奶牛围产期脂肪因子变化对胰岛素信号通路的影响

奶牛围产期出现能量负平衡,动员体脂供能并释放游离性脂肪酸(free fat acid, FFA)是酮病的始发因素,且由于泌乳期外周胰岛素抵抗和产后胰岛素水平降低,胰岛素作为抑制FFA释放的关键激素并不能很好地发挥其生理作用。文章旨在阐述奶牛围产期与脂代谢和糖代谢相关的主要胰岛素信号通路,包括磷脂酰肌醇3-激酶(phosphatidylinositol 3-kinase, PI3K)通路、丝裂原活化蛋白激酶(mitogen-activated protein kinase, MAPK)通路等,以及脂肪因子通过这些通路对胰岛素敏感性的影响,为进一步研究酮病的发病机制及防控靶点提供理论基础。     

黄酮类化合物对免疫相关信号通路的调控作用研究进展

黄酮类化合物具有抗氧化、抗炎、保护心血管、降压、抗菌、抗病毒和抗肿瘤等多种生物活性和药理作用。近年来,黄酮类化合物的免疫调节作用也引起了相关研究人员的重视,论文就黄酮类化合物对免疫相关信号通路(NF-κB信号通路、Toll样受体和JAK-STAT信号通路等)的调控作用进行总结和归纳,以期为揭示黄酮类化合物的免疫调节作用机制研究提供参考。     

过表达IL-6对山羊毛囊干细胞增殖和迁移的影响

旨在通过在山羊毛囊干细胞(HFSCs)中过表达炎症因子白细胞介素6(IL-6),探讨其对山羊HFSCs增殖和迁移的影响,阐明MAPK/ERK信号通路在山羊HFSCs增殖和迁移过程中发挥的作用。本试验通过构建pXJ40-myc-IL-6过表达载体,瞬时转染到山羊HFSCs中,以空载体细胞为空白对照组。利用Western blot定量检测IL-6蛋白的表达,MTT法检测山羊HFSCs的增殖活力,划痕试验判定山羊HFSCs的迁移能力,最后采用Westernblot检测山羊HFSCs中MAPK/ERK和P38信号通路中关键激酶的表达水平。结果表明,将获得的IL-6过表达载体转染至山羊HFSCs3d后,与对照组比较,山羊HFSCs的增殖活力出现抑制,且抑制效果持续至第7天(P<0.05)。IL-6过表达载体转染至山羊HFSCs24h后,处理组划痕部位的愈合率达到84.2%,显著低于对照组的98.5%(P<0.01)。与对照组相比,MAPK/ERK信号通路中的关键激酶ERK1/2的磷酸化水平(p-ERK1/2)显著下调(P<0.01),P38信号通路中的关键激酶p38的磷酸化水平(p-p38)表达量上调,但差异无统计学意义(P>0.05)。综上所述,过表达IL-6基因对山羊HFSCs的增殖和迁移能力具有抑制作用,且过表达IL-6可能是通过MAPK/REK信号通路对山羊HFSCs增殖和迁移发挥负性调控作用,以上结果为揭示山羊HFSCs的迁移及组织修复机制的研究提供依据。     

miRNA与毛囊相关信号通路关系研究进展

毛囊是哺乳动物皮肤中复杂的微小器官，具有明显的生长周期，包括生长期、退行期和休止期。许多细胞因子和信号通路相互作用共同调节毛囊的发育。微小RNA(micro RNA,miRNA)是由22个核苷酸组成的非编码RNA,通过降解靶基因mRNA或抑制靶基因mRNA翻译来负向调节基因的表达。miRNA通过调控毛囊关键的信号通路，参与细胞增殖、凋亡等多种生理过程，从而促进毛囊生长。笔者综述了miRNA调控毛囊发育相关的Wnt、Notch、骨形态发生蛋白(bone morphogenetic protein, BMP)、丝裂原活化蛋白激酶(mitogen-activated protein kinase, MAPK)信号通路的最新研究进展，旨在为后续探索动物毛囊发育相关的miRNA调控机制提供理论基础。     

应激与糖皮质激素受体信号通路

近年来,集约化养殖中应激问题受到广泛关注。为了解应激对畜牧业的影响,本文主要阐述由糖皮质激素受体(GR)介导的应激通路。糖皮质激素受体介导机体应激反应存在2条主要路径:经典的信号通路,GR受配体激活改变构型,转移入核,结合到靶基因GR结合原件上,募集其他辅助激活因子修饰组蛋白、完成染色质重构,使紧缩的染色质变为松弛型,结合其他转录因子,形成转录起始复合物,启动基因转录;糖皮质激素(GC)暴露还可通过细胞质膜上的GRs限制细胞间的间隙连接(gap junction),不依赖基因转录或称为非经典的细胞信号传递,并能转化为经典信号通路。     

