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Quantifies total pancreatic beta-cell mass in diabetic patients in relation to obesity and treatment. Influence of insulin resistance and beta cell defect on type 2 diabetes; Evaluation of relative insulin content; Result of the abnormal coupling of insulin secretion to glycemia.

Paternal mutation of ATP-sensitive K(+) (K(ATP)) channel genes and loss of heterozygosity (LOH) of the 11p15 region including the maternal alleles of ABCC8, IGF2, and CDKN1C characterize the focal form of persistent hyperinsulinemic hypoglycemia of infancy (FoPHHI). We aimed to understand the actual nature of FoPHHI in comparison with insulinoma. In FoPHHI, the lesion consists in clusters of beta-cells surrounded by non-beta-cells. Compared with adjacent islets, proinsulin mRNA is similar and proinsulin production higher (P < or = 0.02), indicating regulation at a translational level, with slightly lower insulin stock and lower ABCC8 peptide labeling (P<0.05). Insulinomas, composed of beta-cell nests or cords, have similar proinsulin mRNA compared with adjacent islets, highly variable proinsulin production, lower insulin stock (P < or = 0.02), and higher ABCC8 peptide labeling (P<0.05). Proinsulin mRNA is lower than in FoPHHI (P<0.001). Islets adjacent to FoPHHI appear to be resting, in contrast to those adjacent to insulinomas, evidencing intrapancreatic regulation of islet beta-cell activity. IGF2 peptide is present inside and outside both lesions, but IGF2 mRNA is restricted to the lesions. The 11p15 LOH and absence of CDKN1C peptide staining are demonstrated in all FoPHHI but also in three of eight insulinomas. Despite some molecular similarities, FoPHHI is thus fundamentally different from insulinoma. [ABSTRACT FROM AUTHOR]

Paternal mutation of ATP-sensitive K[sup +] (K[sub ATP]) channel genes and loss of heterozygosity (LOH) of the 11p15 region including the maternal alleles of ABCC8, IGF2, and CDKNIC characterize the focal form of persistent hyperinsulinemic hypoglycemia of infancy (FoPHHI). We aimed to understand the actual nature of FoPHHI in comparison with insulinoma. In FoPHHI, the lesion consists in clusters of β-cells surrounded by non-βcells. Compared with adjacent islets, proinsulin mRNA is similar and proinsulin production higher (P ≤ 0.02), indicating regulation at a translational level, with slightly lower insulin stock and lower ABCC8 peptide labeling (P<0.05). Insulinomas, composed of β-cell nests or cords, have similar proinsulin mRNA compared with adjacent islets, highly variable proinsulin production, lower insulin stock (P ≤ 0.02), and higher ABCC8 peptide labeling (P<0.05). Proinsulin mRNA is lower than in FoPHHI (P<0.001). Islets adjacent to FoPHHI appear to be resting, in contrast to those adjacent to insulinomas, evidencing intrapancreatic regulation of islet β-cell activity. IGF2 peptide is present inside and outside both lesions, but IGF2 mRNA is restricted to the lesions. The 11p15 LOH and absence of-CDKN1C peptide staining are demonstrated in all FoPHHI but also in three of eight insulinomas. Despite some molecular similarities, FoPHHI is thus fundamentally different from insulinoma. [ABSTRACT FROM AUTHOR]

Examines the morphological evidence for abnormal beta-cell function in human type 2 diabetes. Observation of amyloid deposits in island of Langerhans cells; Effect of insular amyloid deposits on beta-cell transcription and translation.