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1.
为研究犬腺病毒(CAV)致弱疫苗的免疫原性,本研究将病犬的组织样品接种于MDCK细胞内,进行病毒分离及鉴定。鉴定结果显示,分离的病毒在MDCK细胞内产生明显的细胞病变(CPE),电镜下可见典型的腺病毒粒子;回归动物试验显示,该分离株可导致犬出现明显的CAV感染症状;PCR鉴定结果表明分离的病毒为CAV,命名为CAV-H株;将CAV-H株接种MDCK细胞连续传代至110代,在传代过程中,病毒滴度由初始105.0 TCID50/0.1 mL上升至107.0 TCID50/0.1 mL,而CAV对犬的致病力逐渐降低;免疫效力试验结果表明,CAV-H可对同源强毒攻击的犬提供完全的免疫保护作用,可作为理想的疫苗候选毒株。  相似文献   

2.
猪圆环病毒2型(PCV2)是引起断奶仔猪多系统衰竭综合征(PMWS)的主要病原,疫苗是防制该病的主要手段.为研究PCV2灭活疫苗的免疫效果,本研究将PCV2 SH株灭活,用生理盐水稀释成5×105.0TCID50/mL(高剂量)、2.5×1050 TCID50/mL(中等剂量)、1.25×105.0 TCID50/mL(低剂量)、6.3×104.0 TCID50/mL(超低剂量)4种剂量,与等量白油佐剂乳化后,通过断乳仔猪的免疫攻毒试验观察该灭活疫苗的免疫特性.结果表明,PCV2疫苗抗原含量大于1.25×105.0 TCID50/mL时免疫仔猪后均可以产生特异性抗体,能够明显减轻攻毒后仔猪的临床症状、缓解组织病变、降低病毒血症,对免疫猪有一定的保护效果,可以作为预防PCV2感染的疫苗使用.本研究为研制商品化的PCV2灭活疫苗提供实验依据.  相似文献   

3.
为研制犬细小病毒(CPV)致弱疫苗,本研究通过将犬的组织样品接种CRFK细胞进行病毒分离,并对分离毒株进行了一系列鉴定。鉴定结果显示,分离的病毒在CRFK细胞上可产生明显的细胞病变(CPE),并且电镜下可以观察到典型的细小病毒粒子;HA效价可达到1∶256。回归动物试验显示该分离株可导致犬出现明显的CPV感染症状,PCR鉴定也进一步确定所分离的病毒为CPV(命名为CPV-YN株)。将CPV-YN株接种CRFK细胞连续传代至110代,在传代过程中,病毒的滴度逐渐提高,由初始的105.5 TCID50/0.1 mL逐渐增加到107.1 TCID50/0.1 mL。同时,CPV对犬的致病力逐渐降低。免疫效力试验结果表明,CPV-YNR可以对用同源强毒攻击的犬提供免疫保护作用,可作为理想的疫苗候选病毒株。  相似文献   

4.
为检测牛传染性鼻气管炎病毒(IBRV)抗体在免疫牛体内的产生及其消长规律,评价IBRV LNM株致弱疫苗的保护效力,并确定免疫持续期,本实验对免疫试验组牛每头颈部肌肉接种制备的IBRV LNM株致弱疫苗104.5 TCID50/mL,监测血清抗体效价,进行免疫期的确定。在疫苗免疫后的6个月、9个月和12个月分别抽取3头免疫组和两头对照组牛采用IBRV-LN01/08强毒株进行攻毒试验,每头牛的攻毒剂量为107.0 TCID50/mL。结果显示疫苗免疫后12个月时,中和抗体效价仍维持在1∶11以上。攻毒结果显示3个时间点强毒攻击后,疫苗对免疫牛均具有良好的保护力。研究表明IBRV弱毒疫苗可有效地保护免疫牛抵抗IBRV强毒株的攻毒,其免疫持续期最少为12个月。  相似文献   

5.
将35头40日龄猪繁殖与呼吸综合征病毒(Porcine reproductive and respiratory syndrome virus,PRRSV)、猪瘟病毒(Classical swine fever virus,CSFV)、猪圆环病毒(Porcine circovirus type 2,PCV2)抗原及抗体均为阴性的健康仔猪,随机分成7组,每组5头,命名为XJ1~XJ7组。XJ1~XJ6组分别免疫PRRSV基因工程双标记疫苗rHN4-△25+NP49株,接种剂量分别为102TCID50/头、103TCID50/头、104TCID50/头、105TCID50/头、106TCID50/头和107TCID50/头,XJ7组为对照组,按1mL/头剂量接种DMEM。各试验组在免疫后28 d,用3×104.0TCID50/头剂量感染HP-PRRSV HuN4第5代强毒,疫苗免疫和攻毒后观察和检测各组试验猪的免疫效果。结果表明:攻毒前XJ2-XJ6组PRRSV ELISA抗体在免疫后14 d全部转为阳性,XJ1组在免疫后21 d转为阳性,但维持在较低水平;XJ2-XJ6组针对标记基因NP49的特异性抗体在免疫后28 d转阳性。攻毒后对照组全部发病,且死亡2头,XJ1有4头发病,XJ2-XJ6组无发病和死亡,本研究结果表明PRRSV基因工程双标记疫苗rHN4-△25+NP49株对仔猪提供免疫保护的最小免疫剂量为103TCID50/头。  相似文献   