过氧化物酶体增殖物激活受体γ调控机体炎症信号通路的研究进展

过氧化物酶体增殖物激活受体γ(Peroxisome Proliferators-activated Receptorγ,PPARγ)是调控炎症反应的关键物质之一,其通过减弱核因子Kappa B(Nuclear Factor-kappa B,NF-κB)、c-Jun氨基末端激酶(c-Jun N-terminalKinase,JNK)活性,降低炎症因子含量从而缓解炎症反应,另一方面PPARγ与腺苷酸激活蛋白激酶(AMP-activated Protein Kinase,AMPK)互相抑制,共同维持动物正常机能。本文综述了PPARγ对动物炎症通路的调控作用,为其进一步研究和应用提供参考。     

急性冷刺激对断奶仔猪十二指肠组织结构及核转录因子-κB/肠道碱性磷酸酶信号通路的影响

本试验旨在探究急性冷刺激对断奶仔猪十二指肠肠道结构及核转录因子-κB(NF-κB)/肠道碱性磷酸酶(IAP)信号通路的影响。试验选取16头30日龄的健康"杜×长×大"三元杂交断奶仔猪,随机分为4组,每组4个重复,每个重复1头仔猪。对照组饲养于温度为(24±2)℃的环境中,3个急性冷刺激组在温度为(4±2)℃的人工气候室中分别饲养2、6和12 h。急性冷刺激试验结束后屠宰各组仔猪,取十二指肠进行固定、石蜡切片、苏木精-伊红(HE)染色,观察肠黏膜形态变化,并检测肠绒毛长度、隐窝深度,同时应用Western-blot法检测十二指肠NF-κB/IAP信号通路关键蛋白的表达情况。结果表明:对照组仔猪十二指肠结构完整,绒毛排列紧密,急性冷刺激组仔猪十二指肠绒毛出现断裂和少数上皮细胞变性脱落现象,绒毛排列稀疏。急性冷刺激12 h时,仔猪十二指肠绒毛高度与对照组和急性冷刺激2、6 h时相比显著降低(P0.05)。与对照组相比,3个急性冷刺激组隐窝深度及绒毛高度/隐窝深度均下降,但差异不显著(P0.05)。在十二指肠中,与对照组相比,急性冷刺激2 h时,p65相对表达量略有升高,但差异不显著(P0.05);急性冷刺激6 h时,p65相对表达量基本恢复到冷刺激前(对照组)水平;与对照组和急性冷刺激6 h时相比,急性冷刺激12 h时p65相对表达量显著升高(P0.05);与对照组相比,急性冷刺激2和6 h时核转录因子抑制蛋白(IκB)相对表达量有增加的趋势,但差异不显著(P0.05);急性冷刺激12 h时IκB相对表达量与对照组相比极显著增加(P0.01),与急性冷刺激2和6 h时相比也极显著增加(P0.01);与对照组相比,急性冷刺激2和6 h时磷酸化IκB(p-IκB)相对表达量略有增加,但差异不显著(P0.05);急性冷刺激12 h时p-IκB相对表达量与对照组相比极显著增加(P0.01);与对照组相比,急性冷刺激2、6和12 h时IAP相对表达量极显著升高(P0.01);与急性冷刺激2 h时相比,急性冷刺激6和12 h时IAP相对表达量极显著降低(P0.01)。结果提示,急性冷刺激损伤断奶仔猪十二指肠黏膜结构,这可能与急性冷刺激激活NF-κB/IAP信号通路,并上调NF-κB/IAP通路相关蛋白的表达有关。     

巨噬细胞极化形成的影响因素研究进展

巨噬细胞是生物体中宿主防御的重要调节者。为了满足机体不同的需要,巨噬细胞可以在不同刺激因子作用下转化为具有不同功能表型的状态,这个过程称为极化。不同影响因素下的静息巨噬细胞(M0)可极化形成不同的表型,促炎表型(M1)和抗炎表型(M2)。极化后的巨噬细胞也可通过逆转它们的表型进一步重新编程。巨噬细胞极化和重编程在维持免疫系统的稳定状态中发挥重要作用,并参与许多疾病的发生发展过程。论文对巨噬细胞极化形成的影响因素进行了论述提供参考。     

黑色素细胞调控小眼畸形相关转录因子的研究进展

黑色素细胞的主要功能是合成黑色素。黑色素是皮肤受紫外线照射后"自我保护"形成的产物,在黑色素细胞的亚细胞器—黑素小体中合成。黑色素的形成过程受到了许多基因的调控,其中小眼畸形相关转录因子(MITF)对黑色素细胞发育、增殖和存活至关重要。本文首先对MITF基因的结构和功能进行介绍,其次对MITF参与的相关分子信号通路,以及MITF在黑色素细胞的生长发育、黑色素的合成的影响进行综述,最后概述了MITF在人类中的突变影响,并对未来的研究方向进行展望。有助于探明哺乳动物黑色素的合成的分子机制,为哺乳动物毛色的形成提供理论依据。     

