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Pinto A.,University of Miami | McLaren S.H.,Cornell University | Poppas D.P.,Institute for Pediatric Urology | Magro C.M.,Cornell University
American Journal of Dermatopathology | Year: 2012

Genital melanocytic nevus represents a distinct form of melanocytic proliferation, which can exhibit significant atypia, both clinically and histologically. In a background of lichen sclerosus (LS), the histologic changes could be misconstrued as indicative of malignant melanoma. We present herein a case of the atypical genital nevus of childhood complicated by LS, and a review of the literature is performed. Tissue was available for routine light microscopy and immunohistochemical evaluation to assess the expression of soluble adenylyl cyclase. Fluorescent in situ hybridization studies were conducted to assess for abnormalities in Myb1, CCND1, RREB1 and CEP6. The specimen showed an atypical compound melanocytic proliferation arising in a background of LS. The lesion exhibited significant architectural atypia based on the high-density confluent nature of the junctional melanocytic proliferation with epidermal effacement, rare areas of pagetoid ascent, and the heavily pigmented epithelioid quality of the melanocytes. Fluorescent in situ hybridization studies were normal. The soluble adenylyl cyclase antibody preparation demonstrated a benign nevus-like pattern. The lesion was felt to represent an atypical genital melanocytic nevus, which can resemble a partially regressed melanoma in a background of LS. It is very important for the pathologist to be aware of this entity to avoid misdiagnosis. Copyright © 2012 by Lippincott Williams & Wilkins. Source

Carlsen I.,University of Aarhus | Carlsen I.,Aarhus University Hospital | Donohue K.E.,Institute for Pediatric Urology | Jensen A.M.,University of Aarhus | And 9 more authors.
American Journal of Physiology - Regulatory Integrative and Comparative Physiology | Year: 2010

Renal medullary interstitial cells (RMICs) are subjected to osmotic, inflammatory, and mechanical stress as a result of ureteral obstruction, which may influence the expression and activity of cyclooxygenase type 2 (COX-2). Inflammatory stress strongly induces COX-2 in RMICs. To explore the direct effect of mechanical stress on the expression and activity of COX-2, cultured RMICs were subjected to varying amounts of pressure over time using a novel pressure apparatus. COX-2 mRNA and protein were induced following 60 mmHg pressure for 4 and 6 h, respectively. COX-1 mRNA and protein levels were unchanged. PGE2 production in the RMICs was increased when cells were subjected to 60 mmHg pressure for 6 h and was prevented by a selective COX-2 inhibitor. Pharmacological inhibition indicating that pressure-induced COX-2 expression is dependent on p38 MAPK and biochemical knockdown experiments showed that NF-κB might be involved in the COX-2 induction by pressure. Importantly, terminal deoxyneucleotidyl transferase-mediated dUTP nick-end labeling and methylthiazoletetetrazolium assay studies showed that subjecting RMICs to 60 mmHg pressure for 6 h does not affect cell viability, apoptosis, and proliferation. To further examine the regulation of COX-2 in vivo, rats were subjected to unilateral ureteral obstruction (UUO) for 6 and 12 h. COX-2 mRNA and protein level was increased in inner medulla in response to 6- and 12-h UUO. COX-1 mRNA and protein levels were unchanged. These findings suggest that in vitro application of pressure recapitulates the effects on RMICs found after in vivo UUO. This directly implicates pressure as an important regulator of renal COX-2 expression. Copyright © 2010 the American Physiological Society. Source

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