Effects of a simulated plateau environment on fracture healing in rats / 中华创伤骨科杂志

Objective:To study the effects of a simulated plateau environment on fracture healing in rats.Methods:A rat model of mid-femoral fracture was established by hacksaw truncation and intramedullary fixation with Kirschner wires in 60 male Wistar rats which were divide into 2 groups ( n=30) by the random number table method. The rats in the control group were raised in the animal experiment center of The 940 Hospital of Joint Logistic Support Force of Chinese PLA at an altitude of 1,400 m, while the rats in the plateau group were placed in an animal experimental cabin in a simulated plateau environment at a simulated altitude of 5,000 m. The body weight was weighed once a week and X-ray films were taken every 2 weeks. Blood samples were collected after 4 weeks for detection of biochemical indicators of bone metabolism. After 8 weeks, the femurs of the surgical side were taken for bone biomechanical detection and the bone mineral density of the healthy side was detected. After 4 and 8 weeks, the femurs of the surgical side were taken for in vitro Micro-CT scanning and angiography detection. After 1, 2, 4 and 8 weeks, the femurs of the surgical side were taken for bone histopathologic detection. Results:During the entire experiment, no rats in the control group died while the mortality rate of the rats in the plateau group was as high as 26.7% (8/30). In the plateau group, some organs were pathologically damaged in the rats, fracture union was delayed, and the callus differentiated and matured slowly with the chondrocytes still dominant at the 8th week. The bone mineral density and the maximum load of the femur in the plateau group were significantly lower than those in the control group ( P< 0.05). Angiography showed that the rats in the plateau group had microvascular proliferation which did not penetrate the fracture end at the 8th week. The bone formation indexes like osteocalcin, procollagen type Ⅰ N-terminal propeptide (PⅠNP), and osteoprotegerin of the rats in the plateau group were significantly lower than those in the control group at the 4th week ( P<0.05). The bone resorption indexes like tartrate resistant acid phosphatase 5b (TRACP-5b) and receptor activator for nuclear factor-κB ligand (RANKL) in the plateau group were significantly higher than those in the control group ( P<0.05). Conclusion:A simulated plateau environment at an altitude of 5,000 m may lead to delayed fracture healing in rats.

Effect of polycystin2 on differentiation and maturation of osteoblasts promoted by low-frequency pulsed electromagnetic fields / 生物工程学报

It is known that low-frequency pulsed electromagnetic fields (PEMFs) can promote the differentiation and maturation of rat calvarial osteoblasts (ROBs) cultured in vitro. However, the mechanism that how ROBs perceive the physical signals of PEMFs and initiate osteogenic differentiation remains unknown. In this study, we investigated the relationship between the promotion of osteogenic differentiation of ROBs by 0.6 mT 50 Hz PEMFs and the presence of polycystin2 (PC2) located on the primary cilia on the surface of ROBs. First, immunofluorescence staining was used to study whether PC2 is located in the primary cilia of ROBs, and then the changes of PC2 protein expression in ROBs upon treatment with PEMFs for different time were detected by Western blotting. Subsequently, we detected the expression of PC2 protein by Western blotting and the effect of PEMFs on the activity of alkaline phosphatase (ALP), as well as the expression of Runx-2, Bmp-2, Col-1 and Osx proteins and genes related to bone formation after pretreating ROBs with amiloride HCl (AMI), a PC2 blocker. Moreover, we detected the expression of genes related to bone formation after inhibiting the expression of PC2 in ROBs using RNA interference. The results showed that PC2 was localized on the primary cilia of ROBs, and PEMFs treatment increased the expression of PC2 protein. When PC2 was blocked by AMI, PEMFs could no longer increase PC2 protein expression and ALP activity, and the promotion effect of PEMFs on osteogenic related protein and gene expression was also offset. After inhibiting the expression of PC2 using RNA interference, PEMFs can no longer increase the expression of genes related to bone formation. The results showed that PC2, located on the surface of primary cilia of osteoblasts, plays an indispensable role in perceiving and transmitting the physical signals from PEMFs, and the promotion of osteogenic differentiation of ROBs by PEMFs depends on the existence of PC2. This study may help to elucidate the mechanism underlying the promotion of bone formation and osteoporosis treatment in low-frequency PEMFs.

