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Sample records for bone turnover part

  1. Biochemical markers of bone turnover

    International Nuclear Information System (INIS)

    Biochemical markers of bone turnover has received increasing attention over the past few years, because of the need for sensitivity and specific tool in the clinical investigation of osteoporosis. Bone markers should be unique to bone, reflect changes of bone less, and should be correlated with radiocalcium kinetics, histomorphometry, or changes in bone mass. The markers also should be useful in monitoring treatment efficacy. Although no bone marker has been established to meet all these criteria, currently osteocalcin and pyridinium crosslinks are the most efficient markers to assess the level of bone turnover in the menopausal and senile osteoporosis. Recently, N-terminal telopeptide (NTX), C-terminal telopeptide (CTX) and bone specific alkaline phosphatase are considered as new valid markers of bone turnover. Recent data suggest that CTX and free deoxypyridinoline could predict the subsequent risk of hip fracture of elderly women. Treatment of postmenopausal women with estrogen, calcitonin and bisphosphonates demonstrated rapid decrease of the levels of bone markers that correlated with the long-term increase of bone mass. Factors such as circadian rhythms, diet, age, sex, bone mass and renal function affect the results of biochemical markers and should be appropriately adjusted whenever possible. Each biochemical markers of bone turnover may have its own specific advantages and limitations. Recent advances in research will provide more sensitive and specific assays

  2. Normal Bone Turnover in Transient Hyperphosphatasemia

    Science.gov (United States)

    Kutilek, Stepan; Cervickova, Barbora; Bebova, Pavla; Kmonickova, Marie; Nemec, Vladimir

    2012-01-01

    Transient hyperphosphatasemia of infancy and early childhood (THI) is characterized by a temporary isolated elevation of serum alkaline phosphatase activity (ALP), predominantly its bone or liver isoform, in either sick or healthy children under 5 years of age. Return to normal ALP levels usually occurs within four months. Spontaneous rise of ALP might concern the physician, especially when treating seriously ill children. However, THI is considered a benign biochemical disorder with no clinical consequences. Some existing reports support the hypothesis that THI is a result of increased bone turnover. We present evidence of normal bone turnover in two children with THI. In a one-year-old girl and a boy of the same age, high ALP levels (31 and 109 μkat/L, respectively) were accidentally detected. The children had no signs of metabolic bone disease or of liver disease. The high ALP levels returned to normal in two months, thus fulfilling the diagnosis of THI. In both patients, serum parathyroid hormone and bone turnover markers, serum CrossLaps, and serum osteocalcin were neither elevated, nor did these markers follow the ALP dynamics, thus reflecting normal bone turnover in THI. Children with THI should be spared from extensive investigations and unnecessary vitamin D treatment. Conflict of interest:None declared. PMID:22664360

  3. High bone turnover in Irish professional jockeys.

    LENUS (Irish Health Repository)

    Waldron-Lynch, F

    2012-02-01

    SUMMARY: Professional jockeys are routinely exposed to high impact trauma and sustain fractures frequently. We found that jockeys restrict their caloric intake in order to maintain regulation weights, and that bone turnover is high. There are significant health and safety implications for the racing industry. INTRODUCTION: Professional jockeys routinely sustain fractures from high impact falls. Jockeys maintain a low percentage body fat and a low body mass index (BMI) to achieve low weight targets in order to race. We evaluated dietary habits and bone metabolism in jockeys. METHODS: Bone mineral density (BMD) was measured in 27 male jockeys of the 144 jockeys licensed in Ireland. Fourteen (52%) had BMD T score below -1.0, of whom 12 consented to clinical review, nutritional survey, endocrine studies, and bone turnover markers (BTM). BTM were compared to age- and sex-matched controls (n = 16). RESULTS: BMI was 20.6 +\\/- 1.7 kg\\/m(2); previous fracture frequency was 3.2 +\\/- 2.0 per rider. All had normal endocrine axes. The jockeys\\' diet as determined by a 7-day dietary recall was deficient in energy, calcium, and vitamin D intake. Compared with the control group, the jockey group had evidence of increased bone turnover. CONCLUSIONS: A substantial proportion of the professional jockeys in Ireland have low-normal BMD, low BMI, and high bone turnover that may result from weight and dietary restrictions. These factors seem to have a deleterious effect on their bone health and predispose the jockeys to a high fracture risk that should be remediated.

  4. Bone mass and turnover in fibromyalgia

    DEFF Research Database (Denmark)

    Jacobsen, Søren; Gam, A; Egsmose, C;

    1993-01-01

    Physical inactivity accelerates bone loss. Since patients with fibromyalgia are relatively physically inactive, bone mass and markers of bone metabolism were determined in 12 premenopausal women with fibromyalgia and in healthy age matched female control subjects. No differences were found...... in lumbar bone mineral density, femoral neck bone mineral density, serum levels of alkaline phosphatase, osteocalcin, ionized calcium and phosphate. The urinary excretion of both hydroxyproline and calcium relative to urinary creatinine excretion was significantly higher in patients with fibromyalgia, p = 0.......01. This was linked to lower urinary creatinine excretion (p = 0.02) probably reflecting lower physical activity in the patients with fibromyalgia. We conclude that bone mass and turnover are generally not affected in premenopausal women with fibromyalgia....

  5. Estrogen regulates the rate of bone turnover but bone balance in ovariectomized rats is modulated by prevailing mechanical strain

    Science.gov (United States)

    Westerlind, K. C.; Wronski, T. J.; Ritman, E. L.; Luo, Z. P.; An, K. N.; Bell, N. H.; Turner, R. T.

    1997-01-01

    Estrogen deficiency induced bone loss is associated with increased bone turnover in rats and humans. The respective roles of increased bone turnover and altered balance between bone formation and bone resorption in mediating estrogen deficiency-induced cancellous bone loss was investigated in ovariectomized rats. Ovariectomy resulted in increased bone turnover in the distal femur. However, cancellous bone was preferentially lost in the metaphysis, a site that normally experiences low strain energy. No bone loss was observed in the epiphysis, a site experiencing higher strain energy. The role of mechanical strain in maintaining bone balance was investigated by altering the strain history. Mechanical strain was increased and decreased in long bones of ovariectomized rats by treadmill exercise and functional unloading, respectively. Functional unloading was achieved during orbital spaceflight and following unilateral sciatic neurotomy. Increasing mechanical loading reduced bone loss in the metaphysis. In contrast, decreasing loading accentuated bone loss in the metaphysis and resulted in bone loss in the epiphysis. Finally, administration of estrogen to ovariectomized rats reduced bone loss in the unloaded and prevented loss in the loaded limb following unilateral sciatic neurotomy in part by reducing indices of bone turnover. These results suggest that estrogen regulates the rate of bone turnover, but the overall balance between bone formation and bone resorption is influenced by prevailing levels of mechanical strain.

  6. Osteocalcin: an emerging biomarker for bone turnover

    Directory of Open Access Journals (Sweden)

    Brijesh Rathore

    2016-09-01

    Full Text Available Osteocalcin (OC is produced by osteoblasts during bone formation. OC is excreted into urine by glomerular filtration and can be found as fragments in urine. The presence of three vitamin K-dependent and #947;-carboxyglutamic acid residues is critical for osteocalcin's structure, which appears to regulate the maturation of bone mineral. Recent bone biology research have highlighted the importance of bone not only as a structural scaffold to support the human body, but also as a regulator of a metabolic processes that are independent of mineral metabolism. Circulating osteocalcin is present either as carboxylated or as undercarboxylated forms. Increased serum level of osteocalcin is linked with increased bone mineral density. The importance of the bone and ndash;kidney relation in physiologic regulation of mineral ion has also been extensively studied and documented. Several workers have uncovered the role of insulin as an additional factor involved in the skeletal remodelling process. Evidences are available which shows that osteoblastic insulin signalling is important for glucose metabolism. The measurement of OC in urine samples could be used as an index of bone turnover in monitoring bone metabolism. In this review, we have tried to explain different roles of OC, however further studies are required to elucidate the metabolic and hormonal role of OC in human body. [Int J Res Med Sci 2016; 4(9.000: 3670-3674

  7. Differences in Bone Quality between High versus Low Turnover Renal Osteodystrophy

    Energy Technology Data Exchange (ETDEWEB)

    Porter, Daniel S. [University of Kentucky, Lexington; Pienkowski, David [University of Kentucky, Lexington; Faugere, Marie-Claude [Albert B. Chandler Medical Center; Malluche, Hartmut H. [Albert B. Chandler Medical Center

    2012-01-01

    Abnormal bone turnover is common in chronic kidney disease (CKD), but its effects on bone quality remain unclear. This study sought to quantify the relationship between abnormal bone turnover and bone quality. Iliac crest bone biopsies were obtained from CKD-5 patients on dialysis with low (n=18) or high (n=17) turnover, and from volunteers (n=12) with normal turnover and normal kidney function. Histomorphometric methods were used to quantify the microstructural parameters; Fourier transform infrared spectroscopy and nanoindentation were used to quantify the material and mechanical properties in bone. Reduced mineral-to-matrix ratio, mineral crystal size, stiffness and hardness were observed in bone with high turnover compared to bone with normal or low turnover. Decreased cancellous bone volume and trabecular thickness were seen in bone with low turnover compared to bone with normal or high turnover. Bone quality, as defined by its microstructural, material, and mechanical properties, is related to bone turnover. These data suggest that turnover related alterations in bone quality may contribute to the known diminished mechanical competence of bone in CKD patients, albeit from different mechanisms for bone with high (material abnormality) vs. low (microstructural alteration) turnover. The present findings suggest that improved treatments for renal osteodystrophy should seek to avoid low or high bone turnover and aim for turnover rates as close to normal as possible.

  8. Low bone turnover phenotype in Rett syndrome

    DEFF Research Database (Denmark)

    Roende, Gitte; Petersen, Janne; Ravn, Kirstine;

    2014-01-01

    Background:Patients with Rett syndrome (RTT) are at risk of having low bone mass and low-energy fractures.Methods:We characterised bone metabolism by both bone formation and resorption markers in blood in a RTT population of 61 girls and women and 122 well-matched healthy controls. Levels of N-te...

  9. Artificial Gravity: Effects on Bone Turnover

    Science.gov (United States)

    Heer, M.; Zwart, S /R.; Baecker, N.; Smith, S. M.

    2007-01-01

    The impact of microgravity on the human body is a significant concern for space travelers. Since mechanical loading is a main reason for bone loss, artificial gravity might be an effective countermeasure to the effects of microgravity. In a 21-day 6 head-down tilt bed rest (HDBR) pilot study carried out by NASA, USA, the utility of artificial gravity (AG) as a countermeasure to immobilization-induced bone loss was tested. Blood and urine were collected before, during, and after bed rest for bone marker determinations. Bone mineral density was determined by DXA and pQCT before and after bed rest. Urinary excretion of bone resorption markers (n-telopeptide and helical peptide) were increased from pre-bed rest, but there was no difference between the control and the AG group. The same was true for serum c-telopeptide measurements. Bone formation markers were affected by bed rest and artificial gravity. While bone-specific alkaline phosphatase tended to be lower in the AG group during bed rest (p = 0.08), PINP, another bone formation marker, was significantly lower in AG subjects than CN before and during bed rest. PINP was lower during bed rest in both groups. For comparison, artificial gravity combined with ergometric exercise was tested in a 14-day HDBR study carried out in Japan (Iwase et al. J Grav Physiol 2004). In that study, an exercise regime combined with AG was able to significantly mitigate the bed rest-induced increase in the bone resorption marker deoxypyridinoline. While further study is required to more clearly differentiate bone and muscle effects, these initial data demonstrate the potential effectiveness of short-radius, intermittent AG as a countermeasure to the bone deconditioning that occurs during bed rest and spaceflight. Future studies will need to optimize not only the AG prescription (intensity and duration), but will likely need to include the use of exercise or other combined treatments.

  10. Role of Soy Protein on Bone Turnover

    Directory of Open Access Journals (Sweden)

    A Haghighian roudsari

    2004-11-01

    Full Text Available Bone mass loss is one of the commonest menopause symptoms, resulting from cessation of estrogen production. Compounds which have estrogen – like biological activity similar to “Isoflavones” present in plants especially soy, may reduce bone loss in postmenopausal women, because as they are similar in structure to estrogens. This study, therefore, was undertaken to assess the effect of soy protein on bone metabolism biomarkers in postmenopausal women with osteopenia. This “before and after” clinical trial was carried out, on 15 postmenopausal women with osteopenia, between 45 to 64 years of age. The subjects were asked to consume 35 gram/day of soy protein for 12 weeks. Blood and urine samples, were taken at 0, 6 and 12 weeks of the study. Anthropometric measurements and a 2-day dietary recall were done at the beginning of the study, and at the 6 and 12 weeks. The food consumption data were analyzed by “Food Proccessor” software. Repeated measurement analysis was utilized to determine the changes in biochemical indices, anthropometric and dietary data. P-values less than 0.05 were considered as significant. Comparison of weight, BMI, physical activity and dietary intake of subjects during the study did not show any significant differences. Soy protein consumption, showed significant reductions in deoxypyridinoline (biochemical marker of bone resorption and significant increase in total alkaline phosphatase ( biochemical marker of bone formation.There were no significant differences in serum osteocalcin, C- telopeptide, insulin- like growth factor binding protein 3 (IGFBP3, and type-I- collagen telopeptides. Considering the beneficial effects of soy protein consumption on bone metabolism biomarkers, inclusion of this inexpensive and available food item in postmenopausal women diet, may reduce bone loss and could be recommended for the prevention of osteoporosis.

  11. Bone growth and turnover in progesterone receptor knockout mice.

    Energy Technology Data Exchange (ETDEWEB)

    Rickard, David J.; Iwaniec, Urszula T.; Evans, Glenda; Hefferan, Theresa E.; Hunter, Jaime C.; Waters, Katrina M.; Lydon, John P.; O' Malley, Bert W.; Khosla, Sundeep; Spelsberg, Thomas C.; Turner, Russell T.

    2008-05-01

    The role of progesterone receptor (PR) signaling in skeletal metabolism is controversial. To address whether signaling through the PR is necessary for normal bone growth and turnover, we performed histomorphometric and mCT analyses of bone from homozygous female PR knockout (PRKO) mice at 6, 12, and 26 weeks of age. These mice possess a null mutation of the PR locus, which blocks the gene expression of A and B isoforms of PR. Body weight gain, uterine weight gain and tibia longitudinal bone growth was normal in PRKO mice. In contrast, total and cortical bone mass were increased in long bones of post-pubertal (12 and 26-week-old) PRKO mice, whereas cancellous bone mass was normal in the tibia but increased in the humerus. The striking 57% decrease in cancellous bone from the proximal tibia metaphysis which occurred between 6 and 26 weeks in WT mice was abolished in PRKO mice. The improved bone balance in aging PRKO mice was associated with elevated bone formation and a tendency toward reduced osteoclast perimeter. Taken together, these findings suggest that PR signaling in mice attenuates the accumulation of cortical bone mass during adolescence and is required for early age-related loss of cancellous bone.

  12. The turnover of Ca47 and Sr85 in bone lesions

    International Nuclear Information System (INIS)

    External counting measurements of local calcium-47 and strontium-85 uptakes and turnover in normal bones and in bone metastases were performed. In many studies serum samples and excretions were collected and assayed. Measurements on patients with bone lesions revealed abnormalities in tracer turnover. 4 figs

  13. Lanthanum carbonate stimulates bone formation in a rat model of renal insufficiency with low bone turnover.

    Science.gov (United States)

    Fumoto, Toshio; Ito, Masako; Ikeda, Kyoji

    2014-09-01

    Control of phosphate is important in the management of chronic kidney disease with mineral and bone disorder (CKD-MBD), for which lanthanum carbonate, a non-calcium phosphate-binding agent, has recently been introduced; however, it remains to be determined whether it has any beneficial or deleterious effect on bone remodeling. In the present study, the effects of lanthanum carbonate were examined in an animal model that mimics low turnover bone disease in CKD, i.e., thyroparathyroidectomized (TPTX) and 5/6 nephrectomized (NX) rats undergoing a constant infusion of parathyroid hormone (PTH) and thyroxine injections (TPTX-PTH-5/6NX). Bone histomorphometry at the second lumbar vertebra and tibial metaphysis revealed that both bone formation and resorption were markedly suppressed in the TPTX-PTH-5/6NX model compared with the sham-operated control group, and treatment with lanthanum carbonate was associated with the stimulation of bone formation but not an acceleration of bone resorption. Lanthanum treatment caused a robust stimulation of bone formation with an activation of osteoblasts on the endosteal surface of femoral diaphysis, leading to an increase in cortical bone volume. Thus, lanthanum carbonate has the potential to stimulate bone formation in cases of CKD-MBD with suppressed bone turnover. PMID:24126694

  14. Calcium phosphate cement delivering zoledronate decreases bone turnover rate and restores bone architecture in ovariectomized rats.

    Science.gov (United States)

    Wu, Chang-Chin; Wang, Chen-Chie; Lu, Dai-Hua; Hsu, Li-Ho; Yang, Kai-Chiang; Lin, Feng-Huei

    2012-06-01

    Patients sustaining bony fractures frequently require the application of bone graft substitutes to fill the bone defects. In the meantime, anti-osteoporosis drugs may be added in bone fillers to treat osteoporosis, especially in postmenopausal women and the elderly. The effects of zoledronate-impregnated calcium phosphate cement (ZLN/CPC) on ovariectomized (OVX) rats were evaluated. OVX rats were implanted with ZLN/CPC, containing 0.025 mg ZLN in the greater omentum. Afterward the clinical sign of toxicity was recorded for eight weeks. The rats were sacrificed and blood samples were collected for hematology and serum bone turnover markers analyses. The four limbs of the rats were harvested and micro-computer tomography (micro-CT) scanning and bone ash analyses were performed. No clinical toxicity was observed in the treated rats. Compared to the OVX rats, levels of bone resorption markers (fragments of C-telopeptides of type I collagen) and bone formation markers (alkaline phosphatase and osteocalcin) decreased significantly in the treated rats. Osteopontin, which mediates the anchoring of osteoclasts to the mineral matrix of bones, also decreased significantly. Micro-CT scanning and histologic examinations of the distal femoral metaphyses showed that the cancellous bone architectures were restored, with a concomitant decrease in bone porosity. The bone mineral content in the bone ashes also increased significantly. This study indicates that ZLN-impregnated CPC reduces bone turnover rate and restores bone architecture in OVX rats. CPC may be an appropriate carrier to deliver drugs to treat osteoporosis, and this approach may also reduce rates of post-dosing symptoms for intravenous ZLN delivery.

  15. Calcium phosphate cement delivering zoledronate decreases bone turnover rate and restores bone architecture in ovariectomized rats

    International Nuclear Information System (INIS)

    Patients sustaining bony fractures frequently require the application of bone graft substitutes to fill the bone defects. In the meantime, anti-osteoporosis drugs may be added in bone fillers to treat osteoporosis, especially in postmenopausal women and the elderly. The effects of zoledronate-impregnated calcium phosphate cement (ZLN/CPC) on ovariectomized (OVX) rats were evaluated. OVX rats were implanted with ZLN/CPC, containing 0.025 mg ZLN in the greater omentum. Afterward the clinical sign of toxicity was recorded for eight weeks. The rats were sacrificed and blood samples were collected for hematology and serum bone turnover markers analyses. The four limbs of the rats were harvested and micro-computer tomography (micro-CT) scanning and bone ash analyses were performed. No clinical toxicity was observed in the treated rats. Compared to the OVX rats, levels of bone resorption markers (fragments of C-telopeptides of type I collagen) and bone formation markers (alkaline phosphatase and osteocalcin) decreased significantly in the treated rats. Osteopontin, which mediates the anchoring of osteoclasts to the mineral matrix of bones, also decreased significantly. Micro-CT scanning and histologic examinations of the distal femoral metaphyses showed that the cancellous bone architectures were restored, with a concomitant decrease in bone porosity. The bone mineral content in the bone ashes also increased significantly. This study indicates that ZLN-impregnated CPC reduces bone turnover rate and restores bone architecture in OVX rats. CPC may be an appropriate carrier to deliver drugs to treat osteoporosis, and this approach may also reduce rates of post-dosing symptoms for intravenous ZLN delivery. (paper)

  16. Estrogen inhibits Dlk1/FA1 production: A potential mechanism for estrogen effects on bone turnover

    DEFF Research Database (Denmark)

    Abdallah, Basem M; Bay-Jensen, Anne-Christine; Srinivasan, Bhuma;

    2011-01-01

    -Dlk1FA1) and its correlation with bone turnover markers. s-Dlk1/FA1 and bone turnover markers (serum cross-linked C-telopeptide [s-CTX] and serum osteocalcin) were measured in two cohorts: a group of pre- and postmenopausal women (n = 100) and a group of postmenopausal women, where half had received...

  17. Influence of orlistat on bone turnover and body composition

    DEFF Research Database (Denmark)

    Gotfredsen, A; Westergren Hendel, H; Andersen, T

    2001-01-01

    was the fU-OHpr/creat ratio, which increased from 12.0 to 20.1 in the OLS group but only from 10.9 to 1 3.2 in the placebo group. CONCLUSION: One year's treatment with OLS induces a lipid malabsorption which enhances a dietary weight loss without any significant deleterious effects on body composition. OLS......OBJECTIVE: To investigate the influence of the pancreas lipase inhibitor orlistat (OLS) on calcium metabolism, bone turnover, bone mass, bone density and body composition when given for obesity as adjuvant to an energy- and fat-restricted diet. DESIGN: Randomized controlled double-blinded trial...... of treatment with OLS 120 mg three times daily or placebo for 1 y. SUBJECTS: Thirty obese subjects with a mean body mass index (BMI) of 36.9+/-3.7 kg/m(2) and a mean age of 41+/-11 y. Sixteen patients were assigned to OLS and 14 to placebo. MEASUREMENTS: Dual energy X-ray absorptiometry (DXA) measurements...

  18. Indoxyl sulfate exacerbates low bone turnover induced by parathyroidectomy in young adult rats.

    Science.gov (United States)

    Hirata, Junya; Hirai, Kazuya; Asai, Hirobumi; Matsumoto, Chiho; Inada, Masaki; Miyaura, Chisato; Yamato, Hideyuki; Watanabe-Akanuma, Mie

    2015-10-01

    Low-turnover bone disease is one of the bone abnormalities observed in patients with chronic kidney disease (CKD) and is recognized to be associated with low serum parathyroid hormone (PTH) level and skeletal resistance to PTH. Indoxyl sulfate (IS) is a representative uremic toxin that accumulates in the blood as renal dysfunction progresses in CKD patients. A recent in vitro study using an osteoblastic cell culture system suggests that IS has an important role in the pathogenesis of low bone turnover through induction of skeletal resistance to PTH. However, the effects of IS on the progression of low bone turnover have not been elucidated. In the present study, we produced rats with low bone turnover by performing parathyroidectomy (PTX) and fed these rats a diet containing indole, a precursor of IS, to elevate blood IS level from indole metabolism. Bone metabolism was evaluated by measuring histomorphometric parameters of secondary spongiosa of the femur. Histomorphometric analyses revealed significant decreases in both bone formation-related parameters and bone resorption-related parameters in PTX rats. In indole-treated PTX rats, further decreases in bone formation-related parameters were observed. In addition, serum alkaline phosphatase activity, a bone formation marker, and bone mineral density of the tibia tended to decrease in indole-treated PTX rats. These findings strongly suggest that IS exacerbates low bone turnover through inhibition of bone formation by mechanisms unrelated to skeletal resistance to PTH. PMID:26112820

  19. Bone turnover in passive smoking female rat: relationships to change in bone mineral density

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    Xu Wen-shuo

    2011-06-01

    Full Text Available Abstract Background Many studies have identified smoking as a risk factor for osteoporosis, but it is unclear whether passive smoking has an effect on bone mineral density and bone turnover and if such an effect could cause osteoporosis.The purpose of the study was to investigate the effect of passive smoking on bone mineral density (BMD and bone turnover and the relationship between BMD and bone turnover in female rat. Methods Forty-eight female Wistar rats were randomized into six groups: 2-month, 3-month,4-month smoke-exposed rats and their controls. A rat model of passive cigarette smoking was prepared by breeding female rats in a cigarette-smoking box for 2, 3 or 4 months. Serums were analyzed for levels of osteocalcin, bone-specific alkaline phosphatase (b-ALP and Tartrate-resistant acid phosphatase 5b (TRACP 5b. BMD was assessed at lumbar vertebrae and femur by dual energy X-ray absorptiometry in passive smoking rats and in control rats. Results BMD of lumbar spine and femur was lower in 4-month smoke-exposed female rats than that in controls. However, there was no significant difference in serum osteocalcin levels between smoke-exposed rats and controls. Significantly lower b-ALP and higher TRACP 5b were found in the 3-month or 4-month smoke-exposed rats compared to controls. Subsequent analysis showed that b-ALP positively correlated with BMD of the lumbar vertebrae(r = 0.764, P = 0.027 and femur(r = 0.899, P = 0.002 in 4-month smoke-exposed female rats. Furthermore, TRACP 5b levels negatively correlated with BMD of lumbar vertebrae (r = -0.871, P = 0.005 and femur (r = -0.715, P = 0.046 in 4-month smoke-exposed female rats. Conclusion Our data suggest that smoke exposure can inhibit bone formation and increase bone resorption. The hazardous effects of passive smoking on bone status are associated with increased bone turnover in female rat.

  20. Bone turnover in passive smoking female rat: relationships to change in bone mineral density

    Science.gov (United States)

    2011-01-01

    Background Many studies have identified smoking as a risk factor for osteoporosis, but it is unclear whether passive smoking has an effect on bone mineral density and bone turnover and if such an effect could cause osteoporosis.The purpose of the study was to investigate the effect of passive smoking on bone mineral density (BMD) and bone turnover and the relationship between BMD and bone turnover in female rat. Methods Forty-eight female Wistar rats were randomized into six groups: 2-month, 3-month,4-month smoke-exposed rats and their controls. A rat model of passive cigarette smoking was prepared by breeding female rats in a cigarette-smoking box for 2, 3 or 4 months. Serums were analyzed for levels of osteocalcin, bone-specific alkaline phosphatase (b-ALP) and Tartrate-resistant acid phosphatase 5b (TRACP 5b). BMD was assessed at lumbar vertebrae and femur by dual energy X-ray absorptiometry in passive smoking rats and in control rats. Results BMD of lumbar spine and femur was lower in 4-month smoke-exposed female rats than that in controls. However, there was no significant difference in serum osteocalcin levels between smoke-exposed rats and controls. Significantly lower b-ALP and higher TRACP 5b were found in the 3-month or 4-month smoke-exposed rats compared to controls. Subsequent analysis showed that b-ALP positively correlated with BMD of the lumbar vertebrae(r = 0.764, P = 0.027) and femur(r = 0.899, P = 0.002) in 4-month smoke-exposed female rats. Furthermore, TRACP 5b levels negatively correlated with BMD of lumbar vertebrae (r = -0.871, P = 0.005) and femur (r = -0.715, P = 0.046) in 4-month smoke-exposed female rats. Conclusion Our data suggest that smoke exposure can inhibit bone formation and increase bone resorption. The hazardous effects of passive smoking on bone status are associated with increased bone turnover in female rat. PMID:21663694

  1. Effect of epimedium pubescen flavonoid on bone mineral status and bone turnover in male rats chronically exposed to cigarette smoke

    Directory of Open Access Journals (Sweden)

    Gao Shu-guang

    2012-06-01

    Full Text Available Abstract Background Epimedii herba is one of the most frequently used herbs in formulas that are prescribed for the treatment of osteoporosis in China and its main constituent is Epimedium pubescen flavonoid (EPF. However, it is unclear whether EPF during chronic exposure to cigarette smoke may have a protective influence on the skeleton. The present study investigated the effect of EPF on bone mineral status and bone turnover in a rat model of human relatively high exposure to cigarette smoke. Methods Fifty male Wistar rats were randomized into five groups: controls, passive smoking groups and passive smoking rats administered EPF at three dosage levels (75, 150 or 300 mg/kg/day in drinking water for 4 months. A rat model of passive smoking was prepared by breeding male rats in a cigarette-smoking box. Bone mineral content (BMC, bone mineral density (BMD, bone turnover markers, bone histomorphometric parameters and biomechanical properties were examined. Results Smoke exposure decreased BMC and BMD, increased bone turnover (inhibited bone formation and stimulated its resorption, affected bone histomorphometry (increased trabecular separation and osteoclast surface per bone surface; decreased trabecular bone volume, trabecular thickness, trabecular number, cortical thickness, bone formation rate and osteoblast surface per bone surface, and reduced mechanical properties. EPF supplementation during cigarette smoke exposure prevented smoke-induced changes in bone mineral status and bone turnover. Conclusion The results suggest that EPF can prevent the adverse effects of smoke exposure on bone by stimulating bone formation and inhibiting bone turnover and bone resorption.

  2. Influence of moderate energy restriction and seafood consumption on bone turnover in overweight young adults

    OpenAIRE

    Lucey, A.J. (Alice J.); Paschos, G.K. (George K.); Cashman, K. D.; J. A. Martinez; Thorsdottir, I; Kiely, M

    2008-01-01

    BACKGROUND: Overweight and obesity are increasing in young adults. However, moderate energy restriction aimed at lowering body weight may promote bone turnover and bone loss. Inclusion of fish or fish oils in a weight-loss diet may attenuate these adverse skeletal effects. OBJECTIVE: We examined the effects of incorporating fish or fish oil into an energy-restricted diet on bone turnover markers in young overweight adults. DESIGN: While following a strict hypoenergetic (-30%...

  3. Recreational football improves bone mineral density and bone turnover marker profile in elderly men

    DEFF Research Database (Denmark)

    Helge, Eva Wulff; Rostgaard Andersen, Thomas; Schmidt, Jakob Friis;

    2014-01-01

    This study examined the effect of recreational football and resistance training on bone mineral density (BMD) and bone turnover markers (BTMs) in elderly men. Twenty-six healthy sedentary men (age 68.2 ± 3.2 years) were randomized into three groups: football (F; n = 9) and resistance training (R; n......), and carboxy-terminal type-1 collagen crosslinks (CTX-1). In F, BMD in PF increased up to 1.8% (P football, OC was 45% and 46% higher (P ... football for elderly men had an osteogenic effect, which was further developed after 12 months, whereas resistance...

  4. [Clinical usefulness of bone turnover markers in the management of osteoporosis].

    Science.gov (United States)

    Yano, Shozo

    2013-09-01

    Osteoporosis is a state of elevated risk for bone fracture due to depressed bone strength, which is considered to be the sum of bone mineral density and bone quality. Since a measure of bone quality has not been established, bone mineral density and bone turnover markers are the only way to evaluate bone strength. Bone turnover markers are classified into bone formation marker and resorption marker, which are correlated with the bone formation rate and resorption rate, respectively, and bone matrix-related marker. Bone is always metabolized; old tissue is resorbed by acids and proteases derived from osteoclasts, whereas new bone is produced by osteoblasts. Bone formation and resorption rates should be balanced (also called coupled). When the bone resorption rate exceeds the formation rate(uncoupled state), bone volume will be reduced. Thus, we can comprehend bone metabolism by measuring both formation and resorption markers at the same time. Increased fracture risk is recognized by elevated bone resorption markers and undercarboxylated osteocalcin, which reflects vitamin K insufficiency and bone turnover. These values and the time course give us helpful information to choose medicine suitable for the patients and to judge the responsiveness. If the value is extraordinarily high without renal failure, metabolic bone disorder or bone metastatic tumor should be considered. Bone quality may be assessed by measuring bone matrix-related markers such as homocystein and pentosidine. Since recent studies indicate that the bone is a hormone-producing organ, it is possible that glucose metabolism or an unknown mechanism could be assessed in the future. PMID:24369600

  5. Biological and within-subject variability of calcium kinetics and biochemical markers of bone turnover

    Science.gov (United States)

    Bone loss is a critical issue during space flight. Evaluating changes in bone and calcium metabolism in astronauts often requires multiple preflight data collection points. Bone turnover and calcium kinetics were measured in 4 healthy subjects, and the day-to-day and between-subject variations were ...

  6. Bone mineral density and markers of bone turnover in patients with renal transplantation and regular hemodialysis

    Directory of Open Access Journals (Sweden)

    Samir M. Ibrahim,. Khalid H Abdel-Mageed, Magdi M El-Sharkawy

    2002-09-01

    Full Text Available Background: Decreased bone mineral density (BMD is a known complication for the uremic state antedating dialysis / renal transplantation (RTx. The issue of stabilized versus continued decrease of BMD especially on long-term basis, continues to be unresolved. Patients and Methods: !"#"hemodialysis (HD-#" $% " &'( &'(-group had been evaluated for metabolic bone changes by calcium homeostasis parameters (serum calcium, phosphorus, alkaline phosphatase "ALP" and vitamin D "calcitriol", markers of bone formation (bone alkaline phosphatase "BAP", osteocalcin "OC", N-terminal propeptide of collagen type I "PINP", bone resorption markers (pyridoline "PYL" and deoxypyridoline "DPYL", and intact parathyroid hormone (iPTH. Also, BMD had been assessed by dual energy x-ray absorptiometry (DEXA twice, at inclusion time and * ! "" Results: comparing both groups regarding calcium homeostasis, markers of bone turnover and iPTH showed non significant difference. However, there was a significant drop of BMD (as evidenced by T-score at follow up in the HD group, compared to stabilization of T-score for the RTx-group. Furthermore, annual T-score change was significantly more in HD-group, compared to RTx-group. Results also showed that, the best marker correlating with T-score annual changes and iPTH to be PINP. Irrespective of normal calcium homeostasis parameters, low BMD is a prevalent disorder among patients on regular HD and renal transplants.Conclusion: Follow up for * ! " %+ ,- ." % """"!to continued bone loss in patients on regular HD. This could raise recommendation for calcium and calcitriol supplementation, especially in the predialysis period, early post transplantation period, and continued guided replacement for those on maintenance HD. Serum PINP showed best correlations with BMD changes and iPTH and could be considered a reliable marker reflecting bone formation in those patients. Keywords: hemodialysis, renal transplantation, markers of bone

  7. Bone turnover markers in medicamentous and physiological hyperprolactinemia in female rats

    OpenAIRE

    Radojković Danijela; Pešić Milica; Ristić Tatjana

    2014-01-01

    Background/Aim. There is a lack of data on the effects of prolactin on calcium metabolism and bone turnover in hyperprolactinemia of various origins. The aim of this study was to compare the influence of medicamentous and physiological hyperprolactinemia on bone turnover in female rats. Methods. Experimental animals (18 weeks old, Wistar female rats) were divided as follows: the group P - 9 rats, 3 weeks pregnant; the group M3-10 rats that were intramuscula...

  8. Gonadal steroid–dependent effects on bone turnover and bone mineral density in men

    Science.gov (United States)

    Finkelstein, Joel S.; Lee, Hang; Leder, Benjamin Z.; Goldstein, David W.; Hahn, Christopher W.; Hirsch, Sarah C.; Linker, Alex; Perros, Nicholas; Servais, Andrew B.; Taylor, Alexander P.; Webb, Matthew L.; Youngner, Jonathan M.; Yu, Elaine W.

    2016-01-01

    BACKGROUND. Severe gonadal steroid deficiency induces bone loss in adult men; however, the specific roles of androgen and estrogen deficiency in hypogonadal bone loss are unclear. Additionally, the threshold levels of testosterone and estradiol that initiate bone loss are uncertain. METHODS. One hundred ninety-eight healthy men, ages 20–50, received goserelin acetate, which suppresses endogenous gonadal steroid production, and were randomized to treatment with 0, 1.25, 2.5, 5, or 10 grams of testosterone gel daily for 16 weeks. An additional cohort of 202 men was randomized to receive these treatments plus anastrozole, which suppresses conversion of androgens to estrogens. Thirty-seven men served as controls and received placebos for goserelin and testosterone. Changes in bone turnover markers, bone mineral density (BMD) by dual-energy x-ray absorptiometry (DXA), and BMD by quantitative computed tomography (QCT) were assessed in all men. Bone microarchitecture was assessed in 100 men. RESULTS. As testosterone dosage decreased, the percent change in C-telopeptide increased. These increases were considerably greater when aromatization of testosterone to estradiol was also suppressed, suggesting effects of both testosterone and estradiol deficiency. Decreases in DXA BMD were observed when aromatization was suppressed but were modest in most groups. QCT spine BMD fell substantially in all testosterone-dose groups in which aromatization was also suppressed, and this decline was independent of testosterone dose. Estradiol deficiency disrupted cortical microarchitecture at peripheral sites. Estradiol levels above 10 pg/ml and testosterone levels above 200 ng/dl were generally sufficient to prevent increases in bone resorption and decreases in BMD in men. CONCLUSIONS. Estrogens primarily regulate bone homeostasis in adult men, and testosterone and estradiol levels must decline substantially to impact the skeleton. TRIAL REGISTRATION. ClinicalTrials.gov, NCT00114114

  9. Changes in Bone Turnover Markers and Bone Mass with Reducing Levels of Jumping Exercise Regimens in Female Rats

    OpenAIRE

    Ooi, Foong Kiew; Singh, Rabindarjeet; Singh, Harbindar Jeet

    2012-01-01

    Purpose To date, little is known about the effects of a reduced level of jumping exercise regimens on bone turnover markers and mass. This study investigates the effects of different jumping exercise regimens with varying exercise loads on serum bone turnover markers and bone mass in female rats. Methods A total of 144 female rats aged 12 weeks, were divided into 12 groups as follows: no exercise for 8 (8S) or 32 weeks (32S), or 8 weeks of standard training program (8STP) consisting of 200 ju...

  10. Effect of Epimedium-derived Phytoestrogen on Bone Turnover and Bone Microarchitecture in OVX-induced Osteoporotic Rats

    Institute of Scientific and Technical Information of China (English)

    Songlin PENG; Renyun XIA; Huang FANG; Feng LI; Anmin CHEN; Ge ZHANG; Ling QIN

    2008-01-01

    To investigate the preventive effect of epimedium-defivod phytoestrogen (PE) on osteoporosis induced by ovariectomy (OVX) in rats, 11-month-old female Wistar rats were randomly di- vided into Sham, OVX and PE groups. One week after OVX, daily oral administration of PE (0.4 g·kg-1·day·-1) started in PE group, and rats in Sham and OVX groups were given vehicle accordingly. The administrations lasted for 12 weeks. The biological markers including serum osteocalcin (OC) and urinary deoxypyridinoline (DPD) for bone turnover were evaluated at the end of the 12th week. On the 13th week, all the rats were sacrificed. The right proximal tibiae were removed, subjected to micro CT for determination of trabeonlar bone structure and then bone histomorphometry was per- formed to assess bone remodeling. The OVX rats were in a high bone turnover status as evidenced by increased bone formation markers and bone resorption markers. Treatment with PE could suppress the high bone turnover rate in OVX rats. Micro CT data revealed that PE treatment could ameliorate the deterioration of the micro-architecture of proximal tibiae induced by OVX, as demonstrated by greater bone volume, increased trabecular thickness and less trahecular separation in PE group in comparison with OVX group. The static and dynamic parameters of bone histomorphometry indi- cated that there were significant increases in bone formation variables and significant decreases in bone resorption variables between PE and OVX groups. The findings suggest that PE has a beneficial effect on trabecular bone in OVX rat model and this effect is possibly associated with stimulation of bone formation as well as inhibition of bone resorption.

  11. Effects of denosumab on bone mineral density and bone turnover in postmenopausal women.

    Science.gov (United States)

    Wensel, Terri M; Iranikhah, Maryam M; Wilborn, Teresa W

    2011-05-01

    Osteoporosis is a degenerative bone disease affecting approximately 10 million American adults. Several options are available to prevent development of the disease or slow and even stop its progression. Nonpharmacologic measures include adequate intake of calcium and vitamin D, exercise, fall prevention, and avoidance of tobacco and excessive alcohol intake. Current drug therapy includes bisphosphonates, calcitonin, estrogen or hormone therapy, selective estrogen receptor modulators, and teriparatide. Denosumab, a receptor activator of nuclear factor-K B ligand (RANKL) inhibitor, was recently approved by the United States Food and Drug Administration for treatment of postmenopausal osteoporosis. Patients treated with denosumab experienced significant gains in bone mineral density, rapid reductions in markers of bone turnover, and a reduced risk for new vertebral fracture. Compared with placebo, patients receiving denosumab 60 mg subcutaneously once every 6 months experienced gains in bone mineral density of 6.5-11% when treated for 24-48 months. One trial demonstrated the superiority of denosumab compared with alendronate, but the differences were small. The most common adverse reactions to denosumab include back pain, pain in extremities, musculoskeletal pain, and cystitis. Serious, but rare, adverse reactions include the development of serious infections, dermatologic changes, and hypocalcemia. The recommended dosing of denosumab is 60 mg every 6 months as a subcutaneous injection in the upper arm, upper thigh, or abdomen. Although beneficial effects on bone mineral density and fracture rate have been established in clinical trials, the risks associated with denosumab must be evaluated before therapy initiation. Of concern is the risk of infection, and denosumab should likely be avoided in patients taking immunosuppressive therapy or at high risk for infection. Therefore, bisphosphonates will likely remain as first-line therapy. Denosumab should be considered in

  12. Does vitamin D supplementation of healthy Danish Caucasian girls affect bone turnover and bone mineralization?

    DEFF Research Database (Denmark)

    Molgaard, C.; Larnkjaer, A.; Cashman, K.D.;

    2010-01-01

    and after 12 months whereas physical activity and dietary intake of calcium and vitamin D were assessed at baseline. Serum (S) 25-hydroxyvitamin D (25OHD), S-osteocalcin, S-parathyroid hormone, S-calcium, S-inorganic phosphate, urinary (U) pyridinoline (Pyr) and deoxpyridinoline (Dpyr) were measured...... be limited but the effect of vitamin D supplementation in adolescence on bone mass is not well established. Objective: To investigate the effect of supplementation with 5 and 10 mu g/day vitamin D-3 for 12 months in 11- to 12-year-old girls on bone mass and bone turnover as well as the possible influence...... at baseline and after 6 and 12 months. Results: The S-25OHD concentration increased (p mean +/- SD; 11.0 +/- 10.3 nmol/l, baseline 41.9 +/- 17.6 nmol/l) or 10 mu g/day (13.3 +/- 11.8 nmol/l, baseline 44.4 +/- 16.6 nmol...

  13. Arthritis induces early bone high turnover, structural degradation and mechanical weakness.

    Directory of Open Access Journals (Sweden)

    Bruno Vidal

    Full Text Available We have previously found in the chronic SKG mouse model of arthritis that long standing (5 and 8 months inflammation directly leads to high collagen bone turnover, disorganization of the collagen network, disturbed bone microstructure and degradation of bone biomechanical properties. The main goal of the present work was to study the effects of the first days of the inflammatory process on the microarchitecture and mechanical properties of bone.Twenty eight Wistar adjuvant-induced arthritis (AIA rats were monitored during 22 days after disease induction for the inflammatory score, ankle perimeter and body weight. Healthy non-arthritic rats were used as controls for compar-ison. After 22 days of disease progression rats were sacrificed and bone samples were collected for histomorphometrical, energy dispersive X-ray spectroscopical analysis and 3-point bending. Blood samples were also collected for bone turnover markers.AIA rats had an increased bone turnover (as inferred from increased P1NP and CTX1, p = 0.0010 and p = 0.0002, respectively and this was paralleled by a decreased mineral content (calcium p = 0.0046 and phos-phorus p = 0.0046. Histomorphometry showed a lower trabecular thickness (p = 0.0002 and bone volume (p = 0.0003 and higher trabecular sepa-ration (p = 0.0009 in the arthritic group as compared with controls. In addition, bone mechanical tests showed evidence of fragility as depicted by diminished values of yield stress and ultimate fracture point (p = 0.0061 and p = 0.0279, re-spectively in the arthritic group.We have shown in an AIA rat model that arthritis induc-es early bone high turnover, structural degradation, mineral loss and mechanical weak-ness.

  14. Correlation of Serum Leptin Level with Bone Mineral Density and Bone Turnover Markers in Chinese Adolescent Dancers

    Institute of Scientific and Technical Information of China (English)

    LI-CHEN YANG; YAN LAN; JING HU; YAN-HUA YANG; QIAN ZHANG; JIAN-HUA PIAO

    2009-01-01

    Objective To investigate plasma leptin concentrations in adolescent female dancers and to determine whether leptin has some effects on their bone mineral density (BMD) and bone turnover markers. Methods Sixty dancers aged 15-17 years and 77 healthy controls were enrolled in the study. Bone mineral density (BMD) and body composition were detected by dual energy X-ray absorptiometry. Serum leptin concentrations were measured by radioimmunoassay (RIA). Two bone turnover markers, bone-specific alkaline phosphatase (BAP) and tartrate-resistant acid phosphatase(TRACP), were determined by ELISA. Results The dancers had a lower fat mass and a lower leptin level than the controls, while they had a relatively higher BMD of the total body and legs after adjustment for BMI and age. The levels of bone resorption and formation of markers were higher in the dancers than in the controls. Leptin was positively correlated with BMI, body weight, fat mass, and percentage of body fat. In dancers, Leptin was positively correlated with the BMD of the total body and the left leg. However, after adjustment for BMI, no correlation of serum leptin concentrations with BMD values was found in either dancers or controls. Nor correlation was found between leptin and bone turnover markers after adjustment for BMI. Conclusion The leptin profile is different between the controls and the dancers with a lower BMI and a lower fat mass. Circulating plasma leptin level depends on BMI and is not a direct determinant of BMD in Chinese adolescent dancers.

  15. Relationship between Mandibular BMD and Bone Turnover Markers in Osteoporosis Diagnosis

    OpenAIRE

    SM Eshaghi; A Hossein-nezhad; Zh Maghbooli; Larijani, B

    2008-01-01

    "nBackground: The purpose of the present study was to determine mandible bone mineral density and evaluate its correlation with central BMD and bone turnover."nMethods: Two hundred and seven postmenopausal women were enrolled in this cross-sectional study. After receiving the tes­timonials, questionnaires were completed and physical exams were done. For all participants central BMD was measured through DXA method. In each women periapical radiography performed in two regions...

  16. Associations between Serum Leptin Level and Bone Turnover in Kidney Transplant Recipients

    OpenAIRE

    Kovesdy, Csaba P.; Molnar, Miklos Z.; Czira, Maria E.; Rudas, Anna; Ujszaszi, Akos; Rosivall, Laszlo; Szathmari, Miklos; Covic, Adrian; Keszei, Andras; Beko, Gabriella; Lakatos, Peter; Kosa, Janos; Mucsi, Istvan

    2010-01-01

    Background and objectives: Obesity is associated with increased parathyroid hormone (PTH) in the general population and in patients with chronic kidney disease (CKD). A direct effect of adipose tissue on bone turnover through leptin production has been suggested, but such an association has not been explored in kidney transplant recipients.

  17. Correlation of the Levels of the Bone Turnover Markers BAP and β-CTX with Bone Metastasis Progress in Lung Cancer Patients

    OpenAIRE

    Tang, Qiong; Zhao, Hui; JIA, RUI; Liu, Linlin

    2013-01-01

    Background and objective Bone metastasis is common in lung cancer patients. The β isomer of the C-terminal telopeptide of type I collagen (β-CTX) and bone-specific alkaline phosphates (BAP) are regarded as important bone turnover markers in bone resorption and formation. Thus, the aims of this study are to determine the correlation of these bone turnover markers with the extent of bone metastasis of lung cancer. Methods A total of 92 patients with bone metastasis of lung cancer from Tianjin U...

  18. Dynamic contrast-enhanced MRI in Paget's disease of bone-correlation of regional microcirculation and bone turnover

    Energy Technology Data Exchange (ETDEWEB)

    Libicher, M. [University of Cologne, Department of Radiology, Cologne (Germany); Klinikum der Universitaet zu Koeln, Radiologische Klinik, Koeln (Germany); Kasperk, C. [University of Heidelberg, Department of Medicine, Division of Osteology, Heidelberg (Germany); Daniels, M.; Hosch, W. [University of Heidelberg, Department of Radiology, Heidelberg (Germany); Kauczor, H.U.; Delorme, S. [German Cancer Research Center, Department of Radiology, Heidelberg (Germany)

    2008-05-15

    The purpose of this study was to evaluate regional microcirculation in Paget's disease of bone (PD) with dynamic contrast-enhanced MR imaging (DCE-MRI). Additionally, we correlated regional bone perfusion with alkaline phosphatase as serum marker of bone turnover. We examined 71 patients with PD (27 men, 44 women, 67{+-}10 years) localized at the axial and appendicular skeleton. Contrast uptake was analyzed using a two-compartment model with the output variables amplitude A and exchange rate constant k{sub ep}. Color-coded parametric images were generated to visualize microcirculation. Serum levels of alkaline phosphatase (AP) were compared with DCE-MRI parameters. Amplitude A and exchange rate constant k{sub ep} were significantly increased in PD compared to unaffected bone (A{sub PD} 0.81{+-}0.24 vs. A{sub control} 0.34{+-}0.1 and k{sub ep} {sub PD} 4.0 {+-}2.86 vs. k{sub ep} {sub control} 1.73 {+-}0.88, p <0.001). There was a significant correlation (r{sub s}=0.5-0.7) of DCE-MRI parameters and AP at the axial (pelvis, spine) and appendicular skeleton (femur, tibia). The long bones showed increased circulation of the advancing peripheral zones and no vascularization of the central part, which had been replaced by fatty tissue. Regional microcirculation in PD is inhomogeneous with focal areas of excessive hypervascularity, especially in the advancing peripheral zone. There is a significant correlation of bone circulation and bone turnover in PD. DCE-MRI might therefore be a diagnostic tool for monitoring therapeutic effects of bisphoshonates in Paget's disease of bone. (orig.)

  19. Associations of total, dairy, and meat protein with markers for bone turnover in healthy, prepubertal boys

    DEFF Research Database (Denmark)

    Budek, Alicja Zofia; Hoppe, Camilla; Michaelsen, Kim Fleischer;

    2007-01-01

    , dairy, and meat protein intake with markers for bone turnover and sIGF-I in prepubertal, healthy boys (n ¼ 81). We measured bone turnover (enzyme-linked immunoassay) in serum osteocalcin (sOC), bone-specific alkaline phosphatase (sBAP), and C-terminal telopeptide of collagen type-I (sCTX); dietary...... with sBAP and sCTX. Further analyses showed that dairy protein decreased (P ¼ 0.05) sOC at a high meat protein intake (.0.8 g/kg), whereas meat protein increased (P ¼ 0.03) sOC at a low dairy protein intake (,0.4 g/kg). Total and meat protein intake was positively associated with sBAP (P # 0...

  20. A role for PERK in the mechanism underlying fluoride-induced bone turnover

    International Nuclear Information System (INIS)

    While it has been well-documented that excessive fluoride exposure caused the skeletal disease and osteoblasts played a critical role in the advanced skeletal fluorosis, the underlying mechanism that mediated these effects remain poorly understood. The present study was undertaken to examine the effect of fluoride on bone of rats and MC3T3-E1 cells in vitro. Herein we found pathological features of high bone turnover in fluoride-treated rats, which was supported by an increase of osteogenic and osteoclastogenic genes expression in different stages of fluoride exposure. The skeletal toxicity of fluoride was accompanied by activation of endoplasmic reticulum (ER) stress and subsequent unfolded protein response (UPR). A novel finding of this study was that expression of PKR-like endoplasmic reticulum kinase (PERK) was the same trend with receptor activator for nuclear factor-κ B ligand (RANKL), and NF-E2 p45-related factor 2 (Nrf2) was the same trend with Runt-related transcription factor 2 (Runx2) in bones of rats exposed to varied fluoride condition. Based on these data, we hypothesized that up-regulation of PERK probably played a role in mediating bone turnover induced by fluoride. Action of fluoride on MC3T3-E1 cells differentiation was demonstrated through analysis of alkaline phosphatase (ALP) activity and mineralized nodules formation. Meantime, an increase of binding immunoglobulin protein (BiP) expression indicated the active ER stress in cells exposed to various dose of fluoride. Blocking PERK expression using siRNA showed the obvious decrease of osteogenic and osteoclastogenic factors expression in MC3T3-E1 cells exposed to certain dose of fluoride that could positively stimulate osteoblastic viability. In conclusion these findings underscore the importance of PERK in modulating fluoride induced bone formation and bone resorption. Understanding the link between PERK and bone turnover could probe into the mechanism underlying different bone lesion of

  1. Stanozolol Decreases Bone Turnover Markers, Increases Mineralization, and Alters Femoral Geometry in Male Rats.

    Science.gov (United States)

    Nebot, E; Aparicio, V A; Camiletti-Moirón, D; Martinez, R; Erben, R G; Kapravelou, G; Sánchez-González, C; De Teresa, C; Porres, J M; López-Jurado, M; Aranda, P; Pietschmann, P

    2016-06-01

    Stanozonol (ST) is a synthetic derivative of testosterone; it has anabolic/androgenic activity, increasing both the turnover of trabecular bone and the endocortical apposition of bone. The present study aimed to examine the effects of ST on bone status in rats by bone mineral content, markers of formation and resorption, bone density, and structural and microarchitectural parameters. Twenty male Wistar rats were randomly distributed into two experimental groups corresponding to placebo or ST administration, which consisted of weekly intramuscular injections of 10 mg/kg body weight of ST. Plasma parameters were analyzed by immunoassay. Bone mineral content was determined by spectrophotometry. Bone mineral density (BMD) and structural parameters were measured by peripheral quantitative computed tomography, and trabecular and cortical microarchitecture by micro-computed tomography. Plasma Ca, Mg, and alkaline phosphatase were higher, and urinary Ca excretion, corticosterone, and testosterone concentrations lower in the ST group. Femur Ca content was higher and P content was lower in the ST, whereas osteocalcin, aminoterminal propeptides of type I procollagen, and C-terminal telopeptides of type I collagen were lower. Total cross-sectional, trabecular, and cortical/subcortical areas were lower in the ST. No differences were observed on BMD and area parameters of the diaphysis as well as on trabecular and cortical microarchitecture. The use of ST increases bone mineralization, ash percentage, and Ca and Mg content in femur. In spite of an absence of changes in BMD, geometric metaphyseal changes were observed. We conclude that ST alters bone geometry, leads to low bone turnover, and thus may impair bone quality. PMID:26801156

  2. Alveolar bone grafting in association with polyostotic fibrous dysplasia and bisphosphonate-induced abnormal bone turnover in a bilateral cleft lip and palate patient: a case report.

    Science.gov (United States)

    Kodama, Yasumitsu; Ogose, Akira; Oguri, Yoshimitsu; Ubaidus, Sobhan; Iizuka, Tateyuki; Takagi, Ritsuo

    2012-09-01

    A case is presented of extensive alveolar bone grafting in a patient with bilateral cleft lip and palate and polyostotic fibrous dysplasia. The patient previously underwent bisphosphonate therapy. Because of an abnormal and often decreased bone turnover caused by the fibrous dysplasia and the bisphosphonate therapy, bone grafting in such a patient poses several potential difficulties. In addition, the histomorphometric analysis of the bone grafts showed markedly decreased bone turnover. However, alveolar bone grafting using the iliac crest was performed successfully. Sufficient occlusion was achieved by postoperative low-loading orthodontic treatment.

  3. The role of biochemical of bone turnover markers in osteoporosis and metabolic bone disease: a consensus paper of the Belgian Bone Club.

    Science.gov (United States)

    Cavalier, E; Bergmann, P; Bruyère, O; Delanaye, P; Durnez, A; Devogelaer, J-P; Ferrari, S L; Gielen, E; Goemaere, S; Kaufman, J-M; Toukap, A Nzeusseu; Reginster, J-Y; Rousseau, A-F; Rozenberg, S; Scheen, A J; Body, J-J

    2016-07-01

    The exact role of biochemical markers of bone turnover in the management of metabolic bone diseases remains a topic of controversy. In this consensus paper, the Belgian Bone Club aimed to provide a state of the art on the use of these biomarkers in different clinical or physiological situations like in postmenopausal women, osteoporosis in men, in elderly patients, in patients suffering from bone metastasis, in patients with chronic renal failure, in pregnant or lactating women, in intensive care patients, and in diabetics. We also gave our considerations on the analytical issues linked to the use of these biomarkers, on potential new emerging biomarkers, and on the use of bone turnover biomarkers in the follow-up of patients treated with new drugs for osteoporosis. PMID:27026330

  4. The regulation of bone turnover in ameloblastoma using an organotypic in vitro co-culture model

    Science.gov (United States)

    Eriksson, Tuula M; Day, Richard M; Fedele, Stefano; Salih, Vehid M

    2016-01-01

    Ameloblastoma is a rare, odontogenic neoplasm with benign histopathology, but extensive, local infiltrative capacity through the bone tissue it originates in. While the mechanisms of ameloblastoma invasion through the bone and bone absorption are largely unknown, recent investigations have indicated a role of the osteoprotegerin/receptor activator of nuclear factor kappa-B ligand regulatory mechanisms. Here, we present results obtained using a novel in vitro organotypic tumour model, which we have developed using tissue engineering techniques. Using this model, we analysed the expression of genes involved in bone turnover and detected a 700-fold increase in receptor activator of nuclear factor kappa-B ligand levels in the co-culture models with ameloblastoma cells cultured with bone cells. The model described here can be used for gene expression studies, as a basis for drug testing or for a more tailored platform for testing of the behaviour of different ameloblastoma tumours in vitro.

  5. Common bone turnover markers in rheumatoid arthritis and ankylosing spondylitis: a literature review.

    Science.gov (United States)

    Coiffier, Guillaume; Bouvard, Béatrice; Chopin, Florance; Biver, Emmanuel; Funck-Brentano, Thomas; Garnero, Patrick; Guggenbuhl, Pascal

    2013-05-01

    We studied the impact of inflammatory rheumatism and its treatment on the most common bone turnover markers, based on six previously defined questions in a systematic literature review in order to define their place in daily clinical practice. The role of bone is currently considered of particular importance concerning cartilage damage in inflammatory rheumatism (rheumatoid arthritis and ankylosing spondylitis) and the new concept of osteoimmunology has emerged. Some bone turnover markers are available in clinical practice. In spite of rich and extensive literature on bone turnover markers, their use in inflammatory rheumatism or even osteoporosis is not clear, and a systematic literature review became necessary. In spite of a large number of different markers used in literature, few of them that are useful in common practice have been studied in the field of inflammatory rheumatism such as rheumatoid arthritis and ankylosing spondylitis. Although their study enables understanding of the physiopathological mechanisms of osteoporosis in inflammatory rheumatism, their use in current common practice cannot be recommended. Interesting data on the forecast of the structural evolution of rheumatoid arthritis has been found within the framework of clinical research, without any real practical impact today.

  6. Elevated Bone Turnover in an Infantile Patient with Mucolipidosis II; No Association with Hyperparathyroidism

    Science.gov (United States)

    Otomo, Takanobu; Yamamoto, Takehisa; Fujikawa, Yasuhiro; Shimotsuji, Tsunesuke; Ozono, Keiichi

    2011-01-01

    This present report concerns an infantile patient with mucolipidosis II, who showed transient cortical bone hyperostosis followed by severe osteopenia. The diagnosis of mucolipidosis II was made based on the leakage of lysosomal enzymes in serum and conditioned media of the patient's skin fibroblasts, low activity of lysosomal enzymes of the fibroblasts and mutation of c.2086_2089insC (p.L697fs) and c.3565C>T (p.R1189X) in the GNPTAB gene. Bone X-ray analysis demonstrated a periosteal reaction and elevated bone resorption at the age of 2 mo. Bone markers, including alkaline phosphatase, osteocalcin and urine deoxypyridinoline, also indicated a high turnover of bone metabolism; however, no apparent rickets-like changes and no increased levels of PTH were observed. Elevated bone resorption is possibly associated with the leakage of lysosomal enzyme from osteoclasts into bone matrices. Bone formation gradually reduced, and increased bone resorption persisted. This led to severe osteopenia at the age of 6 mo. Characteristic bone findings may contribute to early diagnosis of mucolipidosis II, but their pathogenesis remains to be clarified. PMID:23926388

  7. Low bone turnover and low BMD in Down syndrome: effect of intermittent PTH treatment.

    Directory of Open Access Journals (Sweden)

    Tristan W Fowler

    Full Text Available Trisomy 21 affects virtually every organ system and results in the complex clinical presentation of Down syndrome (DS. Patterns of differences are now being recognized as patients' age and these patterns bring about new opportunities for disease prevention and treatment. Low bone mineral density (BMD has been reported in many studies of males and females with DS yet the specific effects of trisomy 21 on the skeleton remain poorly defined. Therefore we determined the bone phenotype and measured bone turnover markers in the murine DS model Ts65Dn. Male Ts65Dn DS mice are infertile and display a profound low bone mass phenotype that deteriorates with age. The low bone mass was correlated with significantly decreased osteoblast and osteoclast development, decreased bone biochemical markers, a diminished bone formation rate and reduced mechanical strength. The low bone mass observed in 3 month old Ts65Dn mice was significantly increased after 4 weeks of intermittent PTH treatment. These studies provide novel insight into the cause of the profound bone fragility in DS and identify PTH as a potential anabolic agent in the adult low bone mass DS population.

  8. Interleukin-6 is not essential for bone turnover in hypothyroid mice.

    Directory of Open Access Journals (Sweden)

    Maria Gorska

    2008-01-01

    Full Text Available Interleukin-6 (IL-6 has been shown to be involved in the pathogenesis of several bone diseases characterized by an imbalance between bone resorption and formation. The aim of the study was to estimate serum markers of bone turnover: osteoclast-derived tartrate-resistant acid phosphatase form 5a (TRACP 5b and osteocalcin in IL-6-deficient mice to assess the role of IL-6 in bone metabolism in hypothyroidism in mice. C57BL/6J (wild-type; WT and C57BL/6J(IL6-/-Kopf (IL-6 knock-out; IL6KO mice randomly divided into 4 groups with 10 in each one: 1/ WT mice in hypothyroidism (WT-ht, 2/ WT controls, 3/ IL6KO mice with hypothyroidism (IL6KO-ht and 4/ IL6KO controls. Experimental model of hypothyroidism was induced by intraperitoneal injection of propylthiouracyl. The serum levels of TRACP 5b and osteocalcin were determined by ELISA. Serum concentrations of TRACP 5b (median and interquartile ranges were significantly decreased in both groups of mice with hypothyroidism: WT (3.2 (2.5-4.7 U/l and IL6KO (2.6 (1.8-3.5 U/l as compared to the respective controls. Similarly, serum osteocalcin levels were significantly reduced in both groups of mice in experimental hypothyroidism: WT (25.8 (23.0-28.2 ng/ml and IL6KO (21.5(19.0-24.6 ng/ml in comparison to the respective controls. There were no significant differences in bone turnover markers between IL6KO and WT mice both in hypothyroid and control animals. The results of the present study suggest that IL-6 does not play an important role in bone turnover in both euthyroid and hypothyroid mice.

