Objective: To investigate the effect of lead exposure before pregnancy on bone lead mobilization and bone microstructure in pregnant rats, so as to provide the evidence for illustrating the potential mechanisms of bone lead mobilization during pregnancy. Methods: Twenty-six weaning female specific pathogen-free (SPF) rats of the Wistar strain were randomly divided into the exposure group and the control group. Rats in the exposure group were given 0.05% lead acetate solution for weeks, while animals in the control group were given 0.05% sodium acetate solution. Then, rats in both groups were given distilled water. Following removal of lead exposure for 4 weeks, female rats were co-caged with healthy males at the same age until pregnancy. The blood, femur and tibia specimens were collected from female rats on days 3 (GD3), 10 (GD10) and 17 (GD17) at pregnancy, and the blood and bone lead levels were measured using inductively coupled plasma mass spectrometry (ICP-MS). The unilateral rat femur was scanned using micro-computed tomography (micro CT), and the microstructure changes of cortical and trabecular bones were investigated. The structural and morphological changes of rat femur were observed using hematoxylin-eosin (HE) staining. Results: During the study period, satisfactory mental status and activity and good coat glossiness were observed in female rats in both groups, and there was no significant difference in the increase of rat body weight between groups. The blood lead level at GD17 and bone lead levels at GD3, GD10 and GD17 were significantly higher in rats in the exposure group than in the control group (P<0.05), and the trabecular bone lead level was significantly lower in rats in the exposure group at GD17 than at GD10 (P=0.015). The trabecular bone lead level correlated negatively with blood lead level (r=-0.578, P=0.049), and bone lead contributed 26.8% to blood lead. The bone mass, trabecular number, thickness and density of female rat trabecular bones all reduced in the exposure group at GD17, with an increase in trabecular space, and the proportion of trabecular areas reduced by 27.34% in the exposure group relative to the control group (t=2.851, P=0.046). Conclusions Lead exposure before pregnancy promotes the release of lead from trabecular bones into blood and affects bone microstructure in rats. There is bone lead mobilization during late pregnancy.

Objective:To analyze the prevalence of parturiophobia and its association with preferred mode of delivery in pregnant women in Changning District, Shanghai.Methods:A cross- sectional study was conducted among 1 560 pregnant women in the third trimester who had their antenatal examination in Changning Maternity and Infant Health Hospital from September 2020 to March 2021. Fear of childbirth was measured with a validated Chinese version of Wijma Delivery Expectancy/Experience Questionnaire version A (W-DEQ-A). Based on the W-DEQ-A scores, the participants were divided into two groups: non-clinical parturiophobia group [<85 scores, including mild (≤37 scores), moderate (38-65 scores) and severe (66-84 scores) parturiophobia] and clinical parturiophobia group (≥85 scores). Rank-sum test, Chi-square test and t-test were used for univariate analysis. Multivariate binary logistic regression was used to analyze the factors associated with fear of childbirth and its relationship with preferred mode of delivery. Results:The detection rates of mild, moderate, severe and clinical parturiophobia were 18.8% (294/1 560), 44.9% (700/1 560), 31.1% (485/1 560) and 5.2% (81/1 560), respectively. Multivariate binary logistic regression showed that the participants who were supported by relatives and friends to have cesarean section ( OR=3.45, 95% CI: 1.29-9.22) or had antenatal anxiety ( OR=4.73, 95% CI: 2.49-8.97) were more likely to have clinical parturiophobia, while those with planned pregnancy ( OR=0.49, 95% CI: 0.29-0.82), high intensity physical activity ( OR=0.36, 95% CI: 0.18-0.72) or better/well understanding of the delivery process ( OR=0.42, 95% CI: 0.19-0.97) were less likely to develop clinical parturiophobia (all P<0.05). Compared with the non-clinical parturiophobia women, those with clinical parturiophobia were more likely to choose cesarean section ( OR=2.15, 95% CI: 1.22-3.78, P=0.008). Conclusions:The detection rates of severe and clinical parturiophobia are 31.1% and 5.2% in Changning District, Shanghai. The associated factors mainly include the attitudes of relatives and friends towards the mode of delivery, antenatal anxiety, planned pregnancy or not, physical activity level and the understanding of delivery process. Clinical parturiophobia might be an important factor for cesarean section on maternal request.

Objective In this study,Protosappanin A,Caesalpinia Sappan L extract and Cisplatin were combined with radiotherapy in gastric cancer cell SGC-7901 to investigate whether the Protosappanin A could in-crease radiosensitivity( SER) in gastric cancer SGC-7901 cells. This will be medication to create new areas of in-novation in the future. Methods The cell proliferation of SGC-7901 cells was detected by MTT assay. The rela-tionship between the effect of the Protosappanin A on cell proliferation and the time of action was determined. Caesalpinia Sappan L extract and Cisplatin were as controls. The fitted cell survival curve and clonal formation as-says were used to determine the SER to analyze the sensitizative effect of Protosappanin A. Results Protosappa-nin A could inhibit the growth of SGC-7901 cells,and its inhibitory effect is relatively weak. Its cytotoxicity has a time-and concentration-dependent manner. Cellular morphological changes were observed accompanying with increased concentrations and time treatments of Protosappanin A. Clonal formation experiment showed that the Protosappanin A significantly increased the radiosensitivity of SGC-7901 cells when compared to the radioactive group. They showed a statistically difference. Conclusion The inhibitory effect of the Protosappanin A on SGC-7901 cells in a concentration and time-dependent manner. Protosappanin A combined radiotherapy can improve the radiosensitization of cells,both of which may have synergistic anti-tumor effect.