小鼠睾丸间质细胞的分离纯化与体外培养的研究

为了寻求一种快速、高效的体外分离、纯化小鼠睾丸间质细胞的方法,试验采用两种酶(胶原酶Ⅳ和0.25%胰蛋白酶)消化法和6个梯度(70%、65%、60%、55%、50%、45%)的Percoll液对小鼠睾丸间质细胞进行分离、纯化,对分离的细胞进行细胞学观察、台盼蓝染色、3β-羟基类固醇脱氢酶(3β-HSD)染色,采用物理方法、胶原酶Ⅳ+0.25%胰蛋白酶和柠檬酸钠+KCl对睾丸间质细胞进行消化传代培养。结果表明:胶原酶Ⅳ和0.25%胰蛋白酶限时消化能够获得较高活率(90%)的小鼠睾丸间质细胞;经Percoll细胞分离液分离的细胞纯度高达86%,且在34℃、5%CO2条件下培养的细胞生长良好。     

小鼠精原干细胞的分离纯化及初步鉴定

用两步酶消化法对昆明白小鼠睾丸精原细胞及精原干细胞进行了体外分离、纯化和初步鉴定。经两步酶消化所获细胞悬液内活细胞、死细胞及细胞团的百分比分别为97.03%、2.97%和2.95%;平均每个睾丸可获得4.53×105个细胞。Percoll不连续密度梯度离心初步纯化后得到4个细胞带,精原细胞主要分布在40%~50%Percoll梯度间,得到的精原细胞密度为3.20×106个/mL。因此,采用两步酶消化,结合Percoll不连续密度梯度离心法分离的昆明白小鼠精原细胞能满足体外培养的需要,还可以作为精原干细胞移植的研究材料。     

成年犬睾丸支持细胞体外分离培养的研究

为了研究犬睾丸支持细胞体外生长和生物学特征,试验采用组织培养法和酶消化法分离该细胞,并通过H.E.染色、油红O染色和AKP染色对细胞进行鉴定。结果表明:组织培养法和酶消化法均获得了成年犬睾丸支持细胞,细胞增殖活力旺盛;H.E.染色可见睾丸支持细胞呈长梭形或不规则的多边形,有3~4个突起,胞质呈浅红色;油红O染色可见支持细胞的胞质中存在脂滴,被染成桔红色,而细胞核不着色。将支持细胞与生殖细胞共培养,精原干细胞可以贴附于支持细胞表面进行体外增殖,而难以直接贴于皿底生长。AKP染色可见精原干细胞呈AKP阳性,而支持细胞呈阴性。说明成年犬支持细胞可以在体外进行培养,具有其他物种支持细胞共有的一些生物学特征。     

犊牛睾丸支持细胞的分离与冷冻保存

以新生犊牛睾丸为实验对象,应用组合酶法进行支持细胞分离培养,并研究了冷冻保存后支持细胞的生长特性。结果表明:在细胞分离时,消化睾丸组织,分离曲细精管法所获得的细胞悬液中的有效细胞数高于组织剪碎法。支持细胞体外培养,4 h后开始贴壁,3~4 d铺满培养皿底壁,传代后细胞生长较快,2 d即可增殖一代。HE染色,胞质染色较淡,而细胞核染色较深,呈圆形或椭圆形位于细胞质中央或偏位,核仁明显。采用10%FBS+10%DMSO的DMEM液做冷冻液,对细胞进行冷冻保存时,支持细胞的复苏率在65%以上。解冻后的支持细胞体外培养,4h开始有细胞贴壁,24h后大部分细胞贴壁,3~4d铺满培养皿底壁。     

牛精原干细胞的分离和纯化及体外培养的一般特性

采用两步酶消化法制备5月龄的牛生殖细胞悬液,用Percoll不连续密度梯度法分离精原细胞,接种于含10%胎牛血清的DMEM/F12培养基中,37℃,5%CO2饱和湿度培养,观察培养细胞的生长和形态变化。结果5月龄牛的曲细精管主要包含细胞为精原细胞、Sertoli细胞,每克睾丸实质收获生精上皮细胞总数平均为3.18×106个细胞,精原细胞纯化后纯度达69.27%,精原细胞主要分布于27%~35%的Percoll梯度中。牛精原干细胞体外培养6~7 d后开始分裂,20 d后精原干细胞形成小集落。结果表明用两步酶消化、Percoll不连续密度梯度法分离的精原细胞能满足体外培养的需要,可以存活并发生增殖。     

