银杏叶提取物抑制鸡新城疫病毒增殖试验

进行了银杏叶提取物对1O日龄鸡胚人工感染新城疫病毒(NDV)的抑制试验.抑制NDV增殖试验结果表明,NDV强毒组在48h的鸡胚保护率为20%,0.500 g/mL银杏叶提取物+NDV组鸡胚保护率为50%,两者差异显著(P<0.05);0.250 g/mL+NDV组、0.125 g/mE+NDV组的鸡胚保护率分别为70%、80%,与强毒组相比,差异显著(P相似文献   

中药牛皮消多糖体外抗新城疫病毒作用的研究

为探讨牛皮消多糖(CAP)对体外抗新城疫病毒(NDV)能力的影响,本试验用水提醇沉法提取牛皮消多糖,通过苯酚硫酸法和红外光谱对牛皮消多糖进行检测,采用MTT法测定牛皮消多糖对鸡胚成纤维细胞(CEF)的安全浓度,多糖的安全浓度统一为625μg/mL,选择安全浓度范围内的(39.06～625μg/mL)5种浓度的各级多糖,用3种加药方式(先加多糖后接种病毒、先接种病毒后加多糖、多糖和病毒感作后加药)检测牛皮消多糖对NDV的阻断、抑制及直接杀灭作用。结果显示,先接病毒后加多糖组和多糖与病毒感作后加药组CAP_(50)、CAP_(30)、CAP_t、CAP_(80)和CAP_(70)均能显著抑制NDV感染CEF的能力,两组各级多糖抑制率分别为131.23%、110.12%、108.15%、100.24%、93.07%和61.76%、43.73%、44.51%、29.02%、37.45%;先加多糖后接病毒组CAP_(50)、CAP_(30)能显著抑制NDV感染CEF的作用(P0.05),阻断作用下对NDV的抑制率可达到15.82%、8.33%,其余各组在安全浓度范围内对NDV无抑制作用。各组中药牛皮消多糖均有较好的抗NDV活性,其中对NDV的抑制作用和直接杀灭作用强于对其阻断作用。CAP_(50)及CAP_(30)的抗NDV活性较强,可作为进一步研究材料并具备一定的研究价值。     

病毒样颗粒疫苗可能用于控制鸡新城疫

正韩国建国大学的科研人员应用昆虫细胞表达系统研制出表达新城疫病毒(NDV)F蛋白和流感病毒M1蛋白的NDV病毒样颗粒(VLP)。SPF鸡分别免疫含不同剂量VLP(0.8、4、20、100μg/mL)的NDV VLP油乳剂疫苗。免疫3周后,应用商品化ELISA试剂盒检测NDV VLP疫苗的免疫力;同时用NDV强毒株进行攻毒试验以评估NDV VLP疫苗对SPF鸡的保护效果。结果显示,NDV VLP疫苗免疫后可产生大量抗NDV的抗体,且SPF鸡对NDV强毒株的抵抗力与NDV VLP疫苗免疫剂量相关。尽管含0.8、4μg/mL VLP的NDV VLP疫苗不能     

藏药"十三味红花丸"对NDV的抑制试验研究

本试验选用10日龄SPF鸡胚,对藏药“十三味红花丸”进行了人工感染NDV的抑制试验研究,试验结果显示,藏药药液（1g/mL)用2倍、4倍和6倍稀释,对鸡胚感染NDV的保护率分别达100％、90％和80％,比NDV强毒对照组分别提高80、70和60个百分点,NDV强毒接种鸡胚囊液NDV血凝效价明显高于NDV强毒＋藏药药液鸡胚尿囊液NDV血凝效价。试验结果表明,藏药“十三味红花丸”对NDV具有很强的抑制作用。     

