Objective To observe and analyze the effect of dexamethasone on the adult osteoblast proliferation and differentiation in vitro. Methods Iliac trabecular bone specimens were obtained from eight adult patients undergoing scheduled surgery. After the bone pieces were treated with collagenase trypsin, larage numbers of osteoblasts were released out. Then the osteoblasts were purified and their passages were fed with DMED-F12 and fetal bovine serum. The cells were incubated under the condition of 37 ℃, 95% relative humidity and 5% CO2. Subsequently, 1?10-8 mol/L dexamethasone were added into culture medium to feed eight groups of osteoblasts for three days and the control groups were cultured not to add medicine at the same time. All the groups were observed continually under light microscope and transmission electron microscope. Finally, apoptosis detection was performed by use of the terminal deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL) and biochemical indexes alkaline phosphatase (ALP) and osteocalcin (OCN), were assayed to check if dexamethasone has any effect on proliferation and differentiation of osteoblasts in vitro. Results Of the adult osteoblasts obtained by collagenase trypsin method, the survival condition was good, the biochemical indexes were stable, the degree of purification was excellent, and they were fit for the next step study. The following data demonstrated that under the condition of dexamethasone 1?10-8 mol/L and osteoblasts 10 000 /ml, there were significant increase of ALP and OCN secretion without apoptosis alteration. Conclusion Dexamethasone has significant promoting effect on proliferation and differentiation of adult osteoblasts in vitro without apoptosis alteration and could be used as positive control during screening research of osteoporosis.

BACKGROUND: To search for an alloxenogeneic bone with good load bearing function and osteoblastic activity for treating bone defects is an important study issue. We have made a comparative study on its biome chanical characteristics and found that there was no significant difference in maximum load stress, maximum pressure as compared with fresh bone of the same size. Clinicians are concerned about the osteoblastic activity and whether the osteoblastic activity can be reserved after human allogenous a cellular bone (HAB) loaded with bone marrow stromal cells (BMSCs). OBJECTIVE: To investigate the experimental effect of HAB loaded with induced BMSCs, and observe the cellular adherence and growth as well as detect its osteoblastic activity. DESIGN: Single sample experiment. SETTING: Second Affiliated Hospital of Harbin Medical University. MATERIALS: This experiment was conducted at the Experimental Center of the Second Affiliated Hospital of Harbin Medical University between January 2003 and August 2004. HAB was obtained from fresh corpse iliac bones (donated voluntarily). METHODS: Connective tissues and cell compounds of the iliac bones were removed by processing with hydroperoxide andether solution and sterilized for preparing HAB. BMSCs from living femoral shaft bone marrow were cultured immediately in ordinary and mineralized medium containing DMEM, fetal bovine serum, dexomethasone, β-glycerophophate and ascor bic acid. Proliferation and differentiation of bone stromal cells were deter mined by detecting the level of alkaline phosphatase (ALP) and osteocalcin (OCN) in the culture medium. Induced bone stromal cells solution was condensed and implanted within HAB scaffold. Cellular osteoblastic activ ity was determined through morphological observation under the light mi croscope and electron microscope as well as biochemical index detection. MAIN OUTCOME MEASURES: ① Detection results of ALP and OCN of BMSCs/HAB composite. ② Histological observation results of BMSCs/ HAB composite. RESULTS: ① Iliac bone block cells were cleaned with good reservation of bone matrix. ② The level of ALP and OCN of MSCs was higher after in ducing for 8 days than that in control group [MSCs after induction: (181.54±40.01) nkat/L, (7.2±1.3) μg/L. There was no method to detect the level in control group, P ＜ 0.05]. ③ BMSCs were adhered and grew well in HAB scaffold. CONCLUSION: HAB loaded with induced BMSCs has an excellent os teogenic function in vitro and shows an effective potential as a good bone tissue engineering material.