Synergistic effect of sarcopenia and osteoporosis on spinal osteoporotic fracture in patients with rheumatoid arthritis / 中华风湿病学杂志

Objective:To investigate the synergistic effect of sarcopenia and osteoporosis on the occurrence of spinal osteoporotic fracture (OPF) in patients with rheumatoid arthritis (RA).Methods:A total of 389 hospitalized RA patients and 156 age and sex-matched normal subjects (control group) were recruited. Dual energy X-ray absorptiometry (DEXA) method was used to measure bone mineral density (BMD) of lumbar spine and hip, and bioelectrical impedance method was applied to determine skeletal muscle mass of limbs. X-ray examination of spin was conducted and spinal OPF was diagnosed according to semi-quality method. Student's t test was used for comparison of measurement date between the two groups, χ2 test was used for comparison of intergroup rates, and Logistic Regression(Backward LR) method was used for multivariate Regression analysis of binomial classification data. Results:BMD of all test sites in RA patients was significantly lower than that in the control group ( P<0.01). The incidence of total OP in RA group was significantly higher than that in the control group [(32.9% vs 12.8%), χ2=22.706, P<0.01]. A total of 84 patients with RA developed spinal OPF, with an incidence of 21.6% which was higher than that in the control group [(3.8%), χ2=25.439, P<0.01]. The incidence of sarcopenia in RA was 54.8%, significantly higher than that in the control group [(9.6%), χ2=93.241, P<0.01]. The incidence of sarcopenia combined with osteoporosis in RA group (28.5%) was significantly higher than that in the control group [(5.8%), χ2=118.110, P<0.01]. Comparison of the incidence of spinal OPF in RA patients among groups with different bone mass (normal bone mass, osteopenia, osteoporosis) showed that the incidence of spinal OPF among these groups was statistically different ( χ2=43.373, P<0.01), and the incidence of spinal OPF increased along with the decrease of bone mass ( χ2=43.003, P<0.01). The incidence of spinal OPF in RA patients with sarcopenia (27.2%, 58/213) was significantly higher than that in RA patients without sarcopenia [(14.8%, 26/176), χ2=8.833, P=0.003]. All participants were divided into three groups: group 1=no OP and sarcopenia, group 2=with sarcopenia or OP, group 3=both sarcopenia and OP. Difference of incidence of spine OPF in RA patients among three groups was statistically significant ( χ2=33.832, P<0.01), and the incidence of spinal OPF raised gradually in group 1 and 3, ( χ2=37.164, P<0.01). Incidences of sarcopenia, OP and spinal OPF in RA treated with glucocorticoid (GC) were higher than those in RA without GC ( P<0.05, P<0.01). Results of logistic regression showed advanced age[ OR(95% CI)=1.069(1.038, 1.101), P<0.01], usage of GC [ OR(95% CI)=3.169(1.679, 5.984), P<0.01] and sarcopenia combined with OP [ OR(95% CI)=2.113(1.430, 3.124), P<0.01] were risk factors for spinal OPF in RA patients. Conclusion:Incidences of sarcopenia, OP and spinal OPF in RA patients are higher than that in normal controls. Sarcopenia and OP have a synergistic effect on spinal OPF in RA patients.

Effects of compound medicine of icariin and puerarin on peak bone mass in growing rats / 中华内分泌代谢杂志

Objective To study the effects of the compound medicine of icariin and puerarin on peak bone mass in rats during growth period, and to explore its possible mechanism. Methods Forty female Sprague-Dawley rats aged 1 month were randomly divided into normal control group( C), icariin group( I), puerarin group( P), icariin and puerarin compound groupc(I+P), 10 in each group. The body weights were recorded once every two weeks, and the bone mineral density was measured by dual-energy X-ray absorptiometry every month. After the bone mineral density of the whole body was significantly different between the control group and drug groups the animals were sacrificed. The right femur and vertebrae were separated to measure the bone mineral density. The biomechanical properties of the femur and vertebra were detected by AG-IS series desktop electronic universal testing machine. The bone formation index osteocalcin, PINP and bone resorption index were determined by ELISA. Changes in the contents of tartrate-resistant acid phosphatase 5b(TRACP 5b) and CTX-1; and changes in trabecular bone related parameters were recorded after magenta-picric acid staining. Results There was no significant difference in body weight between the two groups (P＞0.05). There was no significant difference in whole body bone density after 1 month of treatment (P＞0.05). After 2 months of treatment, the body bone density of the drug-administered group was higher than that of the control group. Whole body bone density, femur and vertebral bone density, femur maximum load value, maximum vertebrae load value and trabecular bone number and area, serum OC and PINP levels increased, while TRACP 5b and CTX-1 levels decreased(P＜0.01) in drug group. The difference from the control group was statistically significant (P＜0. 05). There were significant differences in biochemical parameters and bone histomorphology between the compound drug group and the two-flavor monomer group ( P＜0. 01). There was no significant difference in bone mineral density and biomechanics, but the average value was higher than that of the monomer group. Conclusion The combination of icariin and puerarin can effectively increase the peak bone mass in rats.