  9. Effects of Fructus Ligustri Lucidi extract on bone turnover and calcium balance in ovariectomized rats.

    Science.gov (United States)

    Zhang, Yan; Lai, Wan-Ping; Leung, Ping-Chung; Wu, Chun-Fu; Yao, Xin-Sheng; Wong, Man-Sau

    2006-02-01

    The aim of this study was to evaluate the effect of Fructus Ligustri Lucidi (FLL), a kidney-tonifying Chinese herbal medicine, on the biochemical markers of bone turnover, calcium metabolism and balance in osteoporotic rat model developed by ovariectomy. Four weeks after surgical operation, animals were randomly assigned to one of the four treatments for 14 weeks: sham-operated control treated with vehicle (sham, n=8), ovariectomized group treated with vehicle (OVX, n=8), OVX group treated with 17beta-estradiol (E(2), n=10, 2 microg/kg/d) and OVX group treated with FLL extracts (FLL, n=10, 550 mg/kg/d). Serum osteocalcin and urinary deoxypyridinoline levels were upregulated in rats in response to OVX, suggesting that the bone turnover rate was accelerated in these animals. Treatment of OVX rats with FLL extract could prevent OVX-induced increase in bone turnover by suppression of both serum osteocalcin (pcalcium in rats by increasing the intestinal calcium absorption rate (pcalcium content (pcalcium balance in OVX rats and it might be a potential candidate for prevention and treatment of postmenopausal osteoporosis.

  10. Effects of short-term testosterone replacement on areal bone mineral density and bone turnover in young hypogonadal males

    Directory of Open Access Journals (Sweden)

    Prasun Deb

    2012-01-01

    Full Text Available Context: Effect of parenteral testosterone esters administration on bone-mineral density (BMD and bone turnover in young age onset male hypogonadism is not studied in Indian subjects. Aims: To prospectively study the effect of short-term (6 months replacement therapy with parenteral testosterone enanthate-propionate combination on BMD and bone turnover markers in hypogonadal adult patients. Settings and Design: Prospective, tertiary care academic center. Materials and Methods: Thirteen young, otherwise healthy hypogonadal males (age 25.5 ± 4.9 yrs, serum testosterone 2.56 ± 4.29 nmol/l were subjected to BMD measurements (DXA and estimation of urinary Crosslaps™ and serum osteocalcin at baseline. Twelve healthy age and BMI-matched males served as controls for BMD measurements. The hypogonadal patients were administered parenteral testosterone esters (as mixed enanthate and propionate 250 mg i.m. every 2-3 weeks, and prospectively followed for 6 months. BMD and bone markers were studied at the end of 6 months. Statistical Analysis Used: Mann-Whitney nonparametric test, paired t-test and Pearson′s test of two-tail significance. Results: At baseline, BMD was significantly lower in hypogonadal males as compared to that in controls. With testosterone replacement, there was significant improvement in BMD, both at trabecular and cortical sites, There was a decline in bone turnover with treatment (Ur Crosslaps™:creatinine ratio: pretreatment 72.8 ± 40.4, post-treatment 35.5 ± 23.8 μg/mmol, P = 0.098; serum osteocalcin: pre-treatment 41.0 ± 16.8, post-treatment 31.7 ± 2.1 ng/ml, P = 0.393. Conclusions: Short-term parenteral testosterone replacement significantly improves BMD at the hip, lumbar spine and forearm in hypogonadal young males.

  11. Decreased bone turnover with balanced resorption and formation prevent cortical bone loss during disuse (hibernation) in grizzly bears (Ursus arctos horribilis).

    Science.gov (United States)

    McGee, Meghan E; Maki, Aaron J; Johnson, Steven E; Nelson, O Lynne; Robbins, Charles T; Donahue, Seth W

    2008-02-01

    Disuse uncouples bone formation from resorption, leading to increased porosity, decreased bone geometrical properties, and decreased bone mineral content which compromises bone mechanical properties and increases fracture risk. However, black bear bone properties are not adversely affected by aging despite annual periods of disuse (i.e., hibernation), which suggests that bears either prevent bone loss during disuse or lose bone and subsequently recover it at a faster rate than other animals. Here we show decreased cortical bone turnover during hibernation with balanced formation and resorption in grizzly bear femurs. Hibernating grizzly bear femurs were less porous and more mineralized, and did not demonstrate any changes in cortical bone geometry or whole bone mechanical properties compared to active grizzly bear femurs. The activation frequency of intracortical remodeling was 75% lower during hibernation than during periods of physical activity, but the normalized mineral apposition rate was unchanged. These data indicate that bone turnover decreases during hibernation, but osteons continue to refill at normal rates. There were no changes in regional variation of porosity, geometry, or remodeling indices in femurs from hibernating bears, indicating that hibernation did not preferentially affect one region of the cortex. Thus, grizzly bears prevent bone loss during disuse by decreasing bone turnover and maintaining balanced formation and resorption, which preserves bone structure and strength. These results support the idea that bears possess a biological mechanism to prevent disuse osteoporosis.

  12. Bone Turnover Does Not Reflect Skeletal Aging in Older Hispanic Men with Type 2 Diabetes

    Science.gov (United States)

    Rianon, N.; McCormick, J.; Ambrose, C.; Smith, S. M.; Fisher-Hoch, S.

    2016-01-01

    The paradox of fragility fracture in the presence of non-osteoporotic bone mineral density in older patients with type 2 diabetes mellitus (DM2) makes it difficult to clinically predict fracture in this vulnerable group. Serum osteocalcin (OC), a marker of bone turnover, increases with normal skeletal aging indicating risk of fracture. However, OC has been reported to be lower in patients with DM2. An inverse association between higher glycated hemoglobin levels (HbA1c) and lower serum OC in older DM2 patients triggered discussions encouraging further investigation. A key question to be answered is whether changes in glucose metabolism is responsible for bone metabolic changes, ultimately leading to increased risk of fragility fractures in DM2 patients. While these studies were conducted among Caucasian and Asian populations, this has not been studied in Hispanic populations who suffer from a higher prevalence of DM2. The Cameron County Hispanic Cohort (CCHC) in Texas is a homogeneous Hispanic cohort known to have high prevalence of DM2 (30%). Our preliminary data from this cohort reported OC levels lower than the suggested threshold for fragility fracture in post-menopausal women. We further investigated whether bone turnover in older CCHC adults with DM2 show a normal pattern of skeletal aging. Samples and data were obtained from a nested cohort of 68 (21 men and 47 women) Hispanic older adults (=50 years) who had a diagnosis of DM2. Given high prevalence of uncontrolled DM2 in this cohort, we divided population into two groups: i) poor DM2 control with HbA1c level =8 (48% men and 38% women) and ii) good DM2 control with HbA1c level <8). A crosssectional analysis documented associations between serum OC and age adjusted HbA1c levels. There was no direct association between age and OC concentrations in our study. Higher HbA1c was associated with lower serum OC in men (odds ratio -6.5, 95% confidence interval -12.7 to - 0.3, p < 0.04). No significant associations

  13. Impact of Black seed (Nigella sativa extract on bone turnover markers in postmenopausal women with osteoporosis

    Directory of Open Access Journals (Sweden)

    N Valizadeh

    2010-01-01

    Full Text Available "n "n  "n  "nBackground and the purpose of the study: "nExperimental studies have shown that Ns (Nigella sativa seeds oil can increase bone formation and may have anabolic effects on bone loss. This study was conducted to investigate the beneficial impacts of the oil of Black seeds on bone turnover in osteoporotic postmenopausal women. "nMaterials and methods: A placebo controlled pilot study was carried out on 15 postmenopausal osteoporotic women of 48-74 years old. In addition to Calcium-D supplements (2 tablets per day all participants were randomly received Ns extract (3ml, 0.05 ml/kg/day p .o. or placebo for 3 months. In all subjects hematological tests were performed and hepatic enzymes, BUN, Cr, Ca, P and plasma bone formation and resorption markers including osteocalcin, bone alkaline phosphatase (Bone-ALP and carboxy terminal cross linked telopeptide (CTX was determined before and after 12 weeks of treatment. "nResults: Twelve participants completed the entire 12 weeks study course of which 5 and 7 women were belonged to Ns and placebo groups respectively. Women in placebo group were significantly older than women in Ns group. There were not significant differences between BMIs, BMD results and plasma levels of bone marker in two groups at the baseline and plasma levels of bone markers between Ns and placebo group at the end of 12 weeks. Alterations from baseline in bone markers levels did not differ significantly between two groups. We did not observe any side effects due to Ns therapy. "nConclusion: In this pilot study similar to the previous trial, we failed to show beneficial impact of Ns extract administration for a short time on bone turnover so we don’t suggest it for medicinal application in the osteoporosis condition. Long time duration studies with larger sample size and usage of a more tolerable dosage forms of Black seeds oil should be emphasized for further clarification of its useful anabolic effects on bone metabolism.

  14. Bone Density, Turnover, and Estimated Strength in Postmenopausal Women Treated With Odanacatib

    DEFF Research Database (Denmark)

    Brixen, Kim; Chapurlat, Roland; Cheung, Angela M;

    2013-01-01

    bone compartments and estimated strength at the hip and spine.Design:This was a randomized, double-blind, 2-year trial.Setting:The study was conducted at a private or institutional practice.Participants:Participants included 214 postmenopausal women with low areal BMD.Intervention:The intervention...... included odanacatib 50 mg or placebo weekly.Main Outcome Measures:Changes in areal BMD by dual-energy x-ray absorptiometry (primary end point, 1 year areal BMD change at lumbar spine), bone turnover markers, volumetric BMD by quantitative computed tomography (QCT), and bone strength estimated by finite......-formation marker procollagen I N-terminal peptide initially decreased with odanacatib but by 2 years did not differ from placebo. After 6 months, odanacatib-treated women had greater increases in trabecular volumetric BMD and estimated compressive strength at the spine and integral and trabecular volumetric BMD...

  15. Bone turnover is adequately suppressed in osteoporotic patients treated with bisphosphonates in daily practice

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    Dijkmans Ben AC

    2011-07-01

    Full Text Available Abstract Background Monitoring osteoporosis therapy by measurement of bone turnover markers (BTMs might detect non-compliance in an earlier stage of anti-osteoporosis treatment and improve persistence. Methods BTMs were measured in two groups. The first group consisted of patients newly diagnosed with osteoporosis and starting treatment. We observed which proportion of patients had a decrease of serum levels of procollagen type 1 N-terminal propeptide (P1NP and C-terminal crosslinking telopeptide (CTX greater than the least significant change (LSC after 3 months of treatment. Secondly, we determined which proportion of patients who were treated with bisphosphonates for ≥ 3 months reached the biological goal of therapy, BTMs in the lower half of the normal premenopausal range. P1NP and CTX were also measured in a reference population of 34 healthy premenopausal women. Results In the first group 31 patients were included, in 25 patients (81% levels of both markers decreased with ≥ LSC, in the other patients a possible explanation was found. In the second group 95 patients were included, in 95% the serum P1NP levels and CTX levels were in the lower half of the premenopausal range. In 6 of the 7 patients with a level above the premenopausal range a possible explanation was found. Conclusion A decrease in bone turnover ≥ LSC can be observed in the majority of newly treated patients. In chronically treated patients, 95% have a bone turnover in the premenopausal range. In most patients with inadequate suppression of BTMs during bisphosphonate treatment, an explanation was found. Monitoring treatment effect with BTMs in daily practice is feasible, and might be an additive tool in improving therapy compliance.

  16. Bone turnover markers in medicamentous and physiological hyperprolactinemia in female rats

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    Radojković Danijela

    2014-01-01

    Full Text Available Background/Aim. There is a lack of data on the effects of prolactin on calcium metabolism and bone turnover in hyperprolactinemia of various origins. The aim of this study was to compare the influence of medicamentous and physiological hyperprolactinemia on bone turnover in female rats. Methods. Experimental animals (18 weeks old, Wistar female rats were divided as follows: the group P - 9 rats, 3 weeks pregnant; the group M3-10 rats that were intramuscularly administrated sulpirid (10 mg/kg twice daily for 3 weeks, the group M6 - 10 rats that were intramuscularly administrated with sulpirid (10 mg/kg twice daily for 6 weeks, and age matched nulliparous rats as the control group: 10 rats, 18-week-old (C1 and 7 rats, 24 weeks old (C2. Laboratory investigations included serum ionized calcium and phosphorus, urinary calcium and phosphorous excretion, osteocalcin and serum procollagen type 1 N-terminal propeptide (P1NP. Results. Experimental animals in the group P compared to the control group, displayed lower mean serum ionized calcium (0.5 ± 0.2 vs 1.12 ± 0.04 mmol/L; p < 0.001; higher mean serum phosphorus (2.42 ± 0.46 vs 2.05 ± 0.2 mmol/L; p < 0.05; increased urinary calcium (3.90 ± 0.46 vs 3.05 ± 0.58; p < 0.01 and significantly increased P1NP (489,22 ± 46,77 vs 361.9 ± 53,01 pg/mL; p < 0.001. Experimental animals in the group M3 had significantly decreased P1NP, compared to the control group. Prolongated medicamentous hyperprolactinemia (the group M6 induced increased serum ionized calcium (1.21 ± 0.03 vs 1.15 ± 0.02 mmol/L; p < 0.001; decreased serum phosphorus (1.70 ± 0.13 vs 1.89 ± 0.32 mmol/L; p < 0.001; decreased osteocalcin and P1NP. Conclusions. Physiological hyperprolactinemia does not have such harmful effect on bone metabolism as medicamentous hyperprolactinemia. Chronic medicamentous hyperprolactinemia produces lower serum levels of bone formation markers. Assessment of bone turnover markers in prolongated medicamentous

  17. Gender-Specific Changes in Bone Turnover and Skeletal Architecture in Igfbp-2-Null Mice

    OpenAIRE

    DeMambro, V. E.; Clemmons, D R; Horton, L. G.; Bouxsein, M. L.; Wood, T. L.; Beamer, W. G.; Canalis, E; C. J. Rosen

    2008-01-01

    IGF-binding protein-2 (IGFBP-2) is a 36-kDa protein that binds to the IGFs with high affinity. To determine its role in bone turnover, we compared Igfbp2−/− mice with Igfbp2+/+ colony controls. Igfbp2−/− males had shorter femurs and were heavier than controls but were not insulin resistant. Serum IGF-I levels in Igfbp2−/− mice were 10% higher than Igfbp2+/+ controls at 8 wk of age; in males, this was accompanied by a 3-fold increase in hepatic Igfbp3 and Igfbp5 mRNA transcripts compared with ...

  18. Serum bone turnover markers (PINP and ICTP) for the early detection of bone metastases in patients with prostate cancer : A longitudinal approach

    NARCIS (Netherlands)

    Koopmans, N.; de Jong, I. J.; van der Veer, E.; Breeuwsma, J.

    2007-01-01

    Purpose: An increase in bone turnover markers in patients with prostate cancer may predict bone metastases but it can also reflect the effects of androgen deprivation treatment. To assess the diagnostic efficacy of early detection of skeletal metastases we retrospectively performed serial measuremen

  19. Biochemical markers of bone turnover and their association with bone marrow lesions

    NARCIS (Netherlands)

    Hunter, D.J.; LaValley, M.; Li, J.; Bauer, D.C.; Nevitt, M.; Groot, J. de; Poole, R.; Eyre, D.; Guermazi, A.; Gale, D.; Totterman, S.; Felson, D.T.

    2008-01-01

    Introduction: Our objective was to determine whether markers of bone resorption and formation could serve as markers for the presence of bone marrow lesions (BMLs). Methods: We conducted an analysis of data from the Boston Osteoarthritis of the Knee Study (BOKS). Knee magnetic resonance images were

  20. Effects of dietary protein and glycaemic index on biomarkers of bone turnover in children

    DEFF Research Database (Denmark)

    Dalskov, Stine-Mathilde; Müller, Martha; Ritz, Christian;

    2014-01-01

    For decades, it has been debated whether high protein intake compromises bone mineralisation, but no long-term randomised trial has investigated this in children. In the family-based, randomised controlled trial DiOGenes (Diet, Obesity and Genes), we examined the effects of dietary protein and...... glycaemic index (GI) on biomarkers of bone turnover and height in children aged 5-18 years. In two study centres, families with overweight parents were randomly assigned to one of five ad libitum-energy, low-fat (25-30 % energy (E%)) diets for 6 months: low protein/low GI; low protein/high GI; high protein....../low GI; high protein/high GI; control. They received dietary instructions and were provided all foods for free. Children, who were eligible and willing to participate, were included in the study. In the present analyses, we included children with data on plasma osteocalcin or urinary N...

  1. Seasonal changes in vitamin D status and bone turnover in healthy Irish postmenopausal women

    DEFF Research Database (Denmark)

    Hill, T.R.; McCarthy, D.; Jakobsen, Jette;

    2007-01-01

    Objectives: To examine the effect of season on biochemical markers of bone turnover in 51-to 75-year-old Irish women and to investigate whether such changes are related to vitamin D status. Design: Longitudinal observational study. Setting: Cork, Ireland (52 degrees N). Subjects: 76 apparently...... healthy, free-living postmenopausal women (aged 51-75 years), not taking any medication and free from any condition likely to affect vitamin D status or calcium/bone metabolism. Results: Serum 25-hydroxyvitamin D [S-25(OH)D] showed a clear seasonal variation with significantly higher (p ... during late summer than late winter. Both urinary pyridinoline (Ur-Pyr) (p seasonal variation with lowest values during late-summer. Stratifying women into those with S-25(OH)D levels...

  2. Vitamin D Receptor gene polymorphism may predict response to vitamin D intake and bone turnover

    Directory of Open Access Journals (Sweden)

    G Ahangari

    2010-01-01

    Full Text Available "n  "n Background and the purpose of the study:The molecular and functional basis of the VDR polymorphisms is fundamental to appreciate their potential clinical implications. The rationale of this study was to determine the level of serum vitamin D response to vitamin D intake in different genotypes of VDR (FokI polymorphism and its effect on the bone turnover in postmenopausal women.  Methods:The subjects for the study were 312 pre and post-menopausal women aged between 20-75 year randomly selected from the participants of Iranian multicenter osteoporosis study. After an overnight fast, 4ml of peripheral blood was taken and centrifuged to separate serum for measurement of serum parathyroid hormone, 25 hydroxyvitamin D, osteocalcin and cross laps. The FokI polymorphism in exon 2 of the VDR gene was detected by the polymerase chain reaction-restriction fragment length polymorphism Results and major conclusion: FOKI genotype predicted serum cross laps after adjustment for age, menopausal status, serum vitamin D (p<0.001 but did not find significant prediction regarding serum osteocalcin (p=0.3.Also in this model FOKI genotype predicted serum vitamin D after adjustment for age, menopausal status, calcium and vitamin D intake (p<0.001.VDR gene polymorphism may modifies response to vitamin D intake and predicts bone turnover.   "n 

  3. Effects of resistance training and protein supplementation on bone turnover in young adult women

    Directory of Open Access Journals (Sweden)

    Sinning Wayne E

    2005-08-01

    Full Text Available Abstract Background The strength of aging bone depends on the balance between the resorption and formation phases of the remodeling process. The purpose of this study was to examine the interaction of two factors with the potential to exert opposing influences on bone turnover, resistance exercise training and high dietary protein intake. It was hypothesized that resistance training by young, healthy, untrained women with protein intakes near recommended levels (0.8 g·kg-1·d-1 would promote bone formation and/or inhibit bone resorption, and that subsequent supplementation to provide 2.4 g protein·kg-1·d-1 would reverse these effects. Methods Bone formation was assessed with serum bone-specific alkaline phosphatase (BAP and osteocalcin (OC, and bone resorption with urinary calcium and deoxypyridinoline (DPD. Biochemical, strength, anthropometric, dietary, and physical activity data were obtained from 24 healthy, untrained, eumenorrheic women (18–29y at baseline, after eight weeks of resistance training (3 d·wk-1, ~1 hr·d-1; 3 sets, 6–10 repetitions, 13 exercises, 75–85% maximum voluntary contraction, and after 12 weeks of resistance training and 10 days of protein/placebo supplementation. Subjects were randomized (double-blind to either a high protein (HP or training control (TC group and, during the final 10 days, consumed either enough purified whey protein to bring daily protein intake to 2.4 g·kg-1·d-1, or an equivalent dose of isoenergetic, carbohydrate placebo. Results Strength, lean tissue mass, and DPD increased significantly in both groups over time, while percent body fat and BAP decreased (repeated measures ANOVA, p ≤ 0.05, Bonferroni correction. No significant changes were observed for serum OC or urinary calcium, and no significant group (TC, HP × time (baseline, week 8, week 12 interactions emerged for any of the biochemical measures. Conclusion (1 Twelve weeks of high-intensity resistance training did not appear to

  4. High bone turnover is associated with low bone mass and spinal fracture in postmenopausal women

    DEFF Research Database (Denmark)

    Ravn, Pernille; Rix, M; Andreassen, H;

    1997-01-01

    -eight women had a lumbar spine bone mineral density (BMD) above 0.860 g/cm2, and 278 women had a BMD below 0.860 g/cm2. Spinal fracture was diagnosed from lateral spine X-ray studies and defined as at least 20% height reduction (wedge, compression, or endplate fracture) in at least one vertebra (T4-L4). Bone...

  5. Human stem cell osteoblastogenesis mediated by novel glycogen synthase kinase 3 inhibitors induces bone formation and a unique bone turnover biomarker profile in rats

    Energy Technology Data Exchange (ETDEWEB)

    Gilmour, Peter S., E-mail: Peter.Gilmour@astrazeneca.com [New Opportunities Innovative Medicines group, AstraZeneca R and D, Alderley Park, Cheshire SK10 4TF (United Kingdom); O' Shea, Patrick J.; Fagura, Malbinder [New Opportunities Innovative Medicines group, AstraZeneca R and D, Alderley Park, Cheshire SK10 4TF (United Kingdom); Pilling, James E. [Discovery Sciences, AstraZeneca R and D, Alderley Park, Cheshire SK10 4TF (United Kingdom); Sanganee, Hitesh [New Opportunities Innovative Medicines group, AstraZeneca R and D, Alderley Park, Cheshire SK10 4TF (United Kingdom); Wada, Hiroki [R and I IMed, AstraZeneca R and D, Molndal (Sweden); Courtney, Paul F. [DMPK, AstraZeneca R and D, Alderley Park, Cheshire SK10 4TF (United Kingdom); Kavanagh, Stefan; Hall, Peter A. [Safety Assessment, AstraZeneca R and D, Alderley Park, Cheshire SK10 4TF (United Kingdom); Escott, K. Jane [New Opportunities Innovative Medicines group, AstraZeneca R and D, Alderley Park, Cheshire SK10 4TF (United Kingdom)

    2013-10-15

    Wnt activation by inhibiting glycogen synthase kinase 3 (GSK-3) causes bone anabolism in rodents making GSK-3 a potential therapeutic target for osteoporotic and osteolytic metastatic bone disease. To understand the wnt pathway related to human disease translation, the ability of 3 potent inhibitors of GSK-3 (AZD2858, AR79, AZ13282107) to 1) drive osteoblast differentiation and mineralisation using human adipose-derived stem cells (hADSC) in vitro; and 2) stimulate rat bone formation in vivo was investigated. Bone anabolism/resorption was determined using clinically relevant serum biomarkers as indicators of bone turnover and bone formation assessed in femurs by histopathology and pQCT/μCT imaging. GSK-3 inhibitors caused β-catenin stabilisation in human and rat mesenchymal stem cells, stimulated hADSC commitment towards osteoblasts and osteogenic mineralisation in vitro. AZD2858 produced time-dependent changes in serum bone turnover biomarkers and increased bone mass over 28 days exposure in rats. After 7 days, AZD2858, AR79 or AZ13282107 exposure increased the bone formation biomarker P1NP, and reduced the resorption biomarker TRAcP-5b, indicating increased bone anabolism and reduced resorption in rats. This biomarker profile was differentiated from anabolic agent PTH{sub 1–34} or the anti-resorptive Alendronate-induced changes. Increased bone formation in cortical and cancellous bone as assessed by femur histopathology supported biomarker changes. 14 day AR79 treatment increased bone mineral density and trabecular thickness, and decreased trabecular number and connectivity assessed by pQCT/μCT. GSK-3 inhibition caused hADSC osteoblastogenesis and mineralisation in vitro. Increased femur bone mass associated with changes in bone turnover biomarkers confirmed in vivo bone formation and indicated uncoupling of bone formation and resorption. - Highlights: • Wnt modulation with 3 novel GSK-3 inhibitors alters bone growth. • Human stem cell osteoblastogenesis

  6. Human stem cell osteoblastogenesis mediated by novel glycogen synthase kinase 3 inhibitors induces bone formation and a unique bone turnover biomarker profile in rats

    International Nuclear Information System (INIS)

    Wnt activation by inhibiting glycogen synthase kinase 3 (GSK-3) causes bone anabolism in rodents making GSK-3 a potential therapeutic target for osteoporotic and osteolytic metastatic bone disease. To understand the wnt pathway related to human disease translation, the ability of 3 potent inhibitors of GSK-3 (AZD2858, AR79, AZ13282107) to 1) drive osteoblast differentiation and mineralisation using human adipose-derived stem cells (hADSC) in vitro; and 2) stimulate rat bone formation in vivo was investigated. Bone anabolism/resorption was determined using clinically relevant serum biomarkers as indicators of bone turnover and bone formation assessed in femurs by histopathology and pQCT/μCT imaging. GSK-3 inhibitors caused β-catenin stabilisation in human and rat mesenchymal stem cells, stimulated hADSC commitment towards osteoblasts and osteogenic mineralisation in vitro. AZD2858 produced time-dependent changes in serum bone turnover biomarkers and increased bone mass over 28 days exposure in rats. After 7 days, AZD2858, AR79 or AZ13282107 exposure increased the bone formation biomarker P1NP, and reduced the resorption biomarker TRAcP-5b, indicating increased bone anabolism and reduced resorption in rats. This biomarker profile was differentiated from anabolic agent PTH1–34 or the anti-resorptive Alendronate-induced changes. Increased bone formation in cortical and cancellous bone as assessed by femur histopathology supported biomarker changes. 14 day AR79 treatment increased bone mineral density and trabecular thickness, and decreased trabecular number and connectivity assessed by pQCT/μCT. GSK-3 inhibition caused hADSC osteoblastogenesis and mineralisation in vitro. Increased femur bone mass associated with changes in bone turnover biomarkers confirmed in vivo bone formation and indicated uncoupling of bone formation and resorption. - Highlights: • Wnt modulation with 3 novel GSK-3 inhibitors alters bone growth. • Human stem cell osteoblastogenesis and

  7. Effects of growth hormone and low dose estrogen on bone growth and turnover in long bones of hypophysectomized rats

    Science.gov (United States)

    Kidder, L. S.; Schmidt, I. U.; Evans, G. L.; Turner, R. T.

    1997-01-01

    Pituitary hormones are recognized as critical to longitudinal growth, but their role in the radial growth of bone and in maintaining cancellous bone balance are less clear. This investigation examines the histomorphometric effects of hypophysectomy (Hx) and ovariectomy (OVX) and the subsequent replacement of growth hormone (GH) and estrogen (E), in order to determine the effects and possible interactions between these two hormones on cortical and cancellous bone growth and turnover. The replacement of estrogen is of interest since Hx results in both pituitary and gonadal hormone insufficiencies, with the latter being caused by the Hx-associated reduction in follicle stimulating hormone (FSH). All hypophysectomized animals received daily supplements of hydrocortisone (500 microg/kg) and L-thyroxine (10 microg/kg), whereas intact animals received daily saline injections. One week following surgery, hypophysectomized animals received either daily injections of low-dose 17 beta-estradiol (4.8 microg/kg s.c.), 3 X/d recombinant human GH (2 U/kg s.c.), both, or saline for a period of two weeks. Flurochromes were administered at weekly intervals to label bone matrix undergoing mineralization. Whereas Hx resulted in reductions in body weight, uterine weight, and tibial length, OVX significantly increased body weight and tibial length, while reducing uterine weight. The combination of OVX and Hx resulted in values similar to Hx alone. Treatment with GH normalized body weight and bone length, while not affecting uterine weight in hypophysectomized animals. Estrogen increased uterine weight, while not impacting longitudinal bone growth and reduced body weight. Hypophysectomy diminished tibial cortical bone area through reductions in both mineral appositional rate (MAR) and bone formation rate (BFR). While E had no effect, GH increased both MAR and BFR, though not to sham-operated (control) levels. Hypophysectomy reduced proximal tibial trabecular number and cancellous bone

  8. Bone turnover and metabolism in patients with early multiple sclerosis and prevalent bone mass deficit: a population-based case-control study.

    Directory of Open Access Journals (Sweden)

    Stine Marit Moen

    Full Text Available BACKGROUND: Low bone mass is prevalent in ambulatory multiple sclerosis (MS patients even shortly after clinical onset. The mechanism is not known, but could involve shared etiological risk factors between MS and low bone mass such as hypovitaminosis D operating before disease onset, or increased bone loss after disease onset. The aim of this study was to explore the mechanism of the low bone mass in early-stage MS patients. METHODOLOGY/PRINCIPAL FINDINGS: We performed a population-based case-control study comparing bone turnover (cross-linked N-terminal telopeptide of type 1 collagen; NTX, bone alkaline phosphatase; bALP, metabolism (25-hydroxy- and 1, 25-dihydroxyvitamin D, calcium, phosphate, and parathyroid hormone, and relevant lifestyle factors in 99 patients newly diagnosed with clinically isolated syndrome (CIS or MS, and in 159 age, sex, and ethnicity matched controls. After adjustment for possible confounders, there were no significant differences in NTX (mean 3.3; 95% CI -6.9, 13.5; p = 0.519, bALP (mean 1.6; 95% CI -0.2, 3.5; p = 0.081, or in any of the parameters related to bone metabolism in patients compared to controls. The markers of bone turnover and metabolism were not significantly correlated with bone mass density, or associated with the presence of osteoporosis or osteopenia within or between the patient and control groups. Intake of vitamin D and calcium, reported UV exposure, and physical activity did not differ significantly. CONCLUSIONS/SIGNIFICANCE: Bone turnover and metabolism did not differ significantly in CIS and MS patients with prevalent low bone mass compared to controls. These findings indicate that the bone deficit in patients newly diagnosed with MS and CIS is not caused by recent acceleration of bone loss, and are compatible with shared etiological factors between MS and low bone mass.

  9. Relationship between Mandibular BMD and Bone Turnover Markers in Osteoporosis Diagnosis

    Directory of Open Access Journals (Sweden)

    SM Eshaghi

    2008-11-01

    Full Text Available "nBackground: The purpose of the present study was to determine mandible bone mineral density and evaluate its correlation with central BMD and bone turnover."nMethods: Two hundred and seven postmenopausal women were enrolled in this cross-sectional study. After receiving the tes­timonials, questionnaires were completed and physical exams were done. For all participants central BMD was measured through DXA method. In each women periapical radiography performed in two regions of mandible. The plain x-ray films were scanned using a standard film digitizer and standardized in size and intensity using a calibration step wedge phantom. The phantom was placed upper site in film cover. After the film digitized, the developed Matlab software was used to image proc­essing."nResults: Mean age and body mass index of participants were 54.6±6.3 years and 28.57±4.9 kg/m2 respectively. Prevalence of osteoporosis and osteopenia in one of regions in central DXA were 17.4% and 48.2% respectively. There was strong cor­relation between mandible and total femur BMD (P= 0.001, r= 0.80.In osteoporotic patients bone loss in mandible BMD was more than central DXA (P= 0.02."nConclusion: The main advantage of the proposed mandible BMD is to help clinicians make more accurate evaluation of Bone loss. Based on developed the suggested system a routine dental X-ray could be used to screen for bone loss.

  10. Role of NADPH oxidases and reactive oxygen species in regulation of bone turnover and the skeletal toxicity of alcohol

    Science.gov (United States)

    Recent studies with genetically modified mice and dietary antioxidants have suggested an important role for superoxide derived from NADPH oxidase (NOX) enzymes and other reactive oxygen species (ROS) such as hydrogen peroxide in regulation of normal bone turnover during development and also in the r...

  11. BONE TURNOVER AND MINERAL DENSITY OF THE LUMBAR VERTEBRAE IN WOMEN WITH PRIMARY BILIARY CIRRHOSIS BEFORE AND AFTER ORTHOTOPIC LIVER TRANSPLANTATION

    Directory of Open Access Journals (Sweden)

    I. A. Pronchenko

    2013-01-01

    Full Text Available Aim. To elucidate the role of cholestasis and menopausal status in the development of osteoporosis in women with primary biliary cirrhosis (PBC before and after orthotopic liver transplantation (OLT. Methods and re- sults. There were fulfilled 74 estimations of biochemical markers of bone metabolism, estrogen (E2, parathy- roid hormone (PTH endogenous secretion so as mineral content of lumbar vertebras in 21 women with PBC (10 women before and 17 in different terms after OLT. Bone turnover disturbances were characterized by delay of bone formation associated with hyperbilirubinaemia before OLT while increased bone turnover following OLT. Bone resorption markers correlated inversely with E2 in postmenopausal women and positively with PTH in premenopausal women. Conclusion. Bone wastes degree depended on hard and duration of disease before OLT so as menopausal status after OLT. In postmenopausal women bone wastes were associated with degree of endogenous E2 decreasing, increased bone turnover, and graft dysfunction. 

  12. Effect of phylloquinone supplementation on biochemical markers of vitamin K status and bone turnover in postmenopausal women

    DEFF Research Database (Denmark)

    Bugel, Susanne; Sorensen, A. Dorthe; Hels, Ole;

    2007-01-01

    While current intakes of phylloquinone (vitamin K-1) in many populations are believed to be sufficient to maintain normal blood coagulation, these may be insufficient to cover the requirements for optimal bone metabolism. Therefore, the objective of the present study was to investigate the effect...... of increasing phylloquinone intakes above the usual dietary intake for 6 weeks on biochemical markers of vitamin K status and bone turnover in postmenopausal women. Thirty-one postmenopausal women completed this 3 X 6-week randomised cross-over study, in which volunteers were supplemented with 0 (placebo), 200......, pyridinoline and deoxypyridinoline) and urinary gamma-carboxyglutarnate were unaffected by phylloquinone supplementation. In conclusion, while daily supplementation with 200 and 500 mu g phylloquinone/d for 6 weeks increased vitamin K status in postmenopausal women, it had no effect on bone turnover....

  13. Changes in bone turnover markers and menstrual function after short-term oral DHEA in young women with anorexia nervosa.

    Science.gov (United States)

    Gordon, C M; Grace, E; Emans, S J; Goodman, E; Crawford, M H; Leboff, M S

    1999-01-01

    Bone loss is a serious consequence of anorexia nervosa (AN). Subnormal levels of serum dehydroepiandrosterone (DHEA) are seen in patients with AN and may be causally linked to their low bone density. We hypothesized that oral DHEA would decrease markers of bone resorption (urinary N-telopeptides [NTx]), and increase markers of bone formation (serum bone-specific alkaline phosphatase and osteocalcin [OC]). Fifteen young women (age 15-22 years) with AN were enrolled in a 3-month, randomized, double-blinded trial of 50, 100, or 200 mg of daily micronized DHEA. Blood and urinary levels of adrenal and gonadal steroids and bone turnover markers were measured. No adverse clinical side effects of DHEA were noted, and a 50 mg daily dose restored physiologic hormonal levels. At 3 months, NTx levels had decreased significantly in both the 50 mg (p = 0.018) and the 200 mg (p = 0.016) subgroups. OC levels simultaneously increased within treatment groups over time (p = 0.002). Eight out of 15 (53%) subjects had at least one menstrual cycle while on therapy. Short-term DHEA was well-tolerated and appears to normalize bone turnover in young women with AN. Resumption of menses in over half of subjects suggests that DHEA therapy may also lead to estradiol levels sufficient to stimulate the endometrium in this group of patients. PMID:9893076

  14. Changes in bone turnover and bone loss in HIV-infected patients changing treatment to tenofovir-emtricitabine or abacavir-lamivudine.

    Directory of Open Access Journals (Sweden)

    Hila Haskelberg

    Full Text Available BACKGROUND: Those receiving tenofovir/emtricitabine (TDF-FTC had greater bone loss compared with abacavir/lamivudine (ABC-3TC in a randomized simplification trial (STEAL study. Previous studies associated increased bone turnover and bone loss with initiation of antiretroviral treatment, however it is unclear whether change in bone mineral density (BMD was a result of specific drugs, from immune reconstitution or from suppression of HIV replication. This analysis determined predictors of BMD change in the hip and spine by dual-energy x-ray absorptiometry in virologically suppressed participants through week 96. METHODOLOGY/PRINCIPAL FINDINGS: Bone turnover markers (BTMS tested were: formation [bone alkaline phosphatase, procollagen type 1 N-terminal propeptide (P1NP]; resorption (C-terminal cross-linking telopeptide of type 1 collagen [CTx]; and bone cytokine-signalling (osteoprotegerin, RANK ligand. Independent predictors of BMD change were determined using forward, stepwise, linear regression. BTM changes and fracture risk (FRAX® at week 96 were compared by t-test. Baseline characteristics (n = 301 were: 98% male, mean age 45 years, current protease-inhibitor (PI 23%, tenofovir/abacavir-naïve 52%. Independent baseline predictors of greater hip and spine bone loss were TDF-FTC randomisation (p ≤ 0.013, lower fat mass (p-trend ≤ 0.009, lower P1NP (p = 0.015, and higher hip T score/spine BMD (p-trend ≤ 0.006. Baseline PI use was associated with greater spine bone loss (p = 0.004. TDF-FTC increased P1NP and CTx through Wk96 (p<0.01. Early changes in BTM did not predict bone loss at week 96. No significant between-group difference was found in fracture risk. CONCLUSIONS/SIGNIFICANCE: Tenofovir/emtricitabine treatment, lower bone formation and lower fat mass predicted subsequent bone loss. There was no association between TDF-FTC and fracture risk.

  15. Vitamin D status, dietary intake, and bone turnover in female Soldiers during military training: a longitudinal study

    Directory of Open Access Journals (Sweden)

    Lutz Laura J

    2012-08-01

    Full Text Available Abstract Background Vitamin D is an essential nutrient for maintaining bone health, to include protecting against stress fracture during periods of rapid bone turnover. The objective of this longitudinal, observational study was to assess vitamin D status, biomarkers of bone turnover, and vitamin D and calcium intake in female Soldiers (n = 91 during US Army basic combat training (BCT. Methods Anthropometric, biological and dietary intake data were collected at wk 0, 3, 6, and 9 of the 10 wk BCT course. Mixed models repeated measures ANOVAs were used to assess main effects of time, race, and time-by-race interactions. Results White volunteers experienced a decrease in serum 25(OHD levels, whereas non-white volunteers experienced an increase during BCT. However, serum 25(OHD levels were lower in non-whites than whites at all timepoints (P-interaction  Conclusions These findings demonstrate that female Soldiers experience dynamic changes in vitamin D status coupled with increased bone turnover and potentially inadequate vitamin D and calcium intake during military training.

  16. Effect of Intravenous Glucose Tolerance Test on Bone Turnover Markers in Adults with Normal Glucose Tolerance

    Science.gov (United States)

    Xiang, Shou-Kui; Wan, Jing-Bo; Jiang, Xiao-Hong; Zhu, Yong-Hua; Ma, Jin-Hong; Hua, Fei

    2016-01-01

    Background It is well known that enteral nutrients result in acute suppression of bone turnover markers (BTMs), and incretin hormones are believed to play a significant role in this physiological skeletal response. However, there is limited research exploring the impact of parenteral nutrients on BTMs. Our aim was to assess the influence of intravenous glucose on BTMs in adults with normal glucose tolerance (NGT). Material/Methods We conducted 1-h intravenous glucose tolerance test (IVGTT) in 24 subjects with NGT. Blood samples were collected before and 5, 10, 15, 20, 30, 60 min after administration of glucose, then serum levels of bone formation marker procollagen type I N-terminal propeptide (P1NP) and resorption marker C-terminal cross-linking telopeptides of collagen type I (CTX) were measured. Results During IVGTT, the fasting CTX level fell gradually and reached a nadir of 80.4% of the basal value at 60 min. Conversely, the fasting P1NP level decreased mildly and reached a nadir of 90.6% of the basal value at 15 min, then gradually increased and reached 96.6% at 60 min. The CTX-to-P1NP ratio increased slightly and reached a peak of 104.3% of the basal value at 10 min, then fell gradually and reached a nadir of 83% at 60 min. Conclusions Our study indicates that intravenous glucose results in an acute suppression of BTMs in the absence of incretin hormones. The mechanism responsible for this needs further investigation. PMID:27447783

  17. Adequate dietary vitamin D and calcium are both required to reduce bone turnover and increased bone mineral volume.

    Science.gov (United States)

    Lee, Alice M C; Sawyer, Rebecca K; Moore, Alison J; Morris, Howard A; O'Loughlin, Peter D; Anderson, Paul H

    2014-10-01

    Clinical studies indicate that the combination of vitamin D and dietary calcium supplementation is more effective for reducing fracture risk than either supplement alone. Our previous dietary studies demonstrated that an adequate serum 25-hydroxyvitamin D3 (25D) of 80nmol/L or more reduces bone RANKL expression, osteoclastogenesis and maintains the optimal levels of trabecular bone volume (BV/TV%) in young rats. The important clinical question of the interaction between vitamin D status, dietary calcium intake and age remains unclear. Hence, 9 month-old female Sprague-Dawley rats (n=5-6/group) were pair-fed a semi-synthetic diet containing varying levels of vitamin D (0, 2, 12 or 20IU/day) and dietary calcium (0.1% or 1%) for 6 months. At 15 months of age, animals were killed, for biochemical and skeletal analyses. While changes to serum 25D were determined by both dietary vitamin D and calcium levels, changes to serum 1,25-dihydroxyvitamin D3 (1,25D) were consistently raised in animals fed 0.1% Ca regardless of dietary vitamin D or vitamin D status. Importantly, serum cross-laps levels were significantly increased in animals fed 0.1% Ca only when combined with 0 or 2 IUD/day of vitamin D, suggesting a contribution of both dietary calcium and vitamin D in determining bone resorption activity. Serum 25(OH)D3 levels were positively correlated with both femoral mid-diaphyseal cortical bone volume (R(2)=0.24, PTV% (R(2)=0.23, Pnegative determinant of CBV (R(2)=0.24, PTV% levels. These data support clinical data that reduced bone resorption and increased bone volume can only be achieved with adequate 25D levels in combination with high dietary calcium and low serum 1,25D levels. This article is part of a Special Issue entitled '16th Vitamin D Workshop'. PMID:24309068

  18. Is Gastrectomy-Induced High Turnover of Bone with Hyperosteoidosis and Increase of Mineralization a Typical Osteomalacia?

    OpenAIRE

    Takashi Ueyama; Yuta Yamamoto; Kazuki Ueda; Aiji Yajima; Yoshimasa Maeda; Yasunobu Yamashita; Takao Ito; Yoshihiro Tsuruo; Masao Ichinose

    2013-01-01

    Gastrectomy (GX) is thought to result in osteomalacia due to deficiencies in Vitamin D and Ca. Using a GX rat model, we showed that GX induced high turnover of bone with hyperosteoidosis, prominent increase of mineralization and increased mRNA expression of both osteoclast-derived tartrate-resistant acid phosphatase 5b and osteocalcin. The increased 1, 25(OH)2D3 level and unchanged PTH and calcitonin levels suggested that conventional bone and Ca metabolic pathways were not involved or change...

  19. Associations between serum 25-hydroxyvitamin D and bone turnover markers in a population based sample of German children

    OpenAIRE

    Thiering, E.; Brüske, I.; Kratzsch, J.; Hofbauer, L C; Berdel, D; von Berg, A.; Lehmann, I.; Hoffmann, B.; Bauer, C. P.; Koletzko, S.; Heinrich, J.

    2015-01-01

    Severe vitamin D deficiency is known to cause rickets, however epidemiological studies and RCTs did not reveal conclusive associations for other parameters of bone health. In our study, we aimed to investigate the association between serum levels of 25(OH) vitamin D and bone turnover markers in a population-based sample of children. 25(OH)D, calcium (Ca), osteocalcin (OC), and β-Crosslaps (β-CTx) were measured in 2798 ten-year-old children from the German birth cohorts GINIplus and LISAplus. ...

  20. Bone turnover in wild type and pleiotrophin-transgenic mice housed for three months in the International Space Station (ISS).

    Science.gov (United States)

    Tavella, Sara; Ruggiu, Alessandra; Giuliani, Alessandra; Brun, Francesco; Canciani, Barbara; Manescu, Adrian; Marozzi, Katia; Cilli, Michele; Costa, Delfina; Liu, Yi; Piccardi, Federica; Tasso, Roberta; Tromba, Giuliana; Rustichelli, Franco; Cancedda, Ranieri

    2012-01-01

    Bone is a complex dynamic tissue undergoing a continuous remodeling process. Gravity is a physical force playing a role in the remodeling and contributing to the maintenance of bone integrity. This article reports an investigation on the alterations of the bone microarchitecture that occurred in wild type (Wt) and pleiotrophin-transgenic (PTN-Tg) mice exposed to a near-zero gravity on the International Space Station (ISS) during the Mice Drawer System (MDS) mission, to date, the longest mice permanence (91 days) in space. The transgenic mouse strain over-expressing pleiotrophin (PTN) in bone was selected because of the PTN positive effects on bone turnover. Wt and PTN-Tg control animals were maintained on Earth either in a MDS payload or in a standard vivarium cage. This study revealed a bone loss during spaceflight in the weight-bearing bones of both strains. For both Tg and Wt a decrease of the trabecular number as well as an increase of the mean trabecular separation was observed after flight, whereas trabecular thickness did not show any significant change. Non weight-bearing bones were not affected. The PTN-Tg mice exposed to normal gravity presented a poorer trabecular organization than Wt mice, but interestingly, the expression of the PTN transgene during the flight resulted in some protection against microgravity's negative effects. Moreover, osteocytes of the Wt mice, but not of Tg mice, acquired a round shape, thus showing for the first time osteocyte space-related morphological alterations in vivo. The analysis of specific bone formation and resorption marker expression suggested that the microgravity-induced bone loss was due to both an increased bone resorption and a decreased bone deposition. Apparently, the PTN transgene protection was the result of a higher osteoblast activity in the flight mice.

  1. Measurement of bone mineral density using DEXA and biochemical markers of bone turnover in 5-year survivors after orthotopic liver transplantation

    International Nuclear Information System (INIS)

    Purpose: To observe bone loss and bone metabolism status in 5-year survivors after orthotopic liver transplantation (OLT). Methods: Measurement of bone mineral density (BMD) of the lumbar spine (L2∼L4) and femoral neck using dual energy X-ray absorptiometry (DEXA) and analysis of biochemical markers of bone turnover, such as ostecalcin (OSC), bone alkaline phosphatase (BAP), carboxy-terminal propeptide of type I procollagen (PICP), carboxy-terminal cross-linked telo-peptide of type I collagen (ICTP), PTH and 25-hydroxy-vitamin D (25-OH-D). These markers were measured in 31 5-year survivors after OLT, 34 patients with chronic liver failure (CLF) before OLT and 38 normal subjects. Results: Age-matched Z-score of BMD (Z-score) at L2∼L4 was significantly higher in 5-year survivors than that in patients with CLF before OLT. Incidence of osteoporosis (Z-score<-2.0) in 5-year survivors was significantly lower than that in patients with CLF before OLT. Although serum concentrations of bone formation and bone resorption markers in 5-year survivors were high than those of normal subjects, as compared to patients with CLF before OLT, serum OSC was increased, serum ICTP and BAP were reduced, serum PICP was unchanged. Serum PTH and 25-OH-D level was normal. Conclusions: In 5-year survivors following liver transplantation there was a reduction in bone loss and incidence of osteoporosis and an improvement of bone metabolism

  2. Associations between serum 25-hydroxyvitamin D and bone turnover markers in a population based sample of German children.

    Science.gov (United States)

    Thiering, E; Brüske, I; Kratzsch, J; Hofbauer, L C; Berdel, D; von Berg, A; Lehmann, I; Hoffmann, B; Bauer, C P; Koletzko, S; Heinrich, J

    2015-01-01

    Severe vitamin D deficiency is known to cause rickets, however epidemiological studies and RCTs did not reveal conclusive associations for other parameters of bone health. In our study, we aimed to investigate the association between serum levels of 25(OH) vitamin D and bone turnover markers in a population-based sample of children. 25(OH)D, calcium (Ca), osteocalcin (OC), and β-Crosslaps (β-CTx) were measured in 2798 ten-year-old children from the German birth cohorts GINIplus and LISAplus. Linear regression was used to determine the association between bone turnover markers and 25(OH)D levels. 25(OH)D, OC, and β-CTx showed a clear seasonal variation. A 10 nmol/l increase in 25(OH)D was significantly associated with a 10.5 ng/l decrease (p < 0.001) in β-CTx after adjustment for design, sex, fasting status, time of blood drawn, BMI, growth rate, and detectable testosterone/estradiol. For OC alone no significant association with 25(OH)D was observed, whereas the β-CTx-to-OC ratio was inversely associated with 25(OH)D (-1.7% change, p < 0.001). When stratifying the analyses by serum calcium levels, associations were stronger in children with Ca levels below the median. This study in school-aged children showed a seasonal variation of 25(OH)D and the bone turnover markers OC and β-CTx. Furthermore a negative association between 25(OH)D and the bone resorption marker β-CTx was observed. PMID:26667774

  3. Relationship among panoramic radiography findings, biochemical markers of bone turnover and hip bone mineral density in the diagnosis of postmenopausal osteoporosis

    International Nuclear Information System (INIS)

    Recent investigations have shown that panoramic radiography might be a useful tool in the early diagnosis of osteoporosis. In addition, bone turnover biochemical marker might be valuable in predicting osteoporosis and fracture risks in the elderly, especially in post-menopausal women. The aim of the present study was to evaluate the relationship among the radio morphometric indices of the mandible, biochemical markers of the bone turnover and hip bone mineral density in a group of post-menopausal women. Patients and Methods: Evaluations of mandibular cortical width, mandibular cortical index, panoramic index and alveolar crest resorption ration (M/M ration) were carried out on panoramic radiographs of 140 post-menopausal women with an age range of 44-82 years. Hip bone mineral density was measured by dual-energy X-ray absorptiometry method. Bone mineral density values were divided into three groups of normal (T score>-1.0), Osteopenic (T score, -2.5 to -1.0) and Osteoporotic (T score<-2.5). Serum alkaline phosphatase and 25(OH) D3 were measured. Results: A decrease in mandibular cortical width by 1 mm increases the likelihood of osteopenia or osteoporosis up to 40%, having taken into consideration the effect of menopause duration. A 1 mm decrease in mandibular cortical width increased the likelihood of moderate or severe erosion of the lower cortex of the mandible up to 28% by taking age into consideration. The results did not demonstrate a statistically significant relationship between bone turnover markers and mandibular radio morphometric indices. Conclusion: Panoramic radiography gives sufficient information to make an early diagnosis regarding osteoporosis in post-menopausal women. Panoramic radiographs may be valuable in the prevention of osteoporotic fractures in elderly women.

  4. Effects of Low-Dose Testosterone Undecanoate Treatment on Bone Mineral Density and Bone Turnover Markers in Elderly Male Osteoporosis with Low Serum Testosterone

    OpenAIRE

    Yan-Jiao Wang; Jun-Kun Zhan; Wu Huang; Yi Wang; Yuan Liu; Sha Wang; Pan Tan; Zhi-Yong Tang; You-Shuo Liu

    2013-01-01

    This prospective 2-year, single-center, randomized, placebo-controlled, open-label clinical trial was performed to evaluate the efficacy of low-dose testosterone undecanoate (TU) treatment on bone mineral density (BMD) and biochemical markers of bone turnover in elderly male osteoporosis with low serum testosterone. A total of 186 elderly male osteoporosis patients with low serum testosterone were randomized into three groups: low-dose TU (20 mg, per day), standard-dose TU (40 mg, per day), a...

  5. Clinical benefits of biochemical markers of bone turnover in Egyptian children with chronic liver diseases

    Institute of Scientific and Technical Information of China (English)

    Karam A Mahdy; Hanaa H Ahmed; Fathia Mannaa; Azza Abdel-Shaheed

    2007-01-01

    AIM: To investigate the association between serum insulin-like growth factor 1 (IGF-1), osteocalcin, and parathyroid hormone (PTH) levels with the etiology and clinical condition of patients with chronic liver disease.METHODS: Eighty children with hepatocellular damage were divided into 3 groups according to the etiology of disease infection: bilharziasis (9 patients), hepatitis B virus (HBV, 12 patients) and hepatitis C virus (HCV, 29 patients). The Child score index was found as A in 24 patients, B in 22 patients, C in 4 patients. Thirty healthy children served as control group. HBsAg, HBcAbIgM,HBcAbIgG, and anti-HCV were detected using ELISA technique. HCV-RNA was measured by reverse transcription polymerase chain reaction (RT-PCR). Antibilharzial antibodies were detected by indirect haemagglutination test. Liver function tests were performed using autoanalyser. Serum IGF-1, osteocalcin and PTH levels were measured by ELISA technique. Abdominal ultrasonography was also conducted.RESULTS: Serum IGF-1 level was significantly lower in all patient groups with liver diseases, while serum osteocalcin and PTH levels were significantly elevated in patients with HBV and HCV infections compared with the control group. Serum osteocalcin and PTH concentrations were measured with the severity of liver disease from Child A to C. Child A patients unexpectedly showed significantly reduced IGF-1 levels in comparison to patients staged as Child B or C. Serum osteocalcin level was negatively correlated with albumin (14.7 ± 0.54 vs 3.6± 0.10, P < 0.05), while that for PTH was positively correlated with total protein (70.1 ± 2.17 vs 6.7 + 0.10,P < 0.05) in patients with HCV infection.CONCLUSION: Low serum IGF-1 level seems to play a critical role in the bone loss in patients with chronic liver disease. Elevated biochemical markers of bone remodeling suggest high-turnover in patients with viral infection and reflect severity of the clinical stage.

  6. Genistein supplementation increases bone turnover but does not prevent alcohol-induced bone loss in male mice

    Science.gov (United States)

    Chronic alcohol consumption results in bone loss through increased bone resorption and decreased bone formation. These effects can be reversed by estradiol (E2) supplementation. Soy diets are suggested to have protective effects on bone loss in men and women, as a result of the presence of soy prote...

  7. Bone turnover markers are correlated with total skeletal uptake of 99mTc-methylene diphosphonate (99mTc-MDP)

    International Nuclear Information System (INIS)

    Skeletal uptake of 99mTc labelled methylene diphosphonate (99mTc-MDP) is used for producing images of pathological bone uptake due to its incorporation to the sites of active bone turnover. This study was done to validate bone turnover markers using total skeletal uptake (TSU) of 99mTc-MDP. 22 postmenopausal women (52–80 years) volunteered to participate. Scintigraphy was performed by injecting 520 MBq of 99mTc-MDP and taking whole body images after 3 minutes, and 5 hours. TSU was calculated from these two images by taking into account the urinary loss and soft tissue uptake. Bone turnover markers used were bone specific alkaline phosphatase (S-Bone ALP), three different assays for serum osteocalcin (OC), tartrate resistant acid phosphatase 5b (S-TRACP5b), serum C-terminal cross-linked telopeptides of type I collagen (S-CTX-I) and three assays for urinary osteocalcin (U-OC). The median TSU of 99mTc-MDP was 23% of the administered activity. All bone turnover markers were significantly correlated with TSU with r-values from 0.52 (p = 0.013) to 0.90 (p < 0.001). The two resorption markers had numerically higher correlations (S-TRACP5b r = 0.90, S-CTX-I r = 0.80) than the formation markers (S-Total OC r = 0.72, S-Bone ALP r = 0.66), but the difference was not statistically significant. TSU did not correlate with age, weight, body mass index or bone mineral density. In conclusion, bone turnover markers are strongly correlated with total skeletal uptake of 99mTc-MDP. There were no significant differences in correlations for bone formation and resorption markers. This should be due to the coupling between formation and resorption

  8. A influência da deficiência estrogênica no processo de remodelação e reparação óssea Effect of estrogen deficiency on bone turnover and bone repair

    Directory of Open Access Journals (Sweden)

    Susana Ungaro Amadei

    2006-02-01

    cellular activity and several studies focus on the factors able to modulate the bone functions. The increase of bone research is, in part, due to the establishment of osteoporosis as a healthy problem common in elderly. Osteoporosis is one of the most important osteopathy, characterized by the bone mass reduction, resulted from disequilibrium between bone resorption and bone formation. OBJECTIVE: Based on the relationship between estrogen and bone metabolism, the aim of this study is present a review of literature about the principal aspects of bone turnover and bone repair associated to estrogen deficiency. Bone turnover: Bone tissue is in continuous turnover, however, changes in this process can result in some disorders, such as osteoporosis. Bone repair: Involves a sequence of biological events. It is affected by local and external factors and regulated by interaction of several mechanisms, like bone turnover. Estrogen deficiency and bone metabolism: The capacity to repair has been associated to changes in bone turnover and repair. DISCUSSION: It is not known which bone repair stage is modified: the bone formation, the mineralization or the resorption stage. CONCLUSION: The pathophysiology of bone changes caused by estrogen deficiency are not completely clear, so, new studies are still necessary.

  9. Is gastrectomy-induced high turnover of bone with hyperosteoidosis and increase of mineralization a typical osteomalacia?

    Directory of Open Access Journals (Sweden)

    Takashi Ueyama

    Full Text Available Gastrectomy (GX is thought to result in osteomalacia due to deficiencies in Vitamin D and Ca. Using a GX rat model, we showed that GX induced high turnover of bone with hyperosteoidosis, prominent increase of mineralization and increased mRNA expression of both osteoclast-derived tartrate-resistant acid phosphatase 5b and osteocalcin. The increased 1, 25(OH2D3 level and unchanged PTH and calcitonin levels suggested that conventional bone and Ca metabolic pathways were not involved or changed in compensation. Thus, GX-induced bone pathology was different from a typical osteomalacia. Gene expression profiles through microarray analysis and data mining using Ingenuity Pathway Analysis indicated that 612 genes were up-regulated and 1,097 genes were down-regulated in the GX bone. These genes were related functionally to connective tissue development, skeletal and muscular system development and function, Ca signaling and the role of osteoblasts, osteoclasts and chondrocytes. Network analysis indicated 9 genes (Aldehyde dehydrogenase 1 family, member A1; Aquaporin 9; Interleukin 1 receptor accessory protein; Very low density lipoprotein receptor; Periostin, osteoblast specific factor; Aggrecan; Gremlin 1; Angiopoietin-like 4; Wingless-type MMTV integration site family, member 10B were hubs connected with tissue development and immunological diseases. These results suggest that chronic systemic inflammation might underlie the GX-induced pathological changes in bone.

  10. Effects of Sigma Anti-bonding Molecule Calcium Carbonate on bone turnover and calcium balance in ovariectomized rats.

    Science.gov (United States)

    Choi, So-Young; Park, Dongsun; Yang, Goeun; Lee, Sun Hee; Bae, Dae Kwon; Hwang, Seock-Yeon; Lee, Paul K; Kim, Yun-Bae; Kim, Ill-Hwa; Kang, Hyun-Gu

    2011-12-01

    This study was conducted to evaluate the effect of Sigma Anti-bonding Molecule Calcium Carbonate (SAC) as therapy for ovariectomy-induced osteoporosis in rats. Three weeks after surgery, fifteen ovariectomized Sprague-Dawley rats were divided randomly into 3 groups: sham-operated group (sham), ovariectomized group (OVX) and SAC-treatment group (OVX+SAC). The OVX+SAC group was given drinking water containing 0.0012% SAC for 12 weeks. Bone breaking force and mineralization as well as blood parameters related to the bone metabolism were analyzed. In OVX animals, blood concentration of 17β-estradiol decreased significantly, while osteocalcin and type I collagen C-terminal telopeptides (CTx) increased. Breaking force, bone mineral density (BMD), calcium and phosphorus in femurs, as well as uterine and vaginal weights, decreased significantly following OVX. However, SAC treatment (0.0012% in drinking water) not only remarkably restored the decreased 17β-estradiol and increased osteocalcin and CTx concentrations, but also recovered decreased femoral breaking force, BMD, calcium and phosphorus, although it did not reversed reproductive organ weights. It is suggested that SAC effectively improve bone density by preventing bone turnover mediated osteocalcin, CTx and minerals, and that it could be a potential candidate for therapy or prevention of postmenopausal osteoporosis.

  11. Higher bone turnover is related to spinal radiographic damage and low bone mineral density in ankylosing spondylitis patients with active disease: a cross-sectional analysis.

    Directory of Open Access Journals (Sweden)

    Suzanne Arends

    Full Text Available INTRODUCTION: Ankylosing spondylitis (AS is characterized by excessive bone formation and bone loss. Our aim was to investigate the association of bone turnover markers (BTM with spinal radiographic damage and bone mineral density (BMD in AS patients with active disease. METHODS: 201 consecutive AS outpatients of the Groningen Leeuwarden AS (GLAS cohort were included. Serum markers of bone resorption (C-telopeptides of type-I collagen, sCTX and bone formation (procollagen type-I N-terminal peptide, PINP; bone-specific alkaline phosphatase, BALP were measured. Z-scores were used to correct for the normal influence that age and gender have on bone turnover. Radiographs were scored by two independent readers according to modified Stoke AS Spinal Score (mSASSS. The presence of complete bridging (ankylosis of at least two vertebrae was considered as measure of more advanced radiographic damage. Low BMD was defined as lumbar spine and/or hip BMD Z-score ≤ -1. RESULTS: Of the 151 patients with complete data, 52 (34% had ≥ 1 complete bridge, 49 (33% had ≥ 1 syndesmophyte (non-bridging, and 50 (33% had no syndesmophytes. 66 (44% had low BMD. Patients with bridging had significantly higher sCTX and PINP Z-scores than patients without bridging (0.43 vs. -0.55 and 0.55 vs. 0.04, respectively. Patients with low BMD had significantly higher sCTX Z-score than patients with normal BMD (-0.08 vs. -0.61. After correcting for gender, symptom duration, and CRP, sCTX Z-score remained significantly related to the presence of low BMD alone (OR: 1.60, bridging alone (OR: 1.82, and bridging in combination with low BMD (OR: 2.26. CONCLUSIONS: This cross-sectional study in AS patients with active and relatively long-standing disease demonstrated that higher serum levels of sCTX, and to a lesser extent PINP, are associated with the presence of complete bridging. sCTX was also associated with low BMD. Longitudinal studies are needed to confirm that serum levels of s

  12. Significance of CEA, CA15-3 and biochemical markers of bone turnover in the diagnosis of bone metastasis from breast cancer

    International Nuclear Information System (INIS)

    Objective: To evaluate the significance of tumor markers CEA and CA15-3, and biochemical markers of bone turnover (total procollagen type Ⅰ amino-terminal propeptide (TP Ⅰ NP), β-isomerized carboxyterminal propeptide (β-CTx), ALP and PTH) in the diagnosis of bone metastasis from breast cancer. Methods: A total of 78 patients (all females) with mean age (56.72 ± 10.76) years, who were diagnosed with breast cancer, were included in this study. The patients were divided into two groups based on radionuclide bone imaging: with bone metastasis (n=32) and without bone metastasis (n=46). The serum concentrations of CEA, CA15-3, TP Ⅰ NP, β-CTx, PTH, ALP were measured. Gleason scores were evaluated. The diagnostic value was evaluated by ROC curve.The two groups were compared using two-sample t test. The correlations between bone metastasis and tumor markers, bone metastasis and biochemical markers of bone turnover were analyzed with Pearson correlation and logistic analysis. Results: The serum levels of CEA, CA15-3, TP Ⅰ NP, β-CTx, PTH and ALP were significantly higher in the group with bone metastasis than those in the group without bone metastasis (t: 4.16-7.56, all P<0.05). For the diagnosis of bone metastasis from breast cancer, the AUC of CEA, CA15-3, TP Ⅰ NP, [β-CTx, PTH and ALP was 0.815, 0.887, 0.869, 0.852, 0.844, 0.731, respectively. Using the cut-off values of 4.18 μg/L for CEA, 0.04 U/L for CA15-3, 49.70 μg/L for TP Ⅰ NP, 0.47 pg/L for β-CTx,54.90 ng/L for PTH and 49.90 U/L for ALP, the sensitivities were 56.3% (18/32), 75.0% (24/32), 78.1% (25/32), 81.3% (26/32), 78.1% (25/32), 68.8% (22/32) and the specificities were 80.4% (37/46), 84.8% (39/46), 76.1% (35/46), 78.3% (36/46), 69.6% (32/46), 58.7% (27/46), respectively. CEA, CA15-3, TP Ⅰ NP, β-CTx, PTH, ALP and Gleason score were positively correlated with the presence of bone metastasis (r: 0.267-0.636, all P<0.05). CEA, CA15-3, TP Ⅰ NP, β-CTx, PTH and Gleason score were independent

  13. Pegvisomant-induced serum insulin-like growth factor-I normalization in patients with acromegaly returns elevated markers of bone turnover to normal

    DEFF Research Database (Denmark)

    Parkinson, C; Kassem, M; Heickendorff, Lene;

    2003-01-01

    Active acromegaly is associated with increased biochemical markers of bone turnover. Pegvisomant is a GH receptor antagonist that normalizes serum IGF-I in 97% of patients with active acromegaly. We evaluated the effects of pegvisomant-induced serum IGF-I normalization on biochemical markers...... of bone and soft tissue turnover, as well as levels of PTH and vitamin D metabolites, in 16 patients (nine males; median age, 52 yr; range, 28-78 yr) with active acromegaly (serum IGF-I at least 30% above upper limit of an age-related reference range). Serum procollagen III amino-terminal propeptide...

