701 research outputs found

    Role of interleukin-10 in endochondral bone formation in mice: Anabolic effect via the bone morphogenetic protein/Smad pathway

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    Objective: Interleukin-10 (IL-10) is a pleiotropic immunoregulatory cytokine with a chondroprotective effect that is elevated in cartilage and synovium in patients with osteoarthritis. However, the role of IL-10 during endochondral bone formation and its mechanism of action have not been elucidated. Methods: IL-10-/- mice and IL-10-treated tibial organ cultures were used to study loss and gain of IL-10 functions, respectively, during endochondral bone formation. Primary chondrocytes from the long bones of mouse embryos were cultured with and without IL-10. To assess the role of IL-10 in chondrogenic differentiation, we conducted mesenchymal cell micromass cultures. Results: The lengths of whole skeletons from IL-10-/- mice were similar to those of their wild-type littermates, although their skull diameters were smaller. The tibial growth plates of IL-10-/- mice showed shortening of the proliferating zone. Treatment with IL-10 significantly increased tibial lengths in organ culture. IL-10 also induced chondrocyte proliferation and hypertrophic differentiation in primary chondrocytes in vitro. Mechanistically, IL-10 activated STAT-3 and the Smad1/5/8 and ERK-1/2 MAP kinase pathways and induced the expression of bone morphogenetic protein 2 (BMP-2) and BMP-6 in primary chondrocytes. Furthermore, the blocking of BMP signaling attenuated the IL-10-mediated induction of cyclin D1 and RUNX-2 in primary chondrocytes and suppressed Alcian blue and alkaline phosphatase staining in mesenchymal cell micromass cultures. Conclusion: These results indicate that IL-10 acts as a stimulator of chondrocyte proliferation and chondrogenic or hypertrophic differentiation via activation of the BMP signaling pathway. © 2013, American College of Rheumatology

    Androgen action on renal calcium and phosphate handling: Effects of bisphosphonate treatment and low calcium diet

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    Renal calcium and phosphate handling is an important contributor to mineral homeostasis and bone health and the androgen receptor (AR) is highly expressed in the kidney. We investigated the short term effects of androgen deprivation on renal calcium and phosphate reabsorption, independent of their effects on bone. Two weeks following orchidectomy (ORX) of adult mice, bone loss occurred along with hypercalciuria, which was similarly prevented by testosterone and dihydrotestosterone supplementation. Treatment with bisphosphonates prior to ORX also inhibited hypercalciuria, indicating that the calcium flux originated from the bone. Renal calcium and phosphate transporter expression was increased post-ORX, independent of bisphosphonates. Furthermore, androgen deprivation appeared to stimulate local synthesis of 1,25(OH)2D3. When bisphosphonate-treated mice were fed a low calcium diet, bone resorption was no longer blocked and secondary hyperparathyroidism developed, which was more pronounced in ORX mice than sham-operated mice. In conclusion, this study shows that androgen deprivation increased renal calcium and phosphate transporter expression, independent of bone, and underlines the importance of adequate intestinal calcium supply in circumstances of androgen deprivation and bisphosphonate treatment.status: publishe

    Patterns of bruising in preschool children with inherited bleeding disorders: a longitudinal study

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    Objective The extent that inherited bleeding disorders affect; number, size and location of bruises in young children <6 years. Design Prospective, longitudinal, observational study. Setting Community. Patients 105 children with bleeding disorders, were compared with 328 without a bleeding disorder and classified by mobility: premobile (non-rolling/rolling over/ sitting), early mobile (crawling/cruising) and walking and by disease severity: severe bleeding disorder factor VIII/IX/XI <1 IU/dL or type 3 von Willebrand disease. Interventions Number, size and location of bruises recorded in each child weekly for up to 12 weeks. Outcomes The interventions were compared between children with severe and mild/moderate bleeding disorders and those without bleeding disorders. Multiple collections for individual children were analysed by multilevel modelling. Results Children with bleeding disorders had more and larger bruises, especially when premobile. Compared with premobile children without a bleeding disorder; the modelled ratio of means (95% CI) for number of bruises/ collection was 31.82 (8.39 to 65.42) for severe bleeding disorders and 5.15 (1.23 to 11.17) for mild/moderate, and was 1.81 (1.13 to 2.23) for size of bruises. Children with bleeding disorders rarely had bruises on the ears, neck, cheeks, eyes or genitalia. Conclusions Children with bleeding disorder have more and larger bruises at all developmental stages. The differences were greatest in premobile children. In this age group for children with unexplained bruising, it is essential that coagulation studies are done early to avoid the erroneous diagnosis of physical abuse when the child actually has a serious bleeding disorder, however a blood test compatible with a mild/moderate bleeding disorder cannot be assumed to be the cause of bruising

