Chicken egg yolk antibodies (IgY) for detecting circulating antigens of Schistosoma japonicum

BackgroundIgY isolated from egg yolk has been widely used in immunodiagnostic tests, including tests to detect circulating antigen (soluble egg antigen or SEA) of Schistosoma japonicum.ResultsA sandwich ELISA was established using a combination of anti-S. japonicum SEA-IgY polyclonal antibodies and IgM monoclonal antibodies. To explore sensitivity and specificity of the sandwich ELISA, serum samples from 43 patients infected with S. japonicum were tested. All acute cases and 91.3% of the chronic cases showed a positive reaction. Only 5% of the control sera from healthy persons gave a positive response. Cross-reactions with antibodies to nine other parasites were rare.ConclusionThe developed immunoassay is reasonably sensitive and specific. It could be used for field research and treatment efficacy assessments.     

Efficient production of chicken egg yolk antibodies against a conserved mammalian protein

The egg yolk of immunized chicken is a rich and inexpensive source of specific polyclonal antibodies. In this paper we show that 20-30 micrograms of a highly conserved mammalian protein, as exemplified by proliferating cell nuclear antigen, are sufficient to induce an immune response. Immunoblot analysis revealed that specific antibodies appeared 20 days after immunization, reached a plateau after 30 days, and remained high until at least day 81. A total amount of 4 g immunoglobulin was extracted from 62 eggs of one immunized hen, yielding approximately 130 mg of specific antibodies.     

Chicken egg yolk anti-asialoGM1 immunoglobulin (IgY): an inexpensive glycohistochemical probe for localization of T-antigen in human colorectal adenocarcinomas.

A egg yolk polyclonal IgY has been prepared by immunization of white leghorn chickens with small unilamellar liposomal asialoGM1. The newly prepared anti-asialoGM1 IgY has been characterized to be specific toward the terminal carbohydrate moiety of asialoGM1, and has no cross reactivity to its sialylated counterpart (ganglioside, GM1) as evidenced by immunochromatographic studies. General glycohistochemical methods along with antigen specific lectin and immunohistochemical staining using anti-asialoGM1 IgY were used to study the expression of Thomsen-Friedenreich (T-) disaccharide antigen in human colorectal adenocarcinoma tissues. The expression of T-antigen in colon cancer tissue was detected by two T-disaccharide specific probes, chicken anti-T-yolk antibody (IgY) and Artocarpus integrifolia lectin (AIL) and was found to be more pronounced in both the secreted mucin as well as the cytoplasmic mucin deposits. These immunochemical detection methods for T-antigen showed a weaker correlation with other glycostaining methods using, alcian-blue/periodic acid-Schiff (AB-PAS) and high iron diamine (HID). However, a general enzymatic staining for galactose and galactosamine containing glycoconjugates, by galactose oxidase-Schiff method, showed a good correlation with T-antigen detection. While the T-beta specific anti-asialoGM1 could localize T-antigen in 11 of 13 (84%) human colorectal adenocarcinoma tissue sections tested, the T-alpha specific AIL could localize the T-antigen in only 6 of the tissues (46%). These observations confirm previously reported findings, of the prevalence of T-beta conformation in colon cancer, that binds significantly more with the anti-asialoGM1 IgY than with the T-alpha specific AIL. Hence, both anti-T IgY and the AIL immunohistochemical probes may have useful diagnostic value because of the ease of preparation and cost effectiveness, but the T-beta specific anti-asialoGM1 probe (IgY) would have a better prognostic value in colon adenocarcinomas.     

Efficient production, purification, and application of egg yolk antibodies against human HLA-A*0201 heavy chain and light chain (beta2m)

The importance of eggs as a source of specific antibodies is well recognized. Egg yolk contains 8--20mg immunoglobulins (IgY) per milliliter. However, the major problem in separating IgY is to remove the high concentrations of lipids in egg yolk. We first used water dilution method to get the supernatant containing IgY, then purified the antibody by caprylic acid-ammonium sulfate method, and obtained specific antibody with satisfactory purity and activity. By comparison of these several methods, each has its advantages, one can be chosen to purify IgY according to practical need. The purified IgY produced by the immunized chickens can stain the human peripheral blood mononuclear cell effectively when labeled with fluorescent FITC.     

Biomarkers in veterinary medicine: establishing a new international forum for veterinary biomarker research

Background: Mid-regional pro-atrial natriuretic peptide (MR-proANP) increases with severity in community-acquired pneumonia (CAP). We investigated whether changes of MR-proANP correlated to bacteremia.

Methods: 392 adult patients with CAP visiting emergency department from a prospective observational multicenter study.

Results: MR-proANP levels increased in patients with positive bacteremia (92.8 pmol/L vs. 84.3 pmol/L, p?=?0.04). Performance of MR-proANP to detect bacteremia (0.60) was equivalent to CRP (0.59) but less accurate than PCT (0.69).

