影响反刍动物产品中共轭亚油酸富集因素的研究进展

共轭亚油酸(CLA)又被称为过瘤胃脂肪酸。近年来,随着CLA对人体健康的重要作用被陆续发现,通过饲养途径如何提高反刍动物产品中CLA含量成为当前动物营养研究领域的热点。本文在查阅国内外CLA最新研究进展的基础上,对影响反刍动物产品中CLA合成的因素加以综述。     

Serum vascular endothelial growth factor in dogs with soft tissue sarcomas

This work aimed to evaluate serum vascular endothelial growth factor (VEGF) in 25 dogs with soft tissue sarcoma, and in 30 healthy dogs. Blood was collected once time from the control animals and three times, in the same way, from animals with sarcoma. Blood count was performed in the blood collected, and serum VEGF was measured by enzyme‐linked immunosorbent assay quantitative method. Serum VEGF in control animals was similar to patients with soft tissue sarcoma. There was a reduction in serum VEGF after the sarcoma resection. There was positive correlation between serum VEGF and neutrophil counts, and negative between VEGF and hemoglobin content in animals with sarcoma. Animals with hemangiopericytoma showed higher serum VEGF levels compared to the patients with malignant peripheral nerve sheath. Circulating blood cells can contribute to elevate VEGF serum concentrations in dogs with soft tissue sarcomas and a possible role of VEGF in the angiogenesis of these tumors.     

黄河三角洲新生湿地不同植被类型土壤的微生物分布特征

为探明黄河三角洲新生湿地土壤微生物分布特征,选取盐地碱蓬(Suaedasalsa)、柽柳(Tamarix chinensis)、芦苇(Phragmites communis)和拂子茅(Calamagrostis epigeios)4种湿地植被土壤,分春、夏、秋3个季节对其中细菌、真菌和放线菌数量组成和分布特征进行了研究。结果表明:不同植被类型湿地土壤中各类微生物数量差别明显,但总体上均偏少,而且优势种类非常明显,以细菌为主,放线菌居中,真菌最少;不同微生物数量上具有明显的季节分布特征,除拂子茅湿地细菌群落外,其他各群落数量均为夏季高,春、秋低;湿地土壤中微生物总量分布存在明显的根际效应,其中细菌的根际效应最为明显;土壤中氮和磷(总氮、总磷、速效氮、速效磷)含量对细菌的数量影响最明显;真菌分布与氮的含量关系密切,但与磷素关系不大;放线菌分布与氮含量相关性小,与磷素呈负相关;微生物数量与土壤pH值和电导率呈一定程度的负相关。本区土壤微生物分布与植被类型、土壤盐分和养分关系密切,且具有明显的季节动态。     

河北省承德市接坝地区畜间包虫病感染风险因素研究

为寻找河北省承德市接坝地区牛羊群包虫病潜在风险因素,对承德市接坝地区23个乡镇的184个养殖户进行风险因素问卷调查,并分析调查结果。结果显示,牛羊养殖方式粗放、犬粪不进行无害化处理、犬密切接触羊牛群、驱虫后没有对犬进行拴养是包虫病感染的重要风险因素。通过Hosmer-Lemeshow检验,证明建立的Logistic回归模型拟合较好。结果表明,养殖户加强牛羊管理,对犬合理驱虫,限制散养犬接触牛羊群对于降低包虫病感染风险具有重要意义。     

裸果木种群遗传多样性特点及与地理气候因子关联研究

本文利用ISSR标记技术,选取15对引物,对分布于西北荒漠区12个裸果木种群的遗传多样性以及与地理气候因子的相关性进行了分析。结果表明：群体内多态性位点百分率（PPL）为88.81%,种群水平为69.93%;Nei’s基因多样性指数（He）变化范围为0.2356~0.2697,Shannom信息指数（I）变化范围为0.3509~0.4057,具较高的遗传多样性水平。基因分化系数（Gst）为0.2790,种群间遗传分化较小,种群内存有丰富的遗传变异。经Mantel检验,种群遗传距离与地理距离有相关性（R²=0.2144）。利用NTSYSpc-2.1软件进行UPGMA法聚类,各种群样品间的遗传相似系数在0.81～0.99之间,按照遗传距离远近,裸果木12个种群可分为4大类群。经相关性分析,种群遗传多样性与纬度、海拔存在正相关（P<0.05）与年均温存在负相关（P<0.05）。     

