AGEs – sRAGE, and Marta Kalousová, Tomáš Zima
Hemangiom je nejčastější primární benigní nádor páteře typu hamartomu, který nikdy nemalignizuje. V drtivé většině případů se jedná o asymptomatické solitární léze hrudní páteře jakožto náhodné nálezy radiografických vyšetření. Pouze v 1 % případů se hemangiom obratle projeví klinicky a agresivita této benigní léze pak spočívá v expanzivním chování nádorové tkáně či v důsledku patologické fraktury obratle. Klinickými příznaky potom jsou především dorzalgie, v pokročilých případech pak známky kořenové nebo míšní komprese. Radiodiagnostika je poměrně snadná, protože hemangiom obratle vykazuje zcela typické grafické příznaky, pro potvrzení diagnózy agresivního hemangiomu obratle jsou stanovena grafická kritéria. Spektrum léčebných modalit je velmi široké od konzervativní léčby přes hodně využívanou vertebroplastiku po radikální chirurgickou léčbu. Komplementárně jsou často využívány embolizační výkony, alkoholová sklerotizace a lokální radioterapie. Agresivní hemangiom obratle je poměrně velmi vzácná diagnóza. Proto zatím neexistují velké soubory či klinické studie, podle kterých by bylo možné stanovit optimální terapeutický postup., Hemangioma is the most common primary benign hamartoma type spine tumor. Malignant degeneration has never been reported. In the majority of cases, this is an asymptomatic solitary lesion of the thoracic spine found incidentally during a radiographic examination. Only 1% of cases manifests clinically and this benign lesion is considered aggressive because of the expansive nature of the tumor and because it may cause pathological fracture of the vertebrae. Clinical symptoms then include dorsalgia and either root or spinal neurological symptoms. Radiological diagnosis is relatively easy because vertebral hemangioma is associated with quite typical graphic signs; graphic criteria to confirm the diagnosis of aggressive vertebral hemangioma have been clearly defined. The range of treatment options is very wide, from conservative treatment through frequently used vertebroplasty to radical surgical treatment. Embolization procedures, alcohol sclerotherapy and local radiotherapy are often used as complementary procedures. Aggressive vertebral hemangioma is a relatively rare diagnosis, so far there are no large cohorts or clinical studies from which it would be possible to determine an optimal therapeutic approach. Key words: hemangioma – vertebroplasty – angiogenesis inhibitors – angiomatosis – propranolol The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE “uniform requirements” for biomedical papers., and R. Kostyšyn, Z. Pleskačová, V. Málek
The requirements of conservators who take care of historical monuments are that the materials for rehabilitation of old renders should have a composition as similar to the historical materials as possible and should provide improvement in durability. Fine and coarse sepiolite and synthetic zeolite pellets were chosen as additives in the development of lime mortars for conservation work, due to their unique adsorption properties providing water to the mortar system and acting as water reservoirs in conditions of low humidity. Flexural and compressive strength and the dynamic modulus of elasticity were studied at 28, 90 and 180 days of curing. Addition of both fine and coarse sepiolite and zeolite pellets caused improvement of mechanical strength of mortars, clearly evident at later ages of curing. Elasticity modulus ranged from 2.3 GPa to 3.6 GPa relating to a high deformation capability of mortars and confirming their suitability for use in conservation work., Slávka Andrejkovičová, Eduardo Ferraz, Ana L. Velosa, António S. Silva and Fernando Rocha., and Obsahuje bibliografii