Effect of low-frequency pulsed electromagnetic fields on activity of rat calvarial osteoblasts through IGF-1R/NO signaling pathway / 浙江大学学报·医学版

OBJECTIVE@#To investigate the effect of low-frequency pulsed electromagnetic fields (PEMF) on the maturation and mineralization of rat cranial osteoblasts and its relation to IGF-1R/NO signaling pathway.@*METHODS@#The rat osteoblasts were isolated and cultured and randomly divided into blank control group, PEMF group, GSK group (IGF-1R blocker) and PEMF+GSK group. The cells were treated with 50 Hz 0.6 mT PEMF for 1.5 h/d. After 3 d of PEMF treatment, the expressions of protein kinase (AKT), inducible nitric oxide synthase (iNOS) and cGMP-dependent protein kinase (PKG) were detected by Western blotting; on 6 d of PEMF treatment alkaline phosphatase (ALP) activity was determined; on 12 d of PEMF treatment the calcification nodule formation was demonstrated by Alizarin red staining.@*RESULTS@#NO level was significantly increased in rat osteoblasts treated with 50 Hz 0.6 mT PEMF for 1.5 h/d. Western blot analysis showed that the expressions of AKT, iNOS and PKG protein in PEMF group were higher than those in the control group (all <0.01); the ALP activity was increased(<0.05), and the PEMF group had the largest area of Alizarin red staining (<0.01). The expressions of AKT, iNOS and PKG protein in GSK group were lower than those in the control group; the ALP activity was decreased (<0.05), and the GSK group had the least area of Alizarin red staining (<0.01). The expressions of AKT, iNOS, PKG protein, the ALP activity and the area of Alizarin red staining in PEMF+GSK group were between PEMF group and GSK group.@*CONCLUSIONS@#PEMF may enhance the maturation and mineralization of rat cranial osteoblasts through IGF-1R/NO signaling pathway.

Effects of sinusoidal electromagnetic fields at different exposure times on osteoblastic activity and the underlying signal transduction mechanisms / 中华老年医学杂志

Objective@#To investigate the signal transduction mechanisms of time-dependent effects of 50 Hz 1.8 mT sinusoidal electromagnetic fields(SEMFs)on osteoblastic activity.@*Methods@#Newborn rat calvarial osteoblasts(ROBs)were treated with 50 Hz 1.8mT SEMFs for 30, 60, 90, 120, and 150 min, respectively.Intracellular alkaline phosphatase(ALP)activity was assayed, and protein expression of Runt-related transcription factor 2(Runx2), Smad1/5/8 and mitogen-activated protein kinases(MAPKs)were examined by Western blot.The Dual-Luciferase Reporter Assay System was used to measure the activity of the Wnt pathway.Immunofluorescence staining and laser confocal microscopy were applied to examine the nuclear translocation of Smad1/5/8 and β-catenin.Changes in ALP activity were determined after inhibiting p38 MAPK using a specific inhibitor.@*Results@#ALP activity of ROBs increased after 30, 60, 90, 120 and 150 min of SEMFs treatment, compared with the control group(51.41±5.21, 59.47±4.02, 67.56±4.68, 63.69±3.92, and 58.16±3.61 vs.45.53±3.24), and reached the highest value at 90 min and then started to decline.Protein expression of Runx-2, p-Smad1/5/8, p-p38 and β-catenin increased after SEMFs treatment, and reached the highest value at 90 min and then gradually returned to baseline levels.The values for Wnt pathway activity for the control group and with SEMFs treatment at 30, 60, 90, 120 and 150 min were 0.49±0.06, 0.52±0.09, 0.75±0.05, 0.77±0.42, 0.58±0.08 and 0.42±0.09, respectively.Wnt pathway activity, the nuclear translocation of β-catenin and Smad1/5/8 reached the highest level at 90 min.Values of ALP activity in the control group and the SEMFs group were 44.60±3.84 and 71.54±7.34, respectively, before specifically inhibiting p38 MAPK, and were 52.08±0.83 and 52.15±10.77, respectively, after p38 MAPK inhibition, indicating that ALP activity could not be increased with inhibition.@*Conclusions@#50 Hz 1.8 mT SEMFs increase osteoblastic activity by activating the BMP-2/Smad1/5/8, Wnt/β-catenin and p38 MAPK signal pathways.The optimal duration of treatment is 90 min per day.