甘南夏河高寒草甸高原鼢鼠和高原鼠兔秋季栖息地特征

2010年至2014年连续5年对甘南夏河高寒草甸高原鼢鼠(Eospalax bailyei)和高原鼠兔(Ochotona curzoniae)的分布与其地形、植被因子等进行了调查,分析两小型哺乳动物秋季越冬前的栖息地利用特征。结果表明,其秋季栖息地利用与地形和植被特征显著相关。高原鼠兔易选择坡地、半阳坡和坡中位的地形,而高原鼢鼠易选择平地、阳坡和坡底位的地形;植被盖度是影响高原鼠兔分布的重要因子。地上生物量非中等的平地是两小哺乳动物共存的主要分布地,两小型哺乳动物的种群动态与植被盖度和生物量均显著相关(P0.05);鹅绒委陵菜(Potentilla anserina)、花苜蓿(Melissilus ruthenicus)、柴胡(Radix bupleuri)和美丽风毛菊(Saussurea pulchra)4种植物多度与两小型哺乳动物的分布显著相关。     

Delivery of growth factors using gene therapy to enhance bone healing

OBJECTIVE: To review the delivery of growth factors using gene therapy for enhancing long-bone fracture healing. STUDY DESIGN: Literature review. METHODS: MEDLINE and CAB Abstracts literature search (1980-2004). RESULTS: Non-union and infected non-union are relatively common complications of long-bone fractures in human and veterinary patients. Growth factors are cytokines that regulate many cell functions important in fracture healing. Exogenous growth factors can be delivered to the fracture site as recombinant proteins or using gene therapy. Recombinant human bone morphogenetic protein-2 and -7 (rhBMP-2 and -7), in particular, enhance fracture healing in numerous experimental and clinical studies. Some limitations with use of recombinant proteins may be overcome by use of gene therapy. Gene therapy involves delivery of the growth factor gene to cells at the fracture site using a viral or non-viral vector. The gene is then expressed (protein synthesis) by cells at the fracture site. Delivery of the BMP gene to the fracture site using gene therapy has been evaluated in laboratory animal models of non-union, with favorable results and without complications. CONCLUSION: Delivery of growth factors, particularly members of BMP family, to the fracture site using gene therapy may be a method to enhance fracture healing. Use of this technology may improve the prognosis for patients with long-bone fractures. CLINICAL RELEVANCE: Clinical application of gene therapy could improve the prognosis for human and veterinary patients with long-bone fractures, but has not been evaluated clinically.     

共和盆地温性草原物候期草地生产力与气候因素的灰色关联度分析

利用灰色关联分析方法,对共和盆地温性草原草地生产力与气候因素的关联程度作相关分析,以牧草各物候期产量为对照数列,以牧草生长期月均温、月降水量及月日照时间为对比数列,经分析结果表明:牧草抽穗期产量与5月的降水量、温度和3-5月的日照时间关联度最大,而牧草籽粒成熟期产量与6-8月的温度和日照时间关联度最大。因此,在牧草早期生长阶段牧草产量取决于5月的降水量、温度和3-5月的日照时间,而在牧草成熟阶段牧草产量取决于6-8月的温度、日照时间,尤其是6-8月的温度是决定当年牧草产量高低的关键因素。     

松嫩草原盐碱土过氧化物酶活性及其与肥力因素的关系

2007年5-9月,对松嫩草原盐碱土过氧化物酶活性及肥力因素进行测定,为改良利用盐碱草地提供理论依据。结果表明:研究样地内过氧化物酶活性变化范围较大,8月份变异系数最高;随着植被盖度的增加,酶活性呈现逐渐降低的趋势;在植被生长季内酶活性5月较高,而在8月较低;过氧化物酶活性和全氮呈显著负相关;和速效磷、全盐、pH值有显著的正相关关系;和其他肥力因素相关性因月份而异。主成份分析结果表明可以用过氧化物酶活性作为盐碱土肥力变化的指示指标。