Life history of experimentally induced acute oral candidiasis in the rat

A simple method of oral inoculation with Candida albicans was used to study the course of candidiasis in the rat. Changes in the pattern of keratinization of the epithelium were prevalent with minimal involvement of the underlying corium at the site of infection.

The surface layer of human foetal skin and oral mucosa: a study by scanning and transmission electron microscopy

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Studies on the origin of mononuclear cells in delayed hypersensitivity reaction of oral mucosa

Delayed hypersensitivity reactions in guinea pig mucosa were studied by use of tritiated thymidine. No selective accumulation of labeled cells from regional nodes was found in the reaction sites, and no difference was found between test and control animals in the activity of the regional nodes. Cell proliferation in the mucosal reaction began early and the proportion of cells dividing increased with time.

The retest contact hypersensitivity reaction in guinea pig skin and oral mucosa

A chemical sensitiser, 2:4 di-nitro-chloro-benzene was reapplied to previously elicited delayed hypersensitivity sites in guinea pig skin and oral mucosa and the macroscopic and microscopic appearances of these “restest” sites compared with adjacent delayed hypersensitivity reactions to the chemical produced at the same time.

In the sites where the chemical sensitiser had been reapplied, oedema was evident, macroscopically, at an earlier stage than in the delayed hypersensitivity sites. Microscopically, vascular dilatation and the presence of a mononuclear infiltrate were apparent in the “retest” sites earlier than in the delayed hypersensitivity sites. There was an initial reduction in the count of eosinophil polymorphonuclear leucocytes in the “retest” and delayed reaction in skin and oral mucosa. A late rise in the count of these cells occurred in the “retest” reactions in skin and oral mucosa, but was more pronounced in the mucosa. There was no significant alteration in the mast cell count in the “retest” or delayed hypersensitivity reactions in the skin or oral mucosa. It is suggested that the mononuclear infiltrate remaining after the delayed hypersensitivity reaction is associated with the more rapid vascular changes which accompany the “retest” reaction.

Transfer of an escape response from tail shock to brain-stimulated attack behavior

Nine cats, each with two hypothalamic electrodes in sites which when stimulated produced either quiet attack or attack accompanied by certain forms of vocalization, were trained to escape from tail shock by jumping onto a stool. They were then tested for transfer of the escape response to brain stimulation. Stimulation of the seven sites that yielded quiet biting attack did not elicit the learned response of jumping onto the stool. Stimulation of eight of the 11 sites that yielded attack accompanied by vocalization did elicit the learned response. It was concluded that attack behavior elicited by brain stimulation should not be considered a special case of the response to aversive stimulation, but that attack and response to aversive stimulation involve independent but overlapping systems.