Effects of sinusoidal electromagnetic fields at different exposure times on osteoblastic activity and the underlying signal transduction mechanisms / 中华老年医学杂志

Objective To investigate the signal transduction mechanisms of time-dependent effects of 50 Hz 1.8 mT sinusoidal electromagnetic fields(SEMFs)on osteoblastic activity.Methods Newborn rat calvarial osteoblasts(ROBs) were treated with 50 Hz 1.8mT SEMFs for 30,60,90,120,and 150 min,respectively.Intracellular alkaline phosphatase (ALP) activity was assayed,and protein expression of Runt-related transcription factor 2 (Runx2),Smad1/5/8 and mitogen-activated protein kinases(MAPKs)were examined by Western blot.The Dual-Luciferase Reporter Assay System was used to measure the activity of the Wnt pathway.Immunofluorescence staining and laser confocal microscopy were applied to examine the nuclear translocation of Smad1/5/8 and β-catenin.Changes in ALP activity were determined after inhibiting p38 MAPK using a specific inhibitor.Results ALP activity of ROBs increased after 30,60,90,120 and 150 min of SEMFs treatment,compared with the control group(51.41±5.21,59.47±4.02,67.56[4.68,63.69±3.92,and 58.16±3.61 vs.45.53± 3.24),and reached the highest value at 90 min and then started to decline.Protein expression of Runx-2,p-Smad1/5/8,p-p38 and β-catenin increased after SEMFs treatment,and reached the highest value at 90 min and then gradually returned to baseline levels.The values for Wnt pathway activity for the control group and with SEMFs treatment at 30,60,90,120 and 150 min were 0.49± 0.06,0.52 ± 0.09,0.75±0.05,0.77 ± 0.42,0.58 ± 0.08 and 0.42 ± 0.09,respectively.Wnt pathway activity,the nuclear translocation of β-catenin and Smad1/5/8 reached the highest level at 90 min.Values of ALP activity in the control group and the SEMFs group were 44.60±3.84 and 71.54±7.34,respectively,before specifically inhibiting p38 MAPK,and were 52.08±0.83 and 52.15±10.77,respectively,after p38 MAPK inhibition,indicating that ALP activity could not be increased with inhibition.Conclusions 50 Hz 1.8 mT SEMFs increase osteoblastic activity by activating the BMP-2/Smad1/5/8,Wnt/β-catenin and p38 MAPK signal pathways.The optimal duration of treatment is 90 min per day.

Expression of EIF5A2 in Esophageal Squamous Cell Carcinoma and Its Correlation with the Prognosis / 中山大学学报(医学科学版)

[Objective] To investigate the expression of eukaryotic translation initiation factor 5A2 (EIF5A2) and its clinical significance in esophageal squamous cell carcinoma (ESCC).[Methods] Immunohistochemistry was used to detect the expression of EIF5A2 protein in 135 cases of esophageal squamous cell carcinoma,and analyzed the correlation between the expression of EIF5A2 protein and clinicopathological parameters,and its prognosis value.[Results] Immunohistochemical analysis showed that 68 cases were overexpressed in 135 cases of ESCC.Pearson's chi-square test indicated that the expression of EIF5A2 in ESCC was significantly correlated with T stage (P =0.006),lymph node metastasis (P =0.031) and clinic stage (P =0.026).The Cox proportional hazard model analysis showed that EIF5A2 was an independent prognostic risk factor for ESCC patients.Kaplan-Meier analysis showed that the median survival time of patients with the low expression was 72.5 months,which was significantly higher than that of patients with the high expression,the median survival time of it are 51.7 months (P ＜ 0.05).[Conclusion] The overexpression of EIF5A2 may contribute to the development and progression of ESCC and EIFSA2 could be a novel potential prognostic marker for ESCC.

