基于飞行时间质谱法的单核细胞增生李斯特氏菌定性质控样品研制

通过真空冷冻干燥技术成功制备出单核细胞增生李斯特氏菌定性质控样品,并系统分析质控样品的均匀性和稳定性。通过优化冻干基质条件,得到制备质控样品的最佳条件。通过培养计数和基质辅助激光解吸电离飞行时间质谱技术,验证定性质控样品的均匀性和稳定性。结果表明：制备的单增李斯特菌定性质控样品为白色、质地均匀小球,均匀性验证实验质控样品培养计数结果F=0.567,小于临界值,表明均匀性一致;运输稳定性实验验证了质控样品在37、25?℃环境下含量几乎没有下降,计数稳定;贮藏稳定性实验验证了质控样品在－20?℃贮藏28?d后的复苏率为101.5%,在4?℃条件下贮藏28?d后的复苏率为99.6%,说明该样品均匀性和稳定性良好,可以作为阳性质控样品用于单增李斯特菌检测和质量控制。     

含乳特殊医学用途配方食品中沙门氏菌检测即用型质控样品研制

为评估即用型沙门氏菌质控样品在基质辅助激光解析电离飞行时间质谱技术鉴定含乳特殊医学用途配方食品中沙门氏菌中的应用价值,通过验证即用型沙门氏菌质控样品的均匀性、稳定性,对－20 ℃贮藏0、14、28 d沙门氏菌质控样品进行质谱鉴定,最后用VITEK全自动微生物分析系统进行生化鉴定。结果表明：即用型沙门氏菌质控样品稳定性良好、均匀性符合要求,所得质谱图相近,VITEK生化鉴定结果为沙门氏菌;即用型沙门氏菌质控菌株可以作为含乳特殊医学用途配方食品中沙门氏菌检测质控样品使用。     

气相色谱-质谱联用技术在乳制品检测中的应用

气相色谱-质谱联用技术是一种气相色谱和质谱有效结合的分析方法,实现了两者的优势互补,大大提高了检测结果的准确性.气相色谱-质谱联用能对样品高效分离,同时还能定性、定量,在食品质量检测和安全控制方面有很重要的作用.近几年来,气相色谱-质谱联用技术广泛应用于乳制品的分析和检测中,可用于农药残留检测、食品添加剂检测、食品成分...     

唑虫酰胺在柑橘及其土壤中残留规律及风险评估

目的 通过唑虫酰胺在柑橘及土壤中开展的两年三地的残留试验并进行风险评估,为制定唑虫酰胺在柑橘上的最大残留限量值提供数据支撑。方法 根据农药残留试验准则和标准操作规程开展田间试验,样品前处理后通过液相色谱-串联质谱测定得到试验数据,再进行风险评估。结果 唑虫酰胺在柑橘和土壤0.010~1.5 mg/kg的添加水平中,平均回收率达到90.6%~107.4%,相对标准偏差为1.5%~9.0%,定量限为0.010 mg/kg。两年三地唑虫酰胺在柑橘上的半衰期为17.3~34.7 d,土壤中的半衰期为5.8~34.7 d,末次施药后间隔21 d采集柑橘和土壤样品测定唑虫酰胺残留量均低于美国规定的最大残留限量值,不存在膳食摄入风险和急性膳食风险。结论 按照美国规定的最大残留限量值(MRL)1.5 mg/kg,间隔21 d采集的柑橘是相对安全的,唑虫酰胺的残留风险较低。     

啶虫脒和高效氯氰菊酯在柑橘上的残留行为及其膳食风险评估

为对啶虫脒和高效氯氰菊酯的残留降解和膳食风险作出科学评价。采用气相色谱检测法研究了自然条件下啶虫脒及高效氯氰菊酯在柑橘上的消解动态和最终残留情况,并据此对啶虫脒和高效氯氰菊酯在柑橘上的残留慢性膳食风险进行了评估。结果表明：啶虫脒及高效氯氰菊酯在柑橘中的消解规律符合一级动力学模型,药后21 d啶虫脒和高效氯氰菊酯其降解率均在90%以上,其半衰期分别为4.93~9.83 d、4.02~5.31 d;不同施药剂量和施药次数,末次施药后的21 d,柑橘中啶虫脒和高效氯氰菊酯的残留量均<1 mg.kg-1;取残留中值进行慢性膳食摄入风险评估,结果表明无论是老年人还是儿童其风险均在可接受范围之内。由此可见,遵循良好的农业操作规范,该农药对我国居民的膳食安全不构成威胁。     

猪尿液中盐酸克伦特罗检测方法比较

利用快速检测试纸条法、竞争酶标免疫法(ELISA)和气相色谱-质谱分析方法(GC-MS)分别对84份猪尿液样品进行盐酸克伦特罗检测。结果显示,ELISA方法与气相色谱-质谱分析方法(GC-MS)符合率为100%,快速检测试纸条法与固相萃取-气相色谱-质谱分析方法(GC-MS)符合率为90.5%。     

气相色谱-质谱法测定饲料中三聚氰胺

实验建立了气相色谱-质谱法测定饲料中三聚氰胺的方法.饲料样品经三氯乙酸提取,乙酸铅沉淀蛋白后,过HR-XC阳离子交换固相萃取小柱除去样品基质干扰,用N,O-双三甲基硅基三氟乙酰胺+三甲基氯硅烷(V∶V=99∶1)衍生,进行气相色谱-质谱分析.结果表明,三聚氰胺浓度为0.01～4.00 mg/L时,线性关系良好(r=0.9996),方法回收率为90.2％ ～ 94.8％,RSD为1.3％～4.0％,检出限为0.01 mg/kg.     

