Bone Mineral Composition Research Articles

Bioceramics and bone healing.

Calcium phosphates have long been used as synthetic bone grafts. Recent studies have shown that the modulation of composition and textural properties, such as nano-, micro- and macro-porosity, is a powerful strategy to control and synchronize material resorption and bone formation.Biomimetic calcium phosphates, which closely mimic the composition and structure of bone mineral, can be produced using low-temperature processing routes, and offer the possibility to modulate the material properties to a larger extent than conventional high temperature sintering processes.Advanced technologies open up new possibilities in the design of bioceramics for bone regeneration; 3D-printing technologies, in combination with the development of hybrid materials with enhanced mechanical properties, supported by finite element modelling tools, are expected to enable the design and fabrication of mechanically competent patient-specific bone grafts.The association of ions, drugs and cells allows leveraging of the osteogenic potential of bioceramic scaffolds in compromised clinical situations, where the intrinsic bone regeneration potential is impaired.Cite this article: EFORT Open Rev 2018;3 DOI: 10.1302/2058-5241.3.170056

Synthetic nanosrystalline materials оf thepoli-variant composition based on the system СаО–P2О5–CаF2–Н2О for correction of structural disturbances of sceleton

The prospects for the use of synthetic nanocrystalline materials of a multivariate composition based on the system СаО–P2О5–CаF2–Н2О and additives for correcting structural defects of the skeleton are considered. It is shown that for the synthesis of nanocrystalline powders and composites of biomedical use, materials whose compositions are described by the system СаО–P2О5–CаF2–Н2О are promising. The systems of CаО–P2О5–CаF2, СаО–P2О5–Н2О were studied. A study of the CaO-P2O5-CaF2 system in the Ca3 (PO4) 2 -CaF2 section was carried out: the position of the binary eutectics and the melting points in them was determined. The experimental verification of the calculated data on the preparations of the calculated compositions by the high-temperature microscopy method is performed. On the basis of the investigations carried out, the regions of primary crystallization of phases in the four-component systems Ca3 (PO4)2-CaCO3-CaF2-Ca (OH) 2 and Ca3(PO4)2-H2O-CaF2-Ca (OH) 2, promising for use as bioceramic compositions. Based on the studies carried out in the CaO-P2O5-CaF2-H2O system, areas promising for the synthesis of materials have been identified that can be used for their technical and biological properties: 1) to correct bone tissue defects; 2) as inorganic fillers of hybrid organo-inorganic composite materials intended for the restoration of articular cartilage; 3) for gluing bone fragments and filling cavities of pathological origin; 4) to replenish the mineral composition of bones and tooth enamel.

Biomolecular regulation, composition and nanoarchitecture of bone mineral

Tough natural nanocomposites like bone, nacre and sea sponges contain within their hierarchy, a mineral (phosphate, silicate or carbonate) phase that interacts with an organic phase. In bone, the role of mineral ultrastructure (organization, morphology, composition) is crucial to the mechanical and biological properties of the tissue. Better understanding of mineral interaction with the organic matrix, in particular non-collagenous proteins, osteocalcin (OC) and osteopontin (OPN), can lead to better design of biomimetic materials. Using small angle x-ray scattering (SAXS) and wavelength dispersive spectroscopy (WDS) on single (OC−/− and OPN−/−) and double (OC-OPN−/−;−/−) genetic knockout mice bones, we demonstrate that both osteocalcin and osteopontin have specific roles in the biomolecular regulation of mineral in bone and together they are major determinants of the quality of bone mineral. Specifically, for the first time, we show that proteins osteocalcin and osteopontin regulate bone mineral crystal size and organization in a codependent manner, while they independently determine crystal shape. We found that OC is more dominant in the regulation of the physical properties of bone mineral, while OPN is more dominant in the regulation of the mineral composition.

