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Sample records for greater trabecular vbmd

  1. Trabecular bone deficits among Vietnamese immigrants.

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    Melton, L J; Marquez, M A; McCready, L K; Achenbach, S J; Riggs, B L; Amin, S; Khosla, S

    2011-05-01

    Compared to white women, lower areal bone mineral density (aBMD) in middle-aged Vietnamese immigrants is due to reduced trabecular volumetric bone mineral density (vBMD), which in turn is associated with greater trabecular separation along with lower estrogen levels. The epidemiology of osteoporosis in Asian populations is still poorly known, but we previously found a deficit in lumbar spine aBMD among postmenopausal Southeast Asian women, compared to white women, that persisted after correction for bone size. This issue was revisited using more sophisticated imaging techniques. Twenty Vietnamese immigrants (age, 44-79 years) were compared to 162 same-aged white women with respect to aBMD at the hip, spine and wrist, vBMD at the hip and spine by quantitative computed tomography and vBMD and bone microstructure at the ultradistal radius by high-resolution pQCT. Bone turnover and sex steroid levels were assessed in a subset (20 Vietnamese and 40 white women). The aBMD was lower at all sites among the Vietnamese women, but femoral neck vBMD did not differ from middle-aged white women. Significant differences in lumbar spine and ultradistal radius vBMD in the Vietnamese immigrants were due to lower trabecular vBMD, which was associated with increased trabecular separation. Bone resorption was elevated and bone formation depressed among the Vietnamese immigrants, although trends were not statistically significant. Serum estradiol was positively associated with trabecular vBMD in the Vietnamese women, but their estrogen levels were dramatically lower compared to white women. Although reported discrepancies in aBMD among Asian women are mainly an artifact of smaller bone size, we identified a specific deficit in the trabecular bone among a sample of Vietnamese immigrants that may be related to low estrogen levels and which needs further study.

  2. Adipose tissue depot volume relationships with spinal trabecular bone mineral density in African Americans with diabetes.

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    Gary C Chan

    Full Text Available Changes in select adipose tissue volumes may differentially impact bone mineral density. This study was performed to assess cross-sectional and longitudinal relationships between computed tomography-determined visceral (VAT, subcutaneous (SAT, inter-muscular (IMAT, and pericardial adipose tissue (PAT volumes with respective changes in thoracic vertebral and lumbar vertebral volumetric trabecular bone mineral density (vBMD in African Americans with type 2 diabetes. Generalized linear models were fitted to test relationships between baseline and change in adipose volumes with change in vBMD in 300 African American-Diabetes Heart Study participants; adjustment was performed for age, sex, diabetes duration, study interval, smoking, hypertension, BMI, kidney function, and medications. Participants were 50% female with mean ± SD age 55.1±9.0 years, diabetes duration 10.2±7.2 years, and BMI 34.7±7.7 kg/m2. Over 5.3 ± 1.4 years, mean vBMD decreased in thoracic/lumbar spine, while mean adipose tissue volumes increased in SAT, IMAT, and PAT, but not VAT depots. In fully-adjusted models, changes in lumbar and thoracic vBMD were positively associated with change in SAT (β[SE] 0.045[0.011], p<0.0001; 0.40[0.013], p = 0.002, respectively. Change in thoracic vBMD was positively associated with change in IMAT (p = 0.029 and VAT (p = 0.016; and change in lumbar vBMD positively associated with baseline IMAT (p<0.0001. In contrast, vBMD was not associated with change in PAT. After adjusting for BMI, baseline and change in volumes of select adipose depots were associated with increases in thoracic and lumbar trabecular vBMD in African Americans. Effects of adiposity on trabecular bone appear to be site-specific and related to factors beyond mechanical load.

  3. High Insulin Levels in KK-Ay Diabetic Mice Cause Increased Cortical Bone Mass and Impaired Trabecular Micro-Structure

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    Cen Fu

    2015-04-01

    Full Text Available Type 2 diabetes mellitus (T2DM is a chronic disease characterized by hyperglycemia, hyperinsulinemia and complications, including obesity and osteoporosis. Rodents have been widely used to model human T2DM and investigate its effect on the skeleton. We aimed to investigate skeletal alterations in Yellow Kuo Kondo (KK-Ay diabetic mice displaying high insulin and glucose levels. Bone mineral density (BMD, micro-architecture and bone metabolism-related genes were analyzed. The total femoral areal BMD (aBMD, cortical volumetric BMD (vBMD and thickness were significantly increased in KK-Ay mice, while the trabecular vBMD and mineralized bone volume/tissue volume (BV/TV, trabecular thickness and number were decreased compared to C57BL mice. The expression of both osteoblast-related genes, such as osteocalcin (OC, bone sialoprotein, Type I Collagen, osteonectin, RUNX2 and OSX, and osteoclast-related genes, such as TRAP and TCIRG, were up-regulated in KK-Ay mice. Correlation analyses showed that serum insulin levels were positively associated with aBMD, cortical vBMD and thickness and negatively associated with trabecular vBMD and micro-architecture. In addition, serum insulin levels were positively related to osteoblast-related and osteoclast-related gene expression. Our data suggest that high insulin levels in KK-Ay diabetic mice may increase cortical bone mass and impair trabecular micro-structure by up-regulating osteoblast-and osteoclast-related gene expression.

  4. Lower trabecular volumetric BMD at metaphyseal regions of weight-bearing bones is associated with prior fracture in young girls.

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    Farr, Joshua N; Tomás, Rita; Chen, Zhao; Lisse, Jeffrey R; Lohman, Timothy G; Going, Scott B

    2011-02-01

    Understanding the etiology of skeletal fragility during growth is critical for the development of treatments and prevention strategies aimed at reducing the burden of childhood fractures. Thus we evaluated the relationship between prior fracture and bone parameters in young girls. Data from 465 girls aged 8 to 13 years from the Jump-In: Building Better Bones study were analyzed. Bone parameters were assessed at metaphyseal and diaphyseal sites of the nondominant femur and tibia using peripheral quantitative computed tomography (pQCT). Dual-energy X-ray absorptiometry (DXA) was used to assess femur, tibia, lumbar spine, and total body less head bone mineral content. Binary logistic regression was used to evaluate the relationship between prior fracture and bone parameters, controlling for maturity, body mass, leg length, ethnicity, and physical activity. Associations between prior fracture and all DXA and pQCT bone parameters at diaphyseal sites were nonsignificant. In contrast, lower trabecular volumetric BMD (vBMD) at distal metaphyseal sites of the femur and tibia was significantly associated with prior fracture. After adjustment for covariates, every SD decrease in trabecular vBMD at metaphyseal sites of the distal femur and tibia was associated with 1.4 (1.1-1.9) and 1.3 (1.0-1.7) times higher fracture prevalence, respectively. Prior fracture was not associated with metaphyseal bone size (ie, periosteal circumference). In conclusion, fractures in girls are associated with lower trabecular vBMD, but not bone size, at metaphyseal sites of the femur and tibia. Lower trabecular vBMD at metaphyseal sites of long bones may be an early marker of skeletal fragility in girls. Copyright © 2011 American Society for Bone and Mineral Research.

  5. Trabecular microstructure and surface changes in the greater tuberosity in rotator cuff tears

    International Nuclear Information System (INIS)

    Jiang, Yebin; Zhao, Jenny; Ouyang, Xiaolong; Genant, Harry K.; Holsbeeck, Marnix T. van; Flynn, Michael J.

    2002-01-01

    Abstract Objective. When planning surgery in patients with rotator cuff tear, strength of bone at the tendon insertion and trabecular bone structure in the greater tuberosity are usually taken into consideration. We investigated radiographic changes in bone structure of the greater tuberosity in rotator cuff tears.Design. Twenty-two human cadaveric shoulders from subjects ranging from 55 to 75 years of age were obtained. The integrity of the rotator cuff was examined by sonography to determine if it is intact without any tear, or torn partially or completely. The humeral head was sectioned in 3 mm thick coronal slab sections and microradiographed. After digitization of the microradiographs and imaging processing with in-house semi-automated image processing software tools developed using software interfaces on a Sun workstation, the trabecular histomorphometrical structural parameters and connectivity in the greater tuberosity were quantified. The degenerative changes on the surface of the greater tuberosity were interpreted blindly by 2 independent readers.Results. Among the 22 shoulder specimens, the rotator cuff was found intact in 10 shoulders, partially in 7 and fully torn in 5. Statistically significant loss in apparent trabecular bone volume fraction, number of trabecular nodes, and number of trabecular branches, and a statistically significant increase in apparent trabecular separation and number of trabecular free ends were found in the greater tuberosity of the shoulders with tears. The loss was greater in association with full tear than in partial tear. Thickening of the cortical margin of the enthesis, irregularity of its surface, and calcification beyond the tidemark were observed in 2 (20%) shoulders with intact rotator cuff, in 6 (86%) shoulders with partial tear, and in 5 (100%) shoulders with full tear.Conclusions. Rotator cuff tears are associated with degenerative changes on the bone surface and with disuse osteopenia of the greater tuberosity

  6. Novel anthropomorphic hip phantom corrects systemic interscanner differences in proximal femoral vBMD

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    Bonaretti, S; Saeed, I; Burghardt, A J; Lang, T; Carpenter, R D; Yu, L; Bruesewitz, M; Khosla, S

    2014-01-01

    Quantitative computed tomography (QCT) is increasingly used in osteoporosis studies to assess volumetric bone mineral density (vBMD), bone quality and strength. However, QCT is confronted by technical issues in the clinical research setting, such as potentially confounding effects of body size on vBMD measurements and lack of standard approaches to scanner cross-calibration, which affects measurements of vBMD in multicenter settings. In this study, we addressed systematic inter-scanner differences and subject-dependent body size errors using a novel anthropomorphic hip phantom, containing a calibration hip to estimate correction equations, and a contralateral test hip to assess the quality of the correction. We scanned this phantom on four different scanners and we applied phantom-derived corrections to in vivo images of 16 postmenopausal women scanned on two scanners. From the phantom study, we found that vBMD decreased with increasing phantom size in three of four scanners and that inter-scanner variations increased with increasing phantom size. In the in vivo study, we observed that inter-scanner corrections reduced systematic inter-scanner mean vBMD differences but that the inter-scanner precision error was still larger than expected from known intra-scanner precision measurements. In conclusion, inter-scanner corrections and body size influence should be considered when measuring vBMD from QCT images. (paper)

  7. Association Between Insulin Resistance and Bone Structure in Nondiabetic Postmenopausal Women

    DEFF Research Database (Denmark)

    Shanbhogue, Vikram V; Finkelstein, Joel S; Bouxsein, Mary L

    2016-01-01

    computed tomography was used to assess bone density and microstructure at the distal radius and tibia. Fasting insulin and glucose was measured and insulin resistance was estimated using homeostasis model assessment of insulin resistance (HOMA-IR) with higher values indicating greater insulin resistance....... RESULTS: There was a negative association between HOMA-IR and bone size and a positive association between HOMA-IR and total vBMD, trabecular vBMD, trabecular thickness and cortical thickness at the radius and tibia. These relationships remained even after adjusting for body weight and other potential...

  8. Areal and volumetric Bone Mineral Density and risk of multiple types of fracture in older men

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    Chalhoub, Didier; Orwoll, Eric S.; Cawthon, Peggy M.; Ensrud, Kristine E.; Boudreau, Robert; Greenspan, Susan; Newman, Anne B.; Zmuda, Joseph; Bauer, Douglas; Cummings, Steven; Cauley, Jane A.

    2016-01-01

    Although many studies have examined the association between low bone mineral density (BMD) and fracture risk in older men, none have simultaneously studied the relationship between multiple BMD sites and risk of different types of fractures. Using data from the Osteoporotic Fractures in Men study, we evaluated the association between areal BMD (aBMD) by dual-energy X-ray absorptiometry (DXA) and volumetric BMD (vBMD) by quantitative computed tomography (QCT) measurements, and different types of fractures during an average of 9.7 years of follow up. Men answered questionnaires about fractures every 4 months (>97% completions). Fractures were confirmed by centralized review of radiographic reports; pathological fractures were excluded. Risk of fractures was assessed at the hip, spine, wrist, shoulder, rib/chest/sternum, ankle/foot/toe, arm, hand/finger, leg, pelvis/coccyx, skull/face and any non-spine fracture. Age and race adjusted Cox proportional-hazards modeling was used to assess the risk of fracture in 3301 older men with both aBMD (at the femoral neck (FN) and lumbar spine) and vBMD (at the trabecular spine and FN, and cortical FN) measurements, with hazard ratios (HRs) expressed per standard deviation (SD) decrease. Lower FN and spine aBMD were associated with an increased risk of fracture at the hip, spine, wrist, shoulder, rib/chest/sternum, arm, and any non-spine fracture (statistically significant HRs per SD decrease ranged from 1.24 - 3.57). Lower trabecular spine and FN vBMD were associated with increased risk of most fractures with statistically significant HRs ranging between 1.27 and 3.69. There was a statistically significant association between FN cortical vBMD and fracture risk at the hip (HR=1.55) and spine sites (HR=1.26), but no association at other fracture sites. In summary, both lower aBMD and vBMD were associated with increased fracture risk. The stronger associations observed for trabecular vBMD than cortical vBMD may reflect the greater

  9. Association Between Insulin Resistance and Bone Structure in Nondiabetic Postmenopausal Women

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    Finkelstein, Joel S.; Bouxsein, Mary L.; Yu, Elaine W.

    2016-01-01

    Context: The clinical consequences of insulin resistance and hyperinsulinemia on bone remain largely unknown. Objective: The objective of the study was to evaluate the effect of insulin resistance on peripheral bone geometry, volumetric bone mineral density (vBMD), bone microarchitecture, and estimated bone strength. Design, Setting, and Participants: This cross-sectional study included 146 postmenopausal, nondiabetic Caucasian women (mean age 60.3 ± 2.7 y) who were participating in the Study of Women's Health Across the Nation. Interventions: There were no interventions. Main Outcome Measures: High-resolution peripheral quantitative computed tomography was used to assess bone density and microstructure at the distal radius and tibia. Fasting insulin and glucose were measured and insulin resistance was estimated using homeostasis model assessment of insulin resistance (HOMA-IR), with higher values indicating greater insulin resistance. Results: There was a negative association between HOMA-IR and bone size and a positive association between HOMA-IR and total vBMD, trabecular vBMD, trabecular thickness, and cortical thickness at the radius and tibia. These relationships remained, even after adjusting for body weight and other potential covariates (eg, time since menopause, cigarette smoking, physical activity, prior use of osteoporosis medications or glucocorticoids). Conclusions: In nondiabetic, postmenopausal women, insulin resistance was associated with smaller bone size, greater volumetric bone mineral density, and generally favorable bone microarchitecture at weight-bearing and nonweight-bearing skeletal sites. These associations were independent of body weight and other potential covariates, suggesting that hyperinsulinemia directly affects bone structure independent of obesity and may explain, in part, the higher trabecular bone density and favorable trabecular microarchitecture seen in individuals with type 2 diabetes mellitus. PMID:27243136

  10. Effects of Odanacatib on the Radius and Tibia of Postmenopausal Women

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    Cheung, Am; Majumdar, S; Brixen, K

    2014-01-01

    results, odanacatib was superior to placebo with respect to increases in trabecular volumetric BMD (vBMD) and estimated compressive strength at the spine, and integral and trabecular vBMD and estimated strength at the hip. Here we report the results of HR-pQCT assessment. 214 postmenopausal women (mean.......64% and 2.66%). At the distal radius, odanacatib significantly improved trabecular thickness and BV/TV versus placebo. At a more proximal radial site, odanacatib attenuated the increase in cortical porosity seen with placebo (treatment difference= -7.7%, p = 0.066). At the distal tibia, odanacatib...... significantly improved trabecular number, separation, and BV/TV versus placebo. Safety and tolerability were similar between treatment groups. In conclusion, odanacatib increased cortical and trabecular density, cortical thickness, aspects of trabecular microarchitecture, and estimated strength at the distal...

  11. Associations of Childhood and Adulthood Cognition with Bone Mineral Density in Later Adulthood: A Population-Based Longitudinal Study

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    Rebecca Bendayan

    2017-07-01

    Full Text Available This study explores the association between cognitive ability in childhood and midlife and bone health outcomes in early old age; and the relationships of these bone measures with contemporaneous and subsequent cognitive ability in the MRC National Survey of Health and Development (NSHD. This British birth cohort assessed areal and volumetric bone mineral density (aBMD and vBMD at age 60–64, derived from peripheral quantitative computed tomography and dual-energy X-ray absorptiometry, and cognitive performance from childhood to age 69, among 866 women and 792 men. Cognitive performance at age 15 was assessed using tests of verbal and non-verbal ability, and mathematics; and memory and search speed tasks were administered at ages 53, 60–64, and 69. Covariates included body size, pubertal timing, smoking, leisure time physical activity, socioeconomic circumstances and menopause timing. Multiple linear regression analyses showed that higher childhood cognitive ability was associated with higher hip aBMD, in women, and greater cortical and trabecular vBMD, in men. For women, there were positive associations between hip aBMD and total vBMD, and contemporaneous cognitive ability with associations also extending to subsequent cognitive ability for total vBMD. For men, some associations with trabecular and total vBMD emerged at ages 60–64 and 69 but only after adjusting for education, occupational class and health behaviors. Our findings highlight that higher cognitive ability in childhood is associated with BMD in early old age and these associations might be explained by social and behavioral pathways. The results suggest that individuals with greater cognitive ability in early life are more likely to engage in healthy behaviors (e.g., leisure time physical activity in adulthood, which in turn are associated with greater BMD later in life. Associations between bone health and cognitive performance should be considered within a life course

  12. Prior ankle fractures in postmenopausal women are associated with low areal bone mineral density and bone microstructure alterations.

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    Biver, E; Durosier, C; Chevalley, T; Herrmann, F R; Ferrari, S; Rizzoli, R

    2015-08-01

    In a cross-sectional analysis in postmenopausal women, prior ankle fractures were associated with lower areal bone mineral density (BMD) and trabecular bone alterations compared to no fracture history. Compared to women with forearm fractures, microstructure alterations were of lower magnitude. These data suggest that ankle fractures are another manifestation of bone fragility. Whether ankle fractures represent fragility fractures associated with low areal bone mineral density (aBMD) and volumetric bone mineral density (vBMD) and/or bone microstructure alterations remains unclear, in contrast to the well-recognised association between forearm fractures and osteoporosis. The objective of this study was to investigate aBMD, vBMD and bone microstructure in postmenopausal women with prior ankle fracture in adulthood, compared with women without prior fracture or with women with prior forearm fractures, considered as typically of osteoporotic origin. In a cross-sectional analysis in the Geneva Retirees Cohort study, 63 women with ankle fracture and 59 with forearm fracture were compared to 433 women without fracture (mean age, 65 ± 1 years). aBMD was measured by dual-energy X-ray absorptiometry; distal radius and tibia vBMD and bone microstructure were measured by high-resolution peripheral quantitative computed tomography. Compared with women without fracture, those with ankle fractures had lower aBMD, radius vBMD (-7.9%), trabecular density (-10.7%), number (-7.3%) and thickness (-4.6%) and higher trabecular spacing (+14.5%) (P ankle fractures were 2.2 and 1.6, respectively, vs 2.2 and 2.7 for forearm fracture, respectively (P ≤ 0.001 for all). Compared to women with forearm fractures, those with ankle fractures had similar spine and hip aBMD, but microstructure alterations of lower magnitude. Women with ankle fractures have lower aBMD and vBMD and trabecular bone alterations, suggesting that ankle fractures are another manifestation of bone fragility.

  13. Proximal Femur Volumetric Bone Mineral Density and Mortality: 13 Years of Follow-Up of the AGES-Reykjavik Study.

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    Marques, Elisa A; Elbejjani, Martine; Gudnason, Vilmundur; Sigurdsson, Gunnar; Lang, Thomas; Sigurdsson, Sigurdur; Aspelund, Thor; Meirelles, Osorio; Siggeirsdottir, Kristin; Launer, Lenore; Eiriksdottir, Gudny; Harris, Tamara B

    2017-06-01

    Bone mineral density (BMD) has been linked to mortality, but little is known about the independent contribution of each endosteal bone compartment and also the rate of bone loss to risk of mortality. We examined the relationships between (1) baseline trabecular and cortical volumetric BMD (vBMD) at the proximal femur, and (2) the rate of trabecular and cortical bone loss and all-cause mortality in older adults from the AGES-Reykjavik study. The analysis of trabecular and cortical vBMD and mortality was based on the baseline cohort of 4654 participants (aged ≥66 years) with a median follow-up of 9.4 years; the association between rate of bone loss and mortality was based on 2653 participants with bone loss data (median follow-up of 5.6 years). Analyses employed multivariable Cox-proportional models to estimate hazard ratios (HRs) with time-varying fracture status; trabecular and cortical variables were included together in all models. Adjusted for important confounders, Cox models showed that participants in the lowest quartile of trabecular vBMD had an increased risk of mortality compared to participants in other quartiles (HR = 1.12; 95% confidence interval (CI), 1.01 to 1.25); baseline cortical vBMD was not related to mortality (HR = 1.08; 95% CI, 0.97 to 1.20). After adjustment for time-dependent fracture status, results were attenuated and not statistically significant. A faster loss (quartile 1 versus quartiles 2-4) in both trabecular and cortical bone was associated with higher mortality risk (HR = 1.37 and 1.33, respectively); these associations were independent of major potential confounders including time-dependent incident fractures (HR = 1.32 and 1.34, respectively). Overall, data suggest that faster bone losses over time in both the trabecular and cortical bone compartments are associated with mortality risk and that measurements of change in bone health may be more informative than single-point measurements in explaining mortality

  14. Black bear parathyroid hormone has greater anabolic effects on trabecular bone in dystrophin-deficient mice than in wild type mice.

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    Gray, Sarah K; McGee-Lawrence, Meghan E; Sanders, Jennifer L; Condon, Keith W; Tsai, Chung-Jui; Donahue, Seth W

    2012-09-01

    Duchenne muscular dystrophy (DMD) is an X-linked neuromuscular disease that has deleterious consequences in muscle and bone, leading to decreased mobility, progressive osteoporosis, and premature death. Patients with DMD experience a higher-than-average fracture rate, particularly in the proximal and distal femur and proximal tibia. The dystrophin-deficient mdx mouse is a model of DMD that demonstrates muscle degeneration and fibrosis and osteoporosis. Parathyroid hormone, an effective anabolic agent for post-menopausal and glucocorticoid-induced osteoporosis, has not been explored for DMD. Black bear parathyroid hormone (bbPTH) has been implicated in the maintenance of bone properties during extended periods of disuse (hibernation). We cloned bbPTH and found 9 amino acid residue differences from human PTH. Apoptosis was mitigated and cAMP was activated by bbPTH in osteoblast cultures. We administered 28nmol/kg of bbPTH 1-84 to 4-week old male mdx and wild type mice via daily (5×/week) subcutaneous injection for 6 weeks. Vehicle-treated mdx mice had 44% lower trabecular bone volume fraction than wild type mice. No changes were found in femoral cortical bone geometry or mechanical properties with bbPTH treatment in wild type mice, and only medio-lateral moment of inertia changed with bbPTH treatment in mdx femurs. However, μCT analyses of the trabecular regions of the distal femur and proximal tibia showed marked increases in bone volume fraction with bbPTH treatment, with a greater anabolic response (7-fold increase) in mdx mice than wild type mice (2-fold increase). Trabecular number increased in mdx long bone, but not wild type bone. Additionally, greater osteoblast area and decreased osteoclast area were observed with bbPTH treatment in mdx mice. The heightened response to PTH in mdx bone compared to wild type suggests a link between dystrophin deficiency, altered calcium signaling, and bone. These findings support further investigation of PTH as an anabolic

  15. FRACTAL ANALYSIS OF TRABECULAR BONE: A STANDARDISED METHODOLOGY

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    Ian Parkinson

    2011-05-01

    Full Text Available A standardised methodology for the fractal analysis of histological sections of trabecular bone has been established. A modified box counting method has been developed for use on a PC based image analyser (Quantimet 500MC, Leica Cambridge. The effect of image analyser settings, magnification, image orientation and threshold levels, was determined. Also, the range of scale over which trabecular bone is effectively fractal was determined and a method formulated to objectively calculate more than one fractal dimension from the modified Richardson plot. The results show that magnification, image orientation and threshold settings have little effect on the estimate of fractal dimension. Trabecular bone has a lower limit below which it is not fractal (λ<25 μm and the upper limit is 4250 μm. There are three distinct fractal dimensions for trabecular bone (sectional fractals, with magnitudes greater than 1.0 and less than 2.0. It has been shown that trabecular bone is effectively fractal over a defined range of scale. Also, within this range, there is more than 1 fractal dimension, describing spatial structural entities. Fractal analysis is a model independent method for describing a complex multifaceted structure, which can be adapted for the study of other biological systems. This may be at the cell, tissue or organ level and compliments conventional histomorphometric and stereological techniques.

  16. Trabecular bone in the calcaneus of runners.

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    Andrew Best

    Full Text Available Trabecular bone of the human calcaneus is subjected to extreme repetitive forces during endurance running and should adapt in response to this strain. To assess possible bone functional adaptation in the posterior region of the calcaneus, we recruited forefoot-striking runners (n = 6, rearfoot-striking runners (n = 6, and non-runners (n = 6, all males aged 20-41 for this institutionally approved study. Foot strike pattern was confirmed for each runner using a motion capture system. We obtained high resolution peripheral computed tomography scans of the posterior calcaneus for both runners and non-runners. No statistically significant differences were found between runners and nonrunners or forefoot strikers and rearfoot strikers. Mean trabecular thickness and mineral density were greatest in forefoot runners with strong effect sizes (<0.80. Trabecular thickness was positively correlated with weekly running distance (r2 = 0.417, p<0.05 and years running (r2 = 0.339, p<0.05 and negatively correlated with age at onset of running (r2 = 0.515, p<0.01 Trabecular thickness, mineral density and bone volume ratio of nonrunners were highly correlated with body mass (r2 = 0.824, p<0.05 and nonrunners were significantly heavier than runners (p<0.05. Adjusting for body mass revealed significantly thicker trabeculae in the posterior calcaneus of forefoot strikers, likely an artifact of greater running volume and earlier onset of running in this subgroup; thus, individuals with the greatest summative loading stimulus had, after body mass adjustment, the thickest trabeculae. Further study with larger sample sizes is necessary to elucidate the role of footstrike on calcaneal trabecular structure. To our knowledge, intraspecific body mass correlations with measures of trabecular robusticity have not been reported elsewhere. We hypothesize that early adoption of running and years of sustained moderate volume running stimulate bone modeling in trabeculae of the

  17. Analyses of musculoskeletal interactions in humans by quantitative computed tomography (QCT)

    International Nuclear Information System (INIS)

    Capiglioni, Ricardo; Cointry, Gustavo; Capozza, Ricardo; Gimenez, Carlos; Ferretti, Jose L.

    2001-01-01

    Bone and muscle cross-sectional properties were assessed by QCT at the L3 spinal level in normal women and men (n=93/5) aged 32-74 years and compared with the kyphosis angle (Ka) determined between T4 and T12 in lateral Rx's. The volumetric mineral density (vBMD) of trabecular bone, the bone mineral content (BMC) of the vertebral bodies and the fat-free areas of the peri spinal muscle (FFMA) varied in line and correlated negatively with the Ka. Multiple regression analyses showed that the trabecular vBMD and total BMC were the most significant independent determinants of the Ka, and that the FFMA and time since menopause were the only independent determinants of the bone properties, with no influence of the gender, age or anthropometric factors. (author)

  18. Trabecular bone in the calcaneus of runners.

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    Best, Andrew; Holt, Brigitte; Troy, Karen; Hamill, Joseph

    2017-01-01

    Trabecular bone of the human calcaneus is subjected to extreme repetitive forces during endurance running and should adapt in response to this strain. To assess possible bone functional adaptation in the posterior region of the calcaneus, we recruited forefoot-striking runners (n = 6), rearfoot-striking runners (n = 6), and non-runners (n = 6), all males aged 20-41 for this institutionally approved study. Foot strike pattern was confirmed for each runner using a motion capture system. We obtained high resolution peripheral computed tomography scans of the posterior calcaneus for both runners and non-runners. No statistically significant differences were found between runners and nonrunners or forefoot strikers and rearfoot strikers. Mean trabecular thickness and mineral density were greatest in forefoot runners with strong effect sizes (forefoot strikers, likely an artifact of greater running volume and earlier onset of running in this subgroup; thus, individuals with the greatest summative loading stimulus had, after body mass adjustment, the thickest trabeculae. Further study with larger sample sizes is necessary to elucidate the role of footstrike on calcaneal trabecular structure. To our knowledge, intraspecific body mass correlations with measures of trabecular robusticity have not been reported elsewhere. We hypothesize that early adoption of running and years of sustained moderate volume running stimulate bone modeling in trabeculae of the posterior calcaneus.

  19. Alterations of bone density, microstructure, and strength of the distal radius in male patients with rheumatoid arthritis: a case-control study with HR-pQCT.

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    Zhu, Tracy Y; Griffith, James F; Qin, Ling; Hung, Vivian W; Fong, Tsz-Ning; Au, Sze-Ki; Li, Martin; Lam, Yvonne Yi-On; Wong, Chun-Kwok; Kwok, Anthony W; Leung, Ping-Chung; Li, Edmund K; Tam, Lai-Shan

    2014-09-01

    In this cross-sectional study, we investigated volumetric bone mineral density (vBMD), bone microstructure, and biomechanical competence of the distal radius in male patients with rheumatoid arthritis (RA). The study cohort comprised 50 male RA patients of average age of 61.1 years and 50 age-matched healthy males. Areal BMD (aBMD) of the hip, lumbar spine, and distal radius was measured by dual-energy X-ray absorptiometry. High-resolution peripheral quantitative computed tomography (HR-pQCT) of the distal radius provided measures of cortical and trabecular vBMD, microstructure, and biomechanical indices. aBMD of the hip but not the lumbar spine or ultradistal radius was significantly lower in RA patients than controls after adjustment for body weight. Total, cortical, and trabecular vBMD at the distal radius were, on average, -3.9% to -23.2% significantly lower in RA patients, and these differences were not affected by adjustment for body weight, testosterone level, or aBMD at the ultradistal radius. Trabecular microstructure indices were, on average, -8.1% (trabecular number) to 28.7% (trabecular network inhomogeneity) significantly inferior, whereas cortical pore volume and cortical porosity index were, on average, 80.3% and 63.9%, respectively, significantly higher in RA patients. RA patients also had significantly lower whole-bone stiffness, modulus, and failure load, with lower and more unevenly distributed cortical and trabecular stress. Density and microstructure indices significantly correlated with disease activity, severity, and levels of pro-inflammatory cytokines (interleukin [IL] 12p70, tumor necrosis factor, IL-6 and IL-1β). Ten RA patients had focal periosteal bone apposition most prominent at the ulnovolar aspect of the distal radius. These patients had shorter disease duration and significantly higher cortical porosity. In conclusion, HR-pQCT reveals significant alterations of bone density, microstructure, and strength of the distal radius in

  20. Fisiología trabecular y glaucoma de ángulo abierto Trabecular physiology and open angle glaucoma

    Directory of Open Access Journals (Sweden)

    Yoanner Martín Perera

    2012-01-01

    Full Text Available El glaucoma constituye una de las enfermedades oculares más frecuentes en el mundo. Su etiología es variada, pero el problema radica generalmente en la evacuación del humor acuoso a nivel de la red trabecular y del canal de Schlemm. Se realizó una revisión bibliográfica sobre los principales mecanismos envueltos en la función trabecular: capacidad fagocítica de las células trabeculares, regulación de la composición de la matriz extracelular, contracción-relajación de las células trabeculares y los cambios en su volumen y forma. Un mayor conocimiento de la fisiología trabecular y su relación con la fisiopatología del glaucoma permitirá un mejor manejo de la enfermedad, así como el desarrollo de nuevos fármacos que tengan como diana la vía trabecular de manera selectiva y que permitan evitar los efectos secundarios relacionados con el empleo de medicamentos poco específicos.Glaucoma is one of the most common eye diseases worldwide, but usually the problem lies in the evacuation of aqueous humor at the trabecular meshwork and Schlemm's canal. A literature review was made about the main mechanisms involved in the trabecular function: the phagocytic capacity of trabecular cells, the regulation of the extracellular matrix composition, the contraction-relaxation of trabecular cells and the changes in their volume and shape. A better understanding of the trabecular physiology and the pathophysiology of glaucoma will allow better disease management and development of new drugs that have as their target the trabecular pathway in a selective way and that avoid the side effects associated with the use of nonspecific drugs.

  1. Trabecular bone structure correlates with hand posture and use in hominoids.

    Directory of Open Access Journals (Sweden)

    Zewdi J Tsegai

    Full Text Available Bone is capable of adapting during life in response to stress. Therefore, variation in locomotor and manipulative behaviours across extant hominoids may be reflected in differences in trabecular bone structure. The hand is a promising region for trabecular analysis, as it is the direct contact between the individual and the environment and joint positions at peak loading vary amongst extant hominoids. Building upon traditional volume of interest-based analyses, we apply a whole-epiphysis analytical approach using high-resolution microtomographic scans of the hominoid third metacarpal to investigate whether trabecular structure reflects differences in hand posture and loading in knuckle-walking (Gorilla, Pan, suspensory (Pongo, Hylobates and Symphalangus and manipulative (Homo taxa. Additionally, a comparative phylogenetic method was used to analyse rates of evolutionary changes in trabecular parameters. Results demonstrate that trabecular bone volume distribution and regions of greatest stiffness (i.e., Young's modulus correspond with predicted loading of the hand in each behavioural category. In suspensory and manipulative taxa, regions of high bone volume and greatest stiffness are concentrated on the palmar or distopalmar regions of the metacarpal head, whereas knuckle-walking taxa show greater bone volume and stiffness throughout the head, and particularly in the dorsal region; patterns that correspond with the highest predicted joint reaction forces. Trabecular structure in knuckle-walking taxa is characterised by high bone volume fraction and a high degree of anisotropy in contrast to the suspensory brachiators. Humans, in which the hand is used primarily for manipulation, have a low bone volume fraction and a variable degree of anisotropy. Finally, when trabecular parameters are mapped onto a molecular-based phylogeny, we show that the rates of change in trabecular structure vary across the hominoid clade. Our results support a link

  2. Vertebral body trabecular density at the thoracolumbar junction using quantitative computed tomography

    International Nuclear Information System (INIS)

    Singer, K.P.; Breidahl, P.D.; Royal Perth Hospital

    1990-01-01

    Quantitative computed tomography was used to assess vertebral trabecular density in 26 post-mortem spines from individuals aged between 14 and 80 years. All vertebrae from T10 to L1 were scanned transversely near the mid-vertebral level with calculations of trabecular density in HUs averaged and referenced to a mineral equivalent phantom. An age-related decline in trabecular density was recorded (r=0.55, p<0.0001). Density measures from the anterior aspect of the vertebral body were significantly greater than from postero-lateral regions. From T10 to L1, there was a significant decrease in trabecular density, whereas density measures multiplied by vertebral body cross-sectional area were constant. Predictions of vertebral compressive strength using quantitative computed tomography may become more accurate by increasing the sampling area per scan and including vertebral body cross-sectional area as part of the radiologic assessment. (orig.)

  3. Unique effects of energy versus estrogen deficiency on multiple components of bone strength in exercising women.

    Science.gov (United States)

    Southmayd, E A; Mallinson, R J; Williams, N I; Mallinson, D J; De Souza, M J

    2017-04-01

    Many female athletes are energy and/or estrogen deficient, but the independent effects on bone health have not been isolated. Energy deficiency was detrimental at the tibia while estrogen deficiency was detrimental at the radius. Nutrition must be considered alongside menstrual recovery when addressing compromised bone health in female athletes. The purpose of this study was to describe volumetric bone mineral density (vBMD), bone geometry, and estimated bone strength in exercising women (n = 60) grouped according to energy status (energy replete (EnR: n = 30) vs. energy deficient (EnD: n = 30)) and estrogen status (estrogen replete (E 2 R: n = 33) vs. estrogen deficient (E 2 D: n = 27)), resulting in four distinct groups: EnR + E 2 R (n = 17), EnR + E 2 D (n = 13), EnD + E 2 R (n = 16), EnD + E 2 D (n = 14). Energy status was determined using the ratio of measured to predicted resting energy expenditure (mREE/pREE). Estrogen status was based on self-reported menstrual status confirmed by daily evaluation of urinary estrone-1-glucoronide (E1G), pregnanediol glucuronide (PdG), and luteinizing hormone (LH). Eumenorrheic women were considered E 2 R, amenorrheic women were E 2 D, and oligomenorrheic women were categorized based on history of menses in the past year. Bone was assessed using peripheral quantitative computed tomography (pQCT). EnD women exhibited lower total vBMD, trabecular vBMD, cortical area, and BSI at the distal tibia and lower total vBMD, smaller cortical area and cortical thickness, and larger endosteal circumference at the proximal tibia compared to EnR women (p < 0.042). E 2 D women had lower total and cortical vBMD, larger total and trabecular area, and lower BSI at the distal radius and lower cortical vBMD at the proximal radius compared to E 2 R women (p < 0.023). Energy and estrogen interacted to affect total and trabecular area at the distal tibia (p < 0.021). Efforts to correct energy deficiency, which in turn may

  4. Mucopolysaccharides in the trabecular meshwork

    International Nuclear Information System (INIS)

    Ohnishi, Yoshitaka; Yamana, Yasuo; Abe, Masahiro

    1982-01-01

    The localization of 35 S-sulfate and 3 H-glucosamine in the trabecular region of the hamster was studied by light and electron microscopic autoradiography after the intraperitoneal injection. Exposed silver grains of 35 S-sulfate were concentrated in the trabecular meshwork, sclera and cornea, and grains of 35 H-glucosamine were localized in the trabecular region. The radioactivity of both isotopes was observed in the Golgi apparatuses of the endothelial cells and fibroblasts in Schlemm's canal and the trabecular meshwork. Thereafter, the grains were noted over the entire cytoplasm, except for the nucleus, and then were incorporated into the amorphous substance and collagen fibers in the juxtacanalicular connective tissue. These results suggest that endothelial cells in the trabecular region synthesize and secrete the sulfated mucopolysaccharides and hyaluronic acid. (author)

  5. The Role of Body Weight on Bone in Anorexia Nervosa

    DEFF Research Database (Denmark)

    Frølich, Jacob; Hansen, Stinus; Winkler, Laura Al-Dakhiel

    2017-01-01

    Anorexia nervosa (AN) is associated with decreased bone mineral density and increased risk of fracture. The aim of this study was to assess bone geometry, volumetric bone mineral density (vBMD), trabecular microarchitecture and estimated failure load in weight-bearing vs. non-weight-bearing bones...

  6. Complete volumetric decomposition of individual trabecular plates and rods and its morphological correlations with anisotropic elastic moduli in human trabecular bone.

    Science.gov (United States)

    Liu, X Sherry; Sajda, Paul; Saha, Punam K; Wehrli, Felix W; Bevill, Grant; Keaveny, Tony M; Guo, X Edward

    2008-02-01

    Trabecular plates and rods are important microarchitectural features in determining mechanical properties of trabecular bone. A complete volumetric decomposition of individual trabecular plates and rods was used to assess the orientation and morphology of 71 human trabecular bone samples. The ITS-based morphological analyses better characterize microarchitecture and help predict anisotropic mechanical properties of trabecular bone. Standard morphological analyses of trabecular architecture lack explicit segmentations of individual trabecular plates and rods. In this study, a complete volumetric decomposition technique was developed to segment trabecular bone microstructure into individual plates and rods. Contributions of trabecular type-associated morphological parameters to the anisotropic elastic moduli of trabecular bone were studied. Seventy-one human trabecular bone samples from the femoral neck (FN), tibia, and vertebral body (VB) were imaged using muCT or serial milling. Complete volumetric decomposition was applied to segment trabecular bone microstructure into individual plates and rods. The orientation of each individual trabecula was determined, and the axial bone volume fractions (aBV/TV), axially aligned bone volume fraction along each orthotropic axis, were correlated with the elastic moduli. The microstructural type-associated morphological parameters were derived and compared with standard morphological parameters. Their contributions to the anisotropic elastic moduli, calculated by finite element analysis (FEA), were evaluated and compared. The distribution of trabecular orientation suggested that longitudinal plates and transverse rods dominate at all three anatomic sites. aBV/TV along each axis, in general, showed a better correlation with the axial elastic modulus (r(2) = 0.95 approximately 0.99) compared with BV/TV (r(2) = 0.93 approximately 0.94). The plate-associated morphological parameters generally showed higher correlations with the

  7. Defects in cortical microarchitecture among African-American women with type 2 diabetes.

    Science.gov (United States)

    Yu, E W; Putman, M S; Derrico, N; Abrishamanian-Garcia, G; Finkelstein, J S; Bouxsein, M L

    2015-02-01

    Patients with type 2 diabetes mellitus (DM2) have increased fracture risk. We found that African-American women with DM2 have increased cortical porosity and lower cortical bone density at the radius than non-diabetic controls. These cortical deficits are associated with hyperglycemia and may contribute to skeletal fragility associated with DM2. Fracture risk is increased in patients with type 2 diabetes mellitus (DM2) despite normal areal bone mineral density (aBMD). DM2 is more common in African-Americans than in Caucasians. It is not known whether African-American women with DM2 have deficits in bone microstructure. We measured aBMD at the spine and hip by DXA, and volumetric BMD (vBMD) and microarchitecture at the distal radius and tibia by HR-pQCT in 22 DM2 and 78 non-diabetic African-American women participating in the Study of Women Across the Nation (SWAN). We also measured fasting glucose and HOMA-IR. Age, weight, and aBMD at all sites were similar in both groups. At the radius, cortical porosity was 26% greater, while cortical vBMD and tissue mineral density were lower in women with DM2 than in controls. There were no differences in radius total vBMD or trabecular vBMD between groups. Despite inferior cortical bone properties at the radius, FEA-estimated failure load was similar between groups. Tibia vBMD and microarchitecture were also similar between groups. There were no significant associations between cortical parameters and duration of DM2 or HOMA-IR. However, among women with DM2, higher fasting glucose levels were associated with lower cortical vBMD (r=-0.54, p=0.018). DM2 and higher fasting glucose are associated with unfavorable cortical bone microarchitecture at the distal radius in African-American women. These structural deficits may contribute to the increased fracture risk among women with DM2. Further, our results suggest that hyperglycemia may be involved in mechanisms of skeletal fragility associated with DM2.

  8. Relationship of bony trabecular characteristics and age to bone mass

    International Nuclear Information System (INIS)

    Choi, Dong Hoon; Song, Young Han; Yoon, Young Nam; Lee, Wan; Lee, Byung Do

    2006-01-01

    Bony strength is dependent on bone mass and bony structure. So this study was designed to investigate the relationship between the bone mass and bony mass and bony trabecular characteristics. Study subjects were 51 females (average age 68.6 years) and 20 males (average age 66.4 years). Bony mineral density (BMD, grams/cm 2 ) of proximal femur was measured by a dual energy X-ray absorptiometry (DEXA). Regions of interest (ROIs) were selected from the digitized radiographs of proximal femur. A customized computer program processed morphologic operations (MO) of ROIs. 44 skeletal variables of MO were calculated from ROIs on the Ward's triangle and greater trochanter of femur. WHO BMD classes were predicted by MO variables of the same ROI. Classification and Regression Tree analysis was used for calculating weighted kappa values, sensitivity and specificity of MO. The discriminating factors of morphologic operation were branch point, branch point [per cm sq]. Age also played important role in distinguishing osteoporotic classes. The sensitivity of MO at Ward's triangle and Greater Trochanter was 91.8%, 65.6%, respectively. The specificity of MO was 100% at Ward's triangle and Greater Trochanter. Bony trabecular characteristics obtained using radiological bone morphometric analysis seem to be related to bone mass

  9. Biomechanics and Mechanobiology of Trabecular Bone: A Review

    Science.gov (United States)

    Oftadeh, Ramin; Perez-Viloria, Miguel; Villa-Camacho, Juan C.; Vaziri, Ashkan; Nazarian, Ara

    2015-01-01

    Trabecular bone is a highly porous, heterogeneous, and anisotropic material which can be found at the epiphyses of long bones and in the vertebral bodies. Studying the mechanical properties of trabecular bone is important, since trabecular bone is the main load bearing bone in vertebral bodies and also transfers the load from joints to the compact bone of the cortex of long bones. This review article highlights the high dependency of the mechanical properties of trabecular bone on species, age, anatomic site, loading direction, and size of the sample under consideration. In recent years, high resolution micro finite element methods have been extensively used to specifically address the mechanical properties of the trabecular bone and provide unique tools to interpret and model the mechanical testing experiments. The aims of the current work are to first review the mechanobiology of trabecular bone and then present classical and new approaches for modeling and analyzing the trabecular bone microstructure and macrostructure and corresponding mechanical properties such as elastic properties and strength. PMID:25412137

  10. Effects of total gastrectomy on plasma silicon and amino acid concentrations in men.

    Science.gov (United States)

    Tatara, Marcin R; Krupski, Witold; Szpetnar, Maria; Dąbrowski, Andrzej; Bury, Paweł; Szabelska, Anna; Charuta, Anna; Boguszewska-Czubara, Anna; Maciejewski, Ryszard; Wallner, Grzegorz

    2015-12-01

    The aim of the study was to determine one-year effects of total gastrectomy on plasma silicon and free amino acid concentrations in patients and evaluate changes of volumetric bone mineral density (vBMD) in lumbar spine. Eight patients were enrolled to the control (CTR) group. Six patients subjected to total gastrectomy (GX group) were included to the experimental group. vBMD in trabecular and cortical bone was measured in lumbar vertebrae at baseline (before surgery) and one year later using quantitative computed tomography. Plasma concentrations of silicon and free amino acids were determined at baseline and one year later using photometric method and ion-exchange chromatography. Body weights within CTR and GX groups were not different after one-year follow-up when compared to the baseline values (P > 0.05). An average annual decrease of vBMD in the trabecular bone in the gastrectomized patients reached 15.0% in lumbar spine and was significantly different in comparison to the percentage changes observed in CTR group (P = 0.02). One-year percentage change of vBMD in the cortical bone in L1 and L2 has shown significantly decreased values by 10.5 and 9.1% in the GX group when compared to the percentage change observed in the controls (P silicon was significantly lowered by 26.7% one year after the total gastrectomy when compared to the baseline value (P = 0.009). Total gastrectomy in patients has induced severe osteoporotic changes in lumbar spine within one-year period. The observed osteoporotic changes were associated with decreased plasma concentration of silicon indicating importance of exocrine and endocrine functions of stomach for silicon homeostasis maintenance. Gastrectomy-induced bone loss was not related to decreased amino acid concentration in plasma obtained from overnight fasted patients. © 2015 by the Society for Experimental Biology and Medicine.

  11. Relationship of total body fat mass to weight-bearing bone volumetric density, geometry, and strength in young girls.

    Science.gov (United States)

    Farr, Joshua N; Chen, Zhao; Lisse, Jeffrey R; Lohman, Timothy G; Going, Scott B

    2010-04-01

    Understanding the influence of total body fat mass (TBFM) on bone during the peri-pubertal years is critical for the development of future interventions aimed at improving bone strength and reducing fracture risk. Thus, we evaluated the relationship of TBFM to volumetric bone mineral density (vBMD), geometry, and strength at metaphyseal and diaphyseal sites of the femur and tibia of young girls. Data from 396 girls aged 8-13 years from the "Jump-In: Building Better Bones" study were analyzed. Bone parameters were assessed using peripheral quantitative computed tomography (pQCT) at the 4% and 20% distal femur and 4% and 66% distal tibia of the non-dominant leg. Bone parameters at the 4% sites included trabecular vBMD, periosteal circumference, and bone strength index (BSI), while at the 20% femur and 66% tibia, parameters included cortical vBMD, periosteal circumference, and strength-strain index (SSI). Multiple linear regression analyses were used to assess associations between bone parameters and TBFM, controlling for muscle cross-sectional area (MCSA). Regression analyses were then repeated with maturity, bone length, physical activity, and ethnicity as additional covariates. Analysis of covariance (ANCOVA) was used to compare bone parameters among tertiles of TBFM. In regression models with TBFM and MCSA, associations between TBFM and bone parameters at all sites were not significant. TBFM explained very little variance in all bone parameters (0.2-2.3%). In contrast, MCSA was strongly related (p<0.001) to all bone parameters, except cortical vBMD. The addition of maturity, bone length, physical activity, and ethnicity did not alter the relationship between TBFM and bone parameters. With bone parameters expressed relative to total body mass, ANCOVA showed that all outcomes were significantly (p<0.001) greater in the lowest compared to the middle and highest tertiles of TBFM. Although TBFM is correlated with femur and tibia vBMD, periosteal circumference, and

  12. Mechanical properties of femoral trabecular bone in dogs

    Directory of Open Access Journals (Sweden)

    Nolte Ingo

    2005-03-01

    Full Text Available Abstract Background Studying mechanical properties of canine trabecular bone is important for a better understanding of fracture mechanics or bone disorders and is also needed for numerical simulation of canine femora. No detailed data about elastic moduli and degrees of anisotropy of canine femoral trabecular bone has been published so far, hence the purpose of this study was to measure the elastic modulus of trabecular bone in canine femoral heads by ultrasound testing and to assess whether assuming isotropy of the cancellous bone in femoral heads in dogs is a valid simplification. Methods From 8 euthanized dogs, both femora were obtained and cubic specimens were cut from the centre of the femoral head which were oriented along the main pressure and tension trajectories. The specimens were tested using a 100 MHz ultrasound transducer in all three orthogonal directions. The directional elastic moduli of trabecular bone tissue and degrees of anisotropy were calculated. Results The elastic modulus along principal bone trajectories was found to be 11.2 GPa ± 0.4, 10.5 ± 2.1 GPa and 10.5 ± 1.8 GPa, respectively. The mean density of the specimens was 1.40 ± 0.09 g/cm3. The degrees of anisotropy revealed a significant inverse relationship with specimen densities. No significant differences were found between the elastic moduli in x, y and z directions, suggesting an effective isotropy of trabecular bone tissue in canine femoral heads. Discussion This study presents detailed data about elastic moduli of trabecular bone tissue obtained from canine femoral heads. Limitations of the study are the relatively small number of animals investigated and the measurement of whole specimen densities instead of trabecular bone densities which might lead to an underestimation of Young's moduli. Publications on elastic moduli of trabecular bone tissue present results that are similar to our data. Conclusion This study provides data about directional elastic

  13. Decrease in local volumetric bone mineral density (vBMD) in osteoarthritic joints is associated with the increase in cartilage damage: a pQCT study

    Science.gov (United States)

    Tamaddon, Maryam; Chen, Shen Mao; Vanaclocha, Leyre; Hart, Alister; El-Husseiny, Moataz; Henckel, Johann; Liu, Chaozong

    2017-11-01

    Osteoarthritis (OA) is the most common type of arthritis and a major cause of disability in the adult population. It affects both cartilage and subchondral bone in the joints. There has been some progress in understanding the changes in subchondral bone with progression of osteoarthritis. However, local changes in subchondral bone such as microstructure or volumetric bone mineral density in connection with the defect in cartilage are relatively unexplored. To develop an effective treatment for progression of OA, it is important to understand how the physical environment provided by the subchondral bone affects the overlying cartilage. In this study we examined the volumetric bone mineral density (vBMD) distribution in the osteoarthritic joint tissues obtained from total hip replacement surgeries due to osteoarthritis, using peripheral quantitative CT (pQCT). It was found that there is a significant decrease in volumetric bone mineral density, which co-localises with the damage in the overlying cartilage. This was not limited to the subchondral bone immediately adjacent to the cartilage defect but continued in the layers below. Bone resorption and cyst formation in the OA tissues were also detected. We observed that the bone surrounding subchondral bone cysts exhibited much higher volumetric bone mineral density than that of the surrounding bones. PQCT was able to detect significant changes in vBMD between OA and non-OA samples, as well as between areas of different cartilage degeneration, which points to its potential as a technique for detection of early OA.

  14. Mucopolysaccharides in the trabecular meshwork. Light and electron microscopic autoradiography

    Energy Technology Data Exchange (ETDEWEB)

    Ohnishi, Yoshitaka; Yamana, Yasuo; Abe, Masahiro (Kyushu Univ., Fukuoka (Japan). Faculty of Medicine)

    1982-09-01

    The localization of /sup 35/S-sulfate and /sup 3/H-glucosamine in the trabecular region of the hamster was studied by light and electron microscopic autoradiography after the intraperitoneal injection. Exposed silver grains of /sup 35/S-sulfate were concentrated in the trabecular meshwork, sclera and cornea, and grains of /sup 35/H-glucosamine were localized in the trabecular region. The radioactivity of both isotopes was observed in the Golgi apparatuses of the endothelial cells and fibroblasts in Schlemm's canal and the trabecular meshwork. Thereafter, the grains were noted over the entire cytoplasm, except for the nucleus, and then were incorporated into the amorphous substance and collagen fibers in the juxtacanalicular connective tissue. These results suggest that endothelial cells in the trabecular region synthesize and secrete the sulfated mucopolysaccharides and hyaluronic acid.

  15. 3D Architecture of Trabecular Bone in the Pig Mandible and Femur: Inter-Trabecular Angle Distributions.

    Science.gov (United States)

    Ben-Zvi, Yehonatan; Reznikov, Natalie; Shahar, Ron; Weiner, Steve

    2017-09-01

    Cancellous bone is an intricate network of interconnected trabeculae, to which analysis of network topology can be applied. The inter-trabecular angle (ITA) analysis - an analysis of network topological parameters and regularity of network-forming nodes, was previously carried out on human proximal femora and showed that trabecular bone follows two main principles: sparsity of the network connectedness (prevalence of nodes with low connectivity in the network) and maximal space spanning (angular offset of connected elements is maximal for their number and approximates the values of geometrically symmetric shapes). These observations suggest that 3D organization of trabecular bone, irrespective of size and shape of individual elements, reflects a tradeoff between minimal metabolic cost of maintenance and maximal network stability under conditions of multidirectional loading. In this study we validate the ITA application using additional 3D structures (cork and 3D-printed metal lattices), analyze the ITA parameters in porcine proximal femora and mandibles and carry out a spatial analysis of the most common node type in the porcine mandibular condyle. The validation shows that the ITA application reliably detects designed or evolved topological parameters. The ITA parameters of porcine trabecular bones are similar to those of human bones. We demonstrate functional adaptation in the pig mandibular condyle by showing that the planar nodes with 3 edges are preferentially aligned in relation to the muscle forces that are applied to the condyle. We conclude that the ITA topological parameters are remarkable conserved, but locally do adapt to applied stresses.

  16. 3D Architecture of Trabecular Bone in the Pig Mandible and Femur: Inter-Trabecular Angle Distributions

    Directory of Open Access Journals (Sweden)

    Yehonatan Ben-Zvi

    2017-09-01

    Full Text Available Cancellous bone is an intricate network of interconnected trabeculae, to which analysis of network topology can be applied. The inter-trabecular angle (ITA analysis—an analysis of network topological parameters and regularity of network-forming nodes—was previously carried out on human proximal femora and showed that trabecular bone follows two main principles: sparsity of the network connectedness (prevalence of nodes with low connectivity in the network and maximal space spanning (angular offset of connected elements is maximal for their number and approximates the values of geometrically symmetric shapes. These observations suggest that 3D organization of trabecular bone, irrespective of size and shape of individual elements, reflects a tradeoff between minimal metabolic cost of maintenance and maximal network stability under conditions of multidirectional loading. In this study, we validate the ITA application using additional 3D structures (cork and 3D-printed metal lattices, analyze the ITA parameters in porcine proximal femora and mandibles, and carry out a spatial analysis of the most common node type in the porcine mandibular condyle. The validation shows that the ITA application reliably detects designed or evolved topological parameters. The ITA parameters of porcine trabecular bones are similar to those of human bones. We demonstrate functional adaptation in the pig mandibular condyle by showing that the planar nodes with three edges are preferentially aligned in relation to the muscle forces that are applied to the condyle. We conclude that the ITA topological parameters are remarkably conserved, but locally do adapt to applied stresses.

  17. Genetic Dissection of Trabecular Bone Structure with Mouse Intersubspecific Consomic Strains

    Directory of Open Access Journals (Sweden)

    Taro Kataoka

    2017-10-01

    Full Text Available Trabecular bone structure has an important influence on bone strength, but little is known about its genetic regulation. To elucidate the genetic factor(s regulating trabecular bone structure, we compared the trabecular bone structures of two genetically remote mouse strains, C57BL/6J and Japanese wild mouse-derived MSM/Ms. Phenotyping by X-ray micro-CT revealed that MSM/Ms has structurally more fragile trabecular bone than C57BL/6J. Toward identification of genetic determinants for the difference in fragility of trabecular bone between the two mouse strains, we employed phenotype screening of consomic mouse strains in which each C57BL/6J chromosome is substituted by its counterpart from MSM/Ms. The results showed that many chromosomes affect trabecular bone structure, and that the consomic strain B6-Chr15MSM, carrying MSM/Ms-derived chromosome 15 (Chr15, has the lowest values for the parameters BV/TV, Tb.N, and Conn.D, and the highest values for the parameters Tb.Sp and SMI. Subsequent phenotyping of subconsomic strains for Chr15 mapped four novel trabecular bone structure-related QTL (Tbsq1-4 on mouse Chr15. These results collectively indicate that genetic regulation of trabecular bone structure is highly complex, and that even in the single Chr15, the combined action of the four Tbsqs controls the fragility of trabecular bone. Given that Tbsq4 is syntenic to human Chr 12q12-13.3, where several bone-related SNPs are assigned, further study of Tbsq4 should facilitate our understanding of the genetic regulation of bone formation in humans.

  18. Age variations in the properties of human tibial trabecular bone and cartilage

    DEFF Research Database (Denmark)

    Ding, Ming

    2000-01-01

    , such as apparent, apparent ash and collagen densities of human tibial trabecular bone have significant relationships with age. Tissue density and mineral concentration remain constant throughout life. Trabecular bone is tougher in the younger age, i.e. fracture requires more energy. Collagen density was the single......Initiated and motivated by clinical and scientific problems such as age-related bone fracture, prosthetic loosening, bone remodeling, and degenerative bone diseases, much significant research on the properties of trabecular bone has been carried out over the last two decades. This work has mainly...... focused on the central vertebral trabecular bone, while little is known about age-related changes in the properties of human peripheral (tibial) trabecular bone. Knowledge of the properties of peripheral (tibial) trabecular bone is of major importance for the understanding of degenerative diseases...

  19. A trabecular metal implant 4 months after placement: clinical-histologic case report.

    Science.gov (United States)

    Spinato, Sergio; Zaffe, Davide; Felice, Pietro; Checchi, Luigi; Wang, Hom-Lay

    2014-02-01

    The aim of this case report was to histologically evaluate the behavior of a trabecular metal (TM) implant composed of titanium and spatial 3-dimensional tantalum (Ta) trabeculae. This study is the first human histologic case report of this implant. A TM implant was placed in a 54-year-old woman exhibiting moderate chronic periodontitis. After periodontal treatment, the implant was inserted under favorable clinical conditions. Patient was not seen for 4 months because of unrelated breast reduction surgery. At the surgical reopening, periimplant inflammation affecting the coronal third of the implant was observed 4 months after implant placement. With patient's consent, the implant was removed for histologic analysis. Histology highlighted a greater amount of bone in close contact with Ta trabeculae than titanium surfaces. The finding of bone formation around the Ta trabeculae suggests that trabecular metal material promotes bone ingrowth for secondary implant stability. Additional evidence is needed to confirm this observation.

  20. Bone Status Among Patients With Nonsurgical Hypoparathyroidism, Autosomal Dominant Hypocalcaemia, and Pseudohypoparathyroidism: A Cohort Study.

    Science.gov (United States)

    Underbjerg, Line; Malmstroem, Sofie; Sikjaer, Tanja; Rejnmark, Lars

    2018-03-01

    Nonsurgical hypoparathyroidism (Ns-HypoPT) and pseudohypoparathyroidism (PHP) are both rare diseases, characterized by hypocalcemia. In Ns-HypoPT, PTH levels are low, whereas patients with PHP often have very high levels due to receptor-insensitivity to PTH (PTH-resistance). Accordingly, we hypothesized that indices of bone turnover and bone mineralization/architecture are similar in Ns-HypoPT and PHP despite marked differences in PTH levels. We studied 62 patients with Ns-HypoPT and 31 with PHP as well as a group of age- and sex-matched healthy controls. We found a significantly higher areal BMD (aBMD) by DXA among patients with Ns-HypoPT, both compared with PHP and the background population. Compared with Ns-HypoPT, PHP patients had significantly lower total and trabecular volumetric BMD (vBMD) assessed by quantitative computed tomography (QCT) scans at the spine and hip. High-resolution peripheral quantitative computed tomography (HRpQCT) scans showed a lower trabecular area and vBMD as well as a lower trabecular number at the tibia in PHP compared to Ns-HypoPT and matched controls. In PHP, PTH levels correlated with levels of markers of bone formation (osteocalcin, bone-specific alkaline phosphatase, P1NP), and bone resorption (CTx). In adult males, levels of bone markers were significantly higher in PHP compared with Ns-HypoPT. Levels of procalcitonin and calcitonin were significantly higher in PHP compared with Ns-HypoPT. In conclusion, indices of bone turnover, density, and microarchitecture differ between patients with Ns-HypoPT and PHP. Our data suggest that patients with PHP do not have a complete skeletal resistance to PTH and that the effects of chronically high PTH levels in PHP are mostly confined to the trabecular tissue. © 2017 American Society for Bone and Mineral Research. © 2017 American Society for Bone and Mineral Research.

  1. Dipeptidyl Peptidase-4 Inhibitor, Vildagliptin, Improves Trabecular Bone Mineral Density and Microstructure in Obese, Insulin-Resistant, Pre-diabetic Rats.

    Science.gov (United States)

    Charoenphandhu, Narattaphol; Suntornsaratoon, Panan; Sa-Nguanmoo, Piangkwan; Tanajak, Pongpan; Teerapornpuntakit, Jarinthorn; Aeimlapa, Ratchaneevan; Chattipakorn, Nipon; Chattipakorn, Siriporn

    2018-02-02

    Obese insulin resistance and type 2 diabetes mellitus profoundly impair bone mechanical properties and bone quality. However, because several antidiabetes drugs, especially thiazolidinediones, further aggravate bone loss in individuals with diabetes, diabetic osteopathy should not be treated by using simply any glucose-lowering agents. Recently, incretins have been reported to affect osteoblast function positively. The present study aimed to investigate the effects of vildagliptin, an inhibitor of dipeptidyl peptidase-4, on bone of rats with high-fat-diet-induced prediabetes. Male rats were fed a high-fat diet for 12 weeks to induce obese insulin resistance and then treated with vildagliptin for 4 weeks. The effects of the drug on bone were determined by microcomputed tomography and bone histomorphometry. Vildagliptin markedly improved insulin resistance in these obese insulin-resistant rats. It also significantly increased volumetric bone mineral density. Specifically, vildagliptin-treated obese insulin-resistant rats exhibited higher trabecular volumetric bone mineral density than vehicle-treated obese insulin-resistant rats, whereas cortical volumetric bone mineral density, cortical thickness and area were not changed. Bone histomorphometric analysis in a trabecular-rich area (i.e. tibial metaphysis) revealed greater trabecular bone volume and number and less trabecular separation without change in trabecular thickness, osteocyte lacunar area or cortical thickness in the vildagliptin-treated group. Vildagliptin had a beneficial effect on the bone of obese insulin-resistant rats with prediabetes, particularly at the trabecular site. Such benefit probably results from enhanced bone formation rather than from suppressed bone resorption. Copyright © 2018 Diabetes Canada. Published by Elsevier Inc. All rights reserved.

  2. Defining the bone morphometry, micro-architecture and volumetric density profile in osteopenic vs non-osteopenic adolescent idiopathic scoliosis.

    Science.gov (United States)

    Wang, Zhi-Wei; Lee, Wayne Yuk-Wai; Lam, Tsz-Ping; Yip, Benjamin Hon-Kei; Yu, Fiona Wai-Ping; Yu, Wing-Sze; Zhu, Feng; Ng, Bobby Kin-Wah; Qiu, Yong; Cheng, Jack Chun-Yiu

    2017-06-01

    Osteopenia has been widely reported in about 30 % of girls with adolescent idiopathic scoliosis (AIS). However, the bone quality profile of the 70 % non-osteopenic AIS defined by areal bone mineral density (BMD) with conventional dual-energy X-ray absorptiometry (DXA) has not been adequately studied. Our purpose was to verify whether abnormal volumetric BMD (vBMD) and bone structure (morphometry and micro-architecture) also existed in the non-osteopenic AIS when compared with matched controls using both DXA and high-resolution peripheral computed tomography (HR-pQCT). This was a case-control cross-sectional study. 257 AIS girls with a mean age of 12.7 (SD = 0.8) years old and 187 age- and gender-matched normal controls with an average age of 12.9 (SD = 0.5) years old were included. Areal BMD (aBMD) and bone quality were measured with standard DXA and HR-pQCT, respectively. The parameters of HR-pQCT could be categorized as bone morphometry, vBMD and bone micro-architecture. The results were compared between the osteopenic AIS and osteopenic control, and between the non-osteopenic AIS and non-osteopenic control. In addition to the lower aBMD and vBMD, osteopenic AIS showed significantly greater cortical perimeter and trabecular area than the osteopenic control even after adjustments of age (P architecture and volumetric density profile compared with their normal matched controls. The observed abnormalities were suggestive of decreased endocortical bone apposition or active endocortical resorption that could affect the mechanical bone strength in AIS. The underlying pathomechanism might be attributed to abnormal bone modeling/remodeling that could be associated with the etiopathogenesis of AIS.

  3. A potential mechanism for allometric trabecular bone scaling in terrestrial mammals.

    Science.gov (United States)

    Christen, Patrik; Ito, Keita; van Rietbergen, Bert

    2015-03-01

    Trabecular bone microstructural parameters, including trabecular thickness, spacing, and number, have been reported to scale with animal size with negative allometry, whereas bone volume fraction is animal size-invariant in terrestrial mammals. As for the majority of scaling patterns described in animals, its underlying mechanism is unknown. However, it has also been found that osteocyte density is inversely related to animal size, possibly adapted to metabolic rate, which shows a negative relationship as well. In addition, the signalling reach of osteocytes is limited by the extent of the lacuno-canalicular network, depending on trabecular dimensions and thus also on animal size. Here we propose animal size-dependent variations in osteocyte density and their signalling influence distance as a potential mechanism for negative allometric trabecular bone scaling in terrestrial mammals. Using an established and tested computational model of bone modelling and remodelling, we run simulations with different osteocyte densities and influence distances mimicking six terrestrial mammals covering a large range of body masses. Simulated trabecular structures revealed negative allometric scaling for trabecular thickness, spacing, and number, constant bone volume fraction, and bone turnover rates inversely related to animal size. These results are in agreement with previous observations supporting our proposal of osteocyte density and influence distance variation as a potential mechanism for negative allometric trabecular bone scaling in terrestrial mammals. The inverse relationship between bone turnover rates and animal size further indicates that trabecular bone scaling may be linked to metabolic rather than mechanical adaptations. © 2015 Anatomical Society.

  4. Particle migration and gap healing around trabecular metal implants

    DEFF Research Database (Denmark)

    Rahbek, O; Kold, S; Zippor, Berit

    2005-01-01

    Bone on-growth and peri-implant migration of polyethylene particles were studied in an experimental setting using trabecular metal and solid metal implants. Cylindrical implants of trabecular tantalum metal and solid titanium alloy implants with a glass bead blasted surface were inserted either i...

  5. The relationship between age, rotator cuff integrity, and osseous microarchitecture of greater tuberosity: Where should we put anchor?

    Science.gov (United States)

    Kholinne, Erica; Lee, Hyun Joo; Kim, Sung Jung; Park, So Hyun; Jeon, In-Ho

    2018-01-01

    The aim of this study was to compare the microarchitecture of the greater tuberosity with or without rotator cuff tear and to obtain optimum location for anchor screw insertion for rotator cuff repair. Twenty-five humeral heads were harvested from 13 male cadavers of mean age 58.4 years, including 6 humeri with rotator cuff tear and 19 intact humeri. Six regions of interest (proximal, intermediate, and distal zones of the superficial and deep regions) were divided into the anterior (G1), middle (G2), and posterior (G3) areas of the greater tuberosity. Trabecular bone volume and cortical thickness were evaluated. Total trabecular bone volume was greater in subjects 50 years old but did not differ significantly in subjects with and without rotator cuff tear. Cortical thickness in both intact and torn rotator cuff groups was significantly greater in the proximal and intermediate zones than in the distal zone. Cortical thickness was related to anatomic location rather than age or cuff tear. The optimal location for anchor screw insertion during rotator cuff repair is either the proximal or intermediate region of the greater tuberosity. Age has more influence in terms of trabecular bone volume loss than rotator cuff integrity. Copyright © 2017. Production and hosting by Elsevier B.V.

  6. Influence of cortical endplates on ultrasonic properties of trabecular bone

    International Nuclear Information System (INIS)

    Kim, Yoon Mi; Lee, Kang Il

    2015-01-01

    The present study investigated the influence of thick cortical endplates on the ultrasonic properties of trabecular bone in a femur with a high fracture risk. Twelve trabecular bone samples were prepared from bovine femurs, and acrylic plates with thicknesses of 1.25, 1.80, and 2.75 mm were manufactured to simulate the cortical endplates using acrylic with a density and a sound speed similar to cortical bone. Although the thickness of the acrylic plates attached to the two sides of the trabecular bone increased, high correlations were observed between the speed of sound and the apparent bone density of the trabecular bone, with Pearson's correlation coefficients of 0.80-0.86. High correlations were also observed between the attenuation coefficient at 0.5 mm and the apparent bone density of the trabecular bone, with Pearson's correlation coefficients of 0.84-0.91. These results suggest that the speed of sound and attenuation coefficient at a specific frequency measured in a femur with relatively thick cortical endplates compared to the calcaneus could be used as indices for predicting the bone mineral density of the femur.

  7. Sex-specific patterns in cortical and trabecular bone microstructure in the Kirsten Skeletal Collection, South Africa.

    Science.gov (United States)

    Beresheim, Amy C; Pfeiffer, Susan K; Grynpas, Marc D; Alblas, Amanda

    2018-02-07

    The purpose of this study was to provide bone histomorphometric reference data for South Africans of the Western Cape who likely dealt with health issues under the apartheid regime. The 206 adult individuals ( n female = 75, n male = 131, mean = 47.9 ± 15.8 years) from the Kirsten Skeletal Collection, U. Stellenbosch, lived in the Cape Town metropole from the late 1960s to the mid-1990s. To study age-related changes in cortical and trabecular bone microstructure, photomontages of mid-thoracic rib cross-sections were quantitatively examined. Variables include relative cortical area (Rt.Ct.Ar), osteon population density (OPD), osteon area (On.Ar), bone volume fraction (BV/TV), trabecular number (Tb.N), trabecular thickness (Tb.Th), and trabecular spacing (Tb.Sp). All cortical variables demonstrated significant relationships with age in both sexes, with women showing stronger overall age associations. Peak bone mass was compromised in some men, possibly reflecting poor nutritional quality and/or substance abuse issues throughout adolescence and early adulthood. In women, greater predicted decrements in On.Ar and Rt.Ct.Ar suggest a structural disadvantage with age, consistent with postmenopausal bone loss. Age-related patterns in trabecular bone microarchitecture are variable and difficult to explain. Except for Tb.Th, there are no statistically significant relationships with age in women. Men demonstrate significant negative correlations between BV/TV, Tb.N, and age, and a significant positive correlation between Tb.Sp and age. This research highlights sex-specific differences in patterns of age-related bone loss, and provides context for discussion of contemporary South African bone health. While the study sample demonstrates indicators of poor bone quality, osteoporosis research continues to be under-prioritized in South Africa. © 2018 Wiley Periodicals, Inc.

  8. Anorexia Nervosa: Analysis of Trabecular Texture with CT.

    Science.gov (United States)

    Tabari, Azadeh; Torriani, Martin; Miller, Karen K; Klibanski, Anne; Kalra, Mannudeep K; Bredella, Miriam A

    2017-04-01

    Purpose To determine indexes of skeletal integrity by using computed tomographic (CT) trabecular texture analysis of the lumbar spine in patients with anorexia nervosa and normal-weight control subjects and to determine body composition predictors of trabecular texture. Materials and Methods This cross-sectional study was approved by the institutional review board and compliant with HIPAA. Written informed consent was obtained. The study included 30 women with anorexia nervosa (mean age ± standard deviation, 26 years ± 6) and 30 normal-weight age-matched women (control group). All participants underwent low-dose single-section quantitative CT of the L4 vertebral body with use of a calibration phantom. Trabecular texture analysis was performed by using software. Skewness (asymmetry of gray-level pixel distribution), kurtosis (pointiness of pixel distribution), entropy (inhomogeneity of pixel distribution), and mean value of positive pixels (MPP) were assessed. Bone mineral density and abdominal fat and paraspinal muscle areas were quantified with quantitative CT. Women with anorexia nervosa and normal-weight control subjects were compared by using the Student t test. Linear regression analyses were performed to determine associations between trabecular texture and body composition. Results Women with anorexia nervosa had higher skewness and kurtosis, lower MPP (P anorexia nervosa. Conclusion Patients with anorexia nervosa had increased skewness and kurtosis and decreased entropy and MPP compared with normal-weight control subjects. These parameters were associated with lowest lifetime weight and duration of amenorrhea, but there were no such associations with bone mineral density. These findings suggest that trabecular texture analysis might contribute information about bone health in anorexia nervosa that is independent of that provided with bone mineral density. © RSNA, 2016.

  9. Osteoarthritis alters the patellar bones subchondral trabecular architecture.

    Science.gov (United States)

    Hoechel, Sebastian; Deyhle, Hans; Toranelli, Mireille; Müller-Gerbl, Magdalena

    2017-09-01

    Following the principles of "morphology reveals biomechanics," the cartilage-osseous interface and the trabecular network show defined adaptation in response to physiological loading. In the case of a compromised relationship, the ability to support the load diminishes and the onset of osteoarthritis (OA) may arise. To describe and quantify the changes within the subchondral bone plate (SBP) and trabecular architecture, 10 human OA patellae were investigated by CT and micro-CT. The results are presented in comparison to a previously published dataset of 10 non-OA patellae which were evaluated in the same manner. The analyzed OA samples showed no distinctive mineralization pattern in regards to the physiological biomechanics, but a highly irregular disseminated distribution. In addition, no regularity in bone distribution and architecture across the trabecular network was found. We observed a decrease of material as the bone volume and trabecular thickness/number were significantly reduced. In comparison to non-OA samples, greatest differences for all parameters were found within the first mm of trabecular bone. The differences decreased toward the fifth mm in a logarithmic manner. The interpretation of the logarithmic relation leads to the conclusion that the main impact of OA on bony structures is located beneath the SBP and lessens with depth. In addition to the clear difference in material with approximately 12% less bone volume in the first mm in OA patellae, the architectural arrangement is more rod-like and isotropic, accounting for an architectural decrease in stability and support. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1982-1989, 2017. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  10. Scanning electron microscopy of the trabecular meshwork: Understanding the pathogenesis of primary angle closure glaucoma

    Directory of Open Access Journals (Sweden)

    Ramanjit Sihota

    2012-01-01

    Full Text Available Purpose: To study ultrastructural changes of the trabecular meshwork in acute and chronic primary angle closure glaucoma (PACG and primary open angle glaucoma (POAG eyes by scanning electron microscopy. Materials and Methods: Twenty-one trabecular meshwork surgical specimens from consecutive glaucomatous eyes after a trabeculectomy and five postmortem corneoscleral specimens were fixed immediately in Karnovsky solution. The tissues were washed in 0.1 M phosphate buffer saline, post-fixed in 1% osmium tetraoxide, dehydrated in acetone series (30-100%, dried and mounted. Results: Normal trabecular tissue showed well-defined, thin, cylindrical uveal trabecular beams with many large spaces, overlying flatter corneoscleral beams and numerous smaller spaces. In acute PACG eyes, the trabecular meshwork showed grossly swollen, irregular trabecular endothelial cells with intercellular and occasional basal separation with few spaces. Numerous activated macrophages, leucocytes and amorphous debris were present. Chronic PACG eyes had a few, thickened posterior uveal trabecular beams visible. A homogenous deposit covered the anterior uveal trabeculae and spaces. Converging, fan-shaped trabecular beam configuration corresponded to gonioscopic areas of peripheral anterior synechiae. In POAG eyes, anterior uveal trabecular beams were thin and strap-like, while those posteriorly were wide, with a homogenous deposit covering and bridging intertrabecular spaces, especially posteriorly. Underlying corneoscleral trabecular layers and spaces were visualized in some areas. Conclusions: In acute PACG a marked edema of the endothelium probably contributes for the acute and marked intraocular pressure (IOP elevation. Chronically raised IOP in chronic PACG and POAG probably results, at least in part, from decreased aqueous outflow secondary to widening and fusion of adjacent trabecular beams, together with the homogenous deposit enmeshing trabecular beams and spaces.

  11. Effect of micro-computed tomography voxel size and segmentation method on trabecular bone microstructure measures in mice

    Directory of Open Access Journals (Sweden)

    Blaine A. Christiansen

    2016-12-01

    Full Text Available Micro-computed tomography (μCT is currently the gold standard for determining trabecular bone microstructure in small animal models. Numerous parameters associated with scanning and evaluation of μCT scans can strongly affect morphologic results obtained from bone samples. However, the effect of these parameters on specific trabecular bone outcomes is not well understood. This study investigated the effect of μCT scanning with nominal voxel sizes between 6–30 μm on trabecular bone outcomes quantified in mouse vertebral body trabecular bone. Additionally, two methods for determining a global segmentation threshold were compared: based on qualitative assessment of 2D images, or based on quantitative assessment of image histograms. It was found that nominal voxel size had a strong effect on several commonly reported trabecular bone parameters, in particular connectivity density, trabecular thickness, and bone tissue mineral density. Additionally, the two segmentation methods provided similar trabecular bone outcomes for scans with small nominal voxel sizes, but considerably different outcomes for scans with larger voxel sizes. The Qualitatively Selected segmentation method more consistently estimated trabecular bone volume fraction (BV/TV and trabecular thickness across different voxel sizes, but the Histogram segmentation method more consistently estimated trabecular number, trabecular separation, and structure model index. Altogether, these results suggest that high-resolution scans be used whenever possible to provide the most accurate estimation of trabecular bone microstructure, and that the limitations of accurately determining trabecular bone outcomes should be considered when selecting scan parameters and making conclusions about inter-group variance or between-group differences in studies of trabecular bone microstructure in small animals. Keywords: Trabecular bone, Microstructure, Micro-computed tomography, Voxel size, Resolution

  12. Two and three-dimensional morphometric analysis of trabecular bone using X-ray microtomography (μCT)

    International Nuclear Information System (INIS)

    Silva, Alessandro Marcio Hakme da; Silva, Orivaldo Lopes da; Silva Junior, Nelson Ferreira da; Alves, Jose Marcos

    2014-01-01

    Introduction: trabecular bones have a porous microstructure and can be modeled as linear elastic solids, heterogeneous and anisotropic. In the literature, few investigations have compared the two- dimensional (2D) and three-dimensional (3D) morphometric analyses of cancellous bone. Methods: In this investigation eighteen cylindrical samples of cancellous bone (10 mm of diameter and 20 mm of height) were obtained from six bovine head femurs, with similar values for the weight and age, of the same race and gender. The samples were harvested and freeze at - 20 °C before carrying out the micro CT analysis. The CT-Analyzer software was used to measure in three directions (superior-inferior, lateral-medial and anterior-posterior) parameters such as trabecular thickness, trabecular separation, trabecular number and the eigenvalues of the fabric tensor (M). Results: the Comparison of 2D and 3D analyses for the parameters: 2D (plate model) trabecular thickness, trabecular separation and trabecular number were statistically different (p = 0) showing that measurements are not similar to the 3D ones. However, 2D (rod model) trabecular thickness and 3D trabecular thickness measurements presented no significant difference (p = 0.26). The eigenvalues show that the bovine trabecular microstructure has a tendency to transversally isotropic symmetry. Discussion: The method proved to be quite interesting for the characterization of the bone structure through 3D measurements of trabecular bone morphometric parameters in the three possible directions of loading. The results show that x-ray microtomography (μCT) is a technique of great potential for characterization and generating bone quality parameters for the diagnosis of bone metabolism diseases. (author)

  13. Two and three-dimensional morphometric analysis of trabecular bone using X-ray microtomography (μCT)

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Alessandro Marcio Hakme da; Silva, Orivaldo Lopes da; Silva Junior, Nelson Ferreira da, E-mail: alhakme@sc.usp.br [Universidade de Sao Paulo (EESC/FMRP/IQSC/USP), Sao Carlos, SP (Brazil); Alves, Jose Marcos [Universidade de Sao Paulo (USP), Sao Carlos, SP (Brazil). Escola de Engenharia. Departamento de Engenharia Eletrica e Computacao

    2014-07-01

    Introduction: trabecular bones have a porous microstructure and can be modeled as linear elastic solids, heterogeneous and anisotropic. In the literature, few investigations have compared the two- dimensional (2D) and three-dimensional (3D) morphometric analyses of cancellous bone. Methods: In this investigation eighteen cylindrical samples of cancellous bone (10 mm of diameter and 20 mm of height) were obtained from six bovine head femurs, with similar values for the weight and age, of the same race and gender. The samples were harvested and freeze at - 20 °C before carrying out the micro CT analysis. The CT-Analyzer software was used to measure in three directions (superior-inferior, lateral-medial and anterior-posterior) parameters such as trabecular thickness, trabecular separation, trabecular number and the eigenvalues of the fabric tensor (M). Results: the Comparison of 2D and 3D analyses for the parameters: 2D (plate model) trabecular thickness, trabecular separation and trabecular number were statistically different (p = 0) showing that measurements are not similar to the 3D ones. However, 2D (rod model) trabecular thickness and 3D trabecular thickness measurements presented no significant difference (p = 0.26). The eigenvalues show that the bovine trabecular microstructure has a tendency to transversally isotropic symmetry. Discussion: The method proved to be quite interesting for the characterization of the bone structure through 3D measurements of trabecular bone morphometric parameters in the three possible directions of loading. The results show that x-ray microtomography (μCT) is a technique of great potential for characterization and generating bone quality parameters for the diagnosis of bone metabolism diseases. (author)

  14. Validation of calcaneus trabecular microstructure measurements by HR-pQCT.

    Science.gov (United States)

    Metcalf, Louis M; Dall'Ara, Enrico; Paggiosi, Margaret A; Rochester, John R; Vilayphiou, Nicolas; Kemp, Graham J; McCloskey, Eugene V

    2018-01-01

    Assessment of calcaneus microstructure using high-resolution peripheral quantitative computed tomography (HR-pQCT) might be used to improve fracture risk predictions or to assess responses to pharmacological and physical interventions. To develop a standard clinical protocol for the calcaneus, we validated calcaneus trabecular microstructure measured by HR-pQCT against 'gold-standard' micro-CT measurements. Ten human cadaveric feet were scanned in situ using HR-pQCT (isotropic 82μm voxel size) at 100, 150 and 200ms integration times, and at 100ms integration time following removal of the calcaneus from the foot (ex vivo). Dissected portions of these bones were scanned using micro-computed tomography (micro-CT) at an isotropic 17.4μm voxel size. HR-pQCT images were rigidly registered to those obtained with micro-CT and divided into multiple 5mm sided cubes to evaluate and compare morphometric parameters between the modalities. Standard HR-pQCT measurements (derived bone volume fraction (BV/TV d ); trabecular number, Tb.N; derived trabecular thickness, Tb.Th d ; derived trabecular spacing, Tb.Sp d ) and corresponding micro-CT voxel-based measurements (BV/TV, Tb.N, Tb.Th, Tb.Sp) were compared. A total of 108 regions of interest were analysed across the 10 specimens. At all integration times HR-pQCT BV/TV d was strongly correlated with micro-CT BV/TV (r 2 =0.95-0.98, RMSE=1%), but BV/TV d was systematically lower than that measured by micro-CT (mean bias=5%). In contrast, HR-pQCT systematically overestimated Tb.N at all integration times; of the in situ scans, 200ms yielded the lowest mean bias and the strongest correlation with micro-CT (r 2 =0.61, RMSE=0.15mm -1 ). Regional analysis revealed greater accuracy for Tb.N in the superior regions of the calcaneus at all integration times in situ (mean bias=0.44-0.85mm -1 ; r 2 =0.70-0.88, pmicrostructure, particularly in the superior region of the calcaneus, can be assessed by HR-pQCT. The highest integration time

  15. Hyperfunctioning solid/trabecular follicular carcinoma of the thyroid gland.

    Science.gov (United States)

    Giovanella, Luca; Fasolini, Fabrizio; Suriano, Sergio; Mazzucchelli, Luca

    2010-01-01

    A 68-year-old woman with solid/trabecular follicular thyroid carcinoma inside of an autonomously functioning thyroid nodule is described in this paper. The patient was referred to our clinic for swelling of the neck and an increased pulse rate. Ultrasonography showed a slightly hypoechoic nodule in the right lobe of the thyroid. Despite suppressed TSH levels, the (99m)Tc-pertechnetate scan showed a hot area corresponding to the nodule with a suppressed uptake in the remaining thyroid tissue. Histopathological examination of the nodule revealed a solid/trabecular follicular thyroid carcinoma. To the best of our knowledge, this is the first case of hyperfunctioning follicular solid/trabecular carcinoma reported in the literature. Even if a hyperfunctioning thyroid carcinoma is an extremely rare malignancy, careful management is recommended so that a malignancy will not be overlooked in the hot thyroid nodules.

