Changes In Cortical Bone Research Articles

STRUCTURAL CHANGES IN CORTICAL BONE AFTER BOMBARDMENT WITH LOW-ENERGY HYDROGEN IONS

Radiobiological studies focused mainly on tracking the effects of photons (X and gamma rays) and high-energy charged particles over low energy ions, which raises interest in studying their biological effects. Therefore, the aim of this study is to investigate the interaction of low-energy hydrogen ions beam with xcortical bovine bone as a biological model. A hydrogen ions beam was used to bombard cortical bone with different fluences; 45, 70 and [Formula: see text][Formula: see text]ions/cm2 at low energy of 5[Formula: see text]keV. The interaction of hydrogen ions with cortical bone was estimated theoretically by the SRIM/TRIM code. The obtained results showed that the average distribution range and the maximum depth for 5[Formula: see text]keV hydrogen ions are 91 and 150[Formula: see text]nm respectively. The energy losses from incident ions are 4.45[Formula: see text]keV for ionization, 170[Formula: see text]eV for phonons and 18[Formula: see text]eV for vacancies. Also, the energy losses from the recoil atoms are 119[Formula: see text]eV for ionization, 234[Formula: see text]eV for phonons and 8[Formula: see text]eV for vacancies. At the same time, the effect of low-energy hydrogen ions bombardment on the structure of bone was studied by X-ray diffraction (XRD) and FTIR.

Evaluation of antihypertensive drug-induced changes in mandibular bone using fractal analysis

ObjectivesThe aim was to evaluate changes in trabecular and cortical mandibular bone caused by antihypertensive (AHT) drugs through fractal analysis. MethodsThis retrospective study included 230 patients who were taking AHT medication and had no conditions affecting bone metabolism other than hypertension. A control group of 230 healthy, sex-matched individuals was also included. Patients were divided into subgroups according to AHT drugs: thiazide diuretics (TDs), beta-blockers (BBs), angiotensin-converting enzyme inhibitors (ACEIs), angiotensin receptor blockers (ARBs), calcium channel blockers (CCBs), and a combination of drugs. The fractal dimension (FD) was calculated bilaterally in 5 regions of interest (ROI 1 – ROI 5) including 4 trabecular regions and 1 cortical region using Image J software. ResultsMean FD values were significantly higher in all ROIs for the study group compared to the control group (P<0.001). FDs were significantlty higher for BB, ACEI, ARB, CCB, and combined subgroups compared to controls in ROIs 1, 2, and 4; for ACEI and CCB subgroups compared to controls in ROI 3; and for TD, BB, ACEI, ARB, CCB, and combined subgroups compared to controls in ROI 5 (P<0.001). ConclusionAHTs may increase FD values of the trabecular and cortical structures. Assessment of the effects of AHT drugs is essential for predicting the prognosis for bone healing after tooth extraction, osseointegration after implant surgery or other surgical procedures.

Contact states with femoral cortical bone and periprosthetic bone mineral density changes differ between traditional and newly introduced fully hydroxyapatite-coated stems.

The aim of this study was to compare the pattern of initial fixation and changes in periprosthetic bone mineral density (BMD) between patients who underwent total hip arthroplasty (THA) using a traditional fully hydroxyapatite (HA)-coated stem (T-HA group) and those with a newly introduced fully HA-coated stem (N-HA group). The study included 36 patients with T-HA stems and 30 with N-HA stems. Dual-energy X-ray absorptiometry was used to measure the change in periprosthetic BMD, one and two years postoperatively. The 3D contact between the stem and femoral cortical bone was evaluated using a density-mapping system, and clinical assessment, including patient-reported outcome measurements, was recorded. There were significantly larger contact areas in Gruen zones 3, 5, and 6 in the N-HA group than in the T-HA group. At two years postoperatively, there was a significant decrease in BMD around the proximal-medial femur (zone 6) in the N-HA group and a significant increase in the T-HA group. BMD changes in both groups correlated with BMI or preoperative lumbar BMD rather than with the extent of contact with the femoral cortical bone. The N-HA-coated stem showed a significantly larger contact area, indicating a distal fixation pattern, compared with the traditional fully HA-coated stem. The T-HA-coated stem showed better preservation of periprosthetic BMD, two years postoperatively. Surgeons should consider these patterns of fixation and differences in BMD when selecting fully HA-coated stems for THA, to improve the long-term outcomes.