Bone Density Measurement Based on Material Decomposition Images of Spectral CT / 中国医学影像学杂志

Purpose To explore the value of hydroxyapatite (HAP) in the measurement of bone mineral density (BMD) based on the quantitative material decomposition images of spectral CT on healthy adult females.Materials and Methods A total of 128 healthy females who underwent upper abdominal CT examination with spectral CT at the Second Hospital of Lanzhou University from September 2013 to February 2016 were enrolled as the research group.Those patients with trauma,surgery,tumor or other diseases affecting BMD were excluded.The patients (ages ranged from 18 to 87 years) were divided into 6 groups according to their ages:＜30 years (n=23),30-39 years (n=20),40-49 years (n=22),50-59 years (n=24),60-69 years (n=19) and ≥ 70 years (n=20).The HAP and calcium concentration at central part of L2 centrum of spongy bone were measured.Meanwhile,119 healthy females who underwent dual energy X-ray absorption (DEXA) examination were selected as the controls and also divided into groups according to the same criteria as the research group.The BMD of the controls was also measured at L2 centrum and showed as areal density (g/cm2).The measurements of the research group were analyzed.The correlation analysis was done between hydroxyapatite,calcium concentration and age.The correlations between hydroxyapatite,calcium concentration and BMD obtained by DEXA were also analyzed.Results There were significant differences in the HAP and calcium concentration among different age groups (P＜0.05).The results of spectral CT and the DEXA showed correlations.Both HAP and calcium concentration showed positive relationship with BMD obtained by DEXA (r=0.874 and 0.796,respectively,both P＜0.05).The HAP and calcium concentration showed positive relationship with age in the groups (ages ranged from 18-39 years) (r=0.538 and 0.416,P＜0.05) and negative relationship with age in the groups (ages over 40 years) (r=-0.629 and-0.562,P＜0.05).Conclusion Material decomposition images of spectral CT can reflect bone changes,and HAP is a new base material for BMD measurement.

Icaritin promotes maturation and mineralization of mouse osteoblast MC3T3-E1 cells through CXCR4/SDF-1 signal pathway / 浙江大学学报·医学版

Objective: To investigate the effect of icaritin on maturation and mineralization of mouse osteoblast MC3T3-E1 cells and its mechanism. Methods: The cultured MC3T3-E1 cells were divided into blank control group, CXC chemokine receptor type 4 (CXCR4) inhibitor (AMD3100) group, icaritin group, and icaritin plus AMD3100 group. The expression of CXCR4, stromal cell-derived factor 1 (SDF-1) and osteogenesis-related genes and proteins were detected by real-time RT-PCR and Western blotting after drug treatment for 24 h. The alkaline phosphatase (ALP) activity was determined with ALP kit on d3 and d6; calcium nodules were detected by alizarin red staining after drug treatment for 14 d. Results: Real time RT-PCR showed that compared with the blank control group, relative expressions of CXCR4, SDF-1 and osteogenesis-related genes in icaritin group were significantly increased (PPCXCR4 gene was decreased (PPPPPConclusion: Icaritin may promote maturation and mineralization of mouse osteoblast MC3T3-E1 cells through CXCR4/SDF-1 signaling pathway.

Effect of resveratrol on peak bone mass in growing rats / 浙江大学学报·医学版

Objective: To investigate the effect of resveratrol on peak bone mineral density and bone mass in growing rats. Methods: Thirty-six female healthy Wistar rats were randomly divided into control group, icariin group and resveratrol group with 12 rats in each group. Icariin (25 mg·kg-1·d-1), resveratrol (8.4 mg·kg-1·d-1) or equal volume of distilled water were given by gavage to icariin group, resveratrol group and control group, respectively. The rats were sacrificed after 12 weeks. The organ indexes were calculated and pathology sections were observed; the bone mineral density (BMD), bone biomechanics, serum bone metabolism index, and results of micro-CT scan were analyzed. Results: During the experiment, the body weight of rats showed an increasing trend and there was no significant difference among three groups (P0.05). There were no significant differences in organ index of vital organs and pathological changes among the groups (all P0.05). Compared with the control group, the whole body BMD, and the BMDs of femur and vertebrae in icariin and resveratrol groups were significantly increased after 12 weeks (all PPPPPPPConclusion: Resveratrol can inhibit bone resorption and enhance bone formation, so as to improve the peak bone mass and bone density, enhance bone strength and improve the microstructure of bone tissue in young rats.

