Fig. 3.

Morphological, paracrinological, and clinical features of pancreatic islets in T1DM. (A) Confocal microscopy of islet from a patient with T1DM shows replacement of insulin-containing cells with glucagon-containing cells (green) devoid of contact with β-cells. (Photomicrograph provided by L.O.) (B) In the absence of juxtaposed insulin-secreting cells, basal glucagon levels are increased and they increase further in a paradoxical response to hyperglycemia from a carbohydrate-containing meal, thereby worsening the basal hyperglycemia. (C) Even the subjects with optimally controlled T1DM exhibited severe glycemic volatility in a study by Derr et al. (31).