The mouse Wnt-1 gene can act via a paracrine mechanism in transformation of mammary epithelial cells.

The mouse Wnt-1 gene plays an essential role in fetal brain development and can contribute to tumorigenesis when activated aberrantly in the mammary gland. The gene encodes secretory glycoproteins associated with the extracellular or pericellular matrix, and it has been proposed that Wnt-1, as well as its Drosophila homolog wingless, may function in intercellular signalling. We show here that fibroblasts expressing Wnt-1 protein, although not transformed themselves, are able to elicit morphological transformation of neighboring C57MG mammary epithelial cells in coculture experiments. Heparin inhibits this effect, possibly by displacing Wnt-1 protein from its normal site of action. Our results indicate that the Wnt-1 gene can act via a paracrine mechanism in cell culture and strongly support the notion that in vivo the gene may function in cell-to-cell communication.     

Regulation of emotional memory by hydrogen sulfide: role of GluN2B‐containing NMDA receptor in the amygdala

As an endogenous gaseous molecule, hydrogen sulfide (H₂S) has attracted extensive attention because of its multiple biological effects. However, the effect of H₂S on amygdala‐mediated emotional memory has not been elucidated. Here, by employing Pavlovian fear conditioning, an animal model widely used to explore the neural substrates of emotion, we determined whether H₂S could regulate emotional memory. It was shown that the H₂S levels in the amygdala of rats were significantly elevated after cued fear conditioning. Both intraamygdala and systemic administrations of H₂S markedly enhanced amygdala‐dependent cued fear memory in rats. Moreover, it was found that H₂S selectively increased the surface expression and currents of NMDA‐type glutamate receptor subunit 2B (GluN2B)‐containing NMDA receptors (NMDARs) in lateral amygdala of rats, whereas blockade of GluN2B‐containing NMDARs in lateral amygdala eliminated the effects of H₂S to enhance amygdalar long‐term potentiation and cued fear memory. These results demonstrate that H₂S can regulate amygdala‐dependent emotional memory by promoting the function of GluN2B‐containing NMDARs in amygdala, suggesting that H₂S‐associated signaling may hold potential as a new target for the treatment of emotional disorders.

     

凝血酶1和转化生长因子β在糖尿病大鼠心肌细胞高表达的研究(简报)

糖尿病心肌病是极度危险的糖尿病并发症之一.它的发病机制目前尚未明确.本研究采用30只Sprague-Dawley大鼠随机分为2组:糖尿病大鼠组(15只),尾静脉注射链脲佐茵素造模,正常组大鼠(15只),尾静脉注射生理盐水,成模4周后采用苏木精-伊红染色及透射电子显微镜观察两组大鼠心肌细胞纤维显微结构和超微结构的病理改变,同时免疫组织化学SABC法对糖尿病大鼠与正常大鼠心肌细胞中凝血酶1(TSP-1)和转化生长因子β(TGF-β)的表达进行观察.糖尿病大鼠成模前,两组动物的体重、血糖和尿糖检测结果间无显著差异(P>0.05).成模四周后,糖尿病大鼠与正常大鼠体重、血糖和尿糖检测结果有显著性差异(P<0.01).光镜和电子显微镜观察显示糖尿病大鼠心肌组织结构有明显改变.糖尿病大鼠心肌细胞内TSP-1和TGF-β的表达显著增强(P<0.01).本研究结果表明TSP-1和TGF-β在糖尿痛大鼠的表达增加可能是糖尿病心肌病发病的一个重要因素.     

两种树脂基托细菌粘附情况的比较

目的比较BPS注塑树脂和热凝基托树脂表面细菌粘附能力的大小。方法将BPS注塑树脂和热凝基托树脂试件进行细菌体外粘附实验,采用菌落形成单位计数法测定血型链球菌、粘性放线菌和白色念珠菌粘附量的大小。结果培养24h、48h、168h后,各BPS注塑树脂试件组的细菌粘附量均少于热凝基托树脂试件组。结论BPS注塑树脂较热凝基托树脂更能减少血型链球菌、粘性放线菌和白色念珠菌在其表面的粘附。     

High‐yield recombinant expression of the chicken antimicrobial peptide fowlicidin‐2 in Escherichia coli

The antimicrobial peptide fowlicidin‐2 identified in chicken is a member of the cathelicidins family. The mature fowlicidin‐2 possesses high antibacterial efficacy and lipopolysaccharide (LPS) neutralizing activity, and also represents an excellent candidate as an antimicrobial agent. In the present study, the recombinant fowlicidin‐2 was successfully produced by Escherichia coli (E. coli) recombinant expression system. The gene encoding fowlicidin‐2 with the codon preference of E. coli was designed through codon optimization and synthesized in vitro. The gene was then ligated into the plasmid pET‐32a(+), which features fusion protein thioredoxin at the N‐terminal. The recombinant plasmid was transformed into E. coli BL21(DE3) and cultured in Luria‐Bertani (LB) medium. After isopropyl‐β‐D‐thiogalactopyranoside (IPTG) induction, the fowlicidin‐2 fusion protein was successfully expressed as inclusion bodies. The inclusion bodies were dissolved and successfully released the peptide in 70% formic acid solution containing cyanogen bromide (CNBr) in a single step. After purification by reverse‐phase high‐performance liquid chromatography (RP‐HPLC), ～6.0 mg of fowlicidin‐2 with purity more than 97% was obtained from 1 litre of bacteria culture. The recombinant peptide exhibited high antibacterial activity against the Gram‐positive and Gram‐negative bacteria, and even drug‐resistant strains. This system could be used to rapidly and efficiently produce milligram quantities of a battery of recombinant antimicrobial peptides as well as for large‐scale production. © 2015 American Institute of Chemical Engineers Biotechnol. Prog., 31:369–374, 2015     

