Increased fracture risk and low bone mineral density in patients with loeys-dietz syndrome.

PubMed

Tan, Eric W; Offoha, Roosevelt U; Oswald, Gretchen L; Skolasky, Richard L; Dewan, Ashvin K; Zhen, Gehua; Shapiro, Jay R; Dietz, Harry C; Cao, Xu; Sponseller, Paul D

2013-08-01

Loeys-Dietz syndrome is a recently recognized connective tissue disorder with widespread systemic involvement. Little is known about its skeletal phenotype. Our goal was to investigate the risk of fracture and incidence of low bone mineral density in patients with Loeys-Dietz syndrome. We performed a cross-sectional, descriptive, survey-based study with subsequent chart review from July 2011 to April 2012. Fifty-seven patients (26 men, 31 women) with Loeys-Dietz syndrome confirmed by genetic testing completed the survey (average age, 25.3 years; range, 0.9-79.6 years). There were a total of 51 fractures (33 patients): 35 fractures in the upper extremities, 14 in the lower extremities, and two in the spine. Fourteen patients (24.6%) reported two or more fractures. There was a 50% risk of fracture by age 14 years. The incidence of any fracture in this cohort was 3.86 per 100 person-years. Seventeen patients had dual-energy X-ray absorptiometry scans available for review, 11 (64.7%) of whom had at least one fracture. Thirteen included lumbar spine absorptiometry reports; eight (61.5%) indicated low or very low bone mineral density. In the left hip, ten of 14 participants (71.4%) had low or very low bone mineral density. In the left femoral neck, nine of 13 participants (69.2%) had low or very low bone mineral density. The lowest Z- and T-scores were not associated with an increased number of fractures. Patients with Loeys-Dietz syndrome have a high risk of fracture and a high incidence of low bone mineral density. Copyright © 2013 Wiley Periodicals, Inc.

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.

PubMed

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

2007-10-01

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 premenopausal (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 × 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.

Testing the system detection unit for measuring solid minerals bulk density

NASA Astrophysics Data System (ADS)

Voytyuk, I. N.; Kopteva, A. V.

2017-10-01

The paper provides a brief description of the system for measuring flux per volume of solid minerals via example of mineral coal. The paper discloses the operational principle of the detection unit. The paper provides full description of testing methodology, as well as practical implementation of the detection unit testing. This paper describes the removal of two data arrays via the channel of scattered anddirect radiation for the detection units of two generations. This paper describes Matlab software to determine the statistical characteristics of the studied objects. The mean value of pulses per cycles, and pulse counting inaccuracy relatively the mean value were determined for the calculation of the stability account of the detection units.

Relation between body composition and bone mineral density in young undregraduate students with different nutritional status

PubMed Central

Rodrigues, Edil de Albuquerque; dos Santos, Marcos André Moura; da Silva, Amanda Tabosa Pereira; Farah, Breno Quintella; Costa, Manoel da Cunha; Campos, Florisbela de Arruda Camara e Siqueira; Falcão, Ana Patrícia Siqueira Tavares

2016-01-01

ABSTRACT Objective To investigate the relationship between total and segmental body fat, bone mineral density and bone mineral content in undergraduate students stratified according to nutritional status. Methods The study included 45 male undergraduate students aged between 20 and 30 years. Total and segmental body composition, bone mineral density and bone mineral content assessments were performed using dual energy X-ray absorptiometry. Subjects were allocated into three groups (eutrophic, overweight and obese). Results With the exception of upper limb bone mineral content, significantly higher (p<0.05) mean bone mineral density, bone mineral content, and relative body fat values were documented in the obese group. Total body and segmental relative body fat (lower limbs and trunk) were positively correlated (p<0.05) with bone mineral density in the overweight group. Upper limb fat was negatively correlated (p<0.05) with bone mineral content in the normal and eutrophic groups. Conclusion Total body and segmental body fat were correlated with bone mineral density and bone mineral content in male undergraduate students, particularly in overweight individuals. PMID:27074228

Biomedical Results of ISS Expeditions 1-12

NASA Technical Reports Server (NTRS)

Fogarty, Jennifer; Sams, Clarence F.

2007-01-01

A viewgraph presentation on biomedical data from International Space Station (ISS) Expeditions 1-12 is shown. The topics include: 1) ISS Expeditions 1-12; 2) Biomedical Data; 3) Physiological Assessments; 4) Bone Mineral Density; 5) Bone Mineral Density Recovery; 6) Orthostatic Tolerance; 7) Postural Stability Set of Sensory Organ Test 6; 8) Performance Assessment; 9) Aerobic Capacity of the Astronaut Corps; 10) Pre-flight Aerobic Fitness of ISS Astronauts; 11) In-flight and Post-flight Aerobic Capacity of the Astronaut Corps; and 12) ISS Functional Fitness Expeditions 1-12.

Vitamin D level after allogeneic hematopoietic stem cell transplant.

PubMed

Sproat, Lisa; Bolwell, Brian; Rybicki, Lisa; Dean, Robert; Sobecks, Ronald; Pohlman, Brad; Andresen, Steven; Sweetenham, John; Copelan, Edward; Kalaycio, Matt

2011-07-01

Vitamin D (VD) deficiency can cause osteomalacia, bone pain, muscle weakness, fatigue, and increased risk of fracture, and may precipitate or exacerbate osteopenia and osteoporosis. Patients receiving treatment for acute myeloid leukemia (AML) or acute lymphoblastic leukemia (ALL) may have limited exposure to sunlight and often experience gastrointestinal side effects that may decrease their ability to maintain an adequate VD level. We hypothesized that patients with AML and ALL would have a low VD level after allogeneic hematopoietic cell transplant (HCT), and that these patients would have a high incidence of osteoporosis/osteopenia. We therefore studied the incidence of low VD level and low bone mineral density after HCT. Of 289 patients with AML or ALL undergoing HCT between January 1, 2000, and January 31, 2009, at the Cleveland Clinic, 58 (20.1%) patients had VD testing after HCT. Of these, 52 (89.7%) patients had a low VD level, and 6 (10.3%) had a normal level. Most patients with VD testing had graft-versus-host disease (GVHD) and were taking corticosteroids (94.8% and 98.3%, respectively). Of the 49 patients with VD testing who also had bone mineral density testing, 65% had abnormal (low bone density) results. Only 21% of patients with VD testing were taking VD supplements prior to testing, and 65% had an elevated parathyroid hormone level. We found that most patients did not have VD testing after HCT, but those that did were very likely to have a low level and have low bone mineral density. Those with a low VD level were likely to have received corticosteroids, have GVHD, and have an elevated parathyroid hormone (PTH) level. Given the potential morbidity of low VD level, VD deficiency should be considered after HCT. Prospective study of VD level and its impact on morbidity and mortality after HCT is warranted. 2011 American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.

The peripheral quantitative computed tomographic and densitometric analysis of skeletal tissue in male Wistar rats after chromium sulfate treatment.

PubMed

Bieńko, Marek; Radzki, Radosław Piotr; Wolski, Dariusz

2017-09-21

This study evaluates the effects of three different doses of chromium sulphate on bone density and the tomographic parameters of skeletal tissue of rats. The experiment was performed on 40 male Wistar rats which received, by gavage, during 90 days, a chromium sulphate in either a daily dose of 400, 600 or 800 µg/kg BW. At the end of experiment, the rats were scanned using the densitometry method (DXA) to determine the bone mineral density, bone mineral content of total skeleton and vertebral column (L2-L4) and parameters of body composition (Lean Mass and Fat Mass). The isolated femora were scanned using peripheral a quantitative computed tomography method (pQCT) for a separate analysis of the trabecular and cortical bone tissue. The ultimate strength, work to ultimate and the Young modulus of femora was also investigated by the three-point bending test. The negative impact of chromium was observed in relation to bone tissue. All doses significantly decreased total skeleton density and mineral content, and also had impact upon the isolated femora and vertebral column. Trabecular volumetric bone mineral density and trabecular bone mineral content measured by pQCT in distal femur metaphysis were significantly lower in the experimental groups than in the control. Higher doses of chromium also significantly decreased values of ultimate strength and Young modulus in the investigated femora. The results of the experiment demonstrate that chromium sulphate is dose dependent, and exerts a disadvantageous effect on the skeleton, as it decreases bone density and resistance.

Phytate (myo-inositol hexaphosphate) and risk factors for osteoporosis.

PubMed

López-González, A A; Grases, F; Roca, P; Mari, B; Vicente-Herrero, M T; Costa-Bauzá, A

2008-12-01

Several risk factors seem to play a role in the development of osteoporosis. Phytate is a naturally occurring compound that is ingested in significant amounts by those with diets rich in whole grains. The aim of this study was to evaluate phytate consumption as a risk factor in osteoporosis. In a first group of 1,473 volunteer subjects, bone mineral density was determined by means of dual radiological absorptiometry in the calcaneus. In a second group of 433 subjects (used for validation of results obtained for the first group), bone mineral density was determined in the lumbar column and the neck of the femur. Subjects were individually interviewed about selected osteoporosis risk factors. Dietary information related to phytate consumption was acquired by questionnaires conducted on two different occasions, the second between 2 and 3 months after performing the first one. One-way analysis of variance or Student's t test was used to determine statistical differences between groups. Bone mineral density increased with increasing phytate consumption. Multivariate linear regression analysis indicated that body weight and low phytate consumption were the risk factors with greatest influence on bone mineral density. Phytate consumption had a protective effect against osteoporosis, suggesting that low phytate consumption should be considered an osteoporosis risk factor.

Effects of exercise on bone mineral density in calcium-replete postmenopausal women with and without hormone replacement therapy.

PubMed

Going, Scott; Lohman, Timothy; Houtkooper, Linda; Metcalfe, Lauve; Flint-Wagner, Hilary; Blew, Robert; Stanford, Vanessa; Cussler, Ellen; Martin, Jane; Teixeira, Pedro; Harris, Margaret; Milliken, Laura; Figueroa-Galvez, Arturo; Weber, Judith

2003-08-01

Osteoporosis is a major public health concern. The combination of exercise, hormone replacement therapy, and calcium supplementation may have added benefits for improving bone mineral density compared to a single intervention. To test this notion, 320 healthy, non-smoking postmenopausal women, who did or did not use hormone replacement therapy (HRT), were randomized within groups to exercise or no exercise and followed for 12 months. All women received 800 mg calcium citrate supplements daily. Women who exercised performed supervised aerobic, weight-bearing and weight-lifting exercise, three times per week in community-based exercise facilities. Regional bone mineral density (BMD) was assessed by dual energy X-ray absorptiometry. Women who used HRT, calcium, and exercised increased femoral neck, trochanteric and lumbar spine bone mineral density by approximately 1-2%. Trochanteric BMD was also significantly increased by approximately 1.0% in women who exercised and used calcium without HRT compared to a negligible change in women who used HRT and did not exercise. The results demonstrate that regional BMD can be improved with aerobic, weight-bearing activity combined with weight lifting at clinically relevant sites in postmenopausal women. The response was significant at more sites in women who used HRT, suggesting a greater benefit with hormone replacement and exercise compared to HRT alone.

Interrelationships Between Morphometric, Densitometric, and Mechanical Properties of Teeth in 5-Month-Old Polish Merino Sheep.

PubMed

Tatara, Marcin R; Szabelska, Anna; Krupski, Witold; Tymczyna, Barbara; Łuszczewska-Sierakowska, Iwona; Bieniaś, Jarosław; Ostapiuk, Monika

2018-06-01

Interrelationships between morphological, densitometric, and mechanical properties of deciduous mandibular teeth (incisors, canine, second premolar) were investigated. To perform morphometric, densitometric, and mechanical analyses, teeth were obtained from 5-month-old sheep. Measurements of mean volumetric tooth mineral density and total tooth volume were performed using quantitative computed tomography. Microcomputed tomography was used to measure total enamel volume, volumetric enamel mineral density, total dentin volume, and volumetric dentin mineral density. Maximum elastic strength and ultimate force of teeth were determined using 3-point bending and compression tests. Pearson correlation coefficients were determined between all investigated variables. Mutual dependence was observed between morphological and mechanical properties of the investigated teeth. The highest number of positive correlations of the investigated parameters was stated in first incisor indicating its superior predictive value of tooth quality and masticatory organ function in sheep. Positive correlations of the volumetric dentin mineral density in second premolar with final body weight may indicate predictive value of this parameter in relation with growth rate in sheep. Evaluation of deciduous tooth properties may prove helpful for breeding selection and further reproduction of sheep possessing favorable traits of teeth and better masticatory organ function, leading to improved performance and economic efficiency of the flock.

Low bone mineral density in ambulatory persons with cerebral palsy? A systematic review.

PubMed

Mus-Peters, Cindy T R; Huisstede, Bionka M A; Noten, Suzie; Hitters, Minou W M G C; van der Slot, Wilma M A; van den Berg-Emons, Rita J G

2018-05-22

Non-ambulatory persons with cerebral palsy are prone to low bone mineral density. In ambulatory persons with cerebral palsy, bone mineral density deficits are expected to be small or absent, but a consensus conclusion is lacking. In this systematic review bone mineral density in ambulatory persons with cerebral palsy (Gross Motor Function Classification Scales I-III) was studied. Medline, Embase, and Web of Science were searched. According to international guidelines, low bone mineral density was defined as Z-score ≤ -2.0. In addition, we focused on Z-score ≤ -1.0 because this may indicate a tendency towards low bone mineral density. We included 16 studies, comprising 465 patients aged 1-65 years. Moderate and conflicting evidence for low bone mineral density (Z-score ≤ -2.0) was found for several body parts (total proximal femur, total body, distal femur, lumbar spine) in children with Gross Motor Function Classification Scales II and III. We found no evidence for low bone mineral density in children with Gross Motor Function Classification Scale I or adults, although there was a tendency towards low bone mineral density (Z-score ≤ -1.0) for several body parts. Although more high-quality research is needed, results indicate that deficits in bone mineral density are not restricted to non-ambulatory people with cerebral palsy. Implications for Rehabilitation Although more high-quality research is needed, including adults and fracture risk assessment, the current study indicates that deficits in bone mineral density are not restricted to non-ambulatory people with CP. Health care professionals should be aware that optimal nutrition, supplements on indication, and an active lifestyle, preferably with weight-bearing activities, are important in ambulatory people with CP, also from a bone quality point-of-view. If indicated, medication and fall prevention training should be prescribed.

Bone Mineral 31P and Matrix-Bound Water Densities Measured by Solid-State 1H and 31P MRI

PubMed Central

Seifert, Alan C.; Li, Cheng; Rajapakse, Chamith S.; Bashoor- Zadeh, Mahdieh; Bhagat, Yusuf A.; Wright, Alexander C.; Zemel, Babette S.; Zavaliangos, Antonios; Wehrli, Felix W.

2014-01-01

Bone is a composite material consisting of mineral and hydrated collagen fractions. MRI of bone is challenging due to extremely short transverse relaxation times, but solid-state imaging sequences exist that can acquire the short-lived signal from bone tissue. Previous work to quantify bone density via MRI used powerful experimental scanners. This work seeks to establish the feasibility of MRI-based measurement on clinical scanners of bone mineral and collagen-bound water densities, the latter as a surrogate of matrix density, and to examine the associations of these parameters with porosity and donors’ age. Mineral and matrix-bound water images of reference phantoms and cortical bone from 16 human donors, ages 27-97 years, were acquired by zero-echo-time 31P and 1H MRI on whole body 7T and 3T scanners, respectively. Images were corrected for relaxation and RF inhomogeneity to obtain density maps. Cortical porosity was measured by micro-CT, and apparent mineral density by pQCT. MRI-derived densities were compared to x-ray-based measurements by least-squares regression. Mean bone mineral 31P density was 6.74±1.22 mol/L (corresponding to 1129±204 mg/cc mineral), and mean bound water 1H density was 31.3±4.2 mol/L (corresponding to 28.3±3.7 %v/v). Both 31P and bound water (BW) densities were correlated negatively with porosity (31P: R2 = 0.32, p < 0.005; BW: R2 = 0.63, p < 0.0005) and age (31P: R2 = 0.39, p < 0.05; BW: R2 = 0.70, p < 0.0001), and positively with pQCT density (31P: R2 = 0.46, p < 0.05; BW: R2 = 0.50, p < 0.005). In contrast, the bone mineralization ratio (expressed here as the ratio of 31P density to bound water density), which is proportional to true bone mineralization, was found to be uncorrelated with porosity, age, or pQCT density. This work establishes the feasibility of image-based quantification of bone mineral and bound water densities using clinical hardware. PMID:24846186

Intestinal Calcium Absorption among Hypercalciuric Patients with or without Calcium Kidney Stones.

PubMed

Vezzoli, Giuseppe; Macrina, Lorenza; Rubinacci, Alessandro; Spotti, Donatella; Arcidiacono, Teresa

2016-08-08

Idiopathic hypercalciuria is a frequent defect in calcium kidney stone formers that is associated with high intestinal calcium absorption and osteopenia. Characteristics distinguishing hypercalciuric stone formers from hypercalciuric patients without kidney stone history (HNSFs) are unknown and were explored in our study. We compared 172 hypercalciuric stone formers with 36 HNSFs retrospectively selected from patients referred to outpatient clinics of the San Raffaele Hospital in Milan from 1998 to 2003. Calcium metabolism and lumbar bone mineral density were analyzed in these patients. A strontium oral load test was performed: strontium was measured in 240-minute urine and serum 30, 60, and 240 minutes after strontium ingestion; serum strontium concentration-time curve and renal strontium clearance were evaluated to estimate absorption and excretion of divalent cations. Serum strontium concentration-time curve (P<0.001) and strontium clearance (4.9±1.3 versus 3.5±2.7 ml/min; P<0.001) were higher in hypercalciuric stone formers than HNSFs, respectively. The serum strontium-time curve was also higher in hypercalciuric stone formers with low bone mineral density (n=42) than in hypercalciuric stone formers with normal bone mineral density (n=130; P=0.03) and HNSFs with low (n=22; P=0.01) or normal bone mineral density (n=14; P=0.02). Strontium clearance was greater in hypercalciuric stone formers with normal bone mineral density (5.3±3.4 ml/min) than in hypercalciuric stone formers and HNSFs with low bone mineral density (3.6±2.5 and 3.1±2.5 ml/min, respectively; P=0.03). Multivariate regression analyses displayed that strontium absorption at 30 minutes was positively associated calcium excretion (P=0.03) and negatively associated with lumbar bone mineral density z score (P=0.001) in hypercalciuric stone formers; furthermore, hypercalciuric patients in the highest quartile of strontium absorption had increased stone production risk (odds ratio, 5.06; 95% confidence interval, 1.2 to 20.9; P=0.03). High calcium absorption in duodenum and jejunum may expose hypercalciuric patients to the risk of stones because of increased postprandial calcium concentrations in urine and tubular fluid. High calcium absorption may identify patients at risk of bone loss among stone formers. Copyright © 2016 by the American Society of Nephrology.

Association of Thr420Lys polymorphism in DBP gene with fat-soluble vitamins and low radial bone mineral density in postmenopausal Thai women.

PubMed

Chupeerach, Chaowanee; Tungtrongchitr, Anchalee; Phonrat, Benjaluck; Schweigert, Florian J; Tungtrongchitr, Rungsunn; Preutthipan, Sangchai

2012-02-01

To investigate the genetic markers for osteoporosis bone mineral density by the genotyping of rs7041, rs4588 and rs1352845 in the DBP gene with either bone mineral density or serum 25-hydroxycholecalciferol, retinol and α-tocopherol, among 365 postmenopausal Thai women. The DBP genotypes were analyzed by a PCR restriction fragment-length polymorphism method. Serum 25-hydroxycholecalciferol was assessed using a commercial chemiluminescent immunoassay. Serum retinol and α-tocopherol were measured by reverse-phase high-performance liquid chromatography. After adjustment for age >50 years, elder Thai subjects with low BMI (≤25 kg/m(2)) and carrying the rs4588 CC genotype had a higher risk of radial bone mineral density osteoporosis (odds ratio: 6.29; p = 0.048). The rs1352845 genotype also had a statistical association with total hip bone mineral density; however, it disappeared after adjustment for age and BMI. No association was found in fat-soluble vitamins with bone mineral density. DBP genotypes may influence the osteoporosis bone mineral density in postmenopausal Thai women.

Metacarpal head biomechanics: a comparative backscattered electron image analysis of trabecular bone mineral density in Pan troglodytes, Pongo pygmaeus, and Homo sapiens.

PubMed

Zeininger, Angel; Richmond, Brian G; Hartman, Gideon

2011-06-01

Great apes and humans use their hands in fundamentally different ways, but little is known about joint biomechanics and internal bone variation. This study examines the distribution of mineral density in the third metacarpal heads in three hominoid species that differ in their habitual joint postures and loading histories. We test the hypothesis that micro-architectural properties relating to bone mineral density reflect habitual joint use. The third metacarpal heads of Pan troglodytes, Pongo pygmaeus, and Homo sapiens were sectioned in a sagittal plane and imaged using backscattered electron microscopy (BSE-SEM). For each individual, 72 areas of subarticular cortical (subchondral) and trabecular bone were sampled from within 12 consecutive regions of the BSE-SEM images. In each area, gray levels (representing relative mineralization density) were quantified. Results show that chimpanzee, orangutan, and human metacarpal III heads have different gray level distributions. Weighted mean gray levels (WMGLs) in the chimpanzee showed a distinct pattern in which the 'knuckle-walking' regions (dorsal) and 'climbing' regions (palmar) are less mineralized, interpreted to reflect elevated remodeling rates, than the distal regions. Pongo pygmaeus exhibited the lowest WMGLs in the distal region, suggesting elevated remodeling rates in this region, which is loaded during hook grip hand postures associated with suspension and climbing. Differences among regions within metacarpal heads of the chimpanzee and orangutan specimens are significant (Kruskal-Wallis, p < 0.001). In humans, whose hands are used for manipulation as opposed to locomotion, mineralization density is much more uniform throughout the metacarpal head. WMGLs were significantly (p < 0.05) lower in subchondral compared to trabecular regions in all samples except humans. This micro-architectural approach offers a means of investigating joint loading patterns in primates and shows significant differences in metacarpal joint biomechanics among great apes and humans. Copyright © 2011 Elsevier Ltd. All rights reserved.

Comparison of instruments for dual-energy X-ray bone mineral densitometry.

PubMed

Vainio, P; Ahonen, E; Leinonen, K; Sievänen, H; Koski, E

1992-04-01

While bone mineral densitometry has become a common laboratory test, it is important to pay attention to the compatibility of the results from different instruments. In this study results from three commercially available bone densitometers are compared using both patient and phantom studies. Overall correlation between instruments was good but there were systematic discrepancies in the results. The three instruments provided bone mineral density (BMD) values that differed by as much as 13.5% due to differences as large as 6% in bone mineral content and as large as 7% in bone area. Thus, the BMD values obtained from different manufacturers' instruments are not directly comparable.

Assessment and clinical management of bone disease in adults with eating disorders: a review.

PubMed

Drabkin, Anne; Rothman, Micol S; Wassenaar, Elizabeth; Mascolo, Margherita; Mehler, Philip S

2017-01-01

To review current medical literature regarding the causes and clinical management options for low bone mineral density (BMD) in adult patients with eating disorders. Low bone mineral density is a common complication of eating disorders with potentially lifelong debilitating consequences. Definitive, rigorous guidelines for screening, prevention and management are lacking. This article intends to provide a review of the literature to date and current options for prevention and treatment. Current, peer-reviewed literature was reviewed, interpreted and summarized. Any patient with lower than average BMD should weight restore and in premenopausal females, spontaneous menses should resume. Adequate vitamin D and calcium supplementation is important. Weight-bearing exercise should be avoided unless cautiously monitored by a treatment team in the setting of weight restoration. If a patient has a Z-score less than expected for age with a high fracture risk or likelihood of ongoing BMD loss, physiologic transdermal estrogen plus oral progesterone, bisphosphonates (alendronate or risedronate) or teriparatide could be considered. Other agents, such as denosumab and testosterone in men, have not been tested in eating-disordered populations and should only be trialed on an empiric basis if there is a high clinical concern for fractures or worsening bone mineral density. A rigorous peer-based approach to establish guidelines for evaluation and management of low bone mineral density is needed in this neglected subspecialty of eating disorders.

The relationships of irisin with bone mineral density and body composition in PCOS patients.

PubMed

Gao, Shanshan; Cheng, Yan; Zhao, Lingling; Chen, Yuxin; Liu, Yu

2016-05-01

Our study aims to assay the irisin level and investigate the relationships of irisin level with body mass index (BMI), body composition and bone metabolism in the polycystic ovary syndrome (PCOS) and control women. Fifty two PCOS and 39 control women were recruited. Serum sex hormone, fasting insulin and C-peptide were tested. Fasting serum irisin and adiponectin were measured with enzyme-linked immunosorbent assay. Body composition and bone mineral density were assayed by dual energy X-ray absorptiometry. Polycystic ovary syndrome women showed different body compositions compared with controls. Serum irisin level of PCOS did not show significant difference compared with controls although it was decreased. The level of adiponectin in PCOS patients was significantly reduced. BMI had no correlation with irisin level. It indicated a positive correlation between serum irisin levels and bone mineral density in the control group and a negative correlation in the PCOS group after BMI and age adjusted. Furthermore, total lean mass has a significant effect on irisin concentration in the PCOS group. There are no correlations between adiponection and body compositions and bone mineral density in both groups. The abnormal body composition in PCOS may contribute to the circulation irisin. The crosstalk of irisin in different organs was found and may be related to disease development in PCOS. Copyright © 2015 John Wiley & Sons, Ltd.

SGC Tests for Influence of Material Composition on Compaction Characteristic of Asphalt Mixtures

PubMed Central

Chen, Qun

2013-01-01

Compaction characteristic of the surface layer asphalt mixture (13-type gradation mixture) was studied using Superpave gyratory compactor (SGC) simulative compaction tests. Based on analysis of densification curve of gyratory compaction, influence rules of the contents of mineral aggregates of all sizes and asphalt on compaction characteristic of asphalt mixtures were obtained. SGC Tests show that, for the mixture with a bigger content of asphalt, its density increases faster, that there is an optimal amount of fine aggregates for optimal compaction and that an appropriate amount of mineral powder will improve workability of mixtures, but overmuch mineral powder will make mixtures dry and hard. Conclusions based on SGC tests can provide basis for how to adjust material composition for improving compaction performance of asphalt mixtures, and for the designed asphalt mixture, its compaction performance can be predicted through these conclusions, which also contributes to the choice of compaction schemes. PMID:23818830

SGC tests for influence of material composition on compaction characteristic of asphalt mixtures.

PubMed

Chen, Qun; Li, Yuzhi

2013-01-01

Compaction characteristic of the surface layer asphalt mixture (13-type gradation mixture) was studied using Superpave gyratory compactor (SGC) simulative compaction tests. Based on analysis of densification curve of gyratory compaction, influence rules of the contents of mineral aggregates of all sizes and asphalt on compaction characteristic of asphalt mixtures were obtained. SGC Tests show that, for the mixture with a bigger content of asphalt, its density increases faster, that there is an optimal amount of fine aggregates for optimal compaction and that an appropriate amount of mineral powder will improve workability of mixtures, but overmuch mineral powder will make mixtures dry and hard. Conclusions based on SGC tests can provide basis for how to adjust material composition for improving compaction performance of asphalt mixtures, and for the designed asphalt mixture, its compaction performance can be predicted through these conclusions, which also contributes to the choice of compaction schemes.

Validation of cortical bone mineral density distribution using micro-computed tomography.

PubMed

Mashiatulla, Maleeha; Ross, Ryan D; Sumner, D Rick

2017-06-01

Changes in the bone mineral density distribution (BMDD), due to disease or drugs, can alter whole bone mechanical properties such as strength, stiffness and toughness. The methods currently available for assessing BMDD are destructive and two-dimensional. Micro-computed tomography (μCT) has been used extensively to quantify the three-dimensional geometry of bone and to measure the mean degree of mineralization, commonly called the tissue mineral density (TMD). The TMD measurement has been validated to ash density; however parameters describing the frequency distribution of TMD have not yet been validated. In the current study we tested the ability of μCT to estimate six BMDD parameters: mean, heterogeneity (assessed by the full-width-at-half-maximum (FWHM) and the coefficient of variation (CoV)), the upper and lower 5% cutoffs of the frequency distribution, and peak mineralization) in rat sized femoral cortical bone samples. We used backscatter scanning electron microscopy (bSEM) as the standard. Aluminum and hydroxyapatite phantoms were used to identify optimal scanner settings (70kVp, and 57μA, with a 1500ms integration time). When using hydroxyapatite samples that spanned a broad range of mineralization levels, high correlations were found between μCT and bSEM for all BMDD parameters (R 2 ≥0.92, p<0.010). When using cortical bone samples from rats and various species machined to mimic rat cortical bone geometry, significant correlations between μCT and bSEM were found for mean mineralization (R 2 =0.65, p<0.001), peak mineralization (R 2 =0.61, p<0.001) the lower 5% cutoff (R 2 =0.62, p<0.001) and the upper 5% cutoff (R 2 =0.33, p=0.021), but not for heterogeneity, measured by FWHM (R 2 =0.05, p=0.412) and CoV (R 2 =0.04, p=0.469). Thus, while mean mineralization and most parameters used to characterize the BMDD can be assessed with μCT in rat sized cortical bone samples, caution should be used when reporting the heterogeneity. Copyright © 2017 Elsevier Inc. All rights reserved.

Micro-Computed Tomography Assessment of Fracture Healing: Relationships among Callus Structure, Composition, and Mechanical Function

PubMed Central

Morgan, Elise F.; Mason, Zachary D.; Chien, Karen B.; Pfeiffer, Anthony J.; Barnes, George L.; Einhorn, Thomas A.; Gerstenfeld, Louis C.

2009-01-01

Non-invasive characterization of fracture callus structure and composition may facilitate development of surrogate measures of the regain of mechanical function. As such, quantitative computed tomography- (CT-) based analyses of fracture calluses could enable more reliable clinical assessments of bone healing. Although previous studies have used CT to quantify and predict fracture healing, it is unclear which of the many CT-derived metrics of callus structure and composition are the most predictive of callus mechanical properties. The goal of this study was to identify the changes in fracture callus structure and composition that occur over time and that are most closely related to the regain of mechanical function. Micro-computed tomography (μCT) imaging and torsion testing were performed on murine fracture calluses (n=188) at multiple post-fracture timepoints and under different experimental conditions that alter fracture healing. Total callus volume (TV), mineralized callus volume (BV), callus mineralized volume fraction (BV/TV), bone mineral content (BMC), tissue mineral density (TMD), standard deviation of mineral density (σTMD), effective polar moment of inertia (Jeff), torsional strength, and torsional rigidity were quantified. Multivariate statistical analyses, including multivariate analysis of variance, principal components analysis, and stepwise regression were used to identify differences in callus structure and composition among experimental groups and to determine which of the μCT outcome measures were the strongest predictors of mechanical properties. Although calluses varied greatly in the absolute and relative amounts of mineralized tissue (BV, BMC, and BV/TV), differences among timepoints were most strongly associated with changes in tissue mineral density. Torsional strength and rigidity were dependent on mineral density as well as the amount of mineralized tissue: TMD, BV, and σTMD explained 62% of the variation in torsional strength (p<0.001); and TMD, BMC, BV/TV, and σTMD explained 70% of the variation in torsional rigidity (p<0.001). These results indicate that fracture callus mechanical properties can be predicted by several μCT-derived measures of callus structure and composition. These findings form the basis for developing non-invasive assessments of fracture healing and for identifying biological and biomechanical mechanisms that lead to impaired or enhanced healing. PMID:19013264

Local variations in bone mineral density: a comparison of OCT versus x-ray micro-CT

NASA Astrophysics Data System (ADS)

Ugryumova, Nadya; Stevens-Smith, Jenna; Scutt, Andrew; Matcher, Stephen J.

2008-02-01

We describe variations in the degree of mineralisation within the subchondral bone plate of the equine metacarpophalangeal joint. A comparison of Optical Coherence Tomography, Micro CT, and SEM techniques was performed. These data are compared between sites on a healthy sample and at points on an osteoarthritically degenerated sample. No significant correlation was found between the optical scattering coefficient and the micro-CT derived BMD for comparisons between different sites on the bone surface. Also OCT demonstrated a larger regional variation in scattering coefficient than did micro CT for bone mineral density. This suggests that the optical scattering coefficient of bone is not related solely to the volume-density of calcium-phosphate. Patches of lower optical scattering coefficient were found in the bone structure that was related to the osteoarthritic lesion area on the overlying cartilage. Areas of microcracking, as revealed by both SEM and micro CT produced distinctive granularity in the OCT images. In further experiments, OCT was compared with micro CT and mechanical strength testing (3-point bending) in a small animal model of cardiovascular disease (cholesterol overload in mice). In the cardiovascular diseased mice, micro-CT of the trabecular bone did not demonstrate a significant change in trabecular bone mineral density before and after administration of the high cholesterol diet. However mechanical testing demonstrated a decrease in mechanical strength and OCT demonstrated a corresponding statistically significant decrease in optical scattering of the bone.

Risk factors for low bone mineral density in children and adolescents with inflammatory bowel disease.

PubMed

Lopes, Letícia Helena Caldas; Sdepanian, Vera Lucia; Szejnfeld, Vera Lúcia; de Morais, Mauro Batista; Fagundes-Neto, Ulysses

2008-10-01

To evaluate bone mineral density of the lumbar spine in children and adolescents with inflammatory bowel disease, and to identify the clinical risk factors associated with low bone mineral density. Bone mineral density of the lumbar spine was evaluated using dual-energy X-ray absorptiometry (DXA) in 40 patients with inflammatory bowel disease. Patients were 11.8 (SD = 4.1) years old and most of them were male (52.5%). Multiple linear regression analysis was performed to identify potential associations between bone mineral density Z-score and age, height-for-age Z-score, BMI Z-score, cumulative corticosteroid dose in milligrams and in milligrams per kilogram, disease duration, number of relapses, and calcium intake according to the dietary reference intake. Low bone mineral density (Z-score bellow -2) was observed in 25% of patients. Patients with Crohn's disease and ulcerative colitis had equivalent prevalence of low bone mineral density. Multiple linear regression models demonstrated that height-for-age Z-score, BMI Z-score, and cumulative corticosteroid dose in mg had independent effects on BMD, respectively, beta = 0.492 (P = 0.000), beta = 0.460 (P = 0.001), beta = - 0.014 (P = 0.000), and these effects remained significant after adjustments for disease duration, respectively, beta = 0.489 (P = 0.013), beta = 0.467 (P = 0.001), and beta = - 0.005 (P = 0.015). The model accounted for 54.6% of the variability of the BMD Z-score (adjusted R2 = 0.546). The prevalence of low bone mineral density in children and adolescents with inflammatory bowel disease is considerably high and independent risk factors associated with bone mineral density are corticosteroid cumulative dose in milligrams, height-for-age Z-score, and BMI Z-score.

Reliability of analysis of the bone mineral density of the second and fifth metatarsals using dual-energy x-ray absorptiometry (DXA).

PubMed

Pritchard, N Stewart; Smoliga, James M; Nguyen, Anh-Dung; Branscomb, Micah C; Sinacore, David R; Taylor, Jeffrey B; Ford, Kevin R

2017-01-01

Metatarsal fractures, especially of the fifth metatarsal, are common injuries of the foot in a young athletic population, but the risk factors for this injury are not well understood. Dual-energy x-ray absorptiometry (DXA) provides reliable measures of regional bone mineral density to predict fracture risk in the hip and lumbar spine. Recently, sub-regional metatarsal reliability was established in fresh cadaveric specimens and associated with ultimate fracture force. The purpose of this study was to assess the reliability of DXA bone mineral density measurements of sub-regions of the second and fifth metatarsals in a young, active population. Thirty two recreationally active individuals participated in the study, and the bone density of the second (2MT) and fifth (5MT) metatarsals of each subject was measured using a Hologic QDR x-ray bone densitometer. Scans were analyzed separately by two raters, and regional bone mineral density, bone mineral content, and area measurements were calculated for the proximal, shaft, and distal regions of the bone. Intra-rater, inter-rater, and scan-rescan reliability were then determined for each region. Proximal and shaft bone mineral density measurements of the second and fifth metatarsal were reliable. ICC's were variable across regions and metatarsals, with the distal region being the poorest. Bone mineral density measurements of the metatarsals may be a better indicator of fracture risk of the metatarsals than whole body measurements. A reliable method for measuring the regional bone mineral densities of the metatarsals was found. However, inter-rater reliability and scan-rescan reliability for the distal regions were poor. Future research should examine the relationship between DXA bone mineral density measurements and fracture risk at the metatarsals.

Bone mineral density in subjects using central nervous system-active medications.

PubMed

Kinjo, Mitsuyo; Setoguchi, Soko; Schneeweiss, Sebastian; Solomon, Daniel H

2005-12-01

Decreased bone mineral density defines osteoporosis according to the World Health Organization and is an important predictor of future fractures. The use of several types of central nervous system-active drugs, including benzodiazepines, anticonvulsants, antidepressants, and opioids, have all been associated with increased risk of fracture. However, it is unclear whether such an increase in risk is related to an effect of bone mineral density or to other factors, such as increased risk of falls. We sought to examine the relationship between bone mineral density and the use of benzodiazepines, anticonvulsants, antidepressants, and opioids in a representative US population-based sample. We analyzed data on adults aged 17 years and older from the Third National Health and Nutrition Examination Survey (NHANES III, 1988-1994). Total femoral bone mineral density of 7114 male and 7532 female participants was measured by dual-energy x-ray absorptiometry. Multivariable linear regression models were used to quantify the relation between central nervous system medication exposure and total femoral bone mineral density. Models controlled for relevant covariates, including age, sex, and body mass index. In linear regression models, significantly reduced bone mineral density was found in subjects taking anticonvulsants (0.92 g/cm2; 95% confidence interval [CI]: 0.89 to 0.94) and opioids (0.92 g/cm2; 95% CI: 0.88 to 0.95) compared with nonusers (0.95 g/cm2; 95% CI: 0.95 to 0.95) after adjusting for several potential confounders. The other central nervous system-active drugs--benzodiazepines or antidepressants--were not associated with significantly reduced bone mineral density. In cross-sectional analysis of NHANES III, anticonvulsants and opioids (but not benzodiazepines or antidepressants) were associated with significantly reduced bone mineral density. These findings have implications for fracture-prevention strategies.

Progranulin concentration in relation to bone mineral density among obese individuals.

PubMed

Milajerdi, Alireza; Maghbooli, Zhila; Mohammadi, Farzad; Hosseini, Banafsheh; Mirzaei, Khadijeh

2018-01-01

Adipose tissue, particularly visceral adipose tissue, secretes a variety of cytokines, among which progranulin is a glycoprotein related to the immune system. Along with other secreted proteins, progranulin may be associated with bone mineral density. The aim of this study was to find out whether there are associations between the progranulin and bone mineral density among obese people. This cross-sectional study was conducted on 244 obese participants (aged 22-52). Serum progranulin, high sensitive C-reactive protein, oxidised-low dencity lipoprotein, tumor necrosis factor-α, parathormone, vitamin D, and interleukins of 1 β, 4, 6, 10, 13, and 17 concentrations were measured. Anthropometric measurements, body composition and bone mineral density were also assessed. Serum progranulin was directly associated with interleukin-6 and interleukin-1β, while it had a negative association with interleukin-17 and tumor necrosis factor-α. We also observed a statistically significant direct association between progranulin concentration and visceral fat, abdominal fat, waist, abdominal and hip circumferences, hip T-score, and Z-score and T-score for the lumbar region. A partial correlation test has also shown a significant positive correlation regarding serum progranulin and the hip Z-score. Moreover, progranulin level is inversely associated with ospteopenia (P = 0.04 and CI: 0.17,0.96). Our study revealed that central obesity may be related to increased progranulin concentration. In addition, progranulin concentration was directly related to bone formation parameters, which indicates the protective effects of progranulin on bone density. Further studies are needed to clarify the exact mechanisms underlying these associations.

[The relationship between the parameters of mineral density of bone tissue and somatotype in women residing in the Republic of Karelia].

PubMed

Pashkova, I G; Gaivoronskiy, I V; Aleksina, L A; Kornev, M A

2014-01-01

Comprehensive anthropometric and densitometric study using the dual x-ray absorptiometry was conducted to determine the relationship between the mineral density of bone tissue and somatotype in 360 women aged 20 to 87 years, permanently residing in the Republic of Karelia. Significant direct correlation was detected between the somatotype and the amount of mineral substances in the vertebrae, bone mineral density and the area of the lumbar vertebrae. Bone mineral density level of the lumbar vertebrae was higher in women with europlastic and athletic somatotypes, which were characterized by high values of body mass and length, body muscle and fat mass. Low values of bone mineral density of vertebrae were identified in women belonging to subathletic, mesoplastic and stenoplastic somatotypes. The risk of developing osteopenia and osteoporosis is increased in women with low body muscle mass.

Understanding Referral Patterns for Bone Mineral Density Testing among Family Physicians: A Qualitative Descriptive Study.

PubMed

Munce, Sarah E P; Allin, Sonya; Carlin, Leslie; Sale, Joanna; Hawker, Gillian; Kim, Sandra; Butt, Debra A; Polidoulis, Irene; Tu, Karen; Jaglal, Susan B

2016-01-01

Introduction. Evidence of inappropriate bone mineral density (BMD) testing has been identified in terms of overtesting in low risk women and undertesting among patients at high risk. In light of these phenomena, the objective of this study was to understand the referral patterns for BMD testing among Ontario's family physicians (FPs). Methods. A qualitative descriptive approach was adopted. Twenty-two FPs took part in a semi-structured interview lasting approximately 30 minutes. An inductive thematic analysis was performed on the transcribed data in order to understand the referral patterns for BMD testing. Results. We identified a lack of clarity about screening for osteoporosis with a tendency for baseline BMD testing in healthy, postmenopausal women and a lack of clarity on the appropriate age for screening for men in particular. A lack of clarity on appropriate intervals for follow-up testing was also described. Conclusions. These findings lend support to what has been documented at the population level suggesting a tendency among FPs to refer menopausal women (at low risk). Emphasis on referral of high-risk groups as well as men and further clarification and education on the appropriate intervals for follow-up testing is warranted.

Turnover and storage of C and N in five density fractions from California annual grassland surface soils

NASA Astrophysics Data System (ADS)

Baisden, W. T.; Amundson, R.; Cook, A. C.; Brenner, D. L.

2002-12-01

We measured 14C/12C in density fractions from soils collected before and after atmospheric thermonuclear weapons testing to examine soil organic matter (SOM) dynamics along a 3 million year California soil chronosequence. The mineral-free particulate organic matter (FPOM; <1.6 g cm-3) mainly contains recognizable plant material, fungal hyphae, and charcoal. Mineral-associated light fractions (1.6-2.2 g cm-3) display partially or completely humified fine POM, while the dense fraction (>2.2 g cm-3) consists of relatively OM-free sand and OM-rich clays. Three indicators of decomposition (C:N, δ13C, and δ15N) all suggest increasing SOM decomposition with increasing fraction density. The Δ14C-derived SOM turnover rates suggest that ≥90% of FPOM turns over in <10 years. The four mineral-associated fractions contain 69-86% "stabilized" (decadal) SOM with the remainder assumed to be "passive" (millenial) SOM. Within each soil, the four mineral-associated fractions display approximately the same residence time (34-42 years in 200 kyr soil, 29-37 years in 600 kyr soil, and 18-26 years in 1-3 Myr soils), indicating that a single stabilized SOM "pool" exists in these soils and may turn over primarily as a result of soil disruption.

Effect of a Gonadotrophin-Releasing Hormone Analogue on Lung Function in Lymphangioleiomyomatosis

PubMed Central

Harari, Sergio; Cassandro, Roberto; Chiodini, Jacopo; Taveira-DaSilva, Angelo M.; Moss, Joel

2010-01-01

Background Lymphangioleiomyomatosis (LAM), a multisystem disease occurring primarily in women, is characterized by cystic lung destruction, and kidney and lymphatic tumors, caused by the proliferation of abnormal-appearing cells (ie, LAM cells) with a smooth muscle cell phenotype that express melanoma antigens and are capable of metastasizing. Estrogen receptors are present in LAM cells, and this finding, along with reports of disease progression during pregnancy or following exogenous estrogen administration, suggest the involvement of estrogens in the pathogenesis of LAM. Consequently, antiestrogen therapies have been employed in treatment. The goal of this prospective study was to evaluate the efficacy of triptorelin, a gonadotrophin-releasing hormone analogue, in 11 premenopausal women with LAM. Methods Patients were evaluated at baseline and every 3 to 6 months thereafter, for a total of 36 months. Hormonal assays, pulmonary function tests, 6-min walk tests, high-resolution CT scans of the chest, and bone mineral density studies were performed. Results Gonadal suppression was achieved in all patients. Overall, a significant decline in lung function was observed; two patients underwent lung transplantation 1 year after study enrollment, and another patient was lost to follow-up. Treatment with triptorelin was associated with a decline in bone mineral density. Conclusions Triptorelin appears not to prevent a decline in lung function in patients with LAM. Its use, however, may be associated with the loss of bone mineral density. PMID:18071009

Baseline Bone Mineral Density Measurements Key to Future Testing Intervals

MedlinePlus

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Bone mineral content and bone mineral density are lower in older than in younger females with Rett syndrome

USDA-ARS?s Scientific Manuscript database

Although bone mineral deficits have been identified in Rett syndrome (RTT), the prevalence of low bone mineral density (BMD) and its association with skeletal fractures and scoliosis has not been characterized fully in girls and women with RTT. Accordingly, we measured total body bone mineral conten...

The association between mammographic breast density and bone mineral density in the study of women's health across the nation.

PubMed

Crandall, Carolyn J; Zheng, Yan; Karlamangla, Arun; Sternfeld, Barbara; Habel, Laurel A; Oestreicher, Nina; Johnston, Janet; Cauley, Jane A; Greendale, Gail A

2007-08-01

Bone mineral density and mammographic breast density are each associated with markers of lifetime estrogen exposure. The association between mammographic breast density and bone mineral density in early perimenopausal women is unknown. We analyzed data from a cohort (n = 501) of premenopausal (no change in menstrual regularity) and early perimenopausal (decreased menstrual regularity in past 3 months) participants of African-American, Caucasian, Chinese, and Japanese ethnicity in the Study of Women's Health Across the Nation. Using multivariable linear regression, we examined the cross-sectional association between percent mammographic density and bone mineral density (BMD). Percent mammographic density was statistically significantly inversely associated with hip BMD and lumbar spine BMD after adjustment (body mass index, ethnicity, age, study site, parity, alcohol intake, cigarette smoking, physical activity, age at first childbirth) in early perimenopausal, but not premenopausal, women. In early perimenopausal women, every 0.1g/cm(2) greater hip BMD predicted a 2% lower percent mammographic density (95% confidence interval -37.0 to -0.6%, p = 0.04). Mammographic breast density is inversely associated with BMD in the perimenopausal participants of this community-based cohort. The biological underpinnings of these findings may reflect differential responsiveness of breast and bone mineral density to the steroid milieu.

The effect of retained intramedullary nails on tibial bone mineral density.

PubMed

Allen, J C; Lindsey, R W; Hipp, J A; Gugala, Z; Rianon, N; LeBlanc, A

2008-07-01

Intramedullary nailing has become a standard treatment for adult tibial shaft fractures. Retained intramedullary nails have been associated with stress shielding, although their long-term effect on decreasing tibial bone mineral density is currently unclear. The purpose of this study was to determine if retained tibial intramedullary nails decrease tibial mineral density in patients with successfully treated fractures. Patients treated with statically locked intramedullary nails for isolated, unilateral tibia shaft fractures were studied. Inclusion required that fracture had healed radiographically and that the patient returned to the pre-injury activity level. Data on patient demographic, fracture type, surgical technique, implant, and post-operative functional status were tabulated. Dual energy X-ray absorptiometry was used to measure bone mineral density in selected regions of the affected tibia and the contralateral intact tibia. Image reconstruction software was employed to ensure symmetry of the studied regions. Twenty patients (mean age 43; range 22-77 years) were studied at a mean of 29 months (range 5-60 months) following intramedullary nailing. There was statistically significant reduction of mean bone mineral density in tibiae with retained intramedullary nails (1.02 g/cm(2) versus 1.06 g/cm(2); P=0.04). A significantly greater decrease in bone mineral density was detected in the reamed versus non-reamed tibiae (-7% versus +6%, respectively; P<0.05). The present study demonstrates a small, but statistically significant overall bone mineral density decrease in healed tibiae with retained nails. Intramedullary reaming appears to be a factor potentiating the reduction of tibia bone mineral density in long-term nail retention.

Hindlimb unloading has a greater effect on cortical compared with cancellous bone in mature female rats

NASA Technical Reports Server (NTRS)

Allen, Matthew R.; Bloomfield, Susan A.

2003-01-01

This study was designed to determine the effects of 28 days of hindlimb unloading (HU) on the mature female rat skeleton. In vivo proximal tibia bone mineral density and geometry of HU and cage control (CC) rats were measured with peripheral quantitative computed tomography (pQCT) on days 0 and 28. Postmortem pQCT, histomorphometry, and mechanical testing were performed on tibiae and femora. After 28 days, HU animals had significantly higher daily food consumption (+39%) and lower serum estradiol levels (-49%, P = 0.079) compared with CC. Proximal tibia bone mineral content and cortical bone area significantly declined over 28 days in HU animals (-4.0 and 4.8%, respectively), whereas total and cancellous bone mineral densities were unchanged. HU animals had lower cortical bone formation rates and mineralizing surface at tibial midshaft, whereas differences in similar properties were not detected in cancellous bone of the distal femur. These results suggest that cortical bone, rather than cancellous bone, is more prominently affected by unloading in skeletally mature retired breeder female rats.

Anorexia Nervosa: Analysis of Trabecular Texture with CT

PubMed Central

Tabari, Azadeh; Torriani, Martin; Miller, Karen K.; Klibanski, Anne; Kalra, Mannudeep K.

2017-01-01

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 < .001), and a trend toward lower entropy (P = .07) compared with control subjects. Bone mineral density, abdominal fat area, and paraspinal muscle area were inversely associated with skewness and kurtosis and positively associated with MPP and entropy. Texture parameters, but not bone mineral density, were associated with lowest lifetime weight and duration of amenorrhea in 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 PMID:27797678

Anorexia Nervosa: Analysis of Trabecular Texture with CT.

PubMed

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 < .001), and a trend toward lower entropy (P = .07) compared with control subjects. Bone mineral density, abdominal fat area, and paraspinal muscle area were inversely associated with skewness and kurtosis and positively associated with MPP and entropy. Texture parameters, but not bone mineral density, were associated with lowest lifetime weight and duration of amenorrhea in 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.

Nanoscale X-Ray Microscopic Imaging of Mammalian Mineralized Tissue

PubMed Central

Andrews, Joy C.; Almeida, Eduardo; van der Meulen, Marjolein C.H.; Alwood, Joshua S.; Lee, Chialing; Liu, Yijin; Chen, Jie; Meirer, Florian; Feser, Michael; Gelb, Jeff; Rudati, Juana; Tkachuk, Andrei; Yun, Wenbing; Pianetta, Piero

2010-01-01

A novel hard transmission X-ray microscope (TXM) at the Stanford Synchrotron Radiation Light-source operating from 5 to 15 keV X-ray energy with 14 to 30 µm2 field of view has been used for high-resolution (30–40 nm) imaging and density quantification of mineralized tissue. TXM is uniquely suited for imaging of internal cellular structures and networks in mammalian mineralized tissues using relatively thick (50 µm), untreated samples that preserve tissue micro- and nanostructure. To test this method we performed Zernike phase contrast and absorption contrast imaging of mouse cancellous bone prepared under different conditions of in vivo loading, fixation, and contrast agents. In addition, the three-dimensional structure was examined using tomography. Individual osteocytic lacunae were observed embedded within trabeculae in cancellous bone. Extensive canalicular networks were evident and included processes with diameters near the 30–40 nm instrument resolution that have not been reported previously. Trabecular density was quantified relative to rod-like crystalline apatite, and rod-like trabecular struts were found to have 51–54% of pure crystal density and plate-like areas had 44–53% of crystal density. The nanometer resolution of TXM enables future studies for visualization and quantification of ultrastructural changes in bone tissue resulting from osteoporosis, dental disease, and other pathologies. PMID:20374681

Improvement in spine bone density and reduction in risk of vertebral fractures during treatment with antiresorptive drugs.

PubMed

Cummings, Steven R; Karpf, David B; Harris, Fran; Genant, Harry K; Ensrud, Kristine; LaCroix, Andrea Z; Black, Dennis M

2002-03-01

To estimate how much the improvement in bone mass accounts for the reduction in risk of vertebral fracture that has been observed in randomized trials of antiresorptive treatments for osteoporosis. After a systematic search, we conducted a meta-analysis of 12 trials to describe the relation between improvement in spine bone mineral density and reduction in risk of vertebral fracture in postmenopausal women. We also used logistic models to estimate the proportion of the reduction in risk of vertebral fracture observed with alendronate in the Fracture Intervention Trial that was due to improvement in bone mineral density. Across the 12 trials, a 1% improvement in spine bone mineral density was associated with a 0.03 decrease (95% confidence interval [CI]: 0.02 to 0.05) in the relative risk (RR) of vertebral fracture. The reductions in risk were greater than predicted from improvement in bone mineral density; for example, the model estimated that treatments predicted to reduce fracture risk by 20% (RR = 0.80), based on improvement in bone mineral density, actually reduce the risk of fracture by about 45% (RR = 0.55). In the Fracture Intervention Trial, improvement in spine bone mineral density explained 16% (95% CI: 11% to 27%) of the reduction in the risk of vertebral fracture with alendronate. Improvement in spine bone mineral density during treatment with antiresorptive drugs accounts for a predictable but small part of the observed reduction in the risk of vertebral fracture.

Tibial component coverage based on bone mineral density of the cut tibial surface during unicompartmental knee arthroplasty: clinical relevance of the prevention of tibial component subsidence.

PubMed

Lee, Yong Seuk; Yun, Ji Young; Lee, Beom Koo

2014-01-01

An optimally implanted tibial component during unicompartmental knee arthroplasty would be flush with all edges of the cut tibial surface. However, this is often not possible, partly because the tibial component may not be an ideal shape or because the ideal component size may not be available. In such situations, surgeons need to decide between component overhang and underhang and as to which sites must be covered and which sites could be undercovered. The objectives of this study were to evaluate the bone mineral density of the cut surface of the proximal tibia around the cortical rim and to compare the bone mineral density according to the inclusion of the cortex and the site-specific matched evaluation. One hundred and fifty consecutive patients (100 men and 50 women) were enrolled in this study. A quantitative computed tomography was used to determine the bone density of the cut tibial surface. Medial and lateral compartments were divided into anterior, middle, and posterior regions, and these three regions were further subdivided into two regions according to containment of cortex. The site-specific matched comparison (medial vs. lateral) of bone mineral density was performed. In medial sides, the mid-region, including the cortex, showed the highest bone mineral density in male and female patients. The posterior region showed the lowest bone mineral density in male patients, and the anterior and posterior regions showed the lowest bone mineral density in female patients. Regions including cortex showed higher bone mineral density than pure cancellous regions in medial sides. In lateral sides, posterior regions including cortex showed highest bone mineral density with statistical significance in both male and female patients. The anterior region showed the lowest bone mineral density in both male and female patients. The mid-region of the medial side and the posterior region of the lateral side are relatively safe without cortical coverage when the component is not flush with all edges of the tibia. Cortical coverage is strongly recommended for the prevention of subsidence of the tibial component in the posterior region of the medial side, and in the anterior region of the lateral side.

Effect of parity on bone mineral density: A systematic review and meta-analysis.

PubMed

Song, Seung Yeon; Kim, Yejee; Park, Hyunmin; Kim, Yun Joo; Kang, Wonku; Kim, Eun Young

2017-08-01

Parity has been suggested as a possible factor affecting bone health in women. However, study results on its association with bone mineral density are conflicting. PubMed, EMBASE, the Cochrane Library, and Korean online databases were searched using the terms "parity" and "bone mineral density", in May 2016. Two independent reviewers extracted the mean and standard deviation of bone mineral density measurements of the femoral neck, spine, and total hip in nulliparous and parous healthy women. Among the initial 10,146 studies, 10 articles comprising 24,771 women met the inclusion criteria. The overall effect of parity on bone mineral density was positive (mean difference=5.97mg/cm 2 ; 95% CI 2.37 to 9.57; P=0.001). The effect appears site-specific as parity was not significantly associated with the bone mineral density of the femoral neck (P=0.09) and lumbar spine (P=0.17), but parous women had significantly higher bone mineral density of the total hip compared to nulliparous women (mean difference=5.98mg/cm 2 ; 95% CI 1.72 to 10.24; P=0.006). No obvious heterogeneity existed among the included studies (femoral neck I 2 =0%; spine I 2 =31%; total hip I 2 =0%). Parity has a positive effect on bone in healthy, community-dwelling women and its effect appears site-specific. Copyright © 2017 Elsevier Inc. All rights reserved.

Structure and Function in the Lunge Feeding Apparatus: Mechanical Properties of the Fin Whale Mandible.

PubMed

Shadwick, Robert E; Goldbogen, Jeremy A; Pyenson, Nicholas D; Whale, James C A

2017-11-01

The mandibles of rorqual whales are highly modified to support loads associated with lunge-feeding, a dynamic filter feeding mechanism that is characterized by rapid changes in gape angle and acceleration. Although these structures are the largest ossified elements in animals and an important part of the rorqual engulfment apparatus, details of internal structure are limited and no direct measurements of mechanical properties exist. Likewise, the forces that are sustained by the mandibles are unknown. Here we report on the structure and mechanical behavior of the mandible of an adult fin whale. A series of transverse sections were cut at locations along the entire length of a 3.6-m left mandible recovered post-mortem from a 16-m fin whale, and CT scanned to make density maps. Cored samples 6-8 mm in diameter were tested in compression to determine the Young's modulus and strength. In addition, wet density, dry density and mineral density were measured. Dense cortical bone occupies only a relatively narrow peripheral layer while much less dense and oil-filled trabecular bone occupies the rest. Mineral density of both types is strongly correlated with dry density and CT Hounsfield units. Compressive strength is strongly correlated with Young's modulus, while strength and stiffness are both correlated with mineral density. It appears that the superficial compact layer is the main load bearing element, and that the mandible is reinforced against dorso-vental flexion that would occur during the peak loads while feeding. Anat Rec, 300:1953-1962, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Pilot-Scale Demonstration of Pefi's Oxygenated Transportation Fuels Production Technology

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

Coal-cleaning processes have been utilized to increase the heating value of coal by extracting ash-forming minerals in the coal. These processes involve the crushing or grinding of raw coal followed by physical separation processes, taking advantage of the density difference between carbonaceous particles and mineral particles. In addition to the desired increase in the heating value of coal, a significant reduction of the sulfur content of the coal fed to a combustion unit is effected by the removal of pyrite and other sulfides found in the mineral matter. WRI is assisting PulseWave to develop an alternate, more efficient method ofmore » liberating and separating the undesirable mineral matter from the carbonaceous matter in coal. The approach is based on PulseWave's patented resonance disintegration technology that reduces that particle size of materials by application of destructive resonance, shock waves, and vortex generating forces. Illinois No.5 coal, a Wyodak coal, and a Pittsburgh No.8 coal were processed using the resonance disintegration apparatus then subjected to conventional density separations. Initial microscopic results indicate that up to 90% of the pyrite could be liberated from the coal in the machine, but limitations in the density separations reduced overall effectiveness of contaminant removal. Approximately 30-80% of the pyritic sulfur and 30-50% of the mercury was removed from the coal. The three coals (both with and without the pyritic phase separated out) were tested in WRI's 250,000 Btu/hr Combustion Test Facility, designed to replicate a coal-fired utility boiler. The flue gases were characterized for elemental, particle bound, and total mercury in addition to sulfur. The results indicated that pre-combustion cleaning could reduce a large fraction of the mercury emissions.« less

Risk Factors for Low Bone Mineral Density in Individuals Residing in a Facility for the People with Intellectual Disability

ERIC Educational Resources Information Center

Jaffe, J. S.; Timell, A. M.; Elolia, R.; Thatcher, S. S.

2005-01-01

Background: Individuals with intellectual disability (ID) are known to have a high prevalence of both low bone mineral density (BMD) and fractures with significant attendant morbidity. Effective strategies aimed at reducing fractures will be facilitated by the identification of predisposing risk factors. Methods: Bone mineral density was measured…

Exercise and Bone Density: Meta-Analysis.

DTIC Science & Technology

1999-09-01

1998, (4) changes in bone mineral density (regional, total) reported in adults ages 18 years and older . Disagreements between the Principal...individual patient data. C. So What? Our work to date suggests that exercise helps to increase and maintain bone mineral density in older (>31 years of age ...between January 1962 and December 1998, (4) changes in bone mineral density (regional, total) reported in adults ages 18 years and older . If you have any

Bone Mineral Density as a Marker of Cumulative Estrogen Exposure in Psychotic Disorder: A 3 Year Follow-Up Study.

PubMed

van der Leeuw, Christine; Peeters, Sanne; Domen, Patrick; van Kroonenburgh, Marinus; van Os, Jim; Marcelis, Machteld

2015-01-01

Altered estrogen-induced neuroprotection has been implicated in the etiology of psychotic disorders. Using bone mineral density as a marker of lifetime estrogen exposure, a longitudinal family study was conducted to discriminate between etiological mechanisms and secondary effects of disease and treatment. Dual X-ray absorptiometry scans were acquired twice, with an interval of 3 years, in 30 patients with psychotic disorder (male (M)/female (F): 24/6, mean age of 32 years at second measurement), 44 non-psychotic siblings of patients with a psychotic disorder (M/F: 26/18, mean age 32) and 27 controls (M/F: 7/20, mean age 35). Total bone mineral density, Z-scores and T-scores were measured in the lumbar spine and proximal femur. Associations between group and bone mineral density changes were investigated with multilevel random regression analyses. The effect of prolactin-raising antipsychotic medication was evaluated. (Increased risk of) psychotic disorder was not associated with disproportionate bone mineral density loss over a three year period. Instead, femoral bone mineral density measures appeared to decrease less in the patient versus control comparison (total BMD: B = 0.026, 95% CI 0.002 to 0.050, p = 0.037; Z-score: B = 0.224, 95% CI 0.035 to 0.412, p = 0.020; and T-score: B = 0.193, 95% CI 0.003 to 0.382, p = 0.046). Current or past use of a prolactin-raising antipsychotic medication was not associated with bone mineral density changes. In this small longitudinal study, there was no evidence of ongoing estrogen deficiency in psychotic disorder as there was no excessive loss of bone mineral density over a 3-year period in patients using antipsychotic medication.

Bone Mineral Density as a Marker of Cumulative Estrogen Exposure in Psychotic Disorder: A 3 Year Follow-Up Study

PubMed Central

van der Leeuw, Christine; Peeters, Sanne; Domen, Patrick; van Kroonenburgh, Marinus; van Os, Jim; Marcelis, Machteld

2015-01-01

Altered estrogen-induced neuroprotection has been implicated in the etiology of psychotic disorders. Using bone mineral density as a marker of lifetime estrogen exposure, a longitudinal family study was conducted to discriminate between etiological mechanisms and secondary effects of disease and treatment. Dual X-ray absorptiometry scans were acquired twice, with an interval of 3 years, in 30 patients with psychotic disorder (male (M)/female (F): 24/6, mean age of 32 years at second measurement), 44 non-psychotic siblings of patients with a psychotic disorder (M/F: 26/18, mean age 32) and 27 controls (M/F: 7/20, mean age 35). Total bone mineral density, Z-scores and T-scores were measured in the lumbar spine and proximal femur. Associations between group and bone mineral density changes were investigated with multilevel random regression analyses. The effect of prolactin-raising antipsychotic medication was evaluated. (Increased risk of) psychotic disorder was not associated with disproportionate bone mineral density loss over a three year period. Instead, femoral bone mineral density measures appeared to decrease less in the patient versus control comparison (total BMD: B = 0.026, 95% CI 0.002 to 0.050, p = 0.037; Z-score: B = 0.224, 95% CI 0.035 to 0.412, p = 0.020; and T-score: B = 0.193, 95% CI 0.003 to 0.382, p = 0.046). Current or past use of a prolactin-raising antipsychotic medication was not associated with bone mineral density changes. In this small longitudinal study, there was no evidence of ongoing estrogen deficiency in psychotic disorder as there was no excessive loss of bone mineral density over a 3-year period in patients using antipsychotic medication. PMID:26309037

Stiff and tough: a comparative study on the tensile properties of shark skin.

PubMed

Creager, Shelby B; Porter, Marianne E

2018-02-01

In sharks, the skin is a biological composite with mineralized denticles embedded within a collagenous matrix. Swimming performance is enhanced by the dermal denticles on the skin, which have drag reducing properties produced by regional morphological variations and changes in density along the body. We used mechanical testing to quantify the effect of embedded mineralized denticles on the quasi-static tensile properties of shark skin to failure in four coastal species. We investigated regional differences in denticle density and skin properties by dissecting skin from the underlying fascia and muscle at 10 anatomical landmarks. Hourglass-shaped skin samples were extracted in the cranial to caudal orientation. Denticle density was quantified and varied significantly among both regions and species. We observed the greatest denticle densities in the cranial region of the body for the bonnethead, scalloped hammerhead, and bull sharks. Skin samples were then tested in tension until failure, stress strain curves were generated, and mechanical properties calculated. We found significant species and region effects for all three tensile mechanical properties. We report the greatest ultimate tensile strength, stiffness, and toughness near the cranial and lateral regions of the body for all 4 of the coastal species. We also report that denticle density increases with skin stiffness but decreases with toughness. Copyright © 2017 Elsevier GmbH. All rights reserved.

Measurement of hard tissue density based on image density of intraoral radiograph

NASA Astrophysics Data System (ADS)

Katsumata, Akitoshi; Fukui, Tatsumasa; Shimoda, Shinji; Kobayashi, Kaoru; Hayashi, Tatsuro

2018-02-01

We developed a DentalSCOPE computer program to measure the bone mineral density (BMD) of the alveolar bone. Mineral density measurement of alveolar bone may be useful to predict possible patients who will occur medication-related osteonecrosis of the jaw (MRONJ). Because these osteoporosis medicines affect the mineral density of alveolar bone significantly. The BMD of alveolar bone was compared between dual-energy X-ray absorptiometry (DEXA) and the DentalSCOPE program. A high correlation coefficient was revealed between the DentalSCOPE measurement and the DEXA measurement.

Dietary boron does not affect tooth strength, micro-hardness, and density, but affects tooth mineral composition and alveolar bone mineral density in rabbits fed a high-energy diet.

PubMed

Hakki, Sema S; SiddikMalkoc; Dundar, Niyazi; Kayis, Seyit Ali; Hakki, Erdogan E; Hamurcu, Mehmet; Baspinar, Nuri; Basoglu, Abdullah; Nielsen, Forrest H; Götz, Werner

2015-01-01

The objective of this study was to determine whether dietary boron (B) affects the strength, density and mineral composition of teeth and mineral density of alveolar bone in rabbits with apparent obesity induced by a high-energy diet. Sixty female, 8-month-old, New Zealand rabbits were randomly assigned for 7 months into five groups as follows: (1) control 1, fed alfalfa hay only (5.91 MJ/kg and 57.5 mg B/kg); (2) control 2, high energy diet (11.76 MJ and 3.88 mg B/kg); (3) B10, high energy diet + 10 mg B gavage/kg body weight/96 h; (4) B30, high energy diet + 30 mg B gavage/kg body weight/96 h; (5) B50, high energy diet + 50 mg B gavage/kg body weight/96 h. Maxillary incisor teeth of the rabbits were evaluated for compression strength, mineral composition, and micro-hardness. Enamel, dentin, cementum and pulp tissue were examined histologically. Mineral densities of the incisor teeth and surrounding alveolar bone were determined by using micro-CT. When compared to controls, the different boron treatments did not significantly affect compression strength, and micro-hardness of the teeth, although the B content of teeth increased in a dose-dependent manner. Compared to control 1, B50 teeth had decreased phosphorus (P) concentrations. Histological examination revealed that teeth structure (shape and thickness of the enamel, dentin, cementum and pulp) was similar in the B-treated and control rabbits. Micro CT evaluation revealed greater alveolar bone mineral density in B10 and B30 groups than in controls. Alveolar bone density of the B50 group was not different than the controls. Although the B treatments did not affect teeth structure, strength, mineral density and micro-hardness, increasing B intake altered the mineral composition of teeth, and, in moderate amounts, had beneficial effects on surrounding alveolar bone.

Aircraft compass characteristics

NASA Technical Reports Server (NTRS)

Peterson, John B; Smith, Clyde W

1937-01-01

A description of the test methods used at the National Bureau of Standards for determining the characteristics of aircraft compasses is given. The methods described are particularly applicable to compasses in which mineral oil is used as the damping liquid. Data on the viscosity and density of certain mineral oils used in United States Navy aircraft compasses are presented. Characteristics of Navy aircraft compasses IV to IX and some other compasses are shown for the range of temperatures experienced in flight. Results of flight tests are presented. These results indicate that the characteristic most desired in a steering compass is a short period and, in a check compass, a low overswing.

Mineral deposit densities for estimating mineral resources

USGS Publications Warehouse

Singer, Donald A.

2008-01-01

Estimates of numbers of mineral deposits are fundamental to assessing undiscovered mineral resources. Just as frequencies of grades and tonnages of well-explored deposits can be used to represent the grades and tonnages of undiscovered deposits, the density of deposits (deposits/area) in well-explored control areas can serve to represent the number of deposits. Empirical evidence presented here indicates that the processes affecting the number and quantity of resources in geological settings are very general across many types of mineral deposits. For podiform chromite, porphyry copper, and volcanogenic massive sulfide deposit types, the size of tract that geologically could contain the deposits is an excellent predictor of the total number of deposits. The number of mineral deposits is also proportional to the type’s size. The total amount of mineralized rock is also proportional to size of the permissive area and the median deposit type’s size. Regressions using these variables provide a means to estimate the density of deposits and the total amount of mineralization. These powerful estimators are based on analysis of ten different types of mineral deposits (Climax Mo, Cuban Mn, Cyprus massive sulfide, Franciscan Mn, kuroko massive sulfide, low-sulfide quartz-Au vein, placer Au, podiform Cr, porphyry Cu, and W vein) from 108 permissive control tracts around the world therefore generalizing across deposit types. Despite the diverse and complex geological settings of deposit types studied here, the relationships observed indicate universal controls on the accumulation and preservation of mineral resources that operate across all scales. The strength of the relationships (R 2=0.91 for density and 0.95 for mineralized rock) argues for their broad use. Deposit densities can now be used to provide a guideline for expert judgment or used directly for estimating the number of most kinds of mineral deposits.

Vitamin D Status, Bone Mineral Density and Mental Health in Young Australian Women: The Safe-D Study.

PubMed

Callegari, Emma T; Reavley, Nicola; Garland, Suzanne M; Gorelik, Alexandra; Wark, John D

2015-11-17

Vitamin D deficiency has been associated with both poor bone health and mental ill-health. More recently, a number of studies have found individuals with depressive symptoms tend to have reduced bone mineral density. To explore the interrelationships between vitamin D status, bone mineral density and mental-ill health we are assessing a range of clinical, behavioural and lifestyle factors in young women (Part A of the Safe-D study). Part A of the Safe-D study is a cross-sectional study aiming to recruit 468 young females aged 16-25 years living in Victoria, Australia, through Facebook advertising. Participants are required to complete an extensive, online questionnaire, wear an ultra-violet dosimeter for 14 consecutive days and attend a study site visit. Outcome measures include areal bone mineral measures at the lumbar spine, total hip and whole body, as well as soft tissue composition using dual energy x-ray absorptiometry. Trabecular and cortical volumetric bone density at the tibia is measured using peripheral quantitative computed tomography. Other tests include serum 25-hydroxyvitamin D, serum biochemistry and a range of health markers. Details of mood disorder/s and depressive and anxiety symptoms are obtained by self-report. Cutaneous melanin density is measured by spectrophotometry. The findings of this cross-sectional study will have implications for health promotion in young women and for clinical care of those with vitamin D deficiency and/or mental ill-health. Optimising both vitamin D status and mental health may protect against poor bone health and fractures in later life. Significance for public healthVitamin D deficiency, depression and osteoporosis are all major public health issues. Vitamin D deficiency has been associated with both reduced bone mineral density and depressive symptoms. Moreover, cohort studies have found that subjects with depression have lower bone mineral density when compared to healthy controls. Early adulthood is a critical time in young woman's lives as their independence, behaviours and lifestyle choices are established. These choices made as a young adult lay down the foundation for future health trajectories for not only for themselves but also for their potential partners and families. Addressing vitamin D deficiency, poor bone health and mental ill-health at a younger age may ultimately improve their wellbeing, productivity and long-term health outcomes. This study is of particular significance as the interplay between vitamin D, depression and bone health is currently uncertain and such knowledge is crucial for understanding, prevention and treatment of these conditions.

Calcium and Vitamin D Supplementation and Loss of Bone Mineral Density in Women Undergoing Breast Cancer Therapy

PubMed Central

Datta, Mridul; Schwartz, Gary G.

2013-01-01

An unintended consequence of breast cancer therapies is an increased risk of osteoporosis due to accelerated bone loss. We conducted a systematic review of calcium and/or vitamin D (Ca±D) supplementation trials for maintaining bone mineral density (BMD) in women with breast cancer using the “before-after” data from the Ca±D supplemented comparison group of trials evaluating the effect of drugs such as bisphosphonates on BMD. Whether Ca±D supplements increase BMD in women undergoing breast cancer therapy has never been tested against an unsupplemented control group. However, results from 16 trials indicate that the Ca±D doses tested (500-1500 mg calcium; 200-1000 IU vitamin D) were inadequate to prevent BMD loss in these women. Cardiovascular disease is the main cause of mortality in women with breast cancer. Because calcium supplements may increase cardiovascular disease risk, future trials should evaluate the safety and efficacy of Ca±D supplementation in women undergoing breast cancer therapy. PMID:23932583

Effects of antiepileptic drugs on bone mineral density and bone metabolism in children: a meta-analysis*

PubMed Central

Zhang, Ying; Zheng, Yu-xin; Zhu, Jun-ming; Zhang, Jian-min; Zheng, Zhe

2015-01-01

Objective: The aim of our meta-analysis was to assess the effects of antiepileptic drugs on bone mineral density and bone metabolism in epileptic children. Methods: Searches of PubMed and Web of Science were undertaken to identify studies evaluating the association between antiepileptic drugs and bone mineral density and bone metabolism. Results: A total of 22 studies with 1492 subjects were included in our research. We identified: (1) a reduction in bone mineral density at lumbar spine (standardized mean difference (SMD)=−0.30, 95% confidence interval (CI) [−0.61, −0.05]), trochanter (mean difference (MD)=−0.07, 95% CI [−0.10, −0.05]), femoral neck (MD=−0.05, 95% CI [−0.09, −0.02]), and total body bone mineral density (MD=−0.33, 95% CI [−0.51, −0.15]); (2) a reduction in 25-hydroxyvitamin D (MD=−3.37, 95% CI [−5.94, −0.80]) and an increase in serum alkaline phosphatase (SMD=0.71, 95% CI [0.38, 1.05]); (3) no significant changes in serum parathyroid hormone, calcium, or phosphorus. Conclusions: Our meta-analysis suggests that treatment with antiepileptic drugs may be associated with decreased bone mineral density in epileptic children. PMID:26160719

Extreme obesity reduces bone mineral density: complementary evidence from mice and women.

PubMed

Núñez, Nomelí P; Carpenter, Catherine L; Perkins, Susan N; Berrigan, David; Jaque, S Victoria; Ingles, Sue Ann; Bernstein, Leslie; Forman, Michele R; Barrett, J Carl; Hursting, Stephen D

2007-08-01

To evaluate the effects of body adiposity on bone mineral density in the presence and absence of ovarian hormones in female mice and postmenopausal women. We assessed percentage body fat, serum leptin levels, and bone mineral density in ovariectomized and non-ovariectomized C57BL/6 female mice that had been fed various calorically dense diets to induce body weight profiles ranging from lean to very obese. Additionally, we assessed percentage body fat and whole body bone mineral density in 37 overweight and extremely obese postmenopausal women from the Women's Contraceptive and Reproductive Experiences study. In mice, higher levels of body adiposity (>40% body fat) were associated with lower bone mineral density in ovariectomized C57BL/6 female mice. A similar trend was observed in a small sample of postmenopausal women. The complementary studies in mice and women suggest that extreme obesity in postmenopausal women may be associated with reduced bone mineral density. Thus, extreme obesity (BMI > 40 kg/m2) may increase the risk for osteopenia and osteoporosis. Given the obesity epidemic in the U.S. and in many other countries, and, in particular, the rising number of extremely obese adult women, increased attention should be drawn to the significant and interrelated public health issues of obesity and osteoporosis.

Biomechanical comparison of stability of tibiotalocalcaneal arthrodesis with two different intramedullary retrograde nails.

PubMed

Richter, Martinus; Evers, Julia; Waehnert, Dirk; Deorio, Jim K; Pinzur, Michael; Schulze, Martin; Zech, Stefan; Ochman, Sabine

2014-03-01

The aim of the study was to compare the initial construct stability of two retrograde intramedullary nail systems for tibiotalocalcaneal arthrodesis (TTCF) (A3, Small Bone Innovations; HAN, Synthes) in a biomechanical cadaver study. Nine pairs of human cadaver bones were instrumented with two different retrograde nail systems. One tibia from each pair was randomized to either rod. The bone mineral density was determined via tomography to ensure the characteristics in each pair of tibiae were similar. All tests were performed in load-control. Displacements and forces were acquired by the sensors of the machine at a rate of 64Hz. Specimens were tested in a stepwise progression starting with six times ±125N with a frequency of 1Hz for 250cycles each step was performed (1500cycles). The maximum load was then increased to ±250N for another 14 steps or until specimen failure occurred (up to 3500cycles). Average bone mineral density was 67.4mgHA/ccm and did not differ significantly between groups (t-test, p=.28). Under cyclic loading, the range of motion (dorsiflexion/plantarflexion) at 250N was significantly lower for the HAN-group with 7.2±2.3mm compared to the A3-group with 11.8±2.9mm (t-test, p<0.01). Failure was registered for the HAN after 4571±1134cycles and after 2344±1195cycles for the A3 (t-test, p=.031). Bone mineral density significantly correlated with the number of cycles to failure in both groups (Spearman-Rho, r>.69, p<0.01). The high specimen age and low bone density simulates an osteoporotic bone situation. The HAN with only lateral distal bend but two calcaneal locking screws showed higher stability (higher number of cycles to failure and lower motion such as dorsiflexion/plantarflexion during cyclic loading) than the A3 with additional distal dorsal bend but only one calcaneal locking screw. Both constructs showed sufficient stability compared with earlier data from a similar test model. The data suggest that both implants allow for sufficient primary stability for TTCF in osteoporotic and consequently also in non-osteoporotic bone. Not applicable, experimental basic science study. Copyright © 2013 European Foot and Ankle Society. Published by Elsevier Ltd. All rights reserved.

Associated Factors of Bone Mineral Density and Osteoporosis in Elderly Males

PubMed Central

Heidari, Behzad; Muhammadi, Abdollah; Javadian, Yahya; Bijani, Ali; Hosseini, Reza; Babaei, Mansour

2016-01-01

Background Low bone mineral density and osteoporosis is prevalent in elderly subjects. This study aimed to determine the associated factors of bone mineral density and osteoporosis in elderly males. Methods All participants of the Amirkola health and ageing project cohort aged 60 years and older entered the study. Bone mineral density at femoral neck and lumbar spine was assessed by the dual energy X-ray absorptiometry (DXA) method. Osteoporosis was diagnosed by the international society for clinical densitometry criteria and the association of bone mineral density and osteoporosis with several clinical, demographic and biochemical parameters. Multiple logistic regression analysis was used to determine independent associations. Results A total of 553 patients were studied and 90 patients (16.2%) had osteoporosis at either femoral neck or lumbar spine. Diabetes, obesity, metabolic syndrome, overweight, and quadriceps muscle strength > 30 kg, metabolic syndrome, abdominal obesity and education level were associated with higher bone mineral density and lower prevalence of osteoporosis, whereas age, anemia, inhaled corticosteroids and fracture history were associated with lower bone mineral density and higher prevalence of osteoporosis (P = 0.001). After adjustment for all covariates, osteoporosis was negatively associated only with diabetes, obesity, overweight, and QMS > 30 kg and positively associated with anemia and fracture history. The association of osteoporosis with other parameters did not reach a statistical level. Conclusions The findings of the study indicate that in elderly males, diabetes, obesity and higher muscle strength was associated with lower prevalence of osteoporosis and anemia, and prior fracture with higher risk of osteoporosis. This issue needs further longitudinal studies. PMID:28835759

The evaluation of bone mineral density based on nutritional status, age, and anthropometric parameters in elderly women.

PubMed

Ozeraitiene, Violeta; Būtenaite, Violeta

2006-01-01

To examine the relationship between bone mineral density and nutritional status, age, and anthropometrical data in elderly women. A validated international nutrition-risk-screening questionnaire, the Mini Nutritional Assessment, was used for evaluation of nutrition. The Mini Nutritional Assessment is a clinical tool consisting of four items: anthropometric assessment, global evaluation, dietetic assessment, and subjective assessment. Height and body weight were measured while the participants wore indoor clothes and no shoes; mid-arm and calf circumferences were measured with tape measure. The measurements of skinfold thickness on triceps, waist, and thigh were taken with a caliper. Bone mineral density was measured at distal radius of the nondominant forearm by dual x-ray absorptiometry. Our results indicate that anthropometric parameters (height, weight, body mass index, skinfold thickness) in elderly women with osteoporosis were the smallest. It was determined that more fats and proteins are reserved in the body, the greater the bone mineral density is. The nutritional status and age had a significant influence on bone mineral density. It was determined that women with osteoporosis had a tendency for greater malnutrition risk according to Mini Nutritional Assessment. Women with osteoporosis had worse appetites and suffered from cardiovascular diseases more often. It was determined that the nutritional status of elderly women, assessed by the Mini Nutritional Assessment questionnaire, reflects bone mineral density. It was found that women's age and anthropometric data, reflecting fat reserves in the body (body mass index, skinfold thickness), are significantly related to low bone mineral density.

Single x-ray transmission system for bone mineral density determination

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jimenez-Mendoza, Daniel; Vargas-Vazquez, Damian; Espinosa-Arbelaez, Diego G.

2011-12-15

Bones are the support of the body. They are composed of many inorganic compounds and other organic materials that all together can be used to determine the mineral density of the bones. The bone mineral density is a measure index that is widely used as an indicator of the health of the bone. A typical manner to evaluate the quality of the bone is a densitometry study; a dual x-ray absorptiometry system based study that has been widely used to assess the mineral density of some animals' bones. However, despite the success stories of utilizing these systems in many differentmore » applications, it is a very expensive method that requires frequent calibration processes to work properly. Moreover, its usage in small species applications (e.g., rodents) has not been quite demonstrated yet. Following this argument, it is suggested that there is a need for an instrument that would perform such a task in a more reliable and economical manner. Therefore, in this paper we explore the possibility to develop a new, affordable, and reliable single x-ray absorptiometry system. The method consists of utilizing a single x-ray source, an x-ray image sensor, and a computer platform that all together, as a whole, will allow us to calculate the mineral density of the bone. Utilizing an x-ray transmission theory modified through a version of the Lambert-Beer law equation, a law that expresses the relationship among the energy absorbed, the thickness, and the absorption coefficient of the sample at the x-rays wavelength to calculate the mineral density of the bone can be advantageous. Having determined the parameter equation that defines the ratio of the pixels in radiographies and the bone mineral density [measured in mass per unit of area (g/cm{sup 2})], we demonstrated the utility of our novel methodology by calculating the mineral density of Wistar rats' femur bones.« less

Single x-ray transmission system for bone mineral density determination

NASA Astrophysics Data System (ADS)

Jimenez-Mendoza, Daniel; Espinosa-Arbelaez, Diego G.; Giraldo-Betancur, Astrid L.; Hernandez-Urbiola, Margarita I.; Vargas-Vazquez, Damian; Rodriguez-Garcia, Mario E.

2011-12-01

Bones are the support of the body. They are composed of many inorganic compounds and other organic materials that all together can be used to determine the mineral density of the bones. The bone mineral density is a measure index that is widely used as an indicator of the health of the bone. A typical manner to evaluate the quality of the bone is a densitometry study; a dual x-ray absorptiometry system based study that has been widely used to assess the mineral density of some animals' bones. However, despite the success stories of utilizing these systems in many different applications, it is a very expensive method that requires frequent calibration processes to work properly. Moreover, its usage in small species applications (e.g., rodents) has not been quite demonstrated yet. Following this argument, it is suggested that there is a need for an instrument that would perform such a task in a more reliable and economical manner. Therefore, in this paper we explore the possibility to develop a new, affordable, and reliable single x-ray absorptiometry system. The method consists of utilizing a single x-ray source, an x-ray image sensor, and a computer platform that all together, as a whole, will allow us to calculate the mineral density of the bone. Utilizing an x-ray transmission theory modified through a version of the Lambert-Beer law equation, a law that expresses the relationship among the energy absorbed, the thickness, and the absorption coefficient of the sample at the x-rays wavelength to calculate the mineral density of the bone can be advantageous. Having determined the parameter equation that defines the ratio of the pixels in radiographies and the bone mineral density [measured in mass per unit of area (g/cm2)], we demonstrated the utility of our novel methodology by calculating the mineral density of Wistar rats' femur bones.

Evaluation of Different Mineral Filler Aggregates for Asphalt Mixtures

NASA Astrophysics Data System (ADS)

Wasilewska, Marta; Małaszkiewicz, Dorota; Ignatiuk, Natalia

2017-10-01

Mineral filler aggregates play an important role in asphalt mixtures because they fill voids in paving mix and improve the cohesion of asphalt binder. Limestone powder containing over 90% of CaCO3 is the most frequently used type of filler. Waste material from the production of coarse aggregate can be successfully used as a mineral filler aggregate for hot asphalt concrete mixtures as the limestone powder replacement. This paper presents the experimental results of selected properties of filler aggregates which were obtained from rocks with different mineral composition and origin. Five types of rocks were used as a source of the mineral filler aggregate: granite, gabbro, trachybasalt, quartz sandstone and rocks from postglacial deposits. Limestone filler was used in this study as the reference material. The following tests were performed: grading (air jet sieving), quality of fines according to methylene blue test, water content by drying in a ventilated oven, particle density using pyknometer method, Delta ring and ball test, Bitumen Number, fineness determined as Blaine specific surface area. Mineral filler aggregates showed significant differences when they were mixed with bitumen and stiffening effect in Delta ring and ball test was evaluated. The highest values were achieved when gabbro and granite fillers were used. Additionally, Scanning Electron Microscopy (SEM) analysis of grain shape and size was carried out. Significant differences in grain size and shape were observed. The highest non-homogeneity in size was determined for quartz sandstone, gabbro and granite filler. Their Blaine specific surface area was lower than 2800 cm2/g, while for limestone and postglacial fillers with regular and round grains it exceeded 3000 cm2/g. All examined mineral filler aggregates met requirements of Polish National Specification WT-1: 2014 and could be used in asphalt mixtures.

Association of macrophage inhibitory cytokine-1 with nutritional status, body composition and bone mineral density in patients with anorexia nervosa: the influence of partial realimentation.

PubMed

Dostálová, Ivana; Kaválková, Petra; Papežová, Hana; Domluvilová, Daniela; Zikán, Vít; Haluzík, Martin

2010-04-23

Macrophage inhibitory cytokine-1 (MIC-1) is a key inducer of cancer-related anorexia and weight loss. However, its possible role in the etiopathogenesis of nutritional disorders of other etiology such as anorexia nervosa (AN) is currently unknown. We measured fasting serum concentrations of MIC-1 in patients with AN before and after 2-month nutritional treatment and explored its relationship with nutritional status, metabolic and biochemical parameters. Sixteen previously untreated women with AN and twenty-five normal-weight age-matched control women participated in the study. We measured serum concentrations of MIC-1 and leptin by ELISA, free fatty acids by enzymatic colorimetric assay, and biochemical parameters by standard laboratory methods; determined resting energy expenditure by indirect calorimetry; and assessed bone mineral density and body fat content by dual-energy X-ray absorptiometry. ANOVA, unpaired t-test or Mann-Whitney test were used for groups comparison as appropriate. The comparisons of serum MIC-1 levels and other studied parameters in patients with AN before and after partial realimentation were assessed by paired t-test or Wilcoxon Signed Rank Test as appropriate. At baseline, fasting serum MIC-1 concentrations were significantly higher in patients with AN relative to controls. Partial realimentation significantly reduced serum MIC-1 concentrations in patients with AN but it still remained significantly higher compared to control group. In AN group, serum MIC-1 was inversely related to Buzby nutritional risk index, serum insulin-like growth factor-1, serum glucose, serum total protein, serum albumin, and lumbar bone mineral density and it significantly positively correlated with the duration of AN and age. MIC-1 concentrations in AN patients are significantly higher relative to healthy women. Partial realimentation significantly decreased MIC-1 concentration in AN group. Clinical significance of these findings needs to be further clarified.