  14. The Influence of Sunlight Exposure on Serum Vitamin D Concentration and Bone Turnover; a controlled clinical trial

    Directory of Open Access Journals (Sweden)

    A Ataie-Jafari

    2008-11-01

    Full Text Available "nBackground: Sunlight exposure is one of the ways for vitamin D synthesis. However, its effect on vitamin D status via experimental studies is poorly understood. This study was undertaken to address the possibility that sunlight exposure may increase the levels of serum vitamin D, and alter bone turnover in healthy young girls."nMethods: In a controlled clinical trial, young girls were assigned to the test group (n= 45 or control group (n= 80. An out­door swimming pool was considered for this project and the test group was required to participate in these sessions at least for 8 sessions and to expose to direct sunlight at least for 20 minutes in each session. They were not allowed to use sun­screen during this time. Control group continued their usual manner of sun exposing. Serum levels of vitamin D, calcium, alkaline phosphatase, parathormone, osteocalcin and crossLaps were measured before and after duration of the study in both groups and compared between them."nResults: Subjects aged 27.46±8.78 years. Serum levels of vitamin D and bone markers were constant during the study in both groups. Changes of these variables were not significant between the groups after the study. Serum vitamin D in sub­jects with white skin color correlated with total time of direct sun exposing after the study (P= 0.002."nConclusion: Sunlight exposure did not affect the serum vitamin D and bone turnover in healthy young girls. However, sub­jects with bright skin complexion benefit from sunlight exposing more than those with a dark skin color in the case of vita­min D improvement.  

  15. Are levels of bone turnover related to lower bone mass of adolescents previously fed a macrobiotic diet?

    NARCIS (Netherlands)

    Parsons, T.J.; Dusseldorp, van M.; Seibel, M.J.; Staveren, van W.A.

    2001-01-01

    Dutch adolescents who consumed a macrobiotic (vegan-type) diet in early life, demonstrate a lower relative bone mass than their omnivorous counterparts. We investigated whether subjects from the macrobiotic group showed signs of catching up with controls in terms of relative bone mass, reflected by

  16. Coupling of porcine bone blood flow and metabolism in high-turnover bone disease measured by [{sup 15}O]H{sub 2}O and [{sup 18}F]fluoride ion positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Piert, Morand [Nuclear Medicine, Klinikum Rechts der Isar, Technical University of Munich (Germany); Machulla, Hans-Juergen; Stahlschmidt, Anke; Becker, Georg A. [Radiopharmacy Section, PET Center, University of Tuebingen (Germany); Jahn, Michael; Zittel, Tilman T. [Department of Abdominal and Transplantation Surgery, University of Tuebingen (Germany)

    2002-07-01

    Previously, we identified a parathyroid hormone-related high-turnover bone disease after gastrectomy in mini pigs. Dynamic [{sup 18}F]fluoride ion positron emission tomography (PET) revealed that bone metabolism was significantly increased, but that bone blood flow derived from permeability-surface area product (PS product)-corrected K{sub 1} values was not. Since bone blood flow and metabolism are coupled in normal bone tissues, we hypothesised that the capillary permeability and/or surface area might be altered in high-turnover bone disease. The ''true'' bone blood flow (f{sub H2O}) was measured in vertebral bodies by dynamic [{sup 15}O]H{sub 2}O PET, followed by a 120-min dynamic [{sup 18}F]fluoride ion PET study, 6 months after total gastrectomy (n=5) and compared with results in sham-operated animals (n=5). Estimates for bone blood flow based on PS-corrected K{sub 1} values (f) and the net uptake of fluoride in bone tissue (K{sub i}), representing the bone metabolic activity, were calculated using standard compartmental modelling and non-linear fitting. Gastrectomy was followed by a significant elevation of K{sub i} and k{sub 3} (P<0.05), which was mainly caused by an increase of the fraction of bound tracer in tissue (P<0.01). In contrast, f{sub H2O}, f, the single-pass extraction fraction of [{sup 18}F]fluoride (E) and the volume of distribution (DV) of [{sup 18}F]fluoride were not significantly different between groups. In both groups, a coupling of the mean f{sub H2O} and K{sub i} values was found, but the intercept with the y-axis was higher in high-turnover bone disease. It is concluded that in high-turnover bone disease following gastrectomy, the PS product for [{sup 18}F]fluoride remains unchanged. Therefore, even in high-turnover bone diseases, [{sup 18}F]fluoride ion PET can provide reliable blood flow estimates (f), as long as a proper PS product correction is applied. The increased bone metabolism in high-turnover bone disease

  17. Coupling of porcine bone blood flow and metabolism in high-turnover bone disease measured by [15O]H2O and [18F]fluoride ion positron emission tomography

    International Nuclear Information System (INIS)

    Previously, we identified a parathyroid hormone-related high-turnover bone disease after gastrectomy in mini pigs. Dynamic [18F]fluoride ion positron emission tomography (PET) revealed that bone metabolism was significantly increased, but that bone blood flow derived from permeability-surface area product (PS product)-corrected K1 values was not. Since bone blood flow and metabolism are coupled in normal bone tissues, we hypothesised that the capillary permeability and/or surface area might be altered in high-turnover bone disease. The ''true'' bone blood flow (fH2O) was measured in vertebral bodies by dynamic [15O]H2O PET, followed by a 120-min dynamic [18F]fluoride ion PET study, 6 months after total gastrectomy (n=5) and compared with results in sham-operated animals (n=5). Estimates for bone blood flow based on PS-corrected K1 values (f) and the net uptake of fluoride in bone tissue (Ki), representing the bone metabolic activity, were calculated using standard compartmental modelling and non-linear fitting. Gastrectomy was followed by a significant elevation of Ki and k3 (PH2O, f, the single-pass extraction fraction of [18F]fluoride (E) and the volume of distribution (DV) of [18F]fluoride were not significantly different between groups. In both groups, a coupling of the mean fH2O and Ki values was found, but the intercept with the y-axis was higher in high-turnover bone disease. It is concluded that in high-turnover bone disease following gastrectomy, the PS product for [18F]fluoride remains unchanged. Therefore, even in high-turnover bone diseases, [18F]fluoride ion PET can provide reliable blood flow estimates (f), as long as a proper PS product correction is applied. The increased bone metabolism in high-turnover bone disease after gastrectomy is mainly related to an up-regulation of the amount of ionic exchange of [18F]fluoride with the bone matrix, while tracer delivery remains unchanged. (orig.)

  18. The effect of three years of TNF alpha blocking therapy on markers of bone turnover and their predictive value for treatment discontinuation in patients with ankylosing spondylitis : a prospective longitudinal observational cohort study

    NARCIS (Netherlands)

    Arends, S.; Spoorenberg, A.; Houtman, P.M.; Leijsma, M.K.; Bos, R.; Kallenberg, C.G.; Groen, H.; Brouwer, E.; van der Veer, E.

    2012-01-01

    Introduction: The aim of this study was to investigate the effect of three years of tumor necrosis factor-alpha (TNF-alpha) blocking therapy on bone turnover as well as to analyze the predictive value of early changes in bone turnover markers (BTM) for treatment discontinuation in patients with anky

  19. Vitamin D status of 51-75-year-old Irish women: its determinants and impact on biochemical indices of bone turnover

    DEFF Research Database (Denmark)

    Hill, T. R.; O'Brien, M. M.; Lamberg-Allardt, C.;

    2006-01-01

    Objectives: To assess the vitamin D status of Irish postmenopausal women during wintertime, and to examine its relationship with serum parathyroid hormone (PTH) and biochemical markers of bone turnover. In addition, the determinants of wintertime serum 25-hydroxyvitamin D (25OH-D) levels in these...

  20. Changes of biochemical markers of bone turnover and YKL-40 following hormonal treatment for metastatic prostate cancer are related to survival

    DEFF Research Database (Denmark)

    Johansen, Julia S; Brasso, Klaus; Iversen, Peter;

    2007-01-01

    Elevated serum levels of biochemical markers of bone turnover and YKL-40 in patients with metastatic prostate cancer (PC) at the time of diagnosis are associated to poor prognosis. In this study, we evaluated the value of these biomarkers in monitoring the patients during hormonal treatment....

  1. Effects of Low-Dose Testosterone Undecanoate Treatment on Bone Mineral Density and Bone Turnover Markers in Elderly Male Osteoporosis with Low Serum Testosterone

    Directory of Open Access Journals (Sweden)

    Yan-Jiao Wang

    2013-01-01

    Full Text Available This prospective 2-year, single-center, randomized, placebo-controlled, open-label clinical trial was performed to evaluate the efficacy of low-dose testosterone undecanoate (TU treatment on bone mineral density (BMD and biochemical markers of bone turnover in elderly male osteoporosis with low serum testosterone. A total of 186 elderly male osteoporosis patients with low serum testosterone were randomized into three groups: low-dose TU (20 mg, per day, standard-dose TU (40 mg, per day, and placebo group with a 24-month followup. Since the 6th month in standard-dose TU group or since the 12th month followup in low-dose TU group and throughout the study, lumbar spine and femoral neck BMD and serum levels of free testosterone, estradiol, and bone alkaline phosphatase significantly increased. There were no significant differences between groups of low-dose TU and standard dose TU in the percentage of changes of these data since the 18th month followup and throughout the study. No side effects on prostate glands including prostate specific antigen were found. In conclusion, low-dose TU (20 mg, per day may be a cost effective and safe protocol for treating elderly male osteoporosis with low serum testosterone.

  2. Vitamin D and estrogen receptor-alpha genotype and indices of bone mass and bone turnover in Danish girls

    DEFF Research Database (Denmark)

    Cusack, S.; Mølgaard, C.; Michaelsen, K. F.;

    2006-01-01

    Peak bone mass is a major determinant of osteoporosis risk in later life. It is under strong genetic control; however, little is known about the identity of the genes involved. In the present study, we investigated the relationship between polymorphisms in the genes encoding the vitamin D receptor...

  3. Common Genetic Variation in the DKK1 Gene is Associated with Hip Axis Length but not with Bone Mineral Density and Bone Turnover Markers in Young Adult Men: Results from the Odense Androgen Study

    DEFF Research Database (Denmark)

    Piters, Elke; Balemans, Wendy; Nielsen, Torben Leo;

    2010-01-01

    signaling. Using HapMap, we selected three SNPs covering the genetic variation in a 13.53-kb region comprising DKK1. The Odense Androgen Study is a population-based study comprising 783 Caucasian men aged 20-29 years. BMD and hip structural parameters were available for study. Bone turnover markers were...... used as a secondary end point. All analyses were repeated after adjusting for covariables and in subgroups according to physical activity. We found no significant association between DKK1 and BMD or markers of bone turnover; however, a significant association (P = 0.012) was found for rs1569198...

  4. Skeletal growth and long-term bone turnover after enterocystoplasty in a chronic rat model

    DEFF Research Database (Denmark)

    Gerharz, E.W.; Gasser, J.A.; Mosekilde, Li.;

    2003-01-01

    OBJECTIVE: To investigate skeletal growth and bone metabolism in a chronic animal model of urinary diversion.MATERIALS AND METHODS: Young male Wistar rats (120) were allocated randomly to four groups undergoing: ileocystoplasty, ileocystoplasty and resection of the ileocaecal segment, colocystopl...

  5. Salivary bone turnover markers in healthy pre- and postmenopausal women: daily and seasonal rhythm.

    Science.gov (United States)

    Pellegrini, Gretel G; Gonzales Chaves, Macarena M S; Fajardo, Maria A; Ponce, Graciela M; Toyos, Gloria I; Lifshitz, Fima; Friedman, Silvia M; Zeni, Susana N

    2012-04-01

    No studies had investigated circadian and circannual rhythms of bone biomarkers in whole saliva. We evaluated the salivary daily and seasonal rhythm of carboxy-terminal telopeptide of type I collagen (CTX) and bone alkaline phosphatase (b-ALP). Forty clinical and oral healthy ambulatory pre- and postmenopausal women from two southern Argentine cities: Comodoro Rivadavia (latitude 45º S) and Ushuaia (latitude 54º S) were included in the study. CTX levels were evaluated in serum, urine, and saliva, and b-ALP levels were measured in serum and saliva. In both groups of women, salivary CTX showed a maximum percentage of change early in the morning (80%) and a minimum in the late afternoon (45%), similarly to the pattern observed in urinary samples. No daily rhythm was observed in serum or salivary b-ALP. 25-Hydroxyvitamin D levels decreased in winter vs. summer (p < 0.01) without differences between the two studied groups. Conversely, parathormone reached higher levels in winter (p < 0.05) which induced a slight non-significant increment in salivary CTX and b-ALP levels. The results showed that, as in serum and urinary samples, salivary CTX exhibits daily and a slight seasonal rhythmicity. Whole non-stimulated saliva is a useful tool to detect several oral and systemic diseases because it has important advantages compared to serum and urinary samples. Then, it may also be a promising sample to test changes in bone metabolism contributing to diagnose and to monitor the therapy of several metabolic bone diseases. PMID:21431857

  6. Effects of short-term combined treatment with alendronate and elcatonin on bone mineral density and bone turnover in postmenopausal women with osteoporosis

    Directory of Open Access Journals (Sweden)

    Jun Iwamoto

    2009-07-01

    Full Text Available Jun Iwamoto1, Mitsuyoshi Uzawa2, Yoshihiro Sato3, Tsuyoshi Takeda1, Hideo Matsumoto11Institute for Integrated Sports Medicine, Keio University School of Medicine, Tokyo, Japan; 2Department of Orthopaedic Surgery, Keiyu Orthopaedic Hospital, Gunma, Japan; 3Department of Neurology, Mitate Hospital, Fukuoka, Japan Abstract: The antiresorptive drug elcatonin (ECT is known to relieve pain in postmenopausal women with osteoporosis. A prospective open-labeled trial was conducted to compare the effects of short-term combined treatment with alendronate (ALN and ECT on bone mineral density (BMD and bone turnover with those of single treatment with ALN in postmenopausal women with osteoporosis. Two hundred and five postmenopausal osteoporotic women (mean age: 70 years were recruited in our outpatient clinic. Forty-six women with back pain were treated with ALN and ECT (intramuscular, 20 units a week, and 159 women without obvious back pain were treated with ALN alone. The lumbar BMD, urinary levels of cross-linked N-terminal telopeptides of type I collagen (NTX, and serum levels of alkaline phosphatase (ALP were measured during the six-month treatment period. The baseline characteristics, except for age, body weight and number of patients with prevalent vertebral fractures, were not significantly different between the two groups. The mean increase rate in the lumbar BMD at six months was similar in the ALN (+4.41% and ALN+ECT (+5.15% groups, following similar reduction rates in urinary NTX levels (-40.2% and -43.0%, respectively, at three months and serum ALP levels (-19.0% and -19.7%, respectively, at six months. These results were consistent even after adjustments for age, body weight, and number of patients with prevalent vertebral fractures. The present study in postmenopausal osteoporotic women confirmed that the effects of short-term combined treatment with ALN and ECT on lumbar BMD and bone turnover in patients with back pain appeared to be

  7. Peri-implant and systemic effects of high-/low-affinity bisphosphonate-hydroxyapatite composite coatings in a rabbit model with peri-implant high bone turnover

    Directory of Open Access Journals (Sweden)

    Niu Shun

    2012-06-01

    Full Text Available Abstract Background Hydroxyapatite (HA coatings composed with bisphosphonates (BPs which have high mineral-binding affinities have been confirmed to successfully enhance implant stability. However, few previous studies focused on HA coatings composed with low-affinity BPs or on systemic effects of locally released BPs. Methods In this long-term study, we developed two kinds of BP-HA composite coatings using either high-affinity BP (alendronate, ALN or low-affinity BP (risedronate, RIS. Thirty-six rabbits were divided into three groups according to different coating applications (group I: HA, group II: ALN-HA, and group III: RIS-HA. Implants were inserted into the proximal region of the medullary cavity of the left tibiay. At insertion, 2 × 108 wear particles were injected around implants to induce a peri-implant high bone turnover environment. Both local (left tibias and systemic (right tibias and lumbar vertebrae inhibitory effect on bone resorption were compared, including bone-implant integration, bone architecture, bone mineral density (BMD, implant stability, and serum levels of bone turnover markers. Results The results indicated that ALN-HA composite coating, which could induce higher bone-implant contact (BIC ratio, bone mass augmentation, BMD, and implant stability in the peri-implant region, was more potent on peri-implant bone, while RIS-HA composite coating, which had significant systemic effect, was more potent on non-peri-implant bone, especially lumbar vertebrae. Conclusions It is instructive and meaningful to further clinical studies that we could choose different BP-HA composite coatings according to the patient’s condition.

  8. Biochemical Markers Of Bone Turnover in Egyptian Women at Different Ages

    Directory of Open Access Journals (Sweden)

    Olfat A Khalil &Kholoud S Ramadan

    2011-07-01

    Full Text Available Osteoporosis is a metabolic bone disease characterized by bone remodeling .This study was done for the detection of some blood and urine markers in cases of osteoporosis among Egyptian women at different ages .The study included 100 women divided into three groups. The first group included 33 women their ages ranged between 35-45 years old, the second included 33 women their ages ranged between 45-55 years old and the third group included 34 women their ages were above 55 years old. Fore all subjects DEXA densitometry was performed. Serum calcium, phosphorous, alkaline phosphatase, Osteocalcin and urinary hydroxyproline, deoxypyridinoline and creatinine were estimated. Results: In osteopenic and osteoporotic women there was elevation in serum alkaline phosphatase and osteocalcin and in urinary pyridinoline and hydroxyproline, while there was decrease in serum calcium .Conclusion: The Egyptian women subjected to the study were suffering from osteopenia from the age of 35 years old or may be earlier Above the age of 55 (postmenopausal it was found that 50% of women were osteopenic and osteoporotic.

  9. Levels of serotonin, sclerostin, bone turnover markers as well as bone density and microarchitecture in patients with high bone mass phenotype due to a mutation in Lrp5

    DEFF Research Database (Denmark)

    Nielsen, Morten Frost; Andersen, Tom E.; Gossiel, F;

    2011-01-01

    CONTEXT: Patients with an activation mutation of the Lrp5 gene exhibit high bone mass (HBM). Limited information is available regarding compartment specific changes in bone. The relationship between the phenotype and serum serotonin is not well documented. Objective: to evaluate bone, serotonin...... and forearm and cortical thickness were positively and trabecular area negatively associated with age (r =0.49, 0.57, 0.74 and -0.61, respectively, p ...

  10. Lrp4, a novel receptor for Dickkopf 1 and sclerostin, is expressed by osteoblasts and regulates bone growth and turnover in vivo.

    Directory of Open Access Journals (Sweden)

    Hong Y Choi

    Full Text Available Lrp4 is a multifunctional member of the low density lipoprotein-receptor gene family and a modulator of extracellular cell signaling pathways in development. For example, Lrp4 binds Wise, a secreted Wnt modulator and BMP antagonist. Lrp4 shares structural elements within the extracellular ligand binding domain with Lrp5 and Lrp6, two established Wnt co-receptors with important roles in osteogenesis. Sclerostin is a potent osteocyte secreted inhibitor of bone formation that directly binds Lrp5 and Lrp6 and modulates both BMP and Wnt signaling. The anti-osteogenic effect of sclerostin is thought to be mediated mainly by inhibition of Wnt signaling through Lrp5/6 within osteoblasts. Dickkopf1 (Dkk1 is another potent soluble Wnt inhibitor that binds to Lrp5 and Lrp6, can displace Lrp5-bound sclerostin and is itself regulated by BMPs. In a recent genome-wide association study of bone mineral density a significant modifier locus was detected near the SOST gene at 17q21, which encodes sclerostin. In addition, nonsynonymous SNPs in the LRP4 gene were suggestively associated with bone mineral density. Here we show that Lrp4 is expressed in bone and cultured osteoblasts and binds Dkk1 and sclerostin in vitro. MicroCT analysis of Lrp4 deficient mutant mice revealed shortened total femur length, reduced cortical femoral perimeter, and reduced total femur bone mineral content (BMC and bone mineral density (BMD. Lumbar spine trabecular bone volume per total volume (BV/TV was significantly reduced in the mutants and the serum and urinary bone turnover markers alkaline phosphatase, osteocalcin and desoxypyridinoline were increased. We conclude that Lrp4 is a novel osteoblast expressed Dkk1 and sclerostin receptor with a physiological role in the regulation of bone growth and turnover, which is likely mediated through its function as an integrator of Wnt and BMP signaling pathways.

  11. Effects of denosumab, alendronate, or denosumab following alendronate on bone turnover, calcium homeostasis, bone mass and bone strength in ovariectomized cynomolgus monkeys.

    Science.gov (United States)

    Kostenuik, Paul J; Smith, Susan Y; Samadfam, Rana; Jolette, Jacquelin; Zhou, Lei; Ominsky, Michael S

    2015-04-01

    Postmenopausal osteoporosis is a chronic disease wherein increased bone remodeling reduces bone mass and bone strength. Antiresorptive agents including bisphosphonates are commonly used to mitigate bone loss and fracture risk. Osteoclast inhibition via denosumab (DMAb), a RANKL inhibitor, is a newer approach for reducing fracture risk in patients at increased risk for fracture. The safety of transitioning from bisphosphonate therapy (alendronate; ALN) to DMAb was examined in mature ovariectomized (OVX) cynomolgus monkeys (cynos). One day after OVX, cynos (7-10/group) were treated with vehicle (VEH, s.c.), ALN (50 μg/kg, i.v., twice monthly) or DMAb (25 mg/kg/month, s.c.) for 12 months. Other animals received VEH or ALN for 6 months and then transitioned to 6 months of DMAb. DMAb caused significantly greater reductions in serum CTx than ALN, and transition from ALN to DMAb caused further reductions relative to continued ALN. DMAb and ALN decreased serum calcium (Ca), and transition from ALN to DMAb resulted in a lesser decline in Ca relative to DMAb or to VEH-DMAb transition. Bone histomorphometry indicated significantly reduced trabecular and cortical remodeling with DMAb or ALN. Compared with ALN, DMAb caused greater reductions in osteoclast surface, eroded surface, cortical porosity and fluorochrome labeling, and transition from ALN to DMAb reduced these parameters relative to continued ALN. Bone mineral density increased in all active treatment groups relative to VEH controls. Destructive biomechanical testing revealed significantly greater vertebral strength in all three groups receiving DMAb, including those receiving DMAb after ALN, relative to VEH controls. Bone mass and strength remained highly correlated in all groups at all tested skeletal sites, consistent with normal bone quality. These data indicate that cynos transitioned from ALN to DMAb exhibited reduced bone resorption and cortical porosity, and increased BMD and bone strength, without

  12. Relation between body composition and biochemical markers of bone turnover among early postmenopausal women

    DEFF Research Database (Denmark)

    Hla, M M; Davis, J W; Ross, P D;

    2000-01-01

    We studied the associations between body composition and biochemical markers of bone formation and resorption among 1600 postmenopausal women, ages 45-59. Multiple regression analyses were performed to examine the independent associations of fat mass, muscle strength (quadriceps strength), height......, the mean levels of osteocalcin decreased by 3% and 13%, respectively; NTX decreased by 5 and 21%. Fat mass and whole-body BMC were also significantly associated with decreases in the average of osteocalcin and NTX Z-scores. By contrast, the mean levels of serum osteocalcin increased by 2 and 11......%, respectively, per IQR increase in muscle strength and height; NTX increased by 4 (not significant) and 14%, respectively. Both muscle strength and height were significantly associated with increases in the average Z-scores. These exploratory analyses suggest that fat mass and whole-body BMC were associated...

  13. Bariatric Surgery: Bad to the Bone, Part 1.

    Science.gov (United States)

    Pizzorno, Lara

    2016-03-01

    Obesity is now a global epidemic affecting a significant and rapidly increasing number of adults, adolescents, and children. As the incidence of obesity has increased, so has the use of bariatric surgery as a medical solution. A growing number of studies now report that, despite calcium and vitamin D supplementation, the most frequently performed types of bariatric surgery, the Roux-en-Y gastric bypass and the sleeve gastrectomy, cause significant ongoing bone loss. In resources available to the general public and to physicians, this adverse outcome is rarely mentioned or is attributed solely to reduced calcium absorption. Recent studies investigating micronutrient malabsorption and changes in a wide range of hormones induced by bariatric surgery now indicate that calcium malabsorption is the tip of a formidable iceberg. The current article, part 1 of a 2-part series, reviews the latest research findings confirming that obesity prevalence is skyrocketing and that bariatric surgery causes ongoing, accelerated bone loss. Part 1 also discusses the mechanisms through which the bariatric surgery-induced malabsorption of key nutrients adversely affects bone homeostasis. Part 2 discusses the specific changes seen in bone metabolism after bariatric surgery and reviews current data on the underlying mechanisms, in addition to nutrient malabsorption, which are thought to contribute to bariatric surgery-induced ongoing accelerated bone loss. These processes include mechanical unloading and changes in a wide variety of hormones (eg, leptin, adiponectin, testosterone, estradiol, serotonin, ghrelin, glucagon-like peptide 1, and gastric inhibitory peptide). Also, part 2 covers interventions that may help lessen bariatric surgery-induced bone loss, which are now beginning to appear in the medical literature. Bariatric surgery's adverse effects on bone must be widely recognized and protocols developed to prevent early onset osteoporosis in the recipients of an increasingly utilized

  14. The effects of a 6-month resistance training and dried plum consumption intervention on strength, body composition, blood markers of bone turnover, and inflammation in breast cancer survivors.

    Science.gov (United States)

    Simonavice, Emily; Liu, Pei-Yang; Ilich, Jasminka Z; Kim, Jeong-Su; Arjmandi, Bahram; Panton, Lynn B

    2014-06-01

    The purpose of this study was to examine the effects of resistance training (RT) and dried plum (DP) consumption on strength, body composition, blood markers of bone, and inflammation in breast cancer survivors (BCS). Twenty-three BCS (RT, n = 12; RT+DP, n = 11), aged 64 ± 7 years, were evaluated at baseline and after 6 months of intervention on the following: muscular strength (chest press and leg extension) via 1-repetition maximums (1RMs); body composition, specifically bone mineral density (BMD) by dual energy X-ray absorptiometry; biochemical markers of bone turnover (bone-specific alkaline phosphatase (BAP), tartrate resistant acid phosphatase (TRAP-5b)); and inflammation (C-reactive protein (CRP)). Target RT prescription was 2 days/week of 10 exercises, including 2 sets of 8-12 repetitions at ∼60%-80% of 1RM. RT+DP also consumed 90 g of DP daily. There were no baseline differences between groups or any group-by-time interactions for any of the variables. BCS increased upper (p effective for improving biochemical markers of bone turnover and muscular strength in BCS. A longer and higher intensity intervention may be needed to reveal the true effects of RT and DP on body composition and biochemical markers of inflammation. PMID:24869977

  15. Bone turnover and mineral density in adult thalassemic patients: relationships with growth hormone secretory status and circulating somatomedins.

    Science.gov (United States)

    Scacchi, Massimo; Danesi, Leila; Cattaneo, Agnese; Sciortino, Giovanna; Radin, Raffaella; Ambrogio, Alberto Giacinto; Vitale, Giovanni; D'Angelo, Emanuela; Mirra, Nadia; Zanaboni, Laura; Arvigo, Marica; Boschetti, Mara; Ferone, Diego; Marzullo, Paolo; Baldini, Marina; Cassinerio, Elena; Cappellini, Maria Domenica; Persani, Luca; Cavagnini, Francesco

    2016-08-01

    Previous evidence supports a role for growth hormone (GH)-insulin-like growth factor (IGF)-I deficiency in the pathophysiology of osteopenia/osteoporosis in adult thalassemia. Moreover, serum IGF-II has never been studied in this clinical condition. Thus, we elected to study the GH secretory status and the levels of circulating somatomedins, correlating these parameters with bone mineral density (BMD) and biochemical markers of bone turnover. A hundred and thirty-nine normal weight adult thalassemic patients (72 men and 67 women) were studied. Lumbar and femoral neck BMD were measured in 106/139 patients. Sixty-eight patients underwent growth hormone releasing hormone plus arginine testing. Measurement of baseline IGF-I and IGF-II was performed in all patients, while osteocalcin, C-terminal telopeptide of type I collagen (CTx), and urinary cross-linked N-telopeptides of type I collagen (NTx) were assayed in 95 of them. Femoral and lumbar osteoporosis/Z score below the expected range for age were documented in 61.3 and in 56.6 % of patients, respectively. Severe GH deficiency (GHD) was demonstrated in 27.9 % of cases, whereas IGF-I SDS was low in 86.3 %. No thalassemic patients displayed circulating levels of IGF-II below the reference range. GH peaks were positively correlated with femoral, but not lumbar, Z score. No correlations were found between GH peaks and osteocalcin, CTx and NTx. GH peaks were positively correlated with IGF-I values, which in their turn displayed a positive correlation with osteocalcin, CTx, and NTx. No correlations emerged between IGF-I values and either femoral or lumbar Z scores. No correlations were found between IGF-II and any of the following parameters: GH peaks, osteocalcin, CTx, NTx, femoral Z score, and lumbar Z score. Our study, besides providing for the first time evidence of a normal IGF-II production in thalassemia, contributes to a better understanding of the involvement of the somatotropin-somatomedin axis in the

  16. Supplementation with calcium and short-chain fructo-oligosaccharides affects markers of bone turnover but not bone mineral density in postmenopausal women.

    Science.gov (United States)

    Slevin, Mary M; Allsopp, Philip J; Magee, Pamela J; Bonham, Maxine P; Naughton, Violetta R; Strain, J J; Duffy, Maresa E; Wallace, Julie M; Mc Sorley, Emeir M

    2014-03-01

    This 24-mo randomized, double-blind, controlled trial aimed to examine whether supplementation with a natural marine-derived multi-mineral supplement rich in calcium (Ca) taken alone and in conjunction with short-chain fructo-oligosaccharide (scFOSs) has a beneficial effect on bone mineral density (BMD) and bone turnover markers (BTMs) in postmenopausal women. A total of 300 non-osteoporotic postmenopausal women were randomly assigned to daily supplements of 800 mg of Ca, 800 mg of Ca with 3.6 g of scFOS (CaFOS), or 9 g of maltodextrin. BMD was measured before and after intervention along with BTMs, which were also measured at 12 mo. Intention-to-treat ANCOVA identified that the change in BMD in the Ca and CaFOS groups did not differ from that in the maltodextrin group. Secondary analysis of changes to BTMs over time identified a greater decline in osteocalcin and C-telopeptide of type I collagen (CTX) in the Ca group compared with the maltodextrin group at 12 mo. A greater decline in CTX was observed at 12 mo and a greater decline in osteocalcin was observed at 24 mo in the CaFOS group compared with the maltodextrin group. In exploratory subanalyses of each treatment group against the maltodextrin group, women classified with osteopenia and taking CaFOS had a smaller decline in total-body (P = 0.03) and spinal (P = 0.03) BMD compared with the maltodextrin group, although this effect was restricted to those with higher total-body and mean spinal BMD at baseline, respectively. Although the change in BMD observed did not differ between the groups, the greater decline in BTMs in the Ca and CaFOS groups compared with the maltodextrin group suggests a more favorable bone health profile after supplementation with Ca and CaFOS. Supplementation with CaFOS slowed the rate of total-body and spinal bone loss in postmenopausal women with osteopenia-an effect that warrants additional investigation. This trial was registered at www.controlled-trials.com as ISRCTN63118444. PMID

  17. [The effect of sodium fluoride on selected biochemical markers of bone turnover in ovariectomized rats].

    Science.gov (United States)

    Bohatyrewicz, A

    1998-10-01

    The aim of the study was to investigate the effect of fluoride on selected biochemical markers of bone remodelling in young growing rats and after ovariectomy performed on 12-weeks-old female Wistar rats. Seventy 6-weeks-old female Wistar rats were randomized into seven groups. The first baseline control group was sacrificed before the beginning of the experiment. Two groups served as controls receiving distilled water and the other groups received fluoridated water at different doses (two received 8 and two received 60 mgF-/l). 30 rats (ten from each group) were sacrificed after 6 weeks. Serum was then collected for measurement of fluoride concentration, serum total alkaline phosphatase activity (ALP) and concentration of telopeptide of rat type I collagen (ICTP). Last three groups (ten rats each) were ovariectomized and received than only distilled water to drink. After following six weeks all rats were sacrificed. After six weeks of experiment the group receiving 8 mg F-/l showed the lowest ICTP values and the smallest decrease of serum ALP activity compared to the baseline control group. The rats with higher plasma fluoride concentrations after ovariectomy demonstrated lower ICTP concentrations and higher ALP activity than animals with lower fluoride concentrations. PMID:10101440

  18. Non-invasive markers of bone turnover and plasma cytokines differ in osteoporotic patients with multiple myeloma and monoclonal gammopathies of undetermined significance

    International Nuclear Information System (INIS)

    Multiple myeloma (MM) is a common malignancy manifest by bone marrow infiltration with malignant plasma cells, the production of a paraprotein and lytic bone lesions. Monoclonal gammopathy of undetermined significance (MGUS) is assumed to be the precursor of clinically apparent myeloma, with one or more additional genetic events being required for progression to MM. Elderly patients presenting with osteoporosis and skeletal fractures are not infrequently found to have elevated serum paraprotein concentrations suggestive of either MM or MGUS. Differentiating between these two clinical disorders may prove challenging, despite bone marrow biopsy evidence of plasmacytosis. The underlying pathogenesis of bone loss in these conditions is complex and may be attributed to cytokine-induced osteoclastogenesis coupled with increased osteoclastic bone resorption. In the present study, various markers of bone turnover and plasma cytokines were measured in order to determine whether they may be of value in differentiating between these two disorders. It is concluded that the urinary deoxypyridinoline excretion rate is a sensitive marker of bone resorption and of underlying bone disease activity. It may also help to differentiate between MM and MGUS

  19. The Use of Bone Age in Clinical Practice - Part 1

    NARCIS (Netherlands)

    D.D. Martin; J.M. Wit; Z.E. Hochberg; L. Sävendahl; R.R. van Rijn; O. Fricke; N. Cameron; J. Caliebe; T. Hertel; D. Kiepe; K. Albertsson-Wikland; H.H. Thodberg; G. Binder; M.B. Ranke

    2011-01-01

    This review examines the role of skeletal maturity ('bone age', BA) assessment in clinical practice. BA is mainly used in children with the following conditions: short stature (addressed in part 1 of this review), tall stature, early or late puberty, and congenital adrenal hyperplasia (all addressed

  20. Effects of Glycemic Control on Bone Turnover in Older Mexican Americans with Type 2 Diabetes: Data from the Cameron County Hispanic Cohort in Texas

    Science.gov (United States)

    Rianon, N.; Smith, S. M.; Lee, M.; Musgrave, P.; Nader, S.; Khosla, S.; Ambrose, C.; McCormick, J.; Fisher-Hoch, S.

    2016-01-01

    High bone turnover, evidenced by high serum osteocalcin (OC) concentration, is indicated as risk of fracture in old age. However, low bone turnover has been reported in patients with type 2 diabetes (T2D) who also have high fracture risk. Poor glycemic control indicated by higher glycated hemoglobin levels (HbA1c) has been associated with lower serum OC in older Caucasian and Asian patients with T2D. There remains a gap in knowledge about effects of T2D on bone turnover status in Hispanic populations. We report bone turnover in association with glycemic control in 72 older (greater than or equal to 50 years) men (N=21) and women (N=51) from the Cameron County Hispanic Cohort (CCHC) in Texas. Prevalence of T2D is about 30 percent in this cohort who live in health disparity due to poor access to health care. Separate multivariable linear regression models were conducted to determine association between high/diabetic levels of HbA1c (less than 6.5 normal versus greater than or equal to 6.5 high) and serum OC after controlling for age, body mass index (BMI, greater than 30 obese versus less than 30 non-obese), visceral fat, femoral neck BMD and serum concentrations of creatinine, calcium, and vitamin D for men and women. Interaction effects were assessed while developing final multivariable model to identify factors that modify the association between HbA1c and OC. Subjects were 66 plus or minus 9 (mean plus or minus Standard Deviation) years for men and 67 plus or minus 8 years for women. HbA1c was 8.0 plus or minus 2.0 for men and 7.8 plus or minus 2.0 for women. There were no significant differences for BMI, femoral neck BMD, serum calcium or 25-hydroxyvitamin D concentrations between men and women. High HbA1c was significantly associated with lower OC levels in men in both age groups (mean difference in OC between high vs. low HbA1c [95 percent confidence interval] for older group (greater than or equal to 65 years) was minus 9.51 (minus 16.36 to minus 2.65) and

  1. Effect of odanacatib on bone turnover markers, bone density and geometry of the spine and hip of ovariectomized monkeys: a head-to-head comparison with alendronate.

    Science.gov (United States)

    Williams, Donald S; McCracken, Paul J; Purcell, Mona; Pickarski, Maureen; Mathers, Parker D; Savitz, Alan T; Szumiloski, John; Jayakar, Richa Y; Somayajula, Sangeetha; Krause, Stephen; Brown, Keenan; Winkelmann, Christopher T; Scott, Boyd B; Cook, Lynn; Motzel, Sherri L; Hargreaves, Richard; Evelhoch, Jeffrey L; Cabal, Antonio; Dardzinski, Bernard J; Hangartner, Thomas N; Duong, Le T

    2013-10-01

    Odanacatib (ODN) is a selective and reversible Cathepsin K (CatK) inhibitor currently being developed as a once weekly treatment for osteoporosis. Here, effects of ODN compared to alendronate (ALN) on bone turnover, DXA-based areal bone mineral density (aBMD), QCT-based volumetric BMD (vBMD) and geometric parameters were studied in ovariectomized (OVX) rhesus monkeys. Treatment was initiated 10 days after ovariectomy and continued for 20 months. The study consisted of four groups: L-ODN (2 mg/kg, daily p.o.), H-ODN (8/4 mg/kg daily p.o.), ALN (15 μg/kg, twice weekly, s.c.), and VEH (vehicle, daily, p.o.). L-ODN and ALN doses were selected to approximate the clinical exposures of the ODN 50-mg and ALN 70-mg once-weekly, respectively. L-ODN and ALN effectively reduced bone resorption markers uNTx and sCTx compared to VEH. There was no additional efficacy with these markers achieved with H-ODN. Conversely, ODN displayed inversely dose-dependent reduction of bone formation markers, sP1NP and sBSAP, and L-ODN reduced formation to a lesser degree than ALN. At month 18 post-OVX, L-ODN showed robust increases in lumbar spine aBMD (11.4%, p<0.001), spine trabecular vBMD (13.7%, p<0.001), femoral neck (FN) integral (int) vBMD (9.0%, p<0.001) and sub-trochanteric proximal femur (SubTrPF) int vBMD, (6.4%, p<0.001) compared to baseline. L-ODN significantly increased FN cortical thickness (Ct.Th) and cortical bone mineral content (Ct.BMC) by 22.5% (p<0.001) and 21.8% (p<0.001), respectively, and SubTrPF Ct.Th and Ct.BMC by 10.9% (p<0.001) and 11.3% (p<0.001) respectively. Compared to ALN, L-ODN significantly increased FN Ct. BMC by 8.7% (p<0.05), and SubTrPF Ct.Th by 7.6% (p<0.05) and Ct.BMC by 6.2% (p<0.05). H-ODN showed no additional efficacy compared to L-ODN in OVX-monkeys in prevention mode. Taken together, the results from this study have demonstrated that administration of ODN at levels which approximate clinical exposure in OVX-monkeys had comparable efficacy to ALN in

  2. Healthy looking hospital nurses showing vitamin d deficiency: correlation of vitamin d levels with their levels of parathhyroid hormone and bone turnover markers

    International Nuclear Information System (INIS)

    To evaluate the correlation of low vitamin D levels with parathyroid hormone (PTH) levels and bone turn over markers among apparently healthy hospital nurses. Methods: Screening was done on 50 recruited healthy female nursing staff, aged between 18 to 35 years, for vitamin D levels. Among them 31 were found to be deficient in vitamin D. These 31 nurses were selected for further evaluation in trance. Their vitamin D levels were calculated by using the electrochemiluminescence immunoassay. Blood samples were drawn to estimate serum PTH levels accordingly. Samples were also collected from these recruited subjects to evaluate their bone turn over markers, including, osteocalcin, procollagen type 1 N propeptide and Beta-Crosslaps. Results: Out of 50 subjects, 31 subjects were found to have Vitamin D levels below 50 nmol/l. Out of these 31 subjects, 13 subjects, 41.9%, showed vitamin D levels below 20 nmol/l. Among these 13 subjects, all had significantly raised PTH levels (p-value: <0.001, r-value: -0.781). In rest of all the subjects, including those having Vitamin D levels above 20nmol/l, inordinately, PTH levels were normal. No reciprocity was found between low Vitamin D and raised PTH levels with bone turnover markers, except with P1NP (r-value 0.022). Conclusion: PTH levels show a steep augmentation in serum, when vitamin D levels hit the trough below 20 nmol/l. These are the subjects who should be treated prior to the development of complications of bone resorption. Moreover we could not find any significant correlation of Vitamin D and PTH with any bone turnover marker except P1NP. (author)

  3. ASDAS, BASDAI and different treatment responses and their relation to biomarkers of inflammation, cartilage and bone turnover in patients with axial spondyloarthritis treated with TNF{alpha} inhibitors

    DEFF Research Database (Denmark)

    Pedersen, Susanne Juhl; Sørensen, Inge Juul; Garnero, Patrick;

    2011-01-01

    To investigate the relation between ankylosing spondylitis disease activity score (ASDAS), Bath ankylosing spondylitis disease activity index (BASDAI) and treatment response and biomarkers of inflammation (C-reactive protein (CRP), interleukin-6 (IL-6), YKL-40), angiogenesis (vascular endothelial...... growth factor (VEGF)), cartilage (C-terminal crosslinking telopeptide of type II collagen (CTX-II), matrix metalloproteinase-3 (MMP-3), total aggrecan, cartilage oligomeric matrix protein) and bone (C-terminal crosslinking telopeptide of type I collagen, osteocalcin) turnover in 60 patients with axial...

  4. ASDAS, BASDAI and different treatment responses and their relation to biomarkers of inflammation, cartilage and bone turnover in patients with axial spondyloarthritis treated with TNFα inhibitors

    DEFF Research Database (Denmark)

    Pedersen, Susanne Juhl; Sørensen, Inge Juul; Garnero, Patrick;

    2011-01-01

    To investigate the relation between ankylosing spondylitis disease activity score (ASDAS), Bath ankylosing spondylitis disease activity index (BASDAI) and treatment response and biomarkers of inflammation (C-reactive protein (CRP), interleukin-6 (IL-6), YKL-40), angiogenesis (vascular endothelial...... growth factor (VEGF)), cartilage (C-terminal crosslinking telopeptide of type II collagen (CTX-II), matrix metalloproteinase-3 (MMP-3), total aggrecan, cartilage oligomeric matrix protein) and bone (C-terminal crosslinking telopeptide of type I collagen, osteocalcin) turnover in 60 patients with axial...

  5. Correlation of the Levels of the Bone Turnover Markers BAP and β-CTX with Bone Metastasis Progress in Lung Cancer Patients%BAP和β-CTX与肺癌骨转移进展程度的相关性

    Institute of Scientific and Technical Information of China (English)

    唐琼; 赵辉; 贾锐; 刘林林

    2013-01-01

    背景与目的 肺癌易发生骨转移,Ⅰ型胶原羧基端肽β特殊序列(β isomer of C-terminal telopeptide of type Ⅰ collagen,β-CTX)和骨源性碱性磷酸酶(bone-specific alkaline phosphates,BAP)在骨质代谢中是重要的生化标记物,本研究旨在探讨骨代谢生化指标和肺癌骨转移进展程度的相关性,有助于早期判断是否有肺癌骨转移的发生.方法 天津市人民医院2009年7月-2012年7月共收治92例肺癌并发生骨转移患者,全部病例其原发灶均经细胞学检查证实,骨转移灶的数目及类型经ECT结合X线片、CT证实,采用ELISA方法检测血β-CTX、BAP的浓度水平.结果 收集的92例肺癌伴骨转移的患者中,转移灶<3处为58例,≥3处为34例;溶骨型68例,成骨型9例,混合型15例.血β-CTX、BAP水平在不同的骨转移数目组间差异有统计学意义(P<0.05),β-CTX在肺癌溶骨型骨转移患者中具有较高的敏感性.结论 骨代谢生化指标β-CTX、BAP对肺癌骨转移具有辅助诊断意义,是判断转移进展程度的良好指标.%Background and objective Bone metastasis is common in lung cancer patients. The β isomer of the C-terminal telopeptide of type Ⅰ collagen (β-CTX) and bone-specific alkaline phosphates (BAP) are regarded as important bone turnover markers in bone resorption and formation. Thus, the aims of this study are to determine the correlation of these bone turnover markers with the extent of bone metastasis of lung cancer. Methods A total of 92 patients with bone metastasis of lung cancer from Tianjin Union Medicine Center were enrolled in this study between July 2009 and July 2012. The bone metastasis lesion was diagnosed by ECT combined with X-ray and CT imaging. Trie bone turnover marker levels of β-CTX and BAP were measured by ELISA. Results Among the 92 patients, 58 cases had 3; 68 cases had osteolytic bone metastasis, 9 had osteoblastic bone metastasis, and 15 had mixed bone metastases. The serum levels

  6. Short-term prolactin administration causes expressible galactorrhea but does not affect bone turnover: pilot data for a new lactation agent

    Directory of Open Access Journals (Sweden)

    Smith Patricia C

    2007-07-01

    Full Text Available Abstract Background Medications used to augment lactation increase prolactin secretion but can have intolerable side effects. We examined the biological activity of recombinant human prolactin (r-hPRL as preliminary data for its use to augment lactation. Methods Healthy, non-postpartum women (n = 21 with regular menstrual cycles underwent a seven day randomized, double-blind, placebo-controlled trial of r-hPRL. Expressible galactorrhea, markers of bone turnover, calcium homeostasis and gonadal function were measured and side effects recorded. Results Prolactin levels increased during r-hPRL administration (20.0 ± 2.8 to 231.7 ± 48.9 μg/L at 6 hours; p Conclusion In summary, r-hPRL can cause expressible galactorrhea. Seven days of r-hPRL administration does not adversely affect bone turnover or menstrual cyclicity. Thus, r-hPRL may be a viable option for short-term lactation augmentation. Trial registration Clinical Trials.gov NCT00438490

  7. Effect of the Medicinal Mushroom, Grifola gargal (Agaricomycetes), on Bone Turnover Markers and Serum Lipids in Middle-Aged and Elderly Japanese Women.

    Science.gov (United States)

    Harada, Etsuko; Morizono, Toshihiro; Sumiya, Toshimitsu; Kawagishi, Hirokazu

    2016-01-01

    A clinical study was performed to examine the effect of the edible mushroom, Grifola gargal, on bone turnover markers and serum lipids in middle-aged and elderly Japanese women. Postmenopausal women aged 51-73 years (mean age, 61 years) received daily oral administration of 5 g G. gargal fruiting bodies (hot air-dried and powdered; G. gargal powder [GGP]). Serum levels of bone alkaline phosphatase (BAP) and lipids and urinary deoxypyridinoline (DPD) levels were measured before and 2 weeks after the start of GGP treatment. As a result, urinary DPD bone resorption marker levels in women treated with GGP decreased significantly. Serum levels of the BAP bone formation marker also tended to increase, but the difference was not significant. By contrast, the atherogenic index decreased and the high-density lipoprotein (HDL) ratio increased significantly. However, there were no statistically significant differences in serum lipids of total cholesterol, HDL cholesterol, and low-density lipoprotein cholesterol. In addition, this study demonstrated for the first time that G. gargal is safe for human consumption. PMID:27279439

  8. Reasons for Working Part-Time: Subgroup Differences in Job Attitudes and Turnover Intentions

    Science.gov (United States)

    Maynard, Douglas C.; Thorsteinson, Todd J.; Parfyonova, Natalya M.

    2006-01-01

    Purpose: The purpose of this paper is to explore the factors that might lead an individual to pursue part-time (PT) employment. Design/methodology/approach: The paper hypothesized that employees have very different motivations for PT working, and that these motivations will affect their work experiences. The paper builds on recent research…

  9. The use of bone age in clinical practice - Part 1

    DEFF Research Database (Denmark)

    Martin, D.D.; Caliebe, J.; Binder, Gitte Sommer;

    2011-01-01

    This review examines the role of skeletal maturity ('bone age', BA) assessment in clinical practice. BA is mainly used in children with the following conditions: short stature (addressed in part 1 of this review), tall stature, early or late puberty, and congenital adrenal hyperplasia (all......-up in BA that is usually appropriate for the height of the child. Response to GH is dependent on BA delay in young children with idiopathic short stature, and GH dosage appears to affect BA acceleration. In chronic renal failure, BA is delayed until puberty but then increases due to increased sensitivity...

  10. "Who Stays and Who Leaves?" Findings from a Three-Part Study of Teacher Turnover in NYC Middle Schools. Technical Appendices

    Science.gov (United States)

    Marinell, William H.; Coca, Vanessa M.; Arum, Richard; Goldstein, Jennifer; Kemple, James; Pallas, Aaron; Bristol, Travis; Buckley, Clare; Scallon, Amy; Tanner, Barbara

    2013-01-01

    The technical appendices presented in this document correspond to the synthesis report, "'Who Stays and Who Leaves?' Findings from a Three-Part Study of Teacher Turnover in NYC Middle Schools." The appendices include: (1) Description of Data Source and Samples; (2) Methods; and (3) Who Are the Middle School Teachers in NYC? [The…

  11. The effects of a 6-month resistance training and dried plum consumption intervention on strength, body composition, blood markers of bone turnover, and inflammation in breast cancer survivors.

    Science.gov (United States)

    Simonavice, Emily; Liu, Pei-Yang; Ilich, Jasminka Z; Kim, Jeong-Su; Arjmandi, Bahram; Panton, Lynn B

    2014-06-01

    The purpose of this study was to examine the effects of resistance training (RT) and dried plum (DP) consumption on strength, body composition, blood markers of bone, and inflammation in breast cancer survivors (BCS). Twenty-three BCS (RT, n = 12; RT+DP, n = 11), aged 64 ± 7 years, were evaluated at baseline and after 6 months of intervention on the following: muscular strength (chest press and leg extension) via 1-repetition maximums (1RMs); body composition, specifically bone mineral density (BMD) by dual energy X-ray absorptiometry; biochemical markers of bone turnover (bone-specific alkaline phosphatase (BAP), tartrate resistant acid phosphatase (TRAP-5b)); and inflammation (C-reactive protein (CRP)). Target RT prescription was 2 days/week of 10 exercises, including 2 sets of 8-12 repetitions at ∼60%-80% of 1RM. RT+DP also consumed 90 g of DP daily. There were no baseline differences between groups or any group-by-time interactions for any of the variables. BCS increased upper (p < 0.05) (RT: 64 ± 14 to 80 ± 17 kg; RT+DP: 72 ± 23 to 91 ± 20 kg) and lower (p < 0.05) (RT: 69 ± 20 to 87 ± 28 kg; RT+DP: 78 ± 19 to 100 ± 21 kg) body strength. Body composition and BMD improvements were not observed. TRAP-5b decreased in the RT group (p < 0.05) (4.55 ± 1.57 to 4.04 ± 1.63 U/L) and the RT+DP group (p = 0.07) (5.10 ± 2.75 to 4.27 ± 2.03 U/L). Changes in BAP and CRP were not observed. RT was effective for improving biochemical markers of bone turnover and muscular strength in BCS. A longer and higher intensity intervention may be needed to reveal the true effects of RT and DP on body composition and biochemical markers of inflammation.

  12. Clinical application value of bone turnover markers in non-small-cell lung cancer patients with bone metastases%骨转换标志物在非小细胞肺癌骨转移临床应用价值的研究

    Institute of Scientific and Technical Information of China (English)

    Zhiyu Wang; Chen Yang; Yumei Yang; Zan Shen; Hui Zhao; Yang Yao

    2011-01-01

    Objective: The purpose of this study was to assess the clinical application value of bone turnover markers in non-small-cell lung cancer (NSCLC) patients with bone metastases. Including diagnosing bone metastases, detecting bone metastatic spread. Methods: Alkaline phosphatase (AKP), β-C-terminal telopeptide of type Ⅰ collagen (β-CTx), osteocalcin (OST) and bone alkaline phosphatase (BALP) were measured in 76 patients with bone metastases from NSCLC and 44 normal people. Results: The level of AKP, β-CTx and BALP in patients with bone metastasis was significantly higher than in the normal people. Significant correlation was observed among bone turnover markers. The levels of BALP and OST were significantly correlated with the extent of bone metastasis. The patients with high-level CTx and low-level BALP had higher risk of pathologic fracture. Conclusion: In NSCLC patients with bone metastases, bone turnover markers can help to make diagnosis and evaluate the severity. It will have a wide range of use in clinical practice.

  13. Osteoblast-specific deletion of Pkd2 leads to low-turnover osteopenia and reduced bone marrow adiposity.

    Directory of Open Access Journals (Sweden)

    Zhousheng Xiao

    Full Text Available Polycystin-1 (Pkd1 interacts with polycystin-2 (Pkd2 to form an interdependent signaling complex. Selective deletion of Pkd1 in the osteoblast lineage reciprocally regulates osteoblastogenesis and adipogenesis. The role of Pkd2 in skeletal development has not been defined. To this end, we conditionally inactivated Pkd2 in mature osteoblasts by crossing Osteocalcin (Oc-Cre;Pkd2+/null mice with floxed Pkd2 (Pkd2flox/flox mice. Oc-Cre;Pkd2flox/null (Pkd2Oc-cKO mice exhibited decreased bone mineral density, trabecular bone volume, cortical thickness, mineral apposition rate and impaired biomechanical properties of bone. Pkd2 deficiency resulted in diminished Runt-related transcription factor 2 (Runx2 expressions in bone and impaired osteoblastic differentiation ex vivo. Expression of osteoblast-related genes, including, Osteocalcin, Osteopontin, Bone sialoprotein (Bsp, Phosphate-regulating gene with homologies to endopeptidases on the X chromosome (Phex, Dentin matrix protein 1 (Dmp1, Sclerostin (Sost, and Fibroblast growth factor 23 (FGF23 were reduced proportionate to the reduction of Pkd2 gene dose in bone of Oc-Cre;Pkd2flox/+ and Oc-Cre;Pkd2flox/null mice. Loss of Pkd2 also resulted in diminished peroxisome proliferator-activated receptor γ (PPARγ expression and reduced bone marrow fat in vivo and reduced adipogenesis in osteoblast culture ex vivo. Transcriptional co-activator with PDZ-binding motif (TAZ and Yes-associated protein (YAP, reciprocally acting as co-activators and co-repressors of Runx2 and PPARγ, were decreased in bone of Oc-Cre;Pkd2flox/null mice. Thus, Pkd1 and Pkd2 have coordinate effects on osteoblast differentiation and opposite effects on adipogenesis, suggesting that Pkd1 and Pkd2 signaling pathways can have independent effects on mesenchymal lineage commitment in bone.

  14. Radiocalcium Measurement of Bone Turnover in Disorders of Calcium Metabolism Using a Model Based on an Expanding Pool

    International Nuclear Information System (INIS)

    To determine bone mineralization rate the patient eats a constant daily diet for the duration of the study. 10 μCi of 47CaCl2 are injected intravenously on day one of the investigation. Blood samples are taken at 5, 10, 20, 40 and 90 minutes, 3, 5, 9 and 22 hours and 2, 3, 4, 5 and 7 days. 47Ca radioactivity is measured in all the plasma and daily faecal and urine samples. Bone mineralization is determined using a model based on the concept that the exchangeable calcium pool is continuously expanding according to a power function and that activity is lost from the pool into faeces, urine and bone (by mineralization) in direct proportion to the specific activity of the plasma (S*). The power function can be determined graphically from a log/log plot of the S* data over the first 15 hours. Extrapolation of this line to day 7 permits calculation of the pool size at that time (reciprocal of the calculated Sp*7) and the product of the calculated pool and actual S7* yields the amount of activity in the pool at day 7. This is deducted from the activity retained at day 7 to give the activity attributable to bone mineralization which is then divided by the integrated S* over the 7 days to yield the bone mineralization rate. Usually the whole calculation is performed by curve fitting the data points with the aid of a computer. In contrast to previously published methods for the determination of the bone mineralization rates the results presented are independent of the portion of the S* curve that is analysed and thus bone mineralization can be determined in 7 days, previous methods requiring 14 days or more. The normal mineralization rate is 4-6 mg Ca/kg per day. High values of bone mineralization are found in groups of patients with Paget' s disease, osteomalacia, hyperthyroidism, hyperparathyroidism and renal osteodystrophy. Low values for bone mineralization have been found in some patients with crush fracture osteoporosis and in hypoparathyroidism. Changes in bone

  15. Effects of local delivery of BMP2, zoledronate and their combination on bone microarchitecture, biomechanics and bone turnover in osteoporotic rabbits.

    Science.gov (United States)

    Jing, Da; Hao, Xuguang; Xu, Fang; Liu, Jian; Xu, Fei; Luo, Erping; Meng, Guolin

    2016-01-01

    The hip fracture is one major clinical challenge associated with osteoporosis, resulting in heavy socioeconomic burdens and high mortality. Systemic therapies of anti-osteoporosis drugs are expensive, time-consuming and also evoke substantial side effects, which fails to provide early protection from fractures. Accumulating evidence demonstrates the high bioavailability and therapeutic efficacy of local drug delivery in accelerating facture healing and bone defect repair. This study aims at investigating the effects of local delivery of BMP2 and zoledronate (two promising anabolic/anti-catobolic reagents) encapsulated by fibrin sealants into femoral necks on regulating bone quality and remodeling in osteoporotic rabbits subjected to combined ovariectomy and glucocorticoid injection. We show that 6-week BMP2 delivery exhibited more prominent effect on mitigating trabecular bone microarchitecture deterioration and mechanical strength reduction of femoral necks than local zoledronate treatment. BMP2 plus zoledronate showed more significant improvement of bone microstructure, mechanical strength and bone formation rate at 12 weeks post injection than single BMP2 or zoledronate delivery via μCT, biomechanical, histomorphometric and serum biochemical analyses. This study enriches our knowledge for understanding the availability of local drug delivery for improving bone quantity and quality, which may lead to earlier, safer and more efficient protection from osteoporosis-induced fractures in clinics. PMID:27329730

  16. Potassium bicarbonate supplementation lowers bone turnover and calcium excretion in older men and women a randomized dose-finding trial

    Science.gov (United States)

    The acid load accompanying modern diets may have adverse effects on bone and muscle metabolism. Treatment with alkaline salts of potassium can neutralize the acid load, but the optimal amount of alkali is not established. Our objective was to determine the effectiveness of two doses of potassium bic...

  17. Bone morphometry and mineral contents of the distal part of the fractured third metacarpal bone in thoroughbred racehorses

    International Nuclear Information System (INIS)

    Most of the bone fractures in racehorses occur in the fore limb, especially in the metacarpal joint during the racing and training. The longitudinal fracture of the third metacarpal bone (Mc III) often occurs in the osteosclerotic and/or necrotic lesions in the distal part of the bone. To elucidate the endogenous factors of its fracture, soft radiograms of 4 fractured and 4 non-fractured control cases have been investigated morphometrically by a image analyzer. In addition, to analyze the quality of these bones, 20 elements of mineral contents in the crashed bones have been measured using a fluorescent X-ray analyzer. As the results, the osteosclerotic change was observed in both groups in the plantar side of the distal part of Mc III, however, no significant differences were found in the bone morphometry. No significant differences in the 19 elements of bone mineral were found except Fe. From these findings, the mechanism of the occurrence of the longitudinal fracture in the Mc III remains to be elucidated. In future, further work needs to be done with regard to the mechanical intensity and collagen disposition of the distal part of the Mc III

  18. Interrelationships between tooth properties and biochemical bone turnover markers investigated on six-month-old pig model.

    Science.gov (United States)

    Tymczyna, Barbara; Tatara, Marcin R; Krupski, Witold; Tymczyna-Sobotka, Monika; Bachanek, Teresa

    2013-01-01

    The aim of the study was to determine interrelationships between bone tissue metabolism indices and morphological, biomechanical and densitometric properties of hard dental tissues. First primary maxillary incisor from 6-month-old pigs (N=27) was evaluated in terms of weight and length. Mean volumetric tooth mineral density, total tooth volume, enamel total volume, enamel volumetric mineral density, dentine total volume and dentine volumetric mineral density were estimated with the use of quantitative computed tomography and micro computed tomography techniques. Tooth mineral density and tooth mineral content were evaluated with the use of dual-energy X-ray absorptiometry. Microhardness of enamel was measured using Vicker's test. Evaluations of total calcium, ionized calcium, magnesium, phosphorus, alkaline phosphatase, bone alkaline phosphatase, osteocalcin, C-terminal telopeptide of type-I collagen (CTX), insulin-like growth factor-1, growth hormone and parathyroid hormone were performed in plasma and serum samples. Pearson's correlation coefficients were determined between all the investigated variables, and P<0.05 was considered as statistically significant. The obtained results have shown mainly mutual dependences between biochemical indicators of bone metabolism. Evaluation of CTX concentration in serum of pigs has shown the highest predictive value in relation to morphological, densitometric and biomechanical properties of teeth. PMID:23076035

  19. A seasonal variation of calcitropic hormones, bone turnover and bone mineral density in early and mid-puberty girls - a cross-sectional study

    DEFF Research Database (Denmark)

    Viljakainen, H.T.; Palssa, A.; Karkkainen, M.;

    2006-01-01

    The importance of the seasonal variation of calcitropic hormones to growing skeleton has not been established. We studied whether there exists a seasonal variation in calcitropic hormones, bone mineral density (BMD) and bone remodelling markers in early puberty girls. One hundred and ninety...... intact parathyroid hormone (S-iPTH), serum osteocalcin, urinary pyridinoline and urinary deoxypyridinoline were analysed from fasting samples. The concentration of S-25-OHD and serum osteocalcin differed among months (P seasonal variation. The parathyroid hormone...... correlated negatively with S-25-OHD (r -0 center dot 325, P Seasonal variation in S-25-OHD...

