锦鸡儿种子劣变过程中生理生化特性的研究

采用人工老化方法,在高温高湿(40℃、RH100%)条件下,对小叶锦鸡儿(Caragana microphlla Lam.)和柠条锦鸡儿(Caragana korshinskii Kom.)的种子进行劣变处理.同时重点测定和分析生理生化指标.结果表明:高温高湿(40℃,100%RH)人工老化法的最佳处理时间梯度为0、8、16、24、36、48 h.两种供试种子发芽率和发芽指数显著下降(P＜0.05);酸性磷酸酯酶活性显著降低(P＜0.05),与种子发芽指教呈极显著正相关,是反映其种子质量的敏感指标;可溶性糖泄漏和脂质过氧化,是种子劣变的重要原因.     

驴肉在低温成熟过程中理化特性及抗氧化性能的变化规律

为研究驴内在低温成熟过程中理化特性及抗氧化性能的变化规律,选择10头育肥德州公驴,屠宰后取背最长肌,在0～4℃低温环境下熟化72 h,分别在0、1、6、24、48和72 h测定驴肉理化指标和抗氧化指标.结果 表明,驴肉pH在72 h内低温成熟期间发生极显著变化(P＜0.001),且随着时间的延长呈现显著的一次线性下降(...     

不同棉花品种种子活力对低温和人工老化胁迫的反应差异

为探讨棉花种子活力的品种差异及不同种子活力测定方法对棉子活力结果的影响,以17个棉花主栽品种(系)为材料,用简化的标准发芽、低温发芽和人工老化发芽3种方法测定棉花种子活力,并分析种子物理性状与种子活力的相关性。结果表明:3种活力测定方法下不同品种间种子活力均存在较大差异,各活力指标表现趋势也不一致,低温条件主要抑制种子幼苗的生长势,老化条件则主要抑制种子的发芽率。简化的标准发芽的活力指数与2种逆境发芽下的活力指数间的相关性较低。对3种测定方法的种子活力指标进行聚类分析,筛选出中棉所102、新陆中42、湘杂7号、XG39K5、屯杂6号及皖杂9号等高活力品种。低温和人工老化发芽条件显著降低了种子活力与种子各物理性状间的相关性。种子密度和健子率在不同发芽条件下均与种子活力关系最密切,可作为判断棉花种子活力大小的物理指标。     

The effects of aging on hematology and serum chemistry values in the beagle dog

To distinguish age-related changes in hematology and clinical chemistry values from those resulting from disease, hematology, and clinical chemistry values of healthy, age-matched Beagle dogs 3 to 14 years of age were analyzed. Serum potassium, total protein and globulin concentration, and lactic dehydrogenase activity increased with age, while urea nitrogen, creatinine and albumin concentration, and gamma-glutamyl transferase activity decreased. The 12-year-old group had some distinct differences from the other age groups: glucose concentration was lower, alanine aminotransferase and aspartate aminotransferase activity and triglyceride concentration were higher. No significant age-related differences were found in the hematology parameters analyzed. This report extends the documented, age-related changes in normal Beagle dogs to 14 years of age. The age-related changes in organ-specific serum chemistries such as urea nitrogen and creatinine (kidney), and alanine aminotransferase (liver) noted here suggest that 12 years may be a pivotal age for determining longevity in the Beagle dog.     

Age-related changes in leukocytes and T cell subsets in peripheral blood of Japanese Black cattle

It is well known that the immune system changes with age during development and maturation in Holstein cattle. But age-related changes in leukocytes and T cell subsets in peripheral blood of Japanese Black cattle still remain unclear. The aim of the present study was to investigate comparative changes of leukocytes (granulocytes, monocytes, B cells and T cells) and T cell subsets (CD4⁺, CD8⁺, γδ, CD8⁺γδ and WC1⁺γδ T cells) in Japanese Black cattle aged 0.5, 1, 2, 6, 18 and 36–41 (adult) months on flow cytometry using specific monoclonal antibodies for the cell surface markers. T cell proportion was approximately 40% in 2-month-old cattle and decreased to 20.6% in adults. In contrast, B cell proportion significantly increased from 7.4% to 28.2% with age. In T cell subsets the percentage of CD4⁺ T cells significantly increased from 40.5% to 60%, but that of WC1⁺γδ T cell subset significantly decreased with age. The percentages of CD8⁺ and CD8⁺γδ T cells did not change. The present study details the proportional changes in leukocyte and T cell subsets with age in the peripheral blood of Japanese Black cattle and these findings are similar to those described for Holstein cattle.     

应用端粒长度推断个体年龄的研究进展

细胞衰老机制是细胞生物学研究的一个重要课题。随着端粒及端粒酶与细胞衰老和年龄增长关系的揭示,端粒长度的缩短已经成为细胞衰老和年龄增长的生物学标志之一。作者首先介绍了端粒和端粒酶的结构、功能,进而分析其与细胞衰老、年龄增长的关系,并对端粒和端粒酶在年龄推断中的应用研究加以综述。     

Senescence of endothelial cells and gene expression associated with apoptosis induced by angiotensinⅡ

