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Sample records for tgf-beta3 induced chondrogenesis

  1. TGF-beta3 is expressed in taste buds and inhibits proliferation of primary cultured taste epithelial cells.

    Science.gov (United States)

    Nakamura, Shin-ichi; Kawai, Takayuki; Kamakura, Takashi; Ookura, Tetsuya

    2010-01-01

    Transforming growth factor-betas (TGF-betas), expressed in various tissues, play important roles in embryonic development and adult tissue homeostasis through their effects on cell proliferation, cell differentiation, cell death, and cell motility. However, expression of TGF-beta signaling components and their biological effect on taste epithelia has not been elucidated. We performed expression analysis of TGF-beta signaling components in taste epithelia and found that the TGF-beta3 mRNA was specifically expressed in taste buds. Type II TGF-betas receptor (TbetaR-II) mRNA was specifically expressed in the tongue epithelia including the taste epithelia. To elucidate the biological function of TGF-beta3 in taste epithelia, we performed proliferation assay with primary cultured taste epithelial cells. In the presence of TGF-beta3, percentage of BrdU-labeled cells decreased significantly, suggesting that the TGF-beta3 inhibited the proliferation of cultured taste epithelial cells through inhibiting cell-cycle entry into S phase. By quantitative reverse transcription-polymerase chain reaction assay, we found that the TGF-beta3 resulted in an increased level of expression of p15Ink4b and p21Cip1, suggesting that the TGF-beta3 inhibited the taste epithelial cell proliferation through inhibiting G1cyclin-Cdk complexes. Taken together, these results suggested that the TGF-beta3 may regulate taste epithelial cell homeostasis through controlling cell proliferation.

  2. Chondrogenesis of synovium-derived mesenchymal stem cells in gene-transferred co-culture system.

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    Varshney, Rohan R; Zhou, Ruijie; Hao, Jinghua; Yeo, Suan Siong; Chooi, Wai Hon; Fan, Jiabing; Wang, Dong-An

    2010-09-01

    A co-culture strategy has been developed in this study wherein rabbit synovial mesenchymal stem cells (SMSCs) are co-cultured with growth factor (GF) transfected articular chondrocytes. Toward this end, both SMSCs and early passage rabbit articular chondrocytes that had been adenovirally transduced with transforming growth factor-beta 3 (TGF-beta3) gene were separately encapsulated in alginate beads and co-cultured in the same pool of chondrogenic medium. The chondrocytes act as transfected companion cells (TCCs) providing GF supply to induce chondrogenic differentiation of SMSCs that play the role of therapeutic progenitor cells (TPCs). Against the same TCC based TGF-beta3 release profile, the co-culture was started at different time points (Day 0, Day 10 and Day 20) but made to last for identical periods of exposure (30 days) so that the exposure conditions could be optimized in terms of initiation and duration. Transfection of TCCs prevents the stem cell based TPCs from undergoing the invasive procedure. It also prevents unpredictable complications in the TPCs caused by long-term constitutive over-expression of a GF. The adenovirally transfected TCCs exhibit a transient GF expression which results in a timely termination of GF supply to the TPCs. The TCC-sourced transgenic TGF-beta3 successfully induced chondrogenesis in the TPCs. Real-time PCR results show enhanced expression of cartilage markers and immuno/histochemical staining for Glycosaminoglycans (GAG) and Collagen II also shows abundant extracellular matrix (ECM) production and chondrogenic morphogenesis in the co-cultured TPCs. These results confirm the efficacy of directing stem cell differentiation towards chondrogenesis and cartilage tissue formation by co-culturing them with GF transfected chondrocytes.

  3. Cytomegalovirus induces abnormal chondrogenesis and osteogenesis during embryonic mandibular development

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    Bringas Pablo

    2008-03-01

    Full Text Available Abstract Background Human clinical studies and mouse models clearly demonstrate that cytomegalovirus (CMV disrupts normal organ and tissue development. Although CMV is one of the most common causes of major birth defects in humans, little is presently known about the mechanism(s underlying CMV-induced congenital malformations. Our prior studies have demonstrated that CMV infection of first branchial arch derivatives (salivary glands and teeth induced severely abnormal phenotypes and that CMV has a particular tropism for neural crest-derived mesenchyme (NCM. Since early embryos are barely susceptible to CMV infection, and the extant evidence suggests that the differentiation program needs to be well underway for embryonic tissues to be susceptible to viral infection and viral-induced pathology, the aim of this study was to determine if first branchial arch NCM cells are susceptible to mCMV infection prior to differentiation of NCM derivatives. Results E11 mouse mandibular processes (MANs were infected with mouse CMV (mCMV for up to 16 days in vitro. mCMV infection of undifferentiated embryonic mouse MANs induced micrognathia consequent to decreased Meckel's cartilage chondrogenesis and mandibular osteogenesis. Specifically, mCMV infection resulted in aberrant stromal cellularity, a smaller, misshapen Meckel's cartilage, and mandibular bone and condylar dysmorphogenesis. Analysis of viral distribution indicates that mCMV primarily infects NCM cells and derivatives. Initial localization studies indicate that mCMV infection changed the cell-specific expression of FN, NF-κB2, RelA, RelB, and Shh and Smad7 proteins. Conclusion Our results indicate that mCMV dysregulation of key signaling pathways in primarily NCM cells and their derivatives severely disrupts mandibular morphogenesis and skeletogenesis. The pathogenesis appears to be centered around the canonical and noncanonical NF-κB pathways, and there is unusual juxtaposition of abnormal stromal

  4. Hypoxic treatment inhibits insulin-induced chondrogenesis of ATDC5 cells despite upregulation of DEC1

    DEFF Research Database (Denmark)

    Chen, Li; Fink, Trine; Ebbesen, Peter

    2006-01-01

    Chondrogenesis occurs in vivo in a hypoxic environment, in which the hypoxia inducible factor 1, HIF-1, plays a regulatory role, possibly mediated through the transcription factor DEC1. We have analyzed the effect of hypoxia (1% oxygen) alone and in combination with insulin on the chondrogenic di...

  5. Molecular mechanism of hypoxia-induced chondrogenesis and its application in in vivo cartilage tissue engineering.

    Science.gov (United States)

    Duval, Elise; Baugé, Catherine; Andriamanalijaona, Rina; Bénateau, Hervé; Leclercq, Sylvain; Dutoit, Soizic; Poulain, Laurent; Galéra, Philippe; Boumédiene, Karim

    2012-09-01

    Cartilage engineering is one of the most challenging issue in regenerative medicine, due to its limited self-ability to repair. Here, we assessed engineering of cartilage tissue starting from human bone marrow (hBM) stem cells under hypoxic environment and delineated the mechanism whereby chondrogenesis could be conducted without addition of exogenous growth factors. hBM stem cells were cultured in alginate beads and chondrogenesis was monitored by chondrocyte phenotypic markers. Activities and roles of Sox and HIF-1α transcription factors were investigated with complementary approaches of gain and loss of function and provided evidences that HIF-1α is essential for hypoxic induction of chondrogenesis. Thereafter, hBM cells and human articular chondrocytes (HAC) underwent chondrogenesis by 3D and hypoxic culture for 7 days or by ectopic expression of HIF-1α. After subcutaneous implantation of 3 weeks into athymic mice, tissue analysis showed that hypoxia or HIF-1α overexpression is effective and sufficient to induce chondrocyte phenotype in hBM cells, without use of exogenous growth factors. Therefore, this study brings interesting data for a simple and affordable system in biotechnology of cartilage engineering. Copyright © 2012 Elsevier Ltd. All rights reserved.

  6. Synthetic triterpenoids, CDDO-Imidazolide and CDDO-Ethyl amide, induce chondrogenesis.

    Science.gov (United States)

    Suh, N; Paul, S; Lee, H J; Yoon, T; Shah, N; Son, A I; Reddi, A H; Medici, D; Sporn, M B

    2012-05-01

    Novel methods for inducing chondrogenesis are critical for cartilage tissue engineering and regeneration. Here we show that the synthetic oleanane triterpenoids, CDDO-Imidazolide (CDDO-Im) and CDDO-Ethyl amide (CDDO-EA), at concentrations as low as 200 nM, induce chondrogenesis in organ cultures of newborn mouse calvaria. The cartilage phenotype was measured histologically with metachromatic toluidine blue staining for proteoglycans and by immunohistochemical staining for type II collagen. Furthermore, real-time polymerase chain reaction (PCR) analysis using mRNA from calvaria after 7-day treatment with CDDO-Im and CDDO-EA showed up-regulation of the chondrocyte markers SOX9 and type II collagen (alpha1). In addition, TGF-β; BMPs 2 and 4; Smads 3, 4, 6, and 7; and TIMPs-1 and -2 were increased. In contrast, MMP-9 was strongly down-regulated. Treatment of human bone marrow-derived mesenchymal stem cells with CDDO-Im and CDDO-EA (100 nM) induced expression of SOX9, collagen IIα1, and aggrecan, as well as BMP-2 and phospho-Smad5, confirming that the above triterpenoids induce chondrogenic differentiation. This is the first report of the use of these drugs for induction of chondrogenesis. Copyright © 2012 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

  7. Lead induces chondrogenesis and alters transforming growth factor-beta and bone morphogenetic protein signaling in mesenchymal cell populations.

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    Zuscik, Michael J; Ma, Lin; Buckley, Taylor; Puzas, J Edward; Drissi, Hicham; Schwarz, Edward M; O'Keefe, Regis J

    2007-09-01

    It has been established that skeletal growth is stunted in lead-exposed children. Because chondrogenesis is a seminal step during skeletal development, elucidating the impact of Pb on this process is the first step toward understanding the mechanism of Pb toxicity in the skeleton. The aim of this study was to test the hypothesis that Pb alters chondrogenic commitment of mesenchymal cells and to assess the effects of Pb on various signaling pathways. We assessed the influence of Pb on chondrogenesis in murine limb bud mesenchymal cells (MSCs) using nodule formation assays and gene analyses. The effects of Pb on transforming growth factor-beta (TGF-beta) and bone morphogenetic protein (BMP) signaling was studied using luciferase-based reporters and Western analyses, and luciferase-based assays were used to study cyclic adenosine monophosphate response element binding protein (CREB), beta-catenin, AP-1, and nuclear factor-kappa B (NF-kappaB) signaling. We also used an ectopic bone formation assay to determine how Pb affects chondrogenesis in vivo. Pb-exposed MSCs showed enhanced basal and TGF-beta/BMP induction of chondrogenesis, evidenced by enhanced nodule formation and up-regulation of Sox-9, type 2 collagen, and aggrecan, all key markers of chondrogenesis. We observed enhanced chondrogenesis during ectopic bone formation in mice preexposed to Pb via drinking water. In MSCs, Pb enhanced TGF-beta but inhibited BMP-2 signaling, as measured by luciferase reporter assays and Western analyses of Smad phosphorylation. Although Pb had no effect on basal CREB or Wnt/beta-catenin pathway activity, it induced NFkappaB signaling and inhibited AP-1 signaling. The in vitro and in vivo induction of chondrogenesis by Pb likely involves modulation and integration of multiple signaling pathways including TGF-beta, BMP, AP-1, and NFkappaB.

  8. Kaempferol induces chondrogenesis in ATDC5 cells through activation of ERK/BMP-2 signaling pathway.

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    Nepal, Manoj; Li, Liang; Cho, Hyoung Kwon; Park, Jong Kun; Soh, Yunjo

    2013-12-01

    Endochondral bone formation occurs when mesenchymal cells condense to differentiate into chondrocytes, the primary cell types of cartilage. The aim of the present study was to identify novel factors regulating chondrogenesis. We investigated whether kaempferol induces chondrogenic differentiation in clonal mouse chondrogenic ATDC5 cells. Kaempferol treatment stimulated the accumulation of cartilage nodules in a dose-dependent manner. Kaempferol-treated ATDC5 cells stained more intensely with alcian blue staining than control cells, suggesting greater synthesis of matrix proteoglycans in the kaempferol-treated cells. Similarly, kaempferol induced greater activation of alkaline phosphatase activity than control cells, and it enhanced the expression of chondrogenic marker genes, such as collagen type I, collagen type X, OCN, Runx2, and Sox9. Kaempferol induced an acute activation of extracellular signal-regulated kinase (ERK) but not c-jun N-terminal kinase or p38 MAP kinase. PD98059, an inhibitor of MAPK/ERK, decreased in stained cells treated with kaempferol. Furthermore, kaempferol greatly expressed the protein and mRNA levels of BMP-2, suggesting chondrogenesis was stimulated via a BMP-2 pathway. Taken together, our results suggest that kaempferol has chondromodulating effects via an ERK/BMP-2 signaling pathway and could potentially be used as a therapeutic agent for bone growth disorders. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. Influence of three-dimensional hyaluronic acid microenvironments on mesenchymal stem cell chondrogenesis.

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    Chung, Cindy; Burdick, Jason A

    2009-02-01

    Mesenchymal stem cells (MSCs) are multipotent progenitor cells whose plasticity and self-renewal capacity have generated significant interest for applications in tissue engineering. The objective of this study was to investigate MSC chondrogenesis in photo-cross-linked hyaluronic acid (HA) hydrogels. Because HA is a native component of cartilage, and MSCs may interact with HA via cell surface receptors, these hydrogels could influence stem cell differentiation. In vitro and in vivo cultures of MSC-laden HA hydrogels permitted chondrogenesis, measured by the early gene expression and production of cartilage-specific matrix proteins. For in vivo culture, MSCs were encapsulated with and without transforming growth factor beta-3 (TGF-beta3) or pre-cultured for 2 weeks in chondrogenic medium before implantation. Up-regulation of type II collagen, aggrecan, and sox 9 was observed for all groups over MSCs at the time of encapsulation, and the addition of TGF-beta3 further enhanced the expression of these genes. To assess the influence of scaffold chemistry on chondrogenesis, HA hydrogels were compared with relatively inert poly(ethylene glycol) (PEG) hydrogels and showed enhanced expression of cartilage-specific markers. Differences between HA and PEG hydrogels in vivo were most noticeable for MSCs and polymer alone, indicating that hydrogel chemistry influences the commitment of MSCs to undergo chondrogenesis (e.g., approximately 43-fold up-regulation of type II collagen of MSCs in HA over PEG hydrogels). Although this study investigated only early markers of tissue regeneration, these results emphasize the importance of material cues in MSC differentiation microenvironments, potentially through interactions between scaffold materials and cell surface receptors.

  10. Cyclic compression maintains viability and induces chondrogenesis of human mesenchymal stem cells in fibrin gel scaffolds.

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    Pelaez, Daniel; Huang, Chun-Yuh Charles; Cheung, Herman S

    2009-01-01

    Mechanical loading has long been shown to modulate cartilage-specific extracellular matrix synthesis. With joint motion, cartilage can experience mechanical loading in the form of compressive, tensile or shearing load, and hydrostatic pressure. Recent studies have demonstrated the capacity of unconfined cyclic compression to induce chondrogenic differentiation of human mesenchymal stem cell (hMSC) in agarose culture. However, the use of a nonbiodegradable material such as agarose limits the applicability of these constructs. Of the possible biocompatible materials available for tissue engineering, fibrin is a natural regenerative scaffold, which possesses several desired characteristics including a controllable degradation rate and low immunogenicity. The objective of the present study was to determine the capability of fibrin gels for supporting chondrogenesis of hMSCs under cyclic compression. To optimize the system, three concentrations of fibrin gel (40, 60, and 80 mg/mL) and three different stimulus frequencies (0.1, 0.5, and 1.0 Hz) were used to examine the effects of cyclic compression on viability, proliferation and chondrogenic differentiation of hMSCs. Our results show that cyclic compression (10% strain) at frequencies >0.5 Hz and gel concentration of 40 mg/mL fibrinogen appears to maintain cellular viability within scaffolds. Similarly, variations in gel component concentration and stimulus frequency can be modified such that a significant chondrogenic response can be achieved by hMSC in fibrin constructs after 8 h of compression spread out over 2 days. This study demonstrates the suitability of fibrin gel for supporting the cyclic compression-induced chondrogenesis of mesenchymal stem cells.

  11. Expression of transforming growth factor beta (TGF beta) receptors and expression of TGF beta 1, TGF beta 2 and TGF beta 3 in human small cell lung cancer cell lines

    DEFF Research Database (Denmark)

    Damstrup, L; Rygaard, K; Spang-Thomsen, M

    1993-01-01

    A panel of 21 small cell lung cancer cell (SCLC) lines were examined for the presence of Transforming growth factor beta receptors (TGF beta-r) and the expression of TGF beta mRNAs. By the radioreceptor assay we found high affinity receptors to be expressed in six cell lines. scatchard analysis......(r) = 65,000 and 90,000 and the betaglycan (type III) with M(r) = 280,000. Northern blotting showed expression of TGF beta 1 mRNA in ten, TGF beta 2 mRNA in two and TGF beta 3 mRNA in seven cell lines. Our results provide, for the first time, evidence that a large proportion of a broad panel of SCLC cell...... lines express TGF beta-receptors and also produce TGF beta mRNAs....

  12. In vitro chondrogenesis and in vivo repair of osteochondral defect with human induced pluripotent stem cells.

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    Ko, Ji-Yun; Kim, Kyung-Il; Park, Siyeon; Im, Gun-Il

    2014-04-01

    The purpose of this study was to investigate the chondrogenic features of human induced pluripotent stem cells (hiPSCs) and examine the differences in the chondrogenesis between hiPSCs and human bone marrow-derived MSCs (hBMMSCs). Embryoid bodies (EBs) were formed from undifferentiated hiPSCs. After EBs were dissociated into single cells, chondrogenic culture was performed in pellets and alginate hydrogel. Chondro-induced hiPSCs were implanted in osteochondral defects created on the patellar groove of immunosuppressed rats and evaluated after 12 weeks. The ESC markers NANOG, SSEA4 and OCT3/4 disappeared while the mesodermal marker BMP-4 appeared in chondro-induced hiPSCs. After 21 days of culture, greater glycosaminoglycan contents and better chondrocytic features including lacuna and abundant matrix formation were observed from chondro-induced hiPSCs compared to chondro-induced hBMMSCs. The expression of chondrogenic markers including SOX-9, type II collagen, and aggrecan in chondro-induced hiPSCs was comparable to or greater than chondro-induced hBMMSCs. A remarkably low level of hypertrophic and osteogenic markers including type X collagen, type I collagen and Runx-2 was noted in chondro-induced hiPSCs compared to chondro-induced hBMMSCs. hiPSCs had significantly greater methylation of several CpG sites in COL10A1 promoter than hBMMSCs in either undifferentiated or chondro-induced state, suggesting an epigenetic cause of the difference in hypertrophy. The defects implanted with chondro-induced hiPSCs showed a significantly better quality of cartilage repair than the control defects, and the majority of cells in the regenerated cartilage consisted of implanted hiPSCs. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Molecular mechanism of hypoxia-induced chondrogenesis and its application in in vivo cartilage tissue engineering.

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    Duval , Elise; Baugé , Catherine; Andriamanalijaona , Rina; Bénateau , Hervé; Leclercq , Sylvain; Dutoit , Soizic; Poulain , Laurent; Galéra , Philippe; Boumédiene , Karim

    2012-01-01

    International audience; Cartilage engineering is one of the most challenging issue in regenerative medicine, due to its limited self-ability to repair. Here, we assessed engineering of cartilage tissue starting from human bone marrow (hBM) stem cells under hypoxic environment and delineated the mechanism whereby chondrogenesis could be conducted without addition of exogenous growth factors. hBM stem cells were cultured in alginate beads and chondrogenesis was monitored by chondrocyte phenotyp...

  14. Autologous Matrix-Induced Chondrogenesis: A Systematic Review of the Clinical Evidence.

    Science.gov (United States)

    Gao, Liang; Orth, Patrick; Cucchiarini, Magali; Madry, Henning

    2017-11-01

    The addition of a type I/III collagen membrane in cartilage defects treated with microfracture has been advocated for cartilage repair, termed "autologous matrix-induced chondrogenesis" (AMIC). To examine the current clinical evidence regarding AMIC for focal chondral defects. Systematic review. A systematic review was performed by searching PubMed, ScienceDirect, and Cochrane Library databases. Inclusion criteria were clinical studies of AMIC for articular cartilage repair, written in English. Relative data were extracted and critically analyzed. PRISMA guidelines were applied, the methodological quality of the included studies was assessed by the modified Coleman Methodology Score (CMS), and aggregate data were generated. Twenty-eight clinical articles were included: 12 studies (245 patients) of knee cartilage defects, 12 studies (214 patients) of ankle cartilage defects, and 4 studies (308 patients) of hip cartilage defects. The CMS demonstrated a suboptimal study design in the majority of published studies (knee, 57.8; ankle, 55.3; hip, 57.7). For the knee, 1 study reported significant clinical improvements for AMIC compared with microfracture for medium-sized cartilage defects (mean defect size 3.6 cm 2 ) after 5 years (level of evidence, 1). No study compared AMIC with matrix-assisted autologous chondrocyte implantation (ACI) in the knee. For the ankle, no clinical trial was available comparing AMIC versus microfracture or ACI. In the hip, only one analysis (level of evidence, 3) compared AMIC with microfracture for acetabular lesions. For medium-sized acetabular defects, one study (level of evidence, 3) found no significant differences between AMIC and ACI at 5 years. Specific aspects not appropriately discussed in the currently available literature include patient-related factors, membrane fixation, and defect properties. No treatment-related adverse events were reported. This systematic review reveals a paucity of high-quality, randomized controlled

  15. Histone deacetylase 4 promotes TGF-beta1-induced synovium-derived stem cell chondrogenesis but inhibits chondrogenically differentiated stem cell hypertrophy.

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    Pei, Ming; Chen, Demeng; Li, Jingting; Wei, Lei

    2009-12-01

    The transforming growth factor-beta (TGF-beta) superfamily members play diverse roles in cartilage development and maintenance. TGF-beta up-regulates chondrogenic gene expression by enhancing transcription factor SRY (sex determining region Y)-box 9 (Sox9) and inhibits osteoblast differentiation by repressing runt-related transcription factor 2 (Runx2). Recently, histone deacetylases (HDACs) were reported to act as negative regulators of chondrocyte hypertrophy. It was speculated that HDAC4 may promote TGF-beta1-induced MSC chondrogenesis. In this study, the adenovirus-mediated HDAC4 gene (Ad.HDAC4) was utilized to infect synovium-derived stem cells (SDSCs). Adenovirus-mediated LacZ (Ad.LacZ) served as a control. The infected cells were centrifuged to form SDSC pellets followed by incubation in a serum-free chondrogenic medium for 15 days with or without 10ng/mL TGF-beta1. Transfection efficiency was determined in SDSCs using Ad.LacZ. Cytotoxicity was measured using lactate dehydrogenase assay. Histology, immunostaining, biochemical analysis, and real-time polymerase chain reaction were performed to assess chondrogenesis at protein and mRNA levels in infected SDSCs. Our data demonstrated that supplementation with TGF-beta1 could initiate and promote SDSC chondrogenesis; however, TGF-beta1 alone was insufficient to fully differentiate SDSCs into chondrocytes. Ad.HDAC4 could be efficiently transfected into SDSCs. Without TGF-beta1 treatment, HDAC4 had no effect on SDSC chondrogenesis; however, in the presence of TGF-beta1, HDAC4 could speed up and maintain a high level of chondrogenesis while down-regulating the hypertrophic marker - type X collagen expression. This study is the first report showing that HDAC4 overexpression promotes TGF-beta1-induced SDSC chondrogenesis but inhibits chondrogenically differentiated stem cell hypertrophy. The mechanism underlying this process needs further investigation.

  16. Nicotine-induced retardation of chondrogenesis through down-regulation of IGF-1 signaling pathway to inhibit matrix synthesis of growth plate chondrocytes in fetal rats

    International Nuclear Information System (INIS)

    Deng, Yu; Cao, Hong; Cu, Fenglong; Xu, Dan; Lei, Youying; Tan, Yang; Magdalou, Jacques; Wang, Hui; Chen, Liaobin

    2013-01-01

    Previous studies have confirmed that maternal tobacco smoking causes intrauterine growth retardation (IUGR) and skeletal growth retardation. Among a multitude of chemicals associated with cigarette smoking, nicotine is one of the leading candidates for causing low birth weights. However, the possible mechanism of delayed chondrogenesis by prenatal nicotine exposure remains unclear. We investigated the effects of nicotine on fetal growth plate chondrocytes in vivo and in vitro. Rats were given 2.0 mg/kg·d of nicotine subcutaneously from gestational days 11 to 20. Prenatal nicotine exposure increased the levels of fetal blood corticosterone and resulted in fetal skeletal growth retardation. Moreover, nicotine exposure induced the inhibition of matrix synthesis and down-regulation of insulin-like growth factor 1 (IGF-1) signaling in fetal growth plates. The effects of nicotine on growth plates were studied in vitro by exposing fetal growth plate chondrocytes to 0, 1, 10, or 100 μM of nicotine for 10 days. Nicotine inhibited matrix synthesis and down-regulated IGF-1 signaling in chondrocytes in a concentration-dependent manner. These results suggest that prenatal nicotine exposure induces delayed chondrogenesis and that the mechanism may involve the down-regulation of IGF-1 signaling and the inhibition of matrix synthesis by growth plate chondrocytes. The present study aids in the characterization of delayed chondrogenesis caused by prenatal nicotine exposure, which might suggest a candidate mechanism for intrauterine origins of osteoporosis and osteoarthritis. - Highlights: ► Prenatal nicotine-exposure could induce delayed chondrogenesis in fetal rats. ► Nicotine inhibits matrix synthesis of fetal growth plate chondrocytes. ► Nicotine inhibits IGF-1 signaling pathway in fetal growth plate chondrocytes

  17. Nicotine-induced retardation of chondrogenesis through down-regulation of IGF-1 signaling pathway to inhibit matrix synthesis of growth plate chondrocytes in fetal rats

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    Deng, Yu; Cao, Hong; Cu, Fenglong [Department of Orthopedic Surgery, Zhongnan Hospital of Wuhan University, Wuhan 430071 (China); Xu, Dan [Department of Pharmacology, Basic Medical School of Wuhan University, Wuhan 430071 (China); Research Center of Food and Drug Evaluation, Wuhan University, Wuhan 430071 (China); Lei, Youying [Department of Pharmacology, Basic Medical School of Wuhan University, Wuhan 430071 (China); Tan, Yang [Department of Orthopedic Surgery, Zhongnan Hospital of Wuhan University, Wuhan 430071 (China); Magdalou, Jacques [UMR 7561 CNRS-Nancy Université, Faculté de Médicine, Vandoeuvre-lès-Nancy (France); Wang, Hui [Department of Pharmacology, Basic Medical School of Wuhan University, Wuhan 430071 (China); Research Center of Food and Drug Evaluation, Wuhan University, Wuhan 430071 (China); Chen, Liaobin, E-mail: lbchen@whu.edu.cn [Department of Orthopedic Surgery, Zhongnan Hospital of Wuhan University, Wuhan 430071 (China)

    2013-05-15

    Previous studies have confirmed that maternal tobacco smoking causes intrauterine growth retardation (IUGR) and skeletal growth retardation. Among a multitude of chemicals associated with cigarette smoking, nicotine is one of the leading candidates for causing low birth weights. However, the possible mechanism of delayed chondrogenesis by prenatal nicotine exposure remains unclear. We investigated the effects of nicotine on fetal growth plate chondrocytes in vivo and in vitro. Rats were given 2.0 mg/kg·d of nicotine subcutaneously from gestational days 11 to 20. Prenatal nicotine exposure increased the levels of fetal blood corticosterone and resulted in fetal skeletal growth retardation. Moreover, nicotine exposure induced the inhibition of matrix synthesis and down-regulation of insulin-like growth factor 1 (IGF-1) signaling in fetal growth plates. The effects of nicotine on growth plates were studied in vitro by exposing fetal growth plate chondrocytes to 0, 1, 10, or 100 μM of nicotine for 10 days. Nicotine inhibited matrix synthesis and down-regulated IGF-1 signaling in chondrocytes in a concentration-dependent manner. These results suggest that prenatal nicotine exposure induces delayed chondrogenesis and that the mechanism may involve the down-regulation of IGF-1 signaling and the inhibition of matrix synthesis by growth plate chondrocytes. The present study aids in the characterization of delayed chondrogenesis caused by prenatal nicotine exposure, which might suggest a candidate mechanism for intrauterine origins of osteoporosis and osteoarthritis. - Highlights: ► Prenatal nicotine-exposure could induce delayed chondrogenesis in fetal rats. ► Nicotine inhibits matrix synthesis of fetal growth plate chondrocytes. ► Nicotine inhibits IGF-1 signaling pathway in fetal growth plate chondrocytes.

  18. The ERK5 and ERK1/2 signaling pathways play opposing regulatory roles during chondrogenesis of adult human bone marrow-derived multipotent progenitor cells.

    Science.gov (United States)

    Bobick, Brent E; Matsche, Alexander I; Chen, Faye H; Tuan, Rocky S

    2010-07-01

    Adult human bone marrow-derived multipotent progenitor cells (MPCs) are able to differentiate into a variety of specialized cell types, including chondrocytes, and are considered a promising candidate cell source for use in cartilage tissue engineering. In this study, we examined the regulation of MPC chondrogenesis by mitogen-activated protein kinases in an attempt to better understand how to generate hyaline cartilage in the laboratory that more closely resembles native tissue. Specifically, we employed the high-density pellet culture model system to assess the roles of ERK5 and ERK1/2 pathway signaling in MPC chondrogenesis. Western blotting revealed that high levels of ERK5 phosphorylation correlate with low levels of MPC chondrogenesis and that as TGF-beta 3-enhanced MPC chondrogenesis proceeds, phospho-ERK5 levels steadily decline. Conversely, levels of phospho-ERK1/2 paralleled the progression of MPC chondrogenesis. siRNA-mediated knockdown of ERK5 pathway components MEK5 and ERK5 resulted in increased MPC pellet mRNA transcript levels of the cartilage-characteristic marker genes SOX9, COL2A1, AGC, L-SOX5, and SOX6, as well as enhanced accumulation of SOX9 protein, collagen type II protein, and Alcian blue-stainable proteoglycan. In contrast, knockdown of ERK1/2 pathway members MEK1 and ERK1 decreased expression of all chondrogenic markers tested. Finally, overexpression of MEK5 and ERK5 also depressed MPC chondrogenesis, as indicated by diminished activity of a co-transfected collagen II promoter-luciferase reporter construct. In conclusion, our results suggest a novel role for the ERK5 pathway as an important negative regulator of adult human MPC chondrogenesis and illustrate that the ERK5 and ERK1/2 kinase cascades play opposing roles regulating MPC cartilage formation. (c) 2010 Wiley-Liss, Inc.

  19. Chondroitin sulfate microparticles modulate transforming growth factor-β1-induced chondrogenesis of human mesenchymal stem cell spheroids.

    Science.gov (United States)

    Goude, Melissa C; McDevitt, Todd C; Temenoff, Johnna S

    2014-01-01

    Mesenchymal stem cells (MSCs) have been previously explored as a part of cell-based therapies for the repair of damaged cartilage. Current MSC chondrogenic differentiation strategies employ large pellets; however, we have developed a technique to form small MSC aggregates (500-1,000 cells) that can reduce transport barriers while maintaining a multicellular structure analogous to cartilaginous condensations. The objective of this study was to examine the effects of incorporating chondroitin sulfate methacrylate (CSMA) microparticles (MPs) within small MSC spheroids cultured in the presence of transforming growth factor (TGF)-β1 on chondrogenesis. Spheroids with MPs induced earlier increases in collagen II and aggrecan gene expression (chondrogenic markers) than spheroids without MPs, although no large differences in immunostaining for these matrix molecules were observed by day 21 between these groups. Collagen I and X were also detected in the extracellular matrix (ECM) of all spheroids by immunostaining. Interestingly, histology revealed that CSMA MPs clustered together near the center of the MSC spheroids and induced circumferential alignment of cells and ECM around the material core. This study demonstrates the use of CSMA materials to further examine the effects of matrix molecules on MSC phenotype as well as potentially direct differentiation in a more spatially controlled manner that better mimics the architecture of specific musculoskeletal tissues. © 2014 S. Karger AG, Basel.

  20. Thyroid hormone-induced hypertrophy in mesenchymal stem cell chondrogenesis is mediated by bone morphogenetic protein-4.

    Science.gov (United States)

    Karl, Alexandra; Olbrich, Norman; Pfeifer, Christian; Berner, Arne; Zellner, Johannes; Kujat, Richard; Angele, Peter; Nerlich, Michael; Mueller, Michael B

    2014-01-01

    Chondrogenic differentiating mesenchymal stem cells (MSCs) express markers of hypertrophic growth plate chondrocytes. As hypertrophic cartilage undergoes ossification, this is a concern for the application of MSCs in articular cartilage tissue engineering. To identify mechanisms that elicit this phenomenon, we used an in vitro hypertrophy model of chondrifying MSCs for differential gene expression analysis and functional experiments with the focus on bone morphogenetic protein (BMP) signaling. Hypertrophy was induced in chondrogenic MSC pellet cultures by transforming growth factor β (TGFβ) and dexamethasone withdrawal and addition of triiodothyronine. Differential gene expression analysis of BMPs and their receptors was performed. Based on these results, the in vitro hypertrophy model was used to investigate the effect of recombinant BMP4 and the BMP inhibitor Noggin. The enhancement of hypertrophy could be shown clearly by an increased cell size, alkaline phosphatase activity, and collagen type X deposition. Upon induction of hypertrophy, BMP4 and the BMP receptor 1B were upregulated. Addition of BMP4 further enhanced hypertrophy in the absence, but not in the presence of TGFβ and dexamethasone. Thyroid hormone induced hypertrophy by upregulation of BMP4 and this induced enhancement of hypertrophy could be blocked by the BMP antagonist Noggin. BMP signaling is an important modulator of the late differentiation stages in MSC chondrogenesis and the thyroid hormone induces this pathway. As cartilage tissue engineering constructs will be exposed to this factor in vivo, this study provides important insight into the biology of MSC-based cartilage. Furthermore, the possibility to engineer hypertrophic cartilage may be helpful for critical bone defect repair.

  1. The effect of 3D nanofibrous scaffolds on the chondrogenesis of induced pluripotent stem cells and their application in restoration of cartilage defects.

    Science.gov (United States)

    Liu, Ji; Nie, Huarong; Xu, Zhengliang; Niu, Xin; Guo, Shangchun; Yin, Junhui; Guo, Fei; Li, Gang; Wang, Yang; Zhang, Changqing

    2014-01-01

    The discovery of induced pluripotent stem cells (iPSCs) rendered the reprogramming of terminally differentiated cells to primary stem cells with pluripotency possible and provided potential for the regeneration and restoration of cartilage defect. Chondrogenic differentiation of iPSCs is crucial for their application in cartilage tissue engineering. In this study we investigated the effect of 3D nanofibrous scaffolds on the chondrogenesis of iPSCs and articular cartilage defect restoration. Super-hydrophilic and durable mechanic polycaprolactone (PCL)/gelatin scaffolds were fabricated using two separate electrospinning processes. The morphological structure and mechanical properties of the scaffolds were characterized. The chondrogenesis of the iPSCs in vitro and the restoration of the cartilage defect was investigated using scanning electron microscopy (SEM), the Cell Counting Kit-8 (CCK-8), histological observation, RT-qPCR, and western blot analysis. iPSCs on the scaffolds expressed higher levels of chondrogenic markers than the control group. In an animal model, cartilage defects implanted with the scaffold-cell complex exhibited an enhanced gross appearance and histological improvements, higher cartilage-specific gene expression and protein levels, as well as subchondral bone regeneration. Therefore, we showed scaffolds with a 3D nanofibrous structure enhanced the chondrogenesis of iPSCs and that iPSC-containing scaffolds improved the restoration of cartilage defects to a greater degree than did scaffolds alone in vivo.

  2. The effect of 3D nanofibrous scaffolds on the chondrogenesis of induced pluripotent stem cells and their application in restoration of cartilage defects.

    Directory of Open Access Journals (Sweden)

    Ji Liu

    Full Text Available The discovery of induced pluripotent stem cells (iPSCs rendered the reprogramming of terminally differentiated cells to primary stem cells with pluripotency possible and provided potential for the regeneration and restoration of cartilage defect. Chondrogenic differentiation of iPSCs is crucial for their application in cartilage tissue engineering. In this study we investigated the effect of 3D nanofibrous scaffolds on the chondrogenesis of iPSCs and articular cartilage defect restoration. Super-hydrophilic and durable mechanic polycaprolactone (PCL/gelatin scaffolds were fabricated using two separate electrospinning processes. The morphological structure and mechanical properties of the scaffolds were characterized. The chondrogenesis of the iPSCs in vitro and the restoration of the cartilage defect was investigated using scanning electron microscopy (SEM, the Cell Counting Kit-8 (CCK-8, histological observation, RT-qPCR, and western blot analysis. iPSCs on the scaffolds expressed higher levels of chondrogenic markers than the control group. In an animal model, cartilage defects implanted with the scaffold-cell complex exhibited an enhanced gross appearance and histological improvements, higher cartilage-specific gene expression and protein levels, as well as subchondral bone regeneration. Therefore, we showed scaffolds with a 3D nanofibrous structure enhanced the chondrogenesis of iPSCs and that iPSC-containing scaffolds improved the restoration of cartilage defects to a greater degree than did scaffolds alone in vivo.

  3. Evaluation of Insulin Medium or Chondrogenic Medium on Proliferation and Chondrogenesis of ATDC5 Cells

    OpenAIRE

    Yao, Yongchang; Zhai, Zhichen; Wang, Yingjun

    2014-01-01

    Background. The ATDC5 cell line is regarded as an excellent cell model for chondrogenesis. In most studies with ATDC5 cells, insulin medium (IM) was used to induce chondrogenesis while chondrogenic medium (CM), which was usually applied in chondrogenesis of mesenchymal stem cells (MSCs), was rarely used for ATDC5 cells. This study was mainly designed to investigate the effect of IM, CM, and growth medium (GM) on chondrogenesis of ATDC5 cells. Methods. ATDC5 cells were, respectively, cultured ...

  4. PLGA-based microcarriers induce mesenchymal stem cell chondrogenesis and stimulate cartilage repair in osteoarthritis.

    Science.gov (United States)

    Morille, Marie; Toupet, Karine; Montero-Menei, Claudia N; Jorgensen, Christian; Noël, Danièle

    2016-05-01

    In the present study, we aimed at evaluating the ability of novel PLGA-P188-PLGA-based microspheres to induce the differentiation of mesenchymal stem/stromal cells (MSC) into chondrocytes. To this aim, we tested microspheres releasing TGFβ3 (PAM-T) in vitro and in situ, in a pathological osteoarthritic (OA) environment. We first evaluated the chondrogenic differentiation of human MSCs seeded onto PAM-T in vitro and confirmed the up-regulation of chondrogenic markers while the secretome of the cells was not changed by the 3D environment. We then injected human MSC seeded onto PAM-T in the knee joints of mice with collagenase-induced OA. After 6 weeks, histological analysis revealed that formation of a cartilage-like tissue occurred at the vicinity of PAM-T that was not observed when MSCs were seeded onto PAM. We also noticed that the endogenous articular cartilage was less degraded. The extent of cartilage protection was further analysed by confocal laser microscopy. When MSCs seeded onto PAM-T were injected early after OA induction, protection of cartilage against degradation was evidenced and this effect was associated to a higher survival of MSCs in presence of TGFβ3. This study points to the interest of using MSCs seeded onto PAM for cartilage repair and stimulation of endogenous cartilage regeneration. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. TGF-ß1 enhances the BMP-2-induced chondrogenesis of bovine synovial explants and arrests downstream differentiation at an early stage of hypertrophy.

    Science.gov (United States)

    Shintani, Nahoko; Siebenrock, Klaus A; Hunziker, Ernst B

    2013-01-01

    Synovial explants furnish an in-situ population of mesenchymal stem cells for the repair of articular cartilage. Although bone morphogenetic protein 2 (BMP-2) induces the chondrogenesis of bovine synovial explants, the cartilage formed is neither homogeneously distributed nor of an exclusively hyaline type. Furthermore, the downstream differentiation of chondrocytes proceeds to the stage of terminal hypertrophy, which is inextricably coupled with undesired matrix mineralization. With a view to optimizing BMP-2-induced chondrogenesis, the modulating influences of fibroblast growth factor 2 (FGF-2) and transforming growth factor beta 1 (TGF-ß1) were investigated. Explants of bovine calf metacarpal synovium were exposed to BMP-2 (200 ng/ml) for 4 (or 6) weeks. FGF-2 (10 ng/ml) or TGF-ß1 (10 ng/ml) was introduced at the onset of incubation and was present either during the first week of culturing alone or throughout its entire course. FGF-2 enhanced the BMP-2-induced increase in metachromatic staining for glycosaminoglycans (GAGs) only when it was present during the first week of culturing alone. TGF-ß1 enhanced not only the BMP-2-induced increase in metachromasia (to a greater degree than FGF-2), but also the biochemically-assayed accumulation of GAGs, when it was present throughout the entire culturing period; in addition, it arrested the downstream differentiation of cells at an early stage of hypertrophy. These findings were corroborated by an analysis of the gene- and protein-expression levels of key cartilaginous markers and by an estimation of individual cell volume. TGF-ß1 enhances the BMP-2-induced chondrogenesis of bovine synovial explants, improves the hyaline-like properties of the neocartilage, and arrests the downstream differentiation of cells at an early stage of hypertrophy. With the prospect of engineering a mature, truly articular type of cartilage in the context of clinical repair, our findings will be of importance in fine-tuning the

  6. TGF-ß1 enhances the BMP-2-induced chondrogenesis of bovine synovial explants and arrests downstream differentiation at an early stage of hypertrophy.

    Directory of Open Access Journals (Sweden)

    Nahoko Shintani

    Full Text Available Synovial explants furnish an in-situ population of mesenchymal stem cells for the repair of articular cartilage. Although bone morphogenetic protein 2 (BMP-2 induces the chondrogenesis of bovine synovial explants, the cartilage formed is neither homogeneously distributed nor of an exclusively hyaline type. Furthermore, the downstream differentiation of chondrocytes proceeds to the stage of terminal hypertrophy, which is inextricably coupled with undesired matrix mineralization. With a view to optimizing BMP-2-induced chondrogenesis, the modulating influences of fibroblast growth factor 2 (FGF-2 and transforming growth factor beta 1 (TGF-ß1 were investigated.Explants of bovine calf metacarpal synovium were exposed to BMP-2 (200 ng/ml for 4 (or 6 weeks. FGF-2 (10 ng/ml or TGF-ß1 (10 ng/ml was introduced at the onset of incubation and was present either during the first week of culturing alone or throughout its entire course. FGF-2 enhanced the BMP-2-induced increase in metachromatic staining for glycosaminoglycans (GAGs only when it was present during the first week of culturing alone. TGF-ß1 enhanced not only the BMP-2-induced increase in metachromasia (to a greater degree than FGF-2, but also the biochemically-assayed accumulation of GAGs, when it was present throughout the entire culturing period; in addition, it arrested the downstream differentiation of cells at an early stage of hypertrophy. These findings were corroborated by an analysis of the gene- and protein-expression levels of key cartilaginous markers and by an estimation of individual cell volume.TGF-ß1 enhances the BMP-2-induced chondrogenesis of bovine synovial explants, improves the hyaline-like properties of the neocartilage, and arrests the downstream differentiation of cells at an early stage of hypertrophy. With the prospect of engineering a mature, truly articular type of cartilage in the context of clinical repair, our findings will be of importance in fine-tuning the

  7. Phase I study of transforming growth factor-beta 3 mouthwashes for prevention of chemotherapy-induced mucositis

    NARCIS (Netherlands)

    Wymenga, ANM; van der Graaf, WTA; Hofstra, LS; Spijkervet, FKL; Timens, W; Timmer-Bosscha, H; Sluiter, WJ; van Buuren, AHJAW; Mulder, NH; de Vries, EGE

    The purpose of this study was to establish the safety and tolerability of recombinant transforming growth factor-beta 3 (TGF-beta 3; CGP 46614) mouthwashes intended for prevention of chemotherapy-induced mucositis. Local effects were especially analyzed by objective and subjective measurements of

  8. p38 MAPK mediated in compressive stress-induced chondrogenesis of rat bone marrow MSCs in 3D alginate scaffolds.

    Science.gov (United States)

    Li, Juan; Zhao, Zhihe; Yang, Jingyuan; Liu, Jun; Wang, Jun; Li, Xiaoyu; Liu, Yurong

    2009-12-01

    Mesenchymal stem cells (MSCs) are well known to have the capability to form bone and cartilage, and chondrogenesis derived from MSCs is reported to be affected by mechanical stimuli. This research was aimed to study the effects of cyclic compressive stress on the chondrogenic differentiation of rat bone marrow-derived MSCs (BMSCs) which were encapsulated in alginate scaffolds and cultured with or without chondrogenic medium, and to investigate the role of p38 MAPK phospho-relay cascade in this process. The results show that the gene expression of chondrocyte-specific markers of Col2alpha1, aggrecan, Sox9, Runx2, and Ihh was upregulated by dynamic compressive stress introduced at the 8th day of chondrogenic differentiation in vitro. The p38 MAPK was activated by chondrogenic cytokines in a slow and lagged way, but activated by cyclic compressive stimulation in a rapid and transient manner. And inhibition of p38 activity with SB203580 suppressed gene expression of chondrocyte-specific genes stimulated by chondrogenic medium and (or) cyclic compressive stress. These findings suggest that p38 MAPK signal acts as an essential mediator in the mechano-biochemical transduction and subsequent transcriptional regulation in the process of chondrogenesis.

  9. Chondrogenesis of Embryonic Stem Cell-Derived Mesenchymal Stem Cells Induced by TGFβ1 and BMP7 Through Increased TGFβ Receptor Expression and Endogenous TGFβ1 Production.

    Science.gov (United States)

    Lee, Patrick T; Li, Wan-Ju

    2017-01-01

    For decades stem cells have proven to be invaluable to the study of tissue development. More recently, mesenchymal stem cells (MSCs) derived from embryonic stem cells (ESCs) (ESC-MSCs) have emerged as a cell source with great potential for the future of biomedical research due to their enhanced proliferative capability compared to adult tissue-derived MSCs and effectiveness of musculoskeletal lineage-specific cell differentiation compared to ESCs. We have previously compared the properties and differentiation potential of ESC-MSCs to bone marrow-derived MSCs. In this study, we evaluated the potential of TGFβ1 and BMP7 to induce chondrogenic differentiation of ESC-MSCs compared to that of TGFβ1 alone and further investigated the cellular phenotype and intracellular signaling in response to these induction conditions. Our results showed that the expression of cartilage-associated markers in ESC-MSCs induced by the TGFβ1 and BMP7 combination was increased compared to induction with TGFβ1 alone. The TGFβ1 and BMP7 combination upregulated the expression of TGFβ receptor and the production of endogenous TGFβs compared to TGFβ1 induction. The growth factor combination also increasingly activated both of the TGF and BMP signaling pathways, and inhibition of the signaling pathways led to reduced chondrogenesis of ESC-MSCs. Our findings suggest that by adding BMP7 to TGFβ1-supplemented induction medium, ESC-MSC chondrogenesis is upregulated through increased production of endogenous TGFβ and activities of TGFβ and BMP signaling. J. Cell. Biochem. 118: 172-181, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  10. TGF-β1, GDF-5, and BMP-2 stimulation induces chondrogenesis in expanded human articular chondrocytes and marrow-derived stromal cells.

    Science.gov (United States)

    Murphy, Meghan K; Huey, Daniel J; Hu, Jerry C; Athanasiou, Kyriacos A

    2015-03-01

    Replacement of degenerated cartilage with cell-based cartilage products may offer a long-term solution to halt arthritis' degenerative progression. Chondrocytes are frequently used in cell-based FDA-approved cartilage products; yet human marrow-derived stromal cells (hMSCs) show significant translational potential, reducing donor site morbidity and maintaining their undifferentiated phenotype with expansion. This study sought to investigate the effects of transforming growth factor β1 (TGF-β1), growth/differentiation factor 5 (GDF-5), and bone morphogenetic protein 2 (BMP-2) during postexpansion chondrogenesis in human articular chondrocytes (hACs) and to compare chondrogenesis in passaged hACs with that of passaged hMSCs. Through serial expansion, chondrocytes dedifferentiated, decreasing expression of chondrogenic genes while increasing expression of fibroblastic genes. However, following expansion, 10 ng/mL TGF-β1, 100 ng/mL GDF-5, or 100 ng/mL BMP-2 supplementation during three-dimensional aggregate culture each upregulated one or more markers of chondrogenic gene expression in both hACs and hMSCs. Additionally, in both cell types, the combination of TGF-β1, GDF-5, and BMP-2 induced the greatest upregulation of chondrogenic genes, that is, Col2A1, Col2A1/Col1A1 ratio, SOX9, and ACAN, and synthesis of cartilage-specific matrix, that is, glycosaminoglycans (GAGs) and ratio of collagen II/I. Finally, TGF-β1, GDF-5, and BMP-2 stimulation yielded mechanically robust cartilage rich in collagen II and GAGs in both cell types, following 4 weeks maturation. This study illustrates notable success in using the self-assembling method to generate robust, scaffold-free neocartilage constructs using expanded hACs and hMSCs. © 2014 AlphaMed Press.

  11. Osmolyte Type and the Osmolarity Level Affect Chondrogenesis of Mesenchymal Stem Cells.

    Science.gov (United States)

    Ahmadyan, Sorour; Kabiri, Mahboubeh; Hanaee-Ahvaz, Hana; Farazmand, Ali

    2017-11-10

    The inductive effects of increased osmolarity on chondrogenesis are well approved. However, the effects of the osmolyte agent invoked to induce hyperosmolarity are largely neglected. Herein, we scrutinized how hyperosmotic conditions acquired by addition of different osmolytes would impact chondrogenesis. We briefly assessed whether such conditions would differentially affect hypertrophy and angiogenesis during MSC chondrogenesis. Chondrogenic and hypertrophic marker expression along with VEGF secretion during adipose-derived (AD)-MSC chondrogenesis under three osmolarity levels (350, 450, and 550 mOsm) using three different osmolytes (NaCl, sorbitol, and PEG) were assessed. MTT assay, qRT-PCR, immunocytochemistry, Alcian Blue staining, ELISA, and ALP assays proved osmolyte-type dependent effects of hyperosmolarity on chondrogenesis, hypertrophy, and angiogenesis. At same osmolarity level, PEG had least cytotoxic/cytostatic effect and most prohibitive effects on angiogenesis. As expected, all hyperosmolar conditions led to enhanced chondrogenesis with slightly varying degrees. PEG and sorbitol had higher chondro-promotive and hypertrophy-suppressive effects compared to NaCl, while NaCl had exacerbated hypertrophy. We observed that TonEBP was involved in osmoadaptation of all treatments in varying degrees. Of importance, we highlighted differential effects of hyperosmolarity obtained by different osmolytes on the efficacy of chondrogenesis and more remarkably on the induction/suppression of cartilage pathologic markers. Our study underlies the need for a more vigilant exploitation of physicobiochemical inducers in order to maximize chondrogenesis while restraining unwanted hypertrophy and angiogenesis.

  12. TGFb signalling inhibits DLK1 expression during chondrogenesis in vitro

    DEFF Research Database (Denmark)

    Harkness, Linda; Taipaleenmaki, Hanna; Saamanen, Anna-Marja

    2011-01-01

    the effect of a number of signalling molecules on DLK1 expression during in vitro chondrogenic differentiation in mouse embryonic limb bud mesenchymal micromass cultures and mouse embryonic fibroblast (MEF) pellet cultures. Dlk1 was initially expressed during mesenchymal condensation and chondrocyte...... proliferation, in parallel with expression of Sox9 and Col2a1, and was down-regulated upon expression of Col10a1 by hypertrophic chondrocytes. Among a number of molecules that affected chondrogenesis, TGF-b signalling regulated Dlk1expression. TGF-b1-induced chondrogenesis was associated with decreased Dlk1...... expression and these effects were abolished by the TGF-b signalling inhibitor SB4311542 suggesting an involvement of DLK1/FA1 in mediating the function of TGF-b1 signalling in chondrogenesis. In support of this hypothesis, we found that TGF-b1 enhanced chondrocyte differentiation in dlk1-/- MEF compared...

  13. Insulin is essential for in vitro chondrogenesis of mesenchymal progenitor cells and influences chondrogenesis in a dose-dependent manner.

    Science.gov (United States)

    Mueller, Michael B; Blunk, Torsten; Appel, Bernhard; Maschke, Angelika; Goepferich, Achim; Zellner, Johannes; Englert, Carsten; Prantl, Lukas; Kujat, Richard; Nerlich, Michael; Angele, Peter

    2013-01-01

    Insulin is a commonly used additive in chondrogenic media for differentiating mesenchymal stem cells (MSCs). The indispensability of other bioactive factors like TGF-β or dexamethasone in these medium formulations has been shown, but the role of insulin is unclear. The purpose of this study was to investigate whether insulin is essential for MSC chondrogenesis and if there is a dose-dependent effect of insulin on MSC chondrogenesis. We cultivated human MSCs in pellet culture in serum-free chondrogenic medium with insulin concentrations between 0 and 50 μg/ml and assessed the grade of chondrogenic differentiation by histological evaluation and determination of glycosaminoglycan (GAG), total collagen and DNA content. We further tested whether insulin can be delivered in an amount sufficient for MSC chondrogenesis via a drug delivery system in insulin-free medium. Chondrogenesis was not induced by standard chondrogenic medium without insulin and the expression of cartilage differentiation markers was dose-dependent at insulin concentrations between 0 and 10 μg/ml. An insulin concentration of 50 μg/ml had no additional effect compared with 10 μg/ml. Insulin was delivered by a release system into the cell culture under insulin-free conditions in an amount sufficient to induce chondrogenesis. Insulin is essential for MSC chondrogenesis in this system and chondrogenic differentiation is influenced by insulin in a dose-dependent manner. Insulin can be provided in a sufficient amount by a drug delivery system. Therefore, insulin is a suitable and inexpensive indicator substance for testing drug release systems in vitro.

  14. Co-delivery of Cbfa-1-targeting siRNA and SOX9 protein using PLGA nanoparticles to induce chondrogenesis of human mesenchymal stem cells.

    Science.gov (United States)

    Jeon, Su Yeon; Park, Ji Sun; Yang, Han Na; Lim, Hye Jin; Yi, Se Won; Park, Hansoo; Park, Keun-Hong

    2014-09-01

    During stem cell differentiation, various cellular responses occur that are mediated by transcription factors and proteins. This study evaluated the abilities of SOX9, a crucial protein during the early stage of chondrogenesis, and siRNA targeting Cbfa-1, a transcription factor that promotes osteogenesis, to stimulate chondrogenesis. Non-toxic poly-(d,l-lactide-co-glycolide) (PLGA) nanoparticles (NPs) were coated with Cbfa-1-targeting siRNA and loaded with SOX9 protein. Coomassie blue staining and circular dichroism revealed that the loaded SOX9 protein maintained its stability and bioactivity. These NPs easily entered human mesenchymal stem cells (hMSCs) in vitro and caused them to differentiate into chondrocytes. Markers that are typically expressed in mature chondrocytes were examined. These markers were highly expressed at the mRNA and protein levels in hMSCs treated with PLGA NPs coated with Cbfa-1-targeting siRNA and loaded with SOX9 protein. By contrast, these cells did not express osteogenesis-related markers. hMSCs were injected into mice following internalization of PLGA NPs coated with Cbfa-1-targeting siRNA and loaded with SOX9 protein. When the injection site was excised, markers of chondrogenesis were found to be highly expressed at the mRNA and protein levels, similar to the in vitro results. When hMSCs internalized these NPs and were then cultured in vitro or injected into mice, chondrogenesis-related extracellular matrix components were highly expressed. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Rac1 promotes chondrogenesis by regulating STAT3 signaling pathway.

    Science.gov (United States)

    Kim, Hyoin; Sonn, Jong Kyung

    2016-09-01

    The small GTPase protein Rac1 is involved in a wide range of biological processes including cell differentiation. Previously, Rac1 was shown to promote chondrogenesis in micromass cultures of limb mesenchyme. However, the pathways mediating Rac1's role in chondrogenesis are not fully understood. This study aimed to explore the molecular mechanisms by which Rac1 regulates chondrogenic differentiation. Phosphorylation of signal transducer and activator of transcription 3 (STAT3) was increased as chondrogenesis proceeded in micromass cultures of chick wing bud mesenchyme. Inhibition of Rac1 with NSC23766, janus kinase 2 (JAK2) with AG490, or STAT3 with stattic inhibited chondrogenesis and reduced phosphorylation of STAT3. Conversely, overexpression of constitutively active Rac1 (Rac L61) increased phosphorylation of STAT3. Rac L61 expression resulted in increased expression of interleukin 6 (IL-6), and treatment with IL-6 increased phosphorylation of STAT3. NSC23766, AG490, and stattic prohibited cell aggregation, whereas expression of Rac L61 increased cell aggregation, which was reduced by stattic treatment. Our studies indicate that Rac1 induces STAT3 activation through expression and action of IL-6. Overexpression of Rac L61 increased expression of bone morphogenic protein 4 (BMP4). BMP4 promoted chondrogenesis, which was inhibited by K02288, an activin receptor-like kinase-2 inhibitor, and increased phosphorylation of p38 MAP kinase. Overexpression of Rac L61 also increased phosphorylation of p38 MAPK, which was reduced by K02288. These results suggest that Rac1 activates STAT3 by expression of IL-6, which in turn increases expression and activity of BMP4, leading to the promotion of chondrogenesis. © 2016 International Federation for Cell Biology.

  16. Delayed gadolinium-enhanced MRI of cartilage of the ankle joint: Results after autologous matrix-induced chondrogenesis (AMIC)-aided reconstruction of osteochondral lesions of the talus

    International Nuclear Information System (INIS)

    Wiewiorski, M.; Miska, M.; Kretzschmar, M.; Studler, U.; Bieri, O.; Valderrabano, V.

    2013-01-01

    Aim: To assess cartilage quality using delayed gadolinium-enhanced magnetic resonance imaging after repair of osteochondral lesions of the talus using autologous matrix-induced chondrogenesis (AMIC). Materials and methods: A three-dimensional (3D) spoiled gradient-echo (SGE) sequence at 3 T was used to obtain quantitative T1 relaxation times before and after Gd-DTPA2 (Magnevist, 0.2 mM/kg bod weight) administration to assess 23 cases of AMIC-aided repair of osteochondral lesions of the talus. Delta relaxation rates (ΔR1) for reference cartilage (RC) and repair tissue (RT), and the relative delta relaxation rate (rΔR1) were calculated. The morphological appearance of the cartilage RT was graded on sagittal dual-echo steady-state (DESS) views according to the “magnetic resonance observation of cartilage repair tissue” (MOCART) protocol. The study was approved by the institutional review board and written consent from each patient was obtained. Results: The AMIC cases had a mean T1 relaxation time of 1.194 s (SD 0.207 s) in RC and 1.470 s (SD 0.384 s) in RT before contrast medium administration. The contrast-enhanced T1 relaxation time decreased to 0.480 s (SD 0.114 s) in RC and 0.411 s (SD 0.096 s) in RT. There was a significant difference (p > 0.05) between the ΔR1 in RC (1.372 × 10 −3 /s, range 0.526–3.201 × 10 −3 /s, SD 0.666 × 10 −3 /s) and RT (1.856 × 10 −3 /s, range 0.93–3.336 × 10 −3 /s, SD 0.609 × 10 −3 /s). The mean rΔR1 was 1.49, SD 0.45). The mean MOCART score at follow-up was 62.6 points (range 30–95, SD 15.3). Conclusion: The results of the present study suggest that repair cartilage resulting from AMIC-aided repair of osteochondral lesions of the talus has a significantly lower glycosaminoglycan (GAG) content than normal hyaline cartilage, but can be regarded as having hyaline-like properties

  17. RhoA/Rho kinase signaling regulates transforming growth factor-β1-induced chondrogenesis and actin organization of synovium-derived mesenchymal stem cells through interaction with the Smad pathway.

    Science.gov (United States)

    Xu, Ting; Wu, Mengjie; Feng, Jianying; Lin, Xinping; Gu, Zhiyuan

    2012-11-01

    Recent studies have suggested that synovium-derived mesenchymal stem cells (SMSCs) may be promising candidates for tissue engineering and play an important role in cartilage regeneration. However, the mechanisms of SMSC chondrogenesis remain to be identified and characterized. The aim of this study was to evaluate the activation of the RhoA/Rho kinase (ROCK) pathway, as well as the manner by which it may contribute to chondrogenesis and the actin cytoskeletal organization of rat temporomandibular SMSCs in response to transforming growth factor-β1 (TGF-β1). Primary isolated SMSCs were treated with TGF-β1, and their actin organization was examined by fluorescein isothiocyanate-phalloidin staining. The specific biochemical inhibitors, C3 transferase, Y27632 and SB431542, were employed to evaluate the function of RhoA/ROCK and Smads. The effect of C3 transferase and Y27632 on the gene expression of chondrocyte-specific markers was evaluated by quantitative real-time polymerase chain reaction. To examine the effect of Y27632 on Smad2/3 phosphorylation induced by TGF-β1, western blot analysis was also performed. The stimulation of TGF-β1 in SMSCs resulted in the activation of the RhoA/ROCK pathway and concomitantly induced cytoskeletal reorganization, which was specifically blocked by C3 transferase and Y27632. The TGF-β-induced gene expression of Sox9, type I collagen, type II collagen and aggrecan was also inhibited by both C3 transferase and Y27632, at different levels. Y27632 treatment reduced the phosphorylation of Smad2/3 in a concentration-dependent manner. These results demonstrate the RhoA/ROCK activation regulates chondrocyte-specific gene transcription and cytoskeletal organization induced by TGF-β1 by interacting with the Smad pathway. This may have significant implications for the successful utilization of SMSCs as a cell source for articular cartilage tissue engineering.

  18. Restoring the IL-1β/NF-κB-induced impaired chondrogenesis by diallyl disulfide in human adipose-derived mesenchymal stem cells via attenuation of reactive oxygen species and elevation of antioxidant enzymes.

    Science.gov (United States)

    Bahrampour Juybari, Kobra; Kamarul, Tunku; Najafi, Mohammad; Jafari, Davood; Sharifi, Ali Mohammad

    2018-03-26

    Strategies based on mesenchymal stem cell (MSC) therapy for restoring injured articular cartilage are not effective enough in osteoarthritis (OA). Due to the enhanced inflammation and oxidative stress in OA microenvironment, differentiation of MSCs into chondrocytes would be impaired. This study aims to explore the effects of diallyl disulfide (DADS) on IL-1β-mediated inflammation and oxidative stress in human adipose derived mesenchymal stem cells (hADSCs) during chondrogenesis. MTT assay was employed to examine the effects of various concentrations of DADS on the viability of hADSCs at different time scales to obtain non-cytotoxic concentration range of DADS. The effects of DADS on IL-1β-induced intracellular ROS generation and lipid peroxidation were evaluated in hADSCs. Western blotting was used to analyze the protein expression levels of IκBα (np), IκBα (p), NF-κB (np) and NF-κB (p). Furthermore, the gene expression levels of antioxidant enzymes in hADSCs and chondrogenic markers at days 7, 14 and 21 of differentiation were measured using qRT-PCR. The results showed that addition of DADS significantly enhanced the mRNA expression levels of antioxidant enzymes as well as reduced ROS elevation, lipid peroxidation, IκBα activation and NF-κB nuclear translocation in hADSCs treated with IL-1β. In addition, DADS could significantly increase the expression levels of IL-1β-induced impaired chondrogenic marker genes in differentiated hADSCs. Treatment with DADS may provide an effective approach to prevent the pro-inflammatory cytokines and oxidative stress as catabolic causes of chondrocyte cell death and enhance the protective anabolic effects by promoting chondrogenesis associated gene expressions in hADSCs exposed to OA condition.

  19. Induction of mesenchymal stem cell chondrogenesis by polyacrylate substrates

    OpenAIRE

    Glennon-Alty, Laurence; Williams, Rachel; Dixon, Simon; Murray, Patricia

    2013-01-01

    Mesenchymal stem cells (MSCs) can generate chondrocytes in vitro, but typically need to be cultured as aggregates in the presence of transforming growth factor beta (TGF-?), which makes scale-up difficult. Here we investigated if polyacrylate substrates modelled on the functional group composition and distribution of the Arg-Gly-Asp (RGD) integrin-binding site could induce MSCs to undergo chondrogenesis in the absence of exogenous TGF-?. Within a few days of culture on the biomimetic polyacry...

  20. Induction of mesenchymal stem cell chondrogenesis by polyacrylate substrates.

    Science.gov (United States)

    Glennon-Alty, Laurence; Williams, Rachel; Dixon, Simon; Murray, Patricia

    2013-04-01

    Mesenchymal stem cells (MSCs) can generate chondrocytes in vitro, but typically need to be cultured as aggregates in the presence of transforming growth factor beta (TGF-β), which makes scale-up difficult. Here we investigated if polyacrylate substrates modelled on the functional group composition and distribution of the Arg-Gly-Asp (RGD) integrin-binding site could induce MSCs to undergo chondrogenesis in the absence of exogenous TGF-β. Within a few days of culture on the biomimetic polyacrylates, both mouse and human MSCs, and a mesenchymal-like mouse-kidney-derived stem cell line, began to form multi-layered aggregates and started to express the chondrocyte-specific markers, Sox9, collagen II and aggrecan. Moreover, collagen II tended to be expressed in the centre of the aggregates, similarly to developing limb buds in vivo. Surface analysis of the substrates indicated that those with the highest surface amine content were most effective at promoting MSC chondrogenesis. These results highlight the importance of surface group functionality and the distribution of those groups in the design of substrates to induce MSC chondrogenesis. Copyright © 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  1. The Cross-talk Between TGF-β1 and Dlk1 Mediates Early Chondrogenesis During Embryonic Endochondral Ossification

    DEFF Research Database (Denmark)

    Taipaleenmaki, Hanna; M, Linda; Chen, Li

    2012-01-01

    Dlkl/Pref-1/FA1 (delta like-1/preadipocyte factor-1/Fetal Antigen-1) is a novel surface marker for embryonic chondroprogenitor cells undergoing lineage progression from proliferation to prehypertrophic stages. However, mechanisms mediating control of its expression during chondrogenesis...... during mesenchymal condensation and chondrocyte proliferation, in parallel with expression of Sox9 and Col2a1, and was down-regulated upon the expression of Col10a1 by hypertrophic chondrocytes. Among a number of molecules that affected chondrogenesis, TGF-β1-induced proliferation of chondroprogenitors...... was associated with decreased Dlk1 expression. This effect was abolished by TGF-β signalling inhibitor SB431542, suggesting regulation of Dlk1/FA1 by TGF-β1 signalling in chondrogenesis. TGF-β1-induced Smad phosphorylation and chondrogenesis were significantly increased in Dlk1 (-/-) MEF, while they were blocked...

  2. Evaluation of insulin medium or chondrogenic medium on proliferation and chondrogenesis of ATDC5 cells.

    Science.gov (United States)

    Yao, Yongchang; Zhai, Zhichen; Wang, Yingjun

    2014-01-01

    The ATDC5 cell line is regarded as an excellent cell model for chondrogenesis. In most studies with ATDC5 cells, insulin medium (IM) was used to induce chondrogenesis while chondrogenic medium (CM), which was usually applied in chondrogenesis of mesenchymal stem cells (MSCs), was rarely used for ATDC5 cells. This study was mainly designed to investigate the effect of IM, CM, and growth medium (GM) on chondrogenesis of ATDC5 cells. ATDC5 cells were, respectively, cultured in IM, CM, and GM for a certain time. Then the proliferation and the chondrogenesis progress of cells in these groups were analyzed. Compared with CM and GM, IM promoted the proliferation of cells significantly. CM was effective for enhancement of cartilage specific markers, while IM induced the cells to express endochondral ossification related genes. Although GAG deposition per cell in CM group was significantly higher than that in IM and GM groups, the total GAG contents in IM group were the most. This study demonstrated that CM focused on induction of chondrogenic differentiation while IM was in favor of promoting proliferation and expression of endochondral ossification related genes. Combinational use of these two media would be more beneficial to bone/cartilage repair.

  3. Evaluation of Insulin Medium or Chondrogenic Medium on Proliferation and Chondrogenesis of ATDC5 Cells

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    Yongchang Yao

    2014-01-01

    Full Text Available Background. The ATDC5 cell line is regarded as an excellent cell model for chondrogenesis. In most studies with ATDC5 cells, insulin medium (IM was used to induce chondrogenesis while chondrogenic medium (CM, which was usually applied in chondrogenesis of mesenchymal stem cells (MSCs, was rarely used for ATDC5 cells. This study was mainly designed to investigate the effect of IM, CM, and growth medium (GM on chondrogenesis of ATDC5 cells. Methods. ATDC5 cells were, respectively, cultured in IM, CM, and GM for a certain time. Then the proliferation and the chondrogenesis progress of cells in these groups were analyzed. Results. Compared with CM and GM, IM promoted the proliferation of cells significantly. CM was effective for enhancement of cartilage specific markers, while IM induced the cells to express endochondral ossification related genes. Although GAG deposition per cell in CM group was significantly higher than that in IM and GM groups, the total GAG contents in IM group were the most. Conclusion. This study demonstrated that CM focused on induction of chondrogenic differentiation while IM was in favor of promoting proliferation and expression of endochondral ossification related genes. Combinational use of these two media would be more beneficial to bone/cartilage repair.

  4. Electrical stimulation drives chondrogenesis of mesenchymal stem cells in the absence of exogenous growth factors

    Science.gov (United States)

    Kwon, Hyuck Joon; Lee, Gyu Seok; Chun, Honggu

    2016-01-01

    Electrical stimulation (ES) is known to guide the development and regeneration of many tissues. However, although preclinical and clinical studies have demonstrated superior effects of ES on cartilage repair, the effects of ES on chondrogenesis remain elusive. Since mesenchyme stem cells (MSCs) have high therapeutic potential for cartilage regeneration, we investigated the actions of ES during chondrogenesis of MSCs. Herein, we demonstrate for the first time that ES enhances expression levels of chondrogenic markers, such as type II collagen, aggrecan, and Sox9, and decreases type I collagen levels, thereby inducing differentiation of MSCs into hyaline chondrogenic cells without the addition of exogenous growth factors. ES also induced MSC condensation and subsequent chondrogenesis by driving Ca2+/ATP oscillations, which are known to be essential for prechondrogenic condensation. In subsequent experiments, the effects of ES on ATP oscillations and chondrogenesis were dependent on extracellular ATP signaling via P2X4 receptors, and ES induced significant increases in TGF-β1 and BMP2 expression. However, the inhibition of TGF-β signaling blocked ES-driven condensation, whereas the inhibition of BMP signaling did not, indicating that TGF-β signaling but not BMP signaling mediates ES-driven condensation. These findings may contribute to the development of electrotherapeutic strategies for cartilage repair using MSCs. PMID:28004813

  5. Endogenously produced Indian Hedgehog regulates TGFβ-driven chondrogenesis of human bone marrow stromal/stem cells.

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    Handorf, Andrew M; Chamberlain, Connie S; Li, Wan-Ju

    2015-04-15

    Human bone marrow stromal/stem cells (hBMSCs) have an inherent tendency to undergo hypertrophy when induced into the chondrogenic lineage using transforming growth factor-beta 1 (TGFβ) in vitro, reminiscent of what occurs during endochondral ossification. Surprisingly, Indian Hedgehog (IHH) has received little attention for its role during hBMSC chondrogenesis despite being considered a master regulator of endochondral ossification. In this study, we investigated the role that endogenously produced IHH plays during hBMSC chondrogenesis. We began by analyzing the expression of IHH throughout differentiation using quantitative polymerase chain reaction and found that IHH expression was upregulated dramatically upon chondrogenic induction and peaked from days 9 to 12 of differentiation, which coincided with a concomitant increase in the expression of chondrogenesis- and hypertrophy-related markers, suggesting a potential role for endogenously produced IHH in driving hBMSC chondrogenesis. More importantly, pharmacological inhibition of Hedgehog signaling with cyclopamine or knockdown of IHH almost completely blocked TGFβ1-induced chondrogenesis in hBMSCs, demonstrating that endogenously produced IHH is necessary for hBMSC chondrogenesis. Furthermore, overexpression of IHH was sufficient to drive chondrogenic differentiation, even when TGFβ signaling was inhibited. Finally, stimulation with TGFβ1 induced a significant and sustained upregulation of IHH expression within 3 h that preceded an upregulation in all cartilage-related genes analyzed, and knockdown of IHH blocked the effects of TGFβ1 entirely, suggesting that the effects of TGFβ1 are being mediated through endogenously produced IHH. Together, our findings demonstrate that endogenously produced IHH is playing a critical role in regulating hBMSC chondrogenesis.

  6. Midazolam inhibits chondrogenesis via peripheral benzodiazepine receptor in human mesenchymal stem cells.

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    Chen, Yung-Ching; Wu, King-Chuen; Huang, Bu-Miin; So, Edmund Cheung; Wang, Yang-Kao

    2018-05-01

    Midazolam, a benzodiazepine derivative, is widely used for sedation and surgery. However, previous studies have demonstrated that Midazolam is associated with increased risks of congenital malformations, such as dwarfism, when used during early pregnancy. Recent studies have also demonstrated that Midazolam suppresses osteogenesis of mesenchymal stem cells (MSCs). Given that hypertrophic chondrocytes can differentiate into osteoblast and osteocytes and contribute to endochondral bone formation, the effect of Midazolam on chondrogenesis remains unclear. In this study, we applied a human MSC line, the KP cell, to serve as an in vitro model to study the effect of Midazolam on chondrogenesis. We first successfully established an in vitro chondrogenic model in a micromass culture or a 2D high-density culture performed with TGF-β-driven chondrogenic induction medium. Treatment of the Midazolam dose-dependently inhibited chondrogenesis, examined using Alcian blue-stained glycosaminoglycans and the expression of chondrogenic markers, such as SOX9 and type II collagen. Inhibition of Midazolam by peripheral benzodiazepine receptor (PBR) antagonist PK11195 or small interfering RNA rescued the inhibitory effects of Midazolam on chondrogenesis. In addition, Midazolam suppressed transforming growth factor-β-induced Smad3 phosphorylation, and this inhibitory effect could be rescued using PBR antagonist PK11195. This study provides a possible explanation for Midazolam-induced congenital malformations of the musculoskeletal system through PBR. © 2018 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

  7. Methylation-mediated silencing of miR-124 facilitates chondrogenesis by targeting NFATc1 under hypoxic conditions.

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    Gong, Ming; Liang, Tangzhao; Jin, Song; Dai, Xuejun; Zhou, Zhiyu; Gao, Manman; Huang, Sheng; Luo, Jiaquan; Zou, Lijin; Zou, Xuenong

    2017-01-01

    Chondrogenic differentiation of mesenchymal stem cells is regulated by many different pathways. Recent studies have established that hypoxia and epigenetic alterations potently affect expression of chondrogenesis marker genes. Sox9 is generally regarded as a master regulator of chondrogenesis and microRNA-124 (miRNA-124) regulates gene expression in murine bone marrow-derived mesenchymal stem cells. Therefore, in this study we investigated whether epigenetic regulation of miRNA-124 could affect the expression of Sox9 and thereby regulate chondrogenesis. A cell pellet culture model was used to induce chondrogenesis in C3H10T1/2 cells under hypoxic conditions (2% O 2 ) to determine the effects of hypoxia on miR-124 expression and DNA methylation. The expression of miR-124 was significantly downregulated under hypoxic conditions compared to normoxic conditions (21% O 2 ). The expression of chondrogenesis marker genes was significantly increased under hypoxic conditions. Bisulfite sequencing of the CpG islands in the promoter region of miR-124-3 showed that CpG methylation was significantly increased under hypoxic conditions. Treating the cells with the DNA demethylating agent 5'-AZA significantly increased miR-124 expression and decreased expression of markers of chondrogenesis. Overexpressing miR-124 under hypoxic conditions inhibited NFATc1 reporter activity. NFATc1 was shown to bind to the promoter region of Sox9. Taken together, our data provide evidence that miR-124 acts as an inhibitor of NFATc1. Under hypoxic conditions when miR-124 is downregulated by methylation of CpG islands in the promoter, NFATc1 can bind to the Sox9 promoter and induce the expression of Sox9 leading to chondrogenesis. These results support the role of epigenetic regulation in establishing and maintaining a chondrogenic phenotype.

  8. Morphological evaluation during in vitro chondrogenesis of dental pulp stromal cells

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    Choo-Ryung Chung

    2012-02-01

    Full Text Available Objectives The aim was to confirm the stem cell-like properties of the dental pulp stromal cells and to evaluate the morphologic changes during in vitro chondrogenesis. Materials and Methods Stromal cells were outgrown from the dental pulp tissue of the premolars. Surface markers were investigated and cell proliferation rate was compared to other mesenchymal stem cells. Multipotency of the pulp cells was confirmed by inducing osteogenesis, adipogenesis and chondrogenesis. The morphologic changes in the chondrogenic pellet during the 21 day of induction were evaluated under light microscope and transmission electron microscope. TUNEL assay was used to evaluate apoptosis within the chondrogenic pellets. Results Pulp cells were CD90, 105 positive and CD31, 34 negative. They showed similar proliferation rate to other stem cells. Pulp cells differentiated to osteogenic, adipogenic and chondrogenic tissues. During chondrogenesis, 3-dimensional pellet was created with multi-layers, hypertrophic chondrocyte-like cells and cartilage-like extracellular matrix. However, cell morphology became irregular and apoptotic cells were increased after 7 day of chondrogenic induction. Conclusions Pulp cells indicated mesenchymal stem cell-like characteristics. During the in vitro chondrogenesis, cellular activity was superior during the earlier phase (within 7 day of differentiation.

