柔嫩艾美耳球与鸡体的相互作用

鸡吞食柔嫩艾美耳球虫卵囊后感染，子孢子穿过绒毛上皮和固有层，进入隐窝上皮细胞，经数次无性生殖和有性生殖，形成裂殖子和配子体。大配子被小配子受精后发育成卵囊并脱落到粪便中，鸡感染球虫后，鸡体免疫系统抑制球虫的发育有三个时期：子孢子寻找穿透位点时；子孢在子绒毛上皮时；子孢子穿过固有层时。     

斯氏艾美耳球虫细胞化学的研究

本文用组织化学技术对斯氏艾美耳球虫内生阶段和子孢子的细胞化学进行了研究。结果发现,多糖存在于第二代裂殖体、大配子体、大配子、合子、未孢子化卵囊和子孢子内。脂肪存在于第二代A型裂殖体、大配子、合子、未孢子化卵囊及子孢子内。整个内生发育阶段的虫体和子孢子均含有蛋白质。两型裂殖体、大、小配子体、合子和子孢子内均有Feugan反应阳性的DNA存在,而RNA存在于整个内生阶段和子孢子中。内生阶段虫体和子孢子均有ACP和SDH,然而ALP只存在于内生阶段,子孢子缺乏。     

柔嫩艾美耳球虫与鸡体的相互作用

鸡吞食柔嫩艾美耳球虫卵囊后感染，子孢子穿过绒毛上皮和固有层，进入隐窝上皮细胞，经数次无性生殖和有性生殖，形成裂殖子和配子体。大配子被小配子受精后发育成卵囊，并脱落到粪便中，鸡感染球虫后，鸡体免疫系统抑制球虫的发育有三个时期：子孢子寻找穿透位点时；子孢子在绒毛上皮时；子孢子穿过固有层时。据此，我们研究了抗球虫免疫中诱导和效应阶段的决定因素。结果表明，子孢子在固有层中的穿透诱导了免疫；子孢子是免疫有关的最重要的发育阶段；细胞毒性Ｔ细胞对抑制球虫发育是必需的。     

鸡球虫体外HCT-8细胞培养模型的建立

由柔嫩艾美耳球虫(Eimeria tenella)引起的球虫病严重损害鸡的肠道健康,给养鸡业造成巨大的经济损失。E.tenella寄生在鸡盲肠上皮细胞,体外培养可在鸡原代肾细胞内发育成卵囊完成内生发育过程,而在其他传代细胞系内只能完成部分生殖阶段,为了延长其在细胞内的发育进程,建立了鸡球虫HCT-8细胞培养模型。将新鲜制备的E.tenella子孢子接种HCT-8细胞,制备细胞爬片,分别进行HE染色和DAPI染色,观察子孢子在细胞内的发育状况。结果表明,子孢子在接种后6 h即可入侵HCT-8细胞,随后子孢子发育为滋养体至48 h形成第一代裂殖体,至54h第一代裂殖子释放,于72 h形成第二代裂殖体,在144 h第二代裂殖子释放出来,继续培养至168h未见到卵囊形成,而试验虫株接种鸡体后在144～168 h即可观察到大量未孢子化卵囊排出体外,据此确定子孢子在该细胞内的发育过程结束。本研究所建立的鸡球虫细胞培养模型将子孢子发育至第二代裂殖生殖阶段,将发育阶段向前推进了一个进程,为鸡球虫相关研究工作的开展提供技术平台。     

鸡球虫病防制经验谈

鸡球虫病是由９种鸡艾美尔球虫引起疫病的总称。虽然各种球虫在无性繁殖的代数和每一发育阶段所需的时间不同，但其生活史大同小异，所以仍可以柔嫩艾美尔球虫的生活史作为所有艾美尔属虫种的代表（图１）。鸡食入球虫卵囊后，卵囊壁在肌胃中被碾碎，释放出子孢子，进入小肠粘膜，并开始繁殖。至少需经两代无性繁殖（称之为裂殖生殖），随后进行有性繁殖。在此过程中，小的能运动的小配子寻找大配子，并与之结合，形成合子，合子发育成熟为卵囊，卵囊从肠粘膜上释放，随粪便排出。整个过程约为４－６天，具体时间依虫种而定。一．流行病学球…     

脆弱艾美尔球虫在鸡胚培养中内生性发育史的研究

脆弱艾美尔球虫在鸡胚培养中,可以像在鸡的肠道内一样地完成全部内生性发育史。用体外脱囊的球虫子孢子接种于9～11仅龄鸡胚的尿囊胜中。在40℃～41℃下培养,可在绒毛尿囊膜细胞内观察到无性世代和有性世代两个发育阶段。出现第一、二、三代裂殖体,以及大配子体、小配子体和卵囊。成熟的第一代裂殖体在绒毛尿囊膜细胞内最早出现于感染后48小时,第二代为94小时,第三代为132小时。大配子体和小配子体、卵囊分别于感染后132和144小时形成,均寄生在绒毛尿囊膜表层。各期虫体的发生时间与鸡体内基本相似,从子孢子开始到产生次代卵囊,完成全部内生性发育需要144小时。     

