The Effects of Calcium-Phosphate Coated Xenogenic Bone and Type I Collagen for Bone Regeneration on the Calvarial Defects in Rabbits / 대한치주과학회지

No abstract available.

Effect of Hypoxia on Telomerase Activity in Placental Tissue in Pregnancies with Fetal Growth Restriction / 대한산부인과학회잡지

OBJECTIVE: To observe the difference in telomerase activity (TA) expression in the placenta between fetal growth restriction (FGR) with preeclampsia and those without and to evaluate the effect of oxygen concentration on the TA expression in the trophoblastic cells. METHODS: Telomerase activity was measured in 48 (normal pregnancies, 16; preeclampsia with FGR, 15; normotensive FGR, 17) placentas which were obtained between 32 and 41 weeks' gestations. Trophoblastic cells were extracted from 8 chorionic villi samples obtained from 8-10 weeks' placenta and were cultured in either 2%, 8%, and 20% oxygen atmosphere. Then TA was examined by using telomeric repeat amplification protocol (TRAP) assay. RESULTS: During 3rd trimester of pregnancy, exhibited TA expression in normal pregnancy, FGR complicated by preeclampsia, and normotensive FGR groups were 11 of 16 (68.8%), 4 of 15 (26.7%), and 4 of 17 (23.5%), respectively. Significantly lower level of TA was detected in the FGR group compared to the normal pregnancies (p=0.009), whereas within FGR pregnancies, presence of preeclampsia did not seem to have statistically significant effect on TA expression. TA expression levels were measured by optical density in trophoblasts cultured under various oxygen concentration which revealed that significantly higher TA was exhibited in the cells cultured in 2% oxygen compared to 8% and 20% (p<0.001). However no significant difference was noted in TA between cells cultured in 8% and 20% oxygen. CONCLUSION: Decreased TA in the placenta from pregnancies with FGR was noted regardless of presence of preeclampsia indicating a probable correlation between FGR and placental senescence. Since increased TA was noted in trophoblastic cells that were cultured in hypoxic condition, we could speculate that the intervillous oxygen tension during early-stage placental development plays a certain role in the placental degeneration in pregnancies complicated by FGR and preeclampsia.

Telomerase Activity In Human Placenta Tissues: Comparison Between Preeclampsia With and Without Fetal Growth Restriction / 대한산부인과학회잡지

OBJECTIVES: To analyze telomerase activity(TA) in human placenta tissues and to compare TA in preeclampsia with or without fetal growth restriction(FGR) METHODS: Fourty-six placenta specimens were obtained from pregnant women between 29 and 41 weeks' gestation. TA of each specimen was analyzed including 21 specimens without either preeclampsia or FGR(Group 1), 9 specimens with preeclampsia but without FGR(Group 2), and 16 specimens with both preeclampsia and FGR(Group 3). TA was analysed by radioisotope PCR based telomeric repeat amplification protocol(TRAP) assay. TA was calculated and translated into arbitrary units by computer-assisted densitometry with the control of TA in 293 cell lines. RESULTS: TA was expressed in 16 of 21(76.1%) in group 1, and in 3 of 9(33.3%) in group 2. In contrast, only 4 patients(25%) in group 3 expressed TA. Thus, TA was expressed significantly more often in group 1 than in group 2 and group 3(p=0.003). However, compared with group 2, expression of telomerase activity in group 3 was not reduced significantly(p>0.05). CONCLUSION: TA was minimal in placenta from preeclamptic women with and without FGR, suggesting placental senescence and apoptosis may be associated with FGR and severe preeclampsia.

Comparison of Telomerase Activity in Human Chorionic Villi between Eutopic and Ectopic Pregnancies / 대한산부인과학회잡지

No abstract available.