Treatment of low bone density in young people with cystic fibrosis: a multicentre, prospective, open-label observational study of calcium and calcifediol followed by a randomised placebo-controlled trial of alendronate.

PubMed

Bianchi, Maria Luisa; Colombo, Carla; Assael, Baroukh M; Dubini, Antonella; Lombardo, Mariangela; Quattrucci, Serena; Bella, Sergio; Collura, Mirella; Messore, Barbara; Raia, Valeria; Poli, Furio; Bini, Rita; Albanese, Carlina V; De Rose, Virginia; Costantini, Diana; Romano, Giovanna; Pustorino, Elena; Magazzù, Giuseppe; Bertasi, Serenella; Lucidi, Vincenzina; Traverso, Gabriella; Coruzzo, Anna; Grzejdziak, Amelia D

2013-07-01

Long-term complications of cystic fibrosis include osteoporosis and fragility fractures, but few data are available about effective treatment strategies, especially in young patients. We investigated treatment of low bone mineral density in children, adolescents, and young adults with cystic fibrosis. We did a multicentre trial in two phases. We enrolled patients aged 5-30 years with cystic fibrosis and low bone mineral density, from ten cystic fibrosis regional centres in Italy. The first phase was an open-label, 12-month observational study of the effect of adequate calcium intake plus calcifediol. The second phase was a 12-month, double-blind, randomised, placebo-controlled, parallel group study of the efficacy and safety of oral alendronate in patients whose bone mineral apparent density had not increased by 5% or more by the end of the observational phase. Patients were randomly assigned to either alendronate or placebo. Both patients and investigators were masked to treatment assignment. We used dual x-ray absorptiometry at baseline and every 6 months thereafter, corrected for body size, to assess lumbar spine bone mineral apparent density. We assessed bone turnover markers and other laboratory parameters every 3-6 months. The primary endpoint was mean increase of lumbar spine bone mineral apparent density, assessed in the intention-to-treat population. This study is registered with ClinicalTrials.gov, number NCT01812551. We screened 540 patients and enrolled 171 (mean age 13·8 years, SD 5·9, range 5-30). In the observational phase, treatment with calcium and calcifediol increased bone mineral apparent density by 5% or more in 43 patients (25%). 128 patients entered the randomised phase. Bone mineral apparent density increased by 16·3% in the alendronate group (n=65) versus 3·1% in the placebo group (n=63; p=0·0010). 19 of 57 young people (33·3%) receiving alendronate attained a normal-for-age bone mineral apparent density Z score. In the observational phase, five patients had moderate episodes of hypercalciuria, which resolved after short interruption of calcifediol treatment. During the randomised phase, one patient taking alendronate had mild fever versus none in the placebo group; treatment groups did not differ significantly for other adverse events. Correct calcium intake plus calcifediol can improve bone mineral density in some young patients with cystic fibrosis. In those who do not respond to calcium and calcifediol alone, alendronate can safely and effectively increase bone mineral density. Telethon Foundation (Italy). Copyright © 2013 Elsevier Ltd. All rights reserved.

Effect of zoledronic acid on reducing femoral bone mineral density loss following total hip arthroplasty: A meta-analysis from randomized controlled trails.

PubMed

Gao, Jian; Gao, Chong; Li, Hui; Wang, Guo-Sheng; Xu, Chang; Ran, Jian

2017-11-01

This meta-analysis aimed to assess the efficiency of intravenous administration of zoledronic acid on reducing femoral periprosthetic bone mineral density loss in patients undergoing primary total hip arthroplasty (THA). A systematic search was performed in Medline (1966-2017.07.31), PubMed (1966-2017.07.31), Embase (1980-2017.07.31), ScienceDirect (1985-2017.07.31) and the Cochrane Library (1966-2017.07.31). Fixed/random effect model was used according to the heterogeneity tested by I 2 statistic. Sensitivity analysis was conducted and publication bias was assessed. Meta-analysis was performed using Stata 11.0 software. Four studies including 185 patients met the inclusion criteria. The present meta-analysis indicated that there were significant differences between groups in terms of periprosthetic bone mineral density in Gruen zone 1 (SMD = 0.752, 95% CI: 0.454 to 1.051, P = 0.000), 2 (SMD = 0.524, 95% CI: 0.230 to 0.819, P = 0.000), 4 (SMD = 0.400, 95% CI: 0.107 to 0.693, P = 0.008), 6 (SMD = 0.893, 95% CI: 0.588 to 1.198, P = 0.000) and 7 (SMD = 0.988, 95% CI: 0.677 to 1.300, P = 0.000). Intravenous administration of zoledronic acid could significantly reduce periprosthetic bone mineral density loss (Gruen zone 1, 2, 4, 6 and 7) after THA. In addition, no severe adverse events were identified. High-quality RCTs with large sample size were still required. Copyright © 2017 IJS Publishing Group Ltd. Published by Elsevier Ltd. All rights reserved.

Bone formation by three-dimensional stromal osteoblast culture in biodegradable polymer scaffolds

NASA Technical Reports Server (NTRS)

Ishaug, S. L.; Crane, G. M.; Miller, M. J.; Yasko, A. W.; Yaszemski, M. J.; Mikos, A. G.; McIntire, L. V. (Principal Investigator)

1997-01-01

Bone formation was investigated in vitro by culturing stromal osteoblasts in three-dimensional (3-D), biodegradable poly(DL-lactic-co-glycolic acid) foams. Three polymer foam pore sizes, ranging from 150-300, 300-500, and 500-710 microns, and two different cell seeding densities, 6.83 x 10(5) cells/cm2 and 22.1 x 10(5) cells/cm2, were examined over a 56-day culture period. The polymer foams supported the proliferation of seeded osteoblasts as well as their differentiated function, as demonstrated by high alkaline phosphatase activity and deposition of a mineralized matrix by the cells. Cell number, alkaline phosphatase activity, and mineral deposition increased significantly over time for all the polymer foams. Osteoblast foam constructs created by seeding 6.83 x 10(5) cells/cm2 on foams with 300-500 microns pores resulted in a cell density of 4.63 x 10(5) cells/cm2 after 1 day in culture; they had alkaline phosphatase activities of 4.28 x 10(-7) and 2.91 x 10(-6) mumol/cell/min on Days 7 and 28, respectively; and they had a cell density that increased to 18.7 x 10(5) cells/cm2 by Day 56. For the same constructs, the mineralized matrix reached a maximum penetration depth of 240 microns from the top surface of the foam and a value of 0.083 mm for mineralized tissue volume per unit of cross sectional area. Seeding density was an important parameter for the constructs, but pore size over the range tested did not affect cell proliferation or function. This study suggests the feasibility of using poly(alpha-hydroxy ester) foams as scaffolding materials for the transplantation of autogenous osteoblasts to regenerate bone tissue.

Correlation of Bone Mineral Density on Quality of Life in Patients with Osteogenesis Imperfecta during Treatment with Denosumab.

PubMed

Hoyer-Kuhn, Heike; Stark, Christina; Franklin, Jeremy; Schoenau, Eckhard; Semler, Oliver

2017-11-01

Osteogenesis imperfecta (OI) is a rare hereditary skeletal disease leading to recurrent fractures, short stature and impaired mobility. The phenotype varies from mildly affected patients to perinatal lethal forms. In most cases an impaired collagen production due to mutations in COL1A1 or COL1A2 cause this hereditary bone fragility syndrome with an autosomal dominant inheritance. Currently an interdisciplinary therapeutic approach with antiresorptive drugs, physiotherapy and surgical procedures is the state of the art therapy. The effect of such a therapy is evaluated by measuring different surrogate parameters like areal bone mineral density or by using different mobility tests or questionnaires. Up till now the impact of these parameters on quality of life of the patients is not evaluated. Currently pharmacological strategies are based on antiresorptive treatment with bisphosphonates. In this trial we investigated the effect of an antiresorptive therapy with the monoclonal antibody denosumab decreasing the activity of osteoclasts. Denosumab was administered subcutaneously in a dose of 1mg/kg body weight in 10 children with OI (5-10 years of age) every 12 weeks for 48 weeks. Areal bone mineral density, mobility, pain scores and quality of life were measured. The results showed a good effect of the treatment on bone mineral density but this improvement showed no correlation to pain and quality of life. In conclusion further trials have to define parameters to assess interventions which influence activities of daily life of the patients. An interdisciplinary approach including physicians, basic researchers and patient organisation is needed to focus research on topics improving quality of life of patients with severe skeletal diseases. Copyright© of YS Medical Media ltd.

[Dietary patterns in college freshmen and its relation to bone mineral density].

PubMed

Wang, Sufang; Mu, Min; Zhao, Yan; Wang, Xiaoqin; Shu, Long; Li, Qingyan; Li, Yingchun

2012-07-01

In order to investigate the bone density of freshmen, and to analyze the association between dietary pattern and bone mineral density (BMD). A questionnaire survey on the situation of dietary pattern was conducted in 1414 freshmen. Effective dietary survey questionnaires and bone mineral density measurements were completed for 1319 participants. Bone mass was assessed by using an Ultrasound Bone Densitometer on the right calcaneus (CM-200, Furuno Electric Corporation, Japan), and the speed of sound (SOS, m/s) was used as an indicator for bone density. Factor analysis with varimax rotation was used to identify the dietary patterns. After adjusting for confounders, covariance with Bonferroni's was used to further examine the associations between dietary patterns and bone mineral density (BMD). (1) Four major dietary patterns were noticed. Western food pattern (high consumption in hamburger, fried food, nuts, biscuit, chocolate, cola, coffee, sugars). Animal protein pattern (high consumption in pork, mutton, beef, poultry meat, animal liver). Calcium pattern (high consumption in fresh fruits, eggs, fish and shrimps, kelp laver and sea fish, milk and dairy products, beans and bean products). Traditional Chinese pattern (high consumption in rice and grain, fresh fruits, fresh vegetables, pork). (2) No association was observed between the western food pattern and bone mineral density. High animal protein pattern showed lower SOS value compared with low animal protein pattern. High calcium pattern showed higher SOS value compared with low calcium pattern. High traditional Chinese pattern showed higher SOS value compared with the low traditional Chinese pattern. Dietary patterns are closely related with bone mineral density (BMD) of freshmen.

[The burden of disease attributed to low bone mineral density among population aged ≥40 years old in China, 1990 and 2013].

PubMed

Zhao, Z P; Ai, H H; Li, Y C; Wang, L M; Yin, P; Zhang, M; Deng, Q; Huang, Z J; Liu, J M; Liu, Y N; Gao, Y J; Zhou, M G

2016-09-06

Objective: To identify cause-specific death and attributed burden of low bone mineral density in China among population aged ≥40 years old , 1990 and 2013. Methods: By using data from Global Burden of Disease(GBD)2013, this study analyzed death caused by low mineral density, and disability-adjusted life years(DALY)among population aged 40 and above in China(not including Taiwan, China). This study also analyzed DALY by composition of injury which due to low bone mineral density. It also analyzed changes in DALY by provinces in China, 1990 and 2013. An average world population age-structure for the period 2000- 2025 was adopted to calculate the age standardized rates. Results: In 2013, there were 38.1 thousands male and 30.7 thousands female who aged 40 and above dead due to low bone mineral density in China. The burden of injury caused by low bone mineral density was more sever in male than female, which accounted for 1.525 million DALY in male and 0.873 million DALY in female. In 1990, low bone mineral density attributed transportation and accidental injury caused 0.794 million and 0.567 million DALY losses, respectively. In 2013, low bone mineral density attributed transportation and accidental injury caused 1.421 million and 0.951 million DALY losses, respectively. Compared to 1990, DALY losses caused by transportation and accidental injury, increased by 79.1% and 67.6%, respectively. In 1990, DALY rate losses due to low bone mineral density attributed transportation and accidental injury were 68.1 per 100 000 and 48.7 per 100 000, respectively. In 2013, DALY rate losses due to low bone mineral density attributed transportation and accidental injury were 102.0 per 100 000 and 68.2 per 100 000, respectively. Compared to 1990, DALY rates which caused by transportation and accidental injury, increased by 49.8% and 40.2%, respectively. According to the ranking of standardized DALY rate in 2013 by provinces, the top 3 provinces, which standardized DALYs attributed to low bone mineral density lost the most, were Zhejiang Province(2.6 per 100 000), Jiangsu Province(2.4 per 100 000), and Fujian Province(2.2 per 100 000). Compared to 1990, the standardized rate of DALY decreased in 27 provinces, while the DALY rate increased in only 6 provinces which included Ningxia Hui Autonomous Region, Qinghai Province, Hebei Province, Guangxi Zhuang Autonomous Region, and Henan Province and Xinjiang Uygur Autonomous Region. Conclusion: This study found that the burden of health losses attributed to it was higher in men than in women. Compared to 1990, DALY rates decreased in most of the provinces, however, the rates of losses of DALY which caused by transportation and accidental injury were still increasing.

[High prevalence of osteoporosis in asymptomatic postmenopausal Mapuche women].

PubMed

Ponce, Lucía; Larenas, Gladys; Riedemann, Pablo

2002-12-01

Genetic and environmental factors are responsible for variations in the frequency of osteoporosis. Prevalence of osteoporosis in Mapuche women (native Chileans) is unknown. To assess the prevalence and risk factors for osteoporosis in Mapuche women. A random sample of 95 asymptomatic postmenopausal Mapuche females, stratified by age, was studied. Women with diseases or medications that could interfere with calcium metabolism were excluded. Spine and femoral neck bone mass density was determined using a Lunar DPX Alpha densitometer. Seventeen percent of women had normal bone mineral density in both spine and femoral neck. In the spine, 25.3% had a normal bone mineral density, 17.9% had osteopenia and 56.8% had osteoporosis. In the femoral neck, 34.7% had a normal bone mineral density, 57.9% had osteopenia, and 7.4% had osteoporosis. There was a positive correlation between bone mineral density and body mass index. Women with more than one hour per day of physical activity, had a significantly lower proportion of osteopenia or osteoporosis. No association between bone mineral density and parity or calcium intake, was observed. There is a high prevalence of osteopenia and osteoporosis among Mapuche women. Osteoporosis was associated with low body mass index.

Physical performance in relation to body composition and bone mineral density in healthy, overweight, and obese postmenopausal women.

PubMed

Shin, Hyehyung; Liu, Pei-Yang; Panton, Lynn B; Ilich, Jasminka Z

2014-01-01

Diminished physical performance can be detrimental among the older adults, causing falls and subsequent fractures, loss of independence, and increased morbidity and mortality rates. Therefore, it is important to maintain functional ability from the early onset of aging. The purpose of this study was to investigate the relationship between physical performance measures and body composition (bone, fat, and lean mass) in healthy, overweight and obese, early postmenopausal white women. A total of 97 participants aged 56.0 (4.4) years (mean (SD)) with body mass index of 31.0 (4.6) kg/m(2) were included. Weight and height were recorded and 3 days of dietary records and physical activity were collected. Dual-energy x-ray absorptiometry measurements for body composition and bone mineral density were performed. Fasting blood samples were used for serum 25-hydroxy vitamin D (25OHD) analysis. Measures of physical performance included handgrip strength, 8-meter walking speed, one-leg-stance time, 8-foot Timed Get-Up-and-Go Test, and chair sit-to-stand test. Results showed that higher lean mass was related to better physical performance on items assessing body strength, including handgrip (r ranged from 0.22 to 0.25, P < .05) while higher body fat was related to the poorer physical performance in each of the assessed measures. Bone mineral density of the forearm was positively related to the handgrip strength (r = 0.207, P < .05). In regression analyses (controlled for age, weight, height, serum 25OHD status, calcium intake, physical activity, and smoking), fat mass of the lower extremities was inversely related to walking speed, one-leg-stance time, and Get-Up-and-Go measures, all crucial for mobility (r(2) = 0.13-0.23, P < .05). Overall, higher fat and lower lean mass was related to poorer physical performance, while forearm bone mineral density was related to the handgrip strength only. Further investigation may be beneficial for a better understanding of how body composition may prevent decline in physical performance among overweight/obese, mid-age, and older women.

Mechanical torque measurement in the proximal femur correlates to failure load and bone mineral density ex vivo.

PubMed

Grote, Stefan; Noeldeke, Tatjana; Blauth, Michael; Mutschler, Wolf; Bürklein, Dominik

2013-06-07

Knowledge of local bone quality is essential for surgeons to determine operation techniques. A device for intraoperative measurement of local bone quality has been developed by the AO-Research Foundation (Densi - Probe®). We used this device to experimentally measure peak breakaway torque of trabecular bone in the proximal femur and correlated this with local bone mineral density (BMD) and failure load. Bone mineral density of 160 cadaver femurs was measured by ex situ dualenergy X-ray absorptiometry. The failure load of all femurs was analyzed by side-impact analysis. Femur fractures were fixed and mechanical peak torque was measured with the DensiProbe® device. Correlation was calculated whereas correlation coefficient and significance was calculated by Fisher's Ztransformation. Moreover, linear regression analysis was carried out. The unpaired Student's t-test was used to assess the significance of differences. The Ward triangle region had the lowest BMD with 0.511 g/cm(2) (±0.17 g/cm(2)), followed by the upper neck region with 0.546 g/cm(2) (±0.16 g/cm(2)), trochanteric region with 0.685 g/cm(2) (±0.19 g/cm(2)) and the femoral neck with 0.813 g/cm(2) (±0.2 g/cm(2)). Peak torque of DensiProbe® in the femoral head was 3.48 Nm (±2.34 Nm). Load to failure was 4050.2 N (±1586.7 N). The highest correlation of peak torque measured by Densi Probe® and load to failure was found in the femoral neck (r=0.64, P<0.001). The overall correlation of mechanical peak torque with T-score was r=0.60 (P<0.001). A correlation was found between mechanical peak torque, load to failure of bone and BMD in vitro. Trabecular strength of bone and bone mineral density are different aspects of bone strength, but a correlation was found between them. Mechanical peak torque as measured may contribute additional information about bone strength, especially in the perioperative testing.

The effect of topiramate and lamotrigine on rat bone mass, structure and metabolism.

PubMed

Simko, Julius; Fekete, Sona; Gradosova, Iveta; Malakova, Jana; Zivna, Helena; Valis, Martin; Palicka, Vladimir; Zivny, Pavel

2014-05-15

There is only limited data concerning the effect of the newer antiepileptic drugs on bone. The objective of this study was to determine the effect of topiramate (TPM) and lamotrigine (LTG) monotherapy on bone mineral density (BMD), mineral content (BMC), bone markers, body composition and bone mechanical strength in the orchidectomized (ORX) rat model. 24 orchidectomized Wistar rats were divided into control and test groups, 8 rats in each group. The control rats received standard laboratory diet (SLD) while rats in the test group were fed with SLD enriched with LTG or TPM for 12 weeks. Dual energy X-ray absorptiometry was used to measure bone mineral density. The concentrations of bone metabolism markers were assayed in bone homogenate. In addition, both femurs were measured and used for biomechanical testing. Compared to the control group, both test groups had significantly lower weight, fat mass, whole body and femur BMD, BMC and reduced mechanical strength of bone. All of these changes were more pronounced in rats exposed to LTG. In conclusion, both LTG and TPM significantly reduce BMD and body weight and impair mechanical strength of bone. A question arises as to the degree of dependence of the effect on the dose. Further studies are warranted to establish whether LTG and TPM may have a clinically significant effect on BMD exclusively in the model of gonadectomized rats, or whether the effect applies also in the model of gonadally intact animals, and in the respective human models. Copyright © 2014 Elsevier B.V. All rights reserved.

Bone mineral density at the hip predicts mortality in elderly men.

PubMed

Trivedi, D P; Khaw, K T

2001-01-01

Low bone density as assessed by calcaneal ultrasound has been associated with mortality in elderly men and women. We examined the relationship between bone density measured at the hip and all cause and cardiovascular mortality in elderly men. Men aged 65-76 years from the general community were recruited from general practices in Cambridge between 1991 and 1995. At baseline survey, data collection included health questionnaires, measures of anthropometry and cardiovascular risk factors, as well as bone mineral density (BMD) measured using dual energy X-ray absorptiometry. All men have been followed up for vital status up to December 1999. BMD was significantly inversely related to mortality from all causes and cardiovascular disease, with decreasing rates with increasing bone density quartile, and an approximate halving of risk between the bottom and top quartile (p < 0.002, test for trend all causes and p < 0.025, test for trend for cardiovascular deaths). In multivariate analyses using the Cox proportional hazards model, an increase of 1 standard deviation (0.144 g/cm2) in total hip bone density was significantly associated with an age-adjusted 0.77 relative risk (95% CI 0.66-0.91) for all-cause mortality and 0.76 relative risk (95% CI 0.62-0.93) for cardiovascular disease mortality. The association remained significant after adjusting for age, body mass index, cigarette smoking status, serum cholesterol, systolic blood pressure, past history of heart attack, stroke or cancer and other lifestyle factors which included use of alcohol, physical activity and general health status. Low bone density at the hip is thus a strong and independent predictor of all-cause and cardiovascular mortality in older men.

Effects of a short-term whole body vibration intervention on bone mass and structure in elderly people.

PubMed

Gómez-Cabello, Alba; González-Agüero, Alejandro; Morales, Silvia; Ara, Ignacio; Casajús, José A; Vicente-Rodríguez, Germán

2014-03-01

We aimed to clarify whether a short-term whole body vibration training has a beneficial effect on bone mass and structure in elderly men and women. Randomised controlled trial. A total of 49 non-institutionalised elderly (20 men and 29 women) volunteered to participate in the study. Participants who met the inclusion criteria were randomly assigned to one of the study groups (whole body vibration or control). A total of 24 elderly trained squat positioned on a vibration platform 3 times per week for 11 weeks. Bone-related variables were assessed by dual-energy X-ray absorptiometry and peripheral quantitative computed tomography. Two-way repeated measures one-way analysis of variance (group by time) was used to determine the effects of the intervention on the bone-related variables and also to determinate the changes within group throughout the intervention period. Analysis of covariance was used to test the differences between groups for bone-related variables in pre- and post-training assessments and in the percentage of change between groups. All analysis were carried out including age, height, subtotal lean mass and daily calcium intake as covariates. 11 weeks of whole body vibration training led to no changes in none of the bone mineral content and bone mineral density parameters measured by dual-energy X-ray absorptiometry through the skeleton. At the tibia, total, trabecular and cortical volumetric bone mineral density decreased significantly in the whole body vibration group (all P<0.05). A short-term whole body vibration therapy is not enough to cause any changes on bone mineral content or bone mineral density and it only produces a slight variation on bone structure among elderly people. Copyright © 2013 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Prediction of low bone mass using a combinational approach of cortical and trabecular bone measures from dental panoramic radiographs.

PubMed

Kathirvelu, D; Anburajan, M

2014-09-01

The aim of this study is to extract cortical and trabecular features of the mandible and to develop a novel combinational model of mandibular cortical thickness, trabecular bone area and age in order to predict low bone mineral density or osteoporosis from a dental panoramic radiograph. The study involved 64 south Indian women (age = 52.5 ± 12.7 years) categorised into two groups (normal and low bone mineral density) based on total femur bone mineral density. The dental panoramic radiographs were obtained by a digital scanner, and measurement of total bone mineral density at the right femur was performed by a dual-energy X-ray absorptiometry scanner. The mandibular cortical thickness and panoramic mandibular index were measured bilaterally, and the mean values were considered. The region of interest of 128 × 128 pixels around the mental foramen region was manually cropped and subjected to pre-processing, normalisation and average threshold-based segmentation to determine trabecular bone area. Multiple linear regression analyses of cortical and trabecular measures along with age were performed to develop a combinational model to classify subjects as normal and low bone mineral density. The proposed approach demonstrated strong correlation (r = 0.76; p < 0.01) against the total bone mineral density and resulted in accuracy, sensitivity and positive predictive values of 0.84, 0.92 and 0.85, respectively; the receiver operating characteristic outcomes disclosed that the area under the curve was 0.89.Our results suggest that the proposed combinational model could be useful to diagnose subjects with low bone mineral density. © IMechE 2014.

Minnesota retrofit insulation in situ test program

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1978-06-01

The use of cellulose, glass fiber, rock/slag fiber and urea formaldehyde installed as retrofit insulation materials in residential walls and ceilings was studied. Homes were selected for testing according to the type of retrofit insulation, age of retrofit insulation and whether the retrofit was in the wall or ceiling. The total project was comprised of 22 wall and 48 ceiling samples. Samples of retrofit insulation were taken from an area of three to four square feet in the ceiling or wall of the home. The sample volume was measured, the sample removed and double-sealed in polyethylene bags. The samples weremore » shipped to the laboratory for testing. Laboratory measurements were made of density, moisture content, thermal resistance, and relative flammability of each sample. Additionally, the friability and compressive strength of each urea-formaldehyde foam sample was measured. The following results were obtained. Cellulosic loose fill insulation tests indicated that settling and moisture build-up are not serious problems. Flammability is a concern. Age did not affect the properties of the cellulosic loose fill, but fungal growth was evident. Shrinkage, ranging from 2.5 to 9 percent, averaging 4.5 percent, was exhibited. Degradation of the foam samples with time did not occur. Density was the most critical property affecting the other properties. The higher the density, the higher the thermal resistence per inch, the lower the friability and the higher the compressive strength. The accurate prediction of the fiber diameter, amount of unfiberized mineral, and extent of modular clumping thermal resistance of loose fill mineral fiber insulations is related to and is not solely a factor of density. The materials in this sample did not noticeably affect the structure or wiring of the retrofitted homes. (LCL)« less

Applied anatomic site study of palatal anchorage implants using cone beam computed tomography.

PubMed

Lai, Ren-fa; Zou, Hui; Kong, Wei-dong; Lin, Wei

2010-06-01

The purpose of this study was to conduct quantitative research on bone height and bone mineral density of palatal implant sites for implantation, and to provide reference sites for safe and stable palatal implants. Three-dimensional reformatting images were reconstructed by cone beam computed tomography (CBCT) in 34 patients, aged 18 to 35 years, using EZ Implant software. Bone height was measured at 20 sites of interest on the palate. Bone mineral density was measured at the 10 sites with the highest implantation rate, classified using K-mean cluster analysis based on bone height and bone mineral density. According to the cluster analysis, 10 sites were classified into three clusters. Significant differences in bone height and bone mineral density were detected between these three clusters (P<0.05). The greatest bone height was obtained in cluster 2, followed by cluster 1 and cluster 3. The highest bone mineral density was found in cluster 3, followed by cluster 1 and cluster 2. CBCT plays an important role in pre-surgical treatment planning. CBCT is helpful in identifying safe and stable implantation sites for palatal anchorage.

Bone mineral density level by dual energy X-ray absorptiometry in rheumatoid arthritis.

PubMed

Makhdoom, Asadullah; Rahopoto, Muhammad Qasim; Awan, Shazia; Tahir, Syed Muhammad; Memon, Shazia; Siddiqui, Khaleeque Ahmed

2017-01-01

To observe the level of bone mineral density by Dual Energy X-ray Absorptiometry in rheumatoid arthritis patients. The observational study was conducted at Liaquat University of Medical and Health Sciences, Jamshoro, Pakistan, from January 2011 to December 2014. Bone mineral density was measured from the femoral neck, ward's triangle and lumbar spine, in patients 25-55 years of age, who were diagnosed with rheumatoid arthritis. All the cases were assessed for bone mineral density from appendicular as well as axial skeleton. Data was collected through a designed proforma and analysis was performed using SPSS 21. Of the 229 rheumatoid arthritis patients, 33(14.4%) were males. Five (15.1%) males had normal bone density, 14(42.4%) had osteopenia and 14(42.4%) had osteoporosis. Of the 196(85.5%) females, 45(29.9%) had normal bone density, 72 (37.7%) had osteopenia and 79(40.30%) had osteoporosis. Of the 123(53.7%) patients aged 30-50 years, 38(30.9%) had normal bone density, 59(48.0%) had osteopenia, and 26(21.1%) had osteoporosis. Of the 106(46.3%) patients over 50 years, 12(11.3%) had normal bone density, 27 (25.5%) had osteopenia and 67(63.2%) had osteoporosis. Osteoporosis and osteopenia were most common among rheumatoid arthritis patients. Assessment of bone mineral density by Dual Energy X-ray Absorptiometry can lead to quick relief in the clinical symptoms with timely therapy.

Geotechnical and mineralogical characteristics of marl deposits in Jordan

NASA Astrophysics Data System (ADS)

Shaqour, Fathi M.; Jarrar, Ghaleb; Hencher, Steve; Kuisi, Mostafa

2008-10-01

Marls and marly limestone deposits cover most of Northern Jordan, where Amman City and its suburbs are located. These deposits serve as foundations for most buildings and roads as well as fill material for structural back filling, especially road bases and sub-bases. The present study aims at investigating the geotechnical characteristics and mineral composition of the marl units of these deposits through field investigations and laboratory testing. Using X-ray diffraction technique along with chemical analysis, representative samples of marl horizons were tested for mineral composition, and for a set of index and geotechnical properties including: specific gravity, grain size, Atterberg limits, Proctor compaction and shear strength properties. The test results show a positive linear relationship as expected between the clay content and both liquid and plastic limits. The tests results also show an inverse linear relationship between the clay content and the maximum dry density in both standard and modified compaction. This is attributed to the adsorption of water by the clay minerals. The relationship is more prominent in the case of modified compaction test. The results also indicate a similar relationship for the angle of internal friction. No clear correlation between cohesion and clay content was apparent.

LOW BONE MINERAL DENSITY AMONG PATIENTS WITH NEWLY DIAGNOSED RHEUMATOID ARTHRITIS.

PubMed

Arain, Shafique Rehman; Riaz, Amir; Nazir, Lubna; Umer, Tahira Perveen; Rasool, Tabe

2016-01-01

Osteoporosis is an early and common feature in rheumatoid arthritis. Apart from other manifestations, Osteoporosis is an extra-articular manifestation of rheumatoid arthritis whichmay result in increased risk of fractures, morbidity mortality, and associated healthcare costs. This study evaluates bone mineral density changes in patients withrheumatoid arthritis of recent-onset. This cross sectional descriptive study was conducted in the Rheumatology Department of a tertiary care hospital in Karachi. Data was collected from 76 patients presenting with seropositive or seronegative rheumatoid arthritis. Bone mineral density of these patients measured at lumbar spine and hip by using dual energy x-ray absorptiometrys can. Variables like age, gender, BMI, menstrual status, disease duration, erythrocyte sedimentation rate, vitamin D level, clinical disease activity index and seropositivity for rheumatoid arthritis were measured along with outcome variables. A total of 104 patients fulfilling inclusion criteria were registered with 28 excluded from study. A mong the remaining 76 patients, 68 (89.50%) were female, with mean age of patients (with low bone mineral density) as 50.95 ± 7.87 years. Nineteen (25%) patients had low bone mineral density, 68.52% had low BMD at spine while 10.52% at hip and 21.05% at spine and hip both. Low bone mineral density was found higher in patients with seronegative 7 (50%) as compared to seropositive patients 12 (19.4%) (p-value 0.017), whereas low bone mineral d ensity was found higher 12 (70.6%) among post-menopausal women. Low BMD was found in 25% of patients at earlier stage of the rheumatoid arthritis with seropositivity, age and menopausal status as significant risk factors.

Bone Mineral Density of Indian Children and Adolescents with Cystic Fibrosis.

PubMed

Gupta, Sumita; Mukherjee, Aparna; Khadgawat, Rajesh; Kabra, Madhulika; Lodha, Rakesh; Kabra, Sushil K

2017-07-15

To document bone mineral density of children and adolescents with cystic fibrosis. Cross-sectional study. Tertiary-care center of Northern India, July 2012 to August 2015. 52 children aged 6-18 years with cystic fibrosis and 62 healthy controls of similar age and sex. Both patients and controls were stratified into two groups, as pre-pubertal and peri-/post-pubertal, and compared for whole body bone mineral density, measured using dual energy X-ray absorptiometry. Serum levels of calcium, phosphate, alkaline phosphatase, 25-hydroxyvitamin D and parathyroid hormone were measured in children with cystic fibrosis. Compared with controls, the mean (SD) bone mineral density of children with cystic fibrosis was significantly lower in both the pre-pubertal (0.7 (0.1) g/cm2 vs 0.9 (0.1) g/cm2; P<0.001)) and peri-/post-pubertal groups (0.9 (0.1) g/cm2 vs 1.1 (0.1) g/cm2; P<0.001). Also, the mean (SD) bone mineral apparent density of pre-pubertal and peri-/post-pubertal cystic fibrosis patients was lower than the controls (P <0.001 and P= 0.01, respectively). Thirty-seven (71.2%) cystic fibrosis patients had serum 25-hydroxyvitamin D level below 15 ng/mL. Bone mineral density of children with cystic fibrosis was significantly lower than controls; majority of them were vitamin-D deficient. Intervening at an early stage of the disease and providing optimal therapy involving simultaneous management of the several factors affecting bone mineral accretion may be beneficial in improving bone health of these patients.

Organic and inorganic molecules as probes of mineral surfaces (Invited)

NASA Astrophysics Data System (ADS)

Sverjensky, D. A.

2010-12-01

Although the multi-site nature of mineral surfaces is to be expected based on the underlying crystal structure, definitive evidence of the need to use more than one site in modelling proton surface charge or adsorption of a single adsorbate at the mineral-water interface is lacking. Instead, a single-site approach affords a practical way of averaging over all possible crystal planes and sites in a powdered mineral sample. Extensive analysis of published proton surface charge and adsorption of metals on oxide mineral surfaces can be undertaken with a single site density for each mineral based on tritium exchange or estimation from averages of the site densities of likely exposed surfaces. Even in systems with competing metals (e.g. Cu and Pb on hematite), the same site density as used for proton surface charge can be employed depending on the reaction stoichiometry. All of this indicates that protons and metals can bind to a great variety of sites with the same overall site density. However, simple oxyanions such as carbonate, sulfate, selenate, arsenate and arsenite require a much lower site density for a given mineral. For example, on goethite these oxyanions utilize a site density that correlates with the BET surface area of the goethite. In this way, the oxyanions can be thought of as selectively probing the available sites on the mineral. The correlation probably arises because goethites with different BET surface areas have different proportions of singly and multiply-bonded oxygens, and only the singly-bonded oxygens are useful for inner-sphere surface complexation by the ligand exchange mechanism. Small organic molecules behave in a remarkably similar way. For example, adsorption of oxalate on goethite, and aspartate, glutamate, dihydroxyphenylalanine, lysine and arginine on rutile are all consistent with a much smaller site density than those required for metals such as calcium or neodymium. Overall, these results suggest that both inorganic oxyanions and organic molecules containing carboxylate functional groups serve as much more sensitive probes of the surface structures of minerals than do protons or metals.

Validity and test–retest reliability of a novel simple back extensor muscle strength test

PubMed Central

Harding, Amy T; Weeks, Benjamin Kurt; Horan, Sean A; Little, Andrew; Watson, Steven L; Beck, Belinda Ruth

2017-01-01

Objectives: To develop and determine convergent validity and reliability of a simple and inexpensive clinical test to quantify back extensor muscle strength. Methods: Two testing sessions were conducted, 7 days apart. Each session involved three trials of standing maximal isometric back extensor muscle strength using both the novel test and isokinetic dynamometry. Lumbar spine bone mineral density was examined by dual-energy X-ray absorptiometry. Validation was examined with Pearson correlations (r). Test–retest reliability was examined with intraclass correlation coefficients and limits of agreement. Pearson correlations and intraclass correlation coefficients are presented with corresponding 95% confidence intervals. Linear regression was used to examine the ability of peak back extensor muscle strength to predict indices of lumbar spine bone mineral density and strength. Results: A total of 52 healthy adults (26 men, 26 women) aged 46.4 ± 20.4 years were recruited from the community. A strong positive relationship was observed between peak back extensor strength from hand-held and isokinetic dynamometry (r = 0.824, p < 0.001). For the novel back extensor strength test, short- and long-term reliability was excellent (intraclass correlation coefficient = 0.983 (95% confidence interval, 0.971–0.990), p < 0.001 and intraclass correlation coefficient = 0.901 (95% confidence interval, 0.833–0.943), p < 0.001, respectively). Limits of agreement for short-term repeated back extensor strength measures with the novel back extensor strength protocol were −6.63 to 7.70 kg, with a mean bias of +0.71 kg. Back extensor strength predicted 11% of variance in lumbar spine bone mineral density (p < 0.05) and 9% of lumbar spine index of bone structural strength (p < 0.05). Conclusion: Our novel hand-held dynamometer method to determine back extensor muscle strength is quick, relatively inexpensive, and reliable; demonstrates initial convergent validity in a healthy population; and is associated with bone mass at a clinically important site. PMID:28255442

Surface chemistry and flotation behavior of monazite, apatite, ilmenite, quartz, rutile, and zircon using octanohydroxamic acid collector

NASA Astrophysics Data System (ADS)

Nduwa Mushidi, Josue

Global increase in rare earth demand and consumption has led to further understanding their beneficiation and recovery. Monazite is the second most important rare earth mineral that can be further exploited. In this study, the surface chemistry of monazite in terms of zeta potential, adsorption density, and flotation response by microflotation using octanohydroxamic acid is determined. Apatite, ilmenite, quartz, rutile, and zircon are minerals that frequently occur with monazite among other minerals. Hence they were chosen as gangue minerals in this study. The Iso Electric Point (IEP) of monazite, apatite, ilmenite, quartz, rutile, and zircon are 5.3, 8.7, 3.8, 3.4, 6.3, and 5.1 respectively. The thermodynamic parameters of adsorption were also evaluated. Ilmenite, rutile and zircon have high driving forces for adsorption with DeltaGads. = 20.48, 22.10, and 22.4 kJ/mol respectively. The free energy of adsorption is 14.87 kJ/mol for monazite. Adsorption density testing shows that octanohydroxamic acid adsorbs on negatively charged surfaces of monazite and its gangue minerals which indicates chemisorption. This observation was further confirmed by microflotation experiments. Increasing the temperature to 80°C raises the adsorption and flotability of monazite and gangue minerals. This does not allow for effective separation. Sodium silicate appeared to be most effective to depress associated gangue minerals. Finally, the fundamentals learned were applied to the flotation of monazite ore from Mt. Weld. However, these results showed no selectivity due to the presence of goethite as fine particles and due to a low degree of liberation of monazite in the ore sample.

Fourier Transform Infrared Imaging Microspectroscopy and Tissue-Level Mechanical Testing Reveal Intraspecies Variation in Mouse Bone Mineral and Matrix Composition

PubMed Central

Courtland, Hayden-William; Nasser, Philip; Goldstone, Andrew B.; Spevak, Lyudmila; Boskey, Adele L.; Jepsen, Karl J.

2009-01-01

Fracture susceptibility is heritable and dependent upon bone morphology and quality. However, studies of bone quality are typically overshadowed by emphasis on bone geometry and bone mineral density. Given that differences in mineral and matrix composition exist in a variety of species, we hypothesized that genetic variation in bone quality and tissue-level mechanical properties would also exist within species. Sixteen-week-old female A/J, C57BL/6J (B6), and C3H/HeJ (C3H) inbred mouse femora were analyzed using Fourier transform infrared imaging and tissue-level mechanical testing for variation in mineral composition, mineral maturity, collagen cross-link ratio, and tissue-level mechanical properties. A/J femora had an increased mineral-to-matrix ratio compared to B6. The C3H mineral-to-matrix ratio was intermediate of A/J and B6. C3H femora had reduced acid phosphate and carbonate levels and an increased collagen cross-link ratio compared to A/J and B6. Modulus values paralleled mineral-to-matrix values, with A/J femora being the most stiff, B6 being the least stiff, and C3H having intermediate stiffness. In addition, work-to-failure varied among the strains, with the highly mineralized and brittle A/J femora performing the least amount of work-to-failure. Inbred mice are therefore able to differentially modulate the composition of their bone mineral and the maturity of their bone matrix in conjunction with tissue-level mechanical properties. These results suggest that specific combinations of bone quality and morphological traits are genetically regulated such that mechanically functional bones can be constructed in different ways. PMID:18855037

Fourier transform infrared imaging microspectroscopy and tissue-level mechanical testing reveal intraspecies variation in mouse bone mineral and matrix composition.

PubMed

Courtland, Hayden-William; Nasser, Philip; Goldstone, Andrew B; Spevak, Lyudmila; Boskey, Adele L; Jepsen, Karl J

2008-11-01

Fracture susceptibility is heritable and dependent upon bone morphology and quality. However, studies of bone quality are typically overshadowed by emphasis on bone geometry and bone mineral density. Given that differences in mineral and matrix composition exist in a variety of species, we hypothesized that genetic variation in bone quality and tissue-level mechanical properties would also exist within species. Sixteen-week-old female A/J, C57BL/6J (B6), and C3H/HeJ (C3H) inbred mouse femora were analyzed using Fourier transform infrared imaging and tissue-level mechanical testing for variation in mineral composition, mineral maturity, collagen cross-link ratio, and tissue-level mechanical properties. A/J femora had an increased mineral-to-matrix ratio compared to B6. The C3H mineral-to-matrix ratio was intermediate of A/J and B6. C3H femora had reduced acid phosphate and carbonate levels and an increased collagen cross-link ratio compared to A/J and B6. Modulus values paralleled mineral-to-matrix values, with A/J femora being the most stiff, B6 being the least stiff, and C3H having intermediate stiffness. In addition, work-to-failure varied among the strains, with the highly mineralized and brittle A/J femora performing the least amount of work-to-failure. Inbred mice are therefore able to differentially modulate the composition of their bone mineral and the maturity of their bone matrix in conjunction with tissue-level mechanical properties. These results suggest that specific combinations of bone quality and morphological traits are genetically regulated such that mechanically functional bones can be constructed in different ways.

Relationship between masticatory function and internal structure of the mandible based on computed tomography findings.

PubMed

Sato, Hidemasa; Kawamura, Akira; Yamaguchi, Masaru; Kasai, Kazutaka

2005-12-01

The purposes of this study were to investigate bone mineral density as a part of bone construction in human skulls and to examine the relationship between dentofacial morphology and masticatory function by using computed tomography (CT) findings. Changes in bone mineral density in the mandible because of loss of masticatory function were tested in rats by experimentally producing an environment that inhibited mastication by the molars. Data for the human study were obtained from 27 modern male Japanese skulls (mean age, 28 years) from the University of Tokyo. Cortical bone thickness (CBT) and CT value (CV) were measured by each CT scan of the first and molars. For the animal study, a metal cap was inserted between the maxillary and mandibular incisors to prevent the molars from biting in 6-week-old male Wistar rats. The rats were killed after 2, 4, or 6 weeks, and bone mineral density was measured in cancellous and cortical bone equivalent to the first molar region by using peripheral quantitative computed tomography. In the human skull study, significant negative correlations were observed between CV in the regions of the buccal side of the second molar and the angle between the Frankfort horizontal and mandibular planes. Significant negative correlations were also observed between the gonial angle and CV in the buccal and basal sides. In the animal study, cancellous bone mineral density began to decline 4 weeks after the start of the experiment in the masticatory hypofunction group compared with the control group. By week 6, cancellous bone density had declined by 11.6% on the buccal side, 16.7% on the lingual side, 12.3% at the bifurcation of the root, and 38.1% at the root apex. Cortical bone density declined by 8% to 12% on the lingual side. The results support our hypothesis that a functional adaptive response by the mandible to mechanical stress resulting from mastication occurs not only in the muscle insertion area, but also in mandibular alveolar bone in the molar region.

Effects of tamoxifen on bone mineral density and metabolism in postmenopausal women with early-stage breast cancer.

PubMed

Zidan, Jamal; Keidar, Zohar; Basher, Walid; Israel, Ora

2004-01-01

At the present time, tamoxifen is the most widely used anti-estrogen for adjuvant therapy and metastatic disease in postmenopausal women with breast cancer, a population at high risk for osteoporosis. This prospective study was designed to evaluate the effect of adjuvant tamoxifen on bone mineral density and all biochemical markers concomitantly in women with early-stage breast cancer in one study. Using dual-energy X-ray absorptiometry, prior to and 12 mo after tamoxifen treatment, bone mineral density in lumbar spine and femoral neck was measured in 44 women with T1-T2N0M0 estrogen-receptor-positive breast cancer receiving adjuvant treatment with tamoxifen 20 mg/d. Biomarkers that can affect bone mineral metabolism were measured before and after 3 and 12 mo of tamoxifen treatment. Bone mineral density was minimally increased in lumbar spine and femoral neck after 12 mo treatment with tamoxifen (p = 0.79 and 0.55, respectively). No differences were found in serum levels of calcium, phosphate, creatinine, ALAT, albumin, LDH, calcitonin, or estradiol. A significant decrease in osteocalcin levels was found after 3 and 12 mo (p < or = 0.01). TSH and PTH levels were increased (p < or = 0.05) after 3 mo, returning to baseline after 12 mo. In conclusion, tamoxifen has an estrogen-like effect on bone metabolism in postmenopausal women and is associated with preservation of bone mineral density in lumbar spine and femoral neck. Changes in serum concentration of biochemical markers may reflect decreased bone turnover or bone remodeling and add to the understanding of tamoxifen's effect on bone mineral density.

BMI, hypertension and low bone mineral density in adult men and women.

PubMed

Szklarska, Alicja; Lipowicz, Anna

2012-08-01

The aim of this work was to estimate the body mass index (BMI) at which risk of hypertension is lowest in men and women, while concurrently considering the protective role of adipose tissue in osteoporosis. Healthy, occupationally active inhabitants of the city of Wrocław, Poland, 1218 women and 434 men were studied. BMI, systolic and diastolic blood pressures, bone mineral density (BMD) of the trabecular compartment and distal radius of the non-dominant hand were recorded. Overweight in young women (≤45 years) was associated with increased risk of hypertension, whereas the risk of low bone mineral was decreased for the same BMI. In older women (>45 years), a BMI>27 was the threshold for increased risk of hypertension. In this age group, extremely slim women (BMI<21) had the highest risk of low bone mineral density. In younger males (≤45 years), risk of hypertension was lowest among the thinnest subjects (BMI<21). Increase in BMI over 21 kg/m(2) increased the risk of hypertension. The probability of low bone mineral density was the same in all BMI categories of men. In older men (>45 years), the thinnest (BMI<21) had higher risk of hypertension. To begin from BMI=25 kg/m(2), there was a monotonous increase in risk of hypertension in men. Higher risk for low bone mineral density was observed in older men with the BMI<23. Among younger adults, risk of hypertension and low bone mineral density increase at BMI≥21 kg/m(2) in men and BMI≥23 kg/m(2) in women. Among older men and women, the BMI threshold was 27 kg/m(2). Copyright © 2012 Elsevier GmbH. All rights reserved.

Pullout strength of cement-augmented and wide-suture transosseous fixation in the greater tuberosity.

PubMed

Shi, Brendan Y; Diaz, Miguel; Belkoff, Stephen M; Srikumaran, Uma

2017-12-01

Obtaining strong fixation in low-density bone is increasingly critical in surgical repair of rotator cuff tears because of the aging population. To evaluate two new methods of improving pullout strength of transosseous rotator cuff repair in low-density bone, we analyzed the effects of 1) using 2-mm suture tape instead of no. 2 suture and 2) augmenting the lateral tunnel with cement. Eleven pairs of osteopenic or osteoporotic cadaveric humeri were identified by dual-energy x-ray absorptiometry. One bone tunnel and one suture were placed in the heads of 22 specimens. Five randomly selected pairs were repaired with no. 2 suture; the other six pairs were repaired with 2-mm suture tape. One side of each pair received lateral tunnel cement augmentation. Specimens were tested to suture pullout. Data were fitted to multivariate models that accounted for bone mineral density and other specimen characteristics. Two specimens were excluded because of knot-slipping during testing. Use of suture tape versus no. 2 suture conferred a 75-N increase (95% CI: 37, 113) in pullout strength (P<0.001). Cement augmentation conferred a 42-N improvement (95% CI: 10, 75; P=0.011). Other significant predictors of pullout strength were age, sex, and bone mineral density. We show two methods of improving the fixation strength of transosseous rotator cuff repairs in low-density bone: using 2-mm suture tape instead of no. 2 suture and augmenting the lateral tunnel with cement. These methods may improve the feasibility of transosseous repairs in an aging patient population. Copyright © 2017 Elsevier Ltd. All rights reserved.

Molar volumes and densities of minerals

USGS Publications Warehouse

Robie, Richard A.; Bethke, Philip M.

1962-01-01

These tables present critically chosen "best values" for the density and molar volume of selected mineral compounds. No attempt was made to be all-inclusive; rather we have tried to present data for chemically and physically well-defined phases for which the molar volume and/or density was knovvn to the order of 0. 2 percent.

Soy isoflavone supplementation and bone mineral density in menopausal women: a 2-y multicenter clinical trial

USDA-ARS?s Scientific Manuscript database

Isoflavones are naturally occurring plant estrogens that are abundant in soy. Although purported to protect against bone loss, the efficacy of soy isoflavone supplementation in the prevention of osteoporosis in postmenopausal women remains controversial. Our aim was to test the effect of soy isoflav...

Effect of rhythmic gymnastics on volumetric bone mineral density and bone geometry in premenarcheal female athletes and controls.

PubMed

Tournis, S; Michopoulou, E; Fatouros, I G; Paspati, I; Michalopoulou, M; Raptou, P; Leontsini, D; Avloniti, A; Krekoukia, M; Zouvelou, V; Galanos, A; Aggelousis, N; Kambas, A; Douroudos, I; Lyritis, G P; Taxildaris, K; Pappaioannou, N

2010-06-01

Weight-bearing exercise during growth exerts positive effects on the skeleton. Our objective was to test the hypothesis that long-term elite rhythmic gymnastics exerts positive effects on volumetric bone mineral density and geometry and to determine whether exercise-induced bone adaptation is associated with increased periosteal bone formation or medullary contraction using tibial peripheral quantitative computed tomography and bone turnover markers. We conducted a cross-sectional study at a tertiary center. We studied 26 elite premenarcheal female rhythmic gymnasts (RG) and 23 female controls, aged 9-13 yr. We measured bone age, volumetric bone mineral density, bone mineral content (BMC), cortical thickness, cortical and trabecular area, and polar stress strength index (SSIp) by peripheral quantitative computed tomography of the left tibia proximal to the distal metaphysis (trabecular) at 14, 38 (cortical), and 66% (muscle mass) from the distal end and bone turnover markers. The two groups were comparable according to height and chronological and bone age. After weight adjustment, cortical BMC, area, and thickness at 38% were significantly higher in RG (P < 0.005-0.001). Periosteal circumference, SSIp, and muscle area were higher in RG (P < 0.01-0.001). Muscle area was significantly associated with cortical BMC, area, and SSIp, whereas years of training showed positive association with cortical BMC, area, and thickness independent of chronological age. RG in premenarcheal girls may induce positive adaptations on the skeleton, especially in cortical bone. Increased duration of exercise is associated with a positive response of bone geometry.

Modified clay minerals efficiency against chemical and biological warfare agents for civil human protection.

PubMed

Plachá, Daniela; Rosenbergová, Kateřina; Slabotínský, Jiří; Kutláková, Kateřina Mamulová; Studentová, Soňa; Martynková, Gražyna Simha

2014-04-30

Sorption efficiencies of modified montmorillonite and vermiculite of their mono ionic Na and organic HDTMA and HDP forms were studied against chemical and biological warfare agents such as yperite and selected bacterial strains. Yperite interactions with modified clay minerals were observed through its capture in low-density polyethylene foil-modified clay composites by measuring yperite gas permeation with using chemical indication and gas chromatography methods. The antibacterial activities of synthetized organoclays were tested against selected Gram-positive and Gram-negative bacterial species in minimum inhibitory concentration tests. The obtained results showed a positive influence of modified clay minerals on the significant yperite breakthrough-time increase. The most effective material was the polyethylene-Na form montmorillonite, while the polyethylene-Na form vermiculite showed the lowest efficiency. With increasing organic cations loading in the interlayer space the montmorillonite efficiency decreased, and in the case of vermiculite an opposite effect was observed. Generally the modified montmorillonites were more effective than modified vermiculites. The HDP cations seem to be more effective compare to the HDTMA. The antibacterial activity tests confirmed efficiency of all organically modified clay minerals against Gram-positive bacteria. The confirmation of antibacterial activity against Y. pestis, plague bacteria, is the most interesting result of this part of the study. Copyright © 2014 Elsevier B.V. All rights reserved.

Detection of changes in bone quality of osteoporotic model induced by sciatic nerve resection by using Raman spectroscopy

NASA Astrophysics Data System (ADS)

Ishimaru, Yasumitsu; Oshima, Yusuke; Imai, Yuuki; Iimura, Tadahiro; Takanezawa, Sota; Hino, Kazunori; Miura, Hiromasa

2018-02-01

To detect the bone quality loss in osteoporosis, we performed Raman spectroscopic analysis of sciatic nerve resection (NX) mice. Eight months after surgery, lower limbs were collected from the mice and fixed with 70% ethanol. Raman spectra of anterior cortical surface of the proximal tibia at 5 points in each bone were measured by RENISHAW inVia Raman Microscope. Excitation wave length was 785 nm. We also performed DXA and micro CT measurement to confirm the bone mineral density and bone microstructure in the osteoporotic model induced by sciatic nerve resection. In the result of Raman spectroscopy, we detected changes of Raman peak intensity ratio in carbonate/phosphate, mineral/combined proline and hydroxyproline and mineral/phenylalanine. In addition, in the result of micro CT, we found significant changes in VOX BV/TV, Trabecular number, thickness, cancellous bone mineral density, cortical thickness and cortical bone mineral density. The results suggest that not only the bone mineral density but also bone quality reduced in the NX mice. We conclude that Raman spectroscopy is a useful for bone quality assessment as a complementary technique for conventional diagnostics.

Collagen and mineral deposition in rabbit cortical bone during maturation and growth: effects on tissue properties.

PubMed

Isaksson, Hanna; Harjula, Terhi; Koistinen, Arto; Iivarinen, Jarkko; Seppänen, Kari; Arokoski, Jari P A; Brama, Pieter A; Jurvelin, Jukka S; Helminen, Heikki J

2010-12-01

We characterized the composition and mechanical properties of cortical bone during maturation and growth and in adult life in the rabbit. We hypothesized that the collagen network develops earlier than the mineralized matrix. Growth was monitored, and the rabbits were euthanized at birth (newborn), and at 1, 3, 6, 9, and 18 months of age. The collagen network was assessed biochemically (collagen content, enzymatic and non-enzymatic cross-links) in specimens from the mid-diaphysis of the tibia and femur and biomechanically (tensile testing) from decalcified whole tibia specimens. The mineralized matrix was analyzed using pQCT and 3-point bend tests from intact femur specimens. The collagen content and the Young's modulus of the collagen matrix increased significantly until the rabbits were 3 months old, and thereafter remained stable. The amount of HP and LP collagen cross-links increased continuously from newborn to 18 months of age, whereas PEN cross-links increased after 6 months of age. Bone mineral density and the Young's modulus of the mineralized bone increased until the rabbits were at least 6 months old. We concluded that substantial changes take place during the normal process of development in both the biochemical and biomechanical properties of rabbit cortical bone. In cortical bone, the collagen network reaches its mature composition and mechanical strength prior to the mineralized matrix. © 2010 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

[Metabolic status and bone mineral density in patients with pseudarthrosis of long bones in hyperhomocysteinemia].

PubMed

Bezsmertnyĭ, Iu O

2013-06-01

In article described research of the metabolic status and bone mineral density in 153 patients with with pseudarthrosis of long bones, in individuals with consolidated fractures and healthy people. The violations of reparative osteogenesis at hyperhomocysteinemia are accompanied by disturbances of the functional state of bone tissue, inhibition of biosynthetic and increased destruction processes, reduced bone mineral density in the formation of osteopenia and osteoporosis. The degree and direction of change of bone depends on the type of violation of reparative osteogenesis.

[Disorder of bone mineral density in patients with the digestive system diseases].

PubMed

Embutnieks, Iu V; Drozdov, V N; Chernyshova, I V; Topcheeva, O N; Koricheva, E S; Albulova, E A

2011-01-01

This article studies the clinical features of the flow of the gastrointestinal tract and liver in the formation of osteopenia and osteoporosis. Were shown the incidence of disorders of bone mineral density in patients with chronic pancreatitis, liver cirrhosis, gallstone disease, inflammatory bowel diseases, and diseases accompanied by syndrome of malabsorption (gluten enteropathy, a syndrome of short small intestine). Were established population (age, sex, lower body mass index, menopause), clinical and laboratory factors indicating high risk of lower bone mineral density in these patients.

Bone mineral loss in young women with amenorrhoea.

PubMed Central

Davies, M C; Hall, M L; Jacobs, H S

1990-01-01

OBJECTIVE--To examine the impact of amenorrhoea on bone mineral density in women of reproductive age. DESIGN--Cross sectional study of 200 amenorrhoeic women compared with normally menstruating controls. SETTING--Teaching hospital outpatient clinic specialising in reproductive medicine. SUBJECTS--200 Women aged 16-40 with a past or current history of amenorrhoea from various causes and of a median duration of three years, and a control group of 57 age matched normal volunteers with no history of menstrual disorder. MAIN OUTCOME MEASURE--Bone mineral density in the lumbar spine (L1-L4) as measured by dual energy x ray absorptiometry. RESULTS--The amenorrhoeic group showed a mean reduction in bone mineral density of 15% (95% confidence interval 12% to 18%) as compared with controls (mean bone mineral density 0.89 (SD 0.12) g/cm2 v 1.05 (0.09) g/cm2 in controls). Bone loss was related to the duration of amenorrhoea and the severity of oestrogen deficiency rather than to the underlying diagnosis. Patients with a history of fracture had significantly lower bone density than those without a history of fracture. Ten patients had suffered an apparently atraumatic fracture. CONCLUSIONS--Amenorrhoea in young women should be investigated and treated to prevent bone mineral loss. Menopausal women with a past history of amenorrhoea should be considered to be at high risk of osteoporosis. PMID:2224267

Cost-minimization study comparing annual infusion of zoledronic acid or weekly oral alendronate in women with low bone mineral density.

PubMed

Chávez-Valencia, Venice; Arce-Salinas, César Alejandro; Espinosa-Ortega, Fabricio

2014-01-01

Cost-minimization study to assess the annual direct costs of 2 antiresorptive strategies in postmenopausal women with low bone mineral densities (BMDs). Patients were randomly assigned to receive 70 mg of oral weekly alendronate or a 1-time 5mg of intravenous zoledronic acid. All medical and nonmedical direct costs were recorded for 1 yr. Student's t-test or the Chi-squared test was used. A total of 101 postmenopausal women were enrolled with a mean age of 58.3 ± 7.6 yr and a postmenopausal period of 13.5 ± 8.3 yr. A total of 50 patients completed 1 yr of alendronate and 51 patients received zoledronic acid. At baseline, no differences were seen between the 2 groups in anthropometric measures, comorbidities, and bone mineral density. The costs for medical attention for low bone mass were $81,532 (US Dollars) for the alendronate group and $69,251 for the zoledronic acid group; the cost per patient was $1631 in the alendronate group vs $1358 in the zoledronic acid group (p<0.0001). Therefore, zoledronic acid treatment provided an annual savings of 15% of the direct costs compared with oral alendronate treatment. Moreover, there was a significant increase in lumbar spine T-scores in the zoledronic acid group when compared with the alendronate group. Annual zoledronic acid infusion as an antiresorptive treatment in women with low BMD provides significant monetary savings when compared with weekly alendronate therapy for 1 yr. Zoledronic acid infusion is also linked to higher increase in BMD and compliance. Copyright © 2014 The International Society for Clinical Densitometry. Published by Elsevier Inc. All rights reserved.

Insufficient stability of pedicle screws in osteoporotic vertebrae: biomechanical correlation of bone mineral density and pedicle screw fixation strength.

PubMed

Weiser, Lukas; Huber, Gerd; Sellenschloh, Kay; Viezens, Lennart; Püschel, Klaus; Morlock, Michael M; Lehmann, Wolfgang

2017-11-01

Loosening of pedicle screws is one major complication of posterior spinal stabilisation, especially in the patients with osteoporosis. Augmentation of pedicle screws with cement or lengthening of the instrumentation is widely used to improve implant stability in these patients. However, it is still unclear from which value of bone mineral density (BMD) the stability of pedicle screws is insufficient and an additional stabilisation should be performed. The aim of this study was to investigate the correlation of bone mineral density and pedicle screw fatigue strength as well as to define a threshold value for BMD below which an additional stabilisation is recommended. Twenty-one human T12 vertebral bodies were collected from donors between 19 and 96 years of age and the BMD was measured using quantitative computed tomography. Each vertebral body was instrumented with one pedicle screw and mounted in a servo-hydraulic testing machine. Fatigue testing was performed by implementing a cranio-caudal sinusoidal, cyclic (0.5 Hz) load with stepwise increasing peak force. A significant correlation between BMD and cycles to failure (r = 0.862, r 2  = 0.743, p < 0.001) as well as for the linearly related fatigue load was found. Specimens with BMD below 80 mg/cm 3 only reached 45% of the cycles to failure and only 60% of the fatigue load compared to the specimens with adequate bone quality (BMD > 120 mg/cm 3 ). There is a close correlation between BMD and pedicle screw stability. If the BMD of the thoracolumbar spine is less than 80 mg/cm 3 , stability of pedicle screws might be insufficient and an additional stabilisation should be considered.

Development and validation of a subject-specific finite element model of the functional spinal unit to predict vertebral strength.

PubMed

Lee, Chu-Hee; Landham, Priyan R; Eastell, Richard; Adams, Michael A; Dolan, Patricia; Yang, Lang

2017-09-01

Finite element models of an isolated vertebral body cannot accurately predict compressive strength of the spinal column because, in life, compressive load is variably distributed across the vertebral body and neural arch. The purpose of this study was to develop and validate a patient-specific finite element model of a functional spinal unit, and then use the model to predict vertebral strength from medical images. A total of 16 cadaveric functional spinal units were scanned and then tested mechanically in bending and compression to generate a vertebral wedge fracture. Before testing, an image processing and finite element analysis framework (SpineVox-Pro), developed previously in MATLAB using ANSYS APDL, was used to generate a subject-specific finite element model with eight-node hexahedral elements. Transversely isotropic linear-elastic material properties were assigned to vertebrae, and simple homogeneous linear-elastic properties were assigned to the intervertebral disc. Forward bending loading conditions were applied to simulate manual handling. Results showed that vertebral strengths measured by experiment were positively correlated with strengths predicted by the functional spinal unit finite element model with von Mises or Drucker-Prager failure criteria ( R 2  = 0.80-0.87), with areal bone mineral density measured by dual-energy X-ray absorptiometry ( R 2  = 0.54) and with volumetric bone mineral density from quantitative computed tomography ( R 2  = 0.79). Large-displacement non-linear analyses on all specimens did not improve predictions. We conclude that subject-specific finite element models of a functional spinal unit have potential to estimate the vertebral strength better than bone mineral density alone.

Follicle-stimulating hormone and bioavailable estradiol are less important than weight and race in determining bone density in younger postmenopausal women

PubMed Central

Preisser, J. S.; Hammett-Stabler, C. A.; Renner, J. B.; Rubin, J.

2011-01-01

Summary The association between follicle-stimulating hormone (FSH) and bone density was tested in 111 postmenopausal women aged 50–64 years. In the multivariable analysis, weight and race were important determinants of bone mineral density. FSH, bioavailable estradiol, and other hormonal variables did not show statistically significant associations with bone density at any site. Introduction FSH has been associated with bone density loss in animal models and longitudinal studies of women. Most of these analyses have not considered the effect of weight or race. Methods We tested the association between FSH and bone density in younger postmenopausal women, adjusting for patient-related factors. In 111 postmenopausal women aged 50–64 years, areal bone mineral density (BMD) was measured at the lumbar spine, femoral neck, total hip, and distal radius using dual-energy X-ray absorptiometry, and volumetric BMD was measured at the distal radius using peripheral quantitative computed tomography (pQCT). Height, weight, osteoporosis risk factors, and serum hormonal factors were assessed. Results FSH inversely correlated with weight, bioavailable estradiol, areal BMD at the lumbar spine and hip, and volumetric BMD at the ultradistal radius. In the multivariable analysis, no hormonal variable showed a statistically significant association with areal BMD at any site. Weight was independently associated with BMD at all central sites (p<0.001), but not with BMD or pQCT measures at the distal radius. Race was independently associated with areal BMD at all sites (p≤0.008) and with cortical area at the 33% distal radius (p=0.004). Conclusions Correlations between FSH and bioavailable estradiol and BMD did not persist after adjustment for weight and race in younger postmenopausal women. Weight and race were more important determinants of bone density and should be included in analyses of hormonal influences on bone. PMID:21125395

Bone mineral density among systemic lupus erythematosus patient age 5-18 years with glucocorticoid treatment in child and adolescent outpatient clinic, Cipto Mangunkusumo Hospital, Jakarta

NASA Astrophysics Data System (ADS)

Indriyani, N.; Tridjaja, B.; Medise, B. E.; Kurniati, N.

2017-08-01

Systemic lupus erythematosus (SLE) is an autoimmune disease affecting children; its morbidity and mortality rates are significant. One risk factor for morbidity is chronic corticosteroid use. The aim of this study is to determine the occurrence rate of low bone mineral density; discuss the characteristics, including cumulative and daily doses of corticosteroid, body mass index, Systemic Lupus Erythematosus Disease Activity Index (SLEDAI), calcium, and vitamin D intake; and assess bone metabolism laboratory parameters, including serum calcium, vitamin D, alkaline phosphatase (ALP), phosphorus, and cortisol among children with SLE receiving corticosteroids. This was a descriptive, cross-sectional study involving 16 children with SLE attending the child and adolescent outpatient clinic at Cipto Mangunkusumo Hospital in November-December 2016. Low bone mineral density occurred among 7/16 patients. The mean total bone mineral density was 0.885 ± 0.09 g/cm2. Children with SLE receiving corticosteroid had low calcium (8.69 ± 0.50 mg/dl), vitamin D (19.3 ± 5.4 mg/dl), ALP (79.50 [43.00-164.00] U/l), and morning cortisol level (1.20 [0.0-10.21] ug/dl), as well as calcium (587.58 ± 213.29 mg/d) and vitamin D (2.9 [0-31.8] mcg/d) intake. The occurrence of low bone mineral density was observed among children with SLE receiving corticosteroid treatment. Low bone mineral density tends to occur among patients with higher cumulative doses and longer duration of corticosteroid treatments.

Bone mineral density trends in Indian patients with hyperthyroidism--effect of antithyroid therapy.

PubMed

Dhanwal, Dinesh Kumar; Gupta, Nandita

2011-09-01

Hyperthyroidism is associated with bone loss, which is reversible after treatment. The extent of reversibility of loss of bone mass density (BMD) in hyperthyroid patients after treatment especially at forearm is not clear. Therefore, the present study was conducted to assess degree of reversibility in bone mineral density following one-year medical treatment in Indian patients with hyperthyroidism. A total of 30 consecutive patients with hyperthyroidism were included in this one year study at All India Institute of Medical Sciences, New Delhi, India. All the patients were assessed for parameters of bone mineral homeostasis such as calcium, phosphorous, alkaline phosphatase, 25-hydroxy vitamin D [25 (OH) D], parathyroid hormone (PTH) at the time of diagnosis and after one year medical treatment. Bone mineral density was measured using Hologic DXA scan at hip, spine and forearm. All the patients received medical therapy with carbimazole. The parameters of bone homeostasis and bone mineral density at base line and after one year medical treatment was compared. All patients attained euthyroid status after eight weeks of carbimazole therapy. Parameters of bone homeostasis such as calcium, phosphorous, 25 (OH) D and PTH did not show any significant change from base line. Bone mineral density expressed as bone mineral content in gm/cm2 at left hip neck, trochanteric and intertrochanteric region was significantly higher after carbimazole therapy (745.2 +/- 127.6 gm/cm2 vs. 688.2 +/- 123.5 gm/cm2; p = 0.02, 573.4 +/- 109.9 gm/cm2 vs. 641.0 +/- 138.0 gm/cm2, p = 0.005 and 1008.6 +/- 185.5 gm/cm2 vs. 938.0 +/- 145.3 gm/cm2 p = 0.0131 respectively). Bone mineral density at lumbar spine expressed as either T and Z score was significantly higher after treatment (10 months of euthyroid state) (-0.6 +/- 1.3 vs. -1.7 +/- 1.2, p = 0.013 and -0.4 +/- 1.2 vs. -1.4 +/- 1.2, p = 0.012 respectively). However Bone mineral measures as T and Z score at left forearm decreased significantly after one year of medical therapy. In Indian patients with hyperthyroidism, the pattern of recovery of bone loss after one year of antithyroid therapy suggests early recovery at hip and lumbar spine and deterioration at forearm.

Different Indices of Fetal Growth Predict Bone Size and Volumetric Density at 4 Years of Age

PubMed Central

Harvey, Nicholas C; Mahon, Pamela A; Robinson, Sian M; Nisbet, Corrine E; Javaid, M Kassim; Crozier, Sarah R; Inskip, Hazel M; Godfrey, Keith M; Arden, Nigel K; Dennison, Elaine M; Cooper, Cyrus

2011-01-01

We have demonstrated previously that higher birth weight is associated with greater peak and later-life bone mineral content and that maternal body build, diet, and lifestyle influence prenatal bone mineral accrual. To examine prenatal influences on bone health further, we related ultrasound measures of fetal growth to childhood bone size and density. We derived Z-scores for fetal femur length and abdominal circumference and conditional growth velocity from 19 to 34 weeks’ gestation from ultrasound measurements in participants in the Southampton Women’s Survey. A total of 380 of the offspring underwent dual-energy X-ray absorptiometry (DXA) at age 4 years [whole body minus head bone area (BA), bone mineral content (BMC), areal bone mineral density (aBMD), and estimated volumetric BMD (vBMD)]. Volumetric bone mineral density was estimated using BMC adjusted for BA, height, and weight. A higher velocity of 19- to 34-week fetal femur growth was strongly associated with greater childhood skeletal size (BA: r = 0.30, p < .0001) but not with volumetric density (vBMD: r = 0.03, p = .51). Conversely, a higher velocity of 19- to 34-week fetal abdominal growth was associated with greater childhood volumetric density (vBMD: r = 0.15, p = .004) but not with skeletal size (BA: r = 0.06, p = .21). Both fetal measurements were positively associated with BMC and aBMD, indices influenced by both size and density. The velocity of fetal femur length growth from 19 to 34 weeks’ gestation predicted childhood skeletal size at age 4 years, whereas the velocity of abdominal growth (a measure of liver volume and adiposity) predicted volumetric density. These results suggest a discordance between influences on skeletal size and volumetric density. PMID:20437610

Characterisation of osteoprotegerin autoantibodies in coeliac disease.

PubMed

Real, Ana; Gilbert, Nick; Hauser, Barbara; Kennedy, Nick; Shand, Alan; Gillett, Helen; Gillett, Peter; Goddard, Clive; Cebolla, Ángel; Sousa, Carolina; Fraser, William D; Satsangi, Jack; Ralston, Stuart H; Riches, Philip L

2015-08-01

Autoantibodies neutralising the effect of the bone regulatory cytokine osteoprotegerin (OPG) have been described in a patient with severe osteoporosis and coeliac disease. This study aimed to determine the prevalence and epitope specificity of autoantibodies to OPG in patients with coeliac disease, and correlate their presence with bone mineral density. A direct enzyme-linked immunosorbent assay was developed and used to screen patients with coeliac disease for autoantibodies to OPG. Recombinant fragments of OPG were made to evaluate the epitope specificity and affinity of these antibodies. Phenotype information of the patients was obtained by case note review. Raised titres of antibodies to OPG were found in 7/71 (9.8 %) patients with coeliac disease, compared with 1/72 (1.4 %) non-coeliac osteoporosis clinic control patients (p < 0.05). Our results suggest that a polyclonal antibody response to OPG is raised in these patients capable of recognising different epitopes of OPG with varying affinity. The titre of OPG antibodies was associated with lower bone mineral density Z-score of the hip in coeliac patients on univariate (p < 0.05) and multivariate analysis including age, sex height and weight as covariates (p < 0.01). Polyclonal antibodies to OPG are more common in patients with coeliac disease and are independently associated with lower bone mineral density Z-scores of the hip. Further work is required to establish the clinical utility of testing for OPG antibodies.

Osteoporosis: Are we measuring what we intend to measure? In search of the ideal bone strength study

NASA Astrophysics Data System (ADS)

de Riese, Cornelia

2006-02-01

In 1991 the World Health Organization (WHO) defined osteoporosis as a "loss of bone mass and micro architectural deterioration of the skeleton leading to increased risk of fracture." 1,2 Since microarchitecture can not be measured directly, a panel of the WHO recommended that the diagnosis be made according to a quantifiable surrogate marker, calcium mineral, in bone. Subsequently in 1994, the definition focused on the actual bone "density," giving densitometric technology a central place in establishing the diagnosis of osteoporosis. 3,4 But soon it became obvious that there was only limited correlation between bone mineral density (BMD) and actual occurrence of fractures and that decreases in bone mass account for only about 50% of the deterioration of bone strength with aging. In other words only about 60% of bone strength is related to BMD. 5 Recent developments in bone research have shown that bone mineral density in itself is not sufficient to accurately predict fracture risk. Bone is composed of inorganic calcium apatite crystals that mineralize an organic type I collagen matrix. The degree of mineralization, the properties of the collagen matrix, crystal size, trabecular orientation, special distribution of the different components and many more factors are all impacting bone strength. 6-14 Human cadaver studies have confirmed the correlation between bone density and bone. 26 strength. 5,15-20 Changes in cancellous bone morphology appear to lead to a disproportionate decrease in bone strength. 21-26 When postmenopausal women are stratified by age, obvious differences between BMD and actual fracture risk are observed. 24 Felsenberg eloquently summarizes what he calls the "Bone Quality Framework." In great detail he talks about the geometry and micro- architecture of bone and how the different components are related to functional stability. 27 Are our current testing modalities appropriately addressing these structural factors? Are we keeping in mind that in screening for osteoporosis the key variable is fragility, not bone density itself? All currently FDA approved and commercially available equipments for the evaluation of bone status claim that they - at least indirectly - assess the biological fracture risk. This review summarizes an extensive current literature research covering FDA approved as well as experimental devices for the evaluation of bone. The pros and cons of the different techniques are discussed in the context of diagnostic accuracies and practical implications.

Localized tissue mineralization regulated by bone remodelling: A computational approach

PubMed Central

Decco, Oscar; Adams, George; Cook, Richard B.; García Aznar, José Manuel

2017-01-01

Bone is a living tissue whose main mechanical function is to provide stiffness, strength and protection to the body. Both stiffness and strength depend on the mineralization of the organic matrix, which is constantly being remodelled by the coordinated action of the bone multicellular units (BMUs). Due to the dynamics of both remodelling and mineralization, each sample of bone is composed of structural units (osteons in cortical and packets in cancellous bone) created at different times, therefore presenting different levels of mineral content. In this work, a computational model is used to understand the feedback between the remodelling and the mineralization processes under different load conditions and bone porosities. This model considers that osteoclasts primarily resorb those parts of bone closer to the surface, which are younger and less mineralized than older inner ones. Under equilibrium loads, results show that bone volumes with both the highest and the lowest levels of porosity (cancellous and cortical respectively) tend to develop higher levels of mineral content compared to volumes with intermediate porosity, thus presenting higher material densities. In good agreement with recent experimental measurements, a boomerang-like pattern emerges when plotting apparent density at the tissue level versus material density at the bone material level. Overload and disuse states are studied too, resulting in a translation of the apparent–material density curve. Numerical results are discussed pointing to potential clinical applications. PMID:28306746

Correlation of quantitative computed tomographic subchondral bone density and ash density in horses.

PubMed

Drum, M G; Les, C M; Park, R D; Norrdin, R W; McIlwraith, C W; Kawcak, C E

2009-02-01

The purpose of this study was to compare subchondral bone density obtained using quantitative computed tomography with ash density values from intact equine joints, and to determine if there are measurable anatomic variations in mean subchondral bone density. Five adult equine metacarpophalangeal joints were scanned with computed tomography (CT), disarticulated, and four 1-cm(3) regions of interest (ROI) cut from the distal third metacarpal bone. Bone cubes were ashed, and percent mineralization and ash density were recorded. Three-dimensional models were created of the distal third metacarpal bone from CT images. Four ROIs were measured on the distal aspect of the third metacarpal bone at axial and abaxial sites of the medial and lateral condyles for correlation with ash samples. Overall correlations of mean quantitative CT (QCT) density with ash density (r=0.82) and percent mineralization (r=0.93) were strong. There were significant differences between abaxial and axial ROIs for mean QCT density, percent bone mineralization and ash density (p<0.05). QCT appears to be a good measure of bone density in equine subchondral bone. Additionally, differences existed between axial and abaxial subchondral bone density in the equine distal third metacarpal bone.

Association of unipedal standing time and bone mineral density in community-dwelling Japanese women.

PubMed

Sakai, A; Toba, N; Takeda, M; Suzuki, M; Abe, Y; Aoyagi, K; Nakamura, T

2009-05-01

Bone mineral density (BMD) and physical performance of the lower extremities decrease with age. In community-dwelling Japanese women, unipedal standing time, timed up and go test, and age are associated with BMD while in women aged 70 years and over, unipedal standing time is associated with BMD. The aim of this study was to clarify whether unipedal standing time is significantly associated with BMD in community-dwelling women. The subjects were 90 community-dwelling Japanese women aged 54.7 years. BMD of the second metacarpal bone was measured by computed X-ray densitometry. We measured unipedal standing time as well as timed up and go test to assess physical performance of the lower extremities. Unipedal standing time decreased with increased age. Timed up and go test significantly correlated with age. Low BMD was significantly associated with old age, short unipedal standing time, and long timed up and go test. Stepwise regression analysis revealed that age, unipedal standing time, and timed up and go test were significant factors associated with BMD. In 21 participants aged 70 years and over, body weight and unipedal standing time, but not age, were significantly associated with BMD. BMD and physical performance of the lower extremities decrease with older age. Unipedal standing time, timed up and go test, and age are associated with BMD in community-dwelling Japanese women. In women aged 70 years and over, unipedal standing time is significantly associated with BMD.

Calcaneal bone mineral density and mechanical strength of the metatarsals.

PubMed

Lidtke, R H; Patel, D; Muehleman, C

2000-10-01

The primary aim of this study was to determine the predictive value of the bone mineral density of the calcaneus for fracture of the metatarsals. The authors report a strong positive correlation between the bone mineral density of the calcaneus and the four-point bending strength of each of the five metatarsals (r2 = 0.76, 0.64, 0.70, 0.68, and 0.78 for metatarsals 1 through 5, respectively). In addition, the relative strengths of the metatarsals and the correlation with their in vivo loads during gait as previously reported in the literature are discussed.

Liver Enzymes and Bone Mineral Density in the General Population.

PubMed

Breitling, Lutz Philipp

2015-10-01

Liver enzyme serum levels within and just above the normal range are strong predictors of incident morbidity and mortality in the general population. However, despite the close links between hepatic pathology and impaired bone health, the association of liver enzymes with osteoporosis has hardly been investigated. The aim of the present study was to clarify whether serum liver enzyme levels in the general population are associated with bone mineral density. This was an observational, cross-sectional study. Participants and Main Outcome: Data on 13 849 adult participants of the Third National Health and Nutrition Examination Survey were used to quantify the independent associations of γ-glutamyltransferase, alanine transaminase, and aspartate transaminase with femoral neck bone mineral density assessed by dual-energy x-ray absorptiometry. In multiple regression models adjusting for numerous confounding variables, γ-glutamyltransferase showed a weak inverse association with bone mineral density (P = .0063). There also was limited evidence of a nonmonotonous relationship with alanine transaminase, with peak bone mineral density in the second quartile of enzyme activity (P = .0039). No association was found for aspartate transaminase. Although mechanistically plausible associations were found in the present study, the rather weak nature of these patterns renders it unlikely that liver enzyme levels could be of substantial use for osteoporosis risk stratification in the general population.

Serum leptin, bone mineral density and the healing of long bone fractures in men with spinal cord injury.

PubMed

Wang, Lei; Liu, Linjuan; Pan, Zhanpeng; Zeng, Yanjun

2015-11-16

Previously reported fracture rates in patients with spinal cord injury range from 1% to 20%. However, the exact role of spinal cord injury in bone metabolism has not yet been clarified. In order to investigate the effects of serum leptin and bone mineral density on the healing of long bone fractures in men with spinal cord injury, 15 male SCI patients and 15 matched controls were involved in our study. The outcome indicated that at 4 and 8 weeks after bone fracture, callus production in patients with spinal cord injury was lower than that in controls. Besides, bone mineral density was significantly reduced at 2, 4 and 8 weeks. In addition, it was found that at each time point, patients with spinal cord injury had significantly higher serum leptin levels than controls and no association was found between serum leptin level and bone mineral density of lumbar vertebrae. Moreover, bone mineral density was positively correlated with bone formation in both of the groups. These findings suggest that in early phases i.e. week 4 and 8, fracture healing was impaired in patients with spinal cord injury and that various factors participated in the complicated healing process, such as hormonal and mechanical factors.

Bone microarchitecture is more severely affected in patients on hemodialysis than in those receiving peritoneal dialysis.

PubMed

Pelletier, Solenne; Vilayphiou, Nicolas; Boutroy, Stéphanie; Bacchetta, Justine; Sornay-Rendu, Elisabeth; Szulc, Pawel; Arkouche, Walid; Guebre-Egziabher, Fitsum; Fouque, Denis; Chapurlat, Roland

2012-09-01

We used high-resolution quantitative computed tomography to study the microarchitecture of bone in patients with chronic kidney disease on dialysis. We compared bone characteristics in 56 maintenance hemodialysis (21 women, 14 post-menopausal) and 23 peritoneal dialysis patients (9 women, 6 post-menopausal) to 79 healthy men and women from two cohorts matched for age, body mass index, gender, and menopausal status. All underwent dual-energy X-ray absorptiometry of the spine and hip to measure areal bone mineral density, and high-resolution peripheral quantitative computed tomography of the radius and tibia to measure volumetric bone mineral density and microarchitecture. When compared to their matched healthy controls, patients receiving hemodialysis and peritoneal dialysis had a significantly lower areal bone mineral density in the hip. Hemodialysis patients had significantly lower total, cortical, and trabecular volumetric bone mineral density at both sites. Hemodialysis patients had significantly lower trabecular volumetric bone mineral density and microarchitecture at the tibia than the peritoneal dialysis patients. Overall, peritoneal dialysis patients were less affected, their cortical thickness at the distal tibia being the only significant difference versus controls. Thus, we found more severe trabecular damage at the weight-bearing tibia in hemodialysis compared to peritoneal dialysis patients, but this latter finding needs confirmation in larger cohorts.

The Soy Isoflavones to Reduce Bone Loss (SIRBL) Study: Three Year Effects on pQCT Bone Mineral Density and Strength Measures in Postmenopausal Women

USDA-ARS?s Scientific Manuscript database

Soy isoflavones exert inconsistent bone density preserving effects, but the bone strength preserving effects in humans are unknown. Our double-blind randomized controlled trial examined 2 soy isoflavone doses (80 or 120 mg/d) vs placebo tablets on volumetric bone mineral density (vBMD) and strength ...

Menstrual state and exercise as determinants of spinal trabecular bone density in female athletes.

PubMed Central

Wolman, R L; Clark, P; McNally, E; Harries, M; Reeve, J

1990-01-01

OBJECTIVE--To study the effects of amenorrhoea and intensive back exercise on the bone mineral density of the lumbar spine in female athletes. DESIGN--Cross sectional study comparing amenorrhoeic with eumenorrhoeic athletes and rowers with non-rowers. SETTING--The British Olympic Medical Centre, Northwick Park Hospital. PATIENTS--46 Elite female athletes comprising 19 rowers, 18 runners, and nine dancers, of whom 25 were amenorrhoeic and 21 eumenorrhoeic. MAIN OUTCOME MEASURE--Trabecular bone mineral density of the lumbar spine measured by computed tomography. RESULTS--Mean trabecular bone mineral density was 42 mg/cm3 (95% confidence interval 22 to 62 mg/cm3) lower in the amenorrhoeic than the eumenorrhoeic athletes; this difference was highly significant (p = 0.0002). Mean trabecular bone mineral density was 21 mg/cm3 (1 to 41 mg/cm3) lower in the non-rowers than the rowers; this was also significant (p = 0.05). There was no interaction between these two effects (p = 0.28). CONCLUSION--The effect of intensive exercise on the lumbar spine partially compensates for the adverse effect of amenorrhoea on spinal trabecular bone density. Images p516-a PMID:2207417

Regional distribution of mineral and matrix in the femurs of rats flown on Cosmos 1887 biosatellite

NASA Technical Reports Server (NTRS)

Mechanic, Gerald L.; Arnaud, Sara B.; Boyde, Alan; Bromage, Timothy G.; Buckendahl, Patricia

1990-01-01

The location and nature of the defect in mineralization known to occur in growing animals after spaceflight are studied. The distribution of bone mineral density in situ is mapped, and these images are correlated with the chemical composition of the diaphyseal bone. Concentrations of mineral and osteocalcin are found to be low in the distal half of the diaphysis and concentrations of collagen to be low with evidence of increased synthesis in the proximal half of the diaphysis of the flight bones. X-ray microtomography indicates a longitudinal gradient of decreasing mineralization toward the distal diaphysis. Analysis of embedded sections by backscattered electrons reveals patterns of mineral distribution in the proximal, central, and distal regions of the diaphysis and also shows a net reduction in mineral levels toward the distal shaft. Increases in mineral density to higher fractions in controls are less in the flight bones at all three levels.

Influence of Long-Term Fertilization on Spore Density and Colonization of Arbuscular Mycorrhizal Fungi in a Brown Soil

NASA Astrophysics Data System (ADS)

Li, Dongdong; Luo, Peiyu; Yang, Jinfeng

2017-12-01

This study aims to explore changes of long-term fertilization on spore density and colonization of AMF (Arbuscular mycorrhizal fungi) under a 38-y long-term fertilization in a brown soil. Soil samples (0-20 cm,20-40cm,40-60cm)were taken from the six treatments of the long-term fertilization trial in October 2016:no fertilizer (CK), N1(mineral nitrogen fertilizer), N1P (mineral nitrogen and phosphate fertilizer), N1PK (mineral nitrogen, phosphate and potassic fertilizer), pig manure (M2), M2N1P (pig manure, mineral nitrogen andphosphate fertilizer).Spores were isolated from soils by wet sieving and sucrose density gradient centrifugation; mycorrhizal colonization levels were determined by the gridline intersect. The spore density was highest in the topsoils (0-20 cm), and was decreased with increasing of soil depth in each treatment. The spores density of M2N1P treatment was significantly higher than that of other treatments in each soil layer. Application of inorganic fertilizer (especially inorganic with organic fertilizer) can greatly improve the level of colonization. Our results suggested that long-term fertilization significantly affects spore density and colonization of AMF, however, spore density is not related to colonization rate.

Association of ACTN3 polymorphisms with BMD, and physical fitness of elderly women.

