Structure of the human glucokinase gene and identification of a missense mutation in a Japanese patient with early-onset non-insulin-dependent diabetes mellitus

Glucokinase is thought to play a glucose-sensor role in the pancreas, and abnormalities in its structure, function, and regulation can induce diabetes. We isolated the human glucokinase gene, and determined its genomic structure including exon-intron boundaries. Structure of the glucokinase gene in human was very similar to that in rat. Then, by screening Japanese diabetic patients using polymerase chain reaction--single strand conformation polymorphism (PCR-SSCP) and direct-sequencing strategies, we identified a missense mutation substituting arginine (AGG) for glycine (GGG) at position 261 in exon 7 of the glucokinase gene in a patient with early-onset non-insulin-dependent diabetes (NIDDM).

[A case of invasive thymoma which had grown in the SVC via left innominate vein through thymic vein]

A 66-year-old male was referred to our department with mediastinal tumor. The chest X-ray and the chest CT showed a large tumor adjacent to pulmonary artery and descending aorta. Cavogram revealed a filling defect of the SVC. He underwent complete resection of the tumor, resection of the SVC and reconstruction of the SVC with ringed PTFE. The main tumor was 12 x 7 cm in size and the tumor in the SVC was 20 x 15 mm in size. Histopathological findings showed a lymphocytic thymoma. Compact invaded nest of tumor cell was found in the innominate vein. The tumor in the SVC was invasive to the intima of the SVC, but its media and adventure were intact. This case is rare among patients with invasive thymoma as far as the growth is concerned.