Bone Growth Rate Research Articles

Impact of fluoride and aluminum co-exposure on bone growth and quality in juvenile rats: dose and duration effects

This study aimed to investigate the impact of the dosage and duration of fluoride and aluminum(F and Al) co-exposure on the skeletal growth and bone quality of juvenile rats. Forty-eight 8-week-old Sprague-Dawley rats were randomly assigned to normal control, low F and Al exposure, and high F and Al exposure groups, with 45-day and 90-day subgroups established for each. We measured body length, tibia length, conducted bone histomorphometric analysis of the proximal tibia, performed micro-CT scans and three-point bending tests of the femur. Compared to the age-matched control group, the low F and Al group at 45 days exhibited increased bone formation and stiffness; the low F and Al group at 90 days and the high F and Al group at 45 days showed increases in body length, tibia length, growth plate width, longitudinal bone growth rate, bone turnover, and improved microstructure. Notably, bone elastic stress only elevated in the high F and Al group at 45 days. Conversely, the high F and Al exposure group at 90 days experienced decreases in the aforementioned parameters, with the exception of growth plate width, and displayed abnormal hypertrophic chondrocyte morphology in the growth plate. In summary, long-term exposure to low levels of F and Al and short-term exposure to high levels of F and Al promote bone formation followed by bone resorption in juvenile rats, stimulating bone growth and enhancing bone quality. However, long-term exposure to high levels F and Al results in low bone turnover, slow bone growth, and reduced bone property.

Predicting ultrasound wave stimulated bone growth in bioinspired scaffolds using machine learning

For conditions like osteoporosis, changes in bone pore geometry even when porosity is constant have been shown to correlate to increased fracture risk using techniques such as dual-energy x-ray absorptiometry (DXA) and computed tomography (CT). Additionally, studies have found that bone pore geometry can be characterized by ultrasound to determine fracture risk, since certain pore geometries can cause stress concentration which in turn will be a source for fracture. However, it is not yet fully understood if changes in pore geometry can be detected by ultrasound when the porosity is constant. Therefore, this study develops an unsupervised machine learning model classifying pore geometry between bioinspired and quadrilateral pore scaffolds with constant porosity using experimental ultrasound wave transmission data. Our results demonstrate that differences in pore geometry can be detected by ultrasound, even at constant porosity, and that these differences can be distinguished in an unsupervised manner with machine learning. For traumatic bone injuries and late-stage osteoporosis where fracture occurs, tissue scaffolds are used to aid the healing of fractures or bone loss. The scaffold design is optimized to match material properties closely with bone, and healing can be enhanced with ultrasound stimulation. In this study we predict the combined effects of ultrasound parameters, such as wave frequency and mode of displacement, and scaffold material properties on bone tissue growth. We therefore develop an unsupervised machine learning clustering model of bone tissue growth in the scaffolds using finite element analysis and bone growth algorithms evaluating effects of pore geometry, scaffold materials, ultrasound wave type and frequency, and mesenchymal stem cell distribution on bone tissue growth. The computational predictions of tissue growth agreed within 10% of comparable experimental studies. The data corresponding to pore geometry, mesenchymal stem cell distribution, and scaffold material demonstrate distinct clusters of total bone formation, while ultrasound frequency and mesenchymal stem cell distribution show distinct clusters in bone growth rate. These variables can be tuned to tailor the scaffold design and optimize the required amount and rate of bone growth to meet a patient's specific needs.

In Vivo Investigation of 3D-Printed Calcium Magnesium Phosphate Wedges in Partial Load Defects.

Bone substitutes are ideally biocompatible, osteoconductive, degradable and defect-specific and provide mechanical stability. Magnesium phosphate cements (MPCs) offer high initial stability and faster degradation compared to the well-researched calcium phosphate cements (CPCs). Calcium magnesium phosphate cements (CMPCs) should combine the properties of both and have so far shown promising results. The present study aimed to investigate and compare the degradation and osseointegration behavior of 3D powder-printed wedges of CMPC and MPC in vivo. The wedges were post-treated with phosphoric acid (CMPC) and diammonium hydrogen phosphate (MPC) and implanted in a partially loaded defect model in the proximal rabbit tibia. The evaluation included clinical, in vivo µ-CT and X-ray examinations, histology, energy dispersive X-ray analysis (EDX) and scanning electron microscopy (SEM) for up to 30 weeks. SEM analysis revealed a zone of unreacted material in the MPC, indicating the need to optimize the manufacturing and post-treatment process. However, all materials showed excellent biocompatibility and mechanical stability. After 24 weeks, they were almost completely degraded. The slower degradation rate of the CMPC corresponded more favorably to the bone growth rate compared to the MPC. Due to the promising results of the CMPC in this study, it should be further investigated, for example in defect models with higher load.