  20. Single nucleotide polymorphisms in bone turnover-related genes in Koreans: ethnic differences in linkage disequilibrium and haplotype

    Directory of Open Access Journals (Sweden)

    Kim Tae-Ho

    2007-11-01

    Full Text Available Abstract Background Osteoporosis is defined as the loss of bone mineral density that leads to bone fragility with aging. Population-based case-control studies have identified polymorphisms in many candidate genes that have been associated with bone mass maintenance or osteoporotic fracture. To investigate single nucleotide polymorphisms (SNPs that are associated with osteoporosis, we examined the genetic variation among Koreans by analyzing 81 genes according to their function in bone formation and resorption during bone remodeling. Methods We resequenced all the exons, splice junctions and promoter regions of candidate osteoporosis genes using 24 unrelated Korean individuals. Using the common SNPs from our study and the HapMap database, a statistical analysis of deviation in heterozygosity depicted. Results We identified 942 variants, including 888 SNPs, 43 insertion/deletion polymorphisms, and 11 microsatellite markers. Of the SNPs, 557 (63% had been previously identified and 331 (37% were newly discovered in the Korean population. When compared SNPs in the Korean population with those in HapMap database, 1% (or less of SNPs in the Japanese and Chinese subpopulations and 20% of those in Caucasian and African subpopulations were significantly differentiated from the Hardy-Weinberg expectations. In addition, an analysis of the genetic diversity showed that there were no significant differences among Korean, Han Chinese and Japanese populations, but African and Caucasian populations were significantly differentiated in selected genes. Nevertheless, in the detailed analysis of genetic properties, the LD and Haplotype block patterns among the five sub-populations were substantially different from one another. Conclusion Through the resequencing of 81 osteoporosis candidate genes, 118 unknown SNPs with a minor allele frequency (MAF > 0.05 were discovered in the Korean population. In addition, using the common SNPs between our study and HapMap, an

  1. The use of bone age in clinical practice - Part 2

    DEFF Research Database (Denmark)

    Martin, D.D.; Binder, Gitte Sommer; Ranke, M.B.;

    2011-01-01

    in congenital adrenal hyperplasia. Bone age (BA) determination in children with skeletal dysplasia is only feasible in a few disorders and estimations should be treated with caution. Radiographs of the left hand and wrist are, however, essential in the diagnosis of many skeletal disorders. Bone mineralization...

  2. Decreased bone tissue mineralization can partly explain subchondral sclerosis observed in osteoarthritis.

    Science.gov (United States)

    Cox, L G E; van Donkelaar, C C; van Rietbergen, B; Emans, P J; Ito, K

    2012-05-01

    mineralization and volume fraction are related to cartilage degeneration at a local level. In addition, both the experimental data and the simulations indicated that a depth-dependent increase in bone volume fraction could be caused by decreased bone matrix mineralization. However, a quantitative comparison showed that decreased mineralization can only explain part of the subchondral sclerosis observed in OA.

  3. Cold-batter mincing of hot-boned and crust-freezing air-chilled turkey breast improved meat turnover time and product quality.

    Science.gov (United States)

    Medellin-Lopez, M; Sansawat, T; Strasburg, G; Marks, B P; Kang, I

    2014-03-01

    The purpose of this research was to evaluate the combined effects of turkey hot-boning and cold-batter mincing technology on acceleration of meat turnover and meat quality improvement. For each of 3 replications, 15 turkeys were slaughtered and eviscerated. Three of the eviscerated carcasses were randomly assigned to water-immersion chilling for chill-boning (CB) and the remaining were immediately hot-boned (HB), half of which were used without chilling whereas the remaining were subjected to crust-freezing air chilling (CFAC) in an air-freezing room (1.0 m/s, -12°C) with/without 1/4; sectioning (HB-1/4;CFAC, HB-CFAC). As a result, CB and HB breasts were minced using 1 of 5 treatments: (1) CB and traditional mincing (CB-T), (2) HB and mincing with no chilling (HB-NC), (3) HB and mincing with CO2 (HB-CO2), (4) HB and mincing after CFAC (HB-CFAC), and (5) HB and mincing after quarter sectioning and CFAC (HB-1/4;CFAC). Traditional water-immersion chilling took an average of 5.5 h to reduce the breast temperature to 4°C, whereas HB-CFAC and HB-1/4;CFAC took 1.5 and 1 h, respectively. The breast of HB-CFAC and HB-1/4;CFAC showed significantly higher pH (6.0-6.1), higher fragmentation index (196-198), and lower R-value (1.0-1.1; P 0.05) in sarcomere length were seen between CB-T and HB-CFAC filets regardless of quarter sectioning. When muscle was minced, the batter pH (5.9) of CB-T was significantly lower (P < 0.05) than those (6.1-6.3) of HB-NC, HB-CO2, and HB-1/4;CFAC, with the intermediate pH (6.0) seen for the HB-CFAC. When meat batters were cooked, higher cooking yield (90 - 91%; P < 0.05) was found in HB-CFAC, HB-1/4;CFAC, and HB-CO2, followed by HB-NC (90%) and finally CB-T (86%). Stress values (47-51 kPa) of HB-CFAC gels were significantly higher (P < 0.05) than those of CB-T (30 kPa) and HB-NC (36 kPa). A similar trend was found in strain values. PMID:24604866

  4. Cold-batter mincing of hot-boned and crust-freezing air-chilled turkey breast improved meat turnover time and product quality.

    Science.gov (United States)

    Medellin-Lopez, M; Sansawat, T; Strasburg, G; Marks, B P; Kang, I

    2014-03-01

    The purpose of this research was to evaluate the combined effects of turkey hot-boning and cold-batter mincing technology on acceleration of meat turnover and meat quality improvement. For each of 3 replications, 15 turkeys were slaughtered and eviscerated. Three of the eviscerated carcasses were randomly assigned to water-immersion chilling for chill-boning (CB) and the remaining were immediately hot-boned (HB), half of which were used without chilling whereas the remaining were subjected to crust-freezing air chilling (CFAC) in an air-freezing room (1.0 m/s, -12°C) with/without 1/4; sectioning (HB-1/4;CFAC, HB-CFAC). As a result, CB and HB breasts were minced using 1 of 5 treatments: (1) CB and traditional mincing (CB-T), (2) HB and mincing with no chilling (HB-NC), (3) HB and mincing with CO2 (HB-CO2), (4) HB and mincing after CFAC (HB-CFAC), and (5) HB and mincing after quarter sectioning and CFAC (HB-1/4;CFAC). Traditional water-immersion chilling took an average of 5.5 h to reduce the breast temperature to 4°C, whereas HB-CFAC and HB-1/4;CFAC took 1.5 and 1 h, respectively. The breast of HB-CFAC and HB-1/4;CFAC showed significantly higher pH (6.0-6.1), higher fragmentation index (196-198), and lower R-value (1.0-1.1; P 0.05) in sarcomere length were seen between CB-T and HB-CFAC filets regardless of quarter sectioning. When muscle was minced, the batter pH (5.9) of CB-T was significantly lower (P batters were cooked, higher cooking yield (90 - 91%; P < 0.05) was found in HB-CFAC, HB-1/4;CFAC, and HB-CO2, followed by HB-NC (90%) and finally CB-T (86%). Stress values (47-51 kPa) of HB-CFAC gels were significantly higher (P < 0.05) than those of CB-T (30 kPa) and HB-NC (36 kPa). A similar trend was found in strain values.

  5. Storage/Turnover rate of inorganic carbon and its dissolvable part in the profile of saline/alkaline soils.

    Directory of Open Access Journals (Sweden)

    Yugang Wang

    Full Text Available Soil inorganic carbon is the most common form of carbon in arid and semiarid regions, and has a very long turnover time. However, little is known about dissolved inorganic carbon storage and its turnover time in these soils. With 81 soil samples taken from 6 profiles in the southern Gurbantongute Desert, China, we investigated the soil inorganic carbon (SIC and the soil dissolved inorganic carbon (SDIC in whole profiles of saline and alkaline soils by analyzing their contents and ages with radiocarbon dating. The results showed that there is considerable SDIC content in SIC, and the variations of SDIC and SIC contents in the saline soil profile were much larger than that in the alkaline profile. SDIC storage accounted for more than 20% of SIC storage, indicating that more than 1/5 of the inorganic carbon in both saline and alkaline soil is not in non-leachable forms. Deep layer soil contains considerable inorganic carbon, with more than 80% of the soil carbon stored below 1 m, whether for SDIC or SIC. More importantly, SDIC ages were much younger than SIC in both saline soil and alkaline soil. The input rate of SDIC and SIC ranged from 7.58 to 29.54 g C m(-2 yr(-1 and 1.34 to 5.33 g C m(-2 yr(-1 respectively for saline soil, and from 1.43 to 4.9 g C m(-2 yr(-1 and 0.79 to 1.27 g C m(-2 yr(-1respectively for alkaline soil. The comparison of SDIC and SIC residence time showed that using soil inorganic carbon to estimate soil carbon turnover would obscure an important fraction that contributes to the modern carbon cycle: namely the shorter residence and higher input rate of SDIC. This is especially true for SDIC in deep layers of the soil profile.

  6. Turnover Time

    Science.gov (United States)

    Ecosystems contain energy and materials such as carbon, nitrogen, phosphorus, and water, and are open to their flow-through. Turnover time refers to the amount of time required for replacement by flow-through of the energy or substance of interest contained in the system, and is ...

  7. Reloading partly recovers bone mineral density and mechanical properties in hind limb unloaded rats

    Science.gov (United States)

    Zhao, Fan; Li, Dijie; Arfat, Yasir; Chen, Zhihao; Liu, Zonglin; Lin, Yu; Ding, Chong; Sun, Yulong; Hu, Lifang; Shang, Peng; Qian, Airong

    2014-12-01

    Skeletal unloading results in decreased bone formation and bone mass. During long-term space flight, the decreased bone mass is impossible to fully recover. Therefore, it is necessary to develop the effective countermeasures to prevent spaceflight-induced bone loss. Hindlimb Unloading (HLU) simulates effects of weightlessness and is utilized extensively to examine the response of musculoskeletal systems to certain aspects of space flight. The purpose of this study is to investigate the effects of a 4-week HLU in rats and subsequent reloading on the bone mineral density (BMD) and mechanical properties of load-bearing bones. After HLU for 4 weeks, the rats were then subjected to reloading for 1 week, 2 weeks and 3 weeks, and then the BMD of the femur, tibia and lumbar spine in rats were assessed by dual energy X-ray absorptiometry (DXA) every week. The mechanical properties of the femur were determined by three-point bending test. Dry bone and bone ash of femur were obtained through Oven-Drying method and were weighed respectively. Serum alkaline phosphatase (ALP) and serum calcium were examined through ELISA and Atomic Absorption Spectrometry. The results showed that 4 weeks of HLU significantly decreased body weight of rats and reloading for 1 week, 2 weeks or 3 weeks did not recover the weight loss induced by HLU. However, after 2 weeks of reloading, BMD of femur and tibia of HLU rats partly recovered (+10.4%, +2.3%). After 3 weeks of reloading, the reduction of BMD, energy absorption, bone mass and mechanical properties of bone induced by HLU recovered to some extent. The changes in serum ALP and serum calcium induced by HLU were also recovered after reloading. Our results indicate that a short period of reloading could not completely recover bone after a period of unloading, thus some interventions such as mechanical vibration or pharmaceuticals are necessary to help bone recovery.

  8. Skeletal Health Part 1: Overview Of Bone Health and Management In the Cancer Setting.

    Science.gov (United States)

    Turner, Bruce; Ali, Sacha; Drudge-Coates, Lawrence; Pati, Jhumur; Nargund, Vinod; Wells, Paula

    2016-01-01

    Cancer-induced bone disease and cancer therapy-induced bone loss are significant skeletal problems related to the treatment for urological and other cancers. Our team of specialists and nurse practitioners developed a nurse practitioner-led Bone Support Clinic for urologic cancer patients at a university hospital in London, England, United Kingdom, to address this issue. The clinic has been well-accepted, has made a positive impact on the patient journey, helps to ensure continuity of care, and highlights patients who require assessment or treatment for impending skeletal-related events in a timely fashion. This article has been divided into two parts for improved readability.

  9. The Executive Turnover Risk Premium

    OpenAIRE

    Peters, Florian S; Wagner, Alexander F

    2012-01-01

    Executive compensation has increased dramatically over the past 15 years, but so has forced CEO turnover. We argue that part of the development of CEO pay can be explained by the adverse consequences that forced turnover implies for a CEO. We ¯nd that for the CEOs of the largest US corporations, a one percentage point increase in exogenous turnover risk is associated with $40,000 to $90,000 more in terms of total compensation. The size of this risk premium is in line with estimates of the imp...

  10. The assessment of metabolism of bone tissue as changes in concentration of biochemical markers of bone turnover in inpatient alcohol dependent women [Ocena metabolizmu tkanki kostnej u kobiet uzależnionych od alkoholu z zastosowaniem markerów obrotu kostnego – osteokalcyny i ctx

    Directory of Open Access Journals (Sweden)

    Wiłkość, Monika

    2013-02-01

    Full Text Available Aim. The aim of this study was the assessment to of metabolism of bone tissue as changes in concentration of biochemical markers of bone turnover in inpatient alcohol dependent women. Methods. The studied group consisted of 50 alcohol dependent female patients who were divided in two groups: one with an activity of AST or ALT above referential values and level of bilirubin and the second one with the activity of transaminases and level of bilirubin within referential values. The level of sex hormones and markers of bone turnover such as osteocalcin and collagen cross laps (ctx were indicated. Results. In the group with an AST, ALT or BIL above referential values, the concentration of FSH in the ovulation phase and luteal phase as well as LH in luteal phase was significantly higher, while ctx and osteocalcin was lower compared to the group with AST, ALT or BIL within referential values. The mean concentrations of FSH in follicular phase and luteal phase as well as LH in the luteal phase and progesterone in the follicular phase were increased in the group of patients with AST, ALT or BIL above referential values. The positive correlation between levels of ctx and osteocalcin was found which suggests a balance between processes of bone formation and bone resorption in the whole group while a lack of such correlation was observed in patients with AST, ALT or BIL above referential values. Conclusions. The results obtained indicate the multidirectional and mutual relations between the alcohol abuse, liver function, bone turnover and activity of endocrine system.

  11. Analysis on the relationship between renal osteodystrophy and the biochemical marker of bone turnover and other related factors in patients with chronic kidney diseases

    International Nuclear Information System (INIS)

    Objective: To investigate the relationship between renal osteodystrophy and the biochemical marker of bone turnover in patients with chronic kidney diseases. Methods: A total of 102 patients with chronic kidney diseases (CKD) and 52 healthy subjects (normal control) were included in this study. The level of total procollagen type Ⅰ amino-terminal propeptide of (TP Ⅰ NP), β-isomerized carboxyterminal propeptide (β-CTx), intact parathyroid hormone (iPTH), serum calcium (Ca2+), serum phosphorus (P), alkaline phosphatase (ALP) were detected. The correlations between renal osteodystrophy in the patients with chronic kidney diseases and other related factors were analyzed. Results: Compared with the normal control group, there were higher TP Ⅰ NP, β-CTx, iPTH, P, ALP, Cr, Bun and β2-MG, in the CKD group which were significantly different according to Mann-Whitney U test (P<0.05 or <0.01). The Ca2+ and 1, 25-OH Vitamin d3 [1, 25 (OH)2D3] in the CKD group were significantly decreased compared with the normal control group (P<0.05). Correlation analysis showed TP Ⅰ NP was positively correlated with β-CTx, iPTH, P, CaxP, ALP, Cr, Bun, β2-MG (r was 0.790, 0.681, 0.573, 0.541, 0.550, 0.598, 0.793 respectively, P<0.01), Correlation analysis showed β-CTx was positively correlated with iPTH, P, CaxP, ALP, Cr, Bun, β2-MG (r was 0.803, 0.527, 0.449, 0.659, 0.672, 0.565, 0.624 respectively, P<0.01). TP Ⅰ NP was negatively correlated with Ca2+ and 1, 25 (OH)2D3 (r was -0.302, -0.582 respectively, P<0.01). β-CTx was negatively correlated with Ca2+ and 1, 25 (OH)2D3 (r was -0.265, -0.595 respectively, P<0.01). The iPTH was positively correlated with age, TP Ⅰ NP, β-CTx, P, CaxP, ALP, Cr, Bun and β2-MG (r was 0.485, 0.681, 0.803, 0.630, 0.541, 0.486, 0.690, 0.648, 0.531 respectively, P<0.05 or <0.01), but was negatively correlated with Ca2+ and 1, 25 (OH)2D3 (r was -0.318, -0.621 respectively, P<0.05). Conclusion: The application of total procollagen type

  12. Bone ingrowth on the surface of endosseous implants. Part 1: Mathematical model

    OpenAIRE

    Moreo, Pedro; Manuel García-Aznar, José; Doblaré, Manuel

    2009-01-01

    Bone ingrowth on the surface of endosseous implants. Part 1: Mathematical model correspondence: Corresponding author. Tel.: +34 976 761912; fax: +34 976 762578. (Manuel Garcia-Aznar, Jose) (Manuel Garcia-Aznar, Jose) Group of Structural Mechanics and Materials Modelling, Aragon Institute of Engineering Research (I3A), University of Zaragoza - Zaragoza--> - SPAIN (Moreo, Pedro) CIBER-BBN Centro Investigacion Biome...

  13. A Trimodality Comparison of Volumetric Bone Imaging Technologies. Part I: Short-term Precision and Validity

    Science.gov (United States)

    Wong, Andy K. O.; Beattie, Karen A.; Min, Kevin K. H.; Webber, Colin E.; Gordon, Christopher L.; Papaioannou, Alexandra; Cheung, Angela M. W.; Adachi, Jonathan D.

    2016-01-01

    In vivo peripheral quantitative computed tomography (pQCT) and peripheral magnetic resonance imaging (pMRI) modalities can measure apparent bone microstructure at resolutions 200 μm or higher. However, validity and in vivo test-retest reproducibility of apparent bone microstructure have yet to be determined on 1.0 T pMRI (196 μm) and pQCT (200 μm). This study examined 67 women with a mean age of 74 ± 9 yr and body mass index of 27.65 ± 5.74 kg/m2, demonstrating validity for trabecular separation from pMRI, cortical thickness, and bone volume fraction from pQCT images compared with high-resolution pQCT (hr-pQCT), with slopes close to unity. However, because of partial volume effects, cortical and trabecular thickness of bone derived from pMRI and pQCT images matched hr-pQCT more only when values were small. Short-term reproducibility of bone outcomes was highest for bone volume fraction (BV/TV) and densitometric variables and lowest for trabecular outcomes measuring microstructure. Measurements at the tibia for pQCT images were more precise than at the radius. In part I of this 3-part series focused on trimodality comparisons of precision and validity, it is shown that pQCT images can yield valid and reproducible apparent bone structural outcomes, but because of longer scan time and potential for more motion, the pMRI protocol examined here remains limited in achieving reliable values. PMID:25129405

  14. Turnover among healthcare professionals.

    Science.gov (United States)

    Wood, Ben D

    2009-01-01

    Turnover among healthcare professionals is a costly consequence. The existing body of knowledge on healthcare professional turnover is correlated with job satisfaction levels. A landmark study differentiated 2 areas of job satisfaction categories: satisfiers and dissatisfiers (intrinsic and extrinsic motivators). The aim of this article is to examine existing research on precursors of turnover, such as burnout behaviors experienced by healthcare professionals, job satisfaction levels, employee organizational commitment, health complications which precede turnover, some current strategies to reduce turnover, and some effects CEO turnover has on employee turnover intentions.

  15. Assessment of soy phytoestrogens' effects on bone turnover indicators in menopausal women with osteopenia in Iran: a before and after clinical trial

    Directory of Open Access Journals (Sweden)

    Larijani Bagher

    2005-10-01

    Full Text Available Abstract Background Osteoporosis is the gradual declining in bone mass with age, leading to increased bone fragility and fractures. Fractures in hip and spine are known to be the most important complication of the disease which leads in the annual mortality rate of 20% and serious morbidity rate of 50%. Menopause is one of the most common risk factors of osteoporosis. After menopause, sex hormone deficiency is associated with increased remodeling rate and negative bone balance, leading to accelerated bone loss and micro-architectural defects, resulting into increased bone fragility. Compounds with estrogen-like biological activity similar to "Isoflavones" present in plants especially soy, may reduce bone loss in postmenopausal women as they are similar in structure to estrogens. This research, therefore, was carried out to study the effects of Iranian soy protein on biochemical indicators of bone metabolism in osteopenic menopausal women. Materials and methods This clinical trial of before-after type was carried out on 15 women 45–64 years of age. Subjects were given 35 g soy protein per day for 12 weeks. Blood and urine sampling, anthropometric measurement and 48-h-dietary recalls were carried out at zero, 6 and 12 weeks. Food consumption data were analyzed using Food Proccessor Software. For the study of bone metabolism indicators and changes in anthropometric data as well as dietary intake, and repeated analyses were employed. Results Comparison of weight, BMI, physical activity, energy intake and other intervening nutrients did not reveal any significant changes during different stages of the study. Soy protein consumption resulted in a significant reduction in the urinary deoxypyridinoline and increasing of total alkaline phosphatase (p Conclusion In view of beneficial effect of soy protein on bone metabolism indicators, inclusion of this relatively inexpensive food in the daily diet of menopausal women, will probably delay bone

  16. Addressing employee turnover and retention: keeping your valued performers.

    Science.gov (United States)

    McConnell, Charles R

    2011-01-01

    Employee turnover and employee retention are inextricably linked; to control turnover is to enhance retention. Turnover is a relatively simple concept; however, considerable confusion often results when addressing turnover because of differences in how it is defined; that is, what is counted, how it is counted, and how the turnover rates are expressed. Turnover is also costly, although not enough attention is paid to its cost because so much of it is indirect and thus not readily visible. There are a variety of causes of turnover, some that can be corrected and some that cannot be avoided. Reducing or otherwise controlling turnover requires continuing management attention to its causes and constant recognition of what can and should be controlled and what cannot be controlled. Ongoing attention to turnover is an essential part of the department manager's role; every improvement in turnover is a direct improvement in retention, with eventual positive effects on the bottom line.

  17. Bone

    Science.gov (United States)

    Helmberger, Thomas K.; Hoffmann, Ralf-Thorsten

    The typical clinical signs in bone tumours are pain, destruction and destabilization, immobilization, neurologic deficits, and finally functional impairment. Primary malignant bone tumours are a rare entity, accounting for about 0.2% of all malignancies. Also benign primary bone tumours are in total rare and mostly asymptomatic. The most common symptomatic benign bone tumour is osteoid osteoma with an incidence of 1:2000.

  18. Bone Markers

    Science.gov (United States)

    ... bone turnover: C-telopeptide (C-terminal telopeptide of type 1 collagen (CTx)) – a marker for bone resorption. It is ... resorption include: N-telopeptide (N-terminal telopeptide of type 1 collagen (NTx)) – a peptide fragment from the amino terminal ...

  19. Function of osteocytes in bone.

    Science.gov (United States)

    Aarden, E M; Burger, E H; Nijweide, P J

    1994-07-01

    Although the structural design of cellular bone (i.e., bone containing osteocytes that are regularly spaced throughout the bone matrix) dates back to the first occurrence of bone as a tissue in evolution, and although osteocytes represent the most abundant cell type of bone, we know as yet little about the role of the osteocyte in bone metabolism. Osteocytes descend from osteoblasts. They are formed by the incorporation of osteoblasts into the bone matrix. Osteocytes remain in contact with each other and with cells on the bone surface via gap junction-coupled cell processes passing through the matrix via small channels, the canaliculi, that connect the cell body-containing lacunae with each other and with the outside world. During differentiation from osteoblasts to mature osteocyte the cells lose a large part of their cell organelles. Their cell processes are packed with microfilaments. In this review we discuss the various theories on osteocyte function that have taken in consideration these special features of osteocytes. These are 1) osteocytes are actively involved in bone turnover; 2) the osteocyte network is through its large cell-matrix contact surface involved in ion exchange; and 3) osteocytes are the mechanosensory cells of bone and play a pivotal role in functional adaptation of bone. In our opinion, especially the last theory offers an exciting concept for which some biomechanical, biochemical, and cell biological evidence is already available and which fully warrants further investigations.

  20. Bone

    International Nuclear Information System (INIS)

    Bone scanning provides information on the extent of primary bone tumors, on possible metastatic disease, on the presence of osteomyelitis prior to observation of roentgenographic changes so that earlier therapy is possible, on the presence of collagen diseases, on the presence of fractures not disclosed by x-ray films, and on the evaluation of aseptic necrosis. However, the total effect and contribution of bone scanning to the diagnosis, treatment, and ultimate prognosis of pediatric skeletal diseases is, as yet, unknown. (auth)

  1. Global Foreign Exchange Turnover

    OpenAIRE

    Crystal Ossolinski; Andrew Zurawski

    2010-01-01

    The most recent six-monthly data on global foreign exchange turnover show a rebound in activity between April and October 2009 across all markets and major currency pairs. The broad-based increase in turnover is in line with the improvement in global economic and financial conditions since early 2009. Despite the rebound, turnover remains below the peak in early 2008.

  2. Schistosoma mansoni; relationship between membrane turnover rates and susceptibility to immune damage. Part of a coordinated programme on preparation of irradiated vaccines against some human diseases

    International Nuclear Information System (INIS)

    It is known that the schistosomulum of Schistosoma mansoni become refractory to damage by antibody and complement in vitro in the presence of serum, or Concanavalin A (Con A), or after contact with host tissues, presumably due to intrinsic changes in the surface membrane. This project studied the effect of dialysed fetal calf serum (DFCS) and Con A on the synthesis and turnover of individual proteins in the surface membrane using the incorporation of 14C- and 3H-labelled Arginine and the separation of the membrane proteins in SDS-PAGE. The results indicate that during the period in which schistosomules become resistant to immune attack, no qualitative alterations in electrophoretic patterns of surface proteins were observed. There was, however, a marked heterogeneity in synthesis and degradation among constituent proteins. In addition, Con A which had been shown to be effective in stimulating loss of susceptibility to immune attack, caused a slight decrease in the synthesis and turnover rate of high molecular weight proteins, whilst DFCS increased synthesis and turnover of low molecular weight proteins. This suggests that at least two processes occur in the membrane which may be related to the development of protection against immune attack. Serum might stimulate the loss of crucial antigens by accelerating their turnover making antibody attachment difficult, and Con A could be stabilizing the membrane by crosslinking large macromolecules. It is possible that in vivo both mechanisms occur to make the schistosomule surface refractory to damage

  3. A rare anomaly of 5 ossicles in the pre-interparietal part of the squamous occipital bone in north Indians.

    OpenAIRE

    Gopinathan, K

    1992-01-01

    Examination of 125 adult north Indian skulls revealed a rare anomaly of 5 large ossicles in the upper central part of the squamous occipital bone. Their location and possible derivation are briefly discussed.

  4. 骨转换率对大鼠正畸牙齿移动量及牙根吸收的影响%The Rate of Teeth Movement and the Roots Resorption is Influenced by Bone Turnover in Rat Orthodontic Treatment Model

    Institute of Scientific and Technical Information of China (English)

    郑红; 殷丽华; 李秀华; 李静

    2012-01-01

    Objective: To study in a rat model, whether a state of high or low bone turnover had an effect on the incidence of root resorption induced by orthodontic treatment. Methods: Design performing orthodontic teeth movement in 30, 180 - 220 gram male rats with: high(n=10), low bone turnover (n= 10) , and normal (n= 10)groups. The high and low bone turnover groups were obtained by induction of hyperthyroidism and hypothyroidism, respectively. The upper left first molar was moved for 21 days. Bone markers were administered 15 and 2 days before killing. Results: The amount of teeth movement increased with longest tooth roots in high bone turnover group. Conclusion: Bone turnover affected the amount of teeth movement. High bone turnover increased the amount of teeth movement and decreased the the amount of teeth roots resorption.%目的:研究在不同骨转换率的条件下,大鼠牙齿移动过程中牙齿移动量及对牙根吸收的影响.方法:健康成年雄性威斯塔大鼠30只,体重180~220 g.随机分成3组:高骨转换率组,低骨转换率组,正常对照组.前2组通过20 d甲状腺片和丙硫氧嘧啶灌胃得到高骨转换率和低骨转换率组动物模型.左侧上颌第一磨牙加力21d.在处死动物前15d及2d添加骨标志物.拍X线片测量牙齿移动距离及牙根长度.结果:高骨转换率组的大鼠正畸牙齿移动的距离长,牙根最长.结论:骨转换率对正畸牙齿移动量及牙根吸收有影响.骨转换率高则大鼠牙齿移动量大,牙根吸收少,反之大鼠牙齿移动量小,牙根吸收多.

  5. Biochemical Markers of Joint Tissue Turnover

    DEFF Research Database (Denmark)

    Bay-Jensen, Anne-Christine; Sondergaard, Bodil Cecilie; Christiansen, Claus;

    2009-01-01

    available for the study of tissue turnover in each of the three compartments of the articular joint, that is the bone, the cartilage, and the synovium. Finally, we provide some perspective to future developments in biomarker discovery and discuss the potential impact such technologies could have on the drug...

  6. Mutagenicity testing with transgenic mice. Part I: Comparison with the mouse bone marrow micronucleus test

    OpenAIRE

    Wahnschaffe U; Bitsch A; Kielhorn J; Mangelsdorf I

    2005-01-01

    Abstract As part of a larger literature study on transgenic animals in mutagenicity testing, test results from the transgenic mutagenicity assays (lacI model; commercially available as the Big Blue® mouse, and the lacZ model; commercially available as the Muta™Mouse), were compared with the results on the same substances in the more traditional mouse bone marrow micronucleus test. 39 substances were found which had been tested in the micronucleus assay and in the above transgenic mouse system...

  7. The chloride channel inhibitor NS3736 [corrected] prevents bone resorption in ovariectomized rats without changing bone formation

    DEFF Research Database (Denmark)

    Schaller, Sophie; Henriksen, Kim; Sveigaard, Christina;

    2004-01-01

    Chloride channel activity is essential for osteoclast function. Consequently, inhibition of the osteoclastic chloride channel should prevent bone resorption. Accordingly, we tested a chloride channel inhibitor on bone turnover and found that it inhibits bone resorption without affecting bone form...

  8. Plutonium, 90Sr and 241Am in human bones from southern and northeastern parts of Poland

    International Nuclear Information System (INIS)

    The paper presents the results of our study on 238Pu, 239Pu, 240Pu, 241Am and 90Sr concentration in human bones carried out on a set of 88 individual samples of central Europe origin. Bone tissue samples were retrieved under surgery while introducing hip joint implants. The conducted surgeries tend to cover either southern or northeastern parts of Poland. While for the southern samples only global fallout was expected to be seen, a mixed global and Chernobyl fallout were to be reflected in the others. Alpha spectrometry was applied to obtain activity concentration for 238Pu, 239+240Pu, 241Am, while liquid scintillation spectrometry for 90Sr and mass spectrometry to receive 240Pu/239Pu mass ratio. Surprisingly enough, and to the contrary to our expectations we could not see any significant differences in either Pu activity or Pu mass ratio between the studied populations. In both populations Chernobyl fraction proved marginal. The results on 90Sr and 241Am confirm similarities between the two examined groups. (author)

  9. Mutagenicity testing with transgenic mice. Part I: Comparison with the mouse bone marrow micronucleus test

    Directory of Open Access Journals (Sweden)

    Wahnschaffe U

    2005-01-01

    Full Text Available Abstract As part of a larger literature study on transgenic animals in mutagenicity testing, test results from the transgenic mutagenicity assays (lacI model; commercially available as the Big Blue® mouse, and the lacZ model; commercially available as the Muta™Mouse, were compared with the results on the same substances in the more traditional mouse bone marrow micronucleus test. 39 substances were found which had been tested in the micronucleus assay and in the above transgenic mouse systems. Although, the transgenic animal mutation assay is not directly comparable with the micronucleus test, because different genetic endpoints are examined: chromosome aberration versus gene mutation, the results for the majority of substances were in agreement. Both test systems, the transgenic mouse assay and the mouse bone marrow micronucleus test, have advantages and they complement each other. However, the transgenic animal assay has some distinct advantages over the micronucleus test: it is not restricted to one target organ and detects systemic as well as local mutagenic effects.

  10. The effect of short-term low-energy ultraviolet B irradiation on bone mineral density and bone turnover markers in postmenopausal women with osteoporosis: A randomized single-blinded controlled clinical trial

    OpenAIRE

    Micić Ivan; Jeon In-Ho; Park So-Hyun; Hwa Seo-Sung; Chun Jae-Myeung; Stojiljković Predrag

    2013-01-01

    Introduction. The importance of vitamin D on bone health and osteoporosis was studied by many researchers. The main role of the Vitamin D is to absorb calcium and phosphate and increase bone mineralization. Older people are at an increased risk of the inadequate vitamin D production in the skin because of lower sun exposure and reduced ability of the skin to synthesize vitamin D. Objective. The aim of this clinical trial was to evaluate the efficacy and tolerability of short-term (2 wee...

  11. 绝经后妇女维生素D缺乏伴不同PTH水平对骨转换和骨量影响的相关性研究%The effects of vitamin D deficiency on bone turnover and bone mineral density in patients with different PTH responses in postmenopausal women

    Institute of Scientific and Technical Information of China (English)

    杜艳萍; 朱汉民; 李慧林; 朱晓颖; 洪维; 张雪梅; 薛思红; 程群

    2013-01-01

    Objective To investigate the effects of vitamin D deficiency on bone turnover and bone mineral density in patients with a blunted PTH response as compared to patients with vitamin D deficiency and secondary hyperparathyroidism.Method A total of 542 postmenopausal women [mean age (64.0 ± 10.8) years] were evaluated by assessing serum calcium,phosphate,alkaline phosphatase,25-hydroxy vitamin D (25-OHD),PTH,bone turnover markers such as osteocalcin,C-terminal telopeptide of type Ⅰ collagen(CTX) and procollagen type Ⅰ amino-terminal propeptide(PINP),and bone mineral density of lumber spine,total hip and femur neck etc.Result (1) The prevalence of vitamin D deficiency in this cohort was 24%.Mean 25-OHD varied across seasons (P =0.023) ; women who paid visits during winter and spring yielded significantly lower levels of 25-OHD than those who had their visit during the fall (P =0.012 and P =0.039).Serum PTH and bone turnover markers did not vary by season.(2) All subjects could be divided into four groups occording to their serum 25-OHD and PTH levels.Group 1:25-OHD< 10 ng/ml and PTH ≥ 65 pg/ml (7.0%),group 2:25-OHD < 10 ng/ml and PTH < 65 pg/ml (17.0%),group 3:25-OHD ≥ 10 ng/ml and PTH<65 pg/ml (73.6%),group 4:25-OHD ≥ 10 ng/ml and PTH ≥ 65 pg/ml (2.4%).Blunted PTH response was found in 70.8% of patients with vitamin D deficiency.Patients with vitamin D deficiency and a blunted PTH response were characterized by a lowered serum calcium,a reduction in bone turnover (serum CTX and serum osteocalcin),but protection in bone density as compared to those with vitamin D deficiency and secondary hyperparathyroidism.(3) As for spine bone mineral density,the significant independent predictors were body mass index(r2 =0.370,P<0.01),age(r2 =-0.158,P<0.01),PTH(r2 =-0.121,P<0.05),and serum CTX(r2 =-0.118,P<0.05).For femoral neck bone mineral density,the significant independent predictors were years since menopause(r2 =-0.201,P<O.01) and body

  12. Graves病患者骨质疏松患病情况及骨转换指标特征%Osteoporosis in Graves′ disease and the characteristics of bone turnover markers

    Institute of Scientific and Technical Information of China (English)

    黄灵; 李晓牧; 凌雁; 高鑫

    2011-01-01

    Objective To evaluate osteoporosis and the bone turnover markers in patients with Graves′ disease(GD) and the association of bone turnover markers including serum osteocalcin ( OCN ),I procollagen Nterminal propeptide( PINP),serum alkaline phosphatase ( ALP),and β- I collagen carboxyl-terminal peptide ( β-CTX)with thyroid hormone levels.Methods A total of 163 patients with Graves′ disease were enrolled.Serum thyroid hormone,OCN,PINP,and β-CTX levels were measured by the method of ethchemiluminescence.Serum ALP,calcium,phosphorus,and urinary calcium/creatinine ratio were measured by automatic biochemical system.Bone mineral density ( BMD ) of lumbar spines 1-4 ( L 1-4 ) and the proximal left femur was detected by dual energy xray absorptiometry.Results GD cases enrolled were composed of 43 men (26.4% )and 120 women ( 73.6% ),with an average age of ( 47 ± 1 ) years.There were 126 cases ( 77.3% ) with normal BMD,and 37 cases ( 22.7% ) with osteoporosis.OCN,ALP,PINP,β-CTX,and free T3 levels were significantly higher in the group of osteoporosis than those in the group with normal BMD( P<0.05 or P<0.01 ) after adjusting for sex,age,and BMI.The levels of OCN,P1NP,and β-CTX were positively correlated with serum FT3 level ( all P<0.01 ) and were also progressively increased according to the quartile groups of FT3 levels ( P<0.01 ) after sex,age,and BMI were adjusted.Conclusion Patients with Graves′ disease had a high incidence of osteoporosis with characristic high rate of bone turnover,which is related to the raised thyroid hormone levels.%目的 探讨Graves病(GD)患者骨质疏松的患病情况,研究GD患者血清骨钙素、Ⅰ型前胶原氨基端前肽(PINP)、血清碱性磷酸酶(ALP)、β-Ⅰ型胶原羧基端肽(β-CTX)等骨转换指标的特征及其与甲状腺激素水平的相关性.方法 人选明确诊断GD患者163例,电化学发光法测定甲状腺相关激素水平、骨钙素、PINP、CTX,全自动生化仪测定ALP

  13. Metals for bone implants. Part 1. Powder metallurgy and implant rendering.

    Science.gov (United States)

    Andani, Mohsen Taheri; Shayesteh Moghaddam, Narges; Haberland, Christoph; Dean, David; Miller, Michael J; Elahinia, Mohammad

    2014-10-01

    New metal alloys and metal fabrication strategies are likely to benefit future skeletal implant strategies. These metals and fabrication strategies were looked at from the point of view of standard-of-care implants for the mandible. These implants are used as part of the treatment for segmental resection due to oropharyngeal cancer, injury or correction of deformity due to pathology or congenital defect. The focus of this two-part review is the issues associated with the failure of existing mandibular implants that are due to mismatched material properties. Potential directions for future research are also studied. To mitigate these issues, the use of low-stiffness metallic alloys has been highlighted. To this end, the development, processing and biocompatibility of superelastic NiTi as well as resorbable magnesium-based alloys are discussed. Additionally, engineered porosity is reviewed as it can be an effective way of matching the stiffness of an implant with the surrounding tissue. These porosities and the overall geometry of the implant can be optimized for strain transduction and with a tailored stiffness profile. Rendering patient-specific, site-specific, morphology-specific and function-specific implants can now be achieved using these and other metals with bone-like material properties by additive manufacturing. The biocompatibility of implants prepared from superelastic and resorbable alloys is also reviewed.

  14. 短期 VLCD干预对超重肥胖患者骨代谢影响的研究%Effects of a short-term very low carbohydrate diet intervention on bone turnover ofoverweight and obese subjects

    Institute of Scientific and Technical Information of China (English)

    林晨; 郑和昕; 张微; 单晶; 赵小红; 王霞

    2016-01-01

    目的:探讨短期极低碳水化合物饮食(VLCD )干预对超重肥胖患者骨代谢指标的影响。方法:将205例超重或肥胖受试者以1:3比例随机分配至“单纯生活方式干预组”(对照组)和“单纯生活方式加VLCD干预组”(干预组)。比较2种不同干预方式在干预前后体重、体重指数(BMI )、腰围及甲状旁腺素(PTH )、β胶原特殊序列(β-CTx )、总N端骨钙素(TNOC )、I型前胶原氨基端延长肽(P1NP )、25-羟化维生素D3[25-(OH )-D3]的变化。结果:2种不同干预方式在干预后体重、BM I、腰围均较干预前明显下降,但VLCD治疗组在干预后下降较对照组明显( P<0.01)。2组干预前后骨代谢指标变化差异无统计学意义( P>0.05)。结论:短期VLCD护理对超重肥胖患者体重、BMI、腰围明显改善,对骨代谢指标总体无明显影响。%Objective] To investigate the effects of a short -term very low carbohydrate diet (VLCD) intervention on bone turnover of overweight and obese subjects .[Method] A total of 205 overweight or obese subjects were recruited and random-ized into control group and treatmeat groupwith a ratio of 1:3 .The control group received medical lifestyle intervention ,while the intervention group received very low carbohydrate diet intervention in addition to medical lifestyle intervention .Body weight , waist circumstance ,BMI ,Parathyroid hormone(PTH) ,β-crosslaps(β-CTx) ,N-terminal osteocalcin (TNOC) ,total pro-collagen I type N-terminal propeptide (P1NP ) and 25-OH-D3of each subjectwere measuredbefore and after the interven-tion .[Result] The body weight ,BMI and waist circumstancewere significantly decreased in the both groups ,butshowed more significantdecreasein the VLCD intervention group ( P0.05) .[Conclusion]Short-term very low carbohydrate diet intervention can improve body weight ,BMI and waist circumstance in overweight or obese subjects

  15. 新生适于胎龄儿骨转换标志物与骨声波传导速度的关系%Relationship between bone turnover markers and bone sound of speed in appropriate-for-gestational-age neonates

    Institute of Scientific and Technical Information of China (English)

    贺鸣凤; 陈平洋; 赵亚凡; 赵子艳

    2013-01-01

    Objective To investigate the correlation of gestational age (GA) with carboxyterminal propeptide of type Ⅰ procollagen (PICP),deoxypyridinoline (DPD),and bone sound of speed (SOS) in appropriate-for-gestational-age (AGA) neonates,as well as the relationship between bone turnover markers and bone SOS.Methods Sixtyfive AGA neonates were included in the study.The neonates were divided into three groups:preterm infant (GA ≤ 34 weeks,14 cases),late preterm infant (34 weeks<GA<37 weeks,13 cases),and full-term infant (GA ≥ 37 weeks,38 cases).Birth weight and length were measured in all cases,and Ponderal index (PI) was used to estimate their nutritional status.Venous blood was collected within 7 days after birth to measure blood PICP concentration.Urine was collected to measure urinary DPD and creatinine (Cr) levels.Omnisense 7000P ultrasound bone sonometer was applied to measure the SOS of the left tibia in all cases within 7 days after birth.Results There were significant differences in GA (F=140.199,P<0.001),birth weight (F=47.042,P<0.001),birth length (F=46.877,P<0.001),and PI (F=11.898,P<0.001) between the three groups; the higher the GA,the higher the birth weigh,birth length,and PI.There were significant differences in PICP (F=30.384,P<0.001),DPD/Cr (F=21.761,P<0.001),and SOS (F=20.052,P<0.001) between the three groups; the higher the GA,the lower the PICP and DPD/Cr and the higher the bone SOS.PICP and DPD/Cr were negatively correlated with GA,birth weight and bone SOS (P<0.01),while bone SOS was positively correlated with GA and birth weight (P<0.01),which still held true after adjustment for GA and birth weight.Conclusions Among AGA neonates,bone turnover markers are negatively correlated with GA,birth weight and bone SOS.High bone turnover is bad for bone health in AGA neonates.%目的 研究新生适于胎龄儿Ⅰ型前胶原羧基端前肽(PICP)、尿脱氧吡啶啉(DPD)及骨声波的传导速度(SOS)随胎龄变化的规律,探

  16. Effect of Microstructure of Spongy Bone in Different Parts of Woodpecker’s Skull on Resistance to Impact Injury

    Directory of Open Access Journals (Sweden)

    Lizhen Wang

    2013-01-01

    Full Text Available Natural biological materials such as bone, teeth and nacre are nano-composites of protein and mineral frequently exhibit highly superior strength for self-assembly and nanofabrication. Mineral mass and microstructure/nanostructure of bone are susceptible to stimulation by mechanical loads, ensuring that its mechanical behavior and strength are adapted to environmental changes. Woodpeckers repeatedly drum tree trunks at a speed of 6-7 m s−1 and acceleration of ~1000 g with no head injuries. The uneven distribution of spongy bone has been founded on woodpecker's skull in our previous study. More knowledge of the distribution of the shock-absorbing spongy bone could be incorporated into the design of new safety helmets, sports products, and other devices that need to be able to resist the impact. In this study, the effect of microstructure of spongy bone in different parts on woodpecker’s skull compared with other birds was observed and analyzed. It was found that the unique coordinate ability of micro-parameters in different parts of woodpecker’s skull could be one of the most important roles of its resistance to impact injury. Better understanding of the materials would provide new inspirations of shock-absorbing composite materials in engineering.

  17. Bone metabolism during pregnancy.

    Science.gov (United States)

    Salles, Jean Pierre

    2016-06-01

    During pregnancy, mineral concentrations, of calcium and phosphorus in particular, are maintained at a high level in fetal blood so that the developing skeleton may accrete adequate mineral content. The placenta actively transports minerals for this purpose. Maternal intestinal absorption increases in order to meet the fetal demand for calcium, which is only partly dependent on calcitriol. Mineral regulation is essentially dependent on parathyroid hormone (PTH) and PTH-related protein (PTHrP). The calcium-sensing receptor (CaSR) regulates PTH and PTHrP production. If calcium intake is insufficient, the maternal skeleton will undergo resorption due to PTHrP. After birth, a switch from fetal to neonatal homeostasis occurs through increase in PTH and calcitriol, and developmental adaptation of the kidneys and intestines with bone turnover contributing additional mineral to the circulation. Calcium absorption becomes progressively active and dependent on calcitriol. The postnatal skeleton can transiently present with osteoposis but adequate mineral diet usually allows full restoration. Cases of primary osteoporosis must be identified. Loss of trabecular mineral content occurs during lactation in order to provide calcium to the newborn. This programmed bone loss is dependent on a "brain-breast-bone" circuit. The physiological bone resorption during reproduction does not normally cause fractures or persistent osteoporosis. Women who experience fracture are likely to have other causes of bone loss. PMID:27157104

  18. Circuit modeling of the electrical impedance: part III. Disuse following bone fracture

    International Nuclear Information System (INIS)

    Multifrequency measurements of the electrical impedance of muscle have been extended to the study of disuse following bone fracture, and analyzed using the five-element circuit model used earlier in the study of the effects of disease. Eighteen subjects recovering from simple fractures on upper or lower limbs were examined (ten males, eight females, aged 18–66). Muscles on uninjured contralateral limbs were used as comparison standards, and results are presented in terms of the ratios p(injured)/p(uninjured), where p stands for the circuit parameter r1, r2, r3, 1/c1 or 1/c2. These are strikingly similar to the diseased-to-healthy ratios for patients with neuromuscular disease, reported in part I of this series. In particular, r1 is virtually unaffected and the ratios for r2, r3, 1/c1 and 1/c2 can be as large as in serious disease. Furthermore, the same pattern of relationships between the parameters is found, suggesting that there is a common underlying mechanism for the impedance changes. Atrophy and fibrosis are examined as candidates for that mechanism, but it is argued that their effects are too small to explain the observed changes. Fundamental considerations aside, the sensitivity, reproducibility and technical simplicity of the technique recommend its use for in-flight assessments of muscles during orbital or interplanetary missions. (paper)

  19. Regional alterations in long bone produced by internal fixation devices. Part I. 85Sr clearance

    International Nuclear Information System (INIS)

    We examined the effect of rigid plate application on the radiostrontium clearance of the intact canine femur at 6 months. We examined each of the component surgical steps. We calculated the clearance both for the whole bone and for each of the five transverse sections of the whole bone. Screw application, but not drilling, increased the clearance in the segment about the screw holes. Plate application produced an increase in the segment beneath the plate as well as around the screws and in the whole bone. These changes are accomplished not only by an absolute increase in clearance to the middle three segments, but by a relative diminution in clearance by the most proximal and distal segments. The histomorphometric changes in long bones following rigid plating may be accompanied by regional increases in bone blood flow

  20. The rate of calcium turnover in bone

    International Nuclear Information System (INIS)

    This paper reports an analysis of the clearance of calcium-47 tracer from the plasma of human patients. Nine subjects have so far been analysed, and the results all deviate somewhat from those predicted from the conventional simple kinetic scheme. 3 figs

  1. Correlations among biochemical markers of bone turnover,bone speed of sound and postnatal age in early infancy%婴儿早期骨代谢生化指标与声波速度值和出生后年龄间的关系

    Institute of Scientific and Technical Information of China (English)

    廖祥鹏; 张立; 卫雅蓉; 张伟利; 何稼敏; 孙建华; 黄萍

    2009-01-01

    目的 探讨婴儿早期骨代谢生化指标与声波速度值和出生后年龄间的关系.方法 采用骨定量超声(QUS)仪对167例出生3月内的婴儿进行胫骨声波速度(SOS)测量.其中包括53例早产儿(胎龄:32.6±2.7周)和114例足月儿(胎龄:39.1±1.2周);同时在部分婴儿中测量血钙、磷、碱性磷酸酶(ALP)和骨碱性磷酸酶(BALP).结果 ①早产儿和足月儿的血钙、磷、ALP和BALP值之间均差异无显著性.②婴儿骨SOS值与ALP呈显著负相关(n=167,r=-0.139,P=0.036)、与BALP也显著负相关(n=32,r=-0.410,P=0.010);SOS值与血钙、血磷及血钙磷乘积无显著性相关.在早产儿中,ALP和BALP与日龄均显著相关,相关系数r分别为0.286(n=53,P=0.019)和0.946(n=7,P=0.001);在足月儿中未发现显著相关性.血磷与日龄呈显著负相关(n=24,r=-0.509,P=0.005).③ALP与BALP高度相关(n=32,r=0.958,P=0.001),BALP占ALP活力的47.3%.早产儿在出生时BALP和Ⅰ型胶原羧基端肽(IcTP)显著正相关(n=36,r=0.768,P=0.001).结论 定量超声技术测量SOS有助于我们评估婴儿早期骨状况;在此横向研究中我们发现骨SOS与骨代谢生化指标之间存在相关性,然而,二者间的纵向关系有待于进一步研究.%Objective To examine the correlations among biochemical markers of bone turnover,bone speed of sound and postnatal age in early infancy. Materials and methods: A quantitative ultrasound bone sonometer was used to measure the bone speed of sound (SOS) of the tibia in 167 infants within 3 months of birth, including 53 preterm infants (gestational age 32.6±2.7 weeks) and 114 full-term infants (gestational age 39.1±1.2 weeks). Serum calcium, phosphorus, bone alkaline phosphatase (ALP), bone alkaline phosphatase (BALP) were examined at the same time among some of them. Results: 1) There were no significant differences of serum calcium, phosphorus, ALP and BALP between preterm infants and full-term infants. 2) There were significantly inverse

  2. Predicting Turnover Intentions and Turnover Behavior: A Multivariate Analysis.

    Science.gov (United States)

    Parasuraman, Saroj

    1982-01-01

    Assessed the relative influence of personal, attitudinal, and behavioral variables on behavioral intentions and voluntary turnover among nonsupervisory plant workers. Results show that personal variables have little direct effect on turnover; rather, their influence on turnover is channeled through their effects on behavioral intentions. (Author)

  3. Bone Metabolism in Adolescents with Anorexia Nervosa

    OpenAIRE

    Misra, Madhusmita; Klibanski, Anne

    2011-01-01

    Adolescents with anorexia nervosa (AN) are at risk for low bone mass at multiple sites, associated with decreased bone turnover. Bone microarchitecture is also affected, with a decrease in bone trabecular volume and trabecular thickness, and an increase in trabecular separation. The adolescent years are typically the time when marked increases occur in bone mass accrual towards the attainment of peak bone mass, an important determinant of bone health and fracture risk in later life. AN often ...

  4. Severe Bone Loss as Part of the Life History Strategy of Bowhead Whales.

    Science.gov (United States)

    George, John C; Stimmelmayr, Raphaela; Suydam, Robert; Usip, Sharon; Givens, Geof; Sformo, Todd; Thewissen, J G M

    2016-01-01

    The evolution of baleen constituted a major evolutionary change that made it possible for baleen whales to reach enormous body sizes while filter feeding on tiny organisms and migrating over tremendous distances. Bowhead whales (Balaena mysticetus) live in the Arctic where the annual cycle of increasing and decreasing ice cover affects their habitat, prey, and migration. During the nursing period, bowheads grow rapidly; but between weaning and approximately year 5, bowhead whales display sustained baleen and head growth while limiting growth in the rest of their bodies. During this period, they withdraw resources from the skeleton, in particular the ribs, which may lose 40% of bone mass. Such dramatic changes in bones of immature mammals are rare, although fossil cetaceans between 40 and 50 million years ago show an array of rib specializations that include bone loss and are usually interpreted as related to buoyancy control. PMID:27333180

  5. Severe Bone Loss as Part of the Life History Strategy of Bowhead Whales.

    Directory of Open Access Journals (Sweden)

    John C George

    Full Text Available The evolution of baleen constituted a major evolutionary change that made it possible for baleen whales to reach enormous body sizes while filter feeding on tiny organisms and migrating over tremendous distances. Bowhead whales (Balaena mysticetus live in the Arctic where the annual cycle of increasing and decreasing ice cover affects their habitat, prey, and migration. During the nursing period, bowheads grow rapidly; but between weaning and approximately year 5, bowhead whales display sustained baleen and head growth while limiting growth in the rest of their bodies. During this period, they withdraw resources from the skeleton, in particular the ribs, which may lose 40% of bone mass. Such dramatic changes in bones of immature mammals are rare, although fossil cetaceans between 40 and 50 million years ago show an array of rib specializations that include bone loss and are usually interpreted as related to buoyancy control.

  6. Severe Bone Loss as Part of the Life History Strategy of Bowhead Whales

    Science.gov (United States)

    George, John C.; Stimmelmayr, Raphaela; Suydam, Robert; Usip, Sharon; Givens, Geof; Sformo, Todd; Thewissen, J. G. M.

    2016-01-01

    The evolution of baleen constituted a major evolutionary change that made it possible for baleen whales to reach enormous body sizes while filter feeding on tiny organisms and migrating over tremendous distances. Bowhead whales (Balaena mysticetus) live in the Arctic where the annual cycle of increasing and decreasing ice cover affects their habitat, prey, and migration. During the nursing period, bowheads grow rapidly; but between weaning and approximately year 5, bowhead whales display sustained baleen and head growth while limiting growth in the rest of their bodies. During this period, they withdraw resources from the skeleton, in particular the ribs, which may lose 40% of bone mass. Such dramatic changes in bones of immature mammals are rare, although fossil cetaceans between 40 and 50 million years ago show an array of rib specializations that include bone loss and are usually interpreted as related to buoyancy control. PMID:27333180

  7. Bone ingrowth on the surface of endosseous implants. Part 2: Theoretical and numerical analysis

    OpenAIRE

    Moreo, Pedro; García-Aznar, J.M. José Manuel; Doblaré, Manuel

    2009-01-01

    Abstract The study of osseointegration of endosseous implants is a matter of great interest, mostly due to the increase in the use of many types of implants in clinical practice. Bone ingrowth results from a complex process, in which mechanics and biology play a major role. A wide variety of diverse factors can affect the development of the process, such as the properties or geometry of the implant surface, the mechanical stimulation or the initial cell conditions. In the first par...

  8. Airway allergen exposure stimulates bone marrow eosinophilia partly via IL-9

    Directory of Open Access Journals (Sweden)

    Johansson Anna-Karin

    2005-04-01

    Full Text Available Abstract Background Interleukin (IL-9 is a Th2-derived cytokine with pleiotropic biological effects, which recently has been proposed as a candidate gene for asthma and allergy. We aimed to evaluate the therapeutic effect of a neutralizing anti-IL-9 antibody in a mouse model of airway eosinophilic inflammation and compared any such effect with anti-IL-5 treatment. Methods OVA-sensitized Balb/c mice were intraperitoneally pretreated with a single dose (100 μg of an anti-mouse IL-9 monoclonal antibody (clone D9302C12 or its vehicle. A third group was given 50 μg of a monoclonal anti-mouse IL-5 antibody (TRFK-5 or its vehicle. Animals were subsequently exposed to OVA on five days via airways. Newly produced eosinophils were labelled using 5-bromo-2'-deoxyuridine (BrdU. BrdU+ eosinophils and CD34+ cell numbers were examined by immunocytochemistry. After culture and stimulation with OVA or PMA+IC, intracellular staining of IL-9 in bone marrow cells from OVA-exposed animals was measured by Flow Cytometry. The Mann-Whitney U-test was used to determine significant differences between groups. Results Anti-IL-9 significantly reduced bone marrow eosinophilia, primarily by decrease of newly produced (BrdU+ and mature eosinophils. Anti-IL-9 treatment also reduced blood neutrophil counts, but did not affect BAL neutrophils. Anti-IL-5 was able to reduce eosinophil numbers in all tissue compartments, as well as BrdU+ eosinophils and CD34+ progenitor cells, and in all instances to a greater extent than anti-IL-9. Also, FACS analysis showed that IL-9 is over-expressed in bone marrow CD4+ cells after allergen exposure. Conclusions Our data shows that a single dose of a neutralizing IL-9 antibody is not sufficient to reduce allergen-induced influx of newly produced cells from bone marrow to airways. However, in response to allergen, bone marrow cells over-express IL-9. This data suggest that IL-9 may participate in the regulation of granulocytopoiesis in allergic

  9. What causes the positive price-turnover correlation in European housing markets?

    OpenAIRE

    Dröes, Martijn I.; Marc K. Francke

    2016-01-01

    This paper examines what determines the correlation between prices and turnover in European housing markets. Using a panel vector autoregressive model, we find that there is a particularly strong feedback mechanism between prices and turnover. Momentum effects are another important reason why prices and turnover are correlated. Common underlying factors, such as GDP and interest rates, also explain part of the price-turnover correlation. The results in this paper imply that, to understand pri...

  10. Bone-seeking radiopharmaceuticals for treatment of osseous metastases, Part 1: α therapy with 223Ra-dichloride.

    Science.gov (United States)

    Pandit-Taskar, Neeta; Larson, Steven M; Carrasquillo, Jorge A

    2014-02-01

    Metastatic disease to bone is commonly seen in the advanced stages of many cancers. The cardinal symptom, pain, is often the cause of significant morbidity and reduced quality of life. Treatment of bone pain includes nonsteroidal analgesics and opiates; however, long-term use of these drugs is commonly associated with significant side effects, and tolerance is common. External-beam radiation therapy is effective mainly in localized disease sites. Bone-targeting radiopharmaceuticals are beneficial in the management of patients with multiple metastatic lesions. This article focuses on the 3 most commonly used agents: the Food and Drug Administration-approved (89)Sr-chloride, (153)Sm-ethylenediaminetetramethylene phosphonic acid (EDTMP), and (223)Ra-dichloride. We will discuss the physical characteristics, clinical data, dosage, and administration of these agents, including optimal patient selection and toxicity associated with their use. These radioactive agents have proven efficacy in the treatment of painful osseous metastases from prostate cancer and breast cancer. Significant recent advances include use of these agents in combination with chemotherapy and the use of the α emitter (223)Ra-dichloride in prostate cancer, primarily to improve survival and skeletal related events. The review is presented in 2 parts. The first will discuss the characteristics and clinical use of (223)Ra-dichloride, and the second will discuss the β emitters (89)Sr and (153)Sm-EDTMP.

  11. Infant formula increases bone turnover favoring bone formation

    Science.gov (United States)

    In the first year of life, the major infant food choices have traditionally been breast milk (BM), cow's milk formula (MF), or soy formula (SF). Studies examining the effects of infant formula on early life skeletal development are extremely limited. We have enrolled 120 healthy 6-month-old infants ...

  12. Bone mineral mass and bone turnover parameters in osteoporosis

    NARCIS (Netherlands)

    R.J. Erdtsieck (Ronald)

    1996-01-01

    textabstractIn the past decades osteoporosis has been recognized as an important public health problem. Several causes for this problem can be pointed out. The most probable cause for the development of osteoporosis is the loss of ovarian function in women and the increasing age of people, thereby i

  13. Voluntary turnover, volatility in voluntary turnover, and labor productivity.

    OpenAIRE

    Van Beveren, Ilke; Vanormelingen, Stijn; De Winne, Sophie; Sels, Luc

    2012-01-01

    Voluntary turnover is a frequently studied employee outcome in articles on the relationship between HRM and firm performance. The main assumption underlying these articles is “less voluntary turnover is better”. Recent research questioned this assumption and showed that the relationship between turnover and firm performance might be more complex than assumed thus far in strategic HRM literature. The purpose of this article is to add to the discussion and unravel this complex relationship. Bas...

  14. CEO Turnover in Reverse Splits

    OpenAIRE

    Li-Hsun Wang; Chu-Hsiung Lin; Hsien-Ming Chen

    2010-01-01

    This study examines the application of CEO turnover on reverse stock splits firms. Using Taiwanese samples, we find that non-CEO turnover firms receive negative long-term abnormal returns, and their financial performances continue to decline following reverse splits. These findings are consistent with prior studies. Contrarily, neither significantly negative long-term abnormal returns nor changes on financial performance were found for CEO turnover firms. This study concludes that applying CE...

  15. Bone Appetit: The Role of Food and Nutrition in Building and Maintaining Strong Bones

    Science.gov (United States)

    Bone is a living, dynamic, metabolically active tissue. It under goes a process of constant renewal throughout life, through a process called bone turnover in which cells called osteoclasts remove old or damaged bone, and cells called osteoblasts make new bone to replace it. A healthy, balanced di...

  16. Integrating Turnover Reasons and Shocks with Turnover Decision Processes

    Science.gov (United States)

    Maertz, Carl P., Jr.; Kmitta, Kayla R.

    2012-01-01

    We interviewed and classified 186 quitters from many jobs and organizations via a theoretically-based protocol into five decision process types. We then tested exploratory hypotheses comparing users of these types on their propensity to report certain turnover reasons and turnover shocks. "Impulsive-type quitters," with neither a job offer in hand…

  17. How Employee Turnover Affects Productivity

    DEFF Research Database (Denmark)

    Eriksen, Bo

    Research on employee turnover suggests that turnover results in negative organization-level outcomes. This paper provides a firm-level analysis of the impact of the in- and outflows of human resources on productivity and how the presence of organizational slack resources moderates the effects...

