Expression of the tobacco β-1,3-glucanase gene, PR-2d, following induction of SAR with Peronospora tabacina

Systemic acquired resistance (SAR) is induced following inoculation of Peronospora tabacina sporangia into the stems of Nicotiana tabacum plants highly susceptible to the pathogen. Previous results have shown that accumulation of acidic β-1,3-glucanases (PR-2's) following induction of SAR by P. tabacina may contribute to resistance to P. tabacina. We showed that up-regulation of the PR-2 gene, PR-2d, following stem inoculation with P. tabacina, is associated with SAR. Studies using plants transformed with GUS constructs containing the full length promoter from PR-2d or promoter deletions, provided evidence that a previously characterized regulatory element that is involved in response to salicylic acid (SA), may be involved in regulation of PR-2d following induction of SAR with P. tabacina. This work provides evidence that regulation of PR-2 genes during P. tabacina-induced SAR may be similar to regulation of these genes during infection of N-gene tobacco by TMV or following exogenous application of SA, and provides further support for the role of SA in regulation of genes during P. tabacina-induced SAR.     

花椒对蛋雏鸡生长性能及免疫机能的影响

选用1日龄海兰褐壳蛋用雏鸡320只,随机分成4组,每组4个重复,每个重复20只鸡。Ⅰ组为对照组饲喂基础日粮,Ⅱ、Ⅲ、Ⅳ为试验组,在基础日粮的基础上分别添加质量分数为0.1%、0.2%、0.3%的花椒,试验期4周,研究花椒对蛋雏鸡生长性能及免疫机能的影响。结果表明,整个试验期雏鸡的平均日增体质量试验组比对照组分别提高4.21%、12.09%、12.06%,料重比试验组比对照组分别降低1.77%、8.13%、8.11%,以Ⅲ、Ⅳ组效果最好,与对照组相比较差异显著(P<0.05);成活率试验组比对照组分别提高6.16%、7.0%、5.95%,以Ⅲ组效果最好,差异显著(P<0.05);另外,花椒对雏鸡的免疫器官也有较大的影响,其中胸腺指数试验组较对照组分别提高4.81%、9.83%、8.99%,差异显著(P>0.05);脾脏指数试验组比对照组分别提高11.29%2、0.43%和20.34%,增长差异显著(P<0.05);法氏囊指数试验组比对照组分别提高14.09%、31.28%和31.32%,差异显著(P<0.05);新城疫Hl抗体滴度试验组与对照组比较以Ⅲ组抗体效价最高,Ⅲ组较Ⅰ组差异显著(P<0.05)。从试验中可以得出添加适量的花椒具有促进雏鸡生长,提高雏鸡免疫机能的作用,以0.2%的添加量比较适宜。     

不同罗非鱼品系感染无乳链球菌后对血液和肝胰腺生化指标的影响

为探究无乳链球菌(Streptococcus agalactiae)感染后对罗非鱼的血液和肝胰腺生化指标的影响,本研究以吉富罗非鱼(Oreochromis niloticus)抗病选育系F5代、奥尼罗非鱼(Oreochromis aureus × O. niloticus)、吉富罗非鱼“百桂”品系为对象,通过人工腹腔注射感染无乳链球菌,检测感染后不同时期肝胰腺和血液中的酸性磷酸酶(ACP)、碱性磷酸酶(AKP)、过氧化氢酶(CAT)、超氧化物歧化酶(SOD)、总抗氧化能力(T-AOC)和溶菌酶(LZM)活性的变化。结果显示,奥尼罗非鱼、吉富罗非鱼抗病选育系F5代和吉富罗非鱼“百桂”品系的平均死亡率分别为55.4%、60.5%和78.6%,表明奥尼罗非鱼抗感染能力最强;3个品系感染无乳链球菌后,肝胰腺组织中的ACP、AKP、SOD和T-AOC酶活力均呈先升高后下降的趋势,其中,在感染后24 h,奥尼罗非鱼的AKP和CAT酶活力显著高于吉富罗非鱼抗病选育系F5代和吉富罗非鱼“百桂”品系;而感染后24 h,血清中ACP、AKP、LZM、CAT和T-AOC酶均显著升高,而SOD酶则下降,其中,奥尼罗非鱼的ACP、AKP、CAT和T-AOC酶活性明显高于吉富罗非鱼抗病选育系F5代和吉富罗非鱼”百桂”品系。综合比较6种酶在感染后不同时期的活性变化及3个品系的感染存活率,筛选出AKP和CAT作为评估罗非鱼抗无乳链球菌感染能力强弱的指标。     