  9. Chondrogenesis on sulfonate-coated hydrogels is regulated by their mechanical properties.

    Science.gov (United States)

    Kwon, Hyuck Joon; Yasuda, Kazunori

    2013-01-01

    Many studies have demonstrated that sulfur-containing acidic groups induce chondrogenesis in vitro and in vivo. Recently, it is increasingly clear that mechanical properties of cell substrates largely influence cell differentiation. Thus, the present study investigated how mechanical properties of sulfonate-coated hydrogels influences chondrogenesis of mesenchymal stem cells (MSCs). Sulfonate-coated polyacrylamide gels (S-PAAm gels) which have the elastic modulus, E, of about 1, 15 and 150 kPa, were used in this study. MSCs cultured on the high stiffness S-PAAm gels (E=∼150 kPa) spread out with strong expression of stress fibers, while MSCs cultured on the low stiffness S-PAAm gels (E=∼1 kPa) had round shapes with less stress fibers but more cortical actins. Importantly, even in the absence of differentiation supplements, the lower stiffness S-PAAm gels led to the higher mRNA levels of chondrogenic markers such as Col2a1, Agc and Sox9 and the lower mRNA levels of an undifferentiation marker Sca1, indicating that the mechanical properties of S-PAAm gels strongly influence chondrogenesis. Blebbistatin which blocks myosin II-mediated mechanical sensing suppressed chondrogenesis induced by the low stiffness S-PAAm gels. The present study demonstrates that the soft S-PAAm gels effectively drive MSC chondrogenesis even in the absence of soluble differentiation factors and thus suggests that sulfonate-containing hydrogels with low stiffness could be a powerful tool for cartilage regeneration. Copyright © 2012 Elsevier Ltd. All rights reserved.

  10. Effects of solid acellular type-I/III collagen biomaterials on in vitro and in vivo chondrogenesis of mesenchymal stem cells.

    Science.gov (United States)

    Gao, Liang; Orth, Patrick; Cucchiarini, Magali; Madry, Henning

    2017-09-01

    Type-I/III collagen membranes are advocated for clinical use in articular cartilage repair as being able of inducing chondrogenesis, a technique termed autologous matrix-induced chondrogenesis (AMIC). Area covered: The current in vitro and translational in vivo evidence for chondrogenic effects of solid acellular type-I/III collagen biomaterials. Expert commentary: In vitro, mesenchymal stem cells (MSCs) adhere to the fibers of the type-I/III collagen membrane. No in vitro study provides evidence that a type-I/III collagen matrix alone may induce chondrogenesis. Few in vitro studies compare the effects of type-I and type-II collagen scaffolds on chondrogenesis. Recent investigations suggest better chondrogenesis with type-II collagen scaffolds. A systematic review of the translational in vivo data identified one long-term study showing that covering of cartilage defects treated by microfracture with a type-I/III collagen membrane significantly enhanced the repair tissue volume compared with microfracture alone. Other in vivo evidence is lacking to suggest either improved histological structure or biomechanical function of the repair tissue. Taken together, there is a paucity of in vitro and preclinical in vivo evidence supporting the concept that solid acellular type-I/III collagen scaffolds may be superior to classical approaches to induce in vitro or in vivo chondrogenesis of MSCs.

  11. Norepinephrine inhibition of mesenchymal stem cell and chondrogenic progenitor cell chondrogenesis and acceleration of chondrogenic hypertrophy.

    Science.gov (United States)

    Jenei-Lanzl, Zsuzsa; Grässel, Susanne; Pongratz, Georg; Kees, Frieder; Miosge, Nicolai; Angele, Peter; Straub, Rainer H

    2014-09-01

    Mesenchymal progenitor cell chondrogenesis is the biologic platform for the generation or regeneration of cartilage, but the external influence of the sympathetic nervous system on this process is not yet known. Sympathetic nerve fibers are present in articular tissue, and the sympathetic nervous system influences the musculoskeletal system by, for example, increasing osteoclastogenesis. This study was initiated to explore the role of the sympathetic neurotransmitter norepinephrine (NE) in mesenchymal stem cell (MSC)-dependent and cartilage progenitor cell (CPC)-dependent chondrogenesis. Using human MSCs or CPCs, chondrogenic differentiation was induced in the presence of NE, the specific β-adrenergic receptor (β-AR) agonist isoproterenol, and the specific β-AR antagonist nadolol. We studied sympathetic nerve fibers, tyrosine hydroxylase (TH) expression, catecholamine biosynthesis, and synovial fluid levels in human joints, as well as cartilage-specific matrix deposition during differentiation. TH+ sympathetic nerve fibers were present in the synovial tissue, meniscus, and subchondral bone marrow. In addition, synovial fluid from patients with knee trauma demonstrated high concentrations of NE. During MSC or CPC chondrogenesis, β-AR were expressed. Chondrogenic aggregates treated with NE or isoproterenol synthesized lower amounts of type II collagen and glycosaminoglycans. NE and isoproterenol treatment dose-dependently increased the levels of cartilage hypertrophy markers (type X collagen and matrix metalloproteinase 13). Nadolol reversed the inhibition of chondrogenesis and the up-regulation of cartilage hypertrophy. Our findings demonstrate NE-dependent inhibition of chondrogenesis and acceleration of hypertrophic differentiation. By inhibiting cartilage repair, these sympathetic influences can be important after joint trauma. These findings may be a basis for novel neurochondrogenic therapeutic options. Copyright © 2014 by the American College of

  12. Matrilin-3 chondrodysplasia mutations cause attenuated chondrogenesis, premature hypertrophy and aberrant response to TGF-β in chondroprogenitor cells.

    Science.gov (United States)

    Jayasuriya, Chathuraka T; Zhou, Fiona H; Pei, Ming; Wang, Zhengke; Lemme, Nicholas J; Haines, Paul; Chen, Qian

    2014-08-21

    Studies have shown that mutations in the matrilin-3 gene (MATN3) are associated with multiple epiphyseal dysplasia (MED) and spondyloepimetaphyseal dysplasia (SEMD). We tested whether MATN3 mutations affect the differentiation of chondroprogenitor and/or mesenchymal stem cells, which are precursors to chondrocytes. ATDC5 chondroprogenitors stably expressing wild-type (WT) MATN3 underwent spontaneous chondrogenesis. Expression of chondrogenic markers collagen II and aggrecan was inhibited in chondroprogenitors carrying the MED or SEMD MATN3 mutations. Hypertrophic marker collagen X remained attenuated in WT MATN3 chondroprogenitors, whereas its expression was elevated in chondroprogenitors expressing the MED or SEMD mutant MATN3 gene suggesting that these mutations inhibit chondrogenesis but promote hypertrophy. TGF-β treatment failed to rescue chondrogenesis markers but dramatically increased collagen X mRNA expression in mutant MATN3 expressing chondroprogenitors. Synovium derived mesenchymal stem cells harboring the SEMD mutation exhibited lower glycosaminoglycan content than those of WT MATN3 in response to TGF-β. Our results suggest that the properties of progenitor cells harboring MATN3 chondrodysplasia mutations were altered, as evidenced by attenuated chondrogenesis and premature hypertrophy. TGF-β treatment failed to completely rescue chondrogenesis but instead induced hypertrophy in mutant MATN3 chondroprogenitors. Our data suggest that chondroprogenitor cells should be considered as a potential target of chondrodysplasia therapy.

  13. Matrilin-3 Chondrodysplasia Mutations Cause Attenuated Chondrogenesis, Premature Hypertrophy and Aberrant Response to TGF-β in Chondroprogenitor Cells

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    Chathuraka T. Jayasuriya

    2014-08-01

    Full Text Available Studies have shown that mutations in the matrilin-3 gene (MATN3 are associated with multiple epiphyseal dysplasia (MED and spondyloepimetaphyseal dysplasia (SEMD. We tested whether MATN3 mutations affect the differentiation of chondroprogenitor and/or mesenchymal stem cells, which are precursors to chondrocytes. ATDC5 chondroprogenitors stably expressing wild-type (WT MATN3 underwent spontaneous chondrogenesis. Expression of chondrogenic markers collagen II and aggrecan was inhibited in chondroprogenitors carrying the MED or SEMD MATN3 mutations. Hypertrophic marker collagen X remained attenuated in WT MATN3 chondroprogenitors, whereas its expression was elevated in chondroprogenitors expressing the MED or SEMD mutant MATN3 gene suggesting that these mutations inhibit chondrogenesis but promote hypertrophy. TGF-β treatment failed to rescue chondrogenesis markers but dramatically increased collagen X mRNA expression in mutant MATN3 expressing chondroprogenitors. Synovium derived mesenchymal stem cells harboring the SEMD mutation exhibited lower glycosaminoglycan content than those of WT MATN3 in response to TGF-β. Our results suggest that the properties of progenitor cells harboring MATN3 chondrodysplasia mutations were altered, as evidenced by attenuated chondrogenesis and premature hypertrophy. TGF-β treatment failed to completely rescue chondrogenesis but instead induced hypertrophy in mutant MATN3 chondroprogenitors. Our data suggest that chondroprogenitor cells should be considered as a potential target of chondrodysplasia therapy.

  14. Extracellular matrix protein 1, a direct targeting molecule of parathyroid hormone–related peptide, negatively regulates chondrogenesis and endochondral ossification via associating with progranulin growth factor

    Science.gov (United States)

    Kong, Li; Zhao, Yun-Peng; Tian, Qing-Yun; Feng, Jian-Quan; Kobayashi, Tatsuya; Merregaert, Joseph; Liu, Chuan-Ju

    2016-01-01

    Chondrogenesis and endochondral ossification are precisely controlled by cellular interactions with surrounding matrix proteins and growth factors that mediate cellular signaling pathways. Here, we report that extracellular matrix protein 1 (ECM1) is a previously unrecognized regulator of chondrogenesis. ECM1 is induced in the course of chondrogenesis and its expression in chondrocytes strictly depends on parathyroid hormone–related peptide (PTHrP) signaling pathway. Overexpression of ECM1 suppresses, whereas suppression of ECM1 enhances, chondrocyte differentiation and hypertrophy in vitro and ex vivo. In addition, target transgene of ECM1 in chondrocytes or osteoblasts in mice leads to striking defects in cartilage development and endochondral bone formation. Of importance, ECM1 seems to be critical for PTHrP action in chondrogenesis, as blockage of ECM1 nearly abolishes PTHrP regulation of chondrocyte hypertrophy, and overexpression of ECM1 rescues disorganized growth plates of PTHrP-null mice. Furthermore, ECM1 and progranulin chondrogenic growth factor constitute an interaction network and act in concert in the regulation of chondrogenesis.—Kong, L., Zhao, Y.-P., Tian, Q.-Y., Feng, J.-Q., Kobayashi, T., Merregaert, J., Liu, C.-J. Extracellular matrix protein 1, a direct targeting molecule of parathyroid hormone–related peptide, negatively regulates chondrogenesis and endochondral ossification via associating with progranulin growth factor. PMID:27075243

  15. Apoptosis in chondrogenesis of human mesenchymal stem cells: effect of serum and medium supplements.

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    Wang, Chien-Yuan; Chen, Ling-Lan; Kuo, Pei-Yin; Chang, Jia-Ling; Wang, Yng-Jiin; Hung, Shih-Chieh

    2010-04-01

    Apoptosis is an inevitable process during development and is evident in the formation of articular cartilage and endochondral ossification of growth plate. Mesenchymal stem cells (MSCs) can serve as alternative sources for cell therapy in focal chondral lesions or diffuse osteoarthritis. But there are few, if any, studies investigating apoptosis during chondrogenesis by MSCs. The aim of this study was to find the better condition to prevent apoptosis during chondrogenesis by MSCs. Apoptosis were evaluated in MSCs induced in different chondrogenic media by the use of Annexin V, TUNEL staining, lysosomal labeling with lysotracker and immunostaining of apoptotic markers. We found apparent apoptosis was demonstrated by Annexin V, TUNEL staining and lysosomal labeling during chondrogenesis. Meanwhile, the degree of apoptosis was related to the reagents of the defined chondrogenic medium. Adding serum in medium increased apoptosis, however, TGF-beta1 inhibited apoptosis. The apoptosis was associated with the activation of caspase-3, the increase in the Bax/Bcl-2 ratio, the loss of lysosomal integrity, and the increase of PARP-cleavage. Pro-inflammatory cytokines, IL-1alpha, IL-1beta and TNFalpha did not induce any increase in apoptosis. Interestingly, the inhibition of apoptosis by serum free medium supplemented with ITS was also associated with an increase in the expression of type II collagen, and a decrease in the expression of type X collagen, Runx2, and other osteogenic genes, while TGF-beta1 increased the expression of Sox9, type II and type X collagen and decreased the expression of osteogenic genes. These data suggest apoptosis occurs during chondrogenesis by MSCs by cell death intrinsic pathway activation and this process may be modulated by culture conditions.

  16. Effects of FGF-2 on human adipose tissue derived adult stem cells morphology and chondrogenesis enhancement in Transwell culture

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    Kabiri, Azadeh, E-mail: z_kabiri@resident.mui.ac.ir [Department of Anatomical Sciences and Molecular Biology, Faculty of Medicine, Isfahan University of Medical Sciences (Iran, Islamic Republic of); Esfandiari, Ebrahim, E-mail: esfandiari@med.mui.ac.ir [Department of Anatomical Sciences and Molecular Biology, Faculty of Medicine, Isfahan University of Medical Sciences (Iran, Islamic Republic of); Hashemibeni, Batool, E-mail: hashemibeni@med.mui.ac.ir [Department of Anatomical Sciences and Molecular Biology, Faculty of Medicine, Isfahan University of Medical Sciences (Iran, Islamic Republic of); Kazemi, Mohammad, E-mail: m_kazemi@med.mui.ac.i [Department of Anatomical Sciences and Molecular Biology, Faculty of Medicine, Isfahan University of Medical Sciences (Iran, Islamic Republic of); Mardani, Mohammad, E-mail: mardani@med.mui.ac.ir [Department of Anatomical Sciences and Molecular Biology, Faculty of Medicine, Isfahan University of Medical Sciences (Iran, Islamic Republic of); Esmaeili, Abolghasem, E-mail: abesmaeili@yahoo.com [Cell, Molecular and Developmental Biology Division, Department of Biology, Faculty of Sciences, University of Isfahan, Isfahan (Iran, Islamic Republic of)

    2012-07-27

    Highlights: Black-Right-Pointing-Pointer We investigated effects of FGF-2 on hADSCs. Black-Right-Pointing-Pointer We examine changes in the level of gene expressions of SOX-9, aggrecan and collagen type II and type X. Black-Right-Pointing-Pointer FGF-2 induces chondrogenesis in hADSCs, which Bullet Increasing information will decrease quality if hospital costs are very different. Black-Right-Pointing-Pointer The result of this study may be beneficial in cartilage tissue engineering. -- Abstract: Injured cartilage is difficult to repair due to its poor vascularisation. Cell based therapies may serve as tools to more effectively regenerate defective cartilage. Both adult mesenchymal stem cells (MSCs) and human adipose derived stem cells (hADSCs) are regarded as potential stem cell sources able to generate functional cartilage for cell transplantation. Growth factors, in particular the TGF-b superfamily, influence many processes during cartilage formation, including cell proliferation, extracellular matrix synthesis, maintenance of the differentiated phenotype, and induction of MSCs towards chondrogenesis. In the current study, we investigated the effects of FGF-2 on hADSC morphology and chondrogenesis in Transwell culture. hADSCs were obtained from patients undergoing elective surgery, and then cultured in expansion medium alone or in the presence of FGF-2 (10 ng/ml). mRNA expression levels of SOX-9, aggrecan and collagen type II and type X were quantified by real-time polymerase chain reaction. The morphology, doubling time, trypsinization time and chondrogenesis of hADSCs were also studied. Expression levels of SOX-9, collagen type II, and aggrecan were all significantly increased in hADSCs expanded in presence of FGF-2. Furthermore FGF-2 induced a slender morphology, whereas doubling time and trypsinization time decreased. Our results suggest that FGF-2 induces hADSCs chondrogenesis in Transwell culture, which may be beneficial in cartilage tissue engineering.

  17. Effects of FGF-2 on human adipose tissue derived adult stem cells morphology and chondrogenesis enhancement in Transwell culture

    International Nuclear Information System (INIS)

    Kabiri, Azadeh; Esfandiari, Ebrahim; Hashemibeni, Batool; Kazemi, Mohammad; Mardani, Mohammad; Esmaeili, Abolghasem

    2012-01-01

    Highlights: ► We investigated effects of FGF-2 on hADSCs. ► We examine changes in the level of gene expressions of SOX-9, aggrecan and collagen type II and type X. ► FGF-2 induces chondrogenesis in hADSCs, which •Increasing information will decrease quality if hospital costs are very different. ► The result of this study may be beneficial in cartilage tissue engineering. -- Abstract: Injured cartilage is difficult to repair due to its poor vascularisation. Cell based therapies may serve as tools to more effectively regenerate defective cartilage. Both adult mesenchymal stem cells (MSCs) and human adipose derived stem cells (hADSCs) are regarded as potential stem cell sources able to generate functional cartilage for cell transplantation. Growth factors, in particular the TGF-b superfamily, influence many processes during cartilage formation, including cell proliferation, extracellular matrix synthesis, maintenance of the differentiated phenotype, and induction of MSCs towards chondrogenesis. In the current study, we investigated the effects of FGF-2 on hADSC morphology and chondrogenesis in Transwell culture. hADSCs were obtained from patients undergoing elective surgery, and then cultured in expansion medium alone or in the presence of FGF-2 (10 ng/ml). mRNA expression levels of SOX-9, aggrecan and collagen type II and type X were quantified by real-time polymerase chain reaction. The morphology, doubling time, trypsinization time and chondrogenesis of hADSCs were also studied. Expression levels of SOX-9, collagen type II, and aggrecan were all significantly increased in hADSCs expanded in presence of FGF-2. Furthermore FGF-2 induced a slender morphology, whereas doubling time and trypsinization time decreased. Our results suggest that FGF-2 induces hADSCs chondrogenesis in Transwell culture, which may be beneficial in cartilage tissue engineering.

  18. Chloride channels regulate chondrogenesis in chicken mandibular mesenchymal cells.

    Science.gov (United States)

    Tian, Meiyu; Duan, Yinzhong; Duan, Xiaohong

    2010-12-01

    Voltage gated chloride channels (ClCs) play an important role in the regulation of intracellular pH and cell volume homeostasis. Mutations of these genes result in genetic diseases with abnormal bone deformation and body size, indicating that ClCs may have a role in chondrogenesis. In the present study, we isolated chicken mandibular mesenchymal cells (CMMC) from Hamburg-Hamilton (HH) stage 26 chick embryos and induced chondrocyte maturation by using ascorbic acid and β-glycerophosphate (AA-BGP). We also determined the effect of the chloride channel inhibitor NPPB [5-nitro-2-(3-phenylpropylamino) benzoic acid] on regulation of growth, differentiation, and gene expression in these cells using MTT and real-time PCR assays. We found that CLCN1 and CLCN3-7 mRNA were expressed in CMMC and NPPB reduced expression of CLCN3, CLCN5, and CLCN7 mRNA in these cells. At the same time, NPPB inhibited the growth of the CMMC, but had no effect on the mRNA level of cyclin D1 and cyclin E (P>0.05) with/without AA-BGP treatment. AA-BGP increased markers for early chondrocyte differentiation including type II collagen, aggrecan (Ptype X collagen. NPPB antagonized AA-BGP-induced expression of type II collagen and aggrecan (Ptype X collagen (PType X collagen might function as a target of chloride channel inhibitors during the differentiation process. Copyright © 2010 Elsevier Ltd. All rights reserved.

  19. Retinoic acid modulates chondrogenesis in the developing mouse cranial base.

    Science.gov (United States)

    Kwon, Hyuk-Jae; Shin, Jeong-Oh; Lee, Jong-Min; Cho, Kyoung-Won; Lee, Min-Jung; Cho, Sung-Won; Jung, Han-Sung

    2011-12-15

    The retinoic acid (RA) signaling pathway is known to play important roles during craniofacial development and skeletogenesis. However, the specific mechanism involving RA in cranial base development has not yet been clearly described. This study investigated how RA modulates endochondral bone development of the cranial base by monitoring the RA receptor RARγ, BMP4, and markers of proliferation, programmed cell death, chondrogenesis, and osteogenesis. We first examined the dynamic morphological and molecular changes in the sphenooccipital synchondrosis-forming region in the mouse embryo cranial bases at E12-E16. In vitro organ cultures employing beads soaked in RA and retinoid-signaling inhibitor citral were compared. In the RA study, the sphenooccipital synchondrosis showed reduced cartilage matrix and lower BMP4 expression while hypertrophic chondrocytes were replaced with proliferating chondrocytes. Retardation of chondrocyte hypertrophy was exhibited in citral-treated specimens, while BMP4 expression was slightly increased and programmed cell death was induced within the sphenooccipital synchondrosis. Our results demonstrate that RA modulates chondrocytes to proliferate, differentiate, or undergo programmed cell death during endochondral bone formation in the developing cranial base. Copyright © 2011 Wiley Periodicals, Inc., A Wiley Company.

  20. Role of c-Myb in chondrogenesis.

    Science.gov (United States)

    Oralová, V; Matalová, E; Janečková, E; Drobná Krejčí, E; Knopfová, L; Šnajdr, P; Tucker, A S; Veselá, I; Šmarda, J; Buchtová, M

    2015-07-01

    The Myb locus encodes the c-Myb transcription factor involved in controlling a broad variety of cellular processes. Recently, it has been shown that c-Myb may play a specific role in hard tissue formation; however, all of these results were gathered from an analysis of intramembranous ossification. To investigate a possible role of c-Myb in endochondral ossification, we carried out our study on the long bones of mouse limbs during embryonic development. Firstly, the c-myb expression pattern was analyzed by in situ hybridization during endochondral ossification of long bones. c-myb positive areas were found in proliferating as well as hypertrophic zones of the growth plate. At early embryonic stages, localized expression was also observed in the perichondrium and interdigital areas. The c-Myb protein was found in proliferating chondrocytes and in the perichondrium of the forelimb bones (E14.5-E17.5). Furthermore, protein was detected in pre-hypertrophic as well as hypertrophic chondrocytes. Gain-of-function and loss-of-function approaches were used to test the effect of altered c-myb expression on chondrogenesis in micromass cultures established from forelimb buds of mouse embryos. A loss-of-function approach using c-myb specific siRNA decreased nodule formation, as well as downregulated the level of Sox9 expression, a major marker of chondrogenesis. Transient c-myb overexpression markedly increased the formation of cartilage nodules and the production of extracellular matrix as detected by intense staining with Alcian blue. Moreover, the expression of early chondrogenic genes such as Sox9, Col2a1 and activity of a Col2-LUC reporter were increased in the cells overexpressing c-myb while late chondrogenic markers such as Col10a1 and Mmp13 were not significantly changed or were downregulated. Taken together, the results of this study demonstrate that the c-Myb transcription factor is involved in the regulation and promotion of endochondral bone formation. Copyright

  1. MicroRNAs regulate osteogenesis and chondrogenesis

    International Nuclear Information System (INIS)

    Dong, Shiwu; Yang, Bo; Guo, Hongfeng; Kang, Fei

    2012-01-01

    Highlights: ► To focus on the role of miRNAs in chondrogenesis and osteogenesis. ► Involved in the regulation of miRNAs in osteoarthritis. ► To speculate some therapeutic targets for bone diseases. -- Abstract: MicroRNAs (miRNAs) are a class of small molecules and non-coding single strand RNAs that regulate gene expression at the post-transcriptional level by binding to specific sequences within target genes. miRNAs have been recognized as important regulatory factors in organism development and disease expression. Some miRNAs regulate the proliferation and differentiation of osteoblasts, osteoclasts and chondrocytes, eventually influencing metabolism and bone formation. miRNAs are expected to provide potential gene therapy targets for the clinical treatment of metabolic bone diseases and bone injuries. Here, we review the recent research progress on the regulation of miRNAs in bone biology, with a particular focus on the miRNA-mediated control mechanisms of bone and cartilage formation.

  2. MicroRNAs regulate osteogenesis and chondrogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Shiwu, E-mail: shiwudong@gmail.com [Laboratory of Biomechanics, Department of Anatomy, The Third Military Medical University, Chongqing (China); Yang, Bo; Guo, Hongfeng; Kang, Fei [Laboratory of Biomechanics, Department of Anatomy, The Third Military Medical University, Chongqing (China)

    2012-02-24

    Highlights: Black-Right-Pointing-Pointer To focus on the role of miRNAs in chondrogenesis and osteogenesis. Black-Right-Pointing-Pointer Involved in the regulation of miRNAs in osteoarthritis. Black-Right-Pointing-Pointer To speculate some therapeutic targets for bone diseases. -- Abstract: MicroRNAs (miRNAs) are a class of small molecules and non-coding single strand RNAs that regulate gene expression at the post-transcriptional level by binding to specific sequences within target genes. miRNAs have been recognized as important regulatory factors in organism development and disease expression. Some miRNAs regulate the proliferation and differentiation of osteoblasts, osteoclasts and chondrocytes, eventually influencing metabolism and bone formation. miRNAs are expected to provide potential gene therapy targets for the clinical treatment of metabolic bone diseases and bone injuries. Here, we review the recent research progress on the regulation of miRNAs in bone biology, with a particular focus on the miRNA-mediated control mechanisms of bone and cartilage formation.

  3. Phosphate regulates chondrogenesis in a biphasic and maturation-dependent manner.

    Science.gov (United States)

    Wu, Biming; Durisin, Emily K; Decker, Joseph T; Ural, Evran E; Shea, Lonnie D; Coleman, Rhima M

    Inorganic phosphate (Pi) has been recognized as an important signaling molecule that modulates chondrocyte maturation and cartilage mineralization. However, conclusive experimental evidence for its involvement in early chondrogenesis is still lacking. Here, using high-density monolayer (2D) and pellet (3D) culture models of chondrogenic ATDC5 cells, we demonstrate that the cell response to Pi does not correlate with the Pi concentration in the culture medium but is better predicted by the availability of Pi on a per cell basis (Pi abundance). Both culture models were treated with ITS+, 10mM β-glycerophosphate (βGP), or ITS+/10mM βGP, which resulted in three levels of Pi abundance in cultures: basal (Pi/DNA 60ng/µg). In chondrogenic medium alone, the abundance levels were at the basal level in 2D culture and moderate in 3D cultures. The addition of 10mM βGP resulted in moderate abundance in 2D and high abundance in 3D cultures. Moderate Pi abundance enhanced early chondrogenesis and production of aggrecan and type II collagen whereas high Pi abundance inhibited chondrogenic differentiation and induced rapid mineralization. Inhibition of sodium phosphate transporters reduced phosphate-induced expression of chondrogenic markers. When 3D ITS+/βGP cultures were treated with levamisole to reduce ALP activity, Pi abundance was decreased to moderate levels, which resulted in significant upregulation of chondrogenic markers, similar to the response in 2D cultures. Delay of phosphate delivery until after early chondrogenesis occurs (7 days) no longer enhanced chondrogenesis, but instead accelerated hypertrophy and mineralization. Together, our data highlights the dependence of chondroprogenitor cell response to Pi on its availability to individual cells and the chondrogenic maturation stage of these cells and suggest that appropriate temporal delivery of phosphate to ATDC5 cells in 3D cultures represents a rapid model for mechanistic studies into the effects of

  4. MiR-193b regulates early chondrogenesis by inhibiting the TGF-beta2 signaling pathway.

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    Hou, Changhe; Yang, Zibo; Kang, Yan; Zhang, Ziji; Fu, Ming; He, Aishan; Zhang, Zhiqi; Liao, Weiming

    2015-04-13

    Cartilage generation and degradation are regulated by miRNAs. Our previous study has shown altered expression of miR-193b in chondrogenic human adipose-derived mesenchymal stem cells (hADSCs). In the current study, we investigated the role of miR-193b in chondrogenesis and cartilage degradation. Luciferase reporter assays showed that miR-193b targeted seed sequences of the TGFB2 and TGFBR3 3'-UTRs. MiR-193b suppressed the expression of early chondrogenic markers in chondrogenic ATDC5 cells, and TNF-alpha expression in IL-1b-induced PMCs. In conclusion, MiR-193b may inhibit early chondrogenesis by targeting TGFB2 and TGFBR3, and may regulate inflammation by repressing TNF-alpha expression in inflamed chondrocytes. Copyright © 2015. Published by Elsevier B.V.

  5. Developmentally inspired programming of adult human mesenchymal stromal cells toward stable chondrogenesis.

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    Occhetta, Paola; Pigeot, Sebastien; Rasponi, Marco; Dasen, Boris; Mehrkens, Arne; Ullrich, Thomas; Kramer, Ina; Guth-Gundel, Sabine; Barbero, Andrea; Martin, Ivan

    2018-05-01

    It is generally accepted that adult human bone marrow-derived mesenchymal stromal cells (hMSCs) are default committed toward osteogenesis. Even when induced to chondrogenesis, hMSCs typically form hypertrophic cartilage that undergoes endochondral ossification. Because embryonic mesenchyme is obviously competent to generate phenotypically stable cartilage, it is questioned whether there is a correspondence between mesenchymal progenitor compartments during development and in adulthood. Here we tested whether forcing specific early events of articular cartilage development can program hMSC fate toward stable chondrogenesis. Inspired by recent findings that spatial restriction of bone morphogenetic protein (BMP) signaling guides embryonic progenitors toward articular cartilage formation, we hypothesized that selective inhibition of BMP drives the phenotypic stability of hMSC-derived chondrocytes. Two BMP type I receptor-biased kinase inhibitors were screened in a microfluidic platform for their time- and dose-dependent effect on hMSC chondrogenesis. The different receptor selectivity profile of tested compounds allowed demonstration that transient blockade of both ALK2 and ALK3 receptors, while permissive to hMSC cartilage formation, is necessary and sufficient to maintain a stable chondrocyte phenotype. Remarkably, even upon compound removal, hMSCs were no longer competent to undergo hypertrophy in vitro and endochondral ossification in vivo, indicating the onset of a constitutive change. Our findings demonstrate that adult hMSCs effectively share properties of embryonic mesenchyme in the formation of transient but also of stable cartilage. This opens potential pharmacological strategies to articular cartilage regeneration and more broadly indicates the relevance of developmentally inspired protocols to control the fate of adult progenitor cell systems.

  6. Arid5b facilitates chondrogenesis by recruiting the histone demethylase Phf2 to Sox9-regulated genes

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    Hata, Kenji; Takashima, Rikako; Amano, Katsuhiko; Ono, Koichiro; Nakanishi, Masako; Yoshida, Michiko; Wakabayashi, Makoto; Matsuda, Akio; Maeda, Yoshinobu; Suzuki, Yutaka; Sugano, Sumio; Whitson, Robert H.; Nishimura, Riko; Yoneda, Toshiyuki

    2013-11-01

    Histone modification, a critical step for epigenetic regulation, is an important modulator of biological events. Sox9 is a transcription factor critical for endochondral ossification; however, proof of its epigenetic regulation remains elusive. Here we identify AT-rich interactive domain 5b (Arid5b) as a transcriptional co-regulator of Sox9. Arid5b physically associates with Sox9 and synergistically induces chondrogenesis. Growth of Arid5b-/- mice is retarded with delayed endochondral ossification. Sox9-dependent chondrogenesis is attenuated in Arid5b-deficient cells. Arid5b recruits Phf2, a histone lysine demethylase, to the promoter region of Sox9 target genes and stimulates H3K9me2 demethylation of these genes. In the promoters of chondrogenic marker genes, H3K9me2 levels are increased in Arid5b-/- chondrocytes. Finally, we show that Phf2 knockdown inhibits Sox9-induced chondrocyte differentiation. Our findings establish an epigenomic mechanism of skeletal development, whereby Arid5b promotes chondrogenesis by facilitating Phf2-mediated histone demethylation of Sox9-regulated chondrogenic gene promoters.

  7. Enhanced chondrogenesis and Wnt signaling in PTH-treated fractures.

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    Kakar, Sanjeev; Einhorn, Thomas A; Vora, Siddharth; Miara, Lincoln J; Hon, Gregory; Wigner, Nathan A; Toben, Daniel; Jacobsen, Kimberly A; Al-Sebaei, Maisa O; Song, Michael; Trackman, Philip C; Morgan, Elise F; Gerstenfeld, Louis C; Barnes, George L

    2007-12-01

    Studies have shown that systemic PTH treatment enhanced the rate of bone repair in rodent models. However, the mechanisms through which PTH affects bone repair have not been elucidated. In these studies we show that PTH primarily enhanced the earliest stages of endochondral bone repair by increasing chondrocyte recruitment and rate of differentiation. In coordination with these cellular events, we observed an increased level of canonical Wnt-signaling in PTH-treated bones at multiple time-points across the time-course of fracture repair, supporting the conclusion that PTH responses are at least in part mediated through Wnt signaling. Since FDA approval of PTH [PTH(1-34); Forteo] as a treatment for osteoporosis, there has been interest in its use in other musculoskeletal conditions. Fracture repair is one area in which PTH may have a significant clinical impact. Multiple animal studies have shown that systemic PTH treatment of healing fractures increased both callus volume and return of mechanical competence in models of fracture healing. Whereas the potential for PTH has been established, the mechanism(s) by which PTH produces these effects remain elusive. Closed femoral fractures were generated in 8-wk-old male C57Bl/6 mice followed by daily systemic injections of either saline (control) or 30 microg/kg PTH(1-34) for 14 days after fracture. Bones were harvested at days 2, 3, 5, 7, 10, 14, 21, and 28 after fracture and analyzed at the tissue level by radiography and histomorphometry and at the molecular and biochemical levels level by RNase protection assay (RPA), real-time PCR, and Western blot analysis. Quantitative muCT analysis showed that PTH treatment induced a larger callus cross-sectional area, length, and total volume compared with controls. Molecular analysis of the expression of extracellular matrix genes associated with chondrogenesis and osteogenesis showed that PTH treated fractures displayed a 3-fold greater increase in chondrogenesis relative to

  8. Hypoxia impedes hypertrophic chondrogenesis of human multipotent stromal cells.

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    Gawlitta, Debby; van Rijen, Mattie H P; Schrijver, Edmée J M; Alblas, Jacqueline; Dhert, Wouter J A

    2012-10-01

    Within the field of bone tissue engineering, the endochondral approach to forming bone substitutes represents a novel concept, where cartilage will undergo hypertrophic differentiation before its conversion into bone. For this purpose, clinically relevant multipotent stromal cells (MSCs), MSCs, can be differentiated into the chondrogenic lineage before stimulating hypertrophy. Controversy exists in literature on the oxygen tensions naturally present during this transition in, for example, the growth plate. Therefore, the present study focused on the effects of different oxygen tensions on the progression of the hypertrophic differentiation of MSCs. Bone marrow-derived MSCs of four human donors were expanded, and differentiation was induced in aggregate cultures. Normoxic (20% oxygen) and hypoxic (5%) conditions were imposed on the cultures in chondrogenic or hypertrophic differentiation media. After 4 weeks, the cultures were histologically examined and by real-time polymerase chain reaction. Morphological assessment showed the chondrogenic differentiation of cultures from all donors under normoxic chondrogenic conditions. In addition, hypertrophic differentiation was observed in cultures derived from all but one donor. The deposition of collagen type X was evidenced in both chondrogenically and hypertrophically stimulated cultures. However, mineralization was exclusively observed in hypertrophically stimulated, normoxic cultures. Overall, the progression of hypertrophy was delayed in hypoxic compared with normoxic groups. The observed delay was supported by the gene expression patterns, especially showing the up-regulation of the late hypertrophic markers osteopontin and osteocalcin under normoxic hypertrophic conditions. Concluding, normoxic conditions are more beneficial for hypertrophic differentiation of MSCs than are hypoxic conditions, as long as the MSCs possess hypertrophic potential. This finding has implications for cartilage tissue engineering as well

  9. Regulating Chondrogenesis of Human Mesenchymal Stromal Cells with a Retinoic Acid Receptor-Beta Inhibitor: Differential Sensitivity of Chondral Versus Osteochondral Development

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    Solvig Diederichs

    2014-05-01

    Full Text Available Aim: Main objective was to investigate whether the synthetic retinoic acid receptor (RAR-β antagonist LE135 is able to drive in vitro chondrogenesis of human mesenchymal stromal cells (MSCs or improve differentiation by suppressing hypertrophic chondrocyte development. Methods: Chondrogenesis of human bone marrow and adipose tissue-derived MSCs was induced in micromass pellet culture for six weeks. Effects of LE135 alone and in combinatorial treatment with TGF-β on deposition of cartilaginous matrix including collagen type II and glycosaminoglycans, on deposition of non-hyaline cartilage collagens type I and X, and on hypertrophy markers including alkaline phosphatase (ALP, indian hedghehog (IHH and matrix metalloproteinase (MMP-13 were assessed. Results: LE135 was no inducer of chondrogenesis and failed to stimulate deposition of collagen type II and glycosaminoglycans. Moreover, addition of LE135 to TGF-β-treated pellets inhibited cartilaginous matrix deposition and gene expression of COL2A1. In contrast, non-hyaline cartilage collagens were less sensitive to LE135 and hypertrophy markers remained unaffected. Conclusion: This demonstrates a differential sensitivity of chondral versus endochondral differentiation pathways to RARβ signaling; however, opposite to the desired direction. The relevance of trans-activating versus trans-repressing RAR signaling, including effects on activator protein (AP-1 is discussed and implications for overcoming current limits of hMSC chondrogenesis are considered.

  10. Regulating chondrogenesis of human mesenchymal stromal cells with a retinoic Acid receptor-Beta inhibitor: differential sensitivity of chondral versus osteochondral development.

    Science.gov (United States)

    Diederichs, Solvig; Zachert, Kerstin; Raiss, Patric; Richter, Wiltrud

    2014-01-01

    Main objective was to investigate whether the synthetic retinoic acid receptor (RAR)-β antagonist LE135 is able to drive in vitro chondrogenesis of human mesenchymal stromal cells (MSCs) or improve differentiation by suppressing hypertrophic chondrocyte development. Chondrogenesis of human bone marrow and adipose tissue-derived MSCs was induced in micromass pellet culture for six weeks. Effects of LE135 alone and in combinatorial treatment with TGF-β on deposition of cartilaginous matrix including collagen type II and glycosaminoglycans, on deposition of non-hyaline cartilage collagens type I and X, and on hypertrophy markers including alkaline phosphatase (ALP), indian hedghehog (IHH) and matrix metalloproteinase (MMP)-13 were assessed. LE135 was no inducer of chondrogenesis and failed to stimulate deposition of collagen type II and glycosaminoglycans. Moreover, addition of LE135 to TGF-β-treated pellets inhibited cartilaginous matrix deposition and gene expression of COL2A1. In contrast, non-hyaline cartilage collagens were less sensitive to LE135 and hypertrophy markers remained unaffected. This demonstrates a differential sensitivity of chondral versus endochondral differentiation pathways to RARβ signaling; however, opposite to the desired direction. The relevance of trans-activating versus trans-repressing RAR signaling, including effects on activator protein (AP)-1 is discussed and implications for overcoming current limits of hMSC chondrogenesis are considered. © 2014 S. Karger AG, Basel.

  11. Effect of cartilaginous matrix components on the chondrogenesis and hypertrophy of mesenchymal stem cells in hyaluronic acid hydrogels.

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    Zhu, Meiling; Feng, Qian; Sun, Yuxin; Li, Gang; Bian, Liming

    2017-11-01

    The microenvironment of the extracellular matrix (ECM) plays a key role in directing the viability and subsequent differentiation of the encapsulated stem cells by the specific integration between the hydrated biomolecules and cell surface receptors. Herein, we developed a hydrogel platform based on hyaluronic acid (HA) that presents cartilage ECM molecules as a form of developmental cues. The hybrid hydrogels were generated by coupling photo-cross-linkable methacrylated HA (MeHA) with selected cartilaginous ECM molecules including chondroitin sulfate (CS) and type I collagen (Col I), and we studied the decoupled function of these cues in regulating the initial chondrogenesis, subsequent hypertrophy, and tissue mineralization by hMSCs. The results indicate upregulated mRNA expression of the chondrogenesis markers in the HA hydrogels that contain Col I or CS, and decreased expression of the hypertrophic markers compared with the control MeHA group. The quantification results also show that glycosaminoglycans accumulation increases in the hybrid hydrogels containing cartilaginous ECM molecules, both in vitro and in vivo. We hypothesize that these additional ECM components in the HA hydrogels further regulate the hMSCs chondrogenesis and hypertrophy by coordination. The understanding obtained in this study may guide biomaterial scaffold design, thereby facilitating manipulation of the differentiation and mineralization of induced hMSCs for application in the repair of different musculoskeletal defects. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 2292-2300, 2017. © 2016 Wiley Periodicals, Inc.

  12. The immediate early gene product EGR1 and polycomb group proteins interact in epigenetic programming during chondrogenesis.

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    Frank Spaapen

    Full Text Available Initiation of and progression through chondrogenesis is driven by changes in the cellular microenvironment. At the onset of chondrogenesis, resting mesenchymal stem cells are mobilized in vivo and a complex, step-wise chondrogenic differentiation program is initiated. Differentiation requires coordinated transcriptomic reprogramming and increased progenitor proliferation; both processes require chromatin remodeling. The nature of early molecular responses that relay differentiation signals to chromatin is poorly understood. We here show that immediate early genes are rapidly and transiently induced in response to differentiation stimuli in vitro. Functional ablation of the immediate early factor EGR1 severely deregulates expression of key chondrogenic control genes at the onset of differentiation. In addition, differentiating cells accumulate DNA damage, activate a DNA damage response and undergo a cell cycle arrest and prevent differentiation associated hyper-proliferation. Failed differentiation in the absence of EGR1 affects global acetylation and terminates in overall histone hypermethylation. We report novel molecular connections between EGR1 and Polycomb Group function: Polycomb associated histone H3 lysine27 trimethylation (H3K27me3 blocks chromatin access of EGR1. In addition, EGR1 ablation results in abnormal Ezh2 and Bmi1 expression. Consistent with this functional interaction, we identify a number of co-regulated targets genes in a chondrogenic gene network. We here describe an important role for EGR1 in early chondrogenic epigenetic programming to accommodate early gene-environment interactions in chondrogenesis.

  13. Interplay between stiffness and degradation of architectured gelatin hydrogels leads to differential modulation of chondrogenesis in vitro and in vivo.

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    Sarem, Melika; Arya, Neha; Heizmann, Miriam; Neffe, Axel T; Barbero, Andrea; Gebauer, Tim P; Martin, Ivan; Lendlein, Andreas; Shastri, V Prasad

    2018-03-15

    paradigms were explored (i) ex vivo engineering followed by in vivo implantation in ectopic site of nude mice and (ii) short in vitro culture (3 days) followed by implantation to induce de novo cartilage formation. Softer and fast degrading ArcGel were better at promoting chondrogenesis in vitro, while stiffer and slow degrading ArcGel were strikingly superior in both maintaining chondrogenesis in vivo and inducing de novo formation of cartilage. Our findings highlight the importance of the interplay between scaffold mechanics and degradation in chondrogenesis. Copyright © 2018 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  14. Arterial injury promotes medial chondrogenesis in Sm22 knockout mice.

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    Shen, Jianbin; Yang, Maozhou; Jiang, Hong; Ju, Donghong; Zheng, Jian-Pu; Xu, Zhonghui; Liao, Tang-Dong; Li, Li

    2011-04-01

    Expression of SM22 (also known as SM22alpha and transgelin), a vascular smooth muscle cells (VSMCs) marker, is down-regulated in arterial diseases involving medial osteochondrogenesis. We investigated the effect of SM22 deficiency in a mouse artery injury model to determine the role of SM22 in arterial chondrogenesis. Sm22 knockout (Sm22(-/-)) mice developed prominent medial chondrogenesis 2 weeks after carotid denudation as evidenced by the enhanced expression of chondrogenic markers including type II collagen, aggrecan, osteopontin, bone morphogenetic protein 2, and SRY-box containing gene 9 (SOX9). This was concomitant with suppression of VSMC key transcription factor myocardin and of VSMC markers such as SM α-actin and myosin heavy chain. The conversion tendency from myogenesis to chondrogenesis was also observed in primary Sm22(-/-) VSMCs and in a VSMC line after Sm22 knockdown: SM22 deficiency altered VSMC morphology with compromised stress fibre formation and increased actin dynamics. Meanwhile, the expression level of Sox9 mRNA was up-regulated while the mRNA levels of myocardin and VSMC markers were down-regulated, indicating a pro-chondrogenic transcriptional switch in SM22-deficient VSMCs. Furthermore, the increased expression of SOX9 was mediated by enhanced reactive oxygen species production and nuclear factor-κB pathway activation. These findings suggest that disruption of SM22 alters the actin cytoskeleton and promotes chondrogenic conversion of VSMCs.

  15. CCN4/WISP-1 positively regulates chondrogenesis by controlling TGF-β3 function.

    Science.gov (United States)

    Yoshioka, Yuya; Ono, Mitsuaki; Maeda, Azusa; Kilts, Tina M; Hara, Emilio Satoshi; Khattab, Hany; Ueda, Junji; Aoyama, Eriko; Oohashi, Toshitaka; Takigawa, Masaharu; Young, Marian F; Kuboki, Takuo

    2016-02-01

    The CCN family of proteins plays important roles in development and homeostasis of bone and cartilage. To understand the role of CCN4 in chondrogenesis, human bone marrow stromal cells (hBMSCs) were transduced with CCN4 adenovirus (adCCN4) or siRNA to CCN4 (siCCN4) in the presence or absence of transforming growth factor-β3 (TGF-β3). Overexpression of CCN4 enhanced TGF-β3-induced SMAD2/3 phosphorylation and chondrogenesis of hBMSCs in an in vitro assay using a micromass culture model. On the other hand, knockdown of CCN4 inhibited the TGF-β3-induced SMAD2/3 phosphorylation and synthesis of cartilage matrix in micromass cultures of hBMSCs. Immunoprecipitation-western blot analysis revealed that CCN4 bound to TGF-β3 and regulated the ability of TGF-β3 to bind to hBMSCs. In vivo analysis confirmed there was a significant decrease in the gene expression levels of chondrocyte markers in cartilage samples from Ccn4-knock out (KO) mice, compared to those from wild type (WT) control. In order to investigate the regenerative properties of the articular cartilage in Ccn4-KO mice, articular cartilage defects were surgically performed in the knee joints of young mice, and the results showed that the cartilage was partially repaired in WT mice, but not in Ccn4-KO mice. In conclusion, these results show, for the first time, that CCN4 has a positive influence on chondrogenic differentiation by modulating the effects of TGF-β3. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. Microscale versus nanoscale scaffold architecture for mesenchymal stem cell chondrogenesis.

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    Shanmugasundaram, Shobana; Chaudhry, Hans; Arinzeh, Treena Livingston

    2011-03-01

    Nanofiber scaffolds, produced by the electrospinning technique, have gained widespread attention in tissue engineering due to their morphological similarities to the native extracellular matrix. For cartilage repair, studies have examined their feasibility; however these studies have been limited, excluding the influence of other scaffold design features. This study evaluated the effect of scaffold design, specifically examining a range of nano to micron-sized fibers and resulting pore size and mechanical properties, on human mesenchymal stem cells (MSCs) derived from the adult bone marrow during chondrogenesis. MSC differentiation was examined on these scaffolds with an emphasis on temporal gene expression of chondrogenic markers and the pluripotent gene, Sox2, which has yet to be explored for MSCs during chondrogenesis and in combination with tissue engineering scaffolds. Chondrogenic markers of aggrecan, chondroadherin, sox9, and collagen type II were highest for cells on micron-sized fibers (5 and 9 μm) with pore sizes of 27 and 29 μm, respectively, in comparison to cells on nano-sized fibers (300 nm and 600 to 1400 nm) having pore sizes of 2 and 3 μm, respectively. Undifferentiated MSCs expressed high levels of the Sox2 gene but displayed negligible levels on all scaffolds with or without the presence of inductive factors, suggesting that the physical features of the scaffold play an important role in differentiation. Micron-sized fibers with large pore structures and mechanical properties comparable to the cartilage ECM enhanced chondrogenesis, demonstrating architectural features as well as mechanical properties of electrospun fibrous scaffolds enhance differentiation.

  17. Chondrogenesis in scleral stem/progenitor cells and its association with form-deprived myopia in mice.

    Science.gov (United States)

    Wu, Pei-Chang; Tsai, Chia-Ling; Gordon, Gabriel M; Jeong, Shinwu; Itakura, Tatsuo; Patel, Nitin; Shi, Songtao; Fini, M Elizabeth

    2015-01-01

    Previously, we demonstrated that scleral stem/progenitor cells (SSPCs) from mice have a chondrogenic differentiation potential, which is stimulated by transforming growth factor-β (TGF-β). In the present study, we hypothesized that chondrogenesis in the sclera could be a possible mechanism in myopia development. Therefore, we investigated the association of form-deprivation myopia (FDM) with expressions in mice sclera representing the chondrogenic phenotype: collagen type II (Col2) and α-smooth muscle actin (α-SMA). The mRNA levels of α-SMA and Col2 in cultured murine SSPCs during chondrogenesis stimulated by TGF-β2 were determined by real-time quantitative RT-PCR (qRT-PCR). The expression patterns of α-SMA and Col2 were assessed by immunohistochemistry in a three dimensional pellet culture. In an FDM mouse model, a western blot analysis and immunofluorescence study were used to detect the changes in the α-SMA and Col2 protein expressions in the sclera. In the RPE-choroid complex, qRT-PCR was used to detect any changes in the TGF-β mRNA expression. The treatment of SSPCs in vitro with TGF-β2 for 24 h at 1 or 10 ng/ml led to increased levels of both the α-SMA and Col2 expressions. In addition, we observed the formation of cartilage-like pellets from TGF-β2-treated SSPCs. Both α-SMA and Col2 were expressed in the pellet. In an in-vivo study, the α-SMA and Col2 protein expressions were significantly increased in the sclera of FDM eyes in comparison to contralateral control eyes. Similarly, the levels of TGF-β in the RPE-choroid complex of an FDM eye were also significantly elevated. Based on the concept of stem cells possessing multipotent differentiation potentials, scleral chondrogenesis induced by SSPCs may play a role in myopia development. The increased expressions of the cartilage-associated proteins Col2 and α-SMA during scleral chondrogenesis may be potential markers for myopia development. In addition, the increased levels of TGF-β mRNA in

  18. Enhance and Maintain Chondrogenesis of Synovial Fibroblasts by Cartilage Extracellular Matrix Protein Matrilins

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    Pei, Ming; Luo, Junming; Chen, Qian

    2008-01-01

    Summary Objective Cartilage-specific extracellular matrix (ECM) proteins have been proposed to play key roles in modulating cellular phenotypes during chondrogenesis of mesenchymal stem cells. Matrilin (MATN) 1 and 3 are among the most up-regulated ECM proteins during chondrogenesis. The aim of this study was to analyze their roles in chondrogenesis of mesenchymal fibroblasts from synovium. Methods Primary synovial fibroblasts (SFBs) were purified from porcine synovium and incubated in pellet culture for 18 days. Chondrogenesis of SFB was analyzed by histological staining with safranin-O/fast green, and by quantifying glycosaminoglycans with dimethylmethylene blue assay. The mRNA levels of chondrogenic markers including collagen II, aggrecan, and Sox 9 were quantified by real-time RT-PCR, while the protein levels of Col II and matrilins were determined by western blot analysis. Results SFBs underwent chondrogenesis after incubation with TGF-β1 for three days; however, this process was attenuated during the subsequent incubation period. Expression of a MATN1 or 3 cDNA maintained and further enhanced chondrogenesis of SFBs as shown by increased cartilaginous matrix areas, elevated amount of glycosaminoglycans, and stimulated expression of chondrogenic markers. Conclusion Our findings suggest a novel function for MATN1 and 3 to maintain and enhance chondrogenesis of mesenchymal fibroblasts initiated by TGF-β. Our results also support a critical role of cartilage-specific ECM proteins to modulate cellular phenotypes in the microenvironment during chondrogenic differentiation. PMID:18282772

  19. Enhancing and maintaining chondrogenesis of synovial fibroblasts by cartilage extracellular matrix protein matrilins.

    Science.gov (United States)

    Pei, M; Luo, J; Chen, Q

    2008-09-01

    Cartilage-specific extracellular matrix (ECM) proteins have been proposed to play key roles in modulating cellular phenotypes during chondrogenesis of mesenchymal stem cells. Matrilin (MATN)1 and MATN3 are among the most up-regulated ECM proteins during chondrogenesis. The aim of this study was to analyze their roles in chondrogenesis of mesenchymal fibroblasts from synovium. Primary synovial fibroblasts (SFBs) were purified from porcine synovium and incubated in pellet culture for 18 days. Chondrogenesis of SFB was analyzed by histological staining with safranin-O/fast green, and by quantifying glycosaminoglycans (GAG) with dimethylmethylene blue assay. The mRNA levels of chondrogenic markers including collagen II, aggrecan, and Sox 9 were quantified by real-time reverse transcription polymerase chain reaction, while the protein levels of Col II and MATNs were determined by western blot analysis. SFBs underwent chondrogenesis after incubation with transforming growth factor-beta1 (TGF-beta1) for 3 days; however, this process was attenuated during the subsequent incubation period. Expression of a Matn1 or Matn3 cDNA maintained and further enhanced chondrogenesis of SFBs as shown by increased cartilaginous matrix areas, elevated amount of GAG, and stimulated expression of chondrogenic markers. Our findings suggest a novel function for MATN1 and MATN3 to maintain and enhance chondrogenesis of mesenchymal fibroblasts initiated by TGF-beta. Our results also support a critical role of cartilage-specific ECM proteins to modulate cellular phenotypes in the microenvironment during chondrogenic differentiation.

  20. Hydrophilic polyurethane matrix promotes chondrogenesis of mesenchymal stem cells☆

    Science.gov (United States)

    Nalluri, Sandeep M.; Krishnan, G. Rajesh; Cheah, Calvin; Arzumand, Ayesha; Yuan, Yuan; Richardson, Caley A.; Yang, Shuying; Sarkar, Debanjan

    2016-01-01

    Segmental polyurethanes exhibit biphasic morphology and can control cell fate by providing distinct matrix guided signals to increase the chondrogenic potential of mesenchymal stem cells (MSCs). Polyethylene glycol (PEG) based hydrophilic polyurethanes can deliver differential signals to MSCs through their matrix phases where hard segments are cell-interactive domains and PEG based soft segments are minimally interactive with cells. These coordinated communications can modulate cell–matrix interactions to control cell shape and size for chondrogenesis. Biphasic character and hydrophilicity of polyurethanes with gel like architecture provide a synthetic matrix conducive for chondrogenesis of MSCs, as evidenced by deposition of cartilage-associated extracellular matrix. Compared to monophasic hydrogels, presence of cell interactive domains in hydrophilic polyurethanes gels can balance cell–cell and cell–matrix interactions. These results demonstrate the correlation between lineage commitment and the changes in cell shape, cell–matrix interaction, and cell–cell adhesion during chondrogenic differentiation which is regulated by polyurethane phase morphology, and thus, represent hydrophilic polyurethanes as promising synthetic matrices for cartilage regeneration. PMID:26046282

  1. Hydrophilic polyurethane matrix promotes chondrogenesis of mesenchymal stem cells.

    Science.gov (United States)

    Nalluri, Sandeep M; Krishnan, G Rajesh; Cheah, Calvin; Arzumand, Ayesha; Yuan, Yuan; Richardson, Caley A; Yang, Shuying; Sarkar, Debanjan

    2015-09-01

    Segmental polyurethanes exhibit biphasic morphology and can control cell fate by providing distinct matrix guided signals to increase the chondrogenic potential of mesenchymal stem cells (MSCs). Polyethylene glycol (PEG) based hydrophilic polyurethanes can deliver differential signals to MSCs through their matrix phases where hard segments are cell-interactive domains and PEG based soft segments are minimally interactive with cells. These coordinated communications can modulate cell-matrix interactions to control cell shape and size for chondrogenesis. Biphasic character and hydrophilicity of polyurethanes with gel like architecture provide a synthetic matrix conducive for chondrogenesis of MSCs, as evidenced by deposition of cartilage-associated extracellular matrix. Compared to monophasic hydrogels, presence of cell interactive domains in hydrophilic polyurethanes gels can balance cell-cell and cell-matrix interactions. These results demonstrate the correlation between lineage commitment and the changes in cell shape, cell-matrix interaction, and cell-cell adhesion during chondrogenic differentiation which is regulated by polyurethane phase morphology, and thus, represent hydrophilic polyurethanes as promising synthetic matrices for cartilage regeneration. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Concave microwell plate facilitates chondrogenesis from mesenchymal stem cells.

    Science.gov (United States)

    Ko, Ji-Yun; Im, Gun-Il

    2016-11-01

    To compare in vitro chondrogenesis from bone marrow-derived mesenchymal stem cells using concave microwell plates with those obtained using culture tubes. Pellets cultured in concave microwell plates had a significantly higher level of GAG per DNA content and greater proteoglycan content than those cultured in tubes at day 7 and 14. Three chondrogenic markers, SOX-9, COL2A1 and aggrecan, showed significantly higher expression in pellets cultured in concave microwell plates than those cultured in tubes at day 7 and 14. At day 21, there was not a significant difference in the expression of these markers. COL10A1, the typical hypertrophy marker, was significantly lower in concave microwell plates during the whole culture period. Runx-2, a marker of hypertrophy and osteogenesis, was significantly lower at day 7 in pellets cultured in concave microwell plates than those cultured in tubes. Concave microwell plates provide a convenient and effective tool for the study of in vitro chondrogenesis and may replace the use of propylene culture tube.

  3. CD14-negative isolation enhances chondrogenesis in synovial fibroblasts.

    Science.gov (United States)

    Bilgen, Bahar; Ren, Yuexin; Pei, Ming; Aaron, Roy K; Ciombor, Deborah McK

    2009-11-01

    Synovial membrane has been shown to contain mesenchymal stem cells. We hypothesized that an enriched population of synovial fibroblasts would undergo chondrogenic differentiation and secrete cartilage extracellular matrix to a greater extent than would a mixed synovial cell population (MSCP). The optimum doses of transforming growth factor beta 1 (TGF-beta1) and insulin-like growth factor 1 (IGF-1) for chondrogenesis were investigated. CD14-negative isolation was used to obtain a porcine cell population enriched in type-B synovial fibroblasts (SFB) from an MSCP. The positive cell surface markers in SFB were CD90, CD44, and cadherin-11. SFB and MSCP were cultured in the presence of 20 ng/mL TGF-beta1 for 7 days, and SFB were demonstrated to have higher chondrogenic potential. Further dose-response studies were carried out using the SFB cells and several doses of TGF-beta1 (2, 10, 20, and 40 ng/mL) and/or IGF-1 (1, 10, 100, and 500 ng/mL) for 14 days. TGF-beta1 supplementation was essential for chondrogenesis and prevention of cell death, whereas IGF-1 did not have a significant effect on the SFB cell number or glycosaminoglycan production. This study demonstrates that the CD14-negative isolation yields an enhanced cell population SFB that is more potent than MSCP as a cell source for cartilage tissue engineering.

  4. Rescue of proinflammatory cytokine-inhibited chondrogenesis by the antiarthritic effect of melatonin in synovium mesenchymal stem cells via suppression of reactive oxygen species and matrix metalloproteinases.

    Science.gov (United States)

    Liu, Xiaozhen; Xu, Yong; Chen, Sijin; Tan, Zifang; Xiong, Ke; Li, Yan; Ye, Yun; Luo, Zong-Ping; He, Fan; Gong, Yihong

    2014-03-01

    Cartilage repair by mesenchymal stem cells (MSCs) often occurs in diseased joints in which the inflamed microenvironment impairs chondrogenic maturation and causes neocartilage degradation. In this environment, melatonin exerts an antioxidant effect by scavenging free radicals. This study aimed to investigate the anti-inflammatory and chondroprotective effects of melatonin on human MSCs in a proinflammatory cytokine-induced arthritic environment. MSCs were induced toward chondrogenesis in the presence of interleukin-1β (IL-1β) or tumor necrosis factor α (TNF-α) with or without melatonin. Levels of intracellular reactive oxygen species (ROS), hydrogen peroxide, antioxidant enzymes, and cell viability were then assessed. Deposition of glycosaminoglycans and collagens was also determined by histological analysis. Gene expression of chondrogenic markers and matrix metalloproteinases (MMPs) was assessed by real-time polymerase chain reaction. In addition, the involvement of the melatonin receptor and superoxide dismutase (SOD) in chondrogenesis was investigated using pharmacologic inhibitors. The results showed that melatonin significantly reduced ROS accumulation and increased SOD expression. Both IL-1β and TNF-α had an inhibitory effect on the chondrogenesis of MSCs, but melatonin successfully restored the low expression of cartilage matrix and chondrogenic genes. Melatonin prevented cartilage degradation by downregulating MMPs. The addition of luzindole and SOD inhibitors abrogated the protective effect of melatonin associated with increased levels of ROS and MMPs. These results demonstrated that proinflammatory cytokines impair the chondrogenesis of MSCs, which was rescued by melatonin treatment. This chondroprotective effect was potentially correlated to decreased ROS, preserved SOD, and suppressed levels of MMPs. Thus, melatonin provides a new strategy for promoting cell-based cartilage regeneration in diseased or injured joints. Copyright © 2013 Elsevier

  5. Catabolic factors and osteoarthritis-conditioned medium inhibit chondrogenesis of human mesenchymal stem cells.

    Science.gov (United States)

    Heldens, Genoveva T H; Blaney Davidson, Esmeralda N; Vitters, Elly L; Schreurs, B Willem; Piek, Ester; van den Berg, Wim B; van der Kraan, Peter M

    2012-01-01

    Articular cartilage has a very limited intrinsic repair capacity leading to progressive joint damage. Therapies involving tissue engineering depend on chondrogenic differentiation of progenitor cells. This chondrogenic differentiation will have to survive in a diseased joint. We postulate that catabolic factors in this environment inhibit chondrogenesis of progenitor cells. We investigated the effect of a catabolic environment on chondrogenesis in pellet cultures of human mesenchymal stem cells (hMSCs). We exposed chondrogenically differentiated hMSC pellets, to interleukin (IL)-1α, tumor necrosis factor (TNF)-α or conditioned medium derived from osteoarthritic synovium (CM-OAS). IL-1α and TNF-α in CM-OAS were blocked with IL-1Ra or Enbrel, respectively. Chondrogenesis was determined by chondrogenic markers collagen type II, aggrecan, and the hypertrophy marker collagen type X on mRNA. Proteoglycan deposition was analyzed by safranin o staining on histology. IL-1α and TNF-α dose-dependently inhibited chondrogenesis when added at onset or during progression of differentiation, IL-1α being more potent than TNF-α. CM-OAS inhibited chondrogenesis on mRNA and protein level but varied in extent between patients. Inhibition of IL-1α partially overcame the inhibitory effect of the CM-OAS on chondrogenesis whereas the TNF-α contribution was negligible. We show that hMSC chondrogenesis is blocked by either IL-1α or TNF-α alone, but that there are additional factors present in CM-OAS that contribute to inhibition of chondrogenesis, demonstrating that catabolic factors present in OA joints inhibit chondrogenesis, thereby impairing successful tissue engineering.

  6. Chondrogenesis of human bone marrow mesenchymal stromal cells in highly porous alginate-foams supplemented with chondroitin sulfate

    International Nuclear Information System (INIS)

    Huang, Zhao; Nooeaid, Patcharakamon; Kohl, Benjamin; Roether, Judith A.; Schubert, Dirk W.; Meier, Carola; Boccaccini, Aldo R.; Godkin, Owen; Ertel, Wolfgang; Arens, Stephan; Schulze-Tanzil, Gundula

    2015-01-01

    To overcome the limited intrinsic cartilage repair, autologous chondrocyte or bone-marrow-derived mesenchymal stromal cell (BM-MSC) was implanted into cartilage defects. For this purpose suitable biocompatible scaffolds are needed to provide cell retention, chondrogenesis and initial mechanical stability. The present study should indicate whether a recently developed highly porous alginate (Alg) foam scaffold supplemented with chondroitin sulfate (CS) allows the attachment, survival and chondrogenesis of BM-MSCs and articular chondrocytes. The foams were prepared using a freeze-drying method; some of them were supplemented with CS and subsequently characterized for porosity, biodegradation and mechanical profile. BM-MSCs were cultured for 1–2 weeks on the scaffold either under chondrogenic or maintenance conditions. Cell vitality assays, histology, glycosaminoglycan (sGAG) assay, and type II and I collagen immunolabelings were performed to monitor cell growth and extracellular matrix (ECM) synthesis in the scaffolds. Scaffolds had a high porosity ~ 93–95% with a mean pore sizes of 237 ± 48 μm (Alg) and 197 ± 61 μm (Alg/CS). Incorporation of CS increased mechanical strength of the foams providing gradually CS release over 7 days. Most of the cells survived in the scaffolds. BM-MSCs and articular chondrocytes formed rounded clusters within the scaffold pores. The BM-MSCs, irrespective of whether cultured under non/chondrogenic conditions and chondrocytes produced an ECM containing sGAGs, and types II and I collagen. Total collagen and sGAG contents were higher in differentiated BM-MSC cultures supplemented with CS than in CS-free foams after 14 days. The cell cluster formation induced by the scaffolds might stimulate chondrogenesis via initial intense cell–cell contacts. - Highlights: • Alginate foam scaffolds revealed a high porosity and mean pore size of 197–237 μm. • Chondroitin sulfate was released over 14 days by the scaffolds. • Chondrocytes

  7. Chondrogenesis of human bone marrow mesenchymal stromal cells in highly porous alginate-foams supplemented with chondroitin sulfate

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Zhao [Department of Orthopaedic, Trauma and Reconstructive Surgery, Charité-Universitätsmedizin-Berlin Campus Benjamin Franklin, Berlin (Germany); Nooeaid, Patcharakamon [Institute of Biomaterials, Department of Materials Science and Engineering, University of Erlangen-Nuremberg (Germany); Kohl, Benjamin [Department of Orthopaedic, Trauma and Reconstructive Surgery, Charité-Universitätsmedizin-Berlin Campus Benjamin Franklin, Berlin (Germany); Roether, Judith A.; Schubert, Dirk W. [Institute of Polymer Materials, Department of Materials Science and Engineering, University of Erlangen-Nuremberg (Germany); Meier, Carola [Department of Orthopaedic, Trauma and Reconstructive Surgery, Charité-Universitätsmedizin-Berlin Campus Benjamin Franklin, Berlin (Germany); Boccaccini, Aldo R. [Institute of Biomaterials, Department of Materials Science and Engineering, University of Erlangen-Nuremberg (Germany); Godkin, Owen; Ertel, Wolfgang; Arens, Stephan [Department of Orthopaedic, Trauma and Reconstructive Surgery, Charité-Universitätsmedizin-Berlin Campus Benjamin Franklin, Berlin (Germany); Schulze-Tanzil, Gundula, E-mail: gundula.schulze@pmu.ac.at [Department of Orthopaedic, Trauma and Reconstructive Surgery, Charité-Universitätsmedizin-Berlin Campus Benjamin Franklin, Berlin (Germany); Institute of Anatomy, Paracelsus Medical University, Nuremberg (Germany)

    2015-05-01

    To overcome the limited intrinsic cartilage repair, autologous chondrocyte or bone-marrow-derived mesenchymal stromal cell (BM-MSC) was implanted into cartilage defects. For this purpose suitable biocompatible scaffolds are needed to provide cell retention, chondrogenesis and initial mechanical stability. The present study should indicate whether a recently developed highly porous alginate (Alg) foam scaffold supplemented with chondroitin sulfate (CS) allows the attachment, survival and chondrogenesis of BM-MSCs and articular chondrocytes. The foams were prepared using a freeze-drying method; some of them were supplemented with CS and subsequently characterized for porosity, biodegradation and mechanical profile. BM-MSCs were cultured for 1–2 weeks on the scaffold either under chondrogenic or maintenance conditions. Cell vitality assays, histology, glycosaminoglycan (sGAG) assay, and type II and I collagen immunolabelings were performed to monitor cell growth and extracellular matrix (ECM) synthesis in the scaffolds. Scaffolds had a high porosity ~ 93–95% with a mean pore sizes of 237 ± 48 μm (Alg) and 197 ± 61 μm (Alg/CS). Incorporation of CS increased mechanical strength of the foams providing gradually CS release over 7 days. Most of the cells survived in the scaffolds. BM-MSCs and articular chondrocytes formed rounded clusters within the scaffold pores. The BM-MSCs, irrespective of whether cultured under non/chondrogenic conditions and chondrocytes produced an ECM containing sGAGs, and types II and I collagen. Total collagen and sGAG contents were higher in differentiated BM-MSC cultures supplemented with CS than in CS-free foams after 14 days. The cell cluster formation induced by the scaffolds might stimulate chondrogenesis via initial intense cell–cell contacts. - Highlights: • Alginate foam scaffolds revealed a high porosity and mean pore size of 197–237 μm. • Chondroitin sulfate was released over 14 days by the scaffolds. • Chondrocytes

  8. Optimal construction and delivery of dual-functioning lentiviral vectors for type I collagen-suppressed chondrogenesis in synovium-derived mesenchymal stem cells.

    Science.gov (United States)

    Zhang, Feng; Yao, Yongchang; Zhou, Ruijie; Su, Kai; Citra, Fudiman; Wang, Dong-An

    2011-06-01

    This study aims to deliver both transforming growth factor β3 (TGF-β3) and shRNA targeting type I collagen (Col I) by optimal construction and application of various dual-functioning lentiviral vectors to induce Col I-suppressed chondrogenesis in synovium-derived mesenchymal stem cells (SMSCs). We constructed four lentiviral vectors (LV-1, LV-2, LV-3 and LV-4) with various arrangements of the two expression cassettes in different positions and orientations. Col I inhibition efficiency and chondrogenic markers were assessed with qPCR, ELISA and staining techniques. Among the four vectors, LV-1 has two distant and reversely oriented cassettes, LV-2 has two distant and same-oriented cassettes, LV-3 has two proximal and reversely oriented cassettes, and LV-4 has two proximal and same-oriented cassettes. Col I and chondrogenic markers, including type II collagen (Col II), aggrecan and glycosaminoglycan (GAG), were examined in SMSCs cultured in 3-D alginate hydrogel. All of the four vectors showed distinct effects in Col I level as well as diverse inductive efficiencies in upregulation of the cartilaginous markers. Based on real-time PCR results, LV-1 was optimal towards Col I-suppressed chondrogenesis. LV-1 vector is competent to promote Col I-suppressed chondrogenesis in SMSCs.

  9. [Molecular cloning, expression of rat Msx-1 and Msx-2 during early embryo genesis and roles for mandibular chondrogenesis].

    Science.gov (United States)

    Ishiguro, S

    1999-03-01

    Quail-chick chimera experiments have shown a contribution of carnial neural crest cells to the craniofacial skeletal elements. Moreover, tissue interactions between epithelial-mesenchymal interaction during early facial process development are required for both skeletal differentiation and morphogenesis. In this study, it was observed that Msx homeobox containing genes expressed in the facial process were important molecules of cartilage morphogenesis. Rat cDNAs were isolated and encoded by Msx-1 and -2, and then the expression patterns using in situ hybridization were investigated during early rat face development. These genes were correlatively expressed in the cranial neural crest forming area (E 9.5 dpc) and the facial process (E 12.5 dpc). Antisence inhibition of Msx genes in the E 12.5 mandibular process exhibited the alteration of their gene expression and cartilage patterns. Antisence inhibition of Msx-1 induced lack of the medial portion of cartilage, and antisence inhibition of Msx-2 enhanced chondrogenesis of mandibular process under the organ culture condition. Thus it was concluded that expression of Msx genes during mandibular process development comprises important signals of chondrogenesis.

  10. Chondroblastoma and chondromyxoid fibroma : disentangling the neoplastic chondrogenesis of two rare cartilaginous tumours

    NARCIS (Netherlands)

    Romeo, Salvatore

    2010-01-01

    The scope of this study was to disentangle neoplastic chondrogenesis in two rare cartilaginous tumours: chondroblastoma and chondromyxoid fibroma. It was addressed: 1 The spectrum of phenotypic differentiation in chondroblastoma and chondromyxoid fibroma, 2 The signalling pathways driving

  11. Optimizing a novel method for low intensity ultrasound in chondrogenesis induction

    Directory of Open Access Journals (Sweden)

    Hajar Shafaei

    2013-01-01

    Conclusion: Using LIUS resulted in early chondrogenesis in comparison with terminally differentiated chondrocytes by TGFβ. Therefore, LIUS might provide an applicable, safe, efficient, and cheap tool for chondrogenic differentiation of ASCs in cartilage tissue engineering.

  12. Effect of Fibroblast Growth Factor 2 on Equine Synovial Fluid Chondroprogenitor Expansion and Chondrogenesis

    OpenAIRE

    Bianchessi, Marta; Chen, Yuwen; Durgam, Sushmitha; Pondenis, Holly; Stewart, Matthew

    2015-01-01

    Mesenchymal stem cells have been identified in the synovial fluid of several species. This study was conducted to characterize chondroprogenitor (CP) cells in equine synovial fluid (SF) and to determine the effect of fibroblast growth factor 2 (FGF-2) on SF-CP monolayer proliferation and subsequent chondrogenesis. We hypothesized that FGF-2 would stimulate SF-CP proliferation and postexpansion chondrogenesis. SF aspirates were collected from adult equine joints. Colony-forming unit (CFU) assa...

  13. Electrical stimulation drives chondrogenesis of mesenchymal stem cells in the absence of exogenous growth factors

    OpenAIRE

    Hyuck Joon Kwon; Gyu Seok Lee; Honggu Chun

    2016-01-01

    Electrical stimulation (ES) is known to guide the development and regeneration of many tissues. However, although preclinical and clinical studies have demonstrated superior effects of ES on cartilage repair, the effects of ES on chondrogenesis remain elusive. Since mesenchyme stem cells (MSCs) have high therapeutic potential for cartilage regeneration, we investigated the actions of ES during chondrogenesis of MSCs. Herein, we demonstrate for the first time that ES enhances expression levels...

  14. Bone morphogenetic protein-7 promotes chondrogenesis in human amniotic epithelial cells.

    Science.gov (United States)

    Zhou, Junjie; Yu, Guangrong; Cao, Chengfu; Pang, Jinhui; Chen, Xianqi

    2011-06-01

    Bone morphogenetic proteins (BMPs) play important roles at multiple stages of chondrogenesis. This study was undertaken to investigate the potential role of bone morphogenetic protein-7 (BMP-7) in the differentiation of chondrocytes using tissue engineering techniques. The impact of BMP-7 on human amniotic epithelial cells (hAECs) was tested. The hAECs were treated either with recombinant human BMP-7 cDNA or with transforming growth factor beta 1 (TGF-β1) as a positive control for three weeks in vitro. Cartilaginous differentiation and proliferation were assayed by quantitative RT-PCR, histology, and in situ hybridization. Our results were such that hAECs treated with either BMP-7 or TGF-β1 expressed cartilage markers (aggrecan, Sox9, CEP-68, and type II and X collagens) within three weeks. Compared with a control vector, BMP-7 induced a decrease in type I collagen expression, while the transcription of the cartilage-specific type II collagen remained stable. In induction experiments, BMP-7 transgenic hAECs exhibited the largest amount of matrix synthesis. In conclusion, these data indicate that BMP-7 plays an important role in inducing the production of cartilage by hAECs in vitro. Cartilage differentiation and matrix maturation can be promoted by BMPs in a cartilage engineering paradigm. These properties make BMPs promising tools in the engineering of cartilaginous joint bio-prostheses and as candidate biological agents or genes for cartilage stabilisation.

  15. Human Umbilical Cord Blood-Derived Mesenchymal Stem Cells Contribute to Chondrogenesis in Coculture with Chondrocytes.

    Science.gov (United States)

    Li, Xingfu; Duan, Li; Liang, Yujie; Zhu, Weimin; Xiong, Jianyi; Wang, Daping

    2016-01-01

    Human umbilical cord blood-derived mesenchymal stem cells (hUCB-MSCs) have been shown as the most potential stem cell source for articular cartilage repair. In this study, we aimed to develop a method for long-term coculture of human articular chondrocytes (hACs) and hUCB-MSCs at low density in vitro to determine if the low density of hACs could enhance the hUCB-MSC chondrogenic differentiation as well as to determine the optimal ratio of the two cell types. Also, we compared the difference between direct coculture and indirect coculture at low density. Monolayer cultures of hUCB-MSCs and hACs were investigated at different ratios, at direct cell-cell contact groups for 21 days. Compared to direct coculture, hUCB-MSCs and hACs indirect contact culture significantly increased type II collagen (COL2) and decreased type I collagen (COL1) protein expression levels. SRY-box 9 (SOX9) mRNA levels and protein expression were highest in indirect coculture. Overall, these results indicate that low density direct coculture induces fibrocartilage. However, indirect coculture in conditioned chondrocyte cell culture medium can increase expression of chondrogenic markers and induce hUCB-MSCs differentiation into mature chondrocytes. This work demonstrates that it is possible to promote chondrogenesis of hUCB-MSCs in combination with hACs, further supporting the concept of novel coculture strategies for tissue engineering.

