The effect of botulinum toxin on ureteral inflammation.

PURPOSE: The impact of onabotulinum toxin type A (BoNT-A) on bladder afferent nerve pathways and chemosensory functions is an active area of investigation. There may be a role for BoNT-A in disorders of the ureter; however, no histologic studies have assessed the effects of BoNT-A on ureteral tissue. Our objective was to develop an animal model of ureteral inflammation and determine the impact of ureteral BoNT-A instillation on known mechanisms of inflammation. METHODS: The safety and feasibility of a novel animal model of ureteral inflammation was assessed. Through open cystotomy, the effect of ureteral BoNT-A instillation on inflammation was determined through H&E, masson's trichrome, Ki-67 stain, and prostaglandin E (PGE) synthase expression, a known marker of pain and inflammation in ureteral tissue. Urothelial microstructure was assessed using electron microscopy and standard histologic techniques. RESULTS: All experiments were carried to completion, and no systemic signs of botulinum toxicity were seen. BoNT-A exposure was associated with a decrease in PGE synthase expression in a dose-dependent fashion. BoNT-A exposure was not found to impact collagen deposition or cell proliferation. Disruption of tight junctions between urothelial cells was observed under conditions of inflammation. CONCLUSION: We describe the feasibility of a novel in vivo model of ureteral inflammation and report the first histologic study of the effects of BoNT-A on the ureter. Preliminary findings show that BoNT-A attenuates ureteral PGE synthase expression under conditions of inflammation. The application of BoNT-A may provide anti-inflammatory and analgesic effects in the context of ureteral disorders.

Does pTis exist in HPV-driven tonsillar carcinomas? An ultrastructural review and examination of two cases.

Many tonsillar tumors present clinically as cervical nodal metastases and the primary tumor is often difficult to find. HPV-driven tonsillar carcinoma begins in the reticulated crypt epithelium, possibly through viral integration. The basement membrane is not complete in the reticulated crypt epithelium, which may enhance the immune function. We examined the reticulated crypt epithelium in a normal case and five neoplastic tonsils with cervical metastasis as the presenting symptom to further investigate whether tonsil carcinoma in-situ exists. Our results suggest that in-situ carcinoma may need to be excluded from the future staging for human papilloma virus associated tonsillar tumors.