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1.
采用高效液相色谱法,在(23.1±0.8)℃水温条件下,对环丙沙星和磺胺二甲嘧啶两种抗菌药物在健康大菱鲆体内的代谢动力学规律进行了比较研究。结果显示,单次口服环丙沙星和磺胺二甲嘧啶后,药物在血浆中的经时过程均符合一级吸收二室开放模型,表达方程分别为CCIP=14.811e-0.337t+4.028e-0.063t-18.839e-0.616t、CSM2=64.981e-0.141t+4.59e-0.004t-69.571e-0.19t;静脉注射这两种药物后,药物在血浆中经时过程均符合无级吸收二室开放模型,表达方程分别为CCIP=21.784e-1.098t+1.514e-0.043t、CSM2=33.028e-5.687t+8.674e-0.013t。口服相同剂量(20 mg/kg)药物后,对血浆的药代动力学参数进行比较,环丙沙星的Tmax(6 h)、Cmax(5.385μg/mL)、t1/2Ka(1.125h)、t1/2α(2.057 h)和t1/2β(11.028 h)均小于磺胺二甲嘧啶给药(8 h、13.990μg/mL、3.647 h、4.923 h和173.407 h),且F(60.57%)大于磺胺二甲嘧啶给药F(47.13%)。证实环丙沙星在大菱鲆体内的吸收、分布、消除速度,达峰时间均快于磺胺二甲嘧啶给药,且比磺胺二甲嘧啶给药吸收完全。根据本实验的结果,环丙沙星和磺胺二甲嘧啶的合理给药方案分别为28.01 mg/kg和18.32 mg/kg,均为每日1次给药,连用3～5 d。  相似文献   

2.
探讨盐酸小檗碱在鸡体内的药动学特征。鸡以3mg／kg和50mg／kg剂量静脉注射和口服给药,采用HPLC法测定血浆中盐酸小檗碱的质量浓度。血药浓度-时间数据经DAS药代动力学分析软件处理,计算出药动学参数。结果表明：盐酸小檗碱静脉注射药时曲线符合三室开放模型,主要药动学参数分别为：t1／2β为（0．41±0．24）h,t1／2γ为（3．66±1．06）h,Vc为（25．49±21．77）L·kg^-1,CL为（43．20±16．21）L·h^-1·kg^-1,AUC为（78．92±30．58）μg·L^-1·h。盐酸小檗碱口服给药的药时曲线符合二室开放模型,主要药动学参数分别为：t1／2α为（1．87±0．76）h,t1／2β为（4．18±3.14）h,t1／2ka为（0．89±0．46）h,Tmax为（2．64±0．63）h,Cmax为（4．09±0．11）μg·L^-1,AUC为（26．18±10．73）μg·L^-1·h,绝对生物利用度为2．03％。鸡口服盐酸小檗碱的生物利用度低,消除较快。  相似文献   

3.
桔梗的“引经”作用对氟苯尼考药动学的影响   总被引：3，自引：0，他引：3  
20只新西兰白兔随机均分成2组(A、B组),A组单剂量1次灌胃内服氟苯尼考30 mg/kg;B组氟苯尼考30mg/kg与桔梗煎液2 g/kg单荆量1次同时灌胃内服给药;采用高效液相色谱法测定血药浓度,血药浓度最低检测限为0.05 mg/L,以3p97药代动力学程序和SPSSl2.0统计分析软件对所得数据进行分析.结果,药-时数据均符合一级吸收一室开放模型(W=1/C2),主要药代动力学参数及拟合方程如下.A组:T1/2ka(0.461±0.066)h,T1/2kc(2.013±0.195)h,Tpeak(1.180±0.123)h,Cmax(7.332±1.000)mg/L,AUC(31.445±3.566)mg·h-1·L-1,V/F(2.995±0.330)L/kg,拟合方程为:C=19.833(e-0.396t-e-2.387t);B组;T1/2ka(0.550±0.112)h,T1/2ke(3.308±0.270)h,Tpeak(1.414±0.183)h,Cmax(4.737±0.360)mg·L-1,AUC(23.128±2.096)mg·h-1·L-1,V/F(1.400±0.127)L/kg,拟合方程为:C-11.021(e-0.342t-e-10860t).结果表明,桔梗与氟苯尼考同时灌胃内服后,桔梗的"引经"对氟苯尼考在家兔体内药物代谢有较大影响.  相似文献   

