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Soluble sugars, including glucose, fructose and sucrose, are the most important determinants that affect the flavor and quality of red pitaya (Hylocereus polyrhizus) fruit. Vacuolar invertase (VIN), which catalyzes sucrose hydrolysis into glucose and fructose, is a key type of enzyme responsible for soluble sugar metabolism in plant growth and development. Herein, we conducted genome-wide identification, gene expression analysis, subcellular localization and an enzymatic properties assay for the VIN-encoding genes from red pitaya. During red pitaya fruit development towards ripening, the enzymatic activities of VIN showed an up-regulated trend towards ripening. In total, four isoforms (HpVIN1–4) of the VIN-encoding gene were identified from the pitaya genome. Sequence alignment results revealed that the HpVIN1, HpVIN3 and HpVIN4 proteins contained essential motifs for targeting the vacuole and conserved motifs or residues responsible for sucrose binding and hydrolysis. Gene expression pattern analyses revealed that the level of HpVIN4 was obviously increasing during fruit development and acted as the most abundant VIN isoform towards ripening. Subcellular localization detection via transient expression in Arabidopsis thaliana mesophyll protoplasts revealed that the HpVIN4 protein was localized in the vacuole. Growth complementation tests of heterologous expression in the invertase-deficient baker's yeast strain suggested that the HpVIN4 protein had a sucrose hydrolysis activity and could restore the yeast growth in vivo. The identification of enzymatic properties in vitro demonstrated that the HpVIN4 protein could degrade sucrose into glucose and fructose with an optimum pH of 4.0. Specifically, the HpVIN4 protein had an estimated Km value of 5.15 ± 1.03 mmol·L−1 for sucrose hydrolysis. Ultimately, this study provides a comprehensive understanding of the potential roles of VINs during fruit development and towards ripening and provides functional gene resources for regulating soluble sugar accumulation in red pitaya fruit. [ABSTRACT FROM AUTHOR]

Aim: To evaluate the application of bipolar coagulation (BIP) in hepatectomy by comparing the efficacy of BIP alone, cavitron ultrasonic surgical aspirator (CUSA) + BIP and conventional clamp crushing (CLAMP)., Methods: Based on our database of patient records, a total of 380 consecutive patients who underwent hepatectomy at our hospital were retrospectively studied for the efficacy of BIP alone, CUSA + BIP and CLAMP. Of all the patients, 75 received saline-coupled BIP (Group A), 53 received CUSA + BIP (Group B), and 252 received CLAMP (Group C). The pre-, mid-, and postoperative clinical manifestations were compared, and the effects of those maneuvers were evaluated., Results: There was no obvious difference among the preoperative indexes between the different groups. The operative time was longer in Groups A and B than in Group C (P < 0.001 for both). The amount of bleeding and the rate of transfusion during the operation were significantly higher in Group C than in Groups A and B (P < 0.001 for all). The incidence of postoperative complications in Group C (46.43%) was higher than that in Groups A (30.67%, P = 0.015) and B (28.30%, P = 0.016). The patients' liver function recovery and postoperative hospital stay were not significantly different. BIP could decrease intraoperative hemorrhage and postoperative complications compared to CLAMP., Conclusion: Simple saline-coupled BIP should be considered a safe and reliable technique for liver resection to decrease intraoperative hemorrhage and postoperative complications.

Objective: To study the inhibitory effect of T-2 toxin on the expression of aggrecan and collagen II in chondrocytes and the protection of selenium against this effect., Methods: Human chondrocytes cultured in vitro were treated with T-2 toxin at different concentrations for varied time periods (1-5 days), and the cell viability was measured by MTT assay. Aggrecan expression was detected by toluidine blue staining and collagen II expression by immunostaining using monoclonal antibody of collagen. Aggrecan and collagen II mRNA expressions were measured by semiquantitative RT-PCR., Results: T-2 toxin dose- and time-dependently affected chondrocyte viability within the concentration range of 0.001-2 mg/L, the prolonged treatment time further enhanced the dose dependence of the inhibitory effect. T-2 toxin lowered aggrecan and collagen II synthesis in the chondrocytes and reduced their mRNA expressions. Selenium could partly attenuate the inhibitory effects of T-2 toxin on aggrecan mRNA expression, but showed no such effect against T-2-induced collagen II expression., Conclusion: T-2 toxin can obviously inhibit aggrecan and collagen II synthesis in human chondrocytes, and selenium can partly antagonize the inhibitory effects of T-2 toxin on aggrecan.