FIGURE I. Stylized diagram of the immunoglobulin molecule showing derivation of the various fragments used for preparation of antibodies in immunoassay. Immunoassays are a form of macromolecular binding reaction; no covalent chemical bonding is involved. Antibodies interact with their antigens by weak hydrogen bonding and van der Waals forces. Antigen-antibody reactions are dependent on complementary matching shapes (i.e. structural conformity) being assumed by the antibody variable (Fab) regions (see Fig. I) of the immunoglobulin. Almost all polyclonal antibodies used in immunoassay reactions are of the immunoglobulin G (IgG) class. The N-terminal 110 amino acid residues of both the heavy and light chains of the immunoglobulin molecules are variable in sequence and interact to form the antigen binding site. About 30 amino acids are potentially available as antigen contact residues, but X-ray crystallographic studies have shown that a maximum of only 17 amino acids are directly involved in binding contact. Nevertheless, this variability gives rise to a vast array of different

https://journals.sagepub.com/doi/pdf/10.1177/000456329903600603

Interference in immunoassay

The production of antibodies (Abs) in chickens and the extraction of specific Abs from egg yolk (IgY Abs) are increasingly attracting the interest of the scientific community, as demonstrated by th...

Chicken Egg Yolk Antibodies (IgY-technology): A Review of Progress in Production and Use in Research and Human and Veterinary Medicine:

Composition and Extraction of Egg Components.- Composition and Structure of Hen Egg Yolk.- Low-density Lipoproteins (LDL) or Lipovitellenin Fraction.- High-density Lipoproteins (HDL) or Lipovitellin Fraction.- Phosvitin.- Livetin Fractions (IgY).- Lysozyme.- Ovotransferrin.- Ovalbumin and Gene-Related Proteins.- Ovomucin.- Riboflavin-Binding Protein (Flavoprotein).- Avidin.- Proteases.- Antiproteases.- Minor Proteins.- Structure and Formation of the Eggshell.- Eggshell Matrix Proteins.- Function of Eggshell Matrix Proteins.- Use of Egg Compounds for Human Nutrition.- Nutritional Evaluation of Egg Compounds.- Concepts of Hypoallergenicity.- Egg Enrichment in Omega-3 Fatty Acids.- Enrichment in Vitamins.- Enrichment in Selenium and Other Trace Elements.- Use of Eggs for Human/Animal Health and Biotechnology.- Compounds with Antibacterial Activity.- Egg-Protein-Derived Peptides with Antihypertensive Activity.- Use of IgY Antibodies in Human and Veterinary Medicine.- Egg Compounds with Antioxidant and Mineral Binding Properties.- Use of Lecithin and Lecithin Fractions.- Extraction of Several Egg Compounds at a Pilot Scale.- Use of Egg Compounds for Cosmetics and Pharmaceutics.- Use of Egg Compounds for Cryoprotection of Spermatozoa.- Egg-Protein-Based Films and Coatings.- Magnetic Particles for Egg Research.- Avidin-Biotin Technology.

http://www.agrifs.ir/sites/default/files/5Bioactive%20Egg%20Compounds.pdf

Bioactive egg compounds

Chicken antibodies: taking advantage of evolution: a review

The objective of this research was to evaluate the effect of early feeding on the development of the immune system in broiler chicks. A hydrated nutritional supplement formulated specifically for the first 2 to 3 days of post-hatch life was provided to the chicks on the day of hatch and the 2 subsequent days. The nutritional content of this supplement was optimized to achieve maximum performance at 6 wk following ad libitum consumption of starter feed and water. Control hatchlings received neither feed nor water. After the initial treatment, all birds were fed the same corn-soy diet ad libitum. Immune development was assessed by measuring bursa weight, biliary immunoglobulin A (IgA) levels, appearance of germinal centers in the cecal tonsils, and resistance to an oral challenge with coccidial oocysts. Data indicate that provision of the optimum balance of nutrients immediately after hatch result in heavier bursa weights, earlier appearance of biliary IgA and germinal centers, and an improved resistance to disease challenge.

Early Feeding and Development of the Immune System in Neonatal Poultry

Chicken antibodies: a tool to avoid interference by complement activation in ELISA.

Chicken antibodies have several advantages over mammalian antibodies due to the phylogenetical differences between birds and mammals, resulting in an increased sensitivity and a decreased background in many immunological assays. So far, there has been a very limited use of avian antibodies. This is probably partly due to tradition but also because there are very few optimized methods for the labelling of chicken antibodies. We report upon the suitable conditions for peroxidase-labelling of chicken antibodies with a modified periodate method.

https://www.tandfonline.com/doi/pdf/10.1080/09540109999906

Peroxidase-labelling of Chicken Antibodies

Background Balanced transfusions, including platelets, are critical for bleeding patients to maintain hemostasis. Many rural hospitals have no or limited platelet inventory, with several hours of transport time from larger hospitals. This study aimed to evaluate the feasibility of using cryopreserved platelets that can be stored for years, in remote hospitals with no or limited platelet inventory. Material and methods Three remote hospitals participated in a prospective study including adult bleeding patients where platelet transfusions were indicated. Cryopreserved platelets were prepared in a university hospital, concentrated in 10 ml, transported on dry ice, and stored at −80°C at the receiving hospital. At request, the concentrated platelet units were thawed and diluted in fresh frozen plasma. The indications, blood transfusion needs, and laboratory parameters pre- and post-transfusion, as well as logistics, such as time from request to transfusion and work efforts in preparing cryopreserved platelets, were evaluated. Results Twenty-three bleeding patients were included. Nine patients (39%) were treated for gastrointestinal bleeding, five (22%) for perioperative bleeding, and four (17%) for trauma bleeding. The transfusion needs were 4.9 ± 3.3 red blood cell units, 3.2 ± 2.3 plasma units, and 1.9 ± 2.2 platelet units, whereof cryopreserved were 1.5 ± 1.1 (mean ± SD). One patient had a mild allergic reaction. We could not show the difference in laboratory results between pre- and post-transfusion of the cryopreserved units in the bleeding patients. The mean time from the order of cryopreserved platelets to transfusion was 64 min, with a range from 25 to 180 min. Conclusion Cryopreserved platelets in remote hospitals are logistically feasible in the treatment of bleeding. The ability to have platelets in stock reduces the time to platelet transfusion in bleeding patients where the alternative often is many hours delay. Clinical effectiveness and safety previously shown in other studies are supported in this small feasibility study.

/pdf/cryopreserved-platelets-in-bleeding-management-in-remote-3fgvtnr0.pdf

Per-Olof Forsberg

Papers

Chicken antibodies: taking advantage of evolution: a review

Chicken antibodies: a tool to avoid interference by complement activation in ELISA.

Peroxidase-labelling of Chicken Antibodies

Cryopreserved platelets in bleeding management in remote hospitals: A clinical feasibility study in Sweden