Glycerol-3-phosphate oxidation in brown adipose tissue mitochondria of cold-adapted hamster is strongly inhibited by phospholipase A2 (PLA2)- Our data show that the glycerol-3-phosphate branch of the respiratory chain is sensitive to PLA2 action more than the succinate branch and that the transfer of reducing equivalents from the glycerol-3-phosphate dehydrogenase to arteficial electron acceptor is especially sensitive to the PLA2 action.
We studied the relationships between the degree of photoautotrophy, photosynthetic capacity, and extent of photoinhibition of Gardenia jasminoides Ellis plantlets in vitro. Two successive micropropagation stages (shoot multiplication and root induction), and three culture conditions [tube cap closure, photosynthetic photon flux density (PPFD), and sucrose concentration] which may influence the development of photoautotrophy in vitro were assayed. The ratios of variable chlorophyll fluorescence to either maximal (Fv/Fm) or ground (Fv/F0) values were low, irrespective of the culture stage or growing conditions. Incomplete development of the photosynthetic apparatus and permanent photoinhibition may be involved. However, Fv/Fm and Fv/F0 increased from shoot multiplication to root induction owing to a decrease in F0 and an increase in Fm. This suggests that photoinhibition decreases later during micropropagation, when the photoautotrophy of plantlets is more advanced. The low sucrose content and high PPFD increased the photoinhibition of plantlets, whereas growth in tubes with permeable caps showed the opposite effect. The only culture factor with a significant (positive) effect on maximum photosynthetic rate (Pmax) was PPFD. At shoot multiplication net photosynthetic rate (PN) was positively correlated with the half time of the increase from F0 to Fm (t1/2). Such association may be mainly due to a common response of both traits to higher PPFD in culture. Within each culture stage, no relationship was observed between PN and the degree of photoautotrophy, which was positively correlated with Fv/Fm and Fv/F0 during root induction. During shoot multiplication, these correlations were not significant, or were even negative. Hence during the last stage of micropropagation, plantlets with a higher degree of photoautotrophy are less photoinhibited, whereas they do not follow this pattern at the earlier stage. and M. D. Serret ... [et al.].
The optimum temperature for photosynthetic CO2 assimilation of A. mangium phyllodes was 30-32 °C. Photosystem 2 (PS 2) exhibited high tolerance to high temperature. Gas exchange and the function of PS2 of A. mangium were adapted to the temperature regime of the tropical environment and this might be the contributing factor to their fast growth under tropical conditions. and Hua Yu, Bee-Lian Ong.
10-d-old pea plants {Pisum sativum L. cv. Ran 1) were treated for 24 h with proline (10-6 M oř 10*5 M) before salinization with 50 mM NaCl for 2 d. Salt stress resulted in an increase of endogenous ffee proline content, CO2 compensation concentration, photorespiration and glycollate oxidase activity; net photosynthetic rate (P^) was inhibited, but dark respiration rate (Pp) was not affected. •‘♦CO2 fixation by protoplasts isolated from salt stressed plants was inhibited by 60 %, however, the *‘*C02 fixation by protoplasts, isolated firom plants treated with proline before salinization, was only slightly reduced by NaCl. Proline alleviated the inhibitory effect of NaCl in a concentration-depending manner. Pre-treatment with proline decreased Na+ and CP accumulation in the shoot; the root content of these ions was increased.
The aim of the present study was to investigate the reflection of psychoemotional stress in the body surface potential distribution as documented by isointegral maps of cardiac activation and recovery. In 72 young men (18.3 ± 7.3 y.) with no cardiovascular history body surface potential maps (BSPMs) at rest and during the test of mental arithmetic were recorded. The digitalized data for each point of the QRS, STT and QRST integral maps, for each subject in both situations, were processed and evaluated by methods of univariate as well as spatial mathematical and statistical modeling. The results showed during MA a significant decrease of repolarization integral values over the sternum and
right precordium, which contributed to analogically localized decrements
also in the QRST BSM. The decrease occurred in more than 2/3 of lead points. The most pronounced changes were observed in the right precordial area, where potentials decreased in more than in 70 % of subjects. In conclusion, the discriminative power of the difference STT and QRST integral maps was strong enough to distinguish the mental arithmetic induced changes in the superficial cardiac electric field. These adrenergic transient alterations in ventricular recovery may be of importance in subjects at risk for ventricular arrhythmias.
