Figure 4.

Confocal microscopy images of pancreas from 3 patients double immunolabeled for proinsulin (green) and PDX1 (red) and nuclear stained with To-Pro 3 (blue). a) Atypical islet structures from case #1 showing proinsulin-containing cell which does not exhibit nuclear PDX1 labeling (arrowhead) and several cells which are negative for proinsulin but show nuclear PDX1 labeling (arrows). b) Atypical islet structures from case #2 showing a mixture of typical β-cells with both proinsulin and nuclear PDX1 labeling (arrowheads) and atypical cells showing only proinsulin labeling (arrows). c) Atypical islet structures from case #3 showing cells with proinsulin labeling which lack nuclear PDX1 labeling (arrows) and some cells with nuclear PDX1 which lack proinsulin labeling (arrowhead). d) Normal islets from case #3 showing double labeling of β-cells for proinsulin and PDX1.