去卵巢大鼠骨基质明胶修复骨缺损骨痂的矿物质元素分析

应用等离子体发射光谱仪测定了去卵巢水平下骨基质明胶修复大鼠颅骨骨缺损新生骨痂的矿物质元素含量。将28只雌性SD大鼠随机分为2组。去卵巢组切除双侧卵巢，伪手术对照组保留卵巢。术后4周在颅骨上制备骨缺损并同期植入骨基质明胶。8周后，测定新生骨痂的矿物质元素含量。结果显示，去卵巢大鼠新生骨痂的S、Ca、P、Zn、Fe和Cu含量较伪手术组显著降低。实验表明雌激素水平影响骨基质明胶修复骨缺损骨痂的矿物质元素含量。     

Raman spectroscopic of osteoporosis model in mouse tibia in vivo

In this work, we correlate Raman spectroscopy in vivo which is performed in healthy bone tibia, 3-month-old mice with osteoporotic bone, within two groups: OVX (ovariectomized) and sham (lumbar access, no ovariectomy group control). Laser beam was applied directly in a punch of skin in the distal medial part of tibia. To access bone quality, we calculate mineral/matrix ratio, relative lipid and proteoglycan content as well as the crystallinity using normalized spectrum within the integrated area method. The variables obtained for bone quality were statistically verify by ANOVA and tested for normality, where differences were considered to be significant for P < 0.05. In osteoporotic bone (OVX) we found a decreasing ratio between mineral to matrix and relative proteoglycan content, followed by a relative increasing lipid content when comparing with healthy bone (Sham) with statistical significance. The crystallinity showed higher value for OVX group but without statistical significance. Our Confocal Raman Spectroscopy provides a well-controlled environment to differentiate osteoporotic bone from healthy bone by decreasing calcium and glycosaminoglycans and increasing the amount of lipids in the cortical tibia of the mouse in vivo.     

Skeletal calcium/phosphorus ratio measuring techniques by neutron activation and X-ray absorptiometry

Summary An approach to the problem of bone disorders is the measurement of the skeletons’ static and dynamic strength, an estimate of the bone mineral density. A decrease in the bone density may be due to the decrease in either Ca or P content, or to dissimilar decreases in both. Consequently, the determination of the Ca/P ratio may provide a sensitive measure of bone mineral changes and may add to our understanding of the changes occurring in bone diseases. This paper reviews the instrumental neutron activation analysis (INAA) and X-ray absorptiometry techniques, which have been developed for the in vitro or in vivo assessment of the Ca, P content and the Ca/P ratio in bones, respectively. Their main aspects and results are presented, regarding the referred values.     

鸡铝氟联合作用--铁与骨矿化和矿物元素的关系

为探讨铝氟联合作用时铁与矿物代谢的关系,在鸡铝氟病及铝危害模型基础上对全血铁和骨铁用 AAS法进行了检测.结果表明,性成熟前各实验组全血铁均升高,但以加氟组更为明显;性成熟后饲料加入氟化物的 3个组全血铁仍高于对照,未加的另3个组则低于或接近对照组.骨铁含量均有所下降.饲氟、骨氟、骨铝与全血铁有明显正相关(P＜0.2)或显著正相关(P＜0.05),与骨铁有明显负相关,差异均有显著或非常明显(P＜0.1) 意义.全血铁与全血钙、镁、磷,骨灰化率、骨矿含量、平均骨壁厚度、骨矿沉积率均呈显著正相关.骨铁与骨钙、镁呈显著或明显负相关,与成骨细胞指数、破骨细胞指数、类骨质体积呈明显或非常显著(P＜0.01)负相关,与骨单位吸收周期呈明显正相关.全血铁与骨铁呈明显负相关.提示,全血与骨骼铁代谢是能分离又相对应的体系,可能有相互平衡、调节和补偿作用.铁不仅是血红蛋白的必需成分,还与骨矿化和骨细胞及矿物元素有密切关系.     

A comparison of sodium amounts in compact bone,red marrow and yellow marrow sections as determined by instrumental neutron activation analysis

Sodium was determined by the use of instrumental neutron activation analysis in sections of compact bone, red marrow and yellow marrow to check possible effects of shoft tissues in the bone when determining the Na/Ca ratio in sections of the undecalcified bone tissue. The results indicated that this ratio actually reflects the sodium content in the bone mineral, the contribution from the soft tissues being two orders of magnitude lower.     