  16. Suitability of texture features to assess changes in trabecular bone architecture

    DEFF Research Database (Denmark)

    Veenland, JF; Grashuis, JL; Weinans, H

    2002-01-01

    The purpose of this study was to determine the ability of texture features to assess changes in trabecular bone architecture as projected in radiographs. Micro-CT datasets of trabecular bone were processed to simulate different changes in architecture. Radiographs were simulated by projecting the...

  17. Changes of enzyme activities in lens after glaucoma trabecular resection

    Directory of Open Access Journals (Sweden)

    Jian-Ping Wang

    2013-08-01

    Full Text Available AIM: To observe the change of lens antioxidant enzyme activity after glaucoma trabecular resection. METHODS: Thirty-two eyes of sixteen New-Zealand rabbits(2.2-2.4kgwere divided into two groups. The left eyes of rabbits underwent standard glaucoma trabecular resection were treatment group, and the normal right eyes served as controls. Transparency of lenses was monitored by a slit-lamp biomicroscopy before and after glaucoma trabecular resection. The morphology of lens cells was observed under the light microscope.The activities of Na+-K+-ATPase,catalase(CAT, glutathion peroxidase(GSH-px, glutathione reductase(GR, superoxide dismutase(SODand content of malondialdehyde(MDAin lenses were detected six months after trabecular resection. RESULTS: Lenses were clear in both treatment group and normal control group during the six months after operation. The morphology and structure of lens cells were normal under the light microscope in both operation group and normal group. The activity of lens cells antioxidant enzyme activity were significantly decreased in operation group compared with control group, Na+-K+-ATPase declined by 20.97%, CAT declined by 16.36%, SOD declined by 4.46%, GR declined by 4.85%, GSH-px declined by 10.02%, and MDA increased by 16.31%. CONCLUSION: Glaucoma trabecular resection can induce the change of Na+-K+-ATPase, CAT, GSH-px, GR, SOD and MDA in lens of rabbit. Glaucoma filtration surgery for the occurrence of cataract development mechanism has important guiding significance.

  18. Attenuating trabecular morphology associated with low magnesium diet evaluated using micro computed tomography.

    Directory of Open Access Journals (Sweden)

    Shu-Ju Tu

    Full Text Available The literature shows that bone mineral density (BMD and the geometric architecture of trabecular bone in the femur may be affected by inadequate dietary intake of Mg. In this study, we used microcomputed tomography (micro-CT to characterize and quantify the impact of a low-Mg diet on femoral trabecular bones in mice.Four-week-old C57BL/6J male mice were randomly assigned to 2 groups and supplied either a normal or low-Mg diet for 8weeks. Samples of plasma and urine were collected for biochemical analysis, and femur tissues were removed for micro-CT imaging. In addition to considering standard parameters, we regarded trabecular bone as a cylindrical rod and used computational algorithms for a technical assessment of the morphological characteristics of the bones. BMD (mg-HA/cm3 was obtained using a standard phantom.We observed a decline in the total tissue volume, bone volume, percent bone volume, fractal dimension, number of trabecular segments, number of connecting nodes, bone mineral content (mg-HA, and BMD, as well as an increase in the structural model index and surface-area-to-volume ratio in low-Mg mice. Subsequently, we examined the distributions of the trabecular segment length and radius, and a series of specific local maximums were identified. The biochemical analysis revealed a 43% (96% decrease in Mg and a 40% (71% decrease in Ca in plasma (urine excretion.This technical assessment performed using micro-CT revealed a lower population of femoral trabecular bones and a decrease in BMD at the distal metaphysis in the low-Mg mice. Examining the distributions of the length and radius of trabecular segments showed that the average length and radius of the trabecular segments in low-Mg mice are similar to those in normal mice.

  19. Hyperfunctioning Solid/Trabecular Follicular Carcinoma of the Thyroid Gland

    Directory of Open Access Journals (Sweden)

    Luca Giovanella

    2010-01-01

    Full Text Available A 68-year-old woman with solid/trabecular follicular thyroid carcinoma inside of an autonomously functioning thyroid nodule is described in this paper. The patient was referred to our clinic for swelling of the neck and an increased pulse rate. Ultrasonography showed a slightly hypoechoic nodule in the right lobe of the thyroid. Despite suppressed TSH levels, the 99mTc-pertechnetate scan showed a hot area corresponding to the nodule with a suppressed uptake in the remaining thyroid tissue. Histopathological examination of the nodule revealed a solid/trabecular follicular thyroid carcinoma. To the best of our knowledge, this is the first case of hyperfunctioning follicular solid/trabecular carcinoma reported in the literature. Even if a hyperfunctioning thyroid carcinoma is an extremely rare malignancy, careful management is recommended so that a malignancy will not be overlooked in the hot thyroid nodules.

  20. Mechanical and morphological properties of trabecular bone samples obtained from third metacarpal bones of cadavers of horses with a bone fragility syndrome and horses unaffected by that syndrome.

    Science.gov (United States)

    Symons, Jennifer E; Entwistle, Rachel C; Arens, Amanda M; Garcia, Tanya C; Christiansen, Blaine A; Fyhrie, David P; Stover, Susan M

    2012-11-01

    To determine morphological and mechanical properties of trabecular bone of horses with a bone fragility syndrome (BFS; including silicate-associated osteoporosis). Cylindrical trabecular bone samples from the distal aspects of cadaveric third metacarpal bones of 39 horses (19 horses with a BFS [BFS bone samples] and 20 horses without a BFS [control bone samples]). Bone samples were imaged via micro-CT for determination of bone volume fraction; apparent and mean mineralized bone densities; and trabecular number, thickness, and separation. Bone samples were compressed to failure for determination of apparent elastic modulus and stresses, strains, and strain energy densities for yield, ultimate, and failure loads. Effects of BFS and age of horses on variables were determined. BFS bone samples had 25% lower bone volume fraction, 28% lower apparent density, 18% lower trabecular number and thickness, and 16% greater trabecular separation versus control bone samples. The BFS bone samples had 22% lower apparent modulus and 32% to 33% lower stresses, 10% to 18% lower strains, and 41 % to 52% lower strain energy densities at yield, ultimate, and failure loads, compared with control bone samples. Differences between groups of bone samples were not detected for mean mineral density and trabecular anisotropy. Results suggested that horses with a BFS had osteopenia and compromised trabecular bone function, consistent with bone deformation and pathological fractures that develop in affected horses. Effects of this BFS may be systemic, and bones other than those that are clinically affected had changes in morphological and mechanical properties.

  1. Agreement between radiographic and photographic trabecular patterns

    Energy Technology Data Exchange (ETDEWEB)

    Korstjens, C.M.; Geraets, W.G.M.; Stelt, P.F. van der [Dept. of Oral Radiology, Academic Centre for Dentistry, Amsterdam (Netherlands); Spruijt, R.J. [Div. of Psychosocial Research and Epidemiology, Netherlands Cancer Inst., Amsterdam (Netherlands); Mosekilde, L. [Dept. of Cell Biology, Univ. of Aarhus (Denmark)

    1998-11-01

    Purpose: It has been hypothesized that photographs can facilitate the interpretation of the radiographic characteristics of trabecular bone. The reliability of these photographic and radiographic approaches has been determined, as have various agreements between the two approaches and their correlations with biomechanical characteristics. Material and Methods: Fourteen vertebral bodies were obtained at autopsy from 6 women and 8 men aged 22-76 years. Photographs (n=28) and radiographs (n=28) were taken of midsagittal slices from the third lumbar vertebra. The radiographs and photographs were digitized and the geometric properties of the trabecular architecture were then determined with a digital images analysis technique. Information on the compressive strength and ash density of the vertebral body was also available. Results: The geometric properties of both radiographs and photographs could be measured with a high degree of reliability (Cronbach`s {alpha}>0.85). Agreement between the radiographic and photographic approaches was mediocre as only the radiographic measurements showed insignificant correlations (p<0.05) with the biomechanical characteristics. We suggest that optical phenomena may result in the significant correlations between the photographs and the biomechanical characteristics. Conclusion: For digital image processing, radiography offers a superior description of the architecture of trabecular bone to that offered by photography. (orig.)

  2. Agreement between radiographic and photographic trabecular patterns

    International Nuclear Information System (INIS)

    Korstjens, C.M.; Geraets, W.G.M.; Stelt, P.F. van der; Spruijt, R.J.; Mosekilde, L.

    1998-01-01

    Purpose: It has been hypothesized that photographs can facilitate the interpretation of the radiographic characteristics of trabecular bone. The reliability of these photographic and radiographic approaches has been determined, as have various agreements between the two approaches and their correlations with biomechanical characteristics. Material and Methods: Fourteen vertebral bodies were obtained at autopsy from 6 women and 8 men aged 22-76 years. Photographs (n=28) and radiographs (n=28) were taken of midsagittal slices from the third lumbar vertebra. The radiographs and photographs were digitized and the geometric properties of the trabecular architecture were then determined with a digital images analysis technique. Information on the compressive strength and ash density of the vertebral body was also available. Results: The geometric properties of both radiographs and photographs could be measured with a high degree of reliability (Cronbach's α>0.85). Agreement between the radiographic and photographic approaches was mediocre as only the radiographic measurements showed insignificant correlations (p<0.05) with the biomechanical characteristics. We suggest that optical phenomena may result in the significant correlations between the photographs and the biomechanical characteristics. Conclusion: For digital image processing, radiography offers a superior description of the architecture of trabecular bone to that offered by photography. (orig.)

  3. Evaluation of trabecular bone patterns on dental radiographic images: influence of cortical bone

    Science.gov (United States)

    Amouriq, Yves; Evenou, Pierre; Arlicot, Aurore; Normand, Nicolas; Layrolle, Pierre; Weiss, Pierre; Guédon, Jean-Pierre

    2010-03-01

    For some authors trabecular bone is highly visible in intraoral radiographs. For other authors, the observed intrabony trabecular pattern is a representation of only the endosteal surface of cortical bone, not of intermedullary striae. The purpose of this preliminary study was to investigate the true anatomical structures that are visible in routine dental radiographs and classically denoted trabecular bone. This is a major point for bone texture analysis on radiographs. Computed radiography (CR) images of dog mandible section in molar region were compared with simulations calculated from high-resolution micro-CT volumes. Calculated simulations were obtained using the Mojette Transform. By digitally editing the CT volume, the simulations were separated into trabecular and cortical components into a region of interest. Different images were compared and correlated, some bone micro-architecture parameters calculated. A high correlation was found between computed radiographs and calculated simulations from micro-CT. The Mojette transform was successful to obtain high quality images. Cortical bone did not contribute to change in a major way simulated images. These first results imply that intrabony trabecular pattern observed on radiographs can not only be a representation of the cortical bone endosteal surface and that trabecular bone is highly visible in intraoral radiographs.

  4. Prediction of trabecular bone qualitative properties using scanning quantitative ultrasound

    Science.gov (United States)

    Qin, Yi-Xian; Lin, Wei; Mittra, Erik; Xia, Yi; Cheng, Jiqi; Judex, Stefan; Rubin, Clint; Müller, Ralph

    2013-11-01

    Microgravity induced bone loss represents a critical health problem in astronauts, particularly occurred in weight-supporting skeleton, which leads to osteopenia and increase of fracture risk. Lack of suitable evaluation modality makes it difficult for monitoring skeletal status in long term space mission and increases potential risk of complication. Such disuse osteopenia and osteoporosis compromise trabecular bone density, and architectural and mechanical properties. While X-ray based imaging would not be practical in space, quantitative ultrasound may provide advantages to characterize bone density and strength through wave propagation in complex trabecular structure. This study used a scanning confocal acoustic diagnostic and navigation system (SCAN) to evaluate trabecular bone quality in 60 cubic trabecular samples harvested from adult sheep. Ultrasound image based SCAN measurements in structural and strength properties were validated by μCT and compressive mechanical testing. This result indicated a moderately strong negative correlations observed between broadband ultrasonic attenuation (BUA) and μCT-determined bone volume fraction (BV/TV, R2=0.53). Strong correlations were observed between ultrasound velocity (UV) and bone's mechanical strength and structural parameters, i.e., bulk Young's modulus (R2=0.67) and BV/TV (R2=0.85). The predictions for bone density and mechanical strength were significantly improved by using a linear combination of both BUA and UV, yielding R2=0.92 for BV/TV and R2=0.71 for bulk Young's modulus. These results imply that quantitative ultrasound can characterize trabecular structural and mechanical properties through measurements of particular ultrasound parameters, and potentially provide an excellent estimation for bone's structural integrity.

  5. Trabecular bone structure parameters from 3D image processing of clinical multi-slice and cone-beam computed tomography data

    Energy Technology Data Exchange (ETDEWEB)

    Klintstroem, Eva; Smedby, Oerjan [Linkoeping University, Center for Medical Image Science and Visualization (CMIV), Linkoeping (Sweden); UHL County Council of Oestergoetland, Department of Radiology, Linkoeping (Sweden); Linkoeping University, Department of Medical and Health Sciences (IMH)/Radiology, Linkoeping (Sweden); Moreno, Rodrigo [Linkoeping University, Center for Medical Image Science and Visualization (CMIV), Linkoeping (Sweden); Linkoeping University, Department of Medical and Health Sciences (IMH)/Radiology, Linkoeping (Sweden); Brismar, Torkel B. [KUS Huddinge, Department of Clinical Science, Intervention and Technology at Karolinska Institutet and Department of Radiology, Stockholm (Sweden)

    2014-02-15

    Bone strength depends on both mineral content and bone structure. The aim of this in vitro study was to develop a method of quantitatively assessing trabecular bone structure by applying three-dimensional image processing to data acquired with multi-slice and cone-beam computed tomography using micro-computed tomography as a reference. Fifteen bone samples from the radius were examined. After segmentation, quantitative measures of bone volume, trabecular thickness, trabecular separation, trabecular number, trabecular nodes, and trabecular termini were obtained. The clinical machines overestimated bone volume and trabecular thickness and underestimated trabecular nodes and number, but cone-beam CT to a lesser extent. Parameters obtained from cone beam CT were strongly correlated with μCT, with correlation coefficients between 0.93 and 0.98 for all parameters except trabecular termini. The high correlation between cone-beam CT and micro-CT suggest the possibility of quantifying and monitoring changes of trabecular bone microarchitecture in vivo using cone beam CT. (orig.)

  6. Trabecular mineral content of the spine in women with hip fracture: CT measurement

    International Nuclear Information System (INIS)

    Firooznia, H.; Rafii, M.; Golimbu, C.; Schwartz, M.S.; Ort, P.

    1986-01-01

    The trabecular bone mineral content (BMC) of the spine was measured by computed tomography in 185 women aged 47-84 years with vertebral fracture (n = 74), hip fracture (n = 83), and both vertebral and hip fracture (n = 28). Eighty-seven percent of vertebral-fracture patients, 38% of hip-fracture patients, and 82% of vertebral- and hip-fracture patients had spinal BMC values below the fifth percentile for healthy premenopausal women and values 64%, 9%, and 68% below the fifth percentile for age-matched control subjects. No significant loss of spinal trabecular bone was seen in patients with hip fracture. If it is assumed that the rate of trabecular bone loss is the same in the spine and femoral neck, then hip fracture (unlike osteoporotic vertebral fracture) is not associated with disproportionate loss of trabecular bone. Hip fracture occurs secondary to weakening of bone and increased incidence of falls. Bone weakening may be due to disproportionate loss of trabecular or cortical bone, proportionate loss of both, or other as yet undetermined qualitative changes in bone

  7. INAA of cortical and trabecular bone samples from animals

    International Nuclear Information System (INIS)

    Takata, M.K.; Saiki, M.

    2004-01-01

    Instrumental neutron activation analysis (INAA) was applied to determine Ba, Br, Ca, Cl, Fe, K, Mg, Mn, Na, P, Sr and Zn in bovine and porcine rib bones. Precise results were obtained in analyses of freeze-dried cortical and trabecular bones separately, and also of whole bone ashes. Cortical tissues presented higher concentrations of Ba, Ca, Mg, Mn, Na, P, Sr and Zn than those obtained in trabecular ones. Comparisons were also made between the results obtained for bovine and porcine rib bones. (author)

  8. Identification of trabecular excrescences, novel microanatomical structures, present in bone in osteoarthropathies

    Directory of Open Access Journals (Sweden)

    AM Taylor

    2012-04-01

    Full Text Available It is widely held that bone architecture is finely regulated in accordance with homeostatic requirements. Aberrant remodelling (hyperdensification and/or cyst formation in the immediately subchondral region has previously been described in bone underlying cartilage in arthropathies. The present study examined the trabecular architecture of samples of bone, initially in the severe osteoarthropathy of alkaptonuria, but subsequently in osteoarthritis using a combination of light microscopy, 3D scanning electron microscopy and quantitative backscattered electron scanning electron microscopy. We report an extraordinary and previously unrecognised bone phenotype in both disorders, including novel microanatomical structures. The underlying subchondral trabecular bone contained idiosyncratic architecture. Trabecular surfaces had numerous outgrowths that we have termed "trabecular excrescences", of which three distinct types were recognised. The first type arose from incomplete resorption of branching secondary trabeculae arising from the deposition of immature (woven bone in prior marrow space. These were characterised by very deeply scalloped surfaces and rugged edges. The second type had arisen in a similar way but been smoothed over by new bone deposition. The third type, which resembled coarse stucco, probably arises from resting surfaces that had been focally reactivated. These were poorly integrated with the prior trabecular wall. We propose that these distinctive microanatomical structures are indicative of abnormal osteoclast/osteoblast modelling in osteoarthropathies, possibly secondary to altered mechanical loading or other aberrant signalling. Identification of the mechanisms underlying the formation of trabecular excrescences will contribute to a better understanding of the role of aberrant bone remodelling in arthropathies and development of new therapeutic strategies.

  9. Effect of swimming exercise on three-dimensional trabecular bone microarchitecture in ovariectomized rats.

    Science.gov (United States)

    Ju, Yong-In; Sone, Teruki; Ohnaru, Kazuhiro; Tanaka, Kensuke; Fukunaga, Masao

    2015-11-01

    Swimming is generally considered ineffective for increasing bone mass in humans, at least compared with weight-bearing sports. However, swimming exercise has sometimes been shown to have a strong positive effect on bone mass in small animals. This study investigated the effects of swimming on bone mass, strength, and microarchitecture in ovariectomized (OVX) rats. OVX or sham operations were performed on 18-wk-old female Fisher 344 rats. Rats were randomly divided into four groups: sham sedentary (Sham-CON), sham swimming exercised (Sham-SWI), OVX sedentary (OVX-CON), and OVX swimming exercised (OVX-SWI). Rats in exercise groups performed swimming in a water bath for 60 min/day, 5 days/wk, for 12 wk. Bone mineral density (BMD) in right femurs was analyzed using dual-energy X-ray absorptiometry. Three-dimensional trabecular architecture at the distal femoral metaphysis was analyzed using microcomputed tomography (μCT). Geometrical properties of diaphyseal cortical bone were evaluated in the midfemoral region using μCT. The biomechanical properties of femurs were analyzed using three-point bending. Femoral BMD was significantly decreased following ovariectomy. This change was suppressed by swimming. Trabecular bone thickness, number, and connectivity were decreased by ovariectomy, whereas structure model index (i.e., ratio of rod-like to plate-like trabeculae) increased. These changes were also suppressed by swimming exercise. Femurs displayed greater cortical width and maximum load in SWI groups than in CON groups. Together, these results demonstrate that swimming exercise drastically alleviated both OVX-induced decreases in bone mass and mechanical strength and the deterioration of trabecular microarchitecture in rat models of osteoporosis. Copyright © 2015 the American Physiological Society.

  10. Quantitative computed tomography in measurement of vertebral trabecular bone mass

    International Nuclear Information System (INIS)

    Nilsson, M.; Johnell, O.; Jonsson, K.; Redlund-Johnell, I.

    1988-01-01

    Measurement of bone mineral concentration (BMC) can be done by several modalities. Quantitative computed tomography (QCT) can be used for measurements at different sites and with different types of bone (trabecular-cortical). This study presents a modified method reducing the influence of fat. Determination of BMC was made from measurements with single-energy computed tomography (CT) of the mean Hounsfield number in the trabecular part of the L1 vertebra. The method takes into account the age-dependent composition of the trabecular part of the vertebra. As the amount of intravertebral fat increases with age, the effective atomic number for these parts decreases. This results in a non-linear calibration curve for single-energy CT. Comparison of BMC values using the non-linear calibration curve or the traditional linear calibration with those obtained with a pixel-by-pixel based electron density calculation method (theoretically better) showed results clearly in favor of the non-linear method. The material consisted of 327 patients aged 6 to 91 years, of whom 197 were considered normal. The normal data show a sharp decrease in trabecular bone after the age of 50 in women. In men a slower decrease was found. The vertebrae were larger in men than in women. (orig.)

  11. Genomic and post-genomic effects of anti-glaucoma drugs preservatives in trabecular meshwork

    Energy Technology Data Exchange (ETDEWEB)

    Izzotti, Alberto, E-mail: izzotti@unige.it [Mutagenesis Unit, IRCCS AOU San Martino – IST, Genova (Italy); Department of Health Sciences, University of Genoa, Via A. Pastore 1, 16132 Genoa (Italy); La Maestra, Sebastiano; Micale, Rosanna Tindara; Longobardi, Maria Grazia [Department of Health Sciences, University of Genoa, Via A. Pastore 1, 16132 Genoa (Italy); Saccà, Sergio Claudio [Ophthalmology Unit, IRCCS AOU San Martino-IST, Genova (Italy)

    2015-02-15

    Highlights: • Glaucoma drug preservatives induce DNA damage in trabecular meshwork cells. • Cellular alteration is related with the occurrence of activation of apoptosis through the intrinsic pathway. • Drug preservatives unable to induce cell damage are ineffective in killing bacteria. • Anti glaucoma drugs should be formulated as single-dose usage devoid of genotoxic preservatives. - Abstract: Oxidative stress plays an important role in glaucoma. Some preservatives of anti-glaucoma drugs, commonly used in glaucoma therapy, can prevent or induce oxidative stress in the trabecular meshwork. The aim of this study is to evaluate cellular and molecular damage induced in trabecular meshwork by preservatives contained in anti-glaucoma drugs. Cell viability (MTT test), DNA fragmentation (Comet test), oxidative DNA damage (8-oxo-dG), and gene expression (cDNA microarray) have been evaluated in trabecular meshwork specimens and in human trabecular meshwork cells treated with benzalkonium chloride, polyQuad, purite, and sofzia-like mixture. Moreover, antimicrobial effectiveness and safety of preservative contents in drugs was tested. In ex vivo experiments, benzalkonium chloride and polyQuad induced high level of DNA damage in trabecular meshwork specimens, while the effect of purite and sofzia were more attenuated. The level of DNA fragmentation induced by benzalkonium chloride was 2.4-fold higher in subjects older than 50 years than in younger subjects. Benzalkonium chloride, and polyQuad significantly increased oxidative DNA damage as compared to sham-treated specimens. Gene expression was altered by benzalkonium chloride, polyQuad, and purite but not by sofzia. In in vitro experiments, benzalkonium chloride and polyQuad dramatically decreased trabecular meshwork cell viability, increased DNA fragmentation, and altered gene expression. A lesser effect was also exerted by purite and sofzia. Genes targeted by these alterations included Fas and effector caspase-3

  12. Age variations in the properties of human tibial trabecular bone

    DEFF Research Database (Denmark)

    Ding, Ming; Dalstra, M; Danielsen, CC

    1997-01-01

    We tested in compression specimens of human proximal tibial trabecular bone from 31 normal donors aged from 16 to 83 years and determined the mechanical properties, density and mineral and collagen content. Young's modulus and ultimate stress were highest between 40 and 50 years, whereas ultimate...... strain and failure energy showed maxima at younger ages. These age-related variations (except for failure energy) were non-linear. Tissue density and mineral concentration were constant throughout life, whereas apparent density (the amount of bone) varied with ultimate stress. Collagen density (the...... amount of collagen) varied with failure energy. Collagen concentration was maximal at younger ages but varied little with age. Our results suggest that the decrease in mechanical properties of trabecular bone such as Young's modulus and ultimate stress is mainly a consequence of the loss of trabecular...

  13. A theoretical framework for strain-related trabecular bone maintenance and adaptation.

    Science.gov (United States)

    Ruimerman, R; Hilbers, P; van Rietbergen, B; Huiskes, R

    2005-04-01

    It is assumed that density and morphology of trabecular bone is partially controlled by mechanical forces. How these effects are expressed in the local metabolic functions of osteoclast resorption and osteoblast formation is not known. In order to investigate possible mechano-biological pathways for these mechanisms we have proposed a mathematical theory (Nature 405 (2000) 704). This theory is based on hypothetical osteocyte stimulation of osteoblast bone formation, as an effect of elevated strain in the bone matrix, and a role for microcracks and disuse in promoting osteoclast resorption. Applied in a 2-D Finite Element Analysis model, the theory explained the formation of trabecular patterns. In this article we present a 3-D FEA model based on the same theory and investigated its potential morphological predictability of metabolic reactions to mechanical loads. The computations simulated the development of trabecular morphological details during growth, relative to measurements in growing pigs, reasonably realistic. They confirmed that the proposed mechanisms also inherently lead to optimal stress transfer. Alternative loading directions produced new trabecular orientations. Reduction of load reduced trabecular thickness, connectivity and mass in the simulation, as is seen in disuse osteoporosis. Simulating the effects of estrogen deficiency through increased osteoclast resorption frequencies produced osteoporotic morphologies as well, as seen in post-menopausal osteoporosis. We conclude that the theory provides a suitable computational framework to investigate hypothetical relationships between bone loading and metabolic expressions.

  14. Experimentally-based multiscale model of the elastic moduli of bovine trabecular bone and its constituents

    Energy Technology Data Exchange (ETDEWEB)

    Hamed, Elham [University of Illinois at Urbana-Champaign, Department of Mechanical Science and Engineering, 1206 West Green Street, Urbana, IL 61801 (United States); Novitskaya, Ekaterina, E-mail: eevdokim@ucsd.edu [University of California, San Diego, Department of Mechanical and Aerospace Engineering, Materials Science and Engineering Program, 9500 Gilman Dr., La Jolla, CA 92093 (United States); Li, Jun; Jasiuk, Iwona [University of Illinois at Urbana-Champaign, Department of Mechanical Science and Engineering, 1206 West Green Street, Urbana, IL 61801 (United States); McKittrick, Joanna [University of California, San Diego, Department of Mechanical and Aerospace Engineering, Materials Science and Engineering Program, 9500 Gilman Dr., La Jolla, CA 92093 (United States)

    2015-09-01

    The elastic moduli of trabecular bone were modeled using an analytical multiscale approach. Trabecular bone was represented as a porous nanocomposite material with a hierarchical structure spanning from the collagen–mineral level to the trabecular architecture level. In parallel, compression testing was done on bovine femoral trabecular bone samples in two anatomical directions, parallel to the femoral neck axis and perpendicular to it, and the measured elastic moduli were compared with the corresponding theoretical results. To gain insights on the interaction of collagen and minerals at the nanoscale, bone samples were deproteinized or demineralized. After such processing, the treated samples remained as self-standing structures and were tested in compression. Micro-computed tomography was used to characterize the hierarchical structure of these three bone types and to quantify the amount of bone porosity. The obtained experimental data served as inputs to the multiscale model and guided us to represent bone as an interpenetrating composite material. Good agreement was found between the theory and experiments for the elastic moduli of the untreated, deproteinized, and demineralized trabecular bone. - Highlights: • A multiscale model was used to predict the elastic moduli of trabecular bone. • Samples included demineralized, deproteinized and untreated bone. • The model portrays bone as a porous, interpenetrating two phase composite. • The experimental elastic moduli for trabecular bone fell between theoretical bounds.

  15. Experimentally-based multiscale model of the elastic moduli of bovine trabecular bone and its constituents

    International Nuclear Information System (INIS)

    Hamed, Elham; Novitskaya, Ekaterina; Li, Jun; Jasiuk, Iwona; McKittrick, Joanna

    2015-01-01

    The elastic moduli of trabecular bone were modeled using an analytical multiscale approach. Trabecular bone was represented as a porous nanocomposite material with a hierarchical structure spanning from the collagen–mineral level to the trabecular architecture level. In parallel, compression testing was done on bovine femoral trabecular bone samples in two anatomical directions, parallel to the femoral neck axis and perpendicular to it, and the measured elastic moduli were compared with the corresponding theoretical results. To gain insights on the interaction of collagen and minerals at the nanoscale, bone samples were deproteinized or demineralized. After such processing, the treated samples remained as self-standing structures and were tested in compression. Micro-computed tomography was used to characterize the hierarchical structure of these three bone types and to quantify the amount of bone porosity. The obtained experimental data served as inputs to the multiscale model and guided us to represent bone as an interpenetrating composite material. Good agreement was found between the theory and experiments for the elastic moduli of the untreated, deproteinized, and demineralized trabecular bone. - Highlights: • A multiscale model was used to predict the elastic moduli of trabecular bone. • Samples included demineralized, deproteinized and untreated bone. • The model portrays bone as a porous, interpenetrating two phase composite. • The experimental elastic moduli for trabecular bone fell between theoretical bounds

  16. Heritability of prevalent vertebral fracture and volumetric bone mineral density and geometry at the lumbar spine in three generations of the Framingham study.

    Science.gov (United States)

    Liu, Ching-Ti; Karasik, David; Zhou, Yanhua; Hsu, Yi-Hsiang; Genant, Harry K; Broe, Kerry E; Lang, Thomas F; Samelson, Elizabeth J; Demissie, Serkalem; Bouxsein, Mary L; Cupples, L Adrienne; Kiel, Douglas P

    2012-04-01

    Genetic factors likely contribute to the risk for vertebral fractures; however, there are few studies on the genetic contributions to vertebral fracture (VFrx), vertebral volumetric bone mineral density (vBMD), and geometry. Also, the heritability (h(2)) for VFrx and its genetic correlation with phenotypes contributing to VFrx risk have not been established. This study aims to estimate the h(2) of vertebral fracture, vBMD, and cross-sectional area (CSA) derived from quantitative computed tomography (QCT) scans and to estimate the extent to which they share common genetic association in adults of European ancestry from three generations of Framingham Heart Study (FHS) families. Members of the FHS families were assessed for VFrx by lateral radiographs or QCT lateral scout views at 13 vertebral levels (T(4) to L(4)) using Genant's semiquantitative (SQ) scale (grades 0 to 3). Vertebral fracture was defined as having at least 25% reduction in height of any vertebra. We also analyzed QCT scans at the L(3) level for integral (In.BMD) and trabecular (Tb.BMD) vBMD and CSA. Heritability estimates were calculated, and bivariate genetic correlation analysis was performed, adjusting for various covariates. For VFrx, we analyzed 4099 individuals (148 VFrx cases) including 2082 women and 2017 men from three generations. Estimates of crude and multivariable-adjusted h(2) were 0.43 to 0.69 (p < 1.1 × 10(-2)). A total of 3333 individuals including 1737 men and 1596 women from two generations had VFrx status and QCT-derived vBMD and CSA information. Estimates of crude and multivariable-adjusted h(2) for vBMD and CSA ranged from 0.27 to 0.51. In a bivariate analysis, there was a moderate genetic correlation between VFrx and multivariable-adjusted In.BMD (-0.22) and Tb.BMD (-0.29). Our study suggests vertebral fracture, vertebral vBMD, and CSA in adults of European ancestry are heritable, underscoring the importance of further work to identify the specific variants underlying

  17. Bone dosimetry using synthetic images to represent trabecular bones of five regions of the human body

    Energy Technology Data Exchange (ETDEWEB)

    Lima Filho, Jose de M. [Instituto Federal de Educacao, Ciencia e Tecnologia de Pernambuco (IFPE), Recife, PE (Brazil); Vieira, Jose W. [Escola Politecnica de Pernambuco (POLI). Universidade de Pernambuco (UPE), Recife, PE (Brazil); Lima, Vanildo J. de M., E-mail: vjr@ufpe.br [Departamento de Anatomia. Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil); Lima, Lindeval F., E-mail: lindeval@dmat.ufrr.br [Departamento de Matematica (DMAT). Universidade Federal de Roraima (UFRR), Boa Vista, RR (Brazil); Lima, Fernando R.A., E-mail: falima@cnen.gov.br [Centro Regional de Ciencias Nucleares (CRCN/NE-CNEN-PE), Recife, PE (Brazil); Vasconcelos, Wagner E. de [Departamento de Energia Nuclear (DEN). Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil)

    2011-07-01

    One of the greatest challenges in numerical dosimetry of ionizing radiation is to estimate the absorbed dose by bone tissue in the human body. The bone tissues of greater radiosensitivity are the red bone marrow (RBM), that consist of the hematopoietic cells, located within the trabecular bones, and the bone surface cells (BSC), called osteogenic cells. The report 70 of the ICRP lists five spongiosa regions with their respective volume percent of trabecular bone: ribs (also contemplating the clavicles and sternum), spine, long bones, pelvis and skull (also contemplating mandible). The Grupo de Pesquisa em Dosimetria Numerica (GDN/CNPq) has been built exposure computational models (ECMs) based on voxel phantoms and EGSnrc Monte Carlo code. To estimate the energy deposited in the RBM and in the BSC of a phantom, the GDN/CNPq has used a method based on micro-CT images of the five trabecular regions mentioned above. These images were provided by other research institutes and were obtained from scan of bone samples of adult. Here is the greatest difficulty in reproducing this method: besides the need for bone images of real people with micrometer resolution, the distribution of bone marrow in the human body, according to ICRP 70, varies with age. This article presents some proposals of the GDN/CNPQ for replacing in the ECMs the micro-CT images by images synthesized by the computer, based on Monte Carlo sampling. (author)

  18. Bone dosimetry using synthetic images to represent trabecular bones of five regions of the human body

    International Nuclear Information System (INIS)

    Lima Filho, Jose de M.; Vieira, Jose W.; Lima, Vanildo J. de M.; Lima, Lindeval F.; Lima, Fernando R.A.; Vasconcelos, Wagner E. de

    2011-01-01

    One of the greatest challenges in numerical dosimetry of ionizing radiation is to estimate the absorbed dose by bone tissue in the human body. The bone tissues of greater radiosensitivity are the red bone marrow (RBM), that consist of the hematopoietic cells, located within the trabecular bones, and the bone surface cells (BSC), called osteogenic cells. The report 70 of the ICRP lists five spongiosa regions with their respective volume percent of trabecular bone: ribs (also contemplating the clavicles and sternum), spine, long bones, pelvis and skull (also contemplating mandible). The Grupo de Pesquisa em Dosimetria Numerica (GDN/CNPq) has been built exposure computational models (ECMs) based on voxel phantoms and EGSnrc Monte Carlo code. To estimate the energy deposited in the RBM and in the BSC of a phantom, the GDN/CNPq has used a method based on micro-CT images of the five trabecular regions mentioned above. These images were provided by other research institutes and were obtained from scan of bone samples of adult. Here is the greatest difficulty in reproducing this method: besides the need for bone images of real people with micrometer resolution, the distribution of bone marrow in the human body, according to ICRP 70, varies with age. This article presents some proposals of the GDN/CNPQ for replacing in the ECMs the micro-CT images by images synthesized by the computer, based on Monte Carlo sampling. (author)

  19. MR-based trabecular bone microstructure is not altered in subjects with indolent systemic mastocytosis.

    Science.gov (United States)

    Baum, Thomas; Karampinos, Dimitrios C; Brockow, Knut; Seifert-Klauss, Vanadin; Jungmann, Pia M; Biedermann, Tilo; Rummeny, Ernst J; Bauer, Jan S; Müller, Dirk

    2015-01-01

    Subjects with indolent systemic mastocytosis (ISM) have an increased risk for osteoporosis. It has been demonstrated that trabecular bone microstructure analysis improves the prediction of bone strength beyond dual-energy X-ray absorptiometry-based bone mineral density. The purpose of this study was to obtain Magnetic Resonance (MR)-based trabecular bone microstructure parameters as advanced imaging biomarkers in subjects with ISM (n=18) and compare them with those of normal controls (n=18). Trabecular bone microstructure parameters were not significantly (P>.05) different between subjects with ISM and controls. These findings revealed important pathophysiological information about ISM-associated osteoporosis and may limit the use of trabecular bone microstructure analysis in this clinical setting. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. Creep of trabecular bone from the human proximal tibia

    Energy Technology Data Exchange (ETDEWEB)

    Novitskaya, Ekaterina, E-mail: eevdokim@ucsd.edu [Mechanical and Aerospace Engineering, UC, San Diego, La Jolla, CA 92093 (United States); Materials Science and Engineering Program, UC, San Diego, La Jolla, CA 92093 (United States); Zin, Carolyn [Materials Science and Engineering, Johns Hopkins University, Baltimore, MD 21218 (United States); Chang, Neil; Cory, Esther; Chen, Peter [Departments of Bioengineering and Orthopaedic Surgery, UC, San Diego, La Jolla, CA 92093 (United States); D’Lima, Darryl [Shiley Center for Orthopaedic Research and Education, Scripps Health, La Jolla, CA 92037 (United States); Sah, Robert L. [Materials Science and Engineering Program, UC, San Diego, La Jolla, CA 92093 (United States); Departments of Bioengineering and Orthopaedic Surgery, UC, San Diego, La Jolla, CA 92093 (United States); McKittrick, Joanna [Mechanical and Aerospace Engineering, UC, San Diego, La Jolla, CA 92093 (United States); Materials Science and Engineering Program, UC, San Diego, La Jolla, CA 92093 (United States)

    2014-07-01

    Creep is the deformation that occurs under a prolonged, sustained load and can lead to permanent damage in bone. Creep in bone is a complex phenomenon and varies with type of loading and local mechanical properties. Human trabecular bone samples from proximal tibia were harvested from a 71-year old female cadaver with osteoporosis. The samples were initially subjected to one cycle load up to 1% strain to determine the creep load. Samples were then loaded in compression under a constant stress for 2 h and immediately unloaded. All tests were conducted with the specimens soaked in phosphate buffered saline with proteinase inhibitors at 37 °C. Steady state creep rate and final creep strain were estimated from mechanical testing and compared with published data. The steady state creep rate correlated well with values obtained from bovine tibial and human vertebral trabecular bone, and was higher for lower density samples. Tissue architecture was analyzed by micro-computed tomography (μCT) both before and after creep testing to assess creep deformation and damage accumulated. Quantitative morphometric analysis indicated that creep induced changes in trabecular separation and the structural model index. A main mode of deformation was bending of trabeculae. - Highlights: • Compressive creep tests of human trabecular bone across the tibia were performed. • The creep rate was found to be inversely proportional to the density of the samples. • μ-computed tomography before and after testing identified regions of deformation. • Bending of the trabeculae was found to be the main deformation mode.

  1. Preliminary study of slow and fast ultrasonic waves using MR images of trabecular bone phantom

    Energy Technology Data Exchange (ETDEWEB)

    Solis-Najera, S. E., E-mail: solisnajera@ciencias.unam.mx, E-mail: angel.perez@ciencias.unam.mx, E-mail: lucia.medina@ciencias.unam.mx; Neria-Pérez, J. A., E-mail: solisnajera@ciencias.unam.mx, E-mail: angel.perez@ciencias.unam.mx, E-mail: lucia.medina@ciencias.unam.mx; Medina, L., E-mail: solisnajera@ciencias.unam.mx, E-mail: angel.perez@ciencias.unam.mx, E-mail: lucia.medina@ciencias.unam.mx [Facultad de Ciencias, Universidad Nacional Autónoma de México, México, DF 04510 (Mexico); Garipov, R., E-mail: ruslan.garipov@mrsolutions.co.uk [MR Solutions Ltd, Surrey (United Kingdom); Rodríguez, A. O., E-mail: arog@xanum.uam.mx [Departamento Ingeniería Eléctrica, Universidad Autónoma Metropolitana Iztapalapa, México, DF 09340 (Mexico)

    2014-11-07

    Cancellous bone is a complex tissue that performs physiological and biomechanical functions in all vertebrates. It is made up of trabeculae that, from a simplified structural viewpoint, can be considered as plates and beams in a hyperstatic structure that change with time leading to osteoporosis. Several methods has been developed to study the trabecular bone microstructure among them is the Biot’s model which predicts the existence of two longitudinal waves in porous media; the slow and the fast waves, that can be related to porosity of the media. This paper is focused on the experimental detection of the two Biot’s waves of a trabecular bone phantom, consisting of a trabecular network of inorganic hydroxyapatite. Experimental measurements of both waves were performed using through transmission ultrasound. Results had shown clearly that the propagation of two waves propagation is transversal to the trabecular alignment. Otherwise the waves are overlapped and a single wave seems to be propagated. To validate these results, magnetic resonance images were acquired to assess the trabecular direction, and to assure that the pulses correspond to the slow and fast waves. This approach offers a methodology for non-invasive studies of trabecular bones.

  2. Scaling relations between trabecular bone volume fraction and microstructure at different skeletal sites.

    Science.gov (United States)

    Räth, Christoph; Baum, Thomas; Monetti, Roberto; Sidorenko, Irina; Wolf, Petra; Eckstein, Felix; Matsuura, Maiko; Lochmüller, Eva-Maria; Zysset, Philippe K; Rummeny, Ernst J; Link, Thomas M; Bauer, Jan S

    2013-12-01

    In this study, we investigated the scaling relations between trabecular bone volume fraction (BV/TV) and parameters of the trabecular microstructure at different skeletal sites. Cylindrical bone samples with a diameter of 8mm were harvested from different skeletal sites of 154 human donors in vitro: 87 from the distal radius, 59/69 from the thoracic/lumbar spine, 51 from the femoral neck, and 83 from the greater trochanter. μCT images were obtained with an isotropic spatial resolution of 26μm. BV/TV and trabecular microstructure parameters (TbN, TbTh, TbSp, scaling indices ( and σ of α and αz), and Minkowski Functionals (Surface, Curvature, Euler)) were computed for each sample. The regression coefficient β was determined for each skeletal site as the slope of a linear fit in the double-logarithmic representations of the correlations of BV/TV versus the respective microstructure parameter. Statistically significant correlation coefficients ranging from r=0.36 to r=0.97 were observed for BV/TV versus microstructure parameters, except for Curvature and Euler. The regression coefficients β were 0.19 to 0.23 (TbN), 0.21 to 0.30 (TbTh), -0.28 to -0.24 (TbSp), 0.58 to 0.71 (Surface) and 0.12 to 0.16 (), 0.07 to 0.11 (), -0.44 to -0.30 (σ(α)), and -0.39 to -0.14 (σ(αz)) at the different skeletal sites. The 95% confidence intervals of β overlapped for almost all microstructure parameters at the different skeletal sites. The scaling relations were independent of vertebral fracture status and similar for subjects aged 60-69, 70-79, and >79years. In conclusion, the bone volume fraction-microstructure scaling relations showed a rather universal character. © 2013.

  3. Effect of Low-Dose MDCT and Iterative Reconstruction on Trabecular Bone Microstructure Assessment.

    Science.gov (United States)

    Kopp, Felix K; Holzapfel, Konstantin; Baum, Thomas; Nasirudin, Radin A; Mei, Kai; Garcia, Eduardo G; Burgkart, Rainer; Rummeny, Ernst J; Kirschke, Jan S; Noël, Peter B

    2016-01-01

    We investigated the effects of low-dose multi detector computed tomography (MDCT) in combination with statistical iterative reconstruction algorithms on trabecular bone microstructure parameters. Twelve donated vertebrae were scanned with the routine radiation exposure used in our department (standard-dose) and a low-dose protocol. Reconstructions were performed with filtered backprojection (FBP) and maximum-likelihood based statistical iterative reconstruction (SIR). Trabecular bone microstructure parameters were assessed and statistically compared for each reconstruction. Moreover, fracture loads of the vertebrae were biomechanically determined and correlated to the assessed microstructure parameters. Trabecular bone microstructure parameters based on low-dose MDCT and SIR significantly correlated with vertebral bone strength. There was no significant difference between microstructure parameters calculated on low-dose SIR and standard-dose FBP images. However, the results revealed a strong dependency on the regularization strength applied during SIR. It was observed that stronger regularization might corrupt the microstructure analysis, because the trabecular structure is a very small detail that might get lost during the regularization process. As a consequence, the introduction of SIR for trabecular bone microstructure analysis requires a specific optimization of the regularization parameters. Moreover, in comparison to other approaches, superior noise-resolution trade-offs can be found with the proposed methods.

  4. Measurement of Trabecular Bone Parameters in Porcine Vertebral Bodies Using Multidetector CT: Evaluation of Reproducibility of 3-Dimensional CT Histomorphometry

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Sung Hwan; Goo, Jin Mo [Dept. of Radiology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul (Korea, Republic of); Moon Kyung Chul [Dept. of Pathology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul (Korea, Republic of); An, Sang Bu [Dept. of radiology, National Cancer Center, Goyang (Korea, Republic of); Kim, Kwang Gi [Dept. of Biomedical Engineering, Division of Basic and Applied Sciences, National Cancer Center, Goyang (Korea, Republic of)

    2011-05-15

    To evaluate the reproducibility of 3-dimensional histomorphometry for the microarchitecture analysis of trabecular bone parameters using multidetector computed tomography (MDCT). Thirty-six specimens from porcine vertebral bodies were imaged five times with a 64- detector row MDCT system using the same scan protocols. Locations of the specimens were nearly identical through the scans. Three-dimensional structural parameters of trabecular bone were derived from the five data sets using image analyzing software. The features measured by the analysis programs were trabecular bone volume, trabecular bone volume/tissue volume, trabecular thickness, trabecular separation, trabecular number, trabecular bone pattern factor, structural model index. The structural trabecular parameters showed excellent reproducibility through repeated scanning. Intraclass correlation coefficients of all seven structural parameters were in the range of 0.998 to 1.000. Coefficients of variation of the six structural parameters, excluding structural model index, were not over 1.6%. The measurement of the trabecular structural parameters using multidetector CT and three-dimensional histomophometry analysis program was validated and showed excellent reproducibility. This method could be used as a noninvasive and easily available test in a clinical setting.

  5. Distributional variations in trabecular architecture of the mandibular bone: an in vivo micro-CT analysis in rats.

    Directory of Open Access Journals (Sweden)

    Zhongshuang Liu

    Full Text Available To evaluate the effect of trabecular thickness and trabecular separation on modulating the trabecular architecture of the mandibular bone in ovariectomized rats.Fourteen 12-week-old adult female Wistar rats were divided into an ovariectomy group (OVX and a sham-ovariectomy group (sham. Five months after the surgery, the mandibles from 14 rats (seven OVX and seven sham were analyzed by micro-CT. Images of inter-radicular alveolar bone of the mandibular first molars underwent three-dimensional reconstruction and were analyzed.Compared to the sham group, trabecular thickness in OVX alveolar bone decreased by 27% (P = 0.012, but trabecular separation in OVX alveolar bone increased by 59% (P = 0.005. A thickness and separation map showed that trabeculae of less than 100 μm increased by 46%, whereas trabeculae of more than 200 μm decreased by more than 40% in the OVX group compared to those in the sham group. Furthermore, the OVX separation of those trabecular of more than 200 μm was 65% higher compared to the sham group. Bone mineral density (P = 0.028 and bone volume fraction (p = 0.001 were also significantly decreased in the OVX group compared to the sham group.Ovariectomy-induced bone loss in mandibular bone may be related to the distributional variations in trabecular thickness and separation which profoundly impact the modulation of the trabecular architecture.

  6. Estimation of trabecular bone parameters in children from multisequence MRI using texture-based regression

    Energy Technology Data Exchange (ETDEWEB)

    Lekadir, Karim, E-mail: karim.lekadir@upf.edu; Hoogendoorn, Corné [Center for Computational Imaging and Simulation Technologies in Biomedicine, Universitat Pompeu Fabra, Barcelona 08018 (Spain); Armitage, Paul [The Academic Unit of Radiology, The University of Sheffield, Sheffield S10 2JF (United Kingdom); Whitby, Elspeth [The Academic Unit of Reproductive and Developmental Medicine, The University of Sheffield, Sheffield S10 2SF (United Kingdom); King, David [The Academic Unit of Child Health, The University of Sheffield, Sheffield S10 2TH (United Kingdom); Dimitri, Paul [The Mellanby Centre for Bone Research, The University of Sheffield, Sheffield S10 2RX (United Kingdom); Frangi, Alejandro F. [Center for Computational Imaging and Simulation Technologies in Biomedicine, The University of Sheffield, Sheffield S1 3JD (United Kingdom)

    2016-06-15

    Purpose: This paper presents a statistical approach for the prediction of trabecular bone parameters from low-resolution multisequence magnetic resonance imaging (MRI) in children, thus addressing the limitations of high-resolution modalities such as HR-pQCT, including the significant exposure of young patients to radiation and the limited applicability of such modalities to peripheral bones in vivo. Methods: A statistical predictive model is constructed from a database of MRI and HR-pQCT datasets, to relate the low-resolution MRI appearance in the cancellous bone to the trabecular parameters extracted from the high-resolution images. The description of the MRI appearance is achieved between subjects by using a collection of feature descriptors, which describe the texture properties inside the cancellous bone, and which are invariant to the geometry and size of the trabecular areas. The predictive model is built by fitting to the training data a nonlinear partial least square regression between the input MRI features and the output trabecular parameters. Results: Detailed validation based on a sample of 96 datasets shows correlations >0.7 between the trabecular parameters predicted from low-resolution multisequence MRI based on the proposed statistical model and the values extracted from high-resolution HRp-QCT. Conclusions: The obtained results indicate the promise of the proposed predictive technique for the estimation of trabecular parameters in children from multisequence MRI, thus reducing the need for high-resolution radiation-based scans for a fragile population that is under development and growth.

  7. Rationale for the evaluation of trabecular bone turnover

    International Nuclear Information System (INIS)

    Kimmel, D.B.; Jee, W.S.S.

    1976-01-01

    A procedure for the morphometric evaluation of trabecular bone is identified. Its scrupulous use allows total identification of bone formation and resorption rates, items necessary for the direct histologic analysis of bone turnover

  8. Quasi-static and ratcheting properties of trabecular bone under uniaxial and cyclic compression.

    Science.gov (United States)

    Gao, Li-Lan; Wei, Chao-Lei; Zhang, Chun-Qiu; Gao, Hong; Yang, Nan; Dong, Li-Min

    2017-08-01

    The quasi-static and ratcheting properties of trabecular bone were investigated by experiments and theoretical predictions. The creep tests with different stress levels were completed and it is found that both the creep strain and creep compliance increase rapidly at first and then increase slowly as the creep time goes by. With increase of compressive stress the creep strain increases and the creep compliance decreases. The uniaxial compressive tests show that the applied stress rate makes remarkable influence on the compressive behaviors of trabecular bone. The Young's modulus of trabecular bone increases with increase of stress rate. The stress-strain hysteresis loops of trabecular bone under cyclic load change from sparse to dense with increase of number of cycles, which agrees with the change trend of ratcheting strain. The ratcheting strain rate rapidly decreases at first, and then exhibits a relatively stable and small value after 50cycles. Both the ratcheting strain and ratcheting strain rate increase with increase of stress amplitude or with decrease of stress rate. The creep model and the nonlinear viscoelastic constitutive model of trabecular bone were proposed and used to predict its creep property and rate-dependent compressive property. The results show that there are good agreements between the experimental data and predictions. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Effects of low-intensity pulsed ultrasound on new trabecular bone during bone-tendon junction healing in a rabbit model: a synchrotron radiation micro-CT study.

    Directory of Open Access Journals (Sweden)

    Hongbin Lu

    Full Text Available This study was designed to evaluate the effects of low-intensity pulsed ultrasound on bone regeneration during the bone-tendon junction healing process and to explore the application of synchrotron radiation micro computed tomography in three dimensional visualization of the bone-tendon junction to evaluate the microarchitecture of new trabecular bone. Twenty four mature New Zealand rabbits underwent partial patellectomy to establish a bone-tendon junction injury model at the patella-patellar tendon complex. Animals were then divided into low-intensity pulsed ultrasound treatment (20 min/day, 7 times/week and placebo control groups, and were euthanized at week 8 and 16 postoperatively (n = 6 for each group and time point. The patella-patellar tendon specimens were harvested for radiographic, histological and synchrotron radiation micro computed tomography detection. The area of the newly formed bone in the ultrasound group was significantly greater than that of control group at postoperative week 8 and 16. The high resolution three dimensional visualization images of the bone-tendon junction were acquired by synchrotron radiation micro computed tomography. Low-intensity pulsed ultrasound treatment promoted dense and irregular woven bone formation at week 8 with greater bone volume fraction, number and thickness of new trabecular bone but with lower separation. At week 16, ultrasound group specimens contained mature lamellar bone with higher bone volume fraction and thicker trabeculae than that of control group; however, there was no significant difference in separation and number of the new trabecular bone. This study confirms that low-intensity pulsed ultrasound treatment is able to promote bone formation and remodeling of new trabecular bone during the bone-tendon junction healing process in a rabbit model, and the synchrotron radiation micro computed tomography could be applied for three dimensional visualization to quantitatively evaluate

  10. Finite element analysis of trabecular bone structures : a comparison of image-based meshing techniques

    NARCIS (Netherlands)

    Ulrich, D.; Rietbergen, van B.; Weinans, H.; Rüegsegger, P.

    1998-01-01

    In this study, we investigate if finite element (FE) analyses of human trabecular bone architecture based on 168 microm images can provide relevant information about the bone mechanical characteristics. Three human trabecular bone samples, one taken from the femoral head, one from the iliac crest,

  11. Creep of trabecular bone from the human proximal tibia.

    Science.gov (United States)

    Novitskaya, Ekaterina; Zin, Carolyn; Chang, Neil; Cory, Esther; Chen, Peter; D'Lima, Darryl; Sah, Robert L; McKittrick, Joanna

    2014-07-01

    Creep is the deformation that occurs under a prolonged, sustained load and can lead to permanent damage in bone. Creep in bone is a complex phenomenon and varies with type of loading and local mechanical properties. Human trabecular bone samples from proximal tibia were harvested from a 71-year old female cadaver with osteoporosis. The samples were initially subjected to one cycle load up to 1% strain to determine the creep load. Samples were then loaded in compression under a constant stress for 2h and immediately unloaded. All tests were conducted with the specimens soaked in phosphate buffered saline with proteinase inhibitors at 37 °C. Steady state creep rate and final creep strain were estimated from mechanical testing and compared with published data. The steady state creep rate correlated well with values obtained from bovine tibial and human vertebral trabecular bone, and was higher for lower density samples. Tissue architecture was analyzed by micro-computed tomography (μCT) both before and after creep testing to assess creep deformation and damage accumulated. Quantitative morphometric analysis indicated that creep induced changes in trabecular separation and the structural model index. A main mode of deformation was bending of trabeculae. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Use of MR-based trabecular bone microstructure analysis at the distal radius for osteoporosis diagnostics: a study in post-menopausal women with breast cancer and treated with aromatase inhibitor.

    Science.gov (United States)

    Baum, Thomas; Karampinos, Dimitrios C; Seifert-Klauss, Vanadin; Pencheva, Tsvetelina D; Jungmann, Pia M; Rummeny, Ernst J; Müller, Dirk; Bauer, Jan S

    2016-01-01

    Treatment with aromatase inhibitor (AI) is recommended for post-menopausal women with hormone-receptor positive breast cancer. However, AI therapy is known to induce bone loss leading to osteoporosis with an increased risk for fragility fractures. The purpose of this study was to investigate whether changes of magnetic resonance (MR)-based trabecular bone microstructure parameters as advanced imaging biomarker can already be detected in subjects with AI intake but still without evidence for osteoporosis according to dual energy X-ray absorptiometry (DXA)-based bone mineral density (BMD) measurements as current clinical gold standard. Twenty-one postmenopausal women (62±6 years of age) with hormone-receptor positive breast cancer, ongoing treatment with aromatase inhibitor for 23±15 months, and no evidence for osteoporosis (current DXA T-score greater than -2.5) were recruited for this study. Eight young, healthy women (24±2 years of age) were included as controls. All subjects underwent 3 Tesla magnetic resonance imaging (MRI) of the distal radius to assess the trabecular bone microstructure. Trabecular bone microstructure parameters were not significantly (p>0.05) different between subjects with AI intake and controls, including apparent bone fraction (0.42±0.03 vs. 0.42±0.05), trabecular number (1.95±0.10 mm(-1) vs 1.89±0.15 mm(-1)), trabecular separation (0.30±0.03 mm vs 0.31±0.06 mm), trabecular thickness (0.21±0.01 mm vs 0.22±0.02 mm), and fractal dimension (1.70±0.02 vs. 1.70±0.03). These findings suggest that the initial deterioration of trabecular bone microstructure as measured by MRI and BMD loss as measured by DXA occur not sequentially but rather simultaneously. Thus, the use of MR-based trabecular bone microstructure assessment is limited as early diagnostic biomarker in this clinical setting.

  13. Bone Parameters in Anorexia Nervosa and Athletic Amenorrhea: Comparison of Two Hypothalamic Amenorrhea States.

    Science.gov (United States)

    Kandemir, Nurgun; Slattery, Meghan; Ackerman, Kathryn E; Tulsiani, Shreya; Bose, Amita; Singhal, Vibha; Baskaran, Charumathi; Ebrahimi, Seda; Goldstein, Mark; Eddy, Kamryn; Klibanski, Anne; Misra, Madhusmita

    2018-04-05

    We have reported low bone mineral density (BMD), impaired bone structure, and increased fracture risk in anorexia nervosa (AN) and normal-weight, oligo-amenorrheic athletes (OA). However, data directly comparing compartment-specific bone parameters in AN, OA and controls are lacking. 426 females 14-21.9 years old were included; 231 AN, 94 OA and 101 normal-weight eumenorrheic controls. Dual energy x-ray absorptiometry was used to assess areal BMD (aBMD) of the whole body less head (WBLH), spine, and hip. High resolution peripheral quantitative CT was used to assess volumetric BMD (vBMD), bone geometry and structure at the non-weight bearing distal radius and weight-bearing distal tibia. AN had lower WBLH and hip aBMD Z-scores than OA and controls (p<0.0001). AN and OA had lower spine aBMD Z-scores than controls (p<0.01). At the radius, total and cortical vBMD, percent cortical area and thickness were lower in AN and OA vs. controls (p≤0.04); trabecular vBMD was lower in AN than controls. At the tibia, AN had lower measures for most parameters vs. OA and controls (p<0.05); OA had lower cortical vBMD than controls (p=0.002). AN and OA had higher fracture rates vs. controls. Stress fracture prevalence was highest in OA (p<0.0001); non-stress fracture prevalence was highest in AN (p<0.05). AN is deleterious to bone at all sites and both bone compartments. A high stress fracture rate in OA, who have comparable WBLH and hip aBMD measures to controls, indicates that BMD in these women may need to be even higher to avoid fractures.

  14. Multi-Elemental Profiling of Tibial and Maxillary Trabecular Bone in Ovariectomised Rats

    Directory of Open Access Journals (Sweden)

    Pingping Han

    2016-06-01

    Full Text Available Atomic minerals are the smallest components of bone and the content of Ca, being the most abundant mineral in bone, correlates strongly with the risk of osteoporosis. Postmenopausal women have a far greater risk of suffering from OP due to low Ca concentrations in their bones and this is associated with low bone mass and higher bone fracture rates. However, bone strength is determined not only by Ca level, but also a number of metallic and non-metallic elements in bone. Thus, in this study, the difference of metallic and non-metallic elements in ovariectomy-induced osteoporosis tibial and maxillary trabecular bone was investigated in comparison with sham operated normal bone by laser ablation inductively-coupled plasma mass spectrometry using a rat model. The results demonstrated that the average concentrations of 25Mg, 28Si, 39K, 47Ti, 56Fe, 59Co, 77Se, 88Sr, 137Ba, and 208Pb were generally higher in tibia than those in maxilla. Compared with the sham group, Ovariectomy induced more significant changes of these elements in tibia than maxilla, indicating tibial trabecular bones are more sensitive to changes of circulating estrogen. In addition, the concentrations of 28Si, 77Se, 208Pb, and Ca/P ratios were higher in tibia and maxilla in ovariectomised rats than those in normal bone at all time-points. The present study indicates that ovariectomy could significantly impact the element distribution and concentrations between tibia and maxilla.

  15. Spine Trabecular Bone Score as an Indicator of Bone Microarchitecture at the Peripheral Skeleton in Kidney Transplant Recipients.

    Science.gov (United States)

    Luckman, Matthew; Hans, Didier; Cortez, Natalia; Nishiyama, Kyle K; Agarawal, Sanchita; Zhang, Chengchen; Nikkel, Lucas; Iyer, Sapna; Fusaro, Maria; Guo, Edward X; McMahon, Donald J; Shane, Elizabeth; Nickolas, Thomas L

    2017-04-03

    Studies using high-resolution peripheral quantitative computed tomography showed progressive abnormalities in cortical and trabecular microarchitecture and biomechanical competence over the first year after kidney transplantation. However, high-resolution peripheral computed tomography is a research tool lacking wide availability. In contrast, the trabecular bone score is a novel and widely available tool that uses gray-scale variograms of the spine image from dual-energy x-ray absorptiometry to assess trabecular quality. There are no studies assessing whether trabecular bone score characterizes bone quality in kidney transplant recipients. Between 2009 and 2010, we conducted a study to assess changes in peripheral skeletal microarchitecture, measured by high-resolution peripheral computed tomography, during the first year after transplantation in 47 patients managed with early corticosteroid-withdrawal immunosuppression. All adult first-time transplant candidates were eligible. Patients underwent imaging with high-resolution peripheral computed tomography and dual-energy x-ray absorptiometry pretransplantation and 3, 6, and 12 months post-transplantation. We now test if, during the first year after transplantation, trabecular bone score assesses the evolution of bone microarchitecture and biomechanical competence as determined by high-resolution peripheral computed tomography. At baseline and follow-up, among the 72% and 78%, respectively, of patients having normal bone mineral density by dual-energy x-ray absorptiometry, 53% and 50%, respectively, were classified by trabecular bone score as having high fracture risk. At baseline, trabecular bone score correlated with spine, hip, and ultradistal radius bone mineral density by dual-energy x-ray absorptiometry and cortical area, density, thickness, and porosity; trabecular density, thickness, separation, and heterogeneity; and stiffness and failure load by high-resolution peripheral computed tomography

  16. Prediction of mechanical properties of trabecular bone using quantitative MRI

    International Nuclear Information System (INIS)

    Lammentausta, E; Hakulinen, M A; Jurvelin, J S; Nieminen, M T

    2006-01-01

    Techniques for quantitative magnetic resonance imaging (MRI) have been developed for non-invasive estimation of the mineral density and structure of trabecular bone. The R* 2 relaxation rate (i.e. 1/T* 2 ) is sensitive to bone mineral density (BMD) via susceptibility differences between trabeculae and bone marrow, and by binarizing MRI images, structural variables, such as apparent bone volume fraction, can be assessed. In the present study, trabecular bone samples of human patellae were investigated in vitro at 1.5 T to determine the ability of MRI-derived variables (R* 2 and bone volume fraction) to predict the mechanical properties (Young's modulus, yield stress and ultimate strength). Further, the MRI variables were correlated with reference measurements of volumetric BMD and bone area fraction as determined with a clinical pQCT system. The MRI variables correlated significantly (p 2 and MRI-derived bone volume fraction further improved the prediction of yield stress and ultimate strength. Although pQCT showed a trend towards better prediction of the mechanical properties, current results demonstrate the feasibility of combined MR imaging of marrow susceptibility and bone volume fraction in predicting the mechanical strength of trabecular bone and bone mineral density

  17. Radiographic evaluation of 19 patients with Paprosky 3A and 3B submitted to acetabular review with trabecular metal wedge

    Directory of Open Access Journals (Sweden)

    Carlos Eduardo Benvindo Rosal da Fonseca Neto

    Full Text Available ABSTRACT Objective: This study is aimed at evaluating the fixation of trabecular metal wedges in patients who underwent revision of total hip arthroplasty with large acetabular bone defects. Methods: The radiographs of 19 patients (21 hips, who underwent revision of total hip arthroplasty using trabecular metal wedges from September 2010 to December 2014 were evaluated. This study included only cases of Paprosky 3A and 3B. Preoperative and postoperative images were analyzed. Non-fixation of the implant was defined by the presence of angular variation of the component higher 10 degrees or displacement greater than 6 mm. Patients with follow-up times of less than 24 months or who did not attend the last two appointments were excluded from the study. Results: The mean follow-up time was 39.4 months (25-61. Fixation was achieved in all cases despite its complexity. There was only one case of dislocation that was treated with open reduction. One case developed infection, and was surgically approached on two occasions, with extensive debridement and intravenous antibiotics following protocol, with good evolution. Conclusion: The implanted trabecular metal wedges showed excellent results in the short- and medium-term and may represent another option in the reconstruction of large acetabular defects, sometimes replacing bone reconstruction that uses bone tissue banks or autologous graft.

  18. Structure model index does not measure rods and plates in trabecular bone

    Directory of Open Access Journals (Sweden)

    Phil L Salmon

    2015-10-01

    Full Text Available Structure model index (SMI is widely used to measure rods and plates in trabecular bone. It exploits the change in surface curvature that occurs as a structure varies from spherical (SMI = 4, to cylindrical (SMI = 3 to planar (SMI = 0. The most important assumption underlying SMI is that the entire bone surface is convex and that the curvature differential is positive at all points on the surface. The intricate connections within the trabecular continuum suggest that a high proportion of the surface could be concave, violating the assumption of convexity and producing regions of negative differential. We implemented SMI in the BoneJ plugin and included the ability to measure the amounts of surface that increased or decreased in area after surface mesh dilation, and the ability to visualize concave and convex regions. We measured SMI and its positive (SMI+ and negative (SMI- components, bone volume fraction (BV/TV, the fraction of the surface that is concave (CF, and mean ellipsoid factor (EF in trabecular bone using 38 X-ray microtomography (XMT images from a rat ovariectomy model of sex steroid rescue of bone loss, and 169 XMT images from a broad selection of 87 species' femora (mammals, birds, and a crocodile. We simulated bone resorption by eroding an image of elephant trabeculae and recording SMI and BV/TV at each erosion step. Up to 70%, and rarely less than 20%, of the trabecular surface is concave (CF 0.155 – 0.700. SMI is unavoidably influenced by aberrations from SMI-, which is strongly correlated with BV/TV and CF. The plate-to-rod transition in bone loss is an erroneous observation resulting from SMI's close and artefactual relationship with BV/TV. SMI cannot discern between the distinctive trabecular geometries typical of mammalian and avian bone, whereas EF clearly detects birds' more plate-like trabeculae. EF is free from confounding relationships with BV/TV and CF. SMI results reported in the literature should be treated with

  19. Micro-finite-element method to assess elastic properties of trabecular bone at micro- and macroscopic level.

    Science.gov (United States)

    Rieger, R; Auregan, J C; Hoc, T

    2018-03-01

    The objective of the present study is to assess the mechanical behavior of trabecular bone based on microCT imaging and micro-finite-element analysis. In this way two methods are detailed: (i) direct determination of macroscopic elastic property of trabecular bone; (ii) inverse approach to assess mechanical properties of trabecular bone tissue. Thirty-five females and seven males (forty-two subjects) mean aged (±SD) 80±11.7 years from hospitals of Assistance publique-Hôpitaux de Paris (AP-HP) diagnosed with osteoporosis following a femoral neck fracture due to a fall from standing were included in this study. Fractured heads were collected during hip replacement surgery. Standardized bone cores were removed from the femoral head's equator by a trephine in a water bath. MicroCT images acquisition and analysis were performed with CTan ® software and bone volume fraction was then determined. Micro-finite-element simulations were per-formed using Abaqus 6.9-2 ® software in order to determine the macroscopic mechanical behaviour of the trabecular bone. After microCT acquisition, a longitudinal compression test was performed and the experimental macroscopic Young's Modulus was extracted. An inverse approach based on the whole trabecular bone's mechanical response and micro-finite-element analysis was performed to determine microscopic mechanical properties of trabecular bone. In the present study, elasticity of the tissue was shown to be similar to that of healthy tissue but with a lower yield stress. Classical histomorphometric analysis form microCT imaging associated with an inverse micro-finite-element method allowed to assess microscopic mechanical trabecular bone parameters. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  20. Trabecular bone structure and strength - remodelling and repair

    DEFF Research Database (Denmark)

    Mosekilde, Lis; Ebbesen, Ebbe Nils; Erikstrup, Lise Tornvig

    2000-01-01

    The strength of the spinal trabecular bone declines by a factor of 4-5 from the age of 20 to 80 years. At the same time, the volumetric (apparent) density declines by a factor of only 2. This discrepancy can be explained by the known power relationship between density and strength; this power rel......; and the hydraulic effect of the bone marrow. In order to answer these questions, more in vitro and in vivo studies on human bone in relation to aging, to immobilisation, to exercise and in relation to different treatment regimens are needed.......The strength of the spinal trabecular bone declines by a factor of 4-5 from the age of 20 to 80 years. At the same time, the volumetric (apparent) density declines by a factor of only 2. This discrepancy can be explained by the known power relationship between density and strength; this power...

  1. Intraoperative optical coherence tomography and ab interno trabecular meshwork surgery with the Trabectome

    Directory of Open Access Journals (Sweden)

    Junker B

    2017-09-01

    Full Text Available Bernd Junker,1 Jens F Jordan,2 Carsten Framme,1 Amelie Pielen1 1University Eye Hospital, Medical School Hannover, Hannover, 2Eye Center, Medical Center, University of Freiburg, Freiburg, Germany Importance: This study is the first description of the use of the intraoperative optical coherence tomography (iOCT for trabecular meshwork surgery with the Trabectome in a regular clinical setting.Background: The aim of this study is to evaluate intraoperatively the immediate success of ab interno trabeculotomy with the Trabectome defined as a removal of the trabecular meshwork.Design: This is a retrospective clinical study performed in the University Eye Hospital, Medical School Hannover.Participants: A total of nine consecutive Caucasian patients suffering from primary open angle glaucoma, pigment dispersion glaucoma, or pseudoexfoliation glaucoma took part in the study.Methods: All patients underwent ab interno trabeculotomy surgery with the Trabectome using a commercially available iOCT to visualize the anterior chamber angle (ACA before and after the procedure. The visualization was done using a modified Swan-Jacobs lens (all nine patients or without lens (view from above, five patients.Main outcome measures: The main outcome of this study is the success of visualization of the ACA on iOCT, especially the postprocedural visualization of the wound gap after removal of the trabecular meshwork.Results: Using the view from above, the ACA could be visualized before and after the procedure in only two of the five cases. Using the modified Swan-Jacobs lens, the ACA could be visualized before the procedure and the trabecular meshwork opening after the procedure in all nine patients.Conclusion: The iOCT can be used to objectify the immediate success of the surgical procedure, ie, the removal of the trabecular meshwork, of ab interno trabeculotomy with the Trabectome. The procedure itself cannot be captured sufficiently via iOCT. Keywords: glaucoma, imaging

  2. Influence of Trabecular Bone on Peri-Implant Stress and Strain Based on Micro-CT Finite Element Modeling of Beagle Dog.

    Science.gov (United States)

    Liao, Sheng-Hui; Zhu, Xing-Hao; Xie, Jing; Sohodeb, Vikesh Kumar; Ding, Xi

    2016-01-01

    The objective of this investigation is to analyze the influence of trabecular microstructure modeling on the biomechanical distribution of the implant-bone interface. Two three-dimensional finite element mandible models, one with trabecular microstructure (a refined model) and one with macrostructure (a simplified model), were built. The values of equivalent stress at the implant-bone interface in the refined model increased compared with those of the simplified model and strain on the contrary. The distributions of stress and strain were more uniform in the refined model of trabecular microstructure, in which stress and strain were mainly concentrated in trabecular bone. It was concluded that simulation of trabecular bone microstructure had a significant effect on the distribution of stress and strain at the implant-bone interface. These results suggest that trabecular structures could disperse stress and strain and serve as load buffers.

  3. Assessment of jawbone trabecular bone structure amongst osteoporotic women by cone-beam computed tomography: the OSTEOSYR project.

    Science.gov (United States)

    Barngkgei, Imad; Al Haffar, Iyad; Shaarani, Eyad; Khattab, Razan; Mashlah, Ammar

    2016-11-01

    To assess the trabecular bone structure of jawbones and the dens (the odontoid process of the second cervical vertebra) amongst osteoporotic and nonosteoporotic women using cone-beam computed tomography (CBCT). Analysis of the dens trabecular bone structure aimed to test the validity of CBCT in such analysis. Thirty-eight women who went under dual-energy X-ray absorptiometry (DXA) examination were scanned by CBCT. Cuboids from different areas of jawbones and the dens were extracted from each scan. Trabecular thickness (Tb.Th), trabecular separation (Tb.S), bone volume fraction (BV/TV), specific bone surface (BS/TV) and connectivity density were calculated. Student's t-test, Pearson correlation, and logistic regression analysis were used to explore differences in these measures between groups. Jawbone-derived measures showed insignificant differences (P > 0.05) between osteoporotic and non-osteoporotic groups, and weak correlations with femoral neck and lumbar vertebrae T-scores (r ≤ 0.4). Dens-derived measures, however, resulted in the opposite (r = 0.34-0.38 [P value = 0.02-0.036] and r = 0.48-0.61 [P value ≤ 0.003]) and the highest accuracy of osteoporosis prediction: 84.2% and 78.9% respectively. Trabecular bone structure of the mandible and maxilla is not affected in osteoporosis as assessed by CBCT. Dens trabecular bone analysis revealed the opposite, so some trabecular bone measures may be assessed by CBCT, which may aid in predicting osteoporosis. © 2015 Wiley Publishing Asia Pty Ltd.

  4. Variability of morphometric parameters of human trabecular tissue from coxo-arthritis and osteoporotic samples

    Directory of Open Access Journals (Sweden)

    Franco Marinozzi

    2012-01-01

    Full Text Available Morphometric and architectural bone parameters change in diseases such as osteoarthritis and osteoporosis. The mechanical strength of bone is primarily influenced by bone quantity and quality. Bone quality is defined by parameters such as trabecular thickness, trabecular separation, trabecular density and degree of anisotropy that describe the micro-architectural structure of bone. Recently, many studies have validated microtomography as a valuable investigative technique to assess bone morphometry, thanks to micro-CT non-destructive, non-invasive and reliability features, in comparison to traditional techniques such as histology. The aim of this study is the analysis by micro-computed tomography of six specimens, extracted from patients affected by osteoarthritis and osteoporosis, in order to observe the tridimensional structure and calculate several morphometric parameters.

  5. Total water, phosphorus relaxation and inter-atomic organic to inorganic interface are new determinants of trabecular bone integrity.

    Directory of Open Access Journals (Sweden)

    Ratan Kumar Rai

    Full Text Available Bone is the living composite biomaterial having unique structural property. Presently, there is a considerable gap in our understanding of bone structure and composition in the native state, particularly with respect to the trabecular bone, which is metabolically more active than cortical bones, and is readily lost in post-menopausal osteoporosis. We used solid-state nuclear magnetic resonance (NMR to compare trabecular bone structure and composition in the native state between normal, bone loss and bone restoration conditions in rat. Trabecular osteopenia was induced by lactation as well as prolonged estrogen deficiency (bilateral ovariectomy, Ovx. Ovx rats with established osteopenia were administered with PTH (parathyroid hormone, trabecular restoration group, and restoration was allowed to become comparable to sham Ovx (control group using bone mineral density (BMD and µCT determinants. We used a technique combining (1H NMR spectroscopy with (31P and (13C to measure various NMR parameters described below. Our results revealed that trabecular bones had diminished total water content, inorganic phosphorus NMR relaxation time (T1 and space between the collagen and inorganic phosphorus in the osteopenic groups compared to control, and these changes were significantly reversed in the bone restoration group. Remarkably, bound water was decreased in both osteopenic and bone restoration groups compared to control. Total water and T1 correlated strongly with trabecular bone density, volume, thickness, connectivity, spacing and resistance to compression. Bound water did not correlate with any of the microarchitectural and compression parameters. We conclude that total water, T1 and atomic space between the crystal and organic surface are altered in the trabecular bones of osteopenic rats, and PTH reverses these parameters. Furthermore, from these data, it appears that total water and T1 could serve as trabecular surrogates of micro-architecture and

  6. Measurement of the speed of sound in trabecular bone by using a time reversal acoustics focusing system

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kang Il [Kangwon National University, Chuncheon (Korea, Republic of); Choi, Bok-Kyoung [Maritime Security Research Center, KIOST, Ansan (Korea, Republic of)

    2014-10-15

    A new method for measuring the speed of sound (SOS) in trabecular bone by using a time reversal acoustics (TRA) focusing system was proposed and validated with measurements obtained by using the conventional pulse-transmission technique. The SOS measured in 14 bovine femoral trabecular bone samples by using the two methods was highly correlated each other, although the SOS measured by using the TRA focusing system was slightly lower by an average of 2.2 m/s. The SOS measured by using the two methods showed high correlation coefficients of r = 0.92 with the apparent bone density, consistent with the behavior in human trabecular bone in vitro. These results prove the efficacy of the new method based on the principle of TRA to measure the SOS in trabecular bone.

