This chapter presents basic concepts related to avian clinical biochemistry. Avian medicine and surgery is recognized as an official specialty in veterinary medicine in three continents: Europe, Australia, and North America. The increasing demand for veterinary care for individual birds with a high sentimental or economical value and efforts to conserve endangered species facilitated this awareness. The introduction of micromethods in clinical laboratories and the public demand for veterinary care for individual birds have removed many obstacles of this field. This chapter begins with discussing how blood samples of birds can be collected in the most efficient way. The chapter then discusses starvation, flight, and postprandial effects. The chapter also elaborates the biochemistry of plasma proteins, renal function, and hepatobiliary disease in birds. The chapter emphasizes that all efforts should be made to obtain a blood sample before any treatment is given. Treatments administered before samples are collected may severely affect plasma chemical values, which may jeopardize a correct diagnosis at a later stage. The time interval between restraint and blood sampling should be kept to a minimum to prevent stress-associated changes in clinical chemistry parameters. Blood samples should be obtained before an extensive clinical examination is performed to avoid iatrogenic changes in the samples.

Avian Clinical Biochemistry

The acute phase response is a complex systemic early-defense system activated by trauma, infection, stress, neoplasia, and inflammation. Although nonspecific, it serves as a core of the innate immune response involving physical and molecular barriers and responses that serve to prevent infection, clear potential pathogens, initiate inflammatory processes, and contribute to resolution and the healing process. Acute phase proteins, an integral part of the acute phase response, have been a focus of many applications in human diagnostic medicine and recently have been identified in common animal species. Potential applications to diagnosis, prognosis, assessment of animal health, and laboratory animal welfare are readily apparent.

Acute phase response in animals: a review.

The acute phase response is a nonspecific inflammatory reaction of the host that occurs shortly after any tissue injury. The response includes changes in the concentration of plasma proteins called acute phase proteins (APPs), some of which decrease in concentration (negative APPs), such as albumin or transferrin, and others of which increase in concentration (positive APPs), such as C-reactive protein, serum amyloid A, haptoglobin, alpha-1-acid glycoprotein, and ceruloplasmin. Most positive APPs are glycoproteins synthesized mainly by hepatocytes upon stimulation by proinflammatory cytokines and released into the bloodstream. The acute phase response and clinical application of monitoring APPs in dogs and cats are reviewed in this article, including biochemical characteristics, assays developed for each individual APP, and preanalytic and analytic factors influencing APP results that should be taken into account for proper and adequate clinical interpretation. In addition, the diagnostic use of APPs and their possible application in monitoring treatment, which can be considered one of the most interesting and promising practical applications of these proteins, will be discussed. Finally, challenges and future developments of APPs in dogs and cats will be considered, because it is expected that new and cheaper automated assays for determination of the main APPs in small animals will contribute to a wider use of these proteins as biomarkers of infection and inflammatory lesions.

Acute phase proteins in dogs and cats: current knowledge and future perspectives

Organotin(IV)n+ complexes formed with biologically active ligands: equilibrium and structural studies, and some biological aspects

Tooth enamel is a unique mineralized tissue in that it is acellular, is more highly mineralized, and is comprised of individual crystallites that are larger and more oriented than other mineralized tissues. Dental enamel forms by matrix- mediated biomineralization. Enamel crystallites precipitate from a supersaturated solution within a well-delineated biological compartment. Mature enamel crystallites are comprised of non-stoichiometric carbonated calcium hydroxyapatite. The earliest crystallites appear suddenly at the dentino-enamel junction (DEJ) as rapidly growing thin ribbons. The shape and growth patterns of these crystallites can be interpreted as evidence for a precursor phase of octacalcium phosphate (OCP). An OCP crystal displays on its (100) face a surface that may act as a template for hydroxyapatite (OHAp) precipitation. Octacalcium phosphate is less stable than hydroxyapatite and can hydrolyze to OHAp. During this process, one unit cell of octacalcium phosphate is converted into two unit cell...

