慢性低氧时牦牛和迁饲黄牛颈动脉体组织形态的比较

目的对牦牛、迁饲黄牛及低海拔黄牛颈动脉体(CB)形态及CB中低氧相关因子的表达进行比较,探讨高原土生或迁饲动物CB适应慢性低氧的模式。方法采集青海地区海拔3000~4000m的9头牦牛、2500m的9头高山迁饲黄牛及甘肃平原海拔1300米的12头低海拔黄牛的CB,固定、切片、染色后行光学显微镜和电子显微镜比较观察,并对CB中低氧诱导因子-1α(HIF-1α)、一氧化氮合酶(NOS)、瘦素受体(LEPR)、促红细胞生成素(EPO)等低氧相关因子的表达进行免疫组织化学观察。结果相比黄牛,牦牛CB体积较小,不同海拔牦牛的CB大小、形态及主细胞数量差异无显著性,而迁饲黄牛CB体积较低海拔黄牛大。牦牛CB主细胞中明细胞、暗细胞和固缩细胞的数量百分比比例为67.1%∶28.2%∶4.7%,迁饲黄牛为78.5%∶18.6%∶2.9%,低海拔黄牛为87.3%∶10.2%∶2.5%;与低海拔黄牛相似,牦牛CB少部分明细胞胞质透亮,暗细胞胞核染色质较致密并呈粗颗粒状,而迁饲黄牛CB大部分明细胞胞质透亮,暗细胞胞核染色质致密,颗粒稀少。3种牛支持细胞形态差异无显著性。与低海拔黄牛相比,迁饲黄牛CB主细胞的少数核异染色质增多,个别形态异常,胞质内多数细胞器肿胀溶解,残留少量细胞器和致密核心囊泡。3种牛CB中均有不同程度的HIF-1a、NOS、LEPR、EPO的蛋白表达,其中牦牛CB中EPO蛋白表达阳性率较低海拔黄牛明显降低(P0.05)。结论海拔高度不是影响牦牛颈动脉体大小和主细胞数量的主要因素。迁饲黄牛CB主细胞中细胞类型的比例与牦牛有趋同性改变,但缺氧时行使功能的I型细胞功能系统受损,尚处于低氧环境下的习服阶段。慢性低氧可能主要影响牦牛和迁饲黄牛CB中EPO蛋白表达。     

门静脉高压症猪肺血管的结构重建及临床意义

目的:探讨门静脉高压症猪肺血管形态结构重建的特点。方法:采用健康2月龄湖北白猪14头,随机分为正常对照组和实验组,用四氯化碳建立门静脉高压症模型。取肺动脉和肺静脉,横断切片。用Pilloridine和Cy3-IgG分别染胶原纤维和平滑肌,弹性纤维自发荧光。在激光共聚焦显微镜下观察,用计算机图像分析系统测量各结构成分的相对含量。结果:与正常对照组相比,门静脉高压猪肺血管壁中胶原纤维、平滑肌的相对含量及胶原纤维与弹性纤维的比值(C/E)均增大,弹性纤维则减少。结论:门静脉高压时,猪肺血管的形态结构可发生重建,表现为胶原纤维增加,弹性纤维减少,导致C/E值的改变。肝肺联合移植时,移植材料间的结构成分的差异也应引起关注。     

高原肺水肿患者血流动力学变化及对吸氧反应的测定

目的:探讨高原肺水肿的发病机理。方法:采用右心漂浮导管检测法, 对9例高原肺水肿患者及9例同海拔高原健康人的血流动力学指标进行了检测, 同时也观察了吸入纯氧对高原肺水肿患者血流动力学的影响。结果:高原肺水肿患者发病时, 肺动脉平均压、肺血管阻力、心脏指数均明显高于同海拔高度健康人, 而患者肺动脉楔压, 右心房压力同对照组相比, 未见显著差异;吸氧后, 高原肺水肿患者心率、肺动脉平均压力, 肺血管阻力及心脏指数均较吸氧前明显下降, 特别是肺动脉平均压及肺血管阻力下降尤为明显, 肺动脉平均压力在吸氧1min后即明显下降, 吸氧5min后, 下降至最低值, 但吸氧20min后仍未达对照组水平。结论:高原肺水肿是非心源性肺水肿, 肺动脉高压在其发病中起重要作用。     