Living with a tumor: A case of osteosarcoma involving the medullary region in Phrynops cf. P. geoffroanus (Testudines: Chelidae).

The individual Geoffroy's side-necked turtle, Phrynops cf. P. geoffroanus, was diagnosed postmortem with osteosarcoma associated with the forelimb through morphological and histological analysis. Osteosarcoma stands as the most prevalent primary malignant bone tumor in tetrapods. The tumor presents itself as a large mass in the distal epiphysis, characterized by spicular outgrowths and a rugose external texture. Histologically, the afflicted humerus displayed a high degree of vascularity and exhibited an extensive bone resorption process involving the medullary and endosteal regions. Notably, a clear transition between the bone marrow and cortical bone was absent, indicative of a remodeling process featuring Haversian bone system apposition. Additionally, the diaphyseal region displayed the progression of neoplastic bone tissue along the bone. For comparative purposes, we describe a humeral thin section from a healthy specimen revealing compact primary bone interrupted by cyclical growth marks which differs from the continuous growth observed in the neoplastic humerus. To assess the neoplastic bone growth rate at the mid-diaphysis level, phylogenetic eigenvector maps (PEM) were employed, utilizing osteocyte density and vascular density as explanatory variables. The findings indicated that the osteosarcoma exhibited a slow-growing nature, suggesting that the turtle had to live with this condition for years. As the neoplasia continued to expand, it likely led to disadvantages for the pathological Phrynops individual due to humeral deformity. Furthermore, malignancy was associated with angiogenesis and the invasion of the medullary region by neoplastic bone tissue, raising the likelihood of metastasis as an additional factor contributing to the individual's sickness. The presence of numerous vascular canals in the diaphyseal thin section suggested a low-grade central osteosarcoma. It is worth noting that osseous neoplasms are rarely documented in Testudines, making this case of osteosarcoma in a South American freshwater chelid specimen a unique and rare occurrence.

Enhancing the bioactivity and ductility of bulk metallic glass by introducing Fe to construct semi-degradable biomaterial

Porous Ti–Zr–Cu–Pd–Sn bulk metallic glass (BMG) produced by Spark Plasma Sintering (SPS) in our previous work demonstrates bone-like mechanical properties, effectively mitigating the issue of stress shielding within the implant. Nevertheless, concerns persist regarding the BMG's brittleness and its lack of bioactivity, both of which pose concealed risks in practical applications. In light of these challenges, a semi-degradable biomaterial, the MG-Fe composites, has been meticulously crafted via SPS in this work. The incorporation of ductile Fe phase in the MG matrix significantly enhances its plasticity. Moreover, the degradation of Fe results in the deposition of Ca–P compounds, imbuing the MG-Fe composites with a degree of bioactivity. Furthermore, by introducing a gradient porous structure, researchers have managed to fine-tune the mechanical properties of the MG-Fe composites. This innovative design imparts plastic and ductile compression deformation behavior to the gradient porous MG-Fe composites, offering a potential solution to the issue of brittle fracture behavior observed in conventional brittle BMGs. In addition, the introduction of the gradient porous structure serves to further accelerate the degradation rate of Fe. This advancement holds the potential to strike a dynamic balance with the growth rate of human bone, further elevating the bioactivity of the MG-Fe composites.

Exploring the bio-mechanical behavior of PEEK and CFR-PEEK materials for dental implant applications using finite element analysis.

