This study aimed to investigate whether heat stress (HS) prevents a decrease in succinate dehydrogenase (SDH) activity and heat shock protein 60 (HSP60) and superoxide dismutase 2 (SOD2) contents in the extensor digitorum longus of streptozotocin (STZ)-induced diabetic rats. Twelve-week-old male Wistar rats were assigned to one of the four groups (n=6/group): control (Con), HS, diabetes mellitus (DM), and diabetes mellitus and heat stress (DM+HS). Diabetes was induced by the administration of STZ (50 mg/kg). HS was initiated 7 days after STZ treatment and performed at 42 °C for 30 min 5 times a week for 3 weeks. SDH activity was decreased in the DM and DM+HS groups. However, SDH activity was greater in the DM+HS group than in the DM group. Although HSP60 content was lower in the DM group than in the Con group, it was maintained in the DM+HS groups and was higher than that in the DM group. SOD2 content was decreased only in the DM group. These findings suggest that HS prevents the decrease in SDH activity in the skeletal muscle induced by DM. According to this mechanism, the maintenance of SOD2 and HSP60 by HS may suppress the increase in oxidative stress., K. Nonaka, S. Une, M. Komatsu, R. Yamaji, J. Akiyama., and Seznam literatury
Positive effects of repeated administration of diclofenac, an inhibitor of prostaglandin synthesis, in terms of prevention of tumor development and stimulation of hematopoiesis have been observed in C3H mice transplanted subcutaneously with G:5:113 fibrosarcoma cells. Fourteen-day treatment with diclofenac (3.75 mg/kg/day) started from day 5 after tumor cell transplantation. Measurements of tumors and hematological examinations were performed on day 30. The results strongly suggest the possibility that inhibitors of prostaglandin synthesis (non-steroidal anti-inflammatory drugs) may be used in oncological practice where the observed effects are highly desirable., M. Hofer, Z. Hoferová, P. Fedoročko, N. O. Macková., and Obsahuje bibliografii
The use of reversible lesion techniques in memory research was pioneered in the laboratory of Jan Bureš and Olga Burešova. We use the occasion of Jan’s 75th birthday to briefly review the experimental utility of this approach. Two experiments from our current research are reported in which reversible lesioning methods are used to ask otherwise experimentally untenable questions about memory retrieval. The first experiment used intra-hippocampal injections of tetrodotoxin to temporarily inactivate the hippocampus during retrieval of a well-learned place avoidance navigation memory. This revealed that the hippocampus is necessary for place avoidance retrieval but that the extinction of place avoidance can occur independently of retrieving the memory and intact hippocampal function. The second experiment used KCl-induced cortical spreading depression in an interhippocampal transfer paradigm to demonstrate that a Y-maze memory that is learned by only one cortical hemisphere can be made to transfer to the other hemisphere by forcing the rat to swim, a unique stressful experience that occurred in a different apparatus, different behavioral context, and involved different behaviors than the Y-maze training. This demonstrates, we believe for the first time behaviorally, that memories can be activated outside of the behavioral context of their acquisition and expression in rats., K. Ježek, M. Wesierska, A. A. Fenton., and Obsahuje bibliografii
Bretschneider (histidine-tryptophan-ketoglutarate) solution with its high histidine concentration (198 mM) is one of many cardioplegic solutions, which are routinely used for cardiac arrest. The aim of this study was to evaluate the physiological biochemical degradation of administered histidine to histamine and its major urinary metabolite N-methylimidazole acetic acid. A total number of thirteen consecutive patients scheduled for elective isolated coronary artery bypass grafting with cardiopulmonary bypass were enrolled in the prospective observational designed study at the Department of Thoracic and Cardiovascular Surgery between 04/2016 and 06/2016. Patients received 1.7 l Bretschneider solution on average. Before and at the end of operation as well as in the postoperative course, urine samples gathered from the urinary catheter bag were analyzed. During the operative period, urinary histidine concentration significantly increased from 29 μmol/mmol creatinine to 9,609 μmol/mmol creatinine. Postoperatively, histidine excretion reduced while histamine as well as N-methylimidazole acetic acid excretion rose significantly. Patients showed elevated levels of histidine, histamine as well as N-methylimidazole acetic acid in urine, but no unmanageable hemodynamic instability possibly arising from the histamine’s biological properties. Chemically modified histidine might reduce uptake and metabolization while maintaining the advantages of buffer capacity., J. K. Teloh, L. Ansorge, M. Petersen, E. Demircioglu, I. N. Waack, S. Brauckmann, H. Jakob, D.