萎缩芽胞杆菌CKL1促盐胁迫下燕麦生长活性及其功能基因分析

【背景】青海省特殊生境孕育了特殊微生物资源。【目的】探究适合生活于高原生境的芽胞杆菌菌源。【方法】采用平板对峙法、显色法对萎缩芽胞杆菌（Bacillus atrophaeus） CKL1的拮抗、产吲哚乙酸活性进行测定,并检测耐低温、耐盐性及菌株对盐胁迫下燕麦品种（Avena sativa）“青燕1号”种子萌发、幼苗生长效应及叶绿素、脯氨酸、丙二醛的含量变化,利用二代测序技术对菌株进行基因组测序并分析相关功能基因。【结果】菌株CKL1对禾谷镰孢菌（Fusarium graminearum）、锐顶镰孢菌（Fusarium acuminatum）表现出显著的拮抗活性（抑菌圈直径>15 mm）;与Salkowski比色液反应变红,能在NaCl浓度为13%的LB培养基及4℃低温下生长,表现出一定的产吲哚乙酸、耐盐及耐低温活性;盐胁迫下,菌株CKL1对“青燕1号”种子萌发及幼苗生长具有显著促进作用,叶绿素及脯氨酸含量显著增加,丙二醛含量下降,增强了燕麦的抗盐性。菌株CKL1基因组全长为14 281 280 bp,与GO功能数据库比对注释到3 303个功能基因;基因组编码与脂肽类化合物itur...     

Activated protein C--an anticoagulant that does more than stop clots

Activated protein C (APC) is a glycoprotein derived from its precursor, protein C and formed by the cleavage of an activation peptide by thrombin bound to thrombomodulin. Originally thought to be synthesized exclusively by the liver, recent reports have shown that protein C is synthesized by endothelial cells, keratinocytes and some hematopoietic cells.APC functions as a physiological anticoagulant with cytoprotective, anti-inflammatory and anti-apoptotic properties. In vitro and preclinical data have revealed that APC exerts its protective effects via an intriguing mechanism requiring endothelial protein C receptor and the thrombin receptor, protease-activated receptor-1. Remarkably, even though APC cleaves this receptor in an identical fashion to thrombin, it exerts opposing effects.Recently approved as a therapeutic agent for severe sepsis, APC is now emerging as a potential treatment for a number of autoimmune and inflammatory diseases including lung disorders, spinal cord injury and chronic wounds. The future pharmacologic use of APC holds remarkable promise.     

Rad9 plays an important role in DNA mismatch repair through physical interaction with MLH1

Rad9 is conserved from yeast to humans and plays roles in DNA repair (homologous recombination repair, and base-pair excision repair) and cell cycle checkpoint controls. It has not previously been reported whether Rad9 is involved in DNA mismatch repair (MMR). In this study, we have demonstrated that both human and mouse Rad9 interacts physically with the MMR protein MLH1. Disruption of the interaction by a single-point mutation in Rad9 leads to significantly reduced MMR activity. This disruption does not affect S/M checkpoint control and the first round of G₂/M checkpoint control, nor does it alter cell sensitivity to UV light, gamma rays or hydroxyurea. Our data indicate that Rad9 is an important factor in MMR and carries out its MMR function specifically through interaction with MLH1.     

沙冬青子叶原生质体瞬时表达体系的建立及其AmDREB1蛋白的亚细胞定位

以沙冬青(Ammopiptanthus mongolicus(Maxim.ex Kom.)Cheng f.)幼苗的子叶为材料,对其原生质体的分离、纯化和瞬时表达体系进行了研究。结果表明,子叶原生质体分离的最佳酶解液组成为CPW溶液+3.0%纤维素酶R-10+0.5%离析酶R-10+0.3%半纤维素酶+9.0%甘露醇(p H5.8);最佳酶解条件为室温、避光、40 r/min轻摇14 h。采用W5溶液作为漂洗液将酶解物稀释后进行过滤,将过滤液在4℃、700 r/min条件下离心5 min,所得纯化原生质体的产量约为2.50×106cells/g,活力达到90%;以纯化的原生质体作为受体,利用聚乙二醇(PEG)介导法成功将植物瞬时表达载体p BI-GFP导入其中,转化效率达到50.8%。利用本研究建立的原生质体瞬时表达体系,检测到沙冬青脱水应答转录因子Am DREB1定位于细胞核内。     

Survival Impact of Delaying Postoperative Radiotherapy in Patients with Esophageal Cancer

The purpose of the current study was to retrospectively assess the effect of postoperative radiotherapy (RT) delay on survival for patients with esophageal cancer. From 2008 to 2011, patients with esophageal cancer who had undergone postoperative RT in five different hospitals in China were reviewed. Clinical data, including time interval between surgery to RT, were prospectively collected. Kaplan-Meier method was conducted to estimate the effect of each variable on progression-free survival (PFS) and overall survival (OS), with differences assessed by log-rank test. Univariate Cox proportional-hazards models were performed for both PFS and OS for all assumed predictor variables. Statistically significant predictor variables (P < .05) on univariate analysis were then included in multivariate Cox proportional-hazards models, which were performed to compare the effects of RT delay on PFS and OS. A total of 316 patients were finally enrolled in this prospectively multicentric study. Time to RT after surgery varied from 12 days to over 60 days (median, 26 days). Multivariate analysis showed that delay to RT longer than the median does not appear to be a survival cost. There was also no statistically difference in PFS (P = .513) or OS (P = .236) between patients stratified by quartiles (≤21 days vs ≧35 days). However, patients with particularly long delays (≧42 days) demonstrated a detrimental impact on OS (P = .021) but not PFS (P = .580). Delaying postoperative RT of esophageal cancer does not impact PFS, but results in a significant reduction on OS if delaying longer than 6 weeks.