scholarly journals Effect of Topical PTH 1-34 Functionalized to Biogran® in the Process of Alveolar Repair in Rats Submitted to Orchiectomy

Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 207
Author(s):  
Paula Buzo Frigério ◽  
Pedro Henrique Silva Gomes-Ferreira ◽  
Fábio Roberto de Souza Batista ◽  
Juliana Moura ◽  
Idelmo Rangel Garcia Júnior ◽  
...  
Keyword(s):  
Local Treatment ◽  
Total Porosity ◽  
Repair Process ◽  
Bone Volume ◽  
Micro Ct ◽  
Volume Number ◽  
Adhesive Protein ◽  
Bone Maintenance ◽  
Trabecular Separation ◽  
Lower Expression

(1) Background: There are many therapies for osteoporosis control and bone maintenance; anabolic drugs such as teriparatide and bone grafts help in the repair process and stimulate bone formation. Thus, the aim of the present study was to evaluate the behavior of repaired bone in the presence of PTH (teriparatide) associated with Biogran® (biomaterial) through a sonochemical procedure after extraction in rats. (2) Methods: The insertion of Biogran® with PTH in the alveolus was performed 30 days after incisor extraction. Euthanasia occurred after 60 days. (3) Results: The use of local treatment of PTH loaded with Biogran® in healthy rats promoted good results for micro-CT, with an increase in percentage and bone volume, number and trabecular separation and less total porosity. Greater immunostaining for Wnt, β-Catenin and osteocalcin proteins and lower expression for Thrombospondin-Related Adhesive Protein (TRAP), which shows an increase in the number of osteoblasts and inhibition of osteoclast action. However, the treated orchiectomized groups did not obtain such expressive results. (4) Conclusion: The use of Biogran® with PTH improved alveolar repair in rats. However, new researches with more efficient doses must be studied to collaborate effectively with the formation of a quality bone after the orchiectomy.

scholarly journals Bone structure determined by HR-MDCT does not correlate with micro-CT of lumbar vertebral biopsies: a prospective cross-sectional human in vivo study

2020 ◽  
Vol 15 (1) ◽  
Author(s):  
Matthias Pumberger ◽  
Ahi Sema Issever ◽  
Torsten Diekhoff ◽  
Christin Schwemmer ◽  
Susanne Berg ◽  
...  
Keyword(s):  
Lumbar Spine ◽  
Bone Structure ◽  
Bone Volume ◽  
Bone Architecture ◽  
Micro Ct ◽  
Cross Sectional ◽  
Trabecular Thickness ◽  
Increased Risk ◽  
Trabecular Separation

Abstract Background Osteoporosis is characterized by a deterioration of bone structure and quantity that leads to an increased risk of fractures. The primary diagnostic tool for the assessment of the bone quality is currently the dual-energy X-ray absorptiometry (DXA), which however only measures bone quantity. High-resolution multidetector computed tomography (HR-MDCT) offers an alternative approach to assess bone structure, but still lacks evidence for its validity in vivo. The objective of this study was to assess the validity of HR-MDCT for the evaluation of bone architecture in the lumbar spine. Methods We conducted a prospective cross-sectional study to compare the results of preoperative lumbar HR-MDCT scans with those from microcomputed tomography (μCT) analysis of transpedicular vertebral body biopsies. For this purpose, we included patients undergoing spinal surgery in our orthopedic department. Each patient underwent preoperative HR-MDCT scanning (L1-L4). Intraoperatively, transpedicular biopsies were obtained from intact vertebrae. Micro-CT analysis of these biopsies was used as a reference method to assess the actual bone architecture. HR-MDCT results were statistically analyzed regarding the correlation with results from μCT. Results Thirty-four patients with a mean age of 69.09 years (± 10.07) were included in the study. There was no significant correlation for any of the parameters (bone volume/total volume, trabecular separation, trabecular thickness) between μCT and HR-MDCT (bone volume/total volume: r = − 0.026 and p = 0.872; trabecular thickness: r = 0.074 and r = 6.42; and trabecular separation: r = − 0.18 and p = 0.254). Conclusion To our knowledge, this is the first study comparing in vivo HR-MDCT with μCT analysis of vertebral biopsies in human patients. Our findings suggest that lumbar HR-MDCT is not valid for the in vivo evaluation of bone architecture in the lumbar spine. New diagnostic tools for the evaluation of osteoporosis and preoperative orthopedic planning are urgently needed.

