The migration of larval Toxocara canis in mice. I. Migration through the intestine in primary infections

Toxocara canis second stage larvae (L2) hatched in the stomach of mice and within 2 h reached all parts of the small intestine, the posterior half being the preferred site for larval penetration. Following penetration at the base of crypts of leiberkuhn they followed tortuous routes in the lamina propria, and entered the tunica muscularis obliquely. Larvae only appeared to be arrested in their migration in the submucosa and lamina propria by an inflammatory reaction composed mainly of lymphocytes and eosinophils. Larvae were seen entering and within lymphatic vessels as well as the peritoneal cavity and invasion of the vascular system followed though actual penetration of intestinal blood vessels was not seen. Proteolytic enzyme activity was detected in culture media in which L2 larvae were maintained.     

Isolation and functional analysis of normal canine blood monocytes and resident alveolar macrophages

The percentage of mononuclear phagocytes bearing the Fc receptor for immunoglobulin G, the percentage of cells phagocytic for Candida albicans and latex particles, and the phagocytic index for blood monocytes and alveolar macrophages from healthy dogs are reported. Blood monocytes were concentrated by density-gradient centrifugation, whereas alveolar macrophages were obtained in high yield by bronchoalveolar lavage. Adherent populations of those cells were used for functional assays after repeated washing to remove nonadherent cells. A greater percentage of adherent alveolar macrophages than adherent blood monocytes showed evidence of the Fc receptor for immunoglobulin G. Similarly, adherent alveolar macrophages showed significantly greater phagocytic ability, as measured by percent phagocytic cells and phagocytic index, using C albicans and latex particles, than did adherent canine blood monocytes.