Phenobarbital is an anticonvulsive drug widely used in newborns with hypoxic-ischemic encephalopathy. The objective of our study was to describe possible effect of frequently co-administered medications (dopamine, dobutamine, norepinephrine, furosemide, phenytoin, and analgesics) on the phenobarbital pharmacokinetics in full term newborns with hypoxic-ischemic encephalopathy. Phenobarbital pharmacokinetic parameters (standardized intravenous loading dose was 10-20 mg/kg, maintenance dose 2-6 mg/kg/day) were computed using non-compartmental analysis. Co-medication was evaluated throughout the whole treatment period up to 5 days. Volume of distribution, clearance, and half-life median values (95 % CI) for phenobarbital in the whole study population (n=37) were 0.48 (0.41-0.56) l/kg, 0.0034 (0.0028-0.0040) l/h/kg, and 93.7 (88.1-99.2) h, respectively. Phenobarbital pharmacokinetic parameters were not significantly affected by vasoactive drugs (dopamine, dobutamine, and norepinephrine), furosemide, phenytoin, or analgesics. Furthermore, no dose-dependent alteration of phenobarbital pharmacokinetic parameters was noted for vasoactive medication at doses equivalent to cumulative vasoactive-inotropic score (area under the curve in a plot of vasoactive-inotropic score against time) 143.2-8473.6, furosemide at cumulative doses of 0.2-42.9 mg/kg, or phenytoin at cumulative doses of 10.3-46.2 mg/kg. Phenobarbital pharmacokinetics was not affected by investigated co-administered drugs used in newborns with hypoxic-ischemic encephalopathy in real clinical settings., M. Šíma, P. Pokorná, K. Hronová, O. Slanař., and Obsahuje bibliografii
Activated hepatic stellate cells (HSC) are a major source offibrous proteins in cirrhotic liver. Inducing or accelerating their apoptosis is a potential way of liver fibrosis treatment. Extracellular matrix (ECM) surrounding cells in tissue affects their differentiation, migration, proliferation and function. Type I collagen is the main ECM component in fibrotic liver. We have examined how this protein modifies apoptosis of normal rat HSC induced by gliotoxin, cycloheximide and cytochalasin D in vitro and spontaneous apoptosis of HSC isolated from CCl4-damaged liver. We have found that type I collagen gel enhances HSC apoptosis regardless of the agent triggering this process. and L. Bittnerová, A. Jiroutová, E. Rudolf, M. Rezácová, J. Kanta
The aim of the present study was to evaluate the efficiency of combination of hyperbaric oxygen (HBO) and an antioxidant on permanent focal cerebral ischemia. Male Wistar rats underwent permanent middle cerebral artery occlusion (MCAO). Then, animals were randomly assigned to one of four groups: the control group (n=9) received no treatment, HBO group (n=9) was treated for 90 min at 2.5 absolute atmosphere for 3 days, the U-74389G group (n=8) received single U-74389G injection (3 mg/kg), the HBO + U-74389G group (n=8 ) received both HBO and U-74389G treatments. Treatments were initiated within the first 10 min after MCAO. After 3 days, the infarct volumes in rat brains were measured. The infarct ratios were 25.6±6.5 % for the control group, 21.9±6.4 % for the HBO group, 15.7±5.7 % for U-74389G group and 12.5±3.8 % for HBO + U74389G group. The infarct volumes were significantly reduced in rats treated with U-74389G (p< 0.05) and combination therapy (p <0.05). HBO failed to reduce infarct volume significantly. We concluded that 1) U-74389G is more beneficial than HBO on permanent MCAO in rats, and 2) a combined therapy failed to significantly improve infarct volume more than either single treatment., G. Acka, A. Sen, Z. Canakci, S. Yildiz, A. Akin, G. Uzun, H. Cermik, I. Yildirim, S. Kokpinar., and Obsahuje bibliografii a bibliografické odkazy
Changes in root topology of the tussock perennial grass Molinia caerulea were studied in a pot experiment. The target species M. caerulea was grown alone and with Holcus lanatus or Carex hartmanii as a competitor. The root topology in three different soils (sand, humus rich soil and a mixture of both) was measured. Influence of competitive pressure on root topology was determined in terms of root biomass surrounding the target root. Whereas no simple significant changes in root topology due to soil quality were observed, an increase in competition pressure caused a shift of root topology towards a more herringbone structure. This shift was greatest in nutrient poor sand and least in humus-rich soil. In addition, an influence of individual competitors on topological changes in humus-rich soil was observed after excluding the effect of total root biomass.
