去乙酰化酶SIRT1在玉米赤霉烯酮致小鼠睾丸间质细胞氧化损伤中的调控作用

为揭示玉米赤霉烯酮(ZEA)生殖毒性的机理,试验以小鼠睾丸间质细胞系TM3细胞为对象,白藜芦醇(RSV)为激活剂,探究了SIRT1在玉米赤霉烯酮(ZEA)致小鼠睾丸间质细胞氧化损伤中的调控作用。试验分设对照组、RSV组(5μmol/L)、ZEA组(10μmol/L)、RSV+ZEA组(5μmol/L RSV+10μmol/L ZEA),处理24 h后,通过CCK-8法检测细胞活力,qRT-PCR检测细胞SIRT1基因表达,实时无标记动态细胞分析技术(RTCA)实时监测细胞指数,流式细胞术检测活性氧(ROS)水平,试剂盒检测细胞内丙二醛(MDA)含量和过氧化氢酶(CAT)活性,qRT-PCR检测细胞谷胱甘肽过氧化物酶(GSH-Px)和超氧化物歧化酶(SOD)基因表达,AO/EB染色检测细胞凋亡情况。结果显示,与对照组比,ZEA浓度为10μmol/L时能极显著抑制TM3细胞的活性(P0.01),提高细胞内MDA水平(P0.01),抑制过氧化氢酶CAT活性,晚期凋亡的TM3细胞明显增多;与ZEA组相比,RSV+ZEA组细胞活力显著提高(P0.05),SIRT1基因明显激活(P0.01),MDA水平极显著下降(P0.01),CAT活力呈现显著性上升,GSH-Px和SOD基因表达水平显著上升(P0.05),晚期凋亡的TM3细胞明显减少。结论认为,SIRT1基因的激活可减轻ZEA对小鼠睾丸间质细胞的氧化损伤作用,减少细胞的凋亡损伤,对ZEA致TM3细胞损伤具有保护作用。     

奶牛乳腺上皮细胞的分离及NAC对其氧化损伤的保护作用

为了体外分离奶牛乳腺上皮细胞(BMEC)、研究N-乙酰半胱氨酸(NAC)对BMEC氧化损伤的保护作用,试验采用组织块贴壁法获得细胞,用酶消化法和差时贴壁法纯化上皮细胞,将BMEC分别经500 ng/mL脂多糖(LPS)、500 ng/mL LPS+100μmol/L N-乙酰半胱氨酸(NAC)诱导24 h,以无添加为对照,采用比色法测定每组上清液中的丙二醛(MDA)含量、过氧化氢酶(CAT)和超氧化物歧化酶(SOD)活性。结果表明:用组织块贴壁法成功分离BMEC,添加NAC不仅能极显著降低LPS诱导后BMEC中的MDA含量(P0. 01),还能极显著提高CAT和SOD活性(P0. 01)。说明NAC对BMEC氧化损伤有一定的保护作用。     

镉对PC12细胞的氧化损伤及α-硫辛酸的保护效应

为研究α-硫辛酸（α-lipoid acid,α-LA）对镉致PC12细胞氧化损伤的保护效应,通过不同浓度的醋酸镉染毒PC12细胞,并用100μmol/Lα-LA联合作用,测定PC12细胞内超氧化物歧化酶（SOD）、过氧化氢酶（CAT）、谷胱甘肽过氧化物酶（GSH-Px）活性和丙二醛（MDA）含量。结果表明：与对照组相比,10μmol/L醋酸镉处理24h组细胞MDA含量和CAT活性极显著升高（P〈0.01）,SOD和GSH-Px活性极显著降低（P〈0.01）;不同浓度镉处理组细胞内MDA含量和CAT活性显著或极显著升高（P〈0.05或P〈0.01）,10和20μmol/L组SOD和GSH-Px活性极显著降低（P〈0.01）。α-LA保护组与相应染毒组相比,MDA含量和CAT活性显著降低（P〈0.05）,SOD和GSHPx活性有升高趋势,但组间差异不显著（P〉0.05）。说明镉可致PC12细胞发生氧化应激,α-LA可以提高PC12细胞的抗氧化能力,对镉引起的氧化损伤有一定的保护作用。     