4.
为了揭示复方银红涂膜在大鼠体内的药代动力学特性,试验采用高效液相色谱法(HPLC)测定大鼠血浆中复方银红涂膜指标成分羟基红花黄色素A的血药浓度。结果表明:当复方银红涂膜剂量为100 mg/kg时,分布半衰期(t1/2ɑ)=7.874 h,消除半衰期(t1/2β)=9.013 h,达峰时间(Tmax)=14.000 h,峰血药浓度(Cmax)=0.351μg/L,表观清除率(CL/F)=243.356 L/(h·kg),初始分布容积(V1/F)=182.438 L/kg,血药浓度-时间曲线下面积(AUC)=1.978 mg/(L·h)。说明复方银红涂膜中羟基红花黄色素A在大鼠体内呈二室模型分布。  相似文献   

5.
恩诺沙星在眼斑拟石首鱼体内的药物代谢动力学   总被引：15，自引：0，他引：15  
应用反相高效液相色谱法 (RP- HPL C)研究了恩诺沙星在眼斑拟石首鱼 (Sciaenops ocellatus)体内的药物代谢动力学。实验数据经 DAS药代动力学分析软件分析后得出 :腹腔注射组血浆的药时数据符合一级吸收二室模型 ,动力学方程为 :C =4 .92 5 e- 1 .4 52 t +2 .730 e- 0 .0 75t ,其主要药代动力学参数 :AU C37.5 33mg· L- 1· h、Cmax 4 .74 7mg/ L、Tmax0 .75 0 h、t α0 .4 77h、t β9.2 92 h、Vd/ F 1 .6 76 L / kg、t Ka0 .1 70 h、Ka 4 .0 81 / h、K 6 .71 4 / h、K1 0 0 .1 91 / h、K1 2 0 .76 9/h、K2 1 0 .5 6 6 / h;灌服组血浆的药时数据符合一级吸收一室模型 ,动力学方程为 :C =6 .4 82 (e- 7.0 92 t- e- 1 0 .356 t) ,其主要药代动力学参数 :AU C1 5 .80 5 mg· L- 1 · h、Cmax2 .770 mg/ L、Tmax1 .5 0 0 h、t α4 .989h、Vd/ F2 .0 72 L/ kg、Ka7.0 92 /h、K 1 0 .35 6 / h。结果表明 ,腹腔注射给药比灌服给药吸收快 ,血药浓度达峰时间短于灌服给药 ,但血药浓度峰值明显高于灌服给药 (P<0 .0 5 ) ,血浆中恩诺沙星的回收率为 94 .5 79%。  相似文献   

6.
为研究硫酸小檗碱微球在绵羊体内的药代动力学,选取10只绵羊,随机分为2组,分别颈部皮下注射2%硫酸小檗碱微球制剂和2%硫酸小檗碱水溶液,在不同时间点颈静脉采血,经前处理后利用高效液相色谱进行含量检测。通过DAS2.1.1软件进行数据统计分析,结果显示硫酸小檗碱微球组达峰时间T_(max)为8 h,消除半衰期T_(1/2Z)为5.22 h,达峰浓度C_(max)为0.31μg/mL,清除率C_(Lz/F)为0.46 L/(kg·h);而硫酸小檗碱水溶液组达峰时间T_(max)为1 h,消除半衰期T_(1/2Z)为2.35 h,达峰浓度C_(max)为0.28μg/mL,清除率C_(Lz/F)为2.21 L/(kg·h)。结果表明,硫酸小檗碱微球制剂与硫酸小檗碱水溶液相比具有更迟的达峰时间(P0.05),更长的消除半衰期(P0.05),在体内可起到缓释的效果。  相似文献   