This study explored the bio-mechanical properties of polyether ether ketone (PEEK) and carbon fiber reinforced-PEEK (CFR-PEEK) as potential alternatives to traditional dental implant materials, such as titanium (Ti) and zirconia (ZrO2). Conventional implant materials often exhibit stress shielding leading to peri-implant bone loss and implant failure. Finite element analysis using a three-dimensional computer-aided-design (3D CAD) model of the jawbone with various implant materials (titanium, zirconia, PEEK, and CFR-PEEK) incorporated was implemented to assess the effectiveness of PEEK and CFR-PEEK. Two loading conditions (50 and 100 N) were applied in centric (case-1) and eccentric (case-2) to mimic the oral loading conditions. Titanium and zirconia implants were found to exhibit higher levels of stress shielding and therefore pose greater risks of bone loss and implant failure. Conversely, CFR-PEEK implants demonstrated more-uniform stress distributions that reduce the likelihood of stress shielding compared to their conventional counterparts; consequently, CFR-PEEK implants are particularly suitable for load-bearing applications. Furthermore, maximum strain values on PEEK-implanted cortical bone reached a state of adaptation, referred to as the "lazy zone" in which bone growth and bone loss rates are equal, indicating PEEK's potential for a long-term implant utilization. PEEK and CFR-PEEK implants are promising alternatives to conventional dental implants because they provide stress shielding and promote bone health. Improved stress distribution enhances long-term success and durability while mitigating complications, and highlights their applicability to dental implant procedures.

PRMT1-mediated arginine methylation promotes postnatal calvaria bone formation through BMP-Smad signaling.

PRMT1 deficiency leads to severely compromised craniofacial development in neural crest cells and profound abnormalities of the craniofacial tissues. Here, we show PRMT1 controls several key processes in calvarial development, including frontal and parietal bone growth rate and the boundary between sutural and osteogenic cells. Pharmacologic PRMT1 inhibition suppresses MC3T3-E1 cell viability and proliferation and impairs osteogenic differentiation. In this text, we investigate the cellular events behind the morphological changes and uncover an essential role of PRMT1 in simulating postnatal bone formation. Inhibition of PRMT1 alleviated BMP signaling through Smads phosphorylation and reduced the deposition of the H4R3me2a mark. Our study demonstrates a regulatory mechanism whereby PRMT1 regulates BMP signaling and the overall properties of the calvaria bone through Smads methylation, which may facilitate the development of an effective therapeutic strategy for craniosynostosis.

A Novel PTH-Related Peptide Combined With 3D Printed Macroporous Titanium Alloy Scaffold Enhances Osteoporotic Osseointegration.

Previous parathyroid hormone (PTH)-related peptides (PTHrPs) cannot be used to prevent implant loosening in osteoporosis patients due to the catabolic effect of local sustained release. A novel PTHrP (PTHrP-2) that can be used locally to promote osseointegration of macroporous titanium alloy scaffold (mTAS) and counteract implant slippage in osteoporosis patients is designed. In vitro, PTHrP-2 enhances the proliferation, adhesion, and osteogenic differentiation of bone marrow-derived mesenchymal stem cells (BMSCs) within the mTAS. Further, it promotes proliferation, migration, angiogenesis-related protein expression, and angiogenesis in human umbilical vein endothelial cells (HUVECs). Compared to PTH(1-34), PTHrP-2 can partially weaken the osteoclast differentiation of RAW 264.7 cells. Even in an oxidative stress microenvironment, PTHrP-2 safeguards the proliferation and migration of BMSCs and HUVECs, reduces reactive oxygen species generation and mitochondrial damage, and partially preserves the angiogenesis of HUVECs. In the Sprague-Dawley (SD) rat osteoporosis model, the therapeutic benefits of PTHrP-2-releasing mTAS (mTASP2 ) and ordinary mTAS implanted for 12 weeks via micro-CT, sequential fluorescent labeling, and histology are compared. The results demonstrate that mTASP2 exhibits high bone growth rate, without osteophyte formation. Consequently, PTHrP-2 exhibits unique local synthesis properties and holds the potential for assisting the osseointegration of alloy implants in osteoporosis patients.

