A bone cell population dynamics model for cor- tical bone remodeling under mechanical stimulus is devel- oped in this paper. The external experiments extracted from the literature which have not been used in the creat...A bone cell population dynamics model for cor- tical bone remodeling under mechanical stimulus is devel- oped in this paper. The external experiments extracted from the literature which have not been used in the creation of the model are used to test the validity of the model. Not only can the model compare reasonably well with these ex- perimental results such as the increase percentage of final values of bone mineral content （BMC） and bone fracture en- ergy （BFE） among different loading schemes （which proves the validity of the model）, but also predict the realtime devel- opment pattern of BMC and BFE, as well as the dynamics of osteoblasts （OBA）, osteoclasts （OCA）, nitric oxide （NO） and prostaglandin E2 （PGE2） for each loading scheme, which can hardly be monitored through experiment. In conclusion, the model is the first of its kind that is able to provide an in- sight into the quantitative mechanism of bone remodeling at cellular level by which bone cells are activated by mechan- ical stimulus in order to start resorption/formation of bone mass. More importantly, this model has laid a solid foun- dation based on which future work such as systemic control theory analysis of bone remodeling under mechanical stimu- lus can be investigated. The to-be identified control mecha- nism will help to develop effective drugs and combined non- pharmacological therapies to combat bone loss pathologies. Also this deeper understanding of how mechanical forces quantitatively interact with skeletal tissue is essential for the generation of bone tissue for tissue replacement purposes in tissue engineering.展开更多
AIM: To investigate the change of bone parameters in a new model of experimentally induced liver cirrhosis and hepatocellular carcinoma (HCC) in growing rats.METHODS: Fischer-344 rats (n = 55) were used. Carbon tetrac...AIM: To investigate the change of bone parameters in a new model of experimentally induced liver cirrhosis and hepatocellular carcinoma (HCC) in growing rats.METHODS: Fischer-344 rats (n = 55) were used. Carbon tetrachloride (CCl4), phenobarbital (PB), and a single diethylnitrosamine (DEN) injection were used. Animals were killed at wk 8 and 16. Bone mineral content, femoral length, cortical index (quotient of cortical thickness and whole diameter) and ultimate bending load (Fmax)of the femora were determined. The results in animals treated with DEN+PB+CCl4 (DPC, n = 21) were compared to those in untreated animals (UNT,n = 14) and in control group treated only with DEN+PB (DP, n = 20).RESULTS: Fatty liver and cirrhosis developed in each DPC-treated rat at wk 8 and HCC was presented at wk 16. No skeletal changes were found in this group at wk 8,but each parameter was lower (P＜0.05 for each) at wk 16 in comparison to the control group. Neither fatty liver nor cirrhosis was observed in DP-treated animals at any time point. Femoral length and Fmax values were higher (P＜0.05 for both) in DP-treated animals at wk 8 compared to the UNT controls. However, no difference was found at wk 16.CONCLUSION: Experimental liver cirrhosis and HCC are accompanied with inhibited skeletal growth, reduced bone mass, and decreased mechanical resistance in growing rats. Our results are in concordance with the data of other studies using different animal models. A novel finding is the transiently accelerated skeletal growth and bone strength after a 8-wk long phenobarbital treatment following diethylnitrosamine injection.展开更多
