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.

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.

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).

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

[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.

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

[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.

Sex-related differences of bone properties of pelvic limb and bone metabolism indices in 14-month-old ostriches (Struthio camelus).

PubMed

Krupski, W; Tatara, M R; Charuta, A; Brodzki, A; Szpetnar, M; Jóźwik, A; Strzałkowska, N; Poławska, E; Łuszczewska-Sierakowska, I

2018-06-01

1. Sex-related differences of long pelvic limb bones and serum bone metabolism indices were evaluated in 14-month-old female (N = 7) and male (N = 7) ostriches of similar body weights. 2. Densitometric parameters of femur, tibia and tarsometatarsus were determined using quantitative computed tomography (volumetric bone mineral density, calcium hydroxyapatite density and mean volumetric bone mineral density) and dual energy X-ray absorptiometry (bone mineral density and bone mineral content) methods. Geometrical parameters such as cortical bone area, cross-sectional area, second moment of inertia, mean relative wall thickness and cortical index were determined in the midshaft of bones. Mechanical properties of bones (maximum elastic strength and ultimate strength) were evaluated using three-point bending test. Serum concentrations of free amino acids, osteocalcin, N-terminal propeptide of type I procollagen, C-terminal telopeptides of type II collagen and total antioxidative capacity were also determined. 3. Bone weight and relative bone weight of all bones were significantly higher in males than in females. Significantly lower values of trabecular bone mineral density and calcium hydroxyapatite density were found in the trabecular bone of tibia in males. The highest number of the sex-related differences was observed in the tarsometatarsus where bone length, bone mineral content, cortical bone area, cross-sectional area and ultimate strength were higher in males. Serum concentrations of taurine, hydroxyproline, valine and isoleucine were significantly higher in males. 4. Higher loading of the tarsometatarsus in comparison to femur and tibia may be an important factor interacting with sex hormones in regulation of bone formation and mineralisation processes. Sex-related differences of bone properties were associated with increased serum concentration of selected amino acids in males.

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.

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

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.

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

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.

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.

Height adjustment in assessing dual energy x-ray absorptiometry measurements of bone mass and density in children.

PubMed

Zemel, Babette S; Leonard, Mary B; Kelly, Andrea; Lappe, Joan M; Gilsanz, Vicente; Oberfield, Sharon; Mahboubi, Soroosh; Shepherd, John A; Hangartner, Thomas N; Frederick, Margaret M; Winer, Karen K; Kalkwarf, Heidi J

2010-03-01

In children, bone mineral content (BMC) and bone mineral density (BMD) measurements by dual-energy x-ray absorptiometry (DXA) are affected by height status. No consensus exists on how to adjust BMC or BMD (BMC/BMD) measurements for short or tall stature. The aim of this study was to compare various methods to adjust BMC/BMD for height in healthy children. Data from the Bone Mineral Density in Childhood Study (BMDCS) were used to develop adjustment methods that were validated using an independent cross-sectional sample of healthy children from the Reference Data Project (RDP). We conducted the study in five clinical centers in the United States. We included 1546 BMDCS and 650 RDP participants (7 to 17 yr of age, 50% female). No interventions were used. We measured spine and whole body (WB) BMC and BMD Z-scores for age (BMC/BMD(age)), height age (BMC/BMD(height age)), height (BMC(height)), bone mineral apparent density (BMAD(age)), and height-for-age Z-score (HAZ) (BMC/BMD(haz)). Spine and WB BMC/BMD(age)Z and BMAD(age)Z were positively (P < 0.005; r = 0.11 to 0.64) associated with HAZ. Spine BMD(haz) and BMC(haz)Z were not associated with HAZ; WB BMC(haz)Z was modestly associated with HAZ (r = 0.14; P = 0.0003). All other adjustment methods were negatively associated with HAZ (P < 0.005; r = -0.20 to -0.34). The deviation between adjusted and BMC/BMD(age) Z-scores was associated with age for most measures (P < 0.005) except for BMC/BMD(haz). Most methods to adjust BMC/BMD Z-scores for height were biased by age and/or HAZ. Adjustments using HAZ were least biased relative to HAZ and age and can be used to evaluate the effect of short or tall stature on BMC/BMD Z-scores.

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

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

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.

Longitudinal changes in femur bone mineral density after spinal cord injury: effects of slice placement and peel method

PubMed Central

Dudley-Javoroski, S.

2010-01-01

Summary Surveillance of femur metaphysis bone mineral density (BMD) decline after spinal cord injury (SCI) may be subject to slice placement error of 2.5%. Adaptations to anti-osteoporosis measures should exceed this potential source of error. Image analysis parameters likewise affect BMD output and should be selected strategically in longitudinal studies. Introduction Understanding the longitudinal changes in bone mineral density (BMD) after spinal cord injury (SCI) is important when assessing new interventions. We determined the longitudinal effect of SCI on BMD of the femur metaphysis. To facilitate interpretation of longitudinal outcomes, we (1) determined the BMD difference associated with erroneous peripheral quantitative computed tomography (pQCT) slice placement, and (2) determined the effect of operator-selected pQCT peel algorithms on BMD. Methods pQCT images were obtained from the femur metaphysis (12% of length from distal end) of adult subjects with and without SCI. Slice placement errors were simulated at 3 mm intervals and were processed in two ways (threshold-based vs. concentric peel). Results BMD demonstrated a rapid decline over 2 years post-injury. BMD differences attributable to operator-selected peel methods were large (17.3% for subjects with SCI). Conclusions Femur metaphysis BMD declines after SCI in a manner similar to other anatomic sites. Concentric (percentage-based) peel methods may be most appropriate when special sensitivity is required to detect BMD adaptations. Threshold-based methods may be more appropriate when asymmetric adaptations are observed. PMID:19707702

Interpreting spectral unmixing coefficients: From spectral weights to mass fractions

NASA Astrophysics Data System (ADS)

Grumpe, Arne; Mengewein, Natascha; Rommel, Daniela; Mall, Urs; Wöhler, Christian

2018-01-01

It is well known that many common planetary minerals exhibit prominent absorption features. Consequently, the analysis of spectral reflectance measurements has become a major tool of remote sensing. Quantifying the mineral abundances, however, is not a trivial task. The interaction between the incident light rays and particulate surfaces, e.g., the lunar regolith, leads to a non-linear relationship between the reflectance spectra of the pure minerals, the so-called ;endmembers;, and the surface's reflectance spectrum. It is, however, possible to transform the non-linear reflectance mixture into a linear mixture of single-scattering albedos of the Hapke model. The abundances obtained by inverting the linear single-scattering albedo mixture may be interpreted as volume fractions which are weighted by the endmember's extinction coefficient. Commonly, identical extinction coefficients are assumed throughout all endmembers and the obtained volume fractions are converted to mass fractions using either measured or assumed densities. In theory, the proposed method may cover different grain sizes if each grain size range of a mineral is treated as a distinct endmember. Here, we present a method to transform the mixing coefficients to mass fractions for arbitrary combinations of extinction coefficients and densities. The required parameters are computed from reflectance measurements of well defined endmember mixtures. Consequently, additional measurements, e.g., the endmember density, are no longer required. We evaluate the method based on laboratory measurements and various results presented in the literature, respectively. It is shown that the procedure transforms the mixing coefficients to mass fractions yielding an accuracy comparable to carefully calibrated laboratory measurements without additional knowledge. For our laboratory measurements, the square root of the mean squared error is less than 4.82 wt%. In addition, the method corrects for systematic effects originating from mixtures of endmembers showing a highly varying albedo, e.g., plagioclase and pyroxene.

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.

Bone geometry, structure and mineral distribution using Dual energy X ray Absorptiometry (DXA)

NASA Technical Reports Server (NTRS)

Whalen, Robert; Cleek, Tammy

1993-01-01

Dual energy x-ray absorptiometry (DXA) is currently the most widely used method of analyzing regional and whole body changes in bone mineral content (BMC) and areal (g/sq cm) bone mineral density (BMD). However, BMC and BMD do not provide direct measures of long bone geometry, structure, or strength nor do regional measurements detect localized changes in other regions of the same bone. The capabilities of DXA can be enhanced significantly by special processing of pixel BMC data which yields cross-sectional geometric and structural information. We have extended this method of analysis in order to develop non-uniform structural beam models of long bones.

Singularity analysis based on wavelet transform of fractal measures for identifying geochemical anomaly in mineral exploration

NASA Astrophysics Data System (ADS)

Chen, Guoxiong; Cheng, Qiuming

2016-02-01

Multi-resolution and scale-invariance have been increasingly recognized as two closely related intrinsic properties endowed in geofields such as geochemical and geophysical anomalies, and they are commonly investigated by using multiscale- and scaling-analysis methods. In this paper, the wavelet-based multiscale decomposition (WMD) method was proposed to investigate the multiscale natures of geochemical pattern from large scale to small scale. In the light of the wavelet transformation of fractal measures, we demonstrated that the wavelet approximation operator provides a generalization of box-counting method for scaling analysis of geochemical patterns. Specifically, the approximation coefficient acts as the generalized density-value in density-area fractal modeling of singular geochemical distributions. Accordingly, we presented a novel local singularity analysis (LSA) using the WMD algorithm which extends the conventional moving averaging to a kernel-based operator for implementing LSA. Finally, the novel LSA was validated using a case study dealing with geochemical data (Fe2O3) in stream sediments for mineral exploration in Inner Mongolia, China. In comparison with the LSA implemented using the moving averaging method the novel LSA using WMD identified improved weak geochemical anomalies associated with mineralization in covered area.

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.

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.

[Practice of martial arts and bone mineral density in adolescents of both sexes].

PubMed

Ito, Igor Hideki; Mantovani, Alessandra Madia; Agostinete, Ricardo Ribeiro; Costa Junior, Paulo; Zanuto, Edner Fernando; Christofaro, Diego Giulliano Destro; Ribeiro, Luis Pedro; Fernandes, Rômulo Araújo

2016-06-01

The purpose of this study was to analyze the relationship between martial arts practice (judo, karate and kung-fu) and bone mineral density in adolescents. The study was composed of 138 (48 martial arts practitioners and 90 non-practitioners) adolescents of both sexes, with an average age of 12.6 years. Bone mineral density was measured using Dual-Energy X-ray Absorptiometry in arms, legs, spine, trunk, pelvis and total. Weekly training load and previous time of engagement in the sport modality were reported by the coach. Partial correlation tested the association between weekly training load and bone mineral density, controlled by sex, chronological age, previous practice and somatic maturation. Analysis of covariance was used to compare bone mineral density values according to control and martial arts groups, controlled by sex, chronological age, previous practice and somatic maturation. Significant relationships between bone mineral density and muscle mass were inserted into a multivariate model and the slopes of the models were compared using the Student t test (control versus martial art). Adolescents engaged in judo practice presented higher values of bone mineral density than the control individuals (p-value=0.042; Medium Effect size [Eta-squared=0.063]), while the relationship between quantity of weekly training and bone mineral density was significant among adolescents engaged in judo (arms [r=0.308] and legs [r=0.223]) and kung-fu (arms [r=0.248] and spine [r=0.228]). Different modalities of martial arts are related to higher bone mineral density in different body regions among adolescents. Copyright © 2015 Sociedade de Pediatria de São Paulo. Publicado por Elsevier Editora Ltda. All rights reserved.

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.

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 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.

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.

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

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.

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.

Dual Energy X-Ray Densitometry Apparatus and Method Using Single X-Ray Pulse

DTIC Science & Technology

1999-10-13

future bone fracture risk. Bone mineral loss is associated with aging and is more rapid in post-menopausal women. In addition, bone mineral loss is... parameters of the x-ray tube of Figures 1 and 2 illustrating, respectively, the calculated current, voltage and power; and Figures 4(a) and 4(d) are...assumed to be that of water. The bone mineral is hydroxyapatite (Ca5P30i3H) with an assumed density of 0.25 g/cm3 based on the lumbar vertebra metrology

Organic C and N stabilization in a forest soil: evidence from sequential density fractionation

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

Sollins, P; Swanston, C; Kleber, M

2005-07-15

In mineral soil, organic matter (OM) accumulates mainly on and around surfaces of silt- and clay-size particles. When fractionated according to particle density, C and N concentration (per g fraction) and C/N of these soil organo-mineral particles decrease with increasing particle density across soils of widely divergent texture, mineralogy, location, and management. The variation in particle density is explained potentially by two factors: (1) a decrease in the mass ratio of organic to mineral phase of these particles, and (2) variations in density of the mineral phase. The first explanation implies that the thickness of the organic accumulations decreases withmore » increasing particle density. The decrease in C/N can be explained at least partially by especially stable sorption of cationic peptidic compounds (amine, amide, and pyrrole) directly to mineral surfaces, a phenomenon well documented both empirically and theoretically. These peptidic compounds, along with ligand-exchanged carboxylic compounds, could then form a stable inner organic layer onto which less polar organics could sorb more readily than onto the highly charged mineral surfaces (''onion'' layering model). To explore mechanisms underlying this trend in C concentration and C/N with particle density, we sequentially density fractionated an Oregon andic soil at 1.65, 1.85, 2.00, 2.28, and 2.55 g cm{sup -3} and analyzed the six fractions for measures of organic matter and mineral phase properties. All measures of OM composition showed either: (1) a monotonic change with density, or (2) a monotonic change across the lightest fractions, then little change over the heaviest fractions. Total C, N, and lignin phenol concentration all decreased monotonically with increasing density, and {sup 14}C mean residence time (MRT) increased with particle density from ca. 150 y to >980 y in the four organo-mineral fractions. In contrast, C/N, {sup 13}C and {sup 15}N concentration all showed the second pattern. All these data are consistent with a general pattern of an increase in extent of microbial processing with increasing organo-mineral particle density, and also with an ''onion'' layering model. X-ray diffraction before and after separation of magnetic materials showed that the sequential density fractionation isolated pools of differing mineralogy, with layer-silicate clays dominating in two of the intermediate fractions and primary minerals in the heaviest two fractions. There was no indication that these differences in mineralogy controlled the differences in density of the organo-mineral particles in this soil. Thus, our data are consistent with the hypothesis that variation in particle density reflects variation in thickness of the organic accumulations and with an ''onion'' layering model for organic matter accumulation on mineral surfaces. However, the mineralogy differences among fractions made it difficult to test either the layer-thickness or ''onion'' layering models with this soil. Although sequential density fractionation isolated pools of distinct mineralogy and organic-matter composition, more work will be needed to understand mechanisms relating the two factors.« less

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.

A nonlinear controlling function of geological features on magmatic–hydrothermal mineralization

PubMed Central

Zuo, Renguang

2016-01-01

This paper reports a nonlinear controlling function of geological features on magmatic–hydrothermal mineralization, and proposes an alternative method to measure the spatial relationships between geological features and mineral deposits using multifractal singularity theory. It was observed that the greater the proximity to geological controlling features, the greater the number of mineral deposits developed, indicating a nonlinear spatial relationship between these features and mineral deposits. This phenomenon can be quantified using the relationship between the numbers of mineral deposits N(ε) of a D-dimensional set and the scale of ε. The density of mineral deposits can be expressed as ρ(ε) = Cε−(De−a), where ε is the buffer width of geological controlling features, De is Euclidean dimension of space (=2 in this case), a is singularity index, and C is a constant. The expression can be rewritten as ρ = Cεa−2. When a < 2, there is a significant spatial correlation between specific geological features and mineral deposits; lower a values indicate a more significant spatial correlation. This nonlinear relationship and the advantages of this method were illustrated using a case study from Fujian Province in China and a case study from Baguio district in Philippines. PMID:27255794

A nonlinear controlling function of geological features on magmatic-hydrothermal mineralization.

PubMed

Zuo, Renguang

2016-06-03

This paper reports a nonlinear controlling function of geological features on magmatic-hydrothermal mineralization, and proposes an alternative method to measure the spatial relationships between geological features and mineral deposits using multifractal singularity theory. It was observed that the greater the proximity to geological controlling features, the greater the number of mineral deposits developed, indicating a nonlinear spatial relationship between these features and mineral deposits. This phenomenon can be quantified using the relationship between the numbers of mineral deposits N(ε) of a D-dimensional set and the scale of ε. The density of mineral deposits can be expressed as ρ(ε) = Cε(-(De-a)), where ε is the buffer width of geological controlling features, De is Euclidean dimension of space (=2 in this case), a is singularity index, and C is a constant. The expression can be rewritten as ρ = Cε(a-2). When a < 2, there is a significant spatial correlation between specific geological features and mineral deposits; lower a values indicate a more significant spatial correlation. This nonlinear relationship and the advantages of this method were illustrated using a case study from Fujian Province in China and a case study from Baguio district in Philippines.

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

Comparison of radiograph-based texture analysis and bone mineral density with three-dimensional microarchitecture of trabecular bone.

PubMed

Ranjanomennahary, P; Ghalila, S Sevestre; Malouche, D; Marchadier, A; Rachidi, M; Benhamou, Cl; Chappard, C

2011-01-01

Hip fracture is a serious health problem and textural methods are being developed to assess bone quality. The authors aimed to perform textural analysis at femur on high-resolution digital radiographs compared to three-dimensional (3D) microarchitecture comparatively to bone mineral density. Sixteen cadaveric femurs were imaged with an x-ray device using a C-MOS sensor. One 17 mm square region of interest (ROI) was selected in the femoral head (FH) and one in the great trochanter (GT). Two-dimensional (2D) textural features from the co-occurrence matrices were extracted. Site-matched measurements of bone mineral density were performed. Inside each ROI, a 16 mm diameter core was extracted. Apparent density (Dapp) and bone volume proportion (BV/TV(Arch)) were measured from a defatted bone core using Archimedes' principle. Microcomputed tomography images of the entire length of the core were obtained (Skyscan 1072) at 19.8 microm of resolution and usual 3D morphometric parameters were computed on the binary volume after calibration from BV/TV(Arch). Then, bone surface/bone volume, trabecular thickness, trabecular separation, and trabecular number were obtained by direct methods without model assumption and the structure model index was calculated. In univariate analysis, the correlation coefficients between 2D textural features and 3D morphological parameters reached 0.83 at the FH and 0.79 at the GT. In multivariate canonical correlation analysis, coefficients of the first component reached 0.95 at the FH and 0.88 at the GT. Digital radiographs, widely available and economically viable, are an alternative method for evaluating bone microarchitectural structure.

Implementation of Biofilm Permeability Models for Mineral Reactions in Saturated Porous Media

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

Freedman, Vicky L.; Saripalli, Kanaka P.; Bacon, Diana H.

2005-02-22

An approach based on continuous biofilm models is proposed for modeling permeability changes due to mineral precipitation and dissolution in saturated porous media. In contrast to the biofilm approach, implementation of the film depositional models within a reactive transport code requires a time-dependent calculation of the mineral films in the pore space. Two different methods for this calculation are investigated. The first method assumes a direct relationship between changes in mineral radii (i.e., surface area) and changes in the pore space. In the second method, an effective change in pore radii is calculated based on the relationship between permeability andmore » grain size. Porous media permeability is determined 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. Results from single mineral dissolution and single mineral precipitation simulations provide reasonable estimates of permeability, though they under predict the magnitude of permeability changes relative to the Kozeny and Carmen model. However, a comparison of experimental and simulated data show that the Mualem film model is the only one that can replicate the oscillations in permeability that occur as a result of simultaneous dissolution and precipitation reactions occurring within the porous media.« less

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

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.

TL and ESR based identification of gamma-irradiated frozen fish using different hydrolysis techniques

NASA Astrophysics Data System (ADS)

Ahn, Jae-Jun; Akram, Kashif; Shahbaz, Hafiz Muhammad; Kwon, Joong-Ho

2014-12-01

Frozen fish fillets (walleye Pollack and Japanese Spanish mackerel) were selected as samples for irradiation (0-10 kGy) detection trials using different hydrolysis methods. Photostimulated luminescence (PSL)-based screening analysis for gamma-irradiated frozen fillets showed low sensitivity due to limited silicate mineral contents on the samples. Same limitations were found in the thermoluminescence (TL) analysis on mineral samples isolated by density separation method. However, acid (HCl) and alkali (KOH) hydrolysis methods were effective in getting enough minerals to carry out TL analysis, which was reconfirmed through the normalization step by calculating the TL ratios (TL1/TL2). For improved electron spin resonance (ESR) analysis, alkali and enzyme (alcalase) hydrolysis methods were compared in separating minute-bone fractions. The enzymatic method provided more clear radiation-specific hydroxyapatite radicals than that of the alkaline method. Different hydrolysis methods could extend the application of TL and ESR techniques in identifying the irradiation history of frozen fish fillets.

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.

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.

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.

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.

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

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.

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.

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.

Osteoprotegerin autoantibodies do not predict low bone mineral density in middle-aged women.

PubMed

Vaziri-Sani, Fariba; Brundin, Charlotte; Agardh, Daniel

2017-12-01

Autoantibodies against osteoprotegerin (OPG) have been associated with osteoporosis. The aim was to develop an immunoassay for OPG autoantibodies and test their diagnostic usefulness of identifying women general population with low bone mineral density. Included were 698 women at mean age 55.1 years (range 50.4-60.6) randomly selected from the general population. Measurement of wrist bone mineral density (g/cm 2 ) was performed of the non-dominant wrist by dual-energy X-ray absorptiometry (DXA). A T-score < - 2.5 was defined as having a low bone mineral density. Measurements of OPG autoantibodies were carried by radiobinding assays. Cut-off levels for a positive value were determined from the deviation from normality in the distribution of 398 healthy blood donors representing the 99.7th percentile. Forty-five of the 698 (6.6%) women were IgG-OPG positive compared with 2 of 398 (0.5%) controls ( p  < 0.0001) and 35 of the 698 (5.0%) women had a T-score < - 2.5. There was no difference in bone mineral density between IgG-OPG positive (median 0.439 (range 0.315-0.547) g/cm 2 ) women and IgG-OPG negative (median 0.435 (range 0.176-0.652) g/cm 2 ) women ( p  = 0.3956). Furthermore, there was neither a correlation between IgG-OPG levels and bone mineral density (r s  = 0.1896; p  = 0.2068) nor T-score (r s  = 0.1889; p  = 0.2086). Diagnostic sensitivity and specificity of IgG-OPG for low bone mineral density were 5.7% and 92.9%, and positive and negative predictive values were 7.4% and 90.8%, respectively. Elevated OPG autoantibody levels do not predict low bone mineral density in middle-aged women selected from the general population.

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.

Positive association between mammographic breast density and bone mineral density in the Postmenopausal Estrogen/Progestin Interventions Study

PubMed Central

Crandall, Carolyn; Palla, Shana; Reboussin, Beth A; Ursin, Giske; Greendale, Gail A

2005-01-01

Introduction Mammographic breast density is a strong independent risk factor for breast cancer. We hypothesized that demonstration of an association between mammographic breast density and bone mineral density (BMD) would suggest a unifying underlying mechanism influencing both breast density and BMD. Methods In a cross-sectional analysis of baseline data from the Postmenopausal Estrogen/Progestin Interventions Study (PEPI), participants were aged 45 to 64 years and were at least 1 year postmenopausal. Mammographic breast density (percentage of the breast composed of dense tissue), the outcome, was assessed with a computer-assisted percentage-density method. BMD, the primary predictor, was measured with dual-energy X-ray absorptiometry. Women quitting menopausal hormone therapy to join PEPI were designated recent hormone users. Results The mean age of the 594 women was 56 years. The average time since menopause was 5.6 years. After adjustment for age, body mass index, and cigarette smoking, in women who were not recent hormone users before trial enrollment (n = 415), mammographic density was positively associated with total hip (P = 0.04) and lumbar (P = 0.08) BMD. Mammographic density of recent hormone users (n = 171) was not significantly related to either total hip (P = 0.51) or lumbar (P = 0.44) BMD. In participants who were not recent hormone users, mammographic density was 4% greater in the highest quartile of total hip BMD than in the lowest. In participants who were not recent hormone users, mammographic density was 5% greater in the highest quartile of lumbar spine BMD than in the lowest. Conclusion Mammographic density and BMD are positively associated in women who have not recently used postmenopausal hormones. A unifying biological mechanism may link mammographic density and BMD. Recent exogenous postmenopausal hormone use may obscure the association between mammographic density and BMD by having a persistent effect on breast tissue. PMID:16280044

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.

[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.

Ptychographic X-ray nanotomography quantifies mineral distributions in human dentine

NASA Astrophysics Data System (ADS)

Zanette, I.; Enders, B.; Dierolf, M.; Thibault, P.; Gradl, R.; Diaz, A.; Guizar-Sicairos, M.; Menzel, A.; Pfeiffer, F.; Zaslansky, P.

2015-03-01

Bones are bio-composites with biologically tunable mechanical properties, where a polymer matrix of nanofibrillar collagen is reinforced by apatite mineral crystals. Some bones, such as antler, form and change rapidly, while other bone tissues, such as human tooth dentine, develop slowly and maintain constant composition and architecture for entire lifetimes. When studying apatite mineral microarchitecture, mineral distributions or mineralization activity of bone-forming cells, representative samples of tissue are best studied at submicrometre resolution while minimizing sample-preparation damage. Here, we demonstrate the power of ptychographic X-ray tomography to map variations in the mineral content distribution in three dimensions and at the nanometre scale. Using this non-destructive method, we observe nanostructures surrounding hollow tracts that exist in human dentine forming dentinal tubules. We reveal unprecedented quantitative details of the ultrastructure clearly revealing the spatially varying mineralization density. Such information is essential for understanding a variety of natural and therapeutic effects for example in bone tissue healing and ageing.

Paracrystalline Disorder from Phosphate Ion Orientation and Substitution in Synthetic Bone Mineral.

PubMed

Marisa, Mary E; Zhou, Shiliang; Melot, Brent C; Peaslee, Graham F; Neilson, James R

2016-12-05

Hydroxyapatite is an inorganic mineral closely resembling the mineral phase in bone. However, as a biological mineral, it is highly disordered, and its composition and atomistic structure remain poorly understood. Here, synchrotron X-ray total scattering and pair distribution function analysis methods provide insight into the nature of atomistic disorder in a synthetic bone mineral analogue, chemically substituted hydroxyapatite. By varying the effective hydrolysis rate and/or carbonate concentration during growth of the mineral, compounds with varied degrees of paracrystallinity are prepared. From advanced simulations constrained by the experimental pair distribution function and density functional theory, the paracrystalline disorder prevalent in these materials appears to result from accommodation of carbonate in the lattice through random displacement of the phosphate groups. Though many substitution modalities are likely to occur in concert, the most predominant substitution places carbonate into the mirror plane of an ideal phosphate site. Understanding the mineralogical imperfections of a biologically analogous hydroxyapatite is important not only to potential bone grafting applications but also to biological mineralization processes themselves.

[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.

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.

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.

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.

The Relationships between Two Different Drinking Water Fluoride Levels, Dental Fluorosis and Bone Mineral Density of Children

PubMed Central

Grobler, S.R; Louw, A.J; Chikte, U.M.E; Rossouw, R.J; van W Kotze, T.J.

2009-01-01

This field study included the whole population of children aged 10–15 years (77 from a 0.19 mg/L F area; 89 from a 3.00 mg/L F area), with similar nutritional, dietary habits and similar ethnic and socioeconomic status. The fluoride concentration in the drinking water, the bone mineral content, the bone density and the degree of dental fluorosis were determined. The left radius was measured for bone width, bone mineral content, and bone mineral density. The mean fluorosis score was 1.3 in the low fluoride area and 3,6 in the high fluoride area. More than half the children in the low fluoride area had no fluorosis (scores 0 and 1) while only 5% in the high fluoride area had none. Severe fluorosis (30%) was only observed in the high fluoride area. The Wilcoxon Rank Sum Test indicated that fluorosis levels differed significantly (p < 0.05) between the two areas. No relationships were found between dental fluorosis and bone width or between fluorosis and bone mineral density in the two areas (Spearment Rank correlations). A significant increase in bone width was found with age but no differences amongst and boys and girls. A significant positive correlation was found in the high fluoride area between bone mineral density over age. In the 12-13 and 13-14 year age groups in the high fluoride area, girls had higher bone mineral densities. However, a significant negative correlation (p<0.02) was found for the low fluoride area (0.19 mg/L F) over age. PMID:19444344

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.

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.

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.

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.

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.

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 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.

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

Preliminary research on dual-energy X-ray phase-contrast imaging

NASA Astrophysics Data System (ADS)

Han, Hua-Jie; Wang, Sheng-Hao; Gao, Kun; Wang, Zhi-Li; Zhang, Can; Yang, Meng; Zhang, Kai; Zhu, Pei-Ping

2016-04-01

Dual-energy X-ray absorptiometry (DEXA) has been widely applied to measure the bone mineral density (BMD) and soft-tissue composition of the human body. However, the use of DEXA is greatly limited for low-Z materials such as soft tissues due to their weak absorption, while X-ray phase-contrast imaging (XPCI) shows significantly improved contrast in comparison with the conventional standard absorption-based X-ray imaging for soft tissues. In this paper, we propose a novel X-ray phase-contrast method to measure the area density of low-Z materials, including a single-energy method and a dual-energy method. The single-energy method is for the area density calculation of one low-Z material, while the dual-energy method aims to calculate the area densities of two low-Z materials simultaneously. Comparing the experimental and simulation results with the theoretical ones, the new method proves to have the potential to replace DEXA in area density measurement. The new method sets the prerequisites for a future precise and low-dose area density calculation method for low-Z materials. Supported by Major State Basic Research Development Program (2012CB825800), Science Fund for Creative Research Groups (11321503) and National Natural Science Foundation of China (11179004, 10979055, 11205189, 11205157)

Genetic Sharing with Cardiovascular Disease Risk Factors and Diabetes Reveals Novel Bone Mineral Density Loci

PubMed Central

Thompson, Wesley K.; McEvoy, Linda K.; Schork, Andrew J.; Zuber, Verena; LeBlanc, Marissa; Bettella, Francesco; Mills, Ian G.; Desikan, Rahul S.; Djurovic, Srdjan; Gautvik, Kaare M.; Dale, Anders M.; Andreassen, Ole A.

