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Biomedical subjects

J Ralston

Publications and source records attributed to J Ralston.

29 records · Page 2Linked to original sources

Clinicopathological features of a congenital murine model of ocular toxoplasmosis.

Sequential clinical examination was carried out upon the eyes of mice that had been infected in utero with Toxoplasma gondii. Three patterns of clinical disease were seen. First, crystalliform cataracts, which either remained unchanged in character or occasionally became more extensive, were observed. Second, acute uveitis occurred in a small proportion of eyes, progressing into a chronic inflammatory disease with secondary opaque cataract. The third pattern comprised multiple discrete foci of deep retinal disturbance. It is suggested that these lesions were attributable to focal macrophage clusters in the sub-retinal space with overlying dome-shaped elevations of the photoreceptor matrix. The severity of disease, as assessed clinically, correlated with the underlying histopathology but not with the serological titres against Toxoplasma. Immunocytochemical staining for Toxoplasma antigen revealed only intra-retinal Toxoplasma cysts, but no free organisms or extracystic antigen were demonstrated. Selective photoreceptor destruction was the most prominent histopathological feature, implicating auto-immune mechanisms of tissue destruction.

Acute Disease↗

Congenital toxoplasmic retinochoroiditis in the mouse--the use of the peroxidase anti-peroxidase method to demonstrate Toxoplasma antigen.

The peroxidase anti-peroxidase immunocytochemical staining method has been used to demonstrate Toxoplasma antigen within paraffin-embedded sections of the eyes of mice congenitally infected with Toxoplasma. Intact Toxoplasma tissue cysts were demonstrated within the retina but in no other ocular structure. No endozoites and no extra-cystic antigens were detected by this technique within any of the eyes examined. The possible implications of these findings in relation to the pathogenesis of toxoplasmic retinochoroiditis are discussed.

Animals↗