Conclusion: MR-ANP poorly predicts bacteremia in CAP patients.     

木耳属研究进展

简要概述了木耳属真菌在物种资源、系统发育和主要栽培类群遗传多样性方面的研究现状及进展。目前木耳属研究存在的主要问题是对该属物种资源缺乏系统研究,不同种类间系统发育关系不清楚,重要栽培种类黑木耳野生种群遗传多样性尚未分析。今后该属研究的主要方向是对上述问题的解决。     

红菇属研究进展

红菇属Russula是一类具有较高经济和研究价值的食药用真菌,部分种类有毒。从红菇属的资源和分类、分子系统学、遗传多样性与应用研究等方面,本文对近年的研究进展进行了综述。红菇属研究存在的主要问题是形态特征记述误差较大导致的鉴定不准确,现有分子系统学研究和遗传多样性研究只涉及了少数种类的单基因片段,我国已报道的大量原初描述于欧洲和北美洲的种名是否在我国有分布尚存在争议,解决上述问题是今后红菇属研究的主要方向。     

Inhibition of growth and adhesion ofHelicobacter pylori using egg yolk antibodies

Helicobacter pylori is known as a key pathogen for chronic gastric and duodenal ulcers. Egg yolk antibody, IgY produced from chicken immunized withH. pylori antigen was tested for the inhibition of growth and adhesion ofH. pylori to gastric epithelial cell, AGS. The colony forming ofH. pylori was repressed by 30% using 1 mg/mL of IgY while that ofE. coli was only 7% with the same amount of IgY, which showed the growth inhibition ofH. pylori was mainly due to the specific interaction between IgY andH. pylori. The inhibition ofH. pylori adhesion to AGS was as high as 90% using 0.5 mg/mL of antibody only. More than 80% ofH. pylori attached to AGS could be detached treating with the same amount of IgY for one and a half hr. However, this effect was severely dependant on theH. pylori strains tested. The strain used for immunization of chicken was very sensitive to the antibody treatment but changing the test strain generally showed a variation in adhesion inhibition between 15 and 80%. Further studies are necessary to employ the egg yolk antibodies for the treatment ofH. pylori in vivo.     

The use of essential oils in veterinary ectoparasite control: a review

There is a growing body of evidence indicating the potential value of essential oils as control agents against a range of arthropod ectoparasites, particularly lice, mites and ticks. Toxicity has been demonstrated following immersion and physical contact with treated surfaces, as well as after exposure to the vapour of these oils; the last of these factors implies that there is a neurotoxic, rather than simply a mechanical, pathway in their mode of action. However, the volatile nature of essential oils suggests that their residual activity is likely to be short‐lived. A possible advantage of essential oils over conventional ectoparasite treatments may refer to their reported ovicidal efficacy, although it is unclear whether this results from neurotoxicity or mechanical suffocation. There are many difficulties in comparing the findings of existing studies of essential oil toxicity. One major issue is the wide variation among batches in the relative concentrations of oil constituents. A second issue concerns the fact that many experimental designs make it difficult to confirm that the effect seen is attributable to the oil; in many cases inappropriate controls mean that the effects of the excipient on mortality cannot be distinguished. Hence, it is important that an excipient‐only control is always included in these bioassays. Furthermore, in direct contact assays, when attempting to identify the toxicity pathway of the essential oil tested, it is important to include a hydrophobic control. Without this, it is impossible to distinguish simple mechanical effects from neurological or other cellular toxicity. The use of essential oils in the control of veterinary ectoparasites is an area which holds considerable potential for the future and research into their use is still at an early stage. More extensive field trials, the standardization of components, the standardization of extraction, the standardization of good experimental design, mammalian toxicology profiling and excipient development, as well as further investigation into the residual activities and shelf‐lives of these oils are all required to allow the full realization of their potential.     

Production and purification of human indoleamine 2,3-dioxygenase (HuIDO) protein in a baculovirus expression system and production and characterization of egg yolk antibody against the purified HuIDO

The human indoleamine 2,3-dioxygenase (HuIDO) baculoviral construct, for expression of HuIDO protein with a hexa-histidine and FLAG (DYKDDDDK) tag, was produced using the BacPAK Baculovirus Expression System. HuIDO baculovirus was used to infect Sf21 insect cells to produce functionally active protein in large amounts. Conditions for protein purification by metal affinity chromatography were determined and optimized. Addition of haemin ensured optimal activity of the purified heme-containing oxygenase. The soluble purified protein was used to immunize a chicken to produce large quantities of polyclonal IgY against HuIDO. The anti-HuIDO IgY antibody specifically detected HuIDO produced by a range of cell types including transfectants and native HuIDO expression induced in IFN-gamma-stimulated cells. The antibody detected HuIDO in cell lysates by western blotting and in the cytoplasm of cells by microscopy. The antibody was unable to block the function of the enzyme, indicating that this antibody binds outside the active site of HuIDO.     

