镉致大鼠大脑皮质神经细胞凋亡的机理及N-乙酰半胱氨酸的保护作用

对神经细胞用不同浓度(0、5、10、20 μmol/L)醋酸镉染毒和N-乙酰半胱氨酸(NAC)(100μmol/L)进行保护,通过流式细胞仪检测了细胞凋亡率、[Ca2+]i和活性氧(ROS)水平.结果表明,与对照组相比,各染毒组细胞凋亡率、细胞内[Ca2+]i和ROS水平明显升高,呈剂量-效应关系,除5 μmol/L组ROS水平外,均差异极显著(P<0.01).添加NAC组与相应染毒组比较,神经细胞凋亡率有降低趋势,但差异不显著(P>0.05);10、20μmol/L组细胞内[Ca2+]i和ROS水平显著降低(P<0.05或P<0.01).表明镉可诱导神经细胞凋亡,其机理可能与细胞内Ca2+和ROS水平升高有关,NAC对其有一定的保护作用.     

镉对体外培养大鼠肾小管上皮细胞的毒性损伤及乙酰半胱氨酸的保护效应

在建立肾小管上皮细胞体外培养模型的基础上,通过在培养液中添加不同浓度的醋酸镉和乙酰半胱氨酸(NAC),用CCK-8法测定细胞存活率,流式细胞仪检测细胞凋亡、细胞内活性氧与线粒体膜电位,探讨了镉对体外培养大鼠肾小管上皮细胞的毒性损伤及NAC的保护效应。结果显示,作用12 h,各染毒组与对照组相比,细胞存活率和线粒体膜电位显著下降(P0.05或P0.01),细胞凋亡率、坏死率、乳酸脱氢酶(LDH)漏出率和细胞内活性氧含量均显著升高(P0.05或P0.01),呈剂量-效应关系;而NAC保护组与染毒组相比,细胞存活率和细胞凋亡率均有显著差异(P0.05),细胞坏死率无明显差异(P0.05)。结果表明,本试验所选择的镉浓度引起的肾小管上皮细胞死亡是以凋亡为主,氧化应激直接参与镉对肾小管上皮细胞的毒性损伤,NAC对肾小管上皮细胞凋亡有一定的保护效应。     

玉米赤霉烯酮致大鼠睾丸支持细胞氧化损伤及NAC的保护效应

为了揭示玉米赤霉烯酮(ZEA)雄性生殖毒性的机理及建立相应的防控措施,研究ZEA对大鼠原代培养的大鼠睾丸支持细胞(SC)的氧化损伤作用以及N-乙酰半胱氨酸(NAC)对其的保护作用,试验用不同浓度ZEA[0(对照组),5,10,20μmol/L]处理大鼠原代SC 24 h,用试剂盒法检测胞内超氧化物歧化酶(SOD)活性及丙二醛(MDA)含量,用流式细胞术检测胞内活性氧(ROS)水平,用JC-1免疫荧光探针结合流式细胞术检测线粒体膜电位(ΔΨm)等的变化;添加NAC[设0(对照组)、20μmol/L ZEA、100μmol/L NAC、20μmol/L ZEA+100μmol/L NAC等4组]保护后,检测其对以上指标的影响。结果表明:与对照组比较,10μmol/L ZEA染毒组SOD活性显著升高(P0.05),20μmol/L ZEA染毒组极显著升高(P0.01);10,20μmol/L ZEA染毒组MDA含量均极显著升高(P0.01);5μmol/L ZEA染毒组ROS水平显著升高(P0.05),10,20μmol/L ZEA染毒组ROS水平均极显著升高(P0.01);5μmol/L ZEA染毒组ΔΨm显著下降(P0.05),10,20μmol/L ZEA染毒组ΔΨm均极显著下降(P0.01)。与20μmol/L ZEA染毒组相比,20μmol/L ZEA+100μmol/L NAC联合处理组睾丸支持细胞胞内SOD活性和MDA含量显著下降(P0.05),ROS水平极显著降低(P0.01),ΔΨm极显著增高(P0.01)。说明ZEA可以造成睾丸支持细胞氧化毒性损伤,且一定浓度的NAC对这一过程具有保护作用。     

