Pneumatic tourniquets are widely used in pediatric extremity surgery to provide a bloodless field and facilitate dissection. This prospective study was carried out to examine possible effect of different anesthesia techniques on oxidative stress and endothelial dysfunction connected with ischemia-reperfusion injury during extremity operations at children's age. Patients were randomized into three groups of 15 patients each: general inhalational anesthesia with sevoflurane (group S), total intravenous anesthesia with propofol (group T) and regional anesthesia (group R). Venous blood samples for determination of the malondialdehyde in plasma and erythrocytes, protein carbonyl groups concentration as well as plasma nitrites and nitrates level and xanthine oxidase activity were obtained at four time points: be fore peripheral nerve block and induction of general anesthesia (baseline), 1 min before tourniquet release, 5 and 20 min after tourniquet release. This study demonstrates that total intravenous anesthesia with propofol and regional anesthesia techniques provide better antioxidant defense and reduce endothelial dysfunct ion than general inhalational anesthesia with sevoflurane during tourniquet application in pediatric extremity surgery., I. Budic ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
Roztroušená skleróza je chronické onemocnění centrálního nervového systému neznámé etiologie s projevy autoimunitního zánětu a neurodegenerace. Onemocnění je heterogenní s nepředvídatelnou prognózou. Průběh choroby lze monitorovat klinickými parametry a sledováním vývoje patologických změn na magnetické rezonanci. I když máme znalosti o efektu nově zaváděných léků na základě klinických studií, není možné předvídat jejich účinnost u konkrétního pacienta. Proto se v posledních letech prosazuje snaha najít takové laboratorní markery, které by co možná nejspolehlivěji odpověděly na otázky spojené se subklinickou aktivitou onemocnění, jeho progresí a usnadnily terapeutické rozhodnutí na základě personifikované medicíny., Multiple sclerosis is a chronic disease of the central nervous system of unknown etiology with manifestations of autoimmune inflammation and neurodegeneration. The disease is heterogeneous with an unpredictable outcome. The course of the disease can be monitored with clinical parameters as well as pathological changes on magnetic resonance imaging. Even though the effects of newly introduced drugs are known from clinical trials, it is not possible to predict their efficacy in a specific patient. Therefore, efforts have intensified over the recent years to identify laboratory markers that would as reliably as possible answer questions on subclinical disease activity, its progression and would facilitate therapeutic decisions based personalized medicine. Key words. multiple sclerosis – therapy – biomarkers The author declare he has 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 J. Piťha
The present article introduces a novel method of characterizing the macromechanical cartilage properties based on dynamic testing. The proposed approach of instrumented impact testing shows the possibility of more detailed investigation of the acting dynamic forces and corresponding deformations within the wide range of strain rates and loads, including the unloading part of stress-strain curves and hysteresis loops. The presented results of the unconfined compression testing of both the native joint cartilage tissues and potential substitute materials outlined the opportunity to measure the dissipation energy and thus to identify the initial mechanical deterioration symptoms and to introduce a better definition of material damage. Based on the analysis of measured specimen deformation, the intact and pathologically changed cartilage tissue can be distinguished and the differences revealed., F. Varga, M. Držík, M. Handl, J. Chlpík, P. Kos, E. Filová, M. Rampichová, A. Nečas, T. Trč, E. Amler., and Obsahuje bibliografii
Článek vychází ze zkušeností autora, který se po dlouhé praxi ve výuce mechaniky a výzkumu v oboru fyziky polymerů nyní převážně zabývá biomechanikou. Impresionistickou metodou se snaží na několika příkladech ukázat, jak vidí úlohu mechaniky a především mechaniky kontinua a reologie v biomechanice. Zabývá se i otázkou vzájemných vztahů různých profesí v multidisciplinárním oboru. Úlohu mechaniky v biomechanice vidí především v co nejhlubším pochopení fyzikální podstaty biologických dějů a jejich co nejadekvátnějším vyjádřením v rámci fyziky, kterou je však často nutno užívat ve formě podstatně složitější, než je fyzika středoškolská., This article is based on the author's experiences as both a university lecturer of mechanics and a researcher in polymer physics working now in biomechanics. The impression of the role of mechanics in biomechanics is shown on several examples taken mainly from the author's experience. The interrelations of different processes engaged in the multidisciplinary biomechanics are also discussed. The role of mechanics in biomechanics is seen in deep physical understanding of the solved problem and in adequate physical interpretation of the gained results. As the biomechanical problems are often very difficult to solve, the more general physics that is that taught at grammar schools must be used. The physician's knowledge of the human body functions are so deep that only the main features of the knowledge may be expressed in physical terms even if very advanced theories are used., Antonín Havránek., and Obsahuje bibliografii
In model experíments with isolated water-soluble proteins of chloroplasts the interaction of acetylcholinesterase (AChE) with ribulose-l,5-bisphosphate carboxylase (RuBPC), plastocyanin (PC), cytochrome / (cyt f) and ferredoxin (Fd) was studied. The acetylthiocholine (AThCh) hydrolysis by AChE was stimulated by other proteins by 20-200 %. Maximal effect was observed after the addition of PC. AChE itself did not affect redox capability of the electron transport carriers. The RuBPC activity was inhibited by 70 % on the AChE increase in the reaction medium. The level of inhibition was higher in the presence of the AChE inhibitors physostigmine and neostigmine, as well as the catecholamine noradrenaline. Biomediators acetylcholine (ACh), noradrenaline, adrenaline and the anticholinesterase drugs neostigmine and physostigmine slightly (by 5-20 %) inhibited the C02-fixing enzyme activity. Mutual regulation of AChE and RuBPC may exist in chloroplasts.
