鸡血浆中磺胺氯吡嗪钠和甲氧苄啶含量HPLC检测方法的建立

建立了鸡血浆中磺胺氯吡嗪钠和甲氧苄啶含量测定的HPLC方法。对鸡血浆中磺胺氯吡嗪和甲氧苄啶采用乙腈提取和净化,梯度洗脱,高效液相色谱紫外检测法测定,外标法定量。流动相为甲醇-0.02 mol/L磷酸二氢钾水溶液。紫外测定时采用双波长检测:磺胺氯吡嗪检测波长为268 nm,甲氧苄啶检测波长为240 nm。空白血浆添加磺胺氯吡嗪和甲氧苄啶分别在0.1～70.0μg/m L和0.05～5.00μg/m L范围内线性关系良好(R~2均大于0.9999),磺胺氯吡嗪和甲氧苄啶的检测限分别为0.05μg/m L和0.025μg/m L,定量限分别为0.1μg/m L和0.05μg/m L。空白血浆添加磺胺氯吡嗪和甲氧苄啶在各自线性范围内,批内变异系数分别小于6.84%和7.55%,批间系数分别小于5.23%和6.81%。本研究建立的鸡血浆中磺胺氯吡嗪和甲氧苄啶的提取和净化方法,适用于鸡血浆中磺胺氯吡嗪和甲氧苄啶含量的单个或同时测定。     

鸡肝组织中磺胺类药物多残留分析法

建立了鸡肝组织中磺胺嘧啶、磺胺二甲基嘧啶、磺胺甲氧吡嗪、磺胺－6－甲氧嘧啶、磺胺甲恶唑、磺胺－2，6－二甲氧嘧啶和磺胺喹恶啉的多残留高效液相色谱分析法。样品经乙腈提取、正己烷液－液分配和碱性氧化铝柱固相萃取法净化后用反相高效液相色谱法测定（UV270nm）。7种磺胺类药物标准曲线的相关系数（r^2)为0．9991－1．0000（0.01μg/ml-0.5μg/ml）。在0.05mg/kg-0.5mg/kg浓度范围内，磺胺类药物的回收率为68．8％－100．0％，变异系数为1．3％－12．0％。 检测限为0．01mg/kg-0.03mg/kg，定量限低于0.05mg/kg。     

高效液相色谱法测定鸡蛋中氯霉素残留量

采用高效液相色谱法(HPLC)检测鸡蛋中氯霉素的残留量。鸡蛋(全蛋)试样中残留的氯霉素用乙酸乙酯提取,35℃减压蒸干。残渣用正己烷-氯仿(1 1,V/V)溶解,加少量水,混匀后,离心,取上清液作为试样溶液供高效液相色谱仪(紫外检测器)在280nm处测定,外标法定量。本方法在鸡蛋中检出限为2μg/kg,回收率在60％～90％,批内变异系数小于12.0％,批间变异系数小于15.0％。     

超高效液相色谱-串联质谱法同时检测鸡蛋中5种磺胺类药物和甲氧苄啶残留量

建立超高效液相色谱-串联质谱法(Ultrahigh-performance liquid chromatography-tandem mass spectrometry, UPLC-MS/MS)同时测定鸡蛋中5种磺胺类药物(磺胺甲恶唑、磺胺二甲嘧啶、磺胺间甲氧嘧啶、磺胺喹噁啉、磺胺二甲氧嘧啶)和甲氧苄啶的残留量的方法。样品经乙腈提取2次, 95%乙腈溶液进行溶解后,过Alumina B Cartridges柱,30%乙腈洗脱,滤膜过滤后滤液用于超高效液相色谱-串联质谱仪测定,外标基质标准曲线法定量。在0.5～100μg/kg的浓度范围内5种磺胺类药物和甲氧苄啶色谱峰面积与浓度呈良好线性相关,相关系数均大于0.99;方法检测限0.5μg/kg、定量限为1.0μg/kg;鸡蛋样品中5种磺胺类药物和甲氧苄啶在1.0～100.0μg/kg添加水平内的平均回收率在66.3%～97.5%之间,批内、批间相对标准偏差在1.4%～11.4%之间。该方法回收率满足残留检测要求,且方法的重现性良好,满足国内外兽药残留相关法规规定。     

牛奶中氯唑西林残留量的高效液相色谱法测定

为建立高效液相色谱法测定牛奶中氯唑西林残留的方法,牛奶样品用乙腈沉淀蛋白,三氯甲烷反萃取,有机相旋干用流动相溶解,正己烷除脂。0.02mol/L磷酸二氢钾溶液(pH 5.0)-乙腈(68∶32)比例为流动相,C18反相色谱柱分离,紫外检测。结果氯唑西林在15μg/kg～1 000μg/kg范围内呈现良好的线性关系,相关系数大于0.999 0;在15、30、60μg/kg三个添加水平,氯唑西林在牛奶中的平均回收率为70.25%～94.38%,批内变异系数小于8.34%,批间变异系数小于3.52%。方法检出限为5μg/kg,定量限为15μg/kg。表明该检测方法简单、灵敏、可靠,适用于牛奶中氯唑西林残留的分析检测。     