2015-01-01

Bone Mineral Density (BMD) is a highly heritable trait, but genome-wide association studies have identified few genetic risk factors. Epidemiological studies suggest associations between BMD and several traits and diseases, but the nature of the suggestive comorbidity is still unknown. We used a novel genetic pleiotropy-informed conditional False Discovery Rate (FDR) method to identify single nucleotide polymorphisms (SNPs) associated with BMD by leveraging cardiovascular disease (CVD) associated disorders and metabolic traits. By conditioning on SNPs associated with the CVD-related phenotypes, type 1 diabetes, type 2 diabetes, systolic blood pressure, diastolic blood pressure, high density lipoprotein, low density lipoprotein, triglycerides and waist hip ratio, we identified 65 novel independent BMD loci (26 with femoral neck BMD and 47 with lumbar spine BMD) at conditional FDR < 0.01. Many of the loci were confirmed in genetic expression studies. Genes validated at the mRNA levels were characteristic for the osteoblast/osteocyte lineage, Wnt signaling pathway and bone metabolism. The results provide new insight into genetic mechanisms of variability in BMD, and a better understanding of the genetic underpinnings of clinical comorbidity. PMID:26695485

Optimizing care in osteoporosis: The Canadian quality circle project

PubMed Central

Ioannidis, George; Thabane, Lehana; Gafni, Amiram; Hodsman, Anthony; Kvern, Brent; Johnstone, Dan; Plumley, Nathalie; Salach, Lena; Jiwa, Famida; Adachi, Jonathan D; Papaioannou, Alexandra

2008-01-01

Background While the Osteoporosis Canada 2002 Canadian guidelines provided evidence based strategies in preventing, diagnosing, and managing this condition, publication and distribution of guidelines have not, in and of themselves, been shown to alter physicians clinical approaches. We hypothesize that primary care physicians enrolled in the Quality Circle project would change their patient management of osteoporosis in terms of awareness of osteoporosis risk factors and bone mineral density testing in accordance with the guidelines. Methods The project consisted of five Quality Circle phases that included: 1) Training & Baseline Data Collection, 2) First Educational Intervention & First Follow-Up Data Collection 3) First Strategy Implementation Session, 4) Final Educational Intervention & Final Follow-up Data Collection, and 5) Final Strategy Implementation Session. A total of 340 circle members formed 34 quality circles and participated in the study. The generalized estimating equations approach was used to model physician awareness of risk factors for osteoporosis and appropriate utilization of bone mineral density testing pre and post educational intervention (first year of the study). Odds ratios (OR) and 95% confidence intervals (95% CI) were calculated. Results After the 1st year of the study, physicians' certainty of their patients' risk factor status increased. Certainty varied from an OR of 1.4 (95% CI: 1.1, 1.8) for prior vertebral fracture status to 6.3 (95% CI: 2.3, 17.9) for prior hip fracture status. Furthermore, bone mineral density testing increased in high risk as compared with low risk patients (OR: 1.4; 95% CI: 1.2, 1.7). Conclusion Quality Circle methodology was successful in increasing both physicians' awareness of osteoporosis risk factors and appropriate bone mineral density testing in accordance with the 2002 Canadian guidelines. PMID:18828906

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

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

Osteoporosis, Fractures, and Diabetes

PubMed Central

2014-01-01

It is well established that osteoporosis and diabetes are prevalent diseases with significant associated morbidity and mortality. Patients with diabetes mellitus have an increased risk of bone fractures. In type 1 diabetes, the risk is increased by ∼6 times and is due to low bone mass. Despite increased bone mineral density (BMD), in patients with type 2 diabetes the risk is increased (which is about twice the risk in the general population) due to the inferior quality of bone. Bone fragility in type 2 diabetes, which is not reflected by bone mineral density, depends on bone quality deterioration rather than bone mass reduction. Thus, surrogate markers and examination methods are needed to replace the insensitivity of BMD in assessing fracture risks of T2DM patients. One of these methods can be trabecular bone score. The aim of the paper is to present the present state of scientific knowledge about the osteoporosis risk in diabetic patient. The review also discusses the possibility of problematic using the study conclusions in real clinical practice. PMID:25050121

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

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.

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.

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

PubMed

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

2005-12-01

Biomechanical studies of the thoracic spine often scan cadaveric segments by dual energy X-ray absorptiometry (DXA) to obtain measures of bone mass. Only one study has reported the accuracy of lateral scans of thoracic vertebral bodies. The accuracy of DXA scans of thoracic spine segments and of anterior-posterior (AP) thoracic scans has not been investigated. We have examined the accuracy of AP and lateral thoracic DXA scans by comparison with ash weight, the gold-standard for measuring bone mineral content (BMC). We have also compared three methods of estimating volumetric bone mineral density (vBMD) with a novel standard-ash weight (g)/bone volume (cm3) as measured by computed tomography (CT). Twelve T5-T8 spine segments were scanned with DXA (AP and lateral) and CT. The T6 vertebrae were excised, the posterior elements removed and then the vertebral bodies were ashed in a muffle furnace. We proposed a new method of estimating vBMD and compared it with two previously published methods. BMC values from lateral DXA scans displayed the strongest correlation with ash weight (r=0.99) and were on average 12.8% higher (p<0.001). As expected, BMC (AP or lateral) was more strongly correlated with ash weight than areal bone mineral density (aBMD; AP: r=0.54, or lateral: r=0.71) or estimated vBMD. Estimates of vBMD with either of the three methods were strongly and similarly correlated with volumetric BMD calculated by dividing ash weight by CT-derived volume. These data suggest that readily available DXA scanning is an appropriate surrogate measure for thoracic spine bone mineral and that the lateral scan might be the scan method of choice.

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.

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.

Combining coherent hard X-ray tomographies with phase retrieval to generate three-dimensional models of forming bone

NASA Astrophysics Data System (ADS)

Bortel, Emely L.; Langer, Max; Rack, Alexander; Forien, Jean-Baptiste; Duda, Georg N.; Fratzl, Peter; Zaslansky, Paul

2017-11-01

Holotomography, a phase sensitive synchrotron-based μCT modality, is a quantitative 3D imaging method. By exploiting partial spatial X-ray coherence, bones can be imaged volumetrically with high resolution coupled with impressive density sensitivity. This tomographic method reveals the main characteristics of the important tissue compartments in forming bones, including the rapidly-changing soft tissue and the partially or fully mineralized bone regions, while revealing subtle density differences in 3D. Here we show typical results observed within the growing femur bone midshafts of healthy mice that are 1, 3, 7, 10 and 14 days old (postpartum). Our results make use of partially-coherent synchrotron radiation employing inline Fresnel-propagation in multiple tomographic datasets obtained in the imaging beamline ID19 of the ESRF. The exquisite detail creates maps of the juxtaposed soft, partially mineralized and highly mineralized bone revealing the environment in which bone cells create and shape the matrix. This high resolution 3D data is a step towards creating realistic computational models that may be used to study the dynamic processes involved in bone tissue formation and adaptation. Such data will enhance our understanding of the important biomechanical interactions directing maturation and shaping of the bone micro- and macro-geometries.

Mapping Bone Mineral Density Obtained by Quantitative Computed Tomography to Bone Volume Fraction

NASA Technical Reports Server (NTRS)

Pennline, James A.; Mulugeta, Lealem

2017-01-01

Methods for relating or mapping estimates of volumetric Bone Mineral Density (vBMD) obtained by Quantitative Computed Tomography to Bone Volume Fraction (BVF) are outlined mathematically. The methods are based on definitions of bone properties, cited experimental studies and regression relations derived from them for trabecular bone in the proximal femur. Using an experimental range of values in the intertrochanteric region obtained from male and female human subjects, age 18 to 49, the BVF values calculated from four different methods were compared to the experimental average and numerical range. The BVF values computed from the conversion method used data from two sources. One source provided pre bed rest vBMD values in the intertrochanteric region from 24 bed rest subject who participated in a 70 day study. Another source contained preflight vBMD values from 18 astronauts who spent 4 to 6 months on the ISS. To aid the use of a mapping from BMD to BVF, the discussion includes how to formulate them for purpose of computational modeling. An application of the conversions would be used to aid in modeling of time varying changes in vBMD as it relates to changes in BVF via bone remodeling and/or modeling.

Electromagnetic field versus circuit weight training on bone mineral density in elderly women

PubMed Central

Elsisi, Hany Farid Eid Morsy; Mousa, Gihan Samir Mohamed; ELdesoky, Mohamed Taher Mahmoud

2015-01-01

Background and purpose Osteoporosis is a common skeletal disorder with costly complications and a global health problem and one of the leading causes of morbidity and mortality worldwide. Magnetic field therapy and physical activity have been proven as beneficial interventions for prevention and treatment of osteoporosis. The purpose of this study was to compare the response of bone mineral content and bone mineral density (BMD) in elderly women to either low-frequency low-intensity pulsed magnetic field (LFLIPMF) or circuit weight training (CWT) on short-run basis (after 12 weeks). Patients and methods Thirty elderly women, aged 60–70 years, were randomly assigned into two groups (magnetic field and CWT) (n=15 each group). The session was performed three times per week for magnetic field and CWT groups, for 12 weeks. BMD and bone mineral content of lumbar spine (L2–L4) and femoral neck, trochanter, and Ward’s triangle were evaluated before and after 12 weeks of treatment. Results Both magnetic field and CWT for 12 weeks in elderly women seem to yield beneficial and statistically significant increasing effect on BMD and bone mineral content (P<0.05). But magnetic field seems to have more beneficially and statistically significant effect than does CWT. Conclusion It is possible to conclude that LFLIPMF and CWT programs are effective modalities in increasing BMD but LFLIPMF is more effective in elderly women. PMID:25834412

[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

Paracrystalline Disorder from Phosphate Ion Orientation and Substitution in Synthetic Bone Mineral

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

Marisa, Mary E.; Zhou, Shiliang; Melot, Brent C.

Hydroxyapatite is an inorganic mineral closely resembling the mineral phase in bone. However, as a biological mineral, it is highly disordered, and its composition and atomistic structure remain poorly understood. Here, synchrotron X-ray total scattering and pair distribution function analysis methods provide insight into the nature of atomistic disorder in a synthetic bone mineral analogue, chemically substituted hydroxyapatite. By varying the effective hydrolysis rate and/or carbonate concentration during growth of the mineral, compounds with varied degrees of paracrystallinity are prepared. From advanced simulations constrained by the experimental pair distribution function and density functional theory, the paracrystalline disorder prevalent in thesemore » materials appears to result from accommodation of carbonate in the lattice through random displacement of the phosphate groups. Though many substitution modalities are likely to occur in concert, the most predominant substitution places carbonate into the mirror plane of an ideal phosphate site. Understanding the mineralogical imperfections of a biologically analogous hydroxyapatite is important not only to potential bone grafting applications but also to biological mineralization processes themselves.« less

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.

Incidence of Osteoporosis in Patients with Urolithiasis

PubMed Central

Bijelic, Radojka; Milicevic, Snjezana; Balaban, Jagoda

2014-01-01

ABSTRACT Introduction. Clinical researches have shown an increased bone disintegration and lower bone mass in patients with calcium urolithiasis. Goal. The goal of our research was to establish the incidence of osteoporosis in adult patients with calcium urolithiasis, on the basis of measuring mineral bone density, using DEXA method, with a special reflection on age subgroups. Material and methods. Clinical research was prospective and it was implemented at the University Clinical Center of Banja Luka, at the Clinic for Endocrinology, Diabetes and Metabolic Diseases and at the Urology Clinic. Material in this research consisted of patients divided in two groups, a working and a control group. One hundred and twenty (120) patients were included in both these groups, divided in three age subgroups: 20-40, 40-60 and over 60. The working group consisted of the patients with calcium urolithiasis and the control group consisted of patients without calcium urolithiasis. Establishing of mineral bone density at L2-L4 of lumbal spine vertebrae and hip was done for the patients in both these groups, using DEXA method. Results. Analysis of mineral bone density using DEXA method in patients in age groups of working and control groups, as well as in the total sample of working and control groups, have shown that the patients of the working group, over 60, had a decreased mineral bone density (30% of osteopenia and 15% osteoporosis) significantly more expressed when compared to the other two age groups (12.5% in the subgroup 20-40 and 17.5% in the subgroup 40-60), which presents a statistically significant difference (p<0.05). In the control group, when taking into account age groups, osteopenia and osteoporosis were marked in 37.5% and 2.5% in the group of patients over 60, whereas in the youngest population, 5% of osteopenia was found, which presents a statistically significant difference (p<0.05). When observing the total sample of working and control group, there was a statistically significant difference in the working and control group (p<0.01); incidence of osteoporosis in the working group amounted to 7.5% and in the control group it was 0.8%. Conclusion. Urolithiasis and osteoporosis are two multifactorial diseases which are evidently reciprocal. This is why we suggest that educating the population about the risk factors for occurrence of these diseases as well as preventive measures that may contribute to their decrease should begin as early as possible. PMID:25568567

Phantom-less bone mineral density (BMD) measurement using dual energy computed tomography-based 3-material decomposition

NASA Astrophysics Data System (ADS)

Hofmann, Philipp; Sedlmair, Martin; Krauss, Bernhard; Wichmann, Julian L.; Bauer, Ralf W.; Flohr, Thomas G.; Mahnken, Andreas H.

2016-03-01

Osteoporosis is a degenerative bone disease usually diagnosed at the manifestation of fragility fractures, which severely endanger the health of especially the elderly. To ensure timely therapeutic countermeasures, noninvasive and widely applicable diagnostic methods are required. Currently the primary quantifiable indicator for bone stability, bone mineral density (BMD), is obtained either by DEXA (Dual-energy X-ray absorptiometry) or qCT (quantitative CT). Both have respective advantages and disadvantages, with DEXA being considered as gold standard. For timely diagnosis of osteoporosis, another CT-based method is presented. A Dual Energy CT reconstruction workflow is being developed to evaluate BMD by evaluating lumbar spine (L1-L4) DE-CT images. The workflow is ROI-based and automated for practical use. A dual energy 3-material decomposition algorithm is used to differentiate bone from soft tissue and fat attenuation. The algorithm uses material attenuation coefficients on different beam energy levels. The bone fraction of the three different tissues is used to calculate the amount of hydroxylapatite in the trabecular bone of the corpus vertebrae inside a predefined ROI. Calibrations have been performed to obtain volumetric bone mineral density (vBMD) without having to add a calibration phantom or to use special scan protocols or hardware. Accuracy and precision are dependent on image noise and comparable to qCT images. Clinical indications are in accordance with the DEXA gold standard. The decomposition-based workflow shows bone degradation effects normally not visible on standard CT images which would induce errors in normal qCT results.

The relationship between bone mineral density and mammographic density in Korean women: the Healthy Twin study.

PubMed

Sung, Joohon; Song, Yun-Mi; Stone, Jennifer; Lee, Kayoung

2011-09-01

Mammographic density is one of the strong risk factors for breast cancer. A potential mechanism for this association is that cumulative exposure to mammographic density may reflect cumulative exposure to hormones that stimulate cell division in breast stroma and epithelium, which may have corresponding effects on breast cancer development. Bone mineral density (BMD), a marker of lifetime estrogen exposure, has been found to be associated with breast cancer. We examined the association between BMD and mammographic density in a Korean population. Study subjects were 730 Korean women selected from the Healthy Twin study. BMD (g/cm(2)) was measured with dual-energy X-ray absorptiometry. Mammographic density was measured from digital mammograms using a computer-assisted thresholding method. Linear mixed model considering familial correlations and a wide range of covariates was used for analyses. Quantitative genetic analysis was completed using SOLAR. In premenopausal women, positive associations existed between absolute dense area and BMD at ribs, pelvis, and legs, and between percent dense area and BMD at pelvis and legs. However, in postmenopausal women, there was no association between BMD at any site and mammographic density measures. An evaluation of additive genetic cross-trait correlation showed that absolute dense area had a weak-positive additive genetic cross-trait correlation with BMD at ribs and spines after full adjustment of covariates. This finding suggests that the association between mammographic density and breast cancer could, at least in part, be attributable to an estrogen-related hormonal mechanism.

Evaluation of factors related to bone disease in Polish children and adolescents with cystic fibrosis.

PubMed

Sands, Dorota; Mielus, Monika; Umławska, Wioleta; Lipowicz, Anna; Oralewska, Beata; Walkowiak, Jarosław

2015-09-01

The aim of the study was to evaluate factors related to bone formation and resorption in Polish children and adolescents with cystic fibrosis and to examine the effect of nutritional status, biochemical parameters and clinical status on bone mineral density. The study group consisted of 100 children and adolescents with cystic fibrosis with a mean age 13.4 years old. Anthropometric measurements, included body height, body mass and body mass index (BMI); bone mineral densitometry and biochemical testing were performed. Bone mineral density was measured using a dual-energy X-ray absorption densitometer. Biochemical tests included serum calcium, phosphorus, parathyroid hormone and vitamin D concentrations, as well as 24-h urine calcium and phosphorus excretion. Pulmonary function was evaluated using FEV1%, and clinical status was estimated using the Shwachman-Kulczycki score. Standardized body height, body mass and BMI were significantly lower than in the reference population. Mean serum vitamin D concentration was decreased. Pulmonary disease was generally mild, with a mean FEV1% of 81%. Multivariate linear regression revealed that the only factors that had a significant effect on bone marrow density were BMI and FEV1%. There were no significant correlations between bone mineral density and the results of any of the biochemical tests performed. Nutritional status and bone mineral density were significantly decreased in children and adolescents with cystic fibrosis. In spite of abnormalities in biochemical testing, the factors that were found to have the strongest effect on bone mineral density were standardized BMI and clinical status. Copyright © 2015. Published by Elsevier Urban & Partner Sp. z o.o.

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

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

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

Dietary Habits Prone to Lifestyle-Related Disease

ERIC Educational Resources Information Center

Nagai, M.; Uyama, O.; Kaji, H.

2013-01-01

Objective: To evaluate relations among dietary habits, bone mineral density (BMD), visceral fat area (VFA), and arterial stiffness and recommend better dietary habits. Methods: One hundred and six men and 381 women (aged 18-84) received a health checkup and answered questionnaires, with subsequent measurements of BMD (speed of sound), VFA…

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.

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

Application of the superfine fraction analysis method in ore gold geochemical prospecting in the Shamanikha-Stolbovsky Area (Magadan Region)

NASA Astrophysics Data System (ADS)

Makarova, Yuliya; Sokolov, Sergey; Glukhov, Anton

2014-05-01

The Shamanikha-Stolbovsky gold cluster is located in the North-East of Russia, in the basin of the Kolyma River. In 1933, gold placers were discovered there, but the search for significant gold targets for more than 50 years did not give positive results. In 2009-2011, geochemical and geophysical studies, mining and drilling were conducted within this cluster. Geochemical exploration was carried out in a modification based on superimposed secondary sorption-salt haloes (sampling density of 250x250 m, 250x50 m, 250x20 m) using the superfine fraction analysis method (SFAM) because of complicated landscape conditions (thick Quaternary sediments, widespread permafrost). The method consists in the extraction of superfine fraction (<10 microns) from unconsolidated sediment samples followed by transfer to a solution of sorption-salt forms of elements and analysis using quantitative methods. The method worked well in areal geochemical studies of various scales in the Karelian-Kola region and in the Far East. Main results of the work in the Shamanikha-Stolbovsky area: 1. Geochemical exploration using the hyperfine fractions analysis method with sampling density of 250x250 m allowed the identification of zonal anomalous geochemical fields (AGCF) classified as an ore deposit promising for the discovery of gold mineralization (Nadezhda, Timsha, and Temny prospects). These AGCF are characterized by following three-zonal structure (from the center to the periphery): nucleus zone - area of centripetal elements concentration (Au, Ag, Sb, As, Cu, Hg, Bi, Pb, Mo); exchange zone - area of centrifugal elements concentration (Mn, Zn, V, Ti, Co, Cr, Ni); flank concentration zone - area of elevated contents of centripetal elements with subbackground centrifugal elements. 2. Detailed AGCF studies with sampling density of 250x50 m (250x20 m) in the Nadezhda, Timsha, and Temny prospects made it possible to refine the composition and structure of anomalous geochemical fields, identify potential gold zones, and determine their formation affinity. Nadezhda Site. Contrast Au, Ag, Pb, Bi, Sb, As dispersion halos that form a linear anomalous geochemical field of ore body rank are identified. Predicted mineralization was related to the gold-sulfosalt mineral association according to the secondary dispersion halos chemical composition. Timsha Site. Contrast secondary Au, Ag, Sb, As, Hg, Pb, Bi dispersion halos are identified. These halos have rhythmically-banded structure, which can be caused by stringer morphological type of mineralization. Bands with anomalously high contents of elements have been interpreted by the authors as probable auriferous bodies. Four such bodies of 700 to 1500 m long were identified. Mineralization of the gold-sulfide formation similar to the "Carlin" type is predicted according to the secondary dispersion halos chemical composition as well as geological features. Temny Site. Contrast secondary Au, Ag, W, Sb dispersion halos are identified. A series of geochemical associations was identified based on factor analysis results. Au-Bi-W-Hg, and Pb-Sb-Ag-Zn associations, apparently related to the mineralization are of the greatest interest. Geochemical fields of these associations are closely spaced and overlapped in plan that may be caused by axial zoning of the subvertically dipping auriferous body. Three linear geochemical zones corresponding to potentially auriferous zones with pyrite type mineralization of the gold-quartz formation are identified within the anomalous geochemical field core zone. 3. In all these prospects, mining and drilling penetrated gold ore bodies within the identified potentially gold zones. The Nadezhda target now has the status of gold deposit.

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.

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.

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

Bonneville, Alain H.; Kouzes, Richard T.

Imaging subsurface geological formations, oil and gas reservoirs, mineral deposits, cavities or magma chambers under active volcanoes has been for many years a major quest of geophysicists and geologists. Since these objects cannot be observed directly, different indirect geophysical methods have been developed. They are all based on variations of certain physical properties of the subsurface that can be detected from the ground surface or from boreholes. Electrical resistivity, seismic wave’s velocities and density are certainly the most used properties. If we look at density, indirect estimates of density distributions are performed currently by seismic reflection methods - since themore » velocity of seismic waves depend also on density - but they are expensive and discontinuous in time. Direct estimates of density are performed using gravimetric data looking at variations of the gravity field induced by the density variations at depth but this is not sufficiently accurate. A new imaging technique using cosmic-ray muon detectors has emerged during the last decade and muon tomography - or muography - promises to provide, for the first time, a complete and precise image of the density distribution in the subsurface. Further, this novel approach has the potential to become a direct, real-time, and low-cost method for monitoring fluid displacement in subsurface reservoirs.« less

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.

Singularity analysis: theory and further developments

NASA Astrophysics Data System (ADS)

Cheng, Qiuming

2015-04-01

Since the concept of singularity and local singularity analysis method (LSA) were originally proposed by the author for characterizing the nonlinear property of hydrothermal mineralization processes, the local singularity analysis technique has been successfully applied for identification of geochemical and geophysical anomalies related to various types of mineral deposits. It has also been shown that the singularity is the generic property of singular geo-processes which result in anomalous amounts of energy release or material accumulation within a narrow spatial-temporal interval. In the current paper we introduce several new developments about singularity analysis. First is a new concept of 'fractal density' which describes the singularity of complex phenomena of fractal nature. While the ordinary density possesses a unit of ratio of mass and volume (e.g. g/cm3, kg/m3) or ratio of energy over volume or time (e.g. J/cm3, w/L3, w/s), the fractal density has a unit of ratio of mass over fractal set or energy over fractal set (e.g. g/cmα, kg/mα, J/ mα, w/Lα, where α can be a non-integer). For the matter with fractal density (a non-integer α), the ordinary density of the phenomena (mass or energy) no longer exists and depicts singularity. We demonstrate that most of extreme geo-processes occurred in the earth crust originated from cascade earth dynamics (mental convection, plate tectonics, orogeny and weathering etc) may cause fractal density of mass accumulation or energy release. The examples to be used to demonstrate the concepts of fractal density and singularity are earthquakes, floods, volcanos, hurricanes, heat flow over oceanic ridge, hydrothermal mineralization in orogenic belt, and anomalies in regolith over mine caused by ore and toxic elements vertical migration. Other developments of singularity theory and methodologies including singular Kriging and singularity weights of evidence model for information integration will also be introduced.

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.

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.

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

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

Autologous implantation of BMP2-expressing dermal fibroblasts to improve bone mineral density and architecture in rabbit long bones.

PubMed

Ishihara, Akikazu; Weisbrode, Steve E; Bertone, Alicia L

2015-10-01

Cell-mediated gene therapy may treat bone fragility disorders. Dermal fibroblasts (DFb) may be an alternative cell source to stem cells for orthopedic gene therapy because of their rapid cell yield and excellent plasticity with bone morphogenetic protein-2 (BMP2) gene transduction. Autologous DFb or BMP2-expressing autologous DFb were administered in twelve rabbits by two delivery routes; a transcortical intra-medullar infusion into tibiae and delayed intra-osseous injection into femoral drill defects. Both delivery methods of DFb-BMP2 resulted in a successful cell engraftment, increased bone volume, bone mineral density, improved trabecular bone microarchitecture, greater bone defect filling, external callus formation, and trabecular surface area, compared to non-transduced DFb or no cells. Cell engraftment within trabecular bone and bone marrow tissue was most efficiently achieved by intra-osseous injection of DFb-BMP2. Our results suggested that BMP2-expressing autologous DFb have enhanced efficiency of engraftment in target bones resulting in a measurable biologic response by the bone of improved bone mineral density and bone microarchitecture. These results support that autologous implantation of DFb-BMP2 warrants further study on animal models of bone fragility disorders, such as osteogenesis imperfecta and osteoporosis to potentially enhance bone quality, particularly along with other gene modification of these diseases. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

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

Disrupted Bone Metabolism in Long-Term Bedridden Patients

PubMed Central

Endo, Naoto; Uchiyama, Seiji; Takahashi, Yoshinori; Kawashima, Hiroyuki; Watanabe, Kei

2016-01-01

Background Bedridden patients are at risk of osteoporosis and fractures, although the long-term bone metabolic processes in these patients are poorly understood. Therefore, we aimed to determine how long-term bed confinement affects bone metabolism. Methods This study included 36 patients who had been bedridden from birth due to severe immobility. Bone mineral density and bone metabolism markers were compared to the bedridden period in all study patients. Changes in the bone metabolism markers during a follow-up of 12 years were studied in 17 patients aged <30 years at baseline. Results The bone mineral density was reduced (0.58±0.19 g/cm3), and the osteocalcin (13.9±12.4 ng/mL) and urine N-terminal telopeptide (NTX) levels (146.9±134.0 mM BCE/mM creatinine) were greater than the cutoff value for predicting fracture. Among the bone metabolism markers studied, osteocalcin and NTX were negatively associated with the bedridden period. During the follow-up, osteocalcin and parathyroid hormone were decreased, and the 25(OH) vitamin D was increased. NTX at baseline was negatively associated with bone mineral density after 12 years. Conclusions Unique bone metabolic abnormalities were found in patients who had been bedridden for long periods, and these metabolic abnormalities were altered by further bed confinement. Appropriate treatment based on the unique bone metabolic changes may be important in long-term bedridden patients. PMID:27275738

Risk Factors for Osteoporosis Among Middle-Aged Women

ERIC Educational Resources Information Center

Turner, Lori W.; Wallace, Lorraine Silver; Perry, Blake Allen; Bleeker, Jeanne

2004-01-01

Objective: To investigate the risk factors for osteoporosis among a sample of middle-aged women. Methods: Adipose tissue and bone mineral density levels at the left femur, lumbar spine, and total body were assessed using dual-energy x-ray absorptiometry (DXA). Subjects (n=342) were surveyed regarding a variety of osteoporosis-related risk factors.…

Bone mineral density changes after ovariectomy in rats as an osteopenic model : stepwise description of double dorso-lateral approach.

PubMed

Park, Sung Bae; Lee, Yoon Jin; Chung, Chun Kee

2010-10-01

This study describes a method for inducing osteopenia using bilateral ovariectomy (OVX), which causes significant changes in bone mineral density (BMD) in rats. Twenty-five 10-week-old female Sprague Dawley rats were used. Five rats were euthanized after two weeks, and BMD was measured in their femora. The other 20 rats were assigned to one of two groups : a sham group (n = 10), which underwent a sham operation, and an OVX group (n = 10), which underwent bilateral OVX at 12 weeks of age. After six weeks, five rats from each group were euthanized, and BMD was measured in their femora. The same procedures were performed in the remaining rats form each group eight weeks later. The femur BMD was significantly lower in the six-week OVX group than in the six-week sham group, and in the eight-week OVX group than in the eight-week sham group. Bilateral OVX is a safe method for creating an osteopenic rat model. The significant decrease in BMD appears six weeks after bilateral OVX.

Fission track astrology of three Apollo 14 gas-rich breccias

NASA Technical Reports Server (NTRS)

Graf, H.; Shirck, J.; Sun, S.; Walker, R.

1973-01-01

The three Apollo 14 breccias 14301, 14313, and 14318 all show fission xenon due to the decay of Pu-244. To investigate possible in situ production of the fission gas, an analysis was made of the U-distribution in these three breccias. The major amount of the U lies in glass clasts and in matrix material and no more than 25% occurs in distinct high-U minerals. The U-distribution of each breccia is discussed in detail. Whitlockite grains in breccias 14301 and 14318 found with the U-mapping were etched and analyzed for fission tracks. The excess track densities are much smaller than indicated by the Xe-excess. Because of a preirradiation history documented by very high track densities in feldspar grains, however, it is impossible to attribute the excess tracks to the decay of Pu-244. A modified track method has been developed for measuring average U-concentrations in samples containing a heterogeneous distribution of U in the form of small high-U minerals. The method is briefly discussed, and results for the rocks 14301, 14313, 14318, 68815, 15595, and the soil 64421 are given.

Effect of methylprednisolone on bone mineral density in rats with ovariectomy-induced bone loss and suppressed endogenous adrenaline levels by metyrosine

PubMed Central

Yilmaz, Mehmet; Isaoglu, Unal; Uslu, Turan; Yildirim, Kadir; Seven, Bedri; Akcay, Fatih; Hacimuftuoglu, Ahmet

2013-01-01

Objectives: In this study, effect of methylprednisolone on bone mineral density (BMD) was investigated in rats with overiectomy induced bone lose and suppressed endogenous adrenalin levels, and compared to alendronate. Materials and Methods: Severity of bone loss in the examined material (femur bones) was evaluated by BMD measurement. Results: The group with the highest BMD value was metyrosinemetyrosine + methylprednisolone combination (0.151 g/cm2), while that with the lowest BMD was methylprednisolone (0.123 g/cm2). Alendronate was effective only when used alone in ovariectomized rats (0.144 g/cm2), but not when used in combination with methylprednisolone (0.124 g/cm2). In the ovariectomized rat group which received only metyrosine, BMD value was statistically indifferent from ovariectomized control group. Conclusions: Methylprednisolone protected bone loss in rats with suppressed adrenaline levels because of metyrosinemetyrosine. PMID:24014908

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.

Scattered image artifacts from cone beam computed tomography and its clinical potential in bone mineral density estimation.

PubMed

Ko, Hoon; Jeong, Kwanmoon; Lee, Chang-Hoon; Jun, Hong Young; Jeong, Changwon; Lee, Myeung Su; Nam, Yunyoung; Yoon, Kwon-Ha; Lee, Jinseok

2016-01-01

Image artifacts affect the quality of medical images and may obscure anatomic structure and pathology. Numerous methods for suppression and correction of scattered image artifacts have been suggested in the past three decades. In this paper, we assessed the feasibility of use of information on scattered artifacts for estimation of bone mineral density (BMD) without dual-energy X-ray absorptiometry (DXA) or quantitative computed tomographic imaging (QCT). To investigate the relationship between scattered image artifacts and BMD, we first used a forearm phantom and cone-beam computed tomography. In the phantom, we considered two regions of interest-bone-equivalent solid material containing 50 mg HA per cm(-3) and water-to represent low- and high-density trabecular bone, respectively. We compared the scattered image artifacts in the high-density material with those in the low-density material. The technique was then applied to osteoporosis patients and healthy subjects to assess its feasibility for BMD estimation. The high-density material produced a greater number of scattered image artifacts than the low-density material. Moreover, the radius and ulna of healthy subjects produced a greater number of scattered image artifacts than those from osteoporosis patients. Although other parameters, such as bone thickness and X-ray incidence, should be considered, our technique facilitated BMD estimation directly without DXA or QCT. We believe that BMD estimation based on assessment of scattered image artifacts may benefit the prevention, early treatment and management of osteoporosis.