scholarly journals Micro-Computed Tomography Analysis of Subchondral Bone Regeneration Using Osteochondral Scaffolds in an Ovine Condyle Model

2021 ◽  
Vol 11 (3) ◽  
pp. 891
Author(s):  
Taylor Flaherty ◽  
Maryam Tamaddon ◽  
Chaozong Liu
Keyword(s):  
Computed Tomography ◽  
Bone Regeneration ◽  
Subchondral Bone ◽  
Volume Ratio ◽  
Bone Volume ◽  
Osteochondral Defects ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
Trabecular Thickness ◽  
Osteochondral Scaffold

Osteochondral scaffold technology has emerged as a promising therapy for repairing osteochondral defects. Recent research suggests that seeding osteochondral scaffolds with bone marrow concentrate (BMC) may enhance tissue regeneration. To examine this hypothesis, this study examined subchondral bone regeneration in scaffolds with and without BMC. Ovine stifle condyle models were used for the in vivo study. Two scaffold systems (8 mm diameter and 10 mm thick) with and without BMC were implanted into the femoral condyle, and the tissues were retrieved after six months. The retrieved femoral condyles (with scaffold in) were examined using micro-computed tomography scans (micro-CT), and the micro-CT data were further analysed by ImageJ with respect to trabecular thickness, bone volume to total volume ratio (BV/TV) ratio, and degree of anisotropy of bone. Statistical analysis compared bone regeneration between scaffold groups and sub-set regions. These results were mostly insignificant (p < 0.05), with the exception of bone volume to total volume ratio when comparing scaffold composition and sub-set region. Additional trends in the data were observed. These results suggest that the scaffold composition and addition of BMC did not significantly affect bone regeneration in osteochondral defects after six months. However, this research provides data which may guide the development of future treatments.

Non-Invasive Analysis of the Micro-Structural and Biomechanical Properties of Trabecular Bone in Human Femoral Head

2006 ◽  
Vol 321-323 ◽  
pp. 1070-1073
Author(s):  
Ye Yeon Won ◽  
Myong Hyun Baek ◽  
Wen Quan Cui ◽  
Kwang Kyun Kim
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Femoral Head ◽  
Trabecular Bone ◽  
Volume Fraction ◽  
Reaction Force ◽  
Bone Volume ◽  
Fe Model ◽  
Micro Ct ◽  
Trabecular Thickness

This study investigates micro-structural and mechanical properties of trabecular bone in human femoral head with and without osteoporosis using a micro-CT and a finite element model. 15 cored trabecular bone specimens with 20 of diameter were obtained from femoral heads with osteoporosis resected for total hip arthroplasty, and 5 specimens were removed from femoral head of cadavers, which has no history of musculoskeletal diseases. A high-resolution micro-CT system was used to scan each specimen to obtain histomorphometry indexes. Based on the micro-images, a FE-model was created to determine mechanical property indexes. While the non-osteoporosis group had increases the trabecular thickness, the bone volume, the bone volume fraction, the degree of anisotropy and the trabecular number compared with those of osteoporotic group, the non-osteoporotic group showed decreases in trabecular separation and structure model index. Regarding the mechanical property indexes, the reaction force and the Young's modulus were lower in the osteoporotic group than in non-osteoporotic group. Our data shows salient deteriorations in trabecular micro-structural and mechanical properties in human femoral head with osteoporosis.

scholarly journals Bone Micro-CT Assessments in an Orchidectomised Rat Model Supplemented withEurycoma longifolia

