ObjectiveTo explore the bone anabolic effects after a single local injection of simvastatin into femoral cavities of osteoporotic rats.MethodsThirty-six female SD rats(3 months old,body weight 250-300 g) were ovariectomized(OVX) and low-calcium-diet fed for 3 months,OVX rats were randomized into 3 groups(n=12).Left femurs of group A,B and C were injected with 0,5 and 10 mg simvastatin,respectively.Half of the rats in each group were randomly euthanized separately 1 and 5 months after simvastatin injection.Left femurs were taken out for bone mineral density (BMD) assessment with dual energy X-ray absorptiometry,bone histomorphometic changes were analysized by Micro-CT,and two kinds of biomechanical tests were used to evaluate the osteogenic effects.ResultsOne and five months after injection,BMD in mid-diaphysis significantly increased in simvastatin-injected groups compared to the control group.For Micro-CT analysis,significant increase in total bone volume/total tissue volume,cortical wall thickness,trabecular thickness,trabecular number,and a significant decrease in trabecular spacing were observed in simvastatin-injected groups compared to the control group.For both biomechanics (the three-pointbreaking test of condyles and axial compressive testing of proximal femur),the values were significantly higher in simvastatin-injected groups than the control group.ConclusionLocal simvastatin treatment showed a positive effect on improving mechanical strength,structure of osteopenic femurs and BMD.Our findings may provide a new strategy for the prevention and treatment of osteoporosis,especially for osteoporotic fractures.

Objective To clone and express the valuable Clonorchis sinensis antigen molecules which can be applied to the diagnosis of clonorchiasis. Methods Based on the sequences (Genbank) No. AF271091 (CysA) and No.AF093242 (CysB), primers were designed to amplify the two C. sinensis cysteine proteinase genes and expressed in E.cloi. The expressed proteins were purified by affinity chromatography and then tested for their immunological characters.Results The two genes were successfully cloned and expressed. Western blot showed that CysB had strong reaction with clonorchiasis sera and very weak reaction with schistosomiasis sera, while CysA showed no reactivity with the probed sera. Immunohistochemistry showed that both proteins were mainly located in adult worm intestines and the intrauterine eggs.Conclusions The results suggested that, of the two expressed C. sinensis proteins, CysB had good antigenic reactivity against sera from patients. It is a potential candidate of diagnostic antigens for clonorchiasis.

Objective:To investigate the clinical features and perinatal outcomes of twin pregnancies with complete placenta previa (CPP).Methods:We conducted a retrospective study on 266 women with CPP, including 62 twin pregnancies (twins group) and 204 singleton pregnancies (singleton group), who gave birth in Peking University Third Hospital from January 2012 to December 2020. T-test, nonparametric test and Chi-square test were adopted for univariate analysis. Differences between the two groups regarding clinical features and perinatal outcomes were compared using multivariate logistic regression or multivariate linear regression. Results:The incidence of twin pregnancy with CPP was 2.11% (62/2 937). Placenta accreta spectrum disorders (PAS) accounted for 48.4% (30/62) and 53.9% (110/204) in the twin and singleton group, respectively, but the difference was not statistically significant ( χ 2=0.58, P>0.05). In terms of antepartum hemorrhage, the proportion of women affected, those with first onset <29 weeks, amount of bleeding ≥200 ml, and the number of episodes of bleeding ≥3 were significantly higher in the twin group than those in the singletons [56.5% (35/62) vs 39.7% (81/204); 35.5% (22/62) vs 12.7% (26/204); 17.7% (11/62) vs 4.9% (10/204); and 21.0% (13/62) vs 10.3% (21/204), χ 2=5.42, 16.62, 10.78, and 4.86, respectively, all P<0.05]. Multivariate Logistic regression analysis showed that compared with the singleton group, the twin group was at higher risk of antepartum hemorrhage volume >200 ml, the number of antepartum hemorrhage episodes ≥3, preterm delivery before 34 weeks and 32 weeks, emergency cesarean section, and emergency cesarean section caused by antepartum hemorrhage [a OR(95% CI)=4.36(1.17-16.30), 3.15(1.01-9.79), 17.24(5.36-55.46), 9.85(2.32-41.77), 3.98(1.72-9.20), and 3.10(1.22-7.85), respectively, all P<0.05]. Multivariate linear regression analysis showed that the gestational week at the emergency cesarean section in the twins group was about 2.22 weeks (0.17-4.27 weeks) earlier than that in the singletons. The postpartum hemorrhage amount and the risk of postpartum hemorrhage after cesarean section, infusion of red blood cells, and hysterectomy did not differ significantly between the two groups. Conclusions:Compared with singleton pregnancies, the proportion of preterm delivery, cesarean sections, especially those caused by antepartum hemorrhage, is significantly higher among twin pregnancies combined with CPP. Accordingly, preterm delivery should be actively prevented, and the timing of cesarean section should be individualized according to the condition of the mothers and babies, and early delivery may be considered.

Gap junction (GJ) has been indicated to have an intimate correlation with adhesion junction. However, the direct interaction between them partially remains elusive. In the current study, we aimed to elucidate the role of N-cadherin, one of the core components in adhesion junction, in mediating connexin 43, one of the functional constituents in gap junction, via transforming growth factor-β1(TGF-β1) induction in osteoblasts. We first elucidated the expressions of N-cadherin induced by TGF-β1 and also confirmed the upregulation of Cx43, and the enhancement of functional gap junctional intercellular communication (GJIC) triggered by TGF-β1 in both primary osteoblasts and MC3T3 cell line. Colocalization analysis and Co-IP experimentation showed that N-cadherin interacts with Cx43 at the site of cell-cell contact. Knockdown of N-cadherin by siRNA interference decreased the Cx43 expression and abolished the promoting effect of TGF-β1 on Cx43. Functional GJICs in living primary osteoblasts and MC3T3 cell line were also reduced. TGF-β1-induced increase in N-cadherin and Cx43 was via Smad3 activation, whereas knockdown of Smad3 signaling by using siRNA decreased the expressions of both N-cadherin and Cx43. Overall, these data indicate the direct interactions between N-cadherin and Cx43, and reveal the intervention of adhesion junction in functional gap junction in living osteoblasts.
Cadherins ; Cell Communication ; Connexin 43 ; Osteoblasts ; Transforming Growth Factor beta1