药物对柔嫩艾美尔球虫内生阶段超微结构影响的研究

本文对柔嫩艾美尔球虫(Eimeria tenella)在鸡体内正常发育的超微结构和分别用三种抗球虫药物处理情况下超微结构的变化进行了观察和比较研究,注意到125ppm尼卡巴嗪(Nicarbazin)能引起裂殖生殖阶段的滋养体或初生裂殖体及裂殖子的线粒体、内质网等膜结构系统和核的异常变化;168ppm磺胺喹恶啉(SQ)对滋养体、初生裂殖体及裂殖子、大配子和卵囊壁的形成均有影响,对裂殖生殖阶段的影响主要表现为核膜的增生复制等一系列核的异常变化;对配子生殖阶段的影响表现为Ⅰ型和Ⅱ型卵囊壁形成颗粒(WFB_1和WFB_2)的异常变化;80ppm盐霉素(Salinomycin)对上皮内淋巴细胞(IEL)中的子孢子及粘膜中成熟裂殖子的影响表现为表皮的分离或破裂及胞浆内微线粒(MN)和多糖颗粒(PG)等的轮廓模糊。由药物引起的其他一些超微结构的异常变化也作了观察和描述。     

家蚕微孢子原虫在Antheraea eucalypti细胞中的增殖

家蚕微孢子原虫经ＫＯＨ处理后,接种于Ａｎｔｈｅｒａｅａ ｅｕｃａｌｙｐｔｉ细胞系,调查其生活史,ＫＯＨ处理的孢子发芽率约为４４．３％,Ａｎｔｈｅｒａｅａ ｅｕｃａｌｙｐｔｉ细胞的初期感染率约为３０％,接种３６ｈ后,裂殖子数量急速增加,７２ｈ达到最高峰。接种４８ｈ后可观察到短极丝孢子发芽后形成的空孢壳和二次感染体。感染Ｎｏｓｅｍａ ｂｏｍｂｙｃｉｓ ４８ｈ前的家蚕血淋巴对ＢｍＮ细胞无感染性,而感染２     

禽弓形体病的调查与诊断

弓形体是世界性分布的人畜共患寄生虫病,弓形体的终末宿主是猫科动物,禽类为中间宿主。弓形体根据发育阶段分五个型,滋养体、包囊、裂殖体、配子体和卵囊。在禽类中间宿体主体内只能发育成滋养体和包囊。滋养体在禽类体内常以单个游离于组织中,多呈垂形、橄榄形,一端稍尖,另一端钝圆,核偏于钝端。也有多个滋养体聚集在一个细胞内。正在繁殖的虫体形状多样,呈球形、卵园形、月牙形和弓形等。弓形体在中间宿主体内细胞中繁殖阶段,正是临床有急性症状时期。滋养体在宿主的脑、眼、心、肺、肝、肾和骨胳肌中发育在包囊。当猫科动物摄入滋养体、包囊后,弓形体即在其肠壁细胞中完成裂殖生殖和配子生殖阶段,最后形成卵囊。卵囊内的子孢子是通过粪便污染而传播。     

鹅球虫Eimeria fulva的生活史及其感染引起的组织病理变化观察

12只10日龄雏鹅分别接种7.0×105~1.5×106个孢子化E im eria fu lva卵囊,在接种后24~264 h分期扑杀,对E.fu lva的生活史及其感染引起的组织病理变化进行了动态性观察。在内生性发育过程中,E.fu lva至少有2个世代的裂殖生殖阶段,每个成熟的裂殖体含15个左右的裂殖子。接种后168 h左右,虫体进入配子生殖阶段。感染后7.5 d始有卵囊排出,显露期为2.5 d。25℃下卵囊孢子化时间为60~84 h。E.fu lva可寄生于整个肠道和泄殖腔的绒毛上皮、肠腺和固有膜中,引起上皮坏死、脱落以及肠壁水肿、出血和炎性细胞浸润等。病变以空肠和回肠较为严重。感染鹅严重腹泻,但不会发生死亡。研究结果表明,E.fu lva对雏鹅具有中等程度的致病性。     

白术、微米白术和白术多糖对断奶仔猪生长性能和肠道形态及微生态区系的影响

试验选用96头平均体重14.82 kg左右的杜×长×大断奶仔猪,随机分成4组,每组3栏,每栏8头(公母各半)。对照组饲喂基础日粮,试验1、2、3组分别添加1%80目白术、0.2%白术多糖和1%微米白术。试验期30 d。结果表明:在生长性能方面,与对照组相比,1%微米白术添加组可显著提高日增重(P0.05)、降低饲料增重比和腹泻率,而且效果优于1%80目白术组和0.2%白术多糖组,在肠道形态和肠道微生态区系方面,与对照组相比,日粮添加1%80目白术、0.2%白术多糖、1%微米白术均可不同程度的提高十二指肠和空肠的绒毛高度,加深十二指肠和空肠的隐窝深度,并且增加肠道微生态区系的多样性,其中以1%微米白术添加组的效果最佳。     