低剂量铅对新生大鼠大脑皮质神经细胞的脂质过氧化损伤及NAC保护效应

为观察低剂量铅对新生大鼠大脑皮质神经细胞脂质过氧化的影响及N-乙酰半胱氨酸(N-Acetylcysteine,NAC)的保护作用,对原代培养的新生大鼠大脑皮质神经细胞经提取、纯化和鉴定后分9组进行染毒和保护试验.A组(对照组)、B组(铅50 μmol/L)、C组(铅50 μmol/L+NAC 50 μmol/L)、D组(铅100 μmol/L)、E组(铅100μol/L+NAC 50 μmol/L)、F组(铅200 μmol/L)、G组(铅200μmol/L+NAC 50 μmol/L)、H组(铅400 μmol/L)和I组(铅400 μmol/L+NAC 50 μmol/L),染毒时间为12 h.经超声波粉碎细胞后,测定神经细胞超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、谷胱甘肽过氧化物酶(GSH-Px)、乙酰胆碱酯酶(TChE)活性和丙二醛(MDA)含量.结果显示,与对照组比较,各染毒组GSH- Px、SOD和TChE活性显著降低(P<05),CAT活性和MDA含量显著升高P<0.05),具有明显的剂量效应;NAC拮抗组与染毒组比较,MDA含量显著降低(P<0.05),SOD、GSH-Px、TChE和CAT活性均有升高趋势,部分组间差异显著(P<0.05);结果表明,NAC能提高新生大鼠大脑皮质神经细胞的抗氧化能力,对低剂量铅暴露所引起的脂质过氧化损伤具有一定的保护作用.     

六氟双酚A对斑马鱼肝脏细胞氧化应激的影响

为研究六氟双酚A(BPAF)对斑马鱼肝脏细胞的毒性机制。试验以斑马鱼肝脏细胞为研究模型,选择不同浓度的BPAF(0、10、20、30μmol/L)作用于斑马鱼肝脏细胞系ZFL细胞,检测BPAF对ZFL细胞的细胞毒性以及细胞的抗氧化酶活性。结果表明,10、20、30μmol/L BPAF均可极显著抑制ZFL细胞的细胞活性(P<0.01);与对照组相比,10μmol/L BPAF组细胞丙二醛(MDA)含量显著提高(P<0.05),20、30μmol/L BPAF组细胞MDA含量极显著提高(P<0.01);20、30μmol/L BPAF组细胞谷胱甘肽过氧化物酶(GSH-Px)活性极显著降低(P<0.01);10、20、30μmol/L BPAF组细胞过氧化氢酶(CAT)活性极显著降低(P<0.01);20、30μmol/L BPAF组ZFL细胞超氧化物歧化酶(SOD)活性极显著降低(P<0.01)。研究表明,BPAF可通过干扰细胞的氧化应激,对ZFL细胞产生细胞毒性。     

乳酸乳球菌对Caco-2细胞抗氧化功能的影响

本文旨在研究乳酸乳球菌对氧化应激状态下Caco-2细胞抗氧化功能的影响。将培养好的Caco-2细胞分为3组:空白对照组和氧化应激组分别加入终浓度为0和100μmol/L H_2O_2,处理组在H_2O_2氧化应激条件下同时添加乳酸乳球菌(1×108CFU/m L)。培养至12 h和48 h时分别测定培养上清和细胞裂解液中的抗氧化指标。结果表明:与空白对照组相比,氧化应激12 h并没有对细胞造成明显的损伤;48 h时细胞发生了严重的氧化应激,培养上清中T-AOC(P0.05)、抗O_2-(P0.01)、GSH-Px(P0.01)和CAT(P0.05)活力均显著降低,MDA含量极显著增加(P0.01)。与氧化应激组相比,乳酸乳球菌处理12 h时显著提高了细胞培养上清中T-AOC、SOD、CAT活力(P0.01)和GSH含量(P0.01)以及细胞裂解液中SOD活力(P0.01)和GSH含量(P0.05);处理48 h时显著提高了上清中抗O_2~-、SOD、GSH-Px、CAT活力(P0.01),显著抑制了H_2O_2诱导的胞内SOD活性、GSH含量的升高和POD活性的降低(P0.01),虽然T-AOC无显著变化(P0.05),但培养上清中MDA含量显著减少(P0.01)。以上结果表明,在体外条件下,乳酸乳球菌可通过提高不同抗氧化酶活力,改善胞内抗氧化防御系统,增强Caco-2细胞抗氧化功能,减轻细胞的氧化应激损伤。     

