A unified framework for mapping quantitative trait loci in bivalent tetraploids using single-dose restriction fragments: a case study from alfalfa

The development of statistical methodologies for quantitative trait locus (QTL) mapping in polyploids is complicated by complex polysomic inheritance. In this article, we propose a statistical method for mapping QTL in tetraploids undergoing bivalent formation at meiosis by using single-dose restriction fragments. Our method is based on a unified framework, one that uses chromosome bivalent pairing configuration and gametic recombination to discern different mechanisms of gamete formation. Our bivalent polyploid model can not only provide a simultaneous estimation of the linkage and chromosome pairing configuration-a cytological parameter of evolutionary and systematic interest-but also enhances the precision of estimating QTL effects and position by correctly characterizing gene segregation during polyploid meiosis. By using our method and a linkage map constructed in a previous study, we successfully identify several QTL affecting winter hardiness in bivalent tetraploid alfalfa. Moreover, our results reveal significant preferential chromosome pairing at meiosis in an F1 hybrid population, which indicates the importance of reassessing the traditional view of random chromosome segregation in alfalfa.     

应用核酸分子杂交技术检测心肌炎组织中的肠道病毒RNA

用生物素标记ｐＣＢＩＩＩ／３５和ｐＣＢＩＩＩ／５１肠道病毒属特异性探针，对４５心肌炎和心肮病尸检或心肌活检心脏组织进行原位杂交，结果显示：１２例（２６．６％）存在肠道病毒ＲＮＡ。柯萨基Ｂ３病毒型特异性探针ｐＣＢＩＩＩ／２９进一步杂交表明，１２例经证实存在肠道病毒ＲＮＡ的心肌组织中５例（４１．７％）出现阳性杂交信号。阳性杂信号主要位于单个或多个心肌细胞的胞浆和心肌的间质组织，偶见竽心肌小血管内皮细胞     

溶脲脲原体感染对大鼠Sertoli细胞分泌 IL-6和TGF-β1的影响

目的 :研究大鼠Sertoli细胞在感染中的免疫调节作用。方法 :SD大鼠的睾丸经Ⅱ型胶原酶和透明质酸酶二步消化、过滤、离心获得高纯度、高活率的Sertoli细胞。体外培养的Sertoli细胞经溶脲脲原体 (UU)、UU上清和热灭活UU感染或作用 ,用ELISA法分析、观察UU感染时Sertoli细胞分泌IL 6和TGF β1 的变化。结果 :低剂量的活UU和UU上清能明显上调Ser toli细胞分泌IL 6的功能 (P <0 0 1) ,而高剂量时则表现为明显的抑制作用 (P <0 0 1) ;低、高剂量的活UU、UU上清和热灭活UU均能明显抑制Sertoli细胞分泌TGF β1 的功能 (P <0 0 1)。结论 :大鼠Sertoli细胞在睾丸局部感染时通过其分泌的IL 6和TGF β1 可发挥免疫调节作用。     

术苓健脾胶囊对TNBS诱导的大鼠实验性结肠炎的作用及机制

探讨术苓健脾胶囊（术苓）对2,4,6-三硝基苯磺酸（TNBS）诱导的大鼠实验性结肠炎的作用及其机制。采用2.5%TNBS灌肠制备大鼠实验性结肠炎模型。将大鼠随机分为正常组、模型组、肠炎宁（180 mg/kg）组以及术苓低剂量（40 mg/kg）、高剂量（120 mg/kg）组。造模后药物治疗7 d后处死大鼠。其间每日记录大鼠体重,观察大鼠疾病活动状态。实验结束后,取结肠组织进行HE病理学分析、检测结肠组织中髓过氧化物酶（MPO）酶活、诱导型一氧化氮合酶（iNOS）、炎性细胞因子（IL-6、IL-1β、IFN-γ、IL-10）及紧密连接蛋白（occludin、ZO-1）的表达水平,并检测血清中炎性细胞因子（IL-6、IL-1β）的含量。结果表明,与模型组相比,术苓给药显著缓解了TNBS造模引起的体重下降、疾病活动指数（DAI）升高,缓解了结肠组织的缩短、水肿以及病理学损伤,减少了炎性细胞浸润、隐窝的破坏与杯状细胞的丢失,降低了结肠组织MPO酶活性、iNOS与炎性细胞因子的水平,增加了结肠紧密连接蛋白的表达,同时降低了血清中的炎性因子的含量。结果表明,术苓通过降低炎性因子水平,增加肠道紧密...     

