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1.
稀土元素的肝脏蓄积性及毒性危害   总被引:6,自引:0,他引:6  
综合论述了稀土元素在机体肝脏的蓄积性及其毒性效应,分析了稀土农业应用对生态环境和人群健康的危害.稀土元素被长期低剂量摄入,可在肝脏中蓄积,导致肝脏形态和病理组织变化、肝细胞损伤、肝代谢紊乱引起脂肪肝;高于2 mg·kg-1剂量的农用稀土(常乐)仍能通过胎盘屏障引起肝细胞和发育中的红细胞DNA损伤.  相似文献   

2.
氧化应激的产生及其对畜禽肝脏功能的影响与机制   总被引:1,自引:0,他引:1  
现代畜牧业规模化生产中,养殖环境、饲粮构成、饲养方式等诸多因素变化可诱发畜禽产生氧化应激。氧化应激对畜禽的肝脏功能有负面作用,危害畜禽健康和生产。机体发生氧化应激时,大量的氧自由基在肝细胞内蓄积,通过损伤生物大分子物质、破坏肝细胞结构、影响细胞器功能、诱发肝细胞凋亡等,对肝脏造成严重损伤,并引发多种肝脏疾病。本文从机体氧化应激产生、氧化应激对肝脏功能的影响以及氧化应激影响肝脏功能的可能分子机制等方面进行综述,以期为缓解氧化应激危害提供理论依据。  相似文献   

3.
1病因分析急性实质性肝炎是在致病因素的作用下,肝脏发生以肝细胞变性、坏死为主要特征的炎症。本病各种家畜、家禽都有发生。急性实质性肝炎主要是由传染性因素与中毒性因素引起。常见的传染性因素有细菌性因素、病毒性因素和寄生虫性因素。细菌性因素,如链球菌、葡萄球菌、坏死杆菌、结核杆菌、牛沙门氏菌及钩端螺旋体等都可引起肝炎。病毒性因素,犬病毒性肝炎病毒、鸭病毒性肝炎病毒等都可引起肝炎。寄生虫性因素,弓形虫、球虫、肝片吸虫、血吸虫等感染,可发生肝炎。进入肝脏的病原体,不仅可以破坏肝组织而产生毒性物质,同时其自身在代谢过程中也释放大量毒素,并且还以机械损伤作用使肝脏受到损伤,导致肝细胞变性、坏死。  相似文献   

4.
霉菌毒素中毒引起母猪繁殖障碍的主要原因是由于猪只采食了发霉腐烂的饲料后引起的一种中毒性疾病,并且在各种年龄、品种的猪都可引起发生。妊娠母猪和小乳仔猪更为敏感。妊娠母猪和商品猪均从肝脏受到侵害。表现为肝脏充血和出血,在肝脏、肾脏实质变性、坏死导致肝细胞变性、胆管和肝细胞增生、怀孕母猪流产、公猪产生包皮炎和阴茎肿胀。  相似文献   

5.
猫脂肪肝是由于肝脏细胞聚积大量脂肪而造成肝脏功能紊乱的疾病。其特征为肝脏正常脂肪代谢出现异常,大量的甘油三酸酯蓄积于肝细胞内。对猫而言,由于其具有特异性的在肝脏中储存脂肪的功能,最容易发生肝细胞损伤和肝功能异常。  相似文献   

6.
猫脂肪肝是由于肝脏细胞聚积大量脂肪而造成肝脏功能紊乱的疾病.其特征为肝脏正常脂肪代谢出现异常,大量的甘油三酸酯蓄积于肝细胞内.对猫而言,由于其具有特异性的在肝脏中储存脂肪的功能,最容易发生肝细胞损伤和肝功能异常.  相似文献   

7.
稀土元素在家兔饲料中的应用   总被引:2,自引:0,他引:2  
稀土元素是元素周期表中镧系元素和化学性质相似的钪,钇等17种元素的总称,由于它具有特殊的结构和较强的活性,近年来,在家兔饲料中的应用日渐广泛,并取得了良好的效果。1稀土元素的种类稀土元素分轻稀土元素和重稀土元素两类。目前常用的多为轻稀土元素,其原子序数小,离子半径大,呈弱碱性,通常以三价离子状态存在,其产品主要有:硝酸稀土,盐酸稀土,碳酸稀土和维生素C—稀土。在家兔饲养中应用最多的为硝酸稀土。2稀土元素在体内的分布与代谢2.1分布:稀土元素广泛存在于肺、肾、肝、脾、心、血、毛等组织器官中,但并非均匀分布…  相似文献   

