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Purpose: To develop methods to delineate the relationship between endothelial cell toxicity and tissue fixation (toxicity/fixation) using sodium hydroxymethylglycinate (SMG), a formaldehyde releaser, and riboflavin-UVA photochemical corneal cross-linking (CXL) for therapeutic tissue cross-linking of the cornea., Methods: Eleven fresh cadaveric rabbit heads were used for ex vivo corneal cross-linking simulation. After epithelial debridement, the tissue was exposed to 1/4 max (9.8 mM) or 1/3 max (13 mM) SMG at pH 8.5 for 30 minutes or riboflavin-UVA (CXL). The contralateral cornea served as a paired control. Postexposure, cross-linking efficacy was determined by thermal denaturation temperature (Tm) and endothelial damage was assessed using calcein AM and ethidium homodimer staining (The Live/Dead Kit). Confocal laser scanning fluorescence microscopy was used to generate live/dead cell counts using a standardized algorithm., Results: The ΔTm after CXL, 1/3 SMG, and 1/4 SMG was 2.2 ± 0.9°C, 1.3 ± 0.5°C, and 1.1 ± 0.5°C, respectively. Endothelial cell damage was expressed as the percent of dead cells/live + dead cells counted per high-power field. The values were 3 ± 1.7% (control) and 8.9 ± 11.1% (CXL) (P = 0.390); 1 ± 0.2% (control) and 19.5 ± 32.2% (1/3 max SMG) (P = 0.426); and 2.7 ± 2.4% (control) and 2.8 ± 2.2% (1/4 max SMG) (P = 0.938). The values for endothelial toxicity were then indexed over the shift in Tm to yield a toxicity/fixation index. The values were as follows: 2.7 for CXL, 14 for 1/3 max, and 0.1 for 1/4 max., Conclusions: Quarter max (1/4 max = 9.8 mM) SMG effectively cross-linked tissue and was nontoxic to endothelial cells. Thus, SMG is potentially a compound that could achieve both desired effects.

Background: Lipid-cell tumors are rare, functioning ovarian neoplasms. They have not been reported in women with von Hippel-Lindau syndrome, an autosomal-dominant tumor-suppressor gene mutation that is associated with renal cell carcinoma, and other vascular tumors., Cases: Two women with von Hippel-Lindau syndrome and kidney tumors were evaluated for secondary amenorrhea, hirsutism, and complex adnexal masses seen on computed tomography. The first patient had known renal cancer and bilateral adnexal masses, one with central necrosis. Because metastatic renal cell cancer could not be excluded on frozen section, bilateral salpingo-oophorectomy was performed. The second patient underwent right salpingo-oophorectomy after human chorionic gonadotropin testing confirmed that the ovarian tumor produced testosterone. Final pathology in both cases revealed testosterone-secreting lipid cell tumors., Conclusion: Lipid cell ovarian tumors should be considered in women with von Hippel-Lindau presenting with adnexal mass, amenorrhea, and hirsuitism.