Osteoporosis screening is unjustifiably low in older African-American women.

PubMed Central

Wilkins, Consuelo H.; Goldfeder, Jason S.

2004-01-01

BACKGROUND: More than one million Americans suffer osteoporotic fractures yearly, resulting in a marked increase in morbidity and mortality. Despite a decrease in bone mineral density with increasing age in all ethnic groups and both genders, preventative and therapeutics efforts in osteoporosis have been focused on caucasian and Asian women. This study assesses the osteoporosis screening practices and the frequency of low bone density in a primarily African-American population of older women. METHODS: Medical records of 252 women at risk for osteoporosis were reviewed for the diagnosis of osteoporosis, prior osteoporosis screening, prior breast cancer screening, and the use of calcium, vitamin D or estrogen. Subsequently, 128 women were assessed for risk factors for osteoporosis, and their bone mineral density was measured using a peripheral bone densitometer. RESULTS: Osteoporosis screening had been performed in 11.5% of the subjects. Of the women evaluated by peripheral bone densitometry, 44.5% of all women, 40.4% of African-American women, and 53.3% of caucasian women had abnormally low bone density measurements. The frequency of abnormal bone density increased with both increasing age and decreasing body mass index. CONCLUSIONS: Although few women in this population were previously screened for osteoporosis, low bone density occurred in African-American women at substantial rates. Increasing age and low body mass are important risk factors for low bone density in African-American women. Ethnicity should not be used as an exclusion criterion for screening for osteoporosis. PMID:15101666

Research on the influence of bilateral oophorectomy on the BMD, body components and sex hormone of women during the perimenopause.

PubMed

Wang, HaiLi; Wang, Chuchu; Sun, Lei; Zhou, Shiyuan; Wang, Fengyu

2017-07-01

To investigate the effect of bilateral oophorectomy on bone mineral density, body composition and sex hormone of peri-menopause women. 33 cases of peri-menopause women patients performed bilateral oophorectomy were chosen from xxx gynaecology and obstetrics department of xxx hospital from January 1st,2014 to Dec31th, 2014. And the 33 cases were taken as ovariectomy group. 35 women who were the naturally postmenopausal after menopause collected in clinic and in the same period with the patients of ovariectomy group were taken in control group. American GE-Lunar-Prodigy dual energy X-ray absorptiometry and chemiluminescence method were employed to detect the bone mineral density, fat content, muscle content and sex hormone of the patients in both groups at the 6th and 12th month after menostasis. There was no statistical significance on the comparative difference of bone mineral density, fat content and muscle content at the 6th and 12th month after menostasis between both groups, P>0.05. At the 6th month after menostasis, the estradiol (E2) level in ovariectomy group was significantly lower than that of control group [(14.79±22.17)U/L vs (32.74±31.02U/L)], P<0.05; at the 12th month after menostasis, it had the statistical significance for the comparative difference between the level of E2 and and follicle-stimulating hormone (FSH) in ovariectomy group and that in control group, E2: (8.09±4.38)U/L vs (25.92±3.53)U/L; FSH: (64.88±18.39)U/L vs (40.69±31.63)U/L], P<0.05. the change of E2 and FSH were the main symptom of peri-menopausal women within 12 months after bilateral oophorectomy, the decrease of E2 level had no effect on bone mineral density, fat content and muscle content.

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

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.

Physical Activity and Bone Density in Women

NASA Technical Reports Server (NTRS)

Bowley, Susan M.; Whalen, R. T.

2000-01-01

A mathematical model of bone density regulation as a function of the daily tissue "effective" stress has been derived. Using the model, the influence of daily activity in the form of a daily loading history has been related to bone density of the calcaneus. The theory incorporates a stress exponent m to account for differences in the importance of magnitude and number of load cycles experienced during daily activity. We have derived a parameter from the model, the "Bone Density Index" (BDI). We have developed a method of collecting daily habitual loading histories using an insole force sensor interfaced to a portable digital data logger carried in a fanny pack. Our goal for this study was to determine a stress exponent, m, relating GRFz history to Calcaneal Bone Mineral Density (CBMD).

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

Ranjanomennahary, P.; Ghalila, S. Sevestre; Malouche, D

Purpose: Hip fracture is a serious health problem and textural methods are being developed to assess bone quality. The authors aimed to perform textural analysis at femur on high-resolution digital radiographs compared to three-dimensional (3D) microarchitecture comparatively to bone mineral density. Methods: Sixteen cadaveric femurs were imaged with an x-ray device using a C-MOS sensor. One 17 mm square region of interest (ROI) was selected in the femoral head (FH) and one in the great trochanter (GT). Two-dimensional (2D) textural features from the co-occurrence matrices were extracted. Site-matched measurements of bone mineral density were performed. Inside each ROI, a 16more » mm diameter core was extracted. Apparent density (D{sub app}) and bone volume proportion (BV/TV{sub Arch}) were measured from a defatted bone core using Archimedes' principle. Microcomputed tomography images of the entire length of the core were obtained (Skyscan 1072) at 19.8 {mu}m of resolution and usual 3D morphometric parameters were computed on the binary volume after calibration from BV/TV{sub Arch}. Then, bone surface/bone volume, trabecular thickness, trabecular separation, and trabecular number were obtained by direct methods without model assumption and the structure model index was calculated. Results: In univariate analysis, the correlation coefficients between 2D textural features and 3D morphological parameters reached 0.83 at the FH and 0.79 at the GT. In multivariate canonical correlation analysis, coefficients of the first component reached 0.95 at the FH and 0.88 at the GT. Conclusions: Digital radiographs, widely available and economically viable, are an alternative method for evaluating bone microarchitectural structure.« less

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.

Mineral oil certified reference materials for the determination of polychlorinated biphenyls from the National Metrology Institute of Japan (NMIJ)

PubMed Central

Aoyagi, Yoshie; Matsuo, Mayumi; Ishikawa, Keiichiro; Hanari, Nobuyasu; Otsuka, Satoko; Tsuda, Yoko; Yarita, Takashi

2008-01-01

Four mineral oil certified reference materials (CRMs), NMIJ CRM 7902-a, CRM 7903-a, CRM 7904-a, and CRM 7905-a, have been issued by the National Metrology Institute of Japan, which is part of the National Institute of Advanced Industrial Science and Technology (NMIJ/AIST), for the determination of polychlorinated biphenyls (PCBs). The raw materials for the CRMs were an insulation oil (CRM 7902-a and CRM 7903-a) and a fuel oil (CRM7904-a and CRM 7905-a). A solution of PCB3, PCB8, and technical PCB products, comprising four types of Kaneclor, was added to the oil matrices. The total PCB concentrations in the PCB-fortified oils (CRM 7902-a and CRM 7904-a) are approximately 6 mg kg−1. In addition, the mineral oils which were not fortified with PCBs were also distributed as CRMs (CRM 7903-a and CRM 7905-a). Characterization of these CRMs was conducted by the NMIJ/AIST, where the mineral oils and the PCB solution were analyzed using multiple analytical methods such as dimethylsulfoxide extraction, normal-phase liquid chromatography, gel permeation chromatography, reversed-phase liquid chromatography, and chromatography using sulfoxide-bonded silica; and/or various capillary columns for gas chromatography, and two ionization modes for mass spectrometry. The target compounds in the mineral oils and those in the PCB solution were determined by one of the primary methods of measurement, isotope dilution–mass spectrometry (ID-MS). Certified values have been provided for 11 PCB congeners (PCB3, 8, 28, 52, 101, 118, 138, 153, 180, 194, and 206) in the CRMs. These CRMs have information values for PCB homologue concentrations determined by using a Japanese official method for determination of PCBs in wastes and densities determined with an oscillational density meter. Because oil samples having arbitrary PCB concentrations between respective property values of the PCB-fortified and nonfortified CRMs can be prepared by gravimetric mixing of the CRM pairs, these CRMs can be used for validation of PCB analyses using various instruments which have different sensitivities. Figure Preparation and certification processes of the mineral oil CRMs (example shown is polychlorinated biphenyls in insulation oil, high/low concentrations) Electronic supplementary material The online version of this article (doi:10.1007/s00216-008-2010-3) contains supplementary material, which is available to authorized users. PMID:18415091

Evaluation of methylation status of the eNOS promoter at birth in relation to childhood bone mineral content

PubMed Central

Harvey, Nicholas C.; Lillycrop, Karen A.; Garratt, Emma; Sheppard, Allan; McLean, Cameron; Burdge, Graham; Slater-Jefferies, Jo; Rodford, Joanne; Crozier, Sarah; Inskip, Hazel; Emerald, Bright Starling; Gale, Catharine R; Hanson, Mark; Gluckman, Peter; Godfrey, Keith; Cooper, Cyrus

2013-01-01

Aim Our previous work has shown associations between childhood adiposity and perinatal methylation status of several genes in umbilical cord tissue, including endothelial nitric oxide synthase (eNOS). There is increasing evidence that eNOS is important in bone metabolism; we therefore related the methylation status of the eNOS gene promoter in stored umbilical cord to childhood bone size and density in a group of 9-year old children. Methods We used Sequenom MassARRAY to assess the methylation status of 2 CpGs in the eNOS promoter, identified from our previous study, in stored umbilical cords of 66 children who formed part of a Southampton birth cohort and who had measurements of bone size and density at age 9 years (Lunar DPXL DXA instrument). Results Percentage methylation varied greatly between subjects. For one of the two CpGs, eNOS chr7:150315553+, after taking account of age and sex there was a strong positive association between methylation status and the child’s whole body bone area (r=0.28,p=0.02), bone mineral content (r=0.34,p=0.005) and areal bone mineral density (r=0.34,p=0.005) at age 9 years. These associations were independent of previously documented maternal determinants of offspring bone mass. Conclusions Our findings suggest an association between methylation status at birth of a specific CpG within the eNOS promoter and bone mineral content in childhood. This supports a role for eNOS in bone growth and metabolism and implies that its contribution may at least in part occur during early skeletal development. PMID:22159788

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

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.

Bone mineral density, serum albumin and serum magnesium.

PubMed

Saito, Noboru; Tabata, Naoto; Saito, Saburou; Andou, Yoshihisa; Onaga, Yukiko; Iwamitsu, Akihiro; Sakamoto, Morihide; Hori, Tuyoshi; Sayama, Harumi; Kawakita, Toshiko

2004-12-01

This study explores clinical and laboratory abnormalities that contribute to the prevalence of bone fractures in frail and control elderly patients, to ascertain factors that relate to bone strength and fragility. Patients were selected as free from renal failure and not taking supplements or medications that affect their magnesium status, and categorized according to their underlying diseases, sex and age, and evaluated by tests of bone strength. Findings, differentiating elderly patients on the basis of their magnesium, calcium, serum albumin, body mass, bone mineral density and their fracture occurrence were tabulated. Evidence is presented of low magnesium and albumin serum levels, especially in women with low bone density, as well as of low calcium and trace minerals.

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.

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.

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. ...

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

Distribution of trace elements in selected pulverized coals as a function of particle size and density

USGS Publications Warehouse

Senior, C.L.; Zeng, T.; Che, J.; Ames, M.R.; Sarofim, A.F.; Olmez, I.; Huggins, Frank E.; Shah, N.; Huffman, G.P.; Kolker, A.; Mroczkowski, S.; Palmer, C.; Finkelman, R.

2000-01-01

Trace elements in coal have diverse modes of occurrence that will greatly influence their behavior in many coal utilization processes. Mode of occurrence is important in determining the partitioning during coal cleaning by conventional processes, the susceptibility to oxidation upon exposure to air, as well as the changes in physical properties upon heating. In this study, three complementary methods were used to determine the concentrations and chemical states of trace elements in pulverized samples of four US coals: Pittsburgh, Illinois No. 6, Elkhorn and Hazard, and Wyodak coals. Neutron Activation Analysis (NAA) was used to measure the absolute concentration of elements in the parent coals and in the size- and density-fractionated samples. Chemical leaching and X-ray absorption fine structure (XAFS) spectroscopy were used to provide information on the form of occurrence of an element in the parent coals. The composition differences between size-segregated coal samples of different density mainly reflect the large density difference between minerals, especially pyrite, and the organic portion of the coal. The heavy density fractions are therefore enriched in pyrite and the elements associated with pyrite, as also shown by the leaching and XAFS methods. Nearly all the As is associated with pyrite in the three bituminous coals studied. The sub-bituminous coal has a very low content of pyrite and arsenic; in this coal arsenic appears to be primarily organically associated. Selenium is mainly associated with pyrite in the bituminous coal samples. In two bituminous coal samples, zinc is mostly in the form of ZnS or associated with pyrite, whereas it appears to be associated with other minerals in the other two coals. Zinc is also the only trace element studied that is significantly more concentrated in the smaller (45 to 63 ??m) coal particles.

The influence of vegan diet on bone mineral density and biochemical bone turnover markers.

PubMed

Ambroszkiewicz, Jadwiga; Klemarczyk, Witold; Gajewska, Joanna; Chełchowska, Magdalena; Franek, Edward; Laskowska-Klita, Teresa

2010-01-01

Vegetarian diets can be healthy when they are well balanced and if a variety of foods is consumed. However, elimination of animal products from the diet (vegan diets) decreases the intake of some essential nutrients and may influence the bone metabolism. This is especially important in childhood and adolescence, when growth and bone turnover are most intensive. The aim of the study was to assess the effect of vegan diet on bone density (BMD) density and serum concentrations of bone metabolism markers. We examined a family on vegan diet which consisted of parents and two children. Dietary constituents were analysed using a nutritional program. Total and regional BMD were measured by dual-energy X-ray absorptiometry. Concentrations of calcium and phosphate in serum obtained from fasting patients were determined by colorimetric methods, 25-hydroxyvitamin D by the chemiluminescence method and bone turnover markers by specific enzyme immunoassays. In studied vegans, the dietary intake of phosphate was adequate while calcium and vitamin D were below the recommended range. Concentrations of calcium, phosphate and bone turnover markers in the serum of all subjects were within the physiological range, but 25-hydroxyvitamin D level was low. Age-matched Z-score total BMD was between -0.6 and 0.3 in adults, however in children it was lower (-0.9 and -1.0). Z-score BMD lumbar spine (L2-L4) was between -0.9 to -1.9 in parents and -1.5 to -1.7 in children. Our results suggest that an inadequate dietary intake of calcium and vitamin D may impair the bone turnover rate and cause a decrease in bone mineral density in vegans. The parameters of bone density and bone metabolism should be monitored in vegans, especially children, in order to prevent bone abnormalities.

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.

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.

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.

Application of gamma ray spectrometric measurements and VLF-EM data for tracing vein type uranium mineralization

NASA Astrophysics Data System (ADS)

Gaafar, Ibrahim

2015-12-01

This study is an attempt to use the gamma ray spectrometric measurements and VLF-EM data to identify the subsurface structure and map uranium mineralization along El Sela shear zone, South Eastern Desert of Egypt. Many injections more or less mineralized with uranium and associated with alteration processes were recorded in El Sela shear zone. As results from previous works, the emplacement of these injections is structurally controlled and well defined by large shear zones striking in an ENE-WSW direction and crosscut by NW-SE to NNW-SSE fault sets. VLF method has been applied to map the structure and the presence of radioactive minerals that have been delineated by the detection of high uranium mineralization. The electromagnetic survey was carried out to detect the presence of shallow and deep conductive zones that cross the granites along ENE-WSW fracturing directions and to map its spatial distribution. The survey comprised seventy N-S spectrometry and VLF-EM profiles with 20 m separation. The resulted data were displayed as composite maps for K, eU and eTh as well as VLF-Fraser map. Twelve profiles with 100 m separation were selected for detailed description. The VLF-EM data were interpreted qualitatively as well as quantitatively using the Fraser and the Karous-Hjelt filters. Fraser filtered data and relative current density pseudo-sections indicate the presence of shallow and deep conductive zones that cross the granites along ENE-WSW shearing directions. High uranium concentrations found just above the higher apparent current-density zones that coincide with El-Sela shear zone indicate a positive relation between conductivity and uranium minerals occurrence. This enables to infer that the anomalies detected by VLF-EM data are due to the highly conductive shear zone enriched with uranium mineralization extending for more than 80 m.

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.

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.

In vivo measurement of the trabecular bone mineral density by coherent and Compton. gamma. -ray scattering

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

Karellas, A.

1984-01-01

A photon scattering method for measuring the mineral density of trabecular bone (BMD) is described. By computing the ratio of the coherent to Compton scattered photons, the BMD can be measured accurately and without any significant interference by the surrounding tissue. This study shows theoretically and experimentally that an increase in the scatter angle, when using 60 keV photons from Am-241, results in a stronger power dependence on Z. This implies that by increasing the scatter angle, smaller changes in BMD can be detected, thus improving the sensitivity of the measurement. The dependence of the sensitivity on the energy ofmore » the incident photons was also investigated. A collimated beam of photons from 1200 mCi of Am-241 (60 keV) was used and the scattered photons were detected at a scatter angle of 71/sup 0/. The system was calibrated by using a new standard which contains bone mineral mixed homogeneously with a marrow simulating substance. This method was applied for the measurement of the calcaneal BMD in 21 normal volunteers and seven paraplegic patients. The BMD values for the normal group ranged from 170-300 mg/cm/sup 3/. The BMD for the paraplegics with injuries older than one year ranged from 90-150 mg/cm/sup 3/. This measurement has potential application in the diagnosis of early osteopenia and in monitoring the effect of various treatment regimens.« less

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.

Numerical analysis of wet separation of particles by density differences

NASA Astrophysics Data System (ADS)

Markauskas, D.; Kruggel-Emden, H.

2017-07-01

Wet particle separation is widely used in mineral processing and plastic recycling to separate mixtures of particulate materials into further usable fractions due to density differences. This work presents efforts aiming to numerically analyze the wet separation of particles with different densities. In the current study the discrete element method (DEM) is used for the solid phase while the smoothed particle hydrodynamics (SPH) is used for modeling of the liquid phase. The two phases are coupled by the use of a volume averaging technique. In the current study, simulations of spherical particle separation were performed. In these simulations, a set of generated particles with two different densities is dropped into a rectangular container filled with liquid. The results of simulations with two different mixtures of particles demonstrated how separation depends on the densities of particles.

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)

Quantitative data standardization of X-ray based densitometry methods

NASA Astrophysics Data System (ADS)

Sergunova, K. A.; Petraikin, A. V.; Petrjajkin, F. A.; Akhmad, K. S.; Semenov, D. S.; Potrakhov, N. N.

2018-02-01

In the present work is proposed the design of special liquid phantom for assessing the accuracy of quantitative densitometric data. Also are represented the dependencies between the measured bone mineral density values and the given values for different X-ray based densitometry techniques. Shown linear graphs make it possible to introduce correction factors to increase the accuracy of BMD measurement by QCT, DXA and DECT methods, and to use them for standardization and comparison of measurements.

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

Organic carbon characteristics in density fractions of soils with contrasting mineralogies

NASA Astrophysics Data System (ADS)

Yeasmin, Sabina; Singh, Balwant; Johnston, Cliff T.; Sparks, Donald L.

2017-12-01

This study was aimed to evaluate the role of minerals in the preservation of organic carbon (OC) in different soil types. Sequential density fractionation was done to isolate particulate organic matter (POM, <1.8 g cm-3) and mineral associated OM (MOM: 1.8-2.2, 2.2-2.6 and >2.6 g cm-3) from four soils, i.e., a Ferralsol, a Luvisol, a Vertisol and a Solonetz. Organic matter (OM) in the density fractions was characterised using diffuse reflectance Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and mass spectroscopy in the original states (i.e., without any chemical pre-treatment), and after 6% sodium hypochlorite (NaOCl) and 10% hydrofluoric acid (HF) treatments. The NaOCl oxidation resistant fraction was considered as a relatively stable pool of OC and the HF soluble fraction was presumed as the mineral bound OC. Phyllosilicate-dominated soils, i.e., Vertisol, Luvisol and Solonetz, contained a greater proportion of POM than Fe and Al oxide-dominated Ferralsol. Wider C:N ratio and lower δ13C and δ15N in POM suggest the dominance of labile OC in this fraction and this was also supported by a greater proportion of NaOCl oxidised OC in the same fraction that was enriched with aliphatic C. The sequential density fractionation method effectively isolated OM into three distinct groups in the soils: (i) OM associated with Fe and Al oxides (>1.8 g cm-3 in the Ferralsol); (ii) OM associated with phyllosilicates (1.8-2.6 g cm-3) and (iii) OM associated with quartz and feldspar (>2.6 g cm-3) in the other three soils. Greater oxidation resistance, and more dissolution of OC during the HF treatment in the Fe and Al oxides dominated fractions suggest a greater potential of these minerals to protect OC from oxidative degradation as compared to the phyllosilicates, and quartz and feldspar matrices. OM associated with Fe and Al oxides was predominantly aromatic and carboxylate C. Decreased C:N ratio in the NaOCl oxidation resistant OM and HF soluble OM of phyllosilicates, and quartz and feldspars dominant fractions compared to their untreated fractions indicate a preferred retention of N rich organic compounds by these minerals. OM associated with phyllosilicates was enriched with protonated amide N and aromatic C. Quartz and feldspars associated OM comprised of N containing organic compounds and polysaccharides, although we don't expect any role of these minerals in their preservation. Our results imply that the abundance and surface properties of minerals in the soil largely control the dynamics of OC and subsequently protect OC from microbial cycling.

Selected elements in major minerals from bituminous coal as determined by INAA: Implications for removing environmentally sensitive elements from coal

USGS Publications Warehouse

Palmer, C.A.; Lyons, P.C.

1996-01-01

The four most abundant minerals generally found in Euramerican bituminous coals are quartz, kaolinite, illite and pyrite. These four minerals were isolated by density separation and handpicking from bituminous coal samples collected in the Ruhr Basin, Germany and the Appalachian basin, U.S.A. Trace-element concentrations of relatively pure (??? 99+%) separates of major minerals from these coals were determined directly by using instrumental neutron activation analysis (INAA). As expected, quartz contributes little to the trace-element mass balance. Illite generally has higher trace-element concentrations than kaolinite, but, for the concentrates analyzed in this study, Hf, Ta, W, Th and U are in lower concentrations in illite than in kaolinite. Pyrite has higher concentrations of chalcophile elements (e.g., As and Se) and is considerably lower in lithophile elements as compared to kaolinite and illite. Our study provides a direct and sensitive method of determining trace-element relationships with minerals in coal. Mass-balance calculations suggest that the trace-element content of coal can be explained mainly by three major minerals: pyrite, kaolinite and illite. This conclusion indicates that the size and textural relationships of these major coal minerals may be a more important consideration as to whether coal cleaning can effectively remove the most environmentally sensitive trace elements in coal than what trace minerals are present.

Feasibility of Quantitative Ultrasound Measurement of the Heel Bone in People with Intellectual Disabilities

ERIC Educational Resources Information Center

Mergler, S.; Lobker, B.; Evenhuis, H. M.; Penning, C.

2010-01-01

Low bone mineral density (BMD) and fractures are common in people with intellectual disabilities (ID). Reduced mobility in case of motor impairment and the use of anti-epileptic drugs contribute to the development of low BMD. Quantitative ultrasound (QUS) measurement of the heel bone is a non-invasive and radiation-free method for measuring bone…

[MINERAL BONE DENSITY AND BODY COMPOSITION IN PARTICIPANTS IN EXPERIMENT MARS-500].

PubMed

Novikov, V E; Oganov, V S; Kabitskaya, O E; Murashko, L M; Naidina, V P; Chernikhova, E A

2016-01-01

Investigations of the bone system and body composition in Mars-500 test-subjects (prior to and on completion of the experiment) involved dual-energy X-ray absorptiometry (DXA) using the HOLOGIC Delphy densitometer and the protocol performed to examine cosmonauts. Bone density of lumber vertebrae and femoral proximal epiphysis, and body composition were measured. Reliable changes in vertebral density found in 3 test-subjects displayed different trends from +2.6 to -2.4%. At the same time, the experiment decreased significantly mineral density of the femoral proximal epiphysis, including the neck, in all test-subjects. Four test-subjects had cranial mineralization increased by 5-9%, same as in some cosmonauts after space flight. All tests-subjects incurred adipose loss from 2 to 7 kg; one test-subject lost 20 kg, i.e. his adipose mass became three times less. Changes in lean mass (1-3 kg) typically were negative; as for changes in lean mass of extremities, they could be linked with adherence to one or another type of physical activity. Therefore, extended exposure to confinement may affect mineralization of some parts of the skeleton. Unlike real space missions and long-term bedrest studies conducted at the Institute of Biomedical Problems in the past, Mars-500 did not cause clinically significant mineral losses (osteoporosis, osteopenia), probably because of the absence of effects of microgravity.

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.

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.

[Effect of high impact movements on body composition, strength and bone mineral density on women over 60 years].

PubMed

Ramírez-Villada, Jhon F; León-Ariza, Henry H; Argüello-Gutiérrez, Yenny P; Porras-Ramírez, Keyla A

2016-01-01

Osteoporosis is characterised by loss of bone mass and deterioration of bone tissue microarchitecture that leads to fragility related to the risk of fractures. The aim of the study is to analyse the effects of a training program based on explosive movements and impact, assessed in a swimming pool, on body composition, explosive strength and bone mineral density in women over 60 years old. A total of 35 healthy physically active women (60±4.19 years) were divided into a training pool group using multi jumps (JG) and a control group (CG). JG trained for 24 weeks, 3 times a week, an hour and a half per session. Body composition testing, explosive strength, and bone mineral density were assessed before and after the program. There were differences in the explosive force (JG vs CG=P<.05 to .001) and the estimated power (JG vs CG=P<.05 to .002) between JG vs CG, with significant increases in JG. There were no significant differences in the percentage of fat and lean mass, bone mineral density lumbar and femoral between groups, although slightly significant increases in bone mineral density lumbar and femoral could be seen in JG after program implementation (JG pre-test vs JG post- test=P<.05). The training program with impact and explosive movements assessed in a pool induces gains in muscle strength and power with slight adaptations in body mass index in women over 60 years. Copyright © 2015 SEGG. Published by Elsevier Espana. All rights reserved.

Analysis of enamel development using murine model systems: approaches and limitations

PubMed Central

Pugach, Megan K.; Gibson, Carolyn W.

2014-01-01

A primary goal of enamel research is to understand and potentially treat or prevent enamel defects related to amelogenesis imperfecta (AI). Rodents are ideal models to assist our understanding of how enamel is formed because they are easily genetically modified, and their continuously erupting incisors display all stages of enamel development and mineralization. While numerous methods have been developed to generate and analyze genetically modified rodent enamel, it is crucial to understand the limitations and challenges associated with these methods in order to draw appropriate conclusions that can be applied translationally, to AI patient care. We have highlighted methods involved in generating and analyzing rodent enamel and potential approaches to overcoming limitations of these methods: (1) generating transgenic, knockout, and knockin mouse models, and (2) analyzing rodent enamel mineral density and functional properties (structure and mechanics) of mature enamel. There is a need for a standardized workflow to analyze enamel phenotypes in rodent models so that investigators can compare data from different studies. These methods include analyses of gene and protein expression, developing enamel histology, enamel pigment, degree of mineralization, enamel structure, and mechanical properties. Standardization of these methods with regard to stage of enamel development and sample preparation is crucial, and ideally investigators can use correlative and complementary techniques with the understanding that developing mouse enamel is dynamic and complex. PMID:25278900

[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…

Coupled X-ray computed tomography and grey level co-occurrence matrices as a method for quantification of mineralogy and texture in 3D

NASA Astrophysics Data System (ADS)

Jardine, M. A.; Miller, J. A.; Becker, M.

2018-02-01

Texture is one of the most basic descriptors used in the geological sciences. The value derived from textural characterisation extends into engineering applications associated with mining, mineral processing and metal extraction where quantitative textural information is required for models predicting the response of the ore through a particular process. This study extends the well-known 2D grey level co-occurrence matrices methodology into 3D as a method for image analysis of 3D x-ray computed tomography grey scale volumes of drill core. Subsequent interrogation of the information embedded within the grey level occurrence matrices (GLCM) indicates they are sensitive to changes in mineralogy and texture of samples derived from a magmatic nickel sulfide ore. The position of the peaks in the GLCM is an indication of the relative density (specific gravity, SG) of the minerals and when interpreted using a working knowledge of the mineralogy of the ore presented a means to determine the relative abundance of the sulfide minerals (SG > 4), dense silicate minerals (SG > 3), and lighter silicate minerals (SG < 3). The spread of the peaks in the GLCM away from the diagonal is an indication of the degree of grain boundary interaction with wide peaks representing fine grain sizes and narrow peaks representing coarse grain sizes. The method lends itself to application as part of a generic methodology for routine use on large XCT volumes providing quantitative, timely, meaningful and automated information on mineralogy and texture in 3D.

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.

AUC-based biomarker ensemble with an application on gene scores predicting low bone mineral density.

PubMed

Zhao, X G; Dai, W; Li, Y; Tian, L

2011-11-01

The area under the receiver operating characteristic (ROC) curve (AUC), long regarded as a 'golden' measure for the predictiveness of a continuous score, has propelled the need to develop AUC-based predictors. However, the AUC-based ensemble methods are rather scant, largely due to the fact that the associated objective function is neither continuous nor concave. Indeed, there is no reliable numerical algorithm identifying optimal combination of a set of biomarkers to maximize the AUC, especially when the number of biomarkers is large. We have proposed a novel AUC-based statistical ensemble methods for combining multiple biomarkers to differentiate a binary response of interest. Specifically, we propose to replace the non-continuous and non-convex AUC objective function by a convex surrogate loss function, whose minimizer can be efficiently identified. With the established framework, the lasso and other regularization techniques enable feature selections. Extensive simulations have demonstrated the superiority of the new methods to the existing methods. The proposal has been applied to a gene expression dataset to construct gene expression scores to differentiate elderly women with low bone mineral density (BMD) and those with normal BMD. The AUCs of the resulting scores in the independent test dataset has been satisfactory. Aiming for directly maximizing AUC, the proposed AUC-based ensemble method provides an efficient means of generating a stable combination of multiple biomarkers, which is especially useful under the high-dimensional settings. lutian@stanford.edu. Supplementary data are available at Bioinformatics online.