Investigation of the electrochemical behavior of titanium dioxide coating on magnesium alloy

Biocompatibility and electrochemical corrosion resistance are one of the most important issues in bone implants. In the last decades, metal implants have received much attention because of their properties. Magnesium and its alloys have been widely used in orthopedics because of their biocompatibility and bone growth proprieties. Magnesium has low corrosion resistance; especially in biological environments of the body, or when exposed to blood plasma, this makes magnesium useful as an absorbable implant. To increase the corrosion resistance of magnesium alloys, and adjust the corrosion rate of the implant to the rate of bone growth, it is necessary to coat these implants. Ceramic coatings are one of the possibilities, because of their biocompatibility and high corrosion resistance. TiO2 possesses desirable properties, such as an excellent mechanical features, high corrosion resistance, and biocompatibility, which make it widely used as implant coatings material. Sol-gel is one of the effective methods for making various ceramic materials. In this study, the electrochemical properties of magnesium alloy Mg-5Gd-2.5Nd-0.5Zn-0.5Zr with and without coating with phosphate-buffered saline (PBS) are investigated through Tafel extrapolation and impedance test Titanium dioxide coating was applied to the alloys by the sol-gel method. The effect of four variables of fluoride ion content, etching time, immersion time, and the number of immersions were studied. The results of SEM images showed the optimal sample surface of a uniform coating with a thickness of 6 μm. The optimal sample corrosion current density reported 2.58 × 10−5 A/m2, which is the lowest current density in samples. The results of the impedance test also confirmed these data and the optimal sample indicated the highest value of Rp = 5003 Ω.cm2.

Paleohistology of Caraguatypotherium munozi (Mammalia, Notoungulata, Mesotheriidae) from the early late Miocene of northern Chile: A preliminary ontogenetic approach.

The Miocene Caragua fossil fauna in northern Chile contains a considerable number (7) of articulated partial skeletons tentatively assigned to Caraguatypotherium munozi (Notoungulata, Mesotheriidae), which presents up to 40% body size difference. Since either inter- and intra- specific wide size range has been observed in the Mesotheriidae family in general, we wanted explore the ontogenic stage signature of the sample, by carrying out the first comprehensive paleohistological description of the appendicular system in Notoungulata. Results show that: 1) they can be classified as subadults and adults, based on the presence of bone tissues typical of ceased somatic growth; 2) there is a notorious inter-skeletal variation on bone growth rates (skeletal modularity), particularly, the humerus showed a slower diameter growth and less remodelling than the femur, resulting as a better element for ontogenetic analyses; 3) marked cyclical growth is observed, characterised by fast early ontogenic continuous growth, and subsequent fast/slow stratified bone tissue layering. In general, such growth pattern suggests that C. munozi had a similar ontogenetic growth process as other modern mammals, that it should also be influenced by other sex-related, ecological and environmental factors. Likely related to the presence of rapid climatic variations, due to orogenic uplift and concomitant re-organization of the drainage processes along the western tectonic front of the Central Andes at that time.

Proteomic Identification of Plasma Components in Tachypleus tridentatus and Their Effects on the Longitudinal Bone Growth Rate in Rats.

Tachypleus tridentatus (T. tridentatus) is a marine animal and traditional Chinese medicine. T. tridentatus plasma is a valuable resource for important medical and health-based functions. In this experiment, in order to evaluate the effect and mechanism of T. tridentatus plasma with respect to the promotion of bone tissue growth in rats, the processes of ultrafiltration and mass spectrometry were first used to separate and identify the components of T. tridentatus plasma. Then, a comparison of the effects of the T. tridentatus plasma samples, which each possessed different molecular weights, regarding the growth of the long bones of rats was conducted. Finally, transcriptomics, proteomics, and bioinformatics were all used to analyze the biological functions and related signaling pathways of the T. tridentatus plasma in order to promote rat bone growth. The results showed that the contents of amino acid residues in peptides are related to the growth promotion that was contained in the 10-30 kDa plasma group. Moreover, the T. tridentatus plasma samples were found to be higher in this respect than those in the whole plasma group. In addition, the 10-30 kDa plasma group could significantly promote bone growth activity in rats. The proteomic analysis showed that the proteins that were differentially expressed in the 10-30 kDa plasma group were mainly enriched in the PI3K-AKT signal pathway. Our study suggested that the T. tridentatus plasma possesses promising potential for the purposes of clinical use, whereby it can serve the role of a growth-promoting agent.