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。     

镉对大鼠原代肝细胞的毒性损伤

用两步灌流法获得大鼠肝细胞,肝细胞暴露于浓度为2.5、5、10μmol/L的醋酸镉24 h.测定了细胞活力、培养上清液中乳酸脱氢酶(LDH)、天冬氨酸转氨酶(AST)和丙氨酸转氨酶(ALT)活性及细胞内谷胱甘肽过氧化物酶(GSH-PX)活性、还原型谷胱甘肽(GSH)和丙二醛(MDA)含量的变化.结果表明,细胞相对存活率显著下降(P<0.01),LDH、AST和ALT的释放量增加,5μmol/L和10 μmol/L剂量组与对照组相比差异均显著(P<0.01),细胞内GSH-PX活性降低,各剂量染毒组与对照组相比,差异均极显著(P<0.01);细胞内GSH含量升高,5 μmol/L和10μmol/L剂量组与对照组差异均显著(P<0.05),细胞内MDA含量升高,10μmol/L剂量组与对照组相比差异显著(P<0.05).表明镉可致肝细胞损伤,并且氧化应激起了重要作用.     

黄芪甲苷对染镉鸡脾淋巴细胞膜氧化损伤的保护作用

探讨黄芪甲苷对镉致鸡脾淋巴细胞膜氧化损伤的保护效果.设对照组、0.5%二甲基亚砜(DMSO)组、镉(10μmol/L)组和镉(10μmol/L)加黄芪甲苷(分别为5、10和20 mg/L)组,进行体外培养淋巴细胞,分别培养24、48和72 h时收集细胞,提取脾淋巴细胞膜,采用试剂盒比色法,分别检测细胞膜谷胱甘肽过氧化物酶(GSH -Px)和超氧化物歧化酶(SOD)的活性及膜丙二醛(MDA)的含量.DMSO组与对照组相比无显著性差异;镉能明显降低细胞膜GSH-Px和SOD的活性,使MDA含量增加;添加黄芪甲苷的各组中细胞膜GSH-Px和SOD的活性明显升高,MDA含量降低,其影响较为显著的是10 mg/L的黄芪甲苷质量浓度组.结果表明:黄芪甲苷可以保护染镉后鸡脾淋巴细胞膜的氧化损伤作用.     

二乙烯三胺/一氧化氮聚合物诱导的奶牛乳腺上皮细胞损伤模型的建立

泌乳期间的奶牛由于代谢旺盛,往往会产生大量一氧化氮(NO),诱导发生氧化应激,进而对细胞产生毒害作用。本试验旨在探讨二乙烯三胺/一氧化氮聚合物(DETA/NO)诱导奶牛乳腺上皮细胞(bovine mammary epithelial cells,BMEC)氧化应激的损伤条件,并建立氧化应激模型。本试验利用不同浓度(0、10、30、100、500、1 000μmol/L)的DETA/NO作为刺激源,作用BM EC 2、4、6、8、12、24 h,通过测定细胞存活率、抗氧化指标、炎症因子和NO含量及诱导型一氧化氮合酶(inducible nitric oxide synthase,i NOS)活性,筛选适宜的DETA/NO作用时间及作用浓度,建立BMEC氧化损伤模型。结果表明:1 000μmol/L的DETA/NO作用细胞6 h,细胞存活率降低为74.27%,超氧化物歧化酶、过氧化氢酶、谷胱甘肽过氧化物酶活性也均显著降低(P0.05),然而,i NOS活性,NO、白细胞介素-1、白细胞介素-6、肿瘤坏死因子-α、丙二醛含量则呈现相反的变化规律,显著升高(P0.05)。综上所述,1 000μmol/L的DETA/NO处理细胞6h,可构建理想的BM EC氧化应激模型。     

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.