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Rosmaliza Ramli ◽  
Mohd Fadhli Khamis ◽  
Ahmad Nazrun Shuid
Keyword(s):  
Trabecular Bone ◽  
Bone Microarchitecture ◽  
Bone Volume ◽  
High Dose ◽  
Micro Ct ◽  
Sprague Dawley ◽  
Elderly Male ◽  
Trabecular Bone Microarchitecture ◽  
Eurycoma Longifolia ◽  
Induced Changes

Recent studies suggested thatEurycoma longifolia, a herbal plant, may have the potential to treat osteoporosis in elderly male. This study aimed to determine the effects ofEurycoma longifoliasupplementation on the trabecular bone microarchitecture of orchidectomised rats (androgen-deficient osteoporosis model). Forty-eight-aged (10–12 months old)Sprague Dawleyrats were divided into six groups of sham-operated (SHAM), orchidectomised control (ORX), orchidectomised + 7 mg/rat testosterone enanthate (TEN) and orchidectomised +Eurycoma longifolia30 mg/kg (EL30), orchidectomised +Eurycoma longifolia60 mg/kg (EL60), orchidectomised +Eurycoma longifolia90 mg/kg (EL90). Rats were euthanized following six weeks of treatment. The left femora were used to measure the trabecular bone microarchitecture using micro-CT. Orchidectomy significantly decreased connectivity density, trabecular bone volume, and trabecular number compared to the SHAM group. Testosterone replacement reversed all the orchidectomy-induced changes in the micro-CT parameters. EL at 30 and 60 mg/kg rat worsened the trabecular bone connectivity density and trabecular separation parameters of orchidectomised rats. EL at 90 mg/kg rat preserved the bone volume. High dose of EL (90 mg/kg) may have potential in preserving the bone microarchitecture of orchidectomised rats, but lower doses may further worsen the osteoporotic changes.

Whole human vertebral body BMD and bone volume fraction examined by DXA and micro-CT

Bone ◽  
2009 ◽  
Vol 44 ◽  
pp. S375
Author(s):  
E. Perilli⁎ ◽  
A.M. Briggs ◽  
J.D. Wark ◽  
S. Kantor ◽  
I.H. Parkinson ◽  
...  
Keyword(s):  
Vertebral Body ◽  
Volume Fraction ◽  
Bone Volume ◽  
Micro Ct ◽  
Bone Volume Fraction

scholarly journals Cortical Bone Modifications after Radiotherapy: Cortex Porosity and Osteonal Changes Evaluated Over Time

2021 ◽  
Vol 32 (1) ◽  
pp. 9-15
Author(s):  
Juliana Simeão Borges ◽  
Gustavo Davi Rabelo ◽  
Milena Suemi Irie ◽  
João Lucas Carvalho Paz ◽  
Rubens Spin-Neto ◽  
...  
Keyword(s):  
Cortical Bone ◽  
Cortical Thickness ◽  
Bone Microarchitecture ◽  
Total Porosity ◽  
Control Area ◽  
Bone Volume ◽  
Control Group ◽  
Significant Difference ◽  
Area And Perimeter ◽  
Haversian Canals

Abstract Aiming to evaluate cortical bone microarchitecture and osteonal morphology after irradiation, twelve male New Zealand rabbits were used. The animals were divided: control group (no radiation-NIr); and 3 irradiated groups, sacrificed after: 7 (Ir7d); 14 (Ir14d) and 21 (Ir21d) days. A single radiation dose of 30 Gy was used. Computed microtomography analyzed the cortical microarchitecture: cortical thickness (CtTh), bone volume (BV), total porosity (Ct.Po), intracortical porosity (CtPo-cl), channel/pore number (Po.N), fractal dimension (FD) and degree of anisotropy (Ct.DA). After scan, osteonal morphology was histologically assessed by means: area and perimeter of the osteons (O.Ar; O.p) and of the Haversian canals (C.Ar; C.p). Microtomographic analysis were performed by ANOVA, followed by Tukey and Dunnet tests. Osteon morphology analyses were performed by Kruskal-Wallis, and test Dunn’s. Cortical thickness was significant difference (p<0.010) between the NIr and irradiated groups, with thicker cortex at Ir7d (1.15±0.09). The intracortical porosity revealed significant difference (p<0.001) between irradiated groups and NIr, with lower value for Ir7d (0.29±0.09). Bone volume was lower in Ir14d compared to control. Area and perimeter of the osteons were statistically different (p<0.0001) between NIr and Ir7d. Haversian canals also revealed lower values (p<0.0001) in Ir7d (80.57±9.3; 31.63±6.5) compared to NIr and irradiated groups. Cortical microarchitecture was affected by radiation, and the effects appear to be time-dependent, mostly regarding the osteons morphology at the initial days. Cortex structure in Ir21d revealed similarities to control suggesting that microarchitecture resembles normal condition after a period.