PubMed

Min, Seok-Ki; Lim, Seung-Taek; Kim, Chang-Sun

2016-10-01

[Purpose] Association of ACTN3 polymorphism with bone mineral density and the physical fitness of elderly women is still unclear. Therefore, this study investigated the association between ACTN3 genotype and bone mineral density, and the physical fitness of elderly women. [Subjects and Methods] Sixty-eight elderly women (67.38 ± 3.68 years) were recruited at a Seongbuk-Gu (Seoul, Korea) Medical Service Public Health Center. Measurements of physical fitness included muscle strength, muscle endurance, flexibility, agility, balance and VO 2 max. Bone mineral density (BMD), upper limb muscle mass, lower limb muscle mass, percent body fat and body fat mass for the entire body were measured by dual-energy X-ray absorptiometry and an analyzer. Genotyping for the ACTN3 R577X (rs1815739) polymorphism was performed using the TaqMan approach. [Results] ACTN3 gene distribution of subjects were in the Hardy-Weinberg equilibrium (p=0.694). The relative bone mineral density trunk, pelvis and spine differed significantly among the ACTN3 genotypes. There were no significant differences among bone mineral densities of the head, arms, legs, ribs and total, but the RR genotype tended to be higher than other genotypes. Physical fitness was not significantly different among the ACTN3 genotypes. [Conclusion] These results suggest that ACTN3 gene polymorphisms could be used as one of the genetic determinants of bone mass in elderly women, and in particular, they indicate that individuals with the RR genotype have higher BMD and bone mineral composition.

Effects of cast-mediated immobilization on bone mineral mass at various sites in adolescents with lower-extremity fracture.

PubMed

Ceroni, Dimitri; Martin, Xavier; Delhumeau, Cécile; Rizzoli, René; Kaelin, André; Farpour-Lambert, Nathalie

2012-02-01

Leg or ankle fractures occur commonly in the pediatric population and are primarily treated with closed reduction and cast immobilization. The most predictable consequences of immobilization and subsequent weight-bearing restriction are loss of bone mineral mass, substantial muscle atrophy, and functional limitations. The purposes of this study were to determine if lower-limb fractures in adolescents are associated with abnormal bone mineral density or content at the time of fracture, and to quantify bone mineral loss at various sites due to cast-mediated immobilization and limited weight-bearing. We recruited fifty adolescents aged ten to sixteen years who had undergone cast immobilization for a leg or ankle fracture. Dual x-ray absorptiometry scans of the total body, lumbar spine, hip, leg, and calcaneus were performed at the time of fracture and at cast removal. Patients with a fracture were paired with healthy controls according to sex and age. Values at baseline and at cast removal, or at equivalent time intervals in the control group, were compared between groups and between the injured and uninjured legs of the adolescents with the fracture. At the time of fracture, there were no observed differences in the bone mineral density or bone mineral content Z-scores of the total body or the lumbar spine, or in the bone mineral density Z-scores of the calcaneus, between the injured and healthy subjects. At cast removal, bone mineral parameters on the injured side were significantly lower than those on the uninjured side in the injured group. Differences ranged from -5.8% to -31.7% for bone mineral density and from -5.2% to -19.4% for bone mineral content. During the cast period, the injured adolescents had a significant decrease of bone mineral density at the hip, greater trochanter, calcaneus, and total lower limb as compared with the healthy controls. Lower-limb fractures are not related to osteopenia in adolescents at the time of fracture. However, osteopenia does develop in the injured limb during cast immobilization for fracture treatment. Further investigation is required to determine if the bone mineral mass will return to normal or if a permanent decrease is to be expected, which may constitute a hypothetical risk of sustaining a second fracture.

Radiographic comparison of different concentrations of recombinant human bone morphogenetic protein with allogenic bone compared with the use of 100% mineralized cancellous bone allograft in maxillary sinus grafting.

PubMed

Froum, Stuart J; Wallace, Stephen; Cho, Sang-Choon; Khouly, Ismael; Rosenberg, Edwin; Corby, Patricia; Froum, Scott; Mascarenhas, Patrick; Tarnow, Dennis P

2014-01-01

The purpose of this study was to radiographically evaluate, then analyze, bone height, volume, and density with reference to percentage of vital bone after maxillary sinuses were grafted using two different doses of recombinant human bone morphogenetic protein 2/acellular collagen sponge (rhBMP-2/ACS) combined with mineralized cancellous bone allograft (MCBA) and a control sinus grafted with MCBA only. A total of 18 patients (36 sinuses) were used for analysis of height and volume measurements, having two of three graft combinations (one in each sinus): (1) control, MCBA only; (2) test 1, MCBA + 5.6 mL of rhBMP-2/ACS (containing 8.4 mg of rhBMP-2); and (3) test 2, MCBA + 2.8 mL of rhBMP-2/ACS (containing 4.2 mg of rhBMP-2). The study was completed with 16 patients who also had bilateral cores removed 6 to 9 months following sinus augmentation. A computer software system was used to evaluate 36 computed tomography scans. Two time points where selected for measurements of height: The results indicated that height of the grafted sinus was significantly greater in the treatment groups compared with the control. However, by the second time point, there were no statistically significant differences. Three weeks post-surgery bone volume measurements showed similar statistically significant differences between test and controls. However, prior to core removal, test group 1 with the greater dose of rhBMP-2 showed a statistically significant greater increase compared with test group 2 and the control. There was no statistically significant difference between the latter two groups. All three groups had similar volume and shrinkage. Density measurements varied from the above results, with the control showing statistically significant greater density at both time points. By contrast, the density increase over time in both rhBMP groups was similar and statistically higher than in the control group. There were strong associations between height and volume in all groups and between volume and new vital bone only in the control group. There were no statistically significant relationships observed between height and bone density or between volume and bone density for any parameter measured. More cases and monitoring of the future survival of implants placed in these augmented sinuses are needed to verify these results.

Rowing performance, body composition, and bone mineral density outcomes in college-level rowers after a season of concurrent training.

PubMed

Young, Kaelin C; Kendall, Kristina L; Patterson, Kaitlyn M; Pandya, Priyanka D; Fairman, Ciaran M; Smith, Samuel W

2014-11-01

To assess changes in body composition, lumbar-spine bone mineral density (BMD), and rowing performance in college-level rowers over a competition season. Eleven Division I college rowers (mean ± SD 21.4 ± 3.7 y) completed 6 testing sessions throughout the course of their competition season. Testing included measurements of fat mass, bone-free lean mass (BFLM), body fat (%BF), lumbar-spine BMD, and 2000-m time-trial performance. After preseason testing, rowers participated in a periodized training program, with the addition of resistance training to the traditional aerobic-training program. Significant (P < .05) improvements in %BF, total mass, and BFLM were observed at midseason and postseason compared with preseason. Neither lumbar-spine BMD nor BMC significantly changed over the competitive season (P > .05). Finally, rowing performance (as measured by 2000-m time and average watts achieved) significantly improved at midseason and postseason compared with preseason. Our results highlight the efficacy of a seasonal concurrent training program serving to improve body composition and rowing performance, as measured by 2000-m times and average watts, among college-level rowers. Our findings offer practical applications for coaches and athletes looking to design a concurrent strength and aerobic training program to improve rowing performance across a season.

Determination of mechanical stiffness of bone by pQCT measurements: correlation with non-destructive mechanical four-point bending test data.

PubMed

Martin, Daniel E; Severns, Anne E; Kabo, J M J Michael

2004-08-01

Mechanical tests of bone provide valuable information about material and structural properties important for understanding bone pathology in both clinical and research settings, but no previous studies have produced applicable non-invasive, quantitative estimates of bending stiffness. The goal of this study was to evaluate the effectiveness of using peripheral quantitative computed tomography (pQCT) data to accurately compute the bending stiffness of bone. Normal rabbit humeri (N=8) were scanned at their mid-diaphyses using pQCT. The average bone mineral densities and the cross-sectional moments of inertia were computed from the pQCT cross-sections. Bending stiffness was determined as a function of the elastic modulus of compact bone (based on the local bone mineral density), cross-sectional moment of inertia, and simulated quasistatic strain rate. The actual bending stiffness of the bones was determined using four-point bending tests. Comparison of the bending stiffness estimated from the pQCT data and the mechanical bending stiffness revealed excellent correlation (R2=0.96). The bending stiffness from the pQCT data was on average 103% of that obtained from the four-point bending tests. The results indicate that pQCT data can be used to accurately determine the bending stiffness of normal bone. Possible applications include temporal quantification of fracture healing and risk management of osteoporosis or other bone pathologies.

Vitamin K2 improves femoral bone strength without altering bone mineral density in gastrectomized rats.

PubMed

Iwamoto, Jun; Sato, Yoshihiro; Matsumoto, Hideo

2014-01-01

Gastrectomy (GX) induces osteopenia in rats. The present study examined the skeletal effects of vitamin K2 in GX rats. Thirty male Sprague-Dawley rats (12 wk old) were randomized by the stratified weight method into the following three groups of 10 animals each: sham operation (control) group; GX group; and GX+oral vitamin K2 (menatetrenone, 30 mg/kg, 5 d/wk) group. Treatment was initiated at 1 wk after surgery. After 6 wk of treatment, the bone mineral content (BMC), bone mineral density (BMD), and mechanical strength of the femoral diaphysis and distal metaphysis were determined by peripheral quantitative computed tomography and mechanical strength tests, respectively. GX induced decreases in the BMC, BMD, and ultimate force of the femoral diaphysis and distal metaphysis. Vitamin K2 did not significantly influence the BMC or BMD of the femoral diaphysis or distal metaphysis in GX rats, but attenuated the decrease in the ultimate force and increased the stiffness of the femoral diaphysis. The present study showed that administration of vitamin K2 to GX rats improved the bone strength of the femoral diaphysis without altering the BMC or BMD, suggesting effects of vitamin K2 on the cortical bone quality.

Systematic strength training as a model of therapeutic intervention. A controlled trial in postmenopausal women with osteopenia.

PubMed

Hartard, M; Haber, P; Ilieva, D; Preisinger, E; Seidl, G; Huber, J

1996-01-01

Physical exercise is often recommended as a therapeutic tool to combat pre- and postmenopausal loss of bone density. However, the relationship between training dosage (intensity, duration, frequency) and the effect on bone density still is undergoing discussion. Furthermore, the exercise quantification programs are often described so inadequately that they are neither quantitatively nor qualitatively reproducible. The aim of this investigation was to determine whether a clearly defined training of muscle strength, under defined safety aspects, performed only twice weekly, can counteract bone density loss in women with postmenopausal osteopenia. Data from 16 women in the training group (age, 63.6 +/- 6.2 yr) and 15 women in the control group (age, 67.4 +/-9.7 yr), of comparable height and weight, were evaluated. Strength training was performed for 6 mo as continually adapted strength training, providing an intensity of about 70% of each test person's one repetition maximum. Bone mineral density of lumbar vertebrae 2 to 4 and the femoral neck was measured by dual-energy x-ray absorptiometry. Maximum performance in watts and parameters of hemodynamics were controlled with a bicycle ergometer test to maximal effort. In addition, metabolic data were assessed. In the lumbar spine and femoral neck, the training group showed no significant changes, whereas the control group demonstrated a significant loss of bone mineral density, especially in the femoral neck (P<0.05). The strength increase was highly significant in all exercised muscle groups, rising to about 70% above the pretraining status (P<0.001). Heart rate and blood pressure data indicated a slight economization, metabolism was not significantly influenced. Based on these findings, we conclude that continually adapted strength training is an effective, safe, reproducible, and adaptable method of therapeutic strength training, following only two exercise sessions per week.

Preservation of bone structure and function by Lithothamnion sp. – derived minerals

PubMed Central

Aslam, Muhammad Nadeem; Bergin, Ingrid; Jepsen, Karl; Kreider, Jaclynn M.; Graf, Kristin H.; Naik, Madhav; Goldstein, Steven A.; Varani, James

2013-01-01

Progressive bone mineral loss and increasing bone fragility are hallmarks of osteoporosis. A combination of minerals isolated from the red marine algae, Lithothamnion sp. was examined for ability to inhibit bone mineral loss in female mice maintained on either a standard rodent chow (control) diet or a high-fat western diet (HFWD) for 5-, 12- and 18-months. At each time-point, femora were subjected to μ-CT analysis and biomechanical testing. A subset of caudal vertebrae was also analyzed. Following this, individual elements were assessed in bones. Serum levels of the 5b isoform of tartrate-resistant acid phosphatase (TRAP) and procollagen type I propeptide (P1NP) were also measured. Trabecular bone loss occurred in both diets (evident as early as 5-months). Cortical bone increased through month-5 and then declined. Cortical bone loss was primarily in mice on the HFWD. Inclusion of the minerals in the diet reduced bone mineral loss in both diets and improved bone strength. Bone mineral density (BMD) was also enhanced by these minerals. Of several cationic minerals known to be important to bone health, only strontium was significantly increased in bone tissue from animals fed the mineral diets, but the increase was large (5–10 fold). Serum levels of TRAP were consistently higher in mice receiving the minerals but levels of P1NP were not. These data suggest that trace minerals derived from marine red algae may be used to prevent progressive bone mineral loss in conjunction with calcium. Mineral supplementation could find use as part of an osteoporosis - prevention strategy. PMID:24096551

Preservation of bone structure and function by Lithothamnion sp. derived minerals.

PubMed

Aslam, Muhammad Nadeem; Bergin, Ingrid; Jepsen, Karl; Kreider, Jaclynn M; Graf, Kristin H; Naik, Madhav; Goldstein, Steven A; Varani, James

2013-12-01

Progressive bone mineral loss and increasing bone fragility are hallmarks of osteoporosis. A combination of minerals isolated from the red marine algae, Lithothamnion sp. was examined for ability to inhibit bone mineral loss in female mice maintained on either a standard rodent chow (control) diet or a high-fat western diet (HFWD) for 5, 12, and 18 months. At each time point, femora were subjected to μ-CT analysis and biomechanical testing. A subset of caudal vertebrae was also analyzed. Following this, individual elements were assessed in bones. Serum levels of the 5b isoform of tartrate-resistant acid phosphatase (TRAP) and procollagen type I propeptide (P1NP) were also measured. Trabecular bone loss occurred in both diets (evident as early as 5 months). Cortical bone increased through month 5 and then declined. Cortical bone loss was primarily in mice on the HFWD. Inclusion of the minerals in the diet reduced bone mineral loss in both diets and improved bone strength. Bone mineral density was also enhanced by these minerals. Of several cationic minerals known to be important to bone health, only strontium was significantly increased in bone tissue from animals fed the mineral diets, but the increase was large (5-10 fold). Serum levels of TRAP were consistently higher in mice receiving the minerals, but levels of P1NP were not. These data suggest that trace minerals derived from marine red algae may be used to prevent progressive bone mineral loss in conjunction with calcium. Mineral supplementation could find use as part of an osteoporosis-prevention strategy.

The usefulness of densitometry in predicting the composition and fragility of urolithiasis.

PubMed

Argüelles-Salido, Enrique; Lozano-Blasco, Jose Maria; Subira-Rios, Jorge; Bernardo-Villar, Pastora; Podio-Lora, Virtudes; Campoy-Martínez, Pedro; Vazquez-Albertino, Ricardo; Medina-Lopez, Rafael

2014-04-01

The choice of ideal treatment for a given lithiasis is a crucial factor for its success, minimizing the number of interventions and complications. Previous determination of stone composition and its fragility is desirable, to predict its behavior during extracorporeal shock wave lithotripsy and for evaluation of its appropriateness, or to set the indication for other techniques. To determine the role of densitometry in the prediction of composition and fragility of urinary lithiasis undergoing SWL. Experimental prospective, blinded, in vitro study using 193 urinary calculi of known composition : monohydrated calcium oxalate, mixed calcium oxalate, uric acid, and calcium carbonate, obtained from spontaneous passage or surgery. Densitometry and SWL were performed on them. We compare the mineral composition of the stone and mineral density of each composition group to check if they are characteristic of each type and correlate these parameters with the energy dose required to fragment them down to a given fragment size. Only 53 out of 193 stones showed valuable data. Calcium carbonate was the composition showing grater mineral content and density (1,24 gr and 0,47 gr/cm2), followed by mixed oxalate (0,51/0,26) and uric acid (0,52/ 0,15), finishing with the monohydrate calcium oxalate group (0,32/0,05).Only the comparison between calcium carbonate and monohydrated calcium oxalate showed statistically significant results (p<0,05). Correlation coefficients between mineral content (0,347) and density (0,424) and the energy used for stone fragmentation to a given fragment size were statistically significant (p<0,05) CONCLUSIONS: In our study, the use of densitometry to determine stone composition and lithiasic fragility did not show conclusive results due to the limited number of calculi tested. Nevertheless, there are signs that, with a different study design , more practically useful results could be achieved.

Bivariate genome-wide association meta-analysis of pediatric musculoskeletal traits reveals pleiotropic effects at the SREBF1/TOM1L2 locus.

PubMed

Medina-Gomez, Carolina; Kemp, John P; Dimou, Niki L; Kreiner, Eskil; Chesi, Alessandra; Zemel, Babette S; Bønnelykke, Klaus; Boer, Cindy G; Ahluwalia, Tarunveer S; Bisgaard, Hans; Evangelou, Evangelos; Heppe, Denise H M; Bonewald, Lynda F; Gorski, Jeffrey P; Ghanbari, Mohsen; Demissie, Serkalem; Duque, Gustavo; Maurano, Matthew T; Kiel, Douglas P; Hsu, Yi-Hsiang; C J van der Eerden, Bram; Ackert-Bicknell, Cheryl; Reppe, Sjur; Gautvik, Kaare M; Raastad, Truls; Karasik, David; van de Peppel, Jeroen; Jaddoe, Vincent W V; Uitterlinden, André G; Tobias, Jonathan H; Grant, Struan F A; Bagos, Pantelis G; Evans, David M; Rivadeneira, Fernando

2017-07-25

Bone mineral density is known to be a heritable, polygenic trait whereas genetic variants contributing to lean mass variation remain largely unknown. We estimated the shared SNP heritability and performed a bivariate GWAS meta-analysis of total-body lean mass (TB-LM) and total-body less head bone mineral density (TBLH-BMD) regions in 10,414 children. The estimated SNP heritability is 43% (95% CI: 34-52%) for TBLH-BMD, and 39% (95% CI: 30-48%) for TB-LM, with a shared genetic component of 43% (95% CI: 29-56%). We identify variants with pleiotropic effects in eight loci, including seven established bone mineral density loci: WNT4, GALNT3, MEPE, CPED1/WNT16, TNFSF11, RIN3, and PPP6R3/LRP5. Variants in the TOM1L2/SREBF1 locus exert opposing effects TB-LM and TBLH-BMD, and have a stronger association with the former trait. We show that SREBF1 is expressed in murine and human osteoblasts, as well as in human muscle tissue. This is the first bivariate GWAS meta-analysis to demonstrate genetic factors with pleiotropic effects on bone mineral density and lean mass.Bone mineral density and lean skeletal mass are heritable traits. Here, Medina-Gomez and colleagues perform bivariate GWAS analyses of total body lean mass and bone mass density in children, and show genetic loci with pleiotropic effects on both traits.

Relationship of bone mineral density to progression of knee osteoarthritis

USDA-ARS?s Scientific Manuscript database

Objective. To evaluate the longitudinal relationship between bone mineral density (BMD) and BMD changes and the progression of knee osteoarthritis (OA), as measured by cartilage outcomes. Methods. We used observational cohort data from the Vitamin D for Knee Osteoarthritis trial. Bilateral femoral ...

Application of Polychromatic µCT for Mineral Density Determination

PubMed Central

Zou, W.; Hunter, N.; Swain, M.V.

2011-01-01

Accurate assessment of mineral density (MD) provides information critical to the understanding of mineralization processes of calcified tissues, including bones and teeth. High-resolution three-dimensional assessment of the MD of teeth has been demonstrated by relatively inaccessible synchrotron radiation microcomputed tomography (SRµCT). While conventional desktop µCT (CµCT) technology is widely available, polychromatic source and cone-shaped beam geometry confound MD assessment. Recently, considerable attention has been given to optimizing quantitative data from CµCT systems with polychromatic x-ray sources. In this review, we focus on the approaches that minimize inaccuracies arising from beam hardening, in particular, beam filtration during the scan, beam-hardening correction during reconstruction, and mineral density calibration. Filtration along with lowest possible source voltage results in a narrow and near-single-peak spectrum, favoring high contrast and minimal beam-hardening artifacts. More effective beam monochromatization approaches are described. We also examine the significance of beam-hardening correction in determining the accuracy of mineral density estimation. In addition, standards for the calibration of reconstructed grey-scale attenuation values against MD, including K2PHO4 liquid phantom, and polymer-hydroxyapatite (HA) and solid hydroxyapatite (HA) phantoms, are discussed. PMID:20858779

Correlation between ultrasound velocity and densitometry in fresh and demineralized cortical bone

PubMed Central

de Mesquita, Alessandro Queiroz; Barbieri, Giuliano; Barbieri, Claudio Henrique

2016-01-01

OBJECTIVE: To compare ultrasound propagation velocity with densitometry in the diaphyseal compact cortical bone of whole sheep metatarsals. METHODS: The transverse ultrasound velocity and bone mineral density of 5-cm-long diaphyseal bone segments were first measured. The bone segments were then divided into four groups of 15 segments each and demineralized in an aqueous 0.5 N hydrochloric acid solution for 6, 12, 24 or 36 hours. All measurements were repeated after demineralization for each time duration and the values measured before and after demineralization were compared. RESULTS: Ultrasound velocity and bone mineral density decreased with demineralization time, and most differences in the pre- and post-demineralization values within each group and between groups were significant: A moderate correlation coefficient (r=0.75956) together with a moderate agreement was determined between both post-demineralization parameters, detected by the Bland-Altman method. CONCLUSION: We conclude that both ultrasound velocity and bone mineral density decrease as a result of demineralization, thus indicating that bone mineral content is of great importance for maintaining the acoustic parameters of cortical bone, as observed for cancellous bone. Ultrasound velocity can be used to evaluate both compact cortical bone quality and bone mineral density. PMID:27982167

Correlation between ultrasound velocity and densitometry in fresh and demineralized cortical bone.

PubMed

Mesquita, Alessandro Queiroz de; Barbieri, Giuliano; Barbieri, Claudio Henrique

2016-11-01

To compare ultrasound propagation velocity with densitometry in the diaphyseal compact cortical bone of whole sheep metatarsals. The transverse ultrasound velocity and bone mineral density of 5-cm-long diaphyseal bone segments were first measured. The bone segments were then divided into four groups of 15 segments each and demineralized in an aqueous 0.5 N hydrochloric acid solution for 6, 12, 24 or 36 hours. All measurements were repeated after demineralization for each time duration and the values measured before and after demineralization were compared. Ultrasound velocity and bone mineral density decreased with demineralization time, and most differences in the pre- and post-demineralization values within each group and between groups were significant: A moderate correlation coefficient (r=0.75956) together with a moderate agreement was determined between both post-demineralization parameters, detected by the Bland-Altman method. We conclude that both ultrasound velocity and bone mineral density decrease as a result of demineralization, thus indicating that bone mineral content is of great importance for maintaining the acoustic parameters of cortical bone, as observed for cancellous bone. Ultrasound velocity can be used to evaluate both compact cortical bone quality and bone mineral density.

[Physico-chemical characteristics of ambient particles settling upon leaf surface of six conifers in Beijing].

PubMed

Wang, Lei; Hasi, Eerdun; Liu, Lian-You; Gao, Shang-Yu

2007-03-01

The study on the density of ambient particles settling upon the leaf surface of six conifers in Beijing, the micro-configurations of the leaf surface, and the mineral and element compositions of the particles showed that at the same sites and for the same tree species, the density of the particles settling upon leaf surface increased with increasing ambient pollution, but for various tree species, it differed significantly, with the sequence of Sabina chinensis and Platycladus orientalis > Cedrus deodara and Pinus bungeana > P. tabulaeformis and Picea koraiensis. Due to the effects of road dust, low height leaf had a larger density of particles. The density of the particles was smaller in summer than in winter because of the rainfall and new leaf growth. The larger the roughness of leaf surface, the larger density of the particles was. In the particles, the overall content of SiO2, CaCO3, CaMg(CO3,), NaCl, 2CaSO4 . H2O, CaSO4 . 2H2O and Fe2O3 was about 10%-30%, and the main minerals were montmorillonite, illite, kaolinite and feldspar. The total content of 21 test elements in the particles reached 16%-37%, among which, Ca, Al, Fe, Mg, K, Na and S occupied 97% or more, while the others were very few and less affected by sampling sites and tree species.

Associations between the 2007 Medicare reimbursement reduction for bone mineral density testing and osteoporosis drug therapy patterns of female Medicare beneficiaries.

PubMed

Kim, Sun Jung; Lee, Joo Hun; Kim, Sulgi; Nakagawa, Shunichi; Bertelson, Heather; Lam, Julia; Yoo, Ji Won

2014-01-01

To examine how drug therapy patterns for osteoporosis have changed after the Medicare Physician Fee Schedule (MPFS) reimbursement reduction in 2007, in relation to follow-up bone mineral density (BMD) testing status. We used a retrospective temporal shift design to examine changes in drug therapy patterns before (Phase 1: January 1, 2005-December 31, 2006) and after (Phase 2: July 1, 2007-June 30, 2009) the MPFS reimbursement reduction in 2007, Cleveland, OH, USA. Participants were osteoporotic older women in Phase 1 (n=1,340) and Phase 2 (n=1,437). The main outcomes were a) adherence, b) adjustment, c) occurrence of an extended gap, and d) restarting drug therapy after an extended gap. Follow-up BMD testing status by study phase and location were also analyzed. BMD testing rates at physicians' offices decreased from 64.5% in Phase 1 to 58.4% in Phase 2 (P=0.02); however, testing rates in hospital outpatient settings increased (from 20.8% to 24.5%). There were also decreases in drug therapy adjustment from 15.9% in Phase 1 to 11.6% in Phase 2 (odds ratio [OR]: 0.73; P<0.01) and in restarting drug therapy after an extended gap (55.4% in Phase 1 and 43.6% in Phase 2; OR: 0.76; P<0.01). There were no changes in the overall rate of follow-up BMD testing. The rates of drug adjustments and restarting drug therapy after an extended gap did decrease. These decreases were more evident when follow-up BMD testing was not performed.

Bone mineral density and inflammatory and bone biomarkers after darunavir-ritonavir combined with either raltegravir or tenofovir-emtricitabine in antiretroviral-naive adults with HIV-1: a substudy of the NEAT001/ANRS143 randomised trial.

PubMed

Bernardino, Jose I; Mocroft, Amanda; Mallon, Patrick W; Wallet, Cedrick; Gerstoft, Jan; Russell, Charlotte; Reiss, Peter; Katlama, Christine; De Wit, Stephane; Richert, Laura; Babiker, Abdel; Buño, Antonio; Castagna, Antonella; Girard, Pierre-Marie; Chene, Genevieve; Raffi, Francois; Arribas, Jose R

2015-11-01

Osteopenia, osteoporosis, and low bone mineral density are frequent in patients with HIV. We assessed the 96 week loss of bone mineral density associated with a nucleoside or nucleotide reverse transcriptase inhibitor (NtRTI)-sparing regimen. Antiretroviral-naive adults with HIV were enrolled in 78 clinical sites in 15 European countries into a randomised (1:1), open-label, non-inferiority trial (NEAT001/ANRS143) assessing the efficacy and safety of darunavir (800 mg once per day) and ritonavir (100 mg once per day) plus either raltegravir (400 mg twice per day; NtRTI-sparing regimen) or tenofovir (245 mg once per day) and emtricitabine (200 mg once per day; standard regimen). For this bone-health substudy, 20 of the original sites in six countries participated, and any patient enrolled at one of these sites who met the following criteria was eligible: plasma viral loads greater than 1000 HIV RNA copies per mL and CD4 cell counts of fewer than 500 cells per μL, except in those with symptomatic HIV infection. Exclusion criteria included treatment for malignant disease, testing positive for hepatitis B virus surface antigen, pregnancy, creatinine clearance less than 60 mL per min, treatment for osteoporosis, systemic steroids, or oestrogen-replacement therapy. The two primary endpoints were the mean percentage changes in lumbar spine and total hip bone mineral density at week 48, assessed by dual energy x-ray absorptiometry (DXA) scans. We did the analysis with an intention-to-treat-exposed approach with antiretroviral modifications ignored. The parent trial is registered with ClinicalTrials.gov, number NCT01066962, and is closed to new participants. Between Aug 2, 2010, and April 18, 2011, we recruited 146 patients to the substudy, 70 assigned to the NtRTI-sparing regimen and 76 to the standard regimen. DXA data were available for 129, 121 and 107 patients at baseline, 48 and 96 weeks respectively. At week 48, the mean percentage loss in bone mineral density in the lumbar spine was greater in the standard group than in the NtRTI-sparing group (mean percentage change -2.49% vs -1.00%, mean percentage difference -1.49, 95% CI -2.94 to -0.04; p=0.046). Total hip bone mineral density loss was similarly greater at week 48 in the standard group than in the NtRTI-sparing group (mean percentage change -3.30% vs -0.73%; mean percentage difference -2.57, 95% CI -3.75 to -1.35; p<0.0001). Seven new fractures occurred during the trial (two in the NtRTI-sparing group and five in the standard group). A raltegravir-based regimen was associated with significantly less loss of bone mineral density than a standard regimen containing tenofovir disoproxil fumarate, and might be a treatment option for patients at high risk of osteopenia or osteoporosis who are not suitable for NtRTIs such as abacavir or tenofovir alafenamide. The European Union Sixth Framework Programme, Inserm-ANRS, Ministerio de Sanidad y Asuntos Sociales de España, Gilead Sciences, Janssen Pharmaceuticals, and Merck Laboratories. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effect of whole body vibration training on quadriceps strength, bone mineral density, and functional capacity in children with hemophilia: a randomized clinical trial.

PubMed

El-Shamy, S

2017-06-01

The objective was to evaluate the effects of whole body vibration training on quadriceps strength, bone mineral density, and functional capacity in children with hemophilia. Thirty children with hemophilia with age ranging from 9 to 13 years were selected and randomly assigned to either the study group that received whole body vibration training (30-40 Hz, 2-4 mm of peak-to-peak vertical plate displacement for 15 minutes/day, 3 days/week/ 12 weeks) plus the conventional physical therapy program or the control group that performed a conventional physical therapy program only. Outcomes included quadriceps strength, bone mineral density, and the functional capacity. Children in the study group showed a significant improvement in all outcomes compared with the control group. The quadriceps peak torque after treatment was 70.26 and 56.46 Nm for the study and control group, respectively (p⟨0.001). The lumbar spine bone mineral density after treatment was 0.85 and 0.72 g/cm 2 for the study and control group, respectively (p⟨0.001). The functional capacity after treatment was 325 and 290 m for the study and control group, respectively (p=0.006). Whole body vibration training is an effective modality in increasing quadriceps strength, bone mineral density, and functional capacity in children with hemophilia.

Silicosis decreases bone mineral density in rats.

PubMed

Hui, Zhang; Dingjie, Xu; Yuan, Yuan; Zhongqiu, Wei; Na, Mao; Mingjian, Bei; Yu, Gou; Guangyuan, Liu; Xuemin, Gao; Shifeng, Li; Yucong, Geng; Fang, Yang; Summer, Ross; Hong, Xu

2018-06-01

Silicosis is the most common occupational lung disease in China, and is associated with a variety of complications, many of which are poorly understood. For example, recent data indicate that silicosis associates with the development of osteopenia, and in some cases this bone loss is severe, meeting criteria for osteoporosis. Although many factors are likely to contribute to this relationship, including a sedentary lifestyle in patients with advanced silicotic lung disease, we hypothesized that silica might directly reduce bone mineral density. In the present study, six Wistar rats were exposed to silica for 24 weeks in order to induce pulmonary silicosis and examine the relationship to bone mineral density. As expected, all rats exposed to silica developed severe pulmonary fibrosis, as manifested by the formation of innumerable silicotic nodules and the deposition of large amounts of interstitial collagen. Moreover, micro-CT results showed that bone mineral density (BMD) was also significantly reduced in rats exposed to silica when compared control animals and this associated with a modest reduction in serum calcium and 25-hydroxyvitamin D levels. In addition, we found that decreased BMD was also linked to increased osteoclast activity as well as fibrosis-like changes, and to the deposition of silica within bone marrow. In summary, our findings support the hypothesis that silicosis reduces bone mineral density and provide support for ongoing investigations into the mechanisms causing osteopenia in silicosis patients. Copyright © 2018. Published by Elsevier Inc.

Effect of whole body vibration training on quadriceps strength, bone mineral density, and functional capacity in children with hemophilia: a randomized clinical trial

PubMed Central

El-Shamy, S.

2017-01-01

Objectives: The objective was to evaluate the effects of whole body vibration training on quadriceps strength, bone mineral density, and functional capacity in children with hemophilia. Methods: Thirty children with hemophilia with age ranging from 9 to 13 years were selected and randomly assigned to either the study group that received whole body vibration training (30-40 Hz, 2-4 mm of peak-to-peak vertical plate displacement for 15 minutes/day, 3 days/week/ 12 weeks) plus the conventional physical therapy program or the control group that performed a conventional physical therapy program only. Outcomes included quadriceps strength, bone mineral density, and the functional capacity. Results: Children in the study group showed a significant improvement in all outcomes compared with the control group. The quadriceps peak torque after treatment was 70.26 and 56.46 Nm for the study and control group, respectively (p<0.001). The lumbar spine bone mineral density after treatment was 0.85 and 0.72 g/cm2 for the study and control group, respectively (p<0.001). The functional capacity after treatment was 325 and 290 m for the study and control group, respectively (p=0.006). Conclusions: Whole body vibration training is an effective modality in increasing quadriceps strength, bone mineral density, and functional capacity in children with hemophilia. PMID:28574408

Hypercholesterolemia Promotes an Osteoporotic Phenotype

PubMed Central

Pelton, Kristine; Krieder, Jaclynn; Joiner, Danese; Freeman, Michael R.; Goldstein, Steven A.; Solomon, Keith R.

2013-01-01

A role for hypercholesterolemia in the development of osteoporosis has been suggested in published reports. However, few studies contain direct evidence of a role for maintenance of cholesterol homeostasis in bone health. Using isocaloric high-fat/high-cholesterol and low-fat/no-cholesterol diets in a 4-month feeding study combined with micro computed tomography analysis, we demonstrated in two different mouse strains that mice with hypercholesterolemia lose cortical and trabecular bone in the femurs and vertebrae (bone mineral density was decreased on average by ≈90 mg/mL in the cortical vertebrae in one strain) and cortical bone in the calvariae (bone mineral density was decreased on average by ≈60 mg/mL in one strain). Mechanical testing of the femurs demonstrated that loss of bone in the mice with hypercholesterolemia caused changes in the mechanical properties of the bone including loss of failure load (failure load was decreased by ≈10 N in one strain) and energy to failure. Serologic and histomorphologic analyses suggested that hypercholesterolemia promotes osteoclastogenesis. These studies support a role for hypercholesterolemia in the development of osteoporosis and provide a model with which to test intervention strategies to reduce the effects of hypercholesterolemia on bone health. PMID:22770664

Decreased Bone Mineral Density in Prader-Willi Syndrome: Comparison With Obese Subjects

PubMed Central

Butler, Merlin G.; Haber, Lawrence; Mernaugh, Ray; Carlson, Michael G.; Price, Ron; Feurer, Irene D.

2016-01-01

Bone density, anthropometric data, and markers of bone turnover were collected on 21 subjects diagnosed with Prader-Willi syndrome (PWS) and compared with 9 subjects with obesity of unknown cause. In addition, urinary N-telopeptide levels were obtained in all subjects. N-telopeptides are the peptide fragments of type I collagen, the major bone matrix material. During periods of active bone degradation or high bone turnover, high levels of N-telopeptides are excreted in the urine. However, no significant difference was detected in the urinary N-telopeptide levels when corrected for creatinine excretion (raw or transformed data) between our subjects with obesity or PWS and the observed effect size of the between-group difference was small. Although N-telopeptide levels were higher but not significantly different in the subjects with PWS compared with obese controls, the subjects with PWS had significantly decreased total bone and spine mineral density and total bone mineral content (all P < 0.001). No differences in N- telopeptide levels or bone mineral density were observed between subjects with PWS and chromosome 15q deletion or maternal disomy. Thus, decreased bone mineral density in subjects with PWS may relate to the lack of depositing bone mineral during growth when bones are becoming more dense (e.g., during adolescence), possibly because of decreased production of sex or growth hormones and/or long-standing hypotonia. It may not be caused by loss, or active degradation, of bone matrix measurable by the methods described in this study further supporting the possible need for hormone therapy during adolescence. PMID:11745993

Association of ACTN3 polymorphisms with BMD, and physical fitness of elderly women

PubMed Central

Min, Seok-Ki; Lim, Seung-Taek; Kim, Chang-Sun

2016-01-01

[Purpose] Association of ACTN3 polymorphism with bone mineral density and the physical fitness of elderly women is still unclear. Therefore, this study investigated the association between ACTN3 genotype and bone mineral density, and the physical fitness of elderly women. [Subjects and Methods] Sixty-eight elderly women (67.38 ± 3.68 years) were recruited at a Seongbuk-Gu (Seoul, Korea) Medical Service Public Health Center. Measurements of physical fitness included muscle strength, muscle endurance, flexibility, agility, balance and VO2max. Bone mineral density (BMD), upper limb muscle mass, lower limb muscle mass, percent body fat and body fat mass for the entire body were measured by dual-energy X-ray absorptiometry and an analyzer. Genotyping for the ACTN3 R577X (rs1815739) polymorphism was performed using the TaqMan approach. [Results] ACTN3 gene distribution of subjects were in the Hardy-Weinberg equilibrium (p=0.694). The relative bone mineral density trunk, pelvis and spine differed significantly among the ACTN3 genotypes. There were no significant differences among bone mineral densities of the head, arms, legs, ribs and total, but the RR genotype tended to be higher than other genotypes. Physical fitness was not significantly different among the ACTN3 genotypes. [Conclusion] These results suggest that ACTN3 gene polymorphisms could be used as one of the genetic determinants of bone mass in elderly women, and in particular, they indicate that individuals with the RR genotype have higher BMD and bone mineral composition. PMID:27821924

Exercise Training and Bone Mineral Density.

ERIC Educational Resources Information Center

Lohman, Timothy G.

1995-01-01

The effect of exercise on total and regional bone mineral density (BMD) in postmenopausal women is reviewed. Studies on non-estrogen-replete postmenopausal women show 1-2% changes in regional BMD with 1 year of weight-bearing exercises. Studies of exercise training in the estrogen-replete postmenopausal population suggest large BMD changes.…

Osteoporosis in Groups with Intellectual Disability.

ERIC Educational Resources Information Center

Center, J. R.; And Others

1994-01-01

Fifty-three adults with intellectual impairment referred to an endocrinology clinic in New South Wales (Australia) were measured for lumbar bone mineral density. Bone mineral density was significantly lower in this group than in an age and sex matched control group. Risk factors included male gender, physical inactivity, small body size,…

Correlation Between the Extent of Catalytic Activity and Charge Density of Montmorillonites

PubMed Central

Steudel, Annett; Emmerich, Katja; Lagaly, Gerhard; Schuhmann, Rainer

2010-01-01

Abstract The clay mineral montmorillonite is a member of the phyllosilicate group of minerals, which has been detected on martian soil. Montmorillonite catalyzes the condensation of activated monomers to form RNA-like oligomers. Extent of catalysis, that is, the yield of oligomers, and the length of the longest oligomer formed in these reactions widely varies with the source of montmorillonite (i.e., the locality where the mineral is mined). This study was undertaken to establish whether there exists a correlation between the extent of catalytic property and the charge density of montmorillonites. Charge density was determined by saturating the montmorillonites with alkyl ammonium cations that contained increasing lengths of alkyl chains, [CH3-(CH2)n-NH3]+, where n = 3–16 and 18, and then measuring d(001), interlayer spacing of the resulting montmorillonite-alkyl ammonium-montmorillonite complex by X-ray diffractometry (XRD). Results demonstrate that catalytic activity of montmorillonites with lower charge density is superior to that of higher charge density montmorillonite. They produce longer oligomers that contain 9 to 10 monomer units, while montmorillonite with high charge density catalyzes the formation of oligomers that contain only 4 monomer units. The charge density of montmorillonites can also be calculated from the chemical composition if elemental analysis data of the pure mineral are available. In the next mission to Mars, CheMin (Chemistry and Mineralogy), a combined X-ray diffraction/X-ray fluorescence instrument, will provide information on the mineralogical and elemental analysis of the samples. Possible significance of these results for planning the future missions to Mars for the search of organic compounds and extinct or extant life is discussed. Key Words: Mars—Origin of life—Montmorillonite—Mineral catalysis—Layer charge density—X–ray diffractometry. Astrobiology 10, 743–749. PMID:20854214

Calibration of impact ionization cosmic dust detectors: first tests to investigate how the dust density influences the signal

NASA Astrophysics Data System (ADS)

Jasmin Sterken, Veerle; Moragas-Klostermeyer, Georg; Hillier, Jon; Fielding, Lee; Lovett, Joseph; Armes, Steven; Fechler, Nina; Srama, Ralf; Bugiel, Sebastian; Hornung, Klaus

2016-10-01

Impact ionization experiments have been performed since more than 40 years for calibrating cosmic dust detectors. A linear Van de Graaff dust accelerator was used to accelerate the cosmic dust analogues of submicron to micron-size to speeds up to 80 km s^-1. Different materials have been used for calibration: iron, carbon, metal-coated minerals and most recently, minerals coated with conductive polymers. While different materials with different densities have been used for instrument calibration, a comparative analysis of dust impacts of equal material but different density is necessary: porous or aggregate-like particles are increasingly found to be present in the solar system: e.g. dust from comet 67P Churyumov-Gerasimenko [Fulle et al 2015], aggregate particles from the plumes of Enceladus [Gao et al 2016], and low-density interstellar dust [Westphal 2014 et al, Sterken et al 2015]. These recalibrations are relevant for measuring the size distributions of interplanetary and interstellar dust and thus mass budgets like the gas-to-dust mass ratio in the local interstellar cloud.We report about the calibrations that have been performed at the Heidelberg dust accelerator facility for investigating the influence of particle density on the impact ionization charge. We used the Cassini Cosmic Dust Analyzer for the target, and compared hollow versus compact silica particles in our study as a first attempt to investigate experimentally the influence of dust density on the signals obtained. Also, preliminary tests with carbon aerogel were performed, and (unsuccessful) attempts to accelerate silica aerogel. In this talk we explain the motivation of the study, the experiment set-up, the preparation of — and the materials used, the results and plans and recommendations for future tests.Fulle, M. et al 2015, The Astrophysical Journal Letters, Volume 802, Issue 1, article id. L12, 5 pp. (2015)Gao, P. et al 2016, Icarus, Volume 264, p. 227-238Westphal, A. et al 2014, Science, Volume 345, Issue 6198, pp. 786-791 (2014)Sterken, V.J. et al 2015, The Astrophysical Journal, Volume 812, Issue 2, article id. 141, 24 pp. (2015)

Spatio-temporal variation in a seed bank of a semi-arid region in northeastern Brazil

NASA Astrophysics Data System (ADS)

da Silva, Kleber A.; dos Santos, Danielle M.; dos Santos, Josiene M. F. F.; de Albuquerque, Ulysses P.; Ferraz, Elba M. N.; Araújo, Elcida de L.

2013-01-01

This study aimed to evaluate variations in the seed bank within a 3-year temporal series in order to answer the following questions: 1) Does the seed bank's species richness and seed density differ among climatic seasons and between years? 2) Are there differences in the richness and density of seed banks between the litter and mineral soil? 3) Can the seed bank's species richness and seed density be explained by characteristics such as the previous year's precipitation and soil depth (litter or mineral soil)? The samples were collected from litter and mineral soil (0-5 cm), in 210 sub-plots, during the dry and rainy seasons of each year (August 2005 through February 2008). Overall, 79 species were recorded. On average, 1 168, 304 and 302 seeds.m-2 were recorded in the seed bank during years I, II and III, respectively. This study showed that the Caatinga's seed bank is rich in herbaceous species, yet species' density and richness are low in the litter. Furthermore, about 43% of the variation in species richness and density was explained by soil depth (litter and mineral soil) and previous years' rainfall.

Nanofibers grafted on titanium alloy: the effects of fiber alignment and density on osteoblast mineralization.

PubMed

Lin, Hsin-Yi; Peng, Zhao-Xiang

2017-08-17

The surface of medical implant alloy Ti-6Al-4V was chemically modified to allow it to covalently bond with collagen/PVA nanofibers. These nanofibers were successfully attached to the Ti-6Al-4V surface in three different morphologies: randomly oriented high-density fiber, COL(H); randomly oriented low-density fiber, COL(L); and aligned high-density fiber, COL(A). The effects of the morphology of these covalently-bound collagen nanofibers on the growth and differentiation of osteoblasts were studied for 21 days. The low-density nanofibers covered approximately 80% of the Ti64 surface, while the high-density nanofibers covered nearly 100%. These covalently attached fibrous coatings remained attached to the metal surface after 3 weeks of cell culture. In the first week the aligned fibers of COL(A) allowed the osteoblasts to stretch and elongate in the direction of the fibers. This directional elongation was not seen in the cells on the randomly-oriented samples. Cells proliferated and differentiated on all three surfaces over time. By the end of the test, the amount of type I collagen secreted by the cells on COL(H) was the highest, while the degree of mineralization was highest on COL(A) among the three samples (p < 0.05). Different nanofiber morphologies changed the cell morphology and the secretion of cellular products. The mechanisms remained to be investigated. The surface of medical implant alloy Ti-6Al-4V was chemically modified to allow it to covalently bond with collagen/PVA nanofibers. The SEM micrographs in the top row show the random and aligned morphology of the collagen-PVA nanofibers. The nanofibers on COL(A) were aligned in the general direction indicated by the arrow. The second row are images from EDX titanium element mapping. The location of the titanium elements are shown as bright dots. The low-density nanofibers, COL(L), covered approximately 80% of the Ti64 surface, while the high-density nanofibers, COL(H) and COL(A), covered nearly 100%. All three surfaces demonstrated good biocompatibility for the cultured osteoblasts. The fiber alignment seemed to have an effect on early cellular morphology (day 7), collagen secretion and calcium deposition, while the density of the fibers seemed to have no significant effect on cell behavior. SEM micrographs of osteoblasts after 7 and 14 days of cell culture are shown in the third and fourth rows. The surface of COL(L) has more cell-free spots indicated by (*) on day 7 as other two surfaces were covered by cells. The nanofibers could no longer be observed and were covered with mineralized granules (circles) after 14 days of cell culture. The cells appear stretched out on the mineralized granules.

A randomized, double-blind, placebo-controlled clinical trial on the treatment of vitamin D insufficiency in postmenopausal women

PubMed Central

Hansen, Karen E.; Johnson, R. Erin; Chambers, Kaitlin R.; Johnson, Michael G.; Lemon, Christina C.; Thuy Vo, Tien Nguyen; Marvdashti, Sheeva

2015-01-01

Importance Experts debate optimal 25(OH)D levels for musculoskeletal health. Objective To compare effects of placebo, low-dose and high-dose vitamin D on one-year changes in total fractional calcium absorption, bone mineral density, Timed-Up-and-Go and 5-sit-to-stand tests and muscle mass in postmenopausal women with vitamin D insufficiency. Design Randomized, double-blind, placebo-controlled, clinical trial conducted from May 2010 to August 2014. Setting Single-center trial conducted in Madison, Wisconsin. Participants 230 postmenopausal women ≤75 years old with baseline 25(OH)D levels 14-27 ng/mL and no osteoporosis. Intervention Three arms included daily white and twice monthly yellow placebo (n=76), daily 800 IU vitamin D3 and twice monthly yellow placebo (n=76), and daily white placebo and twice monthly 50,000 IU vitamin D3 (n=79). The high-dose vitamin D regimen achieved and maintained 25(OH)D levels ≥30 ng/mL. Main Outcome Measures One year change in total fractional calcium absorption using two stable isotopes, bone mineral density and muscle mass using dual energy x-ray absorptiometry, Timed-Up-and-Go and 5-Sit-to-Stand tests, functional status (Health Assessment Questionnaire) and physical activity (Physical Activity Scale for the Elderly), with Benjamini-Hochberg correction of p-values to control the false discovery rate. Results After controlling for baseline absorption, calcium absorption increased 1% (10 mg/day) in the high-dose arm, but decreased by 2% in low-dose (p=0.005 vs. high-dose) and by 1.3% placebo (p=0.03 vs. high-dose) arms. We found no between-arm changes in spine, mean total hip, mean femoral neck or total body bone mineral density, trabecular bone score, muscle mass, 5-sit-to-stand or Timed-Up-and-Go test scores. Likewise, we found no between-arm differences for numbers of falls, number of fallers, physical activity or functional status. Conclusion and Relevance High-dose vitamin D therapy increased calcium absorption, but the effect was small and did not translate into beneficial effects on bone mineral density, muscle function, muscle mass or falls. We found no data to support experts’ recommendations to maintain serum 25(OH)D levels ≥30 ng/mL in postmenopausal women. Instead, we found that low and high-dose vitamin D were equivalent to placebo, in their effects on bone and muscle outcomes in this cohort of postmenopausal women with 25(OH)D levels <30 ng/mL. ClinicalTrials.gov.Identifier:NCT00933244 PMID:26237520

Tomographic imaging of bone composition using coherently scattered x rays

NASA Astrophysics Data System (ADS)

Batchelar, Deidre L.; Dabrowski, W.; Cunningham, Ian A.

2000-04-01

Bone tissue consists primarily of calcium hydroxyapatite crystals (bone mineral) and collagen fibrils. Bone mineral density (BMD) is commonly used as an indicator of bone health. Techniques available at present for assessing bone health provide a measure of BMD, but do not provide information about the degree of mineralization of the bone tissue. This may be adequate for assessing diseases in which the collagen-mineral ratio remains constant, as assumed in osteoporosis, but is insufficient when the mineralization state is known to change, as in osteomalacia. No tool exists for the in situ examination of collagen and hydroxyapatite density distributions independently. Coherent-scatter computed tomography (CSCT) is a technique we are developing that produces images of the low- angle scatter properties of tissue. These depend on the molecular structure of the scatterer making it possible to produce material-specific maps of each component in a conglomerate. After corrections to compensate for exposure fluctuations, self-attenuation of scatter and the temporal response of the image intensifier, material-specific images of mineral, collagen, fat and water distributions are obtained. The gray-level in these images provides the volumetric density of each component independently.

Optical changes of dentin in the near-IR as a function of mineral content

NASA Astrophysics Data System (ADS)

Berg, Rhett A.; Simon, Jacob C.; Fried, Daniel; Darling, Cynthia L.

2017-02-01

The optical properties of human dentin can change markedly due to aging, friction from opposing teeth, and acute trauma, resulting in the formation of transparent or sclerotic dentin with increased mineral density. The objective of this study was to determine the optical attenuation coefficient of human dentin tissues with different mineral densities in the near-infrared (NIR) spectral regions from 1300-2200 nm using NIR transillumination and optical coherence tomography (OCT). N=50 dentin samples of varying opacities were obtained by sectioning whole extracted teeth into 150 μm transverse sections at the cemento-enamel junction or the apical root. Transillumination images were acquired with a NIR camera and attenuation measurements were acquired at various NIR wavelengths using a NIR sensitive photodiode. Samples were imaged with transverse microradiography (gold standard) in order to determine the mineral density of each sample.

A Factorial Design Approach to Analyse the Effect of Coarse Recycled Concrete Aggregates on the Properties of Hot Mix Asphalt

NASA Astrophysics Data System (ADS)

Tanty, Kiranbala; Mukharjee, Bibhuti Bhusan; Das, Sudhanshu Shekhar

2018-06-01

The present study investigates the effect of replacement of coarse fraction of natural aggregates by recycled concrete aggregates on the properties of hot mix asphalt (HMA) using general factorial design approach. For this two factors i.e. recycled coarse aggregates percentage [RCA (%)] and bitumen content percentage [BC (%)] are considered. Tests have been carried out on the HMA type bituminous concrete, prepared with varying RCA (%) and BC (%). Analysis of variance has been performed on the experimental data to determine the effect of the chosen factors on various parameters such as stability, flow, air void, void mineral aggregate, void filled with bitumen and bulk density. The study depicts that RCA (%) and BC (%) have significant effect on the selected responses as p value is less than the chosen significance level. In addition to above, the outcomes of the statistical analysis indicate that interaction between factors have significant effects on void mineral aggregate and bulk density of bituminous concrete.

A Factorial Design Approach to Analyse the Effect of Coarse Recycled Concrete Aggregates on the Properties of Hot Mix Asphalt

NASA Astrophysics Data System (ADS)

Tanty, Kiranbala; Mukharjee, Bibhuti Bhusan; Das, Sudhanshu Shekhar

2018-02-01

The present study investigates the effect of replacement of coarse fraction of natural aggregates by recycled concrete aggregates on the properties of hot mix asphalt (HMA) using general factorial design approach. For this two factors i.e. recycled coarse aggregates percentage [RCA (%)] and bitumen content percentage [BC (%)] are considered. Tests have been carried out on the HMA type bituminous concrete, prepared with varying RCA (%) and BC (%). Analysis of variance has been performed on the experimental data to determine the effect of the chosen factors on various parameters such as stability, flow, air void, void mineral aggregate, void filled with bitumen and bulk density. The study depicts that RCA (%) and BC (%) have significant effect on the selected responses as p value is less than the chosen significance level. In addition to above, the outcomes of the statistical analysis indicate that interaction between factors have significant effects on void mineral aggregate and bulk density of bituminous concrete.

Automated segmentation of knee and ankle regions of rats from CT images to quantify bone mineral density for monitoring treatments of rheumatoid arthritis

NASA Astrophysics Data System (ADS)

Cruz, Francisco; Sevilla, Raquel; Zhu, Joe; Vanko, Amy; Lee, Jung Hoon; Dogdas, Belma; Zhang, Weisheng

2014-03-01

Bone mineral density (BMD) obtained from a CT image is an imaging biomarker used pre-clinically for characterizing the Rheumatoid arthritis (RA) phenotype. We use this biomarker in animal studies for evaluating disease progression and for testing various compounds. In the current setting, BMD measurements are obtained manually by selecting the regions of interest from three-dimensional (3-D) CT images of rat legs, which results in a laborious and low-throughput process. Combining image processing techniques, such as intensity thresholding and skeletonization, with mathematical techniques in curve fitting and curvature calculations, we developed an algorithm for quick, consistent, and automatic detection of joints in large CT data sets. The implemented algorithm has reduced analysis time for a study with 200 CT images from 10 days to 3 days and has improved the robust detection of the obtained regions of interest compared with manual segmentation. This algorithm has been used successfully in over 40 studies.

Associations of low vitamin D and elevated parathyroid hormone concentrations with bone mineral density in perinatally HIV-infected children

USDA-ARS?s Scientific Manuscript database

Background: Perinatally HIV-infected (PHIV) children have, on average, lower bone mineral density (BMD) than perinatally HIV-exposed uninfected (PHEU) and healthy children. Low 25-hydroxy vitamin D [25(OH)D] and elevated parathyroid hormone (PTH) concentrations may lead to suboptimal bone accrual. ...

Association between sleep duration, insomnia symptoms and bone mineral density in older Puerto Rican adults

USDA-ARS?s Scientific Manuscript database

Objective: To examine the association between sleep patterns (sleep duration and insomnia symptoms) and total and regional bone mineral density (BMD) among older Boston Puerto Rican adults. Materials/Methods: We conducted a cross-sectional study including 750 Puerto Rican adults, aged 47–79 y livi...

Longitudinal study of bone loss in chronic spinal cord injury patients

PubMed Central

Karapolat, Inanc; Karapolat, Hale Uzumcugil; Kirazli, Yesim; Capaci, Kazim; Akkoc, Yesim; Kumanlioglu, Kamil

2015-01-01

[Purpose] This prospective longitudinal study evaluated the changes in bone metabolism markers and bone mineral density of spinal cord injury patients over 3 years. We also assessed the relationships among the bone mineral density, bone metabolism, and clinical data of spinal cord injury patients. [Subjects and Methods] We assessed the clinical data (i.e., immobilization due to surgery, neurological status, neurological level, and extent of lesion) in 20 spinal cord injury patients. Bone mineral density, and hormonal and biochemical markers of the patients were measured at 0, 6, 12, and 36 months. [Results] Femoral neck T score decreased significantly at 36 months (p < 0.05). Among the hormonal markers, parathyroid hormone and vitamin D were significantly elevated, while bone turnover markers (i.e., deoxypyridinoline and osteocalcin) were significantly decreased at 12 and 36 months (p < 0.05). [Conclusion] Bone mineral density of the femoral neck decreases significantly during the long-term follow-up of patients with spinal cord injury due to osteoporosis. This could be due to changes in hormonal and bone turnover markers. PMID:26157234

Mineral density volume gradients in normal and diseased human tissues

DOE PAGES

Djomehri, Sabra I.; Candell, Susan; Case, Thomas; ...

2015-04-09

Clinical computed tomography provides a single mineral density (MD) value for heterogeneous calcified tissues containing early and late stage pathologic formations. The novel aspect of this study is that, it extends current quantitative methods of mapping mineral density gradients to three dimensions, discretizes early and late mineralized stages, identifies elemental distribution in discretized volumes, and correlates measured MD with respective calcium (Ca) to phosphorus (P) and Ca to zinc (Zn) elemental ratios. To accomplish this, MD variations identified using polychromatic radiation from a high resolution micro-computed tomography (micro-CT) benchtop unit were correlated with elemental mapping obtained from a microprobe X-raymore » fluorescence (XRF) using synchrotron monochromatic radiation. Digital segmentation of tomograms from normal and diseased tissues (N=5 per group; 40-60 year old males) contained significant mineral density variations (enamel: 2820-3095mg/cc, bone: 570-1415mg/cc, cementum: 1240-1340mg/cc, dentin: 1480-1590mg/cc, cementum affected by periodontitis: 1100-1220mg/cc, hypomineralized carious dentin: 345-1450mg/cc, hypermineralized carious dentin: 1815-2740mg/cc, and dental calculus: 1290-1770mg/cc). A plausible linear correlation between segmented MD volumes and elemental ratios within these volumes was established, and Ca/P ratios for dentin (1.49), hypomineralized dentin (0.32-0.46), cementum (1.51), and bone (1.68) were observed. Furthermore, varying Ca/Zn ratios were distinguished in adapted compared to normal tissues, such as in bone (855-2765) and in cementum (595-990), highlighting Zn as an influential element in prompting observed adaptive properties. Hence, results provide insights on mineral density gradients with elemental concentrations and elemental footprints that in turn could aid in elucidating mechanistic processes for pathologic formations.« less

Mineral density volume gradients in normal and diseased human tissues

DOE Office of Scientific and Technical Information (OSTI.GOV)

Djomehri, Sabra I.; Candell, Susan; Case, Thomas

Clinical computed tomography provides a single mineral density (MD) value for heterogeneous calcified tissues containing early and late stage pathologic formations. The novel aspect of this study is that, it extends current quantitative methods of mapping mineral density gradients to three dimensions, discretizes early and late mineralized stages, identifies elemental distribution in discretized volumes, and correlates measured MD with respective calcium (Ca) to phosphorus (P) and Ca to zinc (Zn) elemental ratios. To accomplish this, MD variations identified using polychromatic radiation from a high resolution micro-computed tomography (micro-CT) benchtop unit were correlated with elemental mapping obtained from a microprobe X-raymore » fluorescence (XRF) using synchrotron monochromatic radiation. Digital segmentation of tomograms from normal and diseased tissues (N=5 per group; 40-60 year old males) contained significant mineral density variations (enamel: 2820-3095mg/cc, bone: 570-1415mg/cc, cementum: 1240-1340mg/cc, dentin: 1480-1590mg/cc, cementum affected by periodontitis: 1100-1220mg/cc, hypomineralized carious dentin: 345-1450mg/cc, hypermineralized carious dentin: 1815-2740mg/cc, and dental calculus: 1290-1770mg/cc). A plausible linear correlation between segmented MD volumes and elemental ratios within these volumes was established, and Ca/P ratios for dentin (1.49), hypomineralized dentin (0.32-0.46), cementum (1.51), and bone (1.68) were observed. Furthermore, varying Ca/Zn ratios were distinguished in adapted compared to normal tissues, such as in bone (855-2765) and in cementum (595-990), highlighting Zn as an influential element in prompting observed adaptive properties. Hence, results provide insights on mineral density gradients with elemental concentrations and elemental footprints that in turn could aid in elucidating mechanistic processes for pathologic formations.« less

Mineral density volume gradients in normal and diseased human tissues.

PubMed

Djomehri, Sabra I; Candell, Susan; Case, Thomas; Browning, Alyssa; Marshall, Grayson W; Yun, Wenbing; Lau, S H; Webb, Samuel; Ho, Sunita P

2015-01-01

Clinical computed tomography provides a single mineral density (MD) value for heterogeneous calcified tissues containing early and late stage pathologic formations. The novel aspect of this study is that, it extends current quantitative methods of mapping mineral density gradients to three dimensions, discretizes early and late mineralized stages, identifies elemental distribution in discretized volumes, and correlates measured MD with respective calcium (Ca) to phosphorus (P) and Ca to zinc (Zn) elemental ratios. To accomplish this, MD variations identified using polychromatic radiation from a high resolution micro-computed tomography (micro-CT) benchtop unit were correlated with elemental mapping obtained from a microprobe X-ray fluorescence (XRF) using synchrotron monochromatic radiation. Digital segmentation of tomograms from normal and diseased tissues (N=5 per group; 40-60 year old males) contained significant mineral density variations (enamel: 2820-3095 mg/cc, bone: 570-1415 mg/cc, cementum: 1240-1340 mg/cc, dentin: 1480-1590 mg/cc, cementum affected by periodontitis: 1100-1220 mg/cc, hypomineralized carious dentin: 345-1450 mg/cc, hypermineralized carious dentin: 1815-2740 mg/cc, and dental calculus: 1290-1770 mg/cc). A plausible linear correlation between segmented MD volumes and elemental ratios within these volumes was established, and Ca/P ratios for dentin (1.49), hypomineralized dentin (0.32-0.46), cementum (1.51), and bone (1.68) were observed. Furthermore, varying Ca/Zn ratios were distinguished in adapted compared to normal tissues, such as in bone (855-2765) and in cementum (595-990), highlighting Zn as an influential element in prompting observed adaptive properties. Hence, results provide insights on mineral density gradients with elemental concentrations and elemental footprints that in turn could aid in elucidating mechanistic processes for pathologic formations.

Mineral Density Volume Gradients in Normal and Diseased Human Tissues

PubMed Central

Djomehri, Sabra I.; Candell, Susan; Case, Thomas; Browning, Alyssa; Marshall, Grayson W.; Yun, Wenbing; Lau, S. H.; Webb, Samuel; Ho, Sunita P.

2015-01-01

Clinical computed tomography provides a single mineral density (MD) value for heterogeneous calcified tissues containing early and late stage pathologic formations. The novel aspect of this study is that, it extends current quantitative methods of mapping mineral density gradients to three dimensions, discretizes early and late mineralized stages, identifies elemental distribution in discretized volumes, and correlates measured MD with respective calcium (Ca) to phosphorus (P) and Ca to zinc (Zn) elemental ratios. To accomplish this, MD variations identified using polychromatic radiation from a high resolution micro-computed tomography (micro-CT) benchtop unit were correlated with elemental mapping obtained from a microprobe X-ray fluorescence (XRF) using synchrotron monochromatic radiation. Digital segmentation of tomograms from normal and diseased tissues (N=5 per group; 40-60 year old males) contained significant mineral density variations (enamel: 2820-3095mg/cc, bone: 570-1415mg/cc, cementum: 1240-1340mg/cc, dentin: 1480-1590mg/cc, cementum affected by periodontitis: 1100-1220mg/cc, hypomineralized carious dentin: 345-1450mg/cc, hypermineralized carious dentin: 1815-2740mg/cc, and dental calculus: 1290-1770mg/cc). A plausible linear correlation between segmented MD volumes and elemental ratios within these volumes was established, and Ca/P ratios for dentin (1.49), hypomineralized dentin (0.32-0.46), cementum (1.51), and bone (1.68) were observed. Furthermore, varying Ca/Zn ratios were distinguished in adapted compared to normal tissues, such as in bone (855-2765) and in cementum (595-990), highlighting Zn as an influential element in prompting observed adaptive properties. Hence, results provide insights on mineral density gradients with elemental concentrations and elemental footprints that in turn could aid in elucidating mechanistic processes for pathologic formations. PMID:25856386

Cervical vertebral bone mineral density changes in adolescents during orthodontic treatment.

PubMed

Crawford, Bethany; Kim, Do-Gyoon; Moon, Eun-Sang; Johnson, Elizabeth; Fields, Henry W; Palomo, J Martin; Johnston, William M

2014-08-01

The cervical vertebral maturation (CVM) stages have been used to estimate facial growth status. In this study, we examined whether cone-beam computed tomography images can be used to detect changes of CVM-related parameters and bone mineral density distribution in adolescents during orthodontic treatment. Eighty-two cone-beam computed tomography images were obtained from 41 patients before (14.47 ± 1.42 years) and after (16.15 ± 1.38 years) orthodontic treatment. Two cervical vertebral bodies (C2 and C3) were digitally isolated from each image, and their volumes, means, and standard deviations of gray-level histograms were measured. The CVM stages and mandibular lengths were also estimated after converting the cone-beam computed tomography images. Significant changes for the examined variables were detected during the observation period (P ≤0.018) except for C3 vertebral body volume (P = 0.210). The changes of CVM stage had significant positive correlations with those of vertebral body volume (P ≤0.021). The change of the standard deviation of bone mineral density (variability) showed significant correlations with those of vertebral body volume and mandibular length for C2 (P ≤0.029). The means and variability of the gray levels account for bone mineral density and active remodeling, respectively. Our results indicate that bone mineral density distribution and the volume of the cervical vertebral body changed because of active bone remodeling during maturation. Copyright © 2014 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

Molecular mechanics of mineralized collagen fibrils in bone

PubMed Central

Nair, Arun K.; Gautieri, Alfonso; Chang, Shu-Wei; Buehler, Markus J.

2013-01-01

Bone is a natural composite of collagen protein and the mineral hydroxyapatite. The structure of bone is known to be important to its load-bearing characteristics, but relatively little is known about this structure or the mechanism that govern deformation at the molecular scale. Here we perform full-atomistic calculations of the three-dimensional molecular structure of a mineralized collagen protein matrix to try to better understand its mechanical characteristics under tensile loading at various mineral densities. We find that as the mineral density increases, the tensile modulus of the network increases monotonically and well beyond that of pure collagen fibrils. Our results suggest that the mineral crystals within this network bears up to four times the stress of the collagen fibrils, whereas the collagen is predominantly responsible for the material’s deformation response. These findings reveal the mechanism by which bone is able to achieve superior energy dissipation and fracture resistance characteristics beyond its individual constituents. PMID:23591891

Somatic maturation and the relationship between bone mineral variables and types of sports among adolescents: cross-sectional study.

PubMed

Agostinete, Ricardo Ribeiro; Ito, Igor Hideki; Kemper, Han; Pastre, Carlos Marcelo; Rodrigues-Júnior, Mário Antônio; Luiz-de-Marco, Rafael; Fernandes, Rômulo Araújo

2017-01-01

Peak height velocity (PHV) is an important maturational event during adolescence that affects skeleton size. The objective here was to compare bone variables in adolescents who practiced different types of sports, and to identify whether differences in bone variables attributed to sports practice were dependent on somatic maturation status. Cross-sectional study, São Paulo State University (UNESP). The study was composed of 93 adolescents (12 to 16.5 years old), divided into three groups: no-sport group (n = 42), soccer/basketball group (n = 26) and swimming group (n = 25). Bone mineral density and content were measured using dual-energy x-ray absorptiometry and somatic maturation was estimated through using peak height velocity. Data on training load were provided by the coaches. Adolescents whose PHV occurred at an older age presented higher bone mineral density in their upper limbs (P = 0.018). After adjustments for confounders, such as somatic maturation, the swimmers presented lower values for bone mineral density in their lower limbs, spine and whole body. Only the bone mineral density in the upper limbs was similar between the groups. There was a negative relationship between whole-body bone mineral content and the weekly training hours (β: -1563.967; 95% confidence interval, CI: -2916.484 to -211.450). The differences in bone variables attributed to sport practice occurred independently of maturation, while high training load in situations of hypogravity seemed to be related to lower bone mass in swimmers.

Rapidly assessing changes in bone mineral balance using natural stable calcium isotopes

PubMed Central

Morgan, Jennifer L. L.; Skulan, Joseph L.; Gordon, Gwyneth W.; Romaniello, Stephen J.; Smith, Scott M.; Anbar, Ariel D.

2012-01-01

The ability to rapidly detect changes in bone mineral balance (BMB) would be of great value in the early diagnosis and evaluation of therapies for metabolic bone diseases such as osteoporosis and some cancers. However, measurements of BMB are hampered by difficulties with using biochemical markers to quantify the relative rates of bone resorption and formation and the need to wait months to years for altered BMB to produce changes in bone mineral density large enough to resolve by X-ray densitometry. We show here that, in humans, the natural abundances of Ca isotopes in urine change rapidly in response to changes in BMB. In a bed rest experiment, use of high-precision isotope ratio MS allowed the onset of bone loss to be detected in Ca isotope data after about 1 wk, long before bone mineral density has changed enough to be detectable with densitometry. The physiological basis of the relationship between Ca isotopes and BMB is sufficiently understood to allow quantitative translation of changes in Ca isotope abundances to changes in bone mineral density using a simple model. The rate of change of bone mineral density inferred from Ca isotopes is consistent with the rate observed by densitometry in long-term bed rest studies. Ca isotopic analysis provides a powerful way to monitor bone loss, potentially making it possible to diagnose metabolic bone disease and track the impact of treatments more effectively than is currently possible. PMID:22652567

Treatment with eldecalcitol positively affects mineralization, microdamage, and collagen crosslinks in primate bone.

PubMed

Saito, Mitsuru; Grynpas, Marc D; Burr, David B; Allen, Matthew R; Smith, Susan Y; Doyle, Nancy; Amizuka, Norio; Hasegawa, Tomoka; Kida, Yoshikuni; Marumo, Keishi; Saito, Hitoshi

2015-04-01

Eldecalcitol (ELD), an active form of vitamin D analog approved for the treatment of osteoporosis in Japan, increases lumbar spine bone mineral density (BMD), suppresses bone turnover markers, and reduces fracture risk in patients with osteoporosis. We have previously reported that treatment with ELD for 6 months improved the mechanical properties of the lumbar spine in ovariectomized (OVX) cynomolgus monkeys. ELD treatment increased lumbar BMD, suppressed bone turnover markers, and reduced histomorphometric parameters of both bone formation and resorption in vertebral trabecular bone. In this study, we elucidated the effects of ELD on bone quality (namely, mineralization, microarchitecture, microdamage, and bone collagen crosslinks) in OVX cynomolgus monkeys in comparison with OVX-vehicle control monkeys. Density fractionation of bone powder prepared from lumbar vertebrae revealed that ELD treatment shifted the distribution profile of bone mineralization to a higher density, and backscattered electron microscopic imaging showed improved trabecular bone connectivity in the ELD-treated groups. Higher doses of ELD more significantly reduced the amount of microdamage compared to OVX-vehicle controls. The fractionated bone powder samples were divided according to their density, and analyzed for collagen crosslinks. Enzymatic crosslinks were higher in both the high-density (≥2.0 mg/mL) and low-density (<2.0 mg/mL) fractions from the ELD-treated groups than in the corresponding fractions in the OVX-vehicle control groups. On the other hand, non-enzymatic crosslinks were lower in both the high- and low-density fractions. These observations indicated that ELD treatment stimulated the enzymatic reaction of collagen crosslinks and bone mineralization, but prevented non-enzymatic reaction of collagen crosslinks and accumulation of bone microdamage. Bone anti-resorptive agents such as bisphosphonates slow down bone remodeling so that bone mineralization, bone microdamage, and non-enzymatic collagen crosslinks all increase. Bone anabolic agents such as parathyroid hormone decrease bone mineralization and bone microdamage by stimulating bone remodeling. ELD did not fit into either category. Histological analysis indicated that the ELD treatment strongly suppressed bone resorption by reducing the number of osteoclasts, while also stimulating focal bone formation without prior bone resorption (bone minimodeling). These bidirectional activities of ELD may account for its unique effects on bone quality. Copyright © 2014. Published by Elsevier Inc.

Are breast density and bone mineral density independent risk factors for breast cancer?

PubMed

Kerlikowske, Karla; Shepherd, John; Creasman, Jennifer; Tice, Jeffrey A; Ziv, Elad; Cummings, Steve R

2005-03-02

Mammographic breast density and bone mineral density (BMD) are markers of cumulative exposure to estrogen. Previous studies have suggested that women with high mammographic breast density or high BMD are at increased risk of breast cancer. We determined whether mammographic breast density and BMD of the hip and spine are correlated and independently associated with breast cancer risk. We conducted a cross-sectional study (N = 15,254) and a nested case-control study (of 208 women with breast cancer and 436 control subjects) among women aged 28 years or older who had a screening mammography examination and hip BMD measurement within 2 years. Breast density for 3105 of the women was classified using the American College of Radiology Breast Imaging Reporting and Data System (BI-RADS) categories, and percentage mammographic breast density among the case patients and control subjects was quantified with a computer-based threshold method. Spearman rank partial correlation coefficient and Pearson's correlation coefficient were used to examine correlations between BI-RADS breast density and BMD and between percentage mammographic breast density and BMD, respectively, in women without breast cancer. Logistic regression was used to examine the association of breast cancer with percentage mammographic breast density and BMD. All statistical tests were two-sided. Neither BI-RADS breast density nor percentage breast density was correlated with hip or spine BMD (correlation coefficient = -.02 and -.01 for BI-RADS, respectively, and -.06 and .01 for percentage breast density, respectively). Neither hip BMD nor spine BMD had a statistically significant relationship with breast cancer risk. Women with breast density in the highest sextile had an approximately threefold increased risk of breast cancer compared with women in the lowest sextile (odds ratio = 2.7, 95% confidence interval = 1.4 to 5.4); adjusting for hip or spine BMD did not change the association between breast density and breast cancer risk. Breast density is strongly associated with increased risk of breast cancer, even after taking into account reproductive and hormonal risk factors, whereas BMD, although a possible marker of lifetime exposure to estrogen, is not. Thus, a component of breast density that is independent of estrogen-mediated effects may contribute to breast cancer risk.

Melt segregation from partially molten source regions - The importance of melt density and source region size

NASA Technical Reports Server (NTRS)

Stolper, E.; Hager, B. H.; Walker, D.; Hays, J. F.

1981-01-01

An investigation is conducted regarding the changes expected in the density contrast between basic melts and peridotites with increasing pressure using the limited data available on the compressibilities of silicate melts and data on the densities of mantle minerals. It is concluded that since compressibilities of silicate melts are about an order of magnitude greater than those of mantle minerals, the density contrast between basic melts and mantle minerals must diminish significantly with increasing pressure. An earlier analysis regarding the migration of liquid in partially molten source regions conducted by Walker et al. (1978) is extended, giving particular attention to the influence of the diminished density contrast between melt and residual crystals with increasing source region depth and to the influence of source region size. This analysis leads to several generalizations concerning the factors influencing the depths at which magmas will segregate from their source regions and the degrees of partial melting that can be achieved in these source regions before melt segregation occurs.

Bone density changes in premature ovarian insufficiency patients who have had term pregnancies.

PubMed

Velasco, Mariana; Holloway, Debra; Rymer, Janice

2014-12-01

Premature ovarian insufficiency affects 1% of women under the age of 40 and is associated with a hypoestrogenic state, potentially leading to multiple comorbidities including reduced bone density and fertility. An unpredictable ovarian function is observed in 50% of patients with 5-10% being able to achieve a pregnancy. Longitudinal studies have shown a temporary decline in bone mineral density of up to 5% during pregnancy and lactation in healthy women, with the loss of bone density post-partum being proportional to the period of breastfeeding. Effects of pregnancy in women with premature ovarian insufficiency have not been widely documented. Nevertheless, a lower bone mineral density baseline has been observed pre-conceptually, associated with both the hypoestrogenic state of the condition and the possibility that premature ovarian insufficiency was developed prior to achieving peak bone mass. This may suggest that breastfeeding could cause further deterioration in bone mineral density that may not be easy to recover from due to the reduced baseline levels. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Relationships among diet, physical activity, and dual plane dual-energy X-ray absorptiometry bone outcomes in pre-pubertalgirls.

PubMed

Ren, Jie; Brann, Lynn S; Bruening, Kay S; Scerpella, Tamara A; Dowthwaite, Jodi N

2017-12-01

In pre-pubertal girls, nutrient intakes and non-aquatic organized activity were evaluated as factors in vertebral body bone mass, structure, and strength. Activity, vitamin B 12 , and dietary fiber predicted bone outcomes most consistently. Exercise and vitamin B 12 appear beneficial, whereas high fiber intake appears to be adverse for vertebral body development. Childhood development sets the baseline for adult fracture risk. Most studies evaluate development using postero-anterior (PA) dual-energy X-ray absorptiometry (DXA) areal bone mineral density, bone mineral content, and bone mineral apparent density. In a prior analysis, we demonstrated that PA DXA reflects posterior element properties, rather than vertebral body fracture sites, such that loading is associated with subtle differences in vertebral body geometry, not 3D density. The current analysis is restricted to pre-pubertal girls, for a focused exploration of key nutrient intakes and physical activity as factors in dual plane indices of vertebral body geometry, density, and strength. This cross-sectional analysis used paired PA and supine lateral (LAT) lumbar spine DXA scans to assess "3D" vertebral body bone mineral apparent density (PALATBMAD), "3D" index of structural strength in axial compression (PALATIBS), and fracture risk index (PALATFRI). Diet data were collected using the Youth/Adolescent Questionnaire (YAQ, 1995); organized physical activity was recorded via calendar-based form. Pearson correlations and backward stepwise multiple linear regression analyzed associations among key nutrients, physical activity, and bone outcomes. After accounting for activity and key covariates, fiber, unsupplemented vitamin B 12 , zinc, carbohydrate, vitamin C, unsupplemented magnesium, and unsupplemented calcium intake explained significant variance for one or more bone outcomes (p < 0.05). After adjustment for influential key nutrients and covariates, activity exposure was associated with postero-anterior (PA) areal bone mineral density, PA bone mineral content, PA width, lateral (LAT) BMC, "3D" bone cross-sectional area (coronal plane), "3D" PALATIBS, and PALATFRI benefits (p < 0.05). Physical activity, fiber intake, and unsupplemented B 12 intake appear to influence vertebral body bone mass, density, geometry, and strength in well-nourished pre-pubertal girls; high fiber intakes may adversely affect childhood vertebral body growth.

Estradiol-loaded PLGA nanoparticles for improving low bone mineral density of cancellous bone caused by osteoporosis: Application of enhanced charged nanoparticles with iontophoresis.

PubMed

Takeuchi, Issei; Kobayashi, Shiori; Hida, Yukari; Makino, Kimiko

2017-07-01

Postmenopausal osteoporosis among older women, which occurs by an ovarian hormone deficiency, is one of the major public health problems. 17 β-estradiol (E2) is used to prevent and treat this disease as a drug of hormone replacement therapy. In oral administration, E2 is significantly affected by first-pass hepatic metabolism, and high dose administration must be needed to obtain drug efficacy. Therefore, alternative administration route is needed, and we have focused on the transdermal drug delivery system. In this study, we have prepared E2-loaded poly(DL-lactide-co-glycolide) (PLGA) nanoparticles for osteoporosis by using a combination of an antisolvent diffusion method with preferential solvation. The average particle diameter of the nanoparticles was 110.0±41.0nm and the surface charge number density was 82 times higher than that of conventional E2-loaded PLGA nanoparticles. Therapeutic evaluation of E2-loaded PLGA nanoparticles was carried out using ovariectomized female rats. Therapeutic efficacy was evaluated to measure bone mineral density of cancellous bone using an X-ray CT system. When the E2-loaded PLGA nanoparticles were administrated once a week, bone mineral density was significantly higher than that of the non-treated group at 60days after the start of treatment. Also, in the group administered this nanoparticle twice a week, the bone mineral density increased significantly at 45days after the start of treatment. From these results, it was revealed that E2-loaded PLGA nanoparticles with iontophoresis were useful to recover bone mineral density of cancellous bone, and it was also suggested that they extend the dosing interval of E2. Copyright © 2017 Elsevier B.V. All rights reserved.

Macroscopic anisotropic bone material properties in children with severe osteogenesis imperfecta.

PubMed

Albert, Carolyne; Jameson, John; Tarima, Sergey; Smith, Peter; Harris, Gerald

2017-11-07

Children with severe osteogenesis imperfecta (OI) typically experience numerous fractures and progressive skeletal deformities over their lifetime. Recent studies proposed finite element models to assess fracture risk and guide clinicians in determining appropriate intervention in children with OI, but lack of appropriate material property inputs remains a challenge. This study aimed to characterize macroscopic anisotropic cortical bone material properties and investigate relationships with bone density measures in children with severe OI. Specimens were obtained from tibial or femoral shafts of nine children with severe OI and five controls. The specimens were cut into beams, characterized in bending, and imaged by synchrotron radiation X-ray micro-computed tomography. Longitudinal modulus of elasticity, yield strength, and bending strength were 32-65% lower in the OI group (p<0.001). Yield strain did not differ between groups (p≥0.197). In both groups, modulus and strength were lower in the transverse direction (p≤0.009), but anisotropy was less pronounced in the OI group. Intracortical vascular porosity was almost six times higher in the OI group (p<0.001), but no differences were observed in osteocyte lacunar porosity between the groups (p=0.086). Volumetric bone mineral density was lower in the OI group (p<0.001), but volumetric tissue mineral density was not (p=0.770). Longitudinal OI bone modulus and strength were correlated with volumetric bone mineral density (p≤0.024) but not volumetric tissue mineral density (p≥0.099). Results indicate that cortical bone in children with severe OI yields at the same strain as normal bone, and that their decreased bone material strength is associated with reduced volumetric bone mineral density. These results will enable the advancement of fracture risk assessment capability in children with severe OI. Copyright © 2017 Elsevier Ltd. All rights reserved.

Bone Turnover Markers and Lean Mass in Pubescent Boys: Comparison Between Elite Soccer Players and Controls.

PubMed

Nebigh, Ammar; Abed, Mohamed Elfethi; Borji, Rihab; Sahli, Sonia; Sellami, Slaheddine; Tabka, Zouhair; Rebai, Haithem

2017-11-01

The aim of this study was to examine the relationship between bone mass and bone turnover markers with lean mass (LM) in pubescent soccer players. Two groups participated in this study, which included 65 elite young soccer players who trained for 6-8 hours per week and 60 controls. Bone mineral density; bone mineral content in the whole body, lower limbs, lumbar spine, and femoral neck; biochemical markers of osteocalcin; bone-specific alkaline phosphatase; C-telopeptide type I collagen; and total LM were assessed. Young soccer players showed higher bone mineral density and bone mineral content in the whole body and weight-bearing sites (P < .001). Indeed, the total LM correlated with whole-body bone mineral density and bone mineral content (P < .001). There were significant differences within the bone formation markers and osteocalcin (formation)/C-telopeptide type I collagen (resorption) ratio between young soccer players compared with the control group, but no significant difference in C-telopeptide type I collagen was observed between the 2 groups. This study showed a significant positive correlation among bone-specific alkaline phosphatase, osteocalcin, and total LM (r = .29; r = .31; P < .05) only for the young soccer players. Findings of this study highlight the importance of soccer practice for bone mineral parameters and bone turnover markers during the puberty stage.

Changes in mineral metabolism with immobilization/space flight

NASA Technical Reports Server (NTRS)

Gallagher, J. C.

1989-01-01

Researchers are still unsure of the accuracy of previous bone density measurements of their significance following a period of weightlessness. Rapid technological advances in the measurement of bone density will enable us now to measure bone density accurately at multiple sites in the skeleton with doses of radiation less than that given by a spine x ray. It may not be possible to obtain this type of information before the next series of space flights take place, although the bed-rest model may provide supporting information. Extensive testing of bone density on every astronaut should be performed before and after the space flight. Prevention and treatment can only be undertaken after gathering sufficient baseline information. The use of exercise in preventing bone loss is still highly speculative, but represents a relatively easy approach to the problem in terms of study.

Effect of rotopositioning on the growth and maturation of mandibular bone in immobilized Rhesus monkeys

NASA Technical Reports Server (NTRS)

Simmons, D. J.; Parvin, C.; Smith, K. C.; France, P.; Kazarian, L.

1986-01-01

The rates of bone formation and mineralization in the mandibular cortex of juvenile Rhesus monkeys exposed to immobilization/rotopositioning are evaluated. The monkeys were restrained in a supine position and rotated 90 deg every 30 minutes through a full 360 deg for 14 days. The microscopic distribution of mineral densities in osteonal bone and the porosity of cortical bone are studied using microradiographs, and osteon closure rates are assessed using tetracycline labeling; normal distributions of osteons of different mineral density and cortical bone porosity values are observed. It is concluded that 14 days of immobilization/rotopositioning did not cause abnormal changes in osteon mineralization, cortical porosity, and osteon closure rates.

Difference in Bone Mineral Density between Young versus Midlife Women

ERIC Educational Resources Information Center

Sanderson, Sonya; Anderson, Pamela S.; Benton, Melissa J.

2016-01-01

Background: Older age is a risk factor for low bone mineral density (BMD). Older women have been found to have lower BMD than younger women. Recent trends for decreased calcium consumption and physical activity may place younger women at greater risk than previously anticipated. Purpose: The purpose of this study was to evaluate the effect of age…

Exercise Effects on Fitness and Bone Mineral Density in Early Postmenopausal Women: 1-Year EFOPS Results.

ERIC Educational Resources Information Center

Kemmler, Wolfgang; Engelke, Klaus; Lauber, Dirk; Weineck, Juergen; Hensen, Johannes; Kalender, Willi A.

2002-01-01

Investigated the effect of intense exercise training on physical fitness, coronary heart disease, bone mineral density (BMD), and parameters related to quality of life in early postmenopausal women with osteopenia. Data on woman in control and exercise training groups indicated that the intense exercise training program was effective in improving…

Associations of APOE gene polymorphisms with bone mineral density and fracture risk: a meta-analysis

USDA-ARS?s Scientific Manuscript database

Apolipoprotein E (APOE) has been studied for its potential role in osteoporosis risk. It is hypothesized that genetic variation at common APOE loci, known as E2, E3, and E4, may modulate bone mineral density (BMD) through its effects on lipoproteins and vitamin K transport. To determine the associa...

People with Mental Retardation Have an Increased Prevalence of Osteoporosis: A Population Study.

ERIC Educational Resources Information Center

Center, Jacqueline; Beange, Helen; McElduff, Aidan

1998-01-01

Prevalence of and risk factors for osteoporosis in 94 young adults with mental retardation was examined. Results showed they had lower bone mineral density when compared to controls. Factors associated with low bone mineral density included small body size, hypgonadism, and Down syndrome. Low vitamin D levels were common. (Author/CR)

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

PubMed

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.

Dietary long-chain inulin reduces abdominal fat but has no effect on bone density in growing female rats.

PubMed

Jamieson, Jennifer A; Ryz, Natasha R; Taylor, Carla G; Weiler, Hope A

2008-08-01

New strategies to improve Ca absorption and bone health are needed to address the current state of osteoporosis prevention and management. Inulin-type fructans have shown great promise as a dietary intervention strategy, but have not yet been tested in a young female model. Our objective was to investigate the effect of long chain (LC) inulin on bone mineralization and density in growing, female rats, as well as the quality of growth. Weanling Sprague-Dawley rats were assigned to inulin or cellulose treatments for either 4 or 8 weeks. Growth was measured weekly and quality of growth assessed using fat pad weights and dual-energy X-ray absorptiometry (DXA). Whole body (WB) and selected regions were analysed for bone mineral density (BMD) and body composition by DXA. Serum markers of bone turnover were assessed by enzyme-linked immunosorbent assays. Ca and P concentrations were determined in excised femurs by inductively coupled plasma spectrometry. Feeding inulin resulted in 4 % higher femoral weight (adjusted for body weight) and 6 % less feed intake. Inulin did not affect WB or regional BMD, but was associated with a 28 % lower parametrial fat pad mass, 21 % less WB fat mass and 5 % less WB mass. In summary, LC-inulin lowered body fat mass, without consequence to bone density in growing female rats.

Biomechanical analysis of two fixation methods for proximal chevron osteotomy of the first metatarsal.