血红素氧合酶1基因表达与慢性低氧高二氧化碳性肺动脉高压的关系

 目的：研究一氧化碳体系对低氧高二氧化碳性肺动脉高压的调控作用。方法：将SD大鼠分为正常对照组(A组),4周低O₂高CO₂组(B组),4周低O₂高CO₂+血晶素组(C组)。采用透射电镜、图像分析、免疫组化、组织原位杂交技术等方法,观察各组大鼠肺动脉平均压(mPAP)、颈动脉平均压(mCAP)、右心室/(左心室+室间隔)重量比、肺细小动脉显微和超微结构、血CO浓度及肺细小动脉HO-1及其基因表达的变化。结果：①B组mPAP、RV/(LV+S)显著高于A组(P<0.01),C组mPAP、RV/(LV+S)明显低于B组(P<0.01),3组间mCAP比较差异无显著性(P>0.05)。②全血CO浓度B组明显高于A组(P<0.01),C组明显高于B组(P<0.01)。③光镜下肺细小动脉管壁面积/管总面积(WT/TA)、肺细小动脉中膜平滑肌细胞核密度(SMC)、肺细小动脉中膜厚度(PAMT)B组显著高于A组(P<0.01),C组明显低于B组(P<0.01)。④电镜下B组肺细小动脉中膜平滑肌细胞增生,面积增大,染色质增多,外膜胶原纤维密集,C组大鼠肺细小动脉中膜平滑肌细胞和外膜胶原纤维增生明显轻于B组。⑤免疫组化、原位杂交发现B组I级(直径＞200μm)、Ⅱ级(直径50-200μm)、Ⅲ级(直径<50 μm)肺细小动脉HO-1及HO-1mRNA平均吸光度值显著高于A组(P均<0.01),C组各级肺细小动脉HO-1及HO-1 mRNA平均吸光度值明显高于B组(P均<0.01)。结论：一氧化碳体系表达增强可抑制慢性低氧高二氧化碳性肺动脉高压的形成和肺血管结构重建,提高一氧化碳体系表达可能是防治COPD、肺动脉高压的新途径。     

缺氧性肺动脉高压大鼠肺巨噬细胞肾上腺髓质素蛋白表达及其意义

目的探讨缺氧性肺动脉高压 (HPH)肺巨噬细胞 (MΦ)肾上腺髓质素 (adrenomedullin,AM)合成、分泌及其在HPH病理生理过程中的作用。方法本研究模拟海拔5km高原连续缺氧 ,制备大鼠HPH动物模型 ,应用光镜、免疫组化、放免测定、细胞计数等方法 ,观察、测定缺氧后10、20、30d和平原对照组 (对照组 )大鼠肺MΦ(肺血管MΦ、间质MΦ、支气管壁MΦ、肺泡MΦ)AM蛋白表达及血浆、支气管肺泡灌洗液(BALF)AM含量变化。结果对照组及缺氧各组肺MΦ、血管内皮细胞、血管和支气管平滑肌细胞、支气管黏膜上皮、Ⅱ型肺泡上皮AM均呈阳性表达。其中各部位MΦ在缺氧后数量明显增加 ,与对照组比较差异显著 (P<0.05) ,AM表达明显增强。缺氧后10、20、30d血浆AM含量显著高于对照组 (P<0.01)。BALF含量于缺氧后10、20d显著高于对照组 (P<0.01) ,30d含量下降 ,与对照组比较无显著差异 ,但P值近于0.05。结论肺MΦ不仅是具有肺部免疫和清除尘埃的功能 ,还可以产生多种生物活性物质 ,参与机体调节的多能细胞。缺氧后肺MΦ数量增加 ,AM表达增强 ,即AM合成分泌增加 ,使肺组织各部位AM含量增加 ,同时泌入血浆和BALF的浓度升高 ,从而对肺循环、肺通气、气道免疫反应及血管结构改建等多方面发挥广泛的调节作用     

