OBJECTIVE: To explore the effect of methylprednisolone on bone mass, microarchitecture and microdamage in cortical bone of ulna in rats. METHODS: Twenty female Sprague-Dawley rats (3.5 months old) were randomly assigned to two groups: a treatment group and a control group (n=10 per group). The treatment group was subcutaneously injected with methylprednisolone 3.5 mg/(kg.d) while the control group was subcutaneously injected with same volume of vehicle (saline). Rats were sacrificed at 9 weeks after the treatments. Before the sacrifice, the body weight and total bone mineral density (BMD) were measured. The right forelimb was separated through humeral shoulder and then single axial fatigue loading was performed on the right ulna. After fatigue load, the middle ulna section was bulkstained in basic fuchsin. Bone histomorphometry and microdamage analysis were performed on the middle ulna section. RESULTS: Compared with the control group, the body weight, total bone BMD and ulnas BMD in the treatment group were decreased by 15%, 6.4% and 4.3% respectively (all P<0.05); the ulna inner perimeter and marrow area in the treatment group were increased by 23.3% and 32%, respectively (both P<0.05), while the outer perimeter were decreased by 3.1% (P>0.05). There was no significant difference in the cortical and total area between the 2 groups (both P>0.05). The number of microcrack, microcrack density and microcrack surface density in the treatment group were increased by 43%, 48% and 50%, respectively, compared with those in the control group (all P<0.05), but there was no significant difference in the mean length of microcrack between the 2 groups (P>0.05). CONCLUSION Methylprednisolone can significantly induce the bone loss and the deterioration of microarchitecture and microdamage in ulna of rats.
Animals ; Bone Density ; drug effects ; Female ; Methylprednisolone ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Ulna ; drug effects ; pathology

AIMTo investigate the effects of genistein on bone mineralization in ovariectomized rats.

METHODSForty-seven Wistar rats were randomly allocated into six groups: sham-operated (sham), ovariectomized (ovx), ovariectomized supplied with diethyl stilbestrol (E, 20 microg x kg bw(-1) x d(-1)) or genistein (25, 50, 100 mg x kg bw(-1) x d(-1)). After the rats had been fed for three months, analysis of the bone mineral density, parameters related to mineralization, bone content of Ca, P, Mg, Mn and Zn and serum concentration of parathyroid calcitonin and estrogen was performed.

RESULTSBone mineral density, bone Ca, P, Zn and Mg content and serum estrogen concentration in ovariectomized rats were significantly decreased, but mean osteoid width increased, mineralization lag time and osteoid maturation period prolonged compared with sham animals. After three months supplementation to ovariectomized rats, bone Ca, P and Mg content increased, mean osteoid width decreased, mineralization lag time and osteoid maturation period shortened compared with ovariectomized animals.

CONCLUSIONGenistein promotes bone mineralization by increasing bone Ca, P, Mg and adjusting serum calcitonin to prevent osteoporosis.

Animals ; Bone Density ; drug effects ; Bone Resorption ; Calcification, Physiologic ; drug effects ; Female ; Genistein ; pharmacology ; Ovariectomy ; Rats ; Rats, Wistar

OBJECTIVETo evaluate the influence and safety of denosumab on bone mineral density (BMD) of lumbar spine in women with low bone mass.

METHODSThe clinical literatures concerning denosumab for the treatment of osteopenia or osteoporosis in women were searched from Medline, Embase, Cochrane Central Register of Controlled Trials, Wanfang database, China National Knowledge Infrastructure database, Chinese Biomedical Database. Randomized controlled trials (RCT) were selected by the inclusive and exclusive criteria. The jadad scale was used in the quality assessment of included studies. Meta-analysis of valid data picked from included studies was performed by RevMan 5.0.24 software.

RESULTS5 RCT were included in this meta-analysis. The results of meta-analysis using the fixed effects model showed that, the increase level of lumbar BMD after 12 month was 5.45% (95% CI, 5.05%~5.84%) higher in denosumab group than in placebo control group (P<0.00001). The serious adverse event, serious infection event and pack pain occurred during the followed-up were analysed using fixed effects model. The results showed no significant difference between two groups.

