Effect of a short-term infusion with soybean oil-based lipid emulsion on phagocytic responses of canine peripheral blood polymorphonuclear neutrophilic leukocytes

Background: The use of soybean oil-based lipid emulsion (SO-based LE) in parenteral nutrition has been reported to impair neutrophil functions in humans and rodents. As yet, little is understood about the effects of SO-based LE on canine immune responses.
Hypothesis: A short-term infusion with SO-based LE affects the phagocytic responses of canine peripheral blood polymorphonuclear neutrophilic leukocytes (PMNs).
Animals: Twenty-four healthy Beagle dogs.
Methods: Experimental study. Dogs were randomly assigned into groups of six and administered a 2-hour IV infusion with 0.9% NaCl solution or sufficient SO-based LE (INTRALIPOS 20%) to supply 40, 100, and 200% of the basal energy requirement (BER). PMN functions were determined after collecting blood samples before, immediately after, and 24 hours after the infusion.
Results: None of the treatments significantly affected the phagocytic capacity of PMNs or circulating leukocyte numbers. The infusion providing 200% of BERs significantly reduced PMN oxidative burst activity, filamentous actin polymerization, and Cdc42 Rho guanosine triphosphatase activity immediately after its delivery. However, these functions were restored to pre-infusion values 24 hours after the infusion. The lower calorie infusions did not have these effects.
Conclusions and Clinical Importance: These results suggest that short-term infusions with a supraphysiological dose of SO-based LE may decrease the immune functions of canine PMNs. However, more long-term studies will be needed to extrapolate the effect of SO-based LE with clinically relevant doses in a practical situation.     

家禽冷应激研究进展

冷应激是养禽业普遍存在的问题,对家禽生产性能、抗病的影响日益严重,对家禽冷应激的研究也在不断深入。本文对家禽冷应激时下丘脑-垂体-肾上腺皮质激素、下丘脑-垂体-甲状腺轴的激素(T3、T4和T4/T3)、胰岛素和胰高血糖素、血清总抗氧化能力(T-AOC)、丙二醛(MDA)的含量、肥大细胞、血液淋巴细胞数量等改变进行了综述,提出了冷应激的预防和治疗措施。通过各品种家禽在冷应激时的不同的神经-内分泌的变化规律、体内各种酶变化规律及其基因表达,培育出耐寒、抗病、抗应激并具有较高的肉品、蛋品质量的家禽品种,是提高家禽抗应激能力的有效途径。     

溪黄草对三黄肉仔鸡免疫功能的影响

为测定溪黄草对三黄肉仔鸡免疫功能的影响,将1日龄三黄肉仔鸡210只随机分为7组,每组3个重复,每个重复10只。Ⅰ组饲喂基础日粮,Ⅱ组添加0．2％恩诺沙星,Ⅲ组添加1％双黄连。Ⅳ-Ⅶ组分别在日粮上添加0．5％、1％、2％和4％溪黄草。分别测定免疫器官指数、新城疫HI抗体滴度和T淋巴细胞转化0D57。值。结果显示,溪黄草以2％剂量添加时可不同程度地刺激28日龄前三黄肉仔鸡的免疫器官发育,延长ND—HI抗体存留时间和抑制T淋巴细胞增殖,其它添加剂量对三黄肉仔鸡免疫功能也产生一定影响。     

胃肠激素GLP-1对动物生理功能的调控

胰高血糖素样肽-I(GLP-1)是一种近年发现的胃肠激素,具有促进动物胰岛素分泌,刺激生长抑素释放,抑制胃酸产生与延长胃排空等生理功能。本文主要就GLP-1的生物学特性、生理调节功能及其应用前景作一阐述。     

黄芩甙对断奶仔猪生产性能和免疫机能的影响研究

将96头杜×长×大三元杂交断奶仔猪随机分为4组,每组设3个重复。第1组为对照组,饲喂基础日粮;第2组在基础日粮中添加0.006%的喹乙醇;第3组在基础日粮中添加0.05%的黄芩甙;第4组在基础日粮中添加0.006%的喹乙醇和0.05%的黄芩甙,探讨黄芩甙与仔猪免疫机能的关系。结果表明:第2、3、4组血清中总蛋白I、gG水平与第1组相比有升高的趋势(P>0.05);第2、4组的白球比值显著低于第1组(P<0.05),3组白球比值也低于1组(P>0.05);第2、3、4组T3、C4、GH水平显著高于第1组(P<0.05),而C3、T4水平有升高的趋势,但差异不显著(P>0.05),皮质醇含量显著低于第1组(P<0.05)。试验结果表明,在早期断奶仔猪日粮中添加黄芩甙具有改善免疫机能的作用,有助于提高仔猪抗病力。     

