Trophoblastic interferon-gamma: current knowledge and possible role(s) in early pig pregnancy     

Cencic A  La Bonnardière C 《Veterinary research》2002,33(2):139-157

In the pig as in ruminant species, the implantation of the elongated conceptus - the embryo with its associated membranes - onto the maternal uterus is accompanied by an intense secretion of interferon (IFN), which culminates at day 15 of development. It has been shown that in fact the pig trophectoderm - the polarized epithelium which lines the conceptus - simultaneously secretes two types of interferons: IFN-gamma (IFN-gamma), which is the more abundant species, is produced in very substantial amounts. Another IFN is also secreted, which happens to be a novel type I IFN, now named IFN-delta. It was previously shown that the uterus is the most probable target of the pig trophoblastic IFNs, since no autocrine effect was found on the trophoblast. It has also been shown that, unlike for the ruminant species, the pig trophoblastic IFNs do not play an apparent role in the so-called maternal recognition of pregnancy. We have focused this review on IFN-gamma, because first, it is the major species secreted and secondly, IFN-gamma has various regulatory effects on different tissues, including lymphoid cells. We particularly address the question of the possible role of trophoblastic IFN-gamma in early pregnancy, in the light of the known biological functions of human and mouse IFN-gamma.  相似文献   

Simultaneous serological evidence of Actinobacillus pleuropneumoniae, PRRS, Aujeszky's disease and influenza viruses in Spanish finishing pigs     

Gutiérrez-Martín CB  Rodríguez-Delgado O  Alvarez-Nistal D  De La Puente-Redondo VA  García-Rioja F  Martín-Vicente J  Rodríguez Ferri EF 《Research in veterinary science》2000,68(1):9-13

A total of 198 pigs with tachypnoea and temperature >/= 40 degrees C were selected on a Spanish finishing unit, and their sera were examined for antibodies to Actinobacillus pleuropneumoniae (App), porcine reproductive and respiratory syndrome virus (PRRSV), Aujeszky' disease virus (ADV), and swine influenza virus (SIV). Eighty-nine point nine per cent of the pigs were seropositive to App, 88.6 per cent to PRRS, 73.0 per cent to ADV, and 30.6 per cent to SIV. Thirty-one pigs (15.6 per cent) were seropositive for App, PRRSV, ADV and SIV, and only one (0.5 per cent) was seronegative for all. Statistical association was assessed for dual infections but it was not found in any case (P > 0.05). Other parameters (dyspnoea, nasal discharge and coughing) were also recorded, and no significant associations between them and the presence of antibodies against any of the four infections was found.  相似文献   

In vitro susceptibility of Escherichia coli strains isolated from diarrhoeic dairy calves to 15 antimicrobial agents     

Orden JA  Ruiz-Santa-Quiteria JA  García S  Cid D  De La Fuente R 《Journal of veterinary medicine. B, Infectious diseases and veterinary public health》2000,47(5):329-335

The in vitro activities of 15 antimicrobial agents against 195 strains of Escherichia coli isolated from dairy calves affected by neonatal diarrhoea were determined. Of these strains 137 produced one or more potential virulence factors (F5, F41, F17, cytotoxic necrotizing factor, verotoxin and the eae gene), but the remaining 58 strains did not produce any of these factors. The overall percentage of resistant strains to streptomycin, tylosin and tetracycline was very high (above 65%). A high level of resistance (from 23 to 50%) to ampicillin, neomycin, kanamycin, spectinomycin, chloramphenicol, sulphadimethoxine and trimethoprim was also detected. The E. coli strains were very susceptible (89-95%) to apramycin and gentamicin and highly susceptible (99-100%) to polymyxin B, florfenicol and nitrofurazone. Some significant differences (P < 0.05) in the frequencies of resistance to some of the antimicrobials tested and in the rates of multi-drug resistance among the strains producing potential virulence factors and non-fimbriated, non-toxigenic, eae-negative strains were found. Most of the strains showed multi-resistance: 76.9% of the isolates were resistant to at least two antibiotics, 67.7% were resistant to at least four antibiotics and 50.3% were resistant to at least six antibiotics.  相似文献   

Biodegradability of dextrans in soils     

M. Pagliai  G. Guidi  M. La Marca 《植物养料与土壤学杂志》1979,142(1):95-97

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The historical evolution of the Ångström formula and its modifications: Review and bibliography     

J.A Martínez-Lozano  F Tena  J.E Onrubia  J De La Rubia 《Agricultural and Forest Meteorology》1984,33(2-3)

A bibliographical review has been made in order to study the expressions proposed by different investigators correlating relative solar radiation (Q/Q_o) with relative sunshine (n/N). The most frequent form for such a correlation is that proposed by Ångström in 1924: Q/Q_c = α + (1 − α) (n/N), with the modification introduced by Prescott in 1940: Q/Q_o = a + b(n/N). About 120 different papers giving values for the coefficients a and b have been studied and the results presented in a tabulated form. The consideration of such values makes it possible to observe the large variability of these two coefficients. Some of the factors influencing this variability are discussed. Some authors also proposed different modifications to the so-called Ångström—Prescott formula in order to get more reliable results, and the most interesting of these modifications have been reviewed.  相似文献   