Antiobesity potential of Piperonal: promising modulation of body composition, lipid profiles and obesogenic marker expression in HFD-induced obese rats

BackgroundBlack pepper or Piper nigrum is a well-known spice, rich in a variety of bioactive compounds, and widely used in many cuisines across the world. In the Indian traditional systems of medicine, it is used to treat gastric and respiratory ailments. The purpose of this investigation is to study the antihyperlipidemic and antiobesity effects of piperonal in high-fat diet (HFD)-induced obese rats.MethodsPiperonal, an active constituent of Piper nigrum seeds, was isolated and confirmed by HPLC, 1H and 13C NMR spectroscopy. Male SD rats were fed on HFD for 22 weeks; Piperonal was supplemented from the 16th week as mentioned in the experimental design. Changes in body weight and body composition were measured by TOBEC, bone mineral composition and density were measured by DXA, and adipose tissue distribution was measured by 7 T–MRI. Plasma levels of glucose, insulin, insulin resistance and lipid profiles of plasma, liver and kidney, adipocyte hormones and liver antioxidants were evaluated using standard kit methods. Expression levels of adipogenic and lipogenic genes, such as PPAR-γ, FAS, Fab-4, UCP-2, SREBP-1c, ACC, HMG-COA and TNF-α were measured by RT-PCR. Histopathological examination of adipose and liver tissues was also carried out in experimental rats.ResultsHFD substantially induced body weight, fat%, adipocyte size, circulatory and tissue lipid profiles. It elevated the plasma levels of insulin, insulin resistance and leptin but decreased the levels of adiponectin, BMC and BMD. Increased expression of PPAR-γ, FAS, Fab-4, UCP-2, SREBP-1c, ACC, and TNF-α was noticed in HFD-fed rats. However, supplementation of piperonal (20, 30 and 40 mg/kg b.wt) for 42 days considerably and dose-dependently attenuated the HFD-induced alterations, with the maximum therapeutic activity being noticed at 40 mg/kg b.wt.ConclusionsPiperonal significantly attenuated HFD-induced body weight and biochemical changes through modulation of key lipid metabolizing and obesogenic genes. Our findings demonstrate the efficacy of piperonal as a potent antiobesity agent, provide scientific evidence for its traditional use and suggest the possible mechanism of action.

Influence of physical activity on tibial bone material properties in laying hens

Laying hens develop a type of osteoporosis that arises from a loss of structural bone, resulting in high incidence of fractures. In this study, a comparison of bone material properties was made for lines of hens created by divergent selection to have high and low bone strength and housed in either individual cages, with restricted mobility, or in an aviary system, with opportunity for increased mobility. Improvement of bone biomechanics in the high line hens and in aviary housing was mainly due to increased bone mass, thicker cortical bone and more medullary bone. However, bone material properties such as cortical and medullary bone mineral composition and crystallinity as well as collagen maturity did not differ between lines. However, bone material properties of birds from the different type of housing were markedly different. The cortical bone in aviary birds had a lower degree of mineralization and bone mineral was less mature and less organized than in caged birds. These differences can be explained by increased bone turnover rates due to the higher physical activity of aviary birds that stimulates bone formation and bone remodeling. Multivariate statistical analyses shows that both cortical and medullary bone contribute to breaking strengthThe cortical thickness was the single most important contributor while its degree of mineralization and porosity had a smaller contribution. Bone properties had poorer correlations with mechanical properties in cage birds than in aviary birds presumably due to the greater number of structural defects of cortical bone in cage birds.

Effects of neutral phytase on growth performance and phosphorus utilization in crucian carp (Carassius auratus).

A feeding trial was conducted for nine weeks to investigate the effects of partially replacing Ca(H2PO4)2 with neutral phytase on the growth performance, phosphorus utilization, nutrient digestibility, serum biochemical parameters, bone and carcass mineral composition, and digestive-enzyme-specific activity in crucian carp (Carassius auratus). The diets prepared with 0.8%, 0%, and 1.8% Ca(H2PO4)2 (1%=1 g/100 g) supplements were regarded as the P1E0, negative control (NC), and positive control (PC) groups, respectively; the other three experimental diets were prepared with the addition of 200, 300, and 500 U/kg of neutral phytase, respectively, based on the P1E0 group. Three hundred and eighty-four fish ((1.50±0.01) g) were randomly distributed in the six treatments with four replicates each. The fish were initially fed with 2%-3% diets of their body weight per day, with feeding twice daily (08:00 and 16:00), under a 12-h light/12-h dark cycle at the temperature of (27.56±0.89) °C. The results showed that supplemental phytase at different levels in the diet improved the final body weight, average daily gain, feed conversion ratio, phosphorus utilization, and protein efficiency ratio of crucian carp (P<0.05). Phytase supplementation increased the mineral content in serum (P), bone (P, Ca), and carcass (P, Ca, Zn, Na, and Mg) (P<0.05); the trypsin and chymotrypsin activity soared when fed with the phytase-supplemented diets (P<0.05). We may conclude that supplemental dietary neutral phytase improved the growth performance, phosphorus utilization as well as nutrient utilization in crucian carp, and it can be considered an important nutritional replacement for Ca(H2PO4)2.