  16. Human Umbilical Cord Blood-Derived Mesenchymal Stem Cells Contribute to Chondrogenesis in Coculture with Chondrocytes

    Directory of Open Access Journals (Sweden)

    Xingfu Li

    2016-01-01

    Full Text Available Human umbilical cord blood-derived mesenchymal stem cells (hUCB-MSCs have been shown as the most potential stem cell source for articular cartilage repair. In this study, we aimed to develop a method for long-term coculture of human articular chondrocytes (hACs and hUCB-MSCs at low density in vitro to determine if the low density of hACs could enhance the hUCB-MSC chondrogenic differentiation as well as to determine the optimal ratio of the two cell types. Also, we compared the difference between direct coculture and indirect coculture at low density. Monolayer cultures of hUCB-MSCs and hACs were investigated at different ratios, at direct cell-cell contact groups for 21 days. Compared to direct coculture, hUCB-MSCs and hACs indirect contact culture significantly increased type II collagen (COL2 and decreased type I collagen (COL1 protein expression levels. SRY-box 9 (SOX9 mRNA levels and protein expression were highest in indirect coculture. Overall, these results indicate that low density direct coculture induces fibrocartilage. However, indirect coculture in conditioned chondrocyte cell culture medium can increase expression of chondrogenic markers and induce hUCB-MSCs differentiation into mature chondrocytes. This work demonstrates that it is possible to promote chondrogenesis of hUCB-MSCs in combination with hACs, further supporting the concept of novel coculture strategies for tissue engineering.

  17. Small molecule-directed specification of sclerotome-like chondroprogenitors and induction of a somitic chondrogenesis program from embryonic stem cells.

    Science.gov (United States)

    Zhao, Jiangang; Li, Songhui; Trilok, Suprita; Tanaka, Makoto; Jokubaitis-Jameson, Vanta; Wang, Bei; Niwa, Hitoshi; Nakayama, Naoki

    2014-10-01

    Pluripotent embryonic stem cells (ESCs) generate rostral paraxial mesoderm-like progeny in 5-6 days of differentiation induced by Wnt3a and Noggin (Nog). We report that canonical Wnt signaling introduced either by forced expression of activated β-catenin, or the small-molecule inhibitor of Gsk3, CHIR99021, satisfied the need for Wnt3a signaling, and that the small-molecule inhibitor of BMP type I receptors, LDN193189, was able to replace Nog. Mesodermal progeny generated using such small molecules were chondrogenic in vitro, and expressed trunk paraxial mesoderm markers such as Tcf15 and Meox1, and somite markers such as Uncx, but failed to express sclerotome markers such as Pax1. Induction of the osteochondrogenically committed sclerotome from somite requires sonic hedgehog and Nog. Consistently, Pax1 and Bapx1 expression was induced when the isolated paraxial mesodermal progeny were treated with SAG1 (a hedgehog receptor agonist) and LDN193189, then Sox9 expression was induced, leading to cartilaginous nodules and particles in the presence of BMP, indicative of chondrogenesis via sclerotome specification. By contrast, treatment with TGFβ also supported chondrogenesis and stimulated Sox9 expression, but failed to induce the expression of Pax1 and Bapx1. On ectopic transplantation to immunocompromised mice, the cartilage particles developed under either condition became similarly mineralized and formed pieces of bone with marrow. Thus, the use of small molecules led to the effective generation from ESCs of paraxial mesodermal progeny, and to their further differentiation in vitro through sclerotome specification into growth plate-like chondrocytes, a mechanism resembling in vivo somitic chondrogenesis that is not recapitulated with TGFβ. © 2014. Published by The Company of Biologists Ltd.

  18. The Nuclear Factor of Activated T Cells (Nfat) Transcription Factor Nfatp (Nfatc2) Is a Repressor of Chondrogenesis

    Science.gov (United States)

    Ranger, Ann M.; Gerstenfeld, Louis C.; Wang, Jinxi; Kon, Tamiyo; Bae, Hyunsu; Gravallese, Ellen M.; Glimcher, Melvin J.; Glimcher, Laurie H.

    2000-01-01

    Nuclear factor of activated T cells (NFAT) transcription factors regulate gene expression in lymphocytes and control cardiac valve formation. Here, we report that NFATp regulates chondrogenesis in the adult animal. In mice lacking NFATp, resident cells in the extraarticular connective tissues spontaneously differentiate to cartilage. These cartilage cells progressively differentiate and the tissue undergoes endochondral ossification, recapitulating the development of endochondral bone. Proliferation of already existing articular cartilage cells also occurs in some older animals. At both sites, neoplastic changes in the cartilage cells occur. Consistent with these data, NFATp expression is regulated in mesenchymal stem cells induced to differentiate along a chondrogenic pathway. Lack of NFATp in articular cartilage cells results in increased expression of cartilage markers, whereas overexpression of NFATp in cartilage cell lines extinguishes the cartilage phenotype. Thus, NFATp is a repressor of cartilage cell growth and differentiation and also has the properties of a tumor suppressor. PMID:10620601

  19. Effect of parathyroid hormone-related protein in an in vitro hypertrophy model for mesenchymal stem cell chondrogenesis.

    Science.gov (United States)

    Mueller, Michael B; Fischer, Maria; Zellner, Johannes; Berner, Arne; Dienstknecht, Thomas; Kujat, Richard; Prantl, Lukas; Nerlich, Michael; Tuan, Rocky S; Angele, Peter

    2013-05-01

    Mesenchymal stem cells (MSCs) express markers of hypertrophic chondrocytes during chondrogenic differentiation. We tested the suitability of parathyroid hormone-related protein (PTHrP), a regulator of chondrocyte hypertrophy in embryonic cartilage development, for the suppression of hypertrophy in an in vitro hypertrophy model of chondrifying MSCs. Chondrogenesis was induced in human MSCs in pellet culture for two weeks and for an additional two weeks cultures were either maintained in standard chondrogenic medium or transferred to a hypertrophy-enhancing medium. PTHrP(1-40) was added to the medium throughout the culture period at concentrations from 1 to 1,000 pM. Pellets were harvested on days one, 14 and 28 for biochemical and histological analysis. Hypertrophic medium clearly enhanced the hypertrophic phenotype, with increased cell size, and strong alkaline phosphatase (ALP) and type X collagen staining. In chondrogenic medium, 1-100 pM PTHrP(1-40) did not inhibit chondrogenic differentiation, whereas 1,000 pM PTHrP(1-40) significantly reduced chondrogenesis. ALP activity was dose-dependently reduced by PTHrP(1-40) at 10-1,000 pM in chondrogenic conditions. Under hypertrophy-enhancing conditions, PTHrP(1-40) did not inhibit the induction of the hypertrophy. At the highest concentration (1,000 pM) in the hypertrophic group, aggregates were partially dedifferentiated and differentiated areas of these aggregates maintained their hypertrophic appearance. PTHrP(1-40) treatment dose-dependently reduced ALP expression in MSC pellets cultured under standard chondrogenic conditions and is thus beneficial for the maintenance of the chondrogenic phenotype in this medium condition. When cultured under hypertrophy-enhancing conditions, PTHrP(1-40) could not diminish the induced enhancement of hypertrophy in the MSC pellets.

  20. Role of PTHrP(1-34) Pulse Frequency Versus Pulse Duration to Enhance Mesenchymal Stromal Cell Chondrogenesis.

    Science.gov (United States)

    Fischer, Jennifer; Ortel, Marlen; Hagmann, Sebastien; Hoeflich, Andreas; Richter, Wiltrud

    2016-12-01

    Generation of phenotypically stable, articular chondrocytes from mesenchymal stromal cells (MSCs) is still an unaccomplished task, with formation of abundant, hyaline extracellular matrix, and avoidance of hypertrophy being prime challenges. We recently demonstrated that parathyroid hormone-related protein (PTHrP) is a promising factor to direct chondrogenesis of MSCs towards an articular phenotype, since intermittent PTHrP application stimulated cartilage matrix production and reduced undesired hypertrophy. We here investigated the role of frequency, pulse duration, total exposure time, and underlying mechanisms in order to unlock the full potential of PTHrP actions. Human MSC subjected to in vitro chondrogenesis for six weeks were exposed to 2.5 nM PTHrP(1-34) pulses from days 7 to 42. Application frequency was increased from three times weekly (3 × 6 h/week) to daily maintaining either the duration of individual pulses (6 h/day) or total exposure time (18 h/week; 2.6 h/day). Daily PTHrP treatment significantly increased extracellular matrix deposition regardless of pulse duration and suppressed alkaline-phosphatase activity by 87%. High total exposure time significantly reduced cell proliferation at day 14. Pulse duration was critically important to significantly reduce IHH expression, but irrelevant for PTHrP-induced suppression of the hypertrophic markers MEF2C and IBSP. COL10A1, RUNX2, and MMP13 expression remained unaltered. Decreased IGFBP-2, -3, and -6 expression suggested modulated IGF-I availability in PTHrP groups, while drop of SOX9 protein levels during the PTHrP-pulse may delay chondroblast formation and hypertrophy. Overall, the significantly optimized timing of PTHrP-pulses demonstrated a vast potential to enhance chondrogenesis of MSC and suppress hypertrophy possibly via superior balancing of IGF- and SOX9-related mechanisms. J. Cell. Physiol. 231: 2673-2681, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  1. Analysis of the effects of five factors relevant to in vitro chondrogenesis of human mesenchymal stem cells using factorial design and high throughput mRNA-profiling.

    Science.gov (United States)

    Jakobsen, Rune B; Østrup, Esben; Zhang, Xiaolan; Mikkelsen, Tarjei S; Brinchmann, Jan E

    2014-01-01

    The in vitro process of chondrogenic differentiation of mesenchymal stem cells for tissue engineering has been shown to require three-dimensional culture along with the addition of differentiation factors to the culture medium. In general, this leads to a phenotype lacking some of the cardinal features of native articular chondrocytes and their extracellular matrix. The factors used vary, but regularly include members of the transforming growth factor β superfamily and dexamethasone, sometimes in conjunction with fibroblast growth factor 2 and insulin-like growth factor 1, however the use of soluble factors to induce chondrogenesis has largely been studied on a single factor basis. In the present study we combined a factorial quality-by-design experiment with high-throughput mRNA profiling of a customized chondrogenesis related gene set as a tool to study in vitro chondrogenesis of human bone marrow derived mesenchymal stem cells in alginate. 48 different conditions of transforming growth factor β 1, 2 and 3, bone morphogenetic protein 2, 4 and 6, dexamethasone, insulin-like growth factor 1, fibroblast growth factor 2 and cell seeding density were included in the experiment. The analysis revealed that the best of the tested differentiation cocktails included transforming growth factor β 1 and dexamethasone. Dexamethasone acted in synergy with transforming growth factor β 1 by increasing many chondrogenic markers while directly downregulating expression of the pro-osteogenic gene osteocalcin. However, all factors beneficial to the expression of desirable hyaline cartilage markers also induced undesirable molecules, indicating that perfect chondrogenic differentiation is not achievable with the current differentiation protocols.

  2. Pharmacological modulation of human mesenchymal stem cell chondrogenesis by a chemically oversulfated polysaccharide of marine origin: potential application to cartilage regenerative medicine.

    Science.gov (United States)

    Merceron, Christophe; Portron, Sophie; Vignes-Colombeix, Caroline; Rederstorff, Emilie; Masson, Martial; Lesoeur, Julie; Sourice, Sophie; Sinquin, Corinne; Colliec-Jouault, Sylvia; Weiss, Pierre; Vinatier, Claire; Guicheux, Jérôme

    2012-03-01

    Mesenchymal stem cells (MSCs) are considered as an attractive source of cells for cartilage engineering due to their availability and capacity for expansion and multipotency. Differentiation of MSC into chondrocytes is crucial to successful cartilage regeneration and can be induced by various biological agents, including polysaccharides that participate in many biological processes through interactions with growth factors. Here, we hypothesize that growth factor-induced differentiation of MSC can be increased by chemically oversulfated marine polysaccharides. To test our hypothesis, human adipose tissue-derived MSCs (hATSCs) were cultured in pellets with transforming growth factor (TGF)-β1-supplemented chondrogenic medium containing either the polysaccharide GY785 DR or its oversulfated isoform GY785 DRS. Chondrogenesis was monitored by the measurement of pellet volume, quantification of DNA, collagens, glycosaminoglycans (GAGs), and immunohistological staining. Our data revealed an increase in pellet volume, total collagens, and GAG production with GY785 DRS and chondrogenic medium. The enhanced chondrogenic differentiation of hATSC was further demonstrated by the increased expression of several chondrogenic markers by real-time reverse transcription-polymerase chain reaction. In addition, surface plasmon resonance analyses revealed that TGF-β1 bound GY785 DRS with higher affinity compared to GY785 DR. In association with TGF-β1, GY785 DRS was found to upregulate the phosphorylation of extracellular signal-regulated kinase 1/2, indicating that oversulfated polysaccharide affects the mitogen activated protein kinase signaling activity. These results demonstrate the upregulation of TGF-β1-dependent stem cell chondrogenesis by a chemically oversulfated marine polysaccharide. This polysaccharide of marine origin is easily producible and therefore could be considered a promising additive to drive efficient and reliable MSC chondrogenesis for cartilage tissue

  3. Analysis of the Effects of Five Factors Relevant to In Vitro Chondrogenesis of Human Mesenchymal Stem Cells Using Factorial Design and High Throughput mRNA-Profiling

    Science.gov (United States)

    Jakobsen, Rune B.; Østrup, Esben; Zhang, Xiaolan; Mikkelsen, Tarjei S.; Brinchmann, Jan E.

    2014-01-01

    The in vitro process of chondrogenic differentiation of mesenchymal stem cells for tissue engineering has been shown to require three-dimensional culture along with the addition of differentiation factors to the culture medium. In general, this leads to a phenotype lacking some of the cardinal features of native articular chondrocytes and their extracellular matrix. The factors used vary, but regularly include members of the transforming growth factor β superfamily and dexamethasone, sometimes in conjunction with fibroblast growth factor 2 and insulin-like growth factor 1, however the use of soluble factors to induce chondrogenesis has largely been studied on a single factor basis. In the present study we combined a factorial quality-by-design experiment with high-throughput mRNA profiling of a customized chondrogenesis related gene set as a tool to study in vitro chondrogenesis of human bone marrow derived mesenchymal stem cells in alginate. 48 different conditions of transforming growth factor β 1, 2 and 3, bone morphogenetic protein 2, 4 and 6, dexamethasone, insulin-like growth factor 1, fibroblast growth factor 2 and cell seeding density were included in the experiment. The analysis revealed that the best of the tested differentiation cocktails included transforming growth factor β 1 and dexamethasone. Dexamethasone acted in synergy with transforming growth factor β 1 by increasing many chondrogenic markers while directly downregulating expression of the pro-osteogenic gene osteocalcin. However, all factors beneficial to the expression of desirable hyaline cartilage markers also induced undesirable molecules, indicating that perfect chondrogenic differentiation is not achievable with the current differentiation protocols. PMID:24816923

  4. Analysis of the effects of five factors relevant to in vitro chondrogenesis of human mesenchymal stem cells using factorial design and high throughput mRNA-profiling.

    Directory of Open Access Journals (Sweden)

    Rune B Jakobsen

    Full Text Available The in vitro process of chondrogenic differentiation of mesenchymal stem cells for tissue engineering has been shown to require three-dimensional culture along with the addition of differentiation factors to the culture medium. In general, this leads to a phenotype lacking some of the cardinal features of native articular chondrocytes and their extracellular matrix. The factors used vary, but regularly include members of the transforming growth factor β superfamily and dexamethasone, sometimes in conjunction with fibroblast growth factor 2 and insulin-like growth factor 1, however the use of soluble factors to induce chondrogenesis has largely been studied on a single factor basis. In the present study we combined a factorial quality-by-design experiment with high-throughput mRNA profiling of a customized chondrogenesis related gene set as a tool to study in vitro chondrogenesis of human bone marrow derived mesenchymal stem cells in alginate. 48 different conditions of transforming growth factor β 1, 2 and 3, bone morphogenetic protein 2, 4 and 6, dexamethasone, insulin-like growth factor 1, fibroblast growth factor 2 and cell seeding density were included in the experiment. The analysis revealed that the best of the tested differentiation cocktails included transforming growth factor β 1 and dexamethasone. Dexamethasone acted in synergy with transforming growth factor β 1 by increasing many chondrogenic markers while directly downregulating expression of the pro-osteogenic gene osteocalcin. However, all factors beneficial to the expression of desirable hyaline cartilage markers also induced undesirable molecules, indicating that perfect chondrogenic differentiation is not achievable with the current differentiation protocols.

  5. Comparison of Simulated Microgravity and Hydrostatic Pressure for Chondrogenesis of hASC.

    Science.gov (United States)

    Mellor, Liliana F; Steward, Andrew J; Nordberg, Rachel C; Taylor, Michael A; Loboa, Elizabeth G

    2017-04-01

    Cartilage tissue engineering is a growing field due to the lack of regenerative capacity of native tissue. The use of bioreactors for cartilage tissue engineering is common, but the results are controversial. Some studies suggest that microgravity bioreactors are ideal for chondrogenesis, while others show that mimicking hydrostatic pressure is crucial for cartilage formation. A parallel study comparing the effects of loading and unloading on chondrogenesis has not been performed. The goal of this study was to evaluate chondrogenesis of human adipose-derived stem cells (hASC) under two different mechanical stimuli relative to static culture: microgravity and cyclic hydrostatic pressure (CHP). Pellets of hASC were cultured for 14 d under simulated microgravity using a rotating wall vessel bioreactor or under CHP (7.5 MPa, 1 Hz, 4 h · d-1) using a hydrostatic pressure vessel. We found that CHP increased mRNA expression of Aggrecan, Sox9, and Collagen II, caused a threefold increase in sulfated glycosaminoglycan production, and resulted in stronger vimentin staining intensity and organization relative to microgravity. In addition, Wnt-signaling patterns were altered in a manner that suggests that simulated microgravity decreases chondrogenic differentiation when compared to CHP. Our goal was to compare chondrogenic differentiation of hASC using a microgravity bioreactor and a hydrostatic pressure vessel, two commonly used bioreactors in cartilage tissue engineering. Our results indicate that CHP promotes hASC chondrogenesis and that microgravity may inhibit hASC chondrogenesis. Our findings further suggest that cartilage formation and regeneration might be compromised in space due to the lack of mechanical loading.Mellor LF, Steward AJ, Nordberg RC, Taylor MA, Loboa EG. Comparison of simulated microgravity and hydrostatic pressure for chondrogenesis of hASC. Aerosp Med Hum Perform. 2017; 88(4):377-384.

  6. Blocking p38 signalling inhibits chondrogenesis in vitro but not ankylosis in a model of ankylosing spondylitis in vivo.

    Science.gov (United States)

    Braem, Kirsten; Luyten, Frank P; Lories, Rik J U

    2012-05-01

    To investigate p38 mitogen activated protein kinase (MAPK) signalling in an in vitro model of bone morphogenetic protein (BMP) and transforming growth factor β (TGFβ)-induced chondrogenesis and in vivo, with specific attention to its potential role in ankylosing enthesitis. Human periosteum-derived cells (hPDCs) were cultured in pellets and stimulated with BMP2 or TGFβ1 in the presence or absence of a p38 inhibitor SB203580 or proinflammatory cytokines. Chondrogenic differentiation was evaluated using quantitative PCR. Male DBA/1 mice from different litters were caged together at the age of 8 weeks and treated with SB203580 in both a preventive and therapeutic strategy. The mice were evaluated for prospective signs of arthritis and the toe joints were analysed histologically to assess disease severity. p38 inhibition by SB203580 and proinflammatory cytokines downregulated chondrogenic markers in pellet cultures stimulated by BMP2 or TGFβ1. In contrast, the in vivo experiments resulted in an increased clinical incidence of arthritis and pathology severity score, reflecting progression towards ankylosis in mice given SB203580. Inhibition of p38 inhibited chondrogenic differentiation of progenitor cells, showing that not only the SMAD signalling pathways and also alternative activation of MAPKs including p38 contribute to chondrogenesis. Such an inhibitory effect is not found in an in vivo model of joint ankylosis and spondyloarthritis. Increased incidence and severity of disease in preventive experiments and shifts in disease stages in a therapeutic experimental set-up suggest that specific inhibition of p38 may have deleterious rather than beneficial effects.

  7. Insulin-Like Growth Factor-Independent Effects of Growth Hormone on Growth Plate Chondrogenesis and Longitudinal Bone Growth.

    Science.gov (United States)

    Wu, Shufang; Yang, Wei; De Luca, Francesco

    2015-07-01

    GH stimulates growth plate chondrogenesis and longitudinal bone growth directly at the growth plate. However, it is not clear yet whether these effects are entirely mediated by the local expression and action of IGF-1 and IGF-2. To determine whether GH has any IGF-independent growth-promoting effects, we generated (TamCart)Igf1r(flox/flox) mice. The systemic injection of tamoxifen in these mice postnatally resulted in the excision of the IGF-1 receptor (Igf1r) gene exclusively in the growth plate. (TamCart)Igf1r(flox/flox) tamoxifen-treated mice [knockout (KO) mice] and their Igf1r(flox/flox) control littermates (C mice) were injected for 4 weeks with GH. At the end of the 4-week period, the tibial growth and growth plate height of GH-treated KO mice were greater than those of untreated C or untreated KO mice. The systemic injection of GH increased the phosphorylation of Janus kinase 2 and signal transducer and activator of transcription 5B in the tibial growth plate of the C and KO mice. In addition, GH increased the mRNA expression of bone morphogenetic protein-2 and the mRNA expression and protein phosphorylation of nuclear factor-κB p65 in both C and KO mice. In cultured chondrocytes transfected with Igf1r small interfering RNA, the addition of GH in the culture medium significantly induced thymidine incorporation and collagen X mRNA expression. In conclusion, our findings demonstrate that GH can promote growth plate chondrogenesis and longitudinal bone growth directly at the growth plate, even when the local effects of IGF-1 and IGF-2 are prevented. Further studies are warranted to elucidate the intracellular molecular mechanisms mediating the IGF-independent, growth-promoting GH effects.

  8. Sodium Tungstate for Promoting Mesenchymal Stem Cell Chondrogenesis.

    Science.gov (United States)

    Khader, Ateka; Sherman, Lauren S; Rameshwar, Pranela; Arinzeh, Treena L

    2016-12-15

    Articular cartilage has a limited ability to heal. Mesenchymal stem cells (MSCs) derived from the bone marrow have shown promise as a cell type for cartilage regeneration strategies. In this study, sodium tungstate (Na 2 WO 4 ), which is an insulin mimetic, was evaluated for the first time as an inductive factor to enhance human MSC chondrogenesis. MSCs were seeded onto three-dimensional electrospun scaffolds in growth medium (GM), complete chondrogenic induction medium (CCM) containing insulin, and CCM without insulin. Na 2 WO 4 was added to the media leading to final concentrations of 0, 0.01, 0.1, and 1 mM. Chondrogenic differentiation was assessed by biochemical analyses, immunostaining, and gene expression. Cytotoxicity using human peripheral blood mononuclear cells (PBMCS) was also investigated. The chondrogenic differentiation of MSCs was enhanced in the presence of low concentrations of Na 2 WO 4 compared to control, without Na 2 WO 4 . In the induction medium containing insulin, cells in 0.01 mM Na 2 WO 4 produced significantly higher sulfated glycosaminoglycans, collagen type II, and chondrogenic gene expression than all other groups at day 28. Cells in 0.1 mM Na 2 WO 4 had significantly higher collagen II production and significantly higher sox-9 and aggrecan gene expression compared to control at day 28. Cells in GM and induction medium without insulin containing low concentrations of Na 2 WO 4 also expressed chondrogenic markers. Na 2 WO 4 did not stimulate PBMC proliferation or apoptosis. The results demonstrate that Na 2 WO 4 enhances chondrogenic differentiation of MSCs, does not have a toxic effect, and may be useful for MSC-based approaches for cartilage repair.

  9. Interaction of TGFβ and BMP signaling pathways during chondrogenesis.

    Directory of Open Access Journals (Sweden)

    Bettina Keller

    2011-01-01

    Full Text Available TGFβ and BMP signaling pathways exhibit antagonistic activities during the development of many tissues. Although the crosstalk between BMP and TGFβ signaling pathways is well established in bone development, the relationship between these two pathways is less well defined during cartilage development and postnatal homeostasis. We generated hypomorphic mouse models of cartilage-specific loss of BMP and TGFβ signaling to assess the interaction of these pathways in postnatal growth plate homeostasis. We further used the chondrogenic ATDC5 cell line to test effects of BMP and TGFβ signaling on each other's downstream targets. We found that conditional deletion of Smad1 in chondrocytes resulted in a shortening of the growth plate. The addition of Smad5 haploinsufficiency led to a more severe phenotype with shorter prehypertrophic and hypertrophic zones and decreased chondrocyte proliferation. The opposite growth plate phenotype was observed in a transgenic mouse model of decreased chondrocytic TGFβ signaling that was generated by expressing a dominant negative form of the TGFβ receptor I (ΔTβRI in cartilage. Histological analysis demonstrated elongated growth plates with enhanced Ihh expression, as well as an increased proliferation rate with altered production of extracellular matrix components. In contrast, in chondrogenic ATDC5 cells, TGFβ was able to enhance BMP signaling, while BMP2 significantly reduces levels of TGF signaling. In summary, our data demonstrate that during endochondral ossification, BMP and TGFβ signaling can have antagonistic effects on chondrocyte proliferation and differentiation in vivo. We also found evidence of direct interaction between the two signaling pathways in a cell model of chondrogenesis in vitro.

  10. Mechanoactive scaffold induces tendon remodeling and expression of fibrocartilage markers.

    Science.gov (United States)

    Spalazzi, Jeffrey P; Vyner, Moira C; Jacobs, Matthew T; Moffat, Kristen L; Lu, Helen H

    2008-08-01

    Biological fixation of soft tissue-based grafts for anterior cruciate ligament (ACL) reconstruction poses a major clinical challenge. The ACL integrates with subchondral bone through a fibrocartilage enthesis, which serves to minimize stress concentrations and enables load transfer between two distinct tissue types. Functional integration thus requires the reestablishment of this fibrocartilage interface on reconstructed ACL grafts. We designed and characterized a novel mechanoactive scaffold based on a composite of poly-alpha-hydroxyester nanofibers and sintered microspheres; we then used the scaffold to test the hypothesis that scaffold-induced compression of tendon grafts would result in matrix remodeling and the expression of fibrocartilage interface-related markers. Histology coupled with confocal microscopy and biochemical assays were used to evaluate the effects of scaffold-induced compression on tendon matrix collagen distribution, cellularity, proteoglycan content, and gene expression over a 2-week period. Scaffold contraction resulted in over 15% compression of the patellar tendon graft and upregulated the expression of fibrocartilage-related markers such as Type II collagen, aggrecan, and transforming growth factor-beta3 (TGF-beta3). Additionally, proteoglycan content was higher in the compressed tendon group after 1 day. The data suggest the potential of a mechanoactive scaffold to promote the formation of an anatomic fibrocartilage enthesis on tendon-based ACL reconstruction grafts.

  11. Delineation of in vitro chondrogenesis of human synovial stem cells following preconditioning using decellularized matrix

    Science.gov (United States)

    Zhang, Ying; Li, Jingting; Davis, Mary E.; Pei, Ming

    2015-01-01

    As a tissue-specific stem cell for chondrogenesis, synovium-derived stem cells (SDSCs) are a promising cell source for cartilage repair. However, a small biopsy can only provide a limited number of cells. Cell senescence from both in vitro expansion and donor age presents a big challenge for stem cell based cartilage regeneration. Here we found that expansion on decellularized extracellular matrix (dECM) full of three-dimensional nanostructured fibers provided SDSCs with unique surface profiles, low elasticity but large volume as well as fibroblast-like shape. dECM expanded SDSCs yielded larger pellets with intensive staining of type II collagen and sulfated glycosaminoglycans compared to those grown on plastic flasks while SDSCs grown in ECM yielded 28-day pellets with minimal matrix as evidenced by pellet size and chondrogenic marker staining, which was confirmed by both biochemical data and real-time PCR data. Our results also found lower levels of inflammatory genes in dECM expanded SDSCs that might be responsible for enhanced chondrogenic differentiation. Despite an increase in type X collagen in chondrogenically induced cells, dECM expanded cells had significantly lower potential for endochondral bone formation. Wnt and MAPK signals were actively involved in both expansion and chondrogenic induction of dECM expanded cells. Since young and healthy people can be potential donors for this matrix expansion system and decellularization can minimize immune concerns, human SDSCs expanded on this future commercially available dECM could be a potential cell source for autologous cartilage repair. PMID:25861949

  12. β1 integrins regulate chondrogenesis and rock signaling in adipose stem cells

    NARCIS (Netherlands)

    Lu, Z.F.; Doulabi, B.Z.; Huang, C.L.; Bank, R.A.; Helder, M.N.

    2008-01-01

    β1 integrins play a controversial role during chondrogenesis. Since the maturation of chondrocytes relies on a signaling switch from cell-cell to cell-matrix interactions, we hypothesized that β1 integrins play a different role at the earlier (mainly cell-cell interaction) from the later stage

  13. Ihh and Runx2/Runx3 signaling interact to coordinate early chondrogenesis: a mouse model.

    Directory of Open Access Journals (Sweden)

    Eun-Jung Kim

    Full Text Available Endochondral bone formation begins with the development of a cartilage intermediate that is subsequently replaced by calcified bone. The mechanisms occurring during early chondrogenesis that control both mesenchymal cell differentiation into chondrocytes and cell proliferation are not clearly understood in vertebrates. Indian hedgehog (Ihh, one of the hedgehog signaling molecules, is known to control both the hypertrophy of chondrocytes and bone replacement; these processes are particularly important in postnatal endochondral bone formation rather than in early chondrogenesis. In this study, we utilized the maternal transfer of 5E1 to E12.5 in mouse embryos, a process that leads to an attenuation of Ihh activity. As a result, mouse limb bud chondrogenesis was inhibited, and an exogenous recombinant IHH protein enhanced the proliferation and differentiation of mesenchymal cells. Analysis of the genetic relationships in the limb buds suggested a more extensive role for Ihh and Runx genes in early chondrogenesis. The transfer of 5E1 decreased the expression of Runx2 and Runx3, whereas an exogenous recombinant IHH protein increased Runx2 and Runx3 expression. Moreover, a transcription factor Gli1 in hedgehog pathway enhances the direct induction of both Runx2 and Runx3 transcription. These findings suggested that Ihh signaling plays an important role in chondrocyte proliferation and differentiation via interactions with Runx2 and Runx3.

  14. Ihh and Runx2/Runx3 signaling interact to coordinate early chondrogenesis: a mouse model.

    Science.gov (United States)

    Kim, Eun-Jung; Cho, Sung-Won; Shin, Jeong-Oh; Lee, Min-Jung; Kim, Kye-Seong; Jung, Han-Sung

    2013-01-01

    Endochondral bone formation begins with the development of a cartilage intermediate that is subsequently replaced by calcified bone. The mechanisms occurring during early chondrogenesis that control both mesenchymal cell differentiation into chondrocytes and cell proliferation are not clearly understood in vertebrates. Indian hedgehog (Ihh), one of the hedgehog signaling molecules, is known to control both the hypertrophy of chondrocytes and bone replacement; these processes are particularly important in postnatal endochondral bone formation rather than in early chondrogenesis. In this study, we utilized the maternal transfer of 5E1 to E12.5 in mouse embryos, a process that leads to an attenuation of Ihh activity. As a result, mouse limb bud chondrogenesis was inhibited, and an exogenous recombinant IHH protein enhanced the proliferation and differentiation of mesenchymal cells. Analysis of the genetic relationships in the limb buds suggested a more extensive role for Ihh and Runx genes in early chondrogenesis. The transfer of 5E1 decreased the expression of Runx2 and Runx3, whereas an exogenous recombinant IHH protein increased Runx2 and Runx3 expression. Moreover, a transcription factor Gli1 in hedgehog pathway enhances the direct induction of both Runx2 and Runx3 transcription. These findings suggested that Ihh signaling plays an important role in chondrocyte proliferation and differentiation via interactions with Runx2 and Runx3.

  15. Quantitative transcriptional profiling of ATDC5 mouse progenitor cells during chondrogenesis

    DEFF Research Database (Denmark)

    Chen, Li; Fink, Trine; Zhang, Xiao-Yan

    2005-01-01

    During the differentiation of a mouse chondroprogenitor cell line, ATDC5, an analysis of the transcription cartilage-related genes was carried out using real-time RT-PCR in a semiquantitative fashion. A total number of 104 genes both previously linked to chondrogenesis and hitherto not associated...

  16. A 3D Porous Gelatin-Alginate-Based-IPN Acts as an Efficient Promoter of Chondrogenesis from Human Adipose-Derived Stem Cells

    Directory of Open Access Journals (Sweden)

    Sorina Dinescu

    2015-01-01

    Full Text Available Cartilage has limited regeneration potential. Thus, there is an imperative need to develop new strategies for cartilage tissue engineering (CTE amenable for clinical use. Recent CTE approaches rely on optimal cell-scaffold interactions, which require a great deal of optimization. In this study we attempt to build a novel gelatin- (G- alginate- (A- polyacrylamide (PAA 3D interpenetrating network (IPN with superior performance in promoting chondrogenesis from human adipose-derived stem cells (hADSCs. We show that our G-A-PAA scaffold is capable of supporting hADSCs proliferation and survival, with no apparent cytotoxic effect. Moreover, we find that after exposure to prochondrogenic conditions a key transcription factor known to induce chondrogenesis, namely, Sox9, is highly expressed in our hADSCs/G-A-PAA bioconstruct, along with cartilage specific markers such as collagen type II, CEP68, and COMP extracellular matrix (ECM components. These data suggest that our G-A-PAA structural properties and formulation might enable hADSCs conversion towards functional chondrocytes. We conclude that our novel G-A-PAA biomatrix is a good candidate for prospective in vivo CTE applications.

  17. Serum TGF-beta2 and TGF-beta3 are increased and positively correlated to pain, functionality, and radiographic staging in osteoarthritis.

    Science.gov (United States)

    Kapetanakis, Stilianos; Drygiannakis, Ioannis; Kazakos, Kostantinos; Papanas, Nikolaos; Kolios, George; Kouroumalis, Elias; Verettas, Dionysios-Alexandros

    2010-08-11

    The goal of this study was to verify or reject the hypothesis that systematic differences exist in various profibrotic or antifibrotic factors between osteoarthritic patients and controls, as well as between different stages of osteoarthritis. The study group comprised 63 patients with knee osteoarthritis and 18 controls. Transforming growth factor-beta (TGF-beta)1, -2, -3; tissue inhibitor of metalloproteinase (TIMP)-1 protein levels; and gelatinolytic activity of matrix metalloproteinase (MMP)-1, -2, -3, -9 activities were measured by enzyme-linked immunosorbent assay and gelatin zymography, respectively. Visual analog scale scores, Western Ontario and McMaster Universities Arthritis Index (WOMAC) scores, Lequesne clinical osteoarthritis scales, and Kellgren-Lawrence radiographic grading were recorded for each patient.Transforming growth factor-beta2 and -3 (in contrast to TGF-beta1 and TIMP-1) serum protein levels were significantly higher in osteoarthritic patients compared to controls (210%+/-14% [P<.001] and 232%+/-7% [P<10(-7)], respectively). Additionally, TGF-beta2 and -3 were strongly positively correlated to Kellgren-Lawrence radiographic grading of the disease (P<10(-5) and P<10(-7), respectively). Moreover, TGF-beta2 correlated positively with the WOMAC scale (P=.007). However, TIMP-1 decreased as osteoarthritis progressed clinically, but remained irrelevant to radiographic staging. Furthermore, activities of MMP-2 and -9, but not MMP-1+/-3, were lower in patients with osteoarthritis. Copyright 2010, SLACK Incorporated.

  18. Steric Interference of Adhesion Supports In-Vitro Chondrogenesis of Mesenchymal Stem Cells on Hydrogels for Cartilage Repair

    OpenAIRE

    Goldshmid, Revital; Cohen, Shlomit; Shachaf, Yonatan; Kupershmit, Ilana; Sarig-Nadir, Offra; Seliktar, Dror; Wechsler, Roni

    2015-01-01

    Recent studies suggest the presence of cell adhesion motifs found in structural proteins can inhibit chondrogenesis. In this context, the current study aims to determine if a polyethylene glycol (PEG)-modified fibrinogen matrix could support better chondrogenesis of human bone marrow mesenchymal stem cells (BM-MSC) based on steric interference of adhesion, when compared to a natural fibrin matrix. Hydrogels used as substrates for two-dimensional (2D) BM-MSC cultures under chondrogenic conditi...

  19. Chondrogenesis of human adipose derived stem cells for future microtia repair using co-culture technique.

    Science.gov (United States)

    Goh, Bee See; Che Omar, Siti Nurhadis; Ubaidah, Muhammad Azhan; Saim, Lokman; Sulaiman, Shamsul; Chua, Kien Hui

    2017-04-01

    In conclusion, these result showed HADSCs could differentiate into chondrocytes-like cells, dependent on signaling induced by TGF-β3 and chondrocytes. This is a promising result and showed that HADSCs is a potential source for future microtia repair. The technique of co-culture is a positive way forward to assist the microtia tissue. Reconstructive surgery for the repair of microtia still remains the greatest challenge among the surgeons. Its repair is associated with donor-site morbidity and the degree of infection is inevitable when using alloplastic prosthesis with uncertain long-term durability. Thus, human adipose derived stem cells (HADSCs) can be an alternative cell source for cartilage regeneration. This study aims to evaluate the chondrogenic potential of HADSCs cultured with transforming growth factor-beta (TGF-β) and interaction of auricular chondrocytes with HADSCs for new cartilage generation. Multi-lineages differentiation features of HADSCs were monitored by Alcian Blue, Alizarin Red, and Oil Red O staining for chondrogenic, adipogenic, and osteogenic differentiation capacity, respectively. Further, HADSCs alone were culture in medium added with TGF-β3; and human auricular chondrocytes were interacted indirectly in the culture with and without TGF-βs for up to 21 days, respectively. Cell morphology and chondrogenesis were monitored by inverted microscope. For cell viability, Alamar Blue assay was used to measure the cell viability and the changes in gene expression of auricular chondrocyte markers were determined by real-time polymerase chain reaction analysis. For the induction of chondrogenic differentiation, HADSCs showed a feature of aggregation and formed a dense matrix of proteoglycans. Staining results from Alizirin Red and Oil Red O indicated the HADSCs also successfully differentiated into adipogenic and osteogenic lineages after 21 days. According to a previous study, HADSCs were strongly positive for the mesenchymal markers CD90, CD73

  20. Gdf11 is a negative regulator of chondrogenesis and myogenesis in the developing chick limb.

    Science.gov (United States)

    Gamer, L W; Cox, K A; Small, C; Rosen, V

    2001-01-15

    GDF11, a new member of the TGF-beta gene superfamily, regulates anterior/posterior patterning in the axial skeleton during mouse embryogenesis. Gdf11 null mice display skeletal abnormalities that appear to represent anterior homeotic transformations of vertebrae consistent with high levels of Gdf11 expression in the primitive streak, presomitic mesoderm, and tail bud. However, despite strong Gdf11 expression in the limb throughout development, this structure does not appear to be affected in the knockout mice. In order to understand this dichotomy of Gdf11 expression versus Gdf11 function, we identified the chicken Gdf11 gene and studied its role during limb formation. In the early limb bud, Gdf11 transcripts are detected in the subectodermal mesoderm at the distal tip, in a region overlapping the progress zone. At these stages, Gdf11 is excluded from the central core mesenchyme where precartilaginous condensations will form. Later in development, Gdf11 continues to be expressed in the distal most mesenchyme and can also be detected more proximally, in between the forming skeletal elements. When beads incubated in GDF11 protein were implanted into the early wing bud, GDF11 caused severe truncations of the limb that affected both the cartilage elements and the muscle. Limb shortening appeared to be the result of an inhibition of chondrogenesis and myogenesis and using an in vitro micromass assay, we confirmed the negative effects of GDF11 on both myogenic and chondrogenic cell differentiation. Analysis of molecular markers of skeletal patterning revealed that GDF11 induced ectopic expression of Hoxd-11 and Hoxd-13, but not of Hoxa-11, Hoxa-13, or the Msx genes. These data suggest that GDF11 may be involved in controlling the late distal expression of the Hoxd genes during limb development and that misregulation of these Hox genes by excess GDF11 may cause some of the observed alterations in skeletal element shape. In addition, GDF11 induced the expression of its own

  1. Metabolomic Analysis of Differential Changes in Metabolites during ATP Oscillations in Chondrogenesis

    Directory of Open Access Journals (Sweden)

    Hyuck Joon Kwon

    2013-01-01

    Full Text Available Prechondrogenic condensation is a critical step for skeletal pattern formation. Recent studies reported that ATP oscillations play an essential role in prechondrogenic condensation. However, the molecular mechanism to underlie ATP oscillations remains poorly understood. In the present study, it was investigated how changes in metabolites are implicated in ATP oscillations during chondrogenesis by using capillary electrophoresis time-of-flight mass spectrometry (CE-TOF-MS. CE-TOF-MS detected 93 cationic and 109 anionic compounds derived from known metabolic pathways. 15 cationic and 18 anionic compounds revealed significant change between peak and trough of ATP oscillations. These results implicate that glycolysis, mitochondrial respiration and uronic acid pathway oscillate in phase with ATP oscillations, while PPRP and nucleotides synthesis pathways oscillate in antiphase with ATP oscillations. This suggests that the ATP-producing glycolysis and mitochondrial respiration oscillate in antiphase with the ATP-consuming PPRP/nucleotide synthesis pathway during chondrogenesis.

  2. Sonic hedgehog promotes somitic chondrogenesis by altering the cellular response to BMP signaling

    OpenAIRE

    Murtaugh, L. Charles; Chyung, Jay H.; Lassar, Andrew B.

    1999-01-01

    Previous work has indicated that signals from the floor plate and notochord promote chondrogenesis of the somitic mesoderm. These tissues, acting through the secreted signaling molecule Sonic hedgehog (Shh), appear to be critical for the formation of the sclerotome. Later steps in the differentiation of sclerotome into cartilage may be independent of the influence of these axial tissues. Although the signals involved in these later steps have not yet been pinpointed, there is substantial evid...

  3. Cartilage oligomeric matrix protein enhances matrix assembly during chondrogenesis of human mesenchymal stem cells.

    Science.gov (United States)

    Haleem-Smith, Hana; Calderon, Raul; Song, Yingjie; Tuan, Rocky S; Chen, Faye H

    2012-04-01

    Cartilage oligomeric matrix protein/thrombospondin-5 (COMP/TSP5) is an abundant cartilage extracellular matrix (ECM) protein that interacts with major cartilage ECM components, including aggrecan and collagens. To test our hypothesis that COMP/TSP5 functions in the assembly of the ECM during cartilage morphogenesis, we have employed mesenchymal stem cell (MSC) chondrogenesis in vitro as a model to examine the effects of COMP over-expression on neo-cartilage formation. Human bone marrow-derived MSCs were transfected with either full-length COMP cDNA or control plasmid, followed by chondrogenic induction in three-dimensional pellet or alginate hydrogel culture. MSC chondrogenesis and ECM production was estimated based on quantitation of sulfated glycosaminoglycan (sGAG) accumulation, immunohistochemistry of the presence and distribution of cartilage ECM proteins, and real-time RT-PCR analyis of mRNA expression of cartilage markers. Our results showed that COMP over-expression resulted in increased total sGAG content during the early phase of MSC chondrogenesis, and increased immuno-detectable levels of aggrecan and collagen type II in the ECM of COMP-transfected pellet and alginate cultures, indicating more abundant cartilaginous matrix. COMP transfection did not significantly increase the transcript levels of the early chondrogenic marker, Sox9, or aggrecan, suggesting that enhancement of MSC cartilage ECM was effected at post-transcriptional levels. These findings strongly suggest that COMP functions in mesenchymal chondrogenesis by enhancing cartilage ECM organization and assembly. The action of COMP is most likely mediated not via direct changes in cartilage matrix gene expression but via interactions of COMP with other cartilage ECM proteins, such as aggrecan and collagens, that result in enhanced assembly and retention.

  4. Creation of an in vitro microenvironment to enhance human fetal synovium-derived stem cell chondrogenesis.

    Science.gov (United States)

    Li, Jingting; He, Fan; Pei, Ming

    2011-09-01

    Our aim was to assess the feasibility of the sequential application of extracellular matrix (ECM) and low oxygen to enhance chondrogenesis in human fetal synovium-derived stem cells (hfSDSCs). Human fetal synovial fibroblasts (hfSFs) were characterized and found to include hfSDSCs, as evidenced by their multi-differentiation capacity and the surface phenotype markers typical of mesenchymal stem cells. Passage-7 hfSFs were plated on either conventional plastic flasks (P) or ECM deposited by hfSFs (E) for one passage. Passage-8 hfSFs were then reseeded for an additional passage on either P or E. The pellets from expanded hfSFs were incubated in a serum-free chondrogenic medium supplemented with 10 ng/ml transforming growth factor-β3 under either normoxia (21% O(2); 21) or hypoxia (5% O(2); 5) for 14 days. Pellets were collected for evaluation of the treatments (EE21, EE5, EP21, EP5, PE21, PE5, PP21, and PP5) on expanded hfSF chondrogenesis by using histology, immunostaining, biochemistry, and real-time polymerase chain reaction. Our data suggest that, compared with seeding on conventional plastic flasks, hfSFs expanded on ECM exhibit a lower expression of senescence-associated β-galactosidase and an enhanced level of stage-specific embryonic antigen-4. ECM-expanded hfSFs also show increased cell numbers and an enhanced chondrogenic potential. Low oxygen (5% O(2)) during pellet culture enhances hfSF chondrogenesis. Thus, we demonstrate, for the first time, the presence of stem cells in hfSFs, and that modulation of the in vitro microenvironment can enhance hfSDSC chondrogenesis. hfSDSCs might represent a promising cell source for cartilage tissue engineering and regeneration.

  5. MED and PSACH COMP mutations affect chondrogenesis in chicken limb bud micromass cultures.

    Science.gov (United States)

    Roman-Blas, J; Dion, A S; Seghatoleslami, M R; Giunta, K; Oca, P; Jimenez, S A; Williams, C J

    2010-09-01

    Mutations in cartilage oligomeric matrix protein (COMP) cause pseudoachondroplasia (PSACH) and multiple epiphyseal dysplasia (MED). We studied the effects of over-expression of wild type and mutant COMP on early stages of chondrogenesis in chicken limb bud micromass cultures. Cells were transduced with RCAS virus harboring wild type or mutant (C328R, PSACH; T585R, MED) COMP cDNAs and cultured for 3, 4, and 5 days. The effect of COMP constructs on chondrogenesis was assessed by analyzing mRNA and protein expression of several COMP binding partners. Cell viability was assayed, and evaluation of apoptosis was performed by monitoring caspase 3 processing. Over-expression of COMP, and especially expression of COMP mutants, had a profound affect on the expression of syndecan 3 and tenascin C, early markers of chondrogenesis. Over-expression of COMP did not affect levels of type II collagen or matrilin-3; however, there were increases in type IX collagen expression and sulfated proteoglycan synthesis, particularly at day 5 of harvest. In contrast to cells over-expressing COMP, cells with mutant COMP showed reduction in type IX collagen expression and increased matrilin 3 expression. Finally, reduction in cell viability, and increased activity of caspase 3, at days 4 and 5, were observed in cultures expressing either wild type or mutant COMP. MED, and PSACH mutations, despite displaying phenotypic differences, demonstrated only subtle differences in their cellular viability and mRNA and protein expression of components of the extracellular matrix, including those that interact with COMP. These results suggest that COMP mutations, by disrupting normal interactions between COMP and its binding partners, significantly affect chondrogenesis. (c) 2010 Wiley-Liss, Inc.

  6. Leptin differentially regulates chondrogenesis in mouse vertebral and tibial growth plates.

    Science.gov (United States)

    Yu, Bo; Jiang, Kaibiao; Chen, Bin; Wang, Hantao; Li, Xinfeng; Liu, Zude

    2017-05-31

    Leptin plays an important role in mediating chondrogenesis of limb growth plate. Previous studies suggest that bone structures and development of spine and limb are different. The expression of Ob-Rb, the gene that encodes leptin receptors, is vertebral and appendicular region-specific, suggesting the regulation of leptin on VGP and TGP chondrogenesis may be very different. The aim of the present study was to investigate the differential regulation of leptin on the chondrogenesis of vertebral growth plate (VGP) and tibial growth plate (TGP). We compared the VGP and TGP from wild type (C57BL/6) and leptin-deficient (ob/ob) mice. We then generated primary cultures of TGP and VGP chondrocytes. By treating the primary cells with different concentrations of leptin in vitro, we analyzed proliferation and apoptosis of the primary chondrocytes from TGP and VGP. We further measured expression of chondrogenic-related genes in these cells that had been incubated with different doses of leptin. Leptin-deficient mice of 8-week-old had shorter tibial and longer vertebral lengths than the wide type mice. Disturbed columnar structure was observed for TGP but not for VGP. In primary chondrocyte cultures, leptin inhibited VGP chondrocyte proliferation but promoted their apoptosis. Collagen IIA and aggrecan mRNA, and the protein levels of proliferation- and chondrogenesis-related markers, including PCNA, Sox9, and Smad4, were downregulated by leptin in a dose-dependent manner. In contrast, leptin stimulated the proliferation and chondrogenic differentiation of TGP chondrocytes at physiological levels (i.e., 10 and 50 ng/mL) but not at high levels (i.e., 100 and 1000 ng/mL). Leptin exerts a stimulatory effect on the proliferation and chondrogenic differentiation of the long bone growth plate but an inhibitory effect on the spine growth plate. The ongoing study will shed light on the regulatory mechanisms of leptin in bone development and metabolism.

  7. CARTILAGE OLIGOMERIC MATRIX PROTEIN ENHANCES MATRIX ASSEMBLY DURING CHONDROGENESIS OF HUMAN MESENCHYMAL STEM CELLS

    Science.gov (United States)

    Haleem-Smith, Hana; Calderon, Raul; Song, Yingjie; Tuan, Rocky S.; Chen, Faye H.

    2011-01-01

    Cartilage oligomeric matrix protein/thrombospondin-5 (COMP/TSP5) is an abundant cartilage extracellular matrix (ECM) protein that interacts with major cartilage ECM components, including aggrecan and collagens. To test our hypothesis that COMP/TSP5 functions in the assembly of the ECM during cartilage morphogenesis, we have employed mesenchymal stem cell (MSC) chondrogenesis in vitro as a model to examine the effects of COMP over-expression on neo-cartilage formation. Human bone marrow-derived MSCs were transfected with either full-length COMP cDNA or control plasmid, followed by chondrogenic induction in three-dimensional pellet or alginate-hydrogel culture. MSC chondrogenesis and ECM production was estimated based on quantitation of sulfated glycosaminoglycan (sGAG) accumulation, immunohistochemistry of the presence and distribution of cartilage ECM proteins, and real-time RT-PCR analyis of mRNA expression of cartilage markers. Our results showed that COMP over-expression resulted in increased total sGAG content during the early phase of MSC chondrogenesis, and increased immuno-detectable levels of aggrecan and collagen type II in the ECM of COMP-transfected pellet and alginate cultures, indicating more abundant cartilaginous matrix. COMP transfection did not significantly increase the transcript levels of the early chondrogenic marker, Sox9, or aggrecan, suggesting that enhancement of MSC cartilage ECM was effected at post-transcriptional levels. These findings strongly suggest that COMP functions in mesenchymal chondrogenesis by enhancing cartilage ECM organization and assembly. The action of COMP is most likely mediated not via direct changes in cartilage matrix gene expression but via interactions of COMP with other cartilage ECM proteins, such as aggrecan and collagens, that result in enhanced assembly and retention. PMID:22095699

  8. Effect of Fibroblast Growth Factor 2 on Equine Synovial Fluid Chondroprogenitor Expansion and Chondrogenesis

    Directory of Open Access Journals (Sweden)

    Marta Bianchessi

    2016-01-01

    Full Text Available Mesenchymal stem cells have been identified in the synovial fluid of several species. This study was conducted to characterize chondroprogenitor (CP cells in equine synovial fluid (SF and to determine the effect of fibroblast growth factor 2 (FGF-2 on SF-CP monolayer proliferation and subsequent chondrogenesis. We hypothesized that FGF-2 would stimulate SF-CP proliferation and postexpansion chondrogenesis. SF aspirates were collected from adult equine joints. Colony-forming unit (CFU assays were performed during primary cultures. At first passage, SF-cells were seeded at low density, with or without FGF-2. Following monolayer expansion and serial immunophenotyping, cells were transferred to chondrogenic pellet cultures. Pellets were analyzed for chondrogenic mRNA expression and cartilage matrix secretion. There was a mean of 59.2 CFU/mL of SF. FGF-2 increased the number of population doublings during two monolayer passages and halved the population doubling times. FGF-2 did not alter the immunophenotype of SF-CPs during monolayer expansion, nor did FGF-2 compromise chondrogenesis. Hypertrophic phenotypic markers were not expressed in control or FGF-2 groups. FGF-2 did prevent the development of a “fibroblastic” cell layer around pellet periphery. FGF-2 significantly accelerates in vitro SF-CP expansion, the major hurdle to clinical application of this cell population, without detrimentally affecting subsequent chondrogenic capacity.

  9. The infrapatellar fat pad from diseased joints inhibits chondrogenesis of mesenchymal stem cells

    Directory of Open Access Journals (Sweden)

    W Wei

    2015-12-01

    Full Text Available Cartilage repair by bone marrow derived mesenchymal stem cells (MSCs can be influenced by inflammation in the knee. Next to synovium, the infrapatellar fat pad (IPFP has been described as a source for inflammatory factors. Here, we investigated whether factors secreted by the IPFP affect chondrogenesis of MSCs and whether this is influenced by different joint pathologies or obesity. Furthermore, we examined the role of IPFP resident macrophages. First, we made conditioned medium from IPFP obtained from osteoarthritic joints, IPFP from traumatically injured joints during anterior cruciate ligament reconstruction, and subcutaneous adipose tissue. Additionally, we made conditioned medium of macrophages isolated from osteoarthritic IPFP and of polarised monocytes from peripheral blood. We evaluated the effect of different types of conditioned medium on MSC chondrogenesis. Conditioned medium from IPFP decreased collagen 2 and aggrecan gene expression as well as thionin and collagen type 2 staining. This anti-chondrogenic effect was the same for conditioned medium from IPFP of osteoarthritic and traumatically injured joints. Furthermore, IPFP from obese (Body Mass Index >30 donors did not inhibit chondrogenesis more than that of lean (Body Mass Index <25 donors. Finally, conditioned medium from macrophages isolated from IPFP decreased the expression of hyaline cartilage genes, as did peripheral blood monocytes stimulated with pro-inflammatory cytokines. The IPFP and the resident pro-inflammatory macrophages could therefore be targets for therapies to improve MSC-based cartilage repair.

  10. Microenvironment is involved in cellular response to hydrostatic pressures during chondrogenesis of mesenchymal stem cells.

    Science.gov (United States)

    Ye, Rui; Hao, Jin; Song, Jinlin; Zhao, Zhihe; Fang, Shanbao; Wang, Yating; Li, Juan

    2014-06-01

    Chondrocytes integrate numerous microenvironmental cues to mount physiologically relevant differentiation responses, and the regulation of mechanical signaling in chondrogenic differentiation is now coming into intensive focus. To facilitate tissue-engineered chondrogenesis by mechanical strategy, a thorough understanding about the interactional roles of chemical factors under mechanical stimuli in regulating chondrogenesis is in great need. Therefore, this study attempts to investigate the interaction of rat MSCs with their microenvironment by imposing dynamic and static hydrostatic pressure through modulating gaseous tension above the culture medium. Under dynamic pressure, chemical parameters (pH, pO2, and pCO2) were kept in homeostasis. In contrast, pH was remarkably reduced due to increased pCO2 under static pressure. MSCs under the dynamically pressured microenvironment exhibited a strong accumulation of GAG within and outside the alginate beads, while cells under the statically pressured environment lost newly synthesized GAG into the medium with a speed higher than its production. In addition, the synergic influence on expression of chondrogenic genes was more persistent under dynamic pressure than that under static pressure. This temporal contrast was similar to that of activation of endogenous TGF-β1. Taken altogether, it indicates that a loading strategy which can keep a homeostatic chemical microenvironment is preferred, since it might sustain the stimulatory effects of mechanical stimuli on chondrogenesis via activation of endogenous TGF-β1. © 2013 Wiley Periodicals, Inc.

  11. Differentiation of stem cells from human infrapatellar fat pad: characterization of cells undergoing chondrogenesis.

    Science.gov (United States)

    Felimban, Raed; Ye, Ken; Traianedes, Kathy; Di Bella, Claudia; Crook, Jeremy; Wallace, Gordon G; Quigley, Anita; Choong, Peter F M; Myers, Damian E

    2014-08-01

    Hyaline cartilage repair is a significant challenge in orthopedics and current techniques result in formation of fibrocartilage. Human infrapatellar fat pad (hIPFP)-derived mesenchymal stem cells (MSCs) are capable of differentiation into multiple tissue lineages, including cartilage and bone. Chondrogenesis is a crucial part of normal skeletal development but the molecular mechanisms are yet to be completely defined. In this study we sourced hIPFP-derived MSCs utilizing chondrogenic growth factors, transforming growth factor beta-3, and bone morphogenetic protein-6, to form hyaline-like cartilage in micromass cultures and we studied chondrogenic development of 7, 14, and 28 days. The purpose of this study was (1) to characterize chondrogenesis from MSCs derived from hIPFP tissue by conventional techniques and (2) to characterize temporal changes of key molecular components during chondrogenesis using microarray gene expression. Endpoints included histology, immunohistochemistry (IHC), gene expression profiles using a microarray technique, and changes in expression of specific genes using quantitative real-time polymerase chain reaction. Over 14-28 days, clusters of encapsulated chondrocytes formed surrounded by collagen type II and aggrecan in the extracellular matrix (ECM). Collagen type II and aggrecan production was confirmed using IHC and chondrogenic lineage markers were studied; SRY-related transcription factor (SOX9), collagen type II alpha 1 (COL2A1), and aggrecan gene expression increased significantly over the time course. Normalized microarray highlighted 608 differentially expressed genes; 10 chondrogenic genes were upregulated (2- to 87-fold), including COL2A1, COL10A1, COL9A1, COL11A1, COL9A2, COL11A2, COL1A1, COMP, SOX9, and COL3A1. We found that the upregulated genes (twofold or greater) represent significant level of expression (enrichment score) for the ECM structural constituent of the molecular functional at days 7, 14, and 28 during

  12. Incorporation of hyaluronic acid into collagen scaffolds for the control of chondrocyte-mediated contraction and chondrogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Tang Shunqing [Department of Biomedical Engineering, Jinan University, Guangzhou 510632 (China); Spector, Myron [Tissue Engineering, VA Boston Healthcare System, Boston, MA 02130 (United States)

    2007-09-15

    Hyaluronic acid (HA), a principal matrix molecule in many tissues, is present in high amounts in articular cartilage. HA contributes in unique ways to the physical behavior of the tissue, and has been shown to have beneficial effects on chondrocyte activity. The goal of this study was to incorporate graduated amounts of HA into type I collagen scaffolds for the control of chondrocyte-mediated contraction and chondrogenesis in vitro. The results demonstrated that the amount of contraction of HA/collagen scaffolds by adult canine articular chondrocytes increased with the HA content of the scaffolds. The greatest amount of chondrogenesis after two weeks was found in the scaffolds which had undergone the most contraction. HA can play a useful role in adjusting the mechanical behavior of tissue engineering scaffolds and chondrogenesis in chondrocyte-seeded scaffolds.

  13. Chondrogenesis of human infrapatellar fat pad stem cells on acellular dermal matrix

    Directory of Open Access Journals (Sweden)

    Ken eYe

    2016-01-01

    Full Text Available Acellular dermal matrix (ADM has been in clinical use for decades in numerous surgical applications. The ability for ADM to promote cellular repopulation and revascularisation, and tissue regeneration is well documented. Adipose stem cells have the ability to differentiate into mesenchymal tissue types, including bone and cartilage. The aim of this study was to investigate the potential interaction between ADM and adipose stem cells in vitro using TGFβ3 and BMP6.Human infrapatellar fat pad derived adipose stem cells (IPFP-ASC were cultured with ADM derived from rat dermis under chondrogenic (TGFβ3 and BMP6 in vitro for 2 and 4 weeks. Histology, qPCR and immunohistochemistry were performed to assess for markers of chondrogenesis (collagen Type II, SOX9 and proteoglycans. At 4 weeks, cell-scaffold constructs displayed cellular changes consistent with chondrogenesis, with evidence of stratification of cell layers and development of a hyaline-like cartilage layer superficially which stained positively for collagen Type II and proteoglycans. Significant cell-matrix interaction was seen between the cartilage layer and the ADM itself with seamless integration between each layer. Real time qPCR showed significantly increases of COL2A1, SOX9, and ACAN gene expression over 4 weeks when compared to control. COL1A2 gene expression remained unchanged over 4 weeks.We believe the principles which make ADM versatile and successful for tissue regeneration are application to cartilage regeneration. This study demonstrates in vitro the ability for IPFP-ASCs to undergo chondrogenesis, infiltrate and interact with ADM. These outcomes serve as a platform for in vivo modelling of ADM for cartilage repair.

  14. Chondrogenesis of the branchial skeleton in embryonic sea lamprey, Petromyzon marinus.

    Science.gov (United States)

    Morrison, S L; Campbell, C K; Wright, G M

    2000-11-01

    This study provides concise temporal and spatial characteristics of branchial chondrogenesis in embryonic sea lamprey, Petromyzon marinus, using high resolution light microscopy, transmission electron, and immunoelectron microscopy. Prechondrogenic condensations representing the first branchial arch appeared first in the mid-region of the third pharyngeal arch at 13 days post-fertilization (pf). Cartilage differentiation, defined by the presence of the unique, fibrillar, non-collagenous matrix protein characteristic of branchial cartilage, was first observed at 14 days pf. Development of lamprey branchial cartilage appeared unusual compared to that in jawed fishes, in that precartilage condensations appear as a one-cell wide orderly stack of flattened cells that extend by the addition of one dorsal and one ventral condensation. Development of lamprey gill arches from three condensations that fuse to form a single skeletal element differs from the developing gill arches of jawed fishes, where more than one skeletal element forms from a single condensation. The initial orderly arrangement of cells in the lamprey branchial prechondrogenic condensations remains throughout development. Once chondrification of the condensations begins, the branchial arches start to grow. Initially, growth occurs as a result of matrix secretion and cell migration. Later in development, the arches grow mainly by cell proliferation and enlargement. This study defines the morphology and timing of lamprey branchial chondrogenesis. Studies of lamprey chondrogenesis provide not only insight into the developmental biology of a unique non-collagenous cartilage in a primitive vertebrate but also into the general evolution of the skeletal system in vertebrates. Copyright 2000 Wiley-Liss, Inc.

  15. In Vivo Chondrogenesis in 3D Bioprinted Human Cell-laden Hydrogel Constructs

    OpenAIRE

    M?ller, Thomas; Amoroso, Matteo; H?gg, Daniel; Brantsing, Camilla; Rotter, Nicole; Apelgren, Peter; Lindahl, Anders; K?lby, Lars; Gatenholm, Paul

    2017-01-01

    Background: The three-dimensional (3D) bioprinting technology allows creation of 3D constructs in a layer-by-layer fashion utilizing biologically relevant materials such as biopolymers and cells. The aim of this study is to investigate the use of 3D bioprinting in a clinically relevant setting to evaluate the potential of this technique for in vivo chondrogenesis. Methods: Thirty-six nude mice (Balb-C, female) received a 5- ? 5- ? 1-mm piece of bioprinted cell-laden nanofibrillated cellulose/...

  16. In vitro chondrogenesis with lysozyme susceptible bacterial cellulose as a scaffold.

    Science.gov (United States)

    Yadav, Vikas; Sun, Lin; Panilaitis, Bruce; Kaplan, David L

    2015-12-01

    A current focus of tissue engineering is the use of adult human mesenchymal stem cells (hMSCs) as an alternative to autologous chondrocytes for cartilage repair. Several natural and synthetic polymers (including cellulose) have been explored as a biomaterial scaffold for cartilage tissue engineering. While bacterial cellulose (BC) has been used in tissue engineering, its lack of degradability in vivo and high crystallinity restricts widespread applications in the field. Recently we reported the formation of a novel bacterial cellulose that is lysozyme-susceptible and -degradable in vivo from metabolically engineered Gluconacetobacter xylinus. Here we report the use of this modified bacterial cellulose (MBC) for cartilage tissue engineering using hMSCs. MBC's glucosaminoglycan-like chemistry, combined with in vivo degradability, suggested opportunities to exploit this novel polymer in cartilage tissue engineering. We have observed that, like BC, MBC scaffolds support cell attachment and proliferation. Chondrogenesis of hMSCs in the MBC scaffolds was demonstrated by real-time RT-PCR analysis for cartilage-specific extracellular matrix (ECM) markers (collagen type II, aggrecan and SOX9) as well as histological and immunohistochemical evaluations of cartilage-specific ECM markers. Further, the attachment, proliferation, and differentiation of hMSCs in MBC showed unique characteristics. For example, after 4 weeks of cultivation, the spatial cell arrangement and collagen type-II and ACAN distribution resembled those in native articular cartilage tissue, suggesting promise for these novel in vivo degradable scaffolds for chondrogenesis. Copyright © 2013 John Wiley & Sons, Ltd.

  17. The enhancement of chondrogenesis of ATDC5 cells in RGD-immobilized microcavitary alginate hydrogels.

    Science.gov (United States)

    Yao, Yongchang; Zeng, Lei; Huang, Yuyang

    2016-07-01

    In our previous work, we have developed an effective microcavitary alginate hydrogel for proliferation of chondrocytes and maintenance of chondrocytic phenotype. In present work, we investigated whether microcavitary alginate hydrogel could promote the chondrogenesis of progenitor cells. Moreover, we attempted to further optimize this system by incorporating synthetic Arg-Gly-Asp peptide. ATDC5 cells were seeded into microcavitary alginate hydrogel with or without Arg-Gly-Asp immobilization. Cell Counting Kit-8 and live/dead staining were conducted to analyze cell proliferation. Real-time polymerase chain reaction (RT-PCR), hematoxylin and eosin, and Toluidine blue O staining as well as Western blot assay was performed to evaluate the cartilaginous markers at transcriptional level and at protein level, respectively. The obtained data demonstrated that Arg-Gly-Asp-immobilized microcavitary alginate hydrogel was preferable to promote the cell proliferation. Also, Arg-Gly-Asp-immobilized microcavitary alginate hydrogel improved the expression of chondrocytic genes including Collagen II and Aggrecan when compared with microcavitary alginate hydrogel. The results suggested that microcavitary alginate hydrogel could promote the chondrogenesis. And Arg-Gly-Asp would be promising to ameliorate this culture system for cartilage tissue engineering. © The Author(s) 2016.

  18. Biomimetic alginate/polyacrylamide porous scaffold supports human mesenchymal stem cell proliferation and chondrogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Peng [Department of ENT-Head and Neck Surgery, EENT Hospital, Shanghai 200031 (China); Shanghai Medical School, Fudan University, 210029 (China); Yuan, Yasheng, E-mail: yuanyasheng@163.com [Department of ENT-Head and Neck Surgery, EENT Hospital, Shanghai 200031 (China); Shanghai Medical School, Fudan University, 210029 (China); Eaton-Peabody Laboratory, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA 02114 (United States); Chi, Fanglu [Department of ENT-Head and Neck Surgery, EENT Hospital, Shanghai 200031 (China); Shanghai Medical School, Fudan University, 210029 (China)

    2014-09-01

    We describe the development of alginate/polyacrylamide (ALG/PAAm) porous hydrogels based on interpenetrating polymer network structure for human mesenchymal stem cell proliferation and chondrogenesis. Three ALG/PAAm hydrogels at molar ratios of 10/90, 20/80, and 30/70 were prepared and characterized with enhanced elastic and rubbery mechanical properties, which are similar to native human cartilage tissues. Their elasticity and swelling properties were also studied under different physiological pH conditions. Finally, in vitro tests demonstrated that human mesenchymal stem cells could proliferate on the as-synthesized hydrogels with improved alkaline phosphatase activities. These results suggest that ALG/PAAm hydrogels may be a promising biomaterial for cartilage tissue engineering. - Highlights: • ALG/PAAm hydrogels were prepared at different molar ratios for cartilage tissue engineering. • ALG/PAAm hydrogels feature an interpenetrating polymer network structure. • ALG/PAAm hydrogels demonstrate strengthened elastic and rubbery mechanical properties. • hMSCs could be cultured on the ALG/PAAm hydrogels for proliferation and chondrogenesis.

  19. Biomimetic alginate/polyacrylamide porous scaffold supports human mesenchymal stem cell proliferation and chondrogenesis

    International Nuclear Information System (INIS)

    Guo, Peng; Yuan, Yasheng; Chi, Fanglu

    2014-01-01

    We describe the development of alginate/polyacrylamide (ALG/PAAm) porous hydrogels based on interpenetrating polymer network structure for human mesenchymal stem cell proliferation and chondrogenesis. Three ALG/PAAm hydrogels at molar ratios of 10/90, 20/80, and 30/70 were prepared and characterized with enhanced elastic and rubbery mechanical properties, which are similar to native human cartilage tissues. Their elasticity and swelling properties were also studied under different physiological pH conditions. Finally, in vitro tests demonstrated that human mesenchymal stem cells could proliferate on the as-synthesized hydrogels with improved alkaline phosphatase activities. These results suggest that ALG/PAAm hydrogels may be a promising biomaterial for cartilage tissue engineering. - Highlights: • ALG/PAAm hydrogels were prepared at different molar ratios for cartilage tissue engineering. • ALG/PAAm hydrogels feature an interpenetrating polymer network structure. • ALG/PAAm hydrogels demonstrate strengthened elastic and rubbery mechanical properties. • hMSCs could be cultured on the ALG/PAAm hydrogels for proliferation and chondrogenesis

  20. THRAP3 interacts with and inhibits the transcriptional activity of SOX9 during chondrogenesis.

    Science.gov (United States)

    Sono, Takashi; Akiyama, Haruhiko; Miura, Shigenori; Deng, Jian Min; Shukunami, Chisa; Hiraki, Yuji; Tsushima, Yu; Azuma, Yoshiaki; Behringer, Richard R; Matsuda, Shuichi

    2018-07-01

    Sex-determining region Y (Sry)-box (Sox)9 is required for chondrogenesis as a transcriptional activator of genes related to chondrocyte proliferation, differentiation, and cartilage-specific extracellular matrix. Although there have been studies investigating the Sox9-dependent transcriptional complexes, not all their components have been identified. In the present study, we demonstrated that thyroid hormone receptor-associated protein (THRAP)3 is a component of a SOX9 transcriptional complex by liquid chromatography mass spectrometric analysis of FLAG-tagged Sox9-binding proteins purified from FLAG-HA-tagged Sox9 knock-in mice. Thrap3 knockdown in ATDC5 chondrogenic cells increased the expression of Collagen type II alpha 1 chain (Col2a1) without affecting Sox9 expression. THRAP3 and SOX9 overexpression reduced Col2a1 levels to a greater degree than overexpression of SOX9 alone. The negative regulation of SOX9 transcriptional activity by THRAP3 was mediated by interaction between the proline-, glutamine-, and serine-rich domain of SOX9 and the innominate domain of THRAP3. These results indicate that THRAP3 negatively regulates SOX9 transcriptional activity as a cofactor of a SOX9 transcriptional complex during chondrogenesis.

  1. Chondrogenesis of infrapatellar fat pad derived adipose stem cells in 3D printed chitosan scaffold.

    Science.gov (United States)

    Ye, Ken; Felimban, Raed; Traianedes, Kathy; Moulton, Simon E; Wallace, Gordon G; Chung, Johnson; Quigley, Anita; Choong, Peter F M; Myers, Damian E

    2014-01-01

    Infrapatellar fat pad adipose stem cells (IPFP-ASCs) have been shown to harbor chondrogenic potential. When combined with 3D polymeric structures, the stem cells provide a source of stem cells to engineer 3D tissues for cartilage repair. In this study, we have shown human IPFP-ASCs seeded onto 3D printed chitosan scaffolds can undergo chondrogenesis using TGFβ3 and BMP6. By week 4, a pearlescent, cartilage-like matrix had formed that penetrated the top layers of the chitosan scaffold forming a 'cap' on the scaffold. Chondrocytic morphology showed typical cells encased in extracellular matrix which stained positively with toluidine blue. Immunohistochemistry demonstrated positive staining for collagen type II and cartilage proteoglycans, as well as collagen type I. Real time PCR analysis showed up-regulation of collagen type II, aggrecan and SOX9 genes when IPFP-ASCs were stimulated by TGFβ3 and BMP6. Thus, IPFP-ASCs can successfully undergo chondrogenesis using TGFβ3 and BMP6 and the cartilage-like tissue that forms on the surface of 3D-printed chitosan scaffold may prove useful as an osteochondral graft.

  2. Chondrogenesis of infrapatellar fat pad derived adipose stem cells in 3D printed chitosan scaffold.

    Directory of Open Access Journals (Sweden)

    Ken Ye

    Full Text Available Infrapatellar fat pad adipose stem cells (IPFP-ASCs have been shown to harbor chondrogenic potential. When combined with 3D polymeric structures, the stem cells provide a source of stem cells to engineer 3D tissues for cartilage repair. In this study, we have shown human IPFP-ASCs seeded onto 3D printed chitosan scaffolds can undergo chondrogenesis using TGFβ3 and BMP6. By week 4, a pearlescent, cartilage-like matrix had formed that penetrated the top layers of the chitosan scaffold forming a 'cap' on the scaffold. Chondrocytic morphology showed typical cells encased in extracellular matrix which stained positively with toluidine blue. Immunohistochemistry demonstrated positive staining for collagen type II and cartilage proteoglycans, as well as collagen type I. Real time PCR analysis showed up-regulation of collagen type II, aggrecan and SOX9 genes when IPFP-ASCs were stimulated by TGFβ3 and BMP6. Thus, IPFP-ASCs can successfully undergo chondrogenesis using TGFβ3 and BMP6 and the cartilage-like tissue that forms on the surface of 3D-printed chitosan scaffold may prove useful as an osteochondral graft.

  3. Discovery of novel differentiation markers in the early stage of chondrogenesis by glycoform-focused reverse proteomics and genomics.

    Science.gov (United States)

    Ishihara, Takeshi; Kakiya, Kiyoshi; Takahashi, Koji; Miwa, Hiroto; Rokushima, Masatomo; Yoshinaga, Tomoyo; Tanaka, Yoshikazu; Ito, Takaomi; Togame, Hiroko; Takemoto, Hiroshi; Amano, Maho; Iwasaki, Norimasa; Minami, Akio; Nishimura, Shin-Ichiro

    2014-01-01

    Osteoarthritis (OA) is one of the most common chronic diseases among adults, especially the elderly, which is characterized by destruction of the articular cartilage. Despite affecting more than 100 million individuals all over the world, therapy is currently limited to treating pain, which is a principal symptom of OA. New approaches to the treatment of OA that induce regeneration and repair of cartilage are strongly needed. To discover potent markers for chondrogenic differentiation, glycoform-focused reverse proteomics and genomics were performed on the basis of glycoblotting-based comprehensive approach. Expression levels of high-mannose type N-glycans were up-regulated significantly at the late stage of differentiation of the mouse chondroprogenitor cells. Among 246 glycoproteins carrying this glycotype identified by ConA affinity chromatography and LC/MS, it was demonstrated that 52% are classified as cell surface glycoproteins. Gene expression levels indicated that mRNAs for 15 glycoproteins increased distinctly in the earlier stages during differentiation compared with Type II collagen. The feasibility of mouse chondrocyte markers in human chondrogenesis model was demonstrated by testing gene expression levels of these 15 glycoproteins during differentiation in human mesenchymal stem cells. The results showed clearly an evidence of up-regulation of 5 genes, ectonucleotide pyrophosphatase/phosphodiesterase family member 1, collagen alpha-1(III) chain, collagen alpha-1(XI) chain, aquaporin-1, and netrin receptor UNC5B, in the early stages of differentiation. These cell surface 5 glycoproteins become highly sensitive differentiation markers of human chondrocytes that contribute to regenerative therapies, and development of novel therapeutic reagents. © 2013.

  4. Platelet lysate 3D scaffold supports mesenchymal stem cell chondrogenesis: an improved approach in cartilage tissue engineering.

    Science.gov (United States)

    Moroz, Andrei; Bittencourt, Renata Aparecida Camargo; Almeida, Renan Padron; Felisbino, Sérgio Luis; Deffune, Elenice

    2013-01-01

    Articular lesions are still a major challenge in orthopedics because of cartilage's poor healing properties. A major improvement in therapeutics was the development of autologous chondrocytes implantation (ACI), a biotechnology-derived technique that delivers healthy autologous chondrocytes after in vitro expansion. To obtain cartilage-like tissue, 3D scaffolds are essential to maintain chondrocyte differentiated status. Currently, bioactive 3D scaffolds are promising as they can deliver growth factors, cytokines, and hormones to the cells, giving them a boost to attach, proliferate, induce protein synthesis, and differentiate. Using mesenchymal stem cells (MSCs) differentiated into chondrocytes, one can avoid cartilage harvesting. Thus, we investigated the potential use of a platelet-lysate-based 3D bioactive scaffold to support chondrogenic differentiation and maintenance of MSCs. The MSCs from adult rabbit bone marrow (n = 5) were cultivated and characterized using three antibodies by flow cytometry. MSCs (1 × 10(5)) were than encapsulated inside 60 µl of a rabbit platelet-lysate clot scaffold and maintained in Dulbecco's Modified Eagle Medium Nutrient Mixture F-12 supplemented with chondrogenic inductors. After 21 days, the MSCs-seeded scaffolds were processed for histological analysis and stained with toluidine blue. This scaffold was able to maintain round-shaped cells, typical chondrocyte metachromatic extracellular matrix deposition, and isogenous group formation. Cells accumulated inside lacunae and cytoplasm lipid droplets were other observed typical chondrocyte features. In conclusion, the usage of a platelet-lysate bioactive scaffold, associated with a suitable chondrogenic culture medium, supports MSCs chondrogenesis. As such, it offers an alternative tool for cartilage engineering research and ACI.