  7. Contribution of mechanical unloading to trabecular bone loss following non-invasive knee injury in mice.

    Science.gov (United States)

    Anderson, Matthew J; Diko, Sindi; Baehr, Leslie M; Baar, Keith; Bodine, Sue C; Christiansen, Blaine A

    2016-10-01

    Development of osteoarthritis commonly involves degeneration of epiphyseal trabecular bone. In previous studies, we observed 30-44% loss of epiphyseal trabecular bone (BV/TV) from the distal femur within 1 week following non-invasive knee injury in mice. Mechanical unloading (disuse) may contribute to this bone loss; however, it is unclear to what extent the injured limb is unloaded following injury, and whether disuse can fully account for the observed magnitude of bone loss. In this study, we investigated the contribution of mechanical unloading to trabecular bone changes observed following non-invasive knee injury in mice (female C57BL/6N). We investigated changes in gait during treadmill walking, and changes in voluntary activity level using Open Field analysis at 4, 14, 28, and 42 days post-injury. We also quantified epiphyseal trabecular bone using μCT and weighed lower-limb muscles to quantify atrophy following knee injury in both ground control and hindlimb unloaded (HLU) mice. Gait analysis revealed a slightly altered stride pattern in the injured limb, with a decreased stance phase and increased swing phase. However, Open Field analysis revealed no differences in voluntary movement between injured and sham mice at any time point. Both knee injury and HLU resulted in comparable magnitudes of trabecular bone loss; however, HLU resulted in considerably more muscle loss than knee injury, suggesting another mechanism contributing to bone loss following injury. Altogether, these data suggest that mechanical unloading likely contributes to trabecular bone loss following non-invasive knee injury, but the magnitude of this bone loss cannot be fully explained by disuse. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:1680-1687, 2016. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  8. Translimbal laser photocoagulation to the trabecular meshwork as a model of glaucoma in rats.

    Science.gov (United States)

    Levkovitch-Verbin, Hana; Quigley, Harry A; Martin, Keith R G; Valenta, Danielle; Baumrind, Lisa A; Pease, Mary Ellen

    2002-02-01

    To develop and characterize a model of pressure-induced optic neuropathy in rats. Experimental glaucoma was induced unilaterally in 174 Wistar rats, using a diode laser with wavelength of 532 nm aimed at the trabecular meshwork and episcleral veins (combination treatment group) or only at the trabecular meshwork (trabecular group) through the external limbus. Intraocular pressure (IOP) was measured by a tonometer in rats under ketamine-xylazine anesthesia. Possible retinal vascular compromise was evaluated by repeated fundus examinations and by histology. The degree of retinal ganglion cell (RGC) loss was assessed by a masked, semiautomated counting of optic nerve axons. Effects of laser treatment on anterior ocular structures and retina were judged by light microscopy. After the laser treatment, IOP was increased in all eyes to higher than the normal mean IOP of 19.4 +/- 2.1 mm Hg (270 eyes). Peak IOP was 49.0 +/- 6.1 mm Hg (n = 108) in the combination group that was treated by a laser setting of 0.7 seconds and 0.4 W and 34.0 +/- 5.7 mm Hg (n = 46) in the trabecular group. Mean IOP after 6 weeks was 25.5 +/- 2.9 mm Hg in glaucomatous eyes in the combination group compared with 22.0 +/- 1.8 mm Hg in the trabecular group. IOP in the glaucomatous eyes was typically higher than in the control eyes for at least 3 weeks. In the combination group, RGC loss was 16.1% +/- 14.4% at 1 week (n = 8, P = 0.01), 59.7% +/- 25.7% at 6 weeks (n = 88, P < 0.001), and 70.9% +/- 23.6% at 9 weeks (n = 12, P < 0.001). The trabecular group had mean axonal loss of 19.1% +/- 14.0% at 3 weeks (n = 9, P = 0.004) and 24.3% +/- 20.2% at 6 weeks (n = 25, P < 0.001), increasing to 48.4% +/- 32.8% at 9 weeks (n = 12, P < 0.001). Laser treatment led to closure of intertrabecular spaces and the major outflow channel. The retina and choroid were normal by ophthalmoscopy at all times after treatment. Light microscopic examination showed only loss of RGCs and their nerve fibers. Increased IOP caused

  9. Acute hypothalamic suppression significantly affects trabecular bone but not cortical bone following recovery and ovariectomy surgery in a rat model

    Directory of Open Access Journals (Sweden)

    Vanessa R. Yingling

    2016-01-01

    Full Text Available Background. Osteoporosis is “a pediatric disease with geriatric consequences.” Bone morphology and tissue quality co-adapt during ontogeny for sufficient bone stiffness. Altered bone morphology from hypothalamic amenorrhea, a risk factor for low bone mass in women, may affect bone strength later in life. Our purpose was to determine if altered morphology following hypothalamic suppression during development affects cortical bone strength and trabecular bone volume (BV/TV at maturity.Methods. Female rats (25 days old were assigned to a control (C group (n = 45 that received saline injections (.2 cc or an experimental group (GnRH-a (n = 45 that received gonadotropin releasing hormone antagonist injections (.24 mg per dose for 25 days. Fifteen animals from each group were sacrificed immediately after the injection protocol at Day 50 (C, GnRH-a. The remaining animals recovered for 135 days and a subset of each group was sacrificed at Day 185 ((C-R (n = 15 and (G-R (n = 15. The remaining animals had an ovariectomy surgery (OVX at 185 days of age and were sacrificed 40 days later (C-OVX (n = 15 and (G-OVX (n = 15. After sacrifice femurs were mechanically tested and scanned using micro CT. Serum C-terminal telopeptides (CTX and insulin-like growth factor 1 (IGF-1 were measured. Two-way ANOVA (2 groups (GnRH-a and Control X 3 time points (Injection Protocol, Recovery, post-OVX was computed.Results. GnRH-a injections suppressed uterine weights (72% and increased CTX levels by 59%. Bone stiffness was greater in the GnRH-a groups compared to C. Ash content and cortical bone area were similar between groups at all time points. Polar moment of inertia, a measure of bone architecture, was 15% larger in the GnRH-a group and remained larger than C (19% following recovery. Both the polar moment of inertia and cortical area increased linearly with the increases in body weight. Following the injection protocol, trabecular BV/TV was 31% lower in the Gn

  10. In vitro and in vivo experimental studies on trabecular meshwork degeneration induced by benzalkonium chloride (an American Ophthalmological Society thesis).

    Science.gov (United States)

    Baudouin, Christophe; Denoyer, Alexandre; Desbenoit, Nicolas; Hamm, Gregory; Grise, Alice

    2012-12-01

    Long-term antiglaucomatous drug administration may cause irritation, dry eye, allergy, subconjunctival fibrosis, or increased risk of glaucoma surgery failure, potentially due to the preservative benzalkonium chloride (BAK), whose toxic, proinflammatory, and detergent effects have extensively been shown experimentally. We hypothesize that BAK also influences trabecular meshwork (TM) degeneration. Trabecular specimens were examined using immunohistology and reverse transcriptase-polymerase chain reaction. A trabecular cell line was stimulated by BAK and examined for apoptosis, oxidative stress, fractalkine and SDF-1 expression, and modulation of their receptors. An experimental model was developed with BAK subconjunctival injections to induce TM degeneration. Mass spectrometry (MS) imaging assessed BAK penetration after repeated instillations in rabbit eyes. Trabecular specimens showed extremely low densities of trabecular cells and presence of cells expressing fractalkine and fractalkine receptor and their respective mRNAs. Benzalkonium in vitro induced apoptosis, oxidative stress, and fractalkine expression and inhibited the protective chemokine SDF-1 and Bcl2, also inducing a sustained intraocular pressure (IOP) increase, with dramatic apoptosis of trabecular cells and reduction of aqueous outflow. MS imaging showed that BAK could access the TM at measurable levels after repeated instillations. BAK enhances all characteristics of TM degeneration typical of glaucoma-trabecular apoptosis, oxidative stress, induction of inflammatory chemokines-and causes degeneration in acute experimental conditions, potentially mimicking long-term accumulation. BAK was also shown to access the TM after repeated instillations. These findings support the hypothesis that antiglaucoma medications, through toxicity of their preservative, may cause further long-term trabecular degeneration and therefore enhance outflow resistance, reducing the impact of IOP-lowering agents.

  11. NUMERICAL AND MECHANICAL ANALYSES OF A 3D-PRINTED TITANIUM TRABECULAR DENTAL IMPLANT

    Directory of Open Access Journals (Sweden)

    Luboš Řehounek

    2017-06-01

    Full Text Available The main focus of this paper is to investigate and describe a novel biomaterial structure. The trabecular structure has only recently been recognized as a viable alternative for prostheses and implants and seems to have very promising biocompatibility and mechanical properties. The 3D printing technique was used to create test specimens. These specimens were then tested by nanoindentation and tensile and compression tests. A numerical model was created and curve-fitted to represent the mechanical behavior of the trabecular structure. A significant reduction in the values of Young’s modulus E was observed. The values of E for conventional implant materials are approximately 110–120GPa and the trabecular structure reached a value just below 1GPa. The next effort will be to apply the model onto a real implant. It is the “four leaf clover” implant variant by authors F. Denk Jr., A. Jíra and F. Denk Sr.

  12. Pregnant ewes exposed to multiple endocrine disrupting pollutants through sewage sludge-fertilized pasture show an anti-estrogenic effect in their trabecular bone

    Energy Technology Data Exchange (ETDEWEB)

    Lind, P. Monica, E-mail: Monica.Lind@medsci.uu.se [Department of Medical Sciences, Occupational and Environmental Medicine, Uppsala University, Ullerakersvaegen 40, 751 85 Uppsala (Sweden); Oberg, Denise [Department of Environmental Toxicology, Uppsala University, Uppsala (Sweden); Larsson, Sune [Department of Orthopaedics, Uppsala University, Uppsala (Sweden); Kyle, Carol E. [Macaulay Land Use Research Institute, Craigiebuckler, Aberdeen AB15 8QH (United Kingdom); Orberg, Jan [Department of Environmental Toxicology, Uppsala University, Uppsala (Sweden); Rhind, Stewart M. [Macaulay Land Use Research Institute, Craigiebuckler, Aberdeen AB15 8QH (United Kingdom)

    2010-05-01

    Pregnant ewes were maintained on pastures fertilized, twice yearly, with either sewage sludge (2.25 tonnes dry matter/ha; Treated; T) or inorganic fertilizer containing equivalent amounts of nitrogen (Control; C), to determine effects on maternal and fetal bone structures, density and mechanical properties of exposure to environmental concentrations of multiple endocrine disrupting compounds (EDCs) and heavy metal pollutants. The ewes were maintained on the respective pastures from the age of about 8 months until they were 4-6 years of age and they were slaughtered at 110 d gestation. Metaphyseal parts of adult ewe femurs exhibited a significantly reduced mean, total cross sectional area (CSA, - 4%; p < 0.05), lower trabecular bone mineral content (BMC, mg/mm; - 18%; p < 0.05), trabecular bone mineral density (BMD, mg/cm{sup 3}, - 8.0%; p < 0.05) and trabecular CSA, mm{sup 2}, - 11.1%; p < 0.05) in T compared with C animals. Femurs of T ewes were stronger than those of C ewes but this may reflect greater body weights. At the mid-diaphyseal part of the fetal bones, there was a reduction in endosteal circumference (- 6.7%, p < 0.05) and marrow cavity area (- 13.8%, p < 0.05) in the female T fetuses compared with female C fetuses. In the male fetuses the mid-diaphyseal part total bone mineral content was higher (+ 3.0%, p < 0.05) in T than in C animals. No treatment difference in biomechanical bending was detected in the fetuses. It is concluded that ewes grazing pasture fertilized with sewage sludge exhibited an anti-estrogenic effect on their trabecular bone in the form of reduced mineral content and density, despite increased body weight. It is suggested that human exposure to low levels of multiple EDCs may have implications for bone structure and human health.

  13. Fractal analysis of mandibular trabecular bone: optimal tile sizes for the tile counting method.

    Science.gov (United States)

    Huh, Kyung-Hoe; Baik, Jee-Seon; Yi, Won-Jin; Heo, Min-Suk; Lee, Sam-Sun; Choi, Soon-Chul; Lee, Sun-Bok; Lee, Seung-Pyo

    2011-06-01

    This study was performed to determine the optimal tile size for the fractal dimension of the mandibular trabecular bone using a tile counting method. Digital intraoral radiographic images were obtained at the mandibular angle, molar, premolar, and incisor regions of 29 human dry mandibles. After preprocessing, the parameters representing morphometric characteristics of the trabecular bone were calculated. The fractal dimensions of the processed images were analyzed in various tile sizes by the tile counting method. The optimal range of tile size was 0.132 mm to 0.396 mm for the fractal dimension using the tile counting method. The sizes were closely related to the morphometric parameters. The fractal dimension of mandibular trabecular bone, as calculated with the tile counting method, can be best characterized with a range of tile sizes from 0.132 to 0.396 mm.

  14. Long range node-strut analysis of trabecular bone microarchitecture

    DEFF Research Database (Denmark)

    Schmah, Tanya; Marwan, Norbert; Thomsen, Jesper Skovhus

    2011-01-01

    PURPOSE: We present a new morphometric measure of trabecular bone microarchitecture, called mean node strength (NdStr), which is part of a newly developed approach called long range node-strut analysis. Our general aim is to describe and quantify the apparent "latticelike" microarchitecture of th...

  15. Age-related changes in cortical and trabecular bone mineral status: A quantitative CT study in lumbar vertebrae

    International Nuclear Information System (INIS)

    Tanno, M.; Horiuchi, T.; Nakajima, I.; Maeda, S.; Igarashi, M.; Yamada, H.

    2000-01-01

    To investigate the age and sex dependence of the bone mineral status of human lumbar vertebrae with special regard to differences between cortical and trabecular bone. The study group comprised 125 normal Japanese healthy volunteers (54 males and 71 females), and was subdivided into adult male and female groups (subjects younger than 40 years), intermediate male and female groups (ages ranging between 41 and 64 years) and old male and female groups (subjects older than 65 years). The cortical bone mineral status was estimated using a single-energy quantitative CT (SE-QCT) technique, whereas trabecular bone mineral density (BMD) was estimated using a dual-energy (DE-QCT) technique. A considerable gender difference in the age-related cortical bone status was found. There was a significant reduction of the mean values of the cortical volume and BMD in the old female group compared with those obtained in the old male group. The results suggest that in men, cortical and trabecular bone volume decrease very little with age. In women, cortical volume and BMD and trabecular BMD decrease with age while trabecular bone volume does not. The study showed that all variables had higher values in men than in women and that the difference increased with age

  16. Diagnosis of osteoarthritis and prognosis of tibial cartilage loss by quantification of tibia trabecular bone from MRI

    DEFF Research Database (Denmark)

    Marques, Joselene; Genant, Harry K.; Lillholm, Martin

    2013-01-01

    loss were assessed by a segmentation process. Aiming to quantify and potentially capture the structure of the trabecular bone anatomy, a machine learning approach used a set of texture features for training a classifier to recognize the trabecular bone of a knee with radiographic osteoarthritis. Using...

  17. Osteoporosis imaging: effects of bone preservation on MDCT-based trabecular bone microstructure parameters and finite element models

    International Nuclear Information System (INIS)

    Baum, Thomas; Grande Garcia, Eduardo; Burgkart, Rainer; Gordijenko, Olga; Liebl, Hans; Jungmann, Pia M.; Gruber, Michael; Zahel, Tina; Rummeny, Ernst J.; Waldt, Simone; Bauer, Jan S.

    2015-01-01

    Osteoporosis is defined as a skeletal disorder characterized by compromised bone strength due to a reduction of bone mass and deterioration of bone microstructure predisposing an individual to an increased risk of fracture. Trabecular bone microstructure analysis and finite element models (FEM) have shown to improve the prediction of bone strength beyond bone mineral density (BMD) measurements. These computational methods have been developed and validated in specimens preserved in formalin solution or by freezing. However, little is known about the effects of preservation on trabecular bone microstructure and FEM. The purpose of this observational study was to investigate the effects of preservation on trabecular bone microstructure and FEM in human vertebrae. Four thoracic vertebrae were harvested from each of three fresh human cadavers (n = 12). Multi-detector computed tomography (MDCT) images were obtained at baseline, 3 and 6 month follow-up. In the intervals between MDCT imaging, two vertebrae from each donor were formalin-fixed and frozen, respectively. BMD, trabecular bone microstructure parameters (histomorphometry and fractal dimension), and FEM-based apparent compressive modulus (ACM) were determined in the MDCT images and validated by mechanical testing to failure of the vertebrae after 6 months. Changes of BMD, trabecular bone microstructure parameters, and FEM-based ACM in formalin-fixed and frozen vertebrae over 6 months ranged between 1.0–5.6 % and 1.3–6.1 %, respectively, and were not statistically significant (p > 0.05). BMD, trabecular bone microstructure parameters, and FEM-based ACM as assessed at baseline, 3 and 6 month follow-up correlated significantly with mechanically determined failure load (r = 0.89–0.99; p < 0.05). The correlation coefficients r were not significantly different for the two preservation methods (p > 0.05). Formalin fixation and freezing up to six months showed no significant effects on trabecular bone microstructure

  18. Relationships of the phase velocity with the microarchitectural parameters in bovine trabecular bone in vitro: Application of a stratified model

    Science.gov (United States)

    Lee, Kang Il

    2012-08-01

    The present study aims to provide insight into the relationships of the phase velocity with the microarchitectural parameters in bovine trabecular bone in vitro. The frequency-dependent phase velocity was measured in 22 bovine femoral trabecular bone samples by using a pair of transducers with a diameter of 25.4 mm and a center frequency of 0.5 MHz. The phase velocity exhibited positive correlation coefficients of 0.48 and 0.32 with the ratio of bone volume to total volume and the trabecular thickness, respectively, but a negative correlation coefficient of -0.62 with the trabecular separation. The best univariate predictor of the phase velocity was the trabecular separation, yielding an adjusted squared correlation coefficient of 0.36. The multivariate regression models yielded adjusted squared correlation coefficients of 0.21-0.36. The theoretical phase velocity predicted by using a stratified model for wave propagation in periodically stratified media consisting of alternating parallel solid-fluid layers showed reasonable agreements with the experimental measurements.

  19. Effects of different loading patterns on the trabecular bone morphology of the proximal femur using adaptive bone remodeling.

    Science.gov (United States)

    Banijamali, S Mohammad Ali; Oftadeh, Ramin; Nazarian, Ara; Goebel, Ruben; Vaziri, Ashkan; Nayeb-Hashemi, Hamid

    2015-01-01

    In this study, the changes in the bone density of human femur model as a result of different loadings were investigated. The model initially consisted of a solid shell representing cortical bone encompassing a cubical network of interconnected rods representing trabecular bone. A computationally efficient program was developed that iteratively changed the structure of trabecular bone by keeping the local stress in the structure within a defined stress range. The stress was controlled by either enhancing existing beam elements or removing beams from the initial trabecular frame structure. Analyses were performed for two cases of homogenous isotropic and transversely isotropic beams.Trabecular bone structure was obtained for three load cases: walking, stair climbing and stumbling without falling. The results indicate that trabecular bone tissue material properties do not have a significant effect on the converged structure of trabecular bone. In addition, as the magnitude of the loads increase, the internal structure becomes denser in critical zones. Loading associated with the stumbling results in the highest density;whereas walking, considered as a routine daily activity, results in the least internal density in different regions. Furthermore, bone volume fraction at the critical regions of the converged structure is in good agreement with previously measured data obtained from combinations of dual X-ray absorptiometry (DXA) and computed tomography (CT). The results indicate that the converged bone architecture consisting of rods and plates are consistent with the natural bone morphology of the femur. The proposed model shows a promising means to understand the effects of different individual loading patterns on the bone density.

  20. Three-dimensional trabecular bone architecture of the lumbar spine in bone metastasis from prostate cancer: comparison with degenerative sclerosis

    International Nuclear Information System (INIS)

    Tamada, Tsutomu; Sone, Teruki; Imai, Shigeki; Kajihara, Yasumasa; Fukunaga, Masao; Jo, Yoshimasa

    2005-01-01

    Prostate cancer frequently metastasizes to bone, inducing osteosclerotic lesions. The objective of this study was to clarify the three-dimensional (3D) trabecular bone microstructure in bone metastasis from prostate cancer by comparison with normal and degenerative sclerotic bone lesions, using microcomputed tomography (micro-CT). A total of 32 cancellous bone samples were excised from the lumbar spine of six autopsy patients: 15 metastatic samples (one patient), eight degenerative sclerotic samples (four patients) and the rest from normal sites (three patients). The samples were serially scanned cross-sectionally by micro-CT with a pixel size of 23.20 μm, slice thickness of 18.56 μm, and image matrix of 512 x 512. Each image data set consisted of 250 consecutive slices. The volumes of interest (96 x 96 x 120 voxels) were defined in the original image sets and 3D indices of the trabecular microstructure were determined. The trabecular thickness (Tb.Th) in degenerative sclerotic lesions was significantly higher than that in normal sites, whereas no significant difference was observed in trabecular number (Tb.N). By contrast, in metastatic lesions, the Tb.N was significantly higher with increased bone volume fraction (BV/TV) than in normal sites, and no significant difference was found in Tb.Th. The characteristics of the trabecular surface in the metastatic samples showed concave structural elements with an increase in BV/TV, indicating osteolysis of the trabecular bone. In 3D reconstructed images, increased trabecular bone with an irregular surface was observed in samples from metastatic sites, which were uniformly sclerotic on soft X-ray radiographs. These results support, through 3D morphological features, the strong bone resorption effect in bone metastasis from prostate cancer. (orig.)

  1. [Analysis of correlation between trabecular microstructure and clinical imaging parameters in fracture region of osteoporotic hip].

    Science.gov (United States)

    Peng, Jing; Zhou, Yong; Min, Li; Zhang, Wenli; Luo, Yi; Zhang, Xuelei; Zou, Chang; Shi, Rui; Tu, Chongqi

    2014-05-01

    To analyze the correlation between the trabecular microstructure and the clinical imaging parameters in the fracture region of osteoporotic hip so as to provide a simple method to evaluate the trabecular microstructure by a non-invasive way. Between June 2012 and January 2013, 16 elderly patients with femoral neck fracture underwent hip arthroplasty were selected as the trial group; 5 young patients with pelvic fracture were selected as the control group. The hip CT examination was done, and cancellous bone volume/marrow cavity volume (CV/MV) was analyzed with Mimics 10.01 software in the control group. The CT scan and bone mineral density (BMD) measurement were performed on normal hips of the trial group, and cuboid specimens were gained from the femoral necks at the place of the tensional trabeculae to evaluate the trabecular microstructure parameters by Micro-CT, including bone volume fraction (BV/TV), trabecular number (Tb.N), trabecular spacing (Tb.Sp), trabecular thickness (Tb.Th), connect density (Conn.D), and structure model index (SMI). The correlation between imaging parameters and microstructure parameters was analyzed. In the trial group, the BMD value was 0.491-0.698 g/cm2 (mean, 0.601 g/cm2); according to World Health Organization (WHO) standard, 10 cases were diagnosed as having osteoporosis, and 6 cases as having osteopenia. The CV/MV of the trial group (0.670 1 +/- 0.102 0) was significantly lower than that of the control group (0.885 0 +/- 0.089 1) (t = -4.567, P = 0.000). In the trial group, CV/MV had correlation with BV/TV, Tb.Th, and SMI (P 0.05). BV/TV had correlation with Tb.Th, Tb.N, Tb.Sp, and SMI (P microstructure parameters (P > 0.05). CV/MV obviously decreases in the osteoporotic hip, and there is a correlation between CV/MV and the microstructure parameters of BV/TV, Tb.Th, and SMI, to some extent, which can reflect the variety of the microstructure of the trabeculae. There is no correlation between BMD of femoral neck and

  2. Timing of growth hormone treatment affects trabecular bone microarchitecture and mineralization in growth hormone deficient mice.

    Science.gov (United States)

    Kristensen, Erika; Hallgrímsson, Benedikt; Morck, Douglas W; Boyd, Steven K

    2010-08-01

    Growth hormone (GH) is essential in the development of bone mass, and a growth hormone deficiency (GHD) in childhood is frequently treated with daily injections of GH. It is not clear what effect GHD and its treatment has on bone. It was hypothesized that GHD would result in impaired microarchitecture, and an early onset of treatment would result in a better recovery than late onset. Growth hormone deficient homozygous (lit/lit) mice of both sexes were divided into two treatment groups receiving daily injections of GH, starting at an early (21 days of age) or a late time point (35 days of age, corresponding to the end of puberty). A group of heterozygous mice with normal levels of growth hormone served as controls. In vivo micro-computed tomography scans of the fourth lumbar vertebra were obtained at five time points between 21 and 60 days of age, and trabecular morphology and volumetric BMD were analyzed to determine the effects of GH on bone microarchitecture. Early GH treatment led to significant improvements in bone volume ratio (p=0.006), tissue mineral density (p=0.005), and structure model index (p=0.004) by the study endpoint (day 60), with no detected change in trabecular thickness. Trabecular number increased and trabecular separation decreased in GHD mice regardless of treatment compared to heterozygous mice. This suggests fundamental differences in the structure of trabecular bone in GHD and GH treated mice, reflected by an increased number of thinner trabeculae in these mice compared to heterozygous controls. There were no significant differences between the late treatment group and GHD mice except for connectivity density. Taken together, these results indicate that bone responds to GH treatment initiated before puberty but not to treatment commencing post-puberty, and that GH treatment does not rescue the structure of trabecular bone to that of heterozygous controls. Copyright 2010 Elsevier Inc. All rights reserved.

  3. A synchrotron radiation microtomography system for the analysis of trabecular bone samples.

    Science.gov (United States)

    Salomé, M; Peyrin, F; Cloetens, P; Odet, C; Laval-Jeantet, A M; Baruchel, J; Spanne, P

    1999-10-01

    X-ray computed microtomography is particularly well suited for studying trabecular bone architecture, which requires three-dimensional (3-D) images with high spatial resolution. For this purpose, we describe a three-dimensional computed microtomography (microCT) system using synchrotron radiation, developed at ESRF. Since synchrotron radiation provides a monochromatic and high photon flux x-ray beam, it allows high resolution and a high signal-to-noise ratio imaging. The principle of the system is based on truly three-dimensional parallel tomographic acquisition. It uses a two-dimensional (2-D) CCD-based detector to record 2-D radiographs of the transmitted beam through the sample under different angles of view. The 3-D tomographic reconstruction, performed by an exact 3-D filtered backprojection algorithm, yields 3-D images with cubic voxels. The spatial resolution of the detector was experimentally measured. For the application to bone investigation, the voxel size was set to 6.65 microm, and the experimental spatial resolution was found to be 11 microm. The reconstructed linear attenuation coefficient was calibrated from hydroxyapatite phantoms. Image processing tools are being developed to extract structural parameters quantifying trabecular bone architecture from the 3-D microCT images. First results on human trabecular bone samples are presented.

  4. Contribution of mechanical unloading to trabecular bone loss following non-invasive knee injury in mice

    OpenAIRE

    Anderson, Matthew J.; Diko, Sindi; Baehr, Leslie M.; Baar, Keith; Bodine, Sue C.; Christiansen, Blaine A.

    2016-01-01

    Development of osteoarthritis commonly involves degeneration of epiphyseal trabecular bone. In previous studies, we observed 30–44% loss of epiphyseal trabecular bone (BV/TV) from the distal femur within one week following non-invasive knee injury in mice. Mechanical unloading (disuse) may contribute to this bone loss, however it is unclear to what extent the injured limb is unloaded following injury, and whether disuse can fully account for the observed magnitude of bone loss. In this study,...

  5. Relationships of the phase velocity with the micro architectural parameters in bovine trabecular bone in vitro: application of a stratified model

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kang Il [Kangwon National University, Chuncheon (Korea, Republic of)

    2012-08-15

    The present study aims to provide insight into the relationships of the phase velocity with the micro architectural parameters in bovine trabecular bone in vitro. The frequency-dependent phase velocity was measured in 22 bovine femoral trabecular bone samples by using a pair of transducers with a diameter of 25.4 mm and a center frequency of 0.5 MHz. The phase velocity exhibited positive correlation coefficients of 0.48 and 0.32 with the ratio of bone volume to total volume and the trabecular thickness, respectively, but a negative correlation coefficient of -0.62 with the trabecular separation. The best univariate predictor of the phase velocity was the trabecular separation, yielding an adjusted squared correlation coefficient of 0.36. The multivariate regression models yielded adjusted squared correlation coefficients of 0.21 - 0.36. The theoretical phase velocity predicted by using a stratified model for wave propagation in periodically stratified media consisting of alternating parallel solid-fluid layers showed reasonable agreements with the experimental measurements.

  6. Relationships of the phase velocity with the micro architectural parameters in bovine trabecular bone in vitro: application of a stratified model

    International Nuclear Information System (INIS)

    Lee, Kang Il

    2012-01-01

    The present study aims to provide insight into the relationships of the phase velocity with the micro architectural parameters in bovine trabecular bone in vitro. The frequency-dependent phase velocity was measured in 22 bovine femoral trabecular bone samples by using a pair of transducers with a diameter of 25.4 mm and a center frequency of 0.5 MHz. The phase velocity exhibited positive correlation coefficients of 0.48 and 0.32 with the ratio of bone volume to total volume and the trabecular thickness, respectively, but a negative correlation coefficient of -0.62 with the trabecular separation. The best univariate predictor of the phase velocity was the trabecular separation, yielding an adjusted squared correlation coefficient of 0.36. The multivariate regression models yielded adjusted squared correlation coefficients of 0.21 - 0.36. The theoretical phase velocity predicted by using a stratified model for wave propagation in periodically stratified media consisting of alternating parallel solid-fluid layers showed reasonable agreements with the experimental measurements.

  7. Experimental erbium: YAG laser photoablation of trabecular meshwork in rabbits: an in-vivo study.

    Science.gov (United States)

    Dietlein, T S; Jacobi, P C; Schröder, R; Krieglstein, G K

    1997-05-01

    Photoablative laser trabecular surgery has been proposed as an outflow-enhancing treatment for open-angle glaucoma. The aim of the study was to investigate the time course of repair response following low-thermal Erbium: YAG laser trabecular ablation. In 20 anaesthetized rabbits gonioscopically controlled ab-interno photoablation of the ligamenta pectinata and underlying trabecular meshwork (TM) was performed with a single-pulsed (200 microseconds) Erbium: YAG (2.94 microns) laser. The right eye received 12-15 single laser pulses (2 mJ) delivered through an articulated zirconium fluoride fiberoptic and a 200 microns (core diameter) quartz fiber tip, the left unoperated eye served as control. At time intervals of 30 minutes, 2, 10, 30, and 60 days after laser treatment, eyes were processed for light- and scanning electron microscopy. The applied energy density of 6-4 J cm-2 resulted in visible dissection of the ligamenta pectinata and reproducible microperforations of the TM exposing scleral tissue accompanied by blood reflux from the aqueous plexus. The initial ablation zones measured 154 +/- 36 microns in depth and 45 +/- 6 microns in width. Collateral thermal damage zones were 22 +/- 8 microns. At two days post-operative, ablation craters were still blood- and fibrin-filled. The inner surface of the craters were covered with granulocytes. No cellular infiltration of the collateral thermal damage zone was observed. At 10 days post-operative, progressive fibroblastic proliferation was observed, resulting in dense scar tissue formation with anterior synechiae, proliferating capillaries and loss of intertrabecular spaces inside the range of former laser treatment at 60 days post-operative. Trabecular microperforations were closed 60 days after laser treatment in all rabbits. IOP in treated and contralateral eyes did not significantly change its level during whole period of observation. Low-thermal infrared laser energy with minimal thermal damage to collateral

  8. Bone apatite composition of necrotic trabecular bone in the femoral head of immature piglets.

    Science.gov (United States)

    Aruwajoye, Olumide O; Kim, Harry K W; Aswath, Pranesh B

    2015-04-01

    Ischemic osteonecrosis of the femoral head (IOFH) can lead to excessive resorption of the trabecular bone and collapse of the femoral head as a structure. A well-known mineral component to trabecular bone is hydroxyapatite, which can be present in many forms due to ionic substitution, thus altering chemical composition. Unfortunately, very little is known about the chemical changes to bone apatite following IOFH. We hypothesized that the apatite composition changes in necrotic bone possibly contribute to increased osteoclast resorption and structural collapse of the femoral head. The purpose of this study was to assess the macroscopic and local phosphate composition of actively resorbed necrotic trabecular bone to isolate differences between areas of increased osteoclast resorption and normal bone formation. A piglet model of IOFH was used. Scanning electron microscopy (SEM), histology, X-ray absorbance near edge structure (XANES), and Raman spectroscopy were performed on femoral heads to characterize normal and necrotic trabecular bone. Backscattered SEM, micro-computed tomography and histology showed deformity and active resorption of necrotic bone compared to normal. XANES and Raman spectroscopy obtained from actively resorbed necrotic bone and normal bone showed increased carbonate-to-phosphate content in the necrotic bone. The changes in the apatite composition due to carbonate substitution may play a role in the increased resorption of necrotic bone due to its increase in solubility. Indeed, a better understanding of the apatite composition of necrotic bone could shed light on osteoclast activity and potentially improve therapeutic treatments that target excessive resorption of bone.

  9. Bone mineral density and trabecular bone tissue quality in obese men

    Directory of Open Access Journals (Sweden)

    V.V. Povoroznyuk

    2017-02-01

    Full Text Available Obesity and osteoporosis are the two metabolic dise­ases with increased prevalence over last decades and a strong impact on the global morbidity and mortality have gained a status of major health threats worldwide. There is evidence that the higher body mass index (BMI values are associated with greater bone mineral density (BMD resulting in a site-specific protective effect for fragility fractures. On the other hand, higher BMI values increases incidence of falls and is associated with worse fractures consolidation. However, trabecular bone score (TBS indirectly explores bone quali­ty, independently of BMD. The aim of the study was to determine the connection between the BMD and TBS parameters in Ukrainian men suffering from obesity. Methods. We examined 396 men aged 40–89 years, by the BMI all the subjects were divided into 2 groups: Group A — with obesity and BMI ≥ 30 kg/m2 (n = 129 and Group B — without obesity and BMI < 30 kg/m2 (n = 267. The BMD of total body, lumbar spine at the site L1–L4, femur and forearm were measured by DXA (Prodigy, GEHC Lunar, Madison, WI, USA. The TBS of L1–L4 was assessed by means of TBS iNsight (Med-Imaps, Pessac, France. Results. In general, obese men had a significantly higher BMD of lumbar spine, femoral neck, total body and ultradistal forearm (p < 0.001 in comparison with men without obesity. The TBS of L1–L4 was significantly lower in obese men compared to non-obese men (p < 0.001. The significant positive correlation between the fat mass and the BMD at different sites was observed. The correlation between the fat mass and TBS of L1–L4 was also significant, but negative. Conclusions. Obesity negatively affects the quality of trabecular bone, while bone mineral density was significantly higher.

  10. Grizzly bears (Ursus arctos horribilis) and black bears (Ursus americanus) prevent trabecular bone loss during disuse (hibernation).

    Science.gov (United States)

    McGee-Lawrence, Meghan E; Wojda, Samantha J; Barlow, Lindsay N; Drummer, Thomas D; Castillo, Alesha B; Kennedy, Oran; Condon, Keith W; Auger, Janene; Black, Hal L; Nelson, O Lynne; Robbins, Charles T; Donahue, Seth W

    2009-12-01

    Disuse typically causes an imbalance in bone formation and bone resorption, leading to losses of cortical and trabecular bone. In contrast, bears maintain balanced intracortical remodeling and prevent cortical bone loss during disuse (hibernation). Trabecular bone, however, is more detrimentally affected than cortical bone in other animal models of disuse. Here we investigated the effects of hibernation on bone remodeling, architectural properties, and mineral density of grizzly bear (Ursus arctos horribilis) and black bear (Ursus americanus) trabecular bone in several skeletal locations. There were no differences in bone volume fraction or tissue mineral density between hibernating and active bears or between pre- and post-hibernation bears in the ilium, distal femur, or calcaneus. Though indices of cellular activity level (mineral apposition rate, osteoid thickness) decreased, trabecular bone resorption and formation indices remained balanced in hibernating grizzly bears. These data suggest that bears prevent bone loss during disuse by maintaining a balance between bone formation and bone resorption, which consequently preserves bone structure and strength. Further investigation of bone metabolism in hibernating bears may lead to the translation of mechanisms preventing disuse-induced bone loss in bears into novel treatments for osteoporosis.

  11. Contribution of the endosteal surface of cortical bone to the trabecular pattern seen on IOPA radiographs: an in vitro study

    Directory of Open Access Journals (Sweden)

    P T Ravikumar

    2012-01-01

    Full Text Available Objectives: A study was conducted to assess the contribution of the cancellous and endosteal surface of the cortical bone to the trabecular pattern seen in an IOPA radiograph. Materials and methods: An in vitro study analyzing the contribution of the endosteal surface of cortical bone and cancellous bone to the trabecular pattern was conducted, using 60 specimens of desiccated human mandibles. The mode of execution involved IOPA radiographic evaluation of premolarmolar segments in the specimens before and after removal of cancellous bone. The radiographs were numbered for identification and subjected to evaluation by 5 dentomaxillofacial radiologists who were doubleblinded to ensure an unbiased interpretation. Results: The trabecular pattern appreciation by the experts in the IOPA radiographs before and after removal of cancellous bone displayed immaculate correlation as per the Goodman-Kruskal Gamma Coefficient values which was 0.78 indicating a very large correlation. The relative density of trabecular pattern was significantly higher in radiograph before than after removal of cancellous bone with p-value less than 0.05. Conclusion: Based on these results it was adjudged that both the cancellous and endosteal surface of cortical bone contributed significantly to the trabecular pattern in an IOPA radiograph.

  12. The pattern of trabecular bone microarchitecture in the distal femur of typically developing children and its effect on processing of magnetic resonance images.

    Science.gov (United States)

    Modlesky, Christopher M; Whitney, Daniel G; Carter, Patrick T; Allerton, Brianne M; Kirby, Joshua T; Miller, Freeman

    2014-03-01

    Magnetic resonance imaging (MRI) is used to assess trabecular bone microarchitecture in humans; however, image processing can be labor intensive and time consuming. One aim of this study was to determine the pattern of trabecular bone microarchitecture in the distal femur of typically developing children. A second aim was to determine the proportion and location of magnetic resonance images that need to be processed to yield representative estimates of trabecular bone microarchitecture. Twenty-six high resolution magnetic resonance images were collected immediately above the growth plate in the distal femur of 6-12year-old typically developing children (n=40). Measures of trabecular bone microarchitecture [i.e., apparent trabecular bone volume to total volume (appBV/TV), trabecular number (appTb.N), trabecular thickness (appTb.Th) and trabecular separation (appTb.Sp)] in the lateral aspect of the distal femur were determined using the twenty most central images (20IM). The average values for appBV/TV, appTb.N, appTb.Th and appTb.Sp from 20IM were compared to the average values from 10 images (10IM), 5 images (5IM) and 3 images (3IM) equally dispersed throughout the total image set and one image (1IM) from the center of the total image set using linear regression analysis. The resulting mathematical models were cross-validated using the leave-one-out technique. Distance from the growth plate was strongly and inversely related to appBV/TV (r(2)=0.68, p0.05). However, there was a progressive decrease in the strength of the relationships as a smaller proportion of images were used to predict estimates from 20IM (r(2)=0.98 to 0.99 using 10IM, 0.94 to 0.96 using 5IM, 0.87 to 0.90 using 3IM and 0.66 to 0.72 using 1IM; all pimage sets agreed extremely well with estimates from 20IM. The findings indicate that partial magnetic resonance image sets can be used to provide reasonable estimates of trabecular bone microarchitecture status in the distal femur of typically

  13. Massage therapy during early postnatal life promotes greater lean mass and bone growth, mineralization, and strength in juvenile and young adult rats.

    Science.gov (United States)

    Chen, H; Miller, S; Shaw, J; Moyer-Mileur, L

    2009-01-01

    The objects of this study were to investigate the effects of massage therapy during early life on postnatal growth, body composition, and skeletal development in juvenile and young adult rats. Massage therapy was performed for 10 minutes daily from D6 to D10 of postnatal life in rat pups (MT, n=24). Body composition, bone area, mineral content, and bone mineral density were measured by dual energy X-ray absorptiometry (DXA); bone strength and intrinsic stiffness on femur shaft were tested by three-point bending; cortical and cancellous bone histomorphometric measurements were performed at D21 and D60. Results were compared to age- and gender-matched controls (C, n=24). D21 body weight, body length, lean mass, and bone area were significantly greater in the MT cohort. Greater bone mineral content was found in male MT rats; bone strength and intrinsic stiffness were greater in D60 MT groups. At D60 MT treatment promoted bone mineralization by increasing trabecular mineral apposition rate in male and endosteal mineral surface in females, and also improved micro-architecture by greater trabeculae width in males and decreasing trabecular separation in females. In summary, massage therapy during early life elicited immediate and prolonged anabolic effects on postnatal growth, lean mass and skeletal developmental in a gender-specific manner in juvenile and young adult rats.

  14. Adaptations in the Microarchitecture and Load Distribution of Maternal Cortical and Trabecular Bone in Response to Multiple Reproductive Cycles in Rats

    Science.gov (United States)

    de Bakker, Chantal M. J.; Altman-Singles, Allison R.; Li, Yihan; Tseng, Wei-Ju; Li, Connie; Liu, X. Sherry

    2017-01-01

    Pregnancy, lactation, and weaning result in dramatic changes in maternal calcium metabolism. In particular, the increased calcium demand during lactation causes a substantial degree of maternal bone loss. This reproductive bone loss has been suggested to be largely reversible, as multiple clinical studies have found that parity and lactation history have no adverse effect on post-menopausal fracture risk. However, the precise effects of pregnancy, lactation, and post-weaning recovery on maternal bone structure are not well understood. Our study aimed to address this question by longitudinally tracking changes in trabecular and cortical bone microarchitecture at the proximal tibia in rats throughout three cycles of pregnancy, lactation, and post-weaning using in vivo μCT. We found that the trabecular thickness underwent a reversible deterioration during pregnancy and lactation, which was fully recovered after weaning, while other parameters of trabecular microarchitecture (including trabecular number, spacing, connectivity density, and structure model index) underwent a more permanent deterioration which recovered minimally. Thus, pregnancy and lactation resulted in both transient and long-lasting alterations in trabecular microstructure. In the meantime, multiple reproductive cycles appeared to improve the robustness of cortical bone (resulting in an elevated cortical area and polar moment of inertia), as well as increase the proportion of the total load carried by the cortical bone at the proximal tibia. Taken together, changes in the cortical and trabecular compartments suggest that while rat tibial trabecular bone appears to be highly involved in maintaining calcium homeostasis during female reproduction, cortical bone adapts to increase its load-bearing capacity, allowing the overall mechanical function of the tibia to be maintained. PMID:28109138

  15. Quantification of age-related changes in the structure model type and trabecular thickness of human tibial cancellous

    DEFF Research Database (Denmark)

    Ding, Ming; Hvid, I

    2000-01-01

    Structure model type and trabecular thickness are important characteristics in describing cancellous bone architecture. It has been qualitatively observed that a radical change of trabeculae from plate-like to rod-like occurs in aging, bone remodeling, and osteoporosis. Thickness of trabeculae has...... traditionally been measured using model-based histomorphometric methods on two-dimensional (2-D) sections. However, no quantitative study has been published based on three-dimensional (3-D) methods on the age-related changes in structure model type and trabecular thickness for human peripheral (tibial......, structure model type and trabecular thickness were quantified by means of novel 3-D methods. Structure model type was assessed by calculating the structure model index (SMI). The SMI was quantified based on a differential analysis of the triangulated bone surface of a structure. This technique allows...

  16. A theoretical framework for strain-related trabecular bone maintenance and adaptation

    NARCIS (Netherlands)

    Ruimerman, R.; Hilbers, P.A.J.; Rietbergen, van B.; Huiskes, R.

    2005-01-01

    It is assumed that density and morphology of trabecular bone is partially controlled by mechanical forces. How these effects are expressed in the local metabolic functions of osteoclast resorption and osteoblast formation is not known. In order to investigate possible mechano-biological pathways for

  17. Relationships between age and microarchitectural descriptors of iliac trabecular bone determined by microCT.

    Science.gov (United States)

    Deguette, C; Ramond-Roquin, A; Rougé-Maillart, C

    2017-06-01

    Estimation of age at death is a major issue in anthropology. The main anthropological histological methods propose studying the architecture of cortical bone. In bone histomorphometry, researches on metabolic bone diseases have provided normative tables for trabecular bone volume (BV/TV) according to age and gender of individuals on trans-iliac bone biopsies. We have used microCT, a non-destructive tool for measuring bone volume and trabecular descriptors to compare the French tables to a series of forensic anthropological population and if the two iliac bones could be used interchangeably. Coxal bone of a personal forensic collection whose age and gender were known (DNA identification) were used. Bone samples, centered on the same area than bone biopsy. MicroCT (pixel size: 36μm) was used to measure BV/TV and morphometric trabecular parameters of microarchitecture. An adjusted Z-score was calculated for BV/TV to compare with normative tables and a right/left comparison of trabecular parameters was provided. Twenty-seven iliac bones, which 20 forming 10 complete pelvises, aged between 24 and 73y.o. (average of 47.7 y.o.) were used. All adjusted Z-score were within normal values. There was a strong positive correlation between right and left sides for Tb.Th, Tb.N and Tb.Sp, but an insignificant correlation was obtained for BV/TV. Normative tables between age and BV/TV are valid and therefore usable in anthropology. They may represent an alternative to determine the age at death. Nevertheless, it requires a precise technique that could be a drawback in current practice. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  18. Computed tomographic analysis of tibiotarsal bone mineral density and content in turkeys as influenced by age and sex

    International Nuclear Information System (INIS)

    Charuta, A.; Cooper, R.G.; Pierzchala, M.; Horbanczuk, J.O.

    2012-01-01

    Changes in the volumetric bone mineral density (vBMD) and bone mineral content (BMC) of tibiotarsal bones of growing turkeys as affected by birds' age, sex, and within-the-bone location, respectively, were determined by computed tomography. The research was performed on 165 heavy-type BIG 6 turkeys reared between weeks (wk) 3-16 of age. The computed tomography measurement, conducted at 18 and 50% of the bone length, comprised a bone fragment which was 0.07 mm thick for the compact and the spongious substance collectively. It should be noted that the diaphyses of the tibiotarsal bones in turkeys (580 mg/cubic cm) had significantly greater vBMD than the proximal metaphyses (300 mg/cubic cm). BMC was higher in metaphyses for both sexes. Significant differences between the BMC of the metaphyses and the diaphyses were observed in males and females at wk 3, 6 and 9, and at wk 3 and 12, respectively. vBMD in the diaphyses gradually attenuated with age for both sexes, from 688 mg/cubic cm (wk 3) to 532 mg/cubic cm (wk 16). vBMD of the metaphyses was constant in females, but in males it achieved maximum values of 350 mg/cubic cm at wk 6 and 12 and minimum of 260 mg/cubic cm at wk 9 and 16. Correlations between body weight and vBMD of the diaphyses were observed in males (r = -0.85, P less than 0.001) and females (r = -0.52, P less than 0.01). It can be concluded that vBMD loss in diaphyses diminished bone-breaking strength leading in investigated turkeys to deformities and bone fractures

  19. Trabecular evidence for a human-like gait in Australopithecus africanus.

    Directory of Open Access Journals (Sweden)

    Meir M Barak

    Full Text Available Although the earliest known hominins were apparently upright bipeds, there has been mixed evidence whether particular species of hominins including those in the genus Australopithecus walked with relatively extended hips, knees and ankles like modern humans, or with more flexed lower limb joints like apes when bipedal. Here we demonstrate in chimpanzees and humans a highly predictable and sensitive relationship between the orientation of the ankle joint during loading and the principal orientation of trabecular bone struts in the distal tibia that function to withstand compressive forces within the joint. Analyses of the orientation of these struts using microCT scans in a sample of fossil tibiae from the site of Sterkfontein, of which two are assigned to Australopithecus africanus, indicate that these hominins primarily loaded their ankles in a relatively extended posture like modern humans and unlike chimpanzees. In other respects, however, trabecular properties in Au africanus are distinctive, with values that mostly fall between those of chimpanzees and humans. These results indicate that Au. africanus, like Homo, walked with an efficient, extended lower limb.

  20. Comparative Analysis of Bone Structural Parameters Reveals Subchondral Cortical Plate Resorption and Increased Trabecular Bone Remodeling in Human Facet Joint Osteoarthritis

    Directory of Open Access Journals (Sweden)

    Cordula Netzer

    2018-03-01

    Full Text Available Facet joint osteoarthritis is a prominent feature of degenerative spine disorders, highly prevalent in ageing populations, and considered a major cause for chronic lower back pain. Since there is no targeted pharmacological therapy, clinical management of disease includes analgesic or surgical treatment. The specific cellular, molecular, and structural changes underpinning facet joint osteoarthritis remain largely elusive. The aim of this study was to determine osteoarthritis-related structural alterations in cortical and trabecular subchondral bone compartments. To this end, we conducted comparative micro computed tomography analysis in healthy (n = 15 and osteoarthritic (n = 22 lumbar facet joints. In osteoarthritic joints, subchondral cortical plate thickness and porosity were significantly reduced. The trabecular compartment displayed a 42 percent increase in bone volume fraction due to an increase in trabecular number, but not trabecular thickness. Bone structural alterations were associated with radiological osteoarthritis severity, mildly age-dependent but not gender-dependent. There was a lack of association between structural parameters of cortical and trabecular compartments in healthy and osteoarthritic specimens. The specific structural alterations suggest elevated subchondral bone resorption and turnover as a potential treatment target in facet joint osteoarthritis.

  1. Development of a mechanical testing and loading system for trabecular bone studies for long term culture

    Directory of Open Access Journals (Sweden)

    DB Jones

    2003-03-01

    Full Text Available A highly accurate (�3% mechanical loading and measurement system combined with a trabecular bone diffusion culture-loading chamber has been developed, which provides the ability to study trabecular bone (and possibly cartilage under controlled culture and loading conditions over long periods of time. The loading device has been designed to work in two main modes, either to apply a specific compressive strain to a trabecular bone cylinder or to apply a specific force and measure the resulting deformation. Presently, precisely machined bone cylinders can be loaded at frequencies between 0.1 Hz to 50 Hz and amplitudes over 7,000�e. The system allows accurate measurement of many mechanical properties of the tissue in real time, including visco-elastic properties. This paper describes the technical components, reproducibility, precision, and the calibration procedures of the loading system. Data on long term culture and mechanical responses to different loading patterns will be published separately.

  2. Revision total knee arthroplasty with the use of trabecular metal cones

    DEFF Research Database (Denmark)

    Jensen, Claus L; Petersen, Michael Mygind; Schrøder, Henrik

    2012-01-01

    "Trabecular Metal Cone" (TM Cone) (Zimmer, Inc, Warsaw, Ind) for reconstruction of bone loss in the proximal tibia during revision total knee arthroplasty is now optional. Forty patients were randomized to receive revision total knee arthroplasty with or without TM Cone (No TM Cone). The Anderson...

  3. Age-related changes of vertical and horizontal lumbar vertebral trabecular 3D bone microstructure is different in women and men.

    Science.gov (United States)

    Thomsen, Jesper Skovhus; Niklassen, Andreas Steenholt; Ebbesen, Ebbe Nils; Brüel, Annemarie

    2013-11-01

    The study presents a 3D method for subdividing a trabecular network into horizontal and vertical oriented bone. This method was used to investigate the age related changes of the bone volume fraction and thickness of horizontal and vertical trabeculae in human lumbar vertebral bone estimated with unbiased 3D methods in women and men over a large age-range. The study comprised second lumbar vertebral body bone samples from 40 women (aged 21.7-96.4years, median 56.6years) and 39 men (aged 22.6-94.6years, median 55.6years). The bone samples were μCT scanned and the 3D microstructure was quantified. A voxel based algorithm inspecting the local neighborhood is presented and used to segment the trabecular network into horizontal and vertical oriented bone. For both women and men BV/TV decreased significantly with age, Tb.Th* was independent of age, while SMI increased significantly with age. Vertical (BV.vert/TV) and horizontal (BV.horz/TV) bone volume fraction decreased significantly with age for both sexes. BV.vert/TV decreased significantly faster with age for women than for men. Vertical (Tb.Th*.vert) and horizontal (Tb.Th*.horz) trabecular thickness were independent of age, while Tb.Th*.horz/Tb.Th*.vert decreased significantly with age for both sexes. Additionally, the 95th percentile of the trabecular thickness distribution increased significantly with age for vertical trabeculae in women, whereas it was independent of age in men. In conclusion, we have shown that vertical and horizontal oriented bone density decreases with age in both women and men, and that vertical oriented bone is lost more quickly in women than in men. Furthermore, vertical and horizontal trabecular thickness were independent of age, whereas the horizontal to vertical trabecular thickness ratio decreased significantly with age indicating a relatively more pronounced thinning of horizontal trabeculae. Finally, the age-related loss of trabecular elements appeared to result in a compensatory

  4. Comparison of different plasticity criteria for trabecular bone failure modelling

    Czech Academy of Sciences Publication Activity Database

    Jiroušek, Ondřej

    2008-01-01

    Roč. 8, č. 1 (2008), s. 10177-10178 ISSN 1617-7061. [Annual Meeting of International Association of Applied Mathematics and Mechanics. Bremen, 31.03.2008-04.04.2008] R&D Projects: GA ČR(CZ) GA103/05/1020 Institutional research plan: CEZ:AV0Z20710524 Keywords : nanoindentation * plasticity criteria * trabecular bone Subject RIV: FI - Traumatology, Orthopedics

  5. Trabecular bone structure and strength - remodelling and repair

    DEFF Research Database (Denmark)

    Mosekilde, Lis; Ebbesen, Ebbe Nils; Erikstrup, Lise Tornvig

    2000-01-01

    vertical and horizontal struts reaching a certain magnitude and thereby inducing buckling under compression. 4) Microdamage and microfractures will occur - mainly in these very loaded vertical struts. The microfractures will be repaired by microcallus formation, and these calluses will later be removed...... can never be isolated in vivo, other factors need to be investigated: The interplay between the cortical shell and the trabecular network; transmission of load; the interplay between soft tissues (cartilage, connective tissue, muscle) and bone; the shock absorbing capacity of the discs...

  6. Neocellularization and neovascularization of nanosized bioactive glass-coated decellularized trabecular bone scaffolds

    KAUST Repository

    Gerhardt, Lutz Christian; Widdows, Kate L.; Erol, Melek M.; Nandakumar, Anandkumar; Roqan, Iman S.; Ansari, Tahera I.; Boccaccini, Aldo R.

    2012-01-01

    amount of vascular endothelial growth factor (VEGF) secreted by human fibroblasts grown on n-BG coatings (0-1.245 mg/cm 2), decellularized trabecular bone samples (porosity: 43-81%) were coated with n-BG particles. Grown on n-BG particles at a coating

  7. Direct mechanics assessment of elastic symmetries and properties of trabecular bone architecture

    NARCIS (Netherlands)

    Rietbergen, van B.; Odgaard, A.; Kabel, J.; Huiskes, H.W.J.

    1996-01-01

    A method is presented to find orthotropic elastic symmetries and constants directly from the elastic coefficients in the overall stiffness matrix of trabecular bone test specimens. Contrary to earlier developed techniques, this method does not require pure orthotropic behavior or additional fabric

  8. Multi-axial fatigue of trabecular bone with respect to normal walking

    CERN Document Server

    Mostakhdemin, Mohammad; Syahrom, Ardiyansyah

    2016-01-01

    This book focuses on the analysis and treatment of osteoporotic bone based on drug administration, tracking fatigue behavior and taking into consideration the mechanical interaction of implants with trabecular bone. Weak trabeculae are one of the most important clinical features that need to be addressed in order to prevent hip joint fractures.

  9. Relationship between tissue stiffness and degree of mineralization of developing trabecular bone

    NARCIS (Netherlands)

    Mulder, L.; Koolstra, J.H.; den Toonder, J.M.J.; van Eijden, T.M.G.J.

    2008-01-01

    It is unknown how the degree of mineralization of bone in individual trabecular elements is related to the corresponding mechanical properties at the bone tissue level. Understanding this relationship is important for the comprehension of the mechanical behavior of bone at both the apparent and

  10. Bisphosphonate treatment affects trabecular bone apparent modulus through micro-architecture rather than matrix properties

    DEFF Research Database (Denmark)

    Ding, Ming

    2004-01-01

    and trabecular architecture independently. Conventional histomorphometry and microdamage data were obtained from the second and third lumbar vertebrae of the same dogs [Bone 28 (2001) 524]. Bisphosphonate treatment resulted in an increased apparent Young's modulus, decreased bone turnover, increased calcified...... matrix density, and increased microdamage. We could not detect any change in the effective Young's modulus of the calcified matrix in the bisphosphonate treated groups. The observed increase in apparent Young's modulus was due to increased bone mass and altered trabecular architecture rather than changes...... in the calcified matrix modulus. We hypothesize that the expected increase in the Young's modulus of the calcified matrix due to the increased calcified matrix density was counteracted by the accumulation of microdamage. Udgivelsesdato: 2004 May...

  11. Characterization of synthetic foam structures used to manufacture artificial vertebral trabecular bone.

    Science.gov (United States)

    Fürst, David; Senck, Sascha; Hollensteiner, Marianne; Esterer, Benjamin; Augat, Peter; Eckstein, Felix; Schrempf, Andreas

    2017-07-01

    Artificial materials reflecting the mechanical properties of human bone are essential for valid and reliable implant testing and design. They also are of great benefit for realistic simulation of surgical procedures. The objective of this study was therefore to characterize two groups of self-developed synthetic foam structures by static compressive testing and by microcomputed tomography. Two mineral fillers and varying amounts of a blowing agent were used to create different expansion behavior of the synthetic open-cell foams. The resulting compressive and morphometric properties thus differed within and also slightly between both groups. Apart from the structural anisotropy, the compressive and morphometric properties of the synthetic foam materials were shown to mirror the respective characteristics of human vertebral trabecular bone in good approximation. In conclusion, the artificial materials created can be used to manufacture valid synthetic bones for surgical training. Further, they provide novel possibilities for studying the relationship between trabecular bone microstructure and biomechanical properties. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. [Reproducibility and accuracy in the morphometric and mechanical quantification of trabecular bone from 3 Tesla magnetic resonance images].

    Science.gov (United States)

    Alberich-Bayarri, A; Martí-Bonmatí, L; Sanz-Requena, R; Sánchez-González, J; Hervás Briz, V; García-Martí, G; Pérez, M Á

    2014-01-01

    We used an animal model to analyze the reproducibility and accuracy of certain biomarkers of bone image quality in comparison to a gold standard of computed microtomography (μCT). We used magnetic resonance (MR) imaging and μCT to study the metaphyses of 5 sheep tibiae. The MR images (3 Teslas) were acquired with a T1-weighted gradient echo sequence and an isotropic spatial resolution of 180μm. The μCT images were acquired using a scanner with a spatial resolution of 7.5μm isotropic voxels. In the preparation of the images, we applied equalization, interpolation, and thresholding algorithms. In the quantitative analysis, we calculated the percentage of bone volume (BV/TV), the trabecular thickness (Tb.Th), the trabecular separation (Tb.Sp), the trabecular index (Tb.N), the 2D fractal dimension (D(2D)), the 3D fractal dimension (D(3D)), and the elastic module in the three spatial directions (Ex, Ey and Ez). The morphometric and mechanical quantification of trabecular bone by MR was very reproducible, with percentages of variation below 9% for all the parameters. Its accuracy compared to the gold standard (μCT) was high, with errors less than 15% for BV/TV, D(2D), D(3D), and E(app)x, E(app)y and E(app)z. Our experimental results in animals confirm that the parameters of BV/TV, D(2D), D(3D), and E(app)x, E(app)y and E(app)z obtained by MR have excellent reproducibility and accuracy and can be used as imaging biomarkers for the quality of trabecular bone. Copyright © 2013 SERAM. Published by Elsevier Espana. All rights reserved.

  13. Marked disparity between trabecular and cortical bone loss with age in healthy men. Measurement by vertebral computed tomography and radial photon absorptiometry

    International Nuclear Information System (INIS)

    Meier, D.E.; Orwoll, E.S.; Jones, J.M.

    1984-01-01

    To define age-related changes in bone mineral content in normal men, we measured radial (proximal and distal) and vertebral bone mineral content in 62 men aged 30 to 92 years. Radial bone mineral content (largely cortical bone) was measured by single photon absorptiometry, and trabecular vertebral content (T12, L1 to L3) by computed tomography. Radial bone mineral content fell gradually (2% to 3.4% per decade) with age, but vertebral trabecular content fell more rapidly (12% per decade). Body size was not associated with the rate of bone loss from the distal radial and vertebral sites, but men with lower surface areas lost bone more rapidly at the predominantly cortical proximal radial site. The fact that radial cortical bone mineral content falls much less rapidly than vertebral trabecular content with age and is also associated with surface area indicates that trabecular and cortical bone compartments may be independently modulated. Age-related bone loss should not be considered a homogeneous process

  14. Prediction of progression of radiographic knee osteoarthritis using tibial trabecular bone texture

    DEFF Research Database (Denmark)

    Woloszynski, T; Podsiadlo, P; Stachowiak, G W

    2012-01-01

    OBJECTIVE.: To develop a system for prediction of progression of radiographic knee osteoarthritis (OA) using tibial trabecular bone (TB) texture. METHODS.: We studied 203 knees with (n=68) or without (n=135) radiographic tibiofemoral OA in 105 subjects (90 men, 15 women, mean age 54 years) who ha...

  15. Decreased trabecular bone biomechanical competence, apparent density, IGF-II and IGFBP-5 content in acromegaly

    DEFF Research Database (Denmark)

    Ueland, Thor; Ebbesen, Ebbe Nils; Thomsen, Jesper Skovhus

    2002-01-01

    of these growth factors in relation to biomechanical properties in acromegaly. MATERIALS AND METHODS: Trabecular bone biomechanical competence (compression test), apparent density (peripheral quantitative computed tomography, pQCT), and bone matrix contents of calcium (HCl hydrolysis) and IGFs (guanidinium......-HCl extraction) were measured in iliac crest biopsies from 13 patients with active acromegaly (two women and 11 men, aged 21-61 years) and 21 age- and sex-matched controls (four women and 17 men, aged 23-64 years). RESULTS: Trabecular bone pQCT was reduced in acromegalic patients compared with controls (P = 0...... bone content of IGF-I, IGFBP-3, or osteocalcin. However, IGF-II and IGFBP-5 content was decreased (P acromegaly, supporting previous observations...

  16. Hyperfunctioning Solid/Trabecular Follicular Carcinoma of the Thyroid Gland

    OpenAIRE

    Luca Giovanella; Fabrizio Fasolini; Sergio Suriano; Luca Mazzucchelli

    2010-01-01

    A 68-year-old woman with solid/trabecular follicular thyroid carcinoma inside of an autonomously functioning thyroid nodule is described in this paper. The patient was referred to our clinic for swelling of the neck and an increased pulse rate. Ultrasonography showed a slightly hypoechoic nodule in the right lobe of the thyroid. Despite suppressed TSH levels, the 9 9 m T c -pertechnetate scan showed a hot area corresponding to the nodule with a suppressed uptake in the remaining thyroid tissu...

  17. Trabecular bone structural parameters evaluated using dental cone-beam computed tomography: cellular synthetic bones.

    Science.gov (United States)

    Ho, Jung-Ting; Wu, Jay; Huang, Heng-Li; Chen, Michael Y c; Fuh, Lih-Jyh; Hsu, Jui-Ting

    2013-11-09

    This study compared the adequacy of dental cone beam computed tomography (CBCT) and micro computed tomography (micro-CT) in evaluating the structural parameters of trabecular bones. The cellular synthetic bones in 4 density groups (Groups 1-4: 0.12, 0.16, 0.20, and 0.32 g/cm3) were used in this study. Each group comprised 8 experimental specimens that were approximately 1 cm3. Dental CBCT and micro-CT scans were conducted on each specimen to obtain independent measurements of the following 4 trabecular bone structural parameters: bone volume fraction (BV/TV), specific bone surface (BS/BV), trabecular thickness (Tb.Th.), and trabecular separation (Tb.Sp.). Wilcoxon signed ranks tests were used to compare the measurement variations between the dental CBCT and micro-CT scans. A Spearman analysis was conducted to calculate the correlation coefficients (r) of the dental CBCT and micro-CT measurements. Of the 4 groups, the BV/TV and Tb.Th. measured using dental CBCT were larger compared with those measured using micro-CT. By contrast, the BS/BV measured using dental CBCT was significantly less compared with those measured using micro-CT. Furthermore, in the low-density groups (Groups 1 and 2), the Tb.Sp. measured using dental CBCT was smaller compared with those measured using micro-CT. However, the Tb.Sp. measured using dental CBCT was slightly larger in the high-density groups (Groups 3 and 4) than it was in the low density groups. The correlation coefficients between the BV/TV, BS/BV, Tb.Th., and Tb.Sp. values measured using dental CBCT and micro-CT were 0.9296 (p < .001), 0.8061 (p < .001), 0.9390 (p < .001), and 0.9583 (p < .001), respectively. Although the dental CBCT and micro-CT approaches exhibited high correlations, the absolute values of BV/TV, BS/BV, Tb.Th., Tb.Sp. differed significantly between these measurements. Additional studies must be conducted to evaluate using dental CBCT in clinical practice.

  18. The relationship between dental implant stability and trabecular bone structure using cone-beam computed tomography

    Science.gov (United States)

    2016-01-01

    Purpose The objective of this study was to investigate the relationships between primary implant stability as measured by impact response frequency and the structural parameters of trabecular bone using cone-beam computed tomography(CBCT), excluding the effect of cortical bone thickness. Methods We measured the impact response of a dental implant placed into swine bone specimens composed of only trabecular bone without the cortical bone layer using an inductive sensor. The peak frequency of the impact response spectrum was determined as an implant stability criterion (SPF). The 3D microstructural parameters were calculated from CT images of the bone specimens obtained using both micro-CT and CBCT. Results SPF had significant positive correlations with trabecular bone structural parameters (BV/TV, BV, BS, BSD, Tb.Th, Tb.N, FD, and BS/BV) (Pmicro-CT and CBCT (Pimplant stability prediction by combining BV/TV and SMI in the stepwise forward regression analysis. Bone with high volume density and low surface density shows high implant stability. Well-connected thick bone with small marrow spaces also shows high implant stability. The combination of bone density and architectural parameters measured using CBCT can predict the implant stability more accurately than the density alone in clinical diagnoses. PMID:27127692

  19. Micro-CT characterization of human trabecular bone in osteogenesis imperfecta

    Science.gov (United States)

    Jameson, John; Albert, Carolyne; Smith, Peter; Molthen, Robert; Harris, Gerald

    2011-03-01

    Osteogenesis imperfecta (OI) is a genetic syndrome affecting collagen synthesis and assembly. Its symptoms vary widely but commonly include bone fragility, reduced stature, and bone deformity. Because of the small size and paucity of human specimens, there is a lack of biomechanical data for OI bone. Most literature has focused on histomorphometric analyses, which rely on assumptions to extrapolate 3-D properties. In this study, a micro-computed tomography (μCT) system was used to directly measure structural and mineral properties in pediatric OI bone collected during routine surgical procedures. Surface renderings suggested a poorly organized, plate-like orientation. Patients with a history of bone-augmenting drugs exhibited increased bone volume fraction (BV/TV), trabecular number (Tb.N), and connectivity density (Eu.Conn.D). The latter two parameters appeared to be related to OI severity. Structural results were consistently higher than those reported in a previous histomorphometric study, but these differences can be attributed to factors such as specimen collection site, drug therapy, and assumptions associated with histomorphometry. Mineral testing revealed strong correlations with several structural parameters, highlighting the importance of a dual approach in trabecular bone testing. This study reports some of the first quantitative μCT data of human OI bone, and it suggests compelling possibilities for the future of OI bone assessment.

  20. Characterizing trabecular bone structure for assessing vertebral fracture risk on volumetric quantitative computed tomography

    Science.gov (United States)

    Nagarajan, Mahesh B.; Checefsky, Walter A.; Abidin, Anas Z.; Tsai, Halley; Wang, Xixi; Hobbs, Susan K.; Bauer, Jan S.; Baum, Thomas; Wismüller, Axel

    2015-03-01

    While the proximal femur is preferred for measuring bone mineral density (BMD) in fracture risk estimation, the introduction of volumetric quantitative computed tomography has revealed stronger associations between BMD and spinal fracture status. In this study, we propose to capture properties of trabecular bone structure in spinal vertebrae with advanced second-order statistical features for purposes of fracture risk assessment. For this purpose, axial multi-detector CT (MDCT) images were acquired from 28 spinal vertebrae specimens using a whole-body 256-row CT scanner with a dedicated calibration phantom. A semi-automated method was used to annotate the trabecular compartment in the central vertebral slice with a circular region of interest (ROI) to exclude cortical bone; pixels within were converted to values indicative of BMD. Six second-order statistical features derived from gray-level co-occurrence matrices (GLCM) and the mean BMD within the ROI were then extracted and used in conjunction with a generalized radial basis functions (GRBF) neural network to predict the failure load of the specimens; true failure load was measured through biomechanical testing. Prediction performance was evaluated with a root-mean-square error (RMSE) metric. The best prediction performance was observed with GLCM feature `correlation' (RMSE = 1.02 ± 0.18), which significantly outperformed all other GLCM features (p biomechanical strength prediction in spinal vertebrae can be significantly improved through characterization of trabecular bone structure with GLCM-derived texture features.

  1. Tissue viscoelasticity is related to tissue composition but may not fully predict the apparent-level viscoelasticity in human trabecular bone – An experimental and finite element study

    DEFF Research Database (Denmark)

    Ojanen, X.; Tanska, P.; Malo, M. K.H.

    2017-01-01

    Trabecular bone is viscoelastic under dynamic loading. However, it is unclear how tissue viscoelasticity controls viscoelasticity at the apparent-level. In this study, viscoelasticity of cylindrical human trabecular bone samples (n = 11, male, age 18–78 years) from 11 proximal femurs were charact......). These findings indicate that bone tissue viscoelasticity is affected by tissue composition but may not fully predict the macroscale viscoelasticity in human trabecular bone....

  2. Ethnic differences in trabecular meshwork height by optical coherence tomography.

    Science.gov (United States)

    Chen, Rebecca I; Barbosa, Diego T; Hsu, Chi-Hsin; Porco, Travis C; Lin, Shan C

    2015-04-01

    Differences in ocular anatomy may contribute to ethnic differences in glaucoma risk. Because the trabecular meshwork (TM) plays an important role in aqueous outflow, its anatomy in relation to at-risk populations may provide insight into a potential contributor to elevated intraocular pressure and thus to probability of glaucoma development. To investigate whether differences exist in TM height between ethnic groups. This prospective study took place from January 1, 2012, to December 31, 2013. Adult patients who self-reported as being of white, Asian, Hispanic, or African American ethnicity were recruited from ophthalmology clinics at the University of California, San Francisco. The TM height was assessed using spectral-domain anterior segment optical coherence tomography. Trabecular meshwork height was measured from the scleral spur to the Schwalbe line. We hypothesized that ethnicities with a higher prevalence of glaucoma would tend to have shorter TM heights. We collected data from 460 eyes of 291 participants after excluding 34 optical coherence tomographic scans owing to poor image quality. The final sample was 32.2% white, 45.1% Asian, 10.5% African American, and 12.1% Hispanic. There were 64.2% women, and the mean age was 68.1 years. The mean (SD) TM height among all eyes included in the study was 836 (131) μm. The mean (SD) TM height was characterized among white (851 [131] μm), Asian (843 [126] μm), Hispanic (822 [147] μm), and African American (771 [118] μm) persons. Ethnicity was not associated with TM height overall (P = .23, linear mixed regression model). However, the TM heights of African American participants (771 μm) were shorter than those of white (851 μm; adjusted difference 95% CI, -119.8 to -8.1; P = .02) and Asian (843 μm; adjusted difference 95% CI, -117.4 to -10.8; P = .02) participants. Although TM height is not associated with ethnicity overall, African American individuals have shorter TM heights compared with Asian and white

  3. Fabrication of Trabecular Bone-Templated Tissue-Engineered Constructs by 3D Inkjet Printing.

    Science.gov (United States)

    Vanderburgh, Joseph P; Fernando, Shanik J; Merkel, Alyssa R; Sterling, Julie A; Guelcher, Scott A

    2017-11-01

    3D printing enables the creation of scaffolds with precisely controlled morphometric properties for multiple tissue types, including musculoskeletal tissues such as cartilage and bone. Computed tomography (CT) imaging has been combined with 3D printing to fabricate anatomically scaled patient-specific scaffolds for bone regeneration. However, anatomically scaled scaffolds typically lack sufficient resolution to recapitulate the 3D constructs are fabricated via a new micro-CT/3D inkjet printing process. It is shown that this process reproducibly fabricates bone-templated constructs that recapitulate the anatomic site-specific morphometric properties of trabecular bone. A significant correlation is observed between the structure model index (a morphometric parameter related to surface curvature) and the degree of mineralization of human mesenchymal stem cells, with more concave surfaces promoting more extensive osteoblast differentiation and mineralization compared to predominately convex surfaces. These findings highlight the significant effects of trabecular architecture on osteoblast function. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Automatic analysis of trabecular bone structure from knee MRI

    DEFF Research Database (Denmark)

    Marques, Joselene; Granlund, Rabia; Lillholm, Martin

    2012-01-01

    We investigated the feasibility of quantifying osteoarthritis (OA) by analysis of the trabecular bone structure in low-field knee MRI. Generic texture features were extracted from the images and subsequently selected by sequential floating forward selection (SFFS), following a fully automatic......, uncommitted machine-learning based framework. Six different classifiers were evaluated in cross-validation schemes and the results showed that the presence of OA can be quantified by a bone structure marker. The performance of the developed marker reached a generalization area-under-the-ROC (AUC) of 0...

  5. Trabecular metal acetabular components in primary total hip arthroplasty

    DEFF Research Database (Denmark)

    Laaksonen, Inari; Lorimer, Michelle; Gromov, Kirill

    2018-01-01

    Background and purpose - Trabecular metal (TM) cups have demonstrated favorable results in acetabular revision and their use in primary total hip arthroplasty (THA) is increasing. Some evidence show that TM cups might decrease periprosthetic infection (PPI) incidence. We compared the survivorship...... of TM cups with that of other uncemented cups in primary THA, and evaluated whether the use of TM cups is associated with a lower risk of PPI. Patients and methods - 10,113 primary THAs with TM cup and 85,596 THAs with other uncemented cups from 2 high-quality national arthroplasty registries were...

  6. The effect of an osteolytic tumor on the three-dimensional trabecular bone morphology in an animal model

    International Nuclear Information System (INIS)

    Kurth, A.A.; Mueller, R.

    2001-01-01

    Objective. To investigate the application of micro-computed tomography (μCT) for the assessment of density differences and deterioration of three-dimensional architecture of trabecular bone in an experimental rat model for tumor- induced osteolytic defects.Design and materials. Walker carcinosarcoma 256 malignant breast cancer cells (W256) were surgically implanted into the medullary canal of the left femur of 15 4-month-old rats. Twenty-eight days after surgery all animals were killed and both femora from each rat were harvested. A total of 30 specimens (left and right femur) were scanned in a desk-top μCT imaging system (μCT 20, Scanco Medical) to assess densitometric and architectural parameters. For each specimen a total of 200 micro-tomographic slices with a resolution of 30 μm in the distal metaphysis was taken. Bone mineral content (BMC) was analyzed for both cortical and trabecular bone (ctBMC), and for trabecular bone only (tBMC). Architectural indices (BV/TV, Tb.N, Tb.Th, Tb.Sp) according to standard definitions used in histomorphometry were calculated for trabecular bone.Results. The quantitative analysis of density parameters revealed significantly (P<0.001) lower values for ctBMC and tBMC in the tumor-bearing group (T) of 26% and 31%, respectively, compared with the contralateral control group. The quantitative analysis revealed significant (P<0.001) changes in the architectural parameters in the tumor-bearing bones compared with the contralateral control group: BV/TV was 30% lower, Tb.N and BS/TV decreased by 24% and 21%, respectively, Tb.Th. decreased by 10% and Tb.Sp. increased by 94%.Conclusions. This study demonstrates that μCT is able to provide three-dimensional parameters of bone mass and trabecular structure in an animal model for tumor-induced bone loss. Recent advances in therapeutic approaches for skeletal diseases such as osteoporosis and metastatic bone disease rely on an understanding of the effects of the agents on the mechanical

  7. Inhibition of hyaluronan synthesis reduces versican and fibronectin levels in trabecular meshwork cells.

    Directory of Open Access Journals (Sweden)

    Kate E Keller

    Full Text Available Hyaluronan (HA is a major component of the extracellular matrix (ECM and is synthesized by three HA synthases (HAS. Similarities between the HAS2 knockout mouse and the hdf mutant mouse, which has a mutation in the versican gene, suggest that HA and versican expression may be linked. In this study, the relationship between HA synthesis and levels of versican, fibronectin and several other ECM components in trabecular meshwork cells from the anterior segment of the eye was investigated. HA synthesis was inhibited using 4-methylumbelliferone (4MU, or reduced by RNAi silencing of each individual HAS gene. Quantitative RT-PCR and immunoblotting demonstrated a reduction in mRNA and protein levels of versican and fibronectin. Hyaluronidase treatment also reduced versican and fibronectin levels. These effects could not be reversed by addition of excess glucose or glucosamine or exogenous HA to the culture medium. CD44, tenascin C and fibrillin-1 mRNA levels were reduced by 4MU treatment, but SPARC and CSPG6 mRNA levels were unaffected. Immunostaining of trabecular meshwork tissue after exposure to 4MU showed an altered localization pattern of HA-binding protein, versican and fibronectin. Reduction of versican by RNAi silencing did not affect HA concentration as assessed by ELISA. Together, these data imply that HA concentration affects synthesis of certain ECM components. Since precise regulation of the trabecular meshwork ECM composition and organization is required to maintain the aqueous humor outflow resistance and intraocular pressure homeostasis in the eye, coordinated coupling of HA levels and several of its ECM binding partners should facilitate this process.

  8. Strain analysis of trabecular bone using time-resolved X-ray microtomography

    Czech Academy of Sciences Publication Activity Database

    Jiroušek, Ondřej; Zlámal, Petr; Kytýř, Daniel; Kroupa, M.

    2011-01-01

    Roč. 633, Suppl. 1 (2011), s. 148-151 ISSN 0168-9002. [International Workshop on Radiation Imaging Detectors /11./. Praha, 28.06.2009-02.07.2009] R&D Projects: GA ČR(CZ) GP103/07/P483 Institutional research plan: CEZ:AV0Z20710524 Keywords : trabecular bone * X-ray microtomography * strain analysis * intrinsic material properties Subject RIV: JB - Sensors, Measurment, Regulation Impact factor: 1.207, year: 2011

  9. A novel use of 3D printing model demonstrates the effects of deteriorated trabecular bone structure on bone stiffness and strength.

    Science.gov (United States)

    Barak, Meir Max; Black, Margaret Arielle

    2018-02-01

    Trabecular bone structure is crucial to normal mechanical behavior of bones. Studies have shown that osteoporosis negatively affects trabecular bone structure, mainly by reducing bone volume fraction (BV/TV) and thus increasing fracture risk. One major limitation in assessing and quantifying the effect of this structural deterioration is that no two trabecular structures are identical. Thus, when we compare a group of healthy bones against a different group of bones that experienced resorption (i.e. decreased BV/TV) we only discover an "average" mechanical effect. It is impossible to quantify the mechanical effect of individual structural deterioration for each sample, simply because we never have the same sample in both states (intact and deteriorated structure). 3D printing is a new technology that can assist in overcoming this issue. Here we report a preliminary study that compares a healthy 3D printed trabecular bone model with the same model after bone resorption was simulated. Since the deteriorated structural bone model is derived from the healthy one, it is possible to directly estimate (percentage wise) the decrease of tissue stiffness and strength as a result of bone resorption for this specific structure. Our results demonstrate that a relatively small decrease in BV/TV (about 8%) leads to a dramatic decrease in structural strength (24%) and structural stiffness (17%), (P printing is a novel and valuable tool for quantifying the effect of structural deterioration on the mechanical properties of trabecular bone. In the future, this approach may help us attain better personal fracture risk assessments by CT scanning, 3D printing and mechanically testing individual bone replicas from patients suffering excessive bone resorption. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Trabecular architecture of the manual elements reflects locomotor patterns in primates.

    Science.gov (United States)

    Matarazzo, Stacey A

    2015-01-01

    The morphology of trabecular bone has proven sensitive to loading patterns in the long bones and metacarpal heads of primates. It is expected that we should also see differences in the manual digits of primates that practice different methods of locomotion. Primate proximal and middle phalanges are load-bearing elements that are held in different postures and experience different mechanical strains during suspension, quadrupedalism, and knuckle walking. Micro CT scans of the middle phalanx, proximal phalanx and the metacarpal head of the third ray were used to examine the pattern of trabecular orientation in Pan, Gorilla, Pongo, Hylobates and Macaca. Several zones, i.e., the proximal ends of both phalanges and the metacarpal heads, were capable of distinguishing between knuckle-walking, quadrupedal, and suspensory primates. Orientation and shape seem to be the primary distinguishing factors but differences in bone volume, isotropy index, and degree of anisotropy were seen across included taxa. Suspensory primates show primarily proximodistal alignment in all zones, and quadrupeds more palmar-dorsal orientation in several zones. Knuckle walkers are characterized by having proximodistal alignment in the proximal ends of the phalanges and a palmar-dorsal alignment in the distal ends and metacarpal heads. These structural differences may be used to infer locmotor propensities of extinct primate taxa.

  11. Photochemical Targeting Of Phagocytic Trabecular Meshwork Cells Using Chlorin E6 Coupled Microspheres

    Science.gov (United States)

    Latina, M. A.; Kobsa, P. H.; Rakestraw, S. L.; Crean, E. A.; Hasan, T.; Yarmush, M. L.