镉对大鼠大脑皮质神经细胞的氧化损伤及N-乙酰半胱氨酸的保护效应

为研究镉对新生大鼠原代大脑皮质神经细胞的脂质过氧化损伤及N-乙酰半胱氨酸(N-acetyl cysteine,NAC)的保护效应,对神经细胞用不同浓度(0,5、10、20 μmol/L)醋酸镉染毒和NAC(100 μmol/L)进行保护,检测细胞内活性氧(ROS)水平、谷胱甘肽过氧化物酶(GSH-Px)、超氧化物歧化酶(SOD)、过氧化氩酶(CAT)活性及丙二醛(MDA)含量.结果表明,与时照组比较,染毒组细胞内ROS水平、MDA含量和CAT活性极显著升高(P＜0.01),GSH-Px活性降低,20μmol/L组出现显著差异(P＜0.05);NAC保护组与相应染毒组比较,ROS水平、MDA含量和CAT活性呈不同程度降低,部分组间出现显著差异(P＜0.05);说明镉有促进神经细胞脂质过氧化的作用,NAC可提高神经细胞的抗氧化能力,对镉暴露所致的脂质过氧化损伤有一定的保护作用.     

N-乙酰-半胱氨酸对炎症反应中BV-2细胞的保护作用

为了明确N-乙酰-半胱氨酸(NAC)在LPS诱导的BV-2细胞炎症反应中的保护作用,本研究利用流式细胞术检测细胞活性氧(ROS)、超氧阴离子自由基(O_2~(·-))和线粒体超氧化物(MitoSOX)水平;ELISA和实时荧光定量PCR法检测IL-1β、IL-6和TNF-α表达;脂质氧化产物丙二醛(MDA)试剂盒检测细胞MDA含量;流式细胞术检测细胞凋亡水平。通过对细胞氧化应激、促炎因子表达、脂质损伤和细胞凋亡的检测,探讨NAC对BV-2细胞炎症反应的保护作用。结果显示,LPS可以使BV-2细胞总ROS、O_2~(·-)和MitoSOX的表达显著上升,加入NAC后ROS、O_2~(·-)和MitoSOX的水平又显著下降。LPS可使BV-2细胞IL-1β、IL-6和TNF-α的表达量显著升高,加入NAC后IL-1β、IL-6和TNF-α的表达量显著下降(P0.05)。LPS处理4 h后细胞MDA含量显著增加(P0.05),细胞凋亡水平升高,而加入NAC后MDA含量及细胞凋亡水平显著下降。结果表明,NAC可以抑制LPS引起的BV-2细胞氧化应激,使促炎因子表达减少,同时使BV-2细胞脂质损伤减弱和细胞凋亡水平下降,NAC可对细胞炎症反应中BV-2细胞起到很好的保护作用。     

lncRNA NONRATT021477.2对氧化应激条件下BRL细胞增殖和凋亡的影响

以H₂O₂诱导BRL细胞建立氧化应激型模，通过ROS和MDA试剂盒检测氧化应激的发生状态。过表达和干扰表达lncRNA 77.2后，通过流式细胞术检测细胞凋亡，CCK-8法检测细胞增殖情况。结果显示，过表达lncRNA77.2后，BRL细胞内ROS和MDA含量均极显著下降(P<0.01),细胞增殖能力增强(P<0.01),细胞凋亡率下降(P<0.01);而干扰表达lncRNA77.2后，细胞内ROS显著升高(P<0.05),MDA含量极显著升高(P<0.01),细胞增殖能力下降(P<0.01),细胞凋亡率上升(P<0.01)。结果表明，lncRNA 77.2可作为抗氧化调控因子通过抑制凋亡和氧化损伤对大鼠肝细胞起到一定的保护作用。     

乐果引起大鼠肝细胞凋亡的机理

通过给大鼠肝细胞培养液中加入乐果(0、3、10、30、100、300μmol/L),染毒122、4 h后,Annexin V/PI双染法检测肝细胞凋亡率;分别用Fluo-2/AM、双氢-乙酰乙酸二氯荧光黄(DCFH-DA)和罗丹名123检测细胞内Ca2+浓度、活性氧(ROS)和线粒体膜电位(Δψm)变化,并在扫描电镜和荧光显微镜下观察凋亡细胞情况,探讨乐果对大鼠肝细胞凋亡的影响。结果显示,肝细胞染毒12、24 h后,出现了明显的细胞凋亡的形态学变化,细胞凋亡率明显升高,除3μmol/L组外,与对照组相比差异显著(P0.05或P0.01),且呈时间-剂量效应。3μmol/L组细胞内Ca2+浓度极显著高于对照组(P0.01),之后随染毒剂量的增加,细胞内Ca2+浓度逐渐下降;细胞内ROS水平在3~100μmol/L随染毒剂量的增大和染毒时间的延长而升高,而在300μmol/L组略有下降,除3μmol/L组外,与对照组相比均差异极显著(P0.01);Δψm除24 h 300μmol/L组外均出现持续下降。结果表明,低剂量乐果染毒可诱导肝细胞发生凋亡,细胞内Ca2+、ROS和Δψm可能参与了这一过程。     