Chronic airflow limitation, caused by chronic obstructive pulmonary disease (COPD) or by asthma, is believed to change the shape and the position of the diaphragm due to an increase in lung volume. We have made a comparison of magnetic resonance imaging (MRI) of diaphragm in supine position with pulmonary functions, respiratory muscle function and exercise tolerance. We have studied the differences between patients with COPD, patients with asthma, and healthy subjects. Most interestingly we found the lung hyperinflation leads to the changes in diaphragmatic excursions during the breathing cycle, seen in the differences between the maxim al expiratory diaphragm position (DPex) in patients with COPD and control group (p=0.0016) . The magnitude of the diaphragmatic dysfunction was significantly related to the airflow limitation expressed by the ratio of forced expiratory volume in 1 s to slow vital capacity (FEV 1 /SVC) , (%, p=0.0007); to the lung hyperinflation expressed as the ratio of the residual volume to total lung capacity (RV/TLC), (%, p=0.0018) and the extent of tidal volume constrain expressed as maximal tidal volume (V Tmax ), ([l], p=0 .0002); and the ratio of tidal volume to slow vital capacity (VT/SVC), (p=0.0038) during submaximal exercise. These results suggest that diaphragmatic movement fails to contribute sufficiently to the change in lung volume in emphysema. Tests of respiratory muscle function were related to the position of the diaphragm in deep expiration, e.g. neuromuscular coupling (P 0.1 /VT) (p=0.0232). The results have shown that the lung volumes determine the position of the diaphragm and function of the respiratory muscles. Chronic airflow limitation seems to change the position of the diaphragm, which thereafter influences inspiratory muscle function and exercise tolerance. There is an apparent relationship between the position of the diaphragm and the pulmonary functions and exercise tolerance., L. Hellebrandová, J. Chlumský, P. Vostatek, D. Novák, Z. Rýznarová, V. Bunc., and Obsahuje bibliografii
From the very first experiments performed with high intensity laser pulse interaction with matter it has been clear that laser produced plasma is a rich source of emitting high energetic particles and electromagnetic radiation in a broad spectral range. In this article a basic phenomenon of nonlinear processes of high intensity laser pulse interaction and related acceleration of particles in laser induced thermal plasma are outlined. possible applications of ultra-short mono-energetic electron beams (with divergence and small energy spread) which are generated during this interaction are also discussed., Už od vykonania prvých experimentov použitím intenzívneho laserového žiarenia s hmotou bolo zrejmé, že laserom indukovaná plazma je bohatým zdrojom vysokoenergetických častíc a elektromagnetického žiarenia v širokej škále spektrálnych oblastí. V článku je bližšie uvedená problematika nelineárnych javov počas vysokointenzívnych laserových interakcií a s tým súvisiacu aj akceleráciu častíc v laserom indukovanej termálnej plazme. Taktiež sú uvedené aj potencionálne možné aplikácie vysokoenergetických elektrónových zväzkov, které sú generované pri týchto interakciách a dosahujú rýchlosti blízke rýchlosti svetla., Richard Viskup, Peter Lukáč., and Obsahuje bibliografii
Kolobeh hmôt v zemskéj kôre a na jej povrchu je velmi výrazne ovplyvňovaný fyzikálnymi silami, ktoré na teleso planéty pôsobia zvonku - od účinku vektorov jej vlastného pohybu, cez gravitačné pôsobenie jej obežnice - Mesiaca a blízkych planét, až po fluktuácie prísunu energie z nám najbližšej hviezdy - Slnka. Rozoznanie záznamu týchto vplyvov v horninovom slede a porozumenie im je cestou vedúcou k spresneniu astronomickej časomernej škály a detailnejšiemu poznaniu procesov formovania Zeme a života na nej., Rock cycling both in the Earth‘s crust and on its surface is impressively controlled by physical forces that act on the body of our planet from the outside, i.e. from the effect of its own motion vectors, through the gravity of the Moon and nearby planets to fluctuations in the energy input from our nearest star, i.e. the Sun. The recognition of evidence of these influences in the rock sequence and their understanding is a method used to specify the astronomical time scale and to understand, in detail, processes of formation of the Earth and indeed life on it., Jozef Michalík., and Obsahuje seznam literatury