    1989-03-01

    We have investigated a novel and efficient delivery system utilizing photosensitizer-coupled-latex microspheres to photochemically target and kill phagocytic trabecular meshwork (TM) cells. TM cells are the most actively phagocytic cells within the anterior chamber of the eye and are located within an optically accessible discrete band. This delivery system, along with the property of cell photocytosis, will achieve double selectivity by combining preferential localization of the photosensitizer to the target cells with spatial localization of illumination on the target cells. All experiments were performed with preconfluent bovine TM cells, 3rd to 4th passage, plated in 15 mm wells. Chlorin e6 monoethylene diamine monoamide was conjugated to the surface of 1.0 Am MX Duke Scientific fluorescent latex microspheres. Spectroscopic analysis revealed an average of 1.3 x 10 -17 moles of chlorin e6 per microsphere. TM cells were incubated for 18 hours with 5 x 10 7 microspheres/ml in MEM with 10% FCS, washed with MEM, and irradiated through fresh media using an argon-pumped dye laser emitting .2 W at 660 nm. A dose-survival study indicated that energy doses of 10 J/cm2 or greater resulted in greater than 95% cell death as determined by ethidium bromide exclusion. Cell death could be demonstrated as early as 4 hours post-irradiation. TM cells incubated with a solution of chlorin e6 at a concentration equal to that conjugated to the microspheres showed no cell death. Unirradiated controls also showed no cell death.

  12. Assessing vertebral fracture risk on volumetric quantitative computed tomography by geometric characterization of trabecular bone structure

    Science.gov (United States)

    Checefsky, Walter A.; Abidin, Anas Z.; Nagarajan, Mahesh B.; Bauer, Jan S.; Baum, Thomas; Wismüller, Axel

    2016-03-01

    The current clinical standard for measuring Bone Mineral Density (BMD) is dual X-ray absorptiometry, however more recently BMD derived from volumetric quantitative computed tomography has been shown to demonstrate a high association with spinal fracture susceptibility. In this study, we propose a method of fracture risk assessment using structural properties of trabecular bone in spinal vertebrae. Experimental data was acquired via axial multi-detector CT (MDCT) from 12 spinal vertebrae specimens using a whole-body 256-row CT scanner with a dedicated calibration phantom. Common image processing methods were used to annotate the trabecular compartment in the vertebral slices creating a circular region of interest (ROI) that excluded cortical bone for each slice. The pixels inside the ROI were converted to values indicative of BMD. High dimensional geometrical features were derived using the scaling index method (SIM) at different radii and scaling factors (SF). The mean BMD values within the ROI were then extracted and used in conjunction with a support vector machine to predict the failure load of the specimens. Prediction performance was measured using the root-mean-square error (RMSE) metric and determined that SIM combined with mean BMD features (RMSE = 0.82 +/- 0.37) outperformed MDCT-measured mean BMD (RMSE = 1.11 +/- 0.33) (p biomechanical strength prediction in vertebrae can be significantly improved through the use of SIM-derived texture features from trabecular bone.

  13. Bone mineral density changes of lumbar spine and femur in osteoporotic patient treated with bisphosphonates and beta-hydroxy-beta-methylbutyrate (HMB): Case report.

    Science.gov (United States)

    Tatara, Marcin R; Krupski, Witold; Majer-Dziedzic, Barbara

    2017-10-01

    Currently available approaches to osteoporosis treatment include application of antiresorptive and anabolic agents influencing bone tissue metabolism. The aim of the study was to present bone mineral density (BMD) changes of lumbar spine in osteoporotic patient treated with bisphosphonates such as ibandronic acid and pamidronic acid, and beta-hydroxy-beta-methylbutyrate (HMB). BMD and volumetric BMD (vBMD) of lumbar spine were measured during the 6 year observation period with the use of dual-energy X-ray absorptiometry (DEXA) and quantitative computed tomography (QCT). The described case report of osteoporotic patient with family history of severe osteoporosis has shown site-dependent response of bone tissue to antiosteoporotic treatment with bisphosphonates. Twenty-five-month treatment with ibandronic acid improved proximal femur BMD with relatively poor effects on lumbar spine BMD. Over 15-month therapy with pamidronic acid was effective to improve lumbar spine BMD, while in the proximal femur the treatment was not effective. A total of 61-week long oral administration with calcium salt of HMB improved vBMD of lumbar spine in the trabecular and cortical bone compartments when monitored by QCT. Positive effects of nearly 2.5 year HMB treatment on BMD of lumbar spine and femur in the patient were also confirmed using DEXA method. The results obtained indicate that HMB may be applied for the effective treatment of osteoporosis in humans. Further studies on wider human population are recommended to evaluate mechanisms influencing bone tissue metabolism by HMB.

  14. Synergistic effect of parathyroid hormone and growth hormone on trabecular and cortical bone formation in hypophysectomized rats.

    Science.gov (United States)

    Guevarra, Maria Sarah N; Yeh, James K; Castro Magana, Mariano; Aloia, John F

    2010-01-01

    Growth hormone (GH) deficiency in pediatric patients results in short stature and osteopenia. We postulated that the GH and parathyroid hormone (PTH) combination would result in improvement in bone growth and bone formation. Forty hypophysectomized female rats at age 8 weeks were divided into hypophysectomy (HX), HX + PTH (62.5 microg/kg, s.c. daily), HX + GH (3.33 mg/kg, s.c. daily), and HX + PTH + GH for a 4-week study. GH increased body weight, bone growth, bone mineral content (BMC) and bone mineral density (BMD), whereas PTH increased BMC and BMD without a significant effect on bone size. GH increased both periosteal and endocortical bone formation and cortical size, while PTH increased only endocortical bone formation. GH mitigated the trabecular bone loss by increasing bone formation, while PTH increased bone mass by increasing bone formation and suppressing osteoclast number per bone area. The result of combined intervention shows an increase in trabecular, periosteal and endocortical bone formation and suppression of bone resorption resulting in a synergistic effect on increasing trabecular and cortical bone volume and BMD. The combination treatment of PTH and GH increases bone growth, bone formation, decreases bone resorption and has a synergistic effect on increasing bone density and bone mass. Copyright (c) 2010 S. Karger AG, Basel.

  15. A computer-aided system for automatic extraction of femur neck trabecular bone architecture using isotropic volume construction from clinical hip computed tomography images.

    Science.gov (United States)

    Vivekanandhan, Sapthagirivasan; Subramaniam, Janarthanam; Mariamichael, Anburajan

    2016-10-01

    Hip fractures due to osteoporosis are increasing progressively across the globe. It is also difficult for those fractured patients to undergo dual-energy X-ray absorptiometry scans due to its complicated protocol and its associated cost. The utilisation of computed tomography for the fracture treatment has become common in the clinical practice. It would be helpful for orthopaedic clinicians, if they could get some additional information related to bone strength for better treatment planning. The aim of our study was to develop an automated system to segment the femoral neck region, extract the cortical and trabecular bone parameters, and assess the bone strength using an isotropic volume construction from clinical computed tomography images. The right hip computed tomography and right femur dual-energy X-ray absorptiometry measurements were taken from 50 south-Indian females aged 30-80 years. Each computed tomography image volume was re-constructed to form isotropic volumes. An automated system by incorporating active contour models was used to segment the neck region. A minimum distance boundary method was applied to isolate the cortical and trabecular bone components. The trabecular bone was enhanced and segmented using trabecular enrichment approach. The cortical and trabecular bone features were extracted and statistically compared with dual-energy X-ray absorptiometry measured femur neck bone mineral density. The extracted bone measures demonstrated a significant correlation with neck bone mineral density (r > 0.7, p computed tomography images scanned with low dose could eventually be helpful in osteoporosis diagnosis and its treatment planning. © IMechE 2016.

  16. Troglitazone treatment increases bone marrow adipose tissue volume but does not affect trabecular bone volume in mice

    DEFF Research Database (Denmark)

    Erikstrup, Lise Tornvig; Mosekilde, Leif; Justesen, J

    2001-01-01

    proliferator activated receptor-gamma (PPARgamma). Histomorphometric analysis of proximal tibia was performed in order to quantitate the amount of trabecular bone volume per total volume (BV/TV %), adipose tissue volume per total volume (AV/TV %), and hematopoietic marrow volume per total volume (HV......Aging is associated with decreased trabecular bone mass and increased adipocyte formation in bone marrow. As osteoblasts and adipocytes share common precursor cells present in the bone marrow stroma, it has been proposed that an inverse relationship exists between adipocyte and osteoblast....../TV %) using the point-counting technique. Bone size did not differ between the two groups. In troglitazone-treated mice, AV/TV was significantly higher than in control mice (4.7+/-2.1% vs. 0.2+/-0.3%, respectively, mean +/- SD, P

  17. Serial analysis of gene expression (SAGE) in normal human trabecular meshwork.

    Science.gov (United States)

    Liu, Yutao; Munro, Drew; Layfield, David; Dellinger, Andrew; Walter, Jeffrey; Peterson, Katherine; Rickman, Catherine Bowes; Allingham, R Rand; Hauser, Michael A

    2011-04-08

    To identify the genes expressed in normal human trabecular meshwork tissue, a tissue critical to the pathogenesis of glaucoma. Total RNA was extracted from human trabecular meshwork (HTM) harvested from 3 different donors. Extracted RNA was used to synthesize individual SAGE (serial analysis of gene expression) libraries using the I-SAGE Long kit from Invitrogen. Libraries were analyzed using SAGE 2000 software to extract the 17 base pair sequence tags. The extracted sequence tags were mapped to the genome using SAGE Genie map. A total of 298,834 SAGE tags were identified from all HTM libraries (96,842, 88,126, and 113,866 tags, respectively). Collectively, there were 107,325 unique tags. There were 10,329 unique tags with a minimum of 2 counts from a single library. These tags were mapped to known unique Unigene clusters. Approximately 29% of the tags (orphan tags) did not map to a known Unigene cluster. Thirteen percent of the tags mapped to at least 2 Unigene clusters. Sequence tags from many glaucoma-related genes, including myocilin, optineurin, and WD repeat domain 36, were identified. This is the first time SAGE analysis has been used to characterize the gene expression profile in normal HTM. SAGE analysis provides an unbiased sampling of gene expression of the target tissue. These data will provide new and valuable information to improve understanding of the biology of human aqueous outflow.

  18. Vertebral body bone strength: the contribution of individual trabecular element morphology.

    Science.gov (United States)

    Parkinson, I H; Badiei, A; Stauber, M; Codrington, J; Müller, R; Fazzalari, N L

    2012-07-01

    Although the amount of bone explains the largest amount of variability in bone strength, there is still a significant proportion unaccounted for. The morphology of individual bone trabeculae explains a further proportion of the variability in bone strength and bone elements that contribute to bone strength depending on the direction of loading. Micro-CT imaging enables measurement of bone microarchitecture and subsequently mechanical strength of the same sample. It is possible using micro-CT data to perform morphometric analysis on individual rod and plate bone trabeculae using a volumetric spatial decomposition algorithm and hence determine their contribution to bone strength. Twelve pairs of vertebral bodies (T12/L1 or L4/L5) were harvested from human cadavers, and bone cubes (10 × 10 × 10 mm) were obtained. After micro-CT imaging, a volumetric spatial decomposition algorithm was applied, and measures of individual trabecular elements were obtained. Bone strength was measured in compression, where one bone specimen from each vertebral segment was tested supero-inferiorly (SI) and the paired specimen was tested antero-posteriorly (AP). Bone volume fraction was the strongest individual determinant of SI strength (r(2) = 0.77, p body bone architecture into its constituent morphological elements shows that trabecular element morphology has specific functional roles to assist in maintaining skeletal integrity.

  19. Histomorphometric Parameters of the Growth Plate and Trabecular Bone in Wild-Type and Trefoil Factor Family 3 (Tff3)-Deficient Mice Analyzed by Free and Open-Source Image Processing Software.

    Science.gov (United States)

    Bijelić, Nikola; Belovari, Tatjana; Stolnik, Dunja; Lovrić, Ivana; Baus Lončar, Mirela

    2017-08-01

    Trefoil factor family 3 (Tff3) peptide is present during intrauterine endochondral ossification in mice, and its deficiency affects cancellous bone quality in secondary ossification centers of mouse tibiae. The aim of this study was to quantitatively analyze parameters describing the growth plate and primary ossification centers in tibiae of 1-month-old wild-type and Tff3 knock-out mice (n=5 per genotype) by using free and open-source software. Digital photographs of the growth plates and trabecular bone were processed by open-source computer programs GIMP and FIJI. Histomorphometric parameters were calculated using measurements made with FIJI. Tff3 knock-out mice had significantly smaller trabecular number and significantly larger trabecular separation. Trabecular bone volume, trabecular bone surface, and trabecular thickness showed no significant difference between the two groups. Although such histomorphological differences were found in the cancellous bone structure, no significant differences were found in the epiphyseal plate histomorphology. Tff3 peptide probably has an effect on the formation and quality of the cancellous bone in the primary ossification centers, but not through disrupting the epiphyseal plate morphology. This work emphasizes the benefits of using free and open-source programs for morphological studies in life sciences.

  20. Validation of a measuring technique with computed tomography for cement penetration into trabecular bone underneath the tibial tray in total knee arthroplasty on a cadaver model

    International Nuclear Information System (INIS)

    Verburg, Hennie; Ridder, Laurens C van de; Verhoeven, Vincent WJ; Pilot, Peter

    2014-01-01

    In total knee arthroplasty (TKA), cement penetration between 3 and 5 mm beneath the tibial tray is required to prevent loosening of the tibia component. The objective of this study was to develop and validate a reliable in vivo measuring technique using CT imaging to assess cement distribution and penetration depth in the total area underneath a tibia prosthesis. We defined the radiodensity ranges for trabecular tibia bone, polymethylmethacrylate (PMMA) cement and cement-penetrated trabecular bone and measured the percentages of cement penetration at various depths after cementing two tibia prostheses onto redundant femoral heads. One prosthesis was subsequently removed to examine the influence of the metal tibia prostheses on the quality of the CT images. The percentages of cement penetration in the CT slices were compared with percentages measured with photographs of the corresponding transversal slices. Trabecular bone and cement-penetrated trabecular bone had no overlap in quantitative scale of radio-density. There was no significant difference in mean HU values when measuring with or without the tibia prosthesis. The percentages of measured cement-penetrated trabecular bone in the CT slices of the specimen were within the range of percentages that could be expected based on the measurements with the photographs (p = 0.04). CT scan images provide valid results in measuring the penetration and distribution of cement into trabecular bone underneath the tibia component of a TKA. Since the proposed method does not turn metal elements into artefacts, it enables clinicians to assess the width and density of the cement mantle in vivo and to compare the results of different cementing methods in TKA

  1. Copas de metal trabecular y aloinjertos óseos impactados en defectos acetabulares graves. Resultados a los 2-4 años. [Impacted bone allografts and trabecular metal cups in severe acetabular bone defects: 2 to 4-year results.

    Directory of Open Access Journals (Sweden)

    Martín Buttaro

    2014-06-01

    Full Text Available In­tro­duc­ción: El objetivo principal es presentar la supervivencia del componente acetabular en pacientes con defectos graves reconstruidos con copas de metal trabecular combinadas con aloinjertos óseos impactados. Como objetivo secundario, se compararon estos resultados con los previamente obtenidos por los autores en defectos de similar gravedad utilizando anillos de reconstrucción y aloinjertos óseos. Materiales­ y­ Métodos:­ Se realizaron 20 cirugías de revisión en 19 pacientes (edad promedio 65 años, controlados, de forma prospectiva, con defectos acetabulares graves tipos 3A o 3B de Paprosky, por falla mecánica o infecciosa. El puntaje funcional promedio preoperatorio fue de 6,2 puntos, según la escala de Merle D ́Aubigne. Siempre se utilizaron copas de metal trabecular y aloinjertos óseos impactados. Resultados:­ A los 30 meses de seguimiento promedio (rango 24-48 meses, la supervivencia del componente acetabular fue del 95% (IC = 75%-98%. Un paciente presentó un aflojamiento acetabular por infección profunda a las 16 semanas de la revisión y fue tratado con una artroplastia de resección. El puntaje funcional promedio, excluido el caso con aflojamiento posoperatorio, fue de 16,2 puntos. Se observó la incorporación de los aloinjertos óseos en todos los pacientes, salvo el caso con infección profunda. La comparación con nuestras series históricas reconstruidas con anillos de Kerboull o con anillos GAP arrojó resultados altamente favorables a favor de las copas de metal trabecular.  Conclusiones: Las copas de metal trabecular asociadas a aloinjertos óseos impactados ofrecen una alternativa válida en cirugía de revisión acetabular con defectos graves del capital óseo. Este método se asocia a resultados más favorables que los obtenidos antes con anillos de reconstrucción.

  2. Preliminary report of cells at risk at the bone surface in trabecular bone

    International Nuclear Information System (INIS)

    Jee, W.S.S.; Wronski, T.J.; Kimmel, D.B.; Dell, R.B.; Johnson, F.

    1975-01-01

    This is a report of some early work on the cells at risk portion of the dynamic microanatomical dosimetry program of the Bone Group. The cells lining the trabecular bone of thoracic vertebral bodies from beagles aged 568, 2942, 4117, 4277, 4629, and 4801 days were characterized. Histologic and sampling experience gained in this attempt indicates that further improvements are needed

  3. A study of trabecular bone strength and morphometric analysis of bone microstructure from digital radiographic image

    International Nuclear Information System (INIS)

    Han, Seung Yun; Lee, Sun Bok; Oh, Sung Ook; Heo, Min Suk; Lee, Sam Sun; Choi, Soon Chul; Park, Tae Won; Kim, Jong Dae

    2003-01-01

    To evaluate the relationship between morphometric analysis of microstructure from digital radiographic image and trabecular bone strength. One hundred eleven bone specimens with 5 mm thickness were obtained from the mandibles of 5 pigs. Digital images of specimens were taken using a direct digital intraoral radiographic system. After selection of ROI(100 x 100 pixel) within the trabecular bone, mean gray level and standard deviation were obtained. Fractal dimension and the variants of morphometric analysis (trabecular area, periphery, length of skeletonized trabeculae, number of terminal point, number of branch point) were obtained from ROI. Punch sheer strength analysis was performed using Instron (model 4465, Instron Corp., USA). The loading force (loading speed 1mm/min) was applied to ROI of bone specimen by a 2 mm diameter punch. Stress-deformation curve was obtained from the punch sheer strength analysis and maximum stress, yield stress, Young's modulus were measured. Maximum stress had a negative linear correlation with mean gray level and fractal dimension significantly (p<0.05). Yield stress had a negative linear correlation with mean gray level, periphery, fractal dimension and the length of skeletonized trabeculae significantly (p<0.05). Young's modulus had a negative linear correlation with mean gray level and fractal dimension significantly (p<0.05). The strength of cancellous bone exhibited a significantly linear relationship between mean gray level, fractal dimension and morphometric analysis. The methods described above can be easily used to evaluate bone quality clinically.

  4. Renin inhibitor aliskiren exerts beneficial effect on trabecular bone by regulating skeletal renin-angiotensin system and kallikrein-kinin system in ovariectomized mice.

    Science.gov (United States)

    Zhang, Y; Wang, L; Song, Y; Zhao, X; Wong, M S; Zhang, W

    2016-03-01

    The skeletal renin-angiotensin system contributes to the development of osteoporosis. The renin inhibitor aliskiren exhibited beneficial effects on trabecular bone of osteoporotic mice, and this action might be mediated through angiotensin and bradykinin receptor pathways. This study implies the potential application of renin inhibitor in the management for postmenopausal osteoporosis. The skeletal renin-angiotensin system plays key role in the pathological process of osteoporosis. The present study is designed to elucidate the effect of renin inhibitor aliskiren on trabecular bone and its potential action mechanism in ovariectomized (OVX) mice. The OVX mice were treated with low dose (5 mg/kg) or high dose (25 mg/kg) of aliskiren or its vehicle for 8 weeks. The bone turnover markers were measured by ELISA. The structural parameters of trabecular bone at lumbar vertebra (LV) and distal femoral metaphysis were measured by micro-CT. The expression of messenger RNA (mRNA) and protein was studied by RT-PCR and immunoblotting, respectively. Aliskiren treatment reduced urinary excretion of calcium and serum level of tartrate-resistant acid phosphatase in OVX mice. The treatment with aliskiren significantly increased bone volume (BV/TV) and connectivity density (Conn.D) of trabecular bone at LV-2 and LV-5 as well as dramatically enhanced BV/TV, Conn.D, bone mineral density (BMD/BV) and decreased bone surface (BS/BV) at the distal femoral end. Aliskiren significantly down-regulated the expression of angiotensinogen, angiotensin II (Ang II), Ang II type 1 receptor, bradykinin receptor (BR)-1, and osteocytic-specific gene sclerostin as well as the osteoclast-specific genes, including carbonic anhydrase II, matrix metalloproteinase-9, and cathepsin K. This study revealed that renin inhibitor aliskiren exhibited the beneficial effects on trabecular bone of ovariectomy-induced osteoporotic mice, and the underlying mechanism for this action might be mediated through Ang II and

  5. Assessment of vertebral microarchitecture in overt and mild Cushing's syndrome using trabecular bone score.

    Science.gov (United States)

    Vinolas, Helene; Grouthier, Virginie; Mehsen-Cetre, Nadia; Boisson, Amandine; Winzenrieth, Renaud; Schaeverbeke, Thierry; Mesguich, Charles; Bordenave, Laurence; Tabarin, Antoine

    2018-05-21

    Osteoporotic fractures associated with Cushing's syndrome (CS) may occur despite normal bone mineral density (BMD). Few studies have described alterations in vertebral microarchitecture in glucocorticoid-treated patients and during CS. Trabecular bone score (TBS) estimates trabecular microarchitecture from dual-energy X-ray absorptiometry acquisitions. Our aim was to compare vertebral BMD and TBS in patients with overt CS and mild autonomous cortisol secretion (MACE), and following cure of overt CS. University Hospital. Monocentric retrospective cross-sectional and longitudinal studies of consecutive patients. A total of 110 patients were studied: 53 patients had CS (35, 11 and 7 patients with Cushing's disease, bilateral macronodular adrenal hyperplasia and ectopic ACTH secretion respectively); 39 patients had MACE (10 patients with a late post-operative recurrence of Cushing's disease and 29 patients with adrenal incidentalomas); 18 patients with non-secreting adrenal incidentalomas. 14 patients with overt CS were followed for up to 2 years after cure. Vertebral osteoporosis at BMD and degraded microarchitecture at TBS were found in 24% and 43% of patients with CS, respectively (P < .03). As compared to patients with nonsecreting incidentalomas, patients with MACE had significantly decreased TBS (P < .04) but not BMD. Overt fragility fractures tended to be associated with low TBS (P = .07) but not with low BMD. TBS, but not BMD values, decreased with the intensity of hypercortisolism independently of its aetiology (P < .01). Following remission of CS, TBS improved more markedly and rapidly than BMD (10% vs 3%, respectively; P < .02). Trabecular bone score may be a promising, noninvasive, widely available and inexpensive complementary tool for the routine assessment of the impact of CS and MACE on bone in clinical practice. © 2018 John Wiley & Sons Ltd.

  6. Estimating the mechanical competence parameter of the trabecular bone: a neural network approach

    Directory of Open Access Journals (Sweden)

    Érica Regina Filletti

    Full Text Available Abstract Introduction The mechanical competence parameter (MCP of the trabecular bone is a parameter that merges the volume fraction, connectivity, tortuosity and Young modulus of elasticity, to provide a single measure of the trabecular bone structural quality. Methods As the MCP is estimated for 3D images and the Young modulus simulations are quite consuming, in this paper, an alternative approach to estimate the MCP based on artificial neural network (ANN is discussed considering as the training set a group of 23 in vitro vertebrae and 12 distal radius samples obtained by microcomputed tomography (μCT, and 83 in vivo distal radius magnetic resonance image samples (MRI. Results It is shown that the ANN was able to predict with very high accuracy the MCP for 29 new samples, being 6 vertebrae and 3 distal radius bones by μCT and 20 distal radius bone by MRI. Conclusion There is a strong correlation (R2 = 0.97 between both techniques and, despite the small number of testing samples, the Bland-Altman analysis shows that ANN is within the limits of agreement to estimate the MCP.

  7. Bonding strength of glass-ceramic trabecular-like coatings to ceramic substrates for prosthetic applications.

    Science.gov (United States)

    Chen, Qiang; Baino, Francesco; Pugno, Nicola M; Vitale-Brovarone, Chiara

    2013-04-01

    A new approach based on the concepts of quantized fracture mechanics (QFM) is presented and discussed in this paper to estimate the bonding strength of trabecular-like coatings, i.e. glass-ceramic scaffolds mimicking the architecture of cancellous bone, to ceramic substrates. The innovative application of glass-derived scaffolds as trabecular-like coatings is proposed in order to enhance the osteointegration of prosthetic ceramic devices. The scaffolds, prepared by polymeric sponge replication, are joined to alumina substrates by a dense glass-ceramic coating (interlayer) and the so-obtained 3-layer constructs are investigated from micro-structural, morphological and mechanical viewpoints. In particular, the fracture strengths of three different crack propagation modes, i.e. glass-derived scaffold fracture, interface delamination or mixed fracture, are predicted in agreement with those of experimental mechanical tests. The approach proposed in this work could have interesting applications towards an ever more rational design of bone tissue engineering biomaterials and coatings, in view of the optimization of their mechanical properties for making them actually suitable for clinical applications. Copyright © 2012 Elsevier B.V. All rights reserved.

  8. Rural versus nonrural differences in BMC, volumetric BMD, and bone size: a population-based cross-sectional study.

    Science.gov (United States)

    Specker, Bonny; Binkley, Teresa; Fahrenwald, Nancy

    2004-12-01

    Despite reports of lower fracture risk among rural versus urban populations, few studies have investigated rural versus urban differences in bone mineral content (BMC) and bone mineral density (BMD). Population differences in cross-sectional bone geometry and understanding lifestyle factors responsible for these differences may reveal insights into the reason for differences in fracture risk. We hypothesized that if lifestyle differences in bone mass, size, and geometry are a result of muscle strength, activity, or dietary differences, Hutterite and rural populations should have greater bone mass compared to nonrural populations. The study population consisted of 1189 individuals: 504 rural Hutterites (188 men), 349 rural individuals (>75% life farming, 184 men), and 336 nonrural individuals (never lived on farm, 134 men) aged 20 to 66 years. BMC, bone area, and areal BMD (aBMD) of the total body (TB), hip, femoral neck (FN), and spine by DXA; volumetric BMD (vBMD) and bone geometry at the 4% and 20% radius; polar stress strain index (pSSI), a measure of bone strength, at the 20% pQCT site; and strength, 7-day activity recall, and 24-h diet recall were collected and compared among groups. Hutterite women and men had greater grip strength compared to rural and nonrural populations (both, P BMC and areal size than the nonrural population, while Hutterites had greater BMC and areal size than rural population at some (TB, FN for females only), but not all (proximal hip), sites. Cortical vBMD was inversely associated with periosteal circumference at the 20% radius in women (r=-0.25, P BMC, aBMD, vBMD, or bone size.

  9. Trabecular bone strains around a dental implant and associated micromotions--a micro-CT-based three-dimensional finite element study.

    Science.gov (United States)

    Limbert, Georges; van Lierde, Carl; Muraru, O Luiza; Walboomers, X Frank; Frank, Milan; Hansson, Stig; Middleton, John; Jaecques, Siegfried

    2010-05-07

    The first objective of this computational study was to assess the strain magnitude and distribution within the three-dimensional (3D) trabecular bone structure around an osseointegrated dental implant loaded axially. The second objective was to investigate the relative micromotions between the implant and the surrounding bone. The work hypothesis adopted was that these virtual measurements would be a useful indicator of bone adaptation (resorption, homeostasis, formation). In order to reach these objectives, a microCT-based finite element model of an oral implant implanted into a Berkshire pig mandible was developed along with a robust software methodology. The finite element mesh of the 3D trabecular bone architecture was generated from the segmentation of microCT scans. The implant was meshed independently from its CAD file obtained from the manufacturer. The meshes of the implant and the bone sample were registered together in an integrated software environment. A series of non-linear contact finite element (FE) analyses considering an axial load applied to the top of the implant in combination with three sets of mechanical properties for the trabecular bone tissue was devised. Complex strain distribution patterns are reported and discussed. It was found that considering the Young's modulus of the trabecular bone tissue to be 5, 10 and 15GPa resulted in maximum peri-implant bone microstrains of about 3000, 2100 and 1400. These results indicate that, for the three sets of mechanical properties considered, the magnitude of maximum strain lies within an homeostatic range known to be sufficient to maintain/form bone. The corresponding micro-motions of the implant with respect to the bone microstructure were shown to be sufficiently low to prevent fibrous tissue formation and to favour long-term osseointegration. Copyright 2010 Elsevier Ltd. All rights reserved.

  10. Laser Trabeculoplasty Induces Changes in the Trabecular Meshwork Glycoproteome: A pilot study

    OpenAIRE

    Amelinckx, Adriana; Castello, Maria; Arrieta-Quintero, Esdras; Lee, Tinthu; Salas, Nelson; Hernandez, Eleut; Lee, Richard K.; Bhattacharya, Sanjoy K.; Parel, Jean-Marie A

    2009-01-01

    Laser trabeculoplasty (LT) is a commonly used modality of treatment for glaucoma. The mechanism by which LT lowers the intraocular pressure (IOP) is unknown. Using cat eyes, selective laser trabeculoplasty (SLT) with a Q-switched frequency doubled Nd:YAG laser was used to treat the trabecular meshwork (TM). Laser treated TM was then subjected to proteomic analysis for detection of molecular changes and histological analysis for the detection of structural and protein expression patterns. In a...

  11. Trabecular bone mineral density measured by quantitative CT of the lumbar spine in children and adolescents: reference values and peak bone mass

    International Nuclear Information System (INIS)

    Berthold, L.D.; Alzen, G.; Haras, G.; Mann, M.

    2006-01-01

    Purpose: The aim of this study was to assess bone density values in the trabecular substance of the lumbar vertebral column in children and young adults in Germany from infancy to the age of peak bone mass. Materials and Methods: We performed quantiative computed tomography (QCT) on the first lumbar vertebra in 28 children and adolescents without diseases that may influence bone metabolism (15 boys, 13 girls, mean ages 11 and 8 years, respectively). We also measured 17 healthy young adults (9 men, 8 women, mean ages 20 and 21 years). We used a Somatom Balance Scanner (Siemens, Erlangen) and the Siemens Osteo software. Scan parameters: Slice thickness 1 cm, 80 kV, 81 or 114 mAs. We measured the trabecular bone density and the area and height of the vertebra and calculated the volume and content of calcium hydroxyapatite (Ca-HA) in the trabecular substance of the first lumbar vertebra. Results: Prepubertal boys had a mean bone density of 148.5 (median [med] 150.1, standard deviation [SD] 15.4) mg/Ca-HA per ml bone, and prepubertal girls had a mean density of 149.5 (med 150.8, SD 23.5) mg/ml. We did not observe a difference between prepubertal boys and girls. After puberty there was a significant difference (p<0.001) between males and females: Mean density (male) 158.0, med 162.5, SD 24.0 mg/ml, mean density (female) 191.2, med 191.3, SD 17.7 mg/ml. The Ca-HA content in the trabecular bone of the first lumbar vertebra was 1.1 (med 1.1, SD 0.5) g for prepubertal boys and 1.1 (0.9, 0.4) g for prepubertal girls. For post-pubertal males, the mean Ca-HA content was 3.5 g, med 3.5 SD 0.5 g, and for post-pubertal females, the mean content was 2.8, med 2.7, SD 0.4 g. Conclusion: The normal trabecular bone mineral density is 150 mg/ml with a standard deviation of 20 mg/ml independent of age or gender until the beginning of puberty. Peak bone mass (bone mineral content) in the trabecular substance of the lumbar vertebral column is higher in males than in females, and peak bone

  12. Bone Geometry, Volumetric Density, Microarchitecture, and Estimated Bone Strength Assessed by HR-pQCT in Adult Patients With Type 1 Diabetes Mellitus

    DEFF Research Database (Denmark)

    Shanbhogue, Vikram V; Hansen, Stinus; Frost, Morten

    2015-01-01

    The primary goal of this cross-sectional in vivo study was to assess peripheral bone microarchitecture, bone strength, and bone remodeling in adult type 1 diabetes (T1D) patients with and without diabetic microvascular disease (MVD+ and MVD-, respectively) and to compare them with age-, gender......-, and height-matched healthy control subjects (CoMVD+ and CoMVD-, respectively). The secondary goal was to assess differences in MVD- and MVD+ patients. Fifty-five patients with T1DM (MVD+ group: n = 29) were recruited from the Funen Diabetes Database. Dual-energy X-ray absorptiometry (DXA), high...... in MVD+ and MVD- groups in comparison to controls, they were similar between the MVD+ and MVD- groups. The results of our study suggest that the presence of MVD was associated with deficits in cortical and trabecular bone vBMD and microarchitecture that could partly explain the excess skeletal fragility...

  13. Population-Stratified Analysis of Bone Mineral Density Distribution in Cervical and Lumbar Vertebrae of Chinese from Quantitative Computed Tomography

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yong [Department of Radiology, The Fourth Clinical Medical College of Peking University, Beijing Jishuitan Hospital, Beijing 100035 (China); Zhou, Zhuang [Department of Orthopedic Oncology, The Third Hospital of Hebei Medical University, Shijiazhuang 050051 (China); Wu, Cheng' ai; Zhao, Danhui; Wang, Chao [Beijing Institute of Traumatology and Orthopedics, Beijing 100035 (China); Cheng, Xiaoguang; Cai, Wei; Wang, Ling; Duanmu, Yangyang; Zhang, Chenxin [Department of Radiology, The Fourth Clinical Medical College of Peking University, Beijing Jishuitan Hospital, Beijing 100035 (China); Tian, Wei [Department of Spine Surgery, The Fourth Clinical Medical College of Peking University, Beijing Jishuitan Hospital, Beijing 100035 (China)

    2016-11-01

    To investigate the bone mineral density (BMD) of cervical vertebrae in a population-stratified manner and correlate with that of the lumbar vertebrae. Five hundred and ninety-eight healthy volunteers (254 males, 344 females), ranging from 20 to 64 years of age, were recruited for volumetric BMD (vBMD) measurements by quantitative computed tomography. Basic information (age, height, weight, waistline, and hipline), and vBMD of the cervical and lumbar vertebrae (C2–7 and L2–4) were recorded. Comparisons among sex, age groups and different levels of vertebrae were analyzed using analysis of variance. Linear regression was performed for relevance of different vertebral levels. The vBMD of cervical and lumbar vertebrae was higher in females than males in each age group. The vBMD of the cervical and lumbar vertebrae in males and the vBMD of lumbar vertebrae in females decreased with aging. In each age group, the vBMD of the cervical vertebrae was higher than that of the lumbar vertebrae with gradual decreases from C2 to C7 except for C3; moreover, the vBMD of C6 and C7 was significantly different from that of C2–5. Correlations of vBMD among different cervical vertebrae (females: r = 0.62–0.94; males: r = 0.63–0.94) and lumbar vertebrae (males: r = 0.93–0.98; females: r = 0.82–0.97) were statistically significant at each age group. The present study provided normative data of cervical vertebrae in an age- and sex-stratified manner. Sex differences in vBMD prominently vary with age, which can be helpful to design a more comprehensive pre-operative surgical plan.

  14. Population=stratified analysis of bone mineral density distribution in cervical and lumbar vertebrae of chinese from quantitative computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yong; Cheng, Xiaoguang; Cai, Wei; Wang, Ling; Duanmu, Yangyang; Zhang, Chen Xin [Dept. of Radiology, The Fourth Clinical Medical College of Peking University, Beijing Jishuitan Hospital, Beijing (China); Zhou, Zhuang [Dept. of Orthopedic Oncology, The Third Hospital of Hebei Medical University, Shijiazhuang (China); Wu, Cheng' ai; Zhao, Danhui; Wang, Chao [Beijing Institute of Traumatology and Orthopedics, Beijing (China); Tian, Wei [Dept. of Spine Surgery, The Fourth Clinical Medical College of Peking University, Beijing Jishuitan Hospital, Beijing (China)

    2016-09-15

    To investigate the bone mineral density (BMD) of cervical vertebrae in a population-stratified manner and correlate with that of the lumbar vertebrae. Five hundred and ninety-eight healthy volunteers (254 males, 344 females), ranging from 20 to 64 years of age, were recruited for volumetric BMD (vBMD) measurements by quantitative computed tomography. Basic information (age, height, weight, waistline, and hipline), and vBMD of the cervical and lumbar vertebrae (C2–7 and L2–4) were recorded. Comparisons among sex, age groups and different levels of vertebrae were analyzed using analysis of variance. Linear regression was performed for relevance of different vertebral levels. The vBMD of cervical and lumbar vertebrae was higher in females than males in each age group. The vBMD of the cervical and lumbar vertebrae in males and the vBMD of lumbar vertebrae in females decreased with aging. In each age group, the vBMD of the cervical vertebrae was higher than that of the lumbar vertebrae with gradual decreases from C2 to C7 except for C3; moreover, the vBMD of C6 and C7 was significantly different from that of C2–5. Correlations of vBMD among different cervical vertebrae (females: r = 0.62–0.94; males: r = 0.63–0.94) and lumbar vertebrae (males: r = 0.93–0.98; females: r = 0.82–0.97) were statistically significant at each age group. The present study provided normative data of cervical vertebrae in an age- and sex-stratified manner. Sex differences in vBMD prominently vary with age, which can be helpful to design a more comprehensive pre-operative surgical plan.

  15. Assessment of trabecular bone changes around endosseous implants using image analysis techniques: A preliminary study

    International Nuclear Information System (INIS)

    Zuki, Mervet El; Omami, Galal; Horner, Keith

    2014-01-01

    The objective of this study was to assess the trabecular bone changes that occurred around functional endosseous dental implants by means of radiographic image analysis techniques. Immediate preoperative and postoperative periapical radiographs of de-identified implant patients at the University Dental Hospital of Manchester were retrieved, screened for specific inclusion criteria, digitized, and quantified for structural elements of the trabecular bone around the endosseous implants, by using image analysis techniques. Data were analyzed using SPSS version 11.5. P values of less than 0.05 were considered statistically significant. A total of 12 implants from 11 patients were selected for the study, and 26 regions of interest were obtained. There was a significant increase in the bone area in terms of the mean distance between nodes (p=0.006) and a significant decrease in the marrow area in terms of the bone area (p=0.006) and the length of marrow spaces (p=0.032). It appeared that the bone around the implant underwent remodeling that resulted in a net increase in bone after implant placement.

  16. Assessment of trabecular bone changes around endosseous implants using image analysis techniques: A preliminary study

    Energy Technology Data Exchange (ETDEWEB)

    Zuki, Mervet El [Dept. of Oral Medicine and Radiology, Benghazi University College of Dentistry, Benghazi (Libya); Omami, Galal [Oral Diagnosis and Polyclinics, Faculty of Dentistry, The University of Hong Kong (Hong Kong); Horner, Keith [Dept. of Oral Radiology, University Dental Hospital of Manchester, Manchester (United Kingdom)

    2014-06-15

    The objective of this study was to assess the trabecular bone changes that occurred around functional endosseous dental implants by means of radiographic image analysis techniques. Immediate preoperative and postoperative periapical radiographs of de-identified implant patients at the University Dental Hospital of Manchester were retrieved, screened for specific inclusion criteria, digitized, and quantified for structural elements of the trabecular bone around the endosseous implants, by using image analysis techniques. Data were analyzed using SPSS version 11.5. P values of less than 0.05 were considered statistically significant. A total of 12 implants from 11 patients were selected for the study, and 26 regions of interest were obtained. There was a significant increase in the bone area in terms of the mean distance between nodes (p=0.006) and a significant decrease in the marrow area in terms of the bone area (p=0.006) and the length of marrow spaces (p=0.032). It appeared that the bone around the implant underwent remodeling that resulted in a net increase in bone after implant placement.

  17. CBFA1 and topoisomerase I mRNA levels decline during cellular aging of human trabecular osteoblasts

    DEFF Research Database (Denmark)

    Christiansen, Mette; Kveiborg, M.; Kassem, M.

    2000-01-01

    In order to understand the reasons for age-related impairment of the function of bone forming osteoblasts, we have examined the steady-state mRNA levels of the transcription factor CBFA1 and topoisomerase I during cellular aging of normal human trabecular osteoblasts, by the use of semiquantitati...

  18. Voxel effects within digital images of trabecular bone and their consequences on chord-length distribution measurements

    International Nuclear Information System (INIS)

    Rajon, D.A.; Shah, A.P.; Watchman, C.J.; Bolch, W.E.; Jokisch, D.W.; Patton, P.W.

    2002-01-01

    Chord-length distributions through the trabecular regions of the skeleton have been investigated since the early 1960s. These distributions have become important features for bone marrow dosimetry; as such, current models rely on the accuracy of their measurements. Recent techniques utilize nuclear magnetic resonance (NMR) microscopy to acquire 3D images of trabecular bone that are then used to measure 3D chord-length distributions by Monte Carlo methods. Previous studies have shown that two voxel effects largely affect the acquisition of these distributions within digital images. One is particularly pertinent as it dramatically changes the shape of the distribution and reduces its mean. An attempt was made to reduce this undesirable effect and good results were obtained for a single-sphere model using minimum acceptable chord (MAC) methods (Jokisch et al 2001 Med. Phys. 28 1493-504). The goal of the present work is to extend the study of these methods to more general models in order to better quantify their consequences. First, a mathematical model of a trabecular bone sample was used to test the usefulness of the MAC methods. The results showed that these methods were not efficient for this simulated bone model. These methods were further tested on a single voxelized sphere over a large range of voxel sizes. The results showed that the MAC methods are voxel-size dependent and overestimate the mean chord length for typical resolutions used with NMR microscopy. The study further suggests that bone and marrow chord-length distributions currently utilized in skeletal dosimetry models are most likely affected by voxel effects that yield values of mean chord length lower than their true values. (author)

  19. Trabecular meshwork stiffness in glaucoma.

    Science.gov (United States)

    Wang, Ke; Read, A Thomas; Sulchek, Todd; Ethier, C Ross

    2017-05-01

    Alterations in stiffness of the trabecular meshwork (TM) may play an important role in primary open-angle glaucoma (POAG), the second leading cause of blindness. Specifically, certain data suggest an association between elevated intraocular pressure (IOP) and increased TM stiffness; however, the underlying link between TM stiffness and IOP remains unclear and requires further study. We here first review the literature on TM stiffness measurements, encompassing various species and based on a number of measurement techniques, including direct approaches such as atomic force microscopy (AFM) and uniaxial tension tests, and indirect methods based on a beam deflection model. We also briefly review the effects of several factors that affect TM stiffness, including lysophospholipids, rho-kinase inhibitors, cytoskeletal disrupting agents, dexamethasone (DEX), transforming growth factor-β 2 (TGF-β 2 ), nitric oxide (NO) and cellular senescence. We then describe a method we have developed for determining TM stiffness measurement in mice using a cryosection/AFM-based approach, and present preliminary data on TM stiffness in C57BL/6J and CBA/J mouse strains. Finally, we investigate the relationship between TM stiffness and outflow facility between these two strains. The method we have developed shows promise for further direct measurements of mouse TM stiffness, which may be of value in understanding mechanistic relations between outflow facility and TM biomechanical properties. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Strain rate dependency of bovine trabecular bone under impact loading at sideways fall velocity.

    Science.gov (United States)

    Enns-Bray, William S; Ferguson, Stephen J; Helgason, Benedikt

    2018-05-03

    There is currently a knowledge gap in scientific literature concerning the strain rate dependent properties of trabecular bone at intermediate strain rates. Meanwhile, strain rates between 10 and 200/s have been observed in previous dynamic finite element models of the proximal femur loaded at realistic sideways fall speeds. This study aimed to quantify the effect of strain rate (ε̇) on modulus of elasticity (E), ultimate stress (σ u ), failure energy (U f ), and minimum stress (σ m ) of trabecular bone in order to improve the biofidelity of material properties used in dynamic simulations of sideways fall loading on the hip. Cylindrical cores of trabecular bone (D = 8 mm, L gauge  = 16 mm, n = 34) from bovine proximal tibiae and distal femurs were scanned in µCT (10 µm), quantifying apparent density (ρ app ) and degree of anisotropy (DA), and subsequently impacted within a miniature drop tower. Force of impact was measured using a piezoelectric load cell (400 kHz), while displacement during compression was measured from high speed video (50,000 frames/s). Four groups, with similar density distributions, were loaded at different impact velocities (0.84, 1.33, 1.75, and 2.16 m/s) with constant kinetic energy (0.4 J) by adjusting the impact mass. The mean strain rates of each group were significantly different (p < 0.05) except for the two fastest impact speeds (p = 0.09). Non-linear regression models correlated strain rate, DA, and ρ app with ultimate stress (R 2  = 0.76), elastic modulus (R 2  = 0.63), failure energy (R 2  = 0.38), and minimum stress (R 2  = 0.57). These results indicate that previous estimates of σ u could be under predicting the mechanical properties at strain rates above 10/s. Copyright © 2018 Elsevier Ltd. All rights reserved.

  1. Trabecular bone microstructure is impaired in the proximal femur of human immunodeficiency virus-infected men with normal bone mineral density.

    Science.gov (United States)

    Kazakia, Galateia J; Carballido-Gamio, Julio; Lai, Andrew; Nardo, Lorenzo; Facchetti, Luca; Pasco, Courtney; Zhang, Chiyuan A; Han, Misung; Parrott, Amanda Hutton; Tien, Phyllis; Krug, Roland

    2018-02-01

    There is evidence that human immunodeficiency virus (HIV) infection and antiretroviral therapy (ART) are independent risk factors for osteoporosis and fracture which is not solely explained by changes in bone mineral density. Thus, we hypothesized that the assessment of trabecular microstructure might play an important role for bone quality in this population and might explain the increased fracture risk. In this study, we have assessed bone microstructure in the proximal femur using high-resolution magnetic resonance imaging (MRI) as well as in the extremities using high resolution peripheral quantitative computed tomography (HR-pQCT) in HIV-infected men and healthy controls and compared these findings to those based on areal bone mineral density (aBMD) derived from dual X-ray absorptiometry (DXA) which is the standard clinical parameter for the diagnosis of osteoporosis. Eight HIV-infected men and 11 healthy age-matched controls were recruited and informed consent was obtained before each scan. High-resolution MRI of the proximal femur was performed using fully balanced steady state free precession (bSSFP) on a 3T system. Three volumes of interest at corresponding anatomic locations across all subjects were defined based on registrations of a common template. Four MR-based trabecular microstructural parameters were analyzed at each region: fuzzy bone volume fraction (f-BVF), trabecular number (Tb.N), thickness (Tb.Th), and spacing (Tb.Sp). In addition, the distal radius and distal tibia were imaged with HR-pQCT. Four HR-pQCT-based microstructural parameters were analyzed: trabecular bone volume fraction (BV/TV), Tb.N, Tb.Th, and Tb.Sp. Total hip and spine aBMD were determined from DXA. Microstructural bone parameters derived from MRI at the proximal femur and from HR-pQCT at the distal tibia showed significantly lower bone quality in HIV-infected patients compared to healthy controls. In contrast, DXA aBMD data showed no significant differences between HIV

  2. Neocellularization and neovascularization of nanosized bioactive glass-coated decellularized trabecular bone scaffolds

    KAUST Repository

    Gerhardt, Lutz Christian

    2012-09-11

    In this study, the in vivo recellularization and neovascularization of nanosized bioactive glass (n-BG)-coated decellu-larized trabecular bone scaffolds were studied in a rat model and quantified using stereological analyses. Based on the highest amount of vascular endothelial growth factor (VEGF) secreted by human fibroblasts grown on n-BG coatings (0-1.245 mg/cm 2), decellularized trabecular bone samples (porosity: 43-81%) were coated with n-BG particles. Grown on n-BG particles at a coating density of 0.263 mg/cm2, human fibroblasts produced 4.3 times more VEGF than on uncoated controls. After 8 weeks of implantation in Sprague-Dawley rats, both uncoated and n-BG-coated samples were well infiltrated with newly formed tissue (47-48%) and blood vessels (3-4%). No significant differences were found in cellularization and vascularization between uncoated bone scaffolds and n-BG-coated scaffolds. This finding indicates that the decellularized bone itself may exhibit growth-promoting properties induced by the highly interconnected pore microarchitecture and/or proteins left behind on decellularized scaffolds. Even if we did not find proangiogenic effects in n-BG-coated bone scaffolds, a bioactive coating is considered to be beneficial to impart osteoinductive and osteoconductive properties to decellularized bone. n-BG-coated bone grafts have thus high clinical potential for the regeneration of complex tissue defects given their ability for recellularization and neovascularization. © 2012 Wiley Periodicals, Inc.

  3. Texture analysis of trabecular bone using conventional radiographs: medical imaging and osteoporosis

    International Nuclear Information System (INIS)

    Karunanithi, R.; Panicker, T.M.R.; Paul Korath, M.; Jagadeesan, K.; Ganesan, S.

    2008-01-01

    Osteoporosis is characterized by reduced bone mass, microstructural deterioration with advancing age, and an increase in fracture risk. The accurate clinical assessment of bone strength and fracture risk is important for management of bone loss diseases such as osteoporosis risk. From a clinical point of view, microarchitecture is an interesting aspect to study and define patterns of bone alterations with aging and pathology. Microarchitecture seems to be a determinant of bone fragility independent of bone density. Moreover, bone microarchitecture seems to be important to understand the mechanisms of bone fragility independent of bone density. Moreover bone microarchitecture seems to be important to understand the mechanisms of bone fragility as well as the action of the drugs used to prevent osteoporotic fractures. In the case of osteoporosis the bone texture of the trabecular network as it appears on the plain radiographs can be quantified by applying image processing tools. Among the factors conditioning bone strength and osteoporotic fractures, bone mineral density is the most important and the best studied. Though, other factors also play a role: macroarchitecture of bones, cortical thickness, quality of bone crystal and of collagen network and trabecular microarchitecture. The microarchitecture plays a major role, and is an aspect of the definition of osteoporosis. Therefore, it would be very helpful if these alterations could be measured in addition to bone mineral density with noninvasive techniques, such as radiographs, and to assess the status of the bone by texture analysis

  4. Evolution of bone disease after kidney transplantation: A prospective histomorphometric analysis of trabecular and cortical bone.

    Science.gov (United States)

    Carvalho, Catarina; Magalhães, Juliana; Pereira, Luciano; Simões-Silva, Liliana; Castro-Ferreira, Inês; Frazão, João Miguel

    2016-01-01

    Post-transplant bone disease results from multiple factors, including previous bone and mineral metabolism disturbances and effects from transplant-related medications. Bone biopsy remains the gold-standard diagnostic tool. We aimed to prospectively evaluate trabecular and cortical bone by histomorphometry after kidney transplantation. Seven patients, willing to perform follow-up bone biopsy, were included in the study. Dual-X-ray absorptiometry and trans-iliac bone biopsy were performed within the first 2 months after renal transplantation and repeated after 2-5 years of follow-up. Follow-up biopsy revealed a significant decrease in osteoblast surface/bone surface (0.91 ± 0.81 to 0.47 ± 0.12%, P = 0.036), osteoblasts number/bone surface (0.45 (0.23, 0.94) to 0.00/mm(2) , P = 0.018) and erosion surface/bone surface (3.75 ± 2.02 to 2.22 ± 1.38%, P = 0.044). A decrease in trabecular number (3.55 (1.81, 2.89) to 1.55/mm (1.24, 2.06), P = 0.018) and increase in trabecular separation (351.65 ± 135.04 to 541.79 ± 151.91 μm, P = 0.024) in follow-up biopsy suggest loss in bone quantity. We found no significant differences in cortical analysis, except a reduction in external cortical osteonal eroded surface (5.76 (2.94, 13.97) to 3.29% (0.00, 6.67), P = 0.043). Correlations between bone histomorphometric and dual-X-ray absorptiometry parameters gave inconsistent results. The results show a reduction in bone activity, suggesting increased risk of adynamic bone and loss of bone volume. Cortical bone seems less affected by post-transplant biological changes in the first years after kidney transplantation. © 2015 Asian Pacific Society of Nephrology.

  5. Skeletal development of mice lacking bone sialoprotein (BSP--impairment of long bone growth and progressive establishment of high trabecular bone mass.

    Directory of Open Access Journals (Sweden)

    Wafa Bouleftour

    Full Text Available Adult Ibsp-knockout mice (BSP-/- display shorter stature, lower bone turnover and higher trabecular bone mass than wild type, the latter resulting from impaired bone resorption. Unexpectedly, BSP knockout also affects reproductive behavior, as female mice do not construct a proper "nest" for their offsprings. Multiple crossing experiments nonetheless indicated that the shorter stature and lower weight of BSP-/- mice, since birth and throughout life, as well as their shorter femur and tibia bones are independent of the genotype of the mothers, and thus reflect genetic inheritance. In BSP-/- newborns, µCT analysis revealed a delay in membranous primary ossification, with wider cranial sutures, as well as thinner femoral cortical bone and lower tissue mineral density, reflected in lower expression of bone formation markers. However, trabecular bone volume and osteoclast parameters of long bones do not differ between genotypes. Three weeks after birth, osteoclast number and surface drop in the mutants, concomitant with trabecular bone accumulation. The growth plates present a thinner hypertrophic zone in newborns with lower whole bone expression of IGF-1 and higher IHH in 6 days old BSP-/- mice. At 3 weeks the proliferating zone is thinner and the hypertrophic zone thicker in BSP-/- than in BSP+/+ mice of either sex, maybe reflecting a combination of lower chondrocyte proliferation and impaired cartilage resorption. Six days old BSP-/- mice display lower osteoblast marker expression but higher MEPE and higher osteopontin(Opn/Runx2 ratio. Serum Opn is higher in mutants at day 6 and in adults. Thus, lack of BSP alters long bone growth and membranous/cortical primary bone formation and mineralization. Endochondral development is however normal in mutant mice and the accumulation of trabecular bone observed in adults develops progressively in the weeks following birth. Compensatory high Opn may allow normal endochondral development in BSP-/- mice

  6. Tributyltin induces distinct effects on cortical and trabecular bone in female C57Bl/6J mice.

    Science.gov (United States)

    Watt, James; Baker, Amelia H; Meeks, Brett; Pajevic, Paola D; Morgan, Elise F; Gerstenfeld, Louis C; Schlezinger, Jennifer J

    2018-09-01

    The retinoid X receptors (RXR), peroxisome proliferator activated receptor gamma (PPARγ), and liver X receptors (LXR) all have been shown to regulate bone homeostasis. Tributyltin (TBT) is an environmental contaminant that is a dual RXRα/β and PPARγ agonist. TBT induces RXR, PPARγ, and LXR-mediated gene transcription and suppresses osteoblast differentiation in vitro. Bone marrow multipotent mesenchymal stromal cells derived from female C57BL/6J mice were more sensitive to suppression of osteogenesis by TBT than those derived from male mice. In vivo, oral gavage of 12 week old female, C57Bl/6J mice with 10 mg/kg TBT for 10 weeks resulted in femurs with a smaller cross-sectional area and thinner cortex. Surprisingly, TBT induced significant increases in trabecular thickness, number, and bone volume fraction. TBT treatment did not change the Rankl:Opg RNA ratio in whole bone, and histological analyses showed that osteoclasts in the trabecular space were minimally reduced. In contrast, expression of cardiotrophin-1, an osteoblastogenic cytokine secreted by osteoclasts, increased. In primary bone marrow macrophage cultures, TBT marginally inhibited the number of osteoclasts that differentiated, in spite of significantly suppressing expression of osteoclast markers Nfatc1, Acp5, and Ctsk and resorptive activity. TBT induced expression of RXR- and LXR-dependent genes in whole bone and in vitro osteoclast cultures. However, only an RXR antagonist, but not an LXR antagonist, significantly inhibited TBTs ability to suppress osteoclast differentiation. These results suggest that TBT has distinct effects on cortical versus trabecular bone, likely resulting from independent effects on osteoblast and osteoclast differentiation that are mediated through RXR. © 2018 Wiley Periodicals, Inc.

  7. Spontaneous mutation of Dock7 results in lower trabecular bone mass and impaired periosteal expansion in aged female Misty mice.

    Science.gov (United States)

    Le, Phuong T; Bishop, Kathleen A; Maridas, David E; Motyl, Katherine J; Brooks, Daniel J; Nagano, Kenichi; Baron, Roland; Bouxsein, Mary L; Rosen, Clifford J

    2017-12-01

    Misty mice (m/m) have a loss of function mutation in Dock7 gene, a guanine nucleotide exchange factor, resulting in low bone mineral density, uncoupled bone remodeling and reduced bone formation. Dock7 has been identified as a modulator of osteoblast number and in vitro osteogenic differentiation in calvarial osteoblast culture. In addition, m/m exhibit reduced preformed brown adipose tissue innervation and temperature as well as compensatory increase in beige adipocyte markers. While the low bone mineral density phenotype is in part due to higher sympathetic nervous system (SNS) drive in young mice, it is unclear what effect aging would have in mice homozygous for the mutation in the Dock7 gene. We hypothesized that age-related trabecular bone loss and periosteal envelope expansion would be altered in m/m. To test this hypothesis, we comprehensively characterized the skeletal phenotype of m/m at 16, 32, 52, and 78wks of age. When compared to age-matched wild-type control mice (+/+), m/m had lower areal bone mineral density (aBMD) and areal bone mineral content (aBMC). Similarly, both femoral and vertebral BV/TV, Tb.N, and Conn.D were decreased in m/m while there was also an increase in Tb.Sp. As low bone mineral density and decreased trabecular bone were already present at 16wks of age in m/m and persisted throughout life, changes in age-related trabecular bone loss were not observed highlighting the role of Dock7 in controlling trabecular bone acquisition or bone loss prior to 16wks of age. Cortical thickness was also lower in the m/m across all ages. Periosteal and endosteal circumferences were higher in m/m compared to +/+ at 16wks. However, endosteal and periosteal expansion were attenuated in m/m, resulting in m/m having lower periosteal and endosteal circumferences by 78wks of age compared to +/+, highlighting the critical role of Dock7 in appositional bone expansion. Histomorphometry revealed that osteoblasts were nearly undetectable in m/m and marrow

  8. Human trabecular meshwork cells express BMP antagonist mRNAs and proteins.

    Science.gov (United States)

    Tovar-Vidales, Tara; Fitzgerald, Ashley M; Clark, Abbot F

    2016-06-01

    Glaucoma patients have elevated aqueous humor and trabecular meshwork (TM) levels of transforming growth factor-beta2 (TGF-β2). TGF-β2 has been associated with increased extracellular matrix (ECM) deposition (i.e. fibronectin), which is attributed to the increased resistance of aqueous humor outflow through the TM. We have previously demonstrated that bone morphogenetic protein (BMP) 4 selectively counteracts the profibrotic effect of TGF-β2 with respect to ECM synthesis in the TM, and this action is reversed by the BMP antagonist gremlin. Thus, the BMP and TGF-β signaling pathways antagonize each other's antifibrotic and profibrotic roles. The purpose of this study was to determine whether cultured human TM cells: (a) express other BMP antagonists including noggin, chordin, BMPER, BAMBI, Smurf1 and 2, and (b) whether expression of these proteins is regulated by exogenous TGF-β2 treatment. Primary human trabecular meshwork (TM) cells were grown to confluency and treated with TGF-β2 (5 ng/ml) for 24 or 48 h in serum-free medium. Untreated cell served as controls. qPCR and Western immunoblots (WB) determined that human TM cells expressed mRNAs and proteins for the BMP antagonist proteins: noggin, chordin, BMPER, BAMBI, and Smurf1/2. Exogenous TGF-β2 decreased chordin, BMPER, BAMBI, and Smurf1 mRNA and protein expression. In contrast, TGF-β2 increased secreted noggin and Smurf2 mRNA and protein levels. BMP antagonist members are expressed in the human TM. These molecules may be involved in the normal function of the TM as well as TM pathogenesis. Altered expression of BMP antagonist members may lead to functional changes in the human TM. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Trabecular bone strains around a dental implant and associated micromotions--a micro-CT-based three-dimensional finite element study.

    NARCIS (Netherlands)

    Limbert, G.; Lierde, C. van; Muraru, O.L.; Walboomers, X.F.; Frank, M.; Hansson, S.; Middleton, J.; Jaecques, S.

    2010-01-01

    The first objective of this computational study was to assess the strain magnitude and distribution within the three-dimensional (3D) trabecular bone structure around an osseointegrated dental implant loaded axially. The second objective was to investigate the relative micromotions between the

  10. Protection of trabecular bone in ovariectomized rats by turmeric (Curcuma longa L.) is dependent on extract composition.

    Science.gov (United States)

    Wright, Laura E; Frye, Jennifer B; Timmermann, Barbara N; Funk, Janet L

    2010-09-08

    Extracts prepared from turmeric (Curcuma longa L., [Zingiberaceae]) containing bioactive phenolic curcuminoids were evaluated for bone-protective effects in a hypogonadal rat model of postmenopausal osteoporosis. Three-month female Sprague-Dawley rats were ovariectomized (OVX) and treated with a chemically complex turmeric fraction (41% curcuminoids by weight) or a curcuminoid-enriched turmeric fraction (94% curcuminoids by weight), both dosed at 60 mg/kg 3x per week, or vehicle alone. Effects of two months of treatment on OVX-induced bone loss were followed prospectively by serial assessment of bone mineral density (BMD) of the distal femur using dual-energy X-ray absorptiometry (DXA), while treatment effects on trabecular bone microarchitecture were assessed at two months by microcomputerized tomography (microCT). Chemically complex turmeric did not prevent bone loss, however, the curcuminoid-enriched turmeric prevented up to 50% of OVX-induced loss of trabecular bone and also preserved the number and connectedness of the strut-like trabeculae. These results suggest that turmeric may have bone-protective effects but that extract composition is a critical factor.

  11. The Relationship between Trabecular Bone Structure Modeling Methods and the Elastic Modulus as Calculated by FEM

    Directory of Open Access Journals (Sweden)

    Tomasz Topoliński

    2012-01-01

    Full Text Available Trabecular bone cores were collected from the femoral head at the time of surgery (hip arthroplasty. Investigated were 42 specimens, from patients with osteoporosis and coxarthrosis. The cores were scanned used computer microtomography (microCT system at an isotropic spatial resolution of 36 microns. Image stacks were converted to finite element models via a bone voxel-to-element algorithm. The apparent modulus was calculated based on the assumptions that for the elastic properties, E=10 MPa and ν=0.3. The compressive deformation as calculated by finite elements (FE analysis was 0.8%. The models were coarsened to effectively change the resolution or voxel size (from 72 microns to 288 microns or from 72 microns to 1080 microns. The aim of our study is to determine how an increase in the distance between scans changes the elastic properties as calculated by FE models. We tried to find a border value voxel size at which the module values were possible to calculate. As the voxel size increased, the mean voxel volume increased and the FEA-derived apparent modulus decreased. The slope of voxel size versus modulus relationship correlated with several architectural indices of trabecular bone.

  12. Computational modelling of the mechanics of trabecular bone and marrow using fluid structure interaction techniques.

    Science.gov (United States)

    Birmingham, E; Grogan, J A; Niebur, G L; McNamara, L M; McHugh, P E

    2013-04-01

    Bone marrow found within the porous structure of trabecular bone provides a specialized environment for numerous cell types, including mesenchymal stem cells (MSCs). Studies have sought to characterize the mechanical environment imposed on MSCs, however, a particular challenge is that marrow displays the characteristics of a fluid, while surrounded by bone that is subject to deformation, and previous experimental and computational studies have been unable to fully capture the resulting complex mechanical environment. The objective of this study was to develop a fluid structure interaction (FSI) model of trabecular bone and marrow to predict the mechanical environment of MSCs in vivo and to examine how this environment changes during osteoporosis. An idealized repeating unit was used to compare FSI techniques to a computational fluid dynamics only approach. These techniques were used to determine the effect of lower bone mass and different marrow viscosities, representative of osteoporosis, on the shear stress generated within bone marrow. Results report that shear stresses generated within bone marrow under physiological loading conditions are within the range known to stimulate a mechanobiological response in MSCs in vitro. Additionally, lower bone mass leads to an increase in the shear stress generated within the marrow, while a decrease in bone marrow viscosity reduces this generated shear stress.

  13. Prospective case series on trabecular-iris angle status after an acute episode of phacomorphic angle closure

    Directory of Open Access Journals (Sweden)

    Jacky Lee

    2013-02-01

    Full Text Available AIM:To investigate the trabecular-iris angle with ultrasound biomicroscopy (UBM post cataract extraction after an acute attack of phacomorphic angle closure.METHODS: This prospective study involved 10 cases of phacomorphic angle closure that underwent cataract extraction and intraocular lens insertion after intraocular pressure (IOP lowering. Apart from visual acuity and IOP, the trabecular-iris angle was measured by gonioscopy and UBM at 3 months post attack.RESULTS: In 10 consecutive cases of acute phacomorphic angle closure from December 2009 to December 2010, gonioscopic findings showed peripheral anterior synechiae (PAS ≤ 90° in 30% of phacomorphic patients and a mean Shaffer grading of (3.1±1.0. UBM showed a mean angle of (37.1°±4.5° in the phacomorphic eye with the temporal quadrant being the most opened and (37.1°±8.0° in the contralateral uninvolved eye. The mean time from consultation to cataract extraction was (1.4±0.7 days and the mean total duration of phacomorphic angle closure was (3.6±2.8 days but there was no correlation to the degree of angle closure on UBM (Spearman correlation P=0.7. The presenting mean IOP was (50.5±7.4 mmHg and the mean IOP at 3 months was (10.5±3.4 mmHg but there were no correlations with the degree of angle closure (Spearman correlations P=0.9.CONCLUSION:An open trabecular-iris angle and normal IOP can be achieved after an acute attack of phacomorphic angle closure if cataract extraction is performed within 1 day - 2 days after IOP control. Gonioscopic findings were in agreement with UBM, which provided a more specific and object angle measurement. The superior angle is relatively more narrowed compared to the other quadrants. All contralateral eyes in this series had open angles.

  14. Chitosan nanofiber scaffold improves bone healing via stimulating trabecular bone production due to upregulation of the Runx2/osteocalcin/alkaline phosphatase signaling pathway

    Science.gov (United States)

    Ho, Ming-Hua; Yao, Chih-Jung; Liao, Mei-Hsiu; Lin, Pei-I; Liu, Shing-Hwa; Chen, Ruei-Ming

    2015-01-01

    Osteoblasts play critical roles in bone formation. Our previous study showed that chitosan nanofibers can stimulate osteoblast proliferation and maturation. This translational study used an animal model of bone defects to evaluate the effects of chitosan nanofiber scaffolds on bone healing and the possible mechanisms. In this study, we produced uniform chitosan nanofibers with fiber diameters of approximately 200 nm. A bone defect was surgically created in the proximal femurs of male C57LB/6 mice, and then the left femur was implanted with chitosan nanofiber scaffolds for 21 days and compared with the right femur, which served as a control. Histological analyses revealed that implantation of chitosan nanofiber scaffolds did not lead to hepatotoxicity or nephrotoxicity. Instead, imaging analyses by X-ray transmission and microcomputed tomography showed that implantation of chitosan nanofiber scaffolds improved bone healing compared with the control group. In parallel, microcomputed tomography and bone histomorphometric assays further demonstrated augmentation of the production of new trabecular bone in the chitosan nanofiber-treated group. Furthermore, implantation of chitosan nanofiber scaffolds led to a significant increase in the trabecular bone thickness but a reduction in the trabecular parameter factor. As to the mechanisms, analysis by confocal microscopy showed that implantation of chitosan nanofiber scaffolds increased levels of Runt-related transcription factor 2 (Runx2), a key transcription factor that regulates osteogenesis, in the bone defect sites. Successively, amounts of alkaline phosphatase and osteocalcin, two typical biomarkers that can simulate bone maturation, were augmented following implantation of chitosan nanofiber scaffolds. Taken together, this translational study showed a beneficial effect of chitosan nanofiber scaffolds on bone healing through stimulating trabecular bone production due to upregulation of Runx2-mediated alkaline

  15. Dosimetric validation of synthetic trabecular bone generated by parametric Monte Carlo Method; Validação dosimétrica de trabéculas ósseas sintéticas geradas por método Monte Carlo paramétrico

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, F.G.; Andrade, A.F.G. de; Vieira, J.W., E-mail: baby.oliveira@hotmail.com.br, E-mail: arthurfelandrade@gmail.com, E-mail: jose.wilson59@uol.com.br [Instituto Federal de Pernambuco (IFPE), Recife, PE (Brazil); Oliveira, A.C.H. de, E-mail: oliveira_ach@yahoo.com [Universidade Federal Rural de Pernambuco (UFRPE), Recife, PE (Brazil); Lima, F.R.A., E-mail: falima@cnen.gov.br [Centro Regional de Ciências Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife-PE (Brazil)

    2017-07-01

    One of the greatest challenges of numerical dosimetry is to estimate the dose of ionizing radiation absorbed by the soft tissues that are located in bone trabecular. Due to the difficulty in obtaining micro-CT images of real bone samples (OR), the need for the generation of synthetic bone trabecular appeared. In this work, virtual synthetic trabecular samples (BU), generated by Monte Carlo methods parameterized by the Burr XII probability density function (FDP), and their OR equivalents were submitted to dosimetric evaluations in the adult male Computational Exposure Model (MCE) in orthostatic position (MSTA) coupled to the EGSnrc software with idealized photon-emitting sources and targeting the two most radiosensitive bone tissues: red bone marrow and the foramen-bone surface of trabecular bones, sternum, spine, femur, pelvis and skull regions. When comparing the dosimetric results of the two sample sets, it was found that the overall relative error presented was 4.34%. It is concluded that the synthetic trabecular generated by FDPs with the same characteristics as the Burr XII FDP can successfully replace the OR bones in similar bone dosimetry tests.

  16. Radiography of the mandible prior to endosseous implant treatment. Localization of the mandibular canal and assessment of trabecular bone

    Energy Technology Data Exchange (ETDEWEB)

    Lindh, C.

    1996-03-01

    Mandibular autopsy specimens were examined with different radiographic techniques in order to evaluate the visibility of the mandibular canal and the measurement accuracy of distances related to the mandibular canal. Hypocycloidal, spiral and computed tomography (CT) were superior to periapical and panoramic radiography in visualizing the mandibular canal. The tomographic techniques were more accurate when measurements of distances related to the mandibular canal were performed. No difference in measurement accuracy was found between the tomographic techniques. Concerning visibility of the mandibular canal, interobserver agreement was lowest for periapical radiography and highest for CT. Intraobserver agreement was moderate or good for all techniques. A high interobserver variation was found for measurability of distances related to the mandibular canal. The trabecular bone tissue in mandibular autopsy specimens was studied concerning different characteristics. A classification system to be used prior to implant treatment, based on the trabecular pattern in periapical radiographs, was proposed. 74 refs.

  17. Radiography of the mandible prior to endosseous implant treatment. Localization of the mandibular canal and assessment of trabecular bone

    International Nuclear Information System (INIS)

    Lindh, C.

    1996-03-01

    Mandibular autopsy specimens were examined with different radiographic techniques in order to evaluate the visibility of the mandibular canal and the measurement accuracy of distances related to the mandibular canal. Hypocycloidal, spiral and computed tomography (CT) were superior to periapical and panoramic radiography in visualizing the mandibular canal. The tomographic techniques were more accurate when measurements of distances related to the mandibular canal were performed. No difference in measurement accuracy was found between the tomographic techniques. Concerning visibility of the mandibular canal, interobserver agreement was lowest for periapical radiography and highest for CT. Intraobserver agreement was moderate or good for all techniques. A high interobserver variation was found for measurability of distances related to the mandibular canal. The trabecular bone tissue in mandibular autopsy specimens was studied concerning different characteristics. A classification system to be used prior to implant treatment, based on the trabecular pattern in periapical radiographs, was proposed. 74 refs

  18. Trabecular Meshwork Height in Primary Open-Angle Glaucoma Versus Primary Angle-Closure Glaucoma.

    Science.gov (United States)

    Masis, Marisse; Chen, Rebecca; Porco, Travis; Lin, Shan C

    2017-11-01

    To determine if trabecular meshwork (TM) height differs between primary open-angle glaucoma (POAG) and primary angle-closure glaucoma (PACG) eyes. Prospective, cross-sectional clinical study. Adult patients were consecutively recruited from glaucoma clinics at the University of California, San Francisco, from January 2012 to July 2015. Images were obtained from spectral-domain optical coherence tomography (Cirrus OCT; Carl Zeiss Meditec, Inc, Dublin, California, USA). Univariate and multivariate linear mixed models comparing TM height and glaucoma type were performed to assess the relationship between TM height and glaucoma subtype. Mixed-effects regression was used to adjust for the use of both eyes in some subjects. The study included 260 eyes from 161 subjects, composed of 61 men and 100 women. Mean age was 70 years (SD 11.77). There were 199 eyes (123 patients) in the POAG group and 61 eyes (38 patients) in the PACG group. Mean TM heights in the POAG and PACG groups were 812 ± 13 μm and 732 ± 27 μm, respectively, and the difference was significant in univariate analysis (P = .004) and in multivariate analysis (β = -88.7 [24.05-153.5]; P = .008). In this clinic-based population, trabecular meshwork height is shorter in PACG patients compared to POAG patients. This finding may provide insight into the pathophysiology of angle closure and provide assistance in future diagnosis, prevention, and management of the angle-closure spectrum of disorders. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Usefulness of the Trabecular Bone Score for assessing the risk of osteoporotic fracture.

    Science.gov (United States)

    Redondo, L; Puigoriol, E; Rodríguez, J R; Peris, P; Kanterewicz, E

    2018-04-01

    The trabecular bone score (TBS) is an imaging technique that assesses the condition of the trabecular microarchitecture. Preliminary results suggest that TBS, along with the bone mineral density assessment, could improve the calculation of the osteoporotic fracture risk. The aim of this study was to analyse TBS values and their relationship with the clinical characteristics, bone mineral density and history of fractures of a cohort of posmenopausal women. We analysed 2,257 posmenopausal women from the FRODOS cohort, which was created to determine the risk factors for osteoporotic fracture through a clinical survey and bone densitometry with vertebral morphometry. TBS was applied to the densitometry images. TBS values ≤1230 were considered indicative of degraded microarchitecture. We performed a simple and multiple linear regression to determine the factors associated with this index. The mean TBS value in L1-L4 was 1.203±0.121. Some 55.3% of the women showed values indicating degraded microarchitecture. In the multiple linear regression analysis, the factors associated with low TBS values were age, weight, height, spinal T-score, glucocorticoid treatment, presence of type 2 diabetes and a history of fractures due to frailty. TBS showed microarchitecture degradation values in the participants of the FRODOS cohort and was associated with anthropometric factors, low bone mineral density values, the presence of fractures, a history of type 2 diabetes mellitus and the use of glucocorticoids. Copyright © 2017 Elsevier España, S.L.U. and Sociedad Española de Medicina Interna (SEMI). All rights reserved.

  20. Characterization of drug-release kinetics in trabecular bone from titania nanotube implants

    Directory of Open Access Journals (Sweden)

    Aw MS

    2012-09-01

    Full Text Available Moom Sinn Aw,1 Kamarul A Khalid,2,3 Karan Gulati,1 Gerald J Atkins,2 Peter Pivonka,4 David M Findlay,2 Dusan Losic11School of Chemical Engineering, 2Discipline of Orthopaedics and Trauma, The University of Adelaide, Adelaide, SA, Australia; 3Department of Orthopaedics, Traumatology and Rehabilitation, Faculty of Medicine, International Islamic University Malaysia, Kuantan, Pahang, Malaysia; 4Engineering Computational Biology Group, School of Computer Science and Software Engineering, The University of Western Australia, Perth, WA, AustraliaPurpose: The aim of this study was to investigate the application of the three-dimensional bone bioreactor for studying drug-release kinetics and distribution of drugs in the ex vivo cancellous bone environment, and to demonstrate the application of nanoengineered titanium (Ti wires generated with titania nanotube (TNT arrays as drug-releasing implants for local drug deliveryMethods: Nanoengineered Ti wires covered with a layer of TNT arrays implanted in bone were used as a drug-releasing implant. Viable bovine trabecular bone was used as the ex vivo bone substrate embedded with the implants and placed in the bone reactor. A hydrophilic fluorescent dye (rhodamine B was used as the model drug, loaded inside the TNT–Ti implants, to monitor drug release and transport in trabecular bone. The distribution of released model drug in the bone was monitored throughout the bone structure, and concentration profiles at different vertical (0–5 mm and horizontal (0–10 mm distances from the implant surface were obtained at a range of release times from 1 hour to 5 days.Results: Scanning electron microscopy confirmed that well-ordered, vertically aligned nanotube arrays were formed on the surface of prepared TNT–Ti wires. Thermogravimetric analysis proved loading of the model drug and fluorescence spectroscopy was used to show drug-release characteristics in-vitro. The drug release from implants inserted into bone ex

  1. Influence of the pore fluid on the phase velocity in bovine trabecular bone In Vitro: Prediction of the biot model

    Science.gov (United States)

    Lee, Kang Il

    2013-01-01

    The present study aims to investigate the influence of the pore fluid on the phase velocity in bovine trabecular bone in vitro. The frequency-dependent phase velocity was measured in 20 marrow-filled and water-filled bovine femoral trabecular bone samples. The mean phase velocities at frequencies between 0.6 and 1.2 MHz exhibited significant negative dispersions for both the marrow-filled and the water-filled samples. The magnitudes of the dispersions showed no significant differences between the marrow-filled and the water-filled samples. In contrast, replacement of marrow by water led to a mean increase in the phase velocity of 27 m/s at frequencies from 0.6 to 1.2 MHz. The theoretical phase velocities of the fast wave predicted by using the Biot model for elastic wave propagation in fluid-saturated porous media showed good agreements with the measurements.

  2. Age-related mechanical strength evolution of trabecular bone under fatigue damage for both genders: Fracture risk evaluation.

    Science.gov (United States)

    Ben Kahla, Rabeb; Barkaoui, Abdelwahed; Merzouki, Tarek

    2018-05-04

    Bone tissue is a living composite material, providing mechanical and homeostatic functions, and able to constantly adapt its microstructure to changes in long term loading. This adaptation is conducted by a physiological process, known as "bone remodeling". This latter is manifested by interactions between osteoclasts and osteoblasts, and can be influenced by many local factors, via effects on bone cell differentiation and proliferation. In the current work, age and gender effects on damage rate evolution, throughout life, have been investigated using a mechanobiological finite element modeling. To achieve the aim, a mathematical model has been developed, coupling both cell activities and mechanical behavior of trabecular bone, under cyclic loadings. A series of computational simulations (ABAQUS/UMAT) has been performed on a 3D human proximal femur, allowing to investigate the effects of mechanical and biological parameters on mechanical strength of trabecular bone, in order to evaluate the fracture risk resulting from fatigue damage. The obtained results revealed that mechanical stimulus amplitude affects bone resorption and formation rates, and indicated that age and gender are major factors in bone response to the applied loadings. Copyright © 2018 Elsevier Ltd. All rights reserved.

  3. Automated selection of trabecular bone regions in knee radiographs

    International Nuclear Information System (INIS)

    Podsiadlo, P.; Wolski, M.; Stachowiak, G. W.

    2008-01-01

    Osteoarthritic (OA) changes in knee joints can be assessed by analyzing the structure of trabecular bone (TB) in the tibia. This analysis is performed on TB regions selected manually by a human operator on x-ray images. Manual selection is time-consuming, tedious, and expensive. Even if a radiologist expert or highly trained person is available to select regions, high inter- and intraobserver variabilities are still possible. A fully automated image segmentation method was, therefore, developed to select the bone regions for numerical analyses of changes in bone structures. The newly developed method consists of image preprocessing, delineation of cortical bone plates (active shape model), and location of regions of interest (ROI). The method was trained on an independent set of 40 x-ray images. Automatically selected regions were compared to the ''gold standard'' that contains ROIs selected manually by a radiologist expert on 132 x-ray images. All images were acquired from subjects locked in a standardized standing position using a radiography rig. The size of each ROI is 12.8x12.8 mm. The automated method results showed a good agreement with the gold standard [similarity index (SI)=0.83 (medial) and 0.81 (lateral) and the offset=[-1.78, 1.27]x[-0.65,0.26] mm (medial) and [-2.15, 1.59]x[-0.58, 0.52] mm (lateral)]. Bland and Altman plots were constructed for fractal signatures, and changes of fractal dimensions (FD) to region offsets calculated between the gold standard and automatically selected regions were calculated. The plots showed a random scatter and the 95% confidence intervals were (-0.006, 0.008) and (-0.001, 0.011). The changes of FDs to region offsets were less than 0.035. Previous studies showed that differences in FDs between non-OA and OA bone regions were greater than 0.05. ROIs were also selected by a second radiologist and then evaluated. Results indicated that the newly developed method could replace a human operator and produces bone regions

  4. Bone ingrowth potential of electron beam and selective laser melting produced trabecular-like implant surfaces with and without a biomimetic coating

    NARCIS (Netherlands)

    Biemond, J.E.; Hannink, G.; Verdonschot, Nicolaas Jacobus Joseph; Buma, P.

    2013-01-01

    The bone ingrowth potential of trabecular-like implant surfaces produced by either selective laser melting (SLM) or electron beam melting (EBM), with or without a biomimetic calciumphosphate coating, was examined in goats. For histological analysis and histomorphometry of bone ingrowth depth and

  5. [Radiographic appraisal between metal and bone interosculate backfill after total hip arthroplasty with trabecular metal cup].