  5. Promoted Chondrogenesis of Cocultured Chondrocytes and Mesenchymal Stem Cells under Hypoxia Using In-situ Forming Degradable Hydrogel Scaffolds

    NARCIS (Netherlands)

    Huang, Xiaobin; Hou, Yong; Zhong, Leilei; Huang, Dechun; Qian, Hongliang; Karperien, Marcel; Chen, Wei

    2018-01-01

    We investigated the effects of different oxygen tension (21% and 2.5% O2) on the chondrogenesis of different cell systems cultured in pH-degradable PVA hydrogels, including human articular chondrocytes (hACs), human mesenchymal stem cells (hMSCs), and their cocultures with a hAC/hMSC ratio of 20/80.

  6. Cellular ATP synthesis mediated by type III sodium-dependent phosphate transporter Pit-1 is critical to chondrogenesis.

    Science.gov (United States)

    Sugita, Atsushi; Kawai, Shinji; Hayashibara, Tetsuyuki; Amano, Atsuo; Ooshima, Takashi; Michigami, Toshimi; Yoshikawa, Hideki; Yoneda, Toshiyuki

    2011-01-28

    Disturbed endochondral ossification in X-linked hypophosphatemia indicates an involvement of P(i) in chondrogenesis. We studied the role of the sodium-dependent P(i) cotransporters (NPT), which are a widely recognized regulator of cellular P(i) homeostasis, and the downstream events in chondrogenesis using Hyp mice, the murine homolog of human X-linked hypophosphatemia. Hyp mice showed reduced apoptosis and mineralization in hypertrophic cartilage. Hyp chondrocytes in culture displayed decreased apoptosis and mineralization compared with WT chondrocytes, whereas glycosaminoglycan synthesis, an early event in chondrogenesis, was not altered. Expression of the type III NPT Pit-1 and P(i) uptake were diminished, and intracellular ATP levels were also reduced in parallel with decreased caspase-9 and caspase-3 activity in Hyp chondrocytes. The competitive NPT inhibitor phosphonoformic acid and ATP synthesis inhibitor 3-bromopyruvate disturbed endochondral ossification with reduced apoptosis in vivo and suppressed apoptosis and mineralization in conjunction with reduced P(i) uptake and ATP synthesis in WT chondrocytes. Overexpression of Pit-1 in Hyp chondrocytes reversed P(i) uptake and ATP synthesis and restored apoptosis and mineralization. Our results suggest that cellular ATP synthesis consequent to P(i) uptake via Pit-1 plays an important role in chondrocyte apoptosis and mineralization, and that chondrogenesis is ATP-dependent.

  7. Glycosylation of DMP1 Is Essential for Chondrogenesis of Condylar Cartilage.

    Science.gov (United States)

    Weng, Y; Liu, Y; Du, H; Li, L; Jing, B; Zhang, Q; Wang, X; Wang, Z; Sun, Y

    2017-12-01

    The mandibular condylar cartilage (MCC) shoulders force for the subchondral bone during mastication. The cartilage matrix contains various large molecules, such as type I, II, and X collagens and proteoglycans (PGs), which jointly play essential roles in maintaining cartilage characteristics. PGs play key roles in maintaining the elasticity of cartilage and providing a cushion against mastication forces. In addition to the well-known PGs, DMP1-PG, which is the PG form of dentin matrix protein 1 (DMP1), is a newly identified PG. DMP1 is proteolytically processed in vivo, and the N-terminus is glycosylated into its PG form-that is, DMP1-PG, which is highly expressed not only in tooth and bone but also in the matrix of the MCC. However, the specific functions of DMP1-PG in the MCC remain unclear. In human temporomandibular joint osteoarthritis and hyperocclusion model rat specimens, PGs are significantly downregulated, and DMP1-PG is the most prominently affected PG. To further investigate the role of DMP1-PG in condylar chondrogenesis, a glycosylation site mutant (S 89 -G 89 ) mouse model was established with knock-in methods. In the MCC of the S89G-DMP1 mice, the glycosylation level of DMP1 was significantly downregulated, and a series of abnormal developmental and pathologic changes could be observed. The morphologic changes included thinner cartilage layers, deformations of the MCC, and disordered arrangements of the chondrocytes, and an earlier onset of temporomandibular joint osteoarthritis-like changes was observed. In addition, markers of chondrogenesis were downregulated, and the matrix of the MCC displayed OA phenotypes in the S89G-DMP1 mice. Further investigations showed that the transforming growth factor β signaling molecules were affected in the MCC after the loss of DMP1-PG. In addition, the loss of DMP1-PG significantly accelerated the progression of cartilage injuries in the hyperocclusion models. Given these findings, we investigated the significant

  8. Optimized chondrogenesis of ATCD5 cells through sequential regulation of oxygen conditions

    DEFF Research Database (Denmark)

    Chen, Li; Fink, Trine; Ebbesen, Peter

    2006-01-01

    , chondrocyte-specific extracellular matrix (ECM) production was monitored. Furthermore, the transcription of collagen II, an early-phase marker, and collagen X, a marker of hypertrophic conversion, was followed by real-time RT-PCR. Low oxygen concentrations between 1 and 9% inhibited chondrogenic conversion......, as evidenced by reduced glycosaminoglycan deposition in the ECM in a manner proportional to the degree of hypoxia. Cells cultured at oxygen concentrations of 12 and 15% underwent a faster and higher degree of early-phase chondrogenesis when compared to control cells cultured at ambient air (21% O2......). For the hypertrophic conversion of the ATDC5 cells, all degrees of hypoxia inhibited collagen X expression in a dose-dependent manner. Short-term culturing of the ATDC5 cells for 6 to 8 days at 12% oxygen with subsequent culturing at 21% for the remainder of the experiment resulted in maximal production of major ECM...

  9. Gene Modification of Mesenchymal Stem Cells and Articular Chondrocytes to Enhance Chondrogenesis

    Directory of Open Access Journals (Sweden)

    Saliya Gurusinghe

    2014-01-01

    Full Text Available Current cell based treatment for articular cartilage and osteochondral defects are hampered by issues such as cellular dedifferentiation and hypertrophy of the resident or transplanted cells. The reduced expression of chondrogenic signalling molecules and transcription factors is a major contributing factor to changes in cell phenotype. Gene modification of chondrocytes may be one approach to redirect cells to their primary phenotype and recent advances in nonviral and viral gene delivery technologies have enabled the expression of these lost factors at high efficiency and specificity to regain chondrocyte function. This review focuses on the various candidate genes that encode signalling molecules and transcription factors that are specific for the enhancement of the chondrogenic phenotype and also how epigenetic regulators of chondrogenesis in the form of microRNA may also play an important role.

  10. In Vivo Chondrogenesis in 3D Bioprinted Human Cell-laden Hydrogel Constructs.

    Science.gov (United States)

    Möller, Thomas; Amoroso, Matteo; Hägg, Daniel; Brantsing, Camilla; Rotter, Nicole; Apelgren, Peter; Lindahl, Anders; Kölby, Lars; Gatenholm, Paul

    2017-02-01

    The three-dimensional (3D) bioprinting technology allows creation of 3D constructs in a layer-by-layer fashion utilizing biologically relevant materials such as biopolymers and cells. The aim of this study is to investigate the use of 3D bioprinting in a clinically relevant setting to evaluate the potential of this technique for in vivo chondrogenesis. Thirty-six nude mice (Balb-C, female) received a 5- × 5- × 1-mm piece of bioprinted cell-laden nanofibrillated cellulose/alginate construct in a subcutaneous pocket. Four groups of printed constructs were used: (1) human (male) nasal chondrocytes (hNCs), (2) human (female) bone marrow-derived mesenchymal stem cells (hBMSCs), (3) coculture of hNCs and hBMSCs in a 20/80 ratio, and (4) Cell-free scaffolds (blank). After 14, 30, and 60 days, the scaffolds were harvested for histological, immunohistochemical, and mechanical analysis. The constructs had good mechanical properties and keep their structural integrity after 60 days of implantation. For both the hNC constructs and the cocultured constructs, a gradual increase of glycosaminoglycan production and hNC proliferation was observed. However, the cocultured group showed a more pronounced cell proliferation and enhanced deposition of human collagen II demonstrated by immunohistochemical analysis. In vivo chondrogenesis in a 3D bioprinted human cell-laden hydrogel construct has been demonstrated. The trophic role of the hBMSCs in stimulating hNC proliferation and matrix deposition in the coculture group suggests the potential of 3D bioprinting of human cartilage for future application in reconstructive surgery.

  11. Small Molecule-BIO Accelerates and Enhances Marrow-Derived Mesenchymal Stem Cell in Vitro Chondrogenesis

    Directory of Open Access Journals (Sweden)

    Mohamadreza Baghaban Eslaminejad

    2014-03-01

    Full Text Available Background: Hyaline cartilage defects exhibit a major challenge in the field of orthopedic surgery owing to its limited repair capacity. On the other hand, mesenchymal stem cells (MSCs are regarded as potent cells with a property of cartilage regeneration. We aimed to optimize marrow-derived MSC chondrogenic culture using a small bioactive molecule referred to as BIO. Methods: MSCs from the marrow of NMRI mice were extracted, culture-expanded, and characterized. Micro-mass culture was then established for chondrogenic differentiation (control group. The cultures of MSC in chondrogenic medium supplemented with 0.01, 0.05, 0.1, and 1 µM BIO were taken as the experimental groups. Cartilage differentiation was examined by both histological sections and real-time PCR for Sox9, aggrecan, and collagen II at different time points. Moreover, the involvement of the Wnt pathway was investigated. Results: Based on histological sections, there was seemingly more intense metachromatic matrix produced in the cultures with 0.01 µM BIO. In this experimental group, cartilage-specific genes tended to be upregulated at day 14 compared to day 21 of the control group, indicating the accelerating effect of BIO on cartilage differentiation. Overall, there was statistically a significant increase (P=0.01 in the expression level of cartilage-specific genes in cultures with 0.01 µM BIO (enhancing effects. These upregulations appeared to be mediated through the Wnt pathway evident from the significant upregulation of T-cell factor and beta-catenin molecules (P=0.01. Conclusion: Taken together, BIO at 0.01 µM could accelerate and enhance in vitro chondrogenesis of mouse marrow-derived MSCs. Please cite this article as: Baghaban Eslaminejad MR, Fallah N. Small Molecule-BIO Accelerates and Enhances Marrow-Derived Mesenchymal Stem Cell in Vitro Chondrogenesis. Iran J Med Sci. 2014;39(2:107-116.

  12. Effects of platelet rich plasma and chondrocyte co-culture on MSC chondrogenesis, hypertrophy and pathological responses

    OpenAIRE

    Ramezanifard, Rouhallah; Kabiri, Mahboubeh; Hanaee Ahvaz, Hana

    2017-01-01

    Regarding the inadequate healing capability of cartilage tissue, cell-based therapy is making the future of cartilage repair and regeneration. Mesenchymal stem cells (MSC) have shown great promise in cartilage regeneration. However, a yet-unresolved issue is the emergence of hypertrophic and pathologic markers during in vitro MSC chondrogenesis. Articular chondrocytes (AC) can suppress the undesired hypertrophy when co-cultured with MSC. On the other hand, platelet rich plasma (PRP), is consi...

  13. Intermittent PTHrP(1–34) Exposure Augments Chondrogenesis and Reduces Hypertrophy of Mesenchymal Stromal Cells

    Science.gov (United States)

    Fischer, Jennifer; Aulmann, Antje; Dexheimer, Verena; Grossner, Tobias

    2014-01-01

    Phenotype instability and premature hypertrophy prevent the use of human mesenchymal stromal cells (MSCs) for cartilage regeneration. Aim of this study was to investigate whether intermittent supplementation of parathyroid hormone-related protein (PTHrP), as opposed to constant treatment, can beneficially influence MSC chondrogenesis and to explore molecular mechanisms below catabolic and anabolic responses. Human MSCs subjected to chondrogenic induction in high-density culture received PTHrP(1–34), forskolin, dbcAMP, or PTHrP(7–34) either constantly or via 6-h pulses (three times weekly), before proteoglycan, collagen type II, and X deposition; gene expression; and alkaline phosphatase (ALP) activity were assessed. While constant application of PTHrP(1–34) suppressed chondrogenesis of MSCs, pulsed application significantly increased collagen type 2 (COL2A1) gene expression and the collagen type II, proteoglycan, and DNA content of pellets after 6 weeks. Collagen type 10 (COL10A1) gene expression was little affected but Indian hedgehog (IHH) expression and ALP activity were significantly downregulated by pulsed PTHrP. A faster response to PTHrP exposure was recorded for ALP activity over COL2A1 regulation, suggesting that signal duration is critical for catabolic versus anabolic reactions. Stimulation of cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA) signaling by forskolin reproduced major effects of both treatment modes, whereas application of PTHrP(7–34) capable of protein kinase C (PKC) signaling was ineffective. Pulsed PTHrP exposure of MSCs stimulated chondrogenesis and reduced endochondral differentiation apparently uncoupling chondrogenic matrix deposition from hypertrophic marker expression. cAMP/PKA was the major signaling pathway triggering the opposing effects of both treatment modes. Intermittent application of PTHrP represents an important novel means to improve chondrogenesis of MSCs and may be considered as a supporting clinical

  14. Matrilin-3 Chondrodysplasia Mutations Cause Attenuated Chondrogenesis, Premature Hypertrophy and Aberrant Response to TGF-β in Chondroprogenitor Cells

    OpenAIRE

    Chathuraka T. Jayasuriya; Fiona H. Zhou; Ming Pei; Zhengke Wang; Nicholas J. Lemme; Paul Haines; Qian Chen

    2014-01-01

    Studies have shown that mutations in the matrilin-3 gene (MATN3) are associated with multiple epiphyseal dysplasia (MED) and spondyloepimetaphyseal dysplasia (SEMD). We tested whether MATN3 mutations affect the differentiation of chondroprogenitor and/or mesenchymal stem cells, which are precursors to chondrocytes. ATDC5 chondroprogenitors stably expressing wild-type (WT) MATN3 underwent spontaneous chondrogenesis. Expression of chondrogenic markers collagen II and aggrecan was inhibited in c...

  15. Biological and Chemical Removal of Primary Cilia Affects Mechanical Activation of Chondrogenesis Markers in Chondroprogenitors and Hypertrophic Chondrocytes.

    Science.gov (United States)

    Deren, Matthew E; Yang, Xu; Guan, Yingjie; Chen, Qian

    2016-02-04

    Chondroprogenitors and hypertrophic chondrocytes, which are the first and last stages of the chondrocyte differentiation process, respectively, are sensitive to mechanical signals. We hypothesize that the mechanical sensitivity of these cells depends on the cell surface primary cilia. To test this hypothesis, we removed the primary cilia by biological means with transfection with intraflagellar transport protein 88 (IFT88) siRNA or by chemical means with chloral hydrate treatment. Transfection of IFT88 siRNA significantly reduced the percentage of ciliated cells in both chondroprogenitor ATDC5 cells as well as primary hypertrophic chondrocytes. Cyclic loading (1 Hz, 10% matrix deformation) of ATDC5 cells in three-dimensional (3D) culture stimulates the mRNA levels of chondrogenesis marker Type II collagen (Col II), hypertrophic chondrocyte marker Type X collagen (Col X), and a molecular regulator of chondrogenesis and chondrocyte hypertrophy bone morphogenetic protein 2 (BMP-2). The reduction of ciliated chondroprogenitors abolishes mechanical stimulation of Col II, Col X, and BMP-2. In contrast, cyclic loading stimulates Col X mRNA levels in hypertrophic chondrocytes, but not those of Col II and BMP-2. Both biological and chemical reduction of ciliated hypertrophic chondrocytes reduced but failed to abolish mechanical stimulation of Col X mRNA levels. Thus, primary cilia play a major role in mechanical stimulation of chondrogenesis and chondrocyte hypertrophy in chondroprogenitor cells and at least a partial role in hypertrophic chondrocytes.

  16. Limitations of using aggrecan and type X collagen as markers of chondrogenesis in mesenchymal stem cell differentiation.

    Science.gov (United States)

    Mwale, Fackson; Stachura, Dorothy; Roughley, Peter; Antoniou, John

    2006-08-01

    The study was initially designed to differentiate human bone marrow-derived mesenchymal stem cells (MSC) into chondrocyte-like cells, for use in tissue engineering. We cultured MSCs in defined chondrogenic medium as pellet cultures supplemented with transforming growth factor (TGF)-beta1 or -beta3 and dexamethazone, as they are commonly used to promote in vitro chondrogenesis. Markers of chondrogenesis used were type II collagen and aggrecan, with type X collagen being used as a marker of late-stage chondrocyte hypertrophy (associated with endochondral ossification). Our results show that aggrecan is constitutively expressed by MSCs and that type X collagen is expressed as an early event. Furthermore, we found that type X collagen was expressed before type II collagen in some cases. This is surprising because it is understood that stem cells have to be differentiated into chondrocytes before they can become hypertrophic. Thus, caution must be exercised when using aggrecan and type X collagen as markers for chondrogenesis and chondrocyte hypertrophy, respectively, in association with stem cell differentiation from this source.

  17. Biological and Chemical Removal of Primary Cilia Affects Mechanical Activation of Chondrogenesis Markers in Chondroprogenitors and Hypertrophic Chondrocytes

    Directory of Open Access Journals (Sweden)

    Matthew E. Deren

    2016-02-01

    Full Text Available Chondroprogenitors and hypertrophic chondrocytes, which are the first and last stages of the chondrocyte differentiation process, respectively, are sensitive to mechanical signals. We hypothesize that the mechanical sensitivity of these cells depends on the cell surface primary cilia. To test this hypothesis, we removed the primary cilia by biological means with transfection with intraflagellar transport protein 88 (IFT88 siRNA or by chemical means with chloral hydrate treatment. Transfection of IFT88 siRNA significantly reduced the percentage of ciliated cells in both chondroprogenitor ATDC5 cells as well as primary hypertrophic chondrocytes. Cyclic loading (1 Hz, 10% matrix deformation of ATDC5 cells in three-dimensional (3D culture stimulates the mRNA levels of chondrogenesis marker Type II collagen (Col II, hypertrophic chondrocyte marker Type X collagen (Col X, and a molecular regulator of chondrogenesis and chondrocyte hypertrophy bone morphogenetic protein 2 (BMP-2. The reduction of ciliated chondroprogenitors abolishes mechanical stimulation of Col II, Col X, and BMP-2. In contrast, cyclic loading stimulates Col X mRNA levels in hypertrophic chondrocytes, but not those of Col II and BMP-2. Both biological and chemical reduction of ciliated hypertrophic chondrocytes reduced but failed to abolish mechanical stimulation of Col X mRNA levels. Thus, primary cilia play a major role in mechanical stimulation of chondrogenesis and chondrocyte hypertrophy in chondroprogenitor cells and at least a partial role in hypertrophic chondrocytes.

  18. Human articular chondrocytes secrete parathyroid hormone-related protein and inhibit hypertrophy of mesenchymal stem cells in coculture during chondrogenesis.

    Science.gov (United States)

    Fischer, J; Dickhut, A; Rickert, M; Richter, W

    2010-09-01

    The use of bone marrow-derived mesenchymal stem cells (MSCs) has shown promise in cell-based cartilage regeneration. A yet-unsolved problem, however, is the unwanted up-regulation of markers of hypertrophy, such as alkaline phosphatase (AP) and type X collagen, during in vitro chondrogenesis and the formation of unstable calcifying cartilage at heterotopic sites. In contrast, articular chondrocytes produce stable, nonmineralizing cartilage. The aim of this study was to address whether coculture of MSCs with human articular chondrocytes (HACs) can suppress the undesired hypertrophy in differentiating MSCs. MSCs were differentiated in chondrogenic medium that had or had not been conditioned by parallel culture with HAC pellets, or MSCs were mixed in the same pellet with the HACs (1:1 or 1:2 ratio) and cultured for 6 weeks. Following in vitro differentiation, the pellets were transplanted into SCID mice. The gene expression ratio of COL10A1 to COL2A1 and of Indian hedgehog (IHH) to COL2A1 was significantly reduced by differentiation in HAC-conditioned medium, and less type X collagen protein was deposited relative to type II collagen. AP activity was significantly lower (P chondrogenesis. The main inhibitory effects seen with HAC-conditioned medium were reproducible by PTHrP supplementation of unconditioned medium. HAC-derived soluble factors and direct coculture are potent means of improving chondrogenesis and suppressing the hypertrophic development of MSCs. PTHrP is an important candidate soluble factor involved in this effect.

  19. Steric Interference of Adhesion Supports In-Vitro Chondrogenesis of Mesenchymal Stem Cells on Hydrogels for Cartilage Repair.

    Science.gov (United States)

    Goldshmid, Revital; Cohen, Shlomit; Shachaf, Yonatan; Kupershmit, Ilana; Sarig-Nadir, Offra; Seliktar, Dror; Wechsler, Roni

    2015-09-28

    Recent studies suggest the presence of cell adhesion motifs found in structural proteins can inhibit chondrogenesis. In this context, the current study aims to determine if a polyethylene glycol (PEG)-modified fibrinogen matrix could support better chondrogenesis of human bone marrow mesenchymal stem cells (BM-MSC) based on steric interference of adhesion, when compared to a natural fibrin matrix. Hydrogels used as substrates for two-dimensional (2D) BM-MSC cultures under chondrogenic conditions were made from cross-linked PEG-fibrinogen (PF) and compared to thrombin-activated fibrin. Cell morphology, protein expression, DNA and sulfated proteoglycan (GAG) content were correlated to substrate properties such as stiffness and adhesiveness. Cell aggregation and chondrogenic markers, including collagen II and aggrecan, were observed on all PF substrates but not on fibrin. Shielding fibrinogen's adhesion domains and increasing stiffness of the material are likely contributing factors that cause the BM-MSCs to display a more chondrogenic phenotype. One composition of PF corresponding to GelrinC™--a product cleared in the EU for cartilage repair--was found to be optimal for supporting chondrogenic differentiation of BM-MSC while minimizing hypertrophy (collagen X). These findings suggest that semi-synthetic biomaterials based on ECM proteins can be designed to favourably affect BM-MSC towards repair processes involving chondrogenesis.

  20. Chondrogenesis and hypertrophy in response to aggregate behaviors of human mesenchymal stem cells on a dendrimer-immobilized surface.

    Science.gov (United States)

    Wongin, Sopita; Ogawa, Yuuki; Kim, Mee-Hae; Viravaidya-Pasuwat, Kwanchanok; Kino-Oka, Masahiro

    2017-08-01

    To investigate the behaviors of aggregates of human mesenchymal stem cells (hMSCs) on chondrogenesis and chondrocyte hypertrophy using spatiotemporal expression patterns of chondrogenic (type II collagen) and hypertrophic (type X collagen) markers during chondrogenesis. hMSCs were cultured on either a polystyrene surface or polyamidoamine dendrimer surface with a fifth generation (G5) dendron structure in chondrogenic medium and growth medium. At day 7, cell aggregates without stress fibers formed on the G5 surface and triggered differentiation of hMSCs toward the chondrogenic fate, as indicated by type II collagen being observed while type X collagen was undetectable. In contrast, immunostaining of hMSCs cultured on polystyrene, which exhibited abundant stress fibers and did not form aggregates, revealed no evidence of either type II and or type X collagen. At day 21, the morphological changes of the cell aggregates formed on the G5 surface were suppressed as a result of stress fiber formation. Type II collagen was observed throughout the aggregates whereas type X collagen was detected only at the basal side of the aggregates. Change of cell aggregate behaviors derived from G5 surface alone regulated chondrogenesis and hypotrophy, and this was enhanced by chondrogenic medium. Incubation of hMSCs affects the expression of type II and X collagens via effects on cell aggregate behavior and stress fiber formation.

  1. Influence of oxygen levels on chondrogenesis of porcine mesenchymal stem cells cultured in polycaprolactone scaffolds.

    Science.gov (United States)

    Rodenas-Rochina, Joaquin; Kelly, Daniel J; Gómez Ribelles, Jose Luis; Lebourg, Myriam

    2017-06-01

    Chondrogenesis of mesenchymal stem cells (MSCs) is known to be regulated by a number of environmental factors, including local oxygen levels. The hypothesis of this study is that the response of MSCs to hypoxia is dependent on the physical and chemical characteristics of the substrate used. The objective of this study was to explore how different modifications to polycaprolactone (PCL) scaffolds influenced the response of MSCs to hypoxia. PCL, PCL-hyaluronic acid (HA), and PCL-Bioglass ® (BG) scaffolds were seeded with MSCs derived from bone marrow and cultured for 35 days under normoxic or low oxygen conditions, and the resulting biochemical properties of the MSC laden construct were assessed. Low oxygen tension has a positive effect over cell proliferation and macromolecules biosynthesis. Furthermore, hypoxia enhanced the distribution of collagen and glycosaminoglycans (GAGs) deposition through the scaffold. On the other hand, MSCs displayed certain material dependent responses to hypoxia. Low oxygen tension had a positive effect on cell proliferation in BG and HA scaffolds, but only a positive effect on GAGs synthesis in PCL and HA scaffolds. In conclusion, hypoxia increased cell viability and expression of chondrogenic markers but the cell response was modulated by the type of scaffold used. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1684-1691, 2017. © 2017 Wiley Periodicals, Inc.

  2. Photocrosslinked alginate with hyaluronic acid hydrogels as vehicles for mesenchymal stem cell encapsulation and chondrogenesis.

    Science.gov (United States)

    Coates, Emily E; Riggin, Corinne N; Fisher, John P

    2013-07-01

    Ionic crosslinking of alginate via divalent cations allows for high viability of an encapsulated cell population, and is an effective biomaterial for supporting a spherical chondrocyte morphology. However, such crosslinking chemistry does not allow for injectable and stable hydrogels which are more appropriate for clinical applications. In this study, the addition of methacrylate groups to the alginate polymer chains was utilized so as to allow the free radical polymerization initiated by a photoinitiator during UV light exposure. This approach establishes covalent crosslinks between methacrylate groups instead of the ionic crosslinks formed by the calcium in unmodified alginate. Although this approach has been well described in the literature, there are currently no reports of stem cell differentiation and subsequent chondrocyte gene expression profiles in photocrosslinked alginate. In this study, we demonstrate the utility of photocrosslinked alginate hydrogels containing interpenetrating hyaluronic acid chains to support stem cell chondrogenesis. We report high cell viability and no statistical difference in metabolic activity between mesenchymal stem cells cultured in calcium crosslinked alginate and photocrosslinked alginate for up to 10 days of culture. Furthermore, chondrogenic gene markers are expressed throughout the study, and indicate robust differentiation up to the day 14 time point. At early time points, days 1 and 7, the addition of hyaluronic acid to the photocrosslinked scaffolds upregulates gene markers for both the chondrocyte and the superficial zone chondrocyte phenotype. Taken together, we show that photocrosslinked, injectable alginate shows significant potential as a delivery mechanism for cell-based cartilage repair therapies. Copyright © 2012 Wiley Periodicals, Inc.

  3. Fibrous hyaluronic acid hydrogels that direct MSC chondrogenesis through mechanical and adhesive cues.

    Science.gov (United States)

    Kim, Iris L; Khetan, Sudhir; Baker, Brendon M; Chen, Christopher S; Burdick, Jason A

    2013-07-01

    Electrospinning has recently gained much interest due to its ability to form scaffolds that mimic the nanofibrous nature of the extracellular matrix, such as the size and depth-dependent alignment of collagen fibers within hyaline cartilage. While much progress has been made in developing bulk, isotropic hydrogels for tissue engineering and understanding how the microenvironment of such scaffolds affects cell response, these effects have not been extensively studied in a nanofibrous system. Here, we show that the mechanics (through intrafiber crosslink density) and adhesivity (through RGD density) of electrospun hyaluronic acid (HA) fibers significantly affect human mesenchymal stem cell (hMSC) interactions and gene expression. Specifically, hMSC spreading, proliferation, and focal adhesion formation were dependent on RGD density, but not on the range of fiber mechanics investigated. Moreover, traction-mediated fiber displacements generally increased with more adhesive fibers. The expression of chondrogenic markers, unlike trends in cell spreading and cytoskeletal organization, was influenced by both fiber mechanics and adhesivity, in which softer fibers and lower RGD densities generally enhanced chondrogenesis. This work not only reveals concurrent effects of mechanics and adhesivity in a fibrous context, but also highlights fibrous HA hydrogels as a promising scaffold for future cartilage repair strategies. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Effect of chondrocyte-derived early extracellular matrix on chondrogenesis of placenta-derived mesenchymal stem cells.

    Science.gov (United States)

    Park, Yong-Beom; Seo, Sinji; Kim, Jin-A; Heo, Jin-Chul; Lim, Young-Cheol; Ha, Chul-Won

    2015-06-24

    The extracellular matrix (ECM) surrounding cells contains a variety of proteins that provide structural support and regulate cellular functions. Previous studies have shown that decellularized ECM isolated from tissues or cultured cells can be used to improve cell differentiation in tissue engineering applications. In this study we evaluated the effect of decellularized chondrocyte-derived ECM (CDECM) on the chondrogenesis of human placenta-derived mesenchymal stem cells (hPDMSCs) in a pellet culture system. After incubation with or without chondrocyte-derived ECM in chondrogenic medium for 1 or 3 weeks, the sizes and wet masses of the cell pellets were compared with untreated controls (hPDMSCs incubated in chondrogenic medium without chondrocyte-derived ECM). In addition, histologic analysis of the cell pellets (Safranin O and collagen type II staining) and quantitative reverse transcription-PCR analysis of chondrogenic markers (aggrecan, collagen type II, and SOX9) were carried out. Our results showed that the sizes and masses of hPDMSC pellets incubated with chondrocyte-derived ECM were significantly higher than those of untreated controls. Differentiation of hPDMSCs (both with and without chondrocyte-derived ECM) was confirmed by Safranin O and collagen type II staining. Chondrogenic marker expression and glycosaminoglycan (GAG) levels were significantly higher in hPDMSC pellets incubated with chondrocyte-derived ECM compared with untreated controls, especially in cells precultured with chondrocyte-derived ECM for 7 d. Taken together, these results demonstrate that chondrocyte-derived ECM enhances the chondrogenesis of hPDMSCs, and this effect is further increased by preculture with chondrocyte-derived ECM. This preculture method for hPDMSC chondrogenesis represents a promising approach for cartilage tissue engineering.

  5. Conditional expression of Wnt4 during chondrogenesis leads to dwarfism in mice.

    Directory of Open Access Journals (Sweden)

    Hu-Hui Lee

    Full Text Available Wnts are expressed in the forming long bones, suggesting roles in skeletogenesis. To examine the action of Wnts in skeleton formation, we developed a genetic system to conditionally express Wnt4 in chondrogenic tissues of the mouse. A mouse Wnt4 cDNA was introduced into the ubiquitously expressed Rosa26 (R26 locus by gene targeting in embryonic stem (ES cells. The expression of Wnt4 from the R26 locus was blocked by a neomycin selection cassette flanked by loxP sites (floxneo that was positioned between the Rosa26 promoter and the Wnt4 cDNA, creating the allele designated R26(floxneoWnt4. Wnt4 expression was activated during chondrogenesis using Col2a1-Cre transgenic mice that express Cre recombinase in differentiating chondrocytes. R26(floxneoWnt4; Col2a1-Cre double heterozygous mice exhibited a growth deficiency, beginning approximately 7 to 10 days after birth, that resulted in dwarfism. In addition, they also had craniofacial abnormalities, and delayed ossification of the lumbar vertebrae and pelvic bones. Histological analysis revealed a disruption in the organization of the growth plates and a delay in the onset of the primary and secondary ossification centers. Molecular studies showed that Wnt4 overexpression caused decreased proliferation and altered maturation of chondrocytes. In addition, R26(floxneoWnt4; Col2a1-Cre mice had decreased expression of vascular endothelial growth factor (VEGF. These studies demonstrate that Wnt4 overexpression leads to dwarfism in mice. The data indicate that Wnt4 levels must be regulated in chondrocytes for normal growth plate development and skeletogenesis. Decreased VEGF expression suggests that defects in vascularization may contribute to the dwarf phenotype.

  6. CD105 promotes chondrogenesis of synovium-derived mesenchymal stem cells through Smad2 signaling.

    Science.gov (United States)

    Fan, Wenshuai; Li, Jinghuan; Wang, Yiming; Pan, Jianfeng; Li, Shuo; Zhu, Liang; Guo, Changan; Yan, Zuoqin

    2016-05-27

    Mesenchymal stem cells (MSCs) are considered to be suitable for cell-based tissue regeneration. Expressions of different cell surface markers confer distinct differentiation potential to different sub-populations of MSCs. Understanding the effect of cell surface markers on MSC differentiation is essential to their targeted application in different tissues. Although CD105 positive MSCs possess strong chondrogenic capacity, the underlying mechanisms are not clear. In this study, we observed a considerable heterogeneity with respect to CD105 expression among MSCs isolated from synovium. The CD105(+) and CD105(-) synovium-derived MSCs (SMSCs) were sorted to compare their differentiation capacities and relative gene expressions. CD105(+) subpopulation had higher gene expressions of AGG, COL II and Sox9, and showed a stronger affinity for Alcian blue and immunofluorescent staining for aggrecan and collagenase II, as compared to those in CD105(-) cells. However, no significant difference was observed with respect to gene expressions of ALP, Runx2, LPL and PPARγ. CD105(+) SMSCs showed increased levels of Smad2 phosphorylation, while total Smad2 levels were similar between the two groups. There was no difference in activation of Smad1/5. These results were further confirmed by CD105-knockdown in SMSCs. Our findings suggest a stronger chondrogenic potential of CD105(+) SMSCs in comparison to that of CD105(-) SMSCs and that CD105 enhances chondrogenesis of SMSCs by regulating TGF-β/Smad2 signaling pathway, but not Smad1/5. Our study provides a better understanding of CD105 with respect to chondrogenic differentiation. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Conditional Expression of Wnt4 during Chondrogenesis Leads to Dwarfism in Mice

    Science.gov (United States)

    Lee, Hu-Hui; Behringer, Richard R.

    2007-01-01

    Wnts are expressed in the forming long bones, suggesting roles in skeletogenesis. To examine the action of Wnts in skeleton formation, we developed a genetic system to conditionally express Wnt4 in chondrogenic tissues of the mouse. A mouse Wnt4 cDNA was introduced into the ubiquitously expressed Rosa26 (R26) locus by gene targeting in embryonic stem (ES) cells. The expression of Wnt4 from the R26 locus was blocked by a neomycin selection cassette flanked by loxP sites (floxneo) that was positioned between the Rosa26 promoter and the Wnt4 cDNA, creating the allele designated R26floxneoWnt4. Wnt4 expression was activated during chondrogenesis using Col2a1-Cre transgenic mice that express Cre recombinase in differentiating chondrocytes. R26floxneoWnt4; Col2a1-Cre double heterozygous mice exhibited a growth deficiency, beginning approximately 7 to 10 days after birth, that resulted in dwarfism. In addition, they also had craniofacial abnormalities, and delayed ossification of the lumbar vertebrae and pelvic bones. Histological analysis revealed a disruption in the organization of the growth plates and a delay in the onset of the primary and secondary ossification centers. Molecular studies showed that Wnt4 overexpression caused decreased proliferation and altered maturation of chondrocytes. In addition, R26floxneoWnt4; Col2a1-Cre mice had decreased expression of vascular endothelial growth factor (VEGF). These studies demonstrate that Wnt4 overexpression leads to dwarfism in mice. The data indicate that Wnt4 levels must be regulated in chondrocytes for normal growth plate development and skeletogenesis. Decreased VEGF expression suggests that defects in vascularization may contribute to the dwarf phenotype. PMID:17505543

  8. The Influence of IL-10 and TNFα on Chondrogenesis of Human Mesenchymal Stromal Cells in Three-Dimensional Cultures

    Directory of Open Access Journals (Sweden)

    Michal Jagielski

    2014-09-01

    Full Text Available Chondrogenic differentiated mesenchymal stromal cells (MSCs are a promising cell source for articular cartilage repair. This study was undertaken to determine the effectiveness of two three-dimensional (3D culture systems for chondrogenic MSC differentiation in comparison to primary chondrocytes and to assess the effect of Interleukin (IL-10 and Tumor Necrosis Factor (TNFα on chondrogenesis by MSCs in 3D high-density (H-D culture. MSCs were isolated from femur spongiosa, characterized using a set of typical markers and introduced in scaffold-free H-D cultures or non-woven polyglycolic acid (PGA scaffolds for chondrogenic differentiation. H-D cultures were stimulated with recombinant IL-10, TNFα, TNFα + IL-10 or remained untreated. Gene and protein expression of type II collagen, aggrecan, sox9 and TNFα were examined. MSCs expressed typical cell surface markers and revealed multipotency. Chondrogenic differentiated cells expressed cartilage-specific markers in both culture systems but to a lower extent when compared with articular chondrocytes. Chondrogenesis was more pronounced in PGA compared with H-D culture. IL-10 and/or TNFα did not impair the chondrogenic differentiation of MSCs. Moreover, in most of the investigated samples, despite not reaching significance level, IL-10 had a stimulatory effect on the type II collagen, aggrecan and TNFα expression when compared with the respective controls.

  9. The influence of IL-10 and TNFα on chondrogenesis of human mesenchymal stromal cells in three-dimensional cultures.

    Science.gov (United States)

    Jagielski, Michal; Wolf, Johannes; Marzahn, Ulrike; Völker, Anna; Lemke, Marion; Meier, Carola; Ertel, Wolfgang; Godkin, Owen; Arens, Stephan; Schulze-Tanzil, Gundula

    2014-09-09

    Chondrogenic differentiated mesenchymal stromal cells (MSCs) are a promising cell source for articular cartilage repair. This study was undertaken to determine the effectiveness of two three-dimensional (3D) culture systems for chondrogenic MSC differentiation in comparison to primary chondrocytes and to assess the effect of Interleukin (IL)-10 and Tumor Necrosis Factor (TNF)α on chondrogenesis by MSCs in 3D high-density (H-D) culture. MSCs were isolated from femur spongiosa, characterized using a set of typical markers and introduced in scaffold-free H-D cultures or non-woven polyglycolic acid (PGA) scaffolds for chondrogenic differentiation. H-D cultures were stimulated with recombinant IL-10, TNFα, TNFα + IL-10 or remained untreated. Gene and protein expression of type II collagen, aggrecan, sox9 and TNFα were examined. MSCs expressed typical cell surface markers and revealed multipotency. Chondrogenic differentiated cells expressed cartilage-specific markers in both culture systems but to a lower extent when compared with articular chondrocytes. Chondrogenesis was more pronounced in PGA compared with H-D culture. IL-10 and/or TNFα did not impair the chondrogenic differentiation of MSCs. Moreover, in most of the investigated samples, despite not reaching significance level, IL-10 had a stimulatory effect on the type II collagen, aggrecan and TNFα expression when compared with the respective controls.

  10. The osmolyte type affects cartilage associated pathologic marker expression during in vitro mesenchymal stem cell chondrogenesis under hypertonic conditions.

    Science.gov (United States)

    Ahmadyan, Sorour; Kabiri, Mahboubeh; Tasharofi, Noushin; Hosseinzadeh, Simzar; Kehtari, Mousa; Hajari Zadeh, Athena; Soleimani, Masoud; Farazmand, Ali; Hanaee-Ahvaz, Hana

    2018-02-28

    Stem cells' fate during in vitro differentiation is influenced by biophysicochemical cues. Osmotic stress has proved to enhance chondrocyte marker expression, however its potent negative impacts had never been surveyed. We questioned whether specific osmotic conditions, regarding the osmolyte agent, could benefit chondrogenesis while dampening undesired concomitant hypertrophy and inflammatory responses. To examine the potential side effects of hypertonicity, we assessed cell proliferation as well as chondrogenic and hypertrophic marker expression of human Adipose Derived-MSC after a two week induction in chondrogenic media with either NaCl or Sorbitol, as the osmolyte agent to reach a +100 mOsm hypertonic condition. Calcium deposition and TNF-α secretion as markers associated with hypertrophy and inflammation were then assayed. While both hyperosmotic conditions upregulated chondrogenic markers, sorbitol had a nearly three times higher chondro-promotive effect and a lesser hypertrophic effect compared to NaCl. Also, a significantly lesser calcium deposition was observed in sorbitol hypertonic group. NaCl showed an anti-proinflammatory effect while sorbitol had no effect on inflammatory markers. The ossification potential and cartilage associated pathologic markers were affected differentially by the type of the osmolyte. Thus, a vigilant application of the osmotic agent is inevitable in order to avoid or reduce undesired hypertrophic and inflammatory phenotype acquisition by MSC during chondrogenic differentiation. Our findings are a step towards developing a more reliable chondrogenic regimen using external hypertonic cues for MSC chondrogenesis with potential applications in chondral lesions cell therapy.

  11. Silk fibroin/gelatin–chondroitin sulfate–hyaluronic acid effectively enhances in vitro chondrogenesis of bone marrow mesenchymal stem cells

    International Nuclear Information System (INIS)

    Sawatjui, Nopporn; Damrongrungruang, Teerasak; Leeanansaksiri, Wilairat; Jearanaikoon, Patcharee; Hongeng, Suradej; Limpaiboon, Temduang

    2015-01-01

    Tissue engineering is becoming promising for cartilage repair due to the limited self-repair capacity of cartilage tissue. We previously fabricated and characterized a three-dimensional silk fibroin/gelatin–chondroitin sulfate–hyaluronic acid (SF–GCH) scaffold and showed that it could promote proliferation of human bone marrow mesenchymal stem cells (BM-MSCs). This study aimed to evaluate its biological performance as a new biomimetic material for chondrogenic induction of BM-MSCs in comparison to an SF scaffold and conventional pellet culture. We found that the SF–GCH scaffold significantly enhanced the proliferation and chondrogenic differentiation of BM-MSCs compared to the SF scaffold and pellet culture in which the production of sulfated glycoaminoglycan was increased in concordance with the up-regulation of chondrogenic-specific gene markers. Our findings indicate the significant role of SF–GCH by providing a supportive structure and the mimetic cartilage environment for chondrogenesis which enables cartilage regeneration. Thus, our fabricated SF–GCH scaffold may serve as a potential biomimetic material for cartilage tissue engineering. - Highlights: • SF–GCH scaffold enhances proliferation and chondrogenic differentiation of BM-MSCs. • SF–GCH acts as a supportive and biomimetic material for BM-MSC chondrogenesis. • SF–GCH is a potential biomimetic scaffold suitable for cartilage tissue engineering

  12. Silk fibroin/gelatin–chondroitin sulfate–hyaluronic acid effectively enhances in vitro chondrogenesis of bone marrow mesenchymal stem cells

    Energy Technology Data Exchange (ETDEWEB)

    Sawatjui, Nopporn [Biomedical Sciences, Graduate School, Khon Kaen University, Khon Kaen 40002 (Thailand); Centre for Research and Development of Medical Diagnostic Laboratories, Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen 40002 (Thailand); Damrongrungruang, Teerasak [Department of Oral Diagnosis, Faculty of Dentistry, Khon Kaen University, Khon Kaen 40002 (Thailand); Leeanansaksiri, Wilairat [Stem Cell Therapy and Transplantation Research Group, Suranaree University of Technology, Nakhon Ratchasima 30000 (Thailand); School of Microbiology, Suranaree University of Technology, Nakhon Ratchasima 30000 (Thailand); Jearanaikoon, Patcharee [Centre for Research and Development of Medical Diagnostic Laboratories, Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen 40002 (Thailand); Hongeng, Suradej [Department of Pediatrics, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok 10400 (Thailand); Limpaiboon, Temduang, E-mail: temduang@kku.ac.th [Centre for Research and Development of Medical Diagnostic Laboratories, Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen 40002 (Thailand)

    2015-07-01

    Tissue engineering is becoming promising for cartilage repair due to the limited self-repair capacity of cartilage tissue. We previously fabricated and characterized a three-dimensional silk fibroin/gelatin–chondroitin sulfate–hyaluronic acid (SF–GCH) scaffold and showed that it could promote proliferation of human bone marrow mesenchymal stem cells (BM-MSCs). This study aimed to evaluate its biological performance as a new biomimetic material for chondrogenic induction of BM-MSCs in comparison to an SF scaffold and conventional pellet culture. We found that the SF–GCH scaffold significantly enhanced the proliferation and chondrogenic differentiation of BM-MSCs compared to the SF scaffold and pellet culture in which the production of sulfated glycoaminoglycan was increased in concordance with the up-regulation of chondrogenic-specific gene markers. Our findings indicate the significant role of SF–GCH by providing a supportive structure and the mimetic cartilage environment for chondrogenesis which enables cartilage regeneration. Thus, our fabricated SF–GCH scaffold may serve as a potential biomimetic material for cartilage tissue engineering. - Highlights: • SF–GCH scaffold enhances proliferation and chondrogenic differentiation of BM-MSCs. • SF–GCH acts as a supportive and biomimetic material for BM-MSC chondrogenesis. • SF–GCH is a potential biomimetic scaffold suitable for cartilage tissue engineering.

  13. New PLGA-P188-PLGA matrix enhances TGF-β3 release from pharmacologically active microcarriers and promotes chondrogenesis of mesenchymal stem cells.

    Science.gov (United States)

    Morille, Marie; Van-Thanh, Tran; Garric, Xavier; Cayon, Jérôme; Coudane, Jean; Noël, Danièle; Venier-Julienne, Marie-Claire; Montero-Menei, Claudia N

    2013-08-28

    The use of injectable scaffolding materials for in vivo tissue regeneration has raised great interest in various clinical applications because it allows cell implantation through minimally invasive surgical procedures. In case of cartilage repair, a tissue engineered construct should provide a support for the cell and allow sustained in situ delivery of bioactive factors capable of inducing cell differentiation into chondrocytes. Pharmacologically active microcarriers (PAMs), made of biodegradable poly(d,l-lactide-co-glycolide acid) (PLGA), are a unique system, which combines these properties in an adaptable and simple microdevice. However, a limitation of such scaffold is low and incomplete protein release that occurs using the hydrophobic PLGA based microspheres. To circumvent this problem, we developed a novel formulation of polymeric PAMs containing a P188 poloxamer, which protects the protein from denaturation and may positively affect chondrogenesis. This poloxamer was added as a free additive for protein complexation and as a component of the scaffold covalently linked to PLGA. This procedure allows getting a more hydrophilic scaffold but also retaining the protective polymer inside the microcarriers during their degradation. The novel PLGA-P188-PLGA PAMs presenting a fibronectin-covered surface allowed enhanced MSC survival and proliferation. When engineered with TGFβ3, they allowed the sustained release of 70% of the incorporated TGF-β3 over time. Importantly, they exerted superior chondrogenic differentiation potential compared to previous FN-PAM-PLGA-TGF-β3, as shown by an increased expression of specific cartilage markers such as cartilage type II, aggrecan and COMP. Therefore, this microdevice represents an efficient easy-to-handle and injectable tool for cartilage repair. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. Osteogenesis and chondrogenesis of biomimetic integrated porous PVA/gel/V-n-HA/pa6 scaffolds and BMSCs construct in repair of articular osteochondral defect.

    Science.gov (United States)

    Li, Xiang; Li, Yubao; Zuo, Yi; Qu, Dan; Liu, Yiming; Chen, Tao; Jiang, Nan; Li, Hui; Li, Jihua

    2015-10-01

    A novel bi-layered osteochondral scaffold, including of PVA/Gel/V layer for the cartilage and n-HA/PA6 layer for the subchondral bone, has been proposed to evaluate the potential of the engineered of osteochondral grafts in repairing articular osteochondral defects in rabbits. The two different layers of the scaffolds were seeded with allogenic bone marrow-derived stem cells (BMSCs), which were chondrogenically and osteogenically induced respectively. The critical-size osteochondral defects were created in the knees of adult rabbits. The defects were treated with cell-bi-layered constructs (Group A), bi-layered constructs (Group B) and untreated group C as control group. The adhesion, proliferation and differentiation of BMSCs were demonstrated by immunohistochemical staining and scanning electron microscopy (SEM) in vitro. Cell survival was tracked via fluorescent labeling in vivo. Overall, the porous PVA/Gel/V-n-HA/PA6 scaffold was compatible and had no negative effects on the BMSCs in vitro culture. The cell-bi-layered scaffolds showed superior repair results as compared to the control group using gross examination and histological assessment. With BMSCs implantation, the two different layers of the composite biomimetic scaffolds provided a suitable environment for cells to form respective tissue. Simultaneously, the RT-PCR results confirmed the expression of specific extracellular matrix (ECM) markers for cartilaginous or osteoid tissue. This investigation showed that the porous PVA/Gel/V-n-HA/PA6 scaffold is a potential matrix for treatment of osteochondral defects, and the method of using chondrogenically and osteogenically differentiated BMSCs as seed cells on each layer might be a promising strategy in repair of articular osteochondral defect due to enhanced chondrogenesis and osteogenesis. © 2015 Wiley Periodicals, Inc.

  15. Molecular profile and cellular characterization of human bone marrow mesenchymal stem cells: donor influence on chondrogenesis.

    Science.gov (United States)

    Cicione, Claudia; Díaz-Prado, Silvia; Muiños-López, Emma; Hermida-Gómez, Tamara; Blanco, Francisco J

    2010-01-01

    The use of autologous or allogenic stem cells has recently been suggested as an alternative therapeutic approach for treatment of cartilage defects. Bone marrow mesenchymal stem cells (BM-MSCs) are well-characterized multipotent cells that can differentiate into different cell types. Understanding the potential of these cells and the molecular mechanisms underlying their differentiation should lead to innovative protocols for clinical applications. The aim of this study was to evaluate the usefulness of surface antigen selection of BM-MSCs and to understand the mechanisms underlying their differentiation. MSCs were isolated from BM stroma and expanded. CD105+ subpopulation was isolated using a magnetic separator. We compared culture-expanded selected cells with non-selected cells. We analyzed the phenotypic profiles, the expression of the stem cell marker genes Nanog, Oct3/4, and Sox2 and the multi-lineage differentiation potential (adipogenic, osteogenic, and chondrogenic). The multi-lineage differentiation was confirmed using histochemistry, immunohistochemistry and/or real-time polymerase chain reaction (qPCR) techniques. The selected and non-selected cells displayed similar phenotypes and multi-lineage differentiation potentials. Analyzing each cell source individually, we could divide the six donors into two groups: one with a high percentage of CD29 (β1-integrin) expression (HL); one with a low percentage of CD29 (LL). These two groups had different chondrogenic capacities and different expression levels of the stem cell marker genes. This study showed that phenotypic profiles of donors were related to the chondrogenic potential of human BM-MSCs. The chondrogenic potential of donors was related to CD29 expression levels. The high expression of CD29 antigen seemed necessary for chondrogenic differentiation. Further investigation into the mechanisms responsible for these differences in BM-MSCs chondrogenesis is therefore warranted. Understanding the mechanisms

  16. Fibronectin- and collagen-mimetic ligands regulate bone marrow stromal cell chondrogenesis in three-dimensional hydrogels

    Directory of Open Access Journals (Sweden)

    JT Connelly

    2011-09-01

    Full Text Available Modification of tissue engineering scaffolds with bioactive molecules is a potential strategy for modulating cell behavior and guiding tissue regeneration. While adhesion to RGD peptides has been shown to inhibit in vitro chondrogenesis, the effects of extracellular matrix (ECM-mimetic ligands with complex secondary and tertiary structures are unknown. This study aimed to determine whether collagen- and fibronectin-mimetic ligands would retain biologic functionality in three-dimensional (3D hydrogels, whether different ECM-mimetic ligands differentially influence in vitro chondrogenesis, and if effects of ligands on differentiation depend on soluble biochemical stimuli. A linear RGD peptide, a recombinant fibronectin fragment containing the seven to ten Type III repeats (FnIII7-10 and a triple helical, collagen mimetic peptide with the GFOGER motif were covalently coupled to agarose gels using the sulfo-SANPAH crosslinker, and bone marrow stromal cells (BMSCs were cultured within the 3D hydrogels. The ligands retained biologic functionality within the agarose gels and promoted density-dependent BMSC spreading. Interactions with all adhesive ligands inhibited stimulation by chondrogenic factors of collagen Type II and aggrecan mRNA levels and deposition of sulfated glycosaminoglycans. In medium containing fetal bovine serum, interactions with the GFOGER peptide enhanced mRNA expression of the osteogenic gene osteocalcin whereas FnIII7-10 inhibited osteocalcin expression. In conclusion, modification of agarose hydrogels with ECM-mimetic ligands can influence the differentiation of BMSCs in a manner that depends strongly on the presence and nature of soluble biochemical stimuli.

  17. Three-dimensional scaffold-free fusion culture: the way to enhance chondrogenesis of in vitro propagated human articular chondrocytes

    Directory of Open Access Journals (Sweden)

    M. Lehmann

    2013-11-01

    Full Text Available Cartilage regeneration based on isolated and culture-expanded chondrocytes has been studied in various in vitro models, but the quality varies with respect to the morphology and the physiology of the synthesized tissues. The aim of our study was to promote in vitro chondrogenesis of human articular chondrocytes using a novel three-dimensional (3-D cultivation system in combination with the chondrogenic differentiation factors transforming growth factor beta 2 (TGF-b2 and L-ascorbic acid. Articular chondrocytes isolated from six elderly patients were expanded in monolayer culture. A single-cell suspension of the dedifferentiated chondrocytes was then added to agar-coated dishes without using any scaffold material, in the presence, or absence of TGF-b2 and/or L-ascorbic acid. Three-dimensional cartilage-like constructs, called single spheroids, and microtissues consisting of several spheroids fused together, named as fusions, were formed. Generated tissues were mainly characterized using histological and immunohistochemical techniques. The morphology of the in vitro tissues shared some similarities to native hyaline cartilage in regard to differentiated S100-positive chondrocytes within a cartilaginous matrix, with strong collagen type II expression and increased synthesis of proteoglycans. Finally, our innovative scaffold-free fusion culture technique supported enhanced chondrogenesis of human articular chondrocytes in vitro. These 3-D hyaline cartilage-like microtissues will be useful for in vitro studies of cartilage differentiation and regeneration, enabling optimization of functional tissue engineering and possibly contributing to the development of new approaches to treat traumatic cartilage defects or osteoarthritis.

  18. Controlled chondrogenesis from adipose-derived stem cells by recombinant transforming growth factor-β3 fusion protein in peptide scaffolds.

    Science.gov (United States)

    Zheng, Dong; Dan, Yang; Yang, Shu-hua; Liu, Guo-hui; Shao, Zeng-wu; Yang, Cao; Xiao, Bao-jun; Liu, Xiangmei; Wu, Shuilin; Zhang, Tainjin; Chu, Paul K

    2015-01-01

    Adipose-derived stem cells (ADSCs) are promising for cartilage repair due to their easy accessibility and chondrogenic potential. Although chondrogenesis of transforming growth factor-β (TGF-β) mediated mesenchymal stem cells (MSCs) is well established in vitro, clinical tissue engineering requires effective and controlled delivery of TGF-β in vivo. In this work, a self-assembled peptide scaffold was employed to construct cartilages in vivo through the chondrogenesis from ADSCs controlled by recombinant fusion protein LAP-MMP-mTGF-β3 that was transfected by lentiviral vectors. During this course, the addition of matrix metalloproteinases (MMPs) can trigger the release of mTGF-β3 from the recombinant fusion protein of LAP-MMP-mTGF-β3 in the combined scaffolds, thus stimulating the differentiation of ADSCs into chondrogenesis. The specific expression of cartilage genes was analyzed by real-time polymerase chain reaction and Western blot. The expression of chondrocytic markers was obviously upregulated to a higher level compared to the one by commonly used TGF-β3 alone. After 3 weeks of in vitro culturing, the hybrids with differentiated chondrogenesis were then injected subcutaneously into nude mice and retrieved after 4 weeks of culturing in vivo. Histological analysis also confirmed that the recombinant fusion protein was more effective for the formation of cartilage matrix than the cases either with TGF-β3 alone or without LAP-MMP-mTGF-β3 (P<0.05). This study demonstrates that controlled local delivery of the LAP-MMP-mTGF-β3 constructs can accelerate differentiation of ADSCs into the cartilage in vivo, which indicates the great potential of this hybrid in rapid therapy of osteoarthritis. Copyright © 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  19. A 3D Porous Gelatin-Alginate-Based-IPN Acts as an Efficient Promoter of Chondrogenesis from Human Adipose-Derived Stem Cells

    OpenAIRE

    Dinescu, Sorina; Galateanu, Bianca; Radu, Eugen; Hermenean, Anca; Lungu, Adriana; Stancu, Izabela Cristina; Jianu, Dana; Tumbar, Tudorita; Costache, Marieta

    2015-01-01

    Cartilage has limited regeneration potential. Thus, there is an imperative need to develop new strategies for cartilage tissue engineering (CTE) amenable for clinical use. Recent CTE approaches rely on optimal cell-scaffold interactions, which require a great deal of optimization. In this study we attempt to build a novel gelatin- (G-) alginate- (A-) polyacrylamide (PAA) 3D interpenetrating network (IPN) with superior performance in promoting chondrogenesis from human adipose-derived stem cel...

  20. Long-term dynamic loading improves the mechanical properties of chondrogenic mesenchymal stem cell-laden hydrogel

    Directory of Open Access Journals (Sweden)

    AH Huang

    2010-02-01

    Full Text Available Mesenchymal stem cells (MSCs are an attractive cell source for cartilage tissue engineering given their ability to undergo chondrogenesis in 3D culture systems. Mechanical forces play an important role in regulating both cartilage development and MSC chondrogenic gene expression, however, mechanical stimulation has yet to enhance the mechanical properties of engineered constructs. In this study, we applied long-term dynamic compression to MSC-seeded constructs and assessed whether varying pre-culture duration, loading regimens and inclusion of TGF-beta3 during loading would influence functional outcomes and these phenotypic transitions. Loading initiated before chondrogenesis decreased functional maturation, although chondrogenic gene expression increased. In contrast, loading initiated after chondrogenesis and matrix elaboration further improved the mechanical properties of MSC-based constructs, but only when TGF-beta3 levels were maintained and under specific loading parameters. Although matrix quantity was not affected by dynamic compression, matrix distribution, assessed histologically and by FT-IRIS analysis, was significantly improved on the micro- (pericellular and macro- (construct expanse scales. Further, whole genome expression profiling revealed marked shifts in the molecular topography with dynamic loading. These results demonstrate, for the first time, that dynamic compressive loading initiated after a sufficient period of chondro-induction and with sustained TGF-beta exposure enhances matrix distribution and the mechanical properties of MSC-seeded constructs.

  1. Fibrin and poly(lactic-co-glycolic acid) hybrid scaffold promotes early chondrogenesis of articular chondrocytes: an in vitro study.

    Science.gov (United States)

    Sha'ban, Munirah; Kim, Soon Hee; Idrus, Ruszymah Bh; Khang, Gilson

    2008-04-25

    Synthetic- and naturally derived- biodegradable polymers have been widely used to construct scaffolds for cartilage tissue engineering. Poly(lactic-co-glycolic acid) (PLGA) are bioresorbable and biocompatible, rendering them as a promising tool for clinical application. To minimize cells lost during the seeding procedure, we used the natural polymer fibrin to immobilize cells and to provide homogenous cells distribution in PLGA scaffolds. We evaluated in vitro chondrogenesis of rabbit articular chondrocytes in PLGA scaffolds using fibrin as cell transplantation matrix. PLGA scaffolds were soaked in chondrocytes-fibrin suspension (1 x 10(6) cells/scaffold) and polymerized by dropping thrombin-calcium chloride (CaCl2) solution. PLGA-seeded chondrocytes was used as control. All constructs were cultured for a maximum of 21 days. Cell proliferation activity was measured at 1, 3, 7, 14 and 21 days in vitro using 3-(4,5-dimethylthiazole-2-yl)-2-, 5-diphenyltetrazolium-bromide (MTT) assay. Morphological observation, histology, immunohistochemistry (IHC), gene expression and sulphated-glycosaminoglycan (sGAG) analyses were performed at each time point of 1, 2 and 3 weeks to elucidate in vitro cartilage development and deposition of cartilage-specific extracellular matrix (ECM). Cell proliferation activity was gradually increased from day-1 until day-14 and declined by day-21. A significant cartilaginous tissue formation was detected as early as 2-week in fibrin/PLGA hybrid construct as confirmed by the presence of cartilage-isolated cells and lacunae embedded within basophilic ECM. Cartilage formation was remarkably evidenced after 3 weeks. Presence of cartilage-specific proteoglycan and glycosaminoglycan (GAG) in fibrin/PLGA hybrid constructs were confirmed by positive Safranin O and Alcian Blue staining. Collagen type II exhibited intense immunopositivity at the pericellular matrix. Chondrogenic properties were further demonstrated by the expression of genes encoded for

  2. Fibrin and poly(lactic-co-glycolic acid hybrid scaffold promotes early chondrogenesis of articular chondrocytes: an in vitro study

    Directory of Open Access Journals (Sweden)

    Idrus Ruszymah BH

    2008-04-01

    Full Text Available Abstract Background Synthetic- and naturally derived- biodegradable polymers have been widely used to construct scaffolds for cartilage tissue engineering. Poly(lactic-co-glycolic acid (PLGA are bioresorbable and biocompatible, rendering them as a promising tool for clinical application. To minimize cells lost during the seeding procedure, we used the natural polymer fibrin to immobilize cells and to provide homogenous cells distribution in PLGA scaffolds. We evaluated in vitro chondrogenesis of rabbit articular chondrocytes in PLGA scaffolds using fibrin as cell transplantation matrix. Methods PLGA scaffolds were soaked in chondrocytes-fibrin suspension (1 × 106cells/scaffold and polymerized by dropping thrombin-calcium chloride (CaCl2 solution. PLGA-seeded chondrocytes was used as control. All constructs were cultured for a maximum of 21 days. Cell proliferation activity was measured at 1, 3, 7, 14 and 21 days in vitro using 3-(4,5-dimethylthiazole-2-yl-2-, 5-diphenyltetrazolium-bromide (MTT assay. Morphological observation, histology, immunohistochemistry (IHC, gene expression and sulphated-glycosaminoglycan (sGAG analyses were performed at each time point of 1, 2 and 3 weeks to elucidate in vitro cartilage development and deposition of cartilage-specific extracellular matrix (ECM. Results Cell proliferation activity was gradually increased from day-1 until day-14 and declined by day-21. A significant cartilaginous tissue formation was detected as early as 2-week in fibrin/PLGA hybrid construct as confirmed by the presence of cartilage-isolated cells and lacunae embedded within basophilic ECM. Cartilage formation was remarkably evidenced after 3 weeks. Presence of cartilage-specific proteoglycan and glycosaminoglycan (GAG in fibrin/PLGA hybrid constructs were confirmed by positive Safranin O and Alcian Blue staining. Collagen type II exhibited intense immunopositivity at the pericellular matrix. Chondrogenic properties were further

  3. Mechanical loading stimulates chondrogenesis via the PKA/CREB-Sox9 and PP2A pathways in chicken micromass cultures.

    Science.gov (United States)

    Juhász, Tamás; Matta, Csaba; Somogyi, Csilla; Katona, Éva; Takács, Roland; Soha, Rudolf Ferenc; Szabó, István A; Cserháti, Csaba; Sződy, Róbert; Karácsonyi, Zoltán; Bakó, Eva; Gergely, Pál; Zákány, Róza

    2014-03-01

    Biomechanical stimuli play important roles in the formation of articular cartilage during early foetal life, and optimal mechanical load is a crucial regulatory factor of adult chondrocyte metabolism and function. In this study, we undertook to analyse mechanotransduction pathways during in vitro chondrogenesis. Chondroprogenitor cells isolated from limb buds of 4-day-old chicken embryos were cultivated as high density cell cultures for 6 days. Mechanical stimulation was carried out by a self-designed bioreactor that exerted uniaxial intermittent cyclic load transmitted by the culture medium as hydrostatic pressure and fluid shear to differentiating cells. The loading scheme (0.05 Hz, 600 Pa; for 30 min) was applied on culturing days 2 and 3, when final commitment and differentiation of chondroprogenitor cells occurred in this model. The applied mechanical load significantly augmented cartilage matrix production and elevated mRNA expression of several cartilage matrix constituents, including collagen type II and aggrecan core protein, as well as matrix-producing hyaluronan synthases through enhanced expression, phosphorylation and nuclear signals of the main chondrogenic transcription factor Sox9. Along with increased cAMP levels, a significantly enhanced protein kinase A (PKA) activity was also detected and CREB, the archetypal downstream transcription factor of PKA signalling, exhibited elevated phosphorylation levels and stronger nuclear signals in response to mechanical stimuli. All the above effects were diminished by the PKA-inhibitor H89. Inhibition of the PKA-independent cAMP-mediators Epac1 and Epac2 with HJC0197 resulted in enhanced cartilage formation, which was additive to that of the mechanical stimulation, implying that the chondrogenesis-promoting effect of mechanical load was independent of Epac. At the same time, PP2A activity was reduced following mechanical load and treatments with the PP2A-inhibitor okadaic acid were able to mimic the effects of

  4. Cellular anomalies underlying retinoid-induced phocomelia.

    Science.gov (United States)

    Zhou, Jian; Kochhar, Devendra M

    2004-11-01

    The question of how alterations in cell behavior produced by retinoic acid (RA) influenced the development of skeletogenic mesenchyme of the limb bud was examined in this study. Our established model was employed, which involves treatment of pregnant mice with a teratogenic dose of RA (100 mg/kg) on 11 days postcoitum (dpc) resulting in a severe truncation of all long bones of the forelimbs in virtually every exposed fetus. It is shown that RA, administered at a stage to induce phocomelia in virtually all exposed embryos, resulted in immediate appearance of enhanced cell death within the mesenchyme in the central core of the limb bud, an area destined for chondrogenesis. The central core mesenchyme, which in the untreated limb buds experiences a sharp decline in cell proliferation heralding the onset of chondrogenesis, demonstrated a reversal of the process; this mesenchyme maintained a higher rate of cell proliferation upon RA exposure. These events resulted in a truncation and disorganization of the chondrogenic anlage, more pronounced in zeugopodal mesenchyme than in the autopod. We conclude that an inhibition of chondrogenesis was secondary to a disruption in cellular behavior caused by RA, a likely consequence of misregulation in the growth factor signaling cascade.

  5. Silk fibroin/gelatin-chondroitin sulfate-hyaluronic acid effectively enhances in vitro chondrogenesis of bone marrow mesenchymal stem cells.

    Science.gov (United States)

    Sawatjui, Nopporn; Damrongrungruang, Teerasak; Leeanansaksiri, Wilairat; Jearanaikoon, Patcharee; Hongeng, Suradej; Limpaiboon, Temduang

    2015-01-01

    Tissue engineering is becoming promising for cartilage repair due to the limited self-repair capacity of cartilage tissue. We previously fabricated and characterized a three-dimensional silk fibroin/gelatin-chondroitin sulfate-hyaluronic acid (SF-GCH) scaffold and showed that it could promote proliferation of human bone marrow mesenchymal stem cells (BM-MSCs). This study aimed to evaluate its biological performance as a new biomimetic material for chondrogenic induction of BM-MSCs in comparison to an SF scaffold and conventional pellet culture. We found that the SF-GCH scaffold significantly enhanced the proliferation and chondrogenic differentiation of BM-MSCs compared to the SF scaffold and pellet culture in which the production of sulfated glycoaminoglycan was increased in concordance with the up-regulation of chondrogenic-specific gene markers. Our findings indicate the significant role of SF-GCH by providing a supportive structure and the mimetic cartilage environment for chondrogenesis which enables cartilage regeneration. Thus, our fabricated SF-GCH scaffold may serve as a potential biomimetic material for cartilage tissue engineering. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Initial boost release of transforming growth factor-β3 and chondrogenesis by freeze-dried bioactive polymer scaffolds.

    Science.gov (United States)

    Krüger, Jan Philipp; Machens, Isabel; Lahner, Matthias; Endres, Michaela; Kaps, Christian

    2014-12-01

    In cartilage regeneration, bio-activated implants are used in stem and progenitor cell-based microfracture cartilage repair procedures. Our aim was to analyze the chondrogenic potential of freeze-dried resorbable polymer-based polyglycolic acid (PGA) scaffolds bio-activated with transforming growth factor-β3 (TGFB3) on human subchondral mesenchymal progenitor cells known from microfracture. Progenitor cells derived from femur heads were cultured in the presence of freeze-dried TGFB3 in high-density pellet culture and in freeze-dried TGFB3-PGA scaffolds for chondrogenic differentiation. Progenitor cell cultures in PGA scaffolds as well as pellet cultures with and without continuous application of TGFB3 served as controls. Release studies showed that freeze-dried TGFB3-PGA scaffolds facilitate a rapid, initial boost-like release of 71.5% of TGFB3 in the first 10 h. Gene expression analysis and histology showed induction of typical chondrogenic markers like type II collagen and formation of cartilaginous tissue in TGFB3-PGA scaffolds seeded with subchondral progenitor cells and in pellet cultures stimulated with freeze-dried TGFB3. Chondrogenic differentiation in freeze-dried TGFB3-PGA scaffolds was comparable to cultures receiving TGFB3 continuously, while non-stimulated controls did not show chondrogenesis during prolonged culture for 14 days. These results suggest that bio-activated, freeze-dried TGFB3-PGA scaffolds have chondrogenic potential and are a promising tool for stem cell-mediated cartilage regeneration.

  7. Characterization of progenitor cells derived from torn human rotator cuff tendons by gene expression patterns of chondrogenesis, osteogenesis, and adipogenesis.

    Science.gov (United States)

    Nagura, Issei; Kokubu, Takeshi; Mifune, Yutaka; Inui, Atsuyuki; Takase, Fumiaki; Ueda, Yasuhiro; Kataoka, Takeshi; Kurosaka, Masahiro

    2016-03-31

    It is important to regenerate the tendon-to-bone interface after rotator cuff repair to prevent re-tears. The cells from torn human rotator cuff were targeted, and their capacity for multilineage differentiation was investigated. The edges of the rotator cuff were harvested during arthroscopic rotator cuff repair from nine patients, minced into pieces, and cultured on dishes. Adherent cells were cultured, phenotypically characterized. Then expandability, differentiation potential and gene expression were analyzed. Flow cytometry revealed that the mesenchymal stem cells (MSC)-related markers CD29, CD44, CD105, and CD166 were positive. However, CD14, CD34, and CD45 were negative. On RT-PCR analyses, the cells showed osteogenic, adipogenic, and chondrogenic potential after 3 weeks of culture under the respective differentiation conditions. In addition, SOX9, type II collagen, and type X collagen expression patterns during chondrogenesis were similar to those of endochondral ossification at the enthesis. The cells derived from torn human rotator cuff are multipotent mesenchymal stem cells with the ability to undergo multilineage differentiation, suggesting that MSCs form this tissue could be regenerative capacity for potential self-repair.

  8. Sulfoxide stimulation of chondrogenesis in limb mesenchyme is accompanied by an increase in type II collagen enhancer activity

    International Nuclear Information System (INIS)

    Horton, W.E. Jr.; Higginbotham, J.D.

    1991-01-01

    We have utilized a modification of the limb bud mesenchyme micromass culture system to screen compounds that might stimulate chondrogenesis. Two compounds in the sulfoxide family (methylphenylsulfoxide and p-chlorophenyl methyl sulfoxide) were stimulatory at 10(-2) M and 10(-3) M, respectively; whereas other sulfoxides and organic solvents were not active at these concentrations. In addition, specific growth factors (basic FGF, IGF-I, IGF-II) were not chondroinductive at concentrations that are active in other cell systems. Both sulfoxide compounds stimulated cartilage nodule formation, [ 35 S]sulfate incorporation, and activity of the regulatory sequences of the collagen II gene. In contrast, transforming growth factor beta-1 (10 ng/ml) stimulated sulfate incorporation but produced only a diffuse deposition of cartilage matrix and reduced the ability of the cells to utilize the regulatory sequences of the collagen II gene. The sulfoxides appear to promote the differentiation of limb bud cells to chondrocytes and thus exhibit chondroinductive activity

  9. Implantation of Octacalcium Phosphate Stimulates both Chondrogenesis and Osteogenesis in the Tibia, but Only Osteogenesis in the Rat Mandible

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    F. Sargolzaei Aval

    2006-09-01

    Full Text Available Statement of problem: It is not known whether endochondral and intramembranous bones have distinct biological characteristics. Octacalcium Phosphate (OCP, a hydroxyapatite precursor, has been reported to stimulate bone formation after being implanted in parietal bone defects of rats.Purpose: The present study was designed to investigate the response of endochondral and intramembranous bones to OCP implantation and to compare their biological characteristicsMaterials and Methods: Full-thickness standardized trephine defects were made in rat tibiae and mandibles and synthetic OCP was implanted into the defects. The biologic response was examined histologically to identify bone and cartilage formation.Results: Both chondrogenesis and osteogenesis were initiated in the tibia, 1 week after implantation of OCP and most of the cartilage was replaced by bone at week 2.However, the mandible only showed osteogenesis in response to OCP implantation at week 2, and no cartilage formation was associated with the osteogenesis.Conclusions: According to the results obtained in the present study, endochondral and intramembranous bones exhibit different biological responses to OCP implantation in rats.

  10. A combination of shear and dynamic compression leads to mechanically induced chondrogenesis of human mesenchymal stem cells

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    O Schätti

    2011-10-01

    Full Text Available ere is great interest in how bone marrow derived stem cells make fate decisions. Numerous studies have investigated the role of individual growth factors on mesenchymal stem cell differentiation, leading to protocols for cartilage, bone and adipose tissue. However, these protocols overlook the role of biomechanics on stem cell differentiation. There have been various studies that have applied mechanical stimulation to constructs containing mesenchymal stem cells, with varying degrees of success. One critical fate decision is that between cartilage and bone. Articular motion is a combination of compressive, tensile and shear deformations; therefore, one can presume that compression alone is unlikely to be a sufficient mechanical signal to generate a cartilage-like tissue in vitro. Within this study, we aimed to determine the role of shear on the fate of stem cell differentiation. Specifically, we investigated the potential enhancing effect of surface shear, superimposed on cyclic axial compression, on chondrogenic differentiation of human bone marrow-derived stem cells. Using a custom built loading device we applied compression, shear or a combination of both stimuli onto fibrin/polyurethane composites in which human mesenchymal stem cells were embedded, while no exogenous growth-factors were added to the culture medium. Both compression or shear alone was insufficient for the chondrogenic induction of human mesenchymal stem cells. However, the application of shear superimposed upon dynamic compression led to significant increases in chondrogenic gene expression. Histological analysis detected sulphated glycosaminoglycan and collagen II only in the compression and shear group. The results obtained may provide insight into post-operative care after cell therapy involving mesenchymal stromal cells.

  11. microRNA-140 Inhibits Inflammation and Stimulates Chondrogenesis in a Model of Interleukin 1β-induced Osteoarthritis

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    Tommy A Karlsen

    2016-01-01

    Full Text Available Osteoarthritis is a serious disease of articular cartilage. The pathogenic factors contributing to this disorder are inflammation, extracellular matrix degradation and failure to rebuild the articular cartilage. Preclinical studies suggest that microRNA-140 may play a protective role in osteoarthritis development, but little is known about the mechanism by which this occurs. Here we present the results of forced expression of microRNA-140 in an in vitro model of osteoarthritis, evaluated by global proteomics analysis. We show that inflammation was reduced through the altered levels of multiple proteins involved in the nuclear factor of kappa light polypeptide gene enhancer in B-cells 1 pathway. microRNA-140 upregulated many of the components involved in the synthesis of hyaline extracellular matrix and reduced the levels of aggrecanases and syndecan 4, thus potentially both increasing cartilage repair and reducing cartilage breakdown. These results show how forced expression of microRNA-140 is likely to counteract all three pathogenic processes, and support the idea that intra-articular injection of microRNA-140 may benefit patients suffering from early osteoarthritis.

  12. Study on the effects of gradient mechanical pressures on the proliferation, apoptosis, chondrogenesis and hypertrophy of mandibular condylar chondrocytes in vitro.

