鸡胚模型在生物研究中的应用进展

实验动物模型在预防、诊断、治疗疾病和探讨疾病的发生机制等方面起到了至关重要的作用。鸡胚发育过程清楚,利用鸡胚本身的结构特点,可作为研究与胚胎发育相关的生物学实验模型。另外,鸡胚绒毛尿囊膜（CAM）血管丰富,是天然免疫缺陷宿主,可作为血管药理学、肿瘤学等方面研究的一个较为理想的实验模型。本文综述了鸡胚模型在生物实验研究中的应用进展。     

鸡胚宫颈癌模型的建立及其生物学特性

目的建立人宫颈癌鸡胚模型,探讨其形态学及生物学特性。方法将Hela细胞接种于鸡胚绒毛尿囊膜,观察影响宫颈癌鸡胚移植瘤成活可能的因素、移植瘤生长特性、形态、生物学特性。结果成功建立了人宫颈癌鸡胚移植瘤模型。移植后瘤易于生长,具有较强的血管诱导作用。光镜下显示移植后瘤具有与人宫颈癌相似的组织结构。结论该模型容易建立,能动态观察宫颈癌诱导血管生成的全过程,可用于宫颈癌的实验研究。     

随机引物PCR扩增鸡胚致死孤儿病毒DNA的研究

在电镜下观察鸭病毒性肝炎病毒鸡胚尿囊液种毒时,另看到一大小为70—80nm,无囊膜,20面体对称的病毒颗粒。为了解该污染病毒,作者挑选了4条随机引物对此未知病毒分别进行反转录PCR和直接PCR扩增,结果共扩增出3条基因片段,经测序(一个反应)后分析与禽腺病毒1型——鸡胚致死孤儿病毒基因组部分序列同源性分别高达99．5％、99．6％和99．5％。从而得知鸭病毒性肝炎病毒鸡胚尿囊液种毒受到了鸡胚致死孤儿病毒的严重污染。     

应用ELISA法检测SARS-Ab

探讨对SAPS病毒进行临床诊断,分析ELISA法检测SARS-Ab的情况。结果显示对照组检测均为阴性,测试组发病12d前、后阳性检出率分别为2．7％、92％,总检出率为94．7％。29例疑似病人阳性检出率为31％。提示该方法敏感性、特异性强,但12d以前检出率低,而13-16d以后阳性率明显提高。     

ELISA法检测疫苗中牛血清残留量的适用性研究

为了验证ELISA法对病毒性疫苗中残余牛血清蛋白检测的适用性,用牛血清蛋白ELISA测定法与牛血清白蛋白ELISA测定法、牛血清IgG-ELISA测定法对麻疹疫苗、风疹疫苗、腮腺炎疫苗洗涤前病毒培养液、洗涤后病毒收获液以及多种成品疫苗中的残余牛血清蛋白含量进行了测定。结果显示,麻疹疫苗、风疹疫苗、腮腺炎疫苗洗涤前病毒培养液中牛血清白蛋白含量依次为IgG含量的70.5倍、65倍、84.3倍,洗涤后病毒收获液中两者比值分别为4.2、1.8和8.1;牛血清白蛋白ELISA法和牛血清蛋白ELISA法均能检测出疫苗中牛血清白蛋白,但前者测不出牛血清IgG,而后者可准确检测牛血清IgG。牛血清蛋白ELISA测定法可同时检测牛血清白蛋白和牛血清IgG,更适用于疫苗残余牛血清蛋白含量的测定。     

在鸡胚绒毛尿囊膜上评价血管生成技术的应用与优化

目的：用鸡胚绒毛尿囊膜（CAM）评价血管生成并进行优化,为抗血管生成药物筛选提供良好的体内实验模型。方法：对CAM技术的各个环节,包括合适日龄胚蛋选择、蛋壳开窗及暴露CAM的方法、载体选择、结果分析等进行了实验对比。结果：采取气室开窗,以甲基纤维素为药物载体,促进血管生成的药物在孵化11d以后、抑制血管生成的药物在孵化7～9d给药,鸡胚存活率为85.8%,生长状况良好,被检测药物有明显的抑制或促进血管生成的效应。结论：通过优化建立了操作简便、鸡胚存活率高的在CAM上评价血管生成的技术;应用CAM技术评价了若干影响血管生成的因子。     