7.
甲砜霉素在感染多杀性巴氏杆菌鸡体内的药物动力学   总被引：2，自引：0，他引：2  
30只健康杂交肉鸡随机分成3组,每组10只,雌雄各半,分别进行健康鸡静脉注射、健康和巴氏杆菌感染鸡口服给药的药动学研究。静注和口服的给药剂量按体质量分别为15mg/kg和30mg/kg。以反相HPLC测定血浆中甲砜霉素的质量浓度,药物浓度-时间数据用3P97药动学程序软件处理。健康鸡单剂量静注给药后,血药浓度-时间数据符合无吸收二室开放模型,其主要动力学参数分别为:V(c)为(0.58±0.09)L/kg,t1/2α(0.11±0.03)h,t1/2β(0.95±0.18)h,AUC为(11.99±0.90)mg/(L.h),CL(s)为(1.26±0.10)L/(kg.h)。健康鸡和巴氏杆菌感染鸡单剂量口服给药血药浓度-时间数据均符合一级吸收一室开放模型。健康鸡口服给药的主要动力学参数分别为:Lagtime(0.04±0.02)h,t1/2ka(0.16±0.08)h,t1/2ke(1.64±0.22)h,T(peak)(0.57±0.18)h,C(max)(6.34±0.56)mg/L,AUC为(19.02±1.48)mg/(L.h),F为79.32%。巴氏杆菌感染鸡口服给药的主要动力学参数分别为:Lagtime(0.07±0.02)h,t1/2ka(0.54±0.26)h,t1/2ke(1.74±0.27)h,T(peak)(1.31±0.39)h,C(max)(5.28±0.73)mg/L,AUC为(21.75±1.03)mg/(L.h),F90.70%。与健康鸡相比,甲砜霉素在感染鸡的t1/2(ka)、T(peak)和Lag-time显著延长(P0.05或P0.01),且比健康鸡具有更高的生物利用度。但甲砜霉素在巴氏杆菌感染鸡体内的消除速度未受影响。  相似文献   

8.
盐酸多西环素缓释注射液在猪体内的药物动力学   总被引：2，自引：0，他引：2  
健康猪6头,体质量(17.85±1.3)kg,按拉丁方设计进行单剂量静注、肌注盐酸多西环素注射液(普通制剂)和肌注盐酸多西环素缓释注射液,注射剂量按多西环素计均为20 mg/kg,比较盐酸多西环素缓释注射液和盐酸多西环素注射液在猪体内的药动学特征和生物利用度.用高效液相色谱法测定其血药浓度,试验所得的血药浓度-时间数据采用非房室模型统计矩原理分析处理.猪静注盐酸多西环素注射液的主要药物动力学参数为AUC(108.15±13,25)mg·h·L-1,MRT(5.56±1.08)h,CI(0.19±0.02)L·h-1·kg-1,Vd(ss)(1.04±0.09)L·kg-1,t1/2(4.07±0.65)h.猪肌注盐酸多西环素注射液和盐酸多西环素缓释注射液的主要药物动力学参数分别为MRT(15.18±2.13)h和(22.25±3.49)h;Tmax(1.135±0.44)h和(2.0±0.63)h;Cmax(3.32±0.33)mg·L-1和(3.10±0.29)mg·L-1;AUC(38.91±4.35)mg·h·L-1和(61.72±10.16)mg·h·L-1;F(36.66±7.88)%和(57.66±10.75)%.比较盐酸多西环素注射液和盐酸多西环素缓释注射液的主要药动学参数,除了Cmax以外,MRT、Tmax、AUC、F等主要参数均有显著的统计学意义(P＜0.05).这表明盐酸多西环素缓释注射液肌注后吸收缓慢.消除半衰期延长,临床用药48 h给药1次仍能维持对常见病原菌的有效血药浓度.  相似文献   