Reduced bone formation and increased bone resorption drive bone loss in Eimeria infected broilers

Coccidiosis is an economically significant disease in the global poultry industry, but little is known about the mechanisms of bone defects caused by coccidiosis; thus, the study focused on effects of coccidiosis on the bone homeostasis of young broiler chickens. A total of 480 male Cobb500 broilers were randomly allocated into four treatment groups, including an uninfected control consuming diet ad libitum, two infected groups were orally gavaged with two different concentrations of sporulated Eimeria oocysts, and an uninfected pair-fed group fed the same amount of feed as the high Eimeria-infected group consumed. Growth performance and feed intake were recorded, and samples were collected on 6 days post infection. Results indicated that coccidiosis increased systemic oxidative status and elevated immune response in bone marrow, suppressing bone growth rate (P < 0.05) and increasing bone resorption (P < 0.05) which led to lower bone mineral density (P < 0.05) and mineral content (P < 0.05) under Eimeria infection. With the same amount of feed intake, the uninfected pair-fed group showed a distinguished bone formation rate and bone resorption level compared with the Eimeria infected groups. In conclusion, inflammatory immune response and oxidative stress in broilers after Eimeria infection were closely associated with altered bone homeostasis, highlighting the role of inflammation and oxidative stress in broiler bone homeostasis during coccidiosis.

Bovine hydroxyapatite-based scaffold accelerated the inflammatory phase and bone growth in rats with bone defect.

Hydroxyapatite (HA) is a biomaterial widely used to treat bone defect, such as due to traffic accident. The HA scaffold is obtained from synthetic HA or natural sources, such as bovine hydroxyapatite (BHA). This study aims to compare the characteristics and in vivo performance of BHA-based and HA-based scaffolds. For this purpose, the scaffold was formulated with gelatin (GEL) and characterised by SEM-EDX, FTIR and mini autograph. The defect model was carried out on the femur area of Wistar rats classified into three animal groups: defect, HA-GEL and BHA-GEL. Postoperatively (7, 14 and 28 days), the bone was radiologically evaluated, and stained with haematoxylin-eosin, anti-CD80 and anti-CD163. The BHA-GEL scaffold showed a regular surface and spherical particle shape, whereas the HA-GEL scaffold exhibited irregular surface. The BHA-GEL scaffold had higher pore size and compressive strength and lower calcium-to-phosphorus ratio than the HA-GEL scaffold. In vivo study showed that the expression of CD80 in the three experimental groups was not significantly different. However, the expression of CD163 differed significantly between the groups. The BHA-GEL group showed robust expression of CD163 on day 7, which rapidly decreased over time. It also showed increased osteoclasts, osteoblasts and osteocytes cell count that contributed to the integrity of the defect area. In conclusion, the BHA-based scaffold exhibited the desired physical and chemical characteristics that benefit in vivo performance versus the HA-based scaffold. Thus, the BHA-based scaffold may be used as a bone graft.

Local growth patterns in tibia associate with restricted external fundamental system in Cervus elaphus. Implications for life history strategies in fossil groups

ABSTRACT The external fundamental system (EFS) is a band of slow-growing tissue, deposited in the periphery of the bone cortex of some tetrapod limb bones as a result of low bone growth rates. This structure has been commonly used as an indicator of maturity attainment, allowing researchers to infer life history traits (e.g. age at maturity, growth rates) in both fossil and extant taxa. However, some studies have recognised the absence of the EFS in the tibia of some vertebrate groups, thus raising concerns about the validity of this bone to reconstruct individual life history. This work analyses and describes for the first time the presence of the external fundamental system (EFS) in the tibia of red deer. Results show that the EFS seems to be strongly conditioned by local growth patterns, as its local deposition indicates. Finally, this study highlights the importance of tibia investigations to expand data of bone microstructure in Cervidae and illustrates that research on extant taxa are essential for deciphering growth dynamics and life history strategies of fossil organisms.

Physicochemical degradation of calcium magnesium phosphate (stanfieldite) based bone replacement materials and the effect on their cytocompatibility

