13 research outputs found

    Transcriptional regulation of a pineapple polyphenol oxidase gene and its relationship to blackheart

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    Two genes encoding polyphenol oxidase (PPO) were isolated from pineapple (Ananas comosus[L.] Merr. cv. Smooth Cayenne). Sequence analyses showed that both contained a single intron and encoded typical chloroplast-localized PPO proteins, the sequences of which corresponded to two pineapple PPO cDNAs, PINPPO1 and PINPPO2, recently described by Stewart et al. (2001). Southern blot analyses suggested that pineapple contained only two PPO genes. Analysis of expression of PINPPO1 promoter GUS fusion constructs showed this promoter had a low basal activity and was cold- and wound-inducible, consistent with known mRNA expression profiles. Striking homologies to gibberellin response complexes (GARC) were observed in sequences of both the PINPPO1 and PINPPO2 promoters. Transient assays in mature pineapple fruit and stable expression in transgenic tobacco showed that PINPPO1 promoter-GUS fusions were indeed gibberellin (GA) responsive. A role for the element within the putative GARCs in mediating GA-responsiveness of the PINPPO1 promoter was confirmed by mutational analysis. PINPPO2 was also shown to be GA-responsive by RT-PCR analysis. Mutant PINPPO1 promoter–GUS fusion constructs, which were no longer GA-inducible, showed a delayed response to cold induction in pineapple fruit in transient assays, suggesting a role for GA in blackheart development. This was supported by observations that exogenous GA₃ treatment induced blackheart in the absence of chilling. Sequences showing homology to GARCs are also present in some PPO promoters in tomato, suggesting that GA regulates PPO expression in diverse species

    Use of failure-to-rescue to identify international variation in postoperative care in low-, middle- and high-income countries:a 7-day cohort study of elective surgery

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    Background. The incidence and impact of postoperative complications are poorly described. Failure-to-rescue, the rate of death following complications, is an important quality measure for perioperative care but has not been investigated across multiple health care systems. Methods. We analysed data collected during the International Surgical Outcomes Study, an international 7-day cohort study of adults undergoing elective inpatient surgery. Hospitals were ranked by quintiles according to surgical procedural volume (Q1 lowest to Q5 highest). For each quintile we assessed in-hospital complications rates, mortality, and failure-to-rescue. We repeated this analysis ranking hospitals by risk-adjusted complication rates (Q1 lowest to Q5 highest). Results. A total of 44 814 patients from 474 hospitals in 27 low-, middle-, and high-income countries were available for analysis. Of these, 7508 (17%) developed one or more postoperative complication, with 207 deaths in hospital (0.5%), giving an overall failure-to-rescue rate of 2.8%. When hospitals were ranked in quintiles by procedural volume, we identified a threefold variation in mortality (Q1: 0.6% vs Q5: 0.2%) and a two-fold variation in failure-to-rescue (Q1: 3.6% vs Q5: 1.7%). Ranking hospitals in quintiles by risk-adjusted complication rate further confirmed the presence of important variations in failureto- rescue, indicating differences between hospitals in the risk of death among patients after they develop complications. Conclusions. Comparison of failure-to-rescue rates across health care systems suggests the presence of preventable postoperative deaths. Using such metrics, developing nations could benefit from a data-driven approach to quality improvement, which has proved effective in high-income countries

    Cougar figures, gender, and the performances of predation

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    Introduction to Marine Biotechnology

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    Embryonic angiogenesis: A review

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