9.
24只苏禽黄羽肉鸡随机分成2组,分别按10 mg/kg体重剂量静注和内服乳酸恩诺沙星。测定乳酸恩诺沙星在鸡体内的药动学参数和生物利用度。恩诺沙星血药浓度数据用3p87计算机软件处理。静注乳酸恩诺沙星后的血药浓度-时间数据符合二室开放模型,主要动力学参数:t1/2α(0.45±0.16)h,t1/2β(7.02±1.42)h,CL(s)(0.38±0.10)L/kg/h,AUC(23.69±5.56)(mg/L)×h。内服乳酸恩诺沙星的血药浓度时间数据,符合有吸收因素二室模型,主要动力学参数:t1/2ka(0.60±0.01)h,t1/2ke(8.25±1.73)h,tpeak(2.44±0.17)h,Cmax(1.44±0.30)mg/L,AUC(20.74±3.80)(mg/L)×h,F 87.54%。结果表明,乳酸恩诺沙星可溶性粉在鸡体内具有吸收快、分布广、消除较慢以及内服生物利用度高的药动学特征。  相似文献   

10.
盐酸多西环素在猪体内的药物动力学及其残留   总被引：5，自引：0，他引：5  
试验建立了反相高效液相色谱(RT-HPLC)法测定盐酸多西环素的浓度,探讨了盐酸多西环素在猪体内的药物动力学和残留特征。结果表明,盐酸多西环素以2.5mg/kg单剂量肌内注射给猪(n=6),药物动力学模型符合有吸收一室模型,药物动力学参数:吸收半衰期(t1/2ka)、消除半衰期(t1/2ke)为(0.400±0.312)h、(9.530±0.956)h,药时曲线下面积(AUC)为(44.414±4.123)mg·h·L-1,最大血药浓度(Cmax)为(2.811±0.136)mg/L,达峰时间(Tp)为(1.910±0.213)h。另外,以相同剂量肌内注射给猪(n=6),每天1次,连续给药4d后,在不同时间测定盐酸多西环素在猪的肌肉、肝脏、肾脏、皮肤和脂肪中的残留量。在给药后16d,盐酸多西环素在各组织均能检测到,且残留均低于残留限量。盐酸多西环素注射液在猪体内消除缓慢,残留期较长,建议休药期不低于16d。  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.
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   

14.
Human and equine athletes are reported to have a high prevalence of gastric disease, and anecdotal evidence suggests a similar phenomenon applies to racing sled dogs. To investigate the prevalence of gastric disease in racing sled dogs, we conducted 2 gastroscopy studies on dogs competing in the annual Iditarod Sled Dog Race. A pilot study of dogs that were either dropped from the 2000 Iditarod Sled Dog Race because of illness or that finished the race indicated that, approximately 5 days after competing, 10 of 28 dogs (35%) had endoscopic evidence of gastric ulceration, erosion, or hemorrhage. The next year, an endoscopic study of 73 dogs participating in the 2001 Iditarod race was performed in order to evaluate a larger population of dogs. Data from 70 of these dogs could be used; 34 (48.5%) had ulceration, erosion, gastric hemorrhage, or some combination of these findings. When this group of 70 dogs was compared retrospectively to a control group of 87 dogs presented to the Texas A&M University (TAMU) Veterinary Medical Teaching Hospital, the Iditarod sled dogs had a significantly higher prevalence (P = .049) of gastric lesions. These findings suggest that, similar to athletes of other species, elite canine athletes have an increased prevalence of gastric disease compared to the canine population at large.  相似文献   

