Objective To study the influence of fluorine on signaling pathway of osteoprotegerin(OPG)/ receptor activator of NF-κB ligand(RANKL) in cultured rat osteoblasts.Methods Osteoblasts were isolated from skull of neonatal rats(＜ 24 hours) by enzyme digestion,and fluorine of different concentrations [0 (control),1 × 10-3,1 × 10-4,1 × 10-5,1 × l0-6 and 1 × 10-7 mol/L] were added into the culture medium of second generation of osteoblasts.The expressions of OPG and RANKL mRNA were determined using real-time PCR 24 and 48 hours after culturing.The expressions of OPG and RANKL protein were measured by Western blotting.Results ① After exposed to fluorine for 24 hours,the differences of RANKL and OPG mRNA expression had statistical significance between groups(F =30.95,22.62,all P ＜ 0.01),the expression of RANKL mRNA(5.99 ± 0.39) in the 1 × 10-5 mol/L group and the expressions of OPG mRNA(3.52 ± 0.09,4.81 ± 0.15,3.68 ± 0.04) in the 1 × 10-4,1 × 10-5 and 1 × 10-6 mol/L groups were higher than those of the control group(3.20 ± 0.19,3.09 ± 0.58,all P ＜ 0.05),but in the 1 × 10-3 mol/L group,RANKL mRNA(2.29 ± 0.18) was lower than that of the control group(P ＜ 0.05).After exposed to fluorine for 48 hours,the differences of RANKL and OPG mRNA expression had statistical significance between groups(F =26.62,5.72,all P ＜ 0.01),the expressions of RANKL and OPG mRNA(6.67 ± 0.49 and 5.05 ± 0.51) in the 1 × 10-5 mol/L group were higher than those of the control group(4.29 ± 0.07 and 4.34 ± 0.12,all P ＜ 0.05),and in the 1 × 10-3 mol/L group the expression of OPG mRNA(3.63 ± 0.49) was lower than that of the control group(P ＜ 0.05).② The expression of RANKL protein was not statistically significant between 24 hours and 48 hours groups (F =0.07,0.49,all P ＞ 0.05) ; the differences of OPG protein expression had statistical significance between groups(F =3.26,P ＜ 0.05),the expression of OPG protein in the 1 × 10-5 mol/L group(1.45 ± 0.10) was higher than that of the control group(1.05 ± 0.06,P ＜ 0.05) at the 24 hours.After 48 hours,the expression of OPG protein was not statistically significant(F =0.44,P ＞ 0.05).Conclusions At lower fluorine concentrations,bone formation is the main activity.But when fluorine concentration increased and time prolonged,the osteoclast differentiation and maturation are promoted,and the bone resorption is the main thing.

Objective To set up the rolling circle amplification (RCA) system for detecting hepatitis B virus (HBV) covalently closed circular DNA (cccDNA), and to evaluate the specificity and sensitivity of this system. Methods Plasmids containing full-length of wild-type HBV genome were treated with restriction enzyme and T4 DNA ligase, and then were concentrated. The DNA fragments were recovered by the nucleic acid purification kit and severed as standard HBV cccDNA. Total DNA was extracted from hepatic tissues of seven chronic hepatitis B patients. RCA method was used to amplify genomes from tissue samples. Standard HBV cccDNA, 3.2 kb liner HBV DNA, normal hepatic tissue samples and 15 serum samples of patients with chronic HBV infection were used as controls to determine the specificity of RCA. Ten-fold serial dilutions of standard HBV cccDNA were used for determining the sensitivity. Results The standard HBV cccDNA was successfully constructed and could be detected by RCA method. HBV cccDNA could be amplified from 2 mg hepatic tissue samples at least of HBV infected patients, and could be detected as low as 1 ×102 copy/μL. cccDNA was not detected in 3.2 kb liner HBV DNA, normal hepatic tissue samples and 15 serum samples of chronic HBV infected patients. Conclusion RCA method can be used for rapid and simple detection of HBV cccDNA with high specificity and sensitivity.

The proliferation difference between Human Umbilical Vein Endothelial Cells (HUVEC) and Human Umbilical Artery Smooth Muscle Cells (HUASMC) in response to the concentration of silver nanoparticles was investigated via MTT, BCA and FCM tests. The obtained experimental data were statistically analyzed and discussed in order to know the causation of the proliferation difference. The results show there is significant difference in proliferation between HUVEC and HUASMC corresponding to the concentration of silver nanoparticles, and such difference can be attributed to the varied adhesion shape and apoptosis of the cells being influenced by nano-Ag content and Fetal bovine serum (FBS) content in culture medium.
Cell Proliferation ; drug effects ; Cells, Cultured ; Dose-Response Relationship, Drug ; Human Umbilical Vein Endothelial Cells ; cytology ; Humans ; Metal Nanoparticles ; chemistry ; Muscle, Smooth, Vascular ; cytology ; Silver ; pharmacology ; Umbilical Arteries ; cytology