Population trends in human rib cross-sectional shapes.

Rib fractures remain the most frequent thoracic injury in motor vehicle crashes. Computational human body models (HBMs) can be used to simulate these injuries and design mitigation strategies, but they require adequately detailed geometry to replicate such fractures. Due to a lack of rib cross-sectional shape data availability, most commercial HBMs use highly simplified rib sections extracted from a single individual during original HBM development. This study provides human rib shape data collected from chest CT scans of 240 females and males across the full adult age range. A cortical bone mapping algorithm extracted cross-sectional geometry from scans in terms of local periosteal position with respect to the central rib axis and local cortex thickness. Principal component analysis was used to reduce the dimensionality of these cross-sectional shape data. Linear regression found significant associations between principal component scores and subject demographics (sex, age, height, and weight) at all rib levels, and predicted scores were used to explore the expected rib cross-sectional shapes across a wide range of subject demographics. The resulting detailed rib cross-sectional shapes were quantified in terms of their total cross-sectional area and their cortical bone cross-sectional area. Average-sized female ribs were smaller in total cross-sectional area than average-sized male ribs by between 20% and 36% across the rib cage, with the greatest differences seen in the central portions of rib 6. This trend persisted although to smaller differences of 14%-29% when comparing females and males of equal intermediate weight and stature. Cortical bone cross-sectional areas were up to 18% smaller in females than males of equivalent height and weight but also reached parity in certain regions of the rib cage. Increased age from 25 to 80 years was associated with reductions in cortical bone cross-sectional area (up to 37% in females and 26% in males at mid-rib levels). Total cross-sectional area was also seen to reduce with age in females but to a lesser degree (of up to 17% in mid-rib regions). Similar regions saw marginal increases in total cross-sectional area for male ribs, indicating age affects rib cortex thickness moreso than overall rib cross-sectional size. Increased subject height was associated with increased rib total and cortical bone cross-sectional areas by approximately 25% and 15% increases, respectively, in mid-rib sections for a given 30 cm increase in height, although the magnitudes of these associations varied by sex and rib location. Increased weight was associated with approximately equal changes in both cortical bone and total cross-sectional areas in males. These effects were most prominent (around 25% increases for an addition of 50 kg) toward lower ribs in the rib cage and had only modest effects (less than 12% change) in ribs 2-4. Females saw greater increases with weight in total rib area compared to cortical bone area, of up to 21% at the eighth rib level. Results from this study show the expected shapes of rib cross-sections across the adult rib cage and across a broad range of demographics. This detailed geometry can be used to produce accurate rib models representing widely varying populations.

Mandibular Cortical Bone Evaluation in a Healthy Paediatric Population.

Changes in mandibular cortical bone have been documented in children with chronic diseases but not in healthy populations. We aimed to qualitatively and quantitatively evaluate the mandibular cortical bone of a healthy paediatric population using dental panoramic radiographs (DPTs). The secondary objective was to assess the effect of dental status on cortical bone. The DPTs of 660 individuals, aged 6-18 years, were evaluated by two blinded examiners. Bone was qualitatively categorized according to the Mandibular Cortical Index (MCI), and its width was calculated using the Mandibular Cortical Width Index (MCW). Differences between gender and age were tested using Fisher's exact and correlation with dental status with the chi-square test. A significant correlation was observed between bone morphology and gender, with girls having more frequent even and sharp endosteal margins than boys, who showed semilunar defects. The degree of erosion increased with age, as did bone thickness. A positive correlation between thickness and type of dentition was recorded, with normal bone predominating in children in the mixed dentition stage. Νο correlation was found between bone morphology or thickness and the factors associated with dental status. Bone quality and quantity vary significantly between different genders and age groups. Dental needs and treatment characteristics did not seem to affect the above parameters.