PubMed

Schuh, Reinhard; Hofstaetter, Jochen Gerhard; Benca, Emir; Willegger, Madeleine; von Skrbensky, Gobert; Zandieh, Shahin; Wanivenhaus, Axel; Holinka, Johannes; Windhager, Reinhard

2014-05-01

The proximal chevron osteotomy provides high correctional power. However, relatively high rates of dorsiflexion malunion of up to 17 % are reported for this procedure. This leads to insufficient weight bearing of the first ray and therefore to metatarsalgia. Recent biomechanical and clinical studies pointed out the importance of rigid fixation of proximal metatarsal osteotomies. Therefore, the aim of the present study was to compare biomechanical properties of fixation of proximal chevron osteotomies with variable locking plate and cancellous screw respectively. Ten matched pairs of human fresh frozen cadaveric first metatarsals underwent proximal chevron osteotomy with either variable locking plate or cancellous screw fixation after obtaining bone mineral density. Biomechanical testing included repetitive plantar to dorsal loading from 0 to 31 N with the 858 Mini Bionix(®) (MTS(®) Systems Corporation, Eden Prairie, MN, USA). Dorsal angulation of the distal fragment was recorded. The variable locking plate construct reveals statistically superior results in terms of bending stiffness and dorsal angulation compared to the cancellous screw construct. There was a statistically significant correlation between bone mineral density and maximum tolerated load until construct failure occurred for the screw construct (r = 0.640, p = 0.406). The results of the present study indicate that variable locking plate fixation shows superior biomechanical results to cancellous screw fixation for proximal chevron osteotomy. Additionally, screw construct failure was related to levels of low bone mineral density. Based on the results of the present study we recommend variable locking plate fixation for proximal chevron osteotomy, especially in osteoporotic bone.

PREVALENCE OF THE FEMALE ATHLETE TRIAD IN HIGH SCHOOL ATHLETES AND SEDENTARY STUDENTS

PubMed Central

Hoch, Anne Z; Pajewski, Nicholas M.; Moraski, LuAnn; Carrera, Guillermo F.; Wilson, Charles R.; Hoffmann, Raymond G.; Schimke, Jane E.; Gutterman, David D.

2009-01-01

Objective To determine the prevalence of the female athlete triad (low energy availability, menstrual dysfunction and low bone mineral density) in high school varsity athletes in a variety of sports compared with sedentary students/controls. Design Prospective study. Setting Academic medical center in the Midwest. Participants Eighty varsity athletes and eighty sedentary students/controls volunteered for this study. Intervention Subjects completed questionnaires, had their blood drawn and underwent bone mineral density testing. Main Outcome Measures Each participant completed screening questionnaires assessing eating behavior, menstrual status and physical activity. Each subject completed a 3-day food diary. Serum hormonal, TSH and prolactin levels were determined. Bone mineral density (BMD) and body composition were measured by dual energy x-ray absorptiometry (DXA). Results Low energy availability was present in similar numbers of athletes (36%) and sedentary/control subjects (39%; p=0.74). Athletes suffered more menstrual abnormalities (54%) compared with sedentary students/controls (21%) (p=<0.001). DXA revealed that 16% of the athletes and 30% of the sedentary/controls had low BMD (p=0.03). Risk factors for reduced BMD include sedentary control student, low BMI and increased caffeine consumption. Conclusions A substantial number of high school athletes (78%) and a surprising number of sedentary students (65%) suffer from one or more components of the triad. Given the high prevalence of triad characteristics in both groups, education in the formative elementary school years has the potential to prevent several of the components in both groups, therefore, improving health and averting long-term complications. PMID:19741317

Comparing the ice nucleation efficiencies of ice nucleating substrates to natural mineral dusts

NASA Astrophysics Data System (ADS)

Steinke, Isabelle; Funk, Roger; Höhler, Kristina; Haarig, Moritz; Hoffmann, Nadine; Hoose, Corinna; Kiselev, Alexei; Möhler, Ottmar; Leisner, Thomas

2014-05-01

Mineral dust particles in the atmosphere may act as efficient ice nuclei over a wide range of temperature and relative humidity conditions. The ice nucleation capability of dust particles mostly depends on the particle surface area and the associated physico-chemical surface properties. It has been observed that the surface-related ice nucleation efficiency of different dust particles and mineral species can vary by several orders of magnitude. However, the relation between aerosol surface properties and observed ice nucleation efficiency is still not completely understood due to the large variability of chemical compositions and morphological features. In order to gain a better understanding of small scale freezing processes, we investigated the freezing of several hundreds of small droplets (V=0.4 nl) deposited on materials with reasonably well defined surfaces such as crystalline silicon wafers, graphite and freshly cleaved mica sheets under atmospherically relevant conditions. These substrates are intended to serve as simple model structures compared to the surface of natural aerosol particles. To learn more about the impact of particle morphology on ice nucleation processes, we also investigated micro-structured silicon wafers with prescribed trenches. The ice nucleation efficiencies deduced from these experiments are expressed as ice nucleation active surface site density values. With this approach, the freezing properties of the above-described substrates could be compared to those of natural mineral dusts such as agricultural soil dusts, volcanic ash and fossil diatoms, which have been investigated in AIDA cloud chamber experiments. All tested ice nucleating substrates were consistently less efficient at nucleating ice than the natural mineral dusts. Crystalline silicon only had a negligible influence on the freezing of small droplets, leading to freezing near the homogeneous freezing temperature threshold. Applying surface structures to silicon led to a shift towards heterogeneous freezing. However, the measured ice nucleation active surface site densities were still smaller than those of mineral dusts.

Dynamic Alterations in Microarchitecture, Mineralization and Mechanical Property of Subchondral Bone in Rat Medial Meniscal Tear Model of Osteoarthritis

PubMed Central

Yu, De-Gang; Nie, Shao-Bo; Liu, Feng-Xiang; Wu, Chuan-Long; Tian, Bo; Wang, Wen-Gang; Wang, Xiao-Qing; Zhu, Zhen-An; Mao, Yuan-Qing

2015-01-01

Background: The properties of subchondral bone influence the integrity of articular cartilage in the pathogenesis of osteoarthritis (OA). However, the characteristics of subchondral bone alterations remain unresolved. The present study aimed to observe the dynamic alterations in the microarchitecture, mineralization, and mechanical properties of subchondral bone during the progression of OA. Methods: A medial meniscal tear (MMT) operation was performed in 128 adult Sprague Dawley rats to induce OA. At 2, 4, 8, and 12 weeks following the MMT operation, cartilage degeneration was evaluated using toluidine blue O staining, whereas changes in the microarchitecture indices and tissue mineral density (TMD), mineral-to-collagen ratio, and intrinsic mechanical properties of subchondral bone plates (BPs) and trabecular bones (Tbs) were measured using micro-computed tomography scanning, confocal Raman microspectroscopy and nanoindentation testing, respectively. Results: Cartilage degeneration occurred and worsened progressively from 2 to 12 weeks after OA induction. Microarchitecture analysis revealed that the subchondral bone shifted from bone resorption early (reduced trabecular BV/TV, trabecular number, connectivity density and trabecular thickness [Tb.Th], and increased trabecular spacing (Tb.Sp) at 2 and 4 weeks) to bone accretion late (increased BV/TV, Tb.Th and thickness of subchondral bone plate, and reduced Tb.Sp at 8 and 12 weeks). The TMD of both the BP and Tb displayed no significant changes at 2 and 4 weeks but decreased at 8 and 12 weeks. The mineral-to-collagen ratio showed a significant decrease from 4 weeks for the Tb and from 8 weeks for the BP after OA induction. Both the elastic modulus and hardness of the Tb showed a significant decrease from 4 weeks after OA induction. The BP showed a significant decrease in its elastic modulus from 8 weeks and its hardness from 4 weeks. Conclusion: The microarchitecture, mineralization and mechanical properties of subchondral bone changed in a time-dependent manner as OA progressed. PMID:26521785

Battling Brittle Bones

NASA Technical Reports Server (NTRS)

2002-01-01

The accuDEXA(R) Bone Mineral Density Assessment System, manufactured by Schick Technologies, Inc., utilizes "camera on a chip" sensor technology invented and developed by NASA's Jet Propulsion Laboratory. Schick's accuDEXA system offers several advantages over traditional osteoporosis tests, which assess bone density loss in the hip and spine, and require specialized personnel to conduct. With accuDEXA, physicians can test the entire body's bone density at a peripheral site, such as the finger, without applying gels or having patients remove garments. Results are achieved in 30 seconds and printed out in less than a minute, compared to the estimated exam time of 15 minutes for hip and spine density analyses. Schick has also applied the CMOS APS technology to a new software product that performs dental radiography using up to 90 percent less radiation exposure than conventional X-rays. Called Computed Dental Radiography(R), the new digital imaging product utilizes an electronic sensor in place of X-ray film to generate sharp and clear images that appear on a computer screen within 3 seconds, and can be enlarged and enhanced to identify problems.

Modeling Earth's surface topography: decomposition of the static and dynamic components

NASA Astrophysics Data System (ADS)

Guerri, M.; Cammarano, F.; Tackley, P. J.

2017-12-01

Isolating the portion of topography supported by mantle convection, the so-called dynamic topography, would give us precious information on vigor and style of the convection itself. Contrasting results on the estimate of dynamic topography motivate us to analyse the sources of uncertainties affecting its modeling. We obtain models of mantle and crust density, leveraging on seismic and mineral physics constraints. We use the models to compute isostatic topography and residual topography maps. Estimates of dynamic topography and associated synthetic geoid are obtained by instantaneous mantle flow modeling. We test various viscosity profiles and 3D viscosity distributions accounting for inferred lateral variations in temperature. We find that the patterns of residual and dynamic topography are robust, with an average correlation coefficient of 0.74 and 0.71, respectively. The amplitudes are however poorly constrained. For the static component, the considered lithospheric mantle density models result in topographies that differ, on average, 720 m, with peaks reaching 1.7 km. The crustal density models produce variations in isostatic topography averaging 350 m, with peaks of 1 km. For the dynamic component, we obtain peak-to-peak topography amplitude exceeding 3 km for all the tested mantle density and viscosity models. Such values of dynamic topography produce geoid undulations that are not in agreement with observations. Assuming chemical heterogeneities in the lower mantle, in correspondence with the LLSVPs (Large Low Shear wave Velocity Provinces), helps to decrease the amplitudes of dynamic topography and geoid, but reduces the correlation between synthetic and observed geoid. The correlation coefficients between the residual and dynamic topography maps is always less than 0.55. In general, our results indicate that, i) current knowledge of crust density, mantle density and mantle viscosity is still limited, ii) it is important to account for all the various sources of uncertainties when computing static and dynamic topography. In conclusion, a multidisciplinary approach, which involves multiple geophysics observations and constraints from mineral physics, is necessary for obtaining robust density models and, consequently, for properly estimating the dynamic topography.

Zinc deficiency reduces bone mineral density in the spine of young adult rats: a pilot study.

PubMed

Ryz, Natasha R; Weiler, Hope A; Taylor, Carla G

2009-01-01

The objective of this study was to investigate the effects of zinc deficiency initiated during adolescence on skeletal densitometry, serum markers of bone metabolism, femur minerals and morphometry in young adult rats. Ten-week-old male rats were fed a <1-mg Zn/kg diet (9ZD), a 5-mg Zn/kg diet (9MZD) or a 30-mg Zn/kg diet (9CTL) for up to 9 weeks. Analyses included bone mineral density, serum osteocalcin and C-terminal peptides of type I collagen, serum zinc, femur zinc, calcium and phosphorus, and femur morphometry. Bone mineral density was 14% lower in the spine of 9ZD, but was not altered in the whole body, tibia or femur, or in any of the aforementioned sites in 9MZD, compared to 9CTL. When adjusted for size, spine bone mineral apparent density was still 8% lower in 9ZD than 9CTL. Serum osteocalcin, a marker for bone formation, was approximately 33% lower in 9ZD compared to both 9MZD and 9CTL. The 9ZD and 9MZD had 57% lower femur zinc and 56-88% lower serum zinc concentrations compared to 9CTL. These findings indicate that severe zinc deficiency initiated during adolescence may have important implications for future bone health, especially with regards to bone consolidation in the spine. 2009 S. Karger AG, Basel.

THE MEASUREMENT OF BONE QUALITY USING GRAY LEVEL CO-OCCURRENCE MATRIX TEXTURAL FEATURES.

PubMed

Shirvaikar, Mukul; Huang, Ning; Dong, Xuanliang Neil

2016-10-01

In this paper, statistical methods for the estimation of bone quality to predict the risk of fracture are reported. Bone mineral density and bone architecture properties are the main contributors of bone quality. Dual-energy X-ray Absorptiometry (DXA) is the traditional clinical measurement technique for bone mineral density, but does not include architectural information to enhance the prediction of bone fragility. Other modalities are not practical due to cost and access considerations. This study investigates statistical parameters based on the Gray Level Co-occurrence Matrix (GLCM) extracted from two-dimensional projection images and explores links with architectural properties and bone mechanics. Data analysis was conducted on Micro-CT images of 13 trabecular bones (with an in-plane spatial resolution of about 50μm). Ground truth data for bone volume fraction (BV/TV), bone strength and modulus were available based on complex 3D analysis and mechanical tests. Correlation between the statistical parameters and biomechanical test results was studied using regression analysis. The results showed Cluster-Shade was strongly correlated with the microarchitecture of the trabecular bone and related to mechanical properties. Once the principle thesis of utilizing second-order statistics is established, it can be extended to other modalities, providing cost and convenience advantages for patients and doctors.

THE MEASUREMENT OF BONE QUALITY USING GRAY LEVEL CO-OCCURRENCE MATRIX TEXTURAL FEATURES

PubMed Central

Shirvaikar, Mukul; Huang, Ning; Dong, Xuanliang Neil

2016-01-01

In this paper, statistical methods for the estimation of bone quality to predict the risk of fracture are reported. Bone mineral density and bone architecture properties are the main contributors of bone quality. Dual-energy X-ray Absorptiometry (DXA) is the traditional clinical measurement technique for bone mineral density, but does not include architectural information to enhance the prediction of bone fragility. Other modalities are not practical due to cost and access considerations. This study investigates statistical parameters based on the Gray Level Co-occurrence Matrix (GLCM) extracted from two-dimensional projection images and explores links with architectural properties and bone mechanics. Data analysis was conducted on Micro-CT images of 13 trabecular bones (with an in-plane spatial resolution of about 50μm). Ground truth data for bone volume fraction (BV/TV), bone strength and modulus were available based on complex 3D analysis and mechanical tests. Correlation between the statistical parameters and biomechanical test results was studied using regression analysis. The results showed Cluster-Shade was strongly correlated with the microarchitecture of the trabecular bone and related to mechanical properties. Once the principle thesis of utilizing second-order statistics is established, it can be extended to other modalities, providing cost and convenience advantages for patients and doctors. PMID:28042512

Association of Adenylate Cyclase 10 (ADCY10) Polymorphisms and Bone Mineral Density in Healthy Adults

PubMed Central

Ichikawa, Shoji; Koller, Daniel L.; Curry, Leah R.; Lai, Dongbing; Xuei, Xiaoling; Edenberg, Howard J.; Hui, Siu L.; Peacock, Munro; Foroud, Tatiana; Econs, Michael J.

2010-01-01

Phenotypic variation in bone mineral density (BMD) among healthy adults is influenced by both genetic and environmental factors. Genetic sequence variations in the adenylate cyclase 10 (ADCY10) gene, which is also called soluble adenylate cyclase, have previously been reported to be associated with low spinal BMD in hypercalciuric patients. Since ADCY10 is located in the region linked to spinal BMD in our previous linkage analysis, we tested whether polymorphisms in this gene are also associated with normal BMD variation in healthy adults. Sixteen single nucleotide polymorphisms (SNPs) distributed throughout ADCY10 were genotyped in two healthy groups of American whites: 1,692 premenopausal women and 715 men. Statistical analyses were performed in the two groups to test for association between these SNPs and femoral neck and lumbar spine areal BMD. We observed significant evidence of association (p<0.01) with one SNP each in men and women. Genotypes at these SNPs accounted for less than 1% of hip BMD variation in men, but 1.5% of spinal BMD in women. However, adjacent SNPs did not corroborate the association in either males or females. In conclusion, we found a modest association between an ADCY10 polymorphism and spinal areal BMD in premenopausal white women. PMID:19093065

Comparison of parameters of bone profile and homocysteine in physically active and non-active postmenopausal females.

PubMed

Tariq, Sundus; Lone, Khalid Parvez; Tariq, Saba

2016-01-01

Optimal physical activity is important in attaining a peak bone mass. Physically active women have better bone mineral density and reduce fracture risk as compared to females living a sedentary life. The objective of this study was to compare parameters of bone profile and serum homocysteine levels in physically active and non-active postmenopausal females. In this cross sectional study postmenopausal females between 50-70 years of age were recruited and divided into two groups: Physically inactive (n=133) performing light physical activity and Physically active (n=34) performing moderate physical activity. Physical activity (in metabolic equivalents), bone mineral density and serum homocysteine levels were assessed. Spearman's rho correlation was applied to observe correlations. Two independent sample t test and Mann Whitney U test were applied to compare groups. P-value ≤ 0.05 was taken statistically significant. Parameters of bone profile were significantly higher and serum homocysteine levels were significantly lower in postmenopausal females performing moderate physical activity as compared to females performing light physical activity. Homocysteine was not significantly related to T-score and Z-score in both groups. Improving physical activity could be beneficial for improving the quality of bone, decreasing fracture risk and decreasing serum homocysteine levels.

Effects of brisk walking on static and dynamic balance, locomotion, body composition, and aerobic capacity in ageing healthy active men.

PubMed

Paillard, T; Lafont, C; Costes-Salon, M C; Rivière, D; Dupui, P

2004-10-01

This work analyses the short-term physiological and neurophysiological effects of a brisk walking programme in ageing, healthy, active men. Twenty-one men 63 to 72 years of age were recruited and separated into 2 groups. One group performed a walking programme (WP) (n = 11) and another served as control (C) group (n = 10). The walking programme lasted for twelve weeks and included five sessions per week. Several parameters were assessed before and after the programme for the WP group. The same tests were performed (separated by twelve weeks) in group C. During each assessment, the subjects were put through static and dynamic balance tests, spatio-temporal gait analysis, body composition measurements and determination of aerobic capacity and bone mineral density. The statistic analysis showed a significant improvement in dynamic balance performance, especially in lateral sway when the subjects kept their eyes open, an increase of VO(2) max and loss of fat mass in the WP group. However, no alterations appeared in spatiotemporal gait characteristics, static balance performance, lean mass or bone mineral density (total body and hip). According to these results, this walking programme may have positive effects on preventing ageing subjects from falling.

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

NASA Astrophysics Data System (ADS)

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.

Association of Circulating Renin and Aldosterone With Osteocalcin and Bone Mineral Density in African Ancestry Families.

PubMed

Kuipers, Allison L; Kammerer, Candace M; Pratt, J Howard; Bunker, Clareann H; Wheeler, Victor W; Patrick, Alan L; Zmuda, Joseph M

2016-05-01

Hypertension is associated with accelerated bone loss, and the renin-angiotensin-aldosterone system is a key regulator of blood pressure. Although components of this system are expressed in human bone cells, studies in humans are sparse. Thus, we studied the association of circulating renin and aldosterone with osteocalcin and bone mineral density. We recruited 373 African ancestry family members without regard to health status from 6 probands (mean family size: 62 and relative pairs: 1687). Participants underwent a clinical examination, dual-energy x-ray absorptiometry, and quantitative computed tomographic scans. Renin activity, aldosterone concentration, and osteocalcin were measured in fasting blood samples. Aldosterone/renin ratio was calculated as aldosterone concentration/renin activity. All models were analyzed using pedigree-based variance components methods. Full models included adjustment for age, sex, body composition, comorbidities, lifestyle factors, blood pressure, and antihypertensive medication. Higher renin activity was significantly associated with lower total osteocalcin and with higher trabecular bone mineral density (both P<0.01). There were also significant genetic correlations between renin activity and whole-body bone mineral density. There were no associations with aldosterone concentration in any model and results for aldosterone/renin ratio were similar to those for renin activity. This is the first study to report a significant association between renin activity and a marker of bone turnover and bone mineral density in generally healthy individuals. Also, there is evidence for significant genetic pleiotropy and, thus, there may be a shared biological mechanism underlying both the renin-angiotensin-aldosterone system and bone metabolism that is independent of hypertension. © 2016 American Heart Association, Inc.

Prenatal stress changes courtship vocalizations and bone mineral density in mice.

PubMed

Schmidt, Michaela; Lapert, Florian; Brandwein, Christiane; Deuschle, Michael; Kasperk, Christian; Grimsley, Jasmine M; Gass, Peter

2017-01-01

Stress during the prenatal period has various effects on social and sexual behavior in both human and animal offspring. The present study examines the effects of chronic restraint stress in the second vs third trimester in pregnancy and glucocorticoid receptor (GR) heterozygous mutation on C57BL/6N male offspring's vocal courtship behavior in adulthood by applying a novel analyzing method. Finally, corticosterone and testosterone levels as well as bone mineral density were measured. Prenatal stress in the third, but not in the second trimester caused a significant qualitative change in males' courtship vocalizations, independent of their GR genotype. Bone mineral density was decreased also by prenatal stress exclusively in the third trimester in GR mutant and wildtype mice and - in contrast to corticosterone and testosterone - highly correlated with courtship vocalizations. In Gr +/- males corticosterone serum levels were significantly increased in animals that had experienced prenatal stress in the third trimester. Testosterone serum levels were overall increased in Gr +/- males in comparison to wildtypes as a tendency - whereas prenatal stress had no influence. Prenatal stress alters adult males' courtship vocalizations exclusively when applied in the third trimester, with closely related changes in bone mineral density. Bone mineral density seems to reflect best the complex neuroendocrine mechanisms underlying the production of courtship vocalizations. Besides, we demonstrated for the first time elevated basal corticosterone levels in Gr +/- males after prenatal stress which suggests that the Gr +/- mouse model of depression might also serve as a model of prenatal stress in male offspring. Copyright © 2016 Elsevier Ltd. All rights reserved.

ASSOCIATION OF CIRCULATING RENIN AND ALDOSTERONE WITH OSTEOCALCIN AND BONE MINERAL DENSITY IN AFRICAN ANCESTRY FAMILIES

PubMed Central

Kuipers, Allison L; Kammerer, Candace M; Howard Pratt, J; Bunker, Clareann H; Wheeler, Victor W; Patrick, Alan L; Zmuda, Joseph M

2016-01-01

Hypertension is associated with accelerated bone loss and the renin-angiotensin-aldosterone system is a key regulator of blood pressure. Although components of this system are expressed in human bone cells, studies in humans are sparse. Thus, we studied the association of circulating renin and aldosterone with osteocalcin and bone mineral density. We recruited 373 African ancestry family members without regard to health status from 6 probands (mean family size: 62; relative pairs: 1687). Participants underwent a clinical exam, dual energy x-ray absorptiometry, and quantitative computed tomography scans. Renin activity, aldosterone concentration, and osteocalcin were measured in fasting blood samples. Aldosterone to renin ratio was calculated as aldosterone concentration/renin activity. All models were analyzed using pedigree-based variance components methods. Full models included adjustment for age, sex, body composition, co-morbidities, lifestyle factors, blood pressure, and antihypertensive medication. Higher renin activity was significantly associated with lower total osteocalcin and with higher trabecular bone mineral density (both p<0.01). There were also significant genetic correlations between renin activity and whole body bone mineral density. There were no associations with aldosterone concentration in any model and results for aldosterone to renin ratio were similar to those for renin activity. This is the first study to report a significant association between renin activity and a marker of bone turnover and bone mineral density in generally healthy individuals. Also, there is evidence for significant genetic pleiotropy and, thus, there may be a shared biologic mechanism underlying both the renin-angiotensin-aldosterone system and bone metabolism that is independent of hypertension. PMID:26975710

[Bone mineral density in overweight and obese adolescents].

PubMed

Cobayashi, Fernanda; Lopes, Luiz A; Taddei, José Augusto de A C

2005-01-01

To study bone density as a concomitant factor for obesity in post-pubertal adolescents, controlling for other variables that may interfere in such a relation. Study comprising 83 overweight and obese adolescents (BMI > or = P85) and 89 non obese ones (P5 < or = BMI < or = P85). Cases and controls were selected out of 1,420 students (aged 14-19) from a public school in the city of São Paulo. The bone mineral density of the lumbar spine (L2-L4 in g/cm2) was assessed by dual-energy x-ray absorptiometry (LUNARtrade mark DPX-L). The variable bone density was dichotomized using 1.194 g/cm2 as cutoff point. Bivariate analyses were conducted considering the prevalence of overweight and obesity followed by multivariate analysis (logistic regression) according to a hierarchical conceptual model. The prevalence of bone density above the median was twice more frequent among cases (69.3%) than among controls (32.1%). In the bivariate analysis such prevalence resulted in an odds ratio (OR) of 4.78. The logistic regression model showed that the association between obesity and mineral density is yet more intense with an OR of 6.65 after the control of variables related to sedentary lifestyle and intake of milk and dairy products. Obese and overweight adolescents in the final stages of sexual maturity presented higher bone mineral density in relation to their normal-weight counterparts; however, cohort studies will be necessary to evaluate the influence of such characteristic on bone resistance in adulthood and, consequently, on the incidence of osteopenia and osteoporosis at older ages.

Bone Mineral Density in Boys Diagnosed with Autism Spectrum Disorder: A Case-Control Study

ERIC Educational Resources Information Center

Barnhill, Kelly; Ramirez, Lucas; Gutierrez, Alan; Richardson, Wendy; Marti, C. Nathan; Potts, Amy; Shearer, Rebeca; Schutte, Claire; Hewitson, Laura

2017-01-01

This study compared bone mineral density (BMD) of the spine obtained by dual-energy X-ray absorptiometry (DEXA), nutritional status, biochemical markers, and gastrointestinal (GI) symptoms in 4-8 year old boys with Autism Spectrum Disorder (ASD) with a group of age-matched, healthy boys without ASD. Boys with ASD had significantly lower spine BMD…

Bone Mineral Density in Adults With Down Syndrome, Intellectual Disability, and Nondisabled Adults

ERIC Educational Resources Information Center

Geijer, Justin R.; Stanish, Heidi I.; Draheim, Christopher C.; Dengel, Donald R.

2014-01-01

Individuals with intellectual disability (ID) or Down syndrome (DS) may be at greater risk of osteoporosis. The purpose of this study was to compare bone mineral density (BMD) of DS, ID, and non-intellectually disabled (NID) populations. In each group, 33 participants between the ages of 28 and 60 years were compared. BMD was measured with…

Effects of Physical Training and Calcium Intake on Bone Mineral Density of Students with Mental Retardation

ERIC Educational Resources Information Center

Hemayattalab, Rasool

2010-01-01

The purpose of this study was to investigate the effects of physical training and calcium intake on bone mineral density (BMD) of students with mental retardation. Forty mentally retarded boys (age 7-10 years old) were randomly assigned to four groups (no differences in age, BMD, calcium intake and physical activity): training groups with or…

Differential controls on soil carbon density and mineralization among contrasting forest types in a temperate forest ecosystem.

PubMed

You, Ye-Ming; Wang, Juan; Sun, Xiao-Lu; Tang, Zuo-Xin; Zhou, Zhi-Yong; Sun, Osbert Jianxin

2016-03-01

Understanding the controls on soil carbon dynamics is crucial for modeling responses of ecosystem carbon balance to global change, yet few studies provide explicit knowledge on the direct and indirect effects of forest stands on soil carbon via microbial processes. We investigated tree species, soil, and site factors in relation to soil carbon density and mineralization in a temperate forest of central China. We found that soil microbial biomass and community structure, extracellular enzyme activities, and most of the site factors studied varied significantly across contrasting forest types, and that the associations between activities of soil extracellular enzymes and microbial community structure appeared to be weak and inconsistent across forest types, implicating complex mechanisms in the microbial regulation of soil carbon metabolism in relation to tree species. Overall, variations in soil carbon density and mineralization are predominantly accounted for by shared effects of tree species, soil, microclimate, and microbial traits rather than the individual effects of the four categories of factors. Our findings point to differential controls on soil carbon density and mineralization among contrasting forest types and highlight the challenge to incorporate microbial processes for constraining soil carbon dynamics in global carbon cycle models.

Differential controls on soil carbon density and mineralization among contrasting forest types in a temperate forest ecosystem

PubMed Central

You, Ye-Ming; Wang, Juan; Sun, Xiao-Lu; Tang, Zuo-Xin; Zhou, Zhi-Yong; Sun, Osbert Jianxin

2016-01-01

Understanding the controls on soil carbon dynamics is crucial for modeling responses of ecosystem carbon balance to global change, yet few studies provide explicit knowledge on the direct and indirect effects of forest stands on soil carbon via microbial processes. We investigated tree species, soil, and site factors in relation to soil carbon density and mineralization in a temperate forest of central China. We found that soil microbial biomass and community structure, extracellular enzyme activities, and most of the site factors studied varied significantly across contrasting forest types, and that the associations between activities of soil extracellular enzymes and microbial community structure appeared to be weak and inconsistent across forest types, implicating complex mechanisms in the microbial regulation of soil carbon metabolism in relation to tree species. Overall, variations in soil carbon density and mineralization are predominantly accounted for by shared effects of tree species, soil, microclimate, and microbial traits rather than the individual effects of the four categories of factors. Our findings point to differential controls on soil carbon density and mineralization among contrasting forest types and highlight the challenge to incorporate microbial processes for constraining soil carbon dynamics in global carbon cycle models. PMID:26925871

Total body composition by dual-photon (153Gd) absorptiometry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mazess, R.B.; Peppler, W.W.; Gibbons, M.

1984-10-01

The lean-fat composition (%FATR) of soft tissue and the mineral mass of the skeleton were determined in vivo using dual-photon (153Gd) absorptiometry (dose under 2 mrem). A rectilinear raster scan was made over the entire body in 18 subjects (14 female, 4 male). Single-photon absorptiometry (125I) measured bone mineral content on the radius. Percentage fat (%FATD) was determined in the same subjects using body density (from underwater weighing with correction for residual lung volume). Lean body mass (LBM) was determined using both %FATR and %FATD. Percentage fat from absorptiometry and from underwater density were correlated (r . 0.87). The deviationmore » of %FATD from %FATR was due to the amount of skeletal mineral as a percentage of the LBM (r . 0.90). Therefore, skeletal variability, even in normal subjects, where mineral ranges only from 4 to 8% of the LBM, essentially precludes use of body density as a composition indicator unless skeletal mass is measured. Anthropometry (fatfolds and weight) predicted %FATR and LBM at least as well as did underwater density. The predictive error of %FATR from fatfolds was 5% while the predictive error in predicting LBM from anthropometry was 2 to 3 kg (3%).« less

Temporal and spatial distribution of alteration, mineralization and fluid inclusions in the transitional high-sulfidation epithermal-porphyry copper system at Red Mountain, Arizona

USGS Publications Warehouse

Lecumberri-Sanchez, Pilar; Newton, M. Claiborne; Westman, Erik C.; Kamilli, Robert J.; Canby, Vertrees M.; Bodnar, Robert J.

2013-01-01

Red Mountain, Arizona, is a Laramide porphyry Cu system (PCD) that has experienced only a modest level of erosion compared to most other similar deposits in the southwestern United States. As a result, the upper portion of the magmatic–hydrothermal system, which represents the transition from shallower high-sulfidation epithermal mineralization to deeper porphyry Cu mineralization, is well preserved. Within the Red Mountain system, alteration, mineralization and fluid inclusion assemblages show a systematic distribution in both time and space. Early-potassic alteration (characterized by the minerals biotite and magnetite) is paragenetically earlier than late-potassic alteration (K-feldspar–anhydrite) and both are followed by later phyllic (sericite–pyrite) alteration. Advanced argillic alteration (pyrophyllite–alunite–other clay minerals) is thought to be coeval with or postdate phyllic alteration. Minerals characteristic of advanced argillic alteration are present in the near surface. Phyllic alteration extends to greater depths compared to advanced argillic alteration. Early-potassic and late-potassic alteration are only observed in the deepest part of the system. Considerable overlap of phyllic alteration with both early-potassic and late-potassic alteration zones is observed. The hypogene mineralization contains 0.4–1.2% Cu and is spatially and temporally related to the late-potassic alteration event. Molybdenum concentration is typically In the deepest part of the system, an early generation of low-to-moderate density and salinity liquid + vapor inclusions with opaque daughter minerals is followed in time by halite-bearing inclusions that also contain opaque daughter minerals indicating that an early intermediate-density magmatic fluid evolved to a high-density, high-salinity mineralizing fluid. The increase in density and salinity of fluids with time observed in the deeper parts of the system may be the result of immiscibility (“boiling”) of the earlier magmatic fluids or may reflect the compositional evolution of fluids that exsolved from the magma. Trails of inclusions consisting of only vapor-rich inclusions are common in the shallow parts of the system, and are associated with advanced argillic alteration, suggesting that intense boiling (“flashing”) occurred at (or below) this level. Fluid inclusion assemblages consisting of coexisting vapor-rich and halite-bearing inclusions are observed in samples extending from the surface to the upper part of the late-potassic zone, indicating that fluid immiscibility occurred within this depth interval.

The bone mineral content alterations in pediatric patients medicated with levetiracetam, valproic acid, and carbamazepine.

PubMed

Serin, Hepsen Mine; Koç, Zehra Pınar; Temelli, Berfin; Esen, İhsan

2015-10-01

The negative effect of antiepileptic drugs on bone health has been previously documented. However, which antiepileptic drug is safer in regard to bone health is still questionable. Our aims were to investigate the bone mineral density alterations in pediatric patients who receive antiepileptic medication for a minimum of two years and to compare the results of these drugs. Fifty-nine patients (32 males, 27 females; mean age: 8.6±4.6years) and a control group (13 males, 7 females; mean age: 7.6±3.3years) were included in the study. The patients were receiving necessarily the same antiepileptic drugs (AEDs) for at least two years, and none of the patients had mental retardation or cerebral palsy. The patients were divided into three groups: group 1 (patients receiving levetiracetam (LEV), n=20), group 2 (patients receiving carbamazepine (CBZ), n=11), and group 3 (patients receiving valproic acid (VPA), n=28). Plasma calcium (Ca), phosphorus (P), parathyroid hormone (PTH), alkaline phosphatase (ALP), vitamin D levels, and bone mineral density (BMD) values of femur and vertebras (L1-4) and z-scores (comparative results of BMD values of the patients with the age- and gender-matched controls in device database) of the groups were compared. The differences between P, PTH, ALP and age, Ca and BMD results, and vitamin D levels of the patients in all four groups was not statistically significant according to Kruskal-Wallis test (p>0.05). The z-score levels of all the patient and control groups were also not statistically significantly different compared with each other. In contrast to previous reports in pediatric patients, our study has documented that there is not a considerable bone loss in patients receiving long-term AED medication. Although levetiracetam has been proposed as bone-protecting medication, we did not observe any difference between AEDs regarding bone mineral density after two years of treatment. Copyright © 2015 Elsevier Inc. All rights reserved.

Meta-analysis of genome-wide studies identifies WNT16 and ESR1 SNPs associated with bone mineral density in premenopausal women.

PubMed

Koller, Daniel L; Zheng, Hou-Feng; Karasik, David; Yerges-Armstrong, Laura; Liu, Ching-Ti; McGuigan, Fiona; Kemp, John P; Giroux, Sylvie; Lai, Dongbing; Edenberg, Howard J; Peacock, Munro; Czerwinski, Stefan A; Choh, Audrey C; McMahon, George; St Pourcain, Beate; Timpson, Nicholas J; Lawlor, Debbie A; Evans, David M; Towne, Bradford; Blangero, John; Carless, Melanie A; Kammerer, Candace; Goltzman, David; Kovacs, Christopher S; Prior, Jerilynn C; Spector, Tim D; Rousseau, Francois; Tobias, Jon H; Akesson, Kristina; Econs, Michael J; Mitchell, Braxton D; Richards, J Brent; Kiel, Douglas P; Foroud, Tatiana

2013-03-01

Previous genome-wide association studies (GWAS) have identified common variants in genes associated with variation in bone mineral density (BMD), although most have been carried out in combined samples of older women and men. Meta-analyses of these results have identified numerous single-nucleotide polymorphisms (SNPs) of modest effect at genome-wide significance levels in genes involved in both bone formation and resorption, as well as other pathways. We performed a meta-analysis restricted to premenopausal white women from four cohorts (n = 4061 women, aged 20 to 45 years) to identify genes influencing peak bone mass at the lumbar spine and femoral neck. After imputation, age- and weight-adjusted bone-mineral density (BMD) values were tested for association with each SNP. Association of an SNP in the WNT16 gene (rs3801387; p = 1.7 × 10(-9) ) and multiple SNPs in the ESR1/C6orf97 region (rs4870044; p = 1.3 × 10(-8) ) achieved genome-wide significance levels for lumbar spine BMD. These SNPs, along with others demonstrating suggestive evidence of association, were then tested for association in seven replication cohorts that included premenopausal women of European, Hispanic-American, and African-American descent (combined n = 5597 for femoral neck; n = 4744 for lumbar spine). When the data from the discovery and replication cohorts were analyzed jointly, the evidence was more significant (WNT16 joint p = 1.3 × 10(-11) ; ESR1/C6orf97 joint p = 1.4 × 10(-10) ). Multiple independent association signals were observed with spine BMD at the ESR1 region after conditioning on the primary signal. Analyses of femoral neck BMD also supported association with SNPs in WNT16 and ESR1/C6orf97 (p < 1 × 10(-5) ). Our results confirm that several of the genes contributing to BMD variation across a broad age range in both sexes have effects of similar magnitude on BMD of the spine in premenopausal women. These data support the hypothesis that variants in these genes of known skeletal function also affect BMD during the premenopausal period. Copyright © 2013 American Society for Bone and Mineral Research.

[INVESTIGATION OF THE LEVEL OF MINERAL DENSITY OF SKELETAL OSSEOUS TISSUE IN PATIENTS WITH PERIODONTAL TISSUE DISEASES].

PubMed

Hodovana, O I

2015-01-01

Results of investigation of mineral density condition of skeletal osseous tissue in patients with inflammatory and dystrophic-inflammatory diseases of periodontal tissues with ultrasound densitometry method have been presented. Various changes of osseous tissue of skeletal bones have been detected: osteopenia, osteoporosis and osteosclerosis, which correlated with the severity of pathological process in periodontium. Analysis of the obtained results has been carried out depending on patients' sex as well as form and severity degree of the course of periodontal diseases. It has been established that the peak of detected impairments of mineral density in the skeleton is due to osteopenia, the degree of severity of which deteriorates with the severity of pathological process in periodontal tissues, especially in women.

Effects of ethnicity and vitamin D supplementation on vitamin D status and changes in bone mineral content in infants

USDA-ARS?s Scientific Manuscript database

To evaluate the effects on serum 25(OH)D and bone mineralization of supplementation of breast-fed Hispanic and non-Hispanic Caucasian infants with vitamin D in infants in Houston, Texas. We measured cord serum 25(OH)D levels, bone mineral content (BMC), bone mineral density (BMD) and their changes o...

Effect of dexamethasone on mandibular bone biomechanics in rats during the growth phase as assessed by bending test and peripheral quantitative computerized tomography.

PubMed

Bozzini, Clarisa; Champin, Graciela; Alippi, Rosa M; Bozzini, Carlos E

2015-04-01

Long-term glucocorticoid administration to growing rats induces osteopenia and alterations in the biomechanical behavior of the bone. This study was performed to estimate the effects of dexamethasone (DTX), a synthetic steroid with predominant glucocorticoid activity, on the biomechanical properties of the mandible of rats during the growth phase, as assessed by bending test and peripheral quantitative computed tomographic (pQCT) analysis. The data obtained by the two methods will provide more precise information when analyzed together than separately. Female rats aged 23 d (n=7) received 500μg.kg-1 per day of DXT for 4 weeks. At the end of the treatment period, their body weight and body length were 51.3% and 20.6% lower, respectively, than controls. Hemimandible weight and area (an index of mandibular size) were 27.3% and 9.7% lower, respectively. The right hemimandible of each animal was subjected to a mechanical 3-point bending test. Significant weakening of the bone, as shown by a correlative impairment of strength and stiffness, was observed in experimental rats. Bone density and cross-sectional area were measured by pQCT. Cross-sectional, cortical and trabecular areas were reduced by 20% to 30% in the DTX group, as were other cortical parameters, including the bone density, mineral content and cross-sectional moment of inertia. The "bone strength index" (BSI, the product of the pQCT-assessed xCSMI and vCtBMD) was 56% lower in treated rats, which compares well with the 54% and 52% reduction observed in mandibular strength and stiffness determined through the bending test. Data suggest that the corticosteroid exerts a combined, negative action on bone geometry (mass and architecture) and volumetric bone mineral density of cortical bone, which would express independent effects on both cellular (material quality) and tissue (cross-sectional design) levels of biological organization of the skeleton in the species.

Analysis of LCT-13910 genotypes and bone mineral density in ancient skeletal materials.

PubMed

Mnich, Barbara; Spinek, Anna Elżbieta; Chyleński, Maciej; Sommerfeld, Aleksandra; Dabert, Miroslawa; Juras, Anna; Szostek, Krzysztof

2018-01-01

The relation of LCT-13910 genotypes and bone mineral density (BMD) has been the subject of modern-day human population studies, giving inconsistent results. In the present study we analyze for the first time a relation of LCT-13910 genotypes and BMD in historical skeletal individuals. Ancient population might be a model for testing this association due to elimination of non-natural factors affecting bone density. Among 22 medieval individuals from Sanok churchyard (South-Eastern Poland; dated from XIV to XVII c. AD) we identified 4 individuals with osteoporosis (mean BMD = 0.468 g/cm2, SD = 0.090), 10 individuals with osteopenia (mean BMD = 0.531 g/cm2, SD = 0.066) and 8 individuals with normal BMD values (mean BMD = 0,642 g/cm2, SD = 0.060). Analyses of BMD and LCT-13910 genotypes revealed that mean BMD was the highest (0.583 g/cm2, SD = 0.065) in the individuals with lactose tolerance genotypes (TT and CT). We also found possible association of lower BMD at the radius and CC genotypes due to higher but not statistically significant frequency of osteoporosis in the lactose intolerant group (p = 0.60). Statistically significant correlation was found between BMD and females aged 20-35 years, with tendency to reduce BMD with age (p = 0.02).

Bone benefits of testosterone replacement therapy in male hypogonadism.

PubMed

Tirabassi, G; Biagioli, A; Balercia, G

2014-06-01

Osteoporosis is an asymptomatic, systemic bone disease characterized by low bone mass and microarchitectural deterioration of bone tissue, resulting in increased bone fragility. Such condition is often underdiagnosed and undertreated, especially in men, therefore considerably increasing the fracture risk. Of note, fracture-related morbidity and mortality is generally higher in men, partly due to greater frailty. On the other hand, male hypogonadism is defined as the failure of the testes to produce androgens, sperm, or both and it is often due to the ageing process. This disorder, in turn, causes many systemic disorders, and it is the condition mainly associated with male osteoporosis. Testosterone replacement therapy (TRT) is usually prescribed to restore optimal hormone levels, but conflicting data are available about the efficacy of TRT treatment on bone mineral density. In this review we extensively examined literature data about the usefulness of TRT in improving hypogonadism-associated low bone mineral density. Furthermore, we considered the complex relationship between male osteoporosis and hypogonadism, by specifically addressing the role of androgens in male bone physiology and the diagnostic approach to male osteoporosis and hypogonadism and also by dealing with some new related aspects such as the new endocrine pathways between bone and testis and the role of androgen receptor CAG polymorphism on bone density.

Assessment of the geoavailability of trace elements from selected zinc minerals

USGS Publications Warehouse

Driscoll, Rhonda L.; Hageman, Phillip L.; Benzel, William M.; Diehl, Sharon F.; Morman, Suzette; Choate, LaDonna M.; Lowers, Heather

2014-01-01

This assessment focused on five zinc-bearing minerals. The minerals were subjected to a number of analyses including quantitative X-ray diffraction, optical microscopy, leaching tests, and bioaccessibility and toxicity studies. Like a previous comprehensive assessment of five copper-bearing minerals, the purpose of this assessment was to obtain structural and chemical information and to characterize the reactivity of each mineral to various simulated environmental and biological conditions. As in the copper minerals study, analyses were conducted consistent with widely accepted methods. Unless otherwise noted, analytical methods used for this study were identical to those described in the investigation of copper-bearing minerals. Two sphalerite specimens were included in the zinc-minerals set. One sphalerite was recovered from a mine in Balmat, New York; the second came from a mine in Creede, Colorado. The location and conditions of origin are significant because, as analyses confirmed, the two sphalerite specimens are quite different. For example, data acquired from a simulated gastric fluid (SGF) study indicate that the hydrothermally formed Creede sphalerite contains orders of magnitude higher arsenic, cadmium, manganese, and lead than the much older metamorphic Balmat sphalerite. The SGF and other experimental results contained in this report suggest that crystallizing conditions such as temperature, pressure, fluidization, or alteration processes significantly affect mineral properties—properties that, in turn, influence reactivity, solubility, and toxicity. The three remaining minerals analyzed for this report—smithsonite, hemimorphite, and hydrozincite—are all secondary minerals or alteration products of zinc-ore deposits. In addition, all share physical characteristics such as tenacity, density, streak, and cleavage. Similarities end there. The chemical composition, unit-cell parameters, acid-neutralizing potential, and other observable and quantifiable properties indicate very different minerals. Only one of each of these minerals was studied. Had this assessment included multiples of these minerals, geochemical and mineralogical distinctions would have emerged, similar to the results for the two sphalerite specimens.

Antiphase domains and reverse thermoremanent magnetism in ilmenite-hematite minerals

USGS Publications Warehouse

Lawson, C.A.; Nord, G.L.; Dowty, Eric; Hargraves, R.B.

1981-01-01

Examination of synthetic ilmenite-hematite samples by transmission electron microscopy has for the first time revealed the presence of well-defined antiphase domains and antiphase domain boundaries in this mineral system. Samples quenched from 1300??C have a high density of domain boundaries, whereas samples quenched from 900??C have a much lower density. Only the high-temperature samples acquire reverse thermoremanent magnetism when cooled in an applied magnetic field. The presence of a high density of domain boundaries seems to be a necessary condition for the acquisition of reverse thermoremanent magnetism.

Body composition, adipokines, bone mineral density and bone remodeling markers in relation to IGF-1 levels in adults with Prader-Willi syndrome.

PubMed

van Nieuwpoort, I Caroline; Twisk, Jos W R; Curfs, Leopold M G; Lips, Paul; Drent, Madeleine L

2018-01-01

In patients with Prader-Willi syndrome (PWS) body composition is abnormal and alterations in appetite regulating factors, bone mineral density and insulin-like growth factor-1 (IGF-1) levels have been described. Studies in PWS adults are limited. In this study, we investigated body composition, appetite regulating peptides, bone mineral density and markers of bone remodeling in an adult PWS population. Furthermore, we investigated the association between these different parameters and IGF-1 levels because of the described similarities with growth hormone deficient patients. In this cross-sectional observational cohort study in a university hospital setting we studied fifteen adult PWS patients. Anthropometric and metabolic parameters, IGF-1 levels, bone mineral density and bone metabolism were evaluated. The homeostasis model assessment of insulin resistance (HOMA2-IR) was calculated. Fourteen healthy siblings served as a control group for part of the measurements. In the adult PWS patients, height, fat free mass, IGF-1 and bone mineral content were significantly lower when compared to controls; body mass index (BMI), waist, waist-to-hip ratio and fat mass were higher. There was a high prevalence of osteopenia and osteoporosis in the PWS patients. Also, appetite regulating peptides and bone remodelling markers were aberrant when compared to reference values. Measurements of body composition were significantly correlated to appetite regulating peptides and high-sensitive C-reactive protein (hs-CRP), furthermore HOMA was correlated to BMI and adipokines. In adults with Prader-Willi syndrome alterations in body composition, adipokines, hs-CRP and bone mineral density were demonstrated but these were not associated with IGF-1 levels. Further investigations are warranted to gain more insight into the exact pathophysiology and the role of these alterations in the metabolic and cardiovascular complications seen in PWS, so these complications can be prevented or treated as early as possible.

Vitamin D3 supplementation increases spine bone mineral density in adolescents and young adults with HIV infection being treated with tenofovir disoproxil fumarate: a randomized, placebo controlled trial

USDA-ARS?s Scientific Manuscript database

Background: Tenofovir disoproxil fumarate (TDF) decreases bone mineral density (BMD). We hypothesized vitamin D3 (VITD3) would increase BMD in adolescents/young adults receiving TDF. Methods: Randomized double-blind placebo-controlled trial of directly observed VITD3 50,000 IU vs. placebo every 4 ...

DMPA's effect on bone mineral density: A particular concern for adolescents.

PubMed

Schrager, Sarina B

2009-05-01

Discuss the potential for decreased bone mineral density in using depot-medroxyprogesterone acetate (DMPA) with any woman who is thinking of it as a means of contraception. Recommend to women that they take 1300 mg of calcium and 400 IU of vitamin D when using DMPA. Consider prescribing estrogen replacement if DMPA is going to be used for more than 2 years.

Effect of weightlessness on mineral saturation of bone tissue

NASA Technical Reports Server (NTRS)

Krasnykh, I. G.

1975-01-01

X-ray photometry of bone density established dynamic changes in mineral saturation of bone tissues for Soyuz spacecraft and Salyut orbital station crews. Calcaneus optical bone densities in all crew members fell below initial values; an increase in spacecrew exposure time to weightlessness conditions also increased the degree of decalcification. Demineralization under weightlessness conditions took place at a higher rate than under hypodynamia.

Bone Mineral Density Accrual in Students with Autism Spectrum Disorders: Effects of Calcium Intake and Physical Training

ERIC Educational Resources Information Center

Goodarzi, Mahmood; Hemayattalab, Rasool

2012-01-01

The purpose of this study was to investigate the effects of weight bearing exercise and calcium intake on bone mineral density (BMD) of students with autism spectrum disorders. For this reason 60 boy students with autism disorder (age 8-10 years old) were assigned to four groups with no differences in age, BMD, calcium intake, and physical…

Plasma phosphatidylcholine concentrations of polyunsaturated fatty acids are differentially associated with hop bone mineral density and hip fracture in older adults: The Framingham Osteoporosis Study

USDA-ARS?s Scientific Manuscript database

Polyunsaturated fatty acids (PUFA) may influence bone health. Our objective was to examine associations between plasma phosphatidylcholine (PC) PUFA concentrations and hip measures: 1) femoral neck bone mineral density (FN-BMD) (n=765); 2) 4-y change in FN-BMD (n=556); and 3) hip fracture risk (n=76...

Bone Mineral Density and Respiratory Muscle Strength in Male Individuals with Mental Retardation (with and without Down Syndrome)

ERIC Educational Resources Information Center

da Silva, Vinicius Zacarias Maldaner; Barros, Jonatas de Franca; de Azevedo, Monique; de Godoy, Jose Roberto Pimenta; Arena, Ross; Cipriano, Gerson, Jr.

2010-01-01

The purpose of this study was to assess the respiratory muscle strength (RMS) in individuals with mental retardation (MR), with or without Down Syndrome (DS), and its association with bone mineral density (BMD). Forty-five male individuals (15 with DS, 15 with mental retardation (MR) and 15 apparently healthy controls), aged 20-35, participated in…

Evaluation of bone mineral density in children receiving carbamazepine or valproate monotherapy.

PubMed

Chou, I-Jun; Lin, Kuang-Lin; Wang, Huei-Shyong; Wang, Chao-Jan

2007-01-01

Antiepileptic drugs have been shown to be associated with a lowering of bone mineral density in childhood and adolescence, which are critical periods of skeletal mineralization. A lower peak bone mass attained at the end of adolescence is associated with greater involutional osteoporosis and risk for fracture in the elderly. Our purpose was to evaluate the effects of carbamazepine and valproate monotherapy on bone mineral density in children in Taiwan. From November 1995 to April 2005, forty-two children with uncomplicated epilepsy, who were treated with either carbamazepine (n=21) or valproate (n=21) monotherapy for more than 6 months, were enrolled in this study. All subjects were 5 to 18 years of age, seizure-free for 5 months or more, with normal daily activity, and normal diet. Lumbar bone mineral density of L1 to L4 was measured by dual-energy X-ray absorptiometry. The mean serum levels of carbamazepine and valproate were 5.12 +/- 2.15 mcg/ml and 49.61 +/- 20.84 mcg/ml, respectively. Treatment durations were 37.05 +/- 31.11 months and 22.86 +/- 18.84 months, respectively. The serum levels of calcium and phosphate in both groups were within therapeutic range. The serum level of alkaline phosphatase was significantly higher in the carbamazepine group (264.71 +/- 66.91, U/L) than in the valproate group (179.48 +/- 79.37, U/L). Three patients (140%) had bone mineral density Z-score of -2.0 or lower in the carbamazepine-treated group, but none in the valproate-treated group (p=0.232). Comparing the Z-score in carbamazapine- and valproate-monotherapy children, 7 (33%) had Z-score of -1.5 or lower in the carbamazepine-treated group, and none in the valporate-treated group had Z-score of -1.5 or lower (p=0.009). Four (57%) patients in the 7 carbamazepine-treated children with Z-score of -1.5 or lower had serum drug level lower than therapeutic range. Children receiving carbarmazepine monotherapy had increased frequency of lower bone density than children receiving valproate monotherapy.

Individualized Fracture Risk Feedback and Long-term Benefits After 10 Years.

PubMed

Wu, Feitong; Wills, Karen; Laslett, Laura L; Riley, Malcolm D; Oldenburg, Brian; Jones, Graeme; Winzenberg, Tania

2018-02-01

This study aimed to determine if beneficial effects of individualized feedback of fracture risk on osteoporosis preventive behaviors and bone mineral density observed in a 2-year trial were sustained long-term. This was a 10-year follow-up of a 2-year RCT in 470 premenopausal women aged 25-44 years, who were randomized to one of two educational interventions (the Osteoporosis Prevention and Self-Management Course [OPSMC] or an osteoporosis information leaflet) and received tailored feedback of their relative risk of fracture in later life (high versus normal risk groups). Bone mineral density of lumbar spine and femoral neck were measured by dual-energy X-ray absorptiometry. Physical activity, dietary calcium intake, calcium and vitamin D supplements, and smoking status were measured by questionnaires. From 2 to 12 years, the high-risk group had a smaller decrease in femoral neck bone mineral density (β=0.023, 95% CI=0.005, 0.041 g/cm 2 ) but similar lumbar spine bone mineral density change as the normal-risk group. They were more likely to use calcium (relative risk=1.66, 95% CI=1.22, 2.24) and vitamin D supplements (1.99, 95% CI=1.27, 3.11). The OPSMC had no effects on bone mineral density change. Both high-risk (versus normal-risk) and the OPSMC groups (versus leaflet) had a more favorable pattern of smoking behavior change (relative risk=1.85, 95% CI=0.70, 4.89 and relative risk=2.27, 95% CI=0.86, 6.01 for smoking cessation; relative risk=0.33, 95% CI=0.13, 0.80 and relative risk=0.28, 95% CI=0.10, 0.79 for commenced or persistent smoking). Feedback of high fracture risk to younger women was associated with long-term improvements in osteoporosis preventive behaviors and attenuated femoral neck bone mineral density loss. Therefore, this could be considered as a strategy to prevent osteoporosis. Australian New Zealand Clinical Trials Registry (ANZCTR) NCT00273260. Copyright © 2018 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

Low serum and bone vitamin K status in patients with longstanding Crohn's disease: another pathogenetic factor of osteoporosis in Crohn's disease?

PubMed Central

Schoon, E; Muller, M; Vermeer, C; Schurgers, L; Brummer, R; Stockbrugger, R

2001-01-01

BACKGROUND—A high prevalence of osteoporosis is reported in Crohn's disease. The pathogenesis is not completely understood but is probably multifactorial. Longstanding Crohn's disease is associated with a deficiency of fat soluble vitamins, among them vitamin K. Vitamin K is a cofactor in the carboxylation of osteocalcin, a protein essential for calcium binding to bone. A high level of circulating uncarboxylated osteocalcin is a sensitive marker of vitamin K deficiency.
AIMS—To determine serum and bone vitamin K status in patients with Crohn's disease and to elucidate its relationship with bone mineral density.
METHODS—Bone mineral density was measured in 32 patients with longstanding Crohn's disease and small bowel involvement, currently in remission, and receiving less than 5 mg of prednisolone daily. Serum levels of vitamins D and K, triglycerides, and total immunoreactive osteocalcin, as well as uncarboxylated osteocalcin ("free" osteocalcin) were determined. The hydroxyapatite binding capacity of osteocalcin was calculated. Data were compared with an age and sex matched control population.
RESULTS—Serum vitamin K levels of CD patients were significantly decreased compared with normal controls (p<0.01). "Free" osteocalcin was higher and hydroxyapatite binding capacity of circulating osteocalcin was lower than in matched controls (p<0.05 and p<0.001, respectively), indicating a low bone vitamin K status in Crohn's disease. In patients, an inverse correlation was found between "free" osteocalcin and lumbar spine bone mineral density (r=−0.375, p<0.05) and between "free" osteocalcin and the z score of the lumbar spine (r=−0.381, p<0.05). Multiple linear regression analysis showed that "free" osteocalcin was an independent risk factor for low bone mineral density of the lumbar spine whereas serum vitamin D was not.
CONCLUSIONS—The finding that a poor vitamin K status is associated with low bone mineral density in longstanding Crohn's disease may have implications for the prevention and treatment of osteoporosis in this disorder.


Keywords: Crohn's disease; bone mineral density; vitamin K; osteocalcin PMID:11247890

Multiple Small Diameter Drillings Increase Femoral Neck Stability Compared with Single Large Diameter Femoral Head Core Decompression Technique for Avascular Necrosis of the Femoral Head.

PubMed

Brown, Philip J; Mannava, Sandeep; Seyler, Thorsten M; Plate, Johannes F; Van Sikes, Charles; Stitzel, Joel D; Lang, Jason E

2016-10-26

Femoral head core decompression is an efficacious joint-preserving procedure for treatment of early stage avascular necrosis. However, postoperative fractures have been described which may be related to the decompression technique used. Femoral head decompressions were performed on 12 matched human cadaveric femora comparing large 8mm single bore versus multiple 3mm small drilling techniques. Ultimate failure strength of the femora was tested using a servo-hydraulic material testing system. Ultimate load to failure was compared between the different decompression techniques using two paired ANCOVA linear regression models. Prior to biomechanical testing and after the intervention, volumetric bone mineral density was determined using quantitative computed tomography to account for variation between cadaveric samples and to assess the amount of bone disruption by the core decompression. Core decompression, using the small diameter bore and multiple drilling technique, withstood significantly greater load prior to failure compared with the single large bore technique after adjustment for bone mineral density (p< 0.05). The 8mm single bore technique removed a significantly larger volume of bone compared to the 3mm multiple drilling technique (p< 0.001). However, total fracture energy was similar between the two core decompression techniques. When considering core decompression for the treatment of early stage avascular necrosis, the multiple small bore technique removed less bone volume, thereby potentially leading to higher load to failure.

Classification of mineral deposits into types using mineralogy with a probabilistic neural network

USGS Publications Warehouse

Singer, Donald A.; Kouda, Ryoichi

1997-01-01

In order to determine whether it is desirable to quantify mineral-deposit models further, a test of the ability of a probabilistic neural network to classify deposits into types based on mineralogy was conducted. Presence or absence of ore and alteration mineralogy in well-typed deposits were used to train the network. To reduce the number of minerals considered, the analyzed data were restricted to minerals present in at least 20% of at least one deposit type. An advantage of this restriction is that single or rare occurrences of minerals did not dominate the results. Probabilistic neural networks can provide mathematically sound confidence measures based on Bayes theorem and are relatively insensitive to outliers. Founded on Parzen density estimation, they require no assumptions about distributions of random variables used for classification, even handling multimodal distributions. They train quickly and work as well as, or better than, multiple-layer feedforward networks. Tests were performed with a probabilistic neural network employing a Gaussian kernel and separate sigma weights for each class and each variable. The training set was reduced to the presence or absence of 58 reported minerals in eight deposit types. The training set included: 49 Cyprus massive sulfide deposits; 200 kuroko massive sulfide deposits; 59 Comstock epithermal vein gold districts; 17 quartzalunite epithermal gold deposits; 25 Creede epithermal gold deposits; 28 sedimentary-exhalative zinc-lead deposits; 28 Sado epithermal vein gold deposits; and 100 porphyry copper deposits. The most common training problem was the error of classifying about 27% of Cyprus-type deposits in the training set as kuroko. In independent tests with deposits not used in the training set, 88% of 224 kuroko massive sulfide deposits were classed correctly, 92% of 25 porphyry copper deposits, 78% of 9 Comstock epithermal gold-silver districts, and 83% of six quartzalunite epithermal gold deposits were classed correctly. Across all deposit types, 88% of deposits in the validation dataset were correctly classed. Misclassifications were most common if a deposit was characterized by only a few minerals, e.g., pyrite, chalcopyrite,and sphalerite. The success rate jumped to 98% correctly classed deposits when just two rock types were added. Such a high success rate of the probabilistic neural network suggests that not only should this preliminary test be expanded to include other deposit types, but that other deposit features should be added.

Relationship between metabolic syndrome and its components with bone densitometry in postmenopausal women.

PubMed

Abbasi, Mahnaz; Farzam, Seyed Amir; Mamaghani, Zahra; Yazdi, Zohreh

2017-11-01

Prevention of osteoporosis and bone fracture and the relationship between metabolic syndrome and bone density are controversial issues. The aim of this study was to evaluate the association between metabolic syndrome and its components with bone mineral density in post menopausal women referred for bone mineral density (BMD) test. A total of 143 postmenopausal women with at least one year of menopause experience participated in this cross-sectional study. Demographic and anthropometric characteristics for all participants were collected. Also, biochemical parameters including fasting blood sugar, Cholesterol (HDL and LDL), triglyceride were measured. Association between the components of metabolic syndrome and bone densitometry were analyzed by statistical methods. In this study, 72% of participants did not have metabolic syndrome. Among them, 43.4% and 28.7% had osteoporosis and normal density, respectively. Of remaining participants with metabolic syndrome, 12.6% and 15.4% had osteoporosis and normal density, respectively. Among the metabolic syndrome components, waist circumference, HDL cholesterol, and waist to hip ratio were significantly associated with bone mass (P<0.05). Osteoporotic women had lower waist circumference and waist to hip ratio and higher HDL than women without osteoporosis. On the other hand, women with metabolic syndrome did not have significant differences than women without metabolic syndrome in terms of lumbar and femoral neck density (P>0.05). Results from this study showed that metabolic syndrome and its components did not induce bone mass loss. The discrepancies of the studies in this area call for more large scale studies in population so as to prevent women problems in this area. Copyright © 2016 Diabetes India. Published by Elsevier Ltd. All rights reserved.

Mid-Infrared Spectroscopy Analysis of the Effects of Erbium, Chromium:Yattrium-Scandium-Gallium-Garnet (Er,Cr:YSGG) Laser Irradiation on Bone Mineral and Organic Components.

PubMed

Benetti, Carolina; Ana, Patricia Aparecida; Bachmann, Luciano; Zezell, Denise Maria

2015-12-01

The effects of varying the energy density of a high-intensity erbium, chromium: yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser on the mineral and organic components of bone tissue were evaluated using Fourier transform infrared spectroscopy. Bone samples obtained from the tibias of rabbits were irradiated with five energy densities (3, 6, 8, 12, and 15 J/cm(2)), and the effects on the carbonate to phosphate ratio and in the organic components were compared with those of nonirradiated samples. The increased temperature during the laser irradiation was also measured using infrared thermography to relate the observed spectral changes to the laser thermal effects. The analyses of the infrared spectra suggests that the irradiation with Er,Cr:YSGG promoted changes in bone tissue in both the mineral and organic components that depend on the laser energy density, pointing to the importance of using the proper energy density in clinical procedures.

Assessment of dietary food and nutrient intake and bone density in children with eczema.

PubMed

Leung, T F; Wang, S S; Kwok, F Yy; Leung, L Ws; Chow, C M; Hon, K L

2017-10-01

Dietary restrictions are common among patients with eczema, and such practice may lead to diminished bone mineral density. This study investigated dietary intake and bone mineral density in Hong Kong Chinese children with eczema. This cross-sectional and observational study was conducted in a university-affiliated teaching hospital in Hong Kong. Chinese children aged below 18 years with physician-diagnosed eczema were recruited from our paediatric allergy and dermatology clinics over a 6-month period in 2012. Subjects with stable asthma and/or allergic rhinitis who were free of eczema and food allergy as well as non-allergic children were recruited from attendants at our out-patient clinics as a reference group. Intake of various foods and nutrients was recorded using a food frequency questionnaire that was analysed using Foodworks Professional software. Bone mineral density at the radius and the tibia was measured by quantitative ultrasound bone sonometry, and urinary cross-linked telopeptides were quantified by immunoassay and corrected for creatinine level. Overall, 114 children with eczema and 60 other children as reference group were recruited. Eczema severity of the patients was classified according to the objective SCORing Atopic Dermatitis score. Males had a higher daily energy intake than females (median, 7570 vs 6736 kJ; P=0.035), but intake of any single food item or nutrient did not differ between them. Compared with the reference group, children with eczema had a higher intake of soybeans and miscellaneous dairy products and lower intake of eggs, beef, and shellfish. Children with eczema also consumed less vitamin D, calcium, and iron. The mean (standard deviation) bone mineral density Z-score of children with eczema and those in the reference group were 0.52 (0.90) and 0.55 (1.12) over the radius (P=0.889), and 0.02 (1.03) and -0.01 (1.13) over the tibia (P=0.886), respectively. Urine telopeptide levels were similar between the groups. Calcium intake was associated with bone mineral density Z-score among children with eczema. Dietary restrictions are common among Chinese children with eczema in Hong Kong, who have a lower calcium, vitamin D, and iron intake. Nonetheless, such practice is not associated with changes to bone mineral density or bone resorptive biomarker.

Polymorphism of the vitamin D3 receptor gene and bone mineral density in girls with functional hypothalamic amenorrhea subjected to oestroprogestagen treatment.

PubMed

Sowińska-Przepiera, Elżbieta; Andrysiak-Mamos, Elżbieta; Syrenicz, Justyna; Jarząbek-Bielecka, Grażyna; Friebe, Zbigniew; Syrenicz, Anhelli

2011-01-01

We investigated whether the vitamin D3 receptor gene (VDR) polymorphism can modulate therapeutic response of functional hypothalamic amenorrhea (FHA) patients to the oestroprogestagen (EP) treatment. The study included 84 FHA girls and 50 controls. FHA patients underwent a four-year sequential EP therapy with 17-β oestradiol (2 mg from the 2(nd) to 25(th) day of the menstrual cycle) and didrogesterone (10 mg from the 16(th) to the 25(th) day). Their hormonal parameters were monitored along with bone turnover marker levels and bone mineral density (BMD). Additionally, the VDR gene BsmI polymorphism was determined. Hormonal therapy was reflected by a substantial improvement of BMD. However, the values of BMD observed after four years of treatment in FHA patients were still significantly lower than baseline bone mineral density determined in the control group (1.007 ± 0.100 vs. 1.141 ± 0.093 g/cm(2), respectively; p < 0.001). No significant effects of the VDR genotype were observed on the dynamics of BMD during consecutive years of hormonal treatment and mean bone mineral density determined after completing the therapy (1.006 ± 0.101 vs. 1.013 ± 0.114 vs. 1.006 ± 0.094 g/cm(2) for BB, bb and Bb genotypes, respectively; p = 0.973). This study did not confirm that VDR polymorphism can modulate therapeutic outcome of FHA girls subjected to the hormonal treatment. Nonetheless, this study confirmed the effectiveness of EP therapy in the simultaneous treatment of menstrual disorders and the normalisation of bone mineral density in FHA patients.

Discordance between the degree of osteopenia and the prevalence of spontaneous vertebral fractures in Crohn's disease.

PubMed

Stockbrügger, R W; Schoon, E J; Bollani, S; Mills, P R; Israeli, E; Landgraf, L; Felsenberg, D; Ljunghall, S; Nygard, G; Persson, T; Graffner, H; Bianchi Porro, G; Ferguson, A

2002-08-01

A high prevalence of osteoporosis has been noted in Crohn's disease, but data about fractures are scarce. The relationship between low bone mineral density and the prevalence of vertebral fractures was studied in 271 patients with ileo-caecal Crohn's disease in a large European/Israeli study. One hundred and eighty-one currently steroid-free patients with active Crohn's disease (98 completely steroid-naive) and 90 steroid-dependent patients with inactive or quiescent Crohn's disease were investigated by dual X-ray absorptiometry scan of the lumbar spine, a standardized posterior/anterior and lateral X-ray of the thoracic and lumbar spine, and an assessment of potential risk factors for osteoporosis. Thirty-nine asymptomatic fractures were seen in 25 of 179 steroid-free patients (14.0%; 27 wedge, 12 concavity), and 17 fractures were seen in 13 of 89 steroid-dependent patients (14.6%; 14 wedge, three concavity). The prevalence of fractures in steroid-naive patients was 12.4%. The average bone mineral density, expressed as the T-score, of patients with fractures was not significantly different from that of those without fractures (-0.759 vs. -0.837; P=0.73); 55% of patients with fractures had a normal T-score. The bone mineral density was negatively correlated with lifetime steroids, but not with previous bowel resection or current disease activity. The fracture rate was not correlated with the bone mineral density (P=0.73) or lifetime steroid dose (P=0.83); in women, but not in men, the fracture rate was correlated with age (P=0.009). The lack of correlation between the prevalence of fractures on the one hand and the bone mineral density and lifetime steroid dose on the other necessitates new hypotheses for the pathogenesis of the former.

BsmI vitamin D receptor's polymorphism and bone mineral density in men and premenopausal women on long-term antiepileptic therapy.

PubMed

Lambrinoudaki, I; Kaparos, G; Armeni, E; Alexandrou, A; Damaskos, C; Logothetis, E; Creatsa, M; Antoniou, A; Kouskouni, E; Triantafyllou, N

2011-01-01

utilization of antiepileptic drugs (AEDs) has long been associated with bone deleterious effects. Furthermore, the BsmI restriction fragment polymorphism of the vitamin D receptor (VDR) has been associated with reduced bone mineral density (BMD), mostly in postmenopausal women. This study evaluates the association between bone metabolism of patients with epilepsy and the BsmI VDR's polymorphism in chronic users of AEDs. this study evaluated 73 long-term users of antiepileptic drug monotherapy, in a cross-sectional design. Fasting blood samples were obtained to estimate the circulating serum levels of calcium, magnesium, phosphorus, parathormone, 25 hydroxyvitamin D as well as the VDR's genotype. Bone mineral density at the lumbar spine was measured with Dual Energy X-Ray Absorptiometry. bone mineral density was significantly associated with the genotype of VDR (mean BMD: Bb genotype 1.056 ± 0.126 g/cm(2) ; BB genotype 1.059 ± 0.113 g/cm(2) ; bb genotype 1.179 ± 0.120 g/cm(2) ; P < 0.05). Additionally, the presence of at least one B allele was significantly associated with lower bone mineral density (B allele present: BMD = 1.057 ± 0.12 g/cm(2) , B allele absent: BMD = 1.179 ± 0.119 g/cm(2) ; P < 0.01). Patients with at least one B allele had lower serum levels of 25 hydroxyvitamin D when compared with bb patients (22.61 ng/ml vs. 33.27 ng/ml, P < 0.05), whilst they tended to have higher levels of parathyroid hormone. vitamin D receptor polymorphism is associated with lower bone mass in patients with epilepsy. This effect might be mediated through the vitamin D-parathormone pathway.

Effects on bone mineral density of a monophasic combined oral contraceptive containing nomegestrol acetate/17β-estradiol in comparison to levonorgestrel/ethinylestradiol.

PubMed

Sørdal, Terje; Grob, Paul; Verhoeven, Carole

2012-11-01

To compare the effects of a monophasic combined oral contraceptive containing nomegestrol acetate/17β-estradiol (NOMAC/E2) on bone mineral density with a combined oral contraceptive containing levonorgestrel/ethinylestradiol (LNG/EE). Prospective, randomized, open-label, comparative clinical study. Gynecology center in Norway. One hundred and ten women (20-35 years old) actively seeking contraception. Methods. For 26 consecutive 28-day cycles, women received one of the following two treatments: NOMAC/E2 (2.5 mg/1.5 mg) in a 24/4-day regimen (n= 56); or LNG/EE (150 μg/30 μg) in a 21/7-day regimen (n= 54). Main outcome measures. Bone mineral density of the lumbar spine, femoral neck, hip and trochanter (measured by dual energy X-ray absorptiometry); associated z-scores of the lumbar spine and femoral neck. In NOMAC/E2 users, mean (±SD) z-score change from baseline for lumbar spine and femoral neck were 0.019 ± 0.242 and -0.007 ± 0.228, respectively, vs. 0.121 ± 0.269 and 0.044 ± 0.253 in LNG/EE users, respectively. Differences between treatment groups were not significant (p= 0.19 and p= 0.57, respectively). There were no significant differences between changes in hip and trochanter z-scores between NOMAC/E2 and LNG/EE treatments. After two years, NOMAC/E2 had no clinically relevant effect on bone mineral density. No significant difference in the effect on bone mineral density between NOMAC/E2 and LNG/EE was observed. © 2012 The Authors Acta Obstetricia et Gynecologica Scandinavica© 2012 Nordic Federation of Societies of Obstetrics and Gynecology.

The Relationship between 25 (OH) D Levels (Vitamin D) and Bone Mineral Density (BMD) in a Saudi Population in a Community-Based Setting.

PubMed

Alkhenizan, Abdullah; Mahmoud, Ahmed; Hussain, Aneela; Gabr, Alia; Alsoghayer, Suad; Eldali, Abdelmoneim

2017-01-01

Vitamin D deficiency has been linked to an increased risk of osteoporosis. Vitamin D deficiency has reached high levels in the Saudi population, but there is conflicting evidence both in the Saudi population, and worldwide, regarding the existence of a correlation between these low vitamin D levels and reduced BMD (bone mineral density), or osteoporosis. The objective of this study was primarily to determine whether there was a correlation between vitamin D deficiency and osteoporosis in the Saudi population. We aimed to investigate whether the high levels of vitamin D deficiency and insufficiency would translate to higher prevalence of osteoporosis, and whether there is a correlation between vitamin D levels and bone mineral density. This was a community based cross sectional study conducted in the Family Medicine Clinics at King Faisal Specialist Hospital and Research Centre in Riyadh, Saudi Arabia. Electronic records of 1723 patients were reviewed. Laboratory and radiology results were collected, including vitamin D levels, calcium levels, and bone mineral density scan results. Among the whole population, 61.5% had moderate to severe vitamin D deficiency with levels less than 50nmol/L. 9.1% of the population had osteoporosis, and 38.6% had osteopenia. Among the whole population, there was no significant correlation between spine or total femoral BMD and serum 25(OH) D. Vitamin D deficiency is prevalent in the Saudi population. However, no correlation has been found between vitamin D deficiency and reduced bone mineral density in any age group, in males or females, Saudis or Non-Saudis, in our population in Riyadh, Saudi Arabia.

[EFFECTS IN BODY COMPOSITION AND BONE MINERAL DENSITY OF SIMULATE ALTITUDE PROGRAM IN TRIATHLETES].

PubMed

Ramos-Campo, Domingo Jesús; Rubio Arias, Jacobo Ángel; Jiménez Diaz, José Fernando

2015-09-01

body composition is an important factor to improve athletic performance. Futhermore, bone mineral density informs about the bone stiffness of the skeletal system. the aim of the present research was to analyze modifications on body composition and bone mineral density parameters after a seven week intermittent hypoxia training (IHT) program. eighteen male trained triathletes were divided in two groups: an intermittent hypoxia training group (GIHT: n: 9; 26.0 ± 6.7 years; 173.3 ± 5.9 cm; 66.4 ± 5.9 kg; VO2 max: 59.5 ± 5.0 ml/kg/min) that conducted a normoxic training plus an IHT and a control group (GC: n: 9; 29.3 ± 6.8 years; 174.9 ± 4.6 cm; 59.7 ± 6.8 kg; VO2 max: 58.9 ± 4.5 ml/kg/min) that performed only a normoxic training. Training process was standardized across the two groups. The IHT program consisted on two 60 minutes sessions per week at intensities over the anaerobic threshold and atmospheric conditions between 14.5 and 15% FiO2. Before and after the seven week training, body composition and bone mineral density were analyzed. After this training program, the GIHT showed lower values in free fat mass in upper limbs and fat mass in lower limbs (p < 0.05) than before the program. In terms of bone mineral density variables, between the two groups no changes were found. the addition of an IHT program to normoxic training caused an improvement in body composition parameters compared to similar training under normoxic conditions. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

Effect of cisplatin on bone transport osteogenesis in dogs.

PubMed

Ehrhart, Nicole; Eurell, Jo Ann C; Tommasini, Matteo; Constable, Peter D; Johnson, Ann L; Feretti, Antonio

2002-05-01

To document effects of cisplatin on regenerate bone formation during the distraction and consolidation phases of bone transport osteogenesis. 10 skeletally mature hounds. Bone transport osteogenesis was performed to reconstruct a 3-cm defect in the radius of each dog. Five dogs were randomly selected to receive cisplatin (70 mg/m2, IV, q 21 d for 4 cycles), and 5 were administered saline (0.9% NaCl) solution. Bone mineral density was measured by use of dual-energy x-ray absorptiometry (DEXA) on days 24, 55, and 90 after surgery. Dogs were euthanatized 90 days after surgery. Histomorphometry was performed on nondecalcified sections of regenerate bone. Bone mineral density and histomorphometric indices of newly formed bone were compared between groups. Densitometric differences in regenerate bone mineral density were not detected between groups at any time period. Cisplatin-treated dogs had decreased mineralized bone volume, decreased percentage of woven bone volume, decreased percentage of osteoblast-covered bone, increased porosity, and increased percentage of osteoblast-covered surfaces, compared with values for control dogs. Lamellar bone volume and osteoid volume did not differ significantly between groups. Regenerate bone will form and remodel during administration of cisplatin. Results of histomorphometric analysis suggest that bone formation and resorption may be uncoupled in cisplatin-treated regenerate bone as a result of increased osteoclast activity or delayed secondary bone formation during remodeling. These histomorphometric differences were modest in magnitude and did not result in clinically observable complications or decreased bone mineral density as measured by use of DEXA.

[Factors associated with osteopenia and osteoporosis in women undergoing bone mineral density test].

PubMed

Veiga Silva, Ana Carolina; da Rosa, Maria Inês; Fernandes, Bruna; Lumertz, Suéli; Diniz, Rafaela Maria; dos Reis Damiani, Maria Eduarda Fernandes

2015-01-01

The aim of this study was to determine the prevalence of osteopenia and osteoporosis in a female population, that had bone mineral density (BMD) measured by dual-energy X-ray absorptiometry (DXA) in a specialized clinic in the south of Brazil. We conducted a cross-sectional study including 1,871 women that performed scans between January and December 2012. We conducted a logistic regression analysis with all independent variables and outcomes (osteopenia, osteoporosis and fracture risk). According to DXA results, 36.5% of women had normal BMD, 49.8% were diagnosed with osteopenia and 13.7% with osteoporosis. Menopause and age over 50 years old were risk factors for osteopenia and osteoporosis while prior hysterectomy and BMI greater than 25 were protective factors. For the outcome of fracture at any site the risk factors were age over 50 years old, osteopenia and osteoporosis (OR = 2.09, 95% CI:1,28-3, 40) and (OR = 2.49, 95% CI:1,65-3, 74), respectively. Copyright © 2014 Elsevier Editora Ltda. All rights reserved.

[Nutritional status, body composition and bone mineral density in gastric bypass females: impact of socioeconomic level].

PubMed

de la Maza, María Pía; Leiva, Laura; Barrera, Gladys; Boggiano, Carolina; Herrera, Tomás; Pérez, Yanet; Gattás, Vivien; Bunout, Daniel; Hirsch, Sandra

2008-11-01

Roux-en-Y gastric bypass (RYGBP) has had a posilive impact on co-mobidities associated with obesity. However, in the long-term it can induce micronutrient deficiencies. To petform a complete nutritional assessment in a group of women previously operated of RYGBP from different socioeconomic levels (SEL). Thirtyy three women (19 high SEL and 14 low SEL), were assessed by dietary recalls, anthropometric measurements, muscle strength, bone mineral density, routine clinical laboratory, semm leeds of vitamin B12, 25OH-vitamin D, folate, calcium, ferritine ceruloplasmin and indicators of bone tutnoter (paratbohormone, osteocalcin and urinary pyridinolines). Their values were compared to those of 30 control women (18 high SEL and 12 low SEL). Low SEL operated women consumed fewer vitamin and mineral supplements compared with their high SEL pairs. No cases of vitamin B12, folic acid or copper deficiencies were detected. Frequency of iron deficiency was similar in patients and controls. Vitamin D insufficiency was higher among patients than in controls (p = 0.047), regardless SEL. Patients had also a higher frequency of high senum P771 and osteocakin and urinary pyridinoline levels. However, no differences in bone mineral density were obseived between operated women and controls. Vitamin and mineral deficiencies were lower than expected among operated women. However problems associated with vitamin D deficiency were highly prevalent among patients operated of RYGBP, irrespective SEL. These alterations were only detectable through specific markers at this stage, because they did not translate into lower bone mineral density (BMD) of sutgical patients, probably due to the higher pre-operative BMD of these moibid obese patients

Intestinal absorption and renal reabsorption of calcium throughout postnatal development

PubMed Central

Beggs, Megan R

2017-01-01

Calcium is vital for many physiological functions including bone mineralization. Postnatal deposition of calcium into bone is greatest in infancy and continues through childhood and adolescence until peek mineral density is reached in early adulthood. Thereafter, bone mineral density remains static until it eventually declines in later life. A positive calcium balance, i.e. more calcium absorbed than excreted, is crucial to bone deposition during growth and thus to peek bone mineral density. Dietary calcium is absorbed from the intestine into the blood. It is then filtered by the renal glomerulus and either reabsorbed by the tubule or excreted in the urine. Calcium can be (re)absorbed across intestinal and renal epithelia via both transcellular and paracellular pathways. Current evidence suggests that significant intestinal and renal calcium transport changes occur throughout development. However, the molecular details of these alterations are incompletely delineated. Here we first briefly review the current model of calcium transport in the intestine and renal tubule in the adult. Then, we describe what is known with regard to calcium handling through postnatal development, and how alterations may aid in mediating a positive calcium balance. The role of transcellular and paracellular calcium transport pathways and the contribution of specific intestinal and tubular segments vary with age. However, the current literature highlights knowledge gaps in how specifically intestinal and renal calcium (re)absorption occurs early in postnatal development. Future research should clarify the specific changes in calcium transport throughout early postnatal development including mediators of these alterations enabling appropriate bone mineralization. Impact statement This mini review outlines the current state of knowledge pertaining to the molecules and mechanisms maintaining a positive calcium balance throughout postnatal development. This process is essential to achieving optimal bone mineral density in early adulthood, thereby lowering the lifetime risk of osteoporosis. PMID:28346014

Correlation between the extent of catalytic activity and charge density of montmorillonites.

PubMed

Ertem, Gözen; Steudel, Annett; Emmerich, Katja; Lagaly, Gerhard; Schuhmann, Rainer

2010-09-01

The clay mineral montmorillonite is a member of the phyllosilicate group of minerals, which has been detected on martian soil. Montmorillonite catalyzes the condensation of activated monomers to form RNA-like oligomers. Extent of catalysis, that is, the yield of oligomers, and the length of the longest oligomer formed in these reactions widely varies with the source of montmorillonite (i.e., the locality where the mineral is mined). This study was undertaken to establish whether there exists a correlation between the extent of catalytic property and the charge density of montmorillonites. Charge density was determined by saturating the montmorillonites with alkyl ammonium cations that contained increasing lengths of alkyl chains, [CH₃-(CH₂)(n)-NH₃](+), where n = 3-16 and 18, and then measuring d(₀₀₁), interlayer spacing of the resulting montmorillonite-alkyl ammonium-montmorillonite complex by X-ray diffractometry (XRD). Results demonstrate that catalytic activity of montmorillonites with lower charge density is superior to that of higher charge density montmorillonite. They produce longer oligomers that contain 9 to 10 monomer units, while montmorillonite with high charge density catalyzes the formation of oligomers that contain only 4 monomer units. The charge density of montmorillonites can also be calculated from the chemical composition if elemental analysis data of the pure mineral are available. In the next mission to Mars, CheMin (Chemistry and Mineralogy), a combined X-ray diffraction/X-ray fluorescence instrument, will provide information on the mineralogical and elemental analysis of the samples. Possible significance of these results for planning the future missions to Mars for the search of organic compounds and extinct or extant life is discussed.

Veganism and osteoporosis: a review of the current literature.

PubMed

Smith, Annabelle M

2006-10-01

The purpose of this review is to examine the current literature regarding calcium and Vitamin D deficiencies in vegan diets and the possible relationship to low bone mineral density and incidence for fracture. Prominent databases were searched for original research publications providing data capable of answering these questions: (i) Do vegans have lower-than-recommended levels of calcium/Vitamin D? (ii) Do vegans have lower bone mineral density than their non-vegan counterparts? (iii) Are vegans at a greater risk for fractures than non-vegans? The findings gathered consistently support the hypothesis that vegans do have lower bone mineral density than their non-vegan counterparts. However, the evidence regarding calcium, Vitamin D and fracture incidence is inconclusive. More research is needed to definitively answer these questions and to address the effects of such deficiencies on the medical and socioeconomic aspects of life.

High-intensity exercise of short duration alters bovine bone density and shape.

PubMed

Hiney, K M; Nielsen, B D; Rosenstein, D; Orth, M W; Marks, B P

2004-06-01

The ability of short-duration high-intensity exercise to stimulate bone formation in confinement was investigated using immature Holstein bull calves as a model. Eighteen bull calves, 8 wk of age, were assigned to one of three treatment groups: 1) group-housed (GR, which served as a control), 2) confined with no exercise (CF), or 3) confined with exercise (EX). The exercise protocol consisted of running 50 m on a concrete surface once daily, 5 d/wk. Confined calves remained stalled for the 42-d duration of the trial. Blood samples were taken to analyze concentrations of osteocalcin and deoxypyridinoline, markers of bone formation and resorption. At the completion of the trial, calves were humanely killed, and both forelegs were collected. The fused third and fourth metacarpal bone was scanned using computed tomography for determination of cross-sectional geometry and bone mineral density. Three-point bending tests to failure were performed on metacarpal bones. The exercise protocol resulted in the formation of a rounder bone in EX as well as in increased dorsal cortex thickness compared with those in the GR and CF. The exercised calves had a significantly smaller medullary cavity than CF and GR (P < 0.01) and a larger percentage of cortical bone area than CF (P < 0.01). Dorsal, palmar, and total bone mineral density was greater in EX than in CF (P < 0.05), and palmar and total bone mineral densities were greater (P < 0.05) in EX than in GR. There was a trend for the bones of EX to have a higher fracture force than CF (P < 0.10). Osteocalcin concentrations normalized from d 0 were higher in EX than CF (P < 0.05). Therefore, the exercise protocol altered bone shape and seemed to increase bone formation comparison with the stalled and group-housed calves.

Bone Density, Microarchitecture, and Tissue Quality Long-term After Kidney Transplant.

PubMed

Pérez-Sáez, María José; Herrera, Sabina; Prieto-Alhambra, Daniel; Nogués, Xavier; Vera, María; Redondo-Pachón, Dolores; Mir, Marisa; Güerri, Roberto; Crespo, Marta; Díez-Pérez, Adolfo; Pascual, Julio

2017-06-01

Bone mineral density (BMD) measured by dual-energy x-ray absorptiometry is used to assess bone health in kidney transplant recipients (KTR). Trabecular bone score and in vivo microindentation are novel techniques that directly measure trabecular microarchitecture and mechanical properties of bone at a tissue level and independently predict fracture risk. We tested the bone status of long-term KTR using all 3 techniques. Cross-sectional study including 40 KTR with more than 10 years of follow-up and 94 healthy nontransplanted subjects as controls. Bone mineral density was measured at lumbar spine and the hip. Trabecular bone score was measured by specific software on the dual-energy x-ray absorptiometry scans of lumbar spine in 39 KTR and 77 controls. Microindentation was performed at the anterior tibial face with a reference-point indenter device. Bone measurements were standardized as percentage of a reference value, expressed as bone material strength index (BMSi) units. Multivariable (age, sex, and body mass index-adjusted) linear regression models were fitted to study the association between KTR and BMD/BMSi/trabecular bone score. Bone mineral density was lower at lumbar spine (0.925 ± 0.15 vs 0.982 ± 0.14; P = 0.025), total hip (0.792 ± 0.14 vs 0.902 ± 0.13; P < 0.001), and femoral neck (0.667 ± 0.13 vs 0.775 ± 0.12; P < 0.001) in KTR than in controls. BMSi was also lower in KTR (79.1 ± 7.7 vs 82.9 ± 7.8; P = 0.012) although this difference disappeared after adjusted model (P = 0.145). Trabecular bone score was borderline lower (1.21 ± 0.14 vs 1.3 ± 0.15; adjusted P = 0.072) in KTR. Despite persistent decrease in BMD, trabecular microarchitecture and tissue quality remain normal in long-term KTR, suggesting important recovery of bone health.

