998 resultados para bone phosphate
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Ewing's sarcoma is a member of Ewing's family tumors (EFTs) and the second most common solid bone and soft tissue malignancy of children and young adults. It is associated in 85% of cases with the t(11;22)(q24:q12) chromosomal translocation that generates fusion of the 5' segment of the EWS gene with the 3' segment of the ETS family gene FLI-1. The EWS-FLI-1 fusion protein behaves as an aberrant transcriptional activator and is believed to contribute to EFT development. However, EWS-FLI-1 induces growth arrest and apoptosis in normal fibroblasts, and primary cells that are permissive for its putative oncogenic properties have not been discovered, hampering basic understanding of EFT biology. Here, we show that EWS-FLI-1 alone can transform primary bone marrow-derived mesenchymal progenitor cells and generate tumors that display hallmarks of Ewing's sarcoma, including a small round cell phenotype, expression of EFT-associated markers, insulin like growth factor-I dependence, and induction or repression of numerous EWS-FLI-1 target genes. These observations provide the first identification of candidate primary cells from which EFTs originate and suggest that EWS-FLI-1 expression may constitute the initiating event in EFT pathogenesis.
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BACKGROUND: Intracoronary injection of autologous bone marrow-derived mononucleated cells (BM-MNC) may improve LV function shortly after acute ST elevation myocardial infarction (STEMI), but little is known about the long-term durability of the treatment effect. METHODS: In a single-centre trial a total of 60 patients with acute anterior STEMI, successful reperfusion therapy and a left ventricular ejection fraction (LVEF) of <50% were screened for the study. 23 patients were actively treated with intracoronary infusion of BM-MNC within a median of 3 days. The open-label control group consisted of 19 patients who did not consent to undergo BM-MNC treatment but agreed to undergo regular clinical and echocardiographic follow-up for up to 5 years after AMI. RESULTS: Whereas at 4 months there was no significant difference between the increase in LVEF in the BM-MNC group and the control group (+7.0%, 95%CI 3.6; 10.4) vs. +3.9%, 95%CI -2.1; 10), the absolute increase at 5 years remained stable in the BM-MNC but not in the control group (+7.95%, 95%CI 3.5; 12.4 vs. -0.5%, 95%CI -5.4; 4.4; p for interaction between groups = 0.035). DISCUSSION: In this single-centre, open-labelled study, intracoronary administration of BM-MNC is feasible and safe in the short term. It is also associated with sustained improvement of left ventricular function in patients with acute myocardial infarction, encouraging phase III studies to examine the potential BM-MNC effect on clinical outcome.
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To have an added value over BMD, a CRF of osteoporotic fracture must be predictable of the fracture, independent of BMD, reversible and quantifiable. Many major recognized CRF exist. Out of these factors many of them are indirect factor of bone quality. TBS predicts fracture independently of BMD as demonstrated from previous studies. The aim of the study is to verify if TBS can be considered as a major CRF of osteoporotic fracture. Existing validated datasets of Caucasian women were analyzed. These datasets stem from different studies performed by the authors of this report or provided to our group. However, the level of evidence of these studies will vary. Thus, the different datasets were weighted differently according to their design. This meta-like analysis involves more than 32000 women (≥50years) with 2000 osteoporotic fractures from two prospective studies (OFELY&MANITOBA) and 7 cross-sectional studies. Weighted relative risk (RR) for TBS was expressed for each decrease of one standard deviation as well as per tertile difference (TBS=1.300 and 1.200) and compared with those obtained for the major CRF included in FRAX®. Overall TBS RR obtained (adjusted for age) was 1.79 [95%CI-1.37-2.37]. For all women combined, RR for fracture for the lowest compared with the middle TBS tertile was 1.55[1.46-1.68] and for the lowest compared with the highest TBS tertile was 2.8[2.70-3.00]. TBS is comparable to most of the major CRF and thus could be used as one of them. Further studies have to be conducted to confirm these first findings.