    Early effects of androgen deprivation on bone and mineral homeostasis in adult men: a prospective cohort study

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    Objective: Long-term androgen deprivation therapy (ADT) negatively influences bone. The short term effects on bone and mineral homeostasis are less known. Therefore, we aimed to investigate the early effects of ADT on calcium/phosphate homeostasis and bone turnover. Design: Prospective cohort study Methods: Eugonadal adult male sex offenders, who were referred for ADT to the endocrine outpatient clinic, received cyproterone acetate. Changes in blood markers of calcium/phosphate homeostasis and bone turnover between baseline and first follow-up visit were studied. Results: Of 26 screened patients, 17 were included. The median age was 44 (range 20-75) years. The median time interval between baseline and first follow-up was 13 (6-27) weeks. Compared to baseline, an 81% decrease was observed for median total testosterone (to 3.4 nmol/L (0.4-12.2); P<0.0001) and free testosterone (to 0.06 nmol/L (0.01-0.18); P<0.0001). Median total estradiol decreased 71% (to 17.6 pmol/L (4.7-35.6); P<0.0001). Increased serum calcium (P<0.0001) and phosphate (P=0.0016) was observed, paralleled by decreased PTH (P=0.0156) and 1,25 dihydroxyvitamin D3 (P=0.0134). The stable calcium isotope ratio (δ44/42Ca) decreased (P=0.0458), indicating net calcium loss from bone. Bone-specific alkaline phosphatase and osteocalcin decreased (P<0.0001 and P=0.0056, respectively), periostin tended to decrease (P=0.0500) whereas sclerostin increased (P<0.0001), indicating suppressed bone formation. Serum bone resorption markers (TRAcP5b, CTX) were unaltered. Conclusions: In adult men, calcium release from the skeleton occurs early following sex steroid deprivation, reflecting early bone resorption. The increase of sclerostin and reduction of bone formation markers, without changes in resorption markers, suggests a dominant negative effect on bone formation in the acute phase

    Iteratively regularized Newton-type methods for general data misfit functionals and applications to Poisson data

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    We study Newton type methods for inverse problems described by nonlinear operator equations F(u)=gF(u)=g in Banach spaces where the Newton equations F(un;un+1un)=gF(un)F'(u_n;u_{n+1}-u_n) = g-F(u_n) are regularized variationally using a general data misfit functional and a convex regularization term. This generalizes the well-known iteratively regularized Gauss-Newton method (IRGNM). We prove convergence and convergence rates as the noise level tends to 0 both for an a priori stopping rule and for a Lepski{\u\i}-type a posteriori stopping rule. Our analysis includes previous order optimal convergence rate results for the IRGNM as special cases. The main focus of this paper is on inverse problems with Poisson data where the natural data misfit functional is given by the Kullback-Leibler divergence. Two examples of such problems are discussed in detail: an inverse obstacle scattering problem with amplitude data of the far-field pattern and a phase retrieval problem. The performence of the proposed method for these problems is illustrated in numerical examples

    FRA2A is a CGG repeat expansion associated with silencing of AFF3

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    Folate-sensitive fragile sites (FSFS) are a rare cytogenetically visible subset of dynamic mutations. Of the eight molecularly characterized FSFS, four are associated with intellectual disability (ID). Cytogenetic expression results from CGG tri-nucleotide-repeat expansion mutation associated with local CpG hypermethylation and transcriptional silencing. The best studied is the FRAXA site in the FMR1 gene, where large expansions cause fragile X syndrome, the most common inherited ID syndrome. Here we studied three families with FRA2A expression at 2q11 associated with a wide spectrum of neurodevelopmental phenotypes. We identified a polymorphic CGG repeat in a conserved, brain-active alternative promoter of the AFF3 gene, an autosomal homolog of the X-linked AFF2/FMR2 gene: Expansion of the AFF2 CGG repeat causes FRAXE ID. We found that FRA2A-expressing individuals have mosaic expansions of the AFF3 CGG repeat in the range of several hundred repeat units. Moreover, bisulfite sequencing and pyrosequencing both suggest AFF3 promoter hypermethylation. cSNP-analysis demonstrates monoallelic expression of the AFF3 gene in FRA2A carriers thus predicting that FRA2A expression results in functional haploinsufficiency for AFF3 at least in a subset of tissues. By whole-mount in situ hybridization the mouse AFF3 ortholog shows strong regional expression in the developing brain, somites and limb buds in 9.5-12.5dpc mouse embryos. Our data suggest that there may be an association between FRA2A and a delay in the acquisition of motor and language skills in the families studied here. However, additional cases are required to firmly establish a causal relationship

