不同蛋白质水平日粮对中国荷斯坦奶牛生产性能、氮消化和血液生化指标的影响

旨在研究饲粮不同粗蛋白质(CP)水平对中国荷斯坦奶牛乳尿素氮(MUN)、氮(N)消化及血液尿素氮(BUN)的影响。采用4×4拉丁方设计,16头经产中国荷斯坦奶牛随机分为4个处理。4个处理的饲粮能量相近,CP水平分别为12. 72%、13. 52%、14. 43%和15. 37%。试验分为4个周期,每个周期15 d,后5 d为样品收集期。奶样收集3 d,同时收集粪便,每期最后1 d晨饲前空腹采集血样。每天测量产奶量和干物质摄入量。结果:不同蛋白水平日粮奶牛干物质采食量(DMI)和产奶量组间差异不明显(P>0. 05),除了MUN随着饲粮CP水平的增加呈现增加趋势以外,其他乳成分影响不显著(P>0. 05),高蛋白质水平组MUN明显高于低蛋白组(P<0. 05)。随着饲粮CP水平的提高,氮的摄入量明显增加(P<0. 05),同时N的排泄量和消化率也不断增加,但组间无显著差异(P>0. 05)。BUN和MUN变化趋势基本一致,高蛋白质组的BUN明显高于低蛋白质组(P<0. 05),而对其他血液指标的影响不显著(P>0. 05)。在本试验条件下,不同蛋白质水平日粮能够影响中国荷斯坦奶牛MUN、BUN的变化,且两者变化趋势一致,而对产奶量、N消化率影响不明显,MUN可以代替BUN成为检测奶牛蛋白质营养状况的指标之一。     

miR-18a通过靶向结合CTGF调控猪颗粒细胞凋亡

为探究miR-18a对猪卵巢颗粒细胞凋亡的调控作用,利用生物信息学分析、荧光素酶活性检测和体外培养颗粒细胞试验验证miR-18a对CTGF的靶向作用及其在猪颗粒细胞中对CTGF基因表达的影响,并通过流式细胞技术检测其对猪卵巢颗粒细胞凋亡的调控作用。生物信息学分析结果表明,CTGF是miR-18a的潜在靶基因,荧光素酶活性检测进一步验证了miR-18a与CTGF的结合。在培养的颗粒细胞中转染miR-18a模拟物后,qRT-PCR和Western blot结果显示CTGF的mRNA和蛋白水平均显著降低,流式细胞技术检测表明miR-18a显著促进颗粒细胞的凋亡。而转染miR-18a抑制剂后,猪颗粒细胞的凋亡率显著降低,共转染miR-18a抑制剂和CTGF的干扰RNA后,颗粒细胞的凋亡率呈现回升。试验结果表明miR-18a通过靶向结合CTGF基因调控猪颗粒细胞的凋亡。     

寒冷环境下阿勒泰羊血常规指标检测

为了探讨寒冷环境下对阿勒泰羊血常规指标的影响,本试验于冬季采集30只阿勒泰羊颈静脉血进行血常规检测。结果表明,阿勒泰羊在寒冷环境下白细胞、中间细胞、粒细胞数目上升;红细胞总数、血红蛋白含量有所下降。此结果说明寒冷环境会导致阿勒泰羊体内有炎症发生,还会导致阿勒泰羊出现贫血的情况,为冬季饲养阿勒泰羊提供技术支持.     