CONCLUSIONCompared with placebo control group, denosumab can significant increase the BMD of lumbar spine, and the safety of two groups is similar.

Antibodies, Monoclonal, Humanized ; adverse effects ; pharmacology ; Bone Density ; drug effects ; Bone Density Conservation Agents ; adverse effects ; pharmacology ; Denosumab ; Female ; Humans ; Lumbar Vertebrae ; Randomized Controlled Trials as Topic

OBJECTIVETo investigate the effect of androgen on microstructure and mechanics nature of bone in orchiechtomied (ORX) male rats and reveal its mechanism by using the Micro CT analysis, bone biomechanics test, bone histomorphometric parameter test, and total body bone mineral density (BMD) measured by dual-energy X-ray absorptiomery (DXA).

METHODSThirty 12-month-old male Wister rats were randomly divided into three groups including ORX, sham-operated (Sham) and androgen (AD) group, ten rats in every group. Total body BMD was measured by DXA. Femurs and vertebrae were then harvested at the 12 th week after ORX for micro-computed tomography (Micro CT), histology and biomechanical were tested.

RESULTSThe administration of testosterone may reverse the decreasing BMD of total body and may prevent the decreasing weight. The biomechanical values of Maximum load, Enery, Maximum stress, Elastic Modulus of AD group significantly enhanced compared with ORX group (P < 0.05). The results of histomorphometric parameters showed that cancellous bone volume, osteoblast-osteoid interface, linear extent of bone formation, mineralizing surfaces, mineral apposition rate increased in the therapy group.

CONCLUSIONAndrogen can accelerate cancellous bone formation and bone turnover, improve bone microstructure and enhance bone intensity and BMD.

Androgens ; pharmacology ; Animals ; Biomechanical Phenomena ; Body Weight ; drug effects ; Bone Density ; drug effects ; Bone and Bones ; drug effects ; ultrastructure ; Imaging, Three-Dimensional ; Male ; Orchiectomy ; Osteoporosis ; etiology ; Rats ; Rats, Wistar

AIMTo investigate the effects of testosterone on bone mineral density (BMD), plasma levels of sex hormone and calcium, phosphorus, and parathyroid hormone (PTH).

METHODSThirty 10 week old male rabbits were randomized into sham operated (SH), orchiectomized (ORX) and testosterone undecanoate replacement (TU) group. TU rabbits were injected with testosterone undecanoate in 10 orchiectomized rabbits and the remaining SH and ORX rabbits, vehicle only 20 weeks after initiation of the experiment, bone mineral density was measured with dual-energy X-ray bone densitometer. Blood was collected for determination of serum levels of total testosterone, estradiol, calcium, magnesium, phosphorus and alkaline phosphatase (AKP).

RESULTSThe serum levels of total testosterone and femoral neck BMD decreased, serum levels of calcium, magnesium and AKP increased significantly in ORX rabbits, testosterone improved femoral neck BMD and decreased serum levels of calcium, magnesium and AKP significantly in TU rabbits.

CONCLUSIONThe results of the present study indicate that ORX decrease serum testosterone and BMD, exogenous testosterone treatment can prevent osteoporosis in ORX rabbits.

Animals ; Bone Density ; drug effects ; Calcium ; blood ; Male ; Orchiectomy ; Phosphorus ; blood ; Rabbits ; Testosterone ; pharmacology

OBJECTIVETo investigate the effects of occupational lead exposure on lumbar vertebral fracture in exposed male workers.

METHODSOne hundred and fifty-two lead-exposed male workers in a storage battery plant in Shanghai were selected as the study population. The blood lead (BPb) and the urinary lead (UPb) were measured by graphite-furnace atomic absorption spectrometry (GF-AAS). Bone mineral density (BMD) was measured by the monophoton absorptiometry(SPA-4) and Z score was determined. Anteroposterior and lateral lumbar spinal X-ray films were taken to determine lumbar vertebral fracture.

