Diurnal and individual variations in bile acids in the plasma of normal dairy cows

Blood samples were collected every 2 h during a 24 h period from 6 cows of one herd and 10 cows of another herd. In a third herd 9 cows were sampled every 2 h from 6 a.m. to 8 p.m. Concentrations of total bile acids, acetoacetate, glucose and free fatty acids were determined in blood plasma. A marked difference in individual bile acid concentrations and patterns of diurnal variation was found. For most cows the highest bile acid values were observed between 2 and 6 a.m. (overall mean (+/- SD) at 6 a.m.: 104 +/- 84 mumol/l, range: 20-307 mumol/l). Fourteen cows with a bile acid value greater than 90 mumol/l at 6 a.m. ("high BA") were characterized as a group by showing a pronounced decrease in the mean bile acid concentration after morning feeding. In the group of 11 cows with a 6 a.m. bile acid value less than 90 mumol/l ("low BA") the time of day did not contribute significantly to the bile acid variation. For the "high BA" group a nearly synchronous variation between the mean values of the 3 feeding dependent parameters (acetoacetate, glucose and free fatty acids) and the mean values of bile acids was found. The within animal coefficients of correlation between bile acids and the feeding dependent parameters were significantly higher in the "high BA" group than in the "low BA" group. No direct connection was found between bile acid levels and the quantity of concentrates fed or the individual milk yield.     

外源绿原酸对苹果抗病相关酶的影响

采用离体培养方法对富士、红星和八棱海棠进行绿原酸处理,研究苹果在外源绿原酸处理下POD、PPO、PAL活性的动态变化以及绿原酸含量的变化。结果表明,富士以0.0001%绿原酸、红星以0.0008%绿原酸、八棱海棠以0.0004%绿原酸处理后,其PAL活性均显著提高,苹果体内也因此而提高了绿原酸水平。     

Association of hyponatremia and hyperglycemia with outcome in dogs with congestive heart failure

Objective: To evaluate plasma sodium and glucose concentrations in dogs with congestive heart failure (CHF) prior to treatment and evaluate the differences between survivors and non‐survivors. Design: Retrospective study. Animals: Fifty‐nine dogs with CHF prior to receiving cardiac medication. Interventions: None. Measurements and main results: The mean plasma sodium concentration in dogs with CHF was below the reference range (144–156 mmol/L) and significantly lower (P=0.009) in non‐survivors (141±6 mmol/L) compared with survivors (147±4 mmol/L). The mean plasma glucose concentration was above the reference range (76–117 mg/dL) and significantly higher (P=0.004) in non‐survivors (128±52 mg/dL) compared with survivors (100±13 mg/dL). Forty‐four percent of non‐survivors had concurrent low plasma sodium and high plasma glucose concentrations, whereas no survivors had both abnormalities (P<0.0001). Conclusions: Lower plasma sodium and higher plasma glucose are associated with a worse outcome in dogs with CHF.     

饲料中维生素A对青鱼幼鱼生长、血清生化指标和肝脏糖脂代谢酶活性及基因表达的影响

为研究饲料中维生素A(VA)对青鱼幼鱼生长、血清生化指标和肝脏糖脂代谢相关酶活性及基因表达的影响,实验选取360尾初始体质量为(6.10±0.10) g的青鱼幼鱼,随机分配至3个实验组中,每个实验组设置3个平行。采用单因素实验设计,以无维酪蛋白和明胶为蛋白源、菜籽油为脂肪源、糊精为糖源,同时添加矿物质混合物和维生素混合物(无VA添加)配制成3组实验饲料,分别以饲料1 (Diet1)、饲料2 (Diet2)和饲料3 (Diet3)表示。在饲料1、饲料2和饲料3中分别添加0、2 200和20 000 IU/kg VA醋酸酯(500 000IU/g),经高效液相色谱法(Agilent-1100, Agilent,美国)检测后实验饲料中VA的实际含量分别为178.2、2 058.9和18 436.2 IU/kg,养殖周期为8周。结果显示:饲料中VA缺乏会显著降低青鱼幼鱼的增重率(WGR)和特定生长率(SGR);VA缺乏会显著降低血清血糖(GLU)、甘油三酯(TG)和低密度脂蛋白(LDL)浓度,增加总胆固醇(TCH)浓度。饲料中添加2 058.9IU/kg VA能显著提高肝脏己糖激酶(HK)、磷...     