脂肪水平对早期断奶犊牛生长性能及血清生化指标的影响

早期断奶犊牛饲喂不同脂肪含量代乳品,研究脂肪水平对犊牛生长性能、血清生化指标及饲料进食量的影响,为犊牛生长规律和脂肪需要提供科学依据,为实际生产中犊牛早期断奶和培育提供技术指导。试验选取12头新生荷斯坦公犊牛,分为EE9、EE13、EE17 3组,每组４头,分别饲喂蛋白质水平相同、脂肪含量为9%、13%及17%的3种代乳品。每日记录犊牛开食料的采食情况,并于犊牛10、20、30、40、50、60日龄清晨空腹测定犊牛体重及体尺指标,同时采集犊牛的血液样本进行分析。研究结果表明,3组犊牛哺乳期的饲料日进食量分别为706.9、666.9、569.3 g;10~60日龄的平均日增重分别为498、544、488 g,EE13组犊牛日增重高于EE9、EE17组的犊牛;犊牛60日龄时,EE13组犊牛的体高、体斜长及管围均高于其它2组。血清尿素氮、血糖、甘油三酯的水平不受代乳品脂肪含量的影响,但日龄对哺乳期犊牛甘油三酯含量的影响差异显著(P<0.05)。随日龄的增加,犊牛的生长速度和饲料的进食量逐渐增加,低脂肪的代乳品(EE9)不能满足犊牛的能量需要,高脂肪的代乳品（EE17）抑制了犊牛对开食料的采食量,饲喂脂肪含量13％的代乳品（EE13）对犊牛生长发育优于其它2组。脂肪含量对犊牛血清生化指标的影响不显著。     

Effects of B7-1 gene expression on the biological characteristics of hepatocarcinoma cells

AIM:Modification of tumor cells with B7-1 (CD80) costimulatory adhesion molecules has been proposed as a means to develop therapeutic cancer vaccines for use in human immunotherapy.METHODS:Glycosyl-phosphatidylinositol (GPI)-anchored B7-1 was transfered into QK10341 cell membranes with the plasmid of pcDNA3.1(+)/GPI-B7-1 by lipofectamine transfection. Then the GPI-B7-1 protein was isolated and purified from QK10341 cells. The SKOV3 cells incubated with GPI-B7-1 protein resulted in stable incorporation of B7-1 on SKOV3 cell membranes. Expression of B7-1 in tumors by protein transfer created an immunogenic tumor cell that induced antitumor immunity. The growth curve of T cells, the change of Fas (CD95) expression on cell membranes, and level of cytokines secreted from CTL were determined by MTT, FCM, and ELISA, respectively. The cytotoxicity alteration of the CTL was also studied.RESULTS:Compared with SKOV3 cells, B7-1-SKOV3 cells more effectively induced the proliferation of effector lymphocytes and the generation of specific lytic activity (P<0.01). The level of cytokine secretion also increased.CONCLUSION:The costimulation signal of B7-1 is required for the activation and proliferation of T lymphocytes. The B7-1 expression in SKOV3 tumor cells can increase their immunogenicity and induce more effective T lymphocytes activation.     

NIH3T3 cell proliferation and cell cycle in the conditions of hypoxia or low nutrition and its response to bFGF

AIM: To investigate NIH3T3 cell proliferation and cell cycle in the condition of hypoxia or low nutrition and its response to bFGF, and to explore the pathophysiological changes of fibroblast under hypoxic or low nutrional conditions.METHODS: The cells were placed in anaerobic workstation where the mixture gas was given to simulate hypoxic environment. Partial oxygen pressure (PO2) of medium was controlled in 27 mmHg, 44 mmHg and 175mmHg. NIH3T3 cells were cultured with low nutritional medium contained new bovine serum (NCS) less than 10% to simulate low nutritional environment. MTT assay was used for observing cell activity and flow cytometry for cell cycle analysis.RESULTS: Under 44 mmHg PO2, no obvious difference was shown between hypoxia group and normal group. Under 27 mmHg PO2, the proliferation activity of NIH3T3 cells was significantly lower than that in normal group (P<0.01), as well as the cell numbers in G0-G1 phase increased (P<0.05), S phase decreased (P<0.01). bFGF had no effect on cell proliferation. In 0.5% NCS medium, the NIH3T3 cell proliferation speed decreased (P<0.01) and cell cycle was arrested at G0-G1 (P<0.01). The proliferation speed was improved by bFGF (P<0.01).CONCLUSION: In lower PO2 or lower nutrinal condition, fibroblast proliferation activity is inhibited by cell cycle arrest in G0/G1 phase. However the decreasing proliferation in low nutritional medium could be improved by external bFGF.