nNOS阳性神经元在兔大脑皮质和小脑皮质的分布

利用SABC免疫组织化学方法,对各年龄段家兔大、小脑皮质nNOS阳性神经元的分布和形态结构进行了研究。结果显示：nNOS阳性神经元主要分布在大脑皮质的Ⅱ～Ⅳ层,小脑皮质的颗粒层;nNOS阳性神经元呈深棕色,细胞质明显,细胞核着色较淡,胞体形态多样,有三角形、圆形、椭圆形、梭形等,突起有一个或者数个;阳性神经纤维大多呈棕色串珠样,有些区域的阳性纤维交错分布,相互交织成网状;在大、小脑皮质,阳性神经元密度随年龄增长而逐渐减小,分布变得稀疏,而胞体直径却逐渐增大。由此得出：家兔大脑皮质和小脑皮质内有丰富的nNOS阳性神经元分布,神经元密度随年龄增长逐渐减小,胞体直径逐渐增大;nNOS阳性神经元及其催化产生的NO在家兔中枢神经系统发育和神经调控中起重要作用。     

nNOS阳性神经元在兔大脑皮质和小脑皮质的分布

利用SABC免疫组织化学方法,对各年龄段家兔大、小脑皮质nNOS阳性神经元的分布和形态结构进行了研究。结果显示:nNOS阳性神经元主要分布在大脑皮质的Ⅱ~Ⅳ层,小脑皮质的颗粒层;nNOS阳性神经元呈深棕色,细胞质明显,细胞核着色较淡,胞体形态多样,有三角形、圆形、椭圆形、梭形等,突起有一个或者数个;阳性神经纤维大多呈棕色串珠样,有些区域的阳性纤维交错分布,相互交织成网状;在大、小脑皮质,阳性神经元密度随年龄增长而逐渐减小,分布变得稀疏,而胞体直径却逐渐增大。由此得出:家兔大脑皮质和小脑皮质内有丰富的nNOS阳性神经元分布,神经元密度随年龄增长逐渐减小,胞体直径逐渐增大;nNOS阳性神经元及其催化产生的NO在家兔中枢神经系统发育和神经调控中起重要作用。     

去卵巢及雌激素替代治疗后家兔海马nNOS阳性神经元的形态结构及分布变化

用SABC免疫组织化学技术,观察家兔海马各区nNOS阳性神经元在去卵巢及雌激素替代治疗后的形态结构及分布变化,为雌激素类药物防治绝经后老年性痴呆症提供理论依据。结果表明,家兔海马各区都有nNOS阳性神经元分布;去卵巢后海马nNOS阳性神经元的形态结构及分布变化有区域差异性:与假手术对照组相比,在海马CA1区、CA3区、齿状回(DG)阳性神经元数量明显减少(P0.05),而在CA2区数量明显增多(P0.05)。CA1、CA3区和DG的阳性神经元胞体截面积明显变小,最长突起长度明显变短,第一级突起数变少,与假手术组有显著差异(P0.05)。CA2区阳性神经元胞体截面积明显变小(P0.05),最长突起长度、第一级突起数增多,但差异不显著(P0.05);nNOS阳性神经元的4种指标在雌激素替代治疗组与假手术组之间无显著差异(P0.05)。结果提示:雌激素可能通过影响海马nNOS的表达来影响脑的学习和记忆功能。     

兔脑一氧化氮合酶(NOS)阳性神经元的形态、结构和分布

应用MADPH—d酶组织化学技术，对兔脑一氧化氮合酶（NOS）阳性神经元的形态、结构和分布进行了研究。结果显示：①NOS阳性神经元呈蓝色，细胞核不着色，突起染色很清晰；神经元胞体大多呈多角形、梭形，还有一些呈圆形或卵圆形等。②NOS阳性神经元几乎分布于家兔的各个脑区，包括大脑皮质、小脑、丘脑下部、中脑和脑桥。小脑分布最集中，而延髓分布较少。以上结果表明，NOS阳性神经元及其催化产生的一氧化氮（NO）与中枢神经系统的诸多功能有关。     