    Secret seducers - True tales of pimps in the red light district of Amsterdam

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    At the end of the 1990s, a moral panic erupted in the Netherlands about the phenomenon of what came to be known as 'loverboys'. The suspicion was that a growing number of Dutch girls were being groomed by handsome young men who employed all sorts of devious methods to prepare their girlfriends for life as a prostitute. Stories about a new generation of pimps, often of Moroccan origin, regularly appeared in the Dutch media. In this article, based on ethnographic fieldwork on pimps operating in the red-light district of Amsterdam, we describe the ways in which these young men operate and how they justify their behaviour. On the basis of empirical research we intend to present a more realistic picture of what goes on in the prostitution industry and highlight the discrepancy between what is reported in the media and what is actually happening in the prostitution sector. We also examine the background to the moral panic about loverboys and the ways in which these young men were supposedly able to induce many young girls into becoming prostitutes

    Validation of a perioperative population factor VIII pharmacokinetic model with a large cohort of pediatric hemophilia a patients

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    AIMS: Population pharmacokinetic (PK) models are increasingly applied to perform individualized dosing of factor VIII (FVIII) concentrates in haemophilia A patients. To guarantee accurate performance of a population PK model in dose individualization, validation studies are of importance. However, external validation of population PK models requires independent data sets and is, therefore, seldomly performed. Therefore, this study aimed to validate a previously published population PK model for FVIII concentrates administrated perioperatively. METHODS: A previously published population PK model for FVIII concentrate during surgery was validated using independent data from 87 children with severe haemophilia A with a median (range) age of 2.6 years (0.03–15.2) and body weight of 14 kg (4–57). First, the predictive performance of the previous model was evaluated with MAP Bayesian analysis using NONMEM v7.4. Subsequently, the model parameters were (re)estimated using a combined dataset consisting of the previous modelling data and the data available for the external validation. RESULTS: The previous model underpredicted the measured FVIII levels with a median of 0.17 IU mL(−1). Combining the new, independent and original data, a dataset comprising 206 patients with a mean age of 7.8 years (0.03–77.6) and body weight of 30 kg (4–111) was obtained. Population PK modelling provided estimates for CL, V1, V2, and Q: 171 mL h(−1) 68 kg(−1), 2930 mL 68 kg(−1), 1810 mL 68 kg(−1), and 172 mL h(−1) 68 kg(−1), respectively. This model adequately described all collected FVIII levels, with a slight median overprediction of 0.02 IU mL(−1). CONCLUSIONS: This study emphasizes the importance of external validation of population PK models using real‐life data

    Verifying 4D gated radiotherapy using time-integrated electronic portal imaging: a phantom and clinical study

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    <p>Abstract</p> <p>Background</p> <p>Respiration-gated radiotherapy (RGRT) can decrease treatment toxicity by allowing for smaller treatment volumes for mobile tumors. RGRT is commonly performed using external surrogates of tumor motion. We describe the use of time-integrated electronic portal imaging (TI-EPI) to verify the position of internal structures during RGRT delivery</p> <p>Methods</p> <p>TI-EPI portals were generated by continuously collecting exit dose data (aSi500 EPID, Portal vision, Varian Medical Systems) when a respiratory motion phantom was irradiated during expiration, inspiration and free breathing phases. RGRT was delivered using the Varian RPM system, and grey value profile plots over a fixed trajectory were used to study object positions. Time-related positional information was derived by subtracting grey values from TI-EPI portals sharing the pixel matrix. TI-EPI portals were also collected in 2 patients undergoing RPM-triggered RGRT for a lung and hepatic tumor (with fiducial markers), and corresponding planning 4-dimensional CT (4DCT) scans were analyzed for motion amplitude.</p> <p>Results</p> <p>Integral grey values of phantom TI-EPI portals correlated well with mean object position in all respiratory phases. Cranio-caudal motion of internal structures ranged from 17.5–20.0 mm on planning 4DCT scans. TI-EPI of bronchial images reproduced with a mean value of 5.3 mm (1 SD 3.0 mm) located cranial to planned position. Mean hepatic fiducial markers reproduced with 3.2 mm (SD 2.2 mm) caudal to planned position. After bony alignment to exclude set-up errors, mean displacement in the two structures was 2.8 mm and 1.4 mm, respectively, and corresponding reproducibility in anatomy improved to 1.6 mm (1 SD).</p> <p>Conclusion</p> <p>TI-EPI appears to be a promising method for verifying delivery of RGRT. The RPM system was a good indirect surrogate of internal anatomy, but use of TI-EPI allowed for a direct link between anatomy and breathing patterns.</p