Ten mouflon rams were kept with their mothers in a captive regimen under natural photoperiod. Seven of the mouflon lambs received a series of subcutaneous implants containing 18 mg of melatonin (Melovine ®). The first implant was inserted at the time of birth and it was followed by implant insertion every two months to maintain plasma melatonin concentrations above basal levels. Three mouflon lambs were used as controls. Body weight, outer horn length and horn base circumference were measured weekly. Three implanted lambs maintained a poor body condition throughout the experiment and died early. In the remaining four implanted lambs, the pattern of body and horn growth was similar to controls. Horn length and base circumference were correlated (P < 0.001) with body weight in both control and melatonin-implanted mouflons. No differences between control and survivor melatonin implanted mouflons were observed in weekly body weight gain (0.86 ± 0.19 kg and 0.77 ± 0.06 kg, respectively), weekly horn length growth (0.77 ± 0.03 cm and 0.77 ± 0.02 cm, respectively) and weekly base circumference growth (0.49 ± 0.03 cm and 0.45 ± 0.03 cm, respectively).
The physiological and biochemical behaviour of rice (Oryza sativa, var. Jyoti) treated with copper (II) oxide nanoparticles (CuO NPs) was studied. Germination rate, root and shoot length, and biomass decreased, while uptake of Cu in the roots and shoots increased at high concentrations of CuO NPs. The accumulation of CuO NPs was observed in the cells, especially, in the chloroplasts, and was accompanied by a lower number of thylakoids per granum. Photosynthetic rate, transpiration rate, stomatal conductance, maximal quantum yield of PSII photochemistry, and photosynthetic pigment contents declined, with a complete loss of PSII photochemical quenching at 1,000 mg(CuO NP) L-1. Oxidative and osmotic stress was evidenced by increased malondialdehyde and proline contents. Elevated expression of ascorbate peroxidase and superoxide dismutase were also observed. Our work clearly demonstrated the toxic effect of Cu accumulation in roots and shoots that resulted in loss of photosynthesis., M. V. J. Da Costa, P. K. Sharma., and Obsahuje seznam literatury
In order to investigate the effect of day/night temperature difference (DIF) on photosynthetic characteristics of tomato plants (Solanum lycopersicum, cv. Jinguan 5) at fruit stage, an experiment was carried out in climate chambers. Five day/night temperature regimes (16/34, 19/31, 25/25, 31/19, and 34/16°C) with respective DIFs of -18, -12, 0, +12, and +18 were used and measured at mean daily temperature of 25°C. The results showed that chlorophyll (Chl) a, Chl b, net photosynthetic rate (PN), stomatal conductance (gs), maximum quantum yield of PSII photochemistry (Fv/Fm), effective quantum yield of PSII photochemistry (ϕPSII), and photochemical quenching (qp) significantly increased under positive DIF, while they decreased with negative DIF. In contrast, the Chl a/b ratio and nonphotochemical quenching (NPQ) decreased under positive DIF, while increased with negative DIF. Chl a, Chl b, PN, gs, Fv/Fm, ϕPSII, and qp were larger under +12 DIF than those at +18 DIF, while Chl a/b and NPQ showed an opposite trend., X. K. Yuan., and Seznam literatury
Large debris transported by flood affects scour features at bridge piers and increases the risks of structural failure. Geometric characteristics of the debris and the relative position of the pier with respect to the river bank are important parameters for the scour process. The interaction between the water flow and debris accumulation increases the shear stress, turbulence and consequently enhances the scour depth at the pier. This paper aims at analyzing such effects on scour evolution at bridge piers. To this end, two series of tests were carried out under clear water condition with different debris geometries and percentage blockage ratios. Experimental evidences showed that the pier position only influences scour evolution and equilibrium morphology for low water depths. Conversely, its effect becomes negligible for scour at bridge piers with debris accumulation and higher water depths. Useful practical relationships have been derived, with satisfactory prediction capability of the scour evolution for all the tested configurations.
