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1.  Hydrogen peroxide functions as a secondary messenger for brassinosteroids-induced CO2 assimilation and carbohydrate metabolism in Cucumis sativus *  
Brassinosteroids (BRs) are potent regulators of photosynthesis and crop yield in agricultural crops; however, the mechanism by which BRs increase photosynthesis is not fully understood. Here, we show that foliar application of 24-epibrassinolide (EBR) resulted in increases in CO2 assimilation, hydrogen peroxide (H2O2) accumulation, and leaf area in cucumber. H2O2 treatment induced increases in CO2 assimilation whilst inhibition of the H2O2 accumulation by its generation inhibitor or scavenger completely abolished EBR-induced CO2 assimilation. Increases of light harvesting due to larger leaf areas in EBR- and H2O2-treated plants were accompanied by increases in the photochemical efficiency of photosystem II (ΦPSII) and photochemical quenching coefficient (q P). EBR and H2O2 both activated carboxylation efficiency of ribulose-1,5-bisphosphate oxygenase/carboxylase (Rubisco) from analysis of CO2 response curve and in vitro measurement of Rubisco activities. Moreover, EBR and H2O2 increased contents of total soluble sugar, sucrose, hexose, and starch, followed by enhanced activities of sugar metabolism such as sucrose phosphate synthase, sucrose synthase, and invertase. Interestingly, expression of transcripts of enzymes involved in starch and sugar utilization were inhibited by EBR and H2O2. However, the effects of EBR on carbohydrate metabolisms were reversed by the H2O2 generation inhibitor diphenyleneodonium (DPI) or scavenger dimethylthiourea (DMTU) pretreatment. All of these results indicate that H2O2 functions as a secondary messenger for EBR-induced CO2 assimilation and carbohydrate metabolism in cucumber plants. Our study confirms that H2O2 mediates the regulation of photosynthesis by BRs and suggests that EBR and H2O2 regulate Calvin cycle and sugar metabolism via redox signaling and thus increase the photosynthetic potential and yield of crops.
PMCID: PMC3468824  PMID: 23024048
Metabolism; Photosynthesis; Reactive oxygen species; Rubisco; Sucrose
2.  Effects of nitrogen form on growth, CO2 assimilation, chlorophyll fluorescence, and photosynthetic electron allocation in cucumber and rice plants*  
Cucumber and rice plants with varying ammonium (NH4 +) sensitivities were used to examine the effects of different nitrogen (N) sources on gas exchange, chlorophyll (Chl) fluorescence quenching, and photosynthetic electron allocation. Compared to nitrate (NO3 −)-grown plants, cucumber plants grown under NH4 +-nutrition showed decreased plant growth, net photosynthetic rate, stomatal conductance, intercellular carbon dioxide (CO2) level, transpiration rate, maximum photochemical efficiency of photosystem II, and O2-independent alternative electron flux, and increased O2-dependent alternative electron flux. However, the N source had little effect on gas exchange, Chl a fluorescence parameters, and photosynthetic electron allocation in rice plants, except that NH4 +-grown plants had a higher O2-independent alternative electron flux than NO3 −-grown plants. NO3 − reduction activity was rarely detected in leaves of NH4 +-grown cucumber plants, but was high in NH4 +-grown rice plants. These results demonstrate that significant amounts of photosynthetic electron transport were coupled to NO3 − assimilation, an effect more significant in NO3 −-grown plants than in NH4 +-grown plants. Meanwhile, NH4 +-tolerant plants exhibited a higher demand for the reduced form of nicotinamide adenine dinucleotide phosphate (NADPH) for NO3 − reduction, regardless of the N form supplied, while NH4 +-sensitive plants had a high water-water cycle activity when NH4 + was supplied as the sole N source.