甘肃草地蜘蛛区系名录   总被引：2，自引：1，他引：1  

冯光翰  喇有仁 《甘肃农业大学学报》1993,28(4):407-412

蜘蛛是草地害虫的重要捕食性天敌”本文记叙甘肃天然草原和人工载培草地的蜘蛛20科63属120种,供蜘蛛研究、草地天敌的保护利用和害虫的防治参考。  相似文献   

Leonotis nepetaefolia: An important plant virus reservoir in central Mexico     

Elías Piedra-Ibarra  Rodolfo De La Torre-Almaráz  Gerardo Zúñiga  Beatriz Xoconostle-Cázares  Roberto Ruíz-Medrano 《Phytoparasitica》2005,33(5):480-494

The presence of viruses in the weedLeonotis nepetaefolia in central México is reported from two field surveys.L. nepetaefolia, with viral-like symptoms such as mosaic, leaf deformation and calico, was observed growing next to cultivated fields in the Valley of Atlixco, Puebla, an important agricultural region in Mexico. The viruses harbored by this plant were characterized biologically, serologically and by molecular methods. The viruses detected wereAlfalfa mosaic virus (AMV),Cucumber mosaic virus (CMV), a satellite RNA of CMV (CMV satRNA) andTobacco mosaic virus (TMV). This last one was detected only during the first survey. CMV was the predominant virus found in both surveys, and was associated mostly to mosaic symptom. Phylogenetic analysis based on the coat protein gene sequence of CMV indicated that this isolate belongs to subgroup IA and confirmed that it is a mosaic-inducing isolate, whereas AMV belongs to subgroup II. Finally, CMV satRNA was found to be a non-necrogenic ameliorative variant, both by symptomatology and by phylogenetic analysis. Our results suggest thatL. nepetaefolia is a reservoir for several viruses in central Mexico, and given its wide distribution in several parts of the world, its role as a virus reservoir could be more general. http://www.phytoparasitica.org posting Aug. 31, 2005.  相似文献   

浑善达克沙地景观格局变化研究   总被引：8，自引：5，他引：8  

王牧兰  包玉海  阿拉腾图雅  秦树晖 《干旱区资源与环境》2007,21(5):121-125

在遥感和GIS技术的支持下,通过采用转换矩阵和斑块伸长指数、破碎度指数、多样性指数、优势度指数、均匀度指数等景观指数分析了80年代末期到2000年浑善达克沙地景观动态变化,结果显示:①景观要素类型尺度上,研究区草原景观和固定沙丘景观面积明显缩小,半固定沙丘景观和流动沙地景观向外扩展,反映出整个沙地向荒漠化方向发展的趋势;②景观尺度上,斑块伸长指数有所下降,破碎度变大,反映出人类活动对景观的干预作用不断增强;景观多样性指数和均匀度指数减小,优势度指数增加,表明景观的组成趋向简单,主要景观对区域景观变化起到主导作用,景观中的支配能力和影响力在增强。  相似文献   

阿拉善戈壁双峰驼的微卫星多态性与体尺性状关联分析     

乌仁套迪  白俊艳  巴拉  周俊文  张文彬 《中国畜牧兽医》2018,45(7):1881-1890

本研究旨在利用微卫星标记分析阿拉善戈壁双峰驼的遗传多样性,寻找与其体尺性状相关联的微卫星标记,为阿拉善戈壁双峰驼的标记辅助选择提供参考。试验利用非变性聚丙烯酰胺凝胶电泳技术,检测17个微卫星标记在阿拉善戈壁双峰驼群体中的多态性,并与其体尺性状进行相关性分析。结果显示,17个微卫星标记共检测到60个等位基因,平均有效等位基因数为2.7302,平均杂合度为0.6205,平均多态信息含量为0.5308,可见阿拉善戈壁双峰驼群体的遗传多样比较丰富。微卫星标记多态性与阿拉善戈壁双峰驼体尺性状的关联分析发现,有8个微卫星标记（LCA82、LCA90、CMS15、CMS36、CMS104、CVRL01、YWLL36和YWLL44）与不同体尺性状有一定的关联性,尤其是CMS36和YWLL44与所测体尺性状均有关联,其中CMS36不同基因型的体长和体重均有显著差异（P<0.05）,具体表现为BB > AA > AB,AA和BB基因型的体高、胸围、管围均显著高于AB基因型（P<0.05）;YWLL44的AC基因型体高、胸围和体重均显著高于BD基因型（P<0.05）,AC基因型的体长显著高于AB和BD基因型（P<0.05）,AB和AC基因型的管围显著高于BD基因型（P<0.05）。研究表明,8个微卫星标记对阿拉善戈壁双峰驼体长有一定影响,CMS36和YWLL44对其体高有影响,LCA82、LCA90、CMS36、CVRL01、YWLL36和YWLL44对其胸围有影响,LCA82、CMS15、CMS36、CMS104、CVRL01和YWLL44对其管围有影响,LCA82、LCA90、CMS15、CMS36、CVRL01和YWLL44对其体重有影响。  相似文献   

Three -Dimensional Numerical Analysis of Optimum Design of the Indoor Ventilation     

YANG Yu - rong  LONG Tian - yu  LIU La - mei 《保鲜与加工》2006,(3):78

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