BACKGROUND: Incidence rate of cervical osteoarthritis in the middleaged and elderly is high. Some researches on risk factor causing cervical osteoarthritis have been performed abroad, but most of the factors are being discussed.OBJECTIVE: To investigate the occurring cervical osteoarthritis risk factors in the middle-aged and elderly from different regions of China and provide evidences for prevention and intervention of cervical osteoarthritis in community.DESIGN: Cross-sectional study.SETTING: Beijing Hospital, Ministry of Health, together with Second Hospital of Xi'an Jiantong University, Institute of Integrated Traditional and Western Medicine of Hebei Medical University, Shanghai Huadong Hospital, Nanfang Hospital, Second Affiliated Hospital of Harbin Medical University, West China Hospital of Sichuan University.PARTICIPANTS: The investigation was conducted from July to August2005. On the basis of stratified multi-stage cluster sampling method, 6 218formal registered permanent residents of over 40 years old from Xi'an,Shijiazhuang, Shanghai, Guangzhou, Harbin and Chengdu were enrolled.They all agreed to join the investigation voluntarily. There were 2 916males of 40-94 years and 3 302 females of 40-86 years.METHODS: Questionnaire investigation of epidemiology of cervical osteoarthritis was performed in the testees, and radiograph was used in the persons with clinical symptom. The basic sample unit was neighborhood committee (city) and village committee (countryside). Sampling method:Taking each city as a whole, composed of two levels, namely city and countryside, in the first phase the persons were extracted from district (county),in the second phase from sub-district (countryside), in the third phase from neighborhood committee (village eommittee). Diagnosis standard of cervical osteoarthritis was positive clinical symptom and 2 grade or above of radiograph Kellgren & Lawrence grading. The content of questionnaire contained 6 aspects: general condition, history of present illness, history of past illness, physical check-up, radiographs and disease diagnosis, totally94 questions and 141 variation indexes. Influential factors of prevalence rate of cervical osteoarthritis were analyzed using multifactor non-conditional Logistic regression analysis. Odds ratio (OR) was used for expressing index of strength of relationship between disease and exposures. If OR ＞ 1,it was indicated that there was positive correlation between disease occurrence and exposures. If OR ＜ 1, it was suggested that there was negative correlation between disease occurrence and exposures.MAIN OUTCOME MEASURES: Prevalence rate of cervical osteoarthritis in each city and OR.RESULTS: Totally 6 218 investigational subjects were included in the result analysis, without drop out. ①Total prevalence rate of cervical osteoarthritis in population of 40 years or above from 6 domestic cities was23.6%. There was significnat difference of prevalence rate in each city (P＜0.01). ②Result of Logistic regression analysis: Age (OR=1.010-1.058),defecation with squat ting pot (OR =1.024-1.997) and history of hypertension (OR =1.815-3.078) were common risk factor in most areas. In northern area the common risk factor compos ed of daily stair climbing or grade climbing (OR =1.018-1.020), while drinking colored wine (OR=3.451, Xi'an), history of osteoarthri tis of father (OR =2.491, Xi'an), history of diabetes (OR =5.013, Shijiazhuang), history of osteoarthritis of mother (OR =2.045, Shanghai), smoking (OR =6.857, Guangzhou), age of starting drinking (OR =3.044, Guangzhou) and full-time athletic sports (OR=9.020, Harbin), etc. emerged in different areas.CONCLUSION: The onset of cervical osteoarthritis has the same risk factor in 6 domestic areas, and main risk factor in different areas has certain differences, which can provide reference data for the prevention and cure of cervical osteoarthritis for the future and reduce waster of medical resources.

OBJECTIVETo observe the effects of dexamethasone on proliferation, differentiation and apoptosis of adult human osteoblasts in vitro.

