电针诱导心肌缺血大鼠延髓头端腹外侧区nNOS和iNOS差异表达

许多研究表明,延髓头端腹外侧区(rostral ventrolateml medulla,RVLM)的NO/NOS系统参与心血管活动的中枢调节.本实验以结扎Wistar大鼠左冠状动脉前降支法建立急性心肌缺血(acute myocardial ischemia,AMI)动物模型,观察针刺"内关"穴改善AMI大鼠的心功能作用,同时检测大鼠RVLM区神经元型一氧化氮合酶(neuronal nitric oxide synthase,nNOS)和诱导型一氧化氮合酶(inducible nitric oxide synthase,iNOS)表达的变化,进而探讨针刺治疗AMI的中枢机制.实验观察显示,AMI大鼠心功能各项指标减弱,伴随外周血去甲肾上腺素(norepinephrine,NE)和脑钠肽(brain natriuretic peptide,BNP)水平显著升高,同时RVLM区nNOS阳性神经元数和nNOS mRNA表达升高,而iNOS水平则降低.针刺"内关"穴(Pe 6)(每天30 min,连续5天)改善心功能,降低AMI大鼠血清中NE和BNP的水平,同时升高iNOS并降低nNOS在RVLM的表达.以上结果提示,针刺治疗心肌缺血的同时可以调节iNOS/NO和nNOS/NO在RVLM的变化,这可能与针刺通过调节RVLM区的NO含量进而降低交感传出,从而改善AMI大鼠的心功能有关.     

Edelfosine-induced metabolic changes in cancer cells that precede the overproduction of reactive oxygen species and apoptosis

Background  

Metabolic flux profiling based on the analysis of distribution of stable isotope tracer in metabolites is an important method widely used in cancer research to understand the regulation of cell metabolism and elaborate new therapeutic strategies. Recently, we developed software Isodyn, which extends the methodology of kinetic modeling to the analysis of isotopic isomer distribution for the evaluation of cellular metabolic flux profile under relevant conditions. This tool can be applied to reveal the metabolic effect of proapoptotic drug edelfosine in leukemia Jurkat cell line, uncovering the mechanisms of induction of apoptosis in cancer cells.     

Homology modeling threedimensional structure of AnxB1 and reducing its immunogenicity by sequence-deleted mutagenesis

AnxB1,a novel annexin previously isolated from Cysticercus cellulose,shows high thrombi affinity and anticoagulant activity in vivo.In order to investigate the relationship between structure and biological function,a predicted three-dimensional(3D)model of AnxB1 was generated by homology modeling.This model contains four homologous internal-domains and the Cα trace of domain Ⅰ,Ⅱ and IV shows high similarity.Based on the structure characterization,four sequence-deleted mutants were constructed and expressed as GST fusion proteins in E.coli.Two of the mutants,GST-M3 and GST-M4 reserved high anticoagulant activity(p＜0.01 vs.GST).Furthermore,compared with the wild type GST-AnxB1,the immunogenicity of GST-M3 and GST-M4 was reduced significantly(p＜0.01)and the molecular weight was lowered to 27 kD and 34 kD,respectively.These observations laid a solid foundation for further study on developing new thrombolytic agents with higher efficiency and lower side effect.     

Exploring Health Literacy in Medical University Students of Chongqing,China: A Cross-Sectional Study

Health literacy is important in public health and healthcare, particularly in effective communication between patients and health professionals. Although most medical students will eventually work as health professionals after graduation, research on health literacy of medical students is scarce. This study aimed to assess the health literacy level of medical students in Chongqing, China, and its influencing factors. A cross-sectional study was conducted and 1,275 participants (250 males and 1,022 females) who majored in five different disciplines were involved. The Health Literacy Questionnaire was used as the survey tool. The junior students obtained the highest scores, whereas the freshman students had the lowest scores on each scale. The average score of males was higher than that of females except in “feeling understood and supported by healthcare providers,” and the average score of students who reside in urban areas was higher than that of students in rural areas. Moreover, the average score of engineering students was higher than that of medical or health sciences students. Multiple linear regression models (R_adj² = 0.435, P = 0.000) showed that the grade, socioeconomic status, and parent’s highest level of education were positively correlated with health literacy. In conclusion, the health literacy levels of the medical students are insufficient and need improvement.     