-S. Dohle., and Seznam literatury
Research and clinical implications on novel cardiac biomarkers has intensified significantly in the past few years. The highsensitive troponin T (hscTnT) assay plays a dominant role in diagnostic algorithm regarding myocardial injury in adults. Despite generally accepted use of hscTnT there are no data about physiological concentrations and cut-off limits in neonates and infants to date. The aim of this study is to assess hscTnT levels in healthy newborns and infants. Consecutively 454 healthy full termed newborns and 40 healthy infants were enrolled in the study. Samples of cord or venous blood were drawn and tested for hscTnT concentrations with high-sensitive TnT assay (Roche Cobas e602 immunochemical analyzer). The 97.5 percentile of hscTnT concentration was assessed and correlation analysis was performed in neonates. Two hundred and thirteen samples (47 %) were excluded due to blood hemolysis of various degrees in neonates. Finally, the group of 241 healthy newborns was statistically analyzed. The median concentration of hscTnT was 38.2 ng/ml, 97.5 percentile reached 83.0 ng/l (confidential interval 74.1 to 106.9 ng/l). HscTnT concentrations were statistically decreased in hemolytic samples when compared to non-hemolytic samples (34.3 ng/l [26.7 to 42.0 ng/l] and 37.1 ng/l [30.5 to 47.9 ng/l], respectively, p=0.003). Elevated plasma concentrations of hscTnT decreased to adult level within six months. This study has confirmed the higher reference levels of hscTnT in neonates and young infants when compared with adult population. Many extracardiac factors as hemolysis and age may affect the hscTnT level. Based on presented results, a careful clinical interpretation of hscTnT is recommended., P. Jehlička, M. Huml, D. Rajdl, A. Mocková, M. Matas, J. Dort, A. Masopustová., and Seznam literatury
Impressive advances in molecular genetic techniques allow to analyze the effects of natural selection on the development of human genome. For example, the trend towards blonde hair and blue eyes was documented. The approach to analyze possible effects of natural selection on the evolution of recent phenotypes with high risk of cardiovascular disease has not been described yet. A possible effect on the evolution of two main risk factors - hypercholesterolemia and hypertension - is presented. The close relationship of non-HDL cholesterol blood concentration to the proportion of pro-inflammatory macrophages in human visceral adipose tissue might be a result of long-lasting natural selection. Individuals with higher proportion of this phenotype might also display a higher ability to fight infection, which was very common in human setting from prehistory until Middle Ages. Successful battle against infections increased the probability to survive till reproductive age. Similar hypothesis was proposed to explain frequent hypertension in African Americans. A long-lasting selection for higher ability to conserve sodium during long-term adaptation to low sodium intake and hot weather was followed by a short-term (but very hard) natural selection of individuals during transatlantic slave transport. Only those with very high capability to retain sodium were able to survive. Natural selection of phenotypes with high plasma cholesterol concentration and/or high blood pressure is recently potentiated by high-fat high-sodium diet and overnutrition. This hypothesis is also supported by the advantage of familial hypercholesterolemia in the 19th century (at the time of high infection disease mortality) in contrast to the disadvantage of familial hypercholesterolemia during the actual period of high cardiovascular disease mortality., R. Poledne, J. Zicha., and Seznam literatury