Pro řadu biomedicínských aplikací je zásadní interakce mezi biologickým prostředím a povrchem pevné látky. Diamant jako materiál sdružuje v tomto ohledu výborné polovodičové, mechanické, chemické i biologické vlastnosti a lze ho připravovat synteticky i na velké plochy. Zde ukazujeme, jaký vliv má atomární zakončení povrchu diamantu na uspořádání proteinů a buněk a jak toto biologické rozhraní naopak ovlivňuje jeho elektronické vlastnosti. Dosažené poznatky jsou přínosné pro využití unikárních vlastností diamantu v medicíně a dalších oborech., Understanding interactions between the biological environment and solid state surfaces is crucial for a wide range of biomedical applications. In this context, diamond as a material merges excellent semiconducting, mechanical, chemical as well as biological properties and it can be prepared synthetically even at large areas. here we show how atomic termination of diamond surfaces inluences arrangement of proteins and cells and how such biological interface influences electronic properties of diamond. Attained knowledge is fundamental for employing diamond unique properties in medicine and other fields., Bohuslav Rezek, Egor Ukraintsev, Marie Krátká, Alexander Kromka, Antonín Brož, Marie Kalbáčová., and Obsahuje bibliografii
Biometric data are typically used for the purposes of unique identification of a person. However, recent research suggests that biometric data gathered for the purpose of identification can be analysed for extraction of additional information. This augments indicative value of biometric data. This paper illustrates the range of augmented indicative values of the data as well as identifies crucial factors that contribute to increased vulnerability of data subjects., Alžběta Krausová, Hananel Hazan, Ján Matejka., and Obsahuje bibliografické odkazy
Diabetes is a recognized risk factor of heart disease. The abnormalities related to a decreased heart performance probably arise at cellular and molecular levels already in the asymptomatic phase of diabetes. However, the early alterations initiating a sequence of events that culminates in the clinical signs have not been fully elucidated yet. This review deals with some biophysical methods applied to investigation of left ventricular myocytes in rats with streptozotocin diabetes, as well as our most important findings concerning diabetes-induced cell changes which cannot be captured by other techniques. The observed decrease in sarcolemmal membrane fluidity is causatively associated with increased glycation and glycoxidation. On the other hand, an increase in the mitochondrial membrane fluidity may be attributed to augmented energy transduction through the membranes. We reported for the first time concurrent measurements of membrane potential and dynamics, and respiratory chain activities in rat heart mitochondria, as well as calcium transients in the myocytes from diabetic hearts together with the assessed quantitative relationships among these variables. We were able to detect some significant alterations that may underlie myocyte dysfunction and subsequent remodeling of the heart. We suppose that not all these changes reflect mechanisms leading to pathology; some may represent adaptive and compensatory responses to diabetes., I. Waczulíková ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
Projekt Centra kompetence BIORAF se již třetím rokem zabývá biorafinačními procesy, které se zakládají na chemické, biologické a termické přeměně přírodních materiálů z odpadů rostlinného a živočišného původu ze zemědělské výroby i potravinářského průmyslu či z řas na žádané produkty s vysokou přidanou hodnotou. Projekt se řeší s finanční podporou Technologické agentury ČR za koordinace Ústavu chemických procesů AV ČR a ve spolupráci s Vysokou školou chemicko-technologickou, Botanickým ústavem AV ČR a společnostmi Agra, Rabbit, Briklis a Ecofuel. Viz také První rok Centra BIORAF a Aplikace biorafinací. and Olga Šolcová.
Globally, water deficit is one of the major constraints in chickpea (Cicer arietinum L.) production due to substantial reduction in photosynthesis. Photorespiration often enhances under stress thereby protecting the photosynthetic apparatus from photoinhibition. Application of bioregulators is an alternative to counter adverse effects of water stress. Thus, in order to analyze the role of bioregulators in protecting the photosynthetic machinery under water stress, we performed an experiment with two contrasting chickpea varieties, i.e., Pusa 362 (Desi type) and Pusa 1108 (Kabuli type). Water deficit stress was imposed at the vegetative stage by withholding water. Just prior to exposure to water stress, plants were pretreated with thiourea (1,000 mg L-1), benzyladenine (40 mg L-1), and thidiazuron (10 mg L-1). Imposed water deficit decreased relative water content (RWC), photosynthetic rate (P N), quantum efficiency of PSII (Fv/Fm), and enhanced lipid peroxidation (LPO). However, bioregulator application maintained higher RWC, P N, Fv/Fm, and lowered LPO under water stress. Expression of Rubisco large subunit gene (RbcL) was low under water stress both in the Kabuli and Desi type. However, bioregulators strongly induced its expression. Although poor expression of two important photorespiratory genes, i.e., glycolate oxidase and glycine decarboxylase H subunit, was observed in Desi chickpea under imposed stress, bioregulators in general and cytokinins in particular strongly induced their expression. This depicts that the application of bioregulators protected the photosynthetic machinery by inducing the expression of RbcL and photorespiratory genes during water deficit stress., T. V. Vineeth, P. Kumar, G. K. Krishna., and Obsahuje seznam literatury