蝴蝶兰的组织培养研究

探讨蝴蝶兰的组织培养技术和方法。实验表明：改良型M1培养基诱导原球茎有良好的效果,M1 BA5．0mg/L对花梗芽的诱导最合适,Ml BA3．0mg／L对茎尖诱导原球茎最合适。降低分裂素浓度后,原球茎可以分化成完整植株,壮苗阶段以改良型M2 BA0．1mg/L NAA0．5mg／L效果较佳。移栽基质选用水苔,成活率高。     

螺旋藻的营养方式及光合作用影响因素

本文就螺旋藻的营养方式及光合作用的影响因素作了较为全面的综述。认为螺旋藻细胞不但能进行光合自养和混合营养生长 ,而且在某些特定的环境条件下 ,还能进行异养生长 ;光照强度、光质、温度、金属元素、稀土元素、盐度、藻体细胞浓度、溶氧水平、维生素、激素和磁场等环境因素对螺旋藻细胞的光合性能和细胞产率都有显著影响。     

青海柴达木盆地第四纪介形类属Ilyocypris壳面瘤状装饰的分类意义

Ilyocypris是陆相介形类的一个常见属。对其壳体外层瘤状凸起分类意义的认识历来存有争议。本文在对柴达木盆地第四纪具瘤或经常具瘤的Ilyocypris分子进行研究并初步查明其瘤状装饰分类意义的基础上,将其鉴定描述为三个种：Ilyocypris gibba,I.echinata和I.salebrosa。前者个体发育中壳瘤减少直至消失的变化及其与气候环境变迁的相关性表明,I.gibba的壳瘤发育程度是表型特征,区内原定的I.biplicata和I.bradyi实为I.gibba的无瘤类型。I.echinata的壳瘤也不具备分类意义。I.salebrosa则不同,其鲜明而巨大的后背瘤足以与Ilyocypris属的其它种区别开来,是稳定的种征。     

A novel thermostable phytase from the fungus Aspergillus aculeatus RCEF 4894: gene cloning and expression in Pichia pastoris

A novel gene of thermostable phytase, phyA, was isolated by polymerase chain reaction (PCR) techniques from Aspergillus aculeatus RCEF 4894. The full-length phyA gene comprises 1,404 bp and encodes 467 amino-acid residues, including a 19-residue putative N-terminal signal peptide. The phytase of A. aculeatus was a novel addition to the histidine-acid phosphatase family, as evidenced by both the conserved motifs RHGXRXP and HD in the amino-acid sequence, and 3D structure models. The recombinant phytase was overexpressed in Pichia pastoris, and its specific activity reached 3,000 U mL⁻¹ at the optimum pH of 5.5. This recombinant, thermostable phytase was able to withstand temperatures of up to 90 °C for 10 min, with a loss of only 13.9% of initial enzymatic activity, and showed high activity with phytic-acid sodium salt at a pH range of 2.5–6.5. The broad pH optima and high thermostability of the phytase makes it a promising candidate for feed-pelleting applications.     

番石榴果实蝇与桃实蝇的形态区别

介绍我国口岸截获频率较高的2种形态相似的实蝇---番石榴果实蝇Bactrocera (Bactrocera) correcta(Bezzi) 和桃实蝇Bactrocera zonata Saunders的鉴别特征。两者主要区别在于桃实蝇具1对卵圆形黑色颜斑,中胸背板红褐色。     

应用基因组工程构建新型大肠杆菌细胞工厂

基因组工程（genome engineering）是指为了实现某一目标对复制系统进行有意地、广泛地遗传修饰。大肠杆菌作为常用细胞工厂之一,在生物制造领域应用广泛,已成为合成生物学的主要研究对象。应用基因组工程改造大肠杆菌可以进一步拓展其应用范围。介绍了基因组工程最新技术发展,如基因组整合、染色体进化、多元自动化基因组工程、可寻迹多元重组工程等,及其在改造大肠杆菌提高其生产能力、稳定性及环境耐受能力等方面的研究进展。