A Review of the Comparative Anatomy, Histology, Physiology and Pathology of the Nasal Cavity of Rats, Mice, Dogs and Non-human Primates. Relevance to Inhalation Toxicology and Human Health Risk Assessment.

There are many significant differences in the structural and functional anatomy of the nasal cavity of man and laboratory animals. Some of the differences may be responsible for the species-specific nasal lesions that are often observed in response to inhaled toxicants. This paper reviews the comparative anatomy, physiology and pathology of the nasal cavity of the rat, mouse, dog, monkey and man, highlighting factors that may influence the distribution of nasal lesions. Gross anatomical variations such as turbinate structure, folds or grooves on nasal walls, or presence or absence of accessory structures, may influence nasal airflow and species-specific uptake and deposition of inhaled material. In addition, interspecies variations in the morphological and biochemical composition and distribution of the nasal epithelium may affect the local tissue susceptibility and play a role in the development of species-specific nasal lesions. It is concluded that, while the nasal cavity of the monkey might be more similar to that of man, each laboratory animal species provides a model that responds in a characteristic and species-specific manner. Therefore for human risk assessment, careful consideration must be given to the anatomical differences between a given animal model and man.

Serum amyloid A and transferrin in chicken. A preliminary investigation of using acute-phase variables to assess diseases in chickens.

The concentrations of serum amyloid A protein (SAA) and transferrin in blood samples from broilers in various stages of natural Staphylococcus aureus infection, from healthy counterparts, and from turpentine- or saline-injected pullets were measured using sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE), immunoblotting, and densitometry. SAA was not detected in healthy chickens but was detected in turpentine-injected pullets and in S. aureus-infected broilers. Relative percentages of transferrin in turpentine- and saline-injected pullets were not different. Broilers with a S. aureus infection had a two-fold higher transferrin level than did their unaffected counterparts. There was also a difference between the transferrin levels of healthy broilers and healthy pullets, which indicates that other variables, such as breed or breeding conditions, may influence the transferrin level. This preliminary study showed that SAA is an acute-phase protein and a more reliable variable for diagnosing lesions in chickens than transferrin.

Arthropathic and amyloidogenic Enterococcus faecalis infections in brown layers: A study on infection routes.

Intravenous, intra-articular and intraperitoneal inoculation of 6-week-old brown-layer pullets with an arthropathic and amyloidogenic strain of Enterococcus faecalis resulted in amyloid arthropathy, while intramuscular, oral and intratracheal inoculation did not. Oral inoculation of 1-day-old chickens did not cause any pathology. However, intramuscular inoculation with 106 colony forming units resulted in severe growth retardation and arthritis in 60% of the birds, and amyloid arthropathy in approximately 40%. In egg transmission studies, neither egg dipping nor inoculation of the air chamber with E. faecalis reproduced the condition, although a few chicks became septicaemic. Yolk sac inoculation of 6-day-old embryos caused embryonic death within 2 days. In contrast, egg albumen inoculation with E. faecalis led to arthritis in one of six of the progeny, indicating the possibility that vertical transmission of E. faecalis by the oviductal route could lead to arthritis. The presence of antibodies to E. faecalis was confirmed by enzyme-linked immunosorbent assay in 14/15 of experimental birds that had developed arthritis.