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为探讨氟致甲状腺肿大的分子机理，选用4周龄SD大鼠饮用不同浓度的NaF水溶液，复制了氟中毒致大鼠甲状腺肿模型，光镜下观察了甲状腺的形态结构变化，并用RT-PCR技术检测了甲状腺组织中iNOS1TIRNA和VEGFmRNA的表达情况。结果，氟中毒大鼠甲状腺微血管明显扩张、增生，表现为明显的结节性甲状腺肿；与正常对照组大鼠相比，氟中毒组大鼠甲状腺组织中iNOSmRNA和VEGFmRNA的表达水平显著升高（P〈0．05）。结果表明，长期摄入过量氟导致甲状腺发生结节性肿大的机理之一是，氟可刺激甲状腺中iNOS基因和VEGF基因的过量表达，进而造成甲状腺组织内微血管增生。 相似文献
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由碘缺乏引起的疾病叫碘缺乏病 ,也叫甲状腺肿大。1 病因主要原因是地球生物化学环境异常造成土壤和家畜饲料、饮水中碘不足 ,或因消化系统患病影响机体对碘的吸收 ,碘量消耗过多 ,碘在消化道被破坏等 ,都能引起本病。饲料中钙含量过多 ,饲料和饮水被细菌污染或长期摄入含生氰糖苷的饲料 (如亚麻子粉等 )均可引起碘的缺乏。碘缺乏的孕畜 ,常会导致胎儿也发生碘缺乏症。沙漠地区、灰化土及沼泽地区、水质过软或过硬的地区也常发生本病。饲养管理不良、中毒、传染病、寄生虫病 ,也容易产生碘缺乏病 ,特别是舍饲期以及泌乳的母畜更容易患病。2… 相似文献
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为探讨氟对鸡甲状腺摄碘功能的影响，选用250只I日龄蛋鸡，随机分为5组，每组50只，饲喂相同的全价日粮。第I组：正常对照组,Ⅱ、Ⅲ、Ⅳ、Ⅴ组在日粮中添加不同水平的氟化钠，使日粮中氟的含量分别为500，1000，1500，2000mg/kg，实验期为150d，每隔30d采集血样，测定血清中氟含量、甲状腺中碘含量，观察试验鸡的临床表现，结果表明，成功地复制出了不同程度的鸡慢性氟中毒模型；实验鸡日粮含碘量正常，各中毒组甲状腺中碘含量在整个实验期内均不同程序地低于对照组，呈明显的剂量-效应和时间-效应关系，甲状腺中碘含量变化和相应时期的血清氟含量间呈显著的负相关（r=-0.814)。说明氟能明显地抑制甲状腺摄取和聚集碘的能力，干扰碘的正常代谢，进而影响整个甲状腺的结构和功能。 相似文献
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为探讨氟对鸡甲状腺滤泡旁细胞结构的影响及氟引起甲状腺肿的机理 ,选用 2 50只 1日龄蛋鸡 ,随机分为 5组 ,每组 50只。第 1组为正常对照组 ;第 2 ,3,4,5组在日粮中添加不同水平的氟化钠 ,使日粮中氟的含量分别为 50 0 ,1 0 0 0 ,1 50 0 ,2 0 0 0mg/kg。试验期为 1 50d。测定血清中氟、钙含量 ,制作甲状腺组织切片和超薄切片 ,分别观察甲状腺滤泡旁细胞显微和超微结构的变化。结果表明 ,成功地复制出了不同程度的鸡慢性氟中毒模型 ,试验中后期 ,血清中氟与钙之间呈显著的正相关 (r=0 637,P<0 0 1 ) ;氟化物导致甲状腺滤泡旁细胞增生及损伤是氟导致甲状腺肿的机理之一。 相似文献
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氟对鸡甲状腺中碘代谢的影响 总被引：5，自引：1，他引：5
为探讨氟对鸡甲状腺中碘代谢的影响，选用250只1日龄蛋鸡，随机分为5组，每组50只，饲喂相同的全价日粮。第Ⅰ组：正常对照组，Ⅱ，Ⅲ，Ⅳ，Ⅴ组在日粮中添加不同水平的氟化钠，使日粮中氟的含量分别为500，1000，1500和2000mg/kg，试验期为150d，每隔30d采集血样，测定血清中氟含量、甲状腺中碘含量，观察试验鸡的临床表现。成功地复制出不同程度的鸡慢性氟中毒模型，试验鸡日粮含碘量正常。结果表明各中毒组甲状腺中碘含量在整个试验期内均不同程度地低于对照组，呈明显的剂量－效应和时间－效应关系。甲状腺中碘含量变化和相应时期的血清氟含量间呈显著的负相关（r=-0.814)。说明氟能明显地抑制甲状腺摄取和聚集碘的能力，干扰碘的正常代谢，进而影响整个甲状腺的结构和功能。 相似文献
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<正> 碘——作为人和动物生长的必需微量元素,最早得到人们的承认。近年来,不断有报道阐明,人类缺碘不仅会造成甲状腺肿、先天畸形等病症,而且很大比例的痴傻儿是由于缺碘引起的。我国是受碘缺乏病威胁较严重的国家,有四亿人口生活在碘缺乏病地区。随着物质生活水平的不断提高,人们逐渐认识到仅仅从天然食物中摄取碘是远远不够的,还需要在食物中添加碘,而通过饲料转换来提高人类食物中的碘含量则是人体补充碘的极好途径。 相似文献
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地方性氟中毒是一种生物地球化学性疾病,广泛分布于世界各大洲和我国十余个省份。氟在地圈中是一广布元素,它属于亲石元素,氟矿石的矿床往往是自然氟污染的地区,它构成了特殊的富氟化学地理区。但更具有化学地理意义的是各种类型的岩石中含氟量的差异性,土壤、饮水及生物有机体中氟的直接或间接来源,也是划分氟的化学地理区的重要因素。因而,家畜地方性氟中毒是严重危害牲畜健康的地方流行性疾病,急需引起重视。近几年来,我县部分奶牛场的奶牛发生不明原因的跛行及肢体异常生长现象,临床上则以慢性经过为主。经调查研究,初步诊断为奶牛地方性氟中毒,在病区也见有马、骡、母猪和绵羊等家畜发生不同程度的地方性氟中毒。 相似文献
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我国目前人群膳食中因碘的不足产生的后果令人忧虑。有关资料表明,世界上生活在碘缺乏地区的人口有10亿,其中我国就占4.25亿,除上海市外,其他省、市、自治区均有碘缺乏病流行。碘缺乏病严重威胁着人们的身体健康,特别是严重影响儿童的智力发育,消除碘缺乏病的最墓本措施是全民食盐加碘。而加入食盐中的碘为无机碘,易挥发难吸收,如碘盐存放、烹调方法不当,碘的利用率很低。鉴于这种情况,利用生物转化技术,积极开发高碘鸡蛋,投放市场,通过食物链,满足缺碘地区人民 相似文献
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Beran GW 《Preventive veterinary medicine》2008,86(3-4):198-207