沙门菌通过NF-κB/β-catenin信号通路引致IPEC-J2损伤的分子机制

为研究沙门菌引致IPEC-J2损伤的分子机制,试验用沙门菌刺激IPEC-J2,在特定时间收集细胞及其培养上清液,采用荧光定量PCR或ELISA检测细胞紧密连接蛋白、炎症反应相关蛋白和细胞增殖相关蛋白的表达以及乳酸脱氢酶(LDH)含量,以确定该沙门菌能够引起IPEC-J2损伤,并进一步采用NF-κB抑制剂和小干扰RNA预...     

商会自治的基石——商会自治规范研究

在现代法律秩序中,商会自治规范是制定法的基础和必要的补充,甚至在某些方面替代了制定法;商会自治规范主要包括商会组织规范、行为规范、惩罚规范以及争端解决规范等;其效力仅及于其内部成员;商会自治规范和制定法之间存在冲突,但也存在整合的基础。     

癸氧喹酯干混悬剂含量测定的改进

采用高效液相色谱法测定癸氧喹酯干混悬剂的含量,在2-250μg/mL范围内,峰面积的常用对数与进样量浓度的常用对数呈良好的线性关系,R^2=1(n=5),平均回收率为99.24%~99.51%,RSD在0.05%~0.28%。此方法分析时间短,样品前处理简便、定量结果准确,重现性好,结果满意,为其质量控制提供了依据。     

猪毛色遗传的研究进展

本文概述了猪的毛色类型、猪的毛色遗传模式,着重综述了猪毛色基因分子基础的研究进展,指出存在问题并就未来发展方向做了思考。     

Comparison of 2 methods of centesis of the bursa of the biceps brachii tendon of horses

REASONS FOR PERFORMING STUDY: Centesis of the bicipital bursa using an 8.9 cm long spinal needle has been reported but the alternative of employing a 3.8 cm long hypodermic needle requires validation. OBJECTIVE: To compare the efficacy of 2 different methods of centesis of the bicipital bursa and to evaluate the usefulness of ultrasonographic imaging to determine the location of solution administered when centesis of the bursa is attempted. METHODS: For Trial 1, 6 clinicians, who had no previous experience of centesis of the bicipital bursa, attempted to inject a solution composed of an aqueous radiopaque contrast medium and physiological saline solution (PSS) into the bicipital bursae of 2/12 horses using the previously described distal approach to inject one bursa and a proximal approach to inject the contralateral bursa. The bicipital tendon and bursa were examined ultrasonographically before and after injection; and both shoulders were examined radiographically to identify the location of the medium. In Trial 2, another 6 clinicians, also with no previous experience of centesis, repeated Trial 1, using 6 horses, but the radiopaque contrast medium was mixed with air instead of PSS. RESULTS: Accuracy of centesis using the proximal approach was 39% and that of the distal approach 28%. Ultrasonographic examination of the shoulder allowed the location of solution and air to be accurately predicted in all 12 shoulders examined. CONCLUSIONS: Clinicians who have had no previous experience performing centesis of the bicipital bursa are unlikely to be successful in centesis using either approach. Radiographic examination after injecting a radiopaque contrast medium may be necessary to assess the success of centesis especially if bursal fluid is not obtained during centesis. Injecting air along with the radiopaque contrast medium provides more accurate ultrasonographic confirmation of centesis and better radiographic definition than does injection without air.     

不同样本商品蜂蜜中硒含量的测定

用硝酸和高氯酸消化蜂蜜,使硒游离出来,在微酸性环境下,硒和2,3-二氨基萘(DAN)生成有较强荧光的物质,用环己烷萃取,在激发波长378nm,荧光波长518nm处测定其荧光强度。蜂蜜中硒含量范围:0.10～0.82μg/g。表明:蜂蜜应视为天然富硒营养品。     

乳酸杆菌益生作用机制的研究进展

乳酸杆菌作为益生菌广泛用于人和动物。本文综述了乳酸杆菌改善宿主健康的机制。乳酸杆菌可通过产生抗菌物质如乳酸、过氧化氢、细菌素,或者通过竞争营养或肠道黏附位点来抑制致病菌;通过诱导黏附素的分泌或阻止细胞凋亡而增强肠道的屏障功能,从而保护肠道。文章重点讨论了乳酸杆菌表面成分（表面蛋白、脂磷壁酸和肽聚糖）与肠道受体（Ｃ型凝集素受体、Ｔｏｌｌ样受体和 Ｎｏｄ样受体）,阐述了他们结合后启动免疫调节信号,调控肠道免疫功能以发挥改善健康作用的机制。     

