猪繁殖与呼吸综合征、猪2型圆环病毒病二联基因疫苗的构建

将猪繁殖与呼吸综合征病毒(PRRSV)长春分离株的ORF5基因克隆至真核表达载体pIRES的CMV的启动子下游,并用猪二型圆环病毒的内蒙古分离株的ORF2基因替代pIRES的neo基因,构建真核表达质粒。通过West-ernblot以及IFA检测方法鉴定,所构建的重组质粒能在BHK细胞内进行有效的转录,并表达了目的蛋白。     

猪链球菌2型溶血素B细胞表位预测

目的预测猪链球菌2型(SS2)溶血素(SLY)B细胞表位。方法以DNAstar分析为主,综合分析二级结构、亲水性、表面可及性及抗原性指数,辅以吴玉章氨基酸抗原指数计算方法进行SS2溶血素B细胞表位预测。结果推测最有可能的B细胞表位位于溶血素N端第74～85、231～244区域位。结论应用多参数预测SS2溶血素的特征,为表位疫苗的研制奠定了基础。     

Serum chloramphenicol levels and the intramuscular bioavailability of several parenteral formulations of chloramphenicol in ruminants

Summary

Serum chloramphenicol concentrations were determined by microbiological and chemical assay methods in cows, ewes, and goats treated parenterally with seven different veterinary parenteral chloramphenicol products, including the water soluble sodium succinate ester of chloramphenicol and solutions of 20%, 25% and 50% of chloramphenicol base in various organic solvents. Serum drug concentrations were analyzed for the effect of product formulation differences, dosage, whether the drug was administered i.m. at a single body site or to two sites, and the method of assay, on the absorption from the injection site, peak drug levels, and the persistence in serum of effective concentrations of the drug i.e. 5 to 10 ug / ml. Although differences were observed among the 6 products containing chloramphenicol base in respect to absorption rate and peak serum drug levels, and although these differences significantly influenced the persistence of microbiologically‐active serum drug concentrations at the level of ≥ 10 μg / ml, they did not at the level of ≥ 5 μg / ml.

In the animal species examined, injections given at 2 sites appeared to influence the duration of predetermined serum drug levels more than the differences among the products in respect of the absorption and elimination rates from serum, the peak serum concentrations, and the dose. The shapes of the concentration‐to‐time curves in cows and ewes injected with the same dose of a given product were essentially the same, but they were different in goats. Serum chloramphenicol concentrations measured chemically after treatment with chloramphenicol base were 20% to 46% higher than those measured microbiologically.

For 60 minutes after the sodium succinate ester had been administered i.v. and i.m. to ewes, the chemically determined chloramphenicol levels were more than twice as high as the respective concentrations determined by microbiological assay, but thereafter, the magnitude of those differences was not greater than observed after treatment with chloramphenicol base.

Intramuscular bioavailability of the products containing chloramphenicol base injected at 2 sites was rather poor (51% to 80.5%ofthe dose) and even lower values were calculated after injection at a single site.

Results are briefly discussed of the effect of dosage form on the persistence of microbiologically effective serum drug levels. A dose of at least 50 mg / kg to be administered i.m. at two sites are essential prerequisits for chloramphenicol therapy in ruminants.     

Effects of Momordica grosvenori Saponins on Type 2 Diabetes Rats Induced by High-sucrose/High-fat Diet and Streptozotocin

The purpose of the experiment was to study the effect of Momordica grosvenori saponins on improving the effect of high-sucrose/high-fat diet combined with streptozotocin induced type 2 diabetes in rats.The type 2 diabetes rat model was established with a high-sucrose and high-fat diet combined with streptozotocin.Successfully modeled rats were given the total saponins of Momordica grosvenori (100,200,400 mg/kg) or metformin (268 mg/kg) by gavage,once a day for 4 weeks.Recording the "three more and one less"index (24 h internal urine output,water intake and feed intake,body weight);Detecting of biochemical indicators,analysis of fasting blood glucose (FBG),serum total cholesterol (TC),triglycerides (TG),low-density lipoprotein cholesterol (LDL-C),high-density lipoprotein cholesterol (HDL-C),insulin (INS),catalase (CAT),superoxide dismutase (SOD),malondialdehyde (MDA),alanine aminotransferase (AST),aspartate aminotransferase (ALT),blood urea nitrogen (BUN) and creatinine (Cr) levels.Hematoxylin-eosin staining (HE) was used to observe the pathological changes of the pancreas.Compared with the model group,the feed intake,water intake,urine output,blood indicators FBG,INS,MDA,TC,TG,BUN and Cr levels,AST and ALT activities were significantly or extremely significantly decreased in the total saponins of Momordica grosvenori each dose group and metformin group (P<0.05;P<0.01),while CAT,SOD activities and HDL-C level were significantly or extremely significantly increased (P<0.05;P<0.01).In pancreatic tissue,the number of pancreatic cells was increased significantly,and the pathological damage of the pancreas was significantly reduced. Momordica grosvenori saponins and metformin had obvious effects on improving glucose metabolism disorders,and at the same time could significantly reduce insulin resistance,enhance the body’s ability to resist oxidative stress and improve liver and kidney functions.     