RESULTSFor the occupationally lead-exposed workers, geometric mean of BPb was 0.85 (0.33 approximately 1.90) micromol/L, geometric mean of UPb was 4.84 (0.46 approximately 21.31) microg/g Cr, and the prevalence of lumbar vertebral fracture was 19.7%. The prevalence of lumbar vertebral fracture would increase with the increase of age and work year, but with no significantly statistical difference (P > 0.05). The bone mineral density (BMD) would decrease with the increase of BPb and UPb (P < 0.05). The prevalence of lumbar vertebral fracture would increase significantly with the increase of the lead exposure (P < 0.05) with the linear correlation (P < 0.05). The prevalence of lumbar vertebral fracture would increase significantly with the decrease of the bone mass (P < 0.01) with the linear correlation (P < 0.01).

CONCLUSIONThe occupational exposure to lead could cause the decrease of the bone mineral density and the increase of the prevalence of lumbar vertebral fracture. The development of lumbar vertebral fracture is associated with the decrease of bone mass.

Bone Density ; drug effects ; China ; Humans ; Male ; Occupational Exposure ; Spinal Fractures ; X-Ray Film

BACKGROUNDDepot medroxyprogesterone acetate (DMPA) as a hormonal contraceptive is highly effective and widely used, but it may reduce bone mineral density (BMD) and increase the risk of osteoporosis. We compared BMD between users of intramuscular DMPA and nonhormonal subjects.

METHODSThe study included 102 women aged between 16 and 18 years using DMPA for 24 months and 97 women aged between 16 and 18 years using nonhormonal contraception as nonusers control group. BMD of the lumbar spine and femoral neck was measured every 12 months for 24 months using dual-energy X-ray absorptiometry, comparing mean BMD changes in DMPA users and nonusers.

RESULTSThere were no significant differences between groups at baseline in age, gynecologic age, body mass index (BMI), lumbar spine BMD and femoral neck BMD, etc. At 24 months of DMPA treatment, the mean percentage change from baseline in lumbar spine and femoral neck BMD values had decreased by 1.88% and 2.32%, respectively. The mean lumbar spine and femoral neck BMD in DMPA group at 24 months were not significantly different compared to baseline (P = 0.212 and P = 0.106, respectively). In comparison, in nonhormonal control group, there was a trend toward increasing BMD. At 24 months of observation, the mean percentage change from baseline in lumbar spine and femoral neck BMD had increased by 2.08% and 1.46%, respectively. There were no significant difference compared to baseline (P = 0.160 and P = 0.288, respectively). Mean BMD at the spine and femoral neck did not differ significantly between DMPA users and nonusers over 12-month, but the BMD values at both anatomical sites were significantly lower in DMPA users compared with nonusers after 24-month treatment (P = 0.009 and P = 0.009, respectively).

CONCLUSIONThe evidence of our study suggested that the use of DMPA for short-term (≤12-month) has no significant effects on BMD at spine and femoral neck, but long-term exposure to DMPA may prevent the bone mass accrual in adolescents.

Adolescent ; Bone Density ; drug effects ; Contraceptive Agents, Female ; pharmacology ; Female ; Humans ; Medroxyprogesterone Acetate ; pharmacology

BACKGROUNDThe association of long-term bisphosphonate treatment for osteoporosis and related safety problems such as atypical fractures were not clearly defined. This study was to evaluate the structural, densitometric and biomechanical properties of the prolonged bisphosphonate-loaded bones.

METHODSBone mineral density (BMD) at hip and femoral midshaft, bone cross-sectional area, moment of inertia of both femurs, bone formation and resorption biochemical markers were compared between 28 elderly with at least 4 years of bisphosphonate treatment from 2002 through 2006 and age-matched group of 37 elderly.

RESULTSThe total hip BMD and t-score were found not different between two groups. However, bisphosphonate treated patients were found to have significantly lower bone mineral content in the femoral shaft (P < 0.05); morphological study showed lower cross-sectional area in subtrochanteric and mid-diaphyseal region and thus significantly lower moment of inertia (P < 0.01). High resolution-peripheral quantitative computed tomography showed significantly decreased trabecular density, bone volume ratio, trabecular number but increased trabecular spacing in tibia and distal radius. Finite element analysis further confirmed significantly lower stiffness and failure load in tibia. Biochemical studies also showed lower bone resorption and severely suppressed bone formation activity (P < 0.001).

