Advanced maternal age induces fetal growth restriction through decreased placental inflammatory cytokine expression and immune cell accumulation in mice

Advanced maternal age is a risk factor for female infertility, and placental dysfunction is considered one of the causes of pregnancy complications. We investigated the effects of advanced maternal aging on pregnancy outcomes and placental senescence. Female pregnant mice were separated into three groups: young (3 months old), middle (8–9 months old), and aged (11–13 months old). Although the body weights of young and middle dams gradually increased during pregnancy, the body weight of aged dams only increased slightly. The placental weight and resorption rate were significantly higher, and live fetal weights were reduced in a maternal age-dependent manner. Although mRNA expression of senescence regulatory factors (p16 and p21) increased in the spleen of aged dams, mRNA expression of p16 did not change and that of p21 was reduced in the placenta of aged dams. Using a cytokine array of proteins extracted from placental tissues, the expression of various types of senescence-associated secretory phenotype (SASP) factors was decreased in aged dams compared with young and middle dams. The aged maternal placenta showed reduced immune cell accumulation compared with the young placenta. Our present results suggest that models using pregnant mice older than 8 months are more suitable for verifying older human pregnancies. These findings suggest that general cellular senescence programs may not be included in the placenta and that placental functions, including SASP production and immune cell accumulation, gradually decrease in a maternal age-dependent manner, resulting in a higher rate of pregnancy complications.     

几种绵羊常用粗饲料GI的测定及其代谢能模型化研究

在测定5类9种粗饲料及3个混合粗饲料的常规成分基础上,实测了它们的粗饲料分级指数(GI):大青山草地早熟禾3.4758、沙打旺3.3731、苜蓿1.7202、混粗C21.1797、青干草1.1029、混粗C10.7852、羊草0.5684、玉米青贮0.4152、玉米秸0.1985、谷草0.1728、混粗D0.0805、苏丹草0.0687,并就GI与饲料相对值(RFV)对粗饲料品质的分级进行了比较,表明GI要优于RFV,同时证明:GI还可以用于混合粗饲料的优化与牧草刈割期的确定。研究并建立了预测粗饲料代谢能(ME)的模型:ME(MJ/kg)=-11.7492 0.5959IVDM(D%)-0.0044[IVDM(D%)]2,其中IVDMD为体外干物质消化率。     

香蕉酸奶的研究

介绍了凝固型香蕉酸奶的营养成分、加工工艺及其保健作用,并对今后的研究进行了展望.     

中德两国警犬技术工作异同之我见

2009年8月28至9月17日,笔者有幸随公安部组织的警犬技术培训团前往德国,就当地警犬技术工作的开展进行了实地考察和交流。通过考察,感到德国警犬技术工作与我国警犬技术工作在训练使用方面大同小异,训练原理是基本相通的,而且德国警犬技术工作对追踪等专业领域的研究比较粗浅。但是,在一些训练方法和细节上还是有些比较独到的地方。     

假俭草的抗性

对假俭草的适应性和抗性进行了综合分析和论述,认为假俭草在耐荫性,抗病性,抗虫性,耐踏性,耐瘠薄,耐旱性,耐药性等方面表现出很强的优势,它不仅可以用于精细管理的草坪,而且能在固土护坡地段,高速公路两旁等管理粗放的地方用于建植绿化草坪。开发和利用我国野生假俭草资源具有很大价值。     

棕榈油在水产饲料中的应用

文章针对棕榈油的主要成分、生化特性以及其经济性进行了综述,并重点介绍了棕榈油作为鱼油替代油脂在几种养殖鱼类中的应用情况。与大豆油、油菜籽油等相比,棕榈油价低,产量稳定,有较高的脂肪生产力,较低的不良脂肪酸沉积。其在鲑鳟等冷水性鱼中,以不同的比例替代鱼油或与其他植物油混合替代鱼油取得了较好的效果,增加了饲料的抗氧化性。研究表明,在饲料中用棕榈油部分替换鱼油对大西洋鲑、虹鳟、欧洲鲈等的生长、体化学组成及肌肉的脂肪酸比例等没有显著影响。     

浅析畜禽遗传资源权利结构

畜禽遗传资源可以区分为畜禽遗传资源载体与信息。利用民法的所有权和国家主权对畜禽遗传资源载体与信息进行法律调整与保护,有利于对畜禽遗传资源法律属性的进一步认识,有利于对国家与农民之间权利界限进一步认识,进而有利于充分保护国家与农民双方的利益。     

Effects of training on potassium homeostasis during exercise and skeletal muscle Na+,K(+)-ATPase concentration in young adult and middle-aged Dutch Warmblood horses

OBJECTIVE: To investigate the effects of moderate short-term training on K+ regulation in plasma and erythrocytes during exercise and on skeletal muscle Na+,K(+)-ATPase concentration in young adult and middle-aged horses. ANIMALS: Four 4- to 6-year-old and four 10- to 16-year-old Dutch Warmblood horses. PROCEDURE: The horses underwent a 6-minute exercise trial before and after 12 days of training. Skeletal muscle Na+,K(+)-ATPase concentration was analyzed in gluteus medius and semitendinosus muscle specimens before and after the 12-day training period. Blood samples were collected before and immediately after the trials and at 3, 5, 7, and 10 minutes after cessation of exercise for assessment of several hematologic variables and analysis of plasma and whole-blood K+ concentrations. RESULTS: After training, Na+,K(+)-ATPase concentration in the gluteus medius, but not semitendinosus, muscle of middle-aged horses increased (32%), compared with pretraining values; this did not affect the degree of hyperkalemia that developed during exercise. The development of hyperkalemia during exercise in young adult horses was blunted (albeit not significantly) without any change in the concentration of Na+,K(+)-ATPase in either of the muscles. After training, the erythrocyte K+ concentration increased (7% to 10%) significantly in both groups of horses but did not change during the exercise trials. CONCLUSIONS AND CLINICAL RELEVANCE: In horses, the activation of skeletal muscle Na+,K(+)-ATPase during exercise is likely to decrease with age. Training appears to result in an increase in Na+,K(+)-ATPase activity in skeletal muscle with subsequent upregulation of Na+,K(+)-ATPase concentration if the existing Na+,K(+)-ATPase capacity cannot meet requirements.     

酶联免疫法检测生鲜乳中三聚氰胺的研究

用酶联免疫法对25个生鲜乳样品中的三聚氰胺残留进行检测,结果显示,离散系数小于10%,平均回收率高达97.7%,且所有生鲜乳样品的三聚氰胺含量均未超标。酶联免疫法可应用于生鲜乳三聚氰胺检测的筛选试验。