Regenerative bone implants should be completely replaced by new bone within a period of time corresponding to the growth rate of native bone. To meet this requirement, suitable biomaterials must be biodegradable and promote osteogenesis. The combination of slowly degrading but osteoconductive calcium phosphates (CPs) with rapidly degrading and mechanically more resilient magnesium phosphates represents a promising material class for this purpose. In order to create the best possible conditions for optimal implant integration, microporous calcium magnesium phosphate (CMP) cements were processed using 3D powder printing. This technique enables the production of a defect-adapted implant with an optimal fit and a high degree of open porosity to promote bone ingrowth. Four different compositions of 3D printed CMP ceramics were investigated with regard to essential properties of bone implants, including chemical composition, porosity, microstructure, mechanical strength, and cytocompatibility. The ceramics consisted of farringtonite (Mg3(PO4)2) and stanfieldite (Ca4Mg5(PO4)6), with either struvite (NH4MgPO4·6H2O) or newberyite (MgHPO4·3H2O) and brushite (CaHPO4·2H2O) as additional phases. The CMP materials showed open porosities between 13 and 28% and compressive strengths between 11 and 17 MPa, which was significantly higher, as compared with clinically established CP. The cytocompatibility was evaluated with the human fetal osteoblast cell line hFOB 1.19 and was proven to be equal or to even exceed that of tricalcium phosphate. Furthermore, a release of 4–8 mg magnesium and phosphate ions per mg scaffold material could be determined for CMPs over a period of 21 d. In the case of struvite containing CMPs the chemical dissolution of the cement matrix was combined with a physical degradation, which resulted in a mass loss of up to 3.1 wt%. In addition to its beneficial physical and biological properties, the proven continuous chemical degradation and bioactivity in the form of CP precipitation indicate an enhanced bone regeneration potential of CMPs.

Creating morphological diversity in reptilian temporal skull region: A review of potential developmental mechanisms.

Reptilian skull morphology is highly diverse and broadly categorized into three categories based on the number and position of the temporal fenestrations: anapsid, synapsid, and diapsid. According to recent phylogenetic analysis, temporal fenestrations evolved twice independently in amniotes, once in Synapsida and once in Diapsida. Although functional aspects underlying the evolution of tetrapod temporal fenestrations have been well investigated, few studies have investigated the developmental mechanisms responsible for differences in the pattern of temporal skull region. To determine what these mechanisms might be, we first examined how the five temporal bones develop by comparing embryonic cranial osteogenesis between representative extant reptilian species. The pattern of temporal skull region may depend on differences in temporal bone growth rate and growth direction during ontogeny. Next, we compared the histogenesis patterns and the expression of two key osteogenic genes, Runx2 and Msx2, in the temporal region of the representative reptilian embryos. Our comparative analyses suggest that the embryonic histological condition of the domain where temporal fenestrations would form predicts temporal skull morphology in adults and regulatory modifications of Runx2 and Msx2 expression in osteogenic mesenchymal precursor cells are likely involved in generating morphological diversity in the temporal skull region of reptiles.

Microstructure and Mechanical Properties of Hot-Extruded Mg-Zn-Ga-(Y) Biodegradable Alloys.

Magnesium alloys are attractive candidates for use as temporary fixation devices in osteosynthesis because they have a density and Young’s modulus similar to those of cortical bone. One of the main requirements for biodegradable implants is its substitution by tissues during the healing process. In this article, the Mg–Zn–Ga–(Y) alloys were investigated that potentially can increase the bone growth rate by release of Ga ions during the degradation process. Previously, the effectiveness of Ga ions on bone tissue regeneration has been proved by clinical tests. This work is the first systematic study on the microstructure and mechanical properties of Mg–Zn–Y alloys containing Ga as an additional major alloying element prepared by the hot-extrusion process. The microstructure and phase composition of the Mg–Zn–Ga–(Y) alloys in as-cast, heat-treated, and extruded conditions were analyzed. In addition, it was shown that the use of hot extrusion produces Mg–Zn–Ga–(Y) alloys with favorable mechanical properties. The tensile yield strength, ultimate tensile strength, and elongation at fracture of the MgZn4Ga4 alloy extruded at 150 °C were 256 MPa, 343 MPa, and 14.2%, respectively. Overall, MgZn4Ga4 alloy is a perspective for applications in implants for osteosynthesis with improved bone regeneration ability.

Effect of Vitamin D Combined with Recombinant Human Growth Hormone in Children with Growth Hormone Deficiency.

