Hemorrhagic shock (HS) represents an acute event with high mortality. The optimal combination of anesthetics that would prevent hemodynamic collapse and allow damage control surgery has not yet been determined. We tested the hypothesis that a combination of dissociative anesthetic ketamine with alpha2- agonist medetomidine (MK group, n=10) would provide superior hemodynamic control compared to propofol-remifentanil (PR group, n=10) during HS in minipigs. A modified Wiggers‘ model of HS with a target mean arterial pressure (MAP) of 40 mm Hg and 2 h duration was used. All minipigs survived. HS led to a ~50 % decrease in cardiac output in both groups (P<0.001 for baseline vs. HS 120 min) with no differences between groups. Total volume of removed blood was larger in the MK group (1321±133 ml vs. 1111±246 ml in the PR group, respectively; P<0.05). MAP was higher during the initial phases of HS in the MK group than in PR group (P<0.05 at HS 30-90 min). HR was lower in the MK group at the late phases of HS (P<0.05 at HS 60-120 min). In conclusion, medetomidine-ketamine provides a feasible and possibly a more favorable alternative to the propofol-remifentanil combination in our model of HS in minipigs., A. Brezina ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
Současné studie naznačují možnou důležitou úlohu melatoninu v Huntingtonově nemoci (HN) a jeho možné terapeutické využití při léčbě této nemoci. HN je dědičné neurodegenerativní onemocnění, které doprovází snižování hladiny melatoninu s postupem onemocnění. U normálních (nenádorových) buněk působí melatonin antiapoptoticky díky svým antioxidačním vlastnostem a schopnosti zabránit aktivaci proteinu p53. Dále melatonin zvyšuje expresi BDNF (brain derived neurotrophic factor) a dalších neuroprotektivních faktorů. Cílem této studie bylo stanovit netoxickou dávku melatoninu pro primární kožní fibroblasty izolované z transgenních miniprasat pro N‑koncovou část lidského mutovaného huntingtinu (TgHD) a popsat efekt tohoto ošetření na tyto buňky vystavené genotoxickému stresu. Buňky byly kultivovány v médiu obohaceném různými dávkami melatoninu. Analýzou proliferačních křivek získaných mikroskopováním živých buněk v pravidelných časových intervalech jsme stanovili efekt různých koncentrací melatoninu.Ukázali jsme, že vyšší dávky melatoninu jsou pro primární prasečí buňky toxické. Je zajímavé, že TgHD buňky byly oproti kontrolním buňkám více citlivé k tímto dávkám melatoninu. Stanovili jsme efektivní dávku melatoninu a současně jsme ukázali její efekt na proliferaci u buněk vystavených genotoxickému stresu. Klíčová slova: Huntingtonova choroba – melatonin – mikroskopie buněk v čase – miniprasečí model –proliferační křivky – kožní fibroblasty Autoři deklarují, že v souvislosti s předmětem studie nemají žádné komerční zájmy. Redakční rada potvrzuje, že rukopis práce splnil ICMJE kritéria pro publikace zasílané do biomedicínských časopisů., According to the recent studies, melatonin might play an important role in Huntington’s disease (HD) and act as a novel therapeutic approach in the treatment of the disease. HD, the inherited neurodegenerative disorder, is accompanied by gradual melatonin reduction as it progresses. Melatonin in normal cells (non‑tumor) has the anti‑apoptotic ability due to its antioxidant property and its ability to prevent the activation of p53. Furthermore, melatonin increases the expression of BDNF (brain derived neurotrophic factor) and other neuroprotective factors. The aim of this study was to evaluate the nontoxic dose of melatonin for primary skin fibroblasts isolated from minipigs transgenic for the N‑terminal part of human mutated huntingtin (TgHD), and the effect of melatonin treatment to these cells exposed to genotoxic stress. Cells were cultured in medium supplemented with different doses of melatonin. Using time lapse microscopy, we estimated the effect of decreasing melatonin concentrations by analyzing the proliferation curves. We show that higher doses of melatonin are toxic for primary porcine fibroblasts. Interestingly, TgHD cells were more sensitive to these doses of melatonin treatment than wild type cells. We evaluated the effective dose of melatonin and demonstrated its rescue proliferative effect on porcine primary cells exposed to genotoxic stress., and P. Rausova, J. Valasek, Z. Ellederová, J. Motlik