  18. Commitment Profiles and Employee Turnover

    Science.gov (United States)

    Stanley, Laura; Vandenberghe, Christian; Vandenberg, Robert; Bentein, Kathleen

    2013-01-01

    We examined how affective (AC), normative (NC), perceived sacrifice (PS), and few alternatives (FA) commitments combine to form profiles and determine turnover intention and turnover. We theorized that three mechanisms account for how profiles operate, i.e., the degree to which membership is internally regulated, the perceived desirability and…

  19. Regional alterations in long bone 85Sr clearance produced by internal fixation devices. Part II. Histomorphometry

    International Nuclear Information System (INIS)

    The effects of each of the surgical stages involved in compression plating on the development of cortical thinning and porosity were assessed in the intact midshaft, stress-shielded femoral segments of adult mongrel dogs 6 months postoperatively. The data were evaluated in terms of a postsurgical tetracycline-based measure of remodeling and terminal 85Sr clearance (SrC) values for the plated segments of bone. Drilling had no effect on any parameter. Screw application was associated with minimal cortical thinning (p less than 0.05), while plate fixation clearly promoted thinning (p less than 0.01) and porosity (p less than 0.05). The percentage of labeled osteons, a measure of remodeling activity, increased only after plate fixation (p less than 0.05), and the labeling patterns suggested that most osteons had formed during the first 4 postsurgical months. That none of these changes were correlated with the 6-month SrC values suggests that the development of plate-induced osteopenia involves disparate histomorphometric time constants, rather than lack of any association

  20. Patterns of Practice of Palliative Radiotherapy in Africa, Part 1: Bone and Brain Metastases

    International Nuclear Information System (INIS)

    Purpose: To provide data on the pattern of practice of palliative radiotherapy (RT) on the African continent. Methods and Materials: A questionnaire was distributed to participants in a regional training course of the International Atomic Energy Agency in palliative cancer care and sent by e-mail to other institutions in Africa. Requested information included both infrastructure and human resources available and the pattern of RT practice for metastatic and locally advanced cancers. Results: Of 35 centers contacted, 24 (68%) completed the questionnaire. Although RT is used by most centers for most metastatic cancers, liver and lung metastases are treated with chemotherapy. Of 23 centers, 14 (61%) had a single RT regimen as an institutional policy for treating painful bone metastases, but only 5 centers (23%) of 23 used 8 Gy in 1 fraction. Brain metastases were being treated by RT to the whole brain to 30 Gy in 10 fractions, either exclusively (n = 13, 56%) or in addition to the use of 20 Gy in 5 fractions (n = 3, 14%). Conclusion: Radiotherapy is a major component of treatment of cancer patients in African countries. There is consensus among few centers for treatment schedules for almost all sites regarding time and dose-fractionation characteristics of RT regimens used and/or indications for the use of RT in this setting

  1. How Employee Turnover Affects Productivity

    DEFF Research Database (Denmark)

    Eriksen, Bo

    Research on employee turnover suggests that turnover results in negative organization-level outcomes. This paper provides a firm-level analysis of the impact of the in- and outflows of human resources on productivity and how the presence of organizational slack resources moderates the effects...... of employee turnover. Drawing on a unique longitudinal dataset of 2,926 Danish manufacturing firms that combine individual-level data with firm-level data, the paper shows that job turnover has a substantial negative effect on total productivity but that the firm’s size, its capital intensity, and its age...... moderate this effect so that the negative consequences of employee turnover are less severe for larger, older and capital intensive firms. These moderating variables indicate the presence of slack resources in the firm, and thus that the accumulation of slack reduces the efficiency losses from employee...

  2. Managing voluntary turnover through challenging assignments

    NARCIS (Netherlands)

    Preenen, P.T.Y.; Pater, I.E. de; Vianen, A.E.M. van; Keijzer, L.

    2011-01-01

    This study examines employees' challenging assignments as manageable means to reduce turnover intentions, job search behaviors, and voluntary turnover. Results indicate that challenging assignments are negatively related to turnover intentions and job search behaviors and that these relationships ar

  3. From bone to plausible bipedal locomotion. Part II: Complete motion synthesis for bipedal primates.

    Science.gov (United States)

    Nicolas, Guillaume; Multon, Franck; Berillon, Gilles

    2009-05-29

    This paper addresses the problem of synthesizing plausible bipedal locomotion according to 3D anatomical reconstruction and general hypotheses on human motion control strategies. In a previous paper [Nicolas, G., Multon, F., Berillon, G., Marchal, F., 2007. From bone to plausible bipedal locomotion using inverse kinematics. Journal of Biomechanics 40 (5) 1048-1057], we have validated a method based on using inverse kinematics to obtain plausible lower-limb motions knowing the trajectory of the ankle. In this paper, we propose a more general approach that also involves computing a plausible trajectory of the ankles for a given skeleton. The inputs are the anatomical descriptions of the bipedal species, imposed footprints and a rest posture. This process is based on optimizing a reference ankle trajectory until a set of criteria is minimized. This optimization loop is based on the assumption that a plausible motion is supposed to have little internal mechanical work and should be as less jerky as possible. For each tested ankle trajectory, inverse kinematics is used to compute a lower-body motion that enables us to compute the resulting mechanical work and jerk. This method was tested on a set of modern humans (male and female, with various anthropometric properties). We show that the results obtained with this method are close to experimental data for most of the subjects. We also demonstrate that the method is not sensitive to the choice of the reference ankle trajectory; any ankle trajectory leads to very similar result. We finally apply the method to a skeleton of Pan paniscus (Bonobo), and compare the resulting motion to those described by zoologists.

  4. Characterization of wear in composite material orthopaedic implants. Part II: The implant/bone interface.

    Science.gov (United States)

    Albert, K; Schledjewski, R; Harbaugh, M; Bleser, S; Jamison, R; Friedrich, K

    1994-01-01

    Carbon fiber/PEEK polymer (C/PEEK) composite materials are being developed for use as orthopaedic implant materials. Wear is an issue of increasing importance in orthopaedic implants; particulate debris generated by the wearing of biomaterials may be a causal factor leading to osteolysis and implant loosening. Therefore, numerical and experimental studies were completed to characterize the wear of C/PEEK composite materials in comparison to current orthopaedic implant materials. Finite element analyses (FEA) of a composite material hip stem implanted in a femur and loaded at 890 N determined that peak contact stresses will occur at the proximal-medial and distal regions of the implant. These contact stresses were found to be below 1.0 MPa over most of the implant surface; however the peak stress in the proximal-medial region was 1.8 MPa and higher still at the distal portion of the stem. In vivo forces result in contact stress values up to 9.0 MPa. The composite implant exhibited 10-40% lower contact stresses in the distal region compared to a titanium-alloy implant of identical design. Composite material wear samples were slid against porous hydroxylapatite (HA) to simulate the stem/bone interface. An identical series of experiments was run for comparison to a current orthopaedic implant material--Ti6A14V titanium alloy. Two domains of motion were studied; a composite ring-on-HA disc large amplitude sliding wear test; and a composite pin-on-HA disc small amplitude fretting regimen. Nominal contact pressures during testing were 1.4 MPa and 7.6 MPa for sliding and fretting tests, respectively. Fretting and sliding abrasive wear tests resulted in the composite material exhibiting a lower wear rate than the titanium-alloy. The magnitude of the difference was greatly dependent on the contact pressures, sliding amplitudes, and counterface material properties.

  5. How Is Bone Cancer Diagnosed?

    Science.gov (United States)

    ... with bone cancer. Accurate diagnosis of a bone tumor often depends on combining information about its location (what bone is affected and even which part of the bone is involved), appearance on x-rays, and appearance under a microscope. ...

  6. Biglycan deficiency interferes with ovariectomy-induced bone loss

    DEFF Research Database (Denmark)

    Nielsen, Karina L; Allen, Matthew R; Bloomfield, Susan A;

    2003-01-01

    Biglycan is a matrix proteoglycan with a possible role in bone turnover. In a 4-week study with sham-operated or OVX biglycan-deficient or wildtype mice, we show that biglycan-deficient mice are resistant to OVX-induced trabecular bone loss and that there is a gender difference in the response to...... in bone, where it may modulate both formation and resorption ultimately influencing the bone turnover process....

  7. Biomass turnover time in terrestrial ecosystems halved by land use

    Science.gov (United States)

    Erb, Karl-Heinz; Fetzel, Tamara; Plutzar, Christoph; Kastner, Thomas; Lauk, Christian; Mayer, Andreas; Niedertscheider, Maria; Körner, Christian; Haberl, Helmut

    2016-09-01

    The terrestrial carbon cycle is not well quantified. Biomass turnover time is a crucial parameter in the global carbon cycle, and contributes to the feedback between the terrestrial carbon cycle and climate. Biomass turnover time varies substantially in time and space, but its determinants are not well known, making predictions of future global carbon cycle dynamics uncertain. Land use--the sum of activities that aim at enhancing terrestrial ecosystem services--alters plant growth and reduces biomass stocks, and is hence expected to affect biomass turnover. Here we explore land-use-induced alterations of biomass turnover at the global scale by comparing the biomass turnover of the actual vegetation with that of a hypothetical vegetation state with no land use under current climate conditions. We find that, in the global average, biomass turnover is 1.9 times faster with land use. This acceleration affects all biomes roughly equally, but with large differences between land-use types. Land conversion, for example from forests to agricultural fields, is responsible for 59% of the acceleration; the use of forests and natural grazing land accounts for 26% and 15% respectively. Reductions in biomass stocks are partly compensated by reductions in net primary productivity. We conclude that land use significantly and systematically affects the fundamental trade-off between carbon turnover and carbon stocks.

  8. Cytoplasmic reactive oxygen species and SOD1 regulate bone mass during mechanical unloading.

    Science.gov (United States)

    Morikawa, Daichi; Nojiri, Hidetoshi; Saita, Yoshitomo; Kobayashi, Keiji; Watanabe, Kenji; Ozawa, Yusuke; Koike, Masato; Asou, Yoshinori; Takaku, Tomoiku; Kaneko, Kazuo; Shimizu, Takahiko

    2013-11-01

    Oxidative stress contributes to the pathogenesis of age-related diseases as well as bone fragility. Our previous study demonstrated that copper/zinc superoxide dismutase (Sod1)-deficient mice exhibit the induction of intracellular reactive oxygen species (ROS) and bone fragility resulting from low-turnover bone loss and impaired collagen cross-linking (Nojiri et al. J Bone Miner Res. 2011;26:2682-94). Mechanical stress also plays an important role in the maintenance of homeostasis in bone tissue. However, the molecular links between oxidative and mechanical stresses in bone tissue have not been fully elucidated. We herein report that mechanical unloading significantly increased intracellular ROS production and the specific upregulation of Sod1 in bone tissue in a tail-suspension experiment. We also reveal that Sod1 loss exacerbated bone loss via reduced osteoblastic abilities during mechanical unloading. Interestingly, we found that the administration of an antioxidant, vitamin C, significantly attenuated bone loss during unloading. These results indicate that mechanical unloading, in part, regulates bone mass via intracellular ROS generation and the Sod1 expression, suggesting that activating Sod1 may be a preventive strategy for ameliorating mechanical unloading-induced bone loss.

  9. Employment Turnover and Unemployment Insurance

    OpenAIRE

    Hassler, John; Vicente Rodríguez Mora, José

    1997-01-01

    Two features distinguish European and US labour markets. First, most European countries have a considerably more generous unemployment insurance system. Second, the duration of unemployment and employment spells are substantially higher in Europe – employment turnover is lower. We show that self-insurance, i.e. saving and borrowing, is a good substitute for unemployment insurance when turnover is as high as in the United States. If the insurance system is less than perfectly actuarially fair,...

  10. Talking Bones.

    Science.gov (United States)

    Johnson, Jaclyn; Kassing, Sharon

    2002-01-01

    Describes cooperation with the Saint Louis Zoo to provide opportunities for elementary school students to learn about bones, how animals move, what they eat, and how much they grow. Uses biofacts which include bones, skulls, and other parts to make the laboratory a hands-on experience for students. (YDS)

  11. Imaging Diagnosis of Aneurysmal Bone Cyst at Rare Parts Bone%不规则骨原发性动脉瘤样骨囊肿的影像评价

    Institute of Scientific and Technical Information of China (English)

    陈利军; 陈文静; 杜建平

    2015-01-01

    Objective To improve imaging diagnosis of aneurysmal bone cyst at rare parts bone. Methods 29 cases with aneurysmal bone cyst confirmed by surgery and pathology were analyzed retrospectively. Of the 29 cases,9 cases occurred in irregular bone,5 cases of occipital,2 case of pubic, 2 case of sacrum.;20 cases occurred in regular bone, 11 case for humerus,9 case for femur. Results The major imaging signs of the 29 cases of aneurysmal bone cyst located at flat bone and irregular bone were:1、Soap bubble-like expensive bone destruction was detected by X-ray in 7 cases, by CT in 18 cases, and by MRI in 19 cases; 2、Bone trabeculae mixed with osseousseptae in the lesion were detected by X-ray in 3 cases, by CT in 7 cases, and by MRI in 3 cases;3、Local sclerosis of the bony structure adjacent to the lesion was detected by X-ray in 0 cases, by CT in 3 cases, and by MRI in 15 cases;4、Partial pathologic fractures of bone shells were detected by X-ray in 2 cases;by CT in 5 cases, and by MRI in 1 cases;5、Fluid-fluid level inside the lesion was detected by CT in 2 cases, by MRI in 20 cases; 6、No periosteal reaction; 7、Soft tissue mass was detected by CT in 0 case, by MRI in 1 case. Conclusion The imaging characteristics of aneurysmal bone cyst at flat bone and irregular bone are similar to that at long-tubular bone, DSCT and MRI can distinctly improve the correct rate of diagnosis.%目的:提高对不规则骨原发性动脉瘤样骨囊肿影像学表现的认识。方法回顾性分析经手术病理证实的29例骨原发性动脉瘤样骨囊肿的影像表现。其中9例发生于不规则骨,20例发生于规则骨。结果29例原发性动脉瘤样骨囊肿主要影像表现:1、皂泡状或吹气球样膨胀性骨质破坏:平片7例,CT 18例,MRI 19例;2、病灶内骨间隔及骨脊:平片3例, CT 7例; MRI 3例;3、病灶周围骨或纤维组织硬化:平片0例, CT 3例, MRI表现为病灶周围线状低信号影15例;4

  12. Business Ethics & Employee Turnover: CAFE Matrix

    OpenAIRE

    Sapovadia, Vrajlal; Patel, Sweta

    2013-01-01

    Abstract: Business ethics is in discussion for its importance universally, so is the employee turnover in business. Unethical practices are unwanted, so is the high employee turnover. Unethical practices and high employee turnover in business is ubiquitous. No consensus exists on defining ethics. Employee turnover is well defined, but there is no consensus on when employee turnover is disadvantageous for the company. The Golden Rule or ethic of reciprocity, a maxim states that either ...

  13. Immersed Turnovers In Hyperbolic 3-Orbifolds

    OpenAIRE

    Rafalski, Shawn

    2007-01-01

    We show that any immersion, which is not a covering of an embedded 2-orbifold, of a totally geodesic hyperbolic turnover in a complete orientable hyperbolic 3-orbifold is contained in a hyperbolic 3-suborbifold with totally geodesic boundary, called the "turnover core,'' whose volume is bounded from above by a function depending only on the area of the given turnover. Furthermore, we show that, for a given type of turnover, there are only finitely many possibilities for the turnover core. As ...

  14. Government Turnover : Concepts, Measures and Applications

    OpenAIRE

    Horowitz, S; Hoff, K.; Milanovic, B.

    2009-01-01

    While government turnover is often thought of as an adverse source of instability, it may also be viewed as a favourable source of competition and institution-building. To articulate and test such hypotheses, this article describes two main concepts of government turnover: leadership turnover, or change in rulers, and ideological turnover, or change in the rulers' ideology. Refinements involve the mode, outcome and timing of turnover. The article discusses measurement issues that arise when t...

  15. Adynamic Bone Decreases Bone Toughness During Aging by Affecting Mineral and Matrix.

    Science.gov (United States)

    Ng, Adeline H; Omelon, Sidney; Variola, Fabio; Allo, Bedilu; Willett, Thomas L; Alman, Benjamin A; Grynpas, Marc D

    2016-02-01

    Adynamic bone is the most frequent type of bone lesion in patients with chronic kidney disease; long-term use of antiresorptive therapy may also lead to the adynamic bone condition. The hallmark of adynamic bone is a loss of bone turnover, and a major clinical concern of adynamic bone is diminished bone quality and an increase in fracture risk. Our current study aims to investigate how bone quality changes with age in our previously established mouse model of adynamic bone. Young and old mice (4 months old and 16 months old, respectively) were used in this study. Col2.3Δtk (DTK) mice were treated with ganciclovir and pamidronate to create the adynamic bone condition. Bone quality was evaluated using established techniques including bone histomorphometry, microcomputed tomography, quantitative backscattered electron imaging, and biomechanical testing. Changes in mineral and matrix properties were examined by powder X-ray diffraction and Raman spectroscopy. Aging controls had a natural decline in bone formation and resorption with a corresponding deterioration in trabecular bone structure. Bone turnover was severely blunted at all ages in adynamic animals, which preserved trabecular bone loss normally associated with aging. However, the preservation of trabecular bone mass and structure in old adynamic mice did not rescue deterioration of bone mechanical properties. There was also a decrease in cortical bone toughness in old adynamic mice that was accompanied by a more mature collagen matrix and longer bone crystals. Little is known about the effects of metabolic bone disease on bone fracture resistance. We observed an age-related decrease in bone toughness that was worsened by the adynamic condition, and this decrease may be due to material level changes at the tissue level. Our mouse model may be useful in the investigation of the mechanisms involved in fractures occurring in elderly patients on antiresorptive therapy who have very low bone turnover. PMID:26332924

  16. Mentoring and turnover intentions in public accounting firms: a research note

    OpenAIRE

    Hall, Matthew; Smith, David

    2009-01-01

    Turnover in public accounting firms is a critically important issue as firms seek to retain quality accounting personnel in the face of skilled labour shortages. Mentoring is one initiative that has been suggested as a means of reducing the high costs associated with employee turnover. However, prior accounting research examining the association between mentoring and turnover intentions has produced mixed results, which may be due, at least in part, to difficulties in operationalizing the men...

  17. Investigations of Diabetic Bone Disease

    DEFF Research Database (Denmark)

    Linde, Jakob Starup

    Diabetes mellitus is associated with an increased risk of fracture with and current fracture predictors underestimate fracture risk in both type 1 and type 2 diabetes. Thus, further understanding of the underlying causes of diabetic bone disease may lead to better fracture predictors and preventive...... measures in patients with diabetes. This PhD thesis reports the results of two systematic reviews and a meta-analysis, a state-of-the-art intervention study, a clinical cross-sectional study and a registry-based study all examining the relationship between diabetes, glucose, and bone. Patients with type 2...... diabetes had lower bone turnover markers compared to patients with type 1 diabetes and bone mineral density and tissue stiffness were increased in patients with type 2 diabetes. The bone turnover markers were inversely associated with blood glucose in patients with diabetes and both an oral glucose...

  18. CEO Turnover and Market Reaction in Indonesia

    Directory of Open Access Journals (Sweden)

    Doddy Setiawan

    2013-07-01

    Full Text Available This research examines Chief Executive Officer (CEO turnover and market reaction in Indonesia. The sample of this research consists of 213 CEO turnover announcements for Indonesia Stock Exchange during 2000–2010 period. T-tests were used to investigate the effect of CEO turnover announcement on abnormal stock return during the event windows periods. The results of this research show that there is positive reaction on the CEO turnover announcements. This research considers both routine and non routine CEO turnover processes. This research finds that both turnover processes have information content to investor. This research also finds positive reaction on the announcements of outsider incoming CEO, while investors do not react on the announcement of insider incoming CEO. Thus, this research provides evidence that CEO turnover announcement have information content.   Keywords: CEO turnover, stock price, turnover process, the origin of incoming CEO

  19. Job turnover and labor turnover : a taxonomy of employment dynamics

    NARCIS (Netherlands)

    Hassink, Wolter H.J.; Hamermesh, Daniel S.

    1994-01-01

    We present an organized set of stylized facts on the relations among flows of workers,changes in employment and changes in the numer of jobs at the firm level. Job turnover isusually measured by comparing stocks of employment in each firm at two points in time andadding up the absolute employment ch

  20. Analisis Hubungan Receivable Turnover Ratio, Inventory Turnover Ratio, dan Total Asset Turnover Ratio Dengan Kemampulabaan Perusahaan Pada PTPN III (Persero) Medan

    OpenAIRE

    Panjaitan, Fitry Bertha H.

    2010-01-01

    Tujuan penelitian adalah untuk menganalisis hubungan Receivable Turnover Ratio, Inventory Turnover Ratio, dan Total Asset Turnover Ratio dengan kemampulabaan perusahaan pada PTPN III (Persero) Medan. Penulis menarik hipotesis bahwa Receivable Turnover Ratio, Inventory Turnover Ratio, dan Total Asset Turnover Ratio berhubungan positif dengan kemampulabaan perusahaan pada PTPN III (Persero) Medan. Metode penelitian yang digunakan adalah metode analisis deskriptif dan metode analisis K...

  1. Low turnover osteoporosis in sheep induced by hypothalamic-pituitary disconnection.

    Science.gov (United States)

    Beil, Frank Timo; Oheim, Ralf; Barvencik, Florian; Hissnauer, Tim N; Pestka, Jan M; Ignatius, Anita; Rueger, Johannes M; Schinke, Thorsten; Clarke, Iain J; Amling, Michael; Pogoda, Pia

    2012-08-01

    The hypothalamus is of critical importance in regulating bone remodeling. This is underscored by the fact that intracerebroventricular-application of leptin in ewe leads to osteopenia. As a large animal model of osteoporosis, this approach has some limitations, such as high technical expenditure and running costs. Therefore we asked if a surgical ablation of the leptin signaling axis would have the same effects and would thereby be a more useful model. We analyzed the bone phenotype of ewe after surgical hypothalamo-pituitary disconnection (HPD + OVX) as compared to control ewe (OVX) after 3 and 12 months. Analyses included histomorphometric characterization, micro-CT and measurement of bone turnover parameters. Already 3 months after HPD we found osteopenic ewe with a significantly decreased bone formation (69%) and osteoclast activity (49%). After a period of 12 months the HPD group additionally developed an (preclinical) osteoporosis with significant reduction (33%) of femoral cortical thickness, as compared to controls (OVX). Taken together, HPD leads after 12 month to osteoporosis with a reduction in both trabecular and cortical bone caused by a low bone turnover situation, with reduced osteoblast and osteoclast activity, as compared to controls (OVX). The HPD-sheep is a suitable large animal model of osteoporosis. Furthermore our results indicate that an intact hypothalamo-pituitary axis is required for activation of bone turnover.

  2. The effect of bone allografts combined with bone marrow stromal cells on the healing of segmental bone defects in a sheep model

    OpenAIRE

    Fernandes, Marco Bernardo C; Guimarães, João Antônio Matheus; Casado, Priscila Ladeira; Cavalcanti, Amanda dos Santos; Gonçalves, Natalia N; Carlos E. Ambrósio; Rodrigues, Fernando; Pinto, Ana Carolina F; Miglino, Maria Angélica; Duarte, Maria Eugênia L.

    2014-01-01

    Background The repair of large bone defects is a major orthopedic challenge because autologous bone grafts are not available in large amounts and because harvesting is often associated with donor-site morbidity. Considering that bone marrow stromal cells (BMSC) are responsible for the maintenance of bone turnover throughout life, we investigated bone repair at a site of a critically sized segmental defect in sheep tibia treated with BMSCs loaded onto allografts. The defect was created in the ...

  3. Migration Turnover Rates in Mountain States Counties

    OpenAIRE

    Israelsen, William J.; Israelsen, L. Dwight; Israelsen, Ryan D.

    2006-01-01

    Studies of migration typically examine migration between countries, or, in the United States, migration between states. Recently, there have been several studies done on the determinants of migration at the county level. The current study introduces a new concept into the migration literature: the migration turnover rate (MTR). The migration turnover rate is similar to an employee turnover rate in that it measures the turnover through in-migration and out-migration of the population of an are...

  4. Migration Turnover Rates in United States Counties

    OpenAIRE

    Israelsen, L. Dwight; Israelsen, Ryan D.; Israelsen, William J.

    2006-01-01

    Studies of migration typically examine migration between countries, or, in the United States, migration between states. Recently, there have been several studies done on the determinants of migration at the county level. The current study introduces a new concept into the migration literature: the migration turnover rate (MTR). The migration turnover rate is similar to an employee turnover rate in that it measures the turnover through in-migration and out-migration of the population of an are...

  5. Estimating Teacher Turnover Costs: A Case Study

    Science.gov (United States)

    Levy, Abigail Jurist; Joy, Lois; Ellis, Pamela; Jablonski, Erica; Karelitz, Tzur M.

    2012-01-01

    High teacher turnover in large U.S. cities is a critical issue for schools and districts, and the students they serve; but surprisingly little work has been done to develop methodologies and standards that districts and schools can use to make reliable estimates of turnover costs. Even less is known about how to detect variations in turnover costs…

  6. Using Turnover as a Recruitment Strategy

    Science.gov (United States)

    Duncan, Sandra

    2009-01-01

    Teacher turnover is notoriously high in the field of early childhood education with an estimated 33% of staff exiting the workplace each year. Turnover is costly. Not only do high levels of turnover negatively impact children's growth and development, it also erodes the program's economic stability and wherewithal to provide effective operations…

  7. A Spectral Model of Turnover Reduction

    OpenAIRE

    Zura Kakushadze

    2014-01-01

    We give a simple explicit formula for turnover reduction when a large number of alphas are traded on the same execution platform and trades are crossed internally. We model turnover reduction via alpha correlations. Then, for a large number of alphas, turnover reduction is related to the largest eigenvalue and the corresponding eigenvector of the alpha correlation matrix.

  8. How Teacher Turnover Harms Student Achievement

    Science.gov (United States)

    Ronfeldt, Matthew; Loeb, Susanna; Wyckoff, James

    2013-01-01

    Researchers and policymakers often assume that teacher turnover harms student achievement, though recent studies suggest this may not be the case. Using a unique identification strategy that employs school-by-grade level turnover and two classes of fixed-effects models, this study estimates the effects of teacher turnover on over 850,000 New York…

  9. Increasing turnover through time in tropical forests

    OpenAIRE

    Phillips, O. L; Gentry, A.H.

    1994-01-01

    Tree turnover rates were assessed at 40 tropical forest sites. Averaged across inventoried forests, turnover, as measured by tree mortality and recruitment, has increased since the 1950's, with an apparent pantropical acceleration since 1980. Among 22 mature forest sites with two or more inventory periods, forest turnover also increased. The trend in forest dynamics may have profound effects on biological diversity.

  10. Benchmarking of homogeneous electrocatalysts: overpotential, turnover frequency, limiting turnover number.

    Science.gov (United States)

    Costentin, Cyrille; Passard, Guillaume; Savéant, Jean-Michel

    2015-04-29

    In relation to contemporary energy challenges, a number of molecular catalysts for the activation of small molecules, mainly based on transition metal complexes, have been developed. The time has thus come to develop tools allowing the benchmarking of these numerous catalysts. Two main factors of merit are addressed. One involves their intrinsic catalytic performances through the comparison of "catalytic Tafel plots" relating the turnover frequency to the overpotential independently of the characteristics of the electrochemical cell. The other examines the effect of deactivation of the catalyst during the course of electrolysis. It introduces the notion of the limiting turnover number as a second key element of catalyst benchmarking. How these two factors combine with one another to control the course of electrolysis is analyzed in detail, leading to procedures that allow their separate estimation from measurements of the current, the charge passed, and the decay of the catalyst concentration. Illustrative examples from literature data are discussed. PMID:25757058

  11. Reader's digest of the pathophysiology of bone metastases.

    Science.gov (United States)

    Gruber, Reinhard

    2012-09-01

    Bone metastases are a process originally proposed as the "seed and soil theory" in the eighteenth century. Tumor cell disseminating from patients with breast or prostate cancer typically use the bony environment to grow outside the primary tumor location. The severe clinical consequences of bone metastasis such as pain, fractures, and hypercalcemia result from a serious misbalance of bone turnover. Most bone metastases cause catabolic changes of bone turnover. The severity of bone resorption is associated with tumor growth, suggesting the existence of a vicious cycle that needs to be interrupted. Osteoblastic metastasis showing signs of osteosclerotic lesions are observed in prostate cancer. Understanding the pathophysiology of bone metastases and their detrimental consequence provide the scientific basis for therapeutic interventions at various levels including homing of tumors to bone, survival and growth of the tumor cell in the bone niche, and the mechanisms causing bone destruction. PMID:22797871

  12. From bone to breast and back - the bone cytokine RANKL and breast cancer

    OpenAIRE

    Hofbauer, Lorenz C; Rachner, Tilman D; Hamann, Christine

    2011-01-01

    Receptor activator of nuclear factor-κB ligand (RANKL) plays a pivotal role in regulating bone homeostasis. Osteoporosis and malignant bone disease secondary to breast cancer are characterized by enhanced RANKL production and increased bone turnover. Thus, denosumab, a monoclonal antibody to RANKL, has been developed and is now approved for various bone loss conditions. Recent results indicate that RANKL may also promote the development and osseous migration of breast cancer.

  13. Calvarial doughnut lesions associated with high-turnover osteoporosis presenting in childhood.

    Science.gov (United States)

    Stock, J L; Coderre, J A; Overdorf, J H; Fitzpatrick, L A; Shapiro, J R

    1999-01-01

    Osteogenesis imperfecta and juvenile osteoporosis are two well-described syndromes of osteoporosis presenting in childhood. There are also several references in the radiology literature to calvarial doughnut lesions (CDLs), areas of radiolucency surrounded by a dense and well-defined area of sclerotic bone, either as an incidental finding or associated with childhood fracture. We have characterized the metabolic abnormalities in a 13-yr-old boy with CDLs and multiple fractures and followed him during his progression through puberty. The patient's paternal grandmother; father; and paternal aunt, uncle, and first cousin were similarly affected, and a mandibular lesion in the uncle was pathologically described as fibrous dysplasia. The subject's physical examination was significant for bony protuberances of the skull and normal hearing, sclearal hue, dentition, and joint flexibility. Radiographs revealed calvarial CDLs and osteopenia which was confirmed by bone mineral density (BMD) testing. Biochemical markers of bone formation and resorption were elevated compared to normal adult and a transiliac crest bone biopsy confirmed high-turnover osteoporosis. Over 6 yr, with no specific therapy, BMD gradually normalized, but the CDLs increased in size, bone turnover remained elevated by biochemical markers, and he continued to fracture. The subject's affected father and maternal grandmother had normal BMD and no history of adult fracture. CDLs with high-turnover osteoporosis should be considered in the differential diagnosis of pediatric osteoporosis. During puberty the BMD normalizes but the high-turnover state persists, and the propensity to fracture eventually decreases in older affected adults. The CDLs may be a variant of fibrous dysplasia, and further study is necessary in order to elucidate the stimulus for increased bone turnover and the familial nature of this syndrome. PMID:23547313

  14. Managing employee turnover in China

    OpenAIRE

    Rinne, Tuua

    2013-01-01

    OBJECTIVES OF THE STUDY: Many international companies are facing challenges in retaining their top talent in the Chinese talent war. This single case study provides a description on how voluntary employee turnover is managed in a Chinese subsidiary of a Finnish multinational enterprise. First objective of this study aims at explaining why Chinese employees stay in or leave the company. The second goal is to analyze how multicultural context affect the adoption of different retention pract...

  15. Turnover: strategies for staff retention.

    Science.gov (United States)

    SnowAntle, S

    1990-01-01

    This discussion has focused on a number of areas where organizations may find opportunities for more effectively managing employee retention. Given the multitude of causes and consequences, there is no one quick fix. Effective management of employee retention requires assessment of the entire human resources process, that is, recruitment, selection, job design, compensation, supervision, work conditions, etc. Regular and systematic diagnosis of turnover and implementation of multiple strategies and evaluation are needed (Mobley, 1982). PMID:10106673

  16. Bone tumor

    Science.gov (United States)

    Tumor - bone; Bone cancer; Primary bone tumor; Secondary bone tumor ... The cause of bone tumors is unknown. They often occur in areas of the bone that grow rapidly. Possible causes include: Genetic defects ...

  17. Mathematical modeling of bone marrow--peripheral blood dynamics in the disease state based on current emerging paradigms, part I.

    Science.gov (United States)

    Afenya, Evans K; Ouifki, Rachid; Camara, Baba I; Mundle, Suneel D

    2016-04-01

    Stemming from current emerging paradigms related to the cancer stem cell hypothesis, an existing mathematical model is expanded and used to study cell interaction dynamics in the bone marrow and peripheral blood. The proposed mathematical model is described by a system of nonlinear differential equations with delay, to quantify the dynamics in abnormal hematopoiesis. The steady states of the model are analytically and numerically obtained. Some conditions for the local asymptotic stability of such states are investigated. Model analyses suggest that malignancy may be irreversible once it evolves from a nonmalignant state into a malignant one and no intervention takes place. This leads to the proposition that a great deal of emphasis be placed on cancer prevention. Nevertheless, should malignancy arise, treatment programs for its containment or curtailment may have to include a maximum and extensive level of effort to protect normal cells from eventual destruction. Further model analyses and simulations predict that in the untreated disease state, there is an evolution towards a situation in which malignant cells dominate the entire bone marrow - peripheral blood system. Arguments are then advanced regarding requirements for quantitatively understanding cancer stem cell behavior. Among the suggested requirements are, mathematical frameworks for describing the dynamics of cancer initiation and progression, the response to treatment, the evolution of resistance, and malignancy prevention dynamics within the bone marrow - peripheral blood architecture. PMID:26877072

  18. Exploring correlation between bone metabolism markers and densitometric traits in extended families from Spain.

    Science.gov (United States)

    Athanasiadis, Georgios; Arranz, Laura; Ziyatdinov, Andrey; Brunel, Helena; Camacho, Mercedes; Malouf, Jorge; Sosa, Nerea Hernandez-de; Vila, Luis; Casademont, Jordi; Soria, Jose Manuel

    2016-09-01

    Osteoporosis is a common multifactorial disorder characterized by low bone mass and reduced bone strength that may cause fragility fractures. In recent years, there have been substantial advancements in the biochemical monitoring of bone metabolism through the measurement of bone turnover markers. Currently, good knowledge of the genetics of such markers has become an indispensable part of osteoporosis research. In this study, we used the Genetic Analysis of Osteoporosis Project to study the genetics of the plasma levels of 12 markers related to bone metabolism and osteoporosis. Plasma phenotypes were determined through biochemical assays and log-transformed values were used together with a set of covariates to model genetic and environmental contributions to phenotypic variation, thus estimating the heritability of each trait. In addition, we studied correlations between the 12 markers and a wide variety of previously described densitometric traits. All of the 12 bone metabolism markers showed significant heritability, ranging from 0.194 for osteocalcin to 0.516 for sclerostin after correcting for covariate effects. Strong genetic correlations were observed between osteocalcin and several bone mineral densitometric traits, a finding with potentially useful diagnostic applications. In addition, suggestive genetic correlations with densitometric traits were observed for leptin and sclerostin. Overall, the few strong and several suggestive genetic correlations point out the existence of a complex underlying genetic architecture for bone metabolism plasma phenotypes and provide a strong motivation for pursuing novel whole-genome gene-mapping strategies. PMID:27241279

  19. Comparative effects of dried plum and dried apple on bone in postmenopausal women.

    Science.gov (United States)

    Hooshmand, Shirin; Chai, Sheau C; Saadat, Raz L; Payton, Mark E; Brummel-Smith, Kenneth; Arjmandi, Bahram H

    2011-09-01

    Aside from existing drug therapies, certain lifestyle and nutritional factors are known to reduce the risk of osteoporosis. Among the nutritional factors, dried plum or prunes (Prunus domestica L.) is the most effective fruit in both preventing and reversing bone loss. The objective of the present study was to examine the extent to which dried plum reverses bone loss in osteopenic postmenopausal women. We recruited 236 women, 1-10 years postmenopausal, not on hormone replacement therapy or any other prescribed medication known to influence bone metabolism. Qualified participants (n 160) were randomly assigned to one of the two treatment groups: dried plum (100 g/d) or dried apple (comparative control). Participants received 500 mg Ca plus 400 IU (10 μg) vitamin D daily. Bone mineral density (BMD) of lumbar spine, forearm, hip and whole body was assessed at baseline and at the end of the study using dual-energy X-ray absorptiometry. Blood samples were collected at baseline, 3, 6 and 12 months to assess bone biomarkers. Physical activity recall and 1-week FFQ were obtained at baseline, 3, 6 and 12 months to examine physical activity and dietary confounders as potential covariates. Dried plum significantly increased BMD of ulna and spine in comparison with dried apple. In comparison with corresponding baseline values, only dried plum significantly decreased serum levels of bone turnover markers including bone-specific alkaline phosphatase and tartrate-resistant acid phosphatase-5b. The findings of the present study confirmed the ability of dried plum in improving BMD in postmenopausal women in part due to suppressing the rate of bone turnover.

  20. Manager's guide to reducing dental hygiene turnover.

    Science.gov (United States)

    Loiacono, C

    1989-09-01

    The purpose of this paper is to address the issue of dental hygiene turnover and provide managers with strategies for preventing and reducing turnover. Employee turnover is a problem which affects dental health care delivery and the health of the public. Employee turnover is costly to work settings and creates a stressful working environment which has an impact on professional-client relationships. To reduce or prevent turnover in a private practice setting, office managers must be informed about the causes and effects of this problem and be able to implement solutions. Some strategies managers can use to reduce turnover are hiring employees who have the same goals as the organization; improving the working climate; rewarding longevity; encouraging the active participation of all staff members in office management; improving office communication; and providing opportunities for self-growth, recognition, and greater responsibilities.

  1. Blueberry consumption prevents loss of collagen in bone matrix and inhibits senescence pathways in osteoblastic cells

    Science.gov (United States)

    Ovariectomy (OVX)-induced bone loss has been linked to increased bone turnover and higher bone matrix collagen degradation as the result of osteoclast activation. However, the role of degraded collagen matrix in the fate of resident bone-forming cells is unclear. In this report, we show that OVX-i...

  2. Structural adjustment, job turnover and career progression

    OpenAIRE

    Spiros Bougheas; Carl Davidson; Richard Upward; Peter Wright

    2015-01-01

    We develop a dynamic, stochastic, multi-sectoral, equilibrium model that allows for worker turnover, job turnover and career mobility. This serves to bridge the literatures on job reallocation and career progression. Our model makes a number of predictions: a positive correlation between job turnover rates and promotion rates; a positive correlation across sectors between mean real income and their corresponding variance; an inverse relationship between sector profitability and both the job t...

  3. Linking global turnover of species and environments

    OpenAIRE

    Buckley, Lauren B.; Jetz, Walter

    2008-01-01

    Patterns of species turnover are central to the geography of biodiversity and resulting challenges for conservation, but at broad scales remain relatively little understood. Here, we take a first spatially-explicitly and global perspective to link the spatial turnover of species and environments. We compare how major groups of vertebrate ectotherms (amphibians) and endotherms (birds) respond to spatial environmental gradients. We find that high levels of species turnover occur regardless of e...

  4. Bone histology in chronic kidney disease-related mineral and bone disorder.

    Science.gov (United States)

    Kazama, Junichiro James

    2011-06-01

    A quantitative histological analysis of biopsied bone samples is currently regarded as the gold standard for a diagnosing procedure for bone diseases associated with chronic kidney disease-related mineral and bone disorder. Conventionally, "bone cell activities" and "bone mineralization" are applied as two independent assessment axes, and the histology results are classified into five categories according to these axes. Recently, a new bone histology classification system called the Turnover-Mineralization-Volume system, which applied "cancellous bone volume" as another major assessing axis, was advocated; however, both classification systems have many unsolved problems. Clinicians must realize the limitations in evaluating bone metabolism by bone histology. We will need to establish a new classification method for renal bone diseases independent of histological findings.

  5. Age dependence of natural uranium and thorium concentrations in bone.

    Science.gov (United States)

    Larivière, Dominic; Packer, Ana Paula; Marro, Leonora; Li, Chunsheng; Chen, Jing; Cornett, R Jack

    2007-02-01

    The age dependence of the natural concentration of uranium and thorium in the skeleton was investigated using human vertebrae bone collected from two Canadian locations (Winnipeg, Manitoba, and Regina, Saskatchewan). The concentration of both radioelements in digested ashed bone samples was determined using sector-field inductively coupled plasma mass spectrometry. The geometric means for uranium level in bones showed a significant statistical difference between the two locations studied. Similarly for thorium, a statistical difference was observed, although this difference was considered marginal. The thorium concentration differed only marginally with respect to age group, indicating that its behavior in the body could be age-independent. Conversely, the uranium level in bones was found to change for the age groups tested, an indication of age-specific deposition. The age profile for uranium was comparable to the calcium turn-over rate, indicating that uranium deposition is probably, in part, dictated by this metabolic process, showing the role of present uptake into the uranium concentration in bones for populations exposed to significant uranium intake. PMID:17220713

  6. Dynamic Aspects of Voluntary Turnover: An Integrated Approach to Curvilinearity in the Performance-Turnover Relationship

    Science.gov (United States)

    Becker, William J.; Cropanzano, Russell

    2011-01-01

    Previous research pertaining to job performance and voluntary turnover has been guided by 2 distinct theoretical perspectives. First, the push-pull model proposes that there is a quadratic or curvilinear relationship existing between these 2 variables. Second, the unfolding model of turnover posits that turnover is a dynamic process and that a…

  7. Bone Biopsy

    Science.gov (United States)

    ... Physician Resources Professions Site Index A-Z Bone Biopsy Bone biopsy uses a needle and imaging guidance ... limitations of Bone Biopsy? What is a Bone Biopsy? A bone biopsy is an image-guided procedure ...

  8. Bone Diseases

    Science.gov (United States)

    ... avoid smoking and drinking too much alcohol. Bone diseases can make bones easy to break. Different kinds ... break Osteogenesis imperfecta makes your bones brittle Paget's disease of bone makes them weak Bones can also ...

  9. Pathophysiology of chronic kidney disease-mineral and bone disorder.

    Science.gov (United States)

    Mac Way, Fabrice; Lessard, Myriam; Lafage-Proust, Marie-Hélène

    2012-12-01

    Chronic kidney disease (CKD) alters the metabolism of several minerals, thereby inducing bone lesions and vessel-wall calcifications that can cause functional impairments and excess mortality. The histological bone abnormalities seen in CKD, known as renal osteodystrophy, consist of alterations in the bone turnover rate, which may be increased (osteitis fibrosa [OF]) or severely decreased (adynamic bone disease [AD]); abnormal mineralization (osteomalacia [OM]), and bone loss. Secondary hyperparathyroidism is related to early phosphate accumulation (responsible for FGF23 overproduction by bone tissue), decreased calcitriol production by the kidneys, and hypocalcemia. Secondary hyperparathyroidism is associated with OF. Other factors that affect bone include acidosis, chronic inflammation, nutritional deficiencies, and iatrogenic complications.

  10. Contextual Factors Related to Elementary Principal Turnover

    Science.gov (United States)

    Partlow, Michelle C.

    2007-01-01

    The issue of school leadership instability and how it affects schools and student achievement has been studied. The question of how to predict turnover of the principal remains an unknown. The purpose of this research was to search for possible relationships between certain contextual variables and principal turnover and to test the independent…

  11. Principal Turnover. Information Capsule. Volume 0914

    Science.gov (United States)

    Blazer, Christie

    2010-01-01

    Recent studies indicate that school districts are facing increasing rates of principal turnover. Frequent principal changes deprive schools of the leadership stability they need to succeed, disrupt long-term school reform efforts, and may even be linked to increased teacher turnover and lower levels of student achievement. This Information Capsule…

  12. Employee Turnover: Evidence from a Case Study.

    Science.gov (United States)

    Borland, Jeff

    1997-01-01

    Patterns of employee turnover from a medium-sized law firm in Australia were examined in regard to theories of worker mobility (matching, sectoral shift, and incentive). Results support a role for matching effects, but personnel practices affect the timing of turnover. Matching and incentive-based theories do not explain the high rates of turnover…

  13. Tibolone inhibits bone resorption without secondary positive effects on cartilage degradation

    Directory of Open Access Journals (Sweden)

    Byrjalsen I

    2008-11-01

    Full Text Available Abstract Background Osteoarthritis is associated with increased bone resorption and increased cartilage degradation in the subchondral bone and joint. The objective of the present study was to determine whether Tibolone, a synthetic steroid with estrogenic, androgenic, and progestogenic properties, would have similar dual actions on both bone and cartilage turnover, as reported previously with some SERMS and HRT. Methods This study was a secondary analysis of ninety-one healthy postmenopausal women aged 52–75 yrs entered a 2-yr double blind, randomized, placebo-controlled study of treatment with either 1.25 mg/day (n = 36, or 2.5 mg/day Tibolone (n = 35, or placebo (n = 20, (J Clin Endocrinol Metab. 1996 Jul;81(7:2419–22 Second void morning urine samples were collected at baseline, and at 3, 6, 12, and 24 months. Urine CrossLaps® ELISA (CTX-I and Urine CartiLaps® ELISA (CTX-II was investigated as markers of bone resorption and cartilage degradation, respectively. Results Tibolone significantly (P Conclusion These data suggest uncoupling of the bone and cartilage effects of the synthetic steroid, Tibolone. Bone resorption was significantly decreased, whereas cartilage degradation was unchanged. These effects are in contrast to those observed some SERMs with effects on both bone and cartilage degradation. These effects may in part be described by the complicated pharmacology of Tibolone on testosterone, estrogen and progesterone receptors.

  14. Chronic Teacher Turnover in Urban Elementary Schools

    Directory of Open Access Journals (Sweden)

    Kacey Guin

    2004-08-01

    Full Text Available This study examines the characteristics of elementary schools that experience chronic teacher turnover and the impacts of turnover on a school’s working climate and ability to effectively function. Based on evidence from staff climate surveys and case studies, it is clear that high turnover schools face significant organizational challenges. Schools with high teacher turnover rates have difficulty planning and implementing a coherent curriculum and sustaining positive working relationships among teachers. The reality of these organizational challenges is particularly alarming, given that high turnover schools are more likely to serve low-income and minority students. The negative relationship between teacher turnover and school functioning, and the fact that turbulent schools are disproportionately likely to serve lowincome and minority students have important implications for both district and school-level policies. Specifically: Teacher turnover rates are one indicator of school health, which school districts should consider when focusing on school improvements. Districts need to begin by developing the means to identify individual schools that experience high levels of teacher turnover. Current district policies in implementing professional development for teachers in low-performing schools are inefficient when teachers do not remain in the schools in which they are trained. In order for low-performing schools to improve, districts need to consider providing incentive programs so that high quality teachers apply for, and remain in, these schools. Future research is needed to address the causal link between turnover, organizational functioning and student outcomes. Additionally, there is a need for research examining district policies that may facilitate teacher turnover within a district, including how districts place and transfer teachers, as well as how teachers’ salaries are budgeted.

  15. System turnover and acceptance procedure of Qingshan NPP

    International Nuclear Information System (INIS)

    Turnover and acceptance process of nuclear power plant has direct influence on construction scheduling. The authors describe organization, conditions and implementation of system turnover and acceptance. The paper also gives some suggestions as reference of turnover and acceptance work

  16. Ichthyosaurs from the French Rhaetian indicate a severe turnover across the Triassic–Jurassic boundary

    OpenAIRE

    Fischer, Valentin; Cappetta, Henri; Vincent, Peggy; Garcia, Géraldine; Goolaerts, Stijn; Martin, Jérémy E.; Roggero, Daniel; Valentin, Xavier

    2014-01-01

    Mesozoic marine reptiles went through a severe turnover near the end of the Triassic. Notably, an important extinction event affected ichthyosaurs, sweeping a large part of the group. This crisis is, however, obscured by an extremely poor fossil record and is regarded as protracted over the entire Norian–earliest Jurassic interval, for the lack of a more precise scenario. The iconic whale-sized shastasaurid ichthyosaurs are regarded as early victims of this turnover, disappearing by the middl...

  17. Polyurethane/fluor-hydroxyapatite nanocomposite scaffolds for bone tissue engineering. Part I: morphological, physical, and mechanical characterization.

    Science.gov (United States)

    Asefnejad, Azadeh; Behnamghader, Aliasghar; Khorasani, Mohammad Taghi; Farsadzadeh, Babak

    2011-01-01

    In this study, new nano-fluor-hydroxyapatite (nFHA)/polyurethane composite scaffolds were fabricated for potential use in bone tissue engineering. Polyester urethane samples were synthesized from polycaprolactone, hexamethylene diisocyanate, and 1,4-butanediol as chain extender. Nano fluor-hydroxyapatite (nFHA) was successfully synthesized by sol-gel method. The solid-liquid phase separation and solvent sublimation methods were used for preparation of the porous composites. Mechanical properties, chemical structure, and morphological characteristics of the samples were investigated by compressive test, Fourier transform infrared, and scanning electron microscopy (SEM) techniques, respectively. The effect of nFHA powder content on porosity and pore morphology was investigated. SEM images demonstrated that the scaffolds were constituted of interconnected and homogeneously distributed pores. The pore size of the scaffolds was in the range 50-250 μm. The result obtained in this research revealed that the porosity and pore average size decreased and compressive modulus increased with nFHA percentage. Considering morphological, physical, and mechanical properties, the scaffold with a higher ratio of nFHA has suitable potential use in tissue regeneration.

  18. Polyurethane/fluor-hydroxyapatite nanocomposite scaffolds for bone tissue engineering. Part I: morphological, physical, and mechanical characterization

    Directory of Open Access Journals (Sweden)

    Azadeh Asefnejad

    2011-01-01

    Full Text Available Azadeh Asefnejad1, Aliasghar Behnamghader2, Mohammad Taghi Khorasani3, Babak Farsadzadeh11Department of Biomedical Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran; 2Materials and Energy Research Center, Tehran, Iran; 3Iran Polymer and Petrochemical Institute, Tehran, IranAbstract: In this study, new nano-fluor-hydroxyapatite (nFHA/polyurethane composite scaffolds were fabricated for potential use in bone tissue engineering. Polyester urethane samples were synthesized from polycaprolactone, hexamethylene diisocyanate, and 1,4-butanediol as chain extender. Nano fluor-hydroxyapatite (nFHA was successfully synthesized by sol-gel method. The solid–liquid phase separation and solvent sublimation methods were used for preparation of the porous composites. Mechanical properties, chemical structure, and morphological characteristics of the samples were investigated by compressive test, Fourier transform infrared, and scanning electron microscopy (SEM techniques, respectively. The effect of nFHA powder content on porosity and pore morphology was investigated. SEM images demonstrated that the scaffolds were constituted of interconnected and homogeneously distributed pores. The pore size of the scaffolds was in the range 50–250 µm. The result obtained in this research revealed that the porosity and pore average size decreased and compressive modulus increased with nFHA percentage. Considering morphological, physical, and mechanical properties, the scaffold with a higher ratio of nFHA has suitable potential use in tissue regeneration.Keywords: polyester urethane, composite, fluor-hydroxyapatite, scaffold

  19. The Research Progress and Prospect of Employee Turnover Intention

    OpenAIRE

    Somchit Hongvichit

    2015-01-01

    Employee turnover management is an important aspect of human resource management, how to effectively control and predict employee turnover becomes an important content of academic research. Related research results show that the turnover intention is employee turnover behavior of the most direct antecedents, can predict employee turnover behavior. The author reviews the employee turnover intention, the connotation of the antecedent variables and measurement, the future trend of development an...

  20. Turnover intention in new graduate nurses: a multivariate analysis

    OpenAIRE

    Beecroft, Pauline C; Dorey, Frederick; Wenten, Madé

    2008-01-01

    Title Turnover intention in new graduate nurses: a multivariate analysis Aim This paper is a report of a study to determine the relationship of new nurse turnover intent with individual characteristics, work environment variables and organizational factors and to compare new nurse turnover with actual turnover in the 18 months of employment following completion of a residency. Background Because of their influence on patient safety and health outcomes nurse turnover and turnover intent have r...

  1. Bone Metabolism and Arterial Stiffness After Renal Transplantation

    Directory of Open Access Journals (Sweden)

    Orsolya Cseprekál

    2014-11-01

    Full Text Available Background/Aims: To assess the relationship between bone and vascular disease and its changes over time after renal transplantation. Metabolic bone disease (MBD is common in chronic kidney disease (CKD and is associated with cardiovascular (CV disease. Following transplantation (Tx, improvement in CV disease has been reported; however, data regarding changes in bone disease remain controversial. Methods: Bone turnover and arterial stiffness (pulse wave velocity (PWV were assessed in 47 Tx patients (38 (3-191 months after Tx. Results: Bone alkaline phosphatase (BALP, osteocalcin (OC and beta-crosslaps were significantly higher in Tx patients, and decreased significantly after one year. There was a negative correlation between BALP, OC and steroid administered (r=-0.35;r=-0.36 respectively. PWV increased in the Tx group (1.15 SD. In patients with a follow up of Conclusions: Increased bone turnover and arterial stiffness are present following kidney transplantation. While bone turnover decreases with time, arterial stiffness correlates initially with bone turnover, after which the influence of cholesterol becomes significant. Non-invasive estimation of bone metabolism and arterial stiffness may help to assess CKD-MBD following renal transplantation.

  2. Rapid Cellular Turnover in Adipose Tissue

    OpenAIRE

    Alessandra Rigamonti; Kristen Brennand; Frank Lau; Cowan, Chad A.

    2011-01-01

    It was recently shown that cellular turnover occurs within the human adipocyte population. Through three independent experimental approaches — dilution of an inducible histone 2B-green fluorescent protein (H2BGFP), labeling with the cell cycle marker Ki67 and incorporation of BrdU — we characterized the degree of cellular turnover in murine adipose tissue. We observed rapid turnover of the adipocyte population, finding that 4.8% of preadipocytes are replicating at any time and that between 1–...

  3. The validation of the turnover intention scale

    Directory of Open Access Journals (Sweden)

    Chris F.C. Bothma

    2013-01-01

    Full Text Available Orientation: Turnover intention as a construct has attracted increased research attention in the recent past, but there are seemingly not many valid and reliable scales around to measure turnover intention.Research purpose: This study focused on the validation of a shortened, six-item version of the turnover intention scale (TIS-6.Motivation for the study: The research question of whether the TIS-6 is a reliable and a valid scale for measuring turnover intention and for predicting actual turnover was addressed in this study.Research design, approach and method: The study was based on a census-based sample (n= 2429 of employees in an information, communication and technology (ICT sector company (N= 23 134 where the TIS-6 was used as one of the criterion variables. The leavers (those who left the company in this sample were compared with the stayers (those who remained in the employ of the company in this sample in respect of different variables used in the study.Main findings: It was established that the TIS-6 could measure turnover intentions reliably (α= 0.80. The TIS-6 could significantly distinguish between leavers and stayers (actual turnover, thereby confirming its criterion-predictive validity. The scale also established statistically significant differences between leavers and stayers in respect of a number of the remaining theoretical variables used in the study, thereby also confirming its differential validity. These comparisons were conducted for both the 4-month and the 4-year period after the survey was conducted.Practical/managerial implications: Turnover intention is related to a number of variables in the study which necessitates a reappraisal and a reconceptualisation of existing turnover intention models.Contribution/value-add: The TIS-6 can be used as a reliable and valid scale to assess turnover intentions and can therefore be used in research to validly and reliably assess turnover intentions or to

  4. The importance of zinc on osteoporotic bones

    Energy Technology Data Exchange (ETDEWEB)

    Lima, I.; Lopes, R.T. [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE). Programa de Engenharia Nuclear]. E-mail: ricardo@lin.ufrj.br; inaya@lin.ufrj.br; Anjos, M.J. [Universidade do Estado do Rio de Janeiro (UERJ), Rio de Janeiro, RJ (Brazil). Inst. de Fisica]. E-mail: marcelin@lin.ufrj.br; Farias, M.L.F. [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil). Hospital Universitario. Servico de Endocrinologia]. E-mail: fleiuss@hucff.ufrj.br; Rosenthal, D. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Inst. de Biofisica Carlos Chagas Filho. Lab. de Fisiologia Endocrina]. E-mail: doris@biof.ufrj.br

    2007-07-01

    Zinc is an essential element that can be found in bones, such as calcium and phosphorus. It seems to have effects on growth, bone turnover and mineralization making its relationship with bones still opening. The goal of this study is, by XRF analysis, characterized bone samples, with and without pathology, in the trabecular region. For that purpose, it was used an XRF beam line at the Synchrotron Light National Laboratory (Campinas, Brazil). The results show that the profile of the zinc distribution and its concentration on femoral heads are strongly related to the associated pathology. (author)

  5. Improvements to Kramers Turnover Theory

    CERN Document Server

    Pollak, Eli

    2013-01-01

    The Kramers turnover problem, that is obtaining a uniform expression for the rate of escape of a particle over a barrier for any value of the external friction was solved in the eighties. Two formulations were given, one by Melnikov and Meshkov (MM) (J. Chem. Phys. 85, 1018 (1986)), which was based on a perturbation expansion for the motion of the particle in the presence of friction. The other, by Pollak, Grabert and Haenggi (PGH) (J. Chem. Phys. 91, 4073 (1989)), valid also for memory friction, was based on a perturbation expansion for the motion along the collective unstable normal mode of the particle. Both theories did not take into account the temperature dependence of the average energy loss to the bath. Increasing the bath temperature will reduce the average energy loss. In this paper, we analyse this effect, using a novel perturbation theory. We find that within the MM approach, the thermal energy gained from the bath diverges, the average energy gain becomes infinite, implying an essential failure o...

  6. Blueberry consumption prevents loss of collagen in bone matrix and inhibits senescence pathways in osteoblastic cells.

    Science.gov (United States)

    Zhang, Jian; Lazarenko, Oxana P; Blackburn, Michael L; Badger, Thomas M; Ronis, Martin J J; Chen, Jin-Ran

    2013-06-01

    Ovariectomy (OVX)-induced bone loss has been linked to increased bone turnover and higher bone matrix collagen degradation as the result of osteoclast activation. However, the role of degraded collagen matrix in the fate of resident bone-forming cells is unclear. In this report, we show that OVX-induced bone loss is associated with profound decreases in collagen 1 and Sirt1. This was accompanied by increases in expression and activity of the senescence marker collagenase and expression of p16/p21 in bone. Feeding a diet supplemented with blueberries (BB) to pre-pubertal rats throughout development or only prior to puberty [postnatal day 21 (PND21) to PND34] prevents OVX-induced effects on expression of these molecules at PND68. In order to provide more evidence and gain a better understanding on the association between bone collagen matrix and resident bone cell fate, in vitro studies on the cellular senescence pathway using primary calvarial cells and three cell lines (ST2 cells, OB6, and MLO-Y4) were conducted. We found that senescence was inhibited by collagen in a dose-response manner. Treatment of cells with serum from OVX rats accelerated osteoblastic cell senescence pathways, but serum from BB-fed OVX rats had no effect. In the presence of low collagen or treatment with OVX rat serum, ST2 cells exhibited higher potential to differentiate into adipocytes. Finally, we demonstrated that bone cell senescence is associated with decreased Sirt1 expression and activated p53, p16, and p21. These results suggest that (1) a significant prevention of OVX-induced bone cell senescence from adult rats can occur after only 14 days consumption of a BB-containing diet immediately prior to puberty, and (2) the molecular mechanisms underlying this effect involves, at least in part, prevention of collagen degradation. PMID:22555620

  7. Bone cysts: unicameral and aneurysmal bone cyst.

    Science.gov (United States)

    Mascard, E; Gomez-Brouchet, A; Lambot, K

    2015-02-01

    Simple and aneurysmal bone cysts are benign lytic bone lesions, usually encountered in children and adolescents. Simple bone cyst is a cystic, fluid-filled lesion, which may be unicameral (UBC) or partially separated. UBC can involve all bones, but usually the long bone metaphysis and otherwise primarily the proximal humerus and proximal femur. The classic aneurysmal bone cyst (ABC) is an expansive and hemorrhagic tumor, usually showing characteristic translocation. About 30% of ABCs are secondary, without translocation; they occur in reaction to another, usually benign, bone lesion. ABCs are metaphyseal, excentric, bulging, fluid-filled and multicameral, and may develop in all bones of the skeleton. On MRI, the fluid level is evocative. It is mandatory to distinguish ABC from UBC, as prognosis and treatment are different. UBCs resolve spontaneously between adolescence and adulthood; the main concern is the risk of pathologic fracture. Treatment in non-threatening forms consists in intracystic injection of methylprednisolone. When there is a risk of fracture, especially of the femoral neck, surgery with curettage, filling with bone substitute or graft and osteosynthesis may be required. ABCs are potentially more aggressive, with a risk of bone destruction. Diagnosis must systematically be confirmed by biopsy, identifying soft-tissue parts, as telangiectatic sarcoma can mimic ABC. Intra-lesional sclerotherapy with alcohol is an effective treatment. In spinal ABC and in aggressive lesions with a risk of fracture, surgical treatment should be preferred, possibly after preoperative embolization. The risk of malignant transformation is very low, except in case of radiation therapy.

  8. Bone Grafts

    Science.gov (United States)

    ... repair and rebuild diseased bones in your hips, knees, spine, and sometimes other bones and joints. Grafts can also repair bone loss caused by some types of fractures or cancers. Once your body accepts the bone ...

  9. Evaluation of bone targeting salmon calcitonin analogues in rats developing osteoporosis and adjuvant arthritis.

    Science.gov (United States)

    Bhandari, Krishna H; Asghar, Waheed; Newa, Madhuri; Jamali, Fakhreddin; Doschak, Michael R

    2015-01-01

    Synthetic analogues of the peptide hormone calcitonin have been used in medicine as biologic drug therapies for decades, to treat pathological conditions of excessive bone turnover, such as osteoporosis, where more bones are removed than replaced during bone remodeling. Osteoporosis and other chronic skeletal diseases, including inflammatory arthritis, exact a substantial and growing toll on aging populations worldwide however they respond poor to synthetic biologic drug therapy, due in part to the rapid half-life of elimination, which for calcitonin is 43 minutes. To address those shortcomings, we have developed and synthesized bone-targeting variants of calcitonin as a targeted drug delivery strategy, by conjugation to bisphosphonate drug bone-seeking functional groups in highly specific reaction conditions. To evaluate their in vivo efficacy, bisphosphonate-mediated bone targeting with PEGylated (polyethylene glycol conjugated) and non-PEGylated salmon calcitonin analogues were synthesized and dose escalation was performed in female rats developing Osteoporosis. The bone-targeting calcitonin analogues were also tested in a separate cohort of male rats developing adjuvant-induced arthritis. Ovariectomized female rats developing Osteoporosis were administered daily sub-cutaneous injection of analogues equivalent to 5, 10 and 20 IU/kg of calcitonin for 3 months. Adjuvant arthritis was developed in male rats by administering Mycobacterium butyricum through tail base injection. Daily sub-cutaneous injection of analogues equivalent to 20 IU/kg of calcitonin was administered and the rats were measured for visible signs of inflammation to a 21 day endpoint. In both studies, the effect of drug intervention upon bone volume and bone mineral density (BMD) was assessed by measuring the trabecular bone volume percentage and BMD at the proximal tibial metaphysis using in vivo micro-computed tomography. With dose escalation studies, only bone targeting analogue dosed groups

  10. Biomimetic catalysis: Taking on the turnover challenge

    Science.gov (United States)

    Hooley, Richard J.

    2016-03-01

    Emulating the efficiency with which enzymes catalyse reactions has often been used as inspiration to develop self-assembled cages. Now two studies present approaches to achieving catalyst turnover -- one of the biggest challenges in achieving truly biomimetic catalysis.

  11. THEORETICAL ASPECTS REGARDING THE TURNOVER ANALYSIS

    Directory of Open Access Journals (Sweden)

    CARUNTU ROXANA CORINA

    2011-09-01

    Full Text Available Nowadays, when the economic crisis seems not to be overcome by the authorities it is important for companies to see how they are performing, if their products are sold or not and if it is necessary to take measures according to the results obtained. The turnover expresses the total revenues obtained by a company from its current commercial activities, being one of the most important indicators of measuring the performance of the company. The aim of this paper is to stress the theoretical implications that turnover has over the economic activity of a company. In the chapters of the paper we will present theoretical notions regarding the concept of turnover analysis, meaning analysis of the turnover’s dynamics, the structural analysis of turnover.

