Severoameričtí raci (např. rak pruhovaný a rak signální vyskytující se i v ČR) jsou příkladem invazních živočichů, jejichž invazní potenciál je zesílen přenosem onemocnění nebezpečného pro příbuzné druhy z jiných geografických oblastí. Původcem nemoci, tzv. račího moru, je Aphanomyces astaci ze skupiny Oomycetes způsobující úhyny celých populací evropských raků. Račí mor se v Evropě vyskytuje už od 19. století a i v současnosti zůstává přes intenzívní výzkum jedním z nejvýznamnějších faktorů ohrožujících původní raky (u nás jde o raka říčního a raka kamenáče, u nichž bylo jen od roku 2004 zaznamenáno deset případů zdecimování populací touto nemocí)., North American crayfish species such as the Spiny-cheek Crayfish and the Signal Crayfish are examples of invasive animals with an ability to carry and transmit a disease lethal to their relatives from other parts of the world. The disease called the crayfish plague and caused by Aphanomyces astaci (Oomycetes) may eradicate whole populations of the indigenous European crayfish. The disease is known in Europe from the 19th century and despite intensive research it is still one of the main factors endangering indigenous crayfish., and Eva Kozubíková-Balcarová.
Ačkoli bylo světélkování u hub doloženo již ve starověku, intenzivnějšího vědeckého studia se tomuto jevu dostává teprve v posledních letech. Článek shrnuje naše dosavadní poznání bioluminiscence u hub z hlediska evolučního, ekologického i fyziologického. Jeho součástí jsou i fotografie dvou tropických druhů se světélkujícími plodnicemi - Mycena chlorophos a Filoboletus manipularis., Bioluminescence in fungi was first observed in the Archaic period or earlier, but it has only recently been studied scientifically. This paper sums up our knowledge on this phenomenon from evolutionary, ecological, and physiological points of view. Included are photos of two tropical species with luminescent fruiting bodies - Mycena chlorophos and Filoboletus manipularis., and Michal Sochor, Zuzana Egertová.
Obesity is a strong cardiometabolic (CM) risk factor in children. We tested potential CM risk in obese/overweight children and the effect of an intensive lifestyle intervention using newer CM markers: atherogenic index of plasma AIP [Log(TG/HDL-C)], apoB/apoAI ratio and a marker of insulin resistance HOMA-IR. The participants (194 girls, 115 boys, average age 13) were enrolled in an intensive, one-month, inpatient weight reduction program. The program consisted of individualised dietary changes and the exercise program comprised aerobic and resistance training. Anthropometrical and biochemical parameters in plasma and CM risk biomarkers - (AIP, apoB/apoAI ratio and HOMA-IR) were examined before and after the intervention. AIP and HOMA-IR significantly correlated with BMI while apoB/apoAI ratio did not. Only AIP and HOMA-IR showed systematic increases according to the level of obesity by BMI quartiles. Lifestyle intervention significantly improved anthropometrical and biochemical values and the biomarkers too. The response of lipid parameters to the intervention was considerably higher in boys than in girls. The children were stratified into three risk categories according to AIP, where 13.8 % of boys and 5.3 % of girls fell into high risk category. The monitored biomarkers may complement each other in the prognosis of CM risk. AIP was strongly related to obesity and to lipid and glycid metabolism, while the relationship of the apoB/apoAI ratio to obesity and glycid metabolism was not significant. The obese children benefited from the intensive lifestyle intervention which improved the anthropometrical and biochemical parameters and CM risk biomarkers., M. Vrablík, M. Dobiášová, L. Zlatohlávek, Z. Urbanová, R. Češka., and Obsahuje bibliografii
Primary graft dysfunction (PGD) is a life-threatening complication among heart transplant recipients and a major cause of early mortality. Although the pathogenesis of PGD is still unclear, ischemia/reperfusion injury has been identified as a predominant factor. Both necrosis and apoptosis contribute to the loss of cardiomyocytes during ischemia/reperfusion injury, and this loss of cells can ultimately lead to PGD. The aim of our prospective study was to find out whether cell death, necrosis and apoptosis markers present in the donor myocardium can predict PGD. The prospective study involved 64 consecutive patients who underwent orthotopic heart transplantation at our institute between September 2010 and January 2013. High-sensitive cardiac troponin T (hs-cTnT) as a marker of minor myocardial necrosis was detected from arterial blood samples before the donor’s pericardium was opened. Apoptosis (caspase-3, active + pro-caspase-3, bcl-2, TUNEL) was assessed from bioptic samples taken from the right ventricle prior graft harvesting. In our study, 14 % of transplant recipients developed PGD classified according to the standardized definition proposed by the ISHLT Working Group. We did not find differences between the groups in regard to hs-cTnT serum levels. The mean hs-cTnT value for the PGD group was 57.4±22.9 ng/l, compared to 68.4±10.8 ng/l in the group without PGD. The presence and severity of apoptosis in grafted hearts did not differ between grafts without PGD and hearts that subsequently developed PGD. In conclusion, our findings did not demonstrate any association between measured myocardial cell death, necrosis or apoptosis markers in donor myocardium and PGD in allograft recipients. More detailed investigations of cell death signaling pathways in transplanted hearts are required., O. Szarszoi, J. Besik, M. Smetana, J. Maly, M. Urban, J. Maluskova, A. Lodererova, L. Hoskova, Z. Tucanova, J. Pirk, I. Netuka., and Obsahuje bibliografii
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
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.