A role for charcoal's physical properties in its carbon cycle fluxes

NASA Astrophysics Data System (ADS)

Masiello, C. A.; Dugan, B.; Gao, X.; Pyle, L.; Sorrenti, G.; LaMere, L.; Liu, Z.; Zygourakis, K.

2016-12-01

The production of charcoal by fire generates a pool of soil carbon that is more biologically resistant to decomposition than many other forms of soil organic matter, and in some cases charcoal accumulates on the landscape. In other situations, however, charcoal does not accumulate, and is rapidly lost to rivers and eventually delivered to the ocean, where it can form a significant component of sedimentary organic carbon. The physical properties of charcoal form one basic dimension controlling whether charcoal is stored on the landscape or whether it moves to rivers and eventually marine sediments. It is simple to understand how charcoal density and porosity can play a crucial role in its mobility on the landscape: when charcoal pores are filled with air, the bulk density of charcoal can be as low as 0.25 g/cm3, and it will float and thus is easily transported with water runoff. As pores fill with water or soil minerals, the bulk density increases and can exceed 1 g/cm3, which will promote sinking and decrease mobility. For example, a charcoal with an internal porosity of 30% must have 90% of the pores saturated with water to achieve a bulk density greater than 1 g/cm3. Alternately for that same charcoal 20% of charcoal pores would need to infill with soil minerals (mineral density = 3.8 g/cm3) to achieve a density greater than 1 g/cm3. This mineral-infilling process has not been widely observed. Instead, early laboratory and field data suggest that the soil minerals partially block pores in charcoal and this process slows the rate of water transport into charcoal pores. If widespread, this process of partial pore throat occlusion may limit the rate of biochar saturation and thus help control the long-term landscape fate of charcoal.

Relationship between serum albumin and bone mineral density in postmenopausal women and in patients with hypoalbuminemia.

PubMed

D'Erasmo, E; Pisani, D; Ragno, A; Raejntroph, N; Letizia, C; Acca, M

1999-06-01

Some discrepancies exist about the relationship between serum albumin level and the pathogenesis of osteoporosis; moreover, most of the studies available have especially concerned patients with osteoporosis, often associated with fractures. Our study, therefore, aims to investigate the presence of a relationship between serum albumin level and bone mineral density in a group of healthy women (n=650; mean age 59.0 +/- 7.4 years) who voluntarily underwent screening for osteoporosis only because they were menopausal (11.2 +/- 7.4 years since menopause) and, for comparison, in a group of outpatients (n = 44; mean age 57.6 +/- 7.0 years; 9.1 +/- 6.7 years since menopause) with hypoalbuminemia associated with diseases. The results show a lack of any relationship in healthy women between serum albumin value and bone mineral density; the lack of correlation was also shown when the postmenopausal women were down into normal, osteopenic and osteoporotic (WHO criteria) or in hypo, normal and hyperalbuminemic. The only significant parameters associated with lower bone mineral density, in fact, were age and years since menopause (p<0.0001 and p<0.0001 respectively at lumbar spine and p<0.02 and p<0.001 at femoral neck level). In the group of patients with hypoalbuminemia associated with diseases, on the other hand, a relationship between reduced bone mineral density and hypoalbuminemia was found (p<0.01 and p<0.05 respectively at lumbar spine and femoral neck). In conclusion, in healthy postmenopausal women the serum albumin level does not play a significant role in the pathogenesis of bone density reduction, which is mainly due to the number of years since menopause and advancing age. The hypoalbuminemia may be related to the reduction of bone mass only in the subjects affected by diseases associated with a significant albumin reduction.

Impact of calcium and vitamin D insufficiencies on serum parathyroid hormone and bone mineral density: analysis of the 4th & 5th Korean National Health and Nutrition Examination Survey

USDA-ARS?s Scientific Manuscript database

The relative contributions of calcium and vitamin D to calcium metabolism and bone mineral density (BMD) have been examined previously, but not in a population with very low calcium intake. To determine the relative importance of dietary calcium intake and serum 25-hydroxyvitamin D [25(OH)D] concent...

Bone Mineral Density Changes after Physical Training and Calcium Intake in Students with Attention Deficit and Hyper Activity Disorders

ERIC Educational Resources Information Center

Arab ameri, Elahe; Dehkhoda, Mohammad Reza; Hemayattalab, Rasool

2012-01-01

In this study we investigate the effects of weight bearing exercise and calcium intake on bone mineral density (BMD) of students with attention deficit and hyper activity (ADHD) disorder. For this reason 54 male students with ADHD (age 8-12 years old) were assigned to four groups with no differences in age, BMD, calcium intake, and physical…

The recent prevalence of Osteoporosis and low bone mass in the United States based on bone mineral density at the Femoral Neck or Lumbar Spine

USDA-ARS?s Scientific Manuscript database

The goal of our study was to estimate the prevalence of osteoporosis and low bone mass based on bone mineral density (BMD) at the femoral neck and the lumbar spine in adults 50 years and older in the United States (US). We applied prevalence estimates of osteoporosis or low bone mass at the femoral ...

Bone mass and vitamin D levels in Parkinson's disease: is there any difference between genders?

PubMed

Ozturk, Erhan Arif; Gundogdu, Ibrahim; Tonuk, Burak; Kocer, Bilge Gonenli; Tombak, Yasemin; Comoglu, Selcuk; Cakci, Aytul

2016-08-01

[Purpose] The aim of this study was to determine the bone mineral density, vitamin D level, and frequencies of osteopenia and osteoporosis in patients with Parkinson's disease and to compare male and female patients with the controls separately. [Subjects and Methods] One hundred fifteen Parkinson's disease patients (47 males, 68 females; age range: 55-85 years) and 117 age- and gender-matched controls (47 males, 70 females) were enrolled in the study. Bone mineral density measured by dual-energy X-ray absorptiometry and serum D vitamin levels of each participant were recorded. [Results] The mean lumbar spine, femur neck, and total femur bone mineral density levels, T-scores, and vitamin D levels were found to be significantly lower in Parkinson's disease patients in both genders. Furthermore, osteoporosis rates were found be significantly higher only in female Parkinson's disease patients compared with female controls. [Conclusion] Data from the present study revealed that while osteoporosis was significantly higher only in female Parkinson's disease patients, all Parkinson's disease patients had lower bone mineral density scores and vitamin D levels compared with the controls regardless of gender, suggesting that clinicians should pay attention to the osteoporosis risk in Parkinson's disease and that adequate preventive measures should be taken in order to limit the future risk due to osteoporotic fractures.

[Number of teeth and hormonal profile of postmenopausal women with osteoporosis, osteopenia and normal bone mineral density--a preliminary study].

PubMed

Stagraczyński, Maciej; Kulczyk, Tomasz; Leszczyński, Piotr; Męczekalski, Błażej

2015-10-01

Profound hypoestrogenism causes increased risk of osteoporosis and bone fracture in menopause. This period of women life is also characterized by decrease number of teeth and deterioration of oral cavity health. The aim of the study was to assess the number of teeth, hormonal profile (Follicle-stimualting hormone (FSH), estradiol (E2), testosterone (T) and dehydroepiandrosterone sulphate (DHEA-S) and the bone mineral density (BMD) of the lumbar part of the spine in postmenopausal women with osteoporosis, osteopenia and normal BMD. The next step of the study was to determine whether there was a correlation between vertebral mineral bone density, the hormonal profile and the number of teeth. A total number of 47 women was involved in the study. Based on the results of densitometry tests (DEXA) of vertebral column the subjects were divided into 3 groups: 10 with osteoporosis, 20 with osteopenia and 17 with normal BMD. All the subjects had undergone a hormonal assessment which included blood serum estimation for FSH, E2, DHEA-S and T levels. Also the total number of teeth present was recorded. Serum estradiol and testosterone levels in postmenopausal women were found to be positively correlated with the number of teeth present. A negative correlation was found between age and the number of maxillary teeth in postmenopausal women with osteopenia. There was no influence of serum FSH, estradiol, testosterone and DHEA-S levels on vertebral BMD loss in postmenopausal women. There was no correlation between teeth number and BMD of vertebral column. Serum levels of estradiol and testosterone in postmenopausal women positively correlate with teeth numbers. Age is the main risk factor for teeth loss in postmenopausal women. © 2015 MEDPRESS.

Circulating gonadotropins and ovarian adiponectin system are modulated by acupuncture independently of sex steroid or β-adrenergic action in a female hyperandrogenic rat model of polycystic ovary syndrome.

PubMed

Maliqueo, Manuel; Benrick, Anna; Alvi, Asif; Johansson, Julia; Sun, Miao; Labrie, Fernand; Ohlsson, Claes; Stener-Victorin, Elisabet

2015-09-05

Acupuncture with combined manual and low-frequency electrical stimulation, or electroacupuncture (EA), reduces endocrine and reproductive dysfunction in women with polycystic ovary syndrome (PCOS), likely by modulating sympathetic nerve activity or sex steroid synthesis. To test this hypothesis, we induced PCOS in rats by prepubertal implantation of continuous-release letrozole pellets (200 µg/day) or vehicle. Six weeks later, rats were treated for 5-6 weeks with low-frequency EA 5 days/week, subcutaneous injection of 17β-estradiol (2.0 µg) every fourth day, or a β-adrenergic blocker (propranolol hydrochloride, 0.1 mg/kg) 5 days/week. Letrozole controls were handled without needle insertion or injected with sesame oil every fourth day. Estrous cyclicity, ovarian morphology, sex steroids, gonadotropins, insulin-like growth factor I, bone mineral density, and gene and protein expression in ovarian tissue were measured. Low-frequency EA induced estrous-cycle changes, decreased high levels of circulating luteinizing hormone (LH) and the LH/follicle-stimulating hormone (FSH) ratio, decreased high ovarian gene expression of adiponectin receptor 2, and increased expression of adiponectin receptor 2 protein and phosphorylation of ERK1/2. EA also increased cortical bone mineral density. Propranolol decreased ovarian expression of Foxo3, Srd5a1, and Hif1a. Estradiol decreased circulating LH, induced estrous cycle changes, and decreased ovarian expression of Adipor1, Foxo3, and Pik3r1. Further, total bone mineral density was higher in the letrozole-estradiol group. Thus, EA modulates the circulating gonadotropin levels independently of sex steroids or β-adrenergic action and affects the expression of ovarian adiponectin system. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Relationships of bone characteristics in MYO9B deficient femurs.

PubMed

Kim, Do-Gyoon; Jeong, Yong-Hoon; McMichael, Brooke K; Bähler, Martin; Bodnyk, Kyle; Sedlar, Ryan; Lee, Beth S

2018-08-01

The objective of this study was to examine relationships among a variety of bone characteristics, including volumetric, mineral density, geometric, dynamic mechanical analysis, and static fracture mechanical properties. As MYO9B is an unconventional myosin in bone cells responsible for normal skeletal growth, bone characteristics of wild-type (WT), heterozygous (HET), and MYO9B knockout (KO) mice groups were compared as an animal model to express different bone quantity and quality. Forty-five sex-matched 12-week-old mice were used in this study. After euthanization, femurs were isolated and scanned using microcomputed tomography (micro-CT) to assess bone volumetric, tissue mineral density (TMD), and geometric parameters. Then, a non-destructive dynamic mechanical analysis (DMA) was performed by applying oscillatory bending displacement on the femur. Finally, the same femur was subject to static fracture testing. KO group had significantly lower length, bone mineral density (BMD), bone mass and volume, dynamic and static stiffness, and strength than WT and HET groups (p < 0.019). On the other hand, TMD parameters of KO group were comparable with those of WT group. HET group showed volumetric, geometric, and mechanical properties similar to WT group, but had lower TMD (p < 0.014). Non-destructive micro-CT and DMA parameters had significant positive correlations with strength (p < 0.015) without combined effect of groups and sex on the correlations (p > 0.077). This comprehensive characterization provides a better understanding of interactive behavior between the tissue- and organ-level of the same femur. The current findings elucidate that MYO9B is responsible for controlling bone volume to determine the growth rate and fracture risk of bone. Copyright © 2018 Elsevier Ltd. All rights reserved.

[The combined action of drinking mineral water and low-intensity electromagnetic radiation under the immobilization stress conditions (an experimental study)].

PubMed

Korolev, Yu N; Bobrovnitsky, I P; Geniatulina, M S; Mikhailik, L V; Nikulina, L A; Bobkova, A S; Yakovlev, M Yu

2015-01-01

The present study carried out on white male rats in experiments with the use of biochemical, radioimmunological, and electron- microscopic methods. It was shown that the combined treatment with potable mineral water (MV) and low-intensity electromagnetic radiation (LIEMR) of ultrahigh frequency (power density less than 1 pW/cm2, the frequency about 1000 MHz) facilitated the activation of metabolic and intracellular regenerative processes in the liver and testes. One of the advantages of the combined application of MV and LIEMR over the single-factor treatment manifested itself as the weakening of stress reactions, the increase in the frequency of the plastic processes, and the more harmonious development of different forms of intracellular regeneration. The results of the study provide a deeper insight ino the mechanisms underlying the combined actions of drinking mineral water and low-intensity electromagnetic radiation; also, they justify the application of these factors for the protection of the reproductive system and the entire body from stress-induced disorders.

Bisphosphonate therapy for osteogenesis imperfecta.

PubMed

Dwan, Kerry; Phillipi, Carrie A; Steiner, Robert D; Basel, Donald

2016-10-19

Osteogenesis imperfecta is caused by a genetic defect resulting in an abnormal type I collagen bone matrix which typically results in multiple fractures with little or no trauma. Bisphosphonates are used in an attempt to increase bone mineral density and reduce these fractures in people with osteogenesis imperfecta. This is an update of a previously published Cochrane Review. To assess the effectiveness and safety of bisphosphonates in increasing bone mineral density, reducing fractures and improving clinical function in people with osteogenesis imperfecta. We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Inborn Errors of Metabolism Trials Register which comprises references identified from comprehensive electronic database searches, handsearches of journals and conference proceedings. We additionally searched PubMed and major conference proceedings.Date of the most recent search of the Cochrane Cystic Fibrosis and Genetic Disorders Group's Inborn Errors of Metabolism Register: 28 April 2016. Randomised and quasi-randomised controlled trials comparing bisphosphonates to placebo, no treatment, or comparator interventions in all types of osteogenesis imperfecta. Two authors independently extracted data and assessed the risk of bias of the included trials. Fourteen trials (819 participants) were included. Overall, the trials were mainly at a low risk of bias, although selective reporting was an issue in several of the trials. Data for oral bisphosphonates versus placebo could not be aggregated; a statistically significant difference favouring oral bisphosphonates in fracture risk reduction and number of fractures was noted in two trials. No differences were reported in the remaining three trials which commented on fracture incidence. Five trials reported data for spine bone mineral density; all found statistically significant increased lumbar spine density z scores for at least one time point studied. For intravenous bisphosphonates versus placebo, aggregated data from two trials showed no statistically significant difference for the number of participants with at least one fracture, risk ratio 0.56 (95% confidence interval 0.30 to 1.06). In the remaining trial no statistically significant difference was noted in fracture incidence. For spine bone mineral density, no statistically significant difference was noted in the aggregated data from two trials, mean difference 9.96 (95% confidence interval -2.51 to 22.43). In the remaining trial a statistically significant difference in mean per cent change in spine bone mineral density z score favoured intravenous bisphosphonates at six and 12 months. Data describing growth, bone pain, and functional outcomes after oral or intravenous bisphosphonate therapy, or both, as compared to placebo were incomplete among all studies, but do not show consistent improvements in these outcomes. Two studies compared different doses of bisphosphonates. No differences were found between doses when bone mineral density, fractures, and height or length z score were assessed. One trial compared oral versus intravenous bisphosphonates and found no differences in primary outcomes. Two studies compared the intravenous bisphosphonates zoledronic acid and pamidronate. There were no significant differences in primary outcome. However, the studies were at odds as to the relative benefit of zoledronic acid over pamidronate for lumbosacral bone mineral density at 12 months. Bisphophonates are commonly prescribed to individuals with osteogenesis imperfecta. Current evidence, albeit limited, demonstrates oral or intravenous bisphosphonates increase bone mineral density in children and adults with this condition. These were not shown to be different in their ability to increase bone mineral density. It is unclear whether oral or intravenous bisphosphonate treatment consistently decreases fractures, though multiple studies report this independently and no studies report an increased fracture rate with treatment. The studies included here do not show bisphosphonates conclusively improve clinical status (reduce pain; improve growth and functional mobility) in people with osteogenesis imperfecta. Given their current widespread and expected continued use, the optimal method, duration of therapy and long-term safety of bisphosphonate therapy require further investigation. In addition, attention should be given to long-term fracture reduction and improvement in quality of life indicators.

Bisphosphonate therapy for osteogenesis imperfecta.

PubMed

Dwan, Kerry; Phillipi, Carrie A; Steiner, Robert D; Basel, Donald

2014-07-23

Osteogenesis imperfecta is caused by a genetic defect resulting in an abnormal type I collagen bone matrix which typically results in multiple fractures with little or no trauma. Bisphosphonates are used in an attempt to increase bone mineral density and reduce these fractures in people with osteogenesis imperfecta. To assess the effectiveness and safety of bisphosphonates in increasing bone mineral density, reducing fractures and improving clinical function in people with osteogenesis imperfecta. We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Inborn Errors of Metabolism Trials Register which comprises references identified from comprehensive electronic database searches, handsearches of journals and conference proceedings. We additionally searched PubMed and major conference proceedings.Date of the most recent search: 07 April 2014. Randomised and quasi-randomised controlled trials comparing bisphosphonates to placebo, no treatment, or comparator interventions in all types of osteogenesis imperfecta. Two authors independently extracted data and assessed the risk of bias of the included trials. Fourteen trials (819 participants) were included. Overall, the trials were mainly at a low risk of bias, although selective reporting was an issue in several of the trials. Data for oral bisphosphonates versus placebo could not be aggregated; a statistically significant difference favouring oral bisphosphonates in fracture risk reduction and number of fractures was noted in two trials. No differences were reported in the remaining three trials which commented on fracture incidence. Five trials reported data for spine bone mineral density; all found statistically significant increased lumbar spine density z scores for at least one time point studied. For intravenous bisphosphonates versus placebo, aggregated data from two trials showed no statistically significant difference for the number of participants with at least one fracture, risk ratio 0.56 (95% confidence interval 0.30 to 1.06). In the remaining trial no statistically significant difference was noted in fracture incidence. For spine bone mineral density, no statistically significant difference was noted in the aggregated data from two trials, mean difference 9.96 (95% confidence interval -2.51 to 22.43). In the remaining trial a statistically significant difference in mean per cent change in spine bone mineral density z score favoured intravenous bisphosphonates at six and 12 months. Data describing growth, bone pain, and functional outcomes after oral or intravenous bisphosphonate therapy, or both, as compared to placebo were incomplete among all studies, but do not show consistent improvements in these outcomes. Two studies compared different doses of bisphosphonates. No differences were found between doses when bone mineral density, fractures, and height or length z score were assessed. One study compared oral versus intravenous bisphosphonates and found no differences in primary outcomes. Two studies compared the intravenous bisphosphonates zoledronic acid and pamidronate. There were no significant differences in primary outcome. However, the studies were at odds as to the relative benefit of zoledronic acid over pamidronate for lumbosacral bone mineral density at 12 months. Bisphophonates are commonly prescribed to individuals with osteogenesis imperfecta. Current evidence, albeit limited, demonstrates oral or intravenous bisphosphonates increase bone mineral density in children and adults with this condition. These were not shown to be different in their ability to increase bone mineral density. It is unclear whether oral or intravenous bisphosphonate treatment consistently decreases fractures, though multiple studies report this independently and no studies report an increased fracture rate with treatment. The studies included here do not show bisphosphonates conclusively improve clinical status (reduce pain; improve growth and functional mobility) in people with osteogenesis imperfecta. Given their current widespread and expected continued use, the optimal method, duration of therapy and long-term safety of bisphosphonate therapy require further investigation. In addition, attention should be given to long-term fracture reduction and improvement in quality of life indicators.

Thermography Control of Heat Insulation and Tightness of Buildings,

DTIC Science & Technology

1980-11-01

drawing, top to bottom: 100 + 50 mm mineral wool panels, bulk density 50 kg/m3 Vapor barrier of plastic foil 3/4" tongue and groove 13 mm gypsum panel...Horizontal steel bolts Horisontella Air leakage, in A Ireqlar Corrugated sheet metal 90 mm mineral wool (with sheathing paper) Ko"mir) emd 30 mm mineral ...bolt; Outward leakage of warm air from the room; Steel siding; 90 mm mineral wool (with wind protection); 30 mm mineral wool (with vapor barrier

Effects of Amlodipine on Bone Metabolism in Orchidectomised Spontaneously Hypertensive Rats.

PubMed

Zivna, Helena; Gradošová, Iveta; Zivny, Pavel; Cermakova, Eva; Palicka, Vladimir

2018-06-13

Spontaneously hypertensive rats (SHR) represent a model of essential hypertension. We studied the effect of amlodipine (AML) on bone markers, bone mineral density (BMD), and biomechanical properties of osteopenic bone induced by orchidectomy in male SHR. Rats were allocated to 3 groups and were sacrificed after 12 weeks: sham-operated control; orchidectomised control; and orchidectomised receiving a diet supplemented with AML. Indicators of bone turnover were assessed in bone homogenate, BMD was measured by dual energy X-ray absorptiometry, and the femurs were subjected to biomechanical testing. Long-term AML administration does not have a negative impact on bone metabolism and density in male SHR. © 2018 S. Karger AG, Basel.

Developing a bone mineral density test result letter to send to patients: a mixed-methods study

PubMed Central

Edmonds, Stephanie W; Solimeo, Samantha L; Lu, Xin; Roblin, Douglas W; Saag, Kenneth G; Cram, Peter

2014-01-01

Purpose To use a mixed-methods approach to develop a letter that can be used to notify patients of their bone mineral density (BMD) results by mail that may activate patients in their bone-related health care. Patients and methods A multidisciplinary team developed three versions of a letter for reporting BMD results to patients. Trained interviewers presented these letters in a random order to a convenience sample of adults, aged 50 years and older, at two different health care systems. We conducted structured interviews to examine the respondents’ preferences and comprehension among the various letters. Results A total of 142 participants completed the interview. A majority of the participants were female (64.1%) and white (76.1%). A plurality of the participants identified a specific version of the three letters as both their preferred version (45.2%; P<0.001) and as the easiest to understand (44.6%; P<0.01). A majority of participants preferred that the letters include specific next steps for improving their bone health. Conclusion Using a mixed-methods approach, we were able to develop and optimize a printed letter for communicating a complex test result (BMD) to patients. Our results may offer guidance to clinicians, administrators, and researchers who are looking for guidance on how to communicate complex health information to patients in writing. PMID:24940049

Non-autoclaved aerated concrete with mineral additives

NASA Astrophysics Data System (ADS)

Il'ina, L. V.; Rakov, M. A.

2016-01-01

We investigated the effect of joint grinding of Portland cement clinker, silica and carbonate components and mineral additives to specific surface of 280 - 300 m2/kg on the properties (strength, average density and thermal conductivity) of non-autoclaved aerated concrete, and the porosity of the hardened cement paste produced from Portland cement clinker with mineral additives. The joint grinding of the Portland cement clinker with silica and carbonate components and mineral additives reduces the energy consumption of non-autoclaved aerated concrete production. The efficiency of mineral additives (diopside, wollastonite) is due to the closeness the composition, the type of chemical bonds, physical and chemical characteristics (specific enthalpy of formation, specific entropy) to anhydrous clinker minerals and their hydration products. Considering the influence of these additions on hydration of clinker minerals and formation of hardened cement paste structure, dispersed wollastonite and diopside should be used as mineral additives. The hardness and, consequently, the elastic modulus of diopside are higher than that of hardened cement paste. As a result, there is a redistribution of stresses in the hardened cement paste interporous partitions and hardening, both the partitions and aerated concrete on the whole. The mineral additives introduction allowed to obtain the non-autoclaved aerated concrete with average density 580 kg/m3, compressive strength of 3.3 MPa and thermal conductivity of 0.131 W/(m.°C).

A summary of Selected Data: DSDP Legs 20-44,

DTIC Science & Technology

1980-09-01

water X 100 minerals may be applied in the future density water when the mineralogy and attenuation wt. wate r \\+ wt r ed. + salIt coefficients...in the future when densities of some common minerals are the exact quantitative mineralogy and listed in Harms and Choquette (1965), attenuation...different attenuation coefficient than were used to get a " ball park" answer that of calcite. for a particular sediment type, or for drilling

Effect of a novel phytase on growth performance, apparent metabolizable energy, and the availability of minerals and amino acids in a low-phosphorus corn-soybean meal diet for broilers.

PubMed

Rutherfurd, S M; Chung, T K; Thomas, D V; Zou, M L; Moughan, P J

2012-05-01

The addition of microbial phytase to diets for broiler chickens has been shown to improve the availability of phytate P, total P, some other minerals, and amino acids. In this study, the effect of a novel microbial phytase expressed by synthetic genes in Aspergillus oryzae on amino acid and mineral availability was assessed. Phytase was incorporated (1,000 and 2,000 U/kg) into low-P corn-soybean meal-based diets for broilers. Broilers received the experimental diets for 3 wk, and excreta were collected from d 18 to 21 for the determination of AME and mineral retention. On the 22nd day, the broilers were killed and the left leg removed and ileal digesta collected. Ileal phytate P and total P absorption, ileal amino acid digestibility, as well as the bone mineral content and bone mineral density were determined. Ileal phytate P absorption and absorbed phytate P content of the low-P corn-soybean meal diet were significantly (P < 0.05) higher after dietary inclusion of the novel phytase (49-60% and 65-77% higher, respectively). Apparent ileal total P absorption and apparent total P retention was 12 to 16% and 14 to 19% higher (P < 0.05), respectively, after dietary inclusion of phytase. The bone mineral content and bone mineral density in the tibia were 32 to 35% and 19 to 21% higher (P < 0.05), respectively, after dietary phytase inclusion. The apparent ileal digestibility of threonine, tyrosine, and histidine increased significantly (P < 0.05) by 14, 9, and 7%, respectively, after dietary inclusion of microbial phytase. Overall, the inclusion of a novel microbial phytase into a low-P corn-soybean meal diet for broiler chickens greatly increased phytate P and total P absorption, bone mineral content and density, as well as the digestibility of some amino acids.

Fe-Impregnated Mineral Colloids for Peroxide Activation: Effects of Mineral Substrate and Fe Precursor.

PubMed

Li, Yue; Machala, Libor; Yan, Weile

2016-02-02

Heterogeneous iron species at the mineral/water interface are important catalysts for the generation of reactive oxygen species at circumneutral pH. One significant pathway leading to the formation of such species arises from deposition of dissolved iron onto mineral colloids due to changes in redox conditions. This study investigates the catalytic properties of Fe impregnated on silica, alumina, and titania nanoparticles (as prototypical mineral colloids). Fe impregnation was carried out by immersing the mineral nanoparticles in dilute Fe(II) or Fe(III) solutions at pH 6 and 3, respectively, in an aerobic environment. The uptake of iron per unit surface area follows the order of nTiO2 > nAl2O3 > nSiO2 for both types of Fe precursors. Impregnation of mineral particles in Fe(II) solutions results in predominantly Fe(III) species due to efficient surface-mediated oxidation. The catalytic activity of the impregnated solids to produce hydroxyl radical (·OH) from H2O2 decomposition was evaluated using benzoic acid as a probe compound under dark conditions. Invariably, the rates of benzoic acid oxidation with different Fe-laden particles increase with the surface density of Fe until a critical density above which the catalytic activity approaches a plateau, suggesting active Fe species are formed predominantly at low surface loadings. The critical surface density of Fe varies with the mineral substrate as well as the aqueous Fe precursor. Fe impregnated on TiO2 exhibits markedly higher activity than its Al2O3 and SiO2 counterparts. The speciation of interfacial Fe is analyzed with diffuse reflectance UV-vis analysis and interpretation of the data in the context of benzoic oxidation rates suggests that the surface activity of the solids for ·OH generation correlates strongly with the isolated (i.e., mononuclear) Fe species. Therefore, iron dispersed on mineral colloids is a significant form of reactive iron surfaces in the aquatic environment.

Decline in bone mineral density with stress fractures in a woman on depot medroxyprogesterone acetate. A case report.

PubMed

Harkins, G J; Davis, G D; Dettori, J; Hibbert, M L; Hoyt, R A

1999-03-01

Depot medroxyprogesterone acetate is a popular contraceptive among young, physically active women. However, its administration has been linked to a relative decrease in estrogen levels. Since bone resorption is accelerated during hypoestrogenic states, there has been growing concern about the potential development of osteoporosis and fractures with the use of this contraceptive method. A physically active, 33-year-old woman demonstrated a 12.4% drop in femoral neck bone mineral density (BMD), 6.4% drop in lumbar BMD and 0.8% drop in total BMD with the subsequent development of a tibial stress fracture while on depot medroxyprogesterone acetate. Bone mineralization rapidly improved, and the stress fracture resolved with discontinuation of the medication. The long-term effects of depot medroxyprogesterone acetate on bone mineralization in physically active women should be evaluated more thoroughly.

Correlation between longitudinal, circumferential, and radial moduli in cortical bone: effect of mineral content.

PubMed

Macione, J; Depaula, C A; Guzelsu, N; Kotha, S P

2010-07-01

Previous studies indicate that changes in the longitudinal elastic properties of bone due to changes in mineral content are related to the longitudinal strength of bone tissue. Changes in mineral content are expected to affect bone tissue mechanical properties along all directions, albeit to different extents. However, changes in tissue mechanical properties along the different directions are expected to be correlated to one another. In this study, we investigate if radial, circumferential, and longitudinal moduli are related in bone tissue with varying mineral content. Plexiform bovine femoral bone samples were treated in fluoride ion solutions for a period of 3 and 12 days to obtain bones with 20% and 32% lower effective mineral contents. Transmission ultrasound velocities were obtained in the radial, circumferential, and longitudinal axes of bone and combined with measured densities to obtain corresponding tensorial moduli. Results indicate that moduli decreased with fluoride ion treatments and were significantly correlated to one another (r(2) radial vs. longitudinal = 0.80, r(2) circumferential vs. longitudinal = 0.90, r(2) radial vs. circumferential = 0.85). Densities calculated from using ultrasound parameters, acoustic impedance and transmission velocities, were moderately correlated to those measured by the Archimedes principle (r(2)=0.54, p<0.01). These results suggest that radial and circumferential ultrasound measurements could be used to determine the longitudinal properties of bone and that ultrasound may not be able to predict in vitro densities of bones containing unbonded mineral. Published by Elsevier Ltd.

The Use of Tunnel Muck as Industrial Raw Material: Two Case-Studies

NASA Astrophysics Data System (ADS)

Marini, P.; Bellopede, R.

2013-03-01

The re-use of rock as an industrial material requires more treatments than those foreseen for the reuse of muck as an aggregate for concrete and for road construction. The treatments always start with comminution, which has the goal of liberating the rock-forming minerals. Liberation is achieved with the appearance of grains which are composed of only one mineral. The subsequent treatment steps are based on the physical-mechanical-chemical properties of the different minerals, that is, density, magnetic susceptibility, wettability etc. Magnetic separation and flotation, the two techniques examined in this research, are the two most common techniques used in industrial mineral production plants. The mucks that were analysed are from the Omegna and Brennero tunnels, both of which are granitic rocks with different textures. From the analysis and comparison of the preliminary treatment results, it has been possible to optimise the treatment method. Petrographic, mineralogic and firing tests have been conducted to evaluate the obtained results. High-gradient magnetic separation (HGMS) on defined grain sizes appears to be suitable to obtain a product with a high feldspar-quartz content which could be used in the ceramic field.

The association between childhood fractures and adolescence bone outcomes: a population-based study, the Tromsø Study, Fit Futures.

PubMed

Christoffersen, T; Emaus, N; Dennison, E; Furberg, A-S; Gracia-Marco, L; Grimnes, G; Nilsen, O A; Vlachopoulos, D; Winther, A; Ahmed, L A

2018-02-01

Childhood fracture may predict persistent skeletal fragility, but it may also reflect high physical activity which is beneficial to bone development. We observe a difference in the relationship between previous fracture and bone outcome across physical activity level and sex. Further elaboration on this variation is needed. Childhood fracture may be an early marker of skeletal fragility, or increased levels of physical activity (PA), which are beneficial for bone mineral accrual. This study investigated the association between a previous history of childhood fracture and adolescent bone mineral outcomes by various PA levels. We recruited 469 girls and 492 boys aged 15-18 years to this study. We assessed PA levels by questionnaire and measured areal bone mineral density (aBMD) and bone mineral content (BMC) using dual-energy X-ray absorptiometry (DXA) at arm, femoral neck (FN), total hip (TH), and total body (TB) and calculated bone mineral apparent density (BMAD, g/cm 3 ). Fractures from birth to time of DXA measurements were retrospectively recorded. We analyzed differences among participants with and without fractures using independent sample t test. Multiple linear regression was used to examine the association between fractures and aBMD and BMC measurements according to adolescent PA. Girls with and without a previous history of fracture had similar BMC, aBMD, and BMAD at all sites. In multiple regression analyses stratified by physical activity intensity (PAi), there was a significant negative association between fracture and aBMD-TH and BMC-FN yet only in girls reporting low PAi. There was a significant negative association between forearm fractures, BMAD-FN, and BMAD-arm among vigorously active boys. Our findings indicate a negative association between childhood fractures and aBMD/BMC in adolescent girls reporting low PAi. In boys, such an association appears only in vigorously active participants with a history of forearm fractures.

Bone mineral density of vegetarian and non-vegetarian adults in Taiwan.

PubMed

Wang, Yuh-Feng; Chiu, Jainn-Shiun; Chuang, Mei-Hua; Chiu, Jing-Er; Lin, Chin-Lon

2008-01-01

Diet is thought to be one of the leading causes of bone mineral loss in aging people. In this study, we explored the potential impact of a vegetarian diet on bone mineral density (BMD) in adult Taiwanese men and women. This was a cross-sectional study of the relationship between diet (vegetarian versus non-vegetarian) and BMD and the incidence of osteoporosis. Bone mineral density was determined in a cohort of 1865 adult male and female patients who underwent routine examination in a regional teaching hospital in Taiwan between February 2003 and February 2004. Subjects with definite vertebral problems, known osteopathy, or poor posture were excluded. Dual-energy X-ray absorptiometry (DEXA) was used to determine BMD, on the right hip in men and on lumbar vertebrae L2 to L4 in women. The subjects were grouped according to sex and diet, and were then stratified by age within each of the four groups. The outcome measures were the BMD value and the incidence of osteopenia or osteoporosis according to defined criteria. Bone mineral density gradually declined with increasing age in Taiwanese men, while Taiwanese women showed a precipitous decrease in BMD after the 5th decade. However, no statistical differences in BMD were observed between vegetarians and non-vegetarians of either sex. The proportion of subjects with osteopenia or osteoporosis also appeared comparable between vegetarians and non-vegetarians of either sex. BMD shows an age-related decline in Taiwanese men and women, and eating a vegetarian diet does not appear to affect this decline.

Inhibition of estrogen biosynthesis with a potent aromatase inhibitor increases predicted adult height in boys with idiopathic short stature: a randomized controlled trial.

PubMed

Hero, Matti; Norjavaara, Ensio; Dunkel, Leo

2005-12-01

In males as well as in females, estrogen is an essential regulator of bone maturation, growth plate fusion, and cessation of longitudinal growth. Therefore, an increase in predicted adult height (PAH) may be achieved in short boys by blocking estrogen biosynthesis. We tested the hypothesis that a decrease in the rate of bone maturation and an increase in PAH can be achieved in boys with idiopathic short stature (ISS) by the method of blocking estrogen biosynthesis with an aromatase inhibitor. Secondarily, we investigated the effects of aromatase inhibition on bone mineralization. This was a prospective, double-blind, randomized, placebo (Pl)-controlled clinical study. The study was performed at a university hospital out-patient clinic. Thirty-one boys, aged 9.0-14.5 yr, with ISS were studied. The boys were treated with the aromatase inhibitor letrozole (Lz; 2.5 mg/d) or Pl for 2 yr. The main outcome measure was the change in PAH after 24 months of treatment. PAH increased by 5.9 cm (P < 0.0001), and height SD score for bone age increased by 0.7 SD score (P < 0.0001) in the Lz-treated boys, whereas no changes occurred in the respective measures in Pl-treated boys. Areal bone mineral density of the lumbar spine and femoral neck, assessed by dual-energy x-ray absorptiometry, increased in a similar fashion in both groups during the treatment, whereas bone mineral apparent density increased only in those taking Lz (median increase, 4.3%; P = 0.009). Treatment with the aromatase inhibitor Lz delays bone maturation and improves PAH in boys with ISS. No adverse effects on bone mineralization were evident after 2 yr of treatment.

Effects of host-plant population size and plant sex on a specialist leaf-miner

NASA Astrophysics Data System (ADS)

Bañuelos, María-José; Kollmann, Johannes

2011-03-01

Animal population density has been related to resource patch size through various hypotheses such as those derived from island biogeography and resource concentration theory. This theoretical framework can be also applied to plant-herbivore interactions, and it can be modified by the sex of the host-plant, and density-dependent relationships. Leaf-miners are specialised herbivores that leave distinct traces on infested leaves in the form of egg scars, mines, signs of predation and emergence holes. This allows the life cycle of the insect to be reconstructed and the success at the different stages to be estimated. The main stages of the leaf-miner Phytomyza ilicis were recorded in eleven populations of the evergreen host Ilex aquifolium in Denmark. Survival rates were calculated and related to population size, sex of the host plant, and egg and mine densities. Host population size was negatively related to leaf-miner prevalence, with larger egg and mine densities in small populations. Percentage of eggs hatching and developing into mines, and percentage of adult flies emerging from mines also differed among host populations, but were not related to population size or host cover. Feeding punctures left by adults were marginally more frequent on male plants, whereas egg scars and mines were more common on females. Overall survival rate from egg stage to adult emergence was higher on female plants. Egg density was negatively correlated with hatching, while mine density was positively correlated with emergence of the larvae. The inverse effects of host population size were not in line with predictions based on island biogeography and resource concentration theory. We discuss how a thorough knowledge of the immigration behaviour of this fly might help to understand the patterns found.

The frequency-domain approach for apparent density mapping

NASA Astrophysics Data System (ADS)

Tong, T.; Guo, L.

2017-12-01

Apparent density mapping is a technique to estimate density distribution in the subsurface layer from the observed gravity data. It has been widely applied for geologic mapping, tectonic study and mineral exploration for decades. Apparent density mapping usually models the density layer as a collection of vertical, juxtaposed prisms in both horizontal directions, whose top and bottom surfaces are assumed to be horizontal or variable-depth, and then inverts or deconvolves the gravity anomalies to determine the density of each prism. Conventionally, the frequency-domain approach, which assumes that both top and bottom surfaces of the layer are horizontal, is usually utilized for fast density mapping. However, such assumption is not always valid in the real world, since either the top surface or the bottom surface may be variable-depth. Here, we presented a frequency-domain approach for apparent density mapping, which permits both the top and bottom surfaces of the layer to be variable-depth. We first derived the formula for forward calculation of gravity anomalies caused by the density layer, whose top and bottom surfaces are variable-depth, and the formula for inversion of gravity anomalies for the density distribution. Then we proposed the procedure for density mapping based on both the formulas of inversion and forward calculation. We tested the approach on the synthetic data, which verified its effectiveness. We also tested the approach on the real Bouguer gravity anomalies data from the central South China. The top surface was assumed to be flat and was on the sea level, and the bottom surface was considered as the Moho surface. The result presented the crustal density distribution, which was coinciding well with the basic tectonic features in the study area.

Raman spectroscopy detects deterioration in biomechanical properties of bone in a glucocorticoid-treated mouse model of rheumatoid arthritis

NASA Astrophysics Data System (ADS)

Maher, Jason R.; Takahata, Masahiko; Awad, Hani A.; Berger, Andrew J.

2011-08-01

Although glucocorticoids are frequently prescribed for the symptomatic management of inflammatory disorders such as rheumatoid arthritis, extended glucocorticoid exposure is the leading cause of physician-induced osteoporosis and leaves patients at a high risk of fracture. To study the biochemical effects of glucocorticoid exposure and how they might affect biomechanical properties of the bone, Raman spectra were acquired from ex vivo tibiae of glucocorticoid- and placebo-treated wild-type mice and a transgenic mouse model of rheumatoid arthritis. Statistically significant spectral differences were observed due to both treatment regimen and mouse genotype. These differences are attributed to changes in the overall bone mineral composition, as well as the degree of phosphate mineralization in tibial cortical bone. In addition, partial least squares regression was used to generate a Raman-based prediction of each tibia's biomechanical strength as quantified by a torsion test. The Raman-based predictions were as accurate as those produced by microcomputed tomography derived parameters, and more accurate than the clinically-used parameter of bone mineral density. These results suggest that Raman spectroscopy could be a valuable tool for monitoring bone biochemistry in studies of bone diseases such as osteoporosis, including tests of drugs being developed to combat these diseases.

A case report of osteomalacia unmasking primary biliary cirrhosis.

PubMed

Pawlowska, M; Kapeluto, J E; Kendler, D L

2015-07-01

Osteomalacia, a metabolic bone disease characterized by the inability to mineralize new osteoid, can be caused by vitamin D deficiency. We report a patient with symptomatic, biochemical, and imaging evidence of osteomalacia due to vitamin D deficiency, who as a result of work up for bone disease was diagnosed with early primary biliary cirrhosis. Osteomalacia was treated with high-dose vitamin D and serial bone density scans showed evidence of increasing bone mineral density suggesting osteoid mineralization in response to treatment. The diagnosis of cholestatic liver disease should be considered in all patients presenting with osteomalacia due to vitamin D deficiency, particularly if other cholestatic liver enzymes are elevated in addition to alkaline phosphatase.

Application of the health belief model and social cognitive theory for osteoporosis preventive nutritional behaviors in a sample of Iranian women

PubMed Central

Jeihooni, Ali Khani; Hidarnia, Alireza; Kaveh, Mohammad Hossein; Hajizadeh, Ebrahim; Askari, Alireza

2016-01-01

Background: Osteoporosis is the most common metabolic bone disease. The purpose of this study is to investigate the health belief model (HBM) and social cognitive theory (SCT) for osteoporosis preventive nutritional behaviors in women. Materials and Methods: In this quasi-experimental study, 120 patients who were women and registered under the health centers in Fasa City, Fars Province, Iran were selected. A questionnaire consisting of HBM constructs and the constructs of self-regulation and social support from SCT was used to measure nutrition performance. Bone mineral density was recorded at the lumbar spine and femur. The intervention for the experimental group included 10 educational sessions of 55-60 min of speech, group discussion, questions and answers, as well as posters and educational pamphlets, film screenings, and PowerPoint displays. Data were analyzed using SPSS 19 via Chi-square test, independent t-test, and repeated measures analysis of variance (ANOVA) at a significance level of 0.05. Results: After intervention, the experimental group showed a significant increase in the HBM constructs, self-regulation, social support, and nutrition performance, compared to the control group. Six months after the intervention, the value of lumbar spine bone mineral density (BMD) T-score increased to 0.127 in the experimental group, while it reduced to −0.043 in the control group. The value of the hip BMD T-score increased to 0.125 in the intervention group, but it decreased to −0.028 in the control group. Conclusions: This study showed the effectiveness of HBM and constructs of self-regulation and social support on adoption of nutrition behaviors and increase in the bone density to prevent osteoporosis. PMID:27095985

Influence of acidifying or alkalinizing diets on bone mineral density and urine relative supersaturation with calcium oxalate and struvite in healthy cats.

PubMed

Bartges, Joseph W; Kirk, Claudia A; Cox, Sherry K; Moyers, Tamberlyn D

2013-10-01

To evaluate the influence of acidifying or alkalinizing diets on bone mineral density and urine relative supersaturation (URSS) with calcium oxalate and struvite in healthy cats. 6 castrated male and 6 spayed female cats. 3 groups of 4 cats each were fed diets for 12 months that differed only in acidifying or alkalinizing properties (alkalinizing, neutral, and acidifying). Body composition was estimated by use of dual energy x-ray absorptiometry, and 48-hour urine samples were collected for URSS determination. Urine pH differed significantly among diet groups, with the lowest urine pH values in the acidifying diet group and the highest values in the alkalinizing diet group. Differences were not observed in other variables except urinary ammonia excretion, which was significantly higher in the neutral diet group. Calcium oxalate URSS was highest in the acidifying diet group and lowest in the alkalinizing diet group; struvite URSS was not different among groups. Diet was not significantly associated with bone mineral content or density. Urinary undersaturation with calcium oxalate was achieved by inducing alkaluria. Feeding an alkalinizing diet was not associated with URSS with struvite. Bone mineral density and calcium content were not adversely affected by diet; therefore, release of calcium from bone caused by feeding an acidifying diet may not occur in healthy cats.

Bone mass and vitamin D levels in Parkinson’s disease: is there any difference between genders?

PubMed Central

Ozturk, Erhan Arif; Gundogdu, Ibrahim; Tonuk, Burak; Kocer, Bilge Gonenli; Tombak, Yasemin; Comoglu, Selcuk; Cakci, Aytul

2016-01-01

[Purpose] The aim of this study was to determine the bone mineral density, vitamin D level, and frequencies of osteopenia and osteoporosis in patients with Parkinson’s disease and to compare male and female patients with the controls separately. [Subjects and Methods] One hundred fifteen Parkinson’s disease patients (47 males, 68 females; age range: 55–85 years) and 117 age- and gender-matched controls (47 males, 70 females) were enrolled in the study. Bone mineral density measured by dual-energy X-ray absorptiometry and serum D vitamin levels of each participant were recorded. [Results] The mean lumbar spine, femur neck, and total femur bone mineral density levels, T-scores, and vitamin D levels were found to be significantly lower in Parkinson’s disease patients in both genders. Furthermore, osteoporosis rates were found be significantly higher only in female Parkinson’s disease patients compared with female controls. [Conclusion] Data from the present study revealed that while osteoporosis was significantly higher only in female Parkinson’s disease patients, all Parkinson’s disease patients had lower bone mineral density scores and vitamin D levels compared with the controls regardless of gender, suggesting that clinicians should pay attention to the osteoporosis risk in Parkinson’s disease and that adequate preventive measures should be taken in order to limit the future risk due to osteoporotic fractures. PMID:27630398

Choice of osteoblast model critical for studying the effects of electromagnetic stimulation on osteogenesis in vitro.

PubMed

Bique, Anna-Maria; Kaivosoja, Emilia; Mikkonen, Marko; Paulasto-Kröckel, Mervi

2016-01-01

The clinical benefits of electromagnetic field (EMF) therapy in enhancing osteogenesis have been acknowledged for decades, but agreement regarding the underlying mechanisms continues to be sought. Studies have shown EMFs to promote osteoblast-like cell proliferation, or contrarily, to induce differentiation and enhance mineralization. Typically these disparities have been attributed to methodological differences. The present paper argues the possibility that the chosen osteoblast model impacts stimulation outcome. Phenotypically immature cells, particularly at low seeding densities, appear to be prone to EMF-amplified proliferation. Conversely, mature cells at higher densities seem to be predisposed to earlier onset differentiation and mineralization. This suggests that EMFs augment ongoing processes in cell populations. To test this hypothesis, mature SaOS-2 cells and immature MC3T3-E1 cells at various densities, with or without osteo-induction, were exposed to sinusoidal 50 Hz EMF. The exposure stimulated the proliferation of MC3T3-E1 and inhibited the proliferation of SaOS-2 cells. Baseline alkaline phosphatase (ALP) expression of SaOS-2 cells was high and rapidly further increased with EMF exposure, whereas ALP effects in MC3T3-E1 cells were not seen until the second week. Thus both cell types responded differently to EMF stimulation, corroborating the hypothesis that the phenotypic maturity and culture stage of cells influence stimulation outcome.

Analysis of LCT-13910 genotypes and bone mineral density in ancient skeletal materials

PubMed Central

Mnich, Barbara; Spinek, Anna Elżbieta; Chyleński, Maciej; Sommerfeld, Aleksandra; Dabert, Miroslawa; Szostek, Krzysztof

2018-01-01

The relation of LCT-13910 genotypes and bone mineral density (BMD) has been the subject of modern-day human population studies, giving inconsistent results. In the present study we analyze for the first time a relation of LCT-13910 genotypes and BMD in historical skeletal individuals. Ancient population might be a model for testing this association due to elimination of non-natural factors affecting bone density. Among 22 medieval individuals from Sanok churchyard (South-Eastern Poland; dated from XIV to XVII c. AD) we identified 4 individuals with osteoporosis (mean BMD = 0.468 g/cm2, SD = 0.090), 10 individuals with osteopenia (mean BMD = 0.531 g/cm2, SD = 0.066) and 8 individuals with normal BMD values (mean BMD = 0,642 g/cm2, SD = 0.060). Analyses of BMD and LCT-13910 genotypes revealed that mean BMD was the highest (0.583 g/cm2, SD = 0.065) in the individuals with lactose tolerance genotypes (TT and CT). We also found possible association of lower BMD at the radius and CC genotypes due to higher but not statistically significant frequency of osteoporosis in the lactose intolerant group (p = 0.60). Statistically significant correlation was found between BMD and females aged 20–35 years, with tendency to reduce BMD with age (p = 0.02). PMID:29708972

Ovariectomy-Induced Osteopenia Influences the Middle and Late Periods of Bone Healing in a Mouse Femoral Osteotomy Model.

PubMed

Pang, Jian; Ye, Meina; Gu, Xinfeng; Cao, Yuelong; Zheng, Yuxin; Guo, Hailing; Zhao, Yongfang; Zhan, Hongsheng; Shi, Yinyu

2015-08-01

It is known that bone healing is delayed in the presence of osteoporosis in humans. However, due to the complexities of the healing of osteoporotic fractures, animal models may be more appropriate for studying the effects of osteoporosis in more detail and for testing drugs on the fracture repair process. The purpose of this study was to investigate the influence of ovariectomy-induced osteopenia in bone healing in an open femoral osteotomy model, and to test the feasibility of this model for evaluating the healing process under osteopenic conditions. Ovariectomized (OVX) mouse models were employed to assess the effects of osteopenia on fracture healing, A mid-shaft femur osteotomy model was also established 3 weeks after ovariectomy as an osteopenic fracture group (OVX group). Femurs were then harvested at 2 weeks and 6 weeks after fracture for X-ray radiography, micro-computed tomography (micro-CT), histology, and biomechanical analysis. A sham-operated group (sham group) was used for comparison. The OVX mice had significantly lower bone volume density (BVF), volumetric bone mineral density (vBMD), and tissue mineral density (TMD) in the fracture calluses at 6 weeks (p<0.05), and similar trend was observed in 2 weeks. Additionally, larger calluses in OVX animals were observed via micro-CT and X-ray, but these did not result in better healing outcomes, as determined by biomechanical test at 6 weeks. Histological images of the healing fractures in the OVX mice found hastening of broken end resorption and delay of hard callus remodeling. The impaired biomechanical measurements in the OVX group (p<0.05) were consistent with micro-CT measurements and radiographic scoring, which also indicated delay in fracture healing of the OVX group. This study provided evidence that ovariectomy-induced osteopenia impair the middle and late bone healing process. These data also supported the validity of the mouse femoral osteotomy model in evaluating the process of bone healing under osteopenic conditions.

Effects of whole-body vibration training on physical function, bone and muscle mass in adolescents and young adults with cerebral palsy.

PubMed

Gusso, Silmara; Munns, Craig F; Colle, Patrícia; Derraik, José G B; Biggs, Janene B; Cutfield, Wayne S; Hofman, Paul L

2016-03-03

We performed a clinical trial on the effects of whole-body vibration training (WBVT) on muscle function and bone health of adolescents and young adults with cerebral palsy. Forty participants (11.3-20.8 years) with mild to moderate cerebral palsy (GMFCS II-III) underwent 20-week WBVT on a vibration plate for 9 minutes/day 4 times/week at 20 Hz (without controls). Assessments included 6-minute walk test, whole-body DXA, lower leg pQCT scans, and muscle function (force plate). Twenty weeks of WBVT were associated with increased lean mass in the total body (+770 g; p = 0.0003), trunk (+410 g; p = 0.004), and lower limbs (+240 g; p = 0.012). Bone mineral content increased in total body (+48 g; p = 0.0001), lumbar spine (+2.7 g; p = 0.0003), and lower limbs (+13 g; p < 0.0001). Similarly, bone mineral density increased in total body (+0.008 g/cm(2); p = 0.013), lumbar spine (+0.014 g/cm(2); p = 0.003), and lower limbs (+0.023 g/cm(2); p < 0.0001). Participants reduced the time taken to perform the chair test, and improved the distance walked in the 6-minute walk test by 11% and 35% for those with GMFCS II and III, respectively. WBVT was associated with increases in muscle mass and bone mass and density, and improved mobility of adolescents and young adults with cerebral palsy.

Effects of spaceflight and Insulin-like Growth Factor-1 on rat bone properties

NASA Astrophysics Data System (ADS)

Bateman, Ted A.; Ayers, Reed A.; Spetzler, Michael L.; Simske, Steven J.; Zimmerman, Robert J.

1997-01-01

Spaceflight induces bone degradation which is analogous to an accelerated onset of osteoporosis in humans (Tilton et al., 1980). In rats, decreased bone formation is indicative of reduced osteoblast activity (Morey and Baylink, 1978). Chiron Corporation (Emeryville, CA) is interested in using the microgravity environment of low-Earth-orbit to test its therapeutic drug, Insulin-like Growth Factor-1 (IGF-1). This pharmaceutic is known to promote osteoblast activity (Schmid et al., 1984) and therefore may encourage bone growth in rats. Chiron sponsored the Immune.3 payload on STS-73 (May 19-29, 1996) through its Center for Space Commercialization (CSC) partner BioServe Space Technologies (University of Colorado and Kansas State University) to investigate the effects of IGF-1 on mitigating the skeletal degradation that affects rats and humans during spaceflight. Twelve rats were flown for 10 days using two Animal Enclosure Modules (AEMs) provided by NASA Ames Research Center. Of the twelve, six received 1.4 mg/day of IGF-1; the other six saline. Sixteen vivarium ground controls received the same treatment on a one day delay. Rat femora and tibiae were examined for bone mineral density via DXA scan. Femora and humeri were measured for physical and compositional properties, as well as mechanically tested in three point flexure. Quantitative histomorphometric examination of tibiae, humeri, fibulae, ribs and cranial bone; and microhardness testing on tibiae and humeri are currently in progress. Flight humeri and vivarium femora were significantly larger than their counterparts; however, significant differences in mechanical properties and mineral density were not concurrent to these mass changes.

Bone mineral density, chemical composition and biomechanical properties of the tibia of female rats exposed to cadmium since weaning up to skeletal maturity.

PubMed

Brzóska, M M; Majewska, K; Moniuszko-Jakoniuk, J

2005-10-01

The influence of exposure to cadmium (Cd) during skeletal development on the risk of bone fractures at the stage of skeletal maturity was investigated on a female rat model of human exposure. The tibias of rats treated with 1, 5 or 50 mg Cd/l in drinking water for 3, 6, 9 and 12 months (since weaning) were used. The exposure to Cd dose- and time-dependently influenced the tibia bone mineral density (BMD) and chemical composition. In skeletally matured animals, at each level of the exposure to Cd, the BMD at the whole tibia and its diaphysis as well as the percentage of minerals content in the bone, including the content of zinc, copper and iron, were decreased compared to control. Moreover, in the 50 mg Cd/l group, the percentage of organic components content increased. The Cd-induced changes, at all levels of exposure, resulted in weakening in the yield strength and fracture strength of the tibia (a three-point bending test of the diaphysis and compression test with vertical loading) of the skeletally matured females. A very important and clinically useful finding of this study is that a decrease (even by several percent) in the tibia BMD results in weakness in the bone biomechanical properties and that the BMD may predict the risk of its fracture at the exposure to Cd. Moreover, the results together with our previous findings seem to suggest that tibia, due to higher vulnerability of its diaphysis, compared to the femoral diaphysis, to damage by Cd may be more useful than femur to investigate the effect of Cd on the cortical bone. The present study revealed that a low exposure to Cd (1 mg Cd/l), corresponding to low human environmental exposure, during the skeletal development affects the tibia mineral status leading to weakening in its mechanical properties at the skeletal maturity. The findings allow for the conclusion that environmental exposure to Cd during childhood and adolescence may enhance the risk of low BMD and fractures at adulthood.

Material Modeling of Stony Meteorites for Mechanical Properties

NASA Astrophysics Data System (ADS)

Agrawal, P.

2016-12-01

To assess the threat posed by an asteroid entering Earth's atmosphere, one must predict if, when, and how it fragments during entry. A comprehensive understanding of the asteroid material properties is needed to achieve this objective. At present, the meteorite material found on earth are the only objects (other than synthetic meteorites) from an entering asteroid that can be used as representative material and be tested inside a laboratory setting. Due to limited number of meteorites available for testing it is difficult to develop a material model that can be purely based on statistics from the test data. Therefore, we are developing computational models to determine the effective material properties of stony meteorites and in turn deduce the properties of asteroids. The internal structure of meteorites are very complex. They consists of several minerals that include the silica based materials such as Olivine, Pyroxene, Feldspar that are found in terrestrial rocks, as well as Fe-Ni based minerals such as Kamacite, Troilite and Taenite that are unique to meteorites. Each of these minerals have different densities and mechanical properties. In addition, the meteorites have different phases that can be summarized as chondrules, metal and matrix. The meteorites have varying degree of porosity and pre-cracked structure. In order to account for diverse petrology of the meteorites a unique methodology is developed the form of unit cell model. The unit cell is representative volume that accounts for diverse minerals, porosity, and matrix composition inside a meteorite. All the minerals and phases inside these unit cells are randomly distributed. Several hundreds of Monte-Carlo simulations are performed to generate the effective mechanical properties such as Young's Modulus and Poisson's Ratio of the unit cell. Stress-strain curves as well as strength estimates are generated based on the unit cell models. These estimates will used as material models for full scale modeling of atmospheric entry for asteroids. Terrestrial analogs such as Basalt and Gabbro are being used to validate the unit cell methodology. Structural tests are also being performed on some of the meteorites including Tamdakht and Mbole to validate the predictions from unit cell models.

Physicochemical characterization of mineral deposits in human ligamenta flava.

PubMed

Orzechowska, Sylwia; Wróbel, Andrzej; Kozieł, Marcin; Łasocha, Wiesław; Rokita, Eugeniusz

2018-05-01

The aim of our study was the detailed characterization of calcium deposits in ligamenta flava. The use of microcomputed tomography allowed extending the routine medical investigations to characterize mineral grains in the microscopic scale. A possible connection between spinal stenosis and ligament mineralization was investigated. The studies were carried out on 24 surgically removed ligamentum flavum samples divided into control and stenosis groups. Physicochemical characterization of the inorganic material was performed using X-ray fluorescence, X-ray diffraction, and Fourier transform infrared spectroscopy. The minerals were present in 14 of 24 ligament samples, both in stenosis and control groups. The inorganic substance constitutes on average ~0.1% of the sample volume. The minerals are scattered in the soft tissue matrix without any regular pattern. It was confirmed that minerals possess an internal structure and consist of the organic material and small inorganic grains mixture. The physicochemical analyses show that the predominant crystalline phase was hydroxyapatite (HAP). In the stenosis group calcium pyrophosphate dehydrate (CPPD) was identified. Both structures were never present in a single sample. Two different crystal structures suggest two independent processes of mineralization. The formation of CPPD may be treated as a more intense process since CPPD minerals are characterized by bigger values of the structural parameters and higher density than HAP deposits. The formation of HAP minerals is a soft tissue degeneration process that begins, in some cases, at early age or may not occur at all. Various density and volume of mineral grains indicate that the mineralization process does not occur in a constant environment and proceeds with various speeds. The formation of minerals in ligamenta flava is not directly associated with diagnosed spinal canal stenosis.

The effects of phytoestrogen isoflavones on bone density in women: a double-blind, randomized, placebo-controlled trial.

PubMed

Atkinson, Charlotte; Compston, Juliet E; Day, Nicholas E; Dowsett, Mitch; Bingham, Sheila A

2004-02-01

Isoflavone phytoestrogen therapy has been proposed as a natural alternative to hormone replacement therapy (HRT). HRT has a beneficial effect on bone, but few trials in humans have investigated the effects of isoflavones on bone. The objective of the study was to determine the effect on bone density of a red clover-derived isoflavone supplement that provided a daily dose of 26 mg biochanin A, 16 mg formononetin, 1 mg genistein, and 0.5 mg daidzein for 1 y. Effects on biochemical markers of bone turnover and body composition were also studied. Women aged 49-65 y (n = 205) were enrolled in a double-blind, randomized, placebo-controlled trial; 177 completed the trial. Bone density, body composition, bone turnover markers, and diet were measured at baseline and after 12 mo. Loss of lumbar spine bone mineral content and bone mineral density was significantly (P = 0.04 and P = 0.03, respectively) lower in the women taking the isoflavone supplement than in those taking the placebo. There were no significant treatment effects on hip bone mineral content or bone mineral density, markers of bone resorption, or body composition, but bone formation markers were significantly increased (P = 0.04 and P = 0.01 for bone-specific alkaline phosphatase and N-propeptide of collagen type I, respectively) in the intervention group compared with placebo in postmenopausal women. Interactions between treatment group and menopausal status with respect to changes in other outcomes were not significant. These data suggest that, through attenuation of bone loss, isoflavones have a potentially protective effect on the lumbar spine in women.

Comparison of Bone Grafts From Various Donor Sites in Human Bone Specimens.

PubMed

Kamal, Mohammad; Gremse, Felix; Rosenhain, Stefanie; Bartella, Alexander K; Hölzle, Frank; Kessler, Peter; Lethaus, Bernd

2018-05-14

The objective of the current study was to compare the three-dimensional (3D) morphometric microstructure in human cadaveric bone specimens taken from various commonly utilized donor sites for autogenous bone grafting. Autogenous bone grafts can be harvested from various anatomic sites and express heterogeneous bone quality with a specific 3D microstructure for each site. The long-term structural integrity and susceptibility to resorption of the graft depend on the selected donor bone. Micro-computed tomography generates high-resolution datasets of bone structures and calcifications making this modality versatile for microarchitecture analysis and quantification of the bone. Six bone specimens, 10 mm in length, where anatomically possible, were obtained from various anatomical sites from 10 human dentate cadavers (4 men, 6 women, mean age 69.5 years). Specimens were scanned using a micro-computed tomography device and volumetrically reconstructed. A virtual cylindrical inclusion was reconstructed to analyze the bone mineral density and structural morphometric analysis using bone indices: relative bone volume, surface density, trabecular thicknesses, and trabecular separation. Calvarial bone specimens showed the highest mineral density, followed by the chin, then mandibular ramus then the tibia, whereas iliac crest and maxillary tuberosity had lower bone mineral densities. The pairwise comparison revealed statistically significant differences in the bone mineral density and relative bone volume index in the calvaria, mandibular ramus, mandibular symphysis groups when compared with those in the iliac crest and maxillary tuberosity, suggesting higher bone quality in the former groups than in the latter; tibial specimens expressed variable results.

Bone mineral content and bone mineral density in adolescent girls with anorexia nervosa--a longitudinal study.

PubMed

Jagielska, G; Wolańczyk, T; Komender, J; Tomaszewicz-Libudzic, C; Przedlacki, J; Ostrowski, K

2001-08-01

Total body and lumbar spine bone mineral density (BMD-TB, BMD-L) and total body bone mineral content (BMC-TB) were measured to establish the course of bone demineralization in anorexia nervosa and the clinical factors influencing BMC-TB and BMD changes during treatment. Forty-two girls with DSM III-R anorexia nervosa, age 14.7+/-2.4 years. BMC-TB, BMD-TB and BMD-L were measured in approximately 7-month intervals for 27.8+/-4.1 months using DXA. Despite nutritional improvement, there was an initial decrease of BMD-L, and no change in BMC-TB and BMD-TB. an increase in BMC-TB and BMD was observed after approx. 21 months from the beginning of the study. The improvement in BMC-TB and BMD was related to changes in nutritional status and was significantly marked in younger patients, with earlier anorexia onset and before menarche.

Physical and thermal properties of mud-dominant sediment from the Joetsu Basin in the eastern margin of the Japan Sea

NASA Astrophysics Data System (ADS)

Goto, Shusaku; Yamano, Makoto; Morita, Sumito; Kanamatsu, Toshiya; Hachikubo, Akihiro; Kataoka, Satsuki; Tanahashi, Manabu; Matsumoto, Ryo

2017-12-01

Physical properties (bulk density and porosity) and thermal properties (thermal conductivity, heat capacity, specific heat, and thermal diffusivity) of sediment are crucial parameters for basin modeling. We measured these physical and thermal properties for mud-dominant sediment recovered from the Joetsu Basin, in the eastern margin of the Japan Sea. To determine thermal conductivity, heat capacity, and thermal diffusivity, the dual-needle probe method was applied. Grain density and grain thermal properties for the mud-dominant sediment were estimated from the measured physical and thermal properties by applying existing models of physical and thermal properties of sediment. We suggest that the grain density, grain thermal conductivity, and grain thermal diffusivity depend on the sediment mineral composition. Conversely, the grain heat capacity and grain specific heat showed hardly any dependency on the mineral composition. We propose empirical formulae for the relationships between: thermal diffusivity and thermal conductivity, and heat capacity and thermal conductivity for the sediment in the Joetsu Basin. These relationships are different from those for mud-dominant sediment in the eastern flank of the Juan de Fuca Ridge presented in previous work, suggesting a difference in mineral composition, probably mainly in the amount of quartz, between the sediments in that area and the Joetsu Basin. Similar studies in several areas of sediments with various mineral compositions would enhance knowledge of the influence of mineral composition.

Replication of Previous Genome-wide Association Studies of Bone Mineral Density in Premenopausal American Women

PubMed Central

Ichikawa, Shoji; Koller, Daniel L; Padgett, Leah R; Lai, Dongbing; Hui, Siu L; Peacock, Munro; Foroud, Tatiana; Econs, Michael J

2010-01-01

Bone mineral density (BMD) achieved during young adulthood (peak BMD) is one of the major determinants of osteoporotic fracture in later life. Genetic variants associated with BMD have been identified by three recent genome-wide association studies. The most significant single-nucleotide polymorphisms (SNPs) from these studies were genotyped to test whether they were associated with peak BMD in premenopausal American women. Femoral neck and lumbar spine BMD were determined by dual-energy X-ray absorptiometry in two groups of premenopausal women: 1524 white women and 512 black women. In premenopausal white women, two SNPs in the C6orf97/ESR1 region were significantly associated with BMD (p < 4.8 × 10−4), with suggestive evidence for CTNNBL1 and LRP5 (p < .01). Evidence of association with one of the two SNPs in the C6orf97/ESR1 region also was observed in premenopausal black women. Furthermore, SNPs in SP7 and a chromosome 4 intergenic region showed suggestive association with BMD in black women. Detailed analyses of additional SNPs in the C6orf97/ESR1 region revealed multiple genomic blocks independently associated with femoral neck and lumbar spine BMD. Findings in the three published genome-wide association studies were replicated in independent samples of premenopausal American women, suggesting that genetic variants in these genes or regions contribute to peak BMD in healthy women in various populations. © 2010 American Society for Bone and Mineral Research. PMID:20200978

Association of Protein Intake with Bone Mineral Density and Bone Mineral Content among Elderly Women: The OSTPRE Fracture Prevention Study.

PubMed

Isanejad, M; Sirola, J; Mursu, J; Kröger, H; Tuppurainen, M; Erkkilä, A T

2017-01-01

It has been hypothesized that high protein intakes are associated with lower bone mineral content (BMC). Previous studies yield conflicting results and thus far no studies have undertaken the interaction of body mass index (BMI) and physical activity with protein intakes in relation to BMC and bone mineral density (BMD). To evaluate the associations of dietary total protein (TP), animal protein (AP) and plant protein (PP) intakes with BMC and BMD and their changes. We tested also the interactions of protein intake with, obesity (BMI ≤30 vs. >30 kg/m2) and physical activity level (passive vs. active). Design/ Setting: Prospective cohort study (Osteoporosis Risk-Factor and Fracture-Prevention Study). Participants/measures: At the baseline, 554 women aged 65-72 years filled out a 3-day food record and a questionnaire covering data on lifestyle, physical activity, diseases, and medications. Intervention group received calcium 1000 mg/d and cholecalciferol 800 IU for 3 years. Control group received neither supplementation nor placebo. Bone density was measured at baseline and year 3, using dual energy x-ray absorptiometry. Multivariable regression analyses were conducted to examine the associations between protein intake and BMD and BMC. In cross-sectional analyses energy-adjusted TP (P≤0·029) and AP (P≤0·045) but not PP (g/d) were negatively associated with femoral neck (FN) BMD and BMC. Women with TP≥1·2 g/kg/body weight (BW) (Ptrend≤0·009) had lower FN, lumbar spine (LS) and total BMD and BMC. In follow-up analysis, TP (g/kg/BW) was inversely associated with LS BMD and LS BMC. The detrimental associations were stronger in women with BMI<30 kg/m2. In active women, TP (g/kg/BW) was positively associated with LS BMD and FN BMC changes. This study suggests detrimental associations between protein intake and bone health. However, these negative associations maybe counteracted by BMI>30 kg/m2 and physical activity.

Standard Practice for the Selection and Application of Marine Deck Coverings

DTIC Science & Technology

1992-07-01

floors to reduce the transmission of noise and vibrations. These typically consist of layers of mineral wool or mineral wool panel sections with a...crew efficiency. Floating deck systems are generally composed of an insulating material such as mineral wool that are laid loose on the structural...Chapter II-2, Part A, Regulation 3(c). Sound Reduction Index - 44 dB Sound Insulation Index (Ia) - 47 dB Density of Mineral Wool - 10 pounds per

A Film Depositional Model of Permeability for Mineral Reactions in Unsaturated Media.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Freedman, Vicky L.; Saripalli, Prasad; Bacon, Diana H.

2004-11-15

A new modeling approach based on the biofilm models of Taylor et al. (1990, Water Resources Research, 26, 2153-2159) has been developed for modeling changes in porosity and permeability in saturated porous media and implemented in an inorganic reactive transport code. Application of the film depositional models to mineral precipitation and dissolution reactions requires that calculations of mineral films be dynamically changing as a function of time dependent reaction processes. Since calculations of film thicknesses do not consider mineral density, results show that the film porosity model does not adequately describe volumetric changes in the porous medium. These effects canmore » be included in permeability calculations by coupling the film permeability models (Mualem and Childs and Collis-George) to a volumetric model that incorporates both mineral density and reactive surface area. Model simulations demonstrate that an important difference between the biofilm and mineral film models is in the translation of changes in mineral radii to changes in pore space. Including the effect of tortuosity on pore radii changes improves the performance of the Mualem permeability model for both precipitation and dissolution. Results from simulation of simultaneous dissolution and secondary mineral precipitation provides reasonable estimates of porosity and permeability. Moreover, a comparison of experimental and simulated data show that the model yields qualitatively reasonable results for permeability changes due to solid-aqueous phase reactions.« less

The effect of nutritional rickets on bone mineral density.

PubMed

Thacher, Tom D; Fischer, Philip R; Pettifor, John M

2014-11-01

Nutritional rickets is caused by impaired mineralization of growing bone. The effect of nutritional rickets on areal bone mineral density (aBMD) has not been established. Our objective was to determine if aBMD is lower in children with active rickets than in healthy control children. We expected that the reduction in aBMD would vary between the radial and ulnar metaphyses near the growth plates and the proximal diaphyses. Case-control study. Primary care outpatient department of a teaching hospital in Jos, Nigeria. Nigerian children with radiographically-confirmed rickets were compared with a reference group of control children without rickets from the same community. Forearm bone density measurements were performed in all children with pDXA. Age, sex, and height-adjusted bone density parameters were compared between children with rickets and control subjects. A total of 264 children with active rickets (ages 13-120 months) and 660 control children (ages 11-123 months) were included. In multivariate analyses controlling for height, age, and gender, rickets was associated with a 4% greater bone area and 7% lower aBMD of the radial and ulnar metaphyses compared with controls (P < .001). The effects of rickets on the diaphyses of the radius and ulna were more pronounced with an 11% greater bone area, 21% lower aBMD, and 24% lower bone mineral apparent density than controls (P < .001). In children with rickets, aBMD values were unrelated to dairy product intake or serum calcium, phosphorus, alkaline phosphatase, or 25-hydroxyvitamin D. Metaphyseal aBMD was positively associated with radiographic severity score, attributed to bone edge detection artifact by densitometry in active rickets. Rickets results in increased bone area and reduced aBMD, which are more pronounced in the diaphyseal than in the metaphyseal regions of the radius and ulna, consistent with secondary hyperparathyroidism, generalized osteoid expansion and impaired mineralization.

Validity of height loss as a predictor for prevalent vertebral fractures, low bone mineral density, and vitamin D deficiency.

PubMed

Mikula, A L; Hetzel, S J; Binkley, N; Anderson, P A

2017-05-01

Many osteoporosis-related vertebral fractures are unappreciated but their detection is important as their presence increases future fracture risk. We found height loss is a useful tool in detecting patients with vertebral fractures, low bone mineral density, and vitamin D deficiency which may lead to improvements in patient care. This study aimed to determine if/how height loss can be used to identify patients with vertebral fractures, low bone mineral density, and vitamin D deficiency. A hospital database search in which four patient groups including those with a diagnosis of osteoporosis-related vertebral fracture, osteoporosis, osteopenia, or vitamin D deficiency and a control group were evaluated for chart-documented height loss over an average 3 1/2 to 4-year time period. Data was retrieved from 66,021 patients (25,792 men and 40,229 women). A height loss of 1, 2, 3, and 4 cm had a sensitivity of 42, 32, 19, and 14% in detecting vertebral fractures, respectively. Positive likelihood ratios for detecting vertebral fractures were 1.73, 2.35, and 2.89 at 2, 3, and 4 cm of height loss, respectively. Height loss had lower sensitivities and positive likelihood ratios for detecting low bone mineral density and vitamin D deficiency compared to vertebral fractures. Specificity of 1, 2, 3, and 4 cm of height loss was 70, 82, 92, and 95%, respectively. The odds ratios for a patient who loses 1 cm of height being in one of the four diagnostic groups compared to a patient who loses no height was higher for younger and male patients. This study demonstrated that prospective height loss is an effective tool to identify patients with vertebral fractures, low bone mineral density, and vitamin D deficiency although a lack of height loss does not rule out these diagnoses. If significant height loss is present, the high positive likelihood ratios support a further workup.

Pre-sarcopenia and bone mineral density in adults submitted to hematopoietic stem cell transplantation.

PubMed

Pereira, Cristiane Pavan; Amaral, Denise Johnsson Campos; Funke, Vaneuza Araujo Moreira; Borba, Victória Zeghbi Cochenski

The aim of this study was to evaluate the prevalence of pre-sarcopenia and bone mineral density after hematopoietic stem cell transplantation. The study group consisted of over 18-year-old patients who had been submitted to allogeneic transplantation at least one year previously. Patients and healthy controls were matched by sex, ethnic background, age, and body mass index. Body composition and bone mineral density were measured by dual-energy X-ray absorptiometry. A 24-h food recall and food frequency survey were performed. The biochemical evaluation included calcium, parathormone and vitamin D. Eighty-seven patients (52 men; age: 37.2±12.7 years; body mass index: 25±4.5kg/m 2 ) were compared to 68 controls [31 men; age 35.4±15.5 years (p=0.467); body mass index 25.05±3.7kg/m 2 (p=0.927)]. There was no significant difference in the dietary intake between patients and controls. The mean levels of vitamin D were 23.5±10.3ng/mL; 29 patients (41.0%) had insufficient and 26 (37.14%) deficient levels. A higher prevalence of reduced bone mineral density was observed in 24 patients (25%) compared to 12 controls (19.1% - p<0.001). Pre-sarcopenia was diagnosed in 14 (14.4%) patients and none of the controls (p=0.05). There was a higher prevalence of pre-sarcopenia (66%) in patients with grades III and IV compared to those with grades 0-II graft-versus-host disease (10.9%) (p=0.004). patients submitted to transplantation had a higher prevalence of pre-sarcopenia and greater changes in bone mineral density compared to controls; the severity of graft-versus-host disease had an impact on the prevalence of pre-sarcopenia. Copyright © 2017 Associação Brasileira de Hematologia, Hemoterapia e Terapia Celular. Published by Elsevier Editora Ltda. All rights reserved.

Revised Reference Curves for Bone Mineral Content and Areal Bone Mineral Density According to Age and Sex for Black and Non-Black Children: Results of the Bone Mineral Density in Childhood Study

PubMed Central

Kalkwarf, Heidi J.; Gilsanz, Vicente; Lappe, Joan M.; Oberfield, Sharon; Shepherd, John A.; Frederick, Margaret M.; Huang, Xiangke; Lu, Ming; Mahboubi, Soroosh; Hangartner, Thomas; Winer, Karen K.

2011-01-01

Context: Deficits in bone acquisition during growth may increase fracture risk. Assessment of bone health during childhood requires appropriate reference values relative to age, sex, and population ancestry to identify bone deficits. Objective: The objective of this study was to provide revised and extended reference curves for bone mineral content (BMC) and areal bone mineral density (aBMD) in children. Design: The Bone Mineral Density in Childhood Study was a multicenter longitudinal study with annual assessments for up to 7 yr. Setting: The study was conducted at five clinical centers in the United States. Participants: Two thousand fourteen healthy children (992 males, 22% African-Americans) aged 5–23 yr participated in the study. Intervention: There were no interventions. Main Outcome Measures: Reference percentiles for BMC and aBMD of the total body, lumbar spine, hip, and forearm were obtained using dual-energy x-ray absorptiometry for Black and non-Black children. Adjustment factors for height status were also calculated. Results: Extended reference curves for BMC and aBMD of the total body, total body less head, lumbar spine, total hip, femoral neck, and forearm for ages 5–20 yr were constructed relative to sex and age for Black and non-Black children. Curves are similar to those previously published for 7–17 year olds. BMC and aBMD values were greater for Black vs. non-Black children at all measurement sites. Conclusions: We provide here dual-energy x-ray absorptiometry reference data on a well-characterized cohort of 2012 children and adolescents. These reference curves provide the most robust reference values for the assessment and monitoring of bone health in children and adolescents in the literature to date. PMID:21917867

Correlation Between Analytical and Thermodynamicaly Calculated Values of Density For Chloride-sodium Brines

NASA Astrophysics Data System (ADS)

Dudukalov, A.

Leakage from pipe-lines, nonhermetic wells and other industrial equipment of highly mineralized chloride-sodium brines, incidentally produced during oil field exploitation is one of the main source of fresh groundwater contamination on the Arlan oil field. Thermodynamic calculation, aimed to define more exactly brines chemical composi- tion and density was carried out by FREZCHEM2 program (Mironenko M.V. et al. 1997). Five brines types with mineralization of 137.9, 181.2, 217.4, 243.7, 267.8 g/l and density of 1.176, 1.09, 1.135, 1.153, 1.167 g/cm3 correspondingly were used. It is necessary to note that preliminarily chemical compositions of two last brines were corrected according to their mineralization. During calculations it was determined the following density values of brines: 1.082, 1.114, 1.131, 1.146, 1.158 g/cm3 conse- quently. Obtained results demonstrate the significant discrepancy in experimental and model estimates. Significant excess of anions over cations in experimental data indicates a major prob- lem with the analytical measurements. During calculations it was analyzed the possi- bility of changes in brines density depending on editing to cations or deducting from anions requisite amount of agent for keeping charge balance equal to zero. Received results demonstrate that in this case brines density can change on 0.004-0.011 g/cm3.

Preservation and promotion of bone formation in the mandible as a response to a novel calcium-phosphate based biomaterial in mineral deficiency induced low bone mass male versus female rats

PubMed Central

Srinivasan, Kritika; Naula, Diana P.; Mijares, Dindo Q.; Janal, Malvin N.; LeGeros, Raquel Z.; Zhang, Yu

2016-01-01

Calcium and other trace mineral supplements have previously demonstrated to safely improve bone quality. We hypothesize that our novel calcium-phosphate based biomaterial (SBM) preserves and promotes mandibular bone formation in male and female rats on mineral deficient diet (MD). Sixty Sprague-Dawley rats were randomly assigned to receive one of three diets (n = 10): basic diet (BD), MD or mineral deficient diet with 2% SBM. Rats were sacrificed after 6 months. Micro-Computed Tomography (μCT) was used to evaluate bone volume and 3D-microarchitecture while microradiography (Faxitron) was used to measure bone mineral density from different sections of the mandible. Results showed that bone quality varied with region, gender and diet. MD reduced bone mineral density (BMD) and volume and increased porosity. SBM preserved BMD and bone mineral content (BMC) in the alveolar bone and condyle in both genders. In the alveolar crest and mandibular body, while preserving more bone in males, SBM also significantly supplemented female bone. Results indicate that mineral deficiency leads to low bone mass in skeletally immature rats, comparatively more in males. Furthermore, SBM administered as a dietary supplement was effective in preventing mandibular bone loss in all subjects. This study suggests that the SBM preparation has potential use in minimizing low peak bone mass induced by mineral deficiency and related bone loss irrespective of gender. PMID:26914814

The influence of birth weight and length on bone mineral density and content in adolescence: The Tromsø Study, Fit Futures.

PubMed

Christoffersen, Tore; Ahmed, Luai A; Daltveit, Anne Kjersti; Dennison, Elaine M; Evensen, Elin K; Furberg, Anne-Sofie; Gracia-Marco, Luis; Grimnes, Guri; Nilsen, Ole-Andreas; Schei, Berit; Tell, Grethe S; Vlachopoulos, Dimitris; Winther, Anne; Emaus, Nina

2017-12-01

The influence of birth weight and length on bone mineral parameters in adolescence is unclear. We found a positive association between birth size and bone mineral content, attenuated by lifestyle factors. This highlights the impact of environmental stimuli and lifestyle during growth. The influence of birth weight and length on bone mineral density and content later in life is unclear, especially in adolescence. This study evaluated the impact of birth weight and length on bone mineral density and content among adolescents. We included 961 participants from the population-based Fit Futures study (2010-2011). Dual-energy X-ray absorptiometry (DXA) was used to measure bone mineral density (BMD) and bone mineral content (BMC) at femoral neck (FN), total hip (TH) and total body (TB). BMD and BMC measures were linked with birth weight and length ascertained from the Medical Birth Registry of Norway. Linear regression models were used to investigate the influence of birth parameters on BMD and BMC. Birth weight was positively associated with BMD-TB and BMC at all sites among girls; standardized β coefficients [95% CI] were 0.11 [0.01, 0.20] for BMD-TB and 0.15 [0.06, 0.24], 0.18 [0.09, 0.28] and 0.29 [0.20, 0.38] for BMC-FN, TH and TB, respectively. In boys, birth weight was positively associated with BMC at all sites with estimates of 0.10 [0.01, 0.19], 0.12 [0.03, 0.21] and 0.15 [0.07, 0.24] for FN, TH and TB, respectively. Corresponding analyses using birth length as exposure gave significantly positive associations with BMC at all sites in both sexes. The significant positive association between birth weight and BMC-TB in girls, and birth length and BMC-TB in boys remained after multivariable adjustment. We found a positive association between birth size and BMC in adolescence. However, this association was attenuated after adjustment for weight, height and physical activity during adolescence.

Disordered eating, menstrual disturbances, and low bone mineral density in dancers: a systematic review.

PubMed

Hincapié, Cesar A; Cassidy, J David

2010-11-01

To assemble and synthesize the best evidence on the epidemiology, diagnosis, prognosis, treatment, and prevention of disordered eating, menstrual disturbances, and low bone mineral density in dancers. Medline, CINAHL, PsycINFO, Embase, and other electronic databases were searched from 1966 to 2010 using key words such as "dance," "dancer," "dancing," "eating disorders," "menstruation disturbances," and "bone density." In addition, the reference lists of relevant studies were examined, specialized journals were hand-searched, and the websites of major dance associations were scanned for relevant information. Citations were screened for relevance using a priori criteria, and relevant studies were critically reviewed for scientific merit by the best evidence synthesis method. After 2748 abstracts were screened, 124 articles were reviewed, and 23 (18.5%) of these were accepted as scientifically admissible (representing 19 unique studies). Data from accepted studies were abstracted into evidence tables relating to prevalence and associated factors; incidence and risk factors; diagnosis; and prevention of disordered eating, menstrual disturbances, and/or low bone mineral density in dancers. The scientifically admissible studies consisted of 13 (68%) cross-sectional studies and 6 (32%) cohort studies. Disordered eating and menstrual disturbances are common in dancers. The lifetime prevalence of any eating disorder was 50% in professional dancers, while the point prevalence ranged between 13.6% and 26.5% in young student dancers. In their first year of intensive dance training, 32% of university-level dancers developed a menstrual disturbance. The incidence of disordered eating and low bone mineral density in dancers is unknown. Several potential risk factors are suggested by the literature, but there is little compelling evidence for any of these. There is preliminary evidence that multifaceted sociocultural prevention strategies may help decrease the incidence of disordered eating. The dance medicine literature is heterogeneous. The best available evidence suggests that disordered eating, menstrual disturbances, and low bone mineral density are important health issues for dancers at all skill levels. Future research would benefit from clear and relevant research questions being addressed with appropriate study designs and better reporting of studies in line with current scientific standards. Copyright © 2010 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Hypermineralization and High Osteocyte Lacunar Density in Osteogenesis Imperfecta Type V Bone Indicate Exuberant Primary Bone Formation.

PubMed

Blouin, Stéphane; Fratzl-Zelman, Nadja; Glorieux, Francis H; Roschger, Paul; Klaushofer, Klaus; Marini, Joan C; Rauch, Frank

2017-09-01

In contrast to "classical" forms of osteogenesis imperfecta (OI) types I to IV, caused by a mutation in COL1A1/A2, OI type V is due to a gain-of-function mutation in the IFITM5 gene, encoding the interferon-induced transmembrane protein 5, or bone-restricted interferon-inducible transmembrane (IFITM)-like protein (BRIL). Its phenotype distinctly differs from OI types I to IV by absence of blue sclerae and dentinogenesis imperfecta, by the occurrence of ossification disorders such as hyperplastic callus and forearm interosseous membrane ossification. Little is known about the impact of the mutation on bone tissue/material level in untreated and bisphosphonate-treated patients. Therefore, investigations of transiliac bone biopsy samples from a cohort of OI type V children (n = 15, 8.7 ± 4 years old) untreated at baseline and a subset (n = 8) after pamidronate treatment (2.6 years in average) were performed. Quantitative backscattered electron imaging (qBEI) was used to determine bone mineralization density distribution (BMDD) as well as osteocyte lacunar density. The BMDD of type V OI bone was distinctly shifted toward a higher degree of mineralization. The most frequently occurring calcium concentration (CaPeak) in cortical (Ct) and cancellous (Cn) bone was markedly increased (+11.5%, +10.4%, respectively, p < 0.0001) compared to healthy reference values. Treatment with pamidronate resulted in only a slight enhancement of mineralization. The osteocyte lacunar density derived from sectioned bone area was elevated in OI type V Ct and Cn bone (+171%, p < 0.0001; +183.3%, p < 0.01; respectively) versus controls. The high osteocyte density was associated with an overall immature primary bone structure ("mesh-like") as visualized by polarized light microscopy. In summary, the bone material from OI type V patients is hypermineralized, similar to other forms of OI. The elevated osteocyte lacunar density in connection with lack of regular bone lamellation points to an exuberant primary bone formation and an alteration of the bone remodeling process in OI type V. © 2017 American Society for Bone and Mineral Research. © 2017 American Society for Bone and Mineral Research.