Effect of low frequency low intensity electromagnetic fields on maturation and mineralization of rat skull osteoblasts in vitro / 浙江大学学报·医学版

Objective: To compare the effects of 50 Hz 1.8 mT sinusoidal magnetic field (SEMF) and 50 Hz 0.6 mT pulsed electromagnetic field(PEMF) on the maturation and mineralization of rat calvaria osteoblasts. Methods: Primary cultured rat calvarial osteoblasts were divided into 3 groups:blank control group, SEMF group and PEMF group. The rats in SEMT and PEMT groups were treated with 50 Hz 1.8 mT SEMF or 50 Hz 0.6 mT PEMF for 90 min/d, respectively. Western blotting and Real-time RT-PCR were used to detect the protein and mRNA expressions of Collagen-1, bone morphogenetic protein 2 (BMP-2), osterix (OSX) and Runt-associated transcription factor 2(Runx-2). The alkaline phosphatase(ALP) activity was detected by ALP test kits at d6 and d9 after treatment, and by ALP staining using azo coupling at d10 after treatment. The formation of calcium nodules was observed by alizarin red staining. Results: Compared with blank control group, the protein and mRNA expressions of Collagen-1, BMP-2, OSX and Runx-2 in SEMT and PEMT groups were significantly increased (P P PP0.05); after 9 days treatment, the activities of ALP in both PEMF and SEMP groups were significantly higher than that in blank control group (all PP0.05). After 10 days treatment, ALP staining was increased in both PEMF and SEMF groups compared with that in blank control group (all PPPPConclusion: Both 50 Hz 1.8 mT that in SEMF and 50 Hz 0.6 mT PEMF can promote the maturation and mineralization of osteoblasts, and the effect of PEMF is more marked.

Primary cilium acts as an oxygen sensor in PC12 cells / 浙江大学学报·医学版

Objective: To investigate the function of primary cilium as an oxygen sensor in PC12 cells. Methods: The PC12 cells were transfected with IFT88 siRNA. The nuclear translocation of hypoxia inducible factor-1α (HIF-1α), nuclear factor erythroid-2 related factor 2 (Nrf2), and ciliogenesis were observed by immunofluorescence staining; and the mRNA expressions of HIF-1α, Nrf2, vascular endothelial growth factor (VEGF) and superoxide dismutase (SOD) were detected by real-time RT-PCR. Results: The ciliogenesis was inhibited in PC12 cells transfected with IFT88 siRNA. In hypoxia group and scramble control group, nuclear translocations of HIF-1α and Nrf2 were observed and mRNA expressions of HIF-1α, Nrf2, VEGF were increased, and those of SOD were decreased. While in PC12 cells transfected with IFT88 siRNA, nuclear translocations of HIF-1α and Nrf2 were not observed, and mRNA expressions of HIF-1α, Nrf2, VEGF were inhibited, and mRNA expression of SOD was increased. Conclusion: Primary cilia may act as an oxygen sensor to transfer the information related to hypoxia and oxidative stress into cells, activating intracellular defense mechanism against the hypoxic injuries.

Genic and non-genic regulation of low frequence pulsed electromagnetic fields on osteoblasts differentiation / 浙江大学学报·医学版

To study the genic and non-genic regulation of 50 Hz 0.6 mT pulsed electromagnenic fields (PEMF) on rat calvarial osteoblasts (ROB) differentiation.ROBs were achieved by enzyme digestion, and treated with 50 Hz 0.6 mT PEMFs for 1.5 hours after subculture. The alkaline phosphatase (ALP) activity, mRNA transcription of ALP, Runx2 and OSX and protein expression of Runx2 and OSX were detected at 0, 3, 6, 9 and 12 hours after PEMF treatment.The ALP activity at 3 hours after treatment was significantly higher than that in the control(<0.01), while the mRNA transcription of ALP began to increase at 6 hours after treatment. The mRNA transcription of Runx2 increased immediately after treatment and regressed at 6 hours, then increased again. The protein expression of it corresponded but with a little lag. The mRNA transcription of OSX also raised instantly after treatment, then returned to the level of control at 6 hours, and lower than control at 12 hours significantly. The protein expression of it also corresponded but with a bit delay.There are genic regulation for the protein expression of Runx2 and OSX, and non-genic regulation for the ALP activity on the process of 50 Hz 0.6 mT PEMFs prompts ROBs differentiation.

