梅花鹿肾上腺组织学研究

取梅花鹿的肾上腺,做常规石蜡切片,进行H．E染色、组织学观察。结果表明,肾上腺的组织结构分为被膜、皮质和髓质。被膜由不规则致密结缔组织构成,其内分布有类似未分化的细胞,并偶见少量平滑肌纤维。皮质最厚,明显分为3个带,即球状带、束状带、网状带,其中束状带最厚,占皮质的绝大部分,髓质位于肾上腺中央部位,细胞排列成索状或团块状,髓质中央有一大的静脉,称为中央静脉。     

梅花鹿肾上腺组织学研究

取梅花鹿的肾上腺，做常规石蜡切片，进行H．E染色、组织学观察。结果表明，肾上腺的组织结构分为被膜、皮质和髓质。被膜由不规则致密结缔组织构成，其内分布有类似未分化的细胞，并偶见少量平滑肌纤维。皮质最厚，明显分为3个带，即球状带、束状带、网状带，其中束状带最厚，占皮质的绝大部分，髓质位于肾上腺中央部位，细胞排列成索状或团块状，髓质中央有一大的静脉，称为中央静脉。     

麋鹿肾上腺的组织学观察

取麋鹿肾上腺,常规石蜡切片, HE染色组织学观察。结果表明,肾上腺的组织结构分为被膜、皮质和髓质。被膜由不规则致密结缔组织构成,其内分布有类似未分化细胞。皮质最厚,明显分为3 个带,即球状带、束状带,网状带。其中,束状带最厚,占皮质的绝大部分。髓质位于肾上腺中央部位,细胞排列成索。髓质中央有一大的静脉,称中央静脉。     

麇鹿肾上腺的组织学观察

取麋鹿肾上腺，常规石蜡切片，HE染色组织学观察。结果表明，肾上腺的组织结构分为被膜、皮质和髓质。被膜由不规则致密结缔组织构成，其内分布有类似未分化细胞。皮质最厚，明显分为3个带，即球状带、束状带，网状带。其中，束状带最厚，占皮质的绝大部分。髓质位于肾上腺中央部位，细胞排列成索。髓质中央有一大的静脉，称中央静脉。     

驯鹿肾上腺组织学研究

驯鹿肾上腺的组织结构分为被膜、皮质和髓质。被膜下分布有类似未分化细胞。皮质最厚,明显分为3个带,其中,球状带占皮质厚的3．5％,束状带厚占皮质的93．4％,网状带占皮质厚的3．1％,各带均见少量体积略小、着色深的细胞。髓质分为内、外区,外区细胞呈高柱状,双行排列成索状者多见。     

恒河猴肾上腺皮质的显微与超微结构

应用光镜和透射电镜观察，恒河猴肾上腺皮质可分为球状带、束状带和网状带。其特点是：（1）被膜较发达，有时可伸入球状带将其细胞分隔为团块。（2）球状带有时呈指状指入束状带和网状带，其内可见嗜铬细胞；球状带细胞可分为明、暗2种类型，他们排列成团球状、滤泡状、索状和不规则形。（3）网状带较发达，有的可分为内、外2个区；有时网状带呈刺状伸入束状带；有时网状带细胞可见于被膜下或髓质内。（4）有时部分被膜连同皮质一起呈指状伸入髓质内。（5）皮质细胞均含丰富的溶酶体、线粒体和内质网，但不同部位的细胞所含的脂滴在数量、大小、形态和电子密度等方面存在差异。     