Mineral features of connective dental hard tissues in hypoplastic amelogenesis imperfecta.

PubMed

Kammoun, R; Behets, C; Mansour, L; Ghoul-Mazgar, S

2018-04-01

To explore the mineral features of dentin and cementum in hypoplastic Amelogenesis imperfecta AI teeth. Forty-four (44) teeth cleaned and free of caries were used: 20 control and 24 affected by hypoplastic amelogenesis imperfecta. Thirty-two teeth were studied by pQCT, cut in sections, and analyzed under microradiography, polarized light microscopy, and confocal Raman spectroscopy. Eight teeth were observed under scanning electron microscope. Four teeth were used for an X-ray diffraction. The mineral density data were analyzed statistically with the Mann-Whitney U test, using GraphPad InStat software. Both coronal dentin and radicular dentin were less mineralized in AI teeth when compared to control (respectively 6.2% and 6.8%; p < .001). Root dentinal walls were thin and irregular, while the cellular cementum layers were thick, reaching sometimes the cervical region of the tooth. Regular dentinal tubules and sclerotic dentin areas were noticed. Partially tubular or cellular dysplastic dentin and hyper-, normo-, or hypomineralized areas were noticed in the inter-radicular areas of hypoplastic AI teeth. The main mineral component was carbonate hydroxyapatite as explored by Raman spectroscopy and X-ray diffraction. Dentin and cementum in hypoplastic AI teeth are (i) hypomineralized, (ii) constituted of carbonate hydroxyapatite, and (iii) of non-homogenous structure. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd. All rights reserved.

Osteoporosis management and fractures in the Métis of Ontario, Canada.

PubMed

Jandoc, Racquel; Jembere, Nathaniel; Khan, Saba; Russell, Storm J; Allard, Yvon; Cadarette, Suzanne M

2015-01-01

Half of Métis citizens, compared to less than 10 % of the general population of Ontario, reside in northern regions, with little access to bone mineral density (BMD) testing. Métis citizens had lower sex-specific and age-standardized rates of BMD testing, yet similar rates of fracture (both sexes) and pharmacotherapy (women only). To examine osteoporosis management and common osteoporosis-related fractures among Métis citizens compared to the general population of older adults residing in Ontario. We linked healthcare (medical and pharmacy) utilization and administrative (demographic) databases with the Métis Nation of Ontario citizenship registry to estimate osteoporosis management (bone mineral density [BMD] testing, pharmacotherapy) and fractures (hip, humerus, radius/ulna) among adults aged ≥50 years, from April 1, 2006 to March 31, 2011. Pharmacotherapy data were limited to residents aged ≥65 years. Sex-specific and age-standardized rates were compared between the Métis and the general population. Multivariable logistic regression was used to compare rates of BMD testing after controlling for differences in age and region of residence between the Métis and the general population. We studied 4219 Métis citizens (55 % men), and 140 (3 %) experienced a fracture. Half of Métis citizens, compared to less than 10 % of the general population of Ontario, resided in northern regions. We identified significantly lower sex-specific and age-standardized rates of BMD testing among Métis compared to the general population, yet found little difference in fracture rates (both sexes) or pharmacotherapy (women only). Differences in BMD testing disappeared after adjusting for region of residence among women yet remained significant among men. Despite finding significantly lower rates of osteoporosis management among men, Métis men and women were found to have similar age-standardized fracture rates to the general population.

The Association of Fat and Lean Tissue With Whole Body and Spine Bone Mineral Density Is Modified by HIV Status and Sex in Children and Youth.

PubMed

Jacobson, Denise L; Lindsey, Jane C; Coull, Brent A; Mulligan, Kathleen; Bhagwat, Priya; Aldrovandi, Grace M

2018-01-01

HIV-infected (HIV-pos) male children/youth showed lower bone mineral density at sexual maturity than HIV-uninfected (HIV-neg) females. It is not known whether complications of HIV disease, including abnormal body fat distribution, contribute to lower bone accrual in male HIV-pos adolescents. In a cross-sectional study, we evaluated the relationship between body composition (fat and lean mass) and bone mass in HIV-pos and HIV-neg children/youth and determined if it is modified by HIV status and sex. We used generalized estimating equations to simultaneously model the effect of fat/lean mass on multiple bone outcomes, including total body bone mineral density and bone mineral content and spine bone mineral density. We evaluated effect modification by HIV and sex. The analysis cohort consisted of 143 HIV-neg and 236 HIV-pos, of whom 55% were black non-Hispanic and 53% were male. Ages ranged from 7 to < 25 years. Half of the children/youth were at Tanner stage 1 and 20% at Tanner 5. Fat mass was more strongly positively correlated with bone mass in HIV-neg than HIV-pos children/youth and these relationships were more evident for total body bone than spine outcomes. Within HIV strata, fat mass and bone were more correlated in female than male children/youth. The relationship between lean mass and bone varied by sex, but not by HIV status. HIV disease diminishes the positive relationship of greater fat mass on bone mass in children/youth. Disruptions in body fat distribution, which are common in HIV disease, may have an impact on bone accretion during pubertal development.

[Bone diseases].

PubMed

Uebelhart, Brigitte; Rizzoli, René

2016-01-13

Calcium intake shows a small impact on bone mineral density and fracture risk. Denosumab is a more potent inhibitor of bone resorption than zoledronate. Abaloparatide, PTHrP analog, increases bone mineral density and decreases fracture incidence. Teriparatide could be delivered via a transdermic device. Romosozumab and odanacatib improve calculated bone strength. Sequential or combined treatments with denosumab and teriparatide could be of interest, but not denosumab followed by teriparatide. Fibrous dysplasia, Paget disease and hypophosphatasia are updated, as well as atypical femoral fracture and osteonecrosis of the jaw.

Enhanced Androgen Signaling with Androgen Receptor Overexpression in the Osteoblast Lineage Controls Skeletal Turnover, Matrix Quality, and Bone Architecture

DTIC Science & Technology

2005-12-01

the BMD of female-to-male transsexuals treated with ‘male’ levels of testosterone increased to normal male levels at cortical sites [35]. Finally, men...Testosterone increases bone mineral density in female-to- male transsexuals : a case series of 15 subjects.Clin Endocrinol (Oxf) 2004, 61:560-566. 35...Ruetsche A, Kneubuehl R, Birkhaeuser M, Lippuner K: Cortical and trabecular bone mineral density in transsexuals after long-term cross-sex hormonal treatment

Calcium and Dairy Products Consumption and Association with Total Hip Bone Mineral Density in Women from Kosovo

PubMed Central

Bahtiri, Elton; Islami, Hilmi; Hoxha, Rexhep; Bytyqi, Hasime Qorraj-; Sermaxhaj, Faton; Halimi, Enis

2014-01-01

Background and objective: There is paucity of evidence in southeastern Europe and Kosovo regarding dairy products consumption and association with bone mineral density (BMD). Therefore, the objective of present study was to assess calcium intake and dairy products consumption and to investigate relationship with total hip BMD in a Kosovo women sample. Methods: This cross-sectional study included a sample of 185 women divided into respective groups according to total hip BMD. All the study participants completed a food frequency questionnaire and underwent dual-energy X-ray absorptiometry (DEXA) to estimate BMD. Nonparametric tests were performed to compare characteristics of the groups. Results: The average dietary calcium intake was 818.41 mg/day. Only 16.75% of the subjects met calcium recommended dietary reference intakes (DRIs). There were no significant differences between low BMD group and normal BMD group regarding average dietary calcium intake, but it was significantly higher in BMDT3 subgroup than in BMDT2 and BMDT1 subgroups. Conclusions: The results of this study demonstrate significant relationship of daily dietary calcium intake with upper BMD tertile. Further initiatives are warranted from this study to highlight the importance of nutrition education. PMID:25568548

[Relationship among anthropometric and gluco-metabolic parameters, bone mineral density and endometriosis].

PubMed

Nava-González, Edna J; de la Garza-Casas, Yolanda E; Salazar-Montalvo, Raúl G; Gallegos-Cabriales, Esther C

2013-01-01

women with endometriosis may have a decreased bone mineral density (BMD). Several studies have shown that accumulation of adipose tissue profoundly affects BMD. It has also been documented that excess body fat is associated with risk of developing endometriosis. The aim was to analyze the relationship between BMD, fat mass, and the insulin-glucose axis in women with endometriosis. thirty women with a diagnosis of endometriosis established by surgery were enrolled to participate in an observational prospective study. Anthropometry was performed to determine body mass index, and a dual X-ray densitometry to collect data on body composition and BMD. Glucose and insulin determinations were performed. Women were divided in two groups: with normal weight (n = 18) or overweight (n = 12). For the analysis of the results, we used descriptive statistics and Pearson's test. normal weight/overweight: mean age 32.5/35.2 years; body mass index 21.5/30.2; adiposity index: 27.7 %/36.1 %; fat mass index: 35.4/45.8 %; overweight women showed a significant value with p < 0.05. overweight, high values of adiposity index and fat mass index were related to endometriosis. This could support the hypothesis about a common pathogenesis among endometriosis, osteoporosis, diabetes and obesity.

Opportunities for exercise during pullet rearing, Part II: Long-term effects on bone characteristics of adult laying hens at the end-of-lay.

PubMed

Casey-Trott, T M; Korver, D R; Guerin, M T; Sandilands, V; Torrey, S; Widowski, T M

2017-08-01

Osteoporosis in laying hens has been a production and welfare concern for several decades. The objective of this study was to determine whether differing opportunities for exercise during pullet rearing influences long-term bone quality characteristics in end-of-lay hens. A secondary objective was to assess whether differing opportunities for exercise in adult housing systems alters bone quality characteristics in end-of-lay hens. Four flock replicates of 588 Lohmann Selected Leghorn-Lite pullets were reared in either conventional cages (Conv) or an aviary rearing system (Avi) and placed into conventional cages (CC), 30-bird furnished cages (FC-S), or 60-bird furnished cages (FC-L) for adult housing. Wing and leg bones were collected at the end-of-lay to quantify bone composition and strength using quantitative computed tomography and bone breaking strength (BBS). At the end-of-lay, Avi hens had greater total and cortical cross-sectional area (P < 0.05) for the radius and tibia, greater total bone mineral content of the radius (P < 0.001), and greater tibial cortical bone mineral content (P = 0.029) than the Conv hens; however, total bone mineral density of the radius (P < 0.001) and cortical bone mineral density of the radius and tibia (P < 0.001) were greater in the Conv hens. Hens in the FC-L had greater total bone mineral density for the radius and tibia (P < 0.05) and greater trabecular bone mineral density for the radius (P = 0.027), compared to hens in the FC-S and CC. Total bone mineral content of the tibia (P = 0.030) and cortical bone mineral content of the radius (P = 0.030) and tibia (P = 0.013) were greater in the FC-L compared to the CC. The humerus of Conv hens had greater BBS than the Avi hens (P < 0.001), and the tibiae of FC-L and FC-S hens had greater BBS than CC hens (P = 0.006). Increased opportunities for exercise offered by the aviary rearing system provided improved bone quality characteristics lasting through to the end-of-lay. © The Author 2017. Published by Oxford University Press on behalf of Poultry Science Association.

Bone mineral density and metabolic indices in hyperthyroidism.

PubMed

Al-Nuaim, A; El-Desouki, M; Sulimani, R; Mohammadiah, M

1991-09-01

Hyperthyroidism can alter bone metabolism by increasing both bone resorption and formation. The increase in bone resorption predominates, leading to a decrease in bone mass. To assess the effect of hyperthyroidism on bone and mineral metabolism, we measured bone density using single photon absorptiometry in 30 untreated hyperthyroid patients. Patients were categorized into three groups based on sex and alkaline phosphatase levels: 44 sex- and age-matched subjects were used as controls. Bone densities were significanlty lower in all patient groups compared with controls. Alkaline phosphatase was found to be a useful marker for assessing severity of bone disease in hyperthyroid patients as there is significant bone density among patients with higher alkaline phosphatase value. Hyperthyroidism should be considered in the differential diagnosis of unexplained alkaline phophatase activity.

The Influence of Local Bone Density on the Outcome of One Hundred and Fifty Proximal Humeral Fractures Treated with a Locking Plate.

PubMed

Kralinger, Franz; Blauth, Michael; Goldhahn, Jörg; Käch, Kurt; Voigt, Christine; Platz, Andreas; Hanson, Beate

2014-06-18

There is biomechanical evidence that bone density predicts the mechanical failure of implants. The aim of this prospective study was to evaluate the influence of local bone mineral density on the rate of mechanical failure after locking plate fixation of proximal humeral fractures. We enrolled 150 patients who were from fifty to ninety years old with a closed, displaced proximal humeral fracture fixed with use of a locking plate from July 2007 to April 2010. There were 118 women and thirty-two men who had a mean age of sixty-nine years. Preoperative computed tomography (CT) scans were done to assess bone mineral density of the contralateral humerus, and dual x-ray absorptiometry of the distal end of the radius of the unaffected arm was conducted within the first six weeks postoperatively. At follow-up evaluations at six weeks, three months, and one year postoperatively, pain, shoulder mobility, strength, and multiple functional and quality-of-life outcome measures (Disabilities of the Arm, Shoulder and Hand [DASH] questionnaire; Shoulder Pain and Disability Index [SPADI]; Constant score; and EuroQuol-5D [EQ-5D]) were done and standard radiographs were made. We defined mechanical failure as all complications related to bone quality experienced within one year. After locking plate fixation, fifty-three (35%) of 150 patients had mechanical failure; loss of reduction and secondary screw loosening with perforation were common. CT assessments of local bone mineral density showed no difference between patients with and without mechanical failure (89.82 versus 91.51 mg/cm 3 , respectively; p = 0.670). One-year DASH, SPADI, and Constant scores were significantly better for patients without mechanical failure (p ≤ 0.05). We did not find evidence of an association between bone mineral density and the rate of mechanical failures, which may suggest that patients with normal bone mineral density are less prone to sustain a proximal humeral fracture. Future studies should target other discriminating factors between patients with and without mechanical failure. Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence. Copyright © 2014 by The Journal of Bone and Joint Surgery, Incorporated.

Release adiabat measurements on minerals: The effect of viscosity

NASA Technical Reports Server (NTRS)

Jeanloz, R.; Ahrens, T. J.

1979-01-01

The current inversion of pressure-particle velocity data for release from a high pressure shock state to a pressure-density path is analyzed. It is assumed that the release process is isentropic. It was shown that for geological materials below stresses of 150 GPa, the effective viscosity must be 1000 kg/m/s in order that the viscous (irreversible) work carried out on the material in the shock state remains small compared to the mechanical work recovered upon adiabatic rarefaction. The available data pertaining to the offset of the Rayleigh line from the Hugoniot for minerals, the magnitude of the shear stress in the high pressure shock state for minerals, and the direct measurements of the viscosities of several engineering materials shocked to pressures below 150 GPa yield effective viscosities of 1000 kg/m/s or less. An inferance that this indicates that the conditions for isentropic release of minerals from shock states are achieved, and a conclusion that the application of the Riemann integral to obtain pressure-density states along the release adiabats of minerals in shock experiments is valid are made.

Techniques for deriving tissue structure from multiple projection dual-energy x-ray absorptiometry

NASA Technical Reports Server (NTRS)

Feldmesser, Howard S. (Inventor); Charles, Jr., Harry K. (Inventor); Beck, Thomas J. (Inventor); Magee, Thomas C. (Inventor)

2004-01-01

Techniques for deriving bone properties from images generated by a dual-energy x-ray absorptiometry apparatus include receiving first image data having pixels indicating bone mineral density projected at a first angle of a plurality of projection angles. Second image data and third image data are also received. The second image data indicates bone mineral density projected at a different second angle. The third image data indicates bone mineral density projected at a third angle. The third angle is different from the first angle and the second angle. Principal moments of inertia for a bone in the subject are computed based on the first image data, the second image data and the third image data. The techniques allow high-precision, high-resolution dual-energy x-ray attenuation images to be used for computing principal moments of inertia and strength moduli of individual bones, plus risk of injury and changes in risk of injury to a patient.

Common allelic variants of the vitamin receptor D gene rs7975232 (ApaI) do not influence bone mineral density figures in postmenopausal osteoporotic women.

PubMed

Pedrera-Canal, Maria; Moran, Jose M; Vera, Vicente; Roncero-Martin, Raul; Lavado-Garcia, Jesus M; Aliaga, Ignacio; Pedrera-Zamorano, Juan D

2015-01-01

This study examined the association between bone mineral density (BMD) and the rs7975232 (ApaI) polymorphism of the vitamin receptor D (VDR) gene. The polymorphism was detected using the real-time PCR TaqMan method. The rs7975232 genotype was determined in 274 postmenopausal osteoporotic Spanish women who were 60.53±8.02 years old. The observed genotype frequencies were in agreement with Hardy-Weinberg equilibrium (χ(2)=1.85, P=0.1736). There were no significant differences in the rs7975232 genotype groups in our total sample of osteoporotic women regarding age, years since menopause, height, weight, and BMD at femoral neck, femoral trochanter and lumbar spine. Significant differences were found in menarche age (aa vs Aa; P=0.008) and BMI (aa vs AA; P=0.029). We conclude that the VDR gene rs7975232 polymorphism is not related to figures of bone mineral density in postmenopausal osteoporotic Spanish women.

Genetics of osteoporosis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Urano, Tomohiko; Inoue, Satoshi, E-mail: INOUE-GER@h.u-tokyo.ac.jp; Department of Anti-Aging Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655

Highlights: • Single-nucleotide polymorphisms (SNPs) associated with osteoporosis were identified. • SNPs mapped close to or within VDR and ESR1 are associated with bone mineral density. • WNT signaling pathway plays a pivotal role in regulating bone mineral density. • Genetic studies will be useful for identification of new therapeutic targets. - Abstract: Osteoporosis is a skeletal disease characterized by low bone mineral density (BMD) and microarchitectural deterioration of bone tissue, which increases susceptibility to fractures. BMD is a complex quantitative trait with normal distribution and seems to be genetically controlled (in 50–90% of the cases), according to studies onmore » twins and families. Over the last 20 years, candidate gene approach and genome-wide association studies (GWAS) have identified single-nucleotide polymorphisms (SNPs) that are associated with low BMD, osteoporosis, and osteoporotic fractures. These SNPs have been mapped close to or within genes including those encoding nuclear receptors and WNT-β-catenin signaling proteins. Understanding the genetics of osteoporosis will help identify novel candidates for diagnostic and therapeutic targets.« less

Osteopenia and osteoporosis in people living with HIV: multiprofessional approach

PubMed Central

Lima, Ana Lucia Lei Munhoz; de Oliveira, Priscila Rosalba D; Plapler, Perola Grimberg; Marcolino, Flora Maria D Andrea; de Souza Meirelles, Eduardo; Sugawara, André; Gobbi, Riccardo Gomes; dos Santos, Alexandre Leme Godoy; Camanho, Gilberto Luis

2011-01-01

Increasing bone mineralization abnormalities observed among people living with HIV (PLWHIV) result from various factors relating to the host, the virus, and the antiretrovirals used. Today, HIV infection is considered to be a risk factor for bone mineralization disorders. The test most recommended for diagnosing osteoporosis is measurement of bone mineral density by means of dual energy X-ray absorptiometry at two sites. Osteoporosis treatment has the aims of bone mass improvement and fracture control. A combination of calcium and vitamin D supplementation may reduce the risk of fractures. Antiresorptive drugs act by blocking osteoclastic activity and reducing bone remodeling. On the other hand, bone-forming drugs stimulate osteoblastogenesis, thereby stimulating the formation of bone matrix. Mixed-action medications are those that are capable of both stimulating bone formation and inhibiting reabsorption. Antiresorptive drugs form the group of medications with the greatest quantity of scientific evidence confirming their efficacy in osteoporosis treatment. Physical activity is a health promotion strategy for the general population, but only preliminary data on its real value and benefit among PLWHIV are available, especially in relation to osteoporosis. PMID:22267944

Optical properties behavior of three optical filters and a mirror used in the internal optical head of a Raman laser spectrometer after exposed to proton radiation

NASA Astrophysics Data System (ADS)

Guembe, V.; Alvarado, C. G.; Fernández-Rodriguez, M.; Gallego, P.; Belenguer, T.; Díaz, E.

2017-11-01

The Raman Laser Spectrometer is one of the ExoMars Pasteur Rover's payload instruments that is devoted to the analytical analysis of the geochemistry content and elemental composition of the observed minerals provided by the Rover through Raman spectroscopy technique. One subsystem of the RLS instrument is the Internal Optical Head unit (IOH), which is responsible for focusing the light coming from the laser onto the mineral under analysis and for collecting the Raman signal emitted by the excited mineral. The IOH is composed by 4 commercial elements for Raman spectroscopy application; 2 optical filters provided by Iridian Spectral Technologies Company and 1 optical filter and 1 mirror provided by Semrock Company. They have been exposed to proton radiation in order to analyze their optical behaviour due to this hostile space condition. The proton irradiation test was performed following the protocol of LINES lab (INTA). The optical properties have been studied through transmittance, reflectance and optical density measurements, the final results and its influence on optical performances are presented.

Osteopenia and osteoporosis in people living with HIV: multiprofessional approach.

PubMed

Lima, Ana Lucia Lei Munhoz; de Oliveira, Priscila Rosalba D; Plapler, Perola Grimberg; Marcolino, Flora Maria D Andrea; de Souza Meirelles, Eduardo; Sugawara, André; Gobbi, Riccardo Gomes; Dos Santos, Alexandre Leme Godoy; Camanho, Gilberto Luis

2011-01-01

Increasing bone mineralization abnormalities observed among people living with HIV (PLWHIV) result from various factors relating to the host, the virus, and the antiretrovirals used. Today, HIV infection is considered to be a risk factor for bone mineralization disorders. The test most recommended for diagnosing osteoporosis is measurement of bone mineral density by means of dual energy X-ray absorptiometry at two sites. Osteoporosis treatment has the aims of bone mass improvement and fracture control. A combination of calcium and vitamin D supplementation may reduce the risk of fractures. Antiresorptive drugs act by blocking osteoclastic activity and reducing bone remodeling. On the other hand, bone-forming drugs stimulate osteoblastogenesis, thereby stimulating the formation of bone matrix. Mixed-action medications are those that are capable of both stimulating bone formation and inhibiting reabsorption. Antiresorptive drugs form the group of medications with the greatest quantity of scientific evidence confirming their efficacy in osteoporosis treatment. Physical activity is a health promotion strategy for the general population, but only preliminary data on its real value and benefit among PLWHIV are available, especially in relation to osteoporosis.

Sorptive fractionation of organic matter and formation of organo-hydroxy-aluminum complexes during litter biodegradation in the presence of gibbsite

NASA Astrophysics Data System (ADS)

Heckman, K.; Grandy, A. S.; Gao, X.; Keiluweit, M.; Wickings, K.; Carpenter, K.; Chorover, J.; Rasmussen, C.

2013-11-01

Solid and aqueous phase Al species are recognized to affect organic matter (OM) stabilization in forest soils. However, little is known about the dynamics of formation, composition and dissolution of organo-Al hydroxide complexes in microbially-active soil systems, where plant litter is subject to microbial decomposition in close proximity to mineral weathering reactions. We incubated gibbsite-quartz mineral mixtures in the presence of forest floor material inoculated with a native microbial consortium for periods of 5, 60 and 154 days. At each time step, samples were density separated into light (<1.6 g cm-3), intermediate (1.6-2.0 g cm-3), and heavy (>2.0 g cm-3) fractions. The light fraction was mainly comprised of particulate organic matter, while the intermediate and heavy density fractions contained moderate and large amounts of Al-minerals, respectively. Multi-method interrogation of the fractions indicated the intermediate and heavy fractions differed both in mineral structure and organic compound composition. X-ray diffraction analysis and SEM/EDS of the mineral component of the intermediate fractions indicated some alteration of the original gibbsite structure into less crystalline Al hydroxide and possibly proto-imogolite species, whereas alteration of the gibbsite structure was not evident in the heavy fraction. DRIFT, Py-GC/MS and STXM/NEXAFS results all showed that intermediate fractions were composed mostly of lignin-derived compounds, phenolics, and polysaccharides. Heavy fraction organics were dominated by polysaccharides, and were enriched in proteins, N-bearing compounds, and lipids. The source of organics appeared to differ between the intermediate and heavy fractions. Heavy fractions were enriched in 13C with lower C/N ratios relative to intermediate fractions, suggesting a microbial origin. The observed differential fractionation of organics among hydroxy-Al mineral types suggests that microbial activity superimposed with abiotic mineral-surface-mediated fractionation leads to strong density differentiation of organo-mineral complex composition even over the short time scales probed in these incubation experiments. The data highlight the strong interdependency of mineral transformation, microbial community activity, and organic matter stabilization during biodegradation.

Quantitative (31)P NMR spectroscopy and (1)H MRI measurements of bone mineral and matrix density differentiate metabolic bone diseases in rat models.

PubMed

Cao, Haihui; Nazarian, Ara; Ackerman, Jerome L; Snyder, Brian D; Rosenberg, Andrew E; Nazarian, Rosalynn M; Hrovat, Mirko I; Dai, Guangping; Mintzopoulos, Dionyssios; Wu, Yaotang

2010-06-01

In this study, bone mineral density (BMD) of normal (CON), ovariectomized (OVX), and partially nephrectomized (NFR) rats was measured by (31)P NMR spectroscopy; bone matrix density was measured by (1)H water- and fat-suppressed projection imaging (WASPI); and the extent of bone mineralization (EBM) was obtained by the ratio of BMD/bone matrix density. The capability of these MR methods to distinguish the bone composition of the CON, OVX, and NFR groups was evaluated against chemical analysis (gravimetry). For cortical bone specimens, BMD of the CON and OVX groups was not significantly different; BMD of the NFR group was 22.1% (by (31)P NMR) and 17.5% (by gravimetry) lower than CON. For trabecular bone specimens, BMD of the OVX group was 40.5% (by (31)P NMR) and 24.6% (by gravimetry) lower than CON; BMD of the NFR group was 26.8% (by (31)P NMR) and 21.5% (by gravimetry) lower than CON. No significant change of cortical bone matrix density between CON and OVX was observed by WASPI or gravimetry; NFR cortical bone matrix density was 10.3% (by WASPI) and 13.9% (by gravimetry) lower than CON. OVX trabecular bone matrix density was 38.0% (by WASPI) and 30.8% (by gravimetry) lower than CON, while no significant change in NFR trabecular bone matrix density was observed by either method. The EBMs of OVX cortical and trabecular specimens were slightly higher than CON but not significantly different from CON. Importantly, EBMs of NFR cortical and trabecular specimens were 12.4% and 26.3% lower than CON by (31)P NMR/WASPI, respectively, and 4.0% and 11.9% lower by gravimetry. Histopathology showed evidence of osteoporosis in the OVX group and severe secondary hyperparathyroidism (renal osteodystrophy) in the NFR group. These results demonstrate that the combined (31)P NMR/WASPI method is capable of discerning the difference in EBM between animals with osteoporosis and those with impaired bone mineralization. Copyright 2010 Elsevier Inc. All rights reserved.

Vertebral fractures assessed with dual-energy X-ray absorptiometry in patients with Addison's disease on glucocorticoid and mineralocorticoid replacement therapy.

PubMed

Camozzi, Valentina; Betterle, Corrado; Frigo, Anna Chiara; Zaccariotto, Veronica; Zaninotto, Martina; De Caneva, Erica; Lucato, Paola; Gomiero, Walter; Garelli, Silvia; Sabbadin, Chiara; Salvà, Monica; Costa, Miriam Dalla; Boscaro, Marco; Luisetto, Giovanni

2018-02-01

to assess bone damage and metabolic abnormalities in patients with Addison's disease given replacement doses of glucocorticoids and mineralocorticoids. A total of 87 patients and 81 age-matched and sex-matched healthy controls were studied. The following parameters were measured: urinary cortisol, serum calcium, phosphorus, creatinine, 24-h urinary calcium excretion, bone alkaline phosphatase, parathyroid hormone, serum CrossLaps, 25 hydroxyvitamin D, and 1,25 dihydroxyvitamin D. Clear vertebral images were obtained with dual-energy X-ray absorptiometry in 61 Addison's disease patients and 47 controls and assessed using Genant's classification. Nineteen Addison's disease patients (31.1%) had at least one morphometric vertebral fracture, as opposed to six controls (12.8%, odds ratio 3.09, 95% confidence interval 1.12-8.52). There were no significant differences in bone mineral density parameters at any site between patients and controls. In Addison's disease patients, there was a positive correlation between urinary cortisol and urinary calcium excretion. Patients with fractures had a longer history of disease than those without fractures. Patients taking fludrocortisone had a higher bone mineral density than untreated patients at all sites except the lumbar spine. Addison's disease patients have more fragile bones irrespective of any decrease in bone mineral density. Supra-physiological doses of glucocorticoids and longer-standing disease (with a consequently higher glucocorticoid intake) might be the main causes behind patients' increased bone fragility. Associated mineralocorticoid treatment seems to have a protective effect on bone mineral density.

Factors in daily physical activity related to calcaneal mineral density in men.

PubMed

Hutchinson, T M; Whalen, R T; Cleek, T M; Vogel, J M; Arnaud, S B

1995-05-01

To determine the factors in daily physical activity that influence the mineral density of the calcaneus, we recorded walking steps and the type and duration of exercise in 43 healthy 26-to 51-yr-old men. Areal (g.cm-2) calcaneal bone mineral density (CBMD) was measured by single energy x-ray densitometry (SXA, Osteon, Inc., Wahiawa, HI). Subjects walked a mean (+/- SD) of 7902 (+/- 2534) steps per day or approximately 3.9 (+/- 1.2) miles daily. Eight subjects reported no exercise activities. The remaining 35 subjects spent 143 (2-772) (median and range) min.wk-1 exercising. Twenty-eight men engaged in exercise activities that generate single leg peak vertical ground reaction forces (GRFz) of 2 or more body weights (high loaders, HL), and 15 reported exercise or daily activities that typically generate GRFz less than 1.5 body weights (low loaders, LL). CBMD was 12% higher in HL than LL (0.668 +/- 0.074 g.cm-2 vs 0.597 +/- 0.062 g.cm-2, P < 0.004). In the HL group, CBMD correlated to reported minutes of high load exercise (r = 0.41, P < 0.03). CBMD was not related to the number of daily walking steps (N = 43, r = 0.03, NS). The results of this study support the concept that the dominant factor in daily physical activity relating to bone mineral density is the participation in site specific high loading activities, i.e., for the calcaneus, high calcaneal loads.

Factors in Daily Physical Activity Related to Calcaneal Mineral Density in Men

NASA Technical Reports Server (NTRS)

Hutchinson, Teresa M.; Whalen, Robert T.; Cleek, Tammy M.; Vogel, John M.; Arnaud, Sara B.

1995-01-01

To determine the factors in daily physical activity that influence the mineral density of the calcaneus, we recorded walking steps and the type and duration of exercise in 43 healthy 26-to 51-yr-old men. Areal (g/sq cm) calcaneal bone mineral density (CBMD) was measured by single energy x-ray densitometry. Subjects walked a mean (+/- SD) of 7902(+/-2534) steps per day or approximately 3.9(+/-1.2) miles daily. Eight subjects reported no exercise activities. The remaining 35 subjects spent 143(2-772) (median and range) min/wk exercising. Twenty-eight men engaged in exercise activities that generate single leg peak vertical ground reaction forces (GRF(sub z)) of 2 or more body weights (high loaders, HL), and 15 reported exercise or daily activities that typically generate GRF(sub z) less than 1.5 body weights (low loaders, LL). CBMD was 12% higher in HL than LL (0.668 +/- 0.074 g/sq cm vs 0.597 +/- 0.062 g/sq cm, P less than 0.004). In the HL group, CBMD correlated to reported minutes of high load exercise (r = 0.41, P less than 0.03). CBMD was not related to the number of daily walking steps (N = 43, r = 0.03, NS). The results of this study support the concept that the dominant factor in daily physical activity relating to bone mineral density is the participation in site specific high loading activities, i.e., for the calcaneus, high calcaneal loads.

Exposure to cadmium and persistent organochlorine pollutants and its association with bone mineral density and markers of bone metabolism on postmenopausal women

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rignell-Hydbom, A., E-mail: anna.rignell-hydbom@med.lu.se; Skerfving, S.; Lundh, T.

Environmental contaminants such as cadmium and persistent organochlorine pollutants have been proposed as risk factors of osteoporosis, and women may be at an increased risk. To assess associations between exposure to cadmium and two different POPs (2,2',4,4',5,5'-hexachlorobiphenyl CB-153, 1,1-dichloro-2,2-bis(p-chlorophenyl)-ethylene p,p'-DDE), on one hand, and bone effects, on the other, in a population-based study among postmenopausal (60-70 years) Swedish women with biobanked blood samples. The study included 908 women and was designed to have a large contrast of bone mineral densities, measured with a single photon absorptiometry technique in the non-dominant forearm. Biochemical markers related to bone metabolism were analyzed inmore » serum. Exposure assessment was based on cadmium concentrations in erythrocytes and serum concentrations of CB-153 and p,p'-DDE. Cadmium was negatively associated with bone mineral density and parathyroid hormone, positively with the marker of bone resorption. However, this association disappeared after adjustment for smoking. The major DDT metabolite (p,p'-DDE) was positively associated with bone mineral density, an association which remained after adjustment for confounders, but the effect was weak. There was no evidence that the estrogenic congener (CB-153) was associated with any of the bone markers. In conclusion, no convincing associations were observed between cadmium and POPs, on one hand, and bone metabolism markers and BMD, on the other.« less

Does vitamin D supplementation improve bone density in vitamin D-deficient children? Protocol for an individual patient data meta-analysis.

PubMed

Winzenberg, Tania; Lamberg-Allardt, Christel; El-Hajj Fuleihan, Ghada; Mølgaard, Christian; Zhu, Kun; Wu, Feitong; Riley, Richard D

2018-01-23

Our previous study-level (aggregate data) meta-analysis suggested that vitamin D supplements may be beneficial for bone density specifically in children with vitamin D deficiency. However, the misclassification of vitamin D status inherent in study-level data means that the results are not definitive and cannot provide an accurate assessment of the size of any effect. Therefore, we propose to undertake an individual patient data (IPD) meta-analysis to determine whether the effect of vitamin D supplementation on bone density in children differs according to baseline vitamin D status, and to specifically estimate the effect of vitamin D in children who are vitamin D deficient. This study has been designed to adhere to the Preferred Reporting Items for Systematic Review and Meta-Analyses of IPD statement. We will include randomised placebo-controlled trials of vitamin D supplementation reporting bone density outcomes at least 6 months after the study commenced in children and adolescents (aged <20 years) without coexistent medical conditions or treatments causing osteoporosis. We will update the search of the original review to cover the period 2009-2017, using the same methods as the original review. Fully anonymised data on all randomised patients will be requested. Outcomes will be femoral neck, total hip, lumbar spine and proximal and distal forearm bone mineral density, and total body bone mineral content. A two-stage IPD meta-analysis will be used to examine the effect of baseline serum 25-hydroxyvitamin D (25(OH)D) on treatment effect for each bone density outcome. Restricted maximum likelihood will be used to estimate the random-effects meta-analysis models, with 95% CI for summary effects. Heterogeneity will be assessed by I 2 and potential publication bias (small-study effects) and availability bias by funnel plots, Egger's test and Peter's test. Ethics approval will not be required as the data are to be used for the primary purpose for which they were collected and all original individual studies had ethics approval. Results of the IPD meta-analysis will be submitted for publication in a peer-reviewed journal. CRD42017068772. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Effect of a new physiotherapy concept on bone mineral density, muscle force and gross motor function in children with bilateral cerebral palsy.

PubMed

Stark, C; Nikopoulou-Smyrni, P; Stabrey, A; Semler, O; Schoenau, E

2010-06-01

The purpose of this study was to determine the effect of a new physiotherapy concept on bone density, muscle force and motor function in bilateral spastic cerebral palsy children. In a retrospective data analysis 78 children were analysed. The concept included whole body vibration, physiotherapy, resistance training and treadmill training. The concept is structured in two in-patient stays and two periods of three months home-based vibration training. Outcome measures were dual-energy x-ray absorption (DXA), Leonardo Tilt Table and a modified Gross Motor Function Measure before and after six months of training. Percent changes were highly significant for bone mineral density, -content, muscle mass and significant for angle of verticalisation, muscle force and modified Gross Motor Function Measure after six months training. The new physiotherapy concept had a significant effect on bone mineral density, muscle force and gross motor function in bilateral spastic cerebral palsy children. This implicates an amelioration in all International Classification of Functioning, Disability and Health levels. The study serves as a basis for future research on evidence based paediatric physiotherapy taking into account developmental implications.

A detailed study of ice nucleation by feldspar minerals

NASA Astrophysics Data System (ADS)

Whale, T. F.; Murray, B. J.; Wilson, T. W.; Carpenter, M. A.; Harrison, A.; Holden, M. A.; Vergara Temprado, J.; Morris, J.; O'Sullivan, D.

2015-12-01

Immersion mode heterogeneous ice nucleation plays a crucial role in controlling the composition of mixed phase clouds, which contain both supercooled liquid water and ice particles. The amount of ice in mixed phase clouds can affect cloud particle size, lifetime and extent and so affects radiative properties and precipitation. Feldspar minerals are probably the most important minerals for ice nucleation in mixed phase clouds because they nucleate ice more efficiently than other components of atmospheric mineral dust (Atkinson et al. 2013). The feldspar class of minerals is complex, containing numerous chemical compositions, several crystal polymorphs and wide variations in microscopic structure. Here we present the results of a study into ice nucleation by a wide range of different feldspars. We found that, in general, alkali feldspars nucleate ice more efficiently than plagioclase feldspars. However, we also found that particular alkali feldspars nucleate ice relatively inefficiently, suggesting that chemical composition is not the only important factor that dictates the ice nucleation efficiency of feldspar minerals. Ice nucleation by feldspar is described well by the singular model and is probably site specific in nature. The alkali feldspars that do not nucleate ice efficiently possess relatively homogenous structure on the micrometre scale suggesting that the important sites for nucleation are related to surface topography. Ice nucleation active site densities for the majority of tested alkali feldspars are similar to those found by Atkinson et al (2013), meaning that the validity of global aerosol modelling conducted in that study is not affected. Additionally, we have found that ice nucleation by feldspars is strongly influenced, both positively and negatively, by the solute content of droplets. Most other nucleants we have tested are unaffected by solutes. This provides insight into the mechanism of ice nucleation by feldspars and could be of importance when modelling ice nucleation in mixed phase clouds. Atkinson, J. D., Murray, B. J., Woodhouse, M. T., Carslaw, K. S., Whale, T. F., Baustian, K. J., Dobbie, S., O'Sullivan, D., and Malkin, T. L.: The importance of feldspar for ice nucleation by mineral dust in mixed-phase clouds, Nature, 10.1038/nature12278, (2013).

Gene-dietary fat interaction, bone mineral density and bone speed of sound in Children: a twin study in China

PubMed Central

Huang, Tao; Liu, Huijuan; Zhao, Wei; Li, Ji; Wang, Youfa

2015-01-01

Scope Dietary fat correlates with bone mineral density (BMD). We tested the association between fat intake and BMD, and tested if fat intake modified the degree of genetic influence on BMD and bone speed of sound (SOS). Methods and results We included 622 twins aged 7–15 y from South China. Data on anthropometry, dietary intake, BMD, and SOS were collected. Quantitative genetic analyses of structural equation models were fit using the Mx statistical package. The within-pair intra-class correlations (ICC) for BMD in DZ twins were nearly half of that for MZ twins (ICC=0.39 vs 0.70). The heritability of BMD and SOS were 71% and 79%. Phenotypic correlation between fat intake and SOS was significant (r=−0.19, p=0.04). SOS was negatively correlated with fat intake in boys (r=−0.11, p=0.05), but not in girls. Full Cholesky decomposition models showed SOS has a strong genetic correlation with fat intake (rA =−0.88, 95% CI=−0.94, 0.01); the environmental correlation between fat intake and SOS was weak (rE =−0.04, 95% CI=−0.20, 0.13). Fat intake modified the additive genetic effects on BMD. Conclusion Genetic factors explained 71% and 79% of individual variance in BMD and SOS, respectively. Low fat intake counteracts genetic predisposition to low BMD. PMID:25546604

Effect of once-yearly zoledronic acid on the spine and hip as measured by quantitative computed tomography: results of the HORIZON Pivotal Fracture Trial

PubMed Central

Lang, T.; Boonen, S.; Cummings, S.; Delmas, P. D.; Cauley, J. A.; Horowitz, Z.; Kerzberg, E.; Bianchi, G.; Kendler, D.; Leung, P.; Man, Z.; Mesenbrink, P.; Eriksen, E. F.; Black, D. M.

2016-01-01

Summary Changes in bone mineral density and bone strength following treatment with zoledronic acid (ZOL) were measured by quantitative computed analysis (QCT) or dual-energy X-ray absorptiometry (DXA). ZOL treatment increased spine and hip BMD vs placebo, assessed by QCT and DXA. Changes in trabecular bone resulted in increased bone strength. Introduction To investigate bone mineral density (BMD) changes in trabecular and cortical bone, estimated by quantitative computed analysis (QCT) or dual-energy X-ray absorptiometry (DXA), and whether zoledronic acid 5 mg (ZOL) affects bone strength. Methods In 233 women from a randomized, controlled trial of once-yearly ZOL, lumbar spine, total hip, femoral neck, and trochanter were assessed by DXA and QCT (baseline, Month 36). Mean percentage changes from baseline and between-treatment differences (ZOL vs placebo, t-test) were evaluated. Results Mean between-treatment differences for lumbar spine BMD were significant by DXA (7.0%, p<0.01) and QCT (5.7%, p<0.0001). Between-treatment differences were significant for trabecular spine (p=0.0017) [non-parametric test], trabecular trochanter (10.7%, p<0.0001), total hip (10.8%, p<0.0001), and compressive strength indices at femoral neck (8.6%, p=0.0001), and trochanter (14.1%, p<0.0001). Conclusions Once-yearly ZOL increased hip and spine BMD vs placebo, assessed by QCT vs DXA. Changes in trabecular bone resulted in increased indices of compressive strength. PMID:19802508

[Prevalence of low bone mineral density in postmenopausal breast cancer survivors].

PubMed

Poloni, Priscila Ferreira; Omodei, Michelle Sako; Nahas-Neto, Jorge; Uemura, Gilberto; Véspoli, Heloisa De Luca; Nahas, Eliana Aguiar Petri

2015-01-01

To evaluate the prevalence of low bone mineral density (BMD) in postmenopausal breast cancer survivors. In this cross-sectional study, 115 breast cancer survivors, seeking healthcare at a University Hospital in Brazil, were evaluated. Eligibility criteria included women with amenorrhea ≥ 12 months and age ≥ 45 years, treated for breast cancer and metastasis-free for at least five years. BMD was measured by DEXA at the lumbar spine (L1-L4) and femoral neck. Low BMD was considered when total-spine and/or femoral-neck T-score values were <-1.0 Delphi Score (DP) (osteopenia and osteoporosis). The risk factors for low BMD were assessed by interview. Data were analyzed statistically by the χ(2) test and Fisher's exact test. The mean age of breast cancer survivors was 61.6 ± 10.1 years and time since menopause was 14.2 ± 5.6 years, with a mean follow-up of 10.1 ± 3.9 years. Considering spine and femoral neck, 60% of breast cancer survivors had low BMD. By evaluating the risk factors for low BMD, a significant difference was found in the percent distribution for age (higher % of women >50 years with low BMD), personal history of previous fracture (11.6% with low BMD versus 0% with normal BMD) and BMI. A higher frequency of obesity was observed among women with normal BMD (63%) compared to those with low BMD (26.1%) (p<0.05). Postmenopausal breast cancer survivors had a high prevalence of osteopenia and osteoporosis.

Effect of microdose transdermal 17beta-estradiol compared with raloxifene in the prevention of bone loss in healthy postmenopausal women: a 2-year, randomized, double-blind trial.

PubMed

Schaefers, Matthias; Muysers, Christoph; Alexandersen, Peter; Christiansen, Claus

2009-01-01

Declining estrogen levels after menopause result in bone loss and increased fracture risk. This study investigated whether transdermal microdose 17beta-estradiol (E2) has efficacy and safety comparable to those of raloxifene, a selective estrogen-receptor modulator approved for the prevention and treatment of postmenopausal osteoporosis. This study involved a multicenter, randomized, double-blind, active-controlled, noninferiority trial in 500 osteopenic postmenopausal women comparing transdermal microdose E2 (0.014 mg/d) versus oral raloxifene (60 mg/d), administered for 2 years. Percent change from baseline in bone mineral density at the lumbar spine was measured after 2 years of treatment. Secondary endpoints included proportion of women with no loss of bone mineral density in lumbar spine, change in bone mineral density at hip, biochemical markers of bone turnover, and safety parameters. In the per protocol set, lumbar spine bone mineral density increased by 2.4% (95% CI, 1.9-2.9) with microdose E2 versus 3.0% (95% CI, 2.5-3.5) with raloxifene after 2 years; 77.3% of E2 recipients and 80.5% of those taking raloxifene had no bone loss in the lumbar spine. Both treatments were well tolerated. Most women (99% in the E2 group and 100% in the raloxifene group) showed no histological evidence of endometrial stimulation after 2 years. Mean dense area in breast mammograms was 19.8% in the E2 group versus 19.0% in the raloxifene group after 2 years. Transdermal microdose E2 was similarly effective as raloxifene in preventing bone loss at the lumbar spine. Both treatments were well tolerated, with no clinically significant effect on endometrium or breast density.

Polymorphisms in Genes Involved in the NF-κB Signalling Pathway Are Associated with Bone Mineral Density, Geometry and Turnover in Men

PubMed Central

Roshandel, Delnaz; Thomson, Wendy; Pye, Stephen R.; Boonen, Steven; Borghs, Herman; Vanderschueren, Dirk; Huhtaniemi, Ilpo T.; Adams, Judith E.; Ward, Kate A.; Bartfai, Gyorgy; Casanueva, Felipe F.; Finn, Joseph D.; Forti, Gianni; Giwercman, Aleksander; Han, Thang S.; Kula, Krzysztof; Lean, Michael E.; Pendleton, Neil; Punab, Margus; Wu, Frederick C.

2011-01-01

Introduction In this study, we aimed to investigate the association between single nucleotide polymorphisms (SNPs) within two genes involved in the NF-κB cascade (GPR177 and MAP3K14) and bone mineral density (BMD) assessed at different skeletal sites, radial geometric parameters and bone turnover. Methods Ten GPR177 SNPs previously associated with BMD with genome-wide significance and twelve tag SNPs (r2≥0.8) within MAP3K14 (±10 kb) were genotyped in 2359 men aged 40–79 years recruited from 8 centres for participation in the European Male Aging Study (EMAS). Measurement of bone turnover markers (PINP and CTX-I) in the serum and quantitative ultrasound (QUS) at the calcaneus were performed in all centres. Dual energy X-ray absorptiometry (DXA), at the lumbar spine and hip, and peripheral quantitative computed tomography (pQCT), at the distal and midshaft radius, were performed in a subsample (2 centres). Linear regression was used to test for association between the SNPs and bone measures under an additive genetic model adjusting for study centre. Results We validated the associations between SNPs in GPR177 and BMDa previously reported and also observed evidence of pleiotrophic effects on density and geometry. Rs2772300 in GPR177 was associated with increased total hip and LS BMDa, increased total and cortical vBMD at the radius and increased cortical area, thickness and stress strain index. We also found evidence of association with BMDa, vBMD, geometric parameters and CTX-I for SNPs in MAP3K14. None of the GPR177 and MAP3K14 SNPs were associated with calcaneal estimated BMD measured by QUS. Conclusion Our findings suggest that SNPs in GPR177 and MAP3K14 involved in the NF-κB signalling pathway influence bone mineral density, geometry and turnover in a population-based cohort of middle aged and elderly men. This adds to the understanding of the role of genetic variation in this pathway in determining bone health. PMID:22132199

X-ray crystallographic data for minerals

USGS Publications Warehouse

Robie, Richard A.; Bethke, Philip M.; Toulmin, M.S.; Edwards, Jerry L.

1963-01-01

X-ray crystallographic data are of particular importance to the mineralogist. Beyond the considerations of structural chemistry they provide. one of the most accurate methods for phase and/or compositional determination and for obtaining _the molar volumes and densities of minerals {Robie and Bethke, 1962).

Growth-Associated Changes in the Periodontal Bone and Molar Teeth of Male Rats

PubMed Central

García, María F; Moreno, Hilda; Rigalli, Alfredo; Puche, Rodolfo C

2009-01-01

Here we report quantitative data associating periodontal bone variables of young conventional rats with the growth process. The hemimandibles of male rats (IIM/Fm stock, 2 to 15 wk of age.) were excised and submitted to conventional morphologic, radiologic, and histologic evaluation. The length, area, or X-ray absorbance of various regions or structures was measured on digital images of radiographs by using an image-analysis program. The sum of periodontal bone areas undergoing resorption (interproximal + intraradicular) increased until 9 or 10 wk of age and decreased thereafter. Mineral accretion rates and mineral density asymptotes were not significantly different among molars. The mineral density of resorption areas in alveolar bone fitted sinusoidal kinetics, indicative of the ‘instability’ of the tissue due to its high metabolic activity. Mineral accretion rates and mineral density asymptotes were not significantly different among molars. The proportion of root length within alveolar bone exhibited a biphasic curve (minimum at 5 wk of age), due to differences in the growth rates of variables involved in its calculation (distance between the cementoenamel junction to the apex and height of the resorption areas). The distance between the cementoenamel junction and alveolar bone crest over time fitted a sigmoidal function with a point of inflection that did not differ significantly from that of body or mandible dry weight. In summary, the growth process appears to affect periodontal bone support and the distance between the cementoenamel junction and alveolar bone crest in male rats. PMID:19807966

Aliphatic and aromatic plant biopolymer dynamics in soil particles isolated from sequential density fractionation

NASA Astrophysics Data System (ADS)

Caldwell, B.; Filley, T.; Sollins, P.; Lajtha, K.; Swanston, C.; Kleber, M.; Kramer, M.

2007-12-01

A recent multi-layer-based soil organic matter-mineral interaction mechanistic model to describe the nature of soil organic matter-mineral surface mechanism for soil organic matter stabilization predicts that proteinaceous and aliphatic materials establish the core of strong binding-interactions upon which other organic matter is layered. A key methodology providing data underpinning this hypothesis is sequential density fractionation where soil is partitioned into particles of increasing density with the assumption that a partial control on organic matter distribution through density series is the thickness of its layering. Four soils of varying mineralogy and texture were investigated for their biopolymer, isotopic, and mineralogical properties. Light fractions (<1.8 g/cm3), although dominanted by organic detritus, did not always contain the highest concentration of lignin and substituted fatty acids from cutin and suberin while heavier fractions, 1.8-2.6 g/cm3, exhibited a progressive decrease in concentration in plant derived biopolymers with density. Extractable lignin phenols exhibited a progressive oxidation state with density. The concentration of biopolymers roughly mirrored the C:N ratio of soil particles which dropped consistently with increasing particle density. Although, in all soils, both lignin phenols and SFA concentration generally decreased with increasing density the ratio SFA/lignin varied with density and depending upon the soil. All soils, except the oxisol, exhibited an increase in SFA with respect to lignin suggesting a selective stabilization of those material with respect to lignin. In the oxisol, which showed little variation in its hematite dominated mineralogy across density, SFA/lignin remained constant, potentially indicating a greater capacity to stabilize lignin in that system. Interestingly, the lignin oxidation state increased with density in the oxisol. Given the variation in soil character, the consistency in these trends it suggests a general phenomenon of progressive decay in plant derived material with thinness of mineral coating but an overall relative increase in aliphatic character-all consistent with the multi-layer model.

Degradation of N-nitrosodimethylamine (NDMA) and its precursor dimethylamine (DMA) in mineral micropores induced by microwave irradiation.

PubMed

He, Yuanzhen; Cheng, Hefa

2016-05-01

Removal of N-nitrosodimethylamine (NDMA) in drinking water treatment poses a significant technical challenge due to its small molecular size, high polarity and water solubility, and poor biodegradability. Degradation of NDMA and its precursor, dimethylamine (DMA), was investigated by adsorbing them from aqueous solution using porous mineral sorbents, followed by destruction under microwave irradiation. Among the mineral sorbents evaluated, dealuminated ZSM-5 exhibited the highest sorption capacities for NDMA and DMA, which decreased with the density of surface cations present in the micropores. In contrast, the degradation rate of the sorbed NDMA increased with the density of surface cations under microwave irradiation. Evolutions of the degradation products and C/N ratio indicate that the sorbed NDMA and DMA could be eventually mineralized under continuous microwave irradiation. The degradation rate was strongly correlated with the bulk temperature of ZSM-5 and microwave power, which is consistent with the mechanism of pyrolysis caused by formation of micro-scale "hot spots" within the mineral micropores under microwave irradiation. Compared to existing treatment options for NDMA removal, microporous mineral sorption coupled with microwave-induced degradation has the unique advantages of being able to simultaneously remove NDMA and DMA and cause their full mineralization, and thus could serve as a promising alternative method. Copyright © 2016 Elsevier Ltd. All rights reserved.

[Fundamental study on effect of high-mineral drinking water for osteogenesis in calciprivia ovariectomized rats].

PubMed

Ogata, Fumihiko; Nagai, Noriaki; Ito, Yoshimasa; Kawasaki, Naohito

2014-01-01

Since osteoporosis is a major public health problem in Japan, it is important to clarify the effect of high-mineral drinking water consumption on osteogenesis. Therefore, in this study, we investigated the relationship between high-mineral drinking water consumption and osteogenesis in ovariectomized rats that received a low-calcium diet and purified water (PW group) or a low-calcium diet and high-mineral drinking water (CR group). High-mineral drinking water affected the rats' body weight. After 3 months, the bone density of the CR group was higher than that of the PW group (p<0.05). Furthermore, the CR group showed a decrease in the amount of calcium in the bones after 3 months. These results suggest that high-mineral drinking water contributes to the maintenance of bone density and not to the amount of calcium in bone. On the other hand, serum alkaline phosphatase levels in the PW group at 3 months were higher than those in the CR group, which indicates that the blood concentration of calcium in the CR group was maintained. Moreover, the amount of magnesium in the bones and the blood concentration of magnesium in the CR group after 3 months were higher than the corresponding values in the PW group. These results suggest that consumption of high-mineral drinking water could be beneficial for osteogenesis (i.e., for maintaining bone quantity).

Bone mineral density and nutritional status in children with quadriplegic cerebral palsy.

PubMed

Alvarez Zaragoza, Citlalli; Vasquez Garibay, Edgar Manuel; García Contreras, Andrea A; Larrosa Haro, Alfredo; Romero Velarde, Enrique; Rea Rosas, Alejandro; Cabrales de Anda, José Luis; Vega Olea, Israel

2018-03-04

This study demonstrated the relationship of low bone mineral density (BMD) with the degree of motor impairment, method of feeding, anthropometric indicators, and malnutrition in children with quadriplegic cerebral palsy (CP). The control of these factors could optimize adequate bone mineralization, avoid the risk of osteoporosis, and would improve the quality of life. The purpose of the study is to explore the relationship between low BMD and nutritional status in children with quadriplegic CP. A cross-sectional analytical study included 59 participants aged 6 to 18 years with quadriplegic CP. Weight and height were obtained with alternative measurements, and weight/age, height/age, and BMI/age indexes were estimated. The BMD measurement obtained from the lumbar spine was expressed in grams per square centimeter and Z score (Z). Unpaired Student's t tests, chi-square tests, odds ratios, Pearson's correlations, and linear regressions were performed. The mean of BMD Z score was lower in adolescents than in school-aged children (p = 0.002). Patients with low BMD were at the most affected levels of the Gross Motor Function Classification System (GMFCS). Participants at level V of the GMFCS were more likely to have low BMD than levels III and IV [odds ratio (OR) = 5.8 (confidence interval [CI] 95% 1.4, 24.8), p = 0.010]. There was a higher probability of low BMD in tube-feeding patients [OR = 8.6 (CI 95% 1.0, 73.4), p = 0.023]. The probability of low BMD was higher in malnourished children with weight/age and BMI indices [OR = 11.4 (1.3, 94), p = 0.009] and [OR = 9.4 (CI 95% 1.1, 79.7), p = 0.017], respectively. There was a significant relationship between low BMD, degree of motor impairment, method of feeding, and malnutrition. Optimizing these factors could reduce the risk of osteopenia and osteoporosis and attain a significant improvement of quality of life in children with quadriplegic CP.

Site preparation effects on soil bulk density and pine seedling growth

Treesearch

John J. Stransky

1981-01-01

Soil bulk density was sampled the first and third growing seasons after site preparation and pine planting on three clearcut pine-hardwood forest sites in eastern Texas. Bulk density was measured 10 cm below the surface of mineral soil using a surface moisture-density probe. Plots that had been KG-bladed and chopped had significanlty higher bulk density than those that...

Evaluation of potential site for mineral processing plant

NASA Astrophysics Data System (ADS)

Izwan Ishak, Muhamad Noor; Sipaun, Susan Maria; Mustapha, Ismail; Fahmi Engku Chik, Engku Mohd; Abdullah, Nurliyana; Affandi Mahmood, Airwan

2018-01-01

Nuclear moisture-density gauge is a type of instrument for measuring density and moisture of the material in a relatively thin zone beneath a surface of the material by using low activity of neutron and gamma radiation source. Density and moisture content data of the compacted layers are needed to determine the degree of compaction of soils, aggregate, concrete, asphalt or other materials used in civil engineering works. A gamma radiation source is mounted inside gauge housing with the source rod vertically extended to various depth positions. Direct transmission gamma radiation technique is used to obtain the count reading for the number of photons emitted before it is converted into density reading by microprocessor. This paper presents the inspection technique and results for the measurement of soil moisture and density carried out at potential site for mineral processing plant, Malaysian Nuclear Agency. Primarily, the experiment was conducted to ensure the compaction of ground is suitable for the plant construction. From the calculation, the percentages of soil wet density compaction (%WD Compact) are within acceptable limits with respect to the standard compacted wet soil density measured in the laboratory.

Children who avoid drinking cow milk have low dietary calcium intakes and poor bone health.

PubMed

Black, Ruth E; Williams, Sheila M; Jones, Ianthe E; Goulding, Ailsa

2002-09-01

Information concerning the adequacy of bone mineralization in children who customarily avoid drinking cow milk is sparse. The objective was to evaluate dietary calcium intakes, anthropometric measures, and bone health in prepubertal children with a history of long-term milk avoidance. We recruited 50 milk avoiders (30 girls, 20 boys) aged 3-10 y by advertisement. We measured current dietary calcium intakes with a food-frequency questionnaire and body composition and bone mineral density with dual-energy X-ray absorptiometry and compared the results with those of 200 milk-drinking control children. The reasons for milk avoidance were intolerance (40%), bad taste (42%), and lifestyle choice (18%). Dietary calcium intakes were low (443 +/- 230 mg Ca/d), and few children consumed substitute calcium-rich drinks or mineral supplements. Although 9 children (18%) were obese, the milk avoiders were shorter (P < 0.01), had smaller skeletons (P < 0.01), had a lower total-body bone mineral content (P < 0.01), and had lower z scores (P < 0.05) for areal bone mineral density at the femoral neck, hip trochanter, lumbar spine, ultradistal radius, and 33% radius than did control children of the same age and sex from the same community. The z scores for volumetric (size-adjusted) bone mineral density (g/cm(3)) were -0.72 +/- 1.17 for the lumbar spine and -0.72 +/- 1.35 for the 33% radius (P < 0.001). Twelve children (24%) had previously broken bones. In growing children, long-term avoidance of cow milk is associated with small stature and poor bone health. This is a major concern that warrants further study.

Mineral content of complementary foods.

PubMed

Jani, Rati; Udipi, S A; Ghugre, P S

2009-01-01

To document mineral contents iron, zinc, calcium, energy contents and nutrient densities in complementary foods commonly given to young urban slum children. Information on dietary intake was collected from 892 mothers of children aged 13-24 months, using 24 hour dietary recall and standardized measures. Three variations of 27 most commonly prepared recipes were analyzed and their energy (Kcal/g) and nutrient densities (mg/100 Kcal) were calculated. Considerable variations were observed in preparation of all items fed to the children. Cereal-based items predominated their diets with only small amount of vegetables/fruits. Fenugreek was the only leafy vegetable included, but was given to only 1-2% of children. Iron, calcium, zinc contents of staple complementary foods ranged from: 0.33 mg to 3.73 mg, 4 mg to 64 mg, and 0.35 mg to 2.99 mg/100 respectively. Recipes diluted with less water and containing vegetables, spices had higher mineral content. Minerals densities were higher for dals, fenugreek vegetable, khichdi and chapatti. Using the median amounts of the various recipes fed to children, intakes of all nutrients examined especially calcium and iron was low. There is an urgent need to educate mothers about consistency, dilution, quantity, frequency, method of preparation, inclusion of micronutrient-rich foods, energy-dense complementary foods and gender equality.

A Study of Oil Viscosity Mental Model

NASA Astrophysics Data System (ADS)

Albaiti; Liliasari; Sumarna, Omay; Abdulkadir Martoprawiro, Muhamad

2017-02-01

There is no study regarding on how to learn viscosity of the liquid (e.g. oil) by interconnecting macroscopic, sub-microscopic and symbolic levels. Therefore, the purpose of this research was to study the mental model of the oil viscosity. Intermolecular attractive force of oil constituent on the sub-microscopic level is depicted in the form of mental models. In this research, the viscosity data for some types of oil was measured by using Hoppler method. Viscosity of mineral oil SAE 20W-50, mineral oil SAE 15W-40 and synthetic oil SAE 10W-40 were 1.75, 1.31, and 1.03 Pa s, and the densities of these oils were 908.64, 885.04, and 877.02 kg/m3, respectively. The results showed that the greater density of the mineral oil that is assumed to be composed of linear chains of hydrocarbons, the longer the chain of hydrocarbon linear. Consequently, there are stronger the London force and greater the oil viscosity. The density and viscosity of synthetic oil are lower than that of both mineral oils. Synthetic oil structurally forms polymers with large branching. This structure affects a lower synthetic oil viscosity. This study contributes to construct a mental model of pre-service chemistry teachers.

Cartilage Degeneration, Subchondral Mineral and Meniscal Mineral Densities in Hartley and Strain 13 Guinea Pigs

PubMed Central

Sun, Yubo; Scannell, Brian P; Honeycutt, Patrick R; Mauerhan, David R; H, James Norton; Hanley Jr, Edward N

2015-01-01

Osteoarthritis is a joint disease involved in articular cartilage, subchondral bone, meniscus and synovial membrane. This study sought to examine cartilage degeneration, subchondral bone mineral density (BMD) and meniscal mineral density (MD) in male Hartley, female Hartley and female strain 13 guinea pigs to determine the association of cartilage degeneration with subchondral BMD and meniscal MD. Cartilage degeneration, subchondral BMD and meniscal MD in 12 months old guinea pigs were examined with histochemistry, X-ray densitometry and calcium analysis. We found that male Hartley guinea pigs had more severe cartilage degeneration, subchondral BMD and meniscal MD than female Hartley guinea pigs, but not female strain 13 guinea pigs. Female strain 13 guinea pigs had more severe cartilage degeneration and higher subchondral BMD, but not meniscal MD, than female Hartley guinea pigs. These findings indicate that higher subchondral BMD, not meniscal MD, is associated with more severe cartilage degeneration in the guinea pigs and suggest that abnormal subchondral BMD may be a therapeutic target for OA treatment. These findings also indicate that the pathogenesis of OA in the male guinea pigs and female guinea pigs are different. Female strain 13 guinea pig may be used to study female gender-specific pathogenesis of OA. PMID:26401159

Bone mineral density in children with idiopathic nephrotic syndrome.

PubMed

El-Mashad, Ghada Mohamed; El-Hawy, Mahmoud Ahmed; El-Hefnawy, Sally Mohamed; Mohamed, Sanaa Mansour

To assess bone mineral density (BMD) in children with idiopathic nephrotic syndrome (NS) and normal glomerular filtration rate (GFR). Cross-sectional case-control study carried out on 50 children: 25 cases of NS (16 steroid-sensitive [SSNS] and nine steroid-resistant [SRNS] under follow up in the pediatric nephrology unit of Menoufia University Hospital, which is tertiary care center, were compared to 25 healthy controls with matched age and sex. All of the participants were subjected to complete history taking, thorough clinical examination, laboratory investigations (serum creatinine, blood urea nitrogen [BUN], phosphorus [P], total and ionized calcium [Ca], parathyroid hormone [PTH], and alkaline phosphatase [ALP]). Bone mineral density was measured at the lumbar spinal region (L2-L4) in patients group using dual-energy X-ray absorptiometry (DXA). Total and ionized Ca were significantly lower while, serum P, ALP, and PTH were higher in SSNS and SRNS cases than the controls. Osteopenia was documented by DXA scan in 11 patients (44%) and osteoporosis in two patients (8%). Fracture risk was mild in six (24%), moderate in two (8%), and marked in three (12%) of patients. Bone mineralization was negatively affected by steroid treatment in children with NS. Copyright © 2016 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

Assessment of bone turnover markers and bone mineral density in normal short boys.

PubMed

Gayretli Aydin, Zeynep Gökçe; Bideci, Aysun; Emeksiz, Hamdi C; Çelik, Nurullah; Döğer, Esra; Bukan, Neslihan; Yildiz, Ummügülsüm; Camurdan, Orhun M; Cinaz, Peyami

2015-11-01

To investigate whether there is a change in bone turnover-related biochemical markers and bone mineral density of children with constitutional delay of growth and puberty (CDGP) in the prepubertal period. We measured serum calcium, phosphorus, alkaline phosphatase, parathormone, 25-OH vitamin D, osteocalcin, osteoprotogerin and urinary deoxypyridinoline levels (D-pyd), and bone mineral density (BMD) in 31 prepubertal boys with CDGP. These children were compared with 22 prepubertal boys with familial short stature (FSS) and 27 normal prepubertal boys. Urinary D-pyd was significantly high in CDGP group as compared to control group (p=0.010). Volumetric BMD did not significantly differ between CDGP, FSS, and control groups (p=0.450). Volumetric BMD and urinary D-pyd levels of FSS and control groups were similar. Mean or median levels of calcium, phosphorus, alkaline phosphatase, parathormone, and osteoprotegerin did not significantly differ between CDGP, FSS, and control groups. Our data suggest that prepubertal boys with CDPG have normal bone turnover. However, their significantly higher urinary D-pyd levels relative to those of FSS and control groups might be an indicator of later development of osteoporosis. Therefore, long-term follow-up studies monitoring bone mineral status of prepubertal boys with CDPG from prepuberty to adulthood are needed to better understand bone metabolism of these patients.

Effects of controlled whole-body vibration training in improving fall risk factors among individuals with multiple sclerosis: A pilot study.

PubMed

Yang, Feng; Finlayson, Marcia; Bethoux, Francois; Su, Xiaogang; Dillon, Loretta; Maldonado, Hector M

2018-03-01

The purpose of this study was to systematically examine the effect of an 8-week controlled whole-body vibration training on improving fall risk factors and the bone mineral density among people with multiple sclerosis (PwMS). This study adopted a single group pre-test-post-test design. Twenty-five PwMS (50.3 years SD 14.1) received vibration training on a side-alternating vibration platform. Each training session was repeated three times every week for 8 weeks. Prior to and following the 8-week training course, a battery of fall risk factors were evaluated: the body balance, functional mobility, muscle strength, range of motion, and fear of falling. Bone density at both calcanei was also assessed. Twenty-two participants completed the study. Compared with pre-test, almost all fall risk factors and the bone density measurement were significantly improved at post-test, with moderate to large effect sizes varying between 0.571 and 1.007. The 8-week vibration training was well accepted by PwMS and improved their fall risk factors. The important findings of this study were that vibration training may increase the range of motion of ankle joints on the sagittal plane, lower the fear of falling, and improve bone density. IMPLICATIONS FOR REHABILITATION An 8-week vibration training course could be well-accepted by people with multiple sclerosis (MS). Vibration training improves the risk factors of falls in people living with MS. Vibration training could be a promising rehabilitation intervention in individuals with MS.

Hand grip strength and maximum peak expiratory flow: determinants of bone mineral density of adolescent students.

PubMed

Cossio-Bolaños, Marco; Lee-Andruske, Cynthia; de Arruda, Miguel; Luarte-Rocha, Cristian; Almonacid-Fierro, Alejandro; Gómez-Campos, Rossana

2018-03-02

Maintaining and building healthy bones during the lifetime requires a complicated interaction between a number of physiological and lifestyle factors. Our goal of this study was to analyze the association between hand grip strength and the maximum peak expiratory flow with bone mineral density and content in adolescent students. The research team studied 1427 adolescent students of both sexes (750 males and 677 females) between the ages of 11.0 and 18.9 years in the Maule Region of Talca (Chile). Weight, standing height, sitting height, hand grip strength (HGS), and maximum peak expiratory flow (PEF) were measured. Furthermore, bone mineral density (BMD) and total body bone mineral content (BMC) were determined by using the Dual-Energy X-Ray Absorptiometry (DXA). Hand grip strength and PEF were categorized in tertiles (lowest, middle, and highest). Linear regression was performed in steps to analyze the relationship between the variables. Differences between categories were determined through ANOVA. In males, the hand grip strength explained 18-19% of the BMD and 20-23% of the BMC. For the females, the percentage of variation occurred between 12 and 13% of the BMD and 17-18% of the BMC. The variation of PEF for the males was observed as 33% of the BMD and 36% of the BMC. For the females, both the BMD and BMC showed a variation of 19%. The HGS and PEF were divided into three categories (lowest, middle, and highest). In both cases, significant differences occurred in bone density health between the three categories. In conclusion, the HGS and the PEF related positively to the bone density health of both sexes of adolescent students. The adolescents with poor values for hand grip strength and expiratory flow showed reduced values of BMD and BMC for the total body. Furthermore, the PEF had a greater influence on bone density health with respect to the HGS of the adolescents of both sexes.

Relation between obesity and bone mineral density and vertebral fractures in Korean postmenopausal women.

PubMed

Kim, Kyong-Chol; Shin, Dong-Hyuk; Lee, Sei-Young; Im, Jee-Aee; Lee, Duk-Chul

2010-11-01

The traditional belief that obesity is protective against osteoporosis has been questioned. Recent epidemiologic studies show that body fat itself may be a risk factor for osteoporosis and bone fractures. Accumulating evidence suggests that metabolic syndrome and the individual components of metabolic syndrome such as hypertension, increased triglycerides, and reduced high-density lipoprotein cholesterol are also risk factors for low bone mineral density. Using a cross sectional study design, we evaluated the associations between obesity or metabolic syndrome and bone mineral density (BMD) or vertebral fracture. A total of 907 postmenopausal healthy female subjects, aged 60-79 years, were recruited from woman hospitals in Seoul, South Korea. BMD, vetebral fracture, bone markers, and body composition including body weight, body mass index (BMI), percentage body fat, and waist circumference were measured. After adjusting for age, smoking status, alcohol consumption, total calcium intake, and total energy intake, waist circumference was negatively related to BMD of all sites (lumbar BMD p = 0.037, all sites of femur BMD p < 0.001) whereas body weight was still positively related to BMD of all sites (p < 0.001). Percentage body fat and waist circumference were much higher in the fracture group than the non-fracture group (p = 0.0383, 0.082 respectively). Serum glucose levels were positively correlated to lumbar BMD (p = 0.016), femoral neck BMD (p = 0.0335), and femoral trochanter BMD (p = 0.0082). Serum high density lipoprotein cholesterol (HDLC) was positively related to femoral trochanter BMD (p = 0.0366) and was lower in the control group than the fracture group (p = 0.011). In contrast to the effect favorable body weight on bone mineral density, high percentage body fat and waist circumference are related to low BMD and a vertebral fracture. Some components of metabolic syndrome were related to BMD and a vertebral fracture.

Mineral resource of the month: vermiculite

USGS Publications Warehouse

Potter, M.J.

2008-01-01

Vermiculite, a hydrated magnesium-aluminum-iron silicate mineral, has a range of uses that take advantage of its fire resistance, good insulating properties, high liquid absorption capacity, inertness and low density. Most applications for vermiculite use an exfoliated (heat-expanded) form of the mineral. In general, coarser grades of vermiculite are used as loose fill insulation and in horticulture. Finer grades are used in wallboard and plasters and for animal feeds and fertilizers.

Effects of whole-body vibration training on physical function, bone and muscle mass in adolescents and young adults with cerebral palsy

PubMed Central

Gusso, Silmara; Munns, Craig F; Colle, Patrícia; Derraik, José G B; Biggs, Janene B; Cutfield, Wayne S; Hofman, Paul L

2016-01-01

We performed a clinical trial on the effects of whole-body vibration training (WBVT) on muscle function and bone health of adolescents and young adults with cerebral palsy. Forty participants (11.3–20.8 years) with mild to moderate cerebral palsy (GMFCS II–III) underwent 20-week WBVT on a vibration plate for 9 minutes/day 4 times/week at 20 Hz (without controls). Assessments included 6-minute walk test, whole-body DXA, lower leg pQCT scans, and muscle function (force plate). Twenty weeks of WBVT were associated with increased lean mass in the total body (+770 g; p = 0.0003), trunk (+410 g; p = 0.004), and lower limbs (+240 g; p = 0.012). Bone mineral content increased in total body (+48 g; p = 0.0001), lumbar spine (+2.7 g; p = 0.0003), and lower limbs (+13 g; p < 0.0001). Similarly, bone mineral density increased in total body (+0.008 g/cm2; p = 0.013), lumbar spine (+0.014 g/cm2; p = 0.003), and lower limbs (+0.023 g/cm2; p < 0.0001). Participants reduced the time taken to perform the chair test, and improved the distance walked in the 6-minute walk test by 11% and 35% for those with GMFCS II and III, respectively. WBVT was associated with increases in muscle mass and bone mass and density, and improved mobility of adolescents and young adults with cerebral palsy. PMID:26936535

Effects of spaceflight and Insulin-like Growth Factor-1 on rat bone properties

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bateman, T.A.; Ayers, R.A.; Spetzler, M.L.

Spaceflight induces bone degradation which is analogous to an accelerated onset of osteoporosis in humans (Tilton {ital et al.}, 1980). In rats, decreased bone formation is indicative of reduced osteoblast activity (Morey and Baylink, 1978). Chiron Corporation (Emeryville, CA) is interested in using the microgravity environment of low-Earth-orbit to test its therapeutic drug, Insulin-like Growth Factor-1 (IGF-1). This pharmaceutic is known to promote osteoblast activity (Schmid {ital et al.}, 1984) and therefore may encourage bone growth in rats. Chiron sponsored the Immune.3 payload on STS-73 (May 19{endash}29, 1996) through its Center for Space Commercialization (CSC) partner BioServe Space Technologies (Universitymore » of Colorado and Kansas State University) to investigate the effects of IGF-1 on mitigating the skeletal degradation that affects rats and humans during spaceflight. Twelve rats were flown for 10 days using two Animal Enclosure Modules (AEMs) provided by NASA Ames Research Center. Of the twelve, six received 1.4 mg/day of IGF-1; the other six saline. Sixteen vivarium ground controls received the same treatment on a one day delay. Rat femora and tibiae were examined for bone mineral density via DXA scan. Femora and humeri were measured for physical and compositional properties, as well as mechanically tested in three point flexure. Quantitative histomorphometric examination of tibiae, humeri, fibulae, ribs and cranial bone; and microhardness testing on tibiae and humeri are currently in progress. Flight humeri and vivarium femora were significantly larger than their counterparts; however, significant differences in mechanical properties and mineral density were not concurrent to these mass changes. {copyright} {ital 1997 American Institute of Physics.}« less

The Relationship of Bone Mineral Density in Men with Chronic Obstructive Pulmonary Disease Classified According to the Global Initiative for Chronic Obstructive Lung Disease (GOLD) Combined Chronic Obstructive Pulmonary Disease (COPD) Assessment System.

PubMed

Sakurai-Iesato, Yoriko; Kawata, Naoko; Tada, Yuji; Iesato, Ken; Matsuura, Yukiko; Yahaba, Misuzu; Suzuki, Toshio; Ikari, Jun; Yanagawa, Noriyuki; Kasahara, Yasunori; West, James; Tatsumi, Koichiro

2017-01-01

Objective Osteoporosis, which is now recognized as a major comorbidity of chronic obstructive pulmonary disease (COPD), must be diagnosed by appropriate methods. The aims of this study were to clarify the relationships between bone mineral density (BMD) and COPD-related clinical variables and to explore the association of BMD with the updated Global Initiative for Chronic Obstructive Lung Disease (GOLD) classification in men. Methods We enrolled 50 Japanese men with clinically stable COPD who underwent dual-energy X-ray absorptiometry (DEXA), pulmonary function testing, and computerized tomography (CT) and who had completed a questionnaire (COPD assessment test [CAT]). We determined the association between the T-score and other tested parameters and compared the BMD of patients in each GOLD category. Results Twenty-three of the 50 patients (46.0%) were diagnosed with osteopenia, and 7 (14.0%) were diagnosed with osteoporosis. The BMD findings were significantly correlated with the CAT score, forced expiratory volume in 1 second percentage predicted (FEV 1 % predicted), low attenuation volume percentage (LAV%), and percentage of cross-sectional area of small pulmonary vessels (%CSA) on CT images. Notably, the median T-score of the GOLD category D participants was significantly lower than that of the participants in each of the other categories (A [-0.98], B [-1.06], C [-1.05], and D [-2.19], p<0.05). Conclusion Reduced BMD was associated with airflow limitation, extent of radiographic findings, and a poor quality of life (QOL) in patients with COPD. The BMD of GOLD category D patients was the lowest of all of the patients evaluated, and category D patients may benefit from active intervention for osteoporosis.

The Relationship of Bone Mineral Density in Men with Chronic Obstructive Pulmonary Disease Classified According to the Global Initiative for Chronic Obstructive Lung Disease (GOLD) Combined Chronic Obstructive Pulmonary Disease (COPD) Assessment System

PubMed Central

Sakurai-Iesato, Yoriko; Kawata, Naoko; Tada, Yuji; Iesato, Ken; Matsuura, Yukiko; Yahaba, Misuzu; Suzuki, Toshio; Ikari, Jun; Yanagawa, Noriyuki; Kasahara, Yasunori; West, James; Tatsumi, Koichiro

2017-01-01

Objective Osteoporosis, which is now recognized as a major comorbidity of chronic obstructive pulmonary disease (COPD), must be diagnosed by appropriate methods. The aims of this study were to clarify the relationships between bone mineral density (BMD) and COPD-related clinical variables and to explore the association of BMD with the updated Global Initiative for Chronic Obstructive Lung Disease (GOLD) classification in men. Methods We enrolled 50 Japanese men with clinically stable COPD who underwent dual-energy X-ray absorptiometry (DEXA), pulmonary function testing, and computerized tomography (CT) and who had completed a questionnaire (COPD assessment test [CAT]). We determined the association between the T-score and other tested parameters and compared the BMD of patients in each GOLD category. Results Twenty-three of the 50 patients (46.0%) were diagnosed with osteopenia, and 7 (14.0%) were diagnosed with osteoporosis. The BMD findings were significantly correlated with the CAT score, forced expiratory volume in 1 second percentage predicted (FEV1% predicted), low attenuation volume percentage (LAV%), and percentage of cross-sectional area of small pulmonary vessels (%CSA) on CT images. Notably, the median T-score of the GOLD category D participants was significantly lower than that of the participants in each of the other categories (A [-0.98], B [-1.06], C [-1.05], and D [-2.19], p<0.05). Conclusion Reduced BMD was associated with airflow limitation, extent of radiographic findings, and a poor quality of life (QOL) in patients with COPD. The BMD of GOLD category D patients was the lowest of all of the patients evaluated, and category D patients may benefit from active intervention for osteoporosis. PMID:28717072

Physical activity and 5-year changes in physical performance tests and bone mineral density in postmenopausal women: the Yokogoshi Study.

PubMed

Kitamura, Kaori; Nakamura, Kazutoshi; Kobayashi, Ryosaku; Oshiki, Rieko; Saito, Toshiko; Oyama, Mari; Takahashi, Shunsuke; Nishiwaki, Tomoko; Iwasaki, Masanori; Yoshihara, Akihiro

2011-09-01

The effect of physical activity on musculoskeletal health in older adults is not completely understood. The aim of this study was to determine the relationship between physical activity and 5-year changes in physical performance tests and bone mineral density (BMD) in postmenopausal women. The design was a 5-year cohort study. Subjects were 507 women (55-74 years old) living in a rural community in Japan. Physical activity assessed included housework, farm work, and moderate leisure-time physical activity within the previous week. Measurements at baseline included handgrip strength, walking time (timed "Up & Go" test) and BMD of the femoral neck and vertebrae. Five-year changes in these measures (outcome variables) were compared among groups with different levels of physical activity by analysis of covariance. Women who did not do housework performed worse in changes in handgrip strength (difference=2.22 kg, P=0.0201) and worse in changes in the walking time (difference=0.54 s, P=0.0072) than those who did housework alone. Women who spent at least 9h per week (median=24) doing farm work performed better in changes in handgrip strength (difference=0.28 kg, P=0.0334), but worse in changes in the walking time (difference=0.66 s, P<0.0001) than those who did not do farm work. However, leisure-time activity was not associated with changes in any outcome variable, and none of the physical activities predicted BMD changes. Engaging in housework and farm work are determinants of physical function in postmenopausal women, which may help them maintain independence in daily living. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Silicon: A Review of Its Potential Role in the Prevention and Treatment of Postmenopausal Osteoporosis

PubMed Central

Price, Charles T.; Koval, Kenneth J.; Langford, Joshua R.

2013-01-01

Physicians are aware of the benefits of calcium and vitamin D supplementation. However, additional nutritional components may also be important for bone health. There is a growing body of the scientific literature which recognizes that silicon plays an essential role in bone formation and maintenance. Silicon improves bone matrix quality and facilitates bone mineralization. Increased intake of bioavailable silicon has been associated with increased bone mineral density. Silicon supplementation in animals and humans has been shown to increase bone mineral density and improve bone strength. Dietary sources of bioavailable silicon include whole grains, cereals, beer, and some vegetables such as green beans. Silicon in the form of silica, or silicon dioxide (SiO2), is a common food additive but has limited intestinal absorption. More attention to this important mineral by the academic community may lead to improved nutrition, dietary supplements, and better understanding of the role of silicon in the management of postmenopausal osteoporosis. PMID:23762049

Quantitative computed tomography-based predictions of vertebral strength in anterior bending.

PubMed

Buckley, Jenni M; Cheng, Liu; Loo, Kenneth; Slyfield, Craig; Xu, Zheng

2007-04-20

This study examined the ability of QCT-based structural assessment techniques to predict vertebral strength in anterior bending. The purpose of this study was to compare the abilities of QCT-based bone mineral density (BMD), mechanics of solids models (MOS), e.g., bending rigidity, and finite element analyses (FE) to predict the strength of isolated vertebral bodies under anterior bending boundary conditions. Although the relative performance of QCT-based structural measures is well established for uniform compression, the ability of these techniques to predict vertebral strength under nonuniform loading conditions has not yet been established. Thirty human thoracic vertebrae from 30 donors (T9-T10, 20 female, 10 male; 87 +/- 5 years of age) were QCT scanned and destructively tested in anterior bending using an industrial robot arm. The QCT scans were processed to generate specimen-specific FE models as well as trabecular bone mineral density (tBMD), integral bone mineral density (iBMD), and MOS measures, such as axial and bending rigidities. Vertebral strength in anterior bending was poorly to moderately predicted by QCT-based BMD and MOS measures (R2 = 0.14-0.22). QCT-based FE models were better strength predictors (R2 = 0.34-0.40); however, their predictive performance was not statistically different from MOS bending rigidity (P > 0.05). Our results suggest that the poor clinical performance of noninvasive structural measures may be due to their inability to predict vertebral strength under bending loads. While their performance was not statistically better than MOS bending rigidities, QCT-based FE models were moderate predictors of both compressive and bending loads at failure, suggesting that this technique has the potential for strength prediction under nonuniform loads. The current FE modeling strategy is insufficient, however, and significant modifications must be made to better mimic whole bone elastic and inelastic material behavior.

The efficiency of risedronate in reducing bone resorption after total hip arthroplasty: a meta-analysis of randomized control trials at a minimum of 6 months' follow-up.

PubMed

Yang, Liqing

2018-04-17

Recently risedronate is suggested to be effective for the prevention and treatment of for osteoporosis in total hip arthroplasty. This meta-analysis aimes to evaluate the efficacy of risedronate in reducing femoral periprosthetic bone mineral density loss in patients undergoing primary total hip arthroplasty. A systematic search was performed in Medline (1966-31 October 2017), PubMed (1966-31 October 2017), Embase (1980-31 October 2017), ScienceDirect (1985-31 October 2017) and the Cochrane Library. Only randomized controlled trial (RCT) were included. Fixed/random effect model was used according to the heterogeneity tested by I2 statistic. Meta-analysis was performed using Stata 11.0 software. The outcome measures included periprosthetic bone mineral density, length of stay and adverse effects. Four RCTs including 198 patients met the inclusion criteria. The present meta-analysis showed that there were significant differences between treatment groups in terms of periprosthetic bone mineral density in Gruen zones 1 (standard mean difference (SMD) = 0.758, 95% CI 0.469 to 1.047, P = 0.000), 2 (SMD = 0.814, 95% CI 0.523 to 1.106, P = 0.000), 3 (SMD = 0.340, 95% CI 0.059 to 0.622, P = 0.018), 6 (SMD = 2.400, 95% CI 2.029 to 2.771, P = 0.000), and 7 (SMD = 2.400, 95% CI 2.029 to 2.771, P = 0.000). Oral risedronate could significantly reduce periprosthetic bone resorption around an uncemented femoral stem (Gruen zones 1, 2, 3, 6, and 7) up to 6 months after THA. In addition, no severe adverse events were identified. Future trials of risedronate treatment after THA should focus on clinically relevant end points such as the risks of fracture and revision arthroplasty.

Measurement of Cohesion in Asteroid Regolith Materials

NASA Technical Reports Server (NTRS)

Kleinhenz, Julie E.; Gaier, James R.; Waters, Deborah L.; Harvey, Ralph; Zeszut, Zoe; Carreno, Brandon; Shober, Patrick

2017-01-01

A study has been initiated to examine cohesive forces in asteroid materials to contribute to a better understanding of low density bodies such as asteroids and Phobos, and assist in exploration missions involving interaction with their surface material. The test specimen used in this study was a lightly weathered CM2 meteorite which is spectroscopically similar to Type C (carbonaceous) asteroids, and thought to have representative surface chemistry. To account for sample heterogeneity, adhesion forces were measured between the CM2 sample and its five primary mineral phase components. These adhesive forces bound the range of cohesive force that can be expected for the bulk material. All materials were characterized using a variety of optical and spectroscopic methods. Adhesive forces on the order of 50 to 400 µN were measured using a torsion balance in an ultrahigh vacuum chamber. The mineral samples exhibited clearly different adhesive strengths in the following hierarchy: Serpentine > Siderite > Bronzite > Olivine ˜ Fe-Ni.

Development and application of screening tools for biodegradation in water-sediment systems and soil.

PubMed

Junker, Thomas; Coors, Anja; Schüürmann, Gerrit

2016-02-15

Two new screening-test systems for biodegradation in water-sediment systems (WSST; Water-Sediment Screening Tool) and soil (SST; Soil Screening Tool) were developed in analogy with the water-only test system OECD 301C (MITI-test). The test systems could be applied successfully to determine reproducible experimental mineralization rates and kinetics on the screening-test level for fifteen organic chemicals in water (MITI), water-sediment (WSST) and soil (SST). Substance-specific differences were observed for mineralization compared among the three test systems. Based on mineralization rate and mineralization half-life, the fifteen compounds could be grouped into four biodegradation categories: substances with high mineralization and a half-life <28 days in (1) all three test systems, (2) only in the MITI test and in the WSST, (3) only in the SST, and (4) none of the test systems. The observed differences between the MITI results and the WSST and SST biodegradation rates of the compounds do not reflect their (reversible) sorption into organic matter in terms of experimental K(oc) values and log D values for the relevant pH range. Regarding mineralization kinetics we recommend to determine the lag-phase, mineralization half-life and mineralization rate using a 5-parameter logistic regression for degradation curves with and without lag-phase. Experimental data obtained with the WSST and the SST could be verified by showing good agreement with biodegradation data from databases and literature for the majority of compounds tested. Thus, these new screening-tools for water-sediment and soil are considered suitable to determine sound and reliable quantitative mineralization data including mineralization kinetics in addition to the water-only ready biodegradability tests according to OECD 301. Copyright © 2015 Elsevier B.V. All rights reserved.