优生素对草杂鸡生长性能及淋巴器官发育的影响

研究了优生素对草杂雏鸡生长性能和淋巴器官发育的影响。试验选用100只一日龄草杂雏鸡,随机分为两组,即对照组和试验组,50只/组。基础日粮相同,优生素按照500g/t添加到基础日粮中。试验结束时,每组随机取10只鸡解剖采集胸腺、腔上囊、脾脏等淋巴器官样品,置于Bouin固定液中固定,常规方法制作组织切片,HE染色,Olympus显微镜观察、拍照。结果表明,试验组鸡的日增重较对照组高,差异显著(p<0.05);采食量试验组鸡较对照组低,但差异不显著(p>0.05);料肉比试验组鸡较对照组低,差异不显著(p>0.05);试验组鸡的胸腺小叶皮质增厚,胸腺小体增多;腔上囊皱襞发达,退化延缓;脾脏的脾小结体积增大,脾动脉周围淋巴鞘增厚。结论,优生素可提高雏鸡日增重,提高饲料转化率,促进胸腺和腔上囊的早期发育,延缓腔上囊的退化,增强脾的免疫应答反映。     

槲皮素对免疫低下小鼠体液免疫功能的影响

本试验探讨了不同剂量槲皮素对免疫低下小鼠体液免疫功能的影响。通过氢化可的松或环磷酰胺建立免疫抑制小鼠模型,灌胃不同剂量的槲皮素。10d后测定免疫器官指数、脾脏抗体形成细胞和血清溶血素含量。结果表明,槲皮素高、中剂量组小鼠免疫器官指数、抗体形成细胞OD值及血清溶血素HC50明显高于模型组(P<0.05)。     

肠道黏膜屏障机能及其调控研究进展

肠道不仅仅是机体消化、吸收营养物质的主要场所,也是机体的一道防御屏障。肠道黏膜屏障包括黏膜生物屏障、机械屏障、化学屏障和免疫屏障,不论是哪一种肠道黏膜屏障受到损伤,都会导致机体不同程度的伤害,与一些疾病的发生密切相关。本文就肠道黏膜屏障机能及其调控研究进展进行综述,为进一步认识肠道黏膜屏障及治疗由其损伤引起的疾病提供参考和帮助。     

Mineral testing — The approach depends on what you want to find out

Extract

Comments have been made by veterinary practitioners and farmers on the appropriateness of the MAF Quality Management animal health laboratory mineral reference ranges. These ranges are designed to determine if a group of animals will respond to supplementation at the time of sampling. There are other reasons for sampling animals and this will affect the way these ranges are interpreted. We consider this fact is not clearly understood and is at least part of the reason for the questions being asked.     

农村散养猪猪瘟疫苗首免及二免效果观察

为探索农村散养猪猪瘟疫苗首次及二次免疫抗体变化规律,选择20头35日龄仔猪,35日龄首次免疫,75日龄二次免疫,用猪瘟正向间接血凝试验监测免疫抗体。结果：猪瘟疫苗首次免疫合格期为40天,二次免疫合格期达到95天以上。     

玉米胚芽分离蛋白溶解性及对小鼠免疫功能影响的研究

以湿法脱胚的玉米胚芽为原料,采用碱溶酸沉法制备了玉米胚芽分离蛋白;探讨了不同条件如温度、pH、盐浓度等对玉米胚芽分离蛋白的溶解性,解释了溶解性在这些条件下的变化的规律。研究了玉米胚芽分离蛋白对小鼠体内的免疫调节作用,研究结果表明,玉米胚芽分离蛋白能显著提高正常小鼠的免疫脏器指数、腹腔巨噬细胞的吞噬百分率、吞噬指数和淋巴细胞的转化功能活性,促进溶血素的形成。结果提示:玉米胚芽分离蛋白能提高机体的免疫功能,是一种很好的非特异性免疫激活剂。     

A Randomized Clinical Trial Evaluating Metabolism of Colostral and Plasma Derived Immunoglobulin G in Jersey Bull Calves

Background

Intravenous plasma administration has been recommended in healthy or sick calves with failure of passive immunity.

Hypothesis

IV administered plasma‐derived immunoglobulin G (IgG) undergoes increased catabolism as reflected by a rapid decrease in serum IgG concentration with an increase in fecal IgG concentrations within 48 h.

Animals

Thirty newborn Jersey calves. Fifteen were fed colostrum (CL group) and 15 were given bovine plasma IV (PL group).

Materials and Methods

Randomized clinical trial. Calves in the CL group were fed 3 L of colostrum once, by oroesophageal tubing. Calves in the PL group were given plasma IV at a dosage of 34 mL/kg. Serum and fecal samples were collected at 0 h, 6 h, 12 h, 48 h, 5 d, and 7 d. Serum and fecal IgG concentrations were determined by radial immunodiffusion.

Results

Calves in the CL group maintained serum IgG concentrations consistent with adequate transfer of immunity (≥1,000 mg/dL) throughout the study period. Calves in the PL group achieved median IgG concentrations of ≥1,000 mg/dL at 6 h but the concentrations were <1,000 mg/dL by 12 h. Calves in the PL group were 5 times more likely to experience mortality compared to the CL group (hazard ratio = 5.01). Fecal IgG concentrations were not different between the 2 groups during the first 48 h (P > .05).

Conclusions and Clinical Importance

Catabolism of plasma derived IgG occurs rapidly during the first 12 h after transfusion. Fecal excretion did not explain the fate of the plasma derived IgG.