氟化物对幼年大鼠骨矿物质和血微量元素的影响及其相关性研究

为探讨氟化钠对幼年大鼠血清4种微量元素和骨矿物质含量的影响,以及大鼠骨矿物质和血清微量元素的相关性,将80只2月龄SPF级SO大鼠,雌雄各半,随机分成8组：对照（幼年CS、成年AS）组和用药组（幼年高氟组CHS、幼年低氟组CLS、成年高氟组AHS、成年低氟组ALS、幼年长期高氟组HS、幼年长期低氟组15）。对照组灌胃生理盐水,用药组分别按相应时间给予不同剂量的NaF灌胃,测定了大鼠尺骨和血清中的Ca、P、Fe、Zn含量。结果表明,（1）血清微量元素：①与cs组相比,CHS组和CLS组的磷（P）分别增加100．0％和193．8％（P〈0．05）。②与AS组相比,HS组的Ca、Zn分别下降了20．5％和40．0％,而P则增加了74．0％（P〈0．05）;Ls组的Zn下降了33．3％（P〈0．05）。与HS组比较,CHS组的Ca增加22．3％。③与LS组比较,CLS组的P和Zn明显增加49．2％和28．5％（P〈0．05）。（2）骨矿物质：①与As组相比,HS组的Ca分别下降了23．9％（P〈0．05）,Zn则增加了36．1％（P〈0．05）。②与HS组相比,CHS组的Ca和Fe分别增加了42．3％和36．05％,Zn下降了38．6％（P〈0．05）。（3）骨矿物质和血清微量元素的相关性：骨Ca和血Ca、骨P和血P、骨Zn和血Zn、骨Fe和血Fe的相关系数分别为0．435、0．347、0．136和0．059（P〉0．05）。提示长期使用氟化钠,可以导致幼年大鼠血中微量元素代谢紊乱,骨矿物含量降低,但未确定大鼠骨矿物含量和血微量元素具有相关性。     

Micro-CT参数对骨质疏松性椎体压缩性骨折术后复发的预测价值

本研究探讨Micro-CT参数对骨质疏松性椎体压缩性骨折(OVCF)患者术后复发的预测价值。选取OVCF患者127例,根据术后6个月骨折复发情况分为复发组(n=41)与未复发组(n=86)。患者均接受Micro-CT检查,对比两组Micro-CT参数,即骨体积分数(BV/TV)、骨小梁厚度(Tb.Th)、骨小梁间隙(Tb.Sp)、结构模型指数(SMI),以及骨密度(BMD)、骨矿含量(BMC),分析各参数与BMD、BMC及术后复发相关性,并评价各参数对术后复发的预测价值。结果显示,复发组骨体积分数(BV/TV)、骨小梁厚度(Tb.Th)低于未复发组,骨小梁间隙(Tb.Sp)、结构模型指数(SMI)高于未复发组(P<0.05);BV/TV、Tb.Th与骨密度(BMD)、骨矿含量(BMC)呈正相关,Tb.Sp、SMI与BMD、BMC呈负相关(P<0.05);将年龄、BMD、BMC等其他因素控制后,BV/TV、Tb.Sp、Tb.Th、SMI与OVCF术后骨折复发显著相关(P<0.05);BV/TV、Tb.Sp、Tb.Th、SMI联合预测OVCF术后骨折复发的曲线下面积(AUC)最大,为0.888(P<0.05)。提示Micro-CT参数在OVCF患者中呈异常表达,采用Micro-CT检查可为临床预测OVCF术后骨折复发提供科学指导。     

藏药牦牛肝提取物中矿物质元素特征及意义

采用220FS原子吸收光谱仪测定了传统藏药牦牛肝提取物中的K、Na、Ca、Mg、Fe、Cu、Zn、Mn等8种矿物质元素含量.结果显示,藏药牦牛肝提取物中含有丰富的矿物质元素,对儿童和青少年骨骼的生长发育,中老年骨质疏松症预防有着极为重要的营养学和治疗意义,开发前景广阔.     