Cortical bone is more sensitive to alcohol dose effects than trabecular bone in the rat.

PubMed

Maurel, Delphine B; Boisseau, Nathalie; Benhamou, Claude-Laurent; Jaffré, Christelle

2012-10-01

While chronic alcohol consumption is known to decrease bone mineral content (BMC), bone mineral density (BMD), and negatively modify trabecular bone microarchitecture, the impact of alcohol on cortical microarchitecture is still unclear. The aim of this study was to investigate the effects of various doses of alcohol on bone density, trabecular and cortical parameters and bone strength in rats. Forty-eight male Wistar rats were divided into four groups: control (C), alcohol 25% v/v (A25), alcohol 30% v/v (A30) and alcohol 35% v/v (A35). Rats in the alcohol groups were fed a solution composed of ethanol and water for 17 weeks while the control group drank only water. Bone quality and quantity were evaluated through the analysis of density, trabecular and cortical bone microarchitectural parameters, osteocalcin and N-Telopeptide concentrations and a 3-point bending test. Bone density along with trabecular and cortical thickness were lower in alcohol groups compared to C. BMD was lower in A35 vs. A30 and cortical thickness was lower in A35 vs. A25 and A30. Pore number was increased by alcohol and the porosity was greater in A35 compared to C. N-Telopeptide concentration was decreased in alcohol groups compared to control whereas no differences were observed in osteocalcin concentrations. Maximal energy to failure was lower in A25 and A35 compared to C. Chronic ethanol consumption increases cortical bone damage in rats and may have detrimental effects on bone strength. These effects were dose-dependent, with greater negative effects proportionate to greater alcohol doses. Copyright © 2011 Société française de rhumatologie. Published by Elsevier SAS. All rights reserved.

Detection of Macromolecules in Desert Cyanobacteria Mixed with a Lunar Mineral Analogue After Space Simulations

NASA Astrophysics Data System (ADS)

Baqué, Mickael; Verseux, Cyprien; Rabbow, Elke; de Vera, Jean-Pierre Paul; Billi, Daniela

2014-09-01

In the context of future exposure missions in Low Earth Orbit and possibly on the Moon, two desert strains of the cyanobacterium Chroococcidiopsis, strains CCMEE 029 and 057, mixed or not with a lunar mineral analogue, were exposed to fractionated fluencies of UVC and polychromatic UV (200-400 nm) and to space vacuum. These experiments were carried out within the framework of the BIOMEX (BIOlogy and Mars EXperiment) project, which aims at broadening our knowledge of mineral-microorganism interaction and the stability/degradation of their macromolecules when exposed to space and simulated Martian conditions. The presence of mineral analogues provided a protective effect, preserving survivability and integrity of DNA and photosynthetic pigments, as revealed by testing colony-forming abilities, performing PCR-based assays and using confocal laser scanning microscopy. In particular, DNA and pigments were still detectable after 500 kJ/m2 of polychromatic UV and space vacuum (10-4 Pa), corresponding to conditions expected during one-year exposure in Low Earth Orbit on board the EXPOSE-R2 platform in the presence of 0.1 % Neutral Density (ND) filter. After exposure to high UV fluencies (800 MJ/m2) in the presence of minerals, however, altered fluorescence emission spectrum of the photosynthetic pigments were detected, whereas DNA was still amplified by PCR. The present paper considers the implications of such findings for the detection of biosignatures in extraterrestrial conditions and for putative future lunar missions.

Detection of macromolecules in desert cyanobacteria mixed with a lunar mineral analogue after space simulations.

PubMed

Baqué, Mickael; Verseux, Cyprien; Rabbow, Elke; de Vera, Jean-Pierre Paul; Billi, Daniela

2014-09-01

In the context of future exposure missions in Low Earth Orbit and possibly on the Moon, two desert strains of the cyanobacterium Chroococcidiopsis, strains CCMEE 029 and 057, mixed or not with a lunar mineral analogue, were exposed to fractionated fluencies of UVC and polychromatic UV (200-400 nm) and to space vacuum. These experiments were carried out within the framework of the BIOMEX (BIOlogy and Mars EXperiment) project, which aims at broadening our knowledge of mineral-microorganism interaction and the stability/degradation of their macromolecules when exposed to space and simulated Martian conditions. The presence of mineral analogues provided a protective effect, preserving survivability and integrity of DNA and photosynthetic pigments, as revealed by testing colony-forming abilities, performing PCR-based assays and using confocal laser scanning microscopy. In particular, DNA and pigments were still detectable after 500 kJ/m(2) of polychromatic UV and space vacuum (10(-4) Pa), corresponding to conditions expected during one-year exposure in Low Earth Orbit on board the EXPOSE-R2 platform in the presence of 0.1 % Neutral Density (ND) filter. After exposure to high UV fluencies (800 MJ/m(2)) in the presence of minerals, however, altered fluorescence emission spectrum of the photosynthetic pigments were detected, whereas DNA was still amplified by PCR. The present paper considers the implications of such findings for the detection of biosignatures in extraterrestrial conditions and for putative future lunar missions.

Reactive oxygen species on bone mineral density and mechanics in Cu,Zn superoxide dismutase (Sod1) knockout mice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smietana, Michael J.; Arruda, Ellen M.; Mechanical Engineering, University of Michigan, 2250 GG Brown, 2350 Hayward, Ann Arbor, MI 48109

Research highlights: {yields} Reactive oxygen species (ROS) are considered to be a factor in the onset of a number of age-associated conditions, including loss of BMD. {yields} Cu,Zn-superoxide dismutase (Sod1) deficient mice have increased ROS, reduced bone mineral density, decreased bending stiffness, and decreased strength compared to WT controls. {yields} Increased ROS caused by the deficiency of Sod1, may be responsible for the changes in BMD and bone mechanics and therefore represent an appropriate model for studying mechanisms of age-associated bone loss. -- Abstract: Reactive oxygen species (ROS) play a role in a number of degenerative conditions including osteoporosis. Micemore » deficient in Cu,Zn-superoxide dismutase (Sod1) (Sod1{sup -/-} mice) have elevated oxidative stress and decreased muscle mass and strength compared to wild-type mice (WT) and appear to have an accelerated muscular aging phenotype. Thus, Sod1{sup -/-} mice may be a good model for evaluating the effects of free radical generation on diseases associated with aging. In this experiment, we tested the hypothesis that the structural integrity of bone as measured by bending stiffness (EI; N/mm{sup 2}) and strength (MPa) is diminished in Sod1{sup -/-} compared to WT mice. Femurs were obtained from male and female WT and Sod1{sup -/-} mice at 8 months of age and three-point bending tests were used to determine bending stiffness and strength. Bones were also analyzed for bone mineral density (BMD; mg/cc) using micro-computed tomography. Femurs were approximately equal in length across all groups, and there were no significant differences in BMD or EI with respect to gender in either genotype. Although male and female mice demonstrated similar properties within each genotype, Sod1{sup -/-} mice exhibited lower BMD and EI of femurs from both males and females compared with gender matched WT mice. Strength of femurs was also lower in Sod1{sup -/-} mice compared to WT as well as between genders. These data indicate that increased oxidative stress, due to the deficiency of Sod1 is associated with decreased bone stiffness and strength and Sod1{sup -/-} mice may represent an appropriate model for studying disease processes in aging bone.« less

Objectively measured physical activity and bone strength in 9-year-old boys and girls.

PubMed

Sardinha, Luís B; Baptista, Fátima; Ekelund, Ulf

2008-09-01

The purpose of this work was to analyze the relationship between intensity and duration of physical activity and composite indices of femoral neck strength and bone-mineral content of the femoral neck, lumbar spine, and total body. Physical activity was assessed by accelerometry in 143 girls and 150 boys (mean age: 9.7 years). Measurement of bone-mineral content, femoral neck bone-mineral density, femoral neck width, hip axis length, and total body fat-free mass was performed with dual-energy radiograph absorptiometry. Compressive [(bone-mineral density x femoral neck width/weight)] and bending strength [(bone-mineral density x femoral neck width(2))/(hip axis length x weight)] express the forces that the femoral neck has to withstand in weight bearing, whereas impact strength [(bone-mineral density x femoral neck width x hip axis length)/(height x weight)] expresses the energy that the femoral neck has to absorb in an impact from standing height. Analysis of covariance (fat-free mass and age adjusted) showed differences between boys and girls of approximately 9% for compressive, 10% for bending, and 9% for impact strength. Stepwise regression analysis using time spent at sedentary, light, moderate, and vigorous physical activity as predictors revealed that vigorous physical activity explained 5% to 9% of femoral neck strength variable variance in both genders, except for bending strength in boys, and approximately 1% to 3% of total body and femoral neck bone-mineral content variance. Vigorous physical activity was then used to categorize boys and girls into quartiles. Pairwise comparison indicated that boys in the third and fourth quartiles (accumulation of >26 minutes/day) demonstrated higher compressive (11%-12%), bending (10%), and impact (14%) strength than boys in the first quartile. In girls, comparison revealed a difference between the fourth (accumulation of >25 minutes/day) and first quartiles for bending strength (11%). We did not observe any relationship between physical activity and lumbar spine strength. Femoral neck strength is higher in boys than girls. Vigorous intensity emerged as the main physical activity predictor of femoral neck strength but did not explain gender differences. Daily vigorous physical activity for at least approximately 25 minutes seems to improve femoral neck bone health in children.

Bisphosphonate Treatment for Children With Disabling Conditions

PubMed Central

Boyce, Alison M.; Tosi, Laura L.; Paul, Scott M.

2014-01-01

Fractures are a frequent source of morbidity in children with disabling conditions. The assessment of bone density in this population is challenging, because densitometry is influenced by dynamic forces affecting the growing skeleton and may be further confounded by positioning difficulties and surgical hardware. First-line treatment for pediatric osteoporosis involves conservative measures, including optimizing the management of underlying conditions, maintaining appropriate calcium and vitamin D intake, encouraging weight-bearing physical activity, and monitoring measurements of bone mineral density. Bisphosphonates are a class of medications that increase bone mineral density by inhibiting bone resorption. Although bisphosphonates are commonly prescribed for treatment of adult osteoporosis, their use in pediatric patients is controversial because of the lack of long-term safety and efficacy data. PMID:24368091

Bone mineral density in children with acute leukemia and its associated factors in Iran: a case-control study.

PubMed

Bordbar, Mohammad Reza; Haghpanah, Sezaneh; Dabbaghmanesh, Mohammad Hossein; Omrani, Gholamhossein Ranjbar; Saki, Forough

2016-12-01

Acute leukemia is the most common malignancy in children. We showed that low bone mass is prevalent among children with leukemia, especially in femur. Serum calcium, exercise, chemotherapy protocol, and radiotherapy are the main contributing factors. We suggest that early diagnosis and treatment of this problem could improve bone health in them. Acute leukemia is the most common malignancy in children and has been reported to be associated with low bone mass. Due to lack of sufficient data about the bone mineral density of children with leukemia in the Middle East, and inconsistencies between possible associated factors contributing to decreasing bone density in these children, we aimed to conduct a case-control study in Iran. This case-control study was conducted on 60 children with acute leukemia and 60 age- and sex-matched healthy controls. Anthropometric data, sun exposure, puberty, physical activity, and mineral biochemical parameters were assessed. Bone mineral density (BMD) was measured by dual-energy X-ray absorptiometry (DEXA). Data analysis was done by SPSS software v. 21. Serum calcium was higher in the control group (P = 0.012) while serum phosphorous, alkaline phosphatase, and serum 25(OH)D 3 were higher in children with leukemia with P values of 0.04, 0.002, and 0.036, respectively. Sun exposure and physical activity were more in healthy controls (P values <0.001 and 0.003, respectively). Prevalence of vitamin D deficiency in case and control groups was 57.8 and 79.4 %, respectively. This prevalence was higher in healthy controls (P value = 0.007). Both lumbar and femoral neck bone mineral apparent density (BMAD) were higher in the control group (P value <0.001). Serum calcium, physical activity, and radiotherapy were the most relevant factors associated with lumbar BMAD. Femoral neck BMAD was associated with chemotherapy protocol. Low bone mass for chronological age is prevalent among children with leukemia, especially in the femoral neck. Serum calcium, physical activity, chemotherapy protocol, and radiotherapy are the main contributing factors.

Bone mineral density and risk of type 2 diabetes and coronary heart disease: A Mendelian randomization study.

PubMed

Gan, Wei; Clarke, Robert J; Mahajan, Anubha; Kulohoma, Benard; Kitajima, Hidetoshi; Robertson, Neil R; Rayner, N William; Walters, Robin G; Holmes, Michael V; Chen, Zhengming; McCarthy, Mark I

2017-01-01

Background: Observational studies have demonstrated that increased bone mineral density is associated with a higher risk of type 2 diabetes (T2D), but the relationship with risk of coronary heart disease (CHD) is less clear. Moreover, substantial uncertainty remains about the causal relevance of increased bone mineral density for T2D and CHD, which can be assessed by Mendelian randomisation studies.  Methods: We identified 235 independent single nucleotide polymorphisms (SNPs) associated at p <5×10 -8 with estimated heel bone mineral density (eBMD) in 116,501 individuals from the UK Biobank study, accounting for 13.9% of eBMD variance. For each eBMD-associated SNP, we extracted effect estimates from the largest available GWAS studies for T2D (DIAGRAM: n=26,676 T2D cases and 132,532 controls) and CHD (CARDIoGRAMplusC4D: n=60,801 CHD cases and 123,504 controls). A two-sample design using several Mendelian randomization approaches was used to investigate the causal relevance of eBMD for risk of T2D and CHD. In addition, we explored the relationship of eBMD, instrumented by the 235 SNPs, on 12 cardiovascular and metabolic risk factors. Finally, we conducted Mendelian randomization analysis in the reverse direction to investigate reverse causality. Results: Each one standard deviation increase in genetically instrumented eBMD (equivalent to 0.14 g/cm 2 ) was associated with an 8% higher risk of T2D (odds ratio [OR] 1.08; 95% confidence interval [CI]: 1.02 to 1.14; p =0.012) and 5% higher risk of CHD (OR 1.05; 95%CI: 1.00 to 1.10; p =0.034). Consistent results were obtained in sensitivity analyses using several different Mendelian randomization approaches. Equivalent increases in eBMD were also associated with lower plasma levels of HDL-cholesterol and increased insulin resistance. Mendelian randomization in the reverse direction using 94 T2D SNPs or 52 CHD SNPs showed no evidence of reverse causality with eBMD. Conclusions: These findings suggest a causal relationship between elevated bone mineral density with risks of both T2D and CHD.

Bone Metabolism on ISS Missions

NASA Technical Reports Server (NTRS)

Smith, S. M.; Heer, M. A.; Shackelford, L. C.; Zwart, S. R.

2014-01-01

Spaceflight-induced bone loss is associated with increased bone resorption (1, 2), and either unchanged or decreased rates of bone formation. Resistive exercise had been proposed as a countermeasure, and data from bed rest supported this concept (3). An interim resistive exercise device (iRED) was flown for early ISS crews. Unfortunately, the iRED provided no greater bone protection than on missions where only aerobic and muscular endurance exercises were available (4, 5). In 2008, the Advanced Resistive Exercise Device (ARED), a more robust device with much greater resistance capability, (6, 7) was launched to the ISS. Astronauts who had access to ARED, coupled with adequate energy intake and vitamin D status, returned from ISS missions with bone mineral densities virtually unchanged from preflight (7). Bone biochemical markers showed that while the resistive exercise and adequate energy consumption did not mitigate the increased bone resorption, bone formation was increased (7, 8). The typical drop in circulating parathyroid hormone did not occur in ARED crewmembers. In 2014, an updated look at the densitometry data was published. This study confirmed the initial findings with a much larger set of data. In 42 astronauts (33 male, 9 female), the bone mineral density response to flight was the same for men and women (9), and those with access to the ARED did not have the typical decrease in bone mineral density that was observed in early ISS crewmembers with access to the iRED (Figure 1) (7). Biochemical markers of bone formation and resorption responded similarly in men and women. These data are encouraging, and represent the first in-flight evidence in the history of human space flight that diet and exercise can maintain bone mineral density on long-duration missions. However, the maintenance of bone mineral density through bone remodeling, that is, increases in both resorption and formation, may yield a bone with strength characteristics different from those that existed before space flight. Studies to assess bone strength after flight are underway at NASA, to better understand the results of bone remodeling. Studies are also underway to evaluate optimized exercise protocols and nutritional countermeasures. Regardless, there is clear evidence of progress being made to protect bone during spaceflight.

Bone mineral density is decreased in fibromyalgia syndrome: a systematic review and meta-analysis.

PubMed

Upala, Sikarin; Yong, Wai Chung; Sanguankeo, Anawin

2017-04-01

Previous studies have shown that fibromyalgia syndrome (FMS) is associated with low level of physical activity and exercise, which may lead to an increased risk of osteoporosis. However, studies of bone mineral density (BMD) in fibromyalgia have shown conflicting results. Thus, we conducted a systematic review and meta-analysis to better characterize the association between FMS and BMD. A comprehensive search of the databases MEDLINE and EMBASE was performed from inception through May 2016. The inclusion criterion was the observational studies' assessment of the association between fibromyalgia and bone mineral density in adult subjects. Fibromyalgia was diagnosed in accordance with the American College of Rheumatology criteria for the diagnosis of fibromyalgia syndrome. BMD was measured at the lumbar spine and femoral neck by dual-energy X-ray absorptiometry. Pooled mean difference (MD) of BMD at each site and 95% confidence interval (CI) were calculated using a random-effect, generic inverse variance method. The between-study heterogeneity of effect size was quantified using the Q statistic and I 2 . Data were extracted from four observational studies involving 680 subjects. At lumbar spine (L2-L4), BMD is significantly decreased in patients with FMS compared with controls with pooled MD of -0.02 (95% CI -0.03 to -0.01, P value = 0.003, I 2  = 0%) (Fig. 1). At femoral neck, BMD is not significantly decreased in patients with FMS compared with controls with pooled MD of 0.01 (95% CI -0.02 to 0.01, P value = 0.23, I 2  = 0%) (Fig. 2). In this meta-analysis, we observe that BMD at lumbar spine is decreased in FMS compared with normal individuals. Patients with FMS should be assessed for risk of osteoporosis. Fig. 1 Forest plot of bone mineral density at the lumbar spine, for patients with and without fibromyalgia syndrome. CI-confidence interval Fig. 2 Forest plot of bone mineral density at the femoral neck, for patients with and without fibromyalgia syndrome. CI-confidence interval.

The association between high plasma homocysteine levels and lower bone mineral density in Slovak women: the impact of vegetarian diet.

PubMed

Krivosíková, Zora; Krajcovicová-Kudlácková, Marica; Spustová, Viera; Stefíková, Kornélia; Valachovicová, Martina; Blazícek, Pavel; Nĕmcová, Tatiana

2010-04-01

A long-term vegetarian diet is generally poor in vitamin B group. The lack of vitamin B(12) together with vitamin B(6) and folate deficiency is closely related to homocysteine metabolism. Hyperhomocysteinemia was found to be associated with increased bone turnover markers and increased fracture risk. Thus, hyperhomocysteinemia, vitamin B(12) and folate deficiency may be regarded as novel risk factors for micronutrient deficiency-related osteoporosis. To assess the possible impact of a vegetarian diet on bone mineral density in cohort of Slovak vegetarian women. Fasting serum glucose, albumin, calcium, phosphorous and creatinine as well as bone markers, serum vitamin B(12), folate and plasma levels of total homocysteine were assessed in two nutritional groups (vegetarians vs. nonvegetarians) of apparently healthy women (age range 20-70 years). Bone mineral density of the femoral neck, trochanter, total femur and lumbar spine was measured in all subjects. Vegetarians had a significantly lower weight (p < 0.05), higher PTH (p < 0.01) and homocysteine (p < 0.001). Vitamin B(12) was significantly higher in nonvegetarians (p < 0.001). No differences were observed in folate levels. Univariate analysis showed significant association between homocysteine and B(12) (p < 0.01), folate (p < 0.001), creatinine (p < 0.001), total proteins (p < 0.049), age (p < 0.001) and vegetarian food intake (p < 0.001). Vegetarians had a significantly lower TrFBMD (p < 0.05) and ToFBMD (p < 0.05). Age and CTx were significant predictors in all sites of measured BMD and PTH. A strong correlation between homocysteine and FNBMD (r = -0.2009, p < 0.002), TrFBMD (r = -0.1810, p < 0.004) and ToFBMD (r = -0.2225, p < 0.001) was found in all subjects. Homocysteine is one of the predictors of bone mineral density, and hyperhomocysteinemia is associated with lower bone mineral density. In healthy adults, homocysteine levels are dependent on age as well as on nutritional habits. Thus, elderly women on a vegetarian diet seem to be at higher risk of osteoporosis development than nonvegetarian women.

Lower Serum Creatinine Is Associated with Low Bone Mineral Density in Subjects without Overt Nephropathy

PubMed Central

Huh, Ji Hye; Choi, Soo In; Lim, Jung Soo; Chung, Choon Hee; Shin, Jang Yel; Lee, Mi Young

2015-01-01

Background Low skeletal muscle mass is associated with deterioration of bone mineral density. Because serum creatinine can serve as a marker of muscle mass, we evaluated the relationship between serum creatinine and bone mineral density in an older population with normal renal function. Methods Data from a total of 8,648 participants (4,573 men and 4,075 postmenopausal women) aged 45–95 years with an estimated glomerular filtration rate >60 ml/min/1.73 m2 were analyzed from the Fourth Korea National Health and Nutrition Examination Survey (2008–2010). Bone mineral density (BMD) and appendicular muscle mass (ASM) were measured using dual-energy X-ray absorptiometry. Receiver operating characteristic curve analysis revealed that the cut points of serum creatinine for sarcopenia were below 0.88 mg/dl in men and 0.75 mg/dl in women. Subjects were divided into two groups: low creatinine and upper normal creatinine according to the cut point value of serum creatinine for sarcopenia. Results In partial correlation analysis adjusted for age, serum creatinine was positively associated with both BMD and ASM. Subjects with low serum creatinine were at a higher risk for low BMD (T-score ≤ –1.0) at the femur neck, total hip and lumbar spine in men, and at the total hip and lumbar spine in women after adjustment for confounding factors. Each standard deviation increase in serum creatinine was significantly associated with reduction in the likelihood of low BMD at the total hip and lumbar spine in both sexes (men: odds ratio (OR) = 0.84 [95% CI = 0.74−0.96] at the total hip, OR = 0.8 [95% CI = 0.68−0.96] at the lumbar spine; women: OR = 0.83 [95% CI = 0.73–0.95] at the total hip, OR=0.81 [95% CI = 0.67–0.99] at the lumbar spine). Conclusions Serum creatinine reflected muscle mass, and low serum creatinine was independently associated with low bone mineral density in subjects with normal kidney function. PMID:26207750

Quantitative calcaneal ultrasound parameters and bone mineral density at final height in girls treated with depot gonadotrophin-releasing hormone agonist for central precocious puberty or idiopathic short stature.

PubMed

Kapteijns-van Kordelaar, Simone; Noordam, Kees; Otten, Barto; van den Bergh, Joop

2003-11-01

To evaluate the effect of gonadotrophin-releasing hormone (GnRH) agonist treatment on bone quality at final height, we studied girls with central precocious puberty (CPP) and with idiopathic short stature (ISS). A total of 25 Caucasian girls were included: group A (n=14) with idiopathic CPP (mean age at start 7.4 years) and group B (n=11) with ISS (mean age at start 11.7 years). Treatment duration was 3.8 and 1.7 years respectively. The quantitative ultrasound parameters (QUS) broadband ultrasound attenuation (BUA) and speed of sound (SOS) were measured at the calcaneus (UBIS 3000 device). Lumbar spine bone mineral density (BMD; L2-L4) was measured by dual energy X-ray absorptiometry (DXA) (Hologic QDR1000). Measurements were performed at final height and expressed as Z-scores corrected for bone age. Mean Z-scores of QUS parameters, areal BMD and volumetric BMD (BMDvol) were above -1 in both groups (group A: BUA Z-score -0.21, SOS Z-score -0.29, BMD Z-score 0.02, BMDvol Z-score 0.05, group B: BUA Z-score -0.93, SOS Z-score -0.40, BMD Z-score -0.86, BMDvol Z-score -0.68), although mean Z-scores of BUA and areal BMD in group B were significantly different from zero (P=0.03 and P=0.02 respectively). Mean Z-score BMDvol was not significantly different from zero (P=0.05), we found no significant difference between the groups for BMDvol (P=0.13). Although quantitative ultrasound parameters parameters and bone mineral density were normal in girls with central precocious puberty at final height after gonadotrophin-releasing hormone agonist treatment, mean Z-score for broadband ultrasound attenuation and areal bone mineral density were significantly different from zero and mean Z-score for volumetric bone mineral density was (just) not significantly different from zero in idiopathic short stature girls with normal puberty treated with gonadotrophin-releasing hormone agonists. Therefore we cannot say that this treatment is safe in these girls with regard to bone health.

Performance and Emission Characteristics of a Compression Ignition Engine Operating on Blends of Castor Oil Biodiesel-Diesel

NASA Astrophysics Data System (ADS)

Kanwar, Roopesh; Sharma, Pushpendra Kumar; Singh, Aditya Narayan; Agrawal, Yadvendra Kumar

2017-04-01

Diesel vehicles are the nerves and veins of transportation, particularly in developing countries. With the rapid rate of modernization, increasing demand of fuel is inevitable. The exponential increase in fuel prices and the scarcity of its supply from the environment have promoted interest in the development of alternative sources of fuel. In this work, genus Ricinus communis L. was studied in order to delimit their potential as a raw material for biodiesel production. Further, castor oil, ethyl ester were prepared by transesterification using potassium hydroxide (KOH) as a catalyst and tested on a four-stroke, single-cylinder compression ignition engine. The test was carried out at a constant speed of 3000 rpm at different loads. The results represent a substantial decrease in carbon monoxide (CO) emission with an increasing biodiesel percentage. The reduction of CO in B05, B10, B15 and B20 averaged 11.75, 22.02, 24.23 and 28.79 %, respectively, compared to mineral diesel. The emission results of the comparative test indicated that CO, oxygen (O2) and smoke density emissions are found to be lower when the engine is filled with B05, B10, B15 and B20 as compared to mineral diesel, while carbon dioxide (CO2) and nitrogen oxide (NOx) with B05, B10, B15 and B20 are found to increase marginally. Brake thermal efficiency and brake specific fuel consumption decrease and increase respectively in biodiesel with different blends in comparison of mineral diesel.

Water circulation and global mantle dynamics: Insight from numerical modeling

NASA Astrophysics Data System (ADS)

Nakagawa, Takashi; Nakakuki, Tomoeki; Iwamori, Hikaru

2015-05-01

We investigate water circulation and its dynamical effects on global-scale mantle dynamics in numerical thermochemical mantle convection simulations. Both dehydration-hydration processes and dehydration melting are included. We also assume the rheological properties of hydrous minerals and density reduction caused by hydrous minerals. Heat transfer due to mantle convection seems to be enhanced more effectively than water cycling in the mantle convection system when reasonable water dependence of viscosity is assumed, due to effective slab dehydration at shallow depths. Water still affects significantly the global dynamics by weakening the near-surface oceanic crust and lithosphere, enhancing the activity of surface plate motion compared to dry mantle case. As a result, including hydrous minerals, the more viscous mantle is expected with several orders of magnitude compared to the dry mantle. The average water content in the whole mantle is regulated by the dehydration-hydration process. The large-scale thermochemical anomalies, as is observed in the deep mantle, is found when a large density contrast between basaltic material and ambient mantle is assumed (4-5%), comparable to mineral physics measurements. Through this study, the effects of hydrous minerals in mantle dynamics are very important for interpreting the observational constraints on mantle convection.

Altered auditory and vestibular functioning in individuals with low bone mineral density: a systematic review.

PubMed

Singh, Niraj Kumar; Jha, Raghav Hira; Gargeshwari, Aditi; Kumar, Prawin

2018-01-01

Alteration in the process of bone remodelling is associated with falls and fractures due to increased bone fragility and altered calcium functioning. The auditory system consists of skeletal structures and is, therefore, prone to getting affected by altered bone remodelling. In addition, the vestibule consists of huge volumes of calcium (CaCO3) in the form of otoconia crystals and alteration in functioning calcium levels could, therefore, result in vestibular symptoms. Thus, the present study aimed at compiling information from various studies on assessment of auditory or vestibular systems in individuals with reduced bone mineral density (BMD). A total of 1977 articles were searched using various databases and 19 full-length articles which reported auditory and vestibular outcomes in persons with low BMD were reviewed. An intricate relationship between altered BMD and audio-vestibular function was evident from the studies; nonetheless, how one aspect of hearing or balance affects the other is not clear. Significant effect of reduced bone mineral density could probably be due to the metabolic changes at the level of cochlea, secondary to alterations in BMD. One could also conclude that sympathetic remodelling is associated with vestibular problems in individual; however, whether vestibular problems lead to altered BMD cannot be ascertained with confidence. The studies reviewed in the article provide an evidence of possible involvement of hearing and vestibular system abnormalities in individuals with reduced bone mineral density. Hence, the assessment protocol for these individuals must include hearing and balance evaluation as mandatory for planning appropriate management.

Serum myostatin in central south Chinese postmenopausal women: Relationship with body composition, lipids and bone mineral density.

PubMed

Ma, Yulin; Li, Xianping; Zhang, Hongbin; Ou, Yangna; Zhang, Zhimin; Li, Shuang; Wu, Feng; Sheng, Zhifeng; Liao, Eryuan

2016-08-01

Previous data suggest that myostatin has direct effects on the proliferation and differentiation of osteoprogenitor cells. The relationships between serum myostatin, body composition lipids and bone mineral density in postmenopausal women remain unclear. The aim of this study is to elucidate the relationships between serum myostatin, body composition, lipids and bone mineral density in central south Chinese postmenopausal women. A cross-sectional study was conducted in 175 healthy postmenopausal women, aged 51-75 years old. Bone mineral density (BMD) and body composition were measured by double energy X-ray absorptiometry (DXA). Serum myostatin, 25-dihydroxyvitamin D(25OH-D), parathyroid hormone (PTH), bone alkaline phosphatase (BAP) and carboxy-terminal telopeptide of type I collagen (CTX) were measured by enzyme-linked immunoabsorbent assay (ELISA). In contrast to the osteoporotic women, the women without osteoporosis had higher BMI, fat mass and lean mass (P<0.01). The osteoporotic women were older than women without osteoporosis (P<0.01). There were no differences between two groups with regard to serum BAP, CTX, (25OH-D), PTH, lipids and myostatin after adjusted by age. BMD at each site was positively correlated with age at menopause, fat mass and lean mass, and also negatively correlated with age and serum BAP. Serum myostatin was positively correlated with tryglicerides, not correlated with either body composition or BMD at each site. Our data indicated that serum myostatin concentration did not correlate with muscle and bone mass. Further studies are needed to demonstrate the role of myostatin in regulating the bone metabolism.

[The risk factor for low bone mineral density in patients with inflammatory bowel disease].

PubMed

Liu, Jian-bin; Gao, Xiang; Zhang, Fang-bin; Yang, Li; Xiao, Ying-lian; Zhang, Rui-dong; Li, Zi-ping; Hu, Pin-jin; Chen, Min-hu

2009-10-01

To evaluate the prevalence of low bone mineral density in patients with inflammatory bowel disease (IBD)and to identify its risk factors. A cross-sectional survey was carried out in IBD patients. Anthropometric measures, biochemical markers of nutrition and bone mineral density measurement were completed for these patients as well as healthy control subjects. Seventy-seven Crohn's disease (CD) and 43 ulcerative colitis (UC) patients were enrolled, and 37 healthy volunteers were recruited as healthy controls (HC). The T value of CD patients, UC patients and HC was -1.72 +/- 1.20, -1.26 +/- 1.12 and -0.62 +/- 0.87 respectively and the T value of CD patients was significantly lower than that of HC (P = 0.000). The prevalence of osteoporosis in CD, UC and HC was 23.3%, 14.0% and 0 respectively. The prevalence of osteoporosis in CD was higher than that in HC (P = 0.003). Logistic regression analysis indicated that low BMI (BMI < or = 18.4 kg/m(2)) was an independent risk factor for osteoporosis both in CD (OR = 11.25, 95%CI 3.198 - 39.580, P = 0.000) and in UC (OR = 14.50, 95%CI 1.058 - 88.200, P = 0.045) patients. Age, disease duration, clinical activity active index (CDAI), oral steroid therapy, immunosuppressant treatment and serum vitamin D concentration were not found to be correlated with osteoporosis in IBD patients. Low bone mineral density is common in both CD and UC patients and low BMI is an independent risk factor for osteoporosis in IBD patients.

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

PubMed

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.

Caries-removal effectiveness of a papain-based chemo-mechanical agent: A quantitative micro-CT study.

PubMed

Neves, Aline A; Lourenço, Roseane A; Alves, Haimon D; Lopes, Ricardo T; Primo, Laura G

2015-01-01

The aim of this study was to access the effectiveness and specificity of a papain-based chemo-mechanical caries-removal agent in providing minimum residual caries after cavity preparation. In order to do it, extracted carious molars were selected and scanned in a micro-CT before and after caries-removal procedures with the papain-based gel. Similar parameters for acquisition and reconstruction of the image stacks were used between the scans. After classification of the dentin substrate based on mineral density intervals and establishment of a carious tissue threshold, volumetric parameters related to effectiveness (mineral density of removed dentin volume and residual dentin tissue) and specificity (relation between carious dentin in removed volume and initial caries) of this caries-removal agent were obtained. In general, removed dentin volume was similar or higher than the initial carious volume, indicating that the method was able to effectively remove dentin tissue. Samples with an almost perfect accuracy in carious dentin removal also showed an increased removal of caries-affected tissue. On the contrary, less or no affected dentin was removed in samples where some carious tissue was left in residual dentin. Mineral density values in residual dentin were always higher or similar to the threshold for mineral density values in carious dentin. In conclusion, the papain-based gel was effective in removing carious dentin up to a conservative in vitro threshold. Lesion characteristics, such as activity and morphology of enamel lesion, may also influence caries-removal properties of the method. © Wiley Periodicals, Inc.

Bone mineral density in relation to efficacy and side effects of budesonide and prednisolone in Crohn's disease.

PubMed

Schoon, Erik J; Bollani, Simona; Mills, Peter R; Israeli, Eran; Felsenberg, Dieter; Ljunghall, Sverker; Persson, Tore; Haptén-White, Louise; Graffner, Hans; Bianchi Porro, Gabriele; Vatn, Morten; Stockbrügger, Reinhold W

2005-02-01

Osteoporosis frequently occurs in Crohn's disease, often because of corticosteroids. Budesonide as controlled release capsules is a locally acting corticosteroid with low systemic bioavailability. We investigated its effects on bone compared with prednisolone. In 34 international centers, 272 patients with Crohn's disease involving ileum and/or colon ascendens were randomized to once daily treatment with budesonide or prednisolone for 2 years at doses adapted to disease activity. One hundred eighty-one corticosteroid-free patients had active disease (98 had never received corticosteroids, corticosteroid naive; 83 had received corticosteroids previously, corticosteroid exposed), and 90 had quiescent disease, receiving long-term low doses of corticosteroids, corticosteroid-dependent; in 1 patient, no efficacy data were obtained. Bone mineral density and fractures were assessed in a double-blinded fashion; disease activity, side effects, and quality of life were monitored. Neither the corticosteroid-free nor the corticosteroid-dependent patients treated with budesonide differed significantly in bone mineral density from those receiving prednisolone. However, corticosteroid-naive patients receiving budesonide had smaller reductions in bone mineral density than those on prednisolone (mean, -1.04% vs -3.84%; P = .0084). Treatment-emergent corticosteroid side effects were less frequent with budesonide. Efficacy was similar in both groups. Treatment with budesonide is associated with better preserved bone mass compared with prednisolone in only the corticosteroid-naive patients with active ileocecal Crohn's disease. In both the corticosteroid-free and corticosteroid-dependent groups, budesonide and prednisolone were equally effective for up to 2 years, but budesonide caused fewer corticosteroid side effects.

Body composition and bone mineral density of collegiate American football players

PubMed Central

Turnagöl, Hüseyin Hüsrev

2016-01-01

Abstract The aim of this study was to compare whole and segmental body composition and bone mineral density of collegiate American football players by playing positions. Forty collegiate American football players voluntarily participated in this study. Participants were categorized by playing positions into one of five categories i.e., defensive linemen, offensive linemen, defensive secondary players, offensive secondary players and receivers. Whole body composition and bone mineral density were measured by dual x-ray absorptiometry. Offensive and defensive linemen had higher body mass, a body mass index, lean mass and a fat mass index compared to the remaining three positions and a higher lean mass index compared to offensive secondary players and receivers. Offensive linemen had a higher body fat percentage and lower values of upper to lower lean mass than offensive and defensive secondary players and receivers, and higher total mass to the lean mass ratio and fat mass to the lean mass ratio compared to the other players. Offensive linemen had a higher fat mass index and fat mass to the lean mass ratio than defensive linemen. However, in all other measures they were similar. Offensive and defensive secondary players and receivers were similar with respect to the measured variables. Bone mineral density of the players was within the normal range and no difference in lean mass was observed between the legs. In conclusion, findings of this study showed that the total and segmental body composition profile of collegiate American football players reflected the demands of particular playing positions. PMID:28149373

Ultraviolet-C irradiation to titanium implants increases peri-implant bone formation without impeding mineralization in a rabbit femur model.

PubMed

Yamazaki, Makoto; Yamada, Masahiro; Ishizaki, Ken; Sakurai, Kaoru

2015-05-01

Volume and bone quality of peri-implant supporting bone, in particular, at implant neck region, as well as bone-implant contact ratio, is important for long-term stability of implants. Ultraviolet-C (UVC) irradiation is known to enhance the osseointegration capability of titanium implants. However, the histological determination was performed only on a rat model, but not pre-clinical animal model such as a rabbit model. The purpose of this study was to determine the effects of UVC irradiation on titanium implants on the volume and mineral density of peri-implant supporting bone formation in a rabbit femur model. Acid-etched pure titanium screw implants with or without 3 mW/cm2 UVC irradiation for 48 h were placed in rabbit femur diaphyses. Peri-implant bone tissue formation was analyzed at 3 and 8 weeks post-operatively by histology and micro-CT-based bone morphometry after calibration with hydroxyl apatite phantoms. UVC pre-irradiated implants accumulated a higher density of cells and thicker and longer bone tissue attachments that continued into the inner basic lamellae of the surface of existing cortical bone at 3 and 8 weeks than the implants without irradiation. Although the bone mineral density around both implants was equivalent to that of the existing cortical bone, bone volume was greater with UVC pre-irradiation in two-thirds or more of the apical region throughout the observation period. These results indicate that UVC treatment increased the volume of cortical-like bone tissue in the coronal region of titanium implants without deterioration of bone mineral density.

Thyroid dysfunction in an adult female population: A population-based study of Latin American Vertebral Osteoporosis Study (LAVOS) - Puerto Rico site.

PubMed

González-Rodríguez, Loida A; Felici-Giovanini, Marcos E; Haddock, Lillian

2013-06-01

To determine the prevalence of hypothyroidism in an adult female population in Puerto Rico and to determine the relationship between hypothyroidism, bone mineral density and vertebral and non-vertebral fractures in this population. Data from the 400 subjects' database of the Latin American Vertebral Osteoporosis Study (LAVOS), Puerto Rico site was reviewed. Patient's medical history, anthropometric data, current medications, laboratories, and DXA results was extracted. Subjects with thyroid dysfunction were identified based on their previous medical history and levels of TSH. Bone Mineral Density was classified using the World Health Organization criteria. Crude prevalence of thyroid dysfunction were estimated with a confidence of 95% and weighted by the population distribution by age, according to the distribution by age group in the 2000 census. Bone mineral densities and prevalence of vertebral and non-vertebral fractures were compared among the groups. The weighted prevalence of hyperthyroidism in this population was 0.0043% (95% CI: -0.0021%, 0.0107%). The weighted prevalence of hypothyroidism was 24.2% (95% CI: 19.9%, 28.4%). Increased prevalence of hypothyroidism was found in participants 70 years or older. The mean BMD at spine, hip and femoral neck was similar among the groups. No difference in the proportion of participants with vertebral and non-vertebral fractures was found among the groups. Our study found a high prevalence of hypothyroidism among adult postmenopausal females in Puerto Rico. No association between hypothyroidism and decreased bone mineral densities, vertebral or non-vertebral fractures was found in this population.

[CIP and CAP fragments of parathormone and selected parameters of calcium-phosphate balance in patients with chronic kidney disease treated with repeated haemodialysis].

PubMed

Polak-Jonkisz, Dorota; Zwolińska, Danuta; Nahaczewska, Wiesława

2010-01-01

Chronic kidney disease (CKD) leads to bone and mineral complications, which are manifested, among others, by hyperparathyroidism, calcium-phosphate and vitamin D balance disturbances. The results of investigation assessing the usefulness of CAP/CIP ratio, (cyclase activating PTH/cyclase inactive PTH) as a marker of bone turnover and bone disturbances in this group of patients are contradictory. was to estimate the concentration of CAP and CIP of parathormone, connection with selected calcium-phosphate balance parameters and usefulness of CAP/CIP ratio to differentiate bone mineral density in patients with CKD treated with repeated haemodialysis. The study included 31 children aged 5 to 18 years. Group I - 15 haemodialysed children. Group II - 16 healthy children. The patients underwent the following serum measurements: calcium concentration (Ca), inorganic phosphate (P), 1.25-dihydroxyvitamin D, parathormone (intact PTH), and CAP, CIP were evaluated with Scantibodies Laboratory Inc test. In group I the densitometric examination was done using the Lunar DPX-L system, performing the overall bone measurement. In children from group I the average values of iPTH concentration and both CIP and CAP components were significantly elevated (p<0.05) as compared to group II. CAP/CIP ratio in group I was <1; in healthy children >1. Average concentrations of Ca and 1.25(OH)2D in serum of group I were lowered, although without statistical significance in comparison with group II. CAP/CIP ratio does not differentiate the children with bone disturbances. Densitometric examination revealed osteopenic changes in 3 children and osteoporosis in 2 children. There were no statistically significant correlations between the examined parameters. 1. The CIP/CAP ratio does not differentiate the bone mineral density status and it is not associated with biochemical parameters of calcium-phosphate metabolism. 2. This indicates its poor diagnostic utility with reference to mineralization disturbances in children with chronic kidney disease.

Phytate levels and bone parameters: a retrospective pilot clinical trial.

PubMed

Lopez-Gonzalez, Angel A; Grases, Felix; Perello, Joan; Tur, Fernando; Costa-Bauza, Antonia; Monroy, Nieves; Mari, Bartolome; Vicente-Herrero, Teofila

2010-06-01

This study evaluated the relationship between phytate urinary levels and bone characteristics in a large population of postmenopausal women. The study population consisted of 180 postmenopausal women who participated in a descriptive cross-sectional study. A urine sample was collected from each subject to determine phytate levels and the volunteers were divided into two groups according to phytate urinary concentration (i.e., low and high levels). Bone mineral density was determined in the lumbar spine and femoral neck of groups with low and high phytate urinary levels. Urinary levels of phytate were linked to dietary phytate consumption. Hence, bone mineral density values were significantly higher in the lumbar spines and femoral necks of women who consumed high levels of phytate than in women with low urinary phytate concentrations. Higher urinary levels of phytate correlated with higher bone mineral density in the lumbar spine and femoral necks of postmenopausal women. This finding demonstrates the potential use of phytate in the treatment of bone related diseases, as it uses a mechanism of action similar to some bisphosphonates.

Bone health in Down syndrome.

PubMed

García-Hoyos, Marta; Riancho, José Antonio; Valero, Carmen

2017-07-21

Patients with Down syndrome have a number of risk factors that theoretically could predispose them to osteoporosis, such as early aging, development disorders, reduced physical activity, limited sun exposure, frequent comorbidities and use of drug therapies which could affect bone metabolism. In addition, the bone mass of these people may be affected by their anthropometric and body composition peculiarities. In general terms, studies in adults with Down syndrome reported that these people have lower areal bone mineral density (g/cm 2 ) than the general population. However, most of them have not taken the smaller bone size of people with Down syndrome into account. In fact, when body mineral density is adjusted by bone size and we obtain volumetric body mineral density (g/cm 3 ), the difference between both populations disappears. On the other hand, although people with Down syndrome have risk factor of hypovitaminosis D, the results of studies regarding 25(OH)D in this population are not clear. Likewise, the studies about biochemical bone markers or the prevalence of fractures are not conclusive. Copyright © 2017 Elsevier España, S.L.U. All rights reserved.

Grand-grand multiparity (more than 10 deliveries) does not convey a risk for osteoporosis.

PubMed

Turan, Volkan

2011-12-01

To examine whether multiparity is a risk factor for osteoporosis. Design. A retrospective evaluation. 16 grand-grand multiparous women and women who gave birth a maximum of three times (n= 15), aged 55-60 years. X-ray absorptiometry was used to examine lumbar spine (L(1) -L(4) ) and femoral bone mineral densities. The relation between parity and osteoporosis was investigated by separating the bone mineral density into three categories according to the score from the absorptiometry. The women had a similar body mass index and post-menopausal status, lumbar spine (L(1) -L(4) ) and femoral bone mineral densities. There was no relation between multiparity and osteoporosis development in the lumbar spine (r=-0.02; p=0.992) or total femoral (r=0.20; p=0.916) regions. Many pregnancies and childbirths along with long total lactation times do not appear to play a role in increasing the risk of osteoporosis at a more advanced age. © 2011 The Authors Acta Obstetricia et Gynecologica Scandinavica© 2011 Nordic Federation of Societies of Obstetrics and Gynecology.

Risk factors for osteoporosis and bone status in postmenopausal women with psoriasis treated with UVB therapy.

PubMed

Osmancevic, Amra; Landin-Wilhelmsen, Kerstin; Larkö, Olle; Mellström, Dan; Wennberg, Ann-Marie; Hulthén, Lena; Krogstad, Anne-Lene

2008-01-01

The aims of this study were to examine whether postmenopausal women with psoriasis who were exposed to regular ultraviolet light B (UVB) therapy had greater bone mineral density than women of similar age from the same region, and to estimate the influence of risk factors on bone status. A total of 35 randomly selected women, age (mean +/- SD) 69.3 +/- 6.29 years (age range 60-82 years), with active psoriasis, mean onset at 37.0 years (+/- 23.5 SD) were studied. The patients had been previously exposed to broadband or narrowband UVB. Age-matched, women (n = 2448) from Göteborg, examined at the Geriatric out-patient clinic during the years 2001 and 2002, were used as controls. Bone mineral density was examined by Dual-Energy X-ray Absorptiometry (Hologic Delphi A) at the hip and the lumbar spine. Medical history and lifestyle factors were assessed with a questionnaire. Postmenopausal women with psoriasis were found to have higher bone mineral density than age-matched controls. Higher body weight, physical activity and UVB exposure could explain this finding.

Water Storage and Related Physical Characteristics of Four Mineral Soils in North Central Minnesota

Treesearch

E. S. Verry

1969-01-01

Soil water storage in a 7.5 foot profile varied nearly 100 percent (7.9 to 15.5 inches) among four mineral soils ranging from a sand to sandy loam. Bulk density, size fractions, and four water retention values are tabulated for each horizon.

Fan-beam densitometry of the growing skeleton: are we measuring what we think we are?

PubMed

Cole, Jacqueline H; Scerpella, Tamara A; van der Meulen, Marjolein C H

2005-01-01

Magnification error in fan-beam densitometers varies with distance from the X-ray source to the bone measured and might obscure bone mineral changes in the growing skeleton. Magnification was examined by scanning aluminum rods of different shapes (square, rectangular, solid round, and hollow round) at four distances above the X-ray source in two orientations, with rods aligned parallel (SI) and perpendicular (ML) to the longitudinal axis of the scanning table. Measured area (cm(2)) decreased linearly with distance above the X-ray source for all rods in the SI orientation (p < 0.005). Measured mineral content (g) decreased linearly with distance but only for SI round rods (p < 0.0001) and for ML hollow round rods (p < 0.005). Area and mineral content decreased 1.6-1.8% per centimeter above the source for round rods. Measured mineral density (g/cm(2)) decreased linearly with distance from the source only for ML hollow round rods (p < 0.005). Variation in area, mineral content, and mineral density measurements was 6.6-6.9%, 6.9-7.5%, and 1.9-2.3%, respectively, for SI round rods. Magnification errors of this magnitude are problematic for clinical studies using fan-beam densitometry. Particularly in pediatric subjects, increases in soft tissue during normal growth could increase a bone's distance from the fan-beam source and result in apparent reductions in area and bone mineral content.

An Increased Risk of Osteoporosis during Acquired Immunodeficiency Syndrome.

PubMed

Annapoorna, N; Rao, G Venkateswara; Reddy, N S; Rambabu, P; Rao, K R S Samabasiva

2004-01-01

Osteoporosis is characterized by decreased bone mineral density and mechanistic imbalances of bone tissue that may result in reduced skeletal strength and an enhanced susceptibility to fractures. Osteoporosis in its most common form affects the elderly (both sexes) and all racial groups of human beings. Multiple environmental risk factors like acquired immune deficiency syndrome (AIDS) are believed to be one of the causes of osteoporosis. Recently a high incidence of osteoporosis has been observed in human immunodeficiency virus (HIV) infected individuals. The etiology of this occurrence in HIV infections is controversial. This problem seems to be more frequent in patients receiving potent antiretroviral therapy. In AIDS, the main suggested risk factors for the development of osteoporosis are use of protease inhibitors, longer duration of HIV infection, lower body weight before antiretroviral therapy, high viral load. Variations in serum parameters like osteocalcin, c-telopeptide, levels of elements like Calcium, Magnesium, Phosphorus, concentration of vitamin-D metabolites, lactate levels, bicarbonate concentrations, amount of alkaline phosphatase are demonstrated in the course of development of osteoporosis. OPG/RANKL/RANK system is final mediator of bone remodeling. Bone mineral density (BMD) test is of added value to assess the risk of osteoporosis in patients infected with AIDS. The biochemical markers also aid in this assessment. Clinical management mostly follows the lines of treatment of osteoporosis and osteopenia.

Decreases in bone blood flow and bone material properties in aging Fischer-344 rats

NASA Technical Reports Server (NTRS)

Bloomfield, Susan A.; Hogan, Harry A.; Delp, Michael D.

2002-01-01

The purpose of this study was to quantify precisely aging-induced changes in skeletal perfusion and bone mechanical properties in a small rodent model. Blood flow was measured in conscious juvenile (2 months old), adult (6 months old), and aged (24 months old) male Fischer-344 rats using radiolabeled microspheres. There were no significant differences in bone perfusion rate or vascular resistance between juvenile and adult rats. However, blood flow was lower in aged versus adult rats in the forelimb bones, scapulas, and femurs. To test for functional effects of this decline in blood flow, bone mineral density and mechanical properties were measured in rats from these two age groups. Bone mineral density and cross-sectional moment of inertia in femoral and tibial shafts and the femoral neck were significantly larger in the aged versus adult rats, resulting in increased (+14%-53%) breaking strength and stiffness. However, intrinsic material properties at midshaft of the long bones were 12% to 25% lower in the aged rats. Although these data are consistent with a potential link between decreased perfusion and focal alterations in bone remodeling activity related to clinically relevant bone loss, additional studies are required to establish the mechanisms for this putative relationship.

Application of Natural Mineral Additives in Construction

NASA Astrophysics Data System (ADS)

Linek, Malgorzata; Nita, Piotr; Wolka, Paweł; Zebrowski, Wojciech

2017-12-01

The article concerns the idea of using selected mineral additives in the pavement quality concrete composition. The basis of the research paper was the modification of cement concrete intended for airfield pavements. The application of the additives: metakaolonite and natural zeolite was suggested. Analyses included the assessment of basic physical properties of modifiers. Screening analysis, assessment of micro structure and chemical microanalysis were conducted in case of these materials. The influence of the applied additives on the change of concrete mix parameters was also presented. The impact of zeolite and metakaolinite on the mix density, oxygen content and consistency class was analysed. The influence of modifiers on physical and mechanical changes of the hardened cement concrete was discussed (concrete density, compressive strength and bending strength during fracturing) in diversified research periods. The impact of the applied additives on the changes of internal structure of cement concrete was discussed. Observation of concrete micro structure was conducted using the scanning electron microscope. According to the obtained lab test results, parameters of the applied modifiers and their influence on changes of internal structure of cement concrete are reflected in the increase of mechanical properties of pavement quality concrete. The increase of compressive and bending strength in case of all analysed research periods was proved.

A single injection of the anabolic bone agent, parathyroid hormone-collagen binding domain (PTH-CBD), results in sustained increases in bone mineral density for up to 12 months in normal female mice.

PubMed

Ponnapakkam, Tulasi; Katikaneni, Ranjitha; Suda, Hirofumi; Miyata, Shigeru; Matsushita, Osamu; Sakon, Joshua; Gensure, Robert C

2012-09-01

Parathyroid hormone (PTH) is the most effective osteoporosis treatment, but it is only effective if administered by daily injections. We fused PTH(1-33) to a collagen binding domain (PTH-CBD) to extend its activity, and have shown an anabolic bone effect with monthly dosing. We tested the duration of action of this compound with different routes of administration. Normal young C57BL/6J mice received a single intraperitoneal injection of PTH-CBD (320 μg/kg). PTH-CBD treated mice showed a 22.2 % increase in bone mineral density (BMD) at 6 months and 12.8 % increase at 12 months. When administered by subcutaneous injection, PTH-CBD again caused increases in BMD, 15.2 % at 6 months and 14.3 % at 12 months. Radiolabeled PTH-CBD was concentrated in bone and skin after either route of administration. We further investigated skin effects of PTH-CBD, and histological analysis revealed an apparent increase in anagen VI hair follicles. A single dose of PTH-CBD caused sustained increases in BMD by >10 % for 1 year in normal mice, regardless of the route of administration, thus showing promise as a potential osteoporosis therapy.

Unilateral vs bilateral hip bone mineral density measurement for the diagnosis of osteoporosis.

PubMed

Ikegami, Shota; Kamimura, Mikio; Uchiyama, Shigeharu; Mukaiyama, Keijiro; Kato, Hiroyuki

2014-01-01

It has not been established whether unilateral or bilateral hip dual-energy X-ray absorptiometry (DXA) is preferable for the diagnosis of osteoporosis. We investigated the discordance in DXA measurements in bilateral hips to determine whether unilateral DXA is valid for osteoporosis diagnosis. The subjects were 2964 Japanese patients without a previous diagnosis of primary osteoporosis. We measured bilateral femoral bone mineral density (BMD) and calculated indices, related to the unilateral results, for predicting contralateral hip osteoporosis. A likelihood ratio (LR) of a negative test (LR [-]) of less than 0.2 was considered to exclude the diagnosis. In the normal spinal BMD group, the sensitivity of unilateral DXA for women was 27-73% and LR (-) was 0.28-0.73; the sensitivity for men was 0-50% and LR (-) was 0.51-1.00; the diagnosis of contralateral osteoporosis was not excluded. Sensitivity increased and LR (-) increased with worsening spinal BMD status; however, LR (-) did not meet the cutoff for exclusion. We could exclude unilateral hip osteoporosis, in women only, by performing contralateral femoral DXA; this necessitated lowering the T-score cutoff from -2.5 to -2.0. Unilateral femoral DXA is not useful for excluding the diagnosis of contralateral hip osteoporosis. Copyright © 2014 The International Society for Clinical Densitometry. Published by Elsevier Inc. All rights reserved.

Parametric electrical impedance tomography for measuring bone mineral density in the pelvis using a computational model.

PubMed

Kimel-Naor, Shani; Abboud, Shimon; Arad, Marina

2016-08-01

Osteoporosis is defined as bone microstructure deterioration resulting a decrease of bone's strength. Measured bone mineral density (BMD) constitutes the main tool for Osteoporosis diagnosis, management, and defines patient's fracture risk. In the present study, parametric electrical impedance tomography (pEIT) method was examined for monitoring BMD, using a computerized simulation model and preliminary real measurements. A numerical solver was developed to simulate surface potentials measured over a 3D computerized pelvis model. Varying cortical and cancellous BMD were simulated by changing bone conductivity and permittivity. Up to 35% and 16% change was found in the real and imaginary modules of the calculated potential, respectively, while BMD changes from 100% (normal) to 60% (Osteoporosis). Negligible BMD relative error was obtained with SNR>60 [dB]. Position changes errors indicate that for long term monitoring, measurement should be taken at the same geometrical configuration with great accuracy. The numerical simulations were compared to actual measurements that were acquired from a healthy male subject using a five electrodes belt bioimpedance device. The results suggest that pEIT may provide an inexpensive easy to use tool for frequent monitoring BMD in small clinics during pharmacological treatment, as a complementary method to DEXA test. Copyright © 2016. Published by Elsevier Ltd.

Impact of Martial Arts (Judo, Karate, and Kung Fu) on Bone Mineral Density Gains in Adolescents of Both Genders: 9-Month Follow-Up.

PubMed

Ito, Igor H; Kemper, Han C G; Agostinete, Ricardo R; Lynch, Kyle R; Christofaro, Diego G D; Ronque, Enio R; Fernandes, Rômulo A

2017-11-01

To compare bone mineral density (BMD) gains in adolescents of both genders stratified according to different martial art styles in a 9-month follow-up study. The longitudinal study consisted of 29 adolescents of both genders and age between 11 and 17 years stratified into a control group (not engaged in any sport) and 50 fighters (kung fu/karate, n = 29; judo, n = 21). All 79 subjects underwent anthropometric measures (weight, height, leg length, and height set) and dual-energy X-ray absorptiometry (BMD, in g/cm 2 ) at 2 moments, baseline and 9 months later. Maturity offset (age at peak height velocity), lean soft tissue, chronological age, and resistance training were treated as covariates. Male judoists presented higher gains in BMD-spine [0.098 g/cm 2 (95% confidence interval, 0.068-0.128)] than control group [0.040 g/cm 2 (95% confidence interval, 0.011-0.069)] (post hoc test with P = .030). There was no effect of martial art on BMD gains among girls. Independently of gender, in all multivariate models, lean soft tissue constituted the most relevant covariate. Judo practice in adolescents affected the bone accrual significantly after 9-month follow-up compared with controls, mainly in boys.

The effects of clinical pilates exercises on bone mineral density, physical performance and quality of life of women with postmenopausal osteoporosis.

PubMed

Angın, Ender; Erden, Zafer; Can, Filiz

2015-01-01

The aim of this study was to investigate effects of Clinical Pilates Exercises on bone mineral density (BMD), physical performance and quality of life (QOL) in postmenopausal osteoporosis. Forty-one women were recruited to the study. The subjects were divided into two groups, as the Pilates group and the control group. Subjects were evaluated for BMD at the lumbar region. Physical performance level was measured. Pain intensity level was scored with Visual Analogue Scale. QUALEFFO-41 was used for assessing QOL. BMD values increased in the Pilates group (p < 0.05), while BMD decreased in the control group (p< 0.05). Physical performance test results showed significant increases in the Pilates group (p< 0.05) whereas there was no changes in the control group (p> 0.05). Pain intensity level in the Pilates group was significantly decreased after the exercise (p< 0.05), while it was unchanged in the control group. There were significant increases in all parameters of QOL in the Pilates group. Conversely, some parameters of QOL showed decreases in the control group (p< 0.05). Pilates Exercises is effective to increase BMD; QOL and walking distance and also beneficial to relieve pain. Physiotherapist can use Pilates Exercises for the subjects with osteoporosis in the clinics.

Analysis of Adhesive Characteristics of Asphalt Based on Atomic Force Microscopy and Molecular Dynamics Simulation.

PubMed

Xu, Meng; Yi, Junyan; Feng, Decheng; Huang, Yudong; Wang, Dongsheng

2016-05-18

Asphalt binder is a very important building material in infrastructure construction; it is commonly mixed with mineral aggregate and used to produce asphalt concrete. Owing to the large differences in physical and chemical properties between asphalt and aggregate, adhesive bonds play an important role in determining the performance of asphalt concrete. Although many types of adhesive bonding mechanisms have been proposed to explain the interaction forces between asphalt binder and mineral aggregate, few have been confirmed and characterized. In comparison with chemical interactions, physical adsorption has been considered to play a more important role in adhesive bonding between asphalt and mineral aggregate. In this study, the silicon tip of an atomic force microscope was used to represent silicate minerals in aggregate, and a nanoscale analysis of the characteristics of adhesive bonding between asphalt binder and the silicon tip was conducted via an atomic force microscopy (AFM) test and molecular dynamics (MD) simulations. The results of the measurements and simulations could help in better understanding of the bonding and debonding procedures in asphalt-aggregate mixtures during hot mixing and under traffic loading. MD simulations on a single molecule of a component of asphalt and monocrystalline silicon demonstrate that molecules with a higher atomic density and planar structure, such as three types of asphaltene molecules, can provide greater adhesive strength. However, regarding the real components of asphalt binder, both the MD simulations and AFM test indicate that the colloidal structural behavior of asphalt also has a large influence on the adhesion behavior between asphalt and silicon. A schematic model of the interaction between asphalt and silicon is presented, which can explain the effect of aging on the adhesion behavior of asphalt.

Study of the structural, vibrational and thermodynamic properties of natroxalate mineral using density functional theory

NASA Astrophysics Data System (ADS)

Colmenero, Francisco; Timón, Vicente

2018-07-01

Natroxalate mineral, Na2C2O4, is a fundamental oxalate mineral widespread in nature, present in humans, animals and plants, as well as in naturally occurring minerals. The characterization of oxalate minerals is extraordinarily important since these organic minerals are indicators of environmental events and of the presence of biological activity, because they are commonly of biological origin. These minerals are currently under study to investigate the possible biological activity on Mars. The identification of these compounds is usually performed by X-ray diffraction and Raman spectroscopy. Theoretical calculations are of great value for the study and interpretation of the results of these experimental techniques. In this work, natroxalate mineral structure and Raman spectrum was studied by first principle calculations based on the density functional theory. The computed structure of natroxalate reproduces the one determined experimentally by X-ray diffraction (monoclinic symmetry, space group P21/c; lattice parameters a = 3.449 Å, b = 5.243 Å; c = 10.375 Å). Lattice parameters, bond lengths, bond angles and X-ray powder pattern were found to be in very good agreement with their experimental counterparts. Raman spectrum was then computed by means of density functional perturbation theory and compared with the experimental spectrum. Since the results were also found in agreement with the experimental data, a normal mode analysis of the theoretical spectra was carried out and used in order to assign the main bands of the Raman spectrum. The band found at about 567 cm-1, described as a single peak in previous experimental works, is shown clearly to have two contributing bands. Finally, two bands of the observed spectrum, located at the wavenumbers 1750 and 1358 cm-1, were not found in the theoretical spectrum. This is because these bands correspond to an overtone, 2ν1 (ν1 = 875 cm-1), and a combination band, ν1 + ν2 (ν1,ν2 = 875, 481 cm-1), respectively. Finally, the fundamental thermodynamic properties of natroxalate mineral were determined. The calculated specific heat at 298.15 K is in excellent agreement with the experimental value, the difference being less than 1%. Since for most of these properties there are not experimental values to compare with, their values were predicted.

Maternal and genetic effects on broiler bone properties during incubation period.

PubMed

Yair, R; Cahaner, A; Uni, Z; Shahar, R

2017-07-01

In order to examine the differences in bone properties between fast-growing and slow-growing broiler embryos and to understand the effects of genotype and egg size on these differences, fast- and slow-growing hens and males were reciprocally crossed to create 4 egg groups: FST (laid by fast-growing hens, inseminated by fast-growing males), H-FST (fast-growing hens and slow-growing males), H-SLW (slow-growing hens and fast-growing males), and SLW (slow-growing hens and slow-growing males). Embryos (n = 8) from these 4 groups were sacrificed and weighed, and both tibiae were harvested on embryonic d (E) 17, 19, and 21. Left tibiae were tested for their whole-bone mechanical properties using a micromechanical device. Cortical bone structure and bone mineral density (BMD) were examined by micro-computed tomography of the left tibiae. Bone mineralization was evaluated by measuring BMD and ash content, while the rate and location of mineralization were evaluated by fluorochrome labeling. Osteoclastic activity and osteocyte density were evaluated by histological stains [TRAP (Tartrate resistant acid phosphatase) and H&E (Hematoxylin and Eosin), respectively]. Groups with larger eggs (FST and H-FST) had higher BW and tibia weight than groups with smaller eggs (SLW and H-SLW); however, they had a lower ratio of tibia weight to BW. Between groups with similar egg weight, stiffness, maximal load, and yield load of the bones were higher in the SLW than the H-SLW, while no differences were found between the FST and H-FST. Additionally, the tibiae of the SLW were stiffer and their osteocyte density higher than in the FST on E21 and their periosteal mineralization rate was higher between E19 and E21. No differences were found between the groups in cortical bone structure. This study demonstrates that faster growing hatchlings, especially those that hatch from relatively small eggs, have inferior bone mechanical properties in comparison to slower growing hatchlings, and suggests that fast-growing chicks hatching from small eggs are at a higher risk for developing bone pathologies. Accordingly, selection for increased egg size may lead to improved mechanical performance of the skeleton of fast-growing broilers. © 2017 Poultry Science Association Inc.

Bone Mineral Content and Density Among Female NCAA Division I Athletes Across the Competitive Season and Over a Multi-Year Time Frame.

PubMed

Stanforth, Dixie; Lu, Tao; Stults-Kolehmainen, Matthew A; Crim, Brittany N; Stanforth, Philip R

2016-10-01

Stanforth, D, Lu, T, Stults-Kolehmainen, MA, Crim, BN, and Stanforth, PR. Bone mineral content and density among female NCAA Division I athletes across the competitive season and over a multi-year time frame. J Strength Cond Res 30(10): 2828-2838, 2016-Longitudinal and cross-sectional bone mineral content (BMC) and bone mineral density (BMD) comparisons were made among impact and nonimpact sports. Female collegiate athletes, 18-23 years of age, from basketball (BB; n = 38), soccer (SOC; n = 47), swimming (SW; n = 52), track sprinters and jumpers (TR; n = 49), and volleyball (VB; n = 26) had BMC/BMD measures preseason and postseason over 3 years. Control groups of 85 college females, 18-24 years of age, who completed 2 tests 1-3 years apart and of 170 college females, 18-20 years of age, were used for the longitudinal and cross-sectional analyses, respectively. A restricted maximum likelihood linear mixed model regression analysis with a compound symmetric heterogeneous variance-covariance matrix structure was used for all analyses (p ≤ 0.05). Increases from year-1 preseason to year-3 postseason included the following: total BMC (3.3%), total BMD (1.4%), and spine BMD (4.5%) for BB; total BMC (1.5%) and leg BMD (1.2%) for SOC; arm (1.8%), leg (1.9%), and total BMD (5.7%) for SW; total BMC (2.0%), arm (1.7%), leg (2.3%), pelvis (3.4%), spine (6.0%), and total BMD (2.3%) for TR; and arm (4.1%), leg (2.0%), pelvis (2.0%), spine (2.0%), and total BMD (2.7%) for VB. Comparisons among sports determined that BB had higher BMC and BMD values than all other sports for all variables except spine and total BMD; BB, SOC, TR, and VB had higher total BMC (11-29%), leg BMD (13-20%), and total BMD (9-15%) than SW and CON, and there were few differences among SOC, TR, and VB. In conclusion, small, significant increases in many BMC and BMD measures occur during female athlete's collegiate careers. The BMC and BMD differences between impact and nonimpact sports are large compared with smaller differences within impact sports.

Linear Calibration of Radiographic Mineral Density Using Video-Digitizing Methods

NASA Technical Reports Server (NTRS)

Martin, R. Bruce; Papamichos, Thomas; Dannucci, Greg A.

1990-01-01

Radiographic images can provide quantitative as well as qualitative information if they are subjected to densitometric analysis. Using modem video-digitizing techniques, such densitometry can be readily accomplished using relatively inexpensive computer systems. However, such analyses are made more difficult by the fact that the density values read from the radiograph have a complex, nonlinear relationship to bone mineral content. This article derives the relationship between these variables from the nature of the intermediate physical processes, and presents a simple mathematical method for obtaining a linear calibration function using a step wedge or other standard.

Linear Calibration of Radiographic Mineral Density Using Video-Digitizing Methods

NASA Technical Reports Server (NTRS)

Martin, R. Bruce; Papamichos, Thomas; Dannucci, Greg A.

1990-01-01

Radiographic images can provide quantitative as well as qualitative information if they are subjected to densitometric analysis. Using modern video-digitizing techniques, such densitometry can be readily accomplished using relatively inexpensive computer systems. However, such analyses are made more difficult by the fact that the density values read from the radiograph have a complex, nonlinear relationship to bone mineral content. This article derives the relationship between these variables from the nature of the intermediate physical processes, and presents a simple mathematical method for obtaining a linear calibration function using a step wedge or other standard.

Weight loss and bone mineral density.

PubMed

Hunter, Gary R; Plaisance, Eric P; Fisher, Gordon

2014-10-01

Despite evidence that energy deficit produces multiple physiological and metabolic benefits, clinicians are often reluctant to prescribe weight loss in older individuals or those with low bone mineral density (BMD), fearing BMD will be decreased. Confusion exists concerning the effects that weight loss has on bone health. Bone density is more closely associated with lean mass than total body mass and fat mass. Although rapid or large weight loss is often associated with loss of bone density, slower or smaller weight loss is much less apt to adversely affect BMD, especially when it is accompanied with high intensity resistance and/or impact loading training. Maintenance of calcium and vitamin D intake seems to positively affect BMD during weight loss. Although dual energy X-ray absorptiometry is normally used to evaluate bone density, it may overestimate BMD loss following massive weight loss. Volumetric quantitative computed tomography may be more accurate for tracking bone density changes following large weight loss. Moderate weight loss does not necessarily compromise bone health, especially when exercise training is involved. Training strategies that include heavy resistance training and high impact loading that occur with jump training may be especially productive in maintaining, or even increasing bone density with weight loss.

Mineral Nutritional Yield and Nutrient Density of Locally Adapted Wheat Genotypes under Organic Production

PubMed Central

Moreira-Ascarrunz, Sergio Daniel; Larsson, Hans; Prieto-Linde, Maria Luisa; Johansson, Eva

2016-01-01

The aim of the present investigation was to investigate the nutritional yield, nutrient density, stability, and adaptability of organically produced wheat for sustainable and nutritional high value food production. This study evaluated the nutritional yield of four minerals (Fe, Zn, Cu, and Mg) in 19 wheat genotypes, selected as being locally adapted under organic agriculture conditions. The new metric of nutritional yield was calculated for each genotype and they were evaluated for stability using the Additive Main effects and Multiplicative Interaction (AMMI) stability analysis and for genotypic value, stability, and adaptability using the Best Linear Unbiased Prediction (BLUP procedure). The results indicated that there were genotypes suitable for production under organic agriculture conditions with satisfactory yields (>4000 kg·ha−1). Furthermore, these genotypes showed high nutritional yield and nutrient density for the four minerals studied. Additionally, since these genotypes were stable and adaptable over three environmentally different years, they were designated “balanced genotypes” for the four minerals and for the aforementioned characteristics. Selection and breeding of such “balanced genotypes” may offer an alternative to producing nutritious food under low-input agriculture conditions. Furthermore, the type of evaluation presented here may also be of interest for implementation in research conducted in developing countries, following the objectives of producing enough nutrients for a growing population. PMID:28231184

Dietary Strontium Increases Bone Mineral Density in Intact Zebrafish (Danio rerio): A Potential Model System for Bone Research

PubMed Central

Padgett-Vasquez, Steve; Garris, Heath W.; Nagy, Tim R.; D'Abramo, Louis R.; Watts, Stephen A.

2010-01-01

Abstract Zebrafish (Danio rerio) skeletal bone possesses properties similar to human bone, which suggests that they may be used as a model to study mineralization characteristics of the human Haversian system, as well as human bone diseases. One prerequisite for the use of zebrafish as an alternative osteoporotic bone model is to determine whether their bone displays functional plasticity similar to that observed in other bone models. Strontium citrate was supplemented into a laboratory-prepared diet (45% crude protein) to produce dietary strontium levels of 0%, 0.63%, 1.26%, 1.89%, and 2.43% and fed ad libitum twice daily for 12 weeks to 28-day-old intact zebrafish. Length was determined at 4-week intervals, and both weight and length were recorded at 12 weeks. At 12 weeks, seven zebrafish from each dietary level were analyzed for total bone mineral density by microcomputed tomography. Dietary strontium citrate supplementation significantly (p < 0.05) increased zebrafish whole-body and spinal column bone mineral density. In addition, trace amounts of strontium were incorporated into the scale matrix in those zebrafish that consumed strontium-supplemented diets. These findings suggest that zebrafish bone displays plasticity similar to that reported for other bone models (i.e., rat, mouse, and monkey) that received supplements of strontium compounds and zebrafish should be viewed as an increasingly valuable bone model. PMID:20874492

High Density Infill in Cracks and Protrusions from the Articular Calcified Cartilage in Osteoarthritis in Standardbred Horse Carpal Bones

PubMed Central

Laverty, Sheila; Lacourt, Mathieu; Gao, Chan; Henderson, Janet E.; Boyde, Alan

2015-01-01

We studied changes in articular calcified cartilage (ACC) and subchondral bone (SCB) in the third carpal bones (C3) of Standardbred racehorses with naturally-occurring repetitive loading-induced osteoarthritis (OA). Two osteochondral cores were harvested from dorsal sites from each of 15 post-mortem C3 and classified as control or as showing early or advanced OA changes from visual inspection. We re-examined X-ray micro-computed tomography (µCT) image sets for the presence of high-density mineral infill (HDMI) in ACC cracks and possible high-density mineralized protrusions (HDMP) from the ACC mineralizing (tidemark) front (MF) into hyaline articular cartilage (HAC). We hypothesized and we show that 20-µm µCT resolution in 10-mm diameter samples is sufficient to detect HDMI and HDMP: these are lost upon tissue decalcification for routine paraffin wax histology owing to their predominant mineral content. The findings show that µCT is sufficient to discover HDMI and HDMP, which were seen in 2/10 controls, 6/9 early OA and 8/10 advanced OA cases. This is the first report of HDMI and HDMP in the equine carpus and in the Standardbred breed and the first to rely solely on µCT. HDMP are a candidate cause for mechanical tissue destruction in OA. PMID:25927581

The effect of locally delivered recombinant human bone morphogenetic protein-2 with hydroxyapatite/tri-calcium phosphate on the biomechanical properties of bone in diabetes-related osteoporosis.

PubMed

Liporace, Frank A; Breitbart, Eric A; Yoon, Richard S; Doyle, Erin; Paglia, David N; Lin, Sheldon

2015-06-01

Recombinant human bone morphogenetic protein-2 (rhBMP-2) is particularly effective in improving osteogenesis in patients with diminished bone healing capabilities, such as individuals with type 1 diabetes mellitus (T1DM) who have impaired bone healing capabilities and increased risk of developing osteoporosis. This study measured the effects of rhBMP-2 treatment on osteogenesis by observing the dose-dependent effect of localized delivery of rhBMP-2 on biomechanical parameters of bone using a hydroxyapatite/tri-calcium phosphate (HA/TCP) carrier in a T1DM-related osteoporosis animal model. Two different doses of rhBMP-2 (LD low dose, HD high dose) with a HA/TCP carrier were injected into the femoral intramedullary canal of rats with T1DM-related osteoporosis. Two more diabetic rat groups were injected with saline alone and with HA/TCP carrier alone. Radiographs and micro-computed tomography were utilized for qualitative assessment of bone mineral density (BMD). Biomechanical testing occurred at 4- and 8-week time points; parameters tested included torque to failure, torsional rigidity, shear stress, and shear modulus. At the 4-week time point, the LD and HD groups both exhibited significantly higher BMD than controls; at the 8-week time point, the HD group exhibited significantly higher BMD than controls. Biomechanical testing revealed dose-dependent, higher trends in all parameters tested at the 4- and 8-week time points, with minimal significant differences. Groups treated with rhBMP-2 demonstrated improved bone mineral density at both 4 and 8 weeks compared to control saline groups, in addition to strong trends towards improvement of intrinsic and extrinsic biomechanical properties when compared to control groups. Data revealed trends toward dose-dependent increases in peak torque, torsional rigidity, shear stress, and shear modulus 4 weeks after rhBMP-2 treatment. Not applicable.

Interpretation of hip fracture patterns using areal bone mineral density in the proximal femur.

PubMed

Hey, Hwee Weng Dennis; Sng, Weizhong Jonathan; Lim, Joel Louis Zongwei; Tan, Chuen Seng; Gan, Alfred Tau Liang; Ng, Jun Han Charles; Kagda, Fareed H Y

2015-12-01

Bone mineral density scans are currently interpreted based on an average score of the entire proximal femur. Improvements in technology now allow us to measure bone density in specific regions of the proximal femur. The study attempts to explain the pathophysiology of neck of femur (NOF) and intertrochanteric/basi-cervical (IT) fractures by correlating areal BMD (aBMD) scores with fracture patterns, and explore possible predictors for these fracture patterns. This is a single institution retrospective study on all patients who underwent hip surgeries from June 2010 to August 2012. A total of 106 patients (44 IT/basi-cervical, 62 NOF fractures) were studied. The data retrieved include patient characteristics and aBMD scores measured at different regions of the contralateral hip within 1 month of the injury. Demographic and clinical characteristic differences between IT and NOF fractures were analyzed using Fisher's Exact test and two-sample t test. Relationship between aBMD scores and fracture patterns was assessed using multivariable regression modeling. After adjusted multivariable analysis, T-Troc and T-inter scores were significantly lower in intertrochanteric/basi-cervical fractures compared to neck of femur fractures (P = 0.022 and P = 0.026, respectively). Both intertrochanteric/basi-cervical fractures (mean T.Tot -1.99) and neck of femur fractures (mean T.Tot -1.64) were not found to be associated with a mean T.tot less than -2.5. However, the mean aBMD scores were consistently less than -2.5 for both intertrochanteric/basi-cervical fractures and neck of femur fractures. Gender and calcium intake at the time of injury were associated with specific hip fracture patterns (P = 0.002 and P = 0.011, respectively). Hip fracture patterns following low energy trauma may be influenced by the pattern of reduced bone density in different areas of the hip. Intertrochanteric/basi-cervical fractures were associated with significantly lower T-Troc and T-Inter scores compared to neck of femur fractures, suggesting that the fracture traversed through the areas with the lowest bone density in the proximal femur. In the absence of reduced T.Troc and T.Inter, neck of femur fractures occurred more commonly. T-Total scores may underestimate the severity of osteoporosis/osteopenia and measuring T-score at the neck of femur may better reflect the severity of osteoporosis and likelihood of a fragility fracture.

30 CFR 62.170 - Audiometric testing.

Code of Federal Regulations, 2013 CFR

2013-07-01

... audiometric testing of the miner's hearing sensitivity for the purpose of establishing a valid baseline... the miner's hearing sensitivity as the baseline audiogram if it meets the audiometric testing... the testing. (2) The mine operator must notify the miner to avoid high levels of noise for at least 14...

30 CFR 62.170 - Audiometric testing.

Code of Federal Regulations, 2014 CFR

2014-07-01

... audiometric testing of the miner's hearing sensitivity for the purpose of establishing a valid baseline... the miner's hearing sensitivity as the baseline audiogram if it meets the audiometric testing... the testing. (2) The mine operator must notify the miner to avoid high levels of noise for at least 14...

30 CFR 62.170 - Audiometric testing.

Code of Federal Regulations, 2010 CFR

2010-07-01

... audiometric testing of the miner's hearing sensitivity for the purpose of establishing a valid baseline... the miner's hearing sensitivity as the baseline audiogram if it meets the audiometric testing... the testing. (2) The mine operator must notify the miner to avoid high levels of noise for at least 14...

30 CFR 62.170 - Audiometric testing.

Code of Federal Regulations, 2011 CFR

2011-07-01

... audiometric testing of the miner's hearing sensitivity for the purpose of establishing a valid baseline... the miner's hearing sensitivity as the baseline audiogram if it meets the audiometric testing... the testing. (2) The mine operator must notify the miner to avoid high levels of noise for at least 14...

30 CFR 62.170 - Audiometric testing.

Code of Federal Regulations, 2012 CFR

2012-07-01

... audiometric testing of the miner's hearing sensitivity for the purpose of establishing a valid baseline... the miner's hearing sensitivity as the baseline audiogram if it meets the audiometric testing... the testing. (2) The mine operator must notify the miner to avoid high levels of noise for at least 14...

Prospective assessment of bone turnover and clinical bone diseases after allogeneic hematopoietic stem-cell transplantation.

PubMed

Petropoulou, Anna D; Porcher, Raphael; Herr, Andrée-Laure; Devergie, Agnès; Brentano, Thomas Funck; Ribaud, Patricia; Pinto, Fernando O; Rocha, Vanderson; Peffault de Latour, Régis; Orcel, Philippe; Socié, Gérard; Robin, Marie

2010-06-15

Bone complications after hematopoietic stem-cell transplantation (HSCT) are relatively frequent. Evaluation of biomarkers of bone turnover and dual energy x-ray absorptiometry (DEXA) are not known in this context. We prospectively evaluated bone mineral density, biomarkers of bone turnover, and the cumulative incidence of bone complications after allogeneic HSCT. One hundred forty-six patients were included. Bone mineral density was measured by DEXA 2-month and 1-year post-HSCT. The markers of bone turnover were serum C-telopeptide (C-TP), 5 tartrate-resistant acid phosphatase (bone resorption), and osteocalcin (bone formation) determined pre-HSCT and 2 months and 1 year thereafter. Potential association between osteoporosis at 2 months, osteoporotic fracture or avascular necrosis and, individual patient's characteristics and biologic markers were tested. C-TP was high before and 2 months after transplant. At 2 months, DEXA detected osteoporosis in more than half the patients tested. Male sex, median age less than or equal to 15 years, and abnormal C-TP before HSCT were risk factors significantly associated with osteoporosis. Three-year cumulative incidences of fractures and avascular necrosis were 8% and 11%, respectively. Children were at higher risk of fracture, whereas corticosteroid treatment duration was a significant risk factor for developing a clinical bone complication post-HSCT. Bone complications and osteoporosis are frequent after HSCT. Bone biologic markers and DEXA showed that subclinical bone abnormalities appeared early post-HSCT. The risk factors, age, gender, and C-TP easily available at the time of transplantation were identified. Biphosphonates should probably be given to patients with those risk factors.

Longitudinal change in bone mineral density in a population-based cohort of patients with inflammatory bowel disease.

PubMed

Targownik, Laura E; Leslie, William D; Carr, Rachel; Clara, Ian; Miller, Norine; Rogala, Linda; Graff, Lesley A; Walker, John R; Bernstein, Charles N

2012-11-01

Persons with inflammatory bowel disease (IBD) are reported to have a high prevalence of osteoporosis and reduced bone mineral density (BMD) and to be at higher risk of fracture. The course of BMD loss over time is poorly characterized in persons with IBD. Eighty-six persons, stratified by age, were enrolled from a population-based longitudinal IBD cohort study to undergo BMD testing at baseline, with final BMD testing a mean of 4.3 years later. The proportion of subjects with significant change in BMD at the lumbar spine, total hip, and femoral neck was assessed, as were clinical, biochemical, and anthropomorphic changes. Vertebral radiographs were also obtained at baseline and at the end of follow-up in those aged 50 years and above to detect vertebral fractures. The change in BMD seen in this cohort of IBD patients was similar to the expected rate of BMD loss in the general population. Age >50 years, decreasing body mass index (BMI), and corticosteroid use were most notably correlated with BMD loss. Subjects aged <50 years did not have statistically significant declines in BMD. IBD symptom activity scores correlated poorly with BMD loss. Vertebral fractures were uncommon, with only two subjects out of 41 >50 years old developing a definite radiographic fracture over the course of follow-up. No major nonvertebral fractures were observed. Patients with IBD do not appear to have significantly accelerated BMD loss. Older age, decreasing BMI, and corticosteroid use may identify IBD patients at greater risk for BMD loss.

The relationship between proton pump inhibitor use and longitudinal change in bone mineral density: a population-based study [corrected] from the Canadian Multicentre Osteoporosis Study (CaMos).

PubMed

Targownik, Laura E; Leslie, William D; Davison, K Shawn; Goltzman, David; Jamal, Sophie A; Kreiger, Nancy; Josse, Robert G; Kaiser, Stephanie M; Kovacs, Christopher S; Prior, Jerilynn C; Zhou, Wei

2012-09-01

Proton pump inhibitor (PPI) use has been identified as a risk factor for hip and vertebral fractures. Evidence supporting a relationship between PPI use and osteoporosis remains scant. Demonstrating that PPIs are associated with accelerated bone mineral density (BMD) loss would provide supportive evidence for a mechanism through which PPIs could increase fracture risk. We used the Canadian Multicentre Osteoporosis Study data set, which enrolled a population-based sample of Canadians who underwent BMD testing of the femoral neck, total hip, and lumbar spine (L1-L4) at baseline, and then again at 5 and 10 years. Participants also reported drug use and exposure to risk factors for osteoporosis and fracture. Multivariate linear regression was used to determine the independent association of PPI exposure and baseline BMD, and on change in BMD at 5 and 10 years. In all, 8,340 subjects were included in the baseline analysis, with 4,512 (55%) undergoing year 10 BMD testing. After adjusting for potential confounders, PPI use was associated with significantly lower baseline BMD at the femoral neck and total hip. PPI use was not associated with a significant acceleration in covariate-adjusted BMD loss at any measurement site after 5 and 10 years of follow-up. PPI users had lower BMD at baseline than PPI non-users, but PPI use over 10 years did not appear to be associated with accelerated BMD loss. The reasons for discordant findings between PPI use at baseline and during follow-up require further study.

A high-fat diet can affect bone healing in growing rats.

PubMed

Yamanaka, Jéssica Suzuki; Yanagihara, Gabriela Rezende; Carlos, Bruna Leonel; Ramos, Júnia; Brancaleon, Brígida Batista; Macedo, Ana Paula; Issa, João Paulo Mardegan; Shimano, Antônio Carlos

2018-05-01

A high-fat diet (HFD) can have a negative effect on bone quality in young and old people. Although bone healing in children is normally efficient, there is no evidence that children who have a diet rich in fat have compromised bone fracture regeneration compared with children with recommended dietary fat levels. The purpose of the present study was to evaluate the effects of an HFD on bone healing in growing female rats. Twenty-six postweaning female Wistar rats were divided into two groups (13 animals per group): a standard diet (SD) group and an HFD (with 60% of energy from fat) group. The rats received the assigned diets for 5 weeks, and in the third week they were submitted to an osteotomy procedure of the left tibia. Body mass and feed intake were recorded during the experiment. One day before euthanasia, an insulin tolerance test was performed. After euthanasia, the tibiae were removed and analyzed by densitometry, mechanical testing, histomorphometry, stereology and immunohistochemistry. An HFD caused an adaptive response to maintain energetic balance by decreasing feed intake and causing insulin insensitivity. There was no change in bone mineral density, collagen amount and immunostaining for bone formation, but maximal load and stiffness were decreased in the HFD group. In addition, bone volume had a tendency to be higher in the SD group than in the HFD group. Compared with rats receiving an SD, growing rats receiving an HFD for 5 weeks had similar bone mineral density but altered mechanical properties at the osteotomy defect site.

No impact of disease and its treatment on bone mineral density in survivors of childhood acute lymphoblastic leukemia.