8.
<正>1病因犬肝脏对高脂肪、病毒、寄生虫、毒物等造成损伤的应答反应,当犬的血清中胆红素浓度超过34umol/L时,组织发生黄染,可确诊为黄疸。黄瘟以良种犬或杂交犬多发,地方土种犬发病较少。肝细胞是胆红素代谢的主要器官,肝细胞的损伤会影响胆红素的摄取、结合、分泌和排泄,导致血清胆红素增高出现肝细胞性黄疸。肝细胞内和胆小管及肝内小胆管胆汁郁积。也可引起血  相似文献   

9.
试验采取检测各攻毒组小鼠肝脏受损情况、肝脏细胞凋亡及相关凋亡机制。结果显示,三聚氰胺及其三聚氰酸混合物对小鼠肝脏的损伤随着混合物剂量的上升呈量效关系,剂量越高损伤作用越严重,而三聚氰胺单独组和三聚氰酸单独组对小鼠肝脏无明显损伤作用。三聚氰胺与三聚氰酸混合物主要是通过诱导小鼠肝脏细胞凋亡而致肝组织损伤,Bax和caspase-3基因参与了三聚氰胺和三聚氰酸诱导小鼠肝细胞凋亡的调控。  相似文献   

10.
为研究镉对肉鸡肝脏、肾脏的病理学损伤及锌和N-乙酰半胱氨酸(NAC)分别对镉中毒肉鸡肝、肾病理学损伤的拮抗作用,对AA肉鸡肌肉注射Cd(2+)(1 mg/kg BW和5 mg/kg BW)建立梯度镉中毒模型,同时采用肌肉注射的方式向镉中毒肉鸡补充Zn~(2+)(5 mg/kg BW)或NAC(50 mg/kg BW)。结果表明,镉中毒10 d和20 d后,肉鸡肝脏、肾脏呈现严重的病理学损伤,补充Zn~(2+)或NAC后镉中毒肉鸡肝脏充血现象减轻,肝细胞坏死数减少,肝细胞空泡结构、颗粒性变性现象减轻,肝脏内炎性细胞浸润量显著减少。肾脏出血减轻,肾小管管腔形态好转,肾细胞空泡结构、颗粒变性减轻,肾细胞排列紧密,细胞间间隙减小,肾细胞核消失和肾脏炎性细胞量显著减少。说明镉中毒可以造成肉鸡肝脏和肾脏严重的病理学损伤,Zn~(2+)或NAC补充能有效抑制镉中毒引起的肉鸡肝、肾病理学损伤。  相似文献   

11.
试验选用96头平均体重14.82 kg左右的杜×长×大断奶仔猪,随机分成4组,每组3栏,每栏8头(公母各半)。对照组饲喂基础日粮,试验1、2、3组分别添加1%80目白术、0.2%白术多糖和1%微米白术。试验期30 d。结果表明:在生长性能方面,与对照组相比,1%微米白术添加组可显著提高日增重(P0.05)、降低饲料增重比和腹泻率,而且效果优于1%80目白术组和0.2%白术多糖组,在肠道形态和肠道微生态区系方面,与对照组相比,日粮添加1%80目白术、0.2%白术多糖、1%微米白术均可不同程度的提高十二指肠和空肠的绒毛高度,加深十二指肠和空肠的隐窝深度,并且增加肠道微生态区系的多样性,其中以1%微米白术添加组的效果最佳。  相似文献   

12.
Sissay, M.M., Uggla, A. and Waller, P.J., XXXX. Prevalence and seasonal incidence of nematode parasites and fluke infections of sheep and goats in eastern Ethiopia. Tropical Animal Health and Production, XXXX. A 2-year abattoir survey was carried out to determine the prevalence, abundance and seasonal incidence of gastro-intestinal (GI) nematodes and trematodes (flukes) of sheep and goats in the semi-arid zone of eastern Ethiopia. During May 2003 to April 2005, viscera including liver, lungs and GI tracts were collected from 655 sheep and 632 goats slaughtered at 4 abattoirs located in the towns of Haramaya, Harar, Dire Dawa and Jijiga in eastern Ethiopia. All animals were raised in the farming areas located within the community boundaries for each town. Collected materials were transported within 24 h to the parasitology laboratory of Haramaya University for immediate processing. Thirteen species belonging to 9 genera of GI nematodes (Haemonchus contortus, Trichostrongylus axei, T. colubriformis, T. vitrinus, Nematodirus filicollis, N. spathiger, Oesophagostomum columbianum, O. venulosum, Strongyloides papillosus, Bunostomum trigonocephalum, Trichuris ovis, Cooperia curticei and Chabertia ovina), and 4 species belonging to 3 genera of trematodes (Fasciola hepatica, F. gigantica, Paramphistomum {Calicohoron} microbothrium and Dicrocoelium dendriticum) were recorded in both sheep and goats. All animals in this investigation were infected with multiple species to varying degrees. The mean burdens of adult nematodes were generally moderate in both sheep and goats and showed patterns of seasonal abundance that corresponded with the bi-modal annual rainfall pattern, with highest burdens around the middle of the rainy season. In both sheep and goats there were significant differences in the mean worm burdens and abundance of the different nematode species between the four geographic locations, with worm burdens in the Haramaya and Harar areas greater than those observed in the Dire Dawa and Jijiga locations. Similar seasonal variations were also observed in the prevalence of flukes. But there were no significant differences in the prevalence of each fluke species between the four locations. Overall, the results showed that Haemonchus, Trichostrongylus, Nematodirus, Oesophagostomum, Fasciola and Paramphistomum species were the most abundant helminth parasites of sheep and goats in eastern Ethiopia.  相似文献   