  12. Two integral membrane proteins located in the cis-middle and trans-part of the Golgi system acquire sialylated N-linked carbohydrates and display different turnovers and sensitivity to cAMP-dependent phosphorylation.

    Science.gov (United States)

    Yuan, L; Barriocanal, J G; Bonifacino, J S; Sandoval, I V

    1987-07-01

    The localization and chemical characteristics of two Golgi integral membrane proteins (GIMPs) have been studied using monoclonal antibodies. The two proteins are segregated in different parts of the Golgi system and whereas GIMPc(130 kD) is located in the cis and medial cisternae, GIMPt (100 kD) is confined in the trans-most cisterna and trans-tubular network. Both GIMPs are glycoproteins that contain N- and O-linked carbohydrates. The N-linked carbohydrates were exclusively of the complex type. Although excluded from the trans-side of the Golgi system, where sialylation is believed to occur, GIMPc acquires sialic acid in both its N- and O-linked carbohydrates. Sialic acid was also detected in the N-linked carbohydrates of GIMPt. GIMPc is apparently phosphorylated in the luminal domain in vivo. Phosphorylation occurred exclusively on serine and was stimulated by dibutyryl cyclic AMP. GIMPc and GIMPt displayed half-lives of 20 and 9 h, respectively. PMID:3301866

  13. Biglycan deficiency interferes with ovariectomy-induced bone loss

    DEFF Research Database (Denmark)

    Nielsen, Karina L; Allen, Matthew R; Bloomfield, Susan A;

    2003-01-01

    Biglycan is a matrix proteoglycan with a possible role in bone turnover. In a 4-week study with sham-operated or OVX biglycan-deficient or wildtype mice, we show that biglycan-deficient mice are resistant to OVX-induced trabecular bone loss and that there is a gender difference in the response to...

  14. Bone within a bone

    Energy Technology Data Exchange (ETDEWEB)

    Williams, H.J.; Davies, A.M. E-mail: wendy.turner@roh.nhs.uk; Chapman, S

    2004-02-01

    The 'bone within a bone' appearance is a well-recognized radiological term with a variety of causes. It is important to recognize this appearance and also to be aware of the differential diagnosis. A number of common conditions infrequently cause this appearance. Other causes are rare and some remain primarily of historical interest, as they are no longer encountered in clinical practice. In this review we illustrate some of the conditions that can give the bone within a bone appearance and discuss the physiological and pathological aetiology of each where known.

  15. Thrombospondin-1 regulates bone homeostasis through effects on bone matrix integrity and nitric oxide signaling in osteoclasts

    OpenAIRE

    Sarah R Amend; Uluckan, Ozge; Hurchla, Michelle; Leib, Daniel; Novack, Deborah Veis; Silva, Matthew; Frazier, William; Weilbaecher, Katherine N.

    2015-01-01

    Thrombospondin-1 (TSP1), an endogenous antiangiogenic, is a widely expressed secreted ligand with roles in migration, adhesion and proliferation and is a target for new therapeutics. While TSP1 is present in the bone matrix and several TSP1 receptors play roles in bone biology, the role of TSP1 in bone remodeling has not been fully elucidated. Bone turnover is characterized by coordinated activity of bone-forming osteoblasts (OB) and bone-resorbing osteoclasts (OC). TSP1−/− mice had increased...

  16. Association of pioglitazone treatment with decreased bone mineral density in obese premenopausal patients with polycystic ovary syndrome: a randomized, placebo-controlled trial

    DEFF Research Database (Denmark)

    Glintborg, D.; Andersen, Mikael; Hagen, C.;

    2008-01-01

    OBJECTIVE: Our objective was to investigate the effect of pioglitazone on bone mineral density (BMD) and bone turnover markers in polycystic ovary syndrome (PCOS). DESIGN AND SETTING: We conducted a randomized, placebo-controlled study at an outpatient clinic at a university hospital. PATIENTS......, sex hormones, and body composition. CONCLUSION: Pioglitazone treatment was followed by decreased lumbar and hip BMD and decreased measures of bone turnover in a premenopausal study population relatively protected from bone mineral loss Udgivelsesdato: 2008/5...

  17. Impact of motivation principles on employee turnover

    OpenAIRE

    VNOUČKOVÁ, Lucie; Klupáková, Hana

    2013-01-01

    The article focuses on the analysis of motivation principles in human resource management and their further verification by factor analysis. The objective is to identify the main motivation principles and their impacts on employee turnover as well as formulate suggested practices to eliminate the negative impact of employee disaffection and turnover. The identification of motivation principles is based on a content analysis of professional and scientific publications aimed at moti...

  18. Labor Turnover and Labor Legislation in Brazil

    OpenAIRE

    Gustavo Gonzaga

    2003-01-01

    One of the main characteristics of the Brazilian labor market is its impressively high job and worker turnover rates. Although labor legislation in Brazil is very restrictive, dismissal costs are not high when compared with other Latin American countries. Moreover, many authors argue that the design of some job security programs creates perverse incentives that generate labor turnover. The objective of this paper is twofold. First, we describe Brazilian labor legislation, with emphasis on job...

  19. Effect of long-term growth hormone treatment on bone mass and bone metabolism in growth hormone-deficient men

    NARCIS (Netherlands)

    Bravenboer, N; Holzmann, PJ; ter Maaten, JC; Stuurman, LM; Roos, JC; Lips, P

    2005-01-01

    Long-term GH treatment in GH-deficient men resulted in a continuous increase in bone turnover as shown by histomorphometry. BMD continuously increased in all regions of interest, but more in the regions with predominantly cortical bone. Introduction: Adults with growth hormone (GH) deficiency have r

  20. Failure to Generate Bone Marrow Adipocytes Does Not Protect Mice from Ovariectomy-Induced Osteopenia

    OpenAIRE

    Iwaniec, Urszula T; Turner, Russell T.

    2012-01-01

    A reciprocal association between bone marrow fat and bone mass has been reported in ovariectomized rodents, suggesting that bone marrow adipogenesis has a negative effect on bone growth and turnover balance. Mice with loss of function mutations in kit receptor (kitW/W-v) have no bone marrow adipocytes in tibia or lumbar vertebra. We therefore tested the hypothesis that marrow fat contributes to development of osteopenia by comparing the skeletal response to ovariectomy (ovx) in growing wild t...

  1. The Effects of Employee Turnover on Those Who Stay.

    Science.gov (United States)

    Sheehan, Eugene P.; Hockett, Cherri

    Research on employee turnover which has examined why employees quit their jobs has identified a wide range of variables that are associated with turnover, but has provided little information about the consequences of turnover for those who remain in an organization. This study was conducted to examine whether the manner in which turnover is…

  2. Inulin, oligofructose and bone health: experimental approaches and mechanisms.

    Science.gov (United States)

    Weaver, Connie M

    2005-04-01

    Inulin-type fructans have been proposed to benefit mineral retention, thereby enhancing bone health. Many, but not all, experimental animal studies have shown increased mineral absorption by feeding non-digestible oligosaccharides. Possible reasons for inconsistencies are explored. A few studies have reported an enhanced bone mineral density or content. Bone health can be evaluated in chronic feeding studies with bone densitometry, bone breaking strength, bone mineral concentration and bone structure. Isotopic Ca tracers can be used to determine the point of metabolism affected by feeding a functional food ingredient. These methods and the effects of feeding inulin-type fructose are reviewed. Inulin-type fructans enhance Mg retention. Chicory long-chain inulin and oligofructose enhance femoral Ca content, bone mineral density and Ca retention through enhanced Ca absorption and suppressed bone turnover rates, but it is not bone-promoting under all conditions.

  3. Phytonutrients for bone health during ageing.

    Science.gov (United States)

    Sacco, Sandra Maria; Horcajada, Marie-Noëlle; Offord, Elizabeth

    2013-03-01

    Osteoporosis is a skeletal disease characterized by a decrease in bone mass and bone quality that predispose an individual to an increased risk of fragility fractures. Evidence demonstrating a positive link between certain dietary patterns (e.g. Mediterranean diet or high consumption of fruits and vegetables) and bone health highlights an opportunity to investigate their potential to protect against the deterioration of bone tissue during ageing. While the list of these phytonutrients is extensive, this review summarizes evidence on some which are commonly consumed and have gained increasing attention over recent years, including lycopene and various polyphenols (e.g. polyphenols from tea, grape seed, citrus fruit, olive and dried plum). Evidence to define a clear link between these phytonutrients and bone health is currently insufficient to generate precise dietary recommendations, owing to mixed findings or a scarcity in clinical data. Moreover, their consumption typically occurs within the context of a diet consisting of a mix of phytonutrients and other nutrients rather than in isolation. Future clinical trials that can apply a robust set of outcome measurements, including the determinants of bone strength, such as bone quantity (i.e. bone mineral density) and bone quality (i.e. bone turnover and bone microarchitecture), will help to provide a more comprehensive outlook on how bone responds to these various phytonutrients. Moreover, future trials that combine these phytonutrients with established bone nutrients (i.e. calcium and vitamin D) are needed to determine whether combined strategies can produce more robust effects on skeletal health.

  4. DETERMINANTS OF TURNOVER INTENTIONS AMONG CHINESE OFF FARM MIGRANTS

    OpenAIRE

    Russell Smyth; Qingguo Zhai; Xiaoxu Li

    2008-01-01

    This study examines the determinants of turnover intentions of off farm migrant workers, using data collected from China's Jiangsu Province. Turnover intention is posited to be a function of demographic/human capital characteristics, job characteristics and job satisfaction. We find that higher levels of education have a positive effect on reported turnover intentions, while higher income and job satisfaction have a negative effect on turnover intentions. As turnover intentions represent a go...

  5. Distinct Characteristics of Mandibular Bone Collagen Relative to Long Bone Collagen: Relevance to Clinical Dentistry

    Directory of Open Access Journals (Sweden)

    Takashi Matsuura

    2014-01-01

    Full Text Available Bone undergoes constant remodeling throughout life. The cellular and biochemical mechanisms of bone remodeling vary in a region-specific manner. There are a number of notable differences between the mandible and long bones, including developmental origin, osteogenic potential of mesenchymal stem cells, and the rate of bone turnover. Collagen, the most abundant matrix protein in bone, is responsible for determining the relative strength of particular bones. Posttranslational modifications of collagen, such as intermolecular crosslinking and lysine hydroxylation, are the most essential determinants of bone strength, although the amount of collagen is also important. In comparison to long bones, the mandible has greater collagen content, a lower amount of mature crosslinks, and a lower extent of lysine hydroxylation. The great abundance of immature crosslinks in mandibular collagen suggests that there is a lower rate of cross-link maturation. This means that mandibular collagen is relatively immature and thus more readily undergoes degradation and turnover. The greater rate of remodeling in mandibular collagen likely renders more flexibility to the bone and leaves it more suited to constant exercise. As reviewed here, it is important in clinical dentistry to understand the distinctive features of the bones of the jaw.

  6. Stayers, Leavers, and Switchers among Certified Nursing Assistants in Nursing Homes: A Longitudinal Investigation of Turnover Intent, Staff Retention, and Turnover

    Science.gov (United States)

    Rosen, Jules; Stiehl, Emily M.; Mittal, Vikas; Leana, Carrie R.

    2011-01-01

    Purpose: Studies of certified nursing assistant (CNA) turnover in nursing homes are typically cross-sectional and include full-time and part-time workers. We conducted a longitudinal study to evaluate the job factors and work attitudes associated with just full-time staying or leaving. For those who did not stay, we assessed reasons for leaving…

  7. Does increased local bone resorption secondary to breast and prostate cancer result in increased cartilage degradation?

    DEFF Research Database (Denmark)

    Leeming, Diana J; Byrjalsen, Inger; Qvist, Per;

    2008-01-01

    BACKGROUND: Breast and prostate cancer patients often develop lesions of locally high bone turnover, when the primary tumor metastasizes to the bone causing an abnormal high bone resorption at this site. The objective of the present study was to determine whether local increased bone turnover...... in breast and prostate cancer patients is associated with an increase in cartilage degradation and to test in vitro whether osteoclasts or cathepsin K alone generate CTXII from human bone. METHODS: The study included 132 breast and prostate cancer patient, where presence of bone metastases was graded...... according to the Soloway score. Total bone resorption (CTXItotal) and cartilage degradation (CTXII) were determined. RESULTS: Breast and prostate cancer patients with bone metastases revealed significant increased levels of CTXItotal at Soloway scores 1 and higher compared to patients without bone...

  8. Changes in biochemical bone markers during pregnancy and puerperium.

    OpenAIRE

    Yoon, B. K.; Lee, J.W.; Choi, D. S.; Roh, C. R.; Lee, J.H.

    2000-01-01

    To elucidate the changes in bone turnover during pregnancy and puerperium, we measured serially the levels of serum osteocalcin and urine deoxypyridinoline (Dpy) as markers of bone formation and bone resorption, respectively, in 22 healthy women with normal pregnancy. Nineteen non-pregnant women served as control. The Dpy levels increased significantly at 16 weeks of pregnancy and remained elevated thereafter. The levels of osteocalcin, however, were significantly decreased at 16 weeks of pre...

  9. On gigahertz spectral turnovers in pulsars

    CERN Document Server

    Rajwade, Kaustubh; Anderson, Loren D

    2015-01-01

    Pulsars are known to emit non-thermal radio emission that is generally a power-law function of frequency. In some cases, a turnover is seen at frequencies around 100~MHz. Kijak et al. have reported the presence of a new class of ''Gigahertz Peaked Spectrum'' (GPS) pulsars that show spectral turnovers at frequencies around 1 GHz. We apply a model based on free-free thermal absorption to explain these turnovers in terms of surrounding material such as the dense environments found in HII regions, Pulsar Wind Nebulae (PWNe), or in cold, partially ionized molecular clouds. We show that the turnover frequency depends on the electron temperature of the environment close to the pulsar, as well as the emission measure along the line of sight. We fitted this model to the radio fluxes of known GPS pulsars and show that it can replicate the GHz turnover. From the thermal absorption model, we demonstrate that normal pulsars would exhibit a GPS-like behaviour if they were in a dense environment. We discuss the application ...

  10. Rhus javanica Gall Extract Inhibits the Differentiation of Bone Marrow-Derived Osteoclasts and Ovariectomy-Induced Bone Loss

    Directory of Open Access Journals (Sweden)

    Tae-Ho Kim

    2016-01-01

    Full Text Available Inhibition of osteoclast differentiation and bone resorption is a therapeutic strategy for the management of postmenopausal bone loss. This study investigated the effects of Rhus javanica (R. javanica extracts on bone marrow cultures to develop agents from natural sources that may prevent osteoclastogenesis. Extracts of R. javanica (eGr cocoons spun by Rhus javanica (Bell. Baker inhibited the osteoclast differentiation and bone resorption. The effects of aqueous extract (aeGr or 100% ethanolic extract (eeGr on ovariectomy- (OVX- induced bone loss were investigated by various biochemical assays. Furthermore, microcomputed tomography (µCT was performed to study bone remodeling. Oral administration of eGr (30 mg or 100 mg/kg/day for 6 weeks augmented the inhibition of femoral bone mineral density (BMD, bone mineral content (BMC, and other factors involved in bone remodeling when compared to OVX controls. Additionally, eGr slightly decreased bone turnover markers that were increased by OVX. Therefore, it may be suggested that the protective effects of eGr could have originated from the suppression of OVX-induced increase in bone turnover. Collectively, the findings of this study indicate that eGr has potential to activate bone remodeling by inhibiting osteoclast differentiation and bone loss.

  11. Progesterone and Bone: Actions Promoting Bone Health in Women

    Directory of Open Access Journals (Sweden)

    Vanadin Seifert-Klauss

    2010-01-01

    Full Text Available Estradiol (E2 and progesterone (P4 collaborate within bone remodelling on resorption (E2 and formation (P4. We integrate evidence that P4 may prevent and, with antiresorptives, treat women's osteoporosis. P4 stimulates osteoblast differentiation in vitro. Menarche (E2 and onset of ovulation (P4 both contribute to peak BMD. Meta-analysis of 5 studies confirms that regularly cycling premenopausal women lose bone mineral density (BMD related to subclinical ovulatory disturbances (SODs. Cyclic progestin prevents bone loss in healthy premenopausal women with amenorrhea or SOD. BMD loss is more rapid in perimenopause than postmenopause—decreased bone formation due to P4 deficiency contributes. In 4 placebo-controlled RCTs, BMD loss is not prevented by P4 in postmenopausal women with increased bone turnover. However, 5 studies of E2-MPA co-therapy show greater BMD increases versus E2 alone. P4 fracture data are lacking. P4 prevents bone loss in pre- and possibly perimenopausal women; progesterone co-therapy with antiresorptives may increase bone formation and BMD.

  12. Quantification of isotopic turnover in agricultural systems

    Science.gov (United States)

    Braun, A.; Auerswald, K.; Schnyder, H.

    2012-04-01

    The isotopic turnover, which is a proxy for the metabolic rate, is gaining scientific importance. It is quantified for an increasing range of organisms, from microorganisms over plants to animals including agricultural livestock. Additionally, the isotopic turnover is analyzed on different scales, from organs to organisms to ecosystems and even to the biosphere. In particular, the quantification of the isotopic turnover of specific tissues within the same organism, e.g. organs like liver and muscle and products like milk and faeces, has brought new insights to improve understanding of nutrient cycles and fluxes, respectively. Thus, the knowledge of isotopic turnover is important in many areas, including physiology, e.g. milk synthesis, ecology, e.g. soil retention time of water, and medical science, e.g. cancer diagnosis. So far, the isotopic turnover is quantified by applying time, cost and expertise intensive tracer experiments. Usually, this comprises two isotopic equilibration periods. A first equilibration period with a constant isotopic input signal is followed by a second equilibration period with a distinct constant isotopic input signal. This yields a smooth signal change from the first to the second signal in the object under consideration. This approach reveals at least three major problems. (i) The input signals must be controlled isotopically, which is almost impossible in many realistic cases like free ranging animals. (ii) Both equilibration periods may be very long, especially when the turnover rate of the object under consideration is very slow, which aggravates the first problem. (iii) The detection of small or slow pools is improved by large isotopic signal changes, but large isotopic changes also involve a considerable change in the input material; e.g. animal studies are usually carried out as diet-switch experiments, where the diet is switched between C3 and C4 plants, since C3 and C4 plants differ strongly in their isotopic signal. The

  13. New simulation model for bone formation markers in osteoporosis patients treated with once-weekly teriparatide

    Institute of Scientific and Technical Information of China (English)

    Sakae Tanaka; Taiji Adachi; Tatsuhiko Kuroda; Toshitaka Nakamura; Masataka Shiraki; Toshitsugu Sugimoto; Yasuhiro Takeuchi; Mitsuru Saito; John P Bilezikian

    2014-01-01

    Daily 20-mg and once-weekly 56.5-mg teriparatide (parathyroid hormone 1–34) treatment regimens increase bone mineral density (BMD) and prevent fractures, but changes in bone turnover markers differ between the two regimens. The aim of the present study was to explain changes in bone turnover markers using once-weekly teriparatide with a simulation model. Temporary increases in bone formation markers and subsequent decreases were observed during once-weekly teriparatide treatment for 72 weeks. These observations support the hypothesis that repeated weekly teriparatide administration stimulates bone remodeling, replacing old bone with new bone and leading to a reduction in the active remodeling surface. A simulation model was developed based on the iterative remodeling cycle that occurs on residual old bone. An increase in bone formation and a subsequent decrease were observed in the preliminary simulation. For each fitted time point, the predicted value was compared to the absolute values of the bone formation and resorption markers and lumbar BMD. The simulation model strongly matched actual changes in bone turnover markers and BMD. This simulation model indicates increased bone formation marker levels in the early stage and a subsequent decrease. It is therefore concluded that remodeling-based bone formation persisted during the entire treatment period with once-weekly teriparatide.

  14. Turnover of Public School Superintendents in Arizona

    Science.gov (United States)

    Meyer, Joyce Ntsoaki

    2013-01-01

    This study used a descriptive qualitative design utilizing a phenomenological approach to determine and examine the reasons behind the voluntary or involuntary turnover of Arizona school superintendents. Open-ended questions were used to interview five superintendents who had left their districts between 2008 and 2013 about their perceptions on…

  15. Teacher Turnover in Charter Schools. Research Brief

    Science.gov (United States)

    Stuit, David; Smith, Thomas M.

    2010-01-01

    The current study aimed to contribute to a deeper understanding of the organizational conditions of charter schools by examining teacher turnover. Using data from the National Center for Education Statistics (NCES) 2003-04 Schools and Staffing Survey (SASS) and the Teacher Follow-Up Survey (TFS), researchers from the National Center on School…

  16. Director Turnover: An Australian Academic Development Study

    Science.gov (United States)

    Fraser, Kym; Ryan, Yoni

    2012-01-01

    Although it can be argued that directors of central academic development units (ADUs) are critical to the implementation of university teaching and learning strategies, it would appear there is a high director turnover rate. While research in the USA, the UK, and Australia illustrates that ADUs are frequently closed or restructured, that research…

  17. A Turnover Model for the Mexican Maquiladoras.

    Science.gov (United States)

    Maertz, Carl P.; Stevens, Michael J.; Campion, Michael A.

    2003-01-01

    From interviews with 47 Mexican maquiladora workers, a model of voluntary turnover was created and compared with models from the United States, Canada, England, and Australia. Despite similarities, the cultural and economic environment affected the precise content of antecedents in the Mexican model. (Contains 63 references.) (SK)

  18. Labour Turnover in the Hospitality Industry

    Directory of Open Access Journals (Sweden)

    Ersan Suria Pranoto

    2011-04-01

    much increases when employees are far more specialised, more difficult to find and requires more training. Therefore, it is in the best interests of hospitality managers to understand the causes and the effects of turnover so that they may reduce its costs.

  19. Antecedents of Norwegian Beginning Teachers' Turnover Intentions

    Science.gov (United States)

    Tiplic, Dijana; Brandmo, Christian; Elstad, Eyvind

    2015-01-01

    This study aims at exploring several individual, organizational, and contextual factors that may affect beginning teachers' turnover intentions during their first years of practice. The sample consists of 227 beginning teachers (69% female and 31% male) from 133 schools in Norway. The results show four important antecedents of beginning teachers'…

  20. Employee Development and Turnover Intention: Theory Validation

    Science.gov (United States)

    Rahman, Wali; Nas, Zekeriya

    2013-01-01

    Purpose: This study aims to examine the pattern of behavior of turnover intentions in developing countries "vis-a-vis" the one in advanced countries through the empirical data from public universities in Khyber Pakhtunkhwa, Pakistan. The study provides empirical evidence from academia in Pakistan, thereby enriching the understanding of…

  1. Bone cysts: unicameral and aneurysmal bone cyst.

    Science.gov (United States)

    Mascard, E; Gomez-Brouchet, A; Lambot, K

    2015-02-01

    Simple and aneurysmal bone cysts are benign lytic bone lesions, usually encountered in children and adolescents. Simple bone cyst is a cystic, fluid-filled lesion, which may be unicameral (UBC) or partially separated. UBC can involve all bones, but usually the long bone metaphysis and otherwise primarily the proximal humerus and proximal femur. The classic aneurysmal bone cyst (ABC) is an expansive and hemorrhagic tumor, usually showing characteristic translocation. About 30% of ABCs are secondary, without translocation; they occur in reaction to another, usually benign, bone lesion. ABCs are metaphyseal, excentric, bulging, fluid-filled and multicameral, and may develop in all bones of the skeleton. On MRI, the fluid level is evocative. It is mandatory to distinguish ABC from UBC, as prognosis and treatment are different. UBCs resolve spontaneously between adolescence and adulthood; the main concern is the risk of pathologic fracture. Treatment in non-threatening forms consists in intracystic injection of methylprednisolone. When there is a risk of fracture, especially of the femoral neck, surgery with curettage, filling with bone substitute or graft and osteosynthesis may be required. ABCs are potentially more aggressive, with a risk of bone destruction. Diagnosis must systematically be confirmed by biopsy, identifying soft-tissue parts, as telangiectatic sarcoma can mimic ABC. Intra-lesional sclerotherapy with alcohol is an effective treatment. In spinal ABC and in aggressive lesions with a risk of fracture, surgical treatment should be preferred, possibly after preoperative embolization. The risk of malignant transformation is very low, except in case of radiation therapy. PMID:25579825

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

    Science.gov (United States)

    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 (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

  3. Work-Related Variables and Turnover Intention among Registered Nurses.

    Science.gov (United States)

    Pooyan, Abdullah; And Others

    1990-01-01

    Health institutions have become more interested in the causes of job turnover among registered nurses. Proper management of job turnover can improve the financial health and long-term survival of health care institutions. (Author)

  4. Predictors of Staff Turnover and Turnover Intentions within Addiction Treatment Settings: Change Over Time Matters

    OpenAIRE

    Garner, Bryan R.; Hunter, Brooke D.

    2014-01-01

    This study examined the extent to which changes over time in clinicians’ responses to measures of work attitude (eg, job satisfaction) and psychological climate (eg, supervisor support) could predict actual turnover and turnover intentions above and beyond absolute levels of these respective measures. Longitudinal data for this study were collected from a sample of clinicians (N = 96) being trained to implement an evidence-based treatment for adolescent substance use disorders. Supporting fin...

  5. ROOT GROWTH AND TURNOVER IN DIFFERENT AGED PONDEROSA PINE STANDS IN OREGON, USA

    Science.gov (United States)

    The impacts of pollution and climate change on soil carbon dynamics are poorly understood, in part due to a lack of information regarding root production and turnover in natural ecosystems. In order to examine how root dynamics change with stand age in ponderosa pine forests (...

  6. Structures of two exonucleases involved in controlled RNA turnover in yeast

    DEFF Research Database (Denmark)

    Jonstrup, Anette Thyssen; Midtgaard, Søren Fuglsang; Van, Lan Bich;

    2p is a catalytic subunit of the cytoplasmic deadenylase complex [2], which removes the poly(A) tail in the 3'-end of mRNA, the first and rate-limiting step of controlled mRNA turnover in the general eukaryotic mRNA degradation pathway [3]. The crystal structure of the central part of S. cerevisiae...

  7. Kinetic Analysis of 18F-Fluoride PET Images of Breast Cancer Bone Metastases

    OpenAIRE

    Doot, Robert K; Muzi, Mark; Peterson, Lanell M.; Schubert, Erin K; Gralow, Julie R.; Specht, Jennifer M.; Mankoff, David A.

    2010-01-01

    The most common site of metastasis for breast cancer is bone. Quantitative 18F-fluoride PET can estimate the kinetics of fluoride incorporation into bone as a measure of fluoride transport, bone formation, and turnover. The purpose of this analysis was to evaluate the accuracy and precision of 18F-fluoride model parameter estimates for characterizing regional kinetics in metastases and normal bone in breast cancer patients.

  8. Employee Turnover Intentions: Job Stress or Perceived Alternative External Opportunities

    OpenAIRE

    Dr Riyaz Ahmad Rainayee

    2013-01-01

    Turnover intention has been a critical issue for management for many years (Chen, Lin & Lien, 2010) and it is a major problem for organisations till now. Therefore, much attention has been paid over the past some years towards employees’ turnover behaviour and the major causes that lead towards the turnover intention of employees (Richer, Blanchard & Vallerandi, 2002).The broad range of turnover studies is indicative of the significance and complexity of the issue. The phenomenon attracts int...

  9. Regulatory mechanisms of skeletal muscle protein turnover during exercise

    DEFF Research Database (Denmark)

    Rose, Adam John; Richter, Erik

    2009-01-01

    Skeletal muscle protein turnover is a relatively slow metabolic process that is altered by various physiological stimuli such as feeding/fasting and exercise. During exercise, catabolism of amino acids contributes very little to ATP turnover in working muscle. With regards to protein turnover...... with available and new techniques will undoubtedly reveal the functional significance and signaling mechanisms behind changes in skeletal muscle protein turnover during exercise. Key words: Exercise, skeletal muscle, protein metabolism, translation....

  10. Investing in Leadership: The District's Role in Managing Principal Turnover

    Science.gov (United States)

    Mascall, Blair; Leithwood, Kenneth

    2010-01-01

    This article presents the results of research into the impact of principal turnover on schools, and the ability of schools to mitigate the negative effects of frequent turnover by distributing leadership in the schools. The findings from this qualitative and quantitative analysis show that rapid principal turnover does indeed have a negative…

  11. High School Band Students' Perspectives of Teacher Turnover

    Science.gov (United States)

    Kloss, Thomas E.

    2013-01-01

    Teacher turnover remains an important issue in education. The least researched perspectives, though, are those of the students who experience teacher turnover. The purpose of this study was to examine how high school band students experience teacher turnover. A total of twelve students were interviewed, representing three schools that experienced…

  12. Salary and Ranking and Teacher Turnover: A Statewide Study

    Science.gov (United States)

    Garcia, Cynthia Martinez; Slate, John R.; Delgado, Carmen Tejeda

    2009-01-01

    This study examined three years of data obtained from the Academic Excellence Indicator System of the State of Texas regarding teacher turnover rate and teacher salary. Across all public school districts, teacher salary was consistently negatively related to teacher turnover; that is, where salary was lower, turnover rate was higher When data were…

  13. Superintendent Turnover in Kentucky. Issues & Answers. REL 2011-No. 113

    Science.gov (United States)

    Johnson, Jerry; Huffman, Tyler; Madden, Karen; Shope, Shane

    2011-01-01

    This study examines superintendent turnover in Kentucky public school districts for 1998/99-2007/08, looking at how turnover varies by rural status, Appalachian and non-Appalachian region, and 2007/08 school district characteristics. Key findings include: (1) Kentucky school districts averaged one superintendent turnover during 1998/99-2007/08;…

  14. 41 CFR 109-27.5002 - Stores inventory turnover ratio.

    Science.gov (United States)

    2010-07-01

    ... turnover ratio. 109-27.5002 Section 109-27.5002 Public Contracts and Property Management Federal Property....5002 Stores inventory turnover ratio. Comparison of investment in stores inventories to annual issues... comparison may be expressed either as a turnover ratio (dollar value of issues divided by dollar value...

  15. Turn-over in pulsar spectra above 1 GHz

    OpenAIRE

    Kijak, J.; Gupta, Y; Krzeszowski, K.

    2007-01-01

    We present the first direct evidence for turn-over in pulsar radio spectra at high frequencies. Two pulsars are now shown to have a turn-over frequency > 1GHz. We also find some evidence that the peak frequency of turn-over in pulsar spectra appears to depend on dispersion measure and pulsar age.

  16. The research methods and model of protein turnover in animal

    International Nuclear Information System (INIS)

    The author discussed the concept and research methods of protein turnover in animal body. The existing problems and the research results of animal protein turnover in recent years were presented. Meanwhile, the measures to improve the models of animal protein turnover were analyzed

  17. Job Turnover and Job Satisfaction among Nursing Home Aides.

    Science.gov (United States)

    Waxman, Howard M.; And Others

    1984-01-01

    Interviewed 234 aides in seven nursing homes concerning job turnover rate, job satisfaction, and perception of milieu. A positive association found between turnover rate and aides' perceptions of the homes' order, organization, and control suggested that job turnover would lessen with more involvement in the decision-making process. (JAC)

  18. Turnover of galactans and other cell wall polysaccharides during development of flax plants

    International Nuclear Information System (INIS)

    We investigated the synthesis and turnover of cell wall polysaccharides of the flax (Linum usitatissimum L.) plant during development of the phloem fibers. One-month-old flax plants were exposed to a 40-min pulse with 14CO2 followed by 8-h, 24-h, and 1-month periods of chase with ambient CO2, and radioactivity in cell wall sugars was determined in various plant parts. The relative radioactivity of glucose in noncellulosic polysaccharides was the highest compared with all other cell wall sugars immediately after the pulse and decreased substantially during the subsequent chase. The relative radioactivities of the other cell wall sugars changed with differing rates, indicating turnover of specific polysaccharides. Notably, after 1 month of chase there was a marked decrease in the proportional mass and total radioactivity in cell wall galactose, indicating a long-term turnover of the galactans enriched in the fiber-containing tissues. The ratio of radiolabeled xylose to arabinose also increased during the chase, indicating a turnover of arabinose-containing polymers and interconversion to xylose. The pattern of label redistribution differed between organs, indicating that the cell wall turnover processes are tissue- and cell-specific

  19. Bone Densitometry (Bone Density Scan)

    Science.gov (United States)

    ... of DXA Bone Densitometry? What is a Bone Density Scan (DXA)? Bone density scanning, also called dual-energy x-ray absorptiometry ( ... is today's established standard for measuring bone mineral density (BMD). An x-ray (radiograph) is a noninvasive ...

  20. Organizational-level study of the impact of past turnover on future turnover in the Sultanate of Oman

    Directory of Open Access Journals (Sweden)

    Ruqaiya Mohamed Al Balushi

    2013-10-01

    Full Text Available Turnover phenomena attracted researchers from all over the world for generations. Most of this research was directed towards turnover antecedents with a few scattered conceptual and empirical studies related to turnover consequences. The purpose of this study is to investigate the impact of past turnover on future turnover in public organizations, in addition to test the mediation role of organizational climate in this relationship. Public schools as separate identities were the best choice as the study sample. Data were collected through questionnaires from 142 public schools in all educational regions in Oman. Two-step structural equation modeling approach, and nested model comparison were used for data analysis. The results revealed that: (1 past turnover predicts future turnover, significantly; (2 organizational climate fails to mediate this relationship. The study added to the body of knowledge by confirming Staw’s hypothesis relating past turnover to future turnover in the Omani context. Human resource professionals and educational administration practitioners may play an important role in decreasing future turnover by tackling and decreasing past turnover, in addition to improving the relationship climate in schools. The study is limited to public schools in Oman and further studies about turnover consequences in the Arabic context are needed to affirm the results.

  1. Optimizing Bone Health in Duchenne Muscular Dystrophy

    Directory of Open Access Journals (Sweden)

    Jason L. Buckner

    2015-01-01

    Full Text Available Duchenne muscular dystrophy (DMD is an X-linked recessive disorder characterized by progressive muscle weakness, with eventual loss of ambulation and premature death. The approved therapy with corticosteroids improves muscle strength, prolongs ambulation, and maintains pulmonary function. However, the osteoporotic impact of chronic corticosteroid use further impairs the underlying reduced bone mass seen in DMD, leading to increased fragility fractures of long bones and vertebrae. These serious sequelae adversely affect quality of life and can impact survival. The current clinical issues relating to bone health and bone health screening methods in DMD are presented in this review. Diagnostic studies, including biochemical markers of bone turnover and bone mineral density by dual energy X-ray absorptiometry (DXA, as well as spinal imaging using densitometric lateral spinal imaging, and treatment to optimize bone health in patients with DMD are discussed. Treatment with bisphosphonates offers a method to increase bone mass in these children; oral and intravenous bisphosphonates have been used successfully although treatment is typically reserved for children with fractures and/or bone pain with low bone mass by DXA.

  2. Bone Metastasis from Renal Cell Carcinoma

    Science.gov (United States)

    Chen, Szu-Chia; Kuo, Po-Lin

    2016-01-01

    About one-third of patients with advanced renal cell carcinoma (RCC) have bone metastasis that are often osteolytic and cause substantial morbidity, such as pain, pathologic fracture, spinal cord compression and hypercalcemia. The presence of bone metastasis in RCC is also associated with poor prognosis. Bone-targeted treatment using bisphosphonate and denosumab can reduce skeletal complications in RCC, but does not cure the disease or improve survival. Elucidating the molecular mechanisms of tumor-induced changes in the bone microenvironment is needed to develop effective treatment. The “vicious cycle” hypothesis has been used to describe how tumor cells interact with the bone microenvironment to drive bone destruction and tumor growth. Tumor cells secrete factors like parathyroid hormone-related peptide, transforming growth factor-β and vascular endothelial growth factor, which stimulate osteoblasts and increase the production of the receptor activator of nuclear factor κB ligand (RANKL). In turn, the overexpression of RANKL leads to increased osteoclast formation, activation and survival, thereby enhancing bone resorption. This review presents a general survey on bone metastasis in RCC by natural history, interaction among the immune system, bone and tumor, molecular mechanisms, bone turnover markers, therapies and healthcare burden. PMID:27338367

  3. Occupational turnover intentions among substance abuse counselors.

    Science.gov (United States)

    Rothrauff, Tanja C; Abraham, Amanda J; Bride, Brian E; Roman, Paul M

    2011-01-01

    This study examined predictor, moderator, and mediator variables of occupational turnover intention (OcTI) among substance abuse counselors. Data were obtained via questionnaires from 929 counselors working in 225 private substance abuse treatment (SAT) programs across the United States. Hierarchical multiple regression models were conducted to assess predictor, moderator, and mediator variables of OcTI. OcTI scores were relatively low on a 7-point scale, indicating that very few counselors definitely intended to leave the SAT field. Age, certification, positive perceptions of procedural and distributive justice, and hospital-based status negatively predicted OcTI. Counselors' substance use disorder-impacted history moderated the association between organizational commitment and OcTI. Organizational turnover intention partially mediated the link between organizational commitment and OcTI. Workforce stability might be achieved by promoting perceptions of advantages to working in a particular treatment program, having organizational commitment, showing appreciation for counselors' work, and valuing employees from diverse backgrounds.

  4. Analisis Pengaruh Receivable Turnover Ratio, Inventory Turnover Ratio, dan Total Assets Turnover Ratio Terhadap Earning Power pada Perusahaan Farmasi di Bursa Efek Indonesia

    OpenAIRE

    Bangun, Andri Primadana

    2011-01-01

    Tujuan dari penulisan skripsi ini adalah untuk menganalisis pengaruh rasio aktivitas dengan variabel Receivable Turnover Ratio, Inventory Turnover Ratio, dan Total Assets Turnover Ratio terhadap Earning Power perusasahaan farmasi dengan analisis regresi berganda. Jenis data yang akan diolah dan diteliti adalah data sekunder berupa laporan keuangan seperti neraca dan laporan laba-rugi serta bahan publikasi lain yang relevan dengan permasalahan yang diteliti. Tahun buku akuntansi yang dipili...

  5. Low Bone Density

    Science.gov (United States)

    ... Density Exam/Testing › Low Bone Density Low Bone Density Low bone density is when your bone density ... people with normal bone density. Detecting Low Bone Density A bone density test will determine whether you ...

  6. Stock Option Compensation and Managerial Turnover

    OpenAIRE

    Raluca Georgiana NASTASESCU

    2009-01-01

    This study examines the association between managerial turnover and equity-based compensation. I investigate whether stock options act to bond executives to their firms and whether retention of managers is a motivation of companies in designing CEO incentive contracts. The results show that stock options do negatively influence the probability of a CEO leaving the company. The monetary cost of losing the value of equity-based compensation package keeps the manager with his company. I also fin...

  7. Leadership, Perceptions, and Turnover Intentions: Why Stay?

    OpenAIRE

    Nelson, Joel A.; Daniels, Michael K.

    2014-01-01

    The purpose of the quantitative correlational study was to highlight the variable relationships between tenure, perceptions, job satisfaction, and turnover intentions for a sample consisting of individuals working for managers who were previously peers. The study incorporated a quantitative correlational structure and the rationale for choosing the structure for the initiative was to aid in the analysis of sample data gathered using Likert-type surveying tools regarding the variables chosen f...

  8. Unemployment Insurance and Job Turnover in Spain

    OpenAIRE

    Yolanda Rebollo Sanz

    2010-01-01

    The aim of this paper is to shed some light on the potential relationships between the unemployment insurance system and labour market turnover, seeking to further the traditional view that this system has only behavioural consequences for the labour supply side of the labour market. This study assumes the incentives embedded in the unemployment insurance system have a heterogeneous impact, depending on the type of labour market transition (quits versus layoffs and recalls versus new job entr...

  9. Systems turnover activities at NPP-Cernavoda

    International Nuclear Information System (INIS)

    The erection of a nuclear power plant requires the utilisation of complex Quality Assurance (QA) programs. These programs implement specific standards, procedures and laws to ensure that the plant is constructed to the highest possible safety level attainable. Some procedures and standards have a narrow field of action while others cover a large area of operation. Such is the case with the turnover procedure presented in this paper, which is one component of the QA program. (Author)

  10. CEO turnover and relative performance evaluation

    OpenAIRE

    Jenter, Dirk; Kanaan, Fadi

    2015-01-01

    This paper examines whether CEOs are fired after bad firm performance caused by factors beyond their control. Standard economic theory predicts that corporate boards filter out exogenous industry and market shocks to firm performance when deciding on CEO retention. Using a new hand-collected sample of 1,590 CEO turnovers from 1993 to 2001, we document that CEOs are significantly more likely to be dismissed from their jobs after bad industry and bad market performance. A decline in the industr...

  11. PERAN STRES KERJA DAN KEPUASAN KERJA UNTUK MENGURANGI TURNOVER INTENTION

    Directory of Open Access Journals (Sweden)

    Syarifah Nazenin

    2014-09-01

    Full Text Available Tujuan penelitian ini untuk menguji pengaruh variabel stres kerja dan kepuasan kerja pada turnover intention karyawan tetap bagian produksi. Sampel penelitian ini adalah 86 responden, menggunakan metode Slovin dengan teknik probability sampling dengan jenis proportionate random sampling. Berdasarkan hasil penelitian, menunjukkan bahwa stres kerja berpengaruh positif signifikan pada turnover intention. Kemudian, kepuasan kerja berpengaruh negatif signifikan. Penelitian ini menyimpulkan, bahwa stres kerja berpengaruh positif dan signifikan pada turnover intention karyawan dan kepuasan kerja berpengaruh negatif dan signifikan terhadap turnover intention karyawan. Implikasi manajerial yang bisa dilakukan adalah dengan pengurangan tingkat stres karyawan dan membuat program untuk tujuan menekan turnover intention, seperti kesempatan promosi dan meningkatkan reward karyawan. The purpose of this study conducted to examine the effect of work stress and job satisfaction on turnover intention of employee in production department. The sample was 86 respondent, using Slovin method with proportionate random sampling technique. The result showed that job stress has a positive effect on turnover intention while job satisfaction has a negative effect on turnover intention. This study conclude that job stress has positive and significant impact on employee turnover intention and job satisfaction significantly and negatively related to turnover intention of employees. Therefore, it is recommended to managerial level people to reduce stress levels in employees and to create a program for pressing turnover intention, such as promotional opportunities and improve employee rewards.

  12. Generational differences in registered nurse turnover.

    Science.gov (United States)

    LeVasseur, Sandra A; Wang, Chen-Yen; Mathews, Barbara; Boland, Mary

    2009-08-01

    The chronic nature of the nursing workforce shortage in the United States is a continuing concern. As the nationwide gap between supply and demand grows, it remains unknown what impact turnover will have on nursing, access to care, and efforts to improve quality and safety of health care. It also remains unclear whether the recent turnover trends among new graduate registered nurses differ from past generational cohorts of new nurses. The aims of this study were to identify the reasons why registered nurses turnover by generational cohort (Veterans, Baby Boomers, and GenXMs) and to compare the length of time nurses were employed in their first five nursing positions by generational cohort. The findings suggest the three generational cohorts displayed similar reasons for leaving nursing positions with relocation, career advancement, and personal/family reasons reported most frequently. Except for the first nursing position, significant generational effects were found in the length of time Veterans, Baby Boomer, and GenXMs stayed employed in their nursing positions. It remains unknown why the GenXMs displayed a significantly shorter length of employment time in their second, third, fourth, and fifth nursing positions. The decline in length of employment time displayed in both the Baby Boomers and GenXMs may be an issue of concern requiring future research. PMID:20026454

  13. High-resolution computed tomography of the temporal bone. Part 1.: normal anatomy; Kosc skroniowa w tomografii komputerowej wysokiej rozdzielczosci. Czesc 1.: anatomia prawidlowa

    Energy Technology Data Exchange (ETDEWEB)

    Grzegorzewski, M.; Boron, Z.; Burzynska-Makuch, M. [Katedra i Zaklad Radiologii i Diagnostyki Narzadowej, Akademia Medyczna, Bydgoszcz (Poland)

    1995-12-31

    Normal anatomy of the temporal bone in transverse and coronal sections was presented. CT studies were performed using high-resolution program. The images of an asymptomatic ear of 2 patients were selected from 68 cases examined on account of various otological diseases. All the sections showed as many as 68 anatomic structures. (author) 5 refs, 2 figs

  14. FRACTURE NASAL BONES

    OpenAIRE

    Balasubramanian Thaigarajan; Venkatesan Ulaganathan

    2013-01-01

    Nose is the most prominent part of the face, hence it is likely to be the most common structure to be injured in the face. Although fractures involving the nasal bones are very common, it is often ignored by the patient. Patients with fractures of nasal bone will have deformity, tenderness, haemorrhage, edema, ecchymosis, instability, and crepitation. These features may be present in varying combinations. This article discusses the pathophysiology of these fractures, role of radiography a...

  15. Fracture Nasal Bone

    OpenAIRE

    Balasubramanian, Thiagarajan; Venkatesan, Ulaganathan

    2013-01-01

    Nose is the most prominent part of the face, hence it is likely to be the most common structure to be injured in the face. Although fractures involving the nasal bones are very common, it is often ignored by the patient. Patients with fractures of nasal bone will have deformity, tenderness, haemorrhage, edema, ecchymosis, instability, and crepitation. These features may be present in varying combinations. This article discusses the pathophysiology of these fractures, role of radiography and u...

  16. Cell interactions in bone tissue engineering

    OpenAIRE

    Pirraco, Rogério; Marques, A. P.; Reis, R. L.

    2010-01-01

    Bone fractures, where the innate regenerative bone response is compromised, represent between 4 and 8 hundred thousands of the total fracture cases, just in the United States. Bone tissue engineering (TE) brought the notion that, in cases such as those, it was preferable to boost the healing process of bone tissue instead of just adding artificial parts that could never properly replace the native tissue. However, despite the hype, bone TE so far could not live up to its promises and...

  17. Cell interactions in bone tissue engineering

    OpenAIRE

    Pirraco, R. P.; Marques, A. P.; Reis, R. L.

    2009-01-01

    Abstract Bone fractures, where the innate regenerative bone response is compromised, represent between 4 and 8 hundred thousands of the total fracture cases, just in the United States. Bone tissue engineering (TE) brought the notion that, in cases such as those, it was preferable to boost the healing process of bone tissue instead of just adding artificial parts that could never properly replace the native tissue. However, despite the hype, bone TE so far could not live up to its promises and...

  18. [Connective tissue in non-union and pseudarthrosis of long bones. Part II: cavity of false joints in dogs (author's transl)].

    Science.gov (United States)

    Rohe, K; Bierther, M; Becker, W; Sarvestani, M

    1980-12-01

    Pseudarthrotic cavity is surrounded by joint capsule-like connective tissue as well as by the locked-up bone ends. Macroscopic and microscopic examinations indicate instability as a traumatic factor to the surrounding tissues, leading to tears and clefts covered by fibrin and erythrocyte deposits. Below, cell-layers consisting of fibroblasts and histiocytes are formed, which become comparable to stratum synoviale of normal joint especially in areas with constant mechanical stimulus like sliding and little pressure without considerable traumatic effect. Where bone ends reach like lever-arms far into the peripseudarthrotic tissue and mechanical stress of abnormal mobility is of adequate permanent traumatic effect, vascularisation is not visible and regressive, necrobiotic alterations are predominant. In areas with presumable more pressure, with little or no vascularisation, woven cartilage-like partially calcified tissues are formed. Where osteotomized bones are pressed upon each other with instability an intensive remodeling with resorption and rebuilding of bone trabeculae is visible. Muscle interposits degenerate within the continuously injured and scarcely vasculated osteotomized area, and are replaced by tight connective tissues as well as walled-in by bone trabeculae. By reforming abundant collagenous fibres the pseudarthrosis becomes more and more tight. In this way there is a reduction of the functional stimulus abnormal mobility, which induces the local connective tissue to differentiate into joint-like structures, comparable to a mechanism of "self-limitation". One animal was observed up to 48 months after osteotomy. Without therapeutic immobilisation bony consolidation and corticalisation was present in the former pseudarthrotic region, joint capsule-like tissues were no more demonstrable. PMID:7222952

  19. Bone balance within a cortical BMU: local controls of bone resorption and formation.

    Directory of Open Access Journals (Sweden)

    David W Smith

    Full Text Available Maintaining bone volume during bone turnover by a BMU is known as bone balance. Balance is required to maintain structural integrity of the bone and is often dysregulated in disease. Consequently, understanding how a BMU controls bone balance is of considerable interest. This paper develops a methodology for identifying potential balance controls within a single cortical BMU. The theoretical framework developed offers the possibility of a directed search for biological processes compatible with the constraints of balance control. We first derive general control constraint equations and then introduce constitutive equations to identify potential control processes that link key variables that describe the state of the BMU. The paper describes specific local bone volume balance controls that may be associated with bone resorption and bone formation. Because bone resorption and formation both involve averaging over time, short-term fluctuations in the environment are removed, leaving the control systems to manage deviations in longer-term trends back towards their desired values. The length of time for averaging is much greater for bone formation than for bone resorption, which enables more filtering of variability in the bone formation environment. Remarkably, the duration for averaging of bone formation may also grow to control deviations in long-term trends of bone formation. Providing there is sufficient bone formation capacity by osteoblasts, this leads to an extraordinarily robust control mechanism that is independent of either osteoblast number or the cellular osteoid formation rate. A complex picture begins to emerge for the control of bone volume. Different control relationships may achieve the same objective, and the 'integration of information' occurring within a BMU may be interpreted as different sets of BMU control systems coming to the fore as different information is supplied to the BMU, which in turn leads to different observable

  20. Bone balance within a cortical BMU: local controls of bone resorption and formation.

    Science.gov (United States)

    Smith, David W; Gardiner, Bruce S; Dunstan, Colin

    2012-01-01

    Maintaining bone volume during bone turnover by a BMU is known as bone balance. Balance is required to maintain structural integrity of the bone and is often dysregulated in disease. Consequently, understanding how a BMU controls bone balance is of considerable interest. This paper develops a methodology for identifying potential balance controls within a single cortical BMU. The theoretical framework developed offers the possibility of a directed search for biological processes compatible with the constraints of balance control. We first derive general control constraint equations and then introduce constitutive equations to identify potential control processes that link key variables that describe the state of the BMU. The paper describes specific local bone volume balance controls that may be associated with bone resorption and bone formation. Because bone resorption and formation both involve averaging over time, short-term fluctuations in the environment are removed, leaving the control systems to manage deviations in longer-term trends back towards their desired values. The length of time for averaging is much greater for bone formation than for bone resorption, which enables more filtering of variability in the bone formation environment. Remarkably, the duration for averaging of bone formation may also grow to control deviations in long-term trends of bone formation. Providing there is sufficient bone formation capacity by osteoblasts, this leads to an extraordinarily robust control mechanism that is independent of either osteoblast number or the cellular osteoid formation rate. A complex picture begins to emerge for the control of bone volume. Different control relationships may achieve the same objective, and the 'integration of information' occurring within a BMU may be interpreted as different sets of BMU control systems coming to the fore as different information is supplied to the BMU, which in turn leads to different observable BMU behaviors.

  1. Bone Cancer

    Science.gov (United States)

    ... cancer. Surgery is often the main treatment for bone cancer. Other treatments may include amputation, chemotherapy, and radiation therapy. Because bone cancer can come back after treatment, regular follow-up visits are important. NIH: National ...

  2. Turnover of grain legume N rhizodeposits and effect of rhizodeposition on the turnover of crop residues

    DEFF Research Database (Denmark)

    Mayer, J.; Buegger, F.; Jensen, E.S.;

    2004-01-01

    The turnover of N derived from rhizodeposition of faba bean (Vicia faba L.), pea (Pisum sativum L.) and white lupin (Lupinus albus L.) and the effects of the rhizodeposition on the subsequent C and N turnover of its crop residues were investigated in an incubation experiment (168 days, 15 degrees......C). A sandy loam soil for the experiment was either stored at 6 degreesC or planted with the respective grain legume in pots. Legumes were in situ N-15 stem labelled during growth and visible roots were removed at maturity. The remaining plant-derived N in soil was defined as N rhizodeposition....... In the experiment the turnover of C and N was compared in soils with and without previous growth of three legumes and with and without incorporation of crop residues. After 168 days, 21% (lupin), 26% (faba bean) and 27% (pea) of rhizodeposition N was mineralised in the treatments without crop residues. A smaller...

  3. Low-dose hydrocortisone (HC) replacement therapy is associated with improved bone remodeling balance in hypopituitary subjects

    LENUS (Irish Health Repository)

    Behan, L A

    2011-06-01

    The effect of commonly used glucocorticoid replacement regimens on bone health in hypopituitary subjects is not well known. We aimed to assess the effect of 3 hydrocortisone (HC) replacement dose regimens on bone turnover in this group.10 hypopituitary men with severe ACTH deficiency were randomised in a crossover design to 3 HC dose regimens, Dose A (20mg mane, 10mg tarde), Dose B (10mg twice daily) and Dose C (10mg mane, 5mg tarde). Following 6 weeks of each regimen participants underwent fasting sampling of bone turnover markers.Data from matched controls were used to produce a Z score for subject bone formation and resorption markers and to calculate the bone remodeling balance (formation Z score-resorption Z score) and turnover index ((formation Z + resorption Z)\\/2). A positive bone remodeling balance with increased turnover is consistent with a favourable bone cycle. Data are expressed as median (range).The Pro Collagen Type 1 Peptide (PINP) bone formation Z-score was significantly increased in Dose C, (1.805 (-0.6-10.24)) compared to Dose A (0.035 (-1.0-8.1)) p<0.05 while there was no difference in the C-terminal crosslinking telopeptide (CTx) resorption Z score. The bone remodeling balance was significantly lower for dose A -0.02 (-1.05-4.12) compared to dose C 1.13 (0.13-6.4) (p<0.05). Although there was a trend to an increased bone turnover index with the lower dose regimen, this was not statistically significant.Low dose HC replacement (10mg mane\\/5 mg tarde) was associated with increased bone formation and improved bone remodeling balance which is associated with a more favourable bone cycle. This may have a long term beneficial effect on bone health.

  4. Ubiquitin-dependent trafficking and turnover of ionotropic glutamate receptors

    Directory of Open Access Journals (Sweden)

    Marisa S Goo

    2015-10-01

    Full Text Available Changes in synaptic strength underlie the basis of learning and memory and are controlled, in part, by the insertion or removal of AMPA-type glutamate receptors at the postsynaptic membrane of excitatory synapses. Once internalized, these receptors may be recycled back to the plasma membrane by subunit-specific interactions with other proteins or by post-translational modifications such as phosphorylation. Alternatively, these receptors may be targeted for destruction by multiple degradation pathways in the cell. Ubiquitination, another post-translational modification, has recently emerged as a key signal that regulates the recycling and trafficking of glutamate receptors. In this review, we will discuss recent findings on the role of ubiquitination in the trafficking and turnover of ionotropic glutamate receptors and plasticity of excitatory synapses.

  5. The effects of untreated and treated HIV infection on bone disease.

    LENUS (Irish Health Repository)

    Cotter, Aoife G

    2013-11-20

    Low bone mineral density (BMD) is common in those with HIV, associated with higher bone turnover and a higher prevalence of fractures. This review explores low BMD in HIV, focusing on underlying mechanisms and relationships between low BMD and HIV infection, immune dysfunction, and antiretroviral therapy (ART).

  6. Bone marrow derivation of pericryptal myofibroblasts in the mouse and human small intestine and colon

    OpenAIRE

    Brittan, M; Hunt, T.; Jeffery, R.; Poulsom, R.; Forbes, S.J.; K. Hodivala-Dilke; Goldman, J.; Alison, M R; Wright, N. A.

    2002-01-01

    Background and aims: In order to establish whether extraintestinal cells contribute to the turnover and repair of gastrointestinal tissues, we studied the colons and small intestines of female mice that had received a male bone marrow transplant, together with gastrointestinal biopsies from female patients that had developed graft versus host disease after receiving a bone marrow transplant from male donors.

  7. Serum biomarkers of bone metabolism in castration resistant prostate cancer patients with skeletal metastases

    Science.gov (United States)

    Background. Prior studies suggest that elevated markers of bone turnover are prognostic for poor survival in castration resistant prostate cancer (CRPC). The predictive role of these markers relative to bone-targeted therapy is unknown. We prospectively evaluated the prognostic and predictive value ...

  8. Evidence that increased calcium intake does not prevent early postmenopausal bone loss

    DEFF Research Database (Denmark)

    Hosking, D J; Ross, P D; Thompson, D E;

    1998-01-01

    intake was recorded, and bone mineral density (BMD) (in the lumbar spine, total body, forearm, and hip) and biochemical markers of bone turnover (serum total alkaline phosphatase, serum osteocalcin, and urinary N-telopeptide crosslink levels) were measured at baseline and annually thereafter. Women whose...

  9. Alveolar bone loss in osteoporosis: a loaded and cellular affair?

    Science.gov (United States)

    Jonasson, Grethe; Rythén, Marianne

    2016-01-01

    Maxillary and mandibular bone mirror skeletal bone conditions. Bone remodeling happens at endosteal surfaces where the osteoclasts and osteoblasts are situated. More surfaces means more cells and remodeling. The bone turnover rate in the mandibular alveolar process is probably the fastest in the body; thus, the first signs of osteoporosis may be revealed here. Hormones, osteoporosis, and aging influence the alveolar process and the skeletal bones similarly, but differences in loading between loaded, half-loaded, and unloaded bones are important to consider. Bone mass is redistributed from one location to another where strength is needed. A sparse trabeculation in the mandibular premolar region (large intertrabecular spaces and thin trabeculae) is a reliable sign of osteopenia and a high skeletal fracture risk. Having dense trabeculation (small intertrabecular spaces and well-mineralized trabeculae) is generally advantageous to the individual because of the low fracture risk, but may imply some problems for the clinician.

  10. Alveolar bone loss in osteoporosis: a loaded and cellular affair?

    Science.gov (United States)

    Jonasson, Grethe; Rythén, Marianne

    2016-01-01

    Maxillary and mandibular bone mirror skeletal bone conditions. Bone remodeling happens at endosteal surfaces where the osteoclasts and osteoblasts are situated. More surfaces means more cells and remodeling. The bone turnover rate in the mandibular alveolar process is probably the fastest in the body; thus, the first signs of osteoporosis may be revealed here. Hormones, osteoporosis, and aging influence the alveolar process and the skeletal bones similarly, but differences in loading between loaded, half-loaded, and unloaded bones are important to consider. Bone mass is redistributed from one location to another where strength is needed. A sparse trabeculation in the mandibular premolar region (large intertrabecular spaces and thin trabeculae) is a reliable sign of osteopenia and a high skeletal fracture risk. Having dense trabeculation (small intertrabecular spaces and well-mineralized trabeculae) is generally advantageous to the individual because of the low fracture risk, but may imply some problems for the clinician. PMID:27471408

  11. Scintigraphic imaging and turnover studies with iodine-131 labelled serum amyloid P component in systemic amyloidosis

    International Nuclear Information System (INIS)

    Radiolabelled serum amyloid P component (SAP) is a specific tracer for amyloid. Iodine-123 has ideal physical characteristics for scintigraphy but is expensive and not widely available. Here we report serial imaging and turnover studies in which we labelled SAP with iodine-131, a cheap alternative isotope which would be expected to yield poorer images but permit more prolonged turnover measurements. Imaging and plasma clearance and whole body retention (WBR) of tracer were studied for up to 7 days in ten patients with proven systemic AL amyloidosis and two patients in whom the diagnosis was suspected, after i.v. administration of about 37 MBq of 131I-SAP. Normal blood pool images were obtained in the latter two subjects and amyloidosis was subsequently refuted histologically. WBR at 48 h was 65% of the injected dose (i.d.). Among the other ten patients, amyloid deposits were identified in the spleen in eight cases, liver in five and kidneys in four; other sites that gave positive results included bone, joints and soft tissues, and the myocardium in one case. Up to 95% of the tracer localised into amyloid within 6-h, and the values for WBR became progressively more discriminating during the study period, exceeding the normal reference value (131I-SAP produced diagnostic scans in every patient in this series and, coupled with the detailed turnover information, is adequate for monitoring disease progress. (orig.)

  12. Labour Turnover in the Hospitality Industry

    OpenAIRE

    Ersan Suria Pranoto

    2011-01-01

    Labour turnover are inevitable and many businesses and industries are dealing with this issue every single day. It is also a great issue in the Hospitality Industry, the intensity were varies according to the size of the establishment, some are low and many is as high as the height of their buildings. The fact also stated that workers in the hospitality industry in the early stage of their career expect to move from one job to another, creating a very low desirability of steady workplaces and...

  13. Endogenous Turnover of Cyanogenic Glycosides in Plants

    DEFF Research Database (Denmark)

    Picmanova, Martina

    with noncyanogenic compounds glaringly resembling their structures. In order to examine the spatial as well as temporal presence and abundance of the putative turnover products of CNglcs, comparative metabolic profiling using LC-MS/MS was performed in three cyanogenic crops – cassava, almond and sorghum. This work...... of the proposed catabolic route, even though the enzymes involved remain elusive. Testing of heterologously expressed and purified nitrilases and nitrilase-related enzymes from cassava and almond, including NIT4s, glutamine-dependent NAD+ synthetase (QNS) and a newly discovered nucleus-localized nitrilase...

  14. Bone effects of space flight analysis by quantum concept of bone remodelling

    Science.gov (United States)

    Parfitt, A. M.

    During the manned Skylab flights mineral losses from the calcaneum and changes in external calcium balance were in the ranges found for healthy subjects at bedrest. Calcium balance reached a nadir of -200 mg/day by two months with no change thereafter; the negative balance was due to increased urinary excretion with no change in net absorption. The total calcium loss averaged 18 g in the longest flight of 84 days; the densitiometric data suggested that about two-thirds of this came from trabecular bone and about one-third from cortical bone. These data could represent reversible bone loss due to increased birth rate of normal osteoclasts and osteoblasts and consequent increase in bone turnover and in reversible mineral deficit, or irreversible bone loss due to overactive osteoclasts and/or underactive osteoblasts. If the former explanation is correct, significant bone loss is unlikely whatever the duration of future flights, except in older persons already losing bone; if the latter explanation is correct, space flights longer than six months may lead to a significant increase in fracture risk in later life. Neither terrestrial immobilization nor unwilling animals in orbit are ideal models for the effects of space flight on human bone. To choose between reversible and irreversible mechanisms of bone loss, and to determine the effects of space flight on lifelong fracture risk, future astronauts and cosmonauts must undergo adequate histologic study of bone after in vivo tetracycline labeling.

  15. Vitamin D, parathyroid hormone levels and bone mineral density in community-dwelling older women: The Rancho Bernardo Study

    OpenAIRE

    von Mühlen, Denise G; Greendale, Gail A.; Cedric F Garland; Wan, Lori; Barrett-Connor, Elizabeth

    2005-01-01

    Vitamin D (25(OH)D) increases the efficiency of intestinal calcium absorption. Low levels of serum calcium stimulate the secretion of parathyroid hormone (PTH), which maintains serum calcium levels at the expense of increased bone turnover, bone loss and increased risk of fractures. We studied the association between 25(OH)D and PTH levels, and their associations with bone mineral density (BMD), bone loss, and prevalence of hip fractures in 615 community-dwelling postmenopausal aged 50 - 97 y...