Introduction: We studied influence of mud-bath on bone status in male Wistar rats with subchronic arthritis. Methods: Arthritis was induced by 2 subplantar injections of Freund’s adjuvans with heat-killed Streptoccocus pyogenes into paw. Groups: intact (int) on chippings; (con) arthritis on chippings; (san38) arthritis on hot sand; (mu38) arthritis on hot mud; (mu21) arthritis on mild mud. Bone mineral density (BMD, g/cm2) was measured by dual energy X-ray absorptiometry and femurs were tested biomechanically. Bone markers osteocalcin (OC), PINP and CTX were analysed in bone. Results: BMD of right femur decreased vs. left in san38 (p = 0.030) and mu38 (p = 0.047). Fracture load of right/left femur (N) decreased in experimental groups, significantly in san38 (p = 0.05). Fracture threshold of neck decreased in right vs. left in experimental groups, but significantly in san38 (p = 0.05). OC decreased in mu38 vs. con (1.84 ± 0.14/2.62 ± 0.23). PINP decreased in int vs. san38 (p = 0.005) and mu21 (p < 0.001). CTX decreased in int vs. mu38 (p = 0.006) and mu21 (p = 0.005). Conclusion: The hot bath appears indifferent in relation to osteoporosis, while cold mud-bath shows good effect on bone metabolism. The cold mud-baths help to reduce arthritic inflammation and pain and thereby lead to higher mobility with positive consequence on bone., Helena Živná, Ljiljana Maric, Iveta Gradošová, Klára Švejkovská, Soňa Hubená, Pavel Živný, and Literatura 19
Type 2 diabetes (T2D) as well as cardiovascular disease (CVD) represent major complications of obesity and associated metabolic disorders (metabolic sy ndrome). This review focuses on the effects of long-chain n-3 polyunsaturated fatty acids (omega-3) on insulin sensitivity and glucose homeostasis, which are improved by omega-3 in many animal models of metabolic syndrome, but remain frequently unaffected in humans. Here we focus on: (i) mechanistic aspects of omega-3 action, reflecting also our experiments in dietar y obese mice; and (ii) recent studies analysing omega-3’s effects in various categories of human subjects. Most animal experiments document beneficial effects of omega-3 on insulin sensitivity and glucose metabolism even under conditions of established obesity and insulin resistance. Besides positive results obtained in both cross- sectional and prospective cohort studies on healthy human populations, also some intervention studies in prediabetic subjects document amelioration of impaired glucose homeostasis by omega-3. However, the use of omega-3 to reduce a risk of new-onset diabetes in prediabetic subjects still remains to be further characterized. The results of a majority of clinical trials performed in T2D patients suggest that omega-3 have none or marginal effects on metabolic control, while effectively reducing hypertriglyceridemia in these pati ents. Despite most of the recent randomized clinical trials do not support the role of omega-3 in secondary prevention of CVD, this issue remains still controversial. Combined interventions using omega-3 and antidiabetic or hypolipidemic drugs should be further explored and considered for treatment of patients with T2D and other diseases., P. Flachs, M. Rossmeisl, J. Kopecky., and Obsahuje bibliografii a bibliografické odkazy
Activation of the hypothalamic-pituitary-adrenal (HPA) axis is important for maintenance of homeostasis during stress. Recent studies have shown a connection between the HPA axis and adipose tissue. The present study investigated the effect of acute heterotypic stress on plasma levels of adrenocorticotropic hormone (ACTH), corticosterone (CORT), leptin, and ghrelin in adult male rats with respect to neonatal maternal social and physical stressors. Thirty rat mothers and sixty of their male progeny were used. Pups were divided into three groups:
unstressed control (C), stressed by maternal social stressor (S),
stressed by maternal social and physical stressors (SW). Levels of
hormones were measured in adult male progeny following an
acute swimming stress (10min) or no stress. ELISA immunoassay was used to measured hormones. The ACTH and CORT levels were significantly increased in all groups of adult progeny after acute stress; however, CORT levels were significantly lower in both neonatally stressed groups compared to controls. After acute stress, plasma leptin levels were decreased in the C and SW groups but increased in the S group. The data suggest that long-term neonatal stressors lead to lower sensitivity of ACTH receptors in the adrenal cortex, which could be a sign of stress adaptation in adulthood. Acute stress in adult
male rats changes plasma levels of leptin differently relative to social or physical neonatal stressors.