    Science.gov (United States)

    Li, Wei; Zhou, Yi-Xin; Wu, Jian; Xu, Hui; Ji, Song-Jie

    2009-02-15

    To evaluate the bone refilling in the interface between the trabecular metal (TM) acetabular shell and the bone surface according to consecutive X film measuring after surgery. From July 2006 to July 2007, 35 patients (40 hips) accepted total hip replacement using trabecular metal monoblock acetabular cup system (TM). The cup was made of a ellipse shaped press fit Tantalum shell and high cross-linked PE liner (Longevity) with 28 mm inner diameter. The patients demography was: 16 male (20 hips), 19 female (20 hips), 5 bilateral hip replacements, age from 41 - 71 (mean 53), including 18 avascular necrosis hips, 16 osteoarthritis hips (including those secondary to a dysplasia hip), 4 avascular necrosis hips after femoral neck fracture, 2 Ankylosis Spondylitis. All the 40 total hip replacements used posterior approach, using hemispherical acetabular reamer and 2 mm press fit of final metal shell without screw fixation. The consecutive X film was taken at the end time of surgery and 2, 6, 12, 24 weeks, and 12 months. The clinical results was evaluate according to Harris scoring system, and the standard pelvis AP X film was measured at the interface between metal shell and the acetabular bone surface, witch was divided into five regions (A, B, C, D, E). Totally 32 patients (37 hips) were followed with average 8.7 months (7 - 12 months). The Harris before surgery was 50.5 (32 - 85), promoted to 91.0 (72 - 100), including 29 excellent, 6 good, 2 fair, and the total excellent and good rate was 94.6%. Complications include 4 patients leg length discrepancy from 1 - 2 cm, 3 patients moderate thigh pain and released after conservative therapy. No infection and dislocation was found. Twenty-one patients (23 hips) were found lucent line at the bone-metal interface from 1 - 5 mm, most common in B region and BC boundary than C, D, and CD boundary. All the patients followed was found the lucent line disappeared and refilled with bone at X film 24 weeks after surgery, however, no

  6. Effect of a novel load-bearing trabecular Nitinol scaffold on rabbit radius bone regeneration

    Energy Technology Data Exchange (ETDEWEB)

    Gotman, Irena, E-mail: gotman@technion.ac.il; Gutmanas, Elazar Y., E-mail: gutmanas@technion.ac.il [Department of Materials Science and Engineering, Techion-Israel Institute of Technology, Haifa, 32000 Israel (Israel); National Research Tomsk Polytechnic University, Tomsk, 634050 (Russian Federation); Zaretzky, Asaph [The Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, 31096 Israel (Israel); Psakhie, Sergey G. [National Research Tomsk Polytechnic University, Tomsk, 634050 (Russian Federation); Institute of Strength Physics and Materials Science SB RAS, Tomsk, 634055 (Russian Federation)

    2015-10-27

    The research aim was to evaluate the bone regeneration capability of novel load-bearing NiTi alloy (Nitinol) scaffolds in a critical-size defect (CSD) model. High strength “trabecular Nitinol” scaffolds were prepared by PIRAC (Powder Immersion Reaction Assisted Coating) annealing of the highly porous Ni foam in Ti powder at 900°C. This was followed by PIRAC nitriding to mitigate the release of potentially toxic Ni ions. Scaffolds phase composition and microstructure were characterized by X-ray diffraction and scanning electron microscopy (SEM/EDS), and their mechanical properties were tested in compression. New Zealand white rabbits received bone defect in right radius and were divided in four groups randomly. In the control group, nothing was placed in the defect. In other groups, NiTi scaffolds were implanted in the defect: (i) as produced, (ii) loaded with bone marrow aspirate (BMA), and (iii) biomimetically CaP-coated. The animals were sacrificed after 12 weeks. The forelimbs with scaffolds were resected, fixed, sectioned and examined in SEM. New bone formation inside the scaffold was studied by EDS analysis and by the processing of backscattered electron images. Bone ingrowth into the scaffold was observed in all implant groups, mostly next to the ulna. New bone formation was strongly enhanced by BMA loading and biomimeatic CaP coating, the bone penetrating as much as 1–1.5 mm into the scaffold. The results of this preliminary study demonstrate that the newly developed high strength trabecular Nitinol scaffolds can be successfully used for bone regeneration in critical size defects.

  7. Age-related changes in trabecular and cortical bone microstructure.

    Science.gov (United States)

    Chen, Huayue; Zhou, Xiangrong; Fujita, Hiroshi; Onozuka, Minoru; Kubo, Kin-Ya

    2013-01-01

    The elderly population has substantially increased worldwide. Aging is a complex process, and the effects of aging are myriad and insidious, leading to progressive deterioration of various organs, including the skeleton. Age-related bone loss and resultant osteoporosis in the elderly population increase the risk for fractures and morbidity. Osteoporosis is one of the most common conditions associated with aging, and age is an independent risk factor for osteoporotic fractures. With the development of noninvasive imaging techniques such as computed tomography (CT), micro-CT, and high resolution peripheral quantitative CT (HR-pQCT), imaging of the bone architecture provides important information about age-related changes in bone microstructure and estimates of bone strength. In the past two decades, studies of human specimens using imaging techniques have revealed decreased bone strength in older adults compared with younger adults. The present paper addresses recently studied age-related changes in trabecular and cortical bone microstructure based primarily on HR-pQCT and micro-CT. We specifically focus on the three-dimensional microstructure of the vertebrae, femoral neck, and distal radius, which are common osteoporotic fracture sites.

  8. Crohn’s disease and Trabecular Metal implants: a report of two cases and literature review

    Directory of Open Access Journals (Sweden)

    C. Peron

    2015-10-01

    Full Text Available Aim The aim of the present study was to report two cases with Crohn’s disease in whom dental implants successfully osseointegrated and remained functionally stable up to 13 and 12 months of follow-up, respectively. Cases presentation In cases 1 (age 35 years and 2 (age 36 years, tooth 24 and 14, respectively, were atraumatically extracted and a particulated bone grafting material (buccal and palatal aspect of the defect and a Trabecular Metal implant (11.5 mm length, 4.7 mm diameter were inserted in each extraction socket. After implant placement and abutment connection with the final torque (25 Ncm, the provisional restoration was adapted in the oral cavity creating the emergence profile. The provisional crown was screw-retained and had slight occlusal contacts in the centric occlusion (intercuspation position. A periapical radiograph was taken as a control radiograph at the baseline. Postoperatively, antibiotics were prescribed as well as analgesics and an oral rinse was recommended. In both cases, the provisional restoration was removed after 2 weeks and replaced with a full ceramic restoration. Case-1 and case-2 were followed up after 13 months and 12 months respectively. In both cases postoperative healing was uneventful and radiographs taken at follow-up showed no evidence of crestal bone loss. Implants in both cases demonstrated an excellent clinical condition at follow-up. Conclusion Trabecular Metal implants can osseointegrate and remain functionally stable in patients with Crohn’s disease.

  9. Microstructural properties of trabecular bone autografts: comparison of men and women with and without osteoporosis.

    Science.gov (United States)

    Xie, Fen; Zhou, Bin; Wang, Jian; Liu, Tang; Wu, Xiyu; Fang, Rui; Kang, Yijun; Dai, Ruchun

    2018-03-05

    The microstructure of autologous bone grafts from men over 50 years old and postmenopausal women undergoing spinal fusion were evaluated using micro-CT. We demonstrated postmenopausal women, especially those with osteoporosis (OP) presented more serious microarchitectural deterioration of bone grafts. This study was undertaken to determine microstructural properties of cancellous bone used as autologous bone grafts from osteoporosis patients undergoing lumbar fusion by comparing microstructural indices to controls. Cancellous bone specimens from spinous processes were obtained from 41 postmenopausal women (osteoporosis women, n = 19; controls, n = 22) and 26 men over 50 years old (osteoporosis men, n = 8; controls, n = 18) during lumbar fusion surgery. The microstructural parameters were measured using micro-CT. Significant difference in bone volume fraction (BV/TV), specific bone surface (BS/BV), trabecular thickness (Tb.Th), and structure model index (SMI) value existed between postmenopausal women with OP and controls. Significant difference in trabecular number (Tb.N) existed between men over 50 years old with OP and controls. Postmenopausal women exhibited lower BV/TV, Tb.Th, and higher SMI value than men over 50 years old. Postmenopausal women with OP exhibited lower BV/TV, Tb.Th, and higher BS/BV than men over 50 years old with OP. Post-menopausal women and older men with OP have worse bone quality in autografts than non-osteoporotic men and women. Postmenopausal women with OP presented serious microarchitectural deterioration in older population.

  10. Cost-effectiveness analysis of iStent trabecular microbypass stent for patients with open-angle glaucoma in Colombia

    OpenAIRE

    Osorio, Urpy; Ordoñez, Angelica

    2018-01-01

    Objective: To estimate cost-effectiveness of trabecular micro bypass stent versus laser trabeculoplasty or medications only, for patients with open-angle glaucoma in setting of Colombian System Health. Methods: This is a cost-effectiveness analysis that based its assumptions in external data sources, used to extrapolate the quality of life related to health, survival and costs. A Markov model, with stages from 0 (ocular hypertension without glaucoma) to 5 and bilateral blindness, was develope...

  11. Expanding the Description of Spaceflight Effects beyond Bone Mineral Density [BMD]: Trabecular Bone Score [TBS] in ISS Astronauts

    Science.gov (United States)

    Sibonga, J. D.; Spector, E. R.; King, L. J.; Evans, H. J.; Smith, S. A.

    2014-01-01

    Dual-energy x-ray absorptiometry [DXA] is the widely-applied bone densitometry method used to diagnose osteoporosis in a terrestrial population known to be at risk for age-related bone loss. This medical test, which measures areal bone mineral density [aBMD] of clinically-relevant skeletal sites (e.g., hip and spine), helps the clinician to identify which persons, among postmenopausal women and men older than 50 years, are at high risk for low trauma or fragility fractures and might require an intervention. The most recognized osteoporotic fragility fracture is the vertebral compression fracture which can lead to kyphosis or hunched backs typically seen in the elderly. DXA measurement of BMD however is recognized to be insufficient as a sole index for assessing fracture risk. DXA's limitation may be related to its inability to monitor changes in structural parameters, such as trabecular vs. cortical bone volumes, bone geometry or trabecular microarchitecture. Hence, in order to understand risks to human health and performance due to space exposure, NASA needs to expand its measurements of bone to include other contributors to skeletal integrity. To this aim, the Bone and Mineral Lab conducted a pilot study for a novel measurement of bone microarchitecture that can be obtained by retrospective analysis of DXA scans. Trabecular Bone Score (TBS) assesses changes to trabecular microarchitecture by measuring the grey color "texture" information extracted from DXA images of the lumbar spine. An analysis of TBS in 51 ISS astronauts was conducted to assess if TBS could detect 1) an effect of spaceflight and 2) a response to countermeasures independent of DXA BMD. In addition, changes in trunk body lean tissue mass and in trunk body fat tissue mass were also evaluated to explore an association between body composition, as impacted by ARED exercise, and bone microarchitecture. The pilot analysis of 51 astronaut scans of the lumbar spine suggests that, following an ISS

  12. Bone size and volumetric density in women with anorexia nervosa receiving estrogen replacement therapy and in women recovered from anorexia nervosa.

    Science.gov (United States)

    Karlsson, M K; Weigall, S J; Duan, Y; Seeman, E

    2000-09-01

    Anorexia nervosa is associated with bone loss during adulthood, but may also delay skeletal growth and mineral accrual during growth. We asked the following questions. 1) Is anorexia nervosa associated with reduced bone size and reduced volumetric bone mineral density (vBMD)? 2) Is estrogen replacement therapy (ERT) or recovery from anorexia nervosa associated with normal bone size and vBMD? Using dual-energy x-ray absorptiometry, we measured bone size and vBMD of the third lumbar vertebra and femoral neck in a cross-sectional study of 161 female patients: 77 with untreated anorexia nervosa, 58 with anorexia nervosa receiving ERT, 26 recovered from anorexia nervosa, and 205 healthy age-matched controls. Results were expressed as the SD or z-score (mean +/- SEM). Deficits in vertebral body and femoral neck width in untreated women were -1.0 +/- 0.1 and -0.3 +/- 0.1 SD (P anorexia nervosa is due to reduced bone size and reduced vBMD. Although causality cannot be inferred in cross-sectional studies, the data are consistent with the view that malnutrition may contribute to reduced bone size, whereas estrogen deficiency may reduce vBMD. The use of ERT early in disease is a reasonable component of management if the chance of recovery appears remote.

  13. Short-term survival of the trabecular metal cup is similar to that of standard cups used in acetabular revision surgery.

    Science.gov (United States)

    Mohaddes, Maziar; Rolfson, Ola; Kärrholm, Johan

    2015-02-01

    The use of trabecular metal (TM) cups in revision surgery has increased worldwide during the last decade. Since the introduction of the TM cup in Sweden in 2006, this design has gradually replaced other uncemented designs used in Sweden. According to data from the Swedish Hip Arthroplasty Register (SHAR) in 2012, one-third of all uncemented first-time cup revisions were performed using a TM cup. We compared the risk of reoperation and re-revision for TM cups and the 2 other most frequently used cup designs in acetabular revisions reported to the SHAR. The hypothesis was that the performance of TM cups is as good as that of established designs in the short term. The study population consisted of 2,384 patients who underwent 2,460 revisions during the period 2006 through 2012. The most commonly used cup designs were the press-fit porous-coated cup (n = 870), the trabecular metal cup (n = 805), and the cemented all-polyethylene cup (n = 785). 54% of the patients were female, and the median age at index revision was 72 (19-95) years. Reoperation was defined as a second surgical intervention, and re-revision-meaning exchange or removal of the cup-was used as endpoint. The mean follow-up time was 3.3 (0-7) years. There were 215 reoperations, 132 of which were re-revisions. The unadjusted and adjusted risk of reoperation or re-revision was not significantly different for the TM cup and the other 2 cup designs. Our data support continued use of TM cups in acetabular revisions. Further follow-up is necessary to determine whether trabecular metal cups can reduce the re-revision rate in the long term, compared to the less costly porous press-fit and cemented designs.

  14. Assessment of spinal trabecular bone by quantitative CT

    International Nuclear Information System (INIS)

    Adachi, Toshiki; Kozakura, Yoshihiro; Kato, Isamu; Yamamoto, Yoshio

    1988-01-01

    127 normal values of spinal trabecular bone mineral content (BMC) for 67 males (age range : 20 ∼ 77) and 60 females (age range : 23 ∼ 76) were studied by quantitative computed tomography (QCT). We have measured L1, L2 and L3 vertebrae, but there is no significant difference between L1, L2 and L3 BMC, so we caliculated the individual BMC from the average of the three vertebrae data. The BMC value was found to be greatly enfluenced by age. Its maximum at the age of 20 years for males and females, and decreases gradually with an increase in age with a much more reduction seen in the females. The mean value of BMC for the males was approximately 171 mg/ml K 2 HPO 4 equivalent to the 20 - 40 age range years and the females was approximately 183 mg/ml, so that by the age 70, the males were reduced by 35 % to approximately 110 mg/ml, the females were reduced by 50 % to approximately 92 mg/ml. The interrelation was analyzed by using a cubic regression study which revealed an adequate correlation (r = 0.77 in the males, r = 0.85 in the females) between BMC and age. (author)

  15. Axial compressive strength of human vertebrae trabecular bones classified as normal, osteopenic and osteoporotic by quantitative ultrasonometry of calcaneus

    Directory of Open Access Journals (Sweden)

    Reinaldo Cesar

    2017-06-01

    Full Text Available Abstract Introduction Biomechanical assessment of trabecular bone microarchitecture contributes to the evaluation of fractures risk associated with osteoporosis and plays a crucial role in planning preventive strategies. One of the most widely clinical technics used for osteoporosis diagnosis by health professionals is bone dual-energy X-ray absorptiometry (DEXA. However, doubts about its accuracy motivate the introduction of congruent technical analysis such as calcaneal ultrasonometry (Quantitative Ultrasonometry - QUS. Methods Correlations between Bone Quality Index (BQI, determined by calcaneal ultrasonometry of thirty (30 individuals classified as normal, osteopenic and osteoporotic, and elastic modulus (E and ultimate compressive strength (UCS from axial compression tests of ninety (90 proof bodies from human vertebrae trabecular bone, which were extracted from cadavers in the twelfth thoracic region (T12, first and fourth lumbar (L1 and L4. Results Analysis of variance (ANOVA showed significant differences for E (p = 0.001, for UCS (p = 0.0001 and BQI. Spearman’s rank correlation coefficient (rho between BQI and E (r = 0.499 and BQI and UCS (r = 0.508 were moderate. Discussion Calcaneal ultrasonometry technique allowed a moderate estimate of bone mechanical strength and fracture risk associated with osteoporosis in human vertebrae.

  16. Using Non-linear Homogenization to Improve the Performance of Macroscopic Damage Models of Trabecular Bone.

    Science.gov (United States)

    Levrero-Florencio, Francesc; Pankaj, Pankaj

    2018-01-01

    Realistic macro-level finite element simulations of the mechanical behavior of trabecular bone, a cellular anisotropic material, require a suitable constitutive model; a model that incorporates the mechanical response of bone for complex loading scenarios and includes post-elastic phenomena, such as plasticity (permanent deformations) and damage (permanent stiffness reduction), which bone is likely to experience. Some such models have been developed by conducting homogenization-based multiscale finite element simulations on bone micro-structure. While homogenization has been fairly successful in the elastic regime and, to some extent, in modeling the macroscopic plastic response, it has remained a challenge with respect to modeling damage. This study uses a homogenization scheme to upscale the damage behavior from the tissue level (microscale) to the organ level (macroscale) and assesses the suitability of different damage constitutive laws. Ten cubic specimens were each subjected to 21 strain-controlled load cases for a small range of macroscopic post-elastic strains. Isotropic and anisotropic criteria were considered, density and fabric relationships were used in the formulation of the damage law, and a combined isotropic/anisotropic law with tension/compression asymmetry was formulated, based on the homogenized results, as a possible alternative to the currently used single scalar damage criterion. This computational study enhances the current knowledge on the macroscopic damage behavior of trabecular bone. By developing relationships of damage progression with bone's micro-architectural indices (density and fabric) the study also provides an aid for the creation of more precise macroscale continuum models, which are likely to improve clinical predictions.

  17. Assessment of spinal trabecular bone by quantitative computed tomography

    International Nuclear Information System (INIS)

    Soya, Toshio; Seto, Hikaru; Futatsuya, Ryusuke; Kamei, Tetsuya; Kakishita, Masao

    1987-01-01

    151 normal values of spinal trabecular bone mineral content (BMC) for 79 men and 72 women were studied by single energy quantitative computed tomography (QCT). The BMC value has a great relation to age. It has a maximum in the age of 20 years in men and in the age of 20 ∼ 30 years in women, and decreases gradually after these ages with a more rapid reduction in women (1.1 % per year in men and 1.6 % per year in women). In younger generation (under 50 years of age) the average value of the BMC is 180 mg/ml K 2 HPO 4 equivalent in men, 189 mg/ml in women, and in older generation, is 123 mg/ml and 112 mg/ml respectively. In the individual case, the fluctuation of inter-vertebrae (L1, L2 and L3) has large variation, therefore, to estimate one's BMC enoughly the measurement of at least three vertebrae should be done. There found no physical factor which attributes to the BMC value. It is suggested that the BMC are affected by age and sex. (author)

  18. Age-Related Changes in Trabecular and Cortical Bone Microstructure

    Directory of Open Access Journals (Sweden)

    Huayue Chen

    2013-01-01

    Full Text Available The elderly population has substantially increased worldwide. Aging is a complex process, and the effects of aging are myriad and insidious, leading to progressive deterioration of various organs, including the skeleton. Age-related bone loss and resultant osteoporosis in the elderly population increase the risk for fractures and morbidity. Osteoporosis is one of the most common conditions associated with aging, and age is an independent risk factor for osteoporotic fractures. With the development of noninvasive imaging techniques such as computed tomography (CT, micro-CT, and high resolution peripheral quantitative CT (HR-pQCT, imaging of the bone architecture provides important information about age-related changes in bone microstructure and estimates of bone strength. In the past two decades, studies of human specimens using imaging techniques have revealed decreased bone strength in older adults compared with younger adults. The present paper addresses recently studied age-related changes in trabecular and cortical bone microstructure based primarily on HR-pQCT and micro-CT. We specifically focus on the three-dimensional microstructure of the vertebrae, femoral neck, and distal radius, which are common osteoporotic fracture sites.

  19. Electron absorbed fractions of energy and S-values in an adult human skeleton based on {mu}CT images of trabecular bone

    Energy Technology Data Exchange (ETDEWEB)

    Kramer, R; Cassola, V F; Khoury, H J; De O Lira, C A B [Department of Nuclear Energy, Federal University of Pernambuco, Avenida Professor Luiz Freire, 1000, CEP 50740-540, Recife (Brazil); Richardson, R B [Radiation Protection Research and Instrumentation Branch, Atomic Energy of Canada Limited, Chalk River Laboratories, Chalk River, ON, K0J 1J0 (Canada); Vieira, J W [Federal Institute of Education, Science and Technology of Pernambuco, Recife (Brazil); Brown, K Robson, E-mail: rkramer@uol.com.br [Imaging Laboratory, Department of Archaeology and Anthropology, University of Bristol, Bristol (United Kingdom)

    2011-03-21

    When the human body is exposed to ionizing radiation, among the soft tissues at risk are the active marrow (AM) and the bone endosteum (BE) located in tiny, irregular cavities of trabecular bone. Determination of absorbed fractions (AFs) of energy or absorbed dose in the AM and the BE represent one of the major challenges of dosimetry. Recently, at the Department of Nuclear Energy at the Federal University of Pernambuco, a skeletal dosimetry method based on {mu}CT images of trabecular bone introduced into the spongiosa voxels of human phantoms has been developed and applied mainly to external exposure to photons. This study uses the same method to calculate AFs of energy and S-values (absorbed dose per unit activity) for electron-emitting radionuclides known to concentrate in skeletal tissues. The modelling of the skeletal tissue regions follows ICRP110, which defines the BE as a 50 {mu}m thick sub-region of marrow next to the bone surfaces. The paper presents mono-energetic AFs for the AM and the BE for eight different skeletal regions for electron source energies between 1 keV and 10 MeV. The S-values are given for the beta emitters {sup 14}C, {sup 59}Fe, {sup 131}I, {sup 89}Sr, {sup 32}P and {sup 90}Y. Comparisons with results from other investigations showed good agreement provided that differences between methodologies and trabecular bone volume fractions were properly taken into account. Additionally, a comparison was made between specific AFs of energy in the BE calculated for the actual 50 {mu}m endosteum and the previously recommended 10 {mu}m endosteum. The increase in endosteum thickness leads to a decrease of the endosteum absorbed dose by up to 3.7 fold when bone is the source region, while absorbed dose increases by {approx}20% when the beta emitters are in marrow.

  20. Trabecular bone microarchitecture analysis, a way for an early detection of genetic dwarfism? Case study of a dwarf mother's offspring.

    Science.gov (United States)

    Colombo, Antony; Hoogland, Menno; Coqueugniot, Hélène; Dutour, Olivier; Waters-Rist, Andrea

    2018-03-01

    A 66 year-old woman with a disproportionate dwarfism and who bore seven children was discovered at the Middenbeemster archaeological site (The Netherlands). Three are perinates and show no macroscopic or radiological evidence for a FGFR3 mutation causing hypo-or achondroplasia. This mutation induces dysfunction of the growth cartilage, leading to abnormalities in the development of trabecular bone. Because the mutation is autosomal dominant, these perinates have a 50% risk of having been affected. This study determines whether trabecular bone microarchitecture (TBMA) analysis is useful for detecting genetic dwarfism. Proximal metaphyses of humeri were μCT-scanned with a resolution of 7-12 μm. Three volumes of interest were segmented from each bone with TIVMI© software. The TBMA was quantified in BoneJ© using six parameters on which a multivariate analysis was then performed. Two of the Middenbeemster perinates show a quantitatively different TBMA organization. These results and the family's medical history suggest a diagnosis of genetic dwarfism for this two perinates. This study provides evidence to support the efficacy of μCT for diagnosing early-stage bone disease. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Clinical Application of Solid Model Based on Trabecular Tibia Bone CT Images Created by 3D Printer.

    Science.gov (United States)

    Cho, Jaemo; Park, Chan-Soo; Kim, Yeoun-Jae; Kim, Kwang Gi

    2015-07-01

    The aim of this work is to use a 3D solid model to predict the mechanical loads of human bone fracture risk associated with bone disease conditions according to biomechanical engineering parameters. We used special image processing tools for image segmentation and three-dimensional (3D) reconstruction to generate meshes, which are necessary for the production of a solid model with a 3D printer from computed tomography (CT) images of the human tibia's trabecular and cortical bones. We examined the defects of the mechanism for the tibia's trabecular bones. Image processing tools and segmentation techniques were used to analyze bone structures and produce a solid model with a 3D printer. These days, bio-imaging (CT and magnetic resonance imaging) devices are able to display and reconstruct 3D anatomical details, and diagnostics are becoming increasingly vital to the quality of patient treatment planning and clinical treatment. Furthermore, radiographic images are being used to study biomechanical systems with several aims, namely, to describe and simulate the mechanical behavior of certain anatomical systems, to analyze pathological bone conditions, to study tissues structure and properties, and to create a solid model using a 3D printer to support surgical planning and reduce experimental costs. These days, research using image processing tools and segmentation techniques to analyze bone structures to produce a solid model with a 3D printer is rapidly becoming very important.

  2. Characterization of micro-invasive trabecular bypass stents by ex vivo perfusion and computational flow modeling

    Directory of Open Access Journals (Sweden)

    Hunter KS

    2014-03-01

    Full Text Available Kendall S Hunter,1 Todd Fjield,2 Hal Heitzmann,2 Robin Shandas,1 Malik Y Kahook3 1Department of Bioengineering, University of Colorado Denver, Aurora, CO, USA; 2Glaukos Corporation, Laguna Hills, CA, USA; 3University of Colorado Hospital Eye Center, Aurora, CO, USA Abstract: Micro-invasive glaucoma surgery with the Glaukos iStent® or iStent inject® (Glaukos Corporation, Laguna Hills, CA, USA is intended to create a bypass through the trabecular meshwork to Schlemm's canal to improve aqueous outflow through the natural physiologic pathway. While the iStent devices have been evaluated in ex vivo anterior segment models, they have not previously been evaluated in whole eye perfusion models nor characterized by computational fluid dynamics. Intraocular pressure (IOP reduction with the iStent was evaluated in an ex vivo whole human eye perfusion model. Numerical modeling, including computational fluid dynamics, was used to evaluate the flow through the stents over physiologically relevant boundary conditions. In the ex vivo model, a single iStent reduced IOP by 6.0 mmHg from baseline, and addition of a second iStent further lowered IOP by 2.9 mmHg, for a total IOP reduction of 8.9 mmHg. Computational modeling showed that simulated flow through the iStent or iStent inject is smooth and laminar at physiological flow rates. Each stent was computed to have a negligible flow resistance consistent with an expected significant decrease in IOP. The present perfusion results agree with prior clinical and laboratory studies to show that both iStent and iStent inject therapies are potentially titratable, providing clinicians with the opportunity to achieve lower target IOPs by implanting additional stents. Keywords: glaucoma, iStent, trabecular bypass, intraocular pressure, ab-interno, CFD

  3. Multiphoton gonioscopy to image the trabecular meshwork of porcine eyes

    Science.gov (United States)

    Masihzadeh, Omid; Ammar, David A.; Kahook, Malik Y.; Gibson, Emily A.; Lei, Tim C.

    2013-03-01

    The aqueous outflow system (AOS), including the trabecular meshwork (TM), the collector channels (CC) and the Schlemm's canal (SC), regulates intraocular pressure (IOP) through the drainage of the aqueous humor (AH). Abnormal IOP elevation leads to increased pressure stress to retinal ganglion cells, resulting in cell loss that can ultimately lead to complete loss of eyesight. Therefore, development of imaging tools to detect abnormal structural and functional changes of the AOS is important in early diagnosis and prevention of glaucoma. Multiphoton microscopy (MPM), including twophoton autofluorescence (TPAF) and second harmonic generation (SHG), is a label-free microscopic technique that allows molecular specific imaging of biological tissues like the TM. Since the TM and other AOS structures are located behind the highly scattering scleral tissue, transscleral imaging of the TM does not provide enough optical resolution. In this work, a gonioscopic lens is used to allow direct optical access of the TM through the cornea for MPM imaging. Compared to transscleral imaging, the acquired MPM images show improved resolution as individual collagen fiber bundles of the TM can be observed. MPM gonioscopy may have the potential to be developed as a future clinical imaging tool for glaucoma diagnostics.

  4. Direct trabecular meshwork imaging in porcine eyes through multiphoton gonioscopy

    Science.gov (United States)

    Masihzadeh, Omid; Ammar, David A.; Kahook, Malik Y.; Gibson, Emily A.; Lei, Tim C.

    2013-03-01

    The development of technologies to characterize the ocular aqueous outflow system (AOS) is important for the understanding of the pathophysiology of glaucoma. Multiphoton microscopy (MPM) offers the advantage of high-resolution, label-free imaging with intrinsic image contrast because the emitted signals result from the specific biomolecular content of the tissue. Previous attempts to use MPM to image the murine irido-corneal region directly through the sclera have suffered from degradation in image resolution due to scattering of the focused laser light. As a result, transscleral MPM has limited ability to observe fine structures in the AOS. In this work, the porcine irido-corneal angle was successfully imaged through the transparent cornea using a gonioscopic lens to circumvent the highly scattering scleral tissue. The resulting high-resolution images allowed the detailed structures in the trabecular meshwork (TM) to be observed. Multimodal imaging by two-photon autofluorescence and second harmonic generation allowed visualization of different features in the TM without labels and without disruption of the TM or surrounding tissues. MPM gonioscopy is a promising noninvasive imaging tool for high-resolution studies of the AOS, and research continues to explore the potential for future clinical applications in humans.

  5. Machine learning based analytics of micro-MRI trabecular bone microarchitecture and texture in type 1 Gaucher disease.

    Science.gov (United States)

    Sharma, Gulshan B; Robertson, Douglas D; Laney, Dawn A; Gambello, Michael J; Terk, Michael

    2016-06-14

    Type 1 Gaucher disease (GD) is an autosomal recessive lysosomal storage disease, affecting bone metabolism, structure and strength. Current bone assessment methods are not ideal. Semi-quantitative MRI scoring is unreliable, not standardized, and only evaluates bone marrow. DXA BMD is also used but is a limited predictor of bone fragility/fracture risk. Our purpose was to measure trabecular bone microarchitecture, as a biomarker of bone disease severity, in type 1 GD individuals with different GD genotypes and to apply machine learning based analytics to discriminate between GD patients and healthy individuals. Micro-MR imaging of the distal radius was performed on 20 type 1 GD patients and 10 healthy controls (HC). Fifteen stereological and textural measures (STM) were calculated from the MR images. General linear models demonstrated significant differences between GD and HC, and GD genotypes. Stereological measures, main contributors to the first two principal components (PCs), explained ~50% of data variation and were significantly different between males and females. Subsequent PCs textural measures were significantly different between GD patients and HC individuals. Textural measures also significantly differed between GD genotypes, and distinguished between GD patients with normal and pathologic DXA scores. PCA and SVM predictive analyses discriminated between GD and HC with maximum accuracy of 73% and area under ROC curve of 0.79. Trabecular STM differences can be quantified between GD patients and HC, and GD sub-types using micro-MRI and machine learning based analytics. Work is underway to expand this approach to evaluate GD disease burden and treatment efficacy. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Using Anisotropic 3D Minkowski Functionals for Trabecular Bone Characterization and Biomechanical Strength Prediction in Proximal Femur Specimens

    Science.gov (United States)

    Nagarajan, Mahesh B.; De, Titas; Lochmüller, Eva-Maria; Eckstein, Felix; Wismüller, Axel

    2017-01-01

    The ability of Anisotropic Minkowski Functionals (AMFs) to capture local anisotropy while evaluating topological properties of the underlying gray-level structures has been previously demonstrated. We evaluate the ability of this approach to characterize local structure properties of trabecular bone micro-architecture in ex vivo proximal femur specimens, as visualized on multi-detector CT, for purposes of biomechanical bone strength prediction. To this end, volumetric AMFs were computed locally for each voxel of volumes of interest (VOI) extracted from the femoral head of 146 specimens. The local anisotropy captured by such AMFs was quantified using a fractional anisotropy measure; the magnitude and direction of anisotropy at every pixel was stored in histograms that served as a feature vectors that characterized the VOIs. A linear multi-regression analysis algorithm was used to predict the failure load (FL) from the feature sets; the predicted FL was compared to the true FL determined through biomechanical testing. The prediction performance was measured by the root mean square error (RMSE) for each feature set. The best prediction performance was obtained from the fractional anisotropy histogram of AMF Euler Characteristic (RMSE = 1.01 ± 0.13), which was significantly better than MDCT-derived mean BMD (RMSE = 1.12 ± 0.16, p<0.05). We conclude that such anisotropic Minkowski Functionals can capture valuable information regarding regional trabecular bone quality and contribute to improved bone strength prediction, which is important for improving the clinical assessment of osteoporotic fracture risk. PMID:29170581

  7. Assessment of bone mineral density by DXA and the trabecular microarchitecture of the calcaneum by texture analysis in pre- and postmenopausal women in the evaluation of osteoporosis

    Directory of Open Access Journals (Sweden)

    Karunanithi R

    2007-01-01

    Full Text Available The in vivo evaluation of trabecular bone structure could be useful in the diagnosis of osteoporosis for the characterization of therapeutic response and understanding the role of parameters other than bone mineral density (BMD in defining skeletal status. This study was made to evaluate changes taking place in the trabecular architecture of bone with age and menopausal status in women. The findings are compared with the femoral neck bone as well as the trochantar bone mineral density determined by dual energy X-ray absorptiometry (DXA, which is a standard reference test for evaluation of osteoporosis. Seventy females were recruited for the study, 25 pre-menopausal (mean age ± SD: 39.4 ± 3.8 and 45 postmenopausal (mean age ± SD: 57.9 ± 7.9 women. The right femoral neck bone mineral density was measured for them by dual energy X-ray absorptiometry (DXA. For the same individuals, lateral view radiographs of the right calcaneum were taken as well. The radiographs were digitized and the region of interest (ROI of 256 x 256 pixels was selected, the run-length matrix was computed for calculating seven parameters [Table 1] and the two-dimensional fast Fourier transform of the image was calculated. Using the FFT, the power spectral density (PSD was derived and the root mean square (RMS value was determined. Our results confirm that age has a significant influence on the texture of the trabecular bone and bone mineral density.

  8. Preliminary result on trabecular bone score (TBS in lumbar vertebrae with experimentally altered microarchitecture

    Directory of Open Access Journals (Sweden)

    M. Di Stefano

    2013-01-01

    Full Text Available The aim of this preliminary research is to investigate the reliability of a new qualitative parameter, called Trabecular Bone Score (TBS, recently proposed for evaluating the microarchitectural arrangement of cancellous bone in scans carried out by dual energy X-ray absorptiometry (DXA. Vertebral bodies of 15 fresh samples of lumbar spines of adult pig were analysed either in basal conditions and with altered microarchitecture of the cancellous bone obtained by progressive drilling. The examined bony areas do not show changes in bone mineral density (BMD, whereas TBS values decrease with the increasing alteration of the vertebral microtrabecular structure. Our preliminary data seem to confirm the reliability of TBS as a qualitative parameter useful for evaluating the microarchitectural strength in bony areas quantitatively analysed by DXA.

  9. New bone formation and trabecular bone microarchitecture of highly porous tantalum compared to titanium implant threads: A pilot canine study.

    Science.gov (United States)

    Lee, Jin Whan; Wen, Hai Bo; Gubbi, Prabhu; Romanos, Georgios E

    2018-02-01

    This study evaluated new bone formation activities and trabecular bone microarchitecture within the highly porous region of Trabecular Metal™ Dental Implants (TM) and between the threads of Tapered Screw-Vent® Dental Implants (TSV) in fresh canine extraction sockets. Eight partially edentulated dogs received four implants (4.1 mmD × 13 mmL) bilaterally in mandibular fresh extraction sockets (32 TM, 32 TSV implants), and allowed to heal for 2, 4, 8, and 12 weeks. Calcein was administered to label mineralizing bone at 11 and 4 days before euthanasia for dogs undergoing all four healing periods. Biopsies taken at each time interval were examined histologically. Histomorphometric assay was conducted for 64 unstained and 64 stained slides at the region of interest (ROI) (6 mm long × 0.35 mm deep) in the midsections of the implants. Topographical and chemical analyses were also performed. Histomorphometry revealed significantly more new bone in the TM than in the TSV implants at each healing time (p = .0014, .0084, .0218, and .0251). Calcein-labeled data showed more newly mineralized bone in the TM group than in the TSV group at 2, 8, and 12 weeks (p = .045, .028, .002, respectively) but not at 4 weeks (p = .081). Histologically TM implants exhibited more bone growth and dominant new immature woven bone at an earlier time point than TSV implants. The parameters representing trabecular bone microarchitecture corroborated faster new bone formation in the TM implants when compared to the TSV implants. TM exhibited an irregular faceted topography compared to a relatively uniform microtextured surface for TSV. Chemical analysis showed peaks associated with each implant's composition material, and TSV also showed peaks reflecting the elements of the calcium phosphate blasting media. Results suggest that the healing pathway associated with the highly porous midsection of TM dental implant could enable faster and stronger secondary implant stability than

  10. Fermented dairy products consumption is associated with attenuated cortical bone loss independently of total calcium, protein, and energy intakes in healthy postmenopausal women.

    Science.gov (United States)

    Biver, E; Durosier-Izart, C; Merminod, F; Chevalley, T; van Rietbergen, B; Ferrari, S L; Rizzoli, R

    2018-05-03

    A longitudinal analysis of bone microstructure in postmenopausal women of the Geneva Retirees Cohort indicates that age-related cortical bone loss is attenuated at non-bearing bone sites in fermented dairy products consumers, not in milk or ripened cheese consumers, independently of total energy, calcium, or protein intakes. Fermented dairy products (FDP), including yogurts, provide calcium, phosphorus, and proteins together with prebiotics and probiotics, all being potentially beneficial for bone. In this prospective cohort study, we investigated whether FDP, milk, or ripened cheese consumptions influence age-related changes of bone mineral density (BMD) and microstructure. Dietary intakes were assessed at baseline and after 3.0 ± 0.5 years with a food frequency questionnaire in 482 postmenopausal women enrolled in the Geneva Retirees Cohort. Cortical (Ct) and trabecular (Tb) volumetric (v) BMD and microstructure at the distal radius and tibia were assessed by high-resolution peripheral quantitative computerized tomography, in addition to areal (a) BMD and body composition by dual-energy X-ray absorptiometry, at the same time points. At baseline, FDP consumers had lower abdominal fat mass and larger bone size at the radius and tibia. Parathyroid hormone and β-carboxyterminal cross-linked telopeptide of type I collagen levels were inversely correlated with FDP consumption. In the longitudinal analysis, FDP consumption (mean of the two assessments) was associated with attenuated loss of radius total vBMD and of Ct vBMD, area, and thickness. There was no difference in aBMD and at the tibia. These associations were independent of total energy, calcium, or protein intakes. For other dairy products categories, only milk consumption was associated with lower decrease of aBMD and of failure load at the radius. In this prospective cohort of healthy postmenopausal women, age-related Ct bone loss was attenuated at non-bearing bone sites in FDP consumers, not in milk

  11. Magnetic resonance imaging of trabecular and cortical bone in mice: comparison of high resolution in vivo and ex vivo MR images with corresponding histology

    International Nuclear Information System (INIS)

    Weber, Michael H.; Sharp, Jonathan C.; Latta, Peter; Sramek, Milos; Hassard, H. Thomas; Orr, F. William

    2005-01-01

    Measurements of bone morphometry and remodeling have been shown to reflect bone strength and can be used to diagnose degenerative bone disease. In this study, in vivo and ex vivo magnetic resonance imaging (MRI) techniques to assess trabecular and cortical bone properties have been compared to each other and to histology as a novel means for the quantification of bone. Femurs of C57Bl/6 mice were examined both in vivo and ex vivo on an 11.7 T MRI scanner, followed by histologic processing and morphometry. A thresholding analysis technique was applied to the MRI images to generate contour lines and to delineate the boundaries between bone and marrow. Using MRI, an optimal correlation with histology was obtained with an in vivo longitudinal sectioned short echo time gradient-echo versus an in vivo long echo time spin-echo sequence or an ex vivo pulse sequence. Gradient-echo images were acquired with a maximum in-plane resolution of 35 μm. Our results demonstrated that in both the in vivo and ex vivo data sets, the percent area of marrow increases and percent area of trabecular bone and cortical bone thickness decreases moving from the epiphyseal growth plate to the diaphysis. These changes, observed with MRI, correlate with the histological data. Investigations using in vivo MRI gradient-echo sequences consistently gave the best correlation with histology. Our quantitative evaluation using both ex vivo and in vivo MRI was found to be an effective means to visualize non-invasively the normal variation in trabecular and cortical bone as compared to a histological 'gold standard' The experiments validated in vivo MRI as a potential high resolution technique for investigating both soft tissue, such as marrow, and bone without radiation exposure

  12. Low volumetric BMD is linked to upper-limb fracture in pubertal girls and persists into adulthood: a seven-year cohort study.

    Science.gov (United States)

    Cheng, Sulin; Xu, Leiting; Nicholson, Patrick H F; Tylavsky, Frances; Lyytikäinen, Arja; Wang, Qingju; Suominen, Harri; Kujala, Urho M; Kröger, Heikki; Alen, Markku

    2009-09-01

    The aetiology of increased incidence of fracture during puberty is unclear. This study aimed to determine whether low volumetric bone mineral density (vBMD) in the distal radius is associated with upper-limb fractures in growing girls, and whether any such vBMD deficit persists into adulthood. Fracture history from birth to 20 years was obtained and verified by medical records in 1034 Finnish girls aged 10-13 years. Bone density and geometry at distal radius, biomarkers and lifestyle/behavioural factors were assessed in a subset of 396 girls with a 7.5-year follow-up. We found that fracture incidence peaked during puberty (relative risk 3.1 at age of 8-14 years compared to outside this age window), and 38% of fractures were in the upper-limb. Compared to the non-fracture cohort, girls who sustained upper-limb fracture at ages 8-14 years had lower distal radial vBMD at baseline (258.9+/-37.5 vs. 287.5+/-34.1 mg/cm(3), p=0.001), 1-year (252.0+/-29.3 vs. 282.6+/-33.5 mg/cm(3), p=0.001), 2-year (258.9+/-32.2 vs. 289.9+/-40.1 mg/cm(3), p=0.003), and 7-year follow-ups (early adulthood, 307.6+/-35.9 vs. 343.6+/-40.9 mg/cm(3), p=0.002). There was a consistent trend towards larger bone cross-sectional area in the fracture cohort compared to non-fracture. In a logistic regression model, lower vBMD (p=0.001) was the only significant predictor of upper-limb fracture during the period of 8-14 years. Our results indicate that low BMD is an important factor underlying elevated upper-limb fracture risk during puberty, and that low BMD in pubertal girls with fracture persists into adulthood. Hence low vBMD during childhood is not a transient deficit. Methods to monitor vBMD and to maximise bone mineral accrual and reduce risks of falling in childhood should be developed.

  13. Identification of a constitutive law for trabecular bone samples under remodeling in the framework of irreversible thermodynamics

    Science.gov (United States)

    Louna, Zineeddine; Goda, Ibrahim; Ganghoffer, Jean-François

    2018-01-01

    We construct in the present paper constitutive models for bone remodeling based on micromechanical analyses at the scale of a representative unit cell (RUC) including a porous trabecular microstructure. The time evolution of the microstructure is simulated as a surface remodeling process by relating the surface growth remodeling velocity to a surface driving force incorporating a (surface) Eshelby tensor. Adopting the framework of irreversible thermodynamics, a 2D constitutive model based on the setting up of the free energy density and a dissipation potential is identified from FE simulations performed over a unit cell representative of the trabecular architecture obtained from real bone microstructures. The static and evolutive effective properties of bone at the scale of the RUC are obtained by combining a methodology for the evaluation of the average kinematic and static variables over a prototype unit cell and numerical simulations with controlled imposed first gradient rates. The formulated effective growth constitutive law at the scale of the homogenized set of trabeculae within the RUC is of viscoplastic type and relates the average growth strain rate to the homogenized stress tensor. The postulated model includes a power law function of an effective stress chosen to depend on the first and second stress invariants. The model coefficients are calibrated from a set of virtual testing performed over the RUC subjected to a sequence of loadings. Numerical simulations show that overall bone growth does not show any growth kinematic hardening. The obtained results quantify the strength and importance of different types of external loads (uniaxial tension, simple shear, and biaxial loading) on the overall remodeling process and the development of elastic deformations within the RUC.

  14. Effects of glaucoma medications and preservatives on cultured human trabecular meshwork and non-pigmented ciliary epithelial cell lines.

    Science.gov (United States)

    Ammar, David A; Kahook, Malik Y

    2011-10-01

    We investigated the potential cytotoxicity of various topical ophthalmic glaucoma formulations containing different preservatives in cultured human trabecular meshwork (TM) and non-pigmented ciliary epithelial (NPCE) cell lines. We tested 0.004% travoprost preserved with either 0.015% benzalkonium chloride (BAK), sofZia or 0.001% Polyquad (PQ); and 0.005% latanoprost preserved with 0.020% BAK. We also tested a range of BAK concentrations in balanced salt solution (BSS). TM cells were treated for 10 min at 37°C with solutions diluted 1:10 to mimic the reduced penetration of topical preparations to the anterior chamber. Viability was determined by the uptake of the fluorescent vital dye calcein-AM (n = 6). BAK solutions (diluted 1:10) demonstrated a dose-dependent reduction in cell viability in both cell types (TM and NPCE). With a 1:10 dilution of 0.020% BAK, there were significantly more living NPCE cells (89 ± 6%) than TM cells (57 ± 6%; p < 0.001). In TM cells, travoprost + BAK had statistically fewer live cells (83 ± 5%) than both travoprost + sofZia (97 ± 5%) and travoprost + PQ (97 ± 6%; p < 0.05). Compared with BSS-treated NPCE cells, travoprost had statistically fewer live cells (p < 0.05) when preserved with BAK (85 ± 16%), sofZia (91 ± 6%) or PQ (94 ± 2%). These results demonstrate that substitution of BAK from topical ophthalmic drugs results in greater viability of cultured TM cells, the cells involved in the conventional outflow pathway. Cultured NPCE, responsible for aqueous inflow, appear more resilient to BAK.

  15. In vitro and in silico characterization of open-cell structures of trabecular bone.

    Science.gov (United States)

    Ramos-Infante, S J; Pérez, M A

    2017-11-01

    This work aimed to perform a detailed in vitro and in silico characterization of open-cell structures, which resemble trabecular bone, to elucidate osteoporosis failure mechanisms. Experimental and image-based computational methods were used to estimate Young's modulus and porosities of different open-cell structures (Sawbones; Malmö, Sweden). Three different open-cell structures with different porosities were characterized. Additionally, some open-cell structures were scanned using a microcomputed tomography system (μCT) to non-destructively predict specimen Young's modulus of the structures by developing voxel-based and tetrahedral finite element (FE) models. A 3D reconstruction and FE analyses were used. The experimental and computational results with different element types (linear and quadratic tetrahedrons and voxel-based meshes) were compared with Sawbones data (Sawbones; Malmö, Sweden) revealing important differences in Young's modulus and porosities. The specimens with high and low volume fractions were best represented by linear and quadratic tetrahedrons, respectively. These results could be used to develop new osteoporosis-prevention strategies.

  16. Laser Trabeculoplasty Induces Changes in the Trabecular Meshwork Glycoproteome: A pilot study

    Science.gov (United States)

    Amelinckx, Adriana; Castello, Maria; Arrieta-Quintero, Esdras; Lee, Tinthu; Salas, Nelson; Hernandez, Eleut; Lee, Richard K.; Bhattacharya, Sanjoy K.; Parel, Jean-Marie A

    2009-01-01

    Laser trabeculoplasty (LT) is a commonly used modality of treatment for glaucoma. The mechanism by which LT lowers the intraocular pressure (IOP) is unknown. Using cat eyes, selective laser trabeculoplasty (SLT) with a Q-switched frequency doubled Nd:YAG laser was used to treat the trabecular meshwork (TM). Laser treated TM was then subjected to proteomic analysis for detection of molecular changes and histological analysis for the detection of structural and protein expression patterns. In addition, the protein glycosylation patterns of laser treated and non-treated TM was assessed and differentially glycosylated proteins were proteomically identified. SLT laser treatment to the TM resulted in elevated glycosylation levels compared to non-lasered TM. TM laser treatment also resulted in protein expression levels changes of several proteins. Elevated levels of biglycan, keratocan and prolargin were detected in laser treated TM compared to non-lasered controls. Further investigation is anticipated to provide insight into how glycosylation changes affect TM proteins and TM regulation of aqueous outflow in response to laser trabeculoplasty. PMID:19432485

  17. Comparison of the relationship between bone marrow adipose tissue and volumetric bone mineral density in children and adults.

    Science.gov (United States)

    Shen, Wei; Velasquez, Gilbert; Chen, Jun; Jin, Ye; Heymsfield, Steven B; Gallagher, Dympna; Pi-Sunyer, F Xavier

    2014-01-01

    Several large-scale studies have reported the presence of an inverse relationship between bone mineral density (BMD) and bone marrow adipose tissue (BMAT) in adults. We aim to determine if there is an inverse relationship between pelvic volumetric BMD (vBMD) and pelvic BMAT in children and to compare this relationship in children and adults. Pelvic BMAT and bone volume (BV) was evaluated in 181 healthy children (5-17yr) and 495 healthy adults (≥18yr) with whole-body magnetic resonance imaging (MRI). Pelvic vBMD was calculated using whole-body dual-energy X-ray absorptiometry to measure pelvic bone mineral content and MRI-measured BV. An inverse correlation was found between pelvic BMAT and pelvic vBMD in both children (r=-0.374, pBMAT as the independent variable, being a child or adult neither significantly contribute to the pelvic BMD (p=0.995) nor did its interaction with pelvic BMAT (p=0.415). The inverse relationship observed between pelvic vBMD and pelvic BMAT in children extends previous findings that found the inverse relationship to exist in adults and provides further support for a reciprocal relationship between adipocytes and osteoblasts. Copyright © 2014 The International Society for Clinical Densitometry. Published by Elsevier Inc. All rights reserved.

  18. Trabecular bone mineral density measured by quantitative CT of the lumbar spine in children and adolescents: reference values and peak bone mass; Trabekulaere Knochendichte der Lendenwirbelsaeule bei Kindern und Jugendlichen in der quantitativen CT: Referenzwerte und Peak Bone Mass

    Energy Technology Data Exchange (ETDEWEB)

    Berthold, L.D.; Alzen, G. [Kinderradiologie, Zentrum fuer Radiologie, Universitaetsklinikum Giessen und Marburg GmbH, Standort Giessen (Germany); Haras, G. [Siemens AG, Medical Solutions, Forchheim (Germany); Mann, M. [AG Medizinische Statistik, Universitaetsklinikum Giessen und Marburg GmbH, Standort Giessen (Germany)

    2006-12-15

    Purpose: The aim of this study was to assess bone density values in the trabecular substance of the lumbar vertebral column in children and young adults in Germany from infancy to the age of peak bone mass. Materials and Methods: We performed quantiative computed tomography (QCT) on the first lumbar vertebra in 28 children and adolescents without diseases that may influence bone metabolism (15 boys, 13 girls, mean ages 11 and 8 years, respectively). We also measured 17 healthy young adults (9 men, 8 women, mean ages 20 and 21 years). We used a Somatom Balance Scanner (Siemens, Erlangen) and the Siemens Osteo software. Scan parameters: Slice thickness 1 cm, 80 kV, 81 or 114 mAs. We measured the trabecular bone density and the area and height of the vertebra and calculated the volume and content of calcium hydroxyapatite (Ca-HA) in the trabecular substance of the first lumbar vertebra. Results: Prepubertal boys had a mean bone density of 148.5 (median [med] 150.1, standard deviation [SD] 15.4) mg/Ca-HA per ml bone, and prepubertal girls had a mean density of 149.5 (med 150.8, SD 23.5) mg/ml. We did not observe a difference between prepubertal boys and girls. After puberty there was a significant difference (p<0.001) between males and females: Mean density (male) 158.0, med 162.5, SD 24.0 mg/ml, mean density (female) 191.2, med 191.3, SD 17.7 mg/ml. The Ca-HA content in the trabecular bone of the first lumbar vertebra was 1.1 (med 1.1, SD 0.5) g for prepubertal boys and 1.1 (0.9, 0.4) g for prepubertal girls. For post-pubertal males, the mean Ca-HA content was 3.5 g, med 3.5 SD 0.5 g, and for post-pubertal females, the mean content was 2.8, med 2.7, SD 0.4 g. Conclusion: The normal trabecular bone mineral density is 150 mg/ml with a standard deviation of 20 mg/ml independent of age or gender until the beginning of puberty. Peak bone mass (bone mineral content) in the trabecular substance of the lumbar vertebral column is higher in males than in females, and peak bone

  19. The combination of structural parameters and areal bone mineral density improves relation to proximal femur strength. An in vitro study with high resolution peripheral quantitative computed tomography

    DEFF Research Database (Denmark)

    Hansen, Stinus; Beck Nielsen, Jens-Erik; Ahrberg, Fabian

    2011-01-01

    , volumetric BMD (vBMD), and microarchitectural parameters were obtained. In addition, aBMD by dual-energy X-ray absorptiometry (DXA) was performed at conventional hip regions and maximal compressive strength (MCS) was determined in a side-impact biomechanical test. Twelve cervical and 19 trochanteric...... fractures were confirmed. Geometry, vBMD, microarchitecture, and aBMD correlated significantly with MCS, with Spearman's correlation coefficients up to 0.77, 0.89, 0.90, and 0.85 (P ...

  20. Use of dual energy X-ray absorptiometry, the trabecular bone score and quantitative computed tomography in the evaluation of chronic kidney disease-mineral and bone disorders.

    Science.gov (United States)

    Pocock, Nicholas

    2017-03-01

    In subjects with chronic kidney disease (CKD) who suffer a minimal trauma fracture, the problem is to differentiate between osteoporosis and the various forms of renal bone disease associated with CKD-mineral and bone disorder. This problem is exacerbated by the fact that renal osteodystrophy may coexist with osteoporosis. The World Health Organization's bone mineral density (BMD) criteria for osteopenia ( -2.5 < T-score < -1.0) and osteoporosis (a T-score ≤ -2.5) may be used in patients with CKD stages 1-3. In CKD stages 4-5, BMD by dual-energy X-ray absorptiometry (DXA) is less predictive and may underestimate fracture risk. The development of absolute fracture risk (AFR) algorithms, such as FRAX® and the Garvan absolute fracture risk calculator, to predict risk of fracture over a given time (usually 10 years) aims to incorporate non-BMD risk factors into the clinical assessment. FRAX® has been shown to be useful to assess fracture risk in CKD but may underestimate fracture risk in advanced CKD. The trabecular bone score is a measure of grey scale homogeneity obtained from spine DXA, which correlates to trabecular microarchitecture and is an independent risk factor for fracture. Recent data demonstrate the potential utility of the trabecular bone score adjustment of AFR through the FRAX® algorithm in subjects with CKD. Parameters of bone microarchitecture using peripheral quantitative computed tomography (pQCT) or high-resolution pQCT are also able to discriminate fracture status in subjects with CKD. However, there are at present no convincing data that the addition of pQCT or high-resolution pQCT parameters to DXA BMD improves fracture discrimination. More advanced estimates of bone strength derived from measurements of micro-architecture, by QCT-derived finite element analysis may be incorporated into AFR algorithms in the future. © 2017 Asian Pacific Society of Nephrology.

  1. The combined effects of soya isoflavones and resistant starch on equol production and trabecular bone loss in ovariectomised mice.

    Science.gov (United States)

    Tousen, Yuko; Matsumoto, Yu; Matsumoto, Chiho; Nishide, Yoriko; Nagahata, Yuya; Kobayashi, Isao; Ishimi, Yoshiko

    2016-07-01

    Equol is a metabolite of the soya isoflavone (ISO) daidzein that is produced by intestinal microbiota. Equol has greater oestrogenic activity compared with other ISO, and it prevents bone loss in postmenopausal women. Resistant starch (RS), which has a prebiotic activity and is a dietary fibre, was reported to promote equol production. Conversely, the intestinal microbiota is reported to directly regulate bone health by reducing inflammatory cytokine levels and T-lymphocytes in bone. The present study evaluated the combined effects of diet supplemented with ISO and RS on intestinal microbiota, equol production, bone mineral density (BMD) and inflammatory gene expression in the bone marrow of ovariectomised (OVX) mice. Female ddY strain mice, aged 8 weeks, were either sham-operated (Sham, n 7) or OVX. OVX mice were randomly divided into the following four groups (seven per group): OVX control (OVX); OVX fed 0·05 % ISO diet (OVX+ISO); OVX fed 9 % RS diet (OVX+RS); and OVX fed 0·05 % ISO- and 9 % RS diet (OVX+ISO+RS). After 6 weeks, treatment with the combination of ISO and RS increased equol production, prevented the OVX-induced decline in trabecular BMD in the distal femur by modulating the enteric environment and altered OVX-induced inflammation-related gene expression in the bone marrow. However, there were no significant differences in bone parameters between the ISO+RS and ISO-alone groups in OVX mice. Our findings suggest that the combination of ISO and RS might alter intestinal microbiota and immune status in the bone marrow, resulting in attenuated bone resorption in OVX mice.

  2. Monte Carlo simulation of age-dependent radiation dose from alpha- and beta-emitting radionuclides to critical trabecular bone and bone marrow targets

    Science.gov (United States)

    Dant, James T.; Richardson, Richard B.; Nie, Linda H.

    2013-05-01

    Alpha (α) particles and low-energy beta (β) particles present minimal risk for external exposure. While these particles can induce leukemia and bone cancer due to internal exposure, they can also be beneficial for targeted radiation therapies. In this paper, a trabecular bone model is presented to investigate the radiation dose from bone- and marrow-seeking α and β emitters to different critical compartments (targets) of trabecular bone for different age groups. Two main issues are addressed with Monte Carlo simulations. The first is the absorption fractions (AFs) from bone and marrow to critical targets within the bone for different age groups. The other issue is the application of 223Ra for the radiotherapy treatment of bone metastases. Both a static model and a simulated bone remodeling process are established for trabecular bone. The results show significantly lower AFs from radionuclide sources in the bone volume to the peripheral marrow and the haematopoietic marrow for adults than for newborns and children. The AFs from sources on the bone surface and in the bone marrow to peripheral marrow and haematopoietic marrow also varies for adults and children depending on the energy of the particles. Regarding the use of 223Ra as a radionuclide for the radiotherapy of bone metastases, the simulations show a significantly higher dose from 223Ra and its progeny in forming bone to the target compartment of bone metastases than that from two other more commonly used β-emitting radiopharmaceuticals, 153Sm and 89Sr. There is also a slightly lower dose from 223Ra in forming bone to haematopoietic marrow than that from 153Sm and 89Sr. These results indicate a higher therapy efficiency and lower marrow toxicity from 223Ra and its progeny. In conclusion, age-related changes in bone dimension and cellularity seem to significantly affect the internal dose from α and β emitters in the bone and marrow to critical targets, and 223Ra may be a more efficient

  3. 3D porous architecture of stacks of β-TCP granules compared with that of trabecular bone: a microCT, vector analysis and compression study

    Directory of Open Access Journals (Sweden)

    Daniel eCHAPPARD

    2015-10-01

    Full Text Available The 3D arrangement of porous granular biomaterials usable to fill bone defects has received little study. Granular biomaterials occupy 3D space when packed together in a manner that creates a porosity suitable for the invasion of vascular and bone cells. Granules of β-TCP were prepared with either 12.5 or 25g of β-TCP powder in the same volume of slurry. When the granules were placed in a test tube, this produced 3D stacks with a high (HP or low porosity (LP, respectively. Stacks of granules mimic the filling of a bone defect by a surgeon. The aim of this study was to compare the porosity of stacks of β-TCP granules with that of cores of trabecular bone. Biomechanical compression tests were done on the granules stacks. Bone cylinders were prepared from calf tibia plateau, constituted high density (HD blocks. Low density (LD blocks were harvested from aged cadaver tibias. Microcomputed tomography was used on the β-TCP granule stacks and the trabecular bone cores to determine porosity and specific surface. A vector projection algorithm was used to image porosity employing a frontal plane image which was constructed line by line from all images of a microCT stack. Stacks of HP granules had porosity (75.3 ± 0.4% and fractal lacunarity (0.043 ± 0.007 intermediate between that of HD (resp. 69.1 ± 6.4%, p<0.05 and 0.087 ± 0.045, p<0.05 and LD bones (resp. 88.8 ± 1.57% and 0.037 ± 0.014 but exhibited a higher surface density (5.56 ± 0.11 mm2/mm3 vs. 2.06 ± 0.26 for LD, p<0.05. LP granular arrangements created large pores coexisting with dense areas of material. Frontal plane analysis evidenced a more regular arrangement of β-TCP granules than bone trabeculae. Stacks of HP granules represent a scaffold that resembles trabecular bone in its porous microarchitecture.

  4. Recreational football training decreases risk factors for bone fractures in untrained premenopausal women

    DEFF Research Database (Denmark)

    Helge, E W; Aagaard, P; Jakobsen, M D

    2010-01-01

    untrained Danish premenopausal women were randomized into two training groups (F and R) that trained 1.8+/-0.3 (+/-SD) and 1.9+/-0.3 h/week, respectively, and these groups were compared with an inactive control group (C). Jumping and dynamic muscle strength were tested and tibial vBMD was measured using...... peripheral quantitative computed tomography. Total vBMD in left and right tibia increased by 2.6+/-2.3% and 2.1+/-1.8% (P

  5. Trabecular meshwork ECM remodeling in glaucoma: could RAS be a target?

    Science.gov (United States)

    Agarwal, Puneet; Agarwal, Renu

    2018-06-14

    Disturbances of extracellular matrix (ECM) homeostasis in trabecular meshwork (TM) cause increased aqueous outflow resistance leading to elevated intraocular pressure (IOP) in glaucomatous eyes. Therefore, restoration of ECM homeostasis is a rational approach to prevent disease progression. Since renin-angiotensin system (RAS) inhibition positively alters ECM homeostasis in cardiovascular pathologies involving pressure and volume overload, it is likely that RAS inhibitors reduce IOP primarily by restoring ECM homeostasis. Areas covered: Current evidence showing the presence of RAS components in ocular tissue and its role in regulating aqueous humor dynamics is briefly summarized. The role of RAS in ECM remodeling is discussed both in terms of its effects on ECM synthesis and its breakdown. The mechanisms of ECM remodeling involving interactions of RAS with transforming growth factor-β, Wnt/β-catenin signaling, bone morphogenic proteins, connective tissue growth factor, and matrix metalloproteinases in ocular tissue are discussed. Expert opinion: Current literature strongly indicates a significant role of RAS in ECM remodeling in TM of hypertensive eyes. Hence, IOP-lowering effect of RAS inhibitors may primarily be attributed to restoration of ECM homeostasis in aqueous outflow pathways rather than its vascular effects. However, the mechanistic targets for RAS inhibitors have much wider distribution and consequences, which remain relatively unexplored in TM.

  6. Dietary acid load, trabecular bone integrity, and mineral density in an ageing population: the Rotterdam study.

    Science.gov (United States)

    de Jonge, E A L; Koromani, F; Hofman, A; Uitterlinden, A G; Franco, O H; Rivadeneira, F; Kiefte-de Jong, J C

    2017-08-01

    We studied the relation between a diet that is high in acid-forming nutrients (e.g. proteins) and low in base-forming nutrients (e.g. potassium) and bone structure. We showed a negative relation, which was more prominent if proteins were of animal rather than of vegetable origin and if intake of dietary fibre was high. Studies on dietary acid load (DAL) and fractures have shown inconsistent results. Associations between DAL, bone mineral density (BMD) and trabecular bone integrity might play a role in these inconsistencies and might be influenced by renal function and dietary fibre intake. Therefore, our aim was to study (1) associations of DAL with BMD and with the trabecular bone score (TBS) and (2) the potential influence of renal function and dietary fibre in these associations. Dutch individuals aged 45 years and over (n = 4672) participating in the prospective cohort of the Rotterdam study were included. Based on food frequency questionnaires, three indices of DAL were calculated: the net endogenous acid production (NEAP) and the ratios of vegetable or animal protein and potassium (VegPro/K and AnPro/K). Data on lumbar spinal TBS and BMD were derived from dual-energy X-ray absorptiometry measurements. Independent of confounders, NEAP and AnPro/K, but not VegPro/K, were associated with low TBS (standardized β (95%) = -0.04 (-0.07, -0.01) and -0.08 (-0.11, -0.04)) but not with BMD. Associations of AnPro/K and VegPro/K with TBS were non-linear and differently shaped. Unfavourable associations between NEAP, BMD and TBS were mainly present in subgroups with high fibre intake. High NEAP was associated with low TBS. Associations of AnPro/K and VegPro/K and TBS were non-linear and differently shaped. No significant associations of DAL with BMD were observed, nor was there any significant interaction between DAL and renal function. Mainly in participants with high intake of dietary fibre, DAL might be detrimental to bone.

  7. Three-dimensional quantification of structures in trabecular bone using measures of complexity

    DEFF Research Database (Denmark)

    Marwan, Norbert; Kurths, Jürgen; Thomsen, Jesper Skovhus

    2009-01-01

    The study of pathological changes of bone is an important task in diagnostic procedures of patients with metabolic bone diseases such as osteoporosis as well as in monitoring the health state of astronauts during long-term space flights. The recent availability of high-resolution three-dimensiona......The study of pathological changes of bone is an important task in diagnostic procedures of patients with metabolic bone diseases such as osteoporosis as well as in monitoring the health state of astronauts during long-term space flights. The recent availability of high-resolution three......-dimensional (3D) imaging of bone challenges the development of data analysis techniques able to assess changes of the 3D microarchitecture of trabecular bone. We introduce an approach based on spatial geometrical properties and define structural measures of complexity for 3D image analysis. These measures...... evaluate different aspects of organization and complexity of 3D structures, such as complexity of its surface or shape variability. We apply these measures to 3D data acquired by high-resolution microcomputed tomography (µCT) from human proximal tibiae and lumbar vertebrae at different stages...

  8. Bone ingrowth potential of electron beam and selective laser melting produced trabecular-like implant surfaces with and without a biomimetic coating.

    Science.gov (United States)

    Biemond, J E; Hannink, G; Verdonschot, N; Buma, P

    2013-03-01

    The bone ingrowth potential of trabecular-like implant surfaces produced by either selective laser melting (SLM) or electron beam melting (EBM), with or without a biomimetic calciumphosphate coating, was examined in goats. For histological analysis and histomorphometry of bone ingrowth depth and bone implant contact specimens were implanted in the femoral condyle of goats. For mechanical push out tests to analyse mechanical implant fixation specimens were implanted in the iliac crest. The follow up periods were 4 (7 goats) and 15 weeks (7 goats). Both the SLM and EBM produced trabecular-like structures showed a variable bone ingrowth after 4 weeks. After 15 weeks good bone ingrowth was found in both implant types. Irrespective to the follow up period, and the presence of a coating, no histological differences in tissue reaction around SLM and EBM produced specimens was found. Histological no coating was detected at 4 and 15 weeks follow up. At both follow up periods the mechanical push out strength at the bone implant interface was significantly lower for the coated SLM specimens compared to the uncoated SLM specimens. The expected better ingrowth characteristics and mechanical fixation strength induced by the coating were not found. The lower mechanical strength of the coated specimens produced by SLM is a remarkable result, which might be influenced by the gross morphology of the specimens or the coating characteristics, indicating that further research is necessary.

  9. Freeze-thaw decellularization of the trabecular meshwork in an ex vivo eye perfusion model

    Directory of Open Access Journals (Sweden)

    Yalong Dang

    2017-08-01

    Full Text Available Objective The trabecular meshwork (TM is the primary substrate of outflow resistance in glaucomatous eyes. Repopulating diseased TM with fresh, functional TM cells might be a viable therapeutic approach. Decellularized TM scaffolds have previously been produced by ablating cells with suicide gene therapy or saponin, which risks incomplete cell removal or dissolution of the extracellular matrix, respectively. We hypothesized that improved trabecular meshwork cell ablation would result from freeze-thaw cycles compared to chemical treatment. Materials and Methods We obtained 24 porcine eyes from a local abattoir, dissected and mounted them in an anterior segment perfusion within two hours of sacrifice. Intraocular pressure (IOP was recorded continuously by a pressure transducer system. After 72 h of IOP stabilization, eight eyes were assigned to freeze-thaw (F ablation (−80 °C × 2, to 0.02% saponin (S treatment, or the control group (C, respectively. The TM was transduced with an eGFP expressing feline immunodeficiency viral (FIV vector and tracked via fluorescent microscopy to confirm ablation. Following treatment, the eyes were perfused with standard tissue culture media for 180 h. TM histology was assessed by hematoxylin and eosin staining. TM viability was evaluated by a calcein AM/propidium iodide (PI assay. The TM extracellular matrix was stained with Picro Sirius Red. We measured IOP and modeled it with a linear mixed effects model using a B-spline function of time with five degrees of freedom. Results F and S experienced a similar IOP reduction of 30% from baseline (P = 0.64. IOP reduction of about 30% occurred in F within 24 h and in S within 48 h. Live visualization of eGFP demonstrated that F conferred a complete ablation of all TM cells and only a partial ablation in S. Histological analysis and Picro Sirius staining confirmed that no TM cells survived in F while the extracellular matrix remained. The viability assay showed

  10. Prenatal nutritional manipulation by in ovo enrichment influences bone structure, composition, and mechanical properties.

    Science.gov (United States)

    Yair, R; Shahar, R; Uni, Z

    2013-06-01

    The objective of this study was to examine the effect of embryonic nutritional enrichment on the development and properties of broiler leg bones (tibia and femur) from the prenatal period until maturity. To accomplish the objective, 300 eggs were divided into 2 groups: a noninjected group (control) and a group injected in ovo with a solution containing minerals, vitamins, and carbohydrates (enriched). Tibia and femur from both legs were harvested from chicks on embryonic days 19 (E19) and 21 (E21) and d 3, 7, 14, 28, and 54 posthatch (n = 8). The bones were mechanically tested (stiffness, maximal load, and work to fracture) and scanned in a micro-computed tomography (μCT) scanner to examine the structural properties of the cortical [cortical area, medullary area, cortical thickness, and maximal moment of inertia (Imax)] and trabecular (bone volume percent, trabecular thickness, and trabecular number) areas. To examine bone mineralization, bone mineral density (BMD) of the cortical area was obtained from the μCT scans, and bones were analyzed for the ash and mineral content. The results showed improved mechanical properties of the enriched group between E19 and d 3 and on d 14 (P bones), greater femoral cortical area on d 3, and greater Imax of both bones on d 14 (P bone trabecular architecture were that the enriched group had greater bone volume percent and trabecular thickness in the tibia on d 7 and the femur on d 28 (P mineralization between E19 and d 54 showed improved mineralization in the enriched group on E19 whereas on d 3 and 7, the control group showed a mineralization advantage, and on d 28 and 54, the enriched group showed again greater mineralization (P bone properties pre- and postnatally and showed that avian embryos are a good model for studying the effect of embryonic nutrition on natal and postnatal development. Most importantly, the enrichment led to improved mechanical properties until d 14 (roughly third of the lifespan of the bird), a big

  11. Assessment of circumferential angle-closure by the iris-trabecular contact index with swept-source optical coherence tomography.

    Science.gov (United States)

    Baskaran, Mani; Ho, Sue-Wei; Tun, Tin A; How, Alicia C; Perera, Shamira A; Friedman, David S; Aung, Tin

    2013-11-01

    To evaluate the diagnostic performance of the iris-trabecular contact (ITC) index, a measure of the degree of angle-closure, using swept-source optical coherence tomography (SSOCT, CASIA SS-1000, Tomey Corporation, Nagoya, Japan) in comparison with gonioscopy. Prospective observational study. A total of 108 normal subjects and 32 subjects with angle-closure. The SSOCT 3-dimensional angle scans, which obtain radial scans for the entire circumference of the angle, were performed under dark conditions and analyzed using customized software by a single examiner masked to the subjects' clinical details. The ITC index was calculated as a percentage of the angle that was closed on SSOCT images. First-order agreement coefficient (AC1) statistics and area under the receiver operating characteristic curve (AUC) analyses were performed for angle-closure on the basis of the ITC index in comparison with gonioscopy. Angle-closure on gonioscopy was defined as nonvisibility of posterior trabecular meshwork for at least 2 quadrants. Agreement of the ITC index with gonioscopically defined angle-closure was assessed using the AC1 statistic. Study subjects were predominantly Chinese (95.7%) and female (70.7%), with a mean age of 59.2 (standard deviation, 8.9) years. The median ITC index was 15.24% for gonioscopically open-angle eyes (n = 108) and 48.5% for closed-angle eyes (n = 32) (P = 0.0001). The agreement for angle-closure based on ITC index cutoffs (>35% and ≥50%) and gonioscopic angle-closure was 0.699 and 0.718, respectively. The AUC for angle-closure detection using the ITC index was 0.83 (95% confidence interval, 0.76-0.89), with an ITC index >35% having a sensitivity of 71.9% and specificity of 84.3%. The ITC index is a summary measure of the circumferential extent of angle-closure as imaged with SSOCT. The index had moderate agreement and good diagnostic performance for angle-closure with gonioscopy as the reference standard. Copyright © 2013 American Academy of

  12. Increased trabecular bone and improved biomechanics in an osteocalcin-null rat model created by CRISPR/Cas9 technology

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    Laura J. Lambert

    2016-10-01

    Full Text Available Osteocalcin, also known as bone γ-carboxyglutamate protein (Bglap, is expressed by osteoblasts and is commonly used as a clinical marker of bone turnover. A mouse model of osteocalcin deficiency has implicated osteocalcin as a mediator of changes to the skeleton, endocrine system, reproductive organs and central nervous system. However, differences between mouse and human osteocalcin at both the genome and protein levels have challenged the validity of extrapolating findings from the osteocalcin-deficient mouse model to human disease. The rat osteocalcin (Bglap gene locus shares greater synteny with that of humans. To further examine the role of osteocalcin in disease, we created a rat model with complete loss of osteocalcin using the CRISPR/Cas9 system. Rat osteocalcin was modified by injection of CRISPR/Cas9 mRNA into the pronuclei of fertilized single cell Sprague-Dawley embryos, and animals were bred to homozygosity and compound heterozygosity for the mutant alleles. Dual-energy X-ray absorptiometry (DXA, glucose tolerance testing (GTT, insulin tolerance testing (ITT, microcomputed tomography (µCT, and a three-point break biomechanical assay were performed on the excised femurs at 5 months of age. Complete loss of osteocalcin resulted in bones with significantly increased trabecular thickness, density and volume. Cortical bone volume and density were not increased in null animals. The bones had improved functional quality as evidenced by an increase in failure load during the biomechanical stress assay. Differences in glucose homeostasis were observed between groups, but there were no differences in body weight or composition. This rat model of complete loss of osteocalcin provides a platform for further understanding the role of osteocalcin in disease, and it is a novel model of increased bone formation with potential utility in osteoporosis and osteoarthritis research.

  13. Large-angle coherent/Compton scattering method for measurement in vitro of trabecular bone mineral concentration

    International Nuclear Information System (INIS)

    Gigante, G.E.; Sciuti, S.

    1985-01-01

    In this paper, experiments and related theoretical deductions on coherent/Compton scattering of 59.5-keV Am241 gamma line by bonelike materials are described. In particular, the authors demonstrate that a photon scattering mineralometer (PSM) can attain the best working conditions when it operates in a backscattering geometry mode. In fact, the large scattering angle they chose, theta = 135 degrees, allowed them to assemble a very compact source-detector device. Further, the relative sensitivity at 135 degrees turns out to be congruent to 1.7 and congruent to 6 times bigger than at 90 degrees and 45 degrees, respectively. The performances of the theta = 135 degrees PSM were experimentally investigated; i.e., in a measuring time of 10(3) s, a congruent to 5% statistical precision for bonelike materials, such as K 2 HPO 4 -water solutions, was obtained. The large-angle PSM device seems to be very promising for trabecular bone mineral density measurements in vivo in peripheral anatomic sites

  14. Clopidogrel (Plavix®), a P2Y(12) receptor antagonist, inhibits bone cell function in vitro and decreases trabecular bone in vivo

    DEFF Research Database (Denmark)

    Syberg, Susanne; Brandao-Burch, Andrea; Patel, Jessal J

    2012-01-01

    Clopidogrel (Plavix®), a selective P2Y(12) receptor antagonist, is widely prescribed to reduce the risk of heart attack and stroke and acts via the inhibition of platelet aggregation. Accumulating evidence now suggests that extracellular nucleotides, signalling through P2 receptors, play...... a significant role in bone, modulating both osteoblast and osteoclast function. In this study, we investigated the effects of clopidogrel treatment on (1) bone cell formation, differentiation and activity in vitro; and, (2) trabecular and cortical bone parameters in vivo. P2Y(12) receptor expression...

  15. Connective Tissue Growth Factor reporter mice label a subpopulation of mesenchymal progenitor cells that reside in the trabecular bone region.

    Science.gov (United States)

    Wang, Wen; Strecker, Sara; Liu, Yaling; Wang, Liping; Assanah, Fayekah; Smith, Spenser; Maye, Peter

    2015-02-01

    Few gene markers selectively identify mesenchymal progenitor cells inside the bone marrow. We have investigated a cell population located in the mouse bone marrow labeled by Connective Tissue Growth Factor reporter expression (CTGF-EGFP). Bone marrow flushed from CTGF reporter mice yielded an EGFP+ stromal cell population. Interestingly, the percentage of stromal cells retaining CTGF reporter expression decreased with age in vivo and was half the frequency in females compared to males. In culture, CTGF reporter expression and endogenous CTGF expression marked the same cell types as those labeled using Twist2-Cre and Osterix-Cre fate mapping approaches, which previously had been shown to identify mesenchymal progenitors in vitro. Consistent with this past work, sorted CTGF+ cells displayed an ability to differentiate into osteoblasts, chondrocytes, and adipocytes in vitro and into osteoblast, adipocyte, and stromal cell lineages after transplantation into a parietal bone defect. In vivo examination of CTGF reporter expression in bone tissue sections revealed that it marked cells highly localized to the trabecular bone region and was not expressed in the perichondrium or periosteum. Mesenchymal cells retaining high CTGF reporter expression were adjacent to, but distinct from mature osteoblasts lining bone surfaces and endothelial cells forming the vascular sinuses. Comparison of CTGF and Osterix reporter expression in bone tissue sections indicated an inverse correlation between the strength of CTGF expression and osteoblast maturation. Down-regulation of CTGF reporter expression also occurred during in vitro osteogenic differentiation. Collectively, our studies indicate that CTGF reporter mice selectively identify a subpopulation of bone marrow mesenchymal progenitor cells that reside in the trabecular bone region. Copyright © 2014 Elsevier Inc. All rights reserved.

  16. 3D histomorphometric quantification of trabecular bones by computed microtomography using synchrotron radiation.

    Science.gov (United States)

    Nogueira, L P; Braz, D; Barroso, R C; Oliveira, L F; Pinheiro, C J G; Dreossi, D; Tromba, G

    2010-12-01

    Conventional bone histomorphometry is an important method for quantitative evaluation of bone microstructure. X-ray computed microtomography is a non-invasive technique, which can be used to evaluate histomorphometric indices in trabecular bones (BV/TV, BS/BV, Tb.N, Tb.Th, Tb.Sp). In this technique, 3D images are used to quantify the whole sample, differently from the conventional one, in which the quantification is performed in 2D slices and extrapolated for 3D case. In this work, histomorphometric quantification using synchrotron 3D X-ray computed microtomography was performed to quantify the bone structure at different skeletal sites as well as to investigate the effects of bone diseases on quantitative understanding of bone architecture. The images were obtained at Synchrotron Radiation for MEdical Physics (SYRMEP) beamline, at ELETTRA synchrotron radiation facility, Italy. Concerning the obtained results for normal and pathological bones from same skeletal sites and individuals, from our results, a certain declining bone volume fraction was achieved. The results obtained could be used in forming the basis for comparison of the bone microarchitecture and can be a valuable tool for predicting bone fragility. Copyright © 2010 Elsevier Ltd. All rights reserved.

  17. Concentration dependence of fluorine impurity spin-lattice relaxation rate in bone mineral

    International Nuclear Information System (INIS)

    Code, R.F.; Armstrong, R.L.; Cheng, P.-T.