  16. Bone Canopies in Pediatric Renal Osteodystrophy

    DEFF Research Database (Denmark)

    Pereira, Renata C; Levin Andersen, Thomas; Friedman, Peter A;

    2016-01-01

    and their association with biochemical and bone histomorphometric parameters in 106 pediatric chronic kidney disease (CKD) patients (stage 2-5) across the spectrum of ROD. Canopies in CKD patients often appeared as thickened multilayered canopies, similar to previous reports in patients with primary hyperparathyroidism....... This finding contrasts with the thin appearance reported in healthy individuals with normal kidney function. Furthermore, canopies in pediatric CKD patients showed immunoreactivity to the PTH receptor (PTHR1) as well as to the receptor activator of nuclear factor kappa-B ligand (RANKL). The number of surfaces......Pediatric renal osteodystrophy (ROD) is characterized by changes in bone turnover, mineralization, and volume that are brought about by alterations in bone resorption and formation. The resorptive and formative surfaces on the cancellous bone are separated from the marrow cavity by canopies...

  17. CEO Turnover: More Evidence on the Role of Performance Expectations

    OpenAIRE

    Humphreys, Brad; Paul, Rodney; Weinbach, Andrew

    2011-01-01

    Previous research on CEO turnover indicates that a number of factors, including age, firm performance, and expected firm performance affect CEO turnover. Measurement of expected performance in these studies is typically based on investment analysts’ forecasts of earnings; these expectations potentially suffer from a number of problems, including the tendency for CEOs to “manage” analysts’ expectations. We examine the relationship between performance expectations and CEO turnover using data fr...

  18. Peranan Bullying di Tempat Kerja Terhadap Intensi Turnover Pada Karyawan

    OpenAIRE

    Tarigan, Santri Permana

    2015-01-01

    Bullying behavior is repeated behavior that is performed by a person or group of persons to another person or another group which aims to humiliate, offensive, and intimidate. One of the effects of bullying behavior is turnover intention. This study aims to know the role of workplace bullying toward employees turnover intention. This study involved 67 employees were selected through purposive sampling technique. Measuring tool used turnover intention scale and workplace bullyin...

  19. Does Total Rewards Reduce the Core Employees’ Turnover Intention?

    OpenAIRE

    Zhoutao Cao; Jinxi Chen; Yixiao Song

    2013-01-01

    The turnover of core employees is great lost for industrial companies, so that the research of turnover Intention(TI) is critical to enterprise. Recently, the researches discuss the factors that affect turnover invention fromdifferent views. Based on the concept of total rewards (TR) we go deep into the influencing factors. In this paper,we used ULR and hierarchical regression analysis to build model with organizational justice (OJ) as moderatorvariable. Results showed that the five elements ...

  20. Selenoprotein P is the essential selenium transporter for bones.

    Science.gov (United States)

    Pietschmann, Nicole; Rijntjes, Eddy; Hoeg, Antonia; Stoedter, Mette; Schweizer, Ulrich; Seemann, Petra; Schomburg, Lutz

    2014-05-01

    Selenium (Se) plays an important role in bone physiology as best reflected by Kashin-Beck disease, an endemic Se-dependent osteoarthritis. Bone development is delayed in children with mutations in SECIS binding protein 2 (SBP2), a central factor for selenoprotein biosynthesis. Circulating selenoprotein P (SePP) is positively associated with bone turnover in humans, yet its function for bone homeostasis is not known. We have analysed murine models of altered Se metabolism. Most of the known selenoprotein genes and factors needed for selenoprotein biosynthesis are expressed in bones. Bone Se is not associated with the mineral but exclusively with the organic matrix. Genetic ablation of Sepp-expression causes a drastic decline in serum (25-fold) but only a mild reduction in bone (2.5-fold) Se concentrations. Cell-specific expression of a SePP transgene in hepatocytes efficiently restores bone Se levels in Sepp-knockout mice. Of the two known SePP receptors, Lrp8 was detected in bones while Lrp2 was absent. Interestingly, Lrp8 mRNA concentrations were strongly increased in bones of Sepp-knockout mice likely in order to counteract the developing Se deficiency. Our data highlight SePP as the essential Se transporter to bones, and suggest a novel feedback mechanism for preferential uptake of Se in Se-deprived bones, thereby contributing to our understanding of hepatic osteodystrophy and the consistent bone phenotype observed in subjects with inherited selenoprotein biosynthesis mutations. PMID:24626785

  1. Turnover of dhurrin in green sorghum seedlings

    International Nuclear Information System (INIS)

    The turnover of dhurrin in green seedlings of Sorghum bicolor (Linn) Moench var Redland x Greenleaf, Sudan 70 has been investigated using glyphosate and pulse-labeling studies with 14C-tyrosine and [14C]shikimic acid. The rate of dhurrin breakdown was 4.8 nanomoles per hour in the shoot and 1.4 nanomoles per hour in the root. The rate of dhurrin accumulation in the shoot of 4- to 5-day-old seedlings was high but decreased with age until at the peak period of dhurrin accumulation, the rates of dhurrin synthesis and breakdown were equal. Using a first order equation (an approximation) the rate of dhurrin synthesis (which equals accumulation plus breakdown rates) was 17.4 nanomoles per hour in the shoot and 4.1 nanomoles per hour in the root. In both tissues, the breakdown rate was between 27 and 34% of their synthetic capacity within the experimental period. Dhurrin synthesis in green sorghum seedlings occurred in both the light and dark photoperiods but was faster in the dark period. The result is discussed in relation to the possible metabolic roles of the turnover

  2. Definitions of the real estate turnover system

    Directory of Open Access Journals (Sweden)

    Vitaliy A. Petrushkin

    2014-01-01

    Full Text Available Objective to study the principles and the role of legislative definitions within the various research methods for modeling functions of legal models of the civil rights objects. Methods method of comparative analysis and abstract method. Results the analysis of scientific approaches defines simulation as a method of research which remains weak in legal sciences its relevance and topicality are ignored. Scientific novelty the modeling principles in the theory of law are not fully established in connection with which the author gives the definition of the legal modeling factors in the sphere of the turnover of the civil rights objects and their classification. Practical value the identified approaches provide for the possibility to study the principles of development of the approaches functioning mechanism as well as to map the ideal model with really existing social relations in the sphere of real estate turnover. In addition the author proposes systematization of real contracts as to their content ndash the type of property rights the transfer of which is the subject of agreement. The work expands the concept of quotproperty lawquot in statics as a result of comparison of the quotlegal modelquot concept with other similar terms. The conclusion is made about the existence of separate legal category in modern science.

  3. Dynamics of Adipocyte Turnover in Humans

    Energy Technology Data Exchange (ETDEWEB)

    Spalding, K; Arner, E; Westermark, P; Bernard, S; Buchholz, B; Bergmann, O; Blomqvist, L; Hoffstedt, J; Naslund, E; Britton, T; Concha, H; Hassan, M; Ryden, M; Frisen, J; Arner, P

    2007-07-16

    Obesity is increasing in an epidemic fashion in most countries and constitutes a public health problem by enhancing the risk for cardiovascular disease and metabolic disorders such as type 2 diabetes. Owing to the increase in obesity, life expectancy may start to decrease in developed countries for the first time in recent history. The factors determining fat mass in adult humans are not fully understood, but increased lipid storage in already developed fat cells is thought to be most important. We show that adipocyte number is a major determinant for the fat mass in adults. However, the number of fat cells stays constant in adulthood in lean and obese and even under extreme conditions, indicating that the number of adipocytes is set during childhood and adolescence. To establish the dynamics within the stable population of adipocytes in adults, we have measured adipocyte turnover by analyzing the integration of {sup 14}C derived from nuclear bomb tests in genomic DNA. Approximately 10% of fat cells are renewed annually at all adult ages and levels of body mass index. Neither adipocyte death nor generation rate is altered in obesity, suggesting a tight regulation of fat cell number that is independent of metabolic profile in adulthood. The high turnover of adipocytes establishes a new therapeutic target for pharmacological intervention in obesity.

  4. Impacto óseo en el tratamiento del cáncer de mama: PARTE II Bone impact in breast cancer treatment

    Directory of Open Access Journals (Sweden)

    M. Drnovsek

    2011-09-01

    Full Text Available El cáncer de mama es uno de los tumores más frecuentes en la mujer. Más del 70 % de estas pacientes presenta en la lesión marcación positiva para receptor de estrógeno, receptor de progesterona o ambos En la última década la mortalidad por cáncer de mama ha disminuido entre 6-8 %. Ésto podría deberse a la detección temprana de la lesión, al tratamiento coadyuvante con quimioterapia y tratamiento hormonal, ya sea con bloqueo de estrógenos o ablación ovárica. La depleción de estrógenos establece incremento de la resorción ósea, disminución de la masa ósea y aumento en la tasa de fractura por osteoporosis. La introducción de los inhibidores de la aromatasa ofrece resultados promisorios en el tratamiento del estadio temprano del cáncer de mama. Sin embargo varios estudios clínicos han demostrado que la deprivación de estrógenos inducida por los mismos daña seriamente la salud ósea. Debido a esto, la evaluación sistemática de estas pacientes que incluye la medición de la masa ósea, el estudio del metabolismo mineral y la determinación de factores de riesgo para osteoporosis, sería necesaria para introducir medidas de prevención y/o tratamiento. El uso de bifosfonatos podría ser de utilidad ya que aumenta la masa ósea y reduce la remodelación ósea, aunque no ha sido demostrada su utilidad en reducir la tasa de fractura en este grupo de pacientes.Breast cancer is one of the most frequent tumors in women. More than 70 % of these patients develop endocrine-responsive disease with estrogen receptor-positive, progesterone receptor-positive tumors or both. In the last decade, breast cancer mortality has decreased by 6-8 %. This could be due to early screening and to adjuvant treatment with chemotherapy as well as hormonal treatment, either with estrogen blockage or ovary ablation. Estrogen depletion implies an increase in bone resorption, bone mass decrease and growth of the osteoporotic fractures The introduction of

  5. Hyperhomocysteinemia decreases bone blood flow

    Directory of Open Access Journals (Sweden)

    Neetu T

    2011-01-01

    Full Text Available Neetu Tyagi*, Thomas P Vacek*, John T Fleming, Jonathan C Vacek, Suresh C TyagiDepartment of Physiology and Biophysics, School of Medicine, University of Louisville, Louisville, KY, USA *These authors have equal authorshipAbstract: Elevated plasma levels of homocysteine (Hcy, known as hyperhomocysteinemia (HHcy, are associated with osteoporosis. A decrease in bone blood flow is a potential cause of compromised bone mechanical properties. Therefore, we hypothesized that HHcy decreases bone blood flow and biomechanical properties. To test this hypothesis, male Sprague–Dawley rats were treated with Hcy (0.67 g/L in drinking water for 8 weeks. Age-matched rats served as controls. At the end of the treatment period, the rats were anesthetized. Blood samples were collected from experimental or control rats. Biochemical turnover markers (body weight, Hcy, vitamin B12, and folate were measured. Systolic blood pressure was measured from the right carotid artery. Tibia blood flow was measured by laser Doppler flow probe. The results indicated that Hcy levels were significantly higher in the Hcy-treated group than in control rats, whereas vitamin B12 levels were lower in the Hcy-treated group compared with control rats. There was no significant difference in folate concentration and blood pressure in Hcy-treated versus control rats. The tibial blood flow index of the control group was significantly higher (0.78 ± 0.09 flow unit compared with the Hcy-treated group (0.51 ± 0.09. The tibial mass was 1.1 ± 0.1 g in the control group and 0.9 ± 0.1 in the Hcy-treated group. The tibia bone density was unchanged in Hcy-treated rats. These results suggest that Hcy causes a reduction in bone blood flow, which contributes to compromised bone biomechanical properties.Keywords: homocysteine, tibia, bone density

  6. Ichthyosaurs from the French Rhaetian indicate a severe turnover across the Triassic-Jurassic boundary

    Science.gov (United States)

    Fischer, Valentin; Cappetta, Henri; Vincent, Peggy; Garcia, Géraldine; Goolaerts, Stijn; Martin, Jeremy E.; Roggero, Daniel; Valentin, Xavier

    2014-12-01

    Mesozoic marine reptiles went through a severe turnover near the end of the Triassic. Notably, an important extinction event affected ichthyosaurs, sweeping a large part of the group. This crisis is, however, obscured by an extremely poor fossil record and is regarded as protracted over the entire Norian-earliest Jurassic interval, for the lack of a more precise scenario. The iconic whale-sized shastasaurid ichthyosaurs are regarded as early victims of this turnover, disappearing by the middle Norian. Here we evaluate the pattern of this turnover among ichthyosaurs by analysing the faunal record of two Rhaetian localities. One locality is Autun, eastern France; we rediscovered in this material the holotypes or partial `type' series of Rachitrema pellati, Actiosaurus gaudryi, Ichthyosaurus rheticus, Ichthyosaurus carinatus and Plesiosaurus bibractensis; a revised taxonomic scheme is proposed. The second assemblage comes from a new locality: Cuers, southeastern France. Both these assemblages provide several lines of evidence for the presence of shastasaurid-like ichthyosaurs in the Rhaetian of Europe. These occurrences suggest that both the demise of shastasaurids and the sudden radiation of neoichthyosaurians occurred within a short time window; this turnover appears not only more abrupt but also more complex than previously postulated and adds a new facet of the end-Triassic mass extinction.

  7. [Connective tissue in non-union and pseudarthrosis of long bones. Part III: comparative examination of human false joints (author's transl)].

    Science.gov (United States)

    Rohe, K; Bierther, M; Becker, W; Sarvestani, M

    1980-12-01

    Nontreatment of far dislocated fractures of long bones is seldom, fortunately. In comparison to our animal experiments tissue samples from only one patient with similar conditions could be examined by light- and transmission electron microscopy. Microscopic findings are similar to those of animal experiments. Pathologic pseudarthrotic conditions caused by abnormal mobility can be taken as a model for observing reformation of connective tissue. In general tissue dynamics are the same as those known from the ontogeny of connective tissue. The influence of abnormal mobility to pseudarthrosis formation is discussed. PMID:7222953

  8. Functional bone marrow scintigraphy in psoriatics

    International Nuclear Information System (INIS)

    24 psoriatics as well as 24 normal healthy adults were studied by functional bone marrow scintigraphy using Tc-99m-labeled human serum albumin millimicrospheres (Tc-99m-HSA-MM). Functional bone marrow scintigraphy is an in vivo test system for the assessment of various functional properties of fixed macrophages. 58% of psoriatics who had no systemic drug treatment demonstrated peripheral extension of the bone marrow space indicating hyperplasia of bone marrow macrophages. This phenomenon could be observed only in one normal subject who was a high-performance sportsman. 83% (n=6) of psoriatics with cirrhosis of liver demonstrated bone marrow extension. The 'capacity' of bone marrow macrophages to engulf Tc-99m-HSA-MM ('uptake ratio') was diminished in 42% of non-treated as well as 66% of psoriatics treated with aromatic retinoid. The phagocytic and proteolytic turnover of Tc-99m-HSA-MM in bone marrow, spleen, and liver was found to be accelerated in 66% of non-treated psoriatics, normal, accelerated or delayed in psoriatics treated with aromatic retinoid as well as considerably delayed in all of the psoriatics with cirrhosis of liver. Functional bone marrow scintigraphy proved to be an appropriate in vivo test system to reveal abnormalities of fixed macrophages in psoriatics. Furthermore, theratpeutic effects as well as influences of pre-existing disorders on different macrophage populations can be assessed. (Author)

  9. Effect of chronic metabolic acidosis on bone density and bone architecture in vivo in rats.

    Science.gov (United States)

    Gasser, Jürg A; Hulter, Henry N; Imboden, Peter; Krapf, Reto

    2014-03-01

    Chronic metabolic acidosis (CMA) might result in a decrease in vivo in bone mass based on its reported in vitro inhibition of bone mineralization, bone formation, or stimulation of bone resorption, but such data, in the absence of other disorders, have not been reported. CMA also results in negative nitrogen balance, which might decrease skeletal muscle mass. This study analyzed the net in vivo effects of CMA's cellular and physicochemical processes on bone turnover, trabecular and cortical bone density, and bone microarchitecture using both peripheral quantitative computed tomography and μCT. CMA induced by NH4Cl administration (15 mEq/kg body wt/day) in intact and ovariectomized (OVX) rats resulted in stable CMA (mean Δ[HCO3(-)]p = 10 mmol/l). CMA decreased plasma osteocalcin and increased TRAP5b in intact and OVX animals. CMA decreased total volumetric bone mineral density (vBMD) after 6 and 10 wk (week 10: intact normal +2.1 ± 0.9% vs. intact acidosis -3.6 ± 1.2%, P effect attributable to a decrease in cortical thickness and, thus, cortical bone mass (no significant effect on cancellous vBMD, week 10) attributed to an increase in endosteal bone resorption (nominally increased endosteal circumference). Trabecular bone volume (BV/TV) decreased significantly in both CMA groups at 6 and 10 wk, associated with a decrease in trabecular number. CMA significantly decreased muscle cross-sectional area in the proximal hindlimb at 6 and 10 wk. In conclusion, chronic metabolic acidosis induces a large decrease in cortical bone mass (a prime determinant of bone fragility) in intact and OVX rats and impairs bone microarchitecture characterized by a decrease in trabecular number. PMID:24352505

  10. PTH (1-84) Replacement Therapy in Hypoparathyroidism: Effects on bone metabolism and structure

    DEFF Research Database (Denmark)

    Sikjær, Tanja Tvistholm; Rejnmark, Lars; Tietze, Anna;

    Conventional treatment of hypoparathyroidism (hypoPT) with calcium supplements and active vitamin D analogues causes reduced bone turnover and over-mineralized bone. We studied 62 patients with known hypoPT randomized into 2 groups of treatment with either PTH (1–84) 100 µg/d s.c. or placebo...... bone tissue density (parchitecture from a rod-like to a more plate like structure. The changes in Tb.Th* and CD can be explained by the intratrabecular...

  11. PTH (1-84) Replacement Therapy in Hypoparathyroidism: Effects on bone metabolism and structure

    DEFF Research Database (Denmark)

    Sikjær, Tanja Tvistholm; Rejnmark, Lars; Tietze, Anna;

    2011-01-01

    Conventional treatment of hypoparathyroidism (hypoPT) with calcium supplements and active vitamin D analogues causes reduced bone turnover and over-mineralized bone. We studied 62 patients with known hypoPT randomized into 2 groups of treatment with either PTH (1–84) 100 µg/d s.c. or placebo...... bone tissue density (parchitecture from a rod-like to a more plate like structure. The changes in Tb.Th* and CD can be explained by the intratrabecular...

  12. [Bone diseases].

    Science.gov (United States)

    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. PMID:26946704

  13. The total real capital structure analysis in the profits mass relevant for turnover

    OpenAIRE

    CONSTANTIN CĂRUNTU; LOREDANA MIHAELA LĂPĂDUŞI

    2009-01-01

    The mechanism operator of total actual capital on profit afferent turnover in the synthesizer manner is an important tool in assessing the economic and financial performance of the company both internally and in the diagnostic tests performed outside. Addressed the overall level of business, real capital - fixed and circulating - appears as part of operating capital; with all other forms of total capital operated in the frame of business activity, actual capital is involved in a specific circ...

  14. Hibernation, stress, intestinal functions, and catecholoamine turnover rate in hamsters and gerbils

    Science.gov (United States)

    Musacchia, X. J.

    1973-01-01

    Bioenergetic studies on hamsters during depressed metabolic states are reported. External support of blood glucose extended the survival times of hibernating animals. Radioresistance increased in hibernating as well as in hypothermic hamsters. Marked changes in hamster catecholamine turnover rates were observed during acclimatization to high temperature stress. High radioresistance levels of the gerbil gastrointestinal system were attributed in part to the ability of the gut to maintain functional integrity.

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

    Energy Technology Data Exchange (ETDEWEB)

    Castaneda, S [Universidad Autonoma, Rheumatology Department, Hospital de la Princesa, Madrid (Spain); Largo, R.; Marcos, M.E.; Herrero-Beaumont, G. [Universidad Autonoma, Inflammation Research Unit, Rheumatology Department, Fundacion Jimenez Diaz, Madrid (Spain); Calvo, E. [Universidad Autonoma, Inflammation Research Unit, Rheumatology Department, Fundacion Jimenez Diaz, Madrid (Spain); Universidad Autonoma, Department of Orthopaedic Surgery, Fundacion Jimenez Diaz, Madrid (Spain); Rodriguez-Salvanes, F. [Universidad Autonoma, Clinical Epidemiology Unit, Hospital de la Princesa, Madrid (Spain); Diaz-Curiel, M. [Universidad Autonoma, Department of Internal Medicine, Fundacion Jimenez Diaz, Madrid (Spain)

    2006-01-01

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

  16. Bone biosensors: knowing the present and predicting the future

    Science.gov (United States)

    Khashayar, Patricia; Amoabediny, Ghassem; Larijani, Bagher; Vanfleteren, Jan

    2016-02-01

    Bone is an active organ with the capacity of continuous remodeling throughout adult life. In view of the fact that the current gold standard to assess bone remodeling, bone mineral density, suffers from certain limitations, newer techniques are being developed. Currently enzyme-linked immunosorbent assay is commonly used to assess bone turnover markers; the technique, however, is expensive, time consuming and needs trained personnel. Thus, there is a growing demand to fabricate different types of biosensors to provide low cost miniaturized platforms to assess the bone remodeling process more accurately. This review focuses on the latest advancements in the field of bone biosensing technologies. Its results might help provide possible solutions for translation of this technology for point-of-care diagnostic applications.

  17. Re-Examining the Relationship between Age and Voluntary Turnover

    Science.gov (United States)

    Ng, Thomas W. H.; Feldman, Daniel C.

    2009-01-01

    In their quantitative review of the literature, Healy, Lehman, and McDaniel [Healy, M. C., Lehman, M., & McDaniel, M. A. (1995). Age and voluntary turnover: A quantitative review. "Personnel Psychology, 48", 335-345] concluded that age is only weakly related to voluntary turnover (average r = -0.08). However, with the significant changes in…

  18. Estimating Cause: Teacher Turnover and School Effectiveness in Michigan

    Science.gov (United States)

    Keesler, Venessa; Schneider, Barbara

    2010-01-01

    The purpose of this paper is investigate issues related to within-school teacher supply and school-specific teacher turnover within the state of Michigan using state administrative data on Michigan's teaching force. This paper 1) investigates the key predictors of teacher turnover and mobility, 2) develops a profile of schools that are likely to…

  19. Understanding the Impacts of Induction Programs on Beginning Teacher Turnover

    Science.gov (United States)

    Kang, Seok

    2010-01-01

    This study examines impacts of mentoring and induction activities on beginning teacher turnover using the School and Staffing Survey (SASS) of 1999-2000 and the Teacher Follow-up Survey (TFS) of 2000-2001. In order to improve understanding of the influence of induction programs on beginning teacher turnover, three models are developed to achieve…

  20. Estimating average cellular turnover from BrdU measurements

    NARCIS (Netherlands)

    Boer, R.J. de; Mohri, H.; Ho, D.D.; Perelson, A.S.

    2003-01-01

    Cellular turnover rates in the immune system can be determined by labelling dividing cells with 5-bromo- 29-deoxyuridine (BrdU) or deuterated glucose ( ²H-glucose). To estimate the turnover rate from such measurements one has to fit a particular mathematical model to the data. The biological assum

  1. Organisational commitment and turnover intentions in humanitarian organisations

    NARCIS (Netherlands)

    Wijnmaalen, Julia; Heyse, Liesbet; Voordijk, Hans

    2016-01-01

    Unwanted staff turnover is a prominent HRM problem in humanitarian organisations. In the profit sector, HRM tools such as pay, benefits, socialisation and training have proven to be effective in increasing organisational commitment and decreasing staff turnover. This study explores whether such tool

  2. Voluntary Turnover and Women Administrators in Higher Education

    Science.gov (United States)

    Jo, Victoria H.

    2008-01-01

    A salient characteristic about the U.S. workforce is the continual process of voluntary employee turnover, which can be problematic for employers who invest a substantial amount of time and money in recruiting and training employees. This paper discusses the effects of workplace policies and practices on the voluntary turnover of women…

  3. Performance and turnover intentions: a social exchange perspective

    NARCIS (Netherlands)

    M. Biron; C. Boon

    2013-01-01

    Purpose - Prior research has yielded mixed results regarding the relationship between performance and turnover intentions. Drawing from social exchange theory, the purpose of this paper is to propose that the performance-turnover intentions association may be contingent upon individuals' exchange re

  4. PERAN STRES KERJA DAN KEPUASAN KERJA UNTUK MENGURANGI TURNOVER INTENTION

    OpenAIRE

    Syarifah Nazenin; Palupiningdyah Palupiningdyah

    2014-01-01

    Tujuan penelitian ini untuk menguji pengaruh variabel stres kerja dan kepuasan kerja pada turnover intention karyawan tetap bagian produksi. Sampel penelitian ini adalah 86 responden, menggunakan metode Slovin dengan teknik probability sampling dengan jenis proportionate random sampling. Berdasarkan hasil penelitian, menunjukkan bahwa stres kerja berpengaruh positif signifikan pada turnover intention. Kemudian, kepuasan kerja berpengaruh negatif signifikan. Penelitian ini menyimpulkan, bahwa ...

  5. The Link between Training Satisfaction, Work Engagement and Turnover Intention

    Science.gov (United States)

    Memon, Mumtaz Ali; Salleh, Rohani; Baharom, Mohamed Noor Rosli

    2016-01-01

    Purpose: The purpose of this paper is to examine the casual relationship between training satisfaction, work engagement (WE) and turnover intention and the mediating role of WE between training satisfaction and turnover intention. Design/methodology/approach: Data were collected from 409 oil and gas professionals using an email survey…

  6. Predicting Turnover: Validating the Intent to Leave Child Welfare Scale

    Science.gov (United States)

    Auerbach, Charles; Schudrich, Wendy Zeitlin; Lawrence, Catherine K.; Claiborne, Nancy; McGowan, Brenda G.

    2014-01-01

    A number of proxies have been used in child welfare workforce research to represent actual turnover; however, there have been no psychometric studies to validate a scale specifically designed for this purpose. The Intent to Leave Child Welfare Scale is a proxy for actual turnover that measures workers' intention to leave. This scale was…

  7. Investigating Occupational Commitment and Turnover Intention Relationship with Burnout Syndrome

    OpenAIRE

    Aydem Ciftcioglu

    2011-01-01

    This study investigates burnout components impact on accountant’s occupational commitment and occupational turnover intention interaction. The data used in this study was taken from randomly selected 162 accountants who are the members of Istanbul Chambers of Certified Public Accountants (ICCPA). The results reveal that only emotional exhaustion component of burnout has partial mediating effect between affective occupational commitment and occupational turnover intention.

  8. Blueberry consumption prevents loss of collagen in bone matrix and inhibits senescence pathways in osteoblastic cells

    OpenAIRE

    Zhang, Jian; Lazarenko, Oxana P.; Blackburn, Michael L.; Badger, Thomas M.; Ronis, Martin J. J.; Chen, Jin-Ran

    2012-01-01

    Ovariectomy (OVX)-induced bone loss has been linked to increased bone turnover and higher bone matrix collagen degradation as the result of osteoclast activation. However, the role of degraded collagen matrix in the fate of resident bone-forming cells is unclear. In this report, we show that OVX-induced bone loss is associated with profound decreases in collagen 1 and Sirt1. This was accompanied by increases in expression and activity of the senescence marker collagenase and expression of p16...

  9. [Connective tissue in non-union and pseudarthrosis of long bones. Part I: Capsule of false joints in dogs (author's transl)].

    Science.gov (United States)

    Rohe, K; Bierther, M; Becker, W; Sarvestani, M

    1980-12-01

    Animal experiments were carried out on 28 dogs which underwent osteotomy of the femur without postoperative fixation. For systematic light- and transmission electron microscopy tissue from this area of 7 dogs was prepared. Result was a functional morphology of connective tissue. Instability of bone fragments is regarded as the most important factor in pathogenesis of pseudarthrosis. Pathologic mobility in the osteotomy area caused specific altered differentiation of local connective tissue cells, leading to a joint capsule-like formation of connective tissue. "Lining cells" to the pseudarthrotic cavity are fibroblasts and histiocyts, comparable to the "lining cells" of normal stratum synoviale. These cells are surrounded by some collagenous fibres and large amounts of amorphous ground substances. They derive means of numerous transitional forms. The capsule-like tissue formation aside the pseudarthrotic cavity is comparable to stratum synoviale of normal joints. In some of these capsule-like areas there are degenerative alterations similar to those of joint capsules in osteoarthritis. PMID:7222951

  10. Accelerated extracellular matrix turnover during exacerbations of COPD

    DEFF Research Database (Denmark)

    Sand, Jannie M B; Knox, Alan J; Lange, Peter;

    2015-01-01

    BACKGROUND: Exacerbations of chronic obstructive pulmonary disease (COPD) contribute significantly to disease progression. However, the effect on tissue structure and turnover is not well described. There is an urgent clinical need for biomarkers of disease activity associated with disease...... progression. Extracellular matrix (ECM) turnover reflects activity in tissues and consequently assessment of ECM turnover may serve as biomarkers of disease activity. We hypothesized that the turnover of lung ECM proteins were altered during exacerbations of COPD. METHODS: 69 patients with COPD hospitalised...... of circulating fragments of structural proteins, which may serve as markers of disease activity. This suggests that patients with COPD have accelerated ECM turnover during exacerbations which may be related to disease progression....

  11. Pitfalls in quantifying species turnover: the residency effect

    Directory of Open Access Journals (Sweden)

    Kevin Chase Burns

    2014-03-01

    Full Text Available The composition of ecological communities changes continuously through time and space. Understanding this turnover in species composition is a central goal in biogeography, but quantifying species turnover can be problematic. Here, I describe an underappreciated source of bias in quantifying species turnover, namely ‘the residency effect’, which occurs when the contiguous distributions of species across sampling domains are small relative to census intervals. I present the results of a simulation model that illustrates the problem theoretically and then I demonstrate the problem empirically using a long-term dataset of plant species turnover on islands. Results from both exercises indicate that empirical estimates of species turnover may be susceptible to significant observer bias, which may potentially cloud a better understanding of how the composition of ecological communities changes through time.

  12. Joint prosthesis and method of bone fixation

    OpenAIRE

    Oosterom, R; Pijl, A J; Bersee, H.E.N.; Van der Helm, F.C.; Herder, J. L.

    2006-01-01

    The invention relates to a joint prosthesis (10), for example, a knee joint or shoulder joint prosthesis comprising a first, socket-holding prosthesis part (11) for attachment to a first bone (12) and a second, ball-holding prosthesis part (13) for attachment to a second bone (14) that intermates with the first prosthesis part, wherein the first bone and the second bone are situated at either side of a joint, and wherein the ball (2) of the second prosthesis part is rotatably received in the ...

  13. Bone loss in women with type 1 diabetes

    DEFF Research Database (Denmark)

    tanderup joergensen, maj-britt; christensen, jesper olund; Svendsen, Ole Lander

    2015-01-01

    Background: Although osteoporosis has been investigated and debated in the diabetic population over the past decades, very little is known about the spontaneous changes in bone mineral density (BMD) and biochemical markers of bone turnover in pre- and postmenopausal type 1 diabetic (T1DM) women...... over time. Aim: To measure spontaneous changes in BMD and biochemical markers of bone turnover in pre- and postmenopausal T1DM women. Subjects: 53 T1DM women (31 premenopausal and 22 postmenopausal) from the outpatient clinic were enrolled in the study in 1993 and 35 (22 premenopausal, 13...... postmenopausal) were reexamined in 1997. Method: BMD was measured at femoral neck (f.n.), spine (L2 - L4), total body and forearm with DXA or SXA in 53 T1DM women. 4 years later a re-scan was carried out on 35 T1DM. Results: In premenopausal subjects a yearly decrease less than 1% at f.n., spine, forearm...

  14. Bone densitometry

    DEFF Research Database (Denmark)

    Ravn, Pernille; Alexandersen, P; Møllgaard, A

    1999-01-01

    The bisphosphonates have been introduced as alternatives to hormone replacement therapy (HRT) for the treatment and prevention of postmenopausal osteoporosis. The expected increasing application in at clinical practice demands cost-effective and easily handled methods to monitor the effect on bone....... The weak response at the distal forearm during antiresorptive treatment has restricted the use of bone densitometry at this region. We describe a new model for bone densitometry at the distal forearm, by which the response obtained is comparable to the response in other regions where bone densitometry...... is much more expensive and technically complicated. By computerized iteration of single X-ray absorptiometry forearm scans we defined a region with 65% trabecular bone. The region was analyzed in randomized, double-masked, placebo- controlled trials: a 2-year trial with alendronate (n = 69), a 1-year...

  15. Does a Corresponding Set of Variables for Explaining Voluntary Organizational Turnover Transfer to Explaining Voluntary Occupational Turnover?

    Science.gov (United States)

    Blau, Gary

    2007-01-01

    This study proposed and tested corresponding sets of variables for explaining voluntary organizational versus occupational turnover for a sample of medical technologists. This study is believed to be the first test of the Rhodes and Doering (1983) occupational change model using occupational turnover data. Results showed that corresponding job…

  16. Effects of Gastric Bypass and Gastric Banding on Bone Remodeling in Obese Patients with Type 2 Diabetes

    DEFF Research Database (Denmark)

    Yu, Elaine W; Wewalka, Marlene; Ding, Su-Ann;

    2016-01-01

    CONTEXT: Roux-en-Y gastric bypass (RYGB) leads to high-turnover bone loss, but little is known about skeletal effects of laparoscopic adjustable gastric banding (LAGB) or mechanisms underlying bone loss after bariatric surgery. OBJECTIVE: To evaluate effects of RYGB and LAGB on fasting...

  17. Staff turnover in statewide implementation of ACT: relationship with ACT fidelity and other team characteristics

    OpenAIRE

    Rollins, Angela L.; Salyers, Michelle P.; Tsai, Jack; Lydick, Jennifer M.

    2010-01-01

    Staff turnover on assertive community treatment (ACT) teams is a poorly understood phenomenon. This study examined annual turnover and fidelity data collected in a statewide implementation of ACT over a 5-year period. Mean annual staff turnover across all observations was 30.0%. Turnover was negatively correlated with overall fidelity at Year 1 and 3. The team approach fidelity item was negatively correlated with staff turnover at Year 3. For 13 teams with 3 years of follow-up data, turnover ...

  18. FRACTURE NASAL BONES

    Directory of Open Access Journals (Sweden)

    Balasubramanian Thaigarajan

    2013-03-01

    Full Text Available Nose is the most prominent part of the face, hence it is likely to be the most common structure to be injured in the face. Although fractures involving the nasal bones are very common, it is often ignored by the patient. Patients with fractures of nasal bone will have deformity, tenderness, haemorrhage, edema, ecchymosis, instability, and crepitation. These features may be present in varying combinations. This article discusses the pathophysiology of these fractures, role of radiography and ultrasound in their diagnosis and their management.

  19. Bone Adaptation and Regeneration - New Developments

    Science.gov (United States)

    Klein-Nulend, Jenneke; Bacabac, Rommel Gaud

    Bone is a dynamic tissue that is constantly renewed and adapts to its local loading environment. Mechanical loading results in adaptive changes in bone size and shape that strengthen bone structure. The mechanisms for adaptation involve a multistep process called mechanotransduction, which is the ability of resident bone cells to perceive and translate mechanical energy into a cascade of structural and biochemical changes within the cells. The transduction of a mechanical signal to a biochemical response involves pathways within the cell membrane and cytoskeleton of the osteocytes, the professional mechansensor cells of bone. During the last decade the role of mechanosensitive osteocytes in bone metabolism and turnover, and the lacuno-canalicular porosity as the structure that mediates mechanosensing, is likely to reveal a new paradigm for understanding the bone formation response to mechanical loading, and the bone resorption response to disuse. Strain-derived fluid flow of interstitial fluid through the lacuno-canalicular porosity seems to mechanically activate the osteocytes, as well as ensures transport of cell signaling molecules, nutrients and waste products. Cell-cell signaling from the osteocyte sensor cells to the effector cells (osteoblasts or osteoclasts), and the effector cell response - either bone formation or resorption, allow an explanation of local bone gain and loss as well as remodeling in response to fatigue damage as processes supervised by mechanosensitive osteocytes. The osteogenic activity of cultured bone cells has been quantitatively correlated with varying stress stimulations highlighting the importance of the rate of loading. Theoretically a possible mechanism for the stress response by osteocytes is due to strain amplification at the pericellular matrix. Single cell studies on molecular responses of osteocytes provide insight on local architectural alignment in bone during remodeling. Alignment seems to occur as a result of the

  20. Multiple melanocortin receptors are expressed in bone cells

    Science.gov (United States)

    Zhong, Qing; Sridhar, Supriya; Ruan, Ling; Ding, Ke-Hong; Xie, Ding; Insogna, Karl; Kang, Baolin; Xu, Jianrui; Bollag, Roni J.; Isales, Carlos M.

    2005-01-01

    Melanocortin receptors belong to the seven transmembrane domain, G-protein coupled family of receptors. There are five members of this receptor family labeled MC1R-MC5R. These receptors are activated by fragments derived from a larger molecule, proopiomelanocortin (POMC) and include ACTH, alpha beta and gamma-MSH and beta-endorphin. Because of in vitro and in vivo data suggesting direct effects of these POMC molecules on bone and bone turnover, we examined bone and bone derived cells for the presence of the various members of the melanocortin receptor family. We report that the five known melanocortin receptors are expressed to varying degrees in osteoblast-like and osteoclastic cells. POMC fragments increased proliferation and expression of a variety of genes in osteoblastic cells. Furthermore, POMC mRNA was detected in osteoclastic cells. These data demonstrate that POMC-derived peptide hormones acting through high affinity melanocortin receptors have specific effects on bone cells. Thus, in addition to the indirect effects of POMC-derived hormones on bone turnover through their modulation of steroid hormone secretion, POMC fragments may have direct and specific effects on bone cell subpopulations.

  1. 液压自动翻转机的设计%Design of a Hydraulic Turnover Machine

    Institute of Scientific and Technical Information of China (English)

    夏永胜; 童竹杳

    2014-01-01

    为实现大型变速箱的翻转,提高生产效率,降低劳动强度,设计了一种液压自动翻转机。主要从机械结构与液压系统等方面对设计过程进行了阐述,并对某些重要零件进行了应力分析。经实际应用,该翻转机可以用于大型变速箱的翻转功能。%To realize the turnover of large gearboxes, improve the production efficiency and reduce the labor intensi-ty, so a hydraulic turnover machine was desiged in this paper. The design process of this new hydraulic turnover ma-chine was roundly introduced from the mechanical system to hydraulic system. And the forces of some important parts were also analyzed. Then practical application showed that this hydraulic turnover machine could satisfy the demands of the turnover with large gear boxes.

  2. Organizational culture, job satisfaction, and clinician turnover in primary care.

    Science.gov (United States)

    Hall, Charles B; Brazil, Kevin; Wakefield, Dorothy; Lerer, Trudy; Tennen, Howard

    2010-04-01

    The purpose of this study is to examine how organizational culture and job satisfaction affect clinician turnover in primary care pediatric practices. One hundred thirty clinicians from 36 primary care pediatric practices completed the Primary Care Organizational Questionnaire (PCOQ), which evaluates interactions among members of the practice and job-related attributes measuring 8 organizational factors, along with a separate 3-item instrument measuring job satisfaction. Random effects logistic models were used to assess the associations between job satisfaction, the organizational factors from the PCOQ, and clinician turnover over the subsequent year. All 8 measured organizational factors from the PCOQ, particularly perceived effectiveness, were associated with job satisfaction. Five of the 8 organizational factors were also associated with clinician turnover. The effects of the organizational factors on turnover were substantially reduced in a model that included job satisfaction; only 1 organizational factor, communication between clinicians and nonclinicians, remained significant (P = .05). This suggests that organizational culture affects subsequent clinician turnover primarily through its effect on job satisfaction. Organizational culture, in particular perceived effectiveness and communication, affects job satisfaction, which in turn affects clinician turnover in primary care pediatric practices. Strategies to improve job satisfaction through changes in organizational culture could potentially reduce clinician turnover. PMID:23804066

  3. Photosynthate consumption and carbon turnover in the rhizosphere depending on plant species and growth conditions

    International Nuclear Information System (INIS)

    The root tissue which can be isolated from soils represents only part of the total plant carbon incorporation. Between 20 and 40% of the photosynthetic production of plants is expended for root growth and root metabolism. This indicates a striking turnover of energy in the rhizosphere, because relatively litle root-derived organic matter remains there until harvest time. Plant species and variety, soil conditions and temperature were shown to be the most decisive factors governing the assimilate consumption of plant root systems. A special technique is described which enables to study how this extensive turnover affects the surrounding soil depending on its proximity to the roots. Plant-derived carbon can be detected up to 20mm away from the roots. A priming effect has been found on the decomposition of soil organic matter. This explains why, in spite of the rhizo-deposition mentioned, no net-accumulation of carbon in the rhizosphere has been found. (Author)

  4. Measurements of protein turnover in man with nitrogen-15

    International Nuclear Information System (INIS)

    Past and present methods of measuring total body protein turnover with 15N-labelled compounds are reviewed, and a short assessment made of results achieved. Protein turnover in man was first measured by Sprinson and Rittenberg (1949) using 15N glycine as tracer. The rate of turnover was calculated from the fraction of the dose excreted in urine in the days following a single oral dose of the isotope. In the following years a number of similar methods were devised but interest waned, perhaps because consistent changes in turnover rate under different conditions were not detected. A revival of interest came with the measurement of changes in protein turnover in malnourished and recovering children by Picou and Taylor-Roberts (1969). Nitrogen-15-glycine was infused and measurements were made of the abundance of 15N in urinary urea, which reached a plateau in about 24 hours. Turnover rates were calculated from the proportion of the infused dose excreted in urea after the plateau had been reached. This method has also been used successfully on adults when the isotope has been given as three-hourly oral doses. In adults, however, plateau labelling in urea is not usually reached for two days. In our laboratory the use of urinary ammonia, which reaches a plateau more quickly than urea, has been examined. In addition, comparisons have been made between constant infusion and single dose of isotope. Halliday and McKeran (1975) infused 15N-lysine and measured the 15N abundance in the free lysine of plasma, which reached a plateau in about 12 hours. Turnover in the whole body and turnover of muscle proteins and of plasma albumin were estimated separately. These methods of measuring protein turnover with 15N are described and results reviewed of the effects of food intake, nutritional status and age. (author)

  5. Stayers, Leavers, and Switchers Among Certified Nursing Assistants in Nursing Homes: A Longitudinal Investigation of Turnover Intent, Staff Retention, and Turnover

    OpenAIRE

    ROSEN, JULES; Stiehl, Emily M.; Mittal, Vikas; Leana, Carrie R.

    2011-01-01

    Purpose: Studies of certified nursing assistant (CNA) turnover in nursing homes are typically cross-sectional and include full-time and part-time workers. We conducted a longitudinal study to evaluate the job factors and work attitudes associated with just full-time staying or leaving. For those who did not stay, we assessed reasons for leaving and satisfaction following job transition. Design and Methods: A random sample of CNAs identified through the Pennsylvania Department of Health's CNA ...

  6. Case of femoral diaphyseal stress fracture after long-term risedronate administration diagnosed by iliac bone biopsy

    Directory of Open Access Journals (Sweden)

    Nagai T

    2013-04-01

    Full Text Available Takashi Nagai, Keizo Sakamoto, Koji Ishikawa, Emi Saito, Takuma Kuroda, Katsunori Inagaki Department of Orthopaedic Surgery, Showa University School of Medicine, Shinagwa-ku, Tokyo, Japan Abstract: Bisphosphonate excessively inhibits bone resorption and results in pathological fracture of the femur or ilium. The subject of this study was administered risedronate for 7 years; we suspected an easy fracture of the femoral diaphysis. In this study, we report the results of this patient's bone biopsy and bone morphometric analysis. A 76-year-old female patient presented with right femoral pain. Bone mineral density of the anteroposterior surface of the 2nd to 4th lumbar vertebrae (L2-L4 was decreased and levels of bone turnover markers were high. Therefore, we initiated treatment with risedronate. As she continued the medication, urinary levels of cross-linked N-terminal telopeptides of type I collagen and alkaline phosphatase (bone-type isozyme were found to be within the normal ranges. After 7 years of administration, the patient experienced pain when she put weight on the right femur and right femoral pain while walking. Plain radiographic examination revealed polypoid stress fracture-like lesions on the right femoral diaphysis and on the slightly distal-lateral cortical bone. Similar lesions were observed on magnetic resonance imaging and bone scintigraphy. We suspected severely suppressed bone turnover. Bone biopsy was obtained after labeling with tetracycline, and bone morphometric analysis was performed. On microscopic examination, slight double tetracycline labeling was observed. The trabeculae were narrow, and the numbers of osteoblasts and osteoclasts were decreased. Further, rates of bone calcification and bone formation were slow. Hence, we diagnosed fracture as a result of low turnover osteopathy. Risedronate was withdrawn, and Vitamin D3 was administered to improve the bone turnover. At 6 months, abnormal signals on magnetic resonance

  7. Does increased local bone resorption secondary to breast and prostate cancer result in increased cartilage degradation?

    International Nuclear Information System (INIS)

    Breast and prostate cancer patients often develop lesions of locally high bone turnover, when the primary tumor metastasizes to the bone causing an abnormal high bone resorption at this site. The objective of the present study was to determine whether local increased bone turnover in breast and prostate cancer patients is associated with an increase in cartilage degradation and to test in vitro whether osteoclasts or cathepsin K alone generate CTXII from human bone. The study included 132 breast and prostate cancer patient, where presence of bone metastases was graded according to the Soloway score. Total bone resorption (CTXItotal) and cartilage degradation (CTXII) were determined. Breast and prostate cancer patients with bone metastases revealed significant increased levels of CTXItotal at Soloway scores 1 and higher compared to patients without bone metastases (p < 0.001). CTXII was statistically elevated at score 3 and 4 (p < 0.01). CTXII/CTXItotal significantly decreased at score 3 and 4 (p < 0.001). Levels of CTXItotal, CTXII and CTXII/CTXItotal changed +900%, +130%, and -90%, respectively at Soloway score 4 compared to score 0. The in vitro experiments revealed that osteoclasts released CTXI fragments but not CTXII from bone specimens. The same was observed for cathepsin K. Data suggest that an uncoupling between bone resorption and cartilage degradation occurs in breast and lung cancer patient

  8. Bone mineral density and bone markers in patients with a recent low-energy fracture: effect of 1 y of treatment with calcium and vitamin D

    DEFF Research Database (Denmark)

    Hitz, Mette F; Jensen, Jens-Erik B; Eskildsen, Peter C

    2007-01-01

    BACKGROUND: Low-energy fractures of the hip, forearm, shoulder, and spine are known consequences of osteoporosis. OBJECTIVE: We evaluated the effect of 1 y of treatment with calcium and vitamin D on bone mineral density (BMD) and bone markers in patients with a recent low-energy fracture. DESIGN...... significantly related to physical performance. CONCLUSIONS: A 1-y intervention with calcium and vitamin D reduced bone turnover, significantly increased BMD in patients younger than 70 y, and decreased bone loss in older patients. The effect of treatment was related to physical performance....

  9. A simplified method for the clinical study of protein turnover

    International Nuclear Information System (INIS)

    The determination of turnover rate of serum albumin, or of other serum proteins, may be interesting for clinical purposes because the turnover rates may be changed as one of the consequences of renal, hepatic or gastro-intestinal diseases. Until now, is was not possible to use turnover methods routinely in the clinic, because daily sampling is too tedious for patients and hospital employees. A simplified method of sampling was introduced. This method was then evaluated in order to determine whether or not the results would be significant enough for clinical purposes. 1 tab

  10. The interpretation of results of protein turnover studies

    International Nuclear Information System (INIS)

    This interpretation of the protein turnover studies is made on the basis of modern knowledge of protein synthesis. A theory has been developed which gives a simple interpretation of protein turnover data. As, apparently, no disturbances leading to an endogenous hyper catabolism or hypo catabolism exist, altered protein turnover results with labelled albumin can only be interpreted as follows. Increased loss of protein takes place in the renal system or the intestinal tract. A decreased pool of building blocks are caused by gastro-intestinal diseases or hunger. Finally disturbances in the liver are caused by an acquired liver disease. 2 tabs

  11. Colloidal 234Th and the turnover of oceanic DOC

    International Nuclear Information System (INIS)

    234Th has been proposed to be a tracer for the labile, colloidal fraction of DOC in seawater. During the recent North Atlantic Bloom Experiment (NABE) the turnover of DOC was directly measured. 234Th and total suspended matter (Cp) were also measured by different research groups. Using the NABE 234Th data the authors have calculated the turnover rate of colloidal material using the Brownian Pumping model of Honeyman and Santschi and the 4-box particle cycling model of Moran and Buesseler. The rate constants for colloid cycling determined from the 234Th data agree well with the experimentally determined rate constants for turnover of DOC

  12. Turnover and employment in the German wind energy industry

    International Nuclear Information System (INIS)

    Results of the fast growing wind energy market in 1994 are the turnover reaching more than 800 million DM, and the number of employees to about 3,700. In 1995 the manufacturers expect to need less than 4 employees to build and to install 1 MW rated power and to decrease the ratio of manufacturer's turnover per installed power unit to about 1900 DM/kW. In spite of this development it is expected that the turnover and the number of employees will increase due to the still fast growing market. (orig.)

  13. Turnover Rate of Popularity Charts in Neutral Models

    CERN Document Server

    Evans, T S

    2011-01-01

    It has been shown recently that in many different cultural phenomena the turnover rate on the most popular artefacts in a population exhibit some regularities. A very simple expression for this turnover rate has been proposed by Bentley et al. and its validity in two simple models for copying and innovation is investigated in this paper. It is found that Bentley's formula is an approximation of the real behaviour of the turnover rate in the Wright-Fisher model, while it is not valid in the Moran model.

  14. Your Bones

    Science.gov (United States)

    ... a fall! If you play sports like football, soccer, lacrosse, or ice hockey, always wear all the ... to strengthen your bones is through exercise like running, jumping, dancing, and playing sports. Take these steps ...

  15. Hsp90 inhibition decreases mitochondrial protein turnover.

    Directory of Open Access Journals (Sweden)

    Daciana H Margineantu

    Full Text Available BACKGROUND: Cells treated with hsp90 inhibitors exhibit pleiotropic changes, including an expansion of the mitochondrial compartment, accompanied by mitochondrial fragmentation and condensed mitochondrial morphology, with ultimate compromise of mitochondrial integrity and apoptosis. FINDINGS: We identified several mitochondrial oxidative phosphorylation complex subunits, including several encoded by mtDNA, that are upregulated by hsp90 inhibitors, without corresponding changes in mRNA abundance. Post-transcriptional accumulation of mitochondrial proteins observed with hsp90 inhibitors is also seen in cells treated with proteasome inhibitors. Detailed studies of the OSCP subunit of mitochondrial F1F0-ATPase revealed the presence of mono- and polyubiquitinated OSCP in mitochondrial fractions. We demonstrate that processed OSCP undergoes retrotranslocation to a trypsin-sensitive form associated with the outer mitochondrial membrane. Inhibition of proteasome or hsp90 function results in accumulation of both correctly targeted and retrotranslocated mitochondrial OSCP. CONCLUSIONS: Cytosolic turnover of mitochondrial proteins demonstrates a novel connection between mitochondrial and cytosolic compartments through the ubiquitin-proteasome system. Analogous to defective protein folding in the endoplasmic reticulum, a mitochondrial unfolded protein response may play a role in the apoptotic effects of hsp90 and proteasome inhibitors.

  16. Multimodality Molecular Imaging of Cardiac Cell Transplantation: Part I. Reporter Gene Design, Characterization, and Optical in Vivo Imaging of Bone Marrow Stromal Cells after Myocardial Infarction.

    Science.gov (United States)

    Parashurama, Natesh; Ahn, Byeong-Cheol; Ziv, Keren; Ito, Ken; Paulmurugan, Ramasamy; Willmann, Jürgen K; Chung, Jaehoon; Ikeno, Fumiaki; Swanson, Julia C; Merk, Denis R; Lyons, Jennifer K; Yerushalmi, David; Teramoto, Tomohiko; Kosuge, Hisanori; Dao, Catherine N; Ray, Pritha; Patel, Manishkumar; Chang, Ya-Fang; Mahmoudi, Morteza; Cohen, Jeff Eric; Goldstone, Andrew Brooks; Habte, Frezghi; Bhaumik, Srabani; Yaghoubi, Shahriar; Robbins, Robert C; Dash, Rajesh; Yang, Phillip C; Brinton, Todd J; Yock, Paul G; McConnell, Michael V; Gambhir, Sanjiv S

    2016-09-01

    Purpose To use multimodality reporter-gene imaging to assess the serial survival of marrow stromal cells (MSC) after therapy for myocardial infarction (MI) and to determine if the requisite preclinical imaging end point was met prior to a follow-up large-animal MSC imaging study. Materials and Methods Animal studies were approved by the Institutional Administrative Panel on Laboratory Animal Care. Mice (n = 19) that had experienced MI were injected with bone marrow-derived MSC that expressed a multimodality triple fusion (TF) reporter gene. The TF reporter gene (fluc2-egfp-sr39ttk) consisted of a human promoter, ubiquitin, driving firefly luciferase 2 (fluc2), enhanced green fluorescent protein (egfp), and the sr39tk positron emission tomography reporter gene. Serial bioluminescence imaging of MSC-TF and ex vivo luciferase assays were performed. Correlations were analyzed with the Pearson product-moment correlation, and serial imaging results were analyzed with a mixed-effects regression model. Results Analysis of the MSC-TF after cardiac cell therapy showed significantly lower signal on days 8 and 14 than on day 2 (P = .011 and P = .001, respectively). MSC-TF with MI demonstrated significantly higher signal than MSC-TF without MI at days 4, 8, and 14 (P = .016). Ex vivo luciferase activity assay confirmed the presence of MSC-TF on days 8 and 14 after MI. Conclusion Multimodality reporter-gene imaging was successfully used to assess serial MSC survival after therapy for MI, and it was determined that the requisite preclinical imaging end point, 14 days of MSC survival, was met prior to a follow-up large-animal MSC study. (©) RSNA, 2016 Online supplemental material is available for this article. PMID:27308957

  17. INCIDENCE OF INTERPARIETAL (INCA BONES IN THE POPULATION OF ASSAM

    Directory of Open Access Journals (Sweden)

    Bijoy Kumar

    2015-07-01

    Full Text Available The occipital bone forms the region of the back of the head. It consists of three parts - the squamous part, the basilar part and the two condylar parts on either side of the foramen magnum. The squamous part of the occipital bone consists of two parts – the upper interparietal and the lower supraoccipital part. Usually the interparietal part fuses with the supraoccipital part but sometimes it may remain separated by a suture. Then it is called interparietal bone or Inca bone. AIM & OBJECTIVES: The aim of the present study is to find out the incidence of interparietal or Inca bones in this part of north east India as data regarding its incidence rate and number of fragments of Inca bones from Assam is still underreported. MATERIALS & METHOD: In the present study, a total of 126 dry adult skulls were examined to know the incidence of Inca bones. All the specimens were procured from various departments in Assam Medical College, Dibrugarh, Assam. They were first examined for presence or absence of Inca bones and then for number of fragments. RESULTS & OBSERVATIO NS: The incidence of Inca bone was found to be 1.58%. One skull presented with a single triangular Inca bone while another skull presented with two fragments of Inca bones. CONCLUSIONS: The knowledge regarding interparietal bones and that it may present with many fragments is certainly very useful for neurosurgeons, radiologists and anthropologists

  18. Plum and soy aglycon extracts superior at increasing bone calcium retention in ovariectomized Sprague Dawley rats.

    Science.gov (United States)

    Pawlowski, Jessica W; Martin, Berdine R; McCabe, George P; Ferruzzi, Mario G; Weaver, Connie M

    2014-07-01

    Plant-derived polyphenols have been shown to influence bone turnover and bone properties in the estrogen-depleted state. We used a crossover design in ovariectomized rats (n = 16 rats for each diet) to investigate the effect of supplementation of two doses each of blueberry, plum, grape, grape seed extract, and resveratrol on bone. We tested the aglycon and glucoside forms of genistein to quantify differences in efficacy on bone calcium retention. Rats were given an intravenous dose of ⁴⁵Ca to prelabel bone, and bone calcium retention was assessed by urinary excretion of ⁴⁵Ca:Ca ratio during an intervention period compared with nonintervention. Genistein aglycon increased bone calcium retention significantly (pcalcium retention by 20% (p=0.0153) and 14% (p=0.0012), respectively. Several polyphenolic-rich diets improved bone calcium retention.

  19. The Relation of Bone Turnover Markers to Estradiol, Lean Body Mass in Pubertal Girls around the Menarche%女性初潮前后骨代谢生化因子与雌激素、瘦体重相关分析

    Institute of Scientific and Technical Information of China (English)

    何淑敏; 赵仁清; 陈明

    2012-01-01

    Objective To investigate the changing characteristics of BAP (bone-specific alkaline phosphatase) , OC (osteocalcin) , and TRAP (tartrat-resistant acid phosphatase) and the related regulating factors in girls around the menarche. Methods One hundred and fifteen girls voluntarily participated in this study. Their body height (H) , weigh (W) , fat mass (FM) , lean mass(LM) , serum estradiol (E2) > testosterone (T) and sex hormone binding globulin (SHBG) as well as BAP, OC and TRAP were determined. Results Increased serum BAP and OC before menarche decreased at menarche, and decreased serum TRAP before menarche continued to decrease at menarche. H closely correlated with BAP 0 = 0.22, P = 0.001) , OC 0 = 0.21, P = 0.002) and TRAP 0 = 0.14, P = 0.04) , while serum E2, LM significantly associated with BAP (E2: r = 0.2, P = 0.003; LM: r = 0.15, P = 0.029) and OC (E2: r = 0.34, P< 0.0001; LM: r = 0.30, P < 0.0001) without significant correlation to TRAP. Conclusion It was suggested that level of bone metabolism around the menarche decreased, and growth of body height was associated with bonemetabolism, in which estradiol and mechanical strains were the two important regulating factors.%目的:探讨女性骨代谢生化因子骨钙素(OC)、骨碱性磷酸酶(BAP)和抗酒石酸酸性磷酸酶(TRAP)在初潮前后的变化特征及其相关影响因素.方法:以平均年龄(11.4±0.6)岁的115名小学女生为对象,测量其身高(H)、体重(W)、脂肪含量(FM)、瘦体重含量(LM),血清雌二醇(E2)、睾酮(T)、性激素结合蛋白(SHBG)及血清OC、BAP和TRAP.随访获得实验对象的初潮时间,以测量时相距初潮的时间作为自变量,拟合骨代谢生化因子及相关指标的回归曲线方程.采用偏相关方法检测骨代谢生化标志物与其影响因素之间的相关性.结果:初潮前呈上升趋势的OC、BAP在初潮时显著下降,而TRAP从初潮前至初潮一直下降.从初潮前至初潮,H与BAP (r=0.22,P=0.001)、OC (r=0

  20. Storage and turnover of organic matter in soil

    Energy Technology Data Exchange (ETDEWEB)

    Torn, M.S.; Swanston, C.W.; Castanha, C.; Trumbore, S.E.

    2008-07-15

    decomposition pathways and stabilization. These factors influence the stability of SOM in part by shaping its molecular characteristics, which play a fundamental role in nearly all processes governing SOM stability but are not the focus of this chapter. We review here the most important controls on the distribution and dynamics of SOM at plot to global scales, and methods used to study them. We also explore the concepts of controls, processes, and mechanisms, and how they operate across scales. The concept of SOM turnover, or mean residence time, is central to this chapter and so it is described in some detail. The Appendix details the use of radiocarbon ({sup 14}C), a powerful isotopic tool for studying SOM dynamics. Much of the material here was originally presented at a NATO Advanced Study Institute on 'Soils and Global Change: Carbon Cycle, Trace Gas Exchange and Hydrology', held June 16-27, 1997, at the Chateau de Bonas, France.

  1. Regulation of endoplasmic reticulum turnover by selective autophagy

    NARCIS (Netherlands)

    Khaminets, Aliaksandr; Heinrich, Theresa; Mari, Muriel; Grumati, Paolo; Huebner, Antje K.; Akutsu, Masato; Liebmann, Lutz; Stolz, Alexandra; Nietzsche, Sandor; Koch, Nicole; Mauthe, Mario; Katona, Istvan; Qualmann, Britta; Weis, Joachim; Reggiori, Fulvio; Kurth, Ingo; Huebner, Christian A.; Dikic, Ivan

    2015-01-01

    The endoplasmic reticulum (ER) is the largest intracellular endomembrane system, enabling protein and lipid synthesis, ion homeostasis, quality control of newly synthesized proteins and organelle communication(1). Constant ER turnover and modulation is needed to meet different cellular requirements

  2. Exposure to negative acts and risk of turnover

    DEFF Research Database (Denmark)

    Clausen, Thomas; Hansen, Jørgen V.; Høgh (Hogh), Annie;

    2016-01-01

    -year (instead of a 1-year) follow-up period the association between bullying and turnover remained statistically significant in office workers even after adjusting for depressive symptoms (OR 2.10, 95 % CI 1.17-3.76). We found no statistically significant associations between threats of violence......PURPOSE: To investigate whether self-reported exposure to negative acts in the workplace (bullying and threats of violence) predicted turnover in three occupational groups (human service and sales workers, office workers and manual workers). METHODS: Survey data on 2766 respondents were combined...... exposure to negative acts (bullying and threats of violence) and risk of turnover. When participants were stratified by occupational group and analyses were adjusted for age, gender, tenure and psychosocial working conditions, we found that exposure to bullying predicted risk of turnover in office workers...

  3. Wind energy industry in Germany. Turnover and employment

    International Nuclear Information System (INIS)

    As a consequence of the growing wind energy market in Germany the importance of the industry in this business are has grown. In 1994 the turnover will go beyond 500 million DM, and the number of employees will reach 2,900. The turnover and the number of employees are increasing in spite of the higher efficiency. In 1994 only 5 employees are needed by a manufacturer to install 1 MW rated power instead of 15 in 1989, and the ratio of installed power to manufacturer's turnover has risen from 0,25 W/DM in 1988 to 0,455 W/DM in 1994. On the other hand the turnover of the manufacturers per employee has increased from 80,000 DM in 1988 to 440,000 DM in 1994. Economic development has considerably been advanced by subsidies for the application of wind energy technology. (orig.)

  4. The Relationship Between Job Satisfaction and Turnover Intention

    Directory of Open Access Journals (Sweden)

    Ahmad Faisal Mahdi

    2012-01-01

    Full Text Available Problem statement: The objective of this study were to determine the effect of job satisfaction on turnover intentions among the employees in XYZ Sdn. Bhd, Malaysia. Approach: A total of 32 set of complete questionnaires gathered from executives and non-executives of a local printing company were involved in the study and 32 completed the questionnaires. Using structured questionnaires in a controlled environment, the results manage to extract both intrinsic and extrinsic job satisfaction that influences the turnover intention. Results: The statistical results obtained in this study showed that both forms of job satisfaction (intrinsic and extrinsic satisfaction have inverse relationship on employees’ turnover intentions. Conclusion: Eventhough Instrinsic Job Satisfaction have stronger influence on Turnover Intention. Existence of Extrinstic Job Satisfaction also must be consider in measuring the intention.