Objective Growth hormone deficiency (GHD) refers to the complete or partial lack of pituitary growth hormone synthesis and secretion. This study is aimed at investigating the efficacy of vitamin D and recombinant human growth hormone (rhGH) in children with GHD. Methods A total of 100 children with GHD at our hospital were included between 1st January 2018 and 31st October 2020. The patients were divided into a study group (n = 70, received vitamin D combined with rhGH) and a control group (n = 30, received rhGH). The growth and development (bone age, growth rate, and height), bone metabolism (bone alkaline phosphatase (BAP), β-collagen degradation product (β-CTX), osteocalcin (OC), and amino-terminal propeptide type I procollagen (PINP)), insulin-like growth factor 1 (IGF-1), ghrelin, and adverse reactions in the two groups were measured before and 12 months after treatment. Results There were no significant differences in the bone age, growth rate, and height between the two groups before treatment. After 12 months of treatment, the bone age, growth rate, and height of the study group were significantly higher than those of the control group. After 12 months of treatment, the levels of serum BAP, PINP, and OC in the study group were significantly higher than those in the control group, while the levels of β-CTX in the study group were significantly lower than those in the control group. The serum IGF-1 level in the study group was significantly higher than that in the control group, while the ghrelin level in the study group was lower. There was no significant difference in the incidence of adverse reactions between the two groups. Conclusion Combined rhGH and vitamin D treatment can promote growth and development, improve bone metabolism, and regulate IGF-1 and ghrelin levels.

Biomechanical analysis of the impact of increasing levels of body mass index on the ability of a bracing orthosis to alter the asymmetric compressive growth plate loading in a scoliotic spine

BackgroundThe impact of increasing body mass index (BMI) on the magnitude of alterations in the asymmetric compressive vertebral growth plate loading of a scoliotic spine following 50% in-brace correction is studied using the finite element method, and subsequent alteration of the longitudinal bone growth rate is quantified. MethodsUpper body weight loading corresponding to a single patient spine geometry representing 4 BMI classifications – overweight (BMI = 25 kg/m2), and class-1, -2, and -3 obesity (BMI – 30 kg/m2, 35 kg/m2, and 40 kg/m2, respectively) – is applied to a three-dimensional finite element model (FEM) of the human thoracolumbosacral spine. The FEM represents a Lenke 1AN scoliotic curve type with 30-degree Cobb angle and 10-degree apical vertebral rotation. Bracing simulation is performed until 50% in-brace correction is achieved. Changes in bending moment at each motion segment and on each growth plate after bracing is simulated and compared between each BMI level. FindingsAs BMI increases, the average magnitude of change in bending moment on each growth plate following bracing decreases. For BMIs 30 kg/m2, 35 kg/m2, and 40 kg/m2, the average change in bending moment on each vertebral growth plate following 50% in-brace correction is 31% smaller (P = .00006), 60% smaller (P = .00007), and 96% smaller (P = .00006), respectively, than for BMI 25 kg/m2. InterpretationsResults indicate that BMI significantly impacts the ability of a bracing orthosis to alter the asymmetric compressive growth plate loading in a scoliotic spine, which is the design function of bracing. This suggests that increasing BMI may significantly impact the ability of a bracing orthosis to halt curve progression in a scoliotic patient.

Laying hens under smallholder conditions: laying performance, growth and bone quality of tibia and femur including essential elements

The study aimed to assess laying performance, growth rate, and bone quality properties of tibia and femur bones of various genotypes of laying hens, including determining essential element composition at the end of the laying cycle in smallholder conditions. The study included three genotypes of laying hens; Czech golden spotted (CGS), White Leghorn (LE) and Dominant Partridge D300 (D300) hens. In total, 180 hens (60/genotype) were used in 3 replications (20 hens/replication). The eggs were collected to determine egg lay and hen-day egg production. Additionally, feed consumption was recorded to determine feed consumption per day or egg, resp. The mortality rate was recorded. Hens were individually weighed every 10 wk to analyze the growth performance and body weight changes during the laying cycle. The differences in performance characteristics were observed as significant in all studied parameters. The bone quality analysis consisted of the determination of bone weight, length, width, and fracture toughness. Furthermore, dry matter, ash, and selected elements, which included boron (B), calcium (Ca), cadmium (Cd), copper (Cu), iron (Fe), magnesium (Mg), manganese (Mn), sodium (Na), phosphorus (P), lead (Pb), and zinc (Zn) were assessed. Regarding the results of tibia and femur bones, the effect of genotype was determined as significant in all evaluated properties. In terms of element composition, all evaluated elements significantly differed among the genotypes in the tibia (with one exception of Cu) and in the femur (with one exception of Cd). In conclusion, our results showed that hens’ performance, production quality, mortality and bone properties significantly differed among genotypes under smallholder conditions. Thus, every genotype needs to be carefully considered, when the rearing conditions are set.