Treatment of osteoporosis using a selective androgen receptor modulator ostarine in an orchiectomized rat model

PurposeThe selective androgen receptor modulator ostarine has been shown to have advantageous effects on skeletal tissue properties, reducing muscle wasting and improving physical function in males. However, data on effects in male osteoporosis remain limited. In this study, the effects of ostarine on osteoporotic bone were evaluated in a rat model of male osteoporosis and compared with those of testosterone treatments.MethodsEight-month-old male Sprague-Dawley rats were either non-orchiectomized to serve as a healthy control (Non-Orx, Group 1) or orchiectomized (Orx, Groups 2–6) and then grouped (n = 15/group): (1) Non-Orx, (2) Orx, (3) Ostarine Therapy, (4) Testosterone Therapy, (5) Ostarine Prophylaxis and (6) Testosterone Prophylaxis. Prophylaxis treatments started directly after orchiectomy and continued for 18 weeks, whereas Therapy treatments were initiated 12 weeks after Orx. Ostarine and Testosterone were applied orally at daily doses of 0.4 and 50 mg/kg body weight, respectively. The lumbar vertebral bodies and femora were analyzed using biomechanical, micro-CT, ashing, and gene expression analyses.ResultsOstarine Prophylaxis showed positive effects in preventing osteoporotic changes in cortical and trabecular bone (femoral trabecular density: 26.01 ± 9.1% vs. 20.75 ± 1.2% in Orx and in L4: 16.3 ± 7.3% vs 11.8 ± 2.9% in Orx); biomechanical parameters were not affected; prostate weight was increased (0.62 ± 0.13 g vs 0.18 ± 0.07 g in Orx). Ostarine Therapy increased solely the cortical density of the femur (1.25 ± 0.03 g/cm3 vs. 1.18 ± 0.04 g/cm3 in Orx); other bone parameters remained unaffected. Testosteron Prophylaxis positively influenced cortical density in femur (1.24 ± 0.05 g/cm3 vs. 1.18 ± 0.04 g/cm3 in Orx); Test. Therapy did not change any bony parameters.ConclusionOstarine Prophylaxis could be further investigated as a preventative treatment for male osteoporosis, but an androgenic effect on the prostate should be taken into consideration, and combination therapies with other anti-osteoporosis agents could be considered.

Abaloparatide prevents immobilization-induced cortical but not trabecular bone loss after spinal cord injury.

Spinal cord injury (SCI) causes severe and resistant sublesional disuse bone loss. Abaloparatide, a modified parathyroid hormone related peptide, is an FDA approved drug for treatment of severe osteoporosis with potent anabolic activity. The effects of abaloparatide on SCI-induced bone loss remain undefined. Thus, female mice underwent sham or severe contusion thoracic SCI causing hindlimb paralysis. Mice then received subcutaneous injection of vehicle or 20 μg/kg/day abaloparatide for 35 days. Micro-computed tomography (micro-CT) analysis of the distal and midshaft femoral regions of the SCI-vehicle mice revealed reduced trabecular fractional bone volume (56%), thickness (75%), and cortical thickness (80%) compared to sham-vehicle controls. Treatment with abaloparatide did not prevent SCI-induced changes in trabecular or cortical bone. However, histomorphometry evaluation of the SCI-abaloparatide mice demonstrated that abaloparatide treatment increased osteoblast (241%) and osteoclast (247%) numbers and the mineral apposition rate (131%) compared to SCI-vehicle animals. In another independent experiment, treatment with 80 μg/kg/day abaloparatide significantly attenuated SCI-induced loss in cortical bone thickness (93%) when compared to SCI-vehicle mice (79%) but did not prevent SCI-induced trabecular bone loss or elevation in cortical porosity. Biochemical analysis of the bone marrow supernatants of the femurs showed that SCI-abaloparatide animals had 2.3-fold increase in procollagen type I N-terminal propeptide, a bone formation marker than SCI-vehicle animals. SCI groups had 70% higher levels of cross-linked C-telopeptide of type I collagen, a bone resorption marker, than sham-vehicle mice. These findings suggest that abaloparatide protects the cortical bone against the deleterious effects of SCI by promoting bone formation.

A support vector machine-based algorithm to identify bisphosphonate-related osteonecrosis throughout the mandibular bone by using cone beam computerized tomography images.