Assessment of bioavailability of pesticides in soils and identification of pesticide degradation drivers using the in-situ Mass Distribution Quotient (iMDQ)

NASA Astrophysics Data System (ADS)

Folberth, Christian

2010-05-01

The in-situ Mass Distribution Quotient (iMDQ) has recently been shown to reliably describe the bioavailability and mineralization of the widely applied pesticide isoproturon in agricultural soils. It is determined by pore water extraction from previously incubated soil samples and subsequent assessment of the mass distribution between solid and liquid phase. The method was verified by comparing the bioavailability with co-metabolic mineralization in soils under optimum microbial soil conditions (water tension -15 kPa and bulk density 1.3 g cm-3). A comparison of the results with the chemical partitioning assessed by the Kd method has shown a higher accuracy of the new method. By combining the iMDQ/pore water extraction method with mineralization of the pesticide under optimum microbial conditions in the soils, further information about mineralization and degradation processes could be obtained or confirmed: a) Metabolically outstanding soils could be identified due to inconsistency between bioavailability and mineralization when compared to the co-metabolic soils. In a metabolically hampered soil, the mineralization was very low compared to the bioavailability and in a soil with metabolically IPU degrading microorganisms the mineralization was extremely high despite low bioavailability. b) Analysis of metabolite patterns in soil water fractions of a degradation experiment allowed for an additional identification of the metabolic status of the soil. In co-metabolic soils, the diversity of metabolites increased proportionally with the degree of mineralization of the parent compound, whereas in a metabolically hampered soil the metabolite pattern was very diverse despite low mineralization. c) A quite stable fractioning between total mineralization of the parent compound to CO2 and build-up of non-extractable bound residues was found. This is a hint that also during co-metabolic degradation that can up to now not be attributed to a certain group of microorganisms, very similar processes take place in different soils. d) It could be shown that soil parameters governing the bioavailability of the compound differ between soils. Although TOC and pH could again be identified as the most important factors for the sorption strength of soils towards isoproturon, the bioavailability itself was driven by a combination of water content and sorption strength that was unique for each soil sample. f) The partitioning of parent compound and primary metabolites remained quite stable during the degradation and mineralization. Further investigations focusing on the microbial side of co-metabolic degradation are in progress. In the future, the method could be used to investigate more compounds, the effectiveness of methods to increase bioavailability in-situ without the need for degradation experiments, and the identification and analysis of degradation pathways in-situ. Other processes that are important for risk assessment, like leaching, have already been investigated with similar methods.

Micro-computed tomographic analysis of progression of artificial enamel lesions in primary and permanent teeth after resin infiltration.

PubMed

Ozgul, Betul Memis; Orhan, Kaan; Oz, Firdevs Tulga

2015-09-01

We investigated inhibition of lesion progression in artificial enamel lesions. Lesions were created on primary and permanent anterior teeth (n = 10 each) and were divided randomly into two groups with two windows: Group 1 (window A: resin infiltration; window B: negative control) and Group 2 (window A: resin infiltration + fluoride varnish; window B: fluoride varnish). After pH cycling, micro-computed tomography was used to analyze progression of lesion depth and changes in mineral density. Resin infiltration and resin infiltration + fluoride varnish significantly inhibited progression of lesion depth in primary teeth (P < 0.05). Inhibition of lesion depth progression in permanent teeth was significantly greater after treatment with resin infiltration + fluoride varnish than in the negative control (P < 0.05). Change in mineral density was smaller in the resin infiltration and resin infiltration + fluoride varnish groups; however, the difference was not significant for either group (P > 0.05). Resin infiltration is a promising method of inhibiting progression of caries lesions.

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.

Some suggested future directions of quantitative resource assessments

USGS Publications Warehouse

Singer, D.A.

2001-01-01

Future quantitative assessments will be expected to estimate quantities, values, and locations of undiscovered mineral resources in a form that conveys both economic viability and uncertainty associated with the resources. Historically, declining metal prices point to the need for larger deposits over time. Sensitivity analysis demonstrates that the greatest opportunity for reducing uncertainty in assessments lies in lowering uncertainty associated with tonnage estimates. Of all errors possible in assessments, those affecting tonnage estimates are by far the most important. Selecting the correct deposit model is the most important way of controlling errors because the dominance of tonnage-deposit models are the best known predictor of tonnage. Much of the surface is covered with apparently barren rocks and sediments in many large regions. Because many exposed mineral deposits are believed to have been found, a prime concern is the presence of possible mineralized rock under cover. Assessments of areas with resources under cover must rely on extrapolation from surrounding areas, new geologic maps of rocks under cover, or analogy with other well-explored areas that can be considered training tracts. Cover has a profound effect on uncertainty and on methods and procedures of assessments because geology is seldom known and geophysical methods typically have attenuated responses. Many earlier assessment methods were based on relationships of geochemical and geophysical variables to deposits learned from deposits exposed on the surface-these will need to be relearned based on covered deposits. Mineral-deposit models are important in quantitative resource assessments for two reasons: (1) grades and tonnages of most deposit types are significantly different, and (2) deposit types are present in different geologic settings that can be identified from geologic maps. Mineral-deposit models are the keystone in combining the diverse geoscience information on geology, mineral occurrences, geophysics, and geochemistry used in resource assessments and mineral exploration. Grade and tonnage models and development of quantitative descriptive, economic, and deposit density models will help reduce the uncertainty of these new assessments.

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

Pediatric data for dual X-ray absorptiometric measures of normal lumbar bone mineral density in children under 5 years of age using the lunar prodigy densitometer.

PubMed

Manousaki, D; Rauch, F; Chabot, G; Dubois, J; Fiscaletti, M; Alos, N

2016-09-07

Knowledge of physiological variations of bone mineral density (BMD) in newborns and infants is necessary to evaluate pathological changes associated with fractures. Limited reference data for children under 5 years old are available. This study provides normative data of lumbar BMD for the Lunar Prodigy in young children under 5 years old. We assessed cross-sectionally 155 healthy children (77 boys, 80% Caucasian), ranging in age from newborn to the age of 5 years. Lumbar bone mineral content (BMC) and areal BMD were measured by dual-energy X-ray absorptiometry using a Lunar Prodigy absorptiometer. Volumetric BMD was calculated using the Kroeger and Carter methods. BMC and areal BMD increased from birth to 5 years (p<0.001). Volumetric BMD did not change with age. BMD and BMC correlated with age, weight and height (R(2)≥0.85 for all), with a maximum gain between the ages of 1 and 4 years, which did not follow the same pattern as height velocity. We did not find significant sex difference for any of the three measured parameters. This study provides normative data for lumbar spine densitometry of infants and young children using the Lunar Prodigy DXA system.

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...

Two-dimensional imaging of two types of radicals by the CW-EPR method

NASA Astrophysics Data System (ADS)

Czechowski, Tomasz; Krzyminiewski, Ryszard; Jurga, Jan; Chlewicki, Wojciech

2008-01-01

The CW-EPR method of image reconstruction is based on sample rotation in a magnetic field with a constant gradient (50 G/cm). In order to obtain a projection (radical density distribution) along a given direction, the EPR spectra are recorded with and without the gradient. Deconvolution, then gives the distribution of the spin density. Projection at 36 different angles gives the information that is necessary for reconstruction of the radical distribution. The problem becomes more complex when there are at least two types of radicals in the sample, because the deconvolution procedure does not give satisfactory results. We propose a method to calculate the projections for each radical, based on iterative procedures. The images of density distribution for each radical obtained by our procedure have proved that the method of deconvolution, in combination with iterative fitting, provides correct results. The test was performed on a sample of polymer PPS Br 111 ( p-phenylene sulphide) with glass fibres and minerals. The results indicated a heterogeneous distribution of radicals in the sample volume. The images obtained were in agreement with the known shape of the sample.

Association Between Polymorphisms of VDR, COL1A1, and LCT genes and bone mineral density in Belarusian women with severe postmenopausal osteoporosis.

PubMed

Marozik, Pavel; Mosse, Irma; Alekna, Vidmantas; Rudenko, Ema; Tamulaitienė, Marija; Ramanau, Heorhi; Strazdienė, Vaidilė; Samokhovec, Volha; Ameliyanovich, Maxim; Byshnev, Nikita; Gonchar, Alexander; Kundas, Liubov; Zhur, Krystsina

2013-01-01

BACKGROUND AND OBJECTIVE. Variation of osteoporosis in the population is the result of an interaction between the genotype and the environment, and the genetic causes of osteoporosis are being widely investigated. The aim of this study was to analyze the association between the polymorphisms of the vitamin D receptor (VDR), type I collagen (COL1A1), and lactase (LCT) genes and severe postmenopausal osteoporosis as well as bone mineral density (BMD). MATERIAL AND METHODS. A total of 54 women with severe postmenopausal osteoporosis and 77 controls (mean age, 58.3 years [SD, 6.2] and 56.7 years [SD, 7.42], respectively) were included into the study. The subjects were recruited at the City Center for Osteoporosis Prevention (Minsk, Belarus). Dual-energy x-ray absorptiometry was used to measure bone mineral density at the lumbar spine and the femoral neck. Severe osteoporosis was diagnosed in the women with the clinical diagnosis of postmenopausal osteoporosis and at least 1 fragility fracture. The control group included women without osteoporosis. Polymorphic sites in osteoporosis predisposition genes (ApaI, BsmI, TaqI, and Cdx2 of the VDR gene, G2046T of the COL1A1 gene, and T-13910C of the LCT gene) were determined using the polymerase chain reaction on the deoxyribonucleic acid isolated from dried bloodspots. RESULTS. The data showed that the ApaI and BsmI polymorphisms of the VDR gene and T- 13910C of the LCT gene were associated with severe postmenopausal osteoporosis in the analyzed Belarusian women (P<0.01). A statistically significant positive correlation between the VDR risk genotypes ApaI and TaqI and bone mineral density was found (P<0.05). CONCLUSIONS. The findings of this study suggest that at least the ApaI and BsmI polymorphisms of the VDR gene and T-13910C of the LCT gene are associated with the risk of postmenopausal osteoporosis in our sample of the Belarusian women.

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.

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.

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.

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

Nucleic acid extraction from polluted estuarine water for detection of viruses and bacteria by PCR and RT-PCR analysis.

PubMed

Petit, F; Craquelin, S; Guespin-Michel, J; Buffet-Janvresse, C

1999-03-01

We describe an extraction protocol for genomic DNA and RNA of both viruses and bacteria from polluted estuary water. This procedure was adapted to the molecular study of microflora of estuarine water where bacteria and viruses are found free, forming low-density biofilms, or intimately associated with organo-mineral particles. The sensitivity of the method was determined with seeded samples for RT-PCR and PCR analysis of viruses (10 virions/mL), and bacteria (1 colony-forming unit mL). We report an example of molecular detection of both poliovirus and Salmonella in the Seine estuary (France) and an approach to studying their association with organo-mineral particles.

Adsorption of organic molecules on mineral surfaces studied by first-principle calculations: A review.

PubMed

Zhao, Hongxia; Yang, Yong; Shu, Xin; Wang, Yanwei; Ran, Qianping

2018-04-09

First-principle calculations, especially by the density functional theory (DFT) methods, are becoming a power technique to study molecular structure and properties of organic/inorganic interfaces. This review introduces some recent examples on the study of adsorption models of organic molecules or oligomers on mineral surfaces and interfacial properties obtained from first-principles calculations. The aim of this contribution is to inspire scientists to benefit from first-principle calculations and to apply the similar strategies when studying and tailoring interfacial properties at the atomistic scale, especially for those interested in the design and development of new molecules and new products. Copyright © 2017. Published by Elsevier B.V.

A Model for Partitioning CO2 Flux and Calculating Transformation of Soil C Fractions

NASA Astrophysics Data System (ADS)

Zhang, S.; Noormets, A.; Tu, C.; King, J.

2011-12-01

It has been recognized that mechanistic understanding of soil organic carbon (SOC) mineralization requires partitioning of SOM to different sub-pools, whose turnover kinetics differ. Different fractionation methods have been developed to separate and analyze SOC fractions with different turnover rates, but some recent studies have called to questions earlier assumptions about chemical structure of C compounds and their recalcitrance to decomposition. To our knowledge, there is also no model that would bring together the information on various indicators of recalcitrance in a kinetic model framework . Here we deploy an analytical framework to partition soil net CO2 emissions to three density fractions (F1, F2, and F3, in the order of increasing density) in a peat soil and follow mineralization-related transformations (from lighter to heavier fractions). We followed the changes in total C content [C] and 13C of each three density fractions through a 3-month incubation study. We partitioned the CO2 produced by the soil between the different fractions using 13C and [C] change data. Applying this approach to a factorial experiment, we found that partitioning of CO2 emission and transformation rates among fractions differed between the organic top soil and deeper sandy soil. At depth of 45-75cm, almost no C was released through CO2 emission for all three fractions, while at 0-30cm, emission reached 0.2 g C/g soil over the incubation period, an average of 99% of which was from F2. Mineralization-related transformation rate at 45-75cm was 0.02 g soil/g soil with no significant differences among fractions. At 0-30cm, out of one gram of initial bulk soil, an average of 0.31g F1 transformed to F2, whereas no F2 was transformed to F3. Although the current study was carried out on a high-organic soil, the partitioning method is applicable to all soil types.

Relationships between bone mineral density and new indices of body composition in young, sedentary men and women.

PubMed

Kęska, Anna; Lutosławska, Grażyna; Bertrandt, Jerzy; Sobczak, Małgorzata

2018-03-14

Data concerning the relationship between body fat and BMD are equivocal since both positive and negative effects have been noted. Recently, the index of fat mass (IFM) representing subjects with different body fat and similar lean mass and index of lean mass (ILM) representing subjects with different lean body mass and similar body fat, have been used to evaluate body composition effect on BMD in middle-aged women. This study aimed at determination of ILM and IFM association with BMD in young men and women. A total of 212 university students of Public Health (125 women and 87 men) participated in the study. Body composition was determined by the bioelectrical impedance method (BIA) using BC 418 MA equipment (Tanita Co., Japan). Fat mass and fat free mass were used to calculate ILM and IFM. Bone mineral density was measured on the wrist of the non-dominant hand using the DEXA method and EXA 3000 equipment (HFS Ltd., Korea). BMD was evaluated using Z-score, with values lower than -2.0 indicating inadequate BMD for subject chronological age. Exclusively in women, IFM was markedly and positively correlated with Z-score (r=0.366, P<0.001). In both genders, a significant relationship was found between ILM and Z-scores (r=0.420; p<0.001 and r=0.220; p<0.02 in men and women, respectively). Women with lower than median IFM but similar ILM, were characterized by significantly lower Z-scores vs. women with higher IFM (-1.016 vs. -0.512; p<0.001). Irrespective of gender, participants with higher ILM but similar IFM, were characterized by markedly higher Z-score vs. their counterparts with low ILM. The use of IFM and ILM in the present study, allowed the observation that in young adults lean body mass was associated with BMD, regardless of gender, while fat mass is significant for bone mineral density only in women.

Clinical practice guidelines for the diagnosis and management of osteoporosis. Scientific Advisory Board, Osteoporosis Society of Canada.

PubMed Central

1996-01-01

OBJECTIVE: To recommend clinical practice guidelines for the assessment of people at risk for osteoporosis, and for effective diagnosis and management of the condition. OPTIONS: Screening and diagnostic methods: risk-factor assessment, clinical evaluation, measurement of bone mineral density, laboratory investigations. Prophylactic and corrective therapies: calcium and vitamin D nutritional supplementation, physical activity and fall-avoidance techniques, ovarian hormone therapy, bisphosphonate drugs, other drug therapies. Pain-management medications and techniques. OUTCOMES: Prevention of loss of bone mineral density and fracture; increased bone mass; and improved quality of life. EVIDENCE: Epidemiologic and clinical studies and reports were examined, with emphasis on recent randomized controlled trials. Clinical practice in Canada and elsewhere was surveyed. Availability of treatment products and diagnostic equipment in Canada was considered. VALUES: Cost-effective methods and products that can be adopted across Canada were considered. A high value was given to accurate assessment of fracture risk and osteoporosis, and to increasing bone mineral density, reducing fractures and fracture risk and minimizing side effects of diagnosis and treatment. BENEFITS, HARMS AND COSTS: Proper diagnosis and management of osteoporosis minimize injury and disability, improve quality of life for patients and reduce costs to society. Rationally targeted methods of screening and diagnosis are safe and cost effective. Harmful side effects and costs of recommended therapies are minimal compared with the harms and costs of untreated osteoporosis. Alternative therapies provide a range of choices for physicians and patients. RECOMMENDATIONS: Population sets at high risk should be identified and then the diagnosis confirmed through bone densitometry. Dual-energy x-ray absorptiometry is the preferred measurement technique. Radiography can be adjunct when indicated. Calcium and vitamin D nutritional supplementation should be at currently recommended levels. Patients should be counselled in fall-avoidance techniques and exercises. Immobilization should be avoided. Guidelines for management of acute pain are listed. Ovarian hormone therapy is the therapy of choice for osteoporosis prevention and treatment in postmenopausal women. Bisphosphonates are an alternative therapy for women with established osteoporosis who cannot or prefer not to take ovarian hormone therapy. PMID:8873639

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.

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.

QEMSCAN+LA-ICP-MS: a 'big data' generator for sedimentary provenance analysis

NASA Astrophysics Data System (ADS)

Vermeesch, Pieter; Rittner, Martin; Garzanti, Eduardo

2017-04-01

Sedimentary provenance may be traced by 'fingerprinting' sediments with chemical, mineralogical or isotopic means. Normally, each of these provenance proxies is characterised on a separate aliquot of the same sample. For example, the chemical composition of the bulk sample may be analysed by X-ray fluorescence (XRF) on one aliquot, framework petrography on another, heavy mineral analysis on a density separate of a third split, and zircon U-Pb dating on a further density separate of the heavy mineral fraction. The labour intensity of this procedure holds back the widespread application of multi-method provenance studies. We here present a new method to solve this problem and avoid mineral separation by coupling a QEMSCAN electron microscope to an LA-ICP-MS instrument and thereby generate all four aforementioned provenance datasets as part of the same workflow. Given a polished hand specimen, a petrographic thin section, or a grain mount, the QEMSCAN+LA-ICP-MS method produces chemical and mineralogical maps from which the X-Y coordinates of the datable mineral are extracted. These coordinates are subsequently passed on to the laser ablation system for isotopic and, hence, geochronological analysis. In the process of finding all the zircons in a sediment grain mount, the QEMSCAN yields the compositional and mineralogical compositions as byproducts. We have applied the new QEMSCAN+LA-ICP-MS instrument suite to over 100 samples from three large sediment routing systems: (1) the Tigris-Euphrates river catchments and Rub' Al Khali desert in Arabia; (2) the Nile catchment in northeast Africa and (3) desert and beach sands between the Orange and Congo rivers in southwest Africa. These studies reveal (1) that Rub' Al Khali sand is predominantly derived from the Arabian Shield and not from Mesopotamia; (2) that the Blue Nile is the principal source of Nile sand; and (3) that Orange River sand is carried northward by longshore drift nearly 1,800km from South Africa to southern Angola. In addition to these geological findings, the first applications of QEMSCAN+LA-ICP-MS highlight some key advantages of the new workflow over traditional provenance analysis: (a) the new method not only increases sample throughput but also improves data quality by reducing significant biases associated with mineral separation and grain selection; (b) the three case studies highlight the importance of zircon 'fertility' for interpreting detrital zircon U-Pb datasets, and the ability of QEMSCAN to quantify this crucial parameter semi-automatically; (c) QEMSCAN+LA-ICP-MS provides an opportunity to add textural information to detrital geochronology and, for example, quantify possible grain-size dependence of U-Pb age distributions. But besides these advantages, the three case studies also reveal a number of limitations: (a) mineral identification by QEMSCAN is not as reliable as commonly achieved by human observers; (b) heavy mineral compositions obtained by QEMSCAN cannot easily be compared with conventional point counting data; and (c) apparent grain sizes can be greatly affected by polishing artefacts. In conclusion, QEMSCAN+LA-ICP-MS is a transformational new technique for provenance analysis but should be used with caution, in combination with conventional petrographic and heavy mineral techniques.

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

[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.

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.

DXA in the assessment of subchondral bone mineral density in knee osteoarthritis--A semi-standardized protocol after systematic review.

PubMed

Sepriano, Alexandre; Roman-Blas, Jorge A; Little, Robert D; Pimentel-Santos, Fernando; Arribas, Jose María; Largo, Raquel; Branco, Jaime C; Herrero-Beaumont, Gabriel

2015-12-01

Subchondral bone mineral density (sBMD) contributes to the initiation and progression of knee osteoarthritis (OA). Reliable methods to assess sBMD status may predict the response of specific OA phenotypes to targeted therapies. While dual-energy X-ray absorptiometry (DXA) of the knee can determine sBMD, no consensus exists regarding its methodology. Construct a semi-standardized protocol for knee DXA to measure sBMD in patients with OA of the knee by evaluating the varying methodologies present in existing literature. We performed a systematic review of original papers published in PubMed and Web of Science from their inception to July 2014 using the following search terms: subchondral bone, osteoarthritis, and bone mineral density. DXA of the knee can be performed with similar reproducibility values to those proposed by the International Society for Clinical Densitometry for the hip and spine. We identified acquisition view, hip rotation, knee positioning and stabilization, ROI location and definition, and the type of analysis software as important sources of variation. A proposed knee DXA protocol was constructed taking into consideration the results of the review. DXA of the knee can be reliably performed in patients with knee OA. Nevertheless, we found substantial methodological variation across previous studies. Methodological standardization may provide a foundation from which to establish DXA of the knee as a valid tool for identification of SB changes and as an outcome measure in clinical trials of disease modifying osteoarthritic drugs. Copyright © 2015 Elsevier Inc. All rights reserved.

Boron removal by electrocoagulation and recovery.

PubMed

Isa, Mohamed Hasnain; Ezechi, Ezerie Henry; Ahmed, Zubair; Magram, Saleh Faraj; Kutty, Shamsul Rahman Mohamed

2014-03-15

This work investigated the removal of boron from wastewater and its recovery by electrocoagulation and hydrothermal mineralization methods respectively. The experimental design was developed using Box-Behnken Model. An initial study was performed based on four preselected variables (pH, current density, concentration and time) using synthetic wastewater. Response surface methodology (RSM) was used to evaluate the effect of process variables and their interaction on boron removal. The optimum conditions were obtained as pH 6.3, current density 17.4 mA/cm(2), and time 89 min. At these applied optimum conditions, 99.7% boron removal from an initial concentration of 10.4 mg/L was achieved. The process was effectively optimized by RSM with a desirability value of 1.0. The results showed that boron removal efficiency enhanced with increase in current density and treatment time. Removal efficiency also increased when pH was increased from 4 to 7 and subsequently decreased at pH 10. Adsorption kinetics study revealed that the reaction followed pseudo second order kinetic model; evidenced by high correlation and goodness of fit. Thermodynamics study showed that mechanism of boron adsorption was chemisorption and the reaction was endothermic in nature. Furthermore, the adsorption process was spontaneous as indicated by negative values of the adsorption free energy. Treatment of real produced water using electrocoagulation resulted in 98% boron removal. The hydrothermal mineralization study showed that borate minerals (Inyoite, Takadaite and Nifontovite) can be recovered as recyclable precipitate from electrocoagulation flocs of produced water. Copyright © 2013 Elsevier Ltd. All rights reserved.

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.

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 ...

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.

The acid-base titration of montmorillonite

NASA Astrophysics Data System (ADS)

Bourg, I. C.; Sposito, G.; Bourg, A. C.

2003-12-01

Proton binding to clay minerals plays an important role in the chemical reactivity of soils (e.g., acidification, retention of nutrients or pollutants). If should also affect the performance of clay barriers for waste disposal. The surface acidity of clay minerals is commonly modelled empirically by assuming generic amphoteric surface sites (>SOH) on a flat surface, with fitted site densities and acidity constant. Current advances in experimental methods (notably spectroscopy) are rapidly improving our understanding of the structure and reactivity of the surface of clay minerals (arrangement of the particles, nature of the reactive surface sites, adsorption mechanisms). These developments are motivated by the difficulty of modelling the surface chemistry of mineral surfaces at the macro-scale (e.g., adsorption or titration) without a detailed (molecular-scale) picture of the mechanisms, and should be progressively incorporated into surface complexation models. In this view, we have combined recent estimates of montmorillonite surface properties (surface site density and structure, edge surface area, surface electrostatic potential) with surface site acidities obtained from the titration of alpha-Al2O3 and SiO2, and a novel method of accounting for the unknown initial net proton surface charge of the solid. The model predictions were compared to experimental titrations of SWy-1 montmorillonite and purified MX-80 bentonite in 0.1-0.5 mol/L NaClO4 and 0.005-0.5 mol/L NaNO3 background electrolytes, respectively. Most of the experimental data were appropriately described by the model after we adjusted a single parameter (silanol sites on the surface of montmorillonite were made to be slightly more acidic than those of silica). At low ionic strength and acidic pH the model underestimated the buffering capacity of the montmorillonite, perhaps due to clay swelling or to the interlayer adsorption of dissolved aluminum. The agreement between our model and the experimental data illustrates the complementarity of molecular and macro-scale descriptions of the clay reactivity.

Quantitative Computed Tomography (QCT) derived Bone Mineral Density (BMD) in finite element studies: a review of the literature.

PubMed

Knowles, Nikolas K; Reeves, Jacob M; Ferreira, Louis M

2016-12-01

Finite element modeling of human bone provides a powerful tool to evaluate a wide variety of outcomes in a highly repeatable and parametric manner. These models are most often derived from computed tomography data, with mechanical properties related to bone mineral density (BMD) from the x-ray energy attenuation provided from this data. To increase accuracy, many researchers report the use of quantitative computed tomography (QCT), in which a calibration phantom is used during image acquisition to improve the estimation of BMD. Since model accuracy is dependent on the methods used in the calculation of BMD and density-mechanical property relationships, it is important to use relationships developed for the same anatomical location and using the same scanner settings, as these may impact model accuracy. The purpose of this literature review is to report the relationships used in the conversion of QCT equivalent density measures to ash, apparent, and/or tissue densities in recent finite element (FE) studies used in common density-modulus relationships. For studies reporting experimental validation, the validation metrics and results are presented. Of the studies reviewed, 29% reported the use of a dipotassium phosphate (K 2 HPO 4 ) phantom, 47% a hydroxyapatite (HA) phantom, 13% did not report phantom type, 7% reported use of both K 2 HPO 4 and HA phantoms, and 4% alternate phantom types. Scanner type and/or settings were omitted or partially reported in 31% of studies. The majority of studies used densitometric and/or density-modulus relationships derived from different anatomical locations scanned in different scanners with different scanner settings. The methods used to derive various densitometric relationships are reported and recommendations are provided toward the standardization of reporting metrics. This review assessed the current state of QCT-based FE modeling with use of clinical scanners. It was found that previously developed densitometric relationships vary by anatomical location, scanner type and settings. Reporting of all parameters used when referring to previously developed relationships, or in the development of new relationships, may increase the accuracy and repeatability of future FE models.

Nickeltalmessite, Ca2Ni(AsO4)2 · 2H2O, a new mineral species of the fairfieldite group, Bou Azzer, Morocco

NASA Astrophysics Data System (ADS)

Chukanov, N. V.; Mukhanova, A. A.; Möckel, S.; Belakovsky, D. I.; Levitskaya, L. A.

2010-12-01

Nickeltalmessite, Ca2Ni(AsO4)2 · 2H2O, a new mineral species of the fairfieldite group, has been found in association with annabergite, nickelaustinite, pecoraite, calcite, and a mineral of the chromite-manganochromite series from the dump of the Aït Ahmane Mine, Bou Azzer ore district, Morocco. The new mineral occurs as spheroidal aggregates consisting of split crystals up to 10 × 10 × 20 μm in size. Nickeltalmessite is apple green, with white streak and vitreous luster. The density measured by the volumetric method is 3.72(3) g/cm3; calculated density is 3.74 g/cm3. The new mineral is colorless under a microscope, biaxial, positive: α = 1.715(3), β = 1.720(5), γ = 1.753(3), 2 V meas = 80(10)°, 2 V calc = 60.4. Dispersion is not observed. The infrared spectrum is given. As a result of heating of the mineral in vacuum from 24° up to 500°C, weight loss was 8.03 wt %. The chemical composition (electron microprobe, wt %) is as follows: 25.92 CaO, 1.23 MgO, 1.08 CoO, 13.01 NiO, 52.09 As2O5; 7.8 H2O (determined by the Penfield method); the total is 101.13. The empirical formula calculated on the basis of two AsO4 groups is Ca2.04(Ni0.77Mg0.13Co0.06)Σ0.96 (AsO4)2.00 · 1.91H2O. The strongest reflections in the X-ray powder diffraction pattern [ d, Å ( I, %) ( hkl)] are: 5.05 (27) (001) (100), 3.57 (43) (011), 3.358 (58) (110), 3.202 (100) (020), 3.099 (64) (0 bar 2 1), 2.813 (60), ( bar 1 21), 2.772 (68) (2 bar 1 0), 1.714 (39) ( bar 3 31). The unit-cell dimensions of the triclinic lattice (space group P1 or P) determined from the X-ray powder data are: a = 5.858(7), b = 7.082(12), c = 5.567(6) Å, α = 97.20(4), β = 109.11(5), γ = 109.78(5)°, V = 198.04 Å3, Z = 1. The mineral name emphasizes its chemical composition as a Ni-dominant analogue of talmessite. The type material of nickeltalmessite is deposited at the Fersman Mineralogical Museum, Russian Academy of Sciences, Moscow, Russia, registration number 3750/1.

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

Bone Mineral Density in Adolescent Girls with Hypogonadotropic and Hypergonadotropic Hypogonadism

PubMed Central

Özbek, Mehmet Nuri; Demirbilek, Hüseyin; Baran, Rıza Taner; Baran, Ahmet

2016-01-01

Objective: Deficiency of sex steroids has a negative impact on bone mineral content. In studies conducted on postmenopausal women and animal studies, elevated follicle-stimulating hormone (FSH) levels were found to be correlated with a decrease in bone mineralization and osteoporosis. The aim of the present study was to evaluate bone mineral density (BMD) in adolescent girls with hypogonadotropic and hypergonadotropic hypogonadism and also to investigate the correlation between FSH level and BMD. Methods: The study group included 33 adolescent girls with hypogonadism (14 with hypogonadotropic hypogonadism and 19 with hypergonadotropic hypogonadism). FSH, luteinizing hormone, estradiol levels, and BMD (using dual energy x-ray absorptiometry) were measured. Results: There were no statistically significant differences between the chronological age and bone age of the two patient groups, namely, with hypogonadotropic and hypergonadotropic hypogonadism. There was also no significant difference between BMD z-score values obtained from measurements from the spine and the femur neck of patients in the two groups (p-values were 0.841 and 0.281, respectively). In the hypergonadotropic group, a moderately negative correlation was detected between FSH level and BMD z-score measured from the femur neck (ρ=-0.69, p=0.001), whilst no correlation was observed between FSH levels and height adjusted BMD-z scores measured from the spine (ρ=0.17, p=0.493). FSH level was not found to be an independent variable affecting BMD z-score. Conclusion: BMD z-scores were detected to be similar in adolescent girls with hypogonadotropic and hypergonadotropic hypogonadism, and FSH levels were not found to have a clinically relevant impact on BMD. PMID:27087454

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.

Bone mineral density and body composition of the United States Olympic women's field hockey team

PubMed Central

Sparling, P. B.; Snow, T. K.; Rosskopf, L. B.; O'Donnell, E. M.; Freedson, P. S.; Byrnes, W. C.

1998-01-01

OBJECTIVE: To evaluate total bone mineral density (BMD) and body composition (% fat) in world class women field hockey players, members of the 1996 United States Olympic team. METHODS: Whole body BMD (g/cm2) and relative body fatness (% fat) were assessed by dual energy x ray absorptiometry using a Lunar DPX-L unit with software version 1.3z. Body composition was also estimated by hydrostatic weighing and the sum of seven skinfolds. Results: Mean (SD) BMD was 1.253 (0.048) g/cm2 which is 113.2 (4.0)% of age and weight adjusted norms. Estimates of body composition from the three methods were similar (statistically non- significant): 16.1 (4.4)% fat from dual energy x ray absorptiometry, 17.6 (3.2)% from hydrostatic weighing, and 16.9 (2.6)% from the sum of seven skinfolds. Mean fat free mass was approximately 50 kg. CONCLUSIONS: The mean whole body BMD value for members of the 1996 United States Olympic women's field hockey team is one of the highest reported for any women's sports team. Moreover, the mean fat free mass per unit height was quite high and % fat was low. In this group of world class sportswomen, low % fat was not associated with low BMD. 