分散固相萃取-气相色谱-质谱方法快速检测奶牛饲料中的3种除草剂残留

建立了奶牛饲料样品中甲草胺、乙草胺、莠去津3种除草剂的气相色谱-质谱(GC-MS)检测方法,样品经分散固相萃取法处理后,取上清液用安捷伦HP-5气相色谱毛细管柱分离,气相色谱-质谱联用仪进行测定。3 种除草剂在 5~500 μg/kg 内线性关系良好。平均添加回收率为94.5%~115.4%,相对标准偏差(RSD) 为4.4%~9.2%,最低检测限为1.5 μg/kg。本方法前处理操作快速简单,可重复性好,满足国内外对饲料中甲草胺、乙草胺和莠去津的快速、准确的检测要求,适合大量样品的准确定量和定性分析。     

MSPD/GPC-GC-NCI/MS法测定牛肉中10种菊酯类农药残留方法的研究

采用基质分散（MSPD）、凝胶色谱（GPC）和气相色谱-负化学源质谱（NCIMS）技术建立了牛肉中10种菊酯类农药残留的提取、净化和分析方法。样品与C18/弗罗里硅土（1/2,g/g）填料混合,以乙酸乙酯-环己烷（1：1）洗脱后,经GPC净化,采用GC-NCI/MS检测。在5、10、50μg/kg加标水平下,平均回收率为78.1%-115%;相对标准偏差为1.1%-14.9%。本方法操作简单、净化效果好、灵敏度高,可用于牛肉中10种菊酯类农药残留的实际检测分析。     

液相色谱法测定饲料中9种氨基甲酸酯类农药残留

建立一种高效液相色谱柱后衍生法测定饲料中9种氨基甲酸酯类农药(涕灭威砜、灭多威、3-羟基克百威、涕灭威、速灭威、克百威、甲萘威、异丙威、仲丁威)残留量的方法。样品采用乙腈提取,氨基固相萃取柱分离净化,浓缩,乙腈定容后,进行反相色谱梯度洗脱分离、柱后衍生化、荧光检测器测定。结果表明,9种氨基甲酸酯类农药在22min内能实现基线分离,方法的回收率为80.0%～110.0%,检出限为0.01mg/kg,定量限为0.05mg/kg。     

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.     

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.     

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.     

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.     

Evaluation of biohydrogenation rate of canola vs. soya bean seeds as unsaturated fatty acids sources for ruminants in situ

An experiment was conducted to study disappearance of C14 to C18 fatty acids, lag times and biohydrogenation (BH) rates of C18 fatty acids of ground soya bean and canola seeds in situ. Three ruminally fistulated Dallagh sheep were used to determine ruminal BH of unsaturated fatty acids (UFAs). Differences in the disappearance of fatty acids through the bags and lag times were observed between the oilseeds. We saw that the longer the incubation time of the oilseeds in the rumen, the lower the content of C18:2 and C18:3. Significantly higher lag times for both C18:2 and C18:3 were observed in ground canola compared to ground soya bean. BH rates of C18:2 and C18:3 fatty acids in soya bean were three times higher than those of canola. These results suggest that the fatty acid profile of fat source can affect the BH of UFAs by rumen micro‐organisms. So that UFAs of canola had higher ability to escape from ruminal BH. It seems that fatty acid profile of ruminant products is more affected by canola seed compared to soya bean seed.     

Serum biochemical values and mineral element contents of tissues in yaks

Serum biochemical values and the wet weight to dry weight ratios of tissues were determined in yaks in Shandan county of Gansu province. The liver, kidney, heart and muscle contents of seven elements in yaks were also analysed. Most serum biochemical values were similar to those of cattle, camels and sheep, but the calcium concentration was considerably above the normal range for other ruminants. The liver contained the highest concentrations of copper, manganese and cobalt and the kidney of selenium, iron and calcium.Abbreviations Alb albumin - ALT alanine aminotransferase - AST aspartate aminotransferase - BUN blood urea nitrogen - Chol cholesterol - Glob globulin - -GT -glutamyl transpeptidase - IP inorganic phosphorus - TP total protein     

Avian brood parasitism — a growing research area in behavioral ecology (part Ⅱ)

正We are pleased to publish the second special issue on avian brood parasitism and to be responsible guest editors for the two special issues of Chinese Birds (Vol. 3, No. 4, 2012 and Vol. 4, No. 1, 2013), entitled "Avian Brood Parasitism - A Growing Research Area in Behavioral Ecology". The first issue was published in December 2012. The goal of the two special issues is to publish accumulated knowledge and some of the recent developments in     

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

Tropical Animal Health and Production -