三苯基锡对SD大鼠肾上腺组织结构的影响

[目的]研究环境水平三苯基锡（triphenyltin,TPT）对哺乳动物肾上腺的毒性作用。[方法]将40只青春期SD大鼠随机分为3个不同剂量的试验组[0.5、5、50μg/（kg·BW）]和1个对照组[0μg/（kg·BW）]。每3 d灌胃1次,暴露54 d后,用10%水合氯醛麻醉并处死大鼠,采用石蜡切片和HE染色的方法观察SD大鼠肾上腺组织学变化特点。[结果]对照组SD大鼠肾上腺组织结构正常,皮质部球状带、束状带、网状带内细胞结构正常,胞核明显;髓质部细胞呈多边形或圆形,排列不规则,索间有血窦。与对照组相比,低剂量组肾上腺皮质和髓质内细胞的结构均无明显变化。中剂量组肾上腺球状带稍变薄,束状带和髓质细胞的胞核固缩、胞质溶解,间质组织轻微出血。高剂量组球状带细胞显著减少,与束状带界限不清,束状带细胞和髓质部细胞胞核固缩,胞质溶解现象加重,呈现细胞空泡化现象,间质组织增厚且出血现象明显。[结论]证实了一定剂量的TPT对SD大鼠肾上腺组织结构具有一定损伤作用,且呈剂量依赖性,该结果为研究TPT对哺乳动物内分泌的影响提供了形态学资料。     

双峰驼胃幽门腺区黏膜的组织学与组织化学研究

彩组织学与组织化学方法研究了双峰驼幽门腺区黏膜的微细胞结构作腺体细胞组成。双峰驼幽门腺也为高度蟠曲的分支管状腺，由柱状上皮构成，胞质中有细小的嗜伊红颗粒，主要分泌酸性糖共轭物，在腺体细胞间有分布密度大于贲门腺和胃底腺的亲银细胞（即分泌5-羟色胺的EC细胞）；黏膜肌层进入固有层，使腺体间可看到丰富的平滑肌纤维；覆盖于幽门腺区的高柱状上皮分泌中性糖共轭物和酸性糖共轭物，以前者为主。双峰驼幽门腺区在皱胃中所占面积最小，黏膜皱襞不发达，但其胃沟多而密集并且很深，可达黏膜层的1/2或2/3，常有多条深的胃小凹开口于此，从而增加了幽门腺区的表面积。研究结果显示，双峰驼幽门腺区黏膜的基本结构与其他动物及人的相似。     

双峰驼卵巢的组织结构

应用组织学方法对双峰驼卵巢的形态结构进行了显微与亚显微观察。结果显示 ,双峰驼卵巢表面被覆单层立方至单层扁平的生殖上皮 ,无排卵窝 ,上皮下为致密结缔组织白膜 ,卵巢实质由外周的皮质和中央的髓质构成。皮质中原始卵泡和初级卵胞数量稀少 ,其分布位置更靠近皮质中层 ,偶见同一卵泡内含 2个卵母细胞。体积大小和发育阶段不同的次级卵泡与三级卵泡闭锁时 ,所发生的形态变化不一致 ,可出现实心和囊状 2种闭锁卵泡。黄体中以粒性黄体细胞占优势 ,其细胞质中含大量脂质泡而呈海绵样。卵巢髓质中除含大量血管外 ,还见卵巢网分布     

双峰驼血淋巴结的形态结构研究

本研究用解剖学和组织学方法首次确定我国双峰驼具有血淋巴结这一形态结构。其外观呈卵圆形、紫红色，直径6－11mm，常见于皮下结缔组织中。在组织学上，外有一层由胶原纤维、弹性纤维和成纤维细胞构成的薄而疏松的被膜，其中有较多的血管和淋巴管；被膜伸入内部形成细小且分布散乱的小梁，但未将实质分隔成明显的小叶。实质由大量的血窦、较少的淋巴小结和淋巴窦构成，未见索状淋巴组织。血窦可分为边缘窦和中间窦，充满血液，前者位于被膜下方，较宽大，呈索状排列；后者狭窄，吻合成网；窦壁由内皮和基膜组成。淋巴窦较少，窦壁完整，明显扩张。淋巴小结多呈卵圆形，散在分布于血窦之间，由淋巴、网状组织构成，有的有明显的的生发中心。和他种动物相比，双峰驼血淋巴结在组织学上有以下特点：（1）除具有血管和血窦外，还有淋巴管和淋巴窦；（2）实质无皮质和髓质之分；（3）淋巴组织主要为淋巴小结，未见索状的淋巴组织。     

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.     

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.     

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