Search

Osteoclasts from growth plates of affected (mi/mi) and control (mi/+) microphthalmic mice, from newborn to 15 days old, were examined. Osteoclasts from unaffected mice were generally large, multinucleated cells with distinct ruffled borders and clear zones. Osteoclasts from the mi/mi litter mates were predominantly mononucleated, lacking in ruffled borders, clear zones and an abundance of organelles, features not normally associated with a functioning resorptive cell. The lamina limitans was more distinct in mi/mi mice. By 15 days, no evidence of bone resorption was seen in mi/mi mice. The immature appearance of osteoclasts and the lack of bone marrow cavity formation in mi/mi mice may result from either a fusion defect or from a limited life span of osteoclasts.

An Australian family in which two members were affected by focal palmoplantar and gingival mucosal hyperkeratosis syndrome is reported. The propositus and his daughter had symptoms which suggested that esophageal lesions might be present. In view of the association of tylosis with esophageal carcinoma in other families, both patients were investigated by barium swallow or endoscopy. No esophageal lesions were found. Previously unreported paranuclear bodies were described in the keratinocytes of the spinous and granular cell layers of the finely papillated gingival epithelium of the propositus. Similar paranuclear bodies, although rare, were identified in cytologic smears from the four members of the family examined, two of whom had slight whitening of the mucosa of the retromolar pads only. By electron microscopy and histochemistry, these bodies were characterized as condensations of tonofilaments and not heteromorphic keratohyalin.