羊传染性脓疱病毒耐热冻干保护剂筛选及冻干曲线优化

采用冻干试验筛选出保护剂基础配方,再通过Plackett-Burman设计法筛选主要保护剂基质,然后通过Box-Behnken响应面分析法对羊传染性脓疱病毒(ORFV)耐热保护剂配方进一步优化,用冻干试验进一步验证筛选出1种针对ORFV保护效果最好的耐热冻干保护剂作为疫苗用候选配方。同时,依据前期试验获得的活疫苗冻干曲线,通过进一步优化,获得疫苗最佳冻干曲线。利用该冻干工艺冻干的疫苗,保护剂的保护率可达95.3%,且疫苗各项指标均达到《中华人民共和国兽用生物制品规程》要求。经37℃保存7,15,30d病毒滴度分别下降0.46,0.70,1.00;2~8℃保存3,6,12,24个月病毒滴度分别下降0.10,0.10,0.40,0.60,证明此配方制备的疫苗具有良好的热稳定性。本试验解决了ORFV细胞弱毒疫苗仅能在低温条件下保存和运输的瓶颈技术问题,使疫苗的储存、运输更为方便。     

鸡新城疫、传染性支气管炎二联活疫苗耐热保护剂筛选和优化

应用冻干制品加速热稳定试验,测试7组冻干保护剂配方对鸡新城疫、传染性支气管炎二联活疫苗（LaSota株＋H120株）的耐热保护效果。试验筛选出用于鸡新城疫、传染性支气管炎二联活疫苗的耐热保护剂,使用该保护剂的疫苗表现为37℃保存10d,病毒含量下降0．4个滴度,常规疫苗下降2～2．4个滴度;25℃保存30d,病毒含量下降0．4～0．6个滴度,常规疫苗下降1．8～2．6个滴度。证明此保护剂具有良好的耐热效果。     

鸡传染性支气管炎活疫苗耐热保护剂的研究

应用冻干制品加速热稳定性试验,测试三组冻干保护剂配方对鸡传染性支气管炎(H120株)活疫苗的耐热保护效果。结果表明A配方的耐热保护剂效果最好,使用该保护剂的疫苗表现为37℃放置10d后,病毒含量下降在0.6~0.8个滴度。     

猪繁殖与呼吸综合征活疫苗耐热冻干保护剂的研究

为了解耐热冻干保护剂在猪繁殖与呼吸综合征活疫苗中的应用效果,将高致病性猪繁殖与呼吸综合征病毒(PPRSV)分别与耐热冻干保护剂和常规冻干保护剂进行配比、冻干,制备疫苗,分别将疫苗置2~8℃保存,定期测定其效价,同时进行37℃、25℃耐老化试验。结果显示,疫苗在2~8℃条件下保存24个月,耐热苗效价下降不超过0.5个滴度,常规苗效价下降超过3.0个滴度;37℃保存10d,耐热苗效价下降不超过0.5个滴度,常规疫苗下降超过2个滴度;25℃常温保存2个月,耐热保护剂疫苗效价下降不超过0.35个滴度,而常规苗效价下降超过2个滴度。试验结果表明,耐热冻干保护剂对病毒的保护效果明显优于常规冻干保护剂,具有良好的热稳定性。     

猪瘟无明胶无蛋白耐热活疫苗的研制及冻干工艺

为提高猪瘟(CSF)活疫苗的耐热性能,同时避免明胶和蛋白对猪只产生的免疫副反应,用葡聚糖、聚乙烯吡咯烷酮、乳糖、氨基酸等成分设计无明胶无蛋白耐热保护剂,根据配方的共晶点、塌陷温度科学设计冻干程序,并比较了不同预冻方式对猪瘟活疫苗效价的影响。结果表明,猪瘟病毒采用无明胶无蛋白耐热保护剂配方A冻干后具有较好的耐热性能,37℃保存10,15d,病毒的耐热损失分别为0.6lg和0.9lg;对快冻、慢冻以及退火3种不同的冻干方式进行比较,发现对猪瘟病毒冻干损失由大到小依次为:退火慢冻快冻,而耐热损失则相反;与传统的含明胶含蛋白耐热疫苗相比,猪瘟无明胶无蛋白耐热疫苗耐热效果更好,可在2~8℃长期保存30个月,动物试验表明该疫苗对猪只安全、无副反应。     

羊传染性脓疱皮炎弱毒苗耐热保护剂初步优化筛选试验研究

试验以羊传染性脓疱皮炎弱毒活疫苗为对象,依据冻干保护剂的保护功能,对耐热保护剂的组成、混合比例进行了初步筛选。通过反复试验,对其物理性状观察、水分含量测定、冻干前后病毒损失量、经37℃处理、25℃保存后病毒损失量等指标的比较进行筛选,优选出了符合要求的A3、A6、C4三个耐热保护剂配方。试验结果表明,使用保护剂的羊口疮疫苗在37℃保存20 d,病毒含量下降0.5~0.7个滴度,常规疫苗下降2.3个滴度;25℃保存60d,病毒含量下降0.3~0.6个滴度,常规疫苗下降2.5个滴度。从而证明了羊orf耐热活疫苗耐热效果优于常规疫苗。     

动物用冻干疫苗耐热保护剂研制成功

在我国动物用冻干疫苗，多年来必须在～１５℃以下条件保存，这对于疫苗的生产、运输保存及使用等带来诸多困难。黑龙江省生物制品一厂研究所张云浦高级兽医师主持的黑龙江省科委下达的《动物用冻干疫苗耐热保护剂的研究》课题历经三年多的研究，采取多个配方，多种组合，不同配比，分别对不同种类的动物疫苗，进行了大量的试验研究。完成了鸡传染性法氏囊，鸡传染性支气管炎，鸡传染性喉气管炎，鸡痘等多种冻干活疫苗的耐热保护剂，所配制的动物疫苗，在２℃－８℃条件保存两年以上，其疫苗效价稳定和对动物免疫效果均达国外同类疫苗的水平…     

动物用冻干疫苗耐热保护剂研制成功

在我国动物用冻干疫苗，多年来必须在－１５℃以下条件保存，这对于疫苗的生产、运输保存及使用等带来诸多困难。黑龙江省生物制品一厂研究所张云浦高级兽医师主持的黑龙江省科委下达的《动物用冻干疫苗耐热保护剂的研究》课题历经三年多的研究，采取多个配方、多种组合、不同配比，分别对不同种类的动物疫苗进行了大量的试验研究。完成了鸡传染性法氏羹，鸡传染性支气管炎，鸡传染性喉气管炎，鸡痘等多种冻干活疫苗的耐热保护剂，所配制的动物疫苗，在２℃－８℃条件下保存两年以上，其疫苗效价稳定和对动物免疫效果均达国外同类疫苗的水平…     

耐热冻干保护挤及其在兽用冻干活疫苗中的应用

耐热冻干保护剂的组成和配方对冻干活疫苗的质量起着重要作用。本文对耐热冻干保护剂的种类与组成和在兽用冻干活疫苗中的应用进行了介绍。     

耐热冻干保护剂在兽用冻干活疫苗中的初步研究

耐热冻干保护剂在兽用冻干活疫苗中的研究和应用是当前国内兽用生物制品行业的一个热门话题。耐热冻干保护剂的配制及冻干充分考虑了活疫苗在较高温度和较长保存时间情况下，冻干物质可能发生的物理和化学变化对疫苗存活的影响，因而其保护性能（尤其在较高温度环境里）要比传统保护剂更为优良，使活疫苗在储存、运输、使用等方面更方便，更经济。     

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