Effects of icariin total flavonoids capsule on bone mineral density and bone histomorphometry in growing rats / 浙江大学学报·医学版

To investigate the effect of icariin total flavonoids capsules (ITFC) on bone mineral density (BMD) and bone histomorphometry in growing rats and its anti-osteoporosis mechanism.Thirty female SD rats were randomly divided into 3 groups:normal control group, ITFC-1 group and ITFC-2 group. Rats in ITFC-1 group and ITFC-2 group were fed with 50 mg·kg·dor 100 mg·kg·dITFC, respectively, and those in normal control group were fed with equal volume of distilled water. The whole body BMD was measured after 4, 8 and 12 weeks, and BMDs of the right femur and lumbar vertebrae were measured after 12 weeks. The serum levels of tartaric acid phosphatase 5b (TRACP 5b) and bone alkaline phosphatase (BALP) were measured by ELISA. Bone morphometry was performed on the right tibia.There were no significant differences in the body weight increase between normal control group and two ITFC groups (all>0.05). There were also no significant differences in whole body BMDs after 4 and 8 weeks between normal control group and ITFC groups (all>0.05). After 12 weeks, the whole body BMD, BMD of bone, serum BALP level and trabecular area in ITFC-1 group and ITFC-2 group were significantly higher, trabecular separation was significantly lower than that in normal control group (all<0.05); and the trabecular width and the number in ITFC-2 group were also significantly higher, and serum TRACP 5b level was significantly lower than that in normal control group (all<0.05). The BMD of bone, serum BALP level, trabecular number and area in ITFC-2 group were significantly higher, and serum TRACP 5b level was significantly lower than that in ITFC-1 group (all<0.05).ITFC can prevent osteoporosis by increasing bone density and bone formation, decreasing bone resorption and improving microstructure of bone.

Effects of 1.8 mT sinusoidal alternating electromagnetic fields of different frequencies on bone biomechanics of young rats / 浙江大学学报·医学版

To study the effects of 1.8 mT sinusoidal electromagnetic fields of different frequencies on bone mineral density (BMD) and biomechanical properties in young rats.A total of 32 female SD rats (6-week-old) were randomly divided into 4 groups (8 in each):control group, 10 Hz group, 25 Hz group and 40 Hz group. The experimental groups were given 1.8 mT sinusoidal electromagnetic field intervention 90 min per day. The whole body BMD of rats was detected with dual-energy X-ray absorptiometry after 4 and 8 weeks of intervention. After 8 weeks of intervention, all rats were sacrificed, and the BMD of femur and lumbar vertebra, the length and diameter of femur, the width between medial and lateral malleolus were measured. Electronic universal material testing machine was used to obtain biomechanical properties of femur and lumbar vertebra, and micro CT scan was performed to observe micro structures of tibial cancellous bone.Compared with the control group, rats in 10 Hz and 40 Hz groups had higher whole body BMD, BMD of femur, maximum load and yield strength of femur, as well as maximum load and elastic modulus of lumbar vertebra (all<0.05). But no significant differences in the length and diameter of femur, and the width between medial and lateral malleolus were observed between control group and experimental groups (all>0.05). Micro CT scan showed that the trabecular number and separation degree, bone volume percentage were significantly increased in 10 Hz and 40 Hz groups (all<0.01). Rats in 25 Hz group also had higher BMD and better in biomechanical properties than control group, but the differences were not statistically significant (all>0.05).10 and 40 Hz of 1.8 mT sinusoidal electromagnetic field can significantly improve the bone density, microstructure and biomechanical properties in young rats.

Effects of 50 Hz sinusoidal electromagnetic field with different intensities on rat peak bone mass / 生物医学工程学杂志

Studying effects of 50 Hz sinusoidal electromagnetic fields (SEMFs) with different intensities on peak bone mass (PBM) of rats may provide a theoretical basis for application of electromagnetic clinical field. 30 female SD rats, 6 weeks of age, were randomly divided into three groups: the control group, 0.1 mT electromagnetic field group (EMFs) and 0.6 mT EMFs. The EMFs groups were treated for 3 h/day. After 8 weeks, we examined their bone mineral densities (BMD) , measured their bone biomechanical properties, and made serum levels of osteocalcin (OC), tartrate-resistant acid phosphatase 5b (TRACP 5b), and histomorphometry. It was found that the BMD (P < 0.01), maximum mechanical load (P < 0.01) in the 0.1 mT group were significantly higher than those in the control group, and Yield strength (P < 0.05), the analyses of serum bone turnover markers and histomorphometric parameters were better than those in the control group (P < 0.05). However, the 0.6 mT group did not have significantly difference comparing with that in the control group. This study proved that 50 Hz 0.1 mT SEMFs can increased BMD, bone strength, and bone tissue microstructure. Therefore, 50 Hz 0.1 mT SEMFs can improve peak bone mass of rats.