    Science.gov (United States)

    Li, Hui; Huang, Linjian; Xie, Qianyang; Cai, Xieyi; Yang, Chi; Wang, Shaoyi; Zhang, Min

    2017-01-01

    To investigate the effects of gradient mechanical pressure on chondrocyte proliferation, apoptosis, and the expression of markers of chondrogenesis and chondrocyte hypertrophy. Mandibular condylar chondrocytes from 5 rabbits were cultured in vitro, and pressed with static pressures of 50kPa, 100kPa, 150kPa and 200kPa for 3h, respectively. The chondrocytes cultured without pressure (0kPa) were used as control. Cell proliferation, apoptosis, and the expression of aggrecan (AGG), collagen II (COL2), collagen X (COL10), alkaline phosphatase (ALP) were investigated. Ultrastructures of the pressurized chondrocytes under transmission electron microscopy (TEM) were observed. Chondrocyte proliferation increased at 100kPa and decreased at 200kPa. Chondrocyte apoptosis increased with peak pressure at 200kPa in a dose-dependent manner. Chondrocyte necrosis increased at 200kPa. The expression of AGG increased at 200kPa. The expression of COL2 decreased at 50kPa and increased at 150kPa. The expression of COL10 and ALP increased at 150kPa. Ultrastructure of the pressurized chondrocytes under TEM showed: at 100kPa, cells were enlarged with less cellular microvillus and a bigger nucleus; at 200kPa, cells shrank with the sign of apoptosis, and apoptosis cells were found. The mechanical loading of 150kPa is the moderate pressure for chondrocyte: cell proliferation and apoptosis is balanced, necrosis is reduced, and chondrogenesis and chondrocyte hypertrophy are promoted. When the pressure is lower, chondrogenesis and chondrocyte hypertrophy are inhibited. At 200kPa, degeneration of cartilage is implied. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Study of Carbon Nano-Tubes Effects on the Chondrogenesis of Human Adipose Derived Stem Cells in Alginate Scaffold

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    Ali Valiani

    2014-01-01

    Full Text Available Background: Osteoarthritis is one of the most common diseases in middle-aged populations in the World and could become the fourth principal cause of disability by the year 2020. One of the critical properties for cartilage tissue engineering (TE is the ability of scaffolds to closely mimic the extracellular matrix and bond to the host tissue. Therefore, TE has been presented as a technique to introduce the best combination of cells and biomaterial scaffold and to stimulate growth factors to produce a cartilage tissue resembling natural articular cartilage. The aim of study is to improve differentiation of adipose derived stem cells (ADSCs into chondrocytes in order to provide a safe and modern treatment for patients suffering from cartilage damages. Methods: After functionalization, dispersions and sterilizing carbon nano-tubes (CNTs, a new type of nanocomposite gel was prepared from water-soluble CNTs and alginate. ADSCs seeded in 1.5% alginate scaffold and cultured in chondrogenic media with and without transforming growth factor-β1 (TGF-β1 for 7 and 14 days. The genes expression of sex determining region Y-box 9 (SOX9, types II and X collagens was assessed by real-time polymerase chain reaction and the amount of aggrecan (AGC and type I collagen was measured by ELISA. Results: Our findings showed that the expression of essential cartilage markers, SOX9, type II collagen and AGC, in differentiated ADSCs at the concentration of 1 μg/ml CNTs in the presence of TGF-β1 were significantly increased in comparison with the control group (P < 0.001. Meanwhile, type X collagen expression and also type I collagen production were significantly decreased (P < 0.001. Conclusions: The results showed that utilized three-dimensional scaffold had a brilliant effect in promoting gene expression of chondrogenesis.

  14. The effect of estrogen on the expression of cartilage-specific genes in the chondrogenesis process of adipose-derived stem cells

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    Farzaneh Sadeghi

    2015-01-01

    Full Text Available Background: During adolescence, sex hormones play an important role in regulating proliferation, differentiation, maturation, and the scheduled death of chondrocytes. Although some studies have reported the regulatory role of estrogen in the development and progression of cartilage, some of the mechanisms still remain unclear, including the role of estrogen in the expression of cartilage-specific genes in chondrogenesis process, which we cover in this study. Materials and Methods: In the present study, we used adipose-derived stem cells (ADSCs to differentiate into cartilage. Differentiated cartilage cells were used in the control (without estrogen E2 in the culture medium and experimental (with estrogen in the culture medium groups to evaluate the expression of type II collagen and aggrecan as chondrogenic genes markers, with -real-time polymerase chain reaction technique. Results: Our results indicated that estrogen leads to inhibition of type II collagen gene expression and reduction of aggrecan gene expression. Conclusion: Therefore, estrogen probably has negative effects on chondrogenesis process of ADSCs.

  15. Electroporation-mediated transfer of SOX trio genes (SOX-5, SOX-6, and SOX-9) to enhance the chondrogenesis of mesenchymal stem cells.

    Science.gov (United States)

    Kim, Hye-Joung; Im, Gun-Il

    2011-12-01

    The purpose of this study was to test the hypothesis that the SOX trio genes (SOX-5, SOX-6, and SOX-9) have a lower level of expression during the chondrogenic differentiation of mesenchymal stem cells (MSCs) compared with chondrocytes and that the electroporation-mediated gene transfer of SOX trio promotes chondrogenesis from human MSCs. An in vitro pellet culture was carried out using MSCs or chondrocytes at passage 3 and analyzed after 7 and 21 days. Then, MSCs were transfected with SOX trio genes and analyzed for the expression of chondrogenic markers after 21 days of in vitro culture. Without transforming growth factor-β1, the untransfected MSCs had a lower level of SOX trio gene and protein expression than chondrocytes. However, the level of SOX-9 gene expression increased in MSCs when treated with transforming growth factor-β1. GAG level significantly increased 7-fold in MSCs co-transfected with SOX trio, which was corroborated by Safranin-O staining. SOX trio co-transfection significantly increased COL2A1 gene and protein and decreased COL10A1 protein in MSCs. It is concluded that the SOX trio have a significantly lower expression in human MSCs than in chondrocytes and that the electroporation-mediated co-transfection of SOX trio enhances chondrogenesis and suppresses hypertrophy of human MSCs.

  16. Bone marrow-derived mesenchymal stem cells express the pericyte marker 3G5 in culture and show enhanced chondrogenesis in hypoxic conditions.

    Science.gov (United States)

    Khan, Wasim S; Adesida, Adetola B; Tew, Simon R; Lowe, Emma T; Hardingham, Timothy E

    2010-06-01

    Bone marrow-derived mesenchymal stem cells are a potential source of cells for the repair of articular cartilage defects. Hypoxia has been shown to improve chondrogenesis in some cells. In this study, bone marrow-derived stem cells were characterized and the effects of hypoxia on chondrogenesis investigated. Adherent bone marrow colony-forming cells were characterized for stem cell surface epitopes, and then cultured as cell aggregates in chondrogenic medium under normoxic (20% oxygen) or hypoxic (5% oxygen) conditions. The cells stained strongly for markers of adult mesenchymal stem cells, and a high number of cells were also positive for the pericyte marker 3G5. The cells showed a chondrogenic response in cell aggregate cultures and, in lowered oxygen, there was increased matrix accumulation of proteoglycan, but less cell proliferation. In hypoxia, there was increased expression of key transcription factor SOX6, and of collagens II and XI, and aggrecan. Pericytes are a candidate stem cell in many tissue, and our results show that bone marrow-derived mesenchymal stem cells express the pericyte marker 3G5. The response to chondrogenic culture in these cells was enhanced by lowered oxygen tension. This has important implications for tissue engineering applications of bone marrow-derived stem cells. (c) 2010 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  17. Chondroitin Sulfate Immobilized on a Biomimetic Scaffold Modulates Inflammation While Driving Chondrogenesis.

    Science.gov (United States)

    Corradetti, Bruna; Taraballi, Francesca; Minardi, Silvia; Van Eps, Jeffrey; Cabrera, Fernando; Francis, Lewis W; Gazze, Salvatore A; Ferrari, Mauro; Weiner, Bradley K; Tasciotti, Ennio

    2016-05-01

    Costs associated with degenerative inflammatory conditions of articular cartilage are exponentially increasing in the aging population, and evidence shows a strong clinical need for innovative therapies. Stem cell-based therapies represent a promising strategy for the treatment of innumerable diseases. Their regenerative potential is undeniable, and it has been widely exploited in many tissue-engineering approaches, especially for bone and cartilage repair. Their immune-modulatory capacities in particular make stem cell-based therapeutics an attractive option for treating inflammatory diseases. However, because of their great plasticity, mesenchymal stem cells (MSCs) are susceptible to different external factors. Biomaterials capable of concurrently providing physical support to cells while acting as synthetic extracellular matrix have been established as a valuable strategy in cartilage repair. Here we propose a chondroitin sulfate-based biomimetic scaffold that recapitulates the physicochemical features of the chondrogenic niche and retains MSC immunosuppressive potential in vitro, either in response to a proinflammatory cytokine or in the presence of stimulated peripheral blood mononuclear cells. In both cases, a significant increase in the production of molecules associated with immunosuppression (nitric oxide and prostaglandins), as well as in the expression of their inducible enzymes (iNos, Pges, Cox-2, and Tgf-β). When implanted subcutaneously in rats, our scaffold revealed a reduced infiltration of leukocytes at 24 hours, which correlated with a greater upregulation of genes involved in inflammatory cell apoptotic processes. In support of its effective use in tissue-engineering applications of cartilage repair, the potential of the proposed platform to drive chondrogenic and osteogenic differentiation of MSC was also proven. Recently, increasing clinical evidence has highlighted the important role of proinflammatory mediators and infiltrating inflammatory

  18. Pleiotrophin commits human bone marrow mesenchymal stromal cells towards hypertrophy during chondrogenesis.

    Science.gov (United States)

    Bouderlique, Thibault; Henault, Emilie; Lebouvier, Angelique; Frescaline, Guilhem; Bierling, Phillipe; Rouard, Helene; Courty, José; Albanese, Patricia; Chevallier, Nathalie

    2014-01-01

    Pleiotrophin (PTN) is a growth factor present in the extracellular matrix of the growth plate during bone development and in the callus during bone healing. Bone healing is a complicated process that recapitulates endochondral bone development and involves many cell types. Among those cells, mesenchymal stromal cells (MSC) are able to differentiate toward chondrogenic and osteoblastic lineages. We aimed to determine PTN effects on differentiation properties of human bone marrow stromal cells (hBMSC) under chondrogenic induction using histological analysis and quantitative reverse transcription polymerase chain reaction. PTN dramatically potentiated chondrogenic differentiation as indicated by a strong increase of collagen 2 protein, and cartilage-related gene expression. Moreover, PTN increased transcription of hypertrophic chondrocyte markers such as MMP13, collagen 10 and alkaline phosphatase and enhanced calcification and the content of collagen 10 protein. These effects are dependent on PTN receptors signaling and PI3 K pathway activation. These data suggest a new role of PTN in bone regeneration as an inducer of hypertrophy during chondrogenic differentiation of hBMSC.

  19. In Vitro Chondrogenesis Transformation Study of Mouse Dental Pulp Stem Cells

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    Shahrul Hisham Zainal Ariffin

    2012-01-01

    Full Text Available A major challenge in the application of mesenchymal stem cells in cartilage reconstruction is that whether the cells are able to differentiate into fully mature chondrocytes before grafting. The aim of this study was to isolate mouse dental pulp stem cells (DPSC and differentiate them into chondrocytes. For this investigation, morphological, molecular, and biochemical analyses for differentiated cells were used. To induce the chondrocyte differentiation, DPSC were cultured in chondrogenic medium (Zen-Bio, Inc.. Based on morphological analyses using toluidine blue staining, proteoglycan products appear in DPSC after 21 days of chondrocyte induction. Biochemical analyses in differentiated group showed that alkaline phosphatase activity was significantly increased at day 14 as compared to control (P<0.05. Cell viability analyses during the differentiation to chondrocytes also showed that these cells were viable during differentiation. However, after the 14th day of differentiation, there was a significant decrease (P<0.05 in the viability proportion among differentiated cells as compared to the control cells. In RT-PCR molecular analyses, mouse DPSC expressed Cd146 and Cd166 which indicated that these cells belong to mesenchymal stem cells. Coll I and Coll II markers showed high expression after 14 and 21 days, respectively. In conclusion, this study showed that DPSC successfully differentiated into chondrocytes.

  20. Pleiotrophin commits human bone marrow mesenchymal stromal cells towards hypertrophy during chondrogenesis.

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    Thibault Bouderlique

    Full Text Available Pleiotrophin (PTN is a growth factor present in the extracellular matrix of the growth plate during bone development and in the callus during bone healing. Bone healing is a complicated process that recapitulates endochondral bone development and involves many cell types. Among those cells, mesenchymal stromal cells (MSC are able to differentiate toward chondrogenic and osteoblastic lineages. We aimed to determine PTN effects on differentiation properties of human bone marrow stromal cells (hBMSC under chondrogenic induction using histological analysis and quantitative reverse transcription polymerase chain reaction. PTN dramatically potentiated chondrogenic differentiation as indicated by a strong increase of collagen 2 protein, and cartilage-related gene expression. Moreover, PTN increased transcription of hypertrophic chondrocyte markers such as MMP13, collagen 10 and alkaline phosphatase and enhanced calcification and the content of collagen 10 protein. These effects are dependent on PTN receptors signaling and PI3 K pathway activation. These data suggest a new role of PTN in bone regeneration as an inducer of hypertrophy during chondrogenic differentiation of hBMSC.

  1. Indian hedgehog gene transfer is a chondrogenic inducer of human mesenchymal stem cells

    Science.gov (United States)

    2012-01-01

    Introduction To date, no single most-appropriate factor or delivery method has been identified for the purpose of mesenchymal stem cell (MSC)-based treatment of cartilage injury. Therefore, in this study we tested whether gene delivery of the growth factor Indian hedgehog (IHH) was able to induce chondrogenesis in human primary MSCs, and whether it was possible by such an approach to modulate the appearance of chondrogenic hypertrophy in pellet cultures in vitro. Methods First-generation adenoviral vectors encoding the cDNA of the human IHH gene were created by cre-lox recombination and used alone or in combination with adenoviral vectors, bone morphogenetic protein-2 (Ad.BMP-2), or transforming growth factor beta-1 (Ad.TGF-β1) to transduce human bone-marrow derived MSCs at 5 × 102 infectious particles/cell. Thereafter, 3 × 105 cells were seeded into aggregates and cultured for 3 weeks in serum-free medium, with untransduced or marker gene transduced cultures as controls. Transgene expressions were determined by ELISA, and aggregates were analysed histologically, immunohistochemically, biochemically and by RT-PCR for chondrogenesis and hypertrophy. Results IHH, TGF-β1 and BMP-2 genes were equipotent inducers of chondrogenesis in primary MSCs, as evidenced by strong staining for proteoglycans, collagen type II, increased levels of glycosaminoglycan synthesis, and expression of mRNAs associated with chondrogenesis. IHH-modified aggregates, alone or in combination, also showed a tendency to progress towards hypertrophy, as judged by the expression of alkaline phosphatase and stainings for collagen type X and Annexin 5. Conclusion As this study provides evidence for chondrogenic induction of MSC aggregates in vitro via IHH gene delivery, this technology may be efficiently employed for generating cartilaginous repair tissues in vivo. PMID:22817660

  2. MEK/ERK and p38 MAPK regulate chondrogenesis of rat bone marrow mesenchymal stem cells through delicate interaction with TGF-beta1/Smads pathway.

    Science.gov (United States)

    Li, J; Zhao, Z; Liu, J; Huang, N; Long, D; Wang, J; Li, X; Liu, Y

    2010-08-01

    This study was carried out to reveal functions and mechanisms of MEK/ERK and p38 pathways in chondrogenesis of rat bone marrow mesenchymal stem cells (BMSCs), and to investigate further any interactions between the mitogen-activated protein kinase (MAPK) and transforming growth factor-beta1 (TGF-beta1)/Smads pathway in the process. Chondrogenic differentiation of rat BMSCs was initiated in micromass culture, in the presence of TGF-beta1, for 2 weeks. ERK1/2 and p38 kinase activities were investigated by Western Blot analysis. Specific MAPK inhibitors PD98059 and SB20350 were employed to investigate regulatory effects of MEK/ERK and p38 signals on gene expression of chondrocyte-specific markers, and TGF-beta1 downstream pathways of Smad2/3. ERK1/2 was phosphorylated in a rapid but transient manner, whereas p38 was activated in a slow and sustained way. The two MAPK subtypes played opposing roles in mediating transcription of cartilage-specific genes for Col2alpha and aggrecan. TGF-beta1-stimulated gene expression of chondrogenic regulators, Sox9, Runx2 and Ihh, was also affected by activity of PD98059 and SB203580, to different degrees. However, influences of MAPK inhibitors on gene expression were relatively minor when not treated with TGF-beta1. In addition, gene transcription of Smad2/3 was significantly upregulated by TGF-beta1, but was regulated more subtly by treatment with MAPK inhibitors. MAPK subtypes seemed to regulate chondrogenesis with a delicate balance, interacting with the TGF-beta1/Smads signalling pathway.

  3. Changes in expression of cartilaginous genes during chondrogenesis of Wharton's jelly mesenchymal stem cells on three-dimensional biodegradable poly(L-lactide-co-glycolide) scaffolds.

    Science.gov (United States)

    Paduszyński, Piotr; Aleksander-Konert, Ewelina; Zajdel, Alicja; Wilczok, Adam; Jelonek, Katarzyna; Witek, Andrzej; Dzierżewicz, Zofia

    2016-01-01

    In cartilage tissue regeneration, it is important to develop biodegradable scaffolds that provide a structural and logistic template for three-dimensional cultures of chondrocytes. In this study, we evaluated changes in expression of cartilaginous genes during in vitro chondrogenic differentiation of WJ-MSCs on PLGA scaffolds. The biocompatibility of the PLGA material was investigated using WJ-MSCs by direct and indirect contact methods according to the ISO 10993-5 standard. PLGA scaffolds were fabricated by the solvent casting/salt-leaching technique. We analyzed expression of chondrogenic genes of WJ-MSCs after a 21-day culture. The results showed the biocompatibility of PLGA and confirmed the usefulness of PLGA as material for fabrication of 3D scaffolds that can be applied for WJ-MSC culture. The in vitro penetration and colonization of the scaffolds by WJ-MSCs were assessed by confocal microscopy. The increase in cell number demonstrated that scaffolds made of PLGA copolymers enabled WJ-MSC proliferation. The obtained data showed that as a result of chondrogenesis of WJ-MSCs on the PLGA scaffold the expression of the key markers collagen type II and aggrecan was increased. The observed changes in transcriptional activity of cartilaginous genes suggest that the PLGA scaffolds may be applied for WJ-MSC differentiation. This primary study suggests that chondrogenic capacity of WJ-MSCs cultured on the PLGA scaffolds can be useful for cell therapy of cartilage.

  4. A new source of mesenchymal stem cells for articular cartilage repair: MSCs derived from mobilized peripheral blood share similar biological characteristics in vitro and chondrogenesis in vivo as MSCs from bone marrow in a rabbit model.

    Science.gov (United States)

    Fu, Wei-Li; Zhou, Chun-Yan; Yu, Jia-Kuo

    2014-03-01

    Bone marrow (BM) has been considered as a major source of mesenchymal stem cells (MSCs), but it has many disadvantages in clinical application. However, MSCs from peripheral blood (PB) could be obtained by a less invasive method and be more beneficial for autologous transplantation than BM MSCs, which makes PB a promising source for articular cartilage repair in clinical use. To assess whether MSCs from mobilized PB of New Zealand White rabbits have similar biological characteristics in vitro and chondrogenesis in vivo as BM MSCs. Controlled laboratory study. A combined method of drug administration containing granulocyte colony stimulating factor (G-CSF) plus CXCR4 antagonist AMD3100 was adopted to mobilize the PB stem cells of adult New Zealand White rabbits in vitro. The isolated cells were identified as MSCs by morphological characteristics, surface markers, and differentiation potentials. A comparison between PB MSCs and BM MSCs was made in terms of biological characteristics in vitro and chondrogenesis in vivo. This issue was investigated from the aspects of morphology, immune phenotype, multiple differentiation capacity, expansion potential, antiapoptotic capacity, and ability to repair cartilage defects in vivo of PB MSCs compared with BM MSCs. Peripheral blood MSCs were successfully mobilized by the method of combined drug administration, then isolated, expanded, and identified in vitro. No significant difference was found concerning the morphology, immune phenotype, and antiapoptotic capacity between PB MSCs and BM MSCs. Significantly, MSCs from both sources compounded with decalcified bone matrix showed the same ability to repair cartilage defects in vivo. For multipluripotency, BM MSCs exhibited a more osteogenic potential and higher proliferation capacity than PB MSCs, whereas PB MSCs possessed a stronger adipogenic and chondrogenic differentiation potential than BM MSCs in vitro. Although there are some differences in the proliferation and

  5. A comparison of three-dimensional culture systems to evaluate in vitro chondrogenesis of equine bone marrow-derived mesenchymal stem cells.

    Science.gov (United States)

    Watts, Ashlee E; Ackerman-Yost, Jeremy C; Nixon, Alan J

    2013-10-01

    To compare in vitro three-dimensional (3D) culture systems that model chondrogenesis of bone marrow-derived mesenchymal stem cells (MSCs). MSCs from five horses 2-3 years of age were consolidated in fibrin 0.3% alginate, 1.2% alginate, 2.5×10(5) cell pellets, 5×10(5) cell pellets, and 2% agarose, and maintained in chondrogenic medium with supplemental TGF-β1 for 4 weeks. Pellets and media were tested at days 1, 14, and 28 for gene expression of markers of chondrogenic maturation and hypertrophy (ACAN, COL2B, COL10, SOX9, 18S), and evaluated by histology (hematoxylin and eosin, Toluidine Blue) and immunohistochemistry (collagen type II and X). alginate, fibrin alginate (FA), and both pellet culture systems resulted in chondrogenic transformation. Adequate RNA was not obtained from agarose cultures at any time point. There was increased COL2B, ACAN, and SOX9 expression on day 14 from both pellet culture systems. On day 28, increased expression of COL2B was maintained in 5×10(5) cell pellets and there was no difference in ACAN and SOX9 between FA and both pellet cultures. COL10 expression was significantly lower in FA cultures on day 28. Collagen type II was abundantly formed in all culture systems except alginate and collagen type X was least in FA hydrogels. equine MSCs respond to 3D culture in FA blended hydrogel and both pellet culture systems with chondrogenic induction. For prevention of terminal differentiation and hypertrophy, FA culture may be superior to pellet culture systems.

  6. Differential expression pattern of extracellular matrix molecules during chondrogenesis of mesenchymal stem cells from bone marrow and adipose tissue

    DEFF Research Database (Denmark)

    Mehlhorn, A T; Niemeyer, P; Kaiser, S

    2006-01-01

    Adipose-derived adult stem cells (ADASCs) or bone marrow-derived mesenchymal stem cells (BMSCs) are considered as alternative cell sources for cell-based cartilage repair due to their ability to produce cartilage-specific matrix. This article addresses the differential expression pattern...... chondroinduction. TGF-beta1 induces alternative splicing of the alpha(1)-procollagen type II transcript in BMSCs, but not in ADASCs. These findings may direct the development of a cell-specific culture environment either to prevent hypertrophy in BMSCs or to promote chondrogenic maturation in ADASCs....

  7. Effects of CD14 macrophages and proinflammatory cytokines on chondrogenesis in osteoarthritic synovium-derived stem cells.

    Science.gov (United States)

    Han, Sun Ae; Lee, Sahnghoon; Seong, Sang Cheol; Lee, Myung Chul

    2014-10-01

    We investigated the effects of CD14 macrophages and proinflammatory cytokines on chondrogenic differentiation of osteoarthritic synovium-derived stem cells (SDSCs). Osteoarthritic synovial fluid was analyzed for interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), and IL-6. Levels of stem cell surface markers in osteoarthritic SDSCs were evaluated using flow cytometry. CD14-negative cells were obtained using magnetically activated cell sorting. We compared chondrogenic potentials between whole cells and CD14-negative cells in CD14(low) cells and CD14(high) cells, respectively. To assess whether nuclear factor-κB (NF-κB) and CCAAT/enhancer-binding protein β (C/EBPβ) modulate IL-1β-induced alterations in chondrogenic potential, we performed small interfering RNA transfection. We observed a significant correlation between the CD14 ratio in osteoarthritic SDSCs and IL-1β and TNF-α in osteoarthritic synovial fluid. Phenotypic characterization of whole cells and CD14-negative cells showed no significant differences in levels of stem cell markers. mRNA expression of type II collagen was higher in CD14-negative cell pellets than in whole cell pellets. Immunohistochemical staining indicated higher levels of type II collagen in the CD14-negative cell pellets of CD14(high) cells than in whole cell pellets of CD14(high) cells. As expected, IL-1β and TNF-α significantly inhibited the expression of chondrogenic-related genes in SDSCs, an effect which was antagonized by knockdown of NF-κB and C/EBPβ. Our results suggest that depletion of CD14(+) synovial macrophages leads to improved chondrogenic potential in CD14(high) cell populations in osteoarthritic SDSCs, and that NF-κB (RelA) and C/EBPβ are critical factors mediating IL-1β-induced suppression of the chondrogenic potential of human SDSCs.

  8. Designer Self-Assembling Peptide Nanofiber Scaffolds Containing Link Protein N-Terminal Peptide Induce Chondrogenesis of Rabbit Bone Marrow Stem Cells

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    Baichuan Wang

    2014-01-01

    Full Text Available Designer self-assembling peptide nanofiber hydrogel scaffolds have been considered as promising biomaterials for tissue engineering because of their excellent biocompatibility and biofunctionality. Our previous studies have shown that a novel designer functionalized self-assembling peptide nanofiber hydrogel scaffold (RLN/RADA16, LN-NS containing N-terminal peptide sequence of link protein (link N can promote nucleus pulposus cells (NPCs adhesion and three-dimensional (3D migration and stimulate biosynthesis of type II collagen and aggrecan by NPCs in vitro. The present study has extended these investigations to determine the effects of this functionalized LN-NS on bone marrow stem cells (BMSCs, a potential cell source for NP regeneration. Although the functionalized LN-NS cannot promote BMSCs proliferation, it significantly promotes BMSCs adhesion compared with that of the pure RADA16 hydrogel scaffold. Moreover, the functionalized LN-NS remarkably stimulates biosynthesis and deposition of type II collagen and aggrecan. These data demonstrate that the functionalized peptide nanofiber hydrogel scaffold containing link N peptide as a potential matrix substrate will be very useful in the NP tissue regeneration.

  9. Using the interplay of magnetic guidance and controlled TGF-β release from protein-based nanocapsules to stimulate chondrogenesis.

    Science.gov (United States)

    Chiang, Chih-Sheng; Chen, Jian-Yi; Chiang, Min-Yu; Hou, Kai-Ting; Li, Wei-Ming; Chang, Shwu-Jen; Chen, San-Yuan

    2018-01-01

    Stimulating the proliferation and differentiation of chondrocytes for the regeneration of articular cartilage is a promising strategy, but it is currently ineffective. Although both physical stimulation and growth factors play important roles in cartilage repair, their interplay remains unclear and requires further investigation. In this study, we aimed to clarify their contribution using a magnetic drug carrier that not only can deliver growth factors but also provide an external stimulation to cells in the two-dimensional environment. We developed a nanocapsule (transforming growth factor-β1 [TGF-β1]-loaded magnetic amphiphilic gelatin nanocapsules [MAGNCs]; TGF-β1@MAGNCs) composed of hexanoic-anhydride-grafted gelatin and iron oxide nanoparticles to provide a combination treatment of TGF-β1 and magnetically induced physical stimuli. With the expression of Arg-Gly-Asp peptide in the gelatin, the TGF-β1@MAGNCs have an inherent affinity for chondrogenic ATDC5 cells. In the absence of TGF-β1, ATDC5 cells treated with a magnetic field show significantly upregulated Col2a1 expression. Moreover, TGF-β1 slowly released from biodegradable TGF-β1@ MAGNCs further improves the differentiation with increased expression of Col2a1 and Aggrecan. Our study shows the time-dependent interplay of physical stimuli and growth factors on chondrogenic regeneration, and demonstrates the promising use of TGF-β1@MAGNCs for articular cartilage repair.

  10. Transcriptional signature of human adipose tissue-derived stem cells (hASCs) preconditioned for chondrogenesis in hypoxic conditions

    International Nuclear Information System (INIS)

    Pilgaard, L.; Lund, P.; Duroux, M.; Lockstone, H.; Taylor, J.; Emmersen, J.; Fink, T.; Ragoussis, J.; Zachar, V.

    2009-01-01

    Hypoxia is an important factor involved in the control of stem cells. To obtain a better insight into the phenotypical changes brought about by hypoxic preconditioning prior to chondrogenic differentiation; we have investigated growth, colony-forming and chondrogenic capacity, and global transcriptional responses of six adipose tissue-derived stem cell lines expanded at oxygen concentrations ranging from ambient to 1%. The assessment of cell proliferation and colony-forming potential revealed that the hypoxic conditions corresponding to 1% oxygen played a major role. The chondrogenic inducibility, examined by high-density pellet model, however, did not improve on hypoxic preconditioning. While the microarray analysis revealed a distinctive inter-donor variability, the exposure to 1% hypoxia superseded the biological variability and produced a specific expression profile with 2581 significantly regulated genes and substantial functional enrichment in the pathways of cell proliferation and apoptosis. Additionally, exposure to 1% oxygen resulted in upregulation of factors related to angiogenesis and cell growth. In particular, leptin (LEP), the key regulator of body weight and food intake was found to be highly upregulated. In conclusion, the results of this investigation demonstrate the significance of donor demographics and the importance of further studies into the use of regulated oxygen tension as a tool for preparation of ASCs in order to exploit their full potential.

  11. Crystallization and X-ray diffraction analysis of the HMG domain of the chondrogenesis master regulator Sox9 in complex with a ChIP-Seq-identified DNA element

    Energy Technology Data Exchange (ETDEWEB)

    Vivekanandan, Saravanan; Moovarkumudalvan, Balasubramanian; Lescar, Julien; Kolatkar, Prasanna R.

    2015-10-30

    Sox9 is a fundamental sex-determining gene and the master regulator of chondrogenesis, and is involved in the development of various vital organs such as testes, kidney, heart and brain, and in skeletal development. Similar to other known Sox transcription factors, Sox9 recognizes and binds DNA with the consensus sequence C(T/A)TTG(T/A)(T/A) through the highly conserved HMG domain. Nonetheless, the molecular basis of the functional specificity of Sox9 in key developmental processes is still unclear. As an initial step towards a mechanistic understanding of Sox9 transcriptional regulation, the current work describes the details of the purification of the mouse Sox9 HMG domain (mSox9HMG), its crystallization in complex with a ChIP-Seq-identified FOXP2 promoter DNA element and the X-ray diffraction data analysis of this complex. The mSox9HMG–FOXP2 promoter DNA complex was crystallized by the hanging-drop vapour-diffusion method using 20% PEG 3350 in 200 mMsodium/potassium phosphate with 100 mMbis-tris propane at pH 8.5. The crystals diffracted to 2.7 Å resolution and the complex crystallized in the tetragonal space groupP41212, with unit-cell parametersa=b= 99.49,c= 45.89 Å. Crystal-packing parameters revealed that asymmetric unit contained one mSox9HMG–FOXP2 promoter DNA complex with an estimated solvent content of 64%.

  12. The effects of cyclic hydrostatic pressure on chondrogenesis and viability of human adipose- and bone marrow-derived mesenchymal stem cells in three-dimensional agarose constructs.

    Science.gov (United States)

    Puetzer, Jennifer; Williams, John; Gillies, Allison; Bernacki, Susan; Loboa, Elizabeth G

    2013-01-01

    This study investigates the effects of cyclic hydrostatic pressure (CHP) on chondrogenic differentiation of human adipose-derived stem cells (hASCs) in three-dimensional (3-D) agarose constructs maintained in a complete growth medium without soluble chondrogenic inducing factors. hASCs were seeded in 2% agarose hydrogels and exposed to 7.5 MPa CHP for 4 h per day at a frequency of 1 Hz for up to 21 days. On days 0, 7, 14, and 21, the expression levels of collagen II, Sox9, aggrecan, and cartilage oligomeric matrix protein (COMP) were examined by real-time reverse transcriptase-polymerase chain reaction analysis. Gene expression analysis found collagen II mRNA expression in only the CHP-loaded construct at day 14 and at no other time during the study. CHP-loaded hASCs exhibited upregulated mRNA expression of Sox9, aggrecan, and COMP at day 7 relative to unloaded controls, suggesting that CHP initiated chondrogenic differentiation of hASCs in a manner similar to human bone marrow-derived mesenchymal stem cells (hMSC). By day 14, however, loaded hASC constructs exhibited significantly lower mRNA expression of the chondrogenic markers than unloaded controls. Additionally, by day 21, the samples exhibited little measurable mRNA expression at all, suggesting a decreased viability. Histological analysis validated the lack of mRNA expression at day 21 for both the loaded and unloaded control samples with a visible decrease in the cell number and change in morphology. A comparative study with hASCs and hMSCs further examined long-term cell viability in 3-D agarose constructs of both cell types. Decreased cell metabolic activity was observed throughout the 21-day experimental period in both the CHP-loaded and control constructs of both hMSCs and hASCs, suggesting a decrease in cell metabolic activity, alluding to a decrease in cell viability. This suggests that a 2% agarose hydrogel may not optimally support hASC or hMSC viability in a complete growth medium in the

  13. Mechanism of cancer-induced bone destruction: An association of connective tissue growth factor (CTGF/CCN2 in the bone metastasis

    Directory of Open Access Journals (Sweden)

    Tsuyoshi Shimo

    2011-02-01

    Full Text Available Connective tissue growth factor (CTGF/CCN2 is a member of the CCN family, a novel class of extracellular signal modulators. CCN2 is composed of four conserved modules connected in tandem, each of which is rich in cysteines and highly interactive with other molecules. CCN2 has various biological functions, being active in developmental processes including angiogenesis, chondrogenesis, and osteogenesis. Recently CCN2 has gained more clinical interest due to its role in cancer-induced bone destruction. In this article, the role of CCN2 in bone-destroying events as an organizer of the microenvironmental cell society is comprehensively described, and a brief summary of the recent findings on regulatory factors involved in tumor-induced bone disease is given.

  14. Fibroblast-Derived Extracellular Matrix Induces Chondrogenic Differentiation in Human Adipose-Derived Mesenchymal Stromal/Stem Cells in Vitro

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    Kevin Dzobo

    2016-08-01

    Full Text Available Mesenchymal stromal/stem cells (MSCs represent an area being intensively researched for tissue engineering and regenerative medicine applications. MSCs may provide the opportunity to treat diseases and injuries that currently have limited therapeutic options, as well as enhance present strategies for tissue repair. The cellular environment has a significant role in cellular development and differentiation through cell–matrix interactions. The aim of this study was to investigate the behavior of adipose-derived MSCs (ad-MSCs in the context of a cell-derived matrix so as to model the in vivo physiological microenvironment. The fibroblast-derived extracellular matrix (fd-ECM did not affect ad-MSC morphology, but reduced ad-MSC proliferation. Ad-MSCs cultured on fd-ECM displayed decreased expression of integrins α2 and β1 and subsequently lost their multipotency over time, as shown by the decrease in CD44, Octamer-binding transcription factor 4 (OCT4, SOX2, and NANOG gene expression. The fd-ECM induced chondrogenic differentiation in ad-MSCs compared to control ad-MSCs. Loss of function studies, through the use of siRNA and a mutant Notch1 construct, revealed that ECM-mediated ad-MSCs chondrogenesis requires Notch1 and β-catenin signaling. The fd-ECM also showed anti-senescence effects on ad-MSCs. The fd-ECM is a promising approach for inducing chondrogenesis in ad-MSCs and chondrogenic differentiated ad-MSCs could be used in stem cell therapy procedures.

  15. Poly(dl)lactic acid/polyglycolic acid/iron and poly(dl)lactic acid/polyglycolic acid/samarium cobalt composites for use as a delivery mechanism for magnetically directed chondrogenesis

    Science.gov (United States)

    Oppermann, Dean Alan

    Magnetically directed chondrogenesis (MDC) is a fundamental approach to articular cartilage repair. In MDC a magnet is implanted into the subchondral trabecular bone underlying a cartilage defect and used to attract chondrocytes, magnetically tagged with Fe nanoparticles, to the defect site. Pilot studies by Halpern, Crimp and Grande, using solid neodymium (Nd) magnets, indicated optimistic results by producing a hyaline-like articular cartilage after 8 weeks implantation. Since solid Nd magnets introduce long-term biocompatibility issues, the focus of this dissertation was to develop P(dl)A/PGA/Fe and P(dl)A/PGA/SmCo 5 implants for use in MDC. The effect of implant porosity, implant composition and magnetic material (Fe or SmCo5) on the initial and degraded magnetic properties were evaluated. The biocompatibility of P(dl)A/PGA/Fe implants were investigated by implantation into New Zealand white rabbits for 8 weeks. The effect of hydrogen peroxide (H2O2) and ethylene oxide (EO) sterilization techniques on the molecular weight and chemical structure of P(dl)A/PGA polymers were evaluated using gel permeation chromatography and Fourier transform infrared spectroscopy. The effect of implant morphology, size and number on the von Mises stress in the trabecular bone surrounding the implant was evaluated using a finite element model. In general, SmCo5 implants resulted in higher magnetic fields initially and after 8 weeks of degradation than comparable Fe implants. Increases in magnetic field strength were achieved by increasing the volume fraction of magnetic material and by increasing the PGA concentration. The magnetic field strength degradation rate decreased with increases in volume fraction of magnetic material and increases in PLA concentration. Implantation studies indicated that 50/50 P(dl)A/PGA were more bioactive than 75/25 P(dl)A/PGA with an increased cellular response that is specific to bone growth. The compressive strength and elastic modulus of porous

  16. Role of c-Myb in chondrogenesis

    Czech Academy of Sciences Publication Activity Database

    Oralová, Veronika; Matalová, Eva; Janečková, Eva; Drobná Krejčí, E.; Knopfová, L.; Šnajdr, P.; Tucker, A. S.; Veselá, I.; Šmarda, J.; Buchtová, Marcela

    2015-01-01

    Roč. 76, č. 1 (2015), s. 97-106 ISSN 8756-3282 R&D Projects: GA ČR GCP302/12/J059; GA ČR GB14-37368G Institutional support: RVO:67985904 Keywords : micromass cultures * mouse limbs * endochondral bone Subject RIV: EA - Cell Biology Impact factor: 3.736, year: 2015

  17. Induced Abortion

    Science.gov (United States)

    ... Education & Events Advocacy For Patients About ACOG Induced Abortion Home For Patients Search FAQs Induced Abortion Page ... Induced Abortion FAQ043, May 2015 PDF Format Induced Abortion Special Procedures What is an induced abortion? What ...

  18. Directed Differentiation of Human-Induced Pluripotent Stem Cells to Mesenchymal Stem Cells.

    Science.gov (United States)

    Lian, Qizhou; Zhang, Yuelin; Liang, Xiaoting; Gao, Fei; Tse, Hung-Fat

    2016-01-01

    Multipotent stromal cells, also known as mesenchymal stem cells (MSCs), possess great potential to generate a wide range of cell types including endothelial cells, smooth muscle cells, bone, cartilage, and lipid cells. This protocol describes in detail how to perform highly efficient, lineage-specific differentiation of human-induced pluripotent stem cells (iPSCs) with an MSCs fate. The approach uses a clinically compliant protocol with chemically defined media, feeder-free conditions, and a CD105 positive and CD24 negative selection to achieve a single cell-based MSCs derivation from differentiating human pluripotent cells in approximately 20 days. Cells generated with this protocol express typical MSCs surface markers and undergo adipogenesis, osteogenesis, and chondrogenesis similar to adult bone marrow-derived MSCs (BM-MSCs). Nonetheless, compared with adult BM-MSCs, iPSC-MSCs display a higher proliferative capacity, up to 120 passages, without obvious loss of self-renewal potential and constitutively express MSCs surface antigens. MSCs generated with this protocol have numerous applications, including expansion to large scale cell numbers for tissue engineering and the development of cellular therapeutics. This approach has been used to rescue limb ischemia, allergic disorders, and cigarette smoke-induced lung damage and to model mesenchymal and vascular disorders of Hutchinson-Gilford progeria syndrome (HGPS).

  19. Intra-hydrogel culture prevents transformation of mesenchymal stem cells induced by monolayer expansion.

    Science.gov (United States)

    Jiang, Tongmeng; Liu, Junting; Ouyang, Yiqiang; Wu, Huayu; Zheng, Li; Zhao, Jinmin; Zhang, Xingdong

    2018-05-01

    In this study, we report that the intra-hydrogel culture system mitigates the transformation of mesenchymal stem cells (MSCs) induced by two-dimensional (2D) expansion. MSCs expanded in monolayer culture prior to encapsulation in collagen hydrogels (group eMSCs-CH) featured impaired stemness in chondrogenesis, comparing with the freshly isolated bone marrow mononuclear cells seeded directly in collagen hydrogels (group fMSCs-CH). The molecular mechanism of the in vitro expansion-triggered damage to MSCs was detected through genome-wide microarray analysis. Results indicated that pathways such as proteoglycans in cancer and pathways in cancer expansion were highly enriched in eMSCs-CH. And multiple up-regulated oncoma-associated genes were verified in eMSCs-CH compared with fMSCs-CH, indicating that expansion in vitro triggered cellular transformation was associated with signaling pathways related to tumorigenicity. Besides, focal adhesion (FA) and mitogen-activated protein kinase (MAPK) signaling pathways were also involved in in vitro expansion, indicating restructuring of the cell architecture. Thus, monolayer expansion in vitro may contribute to vulnerability of MSCs through the regulation of FA and MAPK. This study indicates that intra-hydrogel culture can mitigate the monolayer expansion induced transformation of MSCs and maintain the uniformity of the stem cells, which is a viable in vitro culture system for stem cell therapy.

  20. HIF-1α as a Regulator of BMP2-Induced Chondrogenic Differentiation, Osteogenic Differentiation, and Endochondral Ossification in Stem Cells

    Directory of Open Access Journals (Sweden)

    Nian Zhou

    2015-04-01

    Full Text Available Background/Aims: Joint cartilage defects are difficult to treat due to the limited self-repair capacities of cartilage. Cartilage tissue engineering based on stem cells and gene enhancement is a potential alternative for cartilage repair. Bone morphogenetic protein 2 (BMP2 has been shown to induce chondrogenic differentiation in mesenchymal stem cells (MSCs; however, maintaining the phenotypes of MSCs during cartilage repair since differentiation occurs along the endochondral ossification pathway. In this study, hypoxia inducible factor, or (HIF-1α, was determined to be a regulator of BMP2-induced chondrogenic differentiation, osteogenic differentiation, and endochondral bone formation. Methods: BMP2 was used to induce chondrogenic and osteogenic differentiation in stem cells and fetal limb development. After HIF-1α was added to the inducing system, any changes in the differentiation markers were assessed. Results: HIF-1α was found to potentiate BMP2-induced Sox9 and the expression of chondrogenesis by downstream markers, and inhibit Runx2 and the expression of osteogenesis by downstream markers in vitro. In subcutaneous stem cell implantation studies, HIF-1α was shown to potentiate BMP2-induced cartilage formation and inhibit endochondral ossification during ectopic bone/cartilage formation. In the fetal limb culture, HIF-1α and BMP2 synergistically promoted the expansion of the proliferating chondrocyte zone and inhibited chondrocyte hypertrophy and endochondral ossification. Conclusion: The results of this study indicated that, when combined with BMP2, HIF-1α induced MSC differentiation could become a new method of maintaining cartilage phenotypes during cartilage tissue engineering.

  1. Connective-Tissue Growth Factor (CTGF/CCN2 Induces Astrogenesis and Fibronectin Expression of Embryonic Neural Cells In Vitro.

    Directory of Open Access Journals (Sweden)

    Fabio A Mendes

    Full Text Available Connective-tissue growth factor (CTGF is a modular secreted protein implicated in multiple cellular events such as chondrogenesis, skeletogenesis, angiogenesis and wound healing. CTGF contains four different structural modules. This modular organization is characteristic of members of the CCN family. The acronym was derived from the first three members discovered, cysteine-rich 61 (CYR61, CTGF and nephroblastoma overexpressed (NOV. CTGF is implicated as a mediator of important cell processes such as adhesion, migration, proliferation and differentiation. Extensive data have shown that CTGF interacts particularly with the TGFβ, WNT and MAPK signaling pathways. The capacity of CTGF to interact with different growth factors lends it an important role during early and late development, especially in the anterior region of the embryo. ctgf knockout mice have several cranio-facial defects, and the skeletal system is also greatly affected due to an impairment of the vascular-system development during chondrogenesis. This study, for the first time, indicated that CTGF is a potent inductor of gliogenesis during development. Our results showed that in vitro addition of recombinant CTGF protein to an embryonic mouse neural precursor cell culture increased the number of GFAP- and GFAP/Nestin-positive cells. Surprisingly, CTGF also increased the number of Sox2-positive cells. Moreover, this induction seemed not to involve cell proliferation. In addition, exogenous CTGF activated p44/42 but not p38 or JNK MAPK signaling, and increased the expression and deposition of the fibronectin extracellular matrix protein. Finally, CTGF was also able to induce GFAP as well as Nestin expression in a human malignant glioma stem cell line, suggesting a possible role in the differentiation process of gliomas. These results implicate ctgf as a key gene for astrogenesis during development, and suggest that its mechanism may involve activation of p44/42 MAPK signaling

  2. Different Chondrogenic Potential among Human Induced Pluripotent Stem Cells from Diverse Origin Primary Cells

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    Yeri Alice Rim

    2018-01-01

    Full Text Available Scientists have tried to reprogram various origins of primary cells into human induced pluripotent stem cells (hiPSCs. Every somatic cell can theoretically become a hiPSC and give rise to targeted cells of the human body. However, there have been debates on the controversy about the differentiation propensity according to the origin of primary cells. We reprogrammed hiPSCs from four different types of primary cells such as dermal fibroblasts (DF, n=3, peripheral blood mononuclear cells (PBMC, n=3, cord blood mononuclear cells (CBMC, n=3, and osteoarthritis fibroblast-like synoviocytes (OAFLS, n=3. Established hiPSCs were differentiated into chondrogenic pellets. All told, cartilage-specific markers tended to express more by the order of CBMC > DF > PBMC > FLS. Origin of primary cells may influence the reprogramming and differentiation thereafter. In the context of chondrogenic propensity, CBMC-derived hiPSCs can be a fairly good candidate cell source for cartilage regeneration. The differentiation of hiPSCs into chondrocytes may help develop “cartilage in a dish” in the future. Also, the ideal cell source of hiPSC for chondrogenesis may contribute to future application as well.

  3. Derivation of Mesenchymal Stromal Cells from Canine Induced Pluripotent Stem Cells by Inhibition of the TGFβ/Activin Signaling Pathway

    Science.gov (United States)

    Frith, Jessica E.; Frith, Thomas J.R.; Ovchinnikov, Dmitry A.; Cooper-White, Justin J.; Wolvetang, Ernst J.

    2014-01-01

    In this study we have generated canine mesenchymal stromal cells (MSCs), also known as mesenchymal stem cells, from canine induced pluripotent stem cells (ciPSCs) by small-molecule inhibition of the transforming growth factor beta (TGFβ)/activin signaling pathway. These ciPSC-derived MSCs (ciPSC-MSCs) express the MSC markers CD73, CD90, CD105, STRO1, cPDGFRβ and cKDR, in addition to the pluripotency factors OCT4, NANOG and REX1. ciPSC-MSCs lack immunostaining for H3K27me3, suggesting that they possess two active X chromosomes. ciPSC-MSCs are highly proliferative and undergo robust differentiation along the osteo-, chondro- and adipogenic pathways, but do not form teratoma-like tissues in vitro. Of further significance for the translational potential of ciPSC-MSCs, we show that these cells can be encapsulated and maintained within injectable hydrogel matrices that, when functionalized with bound pentosan polysulfate, dramatically enhance chondrogenesis and inhibit osteogenesis. The ability to efficiently derive large numbers of highly proliferative canine MSCs from ciPSCs that can be incorporated into injectable, functionalized hydrogels that enhance their differentiation along a desired lineage constitutes an important milestone towards developing an effective MSC-based therapy for osteoarthritis in dogs, but equally provides a model system for assessing the efficacy and safety of analogous approaches for treating human degenerative joint diseases. PMID:25055193

  4. Deciphering chondrocyte behaviour in matrix-induced autologous chondrocyte implantation to undergo accurate cartilage repair with hyaline matrix.

    Science.gov (United States)

    Demoor, M; Maneix, L; Ollitrault, D; Legendre, F; Duval, E; Claus, S; Mallein-Gerin, F; Moslemi, S; Boumediene, K; Galera, P

    2012-06-01

    Since the emergence in the 1990s of the autologous chondrocytes transplantation (ACT) in the treatment of cartilage defects, the technique, corresponding initially to implantation of chondrocytes, previously isolated and amplified in vitro, under a periosteal membrane, has greatly evolved. Indeed, the first generations of ACT showed their limits, with in particular the dedifferentiation of chondrocytes during the monolayer culture, inducing the synthesis of fibroblastic collagens, notably type I collagen to the detriment of type II collagen. Beyond the clinical aspect with its encouraging results, new biological substitutes must be tested to obtain a hyaline neocartilage. Therefore, the use of differentiated chondrocytes phenotypically stabilized is essential for the success of ACT at medium and long-term. That is why researchers try now to develop more reliable culture techniques, using among others, new types of biomaterials and molecules known for their chondrogenic activity, giving rise to the 4th generation of ACT. Other sources of cells, being able to follow chondrogenesis program, are also studied. The success of the cartilage regenerative medicine is based on the phenotypic status of the chondrocyte and on one of its essential component of the cartilage, type II collagen, the expression of which should be supported without induction of type I collagen. The knowledge accumulated by the scientific community and the experience of the clinicians will certainly allow to relief this technological challenge, which influence besides, the validation of such biological substitutes by the sanitary authorities. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

  5. Comparative molecular pathology of cadmium- and all-trans-retinoic acid-induced postaxial forelimb ectrodactyly

    International Nuclear Information System (INIS)

    Liao Xiaoyan; Lee, Grace S.; Shimizu, Hirohito; Collins, Michael D.

    2007-01-01

    Cadmium chloride (CdCl 2 ) and all-trans-retinoic acid (RA) induce postaxial forelimb ectrodactyly in C57BL/6N mice when administered during early limb development, and co-administration yields a synergistic response suggesting a common final pathway to the defect. In the current study, forelimb buds from embryos given high maternal teratogenic doses of CdCl 2 or RA, or the combination of both agents at low doses were collected at various time points after treatment on GD 9.5 and examined for cellular apoptosis, proliferation, and patterning genes. Some cellular perturbations detected in the developing limb bud were similar for both teratogens, whereas other alterations were unique to each agent. For example, at 12 and 18 h, CdCl 2 treatment increased apoptotic cells in the mesenchyme underneath the apical ectodermal ridge (AER), whereas RA caused apoptosis in the AER and proximal mesenchyme. Further, the combined low-dose treatment increased cell death synergistically in all three regions. CdCl 2 and the low-dose combined treatment inhibited mesenchymal proliferation at 12 h, which was associated with induction of p21 cip1 and inhibition of phospho-c-Jun. In contrast, RA did not inhibit mesenchymal proliferation and did not induce p21 cip1 expression or change c-Jun phosphorylation. All three treatment groups showed a delay in the patterning of distal chondrogenesis centers as indicated by Sox9 expression. There was also common inhibition in the expression of AER markers, Fgf8 and Fgf4, and the mesenchymal marker Msx1 involved in the maintenance of epithelial-mesenchymal interactions. Collectively, a model is hypothesized where limb patterning can be perturbed by insults to both ectoderm and mesoderm

  6. Creating an Animal Model of Tendinopathy by Inducing Chondrogenic Differentiation with Kartogenin.

    Science.gov (United States)

    Yuan, Ting; Zhang, Jianying; Zhao, Guangyi; Zhou, Yiqin; Zhang, Chang-Qing; Wang, James H-C

    2016-01-01

    Previous animal studies have shown that long term rat treadmill running induces over-use tendinopathy, which manifests as proteoglycan accumulation and chondrocytes-like cells within the affected tendons. Creating this animal model of tendinopathy by long term treadmill running is however time-consuming, costly and may vary among animals. In this study, we used a new approach to develop an animal model of tendinopathy using kartogenin (KGN), a bio-compound that can stimulate endogenous stem/progenitor cells to differentiate into chondrocytes. KGN-beads were fabricated and implanted into rat Achilles tendons. Five weeks after implantation, chondrocytes and proteoglycan accumulation were found at the KGN implanted site. Vascularity as well as disorganization in collagen fibers were also present in the same site along with increased expression of the chondrocyte specific marker, collagen type II (Col. II). In vitro studies confirmed that KGN was released continuously from KGN-alginate in vivo beads and induced chondrogenic differentiation of tendon stem/progenitor cells (TSCs) suggesting that chondrogenesis after KGN-bead implantation into the rat tendons is likely due to the aberrant differentiation of TSCs into chondrocytes. Taken together, our results showed that KGN-alginate beads can be used to create a rat model of tendinopathy, which, at least in part, reproduces the features of over-use tendinopathy model created by long term treadmill running. This model is mechanistic (stem cell differentiation), highly reproducible and precise in creating localized tendinopathic lesions. It is expected that this model will be useful to evaluate the effects of various topical treatments such as NSAIDs and platelet-rich plasma (PRP) for the treatment of tendinopathy.

  7. Induced Seismicity

    Science.gov (United States)

    Keranen, Katie M.; Weingarten, Matthew

    2018-05-01

    The ability of fluid-generated subsurface stress changes to trigger earthquakes has long been recognized. However, the dramatic rise in the rate of human-induced earthquakes in the past decade has created abundant opportunities to study induced earthquakes and triggering processes. This review briefly summarizes early studies but focuses on results from induced earthquakes during the past 10 years related to fluid injection in petroleum fields. Study of these earthquakes has resulted in insights into physical processes and has identified knowledge gaps and future research directions. Induced earthquakes are challenging to identify using seismological methods, and faults and reefs strongly modulate spatial and temporal patterns of induced seismicity. However, the similarity of induced and natural seismicity provides an effective tool for studying earthquake processes. With continuing development of energy resources, increased interest in carbon sequestration, and construction of large dams, induced seismicity will continue to pose a hazard in coming years.

  8. MiR-125b Inhibits LPS-Induced Inflammatory Injury via Targeting MIP-1α in Chondrogenic Cell ATDC5

    Directory of Open Access Journals (Sweden)

    Jinling Jia

    2018-03-01

    Full Text Available Background/Aims: Chondrocyte apoptosis is largely responsible for cartilage degeneration in osteoarthritis (OA. MicroRNAs (miRNAs play an important role in chondrogenesis and cartilage remodeling. This study explored the effect of miR-125b on inflammatory injury in chondrogenic cells. Methods: LPS was used to simulate inflammatory injury in murine chondrogenic ATDC5 cell lines. Targeting effect of miR-125b on MIP-1α 3’UTR was assessed by dual luciferase activity assay. Regulatory effect of miR-125b on MIP-1α expression and the potential regulatory mechanism on inflammatory injury were assessed by Western blot. Results: miR-125b expression was decreased in LPS-induced ATDC5 cells and overexpression of miR-125b inhibited LPS-induced cell viability decline, the rise of apoptosis and inflammatory factors’ productions. MIP-1α expression was negatively related to miR-125b, and miR-125b directly targeted with 3’UTR of MIP-1α. Knockdown of miR-125b promoted LPS-induced inflammatory response via upregulation of MIP-1α. miR-125b expression in LPS-induced ATDC5 cells was negatively related with activations of NF-κB and JNK signaling pathways. Overexpression of miR-125b inhibited LPS-induced inflammation injury via suppressing MIP-1α expression and inhibiting activations of NF-κB and JNK signaling pathways. Conclusion: miR-125b could play an important role in inflammatory injury of chondrogenic cells and miR-125b affected inflammatory injury of ATDC5 cells via regulating expression of MIP-1α and regulating NF-κB and JNK signaling pathways.

  9. Pituitary Adenylate Cyclase Activating Polypeptide (PACAP) Pathway Is Induced by Mechanical Load and Reduces the Activity of Hedgehog Signaling in Chondrogenic Micromass Cell Cultures

    Science.gov (United States)

    Juhász, Tamás; Szentléleky, Eszter; Szűcs Somogyi, Csilla; Takács, Roland; Dobrosi, Nóra; Engler, Máté; Tamás, Andrea; Reglődi, Dóra; Zákány, Róza

    2015-01-01

    Pituitary adenylate cyclase activating polypeptide (PACAP) is a neurohormone exerting protective function during various stress conditions either in mature or developing tissues. Previously we proved the presence of PACAP signaling elements in chicken limb bud-derived chondrogenic cells in micromass cell cultures. Since no data can be found if PACAP signaling is playing any role during mechanical stress in any tissues, we aimed to investigate its contribution in mechanotransduction during chondrogenesis. Expressions of the mRNAs of PACAP and its major receptor, PAC1 increased, while that of other receptors, VPAC1, VPAC2 decreased upon mechanical stimulus. Mechanical load enhanced the expression of collagen type X, a marker of hypertrophic differentiation of chondrocytes and PACAP addition attenuated this elevation. Moreover, exogenous PACAP also prevented the mechanical load evoked activation of hedgehog signaling: protein levels of Sonic and Indian Hedgehogs and Gli1 transcription factor were lowered while expressions of Gli2 and Gli3 were elevated by PACAP application during mechanical load. Our results suggest that mechanical load activates PACAP signaling and exogenous PACAP acts against the hypertrophy inducing effect of mechanical load. PMID:26230691

  10. Pituitary Adenylate Cyclase Activating Polypeptide (PACAP Pathway Is Induced by Mechanical Load and Reduces the Activity of Hedgehog Signaling in Chondrogenic Micromass Cell Cultures

    Directory of Open Access Journals (Sweden)

    Tamás Juhász

    2015-07-01

    Full Text Available Pituitary adenylate cyclase activating polypeptide (PACAP is a neurohormone exerting protective function during various stress conditions either in mature or developing tissues. Previously we proved the presence of PACAP signaling elements in chicken limb bud-derived chondrogenic cells in micromass cell cultures. Since no data can be found if PACAP signaling is playing any role during mechanical stress in any tissues, we aimed to investigate its contribution in mechanotransduction during chondrogenesis. Expressions of the mRNAs of PACAP and its major receptor, PAC1 increased, while that of other receptors, VPAC1, VPAC2 decreased upon mechanical stimulus. Mechanical load enhanced the expression of collagen type X, a marker of hypertrophic differentiation of chondrocytes and PACAP addition attenuated this elevation. Moreover, exogenous PACAP also prevented the mechanical load evoked activation of hedgehog signaling: protein levels of Sonic and Indian Hedgehogs and Gli1 transcription factor were lowered while expressions of Gli2 and Gli3 were elevated by PACAP application during mechanical load. Our results suggest that mechanical load activates PACAP signaling and exogenous PACAP acts against the hypertrophy inducing effect of mechanical load.

  11. Effect of WNT5a on chondrogenesis and limb development

    Czech Academy of Sciences Publication Activity Database

    Killinger, Michael; Veselá, Iva; Buchtová, Marcela

    2015-01-01

    Roč. 159, Suppl 1 (2015), S17-S17 ISSN 1213-8118. [Morphology 2015. International Congress of the Czech Anatomical Society /49./. Lojda Symposium on Histochemistry /52./. 06.09.2015-08.09.2015, Olomouc] R&D Projects: GA ČR(CZ) GA14-31540S Institutional support: RVO:67985904 Keywords : limb development Subject RIV: EA - Cell Biology

  12. A transduced living hyaline cartilage graft releasing transgenic stromal cell-derived factor-1 inducing endogenous stem cell homing in vivo.

    Science.gov (United States)

    Zhang, Feng; Leong, Wenyan; Su, Kai; Fang, Yu; Wang, Dong-An

    2013-05-01

    Stromal cell-derived factor-1 (SDF-1), also known as a homing factor, is a potent chemokine that activates and directs mobilization, migration, and retention of certain cell species via systemic circulation. The responding homing cells largely consist of activated stem cells, so that, in case of tissue lesions, such SDF-1-induced cell migration may execute recruitment of endogenous stem cells to perform autoreparation and compensatory regeneration in situ. In this study, a recombinant adenoviral vector carrying SDF-1 transgene was constructed and applied to transduce a novel scaffold-free living hyaline cartilage graft (SDF-t-LhCG). As an engineered transgenic living tissue, SDF-t-LhCG is capable of continuously producing and releasing SDF-1 in vitro and in vivo. The in vitro trials were examined with ELISA, while the in vivo trials were subsequently performed via a subcutaneous implantation of SDF-t-LhCG in a nude mouse model, followed by series of biochemical and biological analyses. The results indicate that transgenic SDF-1 enhanced the presence of this chemokine in mouse's circulation system; in consequence, SDF-1-induced activation and recruitment of endogenous stem cells were also augmented in both peripheral blood and SDF-t-LhCG implant per se. These results were obtained via flow cytometry analyses on mouse blood samples and implanted SDF-t-LhCG samples, indicating an upregulation of the CXCR4(+)(SDF-1 receptor) cell population, accompanied by upregulation of the CD34(+), CD44(+), and Sca-1(+) cell populations as well as a downregulation of the CD11b(+) cell population. With the supply of SDF-1-recruited endogenous stem cells, enhanced chondrogenesis was observed in SDF-t-LhCG implants in situ.

  13. Inducing autophagy

    DEFF Research Database (Denmark)

    Harder, Lea M; Bunkenborg, Jakob; Andersen, Jens S.

    2014-01-01

    catabolism, which has recently been found to induce autophagy in an MTOR independent way and support cancer cell survival. In this study, quantitative phosphoproteomics was applied to investigate the initial signaling events linking ammonia to the induction of autophagy. The MTOR inhibitor rapamycin was used...... as a reference treatment to emphasize the differences between an MTOR-dependent and -independent autophagy-induction. By this means 5901 phosphosites were identified of which 626 were treatment-specific regulated and 175 were coregulated. Investigation of the ammonia-specific regulated sites supported that MTOR...

  14. TrxR2 deficiencies promote chondrogenic differentiation and induce apoptosis of chondrocytes through mitochondrial reactive oxygen species

    International Nuclear Information System (INIS)

    Yan, Jidong; Xu, Jing; Fei, Yao; Jiang, Congshan; Zhu, Wenhua; Han, Yan; Lu, Shemin

    2016-01-01

    Thioredoxin reductase 2 (TrxR2) is a selenium (Se) containing protein. Se deficiency is associated with an endemic osteoarthropathy characterized by impaired cartilage formation. It is unclear whether TrxR2 have roles in cartilage function. We examined the effects of TrxR2 on chondrogenic ATDC5 cells through shRNA-mediated gene silencing of TrxR2. We demonstrated TrxR2 deficiencies could enhance chondrogenic differentiation and apoptosis of ATDC5 cells. TrxR2 deficiencies increased accumulation of cartilage glycosaminoglycans (GAGs) and mineralization. TrxR2 deficiencies also stimulated expression of extracellular (ECM) gene including Collagen II and Aggrecan. The enhanced chondrogenic properties were further confirmed by activation of Akt signaling which are required for chondrogenesis. In addition, TrxR2 deficiencies promoted chondrocyte proliferation through acceleration of cell cycle progression by increase in both S and G2/M phase cell distribution accompanied with induction of parathyroid hormone-related protein (PTHrP). Moreover, TrxR2 deficiencies induced chondrocyte death via apoptosis and increased cell sensitivity to exogenous oxidative stress. Furthermore, TrxR2 deficiencies induced emission of mitochondrial reactive oxygen species (ROS) without alteration of mitochondrial membrane potential and intracellular ATP content. Finally, treatment of TrxR2 deficiency cells with N-acetylcysteine (NAC) inhibited mitochondrial ROS production and chondrocyte apoptosis. NAC also prevented chondrogenic differentiation of TrxR2 deficiency cells by suppression of ECM gene expression, GAGs accumulation and mineralization, as well as attenuation of Akt signaling. Thus, TrxR2-mediated mitochondrial integrity is indispensable for chondrogenic differentiation of ATDC5 cells. TrxR2 deficiency-induced impaired proliferation and death of chondrocytes may be the pathological mechanism of the osteoarthropathy due to Se deficiency. Notably, this study also uncover the roles of

  15. TrxR2 deficiencies promote chondrogenic differentiation and induce apoptosis of chondrocytes through mitochondrial reactive oxygen species

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Jidong [Department of Human Anatomy, Histology and Embryology, School of Basic Medical Sciences, Xi’an Jiaotong University Health Science Center, Xi’an, Shaanxi 710061 (China); Xu, Jing [Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Xi’an Jiaotong University Health Science Center, Xi’an, Shaanxi 710061 (China); Fei, Yao [College of Life Sciences, Northwest University, Xi’an, Shaanxi Province 710069 (China); Jiang, Congshan; Zhu, Wenhua; Han, Yan [Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Xi’an Jiaotong University Health Science Center, Xi’an, Shaanxi 710061 (China); Lu, Shemin, E-mail: lushemin@xjtu.edu.cn [Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Xi’an Jiaotong University Health Science Center, Xi’an, Shaanxi 710061 (China); Key Laboratory of Environment and Genes Related to Diseases, Xi’an Jiaotong University, Ministry of Education of China (China)

    2016-05-15

    Thioredoxin reductase 2 (TrxR2) is a selenium (Se) containing protein. Se deficiency is associated with an endemic osteoarthropathy characterized by impaired cartilage formation. It is unclear whether TrxR2 have roles in cartilage function. We examined the effects of TrxR2 on chondrogenic ATDC5 cells through shRNA-mediated gene silencing of TrxR2. We demonstrated TrxR2 deficiencies could enhance chondrogenic differentiation and apoptosis of ATDC5 cells. TrxR2 deficiencies increased accumulation of cartilage glycosaminoglycans (GAGs) and mineralization. TrxR2 deficiencies also stimulated expression of extracellular (ECM) gene including Collagen II and Aggrecan. The enhanced chondrogenic properties were further confirmed by activation of Akt signaling which are required for chondrogenesis. In addition, TrxR2 deficiencies promoted chondrocyte proliferation through acceleration of cell cycle progression by increase in both S and G2/M phase cell distribution accompanied with induction of parathyroid hormone-related protein (PTHrP). Moreover, TrxR2 deficiencies induced chondrocyte death via apoptosis and increased cell sensitivity to exogenous oxidative stress. Furthermore, TrxR2 deficiencies induced emission of mitochondrial reactive oxygen species (ROS) without alteration of mitochondrial membrane potential and intracellular ATP content. Finally, treatment of TrxR2 deficiency cells with N-acetylcysteine (NAC) inhibited mitochondrial ROS production and chondrocyte apoptosis. NAC also prevented chondrogenic differentiation of TrxR2 deficiency cells by suppression of ECM gene expression, GAGs accumulation and mineralization, as well as attenuation of Akt signaling. Thus, TrxR2-mediated mitochondrial integrity is indispensable for chondrogenic differentiation of ATDC5 cells. TrxR2 deficiency-induced impaired proliferation and death of chondrocytes may be the pathological mechanism of the osteoarthropathy due to Se deficiency. Notably, this study also uncover the roles of

  16. The trans-well coculture of human synovial mesenchymal stem cells with chondrocytes leads to self-organization, chondrogenic differentiation, and secretion of TGFβ

    DEFF Research Database (Denmark)

    Kubosch, Eva Johanna; Heidt, Emanuel; Bernstein, Anke

    2016-01-01

    BACKGROUND: Synovial mesenchymal stem cells (SMSC) possess a high chondrogenic differentiation potential, which possibly supports natural and surgically induced healing of cartilage lesions. We hypothesized enhanced chondrogenesis of SMSC caused by the vicinity of chondrocytes (CHDR). METHODS...

  17. Nfatc1 Is a Functional Transcriptional Factor Mediating Nell-1-Induced Runx3 Upregulation in Chondrocytes

    Directory of Open Access Journals (Sweden)

    Chenshuang Li

    2018-01-01

    Full Text Available Neural EGFL like 1 (Nell-1 is essential for chondrogenic differentiation, maturation, and regeneration. Our previous studies have demonstrated that Nell-1’s pro-chondrogenic activities are predominantly reliant upon runt-related transcription factor 3 (Runx3-mediated Indian hedgehog (Ihh signaling. Here, we identify the nuclear factor of activated T-cells 1 (Nfatc1 as the key transcriptional factor mediating the Nell-1 → Runx3 signal transduction in chondrocytes. Using chromatin immunoprecipitation assay, we were able to determine that Nfatc1 binds to the −833–−810 region of the Runx3-promoter in response to Nell-1 treatment. By revealing the Nell-1 → Nfatc1 → Runx3 → Ihh cascade, we demonstrate the involvement of Nfatc1, a nuclear factor of activated T-cells, in chondrogenesis, while providing innovative insights into developing a novel therapeutic strategy for cartilage regeneration and other chondrogenesis-related conditions.

  18. Transforming growth factor-beta messenger RNA and protein in murine colitis

    DEFF Research Database (Denmark)

    Whiting, C V; Williams, A M; Claesson, Mogens Helweg

    2001-01-01

    Using a CD4+ T-cell-transplanted SCID mouse model of colitis, we have analyzed TGF-beta transcription and translation in advanced disease. By in situ hybridization, the epithelium of both control and inflamed tissues transcribed TGF-beta1 and TGF-beta3 mRNAs, but both were expressed significantly...... farther along the crypt axis in disease. Control lamina propria cells transcribed little TGF-beta1 or TGF-beta3 mRNA, but in inflamed tissues many cells expressed mRNA for both isoforms. No TGF-beta2 message was detected in either control or inflamed tissues. Immunohistochemistry for latent and active TGF...

  19. Exercise-Induced Asthma

    Science.gov (United States)

    ... Videos for Educators Search English Español Exercise-Induced Asthma KidsHealth / For Parents / Exercise-Induced Asthma What's in ... Exercise-Induced Asthma Print What Is Exercise-Induced Asthma? Most kids and teens with asthma have symptoms ...

  20. PPAR-δ Agonist With Mesenchymal Stem Cells Induces Type II Collagen-Producing Chondrocytes in Human Arthritic Synovial Fluid.

    Science.gov (United States)

    Heck, Bruce E; Park, Joshua J; Makani, Vishruti; Kim, Eun-Cheol; Kim, Dong Hyun

    2017-08-01

    Osteoarthritis (OA) is an inflammatory joint disease characterized by degeneration of articular cartilage within synovial joints. An estimated 27 million Americans suffer from OA, and the population is expected to reach 67 million in the United States by 2030. Thus, it is urgent to find an effective treatment for OA. Traditional OA treatments have no disease-modifying effect, while regenerative OA therapies such as autologous chondrocyte implantation show some promise. Nonetheless, current regenerative therapies do not overcome synovial inflammation that suppresses the differentiation of mesenchymal stem cells (MSCs) to chondrocytes and the expression of type II collagen, the major constituent of functional cartilage. We discovered a synergistic combination that overcame synovial inflammation to form type II collagen-producing chondrocytes. The combination consists of peroxisome proliferator-activated receptor (PPAR) δ agonist, human bone marrow (hBM)-derived MSCs, and hyaluronic acid (HA) gel. Interestingly, those individual components showed their own strong enhancing effects on chondrogenesis. GW0742, a PPAR-δ agonist, greatly enhanced MSC chondrogenesis and the expression of type II collagen and glycosaminoglycan (GAG) in hBM-MSC-derived chondrocytes. GW0742 also increased the expression of transforming growth factor β that enhances chondrogenesis and suppresses cartilage fibrillation, ossification, and inflammation. HA gel also increased MSC chondrogenesis and GAG production. However, neither GW0742 nor HA gel could enhance the formation of type II collagen-producing chondrocytes from hBM-MSCs within human OA synovial fluid. Our data demonstrated that the combination of hBM-MSCs, PPAR-δ agonist, and HA gel significantly enhanced the formation of type II collagen-producing chondrocytes within OA synovial fluid from 3 different donors. In other words, the novel combination of PPAR-δ agonist, hBM-MSCs, and HA gel can overcome synovial inflammation to form

  1. Bone morphogenetic protein-2 functions as a negative regulator in the differentiation of myoblasts, but not as an inducer for the formations of cartilage and bone in mouse embryonic tongue

    Directory of Open Access Journals (Sweden)

    Suzuki Erika

    2011-07-01

    Full Text Available Abstract Background In vitro studies using the myogenic cell line C2C12 demonstrate that bone morphogenetic protein-2 (BMP-2 converts the developmental pathway of C2C12 from a myogenic cell lineage to an osteoblastic cell lineage. Further, in vivo studies using null mutation mice demonstrate that BMPs inhibit the specification of the developmental fate of myogenic progenitor cells. However, the roles of BMPs in the phases of differentiation and maturation in skeletal muscles have yet to be determined. The present study attempts to define the function of BMP-2 in the final stage of differentiation of mouse tongue myoblast. Results Recombinant BMP-2 inhibited the expressions of markers for the differentiation of skeletal muscle cells, such as myogenin, muscle creatine kinase (MCK, and fast myosin heavy chain (fMyHC, whereas BMP-2 siRNA stimulated such markers. Neither the recombinant BMP-2 nor BMP-2 siRNA altered the expressions of markers for the formation of cartilage and bone, such as osteocalcin, alkaline phosphatase (ALP, collagen II, and collagen X. Further, no formation of cartilage and bone was observed in the recombinant BMP-2-treated tongues based on Alizarin red and Alcian blue stainings. Neither recombinant BMP-2 nor BMP-2 siRNA affected the expression of inhibitor of DNA binding/differentiation 1 (Id1. The ratios of chondrogenic and osteogenic markers relative to glyceraldehyde-3-phosphate dehydrogenase (GAPDH, a house keeping gene were approximately 1000-fold lower than those of myogenic markers in the cultured tongue. Conclusions BMP-2 functions as a negative regulator for the final differentiation of tongue myoblasts, but not as an inducer for the formation of cartilage and bone in cultured tongue, probably because the genes related to myogenesis are in an activation mode, while the genes related to chondrogenesis and osteogenesis are in a silencing mode.

  2. Drug-induced thrombocytopenia

    DEFF Research Database (Denmark)

    Pedersen-Bjergaard, U; Andersen, M; Hansen, P B

    1997-01-01

    induced by non-cytotoxic drugs is characterised by heterogeneous clinical picture and recovery is generally rapid. Although corticosteroids seem inefficient, we still recommend that severe symptomatic cases of drug-induced thrombocytopenia are treated as idiopathic thrombocytopenic purpura due...

  3. Exercise-Induced Bronchoconstriction (EIB)

    Science.gov (United States)

    ... Conditions & Treatments ▸ Conditions Dictionary ▸ Exercise-Induced Bronchoconstriction Share | Exercise-Induced Bronchoconstriction (EIB) « Back to A to Z Listing Exercise-Induced Bronchoconstriction, (EIB), often known as exercise-induced ...

  4. Induced pluripotency with endogenous and inducible genes

    International Nuclear Information System (INIS)

    Duinsbergen, Dirk; Eriksson, Malin; Hoen, Peter A.C. 't; Frisen, Jonas; Mikkers, Harald

    2008-01-01

    The recent discovery that two partly overlapping sets of four genes induce nuclear reprogramming of mouse and even human cells has opened up new possibilities for cell replacement therapies. Although the combination of genes that induce pluripotency differs to some extent, Oct4 and Sox2 appear to be a prerequisite. The introduction of four genes, several of which been linked with cancer, using retroviral approaches is however unlikely to be suitable for future clinical applications. Towards developing a safer reprogramming protocol, we investigated whether cell types that express one of the most critical reprogramming genes endogenously are predisposed to reprogramming. We show here that three of the original four pluripotency transcription factors (Oct4, Klf4 and c-Myc or MYCER TAM ) induced reprogramming of mouse neural stem (NS) cells exploiting endogenous SoxB1 protein levels in these cells. The reprogrammed neural stem cells differentiated into cells of each germ layer in vitro and in vivo, and contributed to mouse development in vivo. Thus a combinatorial approach taking advantage of endogenously expressed genes and inducible transgenes may contribute to the development of improved reprogramming protocols

  5. Diet induced thermogenesis

    Directory of Open Access Journals (Sweden)

    Westerterp KR

    2004-08-01

    Full Text Available Objective Daily energy expenditure consists of three components: basal metabolic rate, diet-induced thermogenesis and the energy cost of physical activity. Here, data on diet-induced thermogenesis are reviewed in relation to measuring conditions and characteristics of the diet. Methods Measuring conditions include nutritional status of the subject, physical activity and duration of the observation. Diet characteristics are energy content and macronutrient composition. Results Most studies measure diet-induced thermogenesis as the increase in energy expenditure above basal metabolic rate. Generally, the hierarchy in macronutrient oxidation in the postprandial state is reflected similarly in diet-induced thermogenesis, with the sequence alcohol, protein, carbohydrate, and fat. A mixed diet consumed at energy balance results in a diet induced energy expenditure of 5 to 15 % of daily energy expenditure. Values are higher at a relatively high protein and alcohol consumption and lower at a high fat consumption. Protein induced thermogenesis has an important effect on satiety. In conclusion, the main determinants of diet-induced thermogenesis are the energy content and the protein- and alcohol fraction of the diet. Protein plays a key role in body weight regulation through satiety related to diet-induced thermogenesis.

  6. Induced quantum conformal gravity

    International Nuclear Information System (INIS)

    Novozhilov, Y.V.; Vassilevich, D.V.

    1988-11-01

    Quantum gravity is considered as induced by matter degrees of freedom and related to the symmetry breakdown in the low energy region of a non-Abelian gauge theory of fundamental fields. An effective action for quantum conformal gravity is derived where both the gravitational constant and conformal kinetic term are positive. Relation with induced classical gravity is established. (author). 15 refs

  7. Induced radioactivity at CERN

    CERN Multimedia

    1970-01-01

    A description of some of the problems and some of the advantages associated with the phenomenon of induced radioactivity at accelerator centres such as CERN. The author has worked in this field for several years and has recently written a book 'Induced Radioactivity' published by North-Holland.

  8. Diet induced thermogenesis

    NARCIS (Netherlands)

    Westerterp, K.R.

