Objective To evaluate the clinical effect of Wy 10 whitening combined with enamel microabrasion on bleaching dental fluorosis.Methods Forty patients with dental fluorosis were in-cluded and divided into two groups (20 each):group A was treated with Wy 10 whitening and enamel microabrasion,and group B only with Wy 10 whitening.Efficacy was measured according to the Vita classical shade guide before and after treatment.Sensitivity between groups was also tested.Results The effective rate of group A was significantly higher than that of group B (x2 =5.096,P＜0.05).The sensitive rates were 20.0％ (4/20) and 15.0％ (3/20) in group A and group B,respectively.No significant difference was found between the two groups in sensitivity (P＞0.05).Conclusions Wy 10 whitening combined with enamel microabrasion is an effective and safe method for bleaching dental fluorosis.

ObjectiveTo evaluate the therapeutic efficacy of low-dosage methyltestosterone or andriol in men with senile osteoporosis. MethodsA total of 134 male patients with senile osteoporosis and the decreased serum level of free testosterone were divided into three groups. 45 patients were treated with low-dosage methyhestosterone(100 mg, once a day, sublingual) and 46 patients were treated with low-dosage andriol (40 mg, once a day, orally), while 43 patients were treated with placebo. The duration of treatment in each group was 1 year. The bone density, blood and urine biochemical indexes related to bone metaholites,the quality of life indexes, ultrasonography for prostate,serum prostate specific antigen,blood routine, urine routine, hepatic and renal function were detected before and after the treatment. ResultsBoth low-dosage methyltestosterone and low-dosage andriol could prevent the decrease of bone mineral density and improve patients' general health, role-emotional function and vitality (all P＜0.05). The difference values of femoral neck bone mineral density before and after treatment with low-dosage andriol and low-dosage methyltestosterone were (0.14+0.18)g/cm2 and (0.12±0.09)g/cm2 , respectively(P＜0.05). Low-dosage andriol hadstronger effects in increasing the level of estradiol (32.5±14.2 )ng/L than low-dosage methyltestosterone(19.3±9.2)ng/L(P＜0.05) and showed more notable effects in improving the physical functioning and role-physical function than low-dosage methyhestosterone. The use of the two androgenic hormones at low dosage showed safety. ConclusionsBoth low-dosage methyltestosterone and low-dosage andriol can be used to treat senile osteoporosis in men and to improve life quality. Both of them are effective and safe therapeutic choices.

Objective To investigate the mechanisms of action of adiponectin on receptor activator of NF-Kb ligand(Rankl) and osteoprotegerin (OPG)expressions in human osteoblasts.Methods Real-time PCR was used to detect the expressions of RANKL and OPG mRNA in cultured human osteoblasts. The phosphorylations of JNK, p38 mitogen-activated protein kinase (MAPK) , ERK1/2 were assayed by Western blot. RNA interference for adiponectin receptor, MAPK inhibitors SB203580 and SP600125 were used for elucidating the mechanism of the action of adiponectin in regulating OPG and RANKL expressions. Results Suppression of adiponectin receptor-1 (AdR1) expression with siRNA abolished the adiponectin-regulated expressions of OPG and RANKL mRNA in human osteoblasts. Furthermore, pretreatment of osteoblasts with MAPK inhibitor SB203580 abolished the expressions of adiponectin-regulated RANKL and OPG mRNA, but SP600125 did not show the effect. Conclusion Adiponectin induces the expression of RANKL and inhibits the expression of OPG in human osteoblasts through AdR1/p38 MAPK pathways.

Objective To investigate the effect and mechnism of preptin on connect tissue growth factor (CTGF) in human osteoblasts. Methods Recombinant human preptin was used to treat primary human osteoblasts, and Western blot was used to detect CTGF protein level. Mitogen-activated protein kinase p38(p38MAPK), extracellular signal-regulated kinase (ERK1/2), c-jun N-terminal Kinase (JNK), and their phosphorylation levels were also detected by Western blot. MAPK inhibitors (PD98059, SP600125, or SB203580)were used to elucidate the mechnism of preptin induced expression of CTGF in human osteoblasts. Results Treatment of human osteoblasts with preptin caused a time and dose-dependent increase in CTGF secretion. Preptin induced activation of ERK, but not p38MAPK or JNK in human osteoblasts. Furhermore, pretreatment of human osteoblasts with the ERK inhibitor PD98059 abolished the preptin-induced CTGF secretion. Conclusion Preptin induces CTGF expression in human osteoblasts by means of ERK/MAPK pathway.

Objective To investigate the effect of preptin on proliferation and differentiation of human osteoblasts. Methods After human osteoblasts were incubated with 10-10, 10-9, 10-8 , 10-7 mol/L preptin for 24 h,the proliferation of osteoblasts was determined by[3H]thymidine incorporation and alkaline phosphatase (ALP)activity was assayed by spectrophotometric measurement. The phosphorylation levels of c-Jun N-terminal kinase (JNK), p38 mitogen-activated protein kinase ( MAPK), extracellular signal-regulated kinase (ERK) 1/2 were assayed by Western blot. ERK inhibitor PD98059, p38MAPK inhibitor SB203580, and JNK inhibitor SP600125were used for investigating the signal pathway of preptin-stimulated osteoblast proliferation and differentiation.Results Preptin dose-dependently increased human proliferation of osteoblasts and ALP activity with the maximum effect at the concentration of l0-9 mol/L (both P<0.01 ). Preptin stimulated ERK phosphorylation in human osteoblasts, but not p38 MAPK and JNK phosphorylation. PD98059 blocked preptin-sitmulated human osteoblasts proliferation and ALP activity (both P<0.05 ), while SB203580 and SP600125 had no effect. Conclusions Preptin promotes the proliferation and differentiation of human osteoblasts through ERK pathway.