 PMID:9865404

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

A mineral separation procedure using hot Clerici solution

USGS Publications Warehouse

Rosenblum, Sam

1974-01-01

Careful boiling of Clerici solution in a Pyrex test tube in an oil bath is used to float minerals with densities up to 5.0 in order to obtain purified concentrates of monazite (density 5.1) for analysis. The "sink" and "float" fractions are trapped in solidified Clerici salts on rapid chilling, and the fractions are washed into separate filter papers with warm water. The hazardous nature of Clerici solution requires unusual care in handling.

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.

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.

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.

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.

Assessment of BoneTtissue Mineralization by Conventional X-ray Microcomputed tomography: Comparison with Synchrotron Radiation Microcomputed Tomography and Ash Measurements

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

Kazakia,G.; Burghardt, A.; Cheung, S.

2008-01-01

Assessment of bone tissue mineral density (TMD) may provide information critical to the understanding of mineralization processes and bone biomechanics. High-resolution three-dimensional assessment of TMD has recently been demonstrated using synchrotron radiation microcomputed tomography (SR{mu}CT); however, this imaging modality is relatively inaccessible due to the scarcity of SR facilities. Conventional desktop {mu}CT systems are widely available and have been used extensively to assess bone microarchitecture. However, the polychromatic source and cone-shaped beam geometry complicate assessment of TMD by conventional {mu}CT. The goal of this study was to evaluate {mu}CT-based measurement of degree and distribution of tissue mineralization in a quantitative,more » spatially resolved manner. Specifically, {mu}CT measures of bone mineral content (BMC) and TMD were compared to those obtained by SR{mu}CT and gravimetric methods. Cylinders of trabecular bone were machined from human femoral heads (n=5), vertebrae (n=5), and proximal tibiae (n=4). Cylinders were imaged in saline on a polychromatic {mu}CT system at an isotropic voxel size of 8 {mu}m. Volumes were reconstructed using beam hardening correction algorithms based on hydroxyapatite (HA)-resin wedge phantoms of 200 and 1200 mgHA/cm3. SR{mu}CT imaging was performed at an isotropic voxel size of 7.50 {mu}m at the National Synchrotron Light Source. Attenuation values were converted to HA concentration using a linear regression derived by imaging a calibration phantom. Architecture and mineralization parameters were calculated from the image data. Specimens were processed using gravimetric methods to determine ash mass and density. {mu}CT-based BMC values were not affected by altering the beam hardening correction. Volume-averaged TMD values calculated by the two corrections were significantly different (p=0.008) in high volume fraction specimens only, with the 1200 mgHA/cm3 correction resulting in a 4.7% higher TMD value. {mu}CT and SR{mu}CT provided significantly different measurements of both BMC and TMD (p<0.05). In high volume fraction specimens, {mu}CT with 1200 mgHA/cm3 correction resulted in BMC and TMD values 16.7% and 15.0% lower, respectively, than SR{mu}CT values. In low volume fraction specimens, {mu}CT with 1200 mgHA/cm3 correction resulted in BMC and TMD values 12.8% and 12.9% lower, respectively, than SR{mu}CT values. {mu}CT and SR{mu}CT values were well-correlated when volume fraction groups were considered individually (BMC R2=0.97-1.00; TMD R2=0.78-0.99). Ash mass and density were higher than the SR{mu}CT equivalents by 8.6% in high volume fraction specimens and 10.9% in low volume fraction specimens (p<0.05). BMC values calculated by tomography were highly correlated with ash mass (ash versus {mu}CT R2=0.96-1.00; ash versus SR{mu}CT R2=0.99-1.00). TMD values calculated by tomography were moderately correlated with ash density (ash versus {mu}CT R2=0.64-0.72; ash versus SR{mu}CT R2=0.64). Spatially resolved comparisons highlighted substantial geometric nonuniformity in the {mu}CT data, which were reduced (but not eliminated) using the 1200 mg HA/cm3 beam hardening correction, and did not exist in the SR{mu}CT data. This study represents the first quantitative comparison of {mu}CT mineralization evaluation against SR{mu}CT and gravimetry. Our results indicate that {mu}CT mineralization measures are underestimated but well-correlated with SR{mu}CT and gravimetric data, particularly when volume fraction groups are considered individually.« less

Assessment of bone tissue mineralization by conventional x-ray microcomputed tomography: Comparison with synchrotron radiation microcomputed tomography and ash measurements

PubMed Central

Kazakia, G. J.; Burghardt, A. J.; Cheung, S.; Majumdar, S.

2008-01-01

Assessment of bone tissue mineral density (TMD) may provide information critical to the understanding of mineralization processes and bone biomechanics. High-resolution three-dimensional assessment of TMD has recently been demonstrated using synchrotron radiation microcomputed tomography (SRμCT); however, this imaging modality is relatively inaccessible due to the scarcity of SR facilities. Conventional desktop μCT systems are widely available and have been used extensively to assess bone microarchitecture. However, the polychromatic source and cone-shaped beam geometry complicate assessment of TMD by conventional μCT. The goal of this study was to evaluate μCT-based measurement of degree and distribution of tissue mineralization in a quantitative, spatially resolved manner. Specifically, μCT measures of bone mineral content (BMC) and TMD were compared to those obtained by SRμCT and gravimetric methods. Cylinders of trabecular bone were machined from human femoral heads (n=5), vertebrae (n=5), and proximal tibiae (n=4). Cylinders were imaged in saline on a polychromatic μCT system at an isotropic voxel size of 8 μm. Volumes were reconstructed using beam hardening correction algorithms based on hydroxyapatite (HA)-resin wedge phantoms of 200 and 1200 mg HA∕cm3. SRμCT imaging was performed at an isotropic voxel size of 7.50 μm at the National Synchrotron Light Source. Attenuation values were converted to HA concentration using a linear regression derived by imaging a calibration phantom. Architecture and mineralization parameters were calculated from the image data. Specimens were processed using gravimetric methods to determine ash mass and density. μCT-based BMC values were not affected by altering the beam hardening correction. Volume-averaged TMD values calculated by the two corrections were significantly different (p=0.008) in high volume fraction specimens only, with the 1200 mg HA∕cm3 correction resulting in a 4.7% higher TMD value. μCT and SRμCT provided significantly different measurements of both BMC and TMD (p<0.05). In high volume fraction specimens, μCT with 1200 mg HA∕cm3 correction resulted in BMC and TMD values 16.7% and 15.0% lower, respectively, than SRμCT values. In low volume fraction specimens, μCT with 1200 mg HA∕cm3 correction resulted in BMC and TMD values 12.8% and 12.9% lower, respectively, than SRμCT values. μCT and SRμCT values were well-correlated when volume fraction groups were considered individually (BMC R2=0.97−1.00; TMD R2=0.78−0.99). Ash mass and density were higher than the SRμCT equivalents by 8.6% in high volume fraction specimens and 10.9% in low volume fraction specimens (p<0.05). BMC values calculated by tomography were highly correlated with ash mass (ash versus μCT R2=0.96−1.00; ash versus SRμCT R2=0.99−1.00). TMD values calculated by tomography were moderately correlated with ash density (ash versus μCT R2=0.64−0.72; ash versus SRμCT R2=0.64). Spatially resolved comparisons highlighted substantial geometric nonuniformity in the μCT data, which were reduced (but not eliminated) using the 1200 mg HA∕cm3 beam hardening correction, and did not exist in the SRμCT data. This study represents the first quantitative comparison of μCT mineralization evaluation against SRμCT and gravimetry. Our results indicate that μCT mineralization measures are underestimated but well-correlated with SRμCT and gravimetric data, particularly when volume fraction groups are considered individually. PMID:18697542

Determination of element affinities by density fractionation of bulk coal samples

USGS Publications Warehouse

Querol, X.; Klika, Z.; Weiss, Z.; Finkelman, R.B.; Alastuey, A.; Juan, R.; Lopez-Soler, A.; Plana, F.; Kolker, A.; Chenery, S.R.N.

2001-01-01

A review has been made of the various methods of determining major and trace element affinities for different phases, both mineral and organic in coals, citing their various strengths and weaknesses. These include mathematical deconvolution of chemical analyses, direct microanalysis, sequential extraction procedures and density fractionation. A new methodology combining density fractionation with mathematical deconvolution of chemical analyses of whole coals and their density fractions has been evaluated. These coals formed part of the IEA-Coal Research project on the Modes of Occurrence of Trace Elements in Coal. Results were compared to a previously reported sequential extraction methodology and showed good agreement for most elements. For particular elements (Be, Mo, Cu, Se and REEs) in specific coals where disagreement was found, it was concluded that the occurrence of rare trace element bearing phases may account for the discrepancy, and modifications to the general procedure must be made to account for these.

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.

Hydrogen concentration analysis in clinopyroxene using proton-proton scattering analysis

NASA Astrophysics Data System (ADS)

Weis, Franz A.; Ros, Linus; Reichart, Patrick; Skogby, Henrik; Kristiansson, Per; Dollinger, Günther

2018-02-01

Traditional methods to measure water in nominally anhydrous minerals (NAMs) are, for example, Fourier transformed infrared (FTIR) spectroscopy or secondary ion mass spectrometry (SIMS). Both well-established methods provide a low detection limit as well as high spatial resolution yet may require elaborate sample orientation or destructive sample preparation. Here we analyze the water content in erupted volcanic clinopyroxene phenocrysts by proton-proton scattering and reproduce water contents measured by FTIR spectroscopy. We show that this technique provides significant advantages over other methods as it can provide a three-dimensional distribution of hydrogen within a crystal, making the identification of potential inclusions possible as well as elimination of surface contamination. The sample analysis is also independent of crystal structure and orientation and independent of matrix effects other than sample density. The results are used to validate the accuracy of wavenumber-dependent vs. mineral-specific molar absorption coefficients in FTIR spectroscopy. In addition, we present a new method for the sample preparation of very thin crystals suitable for proton-proton scattering analysis using relatively low accelerator potentials.

Bone mineralization changes of the glenoid in shoulders with symptomatic rotator cuff tear.

PubMed

Harada, Yohei; Yokoya, Shin; Akiyama, Yuji; Mochizuki, Yu; Ochi, Mitsuo; Adachi, Nobuo

2018-06-06

Computed tomography osteoabsorptiometry (CTO) is a method to analyze the stress distribution in joints by measuring the subchondral bone density. The purpose of this study was to evaluate the bone mineralization changes of the glenoid in shoulders with rotator cuff tears by CTO and to evaluate whether rotator cuff tears are associated with stress changes in the glenoid. In total, 32 patients, who were diagnosed with unilateral rotator cuff tears and underwent arthroscopic rotator cuff repair, were enrolled in this study. They underwent CT scanning of both shoulders pre-operatively and the glenoid was evaluated using CTO. Hounsfield units (HU) in seven areas of the glenoid were compared between the affected and unaffected sides. The central area of the glenoid on the affected side had significantly lower HU than on the unaffected side among all patients. Focusing on the rotator cuff tear size and the subscapularis tendon, only patients with larger cuff tears or with subscapularis tendon tears showed significantly lower HU in the central area of the affected side. This study showed a decrease in bone mineralization density in the central glenoid in shoulders with rotator cuff tear. This change was observed in the case of larger cuff tears and subscapularis tendon tears. Our results help clarify the changes in stress distribution in the shoulder joint caused by symptomatic rotator cuff tears.

Computational Evaluation of Mg–Salen Compounds as Subsurface Fluid Tracers: Molecular Dynamics Simulations in Toluene–Water Mixtures and Clay Mineral Nanopores

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

Greathouse, Jeffery A.; Boyle, Timothy J.; Kemp, Richard A.

Molecular tracers that can be selectively placed underground and uniquely identified at the surface using simple on-site spectroscopic methods would significantly enhance subsurface fluid monitoring capabilities. To ensure their widespread utility, the solubility of these tracers must be easily tuned to oil- or water-wet conditions as well as reducing or eliminating their propensity to adsorb onto subsurface rock and/or mineral phases. In this work, molecular dynamics simulations were used to investigate the relative solubilities and mineral surface adsorption properties of three candidate tracer compounds comprising Mg–salen derivatives of varying degrees of hydrophilic character. Simulations in water–toluene liquid mixtures indicate thatmore » the partitioning of each Mg–salen compound relative to the interface is strongly influenced by the degree of hydrophobicity of the compound. Simulations of these complexes in fluid-filled mineral nanopores containing neutral (kaolinite) and negatively charged (montmorillonite) mineral surfaces reveal that adsorption tendencies depend upon a variety of parameters, including tracer chemical properties, mineral surface type, and solvent type (water or toluene). Simulation snapshots and averaged density profiles reveal insight into the solvation and adsorption mechanisms that control the partitioning of these complexes in mixed liquid phases and nanopore environments. As a result, this work demonstrates the utility of molecular simulation in the design and screening of molecular tracers for use in subsurface applications.« less

Computational Evaluation of Mg–Salen Compounds as Subsurface Fluid Tracers: Molecular Dynamics Simulations in Toluene–Water Mixtures and Clay Mineral Nanopores

DOE PAGES

Greathouse, Jeffery A.; Boyle, Timothy J.; Kemp, Richard A.

2018-04-11

Molecular tracers that can be selectively placed underground and uniquely identified at the surface using simple on-site spectroscopic methods would significantly enhance subsurface fluid monitoring capabilities. To ensure their widespread utility, the solubility of these tracers must be easily tuned to oil- or water-wet conditions as well as reducing or eliminating their propensity to adsorb onto subsurface rock and/or mineral phases. In this work, molecular dynamics simulations were used to investigate the relative solubilities and mineral surface adsorption properties of three candidate tracer compounds comprising Mg–salen derivatives of varying degrees of hydrophilic character. Simulations in water–toluene liquid mixtures indicate thatmore » the partitioning of each Mg–salen compound relative to the interface is strongly influenced by the degree of hydrophobicity of the compound. Simulations of these complexes in fluid-filled mineral nanopores containing neutral (kaolinite) and negatively charged (montmorillonite) mineral surfaces reveal that adsorption tendencies depend upon a variety of parameters, including tracer chemical properties, mineral surface type, and solvent type (water or toluene). Simulation snapshots and averaged density profiles reveal insight into the solvation and adsorption mechanisms that control the partitioning of these complexes in mixed liquid phases and nanopore environments. As a result, this work demonstrates the utility of molecular simulation in the design and screening of molecular tracers for use in subsurface applications.« less

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.

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.

Association of the g.19074G>A genetic variant in the osteoprotegerin gene with bone mineral density in Chinese postmenopausal women.

PubMed

Zhang, Y D; Zhang, Z; Zhou, N F; Jia, W T; Cheng, X G; Wei, X J

2014-08-28

Primary osteoporosis is a common health problem in postmenopausal women. This study aimed to detect the association of the g.19074G>A genetic variant in the osteoprotegerin gene (OPG) with bone mineral density (BMD) and primary osteoporosis. The created restriction site-polymerase chain reaction method was used to investigate the g.19074G>A genetic variant. The BMD of the femoral neck hip, lumbar spine (L2-4), and total hip were assessed by dual-energy X-ray absorptiometry (DEXA) in 856 unrelated Chinese postmenopausal women. We found significant differences in the BMDs of the femoral neck hip, lumbar spine (L2-4), and total hip among different genotypes; individuals with the GG genotype had significantly higher BMDs than those with the GA and AA genotypes (P < 0.05). Our results indicated that the A allele was an increased risk factor for primary osteoporosis and the g.19074G>A genetic variant of the OPG gene was associated with BMD and primary osteoporosis in Chinese postmenopausal women.

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.

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.

Cost-effectiveness of different strategies for selecting and treating individuals at increased risk of osteoporosis or osteopenia: a systematic review.

PubMed

Müller, Dirk; Pulm, Jannis; Gandjour, Afschin

2012-01-01

To compare cost-effectiveness modeling analyses of strategies to prevent osteoporotic and osteopenic fractures either based on fixed thresholds using bone mineral density or based on variable thresholds including bone mineral density and clinical risk factors. A systematic review was performed by using the MEDLINE database and reference lists from previous reviews. On the basis of predefined inclusion/exclusion criteria, we identified relevant studies published since January 2006. Articles included for the review were assessed for their methodological quality and results. The literature search resulted in 24 analyses, 14 of them using a fixed-threshold approach and 10 using a variable-threshold approach. On average, 70% of the criteria for methodological quality were fulfilled, but almost half of the analyses did not include medication adherence in the base case. The results of variable-threshold strategies were more homogeneous and showed more favorable incremental cost-effectiveness ratios compared with those based on a fixed threshold with bone mineral density. For analyses with fixed thresholds, incremental cost-effectiveness ratios varied from €80,000 per quality-adjusted life-year in women aged 55 years to cost saving in women aged 80 years. For analyses with variable thresholds, the range was €47,000 to cost savings. Risk assessment using variable thresholds appears to be more cost-effective than selecting high-risk individuals by fixed thresholds. Although the overall quality of the studies was fairly good, future economic analyses should further improve their methods, particularly in terms of including more fracture types, incorporating medication adherence, and including or discussing unrelated costs during added life-years. Copyright © 2012 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

The Impact of Low-Dose Disease-modifying Anti-rheumatics Drugs (DMARDs) on Bone Mineral Density of Premenopausal Women in Early Rheumatoid Arthritis

PubMed Central

Rexhepi, Sylejman; Rexhepi, Mjellma; Sahatçiu-Meka, Vjollca; Mahmutaj, Vigan; Boshnjaku, Shkumbin

2016-01-01

Introduction: Rheumatoid arthritis (RA) is a chronic inflammatory disease characterized by symmetrical polyarthritis and multisystemic involvement. Objective: The aim of this study was to assess the impact of low dose of methotrexate on bone mineral density (BMD) in patients with early rheumatoid arthritis (RA). Materials and methods: This paper follows a retrospective study, which involves 60 female patients with early onset RA diagnosed according to the American Rheumatism Association Criteria (ACR/EULAR 2010). The patients were divided into two groups group I was composed of thirty patients treated with dose of 7.5 mg/weekly methotrexate (MTX), while group II included thirty patients treated with dose of 2 g/daily sulfasalazine (SSZ). The Disease Activity was measured by a combination of Erythrocyte Sedimentation Rate (ESR) and Disease Activity Score (DAS-28). Bone mineral density of the lumbar spine (L2–4), and femoral neck, was measured by dual energy X-ray absorptiometry (DEXA) (Stratos 800). Laboratory findings included: In this study, we found no negative effect on BMD in RA patients treated with low dose MTX in comparison to patients treated with SSZ. There was not observed significant difference in BMD of the lumbar spine, femur neck or trochanter, of MTX and SSZ patients in the pretreatment phase, nor after 12 months of treatment. No significant change in the biochemical parameters of the both groups. Conclusion: Based on the results of our study, low dose of methotrexate has no negative effect on BMD in premenopausal RA patients. We believe that these results might provide new insights and that further longitudinal studies with larger groups of premenopausal RA patients are required. PMID:27147781

Independent external validation of nomograms for predicting risk of low-trauma fracture and hip fracture

PubMed Central

Langsetmo, Lisa; Nguyen, Tuan V.; Nguyen, Nguyen D.; Kovacs, Christopher S.; Prior, Jerilynn C.; Center, Jacqueline R.; Morin, Suzanne; Josse, Robert G.; Adachi, Jonathan D.; Hanley, David A.; Eisman, John A.

2011-01-01

Background A set of nomograms based on the Dubbo Osteoporosis Epidemiology Study predicts the five- and ten-year absolute risk of fracture using age, bone mineral density and history of falls and low-trauma fracture. We assessed the discrimination and calibration of these nomograms among participants in the Canadian Multicentre Osteoporosis Study. Methods We included participants aged 55–95 years for whom bone mineral density measurement data and at least one year of follow-up data were available. Self-reported incident fractures were identified by yearly postal questionnaire or interview (years 3, 5 and 10). We included low-trauma fractures before year 10, except those of the skull, face, hands, ankles and feet. We used a Cox proportional hazards model. Results Among 4152 women, there were 583 fractures, with a mean follow-up time of 8.6 years. Among 1606 men, there were 116 fractures, with a mean follow-up time of 8.3 years. Increasing age, lower bone mineral density, prior fracture and prior falls were associated with increased risk of fracture. For low-trauma fractures, the concordance between predicted risk and fracture events (Harrell C) was 0.69 among women and 0.70 among men. For hip fractures, the concordance was 0.80 among women and 0.85 among men. The observed fracture risk was similar to the predicted risk in all quintiles of risk except the highest quintile of women, where it was lower. The net reclassification index (19.2%, 95% confidence interval [CI] 6.3% to 32.2%), favours the Dubbo nomogram over the current Canadian guidelines for men. Interpretation The published nomograms provide good fracture-risk discrimination in a representative sample of the Canadian population. PMID:21173069

Prediction of incident hip fracture by femoral neck bone mineral density and neck–shaft angle: a 5-year longitudinal study in post-menopausal females

PubMed Central

Gnudi, S; Sitta, E; Pignotti, E

2012-01-01

Objective To compare hip fracture incidence in post-menopausal females who were differently stratified for the fracture risk according to bone mineral density and proximal femur geometry. Methods In a 5 year follow-up study, the hip fracture incidence in 729 post-menopausal females (45 of whom suffered from incident hip fracture) was assessed and compared. Forward logistic regression was used to select independent predictors of hip fracture risk, including age, age at menopause, height, weight, femoral neck bone mineral density (FNBMD), neck–shaft angle (NSA), hip axis length, femoral neck diameter and femoral shaft diameter as covariates. Fracture incidence was then calculated for the categories of young/old age, high/low FNBMD and wide/narrow NSA, which were obtained by dichotomising each hip fracture independent predictor at the value best separating females with and without a hip fracture. Results The hip fracture incidence of the whole cohort was significantly higher in females with a wide NSA (8.52%) than in those with a narrow NSA (3.51%). The combination of wide NSA and low FNBMD had the highest hip fracture incidence in the whole cohort (17.61%) and each age category. The combinations of narrow/wide NSA with low/high FNBMD, respectively, gave a significantly higher fracture incidence in older than in younger women, whereas women with a combined wide NSA and low FNBMD had no significantly different fracture incidence in young (14.60%) or old age (21.62%). Conclusion Our study showed that NSA is effective at predicting the hip fracture risk and that the detection in early post-menopause of a wide NSA together with a low FNBMD should identify females at high probability of incident hip fracture. PMID:22096224

A hospital based study of biochemical markers of bone turnovers & bone mineral density in north Indian women

PubMed Central

Kumar, Ashok; Devi, Salam Gyaneshwori; Mittal, Soniya; Shukla, Deepak Kumar; Sharma, Shashi

2013-01-01

Background & objectives: The osteoporotic risk for women increases soon after menopause. Bone turnover markers are known to be associated with bone loss and fracture risk. This study was aimed to assess bone turnover using bone markers and their correlation with bone mineral density (BMD) in pre- and post-menopausal women. Methods: A total of 255 healthy women (160 pre- and 95 post-menopausal) were enrolled. Serum bone alkaline phosphatase (sBAP) and serum N-terminal telopeptide of type I collagen (NTX) were measured to evaluate the bone formation and resorption, respectively. Bone mineral density was determined at lumbar spine (L2-L4) anteroposteriorly, femoral neck and Ward's triangle using Prodigy dual-energy X-ray absorptiometry (DXA) system. The comparison of years since menopause with respect to BMD and bone markers was also evaluated. Results: NTX and sBAP showed significant negative correlation with BMD of femur neck and Ward's triangle in postmenopausal women. BMD of all three sides were significant variables for NTX and BMD of femur neck and Ward's triangle for sBAP in postmenopausal women. BMD lumbar spine was a significant variable for sBAP in premenopausal women. The mean values of NTX increased significantly with increase in the duration of years since menopause. The BMD of all three sides decreased significantly with increase in the duration of years since menopause. Interpretation & conclusions: Serum NTX and sBAP were inversely correlated to BMD of femur neck and Ward's triangle in post-menopausal women. Simultaneous measurements of NTX and BMD in the north Indian women, suggest that bone resorption in women with low BMD remains high after menopause. PMID:23481051

The choice of normative pediatric reference database changes spine bone mineral density Z-scores but not the relationship between bone mineral density and prevalent vertebral fractures.

PubMed

Ma, Jinhui; Siminoski, Kerry; Alos, Nathalie; Halton, Jacqueline; Ho, Josephine; Lentle, Brian; Matzinger, MaryAnn; Shenouda, Nazih; Atkinson, Stephanie; Barr, Ronald; Cabral, David A; Couch, Robert; Cummings, Elizabeth A; Fernandez, Conrad V; Grant, Ronald M; Rodd, Celia; Sbrocchi, Anne Marie; Scharke, Maya; Rauch, Frank; Ward, Leanne M

2015-03-01

Our objectives were to assess the magnitude of the disparity in lumbar spine bone mineral density (LSBMD) Z-scores generated by different reference databases and to evaluate whether the relationship between LSBMD Z-scores and vertebral fractures (VF) varies by choice of database. Children with leukemia underwent LSBMD by cross-calibrated dual-energy x-ray absorptiometry, with Z-scores generated according to Hologic and Lunar databases. VF were assessed by the Genant method on spine radiographs. Logistic regression was used to assess the association between fractures and LSBMD Z-scores. Net reclassification improvement and area under the receiver operating characteristic curve were calculated to assess the predictive accuracy of LSBMD Z-scores for VF. For the 186 children from 0 to 18 years of age, 6 different age ranges were studied. The Z-scores generated for the 0 to 18 group were highly correlated (r ≥ 0.90), but the proportion of children with LSBMD Z-scores ≤-2.0 among those with VF varied substantially (from 38-66%). Odds ratios (OR) for the association between LSBMD Z-score and VF were similar regardless of database (OR = 1.92, 95% confidence interval 1.44, 2.56 to OR = 2.70, 95% confidence interval 1.70, 4.28). Area under the receiver operating characteristic curve and net reclassification improvement ranged from 0.71 to 0.75 and -0.15 to 0.07, respectively. Although the use of a LSBMD Z-score threshold as part of the definition of osteoporosis in a child with VF does not appear valid, the study of relationships between BMD and VF is valid regardless of the BMD database that is used.

[Effects of the nutritional education and dietary intervention on nutritional status and bone mineral density of middle-aged and senile patients with osteoporosis].

PubMed

Zhao, Chunyan; Zhou, Ruihua; Tian, Yongzhi; Tang, Yongmei; Ning, Hongzhen; Liu, Haiyan

2016-03-01

To study the effect of the nutritional education and dietary intervention on nutritional status and bone mineral density (BMD) of middle-aged and senile patients with osteoporosis. Ninty middle-aged and senile osteoporosis patients were enrolled. They were randomly divided into two groups (intervention and control group) with 45 cases each. The control group was received conventional therapy and the intervention group added with nutritional education and dietary intervention for six months on the basis of conventional therapy. The methods of education and intervention included seminars, brochures distribution, dietary survey and individual guidance. The nutritional status and BMD were analyzed at the beginning and the end of the intervention respectively. After the intervention, the ratios of subjects whose intake of grain, vegetables, fruits, eggs, milk and beans in line with recommended intake of the intervention group were higher than those of the control group (P < 0.05). After the intervention, frequencies of coarse grain, dairy, beans and seafood consumption of the intervention group were higher than those of the control group (P < 0.05). After the intervention, the daily intakes of protein, VA, VC, calcium, zinc, magnesium, dietary fiber of the intervention group were significantly superior to the control group (P < 0.05). BMDs of lumbar spine and femoral neck in the intervention group were significantly higher than those in the control group (P < 0.05). The nutritional education and dietary intervention could promote middle-aged and senile patients' reasonable diet, improve their nutritional status, enhance bone mineral density and improve the effect of conventional therapy for osteoporosis.

Baseline characteristics and outcome in Romanian patients with Gaucher disease type 1.

PubMed

Grigorescu-Sido, Paula; Drugan, Cristina; Alkhzouz, Camelia; Zimmermann, Anca; Coldea, Cristina; Denes, Carmen; Grigorescu, Mircea Dan; Cret, Victoria; Bucerzan, Simona

2010-04-01

To present clinical and genetic characteristics of all Romanian patients with Gaucher disease type 1, in whom specific diagnosis has been confirmed by enzymatic and molecular methods and to analyze their outcome with and without enzymatic replacement therapy (ERT). There are fifty patients (F/M - 1.63/1) with Gaucher disease type 1. Clinical status, haemoglobin, thrombocytes, hepatic/splenic volume, bone mineral density and severity score were assessed at baseline and every six months thereafter. Thirty-nine patients (78%) received imiglucerase (44.4+/-13.6 U/kg/2 weeks) for 3.1+/-1.4 years. Based on general prevalence data, our group represents 22.7% of the expected total number of patients with Gaucher disease type 1 in Romania. Mean age was 15.5 years at clinical onset and 28.9 years at confirmation of diagnosis. The genotype N370S/L444P was frequent in our group (35.9% of alleles). Anaemia, thrombocytopenia, splenomegaly and bone disease were present at 38%, 70%, 100% and 84%, respectively. Mean values for haemoglobin, thrombocytes, hepatic volume and chitotriosidase normalized after 0.5, 1.5, 2.5 and 3 years of ERT, respectively. Splenomegaly regressed from 14.4 x N (normal) to 3.06 x N over four years of treatment. Bone disease was ameliorated under ERT, yet bone mineral density worsened in patients treated with 30 U/kg/2 weeks. The genotype N370S/L444P is frequent in our patients, in line with the severe phenotypes. ERT improved haematological parameters and visceromegaly, without a clear benefit for bone mineral density. To attain therapeutic goals, an early treatment start with optimal dosage is mandatory. Copyright 2009 Elsevier B.V. All rights reserved.