鸡皮脂和肾脏中替米考星残留HPLC检测方法的建立

本试验旨在建立鸡皮脂和肾脏组织中替米考星残留量的HPLC测定方法。皮脂和肾脏组织中残留的替米考星用乙腈提取、MCX固相萃取柱净化,采用高效液相色谱-紫外检测法测定。皮脂组织和肾脏组织中替米考星检测限分别为20μg/kg和30μg/kg,定量限分别为35μg/kg和50μg/kg。空白皮脂组织添加替米考星在35～150μg/kg浓度水平,回收率在75%～98%之间,批内与批间变异系数均小于10%;空白肾脏组织添加替米考星在50～500μg/kg浓度水平,回收率在71%～97%之间,批内变异系数小于11%,批间变异系数小于10%。本试验建立的方法快速、准确、灵敏,适用于鸡皮脂和肾脏组织中替米考星残留量的检测。     

直接竞争ELISA检测氯霉素残留的方法建立及初步应用

用混合酸酐法合成氯霉素的CAP抗原,用过碘酸钠氧化法合成CAP酶标记抗原,用ELISA方法对合成的CAP抗原、CAP酶标记抗原进行鉴定表明其与抗CAP单克隆抗体具有特异性反应。在此基础上建立了包被二抗的直接竞争ELISA方法。特异性试验结果表明,CAP琥珀酸酯、CAP琥珀酸钠盐的交叉反应率分别为107%、106.4%;甲砜霉素、氟甲砜霉素与CAP的交叉反应率小于0.016%;与其他结构类似物间未见交叉反应。该方法对CAP的检测限可达到0.1μg/L,IC50为11.6μg/L,线性范围0.1～100μg/L,批内变异系数小于11.5%,批间变异系数小于19.6%。对猪肉、鸡肉、蜂蜜分别添加1.0、3.0、10.0、30.0μg/L CAP标准品,回收率61.0%～102.0%,变异系数为6.6%～15.8%;对猪肉、鸡肉、蜂蜜中CAP的最低检测限分别为0.48、0.42、1.20μg/kg。     

牛可食性组织中加米霉素残留量的液相色谱-串联质谱检测方法的研究

本试验建立了牛可食性组织中加米霉素残留量检测的制样和高效液相色谱-串联质谱检测方法,适用于牛组织中加米霉素残留量的测定。牛组织(牛的肌肉、肝脏、肾脏和脂肪)经绞碎、均质后,样品经0. 1 mol/L磷酸二氢钾缓冲液提取,Oasis HLB固相萃取柱净化,高效液相色谱-串联质谱法检测,内标法定量。该方法特异性好,空白样品无干扰。该方法的检测限为1μg/kg,定量限为2μg/kg,基质匹配标准曲线范围为5μg/L～500μg/L,相关系数 0. 99;牛肌肉和肾脏组织在2、50、100、200μg/kg四个添加浓度的平均回收率为93. 56%～103. 31%,批内变异系数≤8. 67%,批间变异系数≤6. 70%;牛肝脏组织在2、100、200、400μg/kg四个添加浓度的平均回收率为94. 37%～102. 52%,批内变异系数≤5. 70%,批间变异系数≤4. 61%;牛脂肪组织在2、10、20、40μg/kg四个添加浓度的平均回收率为100. 95%～105. 58%,批内变异系数≤5. 89%,批间变异系数≤4. 52%。     

UPLC-MS／MS法同时测定鸡肉中的莫能菌素和盐霉素残留

建立了同时测定鸡肉中莫能菌素和盐霉素残留检测方法。在国内外已有研究的基础上,对样品前处理和仪器条件进行了改进,采用乙腈提取鸡肉中莫能菌素和盐霉素残留,石墨化碳黑SPE小柱对提取液进行净化,然后用Waters ACQUITY UPLCTMTQD超高效液相色谱-串联质谱仪测定。结果表明,莫能菌素和盐霉素的检测限为0.2μg/kg,最低定量限为0.5μg/kg。选取0.5、1.0、2.0μg/kg三个浓度进行空白添加回收率实验,回收率为71.9%~95.1%,批内变异系数和批间变异系数均小于15%,适合大量鸡肉样品中莫能菌素和盐霉素的残留检测。     

鸡肉组织中环丙沙星残留的ELISA与HPLC检测方法比较

利用单克隆抗体间接竞争ELISA方法测定了鸡肉中环丙沙星的残留,同时利用HPLC方法进行了比较分析。间接竞争ELISA法的线性范围为6.25~400μg/L,最低检测限为4.10μg/L。HPLC法的线性范围为0.06~500μg/L,最低检测限为0.06μg/L。在标准品添加量为1.5625×10-4~1.25×10-3g/kg时,ELISA方法的平均回收率为73.81%,批内变异系数为8.75%,HPLC方法平均回收率为80.41%,批内变异系数为1.27%。结果显示,ELISA方法与HPLC方法具有很好的相关性(r2=0.9925),该ELISA方法可用于鸡肉样品中环丙沙星的检测。     

白术、微米白术和白术多糖对断奶仔猪生长性能和肠道形态及微生态区系的影响

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。     

Prevalence and seasonal incidence of nematode parasites and fluke infections of sheep and goats in eastern Ethiopia

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.     

Internal Parasites and Haematological Values in Cattle Slaughtered in Buea Subdivision of Cameroon

Tropical Animal Health and Production -     

Phase I evaluation of CCNU (lomustine) in tumor-bearing cats

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.     

Chemotaxis of macrophage in inflammation

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.     

Prevalence of gastric lesions in racing Alaskan sled dogs

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.     

Y‐chromosomal variation of local goat breeds of Turkey close to the domestication centre

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.     

Furosemide continuous rate infusion in the horse: evaluation of enhanced efficacy and reduced side effects

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.     

Changes in proportion of canine urinary calculi composed of calcium oxalate or struvite in specimens analyzed from 1981 through 2001

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.     

Feline intracranial neoplasia: retrospective review of 160 cases (1985-2001)

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.