    In Vivo MR Imaging of Magnetically Labeled Mesenchymal Stem Cells in a Rat Model of Renal Ischemia

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    Objective: This study was designed to evaluate in vivo MR imaging for the depiction of intraarterially injected superparamagnetic iron oxide (SPIO)-labeled mesenchymal stem cells (MSCs) in an experimental rat model of renal ischemia. Materials and Methods: Left renal ischemia was induced in 12 male Sprague-Dawley rats by use of the catheter lodging method. In vivo MR signal intensity variations depicted on T2*-weighted sequences were evaluated in both the left and right kidneys prior to injection (n = 2), two hours (n = 4), 15 hours (n = 2), 30 hours (n = 2) and 72 hours (n = 2) after injection of SPIO-labeled MSCs in both kidneys. Signal intensity variations were correlated with the number of Prussian blue stain-positive cells as visualized in histological specimens. Results: In an in vivo study, it was determined that there was a significant difference in signal intensity variation for both the left and right cortex (40.8 +/- 4.12 and 26.4 +/- 7.92, respectively) and for both the left and right medulla (23.2 +/- 3.32 and 15.2 +/- 3.31, respectively) until two hours after injection (p < 0.05). In addition, signal intensity variation in the left renal cortex was well correlated with the number of Prussian blue stain-positive cells per high power field (r = 0.98, p < 0.05). Conclusion: Intraarterial injected SPIO-labeled MSCs in an experimental rat model of renal ischemia can be detected with the use of in vivo MR imaging immediately after injection.This study was partly supported by a grant from the Seoul Research and Business Development Program 10548 and by a grant (A062260) from the Innovative Research Institute for Cell Therapy, Republic of Korea.Ittrich H, 2007, J MAGN RESON IMAGING, V25, P1179, DOI 10.1002/jmri.20925Hauger O, 2006, RADIOLOGY, V238, P200, DOI 10.1148/radiol.2381041668Togel F, 2005, AM J PHYSIOL-RENAL, V289, pF31, DOI 10.1152/ajprenal.00007.2005Bos C, 2004, RADIOLOGY, V233, P781, DOI 10.1148/radiol.2333031714Bulte JWM, 2004, NMR BIOMED, V17, P484, DOI 10.1002/nbm.924Grove JE, 2004, STEM CELLS, V22, P487Herzog EL, 2003, BLOOD, V102, P3483, DOI 10.1182/blood-2003-05-1664Kalish H, 2003, MAGNET RESON MED, V50, P275, DOI 10.1002/mrm.10556Frank JA, 2003, RADIOLOGY, V228, P480, DOI 10.1148/radiol.2281020638Jo SK, 2003, KIDNEY INT, V64, P43Kale S, 2003, J CLIN INVEST, V112, P42, DOI 10.1172/JCI200317856Bulte JWM, 2003, MAGNET RESON MED, V50, P201, DOI 10.1002/mrm.10511Kraitchman DL, 2003, CIRCULATION, V107, P2290, DOI 10.1161/01.CIR.0000070931.62772.4EGupta S, 2002, KIDNEY INT, V62, P1285Krause DS, 2002, GENE THER, V9, P754Bulte JWM, 2001, NAT BIOTECHNOL, V19, P1141Lewin M, 2000, NAT BIOTECHNOL, V18, P410Kelly KJ, 2000, SEMIN NEPHROL, V20, P4Firbank MJ, 1999, PHYS MED BIOL, V44, pN261, DOI 10.1088/0031-9155/44/12/403Josephson L, 1999, BIOCONJUGATE CHEM, V10, P186Sutton TA, 1998, SEMIN NEPHROL, V18, P490Thadhani R, 1996, NEW ENGL J MED, V334, P1448SHANLEY PF, 1986, AM J PATHOL, V122, P462
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