nNOS阳性神经元在兔脑干中的分布及衰老变化

利用SABC免疫组织化学方法,研究神经型一氧化氮合酶(nNOS)阳性神经元在家兔脑干中的分布和衰老变化。结果表明,家兔脑干内分布有丰富的nNOS阳性神经元;阳性神经元主要分布于动眼神经核、红核、脑桥核、三叉神经感觉主核以及脑干的网状结构等;在中央灰质周围、上丘(前丘)浅灰质层、臂旁核、中央上核、舌下神经核、下橄榄核、楔束核等核团也发现一些阳性神经元。对动眼神经核、红核、脑桥核、三叉神经感觉主核和延髓的外侧网状核这5个核团内阳性神经元的数量、胞体平均截面积和最长突起长度在5个年龄组的变化进行了比较。与成年兔相比,仔兔、青年兔阳性神经元的数量、胞体平均截面积和最长突起长度均没有显著性变化(P0.05),但老年兔(36月龄)阳性神经元的数量和最长突起长度都显著减少(P0.05),胞体平均截面积在动眼神经核、脑桥核、三叉神经感觉主核和外侧网状核减小,而在红核则增大(P0.05)。结果提示,脑干内丰富的nNOS阳性神经元,可能通过其生成的NO参与内脏活动、感觉和运动的传导以及睡眠和觉醒等脑的高级整合功能的调节;随着年龄的增长,nNOS阳性神经元的衰老变化会影响NO的合成与释放,从而影响它们在脑干中的正常生理功能。     

鸡肠神经胆碱乙酰转换酶和多巴胺羟化酶细胞的免疫组织化学

应用SABC法免疫组织化学技术,探索鸡肠神经内胆碱乙酰转换酶（ChAc）和多巴胺羟化酶（DβH）神经元的形态及其分布。结果显示,肠神经内含有52%的ChAc神经元和36%的DβH神经元,2种神经元胞体或为多突起的多边形,或为一端有长突起的椭圆形,它们分布于神经内的神经纤维之间。DβH神经元在节间束也有个别分布。部分神经纤维呈ChAc或DβH阳性。这表明鸡肠神经系混合神经,既含副交感节后神经元,也含交感节后神经元。     

兔脑NOS阳性神经元的总体分布和形态、结构的研究

为研究一氧化氮合酶（NOS）阳性神经元在各年龄段家兔脑内的分布规律及其衰老性变化，用NADPH-d组织化学技术，观察了一氧化氮合酶阳性神经元在家兔脑内的分布和形态。结果显示：在家兔的小脑、大脑皮质、丘脑下部、中脑、脑桥等处有较多的一氧化氮合酶阳性神经元分布，延髓分布极少。NADPH—d阳性神经元呈蓝色，细胞核不着色，突起染色都很清晰。表明一氧化氮与中枢神经系统的诸多功能有关。     

兔脑nNOS阳性神经元的分布和形态结构

用SABC免疫组织化学技术,观察了神经元型一氧化氮合酶（nNOS）阳性神经元在家兔脑内的分布和形态。结果显示,在家兔的大脑皮质、小脑、中脑、脑桥等处有较多的nNOS免疫阳性神经元分布,延髓分布较为稀少。nNOS免疫阳性神经元呈棕褐色,着色主要位于胞浆内,细胞核着色较淡,nNOS阳性纤维大多呈棕色串珠样。表明一氧化氮作为神经递质,可能与脑的调控功能有关。     

山羊胚胎脊髓胶状质的形成和发育

对山羊胚胎脊髓胶状质发育的形态学变化了系统研究，结果表明：（1）山羊脊髓胶状质在胚胎第17周以后逐渐较多的神经元胞体和较大的淡染的神经元细胞核，提示胚胎第17周龄是山羊脊髓胶状质神经元发育的关键时期；（2）山羊脊髓胶状质内神经纤维在胚胎第11周时就已出现，而在髓神经纤维的髓鞘则在胚胎第15周时形成，以后逐渐发育成熟；（3）山羊脊髓胶状质的胶质细胞发育较早，在胚胎第6周末胶状质的胶质细胞发育较早，在胚胎第6周末胶状质原基刚形成时，胶质细胞核已经开始分化，到胚胎第18－19周时，胶质细胞又出现一个增殖高峰。     

不同年龄山羊小肠肌间神经丛NOS神经元形态和分布的比较

用NADPH-黄递酶组织化学方法对15日龄、4月龄和12月龄山羊小肠肌间神经丛中NOS阳性神经元形态和分布进行了比较研究。结果显示，山羊小肠肌间神经丛中NOS阳性神经元和阳性神经纤维形成清晰的三级网状结构，NOS阳性神经元形态各异，聚集在一起构成大小不等的神经节。神经丛中NOS阳性神经元的密度随年龄增长而降低，3个年龄段（从小到大）分别为27．07、20．80、16．18个／mm^2；神经元总数增加，分别为1．86×10^6、4．06×10^6、4．41×10^6个；在各个年龄小肠NOS阳性神经元密度均以空肠较低，神经元总数在各年龄均以空肠最多；山羊小肠肌间神经丛NOS阳性神经元胞体面积、胞核面积发育前期增加，后期减小；核质比随年龄下降，15日龄与4月龄和12月龄之间差异显著（P〈0．05）．小肠不同肠段的NOS神经元胞体、胞核面积分布随年龄出现一定变化，相同年龄小肠各段神经元核质比差异不显著（P〉0．05）。     

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.     

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 -