This study aimed to develop an algorithm to distinguish the patients with bisphosphonate-related osteonecrosis of the jaws (BRONJ) from healthy controls using CBCT images by evaluating both trabecular and cortical bone changes through the whole body of the mandibular bone. Patient data set was created from axial CBCT images of 7 BRONJ patients (28 slices) and 8 healthy controls (27 slices). The healthy bone of healthy controls, bone sclerosis of BRONJ patients, bone necrosis of BRONJ patients, and normal appearing bone of BRONJ patients (NBP) were labeled on CBCT images by three maxillofacial radiologists. Proposed algorithm had preparation and background cancellation, mandibular bone segmentation and centerline determination, spatial transformation of gray values, and classification steps. Significant differences between the statistical moments (mean, variance, skewness, kurtosis, standard error, median, mode and coefficient of variance) of healthy and diseased (bone sclerosis and necrosis) groups were observed (p = 0.000, p < 0.05). Also, variations were noted between healthy controls and NBP of BRONJ patients (p = 0.000, p < 0.05).The statistical moments were utilized to develop the algorithm which has resulted with accuracy of 0.999, sensitivity of 0.998, specificity of 0.998, precision of 1, recall of 0.998, AUC of 1, and F1 score of 0.999 in identification of BRONJ patients from healthy ones. The proposed algorithm differentiated the mandibular bones of the healthy and the BRONJ patients with high accuracy in the present test sample.

Evaluation of cortical bone density using clinical computed tomography images: Detection of cortical porosity areas or transitional zones in human femoral diaphyses.

Age-related changes in human trabecular bone and cortical bone are known to vary. Although the porosity of cortical bone has been suggested to increase the risk of bone fracture, most of the currently available instruments for osteoporosis testing target trabecular bone. In this study, we evaluated cortical bone density using clinical computed tomography (CT) and compared the reliability of the cortical bone density index (CDI) with that of a polished male femoral bone from the same region. CDI images revealed that the porous area of cortical bone was extended in low CDI values. Moreover, this method was used to semi-quantitatively evaluate the cortical bones of the diaphysis of male femur specimens (n=46). We found that there was a significant relationship (r=0.70, p < 0.01) between the value of the cortical index (the ratio of cortical bone area to the cross-sectional area of the femoral diaphysis) and the average of CDI in the low signal area. Our findings suggest that the smaller the cortical bone occupancy, the more areas of consequential bone density loss were present. This may be the first step toward using clinical CT to assess cortical bone density.

Rubber Dam Clamp May Cause Cortical Necrosis: A Case Report

Tooth isolation methods used during endodontic procedures are necessary to create an aseptic field and protect the patient’s alimentary tract from irrigation and instrument insult. This case details changes that can occur in mandibular cortical bone architecture after the use of a stainless steel rubber dam clamp during an endodontic procedure. A 22-year-old, otherwise healthy woman underwent nonsurgical root canal therapy on tooth #31 (mandibular right second molar, symptomatic irreversible pulpitis and periapical periodontitis.) Cone-beam computed tomographic imaging obtained between treatments revealed irregular erosive and lytic changes of the crestal-lingual cortical bone, resulting in sequestrum formation with infection and exfoliation. Continued monitoring and 6-month post-treatment CBCT imaging revealed complete resolution without further intervention. When a stainless steel rubber dam clamp is placed onto gingiva overlying mandibular alveolar bone, bony changes can occur presenting with radiographic signs of cortical erosion and may result in necrosis of the cortical bone with sequestrum formation. Knowledge of this potential outcome improves our understanding of the normal course progression after dental procedures using a rubber dam clamp for tooth isolation.

The alteration of advanced glycation end products and its potential role on bone loss under microgravity

