Minoru Ueyama

Progressive deterioration of insulin secretion in Japanese type 2 diabetic patients in comparison with those who carry the S20G mutation of the islet amyloid polypeptide gene: A long-term follow-up study.

Aims/Introduction:  In order to clarify the enhanced β‐cell dysfunction in type 2 diabetic patients carrying the S20G mutation of the islet amyloid polypeptide gene (S20G‐patients), we first estimated the decline of insulin secretion in Japanese type 2 diabetic patients without the S20G mutation (non‐S20G‐T2D‐patients) by long‐term observation, and then compared it with that of the S20G‐patients.

Protective role of human insulin against the cytotoxicity associated with human mutant S20G islet amyloid polypeptide

Islet amyloid polypeptide (IAPP) is a main component of islet amyloid in type 2 diabetes and cosecreted from β‐cell with insulin. Clinical evidence from the patients with S20G mutation of the IAPP gene, as well as experimental evidence that insulin could inhibit amyloid formation of IAPP, suggests that a gradual reduction of insulin could be related to the cytotoxicity associated with S20G‐IAPP through long‐term deterioration of β‐cells in type 2 diabetes. Our objective was to show an effect of human insulin on S20G‐IAPP associated cytotoxicity.

Combined examination of glyceryl trinitrate-mediated vascular dilation with flow-mediated vascular dilation is essential for assessment of vascular function in type 2 diabetes

In order to characterize the impaired vascular function in type 2 diabetes (DM) patients, we evaluated the flow‐mediated vascular dilation (FMD) with glyceryl trinitrate‐mediated vascular dilation (NMD) using ultrasonography.