毛白杨树皮内含物对光肩星天牛抗性的探讨

毛白杨树皮内含物对光肩星天牛抗性的探讨王蕤，巨关升，秦锡祥（中国林业科学研究院林业研究所北京１０００９１）关键词杨树，抗性，酚酸，酚甙光启星天牛（ＡｎｏｐｌｏｐｈｏｒａｓｌａｂｒｉｐｅｎｎｉｓＭｏｔｓｈ．）对杨树危害严重，受害的树种多，涉及的地域广，...     

Ergot alkaloid transport across ruminant gastric tissues

Ergot alkaloids cause fescue toxicosis when livestock graze endophyte-infected tall fescue. It is generally accepted that ergovaline is the toxic component of endophyte-infected tall fescue, but there is no direct evidence to support this hypothesis. The objective of this study was to examine relative and potential transport of ergoline and ergopeptine alkaloids across isolated gastric tissues in vitro. Sheep ruminal and omasal tissues were surgically removed and placed in parabiotic chambers. Equimolar concentrations of lysergic acid, lysergol, ergonovine, ergotamine, and ergocryptine were added to a Kreb's Ringer phosphate (KRP) solution on the mucosal side of the tissue. Tissue was incubated in near-physiological conditions for 240 min. Samples were taken from KRP on the serosal side of the chambers at times 0, 30, 60, 120, 180, and 240 min and analyzed for ergot alkaloids by competitive ELISA. The serosal KRP remaining after incubation was freeze-dried and the alkaloid species quantified by HPLC. The area of ruminal and omasal tissues was measured and the potential transportable alkaloids calculated by multiplying the moles of transported alkaloids per square centimeter of each tissue type by the surface area of the tissue. Studies were conducted to compare alkaloid transport in reticular, ruminal, and omasal tissues and to determine whether transport was active or passive. Ruminal tissue had greater ergot alkaloid transport potential than omasal tissue (85 vs 60 mmol) because of a larger surface area. The ruminal posterior dorsal sac had the greatest potential for alkaloid transport, but the other ruminal tissues were not different from one another. Alkaloid transport was less among reticular tissues than among ruminal tissues. Transport of alkaloids seemed to be an active process. The alkaloids with greatest transport potential were lysergic acid and lysergol. Ergopeptine alkaloids tended to pass across omasal tissues in greater quantities than across ruminal tissues, but their transport was minimal compared to lysergic acid and lysergol.     

犬贾第虫dsRNA病毒的鉴定及特性

对分离到的6株犬贾第虫（Giardia cnais)包囊进行核酸分析，在其中1株犬贾第虫核酸的琼脂糖凝胶电泳图谱上观察到1条长度约7.0kb的片段。经鉴定，该核酸不能被DNA酶（100mg/L）降解，对质量浓度低的RNA酶（0.1mg/L)不敏感，但可被质量浓度高的RNA酶（10mg/L）降解。纯化包囊经流氮冻融后，磷钨酸负染，电镜观察发现有球形、直径约为33nm的病毒样粒子存在，包囊超薄切片在胞质中也观察到该病毒样粒子存在。RNA依赖RNA聚合酶活性测定结果表明，该病毒具有RNA依赖RNA聚合酶的活性。犬贾第虫dsRNA病毒核经RT-PCR扩增后得到1条预计扩增大小的片段，将其回收后连接到pMD18-T载体上进行克隆并测序，所得序列仅与蓝氏贾第虫病毒具有较高同源性。     

新疆莎车县棉田自然天敌数量动态

2002-2004年研究了新疆莎车县棉田节肢动物类自然天敌种群动态及棉花品种的影响。结果发现节肢动物类自然天敌67种,数量较多的共10类,即瓢虫类、蝽类、隐翅虫类、蓟马类、草蛉类、食蚜双翅目、胡蜂类、蚜茧蜂类、蜘蛛类和捕食螨类。其中瓢虫类、蝽类和蜘蛛类占天敌个体总数85%~93%。3年中这三类天敌各自所占比例,瓢虫为4%~65%,食虫蝽为19%~57%,蜘蛛为6%~34%。瓢虫、食虫蝽和蜘蛛的最高密度2002年分别为237.2、164.0、87.0头/百株,2003年分别为28.3、533.3、232.0头/百株,2004分别为1506.5、237.0、55.3头/百株。对转基因抗虫棉GK19(表达Cry1A杀虫蛋白)、SGK321(表达Cry1A CpTI杀虫蛋白)和普通棉花泗棉3号、石远321的研究表明,各种天敌在不同品种上的种群数量没有显著性差异,而喷施化学农药可以造成天敌数量明显减少。     

不同地域长爪沙鼠群体间遗传状况分析

应用27个生化基因位点,分别对首都医科大学实验动物科学部和浙江省实验动物中心饲育的2个长爪沙鼠群体进行了遗传分析。结果显示,首都医科大学实验动物科学部长爪沙鼠群体遗传适应性、遗传多样性水平、遗传变异程度都明显高于浙江省实验动物中心沙鼠群体（P〈0.05）,并且这2个沙鼠群体间未出现较为明显的遗传分化（FST〉0.05）。     

抗菌肽的研究与应用

抗菌肽具有分子量小、热稳定性好、无免疫原性、抗菌谱广等特点；并且，抗菌肽对畜禽具有促生长、保健和治疗疾病等功效；具有无毒副作用、无残留、无致细菌的耐药性等特性；在动物养殖和提高畜产品品质方面，抗菌肽也具有重要的潜在应用价值。文章结合当今抗菌肽的研究现状和发展前景，对抗菌肽的分类、抗菌机理、应用状况等进行了综述。     

Estradiol stimulated proliferation and differentiation of prostatic stromal cells through regulation of BPH-1 paracrine

AIM: To characterize the effect of estradiol on proliferation, differentiation and extracellular matrix (ECM) accumulation in stromal cells through regulation of BPH-1 paracrine. METHODS: BPH-1 cells were stimulated with different concentrations of estradiol. Conditioned media (CM) were harvested and their effects on stromal cell cultures were tested. Cell proliferation was determined by MTT assay. mRNA of smoothelin, fibronectin, collagen Ⅳ and transforming growth factor β₁(TGF-β₁) were analyzed by real-time RT-PCR. Western blotting was used to determine smooth muscle myosin heavy chain (SMMHC). ELISA and radioimmunoassay were respectively used to measure fibronectin, TGF-β₁ and collagen Ⅳ protein expressions.RESULTS: Estrodiol stimulated the expression and secretion of TGF-β₁ in BPH-1 cells. The proliferation of stromal cells increased when they were cultured with CM harvested from estrogen treated BPH-1 cells. The mRNA levels of collagen Ⅳ and smoothelin increased in stromal cells treated with CM from BPH-1 cells. The results of radioimmunoassay also showed that the collagen Ⅳ protein level up-regulated in the supernatants and cell extracts of CM-treated stromal cells. A neutralizing antibody to TGF-β₁ inhibited the stimulation of collagen Ⅳ and SMMHC by BPH-1 CM. The expression of fibronectin was only marginally changed in stromal cells cultured in the presence of BPH-1 CM. CONCLUSION: The BPH-1 cells increase ECM accumulation and differentiation of stromal cells through TGF-β₁. Estradiol stimulate differentiation of stromal cells by induction of TGF-β₁ expression. Estradiol stimulate proliferation by influencing the factors secreted from prostatic epithelial cells.