scholarly journals Cross-sex testosterone therapy in ovariectomized mice: addition of low-dose estrogen preserves bone architecture

2017 ◽  
Vol 313 (5) ◽  
pp. E540-E551 ◽  
Author(s):  
Teddy G. Goetz ◽  
Ramanaiah Mamillapalli ◽  
Maureen J. Devlin ◽  
Amy E. Robbins ◽  
Masoumeh Majidi-Zolbin ◽  
...  
Keyword(s):  
Low Dose ◽  
Volume Fraction ◽  
Estrogen Therapy ◽  
Bone Volume ◽  
Bone Architecture ◽  
Bone Volume Fraction ◽  
Trabecular Thickness ◽  
Trabecular Separation ◽  
Bone Acquisition ◽  
Trabecular Number

Cross-sex hormone therapy (XHT) is widely used by transgender people to alter secondary sex characteristics to match their desired gender presentation. Here, we investigate the long-term effects of XHT on bone health using a murine model. Female mice underwent ovariectomy at either 6 or 10 wk and began weekly testosterone or vehicle injections. Dual-energy X-ray absorptiometry (DXA) was performed (20 wk) to measure bone mineral density (BMD), and microcomputed tomography was performed to compare femoral cortical and trabecular bone architecture. The 6-wk testosterone group had comparable BMD with controls by DXA but reduced bone volume fraction, trabecular number, and cortical area fraction and increased trabecular separation by microcomputed tomography. Ten-week ovariectomy/XHT maintained microarchitecture, suggesting that estrogen is critical for bone acquisition during adolescence and that late, but not early, estrogen loss can be sufficiently replaced by testosterone alone. Given these findings, we then compared effects of testosterone with effects of weekly estrogen or combined testosterone/low-dose estrogen treatment after a 6-wk ovariectomy. Estrogen treatment increased spine BMD and microarchitecture, including bone volume fraction, trabecular number, trabecular thickness, and connectivity density, and decreased trabecular separation. Combined testosterone-estrogen therapy caused similar increases in femur and spine BMD and improved architecture (increased bone volume fraction, trabecular number, trabecular thickness, and connectivity density) to estrogen therapy and were superior compared with mice treated with testosterone only. These results demonstrate estradiol is critical for bone acquisition and suggest a new cross-sex hormone therapy adding estrogens to testosterone treatments with potential future clinical implications for treating transgender youth or men with estrogen deficiency.

scholarly journals Measurement of trabecular bone parameters with different bone thickness and voxel size in mice using micro CT

2019 ◽  
Vol 15 (1) ◽  
pp. 65-68
Author(s):  
Nurin Nadzlah Abu Bakar ◽  
Basri Saidi ◽  
Lyana Shahirah Mohamad Yamin
Keyword(s):  
Trabecular Bone ◽  
Volume Fraction ◽  
Bone Volume ◽  
Bone Morphology ◽  
Bone Volume Fraction ◽  
Voxel Size ◽  
Trabecular Thickness ◽  
Bone Parameters ◽  
Trabecular Separation ◽  
Trabecular Number

Micro-CT is one of the best modalities in assessing bone morphology and microarchitecture in small animal models. Voxel size is directly related to the image resolution as it influences the bone morphology results. The purpose of this study was to assess the effects of t different thicknesses of structures on the trabecular bone qualitative parameters. It was also to find out the most appropriate voxel size when scanning a certain or specific body part with different thicknesses. Five BALB-C breed mice carcasses were scanned using two different voxel sizes of 18 and 35 µm. The scanning acquisition times were recorded to be compared and the trabecular bone parameters measurements were taken. Both trabecular number and trabecular separation were increased in thicker structures meanwhile bone volume fraction and trabecular thickness values were inconsistent with the increment of the structure thickness. The bone volume fraction, trabecular thickness and trabecular separation were higher in larger voxel size and vice versa for trabecular number. The scanning acquisition time has no apparent correlation with the trabecular bone parameters. The thickness of the bone structure did affect trabecular number and trabecular separation significantly but less affecting bone volume fraction and trabecular thickness. All trabecular bone parameters were found affected by the size of scanning voxel size used. The usage of 35 µm voxel was more recommended than 18 µm to save time and give out less radiation dose to specimen unless the detailed features of the trabecular pattern was very important.