豇豆与锈菌互作中的多酚氧化酶和过氧化物酶活性及其与抗性的关系

测定了具有不同抗性水平的5个豇豆Vigna sesquipdalis Wight品种在受锈菌Uromyces vignae Barcl侵染前和侵染后的若干阶段中的多酚氧化酶(PPO)和过氧化物酶(POD)活性,并分析其与抗性的关系.结果表明,在接种后24h内,免疫和抗病品种的PPO比活性及其变化率均高于感病品种,且前者PPO比活性变化率高峰出现早,后者出现迟.在接种后,各品种的POD比活性及其变化率均上升,但中抗和感病品种的高峰出现早,免疫和高抗品种出现晚.此外,中抗和感病品种的POD比活性及其变化率在接种12h左右出现高峰后立即下降,而高抗品种的则持续上升至24h左右出现高峰,免疫品种的POD比活性也在24h左右出现高峰,但其POD比活性变化率则持续到48h左右达到高峰,且免疫和抗病品种的峰值明显大于感病品种.     

口服和静脉注射重组hGLP-1类似物对糖尿病大鼠的影响

目的观察口服和静脉注射重组hGLP-1类似物对糖尿病大鼠血糖、胰岛素及胰岛组织病变的影响。方法用链脲佐菌素（STZ）建立SD大鼠糖尿病模型,随机分为模型组、灌胃组和注射组,每组10只,分别给予生理盐水灌胃、重组hGLP-1类似物多肽灌胃、hGLP-1类似物基因重组载体尾静脉注射,观察4周内各组大鼠血糖、胰岛素、胰岛组织病理变化。结果与模型组比较,灌胃组和注射组的血糖水平在给药后1～4周明显下降,而血清胰岛素水平显著升高（P〈0.01）。灌胃组在各时间点的血糖、胰岛素水平与注射组相比,差异无统计学意义（P〉0.05）。HE染色发现,灌胃组和注射组大鼠的胰岛组织病变有所改善。结论重组hGLP-1类似物可降低糖尿病大鼠的血糖、提高血清胰岛素水平。     

亚砷酸氧化菌Sinorhizobium sp. GW3的鉴定与亚砷酸氧化酶基因的分离

亚砷酸氧化细菌能够将毒性大的As(Ⅲ)氧化成毒性小的As(Ⅴ),在生物修复砷污染方面具有应用价值。对一株新型亚砷酸氧化菌Sinorhizobium sp.GW3进行了较全面的鉴定,并分离及分析了亚砷酸氧化酶基因aoxAB。形态学、生理生化鉴定和16S rRNA基因等分析结果表明该菌为Sinorhizobium属。该菌对As(III)抗性的MIC(Minimum inhibitory concentration)为9 mmol/L。首次在Sinorhizobium属中分离了包括编码小亚基aoxA和大亚基aoxB在内的亚砷酸氧化酶基因,其编码的大小亚基与已发现的Agrobacterium tumefaciens(ABB51929)的大小亚基在氨基酸水平上分别有86%、80%的同源性。     

补铜对铜缺乏奶牛血浆7项生化指标的影响

选择10头患铜缺乏症泌乳奶牛,每头牛内服硫酸铜4 g.d-1,每周1次,连续服用2周,测定补铜前后奶牛血浆Cu、SOD、BUN、Glu、TP、T-AOC、MDA含量。结果显示:试验奶牛补铜后,血浆BUN、TP、SOD水平略高于补铜前(P0.05),血浆Glu、Cu、T-AOC水平明显高于补铜前(P0.05或P0.01),血浆MDA水平显著低于补铜前(P0.01)。结论:补铜能有效的改善铜缺乏奶牛机体能量代谢和抗氧化能力。     

薇甘菊萎蔫病毒感染对薇甘菊光合特性和4种酶活性的影响

为明确薇甘菊萎蔫病毒(Mikania micrantha wilt virus,MMWV)对薇甘菊(Mikania micrantha)叶片生理生化的影响,探讨了MMWV侵染对薇甘菊叶片超氧化物岐化酶(superoxide dismutase,SOD)、过氧化物酶(peroxidase,POD)、多酚氧化酶(polyphenol oxidase,PPO)和苯丙氨酸解氨酶(phenylalanine ammonia-lyase,PAL)活性及叶绿素总含量和光合特性的影响.结果表明:MMWV感染薇甘菊16d内叶片的SOD活性均比对照组高,其中第16天达最大值,但接种后第24和32天SOD活性分别比对照低了13.28％和25.37％;POD活性在接种后16-32d均显著高于对照.PPO和PAL变化趋势相似,在接种后第8天这两个酶的活性分别比对照高了77.75％和23.58％,而在第32天分别比对照减少了14.27％和20.53％.随着侵染时间的增加,感病薇甘菊叶片中叶绿素含量减少,叶绿素a/b值逐步降低;同时最大净光合速率(Pmax)和光饱和点(LSP)分别比健康对照减少了32.34％和12.52％,而对暗呼吸速率(Rd),光补偿点(LCP)和表观量子效率(AQY)无显著影响.表明MMWV侵染可减低薇甘菊叶片光合作用的效率.