15.
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   

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.
The purpose of this study was to determine the frequency of different tumor types within a large cohort of cats with intracranial neoplasia and to attempt to correlate signalment, tumor size and location, and survival time for each tumor. Medical records of 160 cats with confirmed intracranial neoplasia evaluated between 1985 and 2001 were reviewed. Parameters evaluated included age, sex, breed, FeLV/FIV status, clinical signs, duration of signs, number of tumors, tumor location(s), imaging results, treatment, survival times, and histopathologic diagnosis. Most of the cats were older (11.3 +/- 3.8 years). Primary tumors accounted for 70.6% of cases. Metastasis and direct extension of secondary tumors accounted for only 5.6 and 3.8% of cases, respectively. Twelve cats (7.5%) had 2 or more discrete tumors of the same type, whereas 16 cats (10.0%) had 2 different types of intracranial tumors. The most common tumor types were meningioma (n = 93, 58.1%), lymphoma (n = 23, 14.4%), pituitary tumors (n = 14, 8.8%), and gliomas (n = 12, 7.5%). The most common neurological signs were altered consciousness (n = 42, 26.2%), circling (n = 36, 22.5%), and seizures (n = 36, 22.5%). Cats without specific neurological signs were common (n = 34, 21.2%). The tumor was considered an incidental finding in 30 (18.8%) cats. In addition to expected relationships (eg, meninges and meningioma, pituitary and pituitary tumors), we found that lesion location was predictive of tumor type with diffuse cerebral or brainstem involvement predictive of lymphoma and third ventricle involvement predictive of meningioma.  相似文献   

18.
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   

19.
The occurrence of ectoparasites in sheep flocks is frequently reported but seldom quantified. Sheep production used to be a predominantly family activity in the state of Sa~o Paulo (Brazil), but it began to become a commercial activity in the past decade. Thus, information about the ectoparasites existing in sheep flocks has become necessary. The present data were obtained by means of questionnaires sent to all sheep breeders belonging to the `Associaça~o Paulista de Criadores de Ovinos' (ASPACO; Sa~o Paulo State Association of Sheep Breeders). Response reliability was tested by means of random visits paid to 10.6% of the respondents. Most of the properties (89.5%) reported the presence of one or more ectoparasites. Screw-worm (Cochliomyia hominivorax) was the most frequent ectoparasite (72.5%), followed by bot fly larvae (Dermatobia hominis, 45.0%), ticks (Amblyomma cajennense) and Boophilus microplus, 31.3%) and finally lice (Damalinia ovis, 13.8%). Combined infestations also occurred, the most common one being screw-worm with bot fly larvae (36.0%) followed by bot fly larvae with ticks (13.9%), screw-worm with ticks (9.3%), bot fly larvae with lice (6.9%), and ticks with lice (5.0%). The most common triple combination was screw-worm, bot fly larvae and ticks (12.8%). Breeds raised for meat or wool were attacked by bot fly larvae and ticks more often than other breeds. Lice were only absent from animals of indigenous breeds. The relationships among these ectoparasites are discussed in terms of sheep breeds, flock size, seasonality and the ectoparasitic combinations on the host.  相似文献   

20.
Infectious diseases have always been a terrible scourge for humans. The appearance of these plagues, as they were called without distinction, was generally connected to various conditions: asters, climatic changes or religious reasons. The concept of contagious, and then infectious, diseases came slowly. Variolation, i.e. transmission of ‘virulent’ matter to induce a natural disease and the immunity against it, was brought from Constantinople to England by Lady Montague, in 1721. This ‘variolation’ technique was also often performed in veterinary medicine against diseases like sheep-pox or pleuropneumonia. As ‘vaccination’ is the term generally accepted for ‘immunisation’, variolation can be the word designating such a technique. The second period of the history of immunisation began, in 1880, with the studies of Pasteur and his collaborators. A great number of bacterial vaccines were developed: dead, live but attenuated or only parts of pathogens. The viruses were produced in animals, then in eggs and at last, in tissue cultures. Second generation vaccines appeared with genetic engineering: recombinant vaccines, vector vaccines, nucleic acids vaccines, and markers vaccines, among others. These novel technologies can permit the development of new ones and improve the quality of the vaccines already existing.  相似文献   

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