The temporal and spatial Norrin expression and significance in oxygen induced retinopathy

AIM: To detect the expression and location of Norrin in mouse retina with oxygen-induced retinopathy (OIR). METHODS: Retinal neovascular angiogenesis of OIR mouse was observed by FITC-Dextran filled retinamounts. Norrin, VEGF mRNA expression was studied by RT-PCR in control mouse retina on postnatal days 7, 10, 12, 17 and in OIR mouse retina on postnatal days 7, 8, 12, 12.5, 13, 14, 15, 17 and 19. Norrin protein expression and location was observed by immunohistochemical methods. RESULTS: Retinal neovasculature was observed in OIR ischemic mouse on postnatal days 17. Norrin mRNA expression markedly increased in retina after hypoxia 12 hours, which was correlated with the upregulation of VEGF. The peak of increase in Norrin occurred at 24 hours, and levels then decreased slowly. Norrin was expressed in outer layers of retina of P15-17 OIR mice, and was not found in normal control mice retina. CONCLUSION: Increased levels of Norrin in OIR ischemic retina show temporal correlation with increased expression of VEGF. Increased Norrin locates in outer layers of retina. Norrin may play an important role in neovascular angiogenesis.     

不同因素对贺兰山丁香愈伤组织诱导的影响

利用正交实验设计研究4种因素(6-BA、NAA、2,4-D、外植体)对贺兰山丁香愈伤组织诱导的影响,筛选出最佳的愈伤组织诱导条件为MS 6-BA 0.5 mg/L 2,4-D 0.1 mg/L,其中6-BA的浓度和外植体类型对贺兰山丁香种苗的出愈率有极显著影响(P=0.01).同时发现子叶和胚轴均可作为外植体材料,且以胚轴为外植体在最佳诱导条件下出愈率高达93.3%.     

Blood eosinophil count and risk of postoperative pneumonia following coronary artery bypass graft surgery

AIM:To investigate the relationship between blood eosinophil count and risk of postoperative pneumonia in patients with coronary artery bypass graft (CABG) surgery. METHODS: The medical records of 613 patients who underwent CABG surgery from January 2008 to December 2017 in our hospital were collected and reviewed. The incidence of postoperative pneumonia and hospital mortality were compared in the patients with low or high blood eosinophil count. The risk factors for postoperative pneumonia following CABG surgery were analyzed by multiple logistic regression. RESULTS: The patients enrolled in the study were 582, in which 220 patients had preoperative blood eosinophil counts of less than 2% (low blood eosinophil count) and 362 patients had eosinophil counts of 2% or more (high blood eosinophil count). The incidence of postoperative pneumonia in the patients with low blood eosinophil count was 14.1% (31/220), significantly higher than that (6.4%, 23/362) in the patients with high blood eosinophil count (P=0.002). However, the hospital mortality of the patients with high or low blood eosinophil count had no difference. Low blood eosinophil count (OR=3.521, 95% CI:1.213~10.223, P=0.021), nasogastric tube (OR=6.490, 95% CI:2.757~15.280, P<0.001) and mechanical ventilation ≥ 24 h (OR=3.496, 95% CI:1.156~10.178, P=0.035) were identified as independent risk factors for postoperative pneumonia following CABG surgery. CONCLUSION: Low blood eosinophil count is associated with increased risk of postoperative pneumonia following CABG surgery.     

Attribution of human infections with Shiga toxin‐producing Escherichia coli (STEC) to livestock sources and identification of source‐specific risk factors,The Netherlands (2010–2014)

