贝氏隐孢子虫在丝毛乌骨鸡体内发育的扫描电镜观察

使用扫描电镜观察了贝氏隐孢子虫(Cryptosporidium baileyi) 在丝毛乌骨鸡体内内生发育虫体的三维形态。大量球形虫体嵌于微绒毛丛中。滋养体呈球形,直径1.54～1.76 μm 。裂殖体呈桔瓣形或旋涡形排列,直径2.4～3.0 μm ,内含8 个香蕉形裂殖子,大小为4 μm ×0.65 μm 。成熟大配子体直径为3.5 μm 。带虫空泡内、外侧基部均可观察到梳状结构,根据带虫空泡的结构将其分为2 类,其中一类为裂殖子或小配子的带虫空泡,另一类为卵囊的带虫空泡。     

肠艾美耳球虫内生发育阶段超微结构研究——Ⅲ.小配子发育

肠艾美耳球虫(Eimeria intestinalis)小配子体及小配子的发育均在宿主细胞的带虫空泡内进行,带虫空泡内含有较多的泡内小管以及由小配子体逸出的线粒体和基质小体。多核小配子体是由最初的单核小配子体发育而成。小配子的形成首先是中心粒转变成鞭毛的基粒,此后鞭毛和顶体与小配子体成切线方式长入带虫空泡;几个小线粒体融合成一大线粒体,嵌于核前方一侧,与核一起突入带虫空泡。成熟的小配子体长约6.5μm,有两根鞭毛。鞭毛的横断面为9+2的微管结构。体部由顶体、线粒体和核组成。由顶体的腹侧向后发出4～6根微管,其中只有2～3根延伸到体后部。     

家禽隐孢子虫病的预防及控制

禽隐孢子虫病是一种原虫病。到目前为止 ,已发现和命名的隐孢子虫有 1 9种。而禽类已知的隐孢子虫主要有 3种 ;即贝氏隐孢子虫、火鸡隐孢子虫和未定名的鹌鹑隐孢子虫。近年来 ,我国不少地区相继报道了家禽的隐孢子虫病 ,对养禽业构成一定的危害。1　病原及生活史卵囊呈圆形或卵圆形 ,无色 ,表面光滑 ,无卵膜孔、孢子囊和极粒 ,卵囊内含一团颗粒状残体和 4个长形弯曲的裸露子孢子。子孢子纵向排列在残体一侧 ,无折光体 ,其核偏于后部。火鸡隐孢子虫卵囊大小为 4.5～ 6.0× 4.2～ 5 .3μm,平均 5 .2× 4.6μm;卵囊指数为 1 .0～ 1 .33,平均 1 …     

鸡卡氏住白细胞原虫各期虫体形态结构的观察研究

采取同居感染病鸡的外周血液 ,观察研究鸡卡氏住白细胞原虫 (LeucocytozoonCaulleryi)不同发育阶段的裂殖子和配子体的形态特点。光镜下 ,裂殖子呈圆点状 ,胞核圆形 ,着染紫红色 ,胞浆少量呈淡蓝色 ,位于血浆和血细胞内 ,配子体呈圆形或椭圆形 ,雌配子体 (大配子体 )虫体深蓝色 ,核较小 ,呈深粉红色 ,平均直径 16 6 5× 15 79μm ,雄配子体 (小配子体 )为淡蓝色 ,核较大 ,染色较雌配子体浅 ,平均直径为 11 2 7× 11 10 μm。电镜下 ,裂殖子呈圆形或卵圆形 ,外包有两层膜 ,外膜较薄 ,内膜较厚 ,内包一个圆形或卵圆形的核 ,位于红细胞细胞质内早期发育的配子体呈球形 ,表面隐约可见两层膜 ,细胞核大而淡染 ,位于中央 ,核膜呈双层 ,中间有明显的空隙 ,细胞质内可见数量不等的细微颗粒。     

柔嫩艾美耳球虫大配子发育和卵囊的超微结构

利用透射电镜对柔嫩艾美耳球虫大配子发育和卵囊的超微结构进行了观察。结果表明，大配子体和小配子体寄生于相邻的宿主细胞内，相伴产生。大配子体的发育、大配子的形成、受精及卵囊形成均于带虫空泡内完成。大配子体系由末代裂殖子侵入肠上皮细胞后，缩短、长大、变圆而形成，大配子体和大配子外被单位膜，细胞核位于大配子体中央，早期大配子体的细胞核有1个明显的核仁，细胞质内逐渐形成大量成囊体1、成囊体2、大量支链淀粉和脂肪体，成囊体1比成囊体2形成的早。卵囊壁有5'层，内有大量支链淀粉和指肪体。含有大配子体、大配子和合子的带虫空泡内有丰富的泡内小管，它们是大配子体、大配子和合子获得营养物质和排出代谢废物的途径。     