    1992-01-01

    The concentration dependence of the fluoride ion spin-lattice relaxation rate has been observed by nuclear magnetic resonance experiments on samples of defatted and dried bone. The 19 F spin-lattice relaxation rates increased linearly with bone fluoride concentration. Different results were obtained from trabecular than from cortical bone. For the same macroscopic fluoride content per gram of bone calcium, relaxation rate is significantly faster in cortical bone. Relaxation rates in cortical bone samples prepared from rats and dogs were apparently controlled by the same species-independent processes. For samples from beagle dogs, bulk fluoride concentrations measured by neutron activation analysis were 3.1±0.3 times greater in trabecular bone than in corresponding cortical bone. The beagle spin-lattice relaxation data suggest that microscopic fluoride concentrations in bone mineral were 1.8±0.4 times greater in trabecular bone than in cortical bone. It is concluded that accumulation of fluoride impurities in bone mineral is non-uniform. (author)

  18. Outcomes of combined trabecular micro-bypass and phacoemulsification in a predominantly Hispanic patient population

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    Gallardo MJ

    2016-10-01

    Full Text Available Mark J Gallardo,1,2 Richard A Supnet,1 Jane Ellen Giamporcaro,3 Dana M Hornbeak3 1El Paso Eye Surgeons, PA, El Paso, 2Department of Ophthalmology, University of Texas Health Science Center at San Antonio, San Antonio, TX, 3Division of Clinical Research and Medical Affairs, Glaukos Corporation, Laguna Hills, CA, USA Purpose: The purpose of this study was to evaluate intraocular pressure (IOP and topical ocular hypotensive medication burden at 12 months postoperatively in a predominantly Hispanic patient population with primary open-angle glaucoma each implanted with one trabecular micro-bypass stent during cataract surgery.Methods: This was a retrospective, consecutive case series. The main objective was to assess reduction of IOP and/or medication burden in all eyes at the 12-month postoperative exam. A secondary objective was to assess outcomes in 3 subgroups, distinguished preoperatively by IOP control and by medication burden (suboptimal or maximum therapy and with different treatment goals. Group 1 had medication-controlled IOP and goal to reduce medications while maintaining IOP control (n=65; Group 2 had uncontrolled IOP on ≤2 medications and goal to reduce IOP and maintain/reduce medication burden (n=31; and Group 3 had uncontrolled IOP on ≥3 medications and goal to reduce IOP and avoid filtering surgery (n=38. Evaluations included IOP, medication use, cup-to-disc ratio, visual fields, complications, and interventions. One hundred subjects (134 eyes have been followed for 12 months.Results: Most patients (80% were Hispanic and had moderate or severe glaucoma (87%. At 12 months, mean IOP reduced to 12.9 mmHg vs 16.5 mmHg preoperatively; 92% had an IOP ≤15 mmHg at 12 months (99% had ≤18 mmHg. Mean medication burden had decreased to 0.9 vs 2.3 preoperatively. At the 12-month time point, 94% of all eyes achieved their predefined treatment goal of reduced IOP and/or medications. Reductions in medication burden for Group 1, and

  19. A coherent/Compton scattering method employing an x-ray tube for measurement of trabecular bone mineral content

    International Nuclear Information System (INIS)

    Puumalainen, P.; Uimarihuhta, A.; Olkkonen, H.

    1982-01-01

    Results showed that the x-ray generator could be used as a radiation source in the coherent/Compton scattering method of measuring trabecular bone mineral content. The quasimonoenergetic x-ray beam was produced from the continuous bremsstrahlung radiation with the aid of a spectral filter. Of the two measuring arrangements that were tested, the semiconductor detector geometry appeared to give distinctly more reproducible results than the two NaI detector system. However, to improve the counting efficiency of the coherent radiation, the 'coherent' NaI detector could be replaced by a bore-through scintillation probe (bore diameter about 10mm). By placing the x-ray fluorescence target inside the bore, the yield would be considerably higher. The present method is suitable for TBMC measurements of small animal and human peripheral bones. Errors are discussed in relation to increase of bone size. (U.K.)

  20. Development and initial validation of a novel smoothed-particle hydrodynamics-based simulation model of trabecular bone penetration by metallic implants.

    Science.gov (United States)

    Kulper, Sloan A; Fang, Christian X; Ren, Xiaodan; Guo, Margaret; Sze, Kam Y; Leung, Frankie K L; Lu, William W

    2018-04-01

    A novel computational model of implant migration in trabecular bone was developed using smoothed-particle hydrodynamics (SPH), and an initial validation was performed via correlation with experimental data. Six fresh-frozen human cadaveric specimens measuring 10 × 10 × 20 mm were extracted from the proximal femurs of female donors (mean age of 82 years, range 75-90, BV/TV ratios between 17.88% and 30.49%). These specimens were then penetrated under axial loading to a depth of 10 mm with 5 mm diameter cylindrical indenters bearing either flat or sharp/conical tip designs similar to blunt and self-tapping cancellous screws, assigned in a random manner. SPH models were constructed based on microCT scans (17.33 µm) of the cadaveric specimens. Two initial specimens were used for calibration of material model parameters. The remaining four specimens were then simulated in silico using identical material model parameters. Peak forces varied between 92.0 and 365.0 N in the experiments, and 115.5-352.2 N in the SPH simulations. The concordance correlation coefficient between experimental and simulated pairs was 0.888, with a 95%CI of 0.8832-0.8926, a Pearson ρ (precision) value of 0.9396, and a bias correction factor Cb (accuracy) value of 0.945. Patterns of bone compaction were qualitatively similar; both experimental and simulated flat-tipped indenters produced dense regions of compacted material adjacent to the advancing face of the indenter, while sharp-tipped indenters deposited compacted material along their peripheries. Simulations based on SPH can produce accurate predictions of trabecular bone penetration that are useful for characterizing implant performance under high-strain loading conditions. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1114-1123, 2018. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  1. Calcium and phosphorus concentrations and the calcium/phosphorus ratio in trabecular bone from the femoral neck of healthy humans as determined by neutron activation analysis

    International Nuclear Information System (INIS)

    Zaichick, Vladimir; Tzaphlidou, Margaret

    2003-01-01

    The Ca and P concentrations as well as the Ca/P ratio were estimated in intact trabecular bone samples from the femoral neck of healthy humans, 34 women and 44 men, aged from 15 to 55 years, using instrumental neutron activation analysis. The mean values (M±SD) for the investigated parameters (on a dry-weight basis) were: 12.1±3.0%, 5.94±1.71%, 2.07±0.25 and 10.9±2.5%, 5.30±1.23%, 2.07±0.22 for females and males, respectively. A statistically significant (p≤0.05) decrease of Ca concentration with age was found only for males while the P concentration and the Ca/P ratio were not affected by age. No statistically significant sex-related differences were observed in any of the parameters. The mean values for Ca, P and the Ca/P ratio lay close to the median of the very wide range of published data. The individual variation for the Ca/P ratio in trabecular bone from the healthy human femoral neck was lower than those for Ca and P separately. This suggests that the specificity of the Ca/P ratio is better than that of Ca and P concentrations and may be more reliable for the diagnosis of bone disorders

  2. Visibility of trabecular meshwork by standard and polarization-sensitive optical coherence tomography

    Science.gov (United States)

    Yasuno, Yoshiaki; Yamanari, Masahiro; Kawana, Keisuke; Miura, Masahiro; Fukuda, Shinichi; Makita, Shuichi; Sakai, Shingo; Oshika, Tetsuro

    2010-11-01

    Polarization-sensitive optical coherence tomography (PS-OCT) is known to be advantageous because of its additional tissue-specific contrast of the anterior eye. So far, this advantage has been shown only qualitatively. We evaluate the improved visibility afforded by 3-D PS corneal and anterior eye segment OCT (PS-CAS-OCT) in visualizing the trabecular meshwork (TM) based on statistical evidences. A total of 31 normal subjects participated in this study. The anterior eye segments of both the eyes of the subjects are scanned using a custom-made PS-CAS-OCT and the standard-scattering OCT (S-OCT) and polarization-sensitive phase-retardation OCT (P-OCT) images are obtained. Three graders grade the visibility of the TM using a four-leveled grading system. The intergrader agreement, intermodality differences, and interquadrant dependence of visibility are statistically examined. All three of three combinations of graders show substantial agreement in visibility with P-OCT (ρ = 0.74, 0.70, and 0.68, Spearman's correlation), while only one of three shows substantial agreement with S-OCT (ρ = 0.72). Significant dependence of the visibility on the modality (S-OCT versus P-OCT) and quadrants are found by the analysis of variance. A subsequent Wilcoxon signed-rank test reveals significantly improved visibility. PS-CAS-OCT may become a useful tool for screening angle-closure glaucoma.

  3. TRABECULAR BONE SCORE – A NON-INVASIVE ANALYTICAL METHOD TO EVALUATE BONE QUALITY BASED ON ROUTINE DUAL-ENERGY ABSORPTIOMETRY. PERSPECTIVES OF ITS USE IN CLINICAL PRACTICE

    Directory of Open Access Journals (Sweden)

    T. T. Tsoriev

    2016-01-01

    Full Text Available Two-dimensional dual-energy X-ray absorptiometry (DXA, osteodensitometry is currently considered as the gold standard for diagnosis of osteoporosis. However, despite good operational characteristics, this type of investigation cannot help to assess bone microarchitecture and the degree of its derangement in osteoporosis. Therefore, trabecular bone score (TBS has been developed as a  non-invasive method of indirect description of bone microarchitecture based on data derived from a  standard DXA of the lumbar spine. Not being a direct mapping of the physical measurements of trabecular microarchitecture, TBS nevertheless shows a positive correlation with quantitative values obtained from micro-computed tomography and high resolution peripheral quantitative computed tomography, i.e. with the bone volume fraction, junction density, trabecular numbers and their disintegration. There is also an association between the ability of the bone tissue to resist stress in experimental studies ex vivo and TBS measurement. Due to TBS, there is a possibility to detect bone microarchitecture impairment even in individuals with normal bone mineral density (BMD, i.e. higher TBS values correlate with improved bone microstructure, whereas a  reduced TBS shows its deterioration. Limitation of TBS use are primarily related to the DXA image quality: image faults caused either by technical reasons or by too low or too high body mass index can lead to an overestimation/underestimation of the index. Assessment of the lumbar TBS has been repeatedly performed in cross-sectional and prospective studies in representative patient samples (mainly postmenopausal women and significant numbers of healthy subjects, and proved to be a predictor (independent of BMD of fracture risk. An evaluation of the possibility to use TBS for early diagnosis of secondary osteoporosis (related to various endocrine disorders  would be of great interest, as BMD, as known from clinical

  4. Initial clinical experience with the trabecular micro-bypass stent in patients with glaucoma.

    Science.gov (United States)

    Spiegel, Detlev; Wetzel, Wolfgang; Haffner, David S; Hill, Richard A

    2007-01-01

    This study was undertaken to evaluate the efficiency of a trabecular micro-bypass stent designed to allow direct aqueous drainage from the anterior chamber into Schlemm's canal in patients with glaucoma. In this prospective case series of 6 patients with open-angle glaucoma, the microstent was inserted ab interno under local anesthesia in an ophthalmic operating room. Patients were seen postoperatively at 1 to 2 d, 1 wk, and 1, 2, 6, and 12 mo. All stents were successfully placed within Schlemm's canal. Mean intraocular pressure (IOP) at preoperative baseline was 20.2+/-6.3 mm Hg (range, 14-31 mm Hg). Mean IOP decreased during the immediate postoperative period to approximately 12 to 13 mm Hg and was stabilized at 14 to 15 mm Hg with reduction of medication throughout 1 y of follow-up. No major complications occurred. According to observations reported in this feasibility study, the microstent was effective in reducing IOP and in decreasing the number of glaucoma medications required to control IOP. Implantation procedures were safe, and stents remained in place throughout the follow-up period. None of the complications traditionally associated with filtering surgery were reported. Further research on this stent in a larger group of patients is needed to assess its role in glaucoma therapy.

  5. Skeletal site-specific effects of whole body vibration in mature rats: from deleterious to beneficial frequency-dependent effects.

    Science.gov (United States)

    Pasqualini, Marion; Lavet, Cédric; Elbadaoui, Mohamed; Vanden-Bossche, Arnaud; Laroche, Norbert; Gnyubkin, Vasily; Vico, Laurence

    2013-07-01

    Whole body vibration (WBV) is receiving increasing interest as an anti-osteoporotic prevention strategy. In this context, selective effects of different frequency and acceleration magnitude modalities on musculoskeletal responses need to be better defined. Our aim was to investigate the bone effects of different vibration frequencies at constant g level. Vertical WBV was delivered at 0.7 g (peak acceleration) and 8, 52 or 90 Hz sinusoidal vibration to mature male rats 10 min daily for 5 days/week for 4 weeks. Peak accelerations measured by skin or bone-mounted accelerometers at L2 vertebral and tibia crest levels revealed similar values between adjacent skin and bone sites. Local accelerations were greater at 8 Hz compared with 52 and 90 Hz and were greater in vertebra than tibia for all the frequencies tested. At 52 Hz, bone responses were mainly seen in L2 vertebral body and were characterized by trabecular reorganization and stimulated mineral apposition rate (MAR) without any bone volume alteration. At 90 Hz, axial and appendicular skeletons were affected as were the cortical and trabecular compartments. Cortical thickness increased in femur diaphysis (17%) along with decreased porosity; trabecular bone volume increased at distal femur metaphysis (23%) and even more at L2 vertebral body (32%), along with decreased SMI and increased trabecular connectivity. Trabecular thickness increased at the tibia proximal metaphysis. Bone cellular activities indicated a greater bone formation rate, which was more pronounced at vertebra (300%) than at long bone (33%). Active bone resorption surfaces were unaffected. At 8 Hz, however, hyperosteoidosis with reduced MAR along with increased resorption surfaces occurred in the tibia; hyperosteoidosis and trend towards decreased MAR was also seen in L2 vertebra. Trabecular bone mineral density was decreased at femur and tibia. Thus the most favorable regimen is 90 Hz, while deleterious effects were seen at 8 Hz. We concluded that

  6. Genetic and environmental variances of bone microarchitecture and bone remodeling markers: a twin study.

    Science.gov (United States)

    Bjørnerem, Åshild; Bui, Minh; Wang, Xiaofang; Ghasem-Zadeh, Ali; Hopper, John L; Zebaze, Roger; Seeman, Ego

    2015-03-01

    All genetic and environmental factors contributing to differences in bone structure between individuals mediate their effects through the final common cellular pathway of bone modeling and remodeling. We hypothesized that genetic factors account for most of the population variance of cortical and trabecular microstructure, in particular intracortical porosity and medullary size - void volumes (porosity), which establish the internal bone surface areas or interfaces upon which modeling and remodeling deposit or remove bone to configure bone microarchitecture. Microarchitecture of the distal tibia and distal radius and remodeling markers were measured for 95 monozygotic (MZ) and 66 dizygotic (DZ) white female twin pairs aged 40 to 61 years. Images obtained using high-resolution peripheral quantitative computed tomography were analyzed using StrAx1.0, a nonthreshold-based software that quantifies cortical matrix and porosity. Genetic and environmental components of variance were estimated under the assumptions of the classic twin model. The data were consistent with the proportion of variance accounted for by genetic factors being: 72% to 81% (standard errors ∼18%) for the distal tibial total, cortical, and medullary cross-sectional area (CSA); 67% and 61% for total cortical porosity, before and after adjusting for total CSA, respectively; 51% for trabecular volumetric bone mineral density (vBMD; all p accounted for 47% to 68% of the variance (all p ≤ 0.001). Cross-twin cross-trait correlations between tibial cortical porosity and medullary CSA were higher for MZ (rMZ  = 0.49) than DZ (rDZ  = 0.27) pairs before (p = 0.024), but not after (p = 0.258), adjusting for total CSA. For the remodeling markers, the data were consistent with genetic factors accounting for 55% to 62% of the variance. We infer that middle-aged women differ in their bone microarchitecture and remodeling markers more because of differences in their genetic factors than

  7. An adaptation model for trabecular bone at different mechanical levels

    Directory of Open Access Journals (Sweden)

    Lv Linwei

    2010-07-01

    Full Text Available Abstract Background Bone has the ability to adapt to mechanical usage or other biophysical stimuli in terms of its mass and architecture, indicating that a certain mechanism exists for monitoring mechanical usage and controlling the bone's adaptation behaviors. There are four zones describing different bone adaptation behaviors: the disuse, adaptation, overload, and pathologic overload zones. In different zones, the changes of bone mass, as calculated by the difference between the amount of bone formed and what is resorbed, should be different. Methods An adaptation model for the trabecular bone at different mechanical levels was presented in this study based on a number of experimental observations and numerical algorithms in the literature. In the proposed model, the amount of bone formation and the probability of bone remodeling activation were proposed in accordance with the mechanical levels. Seven numerical simulation cases under different mechanical conditions were analyzed as examples by incorporating the adaptation model presented in this paper with the finite element method. Results The proposed bone adaptation model describes the well-known bone adaptation behaviors in different zones. The bone mass and architecture of the bone tissue within the adaptation zone almost remained unchanged. Although the probability of osteoclastic activation is enhanced in the overload zone, the potential of osteoblasts to form bones compensate for the osteoclastic resorption, eventually strengthening the bones. In the disuse zone, the disuse-mode remodeling removes bone tissue in disuse zone. Conclusions The study seeks to provide better understanding of the relationships between bone morphology and the mechanical, as well as biological environments. Furthermore, this paper provides a computational model and methodology for the numerical simulation of changes of bone structural morphology that are caused by changes of mechanical and biological

  8. Effects of benzalkonium chloride- or polyquad-preserved fixed combination glaucoma medications on human trabecular meshwork cells.

    Science.gov (United States)

    Ammar, David A; Kahook, Malik Y

    2011-01-01

    We investigated the potential short and long-term effects in cultured human trabecular meshwork (TM) cells of various topical glaucoma formulations containing different preservatives. We tested the fixed combination medications 0.004% travoprost plus 0.5% timolol preserved with either 0.015% benzalkonium chloride (BAK; DuoTrav®), or with 0.001% polyquad (PQ; DuoTrav(®) BAK-free); and 0.005% latanoprost plus 0.5% timolol preserved with 0.020% BAK (Xalacom(®)). Also tested was a range of BAK concentrations (0.001%-0.020%) in balanced salt solution (BSS). Cells were treated for 25 min at 37 °C with solutions diluted 1:10 and 1:100 to mimic the reduced penetration of topical preparations to the anterior chamber. The percentage of live cells was determined immediately after treatment through the uptake of the fluorescent vital dye calcein-AM. To determine any long-term effects, we assayed release of matrix metalloproteinase 9 (MMP-9) and apoptosis 24 h after treatments. BAK demonstrated a dose-dependent reduction in TM cell viability, ranging from 71±5% live cells at 0.001% BAK (diluted 1:10) to 33±3% live cells at 0.020% BAK (diluted 1:10). Travoprost (0.004%) plus 0.5% timolol preserved with 0.015% BAK had statistically fewer live TM cells (79±7%) than the same preparation preserved with 0.001% polyquad® (PQ; 93±1%; p<0.001). Latanoprost plus timolol preserved with 0.020% BAK (29±9% live cells) was similar to the 0.020% BAK (33±3%) treatment. However, travoprost plus timolol preserved in 0.015% BAK had significantly more live cells (83±12%) than the 1:10 dilution of 0.015% BAK (49±10%). We also found 0.020% BAK (diluted 1:100) resulted in elevated levels of extracellular MMP-9 at 24 h. These results demonstrate that the substitution of the preservative BAK from topical ophthalmic drugs results in greater in vitro viability of TM cells. Travoprost with timolol, but not latanoprost with timolol, countered some of the toxic BAK effects. BAK treatment

  9. Prospective Evaluation of Two iStent® Trabecular Stents, One iStent Supra® Suprachoroidal Stent, and Postoperative Prostaglandin in Refractory Glaucoma: 4-year Outcomes.

    Science.gov (United States)

    Myers, Jonathan S; Masood, Imran; Hornbeak, Dana M; Belda, Jose I; Auffarth, Gerd; Jünemann, Anselm; Giamporcaro, Jane Ellen; Martinez-de-la-Casa, Jose M; Ahmed, Iqbal Ike K; Voskanyan, Lilit; Katz, L Jay

    2018-03-01

    This study evaluates long-term outcomes of two trabecular micro-bypass stents, one suprachoroidal stent, and postoperative prostaglandin in eyes with refractory open angle glaucoma (OAG). Prospective ongoing 5-year study of 80 eligible subjects (70 with 4-year follow-up) with OAG and IOP ≥ 18 mmHg after prior trabeculectomy and while taking 1-3 glaucoma medications. Subjects received two iStent ® trabecular micro-bypass stents, one iStent Supra ® suprachoroidal stent, and postoperative travoprost. Postoperative IOP was measured with medication and annually following medication washouts. Performance was measured by the proportion of eyes with ≥ 20% IOP reduction on one medication (the protocol-specified prostaglandin) versus preoperative medicated IOP (primary outcome); and the proportion of eyes with postoperative IOP ≤ 15 and ≤ 18 mmHg on one medication (secondary outcome). Additional clinical and safety data included medications, visual field, pachymetry, gonioscopy, adverse events, visual acuity, and slit-lamp and fundus examinations. Preoperatively, mean medicated IOP was 22.0 ± 3.1 mmHg on 1.2 ± 0.4 medications, and mean unmedicated IOP was 26.4 ± 2.4 mmHg. Postoperatively, among eyes without later cataract surgery, mean medicated IOP at all visits through 48 months was ≤ 13.7 mmHg (≥ 37% reduction), and annual unmedicated IOP was ≤ 18.4 mmHg (reductions of ≥ 30% vs. preoperative unmedicated IOP and ≥ 16% vs. preoperative medicated IOP). At all postoperative visits among eyes without additional surgery or medication, ≥ 91% of eyes had ≥ 20% IOP reduction on one medication versus preoperative medicated IOP. At month 48, 97 and 98% of eyes achieved IOP ≤ 15 and ≤ 18 mmHg, respectively, on one medication. Six eyes required additional medication, no eyes required additional glaucoma surgery, and safety measurements were favorable throughout follow-up. IOP control was achieved safely with two

  10. Direct estimation of human trabecular bone stiffness using cone beam computed tomography.

    Science.gov (United States)

    Klintström, Eva; Klintström, Benjamin; Pahr, Dieter; Brismar, Torkel B; Smedby, Örjan; Moreno, Rodrigo

    2018-04-10

    The aim of this study was to evaluate the possibility of estimating the biomechanical properties of trabecular bone through finite element simulations by using dental cone beam computed tomography data. Fourteen human radius specimens were scanned in 3 cone beam computed tomography devices: 3-D Accuitomo 80 (J. Morita MFG., Kyoto, Japan), NewTom 5 G (QR Verona, Verona, Italy), and Verity (Planmed, Helsinki, Finland). The imaging data were segmented by using 2 different methods. Stiffness (Young modulus), shear moduli, and the size and shape of the stiffness tensor were studied. Corresponding evaluations by using micro-CT were regarded as the reference standard. The 3-D Accuitomo 80 (J. Morita MFG., Kyoto, Japan) showed good performance in estimating stiffness and shear moduli but was sensitive to the choice of segmentation method. NewTom 5 G (QR Verona, Verona, Italy) and Verity (Planmed, Helsinki, Finland) yielded good correlations, but they were not as strong as Accuitomo 80 (J. Morita MFG., Kyoto, Japan). The cone beam computed tomography devices overestimated both stiffness and shear compared with the micro-CT estimations. Finite element-based calculations of biomechanics from cone beam computed tomography data are feasible, with strong correlations for the Accuitomo 80 scanner (J. Morita MFG., Kyoto, Japan) combined with an appropriate segmentation method. Such measurements might be useful for predicting implant survival by in vivo estimations of bone properties. Copyright © 2018 Elsevier Inc. All rights reserved.

  11. Pregnant ewes exposed to multiple endocrine disrupting pollutants through sewage sludge-fertilized pasture show an anti-estrogenic effect in their trabecular bone

    International Nuclear Information System (INIS)

    Lind, P. Monica; Oberg, Denise; Larsson, Sune; Kyle, Carol E.; Orberg, Jan; Rhind, Stewart M.

    2010-01-01

    Pregnant ewes were maintained on pastures fertilized, twice yearly, with either sewage sludge (2.25 tonnes dry matter/ha; Treated; T) or inorganic fertilizer containing equivalent amounts of nitrogen (Control; C), to determine effects on maternal and fetal bone structures, density and mechanical properties of exposure to environmental concentrations of multiple endocrine disrupting compounds (EDCs) and heavy metal pollutants. The ewes were maintained on the respective pastures from the age of about 8 months until they were 4-6 years of age and they were slaughtered at 110 d gestation. Metaphyseal parts of adult ewe femurs exhibited a significantly reduced mean, total cross sectional area (CSA, - 4%; p 3 , - 8.0%; p 2 , - 11.1%; p < 0.05) in T compared with C animals. Femurs of T ewes were stronger than those of C ewes but this may reflect greater body weights. At the mid-diaphyseal part of the fetal bones, there was a reduction in endosteal circumference (- 6.7%, p < 0.05) and marrow cavity area (- 13.8%, p < 0.05) in the female T fetuses compared with female C fetuses. In the male fetuses the mid-diaphyseal part total bone mineral content was higher (+ 3.0%, p < 0.05) in T than in C animals. No treatment difference in biomechanical bending was detected in the fetuses. It is concluded that ewes grazing pasture fertilized with sewage sludge exhibited an anti-estrogenic effect on their trabecular bone in the form of reduced mineral content and density, despite increased body weight. It is suggested that human exposure to low levels of multiple EDCs may have implications for bone structure and human health.

  12. Would Interstitial Fluid Flow be Responsible for Skeletal Maintenance in Tail-Suspended Rats?

    Science.gov (United States)

    Li, Wen-Ting; Huang, Yun-Fei; Sun, Lian-Wen; Luan, Hui-Qin; Zhu, Bao-Zhang; Fan, Yu-Bo

    2017-02-01

    Despite the fast development of manned space flight, the mechanism and countermeasures of weightlessness osteoporosis in astronauts are still within research. It is accepted that unloading has been considered as primary factor, but the precise mechanism is still unclear. Since bone's interstitial fluid flow (IFF) is believed to be significant to nutrient supply and waste metabolism of bone tissue, it may influence bone quality as well. We investigated IFF's variation in different parts of body (included parietal bone, ulna, lumbar, tibia and tailbone) of rats using a tail-suspended (TS) system. Ten female Sprague-Dawley (SD) rats were divided into two groups: control (CON) and tail-suspension (TS) group. And after 21 days' experiment, the rats were injected reactive red to observe lacuna's condition under a confocal laser scanning microscope. The variations of IFF were analyzed by the number and area of lacuna. Volumetric bone mineral density (vBMD) and microarchitecture of bones were evaluated by micro-CT. The correlation coefficients between lacuna's number/area and vBMD were also analyzed. According to our experimental results, a 21 days' tail-suspension could cause a decrease of IFF in lumbar, tibia and tailbone and an increase of IFF in ulna. But in parietal bone, it showed no significant change. The vBMD and microarchitecture parameters also decreased in lumbar and tibia and increased in ulna. But in parietal bone and tailbone, it showed no significant change. And correlation analysis showed significant correlation between vBMD and lacuna's number in lumbar, tibia and ulna. Therefore, IFF decrease may be partly contribute to bone loss in tail-suspended rats, and it should be further investigated.

  13. Development of a 3-D x-ray micro-tomography system and its application to trabecular bone/cement interface

    International Nuclear Information System (INIS)

    Chi, Yong Ki; Cho, Gyuseong

    2004-01-01

    In recent years, the interface analysis of micro-structure based objects is an important research in osteoporosis, vascular imaging since a 3-D X-ray micro-tomography system was developed. However, the micro-tomographic image shows the white-out appearance in case of imaging of similar density objects with low energy X-ray. Therefore these images must be analyzed about the interface between microstructure based objects for its application to biomechanical study. Many published studies suggested approximately assumed model of interface and predicted mechanical failure by means of Finite Element Method (FEM) but these FEM analysis has not used for modeling the real structure and interface between objects such as roughness, voids and pores of objects. We developed micro-tomography system and suggest the application of micro-tomographic image for predicting mechanical failure at the interface. The micro-tomography system consists of a 5 μm micro-focus X-ray tube, a CMOS-based image sensor and a rotating sample holder controlled by a precision motor. CMOS image sensor has 62x62 mm 2 sensing area and uses optical lenses system for increasing resolution. The sample which was manufactured by implanting cement in a pig hip bone was used and its fracture is considered to be an important cause of loosening of hip joint replacement in orthopedic implants. A Feldkamp's cone-beam reconstruction algorithm on the equispatial detector case was used for bone/cement 3D volume data and the analysis of a trabecular bone/cement interface containing white-out appearance was performed by using multiple criterion segmentation of region and volume. Finally, the segmented data can be used for fracture prediction of FEM by determining node of hexahedron meshing. In this paper, we present development of a 3-D cone beam micro-tomographic system with CMOS image sensor and its application to a complex structure of a trabecular bone and implanted cement for predicting the failure mechanism of

  14. Effect of β-hydroxy-β-methylbutyrate (HMB) administration on volumetric bone mineral density, and morphometric and mechanical properties of tibia in male turkeys.

    Science.gov (United States)

    Tatara, M R

    2009-12-01

    This study was performed to investigate the effects of β-hydroxy-β-methylbutyrate (HMB) administration on skeletal system properties in turkeys. Thirty-two males were randomly divided into two groups at the age of 35 days of life. The first group included control turkeys (n = 16) treated with placebo, while the second group of birds (HMB group; n = 16) was administered orally with calcium salt of HMB during the last 15 weeks of life. The turkeys were sacrificed at the age of 20 weeks and tibia was isolated for analysis of bone geometrical parameters, volumetric bone mineral density (vBMD) and mechanical properties. Furthermore, assessment of free amino acid concentrations in plasma was performed. The results showed a 6.3% increase of vBMD of tibia in response to HMB treatment (p HMB-treated turkeys by 21.3%, 49.0%, 27.2% and 28.3%, respectively (p ≤ 0.01). β-hydroxy-β-methylbutyrate administration increased plasma concentrations of proline,glutamate, leucine, isoleucine, valine, alanine, aspartate, phenylalanine and cysteic acid (p HMB improves vBMD, and geometrical and mechanical properties of skeletal system in turkeys, and that these effects are associated with improved plasma amino acid concentrations.

  15. Periodontal regeneration using a bilayered PLGA/calcium phosphate construct.

    Science.gov (United States)

    Carlo Reis, Emily C; Borges, Andréa P B; Araújo, Michel V F; Mendes, Vanessa C; Guan, Limin; Davies, John E

    2011-12-01

    The regeneration of tissues affected by periodontal disease is a complex process; it encompasses the formation of bone, cementum and periodontal ligament. We developed a semi-rigid PLGA (polylactide-co-glycolide acid)/CaP (calcium phosphate) bilayered biomaterial construct to promote periodontal regeneration, which has a continuous outer barrier membrane and an inner topographically complex component. Our experimental model compared periodontal prophylaxis alone with prophylaxis and biomaterial implantation in the treatment of class II furcation defects in dogs. Clinical evaluation, micro-computed tomography, histology and backscattered electron imaging were used for data analysis. Healing occurred uneventfully and bone volumetric values, trabecular number and trabecular thickness were all significantly greater in the treated group; while trabecular separation was significantly greater in the control group. New cementum, bone, and periodontal ligament with Sharpey fibre insertions were only seen in the treated group. Although periodontal regeneration has been reported elsewhere, the advantages of employing our bilayered PLGA + CaP construct are twofold: 1)it did not collapse into the defect; and, 2) its inner side was able to retain the blood clot throughout the buccal defect. The result was greater periodontal regeneration than has previously been reported with traditional flexible membranes. Copyright © 2011 Elsevier Ltd. All rights reserved.

  16. Greater happiness for a greater number: Is that possible in Austria?

    NARCIS (Netherlands)

    R. Veenhoven (Ruut)

    2011-01-01

    textabstractWhat is the final goal of public policy? Jeremy Bentham (1789) would say: greater happiness for a greater number. He thought of happiness as subjective enjoyment of life; in his words as “the sum of pleasures and pains”. In his time the happiness of the great number could not be measured

  17. Greater happiness for a greater number: Is that possible in Germany?

    NARCIS (Netherlands)

    R. Veenhoven (Ruut)

    2009-01-01

    textabstractWhat is the final goal of public policy? Jeremy Bentham (1789) would say: greater happiness for a greater number. He thought of happiness as subjective enjoyment of life; in his words as “the sum of pleasures and pains”. In his time the Happiness of the great number could not be measured

  18. Bone mineral measurements of subchondral and trabecular bone in healthy and osteoporotic rabbits

    International Nuclear Information System (INIS)

    Castaneda, S; Largo, R.; Marcos, M.E.; Herrero-Beaumont, G.; Calvo, E.; Rodriguez-Salvanes, F.; Diaz-Curiel, M.

    2006-01-01

    Experimental models of osteoporosis in rabbits are useful to investigate anabolic agents because this animal has a fast bone turnover with predominant remodelling over the modelling processes. For that purpose, it is necessary to characterize the densitometric values of each type of bony tissue. To determine areal bone mass measurement in the spine and in trabecular, cortical and subchondral bone of the knee in healthy and osteoporotic rabbits. Bone mineral content and bone mineral density were measured in lumbar spine, global knee, and subchondral and cortical bone of the knee with dual energy X-ray absorptiometry using a Hologic QDR-1000/W densitometer in 29 skeletally mature female healthy New Zealand rabbits. Ten rabbits underwent triplicate scans for evaluation of the effect of repositioning. Osteoporosis was experimentally induced in 15 rabbits by bilateral ovariectomy and postoperative corticosteroid treatment for 4 weeks. Identical dual energy X-ray absorptiometry (DXA) studies were performed thereafter. Mean values of bone mineral content at the lumbar spine, global knee, subchondral bone and cortical tibial metaphysis were: 1934±217 mg, 878±83 mg, 149±14 mg and 29±7.0 mg, respectively. The mean values of bone mineral density at the same regions were: 298±24 mg/cm 2 , 455±32 mg/cm 2 , 617±60 mg/cm 2 and 678±163 mg/cm 2 , respectively. (orig.)

  19. Trabecular bone score as a skeletal fragility index in acromegaly patients.

    Science.gov (United States)

    Hong, A R; Kim, J H; Kim, S W; Kim, S Y; Shin, C S

    2016-03-01

    Lumbar spine trabecular bone score (TBS) was significantly decreased in active acromegaly patients. TBS may be useful to assess the skeletal fragility in acromegaly in which bone mineral density (BMD) is not sufficient to represent bone strength and explain the high incidence of fragility fractures in acromegaly patients. Although the data on BMD are controversial, patients with acromegaly have an increased risk of fragility fracture. We examined the lumbar spine TBS to explain the skeletal deterioration in acromegaly patients. We included 14 men and 19 women acromegaly patients who underwent dual-energy X-ray absorptiometry at the time of diagnosis from 2000 to 2014 at Seoul National University Hospital. Ninety-nine age-, sex- and body mass index-matched controls were recruited. Biochemical parameters, lumbar spine TBS, and BMD at all sites were measured. Gonadal status was evaluated at diagnosis. Lumbar spine TBS was lower in acromegaly patients than in controls in both genders (1.345 ± 0.121 vs. 1.427 ± 0.087, P = 0.005 in men; 1.356 ± 0.082 vs. 1.431 ± 0.071, P = 0.001 in women). In contrast, BMD at all sites did not differ between the two groups. Hypogonadal acromegaly patients (men, n = 9; women, n = 12) had lower TBS values compared with controls both in men and women (all P acromegaly patients, lumbar spine TBS was lower than in women controls only (P = 0.041). Skeletal microarchitecture was deteriorated in acromegaly patients as assessed by TBS, which seems to be a consequence of growth hormone excess as well as hypogonadism, especially in women.

  20. A multicenter retrospective comparison of goniotomy versus trabecular bypass device implantation in glaucoma patients undergoing cataract extraction

    Directory of Open Access Journals (Sweden)

    Dorairaj SK

    2018-04-01

    Full Text Available Syril K Dorairaj,1 Malik Y Kahook,2 Blake K Williamson,3 Leonard K Seibold,4 Mohammed K ElMallah,5 Inder P Singh6 On behalf of the KDB Goniotomy Study Group 1Department of Ophthalmology, Mayo Clinic, Jacksonville, FL, 2School of Medicine, University of Colorado, Denver, CO, 3Williamson Eye Center, Baton Rouge, LA, 4School of Medicine, University of Colorado, Aurora, CO, 5Ocala Eye, Ocala, FL, 6The Eye Center of Racine and Kenosha, Kenosha, WI, USA Purpose: The aim of this study was to compare intraocular pressure (IOP outcomes in eyes with cataract and glaucoma undergoing phacoemulsification (phaco in combination with goniotomy using the Kahook Dual Blade (KDB or implantation of a single iStent trabecular bypass device.Methods: Retrospective analysis of IOP and IOP-lowering medication reduction in eyes undergoing phaco-goniotomy with KDB (n=237 or phaco-iStent (n=198. Preoperative, intraoperative, and postoperative data were collected through 6 months of follow-up. Outcome measures included mean IOP reduction, mean reduction in IOP-lowering medications, and the proportion of eyes achieving ≥20% IOP reduction or ≥1 medication reduction from baseline.Results: Mean IOP in the phaco-goniotomy with KDB group decreased from 17.9±4.4 mmHg at baseline to 13.6±2.7 mmHg at Month 6 (P<0.001, with mean medication use decreasing from 1.7±0.9 to 0.6±1.0 (P<0.001. In the phaco-iStent group, mean IOP decreased from 16.7±4.4 mmHg to 13.9±2.7 mmHg (P<0.001, with mean IOP-lowering medication use decreasing from 1.9±0.9 to 1.0±1.0 (P<0.001. Mean IOP reduction from baseline was significantly greater in the phaco-goniotomy with KDB group at Month 6 (phaco-goniotomy with KDB −4.2 mmHg [23.7%] vs phaco-iStent −2.7 mmHg [16.4%]; P<0.001. IOP-lowering medication reduction was greater in the phaco-goniotomy with KDB group compared to the phaco-iStent group (1.1 vs 0.9 medications, respectively; P=0.001. The most common adverse event was IOP spikes

  1. Is Trabecular Bone Score Valuable in Bone Microstructure Assessment after Gastric Bypass in Women with Morbid Obesity?

    Directory of Open Access Journals (Sweden)

    Agustina Pia Marengo

    2017-12-01

    Full Text Available Introduction: The effects of bariatric surgery on skeletal health raise many concerns. Trabecular bone score (TBS is obtained through the analysis of lumbar spine dual X-ray absorptiometry (DXA images and allows an indirect assessment of skeletal microarchitecture (MA. The aim of our study was to evaluate the changes in bone mineral density (BMD and alterations in bone microarchitecture assessed by TBS in morbidly obese women undergoing Roux-en-Y gastric bypass (RYGB, over a three-year follow-up. Material/Methods: A prospective study of 38 morbidly obese white women, aged 46.3 ± 8.2 years, undergoing RYGB was conducted. Biochemical analyses and DXA scans with TBS evaluation were performed before and at one year and three years after surgery. Results: Patients showed normal calcium and phosphorus plasma concentrations throughout the study. However, 25-hydroxyvitamin D (25(OHD3 decreased, and 71% of patients had a vitamin D deficiency at three years. BMD at femoral neck and lumbar spine (LSBMD significantly decreased 13.53 ± 5.42% and 6.03 ± 6.79%, respectively, during the three-year follow-up; however Z-score values remained above those for women of the same age. TBS was within normal ranges at one and three years (1.431 ± 106 and 1.413 ± 85, respectively, and at the end of the study, 73.7% of patients had normal bone MA. TBS at three years correlated inversely with age (r = −0.41, p = 0.010, body fat (r = −0.465, p = 0.004 and greater body fat deposited in trunk (r = −0.48, p = 0.004, and positively with LSBMD (r = 0.433, p = 0.007, fat mass loss (r = 0.438, p = 0.007 and lean mass loss (r = 0.432, p = 0.008. In the regression analysis, TBS remained associated with body fat (β = −0.625, p = 0.031; R2 = 0.47. The fracture risk, calculated by FRAX® (University of Sheffield, Sheffield, UK, with and without adjustment by TBS, was low. Conclusion: Women undergoing RYGB in the mid-term have a preserved bone MA, assessed by TBS.

  2. Medullar fat influences texture analysis of trabecular microarchitecture on X-ray radiographs

    International Nuclear Information System (INIS)

    Chappard, Daniel; Pascaretti-Grizon, Florence; Gallois, Yves; Mercier, Philippe; Basle, Michel F.; Audran, Maurice

    2006-01-01

    Alteration of trabecular architecture is a predictor of fracture risk in osteoporosis. Until now, microarchitecture analysis is difficult to evaluate in routine clinical practice for osteoporosis. Texture analysis on X-ray images has been advocated to be a suitable method to assess microarchitecture in bone diseases. The X-ray acquisition conditions have been often taken into consideration; however, the influence of anatomical conditions on texture parameters has received little interest. Because fat is a well-known problem with computed tomography and densitometry, we have designed a cadaver study to compare the influence of marrow lipids on numerous texture parameters. Twenty-one human distal radii were obtained, radiographed, and analyzed using a software that measures: heterogeneity, skeletonized parameters, run-lengths and fractal dimensions. Texture parameters were measured before, and after an extensive delipidation period lasting 3 weeks. Quality of the radiographs was improved after defatting. Delipidation had a very significant effect on measurements: afterwards defatting, the images were less blurred, and a better delineation of trabeculae and marrow cavities was obtained. This provoked an increase of parameters based on the grey level distribution but had no influence on parameters describing the reticulated honeycomb microarchitecture of the trabeculae (i.e., fractal dimension). Some parameters appeared anisotropy-sensitive, due to the different constitution and size of the trabeculae. The fat content of bone marrow induces noise that can modify some texture parameters. One should take into account the fat content of the marrow when using texture analysis to compare patients with osteoporosis due to various etiologies

  3. Accuracy of DXA scanning of the thoracic spine: cadaveric studies comparing BMC, areal BMD and geometric estimates of volumetric BMD against ash weight and CT measures of bone volume.

    Science.gov (United States)

    Sran, Meena M; Khan, Karim M; Keiver, Kathy; Chew, Jason B; McKay, Heather A; Oxland, Thomas R

    2005-12-01

    Biomechanical studies of the thoracic spine often scan cadaveric segments by dual energy X-ray absorptiometry (DXA) to obtain measures of bone mass. Only one study has reported the accuracy of lateral scans of thoracic vertebral bodies. The accuracy of DXA scans of thoracic spine segments and of anterior-posterior (AP) thoracic scans has not been investigated. We have examined the accuracy of AP and lateral thoracic DXA scans by comparison with ash weight, the gold-standard for measuring bone mineral content (BMC). We have also compared three methods of estimating volumetric bone mineral density (vBMD) with a novel standard-ash weight (g)/bone volume (cm3) as measured by computed tomography (CT). Twelve T5-T8 spine segments were scanned with DXA (AP and lateral) and CT. The T6 vertebrae were excised, the posterior elements removed and then the vertebral bodies were ashed in a muffle furnace. We proposed a new method of estimating vBMD and compared it with two previously published methods. BMC values from lateral DXA scans displayed the strongest correlation with ash weight (r=0.99) and were on average 12.8% higher (pBMC (AP or lateral) was more strongly correlated with ash weight than areal bone mineral density (aBMD; AP: r=0.54, or lateral: r=0.71) or estimated vBMD. Estimates of vBMD with either of the three methods were strongly and similarly correlated with volumetric BMD calculated by dividing ash weight by CT-derived volume. These data suggest that readily available DXA scanning is an appropriate surrogate measure for thoracic spine bone mineral and that the lateral scan might be the scan method of choice.

  4. Joint unloading implant modifies subchondral bone trabecular structure in medial knee osteoarthritis: 2-year outcomes of a pilot study using fractal signature analysis

    Directory of Open Access Journals (Sweden)

    Miller LE

    2015-01-01

    Full Text Available Larry E Miller,1,2 Miki Sode,3 Thomas Fuerst,3 Jon E Block2 1Miller Scientific Consulting, Inc., Asheville, NC, USA; 2The Jon Block Group, San Francisco, CA, USA; 3Bioclinica, Newark, CA, USA Background: Knee osteoarthritis (OA is largely attributable to chronic excessive and aberrant joint loading. The purpose of this pilot study was to quantify radiographic changes in subchondral bone after treatment with a minimally invasive joint unloading implant (KineSpring® Knee Implant System.Methods: Nine patients with unilateral medial knee OA resistant to nonsurgical therapy were treated with the KineSpring System and followed for 2 years. Main outcomes included Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC pain, function, and stiffness subscores and independent core laboratory determinations of joint space width and fractal signature of the tibial cortex.Results: WOMAC scores, on average, improved by 92% for pain, 91% for function, and 79% for stiffness over the 2-year follow-up period. Joint space width in the medial compartment of the treated knee significantly increased from 0.9 mm at baseline to 3.1 mm at 2 years; joint space width in the medial compartment of the untreated knee was unchanged. Fractal signatures of the vertically oriented trabeculae in the medial compartment decreased by 2.8% in the treated knee and increased by 2.1% in the untreated knee over 2 years. No statistically significant fractal signature changes were observed in the horizontally oriented trabeculae in the medial compartment or in the horizontal or vertical trabeculae of the lateral compartment in the treated knee.Conclusion: Preliminary evidence suggests that the KineSpring System may modify knee OA disease progression by increasing joint space width and improving subchondral bone trabecular integrity, thereby reducing pain and improving joint function. Keywords: disease modification, KineSpring, joint space, pain, trabecular

  5. Capsid Mutated Adeno-Associated Virus Delivered to the Anterior Chamber Results in Efficient Transduction of Trabecular Meshwork in Mouse and Rat.

    Directory of Open Access Journals (Sweden)

    Barbara Bogner

    Full Text Available Adeno associated virus (AAV is well known for its ability to deliver transgenes to retina and to mediate improvements in animal models and patients with inherited retinal disease. Although the field is less advanced, there is growing interest in AAV's ability to target cells of the anterior segment. The purpose of our study was to fully articulate a reliable and reproducible method for injecting the anterior chamber (AC of mice and rats and to investigate the transduction profiles of AAV2- and AAV8-based capsid mutants containing self-complementary (sc genomes in the anterior segment of the eye.AC injections were performed in C57BL/6 mice and Sprague Dawley rats. The cornea was punctured anterior of the iridocorneal angle. To seal the puncture site and to prevent reflux an air bubble was created in the AC. scAAVs expressing GFP were injected and transduction was evaluated by immunohistochemistry. Both parent serotype and capsid modifications affected expression. scAAV2- based vectors mediated efficient GFP-signal in the corneal endothelium, ciliary non-pigmented epithelium (NPE, iris and chamber angle including trabecular meshwork, with scAAV2(Y444F and scAAV2(triple being the most efficient.This is the first study to semi quantitatively evaluate transduction of anterior segment tissues following injection of capsid-mutated AAV vectors. scAAV2- based vectors transduced corneal endothelium, ciliary NPE, iris and trabecular meshwork more effectively than scAAV8-based vectors. Mutagenesis of surface-exposed tyrosine residues greatly enhanced transduction efficiency of scAAV2 in these tissues. The number of Y-F mutations was not directly proportional to transduction efficiency, however, suggesting that proteosomal avoidance alone may not be sufficient. These results are applicable to the development of targeted, gene-based strategies to investigate pathological processes of the anterior segment and may be applied toward the development of gene

  6. A novel composite material specifically developed for ultrasound bone phantoms: cortical, trabecular and skull

    International Nuclear Information System (INIS)

    Wydra, A; Maev, R Gr

    2013-01-01

    In the various stages of developing diagnostic and therapeutic equipment, the use of phantoms can play a very important role in improving the process, help in implementation, testing and calibrations. Phantoms are especially useful in developing new applications and training new doctors in medical schools. However, devices that use different physical factors, such as MRI, Ultrasound, CT Scan, etc will require the phantom to be made of different physical properties. In this paper we introduce the properties of recently designed new materials for developing phantoms for ultrasonic human body investigation, which in today's market make up more than 30% in the world of phantoms. We developed a novel composite material which allows fabrication of various kinds of ultrasound bone phantoms to mimic most of the acoustical properties of human bones. In contrast to the ex vivo tissues, the proposed material can maintain the physical and acoustical properties unchanged for long periods of time; moreover, these properties can be custom designed and created to suit specific needs. As a result, we introduce three examples of ultrasound phantoms that we manufactured in our laboratory: cortical, trabecular and skull bone phantoms. The paper also presents the results of a comparison study between the acoustical and physical properties of actual human bones (reported in the referenced literatures) and the phantoms manufactured by us. (note)

  7. Monocyte chemotactic protein-1 deficiency attenuates and high-fat diet exacerbates bone loss in mice with Lewis lung carcinoma.

    Science.gov (United States)

    Yan, Lin; Nielsen, Forrest H; Sundaram, Sneha; Cao, Jay

    2017-04-04

    Bone loss occurs in obesity and cancer-associated complications including wasting. This study determined whether a high-fat diet and a deficiency in monocyte chemotactic protein-1 (MCP-1) altered bone structural defects in male C57BL/6 mice with Lewis lung carcinoma (LLC) metastases in lungs. Compared to non-tumor-bearing mice, LLC reduced bone volume fraction, connectivity density, trabecular number, trabecular thickness and bone mineral density and increased trabecular separation in femurs. Similar changes occurred in vertebrae. The high-fat diet compared to the AIN93G diet exacerbated LLC-induced detrimental structural changes; the exacerbation was greater in femurs than in vertebrae. Mice deficient in MCP-1 compared to wild-type mice exhibited increases in bone volume fraction, connectivity density, trabecular number and decreases in trabecular separation in both femurs and vertebrae, and increases in trabecular thickness and bone mineral density and a decrease in structure model index in vertebrae. Lewis lung carcinoma significantly decreased osteocalcin but increased tartrate-resistant acid phosphatase 5b (TRAP 5b) in plasma. In LLC-bearing mice, the high-fat diet increased and MCP-1 deficiency decreased plasma TRAP 5b; neither the high-fat diet nor MCP-1 deficiency resulted in significant changes in plasma concentration of osteocalcin. In conclusion, pulmonary metastasis of LLC is accompanied by detrimental bone structural changes; MCP-1 deficiency attenuates and high-fat diet exacerbates the metastasis-associated bone wasting.

  8. Influence of estrogen deficiency and tibolone therapy on trabecular and cortical bone evaluated by computed radiography system in rats Influência da deficiência estrogênica e do tratamento com tibolona no osso trabecular e cortical avaliada pelo sistema de radiografia computadorizada em ratas

    Directory of Open Access Journals (Sweden)

    Ana Carolina Bergmann de Carvalho

    2012-03-01

    Full Text Available PURPOSE: To verify the effects of tibolone administration on trabecular and cortical bone of ovariectomized female rats by computed radiography system (CRS. METHODS: The experiment was performed on two groups of rats previously ovariectomized, one received tibolone (OVX+T while the other did not (OVX, those groups were compared to a control group (C not ovariectomized. Tibolone administration (1mg/day began thirty days after the ovariectomy and the treatment remained for five months. At last, the animals were euthanized and femurs and tibias collected. Computed radiographies of the bones were obtained and the digital images were used to determine the bone optical density and cortical thickness on every group. All results were statistically evaluated with significance set at POBJETIVO: Verificar o efeito da administração de tibolona no tecido ósseo cortical e trabecular de ratas castradas através de radiografia computadorizada. MÉTODOS: O experimento foi realizado em dois grupos de ratas previamente ooforectomizadas, onde um grupo recebeu tibolona (OVX+T e o outro não (OVX. Esses grupos foram comparados a um grupo controle (C não ooforectomizado. A administração de tibolona (1mg/dia começou trinta dias após a ooforectomia e o tratamento teve duração de cinco meses. No final, os animais foram mortos e fêmures e tibias coletados. As radiografias computadorizadas dos ossos foram obtidas e as imagens digitais usadas para determinar a densidade óssea e a espessura cortical em todos os grupos. Todos os resultados foram avaliados estatisticamente com significância estabelecida a 5%. RESULTADOS: A administração de tibolona mostrou ser benéfica apenas para análise densitométrica da cabeça do fêmur, apresentando maiores valores de densidade comparada ao grupo OVX. Nenhuma diferença significativa foi encontrada para espessura óssea cortical. CONCLUSÃO: A ooforectomia ocasionou perda óssea nas regiões analisadas e a tibolona

  9. Fragility Fracture Incidence in Chronic Obstructive Pulmonary Disease (COPD) Patients Associates With Nanoporosity, Mineral/Matrix Ratio, and Pyridinoline Content at Actively Bone-Forming Trabecular Surfaces.

    Science.gov (United States)

    Paschalis, Eleftherios P; Gamsjaeger, Sonja; Dempster, David; Jorgetti, Vanda; Borba, Victoria; Boguszewski, Cesar L; Klaushofer, Klaus; Moreira, Carolina A

    2017-01-01

    Chronic obstructive pulmonary disease (COPD) is associated with low areal bone mineral density (aBMD) by dual-energy X-ray absorptiometry (DXA) and altered microstructure by bone histomorphometry and micro-computed tomography. Nevertheless, not all COPD patients sustain fragility fractures. In the present study, we used Raman microspectroscopic analysis to determine bone compositional properties at actively forming trabecular surfaces (based on double fluorescent labels) in iliac crest biopsies from 19 postmenopausal COPD patients (aged 62.1 ± 7.3 years). Additionally, we analyzed trabecular geometrical centers, representing tissue much older than the forming surfaces. Eight of the patients had sustained fragility fractures, and 13 had received treatment with inhaled glucocorticoids. None of the patients had taken oral glucocorticoids. The monitored parameters were mineral/matrix ratio (MM), nanoporosity, and relative glycosaminoglycan (GAG), lipid, and pyridinoline contents (PYD). There were no significant differences between the glucocorticoid-treated patients and those who did not receive any. On the other hand, COPD patients sustaining fragility fractures had significantly lower nanoporosity and higher MM and PYD values compared with COPD patients without fragility fractures. To the best of our knowledge, this is the first study to discriminate between fracture and non-fracture COPD patients based on differences in the material properties of bone matrix. Given that these bone material compositional differences are evident close to the cement line (a major bone interface), they may contribute to the inferior bone toughness and coupled with the lower lumbar spine bone mineral density values result in the fragility fractures prevalent in these patients. © 2016 American Society for Bone and Mineral Research. © 2016 American Society for Bone and Mineral Research.

  10. Long-term Risedronate Treatment Normalizes Mineralization and Continues to Preserve Trabecular Architecture: Sequential Triple Biopsy Studies with Micro-Computed Tomography

    International Nuclear Information System (INIS)

    Borah, B.; Dufresne, T.; Ritman, E.; Jorgensen, S.; Liu, S.; Chmielewski, P.; Phipps, R.; Zhou, X.; Sibonga, J.; Turner, R.

    2006-01-01

    The objective of the study was to assess the time course of changes in bone mineralization and architecture using sequential triple biopsies from women with postmenopausal osteoporosis (PMO) who received long-term treatment with risedronate. Transiliac biopsies were obtained from the same subjects (n = 7) at baseline and after 3 and 5 years of treatment with 5 mg daily risedronate. Mineralization was measured using 3-dimensional (3D) micro-computed tomography (CT) with synchrotron radiation and was compared to levels in healthy premenopausal women (n = 12). Compared to the untreated PMO women at baseline, the premenopausal women had higher average mineralization (Avg-MIN) and peak mineralization (Peak-MIN) by 5.8% (P = 0.003) and 8.0% (P = 0.003), respectively, and lower ratio of low to high-mineralized bone volume (BMR-V) and surface area (BMR-S) by 73.3% (P = 0.005) and 61.7% (P 0.003), respectively. Relative to baseline, 3 years of risedronate treatment significantly increased Avg-MIN (4.9 ± 1.1%, P = 0.016) and Peak-MIN (6.2 ± 1.5%, P = 0.016), and significantly decreased BMR-V (-68.4 ± 7.3%, P = 0.016) and BMR-S (-50.2 ± 5.7%, P = 0.016) in the PMO women. The changes were maintained at the same level when treatment was continued up to 5 years. These results are consistent with the significant reduction of turnover observed after 3 years of treatment and which was similarly maintained through 5 years of treatment. Risedronate restored the degree of mineralization and the ratios of low- to high-mineralized bone to premenopausal levels after 3 years of treatment, suggesting that treatment reduced bone turnover in PMO women to healthy premenopausal levels. Conventional micro-CT analysis further demonstrated that bone volume (BV/TV) and trabecular architecture did not change from baseline up to 5 years of treatment, suggesting that risedronate provided long-term preservation of trabecular architecture in the PMO women. Overall, risedronate provided sustained

  11. Radiation dose to trabecular bone marrow stem cells from 3H, 14C and selected α-emitters incorporated in a bone remodeling compartment

    International Nuclear Information System (INIS)

    Nie Huiling; Richardson, Richard B

    2009-01-01

    A Monte Carlo simulation of repeated cubic units representing trabecular bone cavities in adult bone was employed to determine absorbed dose fractions evaluated for 3 H, 14 C and a set of α-emitters incorporated within a bone remodeling compartment (BRC). The BRC consists of a well-oxygenated vascular microenvironment located within a canopy of bone-lining cells. The International Commission on Radiological Protection (ICRP) considers that an important target for radiation-induced bone cancer is the endosteum marrow layer adjacent to bone surface where quiescent bone stem cells reside. It is proposed that the active stem cells and progenitor cells located above the BRC canopy, the 'BRC stem cell niche', is a more important radiation-induced cancer target volume. Simulation results from a static model, where no remodeling occurs, indicate that the mean dose from bone and bone surface to the 50 μm quiescent bone stem cell niche, the current ICRP target, was substantially lower (two to three times lower) than that to the narrower and hypoxic 10 μm endosteum for 3 H, 14 C and α-particles with energy range 0.5-10 MeV. The results from a dynamic model indicate that the temporal α-radiation dose to active stem/progenitor cells located in the BRC stem cell niche from the material incorporated in and buried by forming bone was 9- to 111-fold greater than the dose to the quiescent bone stem cell niche. This work indicates that the remodeling portion of the bone surface, rather than the quiescent (endosteal) surface, has the greatest risk of radiation-induced bone cancer, particularly from short-range radiation, due to the elevated dose and the radiosensitizing oxygen effect.

  12. Additively manufactured 3D porous Ti-6Al-4V constructs mimic trabecular bone structure and regulate osteoblast proliferation, differentiation and local factor production in a porosity and surface roughness dependent manner

    International Nuclear Information System (INIS)

    Cheng, Alice; Boyan, Barbara D; Humayun, Aiza; Cohen, David J; Schwartz, Zvi

    2014-01-01

    Additive manufacturing by laser sintering is able to produce high resolution metal constructs for orthopedic and dental implants. In this study, we used a human trabecular bone template to design and manufacture Ti-6Al-4V constructs with varying porosity via laser sintering. Characterization of constructs revealed interconnected porosities ranging from 15–70% with compressive moduli of 2579–3693 MPa. These constructs with macro porosity were further surface-treated to create a desirable multi-scale micro-/nano-roughness, which has been shown to enhance the osseointegration process. Osteoblasts (MG63 cells) exhibited high viability when grown on the constructs. Proliferation (DNA) and alkaline phosphatase specific activity, an early differentiation marker, decreased as porosity increased, while osteocalcin, a late differentiation marker, as well as osteoprotegerin, vascular endothelial growth factor and bone morphogenetic proteins 2 and 4 increased with increasing porosity. Three-dimensional (3D) constructs with the highest porosity and surface modification supported the greatest osteoblast differentiation and local factor production. These results indicate that additively manufactured 3D porous constructs mimicking human trabecular bone and produced with additional surface treatment can be customized for increased osteoblast response. Increased factors for osteoblast maturation and differentiation on high porosity constructs suggest the enhanced performance of these surfaces for increasing osseointegration in vivo. (paper)

  13. Additively manufactured 3D porous Ti-6Al-4V constructs mimic trabecular bone structure and regulate osteoblast proliferation, differentiation and local factor production in a porosity and surface roughness dependent manner.

    Science.gov (United States)

    Cheng, Alice; Humayun, Aiza; Cohen, David J; Boyan, Barbara D; Schwartz, Zvi

    2014-10-07

    Additive manufacturing by laser sintering is able to produce high resolution metal constructs for orthopedic and dental implants. In this study, we used a human trabecular bone template to design and manufacture Ti-6Al-4V constructs with varying porosity via laser sintering. Characterization of constructs revealed interconnected porosities ranging from 15-70% with compressive moduli of 2579-3693 MPa. These constructs with macro porosity were further surface-treated to create a desirable multi-scale micro-/nano-roughness, which has been shown to enhance the osseointegration process. Osteoblasts (MG63 cells) exhibited high viability when grown on the constructs. Proliferation (DNA) and alkaline phosphatase specific activity, an early differentiation marker, decreased as porosity increased, while osteocalcin, a late differentiation marker, as well as osteoprotegerin, vascular endothelial growth factor and bone morphogenetic proteins 2 and 4 increased with increasing porosity. Three-dimensional (3D) constructs with the highest porosity and surface modification supported the greatest osteoblast differentiation and local factor production. These results indicate that additively manufactured 3D porous constructs mimicking human trabecular bone and produced with additional surface treatment can be customized for increased osteoblast response. Increased factors for osteoblast maturation and differentiation on high porosity constructs suggest the enhanced performance of these surfaces for increasing osseointegration in vivo.

  14. Preventive effects of omega-3 and omega-6 Fatty acids on peroxide mediated oxidative stress responses in primary human trabecular meshwork cells.

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    Theofilos Tourtas

    Full Text Available Pathologic processes in glaucoma include increased apoptosis, accumulation of extracellular material in the trabecular meshwork and optic nerve, condensations of the cytoskeleton and precocious cellular senescence. Oxidative stress was shown to generate these alterations in primary ocular cells. Fatty acids omega-3 and -6 are alleged to constitute a prophylaxis against these deleterious effects. Here, we tested actual preventive effects omega-3 and -6 against peroxide induced stress responses in primary human trabecular meshwork cells. Changes of mitochondrial activity, proliferation, heat shock proteins, extracellular matrix components, and inflammatory markers were evaluated. Alterations of the cytoskeleton were evaluated by phalloidin labeling. Here we report a repressive effect of omega-6 on metabolic activity and proliferation, which was not detected for omega-3. Both agents were able to prevent the anti-proliferative effect of H₂O₂, but only omega-3 prevented metabolic repression. Expression of heat shock protein 27 was unaltered by both fatty acids, whereas heat shock protein 90 was significantly induced by both. Omega-6 increased fibronectin and connective tissue growth factor synthesis, as well as the amount of secreted fibronectin. Omega-3, instead, induced plasminogen activator inhibitor 1 synthesis. H₂O₂ further increased fibronectin production in omega-6 supplemented cells, which was not the case in omega-3 treated cells. H₂O₂ stimulation of plasminogen activator inhibitor 1 and connective tissue growth factor was repressed by both fatty acids. Both fatty acids appeared to abolish H₂O₂ mediated stimulation of nuclear factor κB and IL-6, but not IL-1α and IL-8. H₂O₂ induced formation of cross-linked actin networks and stress fibers, which was reduced by preemptive application of omega-3. Omega-6, in contrast, had no protective effect on that, and even seemed to promote condensation. Based on the observed side

  15. Trabecular bone score as an assessment tool to identify the risk of osteoporosis in axial spondyloarthritis: a case-control study.

    Science.gov (United States)

    Kang, Kwi Young; Goo, Hye Yeon; Park, Sung-Hwan; Hong, Yeon Sik

    2018-03-01

    To compare the trabecular bone score (TBS) between patients with axial spondyloarthritis (axSpA) and matched normal controls and identify risk factors associated with a low TBS. TBS and BMD were assessed in the two groups (axSpA and control) using DXA. Osteoporosis risk factors and inflammatory markers were also assessed. Disease activity and radiographic progression in the sacroiliac joint and spine were evaluated in the axSpA group. Multivariate linear regression analysis was performed to identify risk factors associated with TBS. In the axSpA group, 248 subjects were enrolled; an equal number of age- and sex-matched subjects comprised the control group. The mean TBS was 1.43 (0.08) and 1.38 (0.12) in the control and axSpA groups, respectively (P tool to identify the risk of osteoporosis in patients with axSpA.

  16. Greater happiness for a greater number: Is that possible? If so how? (Arabic)

    NARCIS (Netherlands)

    R. Veenhoven (Ruut); E. Samuel (Emad)

    2012-01-01

    textabstractWhat is the final goal of public policy? Jeremy Bentham (1789) would say: greater happiness for a greater number. He thought of happiness as subjective enjoyment of life; in his words as “the sum of pleasures and pains”. In his time, the happiness of the great number could not be

  17. Tunneling Nanotubes are Novel Cellular Structures That Communicate Signals Between Trabecular Meshwork Cells.

    Science.gov (United States)

    Keller, Kate E; Bradley, John M; Sun, Ying Ying; Yang, Yong-Feng; Acott, Ted S

    2017-10-01

    The actin cytoskeleton of trabecular meshwork (TM) cells plays a role in regulating aqueous humor outflow. Many studies have investigated stress fibers, but F-actin also assembles into other supramolecular structures including filopodia. Recently, specialized filopodia called tunneling nanotubes (TNTs) have been described, which communicate molecular signals and organelles directly between cells. Here, we investigate TNT formation by TM cells. Human TM cells were labeled separately with the fluorescent dyes, DiO and DiD, or with mitochondrial dye. Fixed or live TM cells were imaged using confocal microscopy. Image analysis software was used to track fluorescent vesicles and count the number and length of filopodia. The number of fluorescently labeled vesicles transferred between cells was counted in response to specific inhibitors of the actin cytoskeleton. Human TM tissue was stained with phalloidin. Live-cell confocal imaging of cultured TM cells showed transfer of fluorescently labeled vesicles and mitochondria via TNTs. In TM tissue, a long (160 μm) actin-rich cell process bridged an intertrabecular space and did not adhere to the substratum. Treatment of TM cells with CK-666, an Arp2/3 inhibitor, significantly decreased the number and length of filopodia, decreased transfer of fluorescently labeled vesicles and induced thick stress fibers compared to vehicle control. Conversely, inhibiting stress fibers using Y27632 increased transfer of vesicles and induced long cell processes. Identification of TNTs provides a means by which TM cells can directly communicate with each other over long distances. This may be particularly important to overcome limitations of diffusion-based signaling in the aqueous humor fluid environment.

  18. Bmp2 in osteoblasts of periosteum and trabecular bone links bone formation to vascularization and mesenchymal stem cells

    Science.gov (United States)

    Yang, Wuchen; Guo, Dayong; Harris, Marie A.; Cui, Yong; Gluhak-Heinrich, Jelica; Wu, Junjie; Chen, Xiao-Dong; Skinner, Charles; Nyman, Jeffry S.; Edwards, James R.; Mundy, Gregory R.; Lichtler, Alex; Kream, Barbara E.; Rowe, David W.; Kalajzic, Ivo; David, Val; Quarles, Darryl L.; Villareal, Demetri; Scott, Greg; Ray, Manas; Liu, S.; Martin, James F.; Mishina, Yuji; Harris, Stephen E.

    2013-01-01

    Summary We generated a new Bmp2 conditional-knockout allele without a neo cassette that removes the Bmp2 gene from osteoblasts (Bmp2-cKOob) using the 3.6Col1a1-Cre transgenic model. Bones of Bmp2-cKOob mice are thinner, with increased brittleness. Osteoblast activity is reduced as reflected in a reduced bone formation rate and failure to differentiate to a mature mineralizing stage. Bmp2 in osteoblasts also indirectly controls angiogenesis in the periosteum and bone marrow. VegfA production is reduced in Bmp2-cKOob osteoblasts. Deletion of Bmp2 in osteoblasts also leads to defective mesenchymal stem cells (MSCs), which correlates with the reduced microvascular bed in the periosteum and trabecular bones. Expression of several MSC marker genes (α-SMA, CD146 and Angiopoietin-1) in vivo, in vitro CFU assays and deletion of Bmp2 in vitro in α-SMA+ MSCs support our conclusions. Critical roles of Bmp2 in osteoblasts and MSCs are a vital link between bone formation, vascularization and mesenchymal stem cells. PMID:23843612

  19. The assessment of Trabecular bone score to improve the sensitivity of FRAX in patients with type 2 diabetes mellitus

    Directory of Open Access Journals (Sweden)

    Tatiana O. Yalochkina

    2017-12-01

    Full Text Available Aim. To estimate the trabecular bone score (TBS for evaluation of fracture probability in order to make decisions about starting osteoporosis treatment in patients with type 2 diabetes mellitus (T2DM. Materials and methods. We obtained the bone mineral density (BMD and trabecular bone score (TBS using dual energy X-ray absorptiometry (iDXA in patients with T2DM (with and without a history of osteoporotic fractures versus the control group. Before and after TBS measurements we assessed the ten-year probability of fracture using the Fracture Risk Assessment Tool (FRAX. Results. We enrolled 48 patients with T2DM, including 17 with a history of low-traumatic fracture, 31 patients without fractures and 29 subjects of a control group. BMD was higher in patients with T2DM compared to the control group at L1–L4 (mean T-score 0.44, 95% CI -3.2 – 4.9 vs mean T-score 0.33, 95% CI -2.9 – 3.0 in a control group p=0.052 and Total Hip (mean T-score 0.51, 95% CI -2.1 – 3.0 vs mean T-score -0.03, 95% CI -1.4 – 1.2 in a control group p=0,025. The TBS and 10-year probability of fracture (FRAX was not different in patients with T2DM versus the control group. However, when the TBS was entered as an additional risk factor, the 10-year probability of fracture became higher in patients with T2DM (10-year probability of fracture in T2DM- 8.68, 95% CI 0.3-25.0 versus 6.68, 95% CI 0.4–15.0 in control group, p=0.04. Among patients with diabetes with and without fractures the FRAX score was higher in subjects with fractures, but no difference was found in regards to BMD or TBS. Entering BMD and TBS values into the FRAX tool in subjects with diabetes and fractures decreased the FRAX score. However, patients with low-traumatic fractures should be treated for osteoporosis without a BMD, TBS or FRAX assessment. Conclusion. TBS improves the results of FRAX assessment in patients with T2DM and should be entered while evaluating FRAX in patients with T2DM. However

  20. Differential Canalograms Detect Outflow Changes from Trabecular Micro-Bypass Stents and Ab Interno Trabeculectomy.

    Science.gov (United States)

    Parikh, Hardik A; Loewen, Ralitsa T; Roy, Pritha; Schuman, Joel S; Lathrop, Kira L; Loewen, Nils A

    2016-11-04

    Recently introduced microincisional glaucoma surgeries that enhance conventional outflow offer a favorable risk profile over traditional surgeries, but can be unpredictable. Two paramount challenges are the lack of an adequate training model for angle surgeries and the absence of an intraoperative quantification of surgical success. To address both, we developed an ex vivo training system and a differential, quantitative canalography method that uses slope-adjusted fluorescence intensities of two different chromophores to avoid quenching. We assessed outflow enhancement by trabecular micro-bypass (TMB) implantation or by ab interno trabeculectomy (AIT). In this porcine model, TMB resulted in an insignificant (p > 0.05) outflow increase of 13 ± 5%, 14 ± 8%, 9 ± 3%, and 24 ± 9% in the inferonasal, superonasal, superotemporal, and inferotemporal quadrant, respectively. AIT caused a 100 ± 50% (p = 0.002), 75 ± 28% (p = 0.002), 19 ± 8%, and 40 ± 21% increase in those quadrants. The direct gonioscopy and tactile feedback provided a surgical experience that was very similar to that in human patients. Despite the more narrow and discontinuous circumferential drainage elements in the pig with potential for underperformance or partial stent obstruction, unequivocal patterns of focal outflow enhancement by TMB were seen in this training model. AIT achieved extensive access to outflow pathways beyond the surgical site itself.

  1. Variation in primary and culture-expanded cells derived from connective tissue progenitors in human bone marrow space, bone trabecular surface and adipose tissue.

    Science.gov (United States)

    Qadan, Maha A; Piuzzi, Nicolas S; Boehm, Cynthia; Bova, Wesley; Moos, Malcolm; Midura, Ronald J; Hascall, Vincent C; Malcuit, Christopher; Muschler, George F

    2018-03-01

    Connective tissue progenitors (CTPs) embody the heterogeneous stem and progenitor cell populations present in native tissue. CTPs are essential to the formation and remodeling of connective tissue and represent key targets for tissue-engineering and cell-based therapies. To better understand and characterize CTPs, we aimed to compare the (i) concentration and prevalence, (ii) early in vitro biological behavior and (iii) expression of surface-markers and transcription factors among cells derived from marrow space (MS), trabecular surface (TS), and adipose tissues (AT). Cancellous-bone and subcutaneous-adipose tissues were collected from 8 patients. Cells were isolated and cultured. Colony formation was assayed using Colonyze software based on ASTM standards. Cell concentration ([Cell]), CTP concentration ([CTP]) and CTP prevalence (P CTP ) were determined. Attributes of culture-expanded cells were compared based on (i) effective proliferation rate and (ii) expression of surface-markers CD73, CD90, CD105, SSEA-4, SSEA-3, SSEA-1/CD15, Cripto-1, E-Cadherin/CD324, Ep-CAM/CD326, CD146, hyaluronan and transcription factors Oct3/4, Sox-2 and Nanog using flow cytometry. Mean [Cell], [CTP] and P CTP were significantly different between MS and TS samples (P = 0.03, P = 0.008 and P= 0.0003), respectively. AT-derived cells generated the highest mean total cell yield at day 6 of culture-4-fold greater than TS and more than 40-fold greater than MS per million cells plated. TS colonies grew with higher mean density than MS colonies (290 ± 11 versus 150 ± 11 cell per mm 2 ; P = 0.0002). Expression of classical-mesenchymal stromal cell (MSC) markers was consistently recorded (>95%) from all tissue sources, whereas all the other markers were highly variable. The prevalence and biological potential of CTPs are different between patients and tissue sources and lack variation in classical MSC markers. Other markers are more likely to discriminate differences

  2. Strength through structure: visualization and local assessment of the trabecular bone structure

    International Nuclear Information System (INIS)

    Raeth, C; Monetti, R; Bauer, J; Sidorenko, I; Mueller, D; Matsuura, M; Lochmueller, E-M; Zysset, P; Eckstein, F

    2008-01-01

    The visualization and subsequent assessment of the inner human bone structures play an important role for better understanding the disease- or drug-induced changes of bone in the context of osteoporosis giving prospect for better predictions of bone strength and thus of the fracture risk of osteoporotic patients. In this work, we show how the complex trabecular bone structure can be visualized using μCT imaging techniques at an isotropic resolution of 26 μm. We quantify these structures by calculating global and local topological and morphological measures, namely Minkowski functionals (MFs) and utilizing the (an-)isotropic scaling index method (SIM) and by deriving suitable texture measures based on MF and SIM. Using a sample of 151 specimens taken from human vertebrae in vitro, we correlate the texture measures with the mechanically measured maximum compressive strength (MCS), which quantifies the strength of the bone probe, by using Pearson's correlation coefficient. The structure parameters derived from the local measures yield good correlations with the bone strength as measured in mechanical tests. We investigate whether the performance of the texture measures depends on the MCS value by selecting different subsamples according to MCS. Considering the whole sample the results for the newly defined parameters are better than those obtained for the standard global histomorphometric parameters except for bone volume/total volume (BV/TV). If a subsample consisting only of weak bones is analysed, the local structural analysis leads to similar and even better correlations with MCS as compared to BV/TV. Thus, the MF and SIM yield additional information about the stability of the bone especially in the case of weak bones, which corroborates the hypothesis that the bone structure (and not only its mineral mass) constitutes an important component of bone stability.

  3. Is trabecular bone permeability governed by molecular ordering-induced fluid viscosity gain? Arguments from re-evaluation of experimental data in the framework of homogenization theory.

    Science.gov (United States)

    Abdalrahman, T; Scheiner, S; Hellmich, C

    2015-01-21

    It is generally agreed on that trabecular bone permeability, a physiologically important quantity, is governed by the material׳s (vascular or intertrabecular) porosity as well as by the viscosity of the pore-filling fluids. Still, there is less agreement on how these two key factors govern bone permeability. In order to shed more light onto this somewhat open issue, we here develop a random homogenization scheme for upscaling Poiseuille flow in the vascular porosity, up to Darcy-type permeability of the overall porous medium "trabecular bone". The underlying representative volume element of the macroscopic bone material contains two types of phases: a spherical, impermeable extracellular bone matrix phase interacts with interpenetrating cylindrical pore channel phases that are oriented in all different space directions. This type of interaction is modeled by means of a self-consistent homogenization scheme. While the permeability of the bone matrix equals to zero, the permeability of the pore phase is found through expressing the classical Hagen-Poiseuille law for laminar flow in the format of a "micro-Darcy law". The upscaling scheme contains pore size and porosity as geometrical input variables; however, they can be related to each other, based on well-known relations between porosity and specific bone surface. As two key results, validated through comprehensive experimental data, it appears (i) that the famous Kozeny-Carman constant (which relates bone permeability to the cube of the porosity, the square of the specific surface, as well as to the bone fluid viscosity) needs to be replaced by an again porosity-dependent rational function, and (ii) that the overall bone permeability is strongly affected by the pore fluid viscosity, which, in case of polarized fluids, is strongly increased due to the presence of electrically charged pore walls. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Inhibition of Rho Kinase Induces Antioxidative Molecules and Suppresses Reactive Oxidative Species in Trabecular Meshwork Cells

    Directory of Open Access Journals (Sweden)

    Tomokazu Fujimoto

    2017-01-01

    Full Text Available Purpose. To investigate the effect of rho kinase inhibitors on oxidative stress in trabecular meshwork (TM cells. Methods. TM cells were isolated from the eyes of cynomolgus monkeys. Y-27632 and menadione were used to inhibit rho kinase and induce production of reactive oxygen species (ROS, respectively. The cynomolgus monkey array and 12,613 probes were used in DNA microarray analysis, and the affected genes were categorized using gene ontology analysis. The mRNA levels of the target genes were confirmed by real-time RT-PCR. Intracellular oxidative stress was detected using a fluorescent reagent sensitive to ROS. Cell viability was assessed by the WST-8 assay. Results. Gene ontology analysis revealed upregulation of genes involved in antioxidant activity, and upregulation of catalase was confirmed by real-time RT-PCR after 30 min treatment with Y-27632. Production of ROS was increased by menadione, and the effect was partly suppressed by pretreatment with Y-27632. At a lower dose of menadione, Y-27632 stimulated TM cells and significantly increased their viability following menadione treatment compared to control cells. Conclusion. Using microarray analysis, Y-27632 was shown to upregulate antioxidative genes including catalase and partially reduce ROS production and cell death by oxidative stress caused by menadione.

  5. Bone microarchitecture and estimated bone strength in men with active acromegaly.

    Science.gov (United States)

    Silva, Paula P B; Amlashi, Fatemeh G; Yu, Elaine W; Pulaski-Liebert, Karen J; Gerweck, Anu V; Fazeli, Pouneh K; Lawson, Elizabeth; Nachtigall, Lisa B; Biller, Beverly M K; Miller, Karen K; Klibanski, Anne; Bouxsein, Mary; Tritos, Nicholas A

    2017-11-01

    Both acromegaly and adult growth hormone deficiency (GHD) are associated with increased fracture risk. Sufficient data are lacking regarding cortical bone microarchitecture and bone strength, as assessed by microfinite element analysis (µFEA). To elucidate both cortical and trabecular bone microarchitecture and estimated bone strength in men with active acromegaly or GHD compared to healthy controls. Cross-sectional study at a clinical research center, including 48 men (16 with acromegaly, 16 with GHD and 16 healthy controls). Areal bone mineral density (aBMD), cortical and trabecular bone microarchitecture and estimated bone strength (µFEA) at the radius and tibia. aBMD was not different between the 3 groups at any skeletal site. At the radius, patients with acromegaly had greater cortical area ( P  acromegaly had lower trabecular bone density ( P  = 0.0082), but no differences in cortical bone microstructure. Compressive strength and failure load did not significantly differ between groups. These findings persisted after excluding patients with hypogonadism. Bone microarchitecture was not deficient in patients with GHD. Both cortical and trabecular microarchitecture are altered in men with acromegaly. Our data indicate that GH excess is associated with distinct effects in cortical vs trabecular bone compartments. Our observations also affirm the limitations of aBMD testing in the evaluation of patients with acromegaly. © 2017 European Society of Endocrinology.

  6. A signature dissimilarity measure for trabecular bone texture in knee radiographs

    International Nuclear Information System (INIS)

    Woloszynski, T.; Podsiadlo, P.; Stachowiak, G. W.; Kurzynski, M.

    2010-01-01

    Purpose: The purpose of this study is to develop a dissimilarity measure for the classification of trabecular bone (TB) texture in knee radiographs. Problems associated with the traditional extraction and selection of texture features and with the invariance to imaging conditions such as image size, anisotropy, noise, blur, exposure, magnification, and projection angle were addressed. Methods: In the method developed, called a signature dissimilarity measure (SDM), a sum of earth mover's distances calculated for roughness and orientation signatures is used to quantify dissimilarities between textures. Scale-space theory was used to ensure scale and rotation invariance. The effects of image size, anisotropy, noise, and blur on the SDM developed were studied using computer generated fractal texture images. The invariance of the measure to image exposure, magnification, and projection angle was studied using x-ray images of human tibia head. For the studies, Mann-Whitney tests with significance level of 0.01 were used. A comparison study between the performances of a SDM based classification system and other two systems in the classification of Brodatz textures and the detection of knee osteoarthritis (OA) were conducted. The other systems are based on weighted neighbor distance using compound hierarchy of algorithms representing morphology (WND-CHARM) and local binary patterns (LBP). Results: Results obtained indicate that the SDM developed is invariant to image exposure (2.5-30 mA s), magnification (x1.00-x1.35), noise associated with film graininess and quantum mottle ( 64x64 pixels). However, the measure is sensitive to changes in projection angle (>5 deg.), image anisotropy (>30 deg.), and blur generated by a regular film screen. For the classification of Brodatz textures, the SDM based system produced comparable results to the LBP system. For the detection of knee OA, the SDM based system achieved 78.8% classification accuracy and outperformed the WND

  7. Association of Insulin Resistance with Bone Strength and Bone Turnover in Menopausal Chinese-Singaporean Women without Diabetes

    Science.gov (United States)

    Kalimeri, Maria; Leek, Francesca; Wang, Nan Xin; Koh, Huann Rong; Totman, John J.