A major obstacle to the therapeutic use of anthracyclines, highly effective anticancer agents, is the fact that their administration results in dose-dependent cardiomyopathy. According to the currently accepted hypothesis, anthracyclines injure the heart by generating oxygen free radicals. The ability of pyridoxal isonicotinoyl hydrazone (PIH) and salicylaldehyde isonicotinoyl hydrazone (SIH) – new iron chelators – to protect against peroxidation as well as their suitable biological, physical and chemical properties make the compounds promising candidates for pre-clinical and clinical studies. Activities of carbonyl reductase CR (1.1.1.184), dihydrodiol dehydrogenase DD2 (1.3.1.20), aldehyde reductase ALR1 (1.1.1.2) and P450 isoenzymes (CYP1A1, CYP1A2, CYP2B, CYP3A) involved in the metabolism of daunorubicin, doxorubicin and other drugs or xenobiotics were studied. Various concentrations of the chelators were used either alone or together with daunorubicin or doxorubicin for in vitro studies in isolated hepatocytes. A significant decrease of activity was observed for all enzymes only at PIH and SIH concentrations higher than those presumed to be used for therapy. The results show that PIH and SIH have no effect on the activities of the enzymes studied in vitro and allow us to believe that they will not interfere with the metabolism of co-administered drugs and other xenobiotics. Daunorubicin (Da) and doxorubicin (Dx) significantly reduce cytochrome P450 activity, but the addition of SIH and PIH chelators (50 μM) reverses the reduction and restores the activity to 70-90 % of the activity of relevant controls.
In vitro models serve as a tool for studies of steatosis. Palmitic and oleic acids can induce steatosis in cultured hepatocytes. The aim of our study was to verify steatogenic and cytotoxic effects of palmitic acid (PA), oleic acid (OA) and their combinations as well as their impact on functional capacity of rat primary hepatocytes. Hepatocytes were exposed to OA or PA (0.125-2 mmol/l) or their combination at ratios of 3:1, 2:1 or 1:1 at the final concentrations of 0.5-1 mmol/l. Both OA and PA caused a dose-dependent increase in triacylglycerol content in hepatocytes. PA was more steatogenic at 0.25 and 0.5 mmol/l while OA at 0.75 and 1 mmol/l. PA exhibited a dose-dependent cytotoxic effect associated with ROS production, present markers of apoptosis and necrosis and a decrease in albumin production. OA induced a damage of the cytoplasmic membrane from 1 mM concentration. Mixture of OA and PA induced lower cytotoxicity with less weakened functional capacity than did PA alone. Extent of steatosis was comparable to that after exposure to OA alone. In conclusion, OA or combination of OA with PA is more suitable for simulation of simple steatosis than PA alone., A. Moravcová, Z. Červinková, O. Kučera, V. Mezera, D. Rychtrmoc, H. Lotková., and Obsahuje bibliografii
The effect of exercise on oxidant stress and on alterations in antioxidant defense in elderly has been investigated extensively. However, the impact of regularly performed long-term physical activity starting from adulthood and prolonged up to the old age is not yet clear. We have investigated the changes in the activities of antioxidant enzymes – superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) – and lipid peroxidation in various tissues of rats which had performed (old-trained) or had not performed (old-control) regular swimming exercise for one year. These animals were compared with young-sedentary rats. Increased lipid peroxidation was observed with ageing in all tissues (heart, liver, kidney, striated muscle) and swimming had no additional effect on this elevation of lipid peroxidation. Heart and striated muscle SOD activites, and striated muscle CAT activity increased as a consequence of ageing, whereas kidney and liver CAT activities, as well as GPx activities in kidney, liver, lung and heart were significantly decreased compared to young controls. Lung and heart SOD, liver CAT activities as well as GPx activities in liver, lung and heart were increased significantly in rats which performed exercise during ageing, compared to the old-control group. These findings suggest that lifelong exercise can improve the antioxidant defense in many tissues without constituting any additional oxidant stress.
The brain is widely responsive to gonadal hormones. The functional significance of ovarian hormones in the brain is evident from biochemical studies indicating that estradiol or progesterone treatment of testectomized rats produces changes of antioxidant enzyme activities. The effect of estradiol benzoate (EB) and progesterone (P) in the control of antioxidant (AO) enzyme activities was studied in the brain of adult male Wistar rats. The activities of catalase (CAT), glutathione peroxidase (GSH-Px), glutathione-S-transferase (GST) and glutathione reductase (GR) were measured in appropriate subcellular fractions, prepared from brains of animals belonging to various experimental groups. These groups were designed with the intention to follow changes in enzyme activities 2 h or 24 h after systemic administration of 5 g EB or 2 mg P to testectomized (TX) animals. The obtained results show that both EB and P increase CAT activity, whereas EB decreases GSH-Px, GST and GR activities. These findings clearly show the modulatory role of EB and P in the control of enzymes responsible for the protection of rat nerve cells against oxidative damage caused by free oxygen radicals., S. B. Pajović, Z. S. Saičić, M. B. Spasić, V. M. Petrović., and Obsahuje bibliografii