鸡蛋及牛奶中四环素类药物残留量的液相色谱-串联质谱测定法

建立了一种测定鸡蛋及牛奶中四环素类药物残留 液相色谱-串联质谱的方法。样品经Mcllvaine-Na2EDTA缓冲液提取,经快速滤纸过滤,并经加脱脂棉的HLB固相萃取柱净化,洗脱液氮气吹至小于1 mL,加30%甲醇至1mL并混匀,液相色谱-串联质谱法检测,基质匹配标液外标法定量。结果表明,四环素类药物在5 μg/kg~100 μg/kg的浓度范围内呈现良好的线性关系。在鸡蛋及牛奶中四环素类药物的检测限均为2 μg/kg,定量限均为5 μg/kg。在LOQ~2MRL(多西环素为LOQ-10LOQ)添加浓度范围内,四环素类药物的回收率均在81.2~110.0%之间,批内批间变异系数均小于11.4%。该方法各项技术指标均能满足残留检测要求,且方法的重现性良好,满足国内外兽药残留检测的相关规定。     

UPLC-MS/MS快速测定鸡肉中的金刚烷胺和氟喹诺酮类药物残留

建立了鸡肉中金刚烷胺和8种氟喹诺酮类药物的超高效液相色谱串联质谱的测定方法。鸡肉样品经QuEChERS萃取剂提取,QuEChERS净化剂净化后,经氮气流吹干浓缩后,以超高效液相色谱串联质谱测定,稳定同位素内标法定量。本方法对金刚烷胺的测定线性范围为0.2~10.0 ?g/kg。在0.2、1.0、10.0 ?g/kg三个浓度的回收率为80~120 %。本方法对氟喹诺酮类药物的测定线性范围为2~100 ?g/kg。在2、10、100 ?g/kg三个浓度的回收率为80~120 %。批内、批间精密度小于20 %。本方法简便、快速、灵敏,适用于鸡肉中金刚烷胺和氟喹诺酮类药物残留的大批量筛选和定量测定。     

超高效液相色谱-串联质谱法测定水产品中群勃龙残留方法研究

建立了牛奶中苯并咪唑类药物及代谢物残留的超高效液相色谱-串联质谱检测方法。水产样品经乙酸乙酯提取,C18固相萃取柱净化,采用超高效液相色谱-串联质谱多反应监测模式检测,外标法定量。不同基质中,群勃龙在2-100 ng/mL的浓度范围内呈现良好的线性相关,相关系数为0.994以上;本方法对群勃龙群勃龙在鱼、虾、鳖、蟹类产品中的检测限为0.5μg/kg,定量限为1μg/kg;在贝类产品中的检测限为1μg/kg,定量限2μg/kg;不同水产品的基质中添加1-10μg/kg浓度范围内,其回收率为74.2%-119%,批内变异系数在1.0%-9.0%之间,批间变异系数在0.3%-8.5%之间。本方法分析速度快,灵敏度高,重现性好,各项技术指标均满足国内外相关法规要求,可用于水产品中群勃龙的残留检测。     

超高效液相色谱-串联质谱法测定鸡蛋中四环素类、喹诺酮类、磺胺类残留量

建立了超高效液相色谱-串联质谱法，测定了鸡蛋中四环素类、喹诺酮类、磺胺类11种抗生素残留量。采用1%酸化乙腈溶液提取，应用超高效液相色谱-串联质谱仪检测，定量方法采用外标法。鸡蛋中上述11种药物在5～100ng/mL的浓度范围内呈现良好的线性关系，鸡蛋中的检测限为1.0μg/kg，定量限为2.0μg/kg，在1.0～50μg/kg添加浓度范围内的回收率为70.2%～90.2%，批内与批间RSD值均<7.9%。     