On the distribution of trace elements in human skeletons

Instrumental neutron activation analysis and flameless atomic absorption spectrometry have been used to study the occurence and distribution with a maximum of 25 elements in multiple sites of a skeleton and in the iliac crest of 69 ancient human skeletons. To study the distribution of trace elements between the different bone fractions the material of each sampling site was chemically treated to separate the collagen and the mineral from one another. Losses or contamination during the extraction procedure have been controled in detail by balance calculations. The elements can be subdivided into several groups due to the balance calculation and their association with the mineral. The analysis of the skeleton showed that the trace elements are distributed in varying degrees within a bone and throughout the skeleton their variation seems to be related to functional and structural conditions of the sampling site. The element content was observed to be higher at epiphyseal areas of long bones than in the shaft and higher in trabecular than in cortical bones. It was found that the element content of a single bone sample depends largely on the mass ratio spongiosa/compacta at the sampling site. By investigating an ancient population group, information about the “natural levels” and biological variation of trace elements was obtained. The results for F, Pb, Sr, and Zn in particular suggest that these elements could be useful in the study of health problems in man which involves the bone tissue.     

How well does dual photon absorptiometry predict osteoporosis? A comparison between neutron activation analysis and DEXA

The accuracy of dual energy X-ray absorptiometry (DEXA) for measurement of bone mass carried out by quantitative digital radiography (Hologic Inc.) was compared to results with neutron activation analysis (NAA) on 106 subjects. The accuracy with DEXA was further investigated by measurements on aluminium samples of known composition. DEXA measured 4 lumbar vertebrae by spine scan. The central third of the skeleton also was measured by whole body scan to obtain data on the same large part of the skeleton as measured by NAA. Results suggested that DEXA spine scans were more reliable than whole body scans. In addition, the measurement of total mineral content (BMC) was more reliable than the normalization of BMC to bone surface area (BMC/Area) or bone mineral density (BDM). Since the proportion of bone below detection would increase with development of osteoporosis, with osteoporosis the BMC would be increasingly underestimated, but to only a small extent, while the BMD would be more significantly overestimated.     

Comparison of the determination of body calcium by in-vivo neutron activation analysis (IVNAA) and dual energy X-ray absorptiometry (DEXA)

The measurement of total body calcium is an important tool in the diagnosis and treatment of many diseases associated with bone. This measurement is done by IVNAA or DEXA. A knowledge of normal bone mineral mass for a given person, is necessary to determine whether or not a measured quantity is normal or low. The factors that determine bone mineral mass in a person are not clearly known. IVNAA indicates that bone mineral mass is a function of height but not the age whereas the reverse is indicated by DEXA. In this work, we have measured the bone mineral mass of over 200 normal volunteers by IVNAA and DEXA and have developed a methametical model for DEXA (for lumbar spine and femoral neck) as a function of height, age, weight and years after menopause. In determining the bone mineral mass, height is the predominant factor under 20 years of age and age appers to be the dominant factor for over 20 years. The equation derived is useful in calculating the normal bone mineral mass in a patient against which the measured value can be compared.     

Lycopene effects on serum mineral elements and bone strength in rats

This study investigated the beneficial effect of lycopene on bone biomarkers in ovariectomized (OVX) rats. Female Wistar rats were either sham operated or surgically ovariectomized and then fed with lycopene for 8 weeks. Serum Ca, P, alkaline phosphatase (ALP), interleukin 6 (IL-6) and bone gla protein (BGP) concentration was significantly higher in the untreated OVX group compared with that of the sham group, whereas serum estrogen levels were lower. Bone mineral density (BMD), BMD/wt, bone mineral content (BMC), BMC/wt values, maximum load, stiffness, energy and maximum stress were significantly lower in the untreated OVX group compared with that of the sham group. Administration of lycopene (20, 30 and 40 mg/kg b.w.) for 8 weeks significantly decreased serum Ca, P, ALP, and IL-6 concentration, and enhanced serum estrogen level, BMD, BMD/wt, BMC, BMC/wt values, maximum load, stiffness, energy and maximum stress in lycopene-treated OVX groups. In conclusion, the consumption of lycopene may have the most protective effect on bone in OVX rats.     