Background:Areal bone mineral density(aBMD)applied for osteoporosis diagnosis unavoidably results in the missingdiagnosis in patients with large bones and misdiagnosis in those with small bones.Therefore,we try to fin...Background:Areal bone mineral density(aBMD)applied for osteoporosis diagnosis unavoidably results in the missingdiagnosis in patients with large bones and misdiagnosis in those with small bones.Therefore,we try to find a new adjusted index of bone mineral content(BMC)to make up shortcomings of aBMD in osteoporosis diagnosis.Methods:In this multi-center epidemiological study,BMC and aBMD of lumbar spines(n=5510)and proximal femurs(n=4710)were measured with dual energy X-ray absorptiometry(DXA).We analyzed the correlation between the bone mass and body weight in all subjects including four age groups(<19 years,20-39 years,40-49 years,>50 years).And then the body weight was used for standardizing BMC(named wBMC)and applied for the epidemiological analysis of osteoporosis?Results:The correlation of body weight and BMC is 0.839 to 0.931 of lumbar vertebra 1-4(Li_4),and 0.71 to 0.95 of femoral neck in different age groups.When aBMD was applied for diagnosing osteoporosis,the prevalence was 7.55%,16.39%,and 25.83%in patients with a high,intermediate,and low body weight respectively.However,the prevalence was 21.8%,18.03%,and 11.64%by wBMC applied for diagnosing osteoporosis.Moreover,the prevalence of osteoporosis increased by 3.76%by wBMC with the body weight increased by 5 kg.The prevalence decreased by 1.94%when the body weight decreased by 5 kg.Conclusions:wBMC can reduce the missed diagnosis in patients with large body weight and reduce misdiagnosis in those with small body weight.Including children,wBMC may be feasible for osteoporosis diagnosis individuals at any age.展开更多
探究成年男性体适能、身体形态和骨骼健康之间的关系。选取96名成年男性作为研究对象,随机测量其身体形态(身高、体重和臀围等)和体适能(肌肉力量、柔韧性和肺功能等)。骨密度(Bone Mineral Density, BMD)和骨矿含量(Bone Mineral Conte...探究成年男性体适能、身体形态和骨骼健康之间的关系。选取96名成年男性作为研究对象,随机测量其身体形态(身高、体重和臀围等)和体适能(肌肉力量、柔韧性和肺功能等)。骨密度(Bone Mineral Density, BMD)和骨矿含量(Bone Mineral Content, BMC)使用双能X线吸收测定法进行测量。使用偏相关法来验证骨骼健康与体适能和身体形态之间的相关性,使用多元回归分析确定影响骨骼健康的主要因素。结果:矫正年龄和身体质量指数(BMI)后发现,BMD与握力、坐位体前屈、用力肺活量(Forced Vital Capacity, FVC)和1s用力呼气量(Forced Expiratory Volume In One Second, FEV1)呈显著正相关(r=-0.309~0.432,P<0.05),与俯卧体后屈呈负相关(r=-0.357,P=0.034)。BMC与臀围、握力、坐位体前屈、FVC和FEV1呈显著正相关(r=-0.359~0.537,P<0.05),与俯卧体后屈呈负相关(r=-0.333,P=0.034)。握力、俯卧体后屈和FEV1是预测BMD的主要因素(B=-0.004~0.045,P<0.05)。握力、俯卧体前屈、FVC、臀围和坐位体前屈是预测BMC的主要因素(B=-14.391~178.566,P<0.05)。结论:骨骼健康与身体形态和体适能具有显着相关性。预测骨骼健康的体适能指标集中在肌肉力量、柔韧性和肺功能。身体形态指标臀围可以预测BMC。展开更多
文摘A bone cell population dynamics model for cor- tical bone remodeling under mechanical stimulus is devel- oped in this paper. The external experiments extracted from the literature which have not been used in the creation of the model are used to test the validity of the model. Not only can the model compare reasonably well with these ex- perimental results such as the increase percentage of final values of bone mineral content （BMC） and bone fracture en- ergy （BFE） among different loading schemes （which proves the validity of the model）, but also predict the realtime devel- opment pattern of BMC and BFE, as well as the dynamics of osteoblasts （OBA）, osteoclasts （OCA）, nitric oxide （NO） and prostaglandin E2 （PGE2） for each loading scheme, which can hardly be monitored through experiment. In conclusion, the model is the first of its kind that is able to provide an in- sight into the quantitative mechanism of bone remodeling at cellular level by which bone cells are activated by mechan- ical stimulus in order to start resorption/formation of bone mass. More importantly, this model has laid a solid foun- dation based on which future work such as systemic control theory analysis of bone remodeling under mechanical stimu- lus can be investigated. The to-be identified control mecha- nism will help to develop effective drugs and combined non- pharmacological therapies to combat bone loss pathologies. Also this deeper understanding of how mechanical forces quantitatively interact with skeletal tissue is essential for the generation of bone tissue for tissue replacement purposes in tissue engineering.