金毛犬睾丸成纤维细胞的分离、培养及鉴定

为获得金毛犬睾丸组织成纤维细胞,试验采用胰蛋白酶消化睾丸组织,对成纤维细胞进行体外分离、培养及冻存,用RT-PCR法鉴定成纤维细胞特异基因波形蛋白(vimentin),观察比较第2代(P2)及第5代(P5)细胞生长曲线、群体倍增时间、克隆形成率。结果表明:用胰蛋白酶法消化睾丸组织获得的成纤维细胞呈典型的纺锤状,其可以表达特异基因vimentin,P2及P5细胞生长曲线均呈"S"型, P2及P5成纤维细胞群体倍增时间差异不显著(P0.05);P2成纤维细胞的克隆形成率显著高于P5(P0.05)。说明通过胰蛋白酶法消化睾丸组织可高效分离和获得犬睾丸成纤维细胞。     

鸡胚睾丸支持细胞的传代培养与鉴定

以孵化18d的广西土鸡鸡胚为实验材料,采用两步酶消化法分离鸡胚睾丸支持细胞,置于37℃、5％C02的培养箱中培养,用低渗的磷酸缓冲液（PBS）处理进行纯化,并对原代和传代支持细胞进行了鉴定。结果显示,睾丸支持细胞生长良好,已传至第4代;经低渗处理,可去除绝大部分的生精细胞,获得的支持细胞纯度可达95％;鉴定结果显示,支持细胞为碱性磷酸酶（AKP）阴性;油红O染色显示,支持细胞胞质内舍有大量的脂肪滴,核内有双极小体;丫啶橙染色证明支持细胞的细胞质中富含RNA,细胞核内的DNA含量也较高;罗丹明123染色证明支持细胞含有丰富的线粒体。结论：经两步酶消化法以及低渗处理后能得到纯度较高的鸡胚睾丸支持细胞;37℃、5％CO2的培养条件适宜支持细胞的生长;AKP染色、油红O、丫啶橙和罗丹明123等方法简单易行,适用于鸡胚睾丸支持细胞的鉴定。     

睾丸支持细胞可促进鸡精原干细胞体外增殖

正扬州大学的研究人员比较了层黏连蛋白、纤维连接蛋白、胶原蛋白以及睾丸支持细胞4种不同培养系统对鸡精原干细胞(SSCs)体外增殖的作用效果。采用三酶两步消化法分离SSCs,细胞经明胶差速纯化后培养,将传至3代的SSCs重新接种于层黏连蛋白、纤维连接蛋白和胶原蛋白包被的培养皿中以及睾丸支持细胞制备的饲养层上,通过形态学、5-乙基-2′-脱氧尿嘧啶核苷(EDU)细胞增殖、qRT-PCR技术检测不同培养系统对鸡精原干细胞体外增殖的作用效果。结果表明:三组基质蛋白及睾丸支持细胞都能够促进鸡SSCs的体外     

大鼠脑皮质微血管内皮细胞的分离培养及鉴定

本研究目的在于建立一种简易可行、获得细胞纯度较高的体外分离、培养大鼠脑皮质微血管内皮细胞的方法,为进一步研究其功能打好基础。新生SD大鼠,分离大脑皮质,经匀浆、两步过滤法获得大鼠脑微血管段,用胶原酶消化后,在37℃、5%CO2培养箱中进行原代细胞培养。通过差速消化和差速贴壁方法并结合倒置显微镜下形态学的观察进行传代和纯化,利用第Ⅷ因子相关抗原免疫荧光检测法对培养的细胞进行鉴定。结果显示:成功分离培养了大鼠脑微血管内皮细胞,倒置显微镜下单个细胞呈多角形,互相融合后呈"铺路石"样,单层贴壁生长;免疫荧光检测第Ⅷ因子相关抗原呈阳性。说明本研究建立的大鼠脑微血管内皮细胞的体外培养方法,程序简单,获得的细胞纯度较高。     

水牛精原细胞的体外培养及分化

以探讨水牛精原细胞体外培养的发育潜能为目的,对3～5月龄水牛睾丸组织进行精原细胞与支持细胞的体外共培养.两步酶法消化睾丸组织来制备水牛生殖细胞悬液,接种于含10%FBS的DMEM培养液中,在37℃、5%CO2、饱和湿度下培养30 d,观察细胞的生长和形态变化,并对培养4周的细胞进行RT-PCR分析,以检测PRM-2和TP-1基因的表达情况.结果显示,水牛精原细胞体外培养24 h后,精原细胞(10.0～12.5μm)呈圆形并紧贴支持细胞上;养7～8 d后.精原细胞出现聚集状态;养10 d后,有细胞克隆形成;养30 d后,出现似长形精子细胞(8.0～10.0μm).对培养4用后的细胞进行RT-PCR分析,精子细胞特异表达基因PRM-2被检测出来.结果表明,采用本试验体外培养条件对水牛精原细胞进行培养,能够满足精原细胞体外长期培养的需要,并可以发生增殖与分化而形成似精子细胞.     

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