Spectroscopy was used to investigate the fluorescence quenching mechanism in light-harvesting complex 2 (LHC2). The 77 K fluorescence excitation spectroscopy was performed for detection of aggregation state of LHC2 treated with different concentrations of octylphenol poly(ethyleneglycol ether)10 (TX-100). Resonance Raman (RR) spectra excited with 488, 496, and 514 nm provided molecular configuration of neoxanthin, lutein 1, and lutein 2, respectively. At increased concentration of TX-100, the RR signals of xanthophylls were enhanced in the four frequency regions, which was accompanied with increase of fluorescence of chlorophyll (Chl) a. Thus the absorption of the three xanthophyll molecules was inclined to excitation wavelength, which proved that functional configurations of xanthophyll molecules in LHC2 were vital for fast transfer of excitation energy to Chl a molecules. Changes in the v4 region (C-H out-of-plane bending modes, at ∼960 cm-1 in RR spectra) demonstrated that the twist feature of neoxanthin, lutein 1, and lutein 2 molecules existed in LHC2 trimers, however, it was lost in the LHC2 macro-aggregates. In the second derivative absorption spectra of LHC2, neoxanthin absorption was not detected in LHC2 macro-aggregates, while evident absorption was found in LHC2 trimers and this absorption decreased obviously when TX-100 concentration was higher than 1 mM. Hence the neoxanthin molecule had a structural role in formation of LHC2 trimers. The RR and absorption spectra also implied that carotenoid molecules constructed the functional LHC2 trimers via their intrinsic configuration features, which enabled energy transfer to Chl a efficiently and led to lower fluorescence quenching efficiency. In contrast, these intrinsic twist configurations were lost in LHC2 macro-aggregates and led to lower energy transfer efficiency and higher fluorescence quenching efficiency. and Z. H. Hu, F. Zhou, C. H. Yang.
Deuterium-depleted water (DDW) has a lower concentration of deuterium
than occurs naturally (less than 145 ppm). While effects of DDW on cancer started to be intensively studied, the effects on cardiovascular system are completely unknown. Thus, we aimed to analyze the effects
of DDW (55±5 ppm) administration to 12-week-old normotensive Wistar
-Kyoto rats (WKY) and spontaneously hypertensive rats (SHR) treated with 15 % fructose for 6 weeks. Blood pressure (BP) and selected
biochemical parameters were measured together with determination of nitric oxide synthase (NOS) activity and iNOS and eNOS protein expressions in the left ventricle (LV) and aorta. Neither DDW nor fructose had any significant effect on BP in both strains. DDW treatment decreased total cholesterol and triglyceride levels in WKY, but it was not able to prevent increase in the same parameters elevated due to fructose treatment in SHR. Both fructose and DDW increased insulin level in WKY. Fructose did not affect NOS activity either in WKY or SHR. DDW increased NOS activity in LV of both WKY and SHR, while it
decreased NOS activity and iNOS expression in the aorta of SHR with or without fructose treatment. In conclusion, DDW treatment significantly modified biochemica l parameters in WKY together with NOS activity elevation in the heart. On the other hand, it did not affect biochemical parameters in SHR, but decreased NOS activity elevated due to iNOS upregulation in the aorta.