锌、NAC对镉染毒巨噬细胞的保护作用

探讨镉(Cd)对家禽巨噬细胞的毒性损伤和免疫功能的影响,以及锌、N-乙酰半胱氨酸(NAC)对Cd染毒巨噬细胞的保护作用。试验建立Cd²⁺(20,50μmol/L)染毒HD-11细胞模型,研究不同时间段(6,12 h)Cd对HD-11细胞毒性损伤,并通过向细胞培养基中补充Zn²⁺(20μmol/L)、NAC(500μmol/L)的方式,探讨Zn²⁺和NAC对Cd染毒巨噬细胞细胞骨架、细胞凋亡、ROS产生、线粒体膜电位(MMP)水平及免疫功能的影响。通过检测细胞金属元素结合原件(MTF-1)、金属硫蛋白(MT-1)基因转录水平,揭示Zn²⁺和NAC对Cd染毒巨噬细胞的调控机理。结果显示,Cd染毒造成HD-11细胞骨架蛋白降解、ROS产生、MMP水平下降、细胞凋亡增加以及IL-1β、IL-8、IL-10基因表达量降低。Zn²⁺、NAC添加能不同程度地降低Cd染毒巨噬细胞结构损伤,减少ROS产生和MMP去极化水平,增强细胞抗氧化能力和免疫功能,促进MTF-1和MT-1基因表达。结果表明...     

芝麻素对小鼠早期胚胎体外发育的影响

本试验旨研究在体外培养(in vitro culture,IVC)中添加芝麻素(sesamin,SES)对小鼠早期胚胎体外发育的影响。采集6周龄雌性昆明小鼠受精卵,随机分为对照组和不同浓度(10、50、100μmol/L) SES组。采用Fluorescein-dUTP和Hoechst 33342免疫荧光染色分别检测囊胚内细胞凋亡率和总细胞数;采用DCFH-DA检测早期胚胎内活性氧(reactive oxygen species,ROS)水平;采用CMF_2HC检测早期胚胎内谷胱甘肽(glutathione,GSH)水平;采用JC-1检测早期胚胎线粒体膜电位强度。结果显示,不同浓度SES组分裂率和囊胚率较对照组均有提高,但无显著差异(P0.05);50μmol/L SES组细胞数较对照组显著提高(P0.05),细胞凋亡率较对照组显著降低(P0.05);与对照组相比,50μmol/L SES组ROS水平显著降低(P0.05),GSH水平和线粒体膜电位水平显著提高(P0.05)。结果表明,在IVC中添加SES可提高囊胚内细胞数、减少细胞凋亡率,降低细胞内ROS水平,提高细胞内GSH水平,改善早期胚胎线粒体功能,减少胚胎氧化应激的损伤,提高小鼠早期胚胎发育质量。     

PARP-1蛋白在镉致NRK-52E细胞凋亡中的作用研究

为了探究PARP-1蛋白在镉(Cd)致大鼠肾小管上皮细胞(NRK-52E)凋亡中的作用。本研究用RTCA技术检测Cd对细胞增殖的影响,用Western Blot方法检测细胞中PARP-1与AIF蛋白的表达情况,用流式细胞术或免疫荧光的方法检测Cd与NAC或DPQ共孵育对细胞凋亡率、线粒体膜电位以及活性氧的影响。结果显示,Cd影响了细胞的增殖并上调PARP-1蛋白的表达和活性氧(ROS)的生成,抑制PARP-1的活性后细胞凋亡率下降并且线粒体膜电位与细胞内ROS的含量都恢复到相对正常水平;添加NAC处理后减弱了Cd对细胞增殖的抑制作用同时降低了细胞凋亡率。结果表明,PARP-1蛋白和氧化应激在Cd致NRK-52E细胞凋亡中发挥了重要作用。     

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.