PubMed

Jain, Silky; Jain, Sandeep; Kapoor, Gauri; Virmani, Anju; Bajpai, Ram

2017-04-01

Acute lymphoblastic leukemia (ALL) and its treatment are often implicated in adversely affecting bone health. Conflicting reports in the literature and a paucity of studies from the developing world prompted us to study bone mineral density (BMD) in childhood ALL survivors. BMD lumbar spine (LS) and whole body (WB) were evaluated, using dual energy x-ray absorptiometry in 65 pediatric ALL survivors who had been off-therapy for at least 2 years. The control group constituted of 50 age- and sex-matched healthy siblings. Kernel density plots were used to compare BMD among cases and controls. The disease-, treatment-, hormone- and lifestyle-related factors likely to modulate BMD were analyzed using the Mann-Whitney U test and Student's t-test. At a median of 4.3 years (range, 2-14.8 years) since cessation of therapy, height-adjusted (HA) mean BMD Z-scores of LS (-0.67 ± 1.11, -0.607 ± 1.05, P = 0.759) and WB (-0.842 ± 0.92, -0.513 ± 0.97, P = 0.627) were comparable among the cases and controls. Disease, treatment (chemotherapy, cranial radiotherapy) and endocrine factors did not predict low BMD. However, survivors with calcium intake <800 mg/day (WB, P = 0.018) and hypovitaminosis D (≤25 nmol/L) had lower BMD values (HA-WB, P = 0.046) than the controls. A significant proportion of survivors were overweight or obese and had higher BMD Z-scores (HA-LS, P = 0.003; HA-WB, P = 0.028). BMD Z-scores were similar among ALL survivors and controls. It was reassuring that there was no detrimental impact of the disease or its treatment on BMD. Future studies are required to determine the best possible ways to target the modifiable risk factors (diet, vitamin D) to optimize bone health. © 2016 Wiley Periodicals, Inc.

A multinational study to develop universal standardization of whole-body bone density and composition using GE Healthcare Lunar and Hologic DXA systems.

PubMed

Shepherd, John A; Fan, Bo; Lu, Ying; Wu, Xiao P; Wacker, Wynn K; Ergun, David L; Levine, Michael A

2012-10-01

Dual-energy x-ray absorptiometry (DXA) is used to assess bone mineral density (BMD) and body composition, but measurements vary among instruments from different manufacturers. We sought to develop cross-calibration equations for whole-body bone density and composition derived using GE Healthcare Lunar and Hologic DXA systems. This multinational study recruited 199 adult and pediatric participants from a site in the US (n = 40, ages 6 through 16 years) and one in China (n = 159, ages 5 through 81 years). The mean age of the participants was 44.2 years. Each participant was scanned on both GE Healthcare Lunar and Hologic Discovery or Delphi DXA systems on the same day (US) or within 1 week (China) and all scans were centrally analyzed by a single technologist using GE Healthcare Lunar Encore version 14.0 and Hologic Apex version 3.0. Paired t-tests were used to test the results differences between the systems. Multiple regression and Deming regressions were used to derive the cross-conversion equations between the GE Healthcare Lunar and Hologic whole-body scans. Bone and soft tissue measures were highly correlated between the GE Healthcare Lunar and Hologic and systems, with r ranging from 0.96 percent fat [PFAT] to 0.98 (BMC). Significant differences were found between the two systems, with average absolute differences for PFAT, BMC, and BMD of 1.4%, 176.8 g and 0.013 g/cm(2) , respectively. After cross-calibration, no significant differences remained between GE Healthcare Lunar measured results and the results converted from Hologic. The equations we derived reduce differences between BMD and body composition as determined by GE Healthcare Lunar and Hologic systems and will facilitate combining study results in clinical or epidemiological studies. Copyright © 2012 American Society for Bone and Mineral Research.

Autoradiographic method for quantitation of deposition and distribution of radiocalcium in bone

PubMed Central

Lawrence Riggs, B; Bassingthwaighte, James B.; Jowsey, Jenifer; Peter Pequegnat, E

2010-01-01

A method is described for quantitating autoradiographs of bone-seeking isotopes in microscopic sections of bone. Autoradiographs of bone sections containing 45Ca and internal calibration standards are automatically scanned with a microdensitometer. The digitized optical density output is stored on magnetic tape and is converted by computer to equivalent activity of 45Ca per gram of bone. The computer determines the total 45Ca uptake in the bone section and, on the basis of optical density and anatomic position, quantitatively divides the uptake into 4 components, each representing a separate physiologic process (bone formation, secondary mineralization, diffuse long-term exchange, and surface short-term exchange). The method is also applicable for quantitative analysis of microradiographs of bone sections for mineral content and density. PMID:5416906

Seismic velocities - density relationship for the Earth's crust: effects of chemical compositions, amount of water, and implications on gravity and topography

NASA Astrophysics Data System (ADS)

Guerri, Mattia; Cammarano, Fabio

2014-05-01

Seismic velocities - density relationship for the Earth's crust: effects of chemical compositions, amount of water, and implications on gravity and topography Mattia Guerri and Fabio Cammarano Department of Geosciences and Natural Resource Management, Section of Geology, University of Copenhagen, Denmark. A good knowledge of the Earth's crust is not only important to understand its formation and dynamics, but also essential to infer mantle seismic structure, dynamic topography and location of seismic events. Global and local crustal models available (Bassin et al., 2000; Nataf & Ricard, 1996; Molinari & Morelli, 2011) are based on VP-density empirical relationships that do not fully exploit our knowledge on mineral phases forming crustal rocks and their compositions. We assess the effects of various average crustal chemical compositions on the conversion from seismic velocities to density, also testing the influence of water. We consider mineralogies at thermodynamic equilibrium and reference mineral assemblages at given P-T conditions to account for metastability. Stable mineral phases at equilibrium have been computed with the revised Holland and Powell (2002) EOS and thermodynamic database implemented in PerpleX (Connolly 2005). We have computed models of physical properties for the crust following two approaches, i) calculation of seismic velocities and density by assuming the same layers structure of the model CRUST 2.0 (Bassin et al., 2000) and a 3-D thermal structure based on heat-flow measurements; ii) interpretation of the Vp model reported in CRUST 2.0 to obtain density and shear wave velocity for the crustal layers, using the Vp-density relations obtained with the thermodynamic modeling. The obtained density models and CRUST 2.0 one have been used to calculate isostatic topography and gravity field. Our main results consist in, i) phase transitions have a strong effect on the physical properties of crustal rocks, in particular on seismic velocities; ii) models based on different crustal chemical compositions show strong variations on both seismic properties and density; iii) the amount of water is a main factor in determining the physical properties of crustal rocks, drastically changing the phase stability in the mineralogical assemblages; iii) the differences between the various density models that we obtained, and the variations between them and CRUST2.0, translate into strong effects for the calculated isostatic topography and gravity field. Our approach, dealing directly with chemical compositions, is suitable to quantitatively investigate compositional heterogeneity in the Earth's crust. References - Bassin, C., Laske, G. & Masters, G., 2000. The current limits of resolution for surface wave tomography in North America, EOS, Trans. Am. Geophys. Un., 81, F897. - Nataf, H. & Ricard, Y., 1996. 3SMAC: an a priori tomographic model of the upper mantle based on geophysical modeling, Phys. Earth planet. Inter., 95(1-2), 101-122. - Molinari, I. & Morelli, A., 2011. Epcrust: a reference crustal model for the European Plate, Gepohys. J. Int., 185, 352-364. - Connolly JAD (2005) Computation of phase equilibria by linear programming: a tool for geodynamic modeling and its application to subduction zone decarbonation. Earth and Planetary Science Letters 236:524-541.

Magnesium metabolism in 4-year-old to 8-year-old children

USDA-ARS?s Scientific Manuscript database

Magnesium (Mg) is a key factor in bone health, but few studies have evaluated Mg intake or absorption and their relationship with bone mineral content (BMC) or bone mineral density (BMD) in children. We measured Mg intake, absorption, and urinary excretion in a group of children 4 to 8 years of age....

Settling equivalence of detrital minerals and grain-size dependence of sediment composition

NASA Astrophysics Data System (ADS)

Garzanti, Eduardo; Andò, Sergio; Vezzoli, Giovanni

2008-08-01

This study discusses the laws which govern sediment deposition, and consequently determine size-dependent compositional variability. A theoretical approach is substantiated by robust datasets on major Alpine, Himalayan, and African sedimentary systems. Integrated (bulk-petrography, heavy-mineral, X-ray powder diffraction) multiple-window analyses at 0.25ϕ to 0.50ϕ sieve interval of eighty-five fluvial, beach, and eolian-dune samples, ranging from very fine silt to coarse sand, document homologous intrasample compositional trends, revealed by systematic concentration of denser grains in finer-grained fractions (“size-density sorting”). These trends are explained by the settling-equivalence principle, stating that detrital minerals are deposited together if their settling velocity is the same. Settling of silt is chiefly resisted by fluid viscosity, and Stokes' law predicts that size differences between detrital minerals in ϕ units (“size shifts”) are half the difference between the logarithms of their submerged densities. Settling of pebbles is chiefly resisted by turbulence effects, and the Impact law predicts double size shifts than Stokes' law. Settling of sand is resisted by both viscosity and turbulence, the settling-equivalence formula is complex, and size shifts increase - with increasing settling velocity and grain size - from those predicted by Stokes' law to those predicted by the Impact law. In wind-laid sands, size shifts match those predicted by the Impact law; size-density sorting is thus greater than in water-laid fine sands. New analytical, graphical, and statistical techniques for rigorous settling-equivalence analysis of terrigenous sediments are illustrated. Deviations associated with non-spherical shape, density anomalies, inheritance from source rocks, or mixing of detrital species with contrasting provenance and different size distribution are also tentatively assessed. Such integrated theoretical and experimental approach allows us to mathematically predict intrasample compositional variability of water-laid and wind-laid sediments, once the density of detrital components is known.

Community water fluoridation, bone mineral density, and fractures: prospective study of effects in older women.

PubMed

Phipps, K R; Orwoll, E S; Mason, J D; Cauley, J A

2000-10-07

To determine whether fluoridation influences bone mineral density and fractures in older women. Multicentre prospective study on risk factors for osteoporosis and fractures. Four community based centres in the United States. 9704 ambulatory women without bilateral hip replacements enrolled during 1986-8; 7129 provided information on exposure to fluoride. Bone mineral density of the lumbar spine, proximal femur, radius, and calcaneus plus incident fractures (fractures that occurred during the study) of vertebrae, hip, wrist, and humerus. Women were classified as exposed or not exposed or having unknown exposure to fluoride for each year from 1950 to 1994. Outcomes were compared in women with continuous exposure to fluoridated water for the past 20 years (n=3218) and women with no exposure during the past 20 years (n=2563). In women with continuous exposure mean bone mineral density was 2.6% higher at the femoral neck (0.017 g/cm(2), P<0.001), 2.5% higher at the lumbar spine (0.022 g/cm(2), P<0.001), and 1.9% lower at the distal radius (0.007 g/cm(2), P=0.002). In women with continuous exposure the multivariable adjusted risk of hip fracture was slightly reduced (risk ratio 0.69, 95% confidence interval 0.50 to 0.96, P=0.028) as was the risk of vertebral fracture (0.73, 0.55 to 0.97, P=0.033). There was a non-significant trend toward an increased risk of wrist fracture (1.32, 1.00 to 1.71, P=0.051) and no difference in risk of humerus fracture (0.85, 0.58 to 1.23, P=0.378). Long term exposure to fluoridated drinking water does not increase the risk of fracture.

Community water fluoridation, bone mineral density, and fractures: prospective study of effects in older women

PubMed Central

Phipps, Kathy R; Orwoll, Eric S; Mason, Jill D; Cauley, Jane A

2000-01-01

Objective To determine whether fluoridation influences bone mineral density and fractures in older women. Design Multicentre prospective study on risk factors for osteoporosis and fractures. Setting Four community based centres in the United States. Participants 9704 ambulatory women without bilateral hip replacements enrolled during 1986-8; 7129 provided information on exposure to fluoride. Main outcome measures Bone mineral density of the lumbar spine, proximal femur, radius, and calcaneus plus incident fractures (fractures that occurred during the study) of vertebrae, hip, wrist, and humerus. Results Women were classified as exposed or not exposed or having unknown exposure to fluoride for each year from 1950 to 1994. Outcomes were compared in women with continuous exposure to fluoridated water for the past 20 years (n=3218) and women with no exposure during the past 20 years (n=2563). In women with continuous exposure mean bone mineral density was 2.6% higher at the femoral neck (0.017 g/cm2, P<0.001), 2.5% higher at the lumbar spine (0.022 g/cm2, P<0.001), and 1.9% lower at the distal radius (0.007 g/cm2, P=0.002). In women with continuous exposure the multivariable adjusted risk of hip fracture was slightly reduced (risk ratio 0.69, 95% confidence interval 0.50 to 0.96, P=0.028) as was the risk of vertebral fracture (0.73, 0.55 to 0.97, P=0.033). There was a non-significant trend toward an increased risk of wrist fracture (1.32, 1.00 to 1.71, P=0.051) and no difference in risk of humerus fracture (0.85, 0.58 to 1.23, P=0.378). Conclusions Long term exposure to fluoridated drinking water does not increase the risk of fracture. PMID:11021862

High-Dose α-Tocopherol Supplementation Does Not Induce Bone Loss in Normal Rats

PubMed Central

Kasai, Shunji; Ito, Akemi; Shindo, Kaori; Toyoshi, Tohru; Bando, Masahiro

2015-01-01

Oxidative stress affects bone turnover. Preventative effects of antioxidants such as vitamin E on reduced bone mineral density and fractures associated with aging, osteoporosis, and smoking have been examined in animals and humans. The effects of vitamin E (α-tocopherol; αT) on bone health have yielded conflicting and inconclusive results from animal studies. In this study, to determine the bone effects of αT, we investigated the in vivo effects of αT on the bone mineral density, bone mass, bone microstructure, bone resorption, and osteogenesis through peripheral quantitative computed tomography (pQCT) measurements, micro-computed tomography (micro-CT) analyses, and bone histomorphometry of lumbar vertebrae and femurs in normal female Wistar rats fed diets containing αT in different quantities (0, 30, 120, or 600 mg/kg diet) for 8 weeks. To validate our hypotheses regarding bone changes, we examined ovariectomized rats as an osteoporosis model and control sham-operated rats in parallel. As expected, ovariectomized rats had reduced bone mineral density in lumbar vertebrae and the distal metaphyses of their femurs, reduced bone mass and deteriorated microstructure of cancellous bones in the vertebral body and distal femur metaphyses, and reduced bone mass due to resorption-dominant enhanced bone turnover in secondary cancellous bones in these sites. In comparison, αT administered to normal rats, even at the highest dose, did not induce reduced bone mineral density of lumbar vertebrae and femurs or a reduced bone mass or fragile microstructure of cancellous bones of the vertebral body and distal femur metaphyses. Instead, αT-fed rats showed a tendency for an osteogenesis-dominant bone mass increase in secondary cancellous bones in the vertebral body, in which active bone remodeling occurs. Thus, αT consumption may have beneficial effects on bone health. PMID:26147575

Genetic randomization reveals functional relationships among morphologic and tissue-quality traits that contribute to bone strength and fragility

PubMed Central

Hu, Bin; Tommasini, Steven M.; Courtland, Hayden-William; Price, Christopher; Terranova, Carl J.; Nadeau, Joseph H.

2007-01-01

We examined femora from adult AXB/BXA recombinant inbred (RI) mouse strains to identify skeletal traits that are functionally related and to determine how functional interactions among these traits contribute to genetic variability in whole-bone stiffness, strength, and toughness. Randomization of A/J and C57BL/6J genomic regions resulted in each adult male and female RI strain building mechanically functional femora by assembling unique sets of morphologic and tissue-quality traits. A correlation analysis was conducted using the mean trait values for each RI strain. A third of the 66 correlations examined were significant, indicating that many bone traits covaried or were functionally related. Path analysis revealed important functional interactions among bone slenderness, cortical thickness, and tissue mineral density. The path coefficients describing these functional relations were similar for both sexes. The causal relationship among these three traits suggested that cellular processes during growth simultaneously regulate bone slenderness, cortical thickness, and tissue mineral density so that the combination of traits is sufficiently stiff and strong to satisfy daily loading demands. A disadvantage of these functional interactions was that increases in tissue mineral density also deleteriously affected tissue ductility. Consequently, slender bones with high mineral density may be stiff and strong but they are also brittle. Thus, genetically randomized mouse strains revealed a basic biological paradigm that allows for flexibility in building bones that are functional for daily activities but that creates preferred sets of traits under extreme loading conditions. Genetic or environmental perturbations that alter these functional interactions during growth would be expected to lead to loss of function and suboptimal adult bone quality. PMID:17557179

Bone mineral density in developing children with osteogenesis imperfecta

PubMed Central

Sakkers, Ralph J B; Pruijs, Hans E H; Joosse, Pieter; Castelein, René M

2013-01-01

Background and purpose — Osteogenesis imperfecta (OI) is a heritable disorder of connective tissue caused by a defect in collagen type I synthesis. For bone, this includes fragility, low bone mass, and progressive skeletal deformities, which can result in various degrees of short stature. The purpose of this study was to investigate development of bone mineral density in children with OI. Patients and methods — Development of lumbar bone mineral density was studied retrospectively in a cohort of 74 children with OI. Mean age was 16.3 years (SD 4.3). In 52 children, repeated measurements were available. Mean age at the start of measurement was 8.8 years (SD 4.1), and mean follow-up was 9 years (SD 2.7). A longitudinal data analysis was performed. In the total cohort (74 children), a cross-sectional analysis was performed with the latest-measured BMD. Age at the latest BMD measurement was almost equal for girls and boys: 17.4 and 17.7 years respectively. Result — Mean annual increase in BMD in the 52 children was 0.038 g/cm2/year (SD 0.024). Annual increase in BMD was statistically significantly higher in girls, in both the unadjusted and adjusted analysis. In cross-sectional analysis, in the whole cohort the latest-measured lumbar BMD was significantly higher in girls, in the children with OI of type I, in walkers, and in those who were older, in both unadjusted and adjusted analysis. Interpretation — During 9 years of follow-up, there appeared to be an increase in bone mineral density, which was most pronounced in girls. One possible explanation might be a later growth spurt and older age at peak bone mass in boys. PMID:23992144

Osteoporosis, bone mineral density and CKD-MBD complex (I): Diagnostic considerations.

PubMed

Bover, Jordi; Ureña-Torres, Pablo; Torregrosa, Josep-Vicent; Rodríguez-García, Minerva; Castro-Alonso, Cristina; Górriz, José Luis; Laiz Alonso, Ana María; Cigarrán, Secundino; Benito, Silvia; López-Báez, Víctor; Lloret Cora, María Jesús; daSilva, Iara; Cannata-Andía, Jorge

2018-04-24

Osteoporosis (OP) and chronic kidney disease (CKD) independently influence bone and cardiovascular health. A considerable number of patients with CKD, especially those with stages 3a to 5D, have a significantly reduced bone mineral density leading to a high risk of fracture and a significant increase in associated morbidity and mortality. Independently of classic OP related to age and/or gender, the mechanical properties of bone are also affected by inherent risk factors for CKD ("uraemic OP"). In the first part of this review, we will analyse the general concepts regarding bone mineral density, OP and fractures, which have been largely undervalued until now by nephrologists due to the lack of evidence and diagnostic difficulties in the context of CKD. It has now been proven that a reduced bone mineral density is highly predictive of fracture risk in CKD patients, although it does not allow a distinction to be made between the causes which generate it (hyperparathyroidism, adynamic bone disease and/or senile osteoporosis, etc.). Therefore, in the second part, we will analyse the therapeutic indications in different CKD stages. In any case, the individual assessment of factors which represent a higher or lower risk of fracture, the quantification of this risk (i.e. using tools such as FRAX ® ) and the potential indications for densitometry in patients with CKD could represent an important first step pending new clinical guidelines based on randomised studies which do not exclude CKD patients, all the while avoiding therapeutic nihilism in an area of growing importance. Copyright © 2018 Sociedad Española de Nefrología. Published by Elsevier España, S.L.U. All rights reserved.

Thyroid Dysfunction in an Adult Female Population: A population-based study of Latin American Vertebral Osteoporosis Study (LAVOS) - Puerto Rico Site Hypothyroidism in LAVOS-Puerto Rico site

PubMed Central

González-Rodríguez, Loida A.; Felici-Giovanini, Marcos E; Haddock, Lillian

2013-01-01

Objective To determine the prevalence of hypothyroidism in an adult female population in Puerto Rico and to determine the relationship between hypothyroidism, bone mineral density and vertebral and non-vertebral fractures in this population. Methods Data from the 400 subjects database of the Latin American Vertebral Osteoporosis Study (LAVOS), Puerto Rico site was reviewed. Patient’s medical history, anthropometric data, current medications, laboratories, and DXA results was extracted. Subjects with thyroid dysfunction were identified based on their previous medical history and levels of TSH. Bone Mineral Density was classified using the World Health Organization criteria. Crude prevalence of thyroid dysfunction were estimated with a confidence of 95% and weighted by the population distribution by age, according to the distribution by age group in the 2000 census. Bone mineral densities and prevalence of vertebral and non-vertebral fractures were compared among the groups. Results The weighted prevalence of hyperthyroidism in this population was 0.0043% (95% CI: −0.0021%, 0.0107%). The weighted prevalence of hypothyroidism was 24.2% (95% CI: 19.9%, 28.4%). Increased prevalence of hypothyroidism was found in participants 70 years or older. The mean BMD at spine, hip and femoral neck was similar among the groups. No difference in the proportion of participants with vertebral and non-vertebral fractures was found among the groups. Conclusion Our study found a high prevalence of hypothyroidism among adult postmenopausal females in Puerto Rico. No association between hypothyroidism and decreased bone mineral densities, vertebral or non-vertebral fractures was found in this population. PMID:23781620

Hip fracture in the elderly: a re-analysis of the EPIDOS study with causal Bayesian networks.

PubMed

Caillet, Pascal; Klemm, Sarah; Ducher, Michel; Aussem, Alexandre; Schott, Anne-Marie

2015-01-01

Hip fractures commonly result in permanent disability, institutionalization or death in elderly. Existing hip-fracture predicting tools are underused in clinical practice, partly due to their lack of intuitive interpretation. By use of a graphical layer, Bayesian network models could increase the attractiveness of fracture prediction tools. Our aim was to study the potential contribution of a causal Bayesian network in this clinical setting. A logistic regression was performed as a standard control approach to check the robustness of the causal Bayesian network approach. EPIDOS is a multicenter study, conducted in an ambulatory care setting in five French cities between 1992 and 1996 and updated in 2010. The study included 7598 women aged 75 years or older, in which fractures were assessed quarterly during 4 years. A causal Bayesian network and a logistic regression were performed on EPIDOS data to describe major variables involved in hip fractures occurrences. Both models had similar association estimations and predictive performances. They detected gait speed and mineral bone density as variables the most involved in the fracture process. The causal Bayesian network showed that gait speed and bone mineral density were directly connected to fracture and seem to mediate the influence of all the other variables included in our model. The logistic regression approach detected multiple interactions involving psychotropic drug use, age and bone mineral density. Both approaches retrieved similar variables as predictors of hip fractures. However, Bayesian network highlighted the whole web of relation between the variables involved in the analysis, suggesting a possible mechanism leading to hip fracture. According to the latter results, intervention focusing concomitantly on gait speed and bone mineral density may be necessary for an optimal prevention of hip fracture occurrence in elderly people.

Leaching behavior of rare earth elements in fort union lignite coals of North America

DOE PAGES

Laudal, Daniel A.; Benson, Steven A.; Addleman, Raymond Shane; ...

2018-03-30

Fort Union lignite coal samples were subjected to a series of aqueous leaching experiments to understand the extraction behavior of the rare earth elements (REE). This testing was aimed at understanding the modes of occurrence of the REE in the lignite coals, as well as to provide foundational data for development of rare earth extraction processes. In a first series of tests, a sequential leaching process was used to investigate modes of occurrence of the REE of select lignite coals. The tests involved sequential exposure to solvents consisting of water, ammonium acetate and dilute hydrochloric acid (HCl). The results indicatedmore » that water and ammonium acetate extracted very little of the REE, indicating the REE are not present as water soluble or ion-exchangeable forms. However, the data shows that a large percentage of the REE were extracted with the hydrochloric acid (80–95 wt%), suggesting presence in HCl-soluble mineral forms such as carbonates, and/or presence as organic complexes. A second series of tests was performed involving single-step leaching with dilute acids and various operating parameters, including acid type, acid concentration, acid/coal contact time and coal particle size. For select samples, additional tests were performed to understand the results of leaching, including float-sink density separations and humic acid extraction. The results have shown that the majority of REE in Fort Union lignites appear to be associated weakly with the organic matrix of the coals, most likely as coordination complexes of carboxylic acid groups. The light REE and heavy REE exhibit different behaviors, however. The extractable light REE appear to have association both in acid-soluble mineral forms and as organic complexes, whereas the extractable heavy REE appear to be almost solely associated with the organics. In conclusion, scandium behavior was notably different than yttrium and the lanthanides, and the data suggests the extractable content is primarily associated as acid-soluble mineral forms.« less

Leaching behavior of rare earth elements in fort union lignite coals of North America

DOE Office of Scientific and Technical Information (OSTI.GOV)

Laudal, Daniel A.; Benson, Steven A.; Addleman, Raymond Shane

Fort Union lignite coal samples were subjected to a series of aqueous leaching experiments to understand the extraction behavior of the rare earth elements (REE). This testing was aimed at understanding the modes of occurrence of the REE in the lignite coals, as well as to provide foundational data for development of rare earth extraction processes. In a first series of tests, a sequential leaching process was used to investigate modes of occurrence of the REE of select lignite coals. The tests involved sequential exposure to solvents consisting of water, ammonium acetate and dilute hydrochloric acid (HCl). The results indicatedmore » that water and ammonium acetate extracted very little of the REE, indicating the REE are not present as water soluble or ion-exchangeable forms. However, the data shows that a large percentage of the REE were extracted with the hydrochloric acid (80–95 wt%), suggesting presence in HCl-soluble mineral forms such as carbonates, and/or presence as organic complexes. A second series of tests was performed involving single-step leaching with dilute acids and various operating parameters, including acid type, acid concentration, acid/coal contact time and coal particle size. For select samples, additional tests were performed to understand the results of leaching, including float-sink density separations and humic acid extraction. The results have shown that the majority of REE in Fort Union lignites appear to be associated weakly with the organic matrix of the coals, most likely as coordination complexes of carboxylic acid groups. The light REE and heavy REE exhibit different behaviors, however. The extractable light REE appear to have association both in acid-soluble mineral forms and as organic complexes, whereas the extractable heavy REE appear to be almost solely associated with the organics. In conclusion, scandium behavior was notably different than yttrium and the lanthanides, and the data suggests the extractable content is primarily associated as acid-soluble mineral forms.« less

Decoupling the deep: crop rotations, fertilization and soil physico-chemical properties down the profile

NASA Astrophysics Data System (ADS)

Hobley, Eleanor; Honermeier, Bernd; Don, Axel; Amelung, Wulf; Kögel-Knabner, Ingrid

2017-04-01

Crop fertilization provides vital plant nutrients (e.g. NPK) to ensure yield security but is also associated with negative environmental impacts. In particular, inorganic, mineral nitrogen (Nmin) fertilization leads to emissions during its energy intensive production as well as Nmin leaching to receiving waters. Incorporating legumes into crop rotations can provide organic N to the soil and subsequent crops, reducing the need for mineral N fertilizer and its negative environmental impacts. An added bonus is the potential to enhance soil organic carbon stocks, thereby reducing atmospheric CO2 concentrations. In this study we assessed the effects of legumes in rotation and fertilization regimes on the depth distribution - down to 1 m - of total soil nitrogen (Ntot), soil organic carbon (SOC) as well as isotopic composition (δ13C, δ15N), electrical conductivity and bulk density as well as agricultural yields at a long-term field experiment in Gießen, Germany. Fertilization had significant but small impacts on the soil chemical environment, most particularly the salt content of the soil, with PK fertilization increasing electrical conductivity throughout the soil profile. Similarly, fertilization resulted in a small reduction of soil pH throughout the soil profile. N fertilization, in particular, significantly increased yields, whereas PK fertilizer had only marginal yield effects, indicating that these systems are N limited. This N limitation was confirmed by significant yield benefits with leguminous crops in rotation, even in combination with mineral N fertilizer. The soil was physically and chemically influenced by the choice of crop rotation. Adding clover as a green mulch crop once every 4 years resulted in an enrichment of total N and SOC at the surface compared with fava beans and maize, but only in combination with PK fertilization. In contrast, fava beans and to a lesser extent maize in rotation lowered bulk densities in the subsoil compared with clover. This resulted in a reduction of N density at depth, which was not mirrored in C densities, indicating that fava beans decouple C and N cycles in the deep soil profile. We then tested whether these effects are a result of plant (i.e. enhanced rooting depth associated with lowered subsoil bulk density) or microbial (i.e. N-cycling and denitrification processes) activities, by investigating the isotopic signatures of C and N down the profile. Our results indicate that the selection of crop rotation influences soil C and N cycling and depth distribution. Although mineral N fertilizer has significant benefits for yield, the choice of crop rotation has a greater influence on soil C and N cycling and specifically the addition of leguminous plants into rotation can provide additional yield benefits and stability. Incorporating legumes into crop rotations affects soil physical and chemical properties and decouples C and N cycles in the deep soil profile, indicating different nutrient and water cycling processes in the deep soil profile.

Holographic Lens for Pilot’s Head-Up Display

DTIC Science & Technology

1975-04-01

in fringe stability. A 5 ft x 9 ft x 40 in. high acoustical enclosure, constructed with six lb/ft3 mineral wool sand- wiched between a solid 24 gauge...VIBRATION ISOLATION A 5 ft x 9 ft x 40 in. high acoustic enclosure, consisting of 6 lb. /ft 3 mineral wool sandwiched between 24 gauge sheet steel...consists of 6 lb./ft 3 density of mineral wool sandwiched between an inner, 26-gauge, perforated steel panel and an outer, 24-gauge, steel panel. A close

Raloxifen prevents bone loss in castrated male mice.

PubMed

Broulík, P D; Broulíková, K

2007-01-01

Raloxifen is a selective estrogen receptor modulator which prevents bone loss in ovariectomized female mice in a fashion similar to estrogens. Since testosterone-deficient male mice also lose bone mass, we were interested in testing the effects of raloxifen on bones in intact and castrated male mice. Bone density was significantly reduced in castrated animals (1.36+/-0.04 g/ml) as compared to intact animals (1.42+/-0.03 g/ml) (p<0.01). When castrated mice with extraordinarily low concentrations of testosterone and with reduced weight of seminal vesicles were treated with raloxifen, the changes in bone density and bone minerals resulting from castration (1.36+/-0.04 g/ml) were entirely prevented (1.40+/-0.01 g/ml). Cortical bone was lost in orchidectomized mice, and this decrease in cortical thickness of the femur was prevented by raloxifen administration. Raloxifen in a dose used in humans for treatment of osteoporosis decreased the weight of seminal vesicles, an organ which is highly sensitive to the androgenic effect, decreased the concentration of testosterone (12.5+/-2.8 micromol/l) (p<0.01) but not to the same level as in the case of castrated animals (0.6+/-0.3 micromol/l), and did not have any effect on bone density or mineral content in intact mice. The results of the present study may thus be interpreted as supporting the hypothesis that raloxifen is an effective agent against the deleterious effects of castration-induced osteopenia in male mice and also support the hypothesis that estrogens may have physiological skeletal effects in male mice.

The failure of 1D seismic model fitting to constrain lower mantle composition

NASA Astrophysics Data System (ADS)

Houser, C. T.; Hernlund, J. W.; Valencia-Cardona, J. J.; Wentzcovitch, R.

2017-12-01

Tests of lower mantle composition models often compare mineral physics data bearing on the elasticity and density of lower mantle phases to the average seismic velocity profile determined by seismology, such a PREM or ak135. We demonstrate why such comparisons between mineralogy and seismology are an inadequate method for definitive discrimination between different scenarios. One issue is that the seismic velocity is more sensitive to temperature than composition for most lower mantle minerals. In practice, this allows one the freedom to choose the geotherm that brings the predicted seismic and density data into agreement with observations. It is commonly assumed that the temperature profile should be adiabatic, however, such a profile presupposes a particular state of the mantle and is only applicable in the absence of layering, buoyancy fluctuations, compositional segregation, and rheological complexities. The mantle temperature should depend on the composition since the latter influences the viscosity of rocks. However, the precise relation between composition, viscosity, and heat transfer would need to be specified, but unfortunately remains highly uncertain. If the mantle contains a mixture of domains with multiple bulk compositions, then the 1D seismic profile comparison is inherently non-unique. Rocks with different bulk composition likely have different isotopic abundances, and can exhibit differing degrees of internal heating and therefore distinct temperatures. Different composition domains can also exhibit variable densities, and tend to congregate at different depths in ways that also affect their thermal evolution and temperature. Therefore, fitting a 1D seismic model alone is an inadequate tool to evaluate lower mantle composition.

Osteoporosis risk prediction for bone mineral density assessment of postmenopausal women using machine learning.

PubMed

Yoo, Tae Keun; Kim, Sung Kean; Kim, Deok Won; Choi, Joon Yul; Lee, Wan Hyung; Oh, Ein; Park, Eun-Cheol

2013-11-01

A number of clinical decision tools for osteoporosis risk assessment have been developed to select postmenopausal women for the measurement of bone mineral density. We developed and validated machine learning models with the aim of more accurately identifying the risk of osteoporosis in postmenopausal women compared to the ability of conventional clinical decision tools. We collected medical records from Korean postmenopausal women based on the Korea National Health and Nutrition Examination Surveys. The training data set was used to construct models based on popular machine learning algorithms such as support vector machines (SVM), random forests, artificial neural networks (ANN), and logistic regression (LR) based on simple surveys. The machine learning models were compared to four conventional clinical decision tools: osteoporosis self-assessment tool (OST), osteoporosis risk assessment instrument (ORAI), simple calculated osteoporosis risk estimation (SCORE), and osteoporosis index of risk (OSIRIS). SVM had significantly better area under the curve (AUC) of the receiver operating characteristic than ANN, LR, OST, ORAI, SCORE, and OSIRIS for the training set. SVM predicted osteoporosis risk with an AUC of 0.827, accuracy of 76.7%, sensitivity of 77.8%, and specificity of 76.0% at total hip, femoral neck, or lumbar spine for the testing set. The significant factors selected by SVM were age, height, weight, body mass index, duration of menopause, duration of breast feeding, estrogen therapy, hyperlipidemia, hypertension, osteoarthritis, and diabetes mellitus. Considering various predictors associated with low bone density, the machine learning methods may be effective tools for identifying postmenopausal women at high risk for osteoporosis.

Bone and mineral metabolism in adult celiac disease

DOE Office of Scientific and Technical Information (OSTI.GOV)

Caraceni, M.P.; Molteni, N.; Bardella, M.T.

1988-03-01

Bone mineral density (/sup 125/I photon absorptiometry) was lower in 20 untreated adult celiac patients than in sex- and age-matched controls (p less than 0.001), and plasma alkaline phosphatase, parathyroid hormone, urinary hydroxyproline/creatinine levels were higher than normal (p less than 0.05, less than 0.001, less than 0.05, respectively). Gluten-free diet was started, and the patients were divided randomly into two treatment groups, one which received oral 25-hydroxyvitamin D 50 micrograms/day and one which did not. After 12 months' treatment, bone turnover markers showed a decrease, which did not reach statistical significance, and bone mineral density did not show significantmore » modifications compared with base line in either group. It was found that a gluten-free diet followed for 1 yr can prevent further bone loss, but no significant differences were detected between the two groups.« less

Response of the skeletal system to helicopter-unique vibration.

PubMed

Gearhart, J R

1978-01-01

An 18-month prospective skeletal system study was conducted on flying and nonflying personnel relative to chronic low-frequency vibration as experienced in helicopter flight. The aviators were initial entry students in rotary-wing training while the non-flying participants were beginning basic military training. Comparisons were made on the basis of anthropometric measurements, radiological studies, and bone mineral density changes as measured by photon absorption. The bone mineral densitometry showed no significant variation in the aviator group. A short-term 10% demineralization of the distal ulna in the non-flying group was noted immediately following the physical training. The final bone mineral density of basic training subjects returned to the initial level 18 months after the physical training. It was concluded that the helicopter aircrew members under study were exposed to levels of vibration below the threshold of vibration required to produce a measurable change in the skeletal system.

A simple model for remineralization of subsurface lesions in tooth enamel

NASA Astrophysics Data System (ADS)

Christoffersen, J.; Christoffersen, M. R.; Arends, J.

1982-12-01

A model for remineralization of subsurface lesions in tooth enamel is presented. The important assumption on which the model is based is that the rate-controlling process is the crystal surface process by which ions are incorporated in the crystallites; that is, the transport of ions through small holes in the so-called intact surface layer does not influence the rate of mineral uptake at the crystal surface. Further, the density of mineral in the lesion is assumed to increase down the lesion, when the remineralization process is started. It is shown that the dimension of the initial holes in the enamel surface layer must be larger than the dimension of the individual crystallites in order to prevent the formation of arrested lesions. Theoretical expressions for the progress of remineralization are given. The suggested model emphasizes the need for measurements of mineral densities in the lesion, prior to, and during the lesion repair.

Evaluation of cortical bone mass, thickness and density by z-scores in osteopenic conditions and in relation to menopause and estrogen treatment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meema, S.; Meema, H.E.

1982-08-01

Z-scores express, differences from normals in standard deviation units, and are particularly useful for comparison of changes where normal values are age- and sex-dependent. We determined z-scores for bone mineral mass, cortical thickness, and bone mineral density in the radius in various conditions and diseases in both sexes. In the males, z-scores were calculated for age, but in the females z-scores for menopausal status (years postmenopausal exclusive of years on estrogen treatment) were found to be more appropriate. With few exceptions, changes in a disease were of a similar order in both sexes. For bone minerals mass few mean z-scoresmore » were significantly increased, but diseases with significantly decreased mean z-scores were numerous. The usefulness of z-scores in diagnosis and study of metabolic bone disease is discussed.« less

A MATLAB toolbox and Excel workbook for calculating the densities, seismic wave speeds, and major element composition of minerals and rocks at pressure and temperature

NASA Astrophysics Data System (ADS)

Abers, Geoffrey A.; Hacker, Bradley R.

2016-02-01

To interpret seismic images, rock seismic velocities need to be calculated at elevated pressure and temperature for arbitrary compositions. This technical report describes an algorithm, software, and data to make such calculations from the physical properties of minerals. It updates a previous compilation and Excel® spreadsheet and includes new MATLAB® tools for the calculations. The database of 60 mineral end-members includes all parameters needed to estimate density and elastic moduli for many crustal and mantle rocks at conditions relevant to the upper few hundreds of kilometers of Earth. The behavior of α and β quartz is treated as a special case, owing to its unusual Poisson's ratio and thermal expansion that vary rapidly near the α-β transition. The MATLAB tools allow integration of these calculations into a variety of modeling and data analysis projects.

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

PubMed

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 < 0.05 for all). Tibia trabecular variables were also altered. For 1 standard deviation decrease in total hip aBMD or radius trabecular density, odds ratios for 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.

Structural analysis characterization of permeability pathways across reservoir-seal interface - South-Eastern Utah; Results from integrated sedimentological, structural, and geochemical studies.

NASA Astrophysics Data System (ADS)

Petrie, E. S.; Evans, J. P.; Richey, D.; Flores, S.; Barton, C.; Mozley, P.

2015-12-01

Sedimentary rocks in the San Rafael Swell, Utah, were deformed by Laramide compression and subsequent Neogene extension. We evaluate the effect of fault damage zone morphology as a function of structural position, and changes in mechanical stratigraphy on the distribution of secondary minerals across the reservoir-seal pair of the Navajo Sandstone and overlying Carmel Formation. We decipher paleo-fluid migration and examine the effect faults and fractures have on reservoir permeability and efficacy of top seal for a range of geo-engineering applications. Map-scale faults have an increased probability of allowing upward migration of fluids along the fault plane and within the damage zone, potentially bypassing the top seal. Field mapping, mesoscopic structural analyses, petrography, and geochemical observations demonstrate that fault zone thickness increases at structural intersections, fault relay zones, fault-related folds, and fault tips. Higher densities of faults with meters of slip and dense fracture populations are present in relay zones relative to single, discrete faults. Curvature analysis of the San Rafael monocline and fracture density data show that fracture density is highest where curvature is highest in the syncline hinge and near faults. Fractures cross the reservoir-seal interface where fracture density is highest and structural diagensis includes mineralization events and bleaching and calcite and gypsum mineralization. The link between fracture distributions and structural setting implys that transmissive fractures have predictable orientations and density distributions. At the m- to cm- scale, deformation-band faults and joints in the Navajo Sandstone penetrate the reservoir-seal interface and transition into open-mode fractures in the caprock seal. Scanline analysis and petrography of veins provide evidence for subsurface mineralization and fracture reactivation, suggesting that the fractures act as loci for fluid flow through time. Heterolithic caprock seals with variable fracture distributions and morphology highlight the strong link between the variation in material properties and the response to changing stress conditions. The variable connectivity of fractures and the changes in fracture density plays a critical role in subsurface fluid flow.

A Review of the Effect of Anticonvulsant Medications on Bone Mineral Density and Fracture Risk

PubMed Central

Lee, Richard H.; Lyles, Kenneth W.; Colón-Emeric, Cathleen

2011-01-01

Background Osteoporosis and seizure disorders are common diagnoses in older adults and often occur concomitantly. Objective The goal of this review was to discuss the current hypothesis for the pathogenesis of anticonvulsant-induced bone density loss and the evidence regarding the risk for osteoporosis and fractures in older individuals. Methods A review of the literature was performed, searching in MEDLINE and CINAHL for articles published between 1990 and October 2009 with the following search terms: anticonvulsant OR antiepileptic; AND osteoporosis OR bone density OR fracture OR absorptiometry, photon. Studies within the pediatric population, cross-sectional studies, and studies whose results were published in a language other than English were excluded. Results A search of the published literature yielded >300 results, of which 24 met the inclusion and exclusion criteria and were included in this review. Hepatic enzyme induction by certain anticonvulsant medications appears to contribute to increased metabolism of 25-hydroxyvitamin D to inactive metabolites, which results in metabolic bone disease. There is increasing evidence that anticonvulsant use is associated with a higher risk of osteoporosis and clinical fractures, especially among older agents such as phenobarbital, carbamazepine, phenytoin, and valproate. Several observational studies suggest a class effect among anticonvulsant agents, associated with clinically significant reductions in bone mineral density and fracture risk. The use of anticonvulsant medications increases the odds of fracture by 1.2 to 2.4 times. However, only 2 large-scale observational studies have specifically examined the risk among those aged >65 years. This review also identified a randomized controlled trial whose results suggest that supplementation with high-dose vitamin D may be associated with increased bone mineral density in patients taking anticonvulsant medications. However, no randomized controlled trials investigating therapeutic agents to prevent fracture in this population were identified. Consequently, there are no formal practice guidelines for the monitoring, prevention, and management of bone disease among those taking anticonvulsants. Conclusions Observational studies suggest an association between use of anticonvulsant medications, reduced bone mineral density, and increased fracture risk. Randomized clinical trials are needed to guide the management of bone disease among those who use anticonvulsants. PMID:20226391

Impaired rib bone mass and quality in end-stage cystic fibrosis patients.

PubMed

Mailhot, Geneviève; Dion, Natalie; Farlay, Delphine; Rizzo, Sébastien; Bureau, Nathalie J; Jomphe, Valérie; Sankhe, Safiétou; Boivin, Georges; Lands, Larry C; Ferraro, Pasquale; Ste-Marie, Louis-Georges

2017-05-01

Advancements in research and clinical care have considerably extended the life expectancy of cystic fibrosis (CF) patients. However, with this extended survival come comorbidities. One of the leading co-morbidities is CF-related bone disease (CFBD), which progresses with disease severity and places patients at high risk for fractures, particularly of the ribs and vertebrae. Evidence that CF patients with vertebral fractures had higher bone mineral density (BMD) than the nonfracture group led us to postulate that bone quality is impaired in these patients. We therefore examined rib specimens resected at the time of lung transplant in CF patients to measure parameters of bone quantity and quality. In this exploratory study, we analysed 19 end-stage CF and 13 control rib specimens resected from otherwise healthy lung donors. BMD, bone microarchitecture, static parameters of bone formation and resorption and microcrack density of rib specimens were quantified by imaging, histomorphometric and histological methods. Variables reflecting the mineralization of ribs were assessed by digitized microradiography. The degree of bone mineralization (g/cm 3 ) and the heterogeneity index of the mineralization (g/cm 3 ) were calculated for trabecular and cortical bone. Compared to controls, CF ribs exhibited lower areal and trabecular volumetric BMD, decreased trabecular thickness and osteoid parameters, and increased microcrack density, that was particularly pronounced in specimens from patients with CF-related diabetes. Static parameters of bone resorption were similar in both groups. Degree of mineralization of total bone, but not heterogeneity index, was increased in CF specimens. The combination of reduced bone mass, altered microarchitecture, imbalanced bone remodeling (maintained bone resorption but decreased formation), increased microdamage and a small increase of the degree of mineralization, may lead to decreased bone strength, which, when coupled with chronic coughing and chest physical therapy, may provide an explanation for the increased incidence of rib fractures previously reported in this population. Copyright © 2017 Elsevier Inc. All rights reserved.

Lindane degradation by electrooxidation process: Effect of electrode materials on oxidation and mineralization kinetics.

PubMed

Dominguez, Carmen M; Oturan, Nihal; Romero, Arturo; Santos, Aurora; Oturan, Mehmet A

2018-05-15

This study focuses on the effect of electrode materials on abatement of lindane (an organochlorine pesticide) by electrooxidation process. Comparative performances of different anodic (platinum (Pt), dimensionally stable anode (DSA) and boron-doped diamond (BDD)) and cathodic (carbon sponge (CS), carbon felt (CF) and stainless steel (SS)) materials on lindane electrooxidation and mineralization were investigated. Special attention was paid to determine the role of chlorine active species during the electrooxidation process. The results showed that better performances were obtained when using a BDD anode and CF cathode cell. The influence of the current density was assessed to optimize the oxidation of lindane and the mineralization of its aqueous solution. A quick (10 min) and complete oxidation of 10 mg L -1 lindane solution and relatively high mineralization degree (80% TOC removal) at 4 h electrolysis were achieved at 8.33 mA cm -2 current density. Lindane was quickly oxidized by in-situ generated hydroxyl radicals, (M( • OH)), formed from oxidation of water on the anode (M) surface following pseudo first-order reaction kinetics. Formation of chlorinated and hydroxylated intermediates and carboxylic acids during the treatment were identified and a plausible mineralization pathway of lindane by hydroxyl radicals was proposed. Copyright © 2018 Elsevier Ltd. All rights reserved.

[Histochemical stains for minerals by hematoxylin-lake method].

PubMed

Miyagawa, Makoto

2013-04-01

The present study was undertaken to establish the experimental animal model by histological staining methods for minerals. After intraperitoneal injections of minerals, precipitates deposited on the surface of the liver. Liver tissues were fixed in paraformaldehyde, embedded in paraffin and cut into thin sections which were used as minerals containing standard section. Several reagents for histological stains and spectrophotometry for minerals were applied in both test-tube experiments and stainings of tissue sections to test for minerals. Hematoxylin-lake was found of capable of staining minerals in tissue. A simple technique used was described for light microscopic detection of minerals.

In vivo short-term precision of hip structure analysis variables in comparison with bone mineral density using paired dual-energy X-ray absorptiometry scans from multi-center clinical trials.

PubMed

Khoo, Benjamin C C; Beck, Thomas J; Qiao, Qi-Hong; Parakh, Pallav; Semanick, Lisa; Prince, Richard L; Singer, Kevin P; Price, Roger I

2005-07-01

Hip structural analysis (HSA) is a technique for extracting strength-related structural dimensions of bone cross-sections from two-dimensional hip scan images acquired by dual energy X-ray absorptiometry (DXA) scanners. Heretofore the precision of the method has not been thoroughly tested in the clinical setting. Using paired scans from two large clinical trials involving a range of different DXA machines, this study reports the first precision analysis of HSA variables, in comparison with that of conventional bone mineral density (BMD) on the same scans. A key HSA variable, section modulus (Z), biomechanically indicative of bone strength during bending, had a short-term precision percentage coefficient of variation (CV%) in the femoral neck of 3.4-10.1%, depending on the manufacturer or model of the DXA equipment. Cross-sectional area (CSA), a determinant of bone strength during axial loading and closely aligned with conventional DXA bone mineral content, had a range of CV% from 2.8% to 7.9%. Poorer precision was associated with inadequate inclusion of the femoral shaft or femoral head in the DXA-scanned hip region. Precision of HSA-derived BMD varied between 2.4% and 6.4%. Precision of DXA manufacturer-derived BMD varied between 1.9% and 3.4%, arising from the larger analysis region of interest (ROI). The precision of HSA variables was not generally dependent on magnitude, subject height, weight, or conventional femoral neck densitometric variables. The generally poorer precision of key HSA variables in comparison with conventional DXA-derived BMD highlights the critical roles played by correct limb repositioning and choice of an adequate and appropriately positioned ROI.

Cumulative effects of calcium supplementation and physical activity on bone accretion in premenarchal children: a double-blind randomised placebo-controlled trial.

PubMed

Courteix, D; Jaffré, C; Lespessailles, E; Benhamou, L

2005-06-01

High calcium intake combined with physical activity during childhood have been shown to improve bone mass accrual and bone mineral density. Our aim was to study the combined effect of calcium and exercise on bone gain in children. Two milk-powder products containing either 800 mg of calcium phosphate (calcium) or not (placebo) were randomly allocated to 113 healthy premenarchal girls on a daily basis for 1 year. The group was composed of 63 exercise (7.2 +/- 4 hours of exercise/week) and 50 sedentary (1.2 +/- 0.8 hours of exercise/week) children. The final experiment had 4 groups: exercise/calcium (n = 12), exercise/placebo (n = 42), sedentary/calcium (n = 10), and sedentary/placebo (n = 21). Bone mineral density (BMD) at 6 skeletal sites and body composition were determined by DXA. Bone age was calculated and the daily spontaneous calcium intake was assessed by a frequency questionnaire. All the tests were performed at baseline and 1 year by the same observer. BMD gains were significantly greater in the exercise/calcium group than in other groups at the total body (increase of 6.3 %, p < 0.05), lumbar spine (11 %, p < 0.05), femoral neck (8.2 %, p < 0.02), and Ward's triangle (9.3 %, p < 0.01). There was no difference between the other groups. These data suggest that calcium supplementation increases the effect of physical exercise on bone mineral acquisition in the period preceding puberty, and that calcium supplementation without physical activity does not improve the BMD acquisition during this period. Physical exercise that stimulates bone accretion needs a high calcium intake to be completely effective.

Ultrasonic degradation, mineralization and detoxification of diclofenac in water: optimization of operating parameters.

PubMed

Naddeo, V; Belgiorno, V; Kassinos, D; Mantzavinos, D; Meric, S

2010-01-01

The 20 kHz ultrasound-induced degradation of non-steroidal, anti-inflammatory drug diclofenac (DCF) was investigated. Several operating conditions, such as power density (25-100 W/L), substrate concentration (2.5-80 mg/L), initial solution pH (3.5-11), liquid bulk temperature and the type of sparging gas (air, oxygen, argon), were tested concerning their effect on DCF degradation (as assessed measuring absorbance at 276 nm) and hydroxyl radicals generation (as assessed measuring H(2)O(2) concentration). Sample mineralization (in terms of TOC and COD removal), aerobic biodegradability (as assessed by the BOD(5)/COD ratio) and ecotoxicity to Daphnia magna and Artemia salina were followed too. DCF conversion is enhanced at increased applied power densities and liquid bulk temperatures, acidic conditions and in the presence of dissolved air or oxygen. The reaction rate increases with increasing DCF concentration in the range 2.5-5mg/L but it remains constant in the range 40-80 mg/L, indicating different kinetic regimes (i.e. first and zero order, respectively). H(2)O(2) production rates in pure water are higher than those in DCF solutions, implying that decomposition basically proceeds through hydroxyl radical reactions. Mineralization is a slow process as reaction by-products are more stable than DCF to total oxidation; nonetheless, they are also more readily biodegradable. Toxicity to D. magna increases during the early stages of the reaction and then decreases progressively upon degradation of reaction by-products; nevertheless, complete toxicity elimination cannot be achieved at the conditions in question. Neither the original nor the treated DCF samples are toxic to A. salina.

Natural calcium isotopic composition of urine as a marker of bone mineral balance.

PubMed

Skulan, Joseph; Bullen, Thomas; Anbar, Ariel D; Puzas, J Edward; Shackelford, Linda; LeBlanc, Adrian; Smith, Scott M

2007-06-01

We investigated whether changes in the natural isotopic composition of calcium in human urine track changes in net bone mineral balance, as predicted by a model of calcium isotopic behavior in vertebrates. If so, isotopic analysis of natural urine or blood calcium could be used to monitor short-term changes in bone mineral balance that cannot be detected with other techniques. Calcium isotopic compositions are expressed as delta(44)Ca, or the difference in parts per thousand between the (44)Ca/(40)Ca of a sample and the (44)Ca/(40)Ca of a standard reference material. delta(44)Ca was measured in urine samples from 10 persons who participated in a study of the effectiveness of countermeasures to bone loss in spaceflight, in which 17 weeks of bed rest was used to induce bone loss. Study participants were assigned to 1 of 3 treatment groups: controls received no treatment, one treatment group received alendronate, and another group performed resistive exercise. Measurements were made on urine samples collected before, at 2 or 3 points during, and after bed rest. Urine delta(44)Ca values during bed rest were lower in controls than in individuals treated with alendronate (P <0.05, ANOVA) or exercise (P <0.05), and lower than the control group baseline (P <0.05, t-test). Results were consistent with the model and with biochemical and bone mineral density data. Results confirm the predicted relationship between bone mineral balance and calcium isotopes, suggesting that calcium isotopic analysis of urine might be refined into a clinical and research tool.

Magnetic susceptibility of ultrahigh pressure eclogite: The role of retrogression

NASA Astrophysics Data System (ADS)

Xu, Haijun; Jin, Zhenmin; Mason, Roger; Ou, Xingong

2009-09-01

Retrograde metamorphism played the dominant role in changing the low-field rock magnetic properties and density of 198 specimens of variably retrograded eclogites from the main borehole of the Chinese Continental Scientific Drilling Project (CCSD) and from surface outcrops in the Donghai area in the southern part of the Sulu UHP belt, China. Bulk magnetic susceptibility ( κ) of unretrogressed UHP eclogite is controlled by whole-rock chemical composition and ranges from 397 to 2312 μSI with principal magnetic susceptibility carrying minerals paramagnetic garnet, omphacite, rutile and phengite. Partially retrograded eclogites show large variations in magnetic susceptibility between 804 and 24,277 μSI, with high mean magnetic susceptibility values of 4372 ± 4149 μSI caused by appreciable amounts of Fe-Ti oxide minerals such as magnetite, ilmenite and/or titanohematite produced by retrograde metamorphic reactions. Completely retrograded eclogites have lower susceptibilities of 1094 ± 600 μSI and amphibolite facies mineral assemblages lacking high magnetic susceptibility minerals. Jelínek's corrected anisotropy ( Pj) of eclogites ranges from 1.001 to 1.540, and shows a positive correlation with low-field magnetic susceptibility ( κ). Arithmetic mean bulk density ( ρ) shows a steady decrease from 3.54 ± 0.11 g/cm 3 (fresh eclogite) to 2.98 ± 0.06 g/cm 3 (completely retrograded eclogite). Retrograde metamorphic changes in mineral composition during exhumation appear to be the major factor causing variations in low field magnetic susceptibility and anisotropy. Retrograde processes must be taken into account when interpreting magnetic surveys and geophysical well logs in UHP metamorphic terranes, and petrophysical properties such as density and low-field magnetic susceptibility could provide a means for semi-quantifying the degree of retrogression of eclogite during exhumation.

Quantitative determination of the mineral distribution in different collagen zones of calcifying tendon using high voltage electron microscopic tomography

NASA Technical Reports Server (NTRS)

McEwen, B. F.; Song, M. J.; Landis, W. J.

1991-01-01

High voltage electron microscopic tomography was used to make the first quantitative determination of the distribution of mineral between different regions of collagen fibrils undergoing early calcification in normal leg tendons of the domestic turkey, Meleagris gallopavo. The tomographic 3-D reconstruction was computed from a tilt series of 61 different views spanning an angular range of +/- 60 degrees in 2 degrees intervals. Successive applications of an interactive computer operation were used to mask the collagen banding pattern of either hole or overlap zones into separate versions of the reconstruction. In such 3-D volumes, regions specified by the mask retained their original image density while the remaining volume was set to background levels. This approach was also applied to the mineral crystals present in the same volumes to yield versions of the 3-D reconstructions that were masked for both the crystal mass and the respective collagen zones. Density profiles from these volumes contained a distinct peak corresponding only to the crystal mass. A comparison of the integrated density of this peak from each profile established that 64% of the crystals observed were located in the collagen hole zones and 36% were found in the overlap zones. If no changes in crystal stability occur once crystals are formed, this result suggests the possibilities that nucleation of mineral is preferentially and initially associated with the hole zones, nucleation occurs more frequently in the hole zones, the rate of crystal growth is more rapid in the hole zones, or a combination of these alternatives. All lead to the conclusion that the overall accumulation of mineral mass is predominant in the collagen hole zones compared to overlap zones during early collagen fibril calcification.

The effect of FokI vitamin D receptor polymorphism on bone mineral density in Jordanian perimenopausal women

PubMed Central

Kanan, Raed M.

2013-01-01

CONTEXT: Osteoporosis is a polygenic, multifactorial disease that is characterized by demineralization of bone, and thus presented with decreasing bone mineral mass. Vitamin D receptor (VDR) gene polymorphisms in the 3’-end region (as determined by the enzymes BsmI and ApaI) have been inconsistently associated with bone mineral mass. Another important VDR start codon polymorphism (as determined by the enzyme FokI) has been found to be related to adult bone mineral density (BMD) in pre-and post-menopausal American women. AIMS: This study aims to investigate the prevalence of the FokI VDR gene polymorphism in Jordanian perimenopausal women and study its relationship with bone mineral density. MATERIALS AND METHODS: DNA was isolated from 90 controls (Mean age = 50.41 ± 1.29 y), and 120 patients with symptomatic vertebral fractures (Mean age = 49.14 ± 3.19 y). Restriction Fragment Length Polymorphism (RFLP) analysis of FokI was performed on DNA samples. STATISTICAL ANALYSIS: Data was analyzed using SPSS v19 and Microsoft Excel 2007. RESULTS: The results showed that in controls, the FF (−0.70 ± 0.51) genotype is associated with high lumbar spine BMD Z-score as compared to Ff (−1.25 ± 0.26) and ff (−1.66 ± 0.47) genotypes (P = 0.0095). In patients, the ff genotype was associated with lower lumbar spine BMD in T-score (−2.31 ± 0.17) and Z-score (−1.56 ± 0.09) genotypes (P = 0.031). No significant association was seen in the femoral neck BMD. CONCLUSION: FokI polymorphism may be associated with low BMD in our studied population; however, further studies including other polymorphisms and large sample number are needed. PMID:24019627

Development of an analytical technique for the detection of alteration minerals formed in bentonite by reaction with alkaline solutions

NASA Astrophysics Data System (ADS)

Sakamoto, H.; Shibata, M.; Owada, H.; Kaneko, M.; Kuno, Y.; Asano, H.

A multibarrier system consisting of cement-based backfill, structures and support materials, and a bentonite-based buffer material has been studied for the TRU waste disposal concept being developed in Japan, the aim being to restrict the migration of radionuclides. Concern regarding bentonite-based materials in this disposal environment relates to long-term alteration under hyper-alkaline conditions due to the presence of cementitious materials. In tests simulating the interaction between bentonite and cement, formation of secondary minerals due to alteration reactions under the conditions expected for geological disposal of TRU waste (equilibrated water with cement at low liquid/solid ratio) has not been observed, although alteration was observed under extremely hyper-alkaline conditions with high temperatures. This was considered to be due to the fact that analysis of C-S-H gel formed at the interface as a secondary mineral was difficult using XRD, because of its low crystallinity and low content. This paper describes an analytical technique for the characterization of C-S-H gel using a heavy liquid separation method which separates C-S-H gel from Kunigel V1 bentonite (bentonite produced in Japan) based on the difference in specific gravity between the crystalline minerals constituting Kunigel V1 and the secondary C-S-H gel. For development of C-S-H gel separation methods, simulated alteration samples were prepared by mixing 990 mg of unaltered Kunigel V1 and 10 mg of C-S-H gel synthesized using pure chemicals at a ratio of Ca/Si = 1.2. The simulated alteration samples were dispersed in bromoform-methanol mixtures with specific gravities ranging from 2.00 to 2.57 g/cm 3 and subjected to centrifuge separation to recover the light density fraction. Subsequent XRD analysis to identify the minerals was complemented by dissolution in 0.6 N hydrochloric acid to measure the Ca and Si contents. The primary peak (2 θ = 29.4°, Cu Kα) and secondary peaks (2 θ = 32.1° and 50.1°, Cu Kα) of the C-S-H gel, which could not be distinguished before the heavy liquid separation, were clearly identified by XRD after separation. The result of the analyses of the light density fraction indicates highest recovery of C-S-H gel and least inclusion of bentonite for separation using heavy liquid with a specific gravity of 2.10 g/cm 3. The traces of bentonite minerals included in the suspension were identified to be montmorillonite, quartz, clinoptilolite, and calcite. The separation technique was also tested for Ca-bentonite prepared by passing a calcium hydroxide solution through a bentonite (Kunigel V1)-silica sand mixture. The results indicated that the technique would also be applicable to separation of C-S-H gel from Ca-bentonite.

Integrated Resistance and Aerobic Training Study - Sprint

NASA Technical Reports Server (NTRS)

Ploutz-Snyder, Lori; Moore, Alan; Ryder, Jeffrey; Everett, Meg; Bloomberg, Jacob; Sibonga, Jean; Shackelford, Linda; Platts, Steven; Martin, David; Ploutz-Snyder, Robert;

Microstructural features of carious human enamel imaged with back-scattered electrons.

PubMed

Pearce, E I; Nelson, D G

1989-02-01

We have used back-scattered electrons (BE) in the scanning electron microscope to produce mineral density images of enamel. Flat surfaces of artificially-carious enamel, softened in an intra-oral experiment, and naturally-carious (white spot) enamel were polished to a high gloss with diamond lapping compound, rendering them almost featureless by secondary electron scanning electron microscopy. They were then examined at 10 to 30 kV in a Philips 505 instrument fitted with a 4-quadrant BE detector. Study of surfaces prepared approximately parallel to the natural surface showed that mineral was lost from both prism core and the interprismatic region, leaving a thin mineral-rich rim at the prism periphery. The same lesions viewed longitudinally on a surface prepared perpendicular to the natural surface showed mineral-rich bands at the prism margins in the outer enamel. Near the advancing front of the lesion, the prism junctions were widened and the prism cores sometimes hypermineralized. Natural lesions sectioned in the prism long axis showed features previously seen with other techniques, e.g., cross-striations and striae of Retzius, but in much greater detail. Mineral enrichment at the prism periphery in the lesion body and a widening of the prism junction at the advancing fronts of lesions in permanent teeth were most obvious. Calculations showed that with an accelerating voltage of 30 kV, the images reflected mineral density up to 4 microns beneath the surface. BE microscopy produces a high-resolution image of mineral loss or gain in carious enamel, with relatively easy sample preparation.

Efficacy and Harms of Nasal Calcitonin in Improving Bone Density in Young Patients with Inflammatory Bowel Disease: a Randomized, Placebo-Controlled, Double-Blind Trial

PubMed Central

Pappa, Helen M.; Saslowsky, Tracee M.; Filip-Dhima, Rajna; DiFabio, Diane; Hassani Lahsinoui, Hajar; Akkad, Apurva; Grand, Richard J.; Gordon, Catherine M.

2011-01-01

Background & Aims There are very few published studies of agents having the potential to improve bone health in children with inflammatory bowel disease (IBD). Our aim was to establish the efficacy and safety of intranasal calcitonin in improving bone mineral density (BMD) in young patients with IBD and to define additional factors that impact bone mineral accrual. Methods We conducted a randomized, placebo-controlled, double-blind clinical trial in sixty-three participants, ages 8 to 21 yrs, with a spinal BMD Z-score ≤ −1.0 SD measured by dual energy X-Ray absorptiometry (DXA). Subjects were randomized to 200 IU intranasal calcitonin (n=31) or placebo (n=32) daily. All received age-appropriate calcium and vitamin D supplementation. Subsequent BMD measurements were obtained at 9 and 18 months. Results Intranasal calcitonin was well-tolerated. Adverse event frequency was similar in both treatment groups, and such events were primarily minor, reversible, and limited to the upper respiratory tract. The BMD Z-score change documented at screening and 9 months and screening and 18 months did not differ between the two therapeutic arms. In participants with Crohn’s disease (CD) the spinal BMD Z-score improved between screening and 9 months [ΔZSBMD(9-0)] in the calcitonin group (ΔZSBMD(9-0)calcitonin = 0.21 (0.37), ΔZSBMD(9-0)placebo = −0.15 (0.5), p = 0.02), however this was only a secondary subgroup analysis. Bone mineral accrual rates during the trial did not lead to normalization of BMD Z-scores in this cohort. Factors favoring higher bone mineral accrual rate were: lower baseline BMD and higher baseline body mass index (BMI) Z-score, improvement in height Z-score, higher serum albumin, hematocrit and iron concentration, and more hours of weekly weight-bearing activity. Factors associated with lower bone mineral accrual rate were: more severe disease – as indicated by elevated inflammatory markers, need for surgery, hospitalization and the use of immunomodulators - and higher amount of caffeine intake. Conclusions Intranasal calcitonin is well-tolerated but does not offer a long-term advantage in youth with IBD and decreased BMD. Bone mineral accrual rates remain compromised in youth with IBD and low bone mineral density raising concerns for long-term bone health outcomes. Improvement in nutritional status, catch-up linear growth, control of inflammation, increase in weight-bearing activity, and lower caffeine intake may be helpful in restoring bone density, especially in children with IBD and low baseline BMD. PMID:21519359

Hyperlipidemia affects multiscale structure and strength of murine femur.

PubMed

Ascenzi, Maria-Grazia; Lutz, Andre; Du, Xia; Klimecky, Laureen; Kawas, Neal; Hourany, Talia; Jahng, Joelle; Chin, Jesse; Tintut, Yin; Nackenhors, Udo; Keyak, Joyce

2014-07-18

To improve bone strength prediction beyond limitations of assessment founded solely on the bone mineral component, we investigated the effect of hyperlipidemia, present in more than 40% of osteoporotic patients, on multiscale structure of murine bone. Our overarching purpose is to estimate bone strength accurately, to facilitate mitigating fracture morbidity and mortality in patients. Because (i) orientation of collagen type I affects, independently of degree of mineralization, cortical bone׳s micro-structural strength; and, (ii) hyperlipidemia affects collagen orientation and μCT volumetric tissue mineral density (vTMD) in murine cortical bone, we have constructed the first multiscale finite element (mFE), mouse-specific femoral model to study the effect of collagen orientation and vTMD on strength in Ldlr(-/-), a mouse model of hyperlipidemia, and its control wild type, on either high fat diet or normal diet. Each µCT scan-based mFE model included either element-specific elastic orthotropic properties calculated from collagen orientation and vTMD (collagen-density model) by experimentally validated formulation, or usual element-specific elastic isotropic material properties dependent on vTMD-only (density-only model). We found that collagen orientation, assessed by circularly polarized light and confocal microscopies, and vTMD, differed among groups and that microindentation results strongly correlate with elastic modulus of collagen-density models (r(2)=0.85, p=10(-5)). Collagen-density models yielded (1) larger strains, and therefore lower strength, in simulations of 3-point bending and physiological loading; and (2) higher correlation between mFE-predicted strength and 3-point bending experimental strength, than density-only models. This novel method supports ongoing translational research to achieve the as yet elusive goal of accurate bone strength prediction. Copyright © 2014 Elsevier Ltd. All rights reserved.

Variations in Urine Calcium Isotope: Composition Reflect Changes in Bone Mineral Balance in Humans

NASA Technical Reports Server (NTRS)

Skulan, Joseph; Anbar, Ariel; Bullen, Thomas; Puzas, J. Edward; Shackelford, Linda; Smith, Scott M.

2004-01-01

Changes in bone mineral balance cause rapid and systematic changes in the calcium isotope composition of human urine. Urine from subjects in a 17 week bed rest study was analyzed for calcium isotopic composition. Comparison of isotopic data with measurements of bone mineral density and metabolic markers of bone metabolism indicates the calcium isotope composition of urine reflects changes in bone mineral balance. Urine calcium isotope composition probably is affected by both bone metabolism and renal processes. Calcium isotope. analysis of urine and other tissues may provide information on bone mineral balance that is in important respects better than that available from other techniques, and illustrates the usefulness of applying geochemical techniques to biomedical problems.

Trapezium Bone Density-A Comparison of Measurements by DXA and CT.

PubMed

Breddam Mosegaard, Sebastian; Breddam Mosegaard, Kamille; Bouteldja, Nadia; Bæk Hansen, Torben; Stilling, Maiken

2018-01-18

Bone density may influence the primary fixation of cementless implants, and poor bone density may increase the risk of implant failure. Before deciding on using total joint replacement as treatment in osteoarthritis of the trapeziometacarpal joint, it is valuable to determine the trapezium bone density. The aim of this study was to: (1) determine the correlation between measurements of bone mineral density of the trapezium obtained by dual-energy X-ray absorptiometry (DXA) scans by a circumference method and a new inner-ellipse method; and (2) to compare those to measurements of bone density obtained by computerized tomography (CT)-scans in Hounsfield units (HU). We included 71 hands from 59 patients with a mean age of 59 years (43-77). All patients had Eaton-Glickel stage II-IV trapeziometacarpal (TM) joint osteoarthritis, were under evaluation for trapeziometacarpal total joint replacement, and underwent DXA and CT wrist scans. There was an excellent correlation (r = 0.94) between DXA bone mineral density measures using the circumference and the inner-ellipse method. There was a moderate correlation between bone density measures obtained by DXA- and CT-scans with (r = 0.49) for the circumference method, and (r = 0.55) for the inner-ellipse method. DXA may be used in pre-operative evaluation of the trapezium bone quality, and the simpler DXA inner-ellipse measurement method can replace the DXA circumference method in estimation of bone density of the trapezium.

Loss of BMP signaling through BMPR1A in osteoblasts leads to greater collagen cross-link maturation and material-level mechanical properties in mouse femoral trabecular compartments

PubMed Central

Zhang, Yanshuai; McNerny, Erin Gatenby; Terajima, Masahiko; Raghavan, Mekhala; Romanowicz, Genevieve; Zhang, Zhanpeng; Zhang, Honghao; Kamiya, Nobuhiro; Tantillo, Margaret; Zhu, Peizhi; Scott, Gregory J.; Ray, Manas K.; Lynch, Michelle; Ma, Peter X.; Morris, Michael D.; Yamauchi, Mitsuo; Kohn, David H.; Mishina, Yuji

2016-01-01

Bone morphogenetic protein (BMP) signaling pathways play critical roles in skeletal development and new bone formation. Our previous study, however, showed a negative impact of BMP signaling on bone mass because of the osteoblast-specific loss of a BMP receptor (i.e. BMPR1A) showing increased trabecular bone volume and mineral density in mice. Here, we investigated the bone quality and biomechanical properties of the higher bone mass associated with BMPR1A deficiency using the osteoblast-specific Bmpr1a conditional knockout (cKO) mouse model. Collagen biochemical analysis revealed greater levels of the mature cross-link pyridinoline in the cKO bones, in parallel with upregulation of collagen modifying enzymes. Raman spectroscopy distinguished increases in the mature to immature cross-link ratio and mineral to matrix ratio in the trabecular compartments of cKO femora, but not in the cortical compartments. The mineral crystallinity was unchanged in the cKO in either the trabecular or cortical compartments. Further, we tested the intrinsic material properties by nanoindentation and found significantly higher hardness and elastic modulus in the cKO trabecular compartments, but not in the cortical compartments. Four point bending tests of cortical compartments showed lower structural biomechanical properties (i.e. strength and stiffness) in the cKO bones due to the smaller cortical areas. However, there were no significant differences in biomechanical performance at the material level, which was consistent with the nanoindentation test results on the cortical compartment. These studies emphasize the pivotal role of BMPR1A in the determination of bone quality and mechanical integrity under physiological conditions, with different impact on femoral cortical and trabecular compartments. PMID:27113526

Does peripheral quantitative computed tomography ignore tissue density of cancellous bone?

PubMed

Banse, X; Devogelaer, J P

2002-01-01

The purpose of this work was to determine the capacity of peripheral quantitative computed tomography (pQCT) to accurately measure the true physical properties of vertebral cancellous bone samples and to predict their stiffness. pQCT bone mineral density (BMD) was first measured in ideal conditions. Ten cubic specimens of vertebral cancellous bone (10 x 10 x 10 mm) were washed with a water jet, defatted, and scanned in saline after elimination of air bubbles; thirteen slices were obtained. Seventy-one unprepared cylindrical samples were scanned in more realistic conditions, which allow further biomechanical testing. After extraction from the vertebral body, the samples were pushed into a plastic tube (no effort was made to remove the marrow or air bubbles), and only four slices were obtained to reduce the duration of scan. For the 81 samples, the true bone volume fraction (BV/TV, %), true apparent density (rho(app), g/cm(3)), and tissue density (rho(tiss), g/cm(3)) (an indicator of the degree of mineralization of the matrix) were then measured using Archimedes principle. rho(app) was closely correlated to BV/TV (r(2) = 0.97). rho(tiss) (1.58 +/- 0.08 g/cm(2)) was almost constant but had some influence on rho(app) (r(2) = 0.03, p < 0.001). The pQCT BMD predicted accurately rho(app) (r(2) = 0.96) and BV/TV (r(2) = 0.93) for the cylinders. For the cubes, in ideal conditions, the same correlations were even better (r(2) > 0.99, both). Analysis of covariance indicated no difference (p > 0.05) in the regressions due to preparation of the samples. The stiffness was better predicted by the true rho(app) (r(2) = 0.87) than by BV/TV (r(2) = 0.83), indicating that stiffness was influenced by small differences in the tissue density. Consequently, the correlation between pQCT BMD and stiffness was excellent (r(2) = 0.84). The fact that pQCT did not ignore this tissue density information compensated for the inaccuracies linked to realistic scanning conditions of the cylinder.

Experimental investigation of sound absorption of acoustic wedges for anechoic chambers

NASA Astrophysics Data System (ADS)

Belyaev, I. V.; Golubev, A. Yu.; Zverev, A. Ya.; Makashov, S. Yu.; Palchikovskiy, V. V.; Sobolev, A. F.; Chernykh, V. V.

2015-09-01

The results of measuring the sound absorption by acoustic wedges, which were performed in AC-3 and AC-11 reverberation chambers at the Central Aerohydrodynamic Institute (TsAGI), are presented. Wedges of different densities manufactured from superfine basaltic and thin mineral fibers were investigated. The results of tests of these wedges were compared to the sound absorption of wedges of the operating AC-2 anechoic facility at TsAGI. It is shown that basaltic-fiber wedges have better sound-absorption characteristics than the investigated analogs and can be recommended for facing anechoic facilities under construction.

The relationship between breast density and bone mineral density in postmenopausal women.

PubMed

Buist, Diana S M; Anderson, Melissa L; Taplin, Stephen H; LaCroix, Andrea Z

2004-11-01

It is not well understood whether breast density is a marker of cumulative exposure to estrogen or a marker of recent exposure to estrogen. The authors examined the relationship between bone mineral density (BMD; a marker of lifetime estrogen exposure) and breast density. The authors conducted a cross-sectional analysis among 1800 postmenopausal women > or = 54 years. BMD data were taken from two population-based studies conducted in 1992-1993 (n = 1055) and in 1998-1999 (n = 753). The authors linked BMD data with breast density information collected as part of a mammography screening program. They used linear regression to evaluate the density relationship, adjusted for age, hormone therapy use, body mass index (BMI), and reproductive covariates. There was a small but significant negative association between BMD and breast density. The negative correlation between density measures was not explained by hormone therapy or age, and BMI was the only covariate that notably influenced the relationship. Stratification by BMI only revealed the negative correlation between bone and breast densities in women with normal BMI. There was no relationship in overweight or obese women. The same relationship was seen for all women who had never used hormone therapy, but it was not significant once stratified by BMI. BMD and breast density were not positively associated although both are independently associated with estrogen exposure. It is likely that unique organ responses obscure the relationship between the two as indicators of cumulative estrogen exposure.

Mineralization dynamics of metakaolin-based alkali-activated cements

USGS Publications Warehouse

Gevaudan, Juan Pablo; Campbell, Kate M.; Kane, Tyler; Shoemaker, Richard K.; Srubar, Wil V.

2017-01-01

This paper investigates the early-age dynamics of mineral formation in metakaolin-based alkali-activated cements. The effects of silica availability and alkali content on mineral formation were investigated via X-ray diffraction and solid-state 29Si magic-angle spinning nuclear magnetic resonance spectroscopy at 2, 7, 14, and 28 days. Silica availability was controlled by using either liquid- (immediate) or solid-based (gradual) sodium silicate supplements. Mineral (zeolitic) and amorphous microstructural characteristics were correlated with observed changes in bulk physical properties, namely shrinkage, density, and porosity. Results demonstrate that, while alkali content controls the mineralization in immediately available silica systems, alkali content controls the silica availability in gradually available silica systems. Immediate silica availability generally leads to a more favorable mineral formation as demonstrated by correlated improvements in bulk physical properties.

Automated Reporting of DXA Studies Using a Custom-Built Computer Program.

PubMed

England, Joseph R; Colletti, Patrick M

2018-06-01

Dual-energy x-ray absorptiometry (DXA) scans are a critical population health tool and relatively simple to interpret but can be time consuming to report, often requiring manual transfer of bone mineral density and associated statistics into commercially available dictation systems. We describe here a custom-built computer program for automated reporting of DXA scans using Pydicom, an open-source package built in the Python computer language, and regular expressions to mine DICOM tags for patient information and bone mineral density statistics. This program, easy to emulate by any novice computer programmer, has doubled our efficiency at reporting DXA scans and has eliminated dictation errors.

Cortical Matrix Mineral Density Measured Non-invasively in Pre- and Postmenopausal Women and a Woman with Vitamin D Dependent Rickets.

PubMed

Chiang, Cherie Y; Zebaze, Roger; Wang, Xiao-Fang; Ghasem-Zadeh, Ali; Zajac, Jeffrey D; Seeman, Ego

2018-02-28

Reduced bone mineral density (BMD) may be due to reduced mineralized bone matrix volume, incomplete secondary mineralization or reduced primary mineralization. As bone biopsy is invasive, we hypothesized that non-invasive image acquisition at high resolution can accurately quantify matrix mineral density (MMD). Quantification of MMD was confined to voxels attenuation photons above 80% of that produced by fully mineralized bone matrix because attenuation at this level is due to variation in mineralization not porosity. To assess accuracy, 9 cadaveric distal radii were imaged at a voxel size of 82 microns using high resolution peripheral quantitative computed tomography (HR-pQCT, XtremeCT, Scanco Medical AG, Switzerland) and compared with VivaCT 40 (µCT) at 19 microns voxel size. Associations between MMD and porosity were studied in 94 heathy vitamin D replete pre-menopausal, 77 post-menopausal women, and in a 27 year-old woman with vitamin-D Dependent Rickets (VDDR). Microstructure and MMD were quantified using StrAx (StraxCorp, Melbourne, Australia). MMD measured by HR-pQCT and µCT correlated (R = 0.87; p <0.0001). The precision error for MMD was 2.43%. Cortical porosity and MMD were associated with age (r 2  = 0.5 and - 0.4 respectively) and correlated inversely in pre- and post-menopausal women (both r 2  = 0.9, all p < 0.001). Porosity was higher, and MMD was lower, in post- than in pre-menopausal women (porosity 40.3% ± 7.0 versus 34.7% ± 3.5 respectively, MMD 65.4% ± 1.8 versus 66.6% ± 1.4 respectively, both p < 0.001). In the woman with VDDR, MMD was 5.6 SD lower, and porosity was 5.6 SD higher, than the respective trait means in premenopausal women. BMD was reduced (Z scores femoral neck - 4.3 SD, lumbar spine - 3.8 SD). Low radiation HR-pQCT may facilitate non-invasive quantification of bone's MMD and microstructure in health, disease and during treatment. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Relationship between bone mineral density, weight, and estrogen levels in pre and postmenopausal women.

PubMed

Corina, Morcov; Vulpoi, Carmen; Brănişteanu, D

2012-01-01

Bone loss in postmenopausal women is mainly due to estrogen deficiency affecting the balance between osteoclast resorption and bone formation controlled by osteoblasts. To determine the relationship between bone mineral density (BMD) in pre and postmenopausal Caucasian women, and estrogen levels. Cross-sectional study including six groups of 8 to 15 pre- and postmenopausal healthy volunteers with different weights, body mass index (BMI) (normal or underweight < 25 kg/m2, overweight 25-30 kg/m2, and obese > 30 kg/m2), not exposed to antiosteoporotic therapy. Lumbar bone mineral density (BMD) and body composition (BC) were evaluated by dual X ray absorptiometry (DXA, Hologic), while serum estradiol and estrone were measured by ELISA. BMD in postmenopausal women is lower than in premenopausal women irrespective of body weight (p<0.05). Estradiol and estrone are positively correlate with bone mass in premenopausal women, but not in postmenopausal women (R2 0.3209, R2 0.2579, respectively). It is very important to identify the risk factors for osteoporosis, especially in postmenopausal women, as we will show that aromatization of androgens into estrogens in adipose tissue appears not to have a significant role in postmenopausal women bone protection. Key-

Veganism, bone mineral density, and body composition: a study in Buddhist nuns.

PubMed

Ho-Pham, L T; Nguyen, P L T; Le, T T T; Doan, T A T; Tran, N T; Le, T A; Nguyen, T V

2009-12-01

This cross-sectional study showed that, although vegans had lower dietary calcium and protein intakes than omnivores, veganism did not have adverse effect on bone mineral density and did not alter body composition. Whether a lifelong vegetarian diet has any negative effect on bone health is a contentious issue. We undertook this study to examine the association between lifelong vegetarian diet and bone mineral density and body composition in a group of postmenopausal women. One hundred and five Mahayana Buddhist nuns and 105 omnivorous women (average age = 62, range = 50-85) were randomly sampled from monasteries in Ho Chi Minh City and invited to participate in the study. By religious rule, the nuns do not eat meat or seafood (i.e., vegans). Bone mineral density (BMD) at the lumbar spine (LS), femoral neck (FN), and whole body (WB) was measured by DXA (Hologic QDR 4500). Lean mass, fat mass, and percent fat mass were also obtained from the DXA whole body scan. Dietary calcium and protein intakes were estimated from a validated food frequency questionnaire. There was no significant difference between vegans and omnivores in LSBMD (0.74 +/- 0.14 vs. 0.77 +/- 0.14 g/cm(2); mean +/- SD; P = 0.18), FNBMD (0.62 +/- 0.11 vs. 0.63 +/- 0.11 g/cm(2); P = 0.35), WBBMD (0.88 +/- 0.11 vs. 0.90 +/- 0.12 g/cm(2); P = 0.31), lean mass (32 +/- 5 vs. 33 +/- 4 kg; P = 0.47), and fat mass (19 +/- 5 vs. 19 +/- 5 kg; P = 0.77) either before or after adjusting for age. The prevalence of osteoporosis (T scores < or = -2.5) at the femoral neck in vegans and omnivores was 17.1% and 14.3% (P = 0.57), respectively. The median intake of dietary calcium was lower in vegans compared to omnivores (330 +/- 205 vs. 682 +/- 417 mg/day, P < 0.001); however, there was no significant correlation between dietary calcium and BMD. Further analysis suggested that whole body BMD, but not lumbar spine or femoral neck BMD, was positively correlated with the ratio of animal protein to vegetable protein. These results suggest that, although vegans have much lower intakes of dietary calcium and protein than omnivores, veganism does not have adverse effect on bone mineral density and does not alter body composition.

High protein consumption in trained women: bad to the bone?

PubMed

Antonio, Jose; Ellerbroek, Anya; Evans, Cassandra; Silver, Tobin; Peacock, Corey A

2018-01-01

It has been posited that the consumption of extra protein (> 0.8 g/kg/d) may be deleterious to bone mineral content. However, there is no direct evidence to show that consuming a high-protein diet results in a demineralization of the skeleton. Thus, the primary endpoint of this randomized controlled trial was to determine if a high-protein diet affected various parameters of whole body and lumbar bone mineral content in exercise-trained women. Twenty-four women volunteered for this 6-month investigation ( n  = 12 control, n = 12 high-protein). The control group was instructed to consume their habitual diet; however, the high-protein group was instructed to consume ≥2.2 g of protein per kilogram body weight daily (g/kg/d). Body composition was assessed via dual-energy x-ray absorptiometry (DXA). Subjects were instructed to keep a food diary via the mobile app MyFitnessPal ® . Exercise or activity level was not controlled. Subjects were asked to maintain their current levels of exercise. During the 6-month treatment period, there was a significant difference in protein intake between the control and high-protein groups (mean±SD; control: 1.5±0.3, high-protein: 2.8±1.1 g/kg/d); however, there were no differences in the consumption total calories, carbohydrate or fat. Whole body bone mineral density did not change in the control (pre: 1.22±0.08, post: 1.22±0.09 g/cm 2 ) or high-protein group (pre: 1.25±0.11, post: 1.24±0.10 g/cm 2 ). Similarly, lumbar bone mineral density did not change in the control (pre: 1.08±0.16, post: 1.05±0.13 g/cm 2 ) or high-protein group (pre: 1.07±0.11, post: 1.08±0.12 g/cm 2 ). In addition, there were no changes in whole body or lumbar T-Scores in either group. Furthermore, there were no changes in fat mass or lean body mass. Despite an 87% higher protein intake (high-protein versus control), 6 months of a high-protein diet had no effect on whole body bone mineral density, lumbar bone mineral density, T-scores, lean body mass or fat mass.

The effects of visceral obesity and androgens on bone: trenbolone protects against loss of femoral bone mineral density and structural strength in viscerally obese and testosterone-deficient male rats.

PubMed

Donner, D G; Elliott, G E; Beck, B R; Forwood, M R; Du Toit, E F

2016-03-01

In males, visceral obesity and androgen deficiency often present together and result in harmful effects on bone. Our findings show that both factors are independently associated with adverse effects on femoral bone structure and strength, and trenbolone protects rats from diet-induced visceral obesity and consequently normalises femoral bone structural strength. In light of the rapidly increasing incidence of obesity and osteoporosis globally, and recent conjecture regarding the effects of visceral adiposity and testosterone deficiency on bone health, we investigated the effects of increased visceral adipose tissue (VAT) mass on femoral bone mineral density (BMD), structure and strength in normal weight rats with testosterone deficiency. Male Wistar rats (n = 50) were fed either standard rat chow (CTRL, n = 10) or a high-fat/high-sugar diet (HF/HS, n = 40). Following 8 weeks of feeding, rats underwent sham surgery (CTRL, n = 10; HF/HS, n = 10) or orchiectomy (HF/HS + ORX, n = 30). Following a 4-week recovery period, mini-osmotic pumps containing either vehicle (CTRL, n = 10; HF/HS, n = 10; HF/HS + ORX, n = 10), 2.0 mg kg day(-1), testosterone (HF/HS + ORX + TEST, n = 10) or 2.0 mg kg day(-1) trenbolone (HF/HS + ORX + TREN, n = 10) were implanted for 8 weeks of treatment. Dual-energy X-ray absorptiometry and three-point bending tests were used to assess bone mass, structure and strength of femora. Diet-induced visceral obesity resulted in decreased bone mineral area (BMA) and content (BMC) and impaired femoral stiffness and strength. Orchiectomy further impaired BMA, BMC and BMD and reduced energy to failure in viscerally obese animals. Both TEST and TREN treatment restored BMA, BMC, BMD and energy to failure. Only TREN reduced visceral adiposity and improved femoral stiffness and strength. Findings support a role for both visceral adiposity and testosterone deficiency as independent risk factors for femoral osteoporosis, adverse bone geometry and impaired bone strength in male rats. Trenbolone may be a more effective candidate for androgen replacement therapy than testosterone in viscerally obese testosterone-deficient males.

Field device to measure viscosity, density, and other slurry properties in drilled shafts : final report.

DOT National Transportation Integrated Search

2016-04-01

Proper performance of mineral slurries used to stabilize drilled shaft excavations is maintained by assuring the : density, viscosity, pH, and sand content stay within state specified limits. These limits have been set either by : past experience, re...