Ghrelin免疫反应阳性神经元在鸡脑中的定位分布、发育性变化及禁食对其影响

本试验应用免疫组织化学方法和显微图像分析技术,研究了鸡脑Ghrelin免疫反应阳性神经元的定位分布,分析了2、16、30、44、58日龄鸡下丘脑Ghrelin免疫反应阳性神经元的发育性变化规律,并探讨了30日龄鸡分别禁食12、24、48h及重新采食4h对下丘脑Ghrelin免疫反应阳性神经元的影响。结果表明,在下丘脑弓状核、室旁核、内侧核、室周区、内侧区、外侧区,丘脑卵圆核、圆核,中脑丘中央灰质层、红核,脑桥前庭腹外侧核,小脑内侧核、小脑皮质颗粒层,大脑皮质多形细胞层等,均可观察到Ghrelin免疫反应阳性神经元;随着日龄的增长,下丘脑主要核团中的Ghrelin免疫反应阳性神经元的数量增多,免疫反应强度增强,但细胞密度下降;在禁食条件下,下丘脑Ghrelin免疫反应阳性神经元的免疫反应强度减弱,细胞密度下降。     

雏鸡脑雌激素受体的表达及分布

采用免疫组化SP法研究了雌激素受体在lO日龄雏鸡脑组织内的表达，着重观察了雌激素受体在小脑、中脑、下丘脑及端脑的分布。研究表明，雌激素受体主要存在于细胞核中，少数区域仅存于胞浆或胞膜。雌激素受体在脑内分布广泛。在小脑中部皮质的颗粒层、蒲肯野氏层，中脑的中央白质、外侧丘系腹侧核、视束、后连合等区域，雌激素受体免疫反应产物为高密度；在小脑前部皮质的颗粒层，中脑中央灰质、尾侧线形核，端脑副高纹状体等区域，雌激素受体免疫反应产物为中等密度；小脑前部皮质的蒲肯野氏细胞，下丘脑视上核，端脑原始旧纹状体等区域，雌激素受体免疫反应产物为低密度。结果揭示，在鸡脑早期发育过程中，雌激素起著广泛而重要的作用。     

强啡肽A_（1－13）免疫反应神经元在鸡脑的定位──ABC法研究

取健康成鸡（星杂２８８）１０只，经秋水仙素处理，灌流固定后取脑，作冰冻连续切片，ＡＢＣ法显示，鸡脑强啡肽Ａ１－１３（ＤｙｎＡ１－１３）免疫反应神经元分布于端脑的上纹状体、新纹状体、旧纹状体、外纹状体、海马、旁嗅区和伏隔核；间脑的下丘脑外侧核、丘脑背内侧核后部、丘脑背外侧核后部、室旁核和视前大细胞核等；中脑和延髓的视峡核、中脑外侧核背侧部、峡核、视叶脑室室周灰质、螺旋外侧核、被盖背外侧核、三叉神经中脑核、动眼神经核、中脑中央灰质、前庭核和延髓背侧网状核等。在侧脑室、第三脑室、中脑导水管和视叶脑室的室管膜上有阳性细胞和纤维分布，与脑脊液接触。结果表明，鸡脑ＤｙｎＡ１－１３阳性神经元分布十分广泛，提示ＤｙｎＡ１－１３可通过侧脑室、第三脑室、中脑导水管和视叶脑室释放入脑脊液。     

强啡肽A1—13免疫反应神经元在鸡脑的定位：ABC法研究

取健康成鸡（星杂２８８）１０只，经秋水仙素处理，灌流固定后取脑，作冰冻连续切片，ＡＢＣ法显示，鸡脑强啡肽Ａ１－１３（ＤｙｎＡ１－１３）免疫反应神经元分布于端脑的上纹状体，新纹状体、旧纹状体、外纹状体、海马、旁嗅区和伏隔核；间脑的下丘脑外侧核、丘脑背内侧核后部、丘脑背外侧核后部，室旁核和视前大细胞核等；中脑和延髓的视峡核，中脑外侧核背侧部、峡核、视叶脑室室周灰质、螺旋外侧核、被盖背外侧核、三叉神经中     

应用乙酰胆碱脂酶组织化学技术对鸡胚脑内微血管的观察

应用乙酰胆碱脂酶（ＡＣｈＥ）组织化学技术，研究了２８枚不同胚龄鸡脑内含ＡＣｈＥ阳性反应产物的微血管的分布。结果显示：在孵化第１８ｄ时，脑内已经出现了含ＡＣｈＥ阳性反应产物的微血管。ＡＣｈＥ阳性微血管主要分布在端脑的腹侧纹状体、内侧隔核、前连合核背侧区；间脑的视前区、丘脑前背外侧区、丘脑前背内侧区、丘脑背外侧区、缰核区、间脑中缝区域；中脑深核腹侧部、中脑背外侧核、中脑视叶脑室周腹内侧深层，中脑中缝区域。阳性微血管的管径均小于２０μｍ。结果提示：至少在孵化第１８ｄ时，鸡胚脑内乙酰胆碱已开始发挥其调节脑血流的作用。     

ER免疫反应产物在幼龄公山羊下丘脑-垂体-性腺轴的表达

应用免疫组化SP法时雌激素受体(ER)免疫反应产物在幼龄公山羊下丘脑、垂体、性腺中的分布特点进行了研究。结果显示，下丘脑中ER免疫反应阳性神经元主要分布在视上核、室旁核、室周核等9个核团，在视前区、下丘脑外侧区等核团也有一定数量的阳性神经元；阳性细胞呈圆形、卵圆形、三角形不等，阳性物质大多位于细胞质和胞核，阳性纤维散布于各阳性核团中；在正中隆起和第三脑室室管膜可见大量小而密集排列的深染的阳性神经元。神经垂体中可见大小不等、排列较均匀且染色较深的纤维，腺垂体中腺细胞呈强阳性着色。睾丸曲细精管中的初级精母细胞和支持细胞以及睾丸间质细胞中的ER阳性产物均为微弱表达。由此表明，幼龄公山羊雌激素除作用于性腺外，还主要作用于中枢神经系统的广泛区域，推测其参与了脑中生殖、内分泌、认知等多种功能的调控。     