Lifetime egg production and egg mortality in the damselflyPyrrhosoma nymphula (Sulzer) (Zygoptera: Coenagrionidae)

Artificial oviposition sites were used to estimate egg deposition rates in the field. Females laid an average of 10.76 eggs/minute with a mean duration of 22.81 minutes, giving an average clutch size of 245 eggs. Since one mating corresponded to one clutch of eggs, lifetime mating success was used as a measure of the number of clutches produced. Mean lifetime clutch production was 5.91 clutches per female, equating to 1447 eggs per female per lifetime. Eggs were hatched in the laboratory at temperatures comparable with those in the field. Hatching was highly synchronised and the overall hatching success was 75.1%. Causes of egg mortality in the laboratory were limited to infertility and unhatchability. Since no other sources of egg mortality could be found at the study site, this value was a good reflection of hatching success in the field. Lifetime egg production and hatching success were used to estimate the number of viable offspring produced per female, giving a higher order estimate of reproductive success than has previously been published for a zygopteran.     

Application of chicken egg yolk immunoglobulins in the control of terrestrial and aquatic animal diseases: a review

Oral administration of chicken egg yolk immunoglobulin (IgY) has attracted considerable attention as a means of controlling infectious diseases of bacterial and viral origin. Oral administration of IgY possesses many advantages compared with mammalian IgG including cost-effectiveness, convenience and high yield. This review presents an overview of the potential to use IgY immunotherapy for the prevention and treatment of terrestrial and aquatic animal diseases and speculates on the future of IgY technology. Included are a review of the potential application of IgY for the treatment of livestock diseases such as mastitis and diarrhea, poultry diseases such as Salmonella, Campylobacteriosis, infectious bursal disease and Newcastle disease, as well as aquatic diseases like shrimp white spot syndrome virus, Yersina ruckeri and Edwardsiella tarda. Some potential obstacles to the adoption of IgY technology are also discussed.     

抗中华眼镜蛇毒鸡卵黄抗体的制备及其效价测定

目的探索免疫鸡制备高效价抗眼镜蛇毒抗体的新方法。方法用中华眼镜蛇原毒作抗原免疫22周龄的莱航母鸡,水溶法粗提抗体,DEAE Sepharos FF柱纯化,切向流超滤膜脱盐及浓缩,免疫电泳及双向免疫扩散法进行鉴定及效价测定,采用BCATMProte in Assay K it测定蛋白含量。结果鸡卵黄经水溶法的粗提物与中华眼镜蛇毒即有较明显沉淀反应,其效价随着纯度的提高而增强。将马源性抗血清的蛋白质含量调至与浓缩的IgY相同(2mg/m l),经双向免疫扩散及免疫电泳鉴定,该抗体不但对中华眼镜蛇毒有特异性结合,与孟加拉眼镜蛇毒亦有较强的交叉免疫活性,其效价较马抗眼镜蛇毒血清高4倍以上。结论用中华眼镜蛇原毒制备的IgY抗体,其效价较马抗血清有显著提高,并与孟加拉眼镜蛇毒有高度交叉免疫。本实验为抗眼镜蛇IgY的应用及其它抗蛇毒IgY的制备奠定了基础。     

Affinity purification of egg yolk immunoglobulins (IgY) with a stable synthetic ligand

Chicken IgY (egg yolk immunoglobulin) is a functional equivalent of mammalian IgG. Traditional methods for IgY purification involve multi-step procedures that result in low recovery of IgY. After a large scale screening of our 700-member synthetic ligand library synthesized by epichlorohydrin and cyanuric chloride methods, a high efficiency ligand of IgY was found. By one-step purification with this ligand, the purity of IgY could reach 92.1%, and the recovery of IgY could reach 78.2%. This synthetic ligand had a higher binding capacity of 74.8 mg IgY/ml and had no negative effects on immunoreactivity. Remarkably, this ligand was also highly stable and could resist 1M NaOH, thus having great potential for the industrial-scale production of IgY.     

抗哇巴因鸡蛋黄IgY与兔抗体IgG在酶联免疫检测中的比较

目的：探讨提高内源性哇巴因（EO）检测方法的准确性及特异性,为哇巴因的研究打下基础。方法：分别制备出鸡蛋黄抗哇巴因多克隆抗体及兔抗体。然后采用酶联免疫吸附法（ELISA）比较两种抗体检测内源性哇巴因的准确性及特异性。结果：采用IgY检测EO的平均批内变异系数为2．03％,批间变异系数为2．34％。兔抗体IgG则分别为2．83％、3．29％;两者均与氢化可的松及地塞米松无交叉结合反应,与西地兰和地高辛分别存在3．45％vs5．95％、3．20％vs5．20％的交叉反应。结论：IgY比兔抗体ELISA检测内源性哇巴因的特异性及准确性较高。