肾脏病变对隐性兔脑炎原虫病的诊断研究

为了尽快诊断隐性兔脑炎原虫病,本研究对屠宰检验发现的31只有病变的兔肾,用病理学方法进行了兔隐性脑炎原虫感染的研究。结果证明:31只兔肾均以间质性肾炎为基本病变,在3只兔肾组织的肾小管上皮中检出假囊,革兰氏染色鉴别其为兔脑炎原虫假囊。脑炎原虫性间质性肾炎的病变主要包括两种,即弥漫性间质性肾炎和增生性肉芽肿性肾炎。总之,通过对肾脏病变的检查,能及早发现隐性兔脑炎原虫病。     

兔脑炎原虫病

兔脑炎原虫病(Encephalitozoon cuniculi,别名Nosema cuniculi)通常为隐性感染,常呈致死性经过,野兔也有此病。病原是微孢子虫的脑炎原虫,主要侵袭脑和肾脏,在脑组织形成肉芽肿、非化脓性脑炎和间质性肾炎等。此病在美国许多兔群中蔓延,现已遍及世界。据报导,感染率为15～76％。一、历史:本病在1922年初,曾因青年     

脑炎原虫病

脑炎原虫病(Endephalitozoonosis)是由脑炎原虫(EncePhalitozoon)引起的一种慢性、隐性或亚临床原虫病,其病理学特征性变化主要表现为中枢神经组织的肉芽肿形成和非化脓性脑膜炎、问质性肾     

兔脑炎原虫病继发化脓性脑膜脑炎的病理形态观察

本文报道了患脑炎原虫病的病兔继发化脓性脑膜脑炎的病理变化。患脑炎原虫病的病兔由于脑组织的抵抗力低,故遭受葡萄球菌感染后,极易发生化脓性脑膜脑炎病变,此时,机体其他器官和组织的化脓性病变还不明显。临床上病兔常呈急性脓毒败血症表现,病情很快恶化。病理组织学上见脑软膜、脉络丛和脑室中均有大量嗜中性白细胞浸润,并且大部分嗜中性白细胞已发生变性和坏死,形成脓细胞。另见脑组织中有脓肿形成,在脑膜的小动脉分支发现有化脓性血栓或栓子。     

细胞培养的脑炎原虫感染家兔实验

用在体外连续培养１０代的兔脑炎原虫，接种于１２只家兔，动态地观察了脑炎原虫对家免的感染情况。实验发现，肾脏产生的病变明显早于大脑，即感染３周后，用Ｇｒａｍ＇ｓ和Ｇｏｏｄｐａｓｔｕｒｅ＇ｓ染色，即可在髓袢和远曲小管内脱落的上皮细胞中发现兔脑炎原虫。６周后即可见到间质性肾炎变化，而脑组织于感染９～１２周时才见有细胞性肉芽肿的形成；脑炎原虫具有较强的抗原性，即在感染３周后，血液中的抗体含量足以进行诊断。     

兔脑炎原虫引起脑细胞凋亡与血脑屏障破坏的关系

为了研究兔脑炎原虫如何破坏血脑屏障,侵入脑组织并引起脑肉芽肿形成,本试验采用IG染色、MGP染色,TUNEL染色和anti-GFAP染色等方法对26只有典型脑炎原虫病神经症状的病兔和10只健康兔的脑组织进行了详细研究。结果显示:病兔大脑皮质有少部分锥体细胞、血管内皮细胞及星形胶质细胞发生不同程度的凋亡。病损的血管旁有时检出兔脑炎原虫集落,附近的脑组织有巨噬细胞和小胶质细胞聚集形成的细胞性肉芽肿。用特殊染色可在血管内皮细胞、单核细胞和巨噬细胞中检出大量脑炎原虫和集虫泡。大量星形胶质细胞在病损的脑组织部位增生,包绕在聚集的巨噬细胞和小胶质细胞周围形成了肉芽肿。其粗大的足突在血管周围形成了厚层血脑屏障。总之,兔脑炎原虫通过导致血管内皮细胞和星形胶质细胞凋亡的方式而破坏了血脑屏障;通过侵入血管内皮细胞和单核细胞的方式进入脑组织,引起脑损伤。     