Shiga toxin‐producing Escherichia coli (STEC) is a zoonotic pathogen of public health concern whose sources and transmission routes are difficult to trace. Using a combined source attribution and case–control analysis, we determined the relative contributions of four putative livestock sources (cattle, small ruminants, pigs, poultry) to human STEC infections and their associated dietary, animal contact, temporal and socio‐econo‐demographic risk factors in the Netherlands in 2010/2011–2014. Dutch source data were supplemented with those from other European countries with similar STEC epidemiology. Human STEC infections were attributed to sources using both the modified Dutch model (mDM) and the modified Hald model (mHM) supplied with the same O‐serotyping data. Cattle accounted for 48.6% (mDM) and 53.1% (mHM) of the 1,183 human cases attributed, followed by small ruminants (mDM: 23.5%; mHM: 25.4%), pigs (mDM: 12.5%; mHM: 5.7%) and poultry (mDM: 2.7%; mHM: 3.1%), whereas the sources of the remaining 12.8% of cases could not be attributed. Of the top five O‐serotypes infecting humans, O157, O26, O91 and O103 were mainly attributed to cattle (61%–75%) and O146 to small ruminants (71%–77%). Significant risk factors for human STEC infection as a whole were the consumption of beef, raw/undercooked meat or cured meat/cold cuts. For cattle‐attributed STEC infections, specific risk factors were consuming raw meat spreads and beef. Consuming raw/undercooked or minced meat were risk factors for STEC infections attributed to small ruminants. For STEC infections attributed to pigs, only consuming raw/undercooked meat was significant. Consuming minced meat, raw/undercooked meat or cured meat/cold cuts were associated with poultry‐attributed STEC infections. Consuming raw vegetables was protective for all STEC infections. We concluded that domestic ruminants account for approximately three‐quarters of reported human STEC infections, whereas pigs and poultry play a minor role and that risk factors for human STEC infection vary according to the attributed source.     

毛鸡骨草GAP基地土壤肥力综合评价与供肥能力研究

[目的]了解毛鸡骨草GAP基地土壤肥力现状,以及土壤中氮、磷、钾3要素的自然供给能力。[方法]运用改进的内梅罗(Nemoro)综合指数法对基地土壤肥力进行综合评价,并通过施肥试验研究了基地土壤中氮、磷、钾3要素的自然供给能力。[结果]土壤综合肥力系数为1.21,毛鸡骨草产量对土壤的依存率为40.90%。[结论]基地土壤综合肥力属"一般"等级,土壤供应氮、磷、钾的能力分别处于"低"、"高"、"中"等级,较低的土壤含氮量是该基地的主要养分限制因子。     

表皮生长因子对葡聚糖硫酸钠诱导的结肠炎模型小鼠肠道损伤的修复研究

本文旨在讨论表皮生长因子(EGF)对葡聚糖硫酸钠(DSS)诱导的结肠炎模型小鼠肠道损伤的修复作用。选用24只6周龄BALB/c小鼠,随机分为3组,即:正常对照组、DSS模型对照组、DSS+EGF组。正常对照组小鼠饮用自来水;DSS模型对照组小鼠在试验第1~7天饮用5%DSS水溶液,第8~10天饮用自来水;DSS+EGF组小鼠按照DSS模型对照组处理,同时每天皮下注射EGF 2次,共注射10 d。结果表明:1)与正常对照组相比,DSS模型对照组小鼠结肠长度极显著降低(P0.01);与DSS模型对照组相比,DSS+EGF组小鼠结肠长度极显著增加(P0.01)。2)DSS模型对照组小鼠结肠可见典型溃疡,结肠损伤程度评分(CDS)极显著高于正常对照组(P0.01);DSS+EGF组小鼠结肠组织未见溃疡,与DSS模型对照组相比,CDS极显著降低(P0.01)。3)与正常对照组相比,DSS模型对照组小鼠结肠紧密连接蛋白(Occludin)浓度显著降低(P0.05);与DSS模型对照组相比,DSS+EGF组小鼠结肠Occludin浓度显著升高(P0.05)。4)与正常对照组相比,DSS模型对照组小鼠结肠白细胞介素-2(IL-2)和白细胞介素-4(IL-4)浓度极显著降低(P0.01),白细胞介素-10(IL-10)浓度显著降低(P0.05);与DSS模型对照组相比,DSS+EGF组结肠IL-2和IL-4浓度极显著增加(P0.01),IL-10浓度显著增加(P0.05)。由此可见,EGF可能通过提高肠道Occludin表达水平,调节肠道细胞因子浓度趋于正常水平,从而修复受损肠道组织,维持肠道黏膜屏障的完整性。     

抗菌肽抑制脂多糖诱导的炎症反应

抗菌肽是一种对多重耐药菌株表现出特异性抗菌机制的小分子多肽。同时,抗菌肽还具有抗炎活性,可以通过直接中和脂多糖(LPS)、抑制生物性炎症因子的产生来减轻炎症反应;亦可通过趋化白细胞、促进免疫细胞增殖等来影响获得性免疫,从而调节宿主免疫系统发挥保护作用。本文综述了近年来LPS诱导炎症产生的机制及抗菌肽抑制LPS诱导炎症反应的作用机理。