    2018-01-01

    Insulin resistance (IR) is accompanied by increased areal or volumetric bone mineral density (aBMD or vBMD), but also higher fracture risk. Meanwhile, imbalances in bone health biomarkers affect insulin production. This study investigates the effect of IR on proximal femur and lumbar spine BMD, femoral neck bending, compressive and impact strength indices (Composite Strength Indices) and circulating levels of parathyroid hormone (PTH), C-telopeptide of Type I collagen (CTx-1) and 25(OH) Vitamin D3, in a cohort of 97 healthy, non-obese, menopausal Chinese-Singaporean women. Lumbar spine aBMD was inversely associated with IR and dependent on lean body mass (LBM) and age. No such associations were found for vBMD of the third lumbar vertebra, aBMD and vBMD of the proximal femur, or circulating levels of PTH, CTx-1 and 25(OH) Vitamin D3. Composite Strength Indices were inversely associated with IR and independent of LBM, but after adjusting for fat mass and age, this association remained valid only for the impact strength index. Composite Strength Indices were significantly lower in participants with a high degree of IR. Our findings on IR and Composite Strength Indices relationships were in agreement with previous studies on different cohorts, but those on IR and BMD associations were not. PMID:29710852

  8. Association of Insulin Resistance with Bone Strength and Bone Turnover in Menopausal Chinese-Singaporean Women without Diabetes

    Directory of Open Access Journals (Sweden)

    Maria Kalimeri

    2018-04-01

    Full Text Available Insulin resistance (IR is accompanied by increased areal or volumetric bone mineral density (aBMD or vBMD, but also higher fracture risk. Meanwhile, imbalances in bone health biomarkers affect insulin production. This study investigates the effect of IR on proximal femur and lumbar spine BMD, femoral neck bending, compressive and impact strength indices (Composite Strength Indices and circulating levels of parathyroid hormone (PTH, C-telopeptide of Type I collagen (CTx-1 and 25(OH Vitamin D3, in a cohort of 97 healthy, non-obese, menopausal Chinese-Singaporean women. Lumbar spine aBMD was inversely associated with IR and dependent on lean body mass (LBM and age. No such associations were found for vBMD of the third lumbar vertebra, aBMD and vBMD of the proximal femur, or circulating levels of PTH, CTx-1 and 25(OH Vitamin D3. Composite Strength Indices were inversely associated with IR and independent of LBM, but after adjusting for fat mass and age, this association remained valid only for the impact strength index. Composite Strength Indices were significantly lower in participants with a high degree of IR. Our findings on IR and Composite Strength Indices relationships were in agreement with previous studies on different cohorts, but those on IR and BMD associations were not.

  9. Directional fractal signature methods for trabecular bone texture in hand radiographs: Data from the Osteoarthritis Initiative

    International Nuclear Information System (INIS)

    Wolski, M.; Podsiadlo, P.; Stachowiak, G. W.

    2014-01-01

    Purpose: To develop directional fractal signature methods for the analysis of trabecular bone (TB) texture in hand radiographs. Problems associated with the small size of hand bones and the orientation of fingers were addressed. Methods: An augmented variance orientation transform (AVOT) and a quadrant rotating grid (QRG) methods were developed. The methods calculate fractal signatures (FSs) in different directions. Unlike other methods they have the search region adjusted according to the size of bone region of interest (ROI) to be analyzed and they produce FSs defined with respect to any chosen reference direction, i.e., they work for arbitrary orientation of fingers. Five parameters at scales ranging from 2 to 14 pixels (depending on image size and method) were derived from rose plots of Hurst coefficients, i.e., FS in dominating roughness (FS Sta ), vertical (FS V ) and horizontal (FS H ) directions, aspect ratio (StrS), and direction signatures (StdS), respectively. The accuracy in measuring surface roughness and isotropy/anisotropy was evaluated using 3600 isotropic and 800 anisotropic fractal surface images of sizes between 20 × 20 and 64 × 64 pixels. The isotropic surfaces had FDs ranging from 2.1 to 2.9 in steps of 0.1, and the anisotropic surfaces had two dominating directions of 30° and 120°. The methods were used to find differences in hand TB textures between 20 matched pairs of subjects with (cases: approximate Kellgren-Lawrence (KL) grade ≥2) and without (controls: approximate KL grade <2) radiographic hand osteoarthritis (OA). The OA Initiative public database was used and 20 × 20 pixel bone ROIs were selected on 5th distal and middle phalanges. The performance of the AVOT and QRG methods was compared against a variance orientation transform (VOT) method developed earlier [M. Wolski, P. Podsiadlo, and G. W. Stachowiak, “Directional fractal signature analysis of trabecular bone: evaluation of different methods to detect early osteoarthritis

  10. On exposure to anorexia nervosa, the temporal variation in axial and appendicular skeletal development predisposes to site-specific deficits in bone size and density: a cross-sectional study.

    Science.gov (United States)

    Seeman, E; Karlsson, M K; Duan, Y

    2000-11-01

    Skeletal development is heterogeneous. Throughout growth, bone size is more maturationally advanced than the mineral being accrued within its periosteal envelope; before puberty, appendicular growth is more rapid than axial growth; during puberty, appendicular growth slows and axial growth accelerates. We studied women with differing age of onset of anorexia nervosa to determine whether this temporal heterogeneity in growth predisposed to the development of deficits in bone size and volumetric bone mineral density (vBMD), which varied by site and severity depending on the age at which anorexia nervosa occurred. Bone size and vBMD of the third lumbar vertebra and femoral neck were measured using dual-energy X-ray absorptiometry in 210 women aged 21 years (range, 12-40 years) with anorexia nervosa. Results were expressed as age-specific SDs (mean +/- SEM). Bone width depended on the age of onset of anorexia nervosa; when the onset of anorexia nervosa occurred (1) before 15 years of age, deficits in vertebral body and femoral neck width did not differ (-0.77+/-0.27 SD and -0.55+/-0.17 SD, respectively); (2) between 15 and 19 years of age, deficits in vertebral body width (-0.95+/-0.16 SD) were three times the deficits in femoral neck width (-0.28+/-0.14 SD; p anorexia nervosa. No deficit in bone width was observed at the femoral neck. Deficits in vBMD at the vertebra and femoral neck were independent of the age of onset of anorexia nervosa but increased as the duration of anorexia nervosa increased, being about 0.5 SD lower at the vertebra than femoral neck. We infer that the maturational development of a region at the time of exposure to disease, and disease duration, determine the site, magnitude, and type of trait deficit in anorexia nervosa. Bone fragility due to reduced bone size and reduced vBMD in adulthood is partly established during growth.

  11. Prospective, randomized study of one, two, or three trabecular bypass stents in open-angle glaucoma subjects on topical hypotensive medication

    Directory of Open Access Journals (Sweden)

    Katz LJ

    2015-12-01

    Full Text Available L Jay Katz,1 Carl Erb,2 Amadeu Carceller Guillamet,3 Antonio M Fea,4 Lilit Voskanyan,5 Jeffrey M Wells,6 Jane Ellen Giamporcaro6 1Wills Eye Hospital, Jefferson Medical College, Philadelphia, PA, USA; 2Eye Clinic Wittenbergplatz, Berlin, Germany; 3Department of Ophthalmology, Hospital d’Hebron, Barcelona, Spain; 4University Eye Clinic of the University of Turin, Turin, Italy; 5SV Malayan Opthalmology Centre, Yerevan, Armenia; 6Glaukos Corporation, Laguna Hills, CA, USA Purpose: To assess the safety and efficacy of one, two, or three trabecular microbypass stents in eyes with primary open-angle glaucoma (OAG not controlled on ocular hypotensive medication. A total of 119 subjects were followed for 18 months postoperatively.Materials and methods: Subjects with medicated intraocular pressure (IOP 18–30 mmHg and postmedication-washout baseline IOP 22–38 mmHg were randomized to implantation of one, two, or three stents. Ocular hypotensive medication was to be used if postoperative IOP exceeded 18 mmHg.Results: A total of 38 subjects were implanted with one stent, 41 subjects with two stents, and 40 subjects with three stents. Both month 12 IOP reduction ≥20% without ocular hypotensive medication vs baseline unmedicated IOP and month 12 unmedicated IOP ≤18 mmHg were achieved by 89.2%, 90.2%, and 92.1% of one-, two-, and three-stent eyes, respectively. Furthermore, 64.9%, 85.4%, and 92.1% of the three respective groups achieved unmedicated IOP ≤15 mmHg. Over the 18-month follow-up period, medication was required in seven one-stent subjects, four two-stent subjects, and three three-stent subjects. At 18 months, mean unmedicated IOP was 15.9±0.9 mmHg in one-stent subjects, 14.1±1.0 mmHg in two-stent subjects, and 12.2±1.1 mmHg in three-stent subjects. Month 18 IOP reduction was significantly greater (P<0.001 with implantation of each additional stent, with mean differences in reduction of 1.84 mmHg (95% confidence interval 0.96

  12. In Vivo Over-expression of Circulating Dlk1/Pref-1 Protein Using Hydrodynamic-based Gene Transfer Leads to Lower Bone mass With Marked Effects on Trabecular Bone Micro-architecture

    DEFF Research Database (Denmark)

    Ding, Ming

    determined by PIXImus (LunarR) and micro-CT (ScancoR) respectively. We could only localize the plasmid in the liver and no complications were detected due to transgene expression. Serum levels of FA1 in Dlk1 injected mice (Dlk1+mice) was elevated by more than 15 folds compared to control saline injected mice...... and BMD was negatively correlated with the circulating levels of FA1. Micro-CT analysis revealed significantly decreased micro-architectural parameters of trabecular bone in the distal femur and proximal tibia of the Dlk1+mice compared to controls (see table). Naked DNA delivery by hydrodynamic injection...

  13. Effects of genes, sex, age, and activity on BMC, bone size, and areal and volumetric BMD.

    Science.gov (United States)

    Havill, Lorena M; Mahaney, Michael C; L Binkley, Teresa; Specker, Bonny L

    2007-05-01

    Quantitative genetic analyses of bone data for 710 inter-related individuals 8-85 yr of age found high heritability estimates for BMC, bone area, and areal and volumetric BMD that varied across bone sites. Activity levels, especially time in moderate plus vigorous activity, had notable effects on bone. In some cases, these effects were age and sex specific. Genetic and environmental factors play a complex role in determining BMC, bone size, and BMD. This study assessed the heritability of bone measures; characterized the effects of age, sex, and physical activity on bone; and tested for age- and sex-specific bone effects of activity. Measures of bone size and areal and volumetric density (aBMD and vBMD, respectively) were obtained by DXA and pQCT on 710 related individuals (466 women) 8-85 yr of age. Measures of activity included percent time in moderate + vigorous activity (%ModVig), stair flights climbed per day, and miles walked per day. Quantitative genetic analyses were conducted to model the effects of activity and covariates on bone outcomes. Accounting for effects of age, sex, and activity levels, genes explained 40-62% of the residual variation in BMC and BMD and 27-75% in bone size (all pBMC and cross-sectional area (CSA) at the 4% radius, but this was not observed among women (sex-by-activity interaction, both p greater cortical vBMD (Cort-vBMD) than younger men, with minimal difference between low and high activity levels. Influence of activity was greater in older women: older women with low activity had lower Cort-vBMD than older men, but older women with high activity had higher Cort-vBMD than older men (age-by-sex-by-activity interaction, p=0.04). High heritability estimates for DXA and pQCT measures varied across bone sites. Percent time spent in moderate to vigorous activity had the most notable effect on bone, and in some cases, this effect was age or sex specific.

  14. A novel method for quantifying the amount of trabecular meshwork pigment in glaucomatous and nonglaucomatous eyes.

    Science.gov (United States)

    Kinori, Michael; Hostovsky, Avner; Skaat, Alon; Schwartsman, Jonathan; Melamed, Shlomo

    2014-01-01

    To assess the use of a computerized program for evaluating the amount of trabecular meshwork (TM) pigmentation in normal (control), primary open-angle glaucoma (POAG), and pseudoexfoliation glaucoma/pigmentary dispersion glaucoma (PXFG/PDG) patients. All included patients were from the Goldschleger Eye Institute glaucoma clinic. After signing an informed consent, each patient's anterior chamber angle was photographed using a single photo-slit under the same conditions. Only one eye per patient was photographed. The superior TM and the inferior TM were documented. Then, the degree of "blackness" (representing melanin pigment) was assessed using the ImageJ program. Of the 43 eyes photographed, 8 were excluded because of low-quality images. Of the remaining 35 patients, 14 were normal, 10 had POAG, and 11 had PXFG/PDG. The amount of pigment was the same in the control and the POAG patients whether the inferior TM (P=0.24), superior TM (P=0.58), or the sum inferior TM+superior TM (P=0.85) was measured. The pigment level was significantly higher in the PXFG/PDG group than in the control group (inferior TM, Ppigment levels was found to be statistically insignificant in all the groups (normal, P=0.86; POAG, P=0.10; PXFG/PDG, P=0.22). The use of ImageJ software might play a role in the quantification of pigment evaluation of the TM.

  15. Microdistribution and local dosimetry of 226Ra in trabecular bone of the beagle

    International Nuclear Information System (INIS)

    Polig, E.; Jee, W.S.; Dell, R.B.; Johnson, F.

    1988-01-01

    Sections of lumbar vertebral bodies of young adult beagle dogs have been analyzed autoradiographically to characterize and quantify the local distribution of 226Ra by means of a scanning microscope photometer. The animals received a single injection of 355 kBq/kg body weight and were serially sacrificed at 5 to 1381 days postinjection. Hotspot concentrations decreased from about 51 kBq/g bone at 5 days to 20 kBq/g at 1381 days postinjection. The diffuse concentration changed from 8.3 to 1.9 kBq/g. The mean 226Ra concentration in the trabecular areas scanned was initially higher and at the end of the observation period lower than the average calculated for the whole lumbar vertebral column. Density and area of, and fraction of bone activity in, hotspots virtually remained constant. With time hotspots tended to become translocated into bone volume. Mean dose rates to lining cells from both hotspots and diffuse labels decreased from about 210 mGy/d at early postinjection times to 105 mGy/d. This corresponds to 2.5 to 1.1 times the average skeletal dose rate. A discussion of the level of irradiation in terms of hit frequencies shows that osteoblasts in the initial phase of hotspot formation receive about 60 hits to their nucleus for the duration of bone formation. After about 6 months, however, the 226Ra concentration in new bone and the corresponding hit frequency appears to be low enough that interference with bone formation is unlikely. Morphometric measurements showed that abnormal bone accretion and thickening of trabeculae occurred. This was interpreted as an imbalance between bone formation and resorption. Both formation and resorption seem to be substantially lowered compared to control animals

  16. A prospective 3-year follow-up trial of implantation of two trabecular microbypass stents in open-angle glaucoma

    Directory of Open Access Journals (Sweden)

    Donnenfeld ED

    2015-11-01

    Full Text Available Eric D Donnenfeld,1 Kerry D Solomon,2 Lilit Voskanyan,3 David F Chang,4 Thomas W Samuelson,5 Iqbal Ike K Ahmed,6 L Jay Katz7 1Ophthalmic Consultants of Long Island, Rockville Centre, NY, 2Carolina Eyecare Physicians, Mt Pleasant, SC, USA; 3S.V. Malayan Ophthalmology Centre, Yerevan, Armenia; 4Altos Eye Physicians, Los Altos, CA, 5Minnesota Eye Consultants, Minneapolis, MN, USA; 6University of Toronto, Toronto, ON, Canada; 7Wills Eye Hospital, Jefferson Medical College, Philadelphia, PA, USA Purpose: To evaluate 3-year safety and intraocular pressure (IOP following two trabecular microbypass stents in phakic and pseudophakic subjects with open-angle glaucoma (OAG not controlled on preoperative medication. Patients and methods: In this prospective pilot study, phakic or pseudophakic subjects with OAG and IOP between 18 mmHg and 30 mmHg on one preoperative topical ocular hypotensive medication underwent medication washout. Thirty-nine qualified subjects with preoperative unmedicated IOP ≥22 mmHg and ≤38 mmHg received two stents. Postoperative examinations were scheduled at Day 1, Week 1, Months 1, 3, 6, and 12, and semiannually through Month 60. Ocular hypotensive medication was considered if postoperative IOP exceeded 21 mmHg. IOP, medication use, and safety were assessed at each visit. Subject follow-up through Month 36 was completed. Results: Thirty-six eyes (92.3%; 95% confidence interval [CI] 79.1%, 98.4% achieved the primary efficacy end point of Month 12 reduction in IOP ≥20% from baseline (unmedicated IOP without ocular hypotensive medication. Four subjects required medication during the Month 36 follow-up period. Mean IOP at 36 months for subjects not taking medication was 15.2 mmHg. At 36 months, subjects sustained mean IOP decrease of 9.1±2.7 mmHg (95% CI 8.0 mmHg, 10.14 mmHg, or 37% IOP reduction, from unmedicated baseline IOP. Compared to preoperative medicated IOP, subjects had mean reduction at Month 36 of 5.5±2

  17. Greater-confinement disposal

    International Nuclear Information System (INIS)

    Trevorrow, L.E.; Schubert, J.P.

    1989-01-01

    Greater-confinement disposal (GCD) is a general term for low-level waste (LLW) disposal technologies that employ natural and/or engineered barriers and provide a degree of confinement greater than that of shallow-land burial (SLB) but possibly less than that of a geologic repository. Thus GCD is associated with lower risk/hazard ratios than SLB. Although any number of disposal technologies might satisfy the definition of GCD, eight have been selected for consideration in this discussion. These technologies include: (1) earth-covered tumuli, (2) concrete structures, both above and below grade, (3) deep trenches, (4) augered shafts, (5) rock cavities, (6) abandoned mines, (7) high-integrity containers, and (8) hydrofracture. Each of these technologies employ several operations that are mature,however, some are at more advanced stages of development and demonstration than others. Each is defined and further described by information on design, advantages and disadvantages, special equipment requirements, and characteristic operations such as construction, waste emplacement, and closure

  18. A signature dissimilarity measure for trabecular bone texture in knee radiographs

    Energy Technology Data Exchange (ETDEWEB)

    Woloszynski, T.; Podsiadlo, P.; Stachowiak, G. W.; Kurzynski, M. [Tribology Laboratory, School of Mechanical Engineering, University of Western Australia, Crawley, Western Australia 6009 (Australia); Chair of Computer Systems and Networks, Faculty of Electronics, Wroclaw University of Technology, Wybrzeze Wyspianskiego 27, 50-370 Wroclaw (Poland)

    2010-05-15

    Purpose: The purpose of this study is to develop a dissimilarity measure for the classification of trabecular bone (TB) texture in knee radiographs. Problems associated with the traditional extraction and selection of texture features and with the invariance to imaging conditions such as image size, anisotropy, noise, blur, exposure, magnification, and projection angle were addressed. Methods: In the method developed, called a signature dissimilarity measure (SDM), a sum of earth mover's distances calculated for roughness and orientation signatures is used to quantify dissimilarities between textures. Scale-space theory was used to ensure scale and rotation invariance. The effects of image size, anisotropy, noise, and blur on the SDM developed were studied using computer generated fractal texture images. The invariance of the measure to image exposure, magnification, and projection angle was studied using x-ray images of human tibia head. For the studies, Mann-Whitney tests with significance level of 0.01 were used. A comparison study between the performances of a SDM based classification system and other two systems in the classification of Brodatz textures and the detection of knee osteoarthritis (OA) were conducted. The other systems are based on weighted neighbor distance using compound hierarchy of algorithms representing morphology (WND-CHARM) and local binary patterns (LBP). Results: Results obtained indicate that the SDM developed is invariant to image exposure (2.5-30 mA s), magnification (x1.00-x1.35), noise associated with film graininess and quantum mottle (<25%), blur generated by a sharp film screen, and image size (>64x64 pixels). However, the measure is sensitive to changes in projection angle (>5 deg.), image anisotropy (>30 deg.), and blur generated by a regular film screen. For the classification of Brodatz textures, the SDM based system produced comparable results to the LBP system. For the detection of knee OA, the SDM based system

  19. Directional fractal signature methods for trabecular bone texture in hand radiographs: Data from the Osteoarthritis Initiative

    Energy Technology Data Exchange (ETDEWEB)

    Wolski, M., E-mail: marcin.wolski@curtin.edu.au; Podsiadlo, P.; Stachowiak, G. W. [Tribology Laboratory, School of Civil and Mechanical Engineering, Curtin University, Bentley, Western Australia 6102 (Australia)

    2014-08-15

    Purpose: To develop directional fractal signature methods for the analysis of trabecular bone (TB) texture in hand radiographs. Problems associated with the small size of hand bones and the orientation of fingers were addressed. Methods: An augmented variance orientation transform (AVOT) and a quadrant rotating grid (QRG) methods were developed. The methods calculate fractal signatures (FSs) in different directions. Unlike other methods they have the search region adjusted according to the size of bone region of interest (ROI) to be analyzed and they produce FSs defined with respect to any chosen reference direction, i.e., they work for arbitrary orientation of fingers. Five parameters at scales ranging from 2 to 14 pixels (depending on image size and method) were derived from rose plots of Hurst coefficients, i.e., FS in dominating roughness (FS{sub Sta}), vertical (FS{sub V}) and horizontal (FS{sub H}) directions, aspect ratio (StrS), and direction signatures (StdS), respectively. The accuracy in measuring surface roughness and isotropy/anisotropy was evaluated using 3600 isotropic and 800 anisotropic fractal surface images of sizes between 20 × 20 and 64 × 64 pixels. The isotropic surfaces had FDs ranging from 2.1 to 2.9 in steps of 0.1, and the anisotropic surfaces had two dominating directions of 30° and 120°. The methods were used to find differences in hand TB textures between 20 matched pairs of subjects with (cases: approximate Kellgren-Lawrence (KL) grade ≥2) and without (controls: approximate KL grade <2) radiographic hand osteoarthritis (OA). The OA Initiative public database was used and 20 × 20 pixel bone ROIs were selected on 5th distal and middle phalanges. The performance of the AVOT and QRG methods was compared against a variance orientation transform (VOT) method developed earlier [M. Wolski, P. Podsiadlo, and G. W. Stachowiak, “Directional fractal signature analysis of trabecular bone: evaluation of different methods to detect early

  20. Tamoxifen-inducible gene deletion reveals a distinct cell type associated with trabecular bone, and direct regulation of PTHrP expression and chondrocyte morphology by Ihh in growth region cartilage.

    Science.gov (United States)

    Hilton, Matthew J; Tu, Xiaolin; Long, Fanxin

    2007-08-01

    Indian hedgehog (Ihh) controls multiple aspects of endochondral skeletal development by signaling to both chondrocytes and perichondrial cells. Previous efforts to delineate direct effects of Ihh on chondrocytes by Col2-Cre-mediated ablation of Smoothened (Smo, encoding a transmembrane protein indispensable for Ihh signaling) has been only partially successful, due to the inability to discriminate between chondrocytes and perichondrial cells. Here we report a transgenic line (Col2-Cre) expressing under the control of the Colalpha1(II) promoter an inert form of Cre that is activatable by exogenous tamoxifen (TM); TM administration at proper times during embryogenesis induced Cre activity in chondrocytes but not in the perichondrium. By using this mouse line, we deleted Smo within subsets of chondrocytes without affecting the perichondrium and found that Smo removal led to localized disruption of the expression of parathyroid hormone-related protein (PTHrP) and the morphology of chondrocytes. Unexpectedly, TM invariably induced Cre activity in a subset of cells associated with the trabecular bone surface of long bones. These cells, when genetically marked and cultured in vitro, were capable of producing bone nodules. Expression of the Col2-Cre transgene in these cells likely reflected the endogenous Colalpha1(II) promoter activity as similar cells were found to express the IIA isoform of Colalpha1(II) mRNA endogenously. In summary, the present study has not only provided evidence that Ihh signaling directly controls PTHrP expression and chondrocyte morphology in the growth region cartilage, but has also uncovered a distinct cell type associated with the trabecular bone that appears to possess osteogenic potential.

  1. Phantom-less bone mineral density (BMD) measurement using dual energy computed tomography-based 3-material decomposition

    Science.gov (United States)

    Hofmann, Philipp; Sedlmair, Martin; Krauss, Bernhard; Wichmann, Julian L.; Bauer, Ralf W.; Flohr, Thomas G.; Mahnken, Andreas H.

    2016-03-01

    Osteoporosis is a degenerative bone disease usually diagnosed at the manifestation of fragility fractures, which severely endanger the health of especially the elderly. To ensure timely therapeutic countermeasures, noninvasive and widely applicable diagnostic methods are required. Currently the primary quantifiable indicator for bone stability, bone mineral density (BMD), is obtained either by DEXA (Dual-energy X-ray absorptiometry) or qCT (quantitative CT). Both have respective advantages and disadvantages, with DEXA being considered as gold standard. For timely diagnosis of osteoporosis, another CT-based method is presented. A Dual Energy CT reconstruction workflow is being developed to evaluate BMD by evaluating lumbar spine (L1-L4) DE-CT images. The workflow is ROI-based and automated for practical use. A dual energy 3-material decomposition algorithm is used to differentiate bone from soft tissue and fat attenuation. The algorithm uses material attenuation coefficients on different beam energy levels. The bone fraction of the three different tissues is used to calculate the amount of hydroxylapatite in the trabecular bone of the corpus vertebrae inside a predefined ROI. Calibrations have been performed to obtain volumetric bone mineral density (vBMD) without having to add a calibration phantom or to use special scan protocols or hardware. Accuracy and precision are dependent on image noise and comparable to qCT images. Clinical indications are in accordance with the DEXA gold standard. The decomposition-based workflow shows bone degradation effects normally not visible on standard CT images which would induce errors in normal qCT results.

  2. Quantitative CT assessment of proximal femoral bone density. An experimental study concerning its correlation to breaking load for femoral neck fractures

    International Nuclear Information System (INIS)

    Buitrago-Tellez, C.H.; Schulze, C.; Gufler, H.; Langer, M.; Bonnaire, F.; Hoenninger, A.; Kuner, E.

    1997-01-01

    Purpose: In an experimental study, the correlation between the trabecular bone density of the different regions of the proximal femur and the fracture load in the setting of femoral neck fractures was examined. Methods: The bone mineral density 41 random proximal human femora was estimated by single-energy quanitative CT (SE-QCT). The trabecular bone density was measured at the greatest possible extracortical volume at midcapital, midneck and intertrochanteric level and in the 1 cm 3 volumes of the centres of these regions in a standardised 10 mm thick slice in the middle of the femoral neck axis (in mg/ml Ca-hydroxyl apatite). The proximal femora were then isolated and mounted on a compression/bending device under two-legged stand conditions and loaded up to the point when a femoral neck fracture occurred. Results: Statistical analysis revealed a linear correlation between the trabecular bone density and the fracture load for the greater regions, with the highest value in the maximal area of the head (coefficient factor r=0.76). Conclusion: According to our data, the measurement of the trabecular bone by SE-QCT at the femoral head is a more confident adjunct than the neck or trochanteric area to predict a femoral neck fracture. (orig.) [de

  3. Simultaneous bilateral isolated greater trochanter fracture

    Directory of Open Access Journals (Sweden)

    Maruti Kambali

    2013-01-01

    Full Text Available A 48-year-old woman sustained simultaneous isolated bilateral greater trochanteric fracture, following a road traffic accident. The patient presented to us 1 month after the injury. She presented with complaints of pain in the left hip and inability to walk. Roentgenograms revealed displaced comminuted bilateral greater trochanter fractures. The fracture of the left greater trochanter was reduced and fixed internally using the tension band wiring technique. The greater trochanter fracture on the right side was asymptomatic and was managed conservatively. The patient regained full range of motion and use of her hips after a postoperative follow-up of 6 months. Isolated fractures of the greater trochanter are unusual injuries. Because of their relative rarity and the unsettled controversy regarding their etiology and pathogenesis, several methods of treatment have been advocated. Furthermore, the reports of this particular type of injury are not plentiful and the average textbook coverage afforded to this entity is limited. In our study we discuss the mechanism of injury and the various treatment options available.

  4. A Robust Multifunctional Sandwich Panel Design with Trabecular Structures by the Use of Additive Manufacturing Technology for a New De-Icing System

    Directory of Open Access Journals (Sweden)

    Carlo Giovanni Ferro

    2017-06-01

    Full Text Available Anti-ice systems assure a vital on-board function in most aircraft: ice prevention or de-icing is mandatory for all aerodynamic surfaces to preserve their performance, and for all the movable surfaces to allow the proper control of the plane. In this work, a novel multi-functional panel concept which integrates anti-icing directly inside the primary structure is presented. In fact, constructing the core of the sandwich with trabecular non-stochastic cells allows the presence of a heat exchanger directly inside the structure with a savings in weight and an improvement in thermal efficiency. This solution can be realized easily in a single-piece component using Additive Manufacturing (AM technology without the need for joints, gluing, or welding. The objective of this study is to preliminarily investigate the mechanical properties of the core constructed with Selective Laser Melting (SLM; through the Design of Experiment (DOE, different design parameters were varied to understand how they affect the compression behaviour.

  5. Influence of meniscus on cartilage and subchondral bone features of knees from older individuals: A cadaver study.

    Science.gov (United States)

    Touraine, Sébastien; Bouhadoun, Hamid; Engelke, Klaus; Laredo, Jean Denis; Chappard, Christine

    2017-01-01

    Cartilage and subchondral bone form a functional unit. Here, we aimed to examine the effect of meniscus coverage on the characteristics of this unit in knees of older individuals. We assessed the hyaline cartilage, subchondral cortical plate (SCP), and subchondral trabecular bone in areas covered or uncovered by the meniscus from normal cadaver knees (without degeneration). Bone cores harvested from the medial tibial plateau at locations uncovered (central), partially covered (posterior), and completely covered (peripheral) by the meniscus were imaged by micro-CT. The following were measured on images: cartilage volume (Cart.Vol, mm3) and thickness (Cart.Th, mm); SCP thickness (SCP.Th, μm) and porosity (SCP.Por, %); bone volume to total volume fraction (BV/TV, %); trabecular thickness (Tb.Th, μm), spacing (Tb.Sp, μm), and number (Tb.N, 1/mm); structure model index (SMI); trabecular pattern factor (Tb.Pf); and degree of anisotropy (DA). Among the 28 specimens studied (18 females) from individuals with mean age 82.8±10.2 years, cartilage and SCP were thicker at the central site uncovered by the meniscus than the posterior and peripheral sites, and Cart.Vol was greater. SCP.Por was highest in posterior samples. In the upper 1-5 mm of subchondral bone, central samples were characterized by higher values for BV/TV, Tb.N, Tb.Th, and connectivity (Tb.Pf), a more plate-like trabecular structure and lower anisotropy than with other samples. Deeper down, at 6-10 mm, the differences were slightly higher for Tb.Th centrally, DA peripherally and SMI posteriorly. The coverage or not by meniscus in the knee of older individuals is significantly associated with Cart.Th, SCP.Th, SCP.Por and trabecular microarchitectural parameters in the most superficial 5 mm and to a lesser extent the deepest area of subchondral trabecular bone. These results suggest an effect of differences in local loading conditions. In subchondral bone uncovered by the meniscus, the trabecular architecture

  6. Influence of meniscus on cartilage and subchondral bone features of knees from older individuals: A cadaver study.

    Directory of Open Access Journals (Sweden)

    Sébastien Touraine

    Full Text Available Cartilage and subchondral bone form a functional unit. Here, we aimed to examine the effect of meniscus coverage on the characteristics of this unit in knees of older individuals.We assessed the hyaline cartilage, subchondral cortical plate (SCP, and subchondral trabecular bone in areas covered or uncovered by the meniscus from normal cadaver knees (without degeneration. Bone cores harvested from the medial tibial plateau at locations uncovered (central, partially covered (posterior, and completely covered (peripheral by the meniscus were imaged by micro-CT. The following were measured on images: cartilage volume (Cart.Vol, mm3 and thickness (Cart.Th, mm; SCP thickness (SCP.Th, μm and porosity (SCP.Por, %; bone volume to total volume fraction (BV/TV, %; trabecular thickness (Tb.Th, μm, spacing (Tb.Sp, μm, and number (Tb.N, 1/mm; structure model index (SMI; trabecular pattern factor (Tb.Pf; and degree of anisotropy (DA.Among the 28 specimens studied (18 females from individuals with mean age 82.8±10.2 years, cartilage and SCP were thicker at the central site uncovered by the meniscus than the posterior and peripheral sites, and Cart.Vol was greater. SCP.Por was highest in posterior samples. In the upper 1-5 mm of subchondral bone, central samples were characterized by higher values for BV/TV, Tb.N, Tb.Th, and connectivity (Tb.Pf, a more plate-like trabecular structure and lower anisotropy than with other samples. Deeper down, at 6-10 mm, the differences were slightly higher for Tb.Th centrally, DA peripherally and SMI posteriorly.The coverage or not by meniscus in the knee of older individuals is significantly associated with Cart.Th, SCP.Th, SCP.Por and trabecular microarchitectural parameters in the most superficial 5 mm and to a lesser extent the deepest area of subchondral trabecular bone. These results suggest an effect of differences in local loading conditions. In subchondral bone uncovered by the meniscus, the trabecular architecture

  7. Influence of estrogen deficiency and tibolone therapy on trabecular and cortical bone evaluated by computed radiography system in rats

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, Ana Carolina Bergmann de; Henriques, Helene Nara [Postgraduate Program in Pathology, Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil); Fernandes, Gustavo Vieira Oliveira [Postgraduate Program in Medical Sciences, Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil); Lima, Inaya; Oliveira, Davi Ferreira de; Lopes, Ricardo Tadeu [Nuclear Engineering Program, Federal University of Rio de Janeiro (UFRJ), RJ (Brazil); Pantaleao, Jose Augusto Soares [Maternal and Child Department, Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil); Granjeiro, Jose Mauro [Department of Cellular and Molecular Biology, Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil); Silva, Maria Angelica Guzman [Department of Pathology, Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil)

    2012-03-15

    Purpose: To verify the effects of tibolone administration on trabecular and cortical bone of ovariectomized female rats by computed radiography system (CRS). Methods: The experiment was performed on two groups of rats previously ovariectomized, one received tibolone (OVX+T) while the other did not (OVX), those groups were compared to a control group (C) not ovariectomized. Tibolone administration (1 mg/day) began thirty days after the ovariectomy and the treatment remained for five months. At last, the animals were euthanized and femurs and tibias collected. Computed radiographs of the bones were obtained and the digital images were used to determine the bone optical density and cortical thickness on every group. All results were statistically evaluated with significance set at P<0.05%. Results: Tibolone administration was shown to be beneficial only in the densitometric analysis of the femoral head, performing higher optical density compared to OVX. No difference was found in cortical bone thickness. Conclusion: Ovariectomy caused bone loss in the analyzed regions and tibolone administered in high doses over a long period showed not to be fully beneficial, but preserved bone mass in the femoral head. (author)

  8. Bone geometry, volumetric density, microarchitecture, and estimated bone strength assessed by HR-pQCT in Klinefelter syndrome

    DEFF Research Database (Denmark)

    Shanbhogue, Vikram V; Hansen, Stinus; Jørgensen, Niklas Rye

    2014-01-01

    Although the expected skeletal manifestations of testosterone deficiency in Klinefelter's syndrome (KS) are osteopenia and osteoporosis, the structural basis for this is unclear. The aim of this study was to assess bone geometry, volumetric bone mineral density (vBMD), microarchitecture...

  9. Risk Stratification of Stress Fractures and Prediction of Return to Duty

    Science.gov (United States)

    2015-12-01

    SUBJECT TERMS bone microarchitecture, HRpQCT, race, gender , sex, bone mineral density, vBMD, bone geometry, stress fracture 16. SECURITY...are collaborating with local sports medicine physicians, coaches, and athletic trainers to continue recruiting effectively (Task 3, objective 3). We

  10. Endothelial nitric oxide synthase deficiency influences normal cell cycle progression and apoptosis in trabecular meshwork cells

    Directory of Open Access Journals (Sweden)

    Qiong Liao

    2016-06-01

    Full Text Available AIM: To clarify how the endothelial nitric oxide synthase (eNOS, NOS3 make effect on outflow facility through the trabecular meshwork (TM. METHODS: Inhibition of NOS3 gene expression in human TM cells were conducted by three siRNAs. Then the mRNA and protein levels of NOS3 in siRNA-treated and negative control (NC cells were determined, still were the collagen, type IV, alpha 1 (COL4A1 and fibronectin 1 by real-time PCR and Western blot analysis. In addition, NOS3 concentrations in culture supernatant fluids of TM cells were measured. Cell cycle and cell apoptosis analysis were performed using flow cytometry. RESULTS: The mRNA level of NOS3 was decreased by three different siRNA interference, similar results were obtained not only of the relative levels of NOS3 protein, but also the expression levels of COL4A1 and fibronectin 1. The number of cells in S phase was decreased, while contrary result was obtained in G2 phase. The number of apoptotic cells in siRNA-treated groups were significant increased compared to the NC samples. CONCLUSION: Abnormal NOS3 expression can make effects on the proteins levels of extracellular matrix component (e.g. fibronectin 1 and COL4A1. Reduced NOS3 restrains the TM cell cycle progression at the G2/M-phase transition and induced cell apoptosis.

  11. Multiobjective topology optimization of trabecular Bone Structure in the spine and the femur: Implications for biomimcry

    Science.gov (United States)

    Elbanna, Ahmed; Peetz, Darin

    Bone is classically considered to be a self-optimizing structure in accordance with Wolff's law. However, while the structure's ability to adapt to changing stress patterns has been well documented, whether it is fully optimal for compliance is less certain (Sigmund, 2002). Given the complexity of many biological systems, it is expected that this structure serves several purposes. We present a multi-objective topology optimization formulation for trabecular bone in the human body at two locations: the vertebrae and the femur. We account for the effect of different conflicting objectives such as maximization of stiffness, maximization of surface area, and minimization of buckling susceptibility. Our formulation enables us to determine the relative role of each of these objective in optimizing the structure. Moreover, it provides an opportunity to explore what structural features have to evolve to meet a certain objective requirements that may have been absent otherwise. For example, inclusion of stability considerations introduce numerous horizontal and diagonal members in the topology in the case of human vertebrae under vertical loading. However, the stability is found to play a lesser role in the case of the femur bone optimization. Our formulation enables investigation of bone adaptation at different locations of the body as well as under different loading and boundary conditions (e.g. healthy and diseased discs for the case of the spine). We discuss the implications of our findings on developing design rules for bio-inspired and bio-mimetic architectured materials. National Science Foundation: CMMI.

  12. Cathepsin B is up-regulated and mediates extracellular matrix degradation in trabecular meshwork cells following phagocytic challenge.

    Directory of Open Access Journals (Sweden)

    Kristine Porter

    Full Text Available Cells in the trabecular meshwork (TM, a tissue responsible for draining aqueous humor out of the eye, are known to be highly phagocytic. Phagocytic activity in TM cells is thought to play an important role in outflow pathway physiology. However, the molecular mechanisms triggered by phagocytosis in TM cells are unknown. Here we investigated the effects of chronic phagocytic stress on lysosomal function using different phagocytic ligands (E. coli, carboxylated beads, collagen I-coated beads, and pigment. Lysotracker red co-localization and electron micrographs showed the maturation of E. coli- and collagen I-coated beads-containing phagosomes into phagolysosomes. Maturation of phagosomes into phagolysosomes was not observed with carboxylated beads or pigment particles. In addition, phagocytosis of E. coli and collagen I-coated beads led to increased lysosomal mass, and the specific up-regulation and activity of cathepsin B (CTSB. Higher levels of membrane-bound and secreted CTSB were also detected. Moreover, in vivo zymography showed the intralysosomal degradation of ECM components associated with active CTSB, as well as an overall increased gelatinolytic activity in phagocytically challenged TM cells. This increased gelatinolytic activity with phagocytosis was partially blocked with an intracellular CTSB inhibitor. Altogether, these results suggest a potential role of phagocytosis in outflow pathway tissue homeostasis through the up-regulation and/or proteolytic activation of extracellular matrix remodeling genes.

  13. Association of Trabecular Bone Score with Inflammation and Adiposity in Patients with Psoriasis: Effect of Adalimumab Therapy

    Directory of Open Access Journals (Sweden)

    José L. Hernández

    2016-01-01

    Full Text Available Studies on trabecular bone score (TBS in psoriasis are lacking. We aim to assess the association between TBS and inflammation, metabolic syndrome features, and serum adipokines in 29 nondiabetic patients with psoriasis without arthritis, before and after 6-month adalimumab therapy. For that purpose, adjusted partial correlations and stepwise multivariable linear regression analysis were performed. No correlation was found between TBS and disease severity. TBS was negatively associated with weight, BMI, waist perimeter, fat percentage, and systolic and diastolic blood pressure before and after adalimumab. After 6 months of therapy, a negative correlation between TBS and insulin resistance (p=0.02 and leptin (p=0.01 and a positive correlation with adiponectin were found (p=0.01. The best set of predictors for TBS values at baseline were female sex (p=0.015, age (p=0.05, and BMI (p=0.001. The best set of predictors for TBS following 6 months of biologic therapy were age (p=0.001, BMI (p<0.0001, and serum adiponectin levels (p=0.027. In conclusion, in nondiabetic patients with moderate-to-severe psoriasis, TBS correlates with metabolic syndrome features and inflammation. This association is still present after 6 months of adalimumab therapy. Moreover, serum adiponectin levels seem to be an independent variable related to TBS values, after adalimumab therapy.

  14. Outcome of revision total knee arthroplasty with the use of trabecular metal cone for reconstruction of severe bone loss at the proximal tibia

    DEFF Research Database (Denmark)

    Jensen, Claus L; Olsen, Nikolaj Winther; Schrøder, Henrik M

    2014-01-01

    technology (TMT) cones for the reconstruction of tibial bone loss at the time of rTKA. METHODS: Thirty-six patients had rTKA with the use of a TMT Cone. Bone loss was classified according to the AORI classification and 25% of the patients suffered from T3 AORI defects and 75% of the patients from T2 AORI...... defects. Implants used were from the NexGen series. At follow-up, radiographs were evaluated according to the Knee Society Roentgenographic Scoring System. Knee and function score was calculated using the Knee Society Clinical Rating System. Average follow-up time was 47 months (range 3-84 months......BACKGROUND: The relative effectiveness of different methods for reconstructing large bone loss at the proximal tibia in revision total knee arthroplasty (rTKA) has not been established. The aim of this study was to evaluate the clinical and radiological outcome after the use of trabecular metal...

  15. Increasing the number of unloading/reambulation cycles does not adversely impact body composition and lumbar bone mineral density but reduces tissue sensitivity

    Science.gov (United States)

    Gupta, Shikha; Manske, Sarah L.; Judex, Stefan

    2013-11-01

    A single exposure to hindlimb unloading leads to changes in body mass, body composition and bone, but the consequences of multiple exposures are not yet understood. Within a 18 week period, adult C57BL/6 male mice were exposed to 1 (1x-HLU), 2 (2x-HLU) or 3 (3x-HLU) cycles of 2 weeks of hindlimb unloading (HLU) followed by 4 weeks of reambulation (RA), or served as ambulatory age-matched controls. In vivo μCT longitudinally tracked changes in abdominal adipose and lean tissues, lumbar vertebral apparent volumetric bone mineral density (vBMD) and upper hindlimb muscle cross-sectional area before and after the final HLU and RA cycle. During the final HLU cycle, significant decreases in total adipose tissue and vertebral vBMD in the three experimental groups occurred such that there were no significant between-group differences at the beginning of the final RA cycle. However, the magnitude of the HLU induced losses diminished in mice undergoing their 2nd or 3rd HLU cycle. Irrespective of the number of HLU/RA cycles, total adipose tissue and vertebral vBMD recovered and were no different from age-matched controls after the final RA period. In contrast, upper hindlimb muscle cross-sectional area was significantly lower than controls in all unloaded groups after the final RA period. These results suggest that tissues in the abdominal region are more resilient to multiple bouts of unloading and more amenable to recovery during reambulation than the peripheral musculoskeletal system.

  16. Quantification of skeletal growth, modeling, and remodeling by in vivo micro computed tomography.

    Science.gov (United States)

    Altman, Allison R; Tseng, Wei-Ju; de Bakker, Chantal M J; Chandra, Abhishek; Lan, Shenghui; Huh, Beom Kang; Luo, Shiming; Leonard, Mary B; Qin, Ling; Liu, X Sherry

    2015-12-01

    In this study we established an image analysis scheme for the investigation of cortical and trabecular bone development during skeletal growth and tested this concept on in vivo μCT images of rats. To evaluate its efficacy, we applied the technique to young (1-month-old) and adult (3-month-old) rat tibiae with vehicle (Veh) or intermittent parathyroid hormone (PTH) treatment. By overlaying 2 sequential scans based on their distinct trabecular microarchitecture, we calculated the linear growth rate of young rats to be 0.31 mm/day at the proximal tibia. Due to rapid growth (3.7 mm in 12 days), the scanned bone region at day 12 had no overlap with the bone tissue scanned at day 0. Instead, the imaged bone region at day 12 represented newly generated bone tissue from the growth plate. The new bone of the PTH-treated rats had significantly greater trabecular bone volume fraction, number, and thickness than those of the Veh-treated rats, indicating PTH's anabolic effect on bone modeling. In contrast, the effect of PTH on adult rat trabecular bone was found to be caused by PTH's anabolic effect on bone remodeling. The cortical bone at the proximal tibia of young rats also thickened more in the PTH group (23%) than the Veh group (14%). This was primarily driven by endosteal bone formation and coalescence of trabecular bone into the cortex. This process can be visualized by aligning the local bone structural changes using image registration. As a result, the cortex after PTH treatment was 31% less porous, and had a 22% greater polar moment of inertia compared to the Veh group. Lastly, we monitored the longitudinal bone growth in adult rats by measuring the distance of bone flow away from the proximal tibial growth plate from 3 months to 19 months of age and discovered a total of 3.5mm growth in 16 months. It was demonstrated that this image analysis scheme can efficiently evaluate bone growth, bone modeling, and bone remodeling, and is ready to be translated into a

  17. Activation of human leukocytes on tantalum trabecular metal in comparison to commonly used orthopedic metal implant materials.

    Science.gov (United States)

    Schildhauer, T A; Peter, E; Muhr, G; Köller, M

    2009-02-01

    We analyzed leukocyte functions and cytokine response of human leukocytes toward porous tantalum foam biomaterial (Trabecular Metaltrade mark, TM) in comparison to equally sized solid orthopedic metal implant materials (pure titanium, titanium alloy, stainless steel, pure tantalum, and tantalum coated stainless steel). Isolated peripheral blood mononuclear cells (PBMC) and polymorphonuclear neutrophil leukocytes (PMN) were cocultured with equally sized metallic test discs for 24 h. Supernatants were analyzed for cytokine content by enzyme-linked immunosorbent assay. Compared to the other used test materials there was a significant increase in the release of IL (interleukin)-1ra and IL-8 from PMN, and of IL-1ra, IL-6, and TNF-alpha from PBMC in response to the TM material. The cytokine release correlated with surface roughness of the materials. In contrast, the release of IL-2 was not induced showing that mainly myeloid leukocytes were activated. In addition, supernatants of these leukocyte/material interaction (conditioned media, CM) were subjected to whole blood cell function assays (phagocytosis, chemotaxis, bacterial killing). There was a significant increase in the phagocytotic capacity of leukocytes in the presence of TM-conditioned media. The chemotactic response of leukocytes toward TM-conditioned media was significantly higher compared to CM obtained from other test materials. Furthermore, the bactericidal capacity of whole blood was enhanced in the presence of TM-conditioned media. These results indicate that leukocyte activation at the surface of TM material induces a microenvironment, which may enhance local host defense mechanisms.

  18. Greater autonomy at work

    NARCIS (Netherlands)

    Houtman, I.L.D.

    2004-01-01

    In the past 10 years, workers in the Netherlands increasingly report more decision-making power in their work. This is important for an economy in recession and where workers face greater work demands. It makes work more interesting, creates a healthier work environment, and provides opportunities

  19. Bone strength estimates relative to vertical ground reaction force discriminates women runners with stress fracture history.

    Science.gov (United States)

    Popp, Kristin L; McDermott, William; Hughes, Julie M; Baxter, Stephanie A; Stovitz, Steven D; Petit, Moira A

    2017-01-01

    To determine differences in bone geometry, estimates of bone strength, muscle size and bone strength relative to load, in women runners with and without a history of stress fracture. We recruited 32 competitive distance runners aged 18-35, with (SFX, n=16) or without (NSFX, n=16) a history of stress fracture for this case-control study. Peripheral quantitative computed tomography (pQCT) was used to assess volumetric bone mineral density (vBMD, mg/mm 3 ), total (ToA) and cortical (CtA) bone areas (mm 2 ), and estimated compressive bone strength (bone strength index; BSI, mg/mm 4 ) at the distal tibia. ToA, CtA, cortical vBMD, and estimated strength (section modulus; Zp, mm 3 and strength strain index; SSIp, mm 3 ) were measured at six cortical sites along the tibia. Mean active peak vertical (pkZ) ground reaction forces (GRFs), assessed from a fatigue run on an instrumented treadmill, were used in conjunction with pQCT measurements to estimate bone strength relative to load (mm 2 /N∗kg -1 ) at all cortical sites. SSIp and Zp were 9-11% lower in the SFX group at mid-shaft of the tibia, while ToA and vBMD did not differ between groups at any measurement site. The SFX group had 11-17% lower bone strength relative to mean pkZ GRFs (phistory of stress fracture. Bone strength relative to load is also lower in this same region suggesting that strength deficits in the middle 1/3 of the tibia and altered gait biomechanics may predispose an individual to stress fracture. Copyright © 2016. Published by Elsevier Inc.

  20. Relative contributions of lean and fat mass to bone strength in young Hispanic and non-Hispanic girls.

    Science.gov (United States)

    Hetherington-Rauth, Megan; Bea, Jennifer W; Blew, Robert M; Funk, Janet L; Hingle, Melanie D; Lee, Vinson R; Roe, Denise J; Wheeler, Mark D; Lohman, Timothy G; Going, Scott B

    2018-05-22

    With the high prevalence of childhood obesity, especially among Hispanic children, understanding how body weight and its components of lean and fat mass affect bone development is important, given that the amount of bone mineral accrued during childhood can determine osteoporosis risk later in life. The aim of this study was to assess the independent contributions of lean and fat mass on volumetric bone mineral density (vBMD), geometry, and strength in both weight-bearing and non-weight-bearing bones of Hispanic and non-Hispanic girls. Bone vBMD, geometry, and strength were assessed at the 20% distal femur, the 4% and 66% distal tibia, and the 66% distal radius of the non-dominant limb of 326, 9- to 12-year-old girls using peripheral quantitative computed tomography (pQCT). Total body lean and fat mass were measured by dual-energy x-ray absorptiometry (DXA). Multiple linear regression was used to assess the independent relationships of fat and lean mass with pQCT bone measures while adjusting for relevant confounders. Potential interactions between ethnicity and both fat and lean mass were also tested. Lean mass was a significant positive contributor to all bone outcomes (p Lean mass is the main determinant of bone strength for appendicular skeletal sites. Fat mass contributes to bone strength in the weight-bearing skeleton but does not add to bone strength in non-weight-bearing locations and may potentially be detrimental. Bone vBMD, geometry, and strength did not differ between Hispanic and non-Hispanic girls; fat mass may be a stronger contributor to bone strength in weight-bearing bones of Hispanic girls compared to non-Hispanic. Copyright © 2018. Published by Elsevier Inc.

  1. Beta-particle dosimetry of the trabecular skeleton using Monte Carlo transport within 3D digital images

    International Nuclear Information System (INIS)

    Jokisch, D.W.; Bouchet, L.G.; Patton, P.W.; Rajon, D.A.; Bolch, W.E.

    2001-01-01

    Presently, skeletal dosimetry models utilized in clinical medicine simulate electron path lengths through skeletal regions based upon distributions of linear chords measured across bone trabeculae and marrow cavities. In this work, a human thoracic vertebra has been imaged via nuclear magnetic resonance (NMR) spectroscopy yielding a three-dimensional voxelized representation of this skeletal site. The image was then coupled to the radiation transport code EGS4 allowing for 3D tracing of electron paths within its true 3D structure. The macroscopic boundaries of the trabecular regions, as well as the cortex of cortical bone surrounding the bone site, were explicitly considered in the voxelized transport model. For the case of a thoracic vertebra, energy escape to the cortical bone became significant at source energies exceeding ∼2 MeV. Chord-length distributions were acquired from the same NMR image, and subsequently used as input for a chord-based dosimetry model. Differences were observed in the absorbed fractions given by the chord-based model and the voxel transport model, suggesting that some of the input chord distributions for the chord-based models may not be accurate. Finally, this work shows that skeletal mass estimates can be made from the same NMR image in which particle transport is performed. This feature allows one to determine a skeletal S-value using absorbed fraction and mass data taken from the same anatomical tissue sample. The techniques developed in this work may be applied to a variety of skeletal sites, thus allowing for the development of skeletal dosimetry models at all skeletal sites for both males and females and as a function of subject age

  2. Orientation-weighted local Minkowski functionals in 3D for quantitative assessment of trabecular bone structure in the hip

    Science.gov (United States)

    Boehm, H. F.; Bitterling, H.; Weber, C.; Kuhn, V.; Eckstein, F.; Reiser, M.

    2007-03-01

    Fragility fractures or pathologic fractures of the hip, i.e. fractures with no apparent trauma, represent the worst complication in osteoporosis with a mortality close to 25% during the first post-traumatic year. Over 90% of hip fractures result from falls from standing height. A substantial number of femoral fractures are initiated in the femoral neck or the trochanteric regions which contain an internal architecture of trabeculae that are functionally highly specialized to withstand the complex pattern of external and internal forces associated with human gait. Prediction of the mechanical strength of bone tissue can be achieved by dedicated texture analysis of data obtained by high resolution imaging modalities, e.g. computed tomography (CT) or magnetic resonance tomography (MRI). Since in the case of the proximal femur, the connectivity, regional distribution and - most of all - the preferred orientation of individual trabeculae change considerably within narrow spatial limits, it seems most reasonable to evaluate the femoral bone structure on an orientation-weighted, local scale. In past studies, we could demonstrate the advantages of topological analysis of bone structure using the Minkowski Functionals in 3D on a global and on a local scale. The current study was designed to test the hypothesis that the prediction of the mechanical competence of the proximal femur by a new algorithm considering orientational changes of topological properties in the trabecular architecture is feasible and better suited than conventional methods based on the measurement of the mineral density of bone tissue (BMD).

  3. Live cell imaging of actin dynamics in dexamethasone-treated porcine trabecular meshwork cells.

    Science.gov (United States)

    Fujimoto, Tomokazu; Inoue, Toshihiro; Inoue-Mochita, Miyuki; Tanihara, Hidenobu

    2016-04-01

    The regulation of the actin cytoskeleton in trabecular meshwork (TM) cells is important for controlling outflow of the aqueous humor. In some reports, dexamethasone (DEX) increased the aqueous humor outflow resistance and induced unusual actin structures, such as cross-linked actin networks (CLAN), in TM cells. However, the functions and dynamics of CLAN in TM cells are not completely known, partly because actin stress fibers have been observed only in fixed cells. We conducted live-cell imaging of the actin dynamics in TM cells with or without DEX treatment. An actin-green fluorescent protein (GFP) fusion construct with a modified insect virus was transfected into porcine TM cells. Time-lapse imaging of live TM cells treated with 25 μM Y-27632 and 100 nM DEX was performed using an inverted fluorescence microscope. Fluorescent images were recorded every 15 s for 30 min after Y-27632 treatment or every 30 min for 72 h after DEX treatment. The GFP-actin was expressed in 22.7 ± 10.9% of the transfected TM cells. In live TM cells, many actin stress fibers were observed before the Y-27632 treatment. Y-27632 changed the cell shape and decreased stress fibers in a time-dependent manner. In fixed cells, CLAN-like structures were seen in 26.5 ± 1.7% of the actin-GFP expressed PTM cells treated with DEX for 72 h. In live imaging, there was 28% CLAN-like structure formation at 72 h after DEX treatment, and the lifetime of CLAN-like structures increased after DEX treatment. The DEX-treated cells with CLAN-like structures showed less migration than DEX-treated cells without CLAN-like structures. Furthermore, the control cells (without DEX treatment) with CLAN-like structures also showed less migration than the control cells without CLAN-like structures. These results suggested that CLAN-like structure formation was correlated with cell migration in TM cells. Live cell imaging of the actin cytoskeleton provides valuable information on the actin dynamics in TM

  4. Socio-economic considerations of cleaning Greater Vancouver's air

    International Nuclear Information System (INIS)

    2005-08-01

    Socio-economic considerations of better air quality on the Greater Vancouver population and economy were discussed. The purpose of the study was to provide socio-economic information to staff and stakeholders of the Greater Vancouver Regional District (GVRD) who are participating in an Air Quality Management Plan (AQMP) development process and the Sustainable Region Initiative (SRI) process. The study incorporated the following methodologies: identification and review of Canadian, American, and European quantitative socio-economic, cost-benefit, cost effectiveness, competitiveness and health analyses of changes in air quality and measures to improve air quality; interviews with industry representatives in Greater Vancouver on competitiveness impacts of air quality changes and ways to improve air quality; and a qualitative analysis and discussion of secondary quantitative information that identifies and evaluates socio-economic impacts arising from changes in Greater Vancouver air quality. The study concluded that for the Greater Vancouver area, the qualitative analysis of an improvement in Greater Vancouver air quality shows positive socio-economic outcomes, as high positive economic efficiency impacts are expected along with good social quality of life impacts. 149 refs., 30 tabs., 6 appendices

  5. Assessment of lumbar trabecular bone density by means of single energy quantitative CT in hospital control children and bone metabolic disorders, 1

    International Nuclear Information System (INIS)

    Nakano, Kazutoshi; Miyamoto, Akie; Imai, Kaoru; Mochizuki, Yumiko; Hayashi, Kitami; Mitsuishi, Yoichi; Fukuyama, Yukio; Kohno, Atsushi; Shigeta, Teiko

    1990-01-01

    We studied the 3rd lumbar vertebral trabecular bone mineral density in 59 cross-sectional pictures of quantitative computed tomography (QCT) with CaCO 3 phantom for 28 hospital control children and 30 cases of suspected bone metabolic disorders. The QCT value of bone mineral density of control children showed neither age dependency nor sexual difference before puberty: for males was 221.8±30.2 mg CaCO 3 /cm 3 (Mean±SD) under 4 years, 218.1±39.7 at 5∼9 years and 217.2±30.9 at 10∼15 years; and for females 220.9±18.3 under 4 years and 240.0±29.4 at 5∼9 years. The QCT values of bone mineral density in bed-ridden patients, children receiving glucocorticoids, and children receiving anticonvulsants were significantly lower than that in control children (p<0.005). The QCT value of bone mineral density of bed-ridden patients was significantly lower than that of children receiving glucocorticoids and of children receiving anticonvulsants (p<0.05, p<0.005 respectively). Our study confirmed that single energy quantitative CT was very useful in pediatric clinical application. (author)

  6. Greater trochanteric pain syndrome diagnosis and treatment.

    Science.gov (United States)

    Mallow, Michael; Nazarian, Levon N

    2014-05-01

    Lateral hip pain, or greater trochanteric pain syndrome, is a commonly seen condition; in this article, the relevant anatomy, epidemiology, and evaluation strategies of greater trochanteric pain syndrome are reviewed. Specific attention is focused on imaging of this syndrome and treatment techniques, including ultrasound-guided interventions. Copyright © 2014 Elsevier Inc. All rights reserved.

  7. Greater milk intake is associated with lower bone turnover, higher bone density, and higher bone microarchitecture index in a population of elderly Japanese men with relatively low dietary calcium intake: Fujiwara-kyo Osteoporosis Risk in Men (FORMEN) Study.

    Science.gov (United States)

    Sato, Y; Iki, M; Fujita, Y; Tamaki, J; Kouda, K; Yura, A; Moon, J-S; Winzenrieth, R; Iwaki, H; Ishizuka, R; Amano, N; Tomioka, K; Okamoto, N; Kurumatani, N

    2015-05-01

    The effects of milk intake on bone health are not clear in elderly Asian men with low dietary calcium intake. This study showed that greater milk intake is associated with lower bone turnover, higher bone density, and higher bone microarchitecture index in community-dwelling elderly Japanese men. The consumption of milk or dairy products is widely recommended for maintaining bone health regardless of gender or age. However, little evidence exists on the beneficial effects of milk intake on bone health in elderly Japanese men characterized with relatively low dietary calcium intake. Here we examined whether or not greater milk intake was associated with lower bone turnover, higher bone density, and stronger bone microarchitecture in community-dwelling elderly Japanese men. Interviews were conducted to obtain information on medical history and lifestyle, including the amount of habitual milk intake, nutrient intake calculations based on a 1-week food diary, and measurements of areal bone mineral density (aBMD) at the lumbar spine (LS), total hip (TH), and femoral neck (FN) by dual-energy x-ray absorptiometry (DXA), trabecular bone score (TBS) using DXA images at LS, and biochemical markers of bone turnover in sera. Participants with a history of diseases or medications that affect bone metabolism, or with missing data, were excluded from the analysis. The median intake of milk in the 1479 participants (mean age, 73.0 ± 5.1 years) was one glass of milk per day. Bone turnover markers showed a decreasing trend (p turnover, higher aBMD, and higher TBS in community-dwelling elderly Japanese men.

  8. Operational technology for greater confinement disposal

    International Nuclear Information System (INIS)

    Dickman, P.T.; Vollmer, A.T.; Hunter, P.H.

    1984-12-01

    Procedures and methods for the design and operation of a greater confinement disposal facility using large-diameter boreholes are discussed. It is assumed that the facility would be located at an operating low-level waste disposal site and that only a small portion of the wastes received at the site would require greater confinement disposal. The document is organized into sections addressing: facility planning process; facility construction; waste loading and handling; radiological safety planning; operations procedures; and engineering cost studies. While primarily written for low-level waste management site operators and managers, a detailed economic assessment section is included that should assist planners in performing cost analyses. Economic assessments for both commercial and US government greater confinement disposal facilities are included. The estimated disposal costs range from $27 to $104 per cubic foot for a commercial facility and from $17 to $60 per cubic foot for a government facility. These costs are based on average site preparation, construction, and waste loading costs for both contact- and remote-handled wastes. 14 figures, 22 tables

  9. Normal tempo of bone formation in Turner syndrome despite signs of accelerated bone resorption

    DEFF Research Database (Denmark)

    Cleemann, Line Hartvig; Holm, Kirsten Bagge; Kobbernagel, Hanne

    2011-01-01

    Aims: To evaluate area bone mineral density (aBMD) and volumetric BMD (vBMD) by dual-energy X-ray absorptiometry, and relations to bone markers and hormones in adolescent women with Turner syndrome (TS). Methods: Cross-sectional study in TS patients (n = 37, 16.7 ± 3.4 years) and control group (n...

  10. Normal Tempo of Bone Formation in Turner Syndrome despite Signs of Accelerated Bone Resorption

    DEFF Research Database (Denmark)

    Cleemann, Line; Holm, Kirsten; Kobbernagel, Hanne

    2011-01-01

    Aims: To evaluate area bone mineral density (aBMD) and volumetric BMD (vBMD) by dual-energy X-ray absorptiometry, and relations to bone markers and hormones in adolescent women with Turner syndrome (TS). Methods: Cross-sectional study in TS patients (n = 37, 16.7 ± 3.4 years) and control group (n...

  11. The Orientation of Nanoscale Apatite Platelets in Relation to Osteoblastic-Osteocyte Lacunae on Trabecular Bone Surface.

    Science.gov (United States)

    Shah, Furqan A; Zanghellini, Ezio; Matic, Aleksandar; Thomsen, Peter; Palmquist, Anders

    2016-02-01

    The orientation of nanoscale mineral platelets was quantitatively evaluated in relation to the shape of lacunae associated with partially embedded osteocytes (osteoblastic-osteocytes) on the surface of deproteinised trabecular bone of adult sheep. By scanning electron microscopy and image analysis, the mean orientation of mineral platelets at the osteoblastic-osteocyte lacuna (Ot.Lc) floor was found to be 19° ± 14° in the tibia and 20° ± 14° in the femur. Further, the mineral platelets showed a high degree of directional coherency: 37 ± 7% in the tibia and 38 ± 9% in the femur. The majority of Ot.Lc in the tibia (69.37%) and the femur (74.77%) exhibited a mean orientation of mineral platelets between 0° and 25°, with the largest fraction within a 15°-20° range, 17.12 and 19.8% in the tibia and femur, respectively. Energy dispersive X-ray spectroscopy and Raman spectroscopy were used to characterise the features observed on the anorganic bone surface. The Ca/P (atomic %) ratio was 1.69 ± 0.1 within the Ot.Lc and 1.68 ± 0.1 externally. Raman spectra of NaOCl-treated bone showed peaks associated with carbonated apatite: ν1, ν2 and ν4 PO4(3-), and ν1 CO3(2-), while the collagen amide bands were greatly reduced in intensity compared to untreated bone. The apatite-to-collagen ratio increased considerably after deproteinisation; however, the mineral crystallinity and the carbonate-to-phosphate ratios were unaffected. The ~19°-20° orientation of mineral platelets in at the Ot.Lc floor may be attributable to a gradual rotation of osteoblasts in successive layers relative to the underlying surface, giving rise to the twisted plywood-like pattern of lamellar bone.

  12. Characterization of cellular solids in Ti6Al4V for orthopaedic implant applications: Trabecular titanium.

    Science.gov (United States)

    Marin, E; Fusi, S; Pressacco, M; Paussa, L; Fedrizzi, L

    2010-07-01

    EBM (Electron Beam Melting) technology can be used successfully to obtain cellular solids in metallic biomaterials that can greatly increase osseointegration in arthroprothesis and at the same time maintain good mechanical properties. The investigated structures, called Trabecular Titanium, usually cannot be obtained by traditional machining. Two samples: (A) with a smaller single cell area and, (B) with a bigger single cell area, were produced and studied in this project. They have been completely characterized and compared with the results in similar literature pertinent to Ti6Al4V EBM structures. Relative density was evaluated using different methods, the mean diameter of the open porosities was calculated by Scanning Electron Microscope images; the composition was evaluated using Energy-Dispersive X-Ray Spectroscopy; the microstructure (alpha-beta) was investigated using chemical etching and, the mechanical proprieties were investigated using UMTS. The mean porosity values resulted comparable with spongy bone (63% for A and 72% for B). The mean diameter of the single porosity (650 mum for A and 1400 mum for B) resulted compatible with the osseointegration data from the literature, in particular for sample A. The Vickers micro-hardness tests and the chemical etching demonstrated that the structure is fine, uniform and well distributed. The mechanical test proved that sample (A) was more resistant than sample (B), but sample (B) showed an elastic modulus almost equal to the value of spongy bone. The results of this study suggest that the two Ti6Al4V cellular solids can be used in biomedical applications to promote osseointegration demonstrating that they maybe successfully used in prosthetic implants. Additional implant results will be published in the near future. Copyright 2010 Elsevier Ltd. All rights reserved.

  13. Greater trochanteric fracture with occult intertrochanteric extension.

    Science.gov (United States)

    Reiter, Michael; O'Brien, Seth D; Bui-Mansfield, Liem T; Alderete, Joseph

    2013-10-01

    Proximal femoral fractures are frequently encountered in the emergency department (ED). Prompt diagnosis is paramount as delay will exacerbate the already poor outcomes associated with these injuries. In cases where radiography is negative but clinical suspicion remains high, magnetic resonance imaging (MRI) is the study of choice as it has the capability to depict fractures which are occult on other imaging modalities. Awareness of a particular subset of proximal femoral fractures, namely greater trochanteric fractures, is vital for both radiologists and clinicians since it has been well documented that they invariably have an intertrochanteric component which may require surgical management. The detection of intertrochanteric or cervical extension of greater trochanteric fractures has been described utilizing MRI but is underestimated with both computed tomography (CT) and bone scan. Therefore, if MRI is unavailable or contraindicated, the diagnosis of an isolated greater trochanteric fracture should be met with caution. The importance of avoiding this potential pitfall is demonstrated in the following case of an elderly woman with hip pain and CT demonstrating an isolated greater trochanteric fracture who subsequently returned to the ED with a displaced intertrochanteric fracture.

  14. The Greater Sekhukhune-CAPABILITY outreach project.

    Science.gov (United States)

    Gregersen, Nerine; Lampret, Julie; Lane, Tony; Christianson, Arnold

    2013-07-01

    The Greater Sekhukhune-CAPABILITY Outreach Project was undertaken in a rural district in Limpopo, South Africa, as part of the European Union-funded CAPABILITY programme to investigate approaches for capacity building for the translation of genetic knowledge into care and prevention of congenital disorders. Based on previous experience of a clinical genetic outreach programme in Limpopo, it aimed to initiate a district clinical genetic service in Greater Sekhukhune to gain knowledge and experience to assist in the implementation and development of medical genetic services in South Africa. Implementing the service in Greater Sekhukhune was impeded by a developing staff shortage in the province and pressure on the health service from the existing HIV/AIDS and TB epidemics. This situation underscores the need for health needs assessment for developing services for the care and prevention of congenital disorders in middle- and low-income countries. However, these impediments stimulated the pioneering of innovate ways to offer medical genetic services in these circumstances, including tele-teaching of nurses and doctors, using cellular phones to enhance clinical care and adapting and assessing the clinical utility of a laboratory test, QF-PCR, for use in the local circumstances.

  15. Hyalinizing trabecular tumor of the thyroid: Diagnosed of a rare tumor using ultrasonography, cytology, and intraoperative frozen sections

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Hyun Sik; Kim, Eun Kyung; Kwak, Jin Young; Moon, Hee Jung; Yoon, Jung Hyun [Dept. of Radiology, Severance Hospital, Research Institute of Radiological Science, Yonsei University, College of Medicine, Seoul (Korea, Republic of); Park, Cheol Keun; Son, Eun Ju [Gangnam Severance Hospital, Yonsei University, College of Medicine, Seoul (Korea, Republic of)

    2016-03-15

    The goal of this study was to evaluate the clinicopathological and imaging features of thyroid nodules surgically diagnosed as hyaline trabecular tumor (HTT), and to assess the role of cytology and frozen sections (FS) in the diagnosis of HTT. This study included 21 thyroid nodules in 21 patients treated from August 2005 to March 2015 (mean age, 53.3 years) who were either diagnosed as HTT or had HTT suggested as a possible diagnosis based on cytology, FS, or the final pathology report. Patients' medical records were retrospectively reviewed for cytopathologic results and outcomes during the course of follow-up. Sonograms were reviewed and categorized. Twelve nodules from 12 patients were surgically confirmed as HTT. Ultrasonography (US)-guided fine needle aspiration (FNA) was performed on 11 nodules, of which six (54.5%) were papillary thyroid carcinoma (PTC) or suspicious for PTC and three (27.3%) were HTT or suspicious for HTT. Intraoperative FS suggested the possibility of HTT in seven nodules, of which four (57.1%) were confirmed as HTT. US-FNA suggested the diagnosis of HTT in 10 nodules, of which three (30.0%) were confirmed as HTT. Common US features of the 12 pathologically confirmed cases of HTT were hypoechogenicity or marked hypoechogenicity (83.4%), absence of calcifications (91.7%), parallel shape (100.0%), presence of vascularity (75.0%), and probable benignity (58.3%). HTT should be included in the differential diagnosis of solid tumors with hypoechogenicity or marked hypoechogenicity and otherwise benign US features that have been diagnosed as PTC through cytology.

  16. Hyalinizing trabecular tumor of the thyroid: Diagnosed of a rare tumor using ultrasonography, cytology, and intraoperative frozen sections

    International Nuclear Information System (INIS)

    Jang, Hyun Sik; Kim, Eun Kyung; Kwak, Jin Young; Moon, Hee Jung; Yoon, Jung Hyun; Park, Cheol Keun; Son, Eun Ju

    2016-01-01

    The goal of this study was to evaluate the clinicopathological and imaging features of thyroid nodules surgically diagnosed as hyaline trabecular tumor (HTT), and to assess the role of cytology and frozen sections (FS) in the diagnosis of HTT. This study included 21 thyroid nodules in 21 patients treated from August 2005 to March 2015 (mean age, 53.3 years) who were either diagnosed as HTT or had HTT suggested as a possible diagnosis based on cytology, FS, or the final pathology report. Patients' medical records were retrospectively reviewed for cytopathologic results and outcomes during the course of follow-up. Sonograms were reviewed and categorized. Twelve nodules from 12 patients were surgically confirmed as HTT. Ultrasonography (US)-guided fine needle aspiration (FNA) was performed on 11 nodules, of which six (54.5%) were papillary thyroid carcinoma (PTC) or suspicious for PTC and three (27.3%) were HTT or suspicious for HTT. Intraoperative FS suggested the possibility of HTT in seven nodules, of which four (57.1%) were confirmed as HTT. US-FNA suggested the diagnosis of HTT in 10 nodules, of which three (30.0%) were confirmed as HTT. Common US features of the 12 pathologically confirmed cases of HTT were hypoechogenicity or marked hypoechogenicity (83.4%), absence of calcifications (91.7%), parallel shape (100.0%), presence of vascularity (75.0%), and probable benignity (58.3%). HTT should be included in the differential diagnosis of solid tumors with hypoechogenicity or marked hypoechogenicity and otherwise benign US features that have been diagnosed as PTC through cytology

  17. The post-orgasmic prolactin increase following intercourse is greater than following masturbation and suggests greater satiety.

    Science.gov (United States)

    Brody, Stuart; Krüger, Tillmann H C

    2006-03-01

    Research indicates that prolactin increases following orgasm are involved in a feedback loop that serves to decrease arousal through inhibitory central dopaminergic and probably peripheral processes. The magnitude of post-orgasmic prolactin increase is thus a neurohormonal index of sexual satiety. Using data from three studies of men and women engaging in masturbation or penile-vaginal intercourse to orgasm in the laboratory, we report that for both sexes (adjusted for prolactin changes in a non-sexual control condition), the magnitude of prolactin increase following intercourse is 400% greater than that following masturbation. The results are interpreted as an indication of intercourse being more physiologically satisfying than masturbation, and discussed in light of prior research reporting greater physiological and psychological benefits associated with coitus than with any other sexual activities.

  18. Assessment of lumbar trabecular bone density by means of single energy quantitative CT in hospital control children and bone metabolic disorders, 1

    Energy Technology Data Exchange (ETDEWEB)

    Nakano, Kazutoshi; Miyamoto, Akie; Imai, Kaoru; Mochizuki, Yumiko; Hayashi, Kitami; Mitsuishi, Yoichi; Fukuyama, Yukio; Kohno, Atsushi; Shigeta, Teiko (Tokyo Women' s Medical Coll. (Japan))

    1990-03-01

    We studied the 3rd lumbar vertebral trabecular bone mineral density in 59 cross-sectional pictures of quantitative computed tomography (QCT) with CaCO{sub 3} phantom for 28 hospital control children and 30 cases of suspected bone metabolic disorders. The QCT value of bone mineral density of control children showed neither age dependency nor sexual difference before puberty: for males was 221.8{plus minus}30.2 mg CaCO{sub 3}/cm{sup 3} (Mean{plus minus}SD) under 4 years, 218.1{plus minus}39.7 at 5{approx}9 years and 217.2{plus minus}30.9 at 10{approx}15 years; and for females 220.9{plus minus}18.3 under 4 years and 240.0{plus minus}29.4 at 5{approx}9 years. The QCT values of bone mineral density in bed-ridden patients, children receiving glucocorticoids, and children receiving anticonvulsants were significantly lower than that in control children (p<0.005). The QCT value of bone mineral density of bed-ridden patients was significantly lower than that of children receiving glucocorticoids and of children receiving anticonvulsants (p<0.05, p<0.005 respectively). Our study confirmed that single energy quantitative CT was very useful in pediatric clinical application. (author).

  19. Technical concept for a greater-confinement-disposal test facility

    International Nuclear Information System (INIS)

    Hunter, P.H.

    1982-01-01

    Greater confinement disposal (GCO) has been defined by the National Low-Level Waste Program as the disposal of low-level waste in such a manner as to provide greater containment of radiation, reduce potential for migration or dispersion or radionuclides, and provide greater protection from inadvertent human and biological intrusions in order to protect the public health and safety. This paper discusses: the need for GCD; definition of GCD; advantages and disadvantages of GCD; relative dose impacts of GCD versus shallow land disposal; types of waste compatible with GCD; objectives of GCD borehole demonstration test; engineering and technical issues; and factors affecting performance of the greater confinement disposal facility

  20. In vitro and in vivo evaluation of a macro porous β-TCP granule-shaped bone substitute fabricated by the fibrous monolithic process

    International Nuclear Information System (INIS)

    Kim, Young-Hee; Jyoti, M Anirban; Song, Ho-Yeon; Youn, Min-Ho; Lee, Byong-Taek; Youn, Hyung-Sun; Seo, Hyung-Seok

    2010-01-01

    In this study, a new porous beta-tricalcium phosphate (β-TCP) granule was fabricated using the fibrous monolithic (FM) process and its in vitro biocompatibility and in vivo bone formation were evaluated. SEM micrograph images showed that MG-63 cells attached to the surfaces of the implant and were well proliferated. Cellular viability was as high as 75% in a 50% extract dilution solution. cDNA micro array analysis was also carried out. In this analysis, we found a total of 12 up-regulated and 25 down-regulated genes. Four rabbits were used in the in vivo experiments. 3D micro-CT images showed that the formation of new bone was almost three times greater than that of normal trabecular bone (BV/TV). The histomorphometric results correlated with the micro-CT findings; a greater amount of new bone formation and osteoblast lineage along with osteocytes were observed in the implanted animals. Also x-ray radiographic and 2D micro-CT images were taken to demonstrate the superior biodegradability of the porous granule. As biodegradation occurred along with bone formation, 6 months after implantation, the porous granule structure was not distinguishable separately from that of the trabecular bone.

  1. Effects of Obesity on Bone Mass and Quality in Ovariectomized Female Zucker Rats

    Directory of Open Access Journals (Sweden)

    Rafaela G. Feresin

    2014-01-01

    Full Text Available Obesity and osteoporosis are two chronic conditions that have been increasing in prevalence. Despite prior data supporting the positive relationship between body weight and bone mineral density (BMD, recent findings show excess body weight to be detrimental to bone mass, strength, and quality. To evaluate whether obesity would further exacerbate the effects of ovariectomy on bone, we examined the tibiae and fourth lumbar (L4 vertebrae from leptin receptor-deficient female (Leprfa/fa Zucker rats and their heterozygous lean controls (Leprfa/+ that were either sham-operated or ovariectomized (Ovx. BMD of L4 vertebra was measured using dual-energy X-ray absorptiometry, and microcomputed tomography was used to assess the microstructural properties of the tibiae. Ovariectomy significantly (P<0.001 decreased the BMD of L4 vertebrae in lean and obese Zucker rats. Lower trabecular number and greater trabecular separation (P<0.001 were also observed in the tibiae of lean- and obese-Ovx rats when compared to sham rats. However, only the obese-Ovx rats had lower trabecular thickness (Tb.Th (P<0.005 than the other groups. These findings demonstrated that ovarian hormone deficiency adversely affected bone mass and quality in lean and obese rats while obesity only affected Tb.Th in Ovx-female Zucker rats.

  2. Reproducibility of trabecular bone score with different scan modes using dual-energy X-ray absorptiometry: a phantom study

    Energy Technology Data Exchange (ETDEWEB)

    Bandirali, Michele; Messina, Carmelo [Universita degli Studi di Milano, Scuola di Specializzazione in Radiodiagnostica, Milano (Italy); Di Leo, Giovanni [Unita di Radiologia, IRCCS Policlinico San Donato, San Donato Milanese (Italy); Pastor Lopez, Maria Juana; Ulivieri, Fabio M. [Servizio di Medicina Nucleare, Ospedale Maggiore, Mineralometria Ossea Computerizzata e Ambulatorio Malattie Metabolismo Minerale e Osseo, Milano (Italy); Mai, Alessandro [Universita degli Studi di Milano, Tecniche di Radiologia Medica, per Immagini e Radioterapia, Milano (Italy); Sardanelli, Francesco [Unita di Radiologia, IRCCS Policlinico San Donato, San Donato Milanese (Italy); Universita degli Studi di Milano, Dipartimento di Scienze Biomediche per la Salute, San Donato Milanese (Italy)

    2014-08-12

    The trabecular bone score (TBS) accounts for the bone microarchitecture and is calculated on dual-energy X-ray absorptiometry (DXA). We estimated the reproducibility of the TBS using different scan modes compared to the reproducibility bone mineral density (BMD). A spine phantom was used with a Hologic QDR-Discovery A densitometer. For each scan mode [fast array, array, high definition (HD)], 25 scans were automatically performed without phantom repositioning; a further 25 scans were performed with phantom repositioning. For each scan, the TBS was obtained. The coefficient of variation (CoV) was calculated as the ratio between standard deviation and mean; percent least significant change (LSC%) as 2.8 x CoV; reproducibility as the complement to 100 % of LSC%. Differences among scan modes were assessed using ANOVA. Without phantom repositioning, the mean TBS (mm{sup -1}) was: 1.352 (fast array), 1.321 (array), and 1.360 (HD); with phantom repositioning, it was 1.345, 1.332, and 1.362, respectively. Reproducibility of the TBS without phantom repositioning was 97.7 % (fast array), 98.3 % (array), and 98.2 % (HD); with phantom repositioning, it was 97.9 %, 98.7 %, and 98.4 %, respectively. LSC% was ≤2.26 %. Differences among scan modes were all statistically significant (p ≤ 0.019). Reproducibility of BMD was 99.1 % with all scan modes, while LSC% was from 0.86 % to 0.91 %. Reproducibility error of the TBS was 2-3-fold higher than that of BMD. Although statistically significant, differences in TBS among scan modes were within the highest LSC%. Thus, the three scan modes can be considered interchangeable. (orig.)