    2004-01-01

    OBJECTIVE: Daily energy expenditure consists of three components: basal metabolic rate, diet-induced thermogenesis and the energy cost of physical activity. Here, data on diet-induced thermogenesis are reviewed in relation to measuring conditions and characteristics of the diet. METHODS: Measuring

  9. Bleomycin-induced pneumonitis

    NARCIS (Netherlands)

    S. Sleijfer (Stefan)

    2001-01-01

    textabstractThe cytotoxic agent bleomycin is feared for its induction of sometimes fatal pulmonary toxicity, also known as bleomycin-induced pneumonitis (BIP). The central event in the development of BIP is endothelial damage of the lung vasculature due to bleomycin-induced

  10. Induced abortion in Taiwan.

    Science.gov (United States)

    Wang, P D; Lin, R S

    1995-04-01

    Induced abortion is widely practised in Taiwan; however, it had been illegal until 1985. It was of interest to investigate induced abortion practices in Taiwan after its legalization in 1985 in order to calculate the prevalence rate and ratio of induced abortion to live births and to pregnancies in Taiwan. A study using questionnaires through personal interviews was conducted on more than seventeen thousand women who attended a family planning service in Taipei metropolitan areas between 1991 and 1992. The reproductive history and sexual behaviour of the subjects were especially focused on during the interviews. Preliminary findings showed that 46% of the women had a history of having had an induced abortion. Among them, 54.8% had had one abortion, 29.7% had had two, and 15.5% had had three or more. The abortion ratio was 379 induced abortions per 1,000 live births and 255 per 1,000 pregnancies. The abortion ratio was highest for women younger than 20 years of age, for aboriginal women and for nulliparous women. When logistic regression was used to control for confounding variables, we found that the number of previous live births is the strongest predictor relating to women seeking induced abortion. In addition, a significant positive association exists between increasing number of induced abortions and cervical dysplasia.

  11. Photon induced reactions

    International Nuclear Information System (INIS)

    Mecking, B.A.

    1982-04-01

    Various aspects of medium energy nuclear reactions induced by real photons are reviewed. Special emphasis is put on high accuracy experiments that will become possible with the next generation of electron accelerators. (orig.)

  12. Induced Noise Control

    National Research Council Canada - National Science Library

    Maidanik, G

    2002-01-01

    The induced noise control parameter is defined in terms of the ratio of the stored energy in a master dynamic system, when it is coupled to an adjunct dynamic system, to that stored energy when the coupling is absent...

  13. Beam induced RF heating

    CERN Document Server

    Salvant, B; Arduini, G; Assmann, R; Baglin, V; Barnes, M J; Bartmann, W; Baudrenghien, P; Berrig, O; Bracco, C; Bravin, E; Bregliozzi, G; Bruce, R; Bertarelli, A; Carra, F; Cattenoz, G; Caspers, F; Claudet, S; Day, H; Garlasche, M; Gentini, L; Goddard, B; Grudiev, A; Henrist, B; Jones, R; Kononenko, O; Lanza, G; Lari, L; Mastoridis, T; Mertens, V; Métral, E; Mounet, N; Muller, J E; Nosych, A A; Nougaret, J L; Persichelli, S; Piguiet, A M; Redaelli, S; Roncarolo, F; Rumolo, G; Salvachua, B; Sapinski, M; Schmidt, R; Shaposhnikova, E; Tavian, L; Timmins, M; Uythoven, J; Vidal, A; Wenninger, J; Wollmann, D; Zerlauth, M

    2012-01-01

    After the 2011 run, actions were put in place during the 2011/2012 winter stop to limit beam induced radio frequency (RF) heating of LHC components. However, some components could not be changed during this short stop and continued to represent a limitation throughout 2012. In addition, the stored beam intensity increased in 2012 and the temperature of certain components became critical. In this contribution, the beam induced heating limitations for 2012 and the expected beam induced heating limitations for the restart after the Long Shutdown 1 (LS1) will be compiled. The expected consequences of running with 25 ns or 50 ns bunch spacing will be detailed, as well as the consequences of running with shorter bunch length. Finally, actions on hardware or beam parameters to monitor and mitigate the impact of beam induced heating to LHC operation after LS1 will be discussed.

  14. Vitiligo, drug induced (image)

    Science.gov (United States)

    ... this person's face have resulted from drug-induced vitiligo. Loss of melanin, the primary skin pigment, occasionally ... is the case with this individual. The typical vitiligo lesion is flat and depigmented, but maintains the ...

  15. Terahertz Induced Electromigration

    DEFF Research Database (Denmark)

    Strikwerda, Andrew; Zalkovskij, Maksim; Iwaszczuk, Krzysztof

    2014-01-01

    We report the first observation of THz-field-induced electromigration in subwavelength metallic gap structures after exposure to intense single-cycle, sub-picosecond electric field transients of amplitude up to 400 kV/cm.......We report the first observation of THz-field-induced electromigration in subwavelength metallic gap structures after exposure to intense single-cycle, sub-picosecond electric field transients of amplitude up to 400 kV/cm....

  16. Diet induced thermogenesis

    OpenAIRE

    Westerterp KR

    2004-01-01

    Objective Daily energy expenditure consists of three components: basal metabolic rate, diet-induced thermogenesis and the energy cost of physical activity. Here, data on diet-induced thermogenesis are reviewed in relation to measuring conditions and characteristics of the diet. Methods Measuring conditions include nutritional status of the subject, physical activity and duration of the observation. Diet characteristics are energy content and macronutrient composition. Resu...

  17. Laser-induced interactions

    International Nuclear Information System (INIS)

    Green, W.R.

    1979-01-01

    This dissertation discusses some of the new ways that lasers can be used to control the energy flow in a medium. Experimental and theoretical considerations of the laser-induced collision are discussed. The laser-induced collision is a process in which a laser is used to selectively transfer energy from a state in one atomic or molecular species to another state in a different species. The first experimental demonstration of this process is described, along with later experiments in which lasers were used to create collisional cross sections as large as 10 - 13 cm 2 . Laser-induced collisions utilizing both a dipole-dipole interaction and dipole-quadrupole interaction have been experimentally demonstrated. The theoretical aspects of other related processes such as laser-induced spin-exchange, collision induced Raman emission, and laser-induced charge transfer are discussed. Experimental systems that could be used to demonstrate these various processes are presented. An experiment which produced an inversion of the resonance line of an ion by optical pumping of the neutral atom is described. This type of scheme has been proposed as a possible method for constructing VUV and x-ray lasers

  18. Radiation-induced apoptosis

    International Nuclear Information System (INIS)

    Ohyama, Harumi

    1995-01-01

    Apoptosis is an active process of gene-directed cellular self-destruction that can be induced in many cell types via numerous physiological and pathological stimuli. We found that interphasedeath of thymocytes is a typical apoptosis showing the characteristic features of apoptosis including cell shrinkage, chromatin condensation and DNA degradation. Moderate dose of radiation induces extensive apoptosis in rapidly proliferating cell population such as the epithelium of intestinal crypt. Recent reports indicate that the ultimate form of radiation-induced mitotic death in several cells is also apoptosis. One of the hallmarks of apoptosis is the enzymatic internucleosomal degradation of chromatin DNA. We identified an endonuclease responsible for the radiation-induced DNA degradation in rat thymocytes. The death-sparing effects of interrupting RNA and protein synthesis suggested a cell genetic program for apoptosis. Apoptosis of thymocytes initiated by DNA damage, such as radiation and radio mimetic substance, absolutely requires the protein of p53 cancer suppresser gene. The cell death induced by glucocorticoid, or aging, has no such requirement. Expression of oncogene bcl-2 rescues cells from the apoptosis. Massive apoptosis in radiosensitive cells induced by higher dose radiation may be fatal. It is suggested that selective apoptotic elimination of cells would play an important role for protection against carcinogenesis and malformation through removal of cells with unrepaired radiation-induced DNA damages. Data to evaluate the significance of apoptosis in the radiation risk are still poor. Further research should be done in order to clarify the roles of the cell death on the acute and late effects of irradiation. (author)

  19. Chemical-induced Vitiligo

    Science.gov (United States)

    Harris, John E.

    2016-01-01

    Synopsis Chemical-induced depigmentation of the skin has been recognized for over 75 years, first as an occupational hazard but then extending to those using household commercial products as common as hair dyes. Since their discovery, these chemicals have been used therapeutically in patients with severe vitiligo to depigment their remaining skin and improve their appearance. The importance of recognizing this phenomenon was highlighted during an outbreak of vitiligo in Japan during the summer of 2013, when over 16,000 users of a new skin lightening cosmetic cream developed skin depigmentation at the site of contact with the cream and many in remote areas as well. Depigmenting chemicals appear to be analogs of the amino acid tyrosine that disrupt melanogenesis and result in autoimmunity and melanocyte destruction. Because chemical-induced depigmentation is clinically and histologically indistinguishable from non-chemically induced vitiligo, and because these chemicals appear to induce melanocyte autoimmunity, this phenomenon should be known as “chemical-induced vitiligo”, rather than less accurate terms that have been previously used. PMID:28317525

  20. New chondrosarcoma cell lines and mouse models to study the link between chondrogenesis and chemoresistance.

    Science.gov (United States)

    Monderer, David; Luseau, Alexandrine; Bellec, Amélie; David, Emmanuelle; Ponsolle, Stéphanie; Saiagh, Soraya; Bercegeay, Sylvain; Piloquet, Philippe; Denis, Marc G; Lodé, Laurence; Rédini, Françoise; Biger, Marine; Heymann, Dominique; Heymann, Marie-Françoise; Le Bot, Ronan; Gouin, François; Blanchard, Frédéric

    2013-10-01

    Chondrosarcomas are cartilage-forming, poorly vascularized tumors. They represent the second malignant primary bone tumor of adults after osteosarcoma, but in contrast to osteosarcoma they are resistant to chemotherapy and radiotherapy, surgical excision remaining the only therapeutic option. Few cell lines and animal models are available, and the mechanisms behind their chemoresistance remain largely unknown. Our goal was to establish new cell lines and animal cancer models from human chondrosarcoma biopsies to study their chemoresistance. Between 2007 and 2012, 10 chondrosarcoma biopsies were collected and used for cell culture and transplantation into nude mice. Only one transplanted biopsy and one injected cell line has engrafted successfully leading to conventional central high-grade chondrosarcoma similar to the original biopsies. In culture, two new stable cell lines were obtained, one from a dedifferentiated and one from a grade III conventional central chondrosarcoma biopsy. Their genetic characterization revealed triploid karyotypes, mutations in IDH1, IDH2, and TP53, deletion in CDKN2A and/or MDM2 amplification. These cell lines expressed mesenchymal membrane markers (CD44, 73, 90, 105) and were able to produce a hyaline cartilaginous matrix when cultured in chondrogenic three-dimensional (3D) pellets. Using a high-throughput quantitative RT-PCR approach, we observed that cell lines cultured in monolayer had lost expression of several genes implicated in cartilage development (COL2A1, COMP, ACAN) but restored their expression in 3D cultures. Chondrosarcoma cells in monolayer were sensitive to several conventional chemotherapeutic agents but became resistant to low doses of mafosfamide or doxorubicin when cultured in 3D pellets, in parallel with an altered nucleic accumulation of the drug. Our results indicate that the cartilaginous matrix produced by chondrosarcoma cells may impair diffusion of several drugs and thus contribute to chemoresistance. Therefore, 3D chondrogenic cell pellets constitute a more relevant model to study chondrosarcoma chemoresistance and may be a valuable alternative to animal experimentations.

  1. Catabolic factors and osteoarthritis-conditioned medium inhibit chondrogenesis of human mesenchymal stem cells.

    NARCIS (Netherlands)

    Heldens, G.T.H.; Blaney Davidson, E.N.; Vitters, E.L.; Schreurs, B.W.; Piek, E.; Berg, W.B. van den; Kraan, P.M. van der

    2012-01-01

    Articular cartilage has a very limited intrinsic repair capacity leading to progressive joint damage. Therapies involving tissue engineering depend on chondrogenic differentiation of progenitor cells. This chondrogenic differentiation will have to survive in a diseased joint. We postulate that

  2. Autologous chondrocytes as a novel source for neo-chondrogenesis in haemophiliacs.

    Science.gov (United States)

    Stocco, Elena; Barbon, Silvia; Radossi, Paolo; Rajendran, Senthilkumar; Dalzoppo, Daniele; Bortolami, Marina; Bagno, Andrea; Grandi, Francesca; Gamba, Pier Giorgio; Parnigotto, Pier Paolo; Tagariello, Giuseppe; Grandi, Claudio

    2016-10-01

    Haemophilic arthropathy is the major cause of disability in patients with haemophilia and, despite prophylaxis with coagulation factor concentrates, some patients still develop articular complications. We evaluate the feasibility of a tissue engineering approach to improve current clinical strategies for cartilage regeneration in haemophiliacs by using autologous chondrocytes (haemophilic chondrocytes; HaeCs). Little is known about articular chondrocytes from haemophilic patients and no characterisation has as yet been performed. An investigation into whether blood exposure alters HaeCs should be interesting from the perspective of autologous implants. The typical morphology and expression of specific target genes and surface markers were therefore assessed by optical microscopy, reverse transcription plus the polymerase chain reaction (PCR), real-time PCR and flow-cytometry. We then considered chondrocyte behaviour on a bio-hybrid scaffold (based on polyvinyl alcohol/Wharton's jelly) as an in vitro model of articular cartilage prosthesis. Articular chondrocytes from non-haemophilic donors were used as controls. HaeC morphology and the resulting immunophenotype CD44(+)/CD49c(+)/CD49e(+)/CD151(+)/CD73(+)/CD49f(-)/CD26(-) resembled those of healthy donors. Moreover, HaeCs were active in the transcription of genes involved in the synthesis of the extracellular matrix proteins of the articular cartilage (ACAN, COL1A, COL2A, COL10A, COL9A, COMP, HAS1, SOX9), although the over-expression of COL1A1, COL10A1, COMP and HAS was observed. In parallel, the composite scaffold showed adequate mechanical and biological properties for cartilage tissue engineering, promoting chondrocyte proliferation. Our preliminary evidence contributes to the characterisation of HaeCs, highlighting the opportunity of using them for autologous cartilage implants in patients with haemophilia.

  3. Effect of Dynamic Culture and Periodic Compression on Human Mesenchymal Stem Cell Proliferation and Chondrogenesis.

    Science.gov (United States)

    Guo, Ting; Yu, Li; Lim, Casey G; Goodley, Addison S; Xiao, Xuan; Placone, Jesse K; Ferlin, Kimberly M; Nguyen, Bao-Ngoc B; Hsieh, Adam H; Fisher, John P

    2016-07-01

    We have recently developed a bioreactor that can apply both shear and compressive forces to engineered tissues in dynamic culture. In our system, alginate hydrogel beads with encapsulated human mesenchymal stem cells (hMSCs) were cultured under different dynamic conditions while subjected to periodic, compressive force. A customized pressure sensor was developed to track the pressure fluctuations when shear forces and compressive forces were applied. Compared to static culture, dynamic culture can maintain a higher cell population throughout the study. With the application of only shear stress, qRT-PCR and immunohistochemistry revealed that hMSCs experienced less chondrogenic differentiation than the static group. The second study showed that chondrogenic differentiation was enhanced by additional mechanical compression. After 14 days, alcian blue staining showed more extracellular matrix formed in the compression group. The upregulation of the positive chondrogenic markers such as Sox 9, aggrecan, and type II collagen were demonstrated by qPCR. Our bioreactor provides a novel approach to apply mechanical forces to engineered cartilage. Results suggest that a combination of dynamic culture with proper mechanical stimulation may promote efficient progenitor cell expansion in vitro, thereby allowing the culture of clinically relevant articular chondrocytes for the treatment of articular cartilage defects.

  4. Wnt9a signaling is required for joint integrity and regulation of Ihh during chondrogenesis.

    Science.gov (United States)

    Später, Daniela; Hill, Theo P; O'sullivan, Roderick J; Gruber, Michaela; Conner, David A; Hartmann, Christine

    2006-08-01

    Joints, which separate skeleton elements, serve as important signaling centers that regulate the growth of adjacent cartilage elements by controlling proliferation and maturation of chondrocytes. Accurate chondrocyte maturation is crucial for endochondral ossification and for the ultimate size of skeletal elements, as premature or delayed maturation results predominantly in shortened elements. Wnt9a has previously been implicated as being a player in joint induction, based on gain-of function experiments in chicken and mouse. We show that loss of Wnt9a does not affect joint induction, but results to synovial chondroid metaplasia in some joints. This phenotype can be enhanced by removal of an additional Wnt gene, Wnt4, suggesting that Wnts are playing a crucial role in directing bi-potential chondro-synovioprogenitors to become synovial connective tissue, by actively suppressing their chondrogenic potential. Furthermore, we show that Wnt9a is a temporal and spatial regulator of Indian hedgehog (Ihh), a central player of skeletogenesis. Loss of Wnt9a activity results in transient downregulation of Ihh and reduced Ihh-signaling activity at E12.5-E13.5. The canonical Wnt/beta-catenin pathway probably mediates regulation of Ihh expression in prehypertrophic chondrocytes by Wnt9a, because embryos double-heterozygous for Wnt9a and beta-catenin show reduced Ihh expression, and in vivo chromatin immunoprecipitation demonstrates a direct interaction between the beta-catenin/Lef1 complex and the Ihh promoter.

  5. Enhanced chondrogenesis of human nasal septum derived progenitors on nanofibrous scaffolds

    Energy Technology Data Exchange (ETDEWEB)

    Shafiee, Abbas [Department of Tissue Engineering, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Stem Cell biology and Tissue Engineering Departments, Stem Cell Technology Research Center, Tehran (Iran, Islamic Republic of); Institute of Health and Biomedical Innovation, Queensland University of Technology (QUT), Brisbane, QLD (Australia); Seyedjafari, Ehsan [Department of Biotechnology, College of Science, University of Tehran, Tehran (Iran, Islamic Republic of); Sadat Taherzadeh, Elham [Stem Cell biology and Tissue Engineering Departments, Stem Cell Technology Research Center, Tehran (Iran, Islamic Republic of); Dinarvand, Peyman [Stem Cell biology and Tissue Engineering Departments, Stem Cell Technology Research Center, Tehran (Iran, Islamic Republic of); The Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, Saint Louis, MO (United States); Soleimani, Masoud [Hematology Department, Faculty of Medical Science, Tarbiat Modares University, Tehran (Iran, Islamic Republic of); Ai, Jafar, E-mail: jafar_ai@tums.ac.ir [Department of Tissue Engineering, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Brain and Spinal Injury Research Center, Imam Hospital, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of)

    2014-07-01

    Topographical cues can be exploited to regulate stem cell attachment, proliferation, differentiation and function in vitro and in vivo. In this study, we aimed to investigate the influence of different nanofibrous topographies on the chondrogenic differentiation potential of nasal septum derived progenitors (NSP) in vitro. Aligned and randomly oriented Ploy (L-lactide) (PLLA)/Polycaprolactone (PCL) hybrid scaffolds were fabricated via electrospinning. First, scaffolds were fully characterized, and then NSP were seeded on them to study their capacity to support stem cell attachment, proliferation and chondrogenic differentiation. Compared to randomly oriented nanofibers, aligned scaffolds showed a high degree of nanofiber alignment with much better tensile strength properties. Both scaffolds supported NSP adhesion, proliferation and chondrogenic differentiation. Despite the higher rate of cell proliferation on random scaffolds, a better chondrogenic differentiation was observed on aligned nanofibers as deduced from higher expression of chondrogenic markers such as collagen type II and aggrecan on aligned scaffolds. These findings demonstrate that electrospun constructs maintain NSP proliferation and differentiation, and that the aligned nanofibrous scaffolds can significantly enhance chondrogenic differentiation of nasal septum derived progenitors. - Highlights: • Electrospun nanofiber scaffolds with different topographies were fabricated. • Aligned nanofiber scaffolds had better tensile strength properties. • Nasal septum derived progenitors were cultured on nanofibrous scaffolds. • Both topographies support proliferation and chondrogenic differentiation. • Better chondrogenic differentiation was observed on aligned nanofibers.

  6. The initial bearing capacities of subchondral bone replacements considerably contributing to chondrogenesis

    Czech Academy of Sciences Publication Activity Database

    Petrtýl, M.; Danešová, J.; Lísal, J.; Šenolt, L.; Hulejová, H.; Polanská, M.; Bastl, Zdeněk; Kruliš, Zdeněk; Černý, P.

    2010-01-01

    Roč. 12, č. 3 (2010), s. 59-65 ISSN 1509-409X R&D Projects: GA ČR GA106/06/0761 Institutional research plan: CEZ:AV0Z40400503; CEZ:AV0Z40500505 Keywords : biomechanics * osteochondral defects * polymer replacement Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 0.432, year: 2010

  7. A combinatorial approach towards the design of nanofibrous scaffolds for chondrogenesis

    Science.gov (United States)

    Ahmed, Maqsood; Ramos, Tiago André Da Silva; Damanik, Febriyani; Quang Le, Bach; Wieringa, Paul; Bennink, Martin; van Blitterswijk, Clemens; de Boer, Jan; Moroni, Lorenzo

    2015-10-01

    The extracellular matrix (ECM) is a three-dimensional (3D) structure composed of proteinaceous fibres that provide physical and biological cues to direct cell behaviour. Here, we build a library of hybrid collagen-polymer fibrous scaffolds with nanoscale dimensions and screen them for their ability to grow chondrocytes for cartilage repair. Poly(lactic acid) and poly (lactic-co-glycolic acid) at two different monomer ratios (85:15 and 50:50) were incrementally blended with collagen. Physical properties (wettability and stiffness) of the scaffolds were characterized and related to biological performance (proliferation, ECM production, and gene expression) and structure-function relationships were developed. We found that soft scaffolds with an intermediate wettability composed of the highly biodegradable PLGA50:50 and collagen, in two ratios (40:60 and 60:40), were optimal for chondrogenic differentiation of ATDC5 cells as determined by increased ECM production and enhanced cartilage specific gene expression. Long-term cultures indicated a stable phenotype with minimal de-differentiation or hypertrophy. The combinatorial methodology applied herein is a promising approach for the design and development of scaffolds for regenerative medicine.

  8. Effect of Collagen Type I or Type II on Chondrogenesis by Cultured Human Articular Chondrocytes

    NARCIS (Netherlands)

    Rutgers, M.; Saris, Daniël B.F.; Vonk, L.A.; van Rijen, M.H.P.; Akrum, V.; Langeveld, D.; van Boxtel, A.; Dhert, W.J.A.; Creemers, L.B.

    2013-01-01

    Introduction: Current cartilage repair procedures using autologous chondrocytes rely on a variety of carriers for implantation. Collagen types I and II are frequently used and valuable properties of both were shown earlier in vitro, although a preference for either was not demonstrated. Recently,

  9. Sub-NOAEL amounts of vinclozolin and xenoestrogens target rat chondrogenesis in vivo.

    Science.gov (United States)

    Auxietre, Thuy-Anh; Dumontier, Marie-France; Balguy, Irene; Frapart, Yves; Canivenc-Lavier, Marie-Chantal; Berges, Raymond; Boudalia, Sofiane; Auger, Jacques; Corvol, Marie-Therese; Savouret, Jean-François

    2014-04-01

    Several endocrine disrupting compounds (EDC) elicit skeletal dysgenesis at pharmacological doses. We have investigated the impact of doses below the "No Observed Adverse Effect" (NOAEL) for vinclozolin (V), an anti-androgenic fungicide, alone or associated with xenoestrogens (Genistein, G and bisphenol-A, BPA). V, G, BPA and their combinations were administered orally to female Wistar rats during gestation and lactation. F1 and F2 offspring were investigated for skeletal anomalies at post-natal days 30, 110 (d30, d110). Skeletal development was monitored by measuring caudal vertebrae and long bones dimensions by X-ray micro-CT-scan. A significant increase in Inter Transverse Apophysis (ITA) distance at the upper head of caudal vertebrae, associated with a reduction in vertebral body height was observed in treated F1 females, but not males. Histometrical analysis of vertebral body growth plate cartilage was performed on serial sections of caudal vertebrae. F1 females but not males showed a diminution in growth plate thickness, with greater impact on the hypertrophic zone. All effects were maximal at d30. Effects on ITA width persisted until d110 while effects on growth plate disappeared. These effects were essentially vinclozolin or BPA-dependent. F2 animals were not affected. Our data suggest that vinclozolin and xenoestrogens act as cartilage developmental disruptors. We suggest that present NOAEL values for these compounds, and EDC at large, might be reconsidered using gestational exposure models. Finally, micro CT-scan appears a valuable non-invasive technique to detect EDC effects on live fauna. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  10. Collagen type II enhances chondrogenesis in adipose tissue-derived stem cells by affecting cell shape

    NARCIS (Netherlands)

    Lu, Z.; Doulabi, B.Z.; Huang, C.; Bank, R.A.; Helder, M.N.

    2010-01-01

    Ideally, biomaterials have inductive properties, favoring specific lineage differentiation. For chondrogenic induction, these properties have been attributed to collagen type II. However, the underlying mechanisms are largely unknown. This study aimed to investigate whether collagen type II favors

  11. Collagen Type II Enhances Chondrogenesis in Adipose Tissue-Derived Stem Cells by Affecting Cell Shape

    NARCIS (Netherlands)

    Lu, ZuFu; Doulabi, Behrouz Zandieh; Huang, ChunLing; Bank, Ruud A.; Helder, Marco N.

    Ideally, biomaterials have inductive properties, favoring specific lineage differentiation. For chondrogenic induction, these properties have been attributed to collagen type II. However, the underlying mechanisms are largely unknown. This study aimed to investigate whether collagen type II favors

  12. Enhanced chondrogenesis of human nasal septum derived progenitors on nanofibrous scaffolds

    International Nuclear Information System (INIS)

    Shafiee, Abbas; Seyedjafari, Ehsan; Sadat Taherzadeh, Elham; Dinarvand, Peyman; Soleimani, Masoud; Ai, Jafar

    2014-01-01

    Topographical cues can be exploited to regulate stem cell attachment, proliferation, differentiation and function in vitro and in vivo. In this study, we aimed to investigate the influence of different nanofibrous topographies on the chondrogenic differentiation potential of nasal septum derived progenitors (NSP) in vitro. Aligned and randomly oriented Ploy (L-lactide) (PLLA)/Polycaprolactone (PCL) hybrid scaffolds were fabricated via electrospinning. First, scaffolds were fully characterized, and then NSP were seeded on them to study their capacity to support stem cell attachment, proliferation and chondrogenic differentiation. Compared to randomly oriented nanofibers, aligned scaffolds showed a high degree of nanofiber alignment with much better tensile strength properties. Both scaffolds supported NSP adhesion, proliferation and chondrogenic differentiation. Despite the higher rate of cell proliferation on random scaffolds, a better chondrogenic differentiation was observed on aligned nanofibers as deduced from higher expression of chondrogenic markers such as collagen type II and aggrecan on aligned scaffolds. These findings demonstrate that electrospun constructs maintain NSP proliferation and differentiation, and that the aligned nanofibrous scaffolds can significantly enhance chondrogenic differentiation of nasal septum derived progenitors. - Highlights: • Electrospun nanofiber scaffolds with different topographies were fabricated. • Aligned nanofiber scaffolds had better tensile strength properties. • Nasal septum derived progenitors were cultured on nanofibrous scaffolds. • Both topographies support proliferation and chondrogenic differentiation. • Better chondrogenic differentiation was observed on aligned nanofibers

  13. Chondrogenesis of adipose-derived adult stem cells in a poly-lactide-co-glycolide scaffold

    DEFF Research Database (Denmark)

    Mehlhorn, Alexander T; Zwingmann, Jorn; Finkenzeller, Guenter

    2009-01-01

    Adult adipose-derived stem cells (ASCs) are considered to be an alternative cell source for cell-based cartilage repair because of their multiple differentiation potentials. This article addresses the chondrogenic differentiation of ASCs seeded into poly-lactide-co-glycolide (PLGA) scaffolds after...

  14. [Drug induced diarrhea].

    Science.gov (United States)

    Morard, Isabelle; Hadengue, Antoine

    2008-09-03

    Diarrhea is a frequent adverse event involving the most frequently antibiotics, laxatives and NSAI. Drug induced diarrhea may be acute or chronic. It may be due to expected, dose dependant properties of the drug, to immuno-allergic or bio-genomic mechanisms. Several pathophysiological mechanisms have been described resulting in osmotic, secretory or inflammatory diarrhea, shortened transit time, or malabsorption. Histopathological lesions sometimes associated with drug induced diarrhea are usually non specific and include ulcerations, inflammatory or ischemic lesions, fibrous diaphragms, microscopic colitis and apoptosis. The diagnosis of drug induced diarrhea, sometimes difficult to assess, relies on the absence of other obvious causes and on the rapid disappearance of the symptoms after withdrawal of the suspected drug.

  15. Rosuvastatin-induced pemphigoid.

    LENUS (Irish Health Repository)

    Murad, Aizuri A

    2012-01-01

    Statins are widely prescribed medications and very well tolerated. Rosuvastatin is another member of this drug used to treat dyslipidaemia. It is a competitive inhibitor of the enzyme 3-hydroxy-3-methylglutaryl coenzyme A reductase. Immunobullous disease is usually idiopathic but can be drug-induced. Both idiopathic and iatrogenic forms share common clinical and immunohistological features. The authors report a case of pemphigoid induced by rosuvastatin, a commonly prescribed medication. To our knowledge, there is limited report on rosuvastatin associated with pemphigoid in the literature.

  16. Cervical osteophyte induced dysphagia

    International Nuclear Information System (INIS)

    Davies, R.P.; Sage, M.R.; Brophy, B.P.

    1989-01-01

    Although cervical spondylosis is a common disorder, dysphagia induced by osteophyte formation is uncommon. Fewer than one hundred cases of cervical osteophyte induced dysphagia have been reported, with little attention to the diagnosis by barium swallow. The radiological features of two cases treated surgically with good results are described. Both cases complained of dysphagia while one had associated respiratory obstruction on forward flexion of his neck. The features on barium study of cervical osteophytes causing dysphagia include deformity at the level of osteophyte formation, in both AP and lateral projections. Tracheal aspirations due to deformity at the laryngeal inlet and interference with epiglottic retroversion may be present. 8 refs., 3 figs

  17. Exercise-induced rhabdomyolysis.

    Science.gov (United States)

    Lee, George

    2014-11-03

    Exercise-induced rhabdomyolysis, or exertional rhabdomyolysis (ER), is a clinical entity typically considered when someone presents with muscle stiffness, swelling, and pain out of proportion to the expected fatigue post exercise. The diagnosis is confirmed by myoglobinuria, and an elevated serum Creatinine Phosphokinase (CPK) level, usually 10 times the normal range. However, an elevation in CPK is seen in most forms of strenuous exercise, up to 20 times the upper normal range. Therefore, there is no definitive pathologic CPK cut-off. Fortunately the dreaded complication of acute renal failure is rare compared to other forms rhabdomyolysis. We review the risks, diagnosis, clinical course and treatment for exercise- induced rhabdomyolysis.

  18. Migraine induced by hypoxia

    DEFF Research Database (Denmark)

    Arngrim, Nanna; Schytz, Henrik Winther; Britze, Josefine

    2016-01-01

    in the visual cortex were measured by proton magnetic resonance spectroscopy. The circumference of cranial arteries was measured by 3 T high-resolution magnetic resonance angiography. Hypoxia induced migraine-like attacks in eight patients compared to one patient after sham (P = 0.039), aura in three...... and possible aura in 4 of 15 patients. Hypoxia did not change glutamate concentration in the visual cortex compared to sham, but increased lactate concentration (P = 0.028) and circumference of the cranial arteries (P ... suggests that hypoxia may provoke migraine headache and aura symptoms in some patients. The mechanisms behind the migraine-inducing effect of hypoxia should be further investigated....

  19. Airbag induced corneal ectasia.

    Science.gov (United States)

    Mearza, Ali A; Koufaki, Fedra N; Aslanides, Ioannis M

    2008-02-01

    To report a case of airbag induced corneal ectasia. Case report. A patient 3 years post-LASIK developed bilateral corneal ectasia worse in the right eye following airbag deployment in a road traffic accident. At last follow up, best corrected vision was 20/40 with -4.00/-4.00 x 25 in the right eye and 20/25 with -1.25/-0.50 x 135 in the left eye. This is a rare presentation of trauma induced ectasia in a patient post-LASIK. It is possible that reduction in biomechanical integrity of the cornea from prior refractive surgery contributed to this presentation.

  20. Sleep-inducing factors.

    Science.gov (United States)

    García-García, Fabio; Acosta-Peña, Eva; Venebra-Muñoz, Arturo; Murillo-Rodríguez, Eric

    2009-08-01

    Kuniomi Ishimori and Henri Piéron were the first researchers to introduce the concept and experimental evidence for a chemical factor that would presumably accumulate in the brain during waking and eventually induce sleep. This substance was named hypnotoxin. Currently, the variety of substances which have been shown to alter sleep includes peptides, cytokines, neurotransmitters and some substances of lipidic nature, many of which are well known for their involvement in other biological activities. In this chapter, we describe the sleep-inducing properties of the vasoactive intestinal peptide, prolactin, adenosine and anandamide.

  1. Pressureless mechanical induction of stem cell differentiation is dose and frequency dependent.

    Directory of Open Access Journals (Sweden)

    Roland Fuhrer

    Full Text Available Movement is a key characteristic of higher organisms. During mammalian embryogenesis fetal movements have been found critical to normal tissue development. On the single cell level, however, our current understanding of stem cell differentiation concentrates on inducing factors through cytokine mediated biochemical signaling. In this study, human mesenchymal stem cells and chondrogenesis were investigated as representative examples. We show that pressureless, soft mechanical stimulation precipitated by the cyclic deformation of soft, magnetic hydrogel scaffolds with an external magnetic field, can induce chondrogenesis in mesenchymal stem cells without any additional chondrogenesis transcription factors (TGF-β1 and dexamethasone. A systematic study on the role of movement frequency revealed a classical dose-response relationship for human mesenchymal stem cells differentiation towards cartilage using mere mechanical stimulation. This effect could even be synergistically amplified when exogenous chondrogenic factors and movement were combined.

  2. Inducible laryngeal obstruction

    DEFF Research Database (Denmark)

    Halvorsen, Thomas; Walsted, Emil Schwarz; Bucca, Caterina

    2017-01-01

    Inducible laryngeal obstruction (ILO) describes an inappropriate, transient, reversible narrowing of the larynx in response to external triggers. ILO is an important cause of a variety of respiratory symptoms and can mimic asthma. Current understanding of ILO has been hampered by imprecise nomenc...

  3. Drug-induced apnea.

    Science.gov (United States)

    Boutroy, M J

    1994-01-01

    Drugs have been in the past and will in the future still be liable to induce apnea in neonates, infants and older children. At these different stages of development, the child may be abnormally vulnerable to respiratory disorders and apnea, and doses of drugs, without any abnormal side effects in adult patients, can be harmful in younger subjects. Drugs responsible for apnea during development are numerous, but more than half of the problems are induced by sedatives and hypnotics, among which phenothiazines, barbiturates, benzodiazepines (included transplacentally acquired) and general anesthetics are a few. Other pharmacological families are apnea inducers in the neonatal period and childhood: analgesics and opioid narcotics, agents acting at the levels of neuromuscular function and autonomic ganglia, and cardiovascular agents. The pathogenesis of these apneas depends on the disturbance of any mechanism responsible for the respiratory activity: medullary centers and brain stem structures, afferent influx to CNS, sleep stages, upper airways, lungs and respiratory muscles. At key stages such as birth and infancy, drugs may emphasize the particular sensitivity of the mechanisms responsible for inducing apnea. This might explain unexpected respiratory disorders during development.

  4. Metronidazole-Induced Pancreatitis

    Directory of Open Access Journals (Sweden)

    E. O'Halloran

    2010-01-01

    Conclusion. This case provides the eighth report of Metronidazole induced pancreatitis. All of the cases were reported in females and ran a benign course.Early diagnosis, discontinuation of the drug and supportive care will lead to a successful recovery in the majority of cases.

  5. XTC-induced hepatitis

    NARCIS (Netherlands)

    Oranje, W.A.; van Pol, V.; van der Wurff, A.A.; Zeijen, R.N.; Stockbrügger, R.W.; Arends, J.W.

    1994-01-01

    XTC-induced hepatitis. Oranje WA, von Pol P, vd Wurff A, Zeijen RN, Stockbrugger RW, Arends JW. Department of Internal Medicine, University Hospital, Maastricht, Netherlands. An increasing number of severe complications associated with the use of XTC is being reported. After 11 earlier case reports

  6. Bowthruster-induced damage

    NARCIS (Netherlands)

    Schokking, L.A.; Janssen, P.C.; Verhagen, H.J.

    2003-01-01

    The stability of stones in propeller-induced jet wash is still difficult to predict. Especially the trend of bowthrusters increasing in size and power in sea going ships (especially ferries) over the last years may be a reason for concern when dealing with the protection of slopes and beds. But also

  7. Muon-induced fission

    International Nuclear Information System (INIS)

    Polikanov, S.

    1980-01-01

    A review of recent experimental results on negative-muon-induced fission, both of 238 U and 232 Th, is given. Some conclusions drawn by the author are concerned with muonic atoms of fission fragments and muonic atoms of the shape isomer of 238 U. (author)

  8. Calotropis procera -induced keratitis

    Directory of Open Access Journals (Sweden)

    Pandey Nidhi

    2009-01-01

    Full Text Available Calotropis procera produces copious amounts of latex, which has been shown to possess several pharmacological properities. Its local application produces intense inflammatory response. In the 10 cases of Calotropis procera -induced keratitis reported here, the clinical picture showed corneal edema with striate keratopathy without any evidence of intraocular inflammation. The inflammation was reversed by the local application of steroid drops.

  9. Induced nuclear beta decay

    International Nuclear Information System (INIS)

    Reiss, H.R.

    1986-01-01

    Certain nuclear beta decay transitions normally inhibited by angular momentum or parity considerations can be induced to occur by the application of an electromagnetic field. Such decays can be useful in the controlled production of power, and in fission waste disposal

  10. Hyperthermia-induced apoptosis

    NARCIS (Netherlands)

    Nijhuis, E.H.A.

    2008-01-01

    This thesis describes a number of studies that investigated several aspects of heat-induced apoptosis in human lymphoid malignancies. Cells harbour both pro- and anti-apoptotic proteins and the balance between these proteins determines whether a cell is susceptible to undergo apoptosis. In this

  11. Drug induced aseptic meningitis

    African Journals Online (AJOL)

    PROF. EZECHUKWU

    2013-09-29

    Sep 29, 2013 ... Abstract. Drug-induced aseptic meningitis (DIAM) is a rare but important and often challenging diagnosis for the physician. Intake of antimicrobials, steroids, anal- gesics amongst others has been implicated. Signs and symptoms generally develop within 24-48 hours of drug ingestion. The pa- tient often ...

  12. Contrast induced nephropathy

    DEFF Research Database (Denmark)

    Stacul, Fulvio; van der Molen, Aart J; Reimer, Peter

    2011-01-01

    PURPOSE: The Contrast Media Safety Committee (CMSC) of the European Society of Urogenital Radiology (ESUR) has updated its 1999 guidelines on contrast medium-induced nephropathy (CIN). AREAS COVERED: Topics reviewed include the definition of CIN, the choice of contrast medium, the prophylactic me...

  13. Radiation-induced pneumothorax

    International Nuclear Information System (INIS)

    Epstein, D.M.; Littman, P.; Gefter, W.B.; Miller, W.T.; Raney, R.B. Jr.

    1983-01-01

    Pneumothorax is an uncommon complication of radiation therapy to the chest. The proposed pathogenesis is radiation-induced fibrosis promoting subpleural bleb formation that ruptures resulting in pneumothorax. We report on two young patients with primary sarcomas without pulmonary metastases who developed spontaneous pneumothorax after irradiation. Neither patient had antecedent radiographic evidence of pulmonary fibrosis

  14. Irradiation-Induced Nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Birtcher, R.C.; Ewing, R.C.; Matzke, Hj.; Meldrum, A.; Newcomer, P.P.; Wang, L.M.; Wang, S.X.; Weber, W.J.

    1999-08-09

    This paper summarizes the results of the studies of the irradiation-induced formation of nanostructures, where the injected interstitials from the source of irradiation are not major components of the nanophase. This phenomena has been observed by in situ transmission electron microscopy (TEM) in a number of intermetallic compounds and ceramics during high-energy electron or ion irradiations when the ions completely penetrate through the specimen. Beginning with single crystals, electron or ion irradiation in a certain temperature range may result in nanostructures composed of amorphous domains and nanocrystals with either the original composition and crystal structure or new nanophases formed by decomposition of the target material. The phenomenon has also been observed in natural materials which have suffered irradiation from the decay of constituent radioactive elements and in nuclear reactor fuels which have been irradiated by fission neutrons and other fission products. The mechanisms involved in the process of this nanophase formation are discussed in terms of the evolution of displacement cascades, radiation-induced defect accumulation, radiation-induced segregation and phase decomposition, as well as the competition between irradiation-induced amorphization and recrystallization.

  15. Lupus induced by medicaments

    International Nuclear Information System (INIS)

    Canas D, Carlos Alberto; Perafan B, Pablo Eduardo

    2001-01-01

    We describe a 55 years old female patient who consulted by fever syndrome, artralgias and the presence of high tittles positives antinuclear antibodies. She had arterial hypertension in treatment with captopril. We suspected the clinical diagnoses of drug-induced lupus; the withdraw of captopril was associated with the remission of the clinical and laboratory manifestations

  16. Glucocorticoid-induced hyperglycaemia

    NARCIS (Netherlands)

    Gerards, M.C.

    2018-01-01

    This thesis contains studies on current practice, clinical implications and treatment of excess glucocorticoid receptor (GCR) stimulation, with a focus on glucocorticoid-induced hyperglycaemia (GCIH). Chapter 1 is a general introduction to the glucocorticoid hormone. In chapter 2 , we have

  17. Understanding induced seismicity

    NARCIS (Netherlands)

    Elsworth, Derek; Spiers, Christopher J.|info:eu-repo/dai/nl/304829323; Niemeijer, Andre R.|info:eu-repo/dai/nl/370832132

    2016-01-01

    Fluid injection–induced seismicity has become increasingly widespread in oil- and gas-producing areas of the United States (1–3) and western Canada. It has shelved deep geothermal energy projects in Switzerland and the United States (4), and its effects are especially acute in Oklahoma, where

  18. Geomagnetism and Induced Voltage

    Science.gov (United States)

    Abdul-Razzaq, W.; Biller, R. D.

    2010-01-01

    Introductory physics laboratories have seen an influx of "conceptual integrated science" over time in their classrooms with elements of other sciences such as chemistry, biology, Earth science, and astronomy. We describe a laboratory to introduce this development, as it attracts attention to the voltage induced in the human brain as it…

  19. INDUCED ABORTION IN NIGERIA

    African Journals Online (AJOL)

    2014-06-01

    Jun 1, 2014 ... 95% of women would have had an induced abortion. (10), which ... who were fluent in both English and the local language were chosen ... the woman and society. The Muslims ... that “traditional methods are only effective at the early stages of ... modern and traditional family planning services. However ...

  20. Advertising-Induced Embarrassment

    NARCIS (Netherlands)

    Puntoni, S.; Hooge, de I.E.; Verbeke, W.J.M.I.

    2015-01-01

    Abstract Consumer embarrassment is a concern for many advertisers. Yet little is known about ad-induced embarrassment. The authors investigate when and why consumers experience embarrassment as a result of exposure to socially sensitive advertisements. The theory distinguishes between viewing

  1. Uterine contraction induced by Tanzanian plants used to induce abortion

    DEFF Research Database (Denmark)

    Nikolajsen, Tine; Nielsen, Frank; Rasch, Vibeke

    2011-01-01

    Women in Tanzania use plants to induce abortion. It is not known whether the plants have an effect.......Women in Tanzania use plants to induce abortion. It is not known whether the plants have an effect....

  2. [Hydroxyurea-induced pneumonia].

    Science.gov (United States)

    Girard, A; Ricordel, C; Poullot, E; Claeyssen, V; Decaux, O; Desrues, B; Delaval, P; Jouneau, S

    2014-05-01

    Hydroxyurea is an antimetabolite drug used in the treatment of myeloproliferative disorders. Common adverse effects include haematological, gastrointestinal cutaneous manifestations, and fever. Hydroxyurea-induced pneumonitis is unusual. A female patient was treated with hydroxyurea for polycythemia vera. She was admitted 20 days after commencing treatment with a high fever, productive cough, clear sputum and nausea. A chest CT-scan showed diffuse ground-glass opacities. Microbiological investigations were negative. The symptoms disappeared a few days after discontinuation of the drug and rechallenge led to a relapse of symptoms. Our case and 15 earlier cases of hydroxyurea-induced pneumonitis are reviewed. Two patterns of this disease may exist: an acute febrile form occurring within 1 month of introduction of hydroxyurea and a subacute form without fever. Even if uncommon, one should be aware of this complication of hydroxyurea. Copyright © 2013. Published by Elsevier Masson SAS.

  3. Hydroxychloroquine-induced erythroderma.

    Science.gov (United States)

    Pai, Sunil B; Sudershan, Bhuvaneshwari; Kuruvilla, Maria; Kamath, Ashwin; Suresh, Pooja K

    2017-01-01

    Erythroderma is characterized by diffuse erythema and scaling of the skin involving more than 90% of the total body skin surface area. Drug-induced erythroderma has rarely been reported with hydroxychloroquine. We report a case of a 50-year-old female patient, with systemic lupus erythematosus, who developed itchy lesions all over the body 1 month after starting treatment with hydroxychloroquine. Drug-induced erythroderma was suspected. Hydroxychloroquine was withdrawn and the patient was treated with emollients, mid-potency corticosteroids, and oral antihistamines. A biopsy was done which confirmed the diagnosis of erythroderma. She recovered with treatment and was discharged. A careful history and clinical examination to search for potential causative factors will help prevent disabling sequelae in erythroderma.

  4. Mild induced hypothermia

    DEFF Research Database (Denmark)

    Johansen, Maria E; Jensen, Jens-Ulrik; Bestle, Morten H

    2014-01-01

    INTRODUCTION: Coagulopathy associates with poor outcome in sepsis. Mild induced hypothermia has been proposed as treatment in sepsis but it is not known whether this intervention worsens functional coagulopathy. MATERIALS AND METHODS: Interim analysis data from an ongoing randomized controlled...... trial; The Cooling And Surviving Septic shock (CASS) study. Patients suffering severe sepsis/septic shock are allocated to either mild induced hypothermia (cooling to 32-34°C for 24hours) or control (uncontrolled temperature). TRIAL REGISTRATION: NCT01455116. Thrombelastography (TEG) is performed three....... At enrollment, 3%, 38%, and 59% had a hypocoagulable, normocoagulable, and hypercoagulable TEG clot strength (MA), respectively. In the hypothermia group, functional coagulopathy improved during the hypothermia phase, measured by R and MA, in patients with hypercoagulation as well as in patients...

  5. Time Domain Induced Polarization

    DEFF Research Database (Denmark)

    Fiandaca, Gianluca; Auken, Esben; Christiansen, Anders Vest

    2012-01-01

    Time-domain-induced polarization has significantly broadened its field of reference during the last decade, from mineral exploration to environmental geophysics, e.g., for clay and peat identification and landfill characterization. Though, insufficient modeling tools have hitherto limited the use...... of time-domaininduced polarization for wider purposes. For these reasons, a new forward code and inversion algorithm have been developed using the full-time decay of the induced polarization response, together with an accurate description of the transmitter waveform and of the receiver transfer function......, to reconstruct the distribution of the Cole-Cole parameters of the earth. The accurate modeling of the transmitter waveform had a strong influence on the forward response, and we showed that the difference between a solution using a step response and a solution using the accurate modeling often is above 100...

  6. Topiramate Induced Excessive Sialorrhea

    Directory of Open Access Journals (Sweden)

    Ersel Dag

    2015-11-01

    Full Text Available It is well-known that drugs such as clozapine and lithium can cause sialorrhea. On the other hand, topiramate has not been reported to induce sialorrhea. We report a case of a patient aged 26 who was given antiepileptic and antipsychotic drugs due to severe mental retardation and intractable epilepsy and developed excessive sialorrhea complaint after the addition of topiramate for the control of seizures. His complaints continued for 1,5 years and ended after giving up topiramate. We presented this case since it was a rare sialorrhea case induced by topiramate. Clinicians should be aware of the possibility of sialorrhea development which causes serious hygiene and social problems when they want to give topiramate to the patients using multiple drugs.

  7. Noise-Induced Hearing Loss

    Science.gov (United States)

    ... Home » Health Info » Hearing, Ear Infections, and Deafness Noise-Induced Hearing Loss On this page: What is ... I find additional information about NIHL? What is noise-induced hearing loss? Every day, we experience sound ...

  8. Induced quantum torsion

    International Nuclear Information System (INIS)

    Denardo, G.; Spallucci, E.

    1985-07-01

    We study pregeometry in the framework of a Poincare gauge field theory. The Riemann-Cartan space-time is shown to be an ''effective geometry'' for this model in the low energy limit. By using Heat Kernel techniques we find the induced action for curvature and torsion. We obtain in this way the usual Einstein-Hilbert action plus an axial Maxwell term describing the propagation of a massless, axial vector torsion field. (author)

  9. Cisplatin Induced Nephrotoxicity

    Directory of Open Access Journals (Sweden)

    Seyed Seifollah Beladi Mousavi

    2014-02-01

    The standard approach to prevent cisplatin-induced nephrotoxicity is the administration of lower doses of cisplatin in combination with the administration of full intravenous isotonic saline before and after cisplatin administration. Although a number of pharmacologic agents including sodium thiosulfate, N-acetylcysteine, theophylline and glycine have been evaluated for prevention of nephrotoxicity, none have proved to have an established role, thus, additional clinical studies will be required to confirm their probable effects.

  10. Amitriptyline induced cervical dystonia

    Directory of Open Access Journals (Sweden)

    Shivanand B Hiremath

    2016-01-01

    Full Text Available Tricyclic antidepressants (TCAs, such as amitriptyline, have many side effects. But extrapyramidal tract symptom is an uncommon side effect of these drugs. Here, we report a case of a 28-year-old male who is suffering from amitriptyline induced cervical dystonia. Though rare, this side effect is an uncomfortable condition and may influence drug compliance. So clinicians should be aware of this side effect while treating a patient with amitriptyline.

  11. Polycation induced actin bundles

    OpenAIRE

    Muhlrad, Andras; Grintsevich, Elena E.; Reisler, Emil

    2011-01-01

    Three polycations, polylysine, the polyamine spermine and the polycationic protein lysozyme were used to study the formation, structure, ionic strength sensitivity and dissociation of polycation-induced actin bundles. Bundles form fast, simultaneously with the polymerization of MgATP-G-actins, upon addition of polycations to solutions of actins at low ionic strength conditions. This indicates that nuclei and/or nascent filaments bundle due to attractive, electrostatic effect of polycations an...

  12. Induced current heating probe

    International Nuclear Information System (INIS)

    Thatcher, G.; Ferguson, B.G.; Winstanley, J.P.

    1984-01-01

    An induced current heating probe is of thimble form and has an outer conducting sheath and a water flooded flux-generating unit formed from a stack of ferrite rings coaxially disposed in the sheath. The energising coil is made of solid wire which connects at one end with a coaxial water current tube and at the other end with the sheath. The stack of ferrite rings may include non-magnetic insulating rings which help to shape the flux. (author)

  13. Induced QCD I: theory

    Energy Technology Data Exchange (ETDEWEB)

    Brandt, Bastian B. [Institute for Theoretical Physics, Goethe-University of Frankfurt,60438 Frankfurt (Germany); Institute for Theoretical Physics, University of Regensburg,93040 Regensburg (Germany); Lohmayer, Robert; Wettig, Tilo [Institute for Theoretical Physics, University of Regensburg,93040 Regensburg (Germany)

    2016-11-14

    We explore an alternative discretization of continuum SU(N{sub c}) Yang-Mills theory on a Euclidean spacetime lattice, originally introduced by Budzcies and Zirnbauer. In this discretization the self-interactions of the gauge field are induced by a path integral over N{sub b} auxiliary boson fields, which are coupled linearly to the gauge field. The main progress compared to earlier approaches is that N{sub b} can be as small as N{sub c}. In the present paper we (i) extend the proof that the continuum limit of the new discretization reproduces Yang-Mills theory in two dimensions from gauge group U(N{sub c}) to SU(N{sub c}), (ii) derive refined bounds on N{sub b} for non-integer values, and (iii) perform a perturbative calculation to match the bare parameter of the induced gauge theory to the standard lattice coupling. In follow-up papers we will present numerical evidence in support of the conjecture that the induced gauge theory reproduces Yang-Mills theory also in three and four dimensions, and explore the possibility to integrate out the gauge fields to arrive at a dual formulation of lattice QCD.

  14. Laser induced energy transfer

    International Nuclear Information System (INIS)

    Falcone, R.W.

    1979-01-01

    Two related methods of rapidly transferring stored energy from one excited chemical species to another are described. The first of these, called a laser induced collision, involves a reaction in which the energy balance is met by photons from an intense laser beam. A collision cross section of ca 10 - 17 cm 2 was induced in an experiment which demonstrated the predicted dependence of the cross section on wavelength and power density of the applied laser. A second type of laser induced energy transfer involves the inelastic scattering of laser radiation from energetically excited atoms, and subsequent absorption of the scattered light by a second species. The technique of producing the light, ''anti-Stokes Raman'' scattering of visible and infrared wavelength laser photons, is shown to be an efficient source of narrow bandwidth, high brightness, tunable radiation at vacuum ultraviolet wavelengths by using it to excite a rare gas transition at 583.7 A. In addition, this light source was used to make the first measurement of the isotopic shift of the helium metastable level at 601 A. Applications in laser controlled chemistry and spectroscopy, and proposals for new types of lasers using these two energy transfer methods are discussed

  15. Radiation-induced myelopathy

    Energy Technology Data Exchange (ETDEWEB)

    Gaenshirt, H [Heidelberg Univ. (F.R. Germany). Neurologische Klinik

    1975-10-01

    12 cases of radiation-induced myelopathy after /sup 60/Co teletherapy are reported on. Among these were 10 thoracal lesions, one cerviothoracal lesion, and one lesion of the medulla oblongata. In 9 cases, Hodgkin's disease had been the primary disease, tow patients had been irradiated because of suspected vertebral metastases of cancer of the breast, and one patient had suffered from a glomus tumour of the petrous bone. The spinal doses had exceeded the tolerance doses recommended in the relevant literature. There was no close correlation between the radiation dose and the course of the disease. The latency periods between the end of the radiotherapy and the onset of the neurological symptons varied from 6 to 16 mouths and were very constant in 7 cases with 6 to 9 months. The segmental height of the lesion corresponded to the level of irradiation. The presenting symptons of radiation-induced myelopathy are buruing dysaesthesias and Brown-Sequard's paralysis which may develop into transverse lesion of the cord with paraplegia still accompanied by dissociated perception disorders. The disease developed intermittently. Disturbances of the bladder function are frequent. The fluid is normal in most cases. Myelographic examinations were made in 8 cases. 3 cases developed into stationary cases exhibiting. Brown-Sequard syndrome, while 9 patients developed transverse lesion of the cord with paraplegia. 3 patients have died; antopsy findings are given for two of these. In the pathogenesis of radiation-induced myelopathy, the vascular factor is assumed to be of decisive importance.

  16. Baby universes with induced gravity

    International Nuclear Information System (INIS)

    Gao Yihong; Gao Hongbo

    1989-01-01

    In this paper some quantum effects of baby universes with induced gravity are discussed. It is proved that the interactions between the baby-parent universes are non-local, and argue that the induced low-energy cosmological constant is zero. This argument does not depend on the detail of the induced potential

  17. Polycation induced actin bundles.

    Science.gov (United States)

    Muhlrad, Andras; Grintsevich, Elena E; Reisler, Emil

    2011-04-01

    Three polycations, polylysine, the polyamine spermine and the polycationic protein lysozyme were used to study the formation, structure, ionic strength sensitivity and dissociation of polycation-induced actin bundles. Bundles form fast, simultaneously with the polymerization of MgATP-G-actins, upon the addition of polycations to solutions of actins at low ionic strength conditions. This indicates that nuclei and/or nascent filaments bundle due to attractive, electrostatic effect of polycations and the neutralization of repulsive interactions of negative charges on actin. The attractive forces between the filaments are strong, as shown by the low (in nanomolar range) critical concentration of their bundling at low ionic strength. These bundles are sensitive to ionic strength and disassemble partially in 100 mM NaCl, but both the dissociation and ionic strength sensitivity can be countered by higher polycation concentrations. Cys374 residues of actin monomers residing on neighboring filaments in the bundles can be cross-linked by the short span (5.4Å) MTS-1 (1,1-methanedyl bismethanethiosulfonate) cross-linker, which indicates a tight packing of filaments in the bundles. The interfilament cross-links, which connect monomers located on oppositely oriented filaments, prevent disassembly of bundles at high ionic strength. Cofilin and the polysaccharide polyanion heparin disassemble lysozyme induced actin bundles more effectively than the polylysine-induced bundles. The actin-lysozyme bundles are pathologically significant as both proteins are found in the pulmonary airways of cystic fibrosis patients. Their bundles contribute to the formation of viscous mucus, which is the main cause of breathing difficulties and eventual death in this disorder. Copyright © 2011 Elsevier B.V. All rights reserved.

  18. Induced mutations in citrus

    International Nuclear Information System (INIS)

    Spiegel-Roy, P.; Vardi, Aliza

    1990-01-01

    Full text: Parthenocarpic tendency is an important prerequisite for successful induction of seedlessness in breeding and especially in mutation breeding. A gene for asynapsis and accompanying seedless fruit has been found by us in inbred progeny of cv. 'Wilking'. Using budwood irradiation by gamma rays, seedless mutants of 'Eureka' and 'Villafranca' lemon (original clone of the latter has 25 seeds) and 'Minneola' tangelo have been obtained. Ovule sterility of the three mutants is nearly complete, with some pollen fertility still remaining. A semi-compact mutant of Shamouti orange has been obtained by irradiation. A programme for inducing seedlessness in easy peeling citrus varieties and selections has been initiated. (author)

  19. Shear-induced chaos

    International Nuclear Information System (INIS)

    Lin, Kevin K; Young, Lai-Sang

    2008-01-01

    Guided by a geometric understanding developed in earlier works of Wang and Young, we carry out numerical studies of shear-induced chaos in several parallel but different situations. The settings considered include periodic kicking of limit cycles, random kicks at Poisson times and continuous-time driving by white noise. The forcing of a quasi-periodic model describing two coupled oscillators is also investigated. In all cases, positive Lyapunov exponents are found in suitable parameter ranges when the forcing is suitably directed

  20. Shear-induced chaos

    Science.gov (United States)

    Lin, Kevin K.; Young, Lai-Sang

    2008-05-01

    Guided by a geometric understanding developed in earlier works of Wang and Young, we carry out numerical studies of shear-induced chaos in several parallel but different situations. The settings considered include periodic kicking of limit cycles, random kicks at Poisson times and continuous-time driving by white noise. The forcing of a quasi-periodic model describing two coupled oscillators is also investigated. In all cases, positive Lyapunov exponents are found in suitable parameter ranges when the forcing is suitably directed.

  1. Xerostomia induced by radiotherapy

    Directory of Open Access Journals (Sweden)

    Alimi D

    2015-08-01

    Full Text Available David Alimi Department of Anesthesiology, University of Pittsburgh Medical Center, Pittsburgh, PA, USAWe read with great interest the excellent review on xerostomia induced by radiotherapy, by Pinna et al.1 The authors should be congratulated for a very detailed review of the physiopathology, clinical symptoms, and therapeutic management of an extremely difficult condition. Although we agree that the use of anticholinergic medication represents treatment, it requires the patient to have residual salivary gland function. Unfortunately, it is well established that in most cases radiotherapy destroys most of the salivary gland and associated salivary secretions.     

  2. Cannabis induced asystole.

    Science.gov (United States)

    Brancheau, Daniel; Blanco, Jessica; Gholkar, Gunjan; Patel, Brijesh; Machado, Christian

    2016-01-01

    Cannabis or marijuana is the most used recreational, and until recently illegal, drug in the United States. Although cannabis has medicinal use, its consumption has been linked to motor vehicle accidents in dose dependent fashion. Marijuana and other cannabinoids produce a multitude of effects on the human body that may result in these motor vehicle accidents. Some of the effects that marijuana has been known to cause include altered sensorium, diminished reflexes, and increased vagal tone. We present a case of cannabis induced asystole from hypervagotonia. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Pacing-induced Cardiomyopathy

    Directory of Open Access Journals (Sweden)

    Alex Koo

    2017-10-01

    Full Text Available We present a case of pacing-induced cardiomyopathy. The patient presented with clinical symptoms of dyspnea, leg swelling, and orthopnea several months after a dual-chambered pacemaker was placed for third-degree heart block. The echocardiogram demonstrated a depressed ejection fraction. Coronary angiography was performed, which showed widely patent vessels. Single- and dual-chambered pacemakers create ventricular dyssynchrony, which in turn can cause structural, molecular changes leading to cardiomyopathy. With early intervention of biventricular pacemaker replacement, these changes can be reversible; thus, a timely diagnosis and awareness is warranted.

  4. Induced skeletal mutations

    International Nuclear Information System (INIS)

    Selby, P.B.

    1979-01-01

    This paper describes a large-scale experiment that, by means of breeding tests, confirmed that many dominant skeletal mutations are induced by large-dose radiation exposure. The author also discusses: (1) the major advantages and disadvantages of the skeletal method in improving estimates of genetic hazard to man; (2) future uses of the skeletal method; (3) direct estimation of risk beyond the first generation using the skeletal method; and (4) the possibility of using the skeletal method as a quick and easy screen for chemical mutagens

  5. Trauma Induced Coagulopathy

    DEFF Research Database (Denmark)

    Genét, Gustav Folmer; Johansson, Per; Meyer, Martin Abild Stengaard

    2013-01-01

    It remains debated whether traumatic brain injury (TBI) induces a different coagulopathy compared to non-TBI. This study investigated traditional coagulation tests, biomarkers of coagulopathy and endothelial damage in trauma patients with and without TBI. Blood from 80 adult trauma patients were...... sampled (median of 68 min (IQR 48-88) post-injury) upon admission to our trauma centre. Plasma/serum were retrospectively analysed for biomarkers reflecting sympathoadrenal activation (adrenaline, noradrenaline), coagulation activation/inhibition and fibrinolysis (protein C, activated protein C, tissue...

  6. Trastuzumab-induced cardiomyopathy.

    Science.gov (United States)

    Guglin, Maya; Cutro, Raymond; Mishkin, Joseph D

    2008-06-01

    Trastuzumab is a recombinant humanized monoclonal antibody used for the treatment of advanced breast cancer. It improves survival and increases response to chemotherapy. The major side effect of trastuzumab is cardiotoxicity manifesting as a reduction in left ventricular systolic function, either asymptomatic or with signs and symptoms of heart failure. Although reversible in most cases, cardiotoxicity frequently results in the discontinuation of trastuzumab. The objective of this review is to summarize facts about trastuzumab-induced cardiotoxicity and to highlight the areas of future investigations. We searched PubMed for trials involving trastuzumab used as an adjuvant therapy for breast cancer, including the metastatic breast cancer setting, and focused on cardiotoxicity.

  7. Docetaxel-induced neuropathy

    DEFF Research Database (Denmark)

    Eckhoff, Lise; Feddersen, Søren; Knoop, Ann

    2015-01-01

    Background. Docetaxel is a highly effective treatment of a wide range of malignancies but is often associated with peripheral neuropathy. The genetic variability of genes involved in the transportation or metabolism of docetaxel may be responsible for the variation in docetaxel-induced peripheral...... neuropathy (DIPN). The main purpose of this study was to investigate the impact of genetic variants in GSTP1 and ABCB1 on DIPN. Material and methods. DNA was extracted from whole blood from 150 patients with early-stage breast cancer who had received adjuvant docetaxel from February 2011 to May 2012. Two...

  8. Chemotherapy-induced polyneuropathy

    DEFF Research Database (Denmark)

    Zedan, Ahmed; Vilholm, Ole Jakob

    2014-01-01

    Chemotherapy-induced polyneuropathy (CIPN) is a common, but underestimated, clinical challenge. Incidence varies depending on many factors that are equally as important as the type of chemotherapeutic agent itself. Moreover, the assessment of CIPN is still uncertain, as several of the most...... frequently used scales do not rely on a formal neurological evaluation and depend on patients' reports and examiners' interpretations. Therefore, the aim of this MiniReview was to introduce the most common chemotherapies that cause neuropathy, and in addition to this, highlight the most significant...

  9. Contrast induced nephropathy

    DEFF Research Database (Denmark)

    Stacul, Fulvio; van der Molen, Aart J; Reimer, Peter

    2011-01-01

    PURPOSE: The Contrast Media Safety Committee (CMSC) of the European Society of Urogenital Radiology (ESUR) has updated its 1999 guidelines on contrast medium-induced nephropathy (CIN). AREAS COVERED: Topics reviewed include the definition of CIN, the choice of contrast medium, the prophylactic me....../min/1.73 m (2) is CIN risk threshold for intravenous contrast medium. • Hydration with either saline or sodium bicarbonate reduces CIN incidence. • Patients with eGFR = 60 ml/min/1.73 m (2) receiving contrast medium can continue metformin normally....

  10. Unphysiologically high magnesium concentrations support chondrocyte proliferation and redifferentiation.

    Science.gov (United States)

    Feyerabend, Frank; Witte, Frank; Kammal, Michael; Willumeit, Regine

    2006-12-01

    The effect of unphysiologically high extracellular magnesium concentrations on chondrocytes, induced by the supplementation of magnesium sulfate, was studied using a 3-phase tissue engineering model. The experiments showed that chondrocyte proliferation and redifferentiation, on the gene and protein expression level, are enhanced. A negative influence was found during chondrogenesis where an inhibition of extracellular matrix formation was observed. In addition, a direct impact on chondrocyte metabolism, elevated magnesium concentrations also affected growth factor effectiveness by consecutive influences during chondrogenesis. All observations were dosage dependent. The results of this study indicate that magnesium may be a useful tool for cartilage tissue engineering.

  11. Ion induced Auger spectroscopy

    International Nuclear Information System (INIS)

    Thomas, E.W.; Legg, K.O.; Metz, W.A.

    1980-01-01

    Auger electron spectra are induced by impact of heavy ions (e.g. Ar + ) on surfaces; it has been suggested that analysis of such spectra would be a useful technique for surface analysis. We have examined the Auger spectra for various projectile-target combinations and present as representative data the spectra for 100 keV Ar + impact on Al, Cr, Mn, Fe and Co. For a projectile incident on a species of higher nuclear charge the spectrum is dominated by Auger lines from the projectile, broadened considerably by the Doppler effect due to the projectile's motion. The spectra are not characteristic of the target and therefore offer no opportunity for surface analysis. For a projectile incident on a target of lower nuclear charge the spectrum is that of the target species but the spectrum is consistent with the source being sputtered excited atoms; the Auger electrons do not come from the surface. We conclude that the ion induced Auger spectra are in general not a convenient method for surface analysis. (orig.)

  12. Induced Seismicity Monitoring System

    Science.gov (United States)

    Taylor, S. R.; Jarpe, S.; Harben, P.

    2014-12-01

    There are many seismological aspects associated with monitoring of permanent storage of carbon dioxide (CO2) in geologic formations. Many of these include monitoring underground gas migration through detailed tomographic studies of rock properties, integrity of the cap rock and micro seismicity with time. These types of studies require expensive deployments of surface and borehole sensors in the vicinity of the CO2 injection wells. Another problem that may exist in CO2 sequestration fields is the potential for damaging induced seismicity associated with fluid injection into the geologic reservoir. Seismic hazard monitoring in CO2 sequestration fields requires a seismic network over a spatially larger region possibly having stations in remote settings. Expensive observatory-grade seismic systems are not necessary for seismic hazard deployments or small-scale tomographic studies. Hazard monitoring requires accurate location of induced seismicity to magnitude levels only slightly less than that which can be felt at the surface (e.g. magnitude 1), and the frequencies of interest for tomographic analysis are ~1 Hz and greater. We have developed a seismo/acoustic smart sensor system that can achieve the goals necessary for induced seismicity monitoring in CO2 sequestration fields. The unit is inexpensive, lightweight, easy to deploy, can operate remotely under harsh conditions and features 9 channels of recording (currently 3C 4.5 Hz geophone, MEMS accelerometer and microphone). An on-board processor allows for satellite transmission of parameter data to a processing center. Continuous or event-detected data is kept on two removable flash SD cards of up to 64+ Gbytes each. If available, data can be transmitted via cell phone modem or picked up via site visits. Low-power consumption allows for autonomous operation using only a 10 watt solar panel and a gel-cell battery. The system has been successfully tested for long-term (> 6 months) remote operations over a wide range

  13. Traffic forecasts ignoring induced demand

    DEFF Research Database (Denmark)

    Næss, Petter; Nicolaisen, Morten Skou; Strand, Arvid

    2012-01-01

    the model calculations included only a part of the induced traffic, the difference in cost-benefit results compared to the model excluding all induced traffic was substantial. The results show lower travel time savings, more adverse environmental impacts and a considerably lower benefitcost ratio when...... induced traffic is partly accounted for than when it is ignored. By exaggerating the economic benefits of road capacity increase and underestimating its negative effects, omission of induced traffic can result in over-allocation of public money on road construction and correspondingly less focus on other...... performance of a proposed road project in Copenhagen with and without short-term induced traffic included in the transport model. The available transport model was not able to include long-term induced traffic resulting from changes in land use and in the level of service of public transport. Even though...

  14. Paliperidone palmitate-induced sialorrhoea

    Directory of Open Access Journals (Sweden)

    Cengiz Cengisiz

    2016-03-01

    Full Text Available Extrapyramidal, metabolic, and cardiac side effects were reported for atypical antipsychotics; although a few resources show paliperidone-induced sialorrhea, there are no resources that show paliperidone palmitate-induced sialorrhea. In this paper, we present the paliperidone palmitate-induced sialorrhea side effects of a patient who applied on our clinic [Cukurova Med J 2016; 41(0.100: 8-13

  15. Radiation-induced cancer

    International Nuclear Information System (INIS)

    Dutrillaux, B.; CEA Fontenay-aux-Roses, 92

    1998-01-01

    The induction of malignant diseases is one of the most concerning late effects of ionising radiation. A large amount of information has been collected form atomic bomb survivors, patients after therapeutic irradiation, occupational follow-up and accidentally exposed populations. Major uncertainties persist in the (very) low range i.e, population and workers radioprotection. A review of the biological mechanisms leading to cancer strongly suggests that the vast majority of radiation-induced malignancies arise as a consequence of recessive mutations can be unveiled by ageing, this process being possibly furthered by constitutional or acquired genomic instability. The individual risk is likely to be very low, probably because of the usual dose level. However, the magnitude of medical exposure and the reliance of our societies on nuclear industry are so high that irreproachable decision-making processes and standards for practice are inescapable. (author)

  16. Radiation-induced nondisjunction

    International Nuclear Information System (INIS)

    Uchida, I.A.

    1979-01-01

    The methodology and results of epidemiological studies of the effects of preconception diagnostic x-rays of the abdomen on chromosome segregation in humans are described. The vast majority of studies show the same positive, though not significant, trend to increased nondisjunction among the offspring of irradiated women. The results of the various studies, however, cannot be pooled because of differing methodologies used. Abnormal chromosome segregation during mitotic division has been inducted experimentally by the in vitro exposure of human lymphocytes to a low dose of 50 R gamma irradiation. First meiotic nondisjunction has been successfully induced by whole body exposure of female mice to a low dose of radiation. The question of time-related repair of the mechanism involved in chromosome segregation is raised

  17. Radiation induced oral mucositis

    Directory of Open Access Journals (Sweden)

    P S Satheesh Kumar

    2009-01-01

    Full Text Available Patients receiving radiotherapy or chemotherapy will receive some degree of oral mucositis The incidence of oral mucositis was especially high in patients: (i With primary tumors in the oral cavity, oropharynx, or nasopharynx; (ii who also received concomitant chemotherapy; (iii who received a total dose over 5,000 cGy; and (iv who were treated with altered fractionation radiation schedules. Radiation-induced oral mucositis affects the quality of life of the patients and the family concerned. The present day management of oral mucositis is mostly palliative and or supportive care. The newer guidelines are suggesting Palifermin, which is the first active mucositis drug as well as Amifostine, for radiation protection and cryotherapy. The current management should focus more on palliative measures, such as pain management, nutritional support, and maintenance, of good oral hygiene

  18. Laser induced nuclear reactions

    International Nuclear Information System (INIS)

    Ledingham, Ken; McCanny, Tom; Graham, Paul; Fang Xiao; Singhal, Ravi; Magill, Joe; Creswell, Alan; Sanderson, David; Allott, Ric; Neely, David; Norreys, Peter; Santala, Marko; Zepf, Matthew; Watts, Ian; Clark, Eugene; Krushelnick, Karl; Tatarakis, Michael; Dangor, Bucker; Machecek, Antonin; Wark, Justin

    1998-01-01

    Dramatic improvements in laser technology since 1984 have revolutionised high power laser technology. Application of chirped-pulse amplification techniques has resulted in laser intensities in excess of 10 19 W/cm 2 . In the mid to late eighties, C. K. Rhodes and K. Boyer discussed the possibility of shining laser light of this intensity onto solid surfaces and to cause nuclear transitions. In particular, irradiation of a uranium target could induce electro- and photofission in the focal region of the laser. In this paper it is shown that μCi of 62 Cu can be generated via the (γ,n) reaction by a laser with an intensity of about 10 19 Wcm -2

  19. Radiation induced pesticidal microbes

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ki Yup; Lee, Y. K.; Kim, J. S.; Kim, J. K.; Lee, S. J.; Lim, D. S

    2001-01-01

    To isolate pesticidal microbes against plant pathogenic fungi, 4 strains of bacteria(K1. K3, K4, YS1) were isolated from mushroom compost and hot spring. K4, K1, K3, YS1 strain showed wide antifungal spectrum and high antifungal activities against 12 kinds of fungi. Specific proteins and the specific transcribed genes were found from the YS1 and its radiation-induced mutants. And knock-out mutants of antifungal activity were derived by transposon mutagenesis. From these knock-out mutants, the antifungal activity related genes and its modification by gamma-ray radiation are going to be studied. These results suggested that radiation could be an useful tool for the induction of functional mutants.

  20. Radiation induced microbial pesticide

    International Nuclear Information System (INIS)

    Kim, Ki Yup; Lee, Young Keun; Kim, Jae Sung; Kim, Jin Kyu; Lee, Sang Jae

    2000-01-01

    To control plant pathogenic fungi, 4 strains of bacteria (K1, K3, K4, YS1) were isolated from mushroom compost and hot spring. K4, K1, K3, YS1 strain showed wide antifungal spectrum and high antifungal activities against 13 kinds of fungi. Mutants of K1 and YS1 strains were induced by gamma-ray radiation and showed promising antifungal activities. These wild type and mutants showed resistant against more than 27 kinds of commercial pesticides among 30 kinds of commercial pesticides test particularly, YS1-1006 mutant strain showed resistant against hydrogen oxide. And mutants had increased antifungal activity against Botryoshaeria dothidea. These results suggested that radiation could be an useful method for the induction of functional mutants. (author)

  1. Aripiprazole-induced priapism

    Directory of Open Access Journals (Sweden)

    Satya K Trivedi

    2016-01-01

    Full Text Available Priapism is a urologic emergency representing a true disorder of penile erection that persists beyond or is unrelated to sexual interest or stimulation. A variety of psychotropic drugs are known to produce priapism, albeit rarely, through their antagonistic action on alpha-1 adrenergic receptors. We report such a case of priapism induced by a single oral dose of 10 mg aripiprazole, a drug with the least affinity to adrenergic receptors among all atypical antipsychotics. Polymorphism of alpha-2A adrenergic receptor gene in schizophrenia patients is known to be associated with sialorrhea while on clozapine treatment. Probably, similar polymorphism of alpha-1 adrenergic receptor gene could contribute to its altered sensitivity and resultant priapism. In future, pharmacogenomics-based approach may help in personalizing the treatment and effectively prevent the emergence of such side effects.

  2. [Cannabis-induced disorders].

    Science.gov (United States)

    Soyka, M; Preuss, U; Hoch, E

    2017-03-01

    Use and misuse of cannabis and marihuana are frequent. About 5% of the adult population are current users but only 1.2% are dependent. The medical use of cannabis is controversial but there is some evidence for improvement of chronic pain and spasticity. The somatic toxicity of cannabis is well proven but limited and psychiatric disorders induced by cannabis are of more relevance, e.g. cognitive disorders, amotivational syndrome, psychoses and delusional disorders as well as physical and psychological dependence. The withdrawal symptoms are usually mild and do not require pharmacological interventions. To date there is no established pharmacotherapy for relapse prevention. Psychosocial interventions include psychoeducation, behavioral therapy and motivational enhancement. The CANDIS protocol is the best established German intervention among abstinence-oriented therapies.

  3. Induced seismicity. Final report

    International Nuclear Information System (INIS)

    Segall, P.

