Primary Intraosseous Squamous Cell Carcinoma Arising from Parakeratinized Kerato - Cystic Odontogenic Tumor Associated with Impacted Mandibular Canine: A Rare Entity.

Primary intraosseous carcinoma (PIOC) that arises from the epithelial lining of odontogenic cyst is a rare entity that represents about 1-2% of all oral and maxillofacial carcinoma. In particular, PIOC arising from keratocystic odontogenic tumor (KCOT) is rare when compared with such occurrence in other odontogenic cysts such as radicular cyst, residual cyst, and dentigerous cyst. Th e following case report discusses a case of squamous cell carcinoma arising from parakeratinized KCOT associated with impacted mandibular canine in a 43-year-old male patient with a complaint of painful swelling in the mandible. A review of reported cases from 1981 of PIOC arising from KCOT alone is also included.

A molecular weight study of adenosine deaminase.

Adenosine deaminase exists in its smallest molecular form (ADA-S) of < 42 kDa in primate and rodent brain, intestine and liver, human erythrocytes, avian liver and in bovine spleen and intestine. The enzyme exhibits molecular heterogeneity in monkey and chicken liver and human erythrocytes. The large form of adenosine deaminase is seen in monkey liver and intermediary forms of the enzyme in chicken liver and human erythrocytes. Large forms of the enzyme predominate in rabbit intestine. Molecular weights of adenosine deaminase molecular forms were determined by gel filtration and by non denaturing gel electrophoresis with construction of Ferguson plots. Anomalous migration of the enzyme on SDS-PAGE possibly due to charge, disulfide bonds and proline content, did not allow for molecular weight determination on denaturing gels.