Leptin长形受体mRNA与LHRH在猪前脑内共存

为了寻找Leptin在下丘脑水平调控生殖内分泌的形态学证据，用原位杂交和免疫组织化学相结合的方法，研究了5头三元杂交仔猪前脑内Leptin长形受体（OB-Rb）mRNA和黄体生成素释放激素（LHRH）免疫反应阳性物质的共存关系。结果表明，OB-Rb mRNA和LHRH免疫反应阳性神经元在下丘脑、海马结构、大脑皮层和杏仁核内共存，即上述结构内一些表达Leptin长形受体mRNA的神经元也含有LHRH免疫反应阳性物质。在下丘脑，双阳性神经元主要位于室旁核、室周核、腹内侧核、外侧区、弓状核；在大脑皮层（额叶和顶叶）内，双阳性神经元主要位于Ⅲ～Ⅴ层；在海马结构内，双阳性神经元主要位于齿状回的多形层和颗粒层以及海马的锥体细胞层。结果提示，Leptin可能通过其受体直接作用于下丘脑的促性腺激素释放激素（GnRH）神经元调节动物的生殖和内分泌活动。     

光照强度对Kisspeptin及其受体GPR54在鸡脑表达的影响

随机选用100日龄京红Ⅰ号蛋鸡,分别接受光照强度30,20,10,1 lx处理,运用免疫组化技术测定Kisspeptin和GPR54免疫反应阳性神经元在鸡中脑和间脑的分布和表达。结果显示:Kisspeptin免疫反应阳性神经元主要分布于中脑SGC、Imc、Ipc、顶盖前核(Pt)、外侧螺旋核(SPL)。在SGC、Imc、Ipc,平均灰度值和面积百分比,30,20 lx组显著高于10,1 lx组(P<0.05),在Pt和SPL,30 lx平均灰度值和面积百分比最高。GPR54免疫反应阳性神经元主要分布于中脑的lmc、Ipc、SP/IPS、nbor、SGC,平均灰度值和面积百分比,光照强度30,20 lx组显著大于l0,1 lx组(P<0.05)。Kisspeptin免疫反应阳性神经元主要分布于间脑的下丘脑后内侧核(MPH)、丘脑室旁核前部(PVa)、PHN、PVN、Rot。在Rot、PHN、PVN和PVa,Kisspeptin免疫反应阳性神经元平均灰度值和面积百分比,30,20 lx组显著大于l0,1 lx组(P>0.05);在MPH,30 lx高于20 lx,20 lx高于10 lx,10 lx高于1 lx组。GPR54免疫阳性神经元主要分布于鸡间脑PVN、GLv、Rot、PHN和CPa。平均灰度值和面积百分比在Rot,30 lx组最大,但各组间差异不显著(P>0.05),在PVN、PHN、GLv和CPa,30,20 lx组显著大于10,1 lx组(P<0.05)。Kisspeptin免疫反应阳性细胞在腺垂体的平均灰度值,光照强度20 lx组最大,面积百分比30 lx最大,但差异不显著(P>0.05)。结果表明,光照强度能促进Kisspeptin和GRP54在蛋鸡中脑和间脑表达,随光照强度增加,表达量增加。Kisspeptin接受光信息调控,通过调节GnRH分泌,参与调节鸡的生殖机能。     

催产素免疫反应神经元在鸡下丘脑的定位——PAP法研究

应用免疫组化PAP法(非标记抗体过氧化物酶-抗过氧化物酶法)研究了鸡下丘脑催产素(Oxytocin,OT)免疫反应阳性神经元的分布.结果,OT阳性神经元存在于下丘脑室旁核各亚核、视前室旁核、视上核、视前大细胞核、下丘脑外侧核、室周核、室周弓状核,在下丘脑背侧区、视前外侧区和丘脑背外侧核也有零星的OT阳性神经元,视上背侧交叉和正中隆起存在大量的OT阳性纤维和纤维末梢.此外,还观察到视前区和下丘脑前部脑基底表面以及视上核的外缘有OT阳性神经元和纤维(?)达脑的外表,在第三脑室室管膜上存在OT阳性神经元,室旁核的OT阳性细胞突起伸入到室管膜上或突出于第三脑室室腔。结果表明,OT阳性神经元在下丘脑的分布较广泛,OT向脑脊液的释放可能是多途径的.     

鸡脑催乳素免疫反应神经元的分布

运用ＡＢＣ法观察了催乳素（ＰＲＬ）免疫反应神经元在鸡脑的分布。结果,ＰＲＬ阳性胞体主要分布在视交叉上核、视前室旁核、视上核、下丘脑室旁核、弓状核和伏隔核,旧纹状体、正中隆起存在大量阳性纤维末梢,在侧脑室腹侧的室管膜和脑基底神经胶质板上也存在ＰＲＬ阳性神经元。视前室旁核、视交叉上核、下丘脑室旁核、弓状核等核团内的ＰＲＬ阳性神经元有突起向第三脑室投射,伏隔核内及侧脑室室管膜上的ＰＲＬ阳性神经元有突起伸至侧脑室,视上核的ＰＲＬ阳性神经元也有突起投射至脑基底神经胶质板,表明鸡脑内的ＰＲＬ可以释放入脑室系统,参与调节脑－脑脊液神经体液回路。     

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