平阳霉素对鸡胚绒毛尿囊膜血管内皮细胞生长的影响

利用鸡胚绒毛尿囊膜研究平阳霉素对血管内皮细胞移动和增殖的影响.(1)内皮细胞移动采用组织学切片、常规H-E染色,通过观察不同胚龄鸡胚CAM的组织学结构即可判定毛细血管EC移动.发现鸡胚在第8、10、12天胚龄时CAM EC都位于外胚层绒毛膜上皮之下,随胚龄增大,EC逐渐由中胚层移向外胚层.而孵育至第14天后(16、18天)CAM毛细血管EC大都移至外胚层上皮之上,紧贴壳膜.PY可明显抑制EC移动,使第18天胚龄时早已该移至外胚层之上的毛细血管EC仍停留在外胚层上皮之下.(2)内皮细胞增殖用放射自显影技术对第10天胚龄的鸡胚CAM EC进行3H-TdR标记,标记率即反映EC增殖的程度.同时用血管生长抑制剂PY对比研究对EC增殖的影响.对照组和实验组EC 3H-TdR标记率分别为41.5±3.4%和20.3±1.5%,PY可使CAM EC的DNA合成减少,即抑制EC增殖.鸡胚CAM可作为研究EC移动和增殖的体内模型,用于血管生成刺激因子和抑制因子的筛选和研究.     

流感疫苗中间品-鸡胚尿囊病毒液质量控制的研究

为建立流感疫苗中间品-鸡胚尿囊病毒液质量控制点提供依据。用鲎试剂法、微生物限度检查法、沙门菌检查法检测流感疫苗中间品一鸡胚尿囊病毒液的细菌内毒素含量、微生物限度及沙门菌。在300份鸡胚尿囊病毒液中,细菌内毒素含量大于5EU／mL的阳检率为5％;微生物限度检查中小于lO个／mL细菌菌落数的占78．67％,小于10个／mL霉菌菌落数的占80．67％,小于10个／mL酵母菌菌落数的占88．67％。沙门菌属的阳检率为4％,其中未检出A～F群的沙门菌。对流感疫苗中间品-鸡胚尿囊病毒液进行细菌内毒素,微生物限度及沙门菌检测可避免不合格尿囊病毒液进入后续生产,污染后续中间品。     

人大肠癌鸡胚尿囊膜移植模型的建立及血管生成特征的观察

目的研究人大肠癌腺癌细胞株HT-29鸡胚尿囊膜移植模型建立的方法,观察和分析其血管生成的特征。方法将不同浓度的人大肠癌腺癌细胞株HT-29接种于鸡胚尿囊膜（chick embryo chorioallantoic membrane,CAM）,观察影响大肠癌鸡胚移植模型瘤体成活的因素、瘤体生长特征和血管生成情况。结果建立了人大肠癌CAM移植模型。移植模型瘤体易于生长,具有较强的血管生成作用。结论该模型易于复制,能动态观察大肠癌的血管生成过程,可用于大肠癌的生物学行为、药物筛选等领域的研究。     

鸡胚内抗氧化物质的分布与变化

生物体内存在多种内源性抗氧化物质,在生命过程中发挥着基本的防御功能,是人们十分关注的研究领域。本文综述了近年来鸡胚内抗氧化物质的形成与来源等研究成果,分析了鸡胚孵育过程中维生素(A、C、E)、类胡萝卜素、硒、过氧化氢酶和超氧化物歧化酶等主要抗氧化物质的分布与变化,及内源性抗氧化系统的形成,旨在为今后的研究提供有益的科学依据。     

ELISA检测抗-HIV室内质控血清的制备和应用

为了提高抗-HIV的检测质量,进行室内质控以鉴别诊断试剂的质量和控制操作误差,试制了抗-HIV室内质控血清,收集抗-HIV诊断试剂盒中阳性对照血清,采用不同品牌、不同批号的诊断试剂检测后,稀释、分装成低值弱阳性,即为室内质控血清,将质控血清放不同温度下保存,考核其稳定性和精密性,并应用于两厂家各3批试剂的检测,结果试制的室内质控血清在-20℃条件下存放5个月,在4℃条件下存放29天稳定性良好,检测结果稳定,该质控血清适宜作抗-HIV检测室内质控使用。     

Rapid method for the determination of ampicillin residues in animal muscle tissues by high-performance liquid chromatography with fluorescence detection

A rapid and sensitive HPLC method was developed for the determination of ampicillin residues in muscle tissues of beef, pork, chicken and catfish. Muscle tissues were blended with a food processor into paste. A 5-g aliquot of the blended tissues was homogenized with 14 ml of 0.01 M phosphate buffer (pH 4.5) using a tissue homogenizer. Proteins were precipitated with the addition of 1 ml trichloroacetic acid (75%, w/v) followed by centrifugation. After filtration, 1 ml of the supernatant was reacted with formaldehyde under acidic and heating conditions. The ampicillin fluorescent derivative was then analyzed by reverse phase HPLC with fluorescence detection. Recoveries of spiked ampicillin at 5, 10 and 20 ng/g were >85%, with coefficients of variation <5%. The limit of detection and limit of quantitation for ampicillin in the tissues were 0.6 ng/g and 1.5 ng/g, respectively. The method is also applicable to the analysis of ampicillin residue in dry milk powder.     