PMCID: PMC3030957  PMID: 21265044
Nitrogen form; Photosynthetic electron allocation; Alternative electron flux; Nitrate reductase
3.  Sevoflurane postconditioning reduces myocardial reperfusion injury in rat isolated hearts via activation of PI3K/Akt signaling and modulation of Bcl-2 family proteins*  
Sevoflurane postconditioning reduces myocardial infarct size. The objective of this study was to examine the role of the phosphatidylinositol-3-kinase (PI3K)/Akt pathway in anesthetic postconditioning and to determine whether PI3K/Akt signaling modulates the expression of pro- and antiapoptotic proteins in sevoflurane postconditioning. Isolated and perfused rat hearts were prepared first, and then randomly assigned to the following groups: Sham-operation (Sham), ischemia/reperfusion (Con), sevoflurane postconditioning (SPC), Sham plus 100 nmol/L wortmannin (Sham+Wort), Con+Wort, SPC+Wort, and Con+dimethylsulphoxide (DMSO). Sevoflurane postconditioning was induced by administration of sevoflurane (2.5%, v/v) for 10 min from the onset of reperfusion. Left ventricular developed pressure (LVDP), left ventricular end-diastolic pressure (LVEDP), maximum increase in rate of LVDP (+dP/dt), maximum decrease in rate of LVDP (−dP/dt), heart rate (HR), and coronary flow (CF) were measured at baseline, R30 min (30 min of reperfusion), R60 min, R90 min, and R120 min. Creatine kinase (CK) and lactate dehydrogenase (LDH) were measured after 5 min and 10 min reperfusion. Infarct size was determined by triphenyltetrazolium chloride staining at the end of reperfusion. Total Akt and phosphorylated Akt (phospho-Akt), Bax, Bcl-2, Bad, and phospho-Bad were determined by Western blot analysis. Analysis of variance (ANOVA) and Student-Newman-Keuls’ test were used to investigate the significance of differences between groups. The LVDP, ±dP/dt, and CF were higher and LVEDP was lower in the SPC group than in the Con group at all points of reperfusion (P<0.05). The SPC group had significantly reduced CK and LDH release and decreased infarct size compared with the Con group [(22.9±8)% vs. (42.4±9.4)%, respectively; P<0.05]. The SPC group also had increased the expression of phosphor-Akt, Bcl-2, and phospho-Bad, and decreased the expression of Bax. Wortmannin abolished the cardioprotection of sevoflurane postconditioning. Sevoflurane postconditioning may protect the isolated rat heart. Activation of PI3K and modulation of the expression of pro- and antiapoptotic proteins may play an important role in sevoflurane-induced myocardial protection.
PMCID: PMC2932876  PMID: 20803770
Sevoflurane; Postconditioning; Cardioprotection; Akt; Bcl-2; Bad
4.  Effects of sevoflurane preconditioning and postconditioning on rat myocardial stunning in ischemic reperfusion injury*  
Ischemic preconditioning and postconditioning distinctly attenuate ventricular arrhythmia after ischemia without affecting the severity of myocardial stunning. Therefore, we report the effects of sevoflurane preconditioning and postconditioning on stunned myocardium in isolated rat hearts. Isolated rat hearts were underwent 20 min of global ischemia and 40 min of reperfusion. After an equilibration period (20 min), the hearts in the preconditioning group were exposed to sevoflurane for 5 min and next washout for 5 min before ischemia. Hearts in the sevoflurane postconditioning group underwent equilibration and ischemia, followed immediately by sevoflurane exposure for the first 5 min of reperfusion. The control group received no treatment before and after ischemia. Left ventricular pressure, heart rate, coronary flow, electrocardiogram, and tissue histology were measured as variables of ventricular function and cellular injury, respectively. There was no significant difference in the duration of reperfusion ventricular arrhythmias between control and sevoflurane preconditioning group (P=0.195). The duration of reperfusion ventricular arrhythmias in the sevoflurane postconditioning group was significantly shorter than that in the other two groups (P<0.05). ±(dP/dt)max in the sevoflurane preconditioning group at 5, 10, 15, 20, and 30 min after reperfusion was significantly higher than that in the control group (P<0.05), and there were no significant differences at 40 min after reperfusion among the three groups (P>0.05). As expected, for a 20-min general ischemia, infarct size in heart slices determined by 2,3,5-triphenyltetrazolium chloride staining among the groups was not obvious. Sevoflurane postconditioning reduces reperfusion arrhythmias without affecting the severity of myocardial stunning. In contrast, sevoflurane preconditioning has no beneficial effects on reperfusion arrhythmias, but it is in favor of improving ventricular function and recovering myocardial stunning. Sevoflurane preconditioning and postconditioning may be useful for correcting the stunned myocardium.