Raman spectroscopy monitors adverse bone sequelae of cancer radiotherapy

Raman spectroscopy provides information on bone chemical composition and structure via widely used metrics including mineral to matrix ratio, mineral crystallinity and carbonate content, collagen crosslinking ratio and depolarization ratios. These metrics are correlated with bone material properties, such as hardness, plasticity and Young''s modulus. We review application of Raman spectroscopy to two important irradiated animalmodels: the mouse tibia, amodel for damage to cortical bone sites including the rib (breast cancer) and to healthy tissue adjacent to extremity sarcomas, and the rat mandible, a model for radiation damage in head and neck cancer radiotherapy. Longitudinal studies of irradiated mouse tibia demonstrate that radiation-induced matrix abnormalities can persist even 26 weeks postradiation. Polarized Raman spectroscopy shows formation of more ordered orientation of both mineral and collagen. At 8 weeks post-radiation, irradiated rat hemimandible exhibits transient hypermineralization, increased collagen cross-linking and decreased depolarization ratios of mineral and collagen. A standard radioprotectant, amifostine, mitigates rat mandible radiation damage, with none remaining detectable 18 weeks post-radiation. Already a powerful tool to monitor radiation damage, Raman spectroscopy may be important in development of new radiotherapy protocols and radioprotective agents. Further in vivo studies of radiation effects on the rodent models are underway, as are development of methodologies for eventual use in human subjects.     

Orientation of mineral crystals by collagen fibers during in vivo bone engineering: An X-ray diffraction imaging study

The mechanism of mineralized bone matrix deposition was investigated taking advantage of a tissue engineering approach in which bone tissue is formed when porous ceramic scaffold is loaded with bone marrow stromal cells and implanted in vivo. The aim of our study is to point out the interaction between the newly formed mineral crystals and the scaffold imposing the three-dimensional desired architecture to the growing bone. High spatial resolution Small Angle X-ray Scattering measurements obtained using synchrotron radiation and X-ray waveguide as optical element allowed a local structural study at the bone–scaffold interface. Using an original methodology for data analysis, we obtained a two-dimensional microscopic map of the mineralization degree, the collagen presence and the mineral orientation degree around the scaffold pore.     

Solid state NMR investigation of intact human bone quality: balancing issues and insight into the structure at the organic-mineral interface

Age-related bone fragility fractures present a significant problem for public health. Measures of bone quality are increasingly recognized to complement the conventional bone mineral density (BMD) based assessment of fracture risk. The ability to probe and understand bone quality at the molecular level is desirable in order to unravel how the structure of organic matrix and its association with mineral contribute to the overall mechanical properties. The (13)C{(31)P} REDOR MAS NMR (Rotational Echo Double Resonance Magic Angle Spinning Nuclear Magnetic Resonance) technique is uniquely suited for the study of the structure of the organic-mineral interface in bone. For the first time, we have applied it successfully to analyze the structure of intact (non-powdered) human cortical bone samples, from young healthy and old osteoporotic donors. Loading problems associated with the rapid rotation of intact bone were solved using a Finite Element Analysis (FEA) approach, and a method allowing osteoporotic samples to be balanced and spun reproducibly is described. REDOR NMR parameters were set to allow insight into the arrangement of the amino acids at the mineral interface to be accessed, and SVD (Singular Value Decomposition) was applied to enhance the signal to noise ratio and enable a better analysis of the data. From the REDOR data, it was found that carbon atoms belonging to citrate/glucosaminoglycans (GAGs) are closest to the mineral surface regardless of age or site. In contrast, the arrangement of the collagen backbone at the interface varied with site and age. The relative proximity of two of the main amino acids in bone matrix proteins, hydroxyproline and alanine, with respect to the mineral phase was analyzed in more detail, and discussed in view of glycation measurements which were carried out on the tissues. Overall, this work shows that the (13)C{(31)P} REDOR NMR approach could be used as a complementary technique to assess a novel aspect of bone quality, the organic-mineral interface structure.     