Low Doses of Simvastatin Potentiate the Effect of Sodium Alendronate in Inhibiting Bone Resorption and Restore Microstructural and Mechanical Bone Properties in Glucocorticoid-Induced Osteoporosis.

By using an experimental model of dexamethasone-induced osteoporosis we investigated the effects of different therapeutic schemes combining sodium alendronate (SA) and simvastatin on bone mineral and protein composition, microstructural and mechanical remodeling. Wistar rats were randomized into eight groups: G1: non-osteoporotic; G2: osteoporotic; G3, G4, and G5: osteoporotic+SA (0.2, 0.4, and 0.8 mg/kg, respectively); G6, G7, and G8: osteoporotic+SA (0.2, 0.4, and 0.8 mg/kg, respectively)+simvastatin (0.4, 0.6, and 1 mg/kg, respectively). Osteoporosis was induced by dexamethasone (7 mg/kg, i.m.) once a week for 5 weeks. All treatments were administered for 8 weeks. Dexamethasone increased serum levels of alkaline phosphatase, calcium, phosphorus, and urea, especially in non-treated animals, which showed severe osteoporosis. Dexamethasone also induced bone microstructural fragility and reduced mechanical resistance, which were associated with a marked depletion in mineral mass, collagenous and non-collagenous protein levels in cortical and cancellous bone. Although SA has attenuated osteoporosis severity, the effectiveness of drug therapy was enhanced combining alendronate and simvastatin. The restoration in serum parameters, organic and inorganic bone mass, and mechanical behavior showed a dose-dependent effect that was potentially related to the complementary mechanisms by which each drug acts to induce bone anabolism, accelerating tissue repair.

Rearing system affects prevalence of keel-bone damage in laying hens: a longitudinal study of four consecutive flocks

High flock-level prevalence of keel-bone fractures and deviations in laying hens are commonly reported across various housing systems; however, few longitudinal studies exist, especially for furnished and conventional cage systems. Load-bearing exercise improves bone strength and mineral composition in laying hens and has the potential to reduce keel-bone damage, especially if exercise is allowed during critical periods of bone growth throughout the pullet rearing phase. The objective of this study was to determine the prevalence of keel-bone damage in laying hens housed in furnished and conventional cages, and assess whether opportunities for exercise during the pullet rearing phase influenced the prevalence of keel-bone damage throughout the laying period. Four flock replicates of 588 Lohmann Selected Leghorn-Lite pullets/flock were reared in either conventional cages (Conv) or an aviary rearing system (Avi) and placed into conventional cages (CC), 30-bird furnished cages (FC-S) or 60-bird furnished cages (FC-L) for adult housing. Keel-bone status was determined by palpation at 30, 50, and 70 wk of age. Age (P < 0.001) and rearing system (P < 0.001) had an effect on the presence of keel-bone fractures. The presence of fractures increased with age, and hens raised in the Avi system had a lower percentage of fractures (41.6% ± 2.8 SE) compared to hens reared in the Conv system (60.3% ± 2.9 SE). Adult housing system did not have an effect on the percentage of keel fractures (P = 0.223). Age had an effect on the presence of deviations (P < 0.001), with deviations increasing with age. Rearing system (P = 0.218) and adult housing system (P = 0.539) did not affect the presence of deviations. Keel fractures and deviations were strongly associated with each other at all ages: 30 wk: (P < 0.001); 50 wk: (P < 0.001); and 70 wk: (P < 0.001). Increased opportunities for exercise provided by an aviary rearing system reduced the prevalence of keel-bone fractures through the end-of-lay.

Hydroxyapatite-polymer biocomposites for bone regeneration: A review of current trends.

Bone tissue engineering has emerged as one of the most indispensable approaches to address bone trauma in the past few decades. This approach offers an efficient and a risk-free alternative to autografts and allografts by employing a combination of biomaterials and cells to promote bone regeneration. Hydroxyapatite (HA) is a ceramic biomaterial that mimics the mineral composition of bones and teeth in vertebrates. HA, commonly produced via several synthetic routes over the years has been found to exhibit good bioactivity, biocompatibility, and osteoconductivity under both in vitro and in vivo conditions. However, the brittle nature of HA restricts its usage for load bearing applications. To address this problem, HA has been used in combination with several polymers in the form of biocomposite implants to primarily improve its mechanical properties and also enhance the implants' overall performance by simultaneously exploiting the positive effects of both HA and the polymer involved in making the biocomposite. This review article summarizes the past and recent developments in the evolution of HA-polymer biocomposite implants as an "ideal" biomaterial scaffold for bone regeneration. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 2046-2057, 2018.