    1997-01-01

    The objective of this project has been to develop a fundamental understanding of seismicity associated with energy production. Earthquakes are known to be associated with oil, gas, and geothermal energy production. The intent is to develop physical models that predict when seismicity is likely to occur, and to determine to what extent these earthquakes can be used to infer conditions within energy reservoirs. Early work focused on earthquakes induced by oil and gas extraction. Just completed research has addressed earthquakes within geothermal fields, such as The Geysers in northern California, as well as the interactions of dilatancy, friction, and shear heating, on the generation of earthquakes. The former has involved modeling thermo- and poro-elastic effects of geothermal production and water injection. Global Positioning System (GPS) receivers are used to measure deformation associated with geothermal activity, and these measurements along with seismic data are used to test and constrain thermo-mechanical models

  4. Macroscopic Optomechanically Induced Transparency

    Science.gov (United States)

    Pate, Jacob; Castelli, Alessandro; Martinez, Luis; Thompson, Johnathon; Chiao, Ray; Sharping, Jay

    Optomechanically induced transparency (OMIT) is an effect wherein the spectrum of a cavity resonance is modified through interference between coupled excitation pathways. In this work we investigate a macroscopic, 3D microwave, superconducting radio frequency (SRF) cavity incorporating a niobium-coated, silicon-nitride membrane as the flexible boundary. The boundary supports acoustic vibrational resonances, which lead to coupling with the microwave resonances of the SRF cavity. The theoretical development and physical understanding of OMIT for our macroscopic SRF cavity is the same as that for other recently-reported OMIT systems despite vastly different optomechanical coupling factors and device sizes. Our mechanical oscillator has a coupling factor of g0 = 2 π . 1 ×10-5 Hz and is roughly 38 mm in diameter. The Q = 5 ×107 for the SRF cavity allows probing of optomechanical effects in the resolved sideband regime.

  5. [Glucocorticoid induced osteoporosis].

    Science.gov (United States)

    Anić, Branimir; Mayer, Miroslav

    2014-01-01

    Secondary osteoporosis most often develops due to glucocorticoid therapy. Glucocorticoids affect all stages of the bone remodeling cycle, its formation and resorption. Osteoblasts are primarily affected, decreasing their activity and enhancing apoptosis. Patients treated with glucocorticoids have lower bone mineral density and increased fracture risk. Glucocorticoid-induced osteoporosis can be prevented by administering the minimal effective dose of glucocorticoids, calcium and vitamin D supplementation or, if possible, by hormone replace- ment therapy. Moreover, appropriate physical activity should be encouraged. Patients who are at higher risk for low-energy fractures (for example post-menopausal women) have to be actively treated, usually with antiresorptive drugs among which bisphosphonates are currently the first line therapy.

  6. Radiation induced genomic instability

    International Nuclear Information System (INIS)

    Morgan, W.

    2003-01-01

    This presentation will focus on delayed genetic effects occurring in the progeny of cells after exposure to ionizing radiation. We have developed a model system for investigating those genetic effects occurring multiple generations after radiation exposure. The presentation will describe some of the delayed effects observed after radiation exposures including delayed chromosomal rearrangements, and recombination events as determined by a plasmid based assay system. We will present new data on how changes in gene expression as measured by differential display and DNA microarray analysis provides a mechanism by which cells display a memory of irradiation, and introduce candidate genes that may play a role in initiating and perpetuation the unstable phenotype. These results will be discussed in terms of the recently described non-targeted Death Inducing Effect (DIE) where by secreted factors from clones of unstable cells can elicit effects in non irradiated cells and may serve to perpetuate the unstable phenotype in cells that themselves were not irradiated

  7. Radiation induced pesticidal microbes

    International Nuclear Information System (INIS)

    Kim, Ki Yup; Lee, Y. K.; Kim, J. S.; Kim, J. K.; Lee, S. J.; Lim, D. S.

    2001-01-01

    To isolate pesticidal microbes against plant pathogenic fungi, 4 strains of bacteria(K1. K3, K4, YS1) were isolated from mushroom compost and hot spring. K4, K1, K3, YS1 strain showed wide antifungal spectrum and high antifungal activities against 12 kinds of fungi. Specific proteins and the specific transcribed genes were found from the YS1 and its radiation-induced mutants. And knock-out mutants of antifungal activity were derived by transposon mutagenesis. From these knock-out mutants, the antifungal activity related genes and its modification by gamma-ray radiation are going to be studied. These results suggested that radiation could be an useful tool for the induction of functional mutants

  8. Alcohol-Induced Blackout

    Directory of Open Access Journals (Sweden)

    Dai Jin Kim

    2009-11-01

    Full Text Available For a long time, alcohol was thought to exert a general depressant effect on the central nervous system (CNS. However, currently the consensus is that specific regions of the brain are selectively vulnerable to the acute effects of alcohol. An alcohol-induced blackout is the classic example; the subject is temporarily unable to form new long-term memories while relatively maintaining other skills such as talking or even driving. A recent study showed that alcohol can cause retrograde memory impairment, that is, blackouts due to retrieval impairments as well as those due to deficits in encoding. Alcoholic blackouts may be complete (en bloc or partial (fragmentary depending on severity of memory impairment. In fragmentary blackouts, cueing often aids recall. Memory impairment during acute intoxication involves dysfunction of episodic memory, a type of memory encoded with spatial and social context. Recent studies have shown that there are multiple memory systems supported by discrete brain regions, and the acute effects of alcohol on learning and memory may result from alteration of the hippocampus and related structures on a cellular level. A rapid increase in blood alcohol concentration (BAC is most consistently associated with the likelihood of a blackout. However, not all subjects experience blackouts, implying that genetic factors play a role in determining CNS vulnerability to the effects of alcohol. This factor may predispose an individual to alcoholism, as altered memory function during intoxication may affect an individual‟s alcohol expectancy; one may perceive positive aspects of intoxication while unintentionally ignoring the negative aspects. Extensive research on memory and learning as well as findings related to the acute effects of alcohol on the brain may elucidate the mechanisms and impact associated with the alcohol- induced blackout.

  9. Flow-perfusion interferes with chondrogenic and hypertrophic matrix production by mesenchymal stem cells

    NARCIS (Netherlands)

    Kock, Linda M; Malda, Jos; Dhert, Wouter J A; Ito, Keita; Gawlitta, Debby

    2014-01-01

    Flow-perfusion is being promoted as a way to grow tissue-engineered cartilage in vitro. Yet, there is a concern that flow-perfusion may induce unwanted mechanical effects on chondrogenesis and terminal differentiation. Therefore, the aim of this study is to evaluate the effect of fluid flow on

  10. Temporal Transcriptome of Mouse ATDC5 Chondroprogenitors Differentiating under Hypoxic Conditions

    DEFF Research Database (Denmark)

    Chen, Li; Fink, Trine; Ebbesen, Peter

    2006-01-01

    The formation of cartilage takes place in vivo in an environment of reduced oxygen tension. To study the effect of hypoxia on the process of chondrogenesis, ATDC5 mouse chondroprogenitor cells were induced to differentiate by the addition of insulin and cultured under ambient and hypoxic conditions...

  11. Radiation induced nano structures

    International Nuclear Information System (INIS)

    Ibragimova, E.M.; Kalanov, M.U.; Khakimov, Z.

    2006-01-01

    Full text: Nanometer-size silicon clusters have been attracting much attention due to their technological importance, in particular, as promising building blocks for nano electronic and nano photonic systems. Particularly, silicon wires are of great of interest since they have potential for use in one-dimensional quantum wire high-speed field effect transistors and light-emitting devices with extremely low power consumption. Carbon and metal nano structures are studied very intensely due to wide possible applications. Radiation material sciences have been dealing with sub-micron objects for a long time. Under interaction of high energy particles and ionizing radiation with solids by elastic and inelastic mechanisms, at first point defects are created, then they form clusters, column defects, disordered regions (amorphous colloids) and finally precipitates of another crystal phase in the matrix. Such irradiation induced evolution of structure defects and phase transformations was observed by X-diffraction techniques in dielectric crystals of quartz and corundum, which exist in and crystal modifications. If there is no polymorphism, like in alkali halide crystals, then due to radiolysis halogen atoms are evaporated from the surface that results in non-stoichiometry or accumulated in the pores formed by metal vacancies in the sub-surface layer. Nano-pores are created by intensive high energy particles irradiation at first chaotically and then they are ordered and in part filled by inert gas. It is well-known mechanism of radiation induced swelling and embrittlement of metals and alloys, which is undesirable for construction materials for nuclear reactors. Possible solution of this problem may come from nano-structured materials, where there is neither swelling nor embrittlement at gas absorption due to very low density of the structure, while strength keeps high. This review considers experimental observations of radiation induced nano-inclusions in insulating

  12. Prolactin induces adrenal hypertrophy

    Directory of Open Access Journals (Sweden)

    E.J. Silva

    2004-02-01

    Full Text Available Although adrenocorticotropic hormone is generally considered to play a major role in the regulation of adrenal glucocorticoid secretion, several reports have suggested that other pituitary hormones (e.g., prolactin also play a significant role in the regulation of adrenal function. The aim of the present study was to measure the adrenocortical cell area and to determine the effects of the transition from the prepubertal to the postpubertal period on the hyperprolactinemic state induced by domperidone (4.0 mg kg-1 day-1, sc. In hyperprolactinemic adult and young rats, the adrenals were heavier, as determined at necropsy, than in the respective controls: adults (30 days: 0.16 ± 0.008 and 0.11 ± 0.007; 46 days: 0.17 ± 0.006 and 0.12 ± 0.008, and 61 days: 0.17 ± 0.008 and 0.10 ± 0.004 mg for treated and control animals, respectively; P < 0.05, and young rats (30 days: 0.19 ± 0.003 and 0.16 ± 0.007, and 60 days: 0.16 ± 0.006 and 0.13 ± 0.009 mg; P < 0.05. We selected randomly a circular area in which we counted the nuclei of adrenocortical cells. The area of zona fasciculata cells was increased in hyperprolactinemic adult and young rats compared to controls: adults: (61 days: 524.90 ± 47.85 and 244.84 ± 9.03 µm² for treated and control animals, respectively; P < 0.05, and young rats: (15 days: 462.30 ± 16.24 and 414.28 ± 18.19; 60 days: 640.51 ± 12.91 and 480.24 ± 22.79 µm²; P < 0.05. Based on these data we conclude that the increase in adrenal weight observed in the hyperprolactinemic animals may be due to prolactin-induced adrenocortical cell hypertrophy.

  13. Congruence properties of induced representations

    DEFF Research Database (Denmark)

    Mayer, Dieter; Momeni, Arash; Venkov, Alexei

    In this paper we study representations of the projective modular group induced from the Hecke congruence group of level 4 with Selberg's character. We show that the well known congruence properties of Selberg's character are equivalent to the congruence properties of the induced representations...

  14. Laser-induced nuclear fusion

    International Nuclear Information System (INIS)

    Jablon, Claude

    1977-01-01

    Research programs on laser-induced thermonuclear fusion in the United States, in Europe and in USSR are reviewed. The principle of the fusion reactions induced is explained, together with the theoretical effects of the following phenomena: power and type of laser beams, shape and size of the solid target, shock waves, and laser-hydrodynamics coupling problems [fr

  15. Force induced DNA melting

    International Nuclear Information System (INIS)

    Santosh, Mogurampelly; Maiti, Prabal K

    2009-01-01

    When pulled along the axis, double-strand DNA undergoes a large conformational change and elongates by roughly twice its initial contour length at a pulling force of about 70 pN. The transition to this highly overstretched form of DNA is very cooperative. Applying a force perpendicular to the DNA axis (unzipping), double-strand DNA can also be separated into two single-stranded DNA, this being a fundamental process in DNA replication. We study the DNA overstretching and unzipping transition using fully atomistic molecular dynamics (MD) simulations and argue that the conformational changes of double-strand DNA associated with either of the above mentioned processes can be viewed as force induced DNA melting. As the force at one end of the DNA is increased the DNA starts melting abruptly/smoothly above a critical force depending on the pulling direction. The critical force f m , at which DNA melts completely decreases as the temperature of the system is increased. The melting force in the case of unzipping is smaller compared to the melting force when the DNA is pulled along the helical axis. In the case of melting through unzipping, the double-strand separation has jumps which correspond to the different energy minima arising due to sequence of different base pairs. The fraction of Watson-Crick base pair hydrogen bond breaking as a function of force does not show smooth and continuous behavior and consists of plateaus followed by sharp jumps.

  16. Chemotherapy-induced hypocalcemia.

    Science.gov (United States)

    Ajero, Pia Marie E; Belsky, Joseph L; Prawius, Herbert D; Rella, Vincent

    2010-01-01

    To present a unique case of transient, asymptomatic chemotherapy-induced hypocalcemia not attributable to hypomagnesemia or tumor lysis syndrome and review causes of hypocalcemia related to cancer with and without use of chemotherapy. We present a case detailing the clinical and laboratory findings of a patient who had severe hypocalcemia during chemotherapy and discuss causes of hypocalcemia with an extensive literature review of chemotherapeutic agents associated with this biochemical abnormality. In a 90-year-old man, hypocalcemia developed during 2 courses of chemotherapy for Hodgkin lymphoma, with partial recovery between courses and normal serum calcium 10 months after completion of treatment. Magnesium, vitamin D, and parathyroid hormone levels were low normal. There was no evidence of tumor lysis syndrome. Of the various agents administered, vinca alkaloids seemed the most likely cause. Serial testing suggested that the underlying mechanism may have been acquired, reversible hypoparathyroidism. No other similar case was found in the published literature. The severe hypocalcemia in our patient could not be attributed to hypomagnesemia or tumor lysis syndrome, and it was clearly associated with the timing of his chemotherapeutic regimen. Possibilities include direct parathyroid hormone suppression or alteration of calcium sensing by the chemotherapeutic drugs. Serum calcium surveillance before and during chemotherapeutic management of cancer patients may reveal more instances and provide insight into the exact mechanism of this lesser known yet striking complication.

  17. Collision-induced coherence

    International Nuclear Information System (INIS)

    Bloembergen, N.

    1985-01-01

    Collision-induced coherence is based on the elimination of phase correlations between coherent Feynman-type pathways which happen to interfere destructively in the absence of damping for certain nonlinear processes. One consequence is the appearance of the extra resonances in four-wave light mixing experiments, for which the intensity increases with increasing buffer gas pressure. These resonances may occur between a pair of initially unpopulated excited states, or between a pair of initially equally populated ground states. The pair of levels may be Zeeman substrates which became degenerate in zero magnetic field. The resulting collision-enhanced Hanle resonances can lead to very sharp variations in the four-wave light mixing signal as the external magnetic field passes through zero. The theoretical description in terms of a coherence grating between Zeeman substrates is equivalent to a description in terms of a spin polarization grating obtained by collision-enhanced transverse optical pumping. The axis of quantization in the former case is taken perpendicular to the direction of the light beams; in the latter case is taken parallel to this direction

  18. Linezolid induced retinopathy.

    Science.gov (United States)

    Park, Dae Hyun; Park, Tae Kwann; Ohn, Young-Hoon; Park, Jong Sook; Chang, Jee Ho

    2015-12-01

    While optic neuropathy is a well-known cause of visual disturbances in linezolid-treated patients, the possibility of linezolid-related retinopathy has not been investigated. Here, we report a case of retinopathy demonstrated by multifocal electroretinogram (mfERG) in a linezolid-treated patient. A 61-year-old man with extensively drug-resistant pulmonary tuberculosis treated with linezolid for 5 months presented with painless loss of vision in both eyes. The patient's best corrected visual acuity was 20/50 in the right eye and 20/100 in the left eye. Fundus examination revealed mild disc edema, and color vision was defective in both eyes. Humphrey visual field tests showed a superotemporal field defect in the right eye and central and pericentral field defect in the left eye. Optical coherence tomography (OCT) revealed only mild optic disc swelling. In mfERG, central amplitudes were depressed in both eyes. Four months after the cessation of linezolid, visual acuity was restored to 20/20 right eye and 20/25 left eye. The color vision and visual field had improved. The OCT and mfEFG findings improved as well. Although the clinical features were similar to linezolid-induced optic neuropathy, the mfERG findings suggest the possibility of a retinopathy through cone dysfunction.

  19. Food-induced anaphylaxis.

    Science.gov (United States)

    Järvinen, Kirsi M

    2011-06-01

    Food-induced anaphylaxis is the leading single cause of anaphylaxis treated in emergency departments and increasing in prevalence. Food allergy is an increasing problem in westernized countries around the world, with a cumulative prevalence of 3-6%. Peanut, tree nuts, and shellfish are the most commonly implicated foods in anaphylaxis, although milk is a common trigger in children. Asthmatics, adolescents, and those with a prior reaction are at increased risk for more severe reactions. Most first reactions and reactions in children most commonly occur at home, whereas most subsequent reactions and reactions in adults occur outside home. Studies on schools have identified inadequate management plans and symptom recognition whereas those on restaurants report lack of prior notification by allergic individuals and lack in staff education. Epinephrine, although underutilized is the drug of choice with multiple doses needed in up to one-fifth of reactions. Diagnosis is currently based on convincing history and allergy testing supported by elevated serum tryptase, if available. Long-term management includes strict avoidance and emergency action plan. With a growing population of food-allergic children and adults, markers to predict which individuals are at increased risk for anaphylaxis as well as new therapies are vigorously sought.

  20. Methaemoglobinemia Induced by MDMA?

    Directory of Open Access Journals (Sweden)

    L. L. W. Verhaert

    2011-01-01

    Full Text Available Case. A 45-year-old man with a blank medical history presented at the emergency room with dizziness and cyanosis. Physical examination showed cyanosis with a peripheral saturation (SpO2 of 85%, he did not respond to supplemental oxygen. Arterial blood gas analysis showed a striking chocolate brown colour. Based on these data, we determined the arterial methaemoglobin concentration. This was 32%. We gave 100% oxygen and observed the patient in a medium care unit. The next day, patient could be discharged in good condition. Further inquiry about exhibitions and extensive history revealed that the patient used MDMA (3,4- methylenedioxymethamphetamine, the active ingredient of ecstasy. Conclusion. Acquired methaemoglobinemia is a condition that occurs infrequently, but is potentially life threatening. Different nutrients, medications, and chemicals can induce methaemoglobinemia by oxidation of haemoglobin. The clinical presentation of a patient with methaemoglobinemia is due to the impossibility of O2 binding and transport, resulting in tissue hypoxia. Important is to think about methaemoglobin in a patient who presents with cyanosis, a peripheral saturation of 85% that fails to respond properly to the administration of O2. Because methaemoglobin can be reduced physiologically, it is usually sufficient to remove the causative agent, to give O2, and to observe the patient.

  1. Induced mutations in castor

    International Nuclear Information System (INIS)

    Ganesan, K.; Javad Hussain, H.S.; Vindhiyavarman, P.

    2001-01-01

    Castor (Ricinus communis L.) is an important oilseed crop in India. To create variability mutations were induced in two cultivars 'TMV5' (maturing in 130-140 days) and 'CO1' (perennial type). Gamma rays and diethyl sulphate and ethidium bromide were used for seed treatment. Ten doses, from 100 to 1000 Gy were employed. For chemical mutagenesis five concentrations of mutagenes from 10 to 50 mM were tried. No economic mutants could be isolated after treatment with the chemical mutagens. The following economic mutants were identified in the dose 300 Gy of gamma rays. Annual types from perennial CO 1 castor CO 1 is a perennial variety (8-10 years) with bold seeds (100 seed weight 90 g) and high oil content (57%). Twenty-one lines were isolated with annual types (160-180 days) with high yield potential as well as bold seeds and high oil content. These mutants, identified in M 3 generation were bred true in subsequent generations up to M 8 generation. Critical evaluation of the mutants in yield evaluation trials is in progress

  2. Laughter-induced syncope.

    Science.gov (United States)

    Kim, Alexander J; Frishman, William H

    2012-01-01

    Reported cases of syncope caused directly by laughter are rare. The common scenario described in a few reports involved episodes of fortuitous laughter, sometimes followed by a short prodrome of lightheadedness, facial flushing, and dizziness, followed by an episode of definite syncope. There were no seizure-like movements, automatisms, or bladder or bowel incontinence. After the syncopal episodes that were seconds in length, the patients regained consciousness, and at that point were fully oriented. These episodes could recur in a similar situation with such laughter. Many of these patients subsequently underwent full syncope workups, without elucidating a primary cardiac or neurologic cause. In this review of laughter-induced syncope, we describe a patient of ours who fit these descriptions. This phenomenon is likely a subtype of benign Valsalva-related syncope, with autonomic reflex arcs coming into play that ultimately result in global cerebral hypoperfusion. Besides the Valsalva produced by a great fit of laughter, laughter itself has its own neuroendocrine and vasculature effects that may play a role.

  3. Radiation-induced cerebrovasculopathy

    International Nuclear Information System (INIS)

    Ikeyama, Yukihide; Abiko, Seisho; Kurokawa, Yasushi; Okamura, Tomomi; Watanabe, Kohsaku; Inoue, Shinichi; Fujii, Yasuhiro.

    1993-01-01

    We reported a patient who suffered from cerebrovasculopathy after irradiation therapy for astrocytoma located at the left temporal lobe. An eleven year-old boy who presented with headache and vomiting received partial removal of a tumor. Histological diagnosis of the tumor was astrocytoma (grade II). His preoperative cerebral angiograms showed mass sign solely, without stenosis or occlusion of the cerebral vessel. Postoperatively, he was treated with irradiation therapy involving the whole brain with a total of 30 Gy, and gamma knife therapy. Six months after irradiation, he started suffering from frequent cerebral ischemic attacks, but there was no regrowth of the tumor visible on CT scans. Cerebral angiograms were made again, and revealed multifocal stenoses in the bilateral internal carotid arteries, middle cerebral arteries, and the anterior cerebral artery. His symptoms did not improve after conservative treatment with steroids, calcium antagonist, or low molecular weight dextran. Although he received a superficial temporal artery-middle cerebral artery (STA-MCA) anastomoses bilaterally, multiple cerebral infarctions appeared. Although irradiation therapy is acceptable in patients with brain tumor, cerebrovasculopathy after irradiation should be considered as one of the most important complications, and the risk incurred by irradiation therapy should lead to more careful consideration and caution when treating intracranial brain tumors, especially in children. From our experience, the usefulness of bypass surgery for radiation-induced cerebrovasculopathy is still controversial. (author)

  4. Temozolomide-Induced Myelodysplasia

    Directory of Open Access Journals (Sweden)

    Ethan A. Natelson

    2010-01-01

    Full Text Available A patient who had received temozolomide (TMZ as a single agent in treatment of malignant glioma developed therapy-induced myelodysplasia (T-MDS. TMZ is an orally active imidazotetrazine which methylates guanine residues in DNA, ultimately causing single and double-strand DNA breaks leading to apoptotic cell death. TMZ does not chemically cross-link DNA and is considered a nonclassical alkylating agent, similar in structure and activity to dacarbazine. Observations on this patient, and on similarly treated others, suggest that the cumulative dose threshold (CDT for TMZ that predisposes to T-MDS and which may potentially lead to acute myeloid leukemia (T-AML is around 18000 to 20000 mg/sq m. Although the incidence of T-MDS and the predisposing CDT of TMZ may differ from that of other potentially leukemogenic compounds currently and formerly used as chemotherapeutic agents, all alkylating agents, including TMZ, should be considered potentially leukemogenic when administered long term.

  5. Microbiologically induced corrosion

    International Nuclear Information System (INIS)

    Stein, A.A.

    1988-01-01

    Biological attack is a problem that can affect all metallic materials in a variety of environments and systems. In the power industry, corrosion studies have focused on condensers and service water systems where slime, barnacles, clams, and other macro-organisms are easily detected. Efforts have been made to eliminate the effect of these organisms through the use of chlorination, backflushing, organic coating, or thermal shock. The objective is to maintain component performance by eliminating biofouling and reducing metallic corrosion. Recently, corrosion of power plant components by micro-organisms (bacteria) has been identified even in very clean systems. A system's first exposure to microbiologically induced corrosion (MIC) occurs during its first exposure to an aqueous environment, such as during hydrotest or wet layup. Corrosion of buried pipelines by sulfate-reducing bacteria has been studied by the petrochemical industry for years. This paper discusses various methods of diagnosing, monitoring, and controlling MIC in a variety of systems, as well as indicates areas where further study is needed

  6. Doxycycline induced Esophagitis

    Directory of Open Access Journals (Sweden)

    Banu Karakus Yilmaz

    2014-02-01

    Full Text Available Esophagitis is a hazardous condition such as acid reflux of esophageal mucosa, infection, systemic diseases, radiation, drugs and trauma. Drug- induced esophagial injury (DIEI is a disease with the use of variety of drugs that caused serious damage and ulcer in the mucosa of the esophagus. The most commonly implicated drugs are non-steroidal anti-inflammatory drugs (NSAIDs, chloride and especially antibiotics. Thirty-six year-old female patient presented to the emergency department with odynophagia during swallowing and complaining of retrosternal pain. One week before 100 mg doxycycline (2x1 PO for therapeutic abortion were prescribed. It was learned that in the third day of the initiation of medication, the patient\\'s symptoms began and stopped using drug by the fourth day due to advers effect of drugs, but her symptoms didn’t regressed although she didn’t use them. Endoscopy appointment was taken, proton pump inhibitor and antiacid treatment was given, than patient was discharged from the emergency department. In the endoscopy, 20 mm segment esophageal ulcer was seen approximately in the 30.th cm of the esophagius. DIEI is a relatively common, although under-recognized, so this case was presented for remainding DIEI to emergency medicine personals and reweiving its diagnosis, treatment and follow-up.

  7. Ceftazidime-induced thrombocytopenia.

    Science.gov (United States)

    Domingo-Chiva, E; Díaz-Rangel, M; Monsalve-Naharro, J Á; Cuesta-Montero, P; Catalá-Ripoll, J V; García-Martínez, E M

    2017-12-01

    Ceftazidime is an antibiotic belonging to the group of third generation cephalosporins, frequently used in clinical practice for its broad antibacterial spectrum. A case report is presented on a 78-year-old man who entered the intensive care unit due to respiratory failure secondary to nosocomial pneumonia in the postoperative period of a laparoscopic hepatic bisegmentectomy for a hepatocarcinoma. It required invasive mechanical ventilation and was treated with ceftazidime, developing a progressive decrease in platelet count after the onset of this drug and after re-exposure to it, not coinciding with the introduction of other drugs. The adverse reaction was reported to the Spanish pharmacosurveillance system and according to the Naranjo algorithm the causal relationship was probable. Since no case of ceftazidime-induced thrombocytopenia was found in the literature, we consider knowledge of it relevant as an adverse effect to be taken into account given its potential severity, especially when it cannot be explained by other causes. Copyright © 2017 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Publicado por Elsevier España, S.L.U. All rights reserved.

  8. Neutron induced electron radiography

    International Nuclear Information System (INIS)

    Andrade, Marcos Leandro Garcia

    2008-01-01

    In the present paper a new radiography technique, the 'Neutron Induced Electron Radiography' - NIER, to inspect low thickness samples on the order of micra, has been developed. This technique makes use of low energy electrons as penetrating radiation generated from metallic gadolinium screens when irradiated by thermal neutrons. The conditions to obtain the best image for the conventional X-ray film Kodak-AA were determined by using a digital system to quantify the darkening level of the film. The irradiations have been performed at a radiography equipment installed at the beam-hole no. 8 of the 5 MW IEA-R1 nuclear research reactor of IPEN-CNEN/SP. The irradiation time to obtain the best radiography was 100 seconds and for such condition the technique was able to discern 1 μm in 24 μm of aluminum at a resolution of 32 μm. By visual comparison the images obtained by the NIER shown a higher quality when compared with the ones from other usual techniques the make use of electrons a penetrating radiation and films for image registration. Furthermore the use of the digital system has provided a smaller time for data acquisition and data analysis as well as an improvement in the image visualization. (author)

  9. Ion-induced sputtering

    International Nuclear Information System (INIS)

    Yamamura, Yasumichi; Shimizu, Ryuichi; Shimizu, Hazime; Ito, Noriaki.

    1983-01-01

    The research on ion-induced sputtering has been continued for a long time, since a hundred or more years ago. However, it was only in 1969 by Sigmund that the sputtering phenomena were theoretically arranged into the present form. The reason why the importance of sputtering phenomena have been given a new look recently is the application over wide range. This paper is a review centering around the mechanism of causing sputtering and its characteristics. Sputtering is such a phenomenon that the atoms in the vicinity of a solid surface are emitted into vacuum by receiving a part of ion energy, or in other words, it is a kind of irradiation damage in the vicinity of a solid surface. In this meaning, it can be considered that the sputtering based on the ions located on the clean surface of a single element metal is simple, and has already been basically understood. On the contrary, the phenomena can not be considered to be fully understood in the case of alloys and compounds, because these surface conditions under irradiation are not always clear due to segregation and others. In the paper, the physical of sputtering, single element sputtering, the sputtering in alloys and compounds, and the behaviour of emitted particles are explained. Finally, some recent topics of the sputtering measurement by laser resonant excitation, the sputtering by electron excitation, chemical sputtering, and the sputtering in nuclear fusion reactors are described. (Wakatsuki, Y.)

  10. Tumor-induced osteomalacia

    Science.gov (United States)

    Chong, William H; Molinolo, Alfredo A; Chen, Clara C; Collins, Michael T

    2012-01-01

    Tumor-induced osteomalacia (TIO) is a rare and fascinating paraneoplastic syndrome in which patients present with bone pain, fractures, and muscle weakness. The cause is high blood levels of the recently identified phosphate and vitamin D-regulating hormone, fibroblast growth factor 23 (FGF23). In TIO, FGF23 is secreted by mesenchymal tumors that are usually benign, but are typically very small and difficult to locate. FGF23 acts primarily at the renal tubule and impairs phosphate reabsorption and 1α-hydroxylation of 25-hydroxyvitamin D, leading to hypophosphatemia and low levels of 1,25-dihydroxy vitamin D. A step-wise approach utilizing functional imaging (F-18 fluorodeoxyglucose positron emission tomography and octreotide scintigraphy) followed by anatomical imaging (computed tomography and/or magnetic resonance imaging), and, if needed, selective venous sampling with measurement of FGF23 is usually successful in locating the tumors. For tumors that cannot be located, medical treatment with phosphate supplements and active vitamin D (calcitriol or alphacalcidiol) is usually successful; however, the medical regimen can be cumbersome and associated with complications. This review summarizes the current understanding of the pathophysiology of the disease and provides guidance in evaluating and treating these patients. Novel imaging modalities and medical treatments, which hold promise for the future, are also reviewed. PMID:21490240

  11. Asporin and transforming growth factor-beta gene expression in osteoblasts from subchondral bone and osteophytes in osteoarthritis.

    Science.gov (United States)

    Sakao, Kei; Takahashi, Kenji A; Arai, Yuji; Saito, Masazumi; Honjyo, Kuniaki; Hiraoka, Nobuyuki; Kishida, Tsunao; Mazda, Osam; Imanishi, Jiro; Kubo, Toshikazu

    2009-11-01

    To clarify the significance of subchondral bone and osteophytes in the pathology of osteoarthritis (OA), we investigated the expression of asporin (ASPN), transforming growth factor-beta1 (TGF-beta1), TGF-beta2, TGF-beta3, and runt-related transcription factor-2 (Runx2) genes involved in bone metabolism. Osteoblasts were isolated from 19 patients diagnosed with knee OA and from 4 patients diagnosed with femoral neck fracture. Osteoblast expression of mRNA encoding ASPN, TGF-beta1, TGF-beta2, TGF-beta3, and Runx2 was analyzed using real-time RT-PCR. Expression of ASPN, TGF-beta1, and TGF-beta3 mRNA in the subchondral bone and osteophytes of OA patients increased compared with that of non-OA patients. The ratio of ASPN to TGF-beta1 mRNA in patients with severe cartilage damage was higher than that in patients with mild cartilage damage. The increased ratio of ASPN mRNA to TGF-beta1 mRNA in patients with severe relative to mild cartilage damage indicates that increased ASPN mRNA expression was significantly associated with the severity of cartilage degeneration. This finding suggests that ASPN may regulate TGF-beta1-mediated factors in the development of OA, which may provide clues as to the underlying pathology of OA.

  12. Laxative-induced rhabdomyolysis

    Directory of Open Access Journals (Sweden)

    Alfonso Merante

    2010-03-01

    Full Text Available Alfonso Merante1, Pietro Gareri2,3, Norma Maria Marigliano2, Salvatore De Fazio2, Elvira Bonacci1, Carlo Torchia1, Gaetano Russo1, Pasquale Lacroce1, Roberto Lacava3, Alberto Castagna3, Giovambattista De Sarro2, Giovanni Ruotolo11Geriatrist, Geriatric Unit “Pugliese-Ciaccio” Hospital, Catanzaro, Italy; 2Department of Experimental and Clinical Medicine, Faculty of Medicine and Surgery, University Magna Graecia of Catanzaro, Clinical Pharmacology and Pharmacovigilance Unit, Mater Domini University Hospital, Catanzaro, Italy; 3Geriatrist, Operative Unit Elderly Health Care, Catanzaro, ItalyAbstract: The present study describes a case of laxative-induced rhabdomyolysis in an elderly patient. An 87-year-old woman was hospitalized for the onset of confusion, tremors, an inability to walk, and a fever that she had been experiencing for 36 hours. She often took high dosages of lactulose and sorbitol syrup as a laxative (about 70 g/day. During her physical examination, the patient was confused, drowsy, and she presented hyposthenia in her upper and lower limbs, symmetric and diffuse moderate hyporeflexia, and her temperature was 37.8°C. Laboratory tests revealed severe hyponatremia with hypokalemia, hypocalcemia, hypochloremia, and metabolic alkalosis. Moreover, rhabdomyolysis markers were found. The correction of hydroelectrolytic imbalances with saline, potassium and sodium chlorure, calcium gluconate was the first treatment. During her hospitalization the patient presented acute delirium, treated with haloperidol and prometazine chloridrate intramuscularly. She was discharged 12 days later, after resolution of symptoms, and normalized laboratory tests. Over-the-counter drugs such as laxatives are usually not considered dangerous; on the other hand, they may cause serum electrolytic imbalance and rhabdomyolysis. A careful monitoring of all the drugs taken by the elderly is one of the most important duties of a physician since drug interactions and

  13. Tumour-induced osteomalacia.

    Science.gov (United States)

    Minisola, Salvatore; Peacock, Munro; Fukumoto, Seijii; Cipriani, Cristiana; Pepe, Jessica; Tella, Sri Harsha; Collins, Michael T

    2017-07-13

    Tumour-induced osteomalacia (TIO), also known as oncogenic osteomalacia, is a rare paraneoplastic disorder caused by tumours that secrete fibroblast growth factor 23 (FGF23). Owing to the role of FGF23 in renal phosphate handling and vitamin D synthesis, TIO is characterized by decreased renal tubular reabsorption of phosphate, by hypophosphataemia and by low levels of active vitamin D. Chronic hypophosphataemia ultimately results in osteomalacia (that is, inadequate bone mineralization). The diagnosis of TIO is usually suspected when serum phosphate levels are chronically low in the setting of bone pain, fragility fractures and muscle weakness. Locating the offending tumour can be very difficult, as the tumour is often very small and can be anywhere in the body. Surgical removal of the tumour is the only definitive treatment. When the tumour cannot be located or when complete resection is not possible, medical treatment with phosphate salts or active vitamin D is necessary. One of the most promising emerging treatments for unresectable tumours that cause TIO is the anti-FGF23 monoclonal antibody KRN23. The recent identification of a fusion of fibronectin and fibroblast growth factor receptor 1 (FGFR1) as a molecular driver in some tumours not only sheds light on the pathophysiology of TIO but also opens the door to a better understanding of the transcription, translocation, post-translational modification and secretion of FGF23, as well as suggesting approaches to targeted therapy. Further study will reveal if the FGFR1 pathway is also involved in tumours that do not harbour the translocation.

  14. Catecholamine induced cardiomyopathy in pheochromocytoma

    Directory of Open Access Journals (Sweden)

    Ron Thomas Varghese

    2013-01-01

    Full Text Available Catecholamine induced cardiomyopathy in the setting of pheochromocytoma is an unusual clinical entity. Earlier studies have reported left ventricular dysfunction in around 10% of subjects with pheochromocytoma. [1] Catecholamine induced vasoconstriction, direct toxic effect of byproducts of catecholamine degradation and direct receptor-mediated mechanisms are thought to contribute to cardiomyopathy in subjects with pheochromocytoma. The presentation remains a diagnostic challenge as patients may already have hypertensive heart disease and acute coronary syndrome on account of uncontrolled secondary hypertension. We report a case of a 42-year-old male, who presented with features of pheochromocytoma induced cardiomyopathy.

  15. Cisplatin-Induced Eosinophilic Pneumonia

    Directory of Open Access Journals (Sweden)

    Hideharu Ideguchi

    2014-01-01

    Full Text Available A 67-year-old man suffering from esophageal cancer was admitted to our hospital complaining of dyspnea and hypoxemia. He had been treated with cisplatin, docetaxel, and fluorouracil combined with radiotherapy. Chest computed tomography revealed bilateral ground-glass opacity, and bronchoalveolar lavage fluid showed increased eosinophils. Two episodes of transient eosinophilia in peripheral blood were observed after serial administration of anticancer drugs before the admission, and drug-induced lymphocyte stimulation test to cisplatin was positive. Thus cisplatin-induced eosinophilic pneumonia was suspected, and corticosteroid was effectively administered. To our knowledge, this is the first reported case of cisplatin-induced eosinophilic pneumonia.

  16. Systemic resistance induced by rhizosphere bacteria

    NARCIS (Netherlands)

    Loon, L.C. van; Bakker, P.A.H.M.; Pieterse, C.M.J.

    1998-01-01

    Nonpathogenic rhizobacteria can induce a systemic resistance in plants that is phenotypically similar to pathogen-induced systemic acquired resistance (SAR). Rhizobacteria-mediated induced systemic resistance (ISR) has been demonstrated against fungi, bacteria, and viruses in Arabidopsis, bean,

  17. Tumor-induced osteomalacia

    Directory of Open Access Journals (Sweden)

    Pablo Florenzano

    2017-12-01

    Full Text Available Tumor-induced osteomalacia (TIO is a rare paraneoplastic syndrome clinically characterized by bone pain, fractures and muscle weakness. It is caused by tumoral overproduction of fibroblast growth factor 23 (FGF23 that acts primarily at the proximal renal tubule, decreasing phosphate reabsorption and 1α-hydroxylation of 25 hydroxyvitamin D, thus producing hypophosphatemia and osteomalacia. Lesions are typically small, benign mesenchymal tumors that may be found in bone or soft tissue, anywhere in the body. In up to 60% of these tumors, a fibronectin-1(FN1 and fibroblast growth factor receptor-1 (FGFR1 fusion gene has been identified that may serve as a tumoral driver. The diagnosis is established by the finding of acquired chronic hypophosphatemia due to isolated renal phosphate wasting with concomitant elevated or inappropriately normal blood levels of FGF23 and decreased or inappropriately normal 1,25-OH2-Vitamin D (1,25(OH2D. Locating the tumor is critical, as complete removal is curative. For this purpose, a step-wise approach is recommended, starting with a thorough medical history and physical examination, followed by functional imaging. Suspicious lesions should be confirmed by anatomical imaging, and if needed, selective venous sampling with measurement of FGF23. If the tumor is not localized, or surgical resection is not possible, medical therapy with phosphate and active vitamin D is usually successful in healing the osteomalacia and reducing symptoms. However, compliance is often poor due to the frequent dosing regimen and side effects. Furthermore, careful monitoring is needed to avoid complications such us secondary/tertiary hyperparathyroidism, hypercalciuria, and nephrocalcinosis. Novel therapeutical approaches are being developed for TIO patients, such as image-guided tumor ablation and medical treatment with the anti-FGF23 monoclonal antibody KRN23 or anti FGFR medications. The case of a patient with TIO is presented to

  18. Infrasonic induced ground motions

    Science.gov (United States)

    Lin, Ting-Li

    On January 28, 2004, the CERI seismic network recorded seismic signals generated by an unknown source. Our conclusion is that the acoustic waves were initiated by an explosive source near the ground surface. The meteorological temperature and effective sound speed profiles suggested existence of an efficient near-surface waveguide that allowed the acoustic disturbance to propagate to large distances. An explosion occurring in an area of forest and farms would have limited the number of eyewitnesses. Resolution of the source might be possible by experiment or by detailed analysis of the ground motion data. A seismo-acoustic array was built to investigate thunder-induced ground motions. Two thunder events with similar N-wave waveforms but different horizontal slownesses are chosen to evaluate the credibility of using thunder as a seismic source. These impulsive acoustic waves excited P and S reverberations in the near surface that depend on both the incident wave horizontal slowness and the velocity structure in the upper 30 meters. Nineteen thunder events were chosen to further investigate the seismo-acoustic coupling. The consistent incident slowness differences between acoustic pressure and ground motions suggest that ground reverberations were first initiated somewhat away from the array. Acoustic and seismic signals were used to generate the time-domain transfer function through the deconvolution technique. Possible non-linear interaction for acoustic propagation into the soil at the surface was observed. The reverse radial initial motions suggest a low Poisson's ratio for the near-surface layer. The acoustic-to-seismic transfer functions show a consistent reverberation series of the Rayleigh wave type, which has a systematic dispersion relation to incident slownesses inferred from the seismic ground velocity. Air-coupled Rayleigh wave dispersion was used to quantitatively constrain the near-surface site structure with constraints afforded by near-surface body

  19. [Medical induced abortion].

    Science.gov (United States)

    Bettahar, K; Pinton, A; Boisramé, T; Cavillon, V; Wylomanski, S; Nisand, I; Hassoun, D

    2016-12-01

    Updated clinical recommendations for medical induced abortion procedure. A systematic review of French and English literature, reviewing the evidence relating to the provision of medical induced abortion was carried out on PubMed, Cochrane Library and international scientific societies recommendations. The effectiveness of medical abortion is higher than 95% when the protocols are adjusted to gestational age (EL1). Misoprostol alone is less effective than a combination of mifepristone and misoprostol (EL1). Gemeprost is less effective than misoprostol (EL2). The dose of 200mg of mifepristone should be preferred to 600mg (NP1, Rank A). Mifepristone can be taken at home (professional agreement). The optimum interval between mifepristone and misoprostol intake should be 24 to 48 hours (EL1, grade A). Before 7 weeks LMP, the dose of 400μg misoprostol should be given orally (EL1, grade A) eventually repeated after 3hours if no bleeding occurs. For optimal effectiveness between 7 and 14 LMP, the interval between mifepristone and misoprostol should not be shortened to less than 8hours (grade 1). An interval of 24 to 48hours will not affect the effectiveness of the method provided misoprostol dosage is 800μg (EL1). Vaginal, sublingual or buccal routes of administration are more effective and better tolerated than the oral route, which should be abandoned (EL1). An amount of 800μg sublingual or buccal misoprostol route has the same effectiveness than the vaginal route but more gastrointestinal side effects (EL1, grade A). Between 7 and 9 LMP, it does not seem necessary to repeat misoprostol dose whereas it should be repeated beyond 9 SA (grade B). Between 9 and 14 LMP, the dose of 400μg misoprostol given either vaginally, buccally or sublingually should be repeated every 3hours if needed (with a maximum of 5 doses) (EL2, grade B). There is no strong evidence supporting routine antibiotic prophylaxis for medical abortion (professional agreement). Rare contraindications

  20. Mutations induced in plant breeding

    International Nuclear Information System (INIS)

    Barriga B, P.

    1984-01-01

    The most significant aspects of the use of ionizing radiations in plant breeding are reviewed. Aspects such as basic principles of mutation, expression and selection in obtention of mutants, methods for using induced mutations and sucess achieved with this methodology in plant breeding are reviewed. Results obtained in a program of induced mutation on wheat for high content of protein and lysine at the Universidad Austral de Chile are presented. (Author)

  1. Mutations induced in plant breeding

    Energy Technology Data Exchange (ETDEWEB)

    Barriga B, P. (Universidad Austral de Chile, Valdivia. Inst. de Produccion y Sanidad Vegetal)

    1984-10-01

    The most significant aspects of the use of ionizing radiations in plant breeding are reviewed. Aspects such as basic principles of mutation, expression and selection in obtention of mutants, methods for using induced mutations and sucess achieved with this methodology in plant breeding are reviewed. Results obtained in a program of induced mutation on wheat for high content of protein and lysine at the Universidad Austral de Chile are presented.

  2. Holographic Two-Photon Induced Photopolymerization

    Data.gov (United States)

    Federal Laboratory Consortium — Holographic two-photon-induced photopolymerization (HTPIP) offers distinct advantages over conventional one-photon-induced photopolymerization and current techniques...

  3. Mitochondrial Swelling Induced by Glutathione

    Science.gov (United States)

    Lehninger, Albert L.; Schneider, Marion

    1959-01-01

    Reduced glutathione, in concentrations approximating those occurring in intact rat liver, causes swelling of rat liver mitochondria in vitro which is different in kinetics and extent from that yielded by L-thyroxine. The effect is also given by cysteine, which is more active, and reduced coenzyme A, but not by L-ascorbate, cystine, or oxidized glutathione. The optimum pH is 6.5, whereas thyroxine-induced swelling is optimal at pH 7.5. The GSH-induced swelling is not inhibited by DNP or dicumarol, nor by high concentrations of sucrose, serum albumin, or polyvinylpyrrolidone, in contrast to thyroxine-induced swelling. ATP inhibits the GSH swelling, but ADP and AMP are ineffective. Mn-+ is a very potent inhibitor, but Mg++ is ineffective. Ethylenediaminetetraacetate is also an effective inhibitor of GSH-induced swelling. The respiratory inhibitors amytal and antimycin A do not inhibit the swelling action of GSH, but cyanide does; these findings are consistent with the view that the oxidation-reduction state of the respiratory chain between cytochrome c and oxygen is a determinant of GSH-induced swelling. Reversal of GSH-induced swelling by osmotic means or by ATP in KCl media could not be observed. Large losses of nucleotides and protein occur during the swelling by GSH, suggesting that the action is irreversible. The characteristically drastic swelling action of GSH could be prevented if L-thyroxine was also present in the medium. PMID:13630941

  4. Induced mutations in sesame breeding

    International Nuclear Information System (INIS)

    Ashri, A.

    2001-01-01

    The scope of induced mutations in sesame (Sesamum indicum L.) breeding is reviewed. So far in Egypt, India, Iraq, Rep. of Korea, and Sri Lanka, 14 officially released varieties have been developed through induced mutations: 12 directly and 2 through cross breeding (one using the 'dt45' induced mutant from Israel). For another variety released in China there are no details. The induced mutations approach was adopted primarily in order to obtain genetic variability that was not available in the germplasm collection. The mutagens commonly applied have been gamma rays, EMS and sodium azide. Sesame seeds can withstand high mutagen doses, and there are genotypic differences in sensitivity between varieties. The mutants induced in the above named countries and others include better yield, improved seed retention, determinate habit, modified plant architecture and size, more uniform and shorter maturation period, earliness, resistance to diseases, genic male sterility, seed coat color, higher oil content and modified fatty acids composition. Some of the induced mutants have already given rise to improved varieties, the breeding value of other mutants is now being assessed and still others can serve as useful markers in genetic studies and breeding programmes. (author)

  5. Victim-induced criminality.

    Science.gov (United States)

    Fooner, M

    1966-09-02

    about the probable effects on the administration of criminal justice. These are pragmatic problems; there is a third problem which may at this time seem speculative, but is, nevertheless, quite important. 3) To what extent will a particular proposal for victim compensation contribute to a temptation-opportunity pattern in victim behavior? In previous studies it has been pointed out that large numbers of our fellow Americans have tended to acquire casual money-handling habits-generically designated "carelessness"-which contribute to the national growth of criminality. How the victim helps the criminal was sketched in reports of those studies (10). It was made abundantly clear that human beings in our affluent society cannot be assumed to be prudent or self-protective against the hazards of crime. Even when the "victim" is not overtly acting to commit a crime-as in the case of the property owner who hires an arsonist-he often tempts the offender. Among the victims of burglary-statistically the most prevalent crime in the United States-are a substantial number of Americans who keep cash, jewelry, and other valuables carelessly at home or in hotel rooms to which the burglar has easy access through door or window. Victims of automobile theft-one of the fastest growing classes of crime-include drivers who leave the vehicle or its contents invitingly accessible to thieves. And so on with other classes of crime. As pointed out in previous studies, when victim behavior follows a temptation-opportunity pattern, it (i) contributes to a "climate of criminal inducements," (ii) adds to the economic resources available to criminal societies, and (iii) detracts from the ability of lawenforcement agencies to suppress the growth of crime.

  6. Growth factor combination for chondrogenic induction from human mesenchymal stem cell

    International Nuclear Information System (INIS)

    Indrawattana, Nitaya; Chen Guoping; Tadokoro, Mika; Shann, Linzi H.; Ohgushi, Hajime; Tateishi, Tetsuya; Tanaka, Junzo; Bunyaratvej, Ahnond

    2004-01-01

    During the last decade, many strategies for cartilage engineering have been emerging. Stem cell induction is one of the possible approaches for cartilage engineering. The mesenchymal stem cells (MSCs) with their pluripotency and availability have been demonstrated to be an attractive cell source. It needs the stimulation with cell growth factors to make the multipluripotent MSCs differentiate into chondrogenic lineage. We have shown particular patterns of in vitro chondrogenesis induction on human bone marrow MSCs (hBMSCs) by cycling the growth factors. The pellet cultures of hBMSCs were prepared for chondrogenic induction. Growth factors: TGF-β3, BMP-6, and IGF-1 were used in combination for cell induction. Gene expression, histology, immunohistology, and real-time PCR methods were measured on days 21 after cell induction. As shown by histology and immunohistology, the induced cells have shown the feature of chondrocytes in their morphology and extracellular matrix in both inducing patterns of combination and cycling induction. Moreover, the real-time PCR assay has shown the expression of gene markers of chondrogenesis, collagen type II and aggrecan. This study has demonstrated that cartilage tissue can be created from bone marrow mesenchymal stem cells. Interestingly, the combined growth factors TGF-β3 and BMP-6 or TGF-β3 and IGF-1 were more effective for chondrogenesis induction as shown by the real-time PCR assay. The combination of these growth factors may be the important key for in vitro chondrogenesis induction

  7. Hypoxia Is a Critical Parameter for Chondrogenic Differentiation of Human Umbilical Cord Blood Mesenchymal Stem Cells in Type I/III Collagen Sponges

    Directory of Open Access Journals (Sweden)

    Tangni Gómez-Leduc

    2017-09-01

    Full Text Available Umbilical cord blood (UCB is an attractive alternative to bone marrow for isolation of mesenchymal stem cells (MSCs to treat articular cartilage defects. Here, we set out to determine the growth factors (bone morphogenetic protein 2 (BMP-2 and transforming growth factor-β (TGF-β1 and oxygen tension effects during chondrogenesis of human UCB-MSCs for cartilage engineering. Chondrogenic differentiation was induced using 3D cultures in type I/III collagen sponges with chondrogenic factors in normoxia (21% O2 or hypoxia (<5% O2 for 7, 14 and 21 days. Our results show that UCB-MSCs can be committed to chondrogenesis in the presence of BMP-2+TGF-β1. Normoxia induced the highest levels of chondrocyte-specific markers. However, hypoxia exerted more benefit by decreasing collagen X and matrix metalloproteinase-13 (MMP13 expression, two chondrocyte hypertrophy markers. However, a better chondrogenesis was obtained by switching oxygen conditions, with seven days in normoxia followed by 14 days in hypoxia, since these conditions avoid hypertrophy of hUCB-MSC-derived chondrocytes while maintaining the expression of chondrocyte-specific markers observed in normoxia. Our study demonstrates that oxygen tension is a key factor for chondrogenesis and suggests that UBC-MSCs 3D-culture should begin in normoxia to obtain a more efficient chondrocyte differentiation before placing them in hypoxia for chondrocyte phenotype stabilization. UCB-MSCs are therefore a reliable source for cartilage engineering.

  8. Diet-induced obesity attenuates fasting-induced hyperphagia.

    Science.gov (United States)

    Briggs, D I; Lemus, M B; Kua, E; Andrews, Z B

    2011-07-01

    Obesity impairs arcuate (ARC) neuropeptide Y (NPY)/agouti-releated peptide (AgRP) neuronal function and renders these homeostatic neurones unresponsive to the orexigenic hormone ghrelin. In the present study, we investigated the effect of diet-induced obesity (DIO) on feeding behaviour, ARC neuronal activation and mRNA expression following another orexigenic stimulus, an overnight fast. We show that 9 weeks of high-fat feeding attenuates fasting-induced hyperphagia by suppressing ARC neuronal activation and hypothalamic NPY/AgRP mRNA expression. Thus, the lack of appropriate feeding responses in DIO mice to a fast is caused by failure ARC neurones to recognise and/or respond to orexigenic cues. We propose that fasting-induced hyperphagia is regulated not by homeostatic control of appetite in DIO mice, but rather by changes in the reward circuitry. © 2011 The Authors. Journal of Neuroendocrinology © 2011 Blackwell Publishing Ltd.

  9. Sociocultural determinants of induced abortion.

    Science.gov (United States)

    Korejo, Razia; Noorani, Khurshid Jehan; Bhutta, Shereen

    2003-05-01

    To determine the frequency of induced abortion and identify the role of sociocultural factors contributing to termination of pregnancy and associated morbidity and mortality in hospital setting. Prospective observational study. The study was conducted in the Department of Obstetrics and Gynaecology, Jinnah Postgraduate Medical Centre, Karachi from January 1999 to June 2001. The patients who were admitted for induced abortion were interviewed in privacy. On condition of anonymity they were asked about the age, parity, family setup and relationships, with particular emphasis on sociocultural reasons and factors contributing to induction of abortion. Details of status of abortionist and methods used for termination of pregnancy, the resulting complications and their severity were recorded. Out of total admissions, 57(2.35%) gave history of induced abortion. All women belonged to low socioeconomic class and 59.6% of them were illiterate. Forty-three (75.5%) of these women had never practiced contraception. Twenty-four (42%) were grandmultiparae and did not want more children. In 29 women (50.9%) the decision for abortion had been supported by the husband. In 25 women (43.8%) abortion was carried out by Daiyan (traditional midwives). Serious complications like uterine perforation with or without bowel injury were encountered in 25 (43.8%) of these women. During the study period illegally induced abortion accounted for 6 (10.5%) maternal deaths. Prevalence of poverty, illiteracy, grand multiparity and non-practice of contraception are strong determinants of induced abortion.

  10. Sociocultural determinants of induced abortion

    International Nuclear Information System (INIS)

    Korejo, R.; Noorani, K.J.; Bhutta, S.

    2003-01-01

    Objective: To determine the frequency of induced abortion and identity the role of sociocultural factors contributing to termination of pregnancy and associated morbidity and mortality in hospital setting. Subjects and Methods: The patients who were admitted for induced abortion were interviewed in privacy. On condition of anonymity they were asked about the age, parity, family setup and relationships, with particular emphasis on sociocultural reasons and factors contributing to induction of abortion. Details of status of abortionist and methods used for termination of pregnancy, the resulting complications and their severity were recorded. Results: Out of total admissions, 57(2.35%) gave history of induced abortion. All women belonged to low socioeconomic class and 59.6% of them were illiterate. Forty-three (75.5%) of these women had never practiced concentration. Twenty-four (42%) were grandmultiparae and did not want more children. In 29 women (50.9%) the decision for abortion had been supported by the husband. In 25 (43.8%) abortion was carried out by Daiyan (traditional midwives). Serious complications like uterine perforation with or without bowel injury were encouraged in 25 (43.8%) of these women. During the study period illegally induced abortion accounted for 6 (10.5%) maternal deaths. Conclusion: Prevalence of poverty, illiteracy, grand multiparity and non-practice of contraception are strong determinants of induced abortion. (author)

  11. Hydroxyurea-Induced Replication Stress

    Directory of Open Access Journals (Sweden)

    Kenza Lahkim Bennani-Belhaj

    2010-01-01

    Full Text Available Bloom's syndrome (BS displays one of the strongest known correlations between chromosomal instability and a high risk of cancer at an early age. BS cells combine a reduced average fork velocity with constitutive endogenous replication stress. However, the response of BS cells to replication stress induced by hydroxyurea (HU, which strongly slows the progression of replication forks, remains unclear due to publication of conflicting results. Using two different cellular models of BS, we showed that BLM deficiency is not associated with sensitivity to HU, in terms of clonogenic survival, DSB generation, and SCE induction. We suggest that surviving BLM-deficient cells are selected on the basis of their ability to deal with an endogenous replication stress induced by replication fork slowing, resulting in insensitivity to HU-induced replication stress.

  12. Uterine contraction induced by Ghanaian plants used to induce abortion

    DEFF Research Database (Denmark)

    Larsen, Birgitte HV; Soelberg, Jens; Kristiansen, Uffe

    2016-01-01

    Ethnomedicinal observations from the time of the Atlantic slave trade show women in Ghana historically used plants as emmenagogues (menstruation stimulants) and to induce abortion. This study investigates the effect of four of these plants on uterine contraction. The historically used plants were...

  13. Pump cavitation and inducer design

    International Nuclear Information System (INIS)

    Heslenfeld, M.W.; Hes, M. de

    2002-01-01

    Details of past work on sodium pump development and cavitation studies executed mainly for SNR 300 were reported earlier. Among the requirements for large sodium pumps are long life (200000 hours up to 300000 hours) and small size of impeller and pump, fully meeting the process and design criteria. These criteria are the required 'Q, H, r characteristics' in combination with a low NPSH value and the avoidance of cavitation damage to the pump. The pump designer has to develop a sound hydraulic combination consisting of suction arrangement, impeller design and diffuser. On the other hand the designer is free to choose an optimal pump speed. The pump speed in its turn influences the rotor dynamic pump design and the pump drive. The introduction of the inducer as an integral part of the pump design is based on following advantages: no tip cavitation; (possible) cavitation bubbles move to the open centre due to centrifugal forces on the fluid; the head of the inducer improves the inlet conditions of the impeller. The aim of an inducer is the increase in the suction specific speed (SA value) of a pump whereby the inducer functions as a pressure source improving the impeller inlet conditions. With inducer-impeller combinations values up to SA=15000 are realistic. With the use of an inducer the overall pump sizes can be reduced with Ca. 30%. Pumps commonly available have SA values up to a maximum of ca. 10000. A development programme was executed for SNR 300 in order to reach an increase of the suction specific speed of the impeller from SA 8200 to SA 11000. Further studies to optimize pumps design for the follow up line introduced the 'inducer acting as a pre-impeller' development. This programme was executed in the period 1979-1981. At the FDO premises a scale 1 2.8 inducer impeller combination with a suction specific speed SA=15000 was developed, constructed and tested at the water test rig. This water test rig is equipped with a perspex pipe allowing also visualisation

  14. Induced piezoelectricity in isotropic biomaterial.

    Science.gov (United States)

    Zimmerman, R L

    1976-01-01

    Isotropic material can be made to exhibit piezoelectric effects by the application of a constant electric field. For insulators, the piezoelectric strain constant is proportional to the applied electric field and for semiconductors, an additional out-of-phase component of piezoelectricity is proportional to the electric current density in the sample. The two induced coefficients are proportional to the strain-dependent dielectric constant (depsilon/dS + epsilon) and resistivity (drho/dS - rho), respectively. The latter is more important at frequencies such that rhoepsilonomega less than 1, often the case in biopolymers.Signals from induced piezoelectricity in nature may be larger than those from true piezoelectricity. PMID:990389

  15. Drug-induced hair loss.

    Science.gov (United States)

    2016-05-01

    Hair loss can have major psychological consequences. It can be due to a wide variety of causes, including hormonal disorders, dietary factors, infections, inflammation, trauma, emotional factors, and cancer. Drugs can also induce hair loss, by interacting with the hair growth cycle. Drug-induced hair loss may be immediate or delayed, sudden or gradual, and diffuse or localised. It is usually reversible after drug discontinuation. The drugs most often implicated in hair loss are anticancer agents, interferon, azole antifungals, lithium, immunosuppressants, and many other drugs belonging to a variety of pharmacological classes.

  16. Induced radioactivity in LDEF components

    Science.gov (United States)

    Harmon, B. A.; Fishman, G. J.; Parnell, T. A.; Laird, C. E.

    1992-01-01

    A systematic study of the induced radioactivity of the Long Duration Exposure Facility (LDEF) is being carried out in order to gather information about the low earth orbit radiation environment and its effects on materials. The large mass of the LDEF spacecraft, its stabilized configuration, and long mission duration have presented an opportunity to determine space radiation-induced radioactivities with a precision not possible before. Data presented include preliminary activities for steel and aluminum structural samples, and activation subexperiment foils. Effects seen in the data show a clear indication of the trapped proton anisotropy in the South Atlantic Anomaly and suggest contributions from different sources of external radiation fluxes.

  17. Cyclophosphamide-induced pulmonary toxicity

    International Nuclear Information System (INIS)

    Siemann, D.W.; Macler, L.; Penney, D.P.

    1986-01-01

    Unlike radiation effects, pulmonary toxicity following drug treatments may develop soon after exposure. The dose-response relationship between Cyclophosphamide and lung toxicity was investigated using increased breathing frequency assays used successfully for radiation induced injury. The data indicate that release of protein into the alveolus may play a significant role in Cy induced pulmonary toxicity. Although the mechanism responsible for the increased alveolar protein is as yet not identified, the present findings suggest that therapeutic intervention to inhibit protein release may be an approach to protect the lungs from toxic effects. (UK)

  18. Induced modules over group algebras

    CERN Document Server

    Karpilovsky, Gregory

    1990-01-01

    In 1898 Frobenius discovered a construction which, in present terminology, associates with every module of a subgroup the induced module of a group. This construction proved to be of fundamental importance and is one of the basic tools in the entire theory of group representations.This monograph is designed for research mathematicians and advanced graduate students and gives a picture of the general theory of induced modules as it exists at present. Much of the material has until now been available only in research articles. The approach is not intended to be encyclopedic, rather each topic is

  19. Exorcising ghosts in induced gravity

    Energy Technology Data Exchange (ETDEWEB)

    Narain, Gaurav [Chinese Academy of Sciences (CAS), Key Laboratory of Theoretical Physics, Kavli Institute for Theoretical Physics China (KITPC), Institute of Theoretical Physics, Beijing (China)

    2017-10-15

    Unitarity of the scale-invariant coupled theory of higher-derivative gravity and matter is investigated. A scalar field coupled with a Dirac fermion is taken as the matter sector. Following the idea of induced gravity the Einstein-Hilbert term is generated via dynamical symmetry breaking of scale invariance. The renormalisation group flows are computed and one-loop RG improved effective potential of scalar is calculated. The scalar field develops a new minimum via the Coleman-Weinberg procedure inducing the Newton constant and masses in the matter sector. The spin-2 problematic ghost and the spin-0 mode of the metric fluctuation get a mass in the broken phase of the theory. The energy dependence of the vacuum expectation value in the RG improved scenario implies a running for the induced parameters. This sets up platform to ask whether it is possible to evade the spin-2 ghost by keeping its mass always above the running energy scale? In broken phase this question is satisfactorily answered for a large domain of coupling parameter space where the ghost is evaded. The spin-0 mode can be made physically realisable or not depending upon the choice of the initial parameters. The induced Newton constant is seen to vanish in the ultraviolet case. By properly choosing parameters it is possible to make the matter fields physically unrealisable. (orig.)

  20. Eye changes induced by radium

    International Nuclear Information System (INIS)

    Taylor, G.N.; Lloyd, R.D.; Shabestari, Lorraine; Angus, Walter; Muggenburg, B.A.

    1989-01-01

    This report presents some features of the radium induced eye syndrome observed in beagles, including the prominence of intraocular pigmentary lesions and compares these with the results of rodent studies (Onychomys leucogaster) featuring a heavily pigmented uvea, and with the radiation syndrome reported in humans. (author)

  1. On condensation-induced waves

    NARCIS (Netherlands)

    Cheng, W.; Luo, X.; Dongen, van M.E.H.

    2010-01-01

    Complex wave patterns caused by unsteady heat release due to cloud formation in confined compressible flows are discussed. Two detailed numerical studies of condensation-induced waves are carried out. First, the response of a flow of nitrogen in a slender Laval nozzle to a sudden addition of water

  2. Hydralazine-induced constrictive pericarditis

    NARCIS (Netherlands)

    Franssen, CFC; ElGamal, MIH; Gans, ROB; Hoorntje, SJ

    A 59-year-old man was diagnosed as having constrictive pericarditis 17 months after a typical hydralazine-induced autoimmune syndrome, This late complication of hydralazine has been reported only once. Ten years later the patient was found to have anti-neutrophil cytoplasmic antibodies directed

  3. SPS Ion Induced Desorption Experiment

    CERN Multimedia

    Maximilien Brice

    2003-01-01

    This experiment will give a study about the induced desorption from heavy ion (Indium ion run from week 45 in SPS T4-H8 area) impacting LHC type graphite collimator. 4 different samples are located in the 4 chambers 90° one to each other: pure graphite, graphite with copper coating, graphite with NEG coating, 316LN stainless steal (reference).

  4. Food-Induced Acute Pancreatitis.

    Science.gov (United States)

    Manohar, Murli; Verma, Alok K; Upparahalli Venkateshaiah, Sathisha; Goyal, Hemant; Mishra, Anil

    2017-12-01

    Food allergy, a commonly increasing problem worldwide, defined as an adverse immune response to food. A variety of immune-related effector cells such as mast cells, eosinophils, neutrophils, and T cells are involved in food-related allergic responses categorized as IgE mediated, non-IgE mediated, and mixed (IgE and non-IgE) depending upon underlying immunological mechanisms. The dietary antigens mainly target the gastrointestinal tract including pancreas that gets inflamed due to food allergy and leads acute pancreatitis. Reports indicate several food proteins induce pancreatitis; however, detailed underlying mechanism of food-induced pancreatitis is unexplored. The aim of the review is to understand and update the current scenario of food-induced pancreatitis. A comprehensive literature search of relevant research articles has been performed through PubMed, and articles were chosen based on their relevance to food allergen-mediated pancreatitis. Several cases in the literature indicate that acute pancreatitis has been provoked after the consumption of mustard, milk, egg, banana, fish, and kiwi fruits. Food-induced pancreatitis is an ignored and unexplored area of research. The review highlights the significance of food in the development of pancreatitis and draws the attention of physicians and scientists to consider food allergies as a possible cause for initiation of pancreatitis pathogenesis.

  5. Local Anesthetic-Induced Neurotoxicity

    NARCIS (Netherlands)

    Verlinde, Mark; Hollmann, Markus W.; Stevens, Markus F.; Hermanns, Henning; Werdehausen, Robert; Lirk, Philipp

    2016-01-01

    This review summarizes current knowledge concerning incidence, risk factors, and mechanisms of perioperative nerve injury, with focus on local anesthetic-induced neurotoxicity. Perioperative nerve injury is a complex phenomenon and can be caused by a number of clinical factors. Anesthetic risk

  6. Ventilator and viral induced inflammation

    NARCIS (Netherlands)

    Hennus, M.P.

    2013-01-01

    This thesis expands current knowledge on ventilator induced lung injury and provides insights on the immunological effects of mechanical ventilation during viral respiratory infections. The experimental studies in the first part of this thesis improve our understanding of how mechanical ventilation

  7. UV-induced skin damage

    International Nuclear Information System (INIS)

    Ichihashi, M.; Ueda, M.; Budiyanto, A.; Bito, T.; Oka, M.; Fukunaga, M.; Tsuru, K.; Horikawa, T.

    2003-01-01

    Solar radiation induces acute and chronic reactions in human and animal skin. Chronic repeated exposures are the primary cause of benign and malignant skin tumors, including malignant melanoma. Among types of solar radiation, ultraviolet B (290-320 nm) radiation is highly mutagenic and carcinogenic in animal experiments compared to ultraviolet A (320-400 nm) radiation. Epidemiological studies suggest that solar UV radiation is responsible for skin tumor development via gene mutations and immunosuppression, and possibly for photoaging. In this review, recent understanding of DNA damage caused by direct UV radiation and by indirect stress via reactive oxygen species (ROS) and DNA repair mechanisms, particularly nucleotide excision repair of human cells, are discussed. In addition, mutations induced by solar UV radiation in p53, ras and patched genes of non-melanoma skin cancer cells, and the role of ROS as both a promoter in UV-carcinogenesis and an inducer of UV-apoptosis, are described based primarily on the findings reported during the last decade. Furthermore, the effect of UV on immunological reaction in the skin is discussed. Finally, possible prevention of UV-induced skin cancer by feeding or topical use of antioxidants, such as polyphenols, vitamin C, and vitamin E, is discussed

  8. Spaceflight-Induced Intracranial Hypertension.

    Science.gov (United States)

    Michael, Alex P; Marshall-Bowman, Karina

    2015-06-01

    Although once a widely speculated about and largely theoretical topic, spaceflight-induced intracranial hypertension has gained acceptance as a distinct clinical phenomenon, yet the underlying physiological mechanisms are still poorly understood. In the past, many terms were used to describe the symptoms of malaise, nausea, vomiting, and vertigo, though longer duration spaceflights have increased the prevalence of overlapping symptoms of headache and visual disturbance. Spaceflight-induced visual pathology is thought to be a manifestation of increased intracranial pressure (ICP) because of its similar presentation to cases of known intracranial hypertension on Earth as well as the documentation of increased ICP by lumbar puncture in symptomatic astronauts upon return to gravity. The most likely mechanisms of spaceflight-induced increased ICP include a cephalad shift of body fluids, venous outflow obstruction, blood-brain barrier breakdown, and disruption to CSF flow. The relative contribution of increased ICP to the symptoms experienced during spaceflight is currently unknown, though other factors recently posited to contribute include local effects on ocular structures, individual differences in metabolism, and the vasodilator effects of carbon dioxide. This review article attempts to consolidate the literature regarding spaceflight-induced intracranial hypertension and distinguish it from other pathologies with similar symptomatology. It discusses the proposed physiological causes and the pathological manifestations of increased ICP in the spaceflight environment and provides considerations for future long-term space travel. In the future, it will be critical to develop countermeasures so that astronauts can participate at their peak potential and return safely to Earth.

  9. Isolating highly connected induced subgraphs

    DEFF Research Database (Denmark)

    Penev, Irena; Thomasse, Stephan; Trotignon, Nicolas

    2016-01-01

    We prove that any graph G of minimum degree greater than 2k(2) - 1 has a (k + 1)-connected induced subgraph H such that the number of vertices of H that have neighbors outside of H is at most 2k(2) - 1. This generalizes a classical result of Mader, which states that a high minimum degree implies ...

  10. Ultrasound-induced radical polymerization

    NARCIS (Netherlands)

    Kuijpers, M.W.A.; Kemmere, M.F.; Keurentjes, J.T.F.

    2004-01-01

    Sonochemistry comprises all chemical effects that are induced by ultrasound. Most of these effects are caused by cavitations, ie, the collapse of microscopic bubbles in a liquid. The chemical effects of ultrasound include the formation of radicals and the enhancement of reaction rates at ambient

  11. Transdermal hyoscine induced unilateral mydriasis.

    LENUS (Irish Health Repository)

    Hannon, Breffni

    2012-03-20

    The authors present a case of unilateral mydriasis in a teenager prescribed transdermal hyoscine hydrobromide (scopolamine) for chemotherapy induced nausea and vomiting. The authors discuss the ocular side-effects associated with this particular drug and delivery system and the potential use of transdermal hyoscine as an antiemetic agent in this group.

  12. Late onset startle induced tics

    NARCIS (Netherlands)

    Tijssen, MAJ; Brown, P; Morris, HR; Lees, A

    1999-01-01

    Three cases of late onset Gilles de la Tourette's syndrome are presented. The motor ties were mainly induced by an unexpected startling stimulus, but the startle reflex was not exaggerated. The ties developed after physical trauma or a period of undue emotional stress. Reflex ties may occur in

  13. Late onset startle induced tics

    NARCIS (Netherlands)

    Tijssen, M. A.; Brown, P.; Morris, H. R.; Lees, A.

    1999-01-01

    Three cases of late onset Gilles de la Tourette's syndrome are presented. The motor tics were mainly induced by an unexpected startling stimulus, but the startle reflex was not exaggerated. The tics developed after physical trauma or a period of undue emotional stress. Reflex tics may occur in

  14. Visualization of induced electric fields

    NARCIS (Netherlands)

    Deursen, van A.P.J.

    2005-01-01

    A cylindrical electrolytic tank between a set of Helmholtz coils provides a classroom demonstration of induced, nonconservative electric fields. The field strength is measured by a sensor consisting of a pair of tiny spheres immersed in the liquid. The sensor signal depends on position, frequency,

  15. Lithium-induced downbeat nystagmus.

    Science.gov (United States)

    Schein, Flora; Manoli, Pierre; Cathébras, Pascal

    2017-09-01

    We report the case of a 76-year old lady under lithium carbonate for a bipolar disorder who presented with a suspected optic neuritis. A typical lithium-induced downbeat nystagmus was observed. Discontinuation of lithium therapy resulted in frank improvement in visual acuity and disappearance of the nystagmus.

  16. LncRNA-HIT Functions as an Epigenetic Regulator of Chondrogenesis through Its Recruitment of p100/CBP Complexes.

    Science.gov (United States)

    Carlson, Hanqian L; Quinn, Jeffrey J; Yang, Yul W; Thornburg, Chelsea K; Chang, Howard Y; Stadler, H Scott

    2015-12-01

    Gene expression profiling in E 11 mouse embryos identified high expression of the long noncoding RNA (lncRNA), LNCRNA-HIT in the undifferentiated limb mesenchyme, gut, and developing genital tubercle. In the limb mesenchyme, LncRNA-HIT was found to be retained in the nucleus, forming a complex with p100 and CBP. Analysis of the genome-wide distribution of LncRNA-HIT-p100/CBP complexes by ChIRP-seq revealed LncRNA-HIT associated peaks at multiple loci in the murine genome. Ontological analysis of the genes contacted by LncRNA-HIT-p100/CBP complexes indicate a primary role for these loci in chondrogenic differentiation. Functional analysis using siRNA-mediated reductions in LncRNA-HIT or p100 transcripts revealed a significant decrease in expression of many of the LncRNA-HIT-associated loci. LncRNA-HIT siRNA treatments also impacted the ability of the limb mesenchyme to form cartilage, reducing mesenchymal cell condensation and the formation of cartilage nodules. Mechanistically the LncRNA-HIT siRNA treatments impacted pro-chondrogenic gene expression by reducing H3K27ac or p100 activity, confirming that LncRNA-HIT is essential for chondrogenic differentiation in the limb mesenchyme. Taken together, these findings reveal a fundamental epigenetic mechanism functioning during early limb development, using LncRNA-HIT and its associated proteins to promote the expression of multiple genes whose products are necessary for the formation of cartilage.

  17. Regulation of the secretion of immunoregulatory factors of mesenchymal stem cells (MSCs) by collagen-based scaffolds during chondrogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Jingyu; Chen, Xuening, E-mail: xchen6@scu.edu.cn; Yuan, Tun, E-mail: Stalight@163.com; Yang, Xiao; Fan, Yujiang; Zhang, Xingdong

    2017-01-01

    In the latest decade, mesenchymal stem cells (MSCs) have wildly considered as a source of seeded cells in tissue engineering, not only because of its multi-differentiation potentials, but also due to its immunoregulation ability. The main immunoregulatory features of MSCs could be divided into low self-immunogenicity and secretion of soluble factors. In this study, we explored how scaffold structures modulated the secretion of soluble immunoregulatory factors in MSCs under an allogeneic cartilage tissue engineering background. MSCs were seeded in four different collagen-based scaffolds. Their proliferation, differentiation, and secretion of various soluble factors associated with the immunosuppressive effects were evaluated. In this study, qRT-PCR, ELISA and immunoregulation results showed a great variability of the factor secretion by MSCs seeded in scaffolds with different structures. Compared with two-dimensional (2D) monolayer culture condition, three-dimensional (3D) groups (hydrogels and sponge) could effectively promote the mRNA expression and the protein production of soluble immune-related factors. Also, the supernatants collected from 3D groups obviously showed inhibition on allogeneic lymphocyte activating. These results suggested that scaffold structures might modulate MSCs' secretion of soluble immunoregulatory factors, and our study might enlighten the scaffold designs for desired tissue regeneration to control the host immune rejection through immune-regulation reaction. - Highlights: • 3D collagen-based hydrogels and sponge could promote the chondrogenic differentiation of MSCs in vitro. • In accordance with the tendency of chondrogenic differentiation, MSCs in 3D scaffolds could secrete various immunoregulatory factors. • Scaffold structure could regulate the secretion of soluble immunoregulatory factors to inhibited the activity of allogeneic lymphocytes in a paracrine way. • Scaffolds could modulate the immunological properties of allogeneic MSC-derived engineered tissues.

  18. Double printing of hyaluronic acid/poly(glycidol) hybrid hydrogels with poly(ϵ-caprolactone) for MSC chondrogenesis

    NARCIS (Netherlands)

    Stichler, Simone; Böck, Thomas; Paxton, Naomi; Bertlein, Sarah; Levato, Riccardo; Schill, Verena; Smolan, Willi; Malda, Jos; Teßmar, Jörg; Blunk, Torsten; Groll, Jürgen

    2017-01-01

    This study investigates the use of allyl-functionalized poly(glycidol)s (P(AGE-co-G)) as a cytocompatible cross-linker for thiol-functionalized hyaluronic acid (HA-SH) and the optimization of this hybrid hydrogel as bioink for 3D bioprinting. The chemical cross-linking of gels with 10 wt.% overall

  19. The Role of Cyclic AMP and Its Relationship to Parathyroid Hormone Response in an In Vitro Model of Chondrogenesis.

    Science.gov (United States)

    1992-06-01

    factors on bone and cartilage cell equilibria and differentiation will enhance our understanding of bone metabolism in health and disease . A. Parathyroid...1984. Difference between 1-84 parathyroid hormone and the 1-34 fragment on renal tubular calcium transport in the dog . Miner. Electrolyte Metab., ]A...general dentist during a four-year tour. In June 1989, Dr. Semba entered the Postdoctoral Periodontics program at the University of Texas Health Science Center in San Antonio in conjunction with Wilford Hall USAF Medical Center.