高原鼠兔与大鼠低氧后外周血及骨髓红系细胞变化特点

文题释义： 红细胞系：循环中大量的红细胞构成了一个运输氧的器官，红系祖细胞和成熟红细胞共同组成了此器官，称为红细胞系。 红细胞系来源：红细胞系细胞来自未分化的多能干细胞，随着定向分化，红系祖细胞经历数个复制阶段，逐渐成熟并功能更加特化。在成人阶段，除非在低氧等病理情况下或收到环境损害干扰，循环中的红细胞总数保持稳定状态。 背景：生活于高原鼠兔的血液系统中外周血红细胞及骨髓有核红细胞数目及形态的变化，对其低氧适应有重要意义。 目的：通过对比高原鼠兔与大鼠在低氧前后外周血及骨髓红系细胞的变化，初步探讨高原鼠兔红系造血系统低氧适应的形态学变化。 方法：健康野生高原鼠兔及清洁级SD大鼠各12只，分别随机分为实验组和对照组，每组6只，实验组动物饲养在模拟海拔5 000 m高原低压低氧舱内，连续低压低氧干预28 d，对照组动物在海拔2 260 m的实验室内饲养。 结果与结论：①对照组高原鼠兔较对照组大鼠红细胞直径小而计数多，低氧暴露28 d后，两组实验动物红细胞数、血红蛋白浓度及红细胞压积均升高(P < 0.05)，但高原鼠兔增高幅度明显低于大鼠，且高原鼠兔平均红细胞体积、平均红细胞血红蛋白含量及平均红细胞血红蛋白浓度无明显变化；②骨髓涂片结果显示，低氧暴露后高原鼠兔中、晚幼红细胞比例无明显变化，但大鼠中、晚幼红细胞比例显著增加(P < 0.05)；③胸骨苏木精-伊红染色结果显示，低氧暴露后高原鼠兔幼红细胞岛无明显变化，但大鼠幼红细胞岛明显增生；④结果显示，高原鼠兔在低氧暴露前后外周血及骨髓红系变化幅度明显低于SD大鼠，考虑高原鼠兔长期生活在高原低氧环境下，可能与其低氧适应机制有关。 ORCID: 0000-0001-5253-8732(马婕) 中国组织工程研究杂志出版内容重点：干细胞；骨髓干细胞；造血干细胞；脂肪干细胞；肿瘤干细胞；胚胎干细胞；脐带脐血干细胞；干细胞诱导；干细胞分化；组织工程     

牛磺酸抗缺氧及防治肺动脉高压的研究及其细胞机制初探

目的通过动物模型观察牛磺酸对缺氧性肺动脉高压的治疗作用,同时观察其对体外培养牛肺动脉平滑肌细胞(PASMC)和内皮细胞(PAEC)增殖的影响。方法采用模拟高原5 000 m制作缺氧大鼠模型,缺氧2周。设平原(C组)及缺氧对照组(H组),观察牛磺酸治疗后(T组)的肺动脉压(mPAP)、血浆乳酸脱氢酶(LDH)活性、脂质过氧化产物丙二醛(MDA)、肺匀浆一氧化氮(NO)含量、右心室肥大指数的变化。体外培养PASMC和PAEC用3H-TdR掺入法比较牛磺酸对缺氧PASMC和PAEC增殖的影响。结果H组大鼠LDH活性升高为C的10.1倍(P<0.01);肺匀浆NO含量降低为C组的32%(P<0.01);血浆MDA含量显著升高为C组的1.64倍(P<0.01);mPAP显著增高,约为C组的2.74倍(P<0.01);右心室肥大指数是C组的1.56倍(P<0.01)。T组与H组相比较:LDH活性、血浆MDA、右心室肥大指数均显著降低(P<0.01);mPAP显著降低(P<0.05)。高浓度(10～20 mmol/L)的牛磺酸抑制缺氧内皮及平滑肌细胞的3H-TdR掺入,而低浓度的牛磺酸促进缺氧时PAEC的3H-TdR掺入(P<0.05),抑制缺氧时PASMC的3H-TdR掺入(P<0.05)。结论牛磺酸有抗缺氧及防治肺动脉高压的作用。缺氧抑制内皮细胞的增殖而促进平滑肌细胞的增殖,适当剂量的牛磺酸可以对抗缺氧对PAEC和PASMs的作用:减弱缺氧对PAEC的增殖抑制作用,抑制缺氧的促PASMC增殖作用,使之接近常氧水平。这可能是牛磺酸防治肺动脉高压的细胞机制。提示牛横酸对于高山病缺氧性肺血管收缩和血管结构改建的预防和治疗,可能具有广阔的应用前景。     