Effect of ashing on the extractability of the radiotracer22Na from bone mineral

A very slow extraction of radiosodium with water from the ashed rabbit bone was observed (T=375 h). Thus, the ashing procedure does not facilitate the sodium release from the bone mineral. The mineral is even modified in such a way that sodium ions are then fixed more strongly than in the native bone (formed experiments with native bone yielded a two-exponential curve with T values of 4.36 and 167 h).     

Interpretation of 41Ca data using compartmental modeling in post-menopausal women

Calcium-41 (t(1/2) = 10(5) years) can be used after a single dose to follow calcium metabolism over a subject's lifetime. The aims of this study were to expand a (41)Ca kinetic model and estimate bone resorption in women with stable bone loss, compare the rates with those calculated with classical isotope studies, and to use the model to simulate dynamic changes in urinary (41)Ca:Ca ratios and bone balance for the design and interpretation of (41)Ca studies. Forty-two women >5 years post-menopause were given (41)Ca intravenously. Bone mineral content and bone mineral density of total body were measured by dual-energy X-ray absorptiometry at the beginning of the study. Urine collections were made periodically for up to ~5 years while subjects were free living. Urinary (41)Ca:Ca ratios were measured using accelerator mass spectrometry. The isotope data were analyzed by compartmental modeling. Four compartments were necessary to fit the urinary tracer data and total bone calcium. The final model included pathways for absorption, distribution, urinary excretion, and endogenous excretion and was used to calculate rates of bone turnover. Estimates of bone resorption in a subset of the women (n = 13), studied previously in a 3-week balance and full kinetic study with (45)Ca, agreed with those using (41)Ca methodology. Thus, rates of bone resorption can be estimated from (41)Ca urinary data in stable post-menopausal women. The model was used to simulate dynamic changes in urinary (41)Ca:Ca ratios and bone balance, as a result of interventions that perturb calcium metabolism to aid in study design and interpretation.     

Kinetics of 1H --> 31P NMR cross-polarization in bone apatite and its mineral standards

Kinetics of NMR cross-polarization (CP) from protons to phosphorus-31 nuclei was studied in the following samples: mineral of whole human bone, apatite prepared from bone, natural brushite, synthetic hydroxyapatite (hydrated and calcined), and synthetic carbonatoapatite of type B with 9 wt% of CO(3) (2-). In order to avoid an effect of magic angle spinning on CP and relaxation, the experiments were carried out on static samples. Parameters of the CP kinetics were discussed for trabecular and cortical bone tissue from adult subjects in comparison to the synthetic mineral standards. It was found that carbonatoapatite shows similar CP behavior to the bone mineral. Both materials undergo two-component CP kinetics. The fast-relaxing classical component is from the surface of apatite crystals and the slow-relaxing nonclassical component comes from the crystal interior. The components have been unambiguously assigned using inverse CP from phosphorus-31 to protons. The study provides information on a structured water layer, which covers crystal surface of carbonato- and bone apatite. The layer encompasses ca 40% of apatite phosphorus and its thickness is more than ca 2 nm.     

Phosphorus-containing compounds regulate mineralization

Phosphorus is the main constitutive element of minerals and fat in the body. The process of mineral formation is defined as mineralization. The minerals in the body are mainly apatite, which is the inorganic phase that composes bones and teeth. It is worth noting that people with high fat content tend to cause excessive bone mineralization, which leads us to believe that different phosphorus-containing compounds in the body are mutually transformed and can regulate mineralization in different ways. The conversion and regulation of different phosphorus-containing compounds on the mineralization are essential for formation of a complex hierarchical structure and adaptation of the bone to various mechanical environments. Therefore, this review introduces the natural phosphorus-containing compounds in the body, introduces the hierarchical structure of the bone, and summarizes recent studies on different phosphorus-containing compounds (inorganic, organic, and phosphorus-containing proteases) involved in the biomineralization. We also discuss potential research directions of the biomineralization, offering the basis for future investigation of advanced bone substitute materials.     

纳米羟基磷灰石复合材料在硬组织工程领域中的应用研究

人体骨骼的晶体成分主要是纳米羟基磷灰石(n-HA),n-HA具有优良的生物相容性、骨传导性和骨结合能力,被广泛应用于硬组织修复材料中。本文综述了纳米羟基磷灰石在构建人体骨修复支架材料、骨替代材料和口腔医用材料方面的应用研究。