Bone mass of female dance students prior to professional dance training: A cross-sectional study

PubMed Central

Amorim, Tânia; Metsios, George S.; Wyon, Matthew; Nevill, Alan M.; Flouris, Andreas D.; Maia, José; Teixeira, Eduardo; Machado, José Carlos; Marques, Franklim; Koutedakis, Yiannis

2017-01-01

Background Professional dancers are at risk of developing low bone mineral density (BMD). However, whether low BMD phenotypes already exist in pre-vocational dance students is relatively unknown. Aim To cross-sectionally assess bone mass parameters in female dance students selected for professional dance training (first year vocational dance students) in relation to aged- and sex-matched controls. Methods 34 female selected for professional dance training (10.9yrs ±0.7) and 30 controls (11.1yrs ±0.5) were examined. Anthropometry, pubertal development (Tanner) and dietary data (3-day food diary) were recorded. BMD and bone mineral content (BMC) at forearm, femur neck (FN) and lumbar spine (LS) were assessed using Dual-Energy X-Ray Absorptiometry. Volumetric densities were estimated by calculating bone mineral apparent density (BMAD). Results Dancers were mainly at Tanner pubertal stage I (vs. stage IV in controls, p<0.001), and demonstrated significantly lower body weight (p<0.001) and height (p<0.01) than controls. Calorie intake was not different between groups, but calcium intake was significantly greater in dancers (p<0.05). Dancers revealed a significantly lower BMC and BMD values at all anatomical sites (p<0.001), and significantly lower BMAD values at the LS and FN (p<0.001). When adjusted for covariates (body weight, height, pubertal development and calcium intake), dance students continued to display a significantly lower BMD and BMAD at the FN (p<0.05; p<0.001) at the forearm (p<0.01). Conclusion Before undergoing professional dance training, first year vocational dance students demonstrated inferior bone mass compared to controls. Longitudinal models are required to assess how bone health-status changes with time throughout professional training. PMID:28678833

Fracture Risk and Areal Bone Mineral Density in Adolescent Females with Anorexia Nervosa

PubMed Central

Faje, Alexander T.; Fazeli, Pouneh K.; Miller, Karen K.; Katzman, Debra K.; Ebrahimi, Seda; Lee, Hang; Mendes, Nara; Snelgrove, Deirdre; Meenaghan, Erinne; Misra, Madhusmita; Klibanski, Anne

2014-01-01

Objective To (i) compare fracture prevalence in adolescent females with anorexia nervosa (AN) vs. normal-weight controls and (ii) examine whether reductions in areal bone mineral density (aBMD) predict fracture risk in females with AN. Methods 418 females (310 with active AN and 108 normal-weight controls) 12–22 years old were studied cross-sectionally. Lifetime fracture history was recorded by a physician during participant interviews. Body composition and aBMD measurements of the whole body, whole body less head, lumbar spine, and hip were assessed by dual-energy x-ray absorptiometry (DXA), and bone mineral apparent density (BMAD) was calculated for the lumbar spine. Results Participants with AN and normal-weight controls did not differ for chronological age, sexual maturity, or height. The lifetime prevalence of prior fracture was 59.8% higher in those with AN compared to controls (31.0 % versus 19.4 %, p = 0.02), and the fracture incidence rate peaked in our cohort after the diagnosis of AN. Lower aBMD and lumbar BMAD were not associated with a higher prevalence of fracture in the AN or control group on univariate or multivariate analyses. Compared to controls, fracture prevalence was significantly higher in the subgroup of girls with AN who had normal aBMD or only modest reductions of aBMD (Z-scores > −1 or −1.5). Discussion This is the first study to show that the risk of fracture during childhood and adolescence is significantly higher in patients with AN than in normal-weight controls. Fracture prevalence is increased in this cohort of subjects with AN even without significant reductions in aBMD. PMID:24430890

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

Ossicular density in golden moles (Chrysochloridae).

PubMed

Mason, Matthew J; Lucas, Sarah J; Wise, Erica R; Stein, Robin S; Duer, Melinda J

2006-12-01

The densities of middle ear ossicles of golden moles (family Chrysochloridae, order Afrosoricida) were measured using the buoyancy method. The internal structure of the malleus was examined by high-resolution computed tomography, and solid-state NMR was used to determine relative phosphorus content. The malleus density of the desert golden mole Eremitalpa granti (2.44 g/cm3) was found to be higher than that reported in the literature for any other terrestrial mammal, whereas the ossicles of other golden mole species are not unusually dense. The increased density in Eremitalpa mallei is apparently related both to a relative paucity of internal vascularization and to a high level of mineralization. This high density is expected to augment inertial bone conduction, used for the detection of seismic vibrations, while limiting the skull modifications needed to accommodate the disproportionately large malleus. The mallei of the two subspecies of E. granti, E. g. granti and E. g. namibensis, were found to differ considerably from one another in both size and shape.

Low Bone Mineral Mass Is Associated with Decreased Bone Formation and Diet in Females with Rett Syndrome

PubMed Central

Motil, Kathleen J.; Barrish, Judy O.; Neul, Jeffrey L.; Glaze, Daniel G.

2014-01-01

Objective To characterize biomarkers of bone turnover and their relation with bone mineral mass in a cross-sectional cohort of females with Rett syndrome (RTT) and to examine the role of dietary, biochemical, hormonal, and inflammatory factors on bone mineral mass and bone biomarkers in this disorder. Methods Total body bone mineral content (BMC) and density (BMD) were determined by dual-energy x-ray absorptiometry. Dietary nutrient intakes were determined from 3-day food records. Biomarkers of bone turnover, bone metabolites, vitamin D metabolites, hormones, and inflammatory markers were measured by standard clinical laboratory methods. Results Serum osteocalcin, bone alkaline phosphatase, and C-telopeptide showed significant inverse relations with age in the RTT cohort. Mean osteocalcin concentrations were significantly lower and mean bone alkaline phosphatase concentrations were significantly higher for individual age groups in the RTT cohort than mean values for their respective age ranges in the reference population. Significant inverse associations were identified between urinary calcium losses, expressed as calcium:creatinine ratios, and total body BMC and BMD z-scores. Dietary protein, calcium, and phosphorus intakes, expressed as a proportion of Dietary Reference Intakes for age and gender, showed significant positive associations with total body BMD z-scores. Conclusion This study suggests decreased bone formation rather than increased bone resorption may explain in part the deficits in bone mineral mass in RTT and that attention to the adequacy of dietary protein, calcium and phosphorus intakes may offer an opportunity to improve bone health in RTT. PMID:25144778

3D visualization and quantification of bone and teeth mineralization for the study of osteo/dentinogenesis in mice models

NASA Astrophysics Data System (ADS)

Marchadier, A.; Vidal, C.; Ordureau, S.; Lédée, R.; Léger, C.; Young, M.; Goldberg, M.

2011-03-01

Research on bone and teeth mineralization in animal models is critical for understanding human pathologies. Genetically modified mice represent highly valuable models for the study of osteo/dentinogenesis defects and osteoporosis. Current investigations on mice dental and skeletal phenotype use destructive and time consuming methods such as histology and scanning microscopy. Micro-CT imaging is quicker and provides high resolution qualitative phenotypic description. However reliable quantification of mineralization processes in mouse bone and teeth are still lacking. We have established novel CT imaging-based software for accurate qualitative and quantitative analysis of mouse mandibular bone and molars. Data were obtained from mandibles of mice lacking the Fibromodulin gene which is involved in mineralization processes. Mandibles were imaged with a micro-CT originally devoted to industrial applications (Viscom, X8060 NDT). 3D advanced visualization was performed using the VoxBox software (UsefulProgress) with ray casting algorithms. Comparison between control and defective mice mandibles was made by applying the same transfer function for each 3D data, thus allowing to detect shape, colour and density discrepencies. The 2D images of transverse slices of mandible and teeth were similar and even more accurate than those obtained with scanning electron microscopy. Image processing of the molars allowed the 3D reconstruction of the pulp chamber, providing a unique tool for the quantitative evaluation of dentinogenesis. This new method is highly powerful for the study of oro-facial mineralizations defects in mice models, complementary and even competitive to current histological and scanning microscopy appoaches.

Spectral methods to detect cometary minerals with OSIRIS on board Rosetta

NASA Astrophysics Data System (ADS)

Oklay, N.; Vincent, J.-B.; Sierks, H.

2013-09-01

Comet 67P/Churyumov-Gerasimenko is going to be observed by the OSIRIS scientific imager (Keller et al. 2007) on board ESA's spacecraft Rosetta in the wavelength range of 250-1000 nm with a combination of 12 filters for the narrow angle camera (NAC) and 14 combination of 12 filters for the narrow angle camera (NAC) and 14 filters in the wavelength range of 240-720 nm for the wide angle camera (WAC). NAC filters are suitable to surface composition studies, while WAC filters are designed for gas and radical emission studies. In order to investigate the composition of the comet surface from the observed images, we need to understand how to detect different minerals and which compositional information can be derived from the NAC filters. Therefore, the most common cometary silicates e.g. enstatite, forsterite are investigated with two hydrated silicates (serpentine and smectite) for the determina- tion of the spectral methods. Laboratory data of those selected minerals are collected from RELAB database (http://www.planetary.brown.edu/relabdocs/relab.htm) and absolute spectra of the minerals observed by OSIRIS NAC filters are calculated. Due to the limited spectral range of the laboratory data, Far-UV and Neutral density filters of NAC are excluded from this analysis. Considered NAC filters in this study are represented in Table 1 and the number of collected laboratory data are presented in Table 2. Detection and separation of the minerals will not only allow us to study the surface composition but also to study observed composition changes due to the cometary activity during the mission.

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.

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.

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.

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

Using oxidized liquid and solid human waste as nutrients for Chlorella vulgaris and cyanobacterium Oscillatoria deflexa

NASA Astrophysics Data System (ADS)

Trifonov, Sergey V.; Kalacheva, Galina; Tirranen, Lyalya; Gribovskaya, Iliada

At stationary terrestrial and space stations with closed and partially closed substance exchange not only plants, but also algae can regenerate atmosphere. Their biomass can be used for feeding Daphnia and Moina species, which, in their turn, serve as food for fish. In addition, it is possible to use algae for production of biological fuel. We suggested two methods of human waste mineralization: dry (evaporation with subsequent incineration in a muffle furnace) and wet (oxidation in a reactor using hydrogen peroxide). The research task was to prepare nutrient media for green alga Chlorella vulgaris and cyanobacterium Oscillatoria deflexa using liquid human waste mineralized by dry method, and to prepare media for chlorella on the basis of 1) liquid and 2) liquid and solid human waste mineralized by wet method. The algae were grown in batch culture in a climate chamber with the following parameters: illumination 7 klx, temperature 27-30 (°) C, culture density 1-2 g/l of dry weight. The control for chlorella was Tamiya medium, pH-5, and for oscillstoria — Zarrouk medium, pH-10. Maximum permissible concentrations of NaCl, Cl, urea (NH _{2}) _{2}CO, and native urine were established for algae. Missing ingredients (such as salts and acids) for experimental nutrient media were determined: their addition made it possible to obtain the biomass production not less than that in the control. The estimation was given of the mineral and biochemical composition of algae grown on experimental media. Microbiological test revealed absence of foreign microbial flora in experimental cultures.

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.

Use of a case manager to improve osteoporosis treatment after hip fracture: results of a randomized controlled trial.

PubMed

Majumdar, Sumit R; Beaupre, Lauren A; Harley, Charles H; Hanley, David A; Lier, Douglas A; Juby, Angela G; Maksymowych, Walter P; Cinats, John G; Bell, Neil R; Morrish, Donald W

2007-10-22

Patients who survive hip fracture are at high risk of recurrent fractures, but rates of osteoporosis treatment 1 year after sustaining a fracture are less than 10% to 20%. We have developed an osteoporosis case manager intervention. The case manager educated patients, arranged bone mineral density tests, provided prescriptions, and communicated with primary care physicians. The intervention was compared with usual care in a randomized controlled trial. We recruited from all hospitals that participate in the Capital Health system (Alberta, Canada), including patients 50 years or older who had sustained a hip fracture and excluding those who were receiving osteoporosis treatment or who lived in a long-term care facility. Primary outcome was bisphosphonate therapy 6 months after fracture; secondary outcomes included bone mineral density testing, appropriate care (bone mineral density testing and treatment if bone mass was low), and intervention costs. We screened 2219 patients and allocated 220, as follows: 110 to the intervention group and 110 to the control group. Median age was 74 years, 60% were women, and 37% reported having had previous fractures. Six months after hip fracture, 56 patients in the intervention group (51%) were receiving bisphosphonate therapy compared with 24 patients in the control group (22%) (adjusted odds ratio, 4.7; 95% confidence interval, 2.4-8.9; P < .001). Bone mineral density tests were performed in 88 patients in the intervention group (80%) vs 32 patients in the control group (29%) (P < .001). Of the 120 patients who underwent bone mineral density testing, 25 (21%) had normal bone mass. Patients in the intervention group were more likely to receive appropriate care than were patients in the control group (67% vs 26%; P < .001). The average intervention cost was $50.00 per patient. For a modest cost, a case manager was able to substantially increase rates of osteoporosis treatment in a vulnerable elderly population at high risk of future fractures.

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.

[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.

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.

The subchondral bone plate.

PubMed

Müller-Gerbl, M

1998-01-01

Pauwels (1965) and subsequent workers in the same field have shown that the distribution of the subchondral density within a joint surface can serve as a parametric measurement which reflects the main stress acting on a joint. Our own investigations on anatomical specimens have demonstrated that this subchondral mineralization does indeed show regular distribution patterns from which conclusions about the mechanical situation within an individual joint may be drawn. Since radiographical densitometry and histological methods are only available for determining the adaptive reaction of the bone to the particular mechanical situation in a joint after death, the information obtained applies only to an end situation and tells us nothing about the development of the changes with time. Furthermore, investigations carried out on human specimens by radiographical densitometry mostly apply to samples of a particular age, since such specimens can be acquired only from departments of pathology, forensic medicine or anatomy. The functional reactions of the bone tissue to repeated long-term changes in the loading--lengthy immobilization and subsequent remobilization, for instance, or heavy loading over a considerable period of time--cannot be followed by any ordinary method in experimental animals, since the death of the animal is a prerequisite for the precise quantitative examination of the bone tissue. This applies also to attempts to follow the process by means of animal experiments. CT OAM has been developed as a method which, based on CT, can provide a surface representation of the 3-D density distribution in the joints of living subjects. Comparative studies were carried out to establish and confirm the validity of the procedure. These have shown (1) that the results obtained from anatomical specimens are identical with those obtained in the living; (2) that secondary CT sections are suitable for evaluation and that the spectrum of joint surfaces examined can be extended to include the whole joint (if this were not so, effects caused by the apparatus--particularly the partial-volume effect--would render the procedure impossible); and finally (3) that the distribution of the Hounsfield density within the subchondral bone represents the distribution of the mineralization. The mineralization patterns found by us in different joints of normal subjects have shown that these patterns can be brought into line with current models of joint mechanics. The radiocarpal joint, for instance, has revealed the various types of loading occurring within physiological limits. Information has also been obtained about the age-related changes taking place in the hip, wrist and ankle joints. The increase of the total mineralization in gymnasts can be related to the qualitative and quantitative adaptation to an increased peak loading, and reduced mineralization to a lengthy reduction in use during, for instance, postoperative immobilization. In groups of patients with various diseases of mechanical origin (shoulder instability, malalignment of the main axis, defective repositioning of healed fractures, rupture of the rotator cuff, meniscectomy or rupture of the anterior cruciate ligament), a pattern of mineralization is found which is different from the normal picture. These findings reflect the abnormal mechanical situation. The mineralization pattern of the femoropatellar joint has revealed the differing etiologies of medial and lateral cartilage damage and the examination of patients with lunatomalacia has made it possible to recognize a genetic disposition. The postoperative comparison of the mineralization patterns of patients with genu varum who have undergone a correction osteotomy and the results of animal experiments on various procedures for reconstructing the anterior cruciate ligament or a primary replacement of the meniscus, have produced results which make it possible to judge the success or failure of the operation. (ABSTRACT TRUNCATED)

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

Applications of the First-principles LDA+Usc Method to Spin-crossover Minerals: the NAL Phase and (Mg,Fe)CO3 ferromagnesite

NASA Astrophysics Data System (ADS)

Hsu, H.

2016-12-01

Spin crossover (SCO) in iron-bearing minerals has attracted tremendous attention in recent years, as SCO usually leads to anomalous changes of the elastic, conducting, and thermodynamic properties of these minerals. Possible geophysical effects of SCO have been anticipated as well. With the development of the local density approximation + self-consistent Hubbard U (LDA+Usc) method, first-principles calculations have elucidated SCO in many lower-mantle minerals. The success of LDA+Usc lies in its capability to correctly identify the ground state in a wide pressure range and to accurately determine the mechanism of SCO, including the transition pressure PT. In this talk, two recent LDA+Usc studies of SCO minerals are presented: the "new aluminous (NAL) phase" [1] and (Mg,Fe)CO3 ferromagnesite [2]. The former is considered as a main host of aluminum in the subducted basalt and may be related to the seismic heterogeneities, and the latter is believed to be the major carbon carrier in the Earth's lower mantle and play a key role in the deep carbon cycle. For both minerals, the abrupt change of iron quadrupole splitting and the volume/elastic anomalies accompanying the SCO obtained in our calculations are in great agreement with experiments. Our calculations also suggest that the spin transition pressure PT in the NAL phase is not very sensitive to temperature, due to its nearly degenerate low-spin (LS) states, in contrast with (Mg,Fe)O ferropericlase and (Mg,Fe)CO3 systems, in which PT significantly increases with temperature. By examining the overall performance of the LDA+Usc method in the NAL phase and ferromagnesite, along with our previous calculations for ferropericlase and Fe-bearing MgSiO3 bridgmanite [3-5], we have established LDA+Usc a highly reliable method to study iron-bearing minerals and related materials under high pressure. [1] H. Hsu, in preparation. [2] S.-C. Huang and H. Hsu, Phys. Rev. B (Rapid Comm.), in press. [3] H. Hsu and R. M. Wentzcovitch, Phys. Rev. B 90, 195205 (2014). [4] H. Hsu et al., Earth Planet. Sci. Lett. 359-360, 34 (2012). [5] H. Hsu et al., Phys. Rev. Lett. 106, 118501 (2011).

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.

[Imaging of diabetic osteopathy].

PubMed

Patsch, J; Pietschmann, P; Schueller-Weidekamm, C

2015-04-01

Diabetic bone diseases are more than just osteoporosis in patients with diabetes mellitus (DM): a relatively high bone mineral density is paired with a paradoxically high risk of fragility fractures. Diabetics exhibit low bone turnover, osteocyte dysfunction, relative hypoparathyroidism and an accumulation of advanced glycation end products in the bone matrix. Besides typical insufficiency fractures, diabetics show a high risk for peripheral fractures of the lower extremities (e.g. metatarsal fractures). The correct interdisciplinary assessment of fracture risks in patients with DM is therefore a clinical challenge. There are two state of the art imaging methods for the quantification of fracture risks: dual energy X-ray absorptiometry (DXA) and quantitative computed tomography (QCT). Radiography, multidetector computed tomography (MDCT) and magnetic resonance imaging (MRI) are suitable for the detection of insufficiency fractures. Novel research imaging techniques, such as high-resolution peripheral quantitative computed tomography (HR-pQCT) provide non-invasive insights into bone microarchitecture of the peripheral skeleton. Using MR spectroscopy, bone marrow composition can be studied. Both methods have been shown to be capable of discriminating between type 2 diabetic patients with and without prevalent fragility fractures and thus bear the potential of improving the current standard of care. Currently both methods remain limited to clinical research applications. DXA and HR-pQCT are valid tools for the quantification of bone mineral density and assessment of fracture risk in patients with DM, especially if interpreted in the context of clinical risk factors. Radiography, CT and MRI are suitable for the detection of insufficiency fractures.

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.

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

Bone-marrow densitometry: Assessment of marrow space of human vertebrae by single energy high resolution-quantitative computed tomography

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

Peña, Jaime A.; Damm, Timo; Bastgen, Jan

Purpose: Accurate noninvasive assessment of vertebral bone marrow fat fraction is important for diagnostic assessment of a variety of disorders and therapies known to affect marrow composition. Moreover, it provides a means to correct fat-induced bias of single energy quantitative computed tomography (QCT) based bone mineral density (BMD) measurements. The authors developed new segmentation and calibration methods to obtain quantitative surrogate measures of marrow-fat density in the axial skeleton. Methods: The authors developed and tested two high resolution-QCT (HR-QCT) based methods which permit segmentation of bone voids in between trabeculae hypothesizing that they are representative of bone marrow space. Themore » methods permit calculation of marrow content in units of mineral equivalent marrow density (MeMD). The first method is based on global thresholding and peeling (GTP) to define a volume of interest away from the transition between trabecular bone and marrow. The second method, morphological filtering (MF), uses spherical elements of different radii (0.1–1.2 mm) and automatically places them in between trabeculae to identify regions with large trabecular interspace, the bone-void space. To determine their performance, data were compared ex vivo to high-resolution peripheral CT (HR-pQCT) images as the gold-standard. The performance of the methods was tested on a set of excised human vertebrae with intact bone marrow tissue representative of an elderly population with low BMD. Results: 86% (GTP) and 87% (MF) of the voxels identified as true marrow space on HR-pQCT images were correctly identified on HR-QCT images and thus these volumes of interest can be considered to be representative of true marrow space. Within this volume, MeMD was estimated with residual errors of 4.8 mg/cm{sup 3} corresponding to accuracy errors in fat fraction on the order of 5% both for GTP and MF methods. Conclusions: The GTP and MF methods on HR-QCT images permit noninvasive localization and densitometric assessment of marrow fat with residual accuracy errors sufficient to study disorders and therapies known to affect bone marrow composition. Additionally, the methods can be used to correct BMD for fat induced bias. Application and testing in vivo and in longitudinal studies are warranted to determine the clinical performance and value of these methods.« less

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.

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.

Non-destructive X-ray Computed Tomography (XCT) Analysis of Sediment Variance in Marine Cores

NASA Astrophysics Data System (ADS)

Oti, E.; Polyak, L. V.; Dipre, G.; Sawyer, D.; Cook, A.

2015-12-01

Benthic activity within marine sediments can alter the physical properties of the sediment as well as indicate nutrient flux and ocean temperatures. We examine burrowing features in sediment cores from the western Arctic Ocean collected during the 2005 Healy-Oden TransArctic Expedition (HOTRAX) and from the Gulf of Mexico Integrated Ocean Drilling Program (IODP) Expedition 308. While traditional methods for studying bioturbation require physical dissection of the cores, we assess burrowing using an X-ray computed tomography (XCT) scanner. XCT noninvasively images the sediment cores in three dimensions and produces density sensitive images suitable for quantitative analysis. XCT units are recorded as Hounsfield Units (HU), where -999 is air, 0 is water, and 4000-5000 would be a higher density mineral, such as pyrite. We rely on the fundamental assumption that sediments are deposited horizontally, and we analyze the variance over each flat-lying slice. The variance describes the spread of pixel values over a slice. When sediments are reworked, drawing higher and lower density matrix into a layer, the variance increases. Examples of this can be seen in two slices in core 19H-3A from Site U1324 of IODP Expedition 308. The first slice, located 165.6 meters below sea floor consists of relatively undisturbed sediment. Because of this, the majority of the sediment values fall between 1406 and 1497 HU, thus giving the slice a comparatively small variance of 819.7. The second slice, located 166.1 meters below sea floor, features a lower density sediment matrix disturbed by burrow tubes and the inclusion of a high density mineral. As a result, the Hounsfield Units have a larger variance of 1,197.5, which is a result of sediment matrix values that range from 1220 to 1260 HU, the high-density mineral value of 1920 HU and the burrow tubes that range from 1300 to 1410 HU. Analyzing this variance allows us to observe changes in the sediment matrix and more specifically capture where, and to what extent, the burrow tubes deviate from the sediment matrix. Future research will correlate changes in variance due to bioturbation to other features indicating ocean temperatures and nutrient flux, such as foraminifera counts and oxygen isotope data.

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.

Bone mineral density test

MedlinePlus

... density test; Bone densitometry; DEXA scan; DXA; Dual-energy x-ray absorptiometry; p-DEXA; Osteoporosis - BMD ... most common and accurate way uses a dual-energy x-ray absorptiometry (DEXA) scan. DEXA uses low- ...

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.

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.

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

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

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.

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

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.

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.

Equilibrium lithium isotope fractionation in Li-rich minerals

NASA Astrophysics Data System (ADS)

Liu, S.; Li, Y.; Liu, J.

2017-12-01

Lithium is the lightest alkali metal, and only exhibits +1 valence state in minerals. It is widely distributed on the Earth, and usually substitutes for Mg in silicate minerals. Li has two stable isotopes, 6Li and 7Li, with the relative abundances of 7.52% and 92.48%, respectively. The large mass difference between 6Li and 7Li could induce significant isotope fractionation in minerals. Li isotopes can provide an important geochemical tracer for mantle processes. However, the fractionation factors for Li in most minerals remain poorly known, which makes the geochemical implications of Li isotope fractionations in minerals difficult to assess. Here, we try to use the vibrational frequencies obtained by the first-principles methods based on density-functional theory to calculate the Li isotope fractionation parameters for amblygonite (LiAlPO4F), bikitaite (LiSi2AlO7H2), eucryptite (LiAlSiO4), lithiophilite (LiMnPO4), lithiophosphate (Li3PO4), montebrasite (LiAlPO5H), and spodumene (LiAlSi2O6) in the temperature range of 0-1200 ºC. For forsterite (Mg2SiO4) and diopside (CaMgSi2O6) in which Li takes the place of Mg, the equilibrium Li isotope fractionation between them also be studied. Our preliminary calculations show that the coordination number of Li seems to play an important role in controlling Li isotope fractionation in these minerals, and concentration of Li in forsterite and diopside seems to have great effects on Li isotope fractionation factors of them.

Breast-feeding and adherence to infant feeding guidelines do not influence bone mass at age 4 years.

PubMed

Harvey, Nicholas C; Robinson, Sian M; Crozier, Sarah R; Marriott, Lynne D; Gale, Catharine R; Cole, Zoe A; Inskip, Hazel M; Godfrey, Keith M; Cooper, Cyrus

2009-09-01

The impact of variations in current infant feeding practice on bone mineral accrual is not known. We examined the associations between duration of breast-feeding and compliance with infant dietary guidelines and later bone size and density at age 4 years. At total of 599 (318 boys) mother-child pairs were recruited from the Southampton Women's Survey. Duration of breast-feeding was recorded and infant diet was assessed at 6 and 12 months using FFQ. At 6 and 12 months the most important dietary pattern, defined by principal component analysis, was characterised by high consumption of vegetables, fruits and home-prepared foods. As this was consistent with infant feeding recommendations, it was denoted the 'infant guidelines' pattern. At age 4 years, children underwent assessment of whole-body bone size and density using a Hologic Discovery dual-energy X-ray absorptiometry instrument. Correlation methods were used to explore the relationships between infant dietary variables and bone mineral. There was no association between duration of breast-feeding in the first year of life and 4-year bone size or density. 'Infant guidelines' pattern scores at 6 and 12 months were also unrelated to bone mass at age 4 years. We observed wide variations in current infant feeding practice, but these variations were not associated with differences in childhood bone mass at age 4 years.

Bacterial and iron oxide aggregates mediate secondary iron mineral formation: green rust versus magnetite.

PubMed

Zegeye, A; Mustin, C; Jorand, F

2010-06-01

In the presence of methanoate as electron donor, Shewanella putrefaciens, a Gram-negative, facultative anaerobe, is able to transform lepidocrocite (gamma-FeOOH) to secondary Fe (II-III) minerals such as carbonated green rust (GR1) and magnetite. When bacterial cells were added to a gamma-FeOOH suspension, aggregates were produced consisting of both bacteria and gamma-FeOOH particles. Recently, we showed that the production of secondary minerals (GR1 vs. magnetite) was dependent on bacterial cell density and not only on iron reduction rates. Thus, gamma-FeOOH and S. putrefaciens aggregation pattern was suggested as the main mechanism driving mineralization. In this study, lepidocrocite bioreduction experiments, in the presence of anthraquinone disulfonate, were conducted by varying the [cell]/[lepidocrocite] ratio in order to determine whether different types of aggregate are formed, which may facilitate precipitation of GR1 as opposed to magnetite. Confocal laser scanning microscopy was used to analyze the relative cell surface area and lepidocrocite concentration within the aggregates and captured images were characterized by statistical methods for spatial data (i.e. variograms). These results suggest that the [cell]/[lepidocrocite] ratio influenced both the aggregate structure and the nature of the secondary iron mineral formed. Subsequently, a [cell]/[lepidocrocite] ratio above 1 x 10(7) cells mmol(-1) leads to densely packed aggregates and to the formation of GR1. Below this ratio, looser aggregates are formed and magnetite was systematically produced. The data presented in this study bring us closer to a more comprehensive understanding of the parameters governing the formation of minerals in dense bacterial suspensions and suggest that screening mineral-bacteria aggregate structure is critical to understanding (bio)mineralization pathways.

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.

[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).

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...

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.

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.

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.

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.

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.

Current Evidence on the Association of Dietary Patterns and Bone Health: A Scoping Review123

PubMed Central

Movassagh, Elham Z

2017-01-01

Nutrition is an important modifiable factor that affects bone health. Diet is a complex mixture of nutrients and foods that correlate or interact with each other. Dietary pattern approaches take into account contributions from various aspects of diet. Findings from dietary pattern studies could complement those from single-nutrient and food studies on bone health. In this study we aimed to conduct a scoping review of the literature that assessed the impact of dietary patterns (derived with the use of both a priori and data-driven approaches) on bone outcomes, including bone mineral status, bone biomarkers, osteoporosis, and fracture risk. We retrieved 49 human studies up to June 2016 from the PubMed, Embase, and CINAHL databases. Most of these studies used a data-driven method, especially factor analysis, to derive dietary patterns. Several studies examined adherence to a variety of the a priori dietary indexes, including the Mediterranean diet score, the Healthy Eating Index (HEI), and the Alternative Healthy Eating Index (AHEI). The bone mineral density (BMD) diet score was developed to measure adherence to a dietary pattern beneficial to bone mineral density. Findings revealed a beneficial impact of higher adherence to a “healthy” dietary pattern derived using a data-driven method, the Mediterranean diet, HEI, AHEI, Dietary Diversity Score, Diet Quality Index–International, BMD Diet Score, Healthy Diet Indicator, and Korean Diet Score, on bone. In contrast, the “Western” dietary pattern and those featuring some aspects of an unhealthy diet were associated inversely with bone health. In both a priori and data-driven dietary pattern studies, a dietary pattern that emphasized the intake of fruit, vegetables, whole grains, poultry and fish, nuts and legumes, and low-fat dairy products and de-emphasized the intake of soft drinks, fried foods, meat and processed products, sweets and desserts, and refined grains showed a beneficial impact on bone health. Overall, adherence to a healthy dietary pattern consisting of the above-mentioned food groups can improve bone mineral status and decrease osteoporosis and fracture risk. PMID:28096123

Genetic influences on bone loss in the San Antonio Family Osteoporosis Study

PubMed Central

Shaffer, John R.; Kammerer, Candace M.; Bruder, Jan M.; Cole, Shelley A.; Dyer, Thomas D.; Almasy, Laura; MacCluer, Jean W.; Blangero, John; Bauer, Richard L.; Mitchell, Braxton D.

2009-01-01

Summary The genetic contribution to age-related bone loss is not well understood. We estimated that genes accounted for 25–45% of variation in 5-year change in bone mineral density in men and women. An autosome-wide linkage scan yielded no significant evidence for chromosal regions implicated in bone loss. Introduction The contribution of genetics to acquisition of peak bone mass is well documented, but little is know about the influence of genes on subsequent bone loss with age. We therefore measured 5-year change in bone mineral density (BMD) in 300 Mexican Americans (>45 years of age) from the San Antonio Family Osteoporosis Study to identify genetic factors influencing bone loss. Methods Annualized change in BMD was calculated from measurements taken 5.5 years apart. Heritability (h2) of BMD change was estimated using variance components methods and autosome-wide linkage analysis was carried out using 460 microsatellite markers at a mean 7.6 cM interval density. Results Rate of BMD change was heritable at the forearm (h2=0.31, p=0.021), hip (h2 =0.44, p=0.017), spine (h2=0.42, p=0.005), but not whole body (h2=0.18, p=0.123). Covariates associated with rapid bone loss (advanced age, baseline BMD, female sex, low baseline weight, postmenopausal status, and interim weight loss) accounted for 10% to 28% of trait variation. No significant evidence of linkage was observed at any skeletal site. Conclusions This is one of the first studies to report significant heritability of BMD change for weight-bearing and non-weight-bearing bones in an unselected population and the first linkage scan for change in BMD. PMID:18414963

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.