慢性低压低氧对大鼠肺组织HIF-1ɑ、COX1蛋白及氧化应激反应的影响

目的探讨慢性低压低氧环境对大鼠肺组织细胞色素C氧化酶1(COX1)蛋白及氧化应激反应的影响。方法将大鼠随机分为常氧组(1 500 m)和低氧组(4 300 m),低氧组大鼠暴露低氧30 d后采集标本。用Western blot检测肺组织COX1蛋白的表达及ELISA检测肺组织和血清HIF-1ɑ、血浆ROS、肺组织SOD和CAT酶。用生理信号采集系统测定肺动脉压(PAP)。结果在低氧组的大鼠血清和肺组织内HIF-1α蛋白显著高于常氧组(P0.01);ROS含量显著低于常氧组(P0.01);COX1蛋白在低氧组的大鼠肺组织中表达显著下降(P0.01);血清总抗氧化能力升高(P0.01)。结论高海拔对机体的影响可能是直接性的损伤,而并非仅仅是氧化应激反应所致。     

肺黏膜相关淋巴组织边缘区B细胞淋巴瘤及良性淋巴组织增生性疾病的临床病理分析

目的 研究肺原发性黏膜相关淋巴组织边缘区B细胞(MALT)淋巴瘤及良性淋巴组织增生性疾病的临床病理形态、免疫组织化学表型和B细胞重链基因重排,比较肺MALT淋巴瘤和良性淋巴组织增生性疾病的差异.方法 回顾性的分析原发性肺MALT淋巴瘤13例,7例肺良性淋巴组织增生性疾病资料.对标本行常规HE染色,EnVision免疫组织化学染色(抗体包括AE1/AE3、CD20、CD79α、CD3、CD5、CD10、CD21、bel-2、bcl-6、cyclinD-1)及免疫球蛋白重链IgH基因重排检测.结果 13例肺MALT淋巴瘤,细胞成分多样,分别由不同比例的小淋巴细胞样细胞、中心细胞样细胞、单核样B细胞组成,常伴有浆细胞分化.肿瘤细胞以弥漫性和滤泡边缘区排列为主,常见反应性淋巴滤泡和滤泡中心的植入.肿瘤细胞呈串珠状直接侵犯肺泡间隔和沿支气管血管束向周边及肺膜扩散.MALT淋巴瘤中,均未见坏死.9例可见肿瘤细胞侵犯血管壁,6例可见胸膜累及,2例肺门淋巴结侵犯.9例肺MALT淋巴瘤可见淋巴上皮样病变,免疫组织化学显示上皮细胞内的淋巴细胞CD20阳性,CD3阴性.7例肺良性淋巴组织增生性疾病,2例可见淋巴上皮样病变,免疫组织化学显示,其淋巴上皮样病变内的淋巴细胞,部分CD20阳性,部分CD3阳性.9例肺MALT淋巴瘤进行了免疫球蛋白重链IgH基因重排,8例阳性;7例良性淋巴组织增生性疾病均为阴性.结论 肺MALT淋巴瘤在细胞组成和排列上与其他部位结外MALT淋巴瘤相同,肿瘤细胞呈串珠状直接侵犯肺泡间隔和沿支气管血管束向周边及肺膜扩散.在肺内淋巴上皮样病变常见于MALT淋巴瘤,并有助于诊断,但并非其特异性病变,一些肺的反应性淋巴组织增生也可出现,用免疫组织化学有助于区别两种病变.免疫球蛋白重链IgH基因重排可以帮助鉴别肺MALT淋巴瘤和良性淋巴组织增生性疾病.     