METHODSIliac trabecular bone specimens were obtained from adult patients undergoing necessary surgery. After the bone pieces were digested with collagenase-trypsin, osteoblasts were released and incubated at 37 degrees C in a relative humidity of 95% and 5% CO2. Then, the cells were purified, and their passages were given DMEM-F12 and fetal bovine serum medium. Subsequently, 10(-8) mol/L dexamethasone was added into the culture medium to incubate the osteoblasts for three days, and the cells from control groups were incubated without any drugs. All cells were observed continually with phase contrast microscope and transmission electron microscope. Finally, apoptosis was detected by the use of terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) and biochemical indices, alkaline phosphatase (ALP) and osteocalcin (OCN) were used to determine the effects of dexamethasone on proliferation, differentiation and apoptosis of adult osteoblasts in vitro.

RESULTSIn the adult osteoblasts obtained by collagenase-trypsin digestion, it achieved high survival, stable biochemical indices and excellent purification. Under the condition of dexamethasone 10(-8) mol/L and osteoblasts 10,000/ml, there was significant promotion of ALP and OCN secretion without cell apoptosis.

CONCLUSIONSDexamethasone has a significant effect on the proliferation and differentiation of adult osteoblasts in vitro without apoptosis, and dexamethasone at the suggested concentration can be used as positive control in drug studies for osteoporosis treatment.

Adult ; Apoptosis ; drug effects ; Cell Differentiation ; drug effects ; Cell Division ; drug effects ; Cells, Cultured ; Dexamethasone ; pharmacology ; Humans ; In Situ Nick-End Labeling ; Osteoblasts ; cytology ; drug effects

BACKGROUNDGenetic factors are important in the pathogenesis of osteoporosis, but less is known about the genetic determinants of osteoporosis treatment. We aimed to explore the association between the gene polymorphisms of key enzyme farnesyl diphosphate synthase (FDPS) in mevalonate signaling pathway of osteoclast and response to alendronate therapy in osteoporotic postmenopausal women in China.

METHODSThe study group comprised 639 postmenopausal women aged (62.2 ± 7.0) years with osteoporosis or osteopenia who had been randomly assigned to low dose group (70 mg/2 w) or standard dose group (70 mg/w) of alendronate in this 1-year study. We identified allelic variant of the FDPS gene using the polymerase chain reaction and restriction enzyme Faul. Before and after treatment, serum levels of calcium, phosphate, alkaline phosphatase (ALP), cross linked C-telopeptide of type I collagen (β-CTX) were detected. Bone mineral density (BMD) at lumbar spine and proximal femur was measured. The association was analyzed between the polymorphisms of FDPS gene and the changes of BMD, bone turnover biomarkers after the treatment.

RESULTSThe FDPS rs2297480 polymorphisms were associated with baseline BMD at femoral neck, and patients with CC genotype had significantly higher baseline femoral neck BMD ((733.6 ± 84.1) mg/cm(2)) than those with AC genotypes ((703.0 ± 86.9) mg/cm(2)) and AA genotypes ((649.8 ± 62.4) mg/cm(2)) (P < 0.01). No significant difference in BMD at lumbar spine was observed among different genotypes of FDPS. The percentage change of serum ALP level was significantly lower in patients with CC genotype (-22.9%) than that in those with AC genotype (-24.1%) and AA genotype (-29.8%) of FDPS after 12 months of alendronate treatment (P < 0.05). Neither percentage change of BMD nor β-CTX level after alendronate treatment had association with FDPS genotype.

CONCLUSIONSFDPS gene was probably a candidate gene to predict femoral neck BMD at baseline. FDPS gene alleles could predict change percentage of ALP after treatment of alendronate, but possibly had no significant relationship with the responsiveness of BMD to alendronate therapy.

Alendronate ; therapeutic use ; Asian Continental Ancestry Group ; Bone Density Conservation Agents ; therapeutic use ; Female ; Geranyltranstransferase ; genetics ; Humans ; Middle Aged ; Osteoporosis, Postmenopausal ; drug therapy ; genetics ; Polymorphism, Genetic