The underlying effect of different concentrations of neogenin on proliferation, apoptosis and the related proliferative factors in human trophoblasts was explored in order to understand the function of neogenin during placentation. TEV-1 cell line was cultured and the expression of netrin-1 was detected by using indirect cellular immunofluorescence. Exponentially growing TEV-1 cells were treated by different concentrations of neogenin (0, 1, 5, 10, 50 ng/mL) for 24 h. Cell viability was measured by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. TEV-1 cell apoptosis was assessed by flow cytometry (FCM). The expression of netrin-1 mRNA and protein in TEV-1 cells was examined by using real-time PCR and Western blot, respectively. It was found that immunoreactivity for netrin-1 was observed in cytoplasm of the trophoblasts. Immediately after treatment with different concentrations of neogenin for 24 h, the netrin-1 expression began to increase. Real-time PCR revealed that the expression level of netrin-1 mRNA was 37.59±10.25 times higher than control group when TEV-1 cells were exposed to 50 ng/mL neogenin (P<0.01), and the same tendency was seen by using Western blot. MTT results showed that proliferation of TEV-1 cells was independent of neogenin. Meanwhile, apoptosis was significantly increased to (22.15±6.15)% at 50 ng/mL neogenin and (6.55±0.25)% without neogenin (P<0.01). It is suggested that neogenin regulates proliferation and apoptosis of TEV-1 cells. And it can enhance the ability of TEV-1 cells to express netrin-1 in a dose-dependent manner. Neogenin may play an important biological role in the normal human pregnancy and contribute to the physiological pregnancy process.
This study evaluated the efficacy and safety of ＂J＂-shaped uterine incision for caesarean section for patients diagnosed with placenta previa. A total of 55 consecutive cases of placenta previa treated in Union Hospital were retrospectively analyzed over a period of two years and 10 months. The subjects were divided into two groups with respect to the uterine incision. Twenty-four pregnant women with placenta previa who were indicated for caesarean section underwent the procedure using a new ＂J＂-shaped uterine incision and 31 pregnant women with placenta previa received caesarean section that used the traditional transverse incision. The two groups were compared in terms of operation time, estimated blood loss, infant expulsion time, exhaust time and postoperative recovery. Meanwhile, comparison was also made in neonatal clinical data between the two groups. Compared with the ＂J＂-shaped incision group, the traditional incision group had a lower Apgar scores （P〈0.05）. However, there existed no statistically significant differences in the overall time of operation and postoperative period of breaking wind （P〉0.05）. It is concluded that, with caesarean section for placenta previa patients, the ＂J＂-shaped uterine incision significantly decreases intraoperative blood loss and facilitates the fetal delivery.