A Natural, Calcium-Rich Marine Multi-mineral Complex Preserves Bone Structure, Composition and Strength in an Ovariectomised Rat Model of Osteoporosis.

Calcium supplements are used as an aid in the prevention of osteopenia and osteoporosis and also for the treatment of patients when used along with medication. Many of these supplements are calcium carbonate based. This study compared a calcium-rich, marine multi-mineral complex (Aquamin) to calcium carbonate in an ovariectomised rat model of osteoporosis in order to assess Aquamin's efficacy in preventing the onset of bone loss. Animals were randomly assigned to either non-ovariectomy control (Control), ovariectomy (OVX) plus calcium carbonate, ovariectomy plus Aquamin or ovariectomy plus Aquamin delay where Aquamin treatment started 8weeks post OVX. At the end of the 20-week study, the trabecular architecture was measured using micro computed tomography, bone composition was assessed using Fourier transform infrared spectroscopy and the mechanical properties were assessed using nanoindentation and three-point bend testing. The study demonstrates that oral ingestion of Aquamin results in less deterioration of trabecular bone structure, mineral composition and tissue level biomechanical properties in the tibia of rats following ovariectomy than calcium carbonate. This study has shown that in an animal model of osteoporosis, Aquamin is superior to calcium carbonate at slowing down the onset of bone loss.

* Biomineralized Recombinant Collagen-Based Scaffold Mimicking Native Bone Enhances Mesenchymal Stem Cell Interaction and Differentiation.

The need of synthetic bone grafts that recreate from macro- to nanoscale level the biochemical and biophysical cues of bone extracellular matrix has been a major driving force for the development of new generation of biomaterials. In this study, synthetic bone substitutes have been synthesized via biomimetic mineralization of a recombinant collagen type I-derived peptide (RCP), enriched in tri-amino acid sequence arginine-glycine-aspartate (RGD). Three-dimensional (3D) isotropic porous scaffolds of three different compositions are developed by freeze-drying: non-mineralized (RCP, as a control), mineralized (Ap/RCP), and mineralized scaffolds in the presence of magnesium (MgAp/RCP) that closely imitate bone composition. The effect of mineral phase on scaffold pore size, porosity, and permeability, as well as on their in vitro kinetic degradation, is evaluated. The ultimate goal is to investigate how chemical (i.e., surface chemistry and ion release from scaffold) together with physical signals (i.e., surface nanotopography) conferred via biomimetic mineralization can persuade and guide mesenchymal stem cell (MSC) interaction and fate. The three scaffold compositions showed optimum pore size and porosity for osteoconduction, without significant differences between them. The degradation tests confirmed that MgAp/RCP scaffolds presented higher reactivity under physiological condition compared to Ap/RCP ones. The in vitro study revealed an enhanced cell growth and proliferation on MgAp/RCP scaffolds at day 7, 14, and 21. Furthermore, MgAp/RCP scaffolds potentially promoted cell migration through the inner areas reaching the bottom of the scaffold after 14 days. MSCs cultured on MgAp/RCP scaffolds displayed higher gene and protein expressions of osteogenic markers when comparing them with the results of those MSCs grown on RCP or Ap/RCP scaffolds. This work highlights that mineralization of recombinant collagen mimicking bone mineral composition and morphology is a versatile approach to design smart scaffold interface in a 3D model guiding MSC fate.

