Evaluation of Capsule Permeability in the Equine Blastocyst

Recipient pregnancy rates following transfer of frozen-thawed blastocyst stage equine embryos remain low. To date, no protocol has been developed that would allow successful cryopreservation of this stage of embryos. These experiments characterized the amount of glycerol entering equine embryos after incubation in 1.4 M and 3.4 M glycerol solutions using tritiated glycerol and a liquid scintillation counter. Blastocyst stage equine embryos (n = 27) were collected and incubated for 15 minutes in either 1.4 M (n = 14) or 3.4 M (n = 13) tritiated glycerol solutions. Disintegrations per minute were then determined, and the percent glycerol uptake was calculated for each embryo. Percent glycerol uptake for 1.4 M or 3.4 M glycerol treatment groups was not different (P = .68). However, it was higher (P = .05) in embryos with a diameter of ≤600 μm (3.6%) compared with embryos with a diameter of >600 μm (0.4%). We concluded that glycerol more readily permeates into embryos with a diameter of ≤600 μm that do not possess a fully functional capsule compared with embryos with a diameter of >600 μm with a fully formed capsule.     

Evaluation of the Lipid Content in Bovine Oocytes and Embryos with Nile Red: a Practical Approach

In this study, the fluorescent lipid dye Nile Red, was used to demonstrate that the lipid content of immature bovine oocytes is correlated with the morphological appearance of the ooplasm. Oocytes with a uniform dark cytoplasm contained significantly more intracellular lipids in lipid droplets compared with oocytes with a granulated or pale cytoplasm (p < 0.05). Furthermore, this lipid-analysing technique was applied for the first time on single bovine in vitro embryos, showing a significant increase of the lipid content in lipid droplets after culture in the presence of serum (p < 0.05).     

Evaluation of Plasmid Delivery by Electroporation as a Means of Increasing Gonadotropin-Releasing Hormone Production in Stallions

A plasmid delivery system validated in other species was assessed for its potential for inducing long-term expression of gonadotropin-releasing hormone (GnRH) in stallions. The efficacy of this technique was demonstrated using two plasmids: pSEAP, expressing secreted embryonic alkaline phosphatase (SEAP), and pGnRH, expressing GnRH. In experiment 1, geldings were used as a model to test the effect of muscle of injection (splenius, pectoralis, and semitendinosus; n = 3 for each site) on the expression of the reporter plasmid, pSEAP. Concentrations of SEAP rose (P < .01) in jugular plasma samples, indicating uptake and expression of the pSEAP plasmid. Concentrations of SEAP were greatest (P < .05) and most consistent after pectoralis injection, and this site was chosen for injection and electroporation in the subsequent experiment. In ex-periment 2, stallions were treated with pGnRH (2 mg, n = 3; and 4 mg, n = 3) or 2 mg of pSEAP (control; n = 4) to determine the effects on the reproductive axis. Treatment with pGnRH (day 0) resulted in higher (P < .05) plasma testosterone concentrations from day 35 to 56 and increased the luteinizing hormone (LH) (P < 0.01) and testosterone (P < .1) responses to GnRH challenge on day 21. Daily semen characteristics from days 31 to 36 showed no effect (P > .1) of pGnRH treatment on seminal characteristics. It was concluded that delivery by electroporation of plasmids encoding peptide hormones may serve as a means of long-term in vivo production of peptides in the horse. Increases in LH and testosterone secretion after GnRH were observed in pGnRH-treated stallions; however, optimal conditions for expression need to be determined in future experiments.     

四种活体染色法评定家禽精子形态的研究

精子形态学检测是预测精子功能最有价值的指标之一,形态异常精子越多受精率越低。用4种伊红-苯胺黑活体染色法(Blom、Bakst、Morisson、Jaskowski)评价三黄鸡和贵妃鸡的精子形态,结果表明:染色方法显著影响精子形态,但不影响精子活率,染液对精子自然形态的保持至关重要。Blom染色法导致精子头部膨胀,畸形精子显著增多(P≤0.01),Bakst、Morisson和Jaskowski染色法均可作为评定家禽精子形态的实用方法,其中Jaskowski染色方法最简便经济,值得在家禽生产中推广应用。     

银染mRNA差异显示方法在致突变实验中的初步应用

为建立在药物致突变研究中应用银染 m RNA差异显示的方法 ,试验提取未经过 /经过环磷酰胺处理的 Balb/c小鼠肝组织的总 RNA ,并以此为模板 ,采用 d T1 2 CG、d T1 2 AG、d T1 2 GG为锚定引物 ,通过反转录、差异显示 PCR反应 ,以 6 %变性聚丙烯酰胺凝胶电泳分离差异条带 ,回收后将其再扩增。结果表明 ,RNA投入量为 3μg、镁离子浓度为 1.5～ 2 .0 mm ol/L、退火温度为 4 0℃时 ,扩增的片段条带清晰、背景低 ,差异条带明显 ,再扩增条带单一。银染 m RNA差异显示技术可成功应用于药物致突变的研究。     