scholarly journals Observations of the creep of polar firn

2021 ◽  
pp. 1-19
Author(s):  
Yuan Li ◽  
Ian Baker
Keyword(s):  
Total Porosity ◽  
Constant Load ◽  
Primary Creep ◽  
Secondary Creep ◽  
Micro Ct ◽  
Creep Tests ◽  
Thin Sections ◽  
Compressive Stresses ◽  
Optical Images ◽  
Before And After

Abstract Constant-load creep tests were performed at −10°C at various compressive stresses from 0.05 to 0.75 MPa on specimens taken every 10 m along a firn core extracted at Summit, Greenland in June 2017. The microstructures before and after creep testing were examined using both X-ray microtomography (micro-CT) and optical images from thin sections. An Andrade-like equation was used to describe the primary creep behavior and yielded the time exponent k of 0.17–0.76. The onset of secondary creep occurred at strains of ~0.5–3% but was sometimes not observed at all in shallow firn specimens and at stresses ⩽0.43 MPa even for strain up to 32%. For the 50–80 m firn crept at stresses ⩾0.55 MPa, secondary creep occurred at strains of 2.6 ± 0.28%, and the stress exponent, n, in Glen's law, was found to range from 4.1 to 4.6, similar to those observed for fully dense ice. Micro-CT observations of crept specimens showed that in most cases, the specific surface area, the total porosity and the structure model index decreased, while the structure thickness increased with increasing density. These microstructural characteristics are consistent with the densification of the firn. Optical images from thin sections showed that recrystallization occurred in some specimens that had undergone secondary creep.

scholarly journals A digital rock physics approach to effective and total porosity for complex carbonates: pore-typing and applications to electrical conductivity

2019 ◽  
Vol 89 ◽  
pp. 05002 ◽  
Author(s):  
Christoph H. Arns ◽  
Han Jiang ◽  
Hongyi Dai ◽  
Igor Shikhov ◽  
Nawaf Sayedakram ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Multiple Scales ◽  
Rock Physics ◽  
Total Porosity ◽  
Structural Heterogeneity ◽  
Micro Ct ◽  
Digital Rock Physics ◽  
Consistent Manner ◽  
The Face ◽  
Pore Types

Recent advances in micro-CT techniques allow imaging heterogeneous carbonates at multiple scales and including voxel-wise registration of images at different resolution or in different saturation states. This enables characterising such carbonates at the pore-scale targeting the optimizing of hydrocarbon recovery in the face of structural heterogeneity, resulting in complex spatial fluid distributions. Here we determine effective and total porosity for different pore-types in a complex carbonate and apply this knowledge to improve our understanding of electrical properties by integrating experiment and simulation in a consistent manner via integrated core analysis. We consider Indiana Limestone as a surrogate for complex carbonate rock and type porosity in terms of macro- and micro-porosity using micro-CT images recorded at different resolution. Effective and total porosity fields are derived and partitioned into regions of macro-porosity, micro-porosity belonging to oolithes, and micro-porosity excluding oolithes’ rims. In a second step we use the partitioning of the micro-porosity to model the electrical conductivity of the limestone, matching experimental measurements by finding appropriate cementation exponents for the two different micro-porosity regions. We compare these calculations with calculations using a single cementation exponent for the full micro-porosity range. The comparison is extended to resistivity index at partial saturation, further testing the assignment of Archie parameters, providing insights into the regional connectivity of the different pore types.