scholarly journals Effects of Leukocyte-Platelet-Rich Plasma on the Alveolar Bone Changes During Orthodontic Tooth Movement in Rabbits: A Micro-CT Study

2019 ◽  
Vol 53 (4) ◽  
pp. 264-271
Author(s):  
Theerasak Nakornnoi ◽  
Chidchanok Leethanakul ◽  
Bancha Samruajbenjakun
Keyword(s):  
Alveolar Bone ◽  
Tooth Movement ◽  
Volume Fraction ◽  
Platelet Rich Plasma ◽  
Orthodontic Tooth Movement ◽  
Bone Volume ◽  
Bone Volume Fraction ◽  
Trabecular Thickness ◽  
Bone Changes ◽  
Trabecular Separation

Objective: To investigate the effects of leukocyte-platelet-rich plasma (L-PRP) on the alveolar bone changes at the compression and tension sides during orthodontic tooth movement. Materials and Methods: Around 20 New Zealand white rabbits were used in a split-mouth design. The maxillary first premolar was moved mesially with a nickel-titanium closed-coil spring. One side of the maxilla was randomly injected with L-PRP, while the contralateral side served as the control which received normal saline. The alveolar bone adjacent to the maxillary first premolar was scanned using microcomputed tomography at days 0, 7, 14, and 28. Microstructural parameters including bone volume fraction, trabecular thickness, and trabecular separation of alveolar bone were assessed on the compression and tension sides of the maxillary first premolar. Results: Compared between the groups, the L-PPR group showed a significantly decreased bone volume fraction on the compression side on days 7 and 14 but significantly increased bone volume fraction on the tension side on day 14. However, there were no statistically significant differences in the parameters of trabecular thickness and trabecular separation. Conclusion: Local administration of L-PRP may promote bone resorption on the compression side and bone formation on the tension side at the initial stage of orthodontic tooth movement.

Architectural changes of trabecular bone caused by the remodeling process

2005 ◽  
Vol 874 ◽  
Author(s):  
Richard Weinkamer ◽  
Markus A. Hartmann ◽  
Yves Brechet ◽  
Peter Fratzl
Keyword(s):  
Trabecular Bone ◽  
Feedback Loop ◽  
Mechanical Response ◽  
Volume Fraction ◽  
Bone Volume ◽  
Bone Architecture ◽  
Mechanical Problem ◽  
Bone Volume Fraction ◽  
Obvious Effect ◽  
Trabecular Bone Architecture

AbstractUsing a stochastic lattice model we have studied the architectural changes of trabecular bone occurring while the structure is remodeled. Our model considers the mechanical feedback loop, which control the remodeling process. A fast algorithm was employed to solve approximately the mechanical problem. A general feature of the model is that a networklike structure emerges, which further coarsens while the bone volume fraction remains unchanged. Decreasing the mechanical response of the system by either lowering the external load or the internal mechano-sensitivity leads not only to a reduction of the bone volume fraction, but results in topological changes of the trabecular bone architecture, where the loss of horizontal trabeculae is the most obvious effect.

scholarly journals Extracorporeal Shockwave Therapy Modulates the Expressions of Proinflammatory Cytokines IL33 and IL17A, and Their Receptors ST2 and IL17RA, within the Articular Cartilage in Early Avascular Necrosis of the Femoral Head in a Rat Model