13.
14.
1-(2-Chloroethyl)3-cyclohexyl-1-nitrosourea (CCNU) is an alkylating agent in the nitrosourea subclass. A prospective evaluation of CCNU was done to determine the maximally tolerated dosage of CCNU in tumor-bearing cats. Response data were obtained when available. Twenty-five cats were treated with CCNU at a dosage of 50-60 mg/m3 body surface area. Complete hematologic data were available for 13 cats. Neutropenia was the acute dose-limiting toxicity. The median neutrophil count at the nadir was 1,000 cells/microL (mean, 2,433 cells/microL; range, 0-9,694 cells/microL). The time of neutrophil nadir was variable, occurring 7-28 days after treatment, and counts sometimes did not return to normal for up to 14 days after the nadir. Based on these findings, a 6-week dosing interval and weekly hematologic monitoring after the 1st treatment with CCNU are recommended. The nadir of the platelet count may occur 14-21 days after treatment. The median platelet count at the nadir was 43,500 cells/microL. No gastrointestinal, renal, or hepatic toxicities were observed after a single CCNU treatment, and additional studies to evaluate the potential for cumulative toxicity should be performed. Five cats with lymphoma and 1 cat with mast cell tumor had measurable responses to CCNU. Phase II studies to evaluate antitumor activity should be completed with a dosing regimen of 50-60 mg/m3 every 6 weeks.  相似文献   

15.
Our particular attention in this article was given to natural mediators for macrophages isolated from the sites of tissue injury. A number of chemotactic factors, which may satisfy many criteria making them acceptable as inflammatory leucocyte chemotactic factors, has been separated. Among them, our laboratory has isolated three macrophage (monocyte) chemotactic factors (MCF-a, -b and -c). Their purification, characterization and functional specificity are discussed.  相似文献   

16.
Continuous rate infusion (CRI) of furosemide in humans is considered superior to intermittent administration (IA). This study examined whether furosemide CRI, compared with IA, would increase diuretic efficacy with decreased fluid and electrolyte fluctuations and activation of the renin-angiotensin-aldosterone system (RAAS) in the horse. Five mares were used in a crossover-design study. During a 24-hour period, each horse received a total of 3 mg/kg furosemide by either CRI (0.12 mg/kg/h preceded by a loading dose of 0.12 mg/kg IV) or IA (1 mg/kg IV q8h). There was not a statistically significant difference in urine volume over 24 hours between methods; however, urine volume was significantly greater after CRI compared with IA during the first 8 hours ([median 25th percentile, 75th percentile]: 9.6 L [8.9, 14.4] for CRI versus 5.9 L [5.3, 6.0] for IA). CRI produced a more uniform urine flow, decreased fluctuations in plasma volume, and suppressed renal concentrating ability throughout the infusion period. Potassium, Ca, and Cl excretion was greater during CRI than IA (1,133 mmol [1.110, 1,229] versus 764 mmol [709, 904], 102.7 mmol [96.0, 117.2] versus 73.3 mmol [65.0, 73.5], and 1,776 mmol [1,657, 2.378] versus 1,596 mmol [1,457, 1,767], respectively). Elimination half-lives of furosemide were 1.35 and 0.47 hours for CRI and IA, respectively. The area under the excretion rate curve was 1,285.7 and 184.2 mL x mg/mL for CRI and IA, respectively. Furosemide CRI (0.12 mg/kg/h) for 8 hours, preceded by a loading dose (0.12 mg/kg), is recommended when profound diuresis is needed acutely in horses.  相似文献   