Effect of Growth Factors on Bovine Blastocyst Development in a Serum-Free Medium

Shamsuddin, M.: Effect of growth factors on bovine blastocyst development in a serum-free medium. Acta vet. scand. 1994, 35, 141-147. - To investigate the effect of growth factors on pre-implantation development, bovine zygotes, produced by in vitro fertilization (IVF) of in vitro-matured (IVM) oocytes, were cultured in a serum-free medium to which the following growth factors were added one at a time: epidermal growth factor (EGF), acidic fibroblast growth factor (a-FGF), insulin-like growth factor-II (IGF-II), platelet-derived growth factor from human platelets (PDGF), and platelet-derived growth factor-AB, human, recombinant (PDGF-AB). All growth factors were added at a dose of either 10 or 50 ng/ml, except PDGF which was added at a dose of either 5 or 15 ng/ml. The control medium was TCM 199 supplemented with sodium pyruvate (0.25 mmol/1), BSA (10 mg/ml), insulin (5 μg/ml), transferrin (5 μg/ml), and sodium selenite (5 ng/ml). Embryos were cultured for 8 days (day of insemination = Day 0). The mean percentages of first cleavage on Day 2 varied from 67% to 86% and the differences between the 2 doses, or between the control and growth factor- treated groups were not significant (p≥0.13). The effects of the two doses on subsequent development up to the blastocyst stage did not differ either (p≥0.12). There was no stimulatory effect of any of the used exogenous growth factors on embryo development up to the morula or blastocyst stage on Day 7, or blastocyst stage on Day 8. Moreover, medium supplemented with PDGF had fewer blastocysts than the control (p≤0.03). The results indicate that growth factor supplementation may not necessarily increase the yield of blastocysts from bovine IVM-IVF oocytes in a serum-free medium.     

Enzootic Pneumonia of Pigs: Identification of a Causative Mycoplasma in Infected Pigs and in Cultures by Immunofluorescent Staining

Immunofluorescent staining has been used to identify Mycoplasma hyopneumoniae in smears of broth cultures, in infected pig testicle cell cultures, and in frozen cut sections of pneumonic lungs from field and experimentally produced cases of enzootic pneumonia. In the pneumonic pig lung, fluorescent staining was limited to the surface of the bronchial and bronchiolar epithelium and to the contained exudate. In a series of trials using experimentally infected pigs fluorescence was not detected until 25 days post-infection and was regularly seen in pigs killed thereafter. Porcine immune globulin precipitated from the serum of experimentally infected pigs and conjugated with fluorescein isothiocyanate was reactive and specific for the detection of M. hyopneumoniae. Immune globulin conjugates prepared from the serum of hyperimmunized rabbits were reactive but in some cases produced a faint non-specific staining of frozen tissue sections. No such non-specific reactions were noted on stained culture smears or cell cultures.

Fluorescence was not seen in known positive preparations stained with non-immune pig globulin conjugates or in preparations from uninoculated cell cultures or pigs, stained with non-immune or immune globulin conjugates.

Mycoplasma hyorhinis was detected by immunofluorescent staining with homologous conjugates, in smears of broth cultures and in tissue sections from pigs with polyserositis.

Immunofluorescent staining was found to be species specific and useful for the early species identification of mycoplasma isolated from pigs.

     

夯实基础科学监管形成合力切实提高我国动物源性产品安全水平

在全球经济一体化的背景下,动物源性食品安全已成为世界公共卫生的主要关注点,动物源性食品安全问题影响着世界市场经济竞争秩序、经济发展及进出口贸易,从而成为全球共同面临的威胁和国家社会必须承担的共同责任。本文深入分析研究了我国动物源性产品安全工作面临新的挑战,创新的提出了"动物源性产品安全监管科学化"的理念,全面梳理并提出了提高我国动物源性产品安全水平的政策建议,为促进养殖业健康发展,维护公共卫生安全及提高动物源性产品国际竞争力,提供了有力支撑。     

犬肿瘤脾脏摘除治愈血小板减少性紫癜病例

10岁杂交老犬,周身出现紫癜,脾脏检查有肿瘤生成,经2次保守治疗紫癜褪去,都是间隔不到1周又复发,后通过摘除犬脾而得到治愈.     