兔脑炎原虫性脑肉芽肿的病理学发生及形态特点

为了研究兔脑炎原虫(EC)性脑肉芽肿的病理学发生及形态特点,通过特殊染色、TUNEL染色、anti-GFAP染色和anti-NGF染色对26只病兔和10只健康对照兔的脑组织进行了详细地观察与分析。结果显示,EC能侵入血管内皮细胞引起血管损伤,可被单核细胞吞噬但不被消灭,并随之进入脑组织,导致大量星状胶质细胞增生,包围脑炎原虫集落或带虫的巨噬细胞,从而形成肉芽肿。EC性肉芽肿主要有3种形态,即细胞性肉芽肿、增生性肉芽肿和坏死性肉芽肿。构成脑肉芽肿的主要细胞为上皮样细胞、小胶质细胞、星状胶质细胞及内皮细胞,而淋巴细胞较少。结论,EC可侵入血管内皮破坏血脑屏障或随单核细胞的浸润而进入脑组织;脑肉芽肿的形成限制了EC的扩散;3种形态的脑肉芽肿实际上是一个病理过程的不同发展阶段。     

兔脑包内原虫病

家兔脑包内原虫感染多种动物,通常呈隐性感染而耐过。此次剖检3只疑为脑包内原虫病的兔,见2例脑表面及切面散在有针头大白斑,2例肾脏有多数小瘢痕,1例肾脏表面和髓质部散在有针尖大的白斑。1例整个肺叶见针尖大白色结节。组织学检查,3例脑散在有大小不等的肉芽肿,大的即为肉眼所见的白斑。还可见非化脓性髓膜炎变化,小胶质细胞弥漫性浸润及围管性细胞浸润等。肉芽肿的中心为坏死     

兔脑炎原虫病的研究进展

<正>兔脑炎原虫病又叫微孢子虫病(Microsporidiosis)或脑炎微孢子虫病,是由兔脑炎原虫引起的人畜共患寄生虫病。其病原是一些专性寄生于细胞内的真核原生动物,广泛寄生于包括人在内的大量脊椎动物和无脊椎动物体内。其中兔脑炎原虫发现于1917年,是研究最早的哺乳动物中典型的微孢子寄生虫,也是使兔自然感染的唯一微孢子虫。微孢子虫虽然发现很早,但当时未引起人们的高度重视,直到1981年艾滋病大流行后,微孢子虫才作为病     

兔脑炎原虫致脑细胞凋亡的信号转导通路的研究

为探讨兔脑炎原虫引起脑组织细胞凋亡的信号转导通路,本试验用普通染色、特殊染色、免疫组化染色和Western blot检测等方法,对40只病兔和10只对照兔的脑组织进行了研究。结果显示,病兔的脑组织中均检出了形态不一的肉芽肿和脑炎原虫。兔脑炎原虫可引起巨噬细胞和肉芽肿中的上皮样细胞表达TNF-α,anti-TNF-α抗体染色呈阳性反应。细胞凋亡信号转导通路的关键蛋白caspase-8和caspase-3在血管内皮细胞、星形胶质细胞和上皮样细胞中呈强阳性或阳性反应,被anti-caspase-8和anti-caspase-3抗体染成淡棕色或深棕色。对脑组织蛋白提取物进行Western blot检测,病兔脑组织中TNF-α,caspase-8和caspase-3的表达量明显高于对照兔,差异极显著(P0.01)。结果表明,兔脑炎原虫可刺激脑组织中的巨噬细胞和上皮样细胞产生大量TNF-α,后者与细胞膜上的TNFR结合,从而激活死亡受体通路,引起胞浆内的caspase家族发生级联反应,导致细胞凋亡。     

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