藏药“十三味红花丸”对鸡新城疫病毒鸡胚复制抑制试验

选用 10日龄SPF鸡胚 ,对藏药“十三味红花丸”进行了人工感染鸡新城疫病毒 (NDV)的抑制试验。结果显示 :藏药药液 ( 1g/mL)用 2倍、 4倍和 6倍稀释 ,对鸡胚感染NDV的保护率分别达 10 0 %、 90 %和 80 % ,比NDV强毒对照组分别提高 80、 70和 6 0个百分点。NDV强毒接种组的鸡胚尿囊液NDV血凝效价明显高于NDV强毒 +藏药药液组的鸡胚尿囊液NDV血凝效价     

荷叶总碱体外抗新城疫病毒活性研究

采用纯化的荷叶总碱进行体外抗新城疫病毒(NDV)活性研究,测定了其对鸡胚成纤维细胞的最大无毒浓度(TD0)、半数中毒浓度(TD50)、抑制50%细胞病变的药物浓度(IC50)和治疗指数(TI)。结果表明:荷叶总碱具有明显的抗NDV作用,其TD0、TD50、IC50和TI分别为6.25mg/mL、13.86mg/mL、1.53mg/mL和9。     

葫芦多糖体外抗鸡新城疫病毒作用的研究

为研究葫芦多糖抗新城疫病毒（Newcastle disease virus,NDV） 活性,本试验采用水提醇沉法提取葫芦总多糖及4种分级多糖,通过苯酚-硫酸法及红外光谱对葫芦多糖进行检测,MTT法测定各级多糖对鸡胚成纤维细胞（CEF）的安全浓度,多糖的安全浓度统一定为78.125 μg/mL,以3种加药方式（先加多糖后接种病毒、先接种病毒后加多糖、多糖和病毒感作后加药）,检测葫芦多糖对NDV的阻断、抑制及直接杀灭作用。结果表明,葫芦总多糖及4种分级多糖均具有抗NDV活性,其中对NDV的抑制作用及直接杀灭作用强于对NDV的阻断作用。70%、80%梯度醇沉的葫芦多糖（LSP₇₀、LSP₈₀）及总多糖（LSP_t）,抑制作用下的病毒抑制率分别为40.41%、44.54%、61.85%,杀灭作用下的病毒抑制率分别为44.74%、58.76%和59.38%,阻断作用下对NDV的抑制率,其中LSP₈₀组最高达37.14%,其余各组均低于25%。综上可知,70%、80%梯度醇沉的葫芦多糖及葫芦总多糖的抗NDV活性较好,可作为进一步研究的材料。     

复方中药禽康散对接种新城疫病毒鸡胚的保护效应

为了研究复方中药禽康散提取液对鸡新城疫病毒活性的影响,试验采用鸡胚法以不同浓度中药提取液与新城疫F48E9毒株悬液混合后各接种8枚鸡胚,观察各组鸡胚的存活情况。结果表明:中药浓度为1.0 g/mL、0.5 g/mL、0.25 g/mL时活胚率分别是87.5%、75.0%、50.0%,而不加中药组鸡胚96 h后全部死亡。说明复方中药禽康散具有抗新城疫F48E9毒株的作用,且随着中药浓度的增加抗病毒作用增强,呈现一定的量效关系。     

氨苄青霉素-硫氰酸红霉素可溶性粉对鸡毒支原体病的治疗试验

利用氨苄青霉素—硫氰酸红霉素可溶性粉剂进行了鸡毒支原体体外抑菌试验和体内治疗试验：体外抑菌试验结果表明：当培养基中药物浓度达到0．0125μg/mL时，便能有效地抑制试管中鸡毒支原体的生长繁殖：体内治疗试验结果表明：当饮水中药物浓度达到20μg/mL时，便能有效地降低感染鸡的死亡率，对提高感染鸡的增重有一定的作用，但在降低气囊损伤方面作用不明显，所有感染鸡体内抗体检测均为阳性：除在提高感染雏鸡成活率方面稍优于强力米先外，其他方面二者作用基本相当。     