  3. Role of disc area and trabecular bone density on lumbar spinal column fracture risk curves under vertical impact.

    Science.gov (United States)

    Yoganandan, Narayan; Moore, Jason; Pintar, Frank A; Banerjee, Anjishnu; DeVogel, Nicholas; Zhang, JiangYue

    2018-04-27

    While studies have been conducted using human cadaver lumbar spines to understand injury biomechanics in terms of stability/energy to fracture, and physiological responses under pure-moment/follower loads, data are sparse for inferior-to-superior impacts. Injuries occur under this mode from underbody blasts. determine role of age, disc area, and trabecular bone density on tolerances/risk curves under vertical loading from a controlled group of specimens. T12-S1 columns were obtained, pretest X-rays and CTs taken, load cells attached to both ends, impacts applied at S1-end using custom vertical accelerator device, and posttest X-ray, CT, and dissections done. BMD of L2-L4 vertebrae were obtained from QCT. Survival analysis-based Human Injury Probability Curves (HIPCs) were derived using proximal and distal forces. Age, area, and BMD were covariates. Forces were considered uncensored, representing the load carrying capacity. The Akaike Information Criterion was used to determine optimal distributions. The mean forces, ±95% confidence intervals, and Normalized Confidence Interval Size (NCIS) were computed. The Lognormal distribution was the optimal function for both forces. Age, area, and BMD were not significant (p > 0.05) covariates for distal forces, while only BMD was significant for proximal forces. The NCIS was the lowest for force-BMD covariate HIPC. The HIPCs for both genders at 35 and 45 years were based on population BMDs. These HIPCs serve as human tolerance criteria for automotive, military, and other applications. In this controlled group of samples, BMD is a better predictor-covariate that characterizes lumbar column injury under inferior-to-superior impacts. Published by Elsevier Ltd.

  4. Involvement of Tiam1, RhoG and ELMO2/ILK in Rac1-mediated phagocytosis in human trabecular meshwork cells.

    Science.gov (United States)

    Peotter, Jennifer L; Phillips, Jenny; Tong, Tiegang; Dimeo, Kaylee; Gonzalez, Jose M; Peters, Donna M

    2016-10-01

    We previously demonstrated that an αvβ5 integrin/FAK- mediated pathway regulated the phagocytic properties of human trabecular meshwork (HTM) cells. Here we demonstrate that this process is mediated by Rac-1 and a previously unreported signaling pathway that utilizes the Tiam1 as well as a novel ILK/RhoG/ELMO2 signaling pathway. Phagocytosis in both a TM-1 cell line and normal HTM cells was mediated by Rac1 and could be significantly decreased by >75% using the Rac1 inhibitor EHop-016. Knockdown of Rac1 in TM-1 cells also inhibited phagocytosis by 40% whereas overexpression of a constitutively active Rac1 or stimulation with PDGF increased phagocytosis by 83% and 32% respectively. Tiam1 was involved in regulating phagocytosis. Knockdown of Tiam1 inhibited phagocytosis by 72% while overexpression of Tiam1 C1199 increased phagocytosis by 75%. Other upstream effectors of Rac1 found to be involved included ELMO2, RhoG, and ILK. Knockdowns of ELMO2, ILK, and RhoG caused a reduction in phagocytosis by 51%, 55% and 46% respectively. In contrast, knockdown of Vav2 and Dock1 or overexpression of Vav2 Y159/172F did not cause a significant change in phagocytosis. These data suggest a novel link between Tiam1 and RhoG/ILK /ELMO2 pathway as upstream effectors of the Rac1-mediated phagocytic process in TM cells. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Effect of growth hormone therapy and puberty on bone and body composition in children with idiopathic short stature and growth hormone deficiency.

    Science.gov (United States)

    Högler, Wolfgang; Briody, Julie; Moore, Bin; Lu, Pei Wen; Cowell, Christopher T

    2005-11-01

    The state of bone health and the effect of growth hormone (GH) therapy on bone and body composition in children with idiopathic short stature (ISS) are largely unknown. A direct role of GH deficiency (GHD) on bone density is controversial. Using dual-energy X-ray absorptiometry, this study measured total body bone mineral content (TB BMC), body composition, and volumetric bone mineral density (vBMD) at the lumbar spine (LS) and femoral neck (FN) in 77 children (aged 3-17 years) with ISS (n = 57) and GHD (n = 20). Fifty-five children (GHD = 13) receiving GH were followed over 24 months including measurement of bone turnover. At diagnosis, size-corrected TB BMC SDS was greater (P bone relation, as assessed by the BMC/lean mass (LTM) ratio SDS was not different between groups. During GH therapy, prepubertal GHD children gained more height (1.58 [0.9] SDS) and LTM (0.87 [0.63] SDS) compared to prepubertal ISS children (0.75 [0.27] and 0.17 [0.25] SDS, respectively). Percent body fat decreased in GHD (-5.94% [4.29]) but not in ISS children. Total body BMC accrual was less than predicted in all groups accompanied by an increase in bone turnover. Puberty led to the greatest absolute, but not relative, increments in weight, LTM, BMI, bone mass, and LSvBMD. Our results show that children with ISS and GHD differ in their response to GH therapy in anthropometry, body composition, and bone measures. Despite low vBMD values at diagnosis in both prepubertal groups, size-corrected regional or TB bone data were generally within the normal range and did not increase during GH therapy in GHD or ISS children. Growth hormone had great effects on the growth plate and body composition with subsequent gains in height, LTM, bone turnover, and bone mass accrual, but no benefit for volumetric bone density over 2 years.

  6. Fractures of the greater trochanter following total hip replacement.

    Science.gov (United States)

    Brun, Ole-Christian L; Maansson, Lukas

    2013-01-01

    We studied the incidence of greater trochanteric fractures at our department following THR. In all we examined 911 patients retrospectively and found the occurance of a greater trochanteric fracture to be 3%. Patients with fractures had significantly poorer outcome on Oxford Hip score, Pain VAS, Satisfaction VAS and EQ-5D compared to THR without fractures. Greater trochanteric fracture following THR is one of the most common complications following THR. It has previously been thought to have little impact on the overall outcome following THR, but our study suggests otherwise.

  7. Greater temperature sensitivity of plant phenology at colder sites

    DEFF Research Database (Denmark)

    Prevey, Janet; Vellend, Mark; Ruger, Nadja

    2017-01-01

    Warmer temperatures are accelerating the phenology of organisms around the world. Temperature sensitivity of phenology might be greater in colder, higher latitude sites than in warmer regions, in part because small changes in temperature constitute greater relative changes in thermal balance...

  8. Greater Somalia, the never-ending dream?

    DEFF Research Database (Denmark)

    Zoppi, Marco

    2015-01-01

    This paper provides an historical analysis of the concept of Greater Somalia, the nationalist project that advocates the political union of all Somali-speaking people, including those inhabiting areas in current Djibouti, Ethiopia and Kenya. The Somali territorial unification project of “lost...

  9. β-1,3-Glucan, Which Can Be Targeted by Drugs, Forms a Trabecular Scaffold in the Oocyst Walls of Toxoplasma and Eimeria

    Science.gov (United States)

    Bushkin, G. Guy; Motari, Edwin; Magnelli, Paula; Gubbels, Marc-Jan; Dubey, Jitender P.; Miska, Katarzyna B.; Bullitt, Esther; Costello, Catherine E.; Robbins, Phillips W.; Samuelson, John

    2012-01-01

    ABSTRACT The walls of infectious pathogens, which are essential for transmission, pathogenesis, and diagnosis, contain sugar polymers that are defining structural features, e.g., β-1,3-glucan and chitin in fungi, chitin in Entamoeba cysts, β-1,3-GalNAc in Giardia cysts, and peptidoglycans in bacteria. The goal here was to determine in which of three walled forms of Toxoplasma gondii (oocyst, sporocyst, or tissue cyst) is β-1,3-glucan, the product of glucan synthases and glucan hydrolases predicted by whole-genome sequences of the parasite. The three most important discoveries were as follows. (i) β-1,3-glucan is present in oocyst walls of Toxoplasma and Eimeria (a chicken parasite that is a model for intestinal stages of Toxoplasma) but is absent from sporocyst and tissue cyst walls. (ii) Fibrils of β-1,3-glucan are part of a trabecular scaffold in the inner layer of the oocyst wall, which also includes a glucan hydrolase that has a novel glucan-binding domain. (iii) Echinocandins, which target the glucan synthase and kill fungi, arrest development of the Eimeria oocyst wall and prevent release of the parasites into the intestinal lumen. In summary, β-1,3-glucan, which can be targeted by drugs, is an important component of oocyst walls of Toxoplasma but is not a component of sporocyst and tissue cyst walls. PMID:23015739

  10. Assessing Human Impacts on the Greater Akaki River, Ethiopia ...

    African Journals Online (AJOL)

    We assessed the impacts of human activities on the Greater Akaki River using physicochemical parameters and macroinvertebrate metrics. Physicochemical samples and macroinvertebrates were collected bimonthly from eight sites established on the Greater Akaki River from February 2006 to April 2006. Eleven metrics ...

  11. Molecular insights into the biology of Greater Sage-Grouse

    Science.gov (United States)

    Oyler-McCance, Sara J.; Quinn, Thomas W.

    2011-01-01

    Recent research on Greater Sage-Grouse (Centrocercus urophasianus) genetics has revealed some important findings. First, multiple paternity in broods is more prevalent than previously thought, and leks do not comprise kin groups. Second, the Greater Sage-Grouse is genetically distinct from the congeneric Gunnison sage-grouse (C. minimus). Third, the Lyon-Mono population in the Mono Basin, spanning the border between Nevada and California, has unique genetic characteristics. Fourth, the previous delineation of western (C. u. phaios) and eastern Greater Sage-Grouse (C. u. urophasianus) is not supported genetically. Fifth, two isolated populations in Washington show indications that genetic diversity has been lost due to population declines and isolation. This chapter examines the use of molecular genetics to understand the biology of Greater Sage-Grouse for the conservation and management of this species and put it into the context of avian ecology based on selected molecular studies.

  12. INDUSTRIAL LAND DEVELOPMENT AND MANUFACTURING DECONCENTRATION IN GREATER JAKARTA

    NARCIS (Netherlands)

    Hudalah, Delik; Viantari, Dimitra; Firman, Tommy; Woltjer, Johan

    2013-01-01

    Industrial land development has become a key feature of urbanization in Greater Jakarta, one of the largest metropolitan areas in Southeast Asia. Following Suharto's market-oriented policy measures in the late 1980s, private developers have dominated the land development projects in Greater Jakarta.

  13. Tissue characteristics of high- and low-incidence plutonium-induced osteogenic sarcoma sites in life-span beagles

    International Nuclear Information System (INIS)

    Miller, S.C.; Jee, W.S.S.; Smith, J.M.; Wronski, T.J.

    1986-01-01

    On the basis of information gathered from the 239 Pu life-span study in beagles at the University of Utah, the tissue features were found to be characteristic of high-incidence bone-tumor sites compared to low-incidence sites included more hematopoietic tissues in the bone marrow; greater trabecular bone mass; greater bone remodeling rates; greater mineral apposition rates; greater density and activity of bone surface cells; greater density of putative bone-cell precursors; greater initial uptake of plutonium on bone surfaces; and greater marrow vascular volumes and a venous sinusoidal bed. Although most of these studies are not yet complete, the information being collected should contribute to our understanding of the mechanisms of radiation-induced osteogenic sarcomas. This should aid in predicting the types and characteristics of osseous tissues where radiation-induced osteogenic sarcomas may arise in humans. 25 refs., 4 figs., 3 tabs

  14. Using a method based on Potts Model to segment a micro-CT image stack of trabecular bones of femoral region

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, Pedro H.A. de; Cabral, Manuela O.M., E-mail: andrade.pha@gmail.com [Universidade Federal de Pernambuco (DEN/UFPE), Recife, PE (Brazil). Departamento de Engenharia Nuclear; Vieira, Jose W.; Correia, Filipe L. de B., E-mail: jose.wilson59@uol.com.br [Instituto Federal de Educacao, Ciencia e Tecnologia de Pernambuco (IFPE), Recife, PE (Brazil); Lima, Fernando R. De A., E-mail: falima@cnen.gov.br [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (brazil)

    2015-07-01

    Exposure Computational Models are composed basically of an anthropomorphic phantom, a Monte Carlo (MC) code, and an algorithm simulator of the radioactive source. Tomographic phantoms are developed from medical images and must be pre-processed and segmented before being coupled to a MC code (which simulates the interaction of radiation with matter). This work presents a methodology used for treatment of micro-CT images stack of a femur, obtained from a 30 year old female skeleton provided by the Imaging Laboratory for Anthropology of the University of Bristol, UK. These images contain resolution of 60 micrometers and from these a block containing only 160 x 60 x 160 pixels of trabecular tissues and bone marrow was cut and saved as ⁎.sgi file (header + ⁎.raw file). The Grupo de Dosimetria Numerica (Recife-PE, Brazil) developed a software named Digital Image Processing (DIP), in which a method for segmentation based on a physical model for particle interaction known as Potts Model (or q-Ising) was implemented. This model analyzes the statistical dependence between sites in a network. In Potts Model, when the values of spin variables at neighboring sites are identical, it is assigned an 'energy of interaction' between them. Otherwise, it is said that the sites do not interact. Making an analogy between network sites and the pixels of a digital image and, moreover, between the spins variables and the intensity of the gray scale, it was possible to apply this model to obtain texture descriptors and segment the image. (author)

  15. Using a method based on Potts Model to segment a micro-CT image stack of trabecular bones of femoral region

    International Nuclear Information System (INIS)

    Andrade, Pedro H.A. de; Cabral, Manuela O.M.; Lima, Fernando R. De A.

    2015-01-01

    Exposure Computational Models are composed basically of an anthropomorphic phantom, a Monte Carlo (MC) code, and an algorithm simulator of the radioactive source. Tomographic phantoms are developed from medical images and must be pre-processed and segmented before being coupled to a MC code (which simulates the interaction of radiation with matter). This work presents a methodology used for treatment of micro-CT images stack of a femur, obtained from a 30 year old female skeleton provided by the Imaging Laboratory for Anthropology of the University of Bristol, UK. These images contain resolution of 60 micrometers and from these a block containing only 160 x 60 x 160 pixels of trabecular tissues and bone marrow was cut and saved as ⁎.sgi file (header + ⁎.raw file). The Grupo de Dosimetria Numerica (Recife-PE, Brazil) developed a software named Digital Image Processing (DIP), in which a method for segmentation based on a physical model for particle interaction known as Potts Model (or q-Ising) was implemented. This model analyzes the statistical dependence between sites in a network. In Potts Model, when the values of spin variables at neighboring sites are identical, it is assigned an 'energy of interaction' between them. Otherwise, it is said that the sites do not interact. Making an analogy between network sites and the pixels of a digital image and, moreover, between the spins variables and the intensity of the gray scale, it was possible to apply this model to obtain texture descriptors and segment the image. (author)

  16. Strategies for Talent Management: Greater Philadelphia Companies in Action

    Science.gov (United States)

    Council for Adult and Experiential Learning (NJ1), 2008

    2008-01-01

    Human capital is one of the critical issues that impacts the Greater Philadelphia region's ability to grow and prosper. The CEO Council for Growth (CEO Council) is committed to ensuring a steady and talented supply of quality workers for this region. "Strategies for Talent Management: Greater Philadelphia Companies in Action" provides…

  17. Greater oil investment opportunities

    International Nuclear Information System (INIS)

    Arenas, Ismael Enrique

    1997-01-01

    Geologically speaking, Colombia is a very attractive country for the world oil community. According to this philosophy new and important steps are being taken to reinforce the oil sector: Expansion of the exploratory frontier by including a larger number of sedimentary areas, and the adoption of innovative contracting instruments. Colombia has to offer, Greater economic incentives for the exploration of new areas to expand the exploratory frontier, stimulation of exploration in areas with prospectivity for small fields. Companies may offer Ecopetrol a participation in production over and above royalties, without it's participating in the investments and costs of these fields, more favorable conditions for natural gas seeking projects, in comparison with those governing the terms for oil

  18. Improving greater trochanteric reattachment with a novel cable plate system.

    Science.gov (United States)

    Baril, Yannick; Bourgeois, Yan; Brailovski, Vladimir; Duke, Kajsa; Laflamme, G Yves; Petit, Yvan

    2013-03-01

    Cable-grip systems are commonly used for greater trochanteric reattachment because they have provided the best fixation performance to date, even though they have a rather high complication rate. A novel reattachment system is proposed with the aim of improving fixation stability. It consists of a Y-shaped fixation plate combined with locking screws and superelastic cables to reduce cable loosening and limit greater trochanter movement. The novel system is compared with a commercially available reattachment system in terms of greater trochanter movement and cable tensions under different greater trochanteric abductor application angles. A factorial design of experiments was used including four independent variables: plate system, cable type, abductor application angle, and femur model. The test procedure included 50 cycles of simultaneous application of an abductor force on the greater trochanter and a hip force on the femoral head. The novel plate reduces the movements of a greater trochanter fragment within a single loading cycle up to 26%. Permanent degradation of the fixation (accumulated movement based on 50-cycle testing) is reduced up to 46%. The use of superelastic cables reduces tension loosening up to 24%. However this last improvement did not result in a significant reduction of the grater trochanter movement. The novel plate and cables present advantages over the commercially available greater trochanter reattachment system. The plate reduces movements generated by the hip abductor. The superelastic cables reduce cable loosening during cycling. Both of these positive effects could decrease the risks related to grater trochanter non-union. Copyright © 2012 IPEM. Published by Elsevier Ltd. All rights reserved.

  19. Sequences of Regressions Distinguish Nonmechanical from Mechanical Associations between Metabolic Factors, Body Composition, and Bone in Healthy Postmenopausal Women.

    Science.gov (United States)

    Solis-Trapala, Ivonne; Schoenmakers, Inez; Goldberg, Gail R; Prentice, Ann; Ward, Kate A

    2016-03-09

    There is increasing recognition of complex interrelations between the endocrine functions of bone and fat tissues or organs. The objective was to describe nonmechanical and mechanical links between metabolic factors, body composition, and bone with the use of graphical Markov models. Seventy postmenopausal women with a mean ± SD age of 62.3 ± 3.7 y and body mass index (in kg/m 2 ) of 24.9 ± 3.8 were recruited. Bone outcomes were peripheral quantitative computed tomography measures of the distal and diaphyseal tibia, cross-sectional area (CSA), volumetric bone mineral density (vBMD), and cortical CSA. Biomarkers of osteoblast and adipocyte function were plasma concentrations of leptin, adiponectin, osteocalcin, undercarboxylated osteocalcin (UCOC), and phylloquinone. Body composition measurements were lean and percent fat mass, which were derived with the use of a 4-compartment model. Sequences of Regressions, a subclass of graphical Markov models, were used to describe the direct (nonmechanical) and indirect (mechanical) interrelations between metabolic factors and bone by simultaneously modeling multiple bone outcomes and their relation with biomarker outcomes with lean mass, percent fat mass, and height as intermediate explanatory variables. The graphical Markov models showed both direct and indirect associations linking plasma leptin and adiponectin concentrations with CSA and vBMD. At the distal tibia, lean mass, height, and adiponectin-UCOC interaction were directly explanatory of CSA (R 2 = 0.45); at the diaphysis, lean mass, percent fat mass, leptin, osteocalcin, and age-adiponectin interaction were directly explanatory of CSA (R 2 = 0.49). The regression models exploring direct associations for vBMD were much weaker, with R 2 = 0.15 and 0.18 at the distal and diaphyseal sites, respectively. Lean mass and UCOC were associated, and the global Markov property of the graph indicated that this association was explained by osteocalcin. This study, to our

  20. Use of dual-energy computed tomography to measure skeletal-wide marrow composition and cancellous bone mineral density.

    Science.gov (United States)

    Arentsen, Luke; Hansen, Karen E; Yagi, Masashi; Takahashi, Yutaka; Shanley, Ryan; McArthur, Angela; Bolan, Patrick; Magome, Taiki; Yee, Douglas; Froelich, Jerry; Hui, Susanta K

    2017-07-01

    Temporal and spatial variations in bone marrow adipose tissue (MAT) can be indicative of several pathologies and confound current methods of assessing immediate changes in bone mineral remodeling. We present a novel dual-energy computed tomography (DECT) method to monitor MAT and marrow-corrected volumetric BMD (mcvBMD) throughout the body. Twenty-three cancellous skeletal sites in 20 adult female cadavers aged 40-80 years old were measured using DECT (80 and 140 kVp). vBMD was simultaneous recorded using QCT. MAT was further sampled using MRI. Thirteen lumbar vertebrae were then excised from the MRI-imaged donors and examined by microCT. After MAT correction throughout the skeleton, significant differences (p < 0.05) were found between QCT-derived vBMD and DECT-derived mcvBMD results. McvBMD was highly heterogeneous with a maximum at the posterior skull and minimum in the proximal humerus (574 and 0.7 mg/cc, respectively). BV/TV and BMC have a nearly significant correlation with mcvBMD (r = 0.545, p = 0.057 and r = 0.539, p = 0.061, respectively). MAT assessed by DECT showed a significant correlation with MRI MAT results (r = 0.881, p < 0.0001). Both DECT- and MRI-derived MAT had a significant influence on uncorrected vBMD (r = -0.86 and r = -0.818, p ≤ 0.0001, respectively). Conversely, mcvBMD had no correlation with DECT- or MRI-derived MAT (r = 0.261 and r = 0.067). DECT can be used to assess MAT while simultaneously collecting mcvBMD values at each skeletal site. MAT is heterogeneous throughout the skeleton, highly variable, and should be accounted for in longitudinal mcvBMD studies. McvBMD accurately reflects the calcified tissue in cancellous bone.

  1. Autologous implantation of BMP2-expressing dermal fibroblasts to improve bone mineral density and architecture in rabbit long bones.

    Science.gov (United States)

    Ishihara, Akikazu; Weisbrode, Steve E; Bertone, Alicia L

    2015-10-01

    Cell-mediated gene therapy may treat bone fragility disorders. Dermal fibroblasts (DFb) may be an alternative cell source to stem cells for orthopedic gene therapy because of their rapid cell yield and excellent plasticity with bone morphogenetic protein-2 (BMP2) gene transduction. Autologous DFb or BMP2-expressing autologous DFb were administered in twelve rabbits by two delivery routes; a transcortical intra-medullar infusion into tibiae and delayed intra-osseous injection into femoral drill defects. Both delivery methods of DFb-BMP2 resulted in a successful cell engraftment, increased bone volume, bone mineral density, improved trabecular bone microarchitecture, greater bone defect filling, external callus formation, and trabecular surface area, compared to non-transduced DFb or no cells. Cell engraftment within trabecular bone and bone marrow tissue was most efficiently achieved by intra-osseous injection of DFb-BMP2. Our results suggested that BMP2-expressing autologous DFb have enhanced efficiency of engraftment in target bones resulting in a measurable biologic response by the bone of improved bone mineral density and bone microarchitecture. These results support that autologous implantation of DFb-BMP2 warrants further study on animal models of bone fragility disorders, such as osteogenesis imperfecta and osteoporosis to potentially enhance bone quality, particularly along with other gene modification of these diseases. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  2. Development and testing of texture discriminators for the analysis of trabecular bone in proximal femur radiographs

    International Nuclear Information System (INIS)

    Huber, M. B.; Carballido-Gamio, J.; Fritscher, K.; Schubert, R.; Haenni, M.; Hengg, C.; Majumdar, S.; Link, T. M.

    2009-01-01

    and MG features, p adj 2 =0.86 (p<0.001) included a set of recently developed texture methods (MF and SIM) but excluded bone mineral density and commonly used texture measures. Conclusions: The results suggest that texture information contained in trabecular bone structure visualized on radiographs may predict whether an implant anchorage can be used and may determine the local bone quality from preoperative radiographs.

  3. Effect of persistent high intraocular pressure on microstructure and hydraulic permeability of trabecular meshwork

    International Nuclear Information System (INIS)

    Mei Xi; Ren Lin; Xu Qiang; Liu Zhi-Cheng; Zheng Wei

    2015-01-01

    As the aqueous humor leaves the eye, it first passes through the trabecular meshwork (TM). Increased flow resistance in this region causes elevation of intraocular pressure (IOP), which leads to the occurrence of glaucoma. To quantitatively evaluate the effect of high IOP on the configuration and hydraulic permeability of the TM, second harmonic generation (SHG) microscopy was used to image the microstructures of the TM and adjacent tissues in control (normal) and high IOP conditions. Enucleated rabbit eyes were perfused at a pressure of 60 mmHg to achieve the high IOP. Through the anterior chamber of the eye, in situ images were obtained from different depths beneath the surface of the TM. Porosity and specific surface area of the TM in control and high IOP conditions were then calculated to estimate the effect of the high pressure on the permeability of tissue in different depths. We further photographed the histological sections of the TM and compared the in situ images. The following results were obtained in the control condition, where the region of depth was less than 55 μm with crossed branching beams and large pores in the superficial TM. The deeper meshwork is a silk-like tissue with abundant fluorescence separating the small size of pores. The total thickness of pathway tissues composed of TM and juxtacanalicular (JCT) is more than 100 μm. After putting a high pressure on the inner wall of the eye, the TM region progressively collapses and decreases to be less than 40 μm. Fibers of the TM became dense, and the porosity at 34 μm in the high IOP condition is comparable to that at 105 μm in the control condition. As a consequent result, the permeability of the superficial TM decreases rapidly from 120 μm 2 to 49.6 μm 2 and that of deeper TM decreases from 1.66 μm 2 to 0.57 μm 2 . Heterogeneity reflected by descent in permeability reduces from 12.4 μm of the control condition to 3.74 μm of the high IOP condition. The persistently high IOP makes the

  4. GREATER OMENTUM: MORPHOFUNCTIONAL CHARACTERISTICS AND CLINICAL SIGNIFICANCE IN PEDIATRICS

    Directory of Open Access Journals (Sweden)

    A.V. Nekrutov

    2007-01-01

    Full Text Available The review analyzes the structure organization and pathophysiological age specificities of the greater omentum, which determine its uniqueness and functional diversity in a child's organism. the article discusses protective functions of the organ, its role in the development of post operative complications of children, and the usage in children's reconstructive plastic surgery.Key words: greater omentum, omentitis, of post operative complications, children.

  5. Differential Protein Expression Profiles in Glaucomatous Trabecular Meshwork: An Evaluation Study on a Small Primary Open Angle Glaucoma Population.

    Science.gov (United States)

    Micera, Alessandra; Quaranta, Luciano; Esposito, Graziana; Floriani, Irene; Pocobelli, Augusto; Saccà, Sergio Claudio; Riva, Ivano; Manni, Gianluca; Oddone, Francesco

    2016-02-01

    Primary open angle glaucoma (POAG) is a progressive optic neuropathy characterized by impaired aqueous outflow and extensive remodeling in the trabecular meshwork (TM). The aim of this study was to characterize and compare the expression patterns of selected proteins belonging to the tissue remodeling, inflammation and growth factor pathways in ex vivo glaucomatous and post-mortem TMs using protein-array analysis. TM specimens were collected from 63 white subjects, including 40 patients with glaucoma and 23 controls. Forty POAG TMs were collected at the time of surgery and 23 post-mortem specimens were from non-glaucomatous donor sclerocorneal tissues. Protein profiles were evaluated using a chip-based array consisting of 60 literature-selected antibodies. A different expression of some factors was observed in POAG TMs with respect to post-mortem specimens, either in abundance (interleukin [IL]10, IL6, IL5, IL7, IL12, IL3, macrophage inflammatory protein [MIP]1δ/α, vascular endothelial growth factor [VEGF], transforming growth factor beta 1 [TGFβ1], soluble tumor necrosis factor receptor I [sTNFRI]) or in scarcity (IL16, IL18, intercellular adhesion molecule 3 [ICAM3], matrix metalloproteinase-7 [MMP7], tissue inhibitor of metalloproteinase 1 [TIMP1]). MMP2, MMP7, TGFβ1, and VEGF expressions were confirmed by Western blot, zymography, and polymerase chain reaction. No difference in protein profile expression was detected between glaucomatous subtypes. The analysis of this small TM population highlighted some proteins linked to POAG, some previously reported and others of new detection (IL7, MIPs, sTNFαRI). A larger POAG population is required to select promising disease-associated biomarker candidates. This study was partially supported by the Fondazione Roma, the Italian Ministry of Health and the "National 5xMille 2010 tax donation to IRCCS-G.B. Bietti Foundation".

  6. Morphobiochemical diagnosis of acute trabecular microfractures using gamma correction Tc-99m HDP pinhole bone scan with histopathological verification.

    Science.gov (United States)

    Bahk, Yong-Whee; Hwang, Seok-Ha; Lee, U-Young; Chung, Yong-An; Jung, Joo-Young; Jeong, Hyeonseok S

    2017-11-01

    We prospectively performed gamma correction pinhole bone scan (GCPBS) and histopathologic verification study to make simultaneous morphobiochemical diagnosis of trabecular microfractures (TMF) occurred in the femoral head as a part of femoral neck fracture.Materials consisted of surgical specimens of the femoral head in 6 consecutive patients. The specimens were imaged using Tc-99m hydroxymethylene diphosphonate (HDP) pinhole scan and processed by the gamma correction. After cleansing with 10% formalin solution, injured specimen surface was observed using a surgical microscope to record TMF. Morphological findings shown in the photograph, naive pinhole bone scan, GCPBS, and hematoxylin-eosin (H&E) stain of the specimen were reciprocally correlated for histological verification and the usefulness of suppression and enhancement of Tc-99m HDP uptake was biochemically investigated in TMF and edema and hemorrhage using gamma correction.On the one hand, GCPBS was able to depict the calcifying calluses in TMF with enhanced Tc-99m HDP uptake. They were pinpointed, speckled, round, ovoid, rod-like, geographic, and crushed in shape. The smallest callus measured was 0.23 mm in this series. On the other hand, GCPBS biochemically was able to discern the calluses with enhanced high Tc-99m HDP uptake from the normal and edema dipped and hemorrhage irritated trabeculae with washed out uptake.Morphobiochemically, GCPBS can clearly depict microfractures in the femoral head produced by femoral neck fracture. It discerns the microcalluses with enhanced Tc-99m HDP uptake from the intact and edema dipped and hemorrhage irritated trabeculae with suppressed washed out Tc-99m HDP uptake. Both conventional pinhole bone scan and gamma correction are useful imaging means to specifically diagnose the microcalluses naturally formed in TMF.

  7. Temperature oscillations drive cycles in the activity of MMP-2,9 secreted by a human trabecular meshwork cell line.

    Science.gov (United States)

    Li, Stanley Ka-Lok; Banerjee, Juni; Jang, Christopher; Sehgal, Amita; Stone, Richard A; Civan, Mortimer M

    2015-02-05

    Aqueous humor inflow falls 50% during sleeping hours without proportional fall in IOP, partly reflecting reduced outflow facility. The mechanisms underlying outflow facility cycling are unknown. One outflow facility regulator is matrix metalloproteinase (MMP) release from trabecular meshwork (TM) cells. Because anterior segment temperature must oscillate due to core temperature cycling and eyelid closure during sleep, we tested whether physiologically relevant temperature oscillations drive cycles in the activity of secreted MMP. Temperature of transformed normal human TM cells (hTM5 line) was fixed or alternated 12 hours/12 hours between 33°C and 37°C. Activity of secreted MMP-2 and MMP-9 was measured by zymography, and gene expression by RT-PCR and quantitative PCR. Raising temperature to 37°C increased, and lowering to 33°C reduced, activity of secreted MMP. Switching between 37°C and 33°C altered MMP-9 by 40% ± 3% and MMP-2 by 22% ± 2%. Peripheral circadian clocks did not mediate temperature-driven cycling of MMP secretion because MMP-release oscillations did not persist at constant temperature after 3 to 6 days of alternating temperatures, and temperature cycles did not entrain clock-gene expression in these cells. Furthermore, inhibiting heat shock transcription factor 1, which links temperature and peripheral clock-gene oscillations, inhibited MMP-9 but not MMP-2 temperature-driven MMP cycling. Inhibition of heat-sensitive TRPV1 channels altered total MMP secretion but not temperature-induced modulations. Inhibiting cold-sensitive TRPM-8 channels had no effect. Physiologically relevant temperature oscillations drive fluctuations of secreted MMP-2 and MMP-9 activity in hTM5 cells independent of peripheral clock genes and temperature-sensitive TRP channels. Copyright 2015 The Association for Research in Vision and Ophthalmology, Inc.

  8. More features, greater connectivity.

    Science.gov (United States)

    Hunt, Sarah

    2015-09-01

    Changes in our political infrastructure, the continuing frailties of our economy, and a stark growth in population, have greatly impacted upon the perceived stability of the NHS. Healthcare teams have had to adapt to these changes, and so too have the technologies upon which they rely to deliver first-class patient care. Here Sarah Hunt, marketing co-ordinator at Aid Call, assesses how the changing healthcare environment has affected one of its fundamental technologies - the nurse call system, argues the case for wireless such systems in terms of what the company claims is greater adaptability to changing needs, and considers the ever-wider range of features and functions available from today's nurse call equipment, particularly via connectivity with both mobile devices, and ancillaries ranging from enuresis sensors to staff attack alert 'badges'.

  9. Greater Sudbury fuel efficient driving handbook

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-12-15

    Reducing the amount of fuel that people use for personal driving saves money, improves local air quality, and reduces personal contributions to climate change. This handbook was developed to be used as a tool for a fuel efficient driving pilot program in Greater Sudbury in 2009-2010. Specifically, the purpose of the handbook was to provide greater Sudbury drivers with information on how to drive and maintain their personal vehicles in order to maximize fuel efficiency. The handbook also provides tips for purchasing fuel efficient vehicles. It outlines the benefits of fuel maximization, with particular reference to reducing contributions to climate change; reducing emissions of air pollutants; safe driving; and money savings. Some tips for efficient driving are to avoid aggressive driving; use cruise control; plan trips; and remove excess weight. Tips for efficient winter driving are to avoid idling to warm up the engine; use a block heater; remove snow and ice; use snow tires; and check tire pressure. The importance of car maintenance and tire pressure was emphasized. The handbook also explains how fuel consumption ratings are developed by vehicle manufacturers. refs., figs.

  10. Risk Stratification of Stress Fractures and Prediction of Return-to-Duty

    Science.gov (United States)

    2016-12-01

    mgh.harvard.edu; mbouxsei@bidmc.harvard.edu 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Massachusetts General Hospital AND...ADDRESS(ES) 8. PERFORMING ORGANIZATION REPORT NUMBER Boston, MA 02114-2554 9. SPONSORING / MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSOR...with recent stress fracture enrolled. 15. SUBJECT TERMS bone microarchitecture, HRpQCT, race, gender , sex, bone mineral density, vBMD, bone geometry

  11. Greater general startle reflex is associated with greater anxiety levels: a correlational study on 111 young women

    Directory of Open Access Journals (Sweden)

    Eleonora ePoli

    2015-02-01

    Full Text Available Startle eyeblink reflex is a valid non-invasive tool for studying attention, emotion and psychiatric disorders. In the absence of any experimental manipulation, the general (or baseline startle reflex shows a high inter-individual variability, which is often considered task-irrelevant and therefore normalized across participants. Unlike the above view, we hypothesized that greater general startle magnitude is related to participants’ higher anxiety level. 111 healthy young women, after completing the State-Trait Anxiety Inventory, were randomly administered 10 acoustic white noise probes (50 ms, 100 dBA acoustic level while integrated EMG from left and right orbicularis oculi was recorded. Results showed that participants with greater state anxiety levels exhibited larger startle reflex magnitude from the left eye (r109=0.23, p<0.05. Furthermore, individuals who perceived the acoustic probe as more aversive reported the largest anxiety scores (r109=0.28, p<0.05 and had the largest eyeblinks, especially in the left eye (r109 = 0.34, p<0.001. Results suggest that general startle may represent a valid tool for studying the neural excitability underlying anxiety and emotional dysfunction in neurological and mental disorders.

  12. Ethnic Differences in Peripheral Skeletal Development Among Urban South African Adolescents: A Ten-Year Longitudinal pQCT Study.

    Science.gov (United States)

    Schoenbuchner, Simon M; Pettifor, John M; Norris, Shane A; Micklesfield, Lisa K; Prentice, Ann; Ward, Kate A

    2017-12-01

    There are no longitudinal pQCT data of bone growth and development from sub-Saharan Africa, where rapid environmental, societal, and economic transitions are occurring, and where fracture rates are predicted to rise. The aim of this study was to compare skeletal development in black and white South African adolescents using longitudinal data from the Birth to Twenty study. The Birth to Twenty Bone Health subcohort consisted of 543 adolescents (261 [178 black] girls, 282 [201 black] boys). Annual pQCT measurements of the radial and tibial metaphysis and diaphysis were obtained between ages 12 and 22 years (distal metaphysis: cross-sectional area [CSA] and trabecular bone mineral density [BMD]; diaphysis: total and cortical CSA, cortical BMD, and polar stress-strain index [SSIp]). Age at peak height velocity (APHV) was calculated to account for differences in maturational timing between ethnic groups and sexes. Mixed-effects models were used to describe trajectories for each pQCT outcome. Likelihood-ratio tests were used to summarize the overall difference in trajectories between black and white participants within each sex. APHV (mean ± SD years) was similar in black (11.8 ± 0.8) and white (12.2 ± 1.0) girls, but delayed in black (14.2 ± 1.0) relative to white boys (13.3 ± 0.8). By 4 years post-APHV, white adolescents had significantly greater cortical CSA and SSIp than black adolescents at the radius. There were no significant differences at the radial metaphysis but there was some divergence, such that black adolescents had greater radial trabecular BMD by the end of follow-up. At the tibia, white adolescents had lower diaphyseal CSA and SSIp, and greater metaphyseal CSA. There was no ethnic difference in tibial trabecular BMD. There are ethnic differences in bone growth and development, independent of maturation, in South African adolescents. This work gives new insights into the possible etiology of childhood fractures, which occur most

  13. Visceral Adipose Tissue Is Associated With Bone Microarchitecture in the Framingham Osteoporosis Study.

    Science.gov (United States)

    Liu, Ching-Ti; Broe, Kerry E; Zhou, Yanhua; Boyd, Steven K; Cupples, L Adrienne; Hannan, Marian T; Lim, Elise; McLean, Robert R; Samelson, Elizabeth J; Bouxsein, Mary L; Kiel, Douglas P

    2017-01-01

    Obesity has been traditionally considered to protect the skeleton against osteoporosis and fracture. Recently, body fat, specifically visceral adipose tissue (VAT), has been associated with lower bone mineral density (BMD) and increased risk for some types of fractures. We studied VAT and bone microarchitecture in 710 participants (58% women, age 61.3 ± 7.7 years) from the Framingham Offspring cohort to determine whether cortical and trabecular BMD and microarchitecture differ according to the amount of VAT. VAT was measured from CT imaging of the abdomen. Cortical and trabecular BMD and microarchitecture were measured at the distal tibia and radius using high-resolution peripheral quantitative computed tomography (HR-pQCT). We focused on 10 bone parameters: cortical BMD (Ct.BMD), cortical tissue mineral density (Ct.TMD), cortical porosity (Ct.Po), cortical thickness (Ct.Th), cortical bone area fraction (Ct.A/Tt.A), trabecular density (Tb.BMD), trabecular number (Tb.N), trabecular thickness (Tb.Th), total area (Tt.Ar), and failure load (FL) from micro-finite element analysis. We assessed the association between sex-specific quartiles of VAT and BMD, microarchitecture, and strength in all participants and stratified by sex. All analyses were adjusted for age, sex, and in women, menopausal status, then repeated adjusting for body mass index (BMI) or weight. At the radius and tibia, Ct.Th, Ct.A/Tt.A, Tb.BMD, Tb.N, and FL were positively associated with VAT (all p-trend <0.05), but no other associations were statistically significant except for higher levels of cortical porosity with higher VAT in the radius. Most of these associations were only observed in women, and were no longer significant when adjusting for BMI or weight. Higher amounts of VAT are associated with greater BMD and better microstructure of the peripheral skeleton despite some suggestions of significant deleterious changes in cortical measures in the non-weight bearing radius. Associations were

  14. Observations of territorial breeding common ravens caching eggs of greater sage-grouse

    Science.gov (United States)

    Howe, Kristy B.; Coates, Peter S.

    2015-01-01

    Previous investigations using continuous video monitoring of greater sage-grouse Centrocercus urophasianus nests have unambiguously identified common ravens Corvus corax as an important egg predator within the western United States. The quantity of greater sage-grouse eggs an individual common raven consumes during the nesting period and the extent to which common ravens actively hunt greater sage-grouse nests are largely unknown. However, some evidence suggests that territorial breeding common ravens, rather than nonbreeding transients, are most likely responsible for nest depredations. We describe greater sage-grouse egg depredation observations obtained opportunistically from three common raven nests located in Idaho and Nevada where depredated greater sage-grouse eggs were found at or in the immediate vicinity of the nest site, including the caching of eggs in nearby rock crevices. We opportunistically monitored these nests by counting and removing depredated eggs and shell fragments from the nest sites during each visit to determine the extent to which the common raven pairs preyed on greater sage-grouse eggs. To our knowledge, our observations represent the first evidence that breeding, territorial pairs of common ravens cache greater sage-grouse eggs and are capable of depredating multiple greater sage-grouse nests.

  15. Comparative Education in Greater China: Contexts, Characteristics, Contrasts and Contributions.

    Science.gov (United States)

    Bray, Mark; Qin, Gui

    2001-01-01

    The evolution of comparative education in Greater China (mainland China, Taiwan, Hong Kong, and Macau) has been influenced by size, culture, political ideologies, standard of living, and colonialism. Similarities and differences in conceptions of comparative education are identified among the four components and between Greater China and other…

  16. Velocity Drives Greater Power Observed During Back Squat Using Cluster Sets.

    Science.gov (United States)

    Oliver, Jonathan M; Kreutzer, Andreas; Jenke, Shane C; Phillips, Melody D; Mitchell, Joel B; Jones, Margaret T

    2016-01-01

    This investigation compared the kinetics and kinematics of cluster sets (CLU) and traditional sets (TRD) during back squat in trained (RT) and untrained (UT) men. Twenty-four participants (RT = 12, 25 ± 1 year, 179.1 ± 2.2 cm, 84.6 ± 2.1 kg; UT = 12, 25 ± 1 year, 180.1 ± 1.8 cm, 85.4 ± 3.8 kg) performed TRD (4 × 10, 120-second rest) and CLU (4 × (2 × 5) 30 seconds between clusters; 90 seconds between sets) with 70% one repetition maximum, randomly. Kinematics and kinetics were sampled through force plate and linear position transducers. Resistance-trained produced greater overall force, velocity, and power; however, similar patterns were observed in all variables when comparing conditions. Cluster sets produced significantly greater force in isolated repetitions in sets 1-3, while consistently producing greater force due to a required reduction in load during set 4 resulting in greater total volume load (CLU, 3302.4 ± 102.7 kg; TRD, 3274.8 ± 102.8 kg). Velocity loss was lessened in CLU resulting in significantly higher velocities in sets 2 through 4. Furthermore, higher velocities were produced by CLU during later repetitions of each set. Cluster sets produced greater power output for an increasing number of repetitions in each set (set 1, 5 repetitions; sets 2 and 3, 6 repetitions; set 4, 8 repetitions), and the difference between conditions increased over subsequent sets. Time under tension increased over each set and was greater in TRD. This study demonstrates greater power output is driven by greater velocity when back squatting during CLU; therefore, velocity may be a useful measure by which to assess power.

  17. Active convergence between the Lesser and Greater Caucasus in Georgia: Constraints on the tectonic evolution of the Lesser-Greater Caucasus continental collision

    Science.gov (United States)

    Sokhadze, G.; Floyd, M.; Godoladze, T.; King, R.; Cowgill, E. S.; Javakhishvili, Z.; Hahubia, G.; Reilinger, R.

    2018-01-01

    We present and interpret newly determined site motions derived from GPS observations made from 2008 through 2016 in the Republic of Georgia, which constrain the rate and locus of active shortening in the Lesser-Greater Caucasus continental collision zone. Observation sites are located along two ∼160 km-long profiles crossing the Lesser-Greater Caucasus boundary zone: one crossing the Rioni Basin in western Georgia and the other crossing further east near the longitude of Tbilisi. Convergence across the Rioni Basin Profile occurs along the southern margin of the Greater Caucasus, near the surface trace of the north-dipping Main Caucasus Thrust Fault (MCTF) system, and is consistent with strain accumulation on the fault that generated the 1991 MW6.9 Racha earthquake. In contrast, convergence along the Tbilisi Profile occurs near Tbilisi and the northern boundary of the Lesser Caucasus (near the south-dipping Lesser Caucasus Thrust Fault), approximately 50-70 km south of the MCTF, which is inactive within the resolution of geodetic observations (< ± 0.5 mm/yr) at the location of the Tbilisi Profile. We suggest that the southward offset of convergence along strike of the range is related to the incipient collision of the Lesser-Greater Caucasus, and closing of the intervening Kura Basin, which is most advanced along this segment of the collision zone. The identification of active shortening near Tbilisi requires a reevaluation of seismic hazards in this area.

  18. Estrogen depletion and drug treatment alter the microstructure of type I collagen in bone

    Directory of Open Access Journals (Sweden)

    Meagan A. Cauble

    2016-12-01

    Full Text Available The impact of estrogen depletion and drug treatment on type I collagen fibril nanomorphology and collagen fibril packing (microstructure was evaluated by atomic force microscopy (AFM using an ovariectomized (OVX rabbit model of estrogen deficiency induced bone loss. Nine month-old New Zealand white female rabbits were treated as follows: sham-operated (Sham; n = 11, OVX + vehicle (OVX + Veh; n = 12, OVX + alendronate (ALN, 600 μg/kg/wk., s.c.; n = 12, and OVX + cathepsin-K inhibitor L-235 (CatKI, 10 mg/kg, daily, p.o.; n = 13 in prevention mode for 27 weeks. Samples from the cortical femur and trabecular lumbar vertebrae were polished, demineralized, and imaged using AFM. Auto-correlation of image patches was used to generate a vector field for each image that mathematically approximated the collagen fibril alignment. This vector field was used to compute an information-theoretic entropy that was employed as a quantitative fibril alignment parameter (FAP to allow image-to-image and sample-to-sample comparison. For all samples, no change was observed in the average FAP values; however significant differences in the distribution of FAP values were observed. In particular, OVX + Veh lumbar vertebrae samples contained a tail of lower FAP values representing regions of greater fibril alignment. OVX + ALN treatment resulted in a FAP distribution with a tail indicating greater alignment for cortical femur and less alignment for trabecular lumbar vertebrae. OVX + CatKI treatment gave a distribution of FAP values with a tail indicating less alignment for cortical femur and no change for trabecular lumbar vertebrae. Fibril alignment was also evaluated by considering when a fibril was part of discrete bundles or sheets (classified as parallel or not (classified as oblique. For this analysis, the percentage of parallel fibrils in cortical femur for the OVX group was 17% lower than the Sham group. OVX + ALN treatment partially

  19. Breeding of Greater and Lesser Flamingos at Sua Pan, Botswana ...

    African Journals Online (AJOL)

    to fledging was unknown owing to the rapid drying of the pan in late March 1999. No Greater Flamingo breeding was seen that season. Exceptional flooding during 1999–2000 produced highly favourable breeding conditions, with numbers of Greater and Lesser Flamingos breeding estimated to be 23 869 and 64 287 pairs, ...

  20. Surgical anatomy of greater occipital nerve and its relation to ...

    African Journals Online (AJOL)

    Introduction: The knowledge of the anatomy of greater occipital nerve and its relation to occipital artery is important for the surgeon. Blockage or surgical release of greater occipital nerve is clinically effective in reducing or eliminating chronic migraine symptoms. Aim: The aim of this research was to study the anatomy of ...

  1. Surgical anatomy of greater occipital nerve and its relation to ...

    African Journals Online (AJOL)

    Nancy Mohamed El Sekily

    2014-08-19

    Aug 19, 2014 ... Abstract Introduction: The knowledge of the anatomy of greater occipital nerve and its relation to occipital artery is important for the surgeon. Blockage or surgical release of greater occipital nerve is clinically effective in reducing or eliminating chronic migraine symptoms. Aim: The aim of this research was to ...

  2. Bone mineral content (BMC) of the lumbar vertebrae (L2-L4) measured by quantitative computed tomography (QCT) and dual energy X-ray absorptiometry (DXA) in 21 hemodialysis (HD) patients

    International Nuclear Information System (INIS)

    Takahashi, Nobuyoshi; Suzuki, Tadashi; Sato, Motoaki; Oh, Songchol; Sato, Atsushi; Saito, Hisao; Funyu, Tomihisa.

    1996-01-01

    BMC of lumbar vertebrae (L2-L4) was measured by QCT and DXA in 21 HD patients. The effect of sex, aging, HD duration, postmenopausal years and various blood parameters of bone metabolism on BMC was assessed statistically. BMC showed a good positive correlation not only with DXA and QCT (trabecular and cortical bone), but with QCT (trabecular bone) and QCT (cortical bone). A significant age-related decrease in BMC, particularly by QCT (trabecular bone), was found in both sexes. BMC measured by QCT (trabecular bone) increased with the duration of HD in male patients. A negative relationship between postmenopausal years and BMC measured by QCT (trabecular and cortical bone) was prominent. BMC was not found to be correlated with various blood parameters of bone metabolism. Thus, measurement of BMC (L2-L4) by QCT has the advantage of allowing more precise examination of changes in cortical and trabecular bone. (author)

  3. Technical concept for a Greater Confinement Disposal test facility

    International Nuclear Information System (INIS)

    Hunter, P.H.

    1982-01-01

    For the past two years, Ford, Bacon and Davis has been performing technical services for the Department of Energy at the Nevada Test Site in specific development of defense low-level waste management concepts for greater confinement disposal concept with particular application to arid sites. The investigations have included the development of Criteria for Greater Confinement Disposal, NVO-234, which was published in May of 1981 and the draft of the technical concept for Greater Confinement Disposal, with the latest draft published in November 1981. The final draft of the technical concept and design specifications are expected to be published imminently. The document is prerequisite to the actual construction and implementation of the demonstration facility this fiscal year. The GCD Criteria Document, NVO-234 is considered to contain information complimentary and compatible with that being developed for the reserved section 10 CFR 61.51b of the NRCs proposed licensing rule for low level waste disposal facilities

  4. Fibroma osificante juvenil trabecular mandibular: presentación de un caso con reconstrucción inmediata mediante un injerto libre de la cresta ilíaca y costocondral

    Directory of Open Access Journals (Sweden)

    Rodrigo Bravo Ahumada

    2015-01-01

    Full Text Available El fibroma osificante juvenil (FOJ es una lesión fibro-ósea benigna pero con potencial biológico agresivo que afecta al esqueleto craneofacial. Su evolución clínica es rápida, manifestándose principalmente por una asimetría facial de poco tiempo de evolución. Radiográficamente es una lesión radiolúcida uni o multilocular bien definida con contenido radiopaco variable. El tratamiento puede variar dependiendo de las características clínicas, imagenológicas e histopatológicas específicas de cada lesión, sin embargo, un tratamiento agresivo con resección es el más indicado. Se presenta un caso de un niño con extenso FOJ trabecular (FOJT mandibular. Se realizó la resección completa de la lesión con un margen de seguridad y reconstrucción inmediata con un injerto de la cresta ilíaca y costocondral. Se realizaron controles postoperatorios durante 7 años en los que no se observaron signos de recidiva asociados a una reconstrucción funcional y estética exitosa.

  5. Epiphyseal abnormalities, trabecular bone loss and articular chondrocyte hypertrophy develop in the long bones of postnatal Ext1-deficient mice.

    Science.gov (United States)

    Sgariglia, Federica; Candela, Maria Elena; Huegel, Julianne; Jacenko, Olena; Koyama, Eiki; Yamaguchi, Yu; Pacifici, Maurizio; Enomoto-Iwamoto, Motomi

    2013-11-01

    Long bones are integral components of the limb skeleton. Recent studies have indicated that embryonic long bone development is altered by mutations in Ext genes and consequent heparan sulfate (HS) deficiency, possibly due to changes in activity and distribution of HS-binding/growth plate-associated signaling proteins. Here we asked whether Ext function is continuously required after birth to sustain growth plate function and long bone growth and organization. Compound transgenic Ext1(f/f);Col2CreERT mice were injected with tamoxifen at postnatal day 5 (P5) to ablate Ext1 in cartilage and monitored over time. The Ext1-deficient mice exhibited growth retardation already by 2weeks post-injection, as did their long bones. Mutant growth plates displayed a severe disorganization of chondrocyte columnar organization, a shortened hypertrophic zone with low expression of collagen X and MMP-13, and reduced primary spongiosa accompanied, however, by increased numbers of TRAP-positive osteoclasts at the chondro-osseous border. The mutant epiphyses were abnormal as well. Formation of a secondary ossification center was significantly delayed but interestingly, hypertrophic-like chondrocytes emerged within articular cartilage, similar to those often seen in osteoarthritic joints. Indeed, the cells displayed a large size and round shape, expressed collagen X and MMP-13 and were surrounded by an abundant Perlecan-rich pericellular matrix not seen in control articular chondrocytes. In addition, ectopic cartilaginous outgrowths developed on the lateral side of mutant growth plates over time that resembled exostotic characteristic of children with Hereditary Multiple Exostoses, a syndrome caused by Ext mutations and HS deficiency. In sum, the data do show that Ext1 is continuously required for postnatal growth and organization of long bones as well as their adjacent joints. Ext1 deficiency elicits defects that can occur in human skeletal conditions including trabecular bone loss

  6. Effects of low calcium plus high aluminum diet on magnesium and calcium contents in spinal cord and trabecular bone of rats

    Energy Technology Data Exchange (ETDEWEB)

    Yasui, Masayuki; Ota, Kiichiro [Wakayama Medical Coll. (Japan); Sasajima, Kazuhisa

    1998-01-01

    Current epidemiological surveys in the Western Pacific area and Kii Peninsula have suggested that low calcium (Ca), magnesium (Mg), and high aluminum (Al) and manganese (Mn) in river, soil and drinking water may be implicated in the pathogenetic process of amyotrophic lateral sclerosis (ALS) and parkinsonism-dementia (PD). The condition of unbalanced minerals was experimentally duplicated in this study using rats. Male Wistar rats, weighing 200 g, were maintained for 60 days on the following diets: (A) standard diet, (B) low Ca diet, (C) low Ca diet with high Al. Magnesium concentration was determined in spinal cord and trabecular bone using inductively coupled plasma emission spectrometry (ICP) and the calcium concentration was determined using neutron activation method. In the group maintained on low Ca high Al diet, magnesium content of the spinal cord was lower than the group fed standard diet. Also, magnesium content of lumbar bone showed lower values in the unbalanced diet group fed low Ca high Al diet than those in the standard diet and low Ca diet groups. Calcium content of spinal cord was highest in rats maintained on low Ca high Al diet. Calcium content in lumbar bone of rats significantly decreased in rats maintained on the low Ca diet (group B and C) compared to rats given a standard diet (group A). Our data indicate that low Ca and high Al dietary intake influence Mg concentration in bone and central nervous system (CNS) tissues and that low Ca and high Al diet diminish Mg in bone and CNS tissues, thereby inducing loss of calcification in bone and degeneration of CNS tissues due to disturbance of the normal biological effects of Mg. (author)

  7. Exposure to Low-Dose X-Ray Radiation Alters Bone Progenitor Cells and Bone Microarchitecture.

    Science.gov (United States)

    Lima, Florence; Swift, Joshua M; Greene, Elisabeth S; Allen, Matthew R; Cunningham, David A; Braby, Leslie A; Bloomfield, Susan A

    2017-10-01

    Exposure to high-dose ionizing radiation during medical treatment exerts well-documented deleterious effects on bone health, reducing bone density and contributing to bone growth retardation in young patients and spontaneous fracture in postmenopausal women. However, the majority of human radiation exposures occur in a much lower dose range than that used in the radiation oncology clinic. Furthermore, very few studies have examined the effects of low-dose ionizing radiation on bone integrity and results have been inconsistent. In this study, mice were irradiated with a total-body dose of 0.17, 0.5 or 1 Gy to quantify the early (day 3 postirradiation) and delayed (day 21 postirradiation) effects of radiation on bone microarchitecture and bone marrow stromal cells (BMSCs). Female BALBc mice (4 months old) were divided into four groups: irradiated (0.17, 0.5 and 1 Gy) and sham-irradiated controls (0 Gy). Micro-computed tomography analysis of distal femur trabecular bone from animals at day 21 after exposure to 1 Gy of X-ray radiation revealed a 21% smaller bone volume (BV/TV), 22% decrease in trabecular numbers (Tb.N) and 9% greater trabecular separation (Tb.Sp) compared to sham-irradiated controls (P X-rays, whereas osteoclastogenesis was enhanced. A better understanding of the effects of radiation on osteoprogenitor cell populations could lead to more effective therapeutic interventions that protect bone integrity for individuals exposed to low-dose ionizing radiation.

  8. Butterfly valves: greater use in power plants

    International Nuclear Information System (INIS)

    McCoy, M.

    1975-01-01

    Improvements in butterfly valves, particularly in the areas of automatic control and leak tightness are described. The use of butterfly valves in nuclear power plants is discussed. These uses include service in component cooling, containment cooling, and containment isolation. The outlook for further improvements and greater uses is examined. (U.S.)

  9. Bone Response to Dietary Co-Enrichment with Powdered Whole Grape and Probiotics

    Directory of Open Access Journals (Sweden)

    Cynthia Blanton

    2018-01-01

    Full Text Available Nutrition is a primary modifiable determinant of chronic noncommunicable disease, including osteoporosis. An etiology of osteoporosis is the stimulation of bone-resorbing osteoclasts by reactive oxygen species (ROS. Dietary polyphenols and probiotics demonstrate protective effects on bone that are associated with reduced ROS formation and suppressed osteoclast activity. This study tested the effect of dietary enrichment with powdered whole grape and probiotics (composed of equal parts Bifidobacterium bifidum, B. breve, Lactobacillus casei, L. plantarum, and L. bulgaricus on bone microarchitecture in a mouse model of age-related osteoporosis. Groups (n = 7 each of 10-month-old male mice were fed one of six diets for 6 months: 10% grape powder with sugar corrected to 20%; 20% grape powder; 1% probiotic with sugar corrected to 20%; 10% grape powder + 1% probiotic with sugar corrected to 20%; 20% grape powder + 1% probiotic; 20% sugar control. Femur, tibia and 4th lumbar vertebrae from 10-month-old mice served as comparator baseline samples. Bone microarchitecture was measured by micro-computed tomography and compared across diet groups using analysis of variance. Aging exerted a significant effect on tibia metaphysis trabecular bone, with baseline 10-month-old mice having significantly higher bone volume/total volume (BV/TV and trabecular number measurements and lower trabecular spacing measurements than all 16-month-old groups (p < 0.001. Neither grape nor probiotic enrichment significantly improved bone microarchitecture during aging compared to control diet. The combination of 20% grape + 1% probiotic exerted detrimental effects on tibia metaphysis BV/TV compared to 10% grape + 1% probiotic, and trabecular number and trabecular spacing compared to 10% grape + 1% probiotic, 1% probiotic and control groups (p < 0.05. Femur metaphysis trabecular bone displayed less pronounced aging effects than tibia bone, but also showed detrimental effects of the

  10. Expatriate job performance in Greater China: Does age matter?

    DEFF Research Database (Denmark)

    Selmer, Jan; Lauring, Jakob; Feng, Yunxia

    to expatriates in Chinese societies. It is possible that older business expatriates will receive more respect and be treated with more deference in a Chinese cultural context than their apparently younger colleagues. This may have a positive impact on expatriates’ job performance. To empirically test...... this presumption, business expatriates in Greater Chine were targeted by a survey. Controlling for the potential bias of a number of background variables, results indicate that contextual/managerial performance, including general managerial functions applied to the subsidiary in Greater China, had a positive...

  11. Absenteeism movement in Greater Poland in 1840–1902

    OpenAIRE

    Izabela Krasińska

    2013-01-01

    The article presents the origins and development of the idea of absenteeism in Greater Poland in the 19th century. The start date for the research is 1840, which is considered to be a breakthrough year in the history of an organized absenteeism movement in Greater Poland. It was due to the Association for the Suppression of the Use of Vodka (Towarzystwo ku Przytłumieniu Używania Wódki) in the Great Duchy of Posen that was then established in Kórnik. It was a secular organization that came int...

  12. Gender differences in commuting behavior: Women's greater sensitivity

    Energy Technology Data Exchange (ETDEWEB)

    Olmo Sanchez, M.I.; Maeso Gonzalez, E.

    2016-07-01

    Women's greater sensitivity to changes in their environment is one of the most distinguishing features between both genders. This article raises women's greater sensitivity to the different variables which influence their commuting modal choice. In order to do this, gender gaps detected in the choice of means of transport in commuting trips with respect to the decision factors such as age, education level, driver's license, private transport access; location, household size and net income, are quantified.The results show a greater female sensitivity to the different variables that affect their modal choice, which helps to better understand the different mobility patterns and it is useful for planning measures favoring sustainable mobility policies and equity. (Author)

  13. Development and testing of texture discriminators for the analysis of trabecular bone in proximal femur radiographs

    Energy Technology Data Exchange (ETDEWEB)

    Huber, M. B.; Carballido-Gamio, J.; Fritscher, K.; Schubert, R.; Haenni, M.; Hengg, C.; Majumdar, S.; Link, T. M. [Department of Radiology and Biomedical Imaging, University of California, 400 Parnassus Avenue, San Francisco, California 94143 (United States); University of Health Sciences, Medical Informatics and Technology, 6060 Hall (Austria); AO Development Institute, 7270 Davos Platz (Switzerland); Medical University Innsbruck, 6020 Innsbruck (Austria); Department of Radiology and Biomedical Imaging, University of California, 400 Parnassus Avenue, San Francisco, California 94143 (United States)

    2009-11-15

    }=0.61 (MF and MG features, p<0.01) and were partially independent of BMD. The correlations were dependent on the choice of the ROI and the texture measure. The best predictive multiregression model for failure load R{sub adj}{sup 2}=0.86 (p<0.001) included a set of recently developed texture methods (MF and SIM) but excluded bone mineral density and commonly used texture measures. Conclusions: The results suggest that texture information contained in trabecular bone structure visualized on radiographs may predict whether an implant anchorage can be used and may determine the local bone quality from preoperative radiographs.

  14. [Autoerotic fatalities in Greater Dusseldorf].

    Science.gov (United States)

    Hartung, Benno; Hellen, Florence; Borchard, Nora; Huckenbeck, Wolfgang

    2011-01-01

    Autoerotic fatalities in the Greater Dusseldorf area correspond to the relevant medicolegal literature. Our results included exclusively young to middle-aged, usually single men who were found dead in their city apartments. Clothing and devices used showed a great variety. Women's or fetish clothing and complex shackling or hanging devices were disproportionately frequent. In most cases, death occurred due to hanging or ligature strangulation. There was no increased incidence of underlying psychiatric disorders. In most of the deceased no or at least no remarkable alcohol intoxication was found. Occasionally, it may be difficult to reliably differentiate autoerotic accidents, accidents occurring in connection with practices of bondage & discipline, dominance & submission (BDSM) from natural death, suicide or homicide.

  15. Radiographic features of tuberculous osteitis in greater trochanter and lschium

    International Nuclear Information System (INIS)

    Hahm, So Hee; Lee, Ye Ri; Kim, Dong Jin; Sung, Ki Jun; Lim, Jong Nam

    1996-01-01

    To evaluate, if possible, the radiographic features of tuberculous osteitis in the greater trochanter and ischium, and to determine the cause of the lesions. We reterospectively reviewed the plain radiographic findings of 14 ptients with histologically proven tuberculous osteitis involving the greater trochanter and ischium. In each case, the following were analyzed:morphology of bone destruction, including cortical erosion;periosteal reaction;presence or abscence of calcific shadows in adjacent soft tissue. On the basis of an analysis of radiographic features and correlation of the anatomy with adjacent structures we attempted to determine causes. Of the 14 cases evaluated, 12 showed varrious degrees of extrinsic erosion on the outer cortical bone of the greater trochanter and ischium ; in two cases, bone destruction was so severe that the radiographic features of advanced perforated osteomyelitis were simulated. In addition to findings of bone destruction, in these twelve cases, the presence of sequestrum or calcific shadows was seen in adjacent soft tissue. Tuberculous osteitis in the greater trochanter and ischium showed the characteristic findings of chronic extrinsic erosion. On the basis of these findings we can suggest that these lesions result from an extrinsic pathophysiologic cause such as adjacent bursitis

  16. Radiographic features of tuberculous osteitis in greater trochanter and lschium

    Energy Technology Data Exchange (ETDEWEB)

    Hahm, So Hee; Lee, Ye Ri [Hanil Hospital Affiliated to KEPCO, Seoul (Korea, Republic of); Kim, Dong Jin; Sung, Ki Jun [Yonsei Univ. Wonju College of Medicine, Wonju (Korea, Republic of); Lim, Jong Nam [Konkuk Univ. College of Medicine, Seoul (Korea, Republic of)

    1996-11-01

    To evaluate, if possible, the radiographic features of tuberculous osteitis in the greater trochanter and ischium, and to determine the cause of the lesions. We reterospectively reviewed the plain radiographic findings of 14 ptients with histologically proven tuberculous osteitis involving the greater trochanter and ischium. In each case, the following were analyzed:morphology of bone destruction, including cortical erosion;periosteal reaction;presence or abscence of calcific shadows in adjacent soft tissue. On the basis of an analysis of radiographic features and correlation of the anatomy with adjacent structures we attempted to determine causes. Of the 14 cases evaluated, 12 showed varrious degrees of extrinsic erosion on the outer cortical bone of the greater trochanter and ischium ; in two cases, bone destruction was so severe that the radiographic features of advanced perforated osteomyelitis were simulated. In addition to findings of bone destruction, in these twelve cases, the presence of sequestrum or calcific shadows was seen in adjacent soft tissue. Tuberculous osteitis in the greater trochanter and ischium showed the characteristic findings of chronic extrinsic erosion. On the basis of these findings we can suggest that these lesions result from an extrinsic pathophysiologic cause such as adjacent bursitis.

  17. Search for greater stability in nuclear regulation

    International Nuclear Information System (INIS)

    Asselstine, J.K.

    1985-01-01

    The need for greater stability in nuclear regulation is discussed. Two possible approaches for dealing with the problems of new and rapidly changing regulatory requirements are discussed. The first approach relies on the more traditional licensing reform initiatives that have been considered off and on for the past decade. The second approach considers a new regulator philosophy aimed at the root causes of the proliferation of new safety requirements that have been imposed in recent years. For the past few years, the concepts of deregulation and regulatory reform have been in fashion in Washington, and the commercial nuclear power program has not remained unaffected. Many look to these concepts to provide greater stability in the regulatory program. The NRC, the nuclear industry and the administration have all been avidly pursuing regulatory reform initiatives, which take the form of both legislative and administrative proposals. Many of these proposals look to the future, and, if adopted, would have little impact on currently operating nuclear power plants or plants now under construction

  18. Molt performance and bone density of cortical, medullary, and cancellous bone in laying hens during feed restriction or alfalfa-based feed molt.

    Science.gov (United States)

    Kim, W K; Donalson, L M; Bloomfield, S A; Hogan, H A; Kubena, L F; Nisbet, D J; Ricke, S C

    2007-09-01

    A study was conducted to evaluate the effects of alfalfa-based molt diets on molting performance and bone qualities. A total of 36 Single Comb White Leghorn hens were used for the study. There were 6 treatments: pretrial control (PC), fully fed (FF), feed withdrawal (FW), 90% alfalfa:10% layer ration (A90), 80% alfalfa:20% layer ration (A80), and 70% alfalfa:30% layer ration (A70). For the PC treatment, hens were euthanized by CO(2) gas, and bones were collected before molt was initiated. At the end of the 9-d molt period, hens were euthanized, and femurs and tibias were collected to evaluate bone qualities by peripheral quantitative computed tomography, mechanical testing, and conventional ash weights. The hens fed alfalfa-based molt diets and FW stopped laying eggs within 5 d after molt started, and all hens in these groups had reduced ovary weights compared with those of the FF hens. In the FW and A90 groups, total femur volumetric bone mineral densities (vBMD) at the midshaft were significantly lower, but those of the A80 and A70 groups were not significantly different from the values for the PC and FF hens. In cortical bone density, the midshaft tibial vBMD were significantly higher for FF and A70 hens than for PC hens. The medullary bone densities at the midshaft femur or tibia of the FW, A90, A80, and A70 hens were reduced compared with those of the PC hens. Femur cancellous densities at the distal femur for the FW and A90 hens were significantly reduced compared with those of the PC and FF hens. The FW, A80, and A70 hens yielded significantly higher elastic moduli, and the A80 hens had higher ultimate stress compared with the PC hens, suggesting that the mechanical integrity of the midshaft bone was maintained even though the medullary vBMD was reduced. These results suggest that alfalfa-based molt diets exhibit molt performance similar to FW, that medullary and cancellous bones are labile bone compartments during molting, and that alfalfa-based molt diets

  19. Hospitals with greater diversities of physiologically complex procedures do not achieve greater surgical growth in a market with stable numbers of such procedures.

    Science.gov (United States)

    Dexter, Franklin; Epstein, Richard H; Lubarsky, David A

    2018-05-01

    Although having a large diversity of types of procedures has a substantial operational impact on the surgical suites of hospitals, the strategic importance is unknown. In the current study, we used longitudinal data for all hospitals and patient ages in the State of Florida to evaluate whether hospitals with greater diversity of types of physiologically complex major therapeutic procedures (PCMTP) also had greater rates of surgical growth. Observational cohort study. 1479 combinations of hospitals in the State of Florida and fiscal years, 2008-2015. The types of International Classification of Diseases, Ninth revision, Clinical Modification (ICD-9-CM) procedures studied were PCMT, defined as: a) major therapeutic procedure; b) >7 American Society of Anesthesiologists base units; and c) performed during a hospitalization with a Diagnosis Related Group with a mean length of stay ≥4.0days. The number of procedures of each type of PCMTP commonly performed at each hospital was calculated by taking 1/Herfindahl index (i.e., sum of the squares of the proportions of all procedures of each type of PCMTP). Over the 8 successive years studied, there was no change in the number of PCMTP being performed (Kendall's τ b =-0.014±0.017 [standard error], P=0.44; N=1479 hospital×years). Busier and larger hospitals commonly performed more types of PCMTP, respectively categorized based on performed PCMTP (τ=0.606±0.017, P<0.0001) or hospital beds (τ=0.524±0.017, P<0.0001). There was no association between greater diversity of types of PCMTP commonly performed and greater annual growth in numbers of PCMTP (τ=0.002±0.019, P=0.91; N=1295 hospital×years). Conclusions were the same with multiple sensitivity analyses. Post hoc, it was recognized that hospitals performing a greater diversity of PCMTP were more similar to the aggregate of other hospitals within the same health district (τ=0.550±0.017, P<0.0001). During a period with no overall growth in PCMTP, hospitals with

  20. Effect of Denosumab on Peripheral Compartmental Bone Density, Microarchitecture and Estimated Bone Strength in De Novo Kidney Transplant Recipients.

    Science.gov (United States)

    Bonani, Marco; Meyer, Ursina; Frey, Diana; Graf, Nicole; Bischoff-Ferrari, Heike A; Wüthrich, Rudolf P

    2016-01-01

    In a randomized controlled clinical trial in kidney transplant recipients (NCT01377467) we have recently shown that RANKL inhibition with denosumab significantly improved areal bone mineral density (aBMD) when given during the first year after transplantation. The effect of denosumab on skeletal microstructure and bone strength in kidney transplant recipients is not known. The purpose of the present bone microarchitecture ancillary study was to investigate high-resolution peripheral quantitative computed tomography (HRpQCT) data from the distal tibia and distal radius in 24 study patients that had been randomized to receive either two injections of denosumab 60 mg at baseline and after 6 months (n=10) or no treatment (n=14). Consistent with the full trial findings, denosumab reduced biomarkers of bone turnover, and significantly increased aBMD at the lumbar spine (median difference of 4.7%; 95% confidence interval [CI] 2.6 - 7.8; pBone quality as assessed by total and cortical volumetric bone mineral density (Tot. vBMD, Ct.vBMD) and cortical thickness (Ct.Th) increased significantly at the tibia, while changes at the radius were less pronounced. The trabecular volumetric BMD (Tb.vBMD), thickness (Tb. Th), separation (Tb.Sp) and number (Tb.N) and the cortical porosity (Ct.Po) at the tibia and the radius did not significantly change in both treatment groups. Micro-finite element analysis (µFEA) showed that bone stiffness increased significantly at the tibia (median difference 5.6%; 95% CI 1.8% - 9.2%; p=0.002) but not at the radius (median difference 2.9%, 95% CI -3.7% - 9.1%; p=0.369). Likewise, failure load increased significantly at the tibia (median difference 5.1%; 95% CI 2.1% - 8.1%; p=0.002) but not at the radius (median difference 2.4%, 95% CI -3.2% - 8.5%; p=0.336). These findings demonstrate that denosumab improves bone density and bone quality in first-year kidney transplant recipients at risk to develop osteoporosis. © 2016 The Author(s) Published by S

  1. The effects of once-weekly teriparatide on hip structure and biomechanical properties assessed by CT

    OpenAIRE

    Ito, M.; Oishi, R.; Fukunaga, M.; Sone, T.; Sugimoto, T.; Shiraki, M.; Nishizawa, Y.; Nakamura, T.

    2013-01-01

    Summary Once-weekly administration of 56.5 μg teriparatide improved cortical bone parameters and biomechanical parameters at the proximal femur by CT geometry analysis. Introduction The aim of this study was to evaluate the effects of weekly administration of teriparatide [human PTH (1–34)] on bone geometry, volumetric bone mineral density (vBMD), and parameters of bone strength at the proximal femur which were longitudinally investigated using computed tomography (CT). Methods The subjects w...

  2. Disruption of fibronectin matrix affects type IV collagen, fibrillin and laminin deposition into extracellular matrix of human trabecular meshwork (HTM) cells.

    Science.gov (United States)

    Filla, Mark S; Dimeo, Kaylee D; Tong, Tiegang; Peters, Donna M

    2017-12-01

    Fibronectin fibrils are a major component of the extracellular matrix (ECM) of the trabecular meshwork (TM). They are a key mediator of the formation of the ECM which controls aqueous humor outflow and contributes to the pathogenesis of glaucoma. The purpose of this work was to determine if a fibronectin-binding peptide called FUD, derived from the Streptococcus pyogenes Functional Upstream Domain of the F1 adhesin protein, could be used to control fibronectin fibrillogenesis and hence ECM formation under conditions where its expression was induced by treatment with the glucocorticoid dexamethasone. FUD was very effective at preventing fibronectin fibrillogenesis in the presence or absence of steroid treatment as well as the removal of existing fibronectin fibrils. Disruption of fibronectin fibrillogenesis by FUD also disrupted the incorporation of type IV collagen, laminin and fibrillin into the ECM. The effect of FUD on these other protein matrices, however, was found to be dependent upon the maturity of the ECM when FUD was added. FUD effectively disrupted the incorporation of these other proteins into matrices when added to newly confluent cells that were forming a nascent ECM. In contrast, FUD had no effect on these other protein matrices if the cell cultures already possessed a pre-formed, mature ECM. Our studies indicate that FUD can be used to control fibronectin fibrillogenesis and that these fibrils play a role in regulating the assembly of other ECM protein into matrices involving type IV collagen, laminin, and fibrillin within the TM. This suggests that under in vivo conditions, FUD would selectively disrupt fibronectin fibrils and de novo assembly of other proteins into the ECM. Finally, our studies suggest that targeting fibronectin fibril assembly may be a viable treatment for POAG as well as other glaucomas involving excessive or abnormal matrix deposition of the ECM. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. A Novel Mgp-Cre Knock-In Mouse Reveals an Anticalcification/Antistiffness Candidate Gene in the Trabecular Meshwork and Peripapillary Scleral Region.

    Science.gov (United States)

    Borrás, Teresa; Smith, Matthew H; Buie, LaKisha K

    2015-04-01

    Soft tissue calcification is a pathological condition. Matrix Gla (MGP) is a potent mineralization inhibitor secreted by cartilage chondrocytes and arteries' vascular smooth muscle cells. Mgp knock-out mice die at 6 weeks due to massive arterial calcification. Arterial calcification results in arterial stiffness and higher systolic blood pressure. Intriguingly, MGP was highly abundant in trabecular meshwork (TM). Because tissue stiffness is relevant to glaucoma, we investigated which additional eye tissues use Mgp's function using knock-in mice. An Mgp-Cre-recombinase coding sequence (Cre) knock-in mouse, containing Mgp DNA plus an internal ribosomal entry site (IRES)-Cre-cassette was generated by homologous recombination. Founders were crossed with Cre-mediated reporter mouse R26R-lacZ. Their offspring expresses lacZ where Mgp is transcribed. Eyes from MgpCre/+;R26RlacZ/+ (Mgp-lacZ knock-in) and controls, 1 to 8 months were assayed for β-gal enzyme histochemistry. As expected, Mgp-lacZ knock-in's TM was intensely blue. In addition, this mouse revealed high specific expression in the sclera, particularly in the peripapillary scleral region (ppSC). Ciliary muscle and sclera above the TM were also positive. Scleral staining was located immediately underneath the choroid (chondrocyte layer), began midsclera and was remarkably high in the ppSC. Cornea, iris, lens, ciliary body, and retina were negative. All mice exhibited similar staining patterns. All controls were negative. Matrix Gla's restricted expression to glaucoma-associated tissues from anterior and posterior segments suggests its involvement in the development of the disease. Matrix Gla's anticalcification/antistiffness properties in the vascular tissue, together with its high TM and ppCS expression, place this gene as a strong candidate for TM's softness and sclera's stiffness regulation in glaucoma.

  4. Short-term precision assessment of trabecular bone score and bone mineral density using dual-energy X-ray absorptiometry with different scan modes: an in vivo study

    Energy Technology Data Exchange (ETDEWEB)

    Bandirali, Michele; Poloni, Alessandro; Messina, Carmelo; Petrini, Marcello [Universita degli Studi di Milano, Scuola di Specializzazione in Radiodiagnostica, Milano (Italy); Sconfienza, Luca Maria; Sardanelli, Francesco [Unita di Radiologia, IRCCS Policlinico San Donato, San Donato Milanese (Italy); Universita degli Studi di Milano, Dipartimento di Scienze Biomediche per la Salute, San Donato Milanese (Italy); Papini, Giacomo Davide Edoardo; Di Leo, Giovanni [Unita di Radiologia, IRCCS Policlinico San Donato, San Donato Milanese (Italy); Ulivieri, Fabio Massimo [IRCCS Fondazione Ca' Granda Ospedale Maggiore Policlinico, Mineralometria Ossea Computerizzata e Ambulatorio Malattie Metabolismo Minerale e Osseo, Servizio di Medicina Nucleare, Milano (Italy)

    2015-07-15

    We estimated the in vivo reproducibility of trabecular bone score (TBS) from dual-energy X-ray absorptiometry (DXA) using different imaging modes to be compared to that of bone mineral density (BMD). We enrolled 30 patients for each imaging mode: fast-array, array, high definition. Each patient underwent two DXA examinations with in-between repositioning. BMD and TBS were obtained according to the International Society for Clinical Densitometry guidelines. The coefficient of variation (CoV) was calculated as the ratio between root mean square standard deviation and mean, percent least significant change (LSC) as 2.77 x CoV, reproducibility as the complement to 100 % LSC. Fast-array imaging mode resulted in 0.8 % CoV and 2.1 % LSC for BMD, 1.9 % and 5.3 % for TBS, respectively; array imaging mode resulted in 0.7 % and 2.0 % for BMD, 1.9 % and 5.2 %, for TBS; high-definition imaging mode resulted in 0.7 % and 2.0 %, for BMD; 2.0 % and 5.4 % for TBS, respectively. Reproducibility of TBS (95 %) was significantly lower than that of BMD (98 %) (p < 0.012). Difference in reproducibility among the imaging modes was not significant for either BMD or TBS (p = 0.942). While TBS reproducibility was significantly lower than that of BMD, differences among imaging modes were not significant for both TBS and BMD. (orig.)

  5. Sonography of greater trochanteric pain syndrome and the rarity of primary bursitis.

    Science.gov (United States)

    Long, Suzanne S; Surrey, David E; Nazarian, Levon N

    2013-11-01

    Greater trochanteric pain syndrome is a common condition with clinical features of pain and tenderness at the lateral aspect of the hip. Diagnosing the origin of greater trochanteric pain is important because the treatment varies depending on the cause. We hypothesized that sonographic evaluation of sources for greater trochanteric pain syndrome would show that bursitis was not the most commonly encountered abnormality. We performed a retrospective review of musculoskeletal sonographic examinations performed at our institution over a 6-year period for greater trochanteric pain syndrome; completed a tabulation of the sonographic findings; and assessed the prevalence of trochanteric bursitis, gluteal tendon abnormalities, iliotibial band abnormalities, or a combination of findings. Prevalence of abnormal findings, associations of bursitis, gluteal tendinosis, gluteal tendon tears, and iliotibial band abnormalities were calculated. The final study population consisted of 877 unique patients: 602 women, 275 men; average age, 54 years; and age range, 15-87 years). Of the 877 patients with greater trochanteric pain, 700 (79.8%) did not have bursitis on ultrasound. A minority of patients (177, 20.2%) had trochanteric bursitis. Of the 877 patients with greater trochanteric pain, 438 (49.9%) had gluteal tendinosis, four (0.5%) had gluteal tendon tears, and 250 (28.5%) had a thickened iliotibial band. The cause of greater trochanteric pain syndrome is usually some combination of pathology involving the gluteus medius and gluteus minimus tendons as well as the iliotibial band. Bursitis is present in only the minority of patients. These findings have implications for treatment of this common condition.