Developmental Toxicity by Exposure to Bisphenol A Diglycidyl Ether during Gestation and Lactation Period in Sprague-dawley Male Rats / 예방의학회지

OBJECTIVES: Bisphenol A diglycidyl ether (BADGE) is the major component in commercial liquid epoxy resins, which are manufactured by co-reacting bisphenol A with epichlorohydrin. This study was performed to show the developmental effects of prenatal and postnatal exposures to BADGE in male rat offspring. METHODS: Mated female rats were divided into four groups, each containing 12 rats. The dosing solutions were prepared by thoroughly mixing BADGE in corn oil at the 0, 375, 1500 and 3000 mg/kg/day concentrations. Mated females were dosed once daily by oral gavage on gestation day (GD) 6 - 20 and postnatal day (PND) 0 - 21. Pregnant female dams were observed general symptoms and body weight. Also, male pups were observed the general symptoms, body weight, developmental parameters (e.g. anogenital distance, pina detachment, incisor eruption, nipple retention, eye opening, testis descent), organ pathologic changes and hormone levels of plasma. RESULTS: Pregnant rats treated with BADGE died at a rate of about 70% in the 1500 mg/kg/day group and all rats treated with 3000 mg/kg/day died. Body weight, for male pups treated with doses of 375 mg/kg/day, was significantly lower than in the control group at PND 42, 56, and 63 (p<0.05). Evaluation of body characteristics including; separation of auricle, eruption of incisor, separation of eyelid, nipple retention, descent of testis, and separation of the prepuce in the BADGE treated group showed no difference in comparisons with the control group. AGD and adjusted AGD (mm/kg) for general developmental items in BADGE 375 mg/kg/day treated pups tended to be longer than in controls, however, these differences were not statistically significant. Relative weights of adrenal gland, lung (p<0.05), brain, epididymis, prostate, and testis (p<0.01) were heavier than in control in measures at PND 9 weeks. There were no significant changes in comparisons of histological findings of these organs. Loss of spermatids was observed in the seminiferous tubule at PND 9 weeks, but no weight changes were observed. The plasma estrogen levels were similar in the control and treatment groups at PND 3, 6 and 9 weeks. The plasma testosterone levels in the control group tended to increase with age. However, in the BADGE 375 mg/kg/day treated male pups it did not tend to increase. CONCLUSIONS: These findings suggest that BADGE is a chemical that has developmental effects consistent with it being an endocrine disruptor.

Expression of MDM-2 and p53 Proteins in Gastric Adendegrees Carcinoma and Its Relationship with Clinicopathologic Factors / 대한암학회지

PURPOSE: MDM-2 is an oncoprotein that inhibits p53 tumor-suppressor protein. These abnor malities have a role in tumorigenesis through inactivation of p53 function. To determine the clini copathological and prognostic value of MDM2 abnormalities in gastric adendegrees Carcinoma, MDM-2& p53 protein expression were analysed in surgically resected materials of gastric adendegrees Carcinoma. MATERIALS AND METHODS: Fifty cases which had got follow-up after surgical resection were immunohistdegrees Chemically studied with p53 and MDM-2 antibodies. We defined variable clinico pathologic factors for expression of p53 and MDM-2 protein and analysed their relationships. RESULTS: Immunohistdegrees Chemical stain revealed expression of MDM-2 protein as a 52.0% (26/50) and p53 protein 20.0% (10/50), respectively. But their expressions were not assdegrees Ciated with clinicopathological factors such as T-factor, N-factor, stage, histology and differentiation. Overall, p53-negative patients seemed to have a better prognosis regardless of MDM-2 protein status (P= 0.057). MDM-2 protein status was considered to have no play as a prognostic factor. CONCLUSION: In the gastric adendegrees Carcinoma, p53 protein expression seemed to have a inverse relationship with clinical outcomes but MDM-2 protein expression, which was observed more frequently than those of p53, seemed not to be prognostic indicator.