色氨酸对产肠毒素大肠杆菌感染SD大鼠肠道的防御作用

旨在研究色氨酸对产肠毒素大肠杆菌(ETEC)感染损伤SD大鼠肠道的防御作用。本试验采用2*2双因子试验设计,将40只28日龄雌性SD大鼠,体质量(68.41±0.29)g,随机分为4组:基础日粮组(B);ETEC攻毒组(E,1.0×10^8 ETEC K88);色氨酸缺乏组(I,0.1 mL/d、10 g/L依那普利)。色氨酸缺乏+ETEC攻毒组(E+I,1.0×10^8 ETEC K88+0.1 mL/d、10 g/L依那普利),每组10个重复,每个重复1只。采用H.E染色组织切片观察、酶联免疫吸附测定(ELISA)、三重聚合酶链式反应(PCR)、免疫蛋白印迹、实时荧光定量(RT-PCR)和变性梯度凝胶电泳(DGGE)法分别对SD大鼠肠道细胞因子水平、抗菌肽表达和蛋白水平、粪便中ETEC数量以及盲肠微生物区系变化进行检测。结果表明,依那普利通过抑制ACE2酶阻碍肠道色氨酸吸收,显著降低大鼠空肠和回肠黏膜绒毛高度、淋巴细胞数量和绒毛高度/隐窝深度值(P<0.05);ETEC攻毒显著降低大鼠空肠淋巴细胞数量、绒毛高度/隐窝深度值(P<0.05)和回肠绒毛高度和淋巴细胞数量(P<0.05)。ETEC攻毒使SD大鼠粪便中ETEC数量显著增高(P<0.05)。依那普利抑制剂对SD大鼠粪便中ETEC数量无显著影响(P<0.05);依那普利通过抑制ACE2酶阻碍肠道色氨酸吸收增加空肠和回肠IL-6(P<0.05)和空肠TNF-α质量浓度(P=0.059),降低空肠TGF-β质量浓度(P=0.056);ETEC攻毒使空肠IL-6和回肠IL-6、IL-8和TNF-α质量浓度显著增加(P<0.05),降低空肠TGF-β质量浓度(P=0.059)。依那普利通过抑制ACE2酶阻碍肠道色氨酸吸收显著降低大鼠空肠和回肠Defa-5、BD-2基因mRNA相对表达量(P<0.05);ETEC攻毒使空肠Defa-5、IDO基因和回肠IDO基因mRNA相对表达量显著增加(P<0.05);依那普利通过抑制ACE2酶阻碍肠道色氨酸吸收使空肠、回肠mTOR、BD-2蛋白水平显著降低(P<0.05),使空肠TLR-4蛋白水平显著增加(P<0.05)。色氨酸缺乏、ETEC攻毒降低盲肠微生物多样性,降低拟杆菌门微生物数量,色氨酸不缺乏组盲肠微生物多样性优于缺乏组。结果显示色氨酸通过维持肠道炎性细胞因子浓度稳定、促进肠道黏膜发育和提高肠道抗菌肽基因表达改善肠道微生态环境,对ETEC感染SD大鼠肠道具有防御作用。     

脑心肌炎病毒先导蛋白结构与功能研究进展

脑心肌炎病毒(EMCV)可感染人和多种动物,其基因组先导蛋白编码区是比较保守的区域之一,含有两种高度保守的功能域,即锌指基序和酸性结构域。研究表明,先导蛋白基因组具有一定的容纳外源基因片段的能力,同时先导蛋白与病毒复制、干扰素产生以及细胞凋亡等均有关系。论文综述了EMCV先导蛋白结构与功能的研究进展。     

Immunomodulatory effect of γ‐irradiated Astragalus polysaccharides on immunosuppressed broilers

In this study, we irradiated Astragalus polysaccharides (APS) using 25 kGy ⁶⁰Co γ ray to obtain γ‐irradiated Astragalus polysaccharides (IAPS) and then investigated the effects of IAPS on growth performance and immune function of cyclophosphamide (CPM)‐treated broilers. The physicochemical properties of APS and IAPS (molecular weight, water solubility, viscosity, morphological and structural properties) were evaluated. Then, 384 one‐day‐old Arbor Acres broiler chicks with similar initial weight were randomly assigned into 6 groups: the non‐treated group (control), and CPM‐treated groups were fed either a basal diet or the diets containing 900 mg/kg APS, or 900, 600, 300 mg/kg IAPS, respectively. On days 16, 18, and 20, all broilers except for the control group were intramuscularly injected with 0.5 ml CPM (40 mg/kg·BW). Broilers in the control group were intramuscularly injected with 0.5 ml sterilized saline (0.75%, wt/vol). This trial lasted for 21 days. The physicochemical treatment showed that γ irradiation could decrease the molecular weight and viscosity, and increase the water solubility of APS (p < 0.05), whereas the structural properties of APS was not affected. In the animal trial, 900 mg/kg APS or 900, 600 mg/kg IAPS relieved the decreased growth performance, thymus index, T lymphocytes proliferation, serum IgG concentration, NOS activity and the increased blood heterophil:lymphocyte ratio in CPM‐treated broilers (p < 0.05). CPM‐induced decreases in B lymphocytes proliferation and serum IgM concentration were only increased by IAPS at 900 mg/kg (p < 0.05). Overall, both APS and IAPS alleviated CPM‐induced immunosuppression. Especially, IAPS possessed better immunomodulatory effect than APS, indicating that γ irradiation could be used as an effective method to enhance the immunomodulatory activity of APS.     

天然虾青素的生物学功能及其在动物生产中的应用

虾青素是一种酮基类胡萝卜素,具有着色、抗氧化、提高免疫力、抗癌等生物学功能。研究表明,家禽日粮中添加的天然虾青素可通过血液、肝脏和卵巢的消化、吸收与运输,最后在蛋黄中明显富集,使蛋黄颜色加深。同时因其具有羟基和不饱和酮基,可有效清除自由基,提高机体抗氧化酶活性,降低活性氧及丙二醛含量,减轻动物机体氧化应激损害。另外,天然虾青素可通过改善动物精液品质及生殖激素的分泌从而提高其生殖性能。在水产动物日粮中添加天然虾青素,不仅能增亮水产动物自身肤色,还可通过细胞免疫与体液免疫及抑制炎性因子NF-κB信号通路增强机体免疫力。文章综述了虾青素的结构特征、理化性质、提取方法和纯化,详细叙述了虾青素着色、抗氧化、提高机体免疫力、抗肿瘤等方面的功能,并分析了虾青素在畜牧与水产应用中的前景,旨在为其在畜牧生产中的进一步应用奠定理论基础。