基金Supported by The Medical Research Council of Hungary, ETT 226/2003, 232/2003The Hungarian Scientific Research Fund, OTKA T038067, T038154
文摘AIM: To investigate the change of bone parameters in a new model of experimentally induced liver cirrhosis and hepatocellular carcinoma (HCC) in growing rats.METHODS: Fischer-344 rats (n = 55) were used. Carbon tetrachloride (CCl4), phenobarbital (PB), and a single diethylnitrosamine (DEN) injection were used. Animals were killed at wk 8 and 16. Bone mineral content, femoral length, cortical index (quotient of cortical thickness and whole diameter) and ultimate bending load (Fmax)of the femora were determined. The results in animals treated with DEN+PB+CCl4 (DPC, n = 21) were compared to those in untreated animals (UNT,n = 14) and in control group treated only with DEN+PB (DP, n = 20).RESULTS: Fatty liver and cirrhosis developed in each DPC-treated rat at wk 8 and HCC was presented at wk 16. No skeletal changes were found in this group at wk 8,but each parameter was lower (P＜0.05 for each) at wk 16 in comparison to the control group. Neither fatty liver nor cirrhosis was observed in DP-treated animals at any time point. Femoral length and Fmax values were higher (P＜0.05 for both) in DP-treated animals at wk 8 compared to the UNT controls. However, no difference was found at wk 16.CONCLUSION: Experimental liver cirrhosis and HCC are accompanied with inhibited skeletal growth, reduced bone mass, and decreased mechanical resistance in growing rats. Our results are in concordance with the data of other studies using different animal models. A novel finding is the transiently accelerated skeletal growth and bone strength after a 8-wk long phenobarbital treatment following diethylnitrosamine injection.
文摘Background:Areal bone mineral density(aBMD)applied for osteoporosis diagnosis unavoidably results in the missingdiagnosis in patients with large bones and misdiagnosis in those with small bones.Therefore,we try to find a new adjusted index of bone mineral content(BMC)to make up shortcomings of aBMD in osteoporosis diagnosis.Methods:In this multi-center epidemiological study,BMC and aBMD of lumbar spines(n=5510)and proximal femurs(n=4710)were measured with dual energy X-ray absorptiometry(DXA).We analyzed the correlation between the bone mass and body weight in all subjects including four age groups(<19 years,20-39 years,40-49 years,>50 years).And then the body weight was used for standardizing BMC(named wBMC)and applied for the epidemiological analysis of osteoporosis?Results:The correlation of body weight and BMC is 0.839 to 0.931 of lumbar vertebra 1-4(Li_4),and 0.71 to 0.95 of femoral neck in different age groups.When aBMD was applied for diagnosing osteoporosis,the prevalence was 7.55%,16.39%,and 25.83%in patients with a high,intermediate,and low body weight respectively.However,the prevalence was 21.8%,18.03%,and 11.64%by wBMC applied for diagnosing osteoporosis.Moreover,the prevalence of osteoporosis increased by 3.76%by wBMC with the body weight increased by 5 kg.The prevalence decreased by 1.94%when the body weight decreased by 5 kg.Conclusions:wBMC can reduce the missed diagnosis in patients with large body weight and reduce misdiagnosis in those with small body weight.Including children,wBMC may be feasible for osteoporosis diagnosis individuals at any age.
文摘探究成年男性体适能、身体形态和骨骼健康之间的关系。选取96名成年男性作为研究对象,随机测量其身体形态(身高、体重和臀围等)和体适能(肌肉力量、柔韧性和肺功能等)。骨密度(Bone Mineral Density, BMD)和骨矿含量(Bone Mineral Content, BMC)使用双能X线吸收测定法进行测量。使用偏相关法来验证骨骼健康与体适能和身体形态之间的相关性,使用多元回归分析确定影响骨骼健康的主要因素。结果:矫正年龄和身体质量指数(BMI)后发现,BMD与握力、坐位体前屈、用力肺活量(Forced Vital Capacity, FVC)和1s用力呼气量(Forced Expiratory Volume In One Second, FEV1)呈显著正相关(r=-0.309~0.432,P<0.05),与俯卧体后屈呈负相关(r=-0.357,P=0.034)。BMC与臀围、握力、坐位体前屈、FVC和FEV1呈显著正相关(r=-0.359~0.537,P<0.05),与俯卧体后屈呈负相关(r=-0.333,P=0.034)。握力、俯卧体后屈和FEV1是预测BMD的主要因素(B=-0.004~0.045,P<0.05)。握力、俯卧体前屈、FVC、臀围和坐位体前屈是预测BMC的主要因素(B=-14.391~178.566,P<0.05)。结论:骨骼健康与身体形态和体适能具有显着相关性。预测骨骼健康的体适能指标集中在肌肉力量、柔韧性和肺功能。身体形态指标臀围可以预测BMC。
