Normal islet stained for insulin (right) and glucagon (left):
Islet under attack by immune system:
There are lots of other sites about islets on the web that you can find with a web browser. A couple of the higher quality ones I have found:
Islet with amyloid plaque (typical of type II diabetes)
A lecture on the endocrine pancreas and pancreatic hormones by Prof. D. A. Walsh of the University of California Davis.