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Jai-Hong Cheng ◽  
Shun-Wun Jhan ◽  
Chieh-Cheng Hsu ◽  
Hung-Wen Chiu ◽  
Shan-Ling Hsu
Keyword(s):  
Articular Cartilage ◽  
Femoral Head ◽  
Avascular Necrosis ◽  
Volume Fraction ◽  
Bone Volume Fraction ◽  
Trabecular Thickness ◽  
Extracorporeal Shockwave Therapy ◽  
Extracorporeal Shockwave ◽  
Shockwave Therapy ◽  
Trabecular Number

Avascular necrosis (AVN) of the femoral head (AVNFH) is a disease caused by injury to the blood supply of the femoral head, resulting in a collapse with osteonecrosis and damage to the articular cartilage. Extracorporeal shockwave therapy (ESWT) has been demonstrated to improve AVNFH owing to its anti-inflammation activity, angiogenesis effect, and tissue regeneration in clinical treatment. However, there are still so many pieces of the jigsaw that need to be fit into place in order to ascertain the mechanism of ESWT for the treatment of AVNFH. The study demonstrated that ESWT significantly protected the trabecular bone volume fraction BV/TV ( P < 0.01 ) and the trabecular thickness ( P < 0.001 ), while in contrast, the trabecular number and trabecular separation were not significantly different after treatment as compared with AVNFH. ESWT protected the articular cartilage in animal model of AVNFH. The levels of IL1-β and IL33 were significantly induced in the AVNFH group ( P < 0.001 ) as compared with Sham and ESWT groups and reduced in ESWT group ( P < 0.001 ) as compared with AVNFH group. In addition, the expression of the receptor of IL33, ST2, was reduced in AVNFH and induced after ESWT ( P < 0.001 ). The expression of IL17A was induced in the AVNFH group ( P < 0.001 ) and reduced in the ESWT group ( P < 0.001 ). Further, the expression of the receptor of IL17A, IL17RA, was reduced in the AVNFH group ( P < 0.001 ) and improved to a normal level in the ESWT group as compared with Sham group ( P < 0.001 ). Taken together, the results of the study indicated that ESWT modulated the expression of IL1-β, pro-inflammatory cytokines IL33 and IL17A, and their receptors ST2 and IL17RA, to protect against loss of the extracellular matrix in the articular cartilage of early AVNFH.

scholarly journals Retaining Residual Ovarian Tissue following Ovarian Failure Has Limited Influence on Bone Loss in Aged Mice

2010 ◽  
Vol 2010 ◽  
pp. 1-6
Author(s):  
Zelieann R. Craig ◽  
Samuel L. Marion ◽  
Janet L. Funk ◽  
Mary L. Bouxsein ◽  
Patricia B. Hoyer
Keyword(s):  
Bone Loss ◽  
Volume Fraction ◽  
Ovarian Tissue ◽  
Ovarian Failure ◽  
Bone Volume ◽  
Bone Volume Fraction ◽  
Trabecular Thickness ◽  
Ct Analysis ◽  
Time Point ◽  
Young Mice

Previous work showed that retaining residual ovarian tissue protects young mice from accelerated bone loss following ovarian failure. The present study was designed to determine whether this protection is also present in aged animals. Aged (9–12 months) C57BL/6Hsd female mice were divided into: CON (vehicle), VCD (160 mg/kg; 15d), or OVX (ovariectomized). Lumbar BMD was monitored by DXA andμCT used to assess vertebral microarchitecture. BMD was not different between VCD and CON at any time point but was lower (P<.05) than baseline, starting 1 month after ovarian failure in VCD and OVX mice. FollowingμCT analysis there were no differences between CON and VCD, but OVX mice had lower bone volume fraction, trabecular thickness, and a trend for decreased connectivity density. These findings provide evidence that retention of residual ovarian tissue may protect aged follicle-depleted mice from accelerated bone loss to a lesser extent than that observed in young mice.