Scanning electron microscopic observations on larvae and young adults of Angiostrongylus cantonensis

Scanning electron microscopic observations on the structure of the body surface of various larval stages and young adults of Angiostrongylus cantonensis were made. The mouth opening of the first and second stage larvae closes in "Y" form until well developed young adult stage. There are two rows of 6 sensory papillae each around the mouth. With development of the worm, the papillae of the outer row gradually degenerated and could hardly be seen in adult worms. A pair of amphidial pores was present on the external side of lateral papillae of the inner row, being conspicuous in the fourth-stage larvae. There was one excretory pore on the ventral side of the anterior end. The copulatory bursa of the male worms began to develop in the third stage larvae and became well developed in the 25-day young adults. The processes of the development of copulatory bursa were described. The gonopore could be seen in the female worm as early as in the first-stage larvae but the anal pore appeared only in the fourth-stage larvae, both of them did not develop completely until the young adult stage of 11 day old (Figs. 1-18).     

魔芋精粉与几种常用膳食纤维降血脂效果比较及机理探讨

用含胆固醇1％、胆盐0.25％、猪油5％的高脂饲料喂饲健康雄性大鼠,诱发高脂血症的同时分别加入5％的魔芋精粉、果胶、褐藻胶及琼脂,观察此四种膳食纤维对大鼠生长、血清脂质含量、肝脏脂质含量及肝脏组织病理的不同影响,并通过测定粪中酸性固醇的排泄量来观察它们对胆汁酸代谢的影响。结果表明:1)四种膳食纤维均能有效地降低进食高脂膳食大鼠的空腹血清总胆固醇含量,对空腹血甘油三酯水平无影响;2)魔芋精粉能较其余三种膳食纤维更有效地降低肝脏组织脂质含量,包括胆固醇及甘油三酯。肝组织病理学检查亦显示魔芋精粉减轻肝脂变效果最佳;3)四种膳食纤维均能增加粪中胆汁酸尤其是鹅脱氧胆酸的排泄量,推测这可能是它们降低机体脂质的机理之一;4)四种膳食纤维在5％摄入水平对大鼠摄食及生长无不良影响。     

Nonlinear Binding of Valproic Acid (VPA) and E-Δ2-Valproic Acid to Rat Plasma Proteins

The binding characteristics of valproic acid (VPA) and its pharmacologically active monounsaturated metabolite, E-²-VPA, to rat plasma proteins were compared. The plasma free fraction was determined by a rapid equilibrium procedure, which minimizes the interfering effects of nonesterified fatty acids liberated by in vitro lipolysis. Nonlinear binding behavior was observed with both compounds over their respective pharmacologic concentration range. Multiple binding-site models were invoked to explain the binding isotherm. The 2-unsaturated compound has a much higher affinity for the rat plasma proteins (mainly albumin) than its saturated precursor. The equilibrium association constants for the high- and intermediate-affinity sites were more than an order of magnitude higher with E-²-VPA than with VPA (10⁴–10⁶ versus 10³ M ^–1). This difference in binding affinity was also reflected by a lower plasma free fraction for E-²-VPA compared with VPA (<<10 versus >20% at total concentrations of less than 100 µg/ml). A more pronounced dose- and concentration-dependent variation in the distribution and clearance kinetics is predicted for the 2-unsaturated analogue compared to VPA. Also, the structural dependency in plasma protein binding observed with these branched-chain fatty acids may provide insights into the mechanism of interaction between fatty acyl molecules and albumin.     

Dose-dependent emergence of preneoplastic foci in rat livers after exposure to 2-nitropropane

Male and female Sprague-Dawley rats, 4–6 days old were exposed for 3 weeks (6 h/day, 5 days/week) to 2-nitropropane vapours of 0, 25, 40, 50, 80 and 125 ppm. One week later polychlorinated biphenyls (Clophen A50, 10 mg/kg body weight) were administered for promotion twice a week for 8 weeks. Thirteen weeks after starting the experiments the logarithms of the numbers of preneoplastic liver foci deficient in adenosine-5-triphosphatase were found to be linearly related to the exposure concentrations of 2-nitropropane. Male rats exhibited an approximately four times lower foci incidence than females.     

Characterization of four newly established human colorectal adenocarcinoma cell lines from Chinese patients.

Four colon adenocarcinoma cell lines, CC-M2, CC-M3, CC-M4, and CC-M2NM, have been established from surgical specimens of 18 unselected patients without the use of "feeder" cells and additional growth factors (e.g., insulin, hydrocortisone, etc.) in the culture medium. The methods of primary cultivation of tissue explants are described. Studies of determination of morphology, growth curve, plating efficiency, chromosomal analysis, CEA and beta-HCG synthesis, and tumorigenicity, were done to characterize the cell lines. Significant variations have been found in one of the four cell lines, both in vitro and in vivo studies. There are distinct phenotypes in the established cell lines which may be useful in studying the cell differentiation and progression of colorectal cancer.