Molecular Mechanisms of Dental Enamel Formation

T.B. Farver, Concepts of Normality in Clinical Biochemistry. J.G. Hauge, DNA Technology in Diagnosis, Breeding, and Therapy. J.J. Kaneko, Carbohydrate Metabolism and Its Diseases. M.L. Bruss, Lipids and Ketones. J.J. Kaneko, Serum Proteins and the Dysproteinemias. L.J. Gershwin, Clinical Immunology. J.W. Harvey, The Erythrocyte: Physiology, Metabolism, and Biochemical Disorders. J.J. Kaneko, Porphyrins and the Porhyrias. J.E. Smith, Iron Metabolism and Its Disorders. W.J. Dodds, Hemostasis. J.G. Zinkl and M.B. Kabbur, Neutrophil Function. J.W. Kramer and W.E. Hoffmann, Clinical Enzymology. B.C. Tennant, Hepatic Function. D.F. Brobst, Pancreatic Function. W.E. Hornbuckle and B.C. Tennant, Gastrointestinal Function. G.H. Cardinet III, Skeletal Muscle Function. D.R. Finco, Kidney Function. G.P. Carlson, Fluid, Electrolyte, and Acid-Base Balance. J.A. Mol and A. Rijnberk, Pituitary Function. A. Rijnberk and J.A. Mol, Adrenocortical Function. J.J. Kaneko, Thyroid Function. L-E. Edqvist and M. Forsberg, Clinical Reproductive Endocrinology. T.J. Rosol and C.C. Capen, Calcium-Regulating Hormones and Diseases of Abnormal Mineral (Calcium, Phosphorus, Magnesium) Metabolism. R.B. Rucker and J.G. Morris, The Vitamins. M. Haskins and U. Giger, Lysosomal Storage Diseases. B.R. Madewell, Tumor Markers. C.S. Bailey and W. Vernau, Cerebrospinal Fluid. J.R. Turk and S.W. Casteel, Clinical Biochemistry in Toxicology. W.F. Loeb, Clinical Biochemistry of Laboratory Rodents and Rabbits. J.T. Lumeij, Avian Clinical Biochemistry. Appendixes. Index.

Clinical biochemistry of domestic animals

Summary: Rhesus monkey infants were injected subcutaneously at birth with 12 to 100 μmol of tin-protoporphyrin IX, a competitive inhibitor of microsomal heme oxygenase. The elevated unconjugated serum bilirubin levels of the neonates receiving this metalloporphyrin rapidly declined to near adult levels by 24–30 h. Control neonates which received an injection of saline exhibited normal physiologic hyperbilirubinemias of from 3–6 mg/dl by 12–24 h as expected. These studies establish the effectiveness of tin-protoporphyrin IX in depressing bilirubin production and preventing physiologic hyperbilirubinemia in simian neonates. Two of six animals receiving the metalloporphyrin exhibited signs of toxicity.

Prevention of neonatal hyperbilirubinemia in rhesus monkeys by tin-protoporphyrin.

https://aasldpubs.onlinelibrary.wiley.com/doi/pdf/10.1002/hep.1840030417

Extrahepatic Biliary Atresia in a Rhesus Monkey (Macaca mulatto)

Gallbladder (GB) bile of most cyclostomes, elasmobranchs, and teleosts contains appreciable amounts of biliverdin (BV) and bilirubin (BR) conjugates with lesser amounts of unconjugated BR in certain species. Certain elasmobranch and teleost species have been reported to have primarily BV or BR in bile. The appearance of the enzyme BV reductase, which converts BV to BR in mammals, evolved quite early in the evolution of vertebrate species; however, exceptions exist in certain fishes, amphibians, reptiles, and mammals whose bile contains primarily BV. Nearly all analytical studies on bile pigment composition in fishes to date have utilized only GB bile, which may or may not always be representative of the pigments excreted in freshly collected hepatic duct bile. The concentration of BV and BR in GB bile of fishes increases markedly during prolonged fasts. From the limited data currently available, there appears to be no systematic development from primitive to advanced forms in the appearance of certain bile pigments in fishes. While bile of most aquatic species contains appreciable amounts of both BV and BR, it is interesting that the bile of most terrestrial avian and reptilian forms contains primarily BV. The serum of fishes, except for certain bony species such as eels (Anguilleformes) and cottids (Scorpaeniformes), is a light yellow color due to the presence of BR and is similar to that observed in higher vertebrates. Serum from certain eels and cottids is bluish green in color due to the presence of a variety of chromoproteins that contain BV firmly bound as the prosthetic group.

Charles E. Cornelius

Papers

Clinical biochemistry of domestic animals

Prevention of neonatal hyperbilirubinemia in rhesus monkeys by tin-protoporphyrin.

Extrahepatic Biliary Atresia in a Rhesus Monkey (Macaca mulatto)

Bile pigments in fishes: a review

Bile pigments in gallbladder and freshly-secreted hepatic duct bile from fed and fasted rainbow trout, Oncorhynchus mykiss.