牦牛犊牛睾丸结构特征及细胞外基质相关蛋白的分布

目的观察9头健康牦牛犊牛睾丸结构特征及细胞外基质相关蛋白的分布特点。方法采用组织化学染色和透射电镜技术,观察睾丸显微及超微结构特点,免疫组织化学SP法及IPP图像分析技术,研究层黏连蛋白(LN)、Ⅳ型胶原(ColⅣ)和硫酸乙酰肝素糖蛋白(HSPG)的分布特征。结果睾丸生精上皮由Sertoli细胞和生殖母细胞构成1~2层,未形成空腔。电镜下,Sertoli细胞异染色质丰富,相邻Sertoli细胞胞膜下分布有典型外质特化与肌动蛋白丝形成的胞膜下纤维束;生殖母细胞较大,胞质丰富。免疫组织化学显示,LN、ColⅣ和HSPG在生精小管基膜和肌样细胞表达较弱,LN在生殖母细胞内的表达量显著低于ColⅣ和HSPG(P0.05),而在Sertoli细胞及Leydig细胞均无表达;ColⅣ和HSPG在Sertoli细胞均为强阳性表达;HSPG在Leydig细胞的表达量显著高于ColⅣ(P0.05)。结论牦牛犊牛生精上皮以幼稚型Sertoli细胞为主,Leydig细胞处于胚胎型向成熟型过渡时期;细胞外基质(ECM)相关Ⅰ及Ⅳ型Col、LN及HSPG的分布适应于其在高原低氧环境中的发育。     

Renal lipofuscinosis in Danish slaughter cattle

A study was performed to characterize dark brown or black discoloured kidneys ("black kidneys") in Danish slaughter cattle and to investigate the aetiology and pathogenesis. In 133 939 cattle entering four abattoirs, 359 cases of "black kidneys" were recorded. Of these, 57 cases were submitted for macroscopical, microscopical, and ultrastructural examination. A pigment with characteristics similar to those of lipofuscin was found in secondary lysosomes in epithelial cells of the proximal tubules. Pigment accumulation was the cause of discoloration, with a positive correlation between the discoloration of the renal cortex and the degree of pigment accumulation. Cases occurred only in cattle of the Holstein breed or the Red Danish Dairy breed and mainly in animals aged 3 years or older. In these breeds, prevalences of 0.44% and 2.51% were found, respectively. Epidemiological analyses indicated that affected animals aged 4.5 to 6.5 years or 7.5 to 8.5 years were culled more frequently than unaffected cattle. Epidemiological and genealogical analyses strongly indicated a genetic aetiology with simple autosomal recessive inheritance.     

Chromosomal evolution in bovids: a comparison of cattle,sheep and goat G- and R-banded chromosomes and cytogenetic divergences among cattle,goat and river buffalo sex chromosomes

A G- and R-banding comparison of cattle (Bos taurus, 2n=60), goat (Capra hircus, 2n=60) and sheep (Ovis aries, 2n=54) chromosomes at the 450 band level was made. The study revealed a large number of banding homologies among the autosomes of the three species and resolved some ambiguities in arranging some of their small disputed acrocentrics by direct and indirect comparisons with some bovid marker chromosomes. A loss of the subcentromeric G-positive band in sheep chromosome 2q was observed when the G-banding patterns of sheep 2q and homologous cattle and goat chromosome 2 were compared. The chromosomal divergences among cattle, goat and river buffalo (Bubalus bubalis, 2n=50) sex chromosomes are shown to have occurred by pericentric and paracentric inversions with a loss (or acquisition) of constitutive heterochromatin.     

G- and R-banded prometaphase karyotypes in cattle (Bos taurus L.)