Simvastatin Loaded Nano Hydroxyapatite in Bone Regeneration: A Study in the Rabbit Femoral Condyle

2019 ◽  
Vol 16 (6) ◽  
pp. 530-537 ◽  
Author(s):  
Elna Paul Chalisserry ◽  
Seung Yun Nam ◽  
Sukumaran Anil
Keyword(s):  
Bone Regeneration ◽  
Femoral Condyle ◽  
Bone Substitutes ◽  
Control Site ◽  
Bone Volume ◽  
Bone Morphogenetic Protein 2 ◽  
Micro Ct ◽  
Mineral Density ◽  
Hydroxyapatite Ceramics ◽  
Hydroxyapatite Scaffold

Background: Enhancement of the bone regenerative capacity of the bone substitutes could be achieved by incorporating bioactive agents such as proteins, and different drugs. Simvastatin, an inhibitor of cholesterol synthesis, stimulates bone formation by enhancing the expression of Bone Morphogenetic Protein-2 (BMP-2) in osteoblasts. Objective: The objective of the study is to evaluate bone regeneration following simvastatin loaded nano-hydroxyapatite scaffold in the bone defect created on the femoral condyle of rabbits. Methods: Twelve adult, New Zealand white rabbits were used in the study. Twenty-four defects of size 5x8 mm were created on the lateral aspect of the femoral condyle. The defects were filled with either Nano-Hydroxyapatite (nHA) particles alone or nHA with Simvastatin (SIM). The condyles were retrieved after 8 weeks and analyzed using micro CT and histology. Results: The Bone Mineral Density (BMD) was significantly higher for the defects filled with SIM loaded nHA compared to the nHA site. Micro CT showed a significantly higher bone volume in the defects filled with Simvastatin loaded site compared to the control site. Quantitative analysis of the histologic sections also showed significantly higher bone volume in the defects filled with SIM loaded nHA (57.2±4.8) compared to nHA alone (50.1±5.5). Conclusion: Based on the results, it can be concluded that local delivery of simvastatin enhanced the bone regeneration in rabbit femoral condyle. Simvastatin could be used as an activator to enhance bone regeneration in bone defects along with hydroxyapatite ceramics.

Using Micro-CT Scanning to Quantitative Characterize Porosity in High Pressure Die Castings and Semi-Solid Castings

2022 ◽  
Vol 327 ◽  
pp. 33-44
Author(s):  
Stephen P. Midson
Keyword(s):  
High Pressure ◽  
Total Porosity ◽  
Ct Scanning ◽  
Quantitative Information ◽  
X Rays ◽  
Micro Ct ◽  
Resolution Limit ◽  
Aluminum Castings ◽  
Semi Solid ◽  
Die Castings

Porosity is one of the main defects that limits the performance of castings. Porosity in aluminum castings can originate from several sources, including the volumetric shrinkage occurring during solidification, the precipitation of dissolved hydrogen, and entrapment of gasses such as air, boiling water, vaporized lubricants, etc. Traditional methods of identifying and measuring porosity in castings include 2D x-rays, sectioning and polishing, and Archimedes density measurements, but none of these provide a satisfactory quantitative estimate of the size, total volume and distribution of the pores. X-ray CT scanning is a relatively new method that generates not only a 3-dimensional view of the size and distribution of the pores, but can also provide quantitative information of the volume, surface area, size, shape and position of each pore within a casting. Micro-CT scanning is a specialized sub-category of CT scanning, which provides excellent resolution of fine porosity (a resolution limit of 4 microns in one of the case-stores presented in this paper), but it should be noted that the resolution limit in CT scanning techniques is related to sample size. This paper describes results from micro-CT scanning studies of two high pressure die castings and a semi-solid casting, and provides quantitative data on the total porosity content, and the porosity distribution. The paper will also demonstrate the capabilities of the micro-CT scanning process to provide a quantitative comparison of the porosity content in these different types of aluminum castings.

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