A mouse embryo culture system for quality control testing of human in vitro fertilization and embryo transfer media and fetal cord sera

Swiss white mice were superovulated, mated, and sacrificed to recover two-cell embryos that were cultured in Ham's F-10 supplemented with 15% fetal serum. In 16 experiments, media enriched with fetal bovine serum (FBS) supported blastocyst development from 80% ± 19% (mean ± S.D.) of two-cell embryos. Culture media + FBS was the positive control when 74 batches of heat-inactivated human fetal cord serum (hFCS) were tested. Statistical analyses indicated two distinct populations: 49 hFCS promoted blastocyst formation and 25 hFCS grew fewer blastocysts. In five studies, 35/47 two-cell embryos recovered from mice oviducts in media + FBS and immediately incubated formed blastocysts (75% ± 10%). In six comparison studies where the recovered embryos stood at room temperature for 30 minutes before incubation, only 18/57 (29% ± 21%) became blastocysts. When the colony was housed for 1 week in rooms with Shell No Pest Strips as treatment for mites, only 11/125 two-cell embryos became blastocysts (9%). In contrast, animals housed in quarters decontaminated with chlorine bleach had reduced breeding efficiency and produced fewer two-cell embryos. We conclude that (1) Ham's F-10 + FBS is an excellent positive control to test new batches of hFCS; (2) hFCS that supports blastocyst formation from ≥75% of two-cell embryos is adequate for human use; (3) pesticide treatment of breeding colonies and cooling of murine embryos during harvest both impaired in vitro blastocyst development; and (4) chlorine bleach cleansing of animal quarters reduced the number of successful matings.     

Effect of in ovo application of hydroxyapatite nanoparticles on chicken embryo development,oxidative status and bone characteristics

ABSTRACT

Intensive selection in modern lines of fast-growing chickens has caused several skeletal disorders. Therefore, current research is focused on methods to improve the bones of birds. A new potential solution is in ovo technology using nanoparticles with a high specificity for the bone tissue. Thus, the objective of the present study was to evaluate the effect of in ovo application of hydroxyapatite nanoparticles (HA-NP) in different concentrations (50, 100 and 500 μg/ml colloids) on chicken embryo development, with a particular focus on the oxidative status and bone characteristics of the embryo. The results showed that in ovo treatment with HA-NP did not negatively affect hatchability and body weight. However, bone weight was reduced in 500 μg/ml group. The concentrations of calcium, phosphorus and crude ash were not affected. The modulatory effect of HA-NP was observed on the basis of antioxidative markers – superoxide dismutase, total antioxidant status, malondialdehyde in serum and selected tissues. Glutathione concentration in serum suggested higher metabolic stress. Among bone turnover markers, the concentration of osteocalcin was found to be significantly affected by HA-NP injection. Thus, the in ovo application of HA-NP could modify the molecular responses at the stage of embryogenesis but these changes were not reflected in embryo growth and even slowed down bone development. Nevertheless, the question for the follow-up research is whether in ovo administration of HA-NP would affect the antioxidative status and bone turnover resulting in improved bone conditions and body gain in post hatch chickens.     

A chicken embryo model for the maintenance and amplification of Cryptosporidium parvum and Cryptosporidium baileyi oocysts

Cryptosporidium is a genus of apicomplexan parasites that inhabit the respiratory and gastrointestinal tracts of vertebrates. Research of these parasites is limited by a lack of model hosts. This study aimed to determine the extent to which infection at the embryo stage can enhance the propagation of Cryptosporidium oocysts in chickens. Nine-day-old chicken embryos and one-day-old chickens were experimentally infected with different doses of Cryptosporidium baileyi and Cryptosporidium parvum oocysts. Post hatching, all chickens had demonstrable infections, and the infection dose had no effect on the course of infection. Chickens infected as embryos shed oocysts immediately after hatching and shed significantly more oocysts over the course of the infection than chickens infected as one-day-olds. In chickens infected as embryos, C. baileyi was found in all organs except the brain whereas, C. parvum was only found in the gastrointestinal tract and trachea. In chickens infected as one-day-olds, C. baileyi was only found in the gastrointestinal tract and trachea. Chickens infected as embryos with C. baileyi died within 16 days of hatching. All other chickens cleared the infection. Infection of chickens as embryos could be used as an effective and simple model for the propagation of C. baileyi and C. parvum.     