PMCID: PMC2852543  PMID: 20349523
Inhalation anesthetics; Sevoflurane; Postconditioning; Preconditioning; Ischemia-reperfusion injury; Myocardial stunning
5.  A probiotic treatment containing Lactobacillus, Bifidobacterium and Enterococcus improves IBS symptoms in an open label trial 
Objective: To evaluate the efficacy and safety of live combined Bifidobacterium, Lactobacillus and Enterococcus capsules in treatment of irritable bowel syndrome. Methods: Eighty-five patients [male 32, female 53; age (45.31±11.72) years] were given live combined Bifidobacterium, Lactobacillus and Enterococcus capsules 1260 mg/d t.i.d.×4 weeks. Syndrome scales were used to evaluate the efficacy in gastrointestinal syndrome. Fecal flora was also measured before and after the treatment. Six bacteria were cultured and the colony forming units were counted in stool. SPSS was used for data analysis. Results: Seventy-four patients finished the follow-up. No side-effect was found. For treatment of irritable bowel syndrome, the effective rate of live combined Bifidobacterium, Lactobacillus and Enterococcus capsules was 56.8% in the second week, 74.3% in the fourth week and 73.0% in the sixth week. Single symptom was improved, especially in abdominal pain and stool character. The probiotica containing live combined Bifidobacterium, Lactobacillus and Enterococcus could increase bifidobacterium count (P<0.01) and lactobacillus count (P<0.05); decrease bacteroides count (P<0.05) and enterococci count (P<0.01); No obvious changes were observed in clostridium difficile colonitis and enterobacteriaceae (P>0.05). Conclusion: The result of the study indicated that the administration of live combined Bifidobacterium, Lactobacillus and Enterococcus improved the symptom of irritable bowel syndrome and that there was a gradual increase of this effect. Thereafter conditions remained stable for 2 weeks. That improvement may be associated with alterations in gastrointestinal flora.
PMCID: PMC1661666  PMID: 17111468
Irritable bowel syndrome (IBS); Intestinal flora; Probiotic agents
6.  Effects of three fluid resuscitation methods on apoptosis of visceral organs in rats with hemorrhagic shock 
Objective: To observe the effects of three fluid resuscitation methods on apoptosis of visceral organs in rats with hemorrhagic shock. Methods: A model of rat with severe hemorrhagic shock and active bleeding was established in 32 SD (Sprague-Dawley) rats. The rats were randomly divided into control group, no fluid resuscitation group (NF group), controlled fluid resuscitation group (NS40 group) and rapid large scale fluid resuscitation group (NS80 group). Each group contained 8 rats. The curative effects were compared. At the same time, the apoptosis in liver, kidney, lung and small intestinal mucosa of survivors after hemorrhage and resuscitation was detected by light microscopy in HE (hematoxylin and eosin) stained tissue sections, flow cytometry and terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL). Results: The survival rate of early fluid resuscitation (14/16) was markedly higher than that of NF group (3/8). There was some apoptosis in liver, kidney, lung and small intestinal mucosa of all survivors. Compared with NF and NS40 groups, the apoptosis of liver, kidney and small intestinal mucosa of NS80 group was obviously increased. Conclusions: Among three fluid resuscitation methods, controlled fluid resuscitation can obviously improve the early survival rate and the apoptosis of liver, kidney and small intestinal mucosa in rats with severe and uncontrolled hemorrhagic shock, and may benefit improvement of prognosis.
PMCID: PMC1389910  PMID: 16130194
Shock; Hemorrhagic; Resuscitation; Apoptosis
7.  Survival of the biocontrol agents Brevibacillus brevis ZJY-1 and Bacillus subtilis ZJY-116 on the spikes of barley in the field*  
Fusarium head blight (FHB) caused by Fusarium graminearum is a devastating disease that results in extensive yield losses to wheat and barley. A green fluorescent protein (GFP) expressing plasmid pRP22-GFP was constructed for monitoring the colonization of two biocontrol agents, Brevibacillus brevis ZJY-1 and Bacillus subtilis ZJY-116, on the spikes of barley and their effect on suppression of FHB. Survival and colonization of the Brevibacillus brevis ZJY-1 and Bacillus subtilis ZJY-116 strains on spikes of barley were observed by tracking the bacterial transformants with GFP expression. Our field study revealed that plasmid pRP22-GFP was stably maintained in the bacterial strains without selective pressure. The retrieved GFP-tagged strains showed that the bacterial population fluctuation accorded with that of the rain events. Furthermore, both biocontrol strains gave significant protection against FHB on spikes of barley in fields. The greater suppression of barley FHB disease was resulted from the treatment of barley spikes with biocontrol agents before inoculation with F. graminearum.
PMCID: PMC1389858  PMID: 16052710
GFP; Survival; Brevibacillus brevis and Bacillus subtilis; Spikes; Barley; Biocontrol

Results 1-7 (7)