Ore Reserve Estimation of Saprolite Nickel Using Inverse Distance Method in PIT Block 3A Banggai Area Central Sulawesi

NASA Astrophysics Data System (ADS)

Khaidir Noor, Muhammad

2018-03-01

Reserve estimation is one of important work in evaluating a mining project. It is estimation of the quality and quantity of the presence of minerals have economic value. Reserve calculation method plays an important role in determining the efficiency in commercial exploration of a deposit. This study was intended to calculate ore reserves contained in the study area especially Pit Block 3A. Nickel ore reserve was estimated by using detailed exploration data, processing by using Surpac 6.2 by Inverse Distance Weight: Squared Power estimation method. Ore estimation result obtained from 30 drilling data was 76453.5 ton of Saprolite with density of 1.5 ton/m3 and COG (Cut Off Grade) Ni ≥ 1.6 %, while overburden data was 112,570.8 tons with waste rock density of 1.2 ton/m3 . Striping Ratio (SR) was 1.47 : 1 smaller than Stripping Ratio ( SR ) were set of 1.60 : 1.

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.

Correlation between bone mineral density of jaws and skeletal sites in an Iranian population using dual X-ray energy absorptiometry

PubMed Central

Esfahanizadeh, Nasrin; Davaie, Sotoudeh; Rokn, A. R.; Daneshparvar, Hamid Reza; Bayat, Noushin; Khondi, Nasrin; Ajvadi, Sara; Ghandi, Mostafa

2013-01-01

Background: The aim of the present study was to evaluate the relationship between the bone density of various regions of jaws and skeletal bones. Materials and Methods: A total of 110 patients with a mean age of 55.01 ± 10.77 years were selected for the purpose of the present descriptive study. Dual X-ray Energy Absorptiometry (DXA) was carried out to determine bone mineral density (BMD) of the femur and lumbar vertebrae. Then all the subjects underwent DXA of the jaw bones and BMD values were determined at four jaw regions. Data were analyzed by SPSS 16 statistical software, and the correlation between the various BMD values was determined by Pearson's correlation coefficient. Results: The results showed that 42.7% of females had normal BMD values in the femur, and in vertebrae, 20% were osteopenic and 37.3% suffered from osteoporosis, with statistically significant differences in the BMD values of the jaws between the three above-mentioned groups (P < 0.001). There was an increasing tendency toward osteopenia and osteoporosis with age. There was a positive correlation between BMD values of the femur and lumbar vertebrae and those of all the jaw regions under study (P < 0.005). There was a negative correlation (P < 0.01) between age and the BMD values of the femur, lumbar vertebrae and anterior maxilla. Conclusion: The bone density of the maxilla and mandible and presence of osteoporosis or osteopenia in these bones might reflect the same problem in skeletal bones. PMID:24130580

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

Mechanical response tissue analyzer for estimating bone strength

NASA Technical Reports Server (NTRS)

Arnaud, Sara B.; Steele, Charles; Mauriello, Anthony

1991-01-01

One of the major concerns for extended space flight is weakness of the long bones of the legs, composed primarily of cortical bone, that functions to provide mechanical support. The strength of cortical bone is due to its complex structure, described simplistically as cylinders of parallel osteons composed of layers of mineralized collagen. The reduced mechanical stresses during space flight or immobilization of bone on Earth reduces the mineral content, and changes the components of its matrix and structure so that its strength is reduced. Currently, the established clinical measures of bone strength are indirect. The measures are based on determinations of mineral density by means of radiography, photon absorptiometry, and quantitative computer tomography. While the mineral content of bone is essential to its strength, there is growing awareness of the limitations of the measurement as the sole predictor of fracture risk in metabolic bone diseases, especially limitations of the measurement as the sole predictor of fracture risk in metabolic bone diseases, especially osteoporosis. Other experimental methods in clinical trials that more directly evaluate the physical properties of bone, and do not require exposure to radiation, include ultrasound, acoustic emission, and low-frequency mechanical vibration. The last method can be considered a direct measure of the functional capacity of a long bone since it quantifies the mechanical response to a stimulus delivered directly to the bone. A low frequency vibration induces a response (impedance) curve with a minimum at the resonant frequency, that a few investigators use for the evaluation of the bone. An alternative approach, the method under consideration, is to use the response curve as the basis for determination of the bone bending stiffness EI (E is the intrinsic material property and I is the cross-sectional moment of inertia) and mass, fundamental mechanical properties of bone.

Effect of endodontic cement on bone mineral density using serial dual-energy x-ray absorptiometry.

PubMed

Saghiri, Mohammad Ali; Orangi, Jafar; Tanideh, Nader; Janghorban, Kamal; Sheibani, Nader

2014-05-01

Materials with new compositions were tested in order to develop dental materials with better properties. Calcium silicate-based cements, including white mineral trioxide aggregate (WMTA), may improve osteopromotion because of their composition. Nano-modified cements may help researchers produce ideal root-end filling materials. Serial dual-energy x-ray absorptiometry measurement was used to evaluate the effects of particle size and the addition of tricalcium aluminate (C3A) to a type of mineral trioxide aggregate-based cement on bone mineral density and the surrounding tissues in the mandible of rabbits. Forty mature male rabbits (N = 40) were anesthetized, and a bone defect measuring 7 × 1 × 1 mm was created on the semimandible. The rabbits were divided into 2 groups, which were subdivided into 5 subgroups with 4 animals each based on the defect filled by the following: Nano-WMTA (patent application #13/211.880), WMTA (as standard), WMTA without C3A, Nano-WMTA + 2% Nano-C3A (Fujindonjnan Industrial Co, Ltd, Fujindonjnan Xiamen, China), and a control group. Twenty and forty days postoperatively, the animals were sacrificed, and the semimandibles were removed for DXA measurement. The Kruskal-Wallis test followed by the Mann-Whitney U test showed significant differences between the groups at a significance level of P < .05. P values calculated by the Kruskal-Wallis test were .002 for bone mineral density at both intervals and P20 day = .004 and P40 day = .005 for bone mineral content. This study showed that bone regeneration was enhanced by reducing the particle size (nano-modified) and C3A mixture. This may relate to the existence of an external supply of minerals and a larger surface area of nano-modified material, which may lead to faster release rate of Ca(2+), inducing bone formation. Adding Nano-C3A to Nano-WMTA may improve bone regeneration properties. Copyright © 2014 American Association of Endodontists. All rights reserved.

Efficacy of Vitamin K2 for Glucocorticoid-induced Osteoporosis in Patients with Systemic Autoimmune Diseases.

PubMed

Shikano, Kotaro; Kaneko, Kaichi; Kawazoe, Mai; Kaburaki, Makoto; Hasunuma, Tomoko; Kawai, Shinichi

2016-01-01

Objective Vitamin K2 (menatetrenone) is an effective treatment for patients with postmenopausal osteoporosis. We herein performed a subanalysis of patients with systemic autoimmune diseases undergoing glucocorticoid therapy in our previous prospective study. Methods Sixty patients were categorized into a group with vitamin K2 treatment (n=20, Group A) and a group without vitamin K2 treatment (n=40, Group B). All patients were treated with bisphosphonates. Results Serum levels of osteocalcin and undercarboxylated osteocalcin decreased significantly after the start of glucocorticoid therapy in both groups, while the serum osteocalcin level was significantly higher in Group A than Group B during the third (p=0.0250) and fourth weeks (p=0.0155). The serum level of the N-terminal peptide of type I procollagen, a bone formation marker, decreased during glucocorticoid therapy, but was significantly higher in Group A than Group B during the fourth week (p=0.0400). The bone mineral density and fracture rate showed no significant differences between the two groups. Conclusion Although vitamin K2 improves bone turnover markers in patients with osteoporosis on glucocorticoid therapy, it has no significant effect on the bone mineral density and fracture rate after 1.5 years of 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

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.

Cancellous and cortical bone mineral density around an elastic press-fit socket in total hip arthroplasty.

PubMed

Pakvis, Dean F M; Heesterbeek, Petra J C; Severens, Marianne; Spruit, Maarten

2016-12-01

Background and purpose - The acetabular component has remained the weakest link in hip arthroplasty for achievement of long-term survival. One of the possible explanatory factors for acetabular failure has been acetabular stress shielding. For this, we investigated the effects of a cementless elastic socket on acetabular bone mineral density (BMD). Patients and methods - During 2008-2009, we performed a single-center prospective cohort trial on 25 patients (mean age 64 (SD 4), 18 females) in whom we implanted a cementless elastic press-fit socket. Using quantitative BMD measurements on CT, we determined the change in BMD surrounding the acetabular component over a 2-year follow-up period. Results - We found a statistically significant decrease in cancellous BMD (-14% to -35%) and a stable level of cortical BMD (5% to -5%) surrounding the elastic press-fit cup during the follow-up period. The main decrease was seen during the first 6 months after implantation. During the second year, cancellous BMD showed a further decrease in the medial and lower acetabular regions. Interpretation - We found no evidence that an elastic press-fit socket would prevent acetabular stress shielding during a 2-year follow-up.

Treatment feasibility study of osteoporosis using minimal invasive laser needle system

NASA Astrophysics Data System (ADS)

Kang, Dongyeon; Ko, Chang-Yong; Ryu, Yeon-Hang; Park, Sunwook; Kim, Han-Sung; Jung, Byungjo

2010-02-01

Although the mechanism of laser stimulation effect in bone has not completely understood, laser stimulation is recommended in the treatment of osteoporosis due to positive treatment efficacy. In this study, a minimal invasive laser needle system (MILNS) was developed using a fine hollow needle in order to stimulate directly bone site by guiding an optical fiber. In order to evaluate the MILNS as a treatment method, in-vivo animal experiment study was performed using osteopenic mice. Twelve virginal ICR mice were employed and divided two groups: SHAM-group and LASERgroup. SHARM-group was stimulated by only fine hollow needle and LASER-group by fine hollow needle combined with laser stimulation. All mice were served in-vivo micro-CT images before and after treatment. Three dimensional (3D) structural parameters and vBMD (volume bone mineral density, g/cm3) in the trabecular bone were measured. After 2 weeks of stimulation, the vBMD, BV/TV, Tb.Th and Tb.N in LASER-group were significantly higher than those in SHAM-group (p<0.05). Potentially, this study suggested that the MILNS might prevent the bone loss and maintains the bone mineral density of osteopenic mice.

Degradation of clofibric acid in acidic aqueous medium by electro-Fenton and photoelectro-Fenton.

PubMed

Sirés, Ignasi; Arias, Conchita; Cabot, Pere Lluís; Centellas, Francesc; Garrido, José Antonio; Rodríguez, Rosa María; Brillas, Enric

2007-01-01

Acidic aqueous solutions of clofibric acid (2-(4-chlorophenoxy)-2-methylpropionic acid), the bioactive metabolite of various lipid-regulating drugs, have been degraded by indirect electrooxidation methods such as electro-Fenton and photoelectro-Fenton with Fe(2+) as catalyst using an undivided electrolytic cell with a Pt anode and an O(2)-diffusion cathode able to electrogenerate H(2)O(2). At pH 3.0 about 80% of mineralization is achieved with the electro-Fenton method due to the efficient production of oxidant hydroxyl radical from Fenton's reaction between Fe(2+) and H(2)O(2), but stable Fe(3+) complexes are formed. The photoelectro-Fenton method favors the photodecomposition of these species under UVA irradiation, reaching more than 96% of decontamination. The mineralization current efficiency increases with rising metabolite concentration up to saturation and with decreasing current density. The photoelectro-Fenton method is then viable for treating acidic wastewaters containing this pollutant. Comparative degradation by anodic oxidation (without Fe(2+)) yields poor decontamination. Chloride ion is released during all degradation processes. The decay kinetics of clofibric acid always follows a pseudo-first-order reaction, with a similar rate constant in electro-Fenton and photoelectro-Fenton that increases with rising current density, but decreases at greater metabolite concentration. 4-Chlorophenol, 4-chlorocatechol, 4-chlororesorcinol, hydroquinone, p-benzoquinone and 1,2,4-benzenetriol, along with carboxylic acids such as 2-hydroxyisobutyric, tartronic, maleic, fumaric, formic and oxalic, are detected as intermediates. The ultimate product is oxalic acid, which forms very stable Fe(3+)-oxalato complexes under electro-Fenton conditions. These complexes are efficiently photodecarboxylated in photoelectro-Fenton under the action of UVA light.

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

Does Quantitative Tibial Ultrasound Predict Low Bone Mineral Density Defined by Dual Energy X-Ray Absorptiometry?

PubMed Central

Birtane, Murat; Ekuklu, Galip; Cermik, Fikret; Tuna, Filiz; Kokino, Siranus

2008-01-01

Purpose Efforts for the early detection of bone loss and subsequent fracture risk by quantitative ultrasound (QUS), which is a non-invasive, radiation free, and cheaper method, seem rational to reduce the management costs. We aimed in this study to assess the probable correlation of speed of sound (SOS) values obtained by QUS with bone mineral density (BMD) as measured by the gold standard method, dual energy X-ray absorptiometry (DEXA), and to investigate the diagnostic value of QUS to define low BMD. Materials and Methods One hundred twenty-two postmenopausal women having prior standard DEXA measurements were included in the study. Spine and proximal femur (neck, trochanter and Ward's triangle) BMD were assessed in a standard protocol by DEXA. The middle point of the right tibia was chosen for SOS measurement by tibial QUS. Results The SOS values were observed to be significantly higher in the normal BMD (t score > - 1) group at all measurement sites except for the lumbar region, when compared with the low BMD group (t score < - 1). SOS was negatively correlated with age (r = - 0.66) and month since menopause (r = - 0.57). The sensitivity, specificity, and positive and negative predictive values for QUS t score to diagnose low BMD did not seem to be satisfactory at either of the measurement sites. Conclusion Tibial SOS was correlated weakly with BMD values of femur and lumbar spine as measured by DEXA and its diagnostic value did not seem to be high for discriminating between normal and low BMD, at these sites. PMID:18581594

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 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.

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.

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.

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.

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.

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

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.

The Fractal Behavior of Crystal Distribution of la Gloria Pluton, Chile

NASA Astrophysics Data System (ADS)

Gutiérrez, F. J.; Payacán, I. J.; Pasten, D.; Aravena, A.; Gelman, S. E.; Bachmann, O.; Parada, M. A.

2013-12-01

We utilize fractal analysis to study the spatial distributions of crystals in a 10 Ma granitic intrusion (La Gloria pluton) located in the central Chilean Andes. Previous work determined the crystal size distribution (CSD) and anisotropy of magnetic susceptibility (AMS) tensors throughout this pluton. Using orthogonal thin sections oriented along the AMS tensor axes, we have applied fractal analysis in three magmatic crystal families: plagioclase, ferromagnesian minerals (biotite and amphibole), and Fe-Ti oxides (magnetite with minor ilmenite). We find that plagioclase and ferromagnesian minerals have a Semi-logarithmic CSD (S-CSD), given by: log(n/n0)= -L/C (1) where n [mm-4], n0 [mm-4], L [mm] and C [mm] are crystal density, intercept (nucleation density; L=0), size of crystals (three axes) and characteristic length, respectively. In contrast, Fe-Ti oxides have a Fractal CSD (F-CSD, power law size distribution), given by: log(n)= - Dn log(L) + n1 (2) where Dn and n1 [log(mm-4)] are a non-dimensional proportionality constant and the logarithm of the initial crystallization density (n1 = log(n(L=1 mm))), respectively. Finally, we calculate the fractal dimension (D0) by applying the box-counting method on each crystal thin section image, using: log(N) = -D0 log(ɛ) (3) where N and ɛ are the number of boxes occupied by minerals and the length of the square box, respectively. Results indicate that D0 values (eq. 3) are well defined for all minerals, and are higher for plagioclase than for ferromagnesian minerals and lowest for Fe-Ti oxides. D0 values are correlated with n0 and -1/C for S-CSD (eq. 1), and with n1 values for F-CSD (eq. 2). These correlations between fractal dimensions with CSD parameters suggest crystal growth follows a fractal behaviour in magmatic systems. Fractal behaviour of CSD means that the spatial distribution of crystals follows an all-scale pattern as part of a self-organized magmatic system. We interpret S-CSD of plagioclase and ferromagnesian minerals as consequence of early to intermediate crystal growth, whereas F-CSD of magnetite is also a consequence of late magmatic equilibration by increasing of fine magnetite crystals (e.g. reaction of hornblende to magnetite plus actinolite, biotite and titanite). Acknowledgments. This research has been developed by the FONDECYT N°11100241 and PBCT-PDA07 projects granted by CONICYT (Chilean National Commission for Science and Technology). I.P. is supported by CONICYT magister grant N°22130729. F.G. and I.P. thank to FONDAP N°15090013 for supporting during the conference. D.P. acknowledges FONDECYT grant N° 3120237.

Dissociation of water and Acetic acid on PbS from first principles

NASA Astrophysics Data System (ADS)

Satta, Alessandra; Ruggerone, Paolo; de Giudici, Giovanni

2008-03-01

The adsorption of complex molecules at mineral surfaces are crucial ingredients for understanding the mechanisms that rule the interaction between minerals and the biosphere and for predicting both the stability and the reactivity of minerals. The present work focuses mainly on the early stages of different adsorption reactions occurring at both the cleavage surface and a high-index vicinal surface of galena (PbS). We have studied the dissociation mechanism of water and acetic acid on the galena surfaces by means of ab initio calculations within the framework of the density functional theory in the generalized gradient approximation and of pseudopotential approach. The calculated adsorption energies of the molecules indicate the stepped surface as the most reactive, as expected. The free energy surface during the reaction process has been explored via metadynamics[1]. The optimized configurations of both reactants and products obtained, were then used to accurately calculate the dissociation energy via the Nudge Elastic Band method[2]. [1] A. Laio and M. Parrinello, PNAS 99, 12562 (2002). [2] G. Mills and H. Jonsson, Phys. Rev. Lett. 72, 1124 (1994).

Preliminary studies of mineralization during distraction osteogenesis.

PubMed

Aronson, J; Good, B; Stewart, C; Harrison, B; Harp, J

1990-01-01

Distraction osteogenesis by the Ilizarov method was performed on 20 dogs. Mineralization at the site of the left tibial metaphyseal lengthening was measured by weekly quantitative computer tomography (QCT) using the contralateral tibia as a control. Four dogs each were killed on Days 7, 14, 21, and 28 of distraction in order to correlate QCT with microradiology, nondecalcified histology, quantitative calcium analysis, and scanning electron microscopy. It was consistently found that intramembranous ossification proceeded centripetally from each corticotomy surface toward the central fibrous interzone. Bone columns crystallized along longitudinally oriented collagen bundles, expanding circumferentially to surrounding bundles. As the distraction gap increased, the bone columns increased in length and in diameter, while the fibrous interzone remained about 4 mm long. Histologically, the bone columns resembled stalagmites and stalactites, as seen by microradiography and scanning electron microscopy, that projected from each corticotomy surface toward the center. These cones reached maximum diameters of 150-200 mu at the corticotomy surfaces. Radiodensity (QCT) increased gradually from the central fibrous interzone toward each corticotomy surface. Mineral density, as determined by calcium quantification, reflected the microscopic geometry and radiographic polarity.

Effects of ecosystem-based management treatments

Treesearch

Michael G. Harrington; Carl E. Fiedler; Stephen F. Arno; Ward W. McCaughey; Leon J. Theroux; Clinton E. Carlson; Kristin L. Zouhar; Thomas H. DeLuca; Donald J. Bedunah; Dayna M. Ayers; Elizabeth A. Beringer; Sallie J. Hejl; Lynn Bacon; Robert E. Benson; Jane Kapler Smith; Rick Floch

1999-01-01

The prescribed burn treatments were applied to reduce pre-existing and new slash fuel loadings, reduce understory tree density to lower crown fire potential, stimulate vigor of decadent understory vegetation, produce mineral seedbeds for seral species establishment, and increase availability of mineral nutrients. To test the feasibility of prescribed burning under a...

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.

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.

MR-Based Assessment of Bone Marrow Fat in Osteoporosis, Diabetes, and Obesity

PubMed Central

Cordes, Christian; Baum, Thomas; Dieckmeyer, Michael; Ruschke, Stefan; Diefenbach, Maximilian N.; Hauner, Hans; Kirschke, Jan S.; Karampinos, Dimitrios C.

2016-01-01

Bone consists of the mineralized component (i.e., cortex and trabeculae) and the non-mineralized component (i.e., bone marrow). Most of the routine clinical bone imaging uses X-ray-based techniques and focuses on the mineralized component. However, bone marrow adiposity has been also shown to have a strong linkage with bone health. Specifically, multiple previous studies have demonstrated a negative association between bone marrow fat fraction (BMFF) and bone mineral density. Magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) are ideal imaging techniques for non-invasively investigating the properties of bone marrow fat. In the present work, we first review the most important MRI and MRS methods for assessing properties of bone marrow fat, including methodologies for measuring BMFF and bone marrow fatty acid composition parameters. Previous MRI and MRS studies measuring BMFF and fat unsaturation in the context of osteoporosis are then reviewed. Finally, previous studies investigating the relationship between bone marrow fat, other fat depots, and bone health in patients with obesity and type 2 diabetes are presented. In summary, MRI and MRS are powerful non-invasive techniques for measuring properties of bone marrow fat in osteoporosis, obesity, and type 2 diabetes and can assist in future studies investigating the pathophysiology of bone changes in the above clinical scenarios. PMID:27445977

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.

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.

Titanium minerals of placer deposits as a source for new materials

NASA Astrophysics Data System (ADS)

Kotova, Olga; Ponaryadov, Alexey

2015-04-01

Heavy mineral deposits are a source of the economic important element titanium, which is contained in ilmenite and leucoxene. The mineral composition of placer titanium ore and localization pattern of ore minerals determine their processing and enriching technologies. New data on the mineralogy of titanium ores from modern coastal-marine placer in Stradbroke Island, Eastern Australia, and Pizhma paleoplacer in Middle Timan, Russia, and materials on their basis are presented. The samples were studied by the following methods: optical-mineralogical (stereomicroscope MBS-10, polarizing microscope POLAM L-311), semiquantitative x-ray phase analysis (x-ray difractometer X'Pert PRO MPD). Besides microprobe (VEGA 3 TESCAN) and x-ray fluorescent analysis (XRF-1800 Shimadzu) were used. By the mineralogical composition ores of the both deposits are complex: enriched by valuable minerals. Apart from main ore concentrates it is possible to obtain accompanying nonmetallic products. This will increase the efficiency of deposit exploitation. Ilmenite dominates in ore sands of Stradbroke Island, and leucoxene dominates in the ores of the Pizhma titanium deposit. Australian ilmenite and its altered varieties are mainly characterized by a very high MnO content (from 5.24 to 11.08 %). The irregular distribution of iron oxides, titanium and manganese in the altered ilmenite was shown in the paper. E.g., in the areas of substitution of ilmenite by pseudorutile the concentrations of the given elements are greatly various due to various ratios of basic components in each grain. Their ratios are equal in the area of rutile evolution. Moreover, the high content of gold, diamonds and also rare earth elements (REE) and rare metals (their forms are not determined) were studied. We found native copper on the surface of minerals composing titanium-bearing sandstones of the Pizhma placer. According to the technological features of rocks (density and magnetic) studied placers are close. The obtained results of physical studies, mineral composition features, morphostructural characteristics and degree of alteration of titanium minerals from the placers specify a high potential of physical methods of processing (gravitational and magnetic separation, flotation) and possible application of combined methods of processing. Production of pigment titanium dioxide for further production of titanium white, paper, plastics etc is the usual application area of titanium concentrates. Titanium dioxide of high chemical purity is used to produce optically transparent glass, fiber optics, electronics (iPad), piezoceramics, in medical and food industry. We designed photocatalysts based on leucoxene from Pizhma placer. The results showed that the photocatalysts based on rutile, synthesized from leucoxene from Pizhma deposit, can be applied to decay phenols in water.

Low bone mineral mass is associated with decreased bone formation and diet in girls with Rett syndrome.

PubMed

Motil, Kathleen J; Barrish, Judy O; Neul, Jeffrey L; Glaze, Daniel G

2014-09-01

The aim of the present study was to characterize biomarkers of bone turnover and their relation with bone mineral mass in a cross-sectional cohort of girls with Rett syndrome (RTT) and to examine the role of dietary, biochemical, hormonal, and inflammatory factors on bone mineral mass and bone biomarkers in this disorder. Total body bone mineral content (BMC) and bone mineral density (BMD) were determined by dual-energy x-ray absorptiometry. Dietary nutrient intakes were determined from 3-day food records. Biomarkers of bone turnover, bone metabolites, vitamin D metabolites, hormones, and inflammatory markers were measured by standard clinical laboratory methods. Serum osteocalcin, bone alkaline phosphatase, and C-telopeptide showed significant inverse relations with age in the RTT cohort. Mean osteocalcin concentrations were significantly lower and mean bone alkaline phosphatase concentrations were significantly higher for individual age groups in the RTT cohort than mean values for their respective age ranges in the reference population. Significant inverse associations were identified between urinary calcium losses, expressed as calcium:creatinine ratios, and total body BMC and BMD z scores. Dietary protein, calcium, and phosphorus intakes, expressed as a proportion of Dietary Reference Intakes for age and sex, showed significant positive associations with total body BMD z scores. The present study suggests decreased bone formation instead of increased bone resorption may explain in part the deficits in bone mineral mass in RTT and that attention to the adequacy of dietary protein, calcium, and phosphorus intakes may offer an opportunity to improve bone health in RTT.

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

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.

Prediction of risk of fracture in the tibia due to altered bone mineral density distribution resulting from disuse: a finite element study.

PubMed

Gislason, Magnus K; Coupaud, Sylvie; Sasagawa, Keisuke; Tanabe, Yuji; Purcell, Mariel; Allan, David B; Tanner, K Elizabeth

2014-02-01

The disuse-related bone loss that results from immobilisation following injury shares characteristics with osteoporosis in post-menopausal women and the aged, with decreases in bone mineral density leading to weakening of the bone and increased risk of fracture. The aim of this study was to use the finite element method to: (i) calculate the mechanical response of the tibia under mechanical load and (ii) estimate of the risk of fracture; comparing between two groups, an able-bodied group and spinal cord injury patients group suffering from varying degrees of bone loss. The tibiae of eight male subjects with chronic spinal cord injury and those of four able-bodied age-matched controls were scanned using multi-slice peripheral quantitative computed tomography. Images were used to develop full three-dimensional models of the tibiae in Mimics (Materialise) and exported into Abaqus (Simulia) for calculation of stress distribution and fracture risk in response to specified loading conditions - compression, bending and torsion. The percentage of elements that exceeded a calculated value of the ultimate stress provided an estimate of the risk of fracture for each subject, which differed between spinal cord injury subjects and their controls. The differences in bone mineral density distribution along the tibia in different subjects resulted in different regions of the bone being at high risk of fracture under set loading conditions, illustrating the benefit of creating individual material distribution models. A predictive tool can be developed based on these models, to enable clinicians to estimate the amount of loading that can be safely allowed onto the skeletal frame of individual patients who suffer from extensive musculoskeletal degeneration (including spinal cord injury, multiple sclerosis and the ageing population). The ultimate aim is to reduce fracture occurrence in these vulnerable groups.

Laxative use and incident falls, fractures and change in bone mineral density in postmenopausal women: results from the Women’s Health Initiative

PubMed Central

2013-01-01

Background Laxatives are among the most widely used over-the-counter medications in the United States but studies examining their potential hazardous side effects are sparse. Associations between laxative use and risk for fractures and change in bone mineral density [BMD] have not previously been investigated. Methods This prospective analysis included 161,808 postmenopausal women (8907 users and 151,497 nonusers of laxatives) enrolled in the WHI Observational Study and Clinical Trials. Women were recruited from October 1, 1993, to December 31, 1998, at 40 clinical centers in the United States and were eligible if they were 50 to 79 years old and were postmenopausal at the time of enrollment. Medication inventories were obtained during in-person interviews at baseline and at the 3-year follow-up visit on everyone. Data on self-reported falls (≥2), fractures (hip and total fractures) were used. BMD was determined at baseline and year 3 at 3 of the 40 clinical centers of the WHI. Results Age-adjusted rates of hip fractures and total fractures, but not for falls were similar between laxative users and non-users regardless of duration of laxative use. The multivariate-adjusted hazard ratios for any laxative use were 1.06 (95% confidence interval [CI], 1.03-1.10) for falls, 1.02 (95% CI, 0.85-1.22) for hip fractures and 1.01 (95% CI, 0.96-1.07) for total fractures. The BMD levels did not statistically differ between laxative users and nonusers at any skeletal site after 3-years intake. Conclusion These findings support a modest association between laxative use and increase in the risk of falls but not for fractures. Its use did not decrease bone mineral density levels in postmenopausal women. Maintaining physical functioning, and providing adequate treatment of comorbidities that predispose individuals for falls should be considered as first measures to avoid potential negative consequences associated with laxative use. PMID:23635086

Effects of Arsenic on Osteoblast Differentiation in Vitro and on Bone Mineral Density and Microstructure in Rats

PubMed Central

Wu, Cheng-Tien; Lu, Tung-Ying; Chan, Ding-Cheng; Tsai, Keh-Sung; Yang, Rong-Sen

2014-01-01

Background: Arsenic is a ubiquitous toxic element and is known to contaminate drinking water in many countries. Several epidemiological studies have shown that arsenic exposure augments the risk of bone disorders. However, the detailed effect and mechanism of inorganic arsenic on osteoblast differentiation of bone marrow stromal cells and bone loss still remain unclear. Objectives: We investigated the effects and mechanism of arsenic on osteoblast differentiation in vitro and evaluated bone mineral density (BMD) and bone microstructure in rats at doses relevant to human exposure from drinking water. Methods: We used a cell model of rat primary bone marrow stromal cells (BMSCs) and a rat model of long-term exposure with arsenic-contaminated drinking water, and determined bone microstructure and BMD in rats by microcomputed tomography (μCT). Results: We observed significant attenuation of osteoblast differentiation after exposure of BMSCs to arsenic trioxide (0.5 or 1 μM). After arsenic treatment during differentiation, expression of runt-related transcription factor-2 (Runx2), bone morphogenetic protein-2 (BMP-2), and osteocalcin in BMSCs was inhibited and phosphorylation of enhanced extracellular signal-regulated kinase (ERK) was increased. These altered differentiation-related molecules could be reversed by the ERK inhibitor PD98059. Exposure of rats to arsenic trioxide (0.05 or 0.5 ppm) in drinking water for 12 weeks altered BMD and microstructure, decreased Runx2 expression, and increased ERK phosphorylation in bones. In BMSCs isolated from arsenic-treated rats, osteoblast differentiation was inhibited. Conclusions: Our results suggest that arsenic is capable of inhibiting osteoblast differentiation of BMSCs via an ERK-dependent signaling pathway and thus increasing bone loss. Citation: Wu CT, Lu TY, Chan DC, Tsai KS, Yang RS, Liu SH. 2014. Effects of arsenic on osteoblast differentiation in vitro and on bone mineral density and microstructure in rats. Environ Health Perspect 122:559–565; http://dx.doi.org/10.1289/ehp.1307832 PMID:24531206

Ethnic and sex differences in bone marrow adipose tissue and bone mineral density relationship

PubMed Central

Chen, J.; Gantz, M.; Punyanitya, M.; Heymsfield, S. B.; Gallagher, D.; Albu, J.; Engelson, E.; Kotler, D.; Pi-Sunyer, X.; Shapses, S.