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BACKGROUND: Protein-energy wasting is a frequent and debilitating condition in maintenance dialysis. We randomly tested if an energy-dense, phosphate-restricted, renal-specific oral supplement could maintain adequate nutritional intake and prevent malnutrition in maintenance haemodialysis patients with insufficient intake. METHODS: Eighty-six patients were assigned to a standard care (CTRL) group or were prescribed two 125-ml packs of Renilon 7.5(R) daily for 3 months (SUPP). Dietary intake, serum (S) albumin, prealbumin, protein nitrogen appearance (nPNA), C-reactive protein, subjective global assessment (SGA) and quality of life (QOL) were recorded at baseline and after 3 months. RESULTS: While intention to treat analysis (ITT) did not reveal strong statistically significant changes in dietary intake between groups, per protocol (PP) analysis showed that the SUPP group increased protein (P < 0.01) and energy (P < 0.01) intakes. In contrast, protein and energy intakes further deteriorated in the CTRL group (PP). Although there was no difference in serum albumin and prealbumin changes between groups, in the total population serum albumin and prealbumin changes were positively associated with the increment in protein intake (r = 0.29, P = 0.01 and r = 0.27, P = 0.02, respectively). The SUPP group did not increase phosphate intake, phosphataemia remained unaffected, and the use of phosphate binders remained stable or decreased. The SUPP group exhibited improved SGA and QOL (P < 0.05). CONCLUSION: This study shows that providing maintenance haemodialysis patients with insufficient intake with a renal-specific oral supplement may prevent deterioration in nutritional indices and QOL without increasing the need for phosphate binders.
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Allergen-induced bone marrow responses are observable in human allergic asthmatics, involving specific increases in eosinophil-basophil progenitors (Eo/B-CFU), measured either by hemopoietic assays or by flow cytometric analyses of CD34-positive, IL-3Ralpha-positive, and/or IL-5-responsive cell populations. The results are consistent with the upregulation of an IL-5-sensitive population of progenitors in allergen-induced late phase asthmatic responses. Studies in vitro on the phenotype of developing eosinophils and basophils suggest that the early acquisition of IL-5Ralpha, as well as the capacity to produce cytokines such as GM-CSF and IL-5, are features of the differentiation process. These observations are consistent with findings in animal models, indicating that allergen-induced increases in bone marrow progenitor formation depend on hemopoietic factor(s) released post-allergen. The possibility that there is constitutive marrow upregulation of eosinophilopoiesis in allergic airways disease is also an area for future investigation.
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Objectives: Trabecular Bone Score (TBS, Med-Imaps, France) is an index of bone microarchitecture calculated from antero-posterior spine DXA scan and reported to be associated with fracture in prior case-control studies and in a large prospective study with the Prodigy DXA device. Our aim was to assess the ability of TBS to predict incident fracture and improve the classification of fracture prospectively in the OFELY study.Materials/Methods: TBS was assessed in 564 postmenopausal women (66±8 years old) from the OFELY cohort, who had a spine DXA scan (QDR 4500A, Hologic, USA) between year 2000 and 2001. During a mean follow up of 7.8±1.3 years, 94 women sustained a fragility fracture.Results: At the time of baseline DXA scan, women with incident fracture were significantly older (70±9 vs. 65± 8 years), had a lower spine BMD (T-score: −1.9±1.2 vs. −1.3±1.3, p<0.001) and spine TBS (−3.1%, p<0.001) than women without incident fracture. After adjustment for age, BMI and the presence of prevalent fracture, the magnitude of fracture prediction was similar for spine BMD (OR=1.42 [1.11;1.82] per SD decrease [95% CI]) and TBS (OR=1.34 [1.04;1.74]) but the combination of TBS and spine BMD did not improve fracture prediction. Spine BMD and TBS were both correlated with age (respectively r=−0.17 and −0.49, p<0.001) and correlated together with 39% of TBS explained by spine BMD (r=0.63, p<0.001). When using the WHO classification, 38% of the fractures occurred in osteoporotic (fracture rate=29%), 47% in osteopenic (fracture rate=16%) and 15% in women with T-score >−1 (fracture rate=9%). By classifying our population in tertiles of TBS, we found that 47% of the fractures occurred in the lowest tertile of TBS (fracture rate=23%) and 39% of the fracture that occurred in osteopenic women were in the lowest tertile of TBS.Conclusions: Spine BMD and TBS predicted fractures equally well. The addition of TBS to spine BMD added only limited information on fracture risk prediction in our cohort when considering the all range of BMD. Nevertheless combining the osteopenic T-score and the lowest TBS helped defining a subset of osteopenic women at higher risk of fracture.Disclosure of Interest: None declared.