Bone loss occurs in astronauts during long-term space flight, and hardly recover to the normal level after back to the earth. This is because the mechanism of microgravity-induced osteoporosis is still unclear. Advanced glycation end products (AGEs) are formed between reducing sugars and long-lived proteins and are verified to be the pathogenic mechanism for diabetic and aging osteoporosis. These non-enzymatic glycation products are considered to have adverse effects on bone metabolism and bone quality which consist of bone microstructure and bone organic matrix. However, whether AGEs accumulation happened under microgravity is not clear yet. AGEs accumulation can be induced by hyperglycemia in diabetic patients and senior people. Hyperglycemia was also found to occur in astronauts during spaceflight or under simulated microgravity, however, whether it also can cause bone matrix AGEs accumulation remains unrevealed, and whether AGEs involve in the disuse osteoporosis is as well not clear yet. Therefore, in this study, we explored the AGEs changes and genesis, together with its potential relationship with disuse osteoporosis under simulated microgravity by using a rat tail-suspended model. Sixteen 8-week-old female Sprague-Dawley rats were randomly distributed into control (CON) and tail-suspension (TS) groups. After 21-days of an experiment, fluorescent total AGEs and pentosidine in bone matrix were separately detected by fluorescence microscope and High Performance Liquid Chromatography (HPLC); soluble AGEs and glucose-related biomarkers in serum were detected by ELISA; bone microstructure was evaluated by Micro-CT, and mRNA expression of bone metabolism biomarkers (OCN, ALP, RANKL/OPG) in bone was determined by QPCR. Results showed that after tail-suspension AGEs fluorescent intensity and PEN content increased in trabecular bone while no significant changes in cortical bone; serum glucose increased and was positively correlated with bone matrix AGEs; trabecular bone microstructure was deteriorated, ALP and OCN mRNA expression decreased while RANKL/OPG mRNA expression increased, and all of them showed correlations with bone matrix AGEs. The results suggested under simulated microgravity, bone matrix AGEs accumulation may be attributed to the elevated serum glucose, and preferred to occur in trabecular bone first. AGEs accumulation in bone matrix accompanied negative effects on trabecular bone microstructure and bone metabolism activities under simulated microgravity, suggesting AGEs accumulation may be a culprit in disused bone loss.

Aging and Bone Metabolism.

Changes in bone architecture and metabolism with aging increase the likelihood of osteoporosis and fracture. Age-onset osteoporosis is multifactorial, with contributory extrinsic and intrinsic factors including certain medical problems, specific prescription drugs, estrogen loss, secondary hyperparathyroidism, microenvironmental and cellular alterations in bone tissue, and mechanical unloading or immobilization. At the histological level, there are changes in trabecular and cortical bone as well as marrow cellularity, lineage switching of mesenchymal stem cells to an adipogenic fate, inadequate transduction of signals during skeletal loading, and predisposition toward senescent cell accumulation with production of a senescence-associated secretory phenotype. Cumulatively, these changes result in bone remodeling abnormalities that over time cause net bone loss typically seen in older adults. Age-related osteoporosis is a geriatric syndrome due to the multiple etiologies that converge upon the skeleton to produce the ultimate phenotypic changes that manifest as bone fragility. Bone tissue is dynamic but with tendencies toward poor osteoblastic bone formation and relative osteoclastic bone resorption with aging. Interactions with other aging physiologic systems, such as muscle, may also confer detrimental effects on the aging skeleton. Conversely, individuals who maintain their BMD experience a lower risk of fractures, disability, and mortality, suggesting that this phenotype may be a marker of successful aging. © 2023 American Physiological Society. Compr Physiol 13:4355-4386, 2023.

Histological assessment of cortical bone changes in diabetic rats

BackgroundDiabetes mellitus weakens bone strength due to deterioration of bone quality; however, the histological mechanisms are still unknown. We hypothesized that histological assessment of cortical bone would enable us to determine the cause of the bone strength reduction associated with diabetes mellitus. Our aim was to evaluate the histomorphometric changes of cortical bone associated with deterioration of intrinsic bone properties and bone quality in diabetes mellitus.MethodsWe compared the outcomes of mechanical tests, bone mineral density measured using micro-computed tomography, and histological assessments, by applying Villanueva’s bone stain, to the tibial bones of 40-week-old diabetic and control male rats.ResultsWith respect to mechanical testing, the maximum load and energy absorption were significantly lower in the diabetic than in the control group, although fracture displacement and stiffness were not significantly different between the two groups. Bone mineral density was significantly higher in the diabetic group than in the control group. Bone histomorphometry revealed that the diabetic rats had fewer osteocytes, greater cortical porosity, and increased mineralization in cortical bone compared with the control group.ConclusionsIncreased mineralization of the cortical bone with greater cortical porosity leads to a weakening of bone strength in diabetes mellitus.

An Improved Method for Assessing Macroscale Diffusion Through Osteonal Bone.