17.
Genetic variations in chromosome Y are enabling researchers to identify paternal lineages, which are informative for introgressions and migrations. In this study, the male‐specific region markers, sex‐determining region‐Y (SRY), amelogenin (AMELY) and zinc finger (ZFY) were analysed in seven Turkish native goat breeds, Angora, Kilis, Hair, Honaml?, Norduz, Gürcü and Abaza. A SNP in the ZFY gene defined a new haplotype Y2C. All domestic haplogroups originate from Capra aegagrus, while the finding of Y1A, Y1B, Y2A and Y2C in 32, 4, 126 and 2 Turkish domestic goats, respectively, appears to indicate a predomestic origin of the major haplotypes. The occurrence of four haplotypes in the Hair goat and, in contrast, a frequency of 96% of Y1A in the Kilis breed illustrate that Y‐chromosomal variants have a more breed‐dependent distribution than mitochondrial or autosomal DNA. This probably reflects male founder effects, but a role in adaptation cannot be excluded.  相似文献   

18.
The objective of this report was to characterize 20-year changes in proportion of calcium oxalate (CaOx) calculi and struvite calculi in dogs, and associations with breed, age, and sex. In this retrospective study, results of analysis of urinary calculi from dogs were reviewed for specimens received between July 1, 1981, and December 31, 2001. Breed, sex, age, year of submission of the specimen, and mineral type(s) were analyzed statistically. CaOx or Struvite or both were contained in 18,966 of 20,884 (91%) specimens. For both sexes, a 20-year statistically significant increase was observed in the proportion of calculus specimens that contained CaOx. The increase in this proportion was greater in females (1% to 31%) than in males (18% to 82%). From 1998 to 2001, when proportions may have plateaued, the odds of specimens containing CaOx were markedly higher in 18 breeds, markedly lower in 5 breeds, and not significantly different in 13 breeds compared with crossbreds. For both sexes, a 20-year statistically significant decrease was observed in the proportion of calculus specimens that contained struvite. This decrease in proportion was greater for males (79-16%) than for females (97-68%). From 1998 to 2001, when proportions plateaued, the odds of calculi containing struvite were markedly lower in 20 breeds, markedly higher in 1 breed, and not significantly different in 15 breeds when compared with crossbreds. Breed, age, and sex were associated statistically with CaOx or struvite urolithiasis. In conclusion, there appears to have been a long-term increase in the proportion of specimens of canine urinary calculi that contain CaOx as well as a long-term decrease in the proportion of specimens of calculi that contain struvite for both male and female dogs. The rate of change appeared to begin leveling off in the period 1998 to 2001. The recent proportion of dogs with either CaOx- or struvite-associated urolithiasis may depend on breed, age, and sex, and on interactions among these 3 factors.  相似文献   

19.
<正>1.INTRODUCTION Ensuring transportation network security is one Of the most daunting challenges confronting homeland security agencies today.Significant research has been dedicated.To model and analyze the vulnerability of transportation systems,while notably fewer studies propose specific strategies for deploying defensive technologies to safeguard these systems.  相似文献   

20.
The epidemiology of H. placei and of other gastrointestinal nematodes in yearling dairy cattle was examined on two farms in Kiambu District, central Kenya during each of 13 one-month periods from April 1993 to April 1994. On each farm, 32 newly weaned dairy calves were given a single dose of albendazole and then placed on experimental pastures. Twelve of the animals were designated for bi-monthly slaughter (n = 2) and analysis of worm population characteristics and 20 were designated for blood and faecal collection and for weighing. Two parasite-free tracer calves were grazed alongside the weaner calves each month throughout the study period and were also slaughtered for analysis of worm populations. Faecal egg counts, haematological and serum pepsinogen determinations, herbage larval counts, and animal live weight changes were recorded monthly. The study revealed that Haemonchus placei, Trichostrongylus axei, Cooperia spp. and Oesophagostomum radiatum were responsible for parasitic gastroenteritis and that H. placei was the predominant nematode present in the young cattle on both farms. Faecal egg counts from resident cattle and necropsy worm counts revealed that pasture larval levels were directly related to the amount of rainfall. The total worm burdens in the animals were highest during the rainy season (March–June and October–December) and lowest during the dry seasons (July–September and January–February). The very low recovery of immature larvae of H. placei from the tracer calves indicated that arrested development is not a feature of the life cycle of this parasite in central Kenya. The maintenance of the parasite population depended on continuous cycling of infection between the host and the pasture. The agroclimatic conditions of the study area were such that, in general, favourable weather conditions for the development and survival of the free-living stages of gastrointestinal nematodes existed all year round.  相似文献   

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