富含蛋氨酸玉米醇溶蛋白在枯草芽胞杆菌中的表达

蛋氨酸是畜禽饲料中的第一限制性氨基酸,也是饲料产品进行质量控制与质量评价最为关注的指标之一。利用基因工程方法,从玉米胚乳中克隆高蛋氨酸蛋白基因（10kuδzein）,与pHT43构建重组表达质粒,将其转入枯草芽胞杆菌中,IPTG诱导其表达,发现重组菌在26ku处出现了1条明显条带。HPLC检测蛋氨酸含量,重组菌的蛋氨酸含量比野生型菌株提高了20．51％。该重组菌为以后将其做为饲料添加剂进一步应用提供了技术基础。     

雌激素、孕激素对雌激素受体、孕激素受体阴性子宫内膜腺癌细胞系JEC裸鼠皮下移植瘤生长的影响

目的探讨一定浓度雌激素(E2)及孕激素(P)对雌激素受体(ER)和孕激素受体(PR)阴性的子宫内膜腺癌细胞系JEC裸鼠移植瘤的影响。方法选用人子宫内膜腺癌细胞系JEC为研究对象,Balb/c.nu裸鼠皮下注射8×105个/0.2mLJEC细胞,分别注射E2、P及NS连续一周,观察肿瘤的生长及病理学变化情况。结果各组肿瘤体积、瘤体重量及瘤细胞核的积分光密度值依次为E2组>NS组>P组,差异有统计学意义(P<0.01)。结论 ER和PR阴性的JEC细胞生长可受到雌激素和孕激素的调控,一定浓度的雌激素能促进瘤体的生长,而孕激素则对瘤体的生长有抑制效应。     

链霉素对鸟听觉毒性作用的研究

目的：了解链霉素对鸟听觉毒性的作用。方法：选33只健康成年虎皮鹦鹉,不同剂量的链霉素肌肉注射15日,脑干听觉诱发电位测试外周的听觉敏度和听觉通路中神经的传导和传递能力。结果：链霉素对鸟听觉有毒性作用。结论：用链霉素处理鸟可以制作聋鸟模型。     

褐头鸫巢址选择和活动区的初步研究

褐头鸫是国际受胁物种,繁殖地仅分布在我国的华北山地,迄今有关该物种的生态研究尚无专门报道.我们于2005 年5 月至2006 年8 月对北京和河北两地褐头鸫的巢址选择和活动区进行了初步研究.调查共发现褐头鸫的巢7 个,其中北京百花山6 个,河北雾灵山1 个.巢址平均海拔1805 m±86 m(1730～1930 m),巢树均为华北落叶松 Larix principis-rupprechtii ,巢树高度11.3 m±2.2 m(8～14 m).巢距地的平均高度为5.3 m±1.5 m(4～7 m),巢址周围隐蔽性较好,天敌很难发现.2006年6～7月,利用无线电遥测技术在河北雾灵山国家级自然保护区对一只褐头鸫的雌鸟进行了无线电遥测,采用95%调和平均数法来计算,其繁殖期的活动区面积为1.93 hm2±0.76 hm2.     

石榴籽油的微波提取和体外抗氧化作用研究

比较常规回流提取与微波提取法对石榴籽油的提取率,并采用正交实验法优选微波提取最佳工艺条件。结果表明,出油率有显著性差异(P<0.01),微波提取出油率高,其提取最佳工艺条件为:物液比为1:5(g:mL),微波处理时间为50s×5(即每次处理50s,间歇处理5次),微波功率为480w。用Schaal烘箱法(60±1℃)比较了石榴籽油和维生素E抗猪油和色拉油氧化的作用,石榴籽油的体外抗氧化作用优于维生素E,具有很好的应用前景。     

Reduced Expression of the Polymeric Immunoglobulin Receptor in Pancreatic and Periampullary Adenocarcinoma Signifies Tumour Progression and Poor Prognosis