The characterization of diffusion through biological tissues has played an important role in fundamental medical research and product development. Understanding the diffusion phenomena allows for the identification of new concepts in fundamental science, evolving medical knowledge and improving future standards and protocols. To illustrate, the structure of cortical bone changes upon the onset of osteoporosis, altering the limited porous compartment through which nutrients and essential signaling molecules travel to bone cells. Estrogen hormone replacement therapy (HRT) is one of the gold standard treatments to attempt to mitigate the effects that this structural change exerts in menopausal osteoporosis patients; however, HRT effectiveness is often variable in these patients, likely due to variability in bone structure and physiology, and thus transport rates. Scientists have studied diffusion in cortical bone tissue for decades. Current methodological standards include fluorescence recovery after photobleaching and computed tomography finite element analysis. Both techniques limit areas of tissue to microscale (1-100 μm2) analysis-only examining a few osteocytes within the structure at a time-and adopt assumptions that oversimplify in vivo tissue structure and transport phenomena. Also, the range of diffusion tracers is limited by the sensitivities of the analytical equipment, typically requiring tracer concentrations in the micromolar range. Herein is described a novel device for directly assessing the diffusion coefficient of 3H-estradiol at 37°C in macroscale osteonal bone specimens (1.4 cm2)-assessing a much larger portion of the total tissue than previously reported-while using radioisotope tracers for much higher sensitivity, thus achieving physiologically relevant estradiol concentrations. The current diffusion chamber device represents a cost-effective and validated method to mitigate these shortcomings. The device provides long-term diffusion data through macroscale (greater than 1 mm2) tissue areas, presenting a more physiologically accurate way to assess cortical bone diffusion. The device can assess solute diffusion through other tissues or materials and may easily be scaled up to run multiple diffusion experiments simultaneously. Impact statement The diffusion chamber device represents a cost-effective and validated method to assess solute diffusion through solid materials. Specifically, it demonstrates that this novel device provides long-term diffusion data through macroscale tissue samples at nanomolar concentrations, presenting a precise way to address the effects of tissue structures on diffusion. This device can be applied to other tissues or engineered materials, offering a methodology that is easily scaled up to allow simultaneous assessment of multiple material samples.

Radiographic changes of mandibular cortical bone in bisphosphonate drug holiday.

ObjectivesThere have been few studies to date on the residual effect of bisphosphonate. This study investigated the radiographic changes of mandibular cortical thickness upon bisphosphonate drug holiday.Materials and MethodsThis retrospective study includes 36 patients diagnosed with MRONJ (medication-related osteonecrosis of the jaw) at Ajou University Dental Hospital in 2010-2021. All patients stopped taking bisphosphonate under consultation with the prescribing physicians. Panoramic radiographs were taken at the start of discontinuation (T0), 12 months after (T1), and 18 months after (T2) discontinuation of bisphosphonate, respectively. Mental index and panoramic mandibular index were calculated using Ledgerton’s method. Paired t-tests were used to analyze differences over time.ResultsThe difference in indices (mental index and panoramic mandibular index) between T0 and T1 was not statistically significant (paired t-test, P>0.05). However, the difference in these indices between T1 and T2 was statistically significant (paired t-test, P<0.05).ConclusionThe cortical thickness of the mandible decreased in the late stage (after 18 months) as observed by panoramic radiograph.

Polg mtDNA mutator mice reveal limited involvement of vertebral bone loss in premature aging-related thoracolumbar hyperkyphosis