CONCLUSIONSThe unchanged total hip BMD between two groups confirmed the beneficial effects of bisphosphonate on trabecular bone, thus preventing osteoporotic fractures at large in previous studies. However, the inferior structural, densitometric and biomechanical properties at cortical bones, especially femur midshaft, need a special attention to look into the association between long-term bisphosphonate intake and the occurrence of stress fractures. When patients taking bisphosphonate complain of proximal thigh pain or discomfort, plain X-ray film can be the first line screening. All patients prescribed with bisphosphonate should be informed of such a complication though we must stress its rarity.

Aged ; Aged, 80 and over ; Biomechanical Phenomena ; Bone Density ; drug effects ; Bone Density Conservation Agents ; adverse effects ; Bone Remodeling ; drug effects ; Densitometry ; Diphosphonates ; adverse effects ; Female ; Finite Element Analysis ; Humans ; Male ; Middle Aged ; RANK Ligand ; blood

Zebrafish was selected as model animal, and glucocorticoid dexamethasone was used as a model compound to establish a rapid and high efficient osteopenia model. Zebrafish larvae at 4 days post fertilization (dpf) were exposed to a serial concentrations of dexamethasone solutions, and 0.5% DMSO was selected as the vehicle control group. All groups were incubated in 24-well plates (28.5 degrees C) until 9 dpf. In addition, effects of 10 micromol x L(-1) dexamethasone on preventing against osteopenia induced by etidronate disodium were also investigated. Zebrafish bones at 9 dpf were stained with alizarin red. Quantitative analysis of the stained area was performed by microscopic inspection and digital imaging methods to reflect the amount of bone mineralization. Results showed that dexamethasone group at 2.5, 10 and 25 micromol x L(-1) can decrease the staining area and the staining optical density values of zebrafish head bones when compared with the vehicle control group (0.5% DMSO), which suggested that dexamethasone can significantly reduce the zebrafish mineralized bone and the bone mineral density. Results also showed that 15 and 30 microg x mL(-1) etidronate disodium can increase the mineralized matrix of zebrafish head bone and prevent against osteopenia induced by dexamethasone. In conclusion, the study indicated that zebrafish can be an idea osteopenia model induced by dexamethasone.
Animals ; Bone Density ; drug effects ; Bone Density Conservation Agents ; pharmacology ; therapeutic use ; Bone Diseases, Metabolic ; chemically induced ; prevention & control ; Calcification, Physiologic ; drug effects ; Dexamethasone ; toxicity ; Disease Models, Animal ; Etidronic Acid ; pharmacology ; therapeutic use ; Larva ; drug effects ; growth & development ; Zebrafish

This study was aimed to detect the effects of alcohol on bone metabolism and biomechanical property of growing mice. Thirty KM mice were randomly divided into 3 groups, namely basal control group (mice were killed at the beginning), normal control group (with distilled water given by gastrogavage), and 50% (V/V) alcohol group (with alcohol given by gastrogavage at the dose of 4 g x kg(-1) x d(-1) for 60 days). All mice were killed and their proximal tibia and tibial diaphysis were processed by undecalcified sections and measured by bone histomorphometry. The biomechanical properties of lumbar vertebra and femur were tested. Compared with normal control, the index of trabecular bone area (% Tb. Ar) of proximal tibial metaphysis (PTM) and the static parameter of cortical bone( Ct. Ar) both decreased obviously (P < 0.05) in alcohol group. Bone formation rate (BFR/TV) of trabecular bone and cortical bone dropped also (P < 0.05). The maximal resistibility of lumbar vertebra and structural mechanical strength of proximal femoral neck both declined significantly (P < 0.01) in alcohol group. Low dose of alcohol inhibited the bone formation rate of growing mice , thus leading to a disorder of bone metabolism and a decrease in biomechanical quality.
Animals ; Biomechanical Phenomena ; Bone Density ; drug effects ; Bone and Bones ; drug effects ; metabolism ; Ethanol ; adverse effects ; pharmacology ; Female ; Male ; Mice ; Random Allocation