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 Radioprotective Effect of Sodium Selenite on Mandible of Irradiated Rats

2019 ◽  
Vol 30 (3) ◽  
pp. 232-237
Author(s):  
Mayra Cristina Yamasaki ◽  
Rocharles CavalcanteFontenele ◽  
Yuri Nejaim ◽  
Deborah Queiroz Freitas
Keyword(s):  
Sodium Selenite ◽  
Volume Fraction ◽  
Bone Microarchitecture ◽  
Bone Volume ◽  
Radioprotective Effect ◽  
Control Group ◽  
X Rays ◽  
Bone Volume Fraction ◽  
Trabecular Thickness ◽  
Significant Difference

Abstract The purpose of this study was to test the radioprotective effect of selenium in the bone microarchitecture of irradiated rats mandibles. Forty rats were separated into 4 groups with 10 animals: control group (CG), irradiated group (IG), sodium selenite group (SSG) and sodium selenite irradiated group (SSIG). A single dose of 0.8 mg/kg sodium selenite was administered intraperitoneally in the SSG and SSIG groups. One hour later, animals of IG and SSIG groups were irradiated with 15 Gy of x-rays. Forty days after radiation a bilateral extraction of the mandibular first molars was performed. After the extraction procedure, five rats were killed after fifteen days and others five after thirty days. Micro- computed tomography was used to evaluate cortical and trabecular bone of each rat. The mean and standard deviation of each bone microarchitecture parameter were analyzed using the statistical test of two-way Analysis of Variance (ANOVA). At 15 days, the bone volume presented higher values in the CG and SSG groups (p=0.001). The same groups presented statistically significant higher values when bone volume fraction (p<0.001) and trabecular thickness (p<0.001) were analyzed. At 30 days, it was observed that in relation to the bone volume fraction, SSG group presented the highest value while SSIG group had the lowest value, with statistically significant difference (p=0.016). Sodium selenite demonstrated a median radioprotective effect in the bone microarchitecture of irradiated mandibles, which indicates the substance may be a potential radioprotective agent against chronic effects of high doses of ionizing radiation.

scholarly journals In vivo microcomputed tomography evaluation of rat alveolar bone and root resorption during orthodontic tooth movement

2012 ◽  
Vol 83 (3) ◽  
pp. 402-409 ◽  
Author(s):  
Nan Ru ◽  
Sean Shih-Yao Liu ◽  
Li Zhuang ◽  
Song Li ◽  
Yuxing Bai
Keyword(s):  
Alveolar Bone ◽  
Tooth Movement ◽  
Root Resorption ◽  
Volume Fraction ◽  
Orthodontic Tooth Movement ◽  
Bone Volume ◽  
Structure Model ◽  
Bone Volume Fraction ◽  
Trabecular Thickness

ABSTRACT Objective: To observe the real-time microarchitecture changes of the alveolar bone and root resorption during orthodontic treatment. Materials and Methods: A 10 g force was delivered to move the maxillary left first molars mesially in twenty 10-week-old rats for 14 days. The first molar and adjacent alveolar bone were scanned using in vivo microcomputed tomography at the following time points: days 0, 3, 7, and 14. Microarchitecture parameters, including bone volume fraction, structure model index, trabecular thickness, trabecular number, and trabecular separation of alveolar bone, were measured on the compression and tension side. The total root volume was measured, and the resorption crater volume at each time point was calculated. Univariate repeated measures analysis of variance with Bonferroni corrections were performed to compare the differences in each parameter between time points with significance level at P &lt; .05. Results: From day 3 to day 7, bone volume fraction, structure model index, trabecular thickness, and trabecular separation decreased significantly on the compression side, but the same parameters increased significantly on the tension side from day 7 to day 14. Root resorption volume of the mesial root increased significantly on day 7 of orthodontic loading. Conclusions: Real-time root and bone resorption during orthodontic movement can be observed in 3 dimensions using in vivo micro-CT. Alveolar bone resorption and root resorption were observed mostly in the apical third on day 7 on the compression side; bone formation was observed on day 14 on the tension side during orthodontic tooth movement.

Sign in / Sign up

Export Citation Format

Share Document