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Ballet dancers have on average a low bone mineral content (BMC), with elevated fracture-risk, low body mass index (BMI) for age (body mass index, kg/m2), low energy intake, and delayed puberty. This study aims at a better understanding of the interactions of these factors, especially with regard to nutrition. During a competition for pre-professional dancers we examined 127 female participants (60 Asians, 67 Caucasians). They averaged 16.7 years of age, started dancing at 5.8 years, and danced 22 hours/week. Assessments were made for BMI, BMC (DXA), and bone mineral apparent density (BMAD) at the lumbar spine and femoral neck, pubertal stage (Tanner score), and nutritional status (EAT-40 questionnaire and a qualitative three-day dietary record). BMI for age was found to be normal in only 42.5% of the dancers, while 15.7% had a more or less severe degree of thinness (12.6% Grade2 and 3.1% Grade 3 thinness). Menarche was late (13.9 years, range 11 to 16.8 years). Food intake, evaluated by number of consumed food portions, was below the recommendations for a normally active population in all food groups except animal proteins, where the intake was more than twice the recommended amount. In this population, with low BMI and intense exercise, BMC was low and associated with nutritional factors; dairy products had a positive and non-dairy proteins a negative influence. A positive correlation between BMAD and years since menarche confirmed the importance of exposure to estrogens and the negative impact of delayed puberty. Because of this and the probable negative influence of a high intake of non-dairy proteins, such as meat, fish, and eggs, and the positive association with a high dairy intake, ballet schools should promote balanced diets and normal weight and should recognize and help dancers avoid eating disorders and delayed puberty caused by extensive dancing and inadequate nutrition.
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The measurement of BMD by dual-energy X-ray absorptiometry (DXA) is the "gold standard" for diagnosing osteoporosis but does not directly reflect deterioration in bone microarchitecture. The trabecular bone score (TBS), a novel gray-level texture measurement that can be extracted from DXA images, correlates with 3D parameters of bone microarchitecture. Our aim was to evaluate the ability of lumbar spine TBS to predict future clinical osteoporotic fractures. A total of 29,407 women 50 years of age or older at the time of baseline hip and spine DXA were identified from a database containing all clinical results for the Province of Manitoba, Canada. Health service records were assessed for the incidence of nontraumatic osteoporotic fracture codes subsequent to BMD testing (mean follow-up 4.7 years). Lumbar spine TBS was derived for each spine DXA examination blinded to clinical parameters and outcomes. Osteoporotic fractures were identified in 1668 (5.7%) women, including 439 (1.5%) spine and 293 (1.0%) hip fractures. Significantly lower spine TBS and BMD were identified in women with major osteoporotic, spine, and hip fractures (all p < 0.0001). Spine TBS and BMD predicted fractures equally well, and the combination was superior to either measurement alone (p < 0.001). Spine TBS predicts osteoporotic fractures and provides information that is independent of spine and hip BMD. Combining the TBS trabecular texture index with BMD incrementally improves fracture prediction in postmenopausal women. © 2011 American Society for Bone and Mineral Research.