To determine whether changes in partial pressure of CO2 participate in mechanism enlarging the lung functional residual capacity (FRC) during chronic hypoxia, we measured FRC and ventilation in rats exposed either to poikilocapnic (group H, FIO2 0.1, FICO2 <0.01) or hypercapnic (group H+CO2, FIO2 0.1, FICO2 0.04-0.05) hypoxia for the three weeks and in the controls (group C) breathing air. At the end of exposure a body plethysmograph was used to measure ventilatory parameters (V´E, fR, VT) and FRC during air breathing and acute hypoxia (10 % O2 in N2). The exposure to hypoxia for three weeks increased FRC measured during air breathing in both experimental groups (H: 3.0±0.1 ml, H+CO2: 3.1±0.2 ml, C: 1.8±0.2 ml). During the following acute hypoxia, we observed a significant increase of FRC in the controls (3.2±0.2 ml) and in both experimental groups (H: 3.5±0.2 ml, H+CO2: 3.6±0.2 ml). Because chronic hypoxia combined with chronic hypercapnia and chronic poikilocapnic hypoxia induced the same increase of FRC, we conclude that hypercapnia did not participate in the FRC enlargement during chronic hypoxia., H. Maxová, M. Vízek., and Obsahuje bibliografii
The aim of the study was to compare the effect of short-term hyperglycemia and short-term hyperinsulinemia on parameters of oxidative stress in Wistar rats. Twenty male rats (aged 3 months, average body weight 325 g) were tested by hyperinsulinemic clamp (100 IU/l) at two different glycemia levels (6 and 12 mmol/l). Further 20 rats were used as a control group infused with normal saline (instead of insulin) and 30 % glucose simultaneously. Measured parameters of oxidative stress were malondialdehyde (MDA), reduced glutathione (GSH) and total antioxidant capacity (AOC). AOC remained unchanged during hyperglycemia and hyperinsulinemia. Malondialdehyde (as a marker of lipid peroxidation) decreased significantly (p<0.05) during the euglycemic hyperinsulinemic clamp, and increased significantly during isolated hyperglycemia without hyperinsulinemia. Reduced glutathione decreased significantly (p<0.05) during hyperglycemia without hyperinsulinemia. These results suggest that the short-term exogenous hyperinsulinemia reduced the production of reactive oxygen species (ROS) during hyperglycemia in an animal model compared with the control group., P. Kyselová, M. Žourek, Z. Rušavý, L. Trefil, J. Racek., and Obsahuje bibliografii
Immunity plays an important role in the reactivity of the organism and, in this context, is an essential factor in the pathogenesis of many diseases. Basically, there is no system or organ in the body, whose dysfunction is not related to immunity consequences. In addition, there are also multisystem diseases simultaneously involving multiple body systems. They are not always caused by weak immunity, but also often by modified immune reactions known as overshooting. The essence of all these diseases is a change in the reactivity of the organism where immunity plays an important role. The immunity as such is then part of the systems of neuroendocrine-immune regulation, which have common mediators and receptors. The establishment of psychoneuroimmunology, a relatively new discipline in neuroscience, contributed to a detailed understanding of these mechanisms between central and peripheral nervous system, the endocrine system and the immune system. This research enabled the uncovering of the nature of stress-diseases and impact of other regulatory disturbances on the function of various body organs and systems of the organism as a whole. The aim of this short review is to show complex interconnections of these relationships to better understand the human health and disease., F. Vožeh., and Seznam literatury
The electrical parameters of the cell membrane are mostly estimated employing ac methods. The measurement is based on the analysis of the current(s) flowing through an access resistance and the membrane. A current/potential transducer is used at the input of the device. The parameters of this transducer, especially its feedback capacity, degrades the accuracy of the measurement and hence diminishes the suppression of mutual influences of the individual parameters. The paper suggests a possible software correction and is supplemented by remarks for practical application., V. Rohlíček, F. Rech., and Obsahuje bibliografii