Prevalence and seasonal incidence of nematode parasites and fluke infections of sheep and goats in eastern Ethiopia

Sissay, M.M., Uggla, A. and Waller, P.J., XXXX. Prevalence and seasonal incidence of nematode parasites and fluke infections of sheep and goats in eastern Ethiopia. Tropical Animal Health and Production, XXXX. A 2-year abattoir survey was carried out to determine the prevalence, abundance and seasonal incidence of gastro-intestinal (GI) nematodes and trematodes (flukes) of sheep and goats in the semi-arid zone of eastern Ethiopia. During May 2003 to April 2005, viscera including liver, lungs and GI tracts were collected from 655 sheep and 632 goats slaughtered at 4 abattoirs located in the towns of Haramaya, Harar, Dire Dawa and Jijiga in eastern Ethiopia. All animals were raised in the farming areas located within the community boundaries for each town. Collected materials were transported within 24 h to the parasitology laboratory of Haramaya University for immediate processing. Thirteen species belonging to 9 genera of GI nematodes (Haemonchus contortus, Trichostrongylus axei, T. colubriformis, T. vitrinus, Nematodirus filicollis, N. spathiger, Oesophagostomum columbianum, O. venulosum, Strongyloides papillosus, Bunostomum trigonocephalum, Trichuris ovis, Cooperia curticei and Chabertia ovina), and 4 species belonging to 3 genera of trematodes (Fasciola hepatica, F. gigantica, Paramphistomum {Calicohoron} microbothrium and Dicrocoelium dendriticum) were recorded in both sheep and goats. All animals in this investigation were infected with multiple species to varying degrees. The mean burdens of adult nematodes were generally moderate in both sheep and goats and showed patterns of seasonal abundance that corresponded with the bi-modal annual rainfall pattern, with highest burdens around the middle of the rainy season. In both sheep and goats there were significant differences in the mean worm burdens and abundance of the different nematode species between the four geographic locations, with worm burdens in the Haramaya and Harar areas greater than those observed in the Dire Dawa and Jijiga locations. Similar seasonal variations were also observed in the prevalence of flukes. But there were no significant differences in the prevalence of each fluke species between the four locations. Overall, the results showed that Haemonchus, Trichostrongylus, Nematodirus, Oesophagostomum, Fasciola and Paramphistomum species were the most abundant helminth parasites of sheep and goats in eastern Ethiopia.     

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.     

Y‐chromosomal variation of local goat breeds of Turkey close to the domestication centre

Genetic variations in chromosome Y are enabling researchers to identify paternal lineages, which are informative for introgressions and migrations. In this study, the male‐specific region markers, sex‐determining region‐Y (SRY), amelogenin (AMELY) and zinc finger (ZFY) were analysed in seven Turkish native goat breeds, Angora, Kilis, Hair, Honaml?, Norduz, Gürcü and Abaza. A SNP in the ZFY gene defined a new haplotype Y2C. All domestic haplogroups originate from Capra aegagrus, while the finding of Y1A, Y1B, Y2A and Y2C in 32, 4, 126 and 2 Turkish domestic goats, respectively, appears to indicate a predomestic origin of the major haplotypes. The occurrence of four haplotypes in the Hair goat and, in contrast, a frequency of 96% of Y1A in the Kilis breed illustrate that Y‐chromosomal variants have a more breed‐dependent distribution than mitochondrial or autosomal DNA. This probably reflects male founder effects, but a role in adaptation cannot be excluded.     

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.     

Feline intracranial neoplasia: retrospective review of 160 cases (1985-2001)

The purpose of this study was to determine the frequency of different tumor types within a large cohort of cats with intracranial neoplasia and to attempt to correlate signalment, tumor size and location, and survival time for each tumor. Medical records of 160 cats with confirmed intracranial neoplasia evaluated between 1985 and 2001 were reviewed. Parameters evaluated included age, sex, breed, FeLV/FIV status, clinical signs, duration of signs, number of tumors, tumor location(s), imaging results, treatment, survival times, and histopathologic diagnosis. Most of the cats were older (11.3 +/- 3.8 years). Primary tumors accounted for 70.6% of cases. Metastasis and direct extension of secondary tumors accounted for only 5.6 and 3.8% of cases, respectively. Twelve cats (7.5%) had 2 or more discrete tumors of the same type, whereas 16 cats (10.0%) had 2 different types of intracranial tumors. The most common tumor types were meningioma (n = 93, 58.1%), lymphoma (n = 23, 14.4%), pituitary tumors (n = 14, 8.8%), and gliomas (n = 12, 7.5%). The most common neurological signs were altered consciousness (n = 42, 26.2%), circling (n = 36, 22.5%), and seizures (n = 36, 22.5%). Cats without specific neurological signs were common (n = 34, 21.2%). The tumor was considered an incidental finding in 30 (18.8%) cats. In addition to expected relationships (eg, meninges and meningioma, pituitary and pituitary tumors), we found that lesion location was predictive of tumor type with diffuse cerebral or brainstem involvement predictive of lymphoma and third ventricle involvement predictive of meningioma.