Effect of icariin and genistein on bone protection / 中国药理学通报

Aim To compare the pharmacological ac-tivity of icariin( ICA) and genistien ( GEN) against os-teoporosis after oral administration with them to growing rats and ovariectomized rats. Methods 25 mg·kg-1 icariin and 10 mg · kg-1 genistein ( equal in molar concentration) were administered to one-month-old fe-male SD rats every day for three months. Treatments at the same dosage were administered to the 6-month-old ovariectomized SD rats every day for three months. Their effects were compared on bone mineral density and biomechanical properties of femurs and vertebrae, serum levels of osteocalcin and tartaric acid phospha-tase 5b ( TRACP 5b) and histomorphometry. Results The results showed that, in young rats, icariin treat-ment significantly increased bone mineral density, the maximum mechanical loads of femurs and vertebrae as well as the bone qualities ( serum markers and microar-chitecture ) , whereas genistein treatment had little effects compared with the non-treatment control. How-ever, genistein treatment was more efficacious than icariin in preventing bone loss and deterioration of bone microarchitecture in ovariectomized rats. Conclusion Our data suggest that, since icariin has a higher os-teogenic activity but lower estrogenic activity, it has been found to be more efficacious than genistein in peak bone mass accrual only in young rats. In the ovariectimized rats, however, as the main force to pre-vent bone loss is the estrogenic activity, genistein has been found to be more efficacious than icariin in reduc-ing bone loss.

Effect of genistein on rat femoral bone metabolic activity in vitro / 药学学报

This study is to investigate effects of genistein on rat femoral bone metabolic in vitro. Rat femoral tissues was isolated and randomly divided into two groups including control group and genistein (1 x 10(-5) mol x(-1)) group. Determinations of alkaline phosphatase (ALP) activity, calcium content and osteoprotegerin (OPG), type I-collagen (Collagen-I), RANKL, Runx-2 and bone morphogenetic protein (BMP-2) mRNA expression were done by real-time PCR. The results showed that 1 x 10(-5) mol x L(-1) genistein could increase the activity of ALP and contents of Ca, regulate bone metabolism activity of OPG, RANKL, BMP-2, Collagen-I and Runx-2 mRNA expression level. Genistein can significantly modulate bone metabolism related gene expression level of rat femoral tissue in vitro, and can increase calcium content and the activity of ALP.

Inhibitory effect of 8-prenylnaringenin on osteoclastogensis of bone marrow cells and bone resorption activity / 药学学报

This study is to investigate the effect of 8-prenylnaringenin (8-PNG) on osteoclastogensis of bone marrow cells and bone resorption activity of osteoclasts. Osteoclasts were separated from long bone marrow of newborn rabbits and cultured in alpha-MEM containing 10% FBS. 8-PNG was added into culture media at 1 x 10(-7), 1 x 10(-6), 1 x 10(-5) mol xL(-1), separately. 17beta-Estradiol (E2, 1 x 10(-7) mol x L(-7)) was used as positive control. T RAP staining and TRAP activity measurement were performed after 5 days, and the bone resorption pits were analyzed after 7 days. Annexin V staining for the detection of apoptotic osteoclasts was performed after 2, 4, 8, 12, 24, 36 and 48 h separately. The mRNA expression level of TRAP and cathepsin K (CTSK) was measured by real-time RT-PCR. 8-PNG significantly reduced the number of osteoclasts which was TRAP staining positive and with more than three nucleus, the area and number of bone resorption pits decreased obviously in 8-PNG-supplemented groups. The apoptosis rate peaked earlier in the 8-PNG-supplemented groups and the mRNA expression level of TRAP and CTSK decreased significantly. All these inhibitory effects were in a dose dependent manner, the highest effect was obtained by 1 x 10(-5) mol x L(-1) 8-PNG. 8-PNG inhibits bone resorption activity of osteoclasts by inducing osteoclast apoptosis and inhibiting the gene expression and enzyme activity including TRAP and CTSK, and restrains bone marrow cells to osteoclast differentiation.