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  • Author or Editor: Massimo Castagnaro x
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SUMMARY

Twelve biotinylated lectins and an avidin-biotin-peroxidase method were used to detect and localize specific carbohydrate residues on formalin-fixed, paraffin-embedded female canine mammary gland sections. Histologic sections from 3 lactating and 7 nonlactating mixed-breed dogs (age 5.6 ± 0.35 years) were incubated with Arachis hypogea agglutinin (peanut agglutunin; pna), Concanavalia ensiformis agglutinin (conA), Dolichos biflorus agglutinin (dba), Glycine max agglutinin (sba), Griffonia simplicifolia agglutinin-I (gs-I), Lens culinaris agglutinin (lca), Lycopersicon esculentum agglutinin (lea), Phytolacca americana mitogen (pokeweed mitogen; pwm), Ricinus communis agglutinin-I and-II (rca-I and -II), Triticum vulgaris (wga), and Ulex europaeus agglutinin-I (uea-I). Each lectin had a specific binding pattern, except sba and dba.

In nonlactating glands, pna, conA, lea, and uea-I stained duct cells in a linear-binding pattern, with a mean percentage of positive ducts per section of 28.7 (± 0.6), 65.7 (± 0.3), 100 (± 0), and 8.4 (± 0.2), respectively. Strong apical, lateral, basal, and cytoplasmic positivity on duct cells was seen after incubation of the sections with rca-I, rca-II, and wga in all ducts. In acinar cells, the binding pattern and the staining distribution of all the lectins studied were similar to those in duct cells. However, for pna, conA, and uea-I, the mean percentage of positive lobules per section was 33.7 (± 0.9), 62 (± 0.5), and 10.5 (± 0.2), respectively.

In glands from lactating dogs, conA and uea-I did not stain. The cytoplasm of all myoepithelial cells was moderately stained with rca-I, rca-II, and wga. Endothelial cells stained with gs-I, pwm, rca-I, rca-II, wga, conA, and lca. The extracellular matrix, especially the periacinar and periduct regions, and the interstitial fibroblasts were positive for lca, rca-I, rca-II, and wga. Peripheral unmyelinated nerve fibers of the nipple were strongly positive for GS-I, pwm, rca-I, rca-II, and wga. Some of the lectins used (ie, pna, conA, uea-I, gs-I, pwm, and lea) appear to have selective staining of mammary gland structures that seems to be correlated with various physiologic functions. The contrasting binding pattern of lectins specific for the same sugar indicates a lack of knowledge of interactions between lectins and carbohydrate residues in tissue sections.

Free access
in American Journal of Veterinary Research

SUMMARY

The toxicity of zinc ethylene-bis-dithiocarbamate (zineb), a widely used fungicide, was studied in four 4-week-old Friesian calves with immature rumen function. Calves were first subjected to liver biopsy, and thereafter, 3 of them were orally administered 200 mg of zineb/kg of body weight daily for 80 days, whereas the fourth calf served as control and remained untreated. Clinical, hematologic, and pathologic (including ultrastructural) findings were recorded. The distribution in body fluids and tissues of the parent compound and one of its main metabolites, ethylenethiourea (etu), also was examined. Treated calves had unthrifty appearance and reduction in weight gain. They also had remarkable impairment of thyroid function, as reflected by reduction in serum concentrations of triiodothyronine and thyroxine and increase in weight of the thyroid gland associated with epithelial vacuolization and foci of hyperplasia. Moderate increase in liver glycogen content and impairment in maturation of germ cells were recorded consistently. Whereas zineb was widely distributed in body tissues, etu accumulated mainly in the liver and the thyroid gland, although noticeable concentrations also were attained in muscle. Data were consistent with involvement of etu mainly in the pathogenesis of thyroid gland lesions, and indicate that unweaned calves given zineb develop a clinicopathologic syndrome that does not differ qualitatively from that already described in adult cattle exposed to zineb.

Free access
in American Journal of Veterinary Research