G- and R banded cattle (Bos taurus L.) karyotypes at about 500 band level are reported and discussed in light of chromosome banding standard nomenclature discrepancies. GTG-, GBG-, RBA- and RBG-banded karyotypes were arranged according to the Reading Conference standard. The G- and R-banding patterns of small acrocentric and disputed chromosomes (25, 27, 28 and 29) are demonstrated using some bovid marker chromosomes. G- and R-banded ideogrammatic representations using only one common banding nomenclature were also performed. This study is a contribution to the construction of new and clearer standard G- and R-banded karyotypes for this important species.accepted for publication by H. C. Macgregor     

Cytogenetic comparison between Vietnamese sika deer and cattle: R-banded karyotypes and FISH mapping

R-banded chromosomes of Vietnamese sika (VS) deer (Cervus nippon pseudaxis, 2N = 66), a threatened subspecies of sika deer endemic to Vietnam, are presented for the first time and were compared with bovine R-banded chromosomes to define a standard karyotype. Nineteen VS deer autosomes (CNP) were identified on the basis of the banding pattern relative to bovine chromosomes (BTA), while hypotheses for the remaining thirteen were proposed from comparisons with the published deer genetic map, BTA 1, 2, 5, 6, 8 and 9 each equivalent to two separate acrocentric CNP chromosomes and BTA 26 and 28 associated in a tandem fusion. To confirm these hypotheses, probes for the twenty-nine Texas nomenclature type I markers specific for each cattle autosome, sixteen other type I and fourteen microsatellite markers were used in FISH experiments on VS deer chromosomes. CNP7 presented the most complex rearrangement as compared with cattle chromosomes. A complete correspondence between VS deer and cattle chromosomes was established and it was extended with a comparison with the human karyotype to transfer human map information to this species of scientific and economic interest. Moreover, this work anchors the deer genetic linkage map to chromosome-specific markers. This revised version was published online in July 2006 with corrections to the Cover Date.     

Concentration of lead in mineral salt mixtures used as supplements in cattle food

We measured lead concentrations in samples of mineral salt mixtures used in cattle feed in the states of Paraná and S?o Paulo, Brazil. Lead content was determined spectrometrically by the atomic plasma induction method. Of the 30 samples analyzed, 9 had lead concentrations above 30 ppm (range 35.7 to 284.5 ppm) which is the maximum concentration recommended by the National Research Council (NRC 1980). These findings show the necessity for careful industrial monitoring because some mineral mixtures contain sufficient lead to cause toxicity.     

Identification of SA-MCFV DNA in blood, lymph node, and spleen of adult sheep, healthy cattle, and MCF cattle by PCR

Malignant catarrhal fever (MCF) is a highly fatal viral disease of cattle and other susceptible species of ruminants that occurs sporadically and is characterized by two epidemiological aspects. One is known as wildebeest-associated MCF (WA-MCF), whose agent is Alcelaphine herpesvirus-1, and the other is known as sheep-associated MCF (SA-MCF), whose agent is ovine herpesvirus-2 (OvHV-2). The researchers developed polymerase chain reaction (PCR) assay to detect OvHV-2 genome in three sample groups: (1) Peripheral blood lymphocytes from cattle with clinical signs of MCF (n = 15); (2) lymph node and spleen samples from healthy cattle (n = 68); and (3) lymph node and spleen samples from adult sheep (n = 82). All tissue specimens were collected randomly, and just one sample was taken from each animal. The PCR amplified a specific 422-bp SA-MCFV DNA fragment by pair primers 556 and 755 from samples. Of all 165 specimens, 44 samples had 422 bp SA-MCFV DNA fragment band (26.6%). Of 68 samples from healthy cattle, 20 samples were infected to OvHV-2 genome (29.41%), and of 82 healthy sheep specimens, nine samples were positive (10.98%). According to the data, the present study can confirm at least SA-MCF epidemiological form of the disease in sampling area. However, there may be another form, too. It is significant that infectivity rate of sheep samples was less than cattle, which suggests that healthy cattle are probably as important hidden carriers for OvHV-2 as sheep. In addition, positive lymph node sample rate was more than spleen samples in both groups 2 and 3. It may come from virus tropism to hide in the nearest lymphoid tissue and to cause latent infection.     