中药牛皮消多糖体外抗新城疫病毒作用的研究

为探讨牛皮消多糖（CAP）对体外抗新城疫病毒（NDV）能力的影响，本试验用水提醇沉法提取牛皮消多糖，通过苯酚硫酸法和红外光谱对牛皮消多糖进行检测，采用MTT法测定牛皮消多糖对鸡胚成纤维细胞（CEF）的安全浓度，多糖的安全浓度统一为625 μg/mL，选择安全浓度范围内的（39.06~625 μg/mL）5种浓度的各级多糖，用3种加药方式（先加多糖后接种病毒、先接种病毒后加多糖、多糖和病毒感作后加药）检测牛皮消多糖对NDV的阻断、抑制及直接杀灭作用。结果显示，先接病毒后加多糖组和多糖与病毒感作后加药组CAP₅₀、CAP₃₀、CAP_t、CAP₈₀和CAP₇₀均能显著抑制NDV感染CEF的能力，两组各级多糖抑制率分别为131.23%、110.12%、108.15%、100.24%、93.07%和61.76%、43.73%、44.51%、29.02%、37.45%；先加多糖后接病毒组CAP₅₀、CAP₃₀能显著抑制NDV感染CEF的作用（P<0.05），阻断作用下对NDV的抑制率可达到15.82%、8.33%，其余各组在安全浓度范围内对NDV无抑制作用。各组中药牛皮消多糖均有较好的抗NDV活性，其中对NDV的抑制作用和直接杀灭作用强于对其阻断作用。CAP₅₀及CAP₃₀的抗NDV活性较强，可作为进一步研究材料并具备一定的研究价值。     

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.     

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     

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

Tropical Animal Health and Production -     

Evaluation of the Microbiological Status of Milk and Various Structures in Mammary Glands from Naturally Infected Dairy Cows

A knowledge of the microbiological status of milk and of the different structures in the mammary glands has great importance in elucidating the pathogenesis of mammary gland infections. The objective of this study was to evaluate the microbiological status of various structures in the mammary glands from naturally infected dairy cows following slaughter. A total of 94 samples of milk, 184 samples of mammary parenchyma, 168 samples of gland cisterns, and 168 samples of teat cisterns were collected for microbiological examination. Microorganisms were detected in 59.9% of all samples, 67.0% of the milk samples, 70.1% of the mammary parenchymas, 55.9% of the gland cisterns and 48.8% of the teat cistern samples. When all samples were considered, coagulase-negative Staphylococcus were the most prevalent (35.7%) followed by coagulase-positive Staphylococcus (12.2%), Corynebacterium bovis (2.4%), Prototheca sp. (1.9%), and Streptococcus dysgalactiae (1.5%). There was a significantly higher occurrence of microorganisms in the milk and mammary parenchyma compared to the gland cisterns and teat cisterns. This revised version was published online in July 2006 with corrections to the Cover Date.     

Development and survival of free-living stages of gastrointestinal nematodes of sheep and goats on pasture in the Nigerian derived savanna

Four grass plots were sequentially contaminated with goat faeces containing known numbers of unembryonated eggs of predominantly Haemonchus contortus and Trichostrongylus spp. between October 1982 and April 1983. Four other plots were similarly contaminated with sheep faeces between February and May 1987. An additional plot was repeatedly contaminated with sheep faeces from February to April 1987. Populations of free-living stages in faeces and of infective larvae (L₃) in the herbage were subsequently monitored until the end of April and June of 1983 and 1987 respectively. During February and May 1987 two control cultures of sheep faeces were incubated in the laboratory at 25°C–30°C and at a constant temperature of 50°C and the free-living development was also monitored. L₃ developed very readily in the faeces cultured at 25°C–30°C and in those spread on a grass plot in October, at the end of the wet season, but developed less on the plot contaminated in May at the start of the wet season. Worm eggs in faeces deposited on plots during the hot dry season (December to April) or incubated at 50°C died and disintegrated after 24–48 h exposure to the high environmental temperatures. The results indicate that it is unlikely that gastrointestinal nematodes of sheep and goats can develop or survive on open pasture during the dry season in the Nigerian derived savanna zone.