Akromegalie patří mezi vzácná a závažná onemocnění, základem její léčby je kombinace terapie chirurgické, radiační a medikamentózní. V práci se popisuje případ akromegalie diagnostikované před 10 lety ve stadiu, v němž byla možná již jen parciální resekce hypofyzárního tumoru. Přesto se podařilo dosáhnout dlouhodobé stabilizace stavu kombinací opakovaného chirurgického zákroku, radioterapie lineárním urychlovačem i Leksellovým gama nožem a medikamentózní léčby somatostatinovým analogem oktreotidem a blokátorem receptorů pro růstový hormon pegvisomantem. Dávka oktreotidu i pegvisomantu byla opakovaně měněna podle výsledků vyšetření hladiny IGF1, v současnosti je podáváno somatostatinové analogon Sandostatin LAR 30 mg jednou za 3 týdny a blokátor receptorů pro růstový hormon Somavert 20 mg denně. Přes přítomnost závažné choroby nemocný již po 10 let vede spokojený život. Náklady na finančně náročnou léčbu jsou z etického hlediska plně odůvodněné., Acromegaly is a rare and serious disease. A successful and rational therapy of acromegaly ought to combine surgery, radiotherapy and pharmacotherapy. The submitted article presents a case of acromegaly that was only diagnosed at the stage when total pituitary adenoma removal was impossible. Even so, the long-term stabilisation of the disease was reached by way of repeated surgery through transfenoidal and transcranial approach, by linear accelerator radiation therapy and Leksell Gamma Knife radiotherapy and by pharmacotherapy with somatostatin analogon octreotide and growth hormone receptor antagonist pegvisomant. The octreotide and pegvisomant dosage has been repeatedly changed according to IGF1 levels. The contemporary somatostatin analogon Sandostatin LAR 30 mg is given once every 3 weeks and the growth hormone receptor antagonist Somavert 20 mg is applied daily. Despite this serious disease, the patient has already been living contentedly for 10 years. From the ethical point of view, the financials costingness of the therapy should be considered as reasonable., and Helena Šiprová, Miroslav Souček
Akromegalie je vzácné onemocnění způsobené autonomní nadprodukcí růstového hormonu, ve většině případů hypofyzárním adenomem. Neléčená akromegalie vede ke zvýšené morbiditě a mortalitě a také zhoršené kvalitě života pacientů. Pro prognózu pacientů je proto nezbytné včasné stanovení diagnózy a časná léčba a péče o pacienty s akromegalií by měla být koncentrována do specializovaných center. Článek shrnuje současný pohled na diagnostiku a léčbu akromegalie., Acromegaly is a rare disorder caused by autonomous oversecretion of growth hormone mostly by pituitary adenoma. Untreated acromegaly leads to significantly increased morbidity and mortality and impaired quality of life. Early diagnosis and treatment is therefore essential for improvement of patients’ prognosis and management of acromegaly should be concentrated in specialized centres. Present article summarizes current view on diagnosis and treatment of acromegaly., and Michal Kršek
Because greater Akt substrate of 160 kDa (AS160) phosphorylation has been reported in insulin-stimulated skeletal muscles without improved Akt activation several hours post-exercise, we hypothesized that prior exercise would result in attenuated AS160 dephosphorylation in insulin-stimulated rat skeletal muscle. Epitrochlearis muscles were isolated from rats that were sedentary (SED) or exercised 3 h earlier (3 h postexercise; 3hPEX). Paired muscles were incubated with [3H]-2-deoxyglucose (2-DG) without insulin or with insulin. Lysates from other insulin-stimulated muscles from SED or 3hPEX rats were evaluated using AS160Thr642 and AS160Ser588 dephosphorylation assays. Prior exercise led to greater 2-DG uptake concomitant with greater AS160Thr642 phosphorylation and a non-significant trend (P=0.087) for greater AS160Ser588. Prior exercise also reduced AS160Thr642 and AS160Ser588 dephosphorylation rates. These results support the idea that attenuated AS160 dephosphorylation may favor greater AS160 phosphorylation post-exercise., E. B. Arias, H. Wang, G. D. Cartee., and Seznam literatury