AIM: To study the senescence of human umbilical vein endothelial cells (HUVECs) and Bcl-2, Bax gene expression associated with apoptosis induced by angiotensinⅡ (AngⅡ).METHODS: HUVECs were cultured in vitro and the cell viability was observed by methyl thiazolyl tetrazolium (MTT). HUVECs were intervened by AngⅡ and valsartan (AngⅡ type 1 receptor blocking) and divided into 3 groups: the control group, AngⅡ group (stimulated with AngⅡ10^-6mol/L for 48 h), valsartan group (valsartan was added to cells 1 h before 10^-6mol/L AngⅡ treatment). β-gal staining and cell cycle analysis were used to identify the cell aging status. Morphologic changes and percentage of apoptosis were assayed with Hoechst33258 under fluorescent microscope. The expressions of Bcl-2 and Bax, and the apoptosis-associated genes were detected by immunocytochemical staining, RT-PCR and Western blotting. RESULTS: The cell viability by AngⅡ-induced cells was (81.9%±4.1)%, the positive cell number of β-gal staining was significantly higher in AngⅡ-induced cells (80.10%±6.81)% than that in the control cells. The cell cycle was at G₀-G₁(91.36%±6.45)%, the apoptotic cells significantly increased (31.84±2.86)% under fluorescent microscope. In valsartan group, Bcl-2 mRNA and protein expression increased markedly (P<0.05), but Bax mRNA and protein expression decreased evidently (P<0.05) compared to those in the AngⅡ group.CONCLUSION: Cell apoptosis is possibly an important factor for endothelial cell senescence and vascular aging induced by AngⅡ. One of its molecular mechanisms might be associated with decreasing the expression level of Bcl-2 and increasing that of Bax, which regulate the imbalance between mRNA and protein expression of Bcl-2 and Bax. Valsartan improves endothelial cell aging.     

Partial autolysis of μ/m‐calpain during post mortem aging of chicken muscle

The objective of this study was to investigate changes occurring in μ/m‐calpain in post mortem chicken muscles and to determine the origin of the unknown bands found in calpain casein zymography. The unknown bands were reported with slightly greater mobility compared to conventional μ/m‐calpain bands in casein zymography. Identification of these bands was accomplished using native polyacrylamide gel electrophoresis, liquid chromatography tandem mass spectrometry and with protein phosphatase treatment. Results showed that the unknown bands were corresponding to μ/m‐calpain, and dephosphorylation by protein phosphatase did not change their appearance. The calpain samples were then incubated with various concentrations of Ca²⁺ to determine the relationship between changes in μ/m‐calpain and the appearance of the unknown bands. The products of μ/m‐calpain partial autolysis were found to be consistent with the appearance of the unknown bands. Therefore, the appearance of these bands did not result from phosphorylation of μ/m‐calpain as previously hypothesized, but from partial autolysis of μ/m‐calpain. Also their presence suggests that μ/m‐calpain undergoes partial autolysis during aging which may play certain roles in meat quality improvement.     

陈化玉米及谷胱甘肽酵母粉对断奶仔猪生长性能、养分表观消化率、血清抗氧化和免疫指标的影响

本试验旨在研究陈化玉米对断奶仔猪生长性能、养分表观消化率、血清抗氧化和免疫指标的影响,以及添加谷胱甘肽酵母粉对上述指标的改善效果。选取28头(25±1)日龄的杜×长×大断奶仔猪,按体重相近原则随机分为4组,分别为对照组(基础饲粮)、谷胱甘肽酵母粉组(基础饲粮+0.5%谷胱甘肽酵母粉)、陈化玉米组(由陈化玉米100%替代基础饲粮中的正常玉米)和陈化玉米+谷胱甘肽酵母粉组(陈化玉米组饲粮+0.5%谷胱甘肽酵母粉),每组7个重复,每个重复1头猪,单笼饲养。试验期42 d。结果显示:1)陈化玉米和谷胱甘肽酵母粉对断奶仔猪各阶段的平均日增重和平均日采食量均无显著影响(P>0.05)。与对照组相比,陈化玉米组试验第1～14天、第14～28天、第1～28天和第1～42天料重比显著降低(P<0.05);添加谷胱甘肽酵母粉有降低第1～28天料重比的趋势(P=0.091)。2)与对照组相比,陈化玉米组干物质、粗灰分、有机物和粗蛋白质的表观消化率显著提高(P<0.05);添加谷胱甘肽酵母粉有提高粗蛋白质表观消化率的趋势(P=0.066);陈化玉米和谷胱甘肽酵母粉的交互作用有影响粗脂肪表观消化率的趋势(P=0.083)。3)与对照组相比,陈化玉米组血清丙二醛(MDA)含量显著提高(P<0.05),而血清总抗氧化能力(T-AOC)及谷胱甘肽过氧化物酶(GSH-Px)、过氧化氢酶(CAT)和总超氧化物歧化酶(T-SOD)活性无显著变化(P>0.05);添加谷胱甘肽酵母粉显著降低血清MDA含量(P<0.05),显著提高血清T-SOD活性(P <0. 05),并有改善血清GSH-Px活性的趋势(P=0.083)。4)相对于正常玉米,陈化玉米有提高血清尿素氮(UN)含量的趋势(P=0.050);添加谷胱甘肽酵母粉有降低血清总胆固醇(T-CHO)(P=0.096)和甘油三酯(TG)含量的趋势(P=0.086)。5)相对于正常玉米,陈化玉米显著降低了血清溶菌酶(LZM)活性(P <0.05);添加谷胱甘肽酵母粉显著增加血清补体3(C3)的含量(P <0.05),有增加血清LZM活性的趋势(P=0.099)。在本试验条件下,陈化玉米相对于正常玉米可显著降低断奶仔猪料重比,显著提高饲粮干物质、粗灰分、有机物和粗蛋白质的表观消化率,同时会降低仔猪的血清抗氧化能力和免疫功能,而添加谷胱甘肽酵母粉能在一定程度上缓解陈化玉米的负面效应。