PURPOSE: To assess the role of nitric oxide in the development of cataract by detection of nitrotyrosine, which is a reaction product of peroxynitrite with tyrosine. METHODS: We have collected aqueous humor and anterior capsule of lens after cataract surgery from 14 eyes. We classified lens opacities into three types such as nuclear sclerosis, cortical and posterior subcapsular opacity. Nitrite, stable oxidative product of nitric oxide, was measured in the aqueous humor and immunohistochemical staining for nitrotyrosine was performed to examine anterior capsules. RESULTS: The concentrations of nitric oxide in aqueous humor were 0.0698+/-0.0036, 0.0652+/-0.0116, and 0.0700+/-0.0022 mM in nuclear sclerosis, cortical and posterior subcapsular opacity, respectively and no significant differences existed among lens opacity types. In lenses with cortical and posterior subcapsular opacity, the expression of nitrotyrosine was observed around epithelial cell and intercellular space. There was no expression of nitrotyrosine in lenses with nuclear sclerosis. CONCLUSIONS: This results suggest that nitration of tyrosine by peroxynitrite is possibly related to the cataractogenesis of lenses with cortical and posterior subcapsular opacity.
Aqueous Humor ; Capsules ; Cataract* ; Epithelial Cells ; Extracellular Space ; Nitric Oxide* ; Peroxynitrous Acid ; Sclerosis ; Tyrosine

Nucleolar organizer regions(NORs) contain coding genes for ribosomal RNA and contribute the regulation of cellular protein synthesis. AgNORs numbers correlate with growth fraction and have been reported the AgNORs counts may have a diagnostic and prognostic utility in other human tumors. We investigated the diagnostic usefulness of AgNORs staining technique as a discriminant for malignancy and assessed the value as a potential method for the estimation of cell kinetics. In addition. we compared the AgNOR counts with flow cytometric analysis of ploidy, S-phase fraction, proliferation index, and PCNA expression rate. There was a statistically significant difference of AgNORs counts between superficial bladder tumor and invasive bladder tumor. But there was no relationship between the mean number of AgNORs per nucleus and histological grade. DNA aneuploid group was associated with higher AgNORs counts than diploid group, but the difference was statistically insignificant. The mean number of AgNORs per nucleus had significant relationship to SPF(r=0.43, p<0.05) and PI(r=0.41, p<0.05.) We concluded that this method alone does not offer a reliable histological discriminant for malignancy. Further studies are needed to confirm that AgNORs counting is a useful method for evaluating the proliferative activity and this technique may serve as a prognostic factor additional to the current histopathological grading criteria of the bladder cancer.
Aneuploidy ; Carcinoma, Transitional Cell* ; Clinical Coding ; Diploidy ; DNA ; Humans ; Kinetics ; Nucleolus Organizer Region* ; Ploidies ; Proliferating Cell Nuclear Antigen* ; RNA, Ribosomal ; Silver* ; Urinary Bladder Neoplasms ; Urinary Bladder*