2012-01-01

Summary The relationship between bone marrow adipose tissue and bone mineral density is different between African Americans and Caucasians as well as between men and women. This suggests that the mechanisms that regulate the differentiation and proliferation of bone marrow stromal cells may differ in these populations. Introduction It has long been established that there are ethnic and sex differences in bone mineral density (BMD) and fracture risk. Recent studies suggest that bone marrow adipose tissue (BMAT) may play a role in the pathogenesis of osteoporosis. It is unknown whether ethnic and sex differences exist in the relationship between BMAT and BMD. Methods Pelvic BMAT was evaluated in 455 healthy African American and Caucasian men and women (age 18–88 years) using whole-body T1-weighted magnetic resonance imaging. BMD was measured using whole-body dual-energy X-ray absorptiometry. Results A negative correlation was observed between pelvic BMAT and total body BMD or pelvic BMD (r=−0.533, −0.576, respectively; P<0.001). In multiple regression analyses with BMD as the dependent variable, ethnicity significantly entered the regression models as either an individual term or an interaction with BMAT. Menopausal status significantly entered the regression model with total body BMD as the dependent variable. African Americans had higher total body BMD than Caucasians for the same amount of BMAT, and the ethnic difference for pelvic BMD was greater in those participants with a higher BMAT. Men and premeno-pausal women had higher total body BMD levels than postmenopausal women for the same amount of BMAT. Conclusions An inverse relationship exists between BMAT and BMD in African American and Caucasian men and women. The observed ethnic and sex differences between BMAT and BMD in the present study suggest the possibility that the mechanisms regulating the differentiation and proliferation of bone marrow stromal cells may differ in these populations. PMID:22173789

Radiative Transfer of Solar Light in Dense Complex Media : Theoretical and Experimental Achievements by the Planetary Community

NASA Astrophysics Data System (ADS)

Doute, S.; Schmitt, B.

2004-05-01

Visible and near infrared imaging spectroscopy is one of the key techniques to detect, map and characterize mineral and volatile species existing at the surface of the planets. Indeed the chemical composition, granularity, texture, physical state, etc, of the materials determine the existence and morphology of the absorption bands. However the development of quantitative methods to analyze reflectance spectra requires mastering of a very challenging physics: the reflection of solar light by densely packed, absorbent and highly scattering materials that usually present a fantastic structural complexity at different spatial scales. Volume scattering of photons depends on many parameters like the intrinsic optical properties, the shapes, sizes and the packing density of the mineral or icy grains forming the natural media. Their discontinuous and stochastic nature plays a great role especially for reflection and shading by the top few grains of the surface. Over several decades, the planetary community has developed increasingly sophisticated tools to handle this problem of radiative transfer in dense complex media in order to fulfill its needs. Analytical functions with a small number of non physical adjusting parameters were first proposed to reproduce the photometry of the planets and satellites. Then reflectance models were built by implementing methods of radiative transfer in continuously absorbent and scattering medium. A number of very restricting hypothesis forms the basis of these methods, e.g. low particles density, scattering treated in the far field approximation. A majority of these assumptions does not stand when treating planetary regoliths or volatile deposits. In addition, the classical methods completely bypass effects due to the constructive interference of scattered waves for backscattering or specular geometries (e.g. the opposition effect). Different, sometimes competing, approaches have been proposed to overcome some of these limitations. In particular Monte Carlo ray tracing simulations have been recently carried out to investigate properties of particulate media that are traditionally ignored or crudely treated: packing density, micro-roughness, etc. The efforts of the community to address the later problems are not only theoretical but also experimental with the development of several dedicated goniometers.

Increased serum cartilage oligomeric matrix protein levels and decreased patellar bone mineral density in patients with chondromalacia patellae

PubMed Central

Murphy, E; FitzGerald, O; Saxne, T; Bresnihan, B

2002-01-01

Background: Chondromalacia patellae is a potentially disabling disorder characterised by features of patellar cartilage degradation. Objective: To evaluate markers of cartilage and bone turnover in patients with chondromalacia patellae. Methods: 18 patients with chondromalacia patellae were studied. Serum cartilage oligomeric matrix protein (s-COMP) and bone sialoprotein (s-BSP) levels were measured by enzyme linked immunosorbent assay (ELISA) and compared with those of age and sex matched healthy control subjects. Periarticular bone mineral density (BMD) of both knee joints was assessed by dual energy x ray absorptiometry (DXA). Results: s-COMP levels were significantly raised in all patients with chondromalacia patellae compared with healthy control subjects (p=0.0001). s-BSP levels did not differ significantly between the groups (p=0.41). BMD of the patella was significantly reduced in patients with chondromalacia patellae compared with the control subjects (p=0.016). In patients with bilateral chondromalacia patellae, BMD of the patella was lower in the more symptomatic knee joint (p=0.005). Changes in periarticular BMD were localised to the patella and were not present in femoral regions. Neither s-COMP (p=0.18) nor s-BSP (p=0.40) levels correlated with patellar BMD. Conclusions: Increased s-COMP levels, reflecting cartilage degradation, and reduced BMD localised to the patella may represent clinically useful markers in the diagnosis and monitoring of patients with chondromalacia patellae. Measures of cartilage degradation did not correlate with loss of patellar bone density, suggesting dissociated pathophysiological mechanisms. PMID:12379520

Modified Spectral Fatigue Methods for S-N Curves With MIL-HDBK-5J Coefficients

NASA Technical Reports Server (NTRS)

Irvine, Tom; Larsen, Curtis

2016-01-01

The rainflow method is used for counting fatigue cycles from a stress response time history, where the fatigue cycles are stress-reversals. The rainflow method allows the application of Palmgren-Miner's rule in order to assess the fatigue life of a structure subject to complex loading. The fatigue damage may also be calculated from a stress response power spectral density (PSD) using the semi-empirical Dirlik, Single Moment, Zhao-Baker and other spectral methods. These methods effectively assume that the PSD has a corresponding time history which is stationary with a normal distribution. This paper shows how the probability density function for rainflow stress cycles can be extracted from each of the spectral methods. This extraction allows for the application of the MIL-HDBK-5J fatigue coefficients in the cumulative damage summation. A numerical example is given in this paper for the stress response of a beam undergoing random base excitation, where the excitation is applied separately by a time history and by its corresponding PSD. The fatigue calculation is performed in the time domain, as well as in the frequency domain via the modified spectral methods. The result comparison shows that the modified spectral methods give comparable results to the time domain rainflow counting method.

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.

Investigating the Prevalence of Low Bone Mass in Children of Southern Iran and Its Associated Factors

PubMed Central

Saki, Forough; Ranjbar Omrani, Gholamhossein; Jeddi, Marjan; Bakhshaieshkaram, Marzie; Dabbaghmanesh, Mohammad Hossein

2017-01-01

Background Improving peak bone mass and bone strength in the first years of life and enhancing it during young adulthood could prevent osteoporosis and fractures in the last years of life. We evaluated the prevalence of low bone mass in the lumbar and femoral neck and its associated factors in southern Iranian children. Methods This is a cross-sectional study on healthy Iranian children aged 9 - 18 years old during 2011 - 2012. Dual energy X-ray absorptiometry (DEXA) was used for measuring bone mineral density (BMD). BMD Z-score ≤ -2 was considered as low. Anthropometric data, physical activity, sun exposure, puberty, and mineral biochemical parameters were assessed. Data were analyzed using SPSS v.15. Results 477 normal children, including 236 (49.5%) girls and 241 (50.5%) boys, aged 13.8 ± 2.7 years were enrolled. Prevalence of low bone mass (LBM) in the femoral and lumbar region was 10.7% and 18.7%, respectively. The prevalence of LBM in femur of girls is twice more than boys. Fat mass index, BMI Z-score, and physical activity were associated with lumbar low bone mass. BMI Z-score and physical activity were associated with femoral low bone mass. Conclusions High prevalence of low bone mineral density in children 9 to 18 years in south of the country is concerned and is needed to plan for prevention and treatment. BMI-Z score, fat mass index, and physical activity were the 3 most important preventive factors in developing low bone mass in children. PMID:29344033

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....

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.

Bone mineral density and mammographic density in Mexican women

PubMed Central

Moseson, Heidi; Rice, Megan S.; López-Ridaura, Ruy; Bertrand, Kimberly A.; Torres, Gabriela; Blanco, Margarita; Tamayo-Orozco, Juan Alfredo; Lajous, Martin; Romieu, Isabelle

2016-01-01

Background Bone mineral density (BMD) is a putative marker for lifetime exposure to estrogen. Studies that have explored whether BMD is a determinant of mammographic density (MD) have observed inconsistent results. Therefore, we examined this potential association in a sample of women (N=1,516) from the clinical sub-cohort in the Mexican Teachers’ Cohort (N=115,315). Methods We used multivariable linear regression to assess the association between quartiles of BMD and percent MD, as well as total dense and non-dense area of the breast, stratified by menopausal status. We also examined the associations by body mass index (BMI) (<30kg/m2,, ≥30kg/m2). Results Overall, there was no association between BMD and MD among premenopausal women. However, when we stratified by BMI, there was a modest inverse association between BMD and percent MD (difference between extreme quartiles= −2.8, 95%CI: −5.9, 0.27, p-trend=0.04) among women with BMI <30 kg/m2, but a positive association among obese women (comparable difference=5.1, 95%CI: 0.02, 10.1, p-trend=0.03; p-interaction<0.01). Among postmenopausal women, BMD and percent MD were positively associated after adjustment for BMI (p-trend<0.01). Postmenopausal women in the highest two quartiles of BMD had 4–5 percentage point higher percent MD compared to women in the lowest quartile. The association did not differ by BMI in postmenopausal women (p-interaction=0.76). Conclusion Among obese premenopausal women as well as postmenopausal women, BMD was positively associated with percent MD. Among leaner premenopausal women, BMD and percent MD were modestly inversely associated. These findings support the hypothesis that cumulative exposure to estrogen (as measured by BMD) may influence MD. PMID:26463740

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.

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.

Improvement of calcium mineral separation contrast using anionic reagents: electrokinetics properties and flotation

NASA Astrophysics Data System (ADS)

Lafhaj, Z.; Filippov, L. O.; Filippova, I. V.

2017-07-01

The flotation separation of salt type calcium minerals is problematic, due to the similarities in their same active Ca2+ related site for interaction with anionic collectors and similar physicochemical characteristics such as solubility, zero-point charge, surface speciation and Ca-site density. The work was performed to achieve effective and selective separation of the calcium-minerals using pure minerals samples: orange calcite with Mg impurities, optic calcite with impurities level and an apatite. The pure samples surface was examined using techniques sensitive near-surface like infrared spectroscopy (FTIR) and chemical composition was obtained by ICPMS. The isoelectric point (IEP) and point of zero charge (PZC) in electrolyte were recorded using electrophoresis method at different ionic strengths of the solution. Mechanisms of charge development at the mineral-water interface are discussed. The time of contact as important parameter for the charge equilibrium was deduced from kinetics study and fixed to 30 minutes. The difference in the values obtained between IEP and PZSE can be explained by the presence of a specific adsorption of cations and anions on the surface. The effect of pure anionic collectors such as oleic and linoleic acid were studied. At low pH, both collectors lead to a good recovery for the calcites. The flotation recovery of optic calcite at pH 9 with sodium oleate is higher than with sodium linoleate. At alkaline pH, apatite showed a better recovery with sodium linoleate.

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.

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 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.

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.

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.

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.

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

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.

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.

30 CFR 219.102 - Method of payment.

Code of Federal Regulations, 2010 CFR

2010-07-01

... writing to the Minerals Management Service, Minerals Revenue Management, P.O. Box 5760, Denver, Colorado... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Method of payment. 219.102 Section 219.102 Mineral Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT OF THE INTERIOR MINERALS REVENUE MANAGEMENT...

Ab initio thermodynamic model for magnesium carbonates and hydrates.

PubMed

Chaka, Anne M; Felmy, Andrew R

2014-09-04

An ab initio thermodynamic framework for predicting properties of hydrated magnesium carbonate minerals has been developed using density-functional theory linked to macroscopic thermodynamics through the experimental chemical potentials for MgO, water, and CO2. Including semiempirical dispersion via the Grimme method and small corrections to the generalized gradient approximation of Perdew, Burke, and Ernzerhof for the heat of formation yields a model with quantitative agreement for the benchmark minerals brucite, magnesite, nesquehonite, and hydromagnesite. The model shows how small differences in experimental conditions determine whether nesquehonite, hydromagnesite, or magnesite is the result of laboratory synthesis from carbonation of brucite, and what transformations are expected to occur on geological time scales. Because of the reliance on parameter-free first-principles methods, the model is reliably extensible to experimental conditions not readily accessible to experiment and to any mineral composition for which the structure is known or can be hypothesized, including structures containing defects, substitutions, or transitional structures during solid state transformations induced by temperature changes or processes such as water, CO2, or O2 diffusion. Demonstrated applications of the ab initio thermodynamic framework include an independent means to evaluate differences in thermodynamic data for lansfordite, predicting the properties of Mg analogues of Ca-based hydrated carbonates monohydrocalcite and ikaite, which have not been observed in nature, and an estimation of the thermodynamics of barringtonite from the stoichiometry and a single experimental observation.

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.

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.

Photothermal tomography for the functional and structural evaluation, and early mineral loss monitoring in bones.

PubMed

Kaiplavil, Sreekumar; Mandelis, Andreas; Wang, Xueding; Feng, Ting

2014-08-01

Salient features of a new non-ionizing bone diagnostics technique, truncated-correlation photothermal coherence tomography (TC-PCT), exhibiting optical-grade contrast and capable of resolving the trabecular network in three dimensions through the cortical region with and without a soft-tissue overlayer are presented. The absolute nature and early demineralization-detection capability of a marker called thermal wave occupation index, estimated using the proposed modality, have been established. Selective imaging of regions of a specific mineral density range has been demonstrated in a mouse femur. The method is maximum-permissible-exposure compatible. In a matrix of bone and soft-tissue a depth range of ~3.8 mm has been achieved, which can be increased through instrumental and modulation waveform optimization. Furthermore, photoacoustic microscopy, a comparable modality with TC-PCT, has been used to resolve the trabecular structure and for comparison with the photothermal tomography.

Photothermal tomography for the functional and structural evaluation, and early mineral loss monitoring in bones

PubMed Central

Kaiplavil, Sreekumar; Mandelis, Andreas; Wang, Xueding; Feng, Ting

2014-01-01

Salient features of a new non-ionizing bone diagnostics technique, truncated-correlation photothermal coherence tomography (TC-PCT), exhibiting optical-grade contrast and capable of resolving the trabecular network in three dimensions through the cortical region with and without a soft-tissue overlayer are presented. The absolute nature and early demineralization-detection capability of a marker called thermal wave occupation index, estimated using the proposed modality, have been established. Selective imaging of regions of a specific mineral density range has been demonstrated in a mouse femur. The method is maximum-permissible-exposure compatible. In a matrix of bone and soft-tissue a depth range of ~3.8 mm has been achieved, which can be increased through instrumental and modulation waveform optimization. Furthermore, photoacoustic microscopy, a comparable modality with TC-PCT, has been used to resolve the trabecular structure and for comparison with the photothermal tomography. PMID:25136480

Resolving neutrino mass hierarchy from supernova (anti)neutrino-nucleus reactions

NASA Astrophysics Data System (ADS)

Vale, Deni; Paar, Nils

2015-10-01

Recently a hybrid method has been introduced to determine neutrino mass hierarchy by simultaneous measurements of detector responses induced by antineutrino and neutrino fluxes from accretion and cooling phase of type II supernova. The (anti)neutrino-nucleus cross sections for 12C, 16O, 56Fe and 208Pb are calculated in the framework of relativistic nuclear energy density functional and weak interaction Hamiltonian, while the cross sections for inelastic scattering on free protons in mineral oil and water, p (v¯e,e+)n are obtained using heavy-baryon chiral perturbation theory. The simulations of (anti)neutrino fluxes emitted from a proto-neutron star in a core-collapse supernova include collective and Mikheyev-Smirnov-Wolfenstein effects inside star. It is shown that simultaneous use of ve/v¯e detectors with different target material allow to determine the neutrino mass hierarchy from the ratios of ve/v¯e induced particle emissions. The hybrid method favors detectors with heavier target nuclei (208Pb) for the neutrino sector, while for antineutrinos the use of free protons in mineral oil and water is more appropriate.

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.

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.

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.

Integrated analysis of DNA-methylation and gene expression using high-dimensional penalized regression: a cohort study on bone mineral density in postmenopausal women.

PubMed

Lien, Tonje G; Borgan, Ørnulf; Reppe, Sjur; Gautvik, Kaare; Glad, Ingrid Kristine

2018-03-07

Using high-dimensional penalized regression we studied genome-wide DNA-methylation in bone biopsies of 80 postmenopausal women in relation to their bone mineral density (BMD). The women showed BMD varying from severely osteoporotic to normal. Global gene expression data from the same individuals was available, and since DNA-methylation often affects gene expression, the overall aim of this paper was to include both of these omics data sets into an integrated analysis. The classical penalized regression uses one penalty, but we incorporated individual penalties for each of the DNA-methylation sites. These individual penalties were guided by the strength of association between DNA-methylations and gene transcript levels. DNA-methylations that were highly associated to one or more transcripts got lower penalties and were therefore favored compared to DNA-methylations showing less association to expression. Because of the complex pathways and interactions among genes, we investigated both the association between DNA-methylations and their corresponding cis gene, as well as the association between DNA-methylations and trans-located genes. Two integrating penalized methods were used: first, an adaptive group-regularized ridge regression, and secondly, variable selection was performed through a modified version of the weighted lasso. When information from gene expressions was integrated, predictive performance was considerably improved, in terms of predictive mean square error, compared to classical penalized regression without data integration. We found a 14.7% improvement in the ridge regression case and a 17% improvement for the lasso case. Our version of the weighted lasso with data integration found a list of 22 interesting methylation sites. Several corresponded to genes that are known to be important in bone formation. Using BMD as response and these 22 methylation sites as covariates, least square regression analyses resulted in R 2 =0.726, comparable to an average R 2 =0.438 for 10000 randomly selected groups of DNA-methylations with group size 22. Two recent types of penalized regression methods were adapted to integrate DNA-methylation and their association to gene expression in the analysis of bone mineral density. In both cases predictions clearly benefit from including the additional information on gene expressions.

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.

Low RMRratio as a Surrogate Marker for Energy Deficiency, the Choice of Predictive Equation Vital for Correctly Identifying Male and Female Ballet Dancers at Risk.

PubMed

Staal, Sarah; Sjödin, Anders; Fahrenholtz, Ida; Bonnesen, Karen; Melin, Anna Katarina

2018-06-22

Ballet dancers are reported to have an increased risk for energy deficiency with or without disordered eating behavior. A low ratio between measured ( m ) and predicted ( p ) resting metabolic rate (RMR ratio  < 0.90) is a recognized surrogate marker for energy deficiency. We aimed to evaluate the prevalence of suppressed RMR using different methods to calculate p RMR and to explore associations with additional markers of energy deficiency. Female (n = 20) and male (n = 20) professional ballet dancers, 19-35 years of age, were enrolled. m RMR was assessed by respiratory calorimetry (ventilated open hood). p RMR was determined using the Cunningham and Harris-Benedict equations, and different tissue compartments derived from whole-body dual-energy X-ray absorptiometry assessment. The protocol further included assessment of body composition and bone mineral density, blood pressure, disordered eating (Eating Disorder Inventory-3), and for females, the Low Energy Availability in Females Questionnaire. The prevalence of suppressed RMR was generally high but also clearly dependent on the method used to calculate p RMR, ranging from 25% to 80% in males and 35% to 100% in females. Five percent had low bone mineral density, whereas 10% had disordered eating and 25% had hypotension. Forty percent of females had elevated Low Energy Availability in Females Questionnaire score and 50% were underweight. Suppressed RMR was associated with elevated Low Energy Availability in Females Questionnaire score in females and with higher training volume in males. In conclusion, professional ballet dancers are at risk for energy deficiency. The number of identified dancers at risk varies greatly depending on the method used to predict RMR when using RMR ratio as a marker for energy deficiency.

A Novel Two-Compartment Model for Calculating Bone Volume Fractions and Bone Mineral Densities From Computed Tomography Images.

PubMed

Lin, Hsin-Hon; Peng, Shin-Lei; Wu, Jay; Shih, Tian-Yu; Chuang, Keh-Shih; Shih, Cheng-Ting

2017-05-01

Osteoporosis is a disease characterized by a degradation of bone structures. Various methods have been developed to diagnose osteoporosis by measuring bone mineral density (BMD) of patients. However, BMDs from these methods were not equivalent and were incomparable. In addition, partial volume effect introduces errors in estimating bone volume from computed tomography (CT) images using image segmentation. In this study, a two-compartment model (TCM) was proposed to calculate bone volume fraction (BV/TV) and BMD from CT images. The TCM considers bones to be composed of two sub-materials. Various equivalent BV/TV and BMD can be calculated by applying corresponding sub-material pairs in the TCM. In contrast to image segmentation, the TCM prevented the influence of the partial volume effect by calculating the volume percentage of sub-material in each image voxel. Validations of the TCM were performed using bone-equivalent uniform phantoms, a 3D-printed trabecular-structural phantom, a temporal bone flap, and abdominal CT images. By using the TCM, the calculated BV/TVs of the uniform phantoms were within percent errors of ±2%; the percent errors of the structural volumes with various CT slice thickness were below 9%; the volume of the temporal bone flap was close to that from micro-CT images with a percent error of 4.1%. No significant difference (p >0.01) was found between the areal BMD of lumbar vertebrae calculated using the TCM and measured using dual-energy X-ray absorptiometry. In conclusion, the proposed TCM could be applied to diagnose osteoporosis, while providing a basis for comparing various measurement methods.

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.

Targeted Investigation of Base Metal Mineralization beneath Glacial Cover using Magnetic Field Methods, Petrophysics, and Petrology

NASA Astrophysics Data System (ADS)

Veglio, E.; Ugalde, H. A.; Lenauer, I.; Milkereit, B.

2017-12-01

Magnetic anomalies near areas of known base metal sulphide mineralization were seen in regional airborne data from the Bay of Chaleur in northern New Brunswick, Canada. A ground magnetic investigation was performed over this area to better characterize the source of these regional anomalies and to investigate their relation to the sulphide mineralization. The mineralization is hosted in Late Silurian to Early Devonian volcano-sedimentary stratigraphy and has been identified in several boreholes. This volcano-sedimentary stratigraphy was deposited in a half-graben shallow marine setting, where hydrothermal fluids transported sulphide mineralization through a fault network. The ground magnetic surveys show that two anomalous regions characterized by a total magnetic field of 54,100 nT and 55,500 nT, whereas the shallow alteration associated with mineralized zones are approximately 53,450 nT. These are significant magnetic anomalies are close to 700 nT and 2,000 nT greater than the surrounding area. In order to compare the ground data to the existing airborne, the ground magnetic data was upward continued to a height of 100 meters. The few occurrences of bedrock outcrops on the property confirm the occurrence of rhyolites and tuffs, as well as the presence of sulphide mineralization. However, much of the study area is densely vegetated and covered by glacial sediments of up to 25 meters thickness. Thus, to better interpret the geology and occurrence of the sulphide mineralization, several boreholes were examined on the basis of magnetic susceptibility and further correlated with the borehole logs and observations of lithologies in core. It was found that an individual mafic unit has several orders of magnitude higher magnetic susceptibility than the alteration zones and felsic tuffs where mineralization occurs. This indicates that the magnetic anomaly identified both in the regional magnetic survey and the ground survey is likely caused by the occurrence of this mafic unit. Petrographic analysis of this unit indicates it is a diabase dyke. Further characterization of the host rocks of the sulphide mineralization and the alteration will be accomplished by incorporating historic petrophysical studies of density and conductivity to complement the existing magnetic susceptibility measurements.

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.

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-

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.

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.

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...

Field device to measure viscosity, density, and other slurry properties in drilled shafts [summary].

DOT National Transportation Integrated Search

2016-08-01

Proper performance of the mineral slurries used to stabilize drilled shaft excavations is : maintained by assuring that the density, viscosity, pH, and sand content of the slurry stay : within limits set by the Florida Department of Transportation (F...

Response of Soil Bulk Density and Mineral Nitrogen to Harvesting and Cultural Treatments

Treesearch

Minyi Zhou; Mason C. Carter; Thomas J. Dean

1998-01-01

The interactive effects of harvest intensity, site preparation, and fertilization on soil compaction and nitrogen mineralization were examined in a loblolly pine (Pinus taeda L.) stand growing on a sandy, well-drained soil in eastern Texas. The experimental design was 2 by 2 by 2 factorial, consisting of two harvesting treatments (mechanical whole-...

Hydrologic and water quality effects of thinning Loblolly Pine

Treesearch

Johnny M. Grace; R. W. Skaggs; G. M. Chescheir

2006-01-01

Forest operations such as harvesting, thinning, and site preparation can affect the hydrologic behavior of watersheds on poorly drained soils. The influence of these operations conducted on organic soil sites can be more pronounced than on mineral soil sites due to the differences in bulk density and soil moisture relationships that exist between mineral and organic...

Breastfeeding and maternal health outcomes: a systematic review and meta-analysis

PubMed Central

Chowdhury, Ranadip; Sinha, Bireshwar; Sankar, Mari Jeeva; Taneja, Sunita; Bhandari, Nita; Rollins, Nigel; Bahl, Rajiv; Martines, Jose

2015-01-01

Aim To evaluate the effect of breastfeeding on long-term (breast carcinoma, ovarian carcinoma, osteoporosis and type 2 diabetes mellitus) and short-term (lactational amenorrhoea, postpartum depression, postpartum weight change) maternal health outcomes. Methods A systematic literature search was conducted in PubMed, Cochrane Library and CABI databases. Outcome estimates of odds ratios or relative risks or standardised mean differences were pooled. In cases of heterogeneity, subgroup analysis and meta-regression were explored. Results Breastfeeding >12 months was associated with reduced risk of breast and ovarian carcinoma by 26% and 37%, respectively. No conclusive evidence of an association between breastfeeding and bone mineral density was found. Breastfeeding was associated with 32% lower risk of type 2 diabetes. Exclusive breastfeeding and predominant breastfeeding were associated with longer duration of amenorrhoea. Shorter duration of breastfeeding was associated with higher risk of postpartum depression. Evidence suggesting an association of breastfeeding with postpartum weight change was lacking. Conclusion This review supports the hypothesis that breastfeeding is protective against breast and ovarian carcinoma, and exclusive breastfeeding and predominant breastfeeding increase the duration of lactational amenorrhoea. There is evidence that breastfeeding reduces the risk of type 2 diabetes. However, an association between breastfeeding and bone mineral density or maternal depression or postpartum weight change was not evident. PMID:26172878

Association of Body Weight and Body Mass Index with Bone Mineral Density in Women and Men from Kosovo

PubMed Central

Rexhepi, Sylejman; Bahtiri, Elton; Rexhepi, Mjellma; Sahatciu-Meka, Vjollca; Rexhepi, Blerta

2015-01-01

Background and objective: Body weight and body mass index (BMI) are considered potentially modifiable determinants of bone mass. Therefore, the aim of this study was to explore the association between body weight and body mass index (BMI) with total hip and lumbar spine bone mineral density (BMD). Methods: This cross-sectional study included a population of 100 women and 32 men from Kosovo into three BMI groups. All the study subjects underwent dual-energy X-ray absorptiometry (DXA) measurements. Results: Total hip BMD levels of obese menopausal and premenopausal women and men were significantly higher compared to overweight or normal weight subjects, while lumbar spine BMD levels of only menopausal women and men were higher among obese subjects. Age-adjusted linear regression analysis showed that BMI is a significant independent associate of lumbar spine and total hip BMD in menopausal women and men. Conclusion: Despite positive association between BMI and lumbar spine and total hip BMD in menopausal women, presence of more obese and osteoporotic subjects among menopausal women represent a population at risk for fractures because of poor balance and frequent falls; therefore, both obesity and osteoporosis prevention efforts should begin early on in life. PMID:26543419

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

Risk Factors for Low Bone Mineral Density in Institutionalized Individuals with Developmental Disabilities

PubMed Central

Vice, Michael A.; Nahar, Vinayak K.; Ford, M. Allison; Bass, Martha A.; Johnson, Andrea K.; Davis, Ashton B.; Biviji-Sharma, Rizwana

2015-01-01

Background: Persons with intellectual/developmental disabilities (IDD) are exposed to several factors, which have been determined as risks for osteoporosis. Many of these individuals are non-ambulatory, resulting in lack of weight bearing activity, which is well established as a major contributor to bone loss. The purpose of this study was to investigate risk factors for low bone mineral density (BMD) in persons with IDD residing in residential facilities. Methods: This cross-sectional study was conducted at an Intermediate Care Facility for individuals with Intellectual and Developmental Disabilities (ICF/IDD). Medical records data were used from 69 individuals, including heal scan T-scores, nutritional, pharmacologic and other risk factors. Chi-Square analysis was used to determine relationships between the variables. Results: BMD measures were not significantly associated with age, gender, height, weight, or BMI for this population (P > 0.05). The association between BMD diagnoses and DSM-IV classification of mental retardation approached significance (P = 0.063). A significant association was found with anti-seizure medication (P = 0.009). Conclusion: Follow-up studies should focus on how supplementation and medication changes may or may not alter BMD. Persons with IDD are experiencing longer life expectancies, and therefore, studies ascertaining information on diseases associated with this aging population are warranted. PMID:26290830

Fall-related self-efficacy, not balance and mobility performance, is related to accidental falls in chronic stroke survivors with low bone mineral density

PubMed Central

Pang, Marco Y.C.; Eng, Janice J.

2011-01-01

Introduction Chronic stroke survivors with low bone mineral density (BMD) are particularly prone to fragility fractures. The purpose of this study was to identify the determinants of balance, mobility and falls in this sub-group of stroke patients. Methods Thirty nine chronic stroke survivors with low hip BMD (T-score <-1.0) were studied. Each subject was evaluated for: balance, mobility, leg muscle strength, spasticity, and falls-related self-efficacy. Any falls in the past 12 months were also recorded. Multiple regression analysis was used to identify the determinants of balance and mobility performance whereas logistic regression was used to identify the determinants of falls. Results Multiple regression analysis revealed that after adjusting for basic demographics, falls-related self-efficacy remained independently associated with balance/mobility performance (R2=0.494, P<0.001). Logistic regression showed that falls-related self-efficacy, but not balance and mobility performance, was a significant determinant of falls (odds ratio: 0.18, P=0.04). Conclusions Falls-related self-efficacy, but not mobility and balance performance, was the most important determinant of accidental falls. This psychological factor should not be overlooked in the prevention of fragility fractures among chronic stroke survivors with low hip BMD. PMID:18097709