犬多发性混合性乳腺瘤的特殊染色鉴别

为了鉴别犬多发性混合性乳腺瘤的形态结构及其发生的关系,用特殊染色法对两例肿瘤进行了详细的病理学观察及分析。结果表明,多发性混合性乳腺瘤组织中除了有单纯性乳腺瘤结构外,还包括乳头状瘤和囊腺瘤的结构,间质中有大量的结缔组织增生,形成条索状的胶原纤维束,增生的结缔化生形成了软骨组织。当乳腺瘤上皮增生过快时,可形成乳腺癌样的组织团块。研究表明,多发性混合性乳腺瘤可继发于单纯性乳腺瘤,是乳腺瘤加重的形态表现;混合性乳腺瘤组织的软骨组织是由结缔组织化生而来。由于多发性混合性乳腺瘤中有多种组织成分不断增生,并可出现乳腺癌样的组织团块,所以该瘤易于发生恶变。     

Prevention of Milk Fever by Dietary Means: The Effect of a Concentrate Fortified with Mineral Salts

A concentrate was fortified with mineral salts by adding CaCl₂, Al₂(SO₄)₃ and MgSO₄ to standard concentrate A and pelleting the product When used as feed supplement from 3 weeks pre partum to 1 week post partum this concentrate mixture produced the intended negative alkali alkalinity in the total feed ration in 20 out of 25 cows. Of these 17 remained healthy in spite of a history of milk fever for the majority of them. Two cows got milk fever and 1 showed weak symptoms.     

Osmoregulation by Means of a Hitherto Unsuspected Osmoregulatory Organ in Two Grapsid Crabs

Cape sugarbirds, Promerops cafer, preferred certain pro tea bushes as nest-sites. These bushes were characterized by relatively large leaves and dense foliage. Nests were usually placed in the central parts of bushes Nest-sites were shielded from the cold night sky, and were associated with relatively favourable air temperatures and protection from wind in a season of unfavourable weather. Data on microclimate of nest-sites, together with those on heat loss from an incubating sugarbird, were interpreted in relation to nest-site selection as adaptive behaviour promoting breeding success through conservation of energy. Sugarbirds nesting relatively high off the ground and in dense vegetation were considered to be decreasing die risk of exposure to predators.     

封片时间对脂质染色的细胞爬片保存的影响

为研究封片时间对经过脂质染色的细胞爬片保存效果的影响，采用原代肝细胞体外培养的方法培养大鼠肝细胞并制作细胞爬片，油红。染色，光学显微镜成像系统观察不同时间段细胞爬片的封片。结果表明，染色后立即封湿片的细胞爬片结构显示细腻；而染色后充分干燥后再封片的细胞爬片细胞表面出现皱缩皲裂，与前者比较有极显著差异。从而说明不同的封片时间对脂质染色的细胞爬片保存效果的影响。     

利用CTC染色进行猪精子不同体外获能方法的比较

为了探讨不同方法对猪精子体外获能的影响,本试验以猪的新鲜精液为研究对象,分别经肝素上游法、钙离子载体诱导法和咖啡因诱导法进行精子不同获能时间的处理,并利用金霉素荧光染色法（chlortetracycline,CTC）对其获能效果进行检验。结果表明,采用肝素上游法孵育40 min处理后,精子的获能比例显著高于其他各处理组（P<0.05）,说明肝素上游法可以较好地诱发猪精子在体外获能。     

Identification of Aerococcus Viridans by Means of Co-Agglutination

Gaffkemia, which has recently been reviewed by Stewart & Rabin (1970) and by Stewart (1975), is a fatal bacterial disease of the American and European lobster (Homarus americanus and Homarus vulgaris) (Snieszko & Taylor 1947). The causal agent, first classified as Gaffkya homari (Hitchner & Snieszko 1947), is now classified as Aerococcus viridans (Williams et aL 1953, Buchanan & Gibbons 1974).     

黄石市采用抗体检测考评畜禽防疫质量

2002年以来,我市采取以抗体检测为主的方法考评畜禽防疫质量的新机制,对全市畜禽防疫工作质量进行考评,取得令人满意的效果,全市畜禽防疫工作质量逐年提高,发病率逐年下降,真正让畜禽防疫免疫工作落到实处,取得实效。1基本情况黄石市位于鄂东南,现辖大冶市、阳新县及四个城区和一个开发区,总人口258万,其中城镇人口120万,农业人口138万。2004年农业总产值20亿元,其中牧业产值4.8亿元,占农业总产值的24%。常年牲猪存栏65万头,出栏90万头;牛存栏8.2万头;羊存栏6.2万只;家禽存笼360万只。其中万头以上规模猪场17个,是湖北省规模化猪场较为集中…