The polymeric immunoglobulin receptor (pIgR) is a key component of the mucosal immune system that mediates epithelial transcytosis of immunoglobulins. High pIgR expression has been reported to correlate with a less aggressive tumour phenotype and an improved prognosis in several human cancer types. Here, we examined the expression and prognostic significance of pIgR in pancreatic and periampullary adenocarcinoma. The study cohort encompasses a consecutive series of 175 patients surgically treated with pancreaticoduodenectomy for pancreatic and periampullary adenocarcinoma in Malmö and Lund University Hospitals, Sweden, between 2001–2011. Tissue microarrays were constructed from primary tumours (n = 175) and paired lymph node metastases (n = 105). A multiplied score was calculated from the fraction and intensity of pIgR staining. Classification and regression tree analysis was used to select the prognostic cut-off. Unadjusted and adjusted hazard ratios (HR) for death and recurrence within 5 years were calculated. pIgR expression could be evaluated in 172/175 (98.3%) primary tumours and in 96/105 (91.4%) lymph node metastases. pIgR expression was significantly down-regulated in lymph node metastases as compared with primary tumours (p = 0.018). Low pIgR expression was significantly associated with poor differentiation grade (p<0.001), perineural growth (p = 0.027), lymphatic invasion (p = 0.016), vascular invasion (p = 0.033) and infiltration of the peripancreatic fat (p = 0.039). In the entire cohort, low pIgR expression was significantly associated with an impaired 5-year survival (HR = 2.99, 95% confidence interval (CI) 1.71–5.25) and early recurrence (HR = 2.89, 95% CI 1.67–4.98). This association remained significant for survival after adjustment for conventional clinicopathological factors, tumour origin and adjuvant treatment (HR = 1.98, 95% CI 1.10–3.57). These results demonstrate, for the first time, that high tumour-specific pIgR expression signifies a more favourable tumour phenotype and that low expression independently predicts a shorter survival in patients with pancreatic and periampullary cancer. The mechanistic basis for the putative tumour suppressing properties of pIgR in these cancers merits further study.     

《中药鉴定学》综合性、设计性实验教学改革初探

阐述与分析了《中药鉴定学》综合性、设计性实验内容及实践模式,表明本学科综合性、设计性实验对培养学生实践技能、创新精神和素质教育的作用和意义。     

Carnosol Induces ROS-Mediated Beclin1-Independent Autophagy and Apoptosis in Triple Negative Breast Cancer

Background

In this study we investigated the in vitro and in vivo anticancer effect of carnosol, a naturally occurring polyphenol, in triple negative breast cancer.

Results

We found that carnosol significantly inhibited the viability and colony growth induced G2 arrest in the triple negative MDA-MB-231. Blockade of the cell cycle was associated with increased p21/WAF1 expression and downregulation of p27. Interestingly, carnosol was found to induce beclin1-independent autophagy and apoptosis in MDA-MB-231 cells. The coexistence of both events, autophagy and apoptosis, was confirmed by electron micrography. Induction of autophagy was found to be an early event, detected within 3 h post-treatment, which subsequently led to apoptosis. Carnosol treatment also caused a dose-dependent increase in the levels of phosphorylated extracellular signal-regulated kinase 1 and 2 (pERK1/2). Moreover, we show that carnosol induced DNA damage, reduced the mitochondrial potential and triggered the activation of the intrinsic and extrinsic apoptotic pathway. Furthermore, we found that carnosol induced a dose-dependent generation of reactive oxygen species (ROS) and inhibition of ROS by tiron, a ROS scavenger, blocked the induction of autophagy and apoptosis and attenuated DNA damage. To our knowledge, this is the first report to identify the induction of autophagy by carnosol.

Conclusion

In conclusion our findings provide strong evidence that carnosol may be an alternative therapeutic candidate against the aggressive form of breast cancer and hence deserves more exploration.     

玉米花粉特异的非编码RNA基因ZM401 cDNA全长的克隆及其发育表达模式

通过差异筛选法并结合冷噬菌斑筛选,从玉米(Zea mays L.)成熟花粉cDNA文库中克隆到一个玉米花粉特异表达的cDNA片段ZM401(663bp).Northern杂交表明ZM401是一个玉米花粉特异表达的基因.本文采用5'RACE,3'RACE及重叠PCR技术获得了ZM401 cDNA的全长(1 149 bp).采用生物学软件对ZM401 cDNA的序列和结构进行分析,结果表明,该基因缺乏明显的开放阅读框架,序列中最长的开放阅读框架仅有89个氨基酸,但具有poly(A)尾部结构,符合非编码RNA基因的特点.推断ZM401基因是一个非编码基因.RT-PCR及Northern blot分析表明ZM401基因从玉米花粉小孢子四分体时期、单核期、双核期、成熟花粉开始表达,而且表达量依次增强,证明ZM401可能与玉米花粉的晚期发育过程相关.同时,Northern杂交显示ZM401基因在玉米花粉发育中有两种转录本存在.