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。     

高效液相色谱法测定鸡蛋中氟喹诺酮类药物残留量前处理方法的优化

建立了鸡蛋中环丙沙星、达氟沙星、恩诺沙星和沙拉沙星4种氟喹诺酮类药物残留测定的超高效液相色谱方法。样品经磷酸盐缓冲液提取后,用正己烷脱脂,C18固相萃取柱净化,反相高效液相色谱分离,荧光检测器测定。本方法的检测限为环丙沙星、恩诺沙星和沙拉沙星5 μg/kg,达氟沙星1 μg/kg。环丙沙星、恩诺沙星和沙拉沙星在2~200 ng/mL、达氟沙星在0.4～40 ng/mL范围内呈线性相关,相关系数r大于0.9999。在空白鸡蛋中添加环丙沙星、恩诺沙星和沙拉沙星5~50 μg/kg、达氟沙星1～10 μg/kg,4种氟喹诺酮类药物的平均回收率为82.2～101.3％,批内变异系数0.8～5.9％之间(n＝6),批间变异系数在1.0～6.6％之间(n＝4)。结果表明,该法灵敏、准确、特异性强,适用于鸡蛋中氟喹诺酮类药物残留的测定。     

超高效液相色谱-串联质谱法测定牛奶中的赛拉嗪残留

采用乙腈提取,HLB固相萃取柱净化、超高效液相色谱-串联质谱测定,建立了一种简单、快速的牛奶中赛拉嗪残留的检测方法.对样品的提取、净化过程进行了优化改进,经ACQUITY UPLCTM BEH C18色谱柱分离,正离子电喷雾电离串联质谱测定,牛奶中赛拉嗪的检测限为0.2 μg/kg,定量限为0.5μg/kg.选取0.5...     

液相色谱-串联质谱法检测牛奶中林可胺类与大环内酯类药物

牛奶食品中林可胺类药物残留可引起肾功能障碍和革兰氏阳性菌的耐药性增加;大环内酯类药物残留可引起过敏反应和导致携带耐药因子的菌株扩散。本试验利用液相色谱-串联质谱法检测牛奶中林可胺类与大环内酯类药物残留。牛奶样品中的残留药物用乙腈提取后,用正己烷去除脂肪等杂质,浓缩后供液相色谱-串联质谱法测定。经试验:系列浓度范围内呈现良好的线性关系,相关系数(R2)均大于0.990,方法的回收率为70%~120%,批内、批间相对标准偏差均小于20%。检测限为1μg/kg,定量限为2.5μg/kg。     

液相色谱-串联质谱法测定蜂产品中20种喹诺酮类药物的残留量

建立了同时测定蜂蜜和蜂王浆中20种喹诺酮类药物的超高效液相色谱-串联质谱方法。以磷酸盐缓冲液(p H 3.0)溶液提取样品中的待测物,HLB固相萃取柱净化,液相色谱-串联质谱法测定,外标法定量。药物在1~50 ng/m L浓度范围内线性关系良好,相关系数均大于0.99。方法的检出限为0.5μg/kg,定量限为1.0μg/kg,在蜂蜜和蜂王浆中添加浓度范围为1.0~5.0μg/kg,其平均回收率为69.0%~105.1%,相对标准偏差在1.4%~14.7%之间。方法抗干扰能力强、分析速度快、灵敏度高,适用于蜂产品中喹诺酮类药物残留量的测定。     

超高效液相色谱-串联质谱法同时测定饲料中的喹诺酮类和四环素类药物含量

为建立同时测定饲料中5种喹诺酮类和4种四环素类药物含量的超高效液相色谱-串联质谱（UPLC/MS/MS）分析方法,本实验采用1%甲酸甲醇溶液作为样品的提取溶液,经HLB固相萃取柱净化后上机测定。在正离子模式下通过两对离子对进行定性和定量分析,基质匹配标准溶液外标法校准。结果显示：各药物浓度在2.5 ～ 50 μg/L内线性关系良好,相关系数r均大于0.995|空白饲料添加浓度为0.05、0.1、0.25 mg/kg时,回收率为74.7% ～ 93.2%|批内、批间相对偏差（RSD）均小于15%|本方法对饲料中喹诺酮类和四环素类药物的定量限为0.05 mg/kg（S/N＞10）,检测限为0.025 mg/kg（S/N＞3）。 [关键词] 喹诺酮类|四环素类|饲料|超高效液相色谱-串联质谱     

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.     

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.     

The Epidemiology of Gastrointestinal Nematodes of Dairy Cattle in Central Kenya

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.     

Diversity of Ectoparasites in Sheep Flocks in Sa~o Paulo,Brazil

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.