6.
将重组腺病毒rAd-H5HA-EGFP以不同免疫剂量接种BALB/c小鼠,通过检测小鼠免疫后的抗体以及抵抗H5N1亚型流感病毒攻击的保护对rAd-H5HA-EGFP的免疫保护性进行了评估。分别以108 TCID50、107 TCID50的rAd5-H5HA-EGFP免疫小鼠,初次免疫后3周进行加强,剂量为2×108 TCID50和2×107 TCID50,同时以接种rAd5-EGFP和PBS的小鼠作为对照。二免后3周,将各组试验小鼠随机分为2组,分别应用106 EID50的SW/FJ/1/01株和CK/HuN/77/05两株H5N1亚型流感病毒进行攻击。结果显示,重组病毒108 TCID50和107 TCID50的免疫剂量均能够诱导高水平的HI抗体生成,rAd-H5HA-EGFP免疫小鼠在受到病毒SW/FJ/1/01和CK/HuN/77/05攻击后,与接种腺病毒rAd-EGFP和PBS的对照组小鼠相比,没有出现明显的体质量减轻,攻毒后病毒在免疫小鼠体内的复制被完全或部分抑制,脏器内检测到的病毒含量明显低于对照组小鼠;免疫小鼠在受到CK/HuN/77/05毒株攻击时,没有出现死亡(0/5),而接种rAd-EGF...  相似文献   

7.
为了研制猪2型圆环病毒（PCV2）基因工程疫苗,以伪狂犬病病毒（PRV）基因缺失疫苗株SA215为病毒载体,通过同源重组,构建了共表达PCV2ORF2基因和绿色荧光蛋白基因重组伪狂犬病病毒SA215（C）株。经PCR、Southern blotting、Western blotting等证实SA215（C）构建正确,并能表达具有活性的ORF2基因蛋白和荧光蛋白。SA215（C）在IBRS-2、ST细胞中的增殖滴度与亲本株SA215相比无显著差异,表明外源基因的插入不影响病毒增殖。用SA215（C）免疫BALB/c小鼠10周后检测免疫小鼠PCV2抗体和PRV中和抗体及细胞免疫反应。结果显示,SA215（C）诱导小鼠产生了PCV2和PRV抗体并出现PCV2的细胞免疫反应。另外,以105TCID50的SA215（C）株接种BALB/c小鼠,接种后28d再接种1次,2次接种后2周,用107TCID50PRVFa和PCV2强毒联合进行攻击,结果免疫小鼠抵抗住强毒的攻击,获得了保护;表明该毒株具有很强的免疫原性,为研制安全、有效的PCV2-PRV二价基因工程疫苗奠定了基础。  相似文献   

8.
为研制牛传染性鼻气管炎病毒(IBRV)灭活疫苗,本研究以国内分离鉴定的IBRV LN01/08株为种毒,优化病毒增殖条件,获得病毒滴度达108.0TCID50/mL,将其灭活制备疫苗.为比较不同免疫佐剂的效果,分别以矿物质白油和Montanide ISA206佐剂配制灭活疫苗,进行牛体免疫试验.临床观察和血清中和抗体检测结果表明,Montanide ISA206佐剂乳化的疫苗在降低副反应和增强免疫效果方面优于矿物质白油佐剂.应用Montanide ISA206佐剂制备3批灭活疫苗,并对其安全性和免疫保护效果进行测定.结果表明该疫苗安全可靠,对强毒攻击可产生较好的抵抗力,攻毒保护率达80%.疫苗在2℃～8℃保存12个月后仍能保持良好的免疫效果.  相似文献   

9.
《中国兽医学报》2017,(1):11-17
探索重组PPV VP2基因的猪伪狂犬病病毒rPRV-VP2株作为弱毒疫苗候选株的潜在价值,对其在多种细胞上的增殖特性、病毒滴度、最适培养细胞中的遗传稳定性、一步生长曲线、转录和翻译水平等生物学特性进行研究,并初步探索对小鼠安全性。结果显示:重组病毒rPRV-VP2株在VERO、ST、PK-15和IPEC细胞上的TCID50分别为104.375/0.1mL、106.5/0.1mL、103.75/0.1mL、105.625/0.1mL。重组毒与亲本毒PRV HB-98株在ST细胞中的毒力(106.125 TCID50/0.1mL)和细胞病变相当,重组病毒保持了PRV病毒的通性。连续传毒20代后的绿色荧光观察、RTPCR、Western blot试验结果均表明重组病毒中的VP2基因得到了有效表达,且遗传稳定性良好。安全性试验结果显示:重组毒对小鼠安全。本试验为后期对PPV VP2基因重组猪伪狂犬病毒rPRV-VP2株的开发利用奠定了基础。  相似文献   

10.
对PrV Ea TK^-/gE^-/gI^-基因缺失疫苗的安全性和保护力进行了系统的研究。试验表明，该基因缺失疫苗10^5.0TCID50和10^6.0TCID50病毒剂量对妊娠母猪、新生仔猪和育肥猪均是安全的，并可保护妊娠母猪抵抗10^7.1 TCID50强毒的攻击。新生仔猪免疫30d后，gE鉴刖ELISA试验表明，PrV Ea TK^-/gE^-/gI^-免疫猪不产生针对gE的抗体。育肥猪在二次免疫后中和抗体水平显著升高。以10^5.0 TCID50和10^6.0 TCID50疫苗病毒接种家兔、猫和奶山羊等非靶动物，结果非靶动物未出现精神异常或死亡现象，说明该基因缺失疫苗具有极高的生物安全性。  相似文献   

11.
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   

12.
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   

13.
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   

14.
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   

15.
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   

16.
Comparison of different tests to diagnose feline infectious peritonitis   总被引：1，自引：0，他引：1  
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17.
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.  相似文献   

18.
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  相似文献   

19.
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  相似文献   

20.
Tropical Animal Health and Production -  相似文献   

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