Streptozotocin (STZ) is an antibiotic that can cause pancreatic β-cell destruction, so it is widely used experimentally as an agent capable of inducing insulin-dependent diabetes mellitus (IDDM), also known as type 1 diabetes mellitus (T1DM). This unit describes protocols for the production of insulin deficiency and hyperglycemia in mice and rats, using STZ. These models for diabetes can be employed for assessing the mechanisms of T1DM, screening potential therapies for the treatment of this condition, and evaluation of therapeutic options.

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Recent evidence has showed that nephrogenic adenoma is a true "nephrogenic" lesion derived from the proliferation of exfoliated and implanted renal tubular cells in the urinary tract, a process that closely resembles the formation of endometriosis. This new concept has led to the identification of renal transcription factor PAX2 as a diagnostic marker for nephrogenic adenoma. PAX8 is another transcription factor structurally and functionally related to PAX2. Both are cell lineage restricted transcription factors expressed in normal and neoplastic tissues of related origin, including renal tubular cells in both fetal and adult kidneys. In this study, we investigated the expression of PAX8 in nephrogenic adenoma and its mimics. We report here that PAX8 was detected in all nephrogenic adenomas (N=35) and clear cell adenocarcinoma of the lower urinary tract (N=7), but not in prostate adenocarcinoma (N=100), adenocarcinoma (N=9), squamous cell carcinoma (N=5), or urothelial carcinoma (N=48) of the urinary bladder and its variants. PAX8 was neither detected in normal urothelium of the urinary bladder nor in prostate glands and stroma. PAX2 was also detected in 2 of the 7 clear cell adenocarcinomas of the lower urinary tract. We suggest that PAX8 is an additional marker for identifying nephrogenic adenoma. Expression of PAX8 or PAX2 in both nephrogenic adenoma and clear cell adenocarcinoma of the lower urinary tract may indicate a possible related tissue origin for these 2 lesions; both may be derived from proliferating renal tubular cells in the urinary tract. In addition, detection of PAX8 or PAX2 in clear cell adenocarcinoma of the lower urinary tract is helpful in differentiating it from urothelial carcinoma and its variants and adenocarcinomas of the urinary bladder or of the prostate.

We report the first characterization of PNL-2 staining in head and neck mucosal melanoma. PNL-2 demonstrates high sensitivity for mucosal melanoma, likely superior to Melan-A and MITF, and comparable to HMB-45, with specificity superior to S-100. We advocate inclusion of PNL2 as an important adjunctive marker in the evaluation of these lesions.

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