When early people made their appearance, zoonotic infectious diseases were already waiting, but epidemic diseases did not appear in human history until people began to live in large numbers under conditions of close contact, mainly during the last 10,000 years. Disease has decimated urban populations, conquered armies, and disrupted society. The focus here is on (1) the plague of Athens and the Black Death; (2) smallpox, influenza, and rabies; (3) avian influenza prion diseases, and foot & mouth disease; and (4) emerging and re-emerging diseases. All have veterinary public health associations. In Athens, Greece, in 430 BC, when the Spartans ravaged the countryside, hordes crowded into Athens so that orderly movements, space in which to live, and adequate supplies of food became impossible. Crowding of any population fosters disease transmission; chaos and disorder enhance it all the more. Out of northern Egypt came a terrible plague from across the Mediterranean Sea. The identity of the plague of Athens remains unsure, but the well-considered conclusion is Rift Valley Fever, a mosquito borne, viral zoonosis. The Black Death, also called the Plague, raged in Asia for centuries. In 1347, the Black Death was brought by a ship out of Asia to Sicily. The scenes of devastation were repeated throughout Europe, with 90% or more of the people dying in city after city. Influenza, too, has been a cause of periodic human epidemics, but the great pandemic of influenza occurred in the last months of World War I. In the years of highest occurrence, more than half the world's population became clinically infected. If veterinary public health had been born earlier, it could have led to elucidating the epidemiology of influenza and the plagues of Athens, Europe, and Asia. In turn, smallpox had also caused continual tragedy. In 1796, Edward Jenner began to harvest pustules of cowpox from children or infected cows and inject them into susceptible children. In 1980, the World Health Organization declared that smallpox had been eliminated from the world. Rabies, though, still strikes terror. A number of animal diseases, broadly termed emerging and re-emerging diseases, need surveillance because they have the potential to impact human health. From late in 2003 to 2007, the highly pathogenic H5N1 influenza virus in poultry infected at least 121 people and caused 62 deaths in four countries. The prion diseases, too, all have very high numbers in concentrated contacts. To control these diseases, veterinary public health is essential, with diagnosis, epidemiological surveillance, clinical manifestations, and prevention as primary measures. 相似文献
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Dekker A Dercksen D Snoep J van Wuyjckhuise L 《Tijdschrift voor diergeneeskunde》2007,132(18):695-701
On 26th of july 2007 a new case of bluetongue was notified in the Netherlands and on 2nd of august 2007 foot-and-mouth disease was diagnosed in Surrey, England, which raised the threat of having both infections simultaniously in one area. Bluetongue and foot-and-mouth disease have a different pathogenesis, but symptoms may resemble each other at a later stage of infection. The pathogenesis and possible clinical symptoms of both infections are discussed and illustrated with pictures. 相似文献
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在动物的异常行为中以刻板行为最为常见,而咽气癖又是马最常见的口部刻板行为之一。作者就咽气癖在生理方面和心智方面对马体产生的影响、行为基础、诱因的研究进展及常见的防治措施进行综述。 相似文献
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近几年,世界饲用添加剂市场增长较快,预计今后将进一步增长,据世界粮农组织(FAO)首领会议的倡议,到2015年,将使世界营养不良的人口削减一半,其间,肉制品将会以每年2％的速度增长,特别是加快猪肉和禽肉增长。这将促进世界添加剂,尤其是蛋氨酸和赖氨酸需求量的增加。 相似文献
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