214 research outputs found

    Invasive Respiratory or Vasopressor Support and/or Death as a Proposed Composite Outcome Measure for Perioperative Care Research

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    BACKGROUND: There is a need for a clinically relevant and feasible outcome measure to facilitate clinical studies in perioperative care medicine. This large-scale retrospective cohort study proposed a novel composite outcome measure comprising invasive respiratory or vasopressor support (IRVS) and death. We described the prevalence of IRVS in patients undergoing major abdominal surgery and assessed the validity of combining IRVS and death to form a composite outcome measure. METHODS: We retrospectively collected perioperative data for 2776 patients undergoing major abdominal surgery (liver, colorectal, gastric, pancreatic, or esophageal resection) at Kyoto University Hospital. We defined IRVS as requirement for mechanical ventilation for ≥24 hours postoperatively, postoperative reintubation, or postoperative vasopressor administration. We evaluated the prevalence of IRVS within 30 postoperative days and examined the association between IRVS and subsequent clinical outcomes. The primary outcome of interest was long-term survival. Multivariable Cox proportional regression analysis was performed to adjust for the baseline patient and operative characteristics. The secondary outcomes were length of hospital stay and hospital mortality. RESULTS: In total, 85 patients (3.1%) received IRVS within 30 postoperative days, 15 of whom died by day 30. Patients with IRVS had a lower long-term survival rate (1- and 3-year survival probabilities, 66.1% and 48.5% vs 95.2% and 84.0%, respectively; P < .001, log-rank test) compared to those without IRVS. IRVS was significantly associated with lower long-term survival after adjustment for the baseline patient and operative characteristics (adjusted hazard ratio, 2.72; 95% confidence interval, 1.97–3.77; P < .001). IRVS was associated with a longer hospital stay (median [interquartile range], 65 [39–326] vs 15 [12–24] days; adjusted P < .001) and a higher hospital mortality (24.7% vs 0.5%; adjusted P < .001). Moreover, IRVS was adversely associated with subsequent clinical outcomes including lower long-term survival (adjusted hazard ratio, 1.78; 95% confidence interval, 1.21–2.63; P = .004) when the analyses were restricted to 30-day survivors. CONCLUSIONS: Patients with IRVS can experience ongoing risk of serious morbidity and less long-term survival even if alive at postoperative day 30. Our findings support the validity of using IRVS and/or death as a composite outcome measure for clinical studies in perioperative care medicine

    Characterization of a sperm factor for egg activation at fertilization of the newt Cynops pyrrhogaster

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    AbstractEggs of the newt, Cynops pyrrhogaster, arrested at the second meiotic metaphase are activated by sperm at fertilization and then complete meiosis to initiate development. We highly purified a sperm factor for egg activation from a sperm extract with several chromatographies. The purified fraction containing only a 45 kDa protein induced egg activation accompanied by an intracellular Ca2+ increase when injected into unfertilized eggs. Although injection of mouse phospholipase C (PLC) ζ-mRNA caused a Ca2+ increase and egg activation, partial amino acid sequences of the 45 kDa protein were homologous to those of Xenopus citrate synthase, but not to PLCs. An anti-porcine citrate synthase antibody recognized the 45 kDa protein both in the purified fraction and in the sperm extract. Treatment with the anti-citrate synthase antibody reduced the egg-activation activity in the sperm extract. Injection of porcine citrate synthase or mRNA of Xenopus citrate synthase induced a Ca2+ increase and caused egg activation. A large amount of the 45 kDa protein was localized in two lines elongated from the neck to the middle piece of sperm. These results indicate that the 45 kDa protein is a major component of the sperm factor for egg activation at newt fertilization

    Luteinising hormone-releasing hormone analogue reverses the cell adhesion profile of EGFR overexpressing DU-145 human prostate carcinoma subline

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    Cetrorelix, a luteinising hormone-releasing hormone (LHRH) analogue, has been shown to limit growth of the human androgen-independent prostate cell line DU-145, although other inhibitory actions may also be affected. Both growth and invasion of DU-145 cells are linked to autocrine epidermal growth factor receptor (EGFR) signalling. Invasiveness requires not only cells to migrate to conduits, but also reduced adhesiveness between tumour cells to enable separation from the tumour mass. Thus, we investigated whether Cetrorelix alters the DU-145 cell–cell adhesion and if this occurs via altered EGFR signalling. Pharmacologic levels of Cetrorelix limited the invasiveness of a highly invasive DU-145 subline overexpressing full-length EGFR (DU-145 WT). Extended exposure of the cells to Cetrorelix resulted in increased levels of the cell–cell adhesion complex molecules E-cadherin, α- and β-catenin, and p120. Puromycin blocked the increases in E-cadherin and β-catenin levels, suggesting that de novo protein synthesis is required. The Cetrorelix effect appears to occur via transmodulation of EGFR by a protein kinase C (PKC)-dependent mechanism, as there were no changes in DU-145 cells expressing EGFR engineered to negate the PKC transattenuation site (DU-145 A654); downregulation of EGFR signalling produced a similar upregulation in adhesion complex proteins, further suggesting a role for autocrine signalling. Cetrorelix increased the cell–cell adhesiveness of DU-145 WT cells to an extent similar to that seen when autocrine EGFR signalling is blocked; as expected, DU-145 A654 cell–cell adhesion also was unaffected by Cetrorelix. The increased adhesiveness is expected as the adhesion complex molecules moved to the cells' periphery. These data offer direct insight into the possible crosstalk pathways between the LHRH and EGFR receptor signalling. The ability of Cetrorelix to downregulate EGFR signalling and subsequently reverse the antiadhesiveness found in metastatic prostate cancer highlights a novel potential target for therapeutic strategies

    Application of droplet-PIXE system to study radiation effects on ecosystem functioning

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    Droplet PIXE analysis was applied to the study of radiation effects on soil ecosystem functioning. A paddy soil sample was flooded with well water to prepare soil ecosystem specimens (microcosms), and then the microcosms were chronically exposed to gamma rays at a dose rate of 1 Gy day-1 for 5 days. After the final irradiation, a brownish discoloration was observed in the liquid phases of the irradiated microcosms. To clarify the factors causing the discoloration, minerals in the solutions of the microcosms were analyzed by the droplet PIXE system. Elemental profiles from the XRF spectrum showed marked iron peaks. Exposure of microcosms to gamma rays resulted in a decrease in the iron levels. Since iron is released in the form of Fe(II) from the solid soil to the liquid phase, further determination of the Fe(II) levels was performed. The percentages of Fe(II) to the total iron in the liquid phase of the irradiated microcosms were lower than those of the controls. This result may be caused by the change of Fe species from soluble Fe(II) to insoluble Fe(III) during gamma irradiation, and the Fe(III) species with a brownish color may be associated with the discoloration of the irradiated samples. The conversion from soluble to insoluble forms may also contribute the small amount of dissolved iron in the irradiated microcosms. Iron is an essential trace nutrient for plants, and thus the amount of dissolved iron is one aspect of ecosystem functioning. Effects of gamma radiation on the dissolved iron could involve a change in the soil ecosystem through the depression of iron flux in the long term
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