Effect of sperm motility on human embryo quality in in vitro fertilization

Sperm motility is important for penetration of the zona pellucida, and this parameter has been reported to be the single most important factor determining fertilization rates. As there was no report on the relationship between sperm motility and embryo quality, we investigated the influence of sperm motility on embryo quality in 41 patients with tubal disease and/or obstruction. The patients were either unstimulated or stimulated with clomiphene or clomiphene and human menopausal gonadotrophin. Of 116 oocytes collected, 86 (74.1%) fertilised and cleaved; of these only 44 embryos had clear equal blastomeres without fragmentation (grade 3). Grade 3 embryos were equally distributed through all initial sperm motility categories, and through all categories of sperm concentration after swim-up. The ratio of motile sperm concentration in the initial semen sample to the final sperm concentration after swim-up varied from 0.5 to 67, and grade 3 embryos were distributed randomly from low to high ratios. The pregnancy rate in this series was only 14.6% per replacement. The rate of gestational sacs per embryo replaced was 7.0% (6/86); if “poor” embryos were excluded, the rate was 9.1% (6/66). The absence of correlation between sperm motility and embryo quality is discussed on morphological grounds.     

Gallera method of chick embryo culture in vitro supports better growth compared with original New method

An avian embryo is a valuable model system for vertebrate embryology. Easy availability, accessibility to various developmental stages and amenability of organ fields makes the chick embryo one of the favored model systems. Seminal discoveries regarding organogenesis and vertebrate morphogenesis have been made using chick embryos cultured in vitro . Dennis A.T. New revolutionized chick embryo culture methodology with his development of a single glass ring explantation technique. Many modifications and/or embellishments were introduced after the New era of embryo culture. A double glass ring method for chick embryo culture introduced by Gallera and Nicolet is compared with the original New method and the EASY method in this study. In addition, a video of culture methods is presented as a valuable tool in learning about and/or teaching techniques of chick embryo culture.     

肺炎链球菌荚膜多糖特异性IgG抗体定量ELISA检测及质量控制要求

检测肺炎链球菌荚膜多糖(PPS)特异性抗体的酶联免疫吸附试验多年来经历了两次主要改进。介绍了WHO推荐的人血清抗肺炎链球菌(Streptococcus pneumoniae)荚膜多糖抗体IgG定量ELISA(Pn PS ELISA)检测方法、关键试剂、局限性以及方法验证等内容。ELISA定量检测法,为预防肺炎链球菌的婴幼儿侵袭性疾病提供准确的抗体水平,并对肺炎链球菌疫苗的临床评价提供血清学证据。人血清中肺炎链球菌荚膜多糖抗体IgG是判断肺炎链球菌疫苗效力的重要指标。     

The repetitive use of samples to measure multiple cytokines: the sequential ELISA

The inexpensive and highly effective enzyme-linked immunosorbant assay (ELISA) is widely used for the quantification of biomarkers in a variety of biological samples. The applicability of the standard ELISA is difficult when experiments yield low volume samples. In such studies, the capacity of sample collection system does not meet the sample volume requirements to measure multiple different cytokines by the traditional ELISA protocol. In the modified methodology of the sequential ELISA, samples are re-used in multiple successive cycles, dramatically increasing the number of biomarkers which may be measured. Although the protocols presented to date were developed for quantification of cytokines in either blood plasma or cerebrospinal fluid, the sequential ELISA protocol has wide potential for further uses. When only limited quantities of samples are available for analysis, the sequential ELISA technique based on commercially available antibody pairs can be an attractive alternative to more advanced, costly multiplex methods. Additionally, any laboratory that currently runs traditional ELISAs has all the necessary equipment and reagents to perform the sequential ELISA.     

An ELISA method for the detection and quantification of human heparanase

Heparanase is a mammalian endo-beta-D-glucuronidase that cleaves heparan sulfate side chains at a limited number of sites. Heparanase enzymatic activity is thought to participate in degradation and remodeling of the extracellular matrix and to facilitate cell invasion associated with tumor metastasis, angiogenesis, and inflammation. Traditionally, heparanase activity was well correlated with the metastatic potential of a large number of tumor-derived cell types. More recently, heparanase upregulation was detected in an increasing number of primary human tumors, correlating, in some cases, with poor postoperative survival and increased tumor vascularity. The present study was undertaken to develop a highly sensitive ELISA suitable for the determination and quantification of human heparanase in tissue extracts and body fluids. The assay preferentially detects the 8+50 kDa active heparanase heterodimer vs. the latent 65 kDa proenzyme and correlates with immunoblot analysis of heparanase containing samples. It detects heparanase at concentrations as low as 200 pg/ml and is suitable for quantification of heparanase in tissue extracts and urine.