  5. Joint prosthesis and method of bone fixation

    NARCIS (Netherlands)

    Oosterom, R.; Van der Pijl, A.J; Bersee, H.E.N.; Van der Helm, F.C.; Herder, J.L

    2006-01-01

    The invention relates to a joint prosthesis (10), for example, a knee joint or shoulder joint prosthesis comprising a first, socket-holding prosthesis part (11) for attachment to a first bone (12) and a second, ball-holding prosthesis part (13) for attachment to a second bone (14) that intermates wi

  6. Tea and bone health: steps forward in translational nutrition.

    Science.gov (United States)

    Shen, Chwan-Li; Chyu, Ming-Chien; Wang, Jia-Sheng

    2013-12-01

    Osteoporosis is a major health problem in the aging population worldwide. Cross-sectional and retrospective evidence indicates that tea consumption may be a promising approach in mitigating bone loss and in reducing risk of osteoporotic fractures among older adults. Tea polyphenols enhance osteoblastogenesis and suppress osteoclastogenesis in vitro. Animal studies reveal that intake of tea polyphenols have pronounced positive effects on bone as shown by higher bone mass and trabecular bone volume, number, and thickness and lower trabecular separation via increasing bone formation and inhibition of bone resorption, resulting in greater bone strength. These osteoprotective effects appear to be mediated through antioxidant or antiinflammatory pathways along with their downstream signaling mechanisms. A short-term clinical trial of green tea polyphenols has translated the findings from ovariectomized animals to postmenopausal osteopenic women through evaluation of bioavailability, safety, bone turnover markers, muscle strength, and quality of life. For future studies, preclinical animal studies to optimize the dose of tea polyphenols for maximum osteoprotective efficacy and a follow-up short-term dose-response trial in postmenopausal osteopenic women are necessary to inform the design of randomized controlled studies in at-risk populations. Advanced imaging technology should also contribute to determining the effective dose of tea polyphenols in achieving better bone mass, microarchitecture integrity, and bone strength, which are critical steps for translating the putative benefit of tea consumption in osteoporosis management into clinical practice and dietary guidelines.

  7. Biochemical markers for assessment of calcium economy and bone metabolism: application in clinical trials from pharmaceutical agents to nutritional products

    OpenAIRE

    Bonjour, Jean-Philippe; Kohrt, Wendy; Levasseur, Régis; Warren, Michelle; Whiting, Susan; Kraenzlin, Marius

    2014-01-01

    Nutrition plays an important role in osteoporosis prevention and treatment. Substantial progress in both laboratory analyses and clinical use of biochemical markers has modified the strategy of anti-osteoporotic drug development. The present review examines the use of biochemical markers in clinical research aimed at characterising the influence of foods or nutrients on bone metabolism. The two types of markers are: (i) specific hormonal factors related to bone; and (ii) bone turnover markers...

  8. Stock-Based Compensation and Top Management Turnover

    OpenAIRE

    Hamid Mehran; David Yermack

    1996-01-01

    We test the hypothesis that corporate managers leave their jobs less often when they receive stock-based compensation. In a sample of CEOs from 452 large U.S. companies between 1984 and 1991, we find inverse associations between the probability of CEO turnover and the amount of stock option compensation in relation to cash pay. The association is even stronger when we exclude apparently involuntary CEO turnover. Our results suggest that stock-based compensation plays a significant role in hel...

  9. Employee turnover in a financial institution / van Zyl M.

    OpenAIRE

    Van Zyl, Marie-Antoinette

    2011-01-01

    With recognition of turnover as a financial issue increasing, companies are searching for strategies to confront the problem in ways that generate a good return on investment. Successfully managing turnover is a matter of understanding its costs, causes and cures. In service–oriented industries such as banking, people are considered among the most important assets of a firm. Forward–thinking banks are looking for ways to leverage people, along with processes and technology, to achieve their o...

  10. Turnover of nursing employees in a Gauteng hospital group

    OpenAIRE

    Japie Greyling; Karel Stanz

    2010-01-01

    Orientation: The South African nursing profession is in a crisis as professional nurses leave the country in search of lucrative work overseas.Research purpose: The purpose of this study was to investigate individual determinants of voluntary turnover to identify a risk-group profile.Motivation for the study: Nursing employers should have a clearer understanding of the dynamics around nurses’ turnover behaviour and embark on strategies to retain their talent.Research design, approach and meth...

  11. Kramers Turnover Theory for a Triple Well Potential

    International Nuclear Information System (INIS)

    Kramers turnover theory is solved for a particle in a symmetric triple well potential for temperatures above the crossover temperature between tunneling and activated barrier crossing. Comparison with the turnover theory for a double well potential shows that the presence of the intermediate well always leads to a decrease of the reaction rate. At most though, the rate is a factor of two smaller than in the case of a double well potential. (author)

  12. Excess turnover and employment growth: firm and match heterogeneity

    OpenAIRE

    Centeno, Mário; Machado, Carla; Novo, Álvaro A.

    2009-01-01

    Portuguese firms engage in intense reallocation, most employers simultaneously hire and separate from workers, resulting in a large heterogeneity of flows and excess turnover. Large and older firms have lower flows, but high excess turnover rates. In small firms, hires and separations move symmetrically during expansion and contraction periods, on the contrary, large firms adjust their employment levels by reducing entry and not by increasing separations. Most hires and separations are on fix...

  13. Investigating Occupational Commitment and Turnover Intention Relationship with Burnout Syndrome

    Directory of Open Access Journals (Sweden)

    Aydem Ciftcioglu

    2011-07-01

    Full Text Available This study investigates burnout components impact on accountant’s occupational commitment and occupational turnover intention interaction. The data used in this study was taken from randomly selected 162 accountants who are the members of Istanbul Chambers of Certified Public Accountants (ICCPA. The results reveal that only emotional exhaustion component of burnout has partial mediating effect between affective occupational commitment and occupational turnover intention.

  14. Bone marrow transplant

    Science.gov (United States)

    Transplant - bone marrow; Stem cell transplant; Hematopoietic stem cell transplant; Reduced intensity nonmyeloablative transplant; Mini transplant; Allogenic bone marrow transplant; Autologous bone marrow transplant; Umbilical ...

  15. The Cost of Teacher Turnover in Five School Districts: A Pilot Study

    Science.gov (United States)

    Barnes, Gary; Crowe, Edward: Schaefer, Benjamin

    2007-01-01

    In this paper, we report the results of a pilot study of the cost of teacher turnover in five school districts. We examine the rate of turnover, the relationship between turnover and teacher and school characteristics, and the costs associated with recruiting, hiring, and training replacement teachers. We find evidence that turnover costs,…

  16. Reviewing Employee Turnover: Focusing on Proximal Withdrawal States and an Expanded Criterion

    Science.gov (United States)

    Hom, Peter W.; Mitchell, Terence R.; Lee, Thomas W.; Griffeth, Rodger W.

    2012-01-01

    We reconceptualize employee turnover to promote researchers' understanding and prediction of why employees quit or stay in employing institutions. A literature review identifies shortcomings with prevailing turnover dimensions. In response, we expand the conceptual domain of the turnover criterion to include multiple types of turnover (notably,…

  17. Explaining the Gap in Charter and Traditional Public School Teacher Turnover Rates

    Science.gov (United States)

    Stuit, David A.; Smith, Thomas M.

    2012-01-01

    This study uses national survey data to examine why charter school teachers are more likely to turnover than their traditional public school counterparts. We test whether the turnover gap is explained by different distributions of factors that are empirically and theoretically linked to turnover risk. We find that the turnover rate of charter…

  18. Absence of correlation between rates of cell wall turnover and autolysis shown by Bacillus subtilis mutants.

    OpenAIRE

    Vitković, L; Cheung, H. Y.; Freese, E

    1984-01-01

    Bacillus subtilis mutants with reduced rates of cell wall autolysis reached a constant rate of wall turnover after a longer lag than the standard strain but eventually showed the same turnover rate. In reverse, a turnover-deficient mutant autolysed at a slightly higher rate than the standard strain. Consequently, there is no correlation between the rates of cell wall turnover and autolysis.

  19. Development, validation and characterization of a novel mouse model of Adynamic Bone Disease (ABD).

    Science.gov (United States)

    Ng, Adeline H; Willett, Thomas L; Alman, Benjamin A; Grynpas, Marc D

    2014-11-01

    The etiology of Adynamic Bone Disease (ABD) is poorly understood but the hallmark of ABD is a lack of bone turnover. ABD occurs in renal osteodystrophy (ROD) and is suspected to occur in elderly patients on long-term anti-resorptive therapy. A major clinical concern of ABD is diminished bone quality and an increased fracture risk. To our knowledge, experimental animal models for ABD other than ROD-ABD have not been developed or studied. The objectives of this study were to develop a mouse model of ABD without the complications of renal ablation, and to characterize changes in bone quality in ABD relative to controls. To re-create the adynamic bone condition, 4-month old female Col2.3Δtk mice were treated with ganciclovir to specifically ablate osteoblasts, and pamidronate was used to inhibit osteoclastic resorption. Four groups of animals were used to characterize bone quality in ABD: Normal bone controls, No Formation controls, No Resorption controls, and an Adynamic group. After a 6-week treatment period, the animals were sacrificed and the bones were harvested for analyses. Bone quality assessments were conducted using established techniques including bone histology, quantitative backscattered electron imaging (qBEI), dual energy X-ray absorptiometry (DXA), microcomputed tomography (microCT), and biomechanical testing. Histomorphometry confirmed osteoblast-related hallmarks of ABD in our mouse model. Bone formation was near complete suppression in the No Formation and Adynamic specimens. Inhibition of bone resorption in the Adynamic group was confirmed by tartrate-resistant acid phosphatase (TRAP) stain. Normal bone mineral density and architecture were maintained in the Adynamic group, whereas the No Formation group showed a reduction in bone mineral content and trabecular thickness relative to the Adynamic group. As expected, the No Formation group had a more hypomineralized profile and the Adynamic group had a higher mean mineralization profile that is

  20. Concentração industrial, fusões e turnover no setor supermercadista brasileiro Industrial concentration, mergers and turnover in Brazil's supermarket sector

    Directory of Open Access Journals (Sweden)

    Mônica Concha-Amin

    2006-04-01

    Full Text Available Este trabalho analisa a evolução da estrutura do setor supermercadista no Brasil, entre 1991 e 2002. Constatou-se que houve crescimento da concentração, impulsionado pela entrada de redes supermercadistas estrangeiras e por expressivo processo de fusões e aquisições, nos últimos anos da década de 1990. Em relação ao turnover, notou-se que este foi elevado, mas concentrou-se no grupo das empresas que não eram as maiores. Embora haja efeitos contraditórios, a mudança estrutural pode levar ao abuso de poder de mercado por parte dos supermercados, o que deve preocupar os órgãos de defesa da concorrência.This paper reports on an analysis of the structure of the supermarket sector in Brazil from 1991 to 2002. This analysis revealed a growth in market concentration driven by the entry of foreign retail companies and by a considerable increase in mergers and acquisitions in the late 1990s. The turnover was high, but did not, in general, involve the largest groups. Although there have been contradictory effects, the structural changes in Brazil's retail sector may lead to the abuse of market power on the part of the largest retailers, a possibility that should concern the antitrust authorities.

  1. Bone mineral content and bone metabolism in young adults with severe periodontitis

    DEFF Research Database (Denmark)

    Wowern von, N.; Westergaard, J.; Kollerup, G.

    2001-01-01

    Bone loss, bone markers, bone metabolism, bone mineral content, osteoporosis, severe periodontitis......Bone loss, bone markers, bone metabolism, bone mineral content, osteoporosis, severe periodontitis...

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

    Directory of Open Access Journals (Sweden)

    Wafa Bouleftour

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

  3. Mechanisms for the bone anabolic effect of parathyroid hormone treatment in humans

    DEFF Research Database (Denmark)

    Aslan, Derya; Dahl Andersen, Mille; Gede, Lene Bjerring;

    2012-01-01

    resorption during the first 6–18 months. This is due to the following: (1) PTH up-regulates c-fos expression in bone cells, (2) IGF is essential for PTH's anabolic effect, (3) bone lining cells are driven to differentiate into osteoblasts, (4) mesenchymal stem cells adhesion to bone surface is enhanced, (5...... of PTH given in intermittent treatment emerges through a complex network of pathways. In summary, the effects of PTH on bone turnover are dependent on the mode and dose of administration and studies investigating the mechanisms underlying this effect are reviewed in this article....

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

    DEFF Research Database (Denmark)

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

    2015-01-01

    -resolution peripheral quantitative computed tomography (HR-pQCT) of the ultradistal radius and tibia, and biochemical markers of bone turnover were performed in all participants. There were no significant differences in HR-pQCT parameters between MVD- and CoMVD- subjects. In contrast, MVD+ patients had larger total...

  5. [Bone transplant].

    Science.gov (United States)

    San Julián, M; Valentí, A

    2006-01-01

    We describe the methodology of the Bone and Soft Tissue Bank, from extraction and storage until use. Since the year 1986, with the creation of the Bone Bank in the University Clinic of Navarra, more than 3,000 grafts have been used for very different types of surgery. Bone grafts can be classified into cortical and spongy; the former are principally used in surgery to save tumour patients, in large post-traumatic reconstructions and in replacement surgery where there are massive bone defects and a structural support is required. The spongy grafts are the most used due to their numerous indications; they are especially useful in filling cavities that require a significant quantity of graft when the autograft is insufficient, or as a complement. They are also of special help in treating fractures when there is bone loss and in the treatment of delays in consolidation and pseudoarthrosis in little vascularized and atrophic zones. They are also used in prosthetic surgery against the presence of cavity type defects. Allografts of soft tissues are specially recognised in multiple ligament injuries that require reconstructions. Nowadays, the most utilised are those employed in surgery of the anterior cruciate ligament although they can be used for filling any ligament or tendon defect. The principal difficulties of the cortical allografts are in the consolidation of the ends with the bone itself and in tumour surgery, given that these are patients immunodepressed by the treatment, the incidence of infection is increased with respect to spongy grafts and soft tissues, which is irrelevant. In short, the increasingly widespread use of allografts is an essential therapeutic weapon in orthopaedic surgery and traumatology. It must be used by expert hands.

  6. [Bone transplant].

    Science.gov (United States)

    San Julián, M; Valentí, A

    2006-01-01

    We describe the methodology of the Bone and Soft Tissue Bank, from extraction and storage until use. Since the year 1986, with the creation of the Bone Bank in the University Clinic of Navarra, more than 3,000 grafts have been used for very different types of surgery. Bone grafts can be classified into cortical and spongy; the former are principally used in surgery to save tumour patients, in large post-traumatic reconstructions and in replacement surgery where there are massive bone defects and a structural support is required. The spongy grafts are the most used due to their numerous indications; they are especially useful in filling cavities that require a significant quantity of graft when the autograft is insufficient, or as a complement. They are also of special help in treating fractures when there is bone loss and in the treatment of delays in consolidation and pseudoarthrosis in little vascularized and atrophic zones. They are also used in prosthetic surgery against the presence of cavity type defects. Allografts of soft tissues are specially recognised in multiple ligament injuries that require reconstructions. Nowadays, the most utilised are those employed in surgery of the anterior cruciate ligament although they can be used for filling any ligament or tendon defect. The principal difficulties of the cortical allografts are in the consolidation of the ends with the bone itself and in tumour surgery, given that these are patients immunodepressed by the treatment, the incidence of infection is increased with respect to spongy grafts and soft tissues, which is irrelevant. In short, the increasingly widespread use of allografts is an essential therapeutic weapon in orthopaedic surgery and traumatology. It must be used by expert hands. PMID:16998521

  7. What Is Bone?

    Science.gov (United States)

    ... by your browser. Home Bone Basics What Is Bone? Publication available in: PDF (57 KB) Related Resources ... Men, and Osteoporosis Osteoporosis Prevention For Your Information Bone Remodeling Throughout life, bone is constantly renewed through ...

  8. Calcium and bones

    Science.gov (United States)

    Bone strength and calcium ... calcium (as well as phosphorus) to make healthy bones. Bones are the main storage site of calcium in ... your body does not absorb enough calcium, your bones can get weak or will not grow properly. ...

  9. Facts about Broken Bones

    Science.gov (United States)

    ... White House Lunch Recipes The Facts About Broken Bones KidsHealth > For Kids > The Facts About Broken Bones ... through the skin . continue What Happens When a Bone Breaks? It hurts to break a bone! It's ...

  10. Bone biopsy (image)

    Science.gov (United States)

    A bone biopsy is performed by making a small incision into the skin. A biopsy needle retrieves a sample of bone and it ... examination. The most common reasons for bone lesion biopsy are to distinguish between benign and malignant bone ...

  11. Bone lesion biopsy

    Science.gov (United States)

    Bone biopsy; Biopsy - bone ... is sent to a lab for examination. Bone biopsy may also be done under general anesthesia to ... remove the bone can be done if the biopsy exam shows that there is an abnormal growth ...

  12. Using Job Embeddedness Factors to Explain Voluntary Turnover in Five European Countries

    OpenAIRE

    Tanova, Cem

    2006-01-01

    This paper investigates actual voluntary turnover from the employee's perspective using a large European dataset integrating the available job factors related to job embeddedness and other variables that have been related to turnover in previous turnover models. The study shows that the traditional turnover model, where ease of movement and desire of movement are regarded as important predictors of turnover, receives support. However, the study also shows the job embeddedness factors play a k...

  13. Small parts: Crisóstomo Martínez (1638-1694), bone histology, and the visual making of body wholeness.

    Science.gov (United States)

    Valverde, Nuria

    2009-09-01

    The Valencian engraver Crisóstomo Martínez (ca. 1638-1694) arrived in Paris in July 1687, commissioned to create an anatomical atlas. Impressed by Govard Bidloo's Anatomia humani corporis (1685), Martínez decided to make a comparable work on osteology. His unpublished atlas of anatomy was exceptional in its choice of topic, its quality, and its overall visual approach. Martínez's work revolves around the dissolving effects of microscopic study on the traditional understanding of the connections between parts and whole. Underlying his investigation into the most effective composition of an anatomical atlas was the idea of the self-organizing and complex nature of the body as itself a composition, an idea rooted in the way observation and judgment, the seen and the unseen, and notions about collections and communities were connected in the vanitas culture. This essay explores the links between Martínez's work and the cultures of a time in which observation and interpretation of the processes of death, decay, and fragmentation played a primary role in defining a common human nature around which notions of destiny could be articulated.

  14. Build Up Your Bones! | NIH MedlinePlus the Magazine

    Science.gov (United States)

    ... special needs of people with osteoporosis. A Complete Osteoporosis Program Remember, exercise is only one part of an osteoporosis prevention ... your bones strong. Bone Mass Through the Lifespan: Exercise Helps Prevent Osteoporosis Illustration: Krames Winter 2011 Issue: Volume 5 Number ...

  15. The 18 kDa translocator protein (peripheral benzodiazepine receptor expression in the bone of normal, osteoprotegerin or low calcium diet treated mice.

    Directory of Open Access Journals (Sweden)

    Winnie Wai-Ying Kam

    Full Text Available The presence of the translocator protein (TSPO, previously named as the mitochondrial or peripheral benzodiazepine receptor, in bone cells was studied in vitro and in situ using RT-qPCR, and receptor autoradiography using the selective TSPO ligand PK11195.In vitro, the TSPO is highly expressed in osteoblastic and osteoclastic cells.In situ, constitutive expression of TSPO is found in bone marrow and trabecular bone, e.g., spongiosa. Mice with a reduction of bone turnover induced by a 4-day treatment of osteoprotegerin reduces [(3H]PK11195 binding in the spongiosa (320±128 Bq x mg(-1, 499±106 Bq x mg(-1 in saline-treated controls. In contrast, mice with an increase in bone turnover caused by a 4-day low calcium diet increases [(3H]PK11195 binding in the spongiosa (615±90 Bq x mg(-1. Further, our study includes technical feasibility data on [(18F]fluoride microPET imaging of rodent bone with altered turnover. Despite [(18F]fluoride having high uptake, the in vivo signal differences were small. Using a phantom model, we describe the spillover effect and partial volume loss that affect the quantitative microPET imaging of the small bone structures in experimental mouse models. In summary, we demonstrate the expression of TSPO in small rodent bone tissues, including osteoblasts and osteoclasts. A trend increase in TSPO expression was observed in the spongiosa from low to high bone turnover conditions. However, despite the potential utility of TSPO expression as an in vivo biomarker of bone turnover in experimental rodent models, our small animal PET imaging data using [(18F]fluoride show that even under the condition of a good biological signal-to-noise ratio and high tracer uptake, the currently achievable instrument sensitivity and spatial resolution is unlikely to be sufficient to detect subtle differences in small structures, such as mouse bone.

  16. Bone graft revascularization strategies

    NARCIS (Netherlands)

    W.F. Willems

    2014-01-01

    Reconstruction of avascular necrotic bone by pedicled bone grafting is a well-known treatment with little basic research supporting its application. A new canine model was used to simulate carpal bone avascular necrosis. Pedicled bone grafting proved to increase bone remodeling and bone blood flow,

  17. Bone disease in calcium stone forming patients.

    Science.gov (United States)

    Heilberg, I P; Martini, L A; Szejnfeld, V L; Carvalho, A B; Draibe, S A; Ajzen, H; Ramos, O L; Schor, N

    1994-09-01

    The association between idiopathic hypercalciuria and osteopenia (OP) has been recently recognized. It is not established whether or not calcium intake plays a critical role in the loss of bone mass. Fifty-five calcium stone forming patients with either absorptive hypercalciuria (AH) or fasting hypercalciuria (FH), 29 males and 26 premenopausal females, were submitted to dual photon absorptiometry at lumbar spine. Calcium intake was assessed by a 72 hr dietary record. OP was detected in 20% (11/55) of patients, being more common among men, 9/26 (35%) than in women, 2/29 (7%), p < 0.05. Male FH patients presented lower mean bone mineral density (BMD) than sex, weight and age-matched control (1.058 +/- 0.18 vs 1.209 +/- 0.13 g/cm2, X +/- SD, p < 0.05). OP was more frequent in FH patients, 7/20 (35%) than in AH patients 4/35 (11%), albeit the difference was not statistically significant. There was no correlation between calcium intake and BMD measurement. Six osteopenic male FH patients were further submitted to histomorphometric evaluation with tetracycline double labeling. Bone volume was lower than the controls (13.2 +/- 3.0 vs 27.2 +/- 3.7%, p < 0.05). Osteoid surfaces were reduced, although not significantly (10.1 +/- 8.2% vs 15.9 +/- 6.7%). Eroded surfaces were markedly increased (23.9 +/- 13.4 vs 4.2 +/- 1.4%, p < 0.05). The bone formation rate was very low with a complete lack of tetracycline double labeling in 4 patients. These data suggest low bone volume, tendency to low bone formation, increased bone resorption and a severe mineralization defect, consistent with normal or low bone turnover osteoporosis. PMID:7994936

  18. Bone scintigraphy in psoriasis

    Energy Technology Data Exchange (ETDEWEB)

    Hahn, K.; Thiers, G.; Eissner, D.; Holzmann, H.

    1980-08-01

    Since 1973 bone scintigraphy using sup(99m)Tc-phosphate-complexes was carried out in 382 patients with psoriasis. For comparison with the results of nuclear medicine, roentgenologic and clinical findings a group af 121 patients with psoriasis aged between 11 and 74 years was compared to a group of 42 patients aged between 20 and 49 years without roentgenologic and clinical signs of psoriasis arthritis. We found by means of isotope investigation that an essentially greater part of the bones adjacent to the joints was involved than was expected according to X-ray and clinical findings. In addition, in 205 patients with psoriasis whole-body scintigraphy, using sup(99m)Tc-MDP, was carried out since 1977/78. In 17 patients we found an increased accumulation of activity in the region of extraarticular structures of the skull as well as of the skeletal thorax. According to these results we conclude that in addition to the clinically and roentgenologically defined psoriatic arthritis in patients with psoriasis an osteopathy may exist, which can only be demonstrated by skeletal scintigraphy and which is localized in bones adjacent to the joints but can also be demonstrated in the region of extraarticular bones.

  19. Compromised cortical bone compartment in type 2 diabetes mellitus patients with microvascular disease

    DEFF Research Database (Denmark)

    Shanbhogue, Vikram Vinod; Hansen, Stinus; Nielsen, Morten Frost Munk;

    2016-01-01

    OBJECTIVE AND DESIGN: Patients with type 2 diabetes mellitus (T2D) have an increased fracture risk despite a normal or elevated bone mineral density (BMD). The aim of this cross-sectional in vivo study was to assess parameters of peripheral bone microarchitecture, estimated bone strength and bone......-resolution peripheral quantitative tomography (HR-pQCT) was used to assess bone structure at the non-dominant distal radius and tibia. Estimated bone strength was calculated using finite element analysis. Biochemical markers of bone turnover were measured in all participants. RESULTS: After adjusting for BMI, MVD......+ patients displayed lower cortical volumetric BMD (P=0.02) and cortical thickness (P=0.02) and higher cortical porosity at the radius (P=0.02) and a trend towards higher cortical porosity at the tibia (P=0.07) compared to controls. HR-pQCT parameters did not differ between MVD- and control subjects...

  20. Akt1 in osteoblasts and osteoclasts controls bone remodeling.

    Directory of Open Access Journals (Sweden)

    Naohiro Kawamura

    Full Text Available Bone mass and turnover are maintained by the coordinated balance between bone formation by osteoblasts and bone resorption by osteoclasts, under regulation of many systemic and local factors. Phosphoinositide-dependent serine-threonine protein kinase Akt is one of the key players in the signaling of potent bone anabolic factors. This study initially showed that the disruption of Akt1, a major Akt in osteoblasts and osteoclasts, in mice led to low-turnover osteopenia through dysfunctions of both cells. Ex vivo cell culture analyses revealed that the osteoblast dysfunction was traced to the increased susceptibility to the mitochondria-dependent apoptosis and the decreased transcriptional activity of runt-related transcription factor 2 (Runx2, a master regulator of osteoblast differentiation. Notably, our findings revealed a novel role of Akt1/forkhead box class O (FoxO 3a/Bim axis in the apoptosis of osteoblasts: Akt1 phosphorylates the transcription factor FoxO3a to prevent its nuclear localization, leading to impaired transactivation of its target gene Bim which was also shown to be a potent proapoptotic molecule in osteoblasts. The osteoclast dysfunction was attributed to the cell autonomous defects of differentiation and survival in osteoclasts and the decreased expression of receptor activator of nuclear factor-kappaB ligand (RANKL, a major determinant of osteoclastogenesis, in osteoblasts. Akt1 was established as a crucial regulator of osteoblasts and osteoclasts by promoting their differentiation and survival to maintain bone mass and turnover. The molecular network found in this study will provide a basis for rational therapeutic targets for bone disorders.

  1. Employment and turnover in the transport and logistics sector in the STRING region

    DEFF Research Database (Denmark)

    Serin, Göran Folke; Holzweber, Markus

    This report is part of the project ‘Green STRING Transport corridor’. It is the second of two reports from Roskilde University department of ‘Communication, Business admini- stration and Information Technologies (CBIT). Povl A. Hansen wrote the first report: ‘The Green STRING Corridor and transpo...... conditions when analysing the possibilities of establishing a ‘Green Transport Corridor’. The analysis will take its point of departure in analysis of employment, turnover, firm structure and location within the freight transport and logistics sector in the STRING region....

  2. Study of treating tibial large bone defect with migration of lengthened bone segment in goats

    Institute of Scientific and Technical Information of China (English)

    YANG liu; LI Qi-hong; ZHOU Zhong-an; TAN Zu-jian; PENG Yi-liang

    2001-01-01

    To study the effects of migration of lengthened bone segment (MLBS) on the blood circulation and repair remodeling process at the ends of large bone defect of a long bone. Methods: A total of 18 adult goats were used and more than 35% of the original length of their left tibia was resected. Upper metaphysiotomy to lengthen upper part of the tibia was done and the lengthened bone segment was migrated to repair the large bone defect. The results were observed with X-ray films, Chinese-ink permeated transparent sections and histological study. Results: After MLBS, the defect ends of the tibia were supplied with abundant blood circulation which resulted in rapid and solid long bone healing. Conclusion: Repair of large bone defect of long bones with MLBS provides a new method for clinical practice.

  3. STROMAS: A Series of Microgravity Experiments on Bone Forming Cells

    Science.gov (United States)

    Yi, Liu; Massimilano, Monticone; Federico, Tortelli; Matalija, Pujic; Alessandra, Ruggiu; Ranieri, Cancedda

    2008-06-01

    We developed a novel 3D in vitro culture system by seeding cells onto porous bioceramics, mimicking the physiological niche of bone turn-over and enhancing cellular differentiation respective to conventional 2D Petri Dish cultures. Having overcome several technological difficulties, in a series of STROMA spaceflight experiments 3D cultures of bone marrow derived mesenchymal stem cells (BMSC) and co-cultures of osteoblasts and osteoclast precursors were maintained and conserved in automated bioreactors on orbit. Genechip analysis revealed an inhibition of cell proliferation in microgravity. Unexpectedly, genes related to various processes of neural development were significantly upregulated in microgravity, raising the question on the lineage restriction in BMSC.

  4. Birth weight and adult bone metabolism are unrelated

    DEFF Research Database (Denmark)

    Frost, Morten; Petersen, Inge Lund; Andersen, Thomas Levin;

    2013-01-01

    recruited from the Danish Twin Registry. Serum vitamin D (25OHD) and bone turnover markers (BTM) P1NP, 1CTP, and CTX were quantified. Femoral neck, total hip, lumbar spine, and whole body bone mineral density (FN-BMD, TH-BMD, LS-BMD, and WB-BMD) were measured using DXA. Twins were studied as single...... individuals using regression analyses with or without adjustment for height, weight, age, sex, and intra-pair correlation. Within-pair differences were assessed using Student's T-test and fixed-regression models. RESULTS: BW was not associated with BTMs, LS-, TH-, FN- or WB-BMD, but BW was associated with WB...

  5. Bone mineral density and changes in bone metabolism in patients with obstructive sleep apnea syndrome.

    Science.gov (United States)

    Terzi, Rabia; Yılmaz, Zahide

    2016-07-01

    The aim of this study was to evaluate the differences between patients with obstructive sleep apnea syndrome (OSAS) and phenotypically similar subjects without OSAS in terms of bone mineral density (BMD) and bone turnover markers. The study was conducted on 30 males diagnosed with OSAS and 20 healthy males. All subjects underwent polysomnographic testing. Calcium, phosphorus parathyroid hormone, thyroid stimulating hormone, bone-specific alkaline phosphatase, 25-hydroxyvitamin D3, osteocalcin, and beta-CrossLaps (β-CTx) were measured. BMD in the lumbar spine (L1-L4) and femoral neck was measured by dual energy X-ray absorptiometry. There was no statistically significant difference between the two groups in terms of demographic data with the exception of bone mass index and waist circumference. (p < 0.05). Analyses showed significantly lower BMD measurements in the femoral neck and T-scores in the femoral neck in patients diagnosed with OSAS. Serum β-CTx levels were found to be statistically significantly higher in the OSAS group (p = 0.017). In multivariate assessments performed for apnea/hypopnea index values, mean saturation O2 levels were found to be significantly associated with osteocalcin levels and neck BMD. OSAS patients might represent a risk group with respect to loss of BMD and bone resorption. It is important to evaluate bone loss in these patients. Further studies should be carried out on larger study populations to evaluate the effects of chronic hypoxia on BMD in detail. PMID:26204846

  6. New insights to the role of aryl hydrocarbon receptor in bone phenotype and in dioxin-induced modulation of bone microarchitecture and material properties

    International Nuclear Information System (INIS)

    Bone is a target for high affinity aryl hydrocarbon receptor (AHR) ligands, such as dioxins. Although bone morphology, mineral density and strength are sensitive endpoints of dioxin toxicity, less is known about effects on bone microarchitecture and material properties. This study characterizes TCDD-induced modulations of bone tissue, and the role of AHR in dioxin-induced bone toxicity and for normal bone phenotype. Six AHR-knockout (Ahr−/−) and wild-type (Ahr+/+) mice of both genders were exposed to TCDD weekly for 10 weeks, at a total dose of 200 μg/kg bw. Bones were examined with micro-computed tomography, nanoindentation and biomechanical testing. Serum levels of bone remodeling markers were analyzed, and the expression of genes related to osteogenic differentiation was profiled using PCR array. In Ahr+/+ mice, TCDD-exposure resulted in harder bone matrix, thinner and more porous cortical bone, and a more compact trabecular bone compartment. Bone remodeling markers and altered expression of a number of osteogenesis related genes indicated imbalanced bone remodeling. Untreated Ahr−/− mice displayed a slightly modified bone phenotype as compared with untreated Ahr+/+ mice, while TCDD exposure caused only a few changes in bones of Ahr−/− mice. Part of the effects of both TCDD-exposure and AHR-deficiency were gender dependent. In conclusion, exposure of adult mice to TCDD resulted in harder bone matrix, thinner cortical bone, mechanically weaker bones and most notably, increased trabecular bone volume fraction in Ahr+/+ mice. AHR is involved in bone development of a normal bone phenotype, and is crucial for manifestation of TCDD-induced bone alterations. - Highlights: • TCDD disrupts bone remodeling resulting in altered cortical and trabecular bone. • In trabecular bone an anabolic effect is observed. • Cortical bone is thinner, more porous, harder, stiffer and mechanically weaker. • AHR ablation results in increased trabecular bone and softer

  7. Targeting a novel bone degradation pathway in primary bone cancer by inactivation of the collagen receptor uPARAP/Endo180

    DEFF Research Database (Denmark)

    Engelholm, Lars H; Melander, Maria C; Hald, Andreas;

    2016-01-01

    In osteosarcoma, a primary mesenchymal bone cancer occurring predominantly in younger patients, invasive tumour growth leads to extensive bone destruction. This process is insufficiently understood, cannot be efficiently counteracted and calls for novel means of treatment. The endocytic collagen...... of degrading the protein component of surface-labelled bone slices in a process dependent on MMP activity and uPARAP/Endo180. Systemic treatment of the sarcoma-inoculated mice with a mouse monoclonal antibody that blocks murine uPARAP/Endo180 led to a strong reduction of bone destruction. Our findings identify...... receptor, uPARAP/Endo180, is expressed on various mesenchymal cell types and is involved in bone matrix turnover during normal bone growth. Human osteosarcoma specimens showed strong expression of this receptor on tumour cells, along with the collagenolytic metalloprotease, MT1-MMP. In advanced tumours...

  8. Stressful work, psychological job strain, and turnover: a 2-year prospective cohort study of truck drivers.

    Science.gov (United States)

    de Croon, Einar M; Sluiter, Judith K; Blonk, Roland W B; Broersen, Jake P J; Frings-Dresen, Monique H W

    2004-06-01

    Based on a model that combines existing organizational stress theory and job transition theory, this 2-year longitudinal study examined antecedents and consequences of turnover among Dutch truck drivers. For this purpose, self-reported data on stressful work (job demands and control), psychological strain (need for recovery after work and fatigue), and turnover were obtained from 820 drivers in 1998 and 2000. In agreement with the model, the results showed that strain mediates the influence of stressful work on voluntary turnover. Also in conformity with the model, job movement to any job outside the trucking industry (i.e., interoccupational turnover) resulted in a larger strain reduction as compared to job movement within the trucking industry (intraoccupational turnover). Finally, strain was found to stimulate interoccupational turnover more strongly than it stimulated intraoccupational turnover. These findings provide a thorough validation of existing turnover theory and give new insights into the turnover (decision) process. PMID:15161404

  9. Decay times in turnover statistics of single enzymes

    CERN Document Server

    Lindén, Martin

    2008-01-01

    The first passage times for enzymatic turnovers in non-equilibrium steady state display a statistical symmetry property related to non-equilibrium fluctuation theorems, that makes it possible to extract the chemical driving force from single molecule trajectories in non-equilibrium steady state. Below, we show that this system violates the general expectation that the number of decay constants needed to fit a first passage time distribution reflects the number of states in the escape problem. In fact, the structure of the kinetic mechanism makes half of the decay times vanish identically from the turnover time distribution. The terms that cancel out correspond to the eigenvalues of a certain sub-matrix of the master equation matrix for the first exit time problem. We discuss how these results make modeling and data analysis easier for such systems, and how the turnovers can be measured.

  10. Potential role of human visceral pleura in pleural fluid turnover

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ With continuing advanced research into pleural fluid turnover, the majority of scientists hold the view that pleural fluid is derived from the microvessels in parietal pleura and drained via parietal lymphatic vessels which empty into systemic veins. The lymphatic vessels that contribute to the pulmonary lymphatic circulation originate in the subpleural connective tissue, not directly from the visceral mesothelium.1 Therefore, according to the current point of view, pleural effusion absorption through the visceral pleural is normally negligible and visceral pleura, is not involved in the pleural fluid turnover.2 Our study explored the origins of pulmonary lymphatic tissues in humans and the possible effect of visceral pleural on pleural fluid turnover. We compared the incidence of pleural fluid between patients with left and right heart failure, and detected the origin and distribution of lymphatic tissues in pulmonary lymphangiopathy.

  11. Firm-level innovation activity, employee turnover and HRM practices

    DEFF Research Database (Denmark)

    Eriksson, Tor; Qin, Zhihua; Wang, Wenjing

    2014-01-01

    This paper examines the relationship between employee turnover, HRM practices and innovation in Chinese firms in five high technology sectors. We estimate hurdle negative binomial models for count data on survey data allowing for analyses of the extensive as well as intensive margins of firms......' innovation activities. Innovation is measured both by the number of ongoing projects and new commercialized products. The results show that higher R&D employee turnover is associated with a higher probability of being innovative, but decreases the intensity of innovation activities in innovating firms....... Innovating firms are more likely to have adopted high performance HRM practices, and the impact of employee turnover varies with the number of HRM practices implemented by the firm...

  12. Cogema in 1996: increasing turnover and stable net results

    International Nuclear Information System (INIS)

    This short article gives some financial informations about the Cogema group for 1996. The net result for 1996 reached 977 millions of French Francs (FF) with respect to 973 for the previous year. The turnover reached 34.427 billions of FF in 1996 and 30.611 in 1995, which represents a 12.5% growth. In the mining sector, the turnover has decreased to 2.853 billions of FF with respect to 3.238 in 1995. In the engineering and industry services sector the turnover of the overall companies, with the exception of Cogema, has considerably progressed (2.199 billions of FF in 1996, 1.738 in 1995). (J.S.)

  13. Estimation of Employee Turnover with Competing Risks Models

    Directory of Open Access Journals (Sweden)

    Grzenda Wioletta

    2015-12-01

    Full Text Available Employee turnover accompanies every business organization, regardless of the industry and size. Nowadays, many companies struggle with problems related to the lack of sufficient information about the nature of employee turnover processes. Therefore, comprehensive analysis of these processes is necessary. This article aims to examine the turnover of employees from a big manufacturing company using competing risks models with covariates and without covariates. This technique allows to incorporate the information about the type of employment contract termination. Moreover, Cox proportional hazard model enables the researcher to analyse simultaneously multiple factors that affect employment duration. One of the major observations is that employee remuneration level differentiates most strongly the risk of job resignation.

  14. Bone and mineral metabolism in adult celiac disease

    International Nuclear Information System (INIS)

    Bone mineral density (125I 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 significant 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

  15. The population model of bone remodelling employed the optimal control.

    Science.gov (United States)

    Moroz, Adam

    2012-11-01

    Several models have been developed in recent years which apply population dynamics methods to describe the mechanisms of bone remodelling. This study incorporates the population kinetics model of bone turnover (including the osteocyte loop regulation) with the optimal control technique. Model simulations have been performed with a wide range of rate parameters using the Monte Carlo method. The regression method has also been used to investigate the interdependence of the location of equilibrium and the characteristics of the equilibrium/relaxation time on the rate parameters employed. The dynamic optimal control outlook for the regulation of bone remodelling processes, in the context of the osteocyte-control population model, has been discussed. Optimisation criteria have been formulated from the perspective of the energetic and metabolic losses in the tissue, with respect to the performance of the bone multicellular unit.

  16. Bone and mineral metabolism in adult celiac disease

    Energy Technology Data Exchange (ETDEWEB)

    Caraceni, M.P.; Molteni, N.; Bardella, M.T.; Ortolani, S.; Nogara, A.; Bianchi, P.A.

    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 significant 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.

  17. Human turnover dynamics during sleep: statistical behavior and its modeling.

    Science.gov (United States)

    Yoneyama, Mitsuru; Okuma, Yasuyuki; Utsumi, Hiroya; Terashi, Hiroo; Mitoma, Hiroshi

    2014-03-01

    Turnover is a typical intermittent body movement while asleep. Exploring its behavior may provide insights into the mechanisms and management of sleep. However, little is understood about the dynamic nature of turnover in healthy humans and how it can be modified in disease. Here we present a detailed analysis of turnover signals that are collected by accelerometry from healthy elderly subjects and age-matched patients with neurodegenerative disorders such as Parkinson's disease. In healthy subjects, the time intervals between consecutive turnover events exhibit a well-separated bimodal distribution with one mode at ⩽10 s and the other at ⩾100 s, whereas such bimodality tends to disappear in neurodegenerative patients. The discovery of bimodality and fine temporal structures (⩽10 s) is a contribution that is not revealed by conventional sleep recordings with less time resolution (≈30 s). Moreover, we estimate the scaling exponent of the interval fluctuations, which also shows a clear difference between healthy subjects and patients. We incorporate these experimental results into a computational model of human decision making. A decision is to be made at each simulation step between two choices: to keep on sleeping or to make a turnover, the selection of which is determined dynamically by comparing a pair of random numbers assigned to each choice. This decision is weighted by a single parameter that reflects the depth of sleep. The resulting simulated behavior accurately replicates many aspects of observed turnover patterns, including the appearance or disappearance of bimodality and leads to several predictions, suggesting that the depth parameter may be useful as a quantitative measure for differentiating between normal and pathological sleep. These findings have significant clinical implications and may pave the way for the development of practical sleep assessment technologies.

  18. Human turnover dynamics during sleep: Statistical behavior and its modeling

    Science.gov (United States)

    Yoneyama, Mitsuru; Okuma, Yasuyuki; Utsumi, Hiroya; Terashi, Hiroo; Mitoma, Hiroshi

    2014-03-01

    Turnover is a typical intermittent body movement while asleep. Exploring its behavior may provide insights into the mechanisms and management of sleep. However, little is understood about the dynamic nature of turnover in healthy humans and how it can be modified in disease. Here we present a detailed analysis of turnover signals that are collected by accelerometry from healthy elderly subjects and age-matched patients with neurodegenerative disorders such as Parkinson's disease. In healthy subjects, the time intervals between consecutive turnover events exhibit a well-separated bimodal distribution with one mode at ⩽10 s and the other at ⩾100 s, whereas such bimodality tends to disappear in neurodegenerative patients. The discovery of bimodality and fine temporal structures (⩽10 s) is a contribution that is not revealed by conventional sleep recordings with less time resolution (≈30 s). Moreover, we estimate the scaling exponent of the interval fluctuations, which also shows a clear difference between healthy subjects and patients. We incorporate these experimental results into a computational model of human decision making. A decision is to be made at each simulation step between two choices: to keep on sleeping or to make a turnover, the selection of which is determined dynamically by comparing a pair of random numbers assigned to each choice. This decision is weighted by a single parameter that reflects the depth of sleep. The resulting simulated behavior accurately replicates many aspects of observed turnover patterns, including the appearance or disappearance of bimodality and leads to several predictions, suggesting that the depth parameter may be useful as a quantitative measure for differentiating between normal and pathological sleep. These findings have significant clinical implications and may pave the way for the development of practical sleep assessment technologies.

  19. Public schools’ characteristics and teacher turnover in Oman

    Directory of Open Access Journals (Sweden)

    Khairuddin Idris

    2013-10-01

    Full Text Available Teachers are the backbone of the educational systems and their turnover may threaten the whole educational system in any country. In Oman, teacher turnover is a neglected area of study and this article may help in shedding some light on teacher turnover phenomenon in Oman. The purpose of this study is to investigate the influence of school characteristics (e.g., school size, gender, time-shift, education type, and school location on the turnover intentions of teachers in public schools in Oman. Survey questionnaires were used to collect data from 214 public schools in Oman. 142 schools from all educational regions in Oman were participated in this study. Data analyses tools for this study were descriptive statistics such as mean and standard deviation, in addition to independents t-test and analysis of variance. The study revealed that teacher intentions to transfer to other schools are influenced by almost all the studied school characteristics. Policy makers and human resource recruiters in Ministry of Education should be aware of teachers’ preferences for certain schools to avoid teachers’ shortage in non-preferred schools. Further studies about the influence of school time-shift and teachers’ intentions to quit or transfer are needed to affirm the results in this study. This is the first study about the influence of school characteristics on teacher turnover in public schools in Oman. Thus, the value of this study stems from the uniqueness of this study which may serve as an eye opening indicator about teacher turnover in Oman.

  20. Nonlicensed employee turnover in a long-term care facility.

    Science.gov (United States)

    Gaddy, T; Bechtel, G A

    1995-06-01

    The purpose of this study was to analyze nonlicensed employee turnover in a long-term care facility using Maslow's hierarchy of needs as a framework. During exit interviews, a convenience sample of 34 employees completed an attitudes and beliefs survey regarding their work environment. Findings were mixed; 39.6 percent of the employees stated positive personal relationships were a strength of the organization, although 24.3 percent resigned because of personal/staff conflicts. Financial concerns were not a major factor in their resignations. The study suggests that decreasing nonlicensed employee stress and increasing their personal satisfaction with patient care may decrease employee turnover.

  1. Role of Transactional and Relational Contract in Employee Turnover Intention (A Study of Business Affiliated Institutions Employees of Peshawar Pakistan)

    OpenAIRE

    Shahzad Khan; Saqib Shahzad; Raza Ullah; Qaiser Khan; Danish Wasim

    2012-01-01

    The aim of this research was to investigate the impact of transactional and Relational contract on turn over intention in employees of Peshawar University business affiliated institutions in region of Peshawar Pakistan. The effect of both contracts on the turnover intention was investigated individually. A sample size of one hundred individuals was used in the study. For the analysis part of study hypothesis were developed and regression and correlation analysis was used. The study revealed t...

  2. The Efect of Semelil (AngiparsW on Bone Resorption and Bone Formation Markers in Type 2 Diabetic Patients

    Directory of Open Access Journals (Sweden)

    Shirin Hasani-Ranjbar

    2012-01-01

    Full Text Available Background and purpose of the study: Diabetes mellitus has been recognized as a major risk factor for osteoporosis in which bone turnover is affected by different mechanisms. As the morbidity, mortality and financial cost related to osteoporosis are expected to rise in Iran in coming years, and considering the efficacy of AngiparsW for improvement of different ulcers which made it a new herbal drug in diabetic foot ulcer, there is a need toevaluate the effect of this new drug on different organs including bone resorption and bone formation markers.Methods: In this randomized, double- blind clinical trial, 61 diabetic patients were included. The subjects wererandomly divided into intervention and control groups. Subjects of intervention group received 100 mg of AngiparsW twice a day. Laboratory tests including bone resorption and bone formation markers were performed at baseline and after 3 months.Result: 31 patients in study group and 30 patients in control group finished the study. The mean age of the studypopulation and the mean disease duration was respectively 51.8 ± 6.2 and 7.5 ± 4.7 years with no significant differences between intervention and control patients. No statistically significant differences between patients and controls were observed in pyridinoline, osteocalcin, urine calcium, bone alkaline phosphatase and tumor necrosis factor (TNF-α. Only urine creatinine level significantly changed between two groups after 3 month of treatment (pvalue:0.029Conclusion: In conclusion, the findings of this study indicate that Semelil (AngiparsW had no beneficial or harmfuleffects on bone. It might be other effects of this new component on bone turnover process which need morestudies and more time to be discovered.

  3. The effect of semelil (angipars® on bone resorption and bone formation markers in type 2 diabetic patients

    Directory of Open Access Journals (Sweden)

    Hasani-Ranjbar Shirin

    2012-12-01

    Full Text Available Abstract Background and purpose of the study Diabetes mellitus has been recognized as a major risk factor for osteoporosis in which bone turnover is affected by different mechanisms. As the morbidity, mortality and financial cost related to osteoporosis are expected to rise in Iran in coming years, and considering the efficacy of Angipars® for improvement of different ulcers which made it a new herbal drug in diabetic foot ulcer, there is a need to evaluate the effect of this new drug on different organs including bone resorption and bone formation markers. Methods In this randomized, double- blind clinical trial, 61 diabetic patients were included. The subjects were randomly divided into intervention and control groups. Subjects of intervention group received 100 mg of Angipars® twice a day. Laboratory tests including bone resorption and bone formation markers were performed at baseline and after 3 months. Result 31 patients in study group and 30 patients in control group finished the study. The mean age of the study population and the mean disease duration was respectively 51.8 ± 6.2 and 7.5 ± 4.7 years with no significant differences between intervention and control patients. No statistically significant differences between patients and controls were observed in pyridinoline, osteocalcin, urine calcium, bone alkaline phosphatase and tumor necrosis factor (TNF-α. Only urine creatinine level significantly changed between two groups after 3 month of treatment (p-value: 0.029 Conclusion In conclusion, the findings of this study indicate that Semelil (Angipars® had no beneficial or harmful effects on bone. It might be other effects of this new component on bone turnover process which need more studies and more time to be discovered.

  4. Similar processes but different environmental filters for soil bacterial and fungal community composition turnover on a broad spatial scale.

    Directory of Open Access Journals (Sweden)

    Nicolas Chemidlin Prévost-Bouré

    Full Text Available Spatial scaling of microorganisms has been demonstrated over the last decade. However, the processes and environmental filters shaping soil microbial community structure on a broad spatial scale still need to be refined and ranked. Here, we compared bacterial and fungal community composition turnovers through a biogeographical approach on the same soil sampling design at a broad spatial scale (area range: 13300 to 31000 km2: i to examine their spatial structuring; ii to investigate the relative importance of environmental selection and spatial autocorrelation in determining their community composition turnover; and iii to identify and rank the relevant environmental filters and scales involved in their spatial variations. Molecular fingerprinting of soil bacterial and fungal communities was performed on 413 soils from four French regions of contrasting environmental heterogeneity (Landesturnovers. The relative importance of processes and filters was assessed by distance-based redundancy analysis. This study demonstrates significant community composition turnover rates for soil bacteria and fungi, which were dependent on the region. Bacterial and fungal community composition turnovers were mainly driven by environmental selection explaining from 10% to 20% of community composition variations, but spatial variables also explained 3% to 9% of total variance. These variables highlighted significant spatial autocorrelation of both communities unexplained by the environmental variables measured and could partly be explained by dispersal limitations. Although the identified filters and their hierarchy were dependent on the region and organism, selection was systematically based on a common group of environmental variables: pH, trophic resources, texture and land use. Spatial autocorrelation was also important at

  5. Osteoclasts prefer aged bone

    DEFF Research Database (Denmark)

    Henriksen, K; Leeming, Diana Julie; Byrjalsen, I;

    2007-01-01

    We investigated whether the age of the bones endogenously exerts control over the bone resorption ability of the osteoclasts, and found that osteoclasts preferentially develop and resorb bone on aged bone. These findings indicate that the bone matrix itself plays a role in targeted remodeling...

  6. Lycopene treatment against loss of bone mass, microarchitecture and strength in relation to regulatory mechanisms in a postmenopausal osteoporosis model.

    Science.gov (United States)

    Ardawi, Mohammed-Salleh M; Badawoud, Mohammed H; Hassan, Sherif M; Rouzi, Abdulrahim A; Ardawi, Jumanah M S; AlNosani, Nouf M; Qari, Mohammed H; Mousa, Shaker A

    2016-02-01

    Lycopene supplementation decreases oxidative stress and exhibits beneficial effects on bone health, but the mechanisms through which it alters bone metabolism in vivo remain unclear. The present study aims to evaluate the effects of lycopene treatment on postmenopausal osteoporosis. Six-month-old female Wistar rats (n=264) were sham-operated (SHAM) or ovariectomized (OVX). The SHAM group received oral vehicle only and the OVX rats were randomized into five groups receiving oral daily lycopene treatment (mg/kg body weight per day): 0 OVX (control), 15 OVX, 30 OVX, and 45 OVX, and one group receiving alendronate (ALN) (2μg/kg body weight per day), for 12weeks. Bone densitometry measurements, bone turnover markers, biomechanical testing, and histomorphometric analysis were conducted. Micro computed tomography was also used to evaluate changes in microarchitecture. Lycopene treatment suppressed the OVX-induced increase in bone turnover, as indicated by changes in biomarkers of bone metabolism: serum osteocalcin (s-OC), serum N-terminal propeptide of type 1 collagen (s-PINP), serum crosslinked carboxyterminal telopeptides (s-CTX-1), and urinary deoxypyridinoline (u-DPD). Significant improvement in OVX-induced loss of bone mass, bone strength, and microarchitectural deterioration was observed in lycopene-treated OVX animals. These effects were observed mainly at sites rich in trabecular bone, with less effect in cortical bone. Lycopene treatment down-regulated osteoclast differentiation concurrent with up-regulating osteoblast together with glutathione peroxidase (GPx) catalase (CAT) and superoxide dismutase (SOD) activities. These findings demonstrate that lycopene treatment in OVX rats primarily suppressed bone turnover to restore bone strength and microarchitecture.

  7. Modifications of histamine receptor signaling affect bone mechanical properties in rats.

    Science.gov (United States)

    Folwarczna, Joanna; Janas, Aleksandra; Pytlik, Maria; Śliwiński, Leszek; Wiercigroch, Marek; Brzęczek, Anna

    2014-02-01

    Histamine receptors are expressed on bone cells and histamine may be involved in regulation of bone metabolism. The aim of the present study was to investigate the effects of loratadine (an H(1) receptor antagonist), ranitidine (an H(2) receptor antagonist) and betahistine (an H(3) receptor antagonist and H(1) receptor agonist) on bone mechanical properties in rats. Loratadine (5 mg/kg/day, po), ranitidine (50 mg/kg/day, po), or betahistine dihydrochloride (5 mg/kg/day, po), were administered for 4 weeks to non-ovariectomized and bilaterally ovariectomized (estrogen-deficient) 3-month-old rats, and their effects were compared with appropriate controls. Serum levels of bone turnover markers, bone mineralization and mechanical properties of the proximal tibial metaphysis, femoral diaphysis and femoral neck were studied. In rats with normal estrogen level, administration of loratadine slightly favorably affected mechanical properties of compact bone, significantly increasing the strength of the femoral neck (p < 0.05), and tending to increase the strength of the femoral diaphysis. Ranitidine did not significantly affect the investigated parameters, and betahistine decreased the strength of the tibial metaphysis (cancellous bone, p < 0.01). There were no significant effects of the drugs on serum bone turnover markers. In estrogen-deficient rats, the drugs did not significantly affect the investigated skeletal parameters. In conclusion, the effects of histamine H(1), H(2) and H(3) receptor antagonists on the skeletal system in rats were differential and dependent on estrogen status. PMID:24905313

  8. Bone remodeling during pregnancy and post-partum assessed by metal lead levels and isotopic concentrations.

    Science.gov (United States)

    Gulson, Brian; Taylor, Alan; Eisman, John

    2016-08-01

    Bone remodeling is normally evaluated using bone turnover markers/indices as indicators of bone resorption and formation. However, during pregnancy and post-partum, there have been inconsistent results between and within biomarkers for bone formation and resorption. These differences may relate to pregnancy-related changes in metabolism and/or hemodilution altering measured marker levels. An alternative approach to evaluating bone remodeling is to use the metal lead (Pb) concentrations and Pb isotopic compositions in blood. These measurements can also provide information on the amount of Pb that is mobilized from the maternal skeleton. Despite some similarities with accepted bone turnover markers, the Pb data demonstrate increased bone resorption throughout pregnancy that further continues post-partum independent of length of breast-feeding, dietary intake and resumption of menses. Furthermore the isotopic measurements are not affected by hemodilution. These data confirm calcium balance studies that indicate increased bone resorption throughout pregnancy and lactation. They also indicate potentially major public health implications of the transfer of maternal Pb burden to the fetus and new born. PMID:27233973

  9. Principal Turnover: Upheaval and Uncertainty in Charter Schools?

    Science.gov (United States)

    Ni, Yongmei; Sun, Min; Rorrer, Andrea

    2015-01-01

    Purpose: Informed by literature on labor market and school choice, this study aims to examine the dynamics of principal career movements in charter schools by comparing principal turnover rates and patterns between charter schools and traditional public schools. Research Methods/Approach: This study uses longitudinal data on Utah principals and…

  10. Relationships between Emotional Labor, Job Performance, and Turnover

    Science.gov (United States)

    Goodwin, Robyn E.; Groth, Markus; Frenkel, Stephen J.

    2011-01-01

    The present study investigates the relationship between the emotional labor strategies surface acting and deep acting and organizational outcomes, specifically, employees' overall job performance and turnover. Call center employees from two large financial service organizations completed an online survey about their use of surface and deep acting.…

  11. The Effects of Turnover: What We Know about Teacher Attrition

    Science.gov (United States)

    DeAngelis, Karen

    2012-01-01

    School business officials are likely to know better than anyone else about the financial costs to districts and schools associated with teacher attrition. Perhaps less well-known, though, is what else has been learned about this issue in recent years--information that may affect how one thinks about teacher turnover. Here is some of that research:…

  12. Sustaining Effective Practices in the Face of Principal Turnover

    Science.gov (United States)

    Strickland-Cohen, M. Kathleen; McIntosh, Kent; Horner, Robert H.

    2014-01-01

    In the face of principal turnover, a common approach taken by staff is to simply wait until the new school year begins and hope that the new administrator will continue to support current programs. It is our experience that this passive strategy is not as helpful, because there are proactive approaches that are more likely to be successful. The…

  13. Chinese Teachers' Work Stress and Their Turnover Intention

    Science.gov (United States)

    Liu, Shujie; Onwuegbuzie, Anthony J.

    2012-01-01

    This survey study employed qualitative dominant mixed research to explore the sources of teacher stress in China and the possible reasons for Chinese teachers' turnover intention. The data were collected in Jilin Province of China, and 510 teachers participated in the survey. Quantitatively, 40.4% of the surveyed teachers reported that they…

  14. Ectomycorrhizal fungal mycelia turnover in a longleaf pine forest.

    Science.gov (United States)

    Hendricks, Joseph J; Mitchell, Robert J; Kuehn, Kevin A; Pecot, Stephen D

    2016-03-01

    Elucidation of the patterns and controls of carbon (C) flow and nitrogen (N) cycling in forests has been hindered by a poor understanding of ectomycorrhizal fungal mycelia (EFM) dynamics. In this study, EFM standing biomass (based on soil ergosterol concentrations), production (based on ergosterol accrual in ingrowth cores), and turnover rate (the quotient of annual production and average standing biomass estimates) were assessed in a 25-yr-old longleaf pine (Pinus palustris) plantation where C flow was manipulated by foliar scorching and N fertilization for 5 yr before study initiation. In the controls, EFM standing biomass was 30 ± 7 g m(-2) , production was 279 ± 63 g m(-2)  yr(-1) , and turnover rate was 10 ± 3 times yr(-1) . The scorched × fertilized treatment had significantly higher EFM standing biomass (38 ± 8 g m(-2) ), significantly lower production (205 ± 28 g m(-2)  yr(-1) ), and a trend of decreased turnover rate (6 ± 1 times yr(-1) ). The EFM turnover estimates, which are among the first reported for natural systems, indicate that EFM are a dynamic component of ecosystems, and that conventional assessments have probably underestimated the role of EFM in C flow and nutrient cycling. PMID:26537020

  15. Hypoxic cell turnover in different solid tumor lines.

    NARCIS (Netherlands)

    Ljungkvist, A.; Bussink, J.; Kaanders, J.H.A.M.; Rijken, P.F.J.W.; Begg, A.C.; Raleigh, J.A.; Kogel, A.J. van der

    2005-01-01

    PURPOSE: Most solid tumors contain hypoxic cells, and the amount of tumor hypoxia has been shown to have a negative impact on the outcome of radiotherapy. The efficacy of combined modality treatments depends both on the sequence and timing of the treatments. Hypoxic cell turnover in tumors may be im

  16. Organizational Career Growth, Affective Occupational Commitment and Turnover Intentions

    Science.gov (United States)

    Weng, Qingxiong; McElroy, James C.

    2012-01-01

    Survey data, collected from the People's Republic of China, were used to test Weng's (2010) four facet model of career growth and to examine its effect on occupational commitment and turnover intentions. Weng conceptualized career growth as consisting of four factors: career goal progress, professional ability development, promotion speed, and…

  17. Employees as Customers: Exploring Service Climate, Employee Patronage, and Turnover

    Science.gov (United States)

    Abston, Kristie A.; Kupritz, Virginia W.

    2011-01-01

    The role of retail employees as customers was explored by quantitatively examining the influence of service climate and employee patronage on employee turnover intentions. Employees representing all shifts in two stores of a national retailer participated. Results indicated that employee patronage partially mediates the effects of service climate…

  18. Turnover and Mobility: A Management Problem for Small Dailies?

    Science.gov (United States)

    Tharp, Marty

    A study examined the effects of employee turnover (employees who were fired, laid off, retired, or left for other reasons) and mobility (employees who left one newspaper to work for another newspaper or other journalism medium) on small daily newspapers (under 25,000 circulation). The study surveyed 300 newsroom editors and 600 reporters (with a…

  19. Endogenous surfactant turnover in preterm infants measured with stable isotopes

    NARCIS (Netherlands)

    J.E.H. Bunt (Jan Erik); L.J.I. Zimmermann (Luc); J.L.D. Wattimena (Josias); R.H.Th. van Beek (Ron); P.J.J. Sauer (Pieter); V.P. Carnielli (Virgilio)

    1998-01-01

    textabstractWe studied surfactant synthesis and turnover in vivo in preterm infants using the stable isotope [U-13C]glucose, as a precursor for the synthesis of palmitic acid in surfactant phosphatidylcholine (PC). Six preterm infants (birth weight, 916 +/- 244 g; gesta

  20. Turnover of nursing employees in a Gauteng hospital group

    Directory of Open Access Journals (Sweden)

    Japie Greyling

    2010-03-01

    Full Text Available Orientation: The South African nursing profession is in a crisis as professional nurses leave the country in search of lucrative work overseas.Research purpose: The purpose of this study was to investigate individual determinants of voluntary turnover to identify a risk-group profile.Motivation for the study: Nursing employers should have a clearer understanding of the dynamics around nurses’ turnover behaviour and embark on strategies to retain their talent.Research design, approach and method: A survey measuring voluntary turnover was conducted among 262 professional and assistant nurses in three selected hospitals in Gauteng province using the McCarthy, Tyrrell and Cronin (2002 instrument. Pearson’s chi square with Yates’s continuity correction tested the relationship among the variables presented in a contingency table, in other words the risk group and each of the individual determinants.Main findings: Discontent with salaries was the major determinant of the nurses’ resignation. Organisational causes were nursing practices, the work environment, physical-emotional costs and employment opportunities after resignation.Practical/managerial implications: Hospital management could indeed establish a good rapport with nursing staff while facilitating respectful and ethical conduct by doctors towards nursing staff. Putting into place effective labour practices and business strategies could improve job satisfaction in the workplace.Contribution/value-add: This study contributed to a greater understanding of the personal and organisational determinants of the turnover of nurses in South African hospitals.