毁灭泰泽球虫内生发育的超微结构研究 Ⅲ.小配子生殖与小配子

毁灭泰泽球虫的小配子生殖发生在小肠上皮细胞内由单层膜围成的带虫空泡中。其细胞核的分裂过程与裂殖生殖时期的相似,但小配子体的细胞核缺少核仁,染色质在核的浅层聚集成致密的斑块。在小配子的形成过程中,核附近的中心粒转变为基粒,其中央微管消失。随后,两根鞭毛从基粒长出,突入带虫空泡。细胞核的致密部分逐渐地进入小配子体的表面突起,并最终发育为小配子的细胞核;而核的疏浅部分则留在小配子体的细胞质中,成为残体的成份。成熟的小配子拥有两根纤长的鞭毛和香蕉形的身体,体内含有长形的细胞核及在其尖端嵌入的线粒体,一组微管(4 1 1)自基粒附近向体后延伸,但仅约3根微管抵达身体的末端。     

火鸡隐孢子虫在鹌鹑体内发育史的研究

分离自鹌鹑的火鸡隐孢子虫经口感染２日龄鹌鹑，潜在期为３ｄ，开放期为４－１８ｄ。它在鹌鹑体内发育史过程为：卵巢经口接种后，于十二指肠，空肠，回肠肠腔中子孢子脱囊，至接种后６ｈ全部子孢子脱囊完毕。接种后６ｈ在小肠中出现滋养体。接种后１２ｈ在小肠中出现内含８个裂殖子的裂殖体及裂殖子，接种后４８ｈ滋养体和裂殖体开始出现于直肠。接种后５４ｈ，在小肠，直扬中出现含有１６个子弹形小配子的小配子体。小配子与大配子     

新孢子虫病（二）

《续 2 0 0 1,9(3) :46页新孢子虫病 (一 )》5　生活史　犬新孢子虫的生活史尚未完全阐明 ,据推测与龚地弓形虫的生活史类似。其全部发育过程需要两个宿主 ,在终末宿主 (目前仅发现为犬 )体内进行球虫型发育 ,在中间宿主 (牛、羊、兔、马、猪、小鼠和大鼠、犬等 )体内进行肠外期发育。经胎盘途径发生垂直传播是该虫的重要传播途径。终末宿主犬吞食了犬新孢子虫卵囊或组织包囊 ,从中释放的子孢子、缓殖子侵入宿主细胞 ,进行球虫型发育和繁殖。通过裂殖生殖产生大量裂殖子 ,经过数代裂殖生殖后 ,部分裂殖子发育成为配子体 ,大、小配子体发育成…     

草原革蜱体内驽巴贝斯虫发育形态观察

将实验室培育的“清洁”草原革蜱（Ｄｅｒｍａｃｅｎｔｏｒｎｕｔｔａｌｌｉ）饥饿成虫，饲喂在人工感染驽巴贝斯虫（Ｂａｂｅｓｉａｃａｂａｉｌｉ）的驴体上，俟雌虫饱血脱落后，置２８℃、相对湿度约９０％的培育箱中产卵孵化；再将次代幼虫和若虫饲喂在健康驴体上，待饱血脱落后仍置培育箱中蜕化。观察了各发育阶段蜱的血淋巴、肠管、唾液腺以及卵内驽巴贝斯虫的发育形态。在饱血雌虫的血淋巴中发现２种不同类型的裂殖体，即大裂殖体和小裂殖体。成熟的游离大裂殖子大小为（５．０～１６．０）μｍ×（２．０～４．５）μｍ，平均９．８５μｍ×３．Ｏμｍ；小裂殖子的大小约１．２μｍ×０．５μｍ。在肠管中见到红细胞性虫体和直径４．０～６．μｍ的球形体。在卵巢中观察到梭形、球形体及梨籽形小裂殖子。卵内发育的驽巴贝斯虫呈多形性：卵圆形、圆形、椭圆形、梭形、梨籽形、棍棒形、逗点形、半月形以及难以形容的奇形古怪的形态。次代幼虫、饥饿若虫、饱血若虫和饥饿成虫的血淋巴及肠管中所见到的都是小裂殖子（幼虫的肠管中也见到大裂殖子），唾液腺中都有子孢子存在。     

猪弓形虫病的临床症状及鉴别诊断

弓形虫又名弓形体、弓浆虫、毒浆虫,是单细胞寄生原虫,只能在活的有核细胞内生长繁殖。当有感染力的卵囊、包囊或假包囊被动物吞食后均能感染发病。本文就猪弓形虫病的临床易混淆的几种疾病的区别简单阐述。1病原猫为终末宿主,也可以为中间宿主,弓形虫发育阶段分五个期,即速殖子假包囊内外,缓殖子在组织包囊内,子孢子卵囊内,裂殖体包含裂殖子,配子体有雌（大）配子和雄（小）配子体。     

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.     

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 -