Effects of size of ingestively masticated fragments of plant tissues on kinetics of digestion of NDF

Ingestively masticated fragments were collected and sized via sieving. Different sizes of esophageal masticate and ruminal digesta fragments, and ground fragments of larger masticated pieces were incubated in vitro, and undigested NDF remaining at intervals of up to 168 h of incubation was determined. The ruminal age-dependent time delay (tau) for onset of digestion of NDF was positively correlated (P < 0.004) with the mean sieve aperture estimated to retain 50% of the fragments between successive sieve apertures (MRA). Degradation rate of potentially degradable NDF (PDF) and level of indigestible NDF were not related (P > 0.10) to MRA of masticated and ground fragments. Estimates of tau were positively related to MRA, with slopes of bermudagrass < corn silage < ruminal fragments of corn silage. It was concluded that fragment size-, and consequently, ruminal age-dependent onset of PDF degradation of a mixture of different fragment sizes results in an age-dependent rate of degradation of the more rapidly degrading of two subentities of PDF. Models are proposed that assume a tau before onset of simultaneous degradation of PDF from two pools characterized as having gamma-modeled age-dependency and age-constant rates. The ruminal age-dependent pool seems to be associated with the faster-degrading pool, and its rate parameter increases with range in MRA in the population of fragments. Conceptually, the ruminal age-dependent rate parameter for PDF degradation seems to represent a composite of several effects: 1) effects of the size-dependent tau; 2) range in MRA of the population of ingestively masticated fragments; and 3) subentities of PDF that degrade via more rapid age-dependent rates compared with subentities of PDF that degrade via age-constant rates. The estimated fractional rates of ruminative comminution of ingestively masticated fragments (0.060 to 0.075/h) were of a magnitude similar to the mean fractional rates of PDF digestion (0.030 to 0.085/h), which implies that ruminative comminution may be first-limiting to fractional rate of PDF digestion. The in vivo roles of ingestive and ruminative mastication of fragments on PDF degradation must be considered in any kinetic system for estimating PDF digestion in the rumen. These results and others in the literature suggest that the rate of surface area exposure rather than intrinsic chemical attributes of PDF may be first-limiting to degradation rate of PDF in vivo.     

Mechanism of Action of Probiotic Function of Lactobacilli

乳酸杆菌作为益生菌广泛用于人和动物.本文综述了乳酸杆菌改善宿主健康的机制.乳酸杆菌可通过产生抗菌物质如乳酸、过氧化氢、细菌素,或者通过竞争营养或肠道黏附位点来抑制致病菌;通过诱导黏附素的分泌或阻止细胞凋亡而增强肠道的屏障功能,从而保护肠道.文章重点讨论了乳酸杆菌表面成分(表面蛋白、脂磷壁酸和肽聚糖)与肠道受体(C型凝集素受体、Toll样受体和Nod样受体),阐述了他们结合后启动免疫调节信号,调控肠道免疫功能以发挥改善健康作用的机制.     

Evaluation of serum concentrations of biomarkers of skeletal metabolism and results of radiography as indicators of severity of osteochondrosis in foals

OBJECTIVE: To determine whether serum concentrations of biomarkers of skeletal metabolism can, in conjunction with radiographic evaluation, indicate severity of osteochondrosis in developing horses. ANIMALS: 43 Dutch Warmblood foals with varying severity of osteochondrosis. PROCEDURE: 24 foals were monitored for 5 months and 19 foals were monitored for 11 months. Monthly radiographs of femoropatellar-femorotibial and tibio-tarsal joints were graded for osteochondral abnormalities. Serial blood samples were assayed for 8 cartilage and bone biomarkers. At the end of the monitoring period, foals were examined for macroscopic osteochondrosis lesions. RESULTS: Temporal relationships were evident between certain serum biomarkers and osteochondrosis severity in foals during their first year. Biomarkers of collagen degradation (collagenase-generated neoepitopes of type-II collagen fragments, type-I and -II collagen fragments [COL2-3/4C(short)], and cross-linked telopeptide fragments of type-I collagen) and bone mineralization (osteocalcin) were positive indicators of osteochondrosis severity at 5 months of age. In foals with lesions at 11 months of age, osteochondrosis severity correlated negatively with COL2-3/4C(short) and osteocalcin and positively with C-propeptide of type-II procollagen (CPII), a collagen synthesis marker. Radiographic grading of osteochondrosis lesions significantly correlated with macroscopic osteochondrosis severity score at both ages and was strongest when combined with osteocalcin at 5 months and CPII at 11 months. CONCLUSIONS AND CLINICAL RELEVANCE: The ability of serum biomarkers to indicate osteochondrosis severity appears to depend on stage of disease and is strengthened with radiography. In older foals with more permanent lesions, osteochondrosis severity is significantly related to biomarker concentrations of decreased bone formation and increased cartilage synthesis.