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Introduction: The presence of intra-articular basic calcium phosphate (BCP) crystals, including OCP, carbonated-apatite, hydroxyapatite and tricalcium phosphate crystals, is associated with severe osteoarthritis and destructive arthropathies such as Milwaukee shoulder. Although BCP crystals displayed, in vitro, mitogenic, anabolic and catabolic responses, their intra-articular effect was never assessed.Objective: To determine the effects of OCP crystals in joints in vivo.Methods: OCP crystals (200 ug in 20 ml PBS) were injected into the right knee joint (the contra-lateral knee joint injected with 20 ul of PBS serving as a control) of wild-type mice treated or not by the IL1R antagonist Anakinra or mice deficient for the inflammasome proteins ASC and NALP3. 4 days and 17 days after crystal injection, mice were sacrificed and knee joints dissected. Histological scoring for synovial inflammation and characterisation of macrophages, neutrophils and T cells were performed. Technetium (Tc) uptake was measured at 6h, 1 and 4 days after OCP injection. Cartilage degradation was evaluated by Safranin O staining and VDIPEN immunohistochemistry. Intra-articular localisation of injected OCP crystals was evidenced by Von Kossa staining.Results: The intra-articular localisation of injected OCP crystals was evidenced by Von Kossa staining performed on non-decalcified samples embedded in methyl-metacrylate. Injection of OCP crystals into knee joints led at day 4 to an inflammatory response with intense macrophage staining and also some neutrophil recruitment in the synovial membrane. This synovitis was not accompanied by increased Tc uptake into the knee joint, Tc uptake being similar in OCP crystal injected knee or control knee at all time points investigated (6h, 1 day, 4 days). The histological modifications persisted over 17 days, with an additional fibrosis evidenced at this later time-point. The OCP crystal-induced synovitis was totally IL-1a and IL-1 independent as shown by the absence of inhibitory effects of anakinra injected into wild-type mice. Accordingly, OCP crystal-induced synovitis was similar in ASC-/- and NALP3-/- mice as no alterations of inflammation were demonstrated between these mice groups. Concerning cartilage matrix degradation, OCP crystals induced a strong breakdown of proteoglycans 4 and 17 days after injection, as measured by loss of red staining from Safranin O-stained sections of cartilage surfaces. In addition, we also measured advanced cartilage matrix destruction mediated by MMPs, as evidenced by VDIPEN staining of cartilage. OCP-mediated cartilage degradation was similar in all experimental conditions tested (WT+Anakinra, or ASC or NALP3 deficient mice).Conclusion: These data indicate in vivo that the intra-articular presence of OCP crystals is associated with cartilage destruction along with synovial inflammation. This is an interesting and new model of destructive arthropathy related to BCP crystals which will allow to assess new therapies in this disease.
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Inorganic phosphate (Pi) homeostasis in multi-cellular eukaryotes depends not only on Pi influx into cells, but also on Pi efflux. Examples in plants for which Pi efflux is crucial are transfer of Pi into the xylem of roots and release of Pi at the peri-arbuscular interface of mycorrhizal roots. Despite its importance, no protein has been identified that specifically mediates phosphate efflux either in animals or plants. The Arabidopsis thaliana PHO1 gene is expressed in roots, and was previously shown to be involved in long-distance transfer of Pi from the root to the shoot. Here we show that PHO1 over-expression in the shoot of A. thaliana led to a two- to threefold increase in shoot Pi content and a severe reduction in shoot growth. (31) P-NMR in vivo showed a normal initial distribution of intracellular Pi between the cytoplasm and the vacuole in leaves over-expressing PHO1, followed by a large efflux of Pi into the infiltration medium, leading to a rapid reduction of the vacuolar Pi pool. Furthermore, the Pi concentration in leaf xylem exudates from intact plants was more than 100-fold higher in PHO1 over-expressing plants compared to wild-type. Together, these results show that PHO1 over-expression in leaves leads to a dramatic efflux of Pi out of cells and into the xylem vessel, revealing a crucial role for PHO1 in Pi efflux.
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Between 1985 and 1990 we treated 11 large segmental bone defects (average 6.7 cm) in ten patients with the Ilizarov technique. Open fractures, type III according to Gustilo, represented the largest group (8 of 11 cases). The average delay before the Ilizarov technique was initiated was 8.9 months. The external fixator was usually maintained for 1 year. Bone regeneration was obtained in every case. Consolidation was not fulfilled with this technique in three cases. The complications observed were one refracture, four leg-length discrepancies (average 1.5 cm), and five axial deformities exceeding 5 degrees. No pin-track infection was observed. In our limited series of four type IIIC open fractures treated by the Ilizarov technique, no patients required amputation. The Ilizarov technique is particularly useful in the treatment of large bone defects, without major complications, especially if there is an adequate initial debridement.