The effect of bisphenol A on cell apoptosis pattern in the spinal cord of chick embryos / 대한주산의학회잡지

OBJECTIVE: To investigate the effects of bisphenol A (BPA) on cell death pattern in neuronal development of chick embryos. MATERIALS AND METHODS: We planned to compare the cytokinetic features in the normal chick embryo and those with BPA. Fifteen eggs were divided into three GROUPS: the control group, BPA 50 microgram/g egg group and BPA 200 microgram/g egg group. Embryos were incubated for 56 hours (Hamburger & Hamilton stage 16) and then we injected BPA into embryos. The embryos were sectioned by 3 micrometer thickness at the level of wing buds and stained at 72 hours after incubation (HH stage 18). We observed cell death in the spinal cord using terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) method. RESULTS: The TUNEL-positivity markedly increased in proportion to the doses of BPA. The number of TUNEL-positive cells per section was 15.2+/-2.14 in the control group, 34.6+/-3.44 in the BPA 50 microgram/g egg group, 87.6+/-4.32 in the BPA 200 g/g egg group. Furthermore the contour of spinal cord was deformed as the doses of BPA raised. CONCLUSION: BPA causes neuronal cell death and exerts cytotoxic effect on early chick embryos. It suggests that BPA might have an effect on cytogenesis during neural tube development.

Expression of claudin-1, claudin-4 and zonula occludens-1 in cervical intraepithelial neoplasia and invasive squamous cell carcinoma / 대한산부인과학회지

OBJECTIVE: Cell to cell and cell to extracellular matrix interaction are crucial in tumor development and progression. Tight junction proteins such as claudins and zonula occludens-1 (ZO-1) play an important role in these processes. This study was performed to investigate the difference of expressions of claudin-1, claudin-4 and ZO-1 in low grade squamous intraepithelial lesion (LSIL), high grade squamous intraepithelial lesion (HSIL), and invasive squamous cell carcinoma (ISCC) of the uterine cervix. METHODS: The expressions of claudin-1, claudin-4 and ZO-1 were evaluated using immunohistochemical staining in 78 cervical tissue specimens (LSIL 22 case, HSIL 36 case, and ISCC 20 case). RESULTS: Claudin-1 expression was positive in 40.9% of LSIL, in 94.0% of HSIL and in 20.0% of ISCC. The expression of claudin-1 was significantly high in HSIL (p=0.0001). Claudin-4 expression was positive in 31.8% of LSIL, in 41.7% of HSIL and in 25.0% of ISCC. The expression of claudin-4 was high in HSIL, but it was not statistically different. ZO-1 expression was positive in 13.6% of LSIL, in 41.7% of HSIL, and in 25.5% of ISCC. The expression of ZO-1 was significantly high in HSIL (p=0.011). CONCLUSION: These results indicate increased expressions of claudin-1 and ZO-1 in the HSIL that includes cervical intraepithelial neoplasia (CIN) 2 and 3, which decrease during progression to cervical cancer.