抵抗素样分子β在坏死性小肠结肠炎新生小鼠组织中的表达

目的 探讨抵抗素样分子β(RELMβ)在坏死性小肠结肠炎(NEC)新生小鼠组织中的表达.方法 24只新生C57BL/6J小鼠随机分为2组,NEC组行人工喂养、缺氧、冷刺激、脂多糖灌胃(5 mg/kg)造模,而对照组行母乳喂养.ELISA检测血液中RELMβ水平,Western blot检测小肠组织中RELMβ表达.结果...     

日粮赖氨酸水平对皖西白鹅繁殖力的影响

在日粮主要营养成份达标的基础上,通过调节赖氨酸水平0.49%、0.64%、0.79%,探讨其对皖西白鹅繁殖力的影响,结果表明:1赖氨酸水平影响产蛋量P<0.05,而不影响其它的繁殖力指标P>0.05;20.64%的赖氨酸水平最能体现皖西白鹅的繁殖性能。     

大鹏澳网箱养殖海域磷酸盐在沉积物-海水界面交换速率的研究

应用实验室培养法研究了大亚湾大鹏澳网箱养殖海域磷酸盐(PO_4-P)在沉积物-海水界面上的交换通量；并根据改进的连续函数法计算了PO_4-P在沉积物-海水界面上交换速率。结果表明：(1)PO_4-P在沉积物-海水界面上的交换通量随时间的变化关系满足以e为底的指数衰减函数；(2)整个调查海域PO_4-P在沉积物-海水界面上的交换速率为0．27～2．47 mmol·m~(-2)·d~(-1)。其中,网箱养殖区PO_4-P的交换速率(0．82～2．47 mmol·m~(-2)·d~(-1))明显高于对照区PO_4-P的交换速率(0．27～0．62 mmol·m~(-2)·d~(-1)),长时期的养殖活动使养殖区沉积环境中的磷得以积累,PO_4-P在沉积物-水界面上的交换速率升高。     

食品安全校内实习基地建设与管理探索与实践

食品安全校内实习基地是学生进行食品安全实习活动的重要场所。该文介绍食品安全校内实习基地建设的重点,提出实习基地管理的措施。     

Effect of simulated transport stress on the rat small intestine: A morphological and gene expression study

The present study investigated the effects of simulated transport stress on morphology and gene expression in the small intestine of laboratory rats. Sprague Dawley rats were subjected to 35 °C and 0.1×g on a constant temperature shaker for physiological, biochemical, morphological and microarray analysis before and after treatment. The treatment induced obvious stress responses with significant decreases in body weight (P < 0.01), increases in rectal temperature, serum corticosterone (CORT), serum glucose (GLU), creatine kinase (CK) and lactate dehydrogenase (LDH) levels (P < 0.01), as well as expression of Hsp27/70/90 mRNA (P < 0.05; P < 0.01). The rat jejunum was severely damaged and apoptotic after mimicking transport stress, which may mainly be related to cell death, oxidation reduction and hormone imbalance determined by microarray analysis. The bioinformatics analysis from the present study would provide insight into the potential mechanisms underlying transport stress-induced injury in the rat small intestine.     

Gene cloning of porcine adiponectin gene from adipose tissue and construction of its eukaryotic expression vector

To clone adiponectin (ADPN) gene from Shaziling porcine adipocyte and construct its eukaryotic expression vector, total RNA was extracted from subcutaneous fatty tissue. One pair of specific primers was designed by Primer 5.0 software according to the sequence of ADPN gene of porcine available in GenBank. The ADPN gene was amplified by PCR from cDNA and cloned into pMD18‐T vector to construct recombinant clonal vector pMD‐ADPN, sequenced and analysed. A recombinant expression plasmid pPICZaA‐ADPN was constructed by subcloning the cloned ADPN gene into the linearized pPICZaA vector. Then, the plasmid pPICZaA‐ADPN was expressed in Pichia pastoris (GS115) by electrotransformation. Western blot and Bradford analysis were used to determine the target protein induced by methanol. Results showed that the genome size of ADPN was 732 bp and encoded 244 amino acid, the nucleotide sequence of ADPN shared 100% identity with that of porcine available in GenBank. Western blot and Bradford analysis showed that the recombinant ADPN was expressed in GS115 correctly and has certain immune activity. The expression level of ADPN was 28.5 μg/ml. In conclusion, the recombinant ADPN could express in eukaryotic expression vector pPICZaA‐ADPN constructed in this study effectively.     

坦布苏病毒鸡源分离株全基因组及遗传变异分析

为了解引起鸡产蛋骤降的坦布苏病毒全基因组分子特征,本试验运用RT-PCR技术克隆测定了2株坦布苏病毒鸡源分离株全基因组序列,其基因组为10 990nt,包含1个10 278nt的开放阅读框架,与GenBank数据库中登录的坦布苏病毒参考株一致,与2010年以来的坦布苏病毒毒株核苷酸及推导氨基酸同源性均在98%以上,与2010年前的坦布苏病毒核苷酸和氨基酸序列同源性仅分别为88%和96%左右。基于坦布苏病毒全基因组序列的分子系统进化分析,发现2株鸡源坦布苏病毒与2010年以来分离的各种禽源坦布苏病毒株均处于同一大的进化分支,且相互间的遗传距离均小于2%。以上研究结果表明,坦布苏病毒鸡源分离株与其他禽源病毒分离株的基因组差异不明显,各分离株亲缘关系非常近。