No abstract

OBJECTIVES: The aim of this study was to identify the principle clinical features of the peripheral giant cell granuloma (PGCG), and to recognise clinical features of PGCG that are poorly defined. DESIGN: We reviewed retrospectivety 77 cases of PGCG from 62 patients, from our files with respect to incidence, sex, patient age, race, clinical symptoms and signs, radio‐graphic features and recurrence following excision. RESULTS AND CONCLUSIONS: Our results were largety in agreement with previous reports, although there is wide variation in the results published between series. In addition, some clinical features of PGCG are poorly defined. Little is known about the retative incidences of PGCG and central giant cell granuloma. An association between PGCG and tooth loss may exist, but is poorly defined, and not all PGCG that involve edentulous areas follow recent tooth loss. Information about PGCG recurrence after excision is limited, and does not necessarily follow incomplete excision. Despite the large number of reported cases of PGCG, clarification of some clinical features is required, and may hetp formulation and interpretation of future laboratory‐based research into this poorly understood lesion.

Variation in the percentage of labelled cells (LI), mitoses (MI) and apoptosis (AI: i.e. shrinkage necrosis) have been studied throughout a 24 hr period (40 min after labelling with 3H‐TdR) for tongue epithelium, epidermis and intestinal epithelium in the mouse. A room with reversed light cycle was used to obtain data for half of the 24 hr period. All three tissues showed marked variations in LI with peak values between 24.00 and 03.00 hours. In the intestine a maximum value for MI was observed 3‐6 hr after that for LI and with a maximum value for AI slightly later. In all three epithelia the circadian rhythm was most striking in cells at positions which can be correlated with presumptive stem cell activity; e.g. in the crypts the labelling and mitotic peaks reflecting a circadian rhythm were most clearly distinguishable at the basal part of the crypts. These observations are discussed in relation to the validity of various proliferative models.