Protective effect of quercetin, a natural antioxidant compound, on hypericin-induced cytotoxicity was studied in human promyelocytic leukemia cells (HL-60). Hypericin (10-5 mol.l-1) alone significantly decreased cell survival to 21 % that found in the controls, whereas in combination with quercetin (10-5 mol.l-1) this decrease was diminished to 46 %. Lower concentrations of quercetin had no protective effect. These findings indicate that oxygen radicals can play an important role in hypericin-induced phototoxic effects., A. Miroššay, H. Onderková, L. Mirossay, M. Šarišský, J. Mojžiš., and Obsahuje bibliografii
Non-alcoholic fatty liver disease (NAFLD) is an important cause of liver-related morbidity and mortality. The aim of this work was to establish and characterize a nutr itional model of NAFLD in rats. Wistar or Sprague-Dawley male rats were fed ad libitum a standard diet (ST-1, 10 % kcal fat), a medium-fat gelled diet (MFGD, 35 % kcal fat) and a high-fat gelled diet (HFGD, 71 % kcal fat) for 3 or 6 weeks. We examined the serum biochemistry, the hepatic malondialdehyde, reduced glut athione (GSH) and cytokine concentration, the respiration of liver mitochondria, the expression of uncoupling protein-2 (UCP-2) mRNA in the liver and histopathological samples. Feeding with MFGD and HFGD in Wistar rats or HFGD in Sprague-Dawley rats induced small-droplet or mixed steatosis without focal infl ammation or necrosis. Compared to the standard diet, there were no significant differences in serum biochemical parameters, except lower concentrations of triacylglycerols in HFGD and MFGD groups. Liver GSH was decreased in rats fed HFGD for 3 weeks in comparison with ST-1. Higher hepatic malondialdehyde was found in both strains of rats fed HFGD for 6 weeks and in Sprague-Dawley groups using MFGD or HFGD for 3 weeks vs. the standard diet. Expression of UCP-2 mRNA was increased in Wistar rats fed MFGD and HFGD for 6 weeks and in Sprague-Dawley rats using HFGD for 6 weeks compared to ST-1. The present stud y showed that male Wistar and Sprague-Dawley rats fed by HFGD developed comparable simple steatosis without signs of progression to non-alcoholic steatohepatitis under our experimental conditions., O. Kučera ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
b1_The purpose of this study was to assess the influence of aerobic training on the left ventricular(LV) systolic function. Thirty patients with stable coronary artery disease, who had participated in the conducted 3-month physical training, were retrospectively divided into 2 co horts. While patients in the cohort I(n=14) had continued training individually for 12 months, patients in the cohort II(n=16) had stopped training after finishing the conducted program. Rest and stress dobutamine/atropine echocardiography was performed in all patients before the training program and 1 year later. The peak systolic velocities of mitral annulus (Sa) were assessed by tissue Doppler imaging for individual LV walls. In addition, to determine global LV systolic longitudinal function, the four-site mean systolic velocity was calculated (Sa glob). According to the blood supply, left ventricular walls were divided into 5 groups: A-walls supplied by nonstenotic artery; B-walls supplied by coronary artery with stenosis ≤ 50 %; C-walls supplied by coronary artery with stenosis 51-70 %; D-walls with stenosis of supplying artery 71-99 %; and E-walls with totall y occluded supplying artery. In global systolic function, the follow-up values of Sa glob in cohort I were improved by 0.23±0.36 as compared with baseline values at rest, and by 1.26±0.65 cm/s at the maximal load, while the values of Sa glob in cohort II were diminished by 0.53±0.22(p=NS), and by 1.25±0.45 cm/s(p<0.05), respectively. Concerning the resting regional function, the only significant difference between cohorts in follow-up changes was found in walls E:0.37±0.60 versus -1.76± 0.40 cm/s(p<0.05). At the maximal load, the significant difference was found only in walls A(0.16±0.84 versus -2.67±0.87 cm/s; p<0.05)., b2_Patients with regular 12-month physical activity improved their global left ventricle systolic function mainly due to improvement of contractility in walls supplied by a totally occluded coronary artery., R. Panovský ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
We tested risperidone and ritanserin, serotonin-S2 receptor antagonists, for their effects on in vitro polyclonal IgG and IgM synthesis by human peripheral blood mononuclear cells (PBMC) stimulated with pokeweed mitogen (PWM). On the basis of the previously reported effect on immune function in vivo risperidone in this study was tested in three different groups of PBMC: healthy donors as well as schizophrenic patients before risperidone treatment and schizophrenic patients after the treatment with risperidone. IgG and IgM production after 7 days of culture was measured by ELISA. Risperidone decreased IgG synthesis (p<0.05) in PBMC of healthy subjects only at the highest concentration (10~6 M) and IgG synthesis enhanced by 5-HT was antagonized by risperidone. This effect, however, was not statistically significant. Neither risperidone nor ritanserin, in the concentration range 10-8- 10~6M, affected IgM synthesis in this group. Risperidone did not affect the production of IgG and IgM by PBMC of schizophrenic subjects in PWM-stimulated cultures both before and after risperidone therapy. The spontaneous production of IgG in PBMC of schizophrenic subjects before therapy was decreased (p<0.05) at concentrations 10-6-10~7 M of risperidone. We conclude that risperidone and ritanserin did not increase polyclonal IgG and IgM synthesis in vitro in contrast to neuroleptics currently used in clinical practice.
Diabetes mellitus is associated with a number of prothrombotic abnormalities, and correction of these abnormalities might translate into the reduction of cardiovascular risk. Glitazones improve endothelial function and reduce inflammation, but much less is known about their effect on thrombogenic factors. We have therefore studied the effect of rosiglitazone on leukocyte and soluble thrombogenic markers in patients with type 2 diabetes mellitus. Thirty-three subjects with type 2 diabetes and 32 normal controls were included; patients were examined at baseline and after 5 months of rosiglitazone treatment (4 mg/day). We measured leukocyte-platelet aggregates and leukocyte expression of either P-selectin glycoprotein ligand 1 (PSGL-1) or receptor for urokinase-type plasminogen activator (uPAR) using flow cytometry, as well as several circulating soluble thrombogenic markers by ELISA method. Leukocyte expression of uPAR and PSGL-1 was significantly higher in patients than in controls. Leukocyte-platelet aggregates and leukocyte expression of uPAR and PSGL-1 significantly decreased after rosiglitazone. There was also significant decrease in CRP and fibrinogen levels, but there was no effect of diabetes and/or rosiglitazone on other circulating molecules. In conclusions, we observed a substantial improvement in the expression of thrombogenic markers on leukocytes after rosiglitazone treatment, suggesting the novel antithrombotic effects of rosiglitazone., H. Svobodová ... [et al.]., and Obsahuje seznam literatury