BackgroundAge-related hyperkyphosis is multifactorial and involves alterations of vertebral bone, intervertebral discs (IVD) and paraspinal muscles. The relative contribution of these tissues remains unclear. Here, we compared differences in vertebral bone microarchitecture and IVD thickness between prematurely aging mice with spinal hyperkyphosis and wild type littermates. MethodsThoracolumbar vertebral columns were dissected from homozygous PolgD257A and age-matched wild type littermates. Micro-computed tomography was performed to quantify cortical and trabecular bone parameters at anterior and posterior portions of T8-L4 vertebrae. In addition, vertebral shape, transaxial facet joint orientation and IVD thickness were quantified. Differences in anterior/posterior ratios between genotypes were compared by Student's t-test and association between vertebral bone and IVD parameters was investigated using Pearson correlation analysis. ResultsHyperkyphotic homozygous mice displayed generalized osteopenia that was more pronounced at the posterior compared with anterior portion of thoracolumbar vertebrae. An increase in the anterior/posterior ratio of trabecular bone parameters was revealed at the thoracolumbar junction (T13-L1). PolgD257A displayed diffuse loss of cortical bone thickness, yet anterior/posterior ratios were unchanged. Despite generalized and regional bone loss, vertebral shape was unaffected. PolGD257A mice showed a 10–20 % reduction of IVD thickness at both thoracic and lumbar levels, with only minimal histopathological changes. IVD thickness was negatively correlated with anterior/posterior ratios of trabecular bone parameters, as well as with more coronally oriented facet joints, but negatively correlated with the anterior/posterior ratio of cortical bone thickness. ConclusionsAging-induced regional changes of vertebral trabecular and cortical bone did not lead to altered vertebral shape in PolgD257A mice but may indirectly cause hyperkyphosis through reduction of IVD thickness. These findings suggest a limited role for aging-induced bone loss in spinal hyperkyphosis and warrants further research on the involvement of paraspinal muscle degeneration.

GsαR201C and estrogen reveal different subsets of bone marrow adiponectin expressing osteogenic cells

The Gsα/cAMP signaling pathway mediates the effect of a variety of hormones and factors that regulate the homeostasis of the post-natal skeleton. Hence, the dysregulated activity of Gsα due to gain-of-function mutations (R201C/R201H) results in severe architectural and functional derangements of the entire bone/bone marrow organ. While the consequences of gain-of-function mutations of Gsα have been extensively investigated in osteoblasts and in bone marrow osteoprogenitor cells at various differentiation stages, their effect in adipogenically-committed bone marrow stromal cells has remained unaddressed. We generated a mouse model with expression of GsαR201C driven by the Adiponectin (Adq) promoter. Adq-GsαR201C mice developed a complex combination of metaphyseal, diaphyseal and cortical bone changes. In the metaphysis, GsαR201C caused an early phase of bone resorption followed by bone deposition. Metaphyseal bone formation was sustained by cells that were traced by Adq-Cre and eventually resulted in a high trabecular bone mass phenotype. In the diaphysis, GsαR201C, in combination with estrogen, triggered the osteogenic activity of Adq-Cre-targeted perivascular bone marrow stromal cells leading to intramedullary bone formation. Finally, consistent with the previously unnoticed presence of Adq-Cre-marked pericytes in intraosseous blood vessels, GsαR201C caused the development of a lytic phenotype that affected both cortical (increased porosity) and trabecular (tunneling resorption) bone. These results provide the first evidence that the Adq-cell network in the skeleton not only regulates bone resorption but also contributes to bone formation, and that the Gsα/cAMP pathway is a major modulator of both functions.

Long Bone Mineral Loss, Bone Microstructural Changes and Oxidative Stress After Eimeria Challenge in Broilers.

The objective of this study was to evaluate the impact of coccidiosis on bone quality and antioxidant status in the liver and bone marrow of broiler chickens. A total of 360 13-day old male broilers (Cobb 500) were randomly assigned to different groups (negative control, low, medium-low, medium-high, and highest dose groups) and orally gavaged with different concentrations of Eimeria oocysts solution. Broiler tibia and tibia bone marrow were collected at 6 days post-infection (6 dpi) for bone 3-D structural analyses and the gene expression related to osteogenesis, oxidative stress, and adipogenesis using micro-computed tomography (micro-CT) and real-time qPCR analysis, respectively. Metaphyseal bone mineral density and content were reduced in response to the increase of Eimeria challenge dose, and poor trabecular bone traits were observed in the high inoculation group. However, there were no significant structural changes in metaphyseal cortical bone. Medium-high Eimeria challenge dose significantly increased level of peroxisome proliferator-activated receptor gamma (PPARG, p < 0.05) and decreased levels of bone gamma-carboxyglutamate protein coding gene (BGLAP, p < 0.05) and fatty acid synthase coding gene (FASN, p < 0.05) in bone marrow. An increased mRNA level of superoxide dismutase type 1 (SOD1, p < 0.05) and heme oxygenase 1 (HMOX1, p < 0.05), and increased enzyme activity of superoxide dismutase (SOD, p < 0.05) were found in bone marrow of Eimeria challenged groups compared with that of non-infected control. Similarly, enzyme activity of SOD and the mRNA level of SOD1, HMOX1 and aflatoxin aldehyde reductase (AKE7A2) were increased in the liver of infected broilers (p < 0.05), whereas glutathione (GSH) content was lower in the medium-high challenge group (p < 0.05) compared with non-challenged control. Moreover, the mRNA expression of catalase (CAT) and nuclear factor kappa B1 (NFKB1) showed dose-depend response in the liver, where expression of CAT and NFKB1 was upregulated in the low challenge group but decreased with the higher Eimeria challenge dosage (p < 0.05). In conclusion, high challenge dose of Eimeria infection negatively affected the long bone development. The structural changes of tibia and decreased mineral content were mainly located at the trabecular bone of metaphyseal area. The change of redox and impaired antioxidant status following the Eimeria infection were observed in the liver and bone marrow of broilers.