  20. Pituitary adenylate cyclase activating polypeptide (PACAP signalling exerts chondrogenesis promoting and protecting effects: implication of calcineurin as a downstream target.

    Directory of Open Access Journals (Sweden)

    Tamás Juhász

    Full Text Available Pituitary adenylate cyclase activating polypeptide (PACAP is an important neurotrophic factor influencing differentiation of neuronal elements and exerting protecting role during traumatic injuries or inflammatory processes of the central nervous system. Although increasing evidence is available on its presence and protecting function in various peripheral tissues, little is known about the role of PACAP in formation of skeletal components. To this end, we aimed to map elements of PACAP signalling in developing cartilage under physiological conditions and during oxidative stress. mRNAs of PACAP and its receptors (PAC1,VPAC1, VPAC2 were detectable during differentiation of chicken limb bud-derived chondrogenic cells in micromass cell cultures. Expression of PAC1 protein showed a peak on days of final commitment of chondrogenic cells. Administration of either the PAC1 receptor agonist PACAP 1-38, or PACAP 6-38 that is generally used as a PAC1 antagonist, augmented cartilage formation, stimulated cell proliferation and enhanced PAC1 and Sox9 protein expression. Both variants of PACAP elevated the protein expression and activity of the Ca-calmodulin dependent Ser/Thr protein phosphatase calcineurin. Application of PACAPs failed to rescue cartilage formation when the activity of calcineurin was pharmacologically inhibited with cyclosporine A. Moreover, exogenous PACAPs prevented diminishing of cartilage formation and decrease of calcineurin activity during oxidative stress. As an unexpected phenomenon, PACAP 6-38 elicited similar effects to those of PACAP 1-38, although to a different extent. On the basis of the above results, we propose calcineurin as a downstream target of PACAP signalling in differentiating chondrocytes either in normal or pathophysiological conditions. Our observations imply the therapeutical perspective that PACAP can be applied as a natural agent that may have protecting effect during joint inflammation and/or may promote cartilage regeneration during degenerative diseases of articular cartilage.

  1. Fluid injection and induced seismicity

    Science.gov (United States)

    Kendall, Michael; Verdon, James

    2016-04-01

    The link between fluid injection, or extraction, and induced seismicity has been observed in reservoirs for many decades. In fact spatial mapping of low magnitude events is routinely used to estimate a stimulated reservoir volume. However, the link between subsurface fluid injection and larger felt seismicity is less clear and has attracted recent interest with a dramatic increase in earthquakes associated with the disposal of oilfield waste fluids. In a few cases, hydraulic fracturing has also been linked to induced seismicity. Much can be learned from past case-studies of induced seismicity so that we can better understand the risks posed. Here we examine 12 case examples and consider in particular controls on maximum event size, lateral event distributions, and event depths. Our results suggest that injection volume is a better control on maximum magnitude than past, natural seismicity in a region. This might, however, simply reflect the lack of baseline monitoring and/or long-term seismic records in certain regions. To address this in the UK, the British Geological Survey is leading the deployment of monitoring arrays in prospective shale gas areas in Lancashire and Yorkshire. In most cases, seismicity is generally located in close vicinity to the injection site. However, in some cases, the nearest events are up to 5km from the injection point. This gives an indication of the minimum radius of influence of such fluid injection projects. The most distant events are never more than 20km from the injection point, perhaps implying a maximum radius of influence. Some events are located in the target reservoir, but most occur below the injection depth. In fact, most events lie in the crystalline basement underlying the sedimentary rocks. This suggests that induced seismicity may not pose a leakage risk for fluid migration back to the surface, as it does not impact caprock integrity. A useful application for microseismic data is to try and forecast induced seismicity

  2. Radiation-induced thermoacoustic imaging

    International Nuclear Information System (INIS)

    Bowen, T.

    1984-01-01

    This invention provides a new technique for obtaining information non-invasively on the composition and structures of a material or body by detecting radiation-induced thermoacoustic image features. This is accomplished by utilizing the acoustic wave generated by sudden thermal stress. The sudden thermal stress is induced by a pulse of radiation which deposits energy causing a rapid, but very small, rise of temperature (typically, ΔT approximately 10sup(-6) - 10sup(-5) deg C). The radiation may be ionizing radiation, such as high energy electrons, photons (x-rays), neutrons, or other charged particles or it may be non-ionizing radiation, such as R.F. and microwave electromagnetic radiation and ultrasonic radiation. The choice of radiation depends on the nature of the body to be imaged and the type of information desired

  3. Esomeprazole-induced photoallergic dermatitis

    Directory of Open Access Journals (Sweden)

    Shukla A

    2010-01-01

    Full Text Available There are no published case reports of esomeprazole-induced photoallergic dermatitis. We report here a 58-year-old lady with prior history of propylthiouracil and carbimazole-induced photoallergy, who presented with heartburn and dysphagia. She was diagnosed to have erosive esophagitis and was treated with esomeprazole, following which she developed photoallergic dermatitis. It improved on cessation of the drug and did not recur on subsequent treatment with ranitidine. Naranjo score for this adverse drug event was 8, thereby making it a probable adverse drug reaction. This reaction may be due to sulphur moiety, which is common to all these drugs. Physicians must be aware of this possible side-effect, especially in patients with prior history of photoallergy to other drugs.

  4. Prediction of pilot induced oscillations

    Directory of Open Access Journals (Sweden)

    Valentin PANĂ

    2011-03-01

    Full Text Available An important problem in the design of flight-control systems for aircraft under pilotedcontrol is the determination of handling qualities and pilot-induced oscillations (PIO tendencieswhen significant nonlinearities exist in the vehicle description. The paper presents a method to detectpossible pilot-induced oscillations of Category II (with rate and position limiting, a phenomenonusually due to a misadaptation between the pilot and the aircraft response during some tasks in whichtight closed loop control of the aircraft is required from the pilot. For the analysis of Pilot in the LoopOscillations an approach, based on robust stability analysis of a system subject to uncertainparameters, is proposed. In this analysis the nonlinear elements are substituted by linear uncertainparameters. This approach assumes that PIO are characterized by a limit cycle behavior.

  5. Taxane-Induced Peripheral Neurotoxicity

    Directory of Open Access Journals (Sweden)

    Roser Velasco

    2015-04-01

    Full Text Available Taxane-derived agents are chemotherapy drugs widely employed in cancer treatment. Among them, paclitaxel and docetaxel are most commonly administered, but newer formulations are being investigated. Taxane antineoplastic activity is mainly based on the ability of the drugs to promote microtubule assembly, leading to mitotic arrest and apoptosis in cancer cells. Peripheral neurotoxicity is the major non-hematological adverse effect of taxane, often manifested as painful neuropathy experienced during treatment, and it is sometimes irreversible. Unfortunately, taxane-induced neurotoxicity is an uncertainty prior to the initiation of treatment. The present review aims to dissect current knowledge on real incidence, underlying pathophysiology, clinical features and predisposing factors related with the development of taxane-induced neuropathy.

  6. Eye changes induced by radium

    International Nuclear Information System (INIS)

    Taylor, G.N.; Lloyd, R.D.; Shabestari, L.; Angus, W.; Muggenburg, B.A.

    1989-01-01

    Radium-induced intraocular neoplasia has not been reported in people, nor were the intraocular pigmentary changes observed in the beagles described in the dial painters or the radium 226 iatrogenic cases. However, Spiess (1969) has observed a 25% incidence of multiple pigmented naevi in the iris of the radium 224 German cases and Stefani, Spiess and Mays (1986) have noted an abnormal incidence of cataracts in this same group of patients. The reasons for the absence of the much less severe radium-induced eye changes in man as compared to the dog has not been determined. Reference is also made to the authors radium 226 rodent studies with mouse strain onychomys leucogaster. (author)

  7. Molecular mechanisms of induced pluripotency.

    Science.gov (United States)

    Kulcenty, Katarzyna; Wróblewska, Joanna; Mazurek, Sylwia; Liszewska, Ewa; Jaworski, Jacek

    2015-01-01

    Growing knowledge concerning transcriptional control of cellular pluripotency has led to the discovery that the fate of differentiated cells can be reversed, which has resulted in the generation, by means of genetic manipulation, of induced pluripotent stem cells. Overexpression of just four pluripotency-related transcription factors, namely Oct3/4, Sox2, Klf4, and c-Myc (Yamanaka factors, OKSM), in fibroblasts appears sufficient to produce this new cell type. Currently, we know that these factors induce several changes in genetic program of differentiated cells that can be divided in two general phases: the initial one is stochastic, and the subsequent one is highly hierarchical and organised. This review briefly discusses the molecular events leading to induction of pluripotency in response to forced presence of OKSM factors in somatic cells. We also discuss other reprogramming strategies used thus far as well as the advantages and disadvantages of laboratory approaches towards pluripotency induction in different cell types.

  8. CEREBRAL CORTEX DAMAGE INDUCED BY ACUTE ORAL ...

    African Journals Online (AJOL)

    2018-02-28

    Feb 28, 2018 ... This study examines alcohol-induced cerebral cortex damage and the association with oxidative ... alcohol has profound effects on the function ... Chronic use of ..... Alcohol induced brain damage and liver damage in young.

  9. Induced disease resistance signaling in plants

    NARCIS (Netherlands)

    Verhagen, B.W.M.; Loon, L.C. van; Pieterse, C.M.J.

    2006-01-01

    To protect themselves from disease, plants have evolved sophisticated inducible defense mechanisms in which the signal molecules salicylic acid, jasmonic acid and ethylene often play crucial roles. Elucidation of signaling pathways controlling induced disease resistance is a major objective in

  10. Inducing Lactation: Breastfeeding for Adoptive Moms

    Science.gov (United States)

    ... Dynamics > Adoption & Foster Care > Inducing Lactation: Breastfeeding for Adoptive Moms Family Life Listen Español Text Size Email Print Share Inducing Lactation: Breastfeeding for Adoptive Moms Page Content Article Body A growing number ...

  11. Induced Mutations in Thai Rice

    International Nuclear Information System (INIS)

    Klakhaeng, Kanchana

    2014-01-01

    Rice is the primary source of food for more than half of the world's population. It benefits greatly from technological inputs in the area of breeding such as induced mutation. Induced mutation can produce mutants with significant improvement in plant type, maturity, yields and protein ratio when compared to the parent. These improved traits enable the mutants to fit into farming systems with either shorter or longer growing seasons. Three induced mutant rice varieties, including RD6, RD10 and RD15, are well accepted by farmers and consumers in Thailand. RD6 and RD15 were aromatic, photosensitive varieties which were derived from KDML105 by acute irradiation of 20 and 15 kilorad gamma ray, respectively. After induced mutation, pedigree selection was applied. RD6 showed drought tolerance and also good grain quality including softness and good aroma with a higher average yield than the famous glutinous variety, San-Pah-Tong. Additionally, it was resistant to blast and brown spot diseases with an average yield of 4.19 tons/ha. RD15 showed drought tolerance and resistance to brown spot disease with the highest yield of 3.5 tons/ha. These two mutant varieties are currently the most famous aromatic rice varieties in Thailand. On the other hand, RD10 is a glutinous, photoperiod insensitive rice variety which was derived from RD1 by irradiation of 1 kilorad fast neutrons. RD10 showed good grain quality such as softness and stickiness with the yield of 4.25 tons/ha. As an on-going project, recommended rice varieties were irradiated with electron beam for anaerobic germination ability, submergence tolerance, stagnant-flood tolerance and also internode elongation.

  12. Abacavir-induced liver toxicity

    Directory of Open Access Journals (Sweden)

    Maria Diletta Pezzani

    2016-09-01

    Full Text Available Abacavir-induced liver toxicity is a rare event almost exclusively occurring in HLA B*5701-positive patients. Herein, we report one case of abnormal liver function tests occurring in a young HLA B*5701-negative woman on a stable nevirapine-based regimen with no history of liver problems or alcohol abuse after switching to abacavir from tenofovir. We also investigated the reasons for abacavir discontinuation in a cohort of patients treated with abacavir-lamivudine-nevirapine.

  13. Cough-induced rib fractures.

    Science.gov (United States)

    Hanak, Viktor; Hartman, Thomas E; Ryu, Jay H

    2005-07-01

    To define the demographic, clinical, and radiological features of patients with cough-induced rib fractures and to assess potential risk factors. For this retrospective, single-center study, we identified all cases of cough-induced rib fractures diagnosed at the Mayo Clinic in Rochester, Minn, over a 9-year period between January 1, 1996, and January 31, 2005. Bone densitometry data from patients' medical records were analyzed, and T scores were used to classify patients into bone density categories. The mean +/- SD age of the 54 study patients at presentation was 55+/-17 years, and 42 patients (78%) were female. Patients presented with chest wall pain after onset of cough. Rib fracture was associated with chronic cough (> or =3 weeks' duration) in 85% of patients. Rib fractures were documented by chest radiography, rib radiography, computed tomography, or bone scan. Chest radiography had been performed in 52 patients and revealed rib fracture in 30 (58%). There were 112 fractured ribs in 54 patients. One half of patients had more than one fractured rib. Right-sided rib fractures alone were present in 17 patients (26 fractured ribs), left-sided in 23 patients (35 fractured ribs), and bilateral in 14 patients (51 fractured ribs). The most commonly fractured rib on both sides was rib 6. The fractures were most common at the lateral aspect of the rib cage. Bone densitometry was done in 26 patients and revealed osteopenia or osteoporosis in 17 (65%). Cough-induced rib fractures occur primarily in women with chronic cough. Middle ribs along the lateral aspect of the rib cage are affected most commonly. Although reduced bone density is likely a risk factor, cough-induced rib fractures can occur in the presence of normal bone density.

  14. Radiation induced crosslinking of polytetrafluoroethylene

    International Nuclear Information System (INIS)

    Oshima, Akihiro; Tabata, Yoneho; Ikeda, Shigetoshi; Otsuhata, Kazushige; Kudoh, Hisaaki; Seguchi, Tadao.

    1995-01-01

    The Irradiation temperature effect on polytetrafluoroethylene (PTFE) from room temperature to 380degC was investigated by tensile test and thermal analysis. The behavior of tensile properties and changes of crystallinity on irradiation indicated the formation of a network structure in PTFE by radiation induced crosslinking in inert gas in the molten state just above the melting temperature of PTFE (327degC). The crosslinked PTFE showed a much improved radiation resistance in an atmospheric radiation field. (author)

  15. Peculiarities of radiation induced craniopharyngioma

    Energy Technology Data Exchange (ETDEWEB)

    Sataev, N.M. (Uzbekskij Nauchno-Issledovatel' skij Inst. Onkologii i Radiologii, Tashkent (USSR))

    1982-03-01

    Due to intracranial implantation of a radiosource in rabbit brain craniopharyngioma appeared. Its specific feature is grandular differentiation of embryonal epithelium of residuals of hypophysical (craniopharyngial) passage and the presence of focuses of blood vessel tumor degeneration of hemangioma type in its stroma. It is suggested that radiation craniopharyngioma is developed along the way of epigenetic changes of cellular elements of embryonal epithelium induced by radiation.

  16. Peculiarities of radiation induced craniopharyngioma

    International Nuclear Information System (INIS)

    Sataev, N.M.

    1982-01-01

    Due to intracranial implantation of a radiosource in rabbit brain craniopharyngioma appeared. Its specific feature is grandular differentiation of embryonal epithelium of residuals of hypophysical (craniopharyngial) passage and the presence of focuses of blood vessel tumor degeneration of hemangioma type in its stroma. It is suggested that radiation craniopharyngioma is developed along the way of epigenetic changes of cellular elements of embryonal epithelium induced by radiation

  17. MRI-induced retrocalcaneal bursitis

    International Nuclear Information System (INIS)

    Tol, J.L.; Dijk, C.N. van; Maas, M.

    1999-01-01

    This case report describes a patient with acute retrocalcaneal bursitis, which developed after MRI examination of the ankle. The sagittal T2*-weighted gradient echo sequence revealed an extensive susceptibility artifact in the area surrounding the Achilles tendon near its insertion at the os calcis. This artifact was caused by postsurgical metallic particles. We postulate that these particles were mechanically stimulated by the magnetic field and induced the inflammatory response. (orig.)

  18. MRI-induced retrocalcaneal bursitis

    Energy Technology Data Exchange (ETDEWEB)

    Tol, J.L.; Dijk, C.N. van [Dept. of Orthopaedic Surgery, University of Amsterdam (Netherlands); Maas, M. [Dept. of Radiology, University of Amsterdam (Netherlands)

    1999-10-01

    This case report describes a patient with acute retrocalcaneal bursitis, which developed after MRI examination of the ankle. The sagittal T2*-weighted gradient echo sequence revealed an extensive susceptibility artifact in the area surrounding the Achilles tendon near its insertion at the os calcis. This artifact was caused by postsurgical metallic particles. We postulate that these particles were mechanically stimulated by the magnetic field and induced the inflammatory response. (orig.)

  19. Teriparatide Induced Delayed Persistent Hypercalcemia

    Directory of Open Access Journals (Sweden)

    Nirosshan Thiruchelvam

    2014-01-01

    Full Text Available Teriparatide, a recombinant PTH, is an anabolic treatment for osteoporosis that increases bone density. Transient hypercalcemia is a reported side effect of teriparatide that is seen few hours following administration of teriparatide and resolves usually within 16 hours of drug administration. Persistent hypercalcemia, although not observed in clinical trials, is rarely reported. The current case describes a rare complication of teriparatide induced delayed persistent hypercalcemia.

  20. Laser-induced multiphoton transitions

    International Nuclear Information System (INIS)

    Stenholm, S.

    1978-06-01

    Laser induced multiphoton processes are reviewed. The effects of strong fields on atoms are discussed. The perturbation treatment is presented and also its generalization to treat intermediate resonances. The influence of atomic coherence is discussed heuristically and the relation between quantal and classical descriptions of the field is elucidated by reference to the dressed atom description. Atomic ionization experiments are reviewed and the present understanding of multiphoton dissociation of molecules is explained. Finally some prospects for the future are discussed. (author)

  1. Drug-induced liver injury

    DEFF Research Database (Denmark)

    Nielsen, Mille Bækdal; Ytting, Henriette; Skalshøi Kjær, Mette

    2017-01-01

    OBJECTIVE: The idiosyncratic subtype of drug-induced liver injury (DILI) is a rare reaction to medical treatment that in severe cases can lead to acute liver failure and death. The aim of this study was to describe the presentation and outcome of DILI and to identify potential predictive factors...... that DILI may be severe and run a fatal course, and that bilirubin and INR levels may predict poor outcome....

  2. Risperidone-induced reversible neutropenia.

    Science.gov (United States)

    Kattalai Kailasam, Vasanth; Chima, Victoria; Nnamdi, Uchechukwu; Sharma, Kavita; Shah, Kairav

    2017-01-01

    This case report presents a 44-year-old man with a history of schizophrenia who developed neutropenia on risperidone therapy. The patient's laboratory reports showed a gradual decline of leukocytes and neutrophils after resolution and rechallenging. This was reversed with the discontinuation of risperidone and by switching to olanzapine. In this case report, we also discuss the updated evidence base for management of risperidone-induced neutropenia.

  3. Induced draught circular cooling tower

    International Nuclear Information System (INIS)

    Blanquet, J.C.

    1980-01-01

    Induced draught atmospheric cooling towers are described, to wit those in which the circulation is by power fans. This technique with fans grouped together in the centre enables a single tower to be used and provides an excellent integration of the steam wreath into the atmosphere. This type of cooling tower has been chosen for fitting out two 900 MW units of the Chinon power station in France [fr

  4. Secondary pseudomyopia induced by amisulpride.

    Science.gov (United States)

    Stratos, Aimilianos A; Peponis, Vasileios G; Portaliou, Dimitra M; Stroubini, Theodora E; Skouriotis, Sotirios; Kymionis, George D

    2011-11-01

    To report a case of pseudomyopia induced by antipsychotic drug administration. A 30-year-old woman was referred to our ophthalmology department complaining of blurred vision, especially at distance, in both eyes. The patient had been prescribed antipsychotic drugs (haloperidol and biperiden) as treatment for her schizophrenic symptoms and had recently undergone a change of treatment to amisulpride. She had a manifest refraction of -4.00/-1.00 × 180 in the OD and -3.75/-1.25 × 175 in the OS whereas her cycloplegic refraction was -1.75/-1.00 × 180 in the OD and -1.00/-1.25 × 175 in the OS, respectively. A diagnosis of likely drug-induced pseudomyopia was made. Therefore, the patient was advised to visit her psychiatrist, who added an extra 2 mg of biperiden, an anticholinergic agent, to the pre-existing amisulpride treatment, achieving a cessation of the visual symptoms a few days later. Pseudomyopia can be induced by the antipsychotic drug amisulpride. Additional treatment with anticholinergic agents can be used to eliminate this side effect.

  5. Radiation-induced chromosomal instability

    International Nuclear Information System (INIS)

    Ritter, S.

    1999-01-01

    Recent studies on radiation-induced chromosomal instability in the progeny of exposed mammalian cells were briefly described as well as other related studies. For the analysis of chromosomal damage in clones, cells were seeded directly after exposure in cell well-dish to form single cell clones and post-irradiation chromosome aberrations were scored. Both exposure to isoeffective doses of X-ray or 270 MeV/u C-ions (13 keV/μm) increased the number of clones with abnormal karyotype and the increase was similar for X-ray and for C-ions. Meanwhile, in the progeny of cells for mass cultures, there was no indication of a delayed expression of chromosomal damage up to 40 population doublings after the exposure. A high number of aberrant cells were only observed directly after exposure to 10.7 MeV/u O-ions, i.e. in the first cycle cells and decreased with subsequent cell divisions. The reason for these differences in the radiation-induced chromosomal instability between clonal isolates and mass culture has not been clarified. Recent studies indicated that genomic instability occurs at a high frequency in the progeny of cells irradiated with both sparsely and densely ionizing radiation. Such genomic instability is thought likely to increase the risk of carcinogenesis, but more data are required for a well understanding of the health risks resulting from radiation-induced delayed instability. (M.N.)

  6. Induced mutation of Dendrobium orchid

    International Nuclear Information System (INIS)

    Sakinah Ariffin; Mohd Nazir Basiran

    2000-01-01

    Dendrobiiim orchids serve as the main orchid cut flower export of Malaysia. The wide range of colour and forms presently available in the market are obtained through hybridisation. Induced mutation breeding program was initiated on a commercial variety Dendrobium 'Sonia Kai' to explore the possibilities of obtaining new colour and forms. Matured seeds from self pollination were cultured and irradiated at 35 Gy at the protocorm-like bodies (PLBS) stage. Selection of induced mutations was done after the first flowering of the plants regenerated from the irradiated protocorms. Results showed changes in flower colour, shape and size. Most of these chances are expressed in different combinations in the petals, sepals and lip of the flowers. Thus, resulting. in a very wide spectrum of mutations. Some of these chances are not stable. To date, mutants that showed stable characteristics changes are grouped into 11 categories based on flower colour and form. These results show that the combination of its vitro technique and induced mutation can be applied in orchid breeding to produce new interesting and attractive variety for the market

  7. [Secondary osteoporosis induced by anticoagulants?].

    Science.gov (United States)

    Riess, H; Loew, A; Himmelreich, G

    2001-07-01

    Generalized osteoporosis is a result of different causes and pathogenic mechanisms, which often combine forces to become clinically relevant. Among the different exogenic factors, drugs play an important role, frequently in connection with other factors such as immobilization or pregnancy. It has been suggested that anticoagulation therapy with heparins or coumarins may induce osteoporotic changes or enhance the development of osteoporosis for other reasons. According to in vitro experiments, preclinical trials, and clinical investigations, it seems reasonable to assume that heparins induce increased bone loss in a time- and dose-related manner. Low-molecular-weight heparins most likely have less effect on bone turnover when compared to unfractionated heparin. Oral anticoagulation therapy with vitamin K-antagonists is believed to have a weak effect on induction of osteoporosis, but clinical studies are contradictory. In spite of the fact that a relevant effect of these drugs on the induction of osteoporosis is questionable, it must be taken into consideration that anticoagulant drugs may enhance the negative effects on bone density of other risk factors capable of inducing osteoporosis such as immobilization, pregnancy, or endocrinological disorders.

  8. Radiation-induced heart injury

    International Nuclear Information System (INIS)

    Suzuki, Yoshihiko; Niibe, Hideo

    1975-01-01

    In order to identify radiation-induced heart injury and to differentiate it from heart disease, an attempt was made to clarify post-irradiation heart injury by investigating the histological changes which occur during the internal between the irradiation and the time of demonstrable histological changes. A study was made of 83 autopsies in which most of the primary neoplasms were breast cancers, lung cancers and mediastinal tumors. In 43 of these autopsies the heart had been irradiated. Sixty eight dd-strain mice were also used for microautoradiographic study. Histological changes in the heart were observed in 27 of the 43 cases receiving irradiation. The limit of the tolerance dose to the heart for indicating histological changes was 1220 ret in humans. The latent period without histological changes was 2.7 months after initiation of radiation therapy. Greater heart injury was observed after re-irradiation or after the combined therapy of radiation and chemotherapy especially mitomycin (MMC). The histological findings after treatment with MMC were similar to those of radiation-induced heart injury. Results of the study indicate that the damage is secondary to radiation-induced changes of the vascula connective tissue. (Evans, G.)

  9. Could visual neglect induce amblyopia?

    Science.gov (United States)

    Bier, J C; Vokaer, M; Fery, P; Garbusinski, J; Van Campenhoudt, G; Blecic, S A; Bartholomé, E J

    2004-12-01

    Oculomotor nerve disease is a common cause of diplopia. When strabismus is present, absence of diplopia has to induce the research of either uncovering of visual fields or monocular suppression, amblyopia or blindness. We describe the case of a 41-year-old woman presenting with right oculomotor paresis and left object-centred visual neglect due to a right fronto-parietal haemorrhage expanding to the right peri-mesencephalic cisterna caused by the rupture of a right middle cerebral artery aneurysm. She never complained of diplopia despite binocular vision and progressive recovery of strabismus, excluding uncovering of visual fields. Since all other causes were excluded in this case, we hypothesise that the absence of diplopia was due to the object-centred visual neglect. Partial internal right oculomotor paresis causes an ocular deviation in abduction; the image being perceived deviated contralaterally to the left. Thus, in our case, the neglect of the left image is equivalent to a right monocular functional blindness. However, bell cancellation test clearly worsened when assessed in left monocular vision confirming that eye patching can worsen attentional visual neglect. In conclusion, our case argues for the possibility of a functional monocular blindness induced by visual neglect. We think that in presence of strabismus, absence of diplopia should induce the search for hemispatial visual neglect when supratentorial lesions are suspected.

  10. [Drug-induced oral ulcerations].

    Science.gov (United States)

    Madinier, I; Berry, N; Chichmanian, R M

    2000-06-01

    Different side effects of drugs have been described in the oral cavity, including oral ulcerations. Direct contact between drugs and oral mucosa may induce chemical burn or local hypersensitivity. Less frequently, these drug-induced oral ulcerations are part of a complex reaction with cutaneous or systemic manifestations. Sometimes, one or more oral ulcerations appear as the main side-effect of a drug, or exceptionally as solitary lesions. Solitary oral ulcerations usually appear after few weeks of treatment. In most of cases, these lesions resist to conventional treatments, with a rapid healing following the suppression of the responsible drug. This diagnosis is usually difficult, particularly with patients receiving multiple drug therapy. Besides, special attention must be paid to new drugs. Oral ulcerations following symptoms of burning mouth, metallic taste, dysgueusia or agueusia are strongly suggestive of a pharmacological origin. Most of the molecules able to induce solitary oral ulcerations are commonly prescribed in a) rheumatology: NSAI (diclofenac, flurbiprofen, indomethacin, naproxen), long-term rheumatoid arthritis therapy (azathioprine, methotrexate, penicillamine, gold compounds, tiopronin); b) cardiology: angiotensin-converting-enzyme inhibitors (captopril, enalapril), angiotensin 2-receptor antagonist (losartan), anti-angorous (nicorandil), c) psychiatry: antidepressants (fluoxetine, lithium), d) AIDS therapy (foscarnet, zalcitabine).

  11. Second-order nonlinearity induced transparency.

    Science.gov (United States)

    Zhou, Y H; Zhang, S S; Shen, H Z; Yi, X X

    2017-04-01

    In analogy to electromagnetically induced transparency, optomechanically induced transparency was proposed recently in [Science330, 1520 (2010)SCIEAS0036-807510.1126/science.1195596]. In this Letter, we demonstrate another form of induced transparency enabled by second-order nonlinearity. A practical application of the second-order nonlinearity induced transparency is to measure the second-order nonlinear coefficient. Our scheme might find applications in quantum optics and quantum information processing.

  12. Diffuse Transcranial Electrical Stimulation (DTES)-induced ...

    African Journals Online (AJOL)

    Higher voltages were needed to induce convulsion in pretreated animals than in normal animals. It is therefore suggestive that DTES-induced hypermotility can be used as an animal model for testing drugs that can be of advantage in the management of non convulsive (petit mal) status epilepticus (SE), and DTES induced ...

  13. Mutations induced by ultraviolet light

    International Nuclear Information System (INIS)

    Pfeifer, Gerd P.; You, Young-Hyun; Besaratinia, Ahmad

    2005-01-01

    The different ultraviolet (UV) wavelength components, UVA (320-400 nm), UVB (280-320 nm), and UVC (200-280 nm), have distinct mutagenic properties. A hallmark of UVC and UVB mutagenesis is the high frequency of transition mutations at dipyrimidine sequences containing cytosine. In human skin cancers, about 35% of all mutations in the p53 gene are transitions at dipyrimidines within the sequence 5'-TCG and 5'-CCG, and these are localized at several mutational hotspots. Since 5'-CG sequences are methylated along the p53 coding sequence in human cells, these mutations may be derived from sunlight-induced pyrimidine dimers forming at sequences that contain 5-methylcytosine. Cyclobutane pyrimidine dimers (CPDs) form preferentially at dipyrimidines containing 5-methylcytosine when cells are irradiated with UVB or sunlight. In order to define the contribution of 5-methylcytosine to sunlight-induced mutations, the lacI and cII transgenes in mouse fibroblasts were used as mutational targets. After 254 nm UVC irradiation, only 6-9% of the base substitutions were at dipyrimidines containing 5-methylcytosine. However, 24-32% of the solar light-induced mutations were at dipyrimidines that contain 5-methylcytosine and most of these mutations were transitions. Thus, CPDs forming preferentially at dipyrimidines with 5-methylcytosine are responsible for a considerable fraction of the mutations induced by sunlight in mammalian cells. Using mouse cell lines harboring photoproduct-specific photolyases and mutational reporter genes, we showed that CPDs (rather than 6-4 photoproducts or other lesions) are responsible for the great majority of UVB-induced mutations. An important component of UVB mutagenesis is the deamination of cytosine and 5-methylcytosine within CPDs. The mutational specificity of long-wave UVA (340-400 nm) is distinct from that of the shorter wavelength UV and is characterized mainly by G to T transversions presumably arising through mechanisms involving oxidized DNA

  14. Statistical Seismology and Induced Seismicity

    Science.gov (United States)

    Tiampo, K. F.; González, P. J.; Kazemian, J.

    2014-12-01

    While seismicity triggered or induced by natural resources production such as mining or water impoundment in large dams has long been recognized, the recent increase in the unconventional production of oil and gas has been linked to rapid rise in seismicity in many places, including central North America (Ellsworth et al., 2012; Ellsworth, 2013). Worldwide, induced events of M~5 have occurred and, although rare, have resulted in both damage and public concern (Horton, 2012; Keranen et al., 2013). In addition, over the past twenty years, the increase in both number and coverage of seismic stations has resulted in an unprecedented ability to precisely record the magnitude and location of large numbers of small magnitude events. The increase in the number and type of seismic sequences available for detailed study has revealed differences in their statistics that previously difficult to quantify. For example, seismic swarms that produce significant numbers of foreshocks as well as aftershocks have been observed in different tectonic settings, including California, Iceland, and the East Pacific Rise (McGuire et al., 2005; Shearer, 2012; Kazemian et al., 2014). Similarly, smaller events have been observed prior to larger induced events in several occurrences from energy production. The field of statistical seismology has long focused on the question of triggering and the mechanisms responsible (Stein et al., 1992; Hill et al., 1993; Steacy et al., 2005; Parsons, 2005; Main et al., 2006). For example, in most cases the associated stress perturbations are much smaller than the earthquake stress drop, suggesting an inherent sensitivity to relatively small stress changes (Nalbant et al., 2005). Induced seismicity provides the opportunity to investigate triggering and, in particular, the differences between long- and short-range triggering. Here we investigate the statistics of induced seismicity sequences from around the world, including central North America and Spain, and

  15. Ion beam induced luminescence: Relevance to radiation induced bystander effects

    Science.gov (United States)

    Ahmad, S. B.; McNeill, F. E.; Byun, S. H.; Prestwich, W. V.; Seymour, C.; Mothersill, C. E.

    2012-10-01

    The aim of this work is quantify the light emitted as a result of charged particle interaction in materials which may be of relevance to radiation induced "bystander effects" studies. We have developed a system which employs single photon counting to measure the light emitted from samples irradiated under vacuum by a charged particle beam. The system uses a fast photomultiplier tube with a peak cathode response at 420 nm. It has been tested in a proof-of-principle experiment using polystyrene targets. Light output, as a result of irradiation, was measured. The luminescence yield appears to have a non-linear behavior with the incident ion fluence: it rises exponentially to an asymptotic value. The target was irradiated with beam energies varying from 1 to 2 MeV and showed saturation at or before an incident fluence rate of 3 × 1013 H+/cm2 s. The average saturation value for the photon output was found to be 40 × 106 cps. Some measurements were performed using filters to study the emission at specific wavelengths. In the case of filtered light measurements, the photon output was found to saturate at 28 × 103, 10 × 106, and 35 × 106 cps for wavelengths of 280 ± 5 nm, 320 ± 5 nm and 340 ± 5 nm respectively. The light output reaches a maximum value because of damage induced in the polymer. Our measurements indicate a "damage cross section" of the order of 10-14 cm2. The average radiant intensity was found to increase at wavelengths of 280 and 320 nm when the proton energy was increased. This was not found to occur at 340 nm. In conclusion, the light emission at specific wavelengths was found to depend upon the incident proton fluence and the proton energy. The wavelengths of the emitted light measured in this study have significance for the understanding of radiation induced bystander effects.

  16. Sad music induces pleasant emotion.

    Science.gov (United States)

    Kawakami, Ai; Furukawa, Kiyoshi; Katahira, Kentaro; Okanoya, Kazuo

    2013-01-01

    In general, sad music is thought to cause us to experience sadness, which is considered an unpleasant emotion. As a result, the question arises as to why we listen to sad music if it evokes sadness. One possible answer to this question is that we may actually feel positive emotions when we listen to sad music. This suggestion may appear to be counterintuitive; however, in this study, by dividing musical emotion into perceived emotion and felt emotion, we investigated this potential emotional response to music. We hypothesized that felt and perceived emotion may not actually coincide in this respect: sad music would be perceived as sad, but the experience of listening to sad music would evoke positive emotions. A total of 44 participants listened to musical excerpts and provided data on perceived and felt emotions by rating 62 descriptive words or phrases related to emotions on a scale that ranged from 0 (not at all) to 4 (very much). The results revealed that the sad music was perceived to be more tragic, whereas the actual experiences of the participants listening to the sad music induced them to feel more romantic, more blithe, and less tragic emotions than they actually perceived with respect to the same music. Thus, the participants experienced ambivalent emotions when they listened to the sad music. After considering the possible reasons that listeners were induced to experience emotional ambivalence by the sad music, we concluded that the formulation of a new model would be essential for examining the emotions induced by music and that this new model must entertain the possibility that what we experience when listening to music is vicarious emotion.

  17. Sad music induces pleasant emotion

    Science.gov (United States)

    Kawakami, Ai; Furukawa, Kiyoshi; Katahira, Kentaro; Okanoya, Kazuo

    2013-01-01

    In general, sad music is thought to cause us to experience sadness, which is considered an unpleasant emotion. As a result, the question arises as to why we listen to sad music if it evokes sadness. One possible answer to this question is that we may actually feel positive emotions when we listen to sad music. This suggestion may appear to be counterintuitive; however, in this study, by dividing musical emotion into perceived emotion and felt emotion, we investigated this potential emotional response to music. We hypothesized that felt and perceived emotion may not actually coincide in this respect: sad music would be perceived as sad, but the experience of listening to sad music would evoke positive emotions. A total of 44 participants listened to musical excerpts and provided data on perceived and felt emotions by rating 62 descriptive words or phrases related to emotions on a scale that ranged from 0 (not at all) to 4 (very much). The results revealed that the sad music was perceived to be more tragic, whereas the actual experiences of the participants listening to the sad music induced them to feel more romantic, more blithe, and less tragic emotions than they actually perceived with respect to the same music. Thus, the participants experienced ambivalent emotions when they listened to the sad music. After considering the possible reasons that listeners were induced to experience emotional ambivalence by the sad music, we concluded that the formulation of a new model would be essential for examining the emotions induced by music and that this new model must entertain the possibility that what we experience when listening to music is vicarious emotion. PMID:23785342

  18. Cetirizine-Induced atrial fibrillation

    Directory of Open Access Journals (Sweden)

    Altuğ Osken

    2016-01-01

    Full Text Available Atrial fibrillation (AF is the most common observed arrhythmia in clinical practice. In the literature, AF events associated with drug induction are available. Cetirizine is a second-generation histamine antagonist used in the treatment of allergies, angioedema, and urticaria. We wish to present an atypical case who took cetirizine medication for relieving symptoms of upper tract respiratory system infection, experienced rapid ventricular response AF and treated successfully. To best of our knowledge, this is the first case of cetirizine-induced AF.

  19. Current-Induced Membrane Discharge

    DEFF Research Database (Denmark)

    Andersen, Mathias Bækbo; van Soestbergen, M.; Mani, A.

    2012-01-01

    . Salt depletion leads to a large electric field resulting in a local pH shift within the membrane with the effect that the membrane discharges and loses its ion selectivity. Since salt co-ions, H+ ions, and OH- ions contribute to OLC, CIMD interferes with electrodialysis (salt counterion removal...... neglects chemical effects and remains to be quantitatively tested. Here, we show that charge regulation and water self-ionization can lead to OLC by "current-induced membrane discharge'' (CIMD), even in the absence of fluid flow, in ion-exchange membranes much thicker than the local Debye screening length...

  20. Adsorption-induced step formation

    DEFF Research Database (Denmark)

    Thostrup, P.; Christoffersen, Ebbe; Lorensen, Henrik Qvist

    2001-01-01

    Through an interplay between density functional calculations, Monte Carlo simulations and scanning tunneling microscopy experiments, we show that an intermediate coverage of CO on the Pt(110) surface gives rise to a new rough equilibrium structure with more than 50% step atoms. CO is shown to bind...... so strongly to low-coordinated Pt atoms that it can break Pt-Pt bonds and spontaneously form steps on the surface. It is argued that adsorption-induced step formation may be a general effect, in particular at high gas pressures and temperatures....

  1. Psychological sequelae of induced abortion.

    Science.gov (United States)

    Romans-Clarkson, S E

    1989-12-01

    This article reviews the scientific literature on the psychological sequelae of induced abortion. The methodology and results of studies carried out over the last twenty-two years are examined critically. The unanimous consensus is that abortion does not cause deleterious psychological effects. Women most likely to show subsequent problems are those who were pressured into the operation against their own wishes, either by relatives or because their pregnancy had medical or foetal contraindications. Legislation which restricts abortion causes problems for women with unwanted pregnancies and their doctors. It is also unjust, as it adversely most affects lower socio-economic class women.

  2. Plasma generation induced by triboelectrification

    DEFF Research Database (Denmark)

    Kusano, Yukihiro; Singh, Shailendra Vikram; Michelsen, Poul

    2009-01-01

    A gas discharge plasma can be induced by triboelectrification around a sliding contact. The detailed physical mechanism of triboelectrification is unknown, but an empirical classification scheme can be referred to in practice. It is reported that intense ultra-violet emission from a plasma...... is observed adjacent to the sliding contact, of which the location has a gap ranging from approximately 1 μm to 11 μm. When the gap is short enough, a theory predicts that the breakdown voltage can monotonically decrease with a decrease in the gap. However, when the gap is comparable to electron’s mean free...

  3. Clozapine-induced late leukopenia.

    LENUS (Irish Health Repository)

    Latif, Z

    2012-03-01

    A patient with a 28-year history of schizophrenia was treated with a wide range of antipsychotic medications since diagnosis. She had experienced no clinically significant symptomatic relief until she commenced treatment on clozapine. Her psychotic symptoms, self care, and general sense of well-being improved significantly. After 6 years of successful treatment, she developed leukopenia and clozapine was discontinued. The following issues will be discussed in the article: rechallenge with clozapine following leukopenia during previous therapy and the choice of and haematological monitoring needs with other antipsychotic medications after clozapine-induced blood dyscrasia.

  4. CRBRP flow induced vibration program

    Energy Technology Data Exchange (ETDEWEB)

    Novendstern, E H [Westinghouse Advanced Reactor Division, Madison, PA (United States); Grochowski, F A; Yang, T M [General Electric Co., Fast Breeder Reactor Department, Sunnyvale, CA (United States); Ryan, J A; Mulcahy, T M

    1977-12-01

    The program to assure the structural adequacy of Clinch River Breeder Reactor (CRBRP) components during its planned 30 years of operation is described. The program includes (1) an assessment of reactor components relative to their susceptibility to FIV, (2) designing to minimize component excitation due to Fluid induced vibrations (FIV), (3) scale model tests to measure structural response during simulated operating conditions and (4) preoperational tests. An overview of the CRBRP test program is described. Additionally, details of scale model testing of reactor internals and the steam generator is described in more detail. (author)

  5. Drug-induced peripheral neuropathy

    DEFF Research Database (Denmark)

    Vilholm, Ole Jakob; Christensen, Alex Alban; Zedan, Ahmed

    2014-01-01

    Peripheral neuropathy can be caused by medication, and various descriptions have been applied for this condition. In this MiniReview, the term 'drug-induced peripheral neuropathy' (DIPN) is used with the suggested definition: Damage to nerves of the peripheral nervous system caused by a chemical...... substance used in the treatment, cure, prevention or diagnosis of a disease. Optic neuropathy is included in this definition. A distinction between DIPN and other aetiologies of peripheral neuropathy is often quite difficult and thus, the aim of this MiniReview is to discuss the major agents associated...

  6. Basic reactions induced by radiation

    International Nuclear Information System (INIS)

    Charlesby, A.

    1980-01-01

    This paper summarises some of the basic reactions resulting from exposure to high energy radiation. In the initial stages energy is absorbed, but not necessarily at random, giving radical and ion species which may then react to promote the final chemical change. However, it is possible to intervene at intermediate stages to modify or reduce the radiation effect. Under certain conditions enhanced reactions are also possible. Several expressions are given to calculate radiation yield in terms of energy absorbed. Some analogies between radiation-induced reactions in polymers, and those studied in radiobiology are outlined. (author)

  7. Diseases induced by ionising radiation

    International Nuclear Information System (INIS)

    1984-11-01

    An interim report is presented by the Industrial Injuries Advisory Council in accordance with Section 141 of the Social Security Act 1975 on the question whether the terms of prescription for occupational diseases induced by ionising radiation should be amended to cover a wider range of conditions. A lack of persuasive statistical data has prevented reliable estimates of health risks of radiation workers in the UK to be made. However the report gives details of the progress made so far and the difficulties encountered. (U.K.)

  8. Radiation Induced Polymerization of Pyrrole

    International Nuclear Information System (INIS)

    Sarada Idris; Ratnam, C.T.; Ahmad Ashrif Abu Bakar

    2016-01-01

    We demonstrate the polymerization of pyrrole by gamma irradiation. The pyrrole films were exposed to gamma ray from cobalt 60 source at doses ranging from 0 to 150 kGy. The films were subjected to structural and morphological analyses by using FTIR, SEM and AFM techniques. Similar studies were also made on pristine pyrrole film which serve as control. Results revealed that pyrrole has been successfully polymerized through irradiation induced reactions. The SEM images depicted the formation of cauliflower shape upon gamma irradiation. The structural changes of pyrrole also evidenced by FTIR spectra. Surface topography and roughness of pyrrole before and after gamma irradiation found to show significant differences. (author)

  9. [Pregnancy-induced haemolytic anaemia].

    Science.gov (United States)

    Karagiozova, J; Masseva, A; Ivanov, St; Marinov, B; Kulinska, R; Boiadjiev, D; Jordanova, D

    2014-01-01

    This is the clinical case of a primiparous eight month pregnant female, presenting with symptoms of pregnancy-induced acute haemolytic anaemia (haemolytic aneamia provoked by an immune mechanism, intra- and extra-erythrocyte defects, and HELLP syndrome were excluded). The anaemia progressed to become life-threatening for both the pregnant women and the foetus, which brought the following questions into consideration: diagnosis of anaemia during pregnancy; dosing of corticosteroid therapy; possibility of giving birth to a viable foetus and prognosis for next pregnancies. Owing to the inter-disciplinary efforts, the life and health of this pregnant woman were preserved, but the foetus was lost.

  10. Ion beam induced luminescence: Relevance to radiation induced bystander effects

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad, S.B., E-mail: ahmad.rabilal@gmail.com [Medical Physics and Applied Radiation Sciences, University of McMaster, Hamilton, Ontario (Canada); McNeill, F.E., E-mail: fmcneill@mcmaster.ca [Medical Physics and Applied Radiation Sciences, University of McMaster, Hamilton, Ontario (Canada); Byun, S.H., E-mail: soohyun@mcmaster.ca [Medical Physics and Applied Radiation Sciences, University of McMaster, Hamilton, Ontario (Canada); Prestwich, W.V., E-mail: prestwic@mcmaster.ca [Medical Physics and Applied Radiation Sciences, University of McMaster, Hamilton, Ontario (Canada); Seymour, C., E-mail: seymouc@mcmaster.ca [Medical Physics and Applied Radiation Sciences, University of McMaster, Hamilton, Ontario (Canada); Mothersill, C.E., E-mail: mothers@mcmaster.ca [Medical Physics and Applied Radiation Sciences, University of McMaster, Hamilton, Ontario (Canada)

    2012-10-01

    The aim of this work is quantify the light emitted as a result of charged particle interaction in materials which may be of relevance to radiation induced 'bystander effects' studies. We have developed a system which employs single photon counting to measure the light emitted from samples irradiated under vacuum by a charged particle beam. The system uses a fast photomultiplier tube with a peak cathode response at 420 nm. It has been tested in a proof-of-principle experiment using polystyrene targets. Light output, as a result of irradiation, was measured. The luminescence yield appears to have a non-linear behavior with the incident ion fluence: it rises exponentially to an asymptotic value. The target was irradiated with beam energies varying from 1 to 2 MeV and showed saturation at or before an incident fluence rate of 3 Multiplication-Sign 10{sup 13} H{sup +}/cm{sup 2} s. The average saturation value for the photon output was found to be 40 Multiplication-Sign 10{sup 6} cps. Some measurements were performed using filters to study the emission at specific wavelengths. In the case of filtered light measurements, the photon output was found to saturate at 28 Multiplication-Sign 10{sup 3}, 10 Multiplication-Sign 10{sup 6}, and 35 Multiplication-Sign 10{sup 6} cps for wavelengths of 280 {+-} 5 nm, 320 {+-} 5 nm and 340 {+-} 5 nm respectively. The light output reaches a maximum value because of damage induced in the polymer. Our measurements indicate a 'damage cross section' of the order of 10{sup -14} cm{sup 2}. The average radiant intensity was found to increase at wavelengths of 280 and 320 nm when the proton energy was increased. This was not found to occur at 340 nm. In conclusion, the light emission at specific wavelengths was found to depend upon the incident proton fluence and the proton energy. The wavelengths of the emitted light measured in this study have significance for the understanding of radiation induced bystander effects.

  11. On the Induced Gravitational Collapse

    Directory of Open Access Journals (Sweden)

    M. Becerra Laura

    2018-01-01

    Full Text Available The induced gravitational collapse (IGC paradigm has been applied to explain the long gamma ray burst (GRB associated with type Ic supernova, and recently the Xray flashes (XRFs. The progenitor is a binary systems of a carbon-oxygen core (CO and a neutron star (NS. The CO core collapses and undergoes a supernova explosion which triggers the hypercritical accretion onto the NS companion (up to 10-2 M⊙s-1. For the binary driven hypernova (BdHNe, the binary system is enough bound, the NS reach its critical mass, and collapse to a black hole (BH with a GRB emission characterized by an isotropic energy Eiso > 1052 erg. Otherwise, for binary systems with larger binary separations, the hypercritical accretion onto the NS is not sufficient to induced its gravitational collapse, a X-ray flash is produced with Eiso < 1052 erg. We’re going to focus in identify the binary parameters that limits the BdHNe systems with the XRFs systems.

  12. Cough-induced rib fractures.

    Science.gov (United States)

    Sano, Atsushi; Tashiro, Ken; Fukuda, Tsutomu

    2015-10-01

    Occasionally, patients who complain of chest pain after the onset of coughing are diagnosed with rib fractures. We investigated the characteristics of cough-induced rib fractures. Between April 2008 and December 2013, 17 patients were referred to our hospital with chest pain after the onset of coughing. Rib radiography was performed, focusing on the location of the chest pain. When the patient had other signs and symptoms such as fever or persistent cough, computed tomography of the chest was carried out. We analyzed the data retrospectively. Rib fractures were found in 14 of the 17 patients. The age of the patients ranged from 14 to 86 years (median 39.5 years). Ten patients were female and 4 were male. Three patients had chronic lung disease. There was a single rib fracture in 9 patients, and 5 had two or more fractures. The middle and lower ribs were the most commonly involved; the 10th rib was fractured most frequently. Cough-induced rib fractures occur in every age group regardless of the presence or absence of underlying disease. Since rib fractures often occur in the lower and middle ribs, rib radiography is useful for diagnosis. © The Author(s) 2015.

  13. Induced gravity II: grand unification

    Energy Technology Data Exchange (ETDEWEB)

    Einhorn, Martin B. [Kavli Institute for Theoretical Physics, Kohn Hall,University of California,Santa Barbara, CA 93106-4030 (United States); Jones, D.R. Timothy [Kavli Institute for Theoretical Physics, Kohn Hall,University of California,Santa Barbara, CA 93106-4030 (United States); Dept. of Mathematical Sciences, University of Liverpool,Peach Street, Liverpool L69 3BX (United Kingdom)

    2016-05-31

    As an illustration of a renormalizable, asymptotically-free model of induced gravity, we consider an SO(10) gauge theory interacting with a real scalar multiplet in the adjoint representation. We show that dimensional transmutation can occur, spontaneously breaking SO(10) to SU(5)⊗U(1), while inducing the Planck mass and a positive cosmological constant, all proportional to the same scale v. All mass ratios are functions of the values of coupling constants at that scale. Below this scale (at which the Big Bang may occur), the model takes the usual form of Einstein-Hilbert gravity in de Sitter space plus calculable corrections. We show that there exist regions of parameter space in which the breaking results in a local minimum of the effective action giving a positive dilaton (mass){sup 2} from two-loop corrections associated with the conformal anomaly. Furthermore, unlike the singlet case we considered previously, some minima lie within the basin of attraction of the ultraviolet fixed point. Moreover, the asymptotic behavior of the coupling constants also lie within the range of convergence of the Euclidean path integral, so there is hope that there will be candidates for sensible vacua. Although open questions remain concerning unitarity of all such renormalizable models of gravity, it is not obvious that, in curved backgrounds such as those considered here, unitarity is violated. In any case, any violation that may remain will be suppressed by inverse powers of the reduced Planck mass.

  14. Inducer Hydrodynamic Load Measurement Devices

    Science.gov (United States)

    Skelley, Stephen E.; Zoladz, Thomas F.

    2002-01-01

    Marshall Space Flight Center (MSFC) has demonstrated two measurement devices for sensing and resolving the hydrodynamic loads on fluid machinery. The first - a derivative of the six component wind tunnel balance - senses the forces and moments on the rotating device through a weakened shaft section instrumented with a series of strain gauges. This "rotating balance" was designed to directly measure the steady and unsteady hydrodynamic loads on an inducer, thereby defining both the amplitude and frequency content associated with operating in various cavitation modes. The second device - a high frequency response pressure transducer surface mounted on a rotating component - was merely an extension of existing technology for application in water. MSFC has recently completed experimental evaluations of both the rotating balance and surface-mount transducers in a water test loop. The measurement bandwidth of the rotating balance was severely limited by the relative flexibility of the device itself, resulting in an unexpectedly low structural bending mode and invalidating the higher frequency response data. Despite these limitations, measurements confirmed that the integrated loads on the four-bladed inducer respond to both cavitation intensity and cavitation phenomena. Likewise, the surface-mount pressure transducers were subjected to a range of temperatures and flow conditions in a non-rotating environment to record bias shifts and transfer functions between the transducers and a reference device. The pressure transducer static performance was within manufacturer's specifications and dynamic response accurately followed that of the reference.

  15. Chaos for induced hyperspace maps

    International Nuclear Information System (INIS)

    Banks, John

    2005-01-01

    For (X,d) be a metric space, f:X->X a continuous map and (K(X),H) the space of non-empty compact subsets of X with the Hausdorff metric, one may study the dynamical properties of the induced map (*)f-bar :K(X)->K(X):A-bar f(A).H. Roman-Flores [A note on in set-valued discrete systems. Chaos, Solitons and Fractals 2003;17:99-104] has shown that if f-bar is topologically transitive then so is f, but that the reverse implication does not hold. This paper shows that the topological transitivity of f-bar is in fact equivalent to weak topological mixing on the part of f. This is proved in the more general context of an induced map on some suitable hyperspace H of X with the Vietoris topology (which agrees with the topology of the Hausdorff metric in the case discussed by Roman-Flores

  16. Condensation induced water hammer safety

    International Nuclear Information System (INIS)

    Gintner, M.A.

    1997-01-01

    Condensation induced water hammer events in piping systems can cause catastrophic steam system failures which can result in equipment damage, personal injury, and even death. As an industry, we have learned to become accustomed to the ''banging'' that we often hear in our steam piping systems, and complacent in our actions to prevent it. It is unfortunate that lives are lost needlessly, as this type of water hammer event is preventable if one only applies some basic principles when operating and maintaining their steam systems. At the U. S. Department of Energy's Hanford Site where I work, there was one such accident that occurred in 1993 which took the life of a former co-worker and friend of mine. Hanford was established as part of the Manhattan Project during World War II. it is a 560 square mile complex located along the banks of the Columbia River in Southeastern Washington State. For almost 45 years, hanford's mission was to produce weapons grade plutonium for our nations defense programs. Today, Hanford no longer produces plutonium, but is focused on site clean-up and economic diversification. Hanford still uses steam for heating and processing activities, utilizing over 20 miles of piping distribution systems similar to those found in industry. Although these aging systems are still sound, they cannot stand up to the extreme pressure pulses developed by a condensation induced water hammer

  17. Psychosocial aspects of induced abortion.

    Science.gov (United States)

    Stotland, N L

    1997-09-01

    US anti-abortion groups have used misinformation on the long-term psychological impact of induced abortion to advance their position. This article reviews the available research evidence on the definition, history, cultural context, and emotional and psychiatric sequelae of induced abortion. Notable has been a confusion of normative, transient reactions to unintended pregnancy and abortion (e.g., guilt, depression, anxiety) with serious mental disorders. Studies of the psychiatric aspects of abortion have been limited by methodological problems such as the impossibility of randomly assigning women to study and control groups, resistance to follow-up, and confounding variables. Among the factors that may impact on an unintended pregnancy and the decision to abort are ongoing or past psychiatric illness, poverty, social chaos, youth and immaturity, abandonment issues, ongoing domestic responsibilities, rape and incest, domestic violence, religion, and contraceptive failure. Among the risk factors for postabortion psychosocial difficulties are previous or concurrent psychiatric illness, coercion to abort, genetic or medical indications, lack of social supports, ambivalence, and increasing length of gestation. Overall, the literature indicates that serious psychiatric illness is at least 8 times more common among postpartum than among postabortion women. Abortion center staff should acknowledge that the termination of a pregnancy may be experienced as a loss even when it is a voluntary choice. Referrals should be offered to women who show great emotional distress, have had several previous abortions, or request psychiatric consultation.

  18. Drug-induced hepatic injury

    DEFF Research Database (Denmark)

    Friis, Henrik; Andreasen, P B

    1992-01-01

    The Danish Committee on Adverse Drug Reactions received 1100 reports of suspected drug-induced hepatic injury during the decade 1978-1987. The causal relationship between drug and hepatic injury was classified as definite in 57 (5.2%) reports, probable in 989 (89.9%) reports, possible in 50 (4.......5%) reports and unclassifiable in four (0.4%) reports. Hepatic injuries accounted for 5.9% of all adverse drug reactions reported, and 14.7% of the lethal adverse drug reactions. A total of 47.2% were classified as acute cytotoxic, 16.2% as acute cholestatic and 26.9% as abnormal hepatic function. In 52 (4.......7%) cases the hepatic injury was lethal; only 14 (1.3%) cases were chronic. Halothane accounted for 25% of the cases. The incidence of halothane-induced hepatic injury is decreasing, and only one lethal case has been reported since 1981. Next to halothane, sulfasalazine was the drug most often suspected...

  19. Condensation induced water hammer safety

    Energy Technology Data Exchange (ETDEWEB)

    Gintner, M.A.

    1997-03-10

    Condensation induced water hammer events in piping systems can cause catastrophic steam system failures which can result in equipment damage, personal injury, and even death. As an industry, we have learned to become accustomed to the ''banging'' that we often hear in our steam piping systems, and complacent in our actions to prevent it. It is unfortunate that lives are lost needlessly, as this type of water hammer event is preventable if one only applies some basic principles when operating and maintaining their steam systems. At the U. S. Department of Energy's Hanford Site where I work, there was one such accident that occurred in 1993 which took the life of a former co-worker and friend of mine. Hanford was established as part of the Manhattan Project during World War II. it is a 560 square mile complex located along the banks of the Columbia River in Southeastern Washington State. For almost 45 years, hanford's mission was to produce weapons grade plutonium for our nations defense programs. Today, Hanford no longer produces plutonium, but is focused on site clean-up and economic diversification. Hanford still uses steam for heating and processing activities, utilizing over 20 miles of piping distribution systems similar to those found in industry. Although these aging systems are still sound, they cannot stand up to the extreme pressure pulses developed by a condensation induced water hammer.

  20. Shear induced phase transitions induced in edible fats

    Science.gov (United States)

    Mazzanti, Gianfranco; Welch, Sarah E.; Marangoni, Alejandro G.; Sirota, Eric B.; Idziak, Stefan H. J.

    2003-03-01

    The food industry crystallizes fats under different conditions of temperature and shear to obtain products with desired crystalline phases. Milk fat, palm oil, cocoa butter and chocolate were crystallized from the melt in a temperature controlled Couette cell. Synchrotron x-ray diffraction studies were conducted to examine the role of shear on the phase transitions seen in edible fats. The shear forces on the crystals induced acceleration of the alpha to beta-prime phase transition with increasing shear rate in milk fat and palm oil. The increase was slow at low shear rates and became very strong above 360 s-1. In cocoa butter the acceleration between beta-prime-III and beta-V phase transition increased until a maximum of at 360 s-1, and then decreased, showing competition between enhanced heat transfer and viscous heat generation.

  1. Amoxicillin-induced aseptic meningoencephalitis

    Directory of Open Access Journals (Sweden)

    Radi Shahien

    2010-06-01

    Full Text Available Radi Shahien1, Vetaly Vieksler1, Abdalla Bowirrat11Department of Neurology and Neurophysiology, Ziv Medical Center, Safed, IsraelAbstract: Meningitis is usually produced by an infectious agent, but there are multiple noninfectious causes. Drug-induced aseptic meningitis (DIAM is an important entity and has been reported as an uncommon adverse reaction with numerous agents. Thus, DIAM constitutes a diagnostic and patient management challenge. We present a patient with three episodes of aseptic meningitis due to amoxicillin, and then review the literature on this rare idiosyncratic event which may occur after local or systemic drug administration. A 77-year-old man was admitted to our hospital with fever, headache, and neck stiffness. Seven days before admission he had a dental and gingival inflammation. He was treated with two oral doses of 500 mg daily of amoxicillin for one week. The seventh day he awoke with the complaints that prompted hospital admittance. Amoxicillin was stopped 1 day before his admission. From his history we knew of two similar episodes: The first episode was after a dental procedure 3 months before this incident. He had received a 1-week course of postprocedure amoxicillin of 500 mg daily and had similar headache, fever, and chills during the entire course of treatment. He wasn’t admitted to the hospital, because he stopped taking amoxicillin and he felt spontaneous pain relief after taking symptomatic pain treatment. The second episodes was 6 months after his first admission, he had been admitted to our hospital with the same symptoms. Amoxicillin was stopped and changed with intravenous (IV ceftriaxone (CTRX for 10 days due to suspected partial untreated meningitis. The patient improved rapidly within 2 days and was discharged from the hospital. On the basis of these three confirmed episodes of meningitis after recurrent exposure to amoxicillin, with repetitive negative testing for viral, bacterial, and mycobacterial

  2. Hemolysis induced by PMIVSD occluder

    Directory of Open Access Journals (Sweden)

    D. Sheshagiri Rao

    2016-09-01

    Full Text Available Hemolysis related to occluder, prosthetic valve, and prosthetic ring used for mitral valve annuloplasty are not very unusual. However, hemolysis related to transcathetor closure of post-myocardial infarction ventricular septal defect (PMIVSD is infrequent. A close follow-up for spontaneous resolution with or without blood transfusion has been reported in a few cases. Occasionally, surgical retrieval is unavoidable or lifelong blood transfusion is required if surgery cannot be done because of higher risk. In this illustration, we have showed a close follow-up of a case of hemolysis induced by atrial septal occluder used for VSD closure after myocardial infarction. Despite successful device closure of PMIVSD which is difficult, a close watch is needed for complications like residual leak, device embolization, and hemolysis.

  3. Hemolysis induced by PMIVSD occluder.

    Science.gov (United States)

    Rao, D Sheshagiri; Barik, Ramachandra; Siva Prasad, Akula

    2016-09-01

    Hemolysis related to occluder, prosthetic valve, and prosthetic ring used for mitral valve annuloplasty are not very unusual. However, hemolysis related to transcathetor closure of post-myocardial infarction ventricular septal defect (PMIVSD) is infrequent. A close follow-up for spontaneous resolution with or without blood transfusion has been reported in a few cases. Occasionally, surgical retrieval is unavoidable or lifelong blood transfusion is required if surgery cannot be done because of higher risk. In this illustration, we have showed a close follow-up of a case of hemolysis induced by atrial septal occluder used for VSD closure after myocardial infarction. Despite successful device closure of PMIVSD which is difficult, a close watch is needed for complications like residual leak, device embolization, and hemolysis. Copyright © 2016 Cardiological Society of India. Published by Elsevier B.V. All rights reserved.

  4. Rice breeding with induced mutations

    Energy Technology Data Exchange (ETDEWEB)

    1968-06-01

    The Joint FAO/IAEA Division of Atomic Energy in Food and Agriculture decided in 1964 to organize a co-ordinated research programme on the use of induced mutations in rice breeding. The programme was organized within the framework of activities of the International Rice Commission. This is a report of the Third Co-ordination Meeting of the participants, which was held in Taipei, 5-9 June 1967. As the projects, which together make up the co-ordinated programme, are at different stages of progress, the report contains a variety of papers including completed studies, field and progress reports, and highlights of the discussions with some additional recommendations prepared by the participants. Refs, figs and tabs.

  5. Uncommon vancomycin: induced side effects

    Directory of Open Access Journals (Sweden)

    Rocha Jaime Luís Lopes

    2002-01-01

    Full Text Available Vancomycin has been used with increased frequency during the past 15 years and the most common toxicity with this drug is the "red man syndrome". Other adverse effects include neutropenia, fever, phlebitis, nephrotoxicity, ototoxicity, thrombocytopenia, interstitial nephritis, lacrimation, linear IgA bullous dermatosis, necrotizing cutaneous vasculitis and toxic epidermal necrolysis. Only two cases of vancomycin-induced Stevens-Johnson syndrome and one case of pancytopenia have been reported in the medical literature. The treatment for both situations is based on cessation of the vancomycin therapy; in cases of Stevens-Johnson syndrome, antihistamine and/or steroid agents can be used. This article reports a case of pancytopenia and a case of erythema major associated with neutropenia.

  6. Typhoon-Induced Ground Deformation

    Science.gov (United States)

    Mouyen, M.; Canitano, A.; Chao, B. F.; Hsu, Y.-J.; Steer, P.; Longuevergne, L.; Boy, J.-P.

    2017-11-01

    Geodetic instruments now offer compelling sensitivity, allowing to investigate how solid Earth and surface processes interact. By combining surface air pressure data, nontidal sea level variations model, and rainfall data, we systematically analyze the volumetric deformation of the shallow crust at seven borehole strainmeters in Taiwan induced by 31 tropical cyclones (typhoons) that made landfall to the island from 2004 to 2013. The typhoon's signature consists in a ground dilatation due to air pressure drop, generally followed by a larger ground compression. We show that this compression phase can be mostly explained by the mass loading of rainwater that falls on the ground and concentrates in the valleys towards the strainmeter sensitivity zone. Further, our analysis shows that borehole strainmeters can help quantifying the amount of rainwater accumulating and flowing over a watershed during heavy rainfalls, which is a useful constraint for building hydrological models.

  7. Mental disorders induced by carbamazepine.

    Science.gov (United States)

    Mizukami, K; Naito, Y; Yoshida, M; Nakanishi, T; Koizumi, J

    1990-03-01

    We present here a case with various physical and neuropsychiatric symptoms caused by the administration of carbamazepine. The patient suffering from right ophthalmic neuralgia showed fever, eczema, erythema, lymphoadenopathy, eosinophilia, vomiting, headache, dizziness, nystagmus, and various mental disorders which consisted of emotional instability, personality change, delusions of reference and persecution, depressive state, and hyperventilation syndrome during the administration of carbamazepine. The physical symptoms in the present case were conformable to the side effect of carbamazepine. The mental disorders appeared in a few days from the start of carbamazepine administration and disappeared after the discontinuation of the administration of this drug without antipsychotic therapy and have never relapsed until now. The mental disorders and the physical symptoms were in parallel with their clinical course. This kind of mental disorders induced by carbamazepine has not yet been reported.

  8. Antiphospholipid Antibody Induced by Nivolumab

    Directory of Open Access Journals (Sweden)

    Ahmed Aburahma

    2018-01-01

    Full Text Available Nivolumab is a monoclonal antibody against the programmed death protein 1 and is used for patients with advanced melanoma. It is associated with potentially immune-related adverse events, including disorders of the skin, GI tract, and the thyroid; these disorders were successfully treated with prednisone and infliximab. Other immunotherapeutic agents were observed to induce the formation of antiphospholipid antibody (APA including α-interferon and interleukin-2. We present a case of APA development after the third dose of nivolumab in a 71-year-old male with advanced melanoma. The APA was detected after finding a prolonged aPTT; the lupus anticoagulant assay tested positive. The patient was treated with prednisone but, unfortunately, he expired a few days later.

  9. Human-induced Arctic moistening.

    Science.gov (United States)

    Min, Seung-Ki; Zhang, Xuebin; Zwiers, Francis

    2008-04-25

    The Arctic and northern subpolar regions are critical for climate change. Ice-albedo feedback amplifies warming in the Arctic, and fluctuations of regional fresh water inflow to the Arctic Ocean modulate the deep ocean circulation and thus exert a strong global influence. By comparing observations to simulations from 22 coupled climate models, we find influence from anthropogenic greenhouse gases and sulfate aerosols in the space-time pattern of precipitation change over high-latitude land areas north of 55 degrees N during the second half of the 20th century. The human-induced Arctic moistening is consistent with observed increases in Arctic river discharge and freshening of Arctic water masses. This result provides new evidence that human activity has contributed to Arctic hydrological change.

  10. Valproic Acid-induced Agranulocytosis

    Directory of Open Access Journals (Sweden)

    Hui-Chuan Hsu

    2009-06-01

    Full Text Available Valproic acid is considered to be the most well-tolerated antiepileptic drug. However, few cases of neutropenia or leukopenia caused by valproic acid have been reported. We present a patient who took valproic acid to treat a complication of brain surgery and in whom severe agranulocytosis occurred after 2.5 months. Valproic acid was stopped immediately, and granulocyte colony-stimulating factor was administered for 2 days. The patient's white blood cell count returned to normal within 2 weeks. The result of bone marrow aspiration was compatible with drug-induced agranulocytosis. This case illustrates that patients who take valproic acid may need regular checking of complete blood cell count.

  11. Magnetic field induced dynamical chaos.

    Science.gov (United States)

    Ray, Somrita; Baura, Alendu; Bag, Bidhan Chandra

    2013-12-01

    In this article, we have studied the dynamics of a particle having charge in the presence of a magnetic field. The motion of the particle is confined in the x-y plane under a two dimensional nonlinear potential. We have shown that constant magnetic field induced dynamical chaos is possible even for a force which is derived from a simple potential. For a given strength of the magnetic field, initial position, and velocity of the particle, the dynamics may be regular, but it may become chaotic when the field is time dependent. Chaotic dynamics is very often if the field is time dependent. Origin of chaos has been explored using the Hamiltonian function of the dynamics in terms of action and angle variables. Applicability of the present study has been discussed with a few examples.

  12. Gravity induced wave function collapse

    Science.gov (United States)

    Gasbarri, G.; Toroš, M.; Donadi, S.; Bassi, A.

    2017-11-01

    Starting from an idea of S. L. Adler [in Quantum Nonlocality and Reality: 50 Years of Bell's Theorem, edited by M. Bell and S. Gao (Cambridge University Press, Cambridge, England 2016)], we develop a novel model of gravity induced spontaneous wave function collapse. The collapse is driven by complex stochastic fluctuations of the spacetime metric. After deriving the fundamental equations, we prove the collapse and amplification mechanism, the two most important features of a consistent collapse model. Under reasonable simplifying assumptions, we constrain the strength ξ of the complex metric fluctuations with available experimental data. We show that ξ ≥10-26 in order for the model to guarantee classicality of macro-objects, and at the same time ξ ≤10-20 in order not to contradict experimental evidence. As a comparison, in the recent discovery of gravitational waves in the frequency range 35 to 250 Hz, the (real) metric fluctuations reach a peak of ξ ˜10-21.

  13. Molecular Mechanisms of Induced Pluripotency

    Science.gov (United States)

    Muchkaeva, I.A.; Dashinimaev, E.B.; Terskikh, V.V.; Sukhanov, Y.V.; Vasiliev, A.V.

    2012-01-01

    In this review the distinct aspects of somatic cell reprogramming are discussed. The molecular mechanisms of generation of induced pluripotent stem (iPS) cells from somatic cells via the introduction of transcription factors into adult somatic cells are considered. Particular attention is focused on the generation of iPS cells without genome modifications via the introduction of the mRNA of transcription factors or the use of small molecules. Furthermore, the strategy of direct reprogramming of somatic cells omitting the generation of iPS cells is considered. The data concerning the differences between ES and iPS cells and the problem of epigenetic memory are also discussed. In conclusion, the possibility of using iPS cells in regenerative medicine is considered. PMID:22708059

  14. Drug-induced status epilepticus.

    Science.gov (United States)

    Cock, Hannah R

    2015-08-01

    Drug-induced status epilepticus (SE) is a relatively uncommon phenomenon, probably accounting for less than 5% of all SE cases, although limitations in case ascertainment and establishing causation substantially weaken epidemiological estimates. Some antiepileptic drugs, particularly those with sodium channel or GABA(γ-aminobutyric acid)-ergic properties, frequently exacerbate seizures and may lead to SE if used inadvertently in generalized epilepsies or less frequently in other epilepsies. Tiagabine seems to have a particular propensity for triggering nonconvulsive SE sometimes in patients with no prior history of seizures. In therapeutic practice, SE is most commonly seen in association with antibiotics (cephalosporins, quinolones, and some others) and immunotherapies/chemotherapies, the latter often in the context of a reversible encephalopathy syndrome. Status epilepticus following accidental or intentional overdoses, particularly of antidepressants or other psychotropic medications, has also featured prominently in the literature: whilst there are sometimes fatal consequences, this is more commonly because of cardiorespiratory or metabolic complications than as a result of seizure activity. A high index of suspicion is required in identifying those at risk and in recognizing potential clues from the presentation, but even with a careful analysis of patient and drug factors, establishing causation can be difficult. In addition to eliminating the potential trigger, management should be as for SE in any other circumstances, with the exception that phenobarbitone is recommended as a second-line treatment for suspected toxicity-related SE where the risk of cardiovascular complications is higher anyways and may be exacerbated by phenytoin. There are also specific recommendations/antidotes in some situations. The outcome of drug-induced status epilepticus is mostly good when promptly identified and treated, though less so in the context of overdoses. This article is

  15. Induced gravity and gauge interactions revisited

    International Nuclear Information System (INIS)

    Broda, Boguslaw; Szanecki, Michal

    2009-01-01

    It has been shown that the primary, old-fashioned idea of Sakharov's induced gravity and gauge interactions, in the 'one-loop dominance' version, works astonishingly well yielding phenomenologically reasonable results. As a byproduct, the issue of the role of the UV cutoff in the context of the induced gravity has been reexamined (an idea of self-cutoff induced gravity). As an additional check, the black hole entropy has been used in the place of the action. Finally, it has been explicitly shown that the induced coupling constants of gauge interactions of the standard model assume qualitatively realistic values.

  16. Radiation-induced instability of human genome

    International Nuclear Information System (INIS)

    Ryabchenko, N.N.; Demina, Eh.A.

    2014-01-01

    A brief review is dedicated to the phenomenon of radiation-induced genomic instability where the increased level of genomic changes in the offspring of irradiated cells is characteristic. Particular attention is paid to the problems of genomic instability induced by the low-dose radiation, role of the bystander effect in formation of radiation-induced instability, and its relationship with individual radiosensitivity. We believe that in accordance with the paradigm of modern radiobiology the increased human individual radiosensitivity can be formed due to the genome instability onset and is a significant risk factor for radiation-induced cancer

  17. Quinine-induced tinnitus in rats.

    Science.gov (United States)

    Jastreboff, P J; Brennan, J F; Sasaki, C T

    1991-10-01

    Quinine ingestion reportedly induces tinnitus in humans. To expand our salicylate-based animal model of tinnitus, a series of conditioned suppression experiments was performed on 54 male-pigmented rats using quinine injections to induce tinnitus. Quinine induced changes in both the extent of suppression and recovery of licking, which followed a pattern that paralleled those produced after salicylate injections, and which may be interpreted as the result of tinnitus perception in animals. These changes depended on the dose and time schedule of quinine administration. Additionally, the calcium channel blocker, nimodipine, abolished the quinine-induced effect in a dose-dependent manner.

  18. IHH and FGF8 coregulate elongation of digit primordia.

    Science.gov (United States)

    Zhou, Jian; Meng, Junwei; Guo, Shengzhen; Gao, Bo; Ma, Gang; Zhu, Xuming; Hu, Jianxin; Xiao, Yue; Lin, Chuwen; Wang, Hongsheng; Ding, Lusheng; Feng, Guoyin; Guo, Xizhi; He, Lin

    2007-11-23

    In the developing limb bud, digit pattern arises from anterior-posterior (A-P) positional information which is provided by the concentration gradient of SHH. However, the mechanisms of translating early asymmetry into morphological form are still unclear. Here, we examined the ability of IHH and FGF8 signaling to regulate digital chondrogenesis, by implanting protein-loaded beads in the interdigital space singly and in combination. We found that IHH protein induced an elongated digit and that FGF8 protein blocked the terminal phalange formation. Molecular marker analysis showed that IHH expanded Sox9 expression in mesenchymal cells possibly through up-regulated FGF8 expression. Application of both IHH and FGF8 protein induced a large terminal phalange. These results suggest that both enhanced IHH and FGF8 signaling are required for the development of additional cartilage element in limbs. IHH and FGF8 maybe play different roles and act synergistically to promote chondrogenesis during digit primordia elongation.

  19. An evaluation of a hubless inducer and a full flow hydraulic turbine driven inducer boost pump

    Science.gov (United States)

    Lindley, B. K.; Martinson, A. R.

    1971-01-01

    The purpose of the study was to compare the performance of several configurations of hubless inducers with a hydrodynamically similar conventional inducer and to demonstrate the performance of a full flow hydraulic turbine driven inducer boost pump using these inducers. A boost pump of this type consists of an inducer connected to a hydraulic turbine with a high speed rotor located in between. All the flow passes through the inducer, rotor, and hydraulic turbine, then into the main pump. The rotor, which is attached to the main pump shaft, provides the input power to drive the hydraulic turbine which, in turn, drives the inducer. The inducer, rotating at a lower speed, develops the necessary head to prevent rotor cavitation. The rotor speed is consistent with present main engine liquid hydrogen pump designs and the overall boost pump head rise is sufficient to provide adequate main pump suction head. This system would have the potential for operating at lower liquid hydrogen tank pressures.

  20. The transition time induced narrow linewidth of the electromagnetically induced transparency in caesium vapour

    International Nuclear Information System (INIS)

    Li Luming; Peng Xiang; Liu Cheng; Guo Hong; Chen Xuzong

    2004-01-01

    We observed a narrow linewidth (∼60 kHz) in a Doppler-broadened system showing electromagnetically induced transparency in caesium atomic vapour. The transition time induced reduction of the linewidth is illustrated both theoretically and experimentally