猪圆环病毒2型LN株初步分离与全基因组测序

为了解猪圆环病毒2型(PCV-2)在河南地区猪场的流行情况,采用常规方法对采集自河南省洛阳市某猪场病料中的PCV-2进行了分离,并对其全基因组进行了扩增、克隆和测序。结果表明,从患病仔猪的病料中分离到了1株PCV-2,命名为LN株,该毒株的全基因组序列大小为1 767 bp。该试验结果为从分子水平上揭示PCV-2的致病特性,开发PCV-2的相关疫苗和诊断产品奠定了基础。     

家蚕葡萄糖-甲醇-胆碱氧化还原酶家族基因BmGMCβ2的克隆及序列与表达分析

葡萄糖-甲醇-胆碱氧化还原酶(glucose-methanol-choline oxidoreductases,GMC)家族是昆虫体内一大类以黄素腺嘌呤二核苷酸(FAD)为辅酶的氧化还原酶类,家蚕基因组中含有43个GMC家族基因。以家蚕5龄幼虫cDNA为模板克隆到一个家蚕GMC家族基因,命名为BmGMCβ2(GenBank登录号:JQ965926)。该基因cDNA全长1 875 bp,编码624个氨基酸,预测蛋白质分子质量为69.3 kD,pI为6.21,定位于家蚕16号染色体的nscaf3058上,编码蛋白质含GMC家族共有的ADP-bindingβ-α-β折叠结构域。系统发育分析表明该基因是家蚕GMC家族β亚家族基因成员。RT-PCR检测家蚕不同发育时期和5龄第3天幼虫不同组织中BmGMCβ2基因mRNA转录水平,以5龄盛食期最高,并且主要在表皮、脂肪体和气管中转录表达;Westernblotting分析BmGMCβ2蛋白主要在5龄第3天幼虫的脂肪体中表达。将BmGMCβ2克隆到原核表达载体pET-28a(+)中,转化E.coli BL21表达菌株,IPTG诱导表达BmGMCβ2融合蛋白,通过His-亲和层析得到纯化的融合蛋白并制备多克隆抗体,为后续研究该蛋白在家蚕生长发育过程中的功能奠定了基础。     

VP2蛋白Cys-402、Cys-214对猪细小病毒VLPs影响的初步研究

试验以猪细小病毒VP2 Cys-402(A)、Cys-214(B) 定点突变体为基础,将突变体真核表达载体转染COS-7细胞及核酸免疫猪细小病毒抗体阴性的小白鼠,通过电镜技术和流式细胞仪技术探讨突变Cys-402、Cys-214对猪细小病毒病毒样颗粒的影响,旨在寻找利于外源基因插入的病毒样颗粒内部位点.电镜和小白鼠核酸免疫试验结果表明:Cys-214对病毒样颗粒的组装和免疫原性的发挥是必需的,其突变后不能促使VP2形成病毒样颗粒,更不能在免疫后的小白鼠血清中监测出相应抗体的存在;而Cys-402的突变并不干扰病毒样颗粒的形成和免疫原性的发挥.由此可以推测Cys-402及其附近可能存在利于外源基因插入的位点.     

家蚕表皮基因BmGCP2的克隆及表达谱分析

从家蚕(Bombyxmori)表皮中克隆了一个高丰度表达的基因,根据其编码的氨基酸序列特征,发现是一个富含甘氨酸的表皮蛋白,将该基因命名为BmGCP2(GenBank登录号:EU980611)。进一步对BmGCP2基因进行了组织表达谱和发育时期表达谱分析,发现该基因在家蚕表皮中特异高表达,并且这种高表达一直从家蚕的胚胎发育后期持续到蛾期,表明BmGCP2基因编码的表皮蛋白是家蚕外骨骼的重要组成成分之一。     

Undernutrition in the parental and first generation provokes an organ‐specific response to oxidative stress on neonates of second filial generation of Wistar rats

Undernutrition induces an increase of the oxidative stress that can predispose offspring to various diseases in adulthood through epigenetic reprogramming. The aim of this study was to evaluate the effects of intergenerational undernutrition on protein oxidation and antioxidant defence response on liver, heart and brain of the second‐generation neonates (F₂) of undernourished rats. For this purpose, both parents in parental (F₀) and first generation (F₁) were fed with a low‐nutrient diet. Body mass and length decreased (p < 0.05) in F₀, F₁ and F₂ being the F₁ males who exhibited a greater mass loss. A decrease in plasma albumin concentration was observed in F₂ neonates (p < 0.05) and also a mass loss of liver, heart and brain (p < 0.05), although proportionally to body length reduction. Undernutrition increased levels of protein oxidation in liver and heart (p < 0.05) but not in brain (p > 0.05) while catalase activity increased only in brain (p < 0.05). In summary, intergenerational undernutrition modifies the antioxidant status through an organ‐specific response, on F₂ neonate rats, where the brain increased catalase activity to prevent a severe oxidative damage and support the vital functions of this key organ to maintain vital functions.