牛肉孢子虫病研究：流行病学调查与病原种类研究

本文报告1986——1988年对贵州省五地区十个县(市)耕牛肉孢子虫病调查,共剖检水牛155头和黄牛195头。调查肉孢子虫感染情况;对几种住肉孢子虫进行形态观察、测量大小和动物感染试验。结果表明:贵州耕牛住肉孢子虫共有三种,总感染率为89.4%。寄生于水牛的住肉孢子虫有两种,Ⅰ、梭形住肉孢子虫 sarcocystisfusiformis,感染率100%,终宿主为猫,Ⅱ、小型住肉孢子虫 sarcocystis sp,感染率83.9%(与梭形住肉孢子虫混合感染);终宿主为狗。Ⅲ、黄牛一种;枯氏住肉孢子虫 sarcocystis cruzi,感染率81%,终宿主为狗。三种住肉孢子虫以梭形住肉孢子虫感染最严重。患牛全身布满包囊,病变明显而销毁和高温处理的占3.9%。各种感染程度分别为:轻度占62%,中度占24%,严重占14%。包囊在牛体内的分布以食道最多,为100%,颈肌次之,为73.5%,舌肌和背肌均为40%,心肌未见有此种包囊。三种住肉孢子虫以梭形住肉孢子虫的包囊最大,平均9×3.5毫米,孢子囊较小,平均13.4×7.8微米,慢殖子平均14.4×5.5微米。小型住肉孢子虫和枯氏住肉孢子虫两者相似,包囊细小,大小分别为1.6×0.17毫米和2×0.16毫米.慢殖子大小为13.8×6.7微米和13.87×4.93微米,孢子囊大小为15.81×10.33微米和15.75×10.22微米。猫感染梭形住肉孢子虫排囊前期6—7天,排囊持续2—22天,狗感染小型住肉孢子虫排囊前期为8天,持续1—20天;狗感染枯氏住肉孢子虫排囊前期为10天,持续1—10天。兔感染各种住肉孢子虫均未获得成功。对本病的防治方法文内提出讨论建议。     

水牛梭形住肉孢子虫抗原的制备及反应原性研究

将制备的水牛梭形住肉孢子虫包囊抗原及缓殖子抗原，应用血清学试验鉴定了其反应原性。结果表明，水牛梭形住肉孢子虫包囊抗原，缓殖子抗原与自然感染病牛剖检的阳性吻合率分别为５６％和７１％；水牛梭形住肉孢子虫与黄牛枯氏住肉孢子虫之间有共同抗原成份。     

青海省西宁市屠宰性畜住肉孢子虫病的调查

本文报道了西宁市屠宰场中猪、牦牛和绵羊胴体住肉孢子虫的感染情况，采用病原学调查方法，检查绵羊５１１只，牦牛２０９头，猪５１２头，住肉孢子虫感染率分别为７３．５８％、６３．６４％、５１．１７％。经测量，牦牛住肉孢子虫为８８０．１０±６６５８．８２μｍ× ９８．２１±５３．２０μｍ，猪住肉孢子虫为６６５．１５±３４９．４３μｍ×１３３．６０±３５．９８μｍ，绵羊住肉孢子虫为５０３．７５±４１２．４４μｍ×７９．６９±４５．７８μｍ。结果表明，青海家畜存在住肉孢子虫病的严重流行，威胁着人群的健康。     

猪囊虫和肉孢子虫同时寄生病猪一例

２０００年１０月１１日，我们在生猪定点屠宰宰后检疫中，检出一例罕见的猪囊虫和肉孢子同时寄生的病猪，现介绍如下：１品种来源该猪来源于安徽省怀远县万福镇。地方杂种老母猪，肉尸重 １７５ ｋｇ，中等膘情。２虫体形态特征剖检视猪囊虫和肉孢子虫在肌肉中交错、杂乱寄生，数目和虫体大小分布不均匀；猪囊虫为栗粒至米粒大小，包囊半透明，囊液较少，包囊似贴于头节，头节内陷呈淡黄色；肉孢子虫为淡黄色，长 ０． ５ ｃｍ～ １． １ｃｍ不等，均呈梭形。 显微镜观察猪囊虫可见头节浅黄色，具４个吸盘和１个顶突，顶突上有大小相间的两…     

桑尺蠖和线棉木金星尺蠖的微孢子虫对家蚕病原性和胚种传染性研究

从桑尺蠖中分离的微孢子虫，形态为长卵圆形，大小为３．５－４．１×１．６－１．９μｍ。从丝棉木金星尺蠖中分离的微孢子虫，形状为卵圆形，大小为３．２－３．７×１．６－２．１μｍ。     