Social aggregations in cattle. II. Contributions of familiarity and genetic similarity

Social aggregations of three cattle breeds and crosses between them were studied under controlled conditions at a Brazilian research station. Cows raised with animals of their own breed in isolation from other breeds maintained segregated social gruops. Cattle of the same breed raised apart formed aggregations based more on familiarity than on genetic communality. There were breed differences in both of those tendencies. Hybrids were no more likely to associate with cattle with which they had one breed in common than with animals of completely different breeds, although having two breeds in common increased the likelihood that hybrids would be found together. Recently weaned calves did not assort themselves by shared kinship, but they formed phenotypic groupings correlated with color. In the absence of familiar individuals, cattle may use familiar phenotypes in establishing social preferences and cohesive herds.This research was supported, in part, by funds from the Brazilian government's Conselho Nacional de Pesquisa and the Fundação de Amparo de Pesquisa do Estado de São Paulo. Portions of this report were presented at the XVIII Annual Meeting of the Behavior Genetics Association, University of Nijmegen, Nijmegen, The Netherlands, 25 June 1988.     

Mastitis and fertility in cattle - possible involvement of inflammation or immune activation in embryonic mortality

Causes for pre-implantation embryo loss, which can be as high as 50% or more of fertilized embryos, are multifactorial and largely undescribed. Studies in cattle using mastitis as a model indicate that one cause of early embryonic loss is infectious disease or activation of immune responses at sites outside the reproductive tract. Infection of the mammary gland in dairy cattle is associated with a reduction in pregnancy rate (proportion of inseminated cows that become pregnant) and an increase in the number of inseminations required to establish pregnancy. Also, intravenous challenge with bacterial peptidoglycan and polysaccharide at approximately days 3-5 after breeding reduced subsequent pregnancy rate in sheep that had been previously immunized against the same material. The mechanism by which extrauterine activation of immune and inflammatory responses leads to embryonic loss is not clear although cytokines probably play a crucial role. Effects could be exerted at the level of the hypothalamic-pituitary axis, ovary, reproductive tract or embryo. Interferon (IFN)-alpha, for example, which can reduce pregnancy rate in cattle when injected around 13-19 days after breeding, increases body temperature, inhibits secretion of luteinizing hormone, and reduces circulating concentrations of progesterone. Other cytokines or products of cytokine activation could cause embryonic loss by causing hyperthermia (as elevated temperature blocks oocyte function and embryonic development), exerting toxic effects on the corpus luteum [for example, IFN-gamma, tumor necrosis factor-alpha (TNF-alpha) and prostaglandin F(2alpha)], stimulating endometrial prostaglandin synthesis [TNF-alpha and interleukin(IL)-1beta], reducing endometrial cell proliferation (IL-1beta), and interfering with oocyte maturation and embryonic development (TNF-alpha, nitric oxide, and prostaglandin F(2alpha)). Although largely neglected by reproductive immunologists, study of the involvement of the immune system in pre-implantation embryonic loss is likely to lead to new methods for enhancing fertility.     

云南宾川地区牛羊片形吸虫感染调查及分子鉴定

目的对云南宾川地区爆发人体片形吸虫病的村落进行牛羊的片形吸虫感染调查和检测,为当地片形吸虫病的研究提供数据。方法采用尼龙袋集卵法收集牛羊粪便中的虫卵,进行镜检。对检出的样本进行PCR扩增和测序;用MP法、NJ法及ML法进行种系发育分析。结果从134（28.63%）头牛和27（25.23%）头羊中查到了片形吸虫的虫卵,对所检到的虫卵进行线粒体pcox1基因的扩增和测序,比对后发现所检样本主要为肝片吸虫和大片吸虫两个种。采用MP法、NJ法及ML法进行种系发育分析表明,宾川地区牛羊感染的片形吸虫虫种主要为肝片吸虫和大片吸虫两种。结论宾川地区牛羊片形吸虫感染严重,云南宾川为肝片形吸虫及大片形吸虫混合感染地区,当地政府应重视该病的防治。