Three-dimensional nasal forms following unilateral cleft-lip nose correction with mandibular ramus cortical bone augmentation for concaved nasal dorsum

PurposeTo observe the pre- and postoperative three-dimensional (3D) nasal morphologies following mandibular ramus cortical bone augmentation (CBA) for a concaved nasal dorsum in definitive correction of an underdeveloped unilateral cleft lip (UCL) nose. Subjects and MethodsThree Japanese women with complete unilateral cleft lip and palate (UCLP) underwent nose correction using CBA on the flat or concaved nasal dorsum in combination with an extended spreader cartilage graft. The measurement items included the nasal dorsal angle, the nasal tip angle, and the x- and z- axis values of the nasal dorsum ridge and nasal tip points. The results were compared with those of thirteen sex- and age-matched women with complete UCLP who underwent the same nasal correction excluding CBA. Postoperative changes in cortical bone were also observed radiographically. ResultsThe nasal dorsal angle increased and nasal tip angle decreased postoperatively in the patients with CBA, becoming more similar to those of subjects without CBA. Postoperatively, improvement of the lateral nose profile with natural hardness was achieved in three all patients with CBA. 3D analyses of patients with CBA demonstrated an increased height of the nasal dorsum ridge and nasal tip points in the center of the face.Radiological observation revealed remaining transplanted cortical bone, although it became smaller. ConclusionsMandibular ramus cortical bone augmentation may be one of the options for molding up the severely concaved nasal dorsum on definitive correction of an underdeveloped nose in Asian patients with complete UCLP, without damaging other parts of the body.

Mandibular Bone Changes in Children and Adolescents with Type 1 Diabetes Mellitus in Different Metabolic Control States

Objective: The aim of this study is to evaluate the cortical and trabecular mandibular bone morphology of children and adolescents with type 1 diabetes mellitus (DM) and control group utilizing fractal dimension analysis (FDA) and different panoramic radiomorphometric indices through digital panoramic radiographic images (DPRIs). Methods: The study included 57 patients for the type 1 DM group (25 male and 32 female with a mean age of 11.5±2.4 years) and 57 patients for the control group (28 male and 29 female with a mean age of 10.5±2.1 years). The type 1 DM group was divided into the well-controlled, moderately-controlled, and poorly-controlled subgroups based on HbA1c. Mandibular cortical width (MCW) (according to Lengerton et al.) and panoramic mandibular index (PMI) (according to Benson et al.) were measured, mandibular cortical index (MCI) (according to Klemetti et al) and simple visual estimation (SVE) (according to Lee et al.) were evaluated, and FDA was conducted according to White and Rudolph, resulting in three areas of interest (IAs) being obtained in all of the DPRIs. Results: There was no significant difference between type 1 DM group and control according to the mean MCW, mean PMI measurements, MCI and SVE. The mean FD values were not significantly different between type 1 DM group and the control and between type 1 DM subgroups and control. Conclusion: This study revealed no cortical and trabecular bone changes in mandibula in children and adolescents with type 1 DM compared to the control group. In addition, metabolic control states of DM did not affect the bone structure.