肝细胞癌根治性切除术后预后因素分析

目的:探讨影响肝细胞癌患者根治性术后预后相关因素。方法:回顾性分析2004年1月1日至2009年12月31日245例我院行根治性切除术的肝细胞癌患者,采用Kaplan-Meier法和Cox比例风险模型分析临床资料、手术过程、病理特征与预后的关系。结果:多因素分析结果显示术前AFP水平、术中出血量、TNM分期是影响无进展生存时间和总生存时间的独立风险因素。术前AFP水平越高、术中出血量越大、TNM分期越晚则患者无进展生存时间及总生存时间明显缩短。此外,患者出现肿瘤组织局部坏死、门静脉癌栓,则总生存时间明显缩短。结论:术前AFP水平、术中出血量、TNM分期是外科根治性切除术后肝细胞癌患者复发及死亡的相关因素,对于临床医师判断预后及延长术后生存时间具有重要的临床意义。     

Nutrient Leaching and End Product Accumulation in Plastic Composite Supports for L-(+)-Lactic Acid Biofilm Fermentation

Investigations on the leachate bioavailability, leaching rate, and lactic acid accumulation properties of plastic composite supports (PCS) were essential for large-scale or long-term lactic acid fermentation. Leachates from PCS and polypropylene discs (controls) were analyzed by the micro-Kjeldahl method; by absorbances at 260, 275, and 280 nm; and by bioassays with Lactobacillus casei subsp. rhamnosus (ATCC 11443). The amount of leached nitrogen in a 20-ml initial soaking solution had a high correlation with the soaking solution's cell density (r = 0.87) and absorbance at 260 nm (r = 0.95). Leaching rates of various PCS were evaluated by 20 20-ml simulated repeated-batch fermentations (RBF). PCS with only yeast extract as the minor agricultural ingredient had a high leaching rate and leached out 51 to 60% of the total nitrogen during the first RBF. PCS blended with dried bovine albumin, dried bovine erythrocytes, and/or soybean flour had slowed nutrient leaching (20 to 30% of the initial leached nitrogen). Hence, they could still maintain 1 g of lactic acid per liter and measurable cell density (absorbance at 620 nm, 0.4 to 0.6) at the 20th 20-ml RBF. Lactic acid accumulation properties of PCS were evaluated by soaking the supports in a 30% lactic acid solution for 72 h at 45(deg)C. The lactic acid-soaked supports were rinsed three times and then heat treated (121(deg)C, 15 min) in 15 ml of deionized water. The results showed that lactic acid accumulation in PCS was mainly due to absorption and had no correlation with lactic acid production or biofilm formation.     

SV40 TAg转基因小鼠模型的建立及其表达

为了建立中枢神经系统肿瘤小鼠模型,构建了大鼠神经元特异性烯醇化酶(ratneu-ron-specificenolase,NSE)基因启动子调控下的猿猴病毒40大T抗原基因(simianvirus40largeTantigengene,SV40TAg)转基因载体,通过受精卵雄原核显微注射的方法制备转基因小鼠。PCR鉴定转基因小鼠的基因型;RT-PCR和Northern印迹检测转基因阳性鼠中SV40TAgRNA水平的表达及其组织特异性;免疫组化检测其蛋白质水平的表达。经显微注射共获得9只首代转基因阳性鼠(首建者,Founder小鼠),其中2例出生时即发生神经干细胞来源的肿瘤,其他Founder小鼠经繁育后共建立了5个SV40TAg转基因小鼠系,其中有4个系检测到SV40TAgRNA水平的表达且特异性地表达于脑组织,但未检测到蛋白质水平的表达。研究表明NSE启动子活性具有较强的组织特异性,并起始于小鼠胚胎发育期;SV40TAg具有明显的致癌作用,且SV40TAg诱发的神经系统肿瘤易造成转基因小鼠早期死亡。     

HrpNCSDS001基因克隆及其表达产物诱导拟南芥基因表达谱变化的研究

Erwinia carotovora subsp.carotovora CSDS001菌株具有可直接诱导烟草过敏反应特征,从构建的CSDS001菌株基因组文库,鉴定、克隆到hrpNCSDS001基因,GenBank登录号AY939927;构建的重组hrpNCSDS001基因工程菌株经IPTG诱导培养,获得的高效表达HarpinCSDS001蛋白,可诱导烟草发生过敏反应。30μg/mLHarpinCSDS001蛋白喷施拟南芥后,分析第3h、12h、24h、36h和48h拟南芥全基因谱表达动态变化,结果显示发生显著表达差异(logratio≤?1或≥1)的基因数分别为912、1787、2393、1833和1755。对被诱导发生显著表达差异的转录因子基因分析表明,有13个转录因子家族:ZIM、BES1、TCP、C2C2、AP2/EREBP、WRKY、bHLH、bZIP、GARP、MYB、NAC、HB、C2H2与HarpinCSDS001蛋白作用相关,这些转录因子家族主要参与调控植物抗性、光合作用、生长发育、开花等相关功能基因表达。