桑尺蠖和丝棉木金星尺蠖的微孢子虫对家蚕病原性和胚种传染性研究

从桑尺蠖（ＨｅｍｅｒｏｐｈｉｌａａｔｒｉｌｉｎｅａｔａＢｕｔｌｅｒ）中分离的微孢子虫（简称桑尺蠖微孢子虫），形态为长卵圆形，大小为３．５～４．１×１．６～１．９μｍ。从丝棉木金星尺蠖（ＣａｌｏｓｐｉｌｏｓｓｕｓｐｅｃｔａＷａｒｒｅｎ）中分离的微孢子虫（简称丝棉木金星尺蠖微孢子虫），形状为卵圆形，大小为３．２～３．７×１．６～２．１μｍ。两种微孢子虫均能感染寄生家蚕的主要组织器官，引起蚕儿发病，但致病力要比家蚕微孢子虫（Ｎｏｓｅｍａｂｏｍｂｙｃｉｓ）弱，且能经卵传染给下一代，其胚种传染率要比家蚕微孢子虫低。     

水牛梭形住肉孢子虫包囊纯化抗原的SDS—PAGE分析

应用ＳＤＳ－ＰＡＧＥ分析了水牛梭形住肉孢子虫包囊纯化抗原的蛋白质组分。采用垂直板型电泳，连续凝胶系统法，以考马斯亮兰Ｒ－２５０染色进行ＳＤＳ－ＰＡＧＥ分析的结果表明，水牛梭形住肉孢子虫包囊纯化抗原至少由１０种蛋白质组成，分子量范围为１７．５ＫＤ～１３５ＫＤ。其中主要蛋白质组分有５种，分子量分别为１２５ＫＤ、９８ＫＤ、９０ＫＤ、６９ＫＤ及３５ＫＤ。     

驴肉孢子虫包囊的超微结构及其实验感染

对昆明地区的26头驴进行了肌肉检查，在24头驴肌肉中发现了肉孢子虫包囊，其然自感染率为92．3％，光镜下包囊呈梭形，具有锥状和棍棒状的突起，透射电镜下突起内微管在顶端松散排列，向下延伸集结成束，斜伸入基质层，有的和母细胞的膜相连，用含有包囊的驴肉实验感染犬和猫各2只，感染后在犬粪便中发现孢子囊和卵囊，潜隐期为11－13 d，剖检在2只犬的小肠固有层中查到孢子囊和卵囊，猫粪便中一直未检到孢子囊和卵囊，剖检亦未发现，表明驴肉孢了虫的终末宿主要是犬，而是猫，研究认为驴全内的肉孢子虫仅有1种，鉴定为柏氏肉孢子虫（Sarcocystis bertrami).     

几种住肉孢子虫包囊可溶性蛋白的抗原特性分析

本文对６种住肉孢子虫包裹要溶性蛋白的抗原特性进行了研究。应用ＳＤ－ＳＡＧＥ分别从包裹提取物中分离出２３～３３条蛋白区带,分子量为１４．５～１００ＫＤ。以梭形住肉孢子虫包裹抗原免疫兔血清和黄牛,水牛,绵羊,山羊和猪住肉孢子虫阳性血清对梭形柱肉孢子虫和巨型住肉孢子虫分离蛋白作免疫印迹试验（Ｗｅｓｔｅｒｎｂｌｏｔｔｉｎｇ）显示１００ＫＤ和９０ＫＤ蛋白带可被同源和异源动物血清所识别,此外,梭形住肉孢子虫包     

家蚕病原性微孢子虫SCM_7（Endoreticulatus．sp）的分离和研究

从四川省种茧育家蚕分离出的一种小型微孢子虫ＳＣＭ７，仅感染寄生蚕的中肠上皮组织；孢子卵圆形，大小２．２６±０．２１×１．１９±０．１８μｍ，孢子具单核，极丝排列７─９圈，各阶段的发育均发生在由寄主细胞内质网膜所形成的寄生囊内。其它特点也与Ｅｎｄｏｒｅｔｉｃｕｌａｔｕｓ属相符，应分类于Ｅｎｄｏｒｅｔｉｃｕｌａｔｕｓ属。该属微孢子虫在家蚕体内尚属首次发现。     

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.     

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.     

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.     

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

Tropical Animal Health and Production -     

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.     

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.     

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