Osteoblast and osteoclast responses to A/B type carbonate-substituted hydroxyapatite ceramics for bone regeneration

The influence of carbonate substitution (4.4 wt%, mixed A/B type) in hydroxyapatite ceramics for bone remodeling scaffolds was investigated by separately analyzing the response of pre-osteoblasts and osteoclast-like cells. Carbonated hydroxyapatite (CHA) (Ca9.5(PO4)5.5(CO3)0.5(OH)(CO3)0.25-CHA), mimicking the chemical composition of natural bone mineral, and pure hydroxyapatite (HA) (Ca10(PO4)6(OH)2-HA) porous ceramics were processed to obtain a similar microstructure and surface physico-chemical properties (grain size, porosity ratio and pore size, surface roughness and zeta potential). The biological behavior was studied using MC3T3-E1 pre-osteoblastic and RAW 264.7 monocyte/macrophage cell lines. Chemical dissolution in the culture media and resorption lacunae produced by osteoclasts occur with both HA and CHA ceramics, but CHA exhibits much higher dissolution and greater bioresorption ability. CHA ceramics promoted a significantly higher level of pre-osteoblast proliferation. Osteoblastic differentiation, assessed by qRT-PCR of RUNX2 and COLIA2, and pre-osteoclastic proliferation and differentiation were not significantly different on CHA or HA ceramics but cell viability and metabolism were significantly greater on CHA ceramics. Thus, the activity of both osteoclast-like and osteoblastic cells was influenced by the carbonate substitution in the apatite structure. Furthermore, CHA showed a particularly interesting balance between biodegradation, by osteoclasts and chemical dissolution, and osteogenesis through osteoblasts’ activity, to stimulate bone regeneration. It is hypothesized that this amount of 4.4 wt% carbonate substitution leads to an adapted concentration of calcium in the fluid surrounding the ceramic to stimulate the activity of cells. These results highlight the superior biological behavior of microporous 4.4 wt% A/B CHA ceramics that could beneficially replace the commonly used HA of biphasic calcium phosphates for future applications in bone tissue engineering.

Effect of Low- And High Phytase Barley on Phosphorus Retention and Bone Mineral Composition in Broilers

The effects of low‑phosphorus diets with two levels of phytase were examined in broiler chickens using eight replicates per treatment. The diets contained 40 % of spring barley with either 201 or 305 phytase activity units per kg. Chromic oxide was included in the diets as an indigestible marker. Excreta were collected during four consecutive three‑day balance periods from the 12thto the 23rdday of age. No difference was observed for body weight gain between the dietary treatment groups but feed conversion ratio was better (P &lt; 0.05) when higher phytase barley was used. In spite of the higher dietary level of phosphorus, the coefficient of apparent P retention was higher (P &lt; 0.01) in higher than in lower phytase group. The retention of phosphorus increased (P &lt; 0.01) with time of feeding in both low‑phosphorus dietary groups. Differences between treatments in concentration of calcium, phosphorus, magnesium, sodium and potassium in defatted tibia were not significant (P &gt; 0.05).

Region specific Raman spectroscopy analysis of the femoral head reveals that trabecular bone is unlikely to contribute to non-traumatic osteonecrosis

Non-traumatic osteonecrosis (ON) of the femoral head is a common disease affecting a young population as the peak age of diagnosis is in the 40 s. The natural history of non-traumatic ON leads to a collapse of the femoral head requiring prosthetic replacement in a 60% of cases. Although trabecular bone involvement in the collapse is suspected, the underlying modifications induced at a molecular level have not been explored in humans. Here, we examine changes in the molecular composition and structure of bone as evaluated by Raman spectroscopy in human end-stage ON. Comparing samples from femoral heads harvested from 11 patients and 11 cadaveric controls, we show that the mineral and organic chemical composition of trabecular bone in ON is not modified apart from age-related differences. We also show that the molecular composition in the necrotic part of the femoral head is not different from the composition of the remaining ‘healthy’ trabecular bone of the femoral head. These findings support that quality of trabecular bone is not modified during ON despite extensive bone marrow necrosis and osteocyte death observed even in the ‘healthy’ zones on histological examination.

사육밀도와 사료 단백질 수준이 저속 성장 육계(한협 3호)의 성장, 육질, 혈청 Corticosterone에 미치는 영향

세 수준(6.3, 9.5, 12.6 수/<TEX>$m^2$</TEX>)의 사육밀도와 사료 단백질 수준(19%, 18%)이 저속성장 육계(한협 3호)의 육성성적, 영양소 이용률, 닭고기 저장성, 육색, 계육 성분 및 뼈의 광물질 조성과 혈청 corticosterone 함량에 미치는 영향을 조사하였다. 사육 밀도는 한협 3호 육성성적에 유의적인 영향을 미치는 것으로 나타났다. 증체량은 저 밀도인 6.3 수/<TEX>$m^2$</TEX> 구에서 가장 높았으며, 고밀도(12.6 수/<TEX>$m^2$</TEX>) 구에서 가장 낮았다. 특히 고사육 밀도에서는 사료섭취량이 유의적으로 감소한 것으로 나타났다. 그러나 낮은 사료섭취량으로 인하여 고사육 밀도 계군의 사료요구율이 타 사육 밀도 계군의 사료요구율에 비하여 상대적으로 낮았다. 고밀도 계군에서의 사료 섭취량 저하와 낮은 사료요구율은 41~60일 구간보다는 61~75일 구간에 현저하게 나타났는데, 그 영향으로 전 사육기간의 사료섭취량과 사료요구율도 차이가 나타났다. 본 연구에서 사료 단백질 1% 차이는 증체량과 사료요구율에 차이를 나타내지 않았다. 다만 41~75일 구간 사료섭취량은 단백질 19% 구에 비하여 오히려 18% 구에서 낮았다. 저장 중 계육의 TBARS 값은 처리구간에 차이가 없었다. 하지만 계육의 적색도와 명도는 사료 단백질 수준에 따라, 황색도는 사육 밀도에 따라 차이가 나타났다. 가슴육의 단백질 함량과 다리육의 Ca과 P의 함량은 각각 사료 단백질 수준과 사육밀도에 영향을 받았다. 사료의 단백질 수준과 사육밀도는 뼈의 회분함량 및 회분 중 Ca과 P의 함량에는 영향을 미치지 않았다. 혈청 corticosterone 함량은 사육밀도가 낮을수록 낮게 나타났으나, 사료 단백질 수준에 따른 차이는 없었다. 본 연구 결과, 저속성장 육계 한협 3호 사육후기 단계에 고사육 밀도(12.6 수/<TEX>$m^2$</TEX>)로 사육하는 것은 생산성을 하락시킬 뿐 아니라, 혈청 corticosterone 함량도 높이므로 바람직하지 않음을 알 수 있었다. 또한 한협 3호 육계의 후기 사료 단백질을 18% 수준으로 설계하더라도 생산성에 차이가 없음을 알게 되었다. A total of 720 slow-growing Korean meat-type (Hanhyop 3) chicken were used to evaluate the effect of stocking densities and dietary protein levels on growth performance, meat quality, bone mineral composition, and serum corticosterone. Three (6.3, 9.5, and <TEX>$12.6birds/m^2$</TEX>) stocking densities and two dietary protein levels (19% and 18%) were factorially (<TEX>$3{\times}2$</TEX>) arranged for six treatments. Overall body weight gain (BWG) was highest (p<0.001) at the lowest stocking density (<TEX>$6.3birds/m^2$</TEX>). The feed intake (FI) of birds at the highest density (<TEX>$12.6birds/m^2$</TEX>) was lower than that of birds at the other densities, but resulted in better feed/gain (F/G). Among 18% protein groups, the overall FI of birds at <TEX>$9.5birds/m^2$</TEX> was higher than that at the lowest density; therefore, birds at <TEX>$9.5birds/m^2$</TEX> had poorer F/G than birds at the lowest density during days 61~75. Difference in F/G among densities was only significant (p<0.05) during days 61~75 but not significant (p>0.05) during days 41~60. Although there were no significant differences (p>0.05) in BWG and F/G between 19% and 18% dietary protein levels, FI of the 18% protein diet was less (p<0.05) than that of the 19% diet. Although there was no difference (p>0.05) in meat TBARS values, meat color differed (p<0.05) with stocking density and dietary protein levels. There was no effect (p>0.05) of stocking density and dietary protein levels on bone mineral composition. Serum corticosterone concentration increased (p<0.05) with increasing stock density but was not affected (p>0.05) by dietary protein levels. This study indicated that a density of <TEX>$12.6birds/m^2$</TEX> is not recommended for slow-growing chickens. Between 19% and 18% dietary protein levels, 18% would be recommended for the Korean Hanhyop 3 chicken in the finishing stage.

The effect of brisk walking on postural stability, bone mineral density, body weight and composition in women over 50years with a sedentary occupation: a randomized controlled trial.

BackgroundTo assess the effect of brisk walking on postural stability, bone mineral density (BMD) and body composition in women over 50 years of age with a sedentary occupation.MethodsA 10-week walking intervention based on self-regulated brisk walking (BW) to or from work of 30–35 min at least 5 times per week. The research included a total of 104 women (58 women in intervention group). The mean center of pressure (COP) velocity in medial-lateral and anterior-posterior directions, mean total COP velocity with eyes open and closed, BMD of the distal forearm and the calcaneus, body weight, fat mass, and lean body mass were assessed.ResultsThe BW intervention was completed by 76 % of participants. A significant effect (time × group interaction) was confirmed only in the mean COP velocity in the anterior-posterior direction with eyes closed (F = 7.41, P = 0.008). The effect of BW was not confirmed in BMD, body weight, or body composition. The results indicate that the effect of the intervention is influenced by baseline body mass index in body weight, fat mass and visceral adipose tissue.ConclusionsBW prevents the deterioration of postural stability with eyes closed, which can have a direct effect on reducing the risk of falls under worse spatial orientation and visibility. The presented intervention model is insufficient for weight loss, changes in BMD, or body composition, and its effect should be assessed during a longer period of time.Trial registrationGerman Clinical Trials Register DRKS00007638, registered March 10, 2015 (retrospectively registered).

Alterations in geometry, biomechanics, and mineral composition of juvenile rat femur induced by nonplanar PCB-155 and/or planar PCB-169.

Exposure to widespread lipophilic and bioaccumulative polychlorinated biphenyls (PCBs) induces diverse biochemical and toxicological responses in various organs, including the bone. The aim of this study was to evaluate the changes in growth rate, geometry, serum, and bone biochemical parameters and biomechanics of juvenile rat femur induced by lactational exposure to nonplanar PCB-155 and planar PCB-169 individually and in combination. Fifteen lactating Wistar rats were divided into four groups (PCB-169, PCB-155, PCB-155+169, and control), and PCBs were administered intraperitoneally at different time points after delivery. Femurs from 22-day-old offspring were analyzed by microCT, three-point bending test and inductively coupled plasma-mass spectrometry (ICP-MS) to obtain data on bone geometry, biomechanics and mineral composition. The serum levels of calcium, phosphate and alkaline phosphatase were also determined. Lactational exposure to planar PCB-169 resulted in shorter and thinner femurs, reduced endosteal and periosteal perimeters, smaller total cross-sectional and medullary areas, and lowered serum bone marker levels and calcium levels in the bone, while femur mechanical properties were not significantly altered. The changes observed in the combination exposure (PCB-155+169) group were similar to those observed in the PCB-169 group but were less pronounced. In summary, our results demonstrate that alterations in lactationally exposed offspring were primarily induced by planar PCB-169. The milder outcome in the combined group suggested that the PCB-169-mediated toxic effects on the bone might be reduced by a nonplanar PCB-155 congener. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 1135-1146, 2017.

Development and Characterization of Porous Biphasic Calcium Phosphate Bone Graft from Natural Biological Origin Raw Material for Biomedical Application

Hydroxyapatite (Ca10(PO4)6(OH2), HA has similarities with human bone mineral composition and morphology, bioactive, and non-toxic. However, HA has a weakness in the decay of material, so it can inhibit the growth of new bone tissue. The other materials used as biodegradable bone substitute are Tri Calcium Phosphate (TCP). It has the reception of the body is almost as good as HA but it have fast decay time, so that the material has been discharged before the newly formed tissue. This study aimed to developed a Biphasic Calcium Phosphate (BCP) which is a combination of the properties of HA and TCP, it makes the decay time can be in accordance with the growth of new bone tissue. Calcination method was used in this study. Four groups of bovine bone samples were calcined at four different temperatures ranging from 1000oC to 1300oC using the electric furnace. The heating rate during calcination process was 5oC/minute and dwell time of 2 hours. The calcined bioceramics samples are being examined to determine the characterization of materials. XRD testing to determine the chemical compounds, FTIR performed to determine the ionic bonds that exist in materials and SEM to determine the microstructure of the material calcination results. The current investigation confirms the possibility of producing porous BCP bone graft from porous bovine bone cube, without any important impurities as indicated by XRD and FT-IR techniques. The partially decomposition of HA into TCP was started when bovine bone samples were heated at 1200oC.

Mechanisms of osteocyte stimulation in osteoporosis

Experimental studies have shown that primary osteoporosis caused by oestrogen-deficiency results in localised alterations in bone tissue properties and mineral composition. Additionally, changes to the lacunar–canalicular architecture surrounding the mechanosensitive osteocyte have been observed in animal models of the disease. Recently, it has also been demonstrated that the mechanical stimulation sensed by osteocytes changes significantly during osteoporosis. Specifically, it was shown that osteoporotic bone cells experience higher maximum strains than healthy bone cells after short durations of oestrogen deficiency. However, in long-term oestrogen deficiency there was no significant difference between bone cells in healthy and normal bone. The mechanisms by which these changes arise are unknown. In this study, we test the hypothesis that complex changes in tissue composition and lacunar–canalicular architecture during osteoporosis alter the mechanical stimulation of the osteocyte. The objective of this research is to employ computational methods to investigate the relationship between changes in bone tissue composition and microstructure and the mechanical stimulation of osteocytes during osteoporosis. By simulating physiological loading, it was observed that an initial decrease in tissue stiffness (of 0.425GPa) and mineral content (of 0.66wt% Ca) relative to controls could explain the mechanical stimulation observed at the early stages of oestrogen deficiency (5 weeks post-OVX) during in situ bone cell loading in an oestrogen-deficient rat model of post-menopausal osteoporosis (Verbruggen et al., 2015). Moreover, it was found that a later increase in stiffness (of 1.175GPa) and mineral content (of 1.64wt% Ca) during long-term osteoporosis (34 weeks post-OVX), could explain the mechanical stimuli previously observed at a later time point due to the progression of osteoporosis. Furthermore, changes in canalicular tortuosity arising during osteoporosis were shown to result in increased osteogenic strain stimulation, though to a lesser extent than has been observed experimentally. The findings of this study indicate that changes in the extracellular environment during osteoporosis, arising from altered mineralisation and lacunar–canalicular architecture, lead to altered mechanical stimulation of osteocytes, and provide an enhanced understanding of changes in bone mechanobiology during osteoporosis.

Pathology and mineral composition of bone in the early stages of experimental osteomyelitis

Актуальность Изучение патогенетических закономерностей и характера структурных изменений в костной ткани на ранних стадиях острого остеомиелита является актуальным с точки зрения расширения представлений о механизмах развития осложнений у больных и проведения комплекса реабилитационных мероприятий.Цель работы Комплексная оценка патоморфологических изменений и особенностей минерального состава костной ткани на ранних стадиях развития острого остеомиелита в эксперименте.Материалы и методы Эксперименты проведены на 35 крольчатах обоего пола, в соответствии с биоэтическими требованиями. Острый гематогенный остеомиелит моделировали путем введения культуры стафилококка в костномозговой канал большеберцовой кости. Всех животных выводили из опыта под кратковременным эфирным наркозом путем воздушной эмболии через 30 мин. 6, 12, 24 и 48 часов после введения культуры стафилококка. На данных сроках эксперимента методами световой, электронной (сканирующей и трансмиссионной) микроскопии и рентгеновского электронно-зондового анализа изучались особенности патоморфологии и минерального состава костной ткани.Результаты и их обсуждение Во время первых 30 минут эксперимента микро- и ультрамикроскопические изменения в костной ткани были минимальными: сохранялись костные стержни с небольшими группами эритроцитов, а минеральный состав кости характеризовался снижением объемной доли натрия. На 6 часе эксперимента также не наблюдалось значительных структурных перестроек в костной ткани, однако происходило дальнейшее снижение концентрации натрия и магния, и увеличение объемной доли серы. В то же время, на данном сроке эксперимента отмечено повышение объемных долей кальция и фосфора. Морфологическая картина в последующие 12 часов эксперимента характеризовалась началом деструктивных процессов в костном мозге, с чем, вероятно, связаны некоторые перестройки минерального обмена костной ткани. Наблюдали резкое повышение концентрации натрия, при этом сохранялись высокие значения объемных долей внутрикостного кальция, фосфора и серы, что отражало повышенную минерализацию. К концу 1 суток эксперимента развивались процессы деструкции костной ткани, которые сопровождались деминерализацией. На 2 сутки отмечалась активация процессов остеогенеза, при этом деминерализация сохранялась.Заключение Таким образом, в течение 1-х суток от начала эксперимента структурные перестройки костной ткани отсутствуют, а изменения ее минерального состава связаны с процессами адаптации в ответ на активное воспаление в костномозговом канале. На 2-е сутки опыта развивающаяся деструкция костной ткани сопровождается явлениями остеопороза наряду с активацией остеосинтеза